29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
92 static const struct ssh_ttymode {
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "IUTF8", 42, TTY_OP_BOOL },
129 { "ISIG", 50, TTY_OP_BOOL },
130 { "ICANON", 51, TTY_OP_BOOL },
131 { "XCASE", 52, TTY_OP_BOOL },
132 { "ECHO", 53, TTY_OP_BOOL },
133 { "ECHOE", 54, TTY_OP_BOOL },
134 { "ECHOK", 55, TTY_OP_BOOL },
135 { "ECHONL", 56, TTY_OP_BOOL },
136 { "NOFLSH", 57, TTY_OP_BOOL },
137 { "TOSTOP", 58, TTY_OP_BOOL },
138 { "IEXTEN", 59, TTY_OP_BOOL },
139 { "ECHOCTL", 60, TTY_OP_BOOL },
140 { "ECHOKE", 61, TTY_OP_BOOL },
141 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
142 { "OPOST", 70, TTY_OP_BOOL },
143 { "OLCUC", 71, TTY_OP_BOOL },
144 { "ONLCR", 72, TTY_OP_BOOL },
145 { "OCRNL", 73, TTY_OP_BOOL },
146 { "ONOCR", 74, TTY_OP_BOOL },
147 { "ONLRET", 75, TTY_OP_BOOL },
148 { "CS7", 90, TTY_OP_BOOL },
149 { "CS8", 91, TTY_OP_BOOL },
150 { "PARENB", 92, TTY_OP_BOOL },
151 { "PARODD", 93, TTY_OP_BOOL }
154 /* Miscellaneous other tty-related constants. */
155 #define SSH_TTY_OP_END 0
156 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
157 #define SSH1_TTY_OP_ISPEED 192
158 #define SSH1_TTY_OP_OSPEED 193
159 #define SSH2_TTY_OP_ISPEED 128
160 #define SSH2_TTY_OP_OSPEED 129
162 /* Helper functions for parsing tty-related config. */
163 static unsigned int ssh_tty_parse_specchar(char *s)
168 ret = ctrlparse(s, &next);
169 if (!next) ret = s[0];
171 ret = 255; /* special value meaning "don't set" */
175 static unsigned int ssh_tty_parse_boolean(char *s)
177 if (stricmp(s, "yes") == 0 ||
178 stricmp(s, "on") == 0 ||
179 stricmp(s, "true") == 0 ||
180 stricmp(s, "+") == 0)
182 else if (stricmp(s, "no") == 0 ||
183 stricmp(s, "off") == 0 ||
184 stricmp(s, "false") == 0 ||
185 stricmp(s, "-") == 0)
186 return 0; /* false */
188 return (atoi(s) != 0);
191 #define translate(x) if (type == x) return #x
192 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
193 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
194 static const char *ssh1_pkt_type(int type)
196 translate(SSH1_MSG_DISCONNECT);
197 translate(SSH1_SMSG_PUBLIC_KEY);
198 translate(SSH1_CMSG_SESSION_KEY);
199 translate(SSH1_CMSG_USER);
200 translate(SSH1_CMSG_AUTH_RSA);
201 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
202 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
203 translate(SSH1_CMSG_AUTH_PASSWORD);
204 translate(SSH1_CMSG_REQUEST_PTY);
205 translate(SSH1_CMSG_WINDOW_SIZE);
206 translate(SSH1_CMSG_EXEC_SHELL);
207 translate(SSH1_CMSG_EXEC_CMD);
208 translate(SSH1_SMSG_SUCCESS);
209 translate(SSH1_SMSG_FAILURE);
210 translate(SSH1_CMSG_STDIN_DATA);
211 translate(SSH1_SMSG_STDOUT_DATA);
212 translate(SSH1_SMSG_STDERR_DATA);
213 translate(SSH1_CMSG_EOF);
214 translate(SSH1_SMSG_EXIT_STATUS);
215 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
216 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
217 translate(SSH1_MSG_CHANNEL_DATA);
218 translate(SSH1_MSG_CHANNEL_CLOSE);
219 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
220 translate(SSH1_SMSG_X11_OPEN);
221 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
222 translate(SSH1_MSG_PORT_OPEN);
223 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
224 translate(SSH1_SMSG_AGENT_OPEN);
225 translate(SSH1_MSG_IGNORE);
226 translate(SSH1_CMSG_EXIT_CONFIRMATION);
227 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
228 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
229 translate(SSH1_MSG_DEBUG);
230 translate(SSH1_CMSG_REQUEST_COMPRESSION);
231 translate(SSH1_CMSG_AUTH_TIS);
232 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
234 translate(SSH1_CMSG_AUTH_CCARD);
235 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
236 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
239 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
247 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
248 translate(SSH2_MSG_DISCONNECT);
249 translate(SSH2_MSG_IGNORE);
250 translate(SSH2_MSG_UNIMPLEMENTED);
251 translate(SSH2_MSG_DEBUG);
252 translate(SSH2_MSG_SERVICE_REQUEST);
253 translate(SSH2_MSG_SERVICE_ACCEPT);
254 translate(SSH2_MSG_KEXINIT);
255 translate(SSH2_MSG_NEWKEYS);
256 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
263 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
266 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
267 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
268 translate(SSH2_MSG_USERAUTH_REQUEST);
269 translate(SSH2_MSG_USERAUTH_FAILURE);
270 translate(SSH2_MSG_USERAUTH_SUCCESS);
271 translate(SSH2_MSG_USERAUTH_BANNER);
272 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
273 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
274 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
275 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
276 translate(SSH2_MSG_GLOBAL_REQUEST);
277 translate(SSH2_MSG_REQUEST_SUCCESS);
278 translate(SSH2_MSG_REQUEST_FAILURE);
279 translate(SSH2_MSG_CHANNEL_OPEN);
280 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
281 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
282 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
283 translate(SSH2_MSG_CHANNEL_DATA);
284 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
285 translate(SSH2_MSG_CHANNEL_EOF);
286 translate(SSH2_MSG_CHANNEL_CLOSE);
287 translate(SSH2_MSG_CHANNEL_REQUEST);
288 translate(SSH2_MSG_CHANNEL_SUCCESS);
289 translate(SSH2_MSG_CHANNEL_FAILURE);
295 /* Enumeration values for fields in SSH-1 packets */
297 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
301 * Coroutine mechanics for the sillier bits of the code. If these
302 * macros look impenetrable to you, you might find it helpful to
305 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
307 * which explains the theory behind these macros.
309 * In particular, if you are getting `case expression not constant'
310 * errors when building with MS Visual Studio, this is because MS's
311 * Edit and Continue debugging feature causes their compiler to
312 * violate ANSI C. To disable Edit and Continue debugging:
314 * - right-click ssh.c in the FileView
316 * - select the C/C++ tab and the General category
317 * - under `Debug info:', select anything _other_ than `Program
318 * Database for Edit and Continue'.
320 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
321 #define crBeginState crBegin(s->crLine)
322 #define crStateP(t, v) \
324 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
326 #define crState(t) crStateP(t, ssh->t)
327 #define crFinish(z) } *crLine = 0; return (z); }
328 #define crFinishV } *crLine = 0; return; }
329 #define crFinishFree(z) } sfree(s); return (z); }
330 #define crFinishFreeV } sfree(s); return; }
331 #define crReturn(z) \
333 *crLine =__LINE__; return (z); case __LINE__:;\
337 *crLine=__LINE__; return; case __LINE__:;\
339 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
340 #define crStopV do{ *crLine = 0; return; }while(0)
341 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
342 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
346 static struct Packet *ssh1_pkt_init(int pkt_type);
347 static struct Packet *ssh2_pkt_init(int pkt_type);
348 static void ssh_pkt_ensure(struct Packet *, int length);
349 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
350 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
351 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
352 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
353 static void ssh_pkt_addstring_start(struct Packet *);
354 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
355 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
356 static void ssh_pkt_addstring(struct Packet *, const char *data);
357 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
358 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
359 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
360 static int ssh2_pkt_construct(Ssh, struct Packet *);
361 static void ssh2_pkt_send(Ssh, struct Packet *);
362 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
363 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
366 struct Packet *pktin);
367 static void ssh_channel_init(struct ssh_channel *c);
368 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin);
369 static void ssh2_channel_check_close(struct ssh_channel *c);
370 static void ssh_channel_destroy(struct ssh_channel *c);
371 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize);
372 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
375 * Buffer management constants. There are several of these for
376 * various different purposes:
378 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
379 * on a local data stream before we throttle the whole SSH
380 * connection (in SSH-1 only). Throttling the whole connection is
381 * pretty drastic so we set this high in the hope it won't
384 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
385 * on the SSH connection itself before we defensively throttle
386 * _all_ local data streams. This is pretty drastic too (though
387 * thankfully unlikely in SSH-2 since the window mechanism should
388 * ensure that the server never has any need to throttle its end
389 * of the connection), so we set this high as well.
391 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
394 * - OUR_V2_BIGWIN is the window size we advertise for the only
395 * channel in a simple connection. It must be <= INT_MAX.
397 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
398 * to the remote side. This actually has nothing to do with the
399 * size of the _packet_, but is instead a limit on the amount
400 * of data we're willing to receive in a single SSH2 channel
403 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
404 * _packet_ we're prepared to cope with. It must be a multiple
405 * of the cipher block size, and must be at least 35000.
408 #define SSH1_BUFFER_LIMIT 32768
409 #define SSH_MAX_BACKLOG 32768
410 #define OUR_V2_WINSIZE 16384
411 #define OUR_V2_BIGWIN 0x7fffffff
412 #define OUR_V2_MAXPKT 0x4000UL
413 #define OUR_V2_PACKETLIMIT 0x9000UL
415 struct ssh_signkey_with_user_pref_id {
416 const struct ssh_signkey *alg;
419 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
420 { &ssh_ecdsa_ed25519, HK_ED25519 },
421 { &ssh_ecdsa_nistp256, HK_ECDSA },
422 { &ssh_ecdsa_nistp384, HK_ECDSA },
423 { &ssh_ecdsa_nistp521, HK_ECDSA },
424 { &ssh_dss, HK_DSA },
425 { &ssh_rsa, HK_RSA },
428 const static struct ssh_mac *const macs[] = {
429 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
431 const static struct ssh_mac *const buggymacs[] = {
432 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
435 static void *ssh_comp_none_init(void)
439 static void ssh_comp_none_cleanup(void *handle)
442 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
443 unsigned char **outblock, int *outlen)
447 static int ssh_comp_none_disable(void *handle)
451 const static struct ssh_compress ssh_comp_none = {
453 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
454 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
455 ssh_comp_none_disable, NULL
457 extern const struct ssh_compress ssh_zlib;
458 const static struct ssh_compress *const compressions[] = {
459 &ssh_zlib, &ssh_comp_none
462 enum { /* channel types */
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 static const char *ssh_pkt_type(Ssh ssh, int type)
990 if (ssh->version == 1)
991 return ssh1_pkt_type(type);
993 return ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, type);
996 #define logevent(s) logevent(ssh->frontend, s)
998 /* logevent, only printf-formatted. */
999 static void logeventf(Ssh ssh, const char *fmt, ...)
1005 buf = dupvprintf(fmt, ap);
1011 static void bomb_out(Ssh ssh, char *text)
1013 ssh_do_close(ssh, FALSE);
1015 connection_fatal(ssh->frontend, "%s", text);
1019 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1021 /* Helper function for common bits of parsing ttymodes. */
1022 static void parse_ttymodes(Ssh ssh,
1023 void (*do_mode)(void *data,
1024 const struct ssh_ttymode *mode,
1029 const struct ssh_ttymode *mode;
1031 char default_val[2];
1033 strcpy(default_val, "A");
1035 for (i = 0; i < lenof(ssh_ttymodes); i++) {
1036 mode = ssh_ttymodes + i;
1037 val = conf_get_str_str_opt(ssh->conf, CONF_ttymodes, mode->mode);
1042 * val[0] is either 'V', indicating that an explicit value
1043 * follows it, or 'A' indicating that we should pass the
1044 * value through from the local environment via get_ttymode.
1046 if (val[0] == 'A') {
1047 val = get_ttymode(ssh->frontend, mode->mode);
1049 do_mode(data, mode, val);
1053 do_mode(data, mode, val + 1); /* skip the 'V' */
1057 static int ssh_channelcmp(void *av, void *bv)
1059 struct ssh_channel *a = (struct ssh_channel *) av;
1060 struct ssh_channel *b = (struct ssh_channel *) bv;
1061 if (a->localid < b->localid)
1063 if (a->localid > b->localid)
1067 static int ssh_channelfind(void *av, void *bv)
1069 unsigned *a = (unsigned *) av;
1070 struct ssh_channel *b = (struct ssh_channel *) bv;
1071 if (*a < b->localid)
1073 if (*a > b->localid)
1078 static int ssh_rportcmp_ssh1(void *av, void *bv)
1080 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1081 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1083 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1084 return i < 0 ? -1 : +1;
1085 if (a->dport > b->dport)
1087 if (a->dport < b->dport)
1092 static int ssh_rportcmp_ssh2(void *av, void *bv)
1094 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1095 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1097 if ( (i = strcmp(a->shost, b->shost)) != 0)
1098 return i < 0 ? -1 : +1;
1099 if (a->sport > b->sport)
1101 if (a->sport < b->sport)
1107 * Special form of strcmp which can cope with NULL inputs. NULL is
1108 * defined to sort before even the empty string.
1110 static int nullstrcmp(const char *a, const char *b)
1112 if (a == NULL && b == NULL)
1118 return strcmp(a, b);
1121 static int ssh_portcmp(void *av, void *bv)
1123 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1124 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1126 if (a->type > b->type)
1128 if (a->type < b->type)
1130 if (a->addressfamily > b->addressfamily)
1132 if (a->addressfamily < b->addressfamily)
1134 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1135 return i < 0 ? -1 : +1;
1136 if (a->sport > b->sport)
1138 if (a->sport < b->sport)
1140 if (a->type != 'D') {
1141 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1142 return i < 0 ? -1 : +1;
1143 if (a->dport > b->dport)
1145 if (a->dport < b->dport)
1151 static int alloc_channel_id(Ssh ssh)
1153 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1154 unsigned low, high, mid;
1156 struct ssh_channel *c;
1159 * First-fit allocation of channel numbers: always pick the
1160 * lowest unused one. To do this, binary-search using the
1161 * counted B-tree to find the largest channel ID which is in a
1162 * contiguous sequence from the beginning. (Precisely
1163 * everything in that sequence must have ID equal to its tree
1164 * index plus CHANNEL_NUMBER_OFFSET.)
1166 tsize = count234(ssh->channels);
1170 while (high - low > 1) {
1171 mid = (high + low) / 2;
1172 c = index234(ssh->channels, mid);
1173 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1174 low = mid; /* this one is fine */
1176 high = mid; /* this one is past it */
1179 * Now low points to either -1, or the tree index of the
1180 * largest ID in the initial sequence.
1183 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1184 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1186 return low + 1 + CHANNEL_NUMBER_OFFSET;
1189 static void c_write_stderr(int trusted, const char *buf, int len)
1192 for (i = 0; i < len; i++)
1193 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1194 fputc(buf[i], stderr);
1197 static void c_write(Ssh ssh, const char *buf, int len)
1199 if (flags & FLAG_STDERR)
1200 c_write_stderr(1, buf, len);
1202 from_backend(ssh->frontend, 1, buf, len);
1205 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1207 if (flags & FLAG_STDERR)
1208 c_write_stderr(0, buf, len);
1210 from_backend_untrusted(ssh->frontend, buf, len);
1213 static void c_write_str(Ssh ssh, const char *buf)
1215 c_write(ssh, buf, strlen(buf));
1218 static void ssh_free_packet(struct Packet *pkt)
1223 static struct Packet *ssh_new_packet(void)
1225 struct Packet *pkt = snew(struct Packet);
1227 pkt->body = pkt->data = NULL;
1233 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1236 struct logblank_t blanks[4];
1242 if (ssh->logomitdata &&
1243 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1244 pkt->type == SSH1_SMSG_STDERR_DATA ||
1245 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1246 /* "Session data" packets - omit the data string. */
1247 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1248 ssh_pkt_getuint32(pkt); /* skip channel id */
1249 blanks[nblanks].offset = pkt->savedpos + 4;
1250 blanks[nblanks].type = PKTLOG_OMIT;
1251 ssh_pkt_getstring(pkt, &str, &slen);
1253 blanks[nblanks].len = slen;
1257 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1258 ssh1_pkt_type(pkt->type),
1259 pkt->body, pkt->length, nblanks, blanks, NULL,
1263 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1266 struct logblank_t blanks[4];
1271 * For outgoing packets, pkt->length represents the length of the
1272 * whole packet starting at pkt->data (including some header), and
1273 * pkt->body refers to the point within that where the log-worthy
1274 * payload begins. However, incoming packets expect pkt->length to
1275 * represent only the payload length (that is, it's measured from
1276 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1277 * packet to conform to the incoming-packet semantics, so that we
1278 * can analyse it with the ssh_pkt_get functions.
1280 pkt->length -= (pkt->body - pkt->data);
1283 if (ssh->logomitdata &&
1284 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1285 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1286 /* "Session data" packets - omit the data string. */
1287 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1288 ssh_pkt_getuint32(pkt); /* skip channel id */
1289 blanks[nblanks].offset = pkt->savedpos + 4;
1290 blanks[nblanks].type = PKTLOG_OMIT;
1291 ssh_pkt_getstring(pkt, &str, &slen);
1293 blanks[nblanks].len = slen;
1298 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1299 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1300 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1301 conf_get_int(ssh->conf, CONF_logomitpass)) {
1302 /* If this is a password or similar packet, blank the password(s). */
1303 blanks[nblanks].offset = 0;
1304 blanks[nblanks].len = pkt->length;
1305 blanks[nblanks].type = PKTLOG_BLANK;
1307 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1308 conf_get_int(ssh->conf, CONF_logomitpass)) {
1310 * If this is an X forwarding request packet, blank the fake
1313 * Note that while we blank the X authentication data here, we
1314 * don't take any special action to blank the start of an X11
1315 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1316 * an X connection without having session blanking enabled is
1317 * likely to leak your cookie into the log.
1320 ssh_pkt_getstring(pkt, &str, &slen);
1321 blanks[nblanks].offset = pkt->savedpos;
1322 blanks[nblanks].type = PKTLOG_BLANK;
1323 ssh_pkt_getstring(pkt, &str, &slen);
1325 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1330 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1331 ssh1_pkt_type(pkt->data[12]),
1332 pkt->body, pkt->length,
1333 nblanks, blanks, NULL, 0, NULL);
1336 * Undo the above adjustment of pkt->length, to put the packet
1337 * back in the state we found it.
1339 pkt->length += (pkt->body - pkt->data);
1343 * Collect incoming data in the incoming packet buffer.
1344 * Decipher and verify the packet when it is completely read.
1345 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1346 * Update the *data and *datalen variables.
1347 * Return a Packet structure when a packet is completed.
1349 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1352 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1354 crBegin(ssh->ssh1_rdpkt_crstate);
1356 st->pktin = ssh_new_packet();
1358 st->pktin->type = 0;
1359 st->pktin->length = 0;
1361 for (st->i = st->len = 0; st->i < 4; st->i++) {
1362 while ((*datalen) == 0)
1364 st->len = (st->len << 8) + **data;
1365 (*data)++, (*datalen)--;
1368 st->pad = 8 - (st->len % 8);
1369 st->biglen = st->len + st->pad;
1370 st->pktin->length = st->len - 5;
1372 if (st->biglen < 0) {
1373 bombout(("Extremely large packet length from server suggests"
1374 " data stream corruption"));
1375 ssh_free_packet(st->pktin);
1379 st->pktin->maxlen = st->biglen;
1380 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1382 st->to_read = st->biglen;
1383 st->p = st->pktin->data;
1384 while (st->to_read > 0) {
1385 st->chunk = st->to_read;
1386 while ((*datalen) == 0)
1388 if (st->chunk > (*datalen))
1389 st->chunk = (*datalen);
1390 memcpy(st->p, *data, st->chunk);
1392 *datalen -= st->chunk;
1394 st->to_read -= st->chunk;
1397 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1398 st->biglen, NULL)) {
1399 bombout(("Network attack (CRC compensation) detected!"));
1400 ssh_free_packet(st->pktin);
1405 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1407 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1408 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1409 if (st->gotcrc != st->realcrc) {
1410 bombout(("Incorrect CRC received on packet"));
1411 ssh_free_packet(st->pktin);
1415 st->pktin->body = st->pktin->data + st->pad + 1;
1417 if (ssh->v1_compressing) {
1418 unsigned char *decompblk;
1420 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1421 st->pktin->body - 1, st->pktin->length + 1,
1422 &decompblk, &decomplen)) {
1423 bombout(("Zlib decompression encountered invalid data"));
1424 ssh_free_packet(st->pktin);
1428 if (st->pktin->maxlen < st->pad + decomplen) {
1429 st->pktin->maxlen = st->pad + decomplen;
1430 st->pktin->data = sresize(st->pktin->data,
1431 st->pktin->maxlen + APIEXTRA,
1433 st->pktin->body = st->pktin->data + st->pad + 1;
1436 memcpy(st->pktin->body - 1, decompblk, decomplen);
1438 st->pktin->length = decomplen - 1;
1441 st->pktin->type = st->pktin->body[-1];
1444 * Now pktin->body and pktin->length identify the semantic content
1445 * of the packet, excluding the initial type byte.
1449 ssh1_log_incoming_packet(ssh, st->pktin);
1451 st->pktin->savedpos = 0;
1453 crFinish(st->pktin);
1456 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1459 struct logblank_t blanks[4];
1465 if (ssh->logomitdata &&
1466 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1467 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1468 /* "Session data" packets - omit the data string. */
1469 ssh_pkt_getuint32(pkt); /* skip channel id */
1470 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1471 ssh_pkt_getuint32(pkt); /* skip extended data type */
1472 blanks[nblanks].offset = pkt->savedpos + 4;
1473 blanks[nblanks].type = PKTLOG_OMIT;
1474 ssh_pkt_getstring(pkt, &str, &slen);
1476 blanks[nblanks].len = slen;
1481 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1482 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1483 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1487 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1490 struct logblank_t blanks[4];
1495 * For outgoing packets, pkt->length represents the length of the
1496 * whole packet starting at pkt->data (including some header), and
1497 * pkt->body refers to the point within that where the log-worthy
1498 * payload begins. However, incoming packets expect pkt->length to
1499 * represent only the payload length (that is, it's measured from
1500 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1501 * packet to conform to the incoming-packet semantics, so that we
1502 * can analyse it with the ssh_pkt_get functions.
1504 pkt->length -= (pkt->body - pkt->data);
1507 if (ssh->logomitdata &&
1508 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1509 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1510 /* "Session data" packets - omit the data string. */
1511 ssh_pkt_getuint32(pkt); /* skip channel id */
1512 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1513 ssh_pkt_getuint32(pkt); /* skip extended data type */
1514 blanks[nblanks].offset = pkt->savedpos + 4;
1515 blanks[nblanks].type = PKTLOG_OMIT;
1516 ssh_pkt_getstring(pkt, &str, &slen);
1518 blanks[nblanks].len = slen;
1523 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1524 conf_get_int(ssh->conf, CONF_logomitpass)) {
1525 /* If this is a password packet, blank the password(s). */
1527 ssh_pkt_getstring(pkt, &str, &slen);
1528 ssh_pkt_getstring(pkt, &str, &slen);
1529 ssh_pkt_getstring(pkt, &str, &slen);
1530 if (slen == 8 && !memcmp(str, "password", 8)) {
1531 ssh2_pkt_getbool(pkt);
1532 /* Blank the password field. */
1533 blanks[nblanks].offset = pkt->savedpos;
1534 blanks[nblanks].type = PKTLOG_BLANK;
1535 ssh_pkt_getstring(pkt, &str, &slen);
1537 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1539 /* If there's another password field beyond it (change of
1540 * password), blank that too. */
1541 ssh_pkt_getstring(pkt, &str, &slen);
1543 blanks[nblanks-1].len =
1544 pkt->savedpos - blanks[nblanks].offset;
1547 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1548 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1549 conf_get_int(ssh->conf, CONF_logomitpass)) {
1550 /* If this is a keyboard-interactive response packet, blank
1553 ssh_pkt_getuint32(pkt);
1554 blanks[nblanks].offset = pkt->savedpos;
1555 blanks[nblanks].type = PKTLOG_BLANK;
1557 ssh_pkt_getstring(pkt, &str, &slen);
1561 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1563 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1564 conf_get_int(ssh->conf, CONF_logomitpass)) {
1566 * If this is an X forwarding request packet, blank the fake
1569 * Note that while we blank the X authentication data here, we
1570 * don't take any special action to blank the start of an X11
1571 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1572 * an X connection without having session blanking enabled is
1573 * likely to leak your cookie into the log.
1576 ssh_pkt_getuint32(pkt);
1577 ssh_pkt_getstring(pkt, &str, &slen);
1578 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1579 ssh2_pkt_getbool(pkt);
1580 ssh2_pkt_getbool(pkt);
1581 ssh_pkt_getstring(pkt, &str, &slen);
1582 blanks[nblanks].offset = pkt->savedpos;
1583 blanks[nblanks].type = PKTLOG_BLANK;
1584 ssh_pkt_getstring(pkt, &str, &slen);
1586 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1592 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1593 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1594 pkt->body, pkt->length, nblanks, blanks,
1595 &ssh->v2_outgoing_sequence,
1596 pkt->downstream_id, pkt->additional_log_text);
1599 * Undo the above adjustment of pkt->length, to put the packet
1600 * back in the state we found it.
1602 pkt->length += (pkt->body - pkt->data);
1605 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1608 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1610 crBegin(ssh->ssh2_rdpkt_crstate);
1612 st->pktin = ssh_new_packet();
1614 st->pktin->type = 0;
1615 st->pktin->length = 0;
1617 st->cipherblk = ssh->sccipher->blksize;
1620 if (st->cipherblk < 8)
1622 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1624 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1625 ssh->scmac && !ssh->scmac_etm) {
1627 * When dealing with a CBC-mode cipher, we want to avoid the
1628 * possibility of an attacker's tweaking the ciphertext stream
1629 * so as to cause us to feed the same block to the block
1630 * cipher more than once and thus leak information
1631 * (VU#958563). The way we do this is not to take any
1632 * decisions on the basis of anything we've decrypted until
1633 * we've verified it with a MAC. That includes the packet
1634 * length, so we just read data and check the MAC repeatedly,
1635 * and when the MAC passes, see if the length we've got is
1638 * This defence is unnecessary in OpenSSH ETM mode, because
1639 * the whole point of ETM mode is that the attacker can't
1640 * tweak the ciphertext stream at all without the MAC
1641 * detecting it before we decrypt anything.
1644 /* May as well allocate the whole lot now. */
1645 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1648 /* Read an amount corresponding to the MAC. */
1649 for (st->i = 0; st->i < st->maclen; st->i++) {
1650 while ((*datalen) == 0)
1652 st->pktin->data[st->i] = *(*data)++;
1658 unsigned char seq[4];
1659 ssh->scmac->start(ssh->sc_mac_ctx);
1660 PUT_32BIT(seq, st->incoming_sequence);
1661 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1664 for (;;) { /* Once around this loop per cipher block. */
1665 /* Read another cipher-block's worth, and tack it onto the end. */
1666 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1667 while ((*datalen) == 0)
1669 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1672 /* Decrypt one more block (a little further back in the stream). */
1673 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1674 st->pktin->data + st->packetlen,
1676 /* Feed that block to the MAC. */
1677 ssh->scmac->bytes(ssh->sc_mac_ctx,
1678 st->pktin->data + st->packetlen, st->cipherblk);
1679 st->packetlen += st->cipherblk;
1680 /* See if that gives us a valid packet. */
1681 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1682 st->pktin->data + st->packetlen) &&
1683 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1686 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1687 bombout(("No valid incoming packet found"));
1688 ssh_free_packet(st->pktin);
1692 st->pktin->maxlen = st->packetlen + st->maclen;
1693 st->pktin->data = sresize(st->pktin->data,
1694 st->pktin->maxlen + APIEXTRA,
1696 } else if (ssh->scmac && ssh->scmac_etm) {
1697 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1700 * OpenSSH encrypt-then-MAC mode: the packet length is
1701 * unencrypted, unless the cipher supports length encryption.
1703 for (st->i = st->len = 0; st->i < 4; st->i++) {
1704 while ((*datalen) == 0)
1706 st->pktin->data[st->i] = *(*data)++;
1709 /* Cipher supports length decryption, so do it */
1710 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1711 /* Keep the packet the same though, so the MAC passes */
1712 unsigned char len[4];
1713 memcpy(len, st->pktin->data, 4);
1714 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1715 st->len = toint(GET_32BIT(len));
1717 st->len = toint(GET_32BIT(st->pktin->data));
1721 * _Completely_ silly lengths should be stomped on before they
1722 * do us any more damage.
1724 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1725 st->len % st->cipherblk != 0) {
1726 bombout(("Incoming packet length field was garbled"));
1727 ssh_free_packet(st->pktin);
1732 * So now we can work out the total packet length.
1734 st->packetlen = st->len + 4;
1737 * Allocate memory for the rest of the packet.
1739 st->pktin->maxlen = st->packetlen + st->maclen;
1740 st->pktin->data = sresize(st->pktin->data,
1741 st->pktin->maxlen + APIEXTRA,
1745 * Read the remainder of the packet.
1747 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1748 while ((*datalen) == 0)
1750 st->pktin->data[st->i] = *(*data)++;
1758 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1759 st->len + 4, st->incoming_sequence)) {
1760 bombout(("Incorrect MAC received on packet"));
1761 ssh_free_packet(st->pktin);
1765 /* Decrypt everything between the length field and the MAC. */
1767 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1768 st->pktin->data + 4,
1771 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1774 * Acquire and decrypt the first block of the packet. This will
1775 * contain the length and padding details.
1777 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1778 while ((*datalen) == 0)
1780 st->pktin->data[st->i] = *(*data)++;
1785 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1786 st->pktin->data, st->cipherblk);
1789 * Now get the length figure.
1791 st->len = toint(GET_32BIT(st->pktin->data));
1794 * _Completely_ silly lengths should be stomped on before they
1795 * do us any more damage.
1797 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1798 (st->len + 4) % st->cipherblk != 0) {
1799 bombout(("Incoming packet was garbled on decryption"));
1800 ssh_free_packet(st->pktin);
1805 * So now we can work out the total packet length.
1807 st->packetlen = st->len + 4;
1810 * Allocate memory for the rest of the packet.
1812 st->pktin->maxlen = st->packetlen + st->maclen;
1813 st->pktin->data = sresize(st->pktin->data,
1814 st->pktin->maxlen + APIEXTRA,
1818 * Read and decrypt the remainder of the packet.
1820 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1822 while ((*datalen) == 0)
1824 st->pktin->data[st->i] = *(*data)++;
1827 /* Decrypt everything _except_ the MAC. */
1829 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1830 st->pktin->data + st->cipherblk,
1831 st->packetlen - st->cipherblk);
1837 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1838 st->len + 4, st->incoming_sequence)) {
1839 bombout(("Incorrect MAC received on packet"));
1840 ssh_free_packet(st->pktin);
1844 /* Get and sanity-check the amount of random padding. */
1845 st->pad = st->pktin->data[4];
1846 if (st->pad < 4 || st->len - st->pad < 1) {
1847 bombout(("Invalid padding length on received packet"));
1848 ssh_free_packet(st->pktin);
1852 * This enables us to deduce the payload length.
1854 st->payload = st->len - st->pad - 1;
1856 st->pktin->length = st->payload + 5;
1857 st->pktin->encrypted_len = st->packetlen;
1859 st->pktin->sequence = st->incoming_sequence++;
1861 st->pktin->length = st->packetlen - st->pad;
1862 assert(st->pktin->length >= 0);
1865 * Decompress packet payload.
1868 unsigned char *newpayload;
1871 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1872 st->pktin->data + 5, st->pktin->length - 5,
1873 &newpayload, &newlen)) {
1874 if (st->pktin->maxlen < newlen + 5) {
1875 st->pktin->maxlen = newlen + 5;
1876 st->pktin->data = sresize(st->pktin->data,
1877 st->pktin->maxlen + APIEXTRA,
1880 st->pktin->length = 5 + newlen;
1881 memcpy(st->pktin->data + 5, newpayload, newlen);
1887 * RFC 4253 doesn't explicitly say that completely empty packets
1888 * with no type byte are forbidden, so treat them as deserving
1889 * an SSH_MSG_UNIMPLEMENTED.
1891 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1892 ssh2_msg_something_unimplemented(ssh, st->pktin);
1896 * pktin->body and pktin->length should identify the semantic
1897 * content of the packet, excluding the initial type byte.
1899 st->pktin->type = st->pktin->data[5];
1900 st->pktin->body = st->pktin->data + 6;
1901 st->pktin->length -= 6;
1902 assert(st->pktin->length >= 0); /* one last double-check */
1905 ssh2_log_incoming_packet(ssh, st->pktin);
1907 st->pktin->savedpos = 0;
1909 crFinish(st->pktin);
1912 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1913 const unsigned char **data,
1916 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1918 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1921 * Read the packet length field.
1923 for (st->i = 0; st->i < 4; st->i++) {
1924 while ((*datalen) == 0)
1926 st->length[st->i] = *(*data)++;
1930 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1931 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1932 bombout(("Invalid packet length received"));
1936 st->pktin = ssh_new_packet();
1937 st->pktin->data = snewn(st->packetlen, unsigned char);
1939 st->pktin->encrypted_len = st->packetlen;
1941 st->pktin->sequence = st->incoming_sequence++;
1944 * Read the remainder of the packet.
1946 for (st->i = 0; st->i < st->packetlen; st->i++) {
1947 while ((*datalen) == 0)
1949 st->pktin->data[st->i] = *(*data)++;
1954 * pktin->body and pktin->length should identify the semantic
1955 * content of the packet, excluding the initial type byte.
1957 st->pktin->type = st->pktin->data[0];
1958 st->pktin->body = st->pktin->data + 1;
1959 st->pktin->length = st->packetlen - 1;
1962 * Log incoming packet, possibly omitting sensitive fields.
1965 ssh2_log_incoming_packet(ssh, st->pktin);
1967 st->pktin->savedpos = 0;
1969 crFinish(st->pktin);
1972 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1974 int pad, biglen, i, pktoffs;
1978 * XXX various versions of SC (including 8.8.4) screw up the
1979 * register allocation in this function and use the same register
1980 * (D6) for len and as a temporary, with predictable results. The
1981 * following sledgehammer prevents this.
1988 ssh1_log_outgoing_packet(ssh, pkt);
1990 if (ssh->v1_compressing) {
1991 unsigned char *compblk;
1993 zlib_compress_block(ssh->cs_comp_ctx,
1994 pkt->data + 12, pkt->length - 12,
1995 &compblk, &complen);
1996 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1997 memcpy(pkt->data + 12, compblk, complen);
1999 pkt->length = complen + 12;
2002 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
2004 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
2005 pad = 8 - (len % 8);
2007 biglen = len + pad; /* len(padding+type+data+CRC) */
2009 for (i = pktoffs; i < 4+8; i++)
2010 pkt->data[i] = random_byte();
2011 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
2012 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
2013 PUT_32BIT(pkt->data + pktoffs, len);
2016 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
2017 pkt->data + pktoffs + 4, biglen);
2019 if (offset_p) *offset_p = pktoffs;
2020 return biglen + 4; /* len(length+padding+type+data+CRC) */
2023 static int s_write(Ssh ssh, void *data, int len)
2026 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
2027 0, NULL, NULL, 0, NULL);
2030 return sk_write(ssh->s, (char *)data, len);
2033 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2035 int len, backlog, offset;
2036 len = s_wrpkt_prepare(ssh, pkt, &offset);
2037 backlog = s_write(ssh, pkt->data + offset, len);
2038 if (backlog > SSH_MAX_BACKLOG)
2039 ssh_throttle_all(ssh, 1, backlog);
2040 ssh_free_packet(pkt);
2043 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2046 len = s_wrpkt_prepare(ssh, pkt, &offset);
2047 if (ssh->deferred_len + len > ssh->deferred_size) {
2048 ssh->deferred_size = ssh->deferred_len + len + 128;
2049 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2053 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2054 pkt->data + offset, len);
2055 ssh->deferred_len += len;
2056 ssh_free_packet(pkt);
2060 * Construct a SSH-1 packet with the specified contents.
2061 * (This all-at-once interface used to be the only one, but now SSH-1
2062 * packets can also be constructed incrementally.)
2064 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2070 pkt = ssh1_pkt_init(pkttype);
2072 while ((argtype = va_arg(ap, int)) != PKT_END) {
2073 unsigned char *argp, argchar;
2075 unsigned long argint;
2078 /* Actual fields in the packet */
2080 argint = va_arg(ap, int);
2081 ssh_pkt_adduint32(pkt, argint);
2084 argchar = (unsigned char) va_arg(ap, int);
2085 ssh_pkt_addbyte(pkt, argchar);
2088 argp = va_arg(ap, unsigned char *);
2089 arglen = va_arg(ap, int);
2090 ssh_pkt_adddata(pkt, argp, arglen);
2093 sargp = va_arg(ap, char *);
2094 ssh_pkt_addstring(pkt, sargp);
2097 bn = va_arg(ap, Bignum);
2098 ssh1_pkt_addmp(pkt, bn);
2106 static void send_packet(Ssh ssh, int pkttype, ...)
2110 va_start(ap, pkttype);
2111 pkt = construct_packet(ssh, pkttype, ap);
2116 static void defer_packet(Ssh ssh, int pkttype, ...)
2120 va_start(ap, pkttype);
2121 pkt = construct_packet(ssh, pkttype, ap);
2123 s_wrpkt_defer(ssh, pkt);
2126 static int ssh_versioncmp(const char *a, const char *b)
2129 unsigned long av, bv;
2131 av = strtoul(a, &ae, 10);
2132 bv = strtoul(b, &be, 10);
2134 return (av < bv ? -1 : +1);
2139 av = strtoul(ae, &ae, 10);
2140 bv = strtoul(be, &be, 10);
2142 return (av < bv ? -1 : +1);
2147 * Utility routines for putting an SSH-protocol `string' and
2148 * `uint32' into a hash state.
2150 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2152 unsigned char lenblk[4];
2153 PUT_32BIT(lenblk, len);
2154 h->bytes(s, lenblk, 4);
2155 h->bytes(s, str, len);
2158 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2160 unsigned char intblk[4];
2161 PUT_32BIT(intblk, i);
2162 h->bytes(s, intblk, 4);
2166 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2168 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2170 if (pkt->maxlen < length) {
2171 unsigned char *body = pkt->body;
2172 int offset = body ? body - pkt->data : 0;
2173 pkt->maxlen = length + 256;
2174 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2175 if (body) pkt->body = pkt->data + offset;
2178 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2181 ssh_pkt_ensure(pkt, pkt->length);
2182 memcpy(pkt->data + pkt->length - len, data, len);
2184 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2186 ssh_pkt_adddata(pkt, &byte, 1);
2188 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2190 ssh_pkt_adddata(pkt, &value, 1);
2192 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2195 PUT_32BIT(x, value);
2196 ssh_pkt_adddata(pkt, x, 4);
2198 static void ssh_pkt_addstring_start(struct Packet *pkt)
2200 ssh_pkt_adduint32(pkt, 0);
2201 pkt->savedpos = pkt->length;
2203 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2206 ssh_pkt_adddata(pkt, data, len);
2207 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2209 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2211 ssh_pkt_addstring_data(pkt, data, strlen(data));
2213 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2215 ssh_pkt_addstring_start(pkt);
2216 ssh_pkt_addstring_str(pkt, data);
2218 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2220 int len = ssh1_bignum_length(b);
2221 unsigned char *data = snewn(len, unsigned char);
2222 (void) ssh1_write_bignum(data, b);
2223 ssh_pkt_adddata(pkt, data, len);
2226 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2229 int i, n = (bignum_bitcount(b) + 7) / 8;
2230 p = snewn(n + 1, unsigned char);
2232 for (i = 1; i <= n; i++)
2233 p[i] = bignum_byte(b, n - i);
2235 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2237 memmove(p, p + i, n + 1 - i);
2241 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2245 p = ssh2_mpint_fmt(b, &len);
2246 ssh_pkt_addstring_start(pkt);
2247 ssh_pkt_addstring_data(pkt, (char *)p, len);
2251 static struct Packet *ssh1_pkt_init(int pkt_type)
2253 struct Packet *pkt = ssh_new_packet();
2254 pkt->length = 4 + 8; /* space for length + max padding */
2255 ssh_pkt_addbyte(pkt, pkt_type);
2256 pkt->body = pkt->data + pkt->length;
2257 pkt->type = pkt_type;
2258 pkt->downstream_id = 0;
2259 pkt->additional_log_text = NULL;
2263 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2264 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2265 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2266 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2267 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2268 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2269 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2270 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2271 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2273 static struct Packet *ssh2_pkt_init(int pkt_type)
2275 struct Packet *pkt = ssh_new_packet();
2276 pkt->length = 5; /* space for packet length + padding length */
2278 pkt->type = pkt_type;
2279 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2280 pkt->body = pkt->data + pkt->length; /* after packet type */
2281 pkt->downstream_id = 0;
2282 pkt->additional_log_text = NULL;
2287 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2288 * put the MAC on it. Final packet, ready to be sent, is stored in
2289 * pkt->data. Total length is returned.
2291 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2293 int cipherblk, maclen, padding, unencrypted_prefix, i;
2296 ssh2_log_outgoing_packet(ssh, pkt);
2298 if (ssh->bare_connection) {
2300 * Trivial packet construction for the bare connection
2303 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2304 pkt->body = pkt->data + 1;
2305 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2306 return pkt->length - 1;
2310 * Compress packet payload.
2313 unsigned char *newpayload;
2316 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2318 &newpayload, &newlen)) {
2320 ssh2_pkt_adddata(pkt, newpayload, newlen);
2326 * Add padding. At least four bytes, and must also bring total
2327 * length (minus MAC) up to a multiple of the block size.
2328 * If pkt->forcepad is set, make sure the packet is at least that size
2331 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2332 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2334 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2335 if (pkt->length + padding < pkt->forcepad)
2336 padding = pkt->forcepad - pkt->length;
2338 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2340 assert(padding <= 255);
2341 maclen = ssh->csmac ? ssh->csmac->len : 0;
2342 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2343 pkt->data[4] = padding;
2344 for (i = 0; i < padding; i++)
2345 pkt->data[pkt->length + i] = random_byte();
2346 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2348 /* Encrypt length if the scheme requires it */
2349 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2350 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2351 ssh->v2_outgoing_sequence);
2354 if (ssh->csmac && ssh->csmac_etm) {
2356 * OpenSSH-defined encrypt-then-MAC protocol.
2359 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2360 pkt->data + 4, pkt->length + padding - 4);
2361 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2362 pkt->length + padding,
2363 ssh->v2_outgoing_sequence);
2366 * SSH-2 standard protocol.
2369 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2370 pkt->length + padding,
2371 ssh->v2_outgoing_sequence);
2373 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2374 pkt->data, pkt->length + padding);
2377 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2378 pkt->encrypted_len = pkt->length + padding;
2380 /* Ready-to-send packet starts at pkt->data. We return length. */
2381 pkt->body = pkt->data;
2382 return pkt->length + padding + maclen;
2386 * Routines called from the main SSH code to send packets. There
2387 * are quite a few of these, because we have two separate
2388 * mechanisms for delaying the sending of packets:
2390 * - In order to send an IGNORE message and a password message in
2391 * a single fixed-length blob, we require the ability to
2392 * concatenate the encrypted forms of those two packets _into_ a
2393 * single blob and then pass it to our <network.h> transport
2394 * layer in one go. Hence, there's a deferment mechanism which
2395 * works after packet encryption.
2397 * - In order to avoid sending any connection-layer messages
2398 * during repeat key exchange, we have to queue up any such
2399 * outgoing messages _before_ they are encrypted (and in
2400 * particular before they're allocated sequence numbers), and
2401 * then send them once we've finished.
2403 * I call these mechanisms `defer' and `queue' respectively, so as
2404 * to distinguish them reasonably easily.
2406 * The functions send_noqueue() and defer_noqueue() free the packet
2407 * structure they are passed. Every outgoing packet goes through
2408 * precisely one of these functions in its life; packets passed to
2409 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2410 * these or get queued, and then when the queue is later emptied
2411 * the packets are all passed to defer_noqueue().
2413 * When using a CBC-mode cipher, it's necessary to ensure that an
2414 * attacker can't provide data to be encrypted using an IV that they
2415 * know. We ensure this by prefixing each packet that might contain
2416 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2417 * mechanism, so in this case send_noqueue() ends up redirecting to
2418 * defer_noqueue(). If you don't like this inefficiency, don't use
2422 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2423 static void ssh_pkt_defersend(Ssh);
2426 * Send an SSH-2 packet immediately, without queuing or deferring.
2428 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2432 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2433 /* We need to send two packets, so use the deferral mechanism. */
2434 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2435 ssh_pkt_defersend(ssh);
2438 len = ssh2_pkt_construct(ssh, pkt);
2439 backlog = s_write(ssh, pkt->body, len);
2440 if (backlog > SSH_MAX_BACKLOG)
2441 ssh_throttle_all(ssh, 1, backlog);
2443 ssh->outgoing_data_size += pkt->encrypted_len;
2444 if (!ssh->kex_in_progress &&
2445 !ssh->bare_connection &&
2446 ssh->max_data_size != 0 &&
2447 ssh->outgoing_data_size > ssh->max_data_size)
2448 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2450 ssh_free_packet(pkt);
2454 * Defer an SSH-2 packet.
2456 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2459 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2460 ssh->deferred_len == 0 && !noignore &&
2461 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2463 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2464 * get encrypted with a known IV.
2466 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2467 ssh2_pkt_addstring_start(ipkt);
2468 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2470 len = ssh2_pkt_construct(ssh, pkt);
2471 if (ssh->deferred_len + len > ssh->deferred_size) {
2472 ssh->deferred_size = ssh->deferred_len + len + 128;
2473 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2477 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2478 ssh->deferred_len += len;
2479 ssh->deferred_data_size += pkt->encrypted_len;
2480 ssh_free_packet(pkt);
2484 * Queue an SSH-2 packet.
2486 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2488 assert(ssh->queueing);
2490 if (ssh->queuelen >= ssh->queuesize) {
2491 ssh->queuesize = ssh->queuelen + 32;
2492 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2495 ssh->queue[ssh->queuelen++] = pkt;
2499 * Either queue or send a packet, depending on whether queueing is
2502 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2505 ssh2_pkt_queue(ssh, pkt);
2507 ssh2_pkt_send_noqueue(ssh, pkt);
2511 * Either queue or defer a packet, depending on whether queueing is
2514 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2517 ssh2_pkt_queue(ssh, pkt);
2519 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2523 * Send the whole deferred data block constructed by
2524 * ssh2_pkt_defer() or SSH-1's defer_packet().
2526 * The expected use of the defer mechanism is that you call
2527 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2528 * not currently queueing, this simply sets up deferred_send_data
2529 * and then sends it. If we _are_ currently queueing, the calls to
2530 * ssh2_pkt_defer() put the deferred packets on to the queue
2531 * instead, and therefore ssh_pkt_defersend() has no deferred data
2532 * to send. Hence, there's no need to make it conditional on
2535 static void ssh_pkt_defersend(Ssh ssh)
2538 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2539 ssh->deferred_len = ssh->deferred_size = 0;
2540 sfree(ssh->deferred_send_data);
2541 ssh->deferred_send_data = NULL;
2542 if (backlog > SSH_MAX_BACKLOG)
2543 ssh_throttle_all(ssh, 1, backlog);
2545 if (ssh->version == 2) {
2546 ssh->outgoing_data_size += ssh->deferred_data_size;
2547 ssh->deferred_data_size = 0;
2548 if (!ssh->kex_in_progress &&
2549 !ssh->bare_connection &&
2550 ssh->max_data_size != 0 &&
2551 ssh->outgoing_data_size > ssh->max_data_size)
2552 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2557 * Send a packet whose length needs to be disguised (typically
2558 * passwords or keyboard-interactive responses).
2560 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2566 * The simplest way to do this is to adjust the
2567 * variable-length padding field in the outgoing packet.
2569 * Currently compiled out, because some Cisco SSH servers
2570 * don't like excessively padded packets (bah, why's it
2573 pkt->forcepad = padsize;
2574 ssh2_pkt_send(ssh, pkt);
2579 * If we can't do that, however, an alternative approach is
2580 * to use the pkt_defer mechanism to bundle the packet
2581 * tightly together with an SSH_MSG_IGNORE such that their
2582 * combined length is a constant. So first we construct the
2583 * final form of this packet and defer its sending.
2585 ssh2_pkt_defer(ssh, pkt);
2588 * Now construct an SSH_MSG_IGNORE which includes a string
2589 * that's an exact multiple of the cipher block size. (If
2590 * the cipher is NULL so that the block size is
2591 * unavailable, we don't do this trick at all, because we
2592 * gain nothing by it.)
2594 if (ssh->cscipher &&
2595 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2598 stringlen = (256 - ssh->deferred_len);
2599 stringlen += ssh->cscipher->blksize - 1;
2600 stringlen -= (stringlen % ssh->cscipher->blksize);
2603 * Temporarily disable actual compression, so we
2604 * can guarantee to get this string exactly the
2605 * length we want it. The compression-disabling
2606 * routine should return an integer indicating how
2607 * many bytes we should adjust our string length
2611 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2613 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2614 ssh2_pkt_addstring_start(pkt);
2615 for (i = 0; i < stringlen; i++) {
2616 char c = (char) random_byte();
2617 ssh2_pkt_addstring_data(pkt, &c, 1);
2619 ssh2_pkt_defer(ssh, pkt);
2621 ssh_pkt_defersend(ssh);
2626 * Send all queued SSH-2 packets. We send them by means of
2627 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2628 * packets that needed to be lumped together.
2630 static void ssh2_pkt_queuesend(Ssh ssh)
2634 assert(!ssh->queueing);
2636 for (i = 0; i < ssh->queuelen; i++)
2637 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2640 ssh_pkt_defersend(ssh);
2644 void bndebug(char *string, Bignum b)
2648 p = ssh2_mpint_fmt(b, &len);
2649 debug(("%s", string));
2650 for (i = 0; i < len; i++)
2651 debug((" %02x", p[i]));
2657 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2661 p = ssh2_mpint_fmt(b, &len);
2662 hash_string(h, s, p, len);
2667 * Packet decode functions for both SSH-1 and SSH-2.
2669 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2671 unsigned long value;
2672 if (pkt->length - pkt->savedpos < 4)
2673 return 0; /* arrgh, no way to decline (FIXME?) */
2674 value = GET_32BIT(pkt->body + pkt->savedpos);
2678 static int ssh2_pkt_getbool(struct Packet *pkt)
2680 unsigned long value;
2681 if (pkt->length - pkt->savedpos < 1)
2682 return 0; /* arrgh, no way to decline (FIXME?) */
2683 value = pkt->body[pkt->savedpos] != 0;
2687 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2692 if (pkt->length - pkt->savedpos < 4)
2694 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2699 if (pkt->length - pkt->savedpos < *length)
2701 *p = (char *)(pkt->body + pkt->savedpos);
2702 pkt->savedpos += *length;
2704 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2706 if (pkt->length - pkt->savedpos < length)
2708 pkt->savedpos += length;
2709 return pkt->body + (pkt->savedpos - length);
2711 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2712 const unsigned char **keystr)
2716 j = makekey(pkt->body + pkt->savedpos,
2717 pkt->length - pkt->savedpos,
2724 assert(pkt->savedpos < pkt->length);
2728 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2733 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2734 pkt->length - pkt->savedpos, &b);
2742 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2748 ssh_pkt_getstring(pkt, &p, &length);
2753 b = bignum_from_bytes((unsigned char *)p, length);
2758 * Helper function to add an SSH-2 signature blob to a packet.
2759 * Expects to be shown the public key blob as well as the signature
2760 * blob. Normally works just like ssh2_pkt_addstring, but will
2761 * fiddle with the signature packet if necessary for
2762 * BUG_SSH2_RSA_PADDING.
2764 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2765 void *pkblob_v, int pkblob_len,
2766 void *sigblob_v, int sigblob_len)
2768 unsigned char *pkblob = (unsigned char *)pkblob_v;
2769 unsigned char *sigblob = (unsigned char *)sigblob_v;
2771 /* dmemdump(pkblob, pkblob_len); */
2772 /* dmemdump(sigblob, sigblob_len); */
2775 * See if this is in fact an ssh-rsa signature and a buggy
2776 * server; otherwise we can just do this the easy way.
2778 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2779 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2780 int pos, len, siglen;
2783 * Find the byte length of the modulus.
2786 pos = 4+7; /* skip over "ssh-rsa" */
2787 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2788 if (len < 0 || len > pkblob_len - pos - 4)
2790 pos += 4 + len; /* skip over exponent */
2791 if (pkblob_len - pos < 4)
2793 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2794 if (len < 0 || len > pkblob_len - pos - 4)
2796 pos += 4; /* find modulus itself */
2797 while (len > 0 && pkblob[pos] == 0)
2799 /* debug(("modulus length is %d\n", len)); */
2802 * Now find the signature integer.
2804 pos = 4+7; /* skip over "ssh-rsa" */
2805 if (sigblob_len < pos+4)
2807 siglen = toint(GET_32BIT(sigblob+pos));
2808 if (siglen != sigblob_len - pos - 4)
2810 /* debug(("signature length is %d\n", siglen)); */
2812 if (len != siglen) {
2813 unsigned char newlen[4];
2814 ssh2_pkt_addstring_start(pkt);
2815 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2816 /* dmemdump(sigblob, pos); */
2817 pos += 4; /* point to start of actual sig */
2818 PUT_32BIT(newlen, len);
2819 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2820 /* dmemdump(newlen, 4); */
2822 while (len-- > siglen) {
2823 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2824 /* dmemdump(newlen, 1); */
2826 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2827 /* dmemdump(sigblob+pos, siglen); */
2831 /* Otherwise fall through and do it the easy way. We also come
2832 * here as a fallback if we discover above that the key blob
2833 * is misformatted in some way. */
2837 ssh2_pkt_addstring_start(pkt);
2838 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2842 * Examine the remote side's version string and compare it against
2843 * a list of known buggy implementations.
2845 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2847 char *imp; /* pointer to implementation part */
2849 imp += strcspn(imp, "-");
2851 imp += strcspn(imp, "-");
2854 ssh->remote_bugs = 0;
2857 * General notes on server version strings:
2858 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2859 * here -- in particular, we've heard of one that's perfectly happy
2860 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2861 * so we can't distinguish them.
2863 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2864 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2865 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2866 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2867 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2868 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2870 * These versions don't support SSH1_MSG_IGNORE, so we have
2871 * to use a different defence against password length
2874 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2875 logevent("We believe remote version has SSH-1 ignore bug");
2878 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2879 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2880 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2882 * These versions need a plain password sent; they can't
2883 * handle having a null and a random length of data after
2886 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2887 logevent("We believe remote version needs a plain SSH-1 password");
2890 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2891 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2892 (!strcmp(imp, "Cisco-1.25")))) {
2894 * These versions apparently have no clue whatever about
2895 * RSA authentication and will panic and die if they see
2896 * an AUTH_RSA message.
2898 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2899 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2902 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2903 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2904 !wc_match("* VShell", imp) &&
2905 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2906 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2907 wc_match("2.1 *", imp)))) {
2909 * These versions have the HMAC bug.
2911 ssh->remote_bugs |= BUG_SSH2_HMAC;
2912 logevent("We believe remote version has SSH-2 HMAC bug");
2915 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2916 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2917 !wc_match("* VShell", imp) &&
2918 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2920 * These versions have the key-derivation bug (failing to
2921 * include the literal shared secret in the hashes that
2922 * generate the keys).
2924 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2925 logevent("We believe remote version has SSH-2 key-derivation bug");
2928 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2929 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2930 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2931 wc_match("OpenSSH_3.[0-2]*", imp) ||
2932 wc_match("mod_sftp/0.[0-8]*", imp) ||
2933 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2935 * These versions have the SSH-2 RSA padding bug.
2937 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2938 logevent("We believe remote version has SSH-2 RSA padding bug");
2941 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2942 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2943 wc_match("OpenSSH_2.[0-2]*", imp))) {
2945 * These versions have the SSH-2 session-ID bug in
2946 * public-key authentication.
2948 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2949 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2952 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2953 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2954 (wc_match("DigiSSH_2.0", imp) ||
2955 wc_match("OpenSSH_2.[0-4]*", imp) ||
2956 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2957 wc_match("Sun_SSH_1.0", imp) ||
2958 wc_match("Sun_SSH_1.0.1", imp) ||
2959 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2960 wc_match("WeOnlyDo-*", imp)))) {
2962 * These versions have the SSH-2 rekey bug.
2964 ssh->remote_bugs |= BUG_SSH2_REKEY;
2965 logevent("We believe remote version has SSH-2 rekey bug");
2968 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2969 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2970 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2971 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2973 * This version ignores our makpkt and needs to be throttled.
2975 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2976 logevent("We believe remote version ignores SSH-2 maximum packet size");
2979 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2981 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2982 * none detected automatically.
2984 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2985 logevent("We believe remote version has SSH-2 ignore bug");
2988 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2989 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2990 (wc_match("OpenSSH_2.[235]*", imp)))) {
2992 * These versions only support the original (pre-RFC4419)
2993 * SSH-2 GEX request, and disconnect with a protocol error if
2994 * we use the newer version.
2996 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2997 logevent("We believe remote version has outdated SSH-2 GEX");
3000 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
3002 * Servers that don't support our winadj request for one
3003 * reason or another. Currently, none detected automatically.
3005 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
3006 logevent("We believe remote version has winadj bug");
3009 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
3010 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
3011 (wc_match("OpenSSH_[2-5].*", imp) ||
3012 wc_match("OpenSSH_6.[0-6]*", imp) ||
3013 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
3014 wc_match("dropbear_0.5[01]*", imp)))) {
3016 * These versions have the SSH-2 channel request bug.
3017 * OpenSSH 6.7 and above do not:
3018 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
3019 * dropbear_0.52 and above do not:
3020 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
3022 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
3023 logevent("We believe remote version has SSH-2 channel request bug");
3028 * The `software version' part of an SSH version string is required
3029 * to contain no spaces or minus signs.
3031 static void ssh_fix_verstring(char *str)
3033 /* Eat "<protoversion>-". */
3034 while (*str && *str != '-') str++;
3035 assert(*str == '-'); str++;
3037 /* Convert minus signs and spaces in the remaining string into
3040 if (*str == '-' || *str == ' ')
3047 * Send an appropriate SSH version string.
3049 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3053 if (ssh->version == 2) {
3055 * Construct a v2 version string.
3057 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3060 * Construct a v1 version string.
3062 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3063 verstring = dupprintf("SSH-%s-%s\012",
3064 (ssh_versioncmp(svers, "1.5") <= 0 ?
3069 ssh_fix_verstring(verstring + strlen(protoname));
3071 /* FUZZING make PuTTY insecure, so make live use difficult. */
3075 if (ssh->version == 2) {
3078 * Record our version string.
3080 len = strcspn(verstring, "\015\012");
3081 ssh->v_c = snewn(len + 1, char);
3082 memcpy(ssh->v_c, verstring, len);
3086 logeventf(ssh, "We claim version: %.*s",
3087 strcspn(verstring, "\015\012"), verstring);
3088 s_write(ssh, verstring, strlen(verstring));
3092 static int do_ssh_init(Ssh ssh, unsigned char c)
3094 static const char protoname[] = "SSH-";
3096 struct do_ssh_init_state {
3105 crState(do_ssh_init_state);
3109 /* Search for a line beginning with the protocol name prefix in
3112 for (s->i = 0; protoname[s->i]; s->i++) {
3113 if ((char)c != protoname[s->i]) goto no;
3123 ssh->session_started = TRUE;
3125 s->vstrsize = sizeof(protoname) + 16;
3126 s->vstring = snewn(s->vstrsize, char);
3127 strcpy(s->vstring, protoname);
3128 s->vslen = strlen(protoname);
3131 if (s->vslen >= s->vstrsize - 1) {
3133 s->vstring = sresize(s->vstring, s->vstrsize, char);
3135 s->vstring[s->vslen++] = c;
3138 s->version[s->i] = '\0';
3140 } else if (s->i < sizeof(s->version) - 1)
3141 s->version[s->i++] = c;
3142 } else if (c == '\012')
3144 crReturn(1); /* get another char */
3147 ssh->agentfwd_enabled = FALSE;
3148 ssh->rdpkt2_state.incoming_sequence = 0;
3150 s->vstring[s->vslen] = 0;
3151 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3152 logeventf(ssh, "Server version: %s", s->vstring);
3153 ssh_detect_bugs(ssh, s->vstring);
3156 * Decide which SSH protocol version to support.
3159 /* Anything strictly below "2.0" means protocol 1 is supported. */
3160 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3161 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3162 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3164 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3166 bombout(("SSH protocol version 1 required by our configuration "
3167 "but not provided by server"));
3170 } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) {
3172 bombout(("SSH protocol version 2 required by our configuration "
3173 "but server only provides (old, insecure) SSH-1"));
3177 /* No longer support values 1 or 2 for CONF_sshprot */
3178 assert(!"Unexpected value for CONF_sshprot");
3181 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3186 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3188 /* Send the version string, if we haven't already */
3189 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3190 ssh_send_verstring(ssh, protoname, s->version);
3192 if (ssh->version == 2) {
3195 * Record their version string.
3197 len = strcspn(s->vstring, "\015\012");
3198 ssh->v_s = snewn(len + 1, char);
3199 memcpy(ssh->v_s, s->vstring, len);
3203 * Initialise SSH-2 protocol.
3205 ssh->protocol = ssh2_protocol;
3206 ssh2_protocol_setup(ssh);
3207 ssh->s_rdpkt = ssh2_rdpkt;
3210 * Initialise SSH-1 protocol.
3212 ssh->protocol = ssh1_protocol;
3213 ssh1_protocol_setup(ssh);
3214 ssh->s_rdpkt = ssh1_rdpkt;
3216 if (ssh->version == 2)
3217 do_ssh2_transport(ssh, NULL, -1, NULL);
3219 update_specials_menu(ssh->frontend);
3220 ssh->state = SSH_STATE_BEFORE_SIZE;
3221 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3228 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3231 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3232 * the ssh-connection part, extracted and given a trivial binary
3233 * packet protocol, so we replace 'SSH-' at the start with a new
3234 * name. In proper SSH style (though of course this part of the
3235 * proper SSH protocol _isn't_ subject to this kind of
3236 * DNS-domain-based extension), we define the new name in our
3239 static const char protoname[] =
3240 "SSHCONNECTION@putty.projects.tartarus.org-";
3242 struct do_ssh_connection_init_state {
3250 crState(do_ssh_connection_init_state);
3254 /* Search for a line beginning with the protocol name prefix in
3257 for (s->i = 0; protoname[s->i]; s->i++) {
3258 if ((char)c != protoname[s->i]) goto no;
3268 s->vstrsize = sizeof(protoname) + 16;
3269 s->vstring = snewn(s->vstrsize, char);
3270 strcpy(s->vstring, protoname);
3271 s->vslen = strlen(protoname);
3274 if (s->vslen >= s->vstrsize - 1) {
3276 s->vstring = sresize(s->vstring, s->vstrsize, char);
3278 s->vstring[s->vslen++] = c;
3281 s->version[s->i] = '\0';
3283 } else if (s->i < sizeof(s->version) - 1)
3284 s->version[s->i++] = c;
3285 } else if (c == '\012')
3287 crReturn(1); /* get another char */
3290 ssh->agentfwd_enabled = FALSE;
3291 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3293 s->vstring[s->vslen] = 0;
3294 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3295 logeventf(ssh, "Server version: %s", s->vstring);
3296 ssh_detect_bugs(ssh, s->vstring);
3299 * Decide which SSH protocol version to support. This is easy in
3300 * bare ssh-connection mode: only 2.0 is legal.
3302 if (ssh_versioncmp(s->version, "2.0") < 0) {
3303 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3306 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3307 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3313 logeventf(ssh, "Using bare ssh-connection protocol");
3315 /* Send the version string, if we haven't already */
3316 ssh_send_verstring(ssh, protoname, s->version);
3319 * Initialise bare connection protocol.
3321 ssh->protocol = ssh2_bare_connection_protocol;
3322 ssh2_bare_connection_protocol_setup(ssh);
3323 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3325 update_specials_menu(ssh->frontend);
3326 ssh->state = SSH_STATE_BEFORE_SIZE;
3327 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3330 * Get authconn (really just conn) under way.
3332 do_ssh2_authconn(ssh, NULL, 0, NULL);
3339 static void ssh_process_incoming_data(Ssh ssh,
3340 const unsigned char **data, int *datalen)
3342 struct Packet *pktin;
3344 pktin = ssh->s_rdpkt(ssh, data, datalen);
3346 ssh->protocol(ssh, NULL, 0, pktin);
3347 ssh_free_packet(pktin);
3351 static void ssh_queue_incoming_data(Ssh ssh,
3352 const unsigned char **data, int *datalen)
3354 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3359 static void ssh_process_queued_incoming_data(Ssh ssh)
3362 const unsigned char *data;
3365 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3366 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3370 while (!ssh->frozen && len > 0)
3371 ssh_process_incoming_data(ssh, &data, &len);
3374 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3378 static void ssh_set_frozen(Ssh ssh, int frozen)
3381 sk_set_frozen(ssh->s, frozen);
3382 ssh->frozen = frozen;
3385 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3387 /* Log raw data, if we're in that mode. */
3389 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3390 0, NULL, NULL, 0, NULL);
3392 crBegin(ssh->ssh_gotdata_crstate);
3395 * To begin with, feed the characters one by one to the
3396 * protocol initialisation / selection function do_ssh_init().
3397 * When that returns 0, we're done with the initial greeting
3398 * exchange and can move on to packet discipline.
3401 int ret; /* need not be kept across crReturn */
3403 crReturnV; /* more data please */
3404 ret = ssh->do_ssh_init(ssh, *data);
3412 * We emerge from that loop when the initial negotiation is
3413 * over and we have selected an s_rdpkt function. Now pass
3414 * everything to s_rdpkt, and then pass the resulting packets
3415 * to the proper protocol handler.
3419 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3421 ssh_queue_incoming_data(ssh, &data, &datalen);
3422 /* This uses up all data and cannot cause anything interesting
3423 * to happen; indeed, for anything to happen at all, we must
3424 * return, so break out. */
3426 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3427 /* This uses up some or all data, and may freeze the
3429 ssh_process_queued_incoming_data(ssh);
3431 /* This uses up some or all data, and may freeze the
3433 ssh_process_incoming_data(ssh, &data, &datalen);
3435 /* FIXME this is probably EBW. */
3436 if (ssh->state == SSH_STATE_CLOSED)
3439 /* We're out of data. Go and get some more. */
3445 static int ssh_do_close(Ssh ssh, int notify_exit)
3448 struct ssh_channel *c;
3450 ssh->state = SSH_STATE_CLOSED;
3451 expire_timer_context(ssh);
3456 notify_remote_exit(ssh->frontend);
3461 * Now we must shut down any port- and X-forwarded channels going
3462 * through this connection.
3464 if (ssh->channels) {
3465 while (NULL != (c = index234(ssh->channels, 0))) {
3468 x11_close(c->u.x11.xconn);
3471 pfd_close(c->u.pfd.pf);
3474 del234(ssh->channels, c); /* moving next one to index 0 */
3475 if (ssh->version == 2)
3476 bufchain_clear(&c->v.v2.outbuffer);
3481 * Go through port-forwardings, and close any associated
3482 * listening sockets.
3484 if (ssh->portfwds) {
3485 struct ssh_portfwd *pf;
3486 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3487 /* Dispose of any listening socket. */
3489 pfl_terminate(pf->local);
3490 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3493 freetree234(ssh->portfwds);
3494 ssh->portfwds = NULL;
3498 * Also stop attempting to connection-share.
3500 if (ssh->connshare) {
3501 sharestate_free(ssh->connshare);
3502 ssh->connshare = NULL;
3508 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3509 const char *error_msg, int error_code)
3511 Ssh ssh = (Ssh) plug;
3514 * While we're attempting connection sharing, don't loudly log
3515 * everything that happens. Real TCP connections need to be logged
3516 * when we _start_ trying to connect, because it might be ages
3517 * before they respond if something goes wrong; but connection
3518 * sharing is local and quick to respond, and it's sufficient to
3519 * simply wait and see whether it worked afterwards.
3522 if (!ssh->attempting_connshare)
3523 backend_socket_log(ssh->frontend, type, addr, port,
3524 error_msg, error_code, ssh->conf,
3525 ssh->session_started);
3528 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3529 const char *ds_err, const char *us_err)
3531 if (event == SHARE_NONE) {
3532 /* In this case, 'logtext' is an error message indicating a
3533 * reason why connection sharing couldn't be set up _at all_.
3534 * Failing that, ds_err and us_err indicate why we couldn't be
3535 * a downstream and an upstream respectively. */
3537 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3540 logeventf(ssh, "Could not set up connection sharing"
3541 " as downstream: %s", ds_err);
3543 logeventf(ssh, "Could not set up connection sharing"
3544 " as upstream: %s", us_err);
3546 } else if (event == SHARE_DOWNSTREAM) {
3547 /* In this case, 'logtext' is a local endpoint address */
3548 logeventf(ssh, "Using existing shared connection at %s", logtext);
3549 /* Also we should mention this in the console window to avoid
3550 * confusing users as to why this window doesn't behave the
3552 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3553 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3555 } else if (event == SHARE_UPSTREAM) {
3556 /* In this case, 'logtext' is a local endpoint address too */
3557 logeventf(ssh, "Sharing this connection at %s", logtext);
3561 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3564 Ssh ssh = (Ssh) plug;
3565 int need_notify = ssh_do_close(ssh, FALSE);
3568 if (!ssh->close_expected)
3569 error_msg = "Server unexpectedly closed network connection";
3571 error_msg = "Server closed network connection";
3574 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3578 notify_remote_exit(ssh->frontend);
3581 logevent(error_msg);
3582 if (!ssh->close_expected || !ssh->clean_exit)
3583 connection_fatal(ssh->frontend, "%s", error_msg);
3587 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3589 Ssh ssh = (Ssh) plug;
3590 ssh_gotdata(ssh, (unsigned char *)data, len);
3591 if (ssh->state == SSH_STATE_CLOSED) {
3592 ssh_do_close(ssh, TRUE);
3598 static void ssh_sent(Plug plug, int bufsize)
3600 Ssh ssh = (Ssh) plug;
3602 * If the send backlog on the SSH socket itself clears, we
3603 * should unthrottle the whole world if it was throttled.
3605 if (bufsize < SSH_MAX_BACKLOG)
3606 ssh_throttle_all(ssh, 0, bufsize);
3609 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3610 char **savedhost, int *savedport,
3613 char *loghost = conf_get_str(conf, CONF_loghost);
3615 *loghost_ret = loghost;
3621 tmphost = dupstr(loghost);
3622 *savedport = 22; /* default ssh port */
3625 * A colon suffix on the hostname string also lets us affect
3626 * savedport. (Unless there are multiple colons, in which case
3627 * we assume this is an unbracketed IPv6 literal.)
3629 colon = host_strrchr(tmphost, ':');
3630 if (colon && colon == host_strchr(tmphost, ':')) {
3633 *savedport = atoi(colon);
3636 *savedhost = host_strduptrim(tmphost);
3639 *savedhost = host_strduptrim(host);
3641 port = 22; /* default ssh port */
3646 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3652 random_ref(); /* platform may need this to determine share socket name */
3653 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3654 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3662 * Connect to specified host and port.
3663 * Returns an error message, or NULL on success.
3664 * Also places the canonical host name into `realhost'. It must be
3665 * freed by the caller.
3667 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3668 char **realhost, int nodelay, int keepalive)
3670 static const struct plug_function_table fn_table = {
3681 int addressfamily, sshprot;
3683 ssh_hostport_setup(host, port, ssh->conf,
3684 &ssh->savedhost, &ssh->savedport, &loghost);
3686 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3689 * Try connection-sharing, in case that means we don't open a
3690 * socket after all. ssh_connection_sharing_init will connect to a
3691 * previously established upstream if it can, and failing that,
3692 * establish a listening socket for _us_ to be the upstream. In
3693 * the latter case it will return NULL just as if it had done
3694 * nothing, because here we only need to care if we're a
3695 * downstream and need to do our connection setup differently.
3697 ssh->connshare = NULL;
3698 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3699 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3700 ssh->conf, ssh, &ssh->connshare);
3701 ssh->attempting_connshare = FALSE;
3702 if (ssh->s != NULL) {
3704 * We are a downstream.
3706 ssh->bare_connection = TRUE;
3707 ssh->do_ssh_init = do_ssh_connection_init;
3708 ssh->fullhostname = NULL;
3709 *realhost = dupstr(host); /* best we can do */
3712 * We're not a downstream, so open a normal socket.
3714 ssh->do_ssh_init = do_ssh_init;
3719 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3720 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3721 ssh->frontend, "SSH connection");
3722 if ((err = sk_addr_error(addr)) != NULL) {
3726 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3728 ssh->s = new_connection(addr, *realhost, port,
3729 0, 1, nodelay, keepalive,
3730 (Plug) ssh, ssh->conf);
3731 if ((err = sk_socket_error(ssh->s)) != NULL) {
3733 notify_remote_exit(ssh->frontend);
3739 * The SSH version number is always fixed (since we no longer support
3740 * fallback between versions), so set it now, and if it's SSH-2,
3741 * send the version string now too.
3743 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3744 assert(sshprot == 0 || sshprot == 3);
3748 if (sshprot == 3 && !ssh->bare_connection) {
3751 ssh_send_verstring(ssh, "SSH-", NULL);
3755 * loghost, if configured, overrides realhost.
3759 *realhost = dupstr(loghost);
3766 * Throttle or unthrottle the SSH connection.
3768 static void ssh_throttle_conn(Ssh ssh, int adjust)
3770 int old_count = ssh->conn_throttle_count;
3771 ssh->conn_throttle_count += adjust;
3772 assert(ssh->conn_throttle_count >= 0);
3773 if (ssh->conn_throttle_count && !old_count) {
3774 ssh_set_frozen(ssh, 1);
3775 } else if (!ssh->conn_throttle_count && old_count) {
3776 ssh_set_frozen(ssh, 0);
3781 * Throttle or unthrottle _all_ local data streams (for when sends
3782 * on the SSH connection itself back up).
3784 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3787 struct ssh_channel *c;
3789 if (enable == ssh->throttled_all)
3791 ssh->throttled_all = enable;
3792 ssh->overall_bufsize = bufsize;
3795 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3797 case CHAN_MAINSESSION:
3799 * This is treated separately, outside the switch.
3803 x11_override_throttle(c->u.x11.xconn, enable);
3806 /* Agent channels require no buffer management. */
3809 pfd_override_throttle(c->u.pfd.pf, enable);
3815 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3817 Ssh ssh = (Ssh) sshv;
3819 ssh->agent_response = reply;
3820 ssh->agent_response_len = replylen;
3822 if (ssh->version == 1)
3823 do_ssh1_login(ssh, NULL, -1, NULL);
3825 do_ssh2_authconn(ssh, NULL, -1, NULL);
3828 static void ssh_dialog_callback(void *sshv, int ret)
3830 Ssh ssh = (Ssh) sshv;
3832 ssh->user_response = ret;
3834 if (ssh->version == 1)
3835 do_ssh1_login(ssh, NULL, -1, NULL);
3837 do_ssh2_transport(ssh, NULL, -1, NULL);
3840 * This may have unfrozen the SSH connection, so do a
3843 ssh_process_queued_incoming_data(ssh);
3846 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3848 struct ssh_channel *c = (struct ssh_channel *)cv;
3849 const void *sentreply = reply;
3851 c->u.a.outstanding_requests--;
3853 /* Fake SSH_AGENT_FAILURE. */
3854 sentreply = "\0\0\0\1\5";
3857 ssh_send_channel_data(c, sentreply, replylen);
3861 * If we've already seen an incoming EOF but haven't sent an
3862 * outgoing one, this may be the moment to send it.
3864 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3865 sshfwd_write_eof(c);
3869 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3870 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3871 * => log `wire_reason'.
3873 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3874 const char *wire_reason,
3875 int code, int clean_exit)
3879 client_reason = wire_reason;
3881 error = dupprintf("Disconnected: %s", client_reason);
3883 error = dupstr("Disconnected");
3885 if (ssh->version == 1) {
3886 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3888 } else if (ssh->version == 2) {
3889 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3890 ssh2_pkt_adduint32(pktout, code);
3891 ssh2_pkt_addstring(pktout, wire_reason);
3892 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3893 ssh2_pkt_send_noqueue(ssh, pktout);
3896 ssh->close_expected = TRUE;
3897 ssh->clean_exit = clean_exit;
3898 ssh_closing((Plug)ssh, error, 0, 0);
3902 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3903 const struct ssh_signkey *ssh2keytype,
3906 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3907 return -1; /* no manual keys configured */
3912 * The fingerprint string we've been given will have things
3913 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3914 * narrow down to just the colon-separated hex block at the
3915 * end of the string.
3917 const char *p = strrchr(fingerprint, ' ');
3918 fingerprint = p ? p+1 : fingerprint;
3919 /* Quick sanity checks, including making sure it's in lowercase */
3920 assert(strlen(fingerprint) == 16*3 - 1);
3921 assert(fingerprint[2] == ':');
3922 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3924 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3926 return 1; /* success */
3931 * Construct the base64-encoded public key blob and see if
3934 unsigned char *binblob;
3936 int binlen, atoms, i;
3937 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3938 atoms = (binlen + 2) / 3;
3939 base64blob = snewn(atoms * 4 + 1, char);
3940 for (i = 0; i < atoms; i++)
3941 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3942 base64blob[atoms * 4] = '\0';
3944 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3947 return 1; /* success */
3956 * Handle the key exchange and user authentication phases.
3958 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3959 struct Packet *pktin)
3962 unsigned char cookie[8], *ptr;
3963 struct MD5Context md5c;
3964 struct do_ssh1_login_state {
3967 unsigned char *rsabuf;
3968 const unsigned char *keystr1, *keystr2;
3969 unsigned long supported_ciphers_mask, supported_auths_mask;
3970 int tried_publickey, tried_agent;
3971 int tis_auth_refused, ccard_auth_refused;
3972 unsigned char session_id[16];
3974 void *publickey_blob;
3975 int publickey_bloblen;
3976 char *publickey_comment;
3977 int privatekey_available, privatekey_encrypted;
3978 prompts_t *cur_prompt;
3981 unsigned char request[5], *response, *p;
3991 struct RSAKey servkey, hostkey;
3993 crState(do_ssh1_login_state);
4000 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
4001 bombout(("Public key packet not received"));
4005 logevent("Received public keys");
4007 ptr = ssh_pkt_getdata(pktin, 8);
4009 bombout(("SSH-1 public key packet stopped before random cookie"));
4012 memcpy(cookie, ptr, 8);
4014 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
4015 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
4016 bombout(("Failed to read SSH-1 public keys from public key packet"));
4021 * Log the host key fingerprint.
4025 logevent("Host key fingerprint is:");
4026 strcpy(logmsg, " ");
4027 s->hostkey.comment = NULL;
4028 rsa_fingerprint(logmsg + strlen(logmsg),
4029 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4033 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4034 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4035 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4036 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4037 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4039 ssh->v1_local_protoflags =
4040 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4041 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4044 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4045 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4046 MD5Update(&md5c, cookie, 8);
4047 MD5Final(s->session_id, &md5c);
4049 for (i = 0; i < 32; i++)
4050 ssh->session_key[i] = random_byte();
4053 * Verify that the `bits' and `bytes' parameters match.
4055 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4056 s->servkey.bits > s->servkey.bytes * 8) {
4057 bombout(("SSH-1 public keys were badly formatted"));
4061 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4062 s->hostkey.bytes : s->servkey.bytes);
4064 s->rsabuf = snewn(s->len, unsigned char);
4067 * Verify the host key.
4071 * First format the key into a string.
4073 int len = rsastr_len(&s->hostkey);
4074 char fingerprint[100];
4075 char *keystr = snewn(len, char);
4076 rsastr_fmt(keystr, &s->hostkey);
4077 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4079 /* First check against manually configured host keys. */
4080 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4081 if (s->dlgret == 0) { /* did not match */
4082 bombout(("Host key did not appear in manually configured list"));
4085 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4086 ssh_set_frozen(ssh, 1);
4087 s->dlgret = verify_ssh_host_key(ssh->frontend,
4088 ssh->savedhost, ssh->savedport,
4089 "rsa", keystr, fingerprint,
4090 ssh_dialog_callback, ssh);
4095 if (s->dlgret < 0) {
4099 bombout(("Unexpected data from server while waiting"
4100 " for user host key response"));
4103 } while (pktin || inlen > 0);
4104 s->dlgret = ssh->user_response;
4106 ssh_set_frozen(ssh, 0);
4108 if (s->dlgret == 0) {
4109 ssh_disconnect(ssh, "User aborted at host key verification",
4118 for (i = 0; i < 32; i++) {
4119 s->rsabuf[i] = ssh->session_key[i];
4121 s->rsabuf[i] ^= s->session_id[i];
4124 if (s->hostkey.bytes > s->servkey.bytes) {
4125 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4127 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4129 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4131 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4134 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4138 logevent("Encrypted session key");
4141 int cipher_chosen = 0, warn = 0;
4142 const char *cipher_string = NULL;
4144 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4145 int next_cipher = conf_get_int_int(ssh->conf,
4146 CONF_ssh_cipherlist, i);
4147 if (next_cipher == CIPHER_WARN) {
4148 /* If/when we choose a cipher, warn about it */
4150 } else if (next_cipher == CIPHER_AES) {
4151 /* XXX Probably don't need to mention this. */
4152 logevent("AES not supported in SSH-1, skipping");
4154 switch (next_cipher) {
4155 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4156 cipher_string = "3DES"; break;
4157 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4158 cipher_string = "Blowfish"; break;
4159 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4160 cipher_string = "single-DES"; break;
4162 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4166 if (!cipher_chosen) {
4167 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4168 bombout(("Server violates SSH-1 protocol by not "
4169 "supporting 3DES encryption"));
4171 /* shouldn't happen */
4172 bombout(("No supported ciphers found"));
4176 /* Warn about chosen cipher if necessary. */
4178 ssh_set_frozen(ssh, 1);
4179 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4180 ssh_dialog_callback, ssh);
4181 if (s->dlgret < 0) {
4185 bombout(("Unexpected data from server while waiting"
4186 " for user response"));
4189 } while (pktin || inlen > 0);
4190 s->dlgret = ssh->user_response;
4192 ssh_set_frozen(ssh, 0);
4193 if (s->dlgret == 0) {
4194 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4201 switch (s->cipher_type) {
4202 case SSH_CIPHER_3DES:
4203 logevent("Using 3DES encryption");
4205 case SSH_CIPHER_DES:
4206 logevent("Using single-DES encryption");
4208 case SSH_CIPHER_BLOWFISH:
4209 logevent("Using Blowfish encryption");
4213 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4214 PKT_CHAR, s->cipher_type,
4215 PKT_DATA, cookie, 8,
4216 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4217 PKT_DATA, s->rsabuf, s->len,
4218 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4220 logevent("Trying to enable encryption...");
4224 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4225 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4227 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4228 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4229 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4231 ssh->crcda_ctx = crcda_make_context();
4232 logevent("Installing CRC compensation attack detector");
4234 if (s->servkey.modulus) {
4235 sfree(s->servkey.modulus);
4236 s->servkey.modulus = NULL;
4238 if (s->servkey.exponent) {
4239 sfree(s->servkey.exponent);
4240 s->servkey.exponent = NULL;
4242 if (s->hostkey.modulus) {
4243 sfree(s->hostkey.modulus);
4244 s->hostkey.modulus = NULL;
4246 if (s->hostkey.exponent) {
4247 sfree(s->hostkey.exponent);
4248 s->hostkey.exponent = NULL;
4252 if (pktin->type != SSH1_SMSG_SUCCESS) {
4253 bombout(("Encryption not successfully enabled"));
4257 logevent("Successfully started encryption");
4259 fflush(stdout); /* FIXME eh? */
4261 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4262 int ret; /* need not be kept over crReturn */
4263 s->cur_prompt = new_prompts(ssh->frontend);
4264 s->cur_prompt->to_server = TRUE;
4265 s->cur_prompt->name = dupstr("SSH login name");
4266 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4267 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4270 crWaitUntil(!pktin);
4271 ret = get_userpass_input(s->cur_prompt, in, inlen);
4276 * Failed to get a username. Terminate.
4278 free_prompts(s->cur_prompt);
4279 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4282 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4283 free_prompts(s->cur_prompt);
4286 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4288 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4290 if (flags & FLAG_INTERACTIVE &&
4291 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4292 c_write_str(ssh, userlog);
4293 c_write_str(ssh, "\r\n");
4301 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4302 /* We must not attempt PK auth. Pretend we've already tried it. */
4303 s->tried_publickey = s->tried_agent = 1;
4305 s->tried_publickey = s->tried_agent = 0;
4307 s->tis_auth_refused = s->ccard_auth_refused = 0;
4309 * Load the public half of any configured keyfile for later use.
4311 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4312 if (!filename_is_null(s->keyfile)) {
4314 logeventf(ssh, "Reading key file \"%.150s\"",
4315 filename_to_str(s->keyfile));
4316 keytype = key_type(s->keyfile);
4317 if (keytype == SSH_KEYTYPE_SSH1 ||
4318 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4320 if (rsakey_pubblob(s->keyfile,
4321 &s->publickey_blob, &s->publickey_bloblen,
4322 &s->publickey_comment, &error)) {
4323 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4324 if (!s->privatekey_available)
4325 logeventf(ssh, "Key file contains public key only");
4326 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4330 logeventf(ssh, "Unable to load key (%s)", error);
4331 msgbuf = dupprintf("Unable to load key file "
4332 "\"%.150s\" (%s)\r\n",
4333 filename_to_str(s->keyfile),
4335 c_write_str(ssh, msgbuf);
4337 s->publickey_blob = NULL;
4341 logeventf(ssh, "Unable to use this key file (%s)",
4342 key_type_to_str(keytype));
4343 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4345 filename_to_str(s->keyfile),
4346 key_type_to_str(keytype));
4347 c_write_str(ssh, msgbuf);
4349 s->publickey_blob = NULL;
4352 s->publickey_blob = NULL;
4354 while (pktin->type == SSH1_SMSG_FAILURE) {
4355 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4357 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4359 * Attempt RSA authentication using Pageant.
4365 logevent("Pageant is running. Requesting keys.");
4367 /* Request the keys held by the agent. */
4368 PUT_32BIT(s->request, 1);
4369 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4370 if (!agent_query(s->request, 5, &r, &s->responselen,
4371 ssh_agent_callback, ssh)) {
4375 bombout(("Unexpected data from server while waiting"
4376 " for agent response"));
4379 } while (pktin || inlen > 0);
4380 r = ssh->agent_response;
4381 s->responselen = ssh->agent_response_len;
4383 s->response = (unsigned char *) r;
4384 if (s->response && s->responselen >= 5 &&
4385 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4386 s->p = s->response + 5;
4387 s->nkeys = toint(GET_32BIT(s->p));
4389 logeventf(ssh, "Pageant reported negative key count %d",
4394 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4395 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4396 unsigned char *pkblob = s->p;
4400 do { /* do while (0) to make breaking easy */
4401 n = ssh1_read_bignum
4402 (s->p, toint(s->responselen-(s->p-s->response)),
4407 n = ssh1_read_bignum
4408 (s->p, toint(s->responselen-(s->p-s->response)),
4413 if (s->responselen - (s->p-s->response) < 4)
4415 s->commentlen = toint(GET_32BIT(s->p));
4417 if (s->commentlen < 0 ||
4418 toint(s->responselen - (s->p-s->response)) <
4421 s->commentp = (char *)s->p;
4422 s->p += s->commentlen;
4426 logevent("Pageant key list packet was truncated");
4430 if (s->publickey_blob) {
4431 if (!memcmp(pkblob, s->publickey_blob,
4432 s->publickey_bloblen)) {
4433 logeventf(ssh, "Pageant key #%d matches "
4434 "configured key file", s->keyi);
4435 s->tried_publickey = 1;
4437 /* Skip non-configured key */
4440 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4441 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4442 PKT_BIGNUM, s->key.modulus, PKT_END);
4444 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4445 logevent("Key refused");
4448 logevent("Received RSA challenge");
4449 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4450 bombout(("Server's RSA challenge was badly formatted"));
4455 char *agentreq, *q, *ret;
4458 len = 1 + 4; /* message type, bit count */
4459 len += ssh1_bignum_length(s->key.exponent);
4460 len += ssh1_bignum_length(s->key.modulus);
4461 len += ssh1_bignum_length(s->challenge);
4462 len += 16; /* session id */
4463 len += 4; /* response format */
4464 agentreq = snewn(4 + len, char);
4465 PUT_32BIT(agentreq, len);
4467 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4468 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4470 q += ssh1_write_bignum(q, s->key.exponent);
4471 q += ssh1_write_bignum(q, s->key.modulus);
4472 q += ssh1_write_bignum(q, s->challenge);
4473 memcpy(q, s->session_id, 16);
4475 PUT_32BIT(q, 1); /* response format */
4476 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4477 ssh_agent_callback, ssh)) {
4482 bombout(("Unexpected data from server"
4483 " while waiting for agent"
4487 } while (pktin || inlen > 0);
4488 vret = ssh->agent_response;
4489 retlen = ssh->agent_response_len;
4494 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4495 logevent("Sending Pageant's response");
4496 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4497 PKT_DATA, ret + 5, 16,
4501 if (pktin->type == SSH1_SMSG_SUCCESS) {
4503 ("Pageant's response accepted");
4504 if (flags & FLAG_VERBOSE) {
4505 c_write_str(ssh, "Authenticated using"
4507 c_write(ssh, s->commentp,
4509 c_write_str(ssh, "\" from agent\r\n");
4514 ("Pageant's response not accepted");
4517 ("Pageant failed to answer challenge");
4521 logevent("No reply received from Pageant");
4524 freebn(s->key.exponent);
4525 freebn(s->key.modulus);
4526 freebn(s->challenge);
4531 if (s->publickey_blob && !s->tried_publickey)
4532 logevent("Configured key file not in Pageant");
4534 logevent("Failed to get reply from Pageant");
4539 if (s->publickey_blob && s->privatekey_available &&
4540 !s->tried_publickey) {
4542 * Try public key authentication with the specified
4545 int got_passphrase; /* need not be kept over crReturn */
4546 if (flags & FLAG_VERBOSE)
4547 c_write_str(ssh, "Trying public key authentication.\r\n");
4548 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4549 logeventf(ssh, "Trying public key \"%s\"",
4550 filename_to_str(s->keyfile));
4551 s->tried_publickey = 1;
4552 got_passphrase = FALSE;
4553 while (!got_passphrase) {
4555 * Get a passphrase, if necessary.
4557 char *passphrase = NULL; /* only written after crReturn */
4559 if (!s->privatekey_encrypted) {
4560 if (flags & FLAG_VERBOSE)
4561 c_write_str(ssh, "No passphrase required.\r\n");
4564 int ret; /* need not be kept over crReturn */
4565 s->cur_prompt = new_prompts(ssh->frontend);
4566 s->cur_prompt->to_server = FALSE;
4567 s->cur_prompt->name = dupstr("SSH key passphrase");
4568 add_prompt(s->cur_prompt,
4569 dupprintf("Passphrase for key \"%.100s\": ",
4570 s->publickey_comment), FALSE);
4571 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4574 crWaitUntil(!pktin);
4575 ret = get_userpass_input(s->cur_prompt, in, inlen);
4579 /* Failed to get a passphrase. Terminate. */
4580 free_prompts(s->cur_prompt);
4581 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4585 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4586 free_prompts(s->cur_prompt);
4589 * Try decrypting key with passphrase.
4591 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4592 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4595 smemclr(passphrase, strlen(passphrase));
4599 /* Correct passphrase. */
4600 got_passphrase = TRUE;
4601 } else if (ret == 0) {
4602 c_write_str(ssh, "Couldn't load private key from ");
4603 c_write_str(ssh, filename_to_str(s->keyfile));
4604 c_write_str(ssh, " (");
4605 c_write_str(ssh, error);
4606 c_write_str(ssh, ").\r\n");
4607 got_passphrase = FALSE;
4608 break; /* go and try something else */
4609 } else if (ret == -1) {
4610 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4611 got_passphrase = FALSE;
4614 assert(0 && "unexpected return from loadrsakey()");
4615 got_passphrase = FALSE; /* placate optimisers */
4619 if (got_passphrase) {
4622 * Send a public key attempt.
4624 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4625 PKT_BIGNUM, s->key.modulus, PKT_END);
4628 if (pktin->type == SSH1_SMSG_FAILURE) {
4629 c_write_str(ssh, "Server refused our public key.\r\n");
4630 continue; /* go and try something else */
4632 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4633 bombout(("Bizarre response to offer of public key"));
4639 unsigned char buffer[32];
4640 Bignum challenge, response;
4642 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4643 bombout(("Server's RSA challenge was badly formatted"));
4646 response = rsadecrypt(challenge, &s->key);
4647 freebn(s->key.private_exponent);/* burn the evidence */
4649 for (i = 0; i < 32; i++) {
4650 buffer[i] = bignum_byte(response, 31 - i);
4654 MD5Update(&md5c, buffer, 32);
4655 MD5Update(&md5c, s->session_id, 16);
4656 MD5Final(buffer, &md5c);
4658 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4659 PKT_DATA, buffer, 16, PKT_END);
4666 if (pktin->type == SSH1_SMSG_FAILURE) {
4667 if (flags & FLAG_VERBOSE)
4668 c_write_str(ssh, "Failed to authenticate with"
4669 " our public key.\r\n");
4670 continue; /* go and try something else */
4671 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4672 bombout(("Bizarre response to RSA authentication response"));
4676 break; /* we're through! */
4682 * Otherwise, try various forms of password-like authentication.
4684 s->cur_prompt = new_prompts(ssh->frontend);
4686 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4687 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4688 !s->tis_auth_refused) {
4689 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4690 logevent("Requested TIS authentication");
4691 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4693 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4694 logevent("TIS authentication declined");
4695 if (flags & FLAG_INTERACTIVE)
4696 c_write_str(ssh, "TIS authentication refused.\r\n");
4697 s->tis_auth_refused = 1;
4702 char *instr_suf, *prompt;
4704 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4706 bombout(("TIS challenge packet was badly formed"));
4709 logevent("Received TIS challenge");
4710 s->cur_prompt->to_server = TRUE;
4711 s->cur_prompt->name = dupstr("SSH TIS authentication");
4712 /* Prompt heuristic comes from OpenSSH */
4713 if (memchr(challenge, '\n', challengelen)) {
4714 instr_suf = dupstr("");
4715 prompt = dupprintf("%.*s", challengelen, challenge);
4717 instr_suf = dupprintf("%.*s", challengelen, challenge);
4718 prompt = dupstr("Response: ");
4720 s->cur_prompt->instruction =
4721 dupprintf("Using TIS authentication.%s%s",
4722 (*instr_suf) ? "\n" : "",
4724 s->cur_prompt->instr_reqd = TRUE;
4725 add_prompt(s->cur_prompt, prompt, FALSE);
4729 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4730 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4731 !s->ccard_auth_refused) {
4732 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4733 logevent("Requested CryptoCard authentication");
4734 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4736 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4737 logevent("CryptoCard authentication declined");
4738 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4739 s->ccard_auth_refused = 1;
4744 char *instr_suf, *prompt;
4746 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4748 bombout(("CryptoCard challenge packet was badly formed"));
4751 logevent("Received CryptoCard challenge");
4752 s->cur_prompt->to_server = TRUE;
4753 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4754 s->cur_prompt->name_reqd = FALSE;
4755 /* Prompt heuristic comes from OpenSSH */
4756 if (memchr(challenge, '\n', challengelen)) {
4757 instr_suf = dupstr("");
4758 prompt = dupprintf("%.*s", challengelen, challenge);
4760 instr_suf = dupprintf("%.*s", challengelen, challenge);
4761 prompt = dupstr("Response: ");
4763 s->cur_prompt->instruction =
4764 dupprintf("Using CryptoCard authentication.%s%s",
4765 (*instr_suf) ? "\n" : "",
4767 s->cur_prompt->instr_reqd = TRUE;
4768 add_prompt(s->cur_prompt, prompt, FALSE);
4772 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4773 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4774 bombout(("No supported authentication methods available"));
4777 s->cur_prompt->to_server = TRUE;
4778 s->cur_prompt->name = dupstr("SSH password");
4779 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4780 ssh->username, ssh->savedhost),
4785 * Show password prompt, having first obtained it via a TIS
4786 * or CryptoCard exchange if we're doing TIS or CryptoCard
4790 int ret; /* need not be kept over crReturn */
4791 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4794 crWaitUntil(!pktin);
4795 ret = get_userpass_input(s->cur_prompt, in, inlen);
4800 * Failed to get a password (for example
4801 * because one was supplied on the command line
4802 * which has already failed to work). Terminate.
4804 free_prompts(s->cur_prompt);
4805 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4810 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4812 * Defence against traffic analysis: we send a
4813 * whole bunch of packets containing strings of
4814 * different lengths. One of these strings is the
4815 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4816 * The others are all random data in
4817 * SSH1_MSG_IGNORE packets. This way a passive
4818 * listener can't tell which is the password, and
4819 * hence can't deduce the password length.
4821 * Anybody with a password length greater than 16
4822 * bytes is going to have enough entropy in their
4823 * password that a listener won't find it _that_
4824 * much help to know how long it is. So what we'll
4827 * - if password length < 16, we send 15 packets
4828 * containing string lengths 1 through 15
4830 * - otherwise, we let N be the nearest multiple
4831 * of 8 below the password length, and send 8
4832 * packets containing string lengths N through
4833 * N+7. This won't obscure the order of
4834 * magnitude of the password length, but it will
4835 * introduce a bit of extra uncertainty.
4837 * A few servers can't deal with SSH1_MSG_IGNORE, at
4838 * least in this context. For these servers, we need
4839 * an alternative defence. We make use of the fact
4840 * that the password is interpreted as a C string:
4841 * so we can append a NUL, then some random data.
4843 * A few servers can deal with neither SSH1_MSG_IGNORE
4844 * here _nor_ a padded password string.
4845 * For these servers we are left with no defences
4846 * against password length sniffing.
4848 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4849 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4851 * The server can deal with SSH1_MSG_IGNORE, so
4852 * we can use the primary defence.
4854 int bottom, top, pwlen, i;
4857 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4859 bottom = 0; /* zero length passwords are OK! :-) */
4862 bottom = pwlen & ~7;
4866 assert(pwlen >= bottom && pwlen <= top);
4868 randomstr = snewn(top + 1, char);
4870 for (i = bottom; i <= top; i++) {
4872 defer_packet(ssh, s->pwpkt_type,
4873 PKT_STR,s->cur_prompt->prompts[0]->result,
4876 for (j = 0; j < i; j++) {
4878 randomstr[j] = random_byte();
4879 } while (randomstr[j] == '\0');
4881 randomstr[i] = '\0';
4882 defer_packet(ssh, SSH1_MSG_IGNORE,
4883 PKT_STR, randomstr, PKT_END);
4886 logevent("Sending password with camouflage packets");
4887 ssh_pkt_defersend(ssh);
4890 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4892 * The server can't deal with SSH1_MSG_IGNORE
4893 * but can deal with padded passwords, so we
4894 * can use the secondary defence.
4900 len = strlen(s->cur_prompt->prompts[0]->result);
4901 if (len < sizeof(string)) {
4903 strcpy(string, s->cur_prompt->prompts[0]->result);
4904 len++; /* cover the zero byte */
4905 while (len < sizeof(string)) {
4906 string[len++] = (char) random_byte();
4909 ss = s->cur_prompt->prompts[0]->result;
4911 logevent("Sending length-padded password");
4912 send_packet(ssh, s->pwpkt_type,
4913 PKT_INT, len, PKT_DATA, ss, len,
4917 * The server is believed unable to cope with
4918 * any of our password camouflage methods.
4921 len = strlen(s->cur_prompt->prompts[0]->result);
4922 logevent("Sending unpadded password");
4923 send_packet(ssh, s->pwpkt_type,
4925 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4929 send_packet(ssh, s->pwpkt_type,
4930 PKT_STR, s->cur_prompt->prompts[0]->result,
4933 logevent("Sent password");
4934 free_prompts(s->cur_prompt);
4936 if (pktin->type == SSH1_SMSG_FAILURE) {
4937 if (flags & FLAG_VERBOSE)
4938 c_write_str(ssh, "Access denied\r\n");
4939 logevent("Authentication refused");
4940 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4941 bombout(("Strange packet received, type %d", pktin->type));
4947 if (s->publickey_blob) {
4948 sfree(s->publickey_blob);
4949 sfree(s->publickey_comment);
4952 logevent("Authentication successful");
4957 static void ssh_channel_try_eof(struct ssh_channel *c)
4960 assert(c->pending_eof); /* precondition for calling us */
4962 return; /* can't close: not even opened yet */
4963 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4964 return; /* can't send EOF: pending outgoing data */
4966 c->pending_eof = FALSE; /* we're about to send it */
4967 if (ssh->version == 1) {
4968 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4970 c->closes |= CLOSES_SENT_EOF;
4972 struct Packet *pktout;
4973 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4974 ssh2_pkt_adduint32(pktout, c->remoteid);
4975 ssh2_pkt_send(ssh, pktout);
4976 c->closes |= CLOSES_SENT_EOF;
4977 ssh2_channel_check_close(c);
4981 Conf *sshfwd_get_conf(struct ssh_channel *c)
4987 void sshfwd_write_eof(struct ssh_channel *c)
4991 if (ssh->state == SSH_STATE_CLOSED)
4994 if (c->closes & CLOSES_SENT_EOF)
4997 c->pending_eof = TRUE;
4998 ssh_channel_try_eof(c);
5001 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
5005 if (ssh->state == SSH_STATE_CLOSED)
5010 x11_close(c->u.x11.xconn);
5011 logeventf(ssh, "Forwarded X11 connection terminated due to local "
5015 pfd_close(c->u.pfd.pf);
5016 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
5019 c->type = CHAN_ZOMBIE;
5020 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5022 ssh2_channel_check_close(c);
5025 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5029 if (ssh->state == SSH_STATE_CLOSED)
5032 return ssh_send_channel_data(c, buf, len);
5035 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5039 if (ssh->state == SSH_STATE_CLOSED)
5042 ssh_channel_unthrottle(c, bufsize);
5045 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5047 struct queued_handler *qh = ssh->qhead;
5051 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5054 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5055 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5058 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5059 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5063 ssh->qhead = qh->next;
5065 if (ssh->qhead->msg1 > 0) {
5066 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5067 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5069 if (ssh->qhead->msg2 > 0) {
5070 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5071 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5074 ssh->qhead = ssh->qtail = NULL;
5077 qh->handler(ssh, pktin, qh->ctx);
5082 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5083 chandler_fn_t handler, void *ctx)
5085 struct queued_handler *qh;
5087 qh = snew(struct queued_handler);
5090 qh->handler = handler;
5094 if (ssh->qtail == NULL) {
5098 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5099 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5102 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5103 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5106 ssh->qtail->next = qh;
5111 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5113 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5115 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5116 SSH2_MSG_REQUEST_SUCCESS)) {
5117 logeventf(ssh, "Remote port forwarding from %s enabled",
5120 logeventf(ssh, "Remote port forwarding from %s refused",
5123 rpf = del234(ssh->rportfwds, pf);
5125 pf->pfrec->remote = NULL;
5130 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5133 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5136 pf->share_ctx = share_ctx;
5137 pf->shost = dupstr(shost);
5139 pf->sportdesc = NULL;
5140 if (!ssh->rportfwds) {
5141 assert(ssh->version == 2);
5142 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5144 if (add234(ssh->rportfwds, pf) != pf) {
5152 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5155 share_got_pkt_from_server(ctx, pktin->type,
5156 pktin->body, pktin->length);
5159 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5161 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5162 ssh_sharing_global_request_response, share_ctx);
5165 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5167 struct ssh_portfwd *epf;
5171 if (!ssh->portfwds) {
5172 ssh->portfwds = newtree234(ssh_portcmp);
5175 * Go through the existing port forwardings and tag them
5176 * with status==DESTROY. Any that we want to keep will be
5177 * re-enabled (status==KEEP) as we go through the
5178 * configuration and find out which bits are the same as
5181 struct ssh_portfwd *epf;
5183 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5184 epf->status = DESTROY;
5187 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5189 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5190 char *kp, *kp2, *vp, *vp2;
5191 char address_family, type;
5192 int sport,dport,sserv,dserv;
5193 char *sports, *dports, *saddr, *host;
5197 address_family = 'A';
5199 if (*kp == 'A' || *kp == '4' || *kp == '6')
5200 address_family = *kp++;
5201 if (*kp == 'L' || *kp == 'R')
5204 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5206 * There's a colon in the middle of the source port
5207 * string, which means that the part before it is
5208 * actually a source address.
5210 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5211 saddr = host_strduptrim(saddr_tmp);
5218 sport = atoi(sports);
5222 sport = net_service_lookup(sports);
5224 logeventf(ssh, "Service lookup failed for source"
5225 " port \"%s\"", sports);
5229 if (type == 'L' && !strcmp(val, "D")) {
5230 /* dynamic forwarding */
5237 /* ordinary forwarding */
5239 vp2 = vp + host_strcspn(vp, ":");
5240 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5244 dport = atoi(dports);
5248 dport = net_service_lookup(dports);
5250 logeventf(ssh, "Service lookup failed for destination"
5251 " port \"%s\"", dports);
5256 if (sport && dport) {
5257 /* Set up a description of the source port. */
5258 struct ssh_portfwd *pfrec, *epfrec;
5260 pfrec = snew(struct ssh_portfwd);
5262 pfrec->saddr = saddr;
5263 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5264 pfrec->sport = sport;
5265 pfrec->daddr = host;
5266 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5267 pfrec->dport = dport;
5268 pfrec->local = NULL;
5269 pfrec->remote = NULL;
5270 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5271 address_family == '6' ? ADDRTYPE_IPV6 :
5274 epfrec = add234(ssh->portfwds, pfrec);
5275 if (epfrec != pfrec) {
5276 if (epfrec->status == DESTROY) {
5278 * We already have a port forwarding up and running
5279 * with precisely these parameters. Hence, no need
5280 * to do anything; simply re-tag the existing one
5283 epfrec->status = KEEP;
5286 * Anything else indicates that there was a duplicate
5287 * in our input, which we'll silently ignore.
5289 free_portfwd(pfrec);
5291 pfrec->status = CREATE;
5300 * Now go through and destroy any port forwardings which were
5303 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5304 if (epf->status == DESTROY) {
5307 message = dupprintf("%s port forwarding from %s%s%d",
5308 epf->type == 'L' ? "local" :
5309 epf->type == 'R' ? "remote" : "dynamic",
5310 epf->saddr ? epf->saddr : "",
5311 epf->saddr ? ":" : "",
5314 if (epf->type != 'D') {
5315 char *msg2 = dupprintf("%s to %s:%d", message,
5316 epf->daddr, epf->dport);
5321 logeventf(ssh, "Cancelling %s", message);
5324 /* epf->remote or epf->local may be NULL if setting up a
5325 * forwarding failed. */
5327 struct ssh_rportfwd *rpf = epf->remote;
5328 struct Packet *pktout;
5331 * Cancel the port forwarding at the server
5334 if (ssh->version == 1) {
5336 * We cannot cancel listening ports on the
5337 * server side in SSH-1! There's no message
5338 * to support it. Instead, we simply remove
5339 * the rportfwd record from the local end
5340 * so that any connections the server tries
5341 * to make on it are rejected.
5344 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5345 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5346 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5348 ssh2_pkt_addstring(pktout, epf->saddr);
5349 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5350 /* XXX: rport_acceptall may not represent
5351 * what was used to open the original connection,
5352 * since it's reconfigurable. */
5353 ssh2_pkt_addstring(pktout, "");
5355 ssh2_pkt_addstring(pktout, "localhost");
5357 ssh2_pkt_adduint32(pktout, epf->sport);
5358 ssh2_pkt_send(ssh, pktout);
5361 del234(ssh->rportfwds, rpf);
5363 } else if (epf->local) {
5364 pfl_terminate(epf->local);
5367 delpos234(ssh->portfwds, i);
5369 i--; /* so we don't skip one in the list */
5373 * And finally, set up any new port forwardings (status==CREATE).
5375 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5376 if (epf->status == CREATE) {
5377 char *sportdesc, *dportdesc;
5378 sportdesc = dupprintf("%s%s%s%s%d%s",
5379 epf->saddr ? epf->saddr : "",
5380 epf->saddr ? ":" : "",
5381 epf->sserv ? epf->sserv : "",
5382 epf->sserv ? "(" : "",
5384 epf->sserv ? ")" : "");
5385 if (epf->type == 'D') {
5388 dportdesc = dupprintf("%s:%s%s%d%s",
5390 epf->dserv ? epf->dserv : "",
5391 epf->dserv ? "(" : "",
5393 epf->dserv ? ")" : "");
5396 if (epf->type == 'L') {
5397 char *err = pfl_listen(epf->daddr, epf->dport,
5398 epf->saddr, epf->sport,
5399 ssh, conf, &epf->local,
5400 epf->addressfamily);
5402 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5403 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5404 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5405 sportdesc, dportdesc,
5406 err ? " failed: " : "", err ? err : "");
5409 } else if (epf->type == 'D') {
5410 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5411 ssh, conf, &epf->local,
5412 epf->addressfamily);
5414 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5415 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5416 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5418 err ? " failed: " : "", err ? err : "");
5423 struct ssh_rportfwd *pf;
5426 * Ensure the remote port forwardings tree exists.
5428 if (!ssh->rportfwds) {
5429 if (ssh->version == 1)
5430 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5432 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5435 pf = snew(struct ssh_rportfwd);
5436 pf->share_ctx = NULL;
5437 pf->dhost = dupstr(epf->daddr);
5438 pf->dport = epf->dport;
5440 pf->shost = dupstr(epf->saddr);
5441 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5442 pf->shost = dupstr("");
5444 pf->shost = dupstr("localhost");
5446 pf->sport = epf->sport;
5447 if (add234(ssh->rportfwds, pf) != pf) {
5448 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5449 epf->daddr, epf->dport);
5452 logeventf(ssh, "Requesting remote port %s"
5453 " forward to %s", sportdesc, dportdesc);
5455 pf->sportdesc = sportdesc;
5460 if (ssh->version == 1) {
5461 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5462 PKT_INT, epf->sport,
5463 PKT_STR, epf->daddr,
5464 PKT_INT, epf->dport,
5466 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5468 ssh_rportfwd_succfail, pf);
5470 struct Packet *pktout;
5471 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5472 ssh2_pkt_addstring(pktout, "tcpip-forward");
5473 ssh2_pkt_addbool(pktout, 1);/* want reply */
5474 ssh2_pkt_addstring(pktout, pf->shost);
5475 ssh2_pkt_adduint32(pktout, pf->sport);
5476 ssh2_pkt_send(ssh, pktout);
5478 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5479 SSH2_MSG_REQUEST_FAILURE,
5480 ssh_rportfwd_succfail, pf);
5489 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5492 int stringlen, bufsize;
5494 ssh_pkt_getstring(pktin, &string, &stringlen);
5495 if (string == NULL) {
5496 bombout(("Incoming terminal data packet was badly formed"));
5500 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5502 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5503 ssh->v1_stdout_throttling = 1;
5504 ssh_throttle_conn(ssh, +1);
5508 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5510 /* Remote side is trying to open a channel to talk to our
5511 * X-Server. Give them back a local channel number. */
5512 struct ssh_channel *c;
5513 int remoteid = ssh_pkt_getuint32(pktin);
5515 logevent("Received X11 connect request");
5516 /* Refuse if X11 forwarding is disabled. */
5517 if (!ssh->X11_fwd_enabled) {
5518 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5519 PKT_INT, remoteid, PKT_END);
5520 logevent("Rejected X11 connect request");
5522 c = snew(struct ssh_channel);
5525 ssh_channel_init(c);
5526 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5527 c->remoteid = remoteid;
5528 c->halfopen = FALSE;
5529 c->type = CHAN_X11; /* identify channel type */
5530 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5531 PKT_INT, c->remoteid, PKT_INT,
5532 c->localid, PKT_END);
5533 logevent("Opened X11 forward channel");
5537 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5539 /* Remote side is trying to open a channel to talk to our
5540 * agent. Give them back a local channel number. */
5541 struct ssh_channel *c;
5542 int remoteid = ssh_pkt_getuint32(pktin);
5544 /* Refuse if agent forwarding is disabled. */
5545 if (!ssh->agentfwd_enabled) {
5546 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5547 PKT_INT, remoteid, PKT_END);
5549 c = snew(struct ssh_channel);
5551 ssh_channel_init(c);
5552 c->remoteid = remoteid;
5553 c->halfopen = FALSE;
5554 c->type = CHAN_AGENT; /* identify channel type */
5555 c->u.a.lensofar = 0;
5556 c->u.a.message = NULL;
5557 c->u.a.outstanding_requests = 0;
5558 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5559 PKT_INT, c->remoteid, PKT_INT, c->localid,
5564 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5566 /* Remote side is trying to open a channel to talk to a
5567 * forwarded port. Give them back a local channel number. */
5568 struct ssh_rportfwd pf, *pfp;
5574 remoteid = ssh_pkt_getuint32(pktin);
5575 ssh_pkt_getstring(pktin, &host, &hostsize);
5576 port = ssh_pkt_getuint32(pktin);
5578 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5580 pfp = find234(ssh->rportfwds, &pf, NULL);
5583 logeventf(ssh, "Rejected remote port open request for %s:%d",
5585 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5586 PKT_INT, remoteid, PKT_END);
5588 struct ssh_channel *c = snew(struct ssh_channel);
5591 logeventf(ssh, "Received remote port open request for %s:%d",
5593 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5594 c, ssh->conf, pfp->pfrec->addressfamily);
5596 logeventf(ssh, "Port open failed: %s", err);
5599 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5600 PKT_INT, remoteid, PKT_END);
5602 ssh_channel_init(c);
5603 c->remoteid = remoteid;
5604 c->halfopen = FALSE;
5605 c->type = CHAN_SOCKDATA; /* identify channel type */
5606 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5607 PKT_INT, c->remoteid, PKT_INT,
5608 c->localid, PKT_END);
5609 logevent("Forwarded port opened successfully");
5616 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5618 struct ssh_channel *c;
5620 c = ssh_channel_msg(ssh, pktin);
5621 if (c && c->type == CHAN_SOCKDATA) {
5622 c->remoteid = ssh_pkt_getuint32(pktin);
5623 c->halfopen = FALSE;
5624 c->throttling_conn = 0;
5625 pfd_confirm(c->u.pfd.pf);
5628 if (c && c->pending_eof) {
5630 * We have a pending close on this channel,
5631 * which we decided on before the server acked
5632 * the channel open. So now we know the
5633 * remoteid, we can close it again.
5635 ssh_channel_try_eof(c);
5639 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5641 struct ssh_channel *c;
5643 c = ssh_channel_msg(ssh, pktin);
5644 if (c && c->type == CHAN_SOCKDATA) {
5645 logevent("Forwarded connection refused by server");
5646 pfd_close(c->u.pfd.pf);
5647 del234(ssh->channels, c);
5652 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5654 /* Remote side closes a channel. */
5655 struct ssh_channel *c;
5657 c = ssh_channel_msg(ssh, pktin);
5660 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5661 !(c->closes & CLOSES_RCVD_EOF)) {
5663 * Received CHANNEL_CLOSE, which we translate into
5666 int send_close = FALSE;
5668 c->closes |= CLOSES_RCVD_EOF;
5673 x11_send_eof(c->u.x11.xconn);
5679 pfd_send_eof(c->u.pfd.pf);
5688 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5689 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5691 c->closes |= CLOSES_SENT_EOF;
5695 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5696 !(c->closes & CLOSES_RCVD_CLOSE)) {
5698 if (!(c->closes & CLOSES_SENT_EOF)) {
5699 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %u"
5700 " for which we never sent CHANNEL_CLOSE\n",
5704 c->closes |= CLOSES_RCVD_CLOSE;
5707 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5708 !(c->closes & CLOSES_SENT_CLOSE)) {
5709 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5710 PKT_INT, c->remoteid, PKT_END);
5711 c->closes |= CLOSES_SENT_CLOSE;
5714 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5715 ssh_channel_destroy(c);
5720 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5722 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5725 while (length > 0) {
5726 if (c->u.a.lensofar < 4) {
5727 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)length);
5728 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
5731 c->u.a.lensofar += l;
5733 if (c->u.a.lensofar == 4) {
5734 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
5735 c->u.a.message = snewn(c->u.a.totallen, unsigned char);
5736 memcpy(c->u.a.message, c->u.a.msglen, 4);
5738 if (c->u.a.lensofar >= 4 && length > 0) {
5739 unsigned int l = min(c->u.a.totallen - c->u.a.lensofar,
5741 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
5744 c->u.a.lensofar += l;
5746 if (c->u.a.lensofar == c->u.a.totallen) {
5749 c->u.a.outstanding_requests++;
5750 if (agent_query(c->u.a.message, c->u.a.totallen, &reply, &replylen,
5751 ssh_agentf_callback, c))
5752 ssh_agentf_callback(c, reply, replylen);
5753 sfree(c->u.a.message);
5754 c->u.a.message = NULL;
5755 c->u.a.lensofar = 0;
5758 return 0; /* agent channels never back up */
5761 static int ssh_channel_data(struct ssh_channel *c, int is_stderr,
5762 char *data, int length)
5765 case CHAN_MAINSESSION:
5766 return from_backend(c->ssh->frontend, is_stderr, data, length);
5768 return x11_send(c->u.x11.xconn, data, length);
5770 return pfd_send(c->u.pfd.pf, data, length);
5772 return ssh_agent_channel_data(c, data, length);
5777 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5779 /* Data sent down one of our channels. */
5782 struct ssh_channel *c;
5784 c = ssh_channel_msg(ssh, pktin);
5785 ssh_pkt_getstring(pktin, &p, &len);
5788 int bufsize = ssh_channel_data(c, FALSE, p, len);
5789 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5790 c->throttling_conn = 1;
5791 ssh_throttle_conn(ssh, +1);
5796 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5798 ssh->exitcode = ssh_pkt_getuint32(pktin);
5799 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5800 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5802 * In case `helpful' firewalls or proxies tack
5803 * extra human-readable text on the end of the
5804 * session which we might mistake for another
5805 * encrypted packet, we close the session once
5806 * we've sent EXIT_CONFIRMATION.
5808 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5811 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5812 static void ssh1_send_ttymode(void *data,
5813 const struct ssh_ttymode *mode, char *val)
5815 struct Packet *pktout = (struct Packet *)data;
5816 unsigned int arg = 0;
5818 switch (mode->type) {
5820 arg = ssh_tty_parse_specchar(val);
5823 arg = ssh_tty_parse_boolean(val);
5826 ssh2_pkt_addbyte(pktout, mode->opcode);
5827 ssh2_pkt_addbyte(pktout, arg);
5830 int ssh_agent_forwarding_permitted(Ssh ssh)
5832 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5835 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5836 struct Packet *pktin)
5838 crBegin(ssh->do_ssh1_connection_crstate);
5840 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5841 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5842 ssh1_smsg_stdout_stderr_data;
5844 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5845 ssh1_msg_channel_open_confirmation;
5846 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5847 ssh1_msg_channel_open_failure;
5848 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5849 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5850 ssh1_msg_channel_close;
5851 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5852 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5854 if (ssh_agent_forwarding_permitted(ssh)) {
5855 logevent("Requesting agent forwarding");
5856 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5860 if (pktin->type != SSH1_SMSG_SUCCESS
5861 && pktin->type != SSH1_SMSG_FAILURE) {
5862 bombout(("Protocol confusion"));
5864 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5865 logevent("Agent forwarding refused");
5867 logevent("Agent forwarding enabled");
5868 ssh->agentfwd_enabled = TRUE;
5869 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5873 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5875 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5877 if (!ssh->x11disp) {
5878 /* FIXME: return an error message from x11_setup_display */
5879 logevent("X11 forwarding not enabled: unable to"
5880 " initialise X display");
5882 ssh->x11auth = x11_invent_fake_auth
5883 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5884 ssh->x11auth->disp = ssh->x11disp;
5886 logevent("Requesting X11 forwarding");
5887 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5888 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5889 PKT_STR, ssh->x11auth->protoname,
5890 PKT_STR, ssh->x11auth->datastring,
5891 PKT_INT, ssh->x11disp->screennum,
5894 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5895 PKT_STR, ssh->x11auth->protoname,
5896 PKT_STR, ssh->x11auth->datastring,
5902 if (pktin->type != SSH1_SMSG_SUCCESS
5903 && pktin->type != SSH1_SMSG_FAILURE) {
5904 bombout(("Protocol confusion"));
5906 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5907 logevent("X11 forwarding refused");
5909 logevent("X11 forwarding enabled");
5910 ssh->X11_fwd_enabled = TRUE;
5911 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5916 ssh_setup_portfwd(ssh, ssh->conf);
5917 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5919 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5921 /* Unpick the terminal-speed string. */
5922 /* XXX perhaps we should allow no speeds to be sent. */
5923 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5924 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5925 /* Send the pty request. */
5926 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5927 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5928 ssh_pkt_adduint32(pkt, ssh->term_height);
5929 ssh_pkt_adduint32(pkt, ssh->term_width);
5930 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5931 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5932 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5933 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5934 ssh_pkt_adduint32(pkt, ssh->ispeed);
5935 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5936 ssh_pkt_adduint32(pkt, ssh->ospeed);
5937 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5939 ssh->state = SSH_STATE_INTERMED;
5943 if (pktin->type != SSH1_SMSG_SUCCESS
5944 && pktin->type != SSH1_SMSG_FAILURE) {
5945 bombout(("Protocol confusion"));
5947 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5948 c_write_str(ssh, "Server refused to allocate pty\r\n");
5949 ssh->editing = ssh->echoing = 1;
5951 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5952 ssh->ospeed, ssh->ispeed);
5953 ssh->got_pty = TRUE;
5956 ssh->editing = ssh->echoing = 1;
5959 if (conf_get_int(ssh->conf, CONF_compression)) {
5960 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5964 if (pktin->type != SSH1_SMSG_SUCCESS
5965 && pktin->type != SSH1_SMSG_FAILURE) {
5966 bombout(("Protocol confusion"));
5968 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5969 c_write_str(ssh, "Server refused to compress\r\n");
5971 logevent("Started compression");
5972 ssh->v1_compressing = TRUE;
5973 ssh->cs_comp_ctx = zlib_compress_init();
5974 logevent("Initialised zlib (RFC1950) compression");
5975 ssh->sc_comp_ctx = zlib_decompress_init();
5976 logevent("Initialised zlib (RFC1950) decompression");
5980 * Start the shell or command.
5982 * Special case: if the first-choice command is an SSH-2
5983 * subsystem (hence not usable here) and the second choice
5984 * exists, we fall straight back to that.
5987 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5989 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5990 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5991 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5992 ssh->fallback_cmd = TRUE;
5995 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5997 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5998 logevent("Started session");
6001 ssh->state = SSH_STATE_SESSION;
6002 if (ssh->size_needed)
6003 ssh_size(ssh, ssh->term_width, ssh->term_height);
6004 if (ssh->eof_needed)
6005 ssh_special(ssh, TS_EOF);
6008 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6010 ssh->channels = newtree234(ssh_channelcmp);
6014 * By this point, most incoming packets are already being
6015 * handled by the dispatch table, and we need only pay
6016 * attention to the unusual ones.
6021 if (pktin->type == SSH1_SMSG_SUCCESS) {
6022 /* may be from EXEC_SHELL on some servers */
6023 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6024 /* may be from EXEC_SHELL on some servers
6025 * if no pty is available or in other odd cases. Ignore */
6027 bombout(("Strange packet received: type %d", pktin->type));
6032 int len = min(inlen, 512);
6033 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6034 PKT_INT, len, PKT_DATA, in, len,
6046 * Handle the top-level SSH-2 protocol.
6048 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6053 ssh_pkt_getstring(pktin, &msg, &msglen);
6054 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6057 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6059 /* log reason code in disconnect message */
6063 ssh_pkt_getstring(pktin, &msg, &msglen);
6064 bombout(("Server sent disconnect message:\n\"%.*s\"",
6065 msglen, NULLTOEMPTY(msg)));
6068 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6070 /* Do nothing, because we're ignoring it! Duhh. */
6073 static void ssh1_protocol_setup(Ssh ssh)
6078 * Most messages are handled by the coroutines.
6080 for (i = 0; i < 256; i++)
6081 ssh->packet_dispatch[i] = NULL;
6084 * These special message types we install handlers for.
6086 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6087 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6088 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6091 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6092 struct Packet *pktin)
6094 const unsigned char *in = (const unsigned char *)vin;
6095 if (ssh->state == SSH_STATE_CLOSED)
6098 if (pktin && ssh->packet_dispatch[pktin->type]) {
6099 ssh->packet_dispatch[pktin->type](ssh, pktin);
6103 if (!ssh->protocol_initial_phase_done) {
6104 if (do_ssh1_login(ssh, in, inlen, pktin))
6105 ssh->protocol_initial_phase_done = TRUE;
6110 do_ssh1_connection(ssh, in, inlen, pktin);
6114 * Utility routines for decoding comma-separated strings in KEXINIT.
6116 static int first_in_commasep_string(char const *needle, char const *haystack,
6120 if (!needle || !haystack) /* protect against null pointers */
6122 needlen = strlen(needle);
6124 if (haylen >= needlen && /* haystack is long enough */
6125 !memcmp(needle, haystack, needlen) && /* initial match */
6126 (haylen == needlen || haystack[needlen] == ',')
6127 /* either , or EOS follows */
6133 static int in_commasep_string(char const *needle, char const *haystack,
6138 if (!needle || !haystack) /* protect against null pointers */
6141 * Is it at the start of the string?
6143 if (first_in_commasep_string(needle, haystack, haylen))
6146 * If not, search for the next comma and resume after that.
6147 * If no comma found, terminate.
6149 p = memchr(haystack, ',', haylen);
6151 /* + 1 to skip over comma */
6152 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6156 * Add a value to the comma-separated string at the end of the packet.
6158 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6160 if (pkt->length - pkt->savedpos > 0)
6161 ssh_pkt_addstring_str(pkt, ",");
6162 ssh_pkt_addstring_str(pkt, data);
6167 * SSH-2 key derivation (RFC 4253 section 7.2).
6169 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6170 char chr, int keylen)
6172 const struct ssh_hash *h = ssh->kex->hash;
6180 /* Round up to the next multiple of hash length. */
6181 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6183 key = snewn(keylen_padded, unsigned char);
6185 /* First hlen bytes. */
6187 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6188 hash_mpint(h, s, K);
6189 h->bytes(s, H, h->hlen);
6190 h->bytes(s, &chr, 1);
6191 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6194 /* Subsequent blocks of hlen bytes. */
6195 if (keylen_padded > h->hlen) {
6199 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6200 hash_mpint(h, s, K);
6201 h->bytes(s, H, h->hlen);
6203 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6204 h->bytes(s, key + offset - h->hlen, h->hlen);
6206 h->final(s2, key + offset);
6212 /* Now clear any extra bytes of key material beyond the length
6213 * we're officially returning, because the caller won't know to
6215 if (keylen_padded > keylen)
6216 smemclr(key + keylen, keylen_padded - keylen);
6222 * Structure for constructing KEXINIT algorithm lists.
6224 #define MAXKEXLIST 16
6225 struct kexinit_algorithm {
6229 const struct ssh_kex *kex;
6233 const struct ssh_signkey *hostkey;
6237 const struct ssh2_cipher *cipher;
6241 const struct ssh_mac *mac;
6244 const struct ssh_compress *comp;
6249 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6250 * If the algorithm is already in the list, return a pointer to its
6251 * entry, otherwise return an entry from the end of the list.
6252 * This assumes that every time a particular name is passed in, it
6253 * comes from the same string constant. If this isn't true, this
6254 * function may need to be rewritten to use strcmp() instead.
6256 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6257 *list, const char *name)
6261 for (i = 0; i < MAXKEXLIST; i++)
6262 if (list[i].name == NULL || list[i].name == name) {
6263 list[i].name = name;
6266 assert(!"No space in KEXINIT list");
6271 * Handle the SSH-2 transport layer.
6273 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6274 struct Packet *pktin)
6276 const unsigned char *in = (const unsigned char *)vin;
6278 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6279 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6282 const char * kexlist_descr[NKEXLIST] = {
6283 "key exchange algorithm", "host key algorithm",
6284 "client-to-server cipher", "server-to-client cipher",
6285 "client-to-server MAC", "server-to-client MAC",
6286 "client-to-server compression method",
6287 "server-to-client compression method" };
6288 struct do_ssh2_transport_state {
6290 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6291 Bignum p, g, e, f, K;
6294 int kex_init_value, kex_reply_value;
6295 const struct ssh_mac *const *maclist;
6297 const struct ssh2_cipher *cscipher_tobe;
6298 const struct ssh2_cipher *sccipher_tobe;
6299 const struct ssh_mac *csmac_tobe;
6300 const struct ssh_mac *scmac_tobe;
6301 int csmac_etm_tobe, scmac_etm_tobe;
6302 const struct ssh_compress *cscomp_tobe;
6303 const struct ssh_compress *sccomp_tobe;
6304 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6305 int hostkeylen, siglen, rsakeylen;
6306 void *hkey; /* actual host key */
6307 void *rsakey; /* for RSA kex */
6308 void *eckey; /* for ECDH kex */
6309 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6310 int n_preferred_kex;
6311 const struct ssh_kexes *preferred_kex[KEX_MAX];
6313 int preferred_hk[HK_MAX];
6314 int n_preferred_ciphers;
6315 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6316 const struct ssh_compress *preferred_comp;
6317 int userauth_succeeded; /* for delayed compression */
6318 int pending_compression;
6319 int got_session_id, activated_authconn;
6320 struct Packet *pktout;
6324 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6326 crState(do_ssh2_transport_state);
6328 assert(!ssh->bare_connection);
6329 assert(ssh->version == 2);
6333 s->cscipher_tobe = s->sccipher_tobe = NULL;
6334 s->csmac_tobe = s->scmac_tobe = NULL;
6335 s->cscomp_tobe = s->sccomp_tobe = NULL;
6337 s->got_session_id = s->activated_authconn = FALSE;
6338 s->userauth_succeeded = FALSE;
6339 s->pending_compression = FALSE;
6342 * Be prepared to work around the buggy MAC problem.
6344 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6345 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6347 s->maclist = macs, s->nmacs = lenof(macs);
6350 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6353 struct kexinit_algorithm *alg;
6356 * Set up the preferred key exchange. (NULL => warn below here)
6358 s->n_preferred_kex = 0;
6359 for (i = 0; i < KEX_MAX; i++) {
6360 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6362 s->preferred_kex[s->n_preferred_kex++] =
6363 &ssh_diffiehellman_gex;
6366 s->preferred_kex[s->n_preferred_kex++] =
6367 &ssh_diffiehellman_group14;
6370 s->preferred_kex[s->n_preferred_kex++] =
6371 &ssh_diffiehellman_group1;
6374 s->preferred_kex[s->n_preferred_kex++] =
6378 s->preferred_kex[s->n_preferred_kex++] =
6382 /* Flag for later. Don't bother if it's the last in
6384 if (i < KEX_MAX - 1) {
6385 s->preferred_kex[s->n_preferred_kex++] = NULL;
6392 * Set up the preferred host key types. These are just the ids
6393 * in the enum in putty.h, so 'warn below here' is indicated
6396 s->n_preferred_hk = 0;
6397 for (i = 0; i < HK_MAX; i++) {
6398 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6399 /* As above, don't bother with HK_WARN if it's last in the
6401 if (id != HK_WARN || i < HK_MAX - 1)
6402 s->preferred_hk[s->n_preferred_hk++] = id;
6406 * Set up the preferred ciphers. (NULL => warn below here)
6408 s->n_preferred_ciphers = 0;
6409 for (i = 0; i < CIPHER_MAX; i++) {
6410 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6411 case CIPHER_BLOWFISH:
6412 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6415 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6416 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6420 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6423 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6425 case CIPHER_ARCFOUR:
6426 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6428 case CIPHER_CHACHA20:
6429 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6432 /* Flag for later. Don't bother if it's the last in
6434 if (i < CIPHER_MAX - 1) {
6435 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6442 * Set up preferred compression.
6444 if (conf_get_int(ssh->conf, CONF_compression))
6445 s->preferred_comp = &ssh_zlib;
6447 s->preferred_comp = &ssh_comp_none;
6450 * Enable queueing of outgoing auth- or connection-layer
6451 * packets while we are in the middle of a key exchange.
6453 ssh->queueing = TRUE;
6456 * Flag that KEX is in progress.
6458 ssh->kex_in_progress = TRUE;
6460 for (i = 0; i < NKEXLIST; i++)
6461 for (j = 0; j < MAXKEXLIST; j++)
6462 s->kexlists[i][j].name = NULL;
6463 /* List key exchange algorithms. */
6465 for (i = 0; i < s->n_preferred_kex; i++) {
6466 const struct ssh_kexes *k = s->preferred_kex[i];
6467 if (!k) warn = TRUE;
6468 else for (j = 0; j < k->nkexes; j++) {
6469 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6471 alg->u.kex.kex = k->list[j];
6472 alg->u.kex.warn = warn;
6475 /* List server host key algorithms. */
6476 if (!s->got_session_id) {
6478 * In the first key exchange, we list all the algorithms
6479 * we're prepared to cope with, but prefer those algorithms
6480 * for which we have a host key for this host.
6482 * If the host key algorithm is below the warning
6483 * threshold, we warn even if we did already have a key
6484 * for it, on the basis that if the user has just
6485 * reconfigured that host key type to be warned about,
6486 * they surely _do_ want to be alerted that a server
6487 * they're actually connecting to is using it.
6490 for (i = 0; i < s->n_preferred_hk; i++) {
6491 if (s->preferred_hk[i] == HK_WARN)
6493 for (j = 0; j < lenof(hostkey_algs); j++) {
6494 if (hostkey_algs[j].id != s->preferred_hk[i])
6496 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6497 hostkey_algs[j].alg->keytype)) {
6498 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6499 hostkey_algs[j].alg->name);
6500 alg->u.hk.hostkey = hostkey_algs[j].alg;
6501 alg->u.hk.warn = warn;
6506 for (i = 0; i < s->n_preferred_hk; i++) {
6507 if (s->preferred_hk[i] == HK_WARN)
6509 for (j = 0; j < lenof(hostkey_algs); j++) {
6510 if (hostkey_algs[j].id != s->preferred_hk[i])
6512 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6513 hostkey_algs[j].alg->name);
6514 alg->u.hk.hostkey = hostkey_algs[j].alg;
6515 alg->u.hk.warn = warn;
6520 * In subsequent key exchanges, we list only the kex
6521 * algorithm that was selected in the first key exchange,
6522 * so that we keep getting the same host key and hence
6523 * don't have to interrupt the user's session to ask for
6527 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6528 ssh->hostkey->name);
6529 alg->u.hk.hostkey = ssh->hostkey;
6530 alg->u.hk.warn = FALSE;
6532 /* List encryption algorithms (client->server then server->client). */
6533 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6536 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6537 alg->u.cipher.cipher = NULL;
6538 alg->u.cipher.warn = warn;
6539 #endif /* FUZZING */
6540 for (i = 0; i < s->n_preferred_ciphers; i++) {
6541 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6542 if (!c) warn = TRUE;
6543 else for (j = 0; j < c->nciphers; j++) {
6544 alg = ssh2_kexinit_addalg(s->kexlists[k],
6546 alg->u.cipher.cipher = c->list[j];
6547 alg->u.cipher.warn = warn;
6551 /* List MAC algorithms (client->server then server->client). */
6552 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6554 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6555 alg->u.mac.mac = NULL;
6556 alg->u.mac.etm = FALSE;
6557 #endif /* FUZZING */
6558 for (i = 0; i < s->nmacs; i++) {
6559 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6560 alg->u.mac.mac = s->maclist[i];
6561 alg->u.mac.etm = FALSE;
6563 for (i = 0; i < s->nmacs; i++)
6564 /* For each MAC, there may also be an ETM version,
6565 * which we list second. */
6566 if (s->maclist[i]->etm_name) {
6567 alg = ssh2_kexinit_addalg(s->kexlists[j],
6568 s->maclist[i]->etm_name);
6569 alg->u.mac.mac = s->maclist[i];
6570 alg->u.mac.etm = TRUE;
6573 /* List client->server compression algorithms,
6574 * then server->client compression algorithms. (We use the
6575 * same set twice.) */
6576 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6577 assert(lenof(compressions) > 1);
6578 /* Prefer non-delayed versions */
6579 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6580 alg->u.comp = s->preferred_comp;
6581 /* We don't even list delayed versions of algorithms until
6582 * they're allowed to be used, to avoid a race. See the end of
6584 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6585 alg = ssh2_kexinit_addalg(s->kexlists[j],
6586 s->preferred_comp->delayed_name);
6587 alg->u.comp = s->preferred_comp;
6589 for (i = 0; i < lenof(compressions); i++) {
6590 const struct ssh_compress *c = compressions[i];
6591 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6593 if (s->userauth_succeeded && c->delayed_name) {
6594 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6600 * Construct and send our key exchange packet.
6602 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6603 for (i = 0; i < 16; i++)
6604 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6605 for (i = 0; i < NKEXLIST; i++) {
6606 ssh2_pkt_addstring_start(s->pktout);
6607 for (j = 0; j < MAXKEXLIST; j++) {
6608 if (s->kexlists[i][j].name == NULL) break;
6609 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6612 /* List client->server languages. Empty list. */
6613 ssh2_pkt_addstring_start(s->pktout);
6614 /* List server->client languages. Empty list. */
6615 ssh2_pkt_addstring_start(s->pktout);
6616 /* First KEX packet does _not_ follow, because we're not that brave. */
6617 ssh2_pkt_addbool(s->pktout, FALSE);
6619 ssh2_pkt_adduint32(s->pktout, 0);
6622 s->our_kexinitlen = s->pktout->length - 5;
6623 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6624 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6626 ssh2_pkt_send_noqueue(ssh, s->pktout);
6629 crWaitUntilV(pktin);
6632 * Now examine the other side's KEXINIT to see what we're up
6639 if (pktin->type != SSH2_MSG_KEXINIT) {
6640 bombout(("expected key exchange packet from server"));
6644 ssh->hostkey = NULL;
6645 s->cscipher_tobe = NULL;
6646 s->sccipher_tobe = NULL;
6647 s->csmac_tobe = NULL;
6648 s->scmac_tobe = NULL;
6649 s->cscomp_tobe = NULL;
6650 s->sccomp_tobe = NULL;
6651 s->warn_kex = s->warn_hk = FALSE;
6652 s->warn_cscipher = s->warn_sccipher = FALSE;
6654 pktin->savedpos += 16; /* skip garbage cookie */
6657 for (i = 0; i < NKEXLIST; i++) {
6658 ssh_pkt_getstring(pktin, &str, &len);
6660 bombout(("KEXINIT packet was incomplete"));
6664 /* If we've already selected a cipher which requires a
6665 * particular MAC, then just select that, and don't even
6666 * bother looking through the server's KEXINIT string for
6668 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6669 s->cscipher_tobe->required_mac) {
6670 s->csmac_tobe = s->cscipher_tobe->required_mac;
6671 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6674 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6675 s->sccipher_tobe->required_mac) {
6676 s->scmac_tobe = s->sccipher_tobe->required_mac;
6677 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6681 for (j = 0; j < MAXKEXLIST; j++) {
6682 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6683 if (alg->name == NULL) break;
6684 if (in_commasep_string(alg->name, str, len)) {
6685 /* We've found a matching algorithm. */
6686 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6687 /* Check if we might need to ignore first kex pkt */
6689 !first_in_commasep_string(alg->name, str, len))
6692 if (i == KEXLIST_KEX) {
6693 ssh->kex = alg->u.kex.kex;
6694 s->warn_kex = alg->u.kex.warn;
6695 } else if (i == KEXLIST_HOSTKEY) {
6696 ssh->hostkey = alg->u.hk.hostkey;
6697 s->warn_hk = alg->u.hk.warn;
6698 } else if (i == KEXLIST_CSCIPHER) {
6699 s->cscipher_tobe = alg->u.cipher.cipher;
6700 s->warn_cscipher = alg->u.cipher.warn;
6701 } else if (i == KEXLIST_SCCIPHER) {
6702 s->sccipher_tobe = alg->u.cipher.cipher;
6703 s->warn_sccipher = alg->u.cipher.warn;
6704 } else if (i == KEXLIST_CSMAC) {
6705 s->csmac_tobe = alg->u.mac.mac;
6706 s->csmac_etm_tobe = alg->u.mac.etm;
6707 } else if (i == KEXLIST_SCMAC) {
6708 s->scmac_tobe = alg->u.mac.mac;
6709 s->scmac_etm_tobe = alg->u.mac.etm;
6710 } else if (i == KEXLIST_CSCOMP) {
6711 s->cscomp_tobe = alg->u.comp;
6712 } else if (i == KEXLIST_SCCOMP) {
6713 s->sccomp_tobe = alg->u.comp;
6717 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6718 in_commasep_string(alg->u.comp->delayed_name, str, len))
6719 s->pending_compression = TRUE; /* try this later */
6721 bombout(("Couldn't agree a %s (available: %.*s)",
6722 kexlist_descr[i], len, str));
6726 if (i == KEXLIST_HOSTKEY) {
6730 * In addition to deciding which host key we're
6731 * actually going to use, we should make a list of the
6732 * host keys offered by the server which we _don't_
6733 * have cached. These will be offered as cross-
6734 * certification options by ssh_get_specials.
6736 * We also count the key we're currently using for KEX
6737 * as one we've already got, because by the time this
6738 * menu becomes visible, it will be.
6740 ssh->n_uncert_hostkeys = 0;
6742 for (j = 0; j < lenof(hostkey_algs); j++) {
6743 if (hostkey_algs[j].alg != ssh->hostkey &&
6744 in_commasep_string(hostkey_algs[j].alg->name,
6746 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6747 hostkey_algs[j].alg->keytype)) {
6748 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6754 if (s->pending_compression) {
6755 logevent("Server supports delayed compression; "
6756 "will try this later");
6758 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6759 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6760 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6762 ssh->exhash = ssh->kex->hash->init();
6763 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6764 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6765 hash_string(ssh->kex->hash, ssh->exhash,
6766 s->our_kexinit, s->our_kexinitlen);
6767 sfree(s->our_kexinit);
6768 /* Include the type byte in the hash of server's KEXINIT */
6769 hash_string(ssh->kex->hash, ssh->exhash,
6770 pktin->body - 1, pktin->length + 1);
6773 ssh_set_frozen(ssh, 1);
6774 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6776 ssh_dialog_callback, ssh);
6777 if (s->dlgret < 0) {
6781 bombout(("Unexpected data from server while"
6782 " waiting for user response"));
6785 } while (pktin || inlen > 0);
6786 s->dlgret = ssh->user_response;
6788 ssh_set_frozen(ssh, 0);
6789 if (s->dlgret == 0) {
6790 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6800 ssh_set_frozen(ssh, 1);
6803 * Change warning box wording depending on why we chose a
6804 * warning-level host key algorithm. If it's because
6805 * that's all we have *cached*, use the askhk mechanism,
6806 * and list the host keys we could usefully cross-certify.
6807 * Otherwise, use askalg for the standard wording.
6810 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6811 const struct ssh_signkey_with_user_pref_id *hktype =
6812 &hostkey_algs[ssh->uncert_hostkeys[j]];
6814 for (k = 0; k < HK_MAX; k++) {
6815 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6816 if (id == HK_WARN) {
6818 } else if (id == hktype->id) {
6825 char *old_ba = betteralgs;
6826 betteralgs = dupcat(betteralgs, ",",
6828 (const char *)NULL);
6831 betteralgs = dupstr(hktype->alg->name);
6836 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6837 betteralgs, ssh_dialog_callback, ssh);
6840 s->dlgret = askalg(ssh->frontend, "host key type",
6842 ssh_dialog_callback, ssh);
6844 if (s->dlgret < 0) {
6848 bombout(("Unexpected data from server while"
6849 " waiting for user response"));
6852 } while (pktin || inlen > 0);
6853 s->dlgret = ssh->user_response;
6855 ssh_set_frozen(ssh, 0);
6856 if (s->dlgret == 0) {
6857 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6863 if (s->warn_cscipher) {
6864 ssh_set_frozen(ssh, 1);
6865 s->dlgret = askalg(ssh->frontend,
6866 "client-to-server cipher",
6867 s->cscipher_tobe->name,
6868 ssh_dialog_callback, ssh);
6869 if (s->dlgret < 0) {
6873 bombout(("Unexpected data from server while"
6874 " waiting for user response"));
6877 } while (pktin || inlen > 0);
6878 s->dlgret = ssh->user_response;
6880 ssh_set_frozen(ssh, 0);
6881 if (s->dlgret == 0) {
6882 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6888 if (s->warn_sccipher) {
6889 ssh_set_frozen(ssh, 1);
6890 s->dlgret = askalg(ssh->frontend,
6891 "server-to-client cipher",
6892 s->sccipher_tobe->name,
6893 ssh_dialog_callback, ssh);
6894 if (s->dlgret < 0) {
6898 bombout(("Unexpected data from server while"
6899 " waiting for user response"));
6902 } while (pktin || inlen > 0);
6903 s->dlgret = ssh->user_response;
6905 ssh_set_frozen(ssh, 0);
6906 if (s->dlgret == 0) {
6907 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6913 if (s->ignorepkt) /* first_kex_packet_follows */
6914 crWaitUntilV(pktin); /* Ignore packet */
6917 if (ssh->kex->main_type == KEXTYPE_DH) {
6919 * Work out the number of bits of key we will need from the
6920 * key exchange. We start with the maximum key length of
6926 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6927 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6928 s->nbits = (csbits > scbits ? csbits : scbits);
6930 /* The keys only have hlen-bit entropy, since they're based on
6931 * a hash. So cap the key size at hlen bits. */
6932 if (s->nbits > ssh->kex->hash->hlen * 8)
6933 s->nbits = ssh->kex->hash->hlen * 8;
6936 * If we're doing Diffie-Hellman group exchange, start by
6937 * requesting a group.
6939 if (dh_is_gex(ssh->kex)) {
6940 logevent("Doing Diffie-Hellman group exchange");
6941 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6943 * Work out how big a DH group we will need to allow that
6946 s->pbits = 512 << ((s->nbits - 1) / 64);
6947 if (s->pbits < DH_MIN_SIZE)
6948 s->pbits = DH_MIN_SIZE;
6949 if (s->pbits > DH_MAX_SIZE)
6950 s->pbits = DH_MAX_SIZE;
6951 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6952 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6953 ssh2_pkt_adduint32(s->pktout, s->pbits);
6955 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6956 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6957 ssh2_pkt_adduint32(s->pktout, s->pbits);
6958 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6960 ssh2_pkt_send_noqueue(ssh, s->pktout);
6962 crWaitUntilV(pktin);
6963 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6964 bombout(("expected key exchange group packet from server"));
6967 s->p = ssh2_pkt_getmp(pktin);
6968 s->g = ssh2_pkt_getmp(pktin);
6969 if (!s->p || !s->g) {
6970 bombout(("unable to read mp-ints from incoming group packet"));
6973 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6974 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6975 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6977 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6978 ssh->kex_ctx = dh_setup_group(ssh->kex);
6979 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6980 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6981 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6982 ssh->kex->groupname);
6985 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6986 ssh->kex->hash->text_name);
6988 * Now generate and send e for Diffie-Hellman.
6990 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6991 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6992 s->pktout = ssh2_pkt_init(s->kex_init_value);
6993 ssh2_pkt_addmp(s->pktout, s->e);
6994 ssh2_pkt_send_noqueue(ssh, s->pktout);
6996 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6997 crWaitUntilV(pktin);
6998 if (pktin->type != s->kex_reply_value) {
6999 bombout(("expected key exchange reply packet from server"));
7002 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
7003 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7004 if (!s->hostkeydata) {
7005 bombout(("unable to parse key exchange reply packet"));
7008 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7009 s->hostkeydata, s->hostkeylen);
7010 s->f = ssh2_pkt_getmp(pktin);
7012 bombout(("unable to parse key exchange reply packet"));
7015 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7017 bombout(("unable to parse key exchange reply packet"));
7022 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7024 bombout(("key exchange reply failed validation: %s", err));
7028 s->K = dh_find_K(ssh->kex_ctx, s->f);
7030 /* We assume everything from now on will be quick, and it might
7031 * involve user interaction. */
7032 set_busy_status(ssh->frontend, BUSY_NOT);
7034 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7035 if (dh_is_gex(ssh->kex)) {
7036 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7037 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7038 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7039 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7040 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7041 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7042 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7044 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7045 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7047 dh_cleanup(ssh->kex_ctx);
7049 if (dh_is_gex(ssh->kex)) {
7053 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7055 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7056 ssh_ecdhkex_curve_textname(ssh->kex),
7057 ssh->kex->hash->text_name);
7058 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7060 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7062 bombout(("Unable to generate key for ECDH"));
7068 int publicPointLength;
7069 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7071 ssh_ecdhkex_freekey(s->eckey);
7072 bombout(("Unable to encode public key for ECDH"));
7075 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7076 ssh2_pkt_addstring_start(s->pktout);
7077 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7081 ssh2_pkt_send_noqueue(ssh, s->pktout);
7083 crWaitUntilV(pktin);
7084 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7085 ssh_ecdhkex_freekey(s->eckey);
7086 bombout(("expected ECDH reply packet from server"));
7090 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7091 if (!s->hostkeydata) {
7092 bombout(("unable to parse ECDH reply packet"));
7095 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7096 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7097 s->hostkeydata, s->hostkeylen);
7101 int publicPointLength;
7102 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7104 ssh_ecdhkex_freekey(s->eckey);
7105 bombout(("Unable to encode public key for ECDH hash"));
7108 hash_string(ssh->kex->hash, ssh->exhash,
7109 publicPoint, publicPointLength);
7116 ssh_pkt_getstring(pktin, &keydata, &keylen);
7118 bombout(("unable to parse ECDH reply packet"));
7121 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7122 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7124 ssh_ecdhkex_freekey(s->eckey);
7125 bombout(("point received in ECDH was not valid"));
7130 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7132 bombout(("unable to parse key exchange reply packet"));
7136 ssh_ecdhkex_freekey(s->eckey);
7138 logeventf(ssh, "Doing RSA key exchange with hash %s",
7139 ssh->kex->hash->text_name);
7140 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7142 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7145 crWaitUntilV(pktin);
7146 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7147 bombout(("expected RSA public key packet from server"));
7151 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7152 if (!s->hostkeydata) {
7153 bombout(("unable to parse RSA public key packet"));
7156 hash_string(ssh->kex->hash, ssh->exhash,
7157 s->hostkeydata, s->hostkeylen);
7158 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7159 s->hostkeydata, s->hostkeylen);
7163 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7165 bombout(("unable to parse RSA public key packet"));
7168 s->rsakeydata = snewn(s->rsakeylen, char);
7169 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7172 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7174 sfree(s->rsakeydata);
7175 bombout(("unable to parse RSA public key from server"));
7179 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7182 * Next, set up a shared secret K, of precisely KLEN -
7183 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7184 * RSA key modulus and HLEN is the bit length of the hash
7188 int klen = ssh_rsakex_klen(s->rsakey);
7189 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7191 unsigned char *kstr1, *kstr2, *outstr;
7192 int kstr1len, kstr2len, outstrlen;
7194 s->K = bn_power_2(nbits - 1);
7196 for (i = 0; i < nbits; i++) {
7198 byte = random_byte();
7200 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7204 * Encode this as an mpint.
7206 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7207 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7208 PUT_32BIT(kstr2, kstr1len);
7209 memcpy(kstr2 + 4, kstr1, kstr1len);
7212 * Encrypt it with the given RSA key.
7214 outstrlen = (klen + 7) / 8;
7215 outstr = snewn(outstrlen, unsigned char);
7216 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7217 outstr, outstrlen, s->rsakey);
7220 * And send it off in a return packet.
7222 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7223 ssh2_pkt_addstring_start(s->pktout);
7224 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7225 ssh2_pkt_send_noqueue(ssh, s->pktout);
7227 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7234 ssh_rsakex_freekey(s->rsakey);
7236 crWaitUntilV(pktin);
7237 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7238 sfree(s->rsakeydata);
7239 bombout(("expected signature packet from server"));
7243 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7245 bombout(("unable to parse signature packet"));
7249 sfree(s->rsakeydata);
7252 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7253 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7254 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7256 ssh->kex_ctx = NULL;
7259 debug(("Exchange hash is:\n"));
7260 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7264 bombout(("Server's host key is invalid"));
7268 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7269 (char *)s->exchange_hash,
7270 ssh->kex->hash->hlen)) {
7272 bombout(("Server's host key did not match the signature supplied"));
7277 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7278 if (!s->got_session_id) {
7280 * Make a note of any other host key formats that are available.
7283 int i, j, nkeys = 0;
7285 for (i = 0; i < lenof(hostkey_algs); i++) {
7286 if (hostkey_algs[i].alg == ssh->hostkey)
7289 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7290 if (ssh->uncert_hostkeys[j] == i)
7293 if (j < ssh->n_uncert_hostkeys) {
7296 newlist = dupprintf("%s/%s", list,
7297 hostkey_algs[i].alg->name);
7299 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7307 "Server also has %s host key%s, but we "
7308 "don't know %s", list,
7309 nkeys > 1 ? "s" : "",
7310 nkeys > 1 ? "any of them" : "it");
7316 * Authenticate remote host: verify host key. (We've already
7317 * checked the signature of the exchange hash.)
7319 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7320 logevent("Host key fingerprint is:");
7321 logevent(s->fingerprint);
7322 /* First check against manually configured host keys. */
7323 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7324 ssh->hostkey, s->hkey);
7325 if (s->dlgret == 0) { /* did not match */
7326 bombout(("Host key did not appear in manually configured list"));
7328 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7329 ssh_set_frozen(ssh, 1);
7330 s->dlgret = verify_ssh_host_key(ssh->frontend,
7331 ssh->savedhost, ssh->savedport,
7332 ssh->hostkey->keytype, s->keystr,
7334 ssh_dialog_callback, ssh);
7338 if (s->dlgret < 0) {
7342 bombout(("Unexpected data from server while waiting"
7343 " for user host key response"));
7346 } while (pktin || inlen > 0);
7347 s->dlgret = ssh->user_response;
7349 ssh_set_frozen(ssh, 0);
7350 if (s->dlgret == 0) {
7351 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7356 sfree(s->fingerprint);
7358 * Save this host key, to check against the one presented in
7359 * subsequent rekeys.
7361 ssh->hostkey_str = s->keystr;
7362 } else if (ssh->cross_certifying) {
7363 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7364 logevent("Storing additional host key for this host:");
7365 logevent(s->fingerprint);
7366 store_host_key(ssh->savedhost, ssh->savedport,
7367 ssh->hostkey->keytype, s->keystr);
7368 ssh->cross_certifying = FALSE;
7370 * Don't forget to store the new key as the one we'll be
7371 * re-checking in future normal rekeys.
7373 ssh->hostkey_str = s->keystr;
7376 * In a rekey, we never present an interactive host key
7377 * verification request to the user. Instead, we simply
7378 * enforce that the key we're seeing this time is identical to
7379 * the one we saw before.
7381 if (strcmp(ssh->hostkey_str, s->keystr)) {
7383 bombout(("Host key was different in repeat key exchange"));
7389 ssh->hostkey->freekey(s->hkey);
7392 * The exchange hash from the very first key exchange is also
7393 * the session id, used in session key construction and
7396 if (!s->got_session_id) {
7397 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7398 memcpy(ssh->v2_session_id, s->exchange_hash,
7399 sizeof(s->exchange_hash));
7400 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7401 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7402 s->got_session_id = TRUE;
7406 * Send SSH2_MSG_NEWKEYS.
7408 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7409 ssh2_pkt_send_noqueue(ssh, s->pktout);
7410 ssh->outgoing_data_size = 0; /* start counting from here */
7413 * We've sent client NEWKEYS, so create and initialise
7414 * client-to-server session keys.
7416 if (ssh->cs_cipher_ctx)
7417 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7418 ssh->cscipher = s->cscipher_tobe;
7419 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7421 if (ssh->cs_mac_ctx)
7422 ssh->csmac->free_context(ssh->cs_mac_ctx);
7423 ssh->csmac = s->csmac_tobe;
7424 ssh->csmac_etm = s->csmac_etm_tobe;
7426 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7428 if (ssh->cs_comp_ctx)
7429 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7430 ssh->cscomp = s->cscomp_tobe;
7431 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7434 * Set IVs on client-to-server keys. Here we use the exchange
7435 * hash from the _first_ key exchange.
7437 if (ssh->cscipher) {
7440 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7441 ssh->cscipher->padded_keybytes);
7442 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7443 smemclr(key, ssh->cscipher->padded_keybytes);
7446 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7447 ssh->cscipher->blksize);
7448 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7449 smemclr(key, ssh->cscipher->blksize);
7455 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7456 ssh->csmac->keylen);
7457 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7458 smemclr(key, ssh->csmac->keylen);
7463 logeventf(ssh, "Initialised %.200s client->server encryption",
7464 ssh->cscipher->text_name);
7466 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7467 ssh->csmac->text_name,
7468 ssh->csmac_etm ? " (in ETM mode)" : "",
7469 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7470 if (ssh->cscomp->text_name)
7471 logeventf(ssh, "Initialised %s compression",
7472 ssh->cscomp->text_name);
7475 * Now our end of the key exchange is complete, we can send all
7476 * our queued higher-layer packets.
7478 ssh->queueing = FALSE;
7479 ssh2_pkt_queuesend(ssh);
7482 * Expect SSH2_MSG_NEWKEYS from server.
7484 crWaitUntilV(pktin);
7485 if (pktin->type != SSH2_MSG_NEWKEYS) {
7486 bombout(("expected new-keys packet from server"));
7489 ssh->incoming_data_size = 0; /* start counting from here */
7492 * We've seen server NEWKEYS, so create and initialise
7493 * server-to-client session keys.
7495 if (ssh->sc_cipher_ctx)
7496 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7497 if (s->sccipher_tobe) {
7498 ssh->sccipher = s->sccipher_tobe;
7499 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7502 if (ssh->sc_mac_ctx)
7503 ssh->scmac->free_context(ssh->sc_mac_ctx);
7504 if (s->scmac_tobe) {
7505 ssh->scmac = s->scmac_tobe;
7506 ssh->scmac_etm = s->scmac_etm_tobe;
7507 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7510 if (ssh->sc_comp_ctx)
7511 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7512 ssh->sccomp = s->sccomp_tobe;
7513 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7516 * Set IVs on server-to-client keys. Here we use the exchange
7517 * hash from the _first_ key exchange.
7519 if (ssh->sccipher) {
7522 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7523 ssh->sccipher->padded_keybytes);
7524 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7525 smemclr(key, ssh->sccipher->padded_keybytes);
7528 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7529 ssh->sccipher->blksize);
7530 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7531 smemclr(key, ssh->sccipher->blksize);
7537 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7538 ssh->scmac->keylen);
7539 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7540 smemclr(key, ssh->scmac->keylen);
7544 logeventf(ssh, "Initialised %.200s server->client encryption",
7545 ssh->sccipher->text_name);
7547 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7548 ssh->scmac->text_name,
7549 ssh->scmac_etm ? " (in ETM mode)" : "",
7550 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7551 if (ssh->sccomp->text_name)
7552 logeventf(ssh, "Initialised %s decompression",
7553 ssh->sccomp->text_name);
7556 * Free shared secret.
7561 * Update the specials menu to list the remaining uncertified host
7564 update_specials_menu(ssh->frontend);
7567 * Key exchange is over. Loop straight back round if we have a
7568 * deferred rekey reason.
7570 if (ssh->deferred_rekey_reason) {
7571 logevent(ssh->deferred_rekey_reason);
7573 ssh->deferred_rekey_reason = NULL;
7574 goto begin_key_exchange;
7578 * Otherwise, schedule a timer for our next rekey.
7580 ssh->kex_in_progress = FALSE;
7581 ssh->last_rekey = GETTICKCOUNT();
7582 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7583 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7587 * Now we're encrypting. Begin returning 1 to the protocol main
7588 * function so that other things can run on top of the
7589 * transport. If we ever see a KEXINIT, we must go back to the
7592 * We _also_ go back to the start if we see pktin==NULL and
7593 * inlen negative, because this is a special signal meaning
7594 * `initiate client-driven rekey', and `in' contains a message
7595 * giving the reason for the rekey.
7597 * inlen==-1 means always initiate a rekey;
7598 * inlen==-2 means that userauth has completed successfully and
7599 * we should consider rekeying (for delayed compression).
7601 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7602 (!pktin && inlen < 0))) {
7604 if (!ssh->protocol_initial_phase_done) {
7605 ssh->protocol_initial_phase_done = TRUE;
7607 * Allow authconn to initialise itself.
7609 do_ssh2_authconn(ssh, NULL, 0, NULL);
7614 logevent("Server initiated key re-exchange");
7618 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7619 * delayed compression, if it's available.
7621 * draft-miller-secsh-compression-delayed-00 says that you
7622 * negotiate delayed compression in the first key exchange, and
7623 * both sides start compressing when the server has sent
7624 * USERAUTH_SUCCESS. This has a race condition -- the server
7625 * can't know when the client has seen it, and thus which incoming
7626 * packets it should treat as compressed.
7628 * Instead, we do the initial key exchange without offering the
7629 * delayed methods, but note if the server offers them; when we
7630 * get here, if a delayed method was available that was higher
7631 * on our list than what we got, we initiate a rekey in which we
7632 * _do_ list the delayed methods (and hopefully get it as a
7633 * result). Subsequent rekeys will do the same.
7635 assert(!s->userauth_succeeded); /* should only happen once */
7636 s->userauth_succeeded = TRUE;
7637 if (!s->pending_compression)
7638 /* Can't see any point rekeying. */
7639 goto wait_for_rekey; /* this is utterly horrid */
7640 /* else fall through to rekey... */
7641 s->pending_compression = FALSE;
7644 * Now we've decided to rekey.
7646 * Special case: if the server bug is set that doesn't
7647 * allow rekeying, we give a different log message and
7648 * continue waiting. (If such a server _initiates_ a rekey,
7649 * we process it anyway!)
7651 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7652 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7654 /* Reset the counters, so that at least this message doesn't
7655 * hit the event log _too_ often. */
7656 ssh->outgoing_data_size = 0;
7657 ssh->incoming_data_size = 0;
7658 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7660 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7663 goto wait_for_rekey; /* this is still utterly horrid */
7665 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7668 goto begin_key_exchange;
7674 * Send data on an SSH channel. In SSH-2, this involves buffering it
7677 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7680 if (c->ssh->version == 2) {
7681 bufchain_add(&c->v.v2.outbuffer, buf, len);
7682 return ssh2_try_send(c);
7684 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7685 PKT_INT, c->remoteid,
7690 * In SSH-1 we can return 0 here - implying that channels are
7691 * never individually throttled - because the only
7692 * circumstance that can cause throttling will be the whole
7693 * SSH connection backing up, in which case _everything_ will
7694 * be throttled as a whole.
7701 * Attempt to send data on an SSH-2 channel.
7703 static int ssh2_try_send(struct ssh_channel *c)
7706 struct Packet *pktout;
7709 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7712 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7713 if ((unsigned)len > c->v.v2.remwindow)
7714 len = c->v.v2.remwindow;
7715 if ((unsigned)len > c->v.v2.remmaxpkt)
7716 len = c->v.v2.remmaxpkt;
7717 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7718 ssh2_pkt_adduint32(pktout, c->remoteid);
7719 ssh2_pkt_addstring_start(pktout);
7720 ssh2_pkt_addstring_data(pktout, data, len);
7721 ssh2_pkt_send(ssh, pktout);
7722 bufchain_consume(&c->v.v2.outbuffer, len);
7723 c->v.v2.remwindow -= len;
7727 * After having sent as much data as we can, return the amount
7730 ret = bufchain_size(&c->v.v2.outbuffer);
7733 * And if there's no data pending but we need to send an EOF, send
7736 if (!ret && c->pending_eof)
7737 ssh_channel_try_eof(c);
7742 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7745 if (c->closes & CLOSES_SENT_EOF)
7746 return; /* don't send on channels we've EOFed */
7747 bufsize = ssh2_try_send(c);
7750 case CHAN_MAINSESSION:
7751 /* stdin need not receive an unthrottle
7752 * notification since it will be polled */
7755 x11_unthrottle(c->u.x11.xconn);
7758 /* agent sockets are request/response and need no
7759 * buffer management */
7762 pfd_unthrottle(c->u.pfd.pf);
7768 static int ssh_is_simple(Ssh ssh)
7771 * We use the 'simple' variant of the SSH protocol if we're asked
7772 * to, except not if we're also doing connection-sharing (either
7773 * tunnelling our packets over an upstream or expecting to be
7774 * tunnelled over ourselves), since then the assumption that we
7775 * have only one channel to worry about is not true after all.
7777 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7778 !ssh->bare_connection && !ssh->connshare);
7782 * Set up most of a new ssh_channel.
7784 static void ssh_channel_init(struct ssh_channel *c)
7787 c->localid = alloc_channel_id(ssh);
7789 c->pending_eof = FALSE;
7790 c->throttling_conn = FALSE;
7791 if (ssh->version == 2) {
7792 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7793 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7794 c->v.v2.chanreq_head = NULL;
7795 c->v.v2.throttle_state = UNTHROTTLED;
7796 bufchain_init(&c->v.v2.outbuffer);
7798 add234(ssh->channels, c);
7802 * Construct the common parts of a CHANNEL_OPEN.
7804 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7807 struct Packet *pktout;
7809 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7810 ssh2_pkt_addstring(pktout, type);
7811 ssh2_pkt_adduint32(pktout, c->localid);
7812 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7813 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7818 * CHANNEL_FAILURE doesn't come with any indication of what message
7819 * caused it, so we have to keep track of the outstanding
7820 * CHANNEL_REQUESTs ourselves.
7822 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7823 cchandler_fn_t handler, void *ctx)
7825 struct outstanding_channel_request *ocr =
7826 snew(struct outstanding_channel_request);
7828 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7829 ocr->handler = handler;
7832 if (!c->v.v2.chanreq_head)
7833 c->v.v2.chanreq_head = ocr;
7835 c->v.v2.chanreq_tail->next = ocr;
7836 c->v.v2.chanreq_tail = ocr;
7840 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7841 * NULL then a reply will be requested and the handler will be called
7842 * when it arrives. The returned packet is ready to have any
7843 * request-specific data added and be sent. Note that if a handler is
7844 * provided, it's essential that the request actually be sent.
7846 * The handler will usually be passed the response packet in pktin. If
7847 * pktin is NULL, this means that no reply will ever be forthcoming
7848 * (e.g. because the entire connection is being destroyed, or because
7849 * the server initiated channel closure before we saw the response)
7850 * and the handler should free any storage it's holding.
7852 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7854 cchandler_fn_t handler, void *ctx)
7856 struct Packet *pktout;
7858 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7859 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7860 ssh2_pkt_adduint32(pktout, c->remoteid);
7861 ssh2_pkt_addstring(pktout, type);
7862 ssh2_pkt_addbool(pktout, handler != NULL);
7863 if (handler != NULL)
7864 ssh2_queue_chanreq_handler(c, handler, ctx);
7868 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize)
7873 if (ssh->version == 1) {
7874 buflimit = SSH1_BUFFER_LIMIT;
7876 if (ssh_is_simple(ssh))
7879 buflimit = c->v.v2.locmaxwin;
7880 if (bufsize < buflimit)
7881 ssh2_set_window(c, buflimit - bufsize);
7883 if (c->throttling_conn && bufsize <= buflimit) {
7884 c->throttling_conn = 0;
7885 ssh_throttle_conn(ssh, -1);
7890 * Potentially enlarge the window on an SSH-2 channel.
7892 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7894 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7899 * Never send WINDOW_ADJUST for a channel that the remote side has
7900 * already sent EOF on; there's no point, since it won't be
7901 * sending any more data anyway. Ditto if _we've_ already sent
7904 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7908 * Also, never widen the window for an X11 channel when we're
7909 * still waiting to see its initial auth and may yet hand it off
7912 if (c->type == CHAN_X11 && c->u.x11.initial)
7916 * If the remote end has a habit of ignoring maxpkt, limit the
7917 * window so that it has no choice (assuming it doesn't ignore the
7920 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7921 newwin = OUR_V2_MAXPKT;
7924 * Only send a WINDOW_ADJUST if there's significantly more window
7925 * available than the other end thinks there is. This saves us
7926 * sending a WINDOW_ADJUST for every character in a shell session.
7928 * "Significant" is arbitrarily defined as half the window size.
7930 if (newwin / 2 >= c->v.v2.locwindow) {
7931 struct Packet *pktout;
7935 * In order to keep track of how much window the client
7936 * actually has available, we'd like it to acknowledge each
7937 * WINDOW_ADJUST. We can't do that directly, so we accompany
7938 * it with a CHANNEL_REQUEST that has to be acknowledged.
7940 * This is only necessary if we're opening the window wide.
7941 * If we're not, then throughput is being constrained by
7942 * something other than the maximum window size anyway.
7944 if (newwin == c->v.v2.locmaxwin &&
7945 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7946 up = snew(unsigned);
7947 *up = newwin - c->v.v2.locwindow;
7948 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7949 ssh2_handle_winadj_response, up);
7950 ssh2_pkt_send(ssh, pktout);
7952 if (c->v.v2.throttle_state != UNTHROTTLED)
7953 c->v.v2.throttle_state = UNTHROTTLING;
7955 /* Pretend the WINDOW_ADJUST was acked immediately. */
7956 c->v.v2.remlocwin = newwin;
7957 c->v.v2.throttle_state = THROTTLED;
7959 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7960 ssh2_pkt_adduint32(pktout, c->remoteid);
7961 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7962 ssh2_pkt_send(ssh, pktout);
7963 c->v.v2.locwindow = newwin;
7968 * Find the channel associated with a message. If there's no channel,
7969 * or it's not properly open, make a noise about it and return NULL.
7970 * If the channel is shared, pass the message on to downstream and
7971 * also return NULL (meaning the caller should ignore this message).
7973 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin)
7975 unsigned localid = ssh_pkt_getuint32(pktin);
7976 struct ssh_channel *c;
7979 /* Is this message OK on a half-open connection? */
7980 if (ssh->version == 1)
7981 halfopen_ok = (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION ||
7982 pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE);
7984 halfopen_ok = (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION ||
7985 pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE);
7986 c = find234(ssh->channels, &localid, ssh_channelfind);
7987 if (!c || (c->type != CHAN_SHARING && (c->halfopen != halfopen_ok))) {
7988 char *buf = dupprintf("Received %s for %s channel %u",
7989 ssh_pkt_type(ssh, pktin->type),
7990 !c ? "nonexistent" :
7991 c->halfopen ? "half-open" : "open",
7993 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7997 if (c->type == CHAN_SHARING) {
7998 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7999 pktin->body, pktin->length);
8005 static void ssh2_handle_winadj_response(struct ssh_channel *c,
8006 struct Packet *pktin, void *ctx)
8008 unsigned *sizep = ctx;
8011 * Winadj responses should always be failures. However, at least
8012 * one server ("boks_sshd") is known to return SUCCESS for channel
8013 * requests it's never heard of, such as "winadj@putty". Raised
8014 * with foxt.com as bug 090916-090424, but for the sake of a quiet
8015 * life, we don't worry about what kind of response we got.
8018 c->v.v2.remlocwin += *sizep;
8021 * winadj messages are only sent when the window is fully open, so
8022 * if we get an ack of one, we know any pending unthrottle is
8025 if (c->v.v2.throttle_state == UNTHROTTLING)
8026 c->v.v2.throttle_state = UNTHROTTLED;
8029 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
8031 struct ssh_channel *c = ssh_channel_msg(ssh, pktin);
8032 struct outstanding_channel_request *ocr;
8035 ocr = c->v.v2.chanreq_head;
8037 ssh2_msg_unexpected(ssh, pktin);
8040 ocr->handler(c, pktin, ocr->ctx);
8041 c->v.v2.chanreq_head = ocr->next;
8044 * We may now initiate channel-closing procedures, if that
8045 * CHANNEL_REQUEST was the last thing outstanding before we send
8048 ssh2_channel_check_close(c);
8051 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8053 struct ssh_channel *c;
8054 c = ssh_channel_msg(ssh, pktin);
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 unsigned ext_type = 0; /* 0 means not extended */
8068 struct ssh_channel *c;
8069 c = ssh_channel_msg(ssh, pktin);
8072 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
8073 ext_type = ssh_pkt_getuint32(pktin);
8074 ssh_pkt_getstring(pktin, &data, &length);
8077 c->v.v2.locwindow -= length;
8078 c->v.v2.remlocwin -= length;
8079 if (ext_type != 0 && ext_type != SSH2_EXTENDED_DATA_STDERR)
8080 length = 0; /* Don't do anything with unknown extended data. */
8081 bufsize = ssh_channel_data(c, ext_type == SSH2_EXTENDED_DATA_STDERR,
8084 * If it looks like the remote end hit the end of its window,
8085 * and we didn't want it to do that, think about using a
8088 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8089 c->v.v2.locmaxwin < 0x40000000)
8090 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8092 * If we are not buffering too much data,
8093 * enlarge the window again at the remote side.
8094 * If we are buffering too much, we may still
8095 * need to adjust the window if the server's
8098 if (bufsize < c->v.v2.locmaxwin)
8099 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
8101 * If we're either buffering way too much data, or if we're
8102 * buffering anything at all and we're in "simple" mode,
8103 * throttle the whole channel.
8105 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8106 && !c->throttling_conn) {
8107 c->throttling_conn = 1;
8108 ssh_throttle_conn(ssh, +1);
8113 static void ssh_check_termination(Ssh ssh)
8115 if (ssh->version == 2 &&
8116 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8117 (ssh->channels && count234(ssh->channels) == 0) &&
8118 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8120 * We used to send SSH_MSG_DISCONNECT here, because I'd
8121 * believed that _every_ conforming SSH-2 connection had to
8122 * end with a disconnect being sent by at least one side;
8123 * apparently I was wrong and it's perfectly OK to
8124 * unceremoniously slam the connection shut when you're done,
8125 * and indeed OpenSSH feels this is more polite than sending a
8126 * DISCONNECT. So now we don't.
8128 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8132 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8133 const char *peerinfo)
8136 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8139 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8142 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8144 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8145 ssh_check_termination(ssh);
8148 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8153 va_start(ap, logfmt);
8154 buf = dupvprintf(logfmt, ap);
8157 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8159 logeventf(ssh, "Connection sharing: %s", buf);
8163 static void ssh_channel_destroy(struct ssh_channel *c)
8168 case CHAN_MAINSESSION:
8169 ssh->mainchan = NULL;
8170 update_specials_menu(ssh->frontend);
8173 if (c->u.x11.xconn != NULL)
8174 x11_close(c->u.x11.xconn);
8175 logevent("Forwarded X11 connection terminated");
8178 sfree(c->u.a.message);
8181 if (c->u.pfd.pf != NULL)
8182 pfd_close(c->u.pfd.pf);
8183 logevent("Forwarded port closed");
8187 del234(ssh->channels, c);
8188 if (ssh->version == 2) {
8189 bufchain_clear(&c->v.v2.outbuffer);
8190 assert(c->v.v2.chanreq_head == NULL);
8195 * If that was the last channel left open, we might need to
8198 ssh_check_termination(ssh);
8201 static void ssh2_channel_check_close(struct ssh_channel *c)
8204 struct Packet *pktout;
8206 assert(ssh->version == 2);
8209 * If we've sent out our own CHANNEL_OPEN but not yet seen
8210 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8211 * it's too early to be sending close messages of any kind.
8216 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8217 c->type == CHAN_ZOMBIE) &&
8218 !c->v.v2.chanreq_head &&
8219 !(c->closes & CLOSES_SENT_CLOSE)) {
8221 * We have both sent and received EOF (or the channel is a
8222 * zombie), and we have no outstanding channel requests, which
8223 * means the channel is in final wind-up. But we haven't sent
8224 * CLOSE, so let's do so now.
8226 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8227 ssh2_pkt_adduint32(pktout, c->remoteid);
8228 ssh2_pkt_send(ssh, pktout);
8229 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8232 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8233 assert(c->v.v2.chanreq_head == NULL);
8235 * We have both sent and received CLOSE, which means we're
8236 * completely done with the channel.
8238 ssh_channel_destroy(c);
8242 static void ssh2_channel_got_eof(struct ssh_channel *c)
8244 if (c->closes & CLOSES_RCVD_EOF)
8245 return; /* already seen EOF */
8246 c->closes |= CLOSES_RCVD_EOF;
8248 if (c->type == CHAN_X11) {
8249 x11_send_eof(c->u.x11.xconn);
8250 } else if (c->type == CHAN_AGENT) {
8251 if (c->u.a.outstanding_requests == 0) {
8252 /* Manufacture an outgoing EOF in response to the incoming one. */
8253 sshfwd_write_eof(c);
8255 } else if (c->type == CHAN_SOCKDATA) {
8256 pfd_send_eof(c->u.pfd.pf);
8257 } else if (c->type == CHAN_MAINSESSION) {
8260 if (!ssh->sent_console_eof &&
8261 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8263 * Either from_backend_eof told us that the front end
8264 * wants us to close the outgoing side of the connection
8265 * as soon as we see EOF from the far end, or else we've
8266 * unilaterally decided to do that because we've allocated
8267 * a remote pty and hence EOF isn't a particularly
8268 * meaningful concept.
8270 sshfwd_write_eof(c);
8272 ssh->sent_console_eof = TRUE;
8275 ssh2_channel_check_close(c);
8278 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8280 struct ssh_channel *c;
8282 c = ssh_channel_msg(ssh, pktin);
8285 ssh2_channel_got_eof(c);
8288 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8290 struct ssh_channel *c;
8292 c = ssh_channel_msg(ssh, pktin);
8297 * When we receive CLOSE on a channel, we assume it comes with an
8298 * implied EOF if we haven't seen EOF yet.
8300 ssh2_channel_got_eof(c);
8302 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8304 * It also means we stop expecting to see replies to any
8305 * outstanding channel requests, so clean those up too.
8306 * (ssh_chanreq_init will enforce by assertion that we don't
8307 * subsequently put anything back on this list.)
8309 while (c->v.v2.chanreq_head) {
8310 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8311 ocr->handler(c, NULL, ocr->ctx);
8312 c->v.v2.chanreq_head = ocr->next;
8318 * And we also send an outgoing EOF, if we haven't already, on the
8319 * assumption that CLOSE is a pretty forceful announcement that
8320 * the remote side is doing away with the entire channel. (If it
8321 * had wanted to send us EOF and continue receiving data from us,
8322 * it would have just sent CHANNEL_EOF.)
8324 if (!(c->closes & CLOSES_SENT_EOF)) {
8326 * Make sure we don't read any more from whatever our local
8327 * data source is for this channel.
8330 case CHAN_MAINSESSION:
8331 ssh->send_ok = 0; /* stop trying to read from stdin */
8334 x11_override_throttle(c->u.x11.xconn, 1);
8337 pfd_override_throttle(c->u.pfd.pf, 1);
8342 * Abandon any buffered data we still wanted to send to this
8343 * channel. Receiving a CHANNEL_CLOSE is an indication that
8344 * the server really wants to get on and _destroy_ this
8345 * channel, and it isn't going to send us any further
8346 * WINDOW_ADJUSTs to permit us to send pending stuff.
8348 bufchain_clear(&c->v.v2.outbuffer);
8351 * Send outgoing EOF.
8353 sshfwd_write_eof(c);
8357 * Now process the actual close.
8359 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8360 c->closes |= CLOSES_RCVD_CLOSE;
8361 ssh2_channel_check_close(c);
8365 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8367 struct ssh_channel *c;
8369 c = ssh_channel_msg(ssh, pktin);
8372 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8373 c->remoteid = ssh_pkt_getuint32(pktin);
8374 c->halfopen = FALSE;
8375 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8376 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8378 if (c->type == CHAN_SOCKDATA) {
8380 pfd_confirm(c->u.pfd.pf);
8381 } else if (c->type == CHAN_ZOMBIE) {
8383 * This case can occur if a local socket error occurred
8384 * between us sending out CHANNEL_OPEN and receiving
8385 * OPEN_CONFIRMATION. In this case, all we can do is
8386 * immediately initiate close proceedings now that we know the
8387 * server's id to put in the close message.
8389 ssh2_channel_check_close(c);
8392 * We never expect to receive OPEN_CONFIRMATION for any
8393 * *other* channel type (since only local-to-remote port
8394 * forwardings cause us to send CHANNEL_OPEN after the main
8395 * channel is live - all other auxiliary channel types are
8396 * initiated from the server end). It's safe to enforce this
8397 * by assertion rather than by ssh_disconnect, because the
8398 * real point is that we never constructed a half-open channel
8399 * structure in the first place with any type other than the
8402 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8406 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8409 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8411 static const char *const reasons[] = {
8412 "<unknown reason code>",
8413 "Administratively prohibited",
8415 "Unknown channel type",
8416 "Resource shortage",
8418 unsigned reason_code;
8419 char *reason_string;
8421 struct ssh_channel *c;
8423 c = ssh_channel_msg(ssh, pktin);
8426 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8428 if (c->type == CHAN_SOCKDATA) {
8429 reason_code = ssh_pkt_getuint32(pktin);
8430 if (reason_code >= lenof(reasons))
8431 reason_code = 0; /* ensure reasons[reason_code] in range */
8432 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8433 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8434 reasons[reason_code], reason_length,
8435 NULLTOEMPTY(reason_string));
8437 pfd_close(c->u.pfd.pf);
8438 } else if (c->type == CHAN_ZOMBIE) {
8440 * This case can occur if a local socket error occurred
8441 * between us sending out CHANNEL_OPEN and receiving
8442 * OPEN_FAILURE. In this case, we need do nothing except allow
8443 * the code below to throw the half-open channel away.
8447 * We never expect to receive OPEN_FAILURE for any *other*
8448 * channel type (since only local-to-remote port forwardings
8449 * cause us to send CHANNEL_OPEN after the main channel is
8450 * live - all other auxiliary channel types are initiated from
8451 * the server end). It's safe to enforce this by assertion
8452 * rather than by ssh_disconnect, because the real point is
8453 * that we never constructed a half-open channel structure in
8454 * the first place with any type other than the above.
8456 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8459 del234(ssh->channels, c);
8463 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8466 int typelen, want_reply;
8467 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8468 struct ssh_channel *c;
8469 struct Packet *pktout;
8471 c = ssh_channel_msg(ssh, pktin);
8474 ssh_pkt_getstring(pktin, &type, &typelen);
8475 want_reply = ssh2_pkt_getbool(pktin);
8477 if (c->closes & CLOSES_SENT_CLOSE) {
8479 * We don't reply to channel requests after we've sent
8480 * CHANNEL_CLOSE for the channel, because our reply might
8481 * cross in the network with the other side's CHANNEL_CLOSE
8482 * and arrive after they have wound the channel up completely.
8488 * Having got the channel number, we now look at
8489 * the request type string to see if it's something
8492 if (c == ssh->mainchan) {
8494 * We recognise "exit-status" and "exit-signal" on
8495 * the primary channel.
8497 if (typelen == 11 &&
8498 !memcmp(type, "exit-status", 11)) {
8500 ssh->exitcode = ssh_pkt_getuint32(pktin);
8501 logeventf(ssh, "Server sent command exit status %d",
8503 reply = SSH2_MSG_CHANNEL_SUCCESS;
8505 } else if (typelen == 11 &&
8506 !memcmp(type, "exit-signal", 11)) {
8508 int is_plausible = TRUE, is_int = FALSE;
8509 char *fmt_sig = NULL, *fmt_msg = NULL;
8511 int msglen = 0, core = FALSE;
8512 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8513 * provide an `int' for the signal, despite its
8514 * having been a `string' in the drafts of RFC 4254 since at
8515 * least 2001. (Fixed in session.c 1.147.) Try to
8516 * infer which we can safely parse it as. */
8518 unsigned char *p = pktin->body +
8520 long len = pktin->length - pktin->savedpos;
8521 unsigned long num = GET_32BIT(p); /* what is it? */
8522 /* If it's 0, it hardly matters; assume string */
8526 int maybe_int = FALSE, maybe_str = FALSE;
8527 #define CHECK_HYPOTHESIS(offset, result) \
8530 int q = toint(offset); \
8531 if (q >= 0 && q+4 <= len) { \
8532 q = toint(q + 4 + GET_32BIT(p+q)); \
8533 if (q >= 0 && q+4 <= len && \
8534 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8539 CHECK_HYPOTHESIS(4+1, maybe_int);
8540 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8541 #undef CHECK_HYPOTHESIS
8542 if (maybe_int && !maybe_str)
8544 else if (!maybe_int && maybe_str)
8547 /* Crikey. Either or neither. Panic. */
8548 is_plausible = FALSE;
8551 ssh->exitcode = 128; /* means `unknown signal' */
8554 /* Old non-standard OpenSSH. */
8555 int signum = ssh_pkt_getuint32(pktin);
8556 fmt_sig = dupprintf(" %d", signum);
8557 ssh->exitcode = 128 + signum;
8559 /* As per RFC 4254. */
8562 ssh_pkt_getstring(pktin, &sig, &siglen);
8563 /* Signal name isn't supposed to be blank, but
8564 * let's cope gracefully if it is. */
8566 fmt_sig = dupprintf(" \"%.*s\"",
8571 * Really hideous method of translating the
8572 * signal description back into a locally
8573 * meaningful number.
8578 #define TRANSLATE_SIGNAL(s) \
8579 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8580 ssh->exitcode = 128 + SIG ## s
8582 TRANSLATE_SIGNAL(ABRT);
8585 TRANSLATE_SIGNAL(ALRM);
8588 TRANSLATE_SIGNAL(FPE);
8591 TRANSLATE_SIGNAL(HUP);
8594 TRANSLATE_SIGNAL(ILL);
8597 TRANSLATE_SIGNAL(INT);
8600 TRANSLATE_SIGNAL(KILL);
8603 TRANSLATE_SIGNAL(PIPE);
8606 TRANSLATE_SIGNAL(QUIT);
8609 TRANSLATE_SIGNAL(SEGV);
8612 TRANSLATE_SIGNAL(TERM);
8615 TRANSLATE_SIGNAL(USR1);
8618 TRANSLATE_SIGNAL(USR2);
8620 #undef TRANSLATE_SIGNAL
8622 ssh->exitcode = 128;
8624 core = ssh2_pkt_getbool(pktin);
8625 ssh_pkt_getstring(pktin, &msg, &msglen);
8627 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8629 /* ignore lang tag */
8630 } /* else don't attempt to parse */
8631 logeventf(ssh, "Server exited on signal%s%s%s",
8632 fmt_sig ? fmt_sig : "",
8633 core ? " (core dumped)" : "",
8634 fmt_msg ? fmt_msg : "");
8637 reply = SSH2_MSG_CHANNEL_SUCCESS;
8642 * This is a channel request we don't know
8643 * about, so we now either ignore the request
8644 * or respond with CHANNEL_FAILURE, depending
8647 reply = SSH2_MSG_CHANNEL_FAILURE;
8650 pktout = ssh2_pkt_init(reply);
8651 ssh2_pkt_adduint32(pktout, c->remoteid);
8652 ssh2_pkt_send(ssh, pktout);
8656 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8659 int typelen, want_reply;
8660 struct Packet *pktout;
8662 ssh_pkt_getstring(pktin, &type, &typelen);
8663 want_reply = ssh2_pkt_getbool(pktin);
8666 * We currently don't support any global requests
8667 * at all, so we either ignore the request or
8668 * respond with REQUEST_FAILURE, depending on
8672 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8673 ssh2_pkt_send(ssh, pktout);
8677 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8681 struct X11FakeAuth *auth;
8684 * Make up a new set of fake X11 auth data, and add it to the tree
8685 * of currently valid ones with an indication of the sharing
8686 * context that it's relevant to.
8688 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8689 auth->share_cs = share_cs;
8690 auth->share_chan = share_chan;
8695 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8697 del234(ssh->x11authtree, auth);
8698 x11_free_fake_auth(auth);
8701 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8708 const char *error = NULL;
8709 struct ssh_channel *c;
8710 unsigned remid, winsize, pktsize;
8711 unsigned our_winsize_override = 0;
8712 struct Packet *pktout;
8714 ssh_pkt_getstring(pktin, &type, &typelen);
8715 c = snew(struct ssh_channel);
8718 remid = ssh_pkt_getuint32(pktin);
8719 winsize = ssh_pkt_getuint32(pktin);
8720 pktsize = ssh_pkt_getuint32(pktin);
8722 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8725 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8726 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8727 peerport = ssh_pkt_getuint32(pktin);
8729 logeventf(ssh, "Received X11 connect request from %s:%d",
8732 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8733 error = "X11 forwarding is not enabled";
8735 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8738 c->u.x11.initial = TRUE;
8741 * If we are a connection-sharing upstream, then we should
8742 * initially present a very small window, adequate to take
8743 * the X11 initial authorisation packet but not much more.
8744 * Downstream will then present us a larger window (by
8745 * fiat of the connection-sharing protocol) and we can
8746 * guarantee to send a positive-valued WINDOW_ADJUST.
8749 our_winsize_override = 128;
8751 logevent("Opened X11 forward channel");
8755 } else if (typelen == 15 &&
8756 !memcmp(type, "forwarded-tcpip", 15)) {
8757 struct ssh_rportfwd pf, *realpf;
8760 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8761 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8762 pf.sport = ssh_pkt_getuint32(pktin);
8763 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8764 peerport = ssh_pkt_getuint32(pktin);
8765 realpf = find234(ssh->rportfwds, &pf, NULL);
8766 logeventf(ssh, "Received remote port %s:%d open request "
8767 "from %.*s:%d", pf.shost, pf.sport,
8768 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8771 if (realpf == NULL) {
8772 error = "Remote port is not recognised";
8776 if (realpf->share_ctx) {
8778 * This port forwarding is on behalf of a
8779 * connection-sharing downstream, so abandon our own
8780 * channel-open procedure and just pass the message on
8783 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8784 pktin->body, pktin->length);
8789 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8790 c, ssh->conf, realpf->pfrec->addressfamily);
8791 logeventf(ssh, "Attempting to forward remote port to "
8792 "%s:%d", realpf->dhost, realpf->dport);
8794 logeventf(ssh, "Port open failed: %s", err);
8796 error = "Port open failed";
8798 logevent("Forwarded port opened successfully");
8799 c->type = CHAN_SOCKDATA;
8802 } else if (typelen == 22 &&
8803 !memcmp(type, "auth-agent@openssh.com", 22)) {
8804 if (!ssh->agentfwd_enabled)
8805 error = "Agent forwarding is not enabled";
8807 c->type = CHAN_AGENT; /* identify channel type */
8808 c->u.a.lensofar = 0;
8809 c->u.a.message = NULL;
8810 c->u.a.outstanding_requests = 0;
8813 error = "Unsupported channel type requested";
8816 c->remoteid = remid;
8817 c->halfopen = FALSE;
8819 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8820 ssh2_pkt_adduint32(pktout, c->remoteid);
8821 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8822 ssh2_pkt_addstring(pktout, error);
8823 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8824 ssh2_pkt_send(ssh, pktout);
8825 logeventf(ssh, "Rejected channel open: %s", error);
8828 ssh_channel_init(c);
8829 c->v.v2.remwindow = winsize;
8830 c->v.v2.remmaxpkt = pktsize;
8831 if (our_winsize_override) {
8832 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8833 our_winsize_override;
8835 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8836 ssh2_pkt_adduint32(pktout, c->remoteid);
8837 ssh2_pkt_adduint32(pktout, c->localid);
8838 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8839 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8840 ssh2_pkt_send(ssh, pktout);
8844 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8845 void *share_cs, void *share_chan,
8846 const char *peer_addr, int peer_port,
8847 int endian, int protomajor, int protominor,
8848 const void *initial_data, int initial_len)
8851 * This function is called when we've just discovered that an X
8852 * forwarding channel on which we'd been handling the initial auth
8853 * ourselves turns out to be destined for a connection-sharing
8854 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8855 * that we completely stop tracking windows and buffering data and
8856 * just pass more or less unmodified SSH messages back and forth.
8858 c->type = CHAN_SHARING;
8859 c->u.sharing.ctx = share_cs;
8860 share_setup_x11_channel(share_cs, share_chan,
8861 c->localid, c->remoteid, c->v.v2.remwindow,
8862 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8863 peer_addr, peer_port, endian,
8864 protomajor, protominor,
8865 initial_data, initial_len);
8868 void sshfwd_x11_is_local(struct ssh_channel *c)
8871 * This function is called when we've just discovered that an X
8872 * forwarding channel is _not_ destined for a connection-sharing
8873 * downstream but we're going to handle it ourselves. We stop
8874 * presenting a cautiously small window and go into ordinary data
8877 c->u.x11.initial = FALSE;
8878 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8882 * Buffer banner messages for later display at some convenient point,
8883 * if we're going to display them.
8885 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8887 /* Arbitrary limit to prevent unbounded inflation of buffer */
8888 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8889 bufchain_size(&ssh->banner) <= 131072) {
8890 char *banner = NULL;
8892 ssh_pkt_getstring(pktin, &banner, &size);
8894 bufchain_add(&ssh->banner, banner, size);
8898 /* Helper function to deal with sending tty modes for "pty-req" */
8899 static void ssh2_send_ttymode(void *data,
8900 const struct ssh_ttymode *mode, char *val)
8902 struct Packet *pktout = (struct Packet *)data;
8903 unsigned int arg = 0;
8905 switch (mode->type) {
8907 arg = ssh_tty_parse_specchar(val);
8910 arg = ssh_tty_parse_boolean(val);
8913 ssh2_pkt_addbyte(pktout, mode->opcode);
8914 ssh2_pkt_adduint32(pktout, arg);
8917 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8920 struct ssh2_setup_x11_state {
8924 struct Packet *pktout;
8925 crStateP(ssh2_setup_x11_state, ctx);
8929 logevent("Requesting X11 forwarding");
8930 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8932 ssh2_pkt_addbool(pktout, 0); /* many connections */
8933 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8934 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8935 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8936 ssh2_pkt_send(ssh, pktout);
8938 /* Wait to be called back with either a response packet, or NULL
8939 * meaning clean up and free our data */
8943 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8944 logevent("X11 forwarding enabled");
8945 ssh->X11_fwd_enabled = TRUE;
8947 logevent("X11 forwarding refused");
8953 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8956 struct ssh2_setup_agent_state {
8960 struct Packet *pktout;
8961 crStateP(ssh2_setup_agent_state, ctx);
8965 logevent("Requesting OpenSSH-style agent forwarding");
8966 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8967 ssh2_setup_agent, s);
8968 ssh2_pkt_send(ssh, pktout);
8970 /* Wait to be called back with either a response packet, or NULL
8971 * meaning clean up and free our data */
8975 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8976 logevent("Agent forwarding enabled");
8977 ssh->agentfwd_enabled = TRUE;
8979 logevent("Agent forwarding refused");
8985 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8988 struct ssh2_setup_pty_state {
8992 struct Packet *pktout;
8993 crStateP(ssh2_setup_pty_state, ctx);
8997 /* Unpick the terminal-speed string. */
8998 /* XXX perhaps we should allow no speeds to be sent. */
8999 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9000 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9001 /* Build the pty request. */
9002 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9004 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9005 ssh2_pkt_adduint32(pktout, ssh->term_width);
9006 ssh2_pkt_adduint32(pktout, ssh->term_height);
9007 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9008 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9009 ssh2_pkt_addstring_start(pktout);
9010 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9011 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9012 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9013 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9014 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9015 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9016 ssh2_pkt_send(ssh, pktout);
9017 ssh->state = SSH_STATE_INTERMED;
9019 /* Wait to be called back with either a response packet, or NULL
9020 * meaning clean up and free our data */
9024 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9025 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9026 ssh->ospeed, ssh->ispeed);
9027 ssh->got_pty = TRUE;
9029 c_write_str(ssh, "Server refused to allocate pty\r\n");
9030 ssh->editing = ssh->echoing = 1;
9037 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9040 struct ssh2_setup_env_state {
9042 int num_env, env_left, env_ok;
9045 struct Packet *pktout;
9046 crStateP(ssh2_setup_env_state, ctx);
9051 * Send environment variables.
9053 * Simplest thing here is to send all the requests at once, and
9054 * then wait for a whole bunch of successes or failures.
9060 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9062 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9063 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9064 ssh2_pkt_addstring(pktout, key);
9065 ssh2_pkt_addstring(pktout, val);
9066 ssh2_pkt_send(ssh, pktout);
9071 logeventf(ssh, "Sent %d environment variables", s->num_env);
9076 s->env_left = s->num_env;
9078 while (s->env_left > 0) {
9079 /* Wait to be called back with either a response packet,
9080 * or NULL meaning clean up and free our data */
9082 if (!pktin) goto out;
9083 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9088 if (s->env_ok == s->num_env) {
9089 logevent("All environment variables successfully set");
9090 } else if (s->env_ok == 0) {
9091 logevent("All environment variables refused");
9092 c_write_str(ssh, "Server refused to set environment variables\r\n");
9094 logeventf(ssh, "%d environment variables refused",
9095 s->num_env - s->env_ok);
9096 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9104 * Handle the SSH-2 userauth and connection layers.
9106 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9108 do_ssh2_authconn(ssh, NULL, 0, pktin);
9111 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9115 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9118 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9119 struct Packet *pktin)
9121 struct do_ssh2_authconn_state {
9125 AUTH_TYPE_PUBLICKEY,
9126 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9127 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9129 AUTH_TYPE_GSSAPI, /* always QUIET */
9130 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9131 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9133 int done_service_req;
9134 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9135 int tried_pubkey_config, done_agent;
9140 int kbd_inter_refused;
9141 int we_are_in, userauth_success;
9142 prompts_t *cur_prompt;
9147 void *publickey_blob;
9148 int publickey_bloblen;
9149 int privatekey_available, privatekey_encrypted;
9150 char *publickey_algorithm;
9151 char *publickey_comment;
9152 unsigned char agent_request[5], *agent_response, *agentp;
9153 int agent_responselen;
9154 unsigned char *pkblob_in_agent;
9156 char *pkblob, *alg, *commentp;
9157 int pklen, alglen, commentlen;
9158 int siglen, retlen, len;
9159 char *q, *agentreq, *ret;
9160 struct Packet *pktout;
9163 struct ssh_gss_library *gsslib;
9164 Ssh_gss_ctx gss_ctx;
9165 Ssh_gss_buf gss_buf;
9166 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9167 Ssh_gss_name gss_srv_name;
9168 Ssh_gss_stat gss_stat;
9171 crState(do_ssh2_authconn_state);
9175 /* Register as a handler for all the messages this coroutine handles. */
9176 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9177 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9178 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9179 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9180 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9181 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9182 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9183 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9184 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9185 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9186 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9187 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9188 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9189 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9190 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9191 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9192 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9193 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9194 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9195 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9197 s->done_service_req = FALSE;
9198 s->we_are_in = s->userauth_success = FALSE;
9199 s->agent_response = NULL;
9201 s->tried_gssapi = FALSE;
9204 if (!ssh->bare_connection) {
9205 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9207 * Request userauth protocol, and await a response to it.
9209 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9210 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9211 ssh2_pkt_send(ssh, s->pktout);
9212 crWaitUntilV(pktin);
9213 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9214 s->done_service_req = TRUE;
9216 if (!s->done_service_req) {
9218 * Request connection protocol directly, without authentication.
9220 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9221 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9222 ssh2_pkt_send(ssh, s->pktout);
9223 crWaitUntilV(pktin);
9224 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9225 s->we_are_in = TRUE; /* no auth required */
9227 bombout(("Server refused service request"));
9232 s->we_are_in = TRUE;
9235 /* Arrange to be able to deal with any BANNERs that come in.
9236 * (We do this now as packets may come in during the next bit.) */
9237 bufchain_init(&ssh->banner);
9238 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9239 ssh2_msg_userauth_banner;
9242 * Misc one-time setup for authentication.
9244 s->publickey_blob = NULL;
9245 if (!s->we_are_in) {
9248 * Load the public half of any configured public key file
9251 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9252 if (!filename_is_null(s->keyfile)) {
9254 logeventf(ssh, "Reading key file \"%.150s\"",
9255 filename_to_str(s->keyfile));
9256 keytype = key_type(s->keyfile);
9257 if (keytype == SSH_KEYTYPE_SSH2 ||
9258 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9259 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9262 ssh2_userkey_loadpub(s->keyfile,
9263 &s->publickey_algorithm,
9264 &s->publickey_bloblen,
9265 &s->publickey_comment, &error);
9266 if (s->publickey_blob) {
9267 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9268 if (!s->privatekey_available)
9269 logeventf(ssh, "Key file contains public key only");
9270 s->privatekey_encrypted =
9271 ssh2_userkey_encrypted(s->keyfile, NULL);
9274 logeventf(ssh, "Unable to load key (%s)",
9276 msgbuf = dupprintf("Unable to load key file "
9277 "\"%.150s\" (%s)\r\n",
9278 filename_to_str(s->keyfile),
9280 c_write_str(ssh, msgbuf);
9285 logeventf(ssh, "Unable to use this key file (%s)",
9286 key_type_to_str(keytype));
9287 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9289 filename_to_str(s->keyfile),
9290 key_type_to_str(keytype));
9291 c_write_str(ssh, msgbuf);
9293 s->publickey_blob = NULL;
9298 * Find out about any keys Pageant has (but if there's a
9299 * public key configured, filter out all others).
9302 s->agent_response = NULL;
9303 s->pkblob_in_agent = NULL;
9304 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9308 logevent("Pageant is running. Requesting keys.");
9310 /* Request the keys held by the agent. */
9311 PUT_32BIT(s->agent_request, 1);
9312 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9313 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9314 ssh_agent_callback, ssh)) {
9318 bombout(("Unexpected data from server while"
9319 " waiting for agent response"));
9322 } while (pktin || inlen > 0);
9323 r = ssh->agent_response;
9324 s->agent_responselen = ssh->agent_response_len;
9326 s->agent_response = (unsigned char *) r;
9327 if (s->agent_response && s->agent_responselen >= 5 &&
9328 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9331 p = s->agent_response + 5;
9332 s->nkeys = toint(GET_32BIT(p));
9335 * Vet the Pageant response to ensure that the key
9336 * count and blob lengths make sense.
9339 logeventf(ssh, "Pageant response contained a negative"
9340 " key count %d", s->nkeys);
9342 goto done_agent_query;
9344 unsigned char *q = p + 4;
9345 int lenleft = s->agent_responselen - 5 - 4;
9347 for (keyi = 0; keyi < s->nkeys; keyi++) {
9348 int bloblen, commentlen;
9350 logeventf(ssh, "Pageant response was truncated");
9352 goto done_agent_query;
9354 bloblen = toint(GET_32BIT(q));
9355 if (bloblen < 0 || bloblen > lenleft) {
9356 logeventf(ssh, "Pageant response was truncated");
9358 goto done_agent_query;
9360 lenleft -= 4 + bloblen;
9362 commentlen = toint(GET_32BIT(q));
9363 if (commentlen < 0 || commentlen > lenleft) {
9364 logeventf(ssh, "Pageant response was truncated");
9366 goto done_agent_query;
9368 lenleft -= 4 + commentlen;
9369 q += 4 + commentlen;
9374 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9375 if (s->publickey_blob) {
9376 /* See if configured key is in agent. */
9377 for (keyi = 0; keyi < s->nkeys; keyi++) {
9378 s->pklen = toint(GET_32BIT(p));
9379 if (s->pklen == s->publickey_bloblen &&
9380 !memcmp(p+4, s->publickey_blob,
9381 s->publickey_bloblen)) {
9382 logeventf(ssh, "Pageant key #%d matches "
9383 "configured key file", keyi);
9385 s->pkblob_in_agent = p;
9389 p += toint(GET_32BIT(p)) + 4; /* comment */
9391 if (!s->pkblob_in_agent) {
9392 logevent("Configured key file not in Pageant");
9397 logevent("Failed to get reply from Pageant");
9405 * We repeat this whole loop, including the username prompt,
9406 * until we manage a successful authentication. If the user
9407 * types the wrong _password_, they can be sent back to the
9408 * beginning to try another username, if this is configured on.
9409 * (If they specify a username in the config, they are never
9410 * asked, even if they do give a wrong password.)
9412 * I think this best serves the needs of
9414 * - the people who have no configuration, no keys, and just
9415 * want to try repeated (username,password) pairs until they
9416 * type both correctly
9418 * - people who have keys and configuration but occasionally
9419 * need to fall back to passwords
9421 * - people with a key held in Pageant, who might not have
9422 * logged in to a particular machine before; so they want to
9423 * type a username, and then _either_ their key will be
9424 * accepted, _or_ they will type a password. If they mistype
9425 * the username they will want to be able to get back and
9428 s->got_username = FALSE;
9429 while (!s->we_are_in) {
9433 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9435 * We got a username last time round this loop, and
9436 * with change_username turned off we don't try to get
9439 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9440 int ret; /* need not be kept over crReturn */
9441 s->cur_prompt = new_prompts(ssh->frontend);
9442 s->cur_prompt->to_server = TRUE;
9443 s->cur_prompt->name = dupstr("SSH login name");
9444 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9445 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9448 crWaitUntilV(!pktin);
9449 ret = get_userpass_input(s->cur_prompt, in, inlen);
9454 * get_userpass_input() failed to get a username.
9457 free_prompts(s->cur_prompt);
9458 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9461 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9462 free_prompts(s->cur_prompt);
9465 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9466 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9467 c_write_str(ssh, stuff);
9471 s->got_username = TRUE;
9474 * Send an authentication request using method "none": (a)
9475 * just in case it succeeds, and (b) so that we know what
9476 * authentication methods we can usefully try next.
9478 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9480 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9481 ssh2_pkt_addstring(s->pktout, ssh->username);
9482 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9483 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9484 ssh2_pkt_send(ssh, s->pktout);
9485 s->type = AUTH_TYPE_NONE;
9487 s->we_are_in = FALSE;
9489 s->tried_pubkey_config = FALSE;
9490 s->kbd_inter_refused = FALSE;
9492 /* Reset agent request state. */
9493 s->done_agent = FALSE;
9494 if (s->agent_response) {
9495 if (s->pkblob_in_agent) {
9496 s->agentp = s->pkblob_in_agent;
9498 s->agentp = s->agent_response + 5 + 4;
9504 char *methods = NULL;
9508 * Wait for the result of the last authentication request.
9511 crWaitUntilV(pktin);
9513 * Now is a convenient point to spew any banner material
9514 * that we've accumulated. (This should ensure that when
9515 * we exit the auth loop, we haven't any left to deal
9519 int size = bufchain_size(&ssh->banner);
9521 * Don't show the banner if we're operating in
9522 * non-verbose non-interactive mode. (It's probably
9523 * a script, which means nobody will read the
9524 * banner _anyway_, and moreover the printing of
9525 * the banner will screw up processing on the
9526 * output of (say) plink.)
9528 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9529 char *banner = snewn(size, char);
9530 bufchain_fetch(&ssh->banner, banner, size);
9531 c_write_untrusted(ssh, banner, size);
9534 bufchain_clear(&ssh->banner);
9536 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9537 logevent("Access granted");
9538 s->we_are_in = s->userauth_success = TRUE;
9542 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9543 bombout(("Strange packet received during authentication: "
9544 "type %d", pktin->type));
9551 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9552 * we can look at the string in it and know what we can
9553 * helpfully try next.
9555 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9556 ssh_pkt_getstring(pktin, &methods, &methlen);
9557 if (!ssh2_pkt_getbool(pktin)) {
9559 * We have received an unequivocal Access
9560 * Denied. This can translate to a variety of
9561 * messages, or no message at all.
9563 * For forms of authentication which are attempted
9564 * implicitly, by which I mean without printing
9565 * anything in the window indicating that we're
9566 * trying them, we should never print 'Access
9569 * If we do print a message saying that we're
9570 * attempting some kind of authentication, it's OK
9571 * to print a followup message saying it failed -
9572 * but the message may sometimes be more specific
9573 * than simply 'Access denied'.
9575 * Additionally, if we'd just tried password
9576 * authentication, we should break out of this
9577 * whole loop so as to go back to the username
9578 * prompt (iff we're configured to allow
9579 * username change attempts).
9581 if (s->type == AUTH_TYPE_NONE) {
9583 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9584 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9585 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9586 c_write_str(ssh, "Server refused our key\r\n");
9587 logevent("Server refused our key");
9588 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9589 /* This _shouldn't_ happen except by a
9590 * protocol bug causing client and server to
9591 * disagree on what is a correct signature. */
9592 c_write_str(ssh, "Server refused public-key signature"
9593 " despite accepting key!\r\n");
9594 logevent("Server refused public-key signature"
9595 " despite accepting key!");
9596 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9597 /* quiet, so no c_write */
9598 logevent("Server refused keyboard-interactive authentication");
9599 } else if (s->type==AUTH_TYPE_GSSAPI) {
9600 /* always quiet, so no c_write */
9601 /* also, the code down in the GSSAPI block has
9602 * already logged this in the Event Log */
9603 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9604 logevent("Keyboard-interactive authentication failed");
9605 c_write_str(ssh, "Access denied\r\n");
9607 assert(s->type == AUTH_TYPE_PASSWORD);
9608 logevent("Password authentication failed");
9609 c_write_str(ssh, "Access denied\r\n");
9611 if (conf_get_int(ssh->conf, CONF_change_username)) {
9612 /* XXX perhaps we should allow
9613 * keyboard-interactive to do this too? */
9614 s->we_are_in = FALSE;
9619 c_write_str(ssh, "Further authentication required\r\n");
9620 logevent("Further authentication required");
9624 in_commasep_string("publickey", methods, methlen);
9626 in_commasep_string("password", methods, methlen);
9627 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9628 in_commasep_string("keyboard-interactive", methods, methlen);
9630 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9631 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9632 /* Try loading the GSS libraries and see if we
9635 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9636 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9638 /* No point in even bothering to try to load the
9639 * GSS libraries, if the user configuration and
9640 * server aren't both prepared to attempt GSSAPI
9641 * auth in the first place. */
9642 s->can_gssapi = FALSE;
9647 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9649 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9652 * Attempt public-key authentication using a key from Pageant.
9655 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9657 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9659 /* Unpack key from agent response */
9660 s->pklen = toint(GET_32BIT(s->agentp));
9662 s->pkblob = (char *)s->agentp;
9663 s->agentp += s->pklen;
9664 s->alglen = toint(GET_32BIT(s->pkblob));
9665 s->alg = s->pkblob + 4;
9666 s->commentlen = toint(GET_32BIT(s->agentp));
9668 s->commentp = (char *)s->agentp;
9669 s->agentp += s->commentlen;
9670 /* s->agentp now points at next key, if any */
9672 /* See if server will accept it */
9673 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9674 ssh2_pkt_addstring(s->pktout, ssh->username);
9675 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9676 /* service requested */
9677 ssh2_pkt_addstring(s->pktout, "publickey");
9679 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9680 ssh2_pkt_addstring_start(s->pktout);
9681 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9682 ssh2_pkt_addstring_start(s->pktout);
9683 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9684 ssh2_pkt_send(ssh, s->pktout);
9685 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9687 crWaitUntilV(pktin);
9688 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9690 /* Offer of key refused. */
9697 if (flags & FLAG_VERBOSE) {
9698 c_write_str(ssh, "Authenticating with "
9700 c_write(ssh, s->commentp, s->commentlen);
9701 c_write_str(ssh, "\" from agent\r\n");
9705 * Server is willing to accept the key.
9706 * Construct a SIGN_REQUEST.
9708 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9709 ssh2_pkt_addstring(s->pktout, ssh->username);
9710 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9711 /* service requested */
9712 ssh2_pkt_addstring(s->pktout, "publickey");
9714 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9715 ssh2_pkt_addstring_start(s->pktout);
9716 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9717 ssh2_pkt_addstring_start(s->pktout);
9718 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9720 /* Ask agent for signature. */
9721 s->siglen = s->pktout->length - 5 + 4 +
9722 ssh->v2_session_id_len;
9723 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9725 s->len = 1; /* message type */
9726 s->len += 4 + s->pklen; /* key blob */
9727 s->len += 4 + s->siglen; /* data to sign */
9728 s->len += 4; /* flags */
9729 s->agentreq = snewn(4 + s->len, char);
9730 PUT_32BIT(s->agentreq, s->len);
9731 s->q = s->agentreq + 4;
9732 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9733 PUT_32BIT(s->q, s->pklen);
9735 memcpy(s->q, s->pkblob, s->pklen);
9737 PUT_32BIT(s->q, s->siglen);
9739 /* Now the data to be signed... */
9740 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9741 PUT_32BIT(s->q, ssh->v2_session_id_len);
9744 memcpy(s->q, ssh->v2_session_id,
9745 ssh->v2_session_id_len);
9746 s->q += ssh->v2_session_id_len;
9747 memcpy(s->q, s->pktout->data + 5,
9748 s->pktout->length - 5);
9749 s->q += s->pktout->length - 5;
9750 /* And finally the (zero) flags word. */
9752 if (!agent_query(s->agentreq, s->len + 4,
9754 ssh_agent_callback, ssh)) {
9758 bombout(("Unexpected data from server"
9759 " while waiting for agent"
9763 } while (pktin || inlen > 0);
9764 vret = ssh->agent_response;
9765 s->retlen = ssh->agent_response_len;
9770 if (s->retlen >= 9 &&
9771 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9772 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9773 logevent("Sending Pageant's response");
9774 ssh2_add_sigblob(ssh, s->pktout,
9775 s->pkblob, s->pklen,
9777 GET_32BIT(s->ret + 5));
9778 ssh2_pkt_send(ssh, s->pktout);
9779 s->type = AUTH_TYPE_PUBLICKEY;
9781 /* FIXME: less drastic response */
9782 bombout(("Pageant failed to answer challenge"));
9788 /* Do we have any keys left to try? */
9789 if (s->pkblob_in_agent) {
9790 s->done_agent = TRUE;
9791 s->tried_pubkey_config = TRUE;
9794 if (s->keyi >= s->nkeys)
9795 s->done_agent = TRUE;
9798 } else if (s->can_pubkey && s->publickey_blob &&
9799 s->privatekey_available && !s->tried_pubkey_config) {
9801 struct ssh2_userkey *key; /* not live over crReturn */
9802 char *passphrase; /* not live over crReturn */
9804 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9806 s->tried_pubkey_config = TRUE;
9809 * Try the public key supplied in the configuration.
9811 * First, offer the public blob to see if the server is
9812 * willing to accept it.
9814 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9815 ssh2_pkt_addstring(s->pktout, ssh->username);
9816 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9817 /* service requested */
9818 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9819 ssh2_pkt_addbool(s->pktout, FALSE);
9820 /* no signature included */
9821 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9822 ssh2_pkt_addstring_start(s->pktout);
9823 ssh2_pkt_addstring_data(s->pktout,
9824 (char *)s->publickey_blob,
9825 s->publickey_bloblen);
9826 ssh2_pkt_send(ssh, s->pktout);
9827 logevent("Offered public key");
9829 crWaitUntilV(pktin);
9830 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9831 /* Key refused. Give up. */
9832 s->gotit = TRUE; /* reconsider message next loop */
9833 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9834 continue; /* process this new message */
9836 logevent("Offer of public key accepted");
9839 * Actually attempt a serious authentication using
9842 if (flags & FLAG_VERBOSE) {
9843 c_write_str(ssh, "Authenticating with public key \"");
9844 c_write_str(ssh, s->publickey_comment);
9845 c_write_str(ssh, "\"\r\n");
9849 const char *error; /* not live over crReturn */
9850 if (s->privatekey_encrypted) {
9852 * Get a passphrase from the user.
9854 int ret; /* need not be kept over crReturn */
9855 s->cur_prompt = new_prompts(ssh->frontend);
9856 s->cur_prompt->to_server = FALSE;
9857 s->cur_prompt->name = dupstr("SSH key passphrase");
9858 add_prompt(s->cur_prompt,
9859 dupprintf("Passphrase for key \"%.100s\": ",
9860 s->publickey_comment),
9862 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9865 crWaitUntilV(!pktin);
9866 ret = get_userpass_input(s->cur_prompt,
9871 /* Failed to get a passphrase. Terminate. */
9872 free_prompts(s->cur_prompt);
9873 ssh_disconnect(ssh, NULL,
9874 "Unable to authenticate",
9875 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9880 dupstr(s->cur_prompt->prompts[0]->result);
9881 free_prompts(s->cur_prompt);
9883 passphrase = NULL; /* no passphrase needed */
9887 * Try decrypting the key.
9889 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9890 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9892 /* burn the evidence */
9893 smemclr(passphrase, strlen(passphrase));
9896 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9898 (key == SSH2_WRONG_PASSPHRASE)) {
9899 c_write_str(ssh, "Wrong passphrase\r\n");
9901 /* and loop again */
9903 c_write_str(ssh, "Unable to load private key (");
9904 c_write_str(ssh, error);
9905 c_write_str(ssh, ")\r\n");
9907 break; /* try something else */
9913 unsigned char *pkblob, *sigblob, *sigdata;
9914 int pkblob_len, sigblob_len, sigdata_len;
9918 * We have loaded the private key and the server
9919 * has announced that it's willing to accept it.
9920 * Hallelujah. Generate a signature and send it.
9922 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9923 ssh2_pkt_addstring(s->pktout, ssh->username);
9924 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9925 /* service requested */
9926 ssh2_pkt_addstring(s->pktout, "publickey");
9928 ssh2_pkt_addbool(s->pktout, TRUE);
9929 /* signature follows */
9930 ssh2_pkt_addstring(s->pktout, key->alg->name);
9931 pkblob = key->alg->public_blob(key->data,
9933 ssh2_pkt_addstring_start(s->pktout);
9934 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9938 * The data to be signed is:
9942 * followed by everything so far placed in the
9945 sigdata_len = s->pktout->length - 5 + 4 +
9946 ssh->v2_session_id_len;
9947 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9949 sigdata = snewn(sigdata_len, unsigned char);
9951 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9952 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9955 memcpy(sigdata+p, ssh->v2_session_id,
9956 ssh->v2_session_id_len);
9957 p += ssh->v2_session_id_len;
9958 memcpy(sigdata+p, s->pktout->data + 5,
9959 s->pktout->length - 5);
9960 p += s->pktout->length - 5;
9961 assert(p == sigdata_len);
9962 sigblob = key->alg->sign(key->data, (char *)sigdata,
9963 sigdata_len, &sigblob_len);
9964 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9965 sigblob, sigblob_len);
9970 ssh2_pkt_send(ssh, s->pktout);
9971 logevent("Sent public key signature");
9972 s->type = AUTH_TYPE_PUBLICKEY;
9973 key->alg->freekey(key->data);
9974 sfree(key->comment);
9979 } else if (s->can_gssapi && !s->tried_gssapi) {
9981 /* GSSAPI Authentication */
9986 s->type = AUTH_TYPE_GSSAPI;
9987 s->tried_gssapi = TRUE;
9989 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9992 * Pick the highest GSS library on the preference
9998 for (i = 0; i < ngsslibs; i++) {
9999 int want_id = conf_get_int_int(ssh->conf,
10000 CONF_ssh_gsslist, i);
10001 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10002 if (ssh->gsslibs->libraries[j].id == want_id) {
10003 s->gsslib = &ssh->gsslibs->libraries[j];
10004 goto got_gsslib; /* double break */
10009 * We always expect to have found something in
10010 * the above loop: we only came here if there
10011 * was at least one viable GSS library, and the
10012 * preference list should always mention
10013 * everything and only change the order.
10018 if (s->gsslib->gsslogmsg)
10019 logevent(s->gsslib->gsslogmsg);
10021 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10022 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10023 ssh2_pkt_addstring(s->pktout, ssh->username);
10024 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10025 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10026 logevent("Attempting GSSAPI authentication");
10028 /* add mechanism info */
10029 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10031 /* number of GSSAPI mechanisms */
10032 ssh2_pkt_adduint32(s->pktout,1);
10034 /* length of OID + 2 */
10035 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10036 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10038 /* length of OID */
10039 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10041 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10042 s->gss_buf.length);
10043 ssh2_pkt_send(ssh, s->pktout);
10044 crWaitUntilV(pktin);
10045 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10046 logevent("GSSAPI authentication request refused");
10050 /* check returned packet ... */
10052 ssh_pkt_getstring(pktin, &data, &len);
10053 s->gss_rcvtok.value = data;
10054 s->gss_rcvtok.length = len;
10055 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10056 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10057 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10058 memcmp((char *)s->gss_rcvtok.value + 2,
10059 s->gss_buf.value,s->gss_buf.length) ) {
10060 logevent("GSSAPI authentication - wrong response from server");
10064 /* now start running */
10065 s->gss_stat = s->gsslib->import_name(s->gsslib,
10068 if (s->gss_stat != SSH_GSS_OK) {
10069 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10070 logevent("GSSAPI import name failed - Bad service name");
10072 logevent("GSSAPI import name failed");
10076 /* fetch TGT into GSS engine */
10077 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10079 if (s->gss_stat != SSH_GSS_OK) {
10080 logevent("GSSAPI authentication failed to get credentials");
10081 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10085 /* initial tokens are empty */
10086 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10087 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10089 /* now enter the loop */
10091 s->gss_stat = s->gsslib->init_sec_context
10095 conf_get_int(ssh->conf, CONF_gssapifwd),
10099 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10100 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10101 logevent("GSSAPI authentication initialisation failed");
10103 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10104 &s->gss_buf) == SSH_GSS_OK) {
10105 logevent(s->gss_buf.value);
10106 sfree(s->gss_buf.value);
10111 logevent("GSSAPI authentication initialised");
10113 /* Client and server now exchange tokens until GSSAPI
10114 * no longer says CONTINUE_NEEDED */
10116 if (s->gss_sndtok.length != 0) {
10117 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10118 ssh_pkt_addstring_start(s->pktout);
10119 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10120 ssh2_pkt_send(ssh, s->pktout);
10121 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10124 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10125 crWaitUntilV(pktin);
10126 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10127 logevent("GSSAPI authentication - bad server response");
10128 s->gss_stat = SSH_GSS_FAILURE;
10131 ssh_pkt_getstring(pktin, &data, &len);
10132 s->gss_rcvtok.value = data;
10133 s->gss_rcvtok.length = len;
10135 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10137 if (s->gss_stat != SSH_GSS_OK) {
10138 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10139 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10142 logevent("GSSAPI authentication loop finished OK");
10144 /* Now send the MIC */
10146 s->pktout = ssh2_pkt_init(0);
10147 micoffset = s->pktout->length;
10148 ssh_pkt_addstring_start(s->pktout);
10149 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10150 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10151 ssh_pkt_addstring(s->pktout, ssh->username);
10152 ssh_pkt_addstring(s->pktout, "ssh-connection");
10153 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10155 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10156 s->gss_buf.length = s->pktout->length - micoffset;
10158 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10159 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10160 ssh_pkt_addstring_start(s->pktout);
10161 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10162 ssh2_pkt_send(ssh, s->pktout);
10163 s->gsslib->free_mic(s->gsslib, &mic);
10167 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10168 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10171 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10174 * Keyboard-interactive authentication.
10177 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10179 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10181 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10182 ssh2_pkt_addstring(s->pktout, ssh->username);
10183 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10184 /* service requested */
10185 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10187 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10188 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10189 ssh2_pkt_send(ssh, s->pktout);
10191 logevent("Attempting keyboard-interactive authentication");
10193 crWaitUntilV(pktin);
10194 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10195 /* Server is not willing to do keyboard-interactive
10196 * at all (or, bizarrely but legally, accepts the
10197 * user without actually issuing any prompts).
10198 * Give up on it entirely. */
10200 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10201 s->kbd_inter_refused = TRUE; /* don't try it again */
10206 * Loop while the server continues to send INFO_REQUESTs.
10208 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10210 char *name, *inst, *lang;
10211 int name_len, inst_len, lang_len;
10215 * We've got a fresh USERAUTH_INFO_REQUEST.
10216 * Get the preamble and start building a prompt.
10218 ssh_pkt_getstring(pktin, &name, &name_len);
10219 ssh_pkt_getstring(pktin, &inst, &inst_len);
10220 ssh_pkt_getstring(pktin, &lang, &lang_len);
10221 s->cur_prompt = new_prompts(ssh->frontend);
10222 s->cur_prompt->to_server = TRUE;
10225 * Get any prompt(s) from the packet.
10227 s->num_prompts = ssh_pkt_getuint32(pktin);
10228 for (i = 0; i < s->num_prompts; i++) {
10232 static char noprompt[] =
10233 "<server failed to send prompt>: ";
10235 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10236 echo = ssh2_pkt_getbool(pktin);
10239 prompt_len = lenof(noprompt)-1;
10241 add_prompt(s->cur_prompt,
10242 dupprintf("%.*s", prompt_len, prompt),
10247 /* FIXME: better prefix to distinguish from
10248 * local prompts? */
10249 s->cur_prompt->name =
10250 dupprintf("SSH server: %.*s", name_len, name);
10251 s->cur_prompt->name_reqd = TRUE;
10253 s->cur_prompt->name =
10254 dupstr("SSH server authentication");
10255 s->cur_prompt->name_reqd = FALSE;
10257 /* We add a prefix to try to make it clear that a prompt
10258 * has come from the server.
10259 * FIXME: ugly to print "Using..." in prompt _every_
10260 * time round. Can this be done more subtly? */
10261 /* Special case: for reasons best known to themselves,
10262 * some servers send k-i requests with no prompts and
10263 * nothing to display. Keep quiet in this case. */
10264 if (s->num_prompts || name_len || inst_len) {
10265 s->cur_prompt->instruction =
10266 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10267 inst_len ? "\n" : "", inst_len, inst);
10268 s->cur_prompt->instr_reqd = TRUE;
10270 s->cur_prompt->instr_reqd = FALSE;
10274 * Display any instructions, and get the user's
10278 int ret; /* not live over crReturn */
10279 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10282 crWaitUntilV(!pktin);
10283 ret = get_userpass_input(s->cur_prompt, in, inlen);
10288 * Failed to get responses. Terminate.
10290 free_prompts(s->cur_prompt);
10291 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10292 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10299 * Send the response(s) to the server.
10301 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10302 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10303 for (i=0; i < s->num_prompts; i++) {
10304 ssh2_pkt_addstring(s->pktout,
10305 s->cur_prompt->prompts[i]->result);
10307 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10310 * Free the prompts structure from this iteration.
10311 * If there's another, a new one will be allocated
10312 * when we return to the top of this while loop.
10314 free_prompts(s->cur_prompt);
10317 * Get the next packet in case it's another
10320 crWaitUntilV(pktin);
10325 * We should have SUCCESS or FAILURE now.
10329 } else if (s->can_passwd) {
10332 * Plain old password authentication.
10334 int ret; /* not live over crReturn */
10335 int changereq_first_time; /* not live over crReturn */
10337 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10339 s->cur_prompt = new_prompts(ssh->frontend);
10340 s->cur_prompt->to_server = TRUE;
10341 s->cur_prompt->name = dupstr("SSH password");
10342 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10347 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10350 crWaitUntilV(!pktin);
10351 ret = get_userpass_input(s->cur_prompt, in, inlen);
10356 * Failed to get responses. Terminate.
10358 free_prompts(s->cur_prompt);
10359 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10360 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10365 * Squirrel away the password. (We may need it later if
10366 * asked to change it.)
10368 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10369 free_prompts(s->cur_prompt);
10372 * Send the password packet.
10374 * We pad out the password packet to 256 bytes to make
10375 * it harder for an attacker to find the length of the
10378 * Anyone using a password longer than 256 bytes
10379 * probably doesn't have much to worry about from
10380 * people who find out how long their password is!
10382 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10383 ssh2_pkt_addstring(s->pktout, ssh->username);
10384 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10385 /* service requested */
10386 ssh2_pkt_addstring(s->pktout, "password");
10387 ssh2_pkt_addbool(s->pktout, FALSE);
10388 ssh2_pkt_addstring(s->pktout, s->password);
10389 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10390 logevent("Sent password");
10391 s->type = AUTH_TYPE_PASSWORD;
10394 * Wait for next packet, in case it's a password change
10397 crWaitUntilV(pktin);
10398 changereq_first_time = TRUE;
10400 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10403 * We're being asked for a new password
10404 * (perhaps not for the first time).
10405 * Loop until the server accepts it.
10408 int got_new = FALSE; /* not live over crReturn */
10409 char *prompt; /* not live over crReturn */
10410 int prompt_len; /* not live over crReturn */
10414 if (changereq_first_time)
10415 msg = "Server requested password change";
10417 msg = "Server rejected new password";
10419 c_write_str(ssh, msg);
10420 c_write_str(ssh, "\r\n");
10423 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10425 s->cur_prompt = new_prompts(ssh->frontend);
10426 s->cur_prompt->to_server = TRUE;
10427 s->cur_prompt->name = dupstr("New SSH password");
10428 s->cur_prompt->instruction =
10429 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10430 s->cur_prompt->instr_reqd = TRUE;
10432 * There's no explicit requirement in the protocol
10433 * for the "old" passwords in the original and
10434 * password-change messages to be the same, and
10435 * apparently some Cisco kit supports password change
10436 * by the user entering a blank password originally
10437 * and the real password subsequently, so,
10438 * reluctantly, we prompt for the old password again.
10440 * (On the other hand, some servers don't even bother
10441 * to check this field.)
10443 add_prompt(s->cur_prompt,
10444 dupstr("Current password (blank for previously entered password): "),
10446 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10448 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10452 * Loop until the user manages to enter the same
10457 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10460 crWaitUntilV(!pktin);
10461 ret = get_userpass_input(s->cur_prompt, in, inlen);
10466 * Failed to get responses. Terminate.
10468 /* burn the evidence */
10469 free_prompts(s->cur_prompt);
10470 smemclr(s->password, strlen(s->password));
10471 sfree(s->password);
10472 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10473 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10479 * If the user specified a new original password
10480 * (IYSWIM), overwrite any previously specified
10482 * (A side effect is that the user doesn't have to
10483 * re-enter it if they louse up the new password.)
10485 if (s->cur_prompt->prompts[0]->result[0]) {
10486 smemclr(s->password, strlen(s->password));
10487 /* burn the evidence */
10488 sfree(s->password);
10490 dupstr(s->cur_prompt->prompts[0]->result);
10494 * Check the two new passwords match.
10496 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10497 s->cur_prompt->prompts[2]->result)
10500 /* They don't. Silly user. */
10501 c_write_str(ssh, "Passwords do not match\r\n");
10506 * Send the new password (along with the old one).
10507 * (see above for padding rationale)
10509 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10510 ssh2_pkt_addstring(s->pktout, ssh->username);
10511 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10512 /* service requested */
10513 ssh2_pkt_addstring(s->pktout, "password");
10514 ssh2_pkt_addbool(s->pktout, TRUE);
10515 ssh2_pkt_addstring(s->pktout, s->password);
10516 ssh2_pkt_addstring(s->pktout,
10517 s->cur_prompt->prompts[1]->result);
10518 free_prompts(s->cur_prompt);
10519 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10520 logevent("Sent new password");
10523 * Now see what the server has to say about it.
10524 * (If it's CHANGEREQ again, it's not happy with the
10527 crWaitUntilV(pktin);
10528 changereq_first_time = FALSE;
10533 * We need to reexamine the current pktin at the top
10534 * of the loop. Either:
10535 * - we weren't asked to change password at all, in
10536 * which case it's a SUCCESS or FAILURE with the
10538 * - we sent a new password, and the server was
10539 * either OK with it (SUCCESS or FAILURE w/partial
10540 * success) or unhappy with the _old_ password
10541 * (FAILURE w/o partial success)
10542 * In any of these cases, we go back to the top of
10543 * the loop and start again.
10548 * We don't need the old password any more, in any
10549 * case. Burn the evidence.
10551 smemclr(s->password, strlen(s->password));
10552 sfree(s->password);
10555 char *str = dupprintf("No supported authentication methods available"
10556 " (server sent: %.*s)",
10559 ssh_disconnect(ssh, str,
10560 "No supported authentication methods available",
10561 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10571 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10573 /* Clear up various bits and pieces from authentication. */
10574 if (s->publickey_blob) {
10575 sfree(s->publickey_algorithm);
10576 sfree(s->publickey_blob);
10577 sfree(s->publickey_comment);
10579 if (s->agent_response)
10580 sfree(s->agent_response);
10582 if (s->userauth_success && !ssh->bare_connection) {
10584 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10585 * packets since. Signal the transport layer to consider enacting
10586 * delayed compression.
10588 * (Relying on we_are_in is not sufficient, as
10589 * draft-miller-secsh-compression-delayed is quite clear that it
10590 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10591 * become set for other reasons.)
10593 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10596 ssh->channels = newtree234(ssh_channelcmp);
10599 * Set up handlers for some connection protocol messages, so we
10600 * don't have to handle them repeatedly in this coroutine.
10602 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10603 ssh2_msg_channel_window_adjust;
10604 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10605 ssh2_msg_global_request;
10608 * Create the main session channel.
10610 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10611 ssh->mainchan = NULL;
10613 ssh->mainchan = snew(struct ssh_channel);
10614 ssh->mainchan->ssh = ssh;
10615 ssh_channel_init(ssh->mainchan);
10617 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10619 * Just start a direct-tcpip channel and use it as the main
10622 ssh_send_port_open(ssh->mainchan,
10623 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10624 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10626 ssh->ncmode = TRUE;
10628 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10629 logevent("Opening session as main channel");
10630 ssh2_pkt_send(ssh, s->pktout);
10631 ssh->ncmode = FALSE;
10633 crWaitUntilV(pktin);
10634 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10635 bombout(("Server refused to open channel"));
10637 /* FIXME: error data comes back in FAILURE packet */
10639 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10640 bombout(("Server's channel confirmation cited wrong channel"));
10643 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10644 ssh->mainchan->halfopen = FALSE;
10645 ssh->mainchan->type = CHAN_MAINSESSION;
10646 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10647 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10648 update_specials_menu(ssh->frontend);
10649 logevent("Opened main channel");
10653 * Now we have a channel, make dispatch table entries for
10654 * general channel-based messages.
10656 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10657 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10658 ssh2_msg_channel_data;
10659 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10660 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10661 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10662 ssh2_msg_channel_open_confirmation;
10663 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10664 ssh2_msg_channel_open_failure;
10665 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10666 ssh2_msg_channel_request;
10667 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10668 ssh2_msg_channel_open;
10669 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10670 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10673 * Now the connection protocol is properly up and running, with
10674 * all those dispatch table entries, so it's safe to let
10675 * downstreams start trying to open extra channels through us.
10677 if (ssh->connshare)
10678 share_activate(ssh->connshare, ssh->v_s);
10680 if (ssh->mainchan && ssh_is_simple(ssh)) {
10682 * This message indicates to the server that we promise
10683 * not to try to run any other channel in parallel with
10684 * this one, so it's safe for it to advertise a very large
10685 * window and leave the flow control to TCP.
10687 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10688 "simple@putty.projects.tartarus.org",
10690 ssh2_pkt_send(ssh, s->pktout);
10694 * Enable port forwardings.
10696 ssh_setup_portfwd(ssh, ssh->conf);
10698 if (ssh->mainchan && !ssh->ncmode) {
10700 * Send the CHANNEL_REQUESTS for the main session channel.
10701 * Each one is handled by its own little asynchronous
10705 /* Potentially enable X11 forwarding. */
10706 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10708 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10710 if (!ssh->x11disp) {
10711 /* FIXME: return an error message from x11_setup_display */
10712 logevent("X11 forwarding not enabled: unable to"
10713 " initialise X display");
10715 ssh->x11auth = x11_invent_fake_auth
10716 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10717 ssh->x11auth->disp = ssh->x11disp;
10719 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10723 /* Potentially enable agent forwarding. */
10724 if (ssh_agent_forwarding_permitted(ssh))
10725 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10727 /* Now allocate a pty for the session. */
10728 if (!conf_get_int(ssh->conf, CONF_nopty))
10729 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10731 /* Send environment variables. */
10732 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10735 * Start a shell or a remote command. We may have to attempt
10736 * this twice if the config data has provided a second choice
10743 if (ssh->fallback_cmd) {
10744 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10745 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10747 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10748 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10752 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10753 ssh2_response_authconn, NULL);
10754 ssh2_pkt_addstring(s->pktout, cmd);
10756 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10757 ssh2_response_authconn, NULL);
10758 ssh2_pkt_addstring(s->pktout, cmd);
10760 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10761 ssh2_response_authconn, NULL);
10763 ssh2_pkt_send(ssh, s->pktout);
10765 crWaitUntilV(pktin);
10767 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10768 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10769 bombout(("Unexpected response to shell/command request:"
10770 " packet type %d", pktin->type));
10774 * We failed to start the command. If this is the
10775 * fallback command, we really are finished; if it's
10776 * not, and if the fallback command exists, try falling
10777 * back to it before complaining.
10779 if (!ssh->fallback_cmd &&
10780 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10781 logevent("Primary command failed; attempting fallback");
10782 ssh->fallback_cmd = TRUE;
10785 bombout(("Server refused to start a shell/command"));
10788 logevent("Started a shell/command");
10793 ssh->editing = ssh->echoing = TRUE;
10796 ssh->state = SSH_STATE_SESSION;
10797 if (ssh->size_needed)
10798 ssh_size(ssh, ssh->term_width, ssh->term_height);
10799 if (ssh->eof_needed)
10800 ssh_special(ssh, TS_EOF);
10806 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10814 * _All_ the connection-layer packets we expect to
10815 * receive are now handled by the dispatch table.
10816 * Anything that reaches here must be bogus.
10819 bombout(("Strange packet received: type %d", pktin->type));
10821 } else if (ssh->mainchan) {
10823 * We have spare data. Add it to the channel buffer.
10825 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10833 * Handlers for SSH-2 messages that might arrive at any moment.
10835 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10837 /* log reason code in disconnect message */
10839 int reason, msglen;
10841 reason = ssh_pkt_getuint32(pktin);
10842 ssh_pkt_getstring(pktin, &msg, &msglen);
10844 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10845 buf = dupprintf("Received disconnect message (%s)",
10846 ssh2_disconnect_reasons[reason]);
10848 buf = dupprintf("Received disconnect message (unknown"
10849 " type %d)", reason);
10853 buf = dupprintf("Disconnection message text: %.*s",
10854 msglen, NULLTOEMPTY(msg));
10856 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10858 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10859 ssh2_disconnect_reasons[reason] : "unknown",
10860 msglen, NULLTOEMPTY(msg)));
10864 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10866 /* log the debug message */
10870 /* XXX maybe we should actually take notice of the return value */
10871 ssh2_pkt_getbool(pktin);
10872 ssh_pkt_getstring(pktin, &msg, &msglen);
10874 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10877 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10879 do_ssh2_transport(ssh, NULL, 0, pktin);
10883 * Called if we receive a packet that isn't allowed by the protocol.
10884 * This only applies to packets whose meaning PuTTY understands.
10885 * Entirely unknown packets are handled below.
10887 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10889 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10890 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10892 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10896 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10898 struct Packet *pktout;
10899 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10900 ssh2_pkt_adduint32(pktout, pktin->sequence);
10902 * UNIMPLEMENTED messages MUST appear in the same order as the
10903 * messages they respond to. Hence, never queue them.
10905 ssh2_pkt_send_noqueue(ssh, pktout);
10909 * Handle the top-level SSH-2 protocol.
10911 static void ssh2_protocol_setup(Ssh ssh)
10916 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10918 for (i = 0; i < 256; i++)
10919 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10922 * Initially, we only accept transport messages (and a few generic
10923 * ones). do_ssh2_authconn will add more when it starts.
10924 * Messages that are understood but not currently acceptable go to
10925 * ssh2_msg_unexpected.
10927 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10928 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10929 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10930 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10931 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10932 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10933 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10934 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10935 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10936 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10937 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10938 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10939 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10940 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10941 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10942 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10943 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10944 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10945 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10946 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10947 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10948 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10949 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10950 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10951 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10952 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10953 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10954 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10955 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10956 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10957 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10958 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10959 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10962 * These messages have a special handler from the start.
10964 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10965 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10966 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10969 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10974 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10976 for (i = 0; i < 256; i++)
10977 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10980 * Initially, we set all ssh-connection messages to 'unexpected';
10981 * do_ssh2_authconn will fill things in properly. We also handle a
10982 * couple of messages from the transport protocol which aren't
10983 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10986 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10987 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10988 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10990 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10991 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10992 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10994 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10995 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10996 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10997 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10998 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10999 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11001 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11004 * These messages have a special handler from the start.
11006 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11007 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11008 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11011 static void ssh2_timer(void *ctx, unsigned long now)
11013 Ssh ssh = (Ssh)ctx;
11015 if (ssh->state == SSH_STATE_CLOSED)
11018 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11019 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11020 now == ssh->next_rekey) {
11021 do_ssh2_transport(ssh, "timeout", -1, NULL);
11025 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11026 struct Packet *pktin)
11028 const unsigned char *in = (const unsigned char *)vin;
11029 if (ssh->state == SSH_STATE_CLOSED)
11033 ssh->incoming_data_size += pktin->encrypted_len;
11034 if (!ssh->kex_in_progress &&
11035 ssh->max_data_size != 0 &&
11036 ssh->incoming_data_size > ssh->max_data_size)
11037 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11041 ssh->packet_dispatch[pktin->type](ssh, pktin);
11042 else if (!ssh->protocol_initial_phase_done)
11043 do_ssh2_transport(ssh, in, inlen, pktin);
11045 do_ssh2_authconn(ssh, in, inlen, pktin);
11048 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11049 struct Packet *pktin)
11051 const unsigned char *in = (const unsigned char *)vin;
11052 if (ssh->state == SSH_STATE_CLOSED)
11056 ssh->packet_dispatch[pktin->type](ssh, pktin);
11058 do_ssh2_authconn(ssh, in, inlen, pktin);
11061 static void ssh_cache_conf_values(Ssh ssh)
11063 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11067 * Called to set up the connection.
11069 * Returns an error message, or NULL on success.
11071 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11073 const char *host, int port, char **realhost,
11074 int nodelay, int keepalive)
11079 ssh = snew(struct ssh_tag);
11080 ssh->conf = conf_copy(conf);
11081 ssh_cache_conf_values(ssh);
11082 ssh->version = 0; /* when not ready yet */
11084 ssh->cipher = NULL;
11085 ssh->v1_cipher_ctx = NULL;
11086 ssh->crcda_ctx = NULL;
11087 ssh->cscipher = NULL;
11088 ssh->cs_cipher_ctx = NULL;
11089 ssh->sccipher = NULL;
11090 ssh->sc_cipher_ctx = NULL;
11092 ssh->cs_mac_ctx = NULL;
11094 ssh->sc_mac_ctx = NULL;
11095 ssh->cscomp = NULL;
11096 ssh->cs_comp_ctx = NULL;
11097 ssh->sccomp = NULL;
11098 ssh->sc_comp_ctx = NULL;
11100 ssh->kex_ctx = NULL;
11101 ssh->hostkey = NULL;
11102 ssh->hostkey_str = NULL;
11103 ssh->exitcode = -1;
11104 ssh->close_expected = FALSE;
11105 ssh->clean_exit = FALSE;
11106 ssh->state = SSH_STATE_PREPACKET;
11107 ssh->size_needed = FALSE;
11108 ssh->eof_needed = FALSE;
11110 ssh->logctx = NULL;
11111 ssh->deferred_send_data = NULL;
11112 ssh->deferred_len = 0;
11113 ssh->deferred_size = 0;
11114 ssh->fallback_cmd = 0;
11115 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11116 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11117 ssh->x11disp = NULL;
11118 ssh->x11auth = NULL;
11119 ssh->x11authtree = newtree234(x11_authcmp);
11120 ssh->v1_compressing = FALSE;
11121 ssh->v2_outgoing_sequence = 0;
11122 ssh->ssh1_rdpkt_crstate = 0;
11123 ssh->ssh2_rdpkt_crstate = 0;
11124 ssh->ssh2_bare_rdpkt_crstate = 0;
11125 ssh->ssh_gotdata_crstate = 0;
11126 ssh->do_ssh1_connection_crstate = 0;
11127 ssh->do_ssh_init_state = NULL;
11128 ssh->do_ssh_connection_init_state = NULL;
11129 ssh->do_ssh1_login_state = NULL;
11130 ssh->do_ssh2_transport_state = NULL;
11131 ssh->do_ssh2_authconn_state = NULL;
11134 ssh->mainchan = NULL;
11135 ssh->throttled_all = 0;
11136 ssh->v1_stdout_throttling = 0;
11138 ssh->queuelen = ssh->queuesize = 0;
11139 ssh->queueing = FALSE;
11140 ssh->qhead = ssh->qtail = NULL;
11141 ssh->deferred_rekey_reason = NULL;
11142 bufchain_init(&ssh->queued_incoming_data);
11143 ssh->frozen = FALSE;
11144 ssh->username = NULL;
11145 ssh->sent_console_eof = FALSE;
11146 ssh->got_pty = FALSE;
11147 ssh->bare_connection = FALSE;
11148 ssh->X11_fwd_enabled = FALSE;
11149 ssh->connshare = NULL;
11150 ssh->attempting_connshare = FALSE;
11151 ssh->session_started = FALSE;
11152 ssh->specials = NULL;
11153 ssh->n_uncert_hostkeys = 0;
11154 ssh->cross_certifying = FALSE;
11156 *backend_handle = ssh;
11159 if (crypto_startup() == 0)
11160 return "Microsoft high encryption pack not installed!";
11163 ssh->frontend = frontend_handle;
11164 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11165 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11167 ssh->channels = NULL;
11168 ssh->rportfwds = NULL;
11169 ssh->portfwds = NULL;
11174 ssh->conn_throttle_count = 0;
11175 ssh->overall_bufsize = 0;
11176 ssh->fallback_cmd = 0;
11178 ssh->protocol = NULL;
11180 ssh->protocol_initial_phase_done = FALSE;
11182 ssh->pinger = NULL;
11184 ssh->incoming_data_size = ssh->outgoing_data_size =
11185 ssh->deferred_data_size = 0L;
11186 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11187 CONF_ssh_rekey_data));
11188 ssh->kex_in_progress = FALSE;
11191 ssh->gsslibs = NULL;
11194 random_ref(); /* do this now - may be needed by sharing setup code */
11196 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11205 static void ssh_free(void *handle)
11207 Ssh ssh = (Ssh) handle;
11208 struct ssh_channel *c;
11209 struct ssh_rportfwd *pf;
11210 struct X11FakeAuth *auth;
11212 if (ssh->v1_cipher_ctx)
11213 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11214 if (ssh->cs_cipher_ctx)
11215 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11216 if (ssh->sc_cipher_ctx)
11217 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11218 if (ssh->cs_mac_ctx)
11219 ssh->csmac->free_context(ssh->cs_mac_ctx);
11220 if (ssh->sc_mac_ctx)
11221 ssh->scmac->free_context(ssh->sc_mac_ctx);
11222 if (ssh->cs_comp_ctx) {
11224 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11226 zlib_compress_cleanup(ssh->cs_comp_ctx);
11228 if (ssh->sc_comp_ctx) {
11230 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11232 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11235 dh_cleanup(ssh->kex_ctx);
11236 sfree(ssh->savedhost);
11238 while (ssh->queuelen-- > 0)
11239 ssh_free_packet(ssh->queue[ssh->queuelen]);
11242 while (ssh->qhead) {
11243 struct queued_handler *qh = ssh->qhead;
11244 ssh->qhead = qh->next;
11247 ssh->qhead = ssh->qtail = NULL;
11249 if (ssh->channels) {
11250 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11253 if (c->u.x11.xconn != NULL)
11254 x11_close(c->u.x11.xconn);
11256 case CHAN_SOCKDATA:
11257 if (c->u.pfd.pf != NULL)
11258 pfd_close(c->u.pfd.pf);
11261 if (ssh->version == 2) {
11262 struct outstanding_channel_request *ocr, *nocr;
11263 ocr = c->v.v2.chanreq_head;
11265 ocr->handler(c, NULL, ocr->ctx);
11270 bufchain_clear(&c->v.v2.outbuffer);
11274 freetree234(ssh->channels);
11275 ssh->channels = NULL;
11278 if (ssh->connshare)
11279 sharestate_free(ssh->connshare);
11281 if (ssh->rportfwds) {
11282 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11284 freetree234(ssh->rportfwds);
11285 ssh->rportfwds = NULL;
11287 sfree(ssh->deferred_send_data);
11289 x11_free_display(ssh->x11disp);
11290 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11291 x11_free_fake_auth(auth);
11292 freetree234(ssh->x11authtree);
11293 sfree(ssh->do_ssh_init_state);
11294 sfree(ssh->do_ssh1_login_state);
11295 sfree(ssh->do_ssh2_transport_state);
11296 sfree(ssh->do_ssh2_authconn_state);
11299 sfree(ssh->fullhostname);
11300 sfree(ssh->hostkey_str);
11301 sfree(ssh->specials);
11302 if (ssh->crcda_ctx) {
11303 crcda_free_context(ssh->crcda_ctx);
11304 ssh->crcda_ctx = NULL;
11307 ssh_do_close(ssh, TRUE);
11308 expire_timer_context(ssh);
11310 pinger_free(ssh->pinger);
11311 bufchain_clear(&ssh->queued_incoming_data);
11312 sfree(ssh->username);
11313 conf_free(ssh->conf);
11316 ssh_gss_cleanup(ssh->gsslibs);
11324 * Reconfigure the SSH backend.
11326 static void ssh_reconfig(void *handle, Conf *conf)
11328 Ssh ssh = (Ssh) handle;
11329 const char *rekeying = NULL;
11330 int rekey_mandatory = FALSE;
11331 unsigned long old_max_data_size;
11334 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11336 ssh_setup_portfwd(ssh, conf);
11338 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11339 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11341 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11342 unsigned long now = GETTICKCOUNT();
11344 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11345 rekeying = "timeout shortened";
11347 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11351 old_max_data_size = ssh->max_data_size;
11352 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11353 CONF_ssh_rekey_data));
11354 if (old_max_data_size != ssh->max_data_size &&
11355 ssh->max_data_size != 0) {
11356 if (ssh->outgoing_data_size > ssh->max_data_size ||
11357 ssh->incoming_data_size > ssh->max_data_size)
11358 rekeying = "data limit lowered";
11361 if (conf_get_int(ssh->conf, CONF_compression) !=
11362 conf_get_int(conf, CONF_compression)) {
11363 rekeying = "compression setting changed";
11364 rekey_mandatory = TRUE;
11367 for (i = 0; i < CIPHER_MAX; i++)
11368 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11369 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11370 rekeying = "cipher settings changed";
11371 rekey_mandatory = TRUE;
11373 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11374 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11375 rekeying = "cipher settings changed";
11376 rekey_mandatory = TRUE;
11379 conf_free(ssh->conf);
11380 ssh->conf = conf_copy(conf);
11381 ssh_cache_conf_values(ssh);
11383 if (!ssh->bare_connection && rekeying) {
11384 if (!ssh->kex_in_progress) {
11385 do_ssh2_transport(ssh, rekeying, -1, NULL);
11386 } else if (rekey_mandatory) {
11387 ssh->deferred_rekey_reason = rekeying;
11393 * Called to send data down the SSH connection.
11395 static int ssh_send(void *handle, const char *buf, int len)
11397 Ssh ssh = (Ssh) handle;
11399 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11402 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11404 return ssh_sendbuffer(ssh);
11408 * Called to query the current amount of buffered stdin data.
11410 static int ssh_sendbuffer(void *handle)
11412 Ssh ssh = (Ssh) handle;
11413 int override_value;
11415 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11419 * If the SSH socket itself has backed up, add the total backup
11420 * size on that to any individual buffer on the stdin channel.
11422 override_value = 0;
11423 if (ssh->throttled_all)
11424 override_value = ssh->overall_bufsize;
11426 if (ssh->version == 1) {
11427 return override_value;
11428 } else if (ssh->version == 2) {
11429 if (!ssh->mainchan)
11430 return override_value;
11432 return (override_value +
11433 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11440 * Called to set the size of the window from SSH's POV.
11442 static void ssh_size(void *handle, int width, int height)
11444 Ssh ssh = (Ssh) handle;
11445 struct Packet *pktout;
11447 ssh->term_width = width;
11448 ssh->term_height = height;
11450 switch (ssh->state) {
11451 case SSH_STATE_BEFORE_SIZE:
11452 case SSH_STATE_PREPACKET:
11453 case SSH_STATE_CLOSED:
11454 break; /* do nothing */
11455 case SSH_STATE_INTERMED:
11456 ssh->size_needed = TRUE; /* buffer for later */
11458 case SSH_STATE_SESSION:
11459 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11460 if (ssh->version == 1) {
11461 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11462 PKT_INT, ssh->term_height,
11463 PKT_INT, ssh->term_width,
11464 PKT_INT, 0, PKT_INT, 0, PKT_END);
11465 } else if (ssh->mainchan) {
11466 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11468 ssh2_pkt_adduint32(pktout, ssh->term_width);
11469 ssh2_pkt_adduint32(pktout, ssh->term_height);
11470 ssh2_pkt_adduint32(pktout, 0);
11471 ssh2_pkt_adduint32(pktout, 0);
11472 ssh2_pkt_send(ssh, pktout);
11480 * Return a list of the special codes that make sense in this
11483 static const struct telnet_special *ssh_get_specials(void *handle)
11485 static const struct telnet_special ssh1_ignore_special[] = {
11486 {"IGNORE message", TS_NOP}
11488 static const struct telnet_special ssh2_ignore_special[] = {
11489 {"IGNORE message", TS_NOP},
11491 static const struct telnet_special ssh2_rekey_special[] = {
11492 {"Repeat key exchange", TS_REKEY},
11494 static const struct telnet_special ssh2_session_specials[] = {
11497 /* These are the signal names defined by RFC 4254.
11498 * They include all the ISO C signals, but are a subset of the POSIX
11499 * required signals. */
11500 {"SIGINT (Interrupt)", TS_SIGINT},
11501 {"SIGTERM (Terminate)", TS_SIGTERM},
11502 {"SIGKILL (Kill)", TS_SIGKILL},
11503 {"SIGQUIT (Quit)", TS_SIGQUIT},
11504 {"SIGHUP (Hangup)", TS_SIGHUP},
11505 {"More signals", TS_SUBMENU},
11506 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11507 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11508 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11509 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11510 {NULL, TS_EXITMENU}
11512 static const struct telnet_special specials_end[] = {
11513 {NULL, TS_EXITMENU}
11516 struct telnet_special *specials = NULL;
11517 int nspecials = 0, specialsize = 0;
11519 Ssh ssh = (Ssh) handle;
11521 sfree(ssh->specials);
11523 #define ADD_SPECIALS(name) do \
11525 int len = lenof(name); \
11526 if (nspecials + len > specialsize) { \
11527 specialsize = (nspecials + len) * 5 / 4 + 32; \
11528 specials = sresize(specials, specialsize, struct telnet_special); \
11530 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11531 nspecials += len; \
11534 if (ssh->version == 1) {
11535 /* Don't bother offering IGNORE if we've decided the remote
11536 * won't cope with it, since we wouldn't bother sending it if
11538 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11539 ADD_SPECIALS(ssh1_ignore_special);
11540 } else if (ssh->version == 2) {
11541 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11542 ADD_SPECIALS(ssh2_ignore_special);
11543 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11544 ADD_SPECIALS(ssh2_rekey_special);
11546 ADD_SPECIALS(ssh2_session_specials);
11548 if (ssh->n_uncert_hostkeys) {
11549 static const struct telnet_special uncert_start[] = {
11551 {"Cache new host key type", TS_SUBMENU},
11553 static const struct telnet_special uncert_end[] = {
11554 {NULL, TS_EXITMENU},
11558 ADD_SPECIALS(uncert_start);
11559 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11560 struct telnet_special uncert[1];
11561 const struct ssh_signkey *alg =
11562 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11563 uncert[0].name = alg->name;
11564 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11565 ADD_SPECIALS(uncert);
11567 ADD_SPECIALS(uncert_end);
11569 } /* else we're not ready yet */
11572 ADD_SPECIALS(specials_end);
11574 ssh->specials = specials;
11581 #undef ADD_SPECIALS
11585 * Send special codes. TS_EOF is useful for `plink', so you
11586 * can send an EOF and collect resulting output (e.g. `plink
11589 static void ssh_special(void *handle, Telnet_Special code)
11591 Ssh ssh = (Ssh) handle;
11592 struct Packet *pktout;
11594 if (code == TS_EOF) {
11595 if (ssh->state != SSH_STATE_SESSION) {
11597 * Buffer the EOF in case we are pre-SESSION, so we can
11598 * send it as soon as we reach SESSION.
11600 if (code == TS_EOF)
11601 ssh->eof_needed = TRUE;
11604 if (ssh->version == 1) {
11605 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11606 } else if (ssh->mainchan) {
11607 sshfwd_write_eof(ssh->mainchan);
11608 ssh->send_ok = 0; /* now stop trying to read from stdin */
11610 logevent("Sent EOF message");
11611 } else if (code == TS_PING || code == TS_NOP) {
11612 if (ssh->state == SSH_STATE_CLOSED
11613 || ssh->state == SSH_STATE_PREPACKET) return;
11614 if (ssh->version == 1) {
11615 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11616 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11618 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11619 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11620 ssh2_pkt_addstring_start(pktout);
11621 ssh2_pkt_send_noqueue(ssh, pktout);
11624 } else if (code == TS_REKEY) {
11625 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11626 ssh->version == 2) {
11627 do_ssh2_transport(ssh, "at user request", -1, NULL);
11629 } else if (code >= TS_LOCALSTART) {
11630 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11631 ssh->cross_certifying = TRUE;
11632 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11633 ssh->version == 2) {
11634 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11636 } else if (code == TS_BRK) {
11637 if (ssh->state == SSH_STATE_CLOSED
11638 || ssh->state == SSH_STATE_PREPACKET) return;
11639 if (ssh->version == 1) {
11640 logevent("Unable to send BREAK signal in SSH-1");
11641 } else if (ssh->mainchan) {
11642 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11643 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11644 ssh2_pkt_send(ssh, pktout);
11647 /* Is is a POSIX signal? */
11648 const char *signame = NULL;
11649 if (code == TS_SIGABRT) signame = "ABRT";
11650 if (code == TS_SIGALRM) signame = "ALRM";
11651 if (code == TS_SIGFPE) signame = "FPE";
11652 if (code == TS_SIGHUP) signame = "HUP";
11653 if (code == TS_SIGILL) signame = "ILL";
11654 if (code == TS_SIGINT) signame = "INT";
11655 if (code == TS_SIGKILL) signame = "KILL";
11656 if (code == TS_SIGPIPE) signame = "PIPE";
11657 if (code == TS_SIGQUIT) signame = "QUIT";
11658 if (code == TS_SIGSEGV) signame = "SEGV";
11659 if (code == TS_SIGTERM) signame = "TERM";
11660 if (code == TS_SIGUSR1) signame = "USR1";
11661 if (code == TS_SIGUSR2) signame = "USR2";
11662 /* The SSH-2 protocol does in principle support arbitrary named
11663 * signals, including signame@domain, but we don't support those. */
11665 /* It's a signal. */
11666 if (ssh->version == 2 && ssh->mainchan) {
11667 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11668 ssh2_pkt_addstring(pktout, signame);
11669 ssh2_pkt_send(ssh, pktout);
11670 logeventf(ssh, "Sent signal SIG%s", signame);
11673 /* Never heard of it. Do nothing */
11678 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11680 Ssh ssh = (Ssh) handle;
11681 struct ssh_channel *c;
11682 c = snew(struct ssh_channel);
11685 ssh_channel_init(c);
11686 c->halfopen = TRUE;
11687 c->type = CHAN_SOCKDATA;/* identify channel type */
11692 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11694 struct ssh_channel *c;
11695 c = snew(struct ssh_channel);
11698 ssh_channel_init(c);
11699 c->type = CHAN_SHARING;
11700 c->u.sharing.ctx = sharing_ctx;
11704 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11706 struct ssh_channel *c;
11708 c = find234(ssh->channels, &localid, ssh_channelfind);
11710 ssh_channel_destroy(c);
11713 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11714 const void *data, int datalen,
11715 const char *additional_log_text)
11717 struct Packet *pkt;
11719 pkt = ssh2_pkt_init(type);
11720 pkt->downstream_id = id;
11721 pkt->additional_log_text = additional_log_text;
11722 ssh2_pkt_adddata(pkt, data, datalen);
11723 ssh2_pkt_send(ssh, pkt);
11727 * This is called when stdout/stderr (the entity to which
11728 * from_backend sends data) manages to clear some backlog.
11730 static void ssh_unthrottle(void *handle, int bufsize)
11732 Ssh ssh = (Ssh) handle;
11734 if (ssh->version == 1) {
11735 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11736 ssh->v1_stdout_throttling = 0;
11737 ssh_throttle_conn(ssh, -1);
11741 ssh_channel_unthrottle(ssh->mainchan, bufsize);
11745 * Now process any SSH connection data that was stashed in our
11746 * queue while we were frozen.
11748 ssh_process_queued_incoming_data(ssh);
11751 void ssh_send_port_open(void *channel, const char *hostname, int port,
11754 struct ssh_channel *c = (struct ssh_channel *)channel;
11756 struct Packet *pktout;
11758 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11760 if (ssh->version == 1) {
11761 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11762 PKT_INT, c->localid,
11765 /* PKT_STR, <org:orgport>, */
11768 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11770 char *trimmed_host = host_strduptrim(hostname);
11771 ssh2_pkt_addstring(pktout, trimmed_host);
11772 sfree(trimmed_host);
11774 ssh2_pkt_adduint32(pktout, port);
11776 * We make up values for the originator data; partly it's
11777 * too much hassle to keep track, and partly I'm not
11778 * convinced the server should be told details like that
11779 * about my local network configuration.
11780 * The "originator IP address" is syntactically a numeric
11781 * IP address, and some servers (e.g., Tectia) get upset
11782 * if it doesn't match this syntax.
11784 ssh2_pkt_addstring(pktout, "0.0.0.0");
11785 ssh2_pkt_adduint32(pktout, 0);
11786 ssh2_pkt_send(ssh, pktout);
11790 static int ssh_connected(void *handle)
11792 Ssh ssh = (Ssh) handle;
11793 return ssh->s != NULL;
11796 static int ssh_sendok(void *handle)
11798 Ssh ssh = (Ssh) handle;
11799 return ssh->send_ok;
11802 static int ssh_ldisc(void *handle, int option)
11804 Ssh ssh = (Ssh) handle;
11805 if (option == LD_ECHO)
11806 return ssh->echoing;
11807 if (option == LD_EDIT)
11808 return ssh->editing;
11812 static void ssh_provide_ldisc(void *handle, void *ldisc)
11814 Ssh ssh = (Ssh) handle;
11815 ssh->ldisc = ldisc;
11818 static void ssh_provide_logctx(void *handle, void *logctx)
11820 Ssh ssh = (Ssh) handle;
11821 ssh->logctx = logctx;
11824 static int ssh_return_exitcode(void *handle)
11826 Ssh ssh = (Ssh) handle;
11827 if (ssh->s != NULL)
11830 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11834 * cfg_info for SSH is the protocol running in this session.
11835 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11836 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11838 static int ssh_cfg_info(void *handle)
11840 Ssh ssh = (Ssh) handle;
11841 if (ssh->version == 0)
11842 return 0; /* don't know yet */
11843 else if (ssh->bare_connection)
11846 return ssh->version;
11850 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11851 * that fails. This variable is the means by which scp.c can reach
11852 * into the SSH code and find out which one it got.
11854 extern int ssh_fallback_cmd(void *handle)
11856 Ssh ssh = (Ssh) handle;
11857 return ssh->fallback_cmd;
11860 Backend ssh_backend = {
11870 ssh_return_exitcode,
11874 ssh_provide_logctx,
11877 ssh_test_for_upstream,