29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
92 static const struct ssh_ttymode {
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "IUTF8", 42, TTY_OP_BOOL },
129 { "ISIG", 50, TTY_OP_BOOL },
130 { "ICANON", 51, TTY_OP_BOOL },
131 { "XCASE", 52, TTY_OP_BOOL },
132 { "ECHO", 53, TTY_OP_BOOL },
133 { "ECHOE", 54, TTY_OP_BOOL },
134 { "ECHOK", 55, TTY_OP_BOOL },
135 { "ECHONL", 56, TTY_OP_BOOL },
136 { "NOFLSH", 57, TTY_OP_BOOL },
137 { "TOSTOP", 58, TTY_OP_BOOL },
138 { "IEXTEN", 59, TTY_OP_BOOL },
139 { "ECHOCTL", 60, TTY_OP_BOOL },
140 { "ECHOKE", 61, TTY_OP_BOOL },
141 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
142 { "OPOST", 70, TTY_OP_BOOL },
143 { "OLCUC", 71, TTY_OP_BOOL },
144 { "ONLCR", 72, TTY_OP_BOOL },
145 { "OCRNL", 73, TTY_OP_BOOL },
146 { "ONOCR", 74, TTY_OP_BOOL },
147 { "ONLRET", 75, TTY_OP_BOOL },
148 { "CS7", 90, TTY_OP_BOOL },
149 { "CS8", 91, TTY_OP_BOOL },
150 { "PARENB", 92, TTY_OP_BOOL },
151 { "PARODD", 93, TTY_OP_BOOL }
154 /* Miscellaneous other tty-related constants. */
155 #define SSH_TTY_OP_END 0
156 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
157 #define SSH1_TTY_OP_ISPEED 192
158 #define SSH1_TTY_OP_OSPEED 193
159 #define SSH2_TTY_OP_ISPEED 128
160 #define SSH2_TTY_OP_OSPEED 129
162 /* Helper functions for parsing tty-related config. */
163 static unsigned int ssh_tty_parse_specchar(char *s)
168 ret = ctrlparse(s, &next);
169 if (!next) ret = s[0];
171 ret = 255; /* special value meaning "don't set" */
175 static unsigned int ssh_tty_parse_boolean(char *s)
177 if (stricmp(s, "yes") == 0 ||
178 stricmp(s, "on") == 0 ||
179 stricmp(s, "true") == 0 ||
180 stricmp(s, "+") == 0)
182 else if (stricmp(s, "no") == 0 ||
183 stricmp(s, "off") == 0 ||
184 stricmp(s, "false") == 0 ||
185 stricmp(s, "-") == 0)
186 return 0; /* false */
188 return (atoi(s) != 0);
191 #define translate(x) if (type == x) return #x
192 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
193 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
194 static const char *ssh1_pkt_type(int type)
196 translate(SSH1_MSG_DISCONNECT);
197 translate(SSH1_SMSG_PUBLIC_KEY);
198 translate(SSH1_CMSG_SESSION_KEY);
199 translate(SSH1_CMSG_USER);
200 translate(SSH1_CMSG_AUTH_RSA);
201 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
202 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
203 translate(SSH1_CMSG_AUTH_PASSWORD);
204 translate(SSH1_CMSG_REQUEST_PTY);
205 translate(SSH1_CMSG_WINDOW_SIZE);
206 translate(SSH1_CMSG_EXEC_SHELL);
207 translate(SSH1_CMSG_EXEC_CMD);
208 translate(SSH1_SMSG_SUCCESS);
209 translate(SSH1_SMSG_FAILURE);
210 translate(SSH1_CMSG_STDIN_DATA);
211 translate(SSH1_SMSG_STDOUT_DATA);
212 translate(SSH1_SMSG_STDERR_DATA);
213 translate(SSH1_CMSG_EOF);
214 translate(SSH1_SMSG_EXIT_STATUS);
215 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
216 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
217 translate(SSH1_MSG_CHANNEL_DATA);
218 translate(SSH1_MSG_CHANNEL_CLOSE);
219 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
220 translate(SSH1_SMSG_X11_OPEN);
221 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
222 translate(SSH1_MSG_PORT_OPEN);
223 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
224 translate(SSH1_SMSG_AGENT_OPEN);
225 translate(SSH1_MSG_IGNORE);
226 translate(SSH1_CMSG_EXIT_CONFIRMATION);
227 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
228 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
229 translate(SSH1_MSG_DEBUG);
230 translate(SSH1_CMSG_REQUEST_COMPRESSION);
231 translate(SSH1_CMSG_AUTH_TIS);
232 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
234 translate(SSH1_CMSG_AUTH_CCARD);
235 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
236 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
239 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
247 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
248 translate(SSH2_MSG_DISCONNECT);
249 translate(SSH2_MSG_IGNORE);
250 translate(SSH2_MSG_UNIMPLEMENTED);
251 translate(SSH2_MSG_DEBUG);
252 translate(SSH2_MSG_SERVICE_REQUEST);
253 translate(SSH2_MSG_SERVICE_ACCEPT);
254 translate(SSH2_MSG_KEXINIT);
255 translate(SSH2_MSG_NEWKEYS);
256 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
263 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
266 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
267 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
268 translate(SSH2_MSG_USERAUTH_REQUEST);
269 translate(SSH2_MSG_USERAUTH_FAILURE);
270 translate(SSH2_MSG_USERAUTH_SUCCESS);
271 translate(SSH2_MSG_USERAUTH_BANNER);
272 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
273 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
274 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
275 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
276 translate(SSH2_MSG_GLOBAL_REQUEST);
277 translate(SSH2_MSG_REQUEST_SUCCESS);
278 translate(SSH2_MSG_REQUEST_FAILURE);
279 translate(SSH2_MSG_CHANNEL_OPEN);
280 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
281 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
282 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
283 translate(SSH2_MSG_CHANNEL_DATA);
284 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
285 translate(SSH2_MSG_CHANNEL_EOF);
286 translate(SSH2_MSG_CHANNEL_CLOSE);
287 translate(SSH2_MSG_CHANNEL_REQUEST);
288 translate(SSH2_MSG_CHANNEL_SUCCESS);
289 translate(SSH2_MSG_CHANNEL_FAILURE);
295 /* Enumeration values for fields in SSH-1 packets */
297 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
301 * Coroutine mechanics for the sillier bits of the code. If these
302 * macros look impenetrable to you, you might find it helpful to
305 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
307 * which explains the theory behind these macros.
309 * In particular, if you are getting `case expression not constant'
310 * errors when building with MS Visual Studio, this is because MS's
311 * Edit and Continue debugging feature causes their compiler to
312 * violate ANSI C. To disable Edit and Continue debugging:
314 * - right-click ssh.c in the FileView
316 * - select the C/C++ tab and the General category
317 * - under `Debug info:', select anything _other_ than `Program
318 * Database for Edit and Continue'.
320 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
321 #define crBeginState crBegin(s->crLine)
322 #define crStateP(t, v) \
324 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
326 #define crState(t) crStateP(t, ssh->t)
327 #define crFinish(z) } *crLine = 0; return (z); }
328 #define crFinishV } *crLine = 0; return; }
329 #define crFinishFree(z) } sfree(s); return (z); }
330 #define crFinishFreeV } sfree(s); return; }
331 #define crReturn(z) \
333 *crLine =__LINE__; return (z); case __LINE__:;\
337 *crLine=__LINE__; return; case __LINE__:;\
339 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
340 #define crStopV do{ *crLine = 0; return; }while(0)
341 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
342 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
346 static struct Packet *ssh1_pkt_init(int pkt_type);
347 static struct Packet *ssh2_pkt_init(int pkt_type);
348 static void ssh_pkt_ensure(struct Packet *, int length);
349 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
350 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
351 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
352 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
353 static void ssh_pkt_addstring_start(struct Packet *);
354 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
355 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
356 static void ssh_pkt_addstring(struct Packet *, const char *data);
357 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
358 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
359 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
360 static int ssh2_pkt_construct(Ssh, struct Packet *);
361 static void ssh2_pkt_send(Ssh, struct Packet *);
362 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
363 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
366 struct Packet *pktin);
367 static void ssh_channel_init(struct ssh_channel *c);
368 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin);
369 static void ssh_channel_got_eof(struct ssh_channel *c);
370 static void ssh2_channel_check_close(struct ssh_channel *c);
371 static void ssh_channel_close_local(struct ssh_channel *c, char const *reason);
372 static void ssh_channel_destroy(struct ssh_channel *c);
373 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize);
374 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
377 * Buffer management constants. There are several of these for
378 * various different purposes:
380 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
381 * on a local data stream before we throttle the whole SSH
382 * connection (in SSH-1 only). Throttling the whole connection is
383 * pretty drastic so we set this high in the hope it won't
386 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
387 * on the SSH connection itself before we defensively throttle
388 * _all_ local data streams. This is pretty drastic too (though
389 * thankfully unlikely in SSH-2 since the window mechanism should
390 * ensure that the server never has any need to throttle its end
391 * of the connection), so we set this high as well.
393 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
396 * - OUR_V2_BIGWIN is the window size we advertise for the only
397 * channel in a simple connection. It must be <= INT_MAX.
399 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
400 * to the remote side. This actually has nothing to do with the
401 * size of the _packet_, but is instead a limit on the amount
402 * of data we're willing to receive in a single SSH2 channel
405 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
406 * _packet_ we're prepared to cope with. It must be a multiple
407 * of the cipher block size, and must be at least 35000.
410 #define SSH1_BUFFER_LIMIT 32768
411 #define SSH_MAX_BACKLOG 32768
412 #define OUR_V2_WINSIZE 16384
413 #define OUR_V2_BIGWIN 0x7fffffff
414 #define OUR_V2_MAXPKT 0x4000UL
415 #define OUR_V2_PACKETLIMIT 0x9000UL
417 struct ssh_signkey_with_user_pref_id {
418 const struct ssh_signkey *alg;
421 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
422 { &ssh_ecdsa_ed25519, HK_ED25519 },
423 { &ssh_ecdsa_nistp256, HK_ECDSA },
424 { &ssh_ecdsa_nistp384, HK_ECDSA },
425 { &ssh_ecdsa_nistp521, HK_ECDSA },
426 { &ssh_dss, HK_DSA },
427 { &ssh_rsa, HK_RSA },
430 const static struct ssh_mac *const macs[] = {
431 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
433 const static struct ssh_mac *const buggymacs[] = {
434 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
437 static void *ssh_comp_none_init(void)
441 static void ssh_comp_none_cleanup(void *handle)
444 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
445 unsigned char **outblock, int *outlen)
449 static int ssh_comp_none_disable(void *handle)
453 const static struct ssh_compress ssh_comp_none = {
455 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
456 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
457 ssh_comp_none_disable, NULL
459 extern const struct ssh_compress ssh_zlib;
460 const static struct ssh_compress *const compressions[] = {
461 &ssh_zlib, &ssh_comp_none
464 enum { /* channel types */
470 * CHAN_SHARING indicates a channel which is tracked here on
471 * behalf of a connection-sharing downstream. We do almost nothing
472 * with these channels ourselves: all messages relating to them
473 * get thrown straight to sshshare.c and passed on almost
474 * unmodified to downstream.
478 * CHAN_ZOMBIE is used to indicate a channel for which we've
479 * already destroyed the local data source: for instance, if a
480 * forwarded port experiences a socket error on the local side, we
481 * immediately destroy its local socket and turn the SSH channel
487 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
488 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
489 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
492 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
495 struct outstanding_channel_request {
496 cchandler_fn_t handler;
498 struct outstanding_channel_request *next;
502 * 2-3-4 tree storing channels.
505 Ssh ssh; /* pointer back to main context */
506 unsigned remoteid, localid;
508 /* True if we opened this channel but server hasn't confirmed. */
511 * In SSH-1, this value contains four bits:
513 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
514 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
515 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
516 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
518 * A channel is completely finished with when all four bits are set.
520 * In SSH-2, the four bits mean:
522 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
523 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
524 * 4 We have received SSH2_MSG_CHANNEL_EOF.
525 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
527 * A channel is completely finished with when we have both sent
528 * and received CLOSE.
530 * The symbolic constants below use the SSH-2 terminology, which
531 * is a bit confusing in SSH-1, but we have to use _something_.
533 #define CLOSES_SENT_EOF 1
534 #define CLOSES_SENT_CLOSE 2
535 #define CLOSES_RCVD_EOF 4
536 #define CLOSES_RCVD_CLOSE 8
540 * This flag indicates that an EOF is pending on the outgoing side
541 * of the channel: that is, wherever we're getting the data for
542 * this channel has sent us some data followed by EOF. We can't
543 * actually send the EOF until we've finished sending the data, so
544 * we set this flag instead to remind us to do so once our buffer
550 * True if this channel is causing the underlying connection to be
555 struct ssh2_data_channel {
557 unsigned remwindow, remmaxpkt;
558 /* locwindow is signed so we can cope with excess data. */
559 int locwindow, locmaxwin;
561 * remlocwin is the amount of local window that we think
562 * the remote end had available to it after it sent the
563 * last data packet or window adjust ack.
567 * These store the list of channel requests that haven't
570 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
571 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
575 struct ssh_agent_channel {
577 agent_pending_query *pending;
579 struct ssh_x11_channel {
580 struct X11Connection *xconn;
583 struct ssh_pfd_channel {
584 struct PortForwarding *pf;
586 struct ssh_sharing_channel {
593 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
594 * use this structure in different ways, reflecting SSH-2's
595 * altogether saner approach to port forwarding.
597 * In SSH-1, you arrange a remote forwarding by sending the server
598 * the remote port number, and the local destination host:port.
599 * When a connection comes in, the server sends you back that
600 * host:port pair, and you connect to it. This is a ready-made
601 * security hole if you're not on the ball: a malicious server
602 * could send you back _any_ host:port pair, so if you trustingly
603 * connect to the address it gives you then you've just opened the
604 * entire inside of your corporate network just by connecting
605 * through it to a dodgy SSH server. Hence, we must store a list of
606 * host:port pairs we _are_ trying to forward to, and reject a
607 * connection request from the server if it's not in the list.
609 * In SSH-2, each side of the connection minds its own business and
610 * doesn't send unnecessary information to the other. You arrange a
611 * remote forwarding by sending the server just the remote port
612 * number. When a connection comes in, the server tells you which
613 * of its ports was connected to; and _you_ have to remember what
614 * local host:port pair went with that port number.
616 * Hence, in SSH-1 this structure is indexed by destination
617 * host:port pair, whereas in SSH-2 it is indexed by source port.
619 struct ssh_portfwd; /* forward declaration */
621 struct ssh_rportfwd {
622 unsigned sport, dport;
626 struct ssh_portfwd *pfrec;
629 static void free_rportfwd(struct ssh_rportfwd *pf)
632 sfree(pf->sportdesc);
640 * Separately to the rportfwd tree (which is for looking up port
641 * open requests from the server), a tree of _these_ structures is
642 * used to keep track of all the currently open port forwardings,
643 * so that we can reconfigure in mid-session if the user requests
647 enum { DESTROY, KEEP, CREATE } status;
649 unsigned sport, dport;
652 struct ssh_rportfwd *remote;
654 struct PortListener *local;
656 #define free_portfwd(pf) ( \
657 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
658 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
661 long length; /* length of packet: see below */
662 long forcepad; /* SSH-2: force padding to at least this length */
663 int type; /* only used for incoming packets */
664 unsigned long sequence; /* SSH-2 incoming sequence number */
665 unsigned char *data; /* allocated storage */
666 unsigned char *body; /* offset of payload within `data' */
667 long savedpos; /* dual-purpose saved packet position: see below */
668 long maxlen; /* amount of storage allocated for `data' */
669 long encrypted_len; /* for SSH-2 total-size counting */
672 * A note on the 'length' and 'savedpos' fields above.
674 * Incoming packets are set up so that pkt->length is measured
675 * relative to pkt->body, which itself points to a few bytes after
676 * pkt->data (skipping some uninteresting header fields including
677 * the packet type code). The ssh_pkt_get* functions all expect
678 * this setup, and they also use pkt->savedpos to indicate how far
679 * through the packet being decoded they've got - and that, too,
680 * is an offset from pkt->body rather than pkt->data.
682 * During construction of an outgoing packet, however, pkt->length
683 * is measured relative to the base pointer pkt->data, and
684 * pkt->body is not really used for anything until the packet is
685 * ready for sending. In this mode, pkt->savedpos is reused as a
686 * temporary variable by the addstring functions, which write out
687 * a string length field and then keep going back and updating it
688 * as more data is appended to the subsequent string data field;
689 * pkt->savedpos stores the offset (again relative to pkt->data)
690 * of the start of the string data field.
693 /* Extra metadata used in SSH packet logging mode, allowing us to
694 * log in the packet header line that the packet came from a
695 * connection-sharing downstream and what if anything unusual was
696 * done to it. The additional_log_text field is expected to be a
697 * static string - it will not be freed. */
698 unsigned downstream_id;
699 const char *additional_log_text;
702 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
703 struct Packet *pktin);
704 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
705 struct Packet *pktin);
706 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
707 struct Packet *pktin);
708 static void ssh1_protocol_setup(Ssh ssh);
709 static void ssh2_protocol_setup(Ssh ssh);
710 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
711 static void ssh_size(void *handle, int width, int height);
712 static void ssh_special(void *handle, Telnet_Special);
713 static int ssh2_try_send(struct ssh_channel *c);
714 static int ssh_send_channel_data(struct ssh_channel *c,
715 const char *buf, int len);
716 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
717 static void ssh2_set_window(struct ssh_channel *c, int newwin);
718 static int ssh_sendbuffer(void *handle);
719 static int ssh_do_close(Ssh ssh, int notify_exit);
720 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
721 static int ssh2_pkt_getbool(struct Packet *pkt);
722 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
723 static void ssh2_timer(void *ctx, unsigned long now);
724 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
725 struct Packet *pktin);
726 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
728 struct rdpkt1_state_tag {
729 long len, pad, biglen, to_read;
730 unsigned long realcrc, gotcrc;
734 struct Packet *pktin;
737 struct rdpkt2_state_tag {
738 long len, pad, payload, packetlen, maclen;
741 unsigned long incoming_sequence;
742 struct Packet *pktin;
745 struct rdpkt2_bare_state_tag {
749 unsigned long incoming_sequence;
750 struct Packet *pktin;
753 struct queued_handler;
754 struct queued_handler {
756 chandler_fn_t handler;
758 struct queued_handler *next;
762 const struct plug_function_table *fn;
763 /* the above field _must_ be first in the structure */
773 unsigned char session_key[32];
775 int v1_remote_protoflags;
776 int v1_local_protoflags;
777 int agentfwd_enabled;
780 const struct ssh_cipher *cipher;
783 const struct ssh2_cipher *cscipher, *sccipher;
784 void *cs_cipher_ctx, *sc_cipher_ctx;
785 const struct ssh_mac *csmac, *scmac;
786 int csmac_etm, scmac_etm;
787 void *cs_mac_ctx, *sc_mac_ctx;
788 const struct ssh_compress *cscomp, *sccomp;
789 void *cs_comp_ctx, *sc_comp_ctx;
790 const struct ssh_kex *kex;
791 const struct ssh_signkey *hostkey;
792 char *hostkey_str; /* string representation, for easy checking in rekeys */
793 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
794 int v2_session_id_len;
798 int attempting_connshare;
804 int echoing, editing;
809 int ospeed, ispeed; /* temporaries */
810 int term_width, term_height;
812 tree234 *channels; /* indexed by local id */
813 struct ssh_channel *mainchan; /* primary session channel */
814 int ncmode; /* is primary channel direct-tcpip? */
819 tree234 *rportfwds, *portfwds;
823 SSH_STATE_BEFORE_SIZE,
829 int size_needed, eof_needed;
830 int sent_console_eof;
831 int got_pty; /* affects EOF behaviour on main channel */
833 struct Packet **queue;
834 int queuelen, queuesize;
836 unsigned char *deferred_send_data;
837 int deferred_len, deferred_size;
840 * Gross hack: pscp will try to start SFTP but fall back to
841 * scp1 if that fails. This variable is the means by which
842 * scp.c can reach into the SSH code and find out which one it
847 bufchain banner; /* accumulates banners during do_ssh2_authconn */
852 struct X11Display *x11disp;
853 struct X11FakeAuth *x11auth;
854 tree234 *x11authtree;
857 int conn_throttle_count;
860 int v1_stdout_throttling;
861 unsigned long v2_outgoing_sequence;
863 int ssh1_rdpkt_crstate;
864 int ssh2_rdpkt_crstate;
865 int ssh2_bare_rdpkt_crstate;
866 int ssh_gotdata_crstate;
867 int do_ssh1_connection_crstate;
869 void *do_ssh_init_state;
870 void *do_ssh1_login_state;
871 void *do_ssh2_transport_state;
872 void *do_ssh2_authconn_state;
873 void *do_ssh_connection_init_state;
875 struct rdpkt1_state_tag rdpkt1_state;
876 struct rdpkt2_state_tag rdpkt2_state;
877 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
879 /* SSH-1 and SSH-2 use this for different things, but both use it */
880 int protocol_initial_phase_done;
882 void (*protocol) (Ssh ssh, const void *vin, int inlen,
884 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
886 int (*do_ssh_init)(Ssh ssh, unsigned char c);
889 * We maintain our own copy of a Conf structure here. That way,
890 * when we're passed a new one for reconfiguration, we can check
891 * the differences and potentially reconfigure port forwardings
892 * etc in mid-session.
897 * Values cached out of conf so as to avoid the tree234 lookup
898 * cost every time they're used.
903 * Dynamically allocated username string created during SSH
904 * login. Stored in here rather than in the coroutine state so
905 * that it'll be reliably freed if we shut down the SSH session
906 * at some unexpected moment.
911 * Used to transfer data back from async callbacks.
913 void *agent_response;
914 int agent_response_len;
918 * The SSH connection can be set as `frozen', meaning we are
919 * not currently accepting incoming data from the network. This
920 * is slightly more serious than setting the _socket_ as
921 * frozen, because we may already have had data passed to us
922 * from the network which we need to delay processing until
923 * after the freeze is lifted, so we also need a bufchain to
927 bufchain queued_incoming_data;
930 * Dispatch table for packet types that we may have to deal
933 handler_fn_t packet_dispatch[256];
936 * Queues of one-off handler functions for success/failure
937 * indications from a request.
939 struct queued_handler *qhead, *qtail;
940 handler_fn_t q_saved_handler1, q_saved_handler2;
943 * This module deals with sending keepalives.
948 * Track incoming and outgoing data sizes and time, for
951 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
952 unsigned long max_data_size;
954 unsigned long next_rekey, last_rekey;
955 const char *deferred_rekey_reason;
958 * Fully qualified host name, which we need if doing GSSAPI.
964 * GSSAPI libraries for this session.
966 struct ssh_gss_liblist *gsslibs;
970 * The last list returned from get_specials.
972 struct telnet_special *specials;
975 * List of host key algorithms for which we _don't_ have a stored
976 * host key. These are indices into the main hostkey_algs[] array
978 int uncert_hostkeys[lenof(hostkey_algs)];
979 int n_uncert_hostkeys;
982 * Flag indicating that the current rekey is intended to finish
983 * with a newly cross-certified host key.
985 int cross_certifying;
988 * Any asynchronous query to our SSH agent that we might have in
989 * flight from the main authentication loop. (Queries from
990 * agent-forwarding channels live in their channel structure.)
992 agent_pending_query *auth_agent_query;
995 static const char *ssh_pkt_type(Ssh ssh, int type)
997 if (ssh->version == 1)
998 return ssh1_pkt_type(type);
1000 return ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, type);
1003 #define logevent(s) logevent(ssh->frontend, s)
1005 /* logevent, only printf-formatted. */
1006 static void logeventf(Ssh ssh, const char *fmt, ...)
1012 buf = dupvprintf(fmt, ap);
1018 static void bomb_out(Ssh ssh, char *text)
1020 ssh_do_close(ssh, FALSE);
1022 connection_fatal(ssh->frontend, "%s", text);
1026 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1028 /* Helper function for common bits of parsing ttymodes. */
1029 static void parse_ttymodes(Ssh ssh,
1030 void (*do_mode)(void *data,
1031 const struct ssh_ttymode *mode,
1036 const struct ssh_ttymode *mode;
1038 char default_val[2];
1040 strcpy(default_val, "A");
1042 for (i = 0; i < lenof(ssh_ttymodes); i++) {
1043 mode = ssh_ttymodes + i;
1044 val = conf_get_str_str_opt(ssh->conf, CONF_ttymodes, mode->mode);
1049 * val[0] is either 'V', indicating that an explicit value
1050 * follows it, or 'A' indicating that we should pass the
1051 * value through from the local environment via get_ttymode.
1053 if (val[0] == 'A') {
1054 val = get_ttymode(ssh->frontend, mode->mode);
1056 do_mode(data, mode, val);
1060 do_mode(data, mode, val + 1); /* skip the 'V' */
1064 static int ssh_channelcmp(void *av, void *bv)
1066 struct ssh_channel *a = (struct ssh_channel *) av;
1067 struct ssh_channel *b = (struct ssh_channel *) bv;
1068 if (a->localid < b->localid)
1070 if (a->localid > b->localid)
1074 static int ssh_channelfind(void *av, void *bv)
1076 unsigned *a = (unsigned *) av;
1077 struct ssh_channel *b = (struct ssh_channel *) bv;
1078 if (*a < b->localid)
1080 if (*a > b->localid)
1085 static int ssh_rportcmp_ssh1(void *av, void *bv)
1087 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1088 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1090 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1091 return i < 0 ? -1 : +1;
1092 if (a->dport > b->dport)
1094 if (a->dport < b->dport)
1099 static int ssh_rportcmp_ssh2(void *av, void *bv)
1101 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1102 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1104 if ( (i = strcmp(a->shost, b->shost)) != 0)
1105 return i < 0 ? -1 : +1;
1106 if (a->sport > b->sport)
1108 if (a->sport < b->sport)
1114 * Special form of strcmp which can cope with NULL inputs. NULL is
1115 * defined to sort before even the empty string.
1117 static int nullstrcmp(const char *a, const char *b)
1119 if (a == NULL && b == NULL)
1125 return strcmp(a, b);
1128 static int ssh_portcmp(void *av, void *bv)
1130 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1131 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1133 if (a->type > b->type)
1135 if (a->type < b->type)
1137 if (a->addressfamily > b->addressfamily)
1139 if (a->addressfamily < b->addressfamily)
1141 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1142 return i < 0 ? -1 : +1;
1143 if (a->sport > b->sport)
1145 if (a->sport < b->sport)
1147 if (a->type != 'D') {
1148 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1149 return i < 0 ? -1 : +1;
1150 if (a->dport > b->dport)
1152 if (a->dport < b->dport)
1158 static int alloc_channel_id(Ssh ssh)
1160 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1161 unsigned low, high, mid;
1163 struct ssh_channel *c;
1166 * First-fit allocation of channel numbers: always pick the
1167 * lowest unused one. To do this, binary-search using the
1168 * counted B-tree to find the largest channel ID which is in a
1169 * contiguous sequence from the beginning. (Precisely
1170 * everything in that sequence must have ID equal to its tree
1171 * index plus CHANNEL_NUMBER_OFFSET.)
1173 tsize = count234(ssh->channels);
1177 while (high - low > 1) {
1178 mid = (high + low) / 2;
1179 c = index234(ssh->channels, mid);
1180 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1181 low = mid; /* this one is fine */
1183 high = mid; /* this one is past it */
1186 * Now low points to either -1, or the tree index of the
1187 * largest ID in the initial sequence.
1190 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1191 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1193 return low + 1 + CHANNEL_NUMBER_OFFSET;
1196 static void c_write_stderr(int trusted, const char *buf, int len)
1199 for (i = 0; i < len; i++)
1200 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1201 fputc(buf[i], stderr);
1204 static void c_write(Ssh ssh, const char *buf, int len)
1206 if (flags & FLAG_STDERR)
1207 c_write_stderr(1, buf, len);
1209 from_backend(ssh->frontend, 1, buf, len);
1212 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1214 if (flags & FLAG_STDERR)
1215 c_write_stderr(0, buf, len);
1217 from_backend_untrusted(ssh->frontend, buf, len);
1220 static void c_write_str(Ssh ssh, const char *buf)
1222 c_write(ssh, buf, strlen(buf));
1225 static void ssh_free_packet(struct Packet *pkt)
1230 static struct Packet *ssh_new_packet(void)
1232 struct Packet *pkt = snew(struct Packet);
1234 pkt->body = pkt->data = NULL;
1240 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1243 struct logblank_t blanks[4];
1249 if (ssh->logomitdata &&
1250 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1251 pkt->type == SSH1_SMSG_STDERR_DATA ||
1252 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1253 /* "Session data" packets - omit the data string. */
1254 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1255 ssh_pkt_getuint32(pkt); /* skip channel id */
1256 blanks[nblanks].offset = pkt->savedpos + 4;
1257 blanks[nblanks].type = PKTLOG_OMIT;
1258 ssh_pkt_getstring(pkt, &str, &slen);
1260 blanks[nblanks].len = slen;
1264 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1265 ssh1_pkt_type(pkt->type),
1266 pkt->body, pkt->length, nblanks, blanks, NULL,
1270 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1273 struct logblank_t blanks[4];
1278 * For outgoing packets, pkt->length represents the length of the
1279 * whole packet starting at pkt->data (including some header), and
1280 * pkt->body refers to the point within that where the log-worthy
1281 * payload begins. However, incoming packets expect pkt->length to
1282 * represent only the payload length (that is, it's measured from
1283 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1284 * packet to conform to the incoming-packet semantics, so that we
1285 * can analyse it with the ssh_pkt_get functions.
1287 pkt->length -= (pkt->body - pkt->data);
1290 if (ssh->logomitdata &&
1291 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1292 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1293 /* "Session data" packets - omit the data string. */
1294 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1295 ssh_pkt_getuint32(pkt); /* skip channel id */
1296 blanks[nblanks].offset = pkt->savedpos + 4;
1297 blanks[nblanks].type = PKTLOG_OMIT;
1298 ssh_pkt_getstring(pkt, &str, &slen);
1300 blanks[nblanks].len = slen;
1305 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1306 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1307 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1308 conf_get_int(ssh->conf, CONF_logomitpass)) {
1309 /* If this is a password or similar packet, blank the password(s). */
1310 blanks[nblanks].offset = 0;
1311 blanks[nblanks].len = pkt->length;
1312 blanks[nblanks].type = PKTLOG_BLANK;
1314 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1315 conf_get_int(ssh->conf, CONF_logomitpass)) {
1317 * If this is an X forwarding request packet, blank the fake
1320 * Note that while we blank the X authentication data here, we
1321 * don't take any special action to blank the start of an X11
1322 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1323 * an X connection without having session blanking enabled is
1324 * likely to leak your cookie into the log.
1327 ssh_pkt_getstring(pkt, &str, &slen);
1328 blanks[nblanks].offset = pkt->savedpos;
1329 blanks[nblanks].type = PKTLOG_BLANK;
1330 ssh_pkt_getstring(pkt, &str, &slen);
1332 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1337 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1338 ssh1_pkt_type(pkt->data[12]),
1339 pkt->body, pkt->length,
1340 nblanks, blanks, NULL, 0, NULL);
1343 * Undo the above adjustment of pkt->length, to put the packet
1344 * back in the state we found it.
1346 pkt->length += (pkt->body - pkt->data);
1350 * Collect incoming data in the incoming packet buffer.
1351 * Decipher and verify the packet when it is completely read.
1352 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1353 * Update the *data and *datalen variables.
1354 * Return a Packet structure when a packet is completed.
1356 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1359 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1361 crBegin(ssh->ssh1_rdpkt_crstate);
1363 st->pktin = ssh_new_packet();
1365 st->pktin->type = 0;
1366 st->pktin->length = 0;
1368 for (st->i = st->len = 0; st->i < 4; st->i++) {
1369 while ((*datalen) == 0)
1371 st->len = (st->len << 8) + **data;
1372 (*data)++, (*datalen)--;
1375 st->pad = 8 - (st->len % 8);
1376 st->biglen = st->len + st->pad;
1377 st->pktin->length = st->len - 5;
1379 if (st->biglen < 0) {
1380 bombout(("Extremely large packet length from server suggests"
1381 " data stream corruption"));
1382 ssh_free_packet(st->pktin);
1386 st->pktin->maxlen = st->biglen;
1387 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1389 st->to_read = st->biglen;
1390 st->p = st->pktin->data;
1391 while (st->to_read > 0) {
1392 st->chunk = st->to_read;
1393 while ((*datalen) == 0)
1395 if (st->chunk > (*datalen))
1396 st->chunk = (*datalen);
1397 memcpy(st->p, *data, st->chunk);
1399 *datalen -= st->chunk;
1401 st->to_read -= st->chunk;
1404 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1405 st->biglen, NULL)) {
1406 bombout(("Network attack (CRC compensation) detected!"));
1407 ssh_free_packet(st->pktin);
1412 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1414 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1415 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1416 if (st->gotcrc != st->realcrc) {
1417 bombout(("Incorrect CRC received on packet"));
1418 ssh_free_packet(st->pktin);
1422 st->pktin->body = st->pktin->data + st->pad + 1;
1424 if (ssh->v1_compressing) {
1425 unsigned char *decompblk;
1427 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1428 st->pktin->body - 1, st->pktin->length + 1,
1429 &decompblk, &decomplen)) {
1430 bombout(("Zlib decompression encountered invalid data"));
1431 ssh_free_packet(st->pktin);
1435 if (st->pktin->maxlen < st->pad + decomplen) {
1436 st->pktin->maxlen = st->pad + decomplen;
1437 st->pktin->data = sresize(st->pktin->data,
1438 st->pktin->maxlen + APIEXTRA,
1440 st->pktin->body = st->pktin->data + st->pad + 1;
1443 memcpy(st->pktin->body - 1, decompblk, decomplen);
1445 st->pktin->length = decomplen - 1;
1448 st->pktin->type = st->pktin->body[-1];
1451 * Now pktin->body and pktin->length identify the semantic content
1452 * of the packet, excluding the initial type byte.
1456 ssh1_log_incoming_packet(ssh, st->pktin);
1458 st->pktin->savedpos = 0;
1460 crFinish(st->pktin);
1463 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1466 struct logblank_t blanks[4];
1472 if (ssh->logomitdata &&
1473 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1474 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1475 /* "Session data" packets - omit the data string. */
1476 ssh_pkt_getuint32(pkt); /* skip channel id */
1477 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1478 ssh_pkt_getuint32(pkt); /* skip extended data type */
1479 blanks[nblanks].offset = pkt->savedpos + 4;
1480 blanks[nblanks].type = PKTLOG_OMIT;
1481 ssh_pkt_getstring(pkt, &str, &slen);
1483 blanks[nblanks].len = slen;
1488 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1489 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1490 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1494 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1497 struct logblank_t blanks[4];
1502 * For outgoing packets, pkt->length represents the length of the
1503 * whole packet starting at pkt->data (including some header), and
1504 * pkt->body refers to the point within that where the log-worthy
1505 * payload begins. However, incoming packets expect pkt->length to
1506 * represent only the payload length (that is, it's measured from
1507 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1508 * packet to conform to the incoming-packet semantics, so that we
1509 * can analyse it with the ssh_pkt_get functions.
1511 pkt->length -= (pkt->body - pkt->data);
1514 if (ssh->logomitdata &&
1515 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1516 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1517 /* "Session data" packets - omit the data string. */
1518 ssh_pkt_getuint32(pkt); /* skip channel id */
1519 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1520 ssh_pkt_getuint32(pkt); /* skip extended data type */
1521 blanks[nblanks].offset = pkt->savedpos + 4;
1522 blanks[nblanks].type = PKTLOG_OMIT;
1523 ssh_pkt_getstring(pkt, &str, &slen);
1525 blanks[nblanks].len = slen;
1530 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1531 conf_get_int(ssh->conf, CONF_logomitpass)) {
1532 /* If this is a password packet, blank the password(s). */
1534 ssh_pkt_getstring(pkt, &str, &slen);
1535 ssh_pkt_getstring(pkt, &str, &slen);
1536 ssh_pkt_getstring(pkt, &str, &slen);
1537 if (slen == 8 && !memcmp(str, "password", 8)) {
1538 ssh2_pkt_getbool(pkt);
1539 /* Blank the password field. */
1540 blanks[nblanks].offset = pkt->savedpos;
1541 blanks[nblanks].type = PKTLOG_BLANK;
1542 ssh_pkt_getstring(pkt, &str, &slen);
1544 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1546 /* If there's another password field beyond it (change of
1547 * password), blank that too. */
1548 ssh_pkt_getstring(pkt, &str, &slen);
1550 blanks[nblanks-1].len =
1551 pkt->savedpos - blanks[nblanks].offset;
1554 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1555 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1556 conf_get_int(ssh->conf, CONF_logomitpass)) {
1557 /* If this is a keyboard-interactive response packet, blank
1560 ssh_pkt_getuint32(pkt);
1561 blanks[nblanks].offset = pkt->savedpos;
1562 blanks[nblanks].type = PKTLOG_BLANK;
1564 ssh_pkt_getstring(pkt, &str, &slen);
1568 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1570 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1571 conf_get_int(ssh->conf, CONF_logomitpass)) {
1573 * If this is an X forwarding request packet, blank the fake
1576 * Note that while we blank the X authentication data here, we
1577 * don't take any special action to blank the start of an X11
1578 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1579 * an X connection without having session blanking enabled is
1580 * likely to leak your cookie into the log.
1583 ssh_pkt_getuint32(pkt);
1584 ssh_pkt_getstring(pkt, &str, &slen);
1585 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1586 ssh2_pkt_getbool(pkt);
1587 ssh2_pkt_getbool(pkt);
1588 ssh_pkt_getstring(pkt, &str, &slen);
1589 blanks[nblanks].offset = pkt->savedpos;
1590 blanks[nblanks].type = PKTLOG_BLANK;
1591 ssh_pkt_getstring(pkt, &str, &slen);
1593 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1599 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1600 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1601 pkt->body, pkt->length, nblanks, blanks,
1602 &ssh->v2_outgoing_sequence,
1603 pkt->downstream_id, pkt->additional_log_text);
1606 * Undo the above adjustment of pkt->length, to put the packet
1607 * back in the state we found it.
1609 pkt->length += (pkt->body - pkt->data);
1612 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1615 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1617 crBegin(ssh->ssh2_rdpkt_crstate);
1619 st->pktin = ssh_new_packet();
1621 st->pktin->type = 0;
1622 st->pktin->length = 0;
1624 st->cipherblk = ssh->sccipher->blksize;
1627 if (st->cipherblk < 8)
1629 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1631 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1632 ssh->scmac && !ssh->scmac_etm) {
1634 * When dealing with a CBC-mode cipher, we want to avoid the
1635 * possibility of an attacker's tweaking the ciphertext stream
1636 * so as to cause us to feed the same block to the block
1637 * cipher more than once and thus leak information
1638 * (VU#958563). The way we do this is not to take any
1639 * decisions on the basis of anything we've decrypted until
1640 * we've verified it with a MAC. That includes the packet
1641 * length, so we just read data and check the MAC repeatedly,
1642 * and when the MAC passes, see if the length we've got is
1645 * This defence is unnecessary in OpenSSH ETM mode, because
1646 * the whole point of ETM mode is that the attacker can't
1647 * tweak the ciphertext stream at all without the MAC
1648 * detecting it before we decrypt anything.
1651 /* May as well allocate the whole lot now. */
1652 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1655 /* Read an amount corresponding to the MAC. */
1656 for (st->i = 0; st->i < st->maclen; st->i++) {
1657 while ((*datalen) == 0)
1659 st->pktin->data[st->i] = *(*data)++;
1665 unsigned char seq[4];
1666 ssh->scmac->start(ssh->sc_mac_ctx);
1667 PUT_32BIT(seq, st->incoming_sequence);
1668 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1671 for (;;) { /* Once around this loop per cipher block. */
1672 /* Read another cipher-block's worth, and tack it onto the end. */
1673 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1674 while ((*datalen) == 0)
1676 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1679 /* Decrypt one more block (a little further back in the stream). */
1680 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1681 st->pktin->data + st->packetlen,
1683 /* Feed that block to the MAC. */
1684 ssh->scmac->bytes(ssh->sc_mac_ctx,
1685 st->pktin->data + st->packetlen, st->cipherblk);
1686 st->packetlen += st->cipherblk;
1687 /* See if that gives us a valid packet. */
1688 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1689 st->pktin->data + st->packetlen) &&
1690 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1693 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1694 bombout(("No valid incoming packet found"));
1695 ssh_free_packet(st->pktin);
1699 st->pktin->maxlen = st->packetlen + st->maclen;
1700 st->pktin->data = sresize(st->pktin->data,
1701 st->pktin->maxlen + APIEXTRA,
1703 } else if (ssh->scmac && ssh->scmac_etm) {
1704 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1707 * OpenSSH encrypt-then-MAC mode: the packet length is
1708 * unencrypted, unless the cipher supports length encryption.
1710 for (st->i = st->len = 0; st->i < 4; st->i++) {
1711 while ((*datalen) == 0)
1713 st->pktin->data[st->i] = *(*data)++;
1716 /* Cipher supports length decryption, so do it */
1717 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1718 /* Keep the packet the same though, so the MAC passes */
1719 unsigned char len[4];
1720 memcpy(len, st->pktin->data, 4);
1721 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1722 st->len = toint(GET_32BIT(len));
1724 st->len = toint(GET_32BIT(st->pktin->data));
1728 * _Completely_ silly lengths should be stomped on before they
1729 * do us any more damage.
1731 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1732 st->len % st->cipherblk != 0) {
1733 bombout(("Incoming packet length field was garbled"));
1734 ssh_free_packet(st->pktin);
1739 * So now we can work out the total packet length.
1741 st->packetlen = st->len + 4;
1744 * Allocate memory for the rest of the packet.
1746 st->pktin->maxlen = st->packetlen + st->maclen;
1747 st->pktin->data = sresize(st->pktin->data,
1748 st->pktin->maxlen + APIEXTRA,
1752 * Read the remainder of the packet.
1754 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1755 while ((*datalen) == 0)
1757 st->pktin->data[st->i] = *(*data)++;
1765 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1766 st->len + 4, st->incoming_sequence)) {
1767 bombout(("Incorrect MAC received on packet"));
1768 ssh_free_packet(st->pktin);
1772 /* Decrypt everything between the length field and the MAC. */
1774 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1775 st->pktin->data + 4,
1778 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1781 * Acquire and decrypt the first block of the packet. This will
1782 * contain the length and padding details.
1784 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1785 while ((*datalen) == 0)
1787 st->pktin->data[st->i] = *(*data)++;
1792 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1793 st->pktin->data, st->cipherblk);
1796 * Now get the length figure.
1798 st->len = toint(GET_32BIT(st->pktin->data));
1801 * _Completely_ silly lengths should be stomped on before they
1802 * do us any more damage.
1804 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1805 (st->len + 4) % st->cipherblk != 0) {
1806 bombout(("Incoming packet was garbled on decryption"));
1807 ssh_free_packet(st->pktin);
1812 * So now we can work out the total packet length.
1814 st->packetlen = st->len + 4;
1817 * Allocate memory for the rest of the packet.
1819 st->pktin->maxlen = st->packetlen + st->maclen;
1820 st->pktin->data = sresize(st->pktin->data,
1821 st->pktin->maxlen + APIEXTRA,
1825 * Read and decrypt the remainder of the packet.
1827 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1829 while ((*datalen) == 0)
1831 st->pktin->data[st->i] = *(*data)++;
1834 /* Decrypt everything _except_ the MAC. */
1836 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1837 st->pktin->data + st->cipherblk,
1838 st->packetlen - st->cipherblk);
1844 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1845 st->len + 4, st->incoming_sequence)) {
1846 bombout(("Incorrect MAC received on packet"));
1847 ssh_free_packet(st->pktin);
1851 /* Get and sanity-check the amount of random padding. */
1852 st->pad = st->pktin->data[4];
1853 if (st->pad < 4 || st->len - st->pad < 1) {
1854 bombout(("Invalid padding length on received packet"));
1855 ssh_free_packet(st->pktin);
1859 * This enables us to deduce the payload length.
1861 st->payload = st->len - st->pad - 1;
1863 st->pktin->length = st->payload + 5;
1864 st->pktin->encrypted_len = st->packetlen;
1866 st->pktin->sequence = st->incoming_sequence++;
1868 st->pktin->length = st->packetlen - st->pad;
1869 assert(st->pktin->length >= 0);
1872 * Decompress packet payload.
1875 unsigned char *newpayload;
1878 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1879 st->pktin->data + 5, st->pktin->length - 5,
1880 &newpayload, &newlen)) {
1881 if (st->pktin->maxlen < newlen + 5) {
1882 st->pktin->maxlen = newlen + 5;
1883 st->pktin->data = sresize(st->pktin->data,
1884 st->pktin->maxlen + APIEXTRA,
1887 st->pktin->length = 5 + newlen;
1888 memcpy(st->pktin->data + 5, newpayload, newlen);
1894 * RFC 4253 doesn't explicitly say that completely empty packets
1895 * with no type byte are forbidden, so treat them as deserving
1896 * an SSH_MSG_UNIMPLEMENTED.
1898 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1899 ssh2_msg_something_unimplemented(ssh, st->pktin);
1903 * pktin->body and pktin->length should identify the semantic
1904 * content of the packet, excluding the initial type byte.
1906 st->pktin->type = st->pktin->data[5];
1907 st->pktin->body = st->pktin->data + 6;
1908 st->pktin->length -= 6;
1909 assert(st->pktin->length >= 0); /* one last double-check */
1912 ssh2_log_incoming_packet(ssh, st->pktin);
1914 st->pktin->savedpos = 0;
1916 crFinish(st->pktin);
1919 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1920 const unsigned char **data,
1923 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1925 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1928 * Read the packet length field.
1930 for (st->i = 0; st->i < 4; st->i++) {
1931 while ((*datalen) == 0)
1933 st->length[st->i] = *(*data)++;
1937 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1938 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1939 bombout(("Invalid packet length received"));
1943 st->pktin = ssh_new_packet();
1944 st->pktin->data = snewn(st->packetlen, unsigned char);
1946 st->pktin->encrypted_len = st->packetlen;
1948 st->pktin->sequence = st->incoming_sequence++;
1951 * Read the remainder of the packet.
1953 for (st->i = 0; st->i < st->packetlen; st->i++) {
1954 while ((*datalen) == 0)
1956 st->pktin->data[st->i] = *(*data)++;
1961 * pktin->body and pktin->length should identify the semantic
1962 * content of the packet, excluding the initial type byte.
1964 st->pktin->type = st->pktin->data[0];
1965 st->pktin->body = st->pktin->data + 1;
1966 st->pktin->length = st->packetlen - 1;
1969 * Log incoming packet, possibly omitting sensitive fields.
1972 ssh2_log_incoming_packet(ssh, st->pktin);
1974 st->pktin->savedpos = 0;
1976 crFinish(st->pktin);
1979 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1981 int pad, biglen, i, pktoffs;
1985 * XXX various versions of SC (including 8.8.4) screw up the
1986 * register allocation in this function and use the same register
1987 * (D6) for len and as a temporary, with predictable results. The
1988 * following sledgehammer prevents this.
1995 ssh1_log_outgoing_packet(ssh, pkt);
1997 if (ssh->v1_compressing) {
1998 unsigned char *compblk;
2000 zlib_compress_block(ssh->cs_comp_ctx,
2001 pkt->data + 12, pkt->length - 12,
2002 &compblk, &complen);
2003 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
2004 memcpy(pkt->data + 12, compblk, complen);
2006 pkt->length = complen + 12;
2009 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
2011 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
2012 pad = 8 - (len % 8);
2014 biglen = len + pad; /* len(padding+type+data+CRC) */
2016 for (i = pktoffs; i < 4+8; i++)
2017 pkt->data[i] = random_byte();
2018 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
2019 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
2020 PUT_32BIT(pkt->data + pktoffs, len);
2023 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
2024 pkt->data + pktoffs + 4, biglen);
2026 if (offset_p) *offset_p = pktoffs;
2027 return biglen + 4; /* len(length+padding+type+data+CRC) */
2030 static int s_write(Ssh ssh, void *data, int len)
2033 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
2034 0, NULL, NULL, 0, NULL);
2037 return sk_write(ssh->s, (char *)data, len);
2040 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2042 int len, backlog, offset;
2043 len = s_wrpkt_prepare(ssh, pkt, &offset);
2044 backlog = s_write(ssh, pkt->data + offset, len);
2045 if (backlog > SSH_MAX_BACKLOG)
2046 ssh_throttle_all(ssh, 1, backlog);
2047 ssh_free_packet(pkt);
2050 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2053 len = s_wrpkt_prepare(ssh, pkt, &offset);
2054 if (ssh->deferred_len + len > ssh->deferred_size) {
2055 ssh->deferred_size = ssh->deferred_len + len + 128;
2056 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2060 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2061 pkt->data + offset, len);
2062 ssh->deferred_len += len;
2063 ssh_free_packet(pkt);
2067 * Construct a SSH-1 packet with the specified contents.
2068 * (This all-at-once interface used to be the only one, but now SSH-1
2069 * packets can also be constructed incrementally.)
2071 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2077 pkt = ssh1_pkt_init(pkttype);
2079 while ((argtype = va_arg(ap, int)) != PKT_END) {
2080 unsigned char *argp, argchar;
2082 unsigned long argint;
2085 /* Actual fields in the packet */
2087 argint = va_arg(ap, int);
2088 ssh_pkt_adduint32(pkt, argint);
2091 argchar = (unsigned char) va_arg(ap, int);
2092 ssh_pkt_addbyte(pkt, argchar);
2095 argp = va_arg(ap, unsigned char *);
2096 arglen = va_arg(ap, int);
2097 ssh_pkt_adddata(pkt, argp, arglen);
2100 sargp = va_arg(ap, char *);
2101 ssh_pkt_addstring(pkt, sargp);
2104 bn = va_arg(ap, Bignum);
2105 ssh1_pkt_addmp(pkt, bn);
2113 static void send_packet(Ssh ssh, int pkttype, ...)
2117 va_start(ap, pkttype);
2118 pkt = construct_packet(ssh, pkttype, ap);
2123 static void defer_packet(Ssh ssh, int pkttype, ...)
2127 va_start(ap, pkttype);
2128 pkt = construct_packet(ssh, pkttype, ap);
2130 s_wrpkt_defer(ssh, pkt);
2133 static int ssh_versioncmp(const char *a, const char *b)
2136 unsigned long av, bv;
2138 av = strtoul(a, &ae, 10);
2139 bv = strtoul(b, &be, 10);
2141 return (av < bv ? -1 : +1);
2146 av = strtoul(ae, &ae, 10);
2147 bv = strtoul(be, &be, 10);
2149 return (av < bv ? -1 : +1);
2154 * Utility routines for putting an SSH-protocol `string' and
2155 * `uint32' into a hash state.
2157 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2159 unsigned char lenblk[4];
2160 PUT_32BIT(lenblk, len);
2161 h->bytes(s, lenblk, 4);
2162 h->bytes(s, str, len);
2165 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2167 unsigned char intblk[4];
2168 PUT_32BIT(intblk, i);
2169 h->bytes(s, intblk, 4);
2173 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2175 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2177 if (pkt->maxlen < length) {
2178 unsigned char *body = pkt->body;
2179 int offset = body ? body - pkt->data : 0;
2180 pkt->maxlen = length + 256;
2181 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2182 if (body) pkt->body = pkt->data + offset;
2185 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2188 ssh_pkt_ensure(pkt, pkt->length);
2189 memcpy(pkt->data + pkt->length - len, data, len);
2191 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2193 ssh_pkt_adddata(pkt, &byte, 1);
2195 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2197 ssh_pkt_adddata(pkt, &value, 1);
2199 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2202 PUT_32BIT(x, value);
2203 ssh_pkt_adddata(pkt, x, 4);
2205 static void ssh_pkt_addstring_start(struct Packet *pkt)
2207 ssh_pkt_adduint32(pkt, 0);
2208 pkt->savedpos = pkt->length;
2210 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2213 ssh_pkt_adddata(pkt, data, len);
2214 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2216 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2218 ssh_pkt_addstring_data(pkt, data, strlen(data));
2220 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2222 ssh_pkt_addstring_start(pkt);
2223 ssh_pkt_addstring_str(pkt, data);
2225 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2227 int len = ssh1_bignum_length(b);
2228 unsigned char *data = snewn(len, unsigned char);
2229 (void) ssh1_write_bignum(data, b);
2230 ssh_pkt_adddata(pkt, data, len);
2233 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2236 int i, n = (bignum_bitcount(b) + 7) / 8;
2237 p = snewn(n + 1, unsigned char);
2239 for (i = 1; i <= n; i++)
2240 p[i] = bignum_byte(b, n - i);
2242 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2244 memmove(p, p + i, n + 1 - i);
2248 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2252 p = ssh2_mpint_fmt(b, &len);
2253 ssh_pkt_addstring_start(pkt);
2254 ssh_pkt_addstring_data(pkt, (char *)p, len);
2258 static struct Packet *ssh1_pkt_init(int pkt_type)
2260 struct Packet *pkt = ssh_new_packet();
2261 pkt->length = 4 + 8; /* space for length + max padding */
2262 ssh_pkt_addbyte(pkt, pkt_type);
2263 pkt->body = pkt->data + pkt->length;
2264 pkt->type = pkt_type;
2265 pkt->downstream_id = 0;
2266 pkt->additional_log_text = NULL;
2270 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2271 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2272 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2273 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2274 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2275 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2276 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2277 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2278 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2280 static struct Packet *ssh2_pkt_init(int pkt_type)
2282 struct Packet *pkt = ssh_new_packet();
2283 pkt->length = 5; /* space for packet length + padding length */
2285 pkt->type = pkt_type;
2286 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2287 pkt->body = pkt->data + pkt->length; /* after packet type */
2288 pkt->downstream_id = 0;
2289 pkt->additional_log_text = NULL;
2294 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2295 * put the MAC on it. Final packet, ready to be sent, is stored in
2296 * pkt->data. Total length is returned.
2298 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2300 int cipherblk, maclen, padding, unencrypted_prefix, i;
2303 ssh2_log_outgoing_packet(ssh, pkt);
2305 if (ssh->bare_connection) {
2307 * Trivial packet construction for the bare connection
2310 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2311 pkt->body = pkt->data + 1;
2312 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2313 return pkt->length - 1;
2317 * Compress packet payload.
2320 unsigned char *newpayload;
2323 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2325 &newpayload, &newlen)) {
2327 ssh2_pkt_adddata(pkt, newpayload, newlen);
2333 * Add padding. At least four bytes, and must also bring total
2334 * length (minus MAC) up to a multiple of the block size.
2335 * If pkt->forcepad is set, make sure the packet is at least that size
2338 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2339 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2341 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2342 if (pkt->length + padding < pkt->forcepad)
2343 padding = pkt->forcepad - pkt->length;
2345 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2347 assert(padding <= 255);
2348 maclen = ssh->csmac ? ssh->csmac->len : 0;
2349 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2350 pkt->data[4] = padding;
2351 for (i = 0; i < padding; i++)
2352 pkt->data[pkt->length + i] = random_byte();
2353 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2355 /* Encrypt length if the scheme requires it */
2356 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2357 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2358 ssh->v2_outgoing_sequence);
2361 if (ssh->csmac && ssh->csmac_etm) {
2363 * OpenSSH-defined encrypt-then-MAC protocol.
2366 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2367 pkt->data + 4, pkt->length + padding - 4);
2368 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2369 pkt->length + padding,
2370 ssh->v2_outgoing_sequence);
2373 * SSH-2 standard protocol.
2376 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2377 pkt->length + padding,
2378 ssh->v2_outgoing_sequence);
2380 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2381 pkt->data, pkt->length + padding);
2384 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2385 pkt->encrypted_len = pkt->length + padding;
2387 /* Ready-to-send packet starts at pkt->data. We return length. */
2388 pkt->body = pkt->data;
2389 return pkt->length + padding + maclen;
2393 * Routines called from the main SSH code to send packets. There
2394 * are quite a few of these, because we have two separate
2395 * mechanisms for delaying the sending of packets:
2397 * - In order to send an IGNORE message and a password message in
2398 * a single fixed-length blob, we require the ability to
2399 * concatenate the encrypted forms of those two packets _into_ a
2400 * single blob and then pass it to our <network.h> transport
2401 * layer in one go. Hence, there's a deferment mechanism which
2402 * works after packet encryption.
2404 * - In order to avoid sending any connection-layer messages
2405 * during repeat key exchange, we have to queue up any such
2406 * outgoing messages _before_ they are encrypted (and in
2407 * particular before they're allocated sequence numbers), and
2408 * then send them once we've finished.
2410 * I call these mechanisms `defer' and `queue' respectively, so as
2411 * to distinguish them reasonably easily.
2413 * The functions send_noqueue() and defer_noqueue() free the packet
2414 * structure they are passed. Every outgoing packet goes through
2415 * precisely one of these functions in its life; packets passed to
2416 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2417 * these or get queued, and then when the queue is later emptied
2418 * the packets are all passed to defer_noqueue().
2420 * When using a CBC-mode cipher, it's necessary to ensure that an
2421 * attacker can't provide data to be encrypted using an IV that they
2422 * know. We ensure this by prefixing each packet that might contain
2423 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2424 * mechanism, so in this case send_noqueue() ends up redirecting to
2425 * defer_noqueue(). If you don't like this inefficiency, don't use
2429 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2430 static void ssh_pkt_defersend(Ssh);
2433 * Send an SSH-2 packet immediately, without queuing or deferring.
2435 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2439 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2440 /* We need to send two packets, so use the deferral mechanism. */
2441 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2442 ssh_pkt_defersend(ssh);
2445 len = ssh2_pkt_construct(ssh, pkt);
2446 backlog = s_write(ssh, pkt->body, len);
2447 if (backlog > SSH_MAX_BACKLOG)
2448 ssh_throttle_all(ssh, 1, backlog);
2450 ssh->outgoing_data_size += pkt->encrypted_len;
2451 if (!ssh->kex_in_progress &&
2452 !ssh->bare_connection &&
2453 ssh->max_data_size != 0 &&
2454 ssh->outgoing_data_size > ssh->max_data_size)
2455 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2457 ssh_free_packet(pkt);
2461 * Defer an SSH-2 packet.
2463 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2466 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2467 ssh->deferred_len == 0 && !noignore &&
2468 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2470 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2471 * get encrypted with a known IV.
2473 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2474 ssh2_pkt_addstring_start(ipkt);
2475 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2477 len = ssh2_pkt_construct(ssh, pkt);
2478 if (ssh->deferred_len + len > ssh->deferred_size) {
2479 ssh->deferred_size = ssh->deferred_len + len + 128;
2480 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2484 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2485 ssh->deferred_len += len;
2486 ssh->deferred_data_size += pkt->encrypted_len;
2487 ssh_free_packet(pkt);
2491 * Queue an SSH-2 packet.
2493 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2495 assert(ssh->queueing);
2497 if (ssh->queuelen >= ssh->queuesize) {
2498 ssh->queuesize = ssh->queuelen + 32;
2499 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2502 ssh->queue[ssh->queuelen++] = pkt;
2506 * Either queue or send a packet, depending on whether queueing is
2509 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2512 ssh2_pkt_queue(ssh, pkt);
2514 ssh2_pkt_send_noqueue(ssh, pkt);
2518 * Either queue or defer a packet, depending on whether queueing is
2521 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2524 ssh2_pkt_queue(ssh, pkt);
2526 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2530 * Send the whole deferred data block constructed by
2531 * ssh2_pkt_defer() or SSH-1's defer_packet().
2533 * The expected use of the defer mechanism is that you call
2534 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2535 * not currently queueing, this simply sets up deferred_send_data
2536 * and then sends it. If we _are_ currently queueing, the calls to
2537 * ssh2_pkt_defer() put the deferred packets on to the queue
2538 * instead, and therefore ssh_pkt_defersend() has no deferred data
2539 * to send. Hence, there's no need to make it conditional on
2542 static void ssh_pkt_defersend(Ssh ssh)
2545 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2546 ssh->deferred_len = ssh->deferred_size = 0;
2547 sfree(ssh->deferred_send_data);
2548 ssh->deferred_send_data = NULL;
2549 if (backlog > SSH_MAX_BACKLOG)
2550 ssh_throttle_all(ssh, 1, backlog);
2552 if (ssh->version == 2) {
2553 ssh->outgoing_data_size += ssh->deferred_data_size;
2554 ssh->deferred_data_size = 0;
2555 if (!ssh->kex_in_progress &&
2556 !ssh->bare_connection &&
2557 ssh->max_data_size != 0 &&
2558 ssh->outgoing_data_size > ssh->max_data_size)
2559 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2564 * Send a packet whose length needs to be disguised (typically
2565 * passwords or keyboard-interactive responses).
2567 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2573 * The simplest way to do this is to adjust the
2574 * variable-length padding field in the outgoing packet.
2576 * Currently compiled out, because some Cisco SSH servers
2577 * don't like excessively padded packets (bah, why's it
2580 pkt->forcepad = padsize;
2581 ssh2_pkt_send(ssh, pkt);
2586 * If we can't do that, however, an alternative approach is
2587 * to use the pkt_defer mechanism to bundle the packet
2588 * tightly together with an SSH_MSG_IGNORE such that their
2589 * combined length is a constant. So first we construct the
2590 * final form of this packet and defer its sending.
2592 ssh2_pkt_defer(ssh, pkt);
2595 * Now construct an SSH_MSG_IGNORE which includes a string
2596 * that's an exact multiple of the cipher block size. (If
2597 * the cipher is NULL so that the block size is
2598 * unavailable, we don't do this trick at all, because we
2599 * gain nothing by it.)
2601 if (ssh->cscipher &&
2602 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2605 stringlen = (256 - ssh->deferred_len);
2606 stringlen += ssh->cscipher->blksize - 1;
2607 stringlen -= (stringlen % ssh->cscipher->blksize);
2610 * Temporarily disable actual compression, so we
2611 * can guarantee to get this string exactly the
2612 * length we want it. The compression-disabling
2613 * routine should return an integer indicating how
2614 * many bytes we should adjust our string length
2618 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2620 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2621 ssh2_pkt_addstring_start(pkt);
2622 for (i = 0; i < stringlen; i++) {
2623 char c = (char) random_byte();
2624 ssh2_pkt_addstring_data(pkt, &c, 1);
2626 ssh2_pkt_defer(ssh, pkt);
2628 ssh_pkt_defersend(ssh);
2633 * Send all queued SSH-2 packets. We send them by means of
2634 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2635 * packets that needed to be lumped together.
2637 static void ssh2_pkt_queuesend(Ssh ssh)
2641 assert(!ssh->queueing);
2643 for (i = 0; i < ssh->queuelen; i++)
2644 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2647 ssh_pkt_defersend(ssh);
2651 void bndebug(char *string, Bignum b)
2655 p = ssh2_mpint_fmt(b, &len);
2656 debug(("%s", string));
2657 for (i = 0; i < len; i++)
2658 debug((" %02x", p[i]));
2664 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2668 p = ssh2_mpint_fmt(b, &len);
2669 hash_string(h, s, p, len);
2674 * Packet decode functions for both SSH-1 and SSH-2.
2676 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2678 unsigned long value;
2679 if (pkt->length - pkt->savedpos < 4)
2680 return 0; /* arrgh, no way to decline (FIXME?) */
2681 value = GET_32BIT(pkt->body + pkt->savedpos);
2685 static int ssh2_pkt_getbool(struct Packet *pkt)
2687 unsigned long value;
2688 if (pkt->length - pkt->savedpos < 1)
2689 return 0; /* arrgh, no way to decline (FIXME?) */
2690 value = pkt->body[pkt->savedpos] != 0;
2694 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2699 if (pkt->length - pkt->savedpos < 4)
2701 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2706 if (pkt->length - pkt->savedpos < *length)
2708 *p = (char *)(pkt->body + pkt->savedpos);
2709 pkt->savedpos += *length;
2711 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2713 if (pkt->length - pkt->savedpos < length)
2715 pkt->savedpos += length;
2716 return pkt->body + (pkt->savedpos - length);
2718 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2719 const unsigned char **keystr)
2723 j = makekey(pkt->body + pkt->savedpos,
2724 pkt->length - pkt->savedpos,
2731 assert(pkt->savedpos < pkt->length);
2735 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2740 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2741 pkt->length - pkt->savedpos, &b);
2749 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2755 ssh_pkt_getstring(pkt, &p, &length);
2760 b = bignum_from_bytes((unsigned char *)p, length);
2765 * Helper function to add an SSH-2 signature blob to a packet.
2766 * Expects to be shown the public key blob as well as the signature
2767 * blob. Normally works just like ssh2_pkt_addstring, but will
2768 * fiddle with the signature packet if necessary for
2769 * BUG_SSH2_RSA_PADDING.
2771 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2772 void *pkblob_v, int pkblob_len,
2773 void *sigblob_v, int sigblob_len)
2775 unsigned char *pkblob = (unsigned char *)pkblob_v;
2776 unsigned char *sigblob = (unsigned char *)sigblob_v;
2778 /* dmemdump(pkblob, pkblob_len); */
2779 /* dmemdump(sigblob, sigblob_len); */
2782 * See if this is in fact an ssh-rsa signature and a buggy
2783 * server; otherwise we can just do this the easy way.
2785 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2786 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2787 int pos, len, siglen;
2790 * Find the byte length of the modulus.
2793 pos = 4+7; /* skip over "ssh-rsa" */
2794 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2795 if (len < 0 || len > pkblob_len - pos - 4)
2797 pos += 4 + len; /* skip over exponent */
2798 if (pkblob_len - pos < 4)
2800 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2801 if (len < 0 || len > pkblob_len - pos - 4)
2803 pos += 4; /* find modulus itself */
2804 while (len > 0 && pkblob[pos] == 0)
2806 /* debug(("modulus length is %d\n", len)); */
2809 * Now find the signature integer.
2811 pos = 4+7; /* skip over "ssh-rsa" */
2812 if (sigblob_len < pos+4)
2814 siglen = toint(GET_32BIT(sigblob+pos));
2815 if (siglen != sigblob_len - pos - 4)
2817 /* debug(("signature length is %d\n", siglen)); */
2819 if (len != siglen) {
2820 unsigned char newlen[4];
2821 ssh2_pkt_addstring_start(pkt);
2822 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2823 /* dmemdump(sigblob, pos); */
2824 pos += 4; /* point to start of actual sig */
2825 PUT_32BIT(newlen, len);
2826 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2827 /* dmemdump(newlen, 4); */
2829 while (len-- > siglen) {
2830 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2831 /* dmemdump(newlen, 1); */
2833 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2834 /* dmemdump(sigblob+pos, siglen); */
2838 /* Otherwise fall through and do it the easy way. We also come
2839 * here as a fallback if we discover above that the key blob
2840 * is misformatted in some way. */
2844 ssh2_pkt_addstring_start(pkt);
2845 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2849 * Examine the remote side's version string and compare it against
2850 * a list of known buggy implementations.
2852 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2854 char *imp; /* pointer to implementation part */
2856 imp += strcspn(imp, "-");
2858 imp += strcspn(imp, "-");
2861 ssh->remote_bugs = 0;
2864 * General notes on server version strings:
2865 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2866 * here -- in particular, we've heard of one that's perfectly happy
2867 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2868 * so we can't distinguish them.
2870 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2871 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2872 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2873 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2874 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2875 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2877 * These versions don't support SSH1_MSG_IGNORE, so we have
2878 * to use a different defence against password length
2881 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2882 logevent("We believe remote version has SSH-1 ignore bug");
2885 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2886 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2887 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2889 * These versions need a plain password sent; they can't
2890 * handle having a null and a random length of data after
2893 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2894 logevent("We believe remote version needs a plain SSH-1 password");
2897 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2898 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2899 (!strcmp(imp, "Cisco-1.25")))) {
2901 * These versions apparently have no clue whatever about
2902 * RSA authentication and will panic and die if they see
2903 * an AUTH_RSA message.
2905 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2906 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2909 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2910 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2911 !wc_match("* VShell", imp) &&
2912 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2913 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2914 wc_match("2.1 *", imp)))) {
2916 * These versions have the HMAC bug.
2918 ssh->remote_bugs |= BUG_SSH2_HMAC;
2919 logevent("We believe remote version has SSH-2 HMAC bug");
2922 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2923 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2924 !wc_match("* VShell", imp) &&
2925 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2927 * These versions have the key-derivation bug (failing to
2928 * include the literal shared secret in the hashes that
2929 * generate the keys).
2931 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2932 logevent("We believe remote version has SSH-2 key-derivation bug");
2935 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2936 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2937 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2938 wc_match("OpenSSH_3.[0-2]*", imp) ||
2939 wc_match("mod_sftp/0.[0-8]*", imp) ||
2940 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2942 * These versions have the SSH-2 RSA padding bug.
2944 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2945 logevent("We believe remote version has SSH-2 RSA padding bug");
2948 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2949 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2950 wc_match("OpenSSH_2.[0-2]*", imp))) {
2952 * These versions have the SSH-2 session-ID bug in
2953 * public-key authentication.
2955 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2956 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2959 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2960 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2961 (wc_match("DigiSSH_2.0", imp) ||
2962 wc_match("OpenSSH_2.[0-4]*", imp) ||
2963 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2964 wc_match("Sun_SSH_1.0", imp) ||
2965 wc_match("Sun_SSH_1.0.1", imp) ||
2966 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2967 wc_match("WeOnlyDo-*", imp)))) {
2969 * These versions have the SSH-2 rekey bug.
2971 ssh->remote_bugs |= BUG_SSH2_REKEY;
2972 logevent("We believe remote version has SSH-2 rekey bug");
2975 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2976 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2977 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2978 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2980 * This version ignores our makpkt and needs to be throttled.
2982 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2983 logevent("We believe remote version ignores SSH-2 maximum packet size");
2986 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2988 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2989 * none detected automatically.
2991 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2992 logevent("We believe remote version has SSH-2 ignore bug");
2995 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2996 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2997 (wc_match("OpenSSH_2.[235]*", imp)))) {
2999 * These versions only support the original (pre-RFC4419)
3000 * SSH-2 GEX request, and disconnect with a protocol error if
3001 * we use the newer version.
3003 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
3004 logevent("We believe remote version has outdated SSH-2 GEX");
3007 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
3009 * Servers that don't support our winadj request for one
3010 * reason or another. Currently, none detected automatically.
3012 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
3013 logevent("We believe remote version has winadj bug");
3016 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
3017 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
3018 (wc_match("OpenSSH_[2-5].*", imp) ||
3019 wc_match("OpenSSH_6.[0-6]*", imp) ||
3020 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
3021 wc_match("dropbear_0.5[01]*", imp)))) {
3023 * These versions have the SSH-2 channel request bug.
3024 * OpenSSH 6.7 and above do not:
3025 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
3026 * dropbear_0.52 and above do not:
3027 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
3029 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
3030 logevent("We believe remote version has SSH-2 channel request bug");
3035 * The `software version' part of an SSH version string is required
3036 * to contain no spaces or minus signs.
3038 static void ssh_fix_verstring(char *str)
3040 /* Eat "<protoversion>-". */
3041 while (*str && *str != '-') str++;
3042 assert(*str == '-'); str++;
3044 /* Convert minus signs and spaces in the remaining string into
3047 if (*str == '-' || *str == ' ')
3054 * Send an appropriate SSH version string.
3056 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3060 if (ssh->version == 2) {
3062 * Construct a v2 version string.
3064 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3067 * Construct a v1 version string.
3069 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3070 verstring = dupprintf("SSH-%s-%s\012",
3071 (ssh_versioncmp(svers, "1.5") <= 0 ?
3076 ssh_fix_verstring(verstring + strlen(protoname));
3078 /* FUZZING make PuTTY insecure, so make live use difficult. */
3082 if (ssh->version == 2) {
3085 * Record our version string.
3087 len = strcspn(verstring, "\015\012");
3088 ssh->v_c = snewn(len + 1, char);
3089 memcpy(ssh->v_c, verstring, len);
3093 logeventf(ssh, "We claim version: %.*s",
3094 strcspn(verstring, "\015\012"), verstring);
3095 s_write(ssh, verstring, strlen(verstring));
3099 static int do_ssh_init(Ssh ssh, unsigned char c)
3101 static const char protoname[] = "SSH-";
3103 struct do_ssh_init_state {
3112 crState(do_ssh_init_state);
3116 /* Search for a line beginning with the protocol name prefix in
3119 for (s->i = 0; protoname[s->i]; s->i++) {
3120 if ((char)c != protoname[s->i]) goto no;
3130 ssh->session_started = TRUE;
3132 s->vstrsize = sizeof(protoname) + 16;
3133 s->vstring = snewn(s->vstrsize, char);
3134 strcpy(s->vstring, protoname);
3135 s->vslen = strlen(protoname);
3138 if (s->vslen >= s->vstrsize - 1) {
3140 s->vstring = sresize(s->vstring, s->vstrsize, char);
3142 s->vstring[s->vslen++] = c;
3145 s->version[s->i] = '\0';
3147 } else if (s->i < sizeof(s->version) - 1)
3148 s->version[s->i++] = c;
3149 } else if (c == '\012')
3151 crReturn(1); /* get another char */
3154 ssh->agentfwd_enabled = FALSE;
3155 ssh->rdpkt2_state.incoming_sequence = 0;
3157 s->vstring[s->vslen] = 0;
3158 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3159 logeventf(ssh, "Server version: %s", s->vstring);
3160 ssh_detect_bugs(ssh, s->vstring);
3163 * Decide which SSH protocol version to support.
3166 /* Anything strictly below "2.0" means protocol 1 is supported. */
3167 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3168 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3169 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3171 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3173 bombout(("SSH protocol version 1 required by our configuration "
3174 "but not provided by server"));
3177 } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) {
3179 bombout(("SSH protocol version 2 required by our configuration "
3180 "but server only provides (old, insecure) SSH-1"));
3184 /* No longer support values 1 or 2 for CONF_sshprot */
3185 assert(!"Unexpected value for CONF_sshprot");
3188 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3193 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3195 /* Send the version string, if we haven't already */
3196 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3197 ssh_send_verstring(ssh, protoname, s->version);
3199 if (ssh->version == 2) {
3202 * Record their version string.
3204 len = strcspn(s->vstring, "\015\012");
3205 ssh->v_s = snewn(len + 1, char);
3206 memcpy(ssh->v_s, s->vstring, len);
3210 * Initialise SSH-2 protocol.
3212 ssh->protocol = ssh2_protocol;
3213 ssh2_protocol_setup(ssh);
3214 ssh->s_rdpkt = ssh2_rdpkt;
3217 * Initialise SSH-1 protocol.
3219 ssh->protocol = ssh1_protocol;
3220 ssh1_protocol_setup(ssh);
3221 ssh->s_rdpkt = ssh1_rdpkt;
3223 if (ssh->version == 2)
3224 do_ssh2_transport(ssh, NULL, -1, NULL);
3226 update_specials_menu(ssh->frontend);
3227 ssh->state = SSH_STATE_BEFORE_SIZE;
3228 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3235 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3238 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3239 * the ssh-connection part, extracted and given a trivial binary
3240 * packet protocol, so we replace 'SSH-' at the start with a new
3241 * name. In proper SSH style (though of course this part of the
3242 * proper SSH protocol _isn't_ subject to this kind of
3243 * DNS-domain-based extension), we define the new name in our
3246 static const char protoname[] =
3247 "SSHCONNECTION@putty.projects.tartarus.org-";
3249 struct do_ssh_connection_init_state {
3257 crState(do_ssh_connection_init_state);
3261 /* Search for a line beginning with the protocol name prefix in
3264 for (s->i = 0; protoname[s->i]; s->i++) {
3265 if ((char)c != protoname[s->i]) goto no;
3275 s->vstrsize = sizeof(protoname) + 16;
3276 s->vstring = snewn(s->vstrsize, char);
3277 strcpy(s->vstring, protoname);
3278 s->vslen = strlen(protoname);
3281 if (s->vslen >= s->vstrsize - 1) {
3283 s->vstring = sresize(s->vstring, s->vstrsize, char);
3285 s->vstring[s->vslen++] = c;
3288 s->version[s->i] = '\0';
3290 } else if (s->i < sizeof(s->version) - 1)
3291 s->version[s->i++] = c;
3292 } else if (c == '\012')
3294 crReturn(1); /* get another char */
3297 ssh->agentfwd_enabled = FALSE;
3298 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3300 s->vstring[s->vslen] = 0;
3301 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3302 logeventf(ssh, "Server version: %s", s->vstring);
3303 ssh_detect_bugs(ssh, s->vstring);
3306 * Decide which SSH protocol version to support. This is easy in
3307 * bare ssh-connection mode: only 2.0 is legal.
3309 if (ssh_versioncmp(s->version, "2.0") < 0) {
3310 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3313 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3314 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3320 logeventf(ssh, "Using bare ssh-connection protocol");
3322 /* Send the version string, if we haven't already */
3323 ssh_send_verstring(ssh, protoname, s->version);
3326 * Initialise bare connection protocol.
3328 ssh->protocol = ssh2_bare_connection_protocol;
3329 ssh2_bare_connection_protocol_setup(ssh);
3330 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3332 update_specials_menu(ssh->frontend);
3333 ssh->state = SSH_STATE_BEFORE_SIZE;
3334 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3337 * Get authconn (really just conn) under way.
3339 do_ssh2_authconn(ssh, NULL, 0, NULL);
3346 static void ssh_process_incoming_data(Ssh ssh,
3347 const unsigned char **data, int *datalen)
3349 struct Packet *pktin;
3351 pktin = ssh->s_rdpkt(ssh, data, datalen);
3353 ssh->protocol(ssh, NULL, 0, pktin);
3354 ssh_free_packet(pktin);
3358 static void ssh_queue_incoming_data(Ssh ssh,
3359 const unsigned char **data, int *datalen)
3361 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3366 static void ssh_process_queued_incoming_data(Ssh ssh)
3369 const unsigned char *data;
3372 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3373 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3377 while (!ssh->frozen && len > 0)
3378 ssh_process_incoming_data(ssh, &data, &len);
3381 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3385 static void ssh_set_frozen(Ssh ssh, int frozen)
3388 sk_set_frozen(ssh->s, frozen);
3389 ssh->frozen = frozen;
3392 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3394 /* Log raw data, if we're in that mode. */
3396 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3397 0, NULL, NULL, 0, NULL);
3399 crBegin(ssh->ssh_gotdata_crstate);
3402 * To begin with, feed the characters one by one to the
3403 * protocol initialisation / selection function do_ssh_init().
3404 * When that returns 0, we're done with the initial greeting
3405 * exchange and can move on to packet discipline.
3408 int ret; /* need not be kept across crReturn */
3410 crReturnV; /* more data please */
3411 ret = ssh->do_ssh_init(ssh, *data);
3419 * We emerge from that loop when the initial negotiation is
3420 * over and we have selected an s_rdpkt function. Now pass
3421 * everything to s_rdpkt, and then pass the resulting packets
3422 * to the proper protocol handler.
3426 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3428 ssh_queue_incoming_data(ssh, &data, &datalen);
3429 /* This uses up all data and cannot cause anything interesting
3430 * to happen; indeed, for anything to happen at all, we must
3431 * return, so break out. */
3433 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3434 /* This uses up some or all data, and may freeze the
3436 ssh_process_queued_incoming_data(ssh);
3438 /* This uses up some or all data, and may freeze the
3440 ssh_process_incoming_data(ssh, &data, &datalen);
3442 /* FIXME this is probably EBW. */
3443 if (ssh->state == SSH_STATE_CLOSED)
3446 /* We're out of data. Go and get some more. */
3452 static int ssh_do_close(Ssh ssh, int notify_exit)
3455 struct ssh_channel *c;
3457 ssh->state = SSH_STATE_CLOSED;
3458 expire_timer_context(ssh);
3463 notify_remote_exit(ssh->frontend);
3468 * Now we must shut down any port- and X-forwarded channels going
3469 * through this connection.
3471 if (ssh->channels) {
3472 while (NULL != (c = index234(ssh->channels, 0))) {
3473 ssh_channel_close_local(c, NULL);
3474 del234(ssh->channels, c); /* moving next one to index 0 */
3475 if (ssh->version == 2)
3476 bufchain_clear(&c->v.v2.outbuffer);
3481 * Go through port-forwardings, and close any associated
3482 * listening sockets.
3484 if (ssh->portfwds) {
3485 struct ssh_portfwd *pf;
3486 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3487 /* Dispose of any listening socket. */
3489 pfl_terminate(pf->local);
3490 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3493 freetree234(ssh->portfwds);
3494 ssh->portfwds = NULL;
3498 * Also stop attempting to connection-share.
3500 if (ssh->connshare) {
3501 sharestate_free(ssh->connshare);
3502 ssh->connshare = NULL;
3508 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3509 const char *error_msg, int error_code)
3511 Ssh ssh = (Ssh) plug;
3514 * While we're attempting connection sharing, don't loudly log
3515 * everything that happens. Real TCP connections need to be logged
3516 * when we _start_ trying to connect, because it might be ages
3517 * before they respond if something goes wrong; but connection
3518 * sharing is local and quick to respond, and it's sufficient to
3519 * simply wait and see whether it worked afterwards.
3522 if (!ssh->attempting_connshare)
3523 backend_socket_log(ssh->frontend, type, addr, port,
3524 error_msg, error_code, ssh->conf,
3525 ssh->session_started);
3528 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3529 const char *ds_err, const char *us_err)
3531 if (event == SHARE_NONE) {
3532 /* In this case, 'logtext' is an error message indicating a
3533 * reason why connection sharing couldn't be set up _at all_.
3534 * Failing that, ds_err and us_err indicate why we couldn't be
3535 * a downstream and an upstream respectively. */
3537 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3540 logeventf(ssh, "Could not set up connection sharing"
3541 " as downstream: %s", ds_err);
3543 logeventf(ssh, "Could not set up connection sharing"
3544 " as upstream: %s", us_err);
3546 } else if (event == SHARE_DOWNSTREAM) {
3547 /* In this case, 'logtext' is a local endpoint address */
3548 logeventf(ssh, "Using existing shared connection at %s", logtext);
3549 /* Also we should mention this in the console window to avoid
3550 * confusing users as to why this window doesn't behave the
3552 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3553 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3555 } else if (event == SHARE_UPSTREAM) {
3556 /* In this case, 'logtext' is a local endpoint address too */
3557 logeventf(ssh, "Sharing this connection at %s", logtext);
3561 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3564 Ssh ssh = (Ssh) plug;
3565 int need_notify = ssh_do_close(ssh, FALSE);
3568 if (!ssh->close_expected)
3569 error_msg = "Server unexpectedly closed network connection";
3571 error_msg = "Server closed network connection";
3574 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3578 notify_remote_exit(ssh->frontend);
3581 logevent(error_msg);
3582 if (!ssh->close_expected || !ssh->clean_exit)
3583 connection_fatal(ssh->frontend, "%s", error_msg);
3587 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3589 Ssh ssh = (Ssh) plug;
3590 ssh_gotdata(ssh, (unsigned char *)data, len);
3591 if (ssh->state == SSH_STATE_CLOSED) {
3592 ssh_do_close(ssh, TRUE);
3598 static void ssh_sent(Plug plug, int bufsize)
3600 Ssh ssh = (Ssh) plug;
3602 * If the send backlog on the SSH socket itself clears, we
3603 * should unthrottle the whole world if it was throttled.
3605 if (bufsize < SSH_MAX_BACKLOG)
3606 ssh_throttle_all(ssh, 0, bufsize);
3609 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3610 char **savedhost, int *savedport,
3613 char *loghost = conf_get_str(conf, CONF_loghost);
3615 *loghost_ret = loghost;
3621 tmphost = dupstr(loghost);
3622 *savedport = 22; /* default ssh port */
3625 * A colon suffix on the hostname string also lets us affect
3626 * savedport. (Unless there are multiple colons, in which case
3627 * we assume this is an unbracketed IPv6 literal.)
3629 colon = host_strrchr(tmphost, ':');
3630 if (colon && colon == host_strchr(tmphost, ':')) {
3633 *savedport = atoi(colon);
3636 *savedhost = host_strduptrim(tmphost);
3639 *savedhost = host_strduptrim(host);
3641 port = 22; /* default ssh port */
3646 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3652 random_ref(); /* platform may need this to determine share socket name */
3653 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3654 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3662 * Connect to specified host and port.
3663 * Returns an error message, or NULL on success.
3664 * Also places the canonical host name into `realhost'. It must be
3665 * freed by the caller.
3667 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3668 char **realhost, int nodelay, int keepalive)
3670 static const struct plug_function_table fn_table = {
3681 int addressfamily, sshprot;
3683 ssh_hostport_setup(host, port, ssh->conf,
3684 &ssh->savedhost, &ssh->savedport, &loghost);
3686 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3689 * Try connection-sharing, in case that means we don't open a
3690 * socket after all. ssh_connection_sharing_init will connect to a
3691 * previously established upstream if it can, and failing that,
3692 * establish a listening socket for _us_ to be the upstream. In
3693 * the latter case it will return NULL just as if it had done
3694 * nothing, because here we only need to care if we're a
3695 * downstream and need to do our connection setup differently.
3697 ssh->connshare = NULL;
3698 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3699 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3700 ssh->conf, ssh, &ssh->connshare);
3701 ssh->attempting_connshare = FALSE;
3702 if (ssh->s != NULL) {
3704 * We are a downstream.
3706 ssh->bare_connection = TRUE;
3707 ssh->do_ssh_init = do_ssh_connection_init;
3708 ssh->fullhostname = NULL;
3709 *realhost = dupstr(host); /* best we can do */
3712 * We're not a downstream, so open a normal socket.
3714 ssh->do_ssh_init = do_ssh_init;
3719 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3720 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3721 ssh->frontend, "SSH connection");
3722 if ((err = sk_addr_error(addr)) != NULL) {
3726 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3728 ssh->s = new_connection(addr, *realhost, port,
3729 0, 1, nodelay, keepalive,
3730 (Plug) ssh, ssh->conf);
3731 if ((err = sk_socket_error(ssh->s)) != NULL) {
3733 notify_remote_exit(ssh->frontend);
3739 * The SSH version number is always fixed (since we no longer support
3740 * fallback between versions), so set it now, and if it's SSH-2,
3741 * send the version string now too.
3743 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3744 assert(sshprot == 0 || sshprot == 3);
3748 if (sshprot == 3 && !ssh->bare_connection) {
3751 ssh_send_verstring(ssh, "SSH-", NULL);
3755 * loghost, if configured, overrides realhost.
3759 *realhost = dupstr(loghost);
3766 * Throttle or unthrottle the SSH connection.
3768 static void ssh_throttle_conn(Ssh ssh, int adjust)
3770 int old_count = ssh->conn_throttle_count;
3771 ssh->conn_throttle_count += adjust;
3772 assert(ssh->conn_throttle_count >= 0);
3773 if (ssh->conn_throttle_count && !old_count) {
3774 ssh_set_frozen(ssh, 1);
3775 } else if (!ssh->conn_throttle_count && old_count) {
3776 ssh_set_frozen(ssh, 0);
3780 static void ssh_agentf_try_forward(struct ssh_channel *c);
3783 * Throttle or unthrottle _all_ local data streams (for when sends
3784 * on the SSH connection itself back up).
3786 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3789 struct ssh_channel *c;
3791 if (enable == ssh->throttled_all)
3793 ssh->throttled_all = enable;
3794 ssh->overall_bufsize = bufsize;
3797 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3799 case CHAN_MAINSESSION:
3801 * This is treated separately, outside the switch.
3805 x11_override_throttle(c->u.x11.xconn, enable);
3808 /* Agent forwarding channels are buffer-managed by
3809 * checking ssh->throttled_all in ssh_agentf_try_forward.
3810 * So at the moment we _un_throttle again, we must make an
3811 * attempt to do something. */
3813 ssh_agentf_try_forward(c);
3816 pfd_override_throttle(c->u.pfd.pf, enable);
3822 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3824 Ssh ssh = (Ssh) sshv;
3826 ssh->auth_agent_query = NULL;
3828 ssh->agent_response = reply;
3829 ssh->agent_response_len = replylen;
3831 if (ssh->version == 1)
3832 do_ssh1_login(ssh, NULL, -1, NULL);
3834 do_ssh2_authconn(ssh, NULL, -1, NULL);
3837 static void ssh_dialog_callback(void *sshv, int ret)
3839 Ssh ssh = (Ssh) sshv;
3841 ssh->user_response = ret;
3843 if (ssh->version == 1)
3844 do_ssh1_login(ssh, NULL, -1, NULL);
3846 do_ssh2_transport(ssh, NULL, -1, NULL);
3849 * This may have unfrozen the SSH connection, so do a
3852 ssh_process_queued_incoming_data(ssh);
3855 static void ssh_agentf_got_response(struct ssh_channel *c,
3856 void *reply, int replylen)
3858 c->u.a.pending = NULL;
3861 /* The real agent didn't send any kind of reply at all for
3862 * some reason, so fake an SSH_AGENT_FAILURE. */
3863 reply = "\0\0\0\1\5";
3867 ssh_send_channel_data(c, reply, replylen);
3870 static void ssh_agentf_callback(void *cv, void *reply, int replylen);
3872 static void ssh_agentf_try_forward(struct ssh_channel *c)
3874 unsigned datalen, lengthfield, messagelen;
3875 unsigned char *message;
3876 unsigned char msglen[4];
3881 * Don't try to parallelise agent requests. Wait for each one to
3882 * return before attempting the next.
3888 * If the outgoing side of the channel connection is currently
3889 * throttled (for any reason, either that channel's window size or
3890 * the entire SSH connection being throttled), don't submit any
3891 * new forwarded requests to the real agent. This causes the input
3892 * side of the agent forwarding not to be emptied, exerting the
3893 * required back-pressure on the remote client, and encouraging it
3894 * to read our responses before sending too many more requests.
3896 if (c->ssh->throttled_all ||
3897 (c->ssh->version == 2 && c->v.v2.remwindow == 0))
3902 * Try to extract a complete message from the input buffer.
3904 datalen = bufchain_size(&c->u.a.inbuffer);
3906 break; /* not even a length field available yet */
3908 bufchain_fetch(&c->u.a.inbuffer, msglen, 4);
3909 lengthfield = GET_32BIT(msglen);
3910 if (lengthfield > datalen - 4)
3911 break; /* a whole message is not yet available */
3913 messagelen = lengthfield + 4;
3915 message = snewn(messagelen, unsigned char);
3916 bufchain_fetch(&c->u.a.inbuffer, message, messagelen);
3917 bufchain_consume(&c->u.a.inbuffer, messagelen);
3918 c->u.a.pending = agent_query(
3919 message, messagelen, &reply, &replylen, ssh_agentf_callback, c);
3923 return; /* agent_query promised to reply in due course */
3926 * If the agent gave us an answer immediately, pass it
3927 * straight on and go round this loop again.
3929 ssh_agentf_got_response(c, reply, replylen);
3933 * If we get here (i.e. we left the above while loop via 'break'
3934 * rather than 'return'), that means we've determined that the
3935 * input buffer for the agent forwarding connection doesn't
3936 * contain a complete request.
3938 * So if there's potentially more data to come, we can return now,
3939 * and wait for the remote client to send it. But if the remote
3940 * has sent EOF, it would be a mistake to do that, because we'd be
3941 * waiting a long time. So this is the moment to check for EOF,
3942 * and respond appropriately.
3944 if (c->closes & CLOSES_RCVD_EOF)
3945 sshfwd_write_eof(c);
3948 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3950 struct ssh_channel *c = (struct ssh_channel *)cv;
3952 ssh_agentf_got_response(c, reply, replylen);
3956 * Now try to extract and send further messages from the channel's
3957 * input-side buffer.
3959 ssh_agentf_try_forward(c);
3963 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3964 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3965 * => log `wire_reason'.
3967 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3968 const char *wire_reason,
3969 int code, int clean_exit)
3973 client_reason = wire_reason;
3975 error = dupprintf("Disconnected: %s", client_reason);
3977 error = dupstr("Disconnected");
3979 if (ssh->version == 1) {
3980 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3982 } else if (ssh->version == 2) {
3983 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3984 ssh2_pkt_adduint32(pktout, code);
3985 ssh2_pkt_addstring(pktout, wire_reason);
3986 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3987 ssh2_pkt_send_noqueue(ssh, pktout);
3990 ssh->close_expected = TRUE;
3991 ssh->clean_exit = clean_exit;
3992 ssh_closing((Plug)ssh, error, 0, 0);
3996 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3997 const struct ssh_signkey *ssh2keytype,
4000 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
4001 return -1; /* no manual keys configured */
4006 * The fingerprint string we've been given will have things
4007 * like 'ssh-rsa 2048' at the front of it. Strip those off and
4008 * narrow down to just the colon-separated hex block at the
4009 * end of the string.
4011 const char *p = strrchr(fingerprint, ' ');
4012 fingerprint = p ? p+1 : fingerprint;
4013 /* Quick sanity checks, including making sure it's in lowercase */
4014 assert(strlen(fingerprint) == 16*3 - 1);
4015 assert(fingerprint[2] == ':');
4016 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
4018 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
4020 return 1; /* success */
4025 * Construct the base64-encoded public key blob and see if
4028 unsigned char *binblob;
4030 int binlen, atoms, i;
4031 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
4032 atoms = (binlen + 2) / 3;
4033 base64blob = snewn(atoms * 4 + 1, char);
4034 for (i = 0; i < atoms; i++)
4035 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
4036 base64blob[atoms * 4] = '\0';
4038 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
4041 return 1; /* success */
4050 * Handle the key exchange and user authentication phases.
4052 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
4053 struct Packet *pktin)
4056 unsigned char cookie[8], *ptr;
4057 struct MD5Context md5c;
4058 struct do_ssh1_login_state {
4061 unsigned char *rsabuf;
4062 const unsigned char *keystr1, *keystr2;
4063 unsigned long supported_ciphers_mask, supported_auths_mask;
4064 int tried_publickey, tried_agent;
4065 int tis_auth_refused, ccard_auth_refused;
4066 unsigned char session_id[16];
4068 void *publickey_blob;
4069 int publickey_bloblen;
4070 char *publickey_comment;
4071 int privatekey_available, privatekey_encrypted;
4072 prompts_t *cur_prompt;
4075 unsigned char request[5], *response, *p;
4085 struct RSAKey servkey, hostkey;
4087 crState(do_ssh1_login_state);
4094 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
4095 bombout(("Public key packet not received"));
4099 logevent("Received public keys");
4101 ptr = ssh_pkt_getdata(pktin, 8);
4103 bombout(("SSH-1 public key packet stopped before random cookie"));
4106 memcpy(cookie, ptr, 8);
4108 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
4109 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
4110 bombout(("Failed to read SSH-1 public keys from public key packet"));
4115 * Log the host key fingerprint.
4119 logevent("Host key fingerprint is:");
4120 strcpy(logmsg, " ");
4121 s->hostkey.comment = NULL;
4122 rsa_fingerprint(logmsg + strlen(logmsg),
4123 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4127 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4128 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4129 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4130 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4131 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4133 ssh->v1_local_protoflags =
4134 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4135 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4138 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4139 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4140 MD5Update(&md5c, cookie, 8);
4141 MD5Final(s->session_id, &md5c);
4143 for (i = 0; i < 32; i++)
4144 ssh->session_key[i] = random_byte();
4147 * Verify that the `bits' and `bytes' parameters match.
4149 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4150 s->servkey.bits > s->servkey.bytes * 8) {
4151 bombout(("SSH-1 public keys were badly formatted"));
4155 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4156 s->hostkey.bytes : s->servkey.bytes);
4158 s->rsabuf = snewn(s->len, unsigned char);
4161 * Verify the host key.
4165 * First format the key into a string.
4167 int len = rsastr_len(&s->hostkey);
4168 char fingerprint[100];
4169 char *keystr = snewn(len, char);
4170 rsastr_fmt(keystr, &s->hostkey);
4171 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4173 /* First check against manually configured host keys. */
4174 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4175 if (s->dlgret == 0) { /* did not match */
4176 bombout(("Host key did not appear in manually configured list"));
4179 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4180 ssh_set_frozen(ssh, 1);
4181 s->dlgret = verify_ssh_host_key(ssh->frontend,
4182 ssh->savedhost, ssh->savedport,
4183 "rsa", keystr, fingerprint,
4184 ssh_dialog_callback, ssh);
4189 if (s->dlgret < 0) {
4193 bombout(("Unexpected data from server while waiting"
4194 " for user host key response"));
4197 } while (pktin || inlen > 0);
4198 s->dlgret = ssh->user_response;
4200 ssh_set_frozen(ssh, 0);
4202 if (s->dlgret == 0) {
4203 ssh_disconnect(ssh, "User aborted at host key verification",
4212 for (i = 0; i < 32; i++) {
4213 s->rsabuf[i] = ssh->session_key[i];
4215 s->rsabuf[i] ^= s->session_id[i];
4218 if (s->hostkey.bytes > s->servkey.bytes) {
4219 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4221 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4223 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4225 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4228 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4232 logevent("Encrypted session key");
4235 int cipher_chosen = 0, warn = 0;
4236 const char *cipher_string = NULL;
4238 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4239 int next_cipher = conf_get_int_int(ssh->conf,
4240 CONF_ssh_cipherlist, i);
4241 if (next_cipher == CIPHER_WARN) {
4242 /* If/when we choose a cipher, warn about it */
4244 } else if (next_cipher == CIPHER_AES) {
4245 /* XXX Probably don't need to mention this. */
4246 logevent("AES not supported in SSH-1, skipping");
4248 switch (next_cipher) {
4249 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4250 cipher_string = "3DES"; break;
4251 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4252 cipher_string = "Blowfish"; break;
4253 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4254 cipher_string = "single-DES"; break;
4256 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4260 if (!cipher_chosen) {
4261 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4262 bombout(("Server violates SSH-1 protocol by not "
4263 "supporting 3DES encryption"));
4265 /* shouldn't happen */
4266 bombout(("No supported ciphers found"));
4270 /* Warn about chosen cipher if necessary. */
4272 ssh_set_frozen(ssh, 1);
4273 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4274 ssh_dialog_callback, ssh);
4275 if (s->dlgret < 0) {
4279 bombout(("Unexpected data from server while waiting"
4280 " for user response"));
4283 } while (pktin || inlen > 0);
4284 s->dlgret = ssh->user_response;
4286 ssh_set_frozen(ssh, 0);
4287 if (s->dlgret == 0) {
4288 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4295 switch (s->cipher_type) {
4296 case SSH_CIPHER_3DES:
4297 logevent("Using 3DES encryption");
4299 case SSH_CIPHER_DES:
4300 logevent("Using single-DES encryption");
4302 case SSH_CIPHER_BLOWFISH:
4303 logevent("Using Blowfish encryption");
4307 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4308 PKT_CHAR, s->cipher_type,
4309 PKT_DATA, cookie, 8,
4310 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4311 PKT_DATA, s->rsabuf, s->len,
4312 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4314 logevent("Trying to enable encryption...");
4318 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4319 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4321 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4322 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4323 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4325 ssh->crcda_ctx = crcda_make_context();
4326 logevent("Installing CRC compensation attack detector");
4328 if (s->servkey.modulus) {
4329 sfree(s->servkey.modulus);
4330 s->servkey.modulus = NULL;
4332 if (s->servkey.exponent) {
4333 sfree(s->servkey.exponent);
4334 s->servkey.exponent = NULL;
4336 if (s->hostkey.modulus) {
4337 sfree(s->hostkey.modulus);
4338 s->hostkey.modulus = NULL;
4340 if (s->hostkey.exponent) {
4341 sfree(s->hostkey.exponent);
4342 s->hostkey.exponent = NULL;
4346 if (pktin->type != SSH1_SMSG_SUCCESS) {
4347 bombout(("Encryption not successfully enabled"));
4351 logevent("Successfully started encryption");
4353 fflush(stdout); /* FIXME eh? */
4355 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4356 int ret; /* need not be kept over crReturn */
4357 s->cur_prompt = new_prompts(ssh->frontend);
4358 s->cur_prompt->to_server = TRUE;
4359 s->cur_prompt->name = dupstr("SSH login name");
4360 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4361 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4364 crWaitUntil(!pktin);
4365 ret = get_userpass_input(s->cur_prompt, in, inlen);
4370 * Failed to get a username. Terminate.
4372 free_prompts(s->cur_prompt);
4373 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4376 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4377 free_prompts(s->cur_prompt);
4380 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4382 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4384 if (flags & FLAG_INTERACTIVE &&
4385 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4386 c_write_str(ssh, userlog);
4387 c_write_str(ssh, "\r\n");
4395 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4396 /* We must not attempt PK auth. Pretend we've already tried it. */
4397 s->tried_publickey = s->tried_agent = 1;
4399 s->tried_publickey = s->tried_agent = 0;
4401 s->tis_auth_refused = s->ccard_auth_refused = 0;
4403 * Load the public half of any configured keyfile for later use.
4405 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4406 if (!filename_is_null(s->keyfile)) {
4408 logeventf(ssh, "Reading key file \"%.150s\"",
4409 filename_to_str(s->keyfile));
4410 keytype = key_type(s->keyfile);
4411 if (keytype == SSH_KEYTYPE_SSH1 ||
4412 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4414 if (rsakey_pubblob(s->keyfile,
4415 &s->publickey_blob, &s->publickey_bloblen,
4416 &s->publickey_comment, &error)) {
4417 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4418 if (!s->privatekey_available)
4419 logeventf(ssh, "Key file contains public key only");
4420 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4424 logeventf(ssh, "Unable to load key (%s)", error);
4425 msgbuf = dupprintf("Unable to load key file "
4426 "\"%.150s\" (%s)\r\n",
4427 filename_to_str(s->keyfile),
4429 c_write_str(ssh, msgbuf);
4431 s->publickey_blob = NULL;
4435 logeventf(ssh, "Unable to use this key file (%s)",
4436 key_type_to_str(keytype));
4437 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4439 filename_to_str(s->keyfile),
4440 key_type_to_str(keytype));
4441 c_write_str(ssh, msgbuf);
4443 s->publickey_blob = NULL;
4446 s->publickey_blob = NULL;
4448 while (pktin->type == SSH1_SMSG_FAILURE) {
4449 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4451 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4453 * Attempt RSA authentication using Pageant.
4459 logevent("Pageant is running. Requesting keys.");
4461 /* Request the keys held by the agent. */
4462 PUT_32BIT(s->request, 1);
4463 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4464 ssh->auth_agent_query = agent_query(
4465 s->request, 5, &r, &s->responselen, ssh_agent_callback, ssh);
4466 if (ssh->auth_agent_query) {
4470 bombout(("Unexpected data from server while waiting"
4471 " for agent response"));
4474 } while (pktin || inlen > 0);
4475 r = ssh->agent_response;
4476 s->responselen = ssh->agent_response_len;
4478 s->response = (unsigned char *) r;
4479 if (s->response && s->responselen >= 5 &&
4480 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4481 s->p = s->response + 5;
4482 s->nkeys = toint(GET_32BIT(s->p));
4484 logeventf(ssh, "Pageant reported negative key count %d",
4489 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4490 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4491 unsigned char *pkblob = s->p;
4495 do { /* do while (0) to make breaking easy */
4496 n = ssh1_read_bignum
4497 (s->p, toint(s->responselen-(s->p-s->response)),
4502 n = ssh1_read_bignum
4503 (s->p, toint(s->responselen-(s->p-s->response)),
4508 if (s->responselen - (s->p-s->response) < 4)
4510 s->commentlen = toint(GET_32BIT(s->p));
4512 if (s->commentlen < 0 ||
4513 toint(s->responselen - (s->p-s->response)) <
4516 s->commentp = (char *)s->p;
4517 s->p += s->commentlen;
4521 logevent("Pageant key list packet was truncated");
4525 if (s->publickey_blob) {
4526 if (!memcmp(pkblob, s->publickey_blob,
4527 s->publickey_bloblen)) {
4528 logeventf(ssh, "Pageant key #%d matches "
4529 "configured key file", s->keyi);
4530 s->tried_publickey = 1;
4532 /* Skip non-configured key */
4535 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4536 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4537 PKT_BIGNUM, s->key.modulus, PKT_END);
4539 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4540 logevent("Key refused");
4543 logevent("Received RSA challenge");
4544 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4545 bombout(("Server's RSA challenge was badly formatted"));
4550 char *agentreq, *q, *ret;
4553 len = 1 + 4; /* message type, bit count */
4554 len += ssh1_bignum_length(s->key.exponent);
4555 len += ssh1_bignum_length(s->key.modulus);
4556 len += ssh1_bignum_length(s->challenge);
4557 len += 16; /* session id */
4558 len += 4; /* response format */
4559 agentreq = snewn(4 + len, char);
4560 PUT_32BIT(agentreq, len);
4562 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4563 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4565 q += ssh1_write_bignum(q, s->key.exponent);
4566 q += ssh1_write_bignum(q, s->key.modulus);
4567 q += ssh1_write_bignum(q, s->challenge);
4568 memcpy(q, s->session_id, 16);
4570 PUT_32BIT(q, 1); /* response format */
4571 ssh->auth_agent_query = agent_query(
4572 agentreq, len + 4, &vret, &retlen,
4573 ssh_agent_callback, ssh);
4574 if (ssh->auth_agent_query) {
4579 bombout(("Unexpected data from server"
4580 " while waiting for agent"
4584 } while (pktin || inlen > 0);
4585 vret = ssh->agent_response;
4586 retlen = ssh->agent_response_len;
4591 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4592 logevent("Sending Pageant's response");
4593 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4594 PKT_DATA, ret + 5, 16,
4598 if (pktin->type == SSH1_SMSG_SUCCESS) {
4600 ("Pageant's response accepted");
4601 if (flags & FLAG_VERBOSE) {
4602 c_write_str(ssh, "Authenticated using"
4604 c_write(ssh, s->commentp,
4606 c_write_str(ssh, "\" from agent\r\n");
4611 ("Pageant's response not accepted");
4614 ("Pageant failed to answer challenge");
4618 logevent("No reply received from Pageant");
4621 freebn(s->key.exponent);
4622 freebn(s->key.modulus);
4623 freebn(s->challenge);
4628 if (s->publickey_blob && !s->tried_publickey)
4629 logevent("Configured key file not in Pageant");
4631 logevent("Failed to get reply from Pageant");
4636 if (s->publickey_blob && s->privatekey_available &&
4637 !s->tried_publickey) {
4639 * Try public key authentication with the specified
4642 int got_passphrase; /* need not be kept over crReturn */
4643 if (flags & FLAG_VERBOSE)
4644 c_write_str(ssh, "Trying public key authentication.\r\n");
4645 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4646 logeventf(ssh, "Trying public key \"%s\"",
4647 filename_to_str(s->keyfile));
4648 s->tried_publickey = 1;
4649 got_passphrase = FALSE;
4650 while (!got_passphrase) {
4652 * Get a passphrase, if necessary.
4654 char *passphrase = NULL; /* only written after crReturn */
4656 if (!s->privatekey_encrypted) {
4657 if (flags & FLAG_VERBOSE)
4658 c_write_str(ssh, "No passphrase required.\r\n");
4661 int ret; /* need not be kept over crReturn */
4662 s->cur_prompt = new_prompts(ssh->frontend);
4663 s->cur_prompt->to_server = FALSE;
4664 s->cur_prompt->name = dupstr("SSH key passphrase");
4665 add_prompt(s->cur_prompt,
4666 dupprintf("Passphrase for key \"%.100s\": ",
4667 s->publickey_comment), FALSE);
4668 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4671 crWaitUntil(!pktin);
4672 ret = get_userpass_input(s->cur_prompt, in, inlen);
4676 /* Failed to get a passphrase. Terminate. */
4677 free_prompts(s->cur_prompt);
4678 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4682 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4683 free_prompts(s->cur_prompt);
4686 * Try decrypting key with passphrase.
4688 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4689 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4692 smemclr(passphrase, strlen(passphrase));
4696 /* Correct passphrase. */
4697 got_passphrase = TRUE;
4698 } else if (ret == 0) {
4699 c_write_str(ssh, "Couldn't load private key from ");
4700 c_write_str(ssh, filename_to_str(s->keyfile));
4701 c_write_str(ssh, " (");
4702 c_write_str(ssh, error);
4703 c_write_str(ssh, ").\r\n");
4704 got_passphrase = FALSE;
4705 break; /* go and try something else */
4706 } else if (ret == -1) {
4707 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4708 got_passphrase = FALSE;
4711 assert(0 && "unexpected return from loadrsakey()");
4712 got_passphrase = FALSE; /* placate optimisers */
4716 if (got_passphrase) {
4719 * Send a public key attempt.
4721 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4722 PKT_BIGNUM, s->key.modulus, PKT_END);
4725 if (pktin->type == SSH1_SMSG_FAILURE) {
4726 c_write_str(ssh, "Server refused our public key.\r\n");
4727 continue; /* go and try something else */
4729 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4730 bombout(("Bizarre response to offer of public key"));
4736 unsigned char buffer[32];
4737 Bignum challenge, response;
4739 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4740 bombout(("Server's RSA challenge was badly formatted"));
4743 response = rsadecrypt(challenge, &s->key);
4744 freebn(s->key.private_exponent);/* burn the evidence */
4746 for (i = 0; i < 32; i++) {
4747 buffer[i] = bignum_byte(response, 31 - i);
4751 MD5Update(&md5c, buffer, 32);
4752 MD5Update(&md5c, s->session_id, 16);
4753 MD5Final(buffer, &md5c);
4755 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4756 PKT_DATA, buffer, 16, PKT_END);
4763 if (pktin->type == SSH1_SMSG_FAILURE) {
4764 if (flags & FLAG_VERBOSE)
4765 c_write_str(ssh, "Failed to authenticate with"
4766 " our public key.\r\n");
4767 continue; /* go and try something else */
4768 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4769 bombout(("Bizarre response to RSA authentication response"));
4773 break; /* we're through! */
4779 * Otherwise, try various forms of password-like authentication.
4781 s->cur_prompt = new_prompts(ssh->frontend);
4783 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4784 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4785 !s->tis_auth_refused) {
4786 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4787 logevent("Requested TIS authentication");
4788 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4790 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4791 logevent("TIS authentication declined");
4792 if (flags & FLAG_INTERACTIVE)
4793 c_write_str(ssh, "TIS authentication refused.\r\n");
4794 s->tis_auth_refused = 1;
4799 char *instr_suf, *prompt;
4801 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4803 bombout(("TIS challenge packet was badly formed"));
4806 logevent("Received TIS challenge");
4807 s->cur_prompt->to_server = TRUE;
4808 s->cur_prompt->name = dupstr("SSH TIS authentication");
4809 /* Prompt heuristic comes from OpenSSH */
4810 if (memchr(challenge, '\n', challengelen)) {
4811 instr_suf = dupstr("");
4812 prompt = dupprintf("%.*s", challengelen, challenge);
4814 instr_suf = dupprintf("%.*s", challengelen, challenge);
4815 prompt = dupstr("Response: ");
4817 s->cur_prompt->instruction =
4818 dupprintf("Using TIS authentication.%s%s",
4819 (*instr_suf) ? "\n" : "",
4821 s->cur_prompt->instr_reqd = TRUE;
4822 add_prompt(s->cur_prompt, prompt, FALSE);
4826 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4827 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4828 !s->ccard_auth_refused) {
4829 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4830 logevent("Requested CryptoCard authentication");
4831 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4833 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4834 logevent("CryptoCard authentication declined");
4835 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4836 s->ccard_auth_refused = 1;
4841 char *instr_suf, *prompt;
4843 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4845 bombout(("CryptoCard challenge packet was badly formed"));
4848 logevent("Received CryptoCard challenge");
4849 s->cur_prompt->to_server = TRUE;
4850 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4851 s->cur_prompt->name_reqd = FALSE;
4852 /* Prompt heuristic comes from OpenSSH */
4853 if (memchr(challenge, '\n', challengelen)) {
4854 instr_suf = dupstr("");
4855 prompt = dupprintf("%.*s", challengelen, challenge);
4857 instr_suf = dupprintf("%.*s", challengelen, challenge);
4858 prompt = dupstr("Response: ");
4860 s->cur_prompt->instruction =
4861 dupprintf("Using CryptoCard authentication.%s%s",
4862 (*instr_suf) ? "\n" : "",
4864 s->cur_prompt->instr_reqd = TRUE;
4865 add_prompt(s->cur_prompt, prompt, FALSE);
4869 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4870 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4871 bombout(("No supported authentication methods available"));
4874 s->cur_prompt->to_server = TRUE;
4875 s->cur_prompt->name = dupstr("SSH password");
4876 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4877 ssh->username, ssh->savedhost),
4882 * Show password prompt, having first obtained it via a TIS
4883 * or CryptoCard exchange if we're doing TIS or CryptoCard
4887 int ret; /* need not be kept over crReturn */
4888 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4891 crWaitUntil(!pktin);
4892 ret = get_userpass_input(s->cur_prompt, in, inlen);
4897 * Failed to get a password (for example
4898 * because one was supplied on the command line
4899 * which has already failed to work). Terminate.
4901 free_prompts(s->cur_prompt);
4902 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4907 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4909 * Defence against traffic analysis: we send a
4910 * whole bunch of packets containing strings of
4911 * different lengths. One of these strings is the
4912 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4913 * The others are all random data in
4914 * SSH1_MSG_IGNORE packets. This way a passive
4915 * listener can't tell which is the password, and
4916 * hence can't deduce the password length.
4918 * Anybody with a password length greater than 16
4919 * bytes is going to have enough entropy in their
4920 * password that a listener won't find it _that_
4921 * much help to know how long it is. So what we'll
4924 * - if password length < 16, we send 15 packets
4925 * containing string lengths 1 through 15
4927 * - otherwise, we let N be the nearest multiple
4928 * of 8 below the password length, and send 8
4929 * packets containing string lengths N through
4930 * N+7. This won't obscure the order of
4931 * magnitude of the password length, but it will
4932 * introduce a bit of extra uncertainty.
4934 * A few servers can't deal with SSH1_MSG_IGNORE, at
4935 * least in this context. For these servers, we need
4936 * an alternative defence. We make use of the fact
4937 * that the password is interpreted as a C string:
4938 * so we can append a NUL, then some random data.
4940 * A few servers can deal with neither SSH1_MSG_IGNORE
4941 * here _nor_ a padded password string.
4942 * For these servers we are left with no defences
4943 * against password length sniffing.
4945 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4946 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4948 * The server can deal with SSH1_MSG_IGNORE, so
4949 * we can use the primary defence.
4951 int bottom, top, pwlen, i;
4954 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4956 bottom = 0; /* zero length passwords are OK! :-) */
4959 bottom = pwlen & ~7;
4963 assert(pwlen >= bottom && pwlen <= top);
4965 randomstr = snewn(top + 1, char);
4967 for (i = bottom; i <= top; i++) {
4969 defer_packet(ssh, s->pwpkt_type,
4970 PKT_STR,s->cur_prompt->prompts[0]->result,
4973 for (j = 0; j < i; j++) {
4975 randomstr[j] = random_byte();
4976 } while (randomstr[j] == '\0');
4978 randomstr[i] = '\0';
4979 defer_packet(ssh, SSH1_MSG_IGNORE,
4980 PKT_STR, randomstr, PKT_END);
4983 logevent("Sending password with camouflage packets");
4984 ssh_pkt_defersend(ssh);
4987 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4989 * The server can't deal with SSH1_MSG_IGNORE
4990 * but can deal with padded passwords, so we
4991 * can use the secondary defence.
4997 len = strlen(s->cur_prompt->prompts[0]->result);
4998 if (len < sizeof(string)) {
5000 strcpy(string, s->cur_prompt->prompts[0]->result);
5001 len++; /* cover the zero byte */
5002 while (len < sizeof(string)) {
5003 string[len++] = (char) random_byte();
5006 ss = s->cur_prompt->prompts[0]->result;
5008 logevent("Sending length-padded password");
5009 send_packet(ssh, s->pwpkt_type,
5010 PKT_INT, len, PKT_DATA, ss, len,
5014 * The server is believed unable to cope with
5015 * any of our password camouflage methods.
5018 len = strlen(s->cur_prompt->prompts[0]->result);
5019 logevent("Sending unpadded password");
5020 send_packet(ssh, s->pwpkt_type,
5022 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
5026 send_packet(ssh, s->pwpkt_type,
5027 PKT_STR, s->cur_prompt->prompts[0]->result,
5030 logevent("Sent password");
5031 free_prompts(s->cur_prompt);
5033 if (pktin->type == SSH1_SMSG_FAILURE) {
5034 if (flags & FLAG_VERBOSE)
5035 c_write_str(ssh, "Access denied\r\n");
5036 logevent("Authentication refused");
5037 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
5038 bombout(("Strange packet received, type %d", pktin->type));
5044 if (s->publickey_blob) {
5045 sfree(s->publickey_blob);
5046 sfree(s->publickey_comment);
5049 logevent("Authentication successful");
5054 static void ssh_channel_try_eof(struct ssh_channel *c)
5057 assert(c->pending_eof); /* precondition for calling us */
5059 return; /* can't close: not even opened yet */
5060 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
5061 return; /* can't send EOF: pending outgoing data */
5063 c->pending_eof = FALSE; /* we're about to send it */
5064 if (ssh->version == 1) {
5065 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5067 c->closes |= CLOSES_SENT_EOF;
5069 struct Packet *pktout;
5070 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5071 ssh2_pkt_adduint32(pktout, c->remoteid);
5072 ssh2_pkt_send(ssh, pktout);
5073 c->closes |= CLOSES_SENT_EOF;
5074 ssh2_channel_check_close(c);
5078 Conf *sshfwd_get_conf(struct ssh_channel *c)
5084 void sshfwd_write_eof(struct ssh_channel *c)
5088 if (ssh->state == SSH_STATE_CLOSED)
5091 if (c->closes & CLOSES_SENT_EOF)
5094 c->pending_eof = TRUE;
5095 ssh_channel_try_eof(c);
5098 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
5103 if (ssh->state == SSH_STATE_CLOSED)
5106 reason = dupprintf("due to local error: %s", err);
5107 ssh_channel_close_local(c, reason);
5109 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5111 ssh2_channel_check_close(c);
5114 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5118 if (ssh->state == SSH_STATE_CLOSED)
5121 return ssh_send_channel_data(c, buf, len);
5124 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5128 if (ssh->state == SSH_STATE_CLOSED)
5131 ssh_channel_unthrottle(c, bufsize);
5134 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5136 struct queued_handler *qh = ssh->qhead;
5140 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5143 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5144 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5147 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5148 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5152 ssh->qhead = qh->next;
5154 if (ssh->qhead->msg1 > 0) {
5155 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5156 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5158 if (ssh->qhead->msg2 > 0) {
5159 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5160 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5163 ssh->qhead = ssh->qtail = NULL;
5166 qh->handler(ssh, pktin, qh->ctx);
5171 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5172 chandler_fn_t handler, void *ctx)
5174 struct queued_handler *qh;
5176 qh = snew(struct queued_handler);
5179 qh->handler = handler;
5183 if (ssh->qtail == NULL) {
5187 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5188 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5191 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5192 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5195 ssh->qtail->next = qh;
5200 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5202 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5204 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5205 SSH2_MSG_REQUEST_SUCCESS)) {
5206 logeventf(ssh, "Remote port forwarding from %s enabled",
5209 logeventf(ssh, "Remote port forwarding from %s refused",
5212 rpf = del234(ssh->rportfwds, pf);
5214 pf->pfrec->remote = NULL;
5219 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5222 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5225 pf->share_ctx = share_ctx;
5226 pf->shost = dupstr(shost);
5228 pf->sportdesc = NULL;
5229 if (!ssh->rportfwds) {
5230 assert(ssh->version == 2);
5231 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5233 if (add234(ssh->rportfwds, pf) != pf) {
5241 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5244 share_got_pkt_from_server(ctx, pktin->type,
5245 pktin->body, pktin->length);
5248 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5250 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5251 ssh_sharing_global_request_response, share_ctx);
5254 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5256 struct ssh_portfwd *epf;
5260 if (!ssh->portfwds) {
5261 ssh->portfwds = newtree234(ssh_portcmp);
5264 * Go through the existing port forwardings and tag them
5265 * with status==DESTROY. Any that we want to keep will be
5266 * re-enabled (status==KEEP) as we go through the
5267 * configuration and find out which bits are the same as
5270 struct ssh_portfwd *epf;
5272 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5273 epf->status = DESTROY;
5276 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5278 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5279 char *kp, *kp2, *vp, *vp2;
5280 char address_family, type;
5281 int sport,dport,sserv,dserv;
5282 char *sports, *dports, *saddr, *host;
5286 address_family = 'A';
5288 if (*kp == 'A' || *kp == '4' || *kp == '6')
5289 address_family = *kp++;
5290 if (*kp == 'L' || *kp == 'R')
5293 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5295 * There's a colon in the middle of the source port
5296 * string, which means that the part before it is
5297 * actually a source address.
5299 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5300 saddr = host_strduptrim(saddr_tmp);
5307 sport = atoi(sports);
5311 sport = net_service_lookup(sports);
5313 logeventf(ssh, "Service lookup failed for source"
5314 " port \"%s\"", sports);
5318 if (type == 'L' && !strcmp(val, "D")) {
5319 /* dynamic forwarding */
5326 /* ordinary forwarding */
5328 vp2 = vp + host_strcspn(vp, ":");
5329 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5333 dport = atoi(dports);
5337 dport = net_service_lookup(dports);
5339 logeventf(ssh, "Service lookup failed for destination"
5340 " port \"%s\"", dports);
5345 if (sport && dport) {
5346 /* Set up a description of the source port. */
5347 struct ssh_portfwd *pfrec, *epfrec;
5349 pfrec = snew(struct ssh_portfwd);
5351 pfrec->saddr = saddr;
5352 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5353 pfrec->sport = sport;
5354 pfrec->daddr = host;
5355 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5356 pfrec->dport = dport;
5357 pfrec->local = NULL;
5358 pfrec->remote = NULL;
5359 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5360 address_family == '6' ? ADDRTYPE_IPV6 :
5363 epfrec = add234(ssh->portfwds, pfrec);
5364 if (epfrec != pfrec) {
5365 if (epfrec->status == DESTROY) {
5367 * We already have a port forwarding up and running
5368 * with precisely these parameters. Hence, no need
5369 * to do anything; simply re-tag the existing one
5372 epfrec->status = KEEP;
5375 * Anything else indicates that there was a duplicate
5376 * in our input, which we'll silently ignore.
5378 free_portfwd(pfrec);
5380 pfrec->status = CREATE;
5389 * Now go through and destroy any port forwardings which were
5392 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5393 if (epf->status == DESTROY) {
5396 message = dupprintf("%s port forwarding from %s%s%d",
5397 epf->type == 'L' ? "local" :
5398 epf->type == 'R' ? "remote" : "dynamic",
5399 epf->saddr ? epf->saddr : "",
5400 epf->saddr ? ":" : "",
5403 if (epf->type != 'D') {
5404 char *msg2 = dupprintf("%s to %s:%d", message,
5405 epf->daddr, epf->dport);
5410 logeventf(ssh, "Cancelling %s", message);
5413 /* epf->remote or epf->local may be NULL if setting up a
5414 * forwarding failed. */
5416 struct ssh_rportfwd *rpf = epf->remote;
5417 struct Packet *pktout;
5420 * Cancel the port forwarding at the server
5423 if (ssh->version == 1) {
5425 * We cannot cancel listening ports on the
5426 * server side in SSH-1! There's no message
5427 * to support it. Instead, we simply remove
5428 * the rportfwd record from the local end
5429 * so that any connections the server tries
5430 * to make on it are rejected.
5433 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5434 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5435 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5437 ssh2_pkt_addstring(pktout, epf->saddr);
5438 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5439 /* XXX: rport_acceptall may not represent
5440 * what was used to open the original connection,
5441 * since it's reconfigurable. */
5442 ssh2_pkt_addstring(pktout, "");
5444 ssh2_pkt_addstring(pktout, "localhost");
5446 ssh2_pkt_adduint32(pktout, epf->sport);
5447 ssh2_pkt_send(ssh, pktout);
5450 del234(ssh->rportfwds, rpf);
5452 } else if (epf->local) {
5453 pfl_terminate(epf->local);
5456 delpos234(ssh->portfwds, i);
5458 i--; /* so we don't skip one in the list */
5462 * And finally, set up any new port forwardings (status==CREATE).
5464 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5465 if (epf->status == CREATE) {
5466 char *sportdesc, *dportdesc;
5467 sportdesc = dupprintf("%s%s%s%s%d%s",
5468 epf->saddr ? epf->saddr : "",
5469 epf->saddr ? ":" : "",
5470 epf->sserv ? epf->sserv : "",
5471 epf->sserv ? "(" : "",
5473 epf->sserv ? ")" : "");
5474 if (epf->type == 'D') {
5477 dportdesc = dupprintf("%s:%s%s%d%s",
5479 epf->dserv ? epf->dserv : "",
5480 epf->dserv ? "(" : "",
5482 epf->dserv ? ")" : "");
5485 if (epf->type == 'L') {
5486 char *err = pfl_listen(epf->daddr, epf->dport,
5487 epf->saddr, epf->sport,
5488 ssh, conf, &epf->local,
5489 epf->addressfamily);
5491 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5492 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5493 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5494 sportdesc, dportdesc,
5495 err ? " failed: " : "", err ? err : "");
5498 } else if (epf->type == 'D') {
5499 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5500 ssh, conf, &epf->local,
5501 epf->addressfamily);
5503 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5504 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5505 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5507 err ? " failed: " : "", err ? err : "");
5512 struct ssh_rportfwd *pf;
5515 * Ensure the remote port forwardings tree exists.
5517 if (!ssh->rportfwds) {
5518 if (ssh->version == 1)
5519 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5521 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5524 pf = snew(struct ssh_rportfwd);
5525 pf->share_ctx = NULL;
5526 pf->dhost = dupstr(epf->daddr);
5527 pf->dport = epf->dport;
5529 pf->shost = dupstr(epf->saddr);
5530 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5531 pf->shost = dupstr("");
5533 pf->shost = dupstr("localhost");
5535 pf->sport = epf->sport;
5536 if (add234(ssh->rportfwds, pf) != pf) {
5537 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5538 epf->daddr, epf->dport);
5541 logeventf(ssh, "Requesting remote port %s"
5542 " forward to %s", sportdesc, dportdesc);
5544 pf->sportdesc = sportdesc;
5549 if (ssh->version == 1) {
5550 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5551 PKT_INT, epf->sport,
5552 PKT_STR, epf->daddr,
5553 PKT_INT, epf->dport,
5555 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5557 ssh_rportfwd_succfail, pf);
5559 struct Packet *pktout;
5560 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5561 ssh2_pkt_addstring(pktout, "tcpip-forward");
5562 ssh2_pkt_addbool(pktout, 1);/* want reply */
5563 ssh2_pkt_addstring(pktout, pf->shost);
5564 ssh2_pkt_adduint32(pktout, pf->sport);
5565 ssh2_pkt_send(ssh, pktout);
5567 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5568 SSH2_MSG_REQUEST_FAILURE,
5569 ssh_rportfwd_succfail, pf);
5578 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5581 int stringlen, bufsize;
5583 ssh_pkt_getstring(pktin, &string, &stringlen);
5584 if (string == NULL) {
5585 bombout(("Incoming terminal data packet was badly formed"));
5589 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5591 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5592 ssh->v1_stdout_throttling = 1;
5593 ssh_throttle_conn(ssh, +1);
5597 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5599 /* Remote side is trying to open a channel to talk to our
5600 * X-Server. Give them back a local channel number. */
5601 struct ssh_channel *c;
5602 int remoteid = ssh_pkt_getuint32(pktin);
5604 logevent("Received X11 connect request");
5605 /* Refuse if X11 forwarding is disabled. */
5606 if (!ssh->X11_fwd_enabled) {
5607 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5608 PKT_INT, remoteid, PKT_END);
5609 logevent("Rejected X11 connect request");
5611 c = snew(struct ssh_channel);
5614 ssh_channel_init(c);
5615 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5616 c->remoteid = remoteid;
5617 c->halfopen = FALSE;
5618 c->type = CHAN_X11; /* identify channel type */
5619 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5620 PKT_INT, c->remoteid, PKT_INT,
5621 c->localid, PKT_END);
5622 logevent("Opened X11 forward channel");
5626 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5628 /* Remote side is trying to open a channel to talk to our
5629 * agent. Give them back a local channel number. */
5630 struct ssh_channel *c;
5631 int remoteid = ssh_pkt_getuint32(pktin);
5633 /* Refuse if agent forwarding is disabled. */
5634 if (!ssh->agentfwd_enabled) {
5635 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5636 PKT_INT, remoteid, PKT_END);
5638 c = snew(struct ssh_channel);
5640 ssh_channel_init(c);
5641 c->remoteid = remoteid;
5642 c->halfopen = FALSE;
5643 c->type = CHAN_AGENT; /* identify channel type */
5644 c->u.a.pending = NULL;
5645 bufchain_init(&c->u.a.inbuffer);
5646 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5647 PKT_INT, c->remoteid, PKT_INT, c->localid,
5652 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5654 /* Remote side is trying to open a channel to talk to a
5655 * forwarded port. Give them back a local channel number. */
5656 struct ssh_rportfwd pf, *pfp;
5662 remoteid = ssh_pkt_getuint32(pktin);
5663 ssh_pkt_getstring(pktin, &host, &hostsize);
5664 port = ssh_pkt_getuint32(pktin);
5666 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5668 pfp = find234(ssh->rportfwds, &pf, NULL);
5671 logeventf(ssh, "Rejected remote port open request for %s:%d",
5673 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5674 PKT_INT, remoteid, PKT_END);
5676 struct ssh_channel *c = snew(struct ssh_channel);
5679 logeventf(ssh, "Received remote port open request for %s:%d",
5681 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5682 c, ssh->conf, pfp->pfrec->addressfamily);
5684 logeventf(ssh, "Port open failed: %s", err);
5687 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5688 PKT_INT, remoteid, PKT_END);
5690 ssh_channel_init(c);
5691 c->remoteid = remoteid;
5692 c->halfopen = FALSE;
5693 c->type = CHAN_SOCKDATA; /* identify channel type */
5694 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5695 PKT_INT, c->remoteid, PKT_INT,
5696 c->localid, PKT_END);
5697 logevent("Forwarded port opened successfully");
5704 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5706 struct ssh_channel *c;
5708 c = ssh_channel_msg(ssh, pktin);
5709 if (c && c->type == CHAN_SOCKDATA) {
5710 c->remoteid = ssh_pkt_getuint32(pktin);
5711 c->halfopen = FALSE;
5712 c->throttling_conn = 0;
5713 pfd_confirm(c->u.pfd.pf);
5716 if (c && c->pending_eof) {
5718 * We have a pending close on this channel,
5719 * which we decided on before the server acked
5720 * the channel open. So now we know the
5721 * remoteid, we can close it again.
5723 ssh_channel_try_eof(c);
5727 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5729 struct ssh_channel *c;
5731 c = ssh_channel_msg(ssh, pktin);
5732 if (c && c->type == CHAN_SOCKDATA) {
5733 logevent("Forwarded connection refused by server");
5734 pfd_close(c->u.pfd.pf);
5735 del234(ssh->channels, c);
5740 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5742 /* Remote side closes a channel. */
5743 struct ssh_channel *c;
5745 c = ssh_channel_msg(ssh, pktin);
5748 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE) {
5750 * Received CHANNEL_CLOSE, which we translate into
5753 ssh_channel_got_eof(c);
5756 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5757 !(c->closes & CLOSES_RCVD_CLOSE)) {
5759 if (!(c->closes & CLOSES_SENT_EOF)) {
5760 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %u"
5761 " for which we never sent CHANNEL_CLOSE\n",
5765 c->closes |= CLOSES_RCVD_CLOSE;
5768 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5769 !(c->closes & CLOSES_SENT_CLOSE)) {
5770 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5771 PKT_INT, c->remoteid, PKT_END);
5772 c->closes |= CLOSES_SENT_CLOSE;
5775 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5776 ssh_channel_destroy(c);
5781 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5783 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5786 bufchain_add(&c->u.a.inbuffer, data, length);
5787 ssh_agentf_try_forward(c);
5790 * We exert back-pressure on an agent forwarding client if and
5791 * only if we're waiting for the response to an asynchronous agent
5792 * request. This prevents the client running out of window while
5793 * receiving the _first_ message, but means that if any message
5794 * takes time to process, the client will be discouraged from
5795 * sending an endless stream of further ones after it.
5797 return (c->u.a.pending ? bufchain_size(&c->u.a.inbuffer) : 0);
5800 static int ssh_channel_data(struct ssh_channel *c, int is_stderr,
5801 char *data, int length)
5804 case CHAN_MAINSESSION:
5805 return from_backend(c->ssh->frontend, is_stderr, data, length);
5807 return x11_send(c->u.x11.xconn, data, length);
5809 return pfd_send(c->u.pfd.pf, data, length);
5811 return ssh_agent_channel_data(c, data, length);
5816 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5818 /* Data sent down one of our channels. */
5821 struct ssh_channel *c;
5823 c = ssh_channel_msg(ssh, pktin);
5824 ssh_pkt_getstring(pktin, &p, &len);
5827 int bufsize = ssh_channel_data(c, FALSE, p, len);
5828 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5829 c->throttling_conn = 1;
5830 ssh_throttle_conn(ssh, +1);
5835 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5837 ssh->exitcode = ssh_pkt_getuint32(pktin);
5838 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5839 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5841 * In case `helpful' firewalls or proxies tack
5842 * extra human-readable text on the end of the
5843 * session which we might mistake for another
5844 * encrypted packet, we close the session once
5845 * we've sent EXIT_CONFIRMATION.
5847 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5850 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5851 static void ssh1_send_ttymode(void *data,
5852 const struct ssh_ttymode *mode, char *val)
5854 struct Packet *pktout = (struct Packet *)data;
5855 unsigned int arg = 0;
5857 switch (mode->type) {
5859 arg = ssh_tty_parse_specchar(val);
5862 arg = ssh_tty_parse_boolean(val);
5865 ssh2_pkt_addbyte(pktout, mode->opcode);
5866 ssh2_pkt_addbyte(pktout, arg);
5869 int ssh_agent_forwarding_permitted(Ssh ssh)
5871 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5874 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5875 struct Packet *pktin)
5877 crBegin(ssh->do_ssh1_connection_crstate);
5879 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5880 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5881 ssh1_smsg_stdout_stderr_data;
5883 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5884 ssh1_msg_channel_open_confirmation;
5885 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5886 ssh1_msg_channel_open_failure;
5887 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5888 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5889 ssh1_msg_channel_close;
5890 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5891 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5893 if (ssh_agent_forwarding_permitted(ssh)) {
5894 logevent("Requesting agent forwarding");
5895 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5899 if (pktin->type != SSH1_SMSG_SUCCESS
5900 && pktin->type != SSH1_SMSG_FAILURE) {
5901 bombout(("Protocol confusion"));
5903 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5904 logevent("Agent forwarding refused");
5906 logevent("Agent forwarding enabled");
5907 ssh->agentfwd_enabled = TRUE;
5908 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5912 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5914 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5916 if (!ssh->x11disp) {
5917 /* FIXME: return an error message from x11_setup_display */
5918 logevent("X11 forwarding not enabled: unable to"
5919 " initialise X display");
5921 ssh->x11auth = x11_invent_fake_auth
5922 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5923 ssh->x11auth->disp = ssh->x11disp;
5925 logevent("Requesting X11 forwarding");
5926 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5927 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5928 PKT_STR, ssh->x11auth->protoname,
5929 PKT_STR, ssh->x11auth->datastring,
5930 PKT_INT, ssh->x11disp->screennum,
5933 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5934 PKT_STR, ssh->x11auth->protoname,
5935 PKT_STR, ssh->x11auth->datastring,
5941 if (pktin->type != SSH1_SMSG_SUCCESS
5942 && pktin->type != SSH1_SMSG_FAILURE) {
5943 bombout(("Protocol confusion"));
5945 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5946 logevent("X11 forwarding refused");
5948 logevent("X11 forwarding enabled");
5949 ssh->X11_fwd_enabled = TRUE;
5950 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5955 ssh_setup_portfwd(ssh, ssh->conf);
5956 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5958 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5960 /* Unpick the terminal-speed string. */
5961 /* XXX perhaps we should allow no speeds to be sent. */
5962 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5963 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5964 /* Send the pty request. */
5965 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5966 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5967 ssh_pkt_adduint32(pkt, ssh->term_height);
5968 ssh_pkt_adduint32(pkt, ssh->term_width);
5969 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5970 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5971 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5972 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5973 ssh_pkt_adduint32(pkt, ssh->ispeed);
5974 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5975 ssh_pkt_adduint32(pkt, ssh->ospeed);
5976 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5978 ssh->state = SSH_STATE_INTERMED;
5982 if (pktin->type != SSH1_SMSG_SUCCESS
5983 && pktin->type != SSH1_SMSG_FAILURE) {
5984 bombout(("Protocol confusion"));
5986 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5987 c_write_str(ssh, "Server refused to allocate pty\r\n");
5988 ssh->editing = ssh->echoing = 1;
5990 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5991 ssh->ospeed, ssh->ispeed);
5992 ssh->got_pty = TRUE;
5995 ssh->editing = ssh->echoing = 1;
5998 if (conf_get_int(ssh->conf, CONF_compression)) {
5999 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
6003 if (pktin->type != SSH1_SMSG_SUCCESS
6004 && pktin->type != SSH1_SMSG_FAILURE) {
6005 bombout(("Protocol confusion"));
6007 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6008 c_write_str(ssh, "Server refused to compress\r\n");
6010 logevent("Started compression");
6011 ssh->v1_compressing = TRUE;
6012 ssh->cs_comp_ctx = zlib_compress_init();
6013 logevent("Initialised zlib (RFC1950) compression");
6014 ssh->sc_comp_ctx = zlib_decompress_init();
6015 logevent("Initialised zlib (RFC1950) decompression");
6019 * Start the shell or command.
6021 * Special case: if the first-choice command is an SSH-2
6022 * subsystem (hence not usable here) and the second choice
6023 * exists, we fall straight back to that.
6026 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
6028 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
6029 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
6030 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
6031 ssh->fallback_cmd = TRUE;
6034 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6036 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6037 logevent("Started session");
6040 ssh->state = SSH_STATE_SESSION;
6041 if (ssh->size_needed)
6042 ssh_size(ssh, ssh->term_width, ssh->term_height);
6043 if (ssh->eof_needed)
6044 ssh_special(ssh, TS_EOF);
6047 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6049 ssh->channels = newtree234(ssh_channelcmp);
6053 * By this point, most incoming packets are already being
6054 * handled by the dispatch table, and we need only pay
6055 * attention to the unusual ones.
6060 if (pktin->type == SSH1_SMSG_SUCCESS) {
6061 /* may be from EXEC_SHELL on some servers */
6062 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6063 /* may be from EXEC_SHELL on some servers
6064 * if no pty is available or in other odd cases. Ignore */
6066 bombout(("Strange packet received: type %d", pktin->type));
6071 int len = min(inlen, 512);
6072 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6073 PKT_INT, len, PKT_DATA, in, len,
6085 * Handle the top-level SSH-2 protocol.
6087 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6092 ssh_pkt_getstring(pktin, &msg, &msglen);
6093 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6096 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6098 /* log reason code in disconnect message */
6102 ssh_pkt_getstring(pktin, &msg, &msglen);
6103 bombout(("Server sent disconnect message:\n\"%.*s\"",
6104 msglen, NULLTOEMPTY(msg)));
6107 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6109 /* Do nothing, because we're ignoring it! Duhh. */
6112 static void ssh1_protocol_setup(Ssh ssh)
6117 * Most messages are handled by the coroutines.
6119 for (i = 0; i < 256; i++)
6120 ssh->packet_dispatch[i] = NULL;
6123 * These special message types we install handlers for.
6125 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6126 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6127 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6130 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6131 struct Packet *pktin)
6133 const unsigned char *in = (const unsigned char *)vin;
6134 if (ssh->state == SSH_STATE_CLOSED)
6137 if (pktin && ssh->packet_dispatch[pktin->type]) {
6138 ssh->packet_dispatch[pktin->type](ssh, pktin);
6142 if (!ssh->protocol_initial_phase_done) {
6143 if (do_ssh1_login(ssh, in, inlen, pktin))
6144 ssh->protocol_initial_phase_done = TRUE;
6149 do_ssh1_connection(ssh, in, inlen, pktin);
6153 * Utility routines for decoding comma-separated strings in KEXINIT.
6155 static int first_in_commasep_string(char const *needle, char const *haystack,
6159 if (!needle || !haystack) /* protect against null pointers */
6161 needlen = strlen(needle);
6163 if (haylen >= needlen && /* haystack is long enough */
6164 !memcmp(needle, haystack, needlen) && /* initial match */
6165 (haylen == needlen || haystack[needlen] == ',')
6166 /* either , or EOS follows */
6172 static int in_commasep_string(char const *needle, char const *haystack,
6177 if (!needle || !haystack) /* protect against null pointers */
6180 * Is it at the start of the string?
6182 if (first_in_commasep_string(needle, haystack, haylen))
6185 * If not, search for the next comma and resume after that.
6186 * If no comma found, terminate.
6188 p = memchr(haystack, ',', haylen);
6190 /* + 1 to skip over comma */
6191 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6195 * Add a value to the comma-separated string at the end of the packet.
6197 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6199 if (pkt->length - pkt->savedpos > 0)
6200 ssh_pkt_addstring_str(pkt, ",");
6201 ssh_pkt_addstring_str(pkt, data);
6206 * SSH-2 key derivation (RFC 4253 section 7.2).
6208 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6209 char chr, int keylen)
6211 const struct ssh_hash *h = ssh->kex->hash;
6219 /* Round up to the next multiple of hash length. */
6220 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6222 key = snewn(keylen_padded, unsigned char);
6224 /* First hlen bytes. */
6226 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6227 hash_mpint(h, s, K);
6228 h->bytes(s, H, h->hlen);
6229 h->bytes(s, &chr, 1);
6230 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6233 /* Subsequent blocks of hlen bytes. */
6234 if (keylen_padded > h->hlen) {
6238 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6239 hash_mpint(h, s, K);
6240 h->bytes(s, H, h->hlen);
6242 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6243 h->bytes(s, key + offset - h->hlen, h->hlen);
6245 h->final(s2, key + offset);
6251 /* Now clear any extra bytes of key material beyond the length
6252 * we're officially returning, because the caller won't know to
6254 if (keylen_padded > keylen)
6255 smemclr(key + keylen, keylen_padded - keylen);
6261 * Structure for constructing KEXINIT algorithm lists.
6263 #define MAXKEXLIST 16
6264 struct kexinit_algorithm {
6268 const struct ssh_kex *kex;
6272 const struct ssh_signkey *hostkey;
6276 const struct ssh2_cipher *cipher;
6280 const struct ssh_mac *mac;
6283 const struct ssh_compress *comp;
6288 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6289 * If the algorithm is already in the list, return a pointer to its
6290 * entry, otherwise return an entry from the end of the list.
6291 * This assumes that every time a particular name is passed in, it
6292 * comes from the same string constant. If this isn't true, this
6293 * function may need to be rewritten to use strcmp() instead.
6295 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6296 *list, const char *name)
6300 for (i = 0; i < MAXKEXLIST; i++)
6301 if (list[i].name == NULL || list[i].name == name) {
6302 list[i].name = name;
6305 assert(!"No space in KEXINIT list");
6310 * Handle the SSH-2 transport layer.
6312 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6313 struct Packet *pktin)
6315 const unsigned char *in = (const unsigned char *)vin;
6317 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6318 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6321 const char * kexlist_descr[NKEXLIST] = {
6322 "key exchange algorithm", "host key algorithm",
6323 "client-to-server cipher", "server-to-client cipher",
6324 "client-to-server MAC", "server-to-client MAC",
6325 "client-to-server compression method",
6326 "server-to-client compression method" };
6327 struct do_ssh2_transport_state {
6329 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6330 Bignum p, g, e, f, K;
6333 int kex_init_value, kex_reply_value;
6334 const struct ssh_mac *const *maclist;
6336 const struct ssh2_cipher *cscipher_tobe;
6337 const struct ssh2_cipher *sccipher_tobe;
6338 const struct ssh_mac *csmac_tobe;
6339 const struct ssh_mac *scmac_tobe;
6340 int csmac_etm_tobe, scmac_etm_tobe;
6341 const struct ssh_compress *cscomp_tobe;
6342 const struct ssh_compress *sccomp_tobe;
6343 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6344 int hostkeylen, siglen, rsakeylen;
6345 void *hkey; /* actual host key */
6346 void *rsakey; /* for RSA kex */
6347 void *eckey; /* for ECDH kex */
6348 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6349 int n_preferred_kex;
6350 const struct ssh_kexes *preferred_kex[KEX_MAX];
6352 int preferred_hk[HK_MAX];
6353 int n_preferred_ciphers;
6354 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6355 const struct ssh_compress *preferred_comp;
6356 int userauth_succeeded; /* for delayed compression */
6357 int pending_compression;
6358 int got_session_id, activated_authconn;
6359 struct Packet *pktout;
6363 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6365 crState(do_ssh2_transport_state);
6367 assert(!ssh->bare_connection);
6368 assert(ssh->version == 2);
6372 s->cscipher_tobe = s->sccipher_tobe = NULL;
6373 s->csmac_tobe = s->scmac_tobe = NULL;
6374 s->cscomp_tobe = s->sccomp_tobe = NULL;
6376 s->got_session_id = s->activated_authconn = FALSE;
6377 s->userauth_succeeded = FALSE;
6378 s->pending_compression = FALSE;
6381 * Be prepared to work around the buggy MAC problem.
6383 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6384 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6386 s->maclist = macs, s->nmacs = lenof(macs);
6389 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6392 struct kexinit_algorithm *alg;
6395 * Set up the preferred key exchange. (NULL => warn below here)
6397 s->n_preferred_kex = 0;
6398 for (i = 0; i < KEX_MAX; i++) {
6399 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6401 s->preferred_kex[s->n_preferred_kex++] =
6402 &ssh_diffiehellman_gex;
6405 s->preferred_kex[s->n_preferred_kex++] =
6406 &ssh_diffiehellman_group14;
6409 s->preferred_kex[s->n_preferred_kex++] =
6410 &ssh_diffiehellman_group1;
6413 s->preferred_kex[s->n_preferred_kex++] =
6417 s->preferred_kex[s->n_preferred_kex++] =
6421 /* Flag for later. Don't bother if it's the last in
6423 if (i < KEX_MAX - 1) {
6424 s->preferred_kex[s->n_preferred_kex++] = NULL;
6431 * Set up the preferred host key types. These are just the ids
6432 * in the enum in putty.h, so 'warn below here' is indicated
6435 s->n_preferred_hk = 0;
6436 for (i = 0; i < HK_MAX; i++) {
6437 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6438 /* As above, don't bother with HK_WARN if it's last in the
6440 if (id != HK_WARN || i < HK_MAX - 1)
6441 s->preferred_hk[s->n_preferred_hk++] = id;
6445 * Set up the preferred ciphers. (NULL => warn below here)
6447 s->n_preferred_ciphers = 0;
6448 for (i = 0; i < CIPHER_MAX; i++) {
6449 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6450 case CIPHER_BLOWFISH:
6451 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6454 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6455 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6459 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6462 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6464 case CIPHER_ARCFOUR:
6465 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6467 case CIPHER_CHACHA20:
6468 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6471 /* Flag for later. Don't bother if it's the last in
6473 if (i < CIPHER_MAX - 1) {
6474 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6481 * Set up preferred compression.
6483 if (conf_get_int(ssh->conf, CONF_compression))
6484 s->preferred_comp = &ssh_zlib;
6486 s->preferred_comp = &ssh_comp_none;
6489 * Enable queueing of outgoing auth- or connection-layer
6490 * packets while we are in the middle of a key exchange.
6492 ssh->queueing = TRUE;
6495 * Flag that KEX is in progress.
6497 ssh->kex_in_progress = TRUE;
6499 for (i = 0; i < NKEXLIST; i++)
6500 for (j = 0; j < MAXKEXLIST; j++)
6501 s->kexlists[i][j].name = NULL;
6502 /* List key exchange algorithms. */
6504 for (i = 0; i < s->n_preferred_kex; i++) {
6505 const struct ssh_kexes *k = s->preferred_kex[i];
6506 if (!k) warn = TRUE;
6507 else for (j = 0; j < k->nkexes; j++) {
6508 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6510 alg->u.kex.kex = k->list[j];
6511 alg->u.kex.warn = warn;
6514 /* List server host key algorithms. */
6515 if (!s->got_session_id) {
6517 * In the first key exchange, we list all the algorithms
6518 * we're prepared to cope with, but prefer those algorithms
6519 * for which we have a host key for this host.
6521 * If the host key algorithm is below the warning
6522 * threshold, we warn even if we did already have a key
6523 * for it, on the basis that if the user has just
6524 * reconfigured that host key type to be warned about,
6525 * they surely _do_ want to be alerted that a server
6526 * they're actually connecting to is using it.
6529 for (i = 0; i < s->n_preferred_hk; i++) {
6530 if (s->preferred_hk[i] == HK_WARN)
6532 for (j = 0; j < lenof(hostkey_algs); j++) {
6533 if (hostkey_algs[j].id != s->preferred_hk[i])
6535 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6536 hostkey_algs[j].alg->keytype)) {
6537 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6538 hostkey_algs[j].alg->name);
6539 alg->u.hk.hostkey = hostkey_algs[j].alg;
6540 alg->u.hk.warn = warn;
6545 for (i = 0; i < s->n_preferred_hk; i++) {
6546 if (s->preferred_hk[i] == HK_WARN)
6548 for (j = 0; j < lenof(hostkey_algs); j++) {
6549 if (hostkey_algs[j].id != s->preferred_hk[i])
6551 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6552 hostkey_algs[j].alg->name);
6553 alg->u.hk.hostkey = hostkey_algs[j].alg;
6554 alg->u.hk.warn = warn;
6559 * In subsequent key exchanges, we list only the kex
6560 * algorithm that was selected in the first key exchange,
6561 * so that we keep getting the same host key and hence
6562 * don't have to interrupt the user's session to ask for
6566 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6567 ssh->hostkey->name);
6568 alg->u.hk.hostkey = ssh->hostkey;
6569 alg->u.hk.warn = FALSE;
6571 /* List encryption algorithms (client->server then server->client). */
6572 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6575 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6576 alg->u.cipher.cipher = NULL;
6577 alg->u.cipher.warn = warn;
6578 #endif /* FUZZING */
6579 for (i = 0; i < s->n_preferred_ciphers; i++) {
6580 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6581 if (!c) warn = TRUE;
6582 else for (j = 0; j < c->nciphers; j++) {
6583 alg = ssh2_kexinit_addalg(s->kexlists[k],
6585 alg->u.cipher.cipher = c->list[j];
6586 alg->u.cipher.warn = warn;
6590 /* List MAC algorithms (client->server then server->client). */
6591 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6593 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6594 alg->u.mac.mac = NULL;
6595 alg->u.mac.etm = FALSE;
6596 #endif /* FUZZING */
6597 for (i = 0; i < s->nmacs; i++) {
6598 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6599 alg->u.mac.mac = s->maclist[i];
6600 alg->u.mac.etm = FALSE;
6602 for (i = 0; i < s->nmacs; i++)
6603 /* For each MAC, there may also be an ETM version,
6604 * which we list second. */
6605 if (s->maclist[i]->etm_name) {
6606 alg = ssh2_kexinit_addalg(s->kexlists[j],
6607 s->maclist[i]->etm_name);
6608 alg->u.mac.mac = s->maclist[i];
6609 alg->u.mac.etm = TRUE;
6612 /* List client->server compression algorithms,
6613 * then server->client compression algorithms. (We use the
6614 * same set twice.) */
6615 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6616 assert(lenof(compressions) > 1);
6617 /* Prefer non-delayed versions */
6618 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6619 alg->u.comp = s->preferred_comp;
6620 /* We don't even list delayed versions of algorithms until
6621 * they're allowed to be used, to avoid a race. See the end of
6623 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6624 alg = ssh2_kexinit_addalg(s->kexlists[j],
6625 s->preferred_comp->delayed_name);
6626 alg->u.comp = s->preferred_comp;
6628 for (i = 0; i < lenof(compressions); i++) {
6629 const struct ssh_compress *c = compressions[i];
6630 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6632 if (s->userauth_succeeded && c->delayed_name) {
6633 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6639 * Construct and send our key exchange packet.
6641 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6642 for (i = 0; i < 16; i++)
6643 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6644 for (i = 0; i < NKEXLIST; i++) {
6645 ssh2_pkt_addstring_start(s->pktout);
6646 for (j = 0; j < MAXKEXLIST; j++) {
6647 if (s->kexlists[i][j].name == NULL) break;
6648 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6651 /* List client->server languages. Empty list. */
6652 ssh2_pkt_addstring_start(s->pktout);
6653 /* List server->client languages. Empty list. */
6654 ssh2_pkt_addstring_start(s->pktout);
6655 /* First KEX packet does _not_ follow, because we're not that brave. */
6656 ssh2_pkt_addbool(s->pktout, FALSE);
6658 ssh2_pkt_adduint32(s->pktout, 0);
6661 s->our_kexinitlen = s->pktout->length - 5;
6662 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6663 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6665 ssh2_pkt_send_noqueue(ssh, s->pktout);
6668 crWaitUntilV(pktin);
6671 * Now examine the other side's KEXINIT to see what we're up
6678 if (pktin->type != SSH2_MSG_KEXINIT) {
6679 bombout(("expected key exchange packet from server"));
6683 ssh->hostkey = NULL;
6684 s->cscipher_tobe = NULL;
6685 s->sccipher_tobe = NULL;
6686 s->csmac_tobe = NULL;
6687 s->scmac_tobe = NULL;
6688 s->cscomp_tobe = NULL;
6689 s->sccomp_tobe = NULL;
6690 s->warn_kex = s->warn_hk = FALSE;
6691 s->warn_cscipher = s->warn_sccipher = FALSE;
6693 pktin->savedpos += 16; /* skip garbage cookie */
6696 for (i = 0; i < NKEXLIST; i++) {
6697 ssh_pkt_getstring(pktin, &str, &len);
6699 bombout(("KEXINIT packet was incomplete"));
6703 /* If we've already selected a cipher which requires a
6704 * particular MAC, then just select that, and don't even
6705 * bother looking through the server's KEXINIT string for
6707 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6708 s->cscipher_tobe->required_mac) {
6709 s->csmac_tobe = s->cscipher_tobe->required_mac;
6710 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6713 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6714 s->sccipher_tobe->required_mac) {
6715 s->scmac_tobe = s->sccipher_tobe->required_mac;
6716 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6720 for (j = 0; j < MAXKEXLIST; j++) {
6721 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6722 if (alg->name == NULL) break;
6723 if (in_commasep_string(alg->name, str, len)) {
6724 /* We've found a matching algorithm. */
6725 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6726 /* Check if we might need to ignore first kex pkt */
6728 !first_in_commasep_string(alg->name, str, len))
6731 if (i == KEXLIST_KEX) {
6732 ssh->kex = alg->u.kex.kex;
6733 s->warn_kex = alg->u.kex.warn;
6734 } else if (i == KEXLIST_HOSTKEY) {
6735 ssh->hostkey = alg->u.hk.hostkey;
6736 s->warn_hk = alg->u.hk.warn;
6737 } else if (i == KEXLIST_CSCIPHER) {
6738 s->cscipher_tobe = alg->u.cipher.cipher;
6739 s->warn_cscipher = alg->u.cipher.warn;
6740 } else if (i == KEXLIST_SCCIPHER) {
6741 s->sccipher_tobe = alg->u.cipher.cipher;
6742 s->warn_sccipher = alg->u.cipher.warn;
6743 } else if (i == KEXLIST_CSMAC) {
6744 s->csmac_tobe = alg->u.mac.mac;
6745 s->csmac_etm_tobe = alg->u.mac.etm;
6746 } else if (i == KEXLIST_SCMAC) {
6747 s->scmac_tobe = alg->u.mac.mac;
6748 s->scmac_etm_tobe = alg->u.mac.etm;
6749 } else if (i == KEXLIST_CSCOMP) {
6750 s->cscomp_tobe = alg->u.comp;
6751 } else if (i == KEXLIST_SCCOMP) {
6752 s->sccomp_tobe = alg->u.comp;
6756 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6757 in_commasep_string(alg->u.comp->delayed_name, str, len))
6758 s->pending_compression = TRUE; /* try this later */
6760 bombout(("Couldn't agree a %s (available: %.*s)",
6761 kexlist_descr[i], len, str));
6765 if (i == KEXLIST_HOSTKEY) {
6769 * In addition to deciding which host key we're
6770 * actually going to use, we should make a list of the
6771 * host keys offered by the server which we _don't_
6772 * have cached. These will be offered as cross-
6773 * certification options by ssh_get_specials.
6775 * We also count the key we're currently using for KEX
6776 * as one we've already got, because by the time this
6777 * menu becomes visible, it will be.
6779 ssh->n_uncert_hostkeys = 0;
6781 for (j = 0; j < lenof(hostkey_algs); j++) {
6782 if (hostkey_algs[j].alg != ssh->hostkey &&
6783 in_commasep_string(hostkey_algs[j].alg->name,
6785 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6786 hostkey_algs[j].alg->keytype)) {
6787 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6793 if (s->pending_compression) {
6794 logevent("Server supports delayed compression; "
6795 "will try this later");
6797 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6798 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6799 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6801 ssh->exhash = ssh->kex->hash->init();
6802 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6803 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6804 hash_string(ssh->kex->hash, ssh->exhash,
6805 s->our_kexinit, s->our_kexinitlen);
6806 sfree(s->our_kexinit);
6807 /* Include the type byte in the hash of server's KEXINIT */
6808 hash_string(ssh->kex->hash, ssh->exhash,
6809 pktin->body - 1, pktin->length + 1);
6812 ssh_set_frozen(ssh, 1);
6813 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6815 ssh_dialog_callback, ssh);
6816 if (s->dlgret < 0) {
6820 bombout(("Unexpected data from server while"
6821 " waiting for user response"));
6824 } while (pktin || inlen > 0);
6825 s->dlgret = ssh->user_response;
6827 ssh_set_frozen(ssh, 0);
6828 if (s->dlgret == 0) {
6829 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6839 ssh_set_frozen(ssh, 1);
6842 * Change warning box wording depending on why we chose a
6843 * warning-level host key algorithm. If it's because
6844 * that's all we have *cached*, use the askhk mechanism,
6845 * and list the host keys we could usefully cross-certify.
6846 * Otherwise, use askalg for the standard wording.
6849 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6850 const struct ssh_signkey_with_user_pref_id *hktype =
6851 &hostkey_algs[ssh->uncert_hostkeys[j]];
6853 for (k = 0; k < HK_MAX; k++) {
6854 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6855 if (id == HK_WARN) {
6857 } else if (id == hktype->id) {
6864 char *old_ba = betteralgs;
6865 betteralgs = dupcat(betteralgs, ",",
6867 (const char *)NULL);
6870 betteralgs = dupstr(hktype->alg->name);
6875 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6876 betteralgs, ssh_dialog_callback, ssh);
6879 s->dlgret = askalg(ssh->frontend, "host key type",
6881 ssh_dialog_callback, ssh);
6883 if (s->dlgret < 0) {
6887 bombout(("Unexpected data from server while"
6888 " waiting for user response"));
6891 } while (pktin || inlen > 0);
6892 s->dlgret = ssh->user_response;
6894 ssh_set_frozen(ssh, 0);
6895 if (s->dlgret == 0) {
6896 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6902 if (s->warn_cscipher) {
6903 ssh_set_frozen(ssh, 1);
6904 s->dlgret = askalg(ssh->frontend,
6905 "client-to-server cipher",
6906 s->cscipher_tobe->name,
6907 ssh_dialog_callback, ssh);
6908 if (s->dlgret < 0) {
6912 bombout(("Unexpected data from server while"
6913 " waiting for user response"));
6916 } while (pktin || inlen > 0);
6917 s->dlgret = ssh->user_response;
6919 ssh_set_frozen(ssh, 0);
6920 if (s->dlgret == 0) {
6921 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6927 if (s->warn_sccipher) {
6928 ssh_set_frozen(ssh, 1);
6929 s->dlgret = askalg(ssh->frontend,
6930 "server-to-client cipher",
6931 s->sccipher_tobe->name,
6932 ssh_dialog_callback, ssh);
6933 if (s->dlgret < 0) {
6937 bombout(("Unexpected data from server while"
6938 " waiting for user response"));
6941 } while (pktin || inlen > 0);
6942 s->dlgret = ssh->user_response;
6944 ssh_set_frozen(ssh, 0);
6945 if (s->dlgret == 0) {
6946 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6952 if (s->ignorepkt) /* first_kex_packet_follows */
6953 crWaitUntilV(pktin); /* Ignore packet */
6956 if (ssh->kex->main_type == KEXTYPE_DH) {
6958 * Work out the number of bits of key we will need from the
6959 * key exchange. We start with the maximum key length of
6965 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6966 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6967 s->nbits = (csbits > scbits ? csbits : scbits);
6969 /* The keys only have hlen-bit entropy, since they're based on
6970 * a hash. So cap the key size at hlen bits. */
6971 if (s->nbits > ssh->kex->hash->hlen * 8)
6972 s->nbits = ssh->kex->hash->hlen * 8;
6975 * If we're doing Diffie-Hellman group exchange, start by
6976 * requesting a group.
6978 if (dh_is_gex(ssh->kex)) {
6979 logevent("Doing Diffie-Hellman group exchange");
6980 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6982 * Work out how big a DH group we will need to allow that
6985 s->pbits = 512 << ((s->nbits - 1) / 64);
6986 if (s->pbits < DH_MIN_SIZE)
6987 s->pbits = DH_MIN_SIZE;
6988 if (s->pbits > DH_MAX_SIZE)
6989 s->pbits = DH_MAX_SIZE;
6990 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6991 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6992 ssh2_pkt_adduint32(s->pktout, s->pbits);
6994 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6995 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6996 ssh2_pkt_adduint32(s->pktout, s->pbits);
6997 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6999 ssh2_pkt_send_noqueue(ssh, s->pktout);
7001 crWaitUntilV(pktin);
7002 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
7003 bombout(("expected key exchange group packet from server"));
7006 s->p = ssh2_pkt_getmp(pktin);
7007 s->g = ssh2_pkt_getmp(pktin);
7008 if (!s->p || !s->g) {
7009 bombout(("unable to read mp-ints from incoming group packet"));
7012 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
7013 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
7014 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
7016 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
7017 ssh->kex_ctx = dh_setup_group(ssh->kex);
7018 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
7019 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
7020 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
7021 ssh->kex->groupname);
7024 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
7025 ssh->kex->hash->text_name);
7027 * Now generate and send e for Diffie-Hellman.
7029 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
7030 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
7031 s->pktout = ssh2_pkt_init(s->kex_init_value);
7032 ssh2_pkt_addmp(s->pktout, s->e);
7033 ssh2_pkt_send_noqueue(ssh, s->pktout);
7035 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
7036 crWaitUntilV(pktin);
7037 if (pktin->type != s->kex_reply_value) {
7038 bombout(("expected key exchange reply packet from server"));
7041 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
7042 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7043 if (!s->hostkeydata) {
7044 bombout(("unable to parse key exchange reply packet"));
7047 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7048 s->hostkeydata, s->hostkeylen);
7049 s->f = ssh2_pkt_getmp(pktin);
7051 bombout(("unable to parse key exchange reply packet"));
7054 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7056 bombout(("unable to parse key exchange reply packet"));
7061 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7063 bombout(("key exchange reply failed validation: %s", err));
7067 s->K = dh_find_K(ssh->kex_ctx, s->f);
7069 /* We assume everything from now on will be quick, and it might
7070 * involve user interaction. */
7071 set_busy_status(ssh->frontend, BUSY_NOT);
7073 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7074 if (dh_is_gex(ssh->kex)) {
7075 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7076 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7077 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7078 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7079 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7080 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7081 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7083 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7084 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7086 dh_cleanup(ssh->kex_ctx);
7088 if (dh_is_gex(ssh->kex)) {
7092 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7094 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7095 ssh_ecdhkex_curve_textname(ssh->kex),
7096 ssh->kex->hash->text_name);
7097 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7099 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7101 bombout(("Unable to generate key for ECDH"));
7107 int publicPointLength;
7108 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7110 ssh_ecdhkex_freekey(s->eckey);
7111 bombout(("Unable to encode public key for ECDH"));
7114 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7115 ssh2_pkt_addstring_start(s->pktout);
7116 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7120 ssh2_pkt_send_noqueue(ssh, s->pktout);
7122 crWaitUntilV(pktin);
7123 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7124 ssh_ecdhkex_freekey(s->eckey);
7125 bombout(("expected ECDH reply packet from server"));
7129 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7130 if (!s->hostkeydata) {
7131 bombout(("unable to parse ECDH reply packet"));
7134 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7135 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7136 s->hostkeydata, s->hostkeylen);
7140 int publicPointLength;
7141 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7143 ssh_ecdhkex_freekey(s->eckey);
7144 bombout(("Unable to encode public key for ECDH hash"));
7147 hash_string(ssh->kex->hash, ssh->exhash,
7148 publicPoint, publicPointLength);
7155 ssh_pkt_getstring(pktin, &keydata, &keylen);
7157 bombout(("unable to parse ECDH reply packet"));
7160 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7161 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7163 ssh_ecdhkex_freekey(s->eckey);
7164 bombout(("point received in ECDH was not valid"));
7169 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7171 bombout(("unable to parse key exchange reply packet"));
7175 ssh_ecdhkex_freekey(s->eckey);
7177 logeventf(ssh, "Doing RSA key exchange with hash %s",
7178 ssh->kex->hash->text_name);
7179 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7181 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7184 crWaitUntilV(pktin);
7185 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7186 bombout(("expected RSA public key packet from server"));
7190 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7191 if (!s->hostkeydata) {
7192 bombout(("unable to parse RSA public key packet"));
7195 hash_string(ssh->kex->hash, ssh->exhash,
7196 s->hostkeydata, s->hostkeylen);
7197 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7198 s->hostkeydata, s->hostkeylen);
7202 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7204 bombout(("unable to parse RSA public key packet"));
7207 s->rsakeydata = snewn(s->rsakeylen, char);
7208 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7211 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7213 sfree(s->rsakeydata);
7214 bombout(("unable to parse RSA public key from server"));
7218 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7221 * Next, set up a shared secret K, of precisely KLEN -
7222 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7223 * RSA key modulus and HLEN is the bit length of the hash
7227 int klen = ssh_rsakex_klen(s->rsakey);
7228 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7230 unsigned char *kstr1, *kstr2, *outstr;
7231 int kstr1len, kstr2len, outstrlen;
7233 s->K = bn_power_2(nbits - 1);
7235 for (i = 0; i < nbits; i++) {
7237 byte = random_byte();
7239 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7243 * Encode this as an mpint.
7245 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7246 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7247 PUT_32BIT(kstr2, kstr1len);
7248 memcpy(kstr2 + 4, kstr1, kstr1len);
7251 * Encrypt it with the given RSA key.
7253 outstrlen = (klen + 7) / 8;
7254 outstr = snewn(outstrlen, unsigned char);
7255 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7256 outstr, outstrlen, s->rsakey);
7259 * And send it off in a return packet.
7261 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7262 ssh2_pkt_addstring_start(s->pktout);
7263 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7264 ssh2_pkt_send_noqueue(ssh, s->pktout);
7266 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7273 ssh_rsakex_freekey(s->rsakey);
7275 crWaitUntilV(pktin);
7276 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7277 sfree(s->rsakeydata);
7278 bombout(("expected signature packet from server"));
7282 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7284 bombout(("unable to parse signature packet"));
7288 sfree(s->rsakeydata);
7291 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7292 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7293 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7295 ssh->kex_ctx = NULL;
7298 debug(("Exchange hash is:\n"));
7299 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7303 bombout(("Server's host key is invalid"));
7307 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7308 (char *)s->exchange_hash,
7309 ssh->kex->hash->hlen)) {
7311 bombout(("Server's host key did not match the signature supplied"));
7316 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7317 if (!s->got_session_id) {
7319 * Make a note of any other host key formats that are available.
7322 int i, j, nkeys = 0;
7324 for (i = 0; i < lenof(hostkey_algs); i++) {
7325 if (hostkey_algs[i].alg == ssh->hostkey)
7328 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7329 if (ssh->uncert_hostkeys[j] == i)
7332 if (j < ssh->n_uncert_hostkeys) {
7335 newlist = dupprintf("%s/%s", list,
7336 hostkey_algs[i].alg->name);
7338 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7346 "Server also has %s host key%s, but we "
7347 "don't know %s", list,
7348 nkeys > 1 ? "s" : "",
7349 nkeys > 1 ? "any of them" : "it");
7355 * Authenticate remote host: verify host key. (We've already
7356 * checked the signature of the exchange hash.)
7358 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7359 logevent("Host key fingerprint is:");
7360 logevent(s->fingerprint);
7361 /* First check against manually configured host keys. */
7362 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7363 ssh->hostkey, s->hkey);
7364 if (s->dlgret == 0) { /* did not match */
7365 bombout(("Host key did not appear in manually configured list"));
7367 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7368 ssh_set_frozen(ssh, 1);
7369 s->dlgret = verify_ssh_host_key(ssh->frontend,
7370 ssh->savedhost, ssh->savedport,
7371 ssh->hostkey->keytype, s->keystr,
7373 ssh_dialog_callback, ssh);
7377 if (s->dlgret < 0) {
7381 bombout(("Unexpected data from server while waiting"
7382 " for user host key response"));
7385 } while (pktin || inlen > 0);
7386 s->dlgret = ssh->user_response;
7388 ssh_set_frozen(ssh, 0);
7389 if (s->dlgret == 0) {
7390 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7395 sfree(s->fingerprint);
7397 * Save this host key, to check against the one presented in
7398 * subsequent rekeys.
7400 ssh->hostkey_str = s->keystr;
7401 } else if (ssh->cross_certifying) {
7402 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7403 logevent("Storing additional host key for this host:");
7404 logevent(s->fingerprint);
7405 sfree(s->fingerprint);
7406 store_host_key(ssh->savedhost, ssh->savedport,
7407 ssh->hostkey->keytype, s->keystr);
7408 ssh->cross_certifying = FALSE;
7410 * Don't forget to store the new key as the one we'll be
7411 * re-checking in future normal rekeys.
7413 ssh->hostkey_str = s->keystr;
7416 * In a rekey, we never present an interactive host key
7417 * verification request to the user. Instead, we simply
7418 * enforce that the key we're seeing this time is identical to
7419 * the one we saw before.
7421 if (strcmp(ssh->hostkey_str, s->keystr)) {
7423 bombout(("Host key was different in repeat key exchange"));
7429 ssh->hostkey->freekey(s->hkey);
7432 * The exchange hash from the very first key exchange is also
7433 * the session id, used in session key construction and
7436 if (!s->got_session_id) {
7437 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7438 memcpy(ssh->v2_session_id, s->exchange_hash,
7439 sizeof(s->exchange_hash));
7440 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7441 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7442 s->got_session_id = TRUE;
7446 * Send SSH2_MSG_NEWKEYS.
7448 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7449 ssh2_pkt_send_noqueue(ssh, s->pktout);
7450 ssh->outgoing_data_size = 0; /* start counting from here */
7453 * We've sent client NEWKEYS, so create and initialise
7454 * client-to-server session keys.
7456 if (ssh->cs_cipher_ctx)
7457 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7458 ssh->cscipher = s->cscipher_tobe;
7459 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7461 if (ssh->cs_mac_ctx)
7462 ssh->csmac->free_context(ssh->cs_mac_ctx);
7463 ssh->csmac = s->csmac_tobe;
7464 ssh->csmac_etm = s->csmac_etm_tobe;
7466 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7468 if (ssh->cs_comp_ctx)
7469 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7470 ssh->cscomp = s->cscomp_tobe;
7471 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7474 * Set IVs on client-to-server keys. Here we use the exchange
7475 * hash from the _first_ key exchange.
7477 if (ssh->cscipher) {
7480 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7481 ssh->cscipher->padded_keybytes);
7482 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7483 smemclr(key, ssh->cscipher->padded_keybytes);
7486 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7487 ssh->cscipher->blksize);
7488 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7489 smemclr(key, ssh->cscipher->blksize);
7495 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7496 ssh->csmac->keylen);
7497 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7498 smemclr(key, ssh->csmac->keylen);
7503 logeventf(ssh, "Initialised %.200s client->server encryption",
7504 ssh->cscipher->text_name);
7506 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7507 ssh->csmac->text_name,
7508 ssh->csmac_etm ? " (in ETM mode)" : "",
7509 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7510 if (ssh->cscomp->text_name)
7511 logeventf(ssh, "Initialised %s compression",
7512 ssh->cscomp->text_name);
7515 * Now our end of the key exchange is complete, we can send all
7516 * our queued higher-layer packets.
7518 ssh->queueing = FALSE;
7519 ssh2_pkt_queuesend(ssh);
7522 * Expect SSH2_MSG_NEWKEYS from server.
7524 crWaitUntilV(pktin);
7525 if (pktin->type != SSH2_MSG_NEWKEYS) {
7526 bombout(("expected new-keys packet from server"));
7529 ssh->incoming_data_size = 0; /* start counting from here */
7532 * We've seen server NEWKEYS, so create and initialise
7533 * server-to-client session keys.
7535 if (ssh->sc_cipher_ctx)
7536 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7537 if (s->sccipher_tobe) {
7538 ssh->sccipher = s->sccipher_tobe;
7539 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7542 if (ssh->sc_mac_ctx)
7543 ssh->scmac->free_context(ssh->sc_mac_ctx);
7544 if (s->scmac_tobe) {
7545 ssh->scmac = s->scmac_tobe;
7546 ssh->scmac_etm = s->scmac_etm_tobe;
7547 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7550 if (ssh->sc_comp_ctx)
7551 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7552 ssh->sccomp = s->sccomp_tobe;
7553 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7556 * Set IVs on server-to-client keys. Here we use the exchange
7557 * hash from the _first_ key exchange.
7559 if (ssh->sccipher) {
7562 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7563 ssh->sccipher->padded_keybytes);
7564 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7565 smemclr(key, ssh->sccipher->padded_keybytes);
7568 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7569 ssh->sccipher->blksize);
7570 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7571 smemclr(key, ssh->sccipher->blksize);
7577 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7578 ssh->scmac->keylen);
7579 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7580 smemclr(key, ssh->scmac->keylen);
7584 logeventf(ssh, "Initialised %.200s server->client encryption",
7585 ssh->sccipher->text_name);
7587 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7588 ssh->scmac->text_name,
7589 ssh->scmac_etm ? " (in ETM mode)" : "",
7590 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7591 if (ssh->sccomp->text_name)
7592 logeventf(ssh, "Initialised %s decompression",
7593 ssh->sccomp->text_name);
7596 * Free shared secret.
7601 * Update the specials menu to list the remaining uncertified host
7604 update_specials_menu(ssh->frontend);
7607 * Key exchange is over. Loop straight back round if we have a
7608 * deferred rekey reason.
7610 if (ssh->deferred_rekey_reason) {
7611 logevent(ssh->deferred_rekey_reason);
7613 ssh->deferred_rekey_reason = NULL;
7614 goto begin_key_exchange;
7618 * Otherwise, schedule a timer for our next rekey.
7620 ssh->kex_in_progress = FALSE;
7621 ssh->last_rekey = GETTICKCOUNT();
7622 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7623 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7627 * Now we're encrypting. Begin returning 1 to the protocol main
7628 * function so that other things can run on top of the
7629 * transport. If we ever see a KEXINIT, we must go back to the
7632 * We _also_ go back to the start if we see pktin==NULL and
7633 * inlen negative, because this is a special signal meaning
7634 * `initiate client-driven rekey', and `in' contains a message
7635 * giving the reason for the rekey.
7637 * inlen==-1 means always initiate a rekey;
7638 * inlen==-2 means that userauth has completed successfully and
7639 * we should consider rekeying (for delayed compression).
7641 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7642 (!pktin && inlen < 0))) {
7644 if (!ssh->protocol_initial_phase_done) {
7645 ssh->protocol_initial_phase_done = TRUE;
7647 * Allow authconn to initialise itself.
7649 do_ssh2_authconn(ssh, NULL, 0, NULL);
7654 logevent("Server initiated key re-exchange");
7658 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7659 * delayed compression, if it's available.
7661 * draft-miller-secsh-compression-delayed-00 says that you
7662 * negotiate delayed compression in the first key exchange, and
7663 * both sides start compressing when the server has sent
7664 * USERAUTH_SUCCESS. This has a race condition -- the server
7665 * can't know when the client has seen it, and thus which incoming
7666 * packets it should treat as compressed.
7668 * Instead, we do the initial key exchange without offering the
7669 * delayed methods, but note if the server offers them; when we
7670 * get here, if a delayed method was available that was higher
7671 * on our list than what we got, we initiate a rekey in which we
7672 * _do_ list the delayed methods (and hopefully get it as a
7673 * result). Subsequent rekeys will do the same.
7675 assert(!s->userauth_succeeded); /* should only happen once */
7676 s->userauth_succeeded = TRUE;
7677 if (!s->pending_compression)
7678 /* Can't see any point rekeying. */
7679 goto wait_for_rekey; /* this is utterly horrid */
7680 /* else fall through to rekey... */
7681 s->pending_compression = FALSE;
7684 * Now we've decided to rekey.
7686 * Special case: if the server bug is set that doesn't
7687 * allow rekeying, we give a different log message and
7688 * continue waiting. (If such a server _initiates_ a rekey,
7689 * we process it anyway!)
7691 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7692 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7694 /* Reset the counters, so that at least this message doesn't
7695 * hit the event log _too_ often. */
7696 ssh->outgoing_data_size = 0;
7697 ssh->incoming_data_size = 0;
7698 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7700 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7703 goto wait_for_rekey; /* this is still utterly horrid */
7705 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7708 goto begin_key_exchange;
7714 * Send data on an SSH channel. In SSH-2, this involves buffering it
7717 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7720 if (c->ssh->version == 2) {
7721 bufchain_add(&c->v.v2.outbuffer, buf, len);
7722 return ssh2_try_send(c);
7724 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7725 PKT_INT, c->remoteid,
7730 * In SSH-1 we can return 0 here - implying that channels are
7731 * never individually throttled - because the only
7732 * circumstance that can cause throttling will be the whole
7733 * SSH connection backing up, in which case _everything_ will
7734 * be throttled as a whole.
7741 * Attempt to send data on an SSH-2 channel.
7743 static int ssh2_try_send(struct ssh_channel *c)
7746 struct Packet *pktout;
7749 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7752 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7753 if ((unsigned)len > c->v.v2.remwindow)
7754 len = c->v.v2.remwindow;
7755 if ((unsigned)len > c->v.v2.remmaxpkt)
7756 len = c->v.v2.remmaxpkt;
7757 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7758 ssh2_pkt_adduint32(pktout, c->remoteid);
7759 ssh2_pkt_addstring_start(pktout);
7760 ssh2_pkt_addstring_data(pktout, data, len);
7761 ssh2_pkt_send(ssh, pktout);
7762 bufchain_consume(&c->v.v2.outbuffer, len);
7763 c->v.v2.remwindow -= len;
7767 * After having sent as much data as we can, return the amount
7770 ret = bufchain_size(&c->v.v2.outbuffer);
7773 * And if there's no data pending but we need to send an EOF, send
7776 if (!ret && c->pending_eof)
7777 ssh_channel_try_eof(c);
7782 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7785 if (c->closes & CLOSES_SENT_EOF)
7786 return; /* don't send on channels we've EOFed */
7787 bufsize = ssh2_try_send(c);
7790 case CHAN_MAINSESSION:
7791 /* stdin need not receive an unthrottle
7792 * notification since it will be polled */
7795 x11_unthrottle(c->u.x11.xconn);
7798 /* Now that we've successfully sent all the outgoing
7799 * replies we had, try to process more incoming data. */
7800 ssh_agentf_try_forward(c);
7803 pfd_unthrottle(c->u.pfd.pf);
7809 static int ssh_is_simple(Ssh ssh)
7812 * We use the 'simple' variant of the SSH protocol if we're asked
7813 * to, except not if we're also doing connection-sharing (either
7814 * tunnelling our packets over an upstream or expecting to be
7815 * tunnelled over ourselves), since then the assumption that we
7816 * have only one channel to worry about is not true after all.
7818 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7819 !ssh->bare_connection && !ssh->connshare);
7823 * Set up most of a new ssh_channel.
7825 static void ssh_channel_init(struct ssh_channel *c)
7828 c->localid = alloc_channel_id(ssh);
7830 c->pending_eof = FALSE;
7831 c->throttling_conn = FALSE;
7832 if (ssh->version == 2) {
7833 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7834 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7835 c->v.v2.chanreq_head = NULL;
7836 c->v.v2.throttle_state = UNTHROTTLED;
7837 bufchain_init(&c->v.v2.outbuffer);
7839 add234(ssh->channels, c);
7843 * Construct the common parts of a CHANNEL_OPEN.
7845 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7848 struct Packet *pktout;
7850 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7851 ssh2_pkt_addstring(pktout, type);
7852 ssh2_pkt_adduint32(pktout, c->localid);
7853 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7854 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7859 * CHANNEL_FAILURE doesn't come with any indication of what message
7860 * caused it, so we have to keep track of the outstanding
7861 * CHANNEL_REQUESTs ourselves.
7863 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7864 cchandler_fn_t handler, void *ctx)
7866 struct outstanding_channel_request *ocr =
7867 snew(struct outstanding_channel_request);
7869 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7870 ocr->handler = handler;
7873 if (!c->v.v2.chanreq_head)
7874 c->v.v2.chanreq_head = ocr;
7876 c->v.v2.chanreq_tail->next = ocr;
7877 c->v.v2.chanreq_tail = ocr;
7881 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7882 * NULL then a reply will be requested and the handler will be called
7883 * when it arrives. The returned packet is ready to have any
7884 * request-specific data added and be sent. Note that if a handler is
7885 * provided, it's essential that the request actually be sent.
7887 * The handler will usually be passed the response packet in pktin. If
7888 * pktin is NULL, this means that no reply will ever be forthcoming
7889 * (e.g. because the entire connection is being destroyed, or because
7890 * the server initiated channel closure before we saw the response)
7891 * and the handler should free any storage it's holding.
7893 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7895 cchandler_fn_t handler, void *ctx)
7897 struct Packet *pktout;
7899 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7900 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7901 ssh2_pkt_adduint32(pktout, c->remoteid);
7902 ssh2_pkt_addstring(pktout, type);
7903 ssh2_pkt_addbool(pktout, handler != NULL);
7904 if (handler != NULL)
7905 ssh2_queue_chanreq_handler(c, handler, ctx);
7909 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize)
7914 if (ssh->version == 1) {
7915 buflimit = SSH1_BUFFER_LIMIT;
7917 if (ssh_is_simple(ssh))
7920 buflimit = c->v.v2.locmaxwin;
7921 if (bufsize < buflimit)
7922 ssh2_set_window(c, buflimit - bufsize);
7924 if (c->throttling_conn && bufsize <= buflimit) {
7925 c->throttling_conn = 0;
7926 ssh_throttle_conn(ssh, -1);
7931 * Potentially enlarge the window on an SSH-2 channel.
7933 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7935 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7940 * Never send WINDOW_ADJUST for a channel that the remote side has
7941 * already sent EOF on; there's no point, since it won't be
7942 * sending any more data anyway. Ditto if _we've_ already sent
7945 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7949 * Also, never widen the window for an X11 channel when we're
7950 * still waiting to see its initial auth and may yet hand it off
7953 if (c->type == CHAN_X11 && c->u.x11.initial)
7957 * If the remote end has a habit of ignoring maxpkt, limit the
7958 * window so that it has no choice (assuming it doesn't ignore the
7961 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7962 newwin = OUR_V2_MAXPKT;
7965 * Only send a WINDOW_ADJUST if there's significantly more window
7966 * available than the other end thinks there is. This saves us
7967 * sending a WINDOW_ADJUST for every character in a shell session.
7969 * "Significant" is arbitrarily defined as half the window size.
7971 if (newwin / 2 >= c->v.v2.locwindow) {
7972 struct Packet *pktout;
7976 * In order to keep track of how much window the client
7977 * actually has available, we'd like it to acknowledge each
7978 * WINDOW_ADJUST. We can't do that directly, so we accompany
7979 * it with a CHANNEL_REQUEST that has to be acknowledged.
7981 * This is only necessary if we're opening the window wide.
7982 * If we're not, then throughput is being constrained by
7983 * something other than the maximum window size anyway.
7985 if (newwin == c->v.v2.locmaxwin &&
7986 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7987 up = snew(unsigned);
7988 *up = newwin - c->v.v2.locwindow;
7989 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7990 ssh2_handle_winadj_response, up);
7991 ssh2_pkt_send(ssh, pktout);
7993 if (c->v.v2.throttle_state != UNTHROTTLED)
7994 c->v.v2.throttle_state = UNTHROTTLING;
7996 /* Pretend the WINDOW_ADJUST was acked immediately. */
7997 c->v.v2.remlocwin = newwin;
7998 c->v.v2.throttle_state = THROTTLED;
8000 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
8001 ssh2_pkt_adduint32(pktout, c->remoteid);
8002 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
8003 ssh2_pkt_send(ssh, pktout);
8004 c->v.v2.locwindow = newwin;
8009 * Find the channel associated with a message. If there's no channel,
8010 * or it's not properly open, make a noise about it and return NULL.
8011 * If the channel is shared, pass the message on to downstream and
8012 * also return NULL (meaning the caller should ignore this message).
8014 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin)
8016 unsigned localid = ssh_pkt_getuint32(pktin);
8017 struct ssh_channel *c;
8020 /* Is this message OK on a half-open connection? */
8021 if (ssh->version == 1)
8022 halfopen_ok = (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION ||
8023 pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE);
8025 halfopen_ok = (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION ||
8026 pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE);
8027 c = find234(ssh->channels, &localid, ssh_channelfind);
8028 if (!c || (c->type != CHAN_SHARING && (c->halfopen != halfopen_ok))) {
8029 char *buf = dupprintf("Received %s for %s channel %u",
8030 ssh_pkt_type(ssh, pktin->type),
8031 !c ? "nonexistent" :
8032 c->halfopen ? "half-open" : "open",
8034 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
8038 if (c->type == CHAN_SHARING) {
8039 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8040 pktin->body, pktin->length);
8046 static void ssh2_handle_winadj_response(struct ssh_channel *c,
8047 struct Packet *pktin, void *ctx)
8049 unsigned *sizep = ctx;
8052 * Winadj responses should always be failures. However, at least
8053 * one server ("boks_sshd") is known to return SUCCESS for channel
8054 * requests it's never heard of, such as "winadj@putty". Raised
8055 * with foxt.com as bug 090916-090424, but for the sake of a quiet
8056 * life, we don't worry about what kind of response we got.
8059 c->v.v2.remlocwin += *sizep;
8062 * winadj messages are only sent when the window is fully open, so
8063 * if we get an ack of one, we know any pending unthrottle is
8066 if (c->v.v2.throttle_state == UNTHROTTLING)
8067 c->v.v2.throttle_state = UNTHROTTLED;
8070 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
8072 struct ssh_channel *c = ssh_channel_msg(ssh, pktin);
8073 struct outstanding_channel_request *ocr;
8076 ocr = c->v.v2.chanreq_head;
8078 ssh2_msg_unexpected(ssh, pktin);
8081 ocr->handler(c, pktin, ocr->ctx);
8082 c->v.v2.chanreq_head = ocr->next;
8085 * We may now initiate channel-closing procedures, if that
8086 * CHANNEL_REQUEST was the last thing outstanding before we send
8089 ssh2_channel_check_close(c);
8092 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8094 struct ssh_channel *c;
8095 c = ssh_channel_msg(ssh, pktin);
8098 if (!(c->closes & CLOSES_SENT_EOF)) {
8099 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
8100 ssh2_try_send_and_unthrottle(ssh, c);
8104 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8108 unsigned ext_type = 0; /* 0 means not extended */
8109 struct ssh_channel *c;
8110 c = ssh_channel_msg(ssh, pktin);
8113 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
8114 ext_type = ssh_pkt_getuint32(pktin);
8115 ssh_pkt_getstring(pktin, &data, &length);
8118 c->v.v2.locwindow -= length;
8119 c->v.v2.remlocwin -= length;
8120 if (ext_type != 0 && ext_type != SSH2_EXTENDED_DATA_STDERR)
8121 length = 0; /* Don't do anything with unknown extended data. */
8122 bufsize = ssh_channel_data(c, ext_type == SSH2_EXTENDED_DATA_STDERR,
8125 * If it looks like the remote end hit the end of its window,
8126 * and we didn't want it to do that, think about using a
8129 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8130 c->v.v2.locmaxwin < 0x40000000)
8131 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8133 * If we are not buffering too much data,
8134 * enlarge the window again at the remote side.
8135 * If we are buffering too much, we may still
8136 * need to adjust the window if the server's
8139 if (bufsize < c->v.v2.locmaxwin)
8140 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
8142 * If we're either buffering way too much data, or if we're
8143 * buffering anything at all and we're in "simple" mode,
8144 * throttle the whole channel.
8146 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8147 && !c->throttling_conn) {
8148 c->throttling_conn = 1;
8149 ssh_throttle_conn(ssh, +1);
8154 static void ssh_check_termination(Ssh ssh)
8156 if (ssh->version == 2 &&
8157 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8158 (ssh->channels && count234(ssh->channels) == 0) &&
8159 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8161 * We used to send SSH_MSG_DISCONNECT here, because I'd
8162 * believed that _every_ conforming SSH-2 connection had to
8163 * end with a disconnect being sent by at least one side;
8164 * apparently I was wrong and it's perfectly OK to
8165 * unceremoniously slam the connection shut when you're done,
8166 * and indeed OpenSSH feels this is more polite than sending a
8167 * DISCONNECT. So now we don't.
8169 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8173 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8174 const char *peerinfo)
8177 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8180 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8183 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8185 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8186 ssh_check_termination(ssh);
8189 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8194 va_start(ap, logfmt);
8195 buf = dupvprintf(logfmt, ap);
8198 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8200 logeventf(ssh, "Connection sharing: %s", buf);
8205 * Close any local socket and free any local resources associated with
8206 * a channel. This converts the channel into a CHAN_ZOMBIE.
8208 static void ssh_channel_close_local(struct ssh_channel *c, char const *reason)
8211 char const *msg = NULL;
8214 case CHAN_MAINSESSION:
8215 ssh->mainchan = NULL;
8216 update_specials_menu(ssh->frontend);
8219 assert(c->u.x11.xconn != NULL);
8220 x11_close(c->u.x11.xconn);
8221 msg = "Forwarded X11 connection terminated";
8225 agent_cancel_query(c->u.a.pending);
8226 bufchain_clear(&c->u.a.inbuffer);
8227 msg = "Agent-forwarding connection closed";
8230 assert(c->u.pfd.pf != NULL);
8231 pfd_close(c->u.pfd.pf);
8232 msg = "Forwarded port closed";
8235 c->type = CHAN_ZOMBIE;
8238 logeventf(ssh, "%s %s", msg, reason);
8244 static void ssh_channel_destroy(struct ssh_channel *c)
8248 ssh_channel_close_local(c, NULL);
8250 del234(ssh->channels, c);
8251 if (ssh->version == 2) {
8252 bufchain_clear(&c->v.v2.outbuffer);
8253 assert(c->v.v2.chanreq_head == NULL);
8258 * If that was the last channel left open, we might need to
8261 ssh_check_termination(ssh);
8264 static void ssh2_channel_check_close(struct ssh_channel *c)
8267 struct Packet *pktout;
8269 assert(ssh->version == 2);
8272 * If we've sent out our own CHANNEL_OPEN but not yet seen
8273 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8274 * it's too early to be sending close messages of any kind.
8279 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8280 c->type == CHAN_ZOMBIE) &&
8281 !c->v.v2.chanreq_head &&
8282 !(c->closes & CLOSES_SENT_CLOSE)) {
8284 * We have both sent and received EOF (or the channel is a
8285 * zombie), and we have no outstanding channel requests, which
8286 * means the channel is in final wind-up. But we haven't sent
8287 * CLOSE, so let's do so now.
8289 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8290 ssh2_pkt_adduint32(pktout, c->remoteid);
8291 ssh2_pkt_send(ssh, pktout);
8292 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8295 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8296 assert(c->v.v2.chanreq_head == NULL);
8298 * We have both sent and received CLOSE, which means we're
8299 * completely done with the channel.
8301 ssh_channel_destroy(c);
8305 static void ssh_channel_got_eof(struct ssh_channel *c)
8307 if (c->closes & CLOSES_RCVD_EOF)
8308 return; /* already seen EOF */
8309 c->closes |= CLOSES_RCVD_EOF;
8311 if (c->type == CHAN_X11) {
8312 assert(c->u.x11.xconn != NULL);
8313 x11_send_eof(c->u.x11.xconn);
8314 } else if (c->type == CHAN_AGENT) {
8315 /* Just call try_forward, which will respond to the EOF now if
8316 * appropriate, or wait until the queue of outstanding
8317 * requests is dealt with if not */
8318 ssh_agentf_try_forward(c);
8319 } else if (c->type == CHAN_SOCKDATA) {
8320 assert(c->u.pfd.pf != NULL);
8321 pfd_send_eof(c->u.pfd.pf);
8322 } else if (c->type == CHAN_MAINSESSION) {
8325 if (!ssh->sent_console_eof &&
8326 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8328 * Either from_backend_eof told us that the front end
8329 * wants us to close the outgoing side of the connection
8330 * as soon as we see EOF from the far end, or else we've
8331 * unilaterally decided to do that because we've allocated
8332 * a remote pty and hence EOF isn't a particularly
8333 * meaningful concept.
8335 sshfwd_write_eof(c);
8337 ssh->sent_console_eof = TRUE;
8341 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8343 struct ssh_channel *c;
8345 c = ssh_channel_msg(ssh, pktin);
8348 ssh_channel_got_eof(c);
8349 ssh2_channel_check_close(c);
8352 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8354 struct ssh_channel *c;
8356 c = ssh_channel_msg(ssh, pktin);
8361 * When we receive CLOSE on a channel, we assume it comes with an
8362 * implied EOF if we haven't seen EOF yet.
8364 ssh_channel_got_eof(c);
8366 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8368 * It also means we stop expecting to see replies to any
8369 * outstanding channel requests, so clean those up too.
8370 * (ssh_chanreq_init will enforce by assertion that we don't
8371 * subsequently put anything back on this list.)
8373 while (c->v.v2.chanreq_head) {
8374 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8375 ocr->handler(c, NULL, ocr->ctx);
8376 c->v.v2.chanreq_head = ocr->next;
8382 * And we also send an outgoing EOF, if we haven't already, on the
8383 * assumption that CLOSE is a pretty forceful announcement that
8384 * the remote side is doing away with the entire channel. (If it
8385 * had wanted to send us EOF and continue receiving data from us,
8386 * it would have just sent CHANNEL_EOF.)
8388 if (!(c->closes & CLOSES_SENT_EOF)) {
8390 * Make sure we don't read any more from whatever our local
8391 * data source is for this channel.
8394 case CHAN_MAINSESSION:
8395 ssh->send_ok = 0; /* stop trying to read from stdin */
8398 x11_override_throttle(c->u.x11.xconn, 1);
8401 pfd_override_throttle(c->u.pfd.pf, 1);
8406 * Abandon any buffered data we still wanted to send to this
8407 * channel. Receiving a CHANNEL_CLOSE is an indication that
8408 * the server really wants to get on and _destroy_ this
8409 * channel, and it isn't going to send us any further
8410 * WINDOW_ADJUSTs to permit us to send pending stuff.
8412 bufchain_clear(&c->v.v2.outbuffer);
8415 * Send outgoing EOF.
8417 sshfwd_write_eof(c);
8421 * Now process the actual close.
8423 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8424 c->closes |= CLOSES_RCVD_CLOSE;
8425 ssh2_channel_check_close(c);
8429 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8431 struct ssh_channel *c;
8433 c = ssh_channel_msg(ssh, pktin);
8436 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8437 c->remoteid = ssh_pkt_getuint32(pktin);
8438 c->halfopen = FALSE;
8439 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8440 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8442 if (c->type == CHAN_SOCKDATA) {
8443 assert(c->u.pfd.pf != NULL);
8444 pfd_confirm(c->u.pfd.pf);
8445 } else if (c->type == CHAN_ZOMBIE) {
8447 * This case can occur if a local socket error occurred
8448 * between us sending out CHANNEL_OPEN and receiving
8449 * OPEN_CONFIRMATION. In this case, all we can do is
8450 * immediately initiate close proceedings now that we know the
8451 * server's id to put in the close message.
8453 ssh2_channel_check_close(c);
8456 * We never expect to receive OPEN_CONFIRMATION for any
8457 * *other* channel type (since only local-to-remote port
8458 * forwardings cause us to send CHANNEL_OPEN after the main
8459 * channel is live - all other auxiliary channel types are
8460 * initiated from the server end). It's safe to enforce this
8461 * by assertion rather than by ssh_disconnect, because the
8462 * real point is that we never constructed a half-open channel
8463 * structure in the first place with any type other than the
8466 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8470 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8473 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8475 static const char *const reasons[] = {
8476 "<unknown reason code>",
8477 "Administratively prohibited",
8479 "Unknown channel type",
8480 "Resource shortage",
8482 unsigned reason_code;
8483 char *reason_string;
8485 struct ssh_channel *c;
8487 c = ssh_channel_msg(ssh, pktin);
8490 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8492 if (c->type == CHAN_SOCKDATA) {
8493 reason_code = ssh_pkt_getuint32(pktin);
8494 if (reason_code >= lenof(reasons))
8495 reason_code = 0; /* ensure reasons[reason_code] in range */
8496 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8497 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8498 reasons[reason_code], reason_length,
8499 NULLTOEMPTY(reason_string));
8501 pfd_close(c->u.pfd.pf);
8502 } else if (c->type == CHAN_ZOMBIE) {
8504 * This case can occur if a local socket error occurred
8505 * between us sending out CHANNEL_OPEN and receiving
8506 * OPEN_FAILURE. In this case, we need do nothing except allow
8507 * the code below to throw the half-open channel away.
8511 * We never expect to receive OPEN_FAILURE for any *other*
8512 * channel type (since only local-to-remote port forwardings
8513 * cause us to send CHANNEL_OPEN after the main channel is
8514 * live - all other auxiliary channel types are initiated from
8515 * the server end). It's safe to enforce this by assertion
8516 * rather than by ssh_disconnect, because the real point is
8517 * that we never constructed a half-open channel structure in
8518 * the first place with any type other than the above.
8520 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8523 del234(ssh->channels, c);
8527 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8530 int typelen, want_reply;
8531 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8532 struct ssh_channel *c;
8533 struct Packet *pktout;
8535 c = ssh_channel_msg(ssh, pktin);
8538 ssh_pkt_getstring(pktin, &type, &typelen);
8539 want_reply = ssh2_pkt_getbool(pktin);
8541 if (c->closes & CLOSES_SENT_CLOSE) {
8543 * We don't reply to channel requests after we've sent
8544 * CHANNEL_CLOSE for the channel, because our reply might
8545 * cross in the network with the other side's CHANNEL_CLOSE
8546 * and arrive after they have wound the channel up completely.
8552 * Having got the channel number, we now look at
8553 * the request type string to see if it's something
8556 if (c == ssh->mainchan) {
8558 * We recognise "exit-status" and "exit-signal" on
8559 * the primary channel.
8561 if (typelen == 11 &&
8562 !memcmp(type, "exit-status", 11)) {
8564 ssh->exitcode = ssh_pkt_getuint32(pktin);
8565 logeventf(ssh, "Server sent command exit status %d",
8567 reply = SSH2_MSG_CHANNEL_SUCCESS;
8569 } else if (typelen == 11 &&
8570 !memcmp(type, "exit-signal", 11)) {
8572 int is_plausible = TRUE, is_int = FALSE;
8573 char *fmt_sig = NULL, *fmt_msg = NULL;
8575 int msglen = 0, core = FALSE;
8576 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8577 * provide an `int' for the signal, despite its
8578 * having been a `string' in the drafts of RFC 4254 since at
8579 * least 2001. (Fixed in session.c 1.147.) Try to
8580 * infer which we can safely parse it as. */
8582 unsigned char *p = pktin->body +
8584 long len = pktin->length - pktin->savedpos;
8585 unsigned long num = GET_32BIT(p); /* what is it? */
8586 /* If it's 0, it hardly matters; assume string */
8590 int maybe_int = FALSE, maybe_str = FALSE;
8591 #define CHECK_HYPOTHESIS(offset, result) \
8594 int q = toint(offset); \
8595 if (q >= 0 && q+4 <= len) { \
8596 q = toint(q + 4 + GET_32BIT(p+q)); \
8597 if (q >= 0 && q+4 <= len && \
8598 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8603 CHECK_HYPOTHESIS(4+1, maybe_int);
8604 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8605 #undef CHECK_HYPOTHESIS
8606 if (maybe_int && !maybe_str)
8608 else if (!maybe_int && maybe_str)
8611 /* Crikey. Either or neither. Panic. */
8612 is_plausible = FALSE;
8615 ssh->exitcode = 128; /* means `unknown signal' */
8618 /* Old non-standard OpenSSH. */
8619 int signum = ssh_pkt_getuint32(pktin);
8620 fmt_sig = dupprintf(" %d", signum);
8621 ssh->exitcode = 128 + signum;
8623 /* As per RFC 4254. */
8626 ssh_pkt_getstring(pktin, &sig, &siglen);
8627 /* Signal name isn't supposed to be blank, but
8628 * let's cope gracefully if it is. */
8630 fmt_sig = dupprintf(" \"%.*s\"",
8635 * Really hideous method of translating the
8636 * signal description back into a locally
8637 * meaningful number.
8642 #define TRANSLATE_SIGNAL(s) \
8643 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8644 ssh->exitcode = 128 + SIG ## s
8646 TRANSLATE_SIGNAL(ABRT);
8649 TRANSLATE_SIGNAL(ALRM);
8652 TRANSLATE_SIGNAL(FPE);
8655 TRANSLATE_SIGNAL(HUP);
8658 TRANSLATE_SIGNAL(ILL);
8661 TRANSLATE_SIGNAL(INT);
8664 TRANSLATE_SIGNAL(KILL);
8667 TRANSLATE_SIGNAL(PIPE);
8670 TRANSLATE_SIGNAL(QUIT);
8673 TRANSLATE_SIGNAL(SEGV);
8676 TRANSLATE_SIGNAL(TERM);
8679 TRANSLATE_SIGNAL(USR1);
8682 TRANSLATE_SIGNAL(USR2);
8684 #undef TRANSLATE_SIGNAL
8686 ssh->exitcode = 128;
8688 core = ssh2_pkt_getbool(pktin);
8689 ssh_pkt_getstring(pktin, &msg, &msglen);
8691 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8693 /* ignore lang tag */
8694 } /* else don't attempt to parse */
8695 logeventf(ssh, "Server exited on signal%s%s%s",
8696 fmt_sig ? fmt_sig : "",
8697 core ? " (core dumped)" : "",
8698 fmt_msg ? fmt_msg : "");
8701 reply = SSH2_MSG_CHANNEL_SUCCESS;
8706 * This is a channel request we don't know
8707 * about, so we now either ignore the request
8708 * or respond with CHANNEL_FAILURE, depending
8711 reply = SSH2_MSG_CHANNEL_FAILURE;
8714 pktout = ssh2_pkt_init(reply);
8715 ssh2_pkt_adduint32(pktout, c->remoteid);
8716 ssh2_pkt_send(ssh, pktout);
8720 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8723 int typelen, want_reply;
8724 struct Packet *pktout;
8726 ssh_pkt_getstring(pktin, &type, &typelen);
8727 want_reply = ssh2_pkt_getbool(pktin);
8730 * We currently don't support any global requests
8731 * at all, so we either ignore the request or
8732 * respond with REQUEST_FAILURE, depending on
8736 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8737 ssh2_pkt_send(ssh, pktout);
8741 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8745 struct X11FakeAuth *auth;
8748 * Make up a new set of fake X11 auth data, and add it to the tree
8749 * of currently valid ones with an indication of the sharing
8750 * context that it's relevant to.
8752 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8753 auth->share_cs = share_cs;
8754 auth->share_chan = share_chan;
8759 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8761 del234(ssh->x11authtree, auth);
8762 x11_free_fake_auth(auth);
8765 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8772 const char *error = NULL;
8773 struct ssh_channel *c;
8774 unsigned remid, winsize, pktsize;
8775 unsigned our_winsize_override = 0;
8776 struct Packet *pktout;
8778 ssh_pkt_getstring(pktin, &type, &typelen);
8779 c = snew(struct ssh_channel);
8782 remid = ssh_pkt_getuint32(pktin);
8783 winsize = ssh_pkt_getuint32(pktin);
8784 pktsize = ssh_pkt_getuint32(pktin);
8786 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8789 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8790 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8791 peerport = ssh_pkt_getuint32(pktin);
8793 logeventf(ssh, "Received X11 connect request from %s:%d",
8796 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8797 error = "X11 forwarding is not enabled";
8799 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8802 c->u.x11.initial = TRUE;
8805 * If we are a connection-sharing upstream, then we should
8806 * initially present a very small window, adequate to take
8807 * the X11 initial authorisation packet but not much more.
8808 * Downstream will then present us a larger window (by
8809 * fiat of the connection-sharing protocol) and we can
8810 * guarantee to send a positive-valued WINDOW_ADJUST.
8813 our_winsize_override = 128;
8815 logevent("Opened X11 forward channel");
8819 } else if (typelen == 15 &&
8820 !memcmp(type, "forwarded-tcpip", 15)) {
8821 struct ssh_rportfwd pf, *realpf;
8824 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8825 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8826 pf.sport = ssh_pkt_getuint32(pktin);
8827 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8828 peerport = ssh_pkt_getuint32(pktin);
8829 realpf = find234(ssh->rportfwds, &pf, NULL);
8830 logeventf(ssh, "Received remote port %s:%d open request "
8831 "from %.*s:%d", pf.shost, pf.sport,
8832 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8835 if (realpf == NULL) {
8836 error = "Remote port is not recognised";
8840 if (realpf->share_ctx) {
8842 * This port forwarding is on behalf of a
8843 * connection-sharing downstream, so abandon our own
8844 * channel-open procedure and just pass the message on
8847 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8848 pktin->body, pktin->length);
8853 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8854 c, ssh->conf, realpf->pfrec->addressfamily);
8855 logeventf(ssh, "Attempting to forward remote port to "
8856 "%s:%d", realpf->dhost, realpf->dport);
8858 logeventf(ssh, "Port open failed: %s", err);
8860 error = "Port open failed";
8862 logevent("Forwarded port opened successfully");
8863 c->type = CHAN_SOCKDATA;
8866 } else if (typelen == 22 &&
8867 !memcmp(type, "auth-agent@openssh.com", 22)) {
8868 if (!ssh->agentfwd_enabled)
8869 error = "Agent forwarding is not enabled";
8871 c->type = CHAN_AGENT; /* identify channel type */
8872 bufchain_init(&c->u.a.inbuffer);
8873 c->u.a.pending = NULL;
8876 error = "Unsupported channel type requested";
8879 c->remoteid = remid;
8880 c->halfopen = FALSE;
8882 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8883 ssh2_pkt_adduint32(pktout, c->remoteid);
8884 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8885 ssh2_pkt_addstring(pktout, error);
8886 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8887 ssh2_pkt_send(ssh, pktout);
8888 logeventf(ssh, "Rejected channel open: %s", error);
8891 ssh_channel_init(c);
8892 c->v.v2.remwindow = winsize;
8893 c->v.v2.remmaxpkt = pktsize;
8894 if (our_winsize_override) {
8895 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8896 our_winsize_override;
8898 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8899 ssh2_pkt_adduint32(pktout, c->remoteid);
8900 ssh2_pkt_adduint32(pktout, c->localid);
8901 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8902 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8903 ssh2_pkt_send(ssh, pktout);
8907 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8908 void *share_cs, void *share_chan,
8909 const char *peer_addr, int peer_port,
8910 int endian, int protomajor, int protominor,
8911 const void *initial_data, int initial_len)
8914 * This function is called when we've just discovered that an X
8915 * forwarding channel on which we'd been handling the initial auth
8916 * ourselves turns out to be destined for a connection-sharing
8917 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8918 * that we completely stop tracking windows and buffering data and
8919 * just pass more or less unmodified SSH messages back and forth.
8921 c->type = CHAN_SHARING;
8922 c->u.sharing.ctx = share_cs;
8923 share_setup_x11_channel(share_cs, share_chan,
8924 c->localid, c->remoteid, c->v.v2.remwindow,
8925 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8926 peer_addr, peer_port, endian,
8927 protomajor, protominor,
8928 initial_data, initial_len);
8931 void sshfwd_x11_is_local(struct ssh_channel *c)
8934 * This function is called when we've just discovered that an X
8935 * forwarding channel is _not_ destined for a connection-sharing
8936 * downstream but we're going to handle it ourselves. We stop
8937 * presenting a cautiously small window and go into ordinary data
8940 c->u.x11.initial = FALSE;
8941 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8945 * Buffer banner messages for later display at some convenient point,
8946 * if we're going to display them.
8948 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8950 /* Arbitrary limit to prevent unbounded inflation of buffer */
8951 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8952 bufchain_size(&ssh->banner) <= 131072) {
8953 char *banner = NULL;
8955 ssh_pkt_getstring(pktin, &banner, &size);
8957 bufchain_add(&ssh->banner, banner, size);
8961 /* Helper function to deal with sending tty modes for "pty-req" */
8962 static void ssh2_send_ttymode(void *data,
8963 const struct ssh_ttymode *mode, char *val)
8965 struct Packet *pktout = (struct Packet *)data;
8966 unsigned int arg = 0;
8968 switch (mode->type) {
8970 arg = ssh_tty_parse_specchar(val);
8973 arg = ssh_tty_parse_boolean(val);
8976 ssh2_pkt_addbyte(pktout, mode->opcode);
8977 ssh2_pkt_adduint32(pktout, arg);
8980 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8983 struct ssh2_setup_x11_state {
8987 struct Packet *pktout;
8988 crStateP(ssh2_setup_x11_state, ctx);
8992 logevent("Requesting X11 forwarding");
8993 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8995 ssh2_pkt_addbool(pktout, 0); /* many connections */
8996 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8997 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8998 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8999 ssh2_pkt_send(ssh, pktout);
9001 /* Wait to be called back with either a response packet, or NULL
9002 * meaning clean up and free our data */
9006 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9007 logevent("X11 forwarding enabled");
9008 ssh->X11_fwd_enabled = TRUE;
9010 logevent("X11 forwarding refused");
9016 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
9019 struct ssh2_setup_agent_state {
9023 struct Packet *pktout;
9024 crStateP(ssh2_setup_agent_state, ctx);
9028 logevent("Requesting OpenSSH-style agent forwarding");
9029 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
9030 ssh2_setup_agent, s);
9031 ssh2_pkt_send(ssh, pktout);
9033 /* Wait to be called back with either a response packet, or NULL
9034 * meaning clean up and free our data */
9038 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9039 logevent("Agent forwarding enabled");
9040 ssh->agentfwd_enabled = TRUE;
9042 logevent("Agent forwarding refused");
9048 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
9051 struct ssh2_setup_pty_state {
9055 struct Packet *pktout;
9056 crStateP(ssh2_setup_pty_state, ctx);
9060 /* Unpick the terminal-speed string. */
9061 /* XXX perhaps we should allow no speeds to be sent. */
9062 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9063 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9064 /* Build the pty request. */
9065 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9067 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9068 ssh2_pkt_adduint32(pktout, ssh->term_width);
9069 ssh2_pkt_adduint32(pktout, ssh->term_height);
9070 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9071 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9072 ssh2_pkt_addstring_start(pktout);
9073 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9074 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9075 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9076 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9077 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9078 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9079 ssh2_pkt_send(ssh, pktout);
9080 ssh->state = SSH_STATE_INTERMED;
9082 /* Wait to be called back with either a response packet, or NULL
9083 * meaning clean up and free our data */
9087 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9088 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9089 ssh->ospeed, ssh->ispeed);
9090 ssh->got_pty = TRUE;
9092 c_write_str(ssh, "Server refused to allocate pty\r\n");
9093 ssh->editing = ssh->echoing = 1;
9100 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9103 struct ssh2_setup_env_state {
9105 int num_env, env_left, env_ok;
9108 struct Packet *pktout;
9109 crStateP(ssh2_setup_env_state, ctx);
9114 * Send environment variables.
9116 * Simplest thing here is to send all the requests at once, and
9117 * then wait for a whole bunch of successes or failures.
9123 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9125 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9126 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9127 ssh2_pkt_addstring(pktout, key);
9128 ssh2_pkt_addstring(pktout, val);
9129 ssh2_pkt_send(ssh, pktout);
9134 logeventf(ssh, "Sent %d environment variables", s->num_env);
9139 s->env_left = s->num_env;
9141 while (s->env_left > 0) {
9142 /* Wait to be called back with either a response packet,
9143 * or NULL meaning clean up and free our data */
9145 if (!pktin) goto out;
9146 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9151 if (s->env_ok == s->num_env) {
9152 logevent("All environment variables successfully set");
9153 } else if (s->env_ok == 0) {
9154 logevent("All environment variables refused");
9155 c_write_str(ssh, "Server refused to set environment variables\r\n");
9157 logeventf(ssh, "%d environment variables refused",
9158 s->num_env - s->env_ok);
9159 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9167 * Handle the SSH-2 userauth and connection layers.
9169 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9171 do_ssh2_authconn(ssh, NULL, 0, pktin);
9174 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9178 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9181 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9182 struct Packet *pktin)
9184 struct do_ssh2_authconn_state {
9188 AUTH_TYPE_PUBLICKEY,
9189 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9190 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9192 AUTH_TYPE_GSSAPI, /* always QUIET */
9193 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9194 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9196 int done_service_req;
9197 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9198 int tried_pubkey_config, done_agent;
9203 int kbd_inter_refused;
9204 int we_are_in, userauth_success;
9205 prompts_t *cur_prompt;
9210 void *publickey_blob;
9211 int publickey_bloblen;
9212 int privatekey_available, privatekey_encrypted;
9213 char *publickey_algorithm;
9214 char *publickey_comment;
9215 unsigned char agent_request[5], *agent_response, *agentp;
9216 int agent_responselen;
9217 unsigned char *pkblob_in_agent;
9219 char *pkblob, *alg, *commentp;
9220 int pklen, alglen, commentlen;
9221 int siglen, retlen, len;
9222 char *q, *agentreq, *ret;
9223 struct Packet *pktout;
9226 struct ssh_gss_library *gsslib;
9227 Ssh_gss_ctx gss_ctx;
9228 Ssh_gss_buf gss_buf;
9229 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9230 Ssh_gss_name gss_srv_name;
9231 Ssh_gss_stat gss_stat;
9234 crState(do_ssh2_authconn_state);
9238 /* Register as a handler for all the messages this coroutine handles. */
9239 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9240 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9241 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9242 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9243 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9244 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9245 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9246 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9247 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9248 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9249 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9250 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9251 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9252 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9253 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9254 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9255 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9256 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9257 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9258 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9260 s->done_service_req = FALSE;
9261 s->we_are_in = s->userauth_success = FALSE;
9262 s->agent_response = NULL;
9264 s->tried_gssapi = FALSE;
9267 if (!ssh->bare_connection) {
9268 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9270 * Request userauth protocol, and await a response to it.
9272 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9273 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9274 ssh2_pkt_send(ssh, s->pktout);
9275 crWaitUntilV(pktin);
9276 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9277 s->done_service_req = TRUE;
9279 if (!s->done_service_req) {
9281 * Request connection protocol directly, without authentication.
9283 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9284 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9285 ssh2_pkt_send(ssh, s->pktout);
9286 crWaitUntilV(pktin);
9287 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9288 s->we_are_in = TRUE; /* no auth required */
9290 bombout(("Server refused service request"));
9295 s->we_are_in = TRUE;
9298 /* Arrange to be able to deal with any BANNERs that come in.
9299 * (We do this now as packets may come in during the next bit.) */
9300 bufchain_init(&ssh->banner);
9301 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9302 ssh2_msg_userauth_banner;
9305 * Misc one-time setup for authentication.
9307 s->publickey_blob = NULL;
9308 if (!s->we_are_in) {
9311 * Load the public half of any configured public key file
9314 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9315 if (!filename_is_null(s->keyfile)) {
9317 logeventf(ssh, "Reading key file \"%.150s\"",
9318 filename_to_str(s->keyfile));
9319 keytype = key_type(s->keyfile);
9320 if (keytype == SSH_KEYTYPE_SSH2 ||
9321 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9322 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9325 ssh2_userkey_loadpub(s->keyfile,
9326 &s->publickey_algorithm,
9327 &s->publickey_bloblen,
9328 &s->publickey_comment, &error);
9329 if (s->publickey_blob) {
9330 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9331 if (!s->privatekey_available)
9332 logeventf(ssh, "Key file contains public key only");
9333 s->privatekey_encrypted =
9334 ssh2_userkey_encrypted(s->keyfile, NULL);
9337 logeventf(ssh, "Unable to load key (%s)",
9339 msgbuf = dupprintf("Unable to load key file "
9340 "\"%.150s\" (%s)\r\n",
9341 filename_to_str(s->keyfile),
9343 c_write_str(ssh, msgbuf);
9348 logeventf(ssh, "Unable to use this key file (%s)",
9349 key_type_to_str(keytype));
9350 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9352 filename_to_str(s->keyfile),
9353 key_type_to_str(keytype));
9354 c_write_str(ssh, msgbuf);
9356 s->publickey_blob = NULL;
9361 * Find out about any keys Pageant has (but if there's a
9362 * public key configured, filter out all others).
9365 s->agent_response = NULL;
9366 s->pkblob_in_agent = NULL;
9367 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9371 logevent("Pageant is running. Requesting keys.");
9373 /* Request the keys held by the agent. */
9374 PUT_32BIT(s->agent_request, 1);
9375 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9376 ssh->auth_agent_query = agent_query(
9377 s->agent_request, 5, &r, &s->agent_responselen,
9378 ssh_agent_callback, ssh);
9379 if (ssh->auth_agent_query) {
9383 bombout(("Unexpected data from server while"
9384 " waiting for agent response"));
9387 } while (pktin || inlen > 0);
9388 r = ssh->agent_response;
9389 s->agent_responselen = ssh->agent_response_len;
9391 s->agent_response = (unsigned char *) r;
9392 if (s->agent_response && s->agent_responselen >= 5 &&
9393 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9396 p = s->agent_response + 5;
9397 s->nkeys = toint(GET_32BIT(p));
9400 * Vet the Pageant response to ensure that the key
9401 * count and blob lengths make sense.
9404 logeventf(ssh, "Pageant response contained a negative"
9405 " key count %d", s->nkeys);
9407 goto done_agent_query;
9409 unsigned char *q = p + 4;
9410 int lenleft = s->agent_responselen - 5 - 4;
9412 for (keyi = 0; keyi < s->nkeys; keyi++) {
9413 int bloblen, commentlen;
9415 logeventf(ssh, "Pageant response was truncated");
9417 goto done_agent_query;
9419 bloblen = toint(GET_32BIT(q));
9420 if (bloblen < 0 || bloblen > lenleft) {
9421 logeventf(ssh, "Pageant response was truncated");
9423 goto done_agent_query;
9425 lenleft -= 4 + bloblen;
9427 commentlen = toint(GET_32BIT(q));
9428 if (commentlen < 0 || commentlen > lenleft) {
9429 logeventf(ssh, "Pageant response was truncated");
9431 goto done_agent_query;
9433 lenleft -= 4 + commentlen;
9434 q += 4 + commentlen;
9439 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9440 if (s->publickey_blob) {
9441 /* See if configured key is in agent. */
9442 for (keyi = 0; keyi < s->nkeys; keyi++) {
9443 s->pklen = toint(GET_32BIT(p));
9444 if (s->pklen == s->publickey_bloblen &&
9445 !memcmp(p+4, s->publickey_blob,
9446 s->publickey_bloblen)) {
9447 logeventf(ssh, "Pageant key #%d matches "
9448 "configured key file", keyi);
9450 s->pkblob_in_agent = p;
9454 p += toint(GET_32BIT(p)) + 4; /* comment */
9456 if (!s->pkblob_in_agent) {
9457 logevent("Configured key file not in Pageant");
9462 logevent("Failed to get reply from Pageant");
9470 * We repeat this whole loop, including the username prompt,
9471 * until we manage a successful authentication. If the user
9472 * types the wrong _password_, they can be sent back to the
9473 * beginning to try another username, if this is configured on.
9474 * (If they specify a username in the config, they are never
9475 * asked, even if they do give a wrong password.)
9477 * I think this best serves the needs of
9479 * - the people who have no configuration, no keys, and just
9480 * want to try repeated (username,password) pairs until they
9481 * type both correctly
9483 * - people who have keys and configuration but occasionally
9484 * need to fall back to passwords
9486 * - people with a key held in Pageant, who might not have
9487 * logged in to a particular machine before; so they want to
9488 * type a username, and then _either_ their key will be
9489 * accepted, _or_ they will type a password. If they mistype
9490 * the username they will want to be able to get back and
9493 s->got_username = FALSE;
9494 while (!s->we_are_in) {
9498 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9500 * We got a username last time round this loop, and
9501 * with change_username turned off we don't try to get
9504 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9505 int ret; /* need not be kept over crReturn */
9506 s->cur_prompt = new_prompts(ssh->frontend);
9507 s->cur_prompt->to_server = TRUE;
9508 s->cur_prompt->name = dupstr("SSH login name");
9509 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9510 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9513 crWaitUntilV(!pktin);
9514 ret = get_userpass_input(s->cur_prompt, in, inlen);
9519 * get_userpass_input() failed to get a username.
9522 free_prompts(s->cur_prompt);
9523 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9526 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9527 free_prompts(s->cur_prompt);
9530 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9531 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9532 c_write_str(ssh, stuff);
9536 s->got_username = TRUE;
9539 * Send an authentication request using method "none": (a)
9540 * just in case it succeeds, and (b) so that we know what
9541 * authentication methods we can usefully try next.
9543 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9545 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9546 ssh2_pkt_addstring(s->pktout, ssh->username);
9547 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9548 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9549 ssh2_pkt_send(ssh, s->pktout);
9550 s->type = AUTH_TYPE_NONE;
9552 s->we_are_in = FALSE;
9554 s->tried_pubkey_config = FALSE;
9555 s->kbd_inter_refused = FALSE;
9557 /* Reset agent request state. */
9558 s->done_agent = FALSE;
9559 if (s->agent_response) {
9560 if (s->pkblob_in_agent) {
9561 s->agentp = s->pkblob_in_agent;
9563 s->agentp = s->agent_response + 5 + 4;
9569 char *methods = NULL;
9573 * Wait for the result of the last authentication request.
9576 crWaitUntilV(pktin);
9578 * Now is a convenient point to spew any banner material
9579 * that we've accumulated. (This should ensure that when
9580 * we exit the auth loop, we haven't any left to deal
9584 int size = bufchain_size(&ssh->banner);
9586 * Don't show the banner if we're operating in
9587 * non-verbose non-interactive mode. (It's probably
9588 * a script, which means nobody will read the
9589 * banner _anyway_, and moreover the printing of
9590 * the banner will screw up processing on the
9591 * output of (say) plink.)
9593 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9594 char *banner = snewn(size, char);
9595 bufchain_fetch(&ssh->banner, banner, size);
9596 c_write_untrusted(ssh, banner, size);
9599 bufchain_clear(&ssh->banner);
9601 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9602 logevent("Access granted");
9603 s->we_are_in = s->userauth_success = TRUE;
9607 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9608 bombout(("Strange packet received during authentication: "
9609 "type %d", pktin->type));
9616 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9617 * we can look at the string in it and know what we can
9618 * helpfully try next.
9620 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9621 ssh_pkt_getstring(pktin, &methods, &methlen);
9622 if (!ssh2_pkt_getbool(pktin)) {
9624 * We have received an unequivocal Access
9625 * Denied. This can translate to a variety of
9626 * messages, or no message at all.
9628 * For forms of authentication which are attempted
9629 * implicitly, by which I mean without printing
9630 * anything in the window indicating that we're
9631 * trying them, we should never print 'Access
9634 * If we do print a message saying that we're
9635 * attempting some kind of authentication, it's OK
9636 * to print a followup message saying it failed -
9637 * but the message may sometimes be more specific
9638 * than simply 'Access denied'.
9640 * Additionally, if we'd just tried password
9641 * authentication, we should break out of this
9642 * whole loop so as to go back to the username
9643 * prompt (iff we're configured to allow
9644 * username change attempts).
9646 if (s->type == AUTH_TYPE_NONE) {
9648 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9649 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9650 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9651 c_write_str(ssh, "Server refused our key\r\n");
9652 logevent("Server refused our key");
9653 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9654 /* This _shouldn't_ happen except by a
9655 * protocol bug causing client and server to
9656 * disagree on what is a correct signature. */
9657 c_write_str(ssh, "Server refused public-key signature"
9658 " despite accepting key!\r\n");
9659 logevent("Server refused public-key signature"
9660 " despite accepting key!");
9661 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9662 /* quiet, so no c_write */
9663 logevent("Server refused keyboard-interactive authentication");
9664 } else if (s->type==AUTH_TYPE_GSSAPI) {
9665 /* always quiet, so no c_write */
9666 /* also, the code down in the GSSAPI block has
9667 * already logged this in the Event Log */
9668 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9669 logevent("Keyboard-interactive authentication failed");
9670 c_write_str(ssh, "Access denied\r\n");
9672 assert(s->type == AUTH_TYPE_PASSWORD);
9673 logevent("Password authentication failed");
9674 c_write_str(ssh, "Access denied\r\n");
9676 if (conf_get_int(ssh->conf, CONF_change_username)) {
9677 /* XXX perhaps we should allow
9678 * keyboard-interactive to do this too? */
9679 s->we_are_in = FALSE;
9684 c_write_str(ssh, "Further authentication required\r\n");
9685 logevent("Further authentication required");
9689 in_commasep_string("publickey", methods, methlen);
9691 in_commasep_string("password", methods, methlen);
9692 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9693 in_commasep_string("keyboard-interactive", methods, methlen);
9695 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9696 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9697 /* Try loading the GSS libraries and see if we
9700 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9701 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9703 /* No point in even bothering to try to load the
9704 * GSS libraries, if the user configuration and
9705 * server aren't both prepared to attempt GSSAPI
9706 * auth in the first place. */
9707 s->can_gssapi = FALSE;
9712 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9714 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9717 * Attempt public-key authentication using a key from Pageant.
9720 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9722 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9724 /* Unpack key from agent response */
9725 s->pklen = toint(GET_32BIT(s->agentp));
9727 s->pkblob = (char *)s->agentp;
9728 s->agentp += s->pklen;
9729 s->alglen = toint(GET_32BIT(s->pkblob));
9730 s->alg = s->pkblob + 4;
9731 s->commentlen = toint(GET_32BIT(s->agentp));
9733 s->commentp = (char *)s->agentp;
9734 s->agentp += s->commentlen;
9735 /* s->agentp now points at next key, if any */
9737 /* See if server will accept it */
9738 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9739 ssh2_pkt_addstring(s->pktout, ssh->username);
9740 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9741 /* service requested */
9742 ssh2_pkt_addstring(s->pktout, "publickey");
9744 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9745 ssh2_pkt_addstring_start(s->pktout);
9746 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9747 ssh2_pkt_addstring_start(s->pktout);
9748 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9749 ssh2_pkt_send(ssh, s->pktout);
9750 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9752 crWaitUntilV(pktin);
9753 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9755 /* Offer of key refused. */
9762 if (flags & FLAG_VERBOSE) {
9763 c_write_str(ssh, "Authenticating with "
9765 c_write(ssh, s->commentp, s->commentlen);
9766 c_write_str(ssh, "\" from agent\r\n");
9770 * Server is willing to accept the key.
9771 * Construct a SIGN_REQUEST.
9773 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9774 ssh2_pkt_addstring(s->pktout, ssh->username);
9775 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9776 /* service requested */
9777 ssh2_pkt_addstring(s->pktout, "publickey");
9779 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9780 ssh2_pkt_addstring_start(s->pktout);
9781 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9782 ssh2_pkt_addstring_start(s->pktout);
9783 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9785 /* Ask agent for signature. */
9786 s->siglen = s->pktout->length - 5 + 4 +
9787 ssh->v2_session_id_len;
9788 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9790 s->len = 1; /* message type */
9791 s->len += 4 + s->pklen; /* key blob */
9792 s->len += 4 + s->siglen; /* data to sign */
9793 s->len += 4; /* flags */
9794 s->agentreq = snewn(4 + s->len, char);
9795 PUT_32BIT(s->agentreq, s->len);
9796 s->q = s->agentreq + 4;
9797 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9798 PUT_32BIT(s->q, s->pklen);
9800 memcpy(s->q, s->pkblob, s->pklen);
9802 PUT_32BIT(s->q, s->siglen);
9804 /* Now the data to be signed... */
9805 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9806 PUT_32BIT(s->q, ssh->v2_session_id_len);
9809 memcpy(s->q, ssh->v2_session_id,
9810 ssh->v2_session_id_len);
9811 s->q += ssh->v2_session_id_len;
9812 memcpy(s->q, s->pktout->data + 5,
9813 s->pktout->length - 5);
9814 s->q += s->pktout->length - 5;
9815 /* And finally the (zero) flags word. */
9817 ssh->auth_agent_query = agent_query(
9818 s->agentreq, s->len + 4, &vret, &s->retlen,
9819 ssh_agent_callback, ssh);
9820 if (ssh->auth_agent_query) {
9824 bombout(("Unexpected data from server"
9825 " while waiting for agent"
9829 } while (pktin || inlen > 0);
9830 vret = ssh->agent_response;
9831 s->retlen = ssh->agent_response_len;
9836 if (s->retlen >= 9 &&
9837 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9838 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9839 logevent("Sending Pageant's response");
9840 ssh2_add_sigblob(ssh, s->pktout,
9841 s->pkblob, s->pklen,
9843 GET_32BIT(s->ret + 5));
9844 ssh2_pkt_send(ssh, s->pktout);
9845 s->type = AUTH_TYPE_PUBLICKEY;
9847 /* FIXME: less drastic response */
9848 bombout(("Pageant failed to answer challenge"));
9854 /* Do we have any keys left to try? */
9855 if (s->pkblob_in_agent) {
9856 s->done_agent = TRUE;
9857 s->tried_pubkey_config = TRUE;
9860 if (s->keyi >= s->nkeys)
9861 s->done_agent = TRUE;
9864 } else if (s->can_pubkey && s->publickey_blob &&
9865 s->privatekey_available && !s->tried_pubkey_config) {
9867 struct ssh2_userkey *key; /* not live over crReturn */
9868 char *passphrase; /* not live over crReturn */
9870 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9872 s->tried_pubkey_config = TRUE;
9875 * Try the public key supplied in the configuration.
9877 * First, offer the public blob to see if the server is
9878 * willing to accept it.
9880 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9881 ssh2_pkt_addstring(s->pktout, ssh->username);
9882 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9883 /* service requested */
9884 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9885 ssh2_pkt_addbool(s->pktout, FALSE);
9886 /* no signature included */
9887 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9888 ssh2_pkt_addstring_start(s->pktout);
9889 ssh2_pkt_addstring_data(s->pktout,
9890 (char *)s->publickey_blob,
9891 s->publickey_bloblen);
9892 ssh2_pkt_send(ssh, s->pktout);
9893 logevent("Offered public key");
9895 crWaitUntilV(pktin);
9896 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9897 /* Key refused. Give up. */
9898 s->gotit = TRUE; /* reconsider message next loop */
9899 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9900 continue; /* process this new message */
9902 logevent("Offer of public key accepted");
9905 * Actually attempt a serious authentication using
9908 if (flags & FLAG_VERBOSE) {
9909 c_write_str(ssh, "Authenticating with public key \"");
9910 c_write_str(ssh, s->publickey_comment);
9911 c_write_str(ssh, "\"\r\n");
9915 const char *error; /* not live over crReturn */
9916 if (s->privatekey_encrypted) {
9918 * Get a passphrase from the user.
9920 int ret; /* need not be kept over crReturn */
9921 s->cur_prompt = new_prompts(ssh->frontend);
9922 s->cur_prompt->to_server = FALSE;
9923 s->cur_prompt->name = dupstr("SSH key passphrase");
9924 add_prompt(s->cur_prompt,
9925 dupprintf("Passphrase for key \"%.100s\": ",
9926 s->publickey_comment),
9928 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9931 crWaitUntilV(!pktin);
9932 ret = get_userpass_input(s->cur_prompt,
9937 /* Failed to get a passphrase. Terminate. */
9938 free_prompts(s->cur_prompt);
9939 ssh_disconnect(ssh, NULL,
9940 "Unable to authenticate",
9941 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9946 dupstr(s->cur_prompt->prompts[0]->result);
9947 free_prompts(s->cur_prompt);
9949 passphrase = NULL; /* no passphrase needed */
9953 * Try decrypting the key.
9955 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9956 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9958 /* burn the evidence */
9959 smemclr(passphrase, strlen(passphrase));
9962 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9964 (key == SSH2_WRONG_PASSPHRASE)) {
9965 c_write_str(ssh, "Wrong passphrase\r\n");
9967 /* and loop again */
9969 c_write_str(ssh, "Unable to load private key (");
9970 c_write_str(ssh, error);
9971 c_write_str(ssh, ")\r\n");
9973 break; /* try something else */
9979 unsigned char *pkblob, *sigblob, *sigdata;
9980 int pkblob_len, sigblob_len, sigdata_len;
9984 * We have loaded the private key and the server
9985 * has announced that it's willing to accept it.
9986 * Hallelujah. Generate a signature and send it.
9988 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9989 ssh2_pkt_addstring(s->pktout, ssh->username);
9990 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9991 /* service requested */
9992 ssh2_pkt_addstring(s->pktout, "publickey");
9994 ssh2_pkt_addbool(s->pktout, TRUE);
9995 /* signature follows */
9996 ssh2_pkt_addstring(s->pktout, key->alg->name);
9997 pkblob = key->alg->public_blob(key->data,
9999 ssh2_pkt_addstring_start(s->pktout);
10000 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
10004 * The data to be signed is:
10006 * string session-id
10008 * followed by everything so far placed in the
10011 sigdata_len = s->pktout->length - 5 + 4 +
10012 ssh->v2_session_id_len;
10013 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
10015 sigdata = snewn(sigdata_len, unsigned char);
10017 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
10018 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
10021 memcpy(sigdata+p, ssh->v2_session_id,
10022 ssh->v2_session_id_len);
10023 p += ssh->v2_session_id_len;
10024 memcpy(sigdata+p, s->pktout->data + 5,
10025 s->pktout->length - 5);
10026 p += s->pktout->length - 5;
10027 assert(p == sigdata_len);
10028 sigblob = key->alg->sign(key->data, (char *)sigdata,
10029 sigdata_len, &sigblob_len);
10030 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
10031 sigblob, sigblob_len);
10036 ssh2_pkt_send(ssh, s->pktout);
10037 logevent("Sent public key signature");
10038 s->type = AUTH_TYPE_PUBLICKEY;
10039 key->alg->freekey(key->data);
10040 sfree(key->comment);
10045 } else if (s->can_gssapi && !s->tried_gssapi) {
10047 /* GSSAPI Authentication */
10049 int micoffset, len;
10052 s->type = AUTH_TYPE_GSSAPI;
10053 s->tried_gssapi = TRUE;
10055 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
10058 * Pick the highest GSS library on the preference
10064 for (i = 0; i < ngsslibs; i++) {
10065 int want_id = conf_get_int_int(ssh->conf,
10066 CONF_ssh_gsslist, i);
10067 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10068 if (ssh->gsslibs->libraries[j].id == want_id) {
10069 s->gsslib = &ssh->gsslibs->libraries[j];
10070 goto got_gsslib; /* double break */
10075 * We always expect to have found something in
10076 * the above loop: we only came here if there
10077 * was at least one viable GSS library, and the
10078 * preference list should always mention
10079 * everything and only change the order.
10084 if (s->gsslib->gsslogmsg)
10085 logevent(s->gsslib->gsslogmsg);
10087 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10088 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10089 ssh2_pkt_addstring(s->pktout, ssh->username);
10090 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10091 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10092 logevent("Attempting GSSAPI authentication");
10094 /* add mechanism info */
10095 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10097 /* number of GSSAPI mechanisms */
10098 ssh2_pkt_adduint32(s->pktout,1);
10100 /* length of OID + 2 */
10101 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10102 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10104 /* length of OID */
10105 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10107 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10108 s->gss_buf.length);
10109 ssh2_pkt_send(ssh, s->pktout);
10110 crWaitUntilV(pktin);
10111 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10112 logevent("GSSAPI authentication request refused");
10116 /* check returned packet ... */
10118 ssh_pkt_getstring(pktin, &data, &len);
10119 s->gss_rcvtok.value = data;
10120 s->gss_rcvtok.length = len;
10121 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10122 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10123 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10124 memcmp((char *)s->gss_rcvtok.value + 2,
10125 s->gss_buf.value,s->gss_buf.length) ) {
10126 logevent("GSSAPI authentication - wrong response from server");
10130 /* now start running */
10131 s->gss_stat = s->gsslib->import_name(s->gsslib,
10134 if (s->gss_stat != SSH_GSS_OK) {
10135 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10136 logevent("GSSAPI import name failed - Bad service name");
10138 logevent("GSSAPI import name failed");
10142 /* fetch TGT into GSS engine */
10143 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10145 if (s->gss_stat != SSH_GSS_OK) {
10146 logevent("GSSAPI authentication failed to get credentials");
10147 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10151 /* initial tokens are empty */
10152 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10153 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10155 /* now enter the loop */
10157 s->gss_stat = s->gsslib->init_sec_context
10161 conf_get_int(ssh->conf, CONF_gssapifwd),
10165 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10166 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10167 logevent("GSSAPI authentication initialisation failed");
10169 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10170 &s->gss_buf) == SSH_GSS_OK) {
10171 logevent(s->gss_buf.value);
10172 sfree(s->gss_buf.value);
10177 logevent("GSSAPI authentication initialised");
10179 /* Client and server now exchange tokens until GSSAPI
10180 * no longer says CONTINUE_NEEDED */
10182 if (s->gss_sndtok.length != 0) {
10183 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10184 ssh_pkt_addstring_start(s->pktout);
10185 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10186 ssh2_pkt_send(ssh, s->pktout);
10187 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10190 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10191 crWaitUntilV(pktin);
10192 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10193 logevent("GSSAPI authentication - bad server response");
10194 s->gss_stat = SSH_GSS_FAILURE;
10197 ssh_pkt_getstring(pktin, &data, &len);
10198 s->gss_rcvtok.value = data;
10199 s->gss_rcvtok.length = len;
10201 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10203 if (s->gss_stat != SSH_GSS_OK) {
10204 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10205 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10208 logevent("GSSAPI authentication loop finished OK");
10210 /* Now send the MIC */
10212 s->pktout = ssh2_pkt_init(0);
10213 micoffset = s->pktout->length;
10214 ssh_pkt_addstring_start(s->pktout);
10215 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10216 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10217 ssh_pkt_addstring(s->pktout, ssh->username);
10218 ssh_pkt_addstring(s->pktout, "ssh-connection");
10219 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10221 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10222 s->gss_buf.length = s->pktout->length - micoffset;
10224 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10225 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10226 ssh_pkt_addstring_start(s->pktout);
10227 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10228 ssh2_pkt_send(ssh, s->pktout);
10229 s->gsslib->free_mic(s->gsslib, &mic);
10233 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10234 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10237 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10240 * Keyboard-interactive authentication.
10243 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10245 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10247 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10248 ssh2_pkt_addstring(s->pktout, ssh->username);
10249 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10250 /* service requested */
10251 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10253 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10254 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10255 ssh2_pkt_send(ssh, s->pktout);
10257 logevent("Attempting keyboard-interactive authentication");
10259 crWaitUntilV(pktin);
10260 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10261 /* Server is not willing to do keyboard-interactive
10262 * at all (or, bizarrely but legally, accepts the
10263 * user without actually issuing any prompts).
10264 * Give up on it entirely. */
10266 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10267 s->kbd_inter_refused = TRUE; /* don't try it again */
10272 * Loop while the server continues to send INFO_REQUESTs.
10274 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10276 char *name, *inst, *lang;
10277 int name_len, inst_len, lang_len;
10281 * We've got a fresh USERAUTH_INFO_REQUEST.
10282 * Get the preamble and start building a prompt.
10284 ssh_pkt_getstring(pktin, &name, &name_len);
10285 ssh_pkt_getstring(pktin, &inst, &inst_len);
10286 ssh_pkt_getstring(pktin, &lang, &lang_len);
10287 s->cur_prompt = new_prompts(ssh->frontend);
10288 s->cur_prompt->to_server = TRUE;
10291 * Get any prompt(s) from the packet.
10293 s->num_prompts = ssh_pkt_getuint32(pktin);
10294 for (i = 0; i < s->num_prompts; i++) {
10298 static char noprompt[] =
10299 "<server failed to send prompt>: ";
10301 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10302 echo = ssh2_pkt_getbool(pktin);
10305 prompt_len = lenof(noprompt)-1;
10307 add_prompt(s->cur_prompt,
10308 dupprintf("%.*s", prompt_len, prompt),
10313 /* FIXME: better prefix to distinguish from
10314 * local prompts? */
10315 s->cur_prompt->name =
10316 dupprintf("SSH server: %.*s", name_len, name);
10317 s->cur_prompt->name_reqd = TRUE;
10319 s->cur_prompt->name =
10320 dupstr("SSH server authentication");
10321 s->cur_prompt->name_reqd = FALSE;
10323 /* We add a prefix to try to make it clear that a prompt
10324 * has come from the server.
10325 * FIXME: ugly to print "Using..." in prompt _every_
10326 * time round. Can this be done more subtly? */
10327 /* Special case: for reasons best known to themselves,
10328 * some servers send k-i requests with no prompts and
10329 * nothing to display. Keep quiet in this case. */
10330 if (s->num_prompts || name_len || inst_len) {
10331 s->cur_prompt->instruction =
10332 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10333 inst_len ? "\n" : "", inst_len, inst);
10334 s->cur_prompt->instr_reqd = TRUE;
10336 s->cur_prompt->instr_reqd = FALSE;
10340 * Display any instructions, and get the user's
10344 int ret; /* not live over crReturn */
10345 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10348 crWaitUntilV(!pktin);
10349 ret = get_userpass_input(s->cur_prompt, in, inlen);
10354 * Failed to get responses. Terminate.
10356 free_prompts(s->cur_prompt);
10357 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10358 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10365 * Send the response(s) to the server.
10367 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10368 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10369 for (i=0; i < s->num_prompts; i++) {
10370 ssh2_pkt_addstring(s->pktout,
10371 s->cur_prompt->prompts[i]->result);
10373 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10376 * Free the prompts structure from this iteration.
10377 * If there's another, a new one will be allocated
10378 * when we return to the top of this while loop.
10380 free_prompts(s->cur_prompt);
10383 * Get the next packet in case it's another
10386 crWaitUntilV(pktin);
10391 * We should have SUCCESS or FAILURE now.
10395 } else if (s->can_passwd) {
10398 * Plain old password authentication.
10400 int ret; /* not live over crReturn */
10401 int changereq_first_time; /* not live over crReturn */
10403 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10405 s->cur_prompt = new_prompts(ssh->frontend);
10406 s->cur_prompt->to_server = TRUE;
10407 s->cur_prompt->name = dupstr("SSH password");
10408 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10413 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10416 crWaitUntilV(!pktin);
10417 ret = get_userpass_input(s->cur_prompt, in, inlen);
10422 * Failed to get responses. Terminate.
10424 free_prompts(s->cur_prompt);
10425 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10426 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10431 * Squirrel away the password. (We may need it later if
10432 * asked to change it.)
10434 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10435 free_prompts(s->cur_prompt);
10438 * Send the password packet.
10440 * We pad out the password packet to 256 bytes to make
10441 * it harder for an attacker to find the length of the
10444 * Anyone using a password longer than 256 bytes
10445 * probably doesn't have much to worry about from
10446 * people who find out how long their password is!
10448 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10449 ssh2_pkt_addstring(s->pktout, ssh->username);
10450 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10451 /* service requested */
10452 ssh2_pkt_addstring(s->pktout, "password");
10453 ssh2_pkt_addbool(s->pktout, FALSE);
10454 ssh2_pkt_addstring(s->pktout, s->password);
10455 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10456 logevent("Sent password");
10457 s->type = AUTH_TYPE_PASSWORD;
10460 * Wait for next packet, in case it's a password change
10463 crWaitUntilV(pktin);
10464 changereq_first_time = TRUE;
10466 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10469 * We're being asked for a new password
10470 * (perhaps not for the first time).
10471 * Loop until the server accepts it.
10474 int got_new = FALSE; /* not live over crReturn */
10475 char *prompt; /* not live over crReturn */
10476 int prompt_len; /* not live over crReturn */
10480 if (changereq_first_time)
10481 msg = "Server requested password change";
10483 msg = "Server rejected new password";
10485 c_write_str(ssh, msg);
10486 c_write_str(ssh, "\r\n");
10489 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10491 s->cur_prompt = new_prompts(ssh->frontend);
10492 s->cur_prompt->to_server = TRUE;
10493 s->cur_prompt->name = dupstr("New SSH password");
10494 s->cur_prompt->instruction =
10495 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10496 s->cur_prompt->instr_reqd = TRUE;
10498 * There's no explicit requirement in the protocol
10499 * for the "old" passwords in the original and
10500 * password-change messages to be the same, and
10501 * apparently some Cisco kit supports password change
10502 * by the user entering a blank password originally
10503 * and the real password subsequently, so,
10504 * reluctantly, we prompt for the old password again.
10506 * (On the other hand, some servers don't even bother
10507 * to check this field.)
10509 add_prompt(s->cur_prompt,
10510 dupstr("Current password (blank for previously entered password): "),
10512 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10514 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10518 * Loop until the user manages to enter the same
10523 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10526 crWaitUntilV(!pktin);
10527 ret = get_userpass_input(s->cur_prompt, in, inlen);
10532 * Failed to get responses. Terminate.
10534 /* burn the evidence */
10535 free_prompts(s->cur_prompt);
10536 smemclr(s->password, strlen(s->password));
10537 sfree(s->password);
10538 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10539 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10545 * If the user specified a new original password
10546 * (IYSWIM), overwrite any previously specified
10548 * (A side effect is that the user doesn't have to
10549 * re-enter it if they louse up the new password.)
10551 if (s->cur_prompt->prompts[0]->result[0]) {
10552 smemclr(s->password, strlen(s->password));
10553 /* burn the evidence */
10554 sfree(s->password);
10556 dupstr(s->cur_prompt->prompts[0]->result);
10560 * Check the two new passwords match.
10562 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10563 s->cur_prompt->prompts[2]->result)
10566 /* They don't. Silly user. */
10567 c_write_str(ssh, "Passwords do not match\r\n");
10572 * Send the new password (along with the old one).
10573 * (see above for padding rationale)
10575 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10576 ssh2_pkt_addstring(s->pktout, ssh->username);
10577 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10578 /* service requested */
10579 ssh2_pkt_addstring(s->pktout, "password");
10580 ssh2_pkt_addbool(s->pktout, TRUE);
10581 ssh2_pkt_addstring(s->pktout, s->password);
10582 ssh2_pkt_addstring(s->pktout,
10583 s->cur_prompt->prompts[1]->result);
10584 free_prompts(s->cur_prompt);
10585 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10586 logevent("Sent new password");
10589 * Now see what the server has to say about it.
10590 * (If it's CHANGEREQ again, it's not happy with the
10593 crWaitUntilV(pktin);
10594 changereq_first_time = FALSE;
10599 * We need to reexamine the current pktin at the top
10600 * of the loop. Either:
10601 * - we weren't asked to change password at all, in
10602 * which case it's a SUCCESS or FAILURE with the
10604 * - we sent a new password, and the server was
10605 * either OK with it (SUCCESS or FAILURE w/partial
10606 * success) or unhappy with the _old_ password
10607 * (FAILURE w/o partial success)
10608 * In any of these cases, we go back to the top of
10609 * the loop and start again.
10614 * We don't need the old password any more, in any
10615 * case. Burn the evidence.
10617 smemclr(s->password, strlen(s->password));
10618 sfree(s->password);
10621 char *str = dupprintf("No supported authentication methods available"
10622 " (server sent: %.*s)",
10625 ssh_disconnect(ssh, str,
10626 "No supported authentication methods available",
10627 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10637 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10639 /* Clear up various bits and pieces from authentication. */
10640 if (s->publickey_blob) {
10641 sfree(s->publickey_algorithm);
10642 sfree(s->publickey_blob);
10643 sfree(s->publickey_comment);
10645 if (s->agent_response)
10646 sfree(s->agent_response);
10648 if (s->userauth_success && !ssh->bare_connection) {
10650 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10651 * packets since. Signal the transport layer to consider enacting
10652 * delayed compression.
10654 * (Relying on we_are_in is not sufficient, as
10655 * draft-miller-secsh-compression-delayed is quite clear that it
10656 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10657 * become set for other reasons.)
10659 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10662 ssh->channels = newtree234(ssh_channelcmp);
10665 * Set up handlers for some connection protocol messages, so we
10666 * don't have to handle them repeatedly in this coroutine.
10668 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10669 ssh2_msg_channel_window_adjust;
10670 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10671 ssh2_msg_global_request;
10674 * Create the main session channel.
10676 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10677 ssh->mainchan = NULL;
10679 ssh->mainchan = snew(struct ssh_channel);
10680 ssh->mainchan->ssh = ssh;
10681 ssh_channel_init(ssh->mainchan);
10683 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10685 * Just start a direct-tcpip channel and use it as the main
10688 ssh_send_port_open(ssh->mainchan,
10689 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10690 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10692 ssh->ncmode = TRUE;
10694 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10695 logevent("Opening session as main channel");
10696 ssh2_pkt_send(ssh, s->pktout);
10697 ssh->ncmode = FALSE;
10699 crWaitUntilV(pktin);
10700 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10701 bombout(("Server refused to open channel"));
10703 /* FIXME: error data comes back in FAILURE packet */
10705 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10706 bombout(("Server's channel confirmation cited wrong channel"));
10709 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10710 ssh->mainchan->halfopen = FALSE;
10711 ssh->mainchan->type = CHAN_MAINSESSION;
10712 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10713 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10714 update_specials_menu(ssh->frontend);
10715 logevent("Opened main channel");
10719 * Now we have a channel, make dispatch table entries for
10720 * general channel-based messages.
10722 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10723 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10724 ssh2_msg_channel_data;
10725 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10726 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10727 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10728 ssh2_msg_channel_open_confirmation;
10729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10730 ssh2_msg_channel_open_failure;
10731 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10732 ssh2_msg_channel_request;
10733 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10734 ssh2_msg_channel_open;
10735 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10736 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10739 * Now the connection protocol is properly up and running, with
10740 * all those dispatch table entries, so it's safe to let
10741 * downstreams start trying to open extra channels through us.
10743 if (ssh->connshare)
10744 share_activate(ssh->connshare, ssh->v_s);
10746 if (ssh->mainchan && ssh_is_simple(ssh)) {
10748 * This message indicates to the server that we promise
10749 * not to try to run any other channel in parallel with
10750 * this one, so it's safe for it to advertise a very large
10751 * window and leave the flow control to TCP.
10753 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10754 "simple@putty.projects.tartarus.org",
10756 ssh2_pkt_send(ssh, s->pktout);
10760 * Enable port forwardings.
10762 ssh_setup_portfwd(ssh, ssh->conf);
10764 if (ssh->mainchan && !ssh->ncmode) {
10766 * Send the CHANNEL_REQUESTS for the main session channel.
10767 * Each one is handled by its own little asynchronous
10771 /* Potentially enable X11 forwarding. */
10772 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10774 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10776 if (!ssh->x11disp) {
10777 /* FIXME: return an error message from x11_setup_display */
10778 logevent("X11 forwarding not enabled: unable to"
10779 " initialise X display");
10781 ssh->x11auth = x11_invent_fake_auth
10782 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10783 ssh->x11auth->disp = ssh->x11disp;
10785 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10789 /* Potentially enable agent forwarding. */
10790 if (ssh_agent_forwarding_permitted(ssh))
10791 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10793 /* Now allocate a pty for the session. */
10794 if (!conf_get_int(ssh->conf, CONF_nopty))
10795 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10797 /* Send environment variables. */
10798 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10801 * Start a shell or a remote command. We may have to attempt
10802 * this twice if the config data has provided a second choice
10809 if (ssh->fallback_cmd) {
10810 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10811 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10813 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10814 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10818 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10819 ssh2_response_authconn, NULL);
10820 ssh2_pkt_addstring(s->pktout, cmd);
10822 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10823 ssh2_response_authconn, NULL);
10824 ssh2_pkt_addstring(s->pktout, cmd);
10826 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10827 ssh2_response_authconn, NULL);
10829 ssh2_pkt_send(ssh, s->pktout);
10831 crWaitUntilV(pktin);
10833 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10834 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10835 bombout(("Unexpected response to shell/command request:"
10836 " packet type %d", pktin->type));
10840 * We failed to start the command. If this is the
10841 * fallback command, we really are finished; if it's
10842 * not, and if the fallback command exists, try falling
10843 * back to it before complaining.
10845 if (!ssh->fallback_cmd &&
10846 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10847 logevent("Primary command failed; attempting fallback");
10848 ssh->fallback_cmd = TRUE;
10851 bombout(("Server refused to start a shell/command"));
10854 logevent("Started a shell/command");
10859 ssh->editing = ssh->echoing = TRUE;
10862 ssh->state = SSH_STATE_SESSION;
10863 if (ssh->size_needed)
10864 ssh_size(ssh, ssh->term_width, ssh->term_height);
10865 if (ssh->eof_needed)
10866 ssh_special(ssh, TS_EOF);
10872 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10880 * _All_ the connection-layer packets we expect to
10881 * receive are now handled by the dispatch table.
10882 * Anything that reaches here must be bogus.
10885 bombout(("Strange packet received: type %d", pktin->type));
10887 } else if (ssh->mainchan) {
10889 * We have spare data. Add it to the channel buffer.
10891 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10899 * Handlers for SSH-2 messages that might arrive at any moment.
10901 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10903 /* log reason code in disconnect message */
10905 int reason, msglen;
10907 reason = ssh_pkt_getuint32(pktin);
10908 ssh_pkt_getstring(pktin, &msg, &msglen);
10910 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10911 buf = dupprintf("Received disconnect message (%s)",
10912 ssh2_disconnect_reasons[reason]);
10914 buf = dupprintf("Received disconnect message (unknown"
10915 " type %d)", reason);
10919 buf = dupprintf("Disconnection message text: %.*s",
10920 msglen, NULLTOEMPTY(msg));
10922 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10924 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10925 ssh2_disconnect_reasons[reason] : "unknown",
10926 msglen, NULLTOEMPTY(msg)));
10930 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10932 /* log the debug message */
10936 /* XXX maybe we should actually take notice of the return value */
10937 ssh2_pkt_getbool(pktin);
10938 ssh_pkt_getstring(pktin, &msg, &msglen);
10940 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10943 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10945 do_ssh2_transport(ssh, NULL, 0, pktin);
10949 * Called if we receive a packet that isn't allowed by the protocol.
10950 * This only applies to packets whose meaning PuTTY understands.
10951 * Entirely unknown packets are handled below.
10953 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10955 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10956 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10958 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10962 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10964 struct Packet *pktout;
10965 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10966 ssh2_pkt_adduint32(pktout, pktin->sequence);
10968 * UNIMPLEMENTED messages MUST appear in the same order as the
10969 * messages they respond to. Hence, never queue them.
10971 ssh2_pkt_send_noqueue(ssh, pktout);
10975 * Handle the top-level SSH-2 protocol.
10977 static void ssh2_protocol_setup(Ssh ssh)
10982 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10984 for (i = 0; i < 256; i++)
10985 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10988 * Initially, we only accept transport messages (and a few generic
10989 * ones). do_ssh2_authconn will add more when it starts.
10990 * Messages that are understood but not currently acceptable go to
10991 * ssh2_msg_unexpected.
10993 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10994 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10995 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10996 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10997 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10998 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10999 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
11000 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
11001 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
11002 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
11003 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
11004 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
11005 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
11006 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
11007 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
11008 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
11009 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
11010 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
11011 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
11012 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11013 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11014 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11025 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11028 * These messages have a special handler from the start.
11030 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11031 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
11032 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11035 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
11040 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
11042 for (i = 0; i < 256; i++)
11043 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
11046 * Initially, we set all ssh-connection messages to 'unexpected';
11047 * do_ssh2_authconn will fill things in properly. We also handle a
11048 * couple of messages from the transport protocol which aren't
11049 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
11052 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11053 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11054 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11056 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11057 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11058 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11059 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11060 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11061 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11062 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11063 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11064 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11065 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11067 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11070 * These messages have a special handler from the start.
11072 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11073 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11074 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11077 static void ssh2_timer(void *ctx, unsigned long now)
11079 Ssh ssh = (Ssh)ctx;
11081 if (ssh->state == SSH_STATE_CLOSED)
11084 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11085 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11086 now == ssh->next_rekey) {
11087 do_ssh2_transport(ssh, "timeout", -1, NULL);
11091 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11092 struct Packet *pktin)
11094 const unsigned char *in = (const unsigned char *)vin;
11095 if (ssh->state == SSH_STATE_CLOSED)
11099 ssh->incoming_data_size += pktin->encrypted_len;
11100 if (!ssh->kex_in_progress &&
11101 ssh->max_data_size != 0 &&
11102 ssh->incoming_data_size > ssh->max_data_size)
11103 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11107 ssh->packet_dispatch[pktin->type](ssh, pktin);
11108 else if (!ssh->protocol_initial_phase_done)
11109 do_ssh2_transport(ssh, in, inlen, pktin);
11111 do_ssh2_authconn(ssh, in, inlen, pktin);
11114 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11115 struct Packet *pktin)
11117 const unsigned char *in = (const unsigned char *)vin;
11118 if (ssh->state == SSH_STATE_CLOSED)
11122 ssh->packet_dispatch[pktin->type](ssh, pktin);
11124 do_ssh2_authconn(ssh, in, inlen, pktin);
11127 static void ssh_cache_conf_values(Ssh ssh)
11129 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11133 * Called to set up the connection.
11135 * Returns an error message, or NULL on success.
11137 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11139 const char *host, int port, char **realhost,
11140 int nodelay, int keepalive)
11145 ssh = snew(struct ssh_tag);
11146 ssh->conf = conf_copy(conf);
11147 ssh_cache_conf_values(ssh);
11148 ssh->version = 0; /* when not ready yet */
11150 ssh->cipher = NULL;
11151 ssh->v1_cipher_ctx = NULL;
11152 ssh->crcda_ctx = NULL;
11153 ssh->cscipher = NULL;
11154 ssh->cs_cipher_ctx = NULL;
11155 ssh->sccipher = NULL;
11156 ssh->sc_cipher_ctx = NULL;
11158 ssh->cs_mac_ctx = NULL;
11160 ssh->sc_mac_ctx = NULL;
11161 ssh->cscomp = NULL;
11162 ssh->cs_comp_ctx = NULL;
11163 ssh->sccomp = NULL;
11164 ssh->sc_comp_ctx = NULL;
11166 ssh->kex_ctx = NULL;
11167 ssh->hostkey = NULL;
11168 ssh->hostkey_str = NULL;
11169 ssh->exitcode = -1;
11170 ssh->close_expected = FALSE;
11171 ssh->clean_exit = FALSE;
11172 ssh->state = SSH_STATE_PREPACKET;
11173 ssh->size_needed = FALSE;
11174 ssh->eof_needed = FALSE;
11176 ssh->logctx = NULL;
11177 ssh->deferred_send_data = NULL;
11178 ssh->deferred_len = 0;
11179 ssh->deferred_size = 0;
11180 ssh->fallback_cmd = 0;
11181 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11182 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11183 ssh->x11disp = NULL;
11184 ssh->x11auth = NULL;
11185 ssh->x11authtree = newtree234(x11_authcmp);
11186 ssh->v1_compressing = FALSE;
11187 ssh->v2_outgoing_sequence = 0;
11188 ssh->ssh1_rdpkt_crstate = 0;
11189 ssh->ssh2_rdpkt_crstate = 0;
11190 ssh->ssh2_bare_rdpkt_crstate = 0;
11191 ssh->ssh_gotdata_crstate = 0;
11192 ssh->do_ssh1_connection_crstate = 0;
11193 ssh->do_ssh_init_state = NULL;
11194 ssh->do_ssh_connection_init_state = NULL;
11195 ssh->do_ssh1_login_state = NULL;
11196 ssh->do_ssh2_transport_state = NULL;
11197 ssh->do_ssh2_authconn_state = NULL;
11200 ssh->mainchan = NULL;
11201 ssh->throttled_all = 0;
11202 ssh->v1_stdout_throttling = 0;
11204 ssh->queuelen = ssh->queuesize = 0;
11205 ssh->queueing = FALSE;
11206 ssh->qhead = ssh->qtail = NULL;
11207 ssh->deferred_rekey_reason = NULL;
11208 bufchain_init(&ssh->queued_incoming_data);
11209 ssh->frozen = FALSE;
11210 ssh->username = NULL;
11211 ssh->sent_console_eof = FALSE;
11212 ssh->got_pty = FALSE;
11213 ssh->bare_connection = FALSE;
11214 ssh->X11_fwd_enabled = FALSE;
11215 ssh->connshare = NULL;
11216 ssh->attempting_connshare = FALSE;
11217 ssh->session_started = FALSE;
11218 ssh->specials = NULL;
11219 ssh->n_uncert_hostkeys = 0;
11220 ssh->cross_certifying = FALSE;
11222 *backend_handle = ssh;
11225 if (crypto_startup() == 0)
11226 return "Microsoft high encryption pack not installed!";
11229 ssh->frontend = frontend_handle;
11230 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11231 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11233 ssh->channels = NULL;
11234 ssh->rportfwds = NULL;
11235 ssh->portfwds = NULL;
11240 ssh->conn_throttle_count = 0;
11241 ssh->overall_bufsize = 0;
11242 ssh->fallback_cmd = 0;
11244 ssh->protocol = NULL;
11246 ssh->protocol_initial_phase_done = FALSE;
11248 ssh->pinger = NULL;
11250 ssh->incoming_data_size = ssh->outgoing_data_size =
11251 ssh->deferred_data_size = 0L;
11252 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11253 CONF_ssh_rekey_data));
11254 ssh->kex_in_progress = FALSE;
11256 ssh->auth_agent_query = NULL;
11259 ssh->gsslibs = NULL;
11262 random_ref(); /* do this now - may be needed by sharing setup code */
11264 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11273 static void ssh_free(void *handle)
11275 Ssh ssh = (Ssh) handle;
11276 struct ssh_channel *c;
11277 struct ssh_rportfwd *pf;
11278 struct X11FakeAuth *auth;
11280 if (ssh->v1_cipher_ctx)
11281 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11282 if (ssh->cs_cipher_ctx)
11283 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11284 if (ssh->sc_cipher_ctx)
11285 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11286 if (ssh->cs_mac_ctx)
11287 ssh->csmac->free_context(ssh->cs_mac_ctx);
11288 if (ssh->sc_mac_ctx)
11289 ssh->scmac->free_context(ssh->sc_mac_ctx);
11290 if (ssh->cs_comp_ctx) {
11292 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11294 zlib_compress_cleanup(ssh->cs_comp_ctx);
11296 if (ssh->sc_comp_ctx) {
11298 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11300 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11303 dh_cleanup(ssh->kex_ctx);
11304 sfree(ssh->savedhost);
11306 while (ssh->queuelen-- > 0)
11307 ssh_free_packet(ssh->queue[ssh->queuelen]);
11310 while (ssh->qhead) {
11311 struct queued_handler *qh = ssh->qhead;
11312 ssh->qhead = qh->next;
11315 ssh->qhead = ssh->qtail = NULL;
11317 if (ssh->channels) {
11318 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11319 ssh_channel_close_local(c, NULL);
11320 if (ssh->version == 2) {
11321 struct outstanding_channel_request *ocr, *nocr;
11322 ocr = c->v.v2.chanreq_head;
11324 ocr->handler(c, NULL, ocr->ctx);
11329 bufchain_clear(&c->v.v2.outbuffer);
11333 freetree234(ssh->channels);
11334 ssh->channels = NULL;
11337 if (ssh->connshare)
11338 sharestate_free(ssh->connshare);
11340 if (ssh->rportfwds) {
11341 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11343 freetree234(ssh->rportfwds);
11344 ssh->rportfwds = NULL;
11346 sfree(ssh->deferred_send_data);
11348 x11_free_display(ssh->x11disp);
11349 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11350 x11_free_fake_auth(auth);
11351 freetree234(ssh->x11authtree);
11352 sfree(ssh->do_ssh_init_state);
11353 sfree(ssh->do_ssh1_login_state);
11354 sfree(ssh->do_ssh2_transport_state);
11355 sfree(ssh->do_ssh2_authconn_state);
11358 sfree(ssh->fullhostname);
11359 sfree(ssh->hostkey_str);
11360 sfree(ssh->specials);
11361 if (ssh->crcda_ctx) {
11362 crcda_free_context(ssh->crcda_ctx);
11363 ssh->crcda_ctx = NULL;
11366 ssh_do_close(ssh, TRUE);
11367 expire_timer_context(ssh);
11369 pinger_free(ssh->pinger);
11370 bufchain_clear(&ssh->queued_incoming_data);
11371 sfree(ssh->username);
11372 conf_free(ssh->conf);
11374 if (ssh->auth_agent_query)
11375 agent_cancel_query(ssh->auth_agent_query);
11379 ssh_gss_cleanup(ssh->gsslibs);
11387 * Reconfigure the SSH backend.
11389 static void ssh_reconfig(void *handle, Conf *conf)
11391 Ssh ssh = (Ssh) handle;
11392 const char *rekeying = NULL;
11393 int rekey_mandatory = FALSE;
11394 unsigned long old_max_data_size;
11397 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11399 ssh_setup_portfwd(ssh, conf);
11401 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11402 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11404 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11405 unsigned long now = GETTICKCOUNT();
11407 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11408 rekeying = "timeout shortened";
11410 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11414 old_max_data_size = ssh->max_data_size;
11415 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11416 CONF_ssh_rekey_data));
11417 if (old_max_data_size != ssh->max_data_size &&
11418 ssh->max_data_size != 0) {
11419 if (ssh->outgoing_data_size > ssh->max_data_size ||
11420 ssh->incoming_data_size > ssh->max_data_size)
11421 rekeying = "data limit lowered";
11424 if (conf_get_int(ssh->conf, CONF_compression) !=
11425 conf_get_int(conf, CONF_compression)) {
11426 rekeying = "compression setting changed";
11427 rekey_mandatory = TRUE;
11430 for (i = 0; i < CIPHER_MAX; i++)
11431 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11432 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11433 rekeying = "cipher settings changed";
11434 rekey_mandatory = TRUE;
11436 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11437 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11438 rekeying = "cipher settings changed";
11439 rekey_mandatory = TRUE;
11442 conf_free(ssh->conf);
11443 ssh->conf = conf_copy(conf);
11444 ssh_cache_conf_values(ssh);
11446 if (!ssh->bare_connection && rekeying) {
11447 if (!ssh->kex_in_progress) {
11448 do_ssh2_transport(ssh, rekeying, -1, NULL);
11449 } else if (rekey_mandatory) {
11450 ssh->deferred_rekey_reason = rekeying;
11456 * Called to send data down the SSH connection.
11458 static int ssh_send(void *handle, const char *buf, int len)
11460 Ssh ssh = (Ssh) handle;
11462 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11465 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11467 return ssh_sendbuffer(ssh);
11471 * Called to query the current amount of buffered stdin data.
11473 static int ssh_sendbuffer(void *handle)
11475 Ssh ssh = (Ssh) handle;
11476 int override_value;
11478 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11482 * If the SSH socket itself has backed up, add the total backup
11483 * size on that to any individual buffer on the stdin channel.
11485 override_value = 0;
11486 if (ssh->throttled_all)
11487 override_value = ssh->overall_bufsize;
11489 if (ssh->version == 1) {
11490 return override_value;
11491 } else if (ssh->version == 2) {
11492 if (!ssh->mainchan)
11493 return override_value;
11495 return (override_value +
11496 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11503 * Called to set the size of the window from SSH's POV.
11505 static void ssh_size(void *handle, int width, int height)
11507 Ssh ssh = (Ssh) handle;
11508 struct Packet *pktout;
11510 ssh->term_width = width;
11511 ssh->term_height = height;
11513 switch (ssh->state) {
11514 case SSH_STATE_BEFORE_SIZE:
11515 case SSH_STATE_PREPACKET:
11516 case SSH_STATE_CLOSED:
11517 break; /* do nothing */
11518 case SSH_STATE_INTERMED:
11519 ssh->size_needed = TRUE; /* buffer for later */
11521 case SSH_STATE_SESSION:
11522 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11523 if (ssh->version == 1) {
11524 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11525 PKT_INT, ssh->term_height,
11526 PKT_INT, ssh->term_width,
11527 PKT_INT, 0, PKT_INT, 0, PKT_END);
11528 } else if (ssh->mainchan) {
11529 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11531 ssh2_pkt_adduint32(pktout, ssh->term_width);
11532 ssh2_pkt_adduint32(pktout, ssh->term_height);
11533 ssh2_pkt_adduint32(pktout, 0);
11534 ssh2_pkt_adduint32(pktout, 0);
11535 ssh2_pkt_send(ssh, pktout);
11543 * Return a list of the special codes that make sense in this
11546 static const struct telnet_special *ssh_get_specials(void *handle)
11548 static const struct telnet_special ssh1_ignore_special[] = {
11549 {"IGNORE message", TS_NOP}
11551 static const struct telnet_special ssh2_ignore_special[] = {
11552 {"IGNORE message", TS_NOP},
11554 static const struct telnet_special ssh2_rekey_special[] = {
11555 {"Repeat key exchange", TS_REKEY},
11557 static const struct telnet_special ssh2_session_specials[] = {
11560 /* These are the signal names defined by RFC 4254.
11561 * They include all the ISO C signals, but are a subset of the POSIX
11562 * required signals. */
11563 {"SIGINT (Interrupt)", TS_SIGINT},
11564 {"SIGTERM (Terminate)", TS_SIGTERM},
11565 {"SIGKILL (Kill)", TS_SIGKILL},
11566 {"SIGQUIT (Quit)", TS_SIGQUIT},
11567 {"SIGHUP (Hangup)", TS_SIGHUP},
11568 {"More signals", TS_SUBMENU},
11569 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11570 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11571 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11572 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11573 {NULL, TS_EXITMENU}
11575 static const struct telnet_special specials_end[] = {
11576 {NULL, TS_EXITMENU}
11579 struct telnet_special *specials = NULL;
11580 int nspecials = 0, specialsize = 0;
11582 Ssh ssh = (Ssh) handle;
11584 sfree(ssh->specials);
11586 #define ADD_SPECIALS(name) do \
11588 int len = lenof(name); \
11589 if (nspecials + len > specialsize) { \
11590 specialsize = (nspecials + len) * 5 / 4 + 32; \
11591 specials = sresize(specials, specialsize, struct telnet_special); \
11593 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11594 nspecials += len; \
11597 if (ssh->version == 1) {
11598 /* Don't bother offering IGNORE if we've decided the remote
11599 * won't cope with it, since we wouldn't bother sending it if
11601 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11602 ADD_SPECIALS(ssh1_ignore_special);
11603 } else if (ssh->version == 2) {
11604 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11605 ADD_SPECIALS(ssh2_ignore_special);
11606 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11607 ADD_SPECIALS(ssh2_rekey_special);
11609 ADD_SPECIALS(ssh2_session_specials);
11611 if (ssh->n_uncert_hostkeys) {
11612 static const struct telnet_special uncert_start[] = {
11614 {"Cache new host key type", TS_SUBMENU},
11616 static const struct telnet_special uncert_end[] = {
11617 {NULL, TS_EXITMENU},
11621 ADD_SPECIALS(uncert_start);
11622 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11623 struct telnet_special uncert[1];
11624 const struct ssh_signkey *alg =
11625 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11626 uncert[0].name = alg->name;
11627 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11628 ADD_SPECIALS(uncert);
11630 ADD_SPECIALS(uncert_end);
11632 } /* else we're not ready yet */
11635 ADD_SPECIALS(specials_end);
11637 ssh->specials = specials;
11644 #undef ADD_SPECIALS
11648 * Send special codes. TS_EOF is useful for `plink', so you
11649 * can send an EOF and collect resulting output (e.g. `plink
11652 static void ssh_special(void *handle, Telnet_Special code)
11654 Ssh ssh = (Ssh) handle;
11655 struct Packet *pktout;
11657 if (code == TS_EOF) {
11658 if (ssh->state != SSH_STATE_SESSION) {
11660 * Buffer the EOF in case we are pre-SESSION, so we can
11661 * send it as soon as we reach SESSION.
11663 if (code == TS_EOF)
11664 ssh->eof_needed = TRUE;
11667 if (ssh->version == 1) {
11668 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11669 } else if (ssh->mainchan) {
11670 sshfwd_write_eof(ssh->mainchan);
11671 ssh->send_ok = 0; /* now stop trying to read from stdin */
11673 logevent("Sent EOF message");
11674 } else if (code == TS_PING || code == TS_NOP) {
11675 if (ssh->state == SSH_STATE_CLOSED
11676 || ssh->state == SSH_STATE_PREPACKET) return;
11677 if (ssh->version == 1) {
11678 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11679 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11681 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11682 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11683 ssh2_pkt_addstring_start(pktout);
11684 ssh2_pkt_send_noqueue(ssh, pktout);
11687 } else if (code == TS_REKEY) {
11688 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11689 ssh->version == 2) {
11690 do_ssh2_transport(ssh, "at user request", -1, NULL);
11692 } else if (code >= TS_LOCALSTART) {
11693 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11694 ssh->cross_certifying = TRUE;
11695 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11696 ssh->version == 2) {
11697 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11699 } else if (code == TS_BRK) {
11700 if (ssh->state == SSH_STATE_CLOSED
11701 || ssh->state == SSH_STATE_PREPACKET) return;
11702 if (ssh->version == 1) {
11703 logevent("Unable to send BREAK signal in SSH-1");
11704 } else if (ssh->mainchan) {
11705 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11706 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11707 ssh2_pkt_send(ssh, pktout);
11710 /* Is is a POSIX signal? */
11711 const char *signame = NULL;
11712 if (code == TS_SIGABRT) signame = "ABRT";
11713 if (code == TS_SIGALRM) signame = "ALRM";
11714 if (code == TS_SIGFPE) signame = "FPE";
11715 if (code == TS_SIGHUP) signame = "HUP";
11716 if (code == TS_SIGILL) signame = "ILL";
11717 if (code == TS_SIGINT) signame = "INT";
11718 if (code == TS_SIGKILL) signame = "KILL";
11719 if (code == TS_SIGPIPE) signame = "PIPE";
11720 if (code == TS_SIGQUIT) signame = "QUIT";
11721 if (code == TS_SIGSEGV) signame = "SEGV";
11722 if (code == TS_SIGTERM) signame = "TERM";
11723 if (code == TS_SIGUSR1) signame = "USR1";
11724 if (code == TS_SIGUSR2) signame = "USR2";
11725 /* The SSH-2 protocol does in principle support arbitrary named
11726 * signals, including signame@domain, but we don't support those. */
11728 /* It's a signal. */
11729 if (ssh->version == 2 && ssh->mainchan) {
11730 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11731 ssh2_pkt_addstring(pktout, signame);
11732 ssh2_pkt_send(ssh, pktout);
11733 logeventf(ssh, "Sent signal SIG%s", signame);
11736 /* Never heard of it. Do nothing */
11741 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11743 Ssh ssh = (Ssh) handle;
11744 struct ssh_channel *c;
11745 c = snew(struct ssh_channel);
11748 ssh_channel_init(c);
11749 c->halfopen = TRUE;
11750 c->type = CHAN_SOCKDATA;/* identify channel type */
11755 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11757 struct ssh_channel *c;
11758 c = snew(struct ssh_channel);
11761 ssh_channel_init(c);
11762 c->type = CHAN_SHARING;
11763 c->u.sharing.ctx = sharing_ctx;
11767 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11769 struct ssh_channel *c;
11771 c = find234(ssh->channels, &localid, ssh_channelfind);
11773 ssh_channel_destroy(c);
11776 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11777 const void *data, int datalen,
11778 const char *additional_log_text)
11780 struct Packet *pkt;
11782 pkt = ssh2_pkt_init(type);
11783 pkt->downstream_id = id;
11784 pkt->additional_log_text = additional_log_text;
11785 ssh2_pkt_adddata(pkt, data, datalen);
11786 ssh2_pkt_send(ssh, pkt);
11790 * This is called when stdout/stderr (the entity to which
11791 * from_backend sends data) manages to clear some backlog.
11793 static void ssh_unthrottle(void *handle, int bufsize)
11795 Ssh ssh = (Ssh) handle;
11797 if (ssh->version == 1) {
11798 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11799 ssh->v1_stdout_throttling = 0;
11800 ssh_throttle_conn(ssh, -1);
11804 ssh_channel_unthrottle(ssh->mainchan, bufsize);
11808 * Now process any SSH connection data that was stashed in our
11809 * queue while we were frozen.
11811 ssh_process_queued_incoming_data(ssh);
11814 void ssh_send_port_open(void *channel, const char *hostname, int port,
11817 struct ssh_channel *c = (struct ssh_channel *)channel;
11819 struct Packet *pktout;
11821 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11823 if (ssh->version == 1) {
11824 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11825 PKT_INT, c->localid,
11828 /* PKT_STR, <org:orgport>, */
11831 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11833 char *trimmed_host = host_strduptrim(hostname);
11834 ssh2_pkt_addstring(pktout, trimmed_host);
11835 sfree(trimmed_host);
11837 ssh2_pkt_adduint32(pktout, port);
11839 * We make up values for the originator data; partly it's
11840 * too much hassle to keep track, and partly I'm not
11841 * convinced the server should be told details like that
11842 * about my local network configuration.
11843 * The "originator IP address" is syntactically a numeric
11844 * IP address, and some servers (e.g., Tectia) get upset
11845 * if it doesn't match this syntax.
11847 ssh2_pkt_addstring(pktout, "0.0.0.0");
11848 ssh2_pkt_adduint32(pktout, 0);
11849 ssh2_pkt_send(ssh, pktout);
11853 static int ssh_connected(void *handle)
11855 Ssh ssh = (Ssh) handle;
11856 return ssh->s != NULL;
11859 static int ssh_sendok(void *handle)
11861 Ssh ssh = (Ssh) handle;
11862 return ssh->send_ok;
11865 static int ssh_ldisc(void *handle, int option)
11867 Ssh ssh = (Ssh) handle;
11868 if (option == LD_ECHO)
11869 return ssh->echoing;
11870 if (option == LD_EDIT)
11871 return ssh->editing;
11875 static void ssh_provide_ldisc(void *handle, void *ldisc)
11877 Ssh ssh = (Ssh) handle;
11878 ssh->ldisc = ldisc;
11881 static void ssh_provide_logctx(void *handle, void *logctx)
11883 Ssh ssh = (Ssh) handle;
11884 ssh->logctx = logctx;
11887 static int ssh_return_exitcode(void *handle)
11889 Ssh ssh = (Ssh) handle;
11890 if (ssh->s != NULL)
11893 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11897 * cfg_info for SSH is the protocol running in this session.
11898 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11899 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11901 static int ssh_cfg_info(void *handle)
11903 Ssh ssh = (Ssh) handle;
11904 if (ssh->version == 0)
11905 return 0; /* don't know yet */
11906 else if (ssh->bare_connection)
11909 return ssh->version;
11913 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11914 * that fails. This variable is the means by which scp.c can reach
11915 * into the SSH code and find out which one it got.
11917 extern int ssh_fallback_cmd(void *handle)
11919 Ssh ssh = (Ssh) handle;
11920 return ssh->fallback_cmd;
11923 Backend ssh_backend = {
11933 ssh_return_exitcode,
11937 ssh_provide_logctx,
11940 ssh_test_for_upstream,