29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
92 static const struct ssh_ttymode {
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "IUTF8", 42, TTY_OP_BOOL },
129 { "ISIG", 50, TTY_OP_BOOL },
130 { "ICANON", 51, TTY_OP_BOOL },
131 { "XCASE", 52, TTY_OP_BOOL },
132 { "ECHO", 53, TTY_OP_BOOL },
133 { "ECHOE", 54, TTY_OP_BOOL },
134 { "ECHOK", 55, TTY_OP_BOOL },
135 { "ECHONL", 56, TTY_OP_BOOL },
136 { "NOFLSH", 57, TTY_OP_BOOL },
137 { "TOSTOP", 58, TTY_OP_BOOL },
138 { "IEXTEN", 59, TTY_OP_BOOL },
139 { "ECHOCTL", 60, TTY_OP_BOOL },
140 { "ECHOKE", 61, TTY_OP_BOOL },
141 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
142 { "OPOST", 70, TTY_OP_BOOL },
143 { "OLCUC", 71, TTY_OP_BOOL },
144 { "ONLCR", 72, TTY_OP_BOOL },
145 { "OCRNL", 73, TTY_OP_BOOL },
146 { "ONOCR", 74, TTY_OP_BOOL },
147 { "ONLRET", 75, TTY_OP_BOOL },
148 { "CS7", 90, TTY_OP_BOOL },
149 { "CS8", 91, TTY_OP_BOOL },
150 { "PARENB", 92, TTY_OP_BOOL },
151 { "PARODD", 93, TTY_OP_BOOL }
154 /* Miscellaneous other tty-related constants. */
155 #define SSH_TTY_OP_END 0
156 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
157 #define SSH1_TTY_OP_ISPEED 192
158 #define SSH1_TTY_OP_OSPEED 193
159 #define SSH2_TTY_OP_ISPEED 128
160 #define SSH2_TTY_OP_OSPEED 129
162 /* Helper functions for parsing tty-related config. */
163 static unsigned int ssh_tty_parse_specchar(char *s)
168 ret = ctrlparse(s, &next);
169 if (!next) ret = s[0];
171 ret = 255; /* special value meaning "don't set" */
175 static unsigned int ssh_tty_parse_boolean(char *s)
177 if (stricmp(s, "yes") == 0 ||
178 stricmp(s, "on") == 0 ||
179 stricmp(s, "true") == 0 ||
180 stricmp(s, "+") == 0)
182 else if (stricmp(s, "no") == 0 ||
183 stricmp(s, "off") == 0 ||
184 stricmp(s, "false") == 0 ||
185 stricmp(s, "-") == 0)
186 return 0; /* false */
188 return (atoi(s) != 0);
191 #define translate(x) if (type == x) return #x
192 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
193 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
194 static const char *ssh1_pkt_type(int type)
196 translate(SSH1_MSG_DISCONNECT);
197 translate(SSH1_SMSG_PUBLIC_KEY);
198 translate(SSH1_CMSG_SESSION_KEY);
199 translate(SSH1_CMSG_USER);
200 translate(SSH1_CMSG_AUTH_RSA);
201 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
202 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
203 translate(SSH1_CMSG_AUTH_PASSWORD);
204 translate(SSH1_CMSG_REQUEST_PTY);
205 translate(SSH1_CMSG_WINDOW_SIZE);
206 translate(SSH1_CMSG_EXEC_SHELL);
207 translate(SSH1_CMSG_EXEC_CMD);
208 translate(SSH1_SMSG_SUCCESS);
209 translate(SSH1_SMSG_FAILURE);
210 translate(SSH1_CMSG_STDIN_DATA);
211 translate(SSH1_SMSG_STDOUT_DATA);
212 translate(SSH1_SMSG_STDERR_DATA);
213 translate(SSH1_CMSG_EOF);
214 translate(SSH1_SMSG_EXIT_STATUS);
215 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
216 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
217 translate(SSH1_MSG_CHANNEL_DATA);
218 translate(SSH1_MSG_CHANNEL_CLOSE);
219 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
220 translate(SSH1_SMSG_X11_OPEN);
221 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
222 translate(SSH1_MSG_PORT_OPEN);
223 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
224 translate(SSH1_SMSG_AGENT_OPEN);
225 translate(SSH1_MSG_IGNORE);
226 translate(SSH1_CMSG_EXIT_CONFIRMATION);
227 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
228 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
229 translate(SSH1_MSG_DEBUG);
230 translate(SSH1_CMSG_REQUEST_COMPRESSION);
231 translate(SSH1_CMSG_AUTH_TIS);
232 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
234 translate(SSH1_CMSG_AUTH_CCARD);
235 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
236 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
239 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
247 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
248 translate(SSH2_MSG_DISCONNECT);
249 translate(SSH2_MSG_IGNORE);
250 translate(SSH2_MSG_UNIMPLEMENTED);
251 translate(SSH2_MSG_DEBUG);
252 translate(SSH2_MSG_SERVICE_REQUEST);
253 translate(SSH2_MSG_SERVICE_ACCEPT);
254 translate(SSH2_MSG_KEXINIT);
255 translate(SSH2_MSG_NEWKEYS);
256 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
263 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
266 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
267 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
268 translate(SSH2_MSG_USERAUTH_REQUEST);
269 translate(SSH2_MSG_USERAUTH_FAILURE);
270 translate(SSH2_MSG_USERAUTH_SUCCESS);
271 translate(SSH2_MSG_USERAUTH_BANNER);
272 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
273 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
274 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
275 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
276 translate(SSH2_MSG_GLOBAL_REQUEST);
277 translate(SSH2_MSG_REQUEST_SUCCESS);
278 translate(SSH2_MSG_REQUEST_FAILURE);
279 translate(SSH2_MSG_CHANNEL_OPEN);
280 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
281 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
282 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
283 translate(SSH2_MSG_CHANNEL_DATA);
284 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
285 translate(SSH2_MSG_CHANNEL_EOF);
286 translate(SSH2_MSG_CHANNEL_CLOSE);
287 translate(SSH2_MSG_CHANNEL_REQUEST);
288 translate(SSH2_MSG_CHANNEL_SUCCESS);
289 translate(SSH2_MSG_CHANNEL_FAILURE);
295 /* Enumeration values for fields in SSH-1 packets */
297 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
301 * Coroutine mechanics for the sillier bits of the code. If these
302 * macros look impenetrable to you, you might find it helpful to
305 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
307 * which explains the theory behind these macros.
309 * In particular, if you are getting `case expression not constant'
310 * errors when building with MS Visual Studio, this is because MS's
311 * Edit and Continue debugging feature causes their compiler to
312 * violate ANSI C. To disable Edit and Continue debugging:
314 * - right-click ssh.c in the FileView
316 * - select the C/C++ tab and the General category
317 * - under `Debug info:', select anything _other_ than `Program
318 * Database for Edit and Continue'.
320 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
321 #define crBeginState crBegin(s->crLine)
322 #define crStateP(t, v) \
324 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
326 #define crState(t) crStateP(t, ssh->t)
327 #define crFinish(z) } *crLine = 0; return (z); }
328 #define crFinishV } *crLine = 0; return; }
329 #define crFinishFree(z) } sfree(s); return (z); }
330 #define crFinishFreeV } sfree(s); return; }
331 #define crReturn(z) \
333 *crLine =__LINE__; return (z); case __LINE__:;\
337 *crLine=__LINE__; return; case __LINE__:;\
339 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
340 #define crStopV do{ *crLine = 0; return; }while(0)
341 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
342 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
346 static struct Packet *ssh1_pkt_init(int pkt_type);
347 static struct Packet *ssh2_pkt_init(int pkt_type);
348 static void ssh_pkt_ensure(struct Packet *, int length);
349 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
350 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
351 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
352 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
353 static void ssh_pkt_addstring_start(struct Packet *);
354 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
355 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
356 static void ssh_pkt_addstring(struct Packet *, const char *data);
357 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
358 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
359 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
360 static int ssh2_pkt_construct(Ssh, struct Packet *);
361 static void ssh2_pkt_send(Ssh, struct Packet *);
362 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
363 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
366 struct Packet *pktin);
367 static void ssh_channel_init(struct ssh_channel *c);
368 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin);
369 static void ssh_channel_got_eof(struct ssh_channel *c);
370 static void ssh2_channel_check_close(struct ssh_channel *c);
371 static void ssh_channel_destroy(struct ssh_channel *c);
372 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize);
373 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
376 * Buffer management constants. There are several of these for
377 * various different purposes:
379 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
380 * on a local data stream before we throttle the whole SSH
381 * connection (in SSH-1 only). Throttling the whole connection is
382 * pretty drastic so we set this high in the hope it won't
385 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
386 * on the SSH connection itself before we defensively throttle
387 * _all_ local data streams. This is pretty drastic too (though
388 * thankfully unlikely in SSH-2 since the window mechanism should
389 * ensure that the server never has any need to throttle its end
390 * of the connection), so we set this high as well.
392 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
395 * - OUR_V2_BIGWIN is the window size we advertise for the only
396 * channel in a simple connection. It must be <= INT_MAX.
398 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
399 * to the remote side. This actually has nothing to do with the
400 * size of the _packet_, but is instead a limit on the amount
401 * of data we're willing to receive in a single SSH2 channel
404 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
405 * _packet_ we're prepared to cope with. It must be a multiple
406 * of the cipher block size, and must be at least 35000.
409 #define SSH1_BUFFER_LIMIT 32768
410 #define SSH_MAX_BACKLOG 32768
411 #define OUR_V2_WINSIZE 16384
412 #define OUR_V2_BIGWIN 0x7fffffff
413 #define OUR_V2_MAXPKT 0x4000UL
414 #define OUR_V2_PACKETLIMIT 0x9000UL
416 struct ssh_signkey_with_user_pref_id {
417 const struct ssh_signkey *alg;
420 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
421 { &ssh_ecdsa_ed25519, HK_ED25519 },
422 { &ssh_ecdsa_nistp256, HK_ECDSA },
423 { &ssh_ecdsa_nistp384, HK_ECDSA },
424 { &ssh_ecdsa_nistp521, HK_ECDSA },
425 { &ssh_dss, HK_DSA },
426 { &ssh_rsa, HK_RSA },
429 const static struct ssh_mac *const macs[] = {
430 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
432 const static struct ssh_mac *const buggymacs[] = {
433 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
436 static void *ssh_comp_none_init(void)
440 static void ssh_comp_none_cleanup(void *handle)
443 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
444 unsigned char **outblock, int *outlen)
448 static int ssh_comp_none_disable(void *handle)
452 const static struct ssh_compress ssh_comp_none = {
454 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
455 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
456 ssh_comp_none_disable, NULL
458 extern const struct ssh_compress ssh_zlib;
459 const static struct ssh_compress *const compressions[] = {
460 &ssh_zlib, &ssh_comp_none
463 enum { /* channel types */
469 * CHAN_SHARING indicates a channel which is tracked here on
470 * behalf of a connection-sharing downstream. We do almost nothing
471 * with these channels ourselves: all messages relating to them
472 * get thrown straight to sshshare.c and passed on almost
473 * unmodified to downstream.
477 * CHAN_ZOMBIE is used to indicate a channel for which we've
478 * already destroyed the local data source: for instance, if a
479 * forwarded port experiences a socket error on the local side, we
480 * immediately destroy its local socket and turn the SSH channel
486 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
487 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
488 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
491 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
494 struct outstanding_channel_request {
495 cchandler_fn_t handler;
497 struct outstanding_channel_request *next;
501 * 2-3-4 tree storing channels.
504 Ssh ssh; /* pointer back to main context */
505 unsigned remoteid, localid;
507 /* True if we opened this channel but server hasn't confirmed. */
510 * In SSH-1, this value contains four bits:
512 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
513 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
514 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
515 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
517 * A channel is completely finished with when all four bits are set.
519 * In SSH-2, the four bits mean:
521 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
522 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
523 * 4 We have received SSH2_MSG_CHANNEL_EOF.
524 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
526 * A channel is completely finished with when we have both sent
527 * and received CLOSE.
529 * The symbolic constants below use the SSH-2 terminology, which
530 * is a bit confusing in SSH-1, but we have to use _something_.
532 #define CLOSES_SENT_EOF 1
533 #define CLOSES_SENT_CLOSE 2
534 #define CLOSES_RCVD_EOF 4
535 #define CLOSES_RCVD_CLOSE 8
539 * This flag indicates that an EOF is pending on the outgoing side
540 * of the channel: that is, wherever we're getting the data for
541 * this channel has sent us some data followed by EOF. We can't
542 * actually send the EOF until we've finished sending the data, so
543 * we set this flag instead to remind us to do so once our buffer
549 * True if this channel is causing the underlying connection to be
554 struct ssh2_data_channel {
556 unsigned remwindow, remmaxpkt;
557 /* locwindow is signed so we can cope with excess data. */
558 int locwindow, locmaxwin;
560 * remlocwin is the amount of local window that we think
561 * the remote end had available to it after it sent the
562 * last data packet or window adjust ack.
566 * These store the list of channel requests that haven't
569 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
570 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
574 struct ssh_agent_channel {
575 unsigned char *message;
576 unsigned char msglen[4];
577 unsigned lensofar, totallen;
578 int outstanding_requests;
580 struct ssh_x11_channel {
581 struct X11Connection *xconn;
584 struct ssh_pfd_channel {
585 struct PortForwarding *pf;
587 struct ssh_sharing_channel {
594 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
595 * use this structure in different ways, reflecting SSH-2's
596 * altogether saner approach to port forwarding.
598 * In SSH-1, you arrange a remote forwarding by sending the server
599 * the remote port number, and the local destination host:port.
600 * When a connection comes in, the server sends you back that
601 * host:port pair, and you connect to it. This is a ready-made
602 * security hole if you're not on the ball: a malicious server
603 * could send you back _any_ host:port pair, so if you trustingly
604 * connect to the address it gives you then you've just opened the
605 * entire inside of your corporate network just by connecting
606 * through it to a dodgy SSH server. Hence, we must store a list of
607 * host:port pairs we _are_ trying to forward to, and reject a
608 * connection request from the server if it's not in the list.
610 * In SSH-2, each side of the connection minds its own business and
611 * doesn't send unnecessary information to the other. You arrange a
612 * remote forwarding by sending the server just the remote port
613 * number. When a connection comes in, the server tells you which
614 * of its ports was connected to; and _you_ have to remember what
615 * local host:port pair went with that port number.
617 * Hence, in SSH-1 this structure is indexed by destination
618 * host:port pair, whereas in SSH-2 it is indexed by source port.
620 struct ssh_portfwd; /* forward declaration */
622 struct ssh_rportfwd {
623 unsigned sport, dport;
627 struct ssh_portfwd *pfrec;
630 static void free_rportfwd(struct ssh_rportfwd *pf)
633 sfree(pf->sportdesc);
641 * Separately to the rportfwd tree (which is for looking up port
642 * open requests from the server), a tree of _these_ structures is
643 * used to keep track of all the currently open port forwardings,
644 * so that we can reconfigure in mid-session if the user requests
648 enum { DESTROY, KEEP, CREATE } status;
650 unsigned sport, dport;
653 struct ssh_rportfwd *remote;
655 struct PortListener *local;
657 #define free_portfwd(pf) ( \
658 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
659 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
662 long length; /* length of packet: see below */
663 long forcepad; /* SSH-2: force padding to at least this length */
664 int type; /* only used for incoming packets */
665 unsigned long sequence; /* SSH-2 incoming sequence number */
666 unsigned char *data; /* allocated storage */
667 unsigned char *body; /* offset of payload within `data' */
668 long savedpos; /* dual-purpose saved packet position: see below */
669 long maxlen; /* amount of storage allocated for `data' */
670 long encrypted_len; /* for SSH-2 total-size counting */
673 * A note on the 'length' and 'savedpos' fields above.
675 * Incoming packets are set up so that pkt->length is measured
676 * relative to pkt->body, which itself points to a few bytes after
677 * pkt->data (skipping some uninteresting header fields including
678 * the packet type code). The ssh_pkt_get* functions all expect
679 * this setup, and they also use pkt->savedpos to indicate how far
680 * through the packet being decoded they've got - and that, too,
681 * is an offset from pkt->body rather than pkt->data.
683 * During construction of an outgoing packet, however, pkt->length
684 * is measured relative to the base pointer pkt->data, and
685 * pkt->body is not really used for anything until the packet is
686 * ready for sending. In this mode, pkt->savedpos is reused as a
687 * temporary variable by the addstring functions, which write out
688 * a string length field and then keep going back and updating it
689 * as more data is appended to the subsequent string data field;
690 * pkt->savedpos stores the offset (again relative to pkt->data)
691 * of the start of the string data field.
694 /* Extra metadata used in SSH packet logging mode, allowing us to
695 * log in the packet header line that the packet came from a
696 * connection-sharing downstream and what if anything unusual was
697 * done to it. The additional_log_text field is expected to be a
698 * static string - it will not be freed. */
699 unsigned downstream_id;
700 const char *additional_log_text;
703 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
704 struct Packet *pktin);
705 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
706 struct Packet *pktin);
707 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
708 struct Packet *pktin);
709 static void ssh1_protocol_setup(Ssh ssh);
710 static void ssh2_protocol_setup(Ssh ssh);
711 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
712 static void ssh_size(void *handle, int width, int height);
713 static void ssh_special(void *handle, Telnet_Special);
714 static int ssh2_try_send(struct ssh_channel *c);
715 static int ssh_send_channel_data(struct ssh_channel *c,
716 const char *buf, int len);
717 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
718 static void ssh2_set_window(struct ssh_channel *c, int newwin);
719 static int ssh_sendbuffer(void *handle);
720 static int ssh_do_close(Ssh ssh, int notify_exit);
721 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
722 static int ssh2_pkt_getbool(struct Packet *pkt);
723 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
724 static void ssh2_timer(void *ctx, unsigned long now);
725 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
726 struct Packet *pktin);
727 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
729 struct rdpkt1_state_tag {
730 long len, pad, biglen, to_read;
731 unsigned long realcrc, gotcrc;
735 struct Packet *pktin;
738 struct rdpkt2_state_tag {
739 long len, pad, payload, packetlen, maclen;
742 unsigned long incoming_sequence;
743 struct Packet *pktin;
746 struct rdpkt2_bare_state_tag {
750 unsigned long incoming_sequence;
751 struct Packet *pktin;
754 struct queued_handler;
755 struct queued_handler {
757 chandler_fn_t handler;
759 struct queued_handler *next;
763 const struct plug_function_table *fn;
764 /* the above field _must_ be first in the structure */
774 unsigned char session_key[32];
776 int v1_remote_protoflags;
777 int v1_local_protoflags;
778 int agentfwd_enabled;
781 const struct ssh_cipher *cipher;
784 const struct ssh2_cipher *cscipher, *sccipher;
785 void *cs_cipher_ctx, *sc_cipher_ctx;
786 const struct ssh_mac *csmac, *scmac;
787 int csmac_etm, scmac_etm;
788 void *cs_mac_ctx, *sc_mac_ctx;
789 const struct ssh_compress *cscomp, *sccomp;
790 void *cs_comp_ctx, *sc_comp_ctx;
791 const struct ssh_kex *kex;
792 const struct ssh_signkey *hostkey;
793 char *hostkey_str; /* string representation, for easy checking in rekeys */
794 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
795 int v2_session_id_len;
799 int attempting_connshare;
805 int echoing, editing;
810 int ospeed, ispeed; /* temporaries */
811 int term_width, term_height;
813 tree234 *channels; /* indexed by local id */
814 struct ssh_channel *mainchan; /* primary session channel */
815 int ncmode; /* is primary channel direct-tcpip? */
820 tree234 *rportfwds, *portfwds;
824 SSH_STATE_BEFORE_SIZE,
830 int size_needed, eof_needed;
831 int sent_console_eof;
832 int got_pty; /* affects EOF behaviour on main channel */
834 struct Packet **queue;
835 int queuelen, queuesize;
837 unsigned char *deferred_send_data;
838 int deferred_len, deferred_size;
841 * Gross hack: pscp will try to start SFTP but fall back to
842 * scp1 if that fails. This variable is the means by which
843 * scp.c can reach into the SSH code and find out which one it
848 bufchain banner; /* accumulates banners during do_ssh2_authconn */
853 struct X11Display *x11disp;
854 struct X11FakeAuth *x11auth;
855 tree234 *x11authtree;
858 int conn_throttle_count;
861 int v1_stdout_throttling;
862 unsigned long v2_outgoing_sequence;
864 int ssh1_rdpkt_crstate;
865 int ssh2_rdpkt_crstate;
866 int ssh2_bare_rdpkt_crstate;
867 int ssh_gotdata_crstate;
868 int do_ssh1_connection_crstate;
870 void *do_ssh_init_state;
871 void *do_ssh1_login_state;
872 void *do_ssh2_transport_state;
873 void *do_ssh2_authconn_state;
874 void *do_ssh_connection_init_state;
876 struct rdpkt1_state_tag rdpkt1_state;
877 struct rdpkt2_state_tag rdpkt2_state;
878 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
880 /* SSH-1 and SSH-2 use this for different things, but both use it */
881 int protocol_initial_phase_done;
883 void (*protocol) (Ssh ssh, const void *vin, int inlen,
885 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
887 int (*do_ssh_init)(Ssh ssh, unsigned char c);
890 * We maintain our own copy of a Conf structure here. That way,
891 * when we're passed a new one for reconfiguration, we can check
892 * the differences and potentially reconfigure port forwardings
893 * etc in mid-session.
898 * Values cached out of conf so as to avoid the tree234 lookup
899 * cost every time they're used.
904 * Dynamically allocated username string created during SSH
905 * login. Stored in here rather than in the coroutine state so
906 * that it'll be reliably freed if we shut down the SSH session
907 * at some unexpected moment.
912 * Used to transfer data back from async callbacks.
914 void *agent_response;
915 int agent_response_len;
919 * The SSH connection can be set as `frozen', meaning we are
920 * not currently accepting incoming data from the network. This
921 * is slightly more serious than setting the _socket_ as
922 * frozen, because we may already have had data passed to us
923 * from the network which we need to delay processing until
924 * after the freeze is lifted, so we also need a bufchain to
928 bufchain queued_incoming_data;
931 * Dispatch table for packet types that we may have to deal
934 handler_fn_t packet_dispatch[256];
937 * Queues of one-off handler functions for success/failure
938 * indications from a request.
940 struct queued_handler *qhead, *qtail;
941 handler_fn_t q_saved_handler1, q_saved_handler2;
944 * This module deals with sending keepalives.
949 * Track incoming and outgoing data sizes and time, for
952 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
953 unsigned long max_data_size;
955 unsigned long next_rekey, last_rekey;
956 const char *deferred_rekey_reason;
959 * Fully qualified host name, which we need if doing GSSAPI.
965 * GSSAPI libraries for this session.
967 struct ssh_gss_liblist *gsslibs;
971 * The last list returned from get_specials.
973 struct telnet_special *specials;
976 * List of host key algorithms for which we _don't_ have a stored
977 * host key. These are indices into the main hostkey_algs[] array
979 int uncert_hostkeys[lenof(hostkey_algs)];
980 int n_uncert_hostkeys;
983 * Flag indicating that the current rekey is intended to finish
984 * with a newly cross-certified host key.
986 int cross_certifying;
989 static const char *ssh_pkt_type(Ssh ssh, int type)
991 if (ssh->version == 1)
992 return ssh1_pkt_type(type);
994 return ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, type);
997 #define logevent(s) logevent(ssh->frontend, s)
999 /* logevent, only printf-formatted. */
1000 static void logeventf(Ssh ssh, const char *fmt, ...)
1006 buf = dupvprintf(fmt, ap);
1012 static void bomb_out(Ssh ssh, char *text)
1014 ssh_do_close(ssh, FALSE);
1016 connection_fatal(ssh->frontend, "%s", text);
1020 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1022 /* Helper function for common bits of parsing ttymodes. */
1023 static void parse_ttymodes(Ssh ssh,
1024 void (*do_mode)(void *data,
1025 const struct ssh_ttymode *mode,
1030 const struct ssh_ttymode *mode;
1032 char default_val[2];
1034 strcpy(default_val, "A");
1036 for (i = 0; i < lenof(ssh_ttymodes); i++) {
1037 mode = ssh_ttymodes + i;
1038 val = conf_get_str_str_opt(ssh->conf, CONF_ttymodes, mode->mode);
1043 * val[0] is either 'V', indicating that an explicit value
1044 * follows it, or 'A' indicating that we should pass the
1045 * value through from the local environment via get_ttymode.
1047 if (val[0] == 'A') {
1048 val = get_ttymode(ssh->frontend, mode->mode);
1050 do_mode(data, mode, val);
1054 do_mode(data, mode, val + 1); /* skip the 'V' */
1058 static int ssh_channelcmp(void *av, void *bv)
1060 struct ssh_channel *a = (struct ssh_channel *) av;
1061 struct ssh_channel *b = (struct ssh_channel *) bv;
1062 if (a->localid < b->localid)
1064 if (a->localid > b->localid)
1068 static int ssh_channelfind(void *av, void *bv)
1070 unsigned *a = (unsigned *) av;
1071 struct ssh_channel *b = (struct ssh_channel *) bv;
1072 if (*a < b->localid)
1074 if (*a > b->localid)
1079 static int ssh_rportcmp_ssh1(void *av, void *bv)
1081 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1082 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1084 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1085 return i < 0 ? -1 : +1;
1086 if (a->dport > b->dport)
1088 if (a->dport < b->dport)
1093 static int ssh_rportcmp_ssh2(void *av, void *bv)
1095 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1096 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1098 if ( (i = strcmp(a->shost, b->shost)) != 0)
1099 return i < 0 ? -1 : +1;
1100 if (a->sport > b->sport)
1102 if (a->sport < b->sport)
1108 * Special form of strcmp which can cope with NULL inputs. NULL is
1109 * defined to sort before even the empty string.
1111 static int nullstrcmp(const char *a, const char *b)
1113 if (a == NULL && b == NULL)
1119 return strcmp(a, b);
1122 static int ssh_portcmp(void *av, void *bv)
1124 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1125 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1127 if (a->type > b->type)
1129 if (a->type < b->type)
1131 if (a->addressfamily > b->addressfamily)
1133 if (a->addressfamily < b->addressfamily)
1135 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1136 return i < 0 ? -1 : +1;
1137 if (a->sport > b->sport)
1139 if (a->sport < b->sport)
1141 if (a->type != 'D') {
1142 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1143 return i < 0 ? -1 : +1;
1144 if (a->dport > b->dport)
1146 if (a->dport < b->dport)
1152 static int alloc_channel_id(Ssh ssh)
1154 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1155 unsigned low, high, mid;
1157 struct ssh_channel *c;
1160 * First-fit allocation of channel numbers: always pick the
1161 * lowest unused one. To do this, binary-search using the
1162 * counted B-tree to find the largest channel ID which is in a
1163 * contiguous sequence from the beginning. (Precisely
1164 * everything in that sequence must have ID equal to its tree
1165 * index plus CHANNEL_NUMBER_OFFSET.)
1167 tsize = count234(ssh->channels);
1171 while (high - low > 1) {
1172 mid = (high + low) / 2;
1173 c = index234(ssh->channels, mid);
1174 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1175 low = mid; /* this one is fine */
1177 high = mid; /* this one is past it */
1180 * Now low points to either -1, or the tree index of the
1181 * largest ID in the initial sequence.
1184 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1185 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1187 return low + 1 + CHANNEL_NUMBER_OFFSET;
1190 static void c_write_stderr(int trusted, const char *buf, int len)
1193 for (i = 0; i < len; i++)
1194 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1195 fputc(buf[i], stderr);
1198 static void c_write(Ssh ssh, const char *buf, int len)
1200 if (flags & FLAG_STDERR)
1201 c_write_stderr(1, buf, len);
1203 from_backend(ssh->frontend, 1, buf, len);
1206 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1208 if (flags & FLAG_STDERR)
1209 c_write_stderr(0, buf, len);
1211 from_backend_untrusted(ssh->frontend, buf, len);
1214 static void c_write_str(Ssh ssh, const char *buf)
1216 c_write(ssh, buf, strlen(buf));
1219 static void ssh_free_packet(struct Packet *pkt)
1224 static struct Packet *ssh_new_packet(void)
1226 struct Packet *pkt = snew(struct Packet);
1228 pkt->body = pkt->data = NULL;
1234 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1237 struct logblank_t blanks[4];
1243 if (ssh->logomitdata &&
1244 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1245 pkt->type == SSH1_SMSG_STDERR_DATA ||
1246 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1247 /* "Session data" packets - omit the data string. */
1248 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1249 ssh_pkt_getuint32(pkt); /* skip channel id */
1250 blanks[nblanks].offset = pkt->savedpos + 4;
1251 blanks[nblanks].type = PKTLOG_OMIT;
1252 ssh_pkt_getstring(pkt, &str, &slen);
1254 blanks[nblanks].len = slen;
1258 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1259 ssh1_pkt_type(pkt->type),
1260 pkt->body, pkt->length, nblanks, blanks, NULL,
1264 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1267 struct logblank_t blanks[4];
1272 * For outgoing packets, pkt->length represents the length of the
1273 * whole packet starting at pkt->data (including some header), and
1274 * pkt->body refers to the point within that where the log-worthy
1275 * payload begins. However, incoming packets expect pkt->length to
1276 * represent only the payload length (that is, it's measured from
1277 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1278 * packet to conform to the incoming-packet semantics, so that we
1279 * can analyse it with the ssh_pkt_get functions.
1281 pkt->length -= (pkt->body - pkt->data);
1284 if (ssh->logomitdata &&
1285 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1286 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1287 /* "Session data" packets - omit the data string. */
1288 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1289 ssh_pkt_getuint32(pkt); /* skip channel id */
1290 blanks[nblanks].offset = pkt->savedpos + 4;
1291 blanks[nblanks].type = PKTLOG_OMIT;
1292 ssh_pkt_getstring(pkt, &str, &slen);
1294 blanks[nblanks].len = slen;
1299 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1300 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1301 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1302 conf_get_int(ssh->conf, CONF_logomitpass)) {
1303 /* If this is a password or similar packet, blank the password(s). */
1304 blanks[nblanks].offset = 0;
1305 blanks[nblanks].len = pkt->length;
1306 blanks[nblanks].type = PKTLOG_BLANK;
1308 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1309 conf_get_int(ssh->conf, CONF_logomitpass)) {
1311 * If this is an X forwarding request packet, blank the fake
1314 * Note that while we blank the X authentication data here, we
1315 * don't take any special action to blank the start of an X11
1316 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1317 * an X connection without having session blanking enabled is
1318 * likely to leak your cookie into the log.
1321 ssh_pkt_getstring(pkt, &str, &slen);
1322 blanks[nblanks].offset = pkt->savedpos;
1323 blanks[nblanks].type = PKTLOG_BLANK;
1324 ssh_pkt_getstring(pkt, &str, &slen);
1326 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1331 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1332 ssh1_pkt_type(pkt->data[12]),
1333 pkt->body, pkt->length,
1334 nblanks, blanks, NULL, 0, NULL);
1337 * Undo the above adjustment of pkt->length, to put the packet
1338 * back in the state we found it.
1340 pkt->length += (pkt->body - pkt->data);
1344 * Collect incoming data in the incoming packet buffer.
1345 * Decipher and verify the packet when it is completely read.
1346 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1347 * Update the *data and *datalen variables.
1348 * Return a Packet structure when a packet is completed.
1350 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1353 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1355 crBegin(ssh->ssh1_rdpkt_crstate);
1357 st->pktin = ssh_new_packet();
1359 st->pktin->type = 0;
1360 st->pktin->length = 0;
1362 for (st->i = st->len = 0; st->i < 4; st->i++) {
1363 while ((*datalen) == 0)
1365 st->len = (st->len << 8) + **data;
1366 (*data)++, (*datalen)--;
1369 st->pad = 8 - (st->len % 8);
1370 st->biglen = st->len + st->pad;
1371 st->pktin->length = st->len - 5;
1373 if (st->biglen < 0) {
1374 bombout(("Extremely large packet length from server suggests"
1375 " data stream corruption"));
1376 ssh_free_packet(st->pktin);
1380 st->pktin->maxlen = st->biglen;
1381 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1383 st->to_read = st->biglen;
1384 st->p = st->pktin->data;
1385 while (st->to_read > 0) {
1386 st->chunk = st->to_read;
1387 while ((*datalen) == 0)
1389 if (st->chunk > (*datalen))
1390 st->chunk = (*datalen);
1391 memcpy(st->p, *data, st->chunk);
1393 *datalen -= st->chunk;
1395 st->to_read -= st->chunk;
1398 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1399 st->biglen, NULL)) {
1400 bombout(("Network attack (CRC compensation) detected!"));
1401 ssh_free_packet(st->pktin);
1406 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1408 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1409 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1410 if (st->gotcrc != st->realcrc) {
1411 bombout(("Incorrect CRC received on packet"));
1412 ssh_free_packet(st->pktin);
1416 st->pktin->body = st->pktin->data + st->pad + 1;
1418 if (ssh->v1_compressing) {
1419 unsigned char *decompblk;
1421 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1422 st->pktin->body - 1, st->pktin->length + 1,
1423 &decompblk, &decomplen)) {
1424 bombout(("Zlib decompression encountered invalid data"));
1425 ssh_free_packet(st->pktin);
1429 if (st->pktin->maxlen < st->pad + decomplen) {
1430 st->pktin->maxlen = st->pad + decomplen;
1431 st->pktin->data = sresize(st->pktin->data,
1432 st->pktin->maxlen + APIEXTRA,
1434 st->pktin->body = st->pktin->data + st->pad + 1;
1437 memcpy(st->pktin->body - 1, decompblk, decomplen);
1439 st->pktin->length = decomplen - 1;
1442 st->pktin->type = st->pktin->body[-1];
1445 * Now pktin->body and pktin->length identify the semantic content
1446 * of the packet, excluding the initial type byte.
1450 ssh1_log_incoming_packet(ssh, st->pktin);
1452 st->pktin->savedpos = 0;
1454 crFinish(st->pktin);
1457 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1460 struct logblank_t blanks[4];
1466 if (ssh->logomitdata &&
1467 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1468 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1469 /* "Session data" packets - omit the data string. */
1470 ssh_pkt_getuint32(pkt); /* skip channel id */
1471 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1472 ssh_pkt_getuint32(pkt); /* skip extended data type */
1473 blanks[nblanks].offset = pkt->savedpos + 4;
1474 blanks[nblanks].type = PKTLOG_OMIT;
1475 ssh_pkt_getstring(pkt, &str, &slen);
1477 blanks[nblanks].len = slen;
1482 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1483 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1484 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1488 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1491 struct logblank_t blanks[4];
1496 * For outgoing packets, pkt->length represents the length of the
1497 * whole packet starting at pkt->data (including some header), and
1498 * pkt->body refers to the point within that where the log-worthy
1499 * payload begins. However, incoming packets expect pkt->length to
1500 * represent only the payload length (that is, it's measured from
1501 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1502 * packet to conform to the incoming-packet semantics, so that we
1503 * can analyse it with the ssh_pkt_get functions.
1505 pkt->length -= (pkt->body - pkt->data);
1508 if (ssh->logomitdata &&
1509 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1510 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1511 /* "Session data" packets - omit the data string. */
1512 ssh_pkt_getuint32(pkt); /* skip channel id */
1513 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1514 ssh_pkt_getuint32(pkt); /* skip extended data type */
1515 blanks[nblanks].offset = pkt->savedpos + 4;
1516 blanks[nblanks].type = PKTLOG_OMIT;
1517 ssh_pkt_getstring(pkt, &str, &slen);
1519 blanks[nblanks].len = slen;
1524 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1525 conf_get_int(ssh->conf, CONF_logomitpass)) {
1526 /* If this is a password packet, blank the password(s). */
1528 ssh_pkt_getstring(pkt, &str, &slen);
1529 ssh_pkt_getstring(pkt, &str, &slen);
1530 ssh_pkt_getstring(pkt, &str, &slen);
1531 if (slen == 8 && !memcmp(str, "password", 8)) {
1532 ssh2_pkt_getbool(pkt);
1533 /* Blank the password field. */
1534 blanks[nblanks].offset = pkt->savedpos;
1535 blanks[nblanks].type = PKTLOG_BLANK;
1536 ssh_pkt_getstring(pkt, &str, &slen);
1538 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1540 /* If there's another password field beyond it (change of
1541 * password), blank that too. */
1542 ssh_pkt_getstring(pkt, &str, &slen);
1544 blanks[nblanks-1].len =
1545 pkt->savedpos - blanks[nblanks].offset;
1548 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1549 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1550 conf_get_int(ssh->conf, CONF_logomitpass)) {
1551 /* If this is a keyboard-interactive response packet, blank
1554 ssh_pkt_getuint32(pkt);
1555 blanks[nblanks].offset = pkt->savedpos;
1556 blanks[nblanks].type = PKTLOG_BLANK;
1558 ssh_pkt_getstring(pkt, &str, &slen);
1562 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1564 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1565 conf_get_int(ssh->conf, CONF_logomitpass)) {
1567 * If this is an X forwarding request packet, blank the fake
1570 * Note that while we blank the X authentication data here, we
1571 * don't take any special action to blank the start of an X11
1572 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1573 * an X connection without having session blanking enabled is
1574 * likely to leak your cookie into the log.
1577 ssh_pkt_getuint32(pkt);
1578 ssh_pkt_getstring(pkt, &str, &slen);
1579 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1580 ssh2_pkt_getbool(pkt);
1581 ssh2_pkt_getbool(pkt);
1582 ssh_pkt_getstring(pkt, &str, &slen);
1583 blanks[nblanks].offset = pkt->savedpos;
1584 blanks[nblanks].type = PKTLOG_BLANK;
1585 ssh_pkt_getstring(pkt, &str, &slen);
1587 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1593 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1594 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1595 pkt->body, pkt->length, nblanks, blanks,
1596 &ssh->v2_outgoing_sequence,
1597 pkt->downstream_id, pkt->additional_log_text);
1600 * Undo the above adjustment of pkt->length, to put the packet
1601 * back in the state we found it.
1603 pkt->length += (pkt->body - pkt->data);
1606 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1609 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1611 crBegin(ssh->ssh2_rdpkt_crstate);
1613 st->pktin = ssh_new_packet();
1615 st->pktin->type = 0;
1616 st->pktin->length = 0;
1618 st->cipherblk = ssh->sccipher->blksize;
1621 if (st->cipherblk < 8)
1623 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1625 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1626 ssh->scmac && !ssh->scmac_etm) {
1628 * When dealing with a CBC-mode cipher, we want to avoid the
1629 * possibility of an attacker's tweaking the ciphertext stream
1630 * so as to cause us to feed the same block to the block
1631 * cipher more than once and thus leak information
1632 * (VU#958563). The way we do this is not to take any
1633 * decisions on the basis of anything we've decrypted until
1634 * we've verified it with a MAC. That includes the packet
1635 * length, so we just read data and check the MAC repeatedly,
1636 * and when the MAC passes, see if the length we've got is
1639 * This defence is unnecessary in OpenSSH ETM mode, because
1640 * the whole point of ETM mode is that the attacker can't
1641 * tweak the ciphertext stream at all without the MAC
1642 * detecting it before we decrypt anything.
1645 /* May as well allocate the whole lot now. */
1646 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1649 /* Read an amount corresponding to the MAC. */
1650 for (st->i = 0; st->i < st->maclen; st->i++) {
1651 while ((*datalen) == 0)
1653 st->pktin->data[st->i] = *(*data)++;
1659 unsigned char seq[4];
1660 ssh->scmac->start(ssh->sc_mac_ctx);
1661 PUT_32BIT(seq, st->incoming_sequence);
1662 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1665 for (;;) { /* Once around this loop per cipher block. */
1666 /* Read another cipher-block's worth, and tack it onto the end. */
1667 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1668 while ((*datalen) == 0)
1670 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1673 /* Decrypt one more block (a little further back in the stream). */
1674 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1675 st->pktin->data + st->packetlen,
1677 /* Feed that block to the MAC. */
1678 ssh->scmac->bytes(ssh->sc_mac_ctx,
1679 st->pktin->data + st->packetlen, st->cipherblk);
1680 st->packetlen += st->cipherblk;
1681 /* See if that gives us a valid packet. */
1682 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1683 st->pktin->data + st->packetlen) &&
1684 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1687 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1688 bombout(("No valid incoming packet found"));
1689 ssh_free_packet(st->pktin);
1693 st->pktin->maxlen = st->packetlen + st->maclen;
1694 st->pktin->data = sresize(st->pktin->data,
1695 st->pktin->maxlen + APIEXTRA,
1697 } else if (ssh->scmac && ssh->scmac_etm) {
1698 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1701 * OpenSSH encrypt-then-MAC mode: the packet length is
1702 * unencrypted, unless the cipher supports length encryption.
1704 for (st->i = st->len = 0; st->i < 4; st->i++) {
1705 while ((*datalen) == 0)
1707 st->pktin->data[st->i] = *(*data)++;
1710 /* Cipher supports length decryption, so do it */
1711 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1712 /* Keep the packet the same though, so the MAC passes */
1713 unsigned char len[4];
1714 memcpy(len, st->pktin->data, 4);
1715 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1716 st->len = toint(GET_32BIT(len));
1718 st->len = toint(GET_32BIT(st->pktin->data));
1722 * _Completely_ silly lengths should be stomped on before they
1723 * do us any more damage.
1725 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1726 st->len % st->cipherblk != 0) {
1727 bombout(("Incoming packet length field was garbled"));
1728 ssh_free_packet(st->pktin);
1733 * So now we can work out the total packet length.
1735 st->packetlen = st->len + 4;
1738 * Allocate memory for the rest of the packet.
1740 st->pktin->maxlen = st->packetlen + st->maclen;
1741 st->pktin->data = sresize(st->pktin->data,
1742 st->pktin->maxlen + APIEXTRA,
1746 * Read the remainder of the packet.
1748 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1749 while ((*datalen) == 0)
1751 st->pktin->data[st->i] = *(*data)++;
1759 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1760 st->len + 4, st->incoming_sequence)) {
1761 bombout(("Incorrect MAC received on packet"));
1762 ssh_free_packet(st->pktin);
1766 /* Decrypt everything between the length field and the MAC. */
1768 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1769 st->pktin->data + 4,
1772 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1775 * Acquire and decrypt the first block of the packet. This will
1776 * contain the length and padding details.
1778 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1779 while ((*datalen) == 0)
1781 st->pktin->data[st->i] = *(*data)++;
1786 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1787 st->pktin->data, st->cipherblk);
1790 * Now get the length figure.
1792 st->len = toint(GET_32BIT(st->pktin->data));
1795 * _Completely_ silly lengths should be stomped on before they
1796 * do us any more damage.
1798 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1799 (st->len + 4) % st->cipherblk != 0) {
1800 bombout(("Incoming packet was garbled on decryption"));
1801 ssh_free_packet(st->pktin);
1806 * So now we can work out the total packet length.
1808 st->packetlen = st->len + 4;
1811 * Allocate memory for the rest of the packet.
1813 st->pktin->maxlen = st->packetlen + st->maclen;
1814 st->pktin->data = sresize(st->pktin->data,
1815 st->pktin->maxlen + APIEXTRA,
1819 * Read and decrypt the remainder of the packet.
1821 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1823 while ((*datalen) == 0)
1825 st->pktin->data[st->i] = *(*data)++;
1828 /* Decrypt everything _except_ the MAC. */
1830 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1831 st->pktin->data + st->cipherblk,
1832 st->packetlen - st->cipherblk);
1838 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1839 st->len + 4, st->incoming_sequence)) {
1840 bombout(("Incorrect MAC received on packet"));
1841 ssh_free_packet(st->pktin);
1845 /* Get and sanity-check the amount of random padding. */
1846 st->pad = st->pktin->data[4];
1847 if (st->pad < 4 || st->len - st->pad < 1) {
1848 bombout(("Invalid padding length on received packet"));
1849 ssh_free_packet(st->pktin);
1853 * This enables us to deduce the payload length.
1855 st->payload = st->len - st->pad - 1;
1857 st->pktin->length = st->payload + 5;
1858 st->pktin->encrypted_len = st->packetlen;
1860 st->pktin->sequence = st->incoming_sequence++;
1862 st->pktin->length = st->packetlen - st->pad;
1863 assert(st->pktin->length >= 0);
1866 * Decompress packet payload.
1869 unsigned char *newpayload;
1872 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1873 st->pktin->data + 5, st->pktin->length - 5,
1874 &newpayload, &newlen)) {
1875 if (st->pktin->maxlen < newlen + 5) {
1876 st->pktin->maxlen = newlen + 5;
1877 st->pktin->data = sresize(st->pktin->data,
1878 st->pktin->maxlen + APIEXTRA,
1881 st->pktin->length = 5 + newlen;
1882 memcpy(st->pktin->data + 5, newpayload, newlen);
1888 * RFC 4253 doesn't explicitly say that completely empty packets
1889 * with no type byte are forbidden, so treat them as deserving
1890 * an SSH_MSG_UNIMPLEMENTED.
1892 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1893 ssh2_msg_something_unimplemented(ssh, st->pktin);
1897 * pktin->body and pktin->length should identify the semantic
1898 * content of the packet, excluding the initial type byte.
1900 st->pktin->type = st->pktin->data[5];
1901 st->pktin->body = st->pktin->data + 6;
1902 st->pktin->length -= 6;
1903 assert(st->pktin->length >= 0); /* one last double-check */
1906 ssh2_log_incoming_packet(ssh, st->pktin);
1908 st->pktin->savedpos = 0;
1910 crFinish(st->pktin);
1913 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1914 const unsigned char **data,
1917 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1919 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1922 * Read the packet length field.
1924 for (st->i = 0; st->i < 4; st->i++) {
1925 while ((*datalen) == 0)
1927 st->length[st->i] = *(*data)++;
1931 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1932 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1933 bombout(("Invalid packet length received"));
1937 st->pktin = ssh_new_packet();
1938 st->pktin->data = snewn(st->packetlen, unsigned char);
1940 st->pktin->encrypted_len = st->packetlen;
1942 st->pktin->sequence = st->incoming_sequence++;
1945 * Read the remainder of the packet.
1947 for (st->i = 0; st->i < st->packetlen; st->i++) {
1948 while ((*datalen) == 0)
1950 st->pktin->data[st->i] = *(*data)++;
1955 * pktin->body and pktin->length should identify the semantic
1956 * content of the packet, excluding the initial type byte.
1958 st->pktin->type = st->pktin->data[0];
1959 st->pktin->body = st->pktin->data + 1;
1960 st->pktin->length = st->packetlen - 1;
1963 * Log incoming packet, possibly omitting sensitive fields.
1966 ssh2_log_incoming_packet(ssh, st->pktin);
1968 st->pktin->savedpos = 0;
1970 crFinish(st->pktin);
1973 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1975 int pad, biglen, i, pktoffs;
1979 * XXX various versions of SC (including 8.8.4) screw up the
1980 * register allocation in this function and use the same register
1981 * (D6) for len and as a temporary, with predictable results. The
1982 * following sledgehammer prevents this.
1989 ssh1_log_outgoing_packet(ssh, pkt);
1991 if (ssh->v1_compressing) {
1992 unsigned char *compblk;
1994 zlib_compress_block(ssh->cs_comp_ctx,
1995 pkt->data + 12, pkt->length - 12,
1996 &compblk, &complen);
1997 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1998 memcpy(pkt->data + 12, compblk, complen);
2000 pkt->length = complen + 12;
2003 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
2005 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
2006 pad = 8 - (len % 8);
2008 biglen = len + pad; /* len(padding+type+data+CRC) */
2010 for (i = pktoffs; i < 4+8; i++)
2011 pkt->data[i] = random_byte();
2012 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
2013 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
2014 PUT_32BIT(pkt->data + pktoffs, len);
2017 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
2018 pkt->data + pktoffs + 4, biglen);
2020 if (offset_p) *offset_p = pktoffs;
2021 return biglen + 4; /* len(length+padding+type+data+CRC) */
2024 static int s_write(Ssh ssh, void *data, int len)
2027 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
2028 0, NULL, NULL, 0, NULL);
2031 return sk_write(ssh->s, (char *)data, len);
2034 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2036 int len, backlog, offset;
2037 len = s_wrpkt_prepare(ssh, pkt, &offset);
2038 backlog = s_write(ssh, pkt->data + offset, len);
2039 if (backlog > SSH_MAX_BACKLOG)
2040 ssh_throttle_all(ssh, 1, backlog);
2041 ssh_free_packet(pkt);
2044 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2047 len = s_wrpkt_prepare(ssh, pkt, &offset);
2048 if (ssh->deferred_len + len > ssh->deferred_size) {
2049 ssh->deferred_size = ssh->deferred_len + len + 128;
2050 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2054 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2055 pkt->data + offset, len);
2056 ssh->deferred_len += len;
2057 ssh_free_packet(pkt);
2061 * Construct a SSH-1 packet with the specified contents.
2062 * (This all-at-once interface used to be the only one, but now SSH-1
2063 * packets can also be constructed incrementally.)
2065 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2071 pkt = ssh1_pkt_init(pkttype);
2073 while ((argtype = va_arg(ap, int)) != PKT_END) {
2074 unsigned char *argp, argchar;
2076 unsigned long argint;
2079 /* Actual fields in the packet */
2081 argint = va_arg(ap, int);
2082 ssh_pkt_adduint32(pkt, argint);
2085 argchar = (unsigned char) va_arg(ap, int);
2086 ssh_pkt_addbyte(pkt, argchar);
2089 argp = va_arg(ap, unsigned char *);
2090 arglen = va_arg(ap, int);
2091 ssh_pkt_adddata(pkt, argp, arglen);
2094 sargp = va_arg(ap, char *);
2095 ssh_pkt_addstring(pkt, sargp);
2098 bn = va_arg(ap, Bignum);
2099 ssh1_pkt_addmp(pkt, bn);
2107 static void send_packet(Ssh ssh, int pkttype, ...)
2111 va_start(ap, pkttype);
2112 pkt = construct_packet(ssh, pkttype, ap);
2117 static void defer_packet(Ssh ssh, int pkttype, ...)
2121 va_start(ap, pkttype);
2122 pkt = construct_packet(ssh, pkttype, ap);
2124 s_wrpkt_defer(ssh, pkt);
2127 static int ssh_versioncmp(const char *a, const char *b)
2130 unsigned long av, bv;
2132 av = strtoul(a, &ae, 10);
2133 bv = strtoul(b, &be, 10);
2135 return (av < bv ? -1 : +1);
2140 av = strtoul(ae, &ae, 10);
2141 bv = strtoul(be, &be, 10);
2143 return (av < bv ? -1 : +1);
2148 * Utility routines for putting an SSH-protocol `string' and
2149 * `uint32' into a hash state.
2151 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2153 unsigned char lenblk[4];
2154 PUT_32BIT(lenblk, len);
2155 h->bytes(s, lenblk, 4);
2156 h->bytes(s, str, len);
2159 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2161 unsigned char intblk[4];
2162 PUT_32BIT(intblk, i);
2163 h->bytes(s, intblk, 4);
2167 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2169 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2171 if (pkt->maxlen < length) {
2172 unsigned char *body = pkt->body;
2173 int offset = body ? body - pkt->data : 0;
2174 pkt->maxlen = length + 256;
2175 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2176 if (body) pkt->body = pkt->data + offset;
2179 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2182 ssh_pkt_ensure(pkt, pkt->length);
2183 memcpy(pkt->data + pkt->length - len, data, len);
2185 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2187 ssh_pkt_adddata(pkt, &byte, 1);
2189 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2191 ssh_pkt_adddata(pkt, &value, 1);
2193 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2196 PUT_32BIT(x, value);
2197 ssh_pkt_adddata(pkt, x, 4);
2199 static void ssh_pkt_addstring_start(struct Packet *pkt)
2201 ssh_pkt_adduint32(pkt, 0);
2202 pkt->savedpos = pkt->length;
2204 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2207 ssh_pkt_adddata(pkt, data, len);
2208 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2210 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2212 ssh_pkt_addstring_data(pkt, data, strlen(data));
2214 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2216 ssh_pkt_addstring_start(pkt);
2217 ssh_pkt_addstring_str(pkt, data);
2219 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2221 int len = ssh1_bignum_length(b);
2222 unsigned char *data = snewn(len, unsigned char);
2223 (void) ssh1_write_bignum(data, b);
2224 ssh_pkt_adddata(pkt, data, len);
2227 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2230 int i, n = (bignum_bitcount(b) + 7) / 8;
2231 p = snewn(n + 1, unsigned char);
2233 for (i = 1; i <= n; i++)
2234 p[i] = bignum_byte(b, n - i);
2236 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2238 memmove(p, p + i, n + 1 - i);
2242 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2246 p = ssh2_mpint_fmt(b, &len);
2247 ssh_pkt_addstring_start(pkt);
2248 ssh_pkt_addstring_data(pkt, (char *)p, len);
2252 static struct Packet *ssh1_pkt_init(int pkt_type)
2254 struct Packet *pkt = ssh_new_packet();
2255 pkt->length = 4 + 8; /* space for length + max padding */
2256 ssh_pkt_addbyte(pkt, pkt_type);
2257 pkt->body = pkt->data + pkt->length;
2258 pkt->type = pkt_type;
2259 pkt->downstream_id = 0;
2260 pkt->additional_log_text = NULL;
2264 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2265 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2266 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2267 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2268 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2269 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2270 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2271 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2272 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2274 static struct Packet *ssh2_pkt_init(int pkt_type)
2276 struct Packet *pkt = ssh_new_packet();
2277 pkt->length = 5; /* space for packet length + padding length */
2279 pkt->type = pkt_type;
2280 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2281 pkt->body = pkt->data + pkt->length; /* after packet type */
2282 pkt->downstream_id = 0;
2283 pkt->additional_log_text = NULL;
2288 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2289 * put the MAC on it. Final packet, ready to be sent, is stored in
2290 * pkt->data. Total length is returned.
2292 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2294 int cipherblk, maclen, padding, unencrypted_prefix, i;
2297 ssh2_log_outgoing_packet(ssh, pkt);
2299 if (ssh->bare_connection) {
2301 * Trivial packet construction for the bare connection
2304 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2305 pkt->body = pkt->data + 1;
2306 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2307 return pkt->length - 1;
2311 * Compress packet payload.
2314 unsigned char *newpayload;
2317 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2319 &newpayload, &newlen)) {
2321 ssh2_pkt_adddata(pkt, newpayload, newlen);
2327 * Add padding. At least four bytes, and must also bring total
2328 * length (minus MAC) up to a multiple of the block size.
2329 * If pkt->forcepad is set, make sure the packet is at least that size
2332 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2333 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2335 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2336 if (pkt->length + padding < pkt->forcepad)
2337 padding = pkt->forcepad - pkt->length;
2339 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2341 assert(padding <= 255);
2342 maclen = ssh->csmac ? ssh->csmac->len : 0;
2343 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2344 pkt->data[4] = padding;
2345 for (i = 0; i < padding; i++)
2346 pkt->data[pkt->length + i] = random_byte();
2347 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2349 /* Encrypt length if the scheme requires it */
2350 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2351 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2352 ssh->v2_outgoing_sequence);
2355 if (ssh->csmac && ssh->csmac_etm) {
2357 * OpenSSH-defined encrypt-then-MAC protocol.
2360 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2361 pkt->data + 4, pkt->length + padding - 4);
2362 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2363 pkt->length + padding,
2364 ssh->v2_outgoing_sequence);
2367 * SSH-2 standard protocol.
2370 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2371 pkt->length + padding,
2372 ssh->v2_outgoing_sequence);
2374 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2375 pkt->data, pkt->length + padding);
2378 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2379 pkt->encrypted_len = pkt->length + padding;
2381 /* Ready-to-send packet starts at pkt->data. We return length. */
2382 pkt->body = pkt->data;
2383 return pkt->length + padding + maclen;
2387 * Routines called from the main SSH code to send packets. There
2388 * are quite a few of these, because we have two separate
2389 * mechanisms for delaying the sending of packets:
2391 * - In order to send an IGNORE message and a password message in
2392 * a single fixed-length blob, we require the ability to
2393 * concatenate the encrypted forms of those two packets _into_ a
2394 * single blob and then pass it to our <network.h> transport
2395 * layer in one go. Hence, there's a deferment mechanism which
2396 * works after packet encryption.
2398 * - In order to avoid sending any connection-layer messages
2399 * during repeat key exchange, we have to queue up any such
2400 * outgoing messages _before_ they are encrypted (and in
2401 * particular before they're allocated sequence numbers), and
2402 * then send them once we've finished.
2404 * I call these mechanisms `defer' and `queue' respectively, so as
2405 * to distinguish them reasonably easily.
2407 * The functions send_noqueue() and defer_noqueue() free the packet
2408 * structure they are passed. Every outgoing packet goes through
2409 * precisely one of these functions in its life; packets passed to
2410 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2411 * these or get queued, and then when the queue is later emptied
2412 * the packets are all passed to defer_noqueue().
2414 * When using a CBC-mode cipher, it's necessary to ensure that an
2415 * attacker can't provide data to be encrypted using an IV that they
2416 * know. We ensure this by prefixing each packet that might contain
2417 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2418 * mechanism, so in this case send_noqueue() ends up redirecting to
2419 * defer_noqueue(). If you don't like this inefficiency, don't use
2423 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2424 static void ssh_pkt_defersend(Ssh);
2427 * Send an SSH-2 packet immediately, without queuing or deferring.
2429 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2433 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2434 /* We need to send two packets, so use the deferral mechanism. */
2435 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2436 ssh_pkt_defersend(ssh);
2439 len = ssh2_pkt_construct(ssh, pkt);
2440 backlog = s_write(ssh, pkt->body, len);
2441 if (backlog > SSH_MAX_BACKLOG)
2442 ssh_throttle_all(ssh, 1, backlog);
2444 ssh->outgoing_data_size += pkt->encrypted_len;
2445 if (!ssh->kex_in_progress &&
2446 !ssh->bare_connection &&
2447 ssh->max_data_size != 0 &&
2448 ssh->outgoing_data_size > ssh->max_data_size)
2449 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2451 ssh_free_packet(pkt);
2455 * Defer an SSH-2 packet.
2457 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2460 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2461 ssh->deferred_len == 0 && !noignore &&
2462 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2464 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2465 * get encrypted with a known IV.
2467 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2468 ssh2_pkt_addstring_start(ipkt);
2469 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2471 len = ssh2_pkt_construct(ssh, pkt);
2472 if (ssh->deferred_len + len > ssh->deferred_size) {
2473 ssh->deferred_size = ssh->deferred_len + len + 128;
2474 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2478 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2479 ssh->deferred_len += len;
2480 ssh->deferred_data_size += pkt->encrypted_len;
2481 ssh_free_packet(pkt);
2485 * Queue an SSH-2 packet.
2487 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2489 assert(ssh->queueing);
2491 if (ssh->queuelen >= ssh->queuesize) {
2492 ssh->queuesize = ssh->queuelen + 32;
2493 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2496 ssh->queue[ssh->queuelen++] = pkt;
2500 * Either queue or send a packet, depending on whether queueing is
2503 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2506 ssh2_pkt_queue(ssh, pkt);
2508 ssh2_pkt_send_noqueue(ssh, pkt);
2512 * Either queue or defer a packet, depending on whether queueing is
2515 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2518 ssh2_pkt_queue(ssh, pkt);
2520 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2524 * Send the whole deferred data block constructed by
2525 * ssh2_pkt_defer() or SSH-1's defer_packet().
2527 * The expected use of the defer mechanism is that you call
2528 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2529 * not currently queueing, this simply sets up deferred_send_data
2530 * and then sends it. If we _are_ currently queueing, the calls to
2531 * ssh2_pkt_defer() put the deferred packets on to the queue
2532 * instead, and therefore ssh_pkt_defersend() has no deferred data
2533 * to send. Hence, there's no need to make it conditional on
2536 static void ssh_pkt_defersend(Ssh ssh)
2539 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2540 ssh->deferred_len = ssh->deferred_size = 0;
2541 sfree(ssh->deferred_send_data);
2542 ssh->deferred_send_data = NULL;
2543 if (backlog > SSH_MAX_BACKLOG)
2544 ssh_throttle_all(ssh, 1, backlog);
2546 if (ssh->version == 2) {
2547 ssh->outgoing_data_size += ssh->deferred_data_size;
2548 ssh->deferred_data_size = 0;
2549 if (!ssh->kex_in_progress &&
2550 !ssh->bare_connection &&
2551 ssh->max_data_size != 0 &&
2552 ssh->outgoing_data_size > ssh->max_data_size)
2553 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2558 * Send a packet whose length needs to be disguised (typically
2559 * passwords or keyboard-interactive responses).
2561 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2567 * The simplest way to do this is to adjust the
2568 * variable-length padding field in the outgoing packet.
2570 * Currently compiled out, because some Cisco SSH servers
2571 * don't like excessively padded packets (bah, why's it
2574 pkt->forcepad = padsize;
2575 ssh2_pkt_send(ssh, pkt);
2580 * If we can't do that, however, an alternative approach is
2581 * to use the pkt_defer mechanism to bundle the packet
2582 * tightly together with an SSH_MSG_IGNORE such that their
2583 * combined length is a constant. So first we construct the
2584 * final form of this packet and defer its sending.
2586 ssh2_pkt_defer(ssh, pkt);
2589 * Now construct an SSH_MSG_IGNORE which includes a string
2590 * that's an exact multiple of the cipher block size. (If
2591 * the cipher is NULL so that the block size is
2592 * unavailable, we don't do this trick at all, because we
2593 * gain nothing by it.)
2595 if (ssh->cscipher &&
2596 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2599 stringlen = (256 - ssh->deferred_len);
2600 stringlen += ssh->cscipher->blksize - 1;
2601 stringlen -= (stringlen % ssh->cscipher->blksize);
2604 * Temporarily disable actual compression, so we
2605 * can guarantee to get this string exactly the
2606 * length we want it. The compression-disabling
2607 * routine should return an integer indicating how
2608 * many bytes we should adjust our string length
2612 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2614 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2615 ssh2_pkt_addstring_start(pkt);
2616 for (i = 0; i < stringlen; i++) {
2617 char c = (char) random_byte();
2618 ssh2_pkt_addstring_data(pkt, &c, 1);
2620 ssh2_pkt_defer(ssh, pkt);
2622 ssh_pkt_defersend(ssh);
2627 * Send all queued SSH-2 packets. We send them by means of
2628 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2629 * packets that needed to be lumped together.
2631 static void ssh2_pkt_queuesend(Ssh ssh)
2635 assert(!ssh->queueing);
2637 for (i = 0; i < ssh->queuelen; i++)
2638 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2641 ssh_pkt_defersend(ssh);
2645 void bndebug(char *string, Bignum b)
2649 p = ssh2_mpint_fmt(b, &len);
2650 debug(("%s", string));
2651 for (i = 0; i < len; i++)
2652 debug((" %02x", p[i]));
2658 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2662 p = ssh2_mpint_fmt(b, &len);
2663 hash_string(h, s, p, len);
2668 * Packet decode functions for both SSH-1 and SSH-2.
2670 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2672 unsigned long value;
2673 if (pkt->length - pkt->savedpos < 4)
2674 return 0; /* arrgh, no way to decline (FIXME?) */
2675 value = GET_32BIT(pkt->body + pkt->savedpos);
2679 static int ssh2_pkt_getbool(struct Packet *pkt)
2681 unsigned long value;
2682 if (pkt->length - pkt->savedpos < 1)
2683 return 0; /* arrgh, no way to decline (FIXME?) */
2684 value = pkt->body[pkt->savedpos] != 0;
2688 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2693 if (pkt->length - pkt->savedpos < 4)
2695 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2700 if (pkt->length - pkt->savedpos < *length)
2702 *p = (char *)(pkt->body + pkt->savedpos);
2703 pkt->savedpos += *length;
2705 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2707 if (pkt->length - pkt->savedpos < length)
2709 pkt->savedpos += length;
2710 return pkt->body + (pkt->savedpos - length);
2712 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2713 const unsigned char **keystr)
2717 j = makekey(pkt->body + pkt->savedpos,
2718 pkt->length - pkt->savedpos,
2725 assert(pkt->savedpos < pkt->length);
2729 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2734 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2735 pkt->length - pkt->savedpos, &b);
2743 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2749 ssh_pkt_getstring(pkt, &p, &length);
2754 b = bignum_from_bytes((unsigned char *)p, length);
2759 * Helper function to add an SSH-2 signature blob to a packet.
2760 * Expects to be shown the public key blob as well as the signature
2761 * blob. Normally works just like ssh2_pkt_addstring, but will
2762 * fiddle with the signature packet if necessary for
2763 * BUG_SSH2_RSA_PADDING.
2765 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2766 void *pkblob_v, int pkblob_len,
2767 void *sigblob_v, int sigblob_len)
2769 unsigned char *pkblob = (unsigned char *)pkblob_v;
2770 unsigned char *sigblob = (unsigned char *)sigblob_v;
2772 /* dmemdump(pkblob, pkblob_len); */
2773 /* dmemdump(sigblob, sigblob_len); */
2776 * See if this is in fact an ssh-rsa signature and a buggy
2777 * server; otherwise we can just do this the easy way.
2779 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2780 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2781 int pos, len, siglen;
2784 * Find the byte length of the modulus.
2787 pos = 4+7; /* skip over "ssh-rsa" */
2788 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2789 if (len < 0 || len > pkblob_len - pos - 4)
2791 pos += 4 + len; /* skip over exponent */
2792 if (pkblob_len - pos < 4)
2794 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2795 if (len < 0 || len > pkblob_len - pos - 4)
2797 pos += 4; /* find modulus itself */
2798 while (len > 0 && pkblob[pos] == 0)
2800 /* debug(("modulus length is %d\n", len)); */
2803 * Now find the signature integer.
2805 pos = 4+7; /* skip over "ssh-rsa" */
2806 if (sigblob_len < pos+4)
2808 siglen = toint(GET_32BIT(sigblob+pos));
2809 if (siglen != sigblob_len - pos - 4)
2811 /* debug(("signature length is %d\n", siglen)); */
2813 if (len != siglen) {
2814 unsigned char newlen[4];
2815 ssh2_pkt_addstring_start(pkt);
2816 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2817 /* dmemdump(sigblob, pos); */
2818 pos += 4; /* point to start of actual sig */
2819 PUT_32BIT(newlen, len);
2820 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2821 /* dmemdump(newlen, 4); */
2823 while (len-- > siglen) {
2824 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2825 /* dmemdump(newlen, 1); */
2827 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2828 /* dmemdump(sigblob+pos, siglen); */
2832 /* Otherwise fall through and do it the easy way. We also come
2833 * here as a fallback if we discover above that the key blob
2834 * is misformatted in some way. */
2838 ssh2_pkt_addstring_start(pkt);
2839 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2843 * Examine the remote side's version string and compare it against
2844 * a list of known buggy implementations.
2846 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2848 char *imp; /* pointer to implementation part */
2850 imp += strcspn(imp, "-");
2852 imp += strcspn(imp, "-");
2855 ssh->remote_bugs = 0;
2858 * General notes on server version strings:
2859 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2860 * here -- in particular, we've heard of one that's perfectly happy
2861 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2862 * so we can't distinguish them.
2864 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2865 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2866 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2867 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2868 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2869 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2871 * These versions don't support SSH1_MSG_IGNORE, so we have
2872 * to use a different defence against password length
2875 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2876 logevent("We believe remote version has SSH-1 ignore bug");
2879 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2880 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2881 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2883 * These versions need a plain password sent; they can't
2884 * handle having a null and a random length of data after
2887 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2888 logevent("We believe remote version needs a plain SSH-1 password");
2891 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2892 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2893 (!strcmp(imp, "Cisco-1.25")))) {
2895 * These versions apparently have no clue whatever about
2896 * RSA authentication and will panic and die if they see
2897 * an AUTH_RSA message.
2899 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2900 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2903 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2904 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2905 !wc_match("* VShell", imp) &&
2906 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2907 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2908 wc_match("2.1 *", imp)))) {
2910 * These versions have the HMAC bug.
2912 ssh->remote_bugs |= BUG_SSH2_HMAC;
2913 logevent("We believe remote version has SSH-2 HMAC bug");
2916 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2917 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2918 !wc_match("* VShell", imp) &&
2919 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2921 * These versions have the key-derivation bug (failing to
2922 * include the literal shared secret in the hashes that
2923 * generate the keys).
2925 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2926 logevent("We believe remote version has SSH-2 key-derivation bug");
2929 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2930 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2931 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2932 wc_match("OpenSSH_3.[0-2]*", imp) ||
2933 wc_match("mod_sftp/0.[0-8]*", imp) ||
2934 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2936 * These versions have the SSH-2 RSA padding bug.
2938 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2939 logevent("We believe remote version has SSH-2 RSA padding bug");
2942 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2943 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2944 wc_match("OpenSSH_2.[0-2]*", imp))) {
2946 * These versions have the SSH-2 session-ID bug in
2947 * public-key authentication.
2949 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2950 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2953 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2954 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2955 (wc_match("DigiSSH_2.0", imp) ||
2956 wc_match("OpenSSH_2.[0-4]*", imp) ||
2957 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2958 wc_match("Sun_SSH_1.0", imp) ||
2959 wc_match("Sun_SSH_1.0.1", imp) ||
2960 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2961 wc_match("WeOnlyDo-*", imp)))) {
2963 * These versions have the SSH-2 rekey bug.
2965 ssh->remote_bugs |= BUG_SSH2_REKEY;
2966 logevent("We believe remote version has SSH-2 rekey bug");
2969 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2970 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2971 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2972 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2974 * This version ignores our makpkt and needs to be throttled.
2976 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2977 logevent("We believe remote version ignores SSH-2 maximum packet size");
2980 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2982 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2983 * none detected automatically.
2985 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2986 logevent("We believe remote version has SSH-2 ignore bug");
2989 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2990 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2991 (wc_match("OpenSSH_2.[235]*", imp)))) {
2993 * These versions only support the original (pre-RFC4419)
2994 * SSH-2 GEX request, and disconnect with a protocol error if
2995 * we use the newer version.
2997 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2998 logevent("We believe remote version has outdated SSH-2 GEX");
3001 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
3003 * Servers that don't support our winadj request for one
3004 * reason or another. Currently, none detected automatically.
3006 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
3007 logevent("We believe remote version has winadj bug");
3010 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
3011 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
3012 (wc_match("OpenSSH_[2-5].*", imp) ||
3013 wc_match("OpenSSH_6.[0-6]*", imp) ||
3014 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
3015 wc_match("dropbear_0.5[01]*", imp)))) {
3017 * These versions have the SSH-2 channel request bug.
3018 * OpenSSH 6.7 and above do not:
3019 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
3020 * dropbear_0.52 and above do not:
3021 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
3023 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
3024 logevent("We believe remote version has SSH-2 channel request bug");
3029 * The `software version' part of an SSH version string is required
3030 * to contain no spaces or minus signs.
3032 static void ssh_fix_verstring(char *str)
3034 /* Eat "<protoversion>-". */
3035 while (*str && *str != '-') str++;
3036 assert(*str == '-'); str++;
3038 /* Convert minus signs and spaces in the remaining string into
3041 if (*str == '-' || *str == ' ')
3048 * Send an appropriate SSH version string.
3050 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3054 if (ssh->version == 2) {
3056 * Construct a v2 version string.
3058 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3061 * Construct a v1 version string.
3063 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3064 verstring = dupprintf("SSH-%s-%s\012",
3065 (ssh_versioncmp(svers, "1.5") <= 0 ?
3070 ssh_fix_verstring(verstring + strlen(protoname));
3072 /* FUZZING make PuTTY insecure, so make live use difficult. */
3076 if (ssh->version == 2) {
3079 * Record our version string.
3081 len = strcspn(verstring, "\015\012");
3082 ssh->v_c = snewn(len + 1, char);
3083 memcpy(ssh->v_c, verstring, len);
3087 logeventf(ssh, "We claim version: %.*s",
3088 strcspn(verstring, "\015\012"), verstring);
3089 s_write(ssh, verstring, strlen(verstring));
3093 static int do_ssh_init(Ssh ssh, unsigned char c)
3095 static const char protoname[] = "SSH-";
3097 struct do_ssh_init_state {
3106 crState(do_ssh_init_state);
3110 /* Search for a line beginning with the protocol name prefix in
3113 for (s->i = 0; protoname[s->i]; s->i++) {
3114 if ((char)c != protoname[s->i]) goto no;
3124 ssh->session_started = TRUE;
3126 s->vstrsize = sizeof(protoname) + 16;
3127 s->vstring = snewn(s->vstrsize, char);
3128 strcpy(s->vstring, protoname);
3129 s->vslen = strlen(protoname);
3132 if (s->vslen >= s->vstrsize - 1) {
3134 s->vstring = sresize(s->vstring, s->vstrsize, char);
3136 s->vstring[s->vslen++] = c;
3139 s->version[s->i] = '\0';
3141 } else if (s->i < sizeof(s->version) - 1)
3142 s->version[s->i++] = c;
3143 } else if (c == '\012')
3145 crReturn(1); /* get another char */
3148 ssh->agentfwd_enabled = FALSE;
3149 ssh->rdpkt2_state.incoming_sequence = 0;
3151 s->vstring[s->vslen] = 0;
3152 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3153 logeventf(ssh, "Server version: %s", s->vstring);
3154 ssh_detect_bugs(ssh, s->vstring);
3157 * Decide which SSH protocol version to support.
3160 /* Anything strictly below "2.0" means protocol 1 is supported. */
3161 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3162 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3163 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3165 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3167 bombout(("SSH protocol version 1 required by our configuration "
3168 "but not provided by server"));
3171 } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) {
3173 bombout(("SSH protocol version 2 required by our configuration "
3174 "but server only provides (old, insecure) SSH-1"));
3178 /* No longer support values 1 or 2 for CONF_sshprot */
3179 assert(!"Unexpected value for CONF_sshprot");
3182 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3187 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3189 /* Send the version string, if we haven't already */
3190 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3191 ssh_send_verstring(ssh, protoname, s->version);
3193 if (ssh->version == 2) {
3196 * Record their version string.
3198 len = strcspn(s->vstring, "\015\012");
3199 ssh->v_s = snewn(len + 1, char);
3200 memcpy(ssh->v_s, s->vstring, len);
3204 * Initialise SSH-2 protocol.
3206 ssh->protocol = ssh2_protocol;
3207 ssh2_protocol_setup(ssh);
3208 ssh->s_rdpkt = ssh2_rdpkt;
3211 * Initialise SSH-1 protocol.
3213 ssh->protocol = ssh1_protocol;
3214 ssh1_protocol_setup(ssh);
3215 ssh->s_rdpkt = ssh1_rdpkt;
3217 if (ssh->version == 2)
3218 do_ssh2_transport(ssh, NULL, -1, NULL);
3220 update_specials_menu(ssh->frontend);
3221 ssh->state = SSH_STATE_BEFORE_SIZE;
3222 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3229 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3232 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3233 * the ssh-connection part, extracted and given a trivial binary
3234 * packet protocol, so we replace 'SSH-' at the start with a new
3235 * name. In proper SSH style (though of course this part of the
3236 * proper SSH protocol _isn't_ subject to this kind of
3237 * DNS-domain-based extension), we define the new name in our
3240 static const char protoname[] =
3241 "SSHCONNECTION@putty.projects.tartarus.org-";
3243 struct do_ssh_connection_init_state {
3251 crState(do_ssh_connection_init_state);
3255 /* Search for a line beginning with the protocol name prefix in
3258 for (s->i = 0; protoname[s->i]; s->i++) {
3259 if ((char)c != protoname[s->i]) goto no;
3269 s->vstrsize = sizeof(protoname) + 16;
3270 s->vstring = snewn(s->vstrsize, char);
3271 strcpy(s->vstring, protoname);
3272 s->vslen = strlen(protoname);
3275 if (s->vslen >= s->vstrsize - 1) {
3277 s->vstring = sresize(s->vstring, s->vstrsize, char);
3279 s->vstring[s->vslen++] = c;
3282 s->version[s->i] = '\0';
3284 } else if (s->i < sizeof(s->version) - 1)
3285 s->version[s->i++] = c;
3286 } else if (c == '\012')
3288 crReturn(1); /* get another char */
3291 ssh->agentfwd_enabled = FALSE;
3292 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3294 s->vstring[s->vslen] = 0;
3295 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3296 logeventf(ssh, "Server version: %s", s->vstring);
3297 ssh_detect_bugs(ssh, s->vstring);
3300 * Decide which SSH protocol version to support. This is easy in
3301 * bare ssh-connection mode: only 2.0 is legal.
3303 if (ssh_versioncmp(s->version, "2.0") < 0) {
3304 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3307 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3308 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3314 logeventf(ssh, "Using bare ssh-connection protocol");
3316 /* Send the version string, if we haven't already */
3317 ssh_send_verstring(ssh, protoname, s->version);
3320 * Initialise bare connection protocol.
3322 ssh->protocol = ssh2_bare_connection_protocol;
3323 ssh2_bare_connection_protocol_setup(ssh);
3324 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3326 update_specials_menu(ssh->frontend);
3327 ssh->state = SSH_STATE_BEFORE_SIZE;
3328 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3331 * Get authconn (really just conn) under way.
3333 do_ssh2_authconn(ssh, NULL, 0, NULL);
3340 static void ssh_process_incoming_data(Ssh ssh,
3341 const unsigned char **data, int *datalen)
3343 struct Packet *pktin;
3345 pktin = ssh->s_rdpkt(ssh, data, datalen);
3347 ssh->protocol(ssh, NULL, 0, pktin);
3348 ssh_free_packet(pktin);
3352 static void ssh_queue_incoming_data(Ssh ssh,
3353 const unsigned char **data, int *datalen)
3355 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3360 static void ssh_process_queued_incoming_data(Ssh ssh)
3363 const unsigned char *data;
3366 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3367 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3371 while (!ssh->frozen && len > 0)
3372 ssh_process_incoming_data(ssh, &data, &len);
3375 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3379 static void ssh_set_frozen(Ssh ssh, int frozen)
3382 sk_set_frozen(ssh->s, frozen);
3383 ssh->frozen = frozen;
3386 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3388 /* Log raw data, if we're in that mode. */
3390 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3391 0, NULL, NULL, 0, NULL);
3393 crBegin(ssh->ssh_gotdata_crstate);
3396 * To begin with, feed the characters one by one to the
3397 * protocol initialisation / selection function do_ssh_init().
3398 * When that returns 0, we're done with the initial greeting
3399 * exchange and can move on to packet discipline.
3402 int ret; /* need not be kept across crReturn */
3404 crReturnV; /* more data please */
3405 ret = ssh->do_ssh_init(ssh, *data);
3413 * We emerge from that loop when the initial negotiation is
3414 * over and we have selected an s_rdpkt function. Now pass
3415 * everything to s_rdpkt, and then pass the resulting packets
3416 * to the proper protocol handler.
3420 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3422 ssh_queue_incoming_data(ssh, &data, &datalen);
3423 /* This uses up all data and cannot cause anything interesting
3424 * to happen; indeed, for anything to happen at all, we must
3425 * return, so break out. */
3427 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3428 /* This uses up some or all data, and may freeze the
3430 ssh_process_queued_incoming_data(ssh);
3432 /* This uses up some or all data, and may freeze the
3434 ssh_process_incoming_data(ssh, &data, &datalen);
3436 /* FIXME this is probably EBW. */
3437 if (ssh->state == SSH_STATE_CLOSED)
3440 /* We're out of data. Go and get some more. */
3446 static int ssh_do_close(Ssh ssh, int notify_exit)
3449 struct ssh_channel *c;
3451 ssh->state = SSH_STATE_CLOSED;
3452 expire_timer_context(ssh);
3457 notify_remote_exit(ssh->frontend);
3462 * Now we must shut down any port- and X-forwarded channels going
3463 * through this connection.
3465 if (ssh->channels) {
3466 while (NULL != (c = index234(ssh->channels, 0))) {
3469 x11_close(c->u.x11.xconn);
3472 pfd_close(c->u.pfd.pf);
3475 del234(ssh->channels, c); /* moving next one to index 0 */
3476 if (ssh->version == 2)
3477 bufchain_clear(&c->v.v2.outbuffer);
3482 * Go through port-forwardings, and close any associated
3483 * listening sockets.
3485 if (ssh->portfwds) {
3486 struct ssh_portfwd *pf;
3487 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3488 /* Dispose of any listening socket. */
3490 pfl_terminate(pf->local);
3491 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3494 freetree234(ssh->portfwds);
3495 ssh->portfwds = NULL;
3499 * Also stop attempting to connection-share.
3501 if (ssh->connshare) {
3502 sharestate_free(ssh->connshare);
3503 ssh->connshare = NULL;
3509 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3510 const char *error_msg, int error_code)
3512 Ssh ssh = (Ssh) plug;
3515 * While we're attempting connection sharing, don't loudly log
3516 * everything that happens. Real TCP connections need to be logged
3517 * when we _start_ trying to connect, because it might be ages
3518 * before they respond if something goes wrong; but connection
3519 * sharing is local and quick to respond, and it's sufficient to
3520 * simply wait and see whether it worked afterwards.
3523 if (!ssh->attempting_connshare)
3524 backend_socket_log(ssh->frontend, type, addr, port,
3525 error_msg, error_code, ssh->conf,
3526 ssh->session_started);
3529 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3530 const char *ds_err, const char *us_err)
3532 if (event == SHARE_NONE) {
3533 /* In this case, 'logtext' is an error message indicating a
3534 * reason why connection sharing couldn't be set up _at all_.
3535 * Failing that, ds_err and us_err indicate why we couldn't be
3536 * a downstream and an upstream respectively. */
3538 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3541 logeventf(ssh, "Could not set up connection sharing"
3542 " as downstream: %s", ds_err);
3544 logeventf(ssh, "Could not set up connection sharing"
3545 " as upstream: %s", us_err);
3547 } else if (event == SHARE_DOWNSTREAM) {
3548 /* In this case, 'logtext' is a local endpoint address */
3549 logeventf(ssh, "Using existing shared connection at %s", logtext);
3550 /* Also we should mention this in the console window to avoid
3551 * confusing users as to why this window doesn't behave the
3553 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3554 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3556 } else if (event == SHARE_UPSTREAM) {
3557 /* In this case, 'logtext' is a local endpoint address too */
3558 logeventf(ssh, "Sharing this connection at %s", logtext);
3562 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3565 Ssh ssh = (Ssh) plug;
3566 int need_notify = ssh_do_close(ssh, FALSE);
3569 if (!ssh->close_expected)
3570 error_msg = "Server unexpectedly closed network connection";
3572 error_msg = "Server closed network connection";
3575 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3579 notify_remote_exit(ssh->frontend);
3582 logevent(error_msg);
3583 if (!ssh->close_expected || !ssh->clean_exit)
3584 connection_fatal(ssh->frontend, "%s", error_msg);
3588 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3590 Ssh ssh = (Ssh) plug;
3591 ssh_gotdata(ssh, (unsigned char *)data, len);
3592 if (ssh->state == SSH_STATE_CLOSED) {
3593 ssh_do_close(ssh, TRUE);
3599 static void ssh_sent(Plug plug, int bufsize)
3601 Ssh ssh = (Ssh) plug;
3603 * If the send backlog on the SSH socket itself clears, we
3604 * should unthrottle the whole world if it was throttled.
3606 if (bufsize < SSH_MAX_BACKLOG)
3607 ssh_throttle_all(ssh, 0, bufsize);
3610 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3611 char **savedhost, int *savedport,
3614 char *loghost = conf_get_str(conf, CONF_loghost);
3616 *loghost_ret = loghost;
3622 tmphost = dupstr(loghost);
3623 *savedport = 22; /* default ssh port */
3626 * A colon suffix on the hostname string also lets us affect
3627 * savedport. (Unless there are multiple colons, in which case
3628 * we assume this is an unbracketed IPv6 literal.)
3630 colon = host_strrchr(tmphost, ':');
3631 if (colon && colon == host_strchr(tmphost, ':')) {
3634 *savedport = atoi(colon);
3637 *savedhost = host_strduptrim(tmphost);
3640 *savedhost = host_strduptrim(host);
3642 port = 22; /* default ssh port */
3647 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3653 random_ref(); /* platform may need this to determine share socket name */
3654 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3655 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3663 * Connect to specified host and port.
3664 * Returns an error message, or NULL on success.
3665 * Also places the canonical host name into `realhost'. It must be
3666 * freed by the caller.
3668 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3669 char **realhost, int nodelay, int keepalive)
3671 static const struct plug_function_table fn_table = {
3682 int addressfamily, sshprot;
3684 ssh_hostport_setup(host, port, ssh->conf,
3685 &ssh->savedhost, &ssh->savedport, &loghost);
3687 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3690 * Try connection-sharing, in case that means we don't open a
3691 * socket after all. ssh_connection_sharing_init will connect to a
3692 * previously established upstream if it can, and failing that,
3693 * establish a listening socket for _us_ to be the upstream. In
3694 * the latter case it will return NULL just as if it had done
3695 * nothing, because here we only need to care if we're a
3696 * downstream and need to do our connection setup differently.
3698 ssh->connshare = NULL;
3699 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3700 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3701 ssh->conf, ssh, &ssh->connshare);
3702 ssh->attempting_connshare = FALSE;
3703 if (ssh->s != NULL) {
3705 * We are a downstream.
3707 ssh->bare_connection = TRUE;
3708 ssh->do_ssh_init = do_ssh_connection_init;
3709 ssh->fullhostname = NULL;
3710 *realhost = dupstr(host); /* best we can do */
3713 * We're not a downstream, so open a normal socket.
3715 ssh->do_ssh_init = do_ssh_init;
3720 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3721 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3722 ssh->frontend, "SSH connection");
3723 if ((err = sk_addr_error(addr)) != NULL) {
3727 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3729 ssh->s = new_connection(addr, *realhost, port,
3730 0, 1, nodelay, keepalive,
3731 (Plug) ssh, ssh->conf);
3732 if ((err = sk_socket_error(ssh->s)) != NULL) {
3734 notify_remote_exit(ssh->frontend);
3740 * The SSH version number is always fixed (since we no longer support
3741 * fallback between versions), so set it now, and if it's SSH-2,
3742 * send the version string now too.
3744 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3745 assert(sshprot == 0 || sshprot == 3);
3749 if (sshprot == 3 && !ssh->bare_connection) {
3752 ssh_send_verstring(ssh, "SSH-", NULL);
3756 * loghost, if configured, overrides realhost.
3760 *realhost = dupstr(loghost);
3767 * Throttle or unthrottle the SSH connection.
3769 static void ssh_throttle_conn(Ssh ssh, int adjust)
3771 int old_count = ssh->conn_throttle_count;
3772 ssh->conn_throttle_count += adjust;
3773 assert(ssh->conn_throttle_count >= 0);
3774 if (ssh->conn_throttle_count && !old_count) {
3775 ssh_set_frozen(ssh, 1);
3776 } else if (!ssh->conn_throttle_count && old_count) {
3777 ssh_set_frozen(ssh, 0);
3782 * Throttle or unthrottle _all_ local data streams (for when sends
3783 * on the SSH connection itself back up).
3785 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3788 struct ssh_channel *c;
3790 if (enable == ssh->throttled_all)
3792 ssh->throttled_all = enable;
3793 ssh->overall_bufsize = bufsize;
3796 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3798 case CHAN_MAINSESSION:
3800 * This is treated separately, outside the switch.
3804 x11_override_throttle(c->u.x11.xconn, enable);
3807 /* Agent channels require no buffer management. */
3810 pfd_override_throttle(c->u.pfd.pf, enable);
3816 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3818 Ssh ssh = (Ssh) sshv;
3820 ssh->agent_response = reply;
3821 ssh->agent_response_len = replylen;
3823 if (ssh->version == 1)
3824 do_ssh1_login(ssh, NULL, -1, NULL);
3826 do_ssh2_authconn(ssh, NULL, -1, NULL);
3829 static void ssh_dialog_callback(void *sshv, int ret)
3831 Ssh ssh = (Ssh) sshv;
3833 ssh->user_response = ret;
3835 if (ssh->version == 1)
3836 do_ssh1_login(ssh, NULL, -1, NULL);
3838 do_ssh2_transport(ssh, NULL, -1, NULL);
3841 * This may have unfrozen the SSH connection, so do a
3844 ssh_process_queued_incoming_data(ssh);
3847 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3849 struct ssh_channel *c = (struct ssh_channel *)cv;
3850 const void *sentreply = reply;
3852 c->u.a.outstanding_requests--;
3854 /* Fake SSH_AGENT_FAILURE. */
3855 sentreply = "\0\0\0\1\5";
3858 ssh_send_channel_data(c, sentreply, replylen);
3862 * If we've already seen an incoming EOF but haven't sent an
3863 * outgoing one, this may be the moment to send it.
3865 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3866 sshfwd_write_eof(c);
3870 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3871 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3872 * => log `wire_reason'.
3874 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3875 const char *wire_reason,
3876 int code, int clean_exit)
3880 client_reason = wire_reason;
3882 error = dupprintf("Disconnected: %s", client_reason);
3884 error = dupstr("Disconnected");
3886 if (ssh->version == 1) {
3887 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3889 } else if (ssh->version == 2) {
3890 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3891 ssh2_pkt_adduint32(pktout, code);
3892 ssh2_pkt_addstring(pktout, wire_reason);
3893 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3894 ssh2_pkt_send_noqueue(ssh, pktout);
3897 ssh->close_expected = TRUE;
3898 ssh->clean_exit = clean_exit;
3899 ssh_closing((Plug)ssh, error, 0, 0);
3903 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3904 const struct ssh_signkey *ssh2keytype,
3907 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3908 return -1; /* no manual keys configured */
3913 * The fingerprint string we've been given will have things
3914 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3915 * narrow down to just the colon-separated hex block at the
3916 * end of the string.
3918 const char *p = strrchr(fingerprint, ' ');
3919 fingerprint = p ? p+1 : fingerprint;
3920 /* Quick sanity checks, including making sure it's in lowercase */
3921 assert(strlen(fingerprint) == 16*3 - 1);
3922 assert(fingerprint[2] == ':');
3923 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3925 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3927 return 1; /* success */
3932 * Construct the base64-encoded public key blob and see if
3935 unsigned char *binblob;
3937 int binlen, atoms, i;
3938 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3939 atoms = (binlen + 2) / 3;
3940 base64blob = snewn(atoms * 4 + 1, char);
3941 for (i = 0; i < atoms; i++)
3942 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3943 base64blob[atoms * 4] = '\0';
3945 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3948 return 1; /* success */
3957 * Handle the key exchange and user authentication phases.
3959 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3960 struct Packet *pktin)
3963 unsigned char cookie[8], *ptr;
3964 struct MD5Context md5c;
3965 struct do_ssh1_login_state {
3968 unsigned char *rsabuf;
3969 const unsigned char *keystr1, *keystr2;
3970 unsigned long supported_ciphers_mask, supported_auths_mask;
3971 int tried_publickey, tried_agent;
3972 int tis_auth_refused, ccard_auth_refused;
3973 unsigned char session_id[16];
3975 void *publickey_blob;
3976 int publickey_bloblen;
3977 char *publickey_comment;
3978 int privatekey_available, privatekey_encrypted;
3979 prompts_t *cur_prompt;
3982 unsigned char request[5], *response, *p;
3992 struct RSAKey servkey, hostkey;
3994 crState(do_ssh1_login_state);
4001 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
4002 bombout(("Public key packet not received"));
4006 logevent("Received public keys");
4008 ptr = ssh_pkt_getdata(pktin, 8);
4010 bombout(("SSH-1 public key packet stopped before random cookie"));
4013 memcpy(cookie, ptr, 8);
4015 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
4016 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
4017 bombout(("Failed to read SSH-1 public keys from public key packet"));
4022 * Log the host key fingerprint.
4026 logevent("Host key fingerprint is:");
4027 strcpy(logmsg, " ");
4028 s->hostkey.comment = NULL;
4029 rsa_fingerprint(logmsg + strlen(logmsg),
4030 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4034 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4035 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4036 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4037 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4038 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4040 ssh->v1_local_protoflags =
4041 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4042 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4045 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4046 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4047 MD5Update(&md5c, cookie, 8);
4048 MD5Final(s->session_id, &md5c);
4050 for (i = 0; i < 32; i++)
4051 ssh->session_key[i] = random_byte();
4054 * Verify that the `bits' and `bytes' parameters match.
4056 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4057 s->servkey.bits > s->servkey.bytes * 8) {
4058 bombout(("SSH-1 public keys were badly formatted"));
4062 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4063 s->hostkey.bytes : s->servkey.bytes);
4065 s->rsabuf = snewn(s->len, unsigned char);
4068 * Verify the host key.
4072 * First format the key into a string.
4074 int len = rsastr_len(&s->hostkey);
4075 char fingerprint[100];
4076 char *keystr = snewn(len, char);
4077 rsastr_fmt(keystr, &s->hostkey);
4078 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4080 /* First check against manually configured host keys. */
4081 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4082 if (s->dlgret == 0) { /* did not match */
4083 bombout(("Host key did not appear in manually configured list"));
4086 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4087 ssh_set_frozen(ssh, 1);
4088 s->dlgret = verify_ssh_host_key(ssh->frontend,
4089 ssh->savedhost, ssh->savedport,
4090 "rsa", keystr, fingerprint,
4091 ssh_dialog_callback, ssh);
4096 if (s->dlgret < 0) {
4100 bombout(("Unexpected data from server while waiting"
4101 " for user host key response"));
4104 } while (pktin || inlen > 0);
4105 s->dlgret = ssh->user_response;
4107 ssh_set_frozen(ssh, 0);
4109 if (s->dlgret == 0) {
4110 ssh_disconnect(ssh, "User aborted at host key verification",
4119 for (i = 0; i < 32; i++) {
4120 s->rsabuf[i] = ssh->session_key[i];
4122 s->rsabuf[i] ^= s->session_id[i];
4125 if (s->hostkey.bytes > s->servkey.bytes) {
4126 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4128 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4130 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4132 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4135 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4139 logevent("Encrypted session key");
4142 int cipher_chosen = 0, warn = 0;
4143 const char *cipher_string = NULL;
4145 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4146 int next_cipher = conf_get_int_int(ssh->conf,
4147 CONF_ssh_cipherlist, i);
4148 if (next_cipher == CIPHER_WARN) {
4149 /* If/when we choose a cipher, warn about it */
4151 } else if (next_cipher == CIPHER_AES) {
4152 /* XXX Probably don't need to mention this. */
4153 logevent("AES not supported in SSH-1, skipping");
4155 switch (next_cipher) {
4156 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4157 cipher_string = "3DES"; break;
4158 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4159 cipher_string = "Blowfish"; break;
4160 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4161 cipher_string = "single-DES"; break;
4163 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4167 if (!cipher_chosen) {
4168 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4169 bombout(("Server violates SSH-1 protocol by not "
4170 "supporting 3DES encryption"));
4172 /* shouldn't happen */
4173 bombout(("No supported ciphers found"));
4177 /* Warn about chosen cipher if necessary. */
4179 ssh_set_frozen(ssh, 1);
4180 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4181 ssh_dialog_callback, ssh);
4182 if (s->dlgret < 0) {
4186 bombout(("Unexpected data from server while waiting"
4187 " for user response"));
4190 } while (pktin || inlen > 0);
4191 s->dlgret = ssh->user_response;
4193 ssh_set_frozen(ssh, 0);
4194 if (s->dlgret == 0) {
4195 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4202 switch (s->cipher_type) {
4203 case SSH_CIPHER_3DES:
4204 logevent("Using 3DES encryption");
4206 case SSH_CIPHER_DES:
4207 logevent("Using single-DES encryption");
4209 case SSH_CIPHER_BLOWFISH:
4210 logevent("Using Blowfish encryption");
4214 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4215 PKT_CHAR, s->cipher_type,
4216 PKT_DATA, cookie, 8,
4217 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4218 PKT_DATA, s->rsabuf, s->len,
4219 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4221 logevent("Trying to enable encryption...");
4225 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4226 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4228 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4229 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4230 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4232 ssh->crcda_ctx = crcda_make_context();
4233 logevent("Installing CRC compensation attack detector");
4235 if (s->servkey.modulus) {
4236 sfree(s->servkey.modulus);
4237 s->servkey.modulus = NULL;
4239 if (s->servkey.exponent) {
4240 sfree(s->servkey.exponent);
4241 s->servkey.exponent = NULL;
4243 if (s->hostkey.modulus) {
4244 sfree(s->hostkey.modulus);
4245 s->hostkey.modulus = NULL;
4247 if (s->hostkey.exponent) {
4248 sfree(s->hostkey.exponent);
4249 s->hostkey.exponent = NULL;
4253 if (pktin->type != SSH1_SMSG_SUCCESS) {
4254 bombout(("Encryption not successfully enabled"));
4258 logevent("Successfully started encryption");
4260 fflush(stdout); /* FIXME eh? */
4262 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4263 int ret; /* need not be kept over crReturn */
4264 s->cur_prompt = new_prompts(ssh->frontend);
4265 s->cur_prompt->to_server = TRUE;
4266 s->cur_prompt->name = dupstr("SSH login name");
4267 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4268 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4271 crWaitUntil(!pktin);
4272 ret = get_userpass_input(s->cur_prompt, in, inlen);
4277 * Failed to get a username. Terminate.
4279 free_prompts(s->cur_prompt);
4280 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4283 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4284 free_prompts(s->cur_prompt);
4287 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4289 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4291 if (flags & FLAG_INTERACTIVE &&
4292 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4293 c_write_str(ssh, userlog);
4294 c_write_str(ssh, "\r\n");
4302 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4303 /* We must not attempt PK auth. Pretend we've already tried it. */
4304 s->tried_publickey = s->tried_agent = 1;
4306 s->tried_publickey = s->tried_agent = 0;
4308 s->tis_auth_refused = s->ccard_auth_refused = 0;
4310 * Load the public half of any configured keyfile for later use.
4312 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4313 if (!filename_is_null(s->keyfile)) {
4315 logeventf(ssh, "Reading key file \"%.150s\"",
4316 filename_to_str(s->keyfile));
4317 keytype = key_type(s->keyfile);
4318 if (keytype == SSH_KEYTYPE_SSH1 ||
4319 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4321 if (rsakey_pubblob(s->keyfile,
4322 &s->publickey_blob, &s->publickey_bloblen,
4323 &s->publickey_comment, &error)) {
4324 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4325 if (!s->privatekey_available)
4326 logeventf(ssh, "Key file contains public key only");
4327 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4331 logeventf(ssh, "Unable to load key (%s)", error);
4332 msgbuf = dupprintf("Unable to load key file "
4333 "\"%.150s\" (%s)\r\n",
4334 filename_to_str(s->keyfile),
4336 c_write_str(ssh, msgbuf);
4338 s->publickey_blob = NULL;
4342 logeventf(ssh, "Unable to use this key file (%s)",
4343 key_type_to_str(keytype));
4344 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4346 filename_to_str(s->keyfile),
4347 key_type_to_str(keytype));
4348 c_write_str(ssh, msgbuf);
4350 s->publickey_blob = NULL;
4353 s->publickey_blob = NULL;
4355 while (pktin->type == SSH1_SMSG_FAILURE) {
4356 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4358 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4360 * Attempt RSA authentication using Pageant.
4366 logevent("Pageant is running. Requesting keys.");
4368 /* Request the keys held by the agent. */
4369 PUT_32BIT(s->request, 1);
4370 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4371 if (!agent_query(s->request, 5, &r, &s->responselen,
4372 ssh_agent_callback, ssh)) {
4376 bombout(("Unexpected data from server while waiting"
4377 " for agent response"));
4380 } while (pktin || inlen > 0);
4381 r = ssh->agent_response;
4382 s->responselen = ssh->agent_response_len;
4384 s->response = (unsigned char *) r;
4385 if (s->response && s->responselen >= 5 &&
4386 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4387 s->p = s->response + 5;
4388 s->nkeys = toint(GET_32BIT(s->p));
4390 logeventf(ssh, "Pageant reported negative key count %d",
4395 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4396 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4397 unsigned char *pkblob = s->p;
4401 do { /* do while (0) to make breaking easy */
4402 n = ssh1_read_bignum
4403 (s->p, toint(s->responselen-(s->p-s->response)),
4408 n = ssh1_read_bignum
4409 (s->p, toint(s->responselen-(s->p-s->response)),
4414 if (s->responselen - (s->p-s->response) < 4)
4416 s->commentlen = toint(GET_32BIT(s->p));
4418 if (s->commentlen < 0 ||
4419 toint(s->responselen - (s->p-s->response)) <
4422 s->commentp = (char *)s->p;
4423 s->p += s->commentlen;
4427 logevent("Pageant key list packet was truncated");
4431 if (s->publickey_blob) {
4432 if (!memcmp(pkblob, s->publickey_blob,
4433 s->publickey_bloblen)) {
4434 logeventf(ssh, "Pageant key #%d matches "
4435 "configured key file", s->keyi);
4436 s->tried_publickey = 1;
4438 /* Skip non-configured key */
4441 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4442 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4443 PKT_BIGNUM, s->key.modulus, PKT_END);
4445 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4446 logevent("Key refused");
4449 logevent("Received RSA challenge");
4450 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4451 bombout(("Server's RSA challenge was badly formatted"));
4456 char *agentreq, *q, *ret;
4459 len = 1 + 4; /* message type, bit count */
4460 len += ssh1_bignum_length(s->key.exponent);
4461 len += ssh1_bignum_length(s->key.modulus);
4462 len += ssh1_bignum_length(s->challenge);
4463 len += 16; /* session id */
4464 len += 4; /* response format */
4465 agentreq = snewn(4 + len, char);
4466 PUT_32BIT(agentreq, len);
4468 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4469 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4471 q += ssh1_write_bignum(q, s->key.exponent);
4472 q += ssh1_write_bignum(q, s->key.modulus);
4473 q += ssh1_write_bignum(q, s->challenge);
4474 memcpy(q, s->session_id, 16);
4476 PUT_32BIT(q, 1); /* response format */
4477 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4478 ssh_agent_callback, ssh)) {
4483 bombout(("Unexpected data from server"
4484 " while waiting for agent"
4488 } while (pktin || inlen > 0);
4489 vret = ssh->agent_response;
4490 retlen = ssh->agent_response_len;
4495 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4496 logevent("Sending Pageant's response");
4497 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4498 PKT_DATA, ret + 5, 16,
4502 if (pktin->type == SSH1_SMSG_SUCCESS) {
4504 ("Pageant's response accepted");
4505 if (flags & FLAG_VERBOSE) {
4506 c_write_str(ssh, "Authenticated using"
4508 c_write(ssh, s->commentp,
4510 c_write_str(ssh, "\" from agent\r\n");
4515 ("Pageant's response not accepted");
4518 ("Pageant failed to answer challenge");
4522 logevent("No reply received from Pageant");
4525 freebn(s->key.exponent);
4526 freebn(s->key.modulus);
4527 freebn(s->challenge);
4532 if (s->publickey_blob && !s->tried_publickey)
4533 logevent("Configured key file not in Pageant");
4535 logevent("Failed to get reply from Pageant");
4540 if (s->publickey_blob && s->privatekey_available &&
4541 !s->tried_publickey) {
4543 * Try public key authentication with the specified
4546 int got_passphrase; /* need not be kept over crReturn */
4547 if (flags & FLAG_VERBOSE)
4548 c_write_str(ssh, "Trying public key authentication.\r\n");
4549 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4550 logeventf(ssh, "Trying public key \"%s\"",
4551 filename_to_str(s->keyfile));
4552 s->tried_publickey = 1;
4553 got_passphrase = FALSE;
4554 while (!got_passphrase) {
4556 * Get a passphrase, if necessary.
4558 char *passphrase = NULL; /* only written after crReturn */
4560 if (!s->privatekey_encrypted) {
4561 if (flags & FLAG_VERBOSE)
4562 c_write_str(ssh, "No passphrase required.\r\n");
4565 int ret; /* need not be kept over crReturn */
4566 s->cur_prompt = new_prompts(ssh->frontend);
4567 s->cur_prompt->to_server = FALSE;
4568 s->cur_prompt->name = dupstr("SSH key passphrase");
4569 add_prompt(s->cur_prompt,
4570 dupprintf("Passphrase for key \"%.100s\": ",
4571 s->publickey_comment), FALSE);
4572 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4575 crWaitUntil(!pktin);
4576 ret = get_userpass_input(s->cur_prompt, in, inlen);
4580 /* Failed to get a passphrase. Terminate. */
4581 free_prompts(s->cur_prompt);
4582 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4586 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4587 free_prompts(s->cur_prompt);
4590 * Try decrypting key with passphrase.
4592 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4593 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4596 smemclr(passphrase, strlen(passphrase));
4600 /* Correct passphrase. */
4601 got_passphrase = TRUE;
4602 } else if (ret == 0) {
4603 c_write_str(ssh, "Couldn't load private key from ");
4604 c_write_str(ssh, filename_to_str(s->keyfile));
4605 c_write_str(ssh, " (");
4606 c_write_str(ssh, error);
4607 c_write_str(ssh, ").\r\n");
4608 got_passphrase = FALSE;
4609 break; /* go and try something else */
4610 } else if (ret == -1) {
4611 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4612 got_passphrase = FALSE;
4615 assert(0 && "unexpected return from loadrsakey()");
4616 got_passphrase = FALSE; /* placate optimisers */
4620 if (got_passphrase) {
4623 * Send a public key attempt.
4625 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4626 PKT_BIGNUM, s->key.modulus, PKT_END);
4629 if (pktin->type == SSH1_SMSG_FAILURE) {
4630 c_write_str(ssh, "Server refused our public key.\r\n");
4631 continue; /* go and try something else */
4633 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4634 bombout(("Bizarre response to offer of public key"));
4640 unsigned char buffer[32];
4641 Bignum challenge, response;
4643 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4644 bombout(("Server's RSA challenge was badly formatted"));
4647 response = rsadecrypt(challenge, &s->key);
4648 freebn(s->key.private_exponent);/* burn the evidence */
4650 for (i = 0; i < 32; i++) {
4651 buffer[i] = bignum_byte(response, 31 - i);
4655 MD5Update(&md5c, buffer, 32);
4656 MD5Update(&md5c, s->session_id, 16);
4657 MD5Final(buffer, &md5c);
4659 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4660 PKT_DATA, buffer, 16, PKT_END);
4667 if (pktin->type == SSH1_SMSG_FAILURE) {
4668 if (flags & FLAG_VERBOSE)
4669 c_write_str(ssh, "Failed to authenticate with"
4670 " our public key.\r\n");
4671 continue; /* go and try something else */
4672 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4673 bombout(("Bizarre response to RSA authentication response"));
4677 break; /* we're through! */
4683 * Otherwise, try various forms of password-like authentication.
4685 s->cur_prompt = new_prompts(ssh->frontend);
4687 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4688 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4689 !s->tis_auth_refused) {
4690 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4691 logevent("Requested TIS authentication");
4692 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4694 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4695 logevent("TIS authentication declined");
4696 if (flags & FLAG_INTERACTIVE)
4697 c_write_str(ssh, "TIS authentication refused.\r\n");
4698 s->tis_auth_refused = 1;
4703 char *instr_suf, *prompt;
4705 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4707 bombout(("TIS challenge packet was badly formed"));
4710 logevent("Received TIS challenge");
4711 s->cur_prompt->to_server = TRUE;
4712 s->cur_prompt->name = dupstr("SSH TIS authentication");
4713 /* Prompt heuristic comes from OpenSSH */
4714 if (memchr(challenge, '\n', challengelen)) {
4715 instr_suf = dupstr("");
4716 prompt = dupprintf("%.*s", challengelen, challenge);
4718 instr_suf = dupprintf("%.*s", challengelen, challenge);
4719 prompt = dupstr("Response: ");
4721 s->cur_prompt->instruction =
4722 dupprintf("Using TIS authentication.%s%s",
4723 (*instr_suf) ? "\n" : "",
4725 s->cur_prompt->instr_reqd = TRUE;
4726 add_prompt(s->cur_prompt, prompt, FALSE);
4730 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4731 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4732 !s->ccard_auth_refused) {
4733 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4734 logevent("Requested CryptoCard authentication");
4735 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4737 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4738 logevent("CryptoCard authentication declined");
4739 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4740 s->ccard_auth_refused = 1;
4745 char *instr_suf, *prompt;
4747 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4749 bombout(("CryptoCard challenge packet was badly formed"));
4752 logevent("Received CryptoCard challenge");
4753 s->cur_prompt->to_server = TRUE;
4754 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4755 s->cur_prompt->name_reqd = FALSE;
4756 /* Prompt heuristic comes from OpenSSH */
4757 if (memchr(challenge, '\n', challengelen)) {
4758 instr_suf = dupstr("");
4759 prompt = dupprintf("%.*s", challengelen, challenge);
4761 instr_suf = dupprintf("%.*s", challengelen, challenge);
4762 prompt = dupstr("Response: ");
4764 s->cur_prompt->instruction =
4765 dupprintf("Using CryptoCard authentication.%s%s",
4766 (*instr_suf) ? "\n" : "",
4768 s->cur_prompt->instr_reqd = TRUE;
4769 add_prompt(s->cur_prompt, prompt, FALSE);
4773 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4774 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4775 bombout(("No supported authentication methods available"));
4778 s->cur_prompt->to_server = TRUE;
4779 s->cur_prompt->name = dupstr("SSH password");
4780 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4781 ssh->username, ssh->savedhost),
4786 * Show password prompt, having first obtained it via a TIS
4787 * or CryptoCard exchange if we're doing TIS or CryptoCard
4791 int ret; /* need not be kept over crReturn */
4792 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4795 crWaitUntil(!pktin);
4796 ret = get_userpass_input(s->cur_prompt, in, inlen);
4801 * Failed to get a password (for example
4802 * because one was supplied on the command line
4803 * which has already failed to work). Terminate.
4805 free_prompts(s->cur_prompt);
4806 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4811 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4813 * Defence against traffic analysis: we send a
4814 * whole bunch of packets containing strings of
4815 * different lengths. One of these strings is the
4816 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4817 * The others are all random data in
4818 * SSH1_MSG_IGNORE packets. This way a passive
4819 * listener can't tell which is the password, and
4820 * hence can't deduce the password length.
4822 * Anybody with a password length greater than 16
4823 * bytes is going to have enough entropy in their
4824 * password that a listener won't find it _that_
4825 * much help to know how long it is. So what we'll
4828 * - if password length < 16, we send 15 packets
4829 * containing string lengths 1 through 15
4831 * - otherwise, we let N be the nearest multiple
4832 * of 8 below the password length, and send 8
4833 * packets containing string lengths N through
4834 * N+7. This won't obscure the order of
4835 * magnitude of the password length, but it will
4836 * introduce a bit of extra uncertainty.
4838 * A few servers can't deal with SSH1_MSG_IGNORE, at
4839 * least in this context. For these servers, we need
4840 * an alternative defence. We make use of the fact
4841 * that the password is interpreted as a C string:
4842 * so we can append a NUL, then some random data.
4844 * A few servers can deal with neither SSH1_MSG_IGNORE
4845 * here _nor_ a padded password string.
4846 * For these servers we are left with no defences
4847 * against password length sniffing.
4849 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4850 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4852 * The server can deal with SSH1_MSG_IGNORE, so
4853 * we can use the primary defence.
4855 int bottom, top, pwlen, i;
4858 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4860 bottom = 0; /* zero length passwords are OK! :-) */
4863 bottom = pwlen & ~7;
4867 assert(pwlen >= bottom && pwlen <= top);
4869 randomstr = snewn(top + 1, char);
4871 for (i = bottom; i <= top; i++) {
4873 defer_packet(ssh, s->pwpkt_type,
4874 PKT_STR,s->cur_prompt->prompts[0]->result,
4877 for (j = 0; j < i; j++) {
4879 randomstr[j] = random_byte();
4880 } while (randomstr[j] == '\0');
4882 randomstr[i] = '\0';
4883 defer_packet(ssh, SSH1_MSG_IGNORE,
4884 PKT_STR, randomstr, PKT_END);
4887 logevent("Sending password with camouflage packets");
4888 ssh_pkt_defersend(ssh);
4891 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4893 * The server can't deal with SSH1_MSG_IGNORE
4894 * but can deal with padded passwords, so we
4895 * can use the secondary defence.
4901 len = strlen(s->cur_prompt->prompts[0]->result);
4902 if (len < sizeof(string)) {
4904 strcpy(string, s->cur_prompt->prompts[0]->result);
4905 len++; /* cover the zero byte */
4906 while (len < sizeof(string)) {
4907 string[len++] = (char) random_byte();
4910 ss = s->cur_prompt->prompts[0]->result;
4912 logevent("Sending length-padded password");
4913 send_packet(ssh, s->pwpkt_type,
4914 PKT_INT, len, PKT_DATA, ss, len,
4918 * The server is believed unable to cope with
4919 * any of our password camouflage methods.
4922 len = strlen(s->cur_prompt->prompts[0]->result);
4923 logevent("Sending unpadded password");
4924 send_packet(ssh, s->pwpkt_type,
4926 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4930 send_packet(ssh, s->pwpkt_type,
4931 PKT_STR, s->cur_prompt->prompts[0]->result,
4934 logevent("Sent password");
4935 free_prompts(s->cur_prompt);
4937 if (pktin->type == SSH1_SMSG_FAILURE) {
4938 if (flags & FLAG_VERBOSE)
4939 c_write_str(ssh, "Access denied\r\n");
4940 logevent("Authentication refused");
4941 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4942 bombout(("Strange packet received, type %d", pktin->type));
4948 if (s->publickey_blob) {
4949 sfree(s->publickey_blob);
4950 sfree(s->publickey_comment);
4953 logevent("Authentication successful");
4958 static void ssh_channel_try_eof(struct ssh_channel *c)
4961 assert(c->pending_eof); /* precondition for calling us */
4963 return; /* can't close: not even opened yet */
4964 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4965 return; /* can't send EOF: pending outgoing data */
4967 c->pending_eof = FALSE; /* we're about to send it */
4968 if (ssh->version == 1) {
4969 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4971 c->closes |= CLOSES_SENT_EOF;
4973 struct Packet *pktout;
4974 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4975 ssh2_pkt_adduint32(pktout, c->remoteid);
4976 ssh2_pkt_send(ssh, pktout);
4977 c->closes |= CLOSES_SENT_EOF;
4978 ssh2_channel_check_close(c);
4982 Conf *sshfwd_get_conf(struct ssh_channel *c)
4988 void sshfwd_write_eof(struct ssh_channel *c)
4992 if (ssh->state == SSH_STATE_CLOSED)
4995 if (c->closes & CLOSES_SENT_EOF)
4998 c->pending_eof = TRUE;
4999 ssh_channel_try_eof(c);
5002 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
5006 if (ssh->state == SSH_STATE_CLOSED)
5011 x11_close(c->u.x11.xconn);
5012 logeventf(ssh, "Forwarded X11 connection terminated due to local "
5016 pfd_close(c->u.pfd.pf);
5017 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
5020 c->type = CHAN_ZOMBIE;
5021 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5023 ssh2_channel_check_close(c);
5026 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5030 if (ssh->state == SSH_STATE_CLOSED)
5033 return ssh_send_channel_data(c, buf, len);
5036 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5040 if (ssh->state == SSH_STATE_CLOSED)
5043 ssh_channel_unthrottle(c, bufsize);
5046 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5048 struct queued_handler *qh = ssh->qhead;
5052 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5055 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5056 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5059 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5060 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5064 ssh->qhead = qh->next;
5066 if (ssh->qhead->msg1 > 0) {
5067 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5068 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5070 if (ssh->qhead->msg2 > 0) {
5071 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5072 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5075 ssh->qhead = ssh->qtail = NULL;
5078 qh->handler(ssh, pktin, qh->ctx);
5083 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5084 chandler_fn_t handler, void *ctx)
5086 struct queued_handler *qh;
5088 qh = snew(struct queued_handler);
5091 qh->handler = handler;
5095 if (ssh->qtail == NULL) {
5099 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5100 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5103 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5104 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5107 ssh->qtail->next = qh;
5112 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5114 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5116 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5117 SSH2_MSG_REQUEST_SUCCESS)) {
5118 logeventf(ssh, "Remote port forwarding from %s enabled",
5121 logeventf(ssh, "Remote port forwarding from %s refused",
5124 rpf = del234(ssh->rportfwds, pf);
5126 pf->pfrec->remote = NULL;
5131 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5134 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5137 pf->share_ctx = share_ctx;
5138 pf->shost = dupstr(shost);
5140 pf->sportdesc = NULL;
5141 if (!ssh->rportfwds) {
5142 assert(ssh->version == 2);
5143 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5145 if (add234(ssh->rportfwds, pf) != pf) {
5153 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5156 share_got_pkt_from_server(ctx, pktin->type,
5157 pktin->body, pktin->length);
5160 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5162 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5163 ssh_sharing_global_request_response, share_ctx);
5166 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5168 struct ssh_portfwd *epf;
5172 if (!ssh->portfwds) {
5173 ssh->portfwds = newtree234(ssh_portcmp);
5176 * Go through the existing port forwardings and tag them
5177 * with status==DESTROY. Any that we want to keep will be
5178 * re-enabled (status==KEEP) as we go through the
5179 * configuration and find out which bits are the same as
5182 struct ssh_portfwd *epf;
5184 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5185 epf->status = DESTROY;
5188 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5190 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5191 char *kp, *kp2, *vp, *vp2;
5192 char address_family, type;
5193 int sport,dport,sserv,dserv;
5194 char *sports, *dports, *saddr, *host;
5198 address_family = 'A';
5200 if (*kp == 'A' || *kp == '4' || *kp == '6')
5201 address_family = *kp++;
5202 if (*kp == 'L' || *kp == 'R')
5205 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5207 * There's a colon in the middle of the source port
5208 * string, which means that the part before it is
5209 * actually a source address.
5211 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5212 saddr = host_strduptrim(saddr_tmp);
5219 sport = atoi(sports);
5223 sport = net_service_lookup(sports);
5225 logeventf(ssh, "Service lookup failed for source"
5226 " port \"%s\"", sports);
5230 if (type == 'L' && !strcmp(val, "D")) {
5231 /* dynamic forwarding */
5238 /* ordinary forwarding */
5240 vp2 = vp + host_strcspn(vp, ":");
5241 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5245 dport = atoi(dports);
5249 dport = net_service_lookup(dports);
5251 logeventf(ssh, "Service lookup failed for destination"
5252 " port \"%s\"", dports);
5257 if (sport && dport) {
5258 /* Set up a description of the source port. */
5259 struct ssh_portfwd *pfrec, *epfrec;
5261 pfrec = snew(struct ssh_portfwd);
5263 pfrec->saddr = saddr;
5264 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5265 pfrec->sport = sport;
5266 pfrec->daddr = host;
5267 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5268 pfrec->dport = dport;
5269 pfrec->local = NULL;
5270 pfrec->remote = NULL;
5271 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5272 address_family == '6' ? ADDRTYPE_IPV6 :
5275 epfrec = add234(ssh->portfwds, pfrec);
5276 if (epfrec != pfrec) {
5277 if (epfrec->status == DESTROY) {
5279 * We already have a port forwarding up and running
5280 * with precisely these parameters. Hence, no need
5281 * to do anything; simply re-tag the existing one
5284 epfrec->status = KEEP;
5287 * Anything else indicates that there was a duplicate
5288 * in our input, which we'll silently ignore.
5290 free_portfwd(pfrec);
5292 pfrec->status = CREATE;
5301 * Now go through and destroy any port forwardings which were
5304 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5305 if (epf->status == DESTROY) {
5308 message = dupprintf("%s port forwarding from %s%s%d",
5309 epf->type == 'L' ? "local" :
5310 epf->type == 'R' ? "remote" : "dynamic",
5311 epf->saddr ? epf->saddr : "",
5312 epf->saddr ? ":" : "",
5315 if (epf->type != 'D') {
5316 char *msg2 = dupprintf("%s to %s:%d", message,
5317 epf->daddr, epf->dport);
5322 logeventf(ssh, "Cancelling %s", message);
5325 /* epf->remote or epf->local may be NULL if setting up a
5326 * forwarding failed. */
5328 struct ssh_rportfwd *rpf = epf->remote;
5329 struct Packet *pktout;
5332 * Cancel the port forwarding at the server
5335 if (ssh->version == 1) {
5337 * We cannot cancel listening ports on the
5338 * server side in SSH-1! There's no message
5339 * to support it. Instead, we simply remove
5340 * the rportfwd record from the local end
5341 * so that any connections the server tries
5342 * to make on it are rejected.
5345 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5346 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5347 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5349 ssh2_pkt_addstring(pktout, epf->saddr);
5350 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5351 /* XXX: rport_acceptall may not represent
5352 * what was used to open the original connection,
5353 * since it's reconfigurable. */
5354 ssh2_pkt_addstring(pktout, "");
5356 ssh2_pkt_addstring(pktout, "localhost");
5358 ssh2_pkt_adduint32(pktout, epf->sport);
5359 ssh2_pkt_send(ssh, pktout);
5362 del234(ssh->rportfwds, rpf);
5364 } else if (epf->local) {
5365 pfl_terminate(epf->local);
5368 delpos234(ssh->portfwds, i);
5370 i--; /* so we don't skip one in the list */
5374 * And finally, set up any new port forwardings (status==CREATE).
5376 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5377 if (epf->status == CREATE) {
5378 char *sportdesc, *dportdesc;
5379 sportdesc = dupprintf("%s%s%s%s%d%s",
5380 epf->saddr ? epf->saddr : "",
5381 epf->saddr ? ":" : "",
5382 epf->sserv ? epf->sserv : "",
5383 epf->sserv ? "(" : "",
5385 epf->sserv ? ")" : "");
5386 if (epf->type == 'D') {
5389 dportdesc = dupprintf("%s:%s%s%d%s",
5391 epf->dserv ? epf->dserv : "",
5392 epf->dserv ? "(" : "",
5394 epf->dserv ? ")" : "");
5397 if (epf->type == 'L') {
5398 char *err = pfl_listen(epf->daddr, epf->dport,
5399 epf->saddr, epf->sport,
5400 ssh, conf, &epf->local,
5401 epf->addressfamily);
5403 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5404 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5405 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5406 sportdesc, dportdesc,
5407 err ? " failed: " : "", err ? err : "");
5410 } else if (epf->type == 'D') {
5411 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5412 ssh, conf, &epf->local,
5413 epf->addressfamily);
5415 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5416 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5417 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5419 err ? " failed: " : "", err ? err : "");
5424 struct ssh_rportfwd *pf;
5427 * Ensure the remote port forwardings tree exists.
5429 if (!ssh->rportfwds) {
5430 if (ssh->version == 1)
5431 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5433 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5436 pf = snew(struct ssh_rportfwd);
5437 pf->share_ctx = NULL;
5438 pf->dhost = dupstr(epf->daddr);
5439 pf->dport = epf->dport;
5441 pf->shost = dupstr(epf->saddr);
5442 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5443 pf->shost = dupstr("");
5445 pf->shost = dupstr("localhost");
5447 pf->sport = epf->sport;
5448 if (add234(ssh->rportfwds, pf) != pf) {
5449 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5450 epf->daddr, epf->dport);
5453 logeventf(ssh, "Requesting remote port %s"
5454 " forward to %s", sportdesc, dportdesc);
5456 pf->sportdesc = sportdesc;
5461 if (ssh->version == 1) {
5462 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5463 PKT_INT, epf->sport,
5464 PKT_STR, epf->daddr,
5465 PKT_INT, epf->dport,
5467 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5469 ssh_rportfwd_succfail, pf);
5471 struct Packet *pktout;
5472 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5473 ssh2_pkt_addstring(pktout, "tcpip-forward");
5474 ssh2_pkt_addbool(pktout, 1);/* want reply */
5475 ssh2_pkt_addstring(pktout, pf->shost);
5476 ssh2_pkt_adduint32(pktout, pf->sport);
5477 ssh2_pkt_send(ssh, pktout);
5479 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5480 SSH2_MSG_REQUEST_FAILURE,
5481 ssh_rportfwd_succfail, pf);
5490 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5493 int stringlen, bufsize;
5495 ssh_pkt_getstring(pktin, &string, &stringlen);
5496 if (string == NULL) {
5497 bombout(("Incoming terminal data packet was badly formed"));
5501 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5503 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5504 ssh->v1_stdout_throttling = 1;
5505 ssh_throttle_conn(ssh, +1);
5509 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5511 /* Remote side is trying to open a channel to talk to our
5512 * X-Server. Give them back a local channel number. */
5513 struct ssh_channel *c;
5514 int remoteid = ssh_pkt_getuint32(pktin);
5516 logevent("Received X11 connect request");
5517 /* Refuse if X11 forwarding is disabled. */
5518 if (!ssh->X11_fwd_enabled) {
5519 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5520 PKT_INT, remoteid, PKT_END);
5521 logevent("Rejected X11 connect request");
5523 c = snew(struct ssh_channel);
5526 ssh_channel_init(c);
5527 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5528 c->remoteid = remoteid;
5529 c->halfopen = FALSE;
5530 c->type = CHAN_X11; /* identify channel type */
5531 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5532 PKT_INT, c->remoteid, PKT_INT,
5533 c->localid, PKT_END);
5534 logevent("Opened X11 forward channel");
5538 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5540 /* Remote side is trying to open a channel to talk to our
5541 * agent. Give them back a local channel number. */
5542 struct ssh_channel *c;
5543 int remoteid = ssh_pkt_getuint32(pktin);
5545 /* Refuse if agent forwarding is disabled. */
5546 if (!ssh->agentfwd_enabled) {
5547 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5548 PKT_INT, remoteid, PKT_END);
5550 c = snew(struct ssh_channel);
5552 ssh_channel_init(c);
5553 c->remoteid = remoteid;
5554 c->halfopen = FALSE;
5555 c->type = CHAN_AGENT; /* identify channel type */
5556 c->u.a.lensofar = 0;
5557 c->u.a.message = NULL;
5558 c->u.a.outstanding_requests = 0;
5559 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5560 PKT_INT, c->remoteid, PKT_INT, c->localid,
5565 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5567 /* Remote side is trying to open a channel to talk to a
5568 * forwarded port. Give them back a local channel number. */
5569 struct ssh_rportfwd pf, *pfp;
5575 remoteid = ssh_pkt_getuint32(pktin);
5576 ssh_pkt_getstring(pktin, &host, &hostsize);
5577 port = ssh_pkt_getuint32(pktin);
5579 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5581 pfp = find234(ssh->rportfwds, &pf, NULL);
5584 logeventf(ssh, "Rejected remote port open request for %s:%d",
5586 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5587 PKT_INT, remoteid, PKT_END);
5589 struct ssh_channel *c = snew(struct ssh_channel);
5592 logeventf(ssh, "Received remote port open request for %s:%d",
5594 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5595 c, ssh->conf, pfp->pfrec->addressfamily);
5597 logeventf(ssh, "Port open failed: %s", err);
5600 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5601 PKT_INT, remoteid, PKT_END);
5603 ssh_channel_init(c);
5604 c->remoteid = remoteid;
5605 c->halfopen = FALSE;
5606 c->type = CHAN_SOCKDATA; /* identify channel type */
5607 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5608 PKT_INT, c->remoteid, PKT_INT,
5609 c->localid, PKT_END);
5610 logevent("Forwarded port opened successfully");
5617 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5619 struct ssh_channel *c;
5621 c = ssh_channel_msg(ssh, pktin);
5622 if (c && c->type == CHAN_SOCKDATA) {
5623 c->remoteid = ssh_pkt_getuint32(pktin);
5624 c->halfopen = FALSE;
5625 c->throttling_conn = 0;
5626 pfd_confirm(c->u.pfd.pf);
5629 if (c && c->pending_eof) {
5631 * We have a pending close on this channel,
5632 * which we decided on before the server acked
5633 * the channel open. So now we know the
5634 * remoteid, we can close it again.
5636 ssh_channel_try_eof(c);
5640 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5642 struct ssh_channel *c;
5644 c = ssh_channel_msg(ssh, pktin);
5645 if (c && c->type == CHAN_SOCKDATA) {
5646 logevent("Forwarded connection refused by server");
5647 pfd_close(c->u.pfd.pf);
5648 del234(ssh->channels, c);
5653 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5655 /* Remote side closes a channel. */
5656 struct ssh_channel *c;
5658 c = ssh_channel_msg(ssh, pktin);
5661 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE) {
5663 * Received CHANNEL_CLOSE, which we translate into
5666 ssh_channel_got_eof(c);
5669 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5670 !(c->closes & CLOSES_RCVD_CLOSE)) {
5672 if (!(c->closes & CLOSES_SENT_EOF)) {
5673 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %u"
5674 " for which we never sent CHANNEL_CLOSE\n",
5678 c->closes |= CLOSES_RCVD_CLOSE;
5681 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5682 !(c->closes & CLOSES_SENT_CLOSE)) {
5683 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5684 PKT_INT, c->remoteid, PKT_END);
5685 c->closes |= CLOSES_SENT_CLOSE;
5688 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5689 ssh_channel_destroy(c);
5694 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5696 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5699 while (length > 0) {
5700 if (c->u.a.lensofar < 4) {
5701 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)length);
5702 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
5705 c->u.a.lensofar += l;
5707 if (c->u.a.lensofar == 4) {
5708 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
5709 c->u.a.message = snewn(c->u.a.totallen, unsigned char);
5710 memcpy(c->u.a.message, c->u.a.msglen, 4);
5712 if (c->u.a.lensofar >= 4 && length > 0) {
5713 unsigned int l = min(c->u.a.totallen - c->u.a.lensofar,
5715 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
5718 c->u.a.lensofar += l;
5720 if (c->u.a.lensofar == c->u.a.totallen) {
5723 c->u.a.outstanding_requests++;
5724 if (agent_query(c->u.a.message, c->u.a.totallen, &reply, &replylen,
5725 ssh_agentf_callback, c))
5726 ssh_agentf_callback(c, reply, replylen);
5727 sfree(c->u.a.message);
5728 c->u.a.message = NULL;
5729 c->u.a.lensofar = 0;
5732 return 0; /* agent channels never back up */
5735 static int ssh_channel_data(struct ssh_channel *c, int is_stderr,
5736 char *data, int length)
5739 case CHAN_MAINSESSION:
5740 return from_backend(c->ssh->frontend, is_stderr, data, length);
5742 return x11_send(c->u.x11.xconn, data, length);
5744 return pfd_send(c->u.pfd.pf, data, length);
5746 return ssh_agent_channel_data(c, data, length);
5751 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5753 /* Data sent down one of our channels. */
5756 struct ssh_channel *c;
5758 c = ssh_channel_msg(ssh, pktin);
5759 ssh_pkt_getstring(pktin, &p, &len);
5762 int bufsize = ssh_channel_data(c, FALSE, p, len);
5763 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5764 c->throttling_conn = 1;
5765 ssh_throttle_conn(ssh, +1);
5770 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5772 ssh->exitcode = ssh_pkt_getuint32(pktin);
5773 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5774 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5776 * In case `helpful' firewalls or proxies tack
5777 * extra human-readable text on the end of the
5778 * session which we might mistake for another
5779 * encrypted packet, we close the session once
5780 * we've sent EXIT_CONFIRMATION.
5782 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5785 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5786 static void ssh1_send_ttymode(void *data,
5787 const struct ssh_ttymode *mode, char *val)
5789 struct Packet *pktout = (struct Packet *)data;
5790 unsigned int arg = 0;
5792 switch (mode->type) {
5794 arg = ssh_tty_parse_specchar(val);
5797 arg = ssh_tty_parse_boolean(val);
5800 ssh2_pkt_addbyte(pktout, mode->opcode);
5801 ssh2_pkt_addbyte(pktout, arg);
5804 int ssh_agent_forwarding_permitted(Ssh ssh)
5806 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5809 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5810 struct Packet *pktin)
5812 crBegin(ssh->do_ssh1_connection_crstate);
5814 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5815 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5816 ssh1_smsg_stdout_stderr_data;
5818 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5819 ssh1_msg_channel_open_confirmation;
5820 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5821 ssh1_msg_channel_open_failure;
5822 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5823 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5824 ssh1_msg_channel_close;
5825 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5826 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5828 if (ssh_agent_forwarding_permitted(ssh)) {
5829 logevent("Requesting agent forwarding");
5830 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5834 if (pktin->type != SSH1_SMSG_SUCCESS
5835 && pktin->type != SSH1_SMSG_FAILURE) {
5836 bombout(("Protocol confusion"));
5838 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5839 logevent("Agent forwarding refused");
5841 logevent("Agent forwarding enabled");
5842 ssh->agentfwd_enabled = TRUE;
5843 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5847 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5849 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5851 if (!ssh->x11disp) {
5852 /* FIXME: return an error message from x11_setup_display */
5853 logevent("X11 forwarding not enabled: unable to"
5854 " initialise X display");
5856 ssh->x11auth = x11_invent_fake_auth
5857 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5858 ssh->x11auth->disp = ssh->x11disp;
5860 logevent("Requesting X11 forwarding");
5861 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5862 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5863 PKT_STR, ssh->x11auth->protoname,
5864 PKT_STR, ssh->x11auth->datastring,
5865 PKT_INT, ssh->x11disp->screennum,
5868 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5869 PKT_STR, ssh->x11auth->protoname,
5870 PKT_STR, ssh->x11auth->datastring,
5876 if (pktin->type != SSH1_SMSG_SUCCESS
5877 && pktin->type != SSH1_SMSG_FAILURE) {
5878 bombout(("Protocol confusion"));
5880 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5881 logevent("X11 forwarding refused");
5883 logevent("X11 forwarding enabled");
5884 ssh->X11_fwd_enabled = TRUE;
5885 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5890 ssh_setup_portfwd(ssh, ssh->conf);
5891 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5893 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5895 /* Unpick the terminal-speed string. */
5896 /* XXX perhaps we should allow no speeds to be sent. */
5897 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5898 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5899 /* Send the pty request. */
5900 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5901 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5902 ssh_pkt_adduint32(pkt, ssh->term_height);
5903 ssh_pkt_adduint32(pkt, ssh->term_width);
5904 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5905 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5906 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5907 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5908 ssh_pkt_adduint32(pkt, ssh->ispeed);
5909 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5910 ssh_pkt_adduint32(pkt, ssh->ospeed);
5911 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5913 ssh->state = SSH_STATE_INTERMED;
5917 if (pktin->type != SSH1_SMSG_SUCCESS
5918 && pktin->type != SSH1_SMSG_FAILURE) {
5919 bombout(("Protocol confusion"));
5921 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5922 c_write_str(ssh, "Server refused to allocate pty\r\n");
5923 ssh->editing = ssh->echoing = 1;
5925 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5926 ssh->ospeed, ssh->ispeed);
5927 ssh->got_pty = TRUE;
5930 ssh->editing = ssh->echoing = 1;
5933 if (conf_get_int(ssh->conf, CONF_compression)) {
5934 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5938 if (pktin->type != SSH1_SMSG_SUCCESS
5939 && pktin->type != SSH1_SMSG_FAILURE) {
5940 bombout(("Protocol confusion"));
5942 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5943 c_write_str(ssh, "Server refused to compress\r\n");
5945 logevent("Started compression");
5946 ssh->v1_compressing = TRUE;
5947 ssh->cs_comp_ctx = zlib_compress_init();
5948 logevent("Initialised zlib (RFC1950) compression");
5949 ssh->sc_comp_ctx = zlib_decompress_init();
5950 logevent("Initialised zlib (RFC1950) decompression");
5954 * Start the shell or command.
5956 * Special case: if the first-choice command is an SSH-2
5957 * subsystem (hence not usable here) and the second choice
5958 * exists, we fall straight back to that.
5961 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5963 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5964 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5965 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5966 ssh->fallback_cmd = TRUE;
5969 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5971 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5972 logevent("Started session");
5975 ssh->state = SSH_STATE_SESSION;
5976 if (ssh->size_needed)
5977 ssh_size(ssh, ssh->term_width, ssh->term_height);
5978 if (ssh->eof_needed)
5979 ssh_special(ssh, TS_EOF);
5982 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5984 ssh->channels = newtree234(ssh_channelcmp);
5988 * By this point, most incoming packets are already being
5989 * handled by the dispatch table, and we need only pay
5990 * attention to the unusual ones.
5995 if (pktin->type == SSH1_SMSG_SUCCESS) {
5996 /* may be from EXEC_SHELL on some servers */
5997 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5998 /* may be from EXEC_SHELL on some servers
5999 * if no pty is available or in other odd cases. Ignore */
6001 bombout(("Strange packet received: type %d", pktin->type));
6006 int len = min(inlen, 512);
6007 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6008 PKT_INT, len, PKT_DATA, in, len,
6020 * Handle the top-level SSH-2 protocol.
6022 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6027 ssh_pkt_getstring(pktin, &msg, &msglen);
6028 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6031 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6033 /* log reason code in disconnect message */
6037 ssh_pkt_getstring(pktin, &msg, &msglen);
6038 bombout(("Server sent disconnect message:\n\"%.*s\"",
6039 msglen, NULLTOEMPTY(msg)));
6042 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6044 /* Do nothing, because we're ignoring it! Duhh. */
6047 static void ssh1_protocol_setup(Ssh ssh)
6052 * Most messages are handled by the coroutines.
6054 for (i = 0; i < 256; i++)
6055 ssh->packet_dispatch[i] = NULL;
6058 * These special message types we install handlers for.
6060 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6061 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6062 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6065 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6066 struct Packet *pktin)
6068 const unsigned char *in = (const unsigned char *)vin;
6069 if (ssh->state == SSH_STATE_CLOSED)
6072 if (pktin && ssh->packet_dispatch[pktin->type]) {
6073 ssh->packet_dispatch[pktin->type](ssh, pktin);
6077 if (!ssh->protocol_initial_phase_done) {
6078 if (do_ssh1_login(ssh, in, inlen, pktin))
6079 ssh->protocol_initial_phase_done = TRUE;
6084 do_ssh1_connection(ssh, in, inlen, pktin);
6088 * Utility routines for decoding comma-separated strings in KEXINIT.
6090 static int first_in_commasep_string(char const *needle, char const *haystack,
6094 if (!needle || !haystack) /* protect against null pointers */
6096 needlen = strlen(needle);
6098 if (haylen >= needlen && /* haystack is long enough */
6099 !memcmp(needle, haystack, needlen) && /* initial match */
6100 (haylen == needlen || haystack[needlen] == ',')
6101 /* either , or EOS follows */
6107 static int in_commasep_string(char const *needle, char const *haystack,
6112 if (!needle || !haystack) /* protect against null pointers */
6115 * Is it at the start of the string?
6117 if (first_in_commasep_string(needle, haystack, haylen))
6120 * If not, search for the next comma and resume after that.
6121 * If no comma found, terminate.
6123 p = memchr(haystack, ',', haylen);
6125 /* + 1 to skip over comma */
6126 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6130 * Add a value to the comma-separated string at the end of the packet.
6132 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6134 if (pkt->length - pkt->savedpos > 0)
6135 ssh_pkt_addstring_str(pkt, ",");
6136 ssh_pkt_addstring_str(pkt, data);
6141 * SSH-2 key derivation (RFC 4253 section 7.2).
6143 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6144 char chr, int keylen)
6146 const struct ssh_hash *h = ssh->kex->hash;
6154 /* Round up to the next multiple of hash length. */
6155 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6157 key = snewn(keylen_padded, unsigned char);
6159 /* First hlen bytes. */
6161 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6162 hash_mpint(h, s, K);
6163 h->bytes(s, H, h->hlen);
6164 h->bytes(s, &chr, 1);
6165 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6168 /* Subsequent blocks of hlen bytes. */
6169 if (keylen_padded > h->hlen) {
6173 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6174 hash_mpint(h, s, K);
6175 h->bytes(s, H, h->hlen);
6177 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6178 h->bytes(s, key + offset - h->hlen, h->hlen);
6180 h->final(s2, key + offset);
6186 /* Now clear any extra bytes of key material beyond the length
6187 * we're officially returning, because the caller won't know to
6189 if (keylen_padded > keylen)
6190 smemclr(key + keylen, keylen_padded - keylen);
6196 * Structure for constructing KEXINIT algorithm lists.
6198 #define MAXKEXLIST 16
6199 struct kexinit_algorithm {
6203 const struct ssh_kex *kex;
6207 const struct ssh_signkey *hostkey;
6211 const struct ssh2_cipher *cipher;
6215 const struct ssh_mac *mac;
6218 const struct ssh_compress *comp;
6223 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6224 * If the algorithm is already in the list, return a pointer to its
6225 * entry, otherwise return an entry from the end of the list.
6226 * This assumes that every time a particular name is passed in, it
6227 * comes from the same string constant. If this isn't true, this
6228 * function may need to be rewritten to use strcmp() instead.
6230 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6231 *list, const char *name)
6235 for (i = 0; i < MAXKEXLIST; i++)
6236 if (list[i].name == NULL || list[i].name == name) {
6237 list[i].name = name;
6240 assert(!"No space in KEXINIT list");
6245 * Handle the SSH-2 transport layer.
6247 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6248 struct Packet *pktin)
6250 const unsigned char *in = (const unsigned char *)vin;
6252 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6253 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6256 const char * kexlist_descr[NKEXLIST] = {
6257 "key exchange algorithm", "host key algorithm",
6258 "client-to-server cipher", "server-to-client cipher",
6259 "client-to-server MAC", "server-to-client MAC",
6260 "client-to-server compression method",
6261 "server-to-client compression method" };
6262 struct do_ssh2_transport_state {
6264 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6265 Bignum p, g, e, f, K;
6268 int kex_init_value, kex_reply_value;
6269 const struct ssh_mac *const *maclist;
6271 const struct ssh2_cipher *cscipher_tobe;
6272 const struct ssh2_cipher *sccipher_tobe;
6273 const struct ssh_mac *csmac_tobe;
6274 const struct ssh_mac *scmac_tobe;
6275 int csmac_etm_tobe, scmac_etm_tobe;
6276 const struct ssh_compress *cscomp_tobe;
6277 const struct ssh_compress *sccomp_tobe;
6278 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6279 int hostkeylen, siglen, rsakeylen;
6280 void *hkey; /* actual host key */
6281 void *rsakey; /* for RSA kex */
6282 void *eckey; /* for ECDH kex */
6283 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6284 int n_preferred_kex;
6285 const struct ssh_kexes *preferred_kex[KEX_MAX];
6287 int preferred_hk[HK_MAX];
6288 int n_preferred_ciphers;
6289 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6290 const struct ssh_compress *preferred_comp;
6291 int userauth_succeeded; /* for delayed compression */
6292 int pending_compression;
6293 int got_session_id, activated_authconn;
6294 struct Packet *pktout;
6298 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6300 crState(do_ssh2_transport_state);
6302 assert(!ssh->bare_connection);
6303 assert(ssh->version == 2);
6307 s->cscipher_tobe = s->sccipher_tobe = NULL;
6308 s->csmac_tobe = s->scmac_tobe = NULL;
6309 s->cscomp_tobe = s->sccomp_tobe = NULL;
6311 s->got_session_id = s->activated_authconn = FALSE;
6312 s->userauth_succeeded = FALSE;
6313 s->pending_compression = FALSE;
6316 * Be prepared to work around the buggy MAC problem.
6318 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6319 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6321 s->maclist = macs, s->nmacs = lenof(macs);
6324 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6327 struct kexinit_algorithm *alg;
6330 * Set up the preferred key exchange. (NULL => warn below here)
6332 s->n_preferred_kex = 0;
6333 for (i = 0; i < KEX_MAX; i++) {
6334 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6336 s->preferred_kex[s->n_preferred_kex++] =
6337 &ssh_diffiehellman_gex;
6340 s->preferred_kex[s->n_preferred_kex++] =
6341 &ssh_diffiehellman_group14;
6344 s->preferred_kex[s->n_preferred_kex++] =
6345 &ssh_diffiehellman_group1;
6348 s->preferred_kex[s->n_preferred_kex++] =
6352 s->preferred_kex[s->n_preferred_kex++] =
6356 /* Flag for later. Don't bother if it's the last in
6358 if (i < KEX_MAX - 1) {
6359 s->preferred_kex[s->n_preferred_kex++] = NULL;
6366 * Set up the preferred host key types. These are just the ids
6367 * in the enum in putty.h, so 'warn below here' is indicated
6370 s->n_preferred_hk = 0;
6371 for (i = 0; i < HK_MAX; i++) {
6372 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6373 /* As above, don't bother with HK_WARN if it's last in the
6375 if (id != HK_WARN || i < HK_MAX - 1)
6376 s->preferred_hk[s->n_preferred_hk++] = id;
6380 * Set up the preferred ciphers. (NULL => warn below here)
6382 s->n_preferred_ciphers = 0;
6383 for (i = 0; i < CIPHER_MAX; i++) {
6384 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6385 case CIPHER_BLOWFISH:
6386 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6389 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6390 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6394 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6397 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6399 case CIPHER_ARCFOUR:
6400 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6402 case CIPHER_CHACHA20:
6403 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6406 /* Flag for later. Don't bother if it's the last in
6408 if (i < CIPHER_MAX - 1) {
6409 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6416 * Set up preferred compression.
6418 if (conf_get_int(ssh->conf, CONF_compression))
6419 s->preferred_comp = &ssh_zlib;
6421 s->preferred_comp = &ssh_comp_none;
6424 * Enable queueing of outgoing auth- or connection-layer
6425 * packets while we are in the middle of a key exchange.
6427 ssh->queueing = TRUE;
6430 * Flag that KEX is in progress.
6432 ssh->kex_in_progress = TRUE;
6434 for (i = 0; i < NKEXLIST; i++)
6435 for (j = 0; j < MAXKEXLIST; j++)
6436 s->kexlists[i][j].name = NULL;
6437 /* List key exchange algorithms. */
6439 for (i = 0; i < s->n_preferred_kex; i++) {
6440 const struct ssh_kexes *k = s->preferred_kex[i];
6441 if (!k) warn = TRUE;
6442 else for (j = 0; j < k->nkexes; j++) {
6443 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6445 alg->u.kex.kex = k->list[j];
6446 alg->u.kex.warn = warn;
6449 /* List server host key algorithms. */
6450 if (!s->got_session_id) {
6452 * In the first key exchange, we list all the algorithms
6453 * we're prepared to cope with, but prefer those algorithms
6454 * for which we have a host key for this host.
6456 * If the host key algorithm is below the warning
6457 * threshold, we warn even if we did already have a key
6458 * for it, on the basis that if the user has just
6459 * reconfigured that host key type to be warned about,
6460 * they surely _do_ want to be alerted that a server
6461 * they're actually connecting to is using it.
6464 for (i = 0; i < s->n_preferred_hk; i++) {
6465 if (s->preferred_hk[i] == HK_WARN)
6467 for (j = 0; j < lenof(hostkey_algs); j++) {
6468 if (hostkey_algs[j].id != s->preferred_hk[i])
6470 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6471 hostkey_algs[j].alg->keytype)) {
6472 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6473 hostkey_algs[j].alg->name);
6474 alg->u.hk.hostkey = hostkey_algs[j].alg;
6475 alg->u.hk.warn = warn;
6480 for (i = 0; i < s->n_preferred_hk; i++) {
6481 if (s->preferred_hk[i] == HK_WARN)
6483 for (j = 0; j < lenof(hostkey_algs); j++) {
6484 if (hostkey_algs[j].id != s->preferred_hk[i])
6486 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6487 hostkey_algs[j].alg->name);
6488 alg->u.hk.hostkey = hostkey_algs[j].alg;
6489 alg->u.hk.warn = warn;
6494 * In subsequent key exchanges, we list only the kex
6495 * algorithm that was selected in the first key exchange,
6496 * so that we keep getting the same host key and hence
6497 * don't have to interrupt the user's session to ask for
6501 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6502 ssh->hostkey->name);
6503 alg->u.hk.hostkey = ssh->hostkey;
6504 alg->u.hk.warn = FALSE;
6506 /* List encryption algorithms (client->server then server->client). */
6507 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6510 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6511 alg->u.cipher.cipher = NULL;
6512 alg->u.cipher.warn = warn;
6513 #endif /* FUZZING */
6514 for (i = 0; i < s->n_preferred_ciphers; i++) {
6515 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6516 if (!c) warn = TRUE;
6517 else for (j = 0; j < c->nciphers; j++) {
6518 alg = ssh2_kexinit_addalg(s->kexlists[k],
6520 alg->u.cipher.cipher = c->list[j];
6521 alg->u.cipher.warn = warn;
6525 /* List MAC algorithms (client->server then server->client). */
6526 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6528 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6529 alg->u.mac.mac = NULL;
6530 alg->u.mac.etm = FALSE;
6531 #endif /* FUZZING */
6532 for (i = 0; i < s->nmacs; i++) {
6533 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6534 alg->u.mac.mac = s->maclist[i];
6535 alg->u.mac.etm = FALSE;
6537 for (i = 0; i < s->nmacs; i++)
6538 /* For each MAC, there may also be an ETM version,
6539 * which we list second. */
6540 if (s->maclist[i]->etm_name) {
6541 alg = ssh2_kexinit_addalg(s->kexlists[j],
6542 s->maclist[i]->etm_name);
6543 alg->u.mac.mac = s->maclist[i];
6544 alg->u.mac.etm = TRUE;
6547 /* List client->server compression algorithms,
6548 * then server->client compression algorithms. (We use the
6549 * same set twice.) */
6550 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6551 assert(lenof(compressions) > 1);
6552 /* Prefer non-delayed versions */
6553 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6554 alg->u.comp = s->preferred_comp;
6555 /* We don't even list delayed versions of algorithms until
6556 * they're allowed to be used, to avoid a race. See the end of
6558 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6559 alg = ssh2_kexinit_addalg(s->kexlists[j],
6560 s->preferred_comp->delayed_name);
6561 alg->u.comp = s->preferred_comp;
6563 for (i = 0; i < lenof(compressions); i++) {
6564 const struct ssh_compress *c = compressions[i];
6565 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6567 if (s->userauth_succeeded && c->delayed_name) {
6568 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6574 * Construct and send our key exchange packet.
6576 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6577 for (i = 0; i < 16; i++)
6578 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6579 for (i = 0; i < NKEXLIST; i++) {
6580 ssh2_pkt_addstring_start(s->pktout);
6581 for (j = 0; j < MAXKEXLIST; j++) {
6582 if (s->kexlists[i][j].name == NULL) break;
6583 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6586 /* List client->server languages. Empty list. */
6587 ssh2_pkt_addstring_start(s->pktout);
6588 /* List server->client languages. Empty list. */
6589 ssh2_pkt_addstring_start(s->pktout);
6590 /* First KEX packet does _not_ follow, because we're not that brave. */
6591 ssh2_pkt_addbool(s->pktout, FALSE);
6593 ssh2_pkt_adduint32(s->pktout, 0);
6596 s->our_kexinitlen = s->pktout->length - 5;
6597 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6598 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6600 ssh2_pkt_send_noqueue(ssh, s->pktout);
6603 crWaitUntilV(pktin);
6606 * Now examine the other side's KEXINIT to see what we're up
6613 if (pktin->type != SSH2_MSG_KEXINIT) {
6614 bombout(("expected key exchange packet from server"));
6618 ssh->hostkey = NULL;
6619 s->cscipher_tobe = NULL;
6620 s->sccipher_tobe = NULL;
6621 s->csmac_tobe = NULL;
6622 s->scmac_tobe = NULL;
6623 s->cscomp_tobe = NULL;
6624 s->sccomp_tobe = NULL;
6625 s->warn_kex = s->warn_hk = FALSE;
6626 s->warn_cscipher = s->warn_sccipher = FALSE;
6628 pktin->savedpos += 16; /* skip garbage cookie */
6631 for (i = 0; i < NKEXLIST; i++) {
6632 ssh_pkt_getstring(pktin, &str, &len);
6634 bombout(("KEXINIT packet was incomplete"));
6638 /* If we've already selected a cipher which requires a
6639 * particular MAC, then just select that, and don't even
6640 * bother looking through the server's KEXINIT string for
6642 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6643 s->cscipher_tobe->required_mac) {
6644 s->csmac_tobe = s->cscipher_tobe->required_mac;
6645 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6648 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6649 s->sccipher_tobe->required_mac) {
6650 s->scmac_tobe = s->sccipher_tobe->required_mac;
6651 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6655 for (j = 0; j < MAXKEXLIST; j++) {
6656 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6657 if (alg->name == NULL) break;
6658 if (in_commasep_string(alg->name, str, len)) {
6659 /* We've found a matching algorithm. */
6660 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6661 /* Check if we might need to ignore first kex pkt */
6663 !first_in_commasep_string(alg->name, str, len))
6666 if (i == KEXLIST_KEX) {
6667 ssh->kex = alg->u.kex.kex;
6668 s->warn_kex = alg->u.kex.warn;
6669 } else if (i == KEXLIST_HOSTKEY) {
6670 ssh->hostkey = alg->u.hk.hostkey;
6671 s->warn_hk = alg->u.hk.warn;
6672 } else if (i == KEXLIST_CSCIPHER) {
6673 s->cscipher_tobe = alg->u.cipher.cipher;
6674 s->warn_cscipher = alg->u.cipher.warn;
6675 } else if (i == KEXLIST_SCCIPHER) {
6676 s->sccipher_tobe = alg->u.cipher.cipher;
6677 s->warn_sccipher = alg->u.cipher.warn;
6678 } else if (i == KEXLIST_CSMAC) {
6679 s->csmac_tobe = alg->u.mac.mac;
6680 s->csmac_etm_tobe = alg->u.mac.etm;
6681 } else if (i == KEXLIST_SCMAC) {
6682 s->scmac_tobe = alg->u.mac.mac;
6683 s->scmac_etm_tobe = alg->u.mac.etm;
6684 } else if (i == KEXLIST_CSCOMP) {
6685 s->cscomp_tobe = alg->u.comp;
6686 } else if (i == KEXLIST_SCCOMP) {
6687 s->sccomp_tobe = alg->u.comp;
6691 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6692 in_commasep_string(alg->u.comp->delayed_name, str, len))
6693 s->pending_compression = TRUE; /* try this later */
6695 bombout(("Couldn't agree a %s (available: %.*s)",
6696 kexlist_descr[i], len, str));
6700 if (i == KEXLIST_HOSTKEY) {
6704 * In addition to deciding which host key we're
6705 * actually going to use, we should make a list of the
6706 * host keys offered by the server which we _don't_
6707 * have cached. These will be offered as cross-
6708 * certification options by ssh_get_specials.
6710 * We also count the key we're currently using for KEX
6711 * as one we've already got, because by the time this
6712 * menu becomes visible, it will be.
6714 ssh->n_uncert_hostkeys = 0;
6716 for (j = 0; j < lenof(hostkey_algs); j++) {
6717 if (hostkey_algs[j].alg != ssh->hostkey &&
6718 in_commasep_string(hostkey_algs[j].alg->name,
6720 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6721 hostkey_algs[j].alg->keytype)) {
6722 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6728 if (s->pending_compression) {
6729 logevent("Server supports delayed compression; "
6730 "will try this later");
6732 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6733 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6734 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6736 ssh->exhash = ssh->kex->hash->init();
6737 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6738 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6739 hash_string(ssh->kex->hash, ssh->exhash,
6740 s->our_kexinit, s->our_kexinitlen);
6741 sfree(s->our_kexinit);
6742 /* Include the type byte in the hash of server's KEXINIT */
6743 hash_string(ssh->kex->hash, ssh->exhash,
6744 pktin->body - 1, pktin->length + 1);
6747 ssh_set_frozen(ssh, 1);
6748 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6750 ssh_dialog_callback, ssh);
6751 if (s->dlgret < 0) {
6755 bombout(("Unexpected data from server while"
6756 " waiting for user response"));
6759 } while (pktin || inlen > 0);
6760 s->dlgret = ssh->user_response;
6762 ssh_set_frozen(ssh, 0);
6763 if (s->dlgret == 0) {
6764 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6774 ssh_set_frozen(ssh, 1);
6777 * Change warning box wording depending on why we chose a
6778 * warning-level host key algorithm. If it's because
6779 * that's all we have *cached*, use the askhk mechanism,
6780 * and list the host keys we could usefully cross-certify.
6781 * Otherwise, use askalg for the standard wording.
6784 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6785 const struct ssh_signkey_with_user_pref_id *hktype =
6786 &hostkey_algs[ssh->uncert_hostkeys[j]];
6788 for (k = 0; k < HK_MAX; k++) {
6789 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6790 if (id == HK_WARN) {
6792 } else if (id == hktype->id) {
6799 char *old_ba = betteralgs;
6800 betteralgs = dupcat(betteralgs, ",",
6802 (const char *)NULL);
6805 betteralgs = dupstr(hktype->alg->name);
6810 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6811 betteralgs, ssh_dialog_callback, ssh);
6814 s->dlgret = askalg(ssh->frontend, "host key type",
6816 ssh_dialog_callback, ssh);
6818 if (s->dlgret < 0) {
6822 bombout(("Unexpected data from server while"
6823 " waiting for user response"));
6826 } while (pktin || inlen > 0);
6827 s->dlgret = ssh->user_response;
6829 ssh_set_frozen(ssh, 0);
6830 if (s->dlgret == 0) {
6831 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6837 if (s->warn_cscipher) {
6838 ssh_set_frozen(ssh, 1);
6839 s->dlgret = askalg(ssh->frontend,
6840 "client-to-server cipher",
6841 s->cscipher_tobe->name,
6842 ssh_dialog_callback, ssh);
6843 if (s->dlgret < 0) {
6847 bombout(("Unexpected data from server while"
6848 " waiting for user response"));
6851 } while (pktin || inlen > 0);
6852 s->dlgret = ssh->user_response;
6854 ssh_set_frozen(ssh, 0);
6855 if (s->dlgret == 0) {
6856 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6862 if (s->warn_sccipher) {
6863 ssh_set_frozen(ssh, 1);
6864 s->dlgret = askalg(ssh->frontend,
6865 "server-to-client cipher",
6866 s->sccipher_tobe->name,
6867 ssh_dialog_callback, ssh);
6868 if (s->dlgret < 0) {
6872 bombout(("Unexpected data from server while"
6873 " waiting for user response"));
6876 } while (pktin || inlen > 0);
6877 s->dlgret = ssh->user_response;
6879 ssh_set_frozen(ssh, 0);
6880 if (s->dlgret == 0) {
6881 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6887 if (s->ignorepkt) /* first_kex_packet_follows */
6888 crWaitUntilV(pktin); /* Ignore packet */
6891 if (ssh->kex->main_type == KEXTYPE_DH) {
6893 * Work out the number of bits of key we will need from the
6894 * key exchange. We start with the maximum key length of
6900 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6901 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6902 s->nbits = (csbits > scbits ? csbits : scbits);
6904 /* The keys only have hlen-bit entropy, since they're based on
6905 * a hash. So cap the key size at hlen bits. */
6906 if (s->nbits > ssh->kex->hash->hlen * 8)
6907 s->nbits = ssh->kex->hash->hlen * 8;
6910 * If we're doing Diffie-Hellman group exchange, start by
6911 * requesting a group.
6913 if (dh_is_gex(ssh->kex)) {
6914 logevent("Doing Diffie-Hellman group exchange");
6915 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6917 * Work out how big a DH group we will need to allow that
6920 s->pbits = 512 << ((s->nbits - 1) / 64);
6921 if (s->pbits < DH_MIN_SIZE)
6922 s->pbits = DH_MIN_SIZE;
6923 if (s->pbits > DH_MAX_SIZE)
6924 s->pbits = DH_MAX_SIZE;
6925 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6926 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6927 ssh2_pkt_adduint32(s->pktout, s->pbits);
6929 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6930 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6931 ssh2_pkt_adduint32(s->pktout, s->pbits);
6932 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6934 ssh2_pkt_send_noqueue(ssh, s->pktout);
6936 crWaitUntilV(pktin);
6937 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6938 bombout(("expected key exchange group packet from server"));
6941 s->p = ssh2_pkt_getmp(pktin);
6942 s->g = ssh2_pkt_getmp(pktin);
6943 if (!s->p || !s->g) {
6944 bombout(("unable to read mp-ints from incoming group packet"));
6947 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6948 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6949 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6951 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6952 ssh->kex_ctx = dh_setup_group(ssh->kex);
6953 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6954 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6955 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6956 ssh->kex->groupname);
6959 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6960 ssh->kex->hash->text_name);
6962 * Now generate and send e for Diffie-Hellman.
6964 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6965 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6966 s->pktout = ssh2_pkt_init(s->kex_init_value);
6967 ssh2_pkt_addmp(s->pktout, s->e);
6968 ssh2_pkt_send_noqueue(ssh, s->pktout);
6970 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6971 crWaitUntilV(pktin);
6972 if (pktin->type != s->kex_reply_value) {
6973 bombout(("expected key exchange reply packet from server"));
6976 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6977 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6978 if (!s->hostkeydata) {
6979 bombout(("unable to parse key exchange reply packet"));
6982 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6983 s->hostkeydata, s->hostkeylen);
6984 s->f = ssh2_pkt_getmp(pktin);
6986 bombout(("unable to parse key exchange reply packet"));
6989 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6991 bombout(("unable to parse key exchange reply packet"));
6996 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6998 bombout(("key exchange reply failed validation: %s", err));
7002 s->K = dh_find_K(ssh->kex_ctx, s->f);
7004 /* We assume everything from now on will be quick, and it might
7005 * involve user interaction. */
7006 set_busy_status(ssh->frontend, BUSY_NOT);
7008 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7009 if (dh_is_gex(ssh->kex)) {
7010 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7011 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7012 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7013 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7014 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7015 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7016 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7018 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7019 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7021 dh_cleanup(ssh->kex_ctx);
7023 if (dh_is_gex(ssh->kex)) {
7027 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7029 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7030 ssh_ecdhkex_curve_textname(ssh->kex),
7031 ssh->kex->hash->text_name);
7032 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7034 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7036 bombout(("Unable to generate key for ECDH"));
7042 int publicPointLength;
7043 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7045 ssh_ecdhkex_freekey(s->eckey);
7046 bombout(("Unable to encode public key for ECDH"));
7049 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7050 ssh2_pkt_addstring_start(s->pktout);
7051 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7055 ssh2_pkt_send_noqueue(ssh, s->pktout);
7057 crWaitUntilV(pktin);
7058 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7059 ssh_ecdhkex_freekey(s->eckey);
7060 bombout(("expected ECDH reply packet from server"));
7064 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7065 if (!s->hostkeydata) {
7066 bombout(("unable to parse ECDH reply packet"));
7069 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7070 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7071 s->hostkeydata, s->hostkeylen);
7075 int publicPointLength;
7076 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7078 ssh_ecdhkex_freekey(s->eckey);
7079 bombout(("Unable to encode public key for ECDH hash"));
7082 hash_string(ssh->kex->hash, ssh->exhash,
7083 publicPoint, publicPointLength);
7090 ssh_pkt_getstring(pktin, &keydata, &keylen);
7092 bombout(("unable to parse ECDH reply packet"));
7095 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7096 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7098 ssh_ecdhkex_freekey(s->eckey);
7099 bombout(("point received in ECDH was not valid"));
7104 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7106 bombout(("unable to parse key exchange reply packet"));
7110 ssh_ecdhkex_freekey(s->eckey);
7112 logeventf(ssh, "Doing RSA key exchange with hash %s",
7113 ssh->kex->hash->text_name);
7114 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7116 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7119 crWaitUntilV(pktin);
7120 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7121 bombout(("expected RSA public key packet from server"));
7125 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7126 if (!s->hostkeydata) {
7127 bombout(("unable to parse RSA public key packet"));
7130 hash_string(ssh->kex->hash, ssh->exhash,
7131 s->hostkeydata, s->hostkeylen);
7132 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7133 s->hostkeydata, s->hostkeylen);
7137 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7139 bombout(("unable to parse RSA public key packet"));
7142 s->rsakeydata = snewn(s->rsakeylen, char);
7143 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7146 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7148 sfree(s->rsakeydata);
7149 bombout(("unable to parse RSA public key from server"));
7153 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7156 * Next, set up a shared secret K, of precisely KLEN -
7157 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7158 * RSA key modulus and HLEN is the bit length of the hash
7162 int klen = ssh_rsakex_klen(s->rsakey);
7163 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7165 unsigned char *kstr1, *kstr2, *outstr;
7166 int kstr1len, kstr2len, outstrlen;
7168 s->K = bn_power_2(nbits - 1);
7170 for (i = 0; i < nbits; i++) {
7172 byte = random_byte();
7174 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7178 * Encode this as an mpint.
7180 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7181 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7182 PUT_32BIT(kstr2, kstr1len);
7183 memcpy(kstr2 + 4, kstr1, kstr1len);
7186 * Encrypt it with the given RSA key.
7188 outstrlen = (klen + 7) / 8;
7189 outstr = snewn(outstrlen, unsigned char);
7190 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7191 outstr, outstrlen, s->rsakey);
7194 * And send it off in a return packet.
7196 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7197 ssh2_pkt_addstring_start(s->pktout);
7198 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7199 ssh2_pkt_send_noqueue(ssh, s->pktout);
7201 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7208 ssh_rsakex_freekey(s->rsakey);
7210 crWaitUntilV(pktin);
7211 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7212 sfree(s->rsakeydata);
7213 bombout(("expected signature packet from server"));
7217 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7219 bombout(("unable to parse signature packet"));
7223 sfree(s->rsakeydata);
7226 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7227 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7228 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7230 ssh->kex_ctx = NULL;
7233 debug(("Exchange hash is:\n"));
7234 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7238 bombout(("Server's host key is invalid"));
7242 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7243 (char *)s->exchange_hash,
7244 ssh->kex->hash->hlen)) {
7246 bombout(("Server's host key did not match the signature supplied"));
7251 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7252 if (!s->got_session_id) {
7254 * Make a note of any other host key formats that are available.
7257 int i, j, nkeys = 0;
7259 for (i = 0; i < lenof(hostkey_algs); i++) {
7260 if (hostkey_algs[i].alg == ssh->hostkey)
7263 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7264 if (ssh->uncert_hostkeys[j] == i)
7267 if (j < ssh->n_uncert_hostkeys) {
7270 newlist = dupprintf("%s/%s", list,
7271 hostkey_algs[i].alg->name);
7273 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7281 "Server also has %s host key%s, but we "
7282 "don't know %s", list,
7283 nkeys > 1 ? "s" : "",
7284 nkeys > 1 ? "any of them" : "it");
7290 * Authenticate remote host: verify host key. (We've already
7291 * checked the signature of the exchange hash.)
7293 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7294 logevent("Host key fingerprint is:");
7295 logevent(s->fingerprint);
7296 /* First check against manually configured host keys. */
7297 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7298 ssh->hostkey, s->hkey);
7299 if (s->dlgret == 0) { /* did not match */
7300 bombout(("Host key did not appear in manually configured list"));
7302 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7303 ssh_set_frozen(ssh, 1);
7304 s->dlgret = verify_ssh_host_key(ssh->frontend,
7305 ssh->savedhost, ssh->savedport,
7306 ssh->hostkey->keytype, s->keystr,
7308 ssh_dialog_callback, ssh);
7312 if (s->dlgret < 0) {
7316 bombout(("Unexpected data from server while waiting"
7317 " for user host key response"));
7320 } while (pktin || inlen > 0);
7321 s->dlgret = ssh->user_response;
7323 ssh_set_frozen(ssh, 0);
7324 if (s->dlgret == 0) {
7325 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7330 sfree(s->fingerprint);
7332 * Save this host key, to check against the one presented in
7333 * subsequent rekeys.
7335 ssh->hostkey_str = s->keystr;
7336 } else if (ssh->cross_certifying) {
7337 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7338 logevent("Storing additional host key for this host:");
7339 logevent(s->fingerprint);
7340 store_host_key(ssh->savedhost, ssh->savedport,
7341 ssh->hostkey->keytype, s->keystr);
7342 ssh->cross_certifying = FALSE;
7344 * Don't forget to store the new key as the one we'll be
7345 * re-checking in future normal rekeys.
7347 ssh->hostkey_str = s->keystr;
7350 * In a rekey, we never present an interactive host key
7351 * verification request to the user. Instead, we simply
7352 * enforce that the key we're seeing this time is identical to
7353 * the one we saw before.
7355 if (strcmp(ssh->hostkey_str, s->keystr)) {
7357 bombout(("Host key was different in repeat key exchange"));
7363 ssh->hostkey->freekey(s->hkey);
7366 * The exchange hash from the very first key exchange is also
7367 * the session id, used in session key construction and
7370 if (!s->got_session_id) {
7371 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7372 memcpy(ssh->v2_session_id, s->exchange_hash,
7373 sizeof(s->exchange_hash));
7374 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7375 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7376 s->got_session_id = TRUE;
7380 * Send SSH2_MSG_NEWKEYS.
7382 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7383 ssh2_pkt_send_noqueue(ssh, s->pktout);
7384 ssh->outgoing_data_size = 0; /* start counting from here */
7387 * We've sent client NEWKEYS, so create and initialise
7388 * client-to-server session keys.
7390 if (ssh->cs_cipher_ctx)
7391 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7392 ssh->cscipher = s->cscipher_tobe;
7393 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7395 if (ssh->cs_mac_ctx)
7396 ssh->csmac->free_context(ssh->cs_mac_ctx);
7397 ssh->csmac = s->csmac_tobe;
7398 ssh->csmac_etm = s->csmac_etm_tobe;
7400 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7402 if (ssh->cs_comp_ctx)
7403 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7404 ssh->cscomp = s->cscomp_tobe;
7405 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7408 * Set IVs on client-to-server keys. Here we use the exchange
7409 * hash from the _first_ key exchange.
7411 if (ssh->cscipher) {
7414 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7415 ssh->cscipher->padded_keybytes);
7416 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7417 smemclr(key, ssh->cscipher->padded_keybytes);
7420 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7421 ssh->cscipher->blksize);
7422 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7423 smemclr(key, ssh->cscipher->blksize);
7429 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7430 ssh->csmac->keylen);
7431 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7432 smemclr(key, ssh->csmac->keylen);
7437 logeventf(ssh, "Initialised %.200s client->server encryption",
7438 ssh->cscipher->text_name);
7440 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7441 ssh->csmac->text_name,
7442 ssh->csmac_etm ? " (in ETM mode)" : "",
7443 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7444 if (ssh->cscomp->text_name)
7445 logeventf(ssh, "Initialised %s compression",
7446 ssh->cscomp->text_name);
7449 * Now our end of the key exchange is complete, we can send all
7450 * our queued higher-layer packets.
7452 ssh->queueing = FALSE;
7453 ssh2_pkt_queuesend(ssh);
7456 * Expect SSH2_MSG_NEWKEYS from server.
7458 crWaitUntilV(pktin);
7459 if (pktin->type != SSH2_MSG_NEWKEYS) {
7460 bombout(("expected new-keys packet from server"));
7463 ssh->incoming_data_size = 0; /* start counting from here */
7466 * We've seen server NEWKEYS, so create and initialise
7467 * server-to-client session keys.
7469 if (ssh->sc_cipher_ctx)
7470 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7471 if (s->sccipher_tobe) {
7472 ssh->sccipher = s->sccipher_tobe;
7473 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7476 if (ssh->sc_mac_ctx)
7477 ssh->scmac->free_context(ssh->sc_mac_ctx);
7478 if (s->scmac_tobe) {
7479 ssh->scmac = s->scmac_tobe;
7480 ssh->scmac_etm = s->scmac_etm_tobe;
7481 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7484 if (ssh->sc_comp_ctx)
7485 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7486 ssh->sccomp = s->sccomp_tobe;
7487 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7490 * Set IVs on server-to-client keys. Here we use the exchange
7491 * hash from the _first_ key exchange.
7493 if (ssh->sccipher) {
7496 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7497 ssh->sccipher->padded_keybytes);
7498 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7499 smemclr(key, ssh->sccipher->padded_keybytes);
7502 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7503 ssh->sccipher->blksize);
7504 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7505 smemclr(key, ssh->sccipher->blksize);
7511 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7512 ssh->scmac->keylen);
7513 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7514 smemclr(key, ssh->scmac->keylen);
7518 logeventf(ssh, "Initialised %.200s server->client encryption",
7519 ssh->sccipher->text_name);
7521 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7522 ssh->scmac->text_name,
7523 ssh->scmac_etm ? " (in ETM mode)" : "",
7524 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7525 if (ssh->sccomp->text_name)
7526 logeventf(ssh, "Initialised %s decompression",
7527 ssh->sccomp->text_name);
7530 * Free shared secret.
7535 * Update the specials menu to list the remaining uncertified host
7538 update_specials_menu(ssh->frontend);
7541 * Key exchange is over. Loop straight back round if we have a
7542 * deferred rekey reason.
7544 if (ssh->deferred_rekey_reason) {
7545 logevent(ssh->deferred_rekey_reason);
7547 ssh->deferred_rekey_reason = NULL;
7548 goto begin_key_exchange;
7552 * Otherwise, schedule a timer for our next rekey.
7554 ssh->kex_in_progress = FALSE;
7555 ssh->last_rekey = GETTICKCOUNT();
7556 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7557 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7561 * Now we're encrypting. Begin returning 1 to the protocol main
7562 * function so that other things can run on top of the
7563 * transport. If we ever see a KEXINIT, we must go back to the
7566 * We _also_ go back to the start if we see pktin==NULL and
7567 * inlen negative, because this is a special signal meaning
7568 * `initiate client-driven rekey', and `in' contains a message
7569 * giving the reason for the rekey.
7571 * inlen==-1 means always initiate a rekey;
7572 * inlen==-2 means that userauth has completed successfully and
7573 * we should consider rekeying (for delayed compression).
7575 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7576 (!pktin && inlen < 0))) {
7578 if (!ssh->protocol_initial_phase_done) {
7579 ssh->protocol_initial_phase_done = TRUE;
7581 * Allow authconn to initialise itself.
7583 do_ssh2_authconn(ssh, NULL, 0, NULL);
7588 logevent("Server initiated key re-exchange");
7592 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7593 * delayed compression, if it's available.
7595 * draft-miller-secsh-compression-delayed-00 says that you
7596 * negotiate delayed compression in the first key exchange, and
7597 * both sides start compressing when the server has sent
7598 * USERAUTH_SUCCESS. This has a race condition -- the server
7599 * can't know when the client has seen it, and thus which incoming
7600 * packets it should treat as compressed.
7602 * Instead, we do the initial key exchange without offering the
7603 * delayed methods, but note if the server offers them; when we
7604 * get here, if a delayed method was available that was higher
7605 * on our list than what we got, we initiate a rekey in which we
7606 * _do_ list the delayed methods (and hopefully get it as a
7607 * result). Subsequent rekeys will do the same.
7609 assert(!s->userauth_succeeded); /* should only happen once */
7610 s->userauth_succeeded = TRUE;
7611 if (!s->pending_compression)
7612 /* Can't see any point rekeying. */
7613 goto wait_for_rekey; /* this is utterly horrid */
7614 /* else fall through to rekey... */
7615 s->pending_compression = FALSE;
7618 * Now we've decided to rekey.
7620 * Special case: if the server bug is set that doesn't
7621 * allow rekeying, we give a different log message and
7622 * continue waiting. (If such a server _initiates_ a rekey,
7623 * we process it anyway!)
7625 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7626 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7628 /* Reset the counters, so that at least this message doesn't
7629 * hit the event log _too_ often. */
7630 ssh->outgoing_data_size = 0;
7631 ssh->incoming_data_size = 0;
7632 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7634 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7637 goto wait_for_rekey; /* this is still utterly horrid */
7639 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7642 goto begin_key_exchange;
7648 * Send data on an SSH channel. In SSH-2, this involves buffering it
7651 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7654 if (c->ssh->version == 2) {
7655 bufchain_add(&c->v.v2.outbuffer, buf, len);
7656 return ssh2_try_send(c);
7658 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7659 PKT_INT, c->remoteid,
7664 * In SSH-1 we can return 0 here - implying that channels are
7665 * never individually throttled - because the only
7666 * circumstance that can cause throttling will be the whole
7667 * SSH connection backing up, in which case _everything_ will
7668 * be throttled as a whole.
7675 * Attempt to send data on an SSH-2 channel.
7677 static int ssh2_try_send(struct ssh_channel *c)
7680 struct Packet *pktout;
7683 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7686 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7687 if ((unsigned)len > c->v.v2.remwindow)
7688 len = c->v.v2.remwindow;
7689 if ((unsigned)len > c->v.v2.remmaxpkt)
7690 len = c->v.v2.remmaxpkt;
7691 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7692 ssh2_pkt_adduint32(pktout, c->remoteid);
7693 ssh2_pkt_addstring_start(pktout);
7694 ssh2_pkt_addstring_data(pktout, data, len);
7695 ssh2_pkt_send(ssh, pktout);
7696 bufchain_consume(&c->v.v2.outbuffer, len);
7697 c->v.v2.remwindow -= len;
7701 * After having sent as much data as we can, return the amount
7704 ret = bufchain_size(&c->v.v2.outbuffer);
7707 * And if there's no data pending but we need to send an EOF, send
7710 if (!ret && c->pending_eof)
7711 ssh_channel_try_eof(c);
7716 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7719 if (c->closes & CLOSES_SENT_EOF)
7720 return; /* don't send on channels we've EOFed */
7721 bufsize = ssh2_try_send(c);
7724 case CHAN_MAINSESSION:
7725 /* stdin need not receive an unthrottle
7726 * notification since it will be polled */
7729 x11_unthrottle(c->u.x11.xconn);
7732 /* agent sockets are request/response and need no
7733 * buffer management */
7736 pfd_unthrottle(c->u.pfd.pf);
7742 static int ssh_is_simple(Ssh ssh)
7745 * We use the 'simple' variant of the SSH protocol if we're asked
7746 * to, except not if we're also doing connection-sharing (either
7747 * tunnelling our packets over an upstream or expecting to be
7748 * tunnelled over ourselves), since then the assumption that we
7749 * have only one channel to worry about is not true after all.
7751 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7752 !ssh->bare_connection && !ssh->connshare);
7756 * Set up most of a new ssh_channel.
7758 static void ssh_channel_init(struct ssh_channel *c)
7761 c->localid = alloc_channel_id(ssh);
7763 c->pending_eof = FALSE;
7764 c->throttling_conn = FALSE;
7765 if (ssh->version == 2) {
7766 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7767 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7768 c->v.v2.chanreq_head = NULL;
7769 c->v.v2.throttle_state = UNTHROTTLED;
7770 bufchain_init(&c->v.v2.outbuffer);
7772 add234(ssh->channels, c);
7776 * Construct the common parts of a CHANNEL_OPEN.
7778 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7781 struct Packet *pktout;
7783 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7784 ssh2_pkt_addstring(pktout, type);
7785 ssh2_pkt_adduint32(pktout, c->localid);
7786 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7787 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7792 * CHANNEL_FAILURE doesn't come with any indication of what message
7793 * caused it, so we have to keep track of the outstanding
7794 * CHANNEL_REQUESTs ourselves.
7796 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7797 cchandler_fn_t handler, void *ctx)
7799 struct outstanding_channel_request *ocr =
7800 snew(struct outstanding_channel_request);
7802 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7803 ocr->handler = handler;
7806 if (!c->v.v2.chanreq_head)
7807 c->v.v2.chanreq_head = ocr;
7809 c->v.v2.chanreq_tail->next = ocr;
7810 c->v.v2.chanreq_tail = ocr;
7814 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7815 * NULL then a reply will be requested and the handler will be called
7816 * when it arrives. The returned packet is ready to have any
7817 * request-specific data added and be sent. Note that if a handler is
7818 * provided, it's essential that the request actually be sent.
7820 * The handler will usually be passed the response packet in pktin. If
7821 * pktin is NULL, this means that no reply will ever be forthcoming
7822 * (e.g. because the entire connection is being destroyed, or because
7823 * the server initiated channel closure before we saw the response)
7824 * and the handler should free any storage it's holding.
7826 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7828 cchandler_fn_t handler, void *ctx)
7830 struct Packet *pktout;
7832 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7833 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7834 ssh2_pkt_adduint32(pktout, c->remoteid);
7835 ssh2_pkt_addstring(pktout, type);
7836 ssh2_pkt_addbool(pktout, handler != NULL);
7837 if (handler != NULL)
7838 ssh2_queue_chanreq_handler(c, handler, ctx);
7842 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize)
7847 if (ssh->version == 1) {
7848 buflimit = SSH1_BUFFER_LIMIT;
7850 if (ssh_is_simple(ssh))
7853 buflimit = c->v.v2.locmaxwin;
7854 if (bufsize < buflimit)
7855 ssh2_set_window(c, buflimit - bufsize);
7857 if (c->throttling_conn && bufsize <= buflimit) {
7858 c->throttling_conn = 0;
7859 ssh_throttle_conn(ssh, -1);
7864 * Potentially enlarge the window on an SSH-2 channel.
7866 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7868 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7873 * Never send WINDOW_ADJUST for a channel that the remote side has
7874 * already sent EOF on; there's no point, since it won't be
7875 * sending any more data anyway. Ditto if _we've_ already sent
7878 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7882 * Also, never widen the window for an X11 channel when we're
7883 * still waiting to see its initial auth and may yet hand it off
7886 if (c->type == CHAN_X11 && c->u.x11.initial)
7890 * If the remote end has a habit of ignoring maxpkt, limit the
7891 * window so that it has no choice (assuming it doesn't ignore the
7894 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7895 newwin = OUR_V2_MAXPKT;
7898 * Only send a WINDOW_ADJUST if there's significantly more window
7899 * available than the other end thinks there is. This saves us
7900 * sending a WINDOW_ADJUST for every character in a shell session.
7902 * "Significant" is arbitrarily defined as half the window size.
7904 if (newwin / 2 >= c->v.v2.locwindow) {
7905 struct Packet *pktout;
7909 * In order to keep track of how much window the client
7910 * actually has available, we'd like it to acknowledge each
7911 * WINDOW_ADJUST. We can't do that directly, so we accompany
7912 * it with a CHANNEL_REQUEST that has to be acknowledged.
7914 * This is only necessary if we're opening the window wide.
7915 * If we're not, then throughput is being constrained by
7916 * something other than the maximum window size anyway.
7918 if (newwin == c->v.v2.locmaxwin &&
7919 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7920 up = snew(unsigned);
7921 *up = newwin - c->v.v2.locwindow;
7922 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7923 ssh2_handle_winadj_response, up);
7924 ssh2_pkt_send(ssh, pktout);
7926 if (c->v.v2.throttle_state != UNTHROTTLED)
7927 c->v.v2.throttle_state = UNTHROTTLING;
7929 /* Pretend the WINDOW_ADJUST was acked immediately. */
7930 c->v.v2.remlocwin = newwin;
7931 c->v.v2.throttle_state = THROTTLED;
7933 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7934 ssh2_pkt_adduint32(pktout, c->remoteid);
7935 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7936 ssh2_pkt_send(ssh, pktout);
7937 c->v.v2.locwindow = newwin;
7942 * Find the channel associated with a message. If there's no channel,
7943 * or it's not properly open, make a noise about it and return NULL.
7944 * If the channel is shared, pass the message on to downstream and
7945 * also return NULL (meaning the caller should ignore this message).
7947 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin)
7949 unsigned localid = ssh_pkt_getuint32(pktin);
7950 struct ssh_channel *c;
7953 /* Is this message OK on a half-open connection? */
7954 if (ssh->version == 1)
7955 halfopen_ok = (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION ||
7956 pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE);
7958 halfopen_ok = (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION ||
7959 pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE);
7960 c = find234(ssh->channels, &localid, ssh_channelfind);
7961 if (!c || (c->type != CHAN_SHARING && (c->halfopen != halfopen_ok))) {
7962 char *buf = dupprintf("Received %s for %s channel %u",
7963 ssh_pkt_type(ssh, pktin->type),
7964 !c ? "nonexistent" :
7965 c->halfopen ? "half-open" : "open",
7967 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7971 if (c->type == CHAN_SHARING) {
7972 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7973 pktin->body, pktin->length);
7979 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7980 struct Packet *pktin, void *ctx)
7982 unsigned *sizep = ctx;
7985 * Winadj responses should always be failures. However, at least
7986 * one server ("boks_sshd") is known to return SUCCESS for channel
7987 * requests it's never heard of, such as "winadj@putty". Raised
7988 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7989 * life, we don't worry about what kind of response we got.
7992 c->v.v2.remlocwin += *sizep;
7995 * winadj messages are only sent when the window is fully open, so
7996 * if we get an ack of one, we know any pending unthrottle is
7999 if (c->v.v2.throttle_state == UNTHROTTLING)
8000 c->v.v2.throttle_state = UNTHROTTLED;
8003 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
8005 struct ssh_channel *c = ssh_channel_msg(ssh, pktin);
8006 struct outstanding_channel_request *ocr;
8009 ocr = c->v.v2.chanreq_head;
8011 ssh2_msg_unexpected(ssh, pktin);
8014 ocr->handler(c, pktin, ocr->ctx);
8015 c->v.v2.chanreq_head = ocr->next;
8018 * We may now initiate channel-closing procedures, if that
8019 * CHANNEL_REQUEST was the last thing outstanding before we send
8022 ssh2_channel_check_close(c);
8025 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8027 struct ssh_channel *c;
8028 c = ssh_channel_msg(ssh, pktin);
8031 if (!(c->closes & CLOSES_SENT_EOF)) {
8032 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
8033 ssh2_try_send_and_unthrottle(ssh, c);
8037 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8041 unsigned ext_type = 0; /* 0 means not extended */
8042 struct ssh_channel *c;
8043 c = ssh_channel_msg(ssh, pktin);
8046 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
8047 ext_type = ssh_pkt_getuint32(pktin);
8048 ssh_pkt_getstring(pktin, &data, &length);
8051 c->v.v2.locwindow -= length;
8052 c->v.v2.remlocwin -= length;
8053 if (ext_type != 0 && ext_type != SSH2_EXTENDED_DATA_STDERR)
8054 length = 0; /* Don't do anything with unknown extended data. */
8055 bufsize = ssh_channel_data(c, ext_type == SSH2_EXTENDED_DATA_STDERR,
8058 * If it looks like the remote end hit the end of its window,
8059 * and we didn't want it to do that, think about using a
8062 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8063 c->v.v2.locmaxwin < 0x40000000)
8064 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8066 * If we are not buffering too much data,
8067 * enlarge the window again at the remote side.
8068 * If we are buffering too much, we may still
8069 * need to adjust the window if the server's
8072 if (bufsize < c->v.v2.locmaxwin)
8073 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
8075 * If we're either buffering way too much data, or if we're
8076 * buffering anything at all and we're in "simple" mode,
8077 * throttle the whole channel.
8079 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8080 && !c->throttling_conn) {
8081 c->throttling_conn = 1;
8082 ssh_throttle_conn(ssh, +1);
8087 static void ssh_check_termination(Ssh ssh)
8089 if (ssh->version == 2 &&
8090 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8091 (ssh->channels && count234(ssh->channels) == 0) &&
8092 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8094 * We used to send SSH_MSG_DISCONNECT here, because I'd
8095 * believed that _every_ conforming SSH-2 connection had to
8096 * end with a disconnect being sent by at least one side;
8097 * apparently I was wrong and it's perfectly OK to
8098 * unceremoniously slam the connection shut when you're done,
8099 * and indeed OpenSSH feels this is more polite than sending a
8100 * DISCONNECT. So now we don't.
8102 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8106 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8107 const char *peerinfo)
8110 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8113 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8116 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8118 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8119 ssh_check_termination(ssh);
8122 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8127 va_start(ap, logfmt);
8128 buf = dupvprintf(logfmt, ap);
8131 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8133 logeventf(ssh, "Connection sharing: %s", buf);
8137 static void ssh_channel_destroy(struct ssh_channel *c)
8142 case CHAN_MAINSESSION:
8143 ssh->mainchan = NULL;
8144 update_specials_menu(ssh->frontend);
8147 assert(c->u.x11.xconn != NULL);
8148 x11_close(c->u.x11.xconn);
8149 logevent("Forwarded X11 connection terminated");
8152 sfree(c->u.a.message);
8155 assert(c->u.pfd.pf != NULL);
8156 pfd_close(c->u.pfd.pf);
8157 logevent("Forwarded port closed");
8161 del234(ssh->channels, c);
8162 if (ssh->version == 2) {
8163 bufchain_clear(&c->v.v2.outbuffer);
8164 assert(c->v.v2.chanreq_head == NULL);
8169 * If that was the last channel left open, we might need to
8172 ssh_check_termination(ssh);
8175 static void ssh2_channel_check_close(struct ssh_channel *c)
8178 struct Packet *pktout;
8180 assert(ssh->version == 2);
8183 * If we've sent out our own CHANNEL_OPEN but not yet seen
8184 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8185 * it's too early to be sending close messages of any kind.
8190 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8191 c->type == CHAN_ZOMBIE) &&
8192 !c->v.v2.chanreq_head &&
8193 !(c->closes & CLOSES_SENT_CLOSE)) {
8195 * We have both sent and received EOF (or the channel is a
8196 * zombie), and we have no outstanding channel requests, which
8197 * means the channel is in final wind-up. But we haven't sent
8198 * CLOSE, so let's do so now.
8200 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8201 ssh2_pkt_adduint32(pktout, c->remoteid);
8202 ssh2_pkt_send(ssh, pktout);
8203 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8206 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8207 assert(c->v.v2.chanreq_head == NULL);
8209 * We have both sent and received CLOSE, which means we're
8210 * completely done with the channel.
8212 ssh_channel_destroy(c);
8216 static void ssh_channel_got_eof(struct ssh_channel *c)
8218 if (c->closes & CLOSES_RCVD_EOF)
8219 return; /* already seen EOF */
8220 c->closes |= CLOSES_RCVD_EOF;
8222 if (c->type == CHAN_X11) {
8223 assert(c->u.x11.xconn != NULL);
8224 x11_send_eof(c->u.x11.xconn);
8225 } else if (c->type == CHAN_AGENT) {
8226 if (c->u.a.outstanding_requests == 0) {
8227 /* Manufacture an outgoing EOF in response to the incoming one. */
8228 sshfwd_write_eof(c);
8230 } else if (c->type == CHAN_SOCKDATA) {
8231 assert(c->u.pfd.pf != NULL);
8232 pfd_send_eof(c->u.pfd.pf);
8233 } else if (c->type == CHAN_MAINSESSION) {
8236 if (!ssh->sent_console_eof &&
8237 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8239 * Either from_backend_eof told us that the front end
8240 * wants us to close the outgoing side of the connection
8241 * as soon as we see EOF from the far end, or else we've
8242 * unilaterally decided to do that because we've allocated
8243 * a remote pty and hence EOF isn't a particularly
8244 * meaningful concept.
8246 sshfwd_write_eof(c);
8248 ssh->sent_console_eof = TRUE;
8252 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8254 struct ssh_channel *c;
8256 c = ssh_channel_msg(ssh, pktin);
8259 ssh_channel_got_eof(c);
8260 ssh2_channel_check_close(c);
8263 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8265 struct ssh_channel *c;
8267 c = ssh_channel_msg(ssh, pktin);
8272 * When we receive CLOSE on a channel, we assume it comes with an
8273 * implied EOF if we haven't seen EOF yet.
8275 ssh_channel_got_eof(c);
8277 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8279 * It also means we stop expecting to see replies to any
8280 * outstanding channel requests, so clean those up too.
8281 * (ssh_chanreq_init will enforce by assertion that we don't
8282 * subsequently put anything back on this list.)
8284 while (c->v.v2.chanreq_head) {
8285 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8286 ocr->handler(c, NULL, ocr->ctx);
8287 c->v.v2.chanreq_head = ocr->next;
8293 * And we also send an outgoing EOF, if we haven't already, on the
8294 * assumption that CLOSE is a pretty forceful announcement that
8295 * the remote side is doing away with the entire channel. (If it
8296 * had wanted to send us EOF and continue receiving data from us,
8297 * it would have just sent CHANNEL_EOF.)
8299 if (!(c->closes & CLOSES_SENT_EOF)) {
8301 * Make sure we don't read any more from whatever our local
8302 * data source is for this channel.
8305 case CHAN_MAINSESSION:
8306 ssh->send_ok = 0; /* stop trying to read from stdin */
8309 x11_override_throttle(c->u.x11.xconn, 1);
8312 pfd_override_throttle(c->u.pfd.pf, 1);
8317 * Abandon any buffered data we still wanted to send to this
8318 * channel. Receiving a CHANNEL_CLOSE is an indication that
8319 * the server really wants to get on and _destroy_ this
8320 * channel, and it isn't going to send us any further
8321 * WINDOW_ADJUSTs to permit us to send pending stuff.
8323 bufchain_clear(&c->v.v2.outbuffer);
8326 * Send outgoing EOF.
8328 sshfwd_write_eof(c);
8332 * Now process the actual close.
8334 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8335 c->closes |= CLOSES_RCVD_CLOSE;
8336 ssh2_channel_check_close(c);
8340 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8342 struct ssh_channel *c;
8344 c = ssh_channel_msg(ssh, pktin);
8347 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8348 c->remoteid = ssh_pkt_getuint32(pktin);
8349 c->halfopen = FALSE;
8350 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8351 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8353 if (c->type == CHAN_SOCKDATA) {
8354 assert(c->u.pfd.pf != NULL);
8355 pfd_confirm(c->u.pfd.pf);
8356 } else if (c->type == CHAN_ZOMBIE) {
8358 * This case can occur if a local socket error occurred
8359 * between us sending out CHANNEL_OPEN and receiving
8360 * OPEN_CONFIRMATION. In this case, all we can do is
8361 * immediately initiate close proceedings now that we know the
8362 * server's id to put in the close message.
8364 ssh2_channel_check_close(c);
8367 * We never expect to receive OPEN_CONFIRMATION for any
8368 * *other* channel type (since only local-to-remote port
8369 * forwardings cause us to send CHANNEL_OPEN after the main
8370 * channel is live - all other auxiliary channel types are
8371 * initiated from the server end). It's safe to enforce this
8372 * by assertion rather than by ssh_disconnect, because the
8373 * real point is that we never constructed a half-open channel
8374 * structure in the first place with any type other than the
8377 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8381 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8384 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8386 static const char *const reasons[] = {
8387 "<unknown reason code>",
8388 "Administratively prohibited",
8390 "Unknown channel type",
8391 "Resource shortage",
8393 unsigned reason_code;
8394 char *reason_string;
8396 struct ssh_channel *c;
8398 c = ssh_channel_msg(ssh, pktin);
8401 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8403 if (c->type == CHAN_SOCKDATA) {
8404 reason_code = ssh_pkt_getuint32(pktin);
8405 if (reason_code >= lenof(reasons))
8406 reason_code = 0; /* ensure reasons[reason_code] in range */
8407 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8408 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8409 reasons[reason_code], reason_length,
8410 NULLTOEMPTY(reason_string));
8412 pfd_close(c->u.pfd.pf);
8413 } else if (c->type == CHAN_ZOMBIE) {
8415 * This case can occur if a local socket error occurred
8416 * between us sending out CHANNEL_OPEN and receiving
8417 * OPEN_FAILURE. In this case, we need do nothing except allow
8418 * the code below to throw the half-open channel away.
8422 * We never expect to receive OPEN_FAILURE for any *other*
8423 * channel type (since only local-to-remote port forwardings
8424 * cause us to send CHANNEL_OPEN after the main channel is
8425 * live - all other auxiliary channel types are initiated from
8426 * the server end). It's safe to enforce this by assertion
8427 * rather than by ssh_disconnect, because the real point is
8428 * that we never constructed a half-open channel structure in
8429 * the first place with any type other than the above.
8431 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8434 del234(ssh->channels, c);
8438 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8441 int typelen, want_reply;
8442 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8443 struct ssh_channel *c;
8444 struct Packet *pktout;
8446 c = ssh_channel_msg(ssh, pktin);
8449 ssh_pkt_getstring(pktin, &type, &typelen);
8450 want_reply = ssh2_pkt_getbool(pktin);
8452 if (c->closes & CLOSES_SENT_CLOSE) {
8454 * We don't reply to channel requests after we've sent
8455 * CHANNEL_CLOSE for the channel, because our reply might
8456 * cross in the network with the other side's CHANNEL_CLOSE
8457 * and arrive after they have wound the channel up completely.
8463 * Having got the channel number, we now look at
8464 * the request type string to see if it's something
8467 if (c == ssh->mainchan) {
8469 * We recognise "exit-status" and "exit-signal" on
8470 * the primary channel.
8472 if (typelen == 11 &&
8473 !memcmp(type, "exit-status", 11)) {
8475 ssh->exitcode = ssh_pkt_getuint32(pktin);
8476 logeventf(ssh, "Server sent command exit status %d",
8478 reply = SSH2_MSG_CHANNEL_SUCCESS;
8480 } else if (typelen == 11 &&
8481 !memcmp(type, "exit-signal", 11)) {
8483 int is_plausible = TRUE, is_int = FALSE;
8484 char *fmt_sig = NULL, *fmt_msg = NULL;
8486 int msglen = 0, core = FALSE;
8487 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8488 * provide an `int' for the signal, despite its
8489 * having been a `string' in the drafts of RFC 4254 since at
8490 * least 2001. (Fixed in session.c 1.147.) Try to
8491 * infer which we can safely parse it as. */
8493 unsigned char *p = pktin->body +
8495 long len = pktin->length - pktin->savedpos;
8496 unsigned long num = GET_32BIT(p); /* what is it? */
8497 /* If it's 0, it hardly matters; assume string */
8501 int maybe_int = FALSE, maybe_str = FALSE;
8502 #define CHECK_HYPOTHESIS(offset, result) \
8505 int q = toint(offset); \
8506 if (q >= 0 && q+4 <= len) { \
8507 q = toint(q + 4 + GET_32BIT(p+q)); \
8508 if (q >= 0 && q+4 <= len && \
8509 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8514 CHECK_HYPOTHESIS(4+1, maybe_int);
8515 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8516 #undef CHECK_HYPOTHESIS
8517 if (maybe_int && !maybe_str)
8519 else if (!maybe_int && maybe_str)
8522 /* Crikey. Either or neither. Panic. */
8523 is_plausible = FALSE;
8526 ssh->exitcode = 128; /* means `unknown signal' */
8529 /* Old non-standard OpenSSH. */
8530 int signum = ssh_pkt_getuint32(pktin);
8531 fmt_sig = dupprintf(" %d", signum);
8532 ssh->exitcode = 128 + signum;
8534 /* As per RFC 4254. */
8537 ssh_pkt_getstring(pktin, &sig, &siglen);
8538 /* Signal name isn't supposed to be blank, but
8539 * let's cope gracefully if it is. */
8541 fmt_sig = dupprintf(" \"%.*s\"",
8546 * Really hideous method of translating the
8547 * signal description back into a locally
8548 * meaningful number.
8553 #define TRANSLATE_SIGNAL(s) \
8554 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8555 ssh->exitcode = 128 + SIG ## s
8557 TRANSLATE_SIGNAL(ABRT);
8560 TRANSLATE_SIGNAL(ALRM);
8563 TRANSLATE_SIGNAL(FPE);
8566 TRANSLATE_SIGNAL(HUP);
8569 TRANSLATE_SIGNAL(ILL);
8572 TRANSLATE_SIGNAL(INT);
8575 TRANSLATE_SIGNAL(KILL);
8578 TRANSLATE_SIGNAL(PIPE);
8581 TRANSLATE_SIGNAL(QUIT);
8584 TRANSLATE_SIGNAL(SEGV);
8587 TRANSLATE_SIGNAL(TERM);
8590 TRANSLATE_SIGNAL(USR1);
8593 TRANSLATE_SIGNAL(USR2);
8595 #undef TRANSLATE_SIGNAL
8597 ssh->exitcode = 128;
8599 core = ssh2_pkt_getbool(pktin);
8600 ssh_pkt_getstring(pktin, &msg, &msglen);
8602 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8604 /* ignore lang tag */
8605 } /* else don't attempt to parse */
8606 logeventf(ssh, "Server exited on signal%s%s%s",
8607 fmt_sig ? fmt_sig : "",
8608 core ? " (core dumped)" : "",
8609 fmt_msg ? fmt_msg : "");
8612 reply = SSH2_MSG_CHANNEL_SUCCESS;
8617 * This is a channel request we don't know
8618 * about, so we now either ignore the request
8619 * or respond with CHANNEL_FAILURE, depending
8622 reply = SSH2_MSG_CHANNEL_FAILURE;
8625 pktout = ssh2_pkt_init(reply);
8626 ssh2_pkt_adduint32(pktout, c->remoteid);
8627 ssh2_pkt_send(ssh, pktout);
8631 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8634 int typelen, want_reply;
8635 struct Packet *pktout;
8637 ssh_pkt_getstring(pktin, &type, &typelen);
8638 want_reply = ssh2_pkt_getbool(pktin);
8641 * We currently don't support any global requests
8642 * at all, so we either ignore the request or
8643 * respond with REQUEST_FAILURE, depending on
8647 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8648 ssh2_pkt_send(ssh, pktout);
8652 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8656 struct X11FakeAuth *auth;
8659 * Make up a new set of fake X11 auth data, and add it to the tree
8660 * of currently valid ones with an indication of the sharing
8661 * context that it's relevant to.
8663 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8664 auth->share_cs = share_cs;
8665 auth->share_chan = share_chan;
8670 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8672 del234(ssh->x11authtree, auth);
8673 x11_free_fake_auth(auth);
8676 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8683 const char *error = NULL;
8684 struct ssh_channel *c;
8685 unsigned remid, winsize, pktsize;
8686 unsigned our_winsize_override = 0;
8687 struct Packet *pktout;
8689 ssh_pkt_getstring(pktin, &type, &typelen);
8690 c = snew(struct ssh_channel);
8693 remid = ssh_pkt_getuint32(pktin);
8694 winsize = ssh_pkt_getuint32(pktin);
8695 pktsize = ssh_pkt_getuint32(pktin);
8697 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8700 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8701 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8702 peerport = ssh_pkt_getuint32(pktin);
8704 logeventf(ssh, "Received X11 connect request from %s:%d",
8707 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8708 error = "X11 forwarding is not enabled";
8710 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8713 c->u.x11.initial = TRUE;
8716 * If we are a connection-sharing upstream, then we should
8717 * initially present a very small window, adequate to take
8718 * the X11 initial authorisation packet but not much more.
8719 * Downstream will then present us a larger window (by
8720 * fiat of the connection-sharing protocol) and we can
8721 * guarantee to send a positive-valued WINDOW_ADJUST.
8724 our_winsize_override = 128;
8726 logevent("Opened X11 forward channel");
8730 } else if (typelen == 15 &&
8731 !memcmp(type, "forwarded-tcpip", 15)) {
8732 struct ssh_rportfwd pf, *realpf;
8735 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8736 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8737 pf.sport = ssh_pkt_getuint32(pktin);
8738 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8739 peerport = ssh_pkt_getuint32(pktin);
8740 realpf = find234(ssh->rportfwds, &pf, NULL);
8741 logeventf(ssh, "Received remote port %s:%d open request "
8742 "from %.*s:%d", pf.shost, pf.sport,
8743 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8746 if (realpf == NULL) {
8747 error = "Remote port is not recognised";
8751 if (realpf->share_ctx) {
8753 * This port forwarding is on behalf of a
8754 * connection-sharing downstream, so abandon our own
8755 * channel-open procedure and just pass the message on
8758 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8759 pktin->body, pktin->length);
8764 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8765 c, ssh->conf, realpf->pfrec->addressfamily);
8766 logeventf(ssh, "Attempting to forward remote port to "
8767 "%s:%d", realpf->dhost, realpf->dport);
8769 logeventf(ssh, "Port open failed: %s", err);
8771 error = "Port open failed";
8773 logevent("Forwarded port opened successfully");
8774 c->type = CHAN_SOCKDATA;
8777 } else if (typelen == 22 &&
8778 !memcmp(type, "auth-agent@openssh.com", 22)) {
8779 if (!ssh->agentfwd_enabled)
8780 error = "Agent forwarding is not enabled";
8782 c->type = CHAN_AGENT; /* identify channel type */
8783 c->u.a.lensofar = 0;
8784 c->u.a.message = NULL;
8785 c->u.a.outstanding_requests = 0;
8788 error = "Unsupported channel type requested";
8791 c->remoteid = remid;
8792 c->halfopen = FALSE;
8794 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8795 ssh2_pkt_adduint32(pktout, c->remoteid);
8796 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8797 ssh2_pkt_addstring(pktout, error);
8798 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8799 ssh2_pkt_send(ssh, pktout);
8800 logeventf(ssh, "Rejected channel open: %s", error);
8803 ssh_channel_init(c);
8804 c->v.v2.remwindow = winsize;
8805 c->v.v2.remmaxpkt = pktsize;
8806 if (our_winsize_override) {
8807 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8808 our_winsize_override;
8810 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8811 ssh2_pkt_adduint32(pktout, c->remoteid);
8812 ssh2_pkt_adduint32(pktout, c->localid);
8813 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8814 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8815 ssh2_pkt_send(ssh, pktout);
8819 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8820 void *share_cs, void *share_chan,
8821 const char *peer_addr, int peer_port,
8822 int endian, int protomajor, int protominor,
8823 const void *initial_data, int initial_len)
8826 * This function is called when we've just discovered that an X
8827 * forwarding channel on which we'd been handling the initial auth
8828 * ourselves turns out to be destined for a connection-sharing
8829 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8830 * that we completely stop tracking windows and buffering data and
8831 * just pass more or less unmodified SSH messages back and forth.
8833 c->type = CHAN_SHARING;
8834 c->u.sharing.ctx = share_cs;
8835 share_setup_x11_channel(share_cs, share_chan,
8836 c->localid, c->remoteid, c->v.v2.remwindow,
8837 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8838 peer_addr, peer_port, endian,
8839 protomajor, protominor,
8840 initial_data, initial_len);
8843 void sshfwd_x11_is_local(struct ssh_channel *c)
8846 * This function is called when we've just discovered that an X
8847 * forwarding channel is _not_ destined for a connection-sharing
8848 * downstream but we're going to handle it ourselves. We stop
8849 * presenting a cautiously small window and go into ordinary data
8852 c->u.x11.initial = FALSE;
8853 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8857 * Buffer banner messages for later display at some convenient point,
8858 * if we're going to display them.
8860 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8862 /* Arbitrary limit to prevent unbounded inflation of buffer */
8863 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8864 bufchain_size(&ssh->banner) <= 131072) {
8865 char *banner = NULL;
8867 ssh_pkt_getstring(pktin, &banner, &size);
8869 bufchain_add(&ssh->banner, banner, size);
8873 /* Helper function to deal with sending tty modes for "pty-req" */
8874 static void ssh2_send_ttymode(void *data,
8875 const struct ssh_ttymode *mode, char *val)
8877 struct Packet *pktout = (struct Packet *)data;
8878 unsigned int arg = 0;
8880 switch (mode->type) {
8882 arg = ssh_tty_parse_specchar(val);
8885 arg = ssh_tty_parse_boolean(val);
8888 ssh2_pkt_addbyte(pktout, mode->opcode);
8889 ssh2_pkt_adduint32(pktout, arg);
8892 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8895 struct ssh2_setup_x11_state {
8899 struct Packet *pktout;
8900 crStateP(ssh2_setup_x11_state, ctx);
8904 logevent("Requesting X11 forwarding");
8905 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8907 ssh2_pkt_addbool(pktout, 0); /* many connections */
8908 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8909 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8910 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8911 ssh2_pkt_send(ssh, pktout);
8913 /* Wait to be called back with either a response packet, or NULL
8914 * meaning clean up and free our data */
8918 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8919 logevent("X11 forwarding enabled");
8920 ssh->X11_fwd_enabled = TRUE;
8922 logevent("X11 forwarding refused");
8928 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8931 struct ssh2_setup_agent_state {
8935 struct Packet *pktout;
8936 crStateP(ssh2_setup_agent_state, ctx);
8940 logevent("Requesting OpenSSH-style agent forwarding");
8941 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8942 ssh2_setup_agent, s);
8943 ssh2_pkt_send(ssh, pktout);
8945 /* Wait to be called back with either a response packet, or NULL
8946 * meaning clean up and free our data */
8950 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8951 logevent("Agent forwarding enabled");
8952 ssh->agentfwd_enabled = TRUE;
8954 logevent("Agent forwarding refused");
8960 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8963 struct ssh2_setup_pty_state {
8967 struct Packet *pktout;
8968 crStateP(ssh2_setup_pty_state, ctx);
8972 /* Unpick the terminal-speed string. */
8973 /* XXX perhaps we should allow no speeds to be sent. */
8974 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8975 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8976 /* Build the pty request. */
8977 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8979 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8980 ssh2_pkt_adduint32(pktout, ssh->term_width);
8981 ssh2_pkt_adduint32(pktout, ssh->term_height);
8982 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8983 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8984 ssh2_pkt_addstring_start(pktout);
8985 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8986 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8987 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8988 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8989 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8990 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8991 ssh2_pkt_send(ssh, pktout);
8992 ssh->state = SSH_STATE_INTERMED;
8994 /* Wait to be called back with either a response packet, or NULL
8995 * meaning clean up and free our data */
8999 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9000 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9001 ssh->ospeed, ssh->ispeed);
9002 ssh->got_pty = TRUE;
9004 c_write_str(ssh, "Server refused to allocate pty\r\n");
9005 ssh->editing = ssh->echoing = 1;
9012 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9015 struct ssh2_setup_env_state {
9017 int num_env, env_left, env_ok;
9020 struct Packet *pktout;
9021 crStateP(ssh2_setup_env_state, ctx);
9026 * Send environment variables.
9028 * Simplest thing here is to send all the requests at once, and
9029 * then wait for a whole bunch of successes or failures.
9035 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9037 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9038 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9039 ssh2_pkt_addstring(pktout, key);
9040 ssh2_pkt_addstring(pktout, val);
9041 ssh2_pkt_send(ssh, pktout);
9046 logeventf(ssh, "Sent %d environment variables", s->num_env);
9051 s->env_left = s->num_env;
9053 while (s->env_left > 0) {
9054 /* Wait to be called back with either a response packet,
9055 * or NULL meaning clean up and free our data */
9057 if (!pktin) goto out;
9058 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9063 if (s->env_ok == s->num_env) {
9064 logevent("All environment variables successfully set");
9065 } else if (s->env_ok == 0) {
9066 logevent("All environment variables refused");
9067 c_write_str(ssh, "Server refused to set environment variables\r\n");
9069 logeventf(ssh, "%d environment variables refused",
9070 s->num_env - s->env_ok);
9071 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9079 * Handle the SSH-2 userauth and connection layers.
9081 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9083 do_ssh2_authconn(ssh, NULL, 0, pktin);
9086 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9090 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9093 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9094 struct Packet *pktin)
9096 struct do_ssh2_authconn_state {
9100 AUTH_TYPE_PUBLICKEY,
9101 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9102 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9104 AUTH_TYPE_GSSAPI, /* always QUIET */
9105 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9106 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9108 int done_service_req;
9109 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9110 int tried_pubkey_config, done_agent;
9115 int kbd_inter_refused;
9116 int we_are_in, userauth_success;
9117 prompts_t *cur_prompt;
9122 void *publickey_blob;
9123 int publickey_bloblen;
9124 int privatekey_available, privatekey_encrypted;
9125 char *publickey_algorithm;
9126 char *publickey_comment;
9127 unsigned char agent_request[5], *agent_response, *agentp;
9128 int agent_responselen;
9129 unsigned char *pkblob_in_agent;
9131 char *pkblob, *alg, *commentp;
9132 int pklen, alglen, commentlen;
9133 int siglen, retlen, len;
9134 char *q, *agentreq, *ret;
9135 struct Packet *pktout;
9138 struct ssh_gss_library *gsslib;
9139 Ssh_gss_ctx gss_ctx;
9140 Ssh_gss_buf gss_buf;
9141 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9142 Ssh_gss_name gss_srv_name;
9143 Ssh_gss_stat gss_stat;
9146 crState(do_ssh2_authconn_state);
9150 /* Register as a handler for all the messages this coroutine handles. */
9151 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9152 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9153 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9154 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9155 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9156 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9157 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9158 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9159 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9160 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9161 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9162 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9163 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9164 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9165 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9166 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9167 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9168 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9169 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9170 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9172 s->done_service_req = FALSE;
9173 s->we_are_in = s->userauth_success = FALSE;
9174 s->agent_response = NULL;
9176 s->tried_gssapi = FALSE;
9179 if (!ssh->bare_connection) {
9180 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9182 * Request userauth protocol, and await a response to it.
9184 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9185 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9186 ssh2_pkt_send(ssh, s->pktout);
9187 crWaitUntilV(pktin);
9188 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9189 s->done_service_req = TRUE;
9191 if (!s->done_service_req) {
9193 * Request connection protocol directly, without authentication.
9195 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9196 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9197 ssh2_pkt_send(ssh, s->pktout);
9198 crWaitUntilV(pktin);
9199 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9200 s->we_are_in = TRUE; /* no auth required */
9202 bombout(("Server refused service request"));
9207 s->we_are_in = TRUE;
9210 /* Arrange to be able to deal with any BANNERs that come in.
9211 * (We do this now as packets may come in during the next bit.) */
9212 bufchain_init(&ssh->banner);
9213 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9214 ssh2_msg_userauth_banner;
9217 * Misc one-time setup for authentication.
9219 s->publickey_blob = NULL;
9220 if (!s->we_are_in) {
9223 * Load the public half of any configured public key file
9226 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9227 if (!filename_is_null(s->keyfile)) {
9229 logeventf(ssh, "Reading key file \"%.150s\"",
9230 filename_to_str(s->keyfile));
9231 keytype = key_type(s->keyfile);
9232 if (keytype == SSH_KEYTYPE_SSH2 ||
9233 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9234 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9237 ssh2_userkey_loadpub(s->keyfile,
9238 &s->publickey_algorithm,
9239 &s->publickey_bloblen,
9240 &s->publickey_comment, &error);
9241 if (s->publickey_blob) {
9242 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9243 if (!s->privatekey_available)
9244 logeventf(ssh, "Key file contains public key only");
9245 s->privatekey_encrypted =
9246 ssh2_userkey_encrypted(s->keyfile, NULL);
9249 logeventf(ssh, "Unable to load key (%s)",
9251 msgbuf = dupprintf("Unable to load key file "
9252 "\"%.150s\" (%s)\r\n",
9253 filename_to_str(s->keyfile),
9255 c_write_str(ssh, msgbuf);
9260 logeventf(ssh, "Unable to use this key file (%s)",
9261 key_type_to_str(keytype));
9262 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9264 filename_to_str(s->keyfile),
9265 key_type_to_str(keytype));
9266 c_write_str(ssh, msgbuf);
9268 s->publickey_blob = NULL;
9273 * Find out about any keys Pageant has (but if there's a
9274 * public key configured, filter out all others).
9277 s->agent_response = NULL;
9278 s->pkblob_in_agent = NULL;
9279 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9283 logevent("Pageant is running. Requesting keys.");
9285 /* Request the keys held by the agent. */
9286 PUT_32BIT(s->agent_request, 1);
9287 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9288 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9289 ssh_agent_callback, ssh)) {
9293 bombout(("Unexpected data from server while"
9294 " waiting for agent response"));
9297 } while (pktin || inlen > 0);
9298 r = ssh->agent_response;
9299 s->agent_responselen = ssh->agent_response_len;
9301 s->agent_response = (unsigned char *) r;
9302 if (s->agent_response && s->agent_responselen >= 5 &&
9303 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9306 p = s->agent_response + 5;
9307 s->nkeys = toint(GET_32BIT(p));
9310 * Vet the Pageant response to ensure that the key
9311 * count and blob lengths make sense.
9314 logeventf(ssh, "Pageant response contained a negative"
9315 " key count %d", s->nkeys);
9317 goto done_agent_query;
9319 unsigned char *q = p + 4;
9320 int lenleft = s->agent_responselen - 5 - 4;
9322 for (keyi = 0; keyi < s->nkeys; keyi++) {
9323 int bloblen, commentlen;
9325 logeventf(ssh, "Pageant response was truncated");
9327 goto done_agent_query;
9329 bloblen = toint(GET_32BIT(q));
9330 if (bloblen < 0 || bloblen > lenleft) {
9331 logeventf(ssh, "Pageant response was truncated");
9333 goto done_agent_query;
9335 lenleft -= 4 + bloblen;
9337 commentlen = toint(GET_32BIT(q));
9338 if (commentlen < 0 || commentlen > lenleft) {
9339 logeventf(ssh, "Pageant response was truncated");
9341 goto done_agent_query;
9343 lenleft -= 4 + commentlen;
9344 q += 4 + commentlen;
9349 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9350 if (s->publickey_blob) {
9351 /* See if configured key is in agent. */
9352 for (keyi = 0; keyi < s->nkeys; keyi++) {
9353 s->pklen = toint(GET_32BIT(p));
9354 if (s->pklen == s->publickey_bloblen &&
9355 !memcmp(p+4, s->publickey_blob,
9356 s->publickey_bloblen)) {
9357 logeventf(ssh, "Pageant key #%d matches "
9358 "configured key file", keyi);
9360 s->pkblob_in_agent = p;
9364 p += toint(GET_32BIT(p)) + 4; /* comment */
9366 if (!s->pkblob_in_agent) {
9367 logevent("Configured key file not in Pageant");
9372 logevent("Failed to get reply from Pageant");
9380 * We repeat this whole loop, including the username prompt,
9381 * until we manage a successful authentication. If the user
9382 * types the wrong _password_, they can be sent back to the
9383 * beginning to try another username, if this is configured on.
9384 * (If they specify a username in the config, they are never
9385 * asked, even if they do give a wrong password.)
9387 * I think this best serves the needs of
9389 * - the people who have no configuration, no keys, and just
9390 * want to try repeated (username,password) pairs until they
9391 * type both correctly
9393 * - people who have keys and configuration but occasionally
9394 * need to fall back to passwords
9396 * - people with a key held in Pageant, who might not have
9397 * logged in to a particular machine before; so they want to
9398 * type a username, and then _either_ their key will be
9399 * accepted, _or_ they will type a password. If they mistype
9400 * the username they will want to be able to get back and
9403 s->got_username = FALSE;
9404 while (!s->we_are_in) {
9408 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9410 * We got a username last time round this loop, and
9411 * with change_username turned off we don't try to get
9414 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9415 int ret; /* need not be kept over crReturn */
9416 s->cur_prompt = new_prompts(ssh->frontend);
9417 s->cur_prompt->to_server = TRUE;
9418 s->cur_prompt->name = dupstr("SSH login name");
9419 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9420 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9423 crWaitUntilV(!pktin);
9424 ret = get_userpass_input(s->cur_prompt, in, inlen);
9429 * get_userpass_input() failed to get a username.
9432 free_prompts(s->cur_prompt);
9433 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9436 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9437 free_prompts(s->cur_prompt);
9440 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9441 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9442 c_write_str(ssh, stuff);
9446 s->got_username = TRUE;
9449 * Send an authentication request using method "none": (a)
9450 * just in case it succeeds, and (b) so that we know what
9451 * authentication methods we can usefully try next.
9453 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9455 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9456 ssh2_pkt_addstring(s->pktout, ssh->username);
9457 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9458 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9459 ssh2_pkt_send(ssh, s->pktout);
9460 s->type = AUTH_TYPE_NONE;
9462 s->we_are_in = FALSE;
9464 s->tried_pubkey_config = FALSE;
9465 s->kbd_inter_refused = FALSE;
9467 /* Reset agent request state. */
9468 s->done_agent = FALSE;
9469 if (s->agent_response) {
9470 if (s->pkblob_in_agent) {
9471 s->agentp = s->pkblob_in_agent;
9473 s->agentp = s->agent_response + 5 + 4;
9479 char *methods = NULL;
9483 * Wait for the result of the last authentication request.
9486 crWaitUntilV(pktin);
9488 * Now is a convenient point to spew any banner material
9489 * that we've accumulated. (This should ensure that when
9490 * we exit the auth loop, we haven't any left to deal
9494 int size = bufchain_size(&ssh->banner);
9496 * Don't show the banner if we're operating in
9497 * non-verbose non-interactive mode. (It's probably
9498 * a script, which means nobody will read the
9499 * banner _anyway_, and moreover the printing of
9500 * the banner will screw up processing on the
9501 * output of (say) plink.)
9503 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9504 char *banner = snewn(size, char);
9505 bufchain_fetch(&ssh->banner, banner, size);
9506 c_write_untrusted(ssh, banner, size);
9509 bufchain_clear(&ssh->banner);
9511 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9512 logevent("Access granted");
9513 s->we_are_in = s->userauth_success = TRUE;
9517 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9518 bombout(("Strange packet received during authentication: "
9519 "type %d", pktin->type));
9526 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9527 * we can look at the string in it and know what we can
9528 * helpfully try next.
9530 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9531 ssh_pkt_getstring(pktin, &methods, &methlen);
9532 if (!ssh2_pkt_getbool(pktin)) {
9534 * We have received an unequivocal Access
9535 * Denied. This can translate to a variety of
9536 * messages, or no message at all.
9538 * For forms of authentication which are attempted
9539 * implicitly, by which I mean without printing
9540 * anything in the window indicating that we're
9541 * trying them, we should never print 'Access
9544 * If we do print a message saying that we're
9545 * attempting some kind of authentication, it's OK
9546 * to print a followup message saying it failed -
9547 * but the message may sometimes be more specific
9548 * than simply 'Access denied'.
9550 * Additionally, if we'd just tried password
9551 * authentication, we should break out of this
9552 * whole loop so as to go back to the username
9553 * prompt (iff we're configured to allow
9554 * username change attempts).
9556 if (s->type == AUTH_TYPE_NONE) {
9558 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9559 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9560 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9561 c_write_str(ssh, "Server refused our key\r\n");
9562 logevent("Server refused our key");
9563 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9564 /* This _shouldn't_ happen except by a
9565 * protocol bug causing client and server to
9566 * disagree on what is a correct signature. */
9567 c_write_str(ssh, "Server refused public-key signature"
9568 " despite accepting key!\r\n");
9569 logevent("Server refused public-key signature"
9570 " despite accepting key!");
9571 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9572 /* quiet, so no c_write */
9573 logevent("Server refused keyboard-interactive authentication");
9574 } else if (s->type==AUTH_TYPE_GSSAPI) {
9575 /* always quiet, so no c_write */
9576 /* also, the code down in the GSSAPI block has
9577 * already logged this in the Event Log */
9578 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9579 logevent("Keyboard-interactive authentication failed");
9580 c_write_str(ssh, "Access denied\r\n");
9582 assert(s->type == AUTH_TYPE_PASSWORD);
9583 logevent("Password authentication failed");
9584 c_write_str(ssh, "Access denied\r\n");
9586 if (conf_get_int(ssh->conf, CONF_change_username)) {
9587 /* XXX perhaps we should allow
9588 * keyboard-interactive to do this too? */
9589 s->we_are_in = FALSE;
9594 c_write_str(ssh, "Further authentication required\r\n");
9595 logevent("Further authentication required");
9599 in_commasep_string("publickey", methods, methlen);
9601 in_commasep_string("password", methods, methlen);
9602 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9603 in_commasep_string("keyboard-interactive", methods, methlen);
9605 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9606 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9607 /* Try loading the GSS libraries and see if we
9610 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9611 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9613 /* No point in even bothering to try to load the
9614 * GSS libraries, if the user configuration and
9615 * server aren't both prepared to attempt GSSAPI
9616 * auth in the first place. */
9617 s->can_gssapi = FALSE;
9622 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9624 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9627 * Attempt public-key authentication using a key from Pageant.
9630 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9632 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9634 /* Unpack key from agent response */
9635 s->pklen = toint(GET_32BIT(s->agentp));
9637 s->pkblob = (char *)s->agentp;
9638 s->agentp += s->pklen;
9639 s->alglen = toint(GET_32BIT(s->pkblob));
9640 s->alg = s->pkblob + 4;
9641 s->commentlen = toint(GET_32BIT(s->agentp));
9643 s->commentp = (char *)s->agentp;
9644 s->agentp += s->commentlen;
9645 /* s->agentp now points at next key, if any */
9647 /* See if server will accept it */
9648 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9649 ssh2_pkt_addstring(s->pktout, ssh->username);
9650 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9651 /* service requested */
9652 ssh2_pkt_addstring(s->pktout, "publickey");
9654 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9655 ssh2_pkt_addstring_start(s->pktout);
9656 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9657 ssh2_pkt_addstring_start(s->pktout);
9658 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9659 ssh2_pkt_send(ssh, s->pktout);
9660 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9662 crWaitUntilV(pktin);
9663 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9665 /* Offer of key refused. */
9672 if (flags & FLAG_VERBOSE) {
9673 c_write_str(ssh, "Authenticating with "
9675 c_write(ssh, s->commentp, s->commentlen);
9676 c_write_str(ssh, "\" from agent\r\n");
9680 * Server is willing to accept the key.
9681 * Construct a SIGN_REQUEST.
9683 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9684 ssh2_pkt_addstring(s->pktout, ssh->username);
9685 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9686 /* service requested */
9687 ssh2_pkt_addstring(s->pktout, "publickey");
9689 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9690 ssh2_pkt_addstring_start(s->pktout);
9691 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9692 ssh2_pkt_addstring_start(s->pktout);
9693 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9695 /* Ask agent for signature. */
9696 s->siglen = s->pktout->length - 5 + 4 +
9697 ssh->v2_session_id_len;
9698 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9700 s->len = 1; /* message type */
9701 s->len += 4 + s->pklen; /* key blob */
9702 s->len += 4 + s->siglen; /* data to sign */
9703 s->len += 4; /* flags */
9704 s->agentreq = snewn(4 + s->len, char);
9705 PUT_32BIT(s->agentreq, s->len);
9706 s->q = s->agentreq + 4;
9707 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9708 PUT_32BIT(s->q, s->pklen);
9710 memcpy(s->q, s->pkblob, s->pklen);
9712 PUT_32BIT(s->q, s->siglen);
9714 /* Now the data to be signed... */
9715 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9716 PUT_32BIT(s->q, ssh->v2_session_id_len);
9719 memcpy(s->q, ssh->v2_session_id,
9720 ssh->v2_session_id_len);
9721 s->q += ssh->v2_session_id_len;
9722 memcpy(s->q, s->pktout->data + 5,
9723 s->pktout->length - 5);
9724 s->q += s->pktout->length - 5;
9725 /* And finally the (zero) flags word. */
9727 if (!agent_query(s->agentreq, s->len + 4,
9729 ssh_agent_callback, ssh)) {
9733 bombout(("Unexpected data from server"
9734 " while waiting for agent"
9738 } while (pktin || inlen > 0);
9739 vret = ssh->agent_response;
9740 s->retlen = ssh->agent_response_len;
9745 if (s->retlen >= 9 &&
9746 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9747 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9748 logevent("Sending Pageant's response");
9749 ssh2_add_sigblob(ssh, s->pktout,
9750 s->pkblob, s->pklen,
9752 GET_32BIT(s->ret + 5));
9753 ssh2_pkt_send(ssh, s->pktout);
9754 s->type = AUTH_TYPE_PUBLICKEY;
9756 /* FIXME: less drastic response */
9757 bombout(("Pageant failed to answer challenge"));
9763 /* Do we have any keys left to try? */
9764 if (s->pkblob_in_agent) {
9765 s->done_agent = TRUE;
9766 s->tried_pubkey_config = TRUE;
9769 if (s->keyi >= s->nkeys)
9770 s->done_agent = TRUE;
9773 } else if (s->can_pubkey && s->publickey_blob &&
9774 s->privatekey_available && !s->tried_pubkey_config) {
9776 struct ssh2_userkey *key; /* not live over crReturn */
9777 char *passphrase; /* not live over crReturn */
9779 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9781 s->tried_pubkey_config = TRUE;
9784 * Try the public key supplied in the configuration.
9786 * First, offer the public blob to see if the server is
9787 * willing to accept it.
9789 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9790 ssh2_pkt_addstring(s->pktout, ssh->username);
9791 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9792 /* service requested */
9793 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9794 ssh2_pkt_addbool(s->pktout, FALSE);
9795 /* no signature included */
9796 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9797 ssh2_pkt_addstring_start(s->pktout);
9798 ssh2_pkt_addstring_data(s->pktout,
9799 (char *)s->publickey_blob,
9800 s->publickey_bloblen);
9801 ssh2_pkt_send(ssh, s->pktout);
9802 logevent("Offered public key");
9804 crWaitUntilV(pktin);
9805 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9806 /* Key refused. Give up. */
9807 s->gotit = TRUE; /* reconsider message next loop */
9808 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9809 continue; /* process this new message */
9811 logevent("Offer of public key accepted");
9814 * Actually attempt a serious authentication using
9817 if (flags & FLAG_VERBOSE) {
9818 c_write_str(ssh, "Authenticating with public key \"");
9819 c_write_str(ssh, s->publickey_comment);
9820 c_write_str(ssh, "\"\r\n");
9824 const char *error; /* not live over crReturn */
9825 if (s->privatekey_encrypted) {
9827 * Get a passphrase from the user.
9829 int ret; /* need not be kept over crReturn */
9830 s->cur_prompt = new_prompts(ssh->frontend);
9831 s->cur_prompt->to_server = FALSE;
9832 s->cur_prompt->name = dupstr("SSH key passphrase");
9833 add_prompt(s->cur_prompt,
9834 dupprintf("Passphrase for key \"%.100s\": ",
9835 s->publickey_comment),
9837 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9840 crWaitUntilV(!pktin);
9841 ret = get_userpass_input(s->cur_prompt,
9846 /* Failed to get a passphrase. Terminate. */
9847 free_prompts(s->cur_prompt);
9848 ssh_disconnect(ssh, NULL,
9849 "Unable to authenticate",
9850 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9855 dupstr(s->cur_prompt->prompts[0]->result);
9856 free_prompts(s->cur_prompt);
9858 passphrase = NULL; /* no passphrase needed */
9862 * Try decrypting the key.
9864 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9865 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9867 /* burn the evidence */
9868 smemclr(passphrase, strlen(passphrase));
9871 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9873 (key == SSH2_WRONG_PASSPHRASE)) {
9874 c_write_str(ssh, "Wrong passphrase\r\n");
9876 /* and loop again */
9878 c_write_str(ssh, "Unable to load private key (");
9879 c_write_str(ssh, error);
9880 c_write_str(ssh, ")\r\n");
9882 break; /* try something else */
9888 unsigned char *pkblob, *sigblob, *sigdata;
9889 int pkblob_len, sigblob_len, sigdata_len;
9893 * We have loaded the private key and the server
9894 * has announced that it's willing to accept it.
9895 * Hallelujah. Generate a signature and send it.
9897 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9898 ssh2_pkt_addstring(s->pktout, ssh->username);
9899 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9900 /* service requested */
9901 ssh2_pkt_addstring(s->pktout, "publickey");
9903 ssh2_pkt_addbool(s->pktout, TRUE);
9904 /* signature follows */
9905 ssh2_pkt_addstring(s->pktout, key->alg->name);
9906 pkblob = key->alg->public_blob(key->data,
9908 ssh2_pkt_addstring_start(s->pktout);
9909 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9913 * The data to be signed is:
9917 * followed by everything so far placed in the
9920 sigdata_len = s->pktout->length - 5 + 4 +
9921 ssh->v2_session_id_len;
9922 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9924 sigdata = snewn(sigdata_len, unsigned char);
9926 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9927 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9930 memcpy(sigdata+p, ssh->v2_session_id,
9931 ssh->v2_session_id_len);
9932 p += ssh->v2_session_id_len;
9933 memcpy(sigdata+p, s->pktout->data + 5,
9934 s->pktout->length - 5);
9935 p += s->pktout->length - 5;
9936 assert(p == sigdata_len);
9937 sigblob = key->alg->sign(key->data, (char *)sigdata,
9938 sigdata_len, &sigblob_len);
9939 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9940 sigblob, sigblob_len);
9945 ssh2_pkt_send(ssh, s->pktout);
9946 logevent("Sent public key signature");
9947 s->type = AUTH_TYPE_PUBLICKEY;
9948 key->alg->freekey(key->data);
9949 sfree(key->comment);
9954 } else if (s->can_gssapi && !s->tried_gssapi) {
9956 /* GSSAPI Authentication */
9961 s->type = AUTH_TYPE_GSSAPI;
9962 s->tried_gssapi = TRUE;
9964 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9967 * Pick the highest GSS library on the preference
9973 for (i = 0; i < ngsslibs; i++) {
9974 int want_id = conf_get_int_int(ssh->conf,
9975 CONF_ssh_gsslist, i);
9976 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9977 if (ssh->gsslibs->libraries[j].id == want_id) {
9978 s->gsslib = &ssh->gsslibs->libraries[j];
9979 goto got_gsslib; /* double break */
9984 * We always expect to have found something in
9985 * the above loop: we only came here if there
9986 * was at least one viable GSS library, and the
9987 * preference list should always mention
9988 * everything and only change the order.
9993 if (s->gsslib->gsslogmsg)
9994 logevent(s->gsslib->gsslogmsg);
9996 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9997 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9998 ssh2_pkt_addstring(s->pktout, ssh->username);
9999 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10000 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10001 logevent("Attempting GSSAPI authentication");
10003 /* add mechanism info */
10004 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10006 /* number of GSSAPI mechanisms */
10007 ssh2_pkt_adduint32(s->pktout,1);
10009 /* length of OID + 2 */
10010 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10011 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10013 /* length of OID */
10014 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10016 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10017 s->gss_buf.length);
10018 ssh2_pkt_send(ssh, s->pktout);
10019 crWaitUntilV(pktin);
10020 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10021 logevent("GSSAPI authentication request refused");
10025 /* check returned packet ... */
10027 ssh_pkt_getstring(pktin, &data, &len);
10028 s->gss_rcvtok.value = data;
10029 s->gss_rcvtok.length = len;
10030 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10031 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10032 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10033 memcmp((char *)s->gss_rcvtok.value + 2,
10034 s->gss_buf.value,s->gss_buf.length) ) {
10035 logevent("GSSAPI authentication - wrong response from server");
10039 /* now start running */
10040 s->gss_stat = s->gsslib->import_name(s->gsslib,
10043 if (s->gss_stat != SSH_GSS_OK) {
10044 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10045 logevent("GSSAPI import name failed - Bad service name");
10047 logevent("GSSAPI import name failed");
10051 /* fetch TGT into GSS engine */
10052 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10054 if (s->gss_stat != SSH_GSS_OK) {
10055 logevent("GSSAPI authentication failed to get credentials");
10056 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10060 /* initial tokens are empty */
10061 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10062 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10064 /* now enter the loop */
10066 s->gss_stat = s->gsslib->init_sec_context
10070 conf_get_int(ssh->conf, CONF_gssapifwd),
10074 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10075 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10076 logevent("GSSAPI authentication initialisation failed");
10078 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10079 &s->gss_buf) == SSH_GSS_OK) {
10080 logevent(s->gss_buf.value);
10081 sfree(s->gss_buf.value);
10086 logevent("GSSAPI authentication initialised");
10088 /* Client and server now exchange tokens until GSSAPI
10089 * no longer says CONTINUE_NEEDED */
10091 if (s->gss_sndtok.length != 0) {
10092 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10093 ssh_pkt_addstring_start(s->pktout);
10094 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10095 ssh2_pkt_send(ssh, s->pktout);
10096 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10099 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10100 crWaitUntilV(pktin);
10101 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10102 logevent("GSSAPI authentication - bad server response");
10103 s->gss_stat = SSH_GSS_FAILURE;
10106 ssh_pkt_getstring(pktin, &data, &len);
10107 s->gss_rcvtok.value = data;
10108 s->gss_rcvtok.length = len;
10110 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10112 if (s->gss_stat != SSH_GSS_OK) {
10113 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10114 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10117 logevent("GSSAPI authentication loop finished OK");
10119 /* Now send the MIC */
10121 s->pktout = ssh2_pkt_init(0);
10122 micoffset = s->pktout->length;
10123 ssh_pkt_addstring_start(s->pktout);
10124 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10125 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10126 ssh_pkt_addstring(s->pktout, ssh->username);
10127 ssh_pkt_addstring(s->pktout, "ssh-connection");
10128 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10130 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10131 s->gss_buf.length = s->pktout->length - micoffset;
10133 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10134 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10135 ssh_pkt_addstring_start(s->pktout);
10136 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10137 ssh2_pkt_send(ssh, s->pktout);
10138 s->gsslib->free_mic(s->gsslib, &mic);
10142 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10143 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10146 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10149 * Keyboard-interactive authentication.
10152 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10154 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10156 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10157 ssh2_pkt_addstring(s->pktout, ssh->username);
10158 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10159 /* service requested */
10160 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10162 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10163 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10164 ssh2_pkt_send(ssh, s->pktout);
10166 logevent("Attempting keyboard-interactive authentication");
10168 crWaitUntilV(pktin);
10169 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10170 /* Server is not willing to do keyboard-interactive
10171 * at all (or, bizarrely but legally, accepts the
10172 * user without actually issuing any prompts).
10173 * Give up on it entirely. */
10175 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10176 s->kbd_inter_refused = TRUE; /* don't try it again */
10181 * Loop while the server continues to send INFO_REQUESTs.
10183 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10185 char *name, *inst, *lang;
10186 int name_len, inst_len, lang_len;
10190 * We've got a fresh USERAUTH_INFO_REQUEST.
10191 * Get the preamble and start building a prompt.
10193 ssh_pkt_getstring(pktin, &name, &name_len);
10194 ssh_pkt_getstring(pktin, &inst, &inst_len);
10195 ssh_pkt_getstring(pktin, &lang, &lang_len);
10196 s->cur_prompt = new_prompts(ssh->frontend);
10197 s->cur_prompt->to_server = TRUE;
10200 * Get any prompt(s) from the packet.
10202 s->num_prompts = ssh_pkt_getuint32(pktin);
10203 for (i = 0; i < s->num_prompts; i++) {
10207 static char noprompt[] =
10208 "<server failed to send prompt>: ";
10210 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10211 echo = ssh2_pkt_getbool(pktin);
10214 prompt_len = lenof(noprompt)-1;
10216 add_prompt(s->cur_prompt,
10217 dupprintf("%.*s", prompt_len, prompt),
10222 /* FIXME: better prefix to distinguish from
10223 * local prompts? */
10224 s->cur_prompt->name =
10225 dupprintf("SSH server: %.*s", name_len, name);
10226 s->cur_prompt->name_reqd = TRUE;
10228 s->cur_prompt->name =
10229 dupstr("SSH server authentication");
10230 s->cur_prompt->name_reqd = FALSE;
10232 /* We add a prefix to try to make it clear that a prompt
10233 * has come from the server.
10234 * FIXME: ugly to print "Using..." in prompt _every_
10235 * time round. Can this be done more subtly? */
10236 /* Special case: for reasons best known to themselves,
10237 * some servers send k-i requests with no prompts and
10238 * nothing to display. Keep quiet in this case. */
10239 if (s->num_prompts || name_len || inst_len) {
10240 s->cur_prompt->instruction =
10241 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10242 inst_len ? "\n" : "", inst_len, inst);
10243 s->cur_prompt->instr_reqd = TRUE;
10245 s->cur_prompt->instr_reqd = FALSE;
10249 * Display any instructions, and get the user's
10253 int ret; /* not live over crReturn */
10254 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10257 crWaitUntilV(!pktin);
10258 ret = get_userpass_input(s->cur_prompt, in, inlen);
10263 * Failed to get responses. Terminate.
10265 free_prompts(s->cur_prompt);
10266 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10267 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10274 * Send the response(s) to the server.
10276 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10277 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10278 for (i=0; i < s->num_prompts; i++) {
10279 ssh2_pkt_addstring(s->pktout,
10280 s->cur_prompt->prompts[i]->result);
10282 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10285 * Free the prompts structure from this iteration.
10286 * If there's another, a new one will be allocated
10287 * when we return to the top of this while loop.
10289 free_prompts(s->cur_prompt);
10292 * Get the next packet in case it's another
10295 crWaitUntilV(pktin);
10300 * We should have SUCCESS or FAILURE now.
10304 } else if (s->can_passwd) {
10307 * Plain old password authentication.
10309 int ret; /* not live over crReturn */
10310 int changereq_first_time; /* not live over crReturn */
10312 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10314 s->cur_prompt = new_prompts(ssh->frontend);
10315 s->cur_prompt->to_server = TRUE;
10316 s->cur_prompt->name = dupstr("SSH password");
10317 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10322 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10325 crWaitUntilV(!pktin);
10326 ret = get_userpass_input(s->cur_prompt, in, inlen);
10331 * Failed to get responses. Terminate.
10333 free_prompts(s->cur_prompt);
10334 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10335 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10340 * Squirrel away the password. (We may need it later if
10341 * asked to change it.)
10343 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10344 free_prompts(s->cur_prompt);
10347 * Send the password packet.
10349 * We pad out the password packet to 256 bytes to make
10350 * it harder for an attacker to find the length of the
10353 * Anyone using a password longer than 256 bytes
10354 * probably doesn't have much to worry about from
10355 * people who find out how long their password is!
10357 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10358 ssh2_pkt_addstring(s->pktout, ssh->username);
10359 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10360 /* service requested */
10361 ssh2_pkt_addstring(s->pktout, "password");
10362 ssh2_pkt_addbool(s->pktout, FALSE);
10363 ssh2_pkt_addstring(s->pktout, s->password);
10364 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10365 logevent("Sent password");
10366 s->type = AUTH_TYPE_PASSWORD;
10369 * Wait for next packet, in case it's a password change
10372 crWaitUntilV(pktin);
10373 changereq_first_time = TRUE;
10375 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10378 * We're being asked for a new password
10379 * (perhaps not for the first time).
10380 * Loop until the server accepts it.
10383 int got_new = FALSE; /* not live over crReturn */
10384 char *prompt; /* not live over crReturn */
10385 int prompt_len; /* not live over crReturn */
10389 if (changereq_first_time)
10390 msg = "Server requested password change";
10392 msg = "Server rejected new password";
10394 c_write_str(ssh, msg);
10395 c_write_str(ssh, "\r\n");
10398 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10400 s->cur_prompt = new_prompts(ssh->frontend);
10401 s->cur_prompt->to_server = TRUE;
10402 s->cur_prompt->name = dupstr("New SSH password");
10403 s->cur_prompt->instruction =
10404 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10405 s->cur_prompt->instr_reqd = TRUE;
10407 * There's no explicit requirement in the protocol
10408 * for the "old" passwords in the original and
10409 * password-change messages to be the same, and
10410 * apparently some Cisco kit supports password change
10411 * by the user entering a blank password originally
10412 * and the real password subsequently, so,
10413 * reluctantly, we prompt for the old password again.
10415 * (On the other hand, some servers don't even bother
10416 * to check this field.)
10418 add_prompt(s->cur_prompt,
10419 dupstr("Current password (blank for previously entered password): "),
10421 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10423 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10427 * Loop until the user manages to enter the same
10432 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10435 crWaitUntilV(!pktin);
10436 ret = get_userpass_input(s->cur_prompt, in, inlen);
10441 * Failed to get responses. Terminate.
10443 /* burn the evidence */
10444 free_prompts(s->cur_prompt);
10445 smemclr(s->password, strlen(s->password));
10446 sfree(s->password);
10447 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10448 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10454 * If the user specified a new original password
10455 * (IYSWIM), overwrite any previously specified
10457 * (A side effect is that the user doesn't have to
10458 * re-enter it if they louse up the new password.)
10460 if (s->cur_prompt->prompts[0]->result[0]) {
10461 smemclr(s->password, strlen(s->password));
10462 /* burn the evidence */
10463 sfree(s->password);
10465 dupstr(s->cur_prompt->prompts[0]->result);
10469 * Check the two new passwords match.
10471 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10472 s->cur_prompt->prompts[2]->result)
10475 /* They don't. Silly user. */
10476 c_write_str(ssh, "Passwords do not match\r\n");
10481 * Send the new password (along with the old one).
10482 * (see above for padding rationale)
10484 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10485 ssh2_pkt_addstring(s->pktout, ssh->username);
10486 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10487 /* service requested */
10488 ssh2_pkt_addstring(s->pktout, "password");
10489 ssh2_pkt_addbool(s->pktout, TRUE);
10490 ssh2_pkt_addstring(s->pktout, s->password);
10491 ssh2_pkt_addstring(s->pktout,
10492 s->cur_prompt->prompts[1]->result);
10493 free_prompts(s->cur_prompt);
10494 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10495 logevent("Sent new password");
10498 * Now see what the server has to say about it.
10499 * (If it's CHANGEREQ again, it's not happy with the
10502 crWaitUntilV(pktin);
10503 changereq_first_time = FALSE;
10508 * We need to reexamine the current pktin at the top
10509 * of the loop. Either:
10510 * - we weren't asked to change password at all, in
10511 * which case it's a SUCCESS or FAILURE with the
10513 * - we sent a new password, and the server was
10514 * either OK with it (SUCCESS or FAILURE w/partial
10515 * success) or unhappy with the _old_ password
10516 * (FAILURE w/o partial success)
10517 * In any of these cases, we go back to the top of
10518 * the loop and start again.
10523 * We don't need the old password any more, in any
10524 * case. Burn the evidence.
10526 smemclr(s->password, strlen(s->password));
10527 sfree(s->password);
10530 char *str = dupprintf("No supported authentication methods available"
10531 " (server sent: %.*s)",
10534 ssh_disconnect(ssh, str,
10535 "No supported authentication methods available",
10536 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10546 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10548 /* Clear up various bits and pieces from authentication. */
10549 if (s->publickey_blob) {
10550 sfree(s->publickey_algorithm);
10551 sfree(s->publickey_blob);
10552 sfree(s->publickey_comment);
10554 if (s->agent_response)
10555 sfree(s->agent_response);
10557 if (s->userauth_success && !ssh->bare_connection) {
10559 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10560 * packets since. Signal the transport layer to consider enacting
10561 * delayed compression.
10563 * (Relying on we_are_in is not sufficient, as
10564 * draft-miller-secsh-compression-delayed is quite clear that it
10565 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10566 * become set for other reasons.)
10568 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10571 ssh->channels = newtree234(ssh_channelcmp);
10574 * Set up handlers for some connection protocol messages, so we
10575 * don't have to handle them repeatedly in this coroutine.
10577 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10578 ssh2_msg_channel_window_adjust;
10579 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10580 ssh2_msg_global_request;
10583 * Create the main session channel.
10585 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10586 ssh->mainchan = NULL;
10588 ssh->mainchan = snew(struct ssh_channel);
10589 ssh->mainchan->ssh = ssh;
10590 ssh_channel_init(ssh->mainchan);
10592 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10594 * Just start a direct-tcpip channel and use it as the main
10597 ssh_send_port_open(ssh->mainchan,
10598 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10599 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10601 ssh->ncmode = TRUE;
10603 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10604 logevent("Opening session as main channel");
10605 ssh2_pkt_send(ssh, s->pktout);
10606 ssh->ncmode = FALSE;
10608 crWaitUntilV(pktin);
10609 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10610 bombout(("Server refused to open channel"));
10612 /* FIXME: error data comes back in FAILURE packet */
10614 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10615 bombout(("Server's channel confirmation cited wrong channel"));
10618 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10619 ssh->mainchan->halfopen = FALSE;
10620 ssh->mainchan->type = CHAN_MAINSESSION;
10621 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10622 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10623 update_specials_menu(ssh->frontend);
10624 logevent("Opened main channel");
10628 * Now we have a channel, make dispatch table entries for
10629 * general channel-based messages.
10631 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10632 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10633 ssh2_msg_channel_data;
10634 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10635 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10636 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10637 ssh2_msg_channel_open_confirmation;
10638 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10639 ssh2_msg_channel_open_failure;
10640 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10641 ssh2_msg_channel_request;
10642 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10643 ssh2_msg_channel_open;
10644 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10645 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10648 * Now the connection protocol is properly up and running, with
10649 * all those dispatch table entries, so it's safe to let
10650 * downstreams start trying to open extra channels through us.
10652 if (ssh->connshare)
10653 share_activate(ssh->connshare, ssh->v_s);
10655 if (ssh->mainchan && ssh_is_simple(ssh)) {
10657 * This message indicates to the server that we promise
10658 * not to try to run any other channel in parallel with
10659 * this one, so it's safe for it to advertise a very large
10660 * window and leave the flow control to TCP.
10662 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10663 "simple@putty.projects.tartarus.org",
10665 ssh2_pkt_send(ssh, s->pktout);
10669 * Enable port forwardings.
10671 ssh_setup_portfwd(ssh, ssh->conf);
10673 if (ssh->mainchan && !ssh->ncmode) {
10675 * Send the CHANNEL_REQUESTS for the main session channel.
10676 * Each one is handled by its own little asynchronous
10680 /* Potentially enable X11 forwarding. */
10681 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10683 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10685 if (!ssh->x11disp) {
10686 /* FIXME: return an error message from x11_setup_display */
10687 logevent("X11 forwarding not enabled: unable to"
10688 " initialise X display");
10690 ssh->x11auth = x11_invent_fake_auth
10691 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10692 ssh->x11auth->disp = ssh->x11disp;
10694 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10698 /* Potentially enable agent forwarding. */
10699 if (ssh_agent_forwarding_permitted(ssh))
10700 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10702 /* Now allocate a pty for the session. */
10703 if (!conf_get_int(ssh->conf, CONF_nopty))
10704 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10706 /* Send environment variables. */
10707 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10710 * Start a shell or a remote command. We may have to attempt
10711 * this twice if the config data has provided a second choice
10718 if (ssh->fallback_cmd) {
10719 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10720 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10722 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10723 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10727 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10728 ssh2_response_authconn, NULL);
10729 ssh2_pkt_addstring(s->pktout, cmd);
10731 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10732 ssh2_response_authconn, NULL);
10733 ssh2_pkt_addstring(s->pktout, cmd);
10735 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10736 ssh2_response_authconn, NULL);
10738 ssh2_pkt_send(ssh, s->pktout);
10740 crWaitUntilV(pktin);
10742 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10743 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10744 bombout(("Unexpected response to shell/command request:"
10745 " packet type %d", pktin->type));
10749 * We failed to start the command. If this is the
10750 * fallback command, we really are finished; if it's
10751 * not, and if the fallback command exists, try falling
10752 * back to it before complaining.
10754 if (!ssh->fallback_cmd &&
10755 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10756 logevent("Primary command failed; attempting fallback");
10757 ssh->fallback_cmd = TRUE;
10760 bombout(("Server refused to start a shell/command"));
10763 logevent("Started a shell/command");
10768 ssh->editing = ssh->echoing = TRUE;
10771 ssh->state = SSH_STATE_SESSION;
10772 if (ssh->size_needed)
10773 ssh_size(ssh, ssh->term_width, ssh->term_height);
10774 if (ssh->eof_needed)
10775 ssh_special(ssh, TS_EOF);
10781 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10789 * _All_ the connection-layer packets we expect to
10790 * receive are now handled by the dispatch table.
10791 * Anything that reaches here must be bogus.
10794 bombout(("Strange packet received: type %d", pktin->type));
10796 } else if (ssh->mainchan) {
10798 * We have spare data. Add it to the channel buffer.
10800 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10808 * Handlers for SSH-2 messages that might arrive at any moment.
10810 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10812 /* log reason code in disconnect message */
10814 int reason, msglen;
10816 reason = ssh_pkt_getuint32(pktin);
10817 ssh_pkt_getstring(pktin, &msg, &msglen);
10819 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10820 buf = dupprintf("Received disconnect message (%s)",
10821 ssh2_disconnect_reasons[reason]);
10823 buf = dupprintf("Received disconnect message (unknown"
10824 " type %d)", reason);
10828 buf = dupprintf("Disconnection message text: %.*s",
10829 msglen, NULLTOEMPTY(msg));
10831 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10833 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10834 ssh2_disconnect_reasons[reason] : "unknown",
10835 msglen, NULLTOEMPTY(msg)));
10839 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10841 /* log the debug message */
10845 /* XXX maybe we should actually take notice of the return value */
10846 ssh2_pkt_getbool(pktin);
10847 ssh_pkt_getstring(pktin, &msg, &msglen);
10849 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10852 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10854 do_ssh2_transport(ssh, NULL, 0, pktin);
10858 * Called if we receive a packet that isn't allowed by the protocol.
10859 * This only applies to packets whose meaning PuTTY understands.
10860 * Entirely unknown packets are handled below.
10862 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10864 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10865 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10867 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10871 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10873 struct Packet *pktout;
10874 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10875 ssh2_pkt_adduint32(pktout, pktin->sequence);
10877 * UNIMPLEMENTED messages MUST appear in the same order as the
10878 * messages they respond to. Hence, never queue them.
10880 ssh2_pkt_send_noqueue(ssh, pktout);
10884 * Handle the top-level SSH-2 protocol.
10886 static void ssh2_protocol_setup(Ssh ssh)
10891 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10893 for (i = 0; i < 256; i++)
10894 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10897 * Initially, we only accept transport messages (and a few generic
10898 * ones). do_ssh2_authconn will add more when it starts.
10899 * Messages that are understood but not currently acceptable go to
10900 * ssh2_msg_unexpected.
10902 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10903 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10904 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10905 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10906 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10907 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10908 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10909 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10910 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10911 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10912 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10913 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10914 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10915 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10916 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10917 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10918 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10919 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10920 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10921 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10922 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10923 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10924 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10925 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10926 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10927 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10928 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10929 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10930 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10931 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10932 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10933 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10934 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10937 * These messages have a special handler from the start.
10939 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10940 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10941 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10944 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10949 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10951 for (i = 0; i < 256; i++)
10952 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10955 * Initially, we set all ssh-connection messages to 'unexpected';
10956 * do_ssh2_authconn will fill things in properly. We also handle a
10957 * couple of messages from the transport protocol which aren't
10958 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10961 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10962 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10963 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10964 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10965 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10966 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10967 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10968 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10969 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10970 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10971 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10972 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10973 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10974 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10976 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10979 * These messages have a special handler from the start.
10981 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10982 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10983 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10986 static void ssh2_timer(void *ctx, unsigned long now)
10988 Ssh ssh = (Ssh)ctx;
10990 if (ssh->state == SSH_STATE_CLOSED)
10993 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10994 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10995 now == ssh->next_rekey) {
10996 do_ssh2_transport(ssh, "timeout", -1, NULL);
11000 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11001 struct Packet *pktin)
11003 const unsigned char *in = (const unsigned char *)vin;
11004 if (ssh->state == SSH_STATE_CLOSED)
11008 ssh->incoming_data_size += pktin->encrypted_len;
11009 if (!ssh->kex_in_progress &&
11010 ssh->max_data_size != 0 &&
11011 ssh->incoming_data_size > ssh->max_data_size)
11012 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11016 ssh->packet_dispatch[pktin->type](ssh, pktin);
11017 else if (!ssh->protocol_initial_phase_done)
11018 do_ssh2_transport(ssh, in, inlen, pktin);
11020 do_ssh2_authconn(ssh, in, inlen, pktin);
11023 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11024 struct Packet *pktin)
11026 const unsigned char *in = (const unsigned char *)vin;
11027 if (ssh->state == SSH_STATE_CLOSED)
11031 ssh->packet_dispatch[pktin->type](ssh, pktin);
11033 do_ssh2_authconn(ssh, in, inlen, pktin);
11036 static void ssh_cache_conf_values(Ssh ssh)
11038 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11042 * Called to set up the connection.
11044 * Returns an error message, or NULL on success.
11046 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11048 const char *host, int port, char **realhost,
11049 int nodelay, int keepalive)
11054 ssh = snew(struct ssh_tag);
11055 ssh->conf = conf_copy(conf);
11056 ssh_cache_conf_values(ssh);
11057 ssh->version = 0; /* when not ready yet */
11059 ssh->cipher = NULL;
11060 ssh->v1_cipher_ctx = NULL;
11061 ssh->crcda_ctx = NULL;
11062 ssh->cscipher = NULL;
11063 ssh->cs_cipher_ctx = NULL;
11064 ssh->sccipher = NULL;
11065 ssh->sc_cipher_ctx = NULL;
11067 ssh->cs_mac_ctx = NULL;
11069 ssh->sc_mac_ctx = NULL;
11070 ssh->cscomp = NULL;
11071 ssh->cs_comp_ctx = NULL;
11072 ssh->sccomp = NULL;
11073 ssh->sc_comp_ctx = NULL;
11075 ssh->kex_ctx = NULL;
11076 ssh->hostkey = NULL;
11077 ssh->hostkey_str = NULL;
11078 ssh->exitcode = -1;
11079 ssh->close_expected = FALSE;
11080 ssh->clean_exit = FALSE;
11081 ssh->state = SSH_STATE_PREPACKET;
11082 ssh->size_needed = FALSE;
11083 ssh->eof_needed = FALSE;
11085 ssh->logctx = NULL;
11086 ssh->deferred_send_data = NULL;
11087 ssh->deferred_len = 0;
11088 ssh->deferred_size = 0;
11089 ssh->fallback_cmd = 0;
11090 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11091 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11092 ssh->x11disp = NULL;
11093 ssh->x11auth = NULL;
11094 ssh->x11authtree = newtree234(x11_authcmp);
11095 ssh->v1_compressing = FALSE;
11096 ssh->v2_outgoing_sequence = 0;
11097 ssh->ssh1_rdpkt_crstate = 0;
11098 ssh->ssh2_rdpkt_crstate = 0;
11099 ssh->ssh2_bare_rdpkt_crstate = 0;
11100 ssh->ssh_gotdata_crstate = 0;
11101 ssh->do_ssh1_connection_crstate = 0;
11102 ssh->do_ssh_init_state = NULL;
11103 ssh->do_ssh_connection_init_state = NULL;
11104 ssh->do_ssh1_login_state = NULL;
11105 ssh->do_ssh2_transport_state = NULL;
11106 ssh->do_ssh2_authconn_state = NULL;
11109 ssh->mainchan = NULL;
11110 ssh->throttled_all = 0;
11111 ssh->v1_stdout_throttling = 0;
11113 ssh->queuelen = ssh->queuesize = 0;
11114 ssh->queueing = FALSE;
11115 ssh->qhead = ssh->qtail = NULL;
11116 ssh->deferred_rekey_reason = NULL;
11117 bufchain_init(&ssh->queued_incoming_data);
11118 ssh->frozen = FALSE;
11119 ssh->username = NULL;
11120 ssh->sent_console_eof = FALSE;
11121 ssh->got_pty = FALSE;
11122 ssh->bare_connection = FALSE;
11123 ssh->X11_fwd_enabled = FALSE;
11124 ssh->connshare = NULL;
11125 ssh->attempting_connshare = FALSE;
11126 ssh->session_started = FALSE;
11127 ssh->specials = NULL;
11128 ssh->n_uncert_hostkeys = 0;
11129 ssh->cross_certifying = FALSE;
11131 *backend_handle = ssh;
11134 if (crypto_startup() == 0)
11135 return "Microsoft high encryption pack not installed!";
11138 ssh->frontend = frontend_handle;
11139 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11140 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11142 ssh->channels = NULL;
11143 ssh->rportfwds = NULL;
11144 ssh->portfwds = NULL;
11149 ssh->conn_throttle_count = 0;
11150 ssh->overall_bufsize = 0;
11151 ssh->fallback_cmd = 0;
11153 ssh->protocol = NULL;
11155 ssh->protocol_initial_phase_done = FALSE;
11157 ssh->pinger = NULL;
11159 ssh->incoming_data_size = ssh->outgoing_data_size =
11160 ssh->deferred_data_size = 0L;
11161 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11162 CONF_ssh_rekey_data));
11163 ssh->kex_in_progress = FALSE;
11166 ssh->gsslibs = NULL;
11169 random_ref(); /* do this now - may be needed by sharing setup code */
11171 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11180 static void ssh_free(void *handle)
11182 Ssh ssh = (Ssh) handle;
11183 struct ssh_channel *c;
11184 struct ssh_rportfwd *pf;
11185 struct X11FakeAuth *auth;
11187 if (ssh->v1_cipher_ctx)
11188 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11189 if (ssh->cs_cipher_ctx)
11190 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11191 if (ssh->sc_cipher_ctx)
11192 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11193 if (ssh->cs_mac_ctx)
11194 ssh->csmac->free_context(ssh->cs_mac_ctx);
11195 if (ssh->sc_mac_ctx)
11196 ssh->scmac->free_context(ssh->sc_mac_ctx);
11197 if (ssh->cs_comp_ctx) {
11199 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11201 zlib_compress_cleanup(ssh->cs_comp_ctx);
11203 if (ssh->sc_comp_ctx) {
11205 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11207 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11210 dh_cleanup(ssh->kex_ctx);
11211 sfree(ssh->savedhost);
11213 while (ssh->queuelen-- > 0)
11214 ssh_free_packet(ssh->queue[ssh->queuelen]);
11217 while (ssh->qhead) {
11218 struct queued_handler *qh = ssh->qhead;
11219 ssh->qhead = qh->next;
11222 ssh->qhead = ssh->qtail = NULL;
11224 if (ssh->channels) {
11225 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11228 assert(c->u.x11.xconn != NULL);
11229 x11_close(c->u.x11.xconn);
11231 case CHAN_SOCKDATA:
11232 assert(c->u.pfd.pf != NULL);
11233 pfd_close(c->u.pfd.pf);
11236 if (ssh->version == 2) {
11237 struct outstanding_channel_request *ocr, *nocr;
11238 ocr = c->v.v2.chanreq_head;
11240 ocr->handler(c, NULL, ocr->ctx);
11245 bufchain_clear(&c->v.v2.outbuffer);
11249 freetree234(ssh->channels);
11250 ssh->channels = NULL;
11253 if (ssh->connshare)
11254 sharestate_free(ssh->connshare);
11256 if (ssh->rportfwds) {
11257 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11259 freetree234(ssh->rportfwds);
11260 ssh->rportfwds = NULL;
11262 sfree(ssh->deferred_send_data);
11264 x11_free_display(ssh->x11disp);
11265 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11266 x11_free_fake_auth(auth);
11267 freetree234(ssh->x11authtree);
11268 sfree(ssh->do_ssh_init_state);
11269 sfree(ssh->do_ssh1_login_state);
11270 sfree(ssh->do_ssh2_transport_state);
11271 sfree(ssh->do_ssh2_authconn_state);
11274 sfree(ssh->fullhostname);
11275 sfree(ssh->hostkey_str);
11276 sfree(ssh->specials);
11277 if (ssh->crcda_ctx) {
11278 crcda_free_context(ssh->crcda_ctx);
11279 ssh->crcda_ctx = NULL;
11282 ssh_do_close(ssh, TRUE);
11283 expire_timer_context(ssh);
11285 pinger_free(ssh->pinger);
11286 bufchain_clear(&ssh->queued_incoming_data);
11287 sfree(ssh->username);
11288 conf_free(ssh->conf);
11291 ssh_gss_cleanup(ssh->gsslibs);
11299 * Reconfigure the SSH backend.
11301 static void ssh_reconfig(void *handle, Conf *conf)
11303 Ssh ssh = (Ssh) handle;
11304 const char *rekeying = NULL;
11305 int rekey_mandatory = FALSE;
11306 unsigned long old_max_data_size;
11309 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11311 ssh_setup_portfwd(ssh, conf);
11313 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11314 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11316 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11317 unsigned long now = GETTICKCOUNT();
11319 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11320 rekeying = "timeout shortened";
11322 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11326 old_max_data_size = ssh->max_data_size;
11327 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11328 CONF_ssh_rekey_data));
11329 if (old_max_data_size != ssh->max_data_size &&
11330 ssh->max_data_size != 0) {
11331 if (ssh->outgoing_data_size > ssh->max_data_size ||
11332 ssh->incoming_data_size > ssh->max_data_size)
11333 rekeying = "data limit lowered";
11336 if (conf_get_int(ssh->conf, CONF_compression) !=
11337 conf_get_int(conf, CONF_compression)) {
11338 rekeying = "compression setting changed";
11339 rekey_mandatory = TRUE;
11342 for (i = 0; i < CIPHER_MAX; i++)
11343 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11344 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11345 rekeying = "cipher settings changed";
11346 rekey_mandatory = TRUE;
11348 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11349 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11350 rekeying = "cipher settings changed";
11351 rekey_mandatory = TRUE;
11354 conf_free(ssh->conf);
11355 ssh->conf = conf_copy(conf);
11356 ssh_cache_conf_values(ssh);
11358 if (!ssh->bare_connection && rekeying) {
11359 if (!ssh->kex_in_progress) {
11360 do_ssh2_transport(ssh, rekeying, -1, NULL);
11361 } else if (rekey_mandatory) {
11362 ssh->deferred_rekey_reason = rekeying;
11368 * Called to send data down the SSH connection.
11370 static int ssh_send(void *handle, const char *buf, int len)
11372 Ssh ssh = (Ssh) handle;
11374 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11377 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11379 return ssh_sendbuffer(ssh);
11383 * Called to query the current amount of buffered stdin data.
11385 static int ssh_sendbuffer(void *handle)
11387 Ssh ssh = (Ssh) handle;
11388 int override_value;
11390 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11394 * If the SSH socket itself has backed up, add the total backup
11395 * size on that to any individual buffer on the stdin channel.
11397 override_value = 0;
11398 if (ssh->throttled_all)
11399 override_value = ssh->overall_bufsize;
11401 if (ssh->version == 1) {
11402 return override_value;
11403 } else if (ssh->version == 2) {
11404 if (!ssh->mainchan)
11405 return override_value;
11407 return (override_value +
11408 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11415 * Called to set the size of the window from SSH's POV.
11417 static void ssh_size(void *handle, int width, int height)
11419 Ssh ssh = (Ssh) handle;
11420 struct Packet *pktout;
11422 ssh->term_width = width;
11423 ssh->term_height = height;
11425 switch (ssh->state) {
11426 case SSH_STATE_BEFORE_SIZE:
11427 case SSH_STATE_PREPACKET:
11428 case SSH_STATE_CLOSED:
11429 break; /* do nothing */
11430 case SSH_STATE_INTERMED:
11431 ssh->size_needed = TRUE; /* buffer for later */
11433 case SSH_STATE_SESSION:
11434 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11435 if (ssh->version == 1) {
11436 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11437 PKT_INT, ssh->term_height,
11438 PKT_INT, ssh->term_width,
11439 PKT_INT, 0, PKT_INT, 0, PKT_END);
11440 } else if (ssh->mainchan) {
11441 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11443 ssh2_pkt_adduint32(pktout, ssh->term_width);
11444 ssh2_pkt_adduint32(pktout, ssh->term_height);
11445 ssh2_pkt_adduint32(pktout, 0);
11446 ssh2_pkt_adduint32(pktout, 0);
11447 ssh2_pkt_send(ssh, pktout);
11455 * Return a list of the special codes that make sense in this
11458 static const struct telnet_special *ssh_get_specials(void *handle)
11460 static const struct telnet_special ssh1_ignore_special[] = {
11461 {"IGNORE message", TS_NOP}
11463 static const struct telnet_special ssh2_ignore_special[] = {
11464 {"IGNORE message", TS_NOP},
11466 static const struct telnet_special ssh2_rekey_special[] = {
11467 {"Repeat key exchange", TS_REKEY},
11469 static const struct telnet_special ssh2_session_specials[] = {
11472 /* These are the signal names defined by RFC 4254.
11473 * They include all the ISO C signals, but are a subset of the POSIX
11474 * required signals. */
11475 {"SIGINT (Interrupt)", TS_SIGINT},
11476 {"SIGTERM (Terminate)", TS_SIGTERM},
11477 {"SIGKILL (Kill)", TS_SIGKILL},
11478 {"SIGQUIT (Quit)", TS_SIGQUIT},
11479 {"SIGHUP (Hangup)", TS_SIGHUP},
11480 {"More signals", TS_SUBMENU},
11481 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11482 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11483 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11484 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11485 {NULL, TS_EXITMENU}
11487 static const struct telnet_special specials_end[] = {
11488 {NULL, TS_EXITMENU}
11491 struct telnet_special *specials = NULL;
11492 int nspecials = 0, specialsize = 0;
11494 Ssh ssh = (Ssh) handle;
11496 sfree(ssh->specials);
11498 #define ADD_SPECIALS(name) do \
11500 int len = lenof(name); \
11501 if (nspecials + len > specialsize) { \
11502 specialsize = (nspecials + len) * 5 / 4 + 32; \
11503 specials = sresize(specials, specialsize, struct telnet_special); \
11505 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11506 nspecials += len; \
11509 if (ssh->version == 1) {
11510 /* Don't bother offering IGNORE if we've decided the remote
11511 * won't cope with it, since we wouldn't bother sending it if
11513 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11514 ADD_SPECIALS(ssh1_ignore_special);
11515 } else if (ssh->version == 2) {
11516 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11517 ADD_SPECIALS(ssh2_ignore_special);
11518 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11519 ADD_SPECIALS(ssh2_rekey_special);
11521 ADD_SPECIALS(ssh2_session_specials);
11523 if (ssh->n_uncert_hostkeys) {
11524 static const struct telnet_special uncert_start[] = {
11526 {"Cache new host key type", TS_SUBMENU},
11528 static const struct telnet_special uncert_end[] = {
11529 {NULL, TS_EXITMENU},
11533 ADD_SPECIALS(uncert_start);
11534 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11535 struct telnet_special uncert[1];
11536 const struct ssh_signkey *alg =
11537 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11538 uncert[0].name = alg->name;
11539 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11540 ADD_SPECIALS(uncert);
11542 ADD_SPECIALS(uncert_end);
11544 } /* else we're not ready yet */
11547 ADD_SPECIALS(specials_end);
11549 ssh->specials = specials;
11556 #undef ADD_SPECIALS
11560 * Send special codes. TS_EOF is useful for `plink', so you
11561 * can send an EOF and collect resulting output (e.g. `plink
11564 static void ssh_special(void *handle, Telnet_Special code)
11566 Ssh ssh = (Ssh) handle;
11567 struct Packet *pktout;
11569 if (code == TS_EOF) {
11570 if (ssh->state != SSH_STATE_SESSION) {
11572 * Buffer the EOF in case we are pre-SESSION, so we can
11573 * send it as soon as we reach SESSION.
11575 if (code == TS_EOF)
11576 ssh->eof_needed = TRUE;
11579 if (ssh->version == 1) {
11580 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11581 } else if (ssh->mainchan) {
11582 sshfwd_write_eof(ssh->mainchan);
11583 ssh->send_ok = 0; /* now stop trying to read from stdin */
11585 logevent("Sent EOF message");
11586 } else if (code == TS_PING || code == TS_NOP) {
11587 if (ssh->state == SSH_STATE_CLOSED
11588 || ssh->state == SSH_STATE_PREPACKET) return;
11589 if (ssh->version == 1) {
11590 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11591 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11593 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11594 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11595 ssh2_pkt_addstring_start(pktout);
11596 ssh2_pkt_send_noqueue(ssh, pktout);
11599 } else if (code == TS_REKEY) {
11600 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11601 ssh->version == 2) {
11602 do_ssh2_transport(ssh, "at user request", -1, NULL);
11604 } else if (code >= TS_LOCALSTART) {
11605 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11606 ssh->cross_certifying = TRUE;
11607 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11608 ssh->version == 2) {
11609 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11611 } else if (code == TS_BRK) {
11612 if (ssh->state == SSH_STATE_CLOSED
11613 || ssh->state == SSH_STATE_PREPACKET) return;
11614 if (ssh->version == 1) {
11615 logevent("Unable to send BREAK signal in SSH-1");
11616 } else if (ssh->mainchan) {
11617 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11618 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11619 ssh2_pkt_send(ssh, pktout);
11622 /* Is is a POSIX signal? */
11623 const char *signame = NULL;
11624 if (code == TS_SIGABRT) signame = "ABRT";
11625 if (code == TS_SIGALRM) signame = "ALRM";
11626 if (code == TS_SIGFPE) signame = "FPE";
11627 if (code == TS_SIGHUP) signame = "HUP";
11628 if (code == TS_SIGILL) signame = "ILL";
11629 if (code == TS_SIGINT) signame = "INT";
11630 if (code == TS_SIGKILL) signame = "KILL";
11631 if (code == TS_SIGPIPE) signame = "PIPE";
11632 if (code == TS_SIGQUIT) signame = "QUIT";
11633 if (code == TS_SIGSEGV) signame = "SEGV";
11634 if (code == TS_SIGTERM) signame = "TERM";
11635 if (code == TS_SIGUSR1) signame = "USR1";
11636 if (code == TS_SIGUSR2) signame = "USR2";
11637 /* The SSH-2 protocol does in principle support arbitrary named
11638 * signals, including signame@domain, but we don't support those. */
11640 /* It's a signal. */
11641 if (ssh->version == 2 && ssh->mainchan) {
11642 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11643 ssh2_pkt_addstring(pktout, signame);
11644 ssh2_pkt_send(ssh, pktout);
11645 logeventf(ssh, "Sent signal SIG%s", signame);
11648 /* Never heard of it. Do nothing */
11653 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11655 Ssh ssh = (Ssh) handle;
11656 struct ssh_channel *c;
11657 c = snew(struct ssh_channel);
11660 ssh_channel_init(c);
11661 c->halfopen = TRUE;
11662 c->type = CHAN_SOCKDATA;/* identify channel type */
11667 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11669 struct ssh_channel *c;
11670 c = snew(struct ssh_channel);
11673 ssh_channel_init(c);
11674 c->type = CHAN_SHARING;
11675 c->u.sharing.ctx = sharing_ctx;
11679 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11681 struct ssh_channel *c;
11683 c = find234(ssh->channels, &localid, ssh_channelfind);
11685 ssh_channel_destroy(c);
11688 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11689 const void *data, int datalen,
11690 const char *additional_log_text)
11692 struct Packet *pkt;
11694 pkt = ssh2_pkt_init(type);
11695 pkt->downstream_id = id;
11696 pkt->additional_log_text = additional_log_text;
11697 ssh2_pkt_adddata(pkt, data, datalen);
11698 ssh2_pkt_send(ssh, pkt);
11702 * This is called when stdout/stderr (the entity to which
11703 * from_backend sends data) manages to clear some backlog.
11705 static void ssh_unthrottle(void *handle, int bufsize)
11707 Ssh ssh = (Ssh) handle;
11709 if (ssh->version == 1) {
11710 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11711 ssh->v1_stdout_throttling = 0;
11712 ssh_throttle_conn(ssh, -1);
11716 ssh_channel_unthrottle(ssh->mainchan, bufsize);
11720 * Now process any SSH connection data that was stashed in our
11721 * queue while we were frozen.
11723 ssh_process_queued_incoming_data(ssh);
11726 void ssh_send_port_open(void *channel, const char *hostname, int port,
11729 struct ssh_channel *c = (struct ssh_channel *)channel;
11731 struct Packet *pktout;
11733 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11735 if (ssh->version == 1) {
11736 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11737 PKT_INT, c->localid,
11740 /* PKT_STR, <org:orgport>, */
11743 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11745 char *trimmed_host = host_strduptrim(hostname);
11746 ssh2_pkt_addstring(pktout, trimmed_host);
11747 sfree(trimmed_host);
11749 ssh2_pkt_adduint32(pktout, port);
11751 * We make up values for the originator data; partly it's
11752 * too much hassle to keep track, and partly I'm not
11753 * convinced the server should be told details like that
11754 * about my local network configuration.
11755 * The "originator IP address" is syntactically a numeric
11756 * IP address, and some servers (e.g., Tectia) get upset
11757 * if it doesn't match this syntax.
11759 ssh2_pkt_addstring(pktout, "0.0.0.0");
11760 ssh2_pkt_adduint32(pktout, 0);
11761 ssh2_pkt_send(ssh, pktout);
11765 static int ssh_connected(void *handle)
11767 Ssh ssh = (Ssh) handle;
11768 return ssh->s != NULL;
11771 static int ssh_sendok(void *handle)
11773 Ssh ssh = (Ssh) handle;
11774 return ssh->send_ok;
11777 static int ssh_ldisc(void *handle, int option)
11779 Ssh ssh = (Ssh) handle;
11780 if (option == LD_ECHO)
11781 return ssh->echoing;
11782 if (option == LD_EDIT)
11783 return ssh->editing;
11787 static void ssh_provide_ldisc(void *handle, void *ldisc)
11789 Ssh ssh = (Ssh) handle;
11790 ssh->ldisc = ldisc;
11793 static void ssh_provide_logctx(void *handle, void *logctx)
11795 Ssh ssh = (Ssh) handle;
11796 ssh->logctx = logctx;
11799 static int ssh_return_exitcode(void *handle)
11801 Ssh ssh = (Ssh) handle;
11802 if (ssh->s != NULL)
11805 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11809 * cfg_info for SSH is the protocol running in this session.
11810 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11811 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11813 static int ssh_cfg_info(void *handle)
11815 Ssh ssh = (Ssh) handle;
11816 if (ssh->version == 0)
11817 return 0; /* don't know yet */
11818 else if (ssh->bare_connection)
11821 return ssh->version;
11825 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11826 * that fails. This variable is the means by which scp.c can reach
11827 * into the SSH code and find out which one it got.
11829 extern int ssh_fallback_cmd(void *handle)
11831 Ssh ssh = (Ssh) handle;
11832 return ssh->fallback_cmd;
11835 Backend ssh_backend = {
11845 ssh_return_exitcode,
11849 ssh_provide_logctx,
11852 ssh_test_for_upstream,