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 void ssh2_channel_check_close(struct ssh_channel *c);
369 static void ssh_channel_destroy(struct ssh_channel *c);
370 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize);
371 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
374 * Buffer management constants. There are several of these for
375 * various different purposes:
377 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
378 * on a local data stream before we throttle the whole SSH
379 * connection (in SSH-1 only). Throttling the whole connection is
380 * pretty drastic so we set this high in the hope it won't
383 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
384 * on the SSH connection itself before we defensively throttle
385 * _all_ local data streams. This is pretty drastic too (though
386 * thankfully unlikely in SSH-2 since the window mechanism should
387 * ensure that the server never has any need to throttle its end
388 * of the connection), so we set this high as well.
390 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
393 * - OUR_V2_BIGWIN is the window size we advertise for the only
394 * channel in a simple connection. It must be <= INT_MAX.
396 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
397 * to the remote side. This actually has nothing to do with the
398 * size of the _packet_, but is instead a limit on the amount
399 * of data we're willing to receive in a single SSH2 channel
402 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
403 * _packet_ we're prepared to cope with. It must be a multiple
404 * of the cipher block size, and must be at least 35000.
407 #define SSH1_BUFFER_LIMIT 32768
408 #define SSH_MAX_BACKLOG 32768
409 #define OUR_V2_WINSIZE 16384
410 #define OUR_V2_BIGWIN 0x7fffffff
411 #define OUR_V2_MAXPKT 0x4000UL
412 #define OUR_V2_PACKETLIMIT 0x9000UL
414 struct ssh_signkey_with_user_pref_id {
415 const struct ssh_signkey *alg;
418 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
419 { &ssh_ecdsa_ed25519, HK_ED25519 },
420 { &ssh_ecdsa_nistp256, HK_ECDSA },
421 { &ssh_ecdsa_nistp384, HK_ECDSA },
422 { &ssh_ecdsa_nistp521, HK_ECDSA },
423 { &ssh_dss, HK_DSA },
424 { &ssh_rsa, HK_RSA },
427 const static struct ssh_mac *const macs[] = {
428 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
430 const static struct ssh_mac *const buggymacs[] = {
431 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
434 static void *ssh_comp_none_init(void)
438 static void ssh_comp_none_cleanup(void *handle)
441 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
442 unsigned char **outblock, int *outlen)
446 static int ssh_comp_none_disable(void *handle)
450 const static struct ssh_compress ssh_comp_none = {
452 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
453 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
454 ssh_comp_none_disable, NULL
456 extern const struct ssh_compress ssh_zlib;
457 const static struct ssh_compress *const compressions[] = {
458 &ssh_zlib, &ssh_comp_none
461 enum { /* channel types */
466 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
468 * CHAN_SHARING indicates a channel which is tracked here on
469 * behalf of a connection-sharing downstream. We do almost nothing
470 * with these channels ourselves: all messages relating to them
471 * get thrown straight to sshshare.c and passed on almost
472 * unmodified to downstream.
476 * CHAN_ZOMBIE is used to indicate a channel for which we've
477 * already destroyed the local data source: for instance, if a
478 * forwarded port experiences a socket error on the local side, we
479 * immediately destroy its local socket and turn the SSH channel
485 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
486 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
487 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
490 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
493 struct outstanding_channel_request {
494 cchandler_fn_t handler;
496 struct outstanding_channel_request *next;
500 * 2-3-4 tree storing channels.
503 Ssh ssh; /* pointer back to main context */
504 unsigned remoteid, localid;
506 /* True if we opened this channel but server hasn't confirmed. */
509 * In SSH-1, this value contains four bits:
511 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
512 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
513 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
514 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
516 * A channel is completely finished with when all four bits are set.
518 * In SSH-2, the four bits mean:
520 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
521 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
522 * 4 We have received SSH2_MSG_CHANNEL_EOF.
523 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
525 * A channel is completely finished with when we have both sent
526 * and received CLOSE.
528 * The symbolic constants below use the SSH-2 terminology, which
529 * is a bit confusing in SSH-1, but we have to use _something_.
531 #define CLOSES_SENT_EOF 1
532 #define CLOSES_SENT_CLOSE 2
533 #define CLOSES_RCVD_EOF 4
534 #define CLOSES_RCVD_CLOSE 8
538 * This flag indicates that an EOF is pending on the outgoing side
539 * of the channel: that is, wherever we're getting the data for
540 * this channel has sent us some data followed by EOF. We can't
541 * actually send the EOF until we've finished sending the data, so
542 * we set this flag instead to remind us to do so once our buffer
548 * True if this channel is causing the underlying connection to be
553 struct ssh2_data_channel {
555 unsigned remwindow, remmaxpkt;
556 /* locwindow is signed so we can cope with excess data. */
557 int locwindow, locmaxwin;
559 * remlocwin is the amount of local window that we think
560 * the remote end had available to it after it sent the
561 * last data packet or window adjust ack.
565 * These store the list of channel requests that haven't
568 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
569 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
573 struct ssh_agent_channel {
574 unsigned char *message;
575 unsigned char msglen[4];
576 unsigned lensofar, totallen;
577 int outstanding_requests;
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 #define logevent(s) logevent(ssh->frontend, s)
990 /* logevent, only printf-formatted. */
991 static void logeventf(Ssh ssh, const char *fmt, ...)
997 buf = dupvprintf(fmt, ap);
1003 static void bomb_out(Ssh ssh, char *text)
1005 ssh_do_close(ssh, FALSE);
1007 connection_fatal(ssh->frontend, "%s", text);
1011 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1013 /* Helper function for common bits of parsing ttymodes. */
1014 static void parse_ttymodes(Ssh ssh,
1015 void (*do_mode)(void *data,
1016 const struct ssh_ttymode *mode,
1021 const struct ssh_ttymode *mode;
1023 char default_val[2];
1025 strcpy(default_val, "A");
1027 for (i = 0; i < lenof(ssh_ttymodes); i++) {
1028 mode = ssh_ttymodes + i;
1029 val = conf_get_str_str_opt(ssh->conf, CONF_ttymodes, mode->mode);
1034 * val[0] is either 'V', indicating that an explicit value
1035 * follows it, or 'A' indicating that we should pass the
1036 * value through from the local environment via get_ttymode.
1038 if (val[0] == 'A') {
1039 val = get_ttymode(ssh->frontend, mode->mode);
1041 do_mode(data, mode, val);
1045 do_mode(data, mode, val + 1); /* skip the 'V' */
1049 static int ssh_channelcmp(void *av, void *bv)
1051 struct ssh_channel *a = (struct ssh_channel *) av;
1052 struct ssh_channel *b = (struct ssh_channel *) bv;
1053 if (a->localid < b->localid)
1055 if (a->localid > b->localid)
1059 static int ssh_channelfind(void *av, void *bv)
1061 unsigned *a = (unsigned *) av;
1062 struct ssh_channel *b = (struct ssh_channel *) bv;
1063 if (*a < b->localid)
1065 if (*a > b->localid)
1070 static int ssh_rportcmp_ssh1(void *av, void *bv)
1072 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1073 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1075 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1076 return i < 0 ? -1 : +1;
1077 if (a->dport > b->dport)
1079 if (a->dport < b->dport)
1084 static int ssh_rportcmp_ssh2(void *av, void *bv)
1086 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1087 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1089 if ( (i = strcmp(a->shost, b->shost)) != 0)
1090 return i < 0 ? -1 : +1;
1091 if (a->sport > b->sport)
1093 if (a->sport < b->sport)
1099 * Special form of strcmp which can cope with NULL inputs. NULL is
1100 * defined to sort before even the empty string.
1102 static int nullstrcmp(const char *a, const char *b)
1104 if (a == NULL && b == NULL)
1110 return strcmp(a, b);
1113 static int ssh_portcmp(void *av, void *bv)
1115 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1116 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1118 if (a->type > b->type)
1120 if (a->type < b->type)
1122 if (a->addressfamily > b->addressfamily)
1124 if (a->addressfamily < b->addressfamily)
1126 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1127 return i < 0 ? -1 : +1;
1128 if (a->sport > b->sport)
1130 if (a->sport < b->sport)
1132 if (a->type != 'D') {
1133 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1134 return i < 0 ? -1 : +1;
1135 if (a->dport > b->dport)
1137 if (a->dport < b->dport)
1143 static int alloc_channel_id(Ssh ssh)
1145 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1146 unsigned low, high, mid;
1148 struct ssh_channel *c;
1151 * First-fit allocation of channel numbers: always pick the
1152 * lowest unused one. To do this, binary-search using the
1153 * counted B-tree to find the largest channel ID which is in a
1154 * contiguous sequence from the beginning. (Precisely
1155 * everything in that sequence must have ID equal to its tree
1156 * index plus CHANNEL_NUMBER_OFFSET.)
1158 tsize = count234(ssh->channels);
1162 while (high - low > 1) {
1163 mid = (high + low) / 2;
1164 c = index234(ssh->channels, mid);
1165 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1166 low = mid; /* this one is fine */
1168 high = mid; /* this one is past it */
1171 * Now low points to either -1, or the tree index of the
1172 * largest ID in the initial sequence.
1175 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1176 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1178 return low + 1 + CHANNEL_NUMBER_OFFSET;
1181 static void c_write_stderr(int trusted, const char *buf, int len)
1184 for (i = 0; i < len; i++)
1185 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1186 fputc(buf[i], stderr);
1189 static void c_write(Ssh ssh, const char *buf, int len)
1191 if (flags & FLAG_STDERR)
1192 c_write_stderr(1, buf, len);
1194 from_backend(ssh->frontend, 1, buf, len);
1197 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1199 if (flags & FLAG_STDERR)
1200 c_write_stderr(0, buf, len);
1202 from_backend_untrusted(ssh->frontend, buf, len);
1205 static void c_write_str(Ssh ssh, const char *buf)
1207 c_write(ssh, buf, strlen(buf));
1210 static void ssh_free_packet(struct Packet *pkt)
1215 static struct Packet *ssh_new_packet(void)
1217 struct Packet *pkt = snew(struct Packet);
1219 pkt->body = pkt->data = NULL;
1225 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1228 struct logblank_t blanks[4];
1234 if (ssh->logomitdata &&
1235 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1236 pkt->type == SSH1_SMSG_STDERR_DATA ||
1237 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1238 /* "Session data" packets - omit the data string. */
1239 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1240 ssh_pkt_getuint32(pkt); /* skip channel id */
1241 blanks[nblanks].offset = pkt->savedpos + 4;
1242 blanks[nblanks].type = PKTLOG_OMIT;
1243 ssh_pkt_getstring(pkt, &str, &slen);
1245 blanks[nblanks].len = slen;
1249 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1250 ssh1_pkt_type(pkt->type),
1251 pkt->body, pkt->length, nblanks, blanks, NULL,
1255 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1258 struct logblank_t blanks[4];
1263 * For outgoing packets, pkt->length represents the length of the
1264 * whole packet starting at pkt->data (including some header), and
1265 * pkt->body refers to the point within that where the log-worthy
1266 * payload begins. However, incoming packets expect pkt->length to
1267 * represent only the payload length (that is, it's measured from
1268 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1269 * packet to conform to the incoming-packet semantics, so that we
1270 * can analyse it with the ssh_pkt_get functions.
1272 pkt->length -= (pkt->body - pkt->data);
1275 if (ssh->logomitdata &&
1276 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1277 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1278 /* "Session data" packets - omit the data string. */
1279 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1280 ssh_pkt_getuint32(pkt); /* skip channel id */
1281 blanks[nblanks].offset = pkt->savedpos + 4;
1282 blanks[nblanks].type = PKTLOG_OMIT;
1283 ssh_pkt_getstring(pkt, &str, &slen);
1285 blanks[nblanks].len = slen;
1290 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1291 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1292 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1293 conf_get_int(ssh->conf, CONF_logomitpass)) {
1294 /* If this is a password or similar packet, blank the password(s). */
1295 blanks[nblanks].offset = 0;
1296 blanks[nblanks].len = pkt->length;
1297 blanks[nblanks].type = PKTLOG_BLANK;
1299 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1300 conf_get_int(ssh->conf, CONF_logomitpass)) {
1302 * If this is an X forwarding request packet, blank the fake
1305 * Note that while we blank the X authentication data here, we
1306 * don't take any special action to blank the start of an X11
1307 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1308 * an X connection without having session blanking enabled is
1309 * likely to leak your cookie into the log.
1312 ssh_pkt_getstring(pkt, &str, &slen);
1313 blanks[nblanks].offset = pkt->savedpos;
1314 blanks[nblanks].type = PKTLOG_BLANK;
1315 ssh_pkt_getstring(pkt, &str, &slen);
1317 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1322 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1323 ssh1_pkt_type(pkt->data[12]),
1324 pkt->body, pkt->length,
1325 nblanks, blanks, NULL, 0, NULL);
1328 * Undo the above adjustment of pkt->length, to put the packet
1329 * back in the state we found it.
1331 pkt->length += (pkt->body - pkt->data);
1335 * Collect incoming data in the incoming packet buffer.
1336 * Decipher and verify the packet when it is completely read.
1337 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1338 * Update the *data and *datalen variables.
1339 * Return a Packet structure when a packet is completed.
1341 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1344 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1346 crBegin(ssh->ssh1_rdpkt_crstate);
1348 st->pktin = ssh_new_packet();
1350 st->pktin->type = 0;
1351 st->pktin->length = 0;
1353 for (st->i = st->len = 0; st->i < 4; st->i++) {
1354 while ((*datalen) == 0)
1356 st->len = (st->len << 8) + **data;
1357 (*data)++, (*datalen)--;
1360 st->pad = 8 - (st->len % 8);
1361 st->biglen = st->len + st->pad;
1362 st->pktin->length = st->len - 5;
1364 if (st->biglen < 0) {
1365 bombout(("Extremely large packet length from server suggests"
1366 " data stream corruption"));
1367 ssh_free_packet(st->pktin);
1371 st->pktin->maxlen = st->biglen;
1372 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1374 st->to_read = st->biglen;
1375 st->p = st->pktin->data;
1376 while (st->to_read > 0) {
1377 st->chunk = st->to_read;
1378 while ((*datalen) == 0)
1380 if (st->chunk > (*datalen))
1381 st->chunk = (*datalen);
1382 memcpy(st->p, *data, st->chunk);
1384 *datalen -= st->chunk;
1386 st->to_read -= st->chunk;
1389 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1390 st->biglen, NULL)) {
1391 bombout(("Network attack (CRC compensation) detected!"));
1392 ssh_free_packet(st->pktin);
1397 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1399 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1400 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1401 if (st->gotcrc != st->realcrc) {
1402 bombout(("Incorrect CRC received on packet"));
1403 ssh_free_packet(st->pktin);
1407 st->pktin->body = st->pktin->data + st->pad + 1;
1409 if (ssh->v1_compressing) {
1410 unsigned char *decompblk;
1412 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1413 st->pktin->body - 1, st->pktin->length + 1,
1414 &decompblk, &decomplen)) {
1415 bombout(("Zlib decompression encountered invalid data"));
1416 ssh_free_packet(st->pktin);
1420 if (st->pktin->maxlen < st->pad + decomplen) {
1421 st->pktin->maxlen = st->pad + decomplen;
1422 st->pktin->data = sresize(st->pktin->data,
1423 st->pktin->maxlen + APIEXTRA,
1425 st->pktin->body = st->pktin->data + st->pad + 1;
1428 memcpy(st->pktin->body - 1, decompblk, decomplen);
1430 st->pktin->length = decomplen - 1;
1433 st->pktin->type = st->pktin->body[-1];
1436 * Now pktin->body and pktin->length identify the semantic content
1437 * of the packet, excluding the initial type byte.
1441 ssh1_log_incoming_packet(ssh, st->pktin);
1443 st->pktin->savedpos = 0;
1445 crFinish(st->pktin);
1448 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1451 struct logblank_t blanks[4];
1457 if (ssh->logomitdata &&
1458 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1459 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1460 /* "Session data" packets - omit the data string. */
1461 ssh_pkt_getuint32(pkt); /* skip channel id */
1462 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1463 ssh_pkt_getuint32(pkt); /* skip extended data type */
1464 blanks[nblanks].offset = pkt->savedpos + 4;
1465 blanks[nblanks].type = PKTLOG_OMIT;
1466 ssh_pkt_getstring(pkt, &str, &slen);
1468 blanks[nblanks].len = slen;
1473 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1474 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1475 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1479 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1482 struct logblank_t blanks[4];
1487 * For outgoing packets, pkt->length represents the length of the
1488 * whole packet starting at pkt->data (including some header), and
1489 * pkt->body refers to the point within that where the log-worthy
1490 * payload begins. However, incoming packets expect pkt->length to
1491 * represent only the payload length (that is, it's measured from
1492 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1493 * packet to conform to the incoming-packet semantics, so that we
1494 * can analyse it with the ssh_pkt_get functions.
1496 pkt->length -= (pkt->body - pkt->data);
1499 if (ssh->logomitdata &&
1500 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1501 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1502 /* "Session data" packets - omit the data string. */
1503 ssh_pkt_getuint32(pkt); /* skip channel id */
1504 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1505 ssh_pkt_getuint32(pkt); /* skip extended data type */
1506 blanks[nblanks].offset = pkt->savedpos + 4;
1507 blanks[nblanks].type = PKTLOG_OMIT;
1508 ssh_pkt_getstring(pkt, &str, &slen);
1510 blanks[nblanks].len = slen;
1515 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1516 conf_get_int(ssh->conf, CONF_logomitpass)) {
1517 /* If this is a password packet, blank the password(s). */
1519 ssh_pkt_getstring(pkt, &str, &slen);
1520 ssh_pkt_getstring(pkt, &str, &slen);
1521 ssh_pkt_getstring(pkt, &str, &slen);
1522 if (slen == 8 && !memcmp(str, "password", 8)) {
1523 ssh2_pkt_getbool(pkt);
1524 /* Blank the password field. */
1525 blanks[nblanks].offset = pkt->savedpos;
1526 blanks[nblanks].type = PKTLOG_BLANK;
1527 ssh_pkt_getstring(pkt, &str, &slen);
1529 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1531 /* If there's another password field beyond it (change of
1532 * password), blank that too. */
1533 ssh_pkt_getstring(pkt, &str, &slen);
1535 blanks[nblanks-1].len =
1536 pkt->savedpos - blanks[nblanks].offset;
1539 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1540 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1541 conf_get_int(ssh->conf, CONF_logomitpass)) {
1542 /* If this is a keyboard-interactive response packet, blank
1545 ssh_pkt_getuint32(pkt);
1546 blanks[nblanks].offset = pkt->savedpos;
1547 blanks[nblanks].type = PKTLOG_BLANK;
1549 ssh_pkt_getstring(pkt, &str, &slen);
1553 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1555 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1556 conf_get_int(ssh->conf, CONF_logomitpass)) {
1558 * If this is an X forwarding request packet, blank the fake
1561 * Note that while we blank the X authentication data here, we
1562 * don't take any special action to blank the start of an X11
1563 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1564 * an X connection without having session blanking enabled is
1565 * likely to leak your cookie into the log.
1568 ssh_pkt_getuint32(pkt);
1569 ssh_pkt_getstring(pkt, &str, &slen);
1570 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1571 ssh2_pkt_getbool(pkt);
1572 ssh2_pkt_getbool(pkt);
1573 ssh_pkt_getstring(pkt, &str, &slen);
1574 blanks[nblanks].offset = pkt->savedpos;
1575 blanks[nblanks].type = PKTLOG_BLANK;
1576 ssh_pkt_getstring(pkt, &str, &slen);
1578 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1584 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1585 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1586 pkt->body, pkt->length, nblanks, blanks,
1587 &ssh->v2_outgoing_sequence,
1588 pkt->downstream_id, pkt->additional_log_text);
1591 * Undo the above adjustment of pkt->length, to put the packet
1592 * back in the state we found it.
1594 pkt->length += (pkt->body - pkt->data);
1597 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1600 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1602 crBegin(ssh->ssh2_rdpkt_crstate);
1604 st->pktin = ssh_new_packet();
1606 st->pktin->type = 0;
1607 st->pktin->length = 0;
1609 st->cipherblk = ssh->sccipher->blksize;
1612 if (st->cipherblk < 8)
1614 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1616 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1617 ssh->scmac && !ssh->scmac_etm) {
1619 * When dealing with a CBC-mode cipher, we want to avoid the
1620 * possibility of an attacker's tweaking the ciphertext stream
1621 * so as to cause us to feed the same block to the block
1622 * cipher more than once and thus leak information
1623 * (VU#958563). The way we do this is not to take any
1624 * decisions on the basis of anything we've decrypted until
1625 * we've verified it with a MAC. That includes the packet
1626 * length, so we just read data and check the MAC repeatedly,
1627 * and when the MAC passes, see if the length we've got is
1630 * This defence is unnecessary in OpenSSH ETM mode, because
1631 * the whole point of ETM mode is that the attacker can't
1632 * tweak the ciphertext stream at all without the MAC
1633 * detecting it before we decrypt anything.
1636 /* May as well allocate the whole lot now. */
1637 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1640 /* Read an amount corresponding to the MAC. */
1641 for (st->i = 0; st->i < st->maclen; st->i++) {
1642 while ((*datalen) == 0)
1644 st->pktin->data[st->i] = *(*data)++;
1650 unsigned char seq[4];
1651 ssh->scmac->start(ssh->sc_mac_ctx);
1652 PUT_32BIT(seq, st->incoming_sequence);
1653 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1656 for (;;) { /* Once around this loop per cipher block. */
1657 /* Read another cipher-block's worth, and tack it onto the end. */
1658 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1659 while ((*datalen) == 0)
1661 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1664 /* Decrypt one more block (a little further back in the stream). */
1665 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1666 st->pktin->data + st->packetlen,
1668 /* Feed that block to the MAC. */
1669 ssh->scmac->bytes(ssh->sc_mac_ctx,
1670 st->pktin->data + st->packetlen, st->cipherblk);
1671 st->packetlen += st->cipherblk;
1672 /* See if that gives us a valid packet. */
1673 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1674 st->pktin->data + st->packetlen) &&
1675 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1678 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1679 bombout(("No valid incoming packet found"));
1680 ssh_free_packet(st->pktin);
1684 st->pktin->maxlen = st->packetlen + st->maclen;
1685 st->pktin->data = sresize(st->pktin->data,
1686 st->pktin->maxlen + APIEXTRA,
1688 } else if (ssh->scmac && ssh->scmac_etm) {
1689 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1692 * OpenSSH encrypt-then-MAC mode: the packet length is
1693 * unencrypted, unless the cipher supports length encryption.
1695 for (st->i = st->len = 0; st->i < 4; st->i++) {
1696 while ((*datalen) == 0)
1698 st->pktin->data[st->i] = *(*data)++;
1701 /* Cipher supports length decryption, so do it */
1702 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1703 /* Keep the packet the same though, so the MAC passes */
1704 unsigned char len[4];
1705 memcpy(len, st->pktin->data, 4);
1706 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1707 st->len = toint(GET_32BIT(len));
1709 st->len = toint(GET_32BIT(st->pktin->data));
1713 * _Completely_ silly lengths should be stomped on before they
1714 * do us any more damage.
1716 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1717 st->len % st->cipherblk != 0) {
1718 bombout(("Incoming packet length field was garbled"));
1719 ssh_free_packet(st->pktin);
1724 * So now we can work out the total packet length.
1726 st->packetlen = st->len + 4;
1729 * Allocate memory for the rest of the packet.
1731 st->pktin->maxlen = st->packetlen + st->maclen;
1732 st->pktin->data = sresize(st->pktin->data,
1733 st->pktin->maxlen + APIEXTRA,
1737 * Read the remainder of the packet.
1739 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1740 while ((*datalen) == 0)
1742 st->pktin->data[st->i] = *(*data)++;
1750 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1751 st->len + 4, st->incoming_sequence)) {
1752 bombout(("Incorrect MAC received on packet"));
1753 ssh_free_packet(st->pktin);
1757 /* Decrypt everything between the length field and the MAC. */
1759 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1760 st->pktin->data + 4,
1763 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1766 * Acquire and decrypt the first block of the packet. This will
1767 * contain the length and padding details.
1769 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1770 while ((*datalen) == 0)
1772 st->pktin->data[st->i] = *(*data)++;
1777 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1778 st->pktin->data, st->cipherblk);
1781 * Now get the length figure.
1783 st->len = toint(GET_32BIT(st->pktin->data));
1786 * _Completely_ silly lengths should be stomped on before they
1787 * do us any more damage.
1789 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1790 (st->len + 4) % st->cipherblk != 0) {
1791 bombout(("Incoming packet was garbled on decryption"));
1792 ssh_free_packet(st->pktin);
1797 * So now we can work out the total packet length.
1799 st->packetlen = st->len + 4;
1802 * Allocate memory for the rest of the packet.
1804 st->pktin->maxlen = st->packetlen + st->maclen;
1805 st->pktin->data = sresize(st->pktin->data,
1806 st->pktin->maxlen + APIEXTRA,
1810 * Read and decrypt the remainder of the packet.
1812 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1814 while ((*datalen) == 0)
1816 st->pktin->data[st->i] = *(*data)++;
1819 /* Decrypt everything _except_ the MAC. */
1821 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1822 st->pktin->data + st->cipherblk,
1823 st->packetlen - st->cipherblk);
1829 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1830 st->len + 4, st->incoming_sequence)) {
1831 bombout(("Incorrect MAC received on packet"));
1832 ssh_free_packet(st->pktin);
1836 /* Get and sanity-check the amount of random padding. */
1837 st->pad = st->pktin->data[4];
1838 if (st->pad < 4 || st->len - st->pad < 1) {
1839 bombout(("Invalid padding length on received packet"));
1840 ssh_free_packet(st->pktin);
1844 * This enables us to deduce the payload length.
1846 st->payload = st->len - st->pad - 1;
1848 st->pktin->length = st->payload + 5;
1849 st->pktin->encrypted_len = st->packetlen;
1851 st->pktin->sequence = st->incoming_sequence++;
1853 st->pktin->length = st->packetlen - st->pad;
1854 assert(st->pktin->length >= 0);
1857 * Decompress packet payload.
1860 unsigned char *newpayload;
1863 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1864 st->pktin->data + 5, st->pktin->length - 5,
1865 &newpayload, &newlen)) {
1866 if (st->pktin->maxlen < newlen + 5) {
1867 st->pktin->maxlen = newlen + 5;
1868 st->pktin->data = sresize(st->pktin->data,
1869 st->pktin->maxlen + APIEXTRA,
1872 st->pktin->length = 5 + newlen;
1873 memcpy(st->pktin->data + 5, newpayload, newlen);
1879 * RFC 4253 doesn't explicitly say that completely empty packets
1880 * with no type byte are forbidden, so treat them as deserving
1881 * an SSH_MSG_UNIMPLEMENTED.
1883 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1884 ssh2_msg_something_unimplemented(ssh, st->pktin);
1888 * pktin->body and pktin->length should identify the semantic
1889 * content of the packet, excluding the initial type byte.
1891 st->pktin->type = st->pktin->data[5];
1892 st->pktin->body = st->pktin->data + 6;
1893 st->pktin->length -= 6;
1894 assert(st->pktin->length >= 0); /* one last double-check */
1897 ssh2_log_incoming_packet(ssh, st->pktin);
1899 st->pktin->savedpos = 0;
1901 crFinish(st->pktin);
1904 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1905 const unsigned char **data,
1908 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1910 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1913 * Read the packet length field.
1915 for (st->i = 0; st->i < 4; st->i++) {
1916 while ((*datalen) == 0)
1918 st->length[st->i] = *(*data)++;
1922 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1923 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1924 bombout(("Invalid packet length received"));
1928 st->pktin = ssh_new_packet();
1929 st->pktin->data = snewn(st->packetlen, unsigned char);
1931 st->pktin->encrypted_len = st->packetlen;
1933 st->pktin->sequence = st->incoming_sequence++;
1936 * Read the remainder of the packet.
1938 for (st->i = 0; st->i < st->packetlen; st->i++) {
1939 while ((*datalen) == 0)
1941 st->pktin->data[st->i] = *(*data)++;
1946 * pktin->body and pktin->length should identify the semantic
1947 * content of the packet, excluding the initial type byte.
1949 st->pktin->type = st->pktin->data[0];
1950 st->pktin->body = st->pktin->data + 1;
1951 st->pktin->length = st->packetlen - 1;
1954 * Log incoming packet, possibly omitting sensitive fields.
1957 ssh2_log_incoming_packet(ssh, st->pktin);
1959 st->pktin->savedpos = 0;
1961 crFinish(st->pktin);
1964 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1966 int pad, biglen, i, pktoffs;
1970 * XXX various versions of SC (including 8.8.4) screw up the
1971 * register allocation in this function and use the same register
1972 * (D6) for len and as a temporary, with predictable results. The
1973 * following sledgehammer prevents this.
1980 ssh1_log_outgoing_packet(ssh, pkt);
1982 if (ssh->v1_compressing) {
1983 unsigned char *compblk;
1985 zlib_compress_block(ssh->cs_comp_ctx,
1986 pkt->data + 12, pkt->length - 12,
1987 &compblk, &complen);
1988 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1989 memcpy(pkt->data + 12, compblk, complen);
1991 pkt->length = complen + 12;
1994 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1996 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1997 pad = 8 - (len % 8);
1999 biglen = len + pad; /* len(padding+type+data+CRC) */
2001 for (i = pktoffs; i < 4+8; i++)
2002 pkt->data[i] = random_byte();
2003 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
2004 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
2005 PUT_32BIT(pkt->data + pktoffs, len);
2008 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
2009 pkt->data + pktoffs + 4, biglen);
2011 if (offset_p) *offset_p = pktoffs;
2012 return biglen + 4; /* len(length+padding+type+data+CRC) */
2015 static int s_write(Ssh ssh, void *data, int len)
2018 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
2019 0, NULL, NULL, 0, NULL);
2022 return sk_write(ssh->s, (char *)data, len);
2025 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2027 int len, backlog, offset;
2028 len = s_wrpkt_prepare(ssh, pkt, &offset);
2029 backlog = s_write(ssh, pkt->data + offset, len);
2030 if (backlog > SSH_MAX_BACKLOG)
2031 ssh_throttle_all(ssh, 1, backlog);
2032 ssh_free_packet(pkt);
2035 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2038 len = s_wrpkt_prepare(ssh, pkt, &offset);
2039 if (ssh->deferred_len + len > ssh->deferred_size) {
2040 ssh->deferred_size = ssh->deferred_len + len + 128;
2041 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2045 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2046 pkt->data + offset, len);
2047 ssh->deferred_len += len;
2048 ssh_free_packet(pkt);
2052 * Construct a SSH-1 packet with the specified contents.
2053 * (This all-at-once interface used to be the only one, but now SSH-1
2054 * packets can also be constructed incrementally.)
2056 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2062 pkt = ssh1_pkt_init(pkttype);
2064 while ((argtype = va_arg(ap, int)) != PKT_END) {
2065 unsigned char *argp, argchar;
2067 unsigned long argint;
2070 /* Actual fields in the packet */
2072 argint = va_arg(ap, int);
2073 ssh_pkt_adduint32(pkt, argint);
2076 argchar = (unsigned char) va_arg(ap, int);
2077 ssh_pkt_addbyte(pkt, argchar);
2080 argp = va_arg(ap, unsigned char *);
2081 arglen = va_arg(ap, int);
2082 ssh_pkt_adddata(pkt, argp, arglen);
2085 sargp = va_arg(ap, char *);
2086 ssh_pkt_addstring(pkt, sargp);
2089 bn = va_arg(ap, Bignum);
2090 ssh1_pkt_addmp(pkt, bn);
2098 static void send_packet(Ssh ssh, int pkttype, ...)
2102 va_start(ap, pkttype);
2103 pkt = construct_packet(ssh, pkttype, ap);
2108 static void defer_packet(Ssh ssh, int pkttype, ...)
2112 va_start(ap, pkttype);
2113 pkt = construct_packet(ssh, pkttype, ap);
2115 s_wrpkt_defer(ssh, pkt);
2118 static int ssh_versioncmp(const char *a, const char *b)
2121 unsigned long av, bv;
2123 av = strtoul(a, &ae, 10);
2124 bv = strtoul(b, &be, 10);
2126 return (av < bv ? -1 : +1);
2131 av = strtoul(ae, &ae, 10);
2132 bv = strtoul(be, &be, 10);
2134 return (av < bv ? -1 : +1);
2139 * Utility routines for putting an SSH-protocol `string' and
2140 * `uint32' into a hash state.
2142 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2144 unsigned char lenblk[4];
2145 PUT_32BIT(lenblk, len);
2146 h->bytes(s, lenblk, 4);
2147 h->bytes(s, str, len);
2150 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2152 unsigned char intblk[4];
2153 PUT_32BIT(intblk, i);
2154 h->bytes(s, intblk, 4);
2158 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2160 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2162 if (pkt->maxlen < length) {
2163 unsigned char *body = pkt->body;
2164 int offset = body ? body - pkt->data : 0;
2165 pkt->maxlen = length + 256;
2166 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2167 if (body) pkt->body = pkt->data + offset;
2170 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2173 ssh_pkt_ensure(pkt, pkt->length);
2174 memcpy(pkt->data + pkt->length - len, data, len);
2176 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2178 ssh_pkt_adddata(pkt, &byte, 1);
2180 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2182 ssh_pkt_adddata(pkt, &value, 1);
2184 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2187 PUT_32BIT(x, value);
2188 ssh_pkt_adddata(pkt, x, 4);
2190 static void ssh_pkt_addstring_start(struct Packet *pkt)
2192 ssh_pkt_adduint32(pkt, 0);
2193 pkt->savedpos = pkt->length;
2195 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2198 ssh_pkt_adddata(pkt, data, len);
2199 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2201 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2203 ssh_pkt_addstring_data(pkt, data, strlen(data));
2205 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2207 ssh_pkt_addstring_start(pkt);
2208 ssh_pkt_addstring_str(pkt, data);
2210 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2212 int len = ssh1_bignum_length(b);
2213 unsigned char *data = snewn(len, unsigned char);
2214 (void) ssh1_write_bignum(data, b);
2215 ssh_pkt_adddata(pkt, data, len);
2218 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2221 int i, n = (bignum_bitcount(b) + 7) / 8;
2222 p = snewn(n + 1, unsigned char);
2224 for (i = 1; i <= n; i++)
2225 p[i] = bignum_byte(b, n - i);
2227 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2229 memmove(p, p + i, n + 1 - i);
2233 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2237 p = ssh2_mpint_fmt(b, &len);
2238 ssh_pkt_addstring_start(pkt);
2239 ssh_pkt_addstring_data(pkt, (char *)p, len);
2243 static struct Packet *ssh1_pkt_init(int pkt_type)
2245 struct Packet *pkt = ssh_new_packet();
2246 pkt->length = 4 + 8; /* space for length + max padding */
2247 ssh_pkt_addbyte(pkt, pkt_type);
2248 pkt->body = pkt->data + pkt->length;
2249 pkt->type = pkt_type;
2250 pkt->downstream_id = 0;
2251 pkt->additional_log_text = NULL;
2255 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2256 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2257 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2258 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2259 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2260 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2261 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2262 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2263 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2265 static struct Packet *ssh2_pkt_init(int pkt_type)
2267 struct Packet *pkt = ssh_new_packet();
2268 pkt->length = 5; /* space for packet length + padding length */
2270 pkt->type = pkt_type;
2271 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2272 pkt->body = pkt->data + pkt->length; /* after packet type */
2273 pkt->downstream_id = 0;
2274 pkt->additional_log_text = NULL;
2279 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2280 * put the MAC on it. Final packet, ready to be sent, is stored in
2281 * pkt->data. Total length is returned.
2283 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2285 int cipherblk, maclen, padding, unencrypted_prefix, i;
2288 ssh2_log_outgoing_packet(ssh, pkt);
2290 if (ssh->bare_connection) {
2292 * Trivial packet construction for the bare connection
2295 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2296 pkt->body = pkt->data + 1;
2297 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2298 return pkt->length - 1;
2302 * Compress packet payload.
2305 unsigned char *newpayload;
2308 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2310 &newpayload, &newlen)) {
2312 ssh2_pkt_adddata(pkt, newpayload, newlen);
2318 * Add padding. At least four bytes, and must also bring total
2319 * length (minus MAC) up to a multiple of the block size.
2320 * If pkt->forcepad is set, make sure the packet is at least that size
2323 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2324 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2326 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2327 if (pkt->length + padding < pkt->forcepad)
2328 padding = pkt->forcepad - pkt->length;
2330 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2332 assert(padding <= 255);
2333 maclen = ssh->csmac ? ssh->csmac->len : 0;
2334 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2335 pkt->data[4] = padding;
2336 for (i = 0; i < padding; i++)
2337 pkt->data[pkt->length + i] = random_byte();
2338 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2340 /* Encrypt length if the scheme requires it */
2341 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2342 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2343 ssh->v2_outgoing_sequence);
2346 if (ssh->csmac && ssh->csmac_etm) {
2348 * OpenSSH-defined encrypt-then-MAC protocol.
2351 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2352 pkt->data + 4, pkt->length + padding - 4);
2353 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2354 pkt->length + padding,
2355 ssh->v2_outgoing_sequence);
2358 * SSH-2 standard protocol.
2361 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2362 pkt->length + padding,
2363 ssh->v2_outgoing_sequence);
2365 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2366 pkt->data, pkt->length + padding);
2369 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2370 pkt->encrypted_len = pkt->length + padding;
2372 /* Ready-to-send packet starts at pkt->data. We return length. */
2373 pkt->body = pkt->data;
2374 return pkt->length + padding + maclen;
2378 * Routines called from the main SSH code to send packets. There
2379 * are quite a few of these, because we have two separate
2380 * mechanisms for delaying the sending of packets:
2382 * - In order to send an IGNORE message and a password message in
2383 * a single fixed-length blob, we require the ability to
2384 * concatenate the encrypted forms of those two packets _into_ a
2385 * single blob and then pass it to our <network.h> transport
2386 * layer in one go. Hence, there's a deferment mechanism which
2387 * works after packet encryption.
2389 * - In order to avoid sending any connection-layer messages
2390 * during repeat key exchange, we have to queue up any such
2391 * outgoing messages _before_ they are encrypted (and in
2392 * particular before they're allocated sequence numbers), and
2393 * then send them once we've finished.
2395 * I call these mechanisms `defer' and `queue' respectively, so as
2396 * to distinguish them reasonably easily.
2398 * The functions send_noqueue() and defer_noqueue() free the packet
2399 * structure they are passed. Every outgoing packet goes through
2400 * precisely one of these functions in its life; packets passed to
2401 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2402 * these or get queued, and then when the queue is later emptied
2403 * the packets are all passed to defer_noqueue().
2405 * When using a CBC-mode cipher, it's necessary to ensure that an
2406 * attacker can't provide data to be encrypted using an IV that they
2407 * know. We ensure this by prefixing each packet that might contain
2408 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2409 * mechanism, so in this case send_noqueue() ends up redirecting to
2410 * defer_noqueue(). If you don't like this inefficiency, don't use
2414 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2415 static void ssh_pkt_defersend(Ssh);
2418 * Send an SSH-2 packet immediately, without queuing or deferring.
2420 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2424 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2425 /* We need to send two packets, so use the deferral mechanism. */
2426 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2427 ssh_pkt_defersend(ssh);
2430 len = ssh2_pkt_construct(ssh, pkt);
2431 backlog = s_write(ssh, pkt->body, len);
2432 if (backlog > SSH_MAX_BACKLOG)
2433 ssh_throttle_all(ssh, 1, backlog);
2435 ssh->outgoing_data_size += pkt->encrypted_len;
2436 if (!ssh->kex_in_progress &&
2437 !ssh->bare_connection &&
2438 ssh->max_data_size != 0 &&
2439 ssh->outgoing_data_size > ssh->max_data_size)
2440 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2442 ssh_free_packet(pkt);
2446 * Defer an SSH-2 packet.
2448 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2451 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2452 ssh->deferred_len == 0 && !noignore &&
2453 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2455 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2456 * get encrypted with a known IV.
2458 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2459 ssh2_pkt_addstring_start(ipkt);
2460 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2462 len = ssh2_pkt_construct(ssh, pkt);
2463 if (ssh->deferred_len + len > ssh->deferred_size) {
2464 ssh->deferred_size = ssh->deferred_len + len + 128;
2465 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2469 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2470 ssh->deferred_len += len;
2471 ssh->deferred_data_size += pkt->encrypted_len;
2472 ssh_free_packet(pkt);
2476 * Queue an SSH-2 packet.
2478 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2480 assert(ssh->queueing);
2482 if (ssh->queuelen >= ssh->queuesize) {
2483 ssh->queuesize = ssh->queuelen + 32;
2484 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2487 ssh->queue[ssh->queuelen++] = pkt;
2491 * Either queue or send a packet, depending on whether queueing is
2494 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2497 ssh2_pkt_queue(ssh, pkt);
2499 ssh2_pkt_send_noqueue(ssh, pkt);
2503 * Either queue or defer a packet, depending on whether queueing is
2506 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2509 ssh2_pkt_queue(ssh, pkt);
2511 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2515 * Send the whole deferred data block constructed by
2516 * ssh2_pkt_defer() or SSH-1's defer_packet().
2518 * The expected use of the defer mechanism is that you call
2519 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2520 * not currently queueing, this simply sets up deferred_send_data
2521 * and then sends it. If we _are_ currently queueing, the calls to
2522 * ssh2_pkt_defer() put the deferred packets on to the queue
2523 * instead, and therefore ssh_pkt_defersend() has no deferred data
2524 * to send. Hence, there's no need to make it conditional on
2527 static void ssh_pkt_defersend(Ssh ssh)
2530 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2531 ssh->deferred_len = ssh->deferred_size = 0;
2532 sfree(ssh->deferred_send_data);
2533 ssh->deferred_send_data = NULL;
2534 if (backlog > SSH_MAX_BACKLOG)
2535 ssh_throttle_all(ssh, 1, backlog);
2537 if (ssh->version == 2) {
2538 ssh->outgoing_data_size += ssh->deferred_data_size;
2539 ssh->deferred_data_size = 0;
2540 if (!ssh->kex_in_progress &&
2541 !ssh->bare_connection &&
2542 ssh->max_data_size != 0 &&
2543 ssh->outgoing_data_size > ssh->max_data_size)
2544 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2549 * Send a packet whose length needs to be disguised (typically
2550 * passwords or keyboard-interactive responses).
2552 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2558 * The simplest way to do this is to adjust the
2559 * variable-length padding field in the outgoing packet.
2561 * Currently compiled out, because some Cisco SSH servers
2562 * don't like excessively padded packets (bah, why's it
2565 pkt->forcepad = padsize;
2566 ssh2_pkt_send(ssh, pkt);
2571 * If we can't do that, however, an alternative approach is
2572 * to use the pkt_defer mechanism to bundle the packet
2573 * tightly together with an SSH_MSG_IGNORE such that their
2574 * combined length is a constant. So first we construct the
2575 * final form of this packet and defer its sending.
2577 ssh2_pkt_defer(ssh, pkt);
2580 * Now construct an SSH_MSG_IGNORE which includes a string
2581 * that's an exact multiple of the cipher block size. (If
2582 * the cipher is NULL so that the block size is
2583 * unavailable, we don't do this trick at all, because we
2584 * gain nothing by it.)
2586 if (ssh->cscipher &&
2587 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2590 stringlen = (256 - ssh->deferred_len);
2591 stringlen += ssh->cscipher->blksize - 1;
2592 stringlen -= (stringlen % ssh->cscipher->blksize);
2595 * Temporarily disable actual compression, so we
2596 * can guarantee to get this string exactly the
2597 * length we want it. The compression-disabling
2598 * routine should return an integer indicating how
2599 * many bytes we should adjust our string length
2603 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2605 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2606 ssh2_pkt_addstring_start(pkt);
2607 for (i = 0; i < stringlen; i++) {
2608 char c = (char) random_byte();
2609 ssh2_pkt_addstring_data(pkt, &c, 1);
2611 ssh2_pkt_defer(ssh, pkt);
2613 ssh_pkt_defersend(ssh);
2618 * Send all queued SSH-2 packets. We send them by means of
2619 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2620 * packets that needed to be lumped together.
2622 static void ssh2_pkt_queuesend(Ssh ssh)
2626 assert(!ssh->queueing);
2628 for (i = 0; i < ssh->queuelen; i++)
2629 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2632 ssh_pkt_defersend(ssh);
2636 void bndebug(char *string, Bignum b)
2640 p = ssh2_mpint_fmt(b, &len);
2641 debug(("%s", string));
2642 for (i = 0; i < len; i++)
2643 debug((" %02x", p[i]));
2649 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2653 p = ssh2_mpint_fmt(b, &len);
2654 hash_string(h, s, p, len);
2659 * Packet decode functions for both SSH-1 and SSH-2.
2661 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2663 unsigned long value;
2664 if (pkt->length - pkt->savedpos < 4)
2665 return 0; /* arrgh, no way to decline (FIXME?) */
2666 value = GET_32BIT(pkt->body + pkt->savedpos);
2670 static int ssh2_pkt_getbool(struct Packet *pkt)
2672 unsigned long value;
2673 if (pkt->length - pkt->savedpos < 1)
2674 return 0; /* arrgh, no way to decline (FIXME?) */
2675 value = pkt->body[pkt->savedpos] != 0;
2679 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2684 if (pkt->length - pkt->savedpos < 4)
2686 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2691 if (pkt->length - pkt->savedpos < *length)
2693 *p = (char *)(pkt->body + pkt->savedpos);
2694 pkt->savedpos += *length;
2696 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2698 if (pkt->length - pkt->savedpos < length)
2700 pkt->savedpos += length;
2701 return pkt->body + (pkt->savedpos - length);
2703 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2704 const unsigned char **keystr)
2708 j = makekey(pkt->body + pkt->savedpos,
2709 pkt->length - pkt->savedpos,
2716 assert(pkt->savedpos < pkt->length);
2720 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2725 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2726 pkt->length - pkt->savedpos, &b);
2734 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2740 ssh_pkt_getstring(pkt, &p, &length);
2745 b = bignum_from_bytes((unsigned char *)p, length);
2750 * Helper function to add an SSH-2 signature blob to a packet.
2751 * Expects to be shown the public key blob as well as the signature
2752 * blob. Normally works just like ssh2_pkt_addstring, but will
2753 * fiddle with the signature packet if necessary for
2754 * BUG_SSH2_RSA_PADDING.
2756 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2757 void *pkblob_v, int pkblob_len,
2758 void *sigblob_v, int sigblob_len)
2760 unsigned char *pkblob = (unsigned char *)pkblob_v;
2761 unsigned char *sigblob = (unsigned char *)sigblob_v;
2763 /* dmemdump(pkblob, pkblob_len); */
2764 /* dmemdump(sigblob, sigblob_len); */
2767 * See if this is in fact an ssh-rsa signature and a buggy
2768 * server; otherwise we can just do this the easy way.
2770 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2771 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2772 int pos, len, siglen;
2775 * Find the byte length of the modulus.
2778 pos = 4+7; /* skip over "ssh-rsa" */
2779 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2780 if (len < 0 || len > pkblob_len - pos - 4)
2782 pos += 4 + len; /* skip over exponent */
2783 if (pkblob_len - pos < 4)
2785 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2786 if (len < 0 || len > pkblob_len - pos - 4)
2788 pos += 4; /* find modulus itself */
2789 while (len > 0 && pkblob[pos] == 0)
2791 /* debug(("modulus length is %d\n", len)); */
2794 * Now find the signature integer.
2796 pos = 4+7; /* skip over "ssh-rsa" */
2797 if (sigblob_len < pos+4)
2799 siglen = toint(GET_32BIT(sigblob+pos));
2800 if (siglen != sigblob_len - pos - 4)
2802 /* debug(("signature length is %d\n", siglen)); */
2804 if (len != siglen) {
2805 unsigned char newlen[4];
2806 ssh2_pkt_addstring_start(pkt);
2807 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2808 /* dmemdump(sigblob, pos); */
2809 pos += 4; /* point to start of actual sig */
2810 PUT_32BIT(newlen, len);
2811 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2812 /* dmemdump(newlen, 4); */
2814 while (len-- > siglen) {
2815 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2816 /* dmemdump(newlen, 1); */
2818 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2819 /* dmemdump(sigblob+pos, siglen); */
2823 /* Otherwise fall through and do it the easy way. We also come
2824 * here as a fallback if we discover above that the key blob
2825 * is misformatted in some way. */
2829 ssh2_pkt_addstring_start(pkt);
2830 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2834 * Examine the remote side's version string and compare it against
2835 * a list of known buggy implementations.
2837 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2839 char *imp; /* pointer to implementation part */
2841 imp += strcspn(imp, "-");
2843 imp += strcspn(imp, "-");
2846 ssh->remote_bugs = 0;
2849 * General notes on server version strings:
2850 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2851 * here -- in particular, we've heard of one that's perfectly happy
2852 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2853 * so we can't distinguish them.
2855 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2856 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2857 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2858 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2859 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2860 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2862 * These versions don't support SSH1_MSG_IGNORE, so we have
2863 * to use a different defence against password length
2866 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2867 logevent("We believe remote version has SSH-1 ignore bug");
2870 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2871 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2872 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2874 * These versions need a plain password sent; they can't
2875 * handle having a null and a random length of data after
2878 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2879 logevent("We believe remote version needs a plain SSH-1 password");
2882 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2883 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2884 (!strcmp(imp, "Cisco-1.25")))) {
2886 * These versions apparently have no clue whatever about
2887 * RSA authentication and will panic and die if they see
2888 * an AUTH_RSA message.
2890 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2891 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2894 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2895 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2896 !wc_match("* VShell", imp) &&
2897 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2898 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2899 wc_match("2.1 *", imp)))) {
2901 * These versions have the HMAC bug.
2903 ssh->remote_bugs |= BUG_SSH2_HMAC;
2904 logevent("We believe remote version has SSH-2 HMAC bug");
2907 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2908 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2909 !wc_match("* VShell", imp) &&
2910 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2912 * These versions have the key-derivation bug (failing to
2913 * include the literal shared secret in the hashes that
2914 * generate the keys).
2916 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2917 logevent("We believe remote version has SSH-2 key-derivation bug");
2920 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2921 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2922 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2923 wc_match("OpenSSH_3.[0-2]*", imp) ||
2924 wc_match("mod_sftp/0.[0-8]*", imp) ||
2925 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2927 * These versions have the SSH-2 RSA padding bug.
2929 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2930 logevent("We believe remote version has SSH-2 RSA padding bug");
2933 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2934 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2935 wc_match("OpenSSH_2.[0-2]*", imp))) {
2937 * These versions have the SSH-2 session-ID bug in
2938 * public-key authentication.
2940 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2941 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2944 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2945 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2946 (wc_match("DigiSSH_2.0", imp) ||
2947 wc_match("OpenSSH_2.[0-4]*", imp) ||
2948 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2949 wc_match("Sun_SSH_1.0", imp) ||
2950 wc_match("Sun_SSH_1.0.1", imp) ||
2951 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2952 wc_match("WeOnlyDo-*", imp)))) {
2954 * These versions have the SSH-2 rekey bug.
2956 ssh->remote_bugs |= BUG_SSH2_REKEY;
2957 logevent("We believe remote version has SSH-2 rekey bug");
2960 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2961 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2962 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2963 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2965 * This version ignores our makpkt and needs to be throttled.
2967 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2968 logevent("We believe remote version ignores SSH-2 maximum packet size");
2971 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2973 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2974 * none detected automatically.
2976 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2977 logevent("We believe remote version has SSH-2 ignore bug");
2980 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2981 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2982 (wc_match("OpenSSH_2.[235]*", imp)))) {
2984 * These versions only support the original (pre-RFC4419)
2985 * SSH-2 GEX request, and disconnect with a protocol error if
2986 * we use the newer version.
2988 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2989 logevent("We believe remote version has outdated SSH-2 GEX");
2992 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2994 * Servers that don't support our winadj request for one
2995 * reason or another. Currently, none detected automatically.
2997 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2998 logevent("We believe remote version has winadj bug");
3001 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
3002 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
3003 (wc_match("OpenSSH_[2-5].*", imp) ||
3004 wc_match("OpenSSH_6.[0-6]*", imp) ||
3005 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
3006 wc_match("dropbear_0.5[01]*", imp)))) {
3008 * These versions have the SSH-2 channel request bug.
3009 * OpenSSH 6.7 and above do not:
3010 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
3011 * dropbear_0.52 and above do not:
3012 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
3014 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
3015 logevent("We believe remote version has SSH-2 channel request bug");
3020 * The `software version' part of an SSH version string is required
3021 * to contain no spaces or minus signs.
3023 static void ssh_fix_verstring(char *str)
3025 /* Eat "<protoversion>-". */
3026 while (*str && *str != '-') str++;
3027 assert(*str == '-'); str++;
3029 /* Convert minus signs and spaces in the remaining string into
3032 if (*str == '-' || *str == ' ')
3039 * Send an appropriate SSH version string.
3041 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3045 if (ssh->version == 2) {
3047 * Construct a v2 version string.
3049 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3052 * Construct a v1 version string.
3054 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3055 verstring = dupprintf("SSH-%s-%s\012",
3056 (ssh_versioncmp(svers, "1.5") <= 0 ?
3061 ssh_fix_verstring(verstring + strlen(protoname));
3063 /* FUZZING make PuTTY insecure, so make live use difficult. */
3067 if (ssh->version == 2) {
3070 * Record our version string.
3072 len = strcspn(verstring, "\015\012");
3073 ssh->v_c = snewn(len + 1, char);
3074 memcpy(ssh->v_c, verstring, len);
3078 logeventf(ssh, "We claim version: %.*s",
3079 strcspn(verstring, "\015\012"), verstring);
3080 s_write(ssh, verstring, strlen(verstring));
3084 static int do_ssh_init(Ssh ssh, unsigned char c)
3086 static const char protoname[] = "SSH-";
3088 struct do_ssh_init_state {
3097 crState(do_ssh_init_state);
3101 /* Search for a line beginning with the protocol name prefix in
3104 for (s->i = 0; protoname[s->i]; s->i++) {
3105 if ((char)c != protoname[s->i]) goto no;
3115 ssh->session_started = TRUE;
3117 s->vstrsize = sizeof(protoname) + 16;
3118 s->vstring = snewn(s->vstrsize, char);
3119 strcpy(s->vstring, protoname);
3120 s->vslen = strlen(protoname);
3123 if (s->vslen >= s->vstrsize - 1) {
3125 s->vstring = sresize(s->vstring, s->vstrsize, char);
3127 s->vstring[s->vslen++] = c;
3130 s->version[s->i] = '\0';
3132 } else if (s->i < sizeof(s->version) - 1)
3133 s->version[s->i++] = c;
3134 } else if (c == '\012')
3136 crReturn(1); /* get another char */
3139 ssh->agentfwd_enabled = FALSE;
3140 ssh->rdpkt2_state.incoming_sequence = 0;
3142 s->vstring[s->vslen] = 0;
3143 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3144 logeventf(ssh, "Server version: %s", s->vstring);
3145 ssh_detect_bugs(ssh, s->vstring);
3148 * Decide which SSH protocol version to support.
3151 /* Anything strictly below "2.0" means protocol 1 is supported. */
3152 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3153 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3154 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3156 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3158 bombout(("SSH protocol version 1 required by our configuration "
3159 "but not provided by server"));
3162 } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) {
3164 bombout(("SSH protocol version 2 required by our configuration "
3165 "but server only provides (old, insecure) SSH-1"));
3169 /* No longer support values 1 or 2 for CONF_sshprot */
3170 assert(!"Unexpected value for CONF_sshprot");
3173 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3178 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3180 /* Send the version string, if we haven't already */
3181 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3182 ssh_send_verstring(ssh, protoname, s->version);
3184 if (ssh->version == 2) {
3187 * Record their version string.
3189 len = strcspn(s->vstring, "\015\012");
3190 ssh->v_s = snewn(len + 1, char);
3191 memcpy(ssh->v_s, s->vstring, len);
3195 * Initialise SSH-2 protocol.
3197 ssh->protocol = ssh2_protocol;
3198 ssh2_protocol_setup(ssh);
3199 ssh->s_rdpkt = ssh2_rdpkt;
3202 * Initialise SSH-1 protocol.
3204 ssh->protocol = ssh1_protocol;
3205 ssh1_protocol_setup(ssh);
3206 ssh->s_rdpkt = ssh1_rdpkt;
3208 if (ssh->version == 2)
3209 do_ssh2_transport(ssh, NULL, -1, NULL);
3211 update_specials_menu(ssh->frontend);
3212 ssh->state = SSH_STATE_BEFORE_SIZE;
3213 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3220 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3223 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3224 * the ssh-connection part, extracted and given a trivial binary
3225 * packet protocol, so we replace 'SSH-' at the start with a new
3226 * name. In proper SSH style (though of course this part of the
3227 * proper SSH protocol _isn't_ subject to this kind of
3228 * DNS-domain-based extension), we define the new name in our
3231 static const char protoname[] =
3232 "SSHCONNECTION@putty.projects.tartarus.org-";
3234 struct do_ssh_connection_init_state {
3242 crState(do_ssh_connection_init_state);
3246 /* Search for a line beginning with the protocol name prefix in
3249 for (s->i = 0; protoname[s->i]; s->i++) {
3250 if ((char)c != protoname[s->i]) goto no;
3260 s->vstrsize = sizeof(protoname) + 16;
3261 s->vstring = snewn(s->vstrsize, char);
3262 strcpy(s->vstring, protoname);
3263 s->vslen = strlen(protoname);
3266 if (s->vslen >= s->vstrsize - 1) {
3268 s->vstring = sresize(s->vstring, s->vstrsize, char);
3270 s->vstring[s->vslen++] = c;
3273 s->version[s->i] = '\0';
3275 } else if (s->i < sizeof(s->version) - 1)
3276 s->version[s->i++] = c;
3277 } else if (c == '\012')
3279 crReturn(1); /* get another char */
3282 ssh->agentfwd_enabled = FALSE;
3283 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3285 s->vstring[s->vslen] = 0;
3286 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3287 logeventf(ssh, "Server version: %s", s->vstring);
3288 ssh_detect_bugs(ssh, s->vstring);
3291 * Decide which SSH protocol version to support. This is easy in
3292 * bare ssh-connection mode: only 2.0 is legal.
3294 if (ssh_versioncmp(s->version, "2.0") < 0) {
3295 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3298 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3299 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3305 logeventf(ssh, "Using bare ssh-connection protocol");
3307 /* Send the version string, if we haven't already */
3308 ssh_send_verstring(ssh, protoname, s->version);
3311 * Initialise bare connection protocol.
3313 ssh->protocol = ssh2_bare_connection_protocol;
3314 ssh2_bare_connection_protocol_setup(ssh);
3315 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3317 update_specials_menu(ssh->frontend);
3318 ssh->state = SSH_STATE_BEFORE_SIZE;
3319 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3322 * Get authconn (really just conn) under way.
3324 do_ssh2_authconn(ssh, NULL, 0, NULL);
3331 static void ssh_process_incoming_data(Ssh ssh,
3332 const unsigned char **data, int *datalen)
3334 struct Packet *pktin;
3336 pktin = ssh->s_rdpkt(ssh, data, datalen);
3338 ssh->protocol(ssh, NULL, 0, pktin);
3339 ssh_free_packet(pktin);
3343 static void ssh_queue_incoming_data(Ssh ssh,
3344 const unsigned char **data, int *datalen)
3346 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3351 static void ssh_process_queued_incoming_data(Ssh ssh)
3354 const unsigned char *data;
3357 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3358 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3362 while (!ssh->frozen && len > 0)
3363 ssh_process_incoming_data(ssh, &data, &len);
3366 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3370 static void ssh_set_frozen(Ssh ssh, int frozen)
3373 sk_set_frozen(ssh->s, frozen);
3374 ssh->frozen = frozen;
3377 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3379 /* Log raw data, if we're in that mode. */
3381 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3382 0, NULL, NULL, 0, NULL);
3384 crBegin(ssh->ssh_gotdata_crstate);
3387 * To begin with, feed the characters one by one to the
3388 * protocol initialisation / selection function do_ssh_init().
3389 * When that returns 0, we're done with the initial greeting
3390 * exchange and can move on to packet discipline.
3393 int ret; /* need not be kept across crReturn */
3395 crReturnV; /* more data please */
3396 ret = ssh->do_ssh_init(ssh, *data);
3404 * We emerge from that loop when the initial negotiation is
3405 * over and we have selected an s_rdpkt function. Now pass
3406 * everything to s_rdpkt, and then pass the resulting packets
3407 * to the proper protocol handler.
3411 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3413 ssh_queue_incoming_data(ssh, &data, &datalen);
3414 /* This uses up all data and cannot cause anything interesting
3415 * to happen; indeed, for anything to happen at all, we must
3416 * return, so break out. */
3418 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3419 /* This uses up some or all data, and may freeze the
3421 ssh_process_queued_incoming_data(ssh);
3423 /* This uses up some or all data, and may freeze the
3425 ssh_process_incoming_data(ssh, &data, &datalen);
3427 /* FIXME this is probably EBW. */
3428 if (ssh->state == SSH_STATE_CLOSED)
3431 /* We're out of data. Go and get some more. */
3437 static int ssh_do_close(Ssh ssh, int notify_exit)
3440 struct ssh_channel *c;
3442 ssh->state = SSH_STATE_CLOSED;
3443 expire_timer_context(ssh);
3448 notify_remote_exit(ssh->frontend);
3453 * Now we must shut down any port- and X-forwarded channels going
3454 * through this connection.
3456 if (ssh->channels) {
3457 while (NULL != (c = index234(ssh->channels, 0))) {
3460 x11_close(c->u.x11.xconn);
3463 case CHAN_SOCKDATA_DORMANT:
3464 pfd_close(c->u.pfd.pf);
3467 del234(ssh->channels, c); /* moving next one to index 0 */
3468 if (ssh->version == 2)
3469 bufchain_clear(&c->v.v2.outbuffer);
3474 * Go through port-forwardings, and close any associated
3475 * listening sockets.
3477 if (ssh->portfwds) {
3478 struct ssh_portfwd *pf;
3479 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3480 /* Dispose of any listening socket. */
3482 pfl_terminate(pf->local);
3483 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3486 freetree234(ssh->portfwds);
3487 ssh->portfwds = NULL;
3491 * Also stop attempting to connection-share.
3493 if (ssh->connshare) {
3494 sharestate_free(ssh->connshare);
3495 ssh->connshare = NULL;
3501 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3502 const char *error_msg, int error_code)
3504 Ssh ssh = (Ssh) plug;
3507 * While we're attempting connection sharing, don't loudly log
3508 * everything that happens. Real TCP connections need to be logged
3509 * when we _start_ trying to connect, because it might be ages
3510 * before they respond if something goes wrong; but connection
3511 * sharing is local and quick to respond, and it's sufficient to
3512 * simply wait and see whether it worked afterwards.
3515 if (!ssh->attempting_connshare)
3516 backend_socket_log(ssh->frontend, type, addr, port,
3517 error_msg, error_code, ssh->conf,
3518 ssh->session_started);
3521 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3522 const char *ds_err, const char *us_err)
3524 if (event == SHARE_NONE) {
3525 /* In this case, 'logtext' is an error message indicating a
3526 * reason why connection sharing couldn't be set up _at all_.
3527 * Failing that, ds_err and us_err indicate why we couldn't be
3528 * a downstream and an upstream respectively. */
3530 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3533 logeventf(ssh, "Could not set up connection sharing"
3534 " as downstream: %s", ds_err);
3536 logeventf(ssh, "Could not set up connection sharing"
3537 " as upstream: %s", us_err);
3539 } else if (event == SHARE_DOWNSTREAM) {
3540 /* In this case, 'logtext' is a local endpoint address */
3541 logeventf(ssh, "Using existing shared connection at %s", logtext);
3542 /* Also we should mention this in the console window to avoid
3543 * confusing users as to why this window doesn't behave the
3545 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3546 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3548 } else if (event == SHARE_UPSTREAM) {
3549 /* In this case, 'logtext' is a local endpoint address too */
3550 logeventf(ssh, "Sharing this connection at %s", logtext);
3554 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3557 Ssh ssh = (Ssh) plug;
3558 int need_notify = ssh_do_close(ssh, FALSE);
3561 if (!ssh->close_expected)
3562 error_msg = "Server unexpectedly closed network connection";
3564 error_msg = "Server closed network connection";
3567 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3571 notify_remote_exit(ssh->frontend);
3574 logevent(error_msg);
3575 if (!ssh->close_expected || !ssh->clean_exit)
3576 connection_fatal(ssh->frontend, "%s", error_msg);
3580 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3582 Ssh ssh = (Ssh) plug;
3583 ssh_gotdata(ssh, (unsigned char *)data, len);
3584 if (ssh->state == SSH_STATE_CLOSED) {
3585 ssh_do_close(ssh, TRUE);
3591 static void ssh_sent(Plug plug, int bufsize)
3593 Ssh ssh = (Ssh) plug;
3595 * If the send backlog on the SSH socket itself clears, we
3596 * should unthrottle the whole world if it was throttled.
3598 if (bufsize < SSH_MAX_BACKLOG)
3599 ssh_throttle_all(ssh, 0, bufsize);
3602 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3603 char **savedhost, int *savedport,
3606 char *loghost = conf_get_str(conf, CONF_loghost);
3608 *loghost_ret = loghost;
3614 tmphost = dupstr(loghost);
3615 *savedport = 22; /* default ssh port */
3618 * A colon suffix on the hostname string also lets us affect
3619 * savedport. (Unless there are multiple colons, in which case
3620 * we assume this is an unbracketed IPv6 literal.)
3622 colon = host_strrchr(tmphost, ':');
3623 if (colon && colon == host_strchr(tmphost, ':')) {
3626 *savedport = atoi(colon);
3629 *savedhost = host_strduptrim(tmphost);
3632 *savedhost = host_strduptrim(host);
3634 port = 22; /* default ssh port */
3639 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3645 random_ref(); /* platform may need this to determine share socket name */
3646 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3647 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3655 * Connect to specified host and port.
3656 * Returns an error message, or NULL on success.
3657 * Also places the canonical host name into `realhost'. It must be
3658 * freed by the caller.
3660 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3661 char **realhost, int nodelay, int keepalive)
3663 static const struct plug_function_table fn_table = {
3674 int addressfamily, sshprot;
3676 ssh_hostport_setup(host, port, ssh->conf,
3677 &ssh->savedhost, &ssh->savedport, &loghost);
3679 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3682 * Try connection-sharing, in case that means we don't open a
3683 * socket after all. ssh_connection_sharing_init will connect to a
3684 * previously established upstream if it can, and failing that,
3685 * establish a listening socket for _us_ to be the upstream. In
3686 * the latter case it will return NULL just as if it had done
3687 * nothing, because here we only need to care if we're a
3688 * downstream and need to do our connection setup differently.
3690 ssh->connshare = NULL;
3691 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3692 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3693 ssh->conf, ssh, &ssh->connshare);
3694 ssh->attempting_connshare = FALSE;
3695 if (ssh->s != NULL) {
3697 * We are a downstream.
3699 ssh->bare_connection = TRUE;
3700 ssh->do_ssh_init = do_ssh_connection_init;
3701 ssh->fullhostname = NULL;
3702 *realhost = dupstr(host); /* best we can do */
3705 * We're not a downstream, so open a normal socket.
3707 ssh->do_ssh_init = do_ssh_init;
3712 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3713 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3714 ssh->frontend, "SSH connection");
3715 if ((err = sk_addr_error(addr)) != NULL) {
3719 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3721 ssh->s = new_connection(addr, *realhost, port,
3722 0, 1, nodelay, keepalive,
3723 (Plug) ssh, ssh->conf);
3724 if ((err = sk_socket_error(ssh->s)) != NULL) {
3726 notify_remote_exit(ssh->frontend);
3732 * The SSH version number is always fixed (since we no longer support
3733 * fallback between versions), so set it now, and if it's SSH-2,
3734 * send the version string now too.
3736 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3737 assert(sshprot == 0 || sshprot == 3);
3741 if (sshprot == 3 && !ssh->bare_connection) {
3744 ssh_send_verstring(ssh, "SSH-", NULL);
3748 * loghost, if configured, overrides realhost.
3752 *realhost = dupstr(loghost);
3759 * Throttle or unthrottle the SSH connection.
3761 static void ssh_throttle_conn(Ssh ssh, int adjust)
3763 int old_count = ssh->conn_throttle_count;
3764 ssh->conn_throttle_count += adjust;
3765 assert(ssh->conn_throttle_count >= 0);
3766 if (ssh->conn_throttle_count && !old_count) {
3767 ssh_set_frozen(ssh, 1);
3768 } else if (!ssh->conn_throttle_count && old_count) {
3769 ssh_set_frozen(ssh, 0);
3774 * Throttle or unthrottle _all_ local data streams (for when sends
3775 * on the SSH connection itself back up).
3777 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3780 struct ssh_channel *c;
3782 if (enable == ssh->throttled_all)
3784 ssh->throttled_all = enable;
3785 ssh->overall_bufsize = bufsize;
3788 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3790 case CHAN_MAINSESSION:
3792 * This is treated separately, outside the switch.
3796 x11_override_throttle(c->u.x11.xconn, enable);
3799 /* Agent channels require no buffer management. */
3802 pfd_override_throttle(c->u.pfd.pf, enable);
3808 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3810 Ssh ssh = (Ssh) sshv;
3812 ssh->agent_response = reply;
3813 ssh->agent_response_len = replylen;
3815 if (ssh->version == 1)
3816 do_ssh1_login(ssh, NULL, -1, NULL);
3818 do_ssh2_authconn(ssh, NULL, -1, NULL);
3821 static void ssh_dialog_callback(void *sshv, int ret)
3823 Ssh ssh = (Ssh) sshv;
3825 ssh->user_response = ret;
3827 if (ssh->version == 1)
3828 do_ssh1_login(ssh, NULL, -1, NULL);
3830 do_ssh2_transport(ssh, NULL, -1, NULL);
3833 * This may have unfrozen the SSH connection, so do a
3836 ssh_process_queued_incoming_data(ssh);
3839 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3841 struct ssh_channel *c = (struct ssh_channel *)cv;
3842 const void *sentreply = reply;
3844 c->u.a.outstanding_requests--;
3846 /* Fake SSH_AGENT_FAILURE. */
3847 sentreply = "\0\0\0\1\5";
3850 ssh_send_channel_data(c, sentreply, replylen);
3854 * If we've already seen an incoming EOF but haven't sent an
3855 * outgoing one, this may be the moment to send it.
3857 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3858 sshfwd_write_eof(c);
3862 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3863 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3864 * => log `wire_reason'.
3866 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3867 const char *wire_reason,
3868 int code, int clean_exit)
3872 client_reason = wire_reason;
3874 error = dupprintf("Disconnected: %s", client_reason);
3876 error = dupstr("Disconnected");
3878 if (ssh->version == 1) {
3879 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3881 } else if (ssh->version == 2) {
3882 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3883 ssh2_pkt_adduint32(pktout, code);
3884 ssh2_pkt_addstring(pktout, wire_reason);
3885 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3886 ssh2_pkt_send_noqueue(ssh, pktout);
3889 ssh->close_expected = TRUE;
3890 ssh->clean_exit = clean_exit;
3891 ssh_closing((Plug)ssh, error, 0, 0);
3895 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3896 const struct ssh_signkey *ssh2keytype,
3899 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3900 return -1; /* no manual keys configured */
3905 * The fingerprint string we've been given will have things
3906 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3907 * narrow down to just the colon-separated hex block at the
3908 * end of the string.
3910 const char *p = strrchr(fingerprint, ' ');
3911 fingerprint = p ? p+1 : fingerprint;
3912 /* Quick sanity checks, including making sure it's in lowercase */
3913 assert(strlen(fingerprint) == 16*3 - 1);
3914 assert(fingerprint[2] == ':');
3915 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3917 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3919 return 1; /* success */
3924 * Construct the base64-encoded public key blob and see if
3927 unsigned char *binblob;
3929 int binlen, atoms, i;
3930 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3931 atoms = (binlen + 2) / 3;
3932 base64blob = snewn(atoms * 4 + 1, char);
3933 for (i = 0; i < atoms; i++)
3934 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3935 base64blob[atoms * 4] = '\0';
3937 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3940 return 1; /* success */
3949 * Handle the key exchange and user authentication phases.
3951 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3952 struct Packet *pktin)
3955 unsigned char cookie[8], *ptr;
3956 struct MD5Context md5c;
3957 struct do_ssh1_login_state {
3960 unsigned char *rsabuf;
3961 const unsigned char *keystr1, *keystr2;
3962 unsigned long supported_ciphers_mask, supported_auths_mask;
3963 int tried_publickey, tried_agent;
3964 int tis_auth_refused, ccard_auth_refused;
3965 unsigned char session_id[16];
3967 void *publickey_blob;
3968 int publickey_bloblen;
3969 char *publickey_comment;
3970 int privatekey_available, privatekey_encrypted;
3971 prompts_t *cur_prompt;
3974 unsigned char request[5], *response, *p;
3984 struct RSAKey servkey, hostkey;
3986 crState(do_ssh1_login_state);
3993 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3994 bombout(("Public key packet not received"));
3998 logevent("Received public keys");
4000 ptr = ssh_pkt_getdata(pktin, 8);
4002 bombout(("SSH-1 public key packet stopped before random cookie"));
4005 memcpy(cookie, ptr, 8);
4007 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
4008 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
4009 bombout(("Failed to read SSH-1 public keys from public key packet"));
4014 * Log the host key fingerprint.
4018 logevent("Host key fingerprint is:");
4019 strcpy(logmsg, " ");
4020 s->hostkey.comment = NULL;
4021 rsa_fingerprint(logmsg + strlen(logmsg),
4022 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4026 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4027 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4028 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4029 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4030 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4032 ssh->v1_local_protoflags =
4033 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4034 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4037 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4038 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4039 MD5Update(&md5c, cookie, 8);
4040 MD5Final(s->session_id, &md5c);
4042 for (i = 0; i < 32; i++)
4043 ssh->session_key[i] = random_byte();
4046 * Verify that the `bits' and `bytes' parameters match.
4048 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4049 s->servkey.bits > s->servkey.bytes * 8) {
4050 bombout(("SSH-1 public keys were badly formatted"));
4054 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4055 s->hostkey.bytes : s->servkey.bytes);
4057 s->rsabuf = snewn(s->len, unsigned char);
4060 * Verify the host key.
4064 * First format the key into a string.
4066 int len = rsastr_len(&s->hostkey);
4067 char fingerprint[100];
4068 char *keystr = snewn(len, char);
4069 rsastr_fmt(keystr, &s->hostkey);
4070 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4072 /* First check against manually configured host keys. */
4073 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4074 if (s->dlgret == 0) { /* did not match */
4075 bombout(("Host key did not appear in manually configured list"));
4078 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4079 ssh_set_frozen(ssh, 1);
4080 s->dlgret = verify_ssh_host_key(ssh->frontend,
4081 ssh->savedhost, ssh->savedport,
4082 "rsa", keystr, fingerprint,
4083 ssh_dialog_callback, ssh);
4088 if (s->dlgret < 0) {
4092 bombout(("Unexpected data from server while waiting"
4093 " for user host key response"));
4096 } while (pktin || inlen > 0);
4097 s->dlgret = ssh->user_response;
4099 ssh_set_frozen(ssh, 0);
4101 if (s->dlgret == 0) {
4102 ssh_disconnect(ssh, "User aborted at host key verification",
4111 for (i = 0; i < 32; i++) {
4112 s->rsabuf[i] = ssh->session_key[i];
4114 s->rsabuf[i] ^= s->session_id[i];
4117 if (s->hostkey.bytes > s->servkey.bytes) {
4118 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4120 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4122 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4124 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4127 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4131 logevent("Encrypted session key");
4134 int cipher_chosen = 0, warn = 0;
4135 const char *cipher_string = NULL;
4137 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4138 int next_cipher = conf_get_int_int(ssh->conf,
4139 CONF_ssh_cipherlist, i);
4140 if (next_cipher == CIPHER_WARN) {
4141 /* If/when we choose a cipher, warn about it */
4143 } else if (next_cipher == CIPHER_AES) {
4144 /* XXX Probably don't need to mention this. */
4145 logevent("AES not supported in SSH-1, skipping");
4147 switch (next_cipher) {
4148 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4149 cipher_string = "3DES"; break;
4150 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4151 cipher_string = "Blowfish"; break;
4152 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4153 cipher_string = "single-DES"; break;
4155 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4159 if (!cipher_chosen) {
4160 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4161 bombout(("Server violates SSH-1 protocol by not "
4162 "supporting 3DES encryption"));
4164 /* shouldn't happen */
4165 bombout(("No supported ciphers found"));
4169 /* Warn about chosen cipher if necessary. */
4171 ssh_set_frozen(ssh, 1);
4172 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4173 ssh_dialog_callback, ssh);
4174 if (s->dlgret < 0) {
4178 bombout(("Unexpected data from server while waiting"
4179 " for user response"));
4182 } while (pktin || inlen > 0);
4183 s->dlgret = ssh->user_response;
4185 ssh_set_frozen(ssh, 0);
4186 if (s->dlgret == 0) {
4187 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4194 switch (s->cipher_type) {
4195 case SSH_CIPHER_3DES:
4196 logevent("Using 3DES encryption");
4198 case SSH_CIPHER_DES:
4199 logevent("Using single-DES encryption");
4201 case SSH_CIPHER_BLOWFISH:
4202 logevent("Using Blowfish encryption");
4206 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4207 PKT_CHAR, s->cipher_type,
4208 PKT_DATA, cookie, 8,
4209 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4210 PKT_DATA, s->rsabuf, s->len,
4211 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4213 logevent("Trying to enable encryption...");
4217 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4218 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4220 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4221 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4222 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4224 ssh->crcda_ctx = crcda_make_context();
4225 logevent("Installing CRC compensation attack detector");
4227 if (s->servkey.modulus) {
4228 sfree(s->servkey.modulus);
4229 s->servkey.modulus = NULL;
4231 if (s->servkey.exponent) {
4232 sfree(s->servkey.exponent);
4233 s->servkey.exponent = NULL;
4235 if (s->hostkey.modulus) {
4236 sfree(s->hostkey.modulus);
4237 s->hostkey.modulus = NULL;
4239 if (s->hostkey.exponent) {
4240 sfree(s->hostkey.exponent);
4241 s->hostkey.exponent = NULL;
4245 if (pktin->type != SSH1_SMSG_SUCCESS) {
4246 bombout(("Encryption not successfully enabled"));
4250 logevent("Successfully started encryption");
4252 fflush(stdout); /* FIXME eh? */
4254 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4255 int ret; /* need not be kept over crReturn */
4256 s->cur_prompt = new_prompts(ssh->frontend);
4257 s->cur_prompt->to_server = TRUE;
4258 s->cur_prompt->name = dupstr("SSH login name");
4259 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4260 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4263 crWaitUntil(!pktin);
4264 ret = get_userpass_input(s->cur_prompt, in, inlen);
4269 * Failed to get a username. Terminate.
4271 free_prompts(s->cur_prompt);
4272 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4275 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4276 free_prompts(s->cur_prompt);
4279 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4281 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4283 if (flags & FLAG_INTERACTIVE &&
4284 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4285 c_write_str(ssh, userlog);
4286 c_write_str(ssh, "\r\n");
4294 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4295 /* We must not attempt PK auth. Pretend we've already tried it. */
4296 s->tried_publickey = s->tried_agent = 1;
4298 s->tried_publickey = s->tried_agent = 0;
4300 s->tis_auth_refused = s->ccard_auth_refused = 0;
4302 * Load the public half of any configured keyfile for later use.
4304 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4305 if (!filename_is_null(s->keyfile)) {
4307 logeventf(ssh, "Reading key file \"%.150s\"",
4308 filename_to_str(s->keyfile));
4309 keytype = key_type(s->keyfile);
4310 if (keytype == SSH_KEYTYPE_SSH1 ||
4311 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4313 if (rsakey_pubblob(s->keyfile,
4314 &s->publickey_blob, &s->publickey_bloblen,
4315 &s->publickey_comment, &error)) {
4316 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4317 if (!s->privatekey_available)
4318 logeventf(ssh, "Key file contains public key only");
4319 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4323 logeventf(ssh, "Unable to load key (%s)", error);
4324 msgbuf = dupprintf("Unable to load key file "
4325 "\"%.150s\" (%s)\r\n",
4326 filename_to_str(s->keyfile),
4328 c_write_str(ssh, msgbuf);
4330 s->publickey_blob = NULL;
4334 logeventf(ssh, "Unable to use this key file (%s)",
4335 key_type_to_str(keytype));
4336 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4338 filename_to_str(s->keyfile),
4339 key_type_to_str(keytype));
4340 c_write_str(ssh, msgbuf);
4342 s->publickey_blob = NULL;
4345 s->publickey_blob = NULL;
4347 while (pktin->type == SSH1_SMSG_FAILURE) {
4348 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4350 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4352 * Attempt RSA authentication using Pageant.
4358 logevent("Pageant is running. Requesting keys.");
4360 /* Request the keys held by the agent. */
4361 PUT_32BIT(s->request, 1);
4362 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4363 if (!agent_query(s->request, 5, &r, &s->responselen,
4364 ssh_agent_callback, ssh)) {
4368 bombout(("Unexpected data from server while waiting"
4369 " for agent response"));
4372 } while (pktin || inlen > 0);
4373 r = ssh->agent_response;
4374 s->responselen = ssh->agent_response_len;
4376 s->response = (unsigned char *) r;
4377 if (s->response && s->responselen >= 5 &&
4378 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4379 s->p = s->response + 5;
4380 s->nkeys = toint(GET_32BIT(s->p));
4382 logeventf(ssh, "Pageant reported negative key count %d",
4387 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4388 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4389 unsigned char *pkblob = s->p;
4393 do { /* do while (0) to make breaking easy */
4394 n = ssh1_read_bignum
4395 (s->p, toint(s->responselen-(s->p-s->response)),
4400 n = ssh1_read_bignum
4401 (s->p, toint(s->responselen-(s->p-s->response)),
4406 if (s->responselen - (s->p-s->response) < 4)
4408 s->commentlen = toint(GET_32BIT(s->p));
4410 if (s->commentlen < 0 ||
4411 toint(s->responselen - (s->p-s->response)) <
4414 s->commentp = (char *)s->p;
4415 s->p += s->commentlen;
4419 logevent("Pageant key list packet was truncated");
4423 if (s->publickey_blob) {
4424 if (!memcmp(pkblob, s->publickey_blob,
4425 s->publickey_bloblen)) {
4426 logeventf(ssh, "Pageant key #%d matches "
4427 "configured key file", s->keyi);
4428 s->tried_publickey = 1;
4430 /* Skip non-configured key */
4433 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4434 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4435 PKT_BIGNUM, s->key.modulus, PKT_END);
4437 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4438 logevent("Key refused");
4441 logevent("Received RSA challenge");
4442 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4443 bombout(("Server's RSA challenge was badly formatted"));
4448 char *agentreq, *q, *ret;
4451 len = 1 + 4; /* message type, bit count */
4452 len += ssh1_bignum_length(s->key.exponent);
4453 len += ssh1_bignum_length(s->key.modulus);
4454 len += ssh1_bignum_length(s->challenge);
4455 len += 16; /* session id */
4456 len += 4; /* response format */
4457 agentreq = snewn(4 + len, char);
4458 PUT_32BIT(agentreq, len);
4460 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4461 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4463 q += ssh1_write_bignum(q, s->key.exponent);
4464 q += ssh1_write_bignum(q, s->key.modulus);
4465 q += ssh1_write_bignum(q, s->challenge);
4466 memcpy(q, s->session_id, 16);
4468 PUT_32BIT(q, 1); /* response format */
4469 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4470 ssh_agent_callback, ssh)) {
4475 bombout(("Unexpected data from server"
4476 " while waiting for agent"
4480 } while (pktin || inlen > 0);
4481 vret = ssh->agent_response;
4482 retlen = ssh->agent_response_len;
4487 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4488 logevent("Sending Pageant's response");
4489 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4490 PKT_DATA, ret + 5, 16,
4494 if (pktin->type == SSH1_SMSG_SUCCESS) {
4496 ("Pageant's response accepted");
4497 if (flags & FLAG_VERBOSE) {
4498 c_write_str(ssh, "Authenticated using"
4500 c_write(ssh, s->commentp,
4502 c_write_str(ssh, "\" from agent\r\n");
4507 ("Pageant's response not accepted");
4510 ("Pageant failed to answer challenge");
4514 logevent("No reply received from Pageant");
4517 freebn(s->key.exponent);
4518 freebn(s->key.modulus);
4519 freebn(s->challenge);
4524 if (s->publickey_blob && !s->tried_publickey)
4525 logevent("Configured key file not in Pageant");
4527 logevent("Failed to get reply from Pageant");
4532 if (s->publickey_blob && s->privatekey_available &&
4533 !s->tried_publickey) {
4535 * Try public key authentication with the specified
4538 int got_passphrase; /* need not be kept over crReturn */
4539 if (flags & FLAG_VERBOSE)
4540 c_write_str(ssh, "Trying public key authentication.\r\n");
4541 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4542 logeventf(ssh, "Trying public key \"%s\"",
4543 filename_to_str(s->keyfile));
4544 s->tried_publickey = 1;
4545 got_passphrase = FALSE;
4546 while (!got_passphrase) {
4548 * Get a passphrase, if necessary.
4550 char *passphrase = NULL; /* only written after crReturn */
4552 if (!s->privatekey_encrypted) {
4553 if (flags & FLAG_VERBOSE)
4554 c_write_str(ssh, "No passphrase required.\r\n");
4557 int ret; /* need not be kept over crReturn */
4558 s->cur_prompt = new_prompts(ssh->frontend);
4559 s->cur_prompt->to_server = FALSE;
4560 s->cur_prompt->name = dupstr("SSH key passphrase");
4561 add_prompt(s->cur_prompt,
4562 dupprintf("Passphrase for key \"%.100s\": ",
4563 s->publickey_comment), FALSE);
4564 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4567 crWaitUntil(!pktin);
4568 ret = get_userpass_input(s->cur_prompt, in, inlen);
4572 /* Failed to get a passphrase. Terminate. */
4573 free_prompts(s->cur_prompt);
4574 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4578 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4579 free_prompts(s->cur_prompt);
4582 * Try decrypting key with passphrase.
4584 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4585 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4588 smemclr(passphrase, strlen(passphrase));
4592 /* Correct passphrase. */
4593 got_passphrase = TRUE;
4594 } else if (ret == 0) {
4595 c_write_str(ssh, "Couldn't load private key from ");
4596 c_write_str(ssh, filename_to_str(s->keyfile));
4597 c_write_str(ssh, " (");
4598 c_write_str(ssh, error);
4599 c_write_str(ssh, ").\r\n");
4600 got_passphrase = FALSE;
4601 break; /* go and try something else */
4602 } else if (ret == -1) {
4603 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4604 got_passphrase = FALSE;
4607 assert(0 && "unexpected return from loadrsakey()");
4608 got_passphrase = FALSE; /* placate optimisers */
4612 if (got_passphrase) {
4615 * Send a public key attempt.
4617 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4618 PKT_BIGNUM, s->key.modulus, PKT_END);
4621 if (pktin->type == SSH1_SMSG_FAILURE) {
4622 c_write_str(ssh, "Server refused our public key.\r\n");
4623 continue; /* go and try something else */
4625 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4626 bombout(("Bizarre response to offer of public key"));
4632 unsigned char buffer[32];
4633 Bignum challenge, response;
4635 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4636 bombout(("Server's RSA challenge was badly formatted"));
4639 response = rsadecrypt(challenge, &s->key);
4640 freebn(s->key.private_exponent);/* burn the evidence */
4642 for (i = 0; i < 32; i++) {
4643 buffer[i] = bignum_byte(response, 31 - i);
4647 MD5Update(&md5c, buffer, 32);
4648 MD5Update(&md5c, s->session_id, 16);
4649 MD5Final(buffer, &md5c);
4651 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4652 PKT_DATA, buffer, 16, PKT_END);
4659 if (pktin->type == SSH1_SMSG_FAILURE) {
4660 if (flags & FLAG_VERBOSE)
4661 c_write_str(ssh, "Failed to authenticate with"
4662 " our public key.\r\n");
4663 continue; /* go and try something else */
4664 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4665 bombout(("Bizarre response to RSA authentication response"));
4669 break; /* we're through! */
4675 * Otherwise, try various forms of password-like authentication.
4677 s->cur_prompt = new_prompts(ssh->frontend);
4679 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4680 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4681 !s->tis_auth_refused) {
4682 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4683 logevent("Requested TIS authentication");
4684 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4686 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4687 logevent("TIS authentication declined");
4688 if (flags & FLAG_INTERACTIVE)
4689 c_write_str(ssh, "TIS authentication refused.\r\n");
4690 s->tis_auth_refused = 1;
4695 char *instr_suf, *prompt;
4697 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4699 bombout(("TIS challenge packet was badly formed"));
4702 logevent("Received TIS challenge");
4703 s->cur_prompt->to_server = TRUE;
4704 s->cur_prompt->name = dupstr("SSH TIS authentication");
4705 /* Prompt heuristic comes from OpenSSH */
4706 if (memchr(challenge, '\n', challengelen)) {
4707 instr_suf = dupstr("");
4708 prompt = dupprintf("%.*s", challengelen, challenge);
4710 instr_suf = dupprintf("%.*s", challengelen, challenge);
4711 prompt = dupstr("Response: ");
4713 s->cur_prompt->instruction =
4714 dupprintf("Using TIS authentication.%s%s",
4715 (*instr_suf) ? "\n" : "",
4717 s->cur_prompt->instr_reqd = TRUE;
4718 add_prompt(s->cur_prompt, prompt, FALSE);
4722 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4723 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4724 !s->ccard_auth_refused) {
4725 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4726 logevent("Requested CryptoCard authentication");
4727 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4729 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4730 logevent("CryptoCard authentication declined");
4731 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4732 s->ccard_auth_refused = 1;
4737 char *instr_suf, *prompt;
4739 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4741 bombout(("CryptoCard challenge packet was badly formed"));
4744 logevent("Received CryptoCard challenge");
4745 s->cur_prompt->to_server = TRUE;
4746 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4747 s->cur_prompt->name_reqd = FALSE;
4748 /* Prompt heuristic comes from OpenSSH */
4749 if (memchr(challenge, '\n', challengelen)) {
4750 instr_suf = dupstr("");
4751 prompt = dupprintf("%.*s", challengelen, challenge);
4753 instr_suf = dupprintf("%.*s", challengelen, challenge);
4754 prompt = dupstr("Response: ");
4756 s->cur_prompt->instruction =
4757 dupprintf("Using CryptoCard authentication.%s%s",
4758 (*instr_suf) ? "\n" : "",
4760 s->cur_prompt->instr_reqd = TRUE;
4761 add_prompt(s->cur_prompt, prompt, FALSE);
4765 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4766 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4767 bombout(("No supported authentication methods available"));
4770 s->cur_prompt->to_server = TRUE;
4771 s->cur_prompt->name = dupstr("SSH password");
4772 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4773 ssh->username, ssh->savedhost),
4778 * Show password prompt, having first obtained it via a TIS
4779 * or CryptoCard exchange if we're doing TIS or CryptoCard
4783 int ret; /* need not be kept over crReturn */
4784 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4787 crWaitUntil(!pktin);
4788 ret = get_userpass_input(s->cur_prompt, in, inlen);
4793 * Failed to get a password (for example
4794 * because one was supplied on the command line
4795 * which has already failed to work). Terminate.
4797 free_prompts(s->cur_prompt);
4798 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4803 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4805 * Defence against traffic analysis: we send a
4806 * whole bunch of packets containing strings of
4807 * different lengths. One of these strings is the
4808 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4809 * The others are all random data in
4810 * SSH1_MSG_IGNORE packets. This way a passive
4811 * listener can't tell which is the password, and
4812 * hence can't deduce the password length.
4814 * Anybody with a password length greater than 16
4815 * bytes is going to have enough entropy in their
4816 * password that a listener won't find it _that_
4817 * much help to know how long it is. So what we'll
4820 * - if password length < 16, we send 15 packets
4821 * containing string lengths 1 through 15
4823 * - otherwise, we let N be the nearest multiple
4824 * of 8 below the password length, and send 8
4825 * packets containing string lengths N through
4826 * N+7. This won't obscure the order of
4827 * magnitude of the password length, but it will
4828 * introduce a bit of extra uncertainty.
4830 * A few servers can't deal with SSH1_MSG_IGNORE, at
4831 * least in this context. For these servers, we need
4832 * an alternative defence. We make use of the fact
4833 * that the password is interpreted as a C string:
4834 * so we can append a NUL, then some random data.
4836 * A few servers can deal with neither SSH1_MSG_IGNORE
4837 * here _nor_ a padded password string.
4838 * For these servers we are left with no defences
4839 * against password length sniffing.
4841 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4842 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4844 * The server can deal with SSH1_MSG_IGNORE, so
4845 * we can use the primary defence.
4847 int bottom, top, pwlen, i;
4850 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4852 bottom = 0; /* zero length passwords are OK! :-) */
4855 bottom = pwlen & ~7;
4859 assert(pwlen >= bottom && pwlen <= top);
4861 randomstr = snewn(top + 1, char);
4863 for (i = bottom; i <= top; i++) {
4865 defer_packet(ssh, s->pwpkt_type,
4866 PKT_STR,s->cur_prompt->prompts[0]->result,
4869 for (j = 0; j < i; j++) {
4871 randomstr[j] = random_byte();
4872 } while (randomstr[j] == '\0');
4874 randomstr[i] = '\0';
4875 defer_packet(ssh, SSH1_MSG_IGNORE,
4876 PKT_STR, randomstr, PKT_END);
4879 logevent("Sending password with camouflage packets");
4880 ssh_pkt_defersend(ssh);
4883 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4885 * The server can't deal with SSH1_MSG_IGNORE
4886 * but can deal with padded passwords, so we
4887 * can use the secondary defence.
4893 len = strlen(s->cur_prompt->prompts[0]->result);
4894 if (len < sizeof(string)) {
4896 strcpy(string, s->cur_prompt->prompts[0]->result);
4897 len++; /* cover the zero byte */
4898 while (len < sizeof(string)) {
4899 string[len++] = (char) random_byte();
4902 ss = s->cur_prompt->prompts[0]->result;
4904 logevent("Sending length-padded password");
4905 send_packet(ssh, s->pwpkt_type,
4906 PKT_INT, len, PKT_DATA, ss, len,
4910 * The server is believed unable to cope with
4911 * any of our password camouflage methods.
4914 len = strlen(s->cur_prompt->prompts[0]->result);
4915 logevent("Sending unpadded password");
4916 send_packet(ssh, s->pwpkt_type,
4918 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4922 send_packet(ssh, s->pwpkt_type,
4923 PKT_STR, s->cur_prompt->prompts[0]->result,
4926 logevent("Sent password");
4927 free_prompts(s->cur_prompt);
4929 if (pktin->type == SSH1_SMSG_FAILURE) {
4930 if (flags & FLAG_VERBOSE)
4931 c_write_str(ssh, "Access denied\r\n");
4932 logevent("Authentication refused");
4933 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4934 bombout(("Strange packet received, type %d", pktin->type));
4940 if (s->publickey_blob) {
4941 sfree(s->publickey_blob);
4942 sfree(s->publickey_comment);
4945 logevent("Authentication successful");
4950 static void ssh_channel_try_eof(struct ssh_channel *c)
4953 assert(c->pending_eof); /* precondition for calling us */
4955 return; /* can't close: not even opened yet */
4956 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4957 return; /* can't send EOF: pending outgoing data */
4959 c->pending_eof = FALSE; /* we're about to send it */
4960 if (ssh->version == 1) {
4961 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4963 c->closes |= CLOSES_SENT_EOF;
4965 struct Packet *pktout;
4966 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4967 ssh2_pkt_adduint32(pktout, c->remoteid);
4968 ssh2_pkt_send(ssh, pktout);
4969 c->closes |= CLOSES_SENT_EOF;
4970 ssh2_channel_check_close(c);
4974 Conf *sshfwd_get_conf(struct ssh_channel *c)
4980 void sshfwd_write_eof(struct ssh_channel *c)
4984 if (ssh->state == SSH_STATE_CLOSED)
4987 if (c->closes & CLOSES_SENT_EOF)
4990 c->pending_eof = TRUE;
4991 ssh_channel_try_eof(c);
4994 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4998 if (ssh->state == SSH_STATE_CLOSED)
5003 x11_close(c->u.x11.xconn);
5004 logeventf(ssh, "Forwarded X11 connection terminated due to local "
5008 case CHAN_SOCKDATA_DORMANT:
5009 pfd_close(c->u.pfd.pf);
5010 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
5013 c->type = CHAN_ZOMBIE;
5014 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5016 ssh2_channel_check_close(c);
5019 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5023 if (ssh->state == SSH_STATE_CLOSED)
5026 return ssh_send_channel_data(c, buf, len);
5029 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5033 if (ssh->state == SSH_STATE_CLOSED)
5036 ssh_channel_unthrottle(c, bufsize);
5039 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5041 struct queued_handler *qh = ssh->qhead;
5045 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5048 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5049 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5052 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5053 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5057 ssh->qhead = qh->next;
5059 if (ssh->qhead->msg1 > 0) {
5060 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5061 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5063 if (ssh->qhead->msg2 > 0) {
5064 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5065 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5068 ssh->qhead = ssh->qtail = NULL;
5071 qh->handler(ssh, pktin, qh->ctx);
5076 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5077 chandler_fn_t handler, void *ctx)
5079 struct queued_handler *qh;
5081 qh = snew(struct queued_handler);
5084 qh->handler = handler;
5088 if (ssh->qtail == NULL) {
5092 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5093 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5096 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5097 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5100 ssh->qtail->next = qh;
5105 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5107 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5109 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5110 SSH2_MSG_REQUEST_SUCCESS)) {
5111 logeventf(ssh, "Remote port forwarding from %s enabled",
5114 logeventf(ssh, "Remote port forwarding from %s refused",
5117 rpf = del234(ssh->rportfwds, pf);
5119 pf->pfrec->remote = NULL;
5124 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5127 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5130 pf->share_ctx = share_ctx;
5131 pf->shost = dupstr(shost);
5133 pf->sportdesc = NULL;
5134 if (!ssh->rportfwds) {
5135 assert(ssh->version == 2);
5136 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5138 if (add234(ssh->rportfwds, pf) != pf) {
5146 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5149 share_got_pkt_from_server(ctx, pktin->type,
5150 pktin->body, pktin->length);
5153 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5155 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5156 ssh_sharing_global_request_response, share_ctx);
5159 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5161 struct ssh_portfwd *epf;
5165 if (!ssh->portfwds) {
5166 ssh->portfwds = newtree234(ssh_portcmp);
5169 * Go through the existing port forwardings and tag them
5170 * with status==DESTROY. Any that we want to keep will be
5171 * re-enabled (status==KEEP) as we go through the
5172 * configuration and find out which bits are the same as
5175 struct ssh_portfwd *epf;
5177 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5178 epf->status = DESTROY;
5181 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5183 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5184 char *kp, *kp2, *vp, *vp2;
5185 char address_family, type;
5186 int sport,dport,sserv,dserv;
5187 char *sports, *dports, *saddr, *host;
5191 address_family = 'A';
5193 if (*kp == 'A' || *kp == '4' || *kp == '6')
5194 address_family = *kp++;
5195 if (*kp == 'L' || *kp == 'R')
5198 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5200 * There's a colon in the middle of the source port
5201 * string, which means that the part before it is
5202 * actually a source address.
5204 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5205 saddr = host_strduptrim(saddr_tmp);
5212 sport = atoi(sports);
5216 sport = net_service_lookup(sports);
5218 logeventf(ssh, "Service lookup failed for source"
5219 " port \"%s\"", sports);
5223 if (type == 'L' && !strcmp(val, "D")) {
5224 /* dynamic forwarding */
5231 /* ordinary forwarding */
5233 vp2 = vp + host_strcspn(vp, ":");
5234 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5238 dport = atoi(dports);
5242 dport = net_service_lookup(dports);
5244 logeventf(ssh, "Service lookup failed for destination"
5245 " port \"%s\"", dports);
5250 if (sport && dport) {
5251 /* Set up a description of the source port. */
5252 struct ssh_portfwd *pfrec, *epfrec;
5254 pfrec = snew(struct ssh_portfwd);
5256 pfrec->saddr = saddr;
5257 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5258 pfrec->sport = sport;
5259 pfrec->daddr = host;
5260 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5261 pfrec->dport = dport;
5262 pfrec->local = NULL;
5263 pfrec->remote = NULL;
5264 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5265 address_family == '6' ? ADDRTYPE_IPV6 :
5268 epfrec = add234(ssh->portfwds, pfrec);
5269 if (epfrec != pfrec) {
5270 if (epfrec->status == DESTROY) {
5272 * We already have a port forwarding up and running
5273 * with precisely these parameters. Hence, no need
5274 * to do anything; simply re-tag the existing one
5277 epfrec->status = KEEP;
5280 * Anything else indicates that there was a duplicate
5281 * in our input, which we'll silently ignore.
5283 free_portfwd(pfrec);
5285 pfrec->status = CREATE;
5294 * Now go through and destroy any port forwardings which were
5297 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5298 if (epf->status == DESTROY) {
5301 message = dupprintf("%s port forwarding from %s%s%d",
5302 epf->type == 'L' ? "local" :
5303 epf->type == 'R' ? "remote" : "dynamic",
5304 epf->saddr ? epf->saddr : "",
5305 epf->saddr ? ":" : "",
5308 if (epf->type != 'D') {
5309 char *msg2 = dupprintf("%s to %s:%d", message,
5310 epf->daddr, epf->dport);
5315 logeventf(ssh, "Cancelling %s", message);
5318 /* epf->remote or epf->local may be NULL if setting up a
5319 * forwarding failed. */
5321 struct ssh_rportfwd *rpf = epf->remote;
5322 struct Packet *pktout;
5325 * Cancel the port forwarding at the server
5328 if (ssh->version == 1) {
5330 * We cannot cancel listening ports on the
5331 * server side in SSH-1! There's no message
5332 * to support it. Instead, we simply remove
5333 * the rportfwd record from the local end
5334 * so that any connections the server tries
5335 * to make on it are rejected.
5338 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5339 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5340 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5342 ssh2_pkt_addstring(pktout, epf->saddr);
5343 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5344 /* XXX: rport_acceptall may not represent
5345 * what was used to open the original connection,
5346 * since it's reconfigurable. */
5347 ssh2_pkt_addstring(pktout, "");
5349 ssh2_pkt_addstring(pktout, "localhost");
5351 ssh2_pkt_adduint32(pktout, epf->sport);
5352 ssh2_pkt_send(ssh, pktout);
5355 del234(ssh->rportfwds, rpf);
5357 } else if (epf->local) {
5358 pfl_terminate(epf->local);
5361 delpos234(ssh->portfwds, i);
5363 i--; /* so we don't skip one in the list */
5367 * And finally, set up any new port forwardings (status==CREATE).
5369 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5370 if (epf->status == CREATE) {
5371 char *sportdesc, *dportdesc;
5372 sportdesc = dupprintf("%s%s%s%s%d%s",
5373 epf->saddr ? epf->saddr : "",
5374 epf->saddr ? ":" : "",
5375 epf->sserv ? epf->sserv : "",
5376 epf->sserv ? "(" : "",
5378 epf->sserv ? ")" : "");
5379 if (epf->type == 'D') {
5382 dportdesc = dupprintf("%s:%s%s%d%s",
5384 epf->dserv ? epf->dserv : "",
5385 epf->dserv ? "(" : "",
5387 epf->dserv ? ")" : "");
5390 if (epf->type == 'L') {
5391 char *err = pfl_listen(epf->daddr, epf->dport,
5392 epf->saddr, epf->sport,
5393 ssh, conf, &epf->local,
5394 epf->addressfamily);
5396 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5397 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5398 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5399 sportdesc, dportdesc,
5400 err ? " failed: " : "", err ? err : "");
5403 } else if (epf->type == 'D') {
5404 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5405 ssh, conf, &epf->local,
5406 epf->addressfamily);
5408 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5409 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5410 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5412 err ? " failed: " : "", err ? err : "");
5417 struct ssh_rportfwd *pf;
5420 * Ensure the remote port forwardings tree exists.
5422 if (!ssh->rportfwds) {
5423 if (ssh->version == 1)
5424 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5426 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5429 pf = snew(struct ssh_rportfwd);
5430 pf->share_ctx = NULL;
5431 pf->dhost = dupstr(epf->daddr);
5432 pf->dport = epf->dport;
5434 pf->shost = dupstr(epf->saddr);
5435 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5436 pf->shost = dupstr("");
5438 pf->shost = dupstr("localhost");
5440 pf->sport = epf->sport;
5441 if (add234(ssh->rportfwds, pf) != pf) {
5442 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5443 epf->daddr, epf->dport);
5446 logeventf(ssh, "Requesting remote port %s"
5447 " forward to %s", sportdesc, dportdesc);
5449 pf->sportdesc = sportdesc;
5454 if (ssh->version == 1) {
5455 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5456 PKT_INT, epf->sport,
5457 PKT_STR, epf->daddr,
5458 PKT_INT, epf->dport,
5460 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5462 ssh_rportfwd_succfail, pf);
5464 struct Packet *pktout;
5465 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5466 ssh2_pkt_addstring(pktout, "tcpip-forward");
5467 ssh2_pkt_addbool(pktout, 1);/* want reply */
5468 ssh2_pkt_addstring(pktout, pf->shost);
5469 ssh2_pkt_adduint32(pktout, pf->sport);
5470 ssh2_pkt_send(ssh, pktout);
5472 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5473 SSH2_MSG_REQUEST_FAILURE,
5474 ssh_rportfwd_succfail, pf);
5483 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5486 int stringlen, bufsize;
5488 ssh_pkt_getstring(pktin, &string, &stringlen);
5489 if (string == NULL) {
5490 bombout(("Incoming terminal data packet was badly formed"));
5494 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5496 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5497 ssh->v1_stdout_throttling = 1;
5498 ssh_throttle_conn(ssh, +1);
5502 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5504 /* Remote side is trying to open a channel to talk to our
5505 * X-Server. Give them back a local channel number. */
5506 struct ssh_channel *c;
5507 int remoteid = ssh_pkt_getuint32(pktin);
5509 logevent("Received X11 connect request");
5510 /* Refuse if X11 forwarding is disabled. */
5511 if (!ssh->X11_fwd_enabled) {
5512 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5513 PKT_INT, remoteid, PKT_END);
5514 logevent("Rejected X11 connect request");
5516 c = snew(struct ssh_channel);
5519 ssh_channel_init(c);
5520 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5521 c->remoteid = remoteid;
5522 c->halfopen = FALSE;
5523 c->type = CHAN_X11; /* identify channel type */
5524 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5525 PKT_INT, c->remoteid, PKT_INT,
5526 c->localid, PKT_END);
5527 logevent("Opened X11 forward channel");
5531 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5533 /* Remote side is trying to open a channel to talk to our
5534 * agent. Give them back a local channel number. */
5535 struct ssh_channel *c;
5536 int remoteid = ssh_pkt_getuint32(pktin);
5538 /* Refuse if agent forwarding is disabled. */
5539 if (!ssh->agentfwd_enabled) {
5540 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5541 PKT_INT, remoteid, PKT_END);
5543 c = snew(struct ssh_channel);
5545 ssh_channel_init(c);
5546 c->remoteid = remoteid;
5547 c->halfopen = FALSE;
5548 c->type = CHAN_AGENT; /* identify channel type */
5549 c->u.a.lensofar = 0;
5550 c->u.a.message = NULL;
5551 c->u.a.outstanding_requests = 0;
5552 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5553 PKT_INT, c->remoteid, PKT_INT, c->localid,
5558 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5560 /* Remote side is trying to open a channel to talk to a
5561 * forwarded port. Give them back a local channel number. */
5562 struct ssh_rportfwd pf, *pfp;
5568 remoteid = ssh_pkt_getuint32(pktin);
5569 ssh_pkt_getstring(pktin, &host, &hostsize);
5570 port = ssh_pkt_getuint32(pktin);
5572 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5574 pfp = find234(ssh->rportfwds, &pf, NULL);
5577 logeventf(ssh, "Rejected remote port open request for %s:%d",
5579 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5580 PKT_INT, remoteid, PKT_END);
5582 struct ssh_channel *c = snew(struct ssh_channel);
5585 logeventf(ssh, "Received remote port open request for %s:%d",
5587 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5588 c, ssh->conf, pfp->pfrec->addressfamily);
5590 logeventf(ssh, "Port open failed: %s", err);
5593 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5594 PKT_INT, remoteid, PKT_END);
5596 ssh_channel_init(c);
5597 c->remoteid = remoteid;
5598 c->halfopen = FALSE;
5599 c->type = CHAN_SOCKDATA; /* identify channel type */
5600 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5601 PKT_INT, c->remoteid, PKT_INT,
5602 c->localid, PKT_END);
5603 logevent("Forwarded port opened successfully");
5610 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5612 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5613 unsigned int localid = ssh_pkt_getuint32(pktin);
5614 struct ssh_channel *c;
5616 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5617 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5618 c->remoteid = localid;
5619 c->halfopen = FALSE;
5620 c->type = CHAN_SOCKDATA;
5621 c->throttling_conn = 0;
5622 pfd_confirm(c->u.pfd.pf);
5625 if (c && c->pending_eof) {
5627 * We have a pending close on this channel,
5628 * which we decided on before the server acked
5629 * the channel open. So now we know the
5630 * remoteid, we can close it again.
5632 ssh_channel_try_eof(c);
5636 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5638 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5639 struct ssh_channel *c;
5641 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5642 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5643 logevent("Forwarded connection refused by server");
5644 pfd_close(c->u.pfd.pf);
5645 del234(ssh->channels, c);
5650 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5652 /* Remote side closes a channel. */
5653 unsigned i = ssh_pkt_getuint32(pktin);
5654 struct ssh_channel *c;
5655 c = find234(ssh->channels, &i, ssh_channelfind);
5656 if (c && !c->halfopen) {
5658 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5659 !(c->closes & CLOSES_RCVD_EOF)) {
5661 * Received CHANNEL_CLOSE, which we translate into
5664 int send_close = FALSE;
5666 c->closes |= CLOSES_RCVD_EOF;
5671 x11_send_eof(c->u.x11.xconn);
5677 pfd_send_eof(c->u.pfd.pf);
5686 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5687 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5689 c->closes |= CLOSES_SENT_EOF;
5693 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5694 !(c->closes & CLOSES_RCVD_CLOSE)) {
5696 if (!(c->closes & CLOSES_SENT_EOF)) {
5697 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5698 " for which we never sent CHANNEL_CLOSE\n", i));
5701 c->closes |= CLOSES_RCVD_CLOSE;
5704 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5705 !(c->closes & CLOSES_SENT_CLOSE)) {
5706 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5707 PKT_INT, c->remoteid, PKT_END);
5708 c->closes |= CLOSES_SENT_CLOSE;
5711 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5712 ssh_channel_destroy(c);
5714 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5715 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5716 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5722 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5724 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5727 while (length > 0) {
5728 if (c->u.a.lensofar < 4) {
5729 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)length);
5730 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
5733 c->u.a.lensofar += l;
5735 if (c->u.a.lensofar == 4) {
5736 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
5737 c->u.a.message = snewn(c->u.a.totallen, unsigned char);
5738 memcpy(c->u.a.message, c->u.a.msglen, 4);
5740 if (c->u.a.lensofar >= 4 && length > 0) {
5741 unsigned int l = min(c->u.a.totallen - c->u.a.lensofar,
5743 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
5746 c->u.a.lensofar += l;
5748 if (c->u.a.lensofar == c->u.a.totallen) {
5751 c->u.a.outstanding_requests++;
5752 if (agent_query(c->u.a.message, c->u.a.totallen, &reply, &replylen,
5753 ssh_agentf_callback, c))
5754 ssh_agentf_callback(c, reply, replylen);
5755 sfree(c->u.a.message);
5756 c->u.a.message = NULL;
5757 c->u.a.lensofar = 0;
5760 return 0; /* agent channels never back up */
5763 static int ssh_channel_data(struct ssh_channel *c, int is_stderr,
5764 char *data, int length)
5767 case CHAN_MAINSESSION:
5768 return from_backend(c->ssh->frontend, is_stderr, data, length);
5770 return x11_send(c->u.x11.xconn, data, length);
5772 return pfd_send(c->u.pfd.pf, data, length);
5774 return ssh_agent_channel_data(c, data, length);
5779 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5781 /* Data sent down one of our channels. */
5782 int i = ssh_pkt_getuint32(pktin);
5785 struct ssh_channel *c;
5787 ssh_pkt_getstring(pktin, &p, &len);
5789 c = find234(ssh->channels, &i, ssh_channelfind);
5791 int bufsize = ssh_channel_data(c, FALSE, p, len);
5792 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5793 c->throttling_conn = 1;
5794 ssh_throttle_conn(ssh, +1);
5799 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5801 ssh->exitcode = ssh_pkt_getuint32(pktin);
5802 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5803 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5805 * In case `helpful' firewalls or proxies tack
5806 * extra human-readable text on the end of the
5807 * session which we might mistake for another
5808 * encrypted packet, we close the session once
5809 * we've sent EXIT_CONFIRMATION.
5811 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5814 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5815 static void ssh1_send_ttymode(void *data,
5816 const struct ssh_ttymode *mode, char *val)
5818 struct Packet *pktout = (struct Packet *)data;
5819 unsigned int arg = 0;
5821 switch (mode->type) {
5823 arg = ssh_tty_parse_specchar(val);
5826 arg = ssh_tty_parse_boolean(val);
5829 ssh2_pkt_addbyte(pktout, mode->opcode);
5830 ssh2_pkt_addbyte(pktout, arg);
5833 int ssh_agent_forwarding_permitted(Ssh ssh)
5835 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5838 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5839 struct Packet *pktin)
5841 crBegin(ssh->do_ssh1_connection_crstate);
5843 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5844 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5845 ssh1_smsg_stdout_stderr_data;
5847 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5848 ssh1_msg_channel_open_confirmation;
5849 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5850 ssh1_msg_channel_open_failure;
5851 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5852 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5853 ssh1_msg_channel_close;
5854 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5855 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5857 if (ssh_agent_forwarding_permitted(ssh)) {
5858 logevent("Requesting agent forwarding");
5859 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5863 if (pktin->type != SSH1_SMSG_SUCCESS
5864 && pktin->type != SSH1_SMSG_FAILURE) {
5865 bombout(("Protocol confusion"));
5867 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5868 logevent("Agent forwarding refused");
5870 logevent("Agent forwarding enabled");
5871 ssh->agentfwd_enabled = TRUE;
5872 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5876 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5878 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5880 if (!ssh->x11disp) {
5881 /* FIXME: return an error message from x11_setup_display */
5882 logevent("X11 forwarding not enabled: unable to"
5883 " initialise X display");
5885 ssh->x11auth = x11_invent_fake_auth
5886 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5887 ssh->x11auth->disp = ssh->x11disp;
5889 logevent("Requesting X11 forwarding");
5890 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5891 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5892 PKT_STR, ssh->x11auth->protoname,
5893 PKT_STR, ssh->x11auth->datastring,
5894 PKT_INT, ssh->x11disp->screennum,
5897 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5898 PKT_STR, ssh->x11auth->protoname,
5899 PKT_STR, ssh->x11auth->datastring,
5905 if (pktin->type != SSH1_SMSG_SUCCESS
5906 && pktin->type != SSH1_SMSG_FAILURE) {
5907 bombout(("Protocol confusion"));
5909 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5910 logevent("X11 forwarding refused");
5912 logevent("X11 forwarding enabled");
5913 ssh->X11_fwd_enabled = TRUE;
5914 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5919 ssh_setup_portfwd(ssh, ssh->conf);
5920 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5922 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5924 /* Unpick the terminal-speed string. */
5925 /* XXX perhaps we should allow no speeds to be sent. */
5926 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5927 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5928 /* Send the pty request. */
5929 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5930 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5931 ssh_pkt_adduint32(pkt, ssh->term_height);
5932 ssh_pkt_adduint32(pkt, ssh->term_width);
5933 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5934 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5935 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5936 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5937 ssh_pkt_adduint32(pkt, ssh->ispeed);
5938 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5939 ssh_pkt_adduint32(pkt, ssh->ospeed);
5940 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5942 ssh->state = SSH_STATE_INTERMED;
5946 if (pktin->type != SSH1_SMSG_SUCCESS
5947 && pktin->type != SSH1_SMSG_FAILURE) {
5948 bombout(("Protocol confusion"));
5950 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5951 c_write_str(ssh, "Server refused to allocate pty\r\n");
5952 ssh->editing = ssh->echoing = 1;
5954 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5955 ssh->ospeed, ssh->ispeed);
5956 ssh->got_pty = TRUE;
5959 ssh->editing = ssh->echoing = 1;
5962 if (conf_get_int(ssh->conf, CONF_compression)) {
5963 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5967 if (pktin->type != SSH1_SMSG_SUCCESS
5968 && pktin->type != SSH1_SMSG_FAILURE) {
5969 bombout(("Protocol confusion"));
5971 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5972 c_write_str(ssh, "Server refused to compress\r\n");
5974 logevent("Started compression");
5975 ssh->v1_compressing = TRUE;
5976 ssh->cs_comp_ctx = zlib_compress_init();
5977 logevent("Initialised zlib (RFC1950) compression");
5978 ssh->sc_comp_ctx = zlib_decompress_init();
5979 logevent("Initialised zlib (RFC1950) decompression");
5983 * Start the shell or command.
5985 * Special case: if the first-choice command is an SSH-2
5986 * subsystem (hence not usable here) and the second choice
5987 * exists, we fall straight back to that.
5990 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5992 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5993 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5994 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5995 ssh->fallback_cmd = TRUE;
5998 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6000 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6001 logevent("Started session");
6004 ssh->state = SSH_STATE_SESSION;
6005 if (ssh->size_needed)
6006 ssh_size(ssh, ssh->term_width, ssh->term_height);
6007 if (ssh->eof_needed)
6008 ssh_special(ssh, TS_EOF);
6011 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6013 ssh->channels = newtree234(ssh_channelcmp);
6017 * By this point, most incoming packets are already being
6018 * handled by the dispatch table, and we need only pay
6019 * attention to the unusual ones.
6024 if (pktin->type == SSH1_SMSG_SUCCESS) {
6025 /* may be from EXEC_SHELL on some servers */
6026 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6027 /* may be from EXEC_SHELL on some servers
6028 * if no pty is available or in other odd cases. Ignore */
6030 bombout(("Strange packet received: type %d", pktin->type));
6035 int len = min(inlen, 512);
6036 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6037 PKT_INT, len, PKT_DATA, in, len,
6049 * Handle the top-level SSH-2 protocol.
6051 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6056 ssh_pkt_getstring(pktin, &msg, &msglen);
6057 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6060 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6062 /* log reason code in disconnect message */
6066 ssh_pkt_getstring(pktin, &msg, &msglen);
6067 bombout(("Server sent disconnect message:\n\"%.*s\"",
6068 msglen, NULLTOEMPTY(msg)));
6071 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6073 /* Do nothing, because we're ignoring it! Duhh. */
6076 static void ssh1_protocol_setup(Ssh ssh)
6081 * Most messages are handled by the coroutines.
6083 for (i = 0; i < 256; i++)
6084 ssh->packet_dispatch[i] = NULL;
6087 * These special message types we install handlers for.
6089 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6090 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6091 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6094 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6095 struct Packet *pktin)
6097 const unsigned char *in = (const unsigned char *)vin;
6098 if (ssh->state == SSH_STATE_CLOSED)
6101 if (pktin && ssh->packet_dispatch[pktin->type]) {
6102 ssh->packet_dispatch[pktin->type](ssh, pktin);
6106 if (!ssh->protocol_initial_phase_done) {
6107 if (do_ssh1_login(ssh, in, inlen, pktin))
6108 ssh->protocol_initial_phase_done = TRUE;
6113 do_ssh1_connection(ssh, in, inlen, pktin);
6117 * Utility routines for decoding comma-separated strings in KEXINIT.
6119 static int first_in_commasep_string(char const *needle, char const *haystack,
6123 if (!needle || !haystack) /* protect against null pointers */
6125 needlen = strlen(needle);
6127 if (haylen >= needlen && /* haystack is long enough */
6128 !memcmp(needle, haystack, needlen) && /* initial match */
6129 (haylen == needlen || haystack[needlen] == ',')
6130 /* either , or EOS follows */
6136 static int in_commasep_string(char const *needle, char const *haystack,
6141 if (!needle || !haystack) /* protect against null pointers */
6144 * Is it at the start of the string?
6146 if (first_in_commasep_string(needle, haystack, haylen))
6149 * If not, search for the next comma and resume after that.
6150 * If no comma found, terminate.
6152 p = memchr(haystack, ',', haylen);
6154 /* + 1 to skip over comma */
6155 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6159 * Add a value to the comma-separated string at the end of the packet.
6161 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6163 if (pkt->length - pkt->savedpos > 0)
6164 ssh_pkt_addstring_str(pkt, ",");
6165 ssh_pkt_addstring_str(pkt, data);
6170 * SSH-2 key derivation (RFC 4253 section 7.2).
6172 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6173 char chr, int keylen)
6175 const struct ssh_hash *h = ssh->kex->hash;
6183 /* Round up to the next multiple of hash length. */
6184 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6186 key = snewn(keylen_padded, unsigned char);
6188 /* First hlen bytes. */
6190 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6191 hash_mpint(h, s, K);
6192 h->bytes(s, H, h->hlen);
6193 h->bytes(s, &chr, 1);
6194 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6197 /* Subsequent blocks of hlen bytes. */
6198 if (keylen_padded > h->hlen) {
6202 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6203 hash_mpint(h, s, K);
6204 h->bytes(s, H, h->hlen);
6206 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6207 h->bytes(s, key + offset - h->hlen, h->hlen);
6209 h->final(s2, key + offset);
6215 /* Now clear any extra bytes of key material beyond the length
6216 * we're officially returning, because the caller won't know to
6218 if (keylen_padded > keylen)
6219 smemclr(key + keylen, keylen_padded - keylen);
6225 * Structure for constructing KEXINIT algorithm lists.
6227 #define MAXKEXLIST 16
6228 struct kexinit_algorithm {
6232 const struct ssh_kex *kex;
6236 const struct ssh_signkey *hostkey;
6240 const struct ssh2_cipher *cipher;
6244 const struct ssh_mac *mac;
6247 const struct ssh_compress *comp;
6252 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6253 * If the algorithm is already in the list, return a pointer to its
6254 * entry, otherwise return an entry from the end of the list.
6255 * This assumes that every time a particular name is passed in, it
6256 * comes from the same string constant. If this isn't true, this
6257 * function may need to be rewritten to use strcmp() instead.
6259 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6260 *list, const char *name)
6264 for (i = 0; i < MAXKEXLIST; i++)
6265 if (list[i].name == NULL || list[i].name == name) {
6266 list[i].name = name;
6269 assert(!"No space in KEXINIT list");
6274 * Handle the SSH-2 transport layer.
6276 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6277 struct Packet *pktin)
6279 const unsigned char *in = (const unsigned char *)vin;
6281 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6282 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6285 const char * kexlist_descr[NKEXLIST] = {
6286 "key exchange algorithm", "host key algorithm",
6287 "client-to-server cipher", "server-to-client cipher",
6288 "client-to-server MAC", "server-to-client MAC",
6289 "client-to-server compression method",
6290 "server-to-client compression method" };
6291 struct do_ssh2_transport_state {
6293 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6294 Bignum p, g, e, f, K;
6297 int kex_init_value, kex_reply_value;
6298 const struct ssh_mac *const *maclist;
6300 const struct ssh2_cipher *cscipher_tobe;
6301 const struct ssh2_cipher *sccipher_tobe;
6302 const struct ssh_mac *csmac_tobe;
6303 const struct ssh_mac *scmac_tobe;
6304 int csmac_etm_tobe, scmac_etm_tobe;
6305 const struct ssh_compress *cscomp_tobe;
6306 const struct ssh_compress *sccomp_tobe;
6307 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6308 int hostkeylen, siglen, rsakeylen;
6309 void *hkey; /* actual host key */
6310 void *rsakey; /* for RSA kex */
6311 void *eckey; /* for ECDH kex */
6312 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6313 int n_preferred_kex;
6314 const struct ssh_kexes *preferred_kex[KEX_MAX];
6316 int preferred_hk[HK_MAX];
6317 int n_preferred_ciphers;
6318 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6319 const struct ssh_compress *preferred_comp;
6320 int userauth_succeeded; /* for delayed compression */
6321 int pending_compression;
6322 int got_session_id, activated_authconn;
6323 struct Packet *pktout;
6327 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6329 crState(do_ssh2_transport_state);
6331 assert(!ssh->bare_connection);
6332 assert(ssh->version == 2);
6336 s->cscipher_tobe = s->sccipher_tobe = NULL;
6337 s->csmac_tobe = s->scmac_tobe = NULL;
6338 s->cscomp_tobe = s->sccomp_tobe = NULL;
6340 s->got_session_id = s->activated_authconn = FALSE;
6341 s->userauth_succeeded = FALSE;
6342 s->pending_compression = FALSE;
6345 * Be prepared to work around the buggy MAC problem.
6347 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6348 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6350 s->maclist = macs, s->nmacs = lenof(macs);
6353 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6356 struct kexinit_algorithm *alg;
6359 * Set up the preferred key exchange. (NULL => warn below here)
6361 s->n_preferred_kex = 0;
6362 for (i = 0; i < KEX_MAX; i++) {
6363 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6365 s->preferred_kex[s->n_preferred_kex++] =
6366 &ssh_diffiehellman_gex;
6369 s->preferred_kex[s->n_preferred_kex++] =
6370 &ssh_diffiehellman_group14;
6373 s->preferred_kex[s->n_preferred_kex++] =
6374 &ssh_diffiehellman_group1;
6377 s->preferred_kex[s->n_preferred_kex++] =
6381 s->preferred_kex[s->n_preferred_kex++] =
6385 /* Flag for later. Don't bother if it's the last in
6387 if (i < KEX_MAX - 1) {
6388 s->preferred_kex[s->n_preferred_kex++] = NULL;
6395 * Set up the preferred host key types. These are just the ids
6396 * in the enum in putty.h, so 'warn below here' is indicated
6399 s->n_preferred_hk = 0;
6400 for (i = 0; i < HK_MAX; i++) {
6401 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6402 /* As above, don't bother with HK_WARN if it's last in the
6404 if (id != HK_WARN || i < HK_MAX - 1)
6405 s->preferred_hk[s->n_preferred_hk++] = id;
6409 * Set up the preferred ciphers. (NULL => warn below here)
6411 s->n_preferred_ciphers = 0;
6412 for (i = 0; i < CIPHER_MAX; i++) {
6413 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6414 case CIPHER_BLOWFISH:
6415 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6418 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6419 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6423 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6426 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6428 case CIPHER_ARCFOUR:
6429 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6431 case CIPHER_CHACHA20:
6432 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6435 /* Flag for later. Don't bother if it's the last in
6437 if (i < CIPHER_MAX - 1) {
6438 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6445 * Set up preferred compression.
6447 if (conf_get_int(ssh->conf, CONF_compression))
6448 s->preferred_comp = &ssh_zlib;
6450 s->preferred_comp = &ssh_comp_none;
6453 * Enable queueing of outgoing auth- or connection-layer
6454 * packets while we are in the middle of a key exchange.
6456 ssh->queueing = TRUE;
6459 * Flag that KEX is in progress.
6461 ssh->kex_in_progress = TRUE;
6463 for (i = 0; i < NKEXLIST; i++)
6464 for (j = 0; j < MAXKEXLIST; j++)
6465 s->kexlists[i][j].name = NULL;
6466 /* List key exchange algorithms. */
6468 for (i = 0; i < s->n_preferred_kex; i++) {
6469 const struct ssh_kexes *k = s->preferred_kex[i];
6470 if (!k) warn = TRUE;
6471 else for (j = 0; j < k->nkexes; j++) {
6472 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6474 alg->u.kex.kex = k->list[j];
6475 alg->u.kex.warn = warn;
6478 /* List server host key algorithms. */
6479 if (!s->got_session_id) {
6481 * In the first key exchange, we list all the algorithms
6482 * we're prepared to cope with, but prefer those algorithms
6483 * for which we have a host key for this host.
6485 * If the host key algorithm is below the warning
6486 * threshold, we warn even if we did already have a key
6487 * for it, on the basis that if the user has just
6488 * reconfigured that host key type to be warned about,
6489 * they surely _do_ want to be alerted that a server
6490 * they're actually connecting to is using it.
6493 for (i = 0; i < s->n_preferred_hk; i++) {
6494 if (s->preferred_hk[i] == HK_WARN)
6496 for (j = 0; j < lenof(hostkey_algs); j++) {
6497 if (hostkey_algs[j].id != s->preferred_hk[i])
6499 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6500 hostkey_algs[j].alg->keytype)) {
6501 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6502 hostkey_algs[j].alg->name);
6503 alg->u.hk.hostkey = hostkey_algs[j].alg;
6504 alg->u.hk.warn = warn;
6509 for (i = 0; i < s->n_preferred_hk; i++) {
6510 if (s->preferred_hk[i] == HK_WARN)
6512 for (j = 0; j < lenof(hostkey_algs); j++) {
6513 if (hostkey_algs[j].id != s->preferred_hk[i])
6515 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6516 hostkey_algs[j].alg->name);
6517 alg->u.hk.hostkey = hostkey_algs[j].alg;
6518 alg->u.hk.warn = warn;
6523 * In subsequent key exchanges, we list only the kex
6524 * algorithm that was selected in the first key exchange,
6525 * so that we keep getting the same host key and hence
6526 * don't have to interrupt the user's session to ask for
6530 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6531 ssh->hostkey->name);
6532 alg->u.hk.hostkey = ssh->hostkey;
6533 alg->u.hk.warn = FALSE;
6535 /* List encryption algorithms (client->server then server->client). */
6536 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6539 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6540 alg->u.cipher.cipher = NULL;
6541 alg->u.cipher.warn = warn;
6542 #endif /* FUZZING */
6543 for (i = 0; i < s->n_preferred_ciphers; i++) {
6544 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6545 if (!c) warn = TRUE;
6546 else for (j = 0; j < c->nciphers; j++) {
6547 alg = ssh2_kexinit_addalg(s->kexlists[k],
6549 alg->u.cipher.cipher = c->list[j];
6550 alg->u.cipher.warn = warn;
6554 /* List MAC algorithms (client->server then server->client). */
6555 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6557 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6558 alg->u.mac.mac = NULL;
6559 alg->u.mac.etm = FALSE;
6560 #endif /* FUZZING */
6561 for (i = 0; i < s->nmacs; i++) {
6562 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6563 alg->u.mac.mac = s->maclist[i];
6564 alg->u.mac.etm = FALSE;
6566 for (i = 0; i < s->nmacs; i++)
6567 /* For each MAC, there may also be an ETM version,
6568 * which we list second. */
6569 if (s->maclist[i]->etm_name) {
6570 alg = ssh2_kexinit_addalg(s->kexlists[j],
6571 s->maclist[i]->etm_name);
6572 alg->u.mac.mac = s->maclist[i];
6573 alg->u.mac.etm = TRUE;
6576 /* List client->server compression algorithms,
6577 * then server->client compression algorithms. (We use the
6578 * same set twice.) */
6579 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6580 assert(lenof(compressions) > 1);
6581 /* Prefer non-delayed versions */
6582 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6583 alg->u.comp = s->preferred_comp;
6584 /* We don't even list delayed versions of algorithms until
6585 * they're allowed to be used, to avoid a race. See the end of
6587 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6588 alg = ssh2_kexinit_addalg(s->kexlists[j],
6589 s->preferred_comp->delayed_name);
6590 alg->u.comp = s->preferred_comp;
6592 for (i = 0; i < lenof(compressions); i++) {
6593 const struct ssh_compress *c = compressions[i];
6594 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6596 if (s->userauth_succeeded && c->delayed_name) {
6597 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6603 * Construct and send our key exchange packet.
6605 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6606 for (i = 0; i < 16; i++)
6607 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6608 for (i = 0; i < NKEXLIST; i++) {
6609 ssh2_pkt_addstring_start(s->pktout);
6610 for (j = 0; j < MAXKEXLIST; j++) {
6611 if (s->kexlists[i][j].name == NULL) break;
6612 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6615 /* List client->server languages. Empty list. */
6616 ssh2_pkt_addstring_start(s->pktout);
6617 /* List server->client languages. Empty list. */
6618 ssh2_pkt_addstring_start(s->pktout);
6619 /* First KEX packet does _not_ follow, because we're not that brave. */
6620 ssh2_pkt_addbool(s->pktout, FALSE);
6622 ssh2_pkt_adduint32(s->pktout, 0);
6625 s->our_kexinitlen = s->pktout->length - 5;
6626 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6627 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6629 ssh2_pkt_send_noqueue(ssh, s->pktout);
6632 crWaitUntilV(pktin);
6635 * Now examine the other side's KEXINIT to see what we're up
6642 if (pktin->type != SSH2_MSG_KEXINIT) {
6643 bombout(("expected key exchange packet from server"));
6647 ssh->hostkey = NULL;
6648 s->cscipher_tobe = NULL;
6649 s->sccipher_tobe = NULL;
6650 s->csmac_tobe = NULL;
6651 s->scmac_tobe = NULL;
6652 s->cscomp_tobe = NULL;
6653 s->sccomp_tobe = NULL;
6654 s->warn_kex = s->warn_hk = FALSE;
6655 s->warn_cscipher = s->warn_sccipher = FALSE;
6657 pktin->savedpos += 16; /* skip garbage cookie */
6660 for (i = 0; i < NKEXLIST; i++) {
6661 ssh_pkt_getstring(pktin, &str, &len);
6663 bombout(("KEXINIT packet was incomplete"));
6667 /* If we've already selected a cipher which requires a
6668 * particular MAC, then just select that, and don't even
6669 * bother looking through the server's KEXINIT string for
6671 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6672 s->cscipher_tobe->required_mac) {
6673 s->csmac_tobe = s->cscipher_tobe->required_mac;
6674 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6677 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6678 s->sccipher_tobe->required_mac) {
6679 s->scmac_tobe = s->sccipher_tobe->required_mac;
6680 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6684 for (j = 0; j < MAXKEXLIST; j++) {
6685 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6686 if (alg->name == NULL) break;
6687 if (in_commasep_string(alg->name, str, len)) {
6688 /* We've found a matching algorithm. */
6689 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6690 /* Check if we might need to ignore first kex pkt */
6692 !first_in_commasep_string(alg->name, str, len))
6695 if (i == KEXLIST_KEX) {
6696 ssh->kex = alg->u.kex.kex;
6697 s->warn_kex = alg->u.kex.warn;
6698 } else if (i == KEXLIST_HOSTKEY) {
6699 ssh->hostkey = alg->u.hk.hostkey;
6700 s->warn_hk = alg->u.hk.warn;
6701 } else if (i == KEXLIST_CSCIPHER) {
6702 s->cscipher_tobe = alg->u.cipher.cipher;
6703 s->warn_cscipher = alg->u.cipher.warn;
6704 } else if (i == KEXLIST_SCCIPHER) {
6705 s->sccipher_tobe = alg->u.cipher.cipher;
6706 s->warn_sccipher = alg->u.cipher.warn;
6707 } else if (i == KEXLIST_CSMAC) {
6708 s->csmac_tobe = alg->u.mac.mac;
6709 s->csmac_etm_tobe = alg->u.mac.etm;
6710 } else if (i == KEXLIST_SCMAC) {
6711 s->scmac_tobe = alg->u.mac.mac;
6712 s->scmac_etm_tobe = alg->u.mac.etm;
6713 } else if (i == KEXLIST_CSCOMP) {
6714 s->cscomp_tobe = alg->u.comp;
6715 } else if (i == KEXLIST_SCCOMP) {
6716 s->sccomp_tobe = alg->u.comp;
6720 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6721 in_commasep_string(alg->u.comp->delayed_name, str, len))
6722 s->pending_compression = TRUE; /* try this later */
6724 bombout(("Couldn't agree a %s (available: %.*s)",
6725 kexlist_descr[i], len, str));
6729 if (i == KEXLIST_HOSTKEY) {
6733 * In addition to deciding which host key we're
6734 * actually going to use, we should make a list of the
6735 * host keys offered by the server which we _don't_
6736 * have cached. These will be offered as cross-
6737 * certification options by ssh_get_specials.
6739 * We also count the key we're currently using for KEX
6740 * as one we've already got, because by the time this
6741 * menu becomes visible, it will be.
6743 ssh->n_uncert_hostkeys = 0;
6745 for (j = 0; j < lenof(hostkey_algs); j++) {
6746 if (hostkey_algs[j].alg != ssh->hostkey &&
6747 in_commasep_string(hostkey_algs[j].alg->name,
6749 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6750 hostkey_algs[j].alg->keytype)) {
6751 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6757 if (s->pending_compression) {
6758 logevent("Server supports delayed compression; "
6759 "will try this later");
6761 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6762 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6763 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6765 ssh->exhash = ssh->kex->hash->init();
6766 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6767 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6768 hash_string(ssh->kex->hash, ssh->exhash,
6769 s->our_kexinit, s->our_kexinitlen);
6770 sfree(s->our_kexinit);
6771 /* Include the type byte in the hash of server's KEXINIT */
6772 hash_string(ssh->kex->hash, ssh->exhash,
6773 pktin->body - 1, pktin->length + 1);
6776 ssh_set_frozen(ssh, 1);
6777 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6779 ssh_dialog_callback, ssh);
6780 if (s->dlgret < 0) {
6784 bombout(("Unexpected data from server while"
6785 " waiting for user response"));
6788 } while (pktin || inlen > 0);
6789 s->dlgret = ssh->user_response;
6791 ssh_set_frozen(ssh, 0);
6792 if (s->dlgret == 0) {
6793 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6803 ssh_set_frozen(ssh, 1);
6806 * Change warning box wording depending on why we chose a
6807 * warning-level host key algorithm. If it's because
6808 * that's all we have *cached*, use the askhk mechanism,
6809 * and list the host keys we could usefully cross-certify.
6810 * Otherwise, use askalg for the standard wording.
6813 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6814 const struct ssh_signkey_with_user_pref_id *hktype =
6815 &hostkey_algs[ssh->uncert_hostkeys[j]];
6817 for (k = 0; k < HK_MAX; k++) {
6818 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6819 if (id == HK_WARN) {
6821 } else if (id == hktype->id) {
6828 char *old_ba = betteralgs;
6829 betteralgs = dupcat(betteralgs, ",",
6831 (const char *)NULL);
6834 betteralgs = dupstr(hktype->alg->name);
6839 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6840 betteralgs, ssh_dialog_callback, ssh);
6843 s->dlgret = askalg(ssh->frontend, "host key type",
6845 ssh_dialog_callback, ssh);
6847 if (s->dlgret < 0) {
6851 bombout(("Unexpected data from server while"
6852 " waiting for user response"));
6855 } while (pktin || inlen > 0);
6856 s->dlgret = ssh->user_response;
6858 ssh_set_frozen(ssh, 0);
6859 if (s->dlgret == 0) {
6860 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6866 if (s->warn_cscipher) {
6867 ssh_set_frozen(ssh, 1);
6868 s->dlgret = askalg(ssh->frontend,
6869 "client-to-server cipher",
6870 s->cscipher_tobe->name,
6871 ssh_dialog_callback, ssh);
6872 if (s->dlgret < 0) {
6876 bombout(("Unexpected data from server while"
6877 " waiting for user response"));
6880 } while (pktin || inlen > 0);
6881 s->dlgret = ssh->user_response;
6883 ssh_set_frozen(ssh, 0);
6884 if (s->dlgret == 0) {
6885 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6891 if (s->warn_sccipher) {
6892 ssh_set_frozen(ssh, 1);
6893 s->dlgret = askalg(ssh->frontend,
6894 "server-to-client cipher",
6895 s->sccipher_tobe->name,
6896 ssh_dialog_callback, ssh);
6897 if (s->dlgret < 0) {
6901 bombout(("Unexpected data from server while"
6902 " waiting for user response"));
6905 } while (pktin || inlen > 0);
6906 s->dlgret = ssh->user_response;
6908 ssh_set_frozen(ssh, 0);
6909 if (s->dlgret == 0) {
6910 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6916 if (s->ignorepkt) /* first_kex_packet_follows */
6917 crWaitUntilV(pktin); /* Ignore packet */
6920 if (ssh->kex->main_type == KEXTYPE_DH) {
6922 * Work out the number of bits of key we will need from the
6923 * key exchange. We start with the maximum key length of
6929 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6930 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6931 s->nbits = (csbits > scbits ? csbits : scbits);
6933 /* The keys only have hlen-bit entropy, since they're based on
6934 * a hash. So cap the key size at hlen bits. */
6935 if (s->nbits > ssh->kex->hash->hlen * 8)
6936 s->nbits = ssh->kex->hash->hlen * 8;
6939 * If we're doing Diffie-Hellman group exchange, start by
6940 * requesting a group.
6942 if (dh_is_gex(ssh->kex)) {
6943 logevent("Doing Diffie-Hellman group exchange");
6944 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6946 * Work out how big a DH group we will need to allow that
6949 s->pbits = 512 << ((s->nbits - 1) / 64);
6950 if (s->pbits < DH_MIN_SIZE)
6951 s->pbits = DH_MIN_SIZE;
6952 if (s->pbits > DH_MAX_SIZE)
6953 s->pbits = DH_MAX_SIZE;
6954 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6955 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6956 ssh2_pkt_adduint32(s->pktout, s->pbits);
6958 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6959 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6960 ssh2_pkt_adduint32(s->pktout, s->pbits);
6961 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6963 ssh2_pkt_send_noqueue(ssh, s->pktout);
6965 crWaitUntilV(pktin);
6966 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6967 bombout(("expected key exchange group packet from server"));
6970 s->p = ssh2_pkt_getmp(pktin);
6971 s->g = ssh2_pkt_getmp(pktin);
6972 if (!s->p || !s->g) {
6973 bombout(("unable to read mp-ints from incoming group packet"));
6976 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6977 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6978 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6980 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6981 ssh->kex_ctx = dh_setup_group(ssh->kex);
6982 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6983 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6984 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6985 ssh->kex->groupname);
6988 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6989 ssh->kex->hash->text_name);
6991 * Now generate and send e for Diffie-Hellman.
6993 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6994 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6995 s->pktout = ssh2_pkt_init(s->kex_init_value);
6996 ssh2_pkt_addmp(s->pktout, s->e);
6997 ssh2_pkt_send_noqueue(ssh, s->pktout);
6999 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
7000 crWaitUntilV(pktin);
7001 if (pktin->type != s->kex_reply_value) {
7002 bombout(("expected key exchange reply packet from server"));
7005 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
7006 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7007 if (!s->hostkeydata) {
7008 bombout(("unable to parse key exchange reply packet"));
7011 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7012 s->hostkeydata, s->hostkeylen);
7013 s->f = ssh2_pkt_getmp(pktin);
7015 bombout(("unable to parse key exchange reply packet"));
7018 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7020 bombout(("unable to parse key exchange reply packet"));
7025 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7027 bombout(("key exchange reply failed validation: %s", err));
7031 s->K = dh_find_K(ssh->kex_ctx, s->f);
7033 /* We assume everything from now on will be quick, and it might
7034 * involve user interaction. */
7035 set_busy_status(ssh->frontend, BUSY_NOT);
7037 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7038 if (dh_is_gex(ssh->kex)) {
7039 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7040 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7041 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7042 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7043 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7044 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7045 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7047 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7048 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7050 dh_cleanup(ssh->kex_ctx);
7052 if (dh_is_gex(ssh->kex)) {
7056 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7058 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7059 ssh_ecdhkex_curve_textname(ssh->kex),
7060 ssh->kex->hash->text_name);
7061 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7063 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7065 bombout(("Unable to generate key for ECDH"));
7071 int publicPointLength;
7072 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7074 ssh_ecdhkex_freekey(s->eckey);
7075 bombout(("Unable to encode public key for ECDH"));
7078 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7079 ssh2_pkt_addstring_start(s->pktout);
7080 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7084 ssh2_pkt_send_noqueue(ssh, s->pktout);
7086 crWaitUntilV(pktin);
7087 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7088 ssh_ecdhkex_freekey(s->eckey);
7089 bombout(("expected ECDH reply packet from server"));
7093 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7094 if (!s->hostkeydata) {
7095 bombout(("unable to parse ECDH reply packet"));
7098 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7099 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7100 s->hostkeydata, s->hostkeylen);
7104 int publicPointLength;
7105 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7107 ssh_ecdhkex_freekey(s->eckey);
7108 bombout(("Unable to encode public key for ECDH hash"));
7111 hash_string(ssh->kex->hash, ssh->exhash,
7112 publicPoint, publicPointLength);
7119 ssh_pkt_getstring(pktin, &keydata, &keylen);
7121 bombout(("unable to parse ECDH reply packet"));
7124 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7125 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7127 ssh_ecdhkex_freekey(s->eckey);
7128 bombout(("point received in ECDH was not valid"));
7133 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7135 bombout(("unable to parse key exchange reply packet"));
7139 ssh_ecdhkex_freekey(s->eckey);
7141 logeventf(ssh, "Doing RSA key exchange with hash %s",
7142 ssh->kex->hash->text_name);
7143 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7145 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7148 crWaitUntilV(pktin);
7149 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7150 bombout(("expected RSA public key packet from server"));
7154 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7155 if (!s->hostkeydata) {
7156 bombout(("unable to parse RSA public key packet"));
7159 hash_string(ssh->kex->hash, ssh->exhash,
7160 s->hostkeydata, s->hostkeylen);
7161 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7162 s->hostkeydata, s->hostkeylen);
7166 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7168 bombout(("unable to parse RSA public key packet"));
7171 s->rsakeydata = snewn(s->rsakeylen, char);
7172 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7175 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7177 sfree(s->rsakeydata);
7178 bombout(("unable to parse RSA public key from server"));
7182 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7185 * Next, set up a shared secret K, of precisely KLEN -
7186 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7187 * RSA key modulus and HLEN is the bit length of the hash
7191 int klen = ssh_rsakex_klen(s->rsakey);
7192 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7194 unsigned char *kstr1, *kstr2, *outstr;
7195 int kstr1len, kstr2len, outstrlen;
7197 s->K = bn_power_2(nbits - 1);
7199 for (i = 0; i < nbits; i++) {
7201 byte = random_byte();
7203 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7207 * Encode this as an mpint.
7209 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7210 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7211 PUT_32BIT(kstr2, kstr1len);
7212 memcpy(kstr2 + 4, kstr1, kstr1len);
7215 * Encrypt it with the given RSA key.
7217 outstrlen = (klen + 7) / 8;
7218 outstr = snewn(outstrlen, unsigned char);
7219 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7220 outstr, outstrlen, s->rsakey);
7223 * And send it off in a return packet.
7225 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7226 ssh2_pkt_addstring_start(s->pktout);
7227 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7228 ssh2_pkt_send_noqueue(ssh, s->pktout);
7230 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7237 ssh_rsakex_freekey(s->rsakey);
7239 crWaitUntilV(pktin);
7240 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7241 sfree(s->rsakeydata);
7242 bombout(("expected signature packet from server"));
7246 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7248 bombout(("unable to parse signature packet"));
7252 sfree(s->rsakeydata);
7255 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7256 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7257 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7259 ssh->kex_ctx = NULL;
7262 debug(("Exchange hash is:\n"));
7263 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7267 bombout(("Server's host key is invalid"));
7271 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7272 (char *)s->exchange_hash,
7273 ssh->kex->hash->hlen)) {
7275 bombout(("Server's host key did not match the signature supplied"));
7280 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7281 if (!s->got_session_id) {
7283 * Make a note of any other host key formats that are available.
7286 int i, j, nkeys = 0;
7288 for (i = 0; i < lenof(hostkey_algs); i++) {
7289 if (hostkey_algs[i].alg == ssh->hostkey)
7292 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7293 if (ssh->uncert_hostkeys[j] == i)
7296 if (j < ssh->n_uncert_hostkeys) {
7299 newlist = dupprintf("%s/%s", list,
7300 hostkey_algs[i].alg->name);
7302 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7310 "Server also has %s host key%s, but we "
7311 "don't know %s", list,
7312 nkeys > 1 ? "s" : "",
7313 nkeys > 1 ? "any of them" : "it");
7319 * Authenticate remote host: verify host key. (We've already
7320 * checked the signature of the exchange hash.)
7322 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7323 logevent("Host key fingerprint is:");
7324 logevent(s->fingerprint);
7325 /* First check against manually configured host keys. */
7326 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7327 ssh->hostkey, s->hkey);
7328 if (s->dlgret == 0) { /* did not match */
7329 bombout(("Host key did not appear in manually configured list"));
7331 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7332 ssh_set_frozen(ssh, 1);
7333 s->dlgret = verify_ssh_host_key(ssh->frontend,
7334 ssh->savedhost, ssh->savedport,
7335 ssh->hostkey->keytype, s->keystr,
7337 ssh_dialog_callback, ssh);
7341 if (s->dlgret < 0) {
7345 bombout(("Unexpected data from server while waiting"
7346 " for user host key response"));
7349 } while (pktin || inlen > 0);
7350 s->dlgret = ssh->user_response;
7352 ssh_set_frozen(ssh, 0);
7353 if (s->dlgret == 0) {
7354 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7359 sfree(s->fingerprint);
7361 * Save this host key, to check against the one presented in
7362 * subsequent rekeys.
7364 ssh->hostkey_str = s->keystr;
7365 } else if (ssh->cross_certifying) {
7366 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7367 logevent("Storing additional host key for this host:");
7368 logevent(s->fingerprint);
7369 store_host_key(ssh->savedhost, ssh->savedport,
7370 ssh->hostkey->keytype, s->keystr);
7371 ssh->cross_certifying = FALSE;
7373 * Don't forget to store the new key as the one we'll be
7374 * re-checking in future normal rekeys.
7376 ssh->hostkey_str = s->keystr;
7379 * In a rekey, we never present an interactive host key
7380 * verification request to the user. Instead, we simply
7381 * enforce that the key we're seeing this time is identical to
7382 * the one we saw before.
7384 if (strcmp(ssh->hostkey_str, s->keystr)) {
7386 bombout(("Host key was different in repeat key exchange"));
7392 ssh->hostkey->freekey(s->hkey);
7395 * The exchange hash from the very first key exchange is also
7396 * the session id, used in session key construction and
7399 if (!s->got_session_id) {
7400 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7401 memcpy(ssh->v2_session_id, s->exchange_hash,
7402 sizeof(s->exchange_hash));
7403 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7404 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7405 s->got_session_id = TRUE;
7409 * Send SSH2_MSG_NEWKEYS.
7411 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7412 ssh2_pkt_send_noqueue(ssh, s->pktout);
7413 ssh->outgoing_data_size = 0; /* start counting from here */
7416 * We've sent client NEWKEYS, so create and initialise
7417 * client-to-server session keys.
7419 if (ssh->cs_cipher_ctx)
7420 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7421 ssh->cscipher = s->cscipher_tobe;
7422 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7424 if (ssh->cs_mac_ctx)
7425 ssh->csmac->free_context(ssh->cs_mac_ctx);
7426 ssh->csmac = s->csmac_tobe;
7427 ssh->csmac_etm = s->csmac_etm_tobe;
7429 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7431 if (ssh->cs_comp_ctx)
7432 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7433 ssh->cscomp = s->cscomp_tobe;
7434 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7437 * Set IVs on client-to-server keys. Here we use the exchange
7438 * hash from the _first_ key exchange.
7440 if (ssh->cscipher) {
7443 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7444 ssh->cscipher->padded_keybytes);
7445 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7446 smemclr(key, ssh->cscipher->padded_keybytes);
7449 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7450 ssh->cscipher->blksize);
7451 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7452 smemclr(key, ssh->cscipher->blksize);
7458 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7459 ssh->csmac->keylen);
7460 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7461 smemclr(key, ssh->csmac->keylen);
7466 logeventf(ssh, "Initialised %.200s client->server encryption",
7467 ssh->cscipher->text_name);
7469 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7470 ssh->csmac->text_name,
7471 ssh->csmac_etm ? " (in ETM mode)" : "",
7472 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7473 if (ssh->cscomp->text_name)
7474 logeventf(ssh, "Initialised %s compression",
7475 ssh->cscomp->text_name);
7478 * Now our end of the key exchange is complete, we can send all
7479 * our queued higher-layer packets.
7481 ssh->queueing = FALSE;
7482 ssh2_pkt_queuesend(ssh);
7485 * Expect SSH2_MSG_NEWKEYS from server.
7487 crWaitUntilV(pktin);
7488 if (pktin->type != SSH2_MSG_NEWKEYS) {
7489 bombout(("expected new-keys packet from server"));
7492 ssh->incoming_data_size = 0; /* start counting from here */
7495 * We've seen server NEWKEYS, so create and initialise
7496 * server-to-client session keys.
7498 if (ssh->sc_cipher_ctx)
7499 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7500 if (s->sccipher_tobe) {
7501 ssh->sccipher = s->sccipher_tobe;
7502 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7505 if (ssh->sc_mac_ctx)
7506 ssh->scmac->free_context(ssh->sc_mac_ctx);
7507 if (s->scmac_tobe) {
7508 ssh->scmac = s->scmac_tobe;
7509 ssh->scmac_etm = s->scmac_etm_tobe;
7510 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7513 if (ssh->sc_comp_ctx)
7514 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7515 ssh->sccomp = s->sccomp_tobe;
7516 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7519 * Set IVs on server-to-client keys. Here we use the exchange
7520 * hash from the _first_ key exchange.
7522 if (ssh->sccipher) {
7525 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7526 ssh->sccipher->padded_keybytes);
7527 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7528 smemclr(key, ssh->sccipher->padded_keybytes);
7531 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7532 ssh->sccipher->blksize);
7533 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7534 smemclr(key, ssh->sccipher->blksize);
7540 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7541 ssh->scmac->keylen);
7542 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7543 smemclr(key, ssh->scmac->keylen);
7547 logeventf(ssh, "Initialised %.200s server->client encryption",
7548 ssh->sccipher->text_name);
7550 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7551 ssh->scmac->text_name,
7552 ssh->scmac_etm ? " (in ETM mode)" : "",
7553 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7554 if (ssh->sccomp->text_name)
7555 logeventf(ssh, "Initialised %s decompression",
7556 ssh->sccomp->text_name);
7559 * Free shared secret.
7564 * Update the specials menu to list the remaining uncertified host
7567 update_specials_menu(ssh->frontend);
7570 * Key exchange is over. Loop straight back round if we have a
7571 * deferred rekey reason.
7573 if (ssh->deferred_rekey_reason) {
7574 logevent(ssh->deferred_rekey_reason);
7576 ssh->deferred_rekey_reason = NULL;
7577 goto begin_key_exchange;
7581 * Otherwise, schedule a timer for our next rekey.
7583 ssh->kex_in_progress = FALSE;
7584 ssh->last_rekey = GETTICKCOUNT();
7585 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7586 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7590 * Now we're encrypting. Begin returning 1 to the protocol main
7591 * function so that other things can run on top of the
7592 * transport. If we ever see a KEXINIT, we must go back to the
7595 * We _also_ go back to the start if we see pktin==NULL and
7596 * inlen negative, because this is a special signal meaning
7597 * `initiate client-driven rekey', and `in' contains a message
7598 * giving the reason for the rekey.
7600 * inlen==-1 means always initiate a rekey;
7601 * inlen==-2 means that userauth has completed successfully and
7602 * we should consider rekeying (for delayed compression).
7604 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7605 (!pktin && inlen < 0))) {
7607 if (!ssh->protocol_initial_phase_done) {
7608 ssh->protocol_initial_phase_done = TRUE;
7610 * Allow authconn to initialise itself.
7612 do_ssh2_authconn(ssh, NULL, 0, NULL);
7617 logevent("Server initiated key re-exchange");
7621 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7622 * delayed compression, if it's available.
7624 * draft-miller-secsh-compression-delayed-00 says that you
7625 * negotiate delayed compression in the first key exchange, and
7626 * both sides start compressing when the server has sent
7627 * USERAUTH_SUCCESS. This has a race condition -- the server
7628 * can't know when the client has seen it, and thus which incoming
7629 * packets it should treat as compressed.
7631 * Instead, we do the initial key exchange without offering the
7632 * delayed methods, but note if the server offers them; when we
7633 * get here, if a delayed method was available that was higher
7634 * on our list than what we got, we initiate a rekey in which we
7635 * _do_ list the delayed methods (and hopefully get it as a
7636 * result). Subsequent rekeys will do the same.
7638 assert(!s->userauth_succeeded); /* should only happen once */
7639 s->userauth_succeeded = TRUE;
7640 if (!s->pending_compression)
7641 /* Can't see any point rekeying. */
7642 goto wait_for_rekey; /* this is utterly horrid */
7643 /* else fall through to rekey... */
7644 s->pending_compression = FALSE;
7647 * Now we've decided to rekey.
7649 * Special case: if the server bug is set that doesn't
7650 * allow rekeying, we give a different log message and
7651 * continue waiting. (If such a server _initiates_ a rekey,
7652 * we process it anyway!)
7654 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7655 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7657 /* Reset the counters, so that at least this message doesn't
7658 * hit the event log _too_ often. */
7659 ssh->outgoing_data_size = 0;
7660 ssh->incoming_data_size = 0;
7661 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7663 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7666 goto wait_for_rekey; /* this is still utterly horrid */
7668 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7671 goto begin_key_exchange;
7677 * Send data on an SSH channel. In SSH-2, this involves buffering it
7680 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7683 if (c->ssh->version == 2) {
7684 bufchain_add(&c->v.v2.outbuffer, buf, len);
7685 return ssh2_try_send(c);
7687 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7688 PKT_INT, c->remoteid,
7693 * In SSH-1 we can return 0 here - implying that channels are
7694 * never individually throttled - because the only
7695 * circumstance that can cause throttling will be the whole
7696 * SSH connection backing up, in which case _everything_ will
7697 * be throttled as a whole.
7704 * Attempt to send data on an SSH-2 channel.
7706 static int ssh2_try_send(struct ssh_channel *c)
7709 struct Packet *pktout;
7712 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7715 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7716 if ((unsigned)len > c->v.v2.remwindow)
7717 len = c->v.v2.remwindow;
7718 if ((unsigned)len > c->v.v2.remmaxpkt)
7719 len = c->v.v2.remmaxpkt;
7720 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7721 ssh2_pkt_adduint32(pktout, c->remoteid);
7722 ssh2_pkt_addstring_start(pktout);
7723 ssh2_pkt_addstring_data(pktout, data, len);
7724 ssh2_pkt_send(ssh, pktout);
7725 bufchain_consume(&c->v.v2.outbuffer, len);
7726 c->v.v2.remwindow -= len;
7730 * After having sent as much data as we can, return the amount
7733 ret = bufchain_size(&c->v.v2.outbuffer);
7736 * And if there's no data pending but we need to send an EOF, send
7739 if (!ret && c->pending_eof)
7740 ssh_channel_try_eof(c);
7745 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7748 if (c->closes & CLOSES_SENT_EOF)
7749 return; /* don't send on channels we've EOFed */
7750 bufsize = ssh2_try_send(c);
7753 case CHAN_MAINSESSION:
7754 /* stdin need not receive an unthrottle
7755 * notification since it will be polled */
7758 x11_unthrottle(c->u.x11.xconn);
7761 /* agent sockets are request/response and need no
7762 * buffer management */
7765 pfd_unthrottle(c->u.pfd.pf);
7771 static int ssh_is_simple(Ssh ssh)
7774 * We use the 'simple' variant of the SSH protocol if we're asked
7775 * to, except not if we're also doing connection-sharing (either
7776 * tunnelling our packets over an upstream or expecting to be
7777 * tunnelled over ourselves), since then the assumption that we
7778 * have only one channel to worry about is not true after all.
7780 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7781 !ssh->bare_connection && !ssh->connshare);
7785 * Set up most of a new ssh_channel.
7787 static void ssh_channel_init(struct ssh_channel *c)
7790 c->localid = alloc_channel_id(ssh);
7792 c->pending_eof = FALSE;
7793 c->throttling_conn = FALSE;
7794 if (ssh->version == 2) {
7795 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7796 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7797 c->v.v2.chanreq_head = NULL;
7798 c->v.v2.throttle_state = UNTHROTTLED;
7799 bufchain_init(&c->v.v2.outbuffer);
7801 add234(ssh->channels, c);
7805 * Construct the common parts of a CHANNEL_OPEN.
7807 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7810 struct Packet *pktout;
7812 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7813 ssh2_pkt_addstring(pktout, type);
7814 ssh2_pkt_adduint32(pktout, c->localid);
7815 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7816 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7821 * CHANNEL_FAILURE doesn't come with any indication of what message
7822 * caused it, so we have to keep track of the outstanding
7823 * CHANNEL_REQUESTs ourselves.
7825 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7826 cchandler_fn_t handler, void *ctx)
7828 struct outstanding_channel_request *ocr =
7829 snew(struct outstanding_channel_request);
7831 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7832 ocr->handler = handler;
7835 if (!c->v.v2.chanreq_head)
7836 c->v.v2.chanreq_head = ocr;
7838 c->v.v2.chanreq_tail->next = ocr;
7839 c->v.v2.chanreq_tail = ocr;
7843 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7844 * NULL then a reply will be requested and the handler will be called
7845 * when it arrives. The returned packet is ready to have any
7846 * request-specific data added and be sent. Note that if a handler is
7847 * provided, it's essential that the request actually be sent.
7849 * The handler will usually be passed the response packet in pktin. If
7850 * pktin is NULL, this means that no reply will ever be forthcoming
7851 * (e.g. because the entire connection is being destroyed, or because
7852 * the server initiated channel closure before we saw the response)
7853 * and the handler should free any storage it's holding.
7855 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7857 cchandler_fn_t handler, void *ctx)
7859 struct Packet *pktout;
7861 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7862 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7863 ssh2_pkt_adduint32(pktout, c->remoteid);
7864 ssh2_pkt_addstring(pktout, type);
7865 ssh2_pkt_addbool(pktout, handler != NULL);
7866 if (handler != NULL)
7867 ssh2_queue_chanreq_handler(c, handler, ctx);
7871 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize)
7876 if (ssh->version == 1) {
7877 buflimit = SSH1_BUFFER_LIMIT;
7879 if (ssh_is_simple(ssh))
7882 buflimit = c->v.v2.locmaxwin;
7883 if (bufsize < buflimit)
7884 ssh2_set_window(c, buflimit - bufsize);
7886 if (c->throttling_conn && bufsize <= buflimit) {
7887 c->throttling_conn = 0;
7888 ssh_throttle_conn(ssh, -1);
7893 * Potentially enlarge the window on an SSH-2 channel.
7895 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7897 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7902 * Never send WINDOW_ADJUST for a channel that the remote side has
7903 * already sent EOF on; there's no point, since it won't be
7904 * sending any more data anyway. Ditto if _we've_ already sent
7907 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7911 * Also, never widen the window for an X11 channel when we're
7912 * still waiting to see its initial auth and may yet hand it off
7915 if (c->type == CHAN_X11 && c->u.x11.initial)
7919 * If the remote end has a habit of ignoring maxpkt, limit the
7920 * window so that it has no choice (assuming it doesn't ignore the
7923 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7924 newwin = OUR_V2_MAXPKT;
7927 * Only send a WINDOW_ADJUST if there's significantly more window
7928 * available than the other end thinks there is. This saves us
7929 * sending a WINDOW_ADJUST for every character in a shell session.
7931 * "Significant" is arbitrarily defined as half the window size.
7933 if (newwin / 2 >= c->v.v2.locwindow) {
7934 struct Packet *pktout;
7938 * In order to keep track of how much window the client
7939 * actually has available, we'd like it to acknowledge each
7940 * WINDOW_ADJUST. We can't do that directly, so we accompany
7941 * it with a CHANNEL_REQUEST that has to be acknowledged.
7943 * This is only necessary if we're opening the window wide.
7944 * If we're not, then throughput is being constrained by
7945 * something other than the maximum window size anyway.
7947 if (newwin == c->v.v2.locmaxwin &&
7948 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7949 up = snew(unsigned);
7950 *up = newwin - c->v.v2.locwindow;
7951 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7952 ssh2_handle_winadj_response, up);
7953 ssh2_pkt_send(ssh, pktout);
7955 if (c->v.v2.throttle_state != UNTHROTTLED)
7956 c->v.v2.throttle_state = UNTHROTTLING;
7958 /* Pretend the WINDOW_ADJUST was acked immediately. */
7959 c->v.v2.remlocwin = newwin;
7960 c->v.v2.throttle_state = THROTTLED;
7962 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7963 ssh2_pkt_adduint32(pktout, c->remoteid);
7964 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7965 ssh2_pkt_send(ssh, pktout);
7966 c->v.v2.locwindow = newwin;
7971 * Find the channel associated with a message. If there's no channel,
7972 * or it's not properly open, make a noise about it and return NULL.
7974 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7976 unsigned localid = ssh_pkt_getuint32(pktin);
7977 struct ssh_channel *c;
7979 c = find234(ssh->channels, &localid, ssh_channelfind);
7981 (c->type != CHAN_SHARING && c->halfopen &&
7982 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7983 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7984 char *buf = dupprintf("Received %s for %s channel %u",
7985 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7987 c ? "half-open" : "nonexistent", localid);
7988 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7995 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7996 struct Packet *pktin, void *ctx)
7998 unsigned *sizep = ctx;
8001 * Winadj responses should always be failures. However, at least
8002 * one server ("boks_sshd") is known to return SUCCESS for channel
8003 * requests it's never heard of, such as "winadj@putty". Raised
8004 * with foxt.com as bug 090916-090424, but for the sake of a quiet
8005 * life, we don't worry about what kind of response we got.
8008 c->v.v2.remlocwin += *sizep;
8011 * winadj messages are only sent when the window is fully open, so
8012 * if we get an ack of one, we know any pending unthrottle is
8015 if (c->v.v2.throttle_state == UNTHROTTLING)
8016 c->v.v2.throttle_state = UNTHROTTLED;
8019 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
8021 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
8022 struct outstanding_channel_request *ocr;
8025 if (c->type == CHAN_SHARING) {
8026 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8027 pktin->body, pktin->length);
8030 ocr = c->v.v2.chanreq_head;
8032 ssh2_msg_unexpected(ssh, pktin);
8035 ocr->handler(c, pktin, ocr->ctx);
8036 c->v.v2.chanreq_head = ocr->next;
8039 * We may now initiate channel-closing procedures, if that
8040 * CHANNEL_REQUEST was the last thing outstanding before we send
8043 ssh2_channel_check_close(c);
8046 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8048 struct ssh_channel *c;
8049 c = ssh2_channel_msg(ssh, pktin);
8052 if (c->type == CHAN_SHARING) {
8053 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8054 pktin->body, pktin->length);
8057 if (!(c->closes & CLOSES_SENT_EOF)) {
8058 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
8059 ssh2_try_send_and_unthrottle(ssh, c);
8063 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8067 struct ssh_channel *c;
8068 c = ssh2_channel_msg(ssh, pktin);
8071 if (c->type == CHAN_SHARING) {
8072 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8073 pktin->body, pktin->length);
8076 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
8077 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
8078 return; /* extended but not stderr */
8079 ssh_pkt_getstring(pktin, &data, &length);
8082 c->v.v2.locwindow -= length;
8083 c->v.v2.remlocwin -= length;
8084 bufsize = ssh_channel_data(c, pktin->type ==
8085 SSH2_MSG_CHANNEL_EXTENDED_DATA,
8088 * If it looks like the remote end hit the end of its window,
8089 * and we didn't want it to do that, think about using a
8092 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8093 c->v.v2.locmaxwin < 0x40000000)
8094 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8096 * If we are not buffering too much data,
8097 * enlarge the window again at the remote side.
8098 * If we are buffering too much, we may still
8099 * need to adjust the window if the server's
8102 if (bufsize < c->v.v2.locmaxwin)
8103 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
8105 * If we're either buffering way too much data, or if we're
8106 * buffering anything at all and we're in "simple" mode,
8107 * throttle the whole channel.
8109 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8110 && !c->throttling_conn) {
8111 c->throttling_conn = 1;
8112 ssh_throttle_conn(ssh, +1);
8117 static void ssh_check_termination(Ssh ssh)
8119 if (ssh->version == 2 &&
8120 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8121 (ssh->channels && count234(ssh->channels) == 0) &&
8122 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8124 * We used to send SSH_MSG_DISCONNECT here, because I'd
8125 * believed that _every_ conforming SSH-2 connection had to
8126 * end with a disconnect being sent by at least one side;
8127 * apparently I was wrong and it's perfectly OK to
8128 * unceremoniously slam the connection shut when you're done,
8129 * and indeed OpenSSH feels this is more polite than sending a
8130 * DISCONNECT. So now we don't.
8132 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8136 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8137 const char *peerinfo)
8140 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8143 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8146 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8148 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8149 ssh_check_termination(ssh);
8152 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8157 va_start(ap, logfmt);
8158 buf = dupvprintf(logfmt, ap);
8161 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8163 logeventf(ssh, "Connection sharing: %s", buf);
8167 static void ssh_channel_destroy(struct ssh_channel *c)
8172 case CHAN_MAINSESSION:
8173 ssh->mainchan = NULL;
8174 update_specials_menu(ssh->frontend);
8177 if (c->u.x11.xconn != NULL)
8178 x11_close(c->u.x11.xconn);
8179 logevent("Forwarded X11 connection terminated");
8182 sfree(c->u.a.message);
8185 if (c->u.pfd.pf != NULL)
8186 pfd_close(c->u.pfd.pf);
8187 logevent("Forwarded port closed");
8191 del234(ssh->channels, c);
8192 if (ssh->version == 2) {
8193 bufchain_clear(&c->v.v2.outbuffer);
8194 assert(c->v.v2.chanreq_head == NULL);
8199 * If that was the last channel left open, we might need to
8202 ssh_check_termination(ssh);
8205 static void ssh2_channel_check_close(struct ssh_channel *c)
8208 struct Packet *pktout;
8210 assert(ssh->version == 2);
8213 * If we've sent out our own CHANNEL_OPEN but not yet seen
8214 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8215 * it's too early to be sending close messages of any kind.
8220 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8221 c->type == CHAN_ZOMBIE) &&
8222 !c->v.v2.chanreq_head &&
8223 !(c->closes & CLOSES_SENT_CLOSE)) {
8225 * We have both sent and received EOF (or the channel is a
8226 * zombie), and we have no outstanding channel requests, which
8227 * means the channel is in final wind-up. But we haven't sent
8228 * CLOSE, so let's do so now.
8230 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8231 ssh2_pkt_adduint32(pktout, c->remoteid);
8232 ssh2_pkt_send(ssh, pktout);
8233 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8236 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8237 assert(c->v.v2.chanreq_head == NULL);
8239 * We have both sent and received CLOSE, which means we're
8240 * completely done with the channel.
8242 ssh_channel_destroy(c);
8246 static void ssh2_channel_got_eof(struct ssh_channel *c)
8248 if (c->closes & CLOSES_RCVD_EOF)
8249 return; /* already seen EOF */
8250 c->closes |= CLOSES_RCVD_EOF;
8252 if (c->type == CHAN_X11) {
8253 x11_send_eof(c->u.x11.xconn);
8254 } else if (c->type == CHAN_AGENT) {
8255 if (c->u.a.outstanding_requests == 0) {
8256 /* Manufacture an outgoing EOF in response to the incoming one. */
8257 sshfwd_write_eof(c);
8259 } else if (c->type == CHAN_SOCKDATA) {
8260 pfd_send_eof(c->u.pfd.pf);
8261 } else if (c->type == CHAN_MAINSESSION) {
8264 if (!ssh->sent_console_eof &&
8265 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8267 * Either from_backend_eof told us that the front end
8268 * wants us to close the outgoing side of the connection
8269 * as soon as we see EOF from the far end, or else we've
8270 * unilaterally decided to do that because we've allocated
8271 * a remote pty and hence EOF isn't a particularly
8272 * meaningful concept.
8274 sshfwd_write_eof(c);
8276 ssh->sent_console_eof = TRUE;
8279 ssh2_channel_check_close(c);
8282 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8284 struct ssh_channel *c;
8286 c = ssh2_channel_msg(ssh, pktin);
8289 if (c->type == CHAN_SHARING) {
8290 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8291 pktin->body, pktin->length);
8294 ssh2_channel_got_eof(c);
8297 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8299 struct ssh_channel *c;
8301 c = ssh2_channel_msg(ssh, pktin);
8304 if (c->type == CHAN_SHARING) {
8305 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8306 pktin->body, pktin->length);
8311 * When we receive CLOSE on a channel, we assume it comes with an
8312 * implied EOF if we haven't seen EOF yet.
8314 ssh2_channel_got_eof(c);
8316 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8318 * It also means we stop expecting to see replies to any
8319 * outstanding channel requests, so clean those up too.
8320 * (ssh_chanreq_init will enforce by assertion that we don't
8321 * subsequently put anything back on this list.)
8323 while (c->v.v2.chanreq_head) {
8324 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8325 ocr->handler(c, NULL, ocr->ctx);
8326 c->v.v2.chanreq_head = ocr->next;
8332 * And we also send an outgoing EOF, if we haven't already, on the
8333 * assumption that CLOSE is a pretty forceful announcement that
8334 * the remote side is doing away with the entire channel. (If it
8335 * had wanted to send us EOF and continue receiving data from us,
8336 * it would have just sent CHANNEL_EOF.)
8338 if (!(c->closes & CLOSES_SENT_EOF)) {
8340 * Make sure we don't read any more from whatever our local
8341 * data source is for this channel.
8344 case CHAN_MAINSESSION:
8345 ssh->send_ok = 0; /* stop trying to read from stdin */
8348 x11_override_throttle(c->u.x11.xconn, 1);
8351 pfd_override_throttle(c->u.pfd.pf, 1);
8356 * Abandon any buffered data we still wanted to send to this
8357 * channel. Receiving a CHANNEL_CLOSE is an indication that
8358 * the server really wants to get on and _destroy_ this
8359 * channel, and it isn't going to send us any further
8360 * WINDOW_ADJUSTs to permit us to send pending stuff.
8362 bufchain_clear(&c->v.v2.outbuffer);
8365 * Send outgoing EOF.
8367 sshfwd_write_eof(c);
8371 * Now process the actual close.
8373 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8374 c->closes |= CLOSES_RCVD_CLOSE;
8375 ssh2_channel_check_close(c);
8379 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8381 struct ssh_channel *c;
8383 c = ssh2_channel_msg(ssh, pktin);
8386 if (c->type == CHAN_SHARING) {
8387 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8388 pktin->body, pktin->length);
8391 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8392 c->remoteid = ssh_pkt_getuint32(pktin);
8393 c->halfopen = FALSE;
8394 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8395 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8397 if (c->type == CHAN_SOCKDATA_DORMANT) {
8398 c->type = CHAN_SOCKDATA;
8400 pfd_confirm(c->u.pfd.pf);
8401 } else if (c->type == CHAN_ZOMBIE) {
8403 * This case can occur if a local socket error occurred
8404 * between us sending out CHANNEL_OPEN and receiving
8405 * OPEN_CONFIRMATION. In this case, all we can do is
8406 * immediately initiate close proceedings now that we know the
8407 * server's id to put in the close message.
8409 ssh2_channel_check_close(c);
8412 * We never expect to receive OPEN_CONFIRMATION for any
8413 * *other* channel type (since only local-to-remote port
8414 * forwardings cause us to send CHANNEL_OPEN after the main
8415 * channel is live - all other auxiliary channel types are
8416 * initiated from the server end). It's safe to enforce this
8417 * by assertion rather than by ssh_disconnect, because the
8418 * real point is that we never constructed a half-open channel
8419 * structure in the first place with any type other than the
8422 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8426 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8429 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8431 static const char *const reasons[] = {
8432 "<unknown reason code>",
8433 "Administratively prohibited",
8435 "Unknown channel type",
8436 "Resource shortage",
8438 unsigned reason_code;
8439 char *reason_string;
8441 struct ssh_channel *c;
8443 c = ssh2_channel_msg(ssh, pktin);
8446 if (c->type == CHAN_SHARING) {
8447 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8448 pktin->body, pktin->length);
8451 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8453 if (c->type == CHAN_SOCKDATA_DORMANT) {
8454 reason_code = ssh_pkt_getuint32(pktin);
8455 if (reason_code >= lenof(reasons))
8456 reason_code = 0; /* ensure reasons[reason_code] in range */
8457 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8458 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8459 reasons[reason_code], reason_length,
8460 NULLTOEMPTY(reason_string));
8462 pfd_close(c->u.pfd.pf);
8463 } else if (c->type == CHAN_ZOMBIE) {
8465 * This case can occur if a local socket error occurred
8466 * between us sending out CHANNEL_OPEN and receiving
8467 * OPEN_FAILURE. In this case, we need do nothing except allow
8468 * the code below to throw the half-open channel away.
8472 * We never expect to receive OPEN_FAILURE for any *other*
8473 * channel type (since only local-to-remote port forwardings
8474 * cause us to send CHANNEL_OPEN after the main channel is
8475 * live - all other auxiliary channel types are initiated from
8476 * the server end). It's safe to enforce this by assertion
8477 * rather than by ssh_disconnect, because the real point is
8478 * that we never constructed a half-open channel structure in
8479 * the first place with any type other than the above.
8481 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8484 del234(ssh->channels, c);
8488 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8491 int typelen, want_reply;
8492 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8493 struct ssh_channel *c;
8494 struct Packet *pktout;
8496 c = ssh2_channel_msg(ssh, pktin);
8499 if (c->type == CHAN_SHARING) {
8500 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8501 pktin->body, pktin->length);
8504 ssh_pkt_getstring(pktin, &type, &typelen);
8505 want_reply = ssh2_pkt_getbool(pktin);
8507 if (c->closes & CLOSES_SENT_CLOSE) {
8509 * We don't reply to channel requests after we've sent
8510 * CHANNEL_CLOSE for the channel, because our reply might
8511 * cross in the network with the other side's CHANNEL_CLOSE
8512 * and arrive after they have wound the channel up completely.
8518 * Having got the channel number, we now look at
8519 * the request type string to see if it's something
8522 if (c == ssh->mainchan) {
8524 * We recognise "exit-status" and "exit-signal" on
8525 * the primary channel.
8527 if (typelen == 11 &&
8528 !memcmp(type, "exit-status", 11)) {
8530 ssh->exitcode = ssh_pkt_getuint32(pktin);
8531 logeventf(ssh, "Server sent command exit status %d",
8533 reply = SSH2_MSG_CHANNEL_SUCCESS;
8535 } else if (typelen == 11 &&
8536 !memcmp(type, "exit-signal", 11)) {
8538 int is_plausible = TRUE, is_int = FALSE;
8539 char *fmt_sig = NULL, *fmt_msg = NULL;
8541 int msglen = 0, core = FALSE;
8542 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8543 * provide an `int' for the signal, despite its
8544 * having been a `string' in the drafts of RFC 4254 since at
8545 * least 2001. (Fixed in session.c 1.147.) Try to
8546 * infer which we can safely parse it as. */
8548 unsigned char *p = pktin->body +
8550 long len = pktin->length - pktin->savedpos;
8551 unsigned long num = GET_32BIT(p); /* what is it? */
8552 /* If it's 0, it hardly matters; assume string */
8556 int maybe_int = FALSE, maybe_str = FALSE;
8557 #define CHECK_HYPOTHESIS(offset, result) \
8560 int q = toint(offset); \
8561 if (q >= 0 && q+4 <= len) { \
8562 q = toint(q + 4 + GET_32BIT(p+q)); \
8563 if (q >= 0 && q+4 <= len && \
8564 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8569 CHECK_HYPOTHESIS(4+1, maybe_int);
8570 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8571 #undef CHECK_HYPOTHESIS
8572 if (maybe_int && !maybe_str)
8574 else if (!maybe_int && maybe_str)
8577 /* Crikey. Either or neither. Panic. */
8578 is_plausible = FALSE;
8581 ssh->exitcode = 128; /* means `unknown signal' */
8584 /* Old non-standard OpenSSH. */
8585 int signum = ssh_pkt_getuint32(pktin);
8586 fmt_sig = dupprintf(" %d", signum);
8587 ssh->exitcode = 128 + signum;
8589 /* As per RFC 4254. */
8592 ssh_pkt_getstring(pktin, &sig, &siglen);
8593 /* Signal name isn't supposed to be blank, but
8594 * let's cope gracefully if it is. */
8596 fmt_sig = dupprintf(" \"%.*s\"",
8601 * Really hideous method of translating the
8602 * signal description back into a locally
8603 * meaningful number.
8608 #define TRANSLATE_SIGNAL(s) \
8609 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8610 ssh->exitcode = 128 + SIG ## s
8612 TRANSLATE_SIGNAL(ABRT);
8615 TRANSLATE_SIGNAL(ALRM);
8618 TRANSLATE_SIGNAL(FPE);
8621 TRANSLATE_SIGNAL(HUP);
8624 TRANSLATE_SIGNAL(ILL);
8627 TRANSLATE_SIGNAL(INT);
8630 TRANSLATE_SIGNAL(KILL);
8633 TRANSLATE_SIGNAL(PIPE);
8636 TRANSLATE_SIGNAL(QUIT);
8639 TRANSLATE_SIGNAL(SEGV);
8642 TRANSLATE_SIGNAL(TERM);
8645 TRANSLATE_SIGNAL(USR1);
8648 TRANSLATE_SIGNAL(USR2);
8650 #undef TRANSLATE_SIGNAL
8652 ssh->exitcode = 128;
8654 core = ssh2_pkt_getbool(pktin);
8655 ssh_pkt_getstring(pktin, &msg, &msglen);
8657 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8659 /* ignore lang tag */
8660 } /* else don't attempt to parse */
8661 logeventf(ssh, "Server exited on signal%s%s%s",
8662 fmt_sig ? fmt_sig : "",
8663 core ? " (core dumped)" : "",
8664 fmt_msg ? fmt_msg : "");
8667 reply = SSH2_MSG_CHANNEL_SUCCESS;
8672 * This is a channel request we don't know
8673 * about, so we now either ignore the request
8674 * or respond with CHANNEL_FAILURE, depending
8677 reply = SSH2_MSG_CHANNEL_FAILURE;
8680 pktout = ssh2_pkt_init(reply);
8681 ssh2_pkt_adduint32(pktout, c->remoteid);
8682 ssh2_pkt_send(ssh, pktout);
8686 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8689 int typelen, want_reply;
8690 struct Packet *pktout;
8692 ssh_pkt_getstring(pktin, &type, &typelen);
8693 want_reply = ssh2_pkt_getbool(pktin);
8696 * We currently don't support any global requests
8697 * at all, so we either ignore the request or
8698 * respond with REQUEST_FAILURE, depending on
8702 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8703 ssh2_pkt_send(ssh, pktout);
8707 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8711 struct X11FakeAuth *auth;
8714 * Make up a new set of fake X11 auth data, and add it to the tree
8715 * of currently valid ones with an indication of the sharing
8716 * context that it's relevant to.
8718 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8719 auth->share_cs = share_cs;
8720 auth->share_chan = share_chan;
8725 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8727 del234(ssh->x11authtree, auth);
8728 x11_free_fake_auth(auth);
8731 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8738 const char *error = NULL;
8739 struct ssh_channel *c;
8740 unsigned remid, winsize, pktsize;
8741 unsigned our_winsize_override = 0;
8742 struct Packet *pktout;
8744 ssh_pkt_getstring(pktin, &type, &typelen);
8745 c = snew(struct ssh_channel);
8748 remid = ssh_pkt_getuint32(pktin);
8749 winsize = ssh_pkt_getuint32(pktin);
8750 pktsize = ssh_pkt_getuint32(pktin);
8752 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8755 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8756 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8757 peerport = ssh_pkt_getuint32(pktin);
8759 logeventf(ssh, "Received X11 connect request from %s:%d",
8762 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8763 error = "X11 forwarding is not enabled";
8765 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8768 c->u.x11.initial = TRUE;
8771 * If we are a connection-sharing upstream, then we should
8772 * initially present a very small window, adequate to take
8773 * the X11 initial authorisation packet but not much more.
8774 * Downstream will then present us a larger window (by
8775 * fiat of the connection-sharing protocol) and we can
8776 * guarantee to send a positive-valued WINDOW_ADJUST.
8779 our_winsize_override = 128;
8781 logevent("Opened X11 forward channel");
8785 } else if (typelen == 15 &&
8786 !memcmp(type, "forwarded-tcpip", 15)) {
8787 struct ssh_rportfwd pf, *realpf;
8790 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8791 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8792 pf.sport = ssh_pkt_getuint32(pktin);
8793 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8794 peerport = ssh_pkt_getuint32(pktin);
8795 realpf = find234(ssh->rportfwds, &pf, NULL);
8796 logeventf(ssh, "Received remote port %s:%d open request "
8797 "from %.*s:%d", pf.shost, pf.sport,
8798 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8801 if (realpf == NULL) {
8802 error = "Remote port is not recognised";
8806 if (realpf->share_ctx) {
8808 * This port forwarding is on behalf of a
8809 * connection-sharing downstream, so abandon our own
8810 * channel-open procedure and just pass the message on
8813 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8814 pktin->body, pktin->length);
8819 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8820 c, ssh->conf, realpf->pfrec->addressfamily);
8821 logeventf(ssh, "Attempting to forward remote port to "
8822 "%s:%d", realpf->dhost, realpf->dport);
8824 logeventf(ssh, "Port open failed: %s", err);
8826 error = "Port open failed";
8828 logevent("Forwarded port opened successfully");
8829 c->type = CHAN_SOCKDATA;
8832 } else if (typelen == 22 &&
8833 !memcmp(type, "auth-agent@openssh.com", 22)) {
8834 if (!ssh->agentfwd_enabled)
8835 error = "Agent forwarding is not enabled";
8837 c->type = CHAN_AGENT; /* identify channel type */
8838 c->u.a.lensofar = 0;
8839 c->u.a.message = NULL;
8840 c->u.a.outstanding_requests = 0;
8843 error = "Unsupported channel type requested";
8846 c->remoteid = remid;
8847 c->halfopen = FALSE;
8849 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8850 ssh2_pkt_adduint32(pktout, c->remoteid);
8851 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8852 ssh2_pkt_addstring(pktout, error);
8853 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8854 ssh2_pkt_send(ssh, pktout);
8855 logeventf(ssh, "Rejected channel open: %s", error);
8858 ssh_channel_init(c);
8859 c->v.v2.remwindow = winsize;
8860 c->v.v2.remmaxpkt = pktsize;
8861 if (our_winsize_override) {
8862 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8863 our_winsize_override;
8865 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8866 ssh2_pkt_adduint32(pktout, c->remoteid);
8867 ssh2_pkt_adduint32(pktout, c->localid);
8868 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8869 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8870 ssh2_pkt_send(ssh, pktout);
8874 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8875 void *share_cs, void *share_chan,
8876 const char *peer_addr, int peer_port,
8877 int endian, int protomajor, int protominor,
8878 const void *initial_data, int initial_len)
8881 * This function is called when we've just discovered that an X
8882 * forwarding channel on which we'd been handling the initial auth
8883 * ourselves turns out to be destined for a connection-sharing
8884 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8885 * that we completely stop tracking windows and buffering data and
8886 * just pass more or less unmodified SSH messages back and forth.
8888 c->type = CHAN_SHARING;
8889 c->u.sharing.ctx = share_cs;
8890 share_setup_x11_channel(share_cs, share_chan,
8891 c->localid, c->remoteid, c->v.v2.remwindow,
8892 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8893 peer_addr, peer_port, endian,
8894 protomajor, protominor,
8895 initial_data, initial_len);
8898 void sshfwd_x11_is_local(struct ssh_channel *c)
8901 * This function is called when we've just discovered that an X
8902 * forwarding channel is _not_ destined for a connection-sharing
8903 * downstream but we're going to handle it ourselves. We stop
8904 * presenting a cautiously small window and go into ordinary data
8907 c->u.x11.initial = FALSE;
8908 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8912 * Buffer banner messages for later display at some convenient point,
8913 * if we're going to display them.
8915 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8917 /* Arbitrary limit to prevent unbounded inflation of buffer */
8918 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8919 bufchain_size(&ssh->banner) <= 131072) {
8920 char *banner = NULL;
8922 ssh_pkt_getstring(pktin, &banner, &size);
8924 bufchain_add(&ssh->banner, banner, size);
8928 /* Helper function to deal with sending tty modes for "pty-req" */
8929 static void ssh2_send_ttymode(void *data,
8930 const struct ssh_ttymode *mode, char *val)
8932 struct Packet *pktout = (struct Packet *)data;
8933 unsigned int arg = 0;
8935 switch (mode->type) {
8937 arg = ssh_tty_parse_specchar(val);
8940 arg = ssh_tty_parse_boolean(val);
8943 ssh2_pkt_addbyte(pktout, mode->opcode);
8944 ssh2_pkt_adduint32(pktout, arg);
8947 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8950 struct ssh2_setup_x11_state {
8954 struct Packet *pktout;
8955 crStateP(ssh2_setup_x11_state, ctx);
8959 logevent("Requesting X11 forwarding");
8960 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8962 ssh2_pkt_addbool(pktout, 0); /* many connections */
8963 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8964 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8965 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8966 ssh2_pkt_send(ssh, pktout);
8968 /* Wait to be called back with either a response packet, or NULL
8969 * meaning clean up and free our data */
8973 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8974 logevent("X11 forwarding enabled");
8975 ssh->X11_fwd_enabled = TRUE;
8977 logevent("X11 forwarding refused");
8983 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8986 struct ssh2_setup_agent_state {
8990 struct Packet *pktout;
8991 crStateP(ssh2_setup_agent_state, ctx);
8995 logevent("Requesting OpenSSH-style agent forwarding");
8996 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8997 ssh2_setup_agent, s);
8998 ssh2_pkt_send(ssh, pktout);
9000 /* Wait to be called back with either a response packet, or NULL
9001 * meaning clean up and free our data */
9005 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9006 logevent("Agent forwarding enabled");
9007 ssh->agentfwd_enabled = TRUE;
9009 logevent("Agent forwarding refused");
9015 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
9018 struct ssh2_setup_pty_state {
9022 struct Packet *pktout;
9023 crStateP(ssh2_setup_pty_state, ctx);
9027 /* Unpick the terminal-speed string. */
9028 /* XXX perhaps we should allow no speeds to be sent. */
9029 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9030 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9031 /* Build the pty request. */
9032 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9034 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9035 ssh2_pkt_adduint32(pktout, ssh->term_width);
9036 ssh2_pkt_adduint32(pktout, ssh->term_height);
9037 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9038 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9039 ssh2_pkt_addstring_start(pktout);
9040 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9041 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9042 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9043 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9044 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9045 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9046 ssh2_pkt_send(ssh, pktout);
9047 ssh->state = SSH_STATE_INTERMED;
9049 /* Wait to be called back with either a response packet, or NULL
9050 * meaning clean up and free our data */
9054 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9055 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9056 ssh->ospeed, ssh->ispeed);
9057 ssh->got_pty = TRUE;
9059 c_write_str(ssh, "Server refused to allocate pty\r\n");
9060 ssh->editing = ssh->echoing = 1;
9067 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9070 struct ssh2_setup_env_state {
9072 int num_env, env_left, env_ok;
9075 struct Packet *pktout;
9076 crStateP(ssh2_setup_env_state, ctx);
9081 * Send environment variables.
9083 * Simplest thing here is to send all the requests at once, and
9084 * then wait for a whole bunch of successes or failures.
9090 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9092 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9093 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9094 ssh2_pkt_addstring(pktout, key);
9095 ssh2_pkt_addstring(pktout, val);
9096 ssh2_pkt_send(ssh, pktout);
9101 logeventf(ssh, "Sent %d environment variables", s->num_env);
9106 s->env_left = s->num_env;
9108 while (s->env_left > 0) {
9109 /* Wait to be called back with either a response packet,
9110 * or NULL meaning clean up and free our data */
9112 if (!pktin) goto out;
9113 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9118 if (s->env_ok == s->num_env) {
9119 logevent("All environment variables successfully set");
9120 } else if (s->env_ok == 0) {
9121 logevent("All environment variables refused");
9122 c_write_str(ssh, "Server refused to set environment variables\r\n");
9124 logeventf(ssh, "%d environment variables refused",
9125 s->num_env - s->env_ok);
9126 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9134 * Handle the SSH-2 userauth and connection layers.
9136 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9138 do_ssh2_authconn(ssh, NULL, 0, pktin);
9141 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9145 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9148 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9149 struct Packet *pktin)
9151 struct do_ssh2_authconn_state {
9155 AUTH_TYPE_PUBLICKEY,
9156 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9157 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9159 AUTH_TYPE_GSSAPI, /* always QUIET */
9160 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9161 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9163 int done_service_req;
9164 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9165 int tried_pubkey_config, done_agent;
9170 int kbd_inter_refused;
9171 int we_are_in, userauth_success;
9172 prompts_t *cur_prompt;
9177 void *publickey_blob;
9178 int publickey_bloblen;
9179 int privatekey_available, privatekey_encrypted;
9180 char *publickey_algorithm;
9181 char *publickey_comment;
9182 unsigned char agent_request[5], *agent_response, *agentp;
9183 int agent_responselen;
9184 unsigned char *pkblob_in_agent;
9186 char *pkblob, *alg, *commentp;
9187 int pklen, alglen, commentlen;
9188 int siglen, retlen, len;
9189 char *q, *agentreq, *ret;
9190 struct Packet *pktout;
9193 struct ssh_gss_library *gsslib;
9194 Ssh_gss_ctx gss_ctx;
9195 Ssh_gss_buf gss_buf;
9196 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9197 Ssh_gss_name gss_srv_name;
9198 Ssh_gss_stat gss_stat;
9201 crState(do_ssh2_authconn_state);
9205 /* Register as a handler for all the messages this coroutine handles. */
9206 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9207 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9208 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9209 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9210 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9211 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9212 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9213 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9214 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9215 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9216 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9217 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9218 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9219 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9220 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9221 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9222 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9223 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9224 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9225 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9227 s->done_service_req = FALSE;
9228 s->we_are_in = s->userauth_success = FALSE;
9229 s->agent_response = NULL;
9231 s->tried_gssapi = FALSE;
9234 if (!ssh->bare_connection) {
9235 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9237 * Request userauth protocol, and await a response to it.
9239 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9240 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9241 ssh2_pkt_send(ssh, s->pktout);
9242 crWaitUntilV(pktin);
9243 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9244 s->done_service_req = TRUE;
9246 if (!s->done_service_req) {
9248 * Request connection protocol directly, without authentication.
9250 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9251 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9252 ssh2_pkt_send(ssh, s->pktout);
9253 crWaitUntilV(pktin);
9254 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9255 s->we_are_in = TRUE; /* no auth required */
9257 bombout(("Server refused service request"));
9262 s->we_are_in = TRUE;
9265 /* Arrange to be able to deal with any BANNERs that come in.
9266 * (We do this now as packets may come in during the next bit.) */
9267 bufchain_init(&ssh->banner);
9268 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9269 ssh2_msg_userauth_banner;
9272 * Misc one-time setup for authentication.
9274 s->publickey_blob = NULL;
9275 if (!s->we_are_in) {
9278 * Load the public half of any configured public key file
9281 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9282 if (!filename_is_null(s->keyfile)) {
9284 logeventf(ssh, "Reading key file \"%.150s\"",
9285 filename_to_str(s->keyfile));
9286 keytype = key_type(s->keyfile);
9287 if (keytype == SSH_KEYTYPE_SSH2 ||
9288 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9289 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9292 ssh2_userkey_loadpub(s->keyfile,
9293 &s->publickey_algorithm,
9294 &s->publickey_bloblen,
9295 &s->publickey_comment, &error);
9296 if (s->publickey_blob) {
9297 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9298 if (!s->privatekey_available)
9299 logeventf(ssh, "Key file contains public key only");
9300 s->privatekey_encrypted =
9301 ssh2_userkey_encrypted(s->keyfile, NULL);
9304 logeventf(ssh, "Unable to load key (%s)",
9306 msgbuf = dupprintf("Unable to load key file "
9307 "\"%.150s\" (%s)\r\n",
9308 filename_to_str(s->keyfile),
9310 c_write_str(ssh, msgbuf);
9315 logeventf(ssh, "Unable to use this key file (%s)",
9316 key_type_to_str(keytype));
9317 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9319 filename_to_str(s->keyfile),
9320 key_type_to_str(keytype));
9321 c_write_str(ssh, msgbuf);
9323 s->publickey_blob = NULL;
9328 * Find out about any keys Pageant has (but if there's a
9329 * public key configured, filter out all others).
9332 s->agent_response = NULL;
9333 s->pkblob_in_agent = NULL;
9334 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9338 logevent("Pageant is running. Requesting keys.");
9340 /* Request the keys held by the agent. */
9341 PUT_32BIT(s->agent_request, 1);
9342 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9343 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9344 ssh_agent_callback, ssh)) {
9348 bombout(("Unexpected data from server while"
9349 " waiting for agent response"));
9352 } while (pktin || inlen > 0);
9353 r = ssh->agent_response;
9354 s->agent_responselen = ssh->agent_response_len;
9356 s->agent_response = (unsigned char *) r;
9357 if (s->agent_response && s->agent_responselen >= 5 &&
9358 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9361 p = s->agent_response + 5;
9362 s->nkeys = toint(GET_32BIT(p));
9365 * Vet the Pageant response to ensure that the key
9366 * count and blob lengths make sense.
9369 logeventf(ssh, "Pageant response contained a negative"
9370 " key count %d", s->nkeys);
9372 goto done_agent_query;
9374 unsigned char *q = p + 4;
9375 int lenleft = s->agent_responselen - 5 - 4;
9377 for (keyi = 0; keyi < s->nkeys; keyi++) {
9378 int bloblen, commentlen;
9380 logeventf(ssh, "Pageant response was truncated");
9382 goto done_agent_query;
9384 bloblen = toint(GET_32BIT(q));
9385 if (bloblen < 0 || bloblen > lenleft) {
9386 logeventf(ssh, "Pageant response was truncated");
9388 goto done_agent_query;
9390 lenleft -= 4 + bloblen;
9392 commentlen = toint(GET_32BIT(q));
9393 if (commentlen < 0 || commentlen > lenleft) {
9394 logeventf(ssh, "Pageant response was truncated");
9396 goto done_agent_query;
9398 lenleft -= 4 + commentlen;
9399 q += 4 + commentlen;
9404 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9405 if (s->publickey_blob) {
9406 /* See if configured key is in agent. */
9407 for (keyi = 0; keyi < s->nkeys; keyi++) {
9408 s->pklen = toint(GET_32BIT(p));
9409 if (s->pklen == s->publickey_bloblen &&
9410 !memcmp(p+4, s->publickey_blob,
9411 s->publickey_bloblen)) {
9412 logeventf(ssh, "Pageant key #%d matches "
9413 "configured key file", keyi);
9415 s->pkblob_in_agent = p;
9419 p += toint(GET_32BIT(p)) + 4; /* comment */
9421 if (!s->pkblob_in_agent) {
9422 logevent("Configured key file not in Pageant");
9427 logevent("Failed to get reply from Pageant");
9435 * We repeat this whole loop, including the username prompt,
9436 * until we manage a successful authentication. If the user
9437 * types the wrong _password_, they can be sent back to the
9438 * beginning to try another username, if this is configured on.
9439 * (If they specify a username in the config, they are never
9440 * asked, even if they do give a wrong password.)
9442 * I think this best serves the needs of
9444 * - the people who have no configuration, no keys, and just
9445 * want to try repeated (username,password) pairs until they
9446 * type both correctly
9448 * - people who have keys and configuration but occasionally
9449 * need to fall back to passwords
9451 * - people with a key held in Pageant, who might not have
9452 * logged in to a particular machine before; so they want to
9453 * type a username, and then _either_ their key will be
9454 * accepted, _or_ they will type a password. If they mistype
9455 * the username they will want to be able to get back and
9458 s->got_username = FALSE;
9459 while (!s->we_are_in) {
9463 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9465 * We got a username last time round this loop, and
9466 * with change_username turned off we don't try to get
9469 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9470 int ret; /* need not be kept over crReturn */
9471 s->cur_prompt = new_prompts(ssh->frontend);
9472 s->cur_prompt->to_server = TRUE;
9473 s->cur_prompt->name = dupstr("SSH login name");
9474 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9475 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9478 crWaitUntilV(!pktin);
9479 ret = get_userpass_input(s->cur_prompt, in, inlen);
9484 * get_userpass_input() failed to get a username.
9487 free_prompts(s->cur_prompt);
9488 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9491 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9492 free_prompts(s->cur_prompt);
9495 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9496 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9497 c_write_str(ssh, stuff);
9501 s->got_username = TRUE;
9504 * Send an authentication request using method "none": (a)
9505 * just in case it succeeds, and (b) so that we know what
9506 * authentication methods we can usefully try next.
9508 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9510 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9511 ssh2_pkt_addstring(s->pktout, ssh->username);
9512 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9513 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9514 ssh2_pkt_send(ssh, s->pktout);
9515 s->type = AUTH_TYPE_NONE;
9517 s->we_are_in = FALSE;
9519 s->tried_pubkey_config = FALSE;
9520 s->kbd_inter_refused = FALSE;
9522 /* Reset agent request state. */
9523 s->done_agent = FALSE;
9524 if (s->agent_response) {
9525 if (s->pkblob_in_agent) {
9526 s->agentp = s->pkblob_in_agent;
9528 s->agentp = s->agent_response + 5 + 4;
9534 char *methods = NULL;
9538 * Wait for the result of the last authentication request.
9541 crWaitUntilV(pktin);
9543 * Now is a convenient point to spew any banner material
9544 * that we've accumulated. (This should ensure that when
9545 * we exit the auth loop, we haven't any left to deal
9549 int size = bufchain_size(&ssh->banner);
9551 * Don't show the banner if we're operating in
9552 * non-verbose non-interactive mode. (It's probably
9553 * a script, which means nobody will read the
9554 * banner _anyway_, and moreover the printing of
9555 * the banner will screw up processing on the
9556 * output of (say) plink.)
9558 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9559 char *banner = snewn(size, char);
9560 bufchain_fetch(&ssh->banner, banner, size);
9561 c_write_untrusted(ssh, banner, size);
9564 bufchain_clear(&ssh->banner);
9566 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9567 logevent("Access granted");
9568 s->we_are_in = s->userauth_success = TRUE;
9572 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9573 bombout(("Strange packet received during authentication: "
9574 "type %d", pktin->type));
9581 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9582 * we can look at the string in it and know what we can
9583 * helpfully try next.
9585 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9586 ssh_pkt_getstring(pktin, &methods, &methlen);
9587 if (!ssh2_pkt_getbool(pktin)) {
9589 * We have received an unequivocal Access
9590 * Denied. This can translate to a variety of
9591 * messages, or no message at all.
9593 * For forms of authentication which are attempted
9594 * implicitly, by which I mean without printing
9595 * anything in the window indicating that we're
9596 * trying them, we should never print 'Access
9599 * If we do print a message saying that we're
9600 * attempting some kind of authentication, it's OK
9601 * to print a followup message saying it failed -
9602 * but the message may sometimes be more specific
9603 * than simply 'Access denied'.
9605 * Additionally, if we'd just tried password
9606 * authentication, we should break out of this
9607 * whole loop so as to go back to the username
9608 * prompt (iff we're configured to allow
9609 * username change attempts).
9611 if (s->type == AUTH_TYPE_NONE) {
9613 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9614 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9615 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9616 c_write_str(ssh, "Server refused our key\r\n");
9617 logevent("Server refused our key");
9618 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9619 /* This _shouldn't_ happen except by a
9620 * protocol bug causing client and server to
9621 * disagree on what is a correct signature. */
9622 c_write_str(ssh, "Server refused public-key signature"
9623 " despite accepting key!\r\n");
9624 logevent("Server refused public-key signature"
9625 " despite accepting key!");
9626 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9627 /* quiet, so no c_write */
9628 logevent("Server refused keyboard-interactive authentication");
9629 } else if (s->type==AUTH_TYPE_GSSAPI) {
9630 /* always quiet, so no c_write */
9631 /* also, the code down in the GSSAPI block has
9632 * already logged this in the Event Log */
9633 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9634 logevent("Keyboard-interactive authentication failed");
9635 c_write_str(ssh, "Access denied\r\n");
9637 assert(s->type == AUTH_TYPE_PASSWORD);
9638 logevent("Password authentication failed");
9639 c_write_str(ssh, "Access denied\r\n");
9641 if (conf_get_int(ssh->conf, CONF_change_username)) {
9642 /* XXX perhaps we should allow
9643 * keyboard-interactive to do this too? */
9644 s->we_are_in = FALSE;
9649 c_write_str(ssh, "Further authentication required\r\n");
9650 logevent("Further authentication required");
9654 in_commasep_string("publickey", methods, methlen);
9656 in_commasep_string("password", methods, methlen);
9657 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9658 in_commasep_string("keyboard-interactive", methods, methlen);
9660 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9661 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9662 /* Try loading the GSS libraries and see if we
9665 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9666 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9668 /* No point in even bothering to try to load the
9669 * GSS libraries, if the user configuration and
9670 * server aren't both prepared to attempt GSSAPI
9671 * auth in the first place. */
9672 s->can_gssapi = FALSE;
9677 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9679 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9682 * Attempt public-key authentication using a key from Pageant.
9685 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9687 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9689 /* Unpack key from agent response */
9690 s->pklen = toint(GET_32BIT(s->agentp));
9692 s->pkblob = (char *)s->agentp;
9693 s->agentp += s->pklen;
9694 s->alglen = toint(GET_32BIT(s->pkblob));
9695 s->alg = s->pkblob + 4;
9696 s->commentlen = toint(GET_32BIT(s->agentp));
9698 s->commentp = (char *)s->agentp;
9699 s->agentp += s->commentlen;
9700 /* s->agentp now points at next key, if any */
9702 /* See if server will accept it */
9703 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9704 ssh2_pkt_addstring(s->pktout, ssh->username);
9705 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9706 /* service requested */
9707 ssh2_pkt_addstring(s->pktout, "publickey");
9709 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9710 ssh2_pkt_addstring_start(s->pktout);
9711 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9712 ssh2_pkt_addstring_start(s->pktout);
9713 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9714 ssh2_pkt_send(ssh, s->pktout);
9715 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9717 crWaitUntilV(pktin);
9718 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9720 /* Offer of key refused. */
9727 if (flags & FLAG_VERBOSE) {
9728 c_write_str(ssh, "Authenticating with "
9730 c_write(ssh, s->commentp, s->commentlen);
9731 c_write_str(ssh, "\" from agent\r\n");
9735 * Server is willing to accept the key.
9736 * Construct a SIGN_REQUEST.
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, TRUE); /* 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);
9750 /* Ask agent for signature. */
9751 s->siglen = s->pktout->length - 5 + 4 +
9752 ssh->v2_session_id_len;
9753 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9755 s->len = 1; /* message type */
9756 s->len += 4 + s->pklen; /* key blob */
9757 s->len += 4 + s->siglen; /* data to sign */
9758 s->len += 4; /* flags */
9759 s->agentreq = snewn(4 + s->len, char);
9760 PUT_32BIT(s->agentreq, s->len);
9761 s->q = s->agentreq + 4;
9762 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9763 PUT_32BIT(s->q, s->pklen);
9765 memcpy(s->q, s->pkblob, s->pklen);
9767 PUT_32BIT(s->q, s->siglen);
9769 /* Now the data to be signed... */
9770 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9771 PUT_32BIT(s->q, ssh->v2_session_id_len);
9774 memcpy(s->q, ssh->v2_session_id,
9775 ssh->v2_session_id_len);
9776 s->q += ssh->v2_session_id_len;
9777 memcpy(s->q, s->pktout->data + 5,
9778 s->pktout->length - 5);
9779 s->q += s->pktout->length - 5;
9780 /* And finally the (zero) flags word. */
9782 if (!agent_query(s->agentreq, s->len + 4,
9784 ssh_agent_callback, ssh)) {
9788 bombout(("Unexpected data from server"
9789 " while waiting for agent"
9793 } while (pktin || inlen > 0);
9794 vret = ssh->agent_response;
9795 s->retlen = ssh->agent_response_len;
9800 if (s->retlen >= 9 &&
9801 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9802 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9803 logevent("Sending Pageant's response");
9804 ssh2_add_sigblob(ssh, s->pktout,
9805 s->pkblob, s->pklen,
9807 GET_32BIT(s->ret + 5));
9808 ssh2_pkt_send(ssh, s->pktout);
9809 s->type = AUTH_TYPE_PUBLICKEY;
9811 /* FIXME: less drastic response */
9812 bombout(("Pageant failed to answer challenge"));
9818 /* Do we have any keys left to try? */
9819 if (s->pkblob_in_agent) {
9820 s->done_agent = TRUE;
9821 s->tried_pubkey_config = TRUE;
9824 if (s->keyi >= s->nkeys)
9825 s->done_agent = TRUE;
9828 } else if (s->can_pubkey && s->publickey_blob &&
9829 s->privatekey_available && !s->tried_pubkey_config) {
9831 struct ssh2_userkey *key; /* not live over crReturn */
9832 char *passphrase; /* not live over crReturn */
9834 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9836 s->tried_pubkey_config = TRUE;
9839 * Try the public key supplied in the configuration.
9841 * First, offer the public blob to see if the server is
9842 * willing to accept it.
9844 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9845 ssh2_pkt_addstring(s->pktout, ssh->username);
9846 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9847 /* service requested */
9848 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9849 ssh2_pkt_addbool(s->pktout, FALSE);
9850 /* no signature included */
9851 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9852 ssh2_pkt_addstring_start(s->pktout);
9853 ssh2_pkt_addstring_data(s->pktout,
9854 (char *)s->publickey_blob,
9855 s->publickey_bloblen);
9856 ssh2_pkt_send(ssh, s->pktout);
9857 logevent("Offered public key");
9859 crWaitUntilV(pktin);
9860 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9861 /* Key refused. Give up. */
9862 s->gotit = TRUE; /* reconsider message next loop */
9863 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9864 continue; /* process this new message */
9866 logevent("Offer of public key accepted");
9869 * Actually attempt a serious authentication using
9872 if (flags & FLAG_VERBOSE) {
9873 c_write_str(ssh, "Authenticating with public key \"");
9874 c_write_str(ssh, s->publickey_comment);
9875 c_write_str(ssh, "\"\r\n");
9879 const char *error; /* not live over crReturn */
9880 if (s->privatekey_encrypted) {
9882 * Get a passphrase from the user.
9884 int ret; /* need not be kept over crReturn */
9885 s->cur_prompt = new_prompts(ssh->frontend);
9886 s->cur_prompt->to_server = FALSE;
9887 s->cur_prompt->name = dupstr("SSH key passphrase");
9888 add_prompt(s->cur_prompt,
9889 dupprintf("Passphrase for key \"%.100s\": ",
9890 s->publickey_comment),
9892 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9895 crWaitUntilV(!pktin);
9896 ret = get_userpass_input(s->cur_prompt,
9901 /* Failed to get a passphrase. Terminate. */
9902 free_prompts(s->cur_prompt);
9903 ssh_disconnect(ssh, NULL,
9904 "Unable to authenticate",
9905 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9910 dupstr(s->cur_prompt->prompts[0]->result);
9911 free_prompts(s->cur_prompt);
9913 passphrase = NULL; /* no passphrase needed */
9917 * Try decrypting the key.
9919 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9920 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9922 /* burn the evidence */
9923 smemclr(passphrase, strlen(passphrase));
9926 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9928 (key == SSH2_WRONG_PASSPHRASE)) {
9929 c_write_str(ssh, "Wrong passphrase\r\n");
9931 /* and loop again */
9933 c_write_str(ssh, "Unable to load private key (");
9934 c_write_str(ssh, error);
9935 c_write_str(ssh, ")\r\n");
9937 break; /* try something else */
9943 unsigned char *pkblob, *sigblob, *sigdata;
9944 int pkblob_len, sigblob_len, sigdata_len;
9948 * We have loaded the private key and the server
9949 * has announced that it's willing to accept it.
9950 * Hallelujah. Generate a signature and send it.
9952 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9953 ssh2_pkt_addstring(s->pktout, ssh->username);
9954 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9955 /* service requested */
9956 ssh2_pkt_addstring(s->pktout, "publickey");
9958 ssh2_pkt_addbool(s->pktout, TRUE);
9959 /* signature follows */
9960 ssh2_pkt_addstring(s->pktout, key->alg->name);
9961 pkblob = key->alg->public_blob(key->data,
9963 ssh2_pkt_addstring_start(s->pktout);
9964 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9968 * The data to be signed is:
9972 * followed by everything so far placed in the
9975 sigdata_len = s->pktout->length - 5 + 4 +
9976 ssh->v2_session_id_len;
9977 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9979 sigdata = snewn(sigdata_len, unsigned char);
9981 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9982 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9985 memcpy(sigdata+p, ssh->v2_session_id,
9986 ssh->v2_session_id_len);
9987 p += ssh->v2_session_id_len;
9988 memcpy(sigdata+p, s->pktout->data + 5,
9989 s->pktout->length - 5);
9990 p += s->pktout->length - 5;
9991 assert(p == sigdata_len);
9992 sigblob = key->alg->sign(key->data, (char *)sigdata,
9993 sigdata_len, &sigblob_len);
9994 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9995 sigblob, sigblob_len);
10000 ssh2_pkt_send(ssh, s->pktout);
10001 logevent("Sent public key signature");
10002 s->type = AUTH_TYPE_PUBLICKEY;
10003 key->alg->freekey(key->data);
10004 sfree(key->comment);
10009 } else if (s->can_gssapi && !s->tried_gssapi) {
10011 /* GSSAPI Authentication */
10013 int micoffset, len;
10016 s->type = AUTH_TYPE_GSSAPI;
10017 s->tried_gssapi = TRUE;
10019 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
10022 * Pick the highest GSS library on the preference
10028 for (i = 0; i < ngsslibs; i++) {
10029 int want_id = conf_get_int_int(ssh->conf,
10030 CONF_ssh_gsslist, i);
10031 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10032 if (ssh->gsslibs->libraries[j].id == want_id) {
10033 s->gsslib = &ssh->gsslibs->libraries[j];
10034 goto got_gsslib; /* double break */
10039 * We always expect to have found something in
10040 * the above loop: we only came here if there
10041 * was at least one viable GSS library, and the
10042 * preference list should always mention
10043 * everything and only change the order.
10048 if (s->gsslib->gsslogmsg)
10049 logevent(s->gsslib->gsslogmsg);
10051 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10052 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10053 ssh2_pkt_addstring(s->pktout, ssh->username);
10054 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10055 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10056 logevent("Attempting GSSAPI authentication");
10058 /* add mechanism info */
10059 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10061 /* number of GSSAPI mechanisms */
10062 ssh2_pkt_adduint32(s->pktout,1);
10064 /* length of OID + 2 */
10065 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10066 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10068 /* length of OID */
10069 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10071 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10072 s->gss_buf.length);
10073 ssh2_pkt_send(ssh, s->pktout);
10074 crWaitUntilV(pktin);
10075 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10076 logevent("GSSAPI authentication request refused");
10080 /* check returned packet ... */
10082 ssh_pkt_getstring(pktin, &data, &len);
10083 s->gss_rcvtok.value = data;
10084 s->gss_rcvtok.length = len;
10085 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10086 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10087 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10088 memcmp((char *)s->gss_rcvtok.value + 2,
10089 s->gss_buf.value,s->gss_buf.length) ) {
10090 logevent("GSSAPI authentication - wrong response from server");
10094 /* now start running */
10095 s->gss_stat = s->gsslib->import_name(s->gsslib,
10098 if (s->gss_stat != SSH_GSS_OK) {
10099 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10100 logevent("GSSAPI import name failed - Bad service name");
10102 logevent("GSSAPI import name failed");
10106 /* fetch TGT into GSS engine */
10107 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10109 if (s->gss_stat != SSH_GSS_OK) {
10110 logevent("GSSAPI authentication failed to get credentials");
10111 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10115 /* initial tokens are empty */
10116 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10117 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10119 /* now enter the loop */
10121 s->gss_stat = s->gsslib->init_sec_context
10125 conf_get_int(ssh->conf, CONF_gssapifwd),
10129 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10130 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10131 logevent("GSSAPI authentication initialisation failed");
10133 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10134 &s->gss_buf) == SSH_GSS_OK) {
10135 logevent(s->gss_buf.value);
10136 sfree(s->gss_buf.value);
10141 logevent("GSSAPI authentication initialised");
10143 /* Client and server now exchange tokens until GSSAPI
10144 * no longer says CONTINUE_NEEDED */
10146 if (s->gss_sndtok.length != 0) {
10147 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10148 ssh_pkt_addstring_start(s->pktout);
10149 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10150 ssh2_pkt_send(ssh, s->pktout);
10151 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10154 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10155 crWaitUntilV(pktin);
10156 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10157 logevent("GSSAPI authentication - bad server response");
10158 s->gss_stat = SSH_GSS_FAILURE;
10161 ssh_pkt_getstring(pktin, &data, &len);
10162 s->gss_rcvtok.value = data;
10163 s->gss_rcvtok.length = len;
10165 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10167 if (s->gss_stat != SSH_GSS_OK) {
10168 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10169 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10172 logevent("GSSAPI authentication loop finished OK");
10174 /* Now send the MIC */
10176 s->pktout = ssh2_pkt_init(0);
10177 micoffset = s->pktout->length;
10178 ssh_pkt_addstring_start(s->pktout);
10179 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10180 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10181 ssh_pkt_addstring(s->pktout, ssh->username);
10182 ssh_pkt_addstring(s->pktout, "ssh-connection");
10183 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10185 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10186 s->gss_buf.length = s->pktout->length - micoffset;
10188 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10189 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10190 ssh_pkt_addstring_start(s->pktout);
10191 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10192 ssh2_pkt_send(ssh, s->pktout);
10193 s->gsslib->free_mic(s->gsslib, &mic);
10197 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10198 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10201 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10204 * Keyboard-interactive authentication.
10207 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10209 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10211 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10212 ssh2_pkt_addstring(s->pktout, ssh->username);
10213 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10214 /* service requested */
10215 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10217 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10218 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10219 ssh2_pkt_send(ssh, s->pktout);
10221 logevent("Attempting keyboard-interactive authentication");
10223 crWaitUntilV(pktin);
10224 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10225 /* Server is not willing to do keyboard-interactive
10226 * at all (or, bizarrely but legally, accepts the
10227 * user without actually issuing any prompts).
10228 * Give up on it entirely. */
10230 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10231 s->kbd_inter_refused = TRUE; /* don't try it again */
10236 * Loop while the server continues to send INFO_REQUESTs.
10238 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10240 char *name, *inst, *lang;
10241 int name_len, inst_len, lang_len;
10245 * We've got a fresh USERAUTH_INFO_REQUEST.
10246 * Get the preamble and start building a prompt.
10248 ssh_pkt_getstring(pktin, &name, &name_len);
10249 ssh_pkt_getstring(pktin, &inst, &inst_len);
10250 ssh_pkt_getstring(pktin, &lang, &lang_len);
10251 s->cur_prompt = new_prompts(ssh->frontend);
10252 s->cur_prompt->to_server = TRUE;
10255 * Get any prompt(s) from the packet.
10257 s->num_prompts = ssh_pkt_getuint32(pktin);
10258 for (i = 0; i < s->num_prompts; i++) {
10262 static char noprompt[] =
10263 "<server failed to send prompt>: ";
10265 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10266 echo = ssh2_pkt_getbool(pktin);
10269 prompt_len = lenof(noprompt)-1;
10271 add_prompt(s->cur_prompt,
10272 dupprintf("%.*s", prompt_len, prompt),
10277 /* FIXME: better prefix to distinguish from
10278 * local prompts? */
10279 s->cur_prompt->name =
10280 dupprintf("SSH server: %.*s", name_len, name);
10281 s->cur_prompt->name_reqd = TRUE;
10283 s->cur_prompt->name =
10284 dupstr("SSH server authentication");
10285 s->cur_prompt->name_reqd = FALSE;
10287 /* We add a prefix to try to make it clear that a prompt
10288 * has come from the server.
10289 * FIXME: ugly to print "Using..." in prompt _every_
10290 * time round. Can this be done more subtly? */
10291 /* Special case: for reasons best known to themselves,
10292 * some servers send k-i requests with no prompts and
10293 * nothing to display. Keep quiet in this case. */
10294 if (s->num_prompts || name_len || inst_len) {
10295 s->cur_prompt->instruction =
10296 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10297 inst_len ? "\n" : "", inst_len, inst);
10298 s->cur_prompt->instr_reqd = TRUE;
10300 s->cur_prompt->instr_reqd = FALSE;
10304 * Display any instructions, and get the user's
10308 int ret; /* not live over crReturn */
10309 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10312 crWaitUntilV(!pktin);
10313 ret = get_userpass_input(s->cur_prompt, in, inlen);
10318 * Failed to get responses. Terminate.
10320 free_prompts(s->cur_prompt);
10321 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10322 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10329 * Send the response(s) to the server.
10331 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10332 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10333 for (i=0; i < s->num_prompts; i++) {
10334 ssh2_pkt_addstring(s->pktout,
10335 s->cur_prompt->prompts[i]->result);
10337 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10340 * Free the prompts structure from this iteration.
10341 * If there's another, a new one will be allocated
10342 * when we return to the top of this while loop.
10344 free_prompts(s->cur_prompt);
10347 * Get the next packet in case it's another
10350 crWaitUntilV(pktin);
10355 * We should have SUCCESS or FAILURE now.
10359 } else if (s->can_passwd) {
10362 * Plain old password authentication.
10364 int ret; /* not live over crReturn */
10365 int changereq_first_time; /* not live over crReturn */
10367 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10369 s->cur_prompt = new_prompts(ssh->frontend);
10370 s->cur_prompt->to_server = TRUE;
10371 s->cur_prompt->name = dupstr("SSH password");
10372 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10377 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10380 crWaitUntilV(!pktin);
10381 ret = get_userpass_input(s->cur_prompt, in, inlen);
10386 * Failed to get responses. Terminate.
10388 free_prompts(s->cur_prompt);
10389 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10390 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10395 * Squirrel away the password. (We may need it later if
10396 * asked to change it.)
10398 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10399 free_prompts(s->cur_prompt);
10402 * Send the password packet.
10404 * We pad out the password packet to 256 bytes to make
10405 * it harder for an attacker to find the length of the
10408 * Anyone using a password longer than 256 bytes
10409 * probably doesn't have much to worry about from
10410 * people who find out how long their password is!
10412 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10413 ssh2_pkt_addstring(s->pktout, ssh->username);
10414 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10415 /* service requested */
10416 ssh2_pkt_addstring(s->pktout, "password");
10417 ssh2_pkt_addbool(s->pktout, FALSE);
10418 ssh2_pkt_addstring(s->pktout, s->password);
10419 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10420 logevent("Sent password");
10421 s->type = AUTH_TYPE_PASSWORD;
10424 * Wait for next packet, in case it's a password change
10427 crWaitUntilV(pktin);
10428 changereq_first_time = TRUE;
10430 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10433 * We're being asked for a new password
10434 * (perhaps not for the first time).
10435 * Loop until the server accepts it.
10438 int got_new = FALSE; /* not live over crReturn */
10439 char *prompt; /* not live over crReturn */
10440 int prompt_len; /* not live over crReturn */
10444 if (changereq_first_time)
10445 msg = "Server requested password change";
10447 msg = "Server rejected new password";
10449 c_write_str(ssh, msg);
10450 c_write_str(ssh, "\r\n");
10453 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10455 s->cur_prompt = new_prompts(ssh->frontend);
10456 s->cur_prompt->to_server = TRUE;
10457 s->cur_prompt->name = dupstr("New SSH password");
10458 s->cur_prompt->instruction =
10459 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10460 s->cur_prompt->instr_reqd = TRUE;
10462 * There's no explicit requirement in the protocol
10463 * for the "old" passwords in the original and
10464 * password-change messages to be the same, and
10465 * apparently some Cisco kit supports password change
10466 * by the user entering a blank password originally
10467 * and the real password subsequently, so,
10468 * reluctantly, we prompt for the old password again.
10470 * (On the other hand, some servers don't even bother
10471 * to check this field.)
10473 add_prompt(s->cur_prompt,
10474 dupstr("Current password (blank for previously entered password): "),
10476 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10478 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10482 * Loop until the user manages to enter the same
10487 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10490 crWaitUntilV(!pktin);
10491 ret = get_userpass_input(s->cur_prompt, in, inlen);
10496 * Failed to get responses. Terminate.
10498 /* burn the evidence */
10499 free_prompts(s->cur_prompt);
10500 smemclr(s->password, strlen(s->password));
10501 sfree(s->password);
10502 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10503 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10509 * If the user specified a new original password
10510 * (IYSWIM), overwrite any previously specified
10512 * (A side effect is that the user doesn't have to
10513 * re-enter it if they louse up the new password.)
10515 if (s->cur_prompt->prompts[0]->result[0]) {
10516 smemclr(s->password, strlen(s->password));
10517 /* burn the evidence */
10518 sfree(s->password);
10520 dupstr(s->cur_prompt->prompts[0]->result);
10524 * Check the two new passwords match.
10526 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10527 s->cur_prompt->prompts[2]->result)
10530 /* They don't. Silly user. */
10531 c_write_str(ssh, "Passwords do not match\r\n");
10536 * Send the new password (along with the old one).
10537 * (see above for padding rationale)
10539 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10540 ssh2_pkt_addstring(s->pktout, ssh->username);
10541 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10542 /* service requested */
10543 ssh2_pkt_addstring(s->pktout, "password");
10544 ssh2_pkt_addbool(s->pktout, TRUE);
10545 ssh2_pkt_addstring(s->pktout, s->password);
10546 ssh2_pkt_addstring(s->pktout,
10547 s->cur_prompt->prompts[1]->result);
10548 free_prompts(s->cur_prompt);
10549 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10550 logevent("Sent new password");
10553 * Now see what the server has to say about it.
10554 * (If it's CHANGEREQ again, it's not happy with the
10557 crWaitUntilV(pktin);
10558 changereq_first_time = FALSE;
10563 * We need to reexamine the current pktin at the top
10564 * of the loop. Either:
10565 * - we weren't asked to change password at all, in
10566 * which case it's a SUCCESS or FAILURE with the
10568 * - we sent a new password, and the server was
10569 * either OK with it (SUCCESS or FAILURE w/partial
10570 * success) or unhappy with the _old_ password
10571 * (FAILURE w/o partial success)
10572 * In any of these cases, we go back to the top of
10573 * the loop and start again.
10578 * We don't need the old password any more, in any
10579 * case. Burn the evidence.
10581 smemclr(s->password, strlen(s->password));
10582 sfree(s->password);
10585 char *str = dupprintf("No supported authentication methods available"
10586 " (server sent: %.*s)",
10589 ssh_disconnect(ssh, str,
10590 "No supported authentication methods available",
10591 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10601 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10603 /* Clear up various bits and pieces from authentication. */
10604 if (s->publickey_blob) {
10605 sfree(s->publickey_algorithm);
10606 sfree(s->publickey_blob);
10607 sfree(s->publickey_comment);
10609 if (s->agent_response)
10610 sfree(s->agent_response);
10612 if (s->userauth_success && !ssh->bare_connection) {
10614 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10615 * packets since. Signal the transport layer to consider enacting
10616 * delayed compression.
10618 * (Relying on we_are_in is not sufficient, as
10619 * draft-miller-secsh-compression-delayed is quite clear that it
10620 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10621 * become set for other reasons.)
10623 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10626 ssh->channels = newtree234(ssh_channelcmp);
10629 * Set up handlers for some connection protocol messages, so we
10630 * don't have to handle them repeatedly in this coroutine.
10632 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10633 ssh2_msg_channel_window_adjust;
10634 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10635 ssh2_msg_global_request;
10638 * Create the main session channel.
10640 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10641 ssh->mainchan = NULL;
10643 ssh->mainchan = snew(struct ssh_channel);
10644 ssh->mainchan->ssh = ssh;
10645 ssh_channel_init(ssh->mainchan);
10647 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10649 * Just start a direct-tcpip channel and use it as the main
10652 ssh_send_port_open(ssh->mainchan,
10653 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10654 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10656 ssh->ncmode = TRUE;
10658 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10659 logevent("Opening session as main channel");
10660 ssh2_pkt_send(ssh, s->pktout);
10661 ssh->ncmode = FALSE;
10663 crWaitUntilV(pktin);
10664 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10665 bombout(("Server refused to open channel"));
10667 /* FIXME: error data comes back in FAILURE packet */
10669 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10670 bombout(("Server's channel confirmation cited wrong channel"));
10673 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10674 ssh->mainchan->halfopen = FALSE;
10675 ssh->mainchan->type = CHAN_MAINSESSION;
10676 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10677 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10678 update_specials_menu(ssh->frontend);
10679 logevent("Opened main channel");
10683 * Now we have a channel, make dispatch table entries for
10684 * general channel-based messages.
10686 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10687 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10688 ssh2_msg_channel_data;
10689 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10690 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10691 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10692 ssh2_msg_channel_open_confirmation;
10693 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10694 ssh2_msg_channel_open_failure;
10695 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10696 ssh2_msg_channel_request;
10697 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10698 ssh2_msg_channel_open;
10699 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10700 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10703 * Now the connection protocol is properly up and running, with
10704 * all those dispatch table entries, so it's safe to let
10705 * downstreams start trying to open extra channels through us.
10707 if (ssh->connshare)
10708 share_activate(ssh->connshare, ssh->v_s);
10710 if (ssh->mainchan && ssh_is_simple(ssh)) {
10712 * This message indicates to the server that we promise
10713 * not to try to run any other channel in parallel with
10714 * this one, so it's safe for it to advertise a very large
10715 * window and leave the flow control to TCP.
10717 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10718 "simple@putty.projects.tartarus.org",
10720 ssh2_pkt_send(ssh, s->pktout);
10724 * Enable port forwardings.
10726 ssh_setup_portfwd(ssh, ssh->conf);
10728 if (ssh->mainchan && !ssh->ncmode) {
10730 * Send the CHANNEL_REQUESTS for the main session channel.
10731 * Each one is handled by its own little asynchronous
10735 /* Potentially enable X11 forwarding. */
10736 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10738 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10740 if (!ssh->x11disp) {
10741 /* FIXME: return an error message from x11_setup_display */
10742 logevent("X11 forwarding not enabled: unable to"
10743 " initialise X display");
10745 ssh->x11auth = x11_invent_fake_auth
10746 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10747 ssh->x11auth->disp = ssh->x11disp;
10749 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10753 /* Potentially enable agent forwarding. */
10754 if (ssh_agent_forwarding_permitted(ssh))
10755 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10757 /* Now allocate a pty for the session. */
10758 if (!conf_get_int(ssh->conf, CONF_nopty))
10759 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10761 /* Send environment variables. */
10762 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10765 * Start a shell or a remote command. We may have to attempt
10766 * this twice if the config data has provided a second choice
10773 if (ssh->fallback_cmd) {
10774 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10775 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10777 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10778 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10782 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10783 ssh2_response_authconn, NULL);
10784 ssh2_pkt_addstring(s->pktout, cmd);
10786 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10787 ssh2_response_authconn, NULL);
10788 ssh2_pkt_addstring(s->pktout, cmd);
10790 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10791 ssh2_response_authconn, NULL);
10793 ssh2_pkt_send(ssh, s->pktout);
10795 crWaitUntilV(pktin);
10797 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10798 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10799 bombout(("Unexpected response to shell/command request:"
10800 " packet type %d", pktin->type));
10804 * We failed to start the command. If this is the
10805 * fallback command, we really are finished; if it's
10806 * not, and if the fallback command exists, try falling
10807 * back to it before complaining.
10809 if (!ssh->fallback_cmd &&
10810 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10811 logevent("Primary command failed; attempting fallback");
10812 ssh->fallback_cmd = TRUE;
10815 bombout(("Server refused to start a shell/command"));
10818 logevent("Started a shell/command");
10823 ssh->editing = ssh->echoing = TRUE;
10826 ssh->state = SSH_STATE_SESSION;
10827 if (ssh->size_needed)
10828 ssh_size(ssh, ssh->term_width, ssh->term_height);
10829 if (ssh->eof_needed)
10830 ssh_special(ssh, TS_EOF);
10836 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10844 * _All_ the connection-layer packets we expect to
10845 * receive are now handled by the dispatch table.
10846 * Anything that reaches here must be bogus.
10849 bombout(("Strange packet received: type %d", pktin->type));
10851 } else if (ssh->mainchan) {
10853 * We have spare data. Add it to the channel buffer.
10855 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10863 * Handlers for SSH-2 messages that might arrive at any moment.
10865 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10867 /* log reason code in disconnect message */
10869 int reason, msglen;
10871 reason = ssh_pkt_getuint32(pktin);
10872 ssh_pkt_getstring(pktin, &msg, &msglen);
10874 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10875 buf = dupprintf("Received disconnect message (%s)",
10876 ssh2_disconnect_reasons[reason]);
10878 buf = dupprintf("Received disconnect message (unknown"
10879 " type %d)", reason);
10883 buf = dupprintf("Disconnection message text: %.*s",
10884 msglen, NULLTOEMPTY(msg));
10886 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10888 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10889 ssh2_disconnect_reasons[reason] : "unknown",
10890 msglen, NULLTOEMPTY(msg)));
10894 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10896 /* log the debug message */
10900 /* XXX maybe we should actually take notice of the return value */
10901 ssh2_pkt_getbool(pktin);
10902 ssh_pkt_getstring(pktin, &msg, &msglen);
10904 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10907 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10909 do_ssh2_transport(ssh, NULL, 0, pktin);
10913 * Called if we receive a packet that isn't allowed by the protocol.
10914 * This only applies to packets whose meaning PuTTY understands.
10915 * Entirely unknown packets are handled below.
10917 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10919 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10920 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10922 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10926 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10928 struct Packet *pktout;
10929 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10930 ssh2_pkt_adduint32(pktout, pktin->sequence);
10932 * UNIMPLEMENTED messages MUST appear in the same order as the
10933 * messages they respond to. Hence, never queue them.
10935 ssh2_pkt_send_noqueue(ssh, pktout);
10939 * Handle the top-level SSH-2 protocol.
10941 static void ssh2_protocol_setup(Ssh ssh)
10946 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10948 for (i = 0; i < 256; i++)
10949 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10952 * Initially, we only accept transport messages (and a few generic
10953 * ones). do_ssh2_authconn will add more when it starts.
10954 * Messages that are understood but not currently acceptable go to
10955 * ssh2_msg_unexpected.
10957 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10958 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10959 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10960 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10961 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10962 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10963 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10964 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10965 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10966 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10967 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10968 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10969 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10970 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10971 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10972 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10973 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10974 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10975 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10976 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10977 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10978 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10980 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10982 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10983 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10984 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10985 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10986 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10988 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10992 * These messages have a special handler from the start.
10994 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10995 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10996 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10999 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
11004 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
11006 for (i = 0; i < 256; i++)
11007 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
11010 * Initially, we set all ssh-connection messages to 'unexpected';
11011 * do_ssh2_authconn will fill things in properly. We also handle a
11012 * couple of messages from the transport protocol which aren't
11013 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
11016 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11017 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11018 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11025 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11026 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11027 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11028 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11029 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11031 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11034 * These messages have a special handler from the start.
11036 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11037 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11038 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11041 static void ssh2_timer(void *ctx, unsigned long now)
11043 Ssh ssh = (Ssh)ctx;
11045 if (ssh->state == SSH_STATE_CLOSED)
11048 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11049 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11050 now == ssh->next_rekey) {
11051 do_ssh2_transport(ssh, "timeout", -1, NULL);
11055 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11056 struct Packet *pktin)
11058 const unsigned char *in = (const unsigned char *)vin;
11059 if (ssh->state == SSH_STATE_CLOSED)
11063 ssh->incoming_data_size += pktin->encrypted_len;
11064 if (!ssh->kex_in_progress &&
11065 ssh->max_data_size != 0 &&
11066 ssh->incoming_data_size > ssh->max_data_size)
11067 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11071 ssh->packet_dispatch[pktin->type](ssh, pktin);
11072 else if (!ssh->protocol_initial_phase_done)
11073 do_ssh2_transport(ssh, in, inlen, pktin);
11075 do_ssh2_authconn(ssh, in, inlen, pktin);
11078 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11079 struct Packet *pktin)
11081 const unsigned char *in = (const unsigned char *)vin;
11082 if (ssh->state == SSH_STATE_CLOSED)
11086 ssh->packet_dispatch[pktin->type](ssh, pktin);
11088 do_ssh2_authconn(ssh, in, inlen, pktin);
11091 static void ssh_cache_conf_values(Ssh ssh)
11093 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11097 * Called to set up the connection.
11099 * Returns an error message, or NULL on success.
11101 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11103 const char *host, int port, char **realhost,
11104 int nodelay, int keepalive)
11109 ssh = snew(struct ssh_tag);
11110 ssh->conf = conf_copy(conf);
11111 ssh_cache_conf_values(ssh);
11112 ssh->version = 0; /* when not ready yet */
11114 ssh->cipher = NULL;
11115 ssh->v1_cipher_ctx = NULL;
11116 ssh->crcda_ctx = NULL;
11117 ssh->cscipher = NULL;
11118 ssh->cs_cipher_ctx = NULL;
11119 ssh->sccipher = NULL;
11120 ssh->sc_cipher_ctx = NULL;
11122 ssh->cs_mac_ctx = NULL;
11124 ssh->sc_mac_ctx = NULL;
11125 ssh->cscomp = NULL;
11126 ssh->cs_comp_ctx = NULL;
11127 ssh->sccomp = NULL;
11128 ssh->sc_comp_ctx = NULL;
11130 ssh->kex_ctx = NULL;
11131 ssh->hostkey = NULL;
11132 ssh->hostkey_str = NULL;
11133 ssh->exitcode = -1;
11134 ssh->close_expected = FALSE;
11135 ssh->clean_exit = FALSE;
11136 ssh->state = SSH_STATE_PREPACKET;
11137 ssh->size_needed = FALSE;
11138 ssh->eof_needed = FALSE;
11140 ssh->logctx = NULL;
11141 ssh->deferred_send_data = NULL;
11142 ssh->deferred_len = 0;
11143 ssh->deferred_size = 0;
11144 ssh->fallback_cmd = 0;
11145 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11146 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11147 ssh->x11disp = NULL;
11148 ssh->x11auth = NULL;
11149 ssh->x11authtree = newtree234(x11_authcmp);
11150 ssh->v1_compressing = FALSE;
11151 ssh->v2_outgoing_sequence = 0;
11152 ssh->ssh1_rdpkt_crstate = 0;
11153 ssh->ssh2_rdpkt_crstate = 0;
11154 ssh->ssh2_bare_rdpkt_crstate = 0;
11155 ssh->ssh_gotdata_crstate = 0;
11156 ssh->do_ssh1_connection_crstate = 0;
11157 ssh->do_ssh_init_state = NULL;
11158 ssh->do_ssh_connection_init_state = NULL;
11159 ssh->do_ssh1_login_state = NULL;
11160 ssh->do_ssh2_transport_state = NULL;
11161 ssh->do_ssh2_authconn_state = NULL;
11164 ssh->mainchan = NULL;
11165 ssh->throttled_all = 0;
11166 ssh->v1_stdout_throttling = 0;
11168 ssh->queuelen = ssh->queuesize = 0;
11169 ssh->queueing = FALSE;
11170 ssh->qhead = ssh->qtail = NULL;
11171 ssh->deferred_rekey_reason = NULL;
11172 bufchain_init(&ssh->queued_incoming_data);
11173 ssh->frozen = FALSE;
11174 ssh->username = NULL;
11175 ssh->sent_console_eof = FALSE;
11176 ssh->got_pty = FALSE;
11177 ssh->bare_connection = FALSE;
11178 ssh->X11_fwd_enabled = FALSE;
11179 ssh->connshare = NULL;
11180 ssh->attempting_connshare = FALSE;
11181 ssh->session_started = FALSE;
11182 ssh->specials = NULL;
11183 ssh->n_uncert_hostkeys = 0;
11184 ssh->cross_certifying = FALSE;
11186 *backend_handle = ssh;
11189 if (crypto_startup() == 0)
11190 return "Microsoft high encryption pack not installed!";
11193 ssh->frontend = frontend_handle;
11194 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11195 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11197 ssh->channels = NULL;
11198 ssh->rportfwds = NULL;
11199 ssh->portfwds = NULL;
11204 ssh->conn_throttle_count = 0;
11205 ssh->overall_bufsize = 0;
11206 ssh->fallback_cmd = 0;
11208 ssh->protocol = NULL;
11210 ssh->protocol_initial_phase_done = FALSE;
11212 ssh->pinger = NULL;
11214 ssh->incoming_data_size = ssh->outgoing_data_size =
11215 ssh->deferred_data_size = 0L;
11216 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11217 CONF_ssh_rekey_data));
11218 ssh->kex_in_progress = FALSE;
11221 ssh->gsslibs = NULL;
11224 random_ref(); /* do this now - may be needed by sharing setup code */
11226 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11235 static void ssh_free(void *handle)
11237 Ssh ssh = (Ssh) handle;
11238 struct ssh_channel *c;
11239 struct ssh_rportfwd *pf;
11240 struct X11FakeAuth *auth;
11242 if (ssh->v1_cipher_ctx)
11243 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11244 if (ssh->cs_cipher_ctx)
11245 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11246 if (ssh->sc_cipher_ctx)
11247 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11248 if (ssh->cs_mac_ctx)
11249 ssh->csmac->free_context(ssh->cs_mac_ctx);
11250 if (ssh->sc_mac_ctx)
11251 ssh->scmac->free_context(ssh->sc_mac_ctx);
11252 if (ssh->cs_comp_ctx) {
11254 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11256 zlib_compress_cleanup(ssh->cs_comp_ctx);
11258 if (ssh->sc_comp_ctx) {
11260 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11262 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11265 dh_cleanup(ssh->kex_ctx);
11266 sfree(ssh->savedhost);
11268 while (ssh->queuelen-- > 0)
11269 ssh_free_packet(ssh->queue[ssh->queuelen]);
11272 while (ssh->qhead) {
11273 struct queued_handler *qh = ssh->qhead;
11274 ssh->qhead = qh->next;
11277 ssh->qhead = ssh->qtail = NULL;
11279 if (ssh->channels) {
11280 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11283 if (c->u.x11.xconn != NULL)
11284 x11_close(c->u.x11.xconn);
11286 case CHAN_SOCKDATA:
11287 case CHAN_SOCKDATA_DORMANT:
11288 if (c->u.pfd.pf != NULL)
11289 pfd_close(c->u.pfd.pf);
11292 if (ssh->version == 2) {
11293 struct outstanding_channel_request *ocr, *nocr;
11294 ocr = c->v.v2.chanreq_head;
11296 ocr->handler(c, NULL, ocr->ctx);
11301 bufchain_clear(&c->v.v2.outbuffer);
11305 freetree234(ssh->channels);
11306 ssh->channels = NULL;
11309 if (ssh->connshare)
11310 sharestate_free(ssh->connshare);
11312 if (ssh->rportfwds) {
11313 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11315 freetree234(ssh->rportfwds);
11316 ssh->rportfwds = NULL;
11318 sfree(ssh->deferred_send_data);
11320 x11_free_display(ssh->x11disp);
11321 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11322 x11_free_fake_auth(auth);
11323 freetree234(ssh->x11authtree);
11324 sfree(ssh->do_ssh_init_state);
11325 sfree(ssh->do_ssh1_login_state);
11326 sfree(ssh->do_ssh2_transport_state);
11327 sfree(ssh->do_ssh2_authconn_state);
11330 sfree(ssh->fullhostname);
11331 sfree(ssh->hostkey_str);
11332 sfree(ssh->specials);
11333 if (ssh->crcda_ctx) {
11334 crcda_free_context(ssh->crcda_ctx);
11335 ssh->crcda_ctx = NULL;
11338 ssh_do_close(ssh, TRUE);
11339 expire_timer_context(ssh);
11341 pinger_free(ssh->pinger);
11342 bufchain_clear(&ssh->queued_incoming_data);
11343 sfree(ssh->username);
11344 conf_free(ssh->conf);
11347 ssh_gss_cleanup(ssh->gsslibs);
11355 * Reconfigure the SSH backend.
11357 static void ssh_reconfig(void *handle, Conf *conf)
11359 Ssh ssh = (Ssh) handle;
11360 const char *rekeying = NULL;
11361 int rekey_mandatory = FALSE;
11362 unsigned long old_max_data_size;
11365 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11367 ssh_setup_portfwd(ssh, conf);
11369 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11370 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11372 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11373 unsigned long now = GETTICKCOUNT();
11375 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11376 rekeying = "timeout shortened";
11378 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11382 old_max_data_size = ssh->max_data_size;
11383 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11384 CONF_ssh_rekey_data));
11385 if (old_max_data_size != ssh->max_data_size &&
11386 ssh->max_data_size != 0) {
11387 if (ssh->outgoing_data_size > ssh->max_data_size ||
11388 ssh->incoming_data_size > ssh->max_data_size)
11389 rekeying = "data limit lowered";
11392 if (conf_get_int(ssh->conf, CONF_compression) !=
11393 conf_get_int(conf, CONF_compression)) {
11394 rekeying = "compression setting changed";
11395 rekey_mandatory = TRUE;
11398 for (i = 0; i < CIPHER_MAX; i++)
11399 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11400 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11401 rekeying = "cipher settings changed";
11402 rekey_mandatory = TRUE;
11404 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11405 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11406 rekeying = "cipher settings changed";
11407 rekey_mandatory = TRUE;
11410 conf_free(ssh->conf);
11411 ssh->conf = conf_copy(conf);
11412 ssh_cache_conf_values(ssh);
11414 if (!ssh->bare_connection && rekeying) {
11415 if (!ssh->kex_in_progress) {
11416 do_ssh2_transport(ssh, rekeying, -1, NULL);
11417 } else if (rekey_mandatory) {
11418 ssh->deferred_rekey_reason = rekeying;
11424 * Called to send data down the SSH connection.
11426 static int ssh_send(void *handle, const char *buf, int len)
11428 Ssh ssh = (Ssh) handle;
11430 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11433 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11435 return ssh_sendbuffer(ssh);
11439 * Called to query the current amount of buffered stdin data.
11441 static int ssh_sendbuffer(void *handle)
11443 Ssh ssh = (Ssh) handle;
11444 int override_value;
11446 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11450 * If the SSH socket itself has backed up, add the total backup
11451 * size on that to any individual buffer on the stdin channel.
11453 override_value = 0;
11454 if (ssh->throttled_all)
11455 override_value = ssh->overall_bufsize;
11457 if (ssh->version == 1) {
11458 return override_value;
11459 } else if (ssh->version == 2) {
11460 if (!ssh->mainchan)
11461 return override_value;
11463 return (override_value +
11464 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11471 * Called to set the size of the window from SSH's POV.
11473 static void ssh_size(void *handle, int width, int height)
11475 Ssh ssh = (Ssh) handle;
11476 struct Packet *pktout;
11478 ssh->term_width = width;
11479 ssh->term_height = height;
11481 switch (ssh->state) {
11482 case SSH_STATE_BEFORE_SIZE:
11483 case SSH_STATE_PREPACKET:
11484 case SSH_STATE_CLOSED:
11485 break; /* do nothing */
11486 case SSH_STATE_INTERMED:
11487 ssh->size_needed = TRUE; /* buffer for later */
11489 case SSH_STATE_SESSION:
11490 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11491 if (ssh->version == 1) {
11492 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11493 PKT_INT, ssh->term_height,
11494 PKT_INT, ssh->term_width,
11495 PKT_INT, 0, PKT_INT, 0, PKT_END);
11496 } else if (ssh->mainchan) {
11497 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11499 ssh2_pkt_adduint32(pktout, ssh->term_width);
11500 ssh2_pkt_adduint32(pktout, ssh->term_height);
11501 ssh2_pkt_adduint32(pktout, 0);
11502 ssh2_pkt_adduint32(pktout, 0);
11503 ssh2_pkt_send(ssh, pktout);
11511 * Return a list of the special codes that make sense in this
11514 static const struct telnet_special *ssh_get_specials(void *handle)
11516 static const struct telnet_special ssh1_ignore_special[] = {
11517 {"IGNORE message", TS_NOP}
11519 static const struct telnet_special ssh2_ignore_special[] = {
11520 {"IGNORE message", TS_NOP},
11522 static const struct telnet_special ssh2_rekey_special[] = {
11523 {"Repeat key exchange", TS_REKEY},
11525 static const struct telnet_special ssh2_session_specials[] = {
11528 /* These are the signal names defined by RFC 4254.
11529 * They include all the ISO C signals, but are a subset of the POSIX
11530 * required signals. */
11531 {"SIGINT (Interrupt)", TS_SIGINT},
11532 {"SIGTERM (Terminate)", TS_SIGTERM},
11533 {"SIGKILL (Kill)", TS_SIGKILL},
11534 {"SIGQUIT (Quit)", TS_SIGQUIT},
11535 {"SIGHUP (Hangup)", TS_SIGHUP},
11536 {"More signals", TS_SUBMENU},
11537 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11538 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11539 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11540 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11541 {NULL, TS_EXITMENU}
11543 static const struct telnet_special specials_end[] = {
11544 {NULL, TS_EXITMENU}
11547 struct telnet_special *specials = NULL;
11548 int nspecials = 0, specialsize = 0;
11550 Ssh ssh = (Ssh) handle;
11552 sfree(ssh->specials);
11554 #define ADD_SPECIALS(name) do \
11556 int len = lenof(name); \
11557 if (nspecials + len > specialsize) { \
11558 specialsize = (nspecials + len) * 5 / 4 + 32; \
11559 specials = sresize(specials, specialsize, struct telnet_special); \
11561 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11562 nspecials += len; \
11565 if (ssh->version == 1) {
11566 /* Don't bother offering IGNORE if we've decided the remote
11567 * won't cope with it, since we wouldn't bother sending it if
11569 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11570 ADD_SPECIALS(ssh1_ignore_special);
11571 } else if (ssh->version == 2) {
11572 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11573 ADD_SPECIALS(ssh2_ignore_special);
11574 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11575 ADD_SPECIALS(ssh2_rekey_special);
11577 ADD_SPECIALS(ssh2_session_specials);
11579 if (ssh->n_uncert_hostkeys) {
11580 static const struct telnet_special uncert_start[] = {
11582 {"Cache new host key type", TS_SUBMENU},
11584 static const struct telnet_special uncert_end[] = {
11585 {NULL, TS_EXITMENU},
11589 ADD_SPECIALS(uncert_start);
11590 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11591 struct telnet_special uncert[1];
11592 const struct ssh_signkey *alg =
11593 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11594 uncert[0].name = alg->name;
11595 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11596 ADD_SPECIALS(uncert);
11598 ADD_SPECIALS(uncert_end);
11600 } /* else we're not ready yet */
11603 ADD_SPECIALS(specials_end);
11605 ssh->specials = specials;
11612 #undef ADD_SPECIALS
11616 * Send special codes. TS_EOF is useful for `plink', so you
11617 * can send an EOF and collect resulting output (e.g. `plink
11620 static void ssh_special(void *handle, Telnet_Special code)
11622 Ssh ssh = (Ssh) handle;
11623 struct Packet *pktout;
11625 if (code == TS_EOF) {
11626 if (ssh->state != SSH_STATE_SESSION) {
11628 * Buffer the EOF in case we are pre-SESSION, so we can
11629 * send it as soon as we reach SESSION.
11631 if (code == TS_EOF)
11632 ssh->eof_needed = TRUE;
11635 if (ssh->version == 1) {
11636 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11637 } else if (ssh->mainchan) {
11638 sshfwd_write_eof(ssh->mainchan);
11639 ssh->send_ok = 0; /* now stop trying to read from stdin */
11641 logevent("Sent EOF message");
11642 } else if (code == TS_PING || code == TS_NOP) {
11643 if (ssh->state == SSH_STATE_CLOSED
11644 || ssh->state == SSH_STATE_PREPACKET) return;
11645 if (ssh->version == 1) {
11646 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11647 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11649 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11650 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11651 ssh2_pkt_addstring_start(pktout);
11652 ssh2_pkt_send_noqueue(ssh, pktout);
11655 } else if (code == TS_REKEY) {
11656 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11657 ssh->version == 2) {
11658 do_ssh2_transport(ssh, "at user request", -1, NULL);
11660 } else if (code >= TS_LOCALSTART) {
11661 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11662 ssh->cross_certifying = TRUE;
11663 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11664 ssh->version == 2) {
11665 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11667 } else if (code == TS_BRK) {
11668 if (ssh->state == SSH_STATE_CLOSED
11669 || ssh->state == SSH_STATE_PREPACKET) return;
11670 if (ssh->version == 1) {
11671 logevent("Unable to send BREAK signal in SSH-1");
11672 } else if (ssh->mainchan) {
11673 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11674 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11675 ssh2_pkt_send(ssh, pktout);
11678 /* Is is a POSIX signal? */
11679 const char *signame = NULL;
11680 if (code == TS_SIGABRT) signame = "ABRT";
11681 if (code == TS_SIGALRM) signame = "ALRM";
11682 if (code == TS_SIGFPE) signame = "FPE";
11683 if (code == TS_SIGHUP) signame = "HUP";
11684 if (code == TS_SIGILL) signame = "ILL";
11685 if (code == TS_SIGINT) signame = "INT";
11686 if (code == TS_SIGKILL) signame = "KILL";
11687 if (code == TS_SIGPIPE) signame = "PIPE";
11688 if (code == TS_SIGQUIT) signame = "QUIT";
11689 if (code == TS_SIGSEGV) signame = "SEGV";
11690 if (code == TS_SIGTERM) signame = "TERM";
11691 if (code == TS_SIGUSR1) signame = "USR1";
11692 if (code == TS_SIGUSR2) signame = "USR2";
11693 /* The SSH-2 protocol does in principle support arbitrary named
11694 * signals, including signame@domain, but we don't support those. */
11696 /* It's a signal. */
11697 if (ssh->version == 2 && ssh->mainchan) {
11698 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11699 ssh2_pkt_addstring(pktout, signame);
11700 ssh2_pkt_send(ssh, pktout);
11701 logeventf(ssh, "Sent signal SIG%s", signame);
11704 /* Never heard of it. Do nothing */
11709 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11711 Ssh ssh = (Ssh) handle;
11712 struct ssh_channel *c;
11713 c = snew(struct ssh_channel);
11716 ssh_channel_init(c);
11717 c->halfopen = TRUE;
11718 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11723 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11725 struct ssh_channel *c;
11726 c = snew(struct ssh_channel);
11729 ssh_channel_init(c);
11730 c->type = CHAN_SHARING;
11731 c->u.sharing.ctx = sharing_ctx;
11735 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11737 struct ssh_channel *c;
11739 c = find234(ssh->channels, &localid, ssh_channelfind);
11741 ssh_channel_destroy(c);
11744 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11745 const void *data, int datalen,
11746 const char *additional_log_text)
11748 struct Packet *pkt;
11750 pkt = ssh2_pkt_init(type);
11751 pkt->downstream_id = id;
11752 pkt->additional_log_text = additional_log_text;
11753 ssh2_pkt_adddata(pkt, data, datalen);
11754 ssh2_pkt_send(ssh, pkt);
11758 * This is called when stdout/stderr (the entity to which
11759 * from_backend sends data) manages to clear some backlog.
11761 static void ssh_unthrottle(void *handle, int bufsize)
11763 Ssh ssh = (Ssh) handle;
11765 if (ssh->version == 1) {
11766 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11767 ssh->v1_stdout_throttling = 0;
11768 ssh_throttle_conn(ssh, -1);
11772 ssh_channel_unthrottle(ssh->mainchan, bufsize);
11776 * Now process any SSH connection data that was stashed in our
11777 * queue while we were frozen.
11779 ssh_process_queued_incoming_data(ssh);
11782 void ssh_send_port_open(void *channel, const char *hostname, int port,
11785 struct ssh_channel *c = (struct ssh_channel *)channel;
11787 struct Packet *pktout;
11789 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11791 if (ssh->version == 1) {
11792 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11793 PKT_INT, c->localid,
11796 /* PKT_STR, <org:orgport>, */
11799 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11801 char *trimmed_host = host_strduptrim(hostname);
11802 ssh2_pkt_addstring(pktout, trimmed_host);
11803 sfree(trimmed_host);
11805 ssh2_pkt_adduint32(pktout, port);
11807 * We make up values for the originator data; partly it's
11808 * too much hassle to keep track, and partly I'm not
11809 * convinced the server should be told details like that
11810 * about my local network configuration.
11811 * The "originator IP address" is syntactically a numeric
11812 * IP address, and some servers (e.g., Tectia) get upset
11813 * if it doesn't match this syntax.
11815 ssh2_pkt_addstring(pktout, "0.0.0.0");
11816 ssh2_pkt_adduint32(pktout, 0);
11817 ssh2_pkt_send(ssh, pktout);
11821 static int ssh_connected(void *handle)
11823 Ssh ssh = (Ssh) handle;
11824 return ssh->s != NULL;
11827 static int ssh_sendok(void *handle)
11829 Ssh ssh = (Ssh) handle;
11830 return ssh->send_ok;
11833 static int ssh_ldisc(void *handle, int option)
11835 Ssh ssh = (Ssh) handle;
11836 if (option == LD_ECHO)
11837 return ssh->echoing;
11838 if (option == LD_EDIT)
11839 return ssh->editing;
11843 static void ssh_provide_ldisc(void *handle, void *ldisc)
11845 Ssh ssh = (Ssh) handle;
11846 ssh->ldisc = ldisc;
11849 static void ssh_provide_logctx(void *handle, void *logctx)
11851 Ssh ssh = (Ssh) handle;
11852 ssh->logctx = logctx;
11855 static int ssh_return_exitcode(void *handle)
11857 Ssh ssh = (Ssh) handle;
11858 if (ssh->s != NULL)
11861 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11865 * cfg_info for SSH is the protocol running in this session.
11866 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11867 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11869 static int ssh_cfg_info(void *handle)
11871 Ssh ssh = (Ssh) handle;
11872 if (ssh->version == 0)
11873 return 0; /* don't know yet */
11874 else if (ssh->bare_connection)
11877 return ssh->version;
11881 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11882 * that fails. This variable is the means by which scp.c can reach
11883 * into the SSH code and find out which one it got.
11885 extern int ssh_fallback_cmd(void *handle)
11887 Ssh ssh = (Ssh) handle;
11888 return ssh->fallback_cmd;
11891 Backend ssh_backend = {
11901 ssh_return_exitcode,
11905 ssh_provide_logctx,
11908 ssh_test_for_upstream,