29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
92 static const struct ssh_ttymode {
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "IUTF8", 42, TTY_OP_BOOL },
129 { "ISIG", 50, TTY_OP_BOOL },
130 { "ICANON", 51, TTY_OP_BOOL },
131 { "XCASE", 52, TTY_OP_BOOL },
132 { "ECHO", 53, TTY_OP_BOOL },
133 { "ECHOE", 54, TTY_OP_BOOL },
134 { "ECHOK", 55, TTY_OP_BOOL },
135 { "ECHONL", 56, TTY_OP_BOOL },
136 { "NOFLSH", 57, TTY_OP_BOOL },
137 { "TOSTOP", 58, TTY_OP_BOOL },
138 { "IEXTEN", 59, TTY_OP_BOOL },
139 { "ECHOCTL", 60, TTY_OP_BOOL },
140 { "ECHOKE", 61, TTY_OP_BOOL },
141 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
142 { "OPOST", 70, TTY_OP_BOOL },
143 { "OLCUC", 71, TTY_OP_BOOL },
144 { "ONLCR", 72, TTY_OP_BOOL },
145 { "OCRNL", 73, TTY_OP_BOOL },
146 { "ONOCR", 74, TTY_OP_BOOL },
147 { "ONLRET", 75, TTY_OP_BOOL },
148 { "CS7", 90, TTY_OP_BOOL },
149 { "CS8", 91, TTY_OP_BOOL },
150 { "PARENB", 92, TTY_OP_BOOL },
151 { "PARODD", 93, TTY_OP_BOOL }
154 /* Miscellaneous other tty-related constants. */
155 #define SSH_TTY_OP_END 0
156 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
157 #define SSH1_TTY_OP_ISPEED 192
158 #define SSH1_TTY_OP_OSPEED 193
159 #define SSH2_TTY_OP_ISPEED 128
160 #define SSH2_TTY_OP_OSPEED 129
162 /* Helper functions for parsing tty-related config. */
163 static unsigned int ssh_tty_parse_specchar(char *s)
168 ret = ctrlparse(s, &next);
169 if (!next) ret = s[0];
171 ret = 255; /* special value meaning "don't set" */
175 static unsigned int ssh_tty_parse_boolean(char *s)
177 if (stricmp(s, "yes") == 0 ||
178 stricmp(s, "on") == 0 ||
179 stricmp(s, "true") == 0 ||
180 stricmp(s, "+") == 0)
182 else if (stricmp(s, "no") == 0 ||
183 stricmp(s, "off") == 0 ||
184 stricmp(s, "false") == 0 ||
185 stricmp(s, "-") == 0)
186 return 0; /* false */
188 return (atoi(s) != 0);
191 #define translate(x) if (type == x) return #x
192 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
193 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
194 static const char *ssh1_pkt_type(int type)
196 translate(SSH1_MSG_DISCONNECT);
197 translate(SSH1_SMSG_PUBLIC_KEY);
198 translate(SSH1_CMSG_SESSION_KEY);
199 translate(SSH1_CMSG_USER);
200 translate(SSH1_CMSG_AUTH_RSA);
201 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
202 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
203 translate(SSH1_CMSG_AUTH_PASSWORD);
204 translate(SSH1_CMSG_REQUEST_PTY);
205 translate(SSH1_CMSG_WINDOW_SIZE);
206 translate(SSH1_CMSG_EXEC_SHELL);
207 translate(SSH1_CMSG_EXEC_CMD);
208 translate(SSH1_SMSG_SUCCESS);
209 translate(SSH1_SMSG_FAILURE);
210 translate(SSH1_CMSG_STDIN_DATA);
211 translate(SSH1_SMSG_STDOUT_DATA);
212 translate(SSH1_SMSG_STDERR_DATA);
213 translate(SSH1_CMSG_EOF);
214 translate(SSH1_SMSG_EXIT_STATUS);
215 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
216 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
217 translate(SSH1_MSG_CHANNEL_DATA);
218 translate(SSH1_MSG_CHANNEL_CLOSE);
219 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
220 translate(SSH1_SMSG_X11_OPEN);
221 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
222 translate(SSH1_MSG_PORT_OPEN);
223 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
224 translate(SSH1_SMSG_AGENT_OPEN);
225 translate(SSH1_MSG_IGNORE);
226 translate(SSH1_CMSG_EXIT_CONFIRMATION);
227 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
228 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
229 translate(SSH1_MSG_DEBUG);
230 translate(SSH1_CMSG_REQUEST_COMPRESSION);
231 translate(SSH1_CMSG_AUTH_TIS);
232 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
234 translate(SSH1_CMSG_AUTH_CCARD);
235 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
236 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
239 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
247 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
248 translate(SSH2_MSG_DISCONNECT);
249 translate(SSH2_MSG_IGNORE);
250 translate(SSH2_MSG_UNIMPLEMENTED);
251 translate(SSH2_MSG_DEBUG);
252 translate(SSH2_MSG_SERVICE_REQUEST);
253 translate(SSH2_MSG_SERVICE_ACCEPT);
254 translate(SSH2_MSG_KEXINIT);
255 translate(SSH2_MSG_NEWKEYS);
256 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
263 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
266 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
267 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
268 translate(SSH2_MSG_USERAUTH_REQUEST);
269 translate(SSH2_MSG_USERAUTH_FAILURE);
270 translate(SSH2_MSG_USERAUTH_SUCCESS);
271 translate(SSH2_MSG_USERAUTH_BANNER);
272 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
273 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
274 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
275 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
276 translate(SSH2_MSG_GLOBAL_REQUEST);
277 translate(SSH2_MSG_REQUEST_SUCCESS);
278 translate(SSH2_MSG_REQUEST_FAILURE);
279 translate(SSH2_MSG_CHANNEL_OPEN);
280 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
281 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
282 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
283 translate(SSH2_MSG_CHANNEL_DATA);
284 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
285 translate(SSH2_MSG_CHANNEL_EOF);
286 translate(SSH2_MSG_CHANNEL_CLOSE);
287 translate(SSH2_MSG_CHANNEL_REQUEST);
288 translate(SSH2_MSG_CHANNEL_SUCCESS);
289 translate(SSH2_MSG_CHANNEL_FAILURE);
295 /* Enumeration values for fields in SSH-1 packets */
297 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
301 * Coroutine mechanics for the sillier bits of the code. If these
302 * macros look impenetrable to you, you might find it helpful to
305 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
307 * which explains the theory behind these macros.
309 * In particular, if you are getting `case expression not constant'
310 * errors when building with MS Visual Studio, this is because MS's
311 * Edit and Continue debugging feature causes their compiler to
312 * violate ANSI C. To disable Edit and Continue debugging:
314 * - right-click ssh.c in the FileView
316 * - select the C/C++ tab and the General category
317 * - under `Debug info:', select anything _other_ than `Program
318 * Database for Edit and Continue'.
320 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
321 #define crBeginState crBegin(s->crLine)
322 #define crStateP(t, v) \
324 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
326 #define crState(t) crStateP(t, ssh->t)
327 #define crFinish(z) } *crLine = 0; return (z); }
328 #define crFinishV } *crLine = 0; return; }
329 #define crFinishFree(z) } sfree(s); return (z); }
330 #define crFinishFreeV } sfree(s); return; }
331 #define crReturn(z) \
333 *crLine =__LINE__; return (z); case __LINE__:;\
337 *crLine=__LINE__; return; case __LINE__:;\
339 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
340 #define crStopV do{ *crLine = 0; return; }while(0)
341 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
342 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
346 static struct Packet *ssh1_pkt_init(int pkt_type);
347 static struct Packet *ssh2_pkt_init(int pkt_type);
348 static void ssh_pkt_ensure(struct Packet *, int length);
349 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
350 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
351 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
352 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
353 static void ssh_pkt_addstring_start(struct Packet *);
354 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
355 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
356 static void ssh_pkt_addstring(struct Packet *, const char *data);
357 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
358 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
359 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
360 static int ssh2_pkt_construct(Ssh, struct Packet *);
361 static void ssh2_pkt_send(Ssh, struct Packet *);
362 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
363 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
364 struct Packet *pktin);
365 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
366 struct Packet *pktin);
367 static void ssh_channel_init(struct ssh_channel *c);
368 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin);
369 static void ssh2_channel_check_close(struct ssh_channel *c);
370 static void ssh_channel_destroy(struct ssh_channel *c);
371 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize);
372 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
375 * Buffer management constants. There are several of these for
376 * various different purposes:
378 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
379 * on a local data stream before we throttle the whole SSH
380 * connection (in SSH-1 only). Throttling the whole connection is
381 * pretty drastic so we set this high in the hope it won't
384 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
385 * on the SSH connection itself before we defensively throttle
386 * _all_ local data streams. This is pretty drastic too (though
387 * thankfully unlikely in SSH-2 since the window mechanism should
388 * ensure that the server never has any need to throttle its end
389 * of the connection), so we set this high as well.
391 * - OUR_V2_WINSIZE is the default window size we present on SSH-2
394 * - OUR_V2_BIGWIN is the window size we advertise for the only
395 * channel in a simple connection. It must be <= INT_MAX.
397 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
398 * to the remote side. This actually has nothing to do with the
399 * size of the _packet_, but is instead a limit on the amount
400 * of data we're willing to receive in a single SSH2 channel
403 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
404 * _packet_ we're prepared to cope with. It must be a multiple
405 * of the cipher block size, and must be at least 35000.
408 #define SSH1_BUFFER_LIMIT 32768
409 #define SSH_MAX_BACKLOG 32768
410 #define OUR_V2_WINSIZE 16384
411 #define OUR_V2_BIGWIN 0x7fffffff
412 #define OUR_V2_MAXPKT 0x4000UL
413 #define OUR_V2_PACKETLIMIT 0x9000UL
415 struct ssh_signkey_with_user_pref_id {
416 const struct ssh_signkey *alg;
419 const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = {
420 { &ssh_ecdsa_ed25519, HK_ED25519 },
421 { &ssh_ecdsa_nistp256, HK_ECDSA },
422 { &ssh_ecdsa_nistp384, HK_ECDSA },
423 { &ssh_ecdsa_nistp521, HK_ECDSA },
424 { &ssh_dss, HK_DSA },
425 { &ssh_rsa, HK_RSA },
428 const static struct ssh_mac *const macs[] = {
429 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
431 const static struct ssh_mac *const buggymacs[] = {
432 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
435 static void *ssh_comp_none_init(void)
439 static void ssh_comp_none_cleanup(void *handle)
442 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
443 unsigned char **outblock, int *outlen)
447 static int ssh_comp_none_disable(void *handle)
451 const static struct ssh_compress ssh_comp_none = {
453 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
454 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
455 ssh_comp_none_disable, NULL
457 extern const struct ssh_compress ssh_zlib;
458 const static struct ssh_compress *const compressions[] = {
459 &ssh_zlib, &ssh_comp_none
462 enum { /* channel types */
467 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
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 case CHAN_SOCKDATA_DORMANT:
3473 pfd_close(c->u.pfd.pf);
3476 del234(ssh->channels, c); /* moving next one to index 0 */
3477 if (ssh->version == 2)
3478 bufchain_clear(&c->v.v2.outbuffer);
3483 * Go through port-forwardings, and close any associated
3484 * listening sockets.
3486 if (ssh->portfwds) {
3487 struct ssh_portfwd *pf;
3488 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3489 /* Dispose of any listening socket. */
3491 pfl_terminate(pf->local);
3492 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3495 freetree234(ssh->portfwds);
3496 ssh->portfwds = NULL;
3500 * Also stop attempting to connection-share.
3502 if (ssh->connshare) {
3503 sharestate_free(ssh->connshare);
3504 ssh->connshare = NULL;
3510 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3511 const char *error_msg, int error_code)
3513 Ssh ssh = (Ssh) plug;
3516 * While we're attempting connection sharing, don't loudly log
3517 * everything that happens. Real TCP connections need to be logged
3518 * when we _start_ trying to connect, because it might be ages
3519 * before they respond if something goes wrong; but connection
3520 * sharing is local and quick to respond, and it's sufficient to
3521 * simply wait and see whether it worked afterwards.
3524 if (!ssh->attempting_connshare)
3525 backend_socket_log(ssh->frontend, type, addr, port,
3526 error_msg, error_code, ssh->conf,
3527 ssh->session_started);
3530 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3531 const char *ds_err, const char *us_err)
3533 if (event == SHARE_NONE) {
3534 /* In this case, 'logtext' is an error message indicating a
3535 * reason why connection sharing couldn't be set up _at all_.
3536 * Failing that, ds_err and us_err indicate why we couldn't be
3537 * a downstream and an upstream respectively. */
3539 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3542 logeventf(ssh, "Could not set up connection sharing"
3543 " as downstream: %s", ds_err);
3545 logeventf(ssh, "Could not set up connection sharing"
3546 " as upstream: %s", us_err);
3548 } else if (event == SHARE_DOWNSTREAM) {
3549 /* In this case, 'logtext' is a local endpoint address */
3550 logeventf(ssh, "Using existing shared connection at %s", logtext);
3551 /* Also we should mention this in the console window to avoid
3552 * confusing users as to why this window doesn't behave the
3554 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3555 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3557 } else if (event == SHARE_UPSTREAM) {
3558 /* In this case, 'logtext' is a local endpoint address too */
3559 logeventf(ssh, "Sharing this connection at %s", logtext);
3563 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3566 Ssh ssh = (Ssh) plug;
3567 int need_notify = ssh_do_close(ssh, FALSE);
3570 if (!ssh->close_expected)
3571 error_msg = "Server unexpectedly closed network connection";
3573 error_msg = "Server closed network connection";
3576 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3580 notify_remote_exit(ssh->frontend);
3583 logevent(error_msg);
3584 if (!ssh->close_expected || !ssh->clean_exit)
3585 connection_fatal(ssh->frontend, "%s", error_msg);
3589 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3591 Ssh ssh = (Ssh) plug;
3592 ssh_gotdata(ssh, (unsigned char *)data, len);
3593 if (ssh->state == SSH_STATE_CLOSED) {
3594 ssh_do_close(ssh, TRUE);
3600 static void ssh_sent(Plug plug, int bufsize)
3602 Ssh ssh = (Ssh) plug;
3604 * If the send backlog on the SSH socket itself clears, we
3605 * should unthrottle the whole world if it was throttled.
3607 if (bufsize < SSH_MAX_BACKLOG)
3608 ssh_throttle_all(ssh, 0, bufsize);
3611 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3612 char **savedhost, int *savedport,
3615 char *loghost = conf_get_str(conf, CONF_loghost);
3617 *loghost_ret = loghost;
3623 tmphost = dupstr(loghost);
3624 *savedport = 22; /* default ssh port */
3627 * A colon suffix on the hostname string also lets us affect
3628 * savedport. (Unless there are multiple colons, in which case
3629 * we assume this is an unbracketed IPv6 literal.)
3631 colon = host_strrchr(tmphost, ':');
3632 if (colon && colon == host_strchr(tmphost, ':')) {
3635 *savedport = atoi(colon);
3638 *savedhost = host_strduptrim(tmphost);
3641 *savedhost = host_strduptrim(host);
3643 port = 22; /* default ssh port */
3648 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3654 random_ref(); /* platform may need this to determine share socket name */
3655 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3656 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3664 * Connect to specified host and port.
3665 * Returns an error message, or NULL on success.
3666 * Also places the canonical host name into `realhost'. It must be
3667 * freed by the caller.
3669 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3670 char **realhost, int nodelay, int keepalive)
3672 static const struct plug_function_table fn_table = {
3683 int addressfamily, sshprot;
3685 ssh_hostport_setup(host, port, ssh->conf,
3686 &ssh->savedhost, &ssh->savedport, &loghost);
3688 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3691 * Try connection-sharing, in case that means we don't open a
3692 * socket after all. ssh_connection_sharing_init will connect to a
3693 * previously established upstream if it can, and failing that,
3694 * establish a listening socket for _us_ to be the upstream. In
3695 * the latter case it will return NULL just as if it had done
3696 * nothing, because here we only need to care if we're a
3697 * downstream and need to do our connection setup differently.
3699 ssh->connshare = NULL;
3700 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3701 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3702 ssh->conf, ssh, &ssh->connshare);
3703 ssh->attempting_connshare = FALSE;
3704 if (ssh->s != NULL) {
3706 * We are a downstream.
3708 ssh->bare_connection = TRUE;
3709 ssh->do_ssh_init = do_ssh_connection_init;
3710 ssh->fullhostname = NULL;
3711 *realhost = dupstr(host); /* best we can do */
3714 * We're not a downstream, so open a normal socket.
3716 ssh->do_ssh_init = do_ssh_init;
3721 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3722 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3723 ssh->frontend, "SSH connection");
3724 if ((err = sk_addr_error(addr)) != NULL) {
3728 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3730 ssh->s = new_connection(addr, *realhost, port,
3731 0, 1, nodelay, keepalive,
3732 (Plug) ssh, ssh->conf);
3733 if ((err = sk_socket_error(ssh->s)) != NULL) {
3735 notify_remote_exit(ssh->frontend);
3741 * The SSH version number is always fixed (since we no longer support
3742 * fallback between versions), so set it now, and if it's SSH-2,
3743 * send the version string now too.
3745 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3746 assert(sshprot == 0 || sshprot == 3);
3750 if (sshprot == 3 && !ssh->bare_connection) {
3753 ssh_send_verstring(ssh, "SSH-", NULL);
3757 * loghost, if configured, overrides realhost.
3761 *realhost = dupstr(loghost);
3768 * Throttle or unthrottle the SSH connection.
3770 static void ssh_throttle_conn(Ssh ssh, int adjust)
3772 int old_count = ssh->conn_throttle_count;
3773 ssh->conn_throttle_count += adjust;
3774 assert(ssh->conn_throttle_count >= 0);
3775 if (ssh->conn_throttle_count && !old_count) {
3776 ssh_set_frozen(ssh, 1);
3777 } else if (!ssh->conn_throttle_count && old_count) {
3778 ssh_set_frozen(ssh, 0);
3783 * Throttle or unthrottle _all_ local data streams (for when sends
3784 * on the SSH connection itself back up).
3786 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3789 struct ssh_channel *c;
3791 if (enable == ssh->throttled_all)
3793 ssh->throttled_all = enable;
3794 ssh->overall_bufsize = bufsize;
3797 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3799 case CHAN_MAINSESSION:
3801 * This is treated separately, outside the switch.
3805 x11_override_throttle(c->u.x11.xconn, enable);
3808 /* Agent channels require no buffer management. */
3811 pfd_override_throttle(c->u.pfd.pf, enable);
3817 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3819 Ssh ssh = (Ssh) sshv;
3821 ssh->agent_response = reply;
3822 ssh->agent_response_len = replylen;
3824 if (ssh->version == 1)
3825 do_ssh1_login(ssh, NULL, -1, NULL);
3827 do_ssh2_authconn(ssh, NULL, -1, NULL);
3830 static void ssh_dialog_callback(void *sshv, int ret)
3832 Ssh ssh = (Ssh) sshv;
3834 ssh->user_response = ret;
3836 if (ssh->version == 1)
3837 do_ssh1_login(ssh, NULL, -1, NULL);
3839 do_ssh2_transport(ssh, NULL, -1, NULL);
3842 * This may have unfrozen the SSH connection, so do a
3845 ssh_process_queued_incoming_data(ssh);
3848 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3850 struct ssh_channel *c = (struct ssh_channel *)cv;
3851 const void *sentreply = reply;
3853 c->u.a.outstanding_requests--;
3855 /* Fake SSH_AGENT_FAILURE. */
3856 sentreply = "\0\0\0\1\5";
3859 ssh_send_channel_data(c, sentreply, replylen);
3863 * If we've already seen an incoming EOF but haven't sent an
3864 * outgoing one, this may be the moment to send it.
3866 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3867 sshfwd_write_eof(c);
3871 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3872 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3873 * => log `wire_reason'.
3875 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3876 const char *wire_reason,
3877 int code, int clean_exit)
3881 client_reason = wire_reason;
3883 error = dupprintf("Disconnected: %s", client_reason);
3885 error = dupstr("Disconnected");
3887 if (ssh->version == 1) {
3888 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3890 } else if (ssh->version == 2) {
3891 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3892 ssh2_pkt_adduint32(pktout, code);
3893 ssh2_pkt_addstring(pktout, wire_reason);
3894 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3895 ssh2_pkt_send_noqueue(ssh, pktout);
3898 ssh->close_expected = TRUE;
3899 ssh->clean_exit = clean_exit;
3900 ssh_closing((Plug)ssh, error, 0, 0);
3904 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3905 const struct ssh_signkey *ssh2keytype,
3908 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3909 return -1; /* no manual keys configured */
3914 * The fingerprint string we've been given will have things
3915 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3916 * narrow down to just the colon-separated hex block at the
3917 * end of the string.
3919 const char *p = strrchr(fingerprint, ' ');
3920 fingerprint = p ? p+1 : fingerprint;
3921 /* Quick sanity checks, including making sure it's in lowercase */
3922 assert(strlen(fingerprint) == 16*3 - 1);
3923 assert(fingerprint[2] == ':');
3924 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3926 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3928 return 1; /* success */
3933 * Construct the base64-encoded public key blob and see if
3936 unsigned char *binblob;
3938 int binlen, atoms, i;
3939 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3940 atoms = (binlen + 2) / 3;
3941 base64blob = snewn(atoms * 4 + 1, char);
3942 for (i = 0; i < atoms; i++)
3943 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3944 base64blob[atoms * 4] = '\0';
3946 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3949 return 1; /* success */
3958 * Handle the key exchange and user authentication phases.
3960 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3961 struct Packet *pktin)
3964 unsigned char cookie[8], *ptr;
3965 struct MD5Context md5c;
3966 struct do_ssh1_login_state {
3969 unsigned char *rsabuf;
3970 const unsigned char *keystr1, *keystr2;
3971 unsigned long supported_ciphers_mask, supported_auths_mask;
3972 int tried_publickey, tried_agent;
3973 int tis_auth_refused, ccard_auth_refused;
3974 unsigned char session_id[16];
3976 void *publickey_blob;
3977 int publickey_bloblen;
3978 char *publickey_comment;
3979 int privatekey_available, privatekey_encrypted;
3980 prompts_t *cur_prompt;
3983 unsigned char request[5], *response, *p;
3993 struct RSAKey servkey, hostkey;
3995 crState(do_ssh1_login_state);
4002 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
4003 bombout(("Public key packet not received"));
4007 logevent("Received public keys");
4009 ptr = ssh_pkt_getdata(pktin, 8);
4011 bombout(("SSH-1 public key packet stopped before random cookie"));
4014 memcpy(cookie, ptr, 8);
4016 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
4017 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
4018 bombout(("Failed to read SSH-1 public keys from public key packet"));
4023 * Log the host key fingerprint.
4027 logevent("Host key fingerprint is:");
4028 strcpy(logmsg, " ");
4029 s->hostkey.comment = NULL;
4030 rsa_fingerprint(logmsg + strlen(logmsg),
4031 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4035 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4036 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4037 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4038 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4039 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4041 ssh->v1_local_protoflags =
4042 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4043 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4046 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4047 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4048 MD5Update(&md5c, cookie, 8);
4049 MD5Final(s->session_id, &md5c);
4051 for (i = 0; i < 32; i++)
4052 ssh->session_key[i] = random_byte();
4055 * Verify that the `bits' and `bytes' parameters match.
4057 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4058 s->servkey.bits > s->servkey.bytes * 8) {
4059 bombout(("SSH-1 public keys were badly formatted"));
4063 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4064 s->hostkey.bytes : s->servkey.bytes);
4066 s->rsabuf = snewn(s->len, unsigned char);
4069 * Verify the host key.
4073 * First format the key into a string.
4075 int len = rsastr_len(&s->hostkey);
4076 char fingerprint[100];
4077 char *keystr = snewn(len, char);
4078 rsastr_fmt(keystr, &s->hostkey);
4079 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4081 /* First check against manually configured host keys. */
4082 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4083 if (s->dlgret == 0) { /* did not match */
4084 bombout(("Host key did not appear in manually configured list"));
4087 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4088 ssh_set_frozen(ssh, 1);
4089 s->dlgret = verify_ssh_host_key(ssh->frontend,
4090 ssh->savedhost, ssh->savedport,
4091 "rsa", keystr, fingerprint,
4092 ssh_dialog_callback, ssh);
4097 if (s->dlgret < 0) {
4101 bombout(("Unexpected data from server while waiting"
4102 " for user host key response"));
4105 } while (pktin || inlen > 0);
4106 s->dlgret = ssh->user_response;
4108 ssh_set_frozen(ssh, 0);
4110 if (s->dlgret == 0) {
4111 ssh_disconnect(ssh, "User aborted at host key verification",
4120 for (i = 0; i < 32; i++) {
4121 s->rsabuf[i] = ssh->session_key[i];
4123 s->rsabuf[i] ^= s->session_id[i];
4126 if (s->hostkey.bytes > s->servkey.bytes) {
4127 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4129 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4131 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4133 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4136 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4140 logevent("Encrypted session key");
4143 int cipher_chosen = 0, warn = 0;
4144 const char *cipher_string = NULL;
4146 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4147 int next_cipher = conf_get_int_int(ssh->conf,
4148 CONF_ssh_cipherlist, i);
4149 if (next_cipher == CIPHER_WARN) {
4150 /* If/when we choose a cipher, warn about it */
4152 } else if (next_cipher == CIPHER_AES) {
4153 /* XXX Probably don't need to mention this. */
4154 logevent("AES not supported in SSH-1, skipping");
4156 switch (next_cipher) {
4157 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4158 cipher_string = "3DES"; break;
4159 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4160 cipher_string = "Blowfish"; break;
4161 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4162 cipher_string = "single-DES"; break;
4164 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4168 if (!cipher_chosen) {
4169 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4170 bombout(("Server violates SSH-1 protocol by not "
4171 "supporting 3DES encryption"));
4173 /* shouldn't happen */
4174 bombout(("No supported ciphers found"));
4178 /* Warn about chosen cipher if necessary. */
4180 ssh_set_frozen(ssh, 1);
4181 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4182 ssh_dialog_callback, ssh);
4183 if (s->dlgret < 0) {
4187 bombout(("Unexpected data from server while waiting"
4188 " for user response"));
4191 } while (pktin || inlen > 0);
4192 s->dlgret = ssh->user_response;
4194 ssh_set_frozen(ssh, 0);
4195 if (s->dlgret == 0) {
4196 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4203 switch (s->cipher_type) {
4204 case SSH_CIPHER_3DES:
4205 logevent("Using 3DES encryption");
4207 case SSH_CIPHER_DES:
4208 logevent("Using single-DES encryption");
4210 case SSH_CIPHER_BLOWFISH:
4211 logevent("Using Blowfish encryption");
4215 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4216 PKT_CHAR, s->cipher_type,
4217 PKT_DATA, cookie, 8,
4218 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4219 PKT_DATA, s->rsabuf, s->len,
4220 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4222 logevent("Trying to enable encryption...");
4226 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4227 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4229 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4230 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4231 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4233 ssh->crcda_ctx = crcda_make_context();
4234 logevent("Installing CRC compensation attack detector");
4236 if (s->servkey.modulus) {
4237 sfree(s->servkey.modulus);
4238 s->servkey.modulus = NULL;
4240 if (s->servkey.exponent) {
4241 sfree(s->servkey.exponent);
4242 s->servkey.exponent = NULL;
4244 if (s->hostkey.modulus) {
4245 sfree(s->hostkey.modulus);
4246 s->hostkey.modulus = NULL;
4248 if (s->hostkey.exponent) {
4249 sfree(s->hostkey.exponent);
4250 s->hostkey.exponent = NULL;
4254 if (pktin->type != SSH1_SMSG_SUCCESS) {
4255 bombout(("Encryption not successfully enabled"));
4259 logevent("Successfully started encryption");
4261 fflush(stdout); /* FIXME eh? */
4263 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4264 int ret; /* need not be kept over crReturn */
4265 s->cur_prompt = new_prompts(ssh->frontend);
4266 s->cur_prompt->to_server = TRUE;
4267 s->cur_prompt->name = dupstr("SSH login name");
4268 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4269 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4272 crWaitUntil(!pktin);
4273 ret = get_userpass_input(s->cur_prompt, in, inlen);
4278 * Failed to get a username. Terminate.
4280 free_prompts(s->cur_prompt);
4281 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4284 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4285 free_prompts(s->cur_prompt);
4288 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4290 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4292 if (flags & FLAG_INTERACTIVE &&
4293 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4294 c_write_str(ssh, userlog);
4295 c_write_str(ssh, "\r\n");
4303 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4304 /* We must not attempt PK auth. Pretend we've already tried it. */
4305 s->tried_publickey = s->tried_agent = 1;
4307 s->tried_publickey = s->tried_agent = 0;
4309 s->tis_auth_refused = s->ccard_auth_refused = 0;
4311 * Load the public half of any configured keyfile for later use.
4313 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4314 if (!filename_is_null(s->keyfile)) {
4316 logeventf(ssh, "Reading key file \"%.150s\"",
4317 filename_to_str(s->keyfile));
4318 keytype = key_type(s->keyfile);
4319 if (keytype == SSH_KEYTYPE_SSH1 ||
4320 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4322 if (rsakey_pubblob(s->keyfile,
4323 &s->publickey_blob, &s->publickey_bloblen,
4324 &s->publickey_comment, &error)) {
4325 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4326 if (!s->privatekey_available)
4327 logeventf(ssh, "Key file contains public key only");
4328 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4332 logeventf(ssh, "Unable to load key (%s)", error);
4333 msgbuf = dupprintf("Unable to load key file "
4334 "\"%.150s\" (%s)\r\n",
4335 filename_to_str(s->keyfile),
4337 c_write_str(ssh, msgbuf);
4339 s->publickey_blob = NULL;
4343 logeventf(ssh, "Unable to use this key file (%s)",
4344 key_type_to_str(keytype));
4345 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4347 filename_to_str(s->keyfile),
4348 key_type_to_str(keytype));
4349 c_write_str(ssh, msgbuf);
4351 s->publickey_blob = NULL;
4354 s->publickey_blob = NULL;
4356 while (pktin->type == SSH1_SMSG_FAILURE) {
4357 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4359 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4361 * Attempt RSA authentication using Pageant.
4367 logevent("Pageant is running. Requesting keys.");
4369 /* Request the keys held by the agent. */
4370 PUT_32BIT(s->request, 1);
4371 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4372 if (!agent_query(s->request, 5, &r, &s->responselen,
4373 ssh_agent_callback, ssh)) {
4377 bombout(("Unexpected data from server while waiting"
4378 " for agent response"));
4381 } while (pktin || inlen > 0);
4382 r = ssh->agent_response;
4383 s->responselen = ssh->agent_response_len;
4385 s->response = (unsigned char *) r;
4386 if (s->response && s->responselen >= 5 &&
4387 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4388 s->p = s->response + 5;
4389 s->nkeys = toint(GET_32BIT(s->p));
4391 logeventf(ssh, "Pageant reported negative key count %d",
4396 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4397 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4398 unsigned char *pkblob = s->p;
4402 do { /* do while (0) to make breaking easy */
4403 n = ssh1_read_bignum
4404 (s->p, toint(s->responselen-(s->p-s->response)),
4409 n = ssh1_read_bignum
4410 (s->p, toint(s->responselen-(s->p-s->response)),
4415 if (s->responselen - (s->p-s->response) < 4)
4417 s->commentlen = toint(GET_32BIT(s->p));
4419 if (s->commentlen < 0 ||
4420 toint(s->responselen - (s->p-s->response)) <
4423 s->commentp = (char *)s->p;
4424 s->p += s->commentlen;
4428 logevent("Pageant key list packet was truncated");
4432 if (s->publickey_blob) {
4433 if (!memcmp(pkblob, s->publickey_blob,
4434 s->publickey_bloblen)) {
4435 logeventf(ssh, "Pageant key #%d matches "
4436 "configured key file", s->keyi);
4437 s->tried_publickey = 1;
4439 /* Skip non-configured key */
4442 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4443 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4444 PKT_BIGNUM, s->key.modulus, PKT_END);
4446 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4447 logevent("Key refused");
4450 logevent("Received RSA challenge");
4451 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4452 bombout(("Server's RSA challenge was badly formatted"));
4457 char *agentreq, *q, *ret;
4460 len = 1 + 4; /* message type, bit count */
4461 len += ssh1_bignum_length(s->key.exponent);
4462 len += ssh1_bignum_length(s->key.modulus);
4463 len += ssh1_bignum_length(s->challenge);
4464 len += 16; /* session id */
4465 len += 4; /* response format */
4466 agentreq = snewn(4 + len, char);
4467 PUT_32BIT(agentreq, len);
4469 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4470 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4472 q += ssh1_write_bignum(q, s->key.exponent);
4473 q += ssh1_write_bignum(q, s->key.modulus);
4474 q += ssh1_write_bignum(q, s->challenge);
4475 memcpy(q, s->session_id, 16);
4477 PUT_32BIT(q, 1); /* response format */
4478 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4479 ssh_agent_callback, ssh)) {
4484 bombout(("Unexpected data from server"
4485 " while waiting for agent"
4489 } while (pktin || inlen > 0);
4490 vret = ssh->agent_response;
4491 retlen = ssh->agent_response_len;
4496 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4497 logevent("Sending Pageant's response");
4498 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4499 PKT_DATA, ret + 5, 16,
4503 if (pktin->type == SSH1_SMSG_SUCCESS) {
4505 ("Pageant's response accepted");
4506 if (flags & FLAG_VERBOSE) {
4507 c_write_str(ssh, "Authenticated using"
4509 c_write(ssh, s->commentp,
4511 c_write_str(ssh, "\" from agent\r\n");
4516 ("Pageant's response not accepted");
4519 ("Pageant failed to answer challenge");
4523 logevent("No reply received from Pageant");
4526 freebn(s->key.exponent);
4527 freebn(s->key.modulus);
4528 freebn(s->challenge);
4533 if (s->publickey_blob && !s->tried_publickey)
4534 logevent("Configured key file not in Pageant");
4536 logevent("Failed to get reply from Pageant");
4541 if (s->publickey_blob && s->privatekey_available &&
4542 !s->tried_publickey) {
4544 * Try public key authentication with the specified
4547 int got_passphrase; /* need not be kept over crReturn */
4548 if (flags & FLAG_VERBOSE)
4549 c_write_str(ssh, "Trying public key authentication.\r\n");
4550 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4551 logeventf(ssh, "Trying public key \"%s\"",
4552 filename_to_str(s->keyfile));
4553 s->tried_publickey = 1;
4554 got_passphrase = FALSE;
4555 while (!got_passphrase) {
4557 * Get a passphrase, if necessary.
4559 char *passphrase = NULL; /* only written after crReturn */
4561 if (!s->privatekey_encrypted) {
4562 if (flags & FLAG_VERBOSE)
4563 c_write_str(ssh, "No passphrase required.\r\n");
4566 int ret; /* need not be kept over crReturn */
4567 s->cur_prompt = new_prompts(ssh->frontend);
4568 s->cur_prompt->to_server = FALSE;
4569 s->cur_prompt->name = dupstr("SSH key passphrase");
4570 add_prompt(s->cur_prompt,
4571 dupprintf("Passphrase for key \"%.100s\": ",
4572 s->publickey_comment), FALSE);
4573 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4576 crWaitUntil(!pktin);
4577 ret = get_userpass_input(s->cur_prompt, in, inlen);
4581 /* Failed to get a passphrase. Terminate. */
4582 free_prompts(s->cur_prompt);
4583 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4587 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4588 free_prompts(s->cur_prompt);
4591 * Try decrypting key with passphrase.
4593 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4594 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4597 smemclr(passphrase, strlen(passphrase));
4601 /* Correct passphrase. */
4602 got_passphrase = TRUE;
4603 } else if (ret == 0) {
4604 c_write_str(ssh, "Couldn't load private key from ");
4605 c_write_str(ssh, filename_to_str(s->keyfile));
4606 c_write_str(ssh, " (");
4607 c_write_str(ssh, error);
4608 c_write_str(ssh, ").\r\n");
4609 got_passphrase = FALSE;
4610 break; /* go and try something else */
4611 } else if (ret == -1) {
4612 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4613 got_passphrase = FALSE;
4616 assert(0 && "unexpected return from loadrsakey()");
4617 got_passphrase = FALSE; /* placate optimisers */
4621 if (got_passphrase) {
4624 * Send a public key attempt.
4626 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4627 PKT_BIGNUM, s->key.modulus, PKT_END);
4630 if (pktin->type == SSH1_SMSG_FAILURE) {
4631 c_write_str(ssh, "Server refused our public key.\r\n");
4632 continue; /* go and try something else */
4634 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4635 bombout(("Bizarre response to offer of public key"));
4641 unsigned char buffer[32];
4642 Bignum challenge, response;
4644 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4645 bombout(("Server's RSA challenge was badly formatted"));
4648 response = rsadecrypt(challenge, &s->key);
4649 freebn(s->key.private_exponent);/* burn the evidence */
4651 for (i = 0; i < 32; i++) {
4652 buffer[i] = bignum_byte(response, 31 - i);
4656 MD5Update(&md5c, buffer, 32);
4657 MD5Update(&md5c, s->session_id, 16);
4658 MD5Final(buffer, &md5c);
4660 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4661 PKT_DATA, buffer, 16, PKT_END);
4668 if (pktin->type == SSH1_SMSG_FAILURE) {
4669 if (flags & FLAG_VERBOSE)
4670 c_write_str(ssh, "Failed to authenticate with"
4671 " our public key.\r\n");
4672 continue; /* go and try something else */
4673 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4674 bombout(("Bizarre response to RSA authentication response"));
4678 break; /* we're through! */
4684 * Otherwise, try various forms of password-like authentication.
4686 s->cur_prompt = new_prompts(ssh->frontend);
4688 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4689 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4690 !s->tis_auth_refused) {
4691 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4692 logevent("Requested TIS authentication");
4693 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4695 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4696 logevent("TIS authentication declined");
4697 if (flags & FLAG_INTERACTIVE)
4698 c_write_str(ssh, "TIS authentication refused.\r\n");
4699 s->tis_auth_refused = 1;
4704 char *instr_suf, *prompt;
4706 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4708 bombout(("TIS challenge packet was badly formed"));
4711 logevent("Received TIS challenge");
4712 s->cur_prompt->to_server = TRUE;
4713 s->cur_prompt->name = dupstr("SSH TIS authentication");
4714 /* Prompt heuristic comes from OpenSSH */
4715 if (memchr(challenge, '\n', challengelen)) {
4716 instr_suf = dupstr("");
4717 prompt = dupprintf("%.*s", challengelen, challenge);
4719 instr_suf = dupprintf("%.*s", challengelen, challenge);
4720 prompt = dupstr("Response: ");
4722 s->cur_prompt->instruction =
4723 dupprintf("Using TIS authentication.%s%s",
4724 (*instr_suf) ? "\n" : "",
4726 s->cur_prompt->instr_reqd = TRUE;
4727 add_prompt(s->cur_prompt, prompt, FALSE);
4731 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4732 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4733 !s->ccard_auth_refused) {
4734 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4735 logevent("Requested CryptoCard authentication");
4736 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4738 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4739 logevent("CryptoCard authentication declined");
4740 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4741 s->ccard_auth_refused = 1;
4746 char *instr_suf, *prompt;
4748 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4750 bombout(("CryptoCard challenge packet was badly formed"));
4753 logevent("Received CryptoCard challenge");
4754 s->cur_prompt->to_server = TRUE;
4755 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4756 s->cur_prompt->name_reqd = FALSE;
4757 /* Prompt heuristic comes from OpenSSH */
4758 if (memchr(challenge, '\n', challengelen)) {
4759 instr_suf = dupstr("");
4760 prompt = dupprintf("%.*s", challengelen, challenge);
4762 instr_suf = dupprintf("%.*s", challengelen, challenge);
4763 prompt = dupstr("Response: ");
4765 s->cur_prompt->instruction =
4766 dupprintf("Using CryptoCard authentication.%s%s",
4767 (*instr_suf) ? "\n" : "",
4769 s->cur_prompt->instr_reqd = TRUE;
4770 add_prompt(s->cur_prompt, prompt, FALSE);
4774 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4775 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4776 bombout(("No supported authentication methods available"));
4779 s->cur_prompt->to_server = TRUE;
4780 s->cur_prompt->name = dupstr("SSH password");
4781 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4782 ssh->username, ssh->savedhost),
4787 * Show password prompt, having first obtained it via a TIS
4788 * or CryptoCard exchange if we're doing TIS or CryptoCard
4792 int ret; /* need not be kept over crReturn */
4793 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4796 crWaitUntil(!pktin);
4797 ret = get_userpass_input(s->cur_prompt, in, inlen);
4802 * Failed to get a password (for example
4803 * because one was supplied on the command line
4804 * which has already failed to work). Terminate.
4806 free_prompts(s->cur_prompt);
4807 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4812 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4814 * Defence against traffic analysis: we send a
4815 * whole bunch of packets containing strings of
4816 * different lengths. One of these strings is the
4817 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4818 * The others are all random data in
4819 * SSH1_MSG_IGNORE packets. This way a passive
4820 * listener can't tell which is the password, and
4821 * hence can't deduce the password length.
4823 * Anybody with a password length greater than 16
4824 * bytes is going to have enough entropy in their
4825 * password that a listener won't find it _that_
4826 * much help to know how long it is. So what we'll
4829 * - if password length < 16, we send 15 packets
4830 * containing string lengths 1 through 15
4832 * - otherwise, we let N be the nearest multiple
4833 * of 8 below the password length, and send 8
4834 * packets containing string lengths N through
4835 * N+7. This won't obscure the order of
4836 * magnitude of the password length, but it will
4837 * introduce a bit of extra uncertainty.
4839 * A few servers can't deal with SSH1_MSG_IGNORE, at
4840 * least in this context. For these servers, we need
4841 * an alternative defence. We make use of the fact
4842 * that the password is interpreted as a C string:
4843 * so we can append a NUL, then some random data.
4845 * A few servers can deal with neither SSH1_MSG_IGNORE
4846 * here _nor_ a padded password string.
4847 * For these servers we are left with no defences
4848 * against password length sniffing.
4850 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4851 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4853 * The server can deal with SSH1_MSG_IGNORE, so
4854 * we can use the primary defence.
4856 int bottom, top, pwlen, i;
4859 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4861 bottom = 0; /* zero length passwords are OK! :-) */
4864 bottom = pwlen & ~7;
4868 assert(pwlen >= bottom && pwlen <= top);
4870 randomstr = snewn(top + 1, char);
4872 for (i = bottom; i <= top; i++) {
4874 defer_packet(ssh, s->pwpkt_type,
4875 PKT_STR,s->cur_prompt->prompts[0]->result,
4878 for (j = 0; j < i; j++) {
4880 randomstr[j] = random_byte();
4881 } while (randomstr[j] == '\0');
4883 randomstr[i] = '\0';
4884 defer_packet(ssh, SSH1_MSG_IGNORE,
4885 PKT_STR, randomstr, PKT_END);
4888 logevent("Sending password with camouflage packets");
4889 ssh_pkt_defersend(ssh);
4892 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4894 * The server can't deal with SSH1_MSG_IGNORE
4895 * but can deal with padded passwords, so we
4896 * can use the secondary defence.
4902 len = strlen(s->cur_prompt->prompts[0]->result);
4903 if (len < sizeof(string)) {
4905 strcpy(string, s->cur_prompt->prompts[0]->result);
4906 len++; /* cover the zero byte */
4907 while (len < sizeof(string)) {
4908 string[len++] = (char) random_byte();
4911 ss = s->cur_prompt->prompts[0]->result;
4913 logevent("Sending length-padded password");
4914 send_packet(ssh, s->pwpkt_type,
4915 PKT_INT, len, PKT_DATA, ss, len,
4919 * The server is believed unable to cope with
4920 * any of our password camouflage methods.
4923 len = strlen(s->cur_prompt->prompts[0]->result);
4924 logevent("Sending unpadded password");
4925 send_packet(ssh, s->pwpkt_type,
4927 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4931 send_packet(ssh, s->pwpkt_type,
4932 PKT_STR, s->cur_prompt->prompts[0]->result,
4935 logevent("Sent password");
4936 free_prompts(s->cur_prompt);
4938 if (pktin->type == SSH1_SMSG_FAILURE) {
4939 if (flags & FLAG_VERBOSE)
4940 c_write_str(ssh, "Access denied\r\n");
4941 logevent("Authentication refused");
4942 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4943 bombout(("Strange packet received, type %d", pktin->type));
4949 if (s->publickey_blob) {
4950 sfree(s->publickey_blob);
4951 sfree(s->publickey_comment);
4954 logevent("Authentication successful");
4959 static void ssh_channel_try_eof(struct ssh_channel *c)
4962 assert(c->pending_eof); /* precondition for calling us */
4964 return; /* can't close: not even opened yet */
4965 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4966 return; /* can't send EOF: pending outgoing data */
4968 c->pending_eof = FALSE; /* we're about to send it */
4969 if (ssh->version == 1) {
4970 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4972 c->closes |= CLOSES_SENT_EOF;
4974 struct Packet *pktout;
4975 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4976 ssh2_pkt_adduint32(pktout, c->remoteid);
4977 ssh2_pkt_send(ssh, pktout);
4978 c->closes |= CLOSES_SENT_EOF;
4979 ssh2_channel_check_close(c);
4983 Conf *sshfwd_get_conf(struct ssh_channel *c)
4989 void sshfwd_write_eof(struct ssh_channel *c)
4993 if (ssh->state == SSH_STATE_CLOSED)
4996 if (c->closes & CLOSES_SENT_EOF)
4999 c->pending_eof = TRUE;
5000 ssh_channel_try_eof(c);
5003 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
5007 if (ssh->state == SSH_STATE_CLOSED)
5012 x11_close(c->u.x11.xconn);
5013 logeventf(ssh, "Forwarded X11 connection terminated due to local "
5017 case CHAN_SOCKDATA_DORMANT:
5018 pfd_close(c->u.pfd.pf);
5019 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
5022 c->type = CHAN_ZOMBIE;
5023 c->pending_eof = FALSE; /* this will confuse a zombie channel */
5025 ssh2_channel_check_close(c);
5028 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5032 if (ssh->state == SSH_STATE_CLOSED)
5035 return ssh_send_channel_data(c, buf, len);
5038 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5042 if (ssh->state == SSH_STATE_CLOSED)
5045 ssh_channel_unthrottle(c, bufsize);
5048 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5050 struct queued_handler *qh = ssh->qhead;
5054 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5057 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5058 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5061 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5062 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5066 ssh->qhead = qh->next;
5068 if (ssh->qhead->msg1 > 0) {
5069 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5070 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5072 if (ssh->qhead->msg2 > 0) {
5073 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5074 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5077 ssh->qhead = ssh->qtail = NULL;
5080 qh->handler(ssh, pktin, qh->ctx);
5085 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5086 chandler_fn_t handler, void *ctx)
5088 struct queued_handler *qh;
5090 qh = snew(struct queued_handler);
5093 qh->handler = handler;
5097 if (ssh->qtail == NULL) {
5101 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5102 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5105 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5106 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5109 ssh->qtail->next = qh;
5114 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5116 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5118 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5119 SSH2_MSG_REQUEST_SUCCESS)) {
5120 logeventf(ssh, "Remote port forwarding from %s enabled",
5123 logeventf(ssh, "Remote port forwarding from %s refused",
5126 rpf = del234(ssh->rportfwds, pf);
5128 pf->pfrec->remote = NULL;
5133 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5136 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5139 pf->share_ctx = share_ctx;
5140 pf->shost = dupstr(shost);
5142 pf->sportdesc = NULL;
5143 if (!ssh->rportfwds) {
5144 assert(ssh->version == 2);
5145 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5147 if (add234(ssh->rportfwds, pf) != pf) {
5155 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5158 share_got_pkt_from_server(ctx, pktin->type,
5159 pktin->body, pktin->length);
5162 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5164 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5165 ssh_sharing_global_request_response, share_ctx);
5168 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5170 struct ssh_portfwd *epf;
5174 if (!ssh->portfwds) {
5175 ssh->portfwds = newtree234(ssh_portcmp);
5178 * Go through the existing port forwardings and tag them
5179 * with status==DESTROY. Any that we want to keep will be
5180 * re-enabled (status==KEEP) as we go through the
5181 * configuration and find out which bits are the same as
5184 struct ssh_portfwd *epf;
5186 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5187 epf->status = DESTROY;
5190 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5192 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5193 char *kp, *kp2, *vp, *vp2;
5194 char address_family, type;
5195 int sport,dport,sserv,dserv;
5196 char *sports, *dports, *saddr, *host;
5200 address_family = 'A';
5202 if (*kp == 'A' || *kp == '4' || *kp == '6')
5203 address_family = *kp++;
5204 if (*kp == 'L' || *kp == 'R')
5207 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5209 * There's a colon in the middle of the source port
5210 * string, which means that the part before it is
5211 * actually a source address.
5213 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5214 saddr = host_strduptrim(saddr_tmp);
5221 sport = atoi(sports);
5225 sport = net_service_lookup(sports);
5227 logeventf(ssh, "Service lookup failed for source"
5228 " port \"%s\"", sports);
5232 if (type == 'L' && !strcmp(val, "D")) {
5233 /* dynamic forwarding */
5240 /* ordinary forwarding */
5242 vp2 = vp + host_strcspn(vp, ":");
5243 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5247 dport = atoi(dports);
5251 dport = net_service_lookup(dports);
5253 logeventf(ssh, "Service lookup failed for destination"
5254 " port \"%s\"", dports);
5259 if (sport && dport) {
5260 /* Set up a description of the source port. */
5261 struct ssh_portfwd *pfrec, *epfrec;
5263 pfrec = snew(struct ssh_portfwd);
5265 pfrec->saddr = saddr;
5266 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5267 pfrec->sport = sport;
5268 pfrec->daddr = host;
5269 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5270 pfrec->dport = dport;
5271 pfrec->local = NULL;
5272 pfrec->remote = NULL;
5273 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5274 address_family == '6' ? ADDRTYPE_IPV6 :
5277 epfrec = add234(ssh->portfwds, pfrec);
5278 if (epfrec != pfrec) {
5279 if (epfrec->status == DESTROY) {
5281 * We already have a port forwarding up and running
5282 * with precisely these parameters. Hence, no need
5283 * to do anything; simply re-tag the existing one
5286 epfrec->status = KEEP;
5289 * Anything else indicates that there was a duplicate
5290 * in our input, which we'll silently ignore.
5292 free_portfwd(pfrec);
5294 pfrec->status = CREATE;
5303 * Now go through and destroy any port forwardings which were
5306 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5307 if (epf->status == DESTROY) {
5310 message = dupprintf("%s port forwarding from %s%s%d",
5311 epf->type == 'L' ? "local" :
5312 epf->type == 'R' ? "remote" : "dynamic",
5313 epf->saddr ? epf->saddr : "",
5314 epf->saddr ? ":" : "",
5317 if (epf->type != 'D') {
5318 char *msg2 = dupprintf("%s to %s:%d", message,
5319 epf->daddr, epf->dport);
5324 logeventf(ssh, "Cancelling %s", message);
5327 /* epf->remote or epf->local may be NULL if setting up a
5328 * forwarding failed. */
5330 struct ssh_rportfwd *rpf = epf->remote;
5331 struct Packet *pktout;
5334 * Cancel the port forwarding at the server
5337 if (ssh->version == 1) {
5339 * We cannot cancel listening ports on the
5340 * server side in SSH-1! There's no message
5341 * to support it. Instead, we simply remove
5342 * the rportfwd record from the local end
5343 * so that any connections the server tries
5344 * to make on it are rejected.
5347 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5348 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5349 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5351 ssh2_pkt_addstring(pktout, epf->saddr);
5352 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5353 /* XXX: rport_acceptall may not represent
5354 * what was used to open the original connection,
5355 * since it's reconfigurable. */
5356 ssh2_pkt_addstring(pktout, "");
5358 ssh2_pkt_addstring(pktout, "localhost");
5360 ssh2_pkt_adduint32(pktout, epf->sport);
5361 ssh2_pkt_send(ssh, pktout);
5364 del234(ssh->rportfwds, rpf);
5366 } else if (epf->local) {
5367 pfl_terminate(epf->local);
5370 delpos234(ssh->portfwds, i);
5372 i--; /* so we don't skip one in the list */
5376 * And finally, set up any new port forwardings (status==CREATE).
5378 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5379 if (epf->status == CREATE) {
5380 char *sportdesc, *dportdesc;
5381 sportdesc = dupprintf("%s%s%s%s%d%s",
5382 epf->saddr ? epf->saddr : "",
5383 epf->saddr ? ":" : "",
5384 epf->sserv ? epf->sserv : "",
5385 epf->sserv ? "(" : "",
5387 epf->sserv ? ")" : "");
5388 if (epf->type == 'D') {
5391 dportdesc = dupprintf("%s:%s%s%d%s",
5393 epf->dserv ? epf->dserv : "",
5394 epf->dserv ? "(" : "",
5396 epf->dserv ? ")" : "");
5399 if (epf->type == 'L') {
5400 char *err = pfl_listen(epf->daddr, epf->dport,
5401 epf->saddr, epf->sport,
5402 ssh, conf, &epf->local,
5403 epf->addressfamily);
5405 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5406 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5407 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5408 sportdesc, dportdesc,
5409 err ? " failed: " : "", err ? err : "");
5412 } else if (epf->type == 'D') {
5413 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5414 ssh, conf, &epf->local,
5415 epf->addressfamily);
5417 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5418 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5419 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5421 err ? " failed: " : "", err ? err : "");
5426 struct ssh_rportfwd *pf;
5429 * Ensure the remote port forwardings tree exists.
5431 if (!ssh->rportfwds) {
5432 if (ssh->version == 1)
5433 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5435 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5438 pf = snew(struct ssh_rportfwd);
5439 pf->share_ctx = NULL;
5440 pf->dhost = dupstr(epf->daddr);
5441 pf->dport = epf->dport;
5443 pf->shost = dupstr(epf->saddr);
5444 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5445 pf->shost = dupstr("");
5447 pf->shost = dupstr("localhost");
5449 pf->sport = epf->sport;
5450 if (add234(ssh->rportfwds, pf) != pf) {
5451 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5452 epf->daddr, epf->dport);
5455 logeventf(ssh, "Requesting remote port %s"
5456 " forward to %s", sportdesc, dportdesc);
5458 pf->sportdesc = sportdesc;
5463 if (ssh->version == 1) {
5464 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5465 PKT_INT, epf->sport,
5466 PKT_STR, epf->daddr,
5467 PKT_INT, epf->dport,
5469 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5471 ssh_rportfwd_succfail, pf);
5473 struct Packet *pktout;
5474 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5475 ssh2_pkt_addstring(pktout, "tcpip-forward");
5476 ssh2_pkt_addbool(pktout, 1);/* want reply */
5477 ssh2_pkt_addstring(pktout, pf->shost);
5478 ssh2_pkt_adduint32(pktout, pf->sport);
5479 ssh2_pkt_send(ssh, pktout);
5481 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5482 SSH2_MSG_REQUEST_FAILURE,
5483 ssh_rportfwd_succfail, pf);
5492 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5495 int stringlen, bufsize;
5497 ssh_pkt_getstring(pktin, &string, &stringlen);
5498 if (string == NULL) {
5499 bombout(("Incoming terminal data packet was badly formed"));
5503 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5505 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5506 ssh->v1_stdout_throttling = 1;
5507 ssh_throttle_conn(ssh, +1);
5511 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5513 /* Remote side is trying to open a channel to talk to our
5514 * X-Server. Give them back a local channel number. */
5515 struct ssh_channel *c;
5516 int remoteid = ssh_pkt_getuint32(pktin);
5518 logevent("Received X11 connect request");
5519 /* Refuse if X11 forwarding is disabled. */
5520 if (!ssh->X11_fwd_enabled) {
5521 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5522 PKT_INT, remoteid, PKT_END);
5523 logevent("Rejected X11 connect request");
5525 c = snew(struct ssh_channel);
5528 ssh_channel_init(c);
5529 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5530 c->remoteid = remoteid;
5531 c->halfopen = FALSE;
5532 c->type = CHAN_X11; /* identify channel type */
5533 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5534 PKT_INT, c->remoteid, PKT_INT,
5535 c->localid, PKT_END);
5536 logevent("Opened X11 forward channel");
5540 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5542 /* Remote side is trying to open a channel to talk to our
5543 * agent. Give them back a local channel number. */
5544 struct ssh_channel *c;
5545 int remoteid = ssh_pkt_getuint32(pktin);
5547 /* Refuse if agent forwarding is disabled. */
5548 if (!ssh->agentfwd_enabled) {
5549 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5550 PKT_INT, remoteid, PKT_END);
5552 c = snew(struct ssh_channel);
5554 ssh_channel_init(c);
5555 c->remoteid = remoteid;
5556 c->halfopen = FALSE;
5557 c->type = CHAN_AGENT; /* identify channel type */
5558 c->u.a.lensofar = 0;
5559 c->u.a.message = NULL;
5560 c->u.a.outstanding_requests = 0;
5561 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5562 PKT_INT, c->remoteid, PKT_INT, c->localid,
5567 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5569 /* Remote side is trying to open a channel to talk to a
5570 * forwarded port. Give them back a local channel number. */
5571 struct ssh_rportfwd pf, *pfp;
5577 remoteid = ssh_pkt_getuint32(pktin);
5578 ssh_pkt_getstring(pktin, &host, &hostsize);
5579 port = ssh_pkt_getuint32(pktin);
5581 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5583 pfp = find234(ssh->rportfwds, &pf, NULL);
5586 logeventf(ssh, "Rejected remote port open request for %s:%d",
5588 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5589 PKT_INT, remoteid, PKT_END);
5591 struct ssh_channel *c = snew(struct ssh_channel);
5594 logeventf(ssh, "Received remote port open request for %s:%d",
5596 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5597 c, ssh->conf, pfp->pfrec->addressfamily);
5599 logeventf(ssh, "Port open failed: %s", err);
5602 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5603 PKT_INT, remoteid, PKT_END);
5605 ssh_channel_init(c);
5606 c->remoteid = remoteid;
5607 c->halfopen = FALSE;
5608 c->type = CHAN_SOCKDATA; /* identify channel type */
5609 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5610 PKT_INT, c->remoteid, PKT_INT,
5611 c->localid, PKT_END);
5612 logevent("Forwarded port opened successfully");
5619 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5621 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5622 unsigned int localid = ssh_pkt_getuint32(pktin);
5623 struct ssh_channel *c;
5625 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5626 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5627 c->remoteid = localid;
5628 c->halfopen = FALSE;
5629 c->type = CHAN_SOCKDATA;
5630 c->throttling_conn = 0;
5631 pfd_confirm(c->u.pfd.pf);
5634 if (c && c->pending_eof) {
5636 * We have a pending close on this channel,
5637 * which we decided on before the server acked
5638 * the channel open. So now we know the
5639 * remoteid, we can close it again.
5641 ssh_channel_try_eof(c);
5645 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5647 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5648 struct ssh_channel *c;
5650 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5651 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5652 logevent("Forwarded connection refused by server");
5653 pfd_close(c->u.pfd.pf);
5654 del234(ssh->channels, c);
5659 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5661 /* Remote side closes a channel. */
5662 unsigned i = ssh_pkt_getuint32(pktin);
5663 struct ssh_channel *c;
5664 c = find234(ssh->channels, &i, ssh_channelfind);
5665 if (c && !c->halfopen) {
5667 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5668 !(c->closes & CLOSES_RCVD_EOF)) {
5670 * Received CHANNEL_CLOSE, which we translate into
5673 int send_close = FALSE;
5675 c->closes |= CLOSES_RCVD_EOF;
5680 x11_send_eof(c->u.x11.xconn);
5686 pfd_send_eof(c->u.pfd.pf);
5695 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5696 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5698 c->closes |= CLOSES_SENT_EOF;
5702 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5703 !(c->closes & CLOSES_RCVD_CLOSE)) {
5705 if (!(c->closes & CLOSES_SENT_EOF)) {
5706 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5707 " for which we never sent CHANNEL_CLOSE\n", i));
5710 c->closes |= CLOSES_RCVD_CLOSE;
5713 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5714 !(c->closes & CLOSES_SENT_CLOSE)) {
5715 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5716 PKT_INT, c->remoteid, PKT_END);
5717 c->closes |= CLOSES_SENT_CLOSE;
5720 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5721 ssh_channel_destroy(c);
5723 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5724 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5725 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5731 * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel.
5733 static int ssh_agent_channel_data(struct ssh_channel *c, char *data,
5736 while (length > 0) {
5737 if (c->u.a.lensofar < 4) {
5738 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)length);
5739 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
5742 c->u.a.lensofar += l;
5744 if (c->u.a.lensofar == 4) {
5745 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
5746 c->u.a.message = snewn(c->u.a.totallen, unsigned char);
5747 memcpy(c->u.a.message, c->u.a.msglen, 4);
5749 if (c->u.a.lensofar >= 4 && length > 0) {
5750 unsigned int l = min(c->u.a.totallen - c->u.a.lensofar,
5752 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
5755 c->u.a.lensofar += l;
5757 if (c->u.a.lensofar == c->u.a.totallen) {
5760 c->u.a.outstanding_requests++;
5761 if (agent_query(c->u.a.message, c->u.a.totallen, &reply, &replylen,
5762 ssh_agentf_callback, c))
5763 ssh_agentf_callback(c, reply, replylen);
5764 sfree(c->u.a.message);
5765 c->u.a.message = NULL;
5766 c->u.a.lensofar = 0;
5769 return 0; /* agent channels never back up */
5772 static int ssh_channel_data(struct ssh_channel *c, int is_stderr,
5773 char *data, int length)
5776 case CHAN_MAINSESSION:
5777 return from_backend(c->ssh->frontend, is_stderr, data, length);
5779 return x11_send(c->u.x11.xconn, data, length);
5781 return pfd_send(c->u.pfd.pf, data, length);
5783 return ssh_agent_channel_data(c, data, length);
5788 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5790 /* Data sent down one of our channels. */
5791 int i = ssh_pkt_getuint32(pktin);
5794 struct ssh_channel *c;
5796 ssh_pkt_getstring(pktin, &p, &len);
5798 c = find234(ssh->channels, &i, ssh_channelfind);
5800 int bufsize = ssh_channel_data(c, FALSE, p, len);
5801 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5802 c->throttling_conn = 1;
5803 ssh_throttle_conn(ssh, +1);
5808 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5810 ssh->exitcode = ssh_pkt_getuint32(pktin);
5811 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5812 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5814 * In case `helpful' firewalls or proxies tack
5815 * extra human-readable text on the end of the
5816 * session which we might mistake for another
5817 * encrypted packet, we close the session once
5818 * we've sent EXIT_CONFIRMATION.
5820 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5823 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5824 static void ssh1_send_ttymode(void *data,
5825 const struct ssh_ttymode *mode, char *val)
5827 struct Packet *pktout = (struct Packet *)data;
5828 unsigned int arg = 0;
5830 switch (mode->type) {
5832 arg = ssh_tty_parse_specchar(val);
5835 arg = ssh_tty_parse_boolean(val);
5838 ssh2_pkt_addbyte(pktout, mode->opcode);
5839 ssh2_pkt_addbyte(pktout, arg);
5842 int ssh_agent_forwarding_permitted(Ssh ssh)
5844 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5847 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5848 struct Packet *pktin)
5850 crBegin(ssh->do_ssh1_connection_crstate);
5852 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5853 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5854 ssh1_smsg_stdout_stderr_data;
5856 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5857 ssh1_msg_channel_open_confirmation;
5858 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5859 ssh1_msg_channel_open_failure;
5860 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5861 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5862 ssh1_msg_channel_close;
5863 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5864 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5866 if (ssh_agent_forwarding_permitted(ssh)) {
5867 logevent("Requesting agent forwarding");
5868 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5872 if (pktin->type != SSH1_SMSG_SUCCESS
5873 && pktin->type != SSH1_SMSG_FAILURE) {
5874 bombout(("Protocol confusion"));
5876 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5877 logevent("Agent forwarding refused");
5879 logevent("Agent forwarding enabled");
5880 ssh->agentfwd_enabled = TRUE;
5881 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5885 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5887 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5889 if (!ssh->x11disp) {
5890 /* FIXME: return an error message from x11_setup_display */
5891 logevent("X11 forwarding not enabled: unable to"
5892 " initialise X display");
5894 ssh->x11auth = x11_invent_fake_auth
5895 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5896 ssh->x11auth->disp = ssh->x11disp;
5898 logevent("Requesting X11 forwarding");
5899 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5900 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5901 PKT_STR, ssh->x11auth->protoname,
5902 PKT_STR, ssh->x11auth->datastring,
5903 PKT_INT, ssh->x11disp->screennum,
5906 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5907 PKT_STR, ssh->x11auth->protoname,
5908 PKT_STR, ssh->x11auth->datastring,
5914 if (pktin->type != SSH1_SMSG_SUCCESS
5915 && pktin->type != SSH1_SMSG_FAILURE) {
5916 bombout(("Protocol confusion"));
5918 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5919 logevent("X11 forwarding refused");
5921 logevent("X11 forwarding enabled");
5922 ssh->X11_fwd_enabled = TRUE;
5923 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5928 ssh_setup_portfwd(ssh, ssh->conf);
5929 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5931 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5933 /* Unpick the terminal-speed string. */
5934 /* XXX perhaps we should allow no speeds to be sent. */
5935 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5936 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5937 /* Send the pty request. */
5938 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5939 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5940 ssh_pkt_adduint32(pkt, ssh->term_height);
5941 ssh_pkt_adduint32(pkt, ssh->term_width);
5942 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5943 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5944 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5945 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5946 ssh_pkt_adduint32(pkt, ssh->ispeed);
5947 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5948 ssh_pkt_adduint32(pkt, ssh->ospeed);
5949 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5951 ssh->state = SSH_STATE_INTERMED;
5955 if (pktin->type != SSH1_SMSG_SUCCESS
5956 && pktin->type != SSH1_SMSG_FAILURE) {
5957 bombout(("Protocol confusion"));
5959 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5960 c_write_str(ssh, "Server refused to allocate pty\r\n");
5961 ssh->editing = ssh->echoing = 1;
5963 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5964 ssh->ospeed, ssh->ispeed);
5965 ssh->got_pty = TRUE;
5968 ssh->editing = ssh->echoing = 1;
5971 if (conf_get_int(ssh->conf, CONF_compression)) {
5972 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5976 if (pktin->type != SSH1_SMSG_SUCCESS
5977 && pktin->type != SSH1_SMSG_FAILURE) {
5978 bombout(("Protocol confusion"));
5980 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5981 c_write_str(ssh, "Server refused to compress\r\n");
5983 logevent("Started compression");
5984 ssh->v1_compressing = TRUE;
5985 ssh->cs_comp_ctx = zlib_compress_init();
5986 logevent("Initialised zlib (RFC1950) compression");
5987 ssh->sc_comp_ctx = zlib_decompress_init();
5988 logevent("Initialised zlib (RFC1950) decompression");
5992 * Start the shell or command.
5994 * Special case: if the first-choice command is an SSH-2
5995 * subsystem (hence not usable here) and the second choice
5996 * exists, we fall straight back to that.
5999 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
6001 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
6002 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
6003 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
6004 ssh->fallback_cmd = TRUE;
6007 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6009 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6010 logevent("Started session");
6013 ssh->state = SSH_STATE_SESSION;
6014 if (ssh->size_needed)
6015 ssh_size(ssh, ssh->term_width, ssh->term_height);
6016 if (ssh->eof_needed)
6017 ssh_special(ssh, TS_EOF);
6020 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6022 ssh->channels = newtree234(ssh_channelcmp);
6026 * By this point, most incoming packets are already being
6027 * handled by the dispatch table, and we need only pay
6028 * attention to the unusual ones.
6033 if (pktin->type == SSH1_SMSG_SUCCESS) {
6034 /* may be from EXEC_SHELL on some servers */
6035 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6036 /* may be from EXEC_SHELL on some servers
6037 * if no pty is available or in other odd cases. Ignore */
6039 bombout(("Strange packet received: type %d", pktin->type));
6044 int len = min(inlen, 512);
6045 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6046 PKT_INT, len, PKT_DATA, in, len,
6058 * Handle the top-level SSH-2 protocol.
6060 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6065 ssh_pkt_getstring(pktin, &msg, &msglen);
6066 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6069 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6071 /* log reason code in disconnect message */
6075 ssh_pkt_getstring(pktin, &msg, &msglen);
6076 bombout(("Server sent disconnect message:\n\"%.*s\"",
6077 msglen, NULLTOEMPTY(msg)));
6080 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6082 /* Do nothing, because we're ignoring it! Duhh. */
6085 static void ssh1_protocol_setup(Ssh ssh)
6090 * Most messages are handled by the coroutines.
6092 for (i = 0; i < 256; i++)
6093 ssh->packet_dispatch[i] = NULL;
6096 * These special message types we install handlers for.
6098 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6099 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6100 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6103 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6104 struct Packet *pktin)
6106 const unsigned char *in = (const unsigned char *)vin;
6107 if (ssh->state == SSH_STATE_CLOSED)
6110 if (pktin && ssh->packet_dispatch[pktin->type]) {
6111 ssh->packet_dispatch[pktin->type](ssh, pktin);
6115 if (!ssh->protocol_initial_phase_done) {
6116 if (do_ssh1_login(ssh, in, inlen, pktin))
6117 ssh->protocol_initial_phase_done = TRUE;
6122 do_ssh1_connection(ssh, in, inlen, pktin);
6126 * Utility routines for decoding comma-separated strings in KEXINIT.
6128 static int first_in_commasep_string(char const *needle, char const *haystack,
6132 if (!needle || !haystack) /* protect against null pointers */
6134 needlen = strlen(needle);
6136 if (haylen >= needlen && /* haystack is long enough */
6137 !memcmp(needle, haystack, needlen) && /* initial match */
6138 (haylen == needlen || haystack[needlen] == ',')
6139 /* either , or EOS follows */
6145 static int in_commasep_string(char const *needle, char const *haystack,
6150 if (!needle || !haystack) /* protect against null pointers */
6153 * Is it at the start of the string?
6155 if (first_in_commasep_string(needle, haystack, haylen))
6158 * If not, search for the next comma and resume after that.
6159 * If no comma found, terminate.
6161 p = memchr(haystack, ',', haylen);
6163 /* + 1 to skip over comma */
6164 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6168 * Add a value to the comma-separated string at the end of the packet.
6170 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6172 if (pkt->length - pkt->savedpos > 0)
6173 ssh_pkt_addstring_str(pkt, ",");
6174 ssh_pkt_addstring_str(pkt, data);
6179 * SSH-2 key derivation (RFC 4253 section 7.2).
6181 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6182 char chr, int keylen)
6184 const struct ssh_hash *h = ssh->kex->hash;
6192 /* Round up to the next multiple of hash length. */
6193 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6195 key = snewn(keylen_padded, unsigned char);
6197 /* First hlen bytes. */
6199 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6200 hash_mpint(h, s, K);
6201 h->bytes(s, H, h->hlen);
6202 h->bytes(s, &chr, 1);
6203 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6206 /* Subsequent blocks of hlen bytes. */
6207 if (keylen_padded > h->hlen) {
6211 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6212 hash_mpint(h, s, K);
6213 h->bytes(s, H, h->hlen);
6215 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6216 h->bytes(s, key + offset - h->hlen, h->hlen);
6218 h->final(s2, key + offset);
6224 /* Now clear any extra bytes of key material beyond the length
6225 * we're officially returning, because the caller won't know to
6227 if (keylen_padded > keylen)
6228 smemclr(key + keylen, keylen_padded - keylen);
6234 * Structure for constructing KEXINIT algorithm lists.
6236 #define MAXKEXLIST 16
6237 struct kexinit_algorithm {
6241 const struct ssh_kex *kex;
6245 const struct ssh_signkey *hostkey;
6249 const struct ssh2_cipher *cipher;
6253 const struct ssh_mac *mac;
6256 const struct ssh_compress *comp;
6261 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6262 * If the algorithm is already in the list, return a pointer to its
6263 * entry, otherwise return an entry from the end of the list.
6264 * This assumes that every time a particular name is passed in, it
6265 * comes from the same string constant. If this isn't true, this
6266 * function may need to be rewritten to use strcmp() instead.
6268 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6269 *list, const char *name)
6273 for (i = 0; i < MAXKEXLIST; i++)
6274 if (list[i].name == NULL || list[i].name == name) {
6275 list[i].name = name;
6278 assert(!"No space in KEXINIT list");
6283 * Handle the SSH-2 transport layer.
6285 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6286 struct Packet *pktin)
6288 const unsigned char *in = (const unsigned char *)vin;
6290 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6291 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6294 const char * kexlist_descr[NKEXLIST] = {
6295 "key exchange algorithm", "host key algorithm",
6296 "client-to-server cipher", "server-to-client cipher",
6297 "client-to-server MAC", "server-to-client MAC",
6298 "client-to-server compression method",
6299 "server-to-client compression method" };
6300 struct do_ssh2_transport_state {
6302 int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher;
6303 Bignum p, g, e, f, K;
6306 int kex_init_value, kex_reply_value;
6307 const struct ssh_mac *const *maclist;
6309 const struct ssh2_cipher *cscipher_tobe;
6310 const struct ssh2_cipher *sccipher_tobe;
6311 const struct ssh_mac *csmac_tobe;
6312 const struct ssh_mac *scmac_tobe;
6313 int csmac_etm_tobe, scmac_etm_tobe;
6314 const struct ssh_compress *cscomp_tobe;
6315 const struct ssh_compress *sccomp_tobe;
6316 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6317 int hostkeylen, siglen, rsakeylen;
6318 void *hkey; /* actual host key */
6319 void *rsakey; /* for RSA kex */
6320 void *eckey; /* for ECDH kex */
6321 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6322 int n_preferred_kex;
6323 const struct ssh_kexes *preferred_kex[KEX_MAX];
6325 int preferred_hk[HK_MAX];
6326 int n_preferred_ciphers;
6327 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6328 const struct ssh_compress *preferred_comp;
6329 int userauth_succeeded; /* for delayed compression */
6330 int pending_compression;
6331 int got_session_id, activated_authconn;
6332 struct Packet *pktout;
6336 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6338 crState(do_ssh2_transport_state);
6340 assert(!ssh->bare_connection);
6341 assert(ssh->version == 2);
6345 s->cscipher_tobe = s->sccipher_tobe = NULL;
6346 s->csmac_tobe = s->scmac_tobe = NULL;
6347 s->cscomp_tobe = s->sccomp_tobe = NULL;
6349 s->got_session_id = s->activated_authconn = FALSE;
6350 s->userauth_succeeded = FALSE;
6351 s->pending_compression = FALSE;
6354 * Be prepared to work around the buggy MAC problem.
6356 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6357 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6359 s->maclist = macs, s->nmacs = lenof(macs);
6362 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6365 struct kexinit_algorithm *alg;
6368 * Set up the preferred key exchange. (NULL => warn below here)
6370 s->n_preferred_kex = 0;
6371 for (i = 0; i < KEX_MAX; i++) {
6372 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6374 s->preferred_kex[s->n_preferred_kex++] =
6375 &ssh_diffiehellman_gex;
6378 s->preferred_kex[s->n_preferred_kex++] =
6379 &ssh_diffiehellman_group14;
6382 s->preferred_kex[s->n_preferred_kex++] =
6383 &ssh_diffiehellman_group1;
6386 s->preferred_kex[s->n_preferred_kex++] =
6390 s->preferred_kex[s->n_preferred_kex++] =
6394 /* Flag for later. Don't bother if it's the last in
6396 if (i < KEX_MAX - 1) {
6397 s->preferred_kex[s->n_preferred_kex++] = NULL;
6404 * Set up the preferred host key types. These are just the ids
6405 * in the enum in putty.h, so 'warn below here' is indicated
6408 s->n_preferred_hk = 0;
6409 for (i = 0; i < HK_MAX; i++) {
6410 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i);
6411 /* As above, don't bother with HK_WARN if it's last in the
6413 if (id != HK_WARN || i < HK_MAX - 1)
6414 s->preferred_hk[s->n_preferred_hk++] = id;
6418 * Set up the preferred ciphers. (NULL => warn below here)
6420 s->n_preferred_ciphers = 0;
6421 for (i = 0; i < CIPHER_MAX; i++) {
6422 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6423 case CIPHER_BLOWFISH:
6424 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6427 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6428 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6432 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6435 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6437 case CIPHER_ARCFOUR:
6438 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6440 case CIPHER_CHACHA20:
6441 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6444 /* Flag for later. Don't bother if it's the last in
6446 if (i < CIPHER_MAX - 1) {
6447 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6454 * Set up preferred compression.
6456 if (conf_get_int(ssh->conf, CONF_compression))
6457 s->preferred_comp = &ssh_zlib;
6459 s->preferred_comp = &ssh_comp_none;
6462 * Enable queueing of outgoing auth- or connection-layer
6463 * packets while we are in the middle of a key exchange.
6465 ssh->queueing = TRUE;
6468 * Flag that KEX is in progress.
6470 ssh->kex_in_progress = TRUE;
6472 for (i = 0; i < NKEXLIST; i++)
6473 for (j = 0; j < MAXKEXLIST; j++)
6474 s->kexlists[i][j].name = NULL;
6475 /* List key exchange algorithms. */
6477 for (i = 0; i < s->n_preferred_kex; i++) {
6478 const struct ssh_kexes *k = s->preferred_kex[i];
6479 if (!k) warn = TRUE;
6480 else for (j = 0; j < k->nkexes; j++) {
6481 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6483 alg->u.kex.kex = k->list[j];
6484 alg->u.kex.warn = warn;
6487 /* List server host key algorithms. */
6488 if (!s->got_session_id) {
6490 * In the first key exchange, we list all the algorithms
6491 * we're prepared to cope with, but prefer those algorithms
6492 * for which we have a host key for this host.
6494 * If the host key algorithm is below the warning
6495 * threshold, we warn even if we did already have a key
6496 * for it, on the basis that if the user has just
6497 * reconfigured that host key type to be warned about,
6498 * they surely _do_ want to be alerted that a server
6499 * they're actually connecting to is using it.
6502 for (i = 0; i < s->n_preferred_hk; i++) {
6503 if (s->preferred_hk[i] == HK_WARN)
6505 for (j = 0; j < lenof(hostkey_algs); j++) {
6506 if (hostkey_algs[j].id != s->preferred_hk[i])
6508 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6509 hostkey_algs[j].alg->keytype)) {
6510 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6511 hostkey_algs[j].alg->name);
6512 alg->u.hk.hostkey = hostkey_algs[j].alg;
6513 alg->u.hk.warn = warn;
6518 for (i = 0; i < s->n_preferred_hk; i++) {
6519 if (s->preferred_hk[i] == HK_WARN)
6521 for (j = 0; j < lenof(hostkey_algs); j++) {
6522 if (hostkey_algs[j].id != s->preferred_hk[i])
6524 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6525 hostkey_algs[j].alg->name);
6526 alg->u.hk.hostkey = hostkey_algs[j].alg;
6527 alg->u.hk.warn = warn;
6532 * In subsequent key exchanges, we list only the kex
6533 * algorithm that was selected in the first key exchange,
6534 * so that we keep getting the same host key and hence
6535 * don't have to interrupt the user's session to ask for
6539 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6540 ssh->hostkey->name);
6541 alg->u.hk.hostkey = ssh->hostkey;
6542 alg->u.hk.warn = FALSE;
6544 /* List encryption algorithms (client->server then server->client). */
6545 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6548 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6549 alg->u.cipher.cipher = NULL;
6550 alg->u.cipher.warn = warn;
6551 #endif /* FUZZING */
6552 for (i = 0; i < s->n_preferred_ciphers; i++) {
6553 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6554 if (!c) warn = TRUE;
6555 else for (j = 0; j < c->nciphers; j++) {
6556 alg = ssh2_kexinit_addalg(s->kexlists[k],
6558 alg->u.cipher.cipher = c->list[j];
6559 alg->u.cipher.warn = warn;
6563 /* List MAC algorithms (client->server then server->client). */
6564 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6566 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6567 alg->u.mac.mac = NULL;
6568 alg->u.mac.etm = FALSE;
6569 #endif /* FUZZING */
6570 for (i = 0; i < s->nmacs; i++) {
6571 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6572 alg->u.mac.mac = s->maclist[i];
6573 alg->u.mac.etm = FALSE;
6575 for (i = 0; i < s->nmacs; i++)
6576 /* For each MAC, there may also be an ETM version,
6577 * which we list second. */
6578 if (s->maclist[i]->etm_name) {
6579 alg = ssh2_kexinit_addalg(s->kexlists[j],
6580 s->maclist[i]->etm_name);
6581 alg->u.mac.mac = s->maclist[i];
6582 alg->u.mac.etm = TRUE;
6585 /* List client->server compression algorithms,
6586 * then server->client compression algorithms. (We use the
6587 * same set twice.) */
6588 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6589 assert(lenof(compressions) > 1);
6590 /* Prefer non-delayed versions */
6591 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6592 alg->u.comp = s->preferred_comp;
6593 /* We don't even list delayed versions of algorithms until
6594 * they're allowed to be used, to avoid a race. See the end of
6596 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6597 alg = ssh2_kexinit_addalg(s->kexlists[j],
6598 s->preferred_comp->delayed_name);
6599 alg->u.comp = s->preferred_comp;
6601 for (i = 0; i < lenof(compressions); i++) {
6602 const struct ssh_compress *c = compressions[i];
6603 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6605 if (s->userauth_succeeded && c->delayed_name) {
6606 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6612 * Construct and send our key exchange packet.
6614 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6615 for (i = 0; i < 16; i++)
6616 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6617 for (i = 0; i < NKEXLIST; i++) {
6618 ssh2_pkt_addstring_start(s->pktout);
6619 for (j = 0; j < MAXKEXLIST; j++) {
6620 if (s->kexlists[i][j].name == NULL) break;
6621 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6624 /* List client->server languages. Empty list. */
6625 ssh2_pkt_addstring_start(s->pktout);
6626 /* List server->client languages. Empty list. */
6627 ssh2_pkt_addstring_start(s->pktout);
6628 /* First KEX packet does _not_ follow, because we're not that brave. */
6629 ssh2_pkt_addbool(s->pktout, FALSE);
6631 ssh2_pkt_adduint32(s->pktout, 0);
6634 s->our_kexinitlen = s->pktout->length - 5;
6635 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6636 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6638 ssh2_pkt_send_noqueue(ssh, s->pktout);
6641 crWaitUntilV(pktin);
6644 * Now examine the other side's KEXINIT to see what we're up
6651 if (pktin->type != SSH2_MSG_KEXINIT) {
6652 bombout(("expected key exchange packet from server"));
6656 ssh->hostkey = NULL;
6657 s->cscipher_tobe = NULL;
6658 s->sccipher_tobe = NULL;
6659 s->csmac_tobe = NULL;
6660 s->scmac_tobe = NULL;
6661 s->cscomp_tobe = NULL;
6662 s->sccomp_tobe = NULL;
6663 s->warn_kex = s->warn_hk = FALSE;
6664 s->warn_cscipher = s->warn_sccipher = FALSE;
6666 pktin->savedpos += 16; /* skip garbage cookie */
6669 for (i = 0; i < NKEXLIST; i++) {
6670 ssh_pkt_getstring(pktin, &str, &len);
6672 bombout(("KEXINIT packet was incomplete"));
6676 /* If we've already selected a cipher which requires a
6677 * particular MAC, then just select that, and don't even
6678 * bother looking through the server's KEXINIT string for
6680 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6681 s->cscipher_tobe->required_mac) {
6682 s->csmac_tobe = s->cscipher_tobe->required_mac;
6683 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6686 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6687 s->sccipher_tobe->required_mac) {
6688 s->scmac_tobe = s->sccipher_tobe->required_mac;
6689 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6693 for (j = 0; j < MAXKEXLIST; j++) {
6694 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6695 if (alg->name == NULL) break;
6696 if (in_commasep_string(alg->name, str, len)) {
6697 /* We've found a matching algorithm. */
6698 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6699 /* Check if we might need to ignore first kex pkt */
6701 !first_in_commasep_string(alg->name, str, len))
6704 if (i == KEXLIST_KEX) {
6705 ssh->kex = alg->u.kex.kex;
6706 s->warn_kex = alg->u.kex.warn;
6707 } else if (i == KEXLIST_HOSTKEY) {
6708 ssh->hostkey = alg->u.hk.hostkey;
6709 s->warn_hk = alg->u.hk.warn;
6710 } else if (i == KEXLIST_CSCIPHER) {
6711 s->cscipher_tobe = alg->u.cipher.cipher;
6712 s->warn_cscipher = alg->u.cipher.warn;
6713 } else if (i == KEXLIST_SCCIPHER) {
6714 s->sccipher_tobe = alg->u.cipher.cipher;
6715 s->warn_sccipher = alg->u.cipher.warn;
6716 } else if (i == KEXLIST_CSMAC) {
6717 s->csmac_tobe = alg->u.mac.mac;
6718 s->csmac_etm_tobe = alg->u.mac.etm;
6719 } else if (i == KEXLIST_SCMAC) {
6720 s->scmac_tobe = alg->u.mac.mac;
6721 s->scmac_etm_tobe = alg->u.mac.etm;
6722 } else if (i == KEXLIST_CSCOMP) {
6723 s->cscomp_tobe = alg->u.comp;
6724 } else if (i == KEXLIST_SCCOMP) {
6725 s->sccomp_tobe = alg->u.comp;
6729 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6730 in_commasep_string(alg->u.comp->delayed_name, str, len))
6731 s->pending_compression = TRUE; /* try this later */
6733 bombout(("Couldn't agree a %s (available: %.*s)",
6734 kexlist_descr[i], len, str));
6738 if (i == KEXLIST_HOSTKEY) {
6742 * In addition to deciding which host key we're
6743 * actually going to use, we should make a list of the
6744 * host keys offered by the server which we _don't_
6745 * have cached. These will be offered as cross-
6746 * certification options by ssh_get_specials.
6748 * We also count the key we're currently using for KEX
6749 * as one we've already got, because by the time this
6750 * menu becomes visible, it will be.
6752 ssh->n_uncert_hostkeys = 0;
6754 for (j = 0; j < lenof(hostkey_algs); j++) {
6755 if (hostkey_algs[j].alg != ssh->hostkey &&
6756 in_commasep_string(hostkey_algs[j].alg->name,
6758 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6759 hostkey_algs[j].alg->keytype)) {
6760 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6766 if (s->pending_compression) {
6767 logevent("Server supports delayed compression; "
6768 "will try this later");
6770 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6771 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6772 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6774 ssh->exhash = ssh->kex->hash->init();
6775 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6776 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6777 hash_string(ssh->kex->hash, ssh->exhash,
6778 s->our_kexinit, s->our_kexinitlen);
6779 sfree(s->our_kexinit);
6780 /* Include the type byte in the hash of server's KEXINIT */
6781 hash_string(ssh->kex->hash, ssh->exhash,
6782 pktin->body - 1, pktin->length + 1);
6785 ssh_set_frozen(ssh, 1);
6786 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6788 ssh_dialog_callback, ssh);
6789 if (s->dlgret < 0) {
6793 bombout(("Unexpected data from server while"
6794 " waiting for user response"));
6797 } while (pktin || inlen > 0);
6798 s->dlgret = ssh->user_response;
6800 ssh_set_frozen(ssh, 0);
6801 if (s->dlgret == 0) {
6802 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6812 ssh_set_frozen(ssh, 1);
6815 * Change warning box wording depending on why we chose a
6816 * warning-level host key algorithm. If it's because
6817 * that's all we have *cached*, use the askhk mechanism,
6818 * and list the host keys we could usefully cross-certify.
6819 * Otherwise, use askalg for the standard wording.
6822 for (j = 0; j < ssh->n_uncert_hostkeys; j++) {
6823 const struct ssh_signkey_with_user_pref_id *hktype =
6824 &hostkey_algs[ssh->uncert_hostkeys[j]];
6826 for (k = 0; k < HK_MAX; k++) {
6827 int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k);
6828 if (id == HK_WARN) {
6830 } else if (id == hktype->id) {
6837 char *old_ba = betteralgs;
6838 betteralgs = dupcat(betteralgs, ",",
6840 (const char *)NULL);
6843 betteralgs = dupstr(hktype->alg->name);
6848 s->dlgret = askhk(ssh->frontend, ssh->hostkey->name,
6849 betteralgs, ssh_dialog_callback, ssh);
6852 s->dlgret = askalg(ssh->frontend, "host key type",
6854 ssh_dialog_callback, ssh);
6856 if (s->dlgret < 0) {
6860 bombout(("Unexpected data from server while"
6861 " waiting for user response"));
6864 } while (pktin || inlen > 0);
6865 s->dlgret = ssh->user_response;
6867 ssh_set_frozen(ssh, 0);
6868 if (s->dlgret == 0) {
6869 ssh_disconnect(ssh, "User aborted at host key warning", NULL,
6875 if (s->warn_cscipher) {
6876 ssh_set_frozen(ssh, 1);
6877 s->dlgret = askalg(ssh->frontend,
6878 "client-to-server cipher",
6879 s->cscipher_tobe->name,
6880 ssh_dialog_callback, ssh);
6881 if (s->dlgret < 0) {
6885 bombout(("Unexpected data from server while"
6886 " waiting for user response"));
6889 } while (pktin || inlen > 0);
6890 s->dlgret = ssh->user_response;
6892 ssh_set_frozen(ssh, 0);
6893 if (s->dlgret == 0) {
6894 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6900 if (s->warn_sccipher) {
6901 ssh_set_frozen(ssh, 1);
6902 s->dlgret = askalg(ssh->frontend,
6903 "server-to-client cipher",
6904 s->sccipher_tobe->name,
6905 ssh_dialog_callback, ssh);
6906 if (s->dlgret < 0) {
6910 bombout(("Unexpected data from server while"
6911 " waiting for user response"));
6914 } while (pktin || inlen > 0);
6915 s->dlgret = ssh->user_response;
6917 ssh_set_frozen(ssh, 0);
6918 if (s->dlgret == 0) {
6919 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6925 if (s->ignorepkt) /* first_kex_packet_follows */
6926 crWaitUntilV(pktin); /* Ignore packet */
6929 if (ssh->kex->main_type == KEXTYPE_DH) {
6931 * Work out the number of bits of key we will need from the
6932 * key exchange. We start with the maximum key length of
6938 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6939 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6940 s->nbits = (csbits > scbits ? csbits : scbits);
6942 /* The keys only have hlen-bit entropy, since they're based on
6943 * a hash. So cap the key size at hlen bits. */
6944 if (s->nbits > ssh->kex->hash->hlen * 8)
6945 s->nbits = ssh->kex->hash->hlen * 8;
6948 * If we're doing Diffie-Hellman group exchange, start by
6949 * requesting a group.
6951 if (dh_is_gex(ssh->kex)) {
6952 logevent("Doing Diffie-Hellman group exchange");
6953 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6955 * Work out how big a DH group we will need to allow that
6958 s->pbits = 512 << ((s->nbits - 1) / 64);
6959 if (s->pbits < DH_MIN_SIZE)
6960 s->pbits = DH_MIN_SIZE;
6961 if (s->pbits > DH_MAX_SIZE)
6962 s->pbits = DH_MAX_SIZE;
6963 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6964 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6965 ssh2_pkt_adduint32(s->pktout, s->pbits);
6967 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6968 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6969 ssh2_pkt_adduint32(s->pktout, s->pbits);
6970 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6972 ssh2_pkt_send_noqueue(ssh, s->pktout);
6974 crWaitUntilV(pktin);
6975 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6976 bombout(("expected key exchange group packet from server"));
6979 s->p = ssh2_pkt_getmp(pktin);
6980 s->g = ssh2_pkt_getmp(pktin);
6981 if (!s->p || !s->g) {
6982 bombout(("unable to read mp-ints from incoming group packet"));
6985 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6986 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6987 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6989 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6990 ssh->kex_ctx = dh_setup_group(ssh->kex);
6991 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6992 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6993 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6994 ssh->kex->groupname);
6997 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6998 ssh->kex->hash->text_name);
7000 * Now generate and send e for Diffie-Hellman.
7002 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
7003 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
7004 s->pktout = ssh2_pkt_init(s->kex_init_value);
7005 ssh2_pkt_addmp(s->pktout, s->e);
7006 ssh2_pkt_send_noqueue(ssh, s->pktout);
7008 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
7009 crWaitUntilV(pktin);
7010 if (pktin->type != s->kex_reply_value) {
7011 bombout(("expected key exchange reply packet from server"));
7014 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
7015 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7016 if (!s->hostkeydata) {
7017 bombout(("unable to parse key exchange reply packet"));
7020 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7021 s->hostkeydata, s->hostkeylen);
7022 s->f = ssh2_pkt_getmp(pktin);
7024 bombout(("unable to parse key exchange reply packet"));
7027 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7029 bombout(("unable to parse key exchange reply packet"));
7034 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
7036 bombout(("key exchange reply failed validation: %s", err));
7040 s->K = dh_find_K(ssh->kex_ctx, s->f);
7042 /* We assume everything from now on will be quick, and it might
7043 * involve user interaction. */
7044 set_busy_status(ssh->frontend, BUSY_NOT);
7046 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7047 if (dh_is_gex(ssh->kex)) {
7048 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7049 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
7050 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
7051 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
7052 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
7053 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
7054 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
7056 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
7057 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
7059 dh_cleanup(ssh->kex_ctx);
7061 if (dh_is_gex(ssh->kex)) {
7065 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
7067 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
7068 ssh_ecdhkex_curve_textname(ssh->kex),
7069 ssh->kex->hash->text_name);
7070 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
7072 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
7074 bombout(("Unable to generate key for ECDH"));
7080 int publicPointLength;
7081 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7083 ssh_ecdhkex_freekey(s->eckey);
7084 bombout(("Unable to encode public key for ECDH"));
7087 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
7088 ssh2_pkt_addstring_start(s->pktout);
7089 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
7093 ssh2_pkt_send_noqueue(ssh, s->pktout);
7095 crWaitUntilV(pktin);
7096 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
7097 ssh_ecdhkex_freekey(s->eckey);
7098 bombout(("expected ECDH reply packet from server"));
7102 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7103 if (!s->hostkeydata) {
7104 bombout(("unable to parse ECDH reply packet"));
7107 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
7108 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7109 s->hostkeydata, s->hostkeylen);
7113 int publicPointLength;
7114 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7116 ssh_ecdhkex_freekey(s->eckey);
7117 bombout(("Unable to encode public key for ECDH hash"));
7120 hash_string(ssh->kex->hash, ssh->exhash,
7121 publicPoint, publicPointLength);
7128 ssh_pkt_getstring(pktin, &keydata, &keylen);
7130 bombout(("unable to parse ECDH reply packet"));
7133 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7134 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7136 ssh_ecdhkex_freekey(s->eckey);
7137 bombout(("point received in ECDH was not valid"));
7142 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7144 bombout(("unable to parse key exchange reply packet"));
7148 ssh_ecdhkex_freekey(s->eckey);
7150 logeventf(ssh, "Doing RSA key exchange with hash %s",
7151 ssh->kex->hash->text_name);
7152 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7154 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7157 crWaitUntilV(pktin);
7158 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7159 bombout(("expected RSA public key packet from server"));
7163 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7164 if (!s->hostkeydata) {
7165 bombout(("unable to parse RSA public key packet"));
7168 hash_string(ssh->kex->hash, ssh->exhash,
7169 s->hostkeydata, s->hostkeylen);
7170 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7171 s->hostkeydata, s->hostkeylen);
7175 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7177 bombout(("unable to parse RSA public key packet"));
7180 s->rsakeydata = snewn(s->rsakeylen, char);
7181 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7184 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7186 sfree(s->rsakeydata);
7187 bombout(("unable to parse RSA public key from server"));
7191 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7194 * Next, set up a shared secret K, of precisely KLEN -
7195 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7196 * RSA key modulus and HLEN is the bit length of the hash
7200 int klen = ssh_rsakex_klen(s->rsakey);
7201 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7203 unsigned char *kstr1, *kstr2, *outstr;
7204 int kstr1len, kstr2len, outstrlen;
7206 s->K = bn_power_2(nbits - 1);
7208 for (i = 0; i < nbits; i++) {
7210 byte = random_byte();
7212 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7216 * Encode this as an mpint.
7218 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7219 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7220 PUT_32BIT(kstr2, kstr1len);
7221 memcpy(kstr2 + 4, kstr1, kstr1len);
7224 * Encrypt it with the given RSA key.
7226 outstrlen = (klen + 7) / 8;
7227 outstr = snewn(outstrlen, unsigned char);
7228 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7229 outstr, outstrlen, s->rsakey);
7232 * And send it off in a return packet.
7234 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7235 ssh2_pkt_addstring_start(s->pktout);
7236 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7237 ssh2_pkt_send_noqueue(ssh, s->pktout);
7239 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7246 ssh_rsakex_freekey(s->rsakey);
7248 crWaitUntilV(pktin);
7249 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7250 sfree(s->rsakeydata);
7251 bombout(("expected signature packet from server"));
7255 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7257 bombout(("unable to parse signature packet"));
7261 sfree(s->rsakeydata);
7264 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7265 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7266 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7268 ssh->kex_ctx = NULL;
7271 debug(("Exchange hash is:\n"));
7272 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7276 bombout(("Server's host key is invalid"));
7280 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7281 (char *)s->exchange_hash,
7282 ssh->kex->hash->hlen)) {
7284 bombout(("Server's host key did not match the signature supplied"));
7289 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7290 if (!s->got_session_id) {
7292 * Make a note of any other host key formats that are available.
7295 int i, j, nkeys = 0;
7297 for (i = 0; i < lenof(hostkey_algs); i++) {
7298 if (hostkey_algs[i].alg == ssh->hostkey)
7301 for (j = 0; j < ssh->n_uncert_hostkeys; j++)
7302 if (ssh->uncert_hostkeys[j] == i)
7305 if (j < ssh->n_uncert_hostkeys) {
7308 newlist = dupprintf("%s/%s", list,
7309 hostkey_algs[i].alg->name);
7311 newlist = dupprintf("%s", hostkey_algs[i].alg->name);
7319 "Server also has %s host key%s, but we "
7320 "don't know %s", list,
7321 nkeys > 1 ? "s" : "",
7322 nkeys > 1 ? "any of them" : "it");
7328 * Authenticate remote host: verify host key. (We've already
7329 * checked the signature of the exchange hash.)
7331 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7332 logevent("Host key fingerprint is:");
7333 logevent(s->fingerprint);
7334 /* First check against manually configured host keys. */
7335 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7336 ssh->hostkey, s->hkey);
7337 if (s->dlgret == 0) { /* did not match */
7338 bombout(("Host key did not appear in manually configured list"));
7340 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7341 ssh_set_frozen(ssh, 1);
7342 s->dlgret = verify_ssh_host_key(ssh->frontend,
7343 ssh->savedhost, ssh->savedport,
7344 ssh->hostkey->keytype, s->keystr,
7346 ssh_dialog_callback, ssh);
7350 if (s->dlgret < 0) {
7354 bombout(("Unexpected data from server while waiting"
7355 " for user host key response"));
7358 } while (pktin || inlen > 0);
7359 s->dlgret = ssh->user_response;
7361 ssh_set_frozen(ssh, 0);
7362 if (s->dlgret == 0) {
7363 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7368 sfree(s->fingerprint);
7370 * Save this host key, to check against the one presented in
7371 * subsequent rekeys.
7373 ssh->hostkey_str = s->keystr;
7374 } else if (ssh->cross_certifying) {
7375 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7376 logevent("Storing additional host key for this host:");
7377 logevent(s->fingerprint);
7378 store_host_key(ssh->savedhost, ssh->savedport,
7379 ssh->hostkey->keytype, s->keystr);
7380 ssh->cross_certifying = FALSE;
7382 * Don't forget to store the new key as the one we'll be
7383 * re-checking in future normal rekeys.
7385 ssh->hostkey_str = s->keystr;
7388 * In a rekey, we never present an interactive host key
7389 * verification request to the user. Instead, we simply
7390 * enforce that the key we're seeing this time is identical to
7391 * the one we saw before.
7393 if (strcmp(ssh->hostkey_str, s->keystr)) {
7395 bombout(("Host key was different in repeat key exchange"));
7401 ssh->hostkey->freekey(s->hkey);
7404 * The exchange hash from the very first key exchange is also
7405 * the session id, used in session key construction and
7408 if (!s->got_session_id) {
7409 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7410 memcpy(ssh->v2_session_id, s->exchange_hash,
7411 sizeof(s->exchange_hash));
7412 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7413 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7414 s->got_session_id = TRUE;
7418 * Send SSH2_MSG_NEWKEYS.
7420 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7421 ssh2_pkt_send_noqueue(ssh, s->pktout);
7422 ssh->outgoing_data_size = 0; /* start counting from here */
7425 * We've sent client NEWKEYS, so create and initialise
7426 * client-to-server session keys.
7428 if (ssh->cs_cipher_ctx)
7429 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7430 ssh->cscipher = s->cscipher_tobe;
7431 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7433 if (ssh->cs_mac_ctx)
7434 ssh->csmac->free_context(ssh->cs_mac_ctx);
7435 ssh->csmac = s->csmac_tobe;
7436 ssh->csmac_etm = s->csmac_etm_tobe;
7438 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7440 if (ssh->cs_comp_ctx)
7441 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7442 ssh->cscomp = s->cscomp_tobe;
7443 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7446 * Set IVs on client-to-server keys. Here we use the exchange
7447 * hash from the _first_ key exchange.
7449 if (ssh->cscipher) {
7452 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7453 ssh->cscipher->padded_keybytes);
7454 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7455 smemclr(key, ssh->cscipher->padded_keybytes);
7458 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7459 ssh->cscipher->blksize);
7460 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7461 smemclr(key, ssh->cscipher->blksize);
7467 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7468 ssh->csmac->keylen);
7469 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7470 smemclr(key, ssh->csmac->keylen);
7475 logeventf(ssh, "Initialised %.200s client->server encryption",
7476 ssh->cscipher->text_name);
7478 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7479 ssh->csmac->text_name,
7480 ssh->csmac_etm ? " (in ETM mode)" : "",
7481 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7482 if (ssh->cscomp->text_name)
7483 logeventf(ssh, "Initialised %s compression",
7484 ssh->cscomp->text_name);
7487 * Now our end of the key exchange is complete, we can send all
7488 * our queued higher-layer packets.
7490 ssh->queueing = FALSE;
7491 ssh2_pkt_queuesend(ssh);
7494 * Expect SSH2_MSG_NEWKEYS from server.
7496 crWaitUntilV(pktin);
7497 if (pktin->type != SSH2_MSG_NEWKEYS) {
7498 bombout(("expected new-keys packet from server"));
7501 ssh->incoming_data_size = 0; /* start counting from here */
7504 * We've seen server NEWKEYS, so create and initialise
7505 * server-to-client session keys.
7507 if (ssh->sc_cipher_ctx)
7508 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7509 if (s->sccipher_tobe) {
7510 ssh->sccipher = s->sccipher_tobe;
7511 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7514 if (ssh->sc_mac_ctx)
7515 ssh->scmac->free_context(ssh->sc_mac_ctx);
7516 if (s->scmac_tobe) {
7517 ssh->scmac = s->scmac_tobe;
7518 ssh->scmac_etm = s->scmac_etm_tobe;
7519 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7522 if (ssh->sc_comp_ctx)
7523 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7524 ssh->sccomp = s->sccomp_tobe;
7525 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7528 * Set IVs on server-to-client keys. Here we use the exchange
7529 * hash from the _first_ key exchange.
7531 if (ssh->sccipher) {
7534 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7535 ssh->sccipher->padded_keybytes);
7536 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7537 smemclr(key, ssh->sccipher->padded_keybytes);
7540 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7541 ssh->sccipher->blksize);
7542 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7543 smemclr(key, ssh->sccipher->blksize);
7549 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7550 ssh->scmac->keylen);
7551 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7552 smemclr(key, ssh->scmac->keylen);
7556 logeventf(ssh, "Initialised %.200s server->client encryption",
7557 ssh->sccipher->text_name);
7559 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7560 ssh->scmac->text_name,
7561 ssh->scmac_etm ? " (in ETM mode)" : "",
7562 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7563 if (ssh->sccomp->text_name)
7564 logeventf(ssh, "Initialised %s decompression",
7565 ssh->sccomp->text_name);
7568 * Free shared secret.
7573 * Update the specials menu to list the remaining uncertified host
7576 update_specials_menu(ssh->frontend);
7579 * Key exchange is over. Loop straight back round if we have a
7580 * deferred rekey reason.
7582 if (ssh->deferred_rekey_reason) {
7583 logevent(ssh->deferred_rekey_reason);
7585 ssh->deferred_rekey_reason = NULL;
7586 goto begin_key_exchange;
7590 * Otherwise, schedule a timer for our next rekey.
7592 ssh->kex_in_progress = FALSE;
7593 ssh->last_rekey = GETTICKCOUNT();
7594 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7595 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7599 * Now we're encrypting. Begin returning 1 to the protocol main
7600 * function so that other things can run on top of the
7601 * transport. If we ever see a KEXINIT, we must go back to the
7604 * We _also_ go back to the start if we see pktin==NULL and
7605 * inlen negative, because this is a special signal meaning
7606 * `initiate client-driven rekey', and `in' contains a message
7607 * giving the reason for the rekey.
7609 * inlen==-1 means always initiate a rekey;
7610 * inlen==-2 means that userauth has completed successfully and
7611 * we should consider rekeying (for delayed compression).
7613 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7614 (!pktin && inlen < 0))) {
7616 if (!ssh->protocol_initial_phase_done) {
7617 ssh->protocol_initial_phase_done = TRUE;
7619 * Allow authconn to initialise itself.
7621 do_ssh2_authconn(ssh, NULL, 0, NULL);
7626 logevent("Server initiated key re-exchange");
7630 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7631 * delayed compression, if it's available.
7633 * draft-miller-secsh-compression-delayed-00 says that you
7634 * negotiate delayed compression in the first key exchange, and
7635 * both sides start compressing when the server has sent
7636 * USERAUTH_SUCCESS. This has a race condition -- the server
7637 * can't know when the client has seen it, and thus which incoming
7638 * packets it should treat as compressed.
7640 * Instead, we do the initial key exchange without offering the
7641 * delayed methods, but note if the server offers them; when we
7642 * get here, if a delayed method was available that was higher
7643 * on our list than what we got, we initiate a rekey in which we
7644 * _do_ list the delayed methods (and hopefully get it as a
7645 * result). Subsequent rekeys will do the same.
7647 assert(!s->userauth_succeeded); /* should only happen once */
7648 s->userauth_succeeded = TRUE;
7649 if (!s->pending_compression)
7650 /* Can't see any point rekeying. */
7651 goto wait_for_rekey; /* this is utterly horrid */
7652 /* else fall through to rekey... */
7653 s->pending_compression = FALSE;
7656 * Now we've decided to rekey.
7658 * Special case: if the server bug is set that doesn't
7659 * allow rekeying, we give a different log message and
7660 * continue waiting. (If such a server _initiates_ a rekey,
7661 * we process it anyway!)
7663 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7664 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7666 /* Reset the counters, so that at least this message doesn't
7667 * hit the event log _too_ often. */
7668 ssh->outgoing_data_size = 0;
7669 ssh->incoming_data_size = 0;
7670 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7672 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7675 goto wait_for_rekey; /* this is still utterly horrid */
7677 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7680 goto begin_key_exchange;
7686 * Send data on an SSH channel. In SSH-2, this involves buffering it
7689 static int ssh_send_channel_data(struct ssh_channel *c, const char *buf,
7692 if (c->ssh->version == 2) {
7693 bufchain_add(&c->v.v2.outbuffer, buf, len);
7694 return ssh2_try_send(c);
7696 send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA,
7697 PKT_INT, c->remoteid,
7702 * In SSH-1 we can return 0 here - implying that channels are
7703 * never individually throttled - because the only
7704 * circumstance that can cause throttling will be the whole
7705 * SSH connection backing up, in which case _everything_ will
7706 * be throttled as a whole.
7713 * Attempt to send data on an SSH-2 channel.
7715 static int ssh2_try_send(struct ssh_channel *c)
7718 struct Packet *pktout;
7721 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7724 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7725 if ((unsigned)len > c->v.v2.remwindow)
7726 len = c->v.v2.remwindow;
7727 if ((unsigned)len > c->v.v2.remmaxpkt)
7728 len = c->v.v2.remmaxpkt;
7729 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7730 ssh2_pkt_adduint32(pktout, c->remoteid);
7731 ssh2_pkt_addstring_start(pktout);
7732 ssh2_pkt_addstring_data(pktout, data, len);
7733 ssh2_pkt_send(ssh, pktout);
7734 bufchain_consume(&c->v.v2.outbuffer, len);
7735 c->v.v2.remwindow -= len;
7739 * After having sent as much data as we can, return the amount
7742 ret = bufchain_size(&c->v.v2.outbuffer);
7745 * And if there's no data pending but we need to send an EOF, send
7748 if (!ret && c->pending_eof)
7749 ssh_channel_try_eof(c);
7754 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7757 if (c->closes & CLOSES_SENT_EOF)
7758 return; /* don't send on channels we've EOFed */
7759 bufsize = ssh2_try_send(c);
7762 case CHAN_MAINSESSION:
7763 /* stdin need not receive an unthrottle
7764 * notification since it will be polled */
7767 x11_unthrottle(c->u.x11.xconn);
7770 /* agent sockets are request/response and need no
7771 * buffer management */
7774 pfd_unthrottle(c->u.pfd.pf);
7780 static int ssh_is_simple(Ssh ssh)
7783 * We use the 'simple' variant of the SSH protocol if we're asked
7784 * to, except not if we're also doing connection-sharing (either
7785 * tunnelling our packets over an upstream or expecting to be
7786 * tunnelled over ourselves), since then the assumption that we
7787 * have only one channel to worry about is not true after all.
7789 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7790 !ssh->bare_connection && !ssh->connshare);
7794 * Set up most of a new ssh_channel.
7796 static void ssh_channel_init(struct ssh_channel *c)
7799 c->localid = alloc_channel_id(ssh);
7801 c->pending_eof = FALSE;
7802 c->throttling_conn = FALSE;
7803 if (ssh->version == 2) {
7804 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7805 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7806 c->v.v2.chanreq_head = NULL;
7807 c->v.v2.throttle_state = UNTHROTTLED;
7808 bufchain_init(&c->v.v2.outbuffer);
7810 add234(ssh->channels, c);
7814 * Construct the common parts of a CHANNEL_OPEN.
7816 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7819 struct Packet *pktout;
7821 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7822 ssh2_pkt_addstring(pktout, type);
7823 ssh2_pkt_adduint32(pktout, c->localid);
7824 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7825 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7830 * CHANNEL_FAILURE doesn't come with any indication of what message
7831 * caused it, so we have to keep track of the outstanding
7832 * CHANNEL_REQUESTs ourselves.
7834 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7835 cchandler_fn_t handler, void *ctx)
7837 struct outstanding_channel_request *ocr =
7838 snew(struct outstanding_channel_request);
7840 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7841 ocr->handler = handler;
7844 if (!c->v.v2.chanreq_head)
7845 c->v.v2.chanreq_head = ocr;
7847 c->v.v2.chanreq_tail->next = ocr;
7848 c->v.v2.chanreq_tail = ocr;
7852 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7853 * NULL then a reply will be requested and the handler will be called
7854 * when it arrives. The returned packet is ready to have any
7855 * request-specific data added and be sent. Note that if a handler is
7856 * provided, it's essential that the request actually be sent.
7858 * The handler will usually be passed the response packet in pktin. If
7859 * pktin is NULL, this means that no reply will ever be forthcoming
7860 * (e.g. because the entire connection is being destroyed, or because
7861 * the server initiated channel closure before we saw the response)
7862 * and the handler should free any storage it's holding.
7864 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7866 cchandler_fn_t handler, void *ctx)
7868 struct Packet *pktout;
7870 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7871 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7872 ssh2_pkt_adduint32(pktout, c->remoteid);
7873 ssh2_pkt_addstring(pktout, type);
7874 ssh2_pkt_addbool(pktout, handler != NULL);
7875 if (handler != NULL)
7876 ssh2_queue_chanreq_handler(c, handler, ctx);
7880 static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize)
7885 if (ssh->version == 1) {
7886 buflimit = SSH1_BUFFER_LIMIT;
7888 if (ssh_is_simple(ssh))
7891 buflimit = c->v.v2.locmaxwin;
7892 if (bufsize < buflimit)
7893 ssh2_set_window(c, buflimit - bufsize);
7895 if (c->throttling_conn && bufsize <= buflimit) {
7896 c->throttling_conn = 0;
7897 ssh_throttle_conn(ssh, -1);
7902 * Potentially enlarge the window on an SSH-2 channel.
7904 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7906 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7911 * Never send WINDOW_ADJUST for a channel that the remote side has
7912 * already sent EOF on; there's no point, since it won't be
7913 * sending any more data anyway. Ditto if _we've_ already sent
7916 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7920 * Also, never widen the window for an X11 channel when we're
7921 * still waiting to see its initial auth and may yet hand it off
7924 if (c->type == CHAN_X11 && c->u.x11.initial)
7928 * If the remote end has a habit of ignoring maxpkt, limit the
7929 * window so that it has no choice (assuming it doesn't ignore the
7932 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7933 newwin = OUR_V2_MAXPKT;
7936 * Only send a WINDOW_ADJUST if there's significantly more window
7937 * available than the other end thinks there is. This saves us
7938 * sending a WINDOW_ADJUST for every character in a shell session.
7940 * "Significant" is arbitrarily defined as half the window size.
7942 if (newwin / 2 >= c->v.v2.locwindow) {
7943 struct Packet *pktout;
7947 * In order to keep track of how much window the client
7948 * actually has available, we'd like it to acknowledge each
7949 * WINDOW_ADJUST. We can't do that directly, so we accompany
7950 * it with a CHANNEL_REQUEST that has to be acknowledged.
7952 * This is only necessary if we're opening the window wide.
7953 * If we're not, then throughput is being constrained by
7954 * something other than the maximum window size anyway.
7956 if (newwin == c->v.v2.locmaxwin &&
7957 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7958 up = snew(unsigned);
7959 *up = newwin - c->v.v2.locwindow;
7960 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7961 ssh2_handle_winadj_response, up);
7962 ssh2_pkt_send(ssh, pktout);
7964 if (c->v.v2.throttle_state != UNTHROTTLED)
7965 c->v.v2.throttle_state = UNTHROTTLING;
7967 /* Pretend the WINDOW_ADJUST was acked immediately. */
7968 c->v.v2.remlocwin = newwin;
7969 c->v.v2.throttle_state = THROTTLED;
7971 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7972 ssh2_pkt_adduint32(pktout, c->remoteid);
7973 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7974 ssh2_pkt_send(ssh, pktout);
7975 c->v.v2.locwindow = newwin;
7980 * Find the channel associated with a message. If there's no channel,
7981 * or it's not properly open, make a noise about it and return NULL.
7983 static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin)
7985 unsigned localid = ssh_pkt_getuint32(pktin);
7986 struct ssh_channel *c;
7989 /* Is this message OK on a half-open connection? */
7990 if (ssh->version == 1)
7991 halfopen_ok = (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION ||
7992 pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE);
7994 halfopen_ok = (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION ||
7995 pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE);
7996 c = find234(ssh->channels, &localid, ssh_channelfind);
7997 if (!c || (c->type != CHAN_SHARING && c->halfopen && !halfopen_ok)) {
7998 char *buf = dupprintf("Received %s for %s channel %u",
7999 ssh_pkt_type(ssh, pktin->type),
8000 c ? "half-open" : "nonexistent", localid);
8001 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
8008 static void ssh2_handle_winadj_response(struct ssh_channel *c,
8009 struct Packet *pktin, void *ctx)
8011 unsigned *sizep = ctx;
8014 * Winadj responses should always be failures. However, at least
8015 * one server ("boks_sshd") is known to return SUCCESS for channel
8016 * requests it's never heard of, such as "winadj@putty". Raised
8017 * with foxt.com as bug 090916-090424, but for the sake of a quiet
8018 * life, we don't worry about what kind of response we got.
8021 c->v.v2.remlocwin += *sizep;
8024 * winadj messages are only sent when the window is fully open, so
8025 * if we get an ack of one, we know any pending unthrottle is
8028 if (c->v.v2.throttle_state == UNTHROTTLING)
8029 c->v.v2.throttle_state = UNTHROTTLED;
8032 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
8034 struct ssh_channel *c = ssh_channel_msg(ssh, pktin);
8035 struct outstanding_channel_request *ocr;
8038 if (c->type == CHAN_SHARING) {
8039 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8040 pktin->body, pktin->length);
8043 ocr = c->v.v2.chanreq_head;
8045 ssh2_msg_unexpected(ssh, pktin);
8048 ocr->handler(c, pktin, ocr->ctx);
8049 c->v.v2.chanreq_head = ocr->next;
8052 * We may now initiate channel-closing procedures, if that
8053 * CHANNEL_REQUEST was the last thing outstanding before we send
8056 ssh2_channel_check_close(c);
8059 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
8061 struct ssh_channel *c;
8062 c = ssh_channel_msg(ssh, pktin);
8065 if (c->type == CHAN_SHARING) {
8066 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8067 pktin->body, pktin->length);
8070 if (!(c->closes & CLOSES_SENT_EOF)) {
8071 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
8072 ssh2_try_send_and_unthrottle(ssh, c);
8076 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
8080 struct ssh_channel *c;
8081 c = ssh_channel_msg(ssh, pktin);
8084 if (c->type == CHAN_SHARING) {
8085 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8086 pktin->body, pktin->length);
8089 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
8090 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
8091 return; /* extended but not stderr */
8092 ssh_pkt_getstring(pktin, &data, &length);
8095 c->v.v2.locwindow -= length;
8096 c->v.v2.remlocwin -= length;
8097 bufsize = ssh_channel_data(c, pktin->type ==
8098 SSH2_MSG_CHANNEL_EXTENDED_DATA,
8101 * If it looks like the remote end hit the end of its window,
8102 * and we didn't want it to do that, think about using a
8105 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
8106 c->v.v2.locmaxwin < 0x40000000)
8107 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
8109 * If we are not buffering too much data,
8110 * enlarge the window again at the remote side.
8111 * If we are buffering too much, we may still
8112 * need to adjust the window if the server's
8115 if (bufsize < c->v.v2.locmaxwin)
8116 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
8118 * If we're either buffering way too much data, or if we're
8119 * buffering anything at all and we're in "simple" mode,
8120 * throttle the whole channel.
8122 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
8123 && !c->throttling_conn) {
8124 c->throttling_conn = 1;
8125 ssh_throttle_conn(ssh, +1);
8130 static void ssh_check_termination(Ssh ssh)
8132 if (ssh->version == 2 &&
8133 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
8134 (ssh->channels && count234(ssh->channels) == 0) &&
8135 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
8137 * We used to send SSH_MSG_DISCONNECT here, because I'd
8138 * believed that _every_ conforming SSH-2 connection had to
8139 * end with a disconnect being sent by at least one side;
8140 * apparently I was wrong and it's perfectly OK to
8141 * unceremoniously slam the connection shut when you're done,
8142 * and indeed OpenSSH feels this is more polite than sending a
8143 * DISCONNECT. So now we don't.
8145 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8149 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8150 const char *peerinfo)
8153 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8156 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8159 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8161 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8162 ssh_check_termination(ssh);
8165 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8170 va_start(ap, logfmt);
8171 buf = dupvprintf(logfmt, ap);
8174 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8176 logeventf(ssh, "Connection sharing: %s", buf);
8180 static void ssh_channel_destroy(struct ssh_channel *c)
8185 case CHAN_MAINSESSION:
8186 ssh->mainchan = NULL;
8187 update_specials_menu(ssh->frontend);
8190 if (c->u.x11.xconn != NULL)
8191 x11_close(c->u.x11.xconn);
8192 logevent("Forwarded X11 connection terminated");
8195 sfree(c->u.a.message);
8198 if (c->u.pfd.pf != NULL)
8199 pfd_close(c->u.pfd.pf);
8200 logevent("Forwarded port closed");
8204 del234(ssh->channels, c);
8205 if (ssh->version == 2) {
8206 bufchain_clear(&c->v.v2.outbuffer);
8207 assert(c->v.v2.chanreq_head == NULL);
8212 * If that was the last channel left open, we might need to
8215 ssh_check_termination(ssh);
8218 static void ssh2_channel_check_close(struct ssh_channel *c)
8221 struct Packet *pktout;
8223 assert(ssh->version == 2);
8226 * If we've sent out our own CHANNEL_OPEN but not yet seen
8227 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8228 * it's too early to be sending close messages of any kind.
8233 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8234 c->type == CHAN_ZOMBIE) &&
8235 !c->v.v2.chanreq_head &&
8236 !(c->closes & CLOSES_SENT_CLOSE)) {
8238 * We have both sent and received EOF (or the channel is a
8239 * zombie), and we have no outstanding channel requests, which
8240 * means the channel is in final wind-up. But we haven't sent
8241 * CLOSE, so let's do so now.
8243 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8244 ssh2_pkt_adduint32(pktout, c->remoteid);
8245 ssh2_pkt_send(ssh, pktout);
8246 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8249 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8250 assert(c->v.v2.chanreq_head == NULL);
8252 * We have both sent and received CLOSE, which means we're
8253 * completely done with the channel.
8255 ssh_channel_destroy(c);
8259 static void ssh2_channel_got_eof(struct ssh_channel *c)
8261 if (c->closes & CLOSES_RCVD_EOF)
8262 return; /* already seen EOF */
8263 c->closes |= CLOSES_RCVD_EOF;
8265 if (c->type == CHAN_X11) {
8266 x11_send_eof(c->u.x11.xconn);
8267 } else if (c->type == CHAN_AGENT) {
8268 if (c->u.a.outstanding_requests == 0) {
8269 /* Manufacture an outgoing EOF in response to the incoming one. */
8270 sshfwd_write_eof(c);
8272 } else if (c->type == CHAN_SOCKDATA) {
8273 pfd_send_eof(c->u.pfd.pf);
8274 } else if (c->type == CHAN_MAINSESSION) {
8277 if (!ssh->sent_console_eof &&
8278 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8280 * Either from_backend_eof told us that the front end
8281 * wants us to close the outgoing side of the connection
8282 * as soon as we see EOF from the far end, or else we've
8283 * unilaterally decided to do that because we've allocated
8284 * a remote pty and hence EOF isn't a particularly
8285 * meaningful concept.
8287 sshfwd_write_eof(c);
8289 ssh->sent_console_eof = TRUE;
8292 ssh2_channel_check_close(c);
8295 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8297 struct ssh_channel *c;
8299 c = ssh_channel_msg(ssh, pktin);
8302 if (c->type == CHAN_SHARING) {
8303 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8304 pktin->body, pktin->length);
8307 ssh2_channel_got_eof(c);
8310 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8312 struct ssh_channel *c;
8314 c = ssh_channel_msg(ssh, pktin);
8317 if (c->type == CHAN_SHARING) {
8318 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8319 pktin->body, pktin->length);
8324 * When we receive CLOSE on a channel, we assume it comes with an
8325 * implied EOF if we haven't seen EOF yet.
8327 ssh2_channel_got_eof(c);
8329 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8331 * It also means we stop expecting to see replies to any
8332 * outstanding channel requests, so clean those up too.
8333 * (ssh_chanreq_init will enforce by assertion that we don't
8334 * subsequently put anything back on this list.)
8336 while (c->v.v2.chanreq_head) {
8337 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8338 ocr->handler(c, NULL, ocr->ctx);
8339 c->v.v2.chanreq_head = ocr->next;
8345 * And we also send an outgoing EOF, if we haven't already, on the
8346 * assumption that CLOSE is a pretty forceful announcement that
8347 * the remote side is doing away with the entire channel. (If it
8348 * had wanted to send us EOF and continue receiving data from us,
8349 * it would have just sent CHANNEL_EOF.)
8351 if (!(c->closes & CLOSES_SENT_EOF)) {
8353 * Make sure we don't read any more from whatever our local
8354 * data source is for this channel.
8357 case CHAN_MAINSESSION:
8358 ssh->send_ok = 0; /* stop trying to read from stdin */
8361 x11_override_throttle(c->u.x11.xconn, 1);
8364 pfd_override_throttle(c->u.pfd.pf, 1);
8369 * Abandon any buffered data we still wanted to send to this
8370 * channel. Receiving a CHANNEL_CLOSE is an indication that
8371 * the server really wants to get on and _destroy_ this
8372 * channel, and it isn't going to send us any further
8373 * WINDOW_ADJUSTs to permit us to send pending stuff.
8375 bufchain_clear(&c->v.v2.outbuffer);
8378 * Send outgoing EOF.
8380 sshfwd_write_eof(c);
8384 * Now process the actual close.
8386 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8387 c->closes |= CLOSES_RCVD_CLOSE;
8388 ssh2_channel_check_close(c);
8392 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8394 struct ssh_channel *c;
8396 c = ssh_channel_msg(ssh, pktin);
8399 if (c->type == CHAN_SHARING) {
8400 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8401 pktin->body, pktin->length);
8404 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8405 c->remoteid = ssh_pkt_getuint32(pktin);
8406 c->halfopen = FALSE;
8407 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8408 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8410 if (c->type == CHAN_SOCKDATA_DORMANT) {
8411 c->type = CHAN_SOCKDATA;
8413 pfd_confirm(c->u.pfd.pf);
8414 } else if (c->type == CHAN_ZOMBIE) {
8416 * This case can occur if a local socket error occurred
8417 * between us sending out CHANNEL_OPEN and receiving
8418 * OPEN_CONFIRMATION. In this case, all we can do is
8419 * immediately initiate close proceedings now that we know the
8420 * server's id to put in the close message.
8422 ssh2_channel_check_close(c);
8425 * We never expect to receive OPEN_CONFIRMATION for any
8426 * *other* channel type (since only local-to-remote port
8427 * forwardings cause us to send CHANNEL_OPEN after the main
8428 * channel is live - all other auxiliary channel types are
8429 * initiated from the server end). It's safe to enforce this
8430 * by assertion rather than by ssh_disconnect, because the
8431 * real point is that we never constructed a half-open channel
8432 * structure in the first place with any type other than the
8435 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8439 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8442 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8444 static const char *const reasons[] = {
8445 "<unknown reason code>",
8446 "Administratively prohibited",
8448 "Unknown channel type",
8449 "Resource shortage",
8451 unsigned reason_code;
8452 char *reason_string;
8454 struct ssh_channel *c;
8456 c = ssh_channel_msg(ssh, pktin);
8459 if (c->type == CHAN_SHARING) {
8460 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8461 pktin->body, pktin->length);
8464 assert(c->halfopen); /* ssh_channel_msg will have enforced this */
8466 if (c->type == CHAN_SOCKDATA_DORMANT) {
8467 reason_code = ssh_pkt_getuint32(pktin);
8468 if (reason_code >= lenof(reasons))
8469 reason_code = 0; /* ensure reasons[reason_code] in range */
8470 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8471 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8472 reasons[reason_code], reason_length,
8473 NULLTOEMPTY(reason_string));
8475 pfd_close(c->u.pfd.pf);
8476 } else if (c->type == CHAN_ZOMBIE) {
8478 * This case can occur if a local socket error occurred
8479 * between us sending out CHANNEL_OPEN and receiving
8480 * OPEN_FAILURE. In this case, we need do nothing except allow
8481 * the code below to throw the half-open channel away.
8485 * We never expect to receive OPEN_FAILURE for any *other*
8486 * channel type (since only local-to-remote port forwardings
8487 * cause us to send CHANNEL_OPEN after the main channel is
8488 * live - all other auxiliary channel types are initiated from
8489 * the server end). It's safe to enforce this by assertion
8490 * rather than by ssh_disconnect, because the real point is
8491 * that we never constructed a half-open channel structure in
8492 * the first place with any type other than the above.
8494 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8497 del234(ssh->channels, c);
8501 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8504 int typelen, want_reply;
8505 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8506 struct ssh_channel *c;
8507 struct Packet *pktout;
8509 c = ssh_channel_msg(ssh, pktin);
8512 if (c->type == CHAN_SHARING) {
8513 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8514 pktin->body, pktin->length);
8517 ssh_pkt_getstring(pktin, &type, &typelen);
8518 want_reply = ssh2_pkt_getbool(pktin);
8520 if (c->closes & CLOSES_SENT_CLOSE) {
8522 * We don't reply to channel requests after we've sent
8523 * CHANNEL_CLOSE for the channel, because our reply might
8524 * cross in the network with the other side's CHANNEL_CLOSE
8525 * and arrive after they have wound the channel up completely.
8531 * Having got the channel number, we now look at
8532 * the request type string to see if it's something
8535 if (c == ssh->mainchan) {
8537 * We recognise "exit-status" and "exit-signal" on
8538 * the primary channel.
8540 if (typelen == 11 &&
8541 !memcmp(type, "exit-status", 11)) {
8543 ssh->exitcode = ssh_pkt_getuint32(pktin);
8544 logeventf(ssh, "Server sent command exit status %d",
8546 reply = SSH2_MSG_CHANNEL_SUCCESS;
8548 } else if (typelen == 11 &&
8549 !memcmp(type, "exit-signal", 11)) {
8551 int is_plausible = TRUE, is_int = FALSE;
8552 char *fmt_sig = NULL, *fmt_msg = NULL;
8554 int msglen = 0, core = FALSE;
8555 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8556 * provide an `int' for the signal, despite its
8557 * having been a `string' in the drafts of RFC 4254 since at
8558 * least 2001. (Fixed in session.c 1.147.) Try to
8559 * infer which we can safely parse it as. */
8561 unsigned char *p = pktin->body +
8563 long len = pktin->length - pktin->savedpos;
8564 unsigned long num = GET_32BIT(p); /* what is it? */
8565 /* If it's 0, it hardly matters; assume string */
8569 int maybe_int = FALSE, maybe_str = FALSE;
8570 #define CHECK_HYPOTHESIS(offset, result) \
8573 int q = toint(offset); \
8574 if (q >= 0 && q+4 <= len) { \
8575 q = toint(q + 4 + GET_32BIT(p+q)); \
8576 if (q >= 0 && q+4 <= len && \
8577 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8582 CHECK_HYPOTHESIS(4+1, maybe_int);
8583 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8584 #undef CHECK_HYPOTHESIS
8585 if (maybe_int && !maybe_str)
8587 else if (!maybe_int && maybe_str)
8590 /* Crikey. Either or neither. Panic. */
8591 is_plausible = FALSE;
8594 ssh->exitcode = 128; /* means `unknown signal' */
8597 /* Old non-standard OpenSSH. */
8598 int signum = ssh_pkt_getuint32(pktin);
8599 fmt_sig = dupprintf(" %d", signum);
8600 ssh->exitcode = 128 + signum;
8602 /* As per RFC 4254. */
8605 ssh_pkt_getstring(pktin, &sig, &siglen);
8606 /* Signal name isn't supposed to be blank, but
8607 * let's cope gracefully if it is. */
8609 fmt_sig = dupprintf(" \"%.*s\"",
8614 * Really hideous method of translating the
8615 * signal description back into a locally
8616 * meaningful number.
8621 #define TRANSLATE_SIGNAL(s) \
8622 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8623 ssh->exitcode = 128 + SIG ## s
8625 TRANSLATE_SIGNAL(ABRT);
8628 TRANSLATE_SIGNAL(ALRM);
8631 TRANSLATE_SIGNAL(FPE);
8634 TRANSLATE_SIGNAL(HUP);
8637 TRANSLATE_SIGNAL(ILL);
8640 TRANSLATE_SIGNAL(INT);
8643 TRANSLATE_SIGNAL(KILL);
8646 TRANSLATE_SIGNAL(PIPE);
8649 TRANSLATE_SIGNAL(QUIT);
8652 TRANSLATE_SIGNAL(SEGV);
8655 TRANSLATE_SIGNAL(TERM);
8658 TRANSLATE_SIGNAL(USR1);
8661 TRANSLATE_SIGNAL(USR2);
8663 #undef TRANSLATE_SIGNAL
8665 ssh->exitcode = 128;
8667 core = ssh2_pkt_getbool(pktin);
8668 ssh_pkt_getstring(pktin, &msg, &msglen);
8670 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8672 /* ignore lang tag */
8673 } /* else don't attempt to parse */
8674 logeventf(ssh, "Server exited on signal%s%s%s",
8675 fmt_sig ? fmt_sig : "",
8676 core ? " (core dumped)" : "",
8677 fmt_msg ? fmt_msg : "");
8680 reply = SSH2_MSG_CHANNEL_SUCCESS;
8685 * This is a channel request we don't know
8686 * about, so we now either ignore the request
8687 * or respond with CHANNEL_FAILURE, depending
8690 reply = SSH2_MSG_CHANNEL_FAILURE;
8693 pktout = ssh2_pkt_init(reply);
8694 ssh2_pkt_adduint32(pktout, c->remoteid);
8695 ssh2_pkt_send(ssh, pktout);
8699 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8702 int typelen, want_reply;
8703 struct Packet *pktout;
8705 ssh_pkt_getstring(pktin, &type, &typelen);
8706 want_reply = ssh2_pkt_getbool(pktin);
8709 * We currently don't support any global requests
8710 * at all, so we either ignore the request or
8711 * respond with REQUEST_FAILURE, depending on
8715 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8716 ssh2_pkt_send(ssh, pktout);
8720 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8724 struct X11FakeAuth *auth;
8727 * Make up a new set of fake X11 auth data, and add it to the tree
8728 * of currently valid ones with an indication of the sharing
8729 * context that it's relevant to.
8731 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8732 auth->share_cs = share_cs;
8733 auth->share_chan = share_chan;
8738 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8740 del234(ssh->x11authtree, auth);
8741 x11_free_fake_auth(auth);
8744 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8751 const char *error = NULL;
8752 struct ssh_channel *c;
8753 unsigned remid, winsize, pktsize;
8754 unsigned our_winsize_override = 0;
8755 struct Packet *pktout;
8757 ssh_pkt_getstring(pktin, &type, &typelen);
8758 c = snew(struct ssh_channel);
8761 remid = ssh_pkt_getuint32(pktin);
8762 winsize = ssh_pkt_getuint32(pktin);
8763 pktsize = ssh_pkt_getuint32(pktin);
8765 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8768 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8769 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8770 peerport = ssh_pkt_getuint32(pktin);
8772 logeventf(ssh, "Received X11 connect request from %s:%d",
8775 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8776 error = "X11 forwarding is not enabled";
8778 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8781 c->u.x11.initial = TRUE;
8784 * If we are a connection-sharing upstream, then we should
8785 * initially present a very small window, adequate to take
8786 * the X11 initial authorisation packet but not much more.
8787 * Downstream will then present us a larger window (by
8788 * fiat of the connection-sharing protocol) and we can
8789 * guarantee to send a positive-valued WINDOW_ADJUST.
8792 our_winsize_override = 128;
8794 logevent("Opened X11 forward channel");
8798 } else if (typelen == 15 &&
8799 !memcmp(type, "forwarded-tcpip", 15)) {
8800 struct ssh_rportfwd pf, *realpf;
8803 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8804 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8805 pf.sport = ssh_pkt_getuint32(pktin);
8806 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8807 peerport = ssh_pkt_getuint32(pktin);
8808 realpf = find234(ssh->rportfwds, &pf, NULL);
8809 logeventf(ssh, "Received remote port %s:%d open request "
8810 "from %.*s:%d", pf.shost, pf.sport,
8811 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8814 if (realpf == NULL) {
8815 error = "Remote port is not recognised";
8819 if (realpf->share_ctx) {
8821 * This port forwarding is on behalf of a
8822 * connection-sharing downstream, so abandon our own
8823 * channel-open procedure and just pass the message on
8826 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8827 pktin->body, pktin->length);
8832 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8833 c, ssh->conf, realpf->pfrec->addressfamily);
8834 logeventf(ssh, "Attempting to forward remote port to "
8835 "%s:%d", realpf->dhost, realpf->dport);
8837 logeventf(ssh, "Port open failed: %s", err);
8839 error = "Port open failed";
8841 logevent("Forwarded port opened successfully");
8842 c->type = CHAN_SOCKDATA;
8845 } else if (typelen == 22 &&
8846 !memcmp(type, "auth-agent@openssh.com", 22)) {
8847 if (!ssh->agentfwd_enabled)
8848 error = "Agent forwarding is not enabled";
8850 c->type = CHAN_AGENT; /* identify channel type */
8851 c->u.a.lensofar = 0;
8852 c->u.a.message = NULL;
8853 c->u.a.outstanding_requests = 0;
8856 error = "Unsupported channel type requested";
8859 c->remoteid = remid;
8860 c->halfopen = FALSE;
8862 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8863 ssh2_pkt_adduint32(pktout, c->remoteid);
8864 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8865 ssh2_pkt_addstring(pktout, error);
8866 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8867 ssh2_pkt_send(ssh, pktout);
8868 logeventf(ssh, "Rejected channel open: %s", error);
8871 ssh_channel_init(c);
8872 c->v.v2.remwindow = winsize;
8873 c->v.v2.remmaxpkt = pktsize;
8874 if (our_winsize_override) {
8875 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8876 our_winsize_override;
8878 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8879 ssh2_pkt_adduint32(pktout, c->remoteid);
8880 ssh2_pkt_adduint32(pktout, c->localid);
8881 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8882 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8883 ssh2_pkt_send(ssh, pktout);
8887 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8888 void *share_cs, void *share_chan,
8889 const char *peer_addr, int peer_port,
8890 int endian, int protomajor, int protominor,
8891 const void *initial_data, int initial_len)
8894 * This function is called when we've just discovered that an X
8895 * forwarding channel on which we'd been handling the initial auth
8896 * ourselves turns out to be destined for a connection-sharing
8897 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8898 * that we completely stop tracking windows and buffering data and
8899 * just pass more or less unmodified SSH messages back and forth.
8901 c->type = CHAN_SHARING;
8902 c->u.sharing.ctx = share_cs;
8903 share_setup_x11_channel(share_cs, share_chan,
8904 c->localid, c->remoteid, c->v.v2.remwindow,
8905 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8906 peer_addr, peer_port, endian,
8907 protomajor, protominor,
8908 initial_data, initial_len);
8911 void sshfwd_x11_is_local(struct ssh_channel *c)
8914 * This function is called when we've just discovered that an X
8915 * forwarding channel is _not_ destined for a connection-sharing
8916 * downstream but we're going to handle it ourselves. We stop
8917 * presenting a cautiously small window and go into ordinary data
8920 c->u.x11.initial = FALSE;
8921 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8925 * Buffer banner messages for later display at some convenient point,
8926 * if we're going to display them.
8928 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8930 /* Arbitrary limit to prevent unbounded inflation of buffer */
8931 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8932 bufchain_size(&ssh->banner) <= 131072) {
8933 char *banner = NULL;
8935 ssh_pkt_getstring(pktin, &banner, &size);
8937 bufchain_add(&ssh->banner, banner, size);
8941 /* Helper function to deal with sending tty modes for "pty-req" */
8942 static void ssh2_send_ttymode(void *data,
8943 const struct ssh_ttymode *mode, char *val)
8945 struct Packet *pktout = (struct Packet *)data;
8946 unsigned int arg = 0;
8948 switch (mode->type) {
8950 arg = ssh_tty_parse_specchar(val);
8953 arg = ssh_tty_parse_boolean(val);
8956 ssh2_pkt_addbyte(pktout, mode->opcode);
8957 ssh2_pkt_adduint32(pktout, arg);
8960 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8963 struct ssh2_setup_x11_state {
8967 struct Packet *pktout;
8968 crStateP(ssh2_setup_x11_state, ctx);
8972 logevent("Requesting X11 forwarding");
8973 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8975 ssh2_pkt_addbool(pktout, 0); /* many connections */
8976 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8977 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8978 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8979 ssh2_pkt_send(ssh, pktout);
8981 /* Wait to be called back with either a response packet, or NULL
8982 * meaning clean up and free our data */
8986 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8987 logevent("X11 forwarding enabled");
8988 ssh->X11_fwd_enabled = TRUE;
8990 logevent("X11 forwarding refused");
8996 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8999 struct ssh2_setup_agent_state {
9003 struct Packet *pktout;
9004 crStateP(ssh2_setup_agent_state, ctx);
9008 logevent("Requesting OpenSSH-style agent forwarding");
9009 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
9010 ssh2_setup_agent, s);
9011 ssh2_pkt_send(ssh, pktout);
9013 /* Wait to be called back with either a response packet, or NULL
9014 * meaning clean up and free our data */
9018 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9019 logevent("Agent forwarding enabled");
9020 ssh->agentfwd_enabled = TRUE;
9022 logevent("Agent forwarding refused");
9028 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
9031 struct ssh2_setup_pty_state {
9035 struct Packet *pktout;
9036 crStateP(ssh2_setup_pty_state, ctx);
9040 /* Unpick the terminal-speed string. */
9041 /* XXX perhaps we should allow no speeds to be sent. */
9042 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
9043 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
9044 /* Build the pty request. */
9045 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
9047 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
9048 ssh2_pkt_adduint32(pktout, ssh->term_width);
9049 ssh2_pkt_adduint32(pktout, ssh->term_height);
9050 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
9051 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
9052 ssh2_pkt_addstring_start(pktout);
9053 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
9054 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
9055 ssh2_pkt_adduint32(pktout, ssh->ispeed);
9056 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
9057 ssh2_pkt_adduint32(pktout, ssh->ospeed);
9058 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
9059 ssh2_pkt_send(ssh, pktout);
9060 ssh->state = SSH_STATE_INTERMED;
9062 /* Wait to be called back with either a response packet, or NULL
9063 * meaning clean up and free our data */
9067 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
9068 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9069 ssh->ospeed, ssh->ispeed);
9070 ssh->got_pty = TRUE;
9072 c_write_str(ssh, "Server refused to allocate pty\r\n");
9073 ssh->editing = ssh->echoing = 1;
9080 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
9083 struct ssh2_setup_env_state {
9085 int num_env, env_left, env_ok;
9088 struct Packet *pktout;
9089 crStateP(ssh2_setup_env_state, ctx);
9094 * Send environment variables.
9096 * Simplest thing here is to send all the requests at once, and
9097 * then wait for a whole bunch of successes or failures.
9103 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9105 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
9106 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
9107 ssh2_pkt_addstring(pktout, key);
9108 ssh2_pkt_addstring(pktout, val);
9109 ssh2_pkt_send(ssh, pktout);
9114 logeventf(ssh, "Sent %d environment variables", s->num_env);
9119 s->env_left = s->num_env;
9121 while (s->env_left > 0) {
9122 /* Wait to be called back with either a response packet,
9123 * or NULL meaning clean up and free our data */
9125 if (!pktin) goto out;
9126 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
9131 if (s->env_ok == s->num_env) {
9132 logevent("All environment variables successfully set");
9133 } else if (s->env_ok == 0) {
9134 logevent("All environment variables refused");
9135 c_write_str(ssh, "Server refused to set environment variables\r\n");
9137 logeventf(ssh, "%d environment variables refused",
9138 s->num_env - s->env_ok);
9139 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9147 * Handle the SSH-2 userauth and connection layers.
9149 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9151 do_ssh2_authconn(ssh, NULL, 0, pktin);
9154 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9158 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9161 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9162 struct Packet *pktin)
9164 struct do_ssh2_authconn_state {
9168 AUTH_TYPE_PUBLICKEY,
9169 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9170 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9172 AUTH_TYPE_GSSAPI, /* always QUIET */
9173 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9174 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9176 int done_service_req;
9177 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9178 int tried_pubkey_config, done_agent;
9183 int kbd_inter_refused;
9184 int we_are_in, userauth_success;
9185 prompts_t *cur_prompt;
9190 void *publickey_blob;
9191 int publickey_bloblen;
9192 int privatekey_available, privatekey_encrypted;
9193 char *publickey_algorithm;
9194 char *publickey_comment;
9195 unsigned char agent_request[5], *agent_response, *agentp;
9196 int agent_responselen;
9197 unsigned char *pkblob_in_agent;
9199 char *pkblob, *alg, *commentp;
9200 int pklen, alglen, commentlen;
9201 int siglen, retlen, len;
9202 char *q, *agentreq, *ret;
9203 struct Packet *pktout;
9206 struct ssh_gss_library *gsslib;
9207 Ssh_gss_ctx gss_ctx;
9208 Ssh_gss_buf gss_buf;
9209 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9210 Ssh_gss_name gss_srv_name;
9211 Ssh_gss_stat gss_stat;
9214 crState(do_ssh2_authconn_state);
9218 /* Register as a handler for all the messages this coroutine handles. */
9219 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9220 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9221 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9222 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9223 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9224 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9225 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9226 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9227 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9228 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9229 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9230 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9231 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9232 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9233 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9234 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9235 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9236 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9237 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9238 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9240 s->done_service_req = FALSE;
9241 s->we_are_in = s->userauth_success = FALSE;
9242 s->agent_response = NULL;
9244 s->tried_gssapi = FALSE;
9247 if (!ssh->bare_connection) {
9248 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9250 * Request userauth protocol, and await a response to it.
9252 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9253 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9254 ssh2_pkt_send(ssh, s->pktout);
9255 crWaitUntilV(pktin);
9256 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9257 s->done_service_req = TRUE;
9259 if (!s->done_service_req) {
9261 * Request connection protocol directly, without authentication.
9263 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9264 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9265 ssh2_pkt_send(ssh, s->pktout);
9266 crWaitUntilV(pktin);
9267 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9268 s->we_are_in = TRUE; /* no auth required */
9270 bombout(("Server refused service request"));
9275 s->we_are_in = TRUE;
9278 /* Arrange to be able to deal with any BANNERs that come in.
9279 * (We do this now as packets may come in during the next bit.) */
9280 bufchain_init(&ssh->banner);
9281 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9282 ssh2_msg_userauth_banner;
9285 * Misc one-time setup for authentication.
9287 s->publickey_blob = NULL;
9288 if (!s->we_are_in) {
9291 * Load the public half of any configured public key file
9294 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9295 if (!filename_is_null(s->keyfile)) {
9297 logeventf(ssh, "Reading key file \"%.150s\"",
9298 filename_to_str(s->keyfile));
9299 keytype = key_type(s->keyfile);
9300 if (keytype == SSH_KEYTYPE_SSH2 ||
9301 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9302 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9305 ssh2_userkey_loadpub(s->keyfile,
9306 &s->publickey_algorithm,
9307 &s->publickey_bloblen,
9308 &s->publickey_comment, &error);
9309 if (s->publickey_blob) {
9310 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9311 if (!s->privatekey_available)
9312 logeventf(ssh, "Key file contains public key only");
9313 s->privatekey_encrypted =
9314 ssh2_userkey_encrypted(s->keyfile, NULL);
9317 logeventf(ssh, "Unable to load key (%s)",
9319 msgbuf = dupprintf("Unable to load key file "
9320 "\"%.150s\" (%s)\r\n",
9321 filename_to_str(s->keyfile),
9323 c_write_str(ssh, msgbuf);
9328 logeventf(ssh, "Unable to use this key file (%s)",
9329 key_type_to_str(keytype));
9330 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9332 filename_to_str(s->keyfile),
9333 key_type_to_str(keytype));
9334 c_write_str(ssh, msgbuf);
9336 s->publickey_blob = NULL;
9341 * Find out about any keys Pageant has (but if there's a
9342 * public key configured, filter out all others).
9345 s->agent_response = NULL;
9346 s->pkblob_in_agent = NULL;
9347 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9351 logevent("Pageant is running. Requesting keys.");
9353 /* Request the keys held by the agent. */
9354 PUT_32BIT(s->agent_request, 1);
9355 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9356 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9357 ssh_agent_callback, ssh)) {
9361 bombout(("Unexpected data from server while"
9362 " waiting for agent response"));
9365 } while (pktin || inlen > 0);
9366 r = ssh->agent_response;
9367 s->agent_responselen = ssh->agent_response_len;
9369 s->agent_response = (unsigned char *) r;
9370 if (s->agent_response && s->agent_responselen >= 5 &&
9371 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9374 p = s->agent_response + 5;
9375 s->nkeys = toint(GET_32BIT(p));
9378 * Vet the Pageant response to ensure that the key
9379 * count and blob lengths make sense.
9382 logeventf(ssh, "Pageant response contained a negative"
9383 " key count %d", s->nkeys);
9385 goto done_agent_query;
9387 unsigned char *q = p + 4;
9388 int lenleft = s->agent_responselen - 5 - 4;
9390 for (keyi = 0; keyi < s->nkeys; keyi++) {
9391 int bloblen, commentlen;
9393 logeventf(ssh, "Pageant response was truncated");
9395 goto done_agent_query;
9397 bloblen = toint(GET_32BIT(q));
9398 if (bloblen < 0 || bloblen > lenleft) {
9399 logeventf(ssh, "Pageant response was truncated");
9401 goto done_agent_query;
9403 lenleft -= 4 + bloblen;
9405 commentlen = toint(GET_32BIT(q));
9406 if (commentlen < 0 || commentlen > lenleft) {
9407 logeventf(ssh, "Pageant response was truncated");
9409 goto done_agent_query;
9411 lenleft -= 4 + commentlen;
9412 q += 4 + commentlen;
9417 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9418 if (s->publickey_blob) {
9419 /* See if configured key is in agent. */
9420 for (keyi = 0; keyi < s->nkeys; keyi++) {
9421 s->pklen = toint(GET_32BIT(p));
9422 if (s->pklen == s->publickey_bloblen &&
9423 !memcmp(p+4, s->publickey_blob,
9424 s->publickey_bloblen)) {
9425 logeventf(ssh, "Pageant key #%d matches "
9426 "configured key file", keyi);
9428 s->pkblob_in_agent = p;
9432 p += toint(GET_32BIT(p)) + 4; /* comment */
9434 if (!s->pkblob_in_agent) {
9435 logevent("Configured key file not in Pageant");
9440 logevent("Failed to get reply from Pageant");
9448 * We repeat this whole loop, including the username prompt,
9449 * until we manage a successful authentication. If the user
9450 * types the wrong _password_, they can be sent back to the
9451 * beginning to try another username, if this is configured on.
9452 * (If they specify a username in the config, they are never
9453 * asked, even if they do give a wrong password.)
9455 * I think this best serves the needs of
9457 * - the people who have no configuration, no keys, and just
9458 * want to try repeated (username,password) pairs until they
9459 * type both correctly
9461 * - people who have keys and configuration but occasionally
9462 * need to fall back to passwords
9464 * - people with a key held in Pageant, who might not have
9465 * logged in to a particular machine before; so they want to
9466 * type a username, and then _either_ their key will be
9467 * accepted, _or_ they will type a password. If they mistype
9468 * the username they will want to be able to get back and
9471 s->got_username = FALSE;
9472 while (!s->we_are_in) {
9476 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9478 * We got a username last time round this loop, and
9479 * with change_username turned off we don't try to get
9482 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9483 int ret; /* need not be kept over crReturn */
9484 s->cur_prompt = new_prompts(ssh->frontend);
9485 s->cur_prompt->to_server = TRUE;
9486 s->cur_prompt->name = dupstr("SSH login name");
9487 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9488 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9491 crWaitUntilV(!pktin);
9492 ret = get_userpass_input(s->cur_prompt, in, inlen);
9497 * get_userpass_input() failed to get a username.
9500 free_prompts(s->cur_prompt);
9501 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9504 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9505 free_prompts(s->cur_prompt);
9508 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9509 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9510 c_write_str(ssh, stuff);
9514 s->got_username = TRUE;
9517 * Send an authentication request using method "none": (a)
9518 * just in case it succeeds, and (b) so that we know what
9519 * authentication methods we can usefully try next.
9521 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9523 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9524 ssh2_pkt_addstring(s->pktout, ssh->username);
9525 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9526 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9527 ssh2_pkt_send(ssh, s->pktout);
9528 s->type = AUTH_TYPE_NONE;
9530 s->we_are_in = FALSE;
9532 s->tried_pubkey_config = FALSE;
9533 s->kbd_inter_refused = FALSE;
9535 /* Reset agent request state. */
9536 s->done_agent = FALSE;
9537 if (s->agent_response) {
9538 if (s->pkblob_in_agent) {
9539 s->agentp = s->pkblob_in_agent;
9541 s->agentp = s->agent_response + 5 + 4;
9547 char *methods = NULL;
9551 * Wait for the result of the last authentication request.
9554 crWaitUntilV(pktin);
9556 * Now is a convenient point to spew any banner material
9557 * that we've accumulated. (This should ensure that when
9558 * we exit the auth loop, we haven't any left to deal
9562 int size = bufchain_size(&ssh->banner);
9564 * Don't show the banner if we're operating in
9565 * non-verbose non-interactive mode. (It's probably
9566 * a script, which means nobody will read the
9567 * banner _anyway_, and moreover the printing of
9568 * the banner will screw up processing on the
9569 * output of (say) plink.)
9571 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9572 char *banner = snewn(size, char);
9573 bufchain_fetch(&ssh->banner, banner, size);
9574 c_write_untrusted(ssh, banner, size);
9577 bufchain_clear(&ssh->banner);
9579 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9580 logevent("Access granted");
9581 s->we_are_in = s->userauth_success = TRUE;
9585 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9586 bombout(("Strange packet received during authentication: "
9587 "type %d", pktin->type));
9594 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9595 * we can look at the string in it and know what we can
9596 * helpfully try next.
9598 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9599 ssh_pkt_getstring(pktin, &methods, &methlen);
9600 if (!ssh2_pkt_getbool(pktin)) {
9602 * We have received an unequivocal Access
9603 * Denied. This can translate to a variety of
9604 * messages, or no message at all.
9606 * For forms of authentication which are attempted
9607 * implicitly, by which I mean without printing
9608 * anything in the window indicating that we're
9609 * trying them, we should never print 'Access
9612 * If we do print a message saying that we're
9613 * attempting some kind of authentication, it's OK
9614 * to print a followup message saying it failed -
9615 * but the message may sometimes be more specific
9616 * than simply 'Access denied'.
9618 * Additionally, if we'd just tried password
9619 * authentication, we should break out of this
9620 * whole loop so as to go back to the username
9621 * prompt (iff we're configured to allow
9622 * username change attempts).
9624 if (s->type == AUTH_TYPE_NONE) {
9626 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9627 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9628 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9629 c_write_str(ssh, "Server refused our key\r\n");
9630 logevent("Server refused our key");
9631 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9632 /* This _shouldn't_ happen except by a
9633 * protocol bug causing client and server to
9634 * disagree on what is a correct signature. */
9635 c_write_str(ssh, "Server refused public-key signature"
9636 " despite accepting key!\r\n");
9637 logevent("Server refused public-key signature"
9638 " despite accepting key!");
9639 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9640 /* quiet, so no c_write */
9641 logevent("Server refused keyboard-interactive authentication");
9642 } else if (s->type==AUTH_TYPE_GSSAPI) {
9643 /* always quiet, so no c_write */
9644 /* also, the code down in the GSSAPI block has
9645 * already logged this in the Event Log */
9646 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9647 logevent("Keyboard-interactive authentication failed");
9648 c_write_str(ssh, "Access denied\r\n");
9650 assert(s->type == AUTH_TYPE_PASSWORD);
9651 logevent("Password authentication failed");
9652 c_write_str(ssh, "Access denied\r\n");
9654 if (conf_get_int(ssh->conf, CONF_change_username)) {
9655 /* XXX perhaps we should allow
9656 * keyboard-interactive to do this too? */
9657 s->we_are_in = FALSE;
9662 c_write_str(ssh, "Further authentication required\r\n");
9663 logevent("Further authentication required");
9667 in_commasep_string("publickey", methods, methlen);
9669 in_commasep_string("password", methods, methlen);
9670 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9671 in_commasep_string("keyboard-interactive", methods, methlen);
9673 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9674 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9675 /* Try loading the GSS libraries and see if we
9678 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9679 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9681 /* No point in even bothering to try to load the
9682 * GSS libraries, if the user configuration and
9683 * server aren't both prepared to attempt GSSAPI
9684 * auth in the first place. */
9685 s->can_gssapi = FALSE;
9690 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9692 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9695 * Attempt public-key authentication using a key from Pageant.
9698 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9700 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9702 /* Unpack key from agent response */
9703 s->pklen = toint(GET_32BIT(s->agentp));
9705 s->pkblob = (char *)s->agentp;
9706 s->agentp += s->pklen;
9707 s->alglen = toint(GET_32BIT(s->pkblob));
9708 s->alg = s->pkblob + 4;
9709 s->commentlen = toint(GET_32BIT(s->agentp));
9711 s->commentp = (char *)s->agentp;
9712 s->agentp += s->commentlen;
9713 /* s->agentp now points at next key, if any */
9715 /* See if server will accept it */
9716 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9717 ssh2_pkt_addstring(s->pktout, ssh->username);
9718 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9719 /* service requested */
9720 ssh2_pkt_addstring(s->pktout, "publickey");
9722 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9723 ssh2_pkt_addstring_start(s->pktout);
9724 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9725 ssh2_pkt_addstring_start(s->pktout);
9726 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9727 ssh2_pkt_send(ssh, s->pktout);
9728 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9730 crWaitUntilV(pktin);
9731 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9733 /* Offer of key refused. */
9740 if (flags & FLAG_VERBOSE) {
9741 c_write_str(ssh, "Authenticating with "
9743 c_write(ssh, s->commentp, s->commentlen);
9744 c_write_str(ssh, "\" from agent\r\n");
9748 * Server is willing to accept the key.
9749 * Construct a SIGN_REQUEST.
9751 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9752 ssh2_pkt_addstring(s->pktout, ssh->username);
9753 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9754 /* service requested */
9755 ssh2_pkt_addstring(s->pktout, "publickey");
9757 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9758 ssh2_pkt_addstring_start(s->pktout);
9759 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9760 ssh2_pkt_addstring_start(s->pktout);
9761 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9763 /* Ask agent for signature. */
9764 s->siglen = s->pktout->length - 5 + 4 +
9765 ssh->v2_session_id_len;
9766 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9768 s->len = 1; /* message type */
9769 s->len += 4 + s->pklen; /* key blob */
9770 s->len += 4 + s->siglen; /* data to sign */
9771 s->len += 4; /* flags */
9772 s->agentreq = snewn(4 + s->len, char);
9773 PUT_32BIT(s->agentreq, s->len);
9774 s->q = s->agentreq + 4;
9775 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9776 PUT_32BIT(s->q, s->pklen);
9778 memcpy(s->q, s->pkblob, s->pklen);
9780 PUT_32BIT(s->q, s->siglen);
9782 /* Now the data to be signed... */
9783 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9784 PUT_32BIT(s->q, ssh->v2_session_id_len);
9787 memcpy(s->q, ssh->v2_session_id,
9788 ssh->v2_session_id_len);
9789 s->q += ssh->v2_session_id_len;
9790 memcpy(s->q, s->pktout->data + 5,
9791 s->pktout->length - 5);
9792 s->q += s->pktout->length - 5;
9793 /* And finally the (zero) flags word. */
9795 if (!agent_query(s->agentreq, s->len + 4,
9797 ssh_agent_callback, ssh)) {
9801 bombout(("Unexpected data from server"
9802 " while waiting for agent"
9806 } while (pktin || inlen > 0);
9807 vret = ssh->agent_response;
9808 s->retlen = ssh->agent_response_len;
9813 if (s->retlen >= 9 &&
9814 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9815 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9816 logevent("Sending Pageant's response");
9817 ssh2_add_sigblob(ssh, s->pktout,
9818 s->pkblob, s->pklen,
9820 GET_32BIT(s->ret + 5));
9821 ssh2_pkt_send(ssh, s->pktout);
9822 s->type = AUTH_TYPE_PUBLICKEY;
9824 /* FIXME: less drastic response */
9825 bombout(("Pageant failed to answer challenge"));
9831 /* Do we have any keys left to try? */
9832 if (s->pkblob_in_agent) {
9833 s->done_agent = TRUE;
9834 s->tried_pubkey_config = TRUE;
9837 if (s->keyi >= s->nkeys)
9838 s->done_agent = TRUE;
9841 } else if (s->can_pubkey && s->publickey_blob &&
9842 s->privatekey_available && !s->tried_pubkey_config) {
9844 struct ssh2_userkey *key; /* not live over crReturn */
9845 char *passphrase; /* not live over crReturn */
9847 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9849 s->tried_pubkey_config = TRUE;
9852 * Try the public key supplied in the configuration.
9854 * First, offer the public blob to see if the server is
9855 * willing to accept it.
9857 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9858 ssh2_pkt_addstring(s->pktout, ssh->username);
9859 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9860 /* service requested */
9861 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9862 ssh2_pkt_addbool(s->pktout, FALSE);
9863 /* no signature included */
9864 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9865 ssh2_pkt_addstring_start(s->pktout);
9866 ssh2_pkt_addstring_data(s->pktout,
9867 (char *)s->publickey_blob,
9868 s->publickey_bloblen);
9869 ssh2_pkt_send(ssh, s->pktout);
9870 logevent("Offered public key");
9872 crWaitUntilV(pktin);
9873 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9874 /* Key refused. Give up. */
9875 s->gotit = TRUE; /* reconsider message next loop */
9876 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9877 continue; /* process this new message */
9879 logevent("Offer of public key accepted");
9882 * Actually attempt a serious authentication using
9885 if (flags & FLAG_VERBOSE) {
9886 c_write_str(ssh, "Authenticating with public key \"");
9887 c_write_str(ssh, s->publickey_comment);
9888 c_write_str(ssh, "\"\r\n");
9892 const char *error; /* not live over crReturn */
9893 if (s->privatekey_encrypted) {
9895 * Get a passphrase from the user.
9897 int ret; /* need not be kept over crReturn */
9898 s->cur_prompt = new_prompts(ssh->frontend);
9899 s->cur_prompt->to_server = FALSE;
9900 s->cur_prompt->name = dupstr("SSH key passphrase");
9901 add_prompt(s->cur_prompt,
9902 dupprintf("Passphrase for key \"%.100s\": ",
9903 s->publickey_comment),
9905 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9908 crWaitUntilV(!pktin);
9909 ret = get_userpass_input(s->cur_prompt,
9914 /* Failed to get a passphrase. Terminate. */
9915 free_prompts(s->cur_prompt);
9916 ssh_disconnect(ssh, NULL,
9917 "Unable to authenticate",
9918 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9923 dupstr(s->cur_prompt->prompts[0]->result);
9924 free_prompts(s->cur_prompt);
9926 passphrase = NULL; /* no passphrase needed */
9930 * Try decrypting the key.
9932 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9933 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9935 /* burn the evidence */
9936 smemclr(passphrase, strlen(passphrase));
9939 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9941 (key == SSH2_WRONG_PASSPHRASE)) {
9942 c_write_str(ssh, "Wrong passphrase\r\n");
9944 /* and loop again */
9946 c_write_str(ssh, "Unable to load private key (");
9947 c_write_str(ssh, error);
9948 c_write_str(ssh, ")\r\n");
9950 break; /* try something else */
9956 unsigned char *pkblob, *sigblob, *sigdata;
9957 int pkblob_len, sigblob_len, sigdata_len;
9961 * We have loaded the private key and the server
9962 * has announced that it's willing to accept it.
9963 * Hallelujah. Generate a signature and send it.
9965 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9966 ssh2_pkt_addstring(s->pktout, ssh->username);
9967 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9968 /* service requested */
9969 ssh2_pkt_addstring(s->pktout, "publickey");
9971 ssh2_pkt_addbool(s->pktout, TRUE);
9972 /* signature follows */
9973 ssh2_pkt_addstring(s->pktout, key->alg->name);
9974 pkblob = key->alg->public_blob(key->data,
9976 ssh2_pkt_addstring_start(s->pktout);
9977 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9981 * The data to be signed is:
9985 * followed by everything so far placed in the
9988 sigdata_len = s->pktout->length - 5 + 4 +
9989 ssh->v2_session_id_len;
9990 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9992 sigdata = snewn(sigdata_len, unsigned char);
9994 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9995 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9998 memcpy(sigdata+p, ssh->v2_session_id,
9999 ssh->v2_session_id_len);
10000 p += ssh->v2_session_id_len;
10001 memcpy(sigdata+p, s->pktout->data + 5,
10002 s->pktout->length - 5);
10003 p += s->pktout->length - 5;
10004 assert(p == sigdata_len);
10005 sigblob = key->alg->sign(key->data, (char *)sigdata,
10006 sigdata_len, &sigblob_len);
10007 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
10008 sigblob, sigblob_len);
10013 ssh2_pkt_send(ssh, s->pktout);
10014 logevent("Sent public key signature");
10015 s->type = AUTH_TYPE_PUBLICKEY;
10016 key->alg->freekey(key->data);
10017 sfree(key->comment);
10022 } else if (s->can_gssapi && !s->tried_gssapi) {
10024 /* GSSAPI Authentication */
10026 int micoffset, len;
10029 s->type = AUTH_TYPE_GSSAPI;
10030 s->tried_gssapi = TRUE;
10032 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
10035 * Pick the highest GSS library on the preference
10041 for (i = 0; i < ngsslibs; i++) {
10042 int want_id = conf_get_int_int(ssh->conf,
10043 CONF_ssh_gsslist, i);
10044 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
10045 if (ssh->gsslibs->libraries[j].id == want_id) {
10046 s->gsslib = &ssh->gsslibs->libraries[j];
10047 goto got_gsslib; /* double break */
10052 * We always expect to have found something in
10053 * the above loop: we only came here if there
10054 * was at least one viable GSS library, and the
10055 * preference list should always mention
10056 * everything and only change the order.
10061 if (s->gsslib->gsslogmsg)
10062 logevent(s->gsslib->gsslogmsg);
10064 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
10065 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10066 ssh2_pkt_addstring(s->pktout, ssh->username);
10067 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10068 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
10069 logevent("Attempting GSSAPI authentication");
10071 /* add mechanism info */
10072 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
10074 /* number of GSSAPI mechanisms */
10075 ssh2_pkt_adduint32(s->pktout,1);
10077 /* length of OID + 2 */
10078 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
10079 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
10081 /* length of OID */
10082 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
10084 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
10085 s->gss_buf.length);
10086 ssh2_pkt_send(ssh, s->pktout);
10087 crWaitUntilV(pktin);
10088 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
10089 logevent("GSSAPI authentication request refused");
10093 /* check returned packet ... */
10095 ssh_pkt_getstring(pktin, &data, &len);
10096 s->gss_rcvtok.value = data;
10097 s->gss_rcvtok.length = len;
10098 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
10099 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
10100 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
10101 memcmp((char *)s->gss_rcvtok.value + 2,
10102 s->gss_buf.value,s->gss_buf.length) ) {
10103 logevent("GSSAPI authentication - wrong response from server");
10107 /* now start running */
10108 s->gss_stat = s->gsslib->import_name(s->gsslib,
10111 if (s->gss_stat != SSH_GSS_OK) {
10112 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
10113 logevent("GSSAPI import name failed - Bad service name");
10115 logevent("GSSAPI import name failed");
10119 /* fetch TGT into GSS engine */
10120 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
10122 if (s->gss_stat != SSH_GSS_OK) {
10123 logevent("GSSAPI authentication failed to get credentials");
10124 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10128 /* initial tokens are empty */
10129 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
10130 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
10132 /* now enter the loop */
10134 s->gss_stat = s->gsslib->init_sec_context
10138 conf_get_int(ssh->conf, CONF_gssapifwd),
10142 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10143 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10144 logevent("GSSAPI authentication initialisation failed");
10146 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10147 &s->gss_buf) == SSH_GSS_OK) {
10148 logevent(s->gss_buf.value);
10149 sfree(s->gss_buf.value);
10154 logevent("GSSAPI authentication initialised");
10156 /* Client and server now exchange tokens until GSSAPI
10157 * no longer says CONTINUE_NEEDED */
10159 if (s->gss_sndtok.length != 0) {
10160 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10161 ssh_pkt_addstring_start(s->pktout);
10162 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10163 ssh2_pkt_send(ssh, s->pktout);
10164 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10167 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10168 crWaitUntilV(pktin);
10169 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10170 logevent("GSSAPI authentication - bad server response");
10171 s->gss_stat = SSH_GSS_FAILURE;
10174 ssh_pkt_getstring(pktin, &data, &len);
10175 s->gss_rcvtok.value = data;
10176 s->gss_rcvtok.length = len;
10178 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10180 if (s->gss_stat != SSH_GSS_OK) {
10181 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10182 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10185 logevent("GSSAPI authentication loop finished OK");
10187 /* Now send the MIC */
10189 s->pktout = ssh2_pkt_init(0);
10190 micoffset = s->pktout->length;
10191 ssh_pkt_addstring_start(s->pktout);
10192 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10193 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10194 ssh_pkt_addstring(s->pktout, ssh->username);
10195 ssh_pkt_addstring(s->pktout, "ssh-connection");
10196 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10198 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10199 s->gss_buf.length = s->pktout->length - micoffset;
10201 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10202 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10203 ssh_pkt_addstring_start(s->pktout);
10204 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10205 ssh2_pkt_send(ssh, s->pktout);
10206 s->gsslib->free_mic(s->gsslib, &mic);
10210 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10211 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10214 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10217 * Keyboard-interactive authentication.
10220 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10222 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10224 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10225 ssh2_pkt_addstring(s->pktout, ssh->username);
10226 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10227 /* service requested */
10228 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10230 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10231 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10232 ssh2_pkt_send(ssh, s->pktout);
10234 logevent("Attempting keyboard-interactive authentication");
10236 crWaitUntilV(pktin);
10237 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10238 /* Server is not willing to do keyboard-interactive
10239 * at all (or, bizarrely but legally, accepts the
10240 * user without actually issuing any prompts).
10241 * Give up on it entirely. */
10243 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10244 s->kbd_inter_refused = TRUE; /* don't try it again */
10249 * Loop while the server continues to send INFO_REQUESTs.
10251 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10253 char *name, *inst, *lang;
10254 int name_len, inst_len, lang_len;
10258 * We've got a fresh USERAUTH_INFO_REQUEST.
10259 * Get the preamble and start building a prompt.
10261 ssh_pkt_getstring(pktin, &name, &name_len);
10262 ssh_pkt_getstring(pktin, &inst, &inst_len);
10263 ssh_pkt_getstring(pktin, &lang, &lang_len);
10264 s->cur_prompt = new_prompts(ssh->frontend);
10265 s->cur_prompt->to_server = TRUE;
10268 * Get any prompt(s) from the packet.
10270 s->num_prompts = ssh_pkt_getuint32(pktin);
10271 for (i = 0; i < s->num_prompts; i++) {
10275 static char noprompt[] =
10276 "<server failed to send prompt>: ";
10278 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10279 echo = ssh2_pkt_getbool(pktin);
10282 prompt_len = lenof(noprompt)-1;
10284 add_prompt(s->cur_prompt,
10285 dupprintf("%.*s", prompt_len, prompt),
10290 /* FIXME: better prefix to distinguish from
10291 * local prompts? */
10292 s->cur_prompt->name =
10293 dupprintf("SSH server: %.*s", name_len, name);
10294 s->cur_prompt->name_reqd = TRUE;
10296 s->cur_prompt->name =
10297 dupstr("SSH server authentication");
10298 s->cur_prompt->name_reqd = FALSE;
10300 /* We add a prefix to try to make it clear that a prompt
10301 * has come from the server.
10302 * FIXME: ugly to print "Using..." in prompt _every_
10303 * time round. Can this be done more subtly? */
10304 /* Special case: for reasons best known to themselves,
10305 * some servers send k-i requests with no prompts and
10306 * nothing to display. Keep quiet in this case. */
10307 if (s->num_prompts || name_len || inst_len) {
10308 s->cur_prompt->instruction =
10309 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10310 inst_len ? "\n" : "", inst_len, inst);
10311 s->cur_prompt->instr_reqd = TRUE;
10313 s->cur_prompt->instr_reqd = FALSE;
10317 * Display any instructions, and get the user's
10321 int ret; /* not live over crReturn */
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,
10342 * Send the response(s) to the server.
10344 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10345 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10346 for (i=0; i < s->num_prompts; i++) {
10347 ssh2_pkt_addstring(s->pktout,
10348 s->cur_prompt->prompts[i]->result);
10350 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10353 * Free the prompts structure from this iteration.
10354 * If there's another, a new one will be allocated
10355 * when we return to the top of this while loop.
10357 free_prompts(s->cur_prompt);
10360 * Get the next packet in case it's another
10363 crWaitUntilV(pktin);
10368 * We should have SUCCESS or FAILURE now.
10372 } else if (s->can_passwd) {
10375 * Plain old password authentication.
10377 int ret; /* not live over crReturn */
10378 int changereq_first_time; /* not live over crReturn */
10380 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10382 s->cur_prompt = new_prompts(ssh->frontend);
10383 s->cur_prompt->to_server = TRUE;
10384 s->cur_prompt->name = dupstr("SSH password");
10385 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10390 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10393 crWaitUntilV(!pktin);
10394 ret = get_userpass_input(s->cur_prompt, in, inlen);
10399 * Failed to get responses. Terminate.
10401 free_prompts(s->cur_prompt);
10402 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10403 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10408 * Squirrel away the password. (We may need it later if
10409 * asked to change it.)
10411 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10412 free_prompts(s->cur_prompt);
10415 * Send the password packet.
10417 * We pad out the password packet to 256 bytes to make
10418 * it harder for an attacker to find the length of the
10421 * Anyone using a password longer than 256 bytes
10422 * probably doesn't have much to worry about from
10423 * people who find out how long their password is!
10425 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10426 ssh2_pkt_addstring(s->pktout, ssh->username);
10427 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10428 /* service requested */
10429 ssh2_pkt_addstring(s->pktout, "password");
10430 ssh2_pkt_addbool(s->pktout, FALSE);
10431 ssh2_pkt_addstring(s->pktout, s->password);
10432 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10433 logevent("Sent password");
10434 s->type = AUTH_TYPE_PASSWORD;
10437 * Wait for next packet, in case it's a password change
10440 crWaitUntilV(pktin);
10441 changereq_first_time = TRUE;
10443 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10446 * We're being asked for a new password
10447 * (perhaps not for the first time).
10448 * Loop until the server accepts it.
10451 int got_new = FALSE; /* not live over crReturn */
10452 char *prompt; /* not live over crReturn */
10453 int prompt_len; /* not live over crReturn */
10457 if (changereq_first_time)
10458 msg = "Server requested password change";
10460 msg = "Server rejected new password";
10462 c_write_str(ssh, msg);
10463 c_write_str(ssh, "\r\n");
10466 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10468 s->cur_prompt = new_prompts(ssh->frontend);
10469 s->cur_prompt->to_server = TRUE;
10470 s->cur_prompt->name = dupstr("New SSH password");
10471 s->cur_prompt->instruction =
10472 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10473 s->cur_prompt->instr_reqd = TRUE;
10475 * There's no explicit requirement in the protocol
10476 * for the "old" passwords in the original and
10477 * password-change messages to be the same, and
10478 * apparently some Cisco kit supports password change
10479 * by the user entering a blank password originally
10480 * and the real password subsequently, so,
10481 * reluctantly, we prompt for the old password again.
10483 * (On the other hand, some servers don't even bother
10484 * to check this field.)
10486 add_prompt(s->cur_prompt,
10487 dupstr("Current password (blank for previously entered password): "),
10489 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10491 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10495 * Loop until the user manages to enter the same
10500 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10503 crWaitUntilV(!pktin);
10504 ret = get_userpass_input(s->cur_prompt, in, inlen);
10509 * Failed to get responses. Terminate.
10511 /* burn the evidence */
10512 free_prompts(s->cur_prompt);
10513 smemclr(s->password, strlen(s->password));
10514 sfree(s->password);
10515 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10516 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10522 * If the user specified a new original password
10523 * (IYSWIM), overwrite any previously specified
10525 * (A side effect is that the user doesn't have to
10526 * re-enter it if they louse up the new password.)
10528 if (s->cur_prompt->prompts[0]->result[0]) {
10529 smemclr(s->password, strlen(s->password));
10530 /* burn the evidence */
10531 sfree(s->password);
10533 dupstr(s->cur_prompt->prompts[0]->result);
10537 * Check the two new passwords match.
10539 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10540 s->cur_prompt->prompts[2]->result)
10543 /* They don't. Silly user. */
10544 c_write_str(ssh, "Passwords do not match\r\n");
10549 * Send the new password (along with the old one).
10550 * (see above for padding rationale)
10552 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10553 ssh2_pkt_addstring(s->pktout, ssh->username);
10554 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10555 /* service requested */
10556 ssh2_pkt_addstring(s->pktout, "password");
10557 ssh2_pkt_addbool(s->pktout, TRUE);
10558 ssh2_pkt_addstring(s->pktout, s->password);
10559 ssh2_pkt_addstring(s->pktout,
10560 s->cur_prompt->prompts[1]->result);
10561 free_prompts(s->cur_prompt);
10562 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10563 logevent("Sent new password");
10566 * Now see what the server has to say about it.
10567 * (If it's CHANGEREQ again, it's not happy with the
10570 crWaitUntilV(pktin);
10571 changereq_first_time = FALSE;
10576 * We need to reexamine the current pktin at the top
10577 * of the loop. Either:
10578 * - we weren't asked to change password at all, in
10579 * which case it's a SUCCESS or FAILURE with the
10581 * - we sent a new password, and the server was
10582 * either OK with it (SUCCESS or FAILURE w/partial
10583 * success) or unhappy with the _old_ password
10584 * (FAILURE w/o partial success)
10585 * In any of these cases, we go back to the top of
10586 * the loop and start again.
10591 * We don't need the old password any more, in any
10592 * case. Burn the evidence.
10594 smemclr(s->password, strlen(s->password));
10595 sfree(s->password);
10598 char *str = dupprintf("No supported authentication methods available"
10599 " (server sent: %.*s)",
10602 ssh_disconnect(ssh, str,
10603 "No supported authentication methods available",
10604 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10614 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10616 /* Clear up various bits and pieces from authentication. */
10617 if (s->publickey_blob) {
10618 sfree(s->publickey_algorithm);
10619 sfree(s->publickey_blob);
10620 sfree(s->publickey_comment);
10622 if (s->agent_response)
10623 sfree(s->agent_response);
10625 if (s->userauth_success && !ssh->bare_connection) {
10627 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10628 * packets since. Signal the transport layer to consider enacting
10629 * delayed compression.
10631 * (Relying on we_are_in is not sufficient, as
10632 * draft-miller-secsh-compression-delayed is quite clear that it
10633 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10634 * become set for other reasons.)
10636 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10639 ssh->channels = newtree234(ssh_channelcmp);
10642 * Set up handlers for some connection protocol messages, so we
10643 * don't have to handle them repeatedly in this coroutine.
10645 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10646 ssh2_msg_channel_window_adjust;
10647 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10648 ssh2_msg_global_request;
10651 * Create the main session channel.
10653 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10654 ssh->mainchan = NULL;
10656 ssh->mainchan = snew(struct ssh_channel);
10657 ssh->mainchan->ssh = ssh;
10658 ssh_channel_init(ssh->mainchan);
10660 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10662 * Just start a direct-tcpip channel and use it as the main
10665 ssh_send_port_open(ssh->mainchan,
10666 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10667 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10669 ssh->ncmode = TRUE;
10671 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10672 logevent("Opening session as main channel");
10673 ssh2_pkt_send(ssh, s->pktout);
10674 ssh->ncmode = FALSE;
10676 crWaitUntilV(pktin);
10677 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10678 bombout(("Server refused to open channel"));
10680 /* FIXME: error data comes back in FAILURE packet */
10682 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10683 bombout(("Server's channel confirmation cited wrong channel"));
10686 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10687 ssh->mainchan->halfopen = FALSE;
10688 ssh->mainchan->type = CHAN_MAINSESSION;
10689 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10690 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10691 update_specials_menu(ssh->frontend);
10692 logevent("Opened main channel");
10696 * Now we have a channel, make dispatch table entries for
10697 * general channel-based messages.
10699 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10700 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10701 ssh2_msg_channel_data;
10702 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10703 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10704 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10705 ssh2_msg_channel_open_confirmation;
10706 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10707 ssh2_msg_channel_open_failure;
10708 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10709 ssh2_msg_channel_request;
10710 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10711 ssh2_msg_channel_open;
10712 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10713 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10716 * Now the connection protocol is properly up and running, with
10717 * all those dispatch table entries, so it's safe to let
10718 * downstreams start trying to open extra channels through us.
10720 if (ssh->connshare)
10721 share_activate(ssh->connshare, ssh->v_s);
10723 if (ssh->mainchan && ssh_is_simple(ssh)) {
10725 * This message indicates to the server that we promise
10726 * not to try to run any other channel in parallel with
10727 * this one, so it's safe for it to advertise a very large
10728 * window and leave the flow control to TCP.
10730 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10731 "simple@putty.projects.tartarus.org",
10733 ssh2_pkt_send(ssh, s->pktout);
10737 * Enable port forwardings.
10739 ssh_setup_portfwd(ssh, ssh->conf);
10741 if (ssh->mainchan && !ssh->ncmode) {
10743 * Send the CHANNEL_REQUESTS for the main session channel.
10744 * Each one is handled by its own little asynchronous
10748 /* Potentially enable X11 forwarding. */
10749 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10751 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10753 if (!ssh->x11disp) {
10754 /* FIXME: return an error message from x11_setup_display */
10755 logevent("X11 forwarding not enabled: unable to"
10756 " initialise X display");
10758 ssh->x11auth = x11_invent_fake_auth
10759 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10760 ssh->x11auth->disp = ssh->x11disp;
10762 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10766 /* Potentially enable agent forwarding. */
10767 if (ssh_agent_forwarding_permitted(ssh))
10768 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10770 /* Now allocate a pty for the session. */
10771 if (!conf_get_int(ssh->conf, CONF_nopty))
10772 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10774 /* Send environment variables. */
10775 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10778 * Start a shell or a remote command. We may have to attempt
10779 * this twice if the config data has provided a second choice
10786 if (ssh->fallback_cmd) {
10787 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10788 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10790 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10791 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10795 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10796 ssh2_response_authconn, NULL);
10797 ssh2_pkt_addstring(s->pktout, cmd);
10799 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10800 ssh2_response_authconn, NULL);
10801 ssh2_pkt_addstring(s->pktout, cmd);
10803 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10804 ssh2_response_authconn, NULL);
10806 ssh2_pkt_send(ssh, s->pktout);
10808 crWaitUntilV(pktin);
10810 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10811 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10812 bombout(("Unexpected response to shell/command request:"
10813 " packet type %d", pktin->type));
10817 * We failed to start the command. If this is the
10818 * fallback command, we really are finished; if it's
10819 * not, and if the fallback command exists, try falling
10820 * back to it before complaining.
10822 if (!ssh->fallback_cmd &&
10823 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10824 logevent("Primary command failed; attempting fallback");
10825 ssh->fallback_cmd = TRUE;
10828 bombout(("Server refused to start a shell/command"));
10831 logevent("Started a shell/command");
10836 ssh->editing = ssh->echoing = TRUE;
10839 ssh->state = SSH_STATE_SESSION;
10840 if (ssh->size_needed)
10841 ssh_size(ssh, ssh->term_width, ssh->term_height);
10842 if (ssh->eof_needed)
10843 ssh_special(ssh, TS_EOF);
10849 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10857 * _All_ the connection-layer packets we expect to
10858 * receive are now handled by the dispatch table.
10859 * Anything that reaches here must be bogus.
10862 bombout(("Strange packet received: type %d", pktin->type));
10864 } else if (ssh->mainchan) {
10866 * We have spare data. Add it to the channel buffer.
10868 ssh_send_channel_data(ssh->mainchan, (char *)in, inlen);
10876 * Handlers for SSH-2 messages that might arrive at any moment.
10878 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10880 /* log reason code in disconnect message */
10882 int reason, msglen;
10884 reason = ssh_pkt_getuint32(pktin);
10885 ssh_pkt_getstring(pktin, &msg, &msglen);
10887 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10888 buf = dupprintf("Received disconnect message (%s)",
10889 ssh2_disconnect_reasons[reason]);
10891 buf = dupprintf("Received disconnect message (unknown"
10892 " type %d)", reason);
10896 buf = dupprintf("Disconnection message text: %.*s",
10897 msglen, NULLTOEMPTY(msg));
10899 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10901 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10902 ssh2_disconnect_reasons[reason] : "unknown",
10903 msglen, NULLTOEMPTY(msg)));
10907 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10909 /* log the debug message */
10913 /* XXX maybe we should actually take notice of the return value */
10914 ssh2_pkt_getbool(pktin);
10915 ssh_pkt_getstring(pktin, &msg, &msglen);
10917 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10920 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10922 do_ssh2_transport(ssh, NULL, 0, pktin);
10926 * Called if we receive a packet that isn't allowed by the protocol.
10927 * This only applies to packets whose meaning PuTTY understands.
10928 * Entirely unknown packets are handled below.
10930 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10932 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10933 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10935 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10939 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10941 struct Packet *pktout;
10942 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10943 ssh2_pkt_adduint32(pktout, pktin->sequence);
10945 * UNIMPLEMENTED messages MUST appear in the same order as the
10946 * messages they respond to. Hence, never queue them.
10948 ssh2_pkt_send_noqueue(ssh, pktout);
10952 * Handle the top-level SSH-2 protocol.
10954 static void ssh2_protocol_setup(Ssh ssh)
10959 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10961 for (i = 0; i < 256; i++)
10962 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10965 * Initially, we only accept transport messages (and a few generic
10966 * ones). do_ssh2_authconn will add more when it starts.
10967 * Messages that are understood but not currently acceptable go to
10968 * ssh2_msg_unexpected.
10970 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10971 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10972 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10973 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10974 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10975 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10976 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10977 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10978 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10979 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10980 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10981 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10982 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10983 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10984 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10985 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10986 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10987 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10988 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10989 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10990 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10991 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10992 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10994 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10995 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10996 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10997 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10998 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10999 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11000 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11001 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11002 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11005 * These messages have a special handler from the start.
11007 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11008 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
11009 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11012 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
11017 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
11019 for (i = 0; i < 256; i++)
11020 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
11023 * Initially, we set all ssh-connection messages to 'unexpected';
11024 * do_ssh2_authconn will fill things in properly. We also handle a
11025 * couple of messages from the transport protocol which aren't
11026 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
11029 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
11030 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
11031 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
11032 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
11033 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
11034 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
11035 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
11036 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
11037 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
11038 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
11039 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
11040 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
11041 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
11042 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
11044 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
11047 * These messages have a special handler from the start.
11049 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
11050 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
11051 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
11054 static void ssh2_timer(void *ctx, unsigned long now)
11056 Ssh ssh = (Ssh)ctx;
11058 if (ssh->state == SSH_STATE_CLOSED)
11061 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11062 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
11063 now == ssh->next_rekey) {
11064 do_ssh2_transport(ssh, "timeout", -1, NULL);
11068 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
11069 struct Packet *pktin)
11071 const unsigned char *in = (const unsigned char *)vin;
11072 if (ssh->state == SSH_STATE_CLOSED)
11076 ssh->incoming_data_size += pktin->encrypted_len;
11077 if (!ssh->kex_in_progress &&
11078 ssh->max_data_size != 0 &&
11079 ssh->incoming_data_size > ssh->max_data_size)
11080 do_ssh2_transport(ssh, "too much data received", -1, NULL);
11084 ssh->packet_dispatch[pktin->type](ssh, pktin);
11085 else if (!ssh->protocol_initial_phase_done)
11086 do_ssh2_transport(ssh, in, inlen, pktin);
11088 do_ssh2_authconn(ssh, in, inlen, pktin);
11091 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
11092 struct Packet *pktin)
11094 const unsigned char *in = (const unsigned char *)vin;
11095 if (ssh->state == SSH_STATE_CLOSED)
11099 ssh->packet_dispatch[pktin->type](ssh, pktin);
11101 do_ssh2_authconn(ssh, in, inlen, pktin);
11104 static void ssh_cache_conf_values(Ssh ssh)
11106 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
11110 * Called to set up the connection.
11112 * Returns an error message, or NULL on success.
11114 static const char *ssh_init(void *frontend_handle, void **backend_handle,
11116 const char *host, int port, char **realhost,
11117 int nodelay, int keepalive)
11122 ssh = snew(struct ssh_tag);
11123 ssh->conf = conf_copy(conf);
11124 ssh_cache_conf_values(ssh);
11125 ssh->version = 0; /* when not ready yet */
11127 ssh->cipher = NULL;
11128 ssh->v1_cipher_ctx = NULL;
11129 ssh->crcda_ctx = NULL;
11130 ssh->cscipher = NULL;
11131 ssh->cs_cipher_ctx = NULL;
11132 ssh->sccipher = NULL;
11133 ssh->sc_cipher_ctx = NULL;
11135 ssh->cs_mac_ctx = NULL;
11137 ssh->sc_mac_ctx = NULL;
11138 ssh->cscomp = NULL;
11139 ssh->cs_comp_ctx = NULL;
11140 ssh->sccomp = NULL;
11141 ssh->sc_comp_ctx = NULL;
11143 ssh->kex_ctx = NULL;
11144 ssh->hostkey = NULL;
11145 ssh->hostkey_str = NULL;
11146 ssh->exitcode = -1;
11147 ssh->close_expected = FALSE;
11148 ssh->clean_exit = FALSE;
11149 ssh->state = SSH_STATE_PREPACKET;
11150 ssh->size_needed = FALSE;
11151 ssh->eof_needed = FALSE;
11153 ssh->logctx = NULL;
11154 ssh->deferred_send_data = NULL;
11155 ssh->deferred_len = 0;
11156 ssh->deferred_size = 0;
11157 ssh->fallback_cmd = 0;
11158 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11159 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11160 ssh->x11disp = NULL;
11161 ssh->x11auth = NULL;
11162 ssh->x11authtree = newtree234(x11_authcmp);
11163 ssh->v1_compressing = FALSE;
11164 ssh->v2_outgoing_sequence = 0;
11165 ssh->ssh1_rdpkt_crstate = 0;
11166 ssh->ssh2_rdpkt_crstate = 0;
11167 ssh->ssh2_bare_rdpkt_crstate = 0;
11168 ssh->ssh_gotdata_crstate = 0;
11169 ssh->do_ssh1_connection_crstate = 0;
11170 ssh->do_ssh_init_state = NULL;
11171 ssh->do_ssh_connection_init_state = NULL;
11172 ssh->do_ssh1_login_state = NULL;
11173 ssh->do_ssh2_transport_state = NULL;
11174 ssh->do_ssh2_authconn_state = NULL;
11177 ssh->mainchan = NULL;
11178 ssh->throttled_all = 0;
11179 ssh->v1_stdout_throttling = 0;
11181 ssh->queuelen = ssh->queuesize = 0;
11182 ssh->queueing = FALSE;
11183 ssh->qhead = ssh->qtail = NULL;
11184 ssh->deferred_rekey_reason = NULL;
11185 bufchain_init(&ssh->queued_incoming_data);
11186 ssh->frozen = FALSE;
11187 ssh->username = NULL;
11188 ssh->sent_console_eof = FALSE;
11189 ssh->got_pty = FALSE;
11190 ssh->bare_connection = FALSE;
11191 ssh->X11_fwd_enabled = FALSE;
11192 ssh->connshare = NULL;
11193 ssh->attempting_connshare = FALSE;
11194 ssh->session_started = FALSE;
11195 ssh->specials = NULL;
11196 ssh->n_uncert_hostkeys = 0;
11197 ssh->cross_certifying = FALSE;
11199 *backend_handle = ssh;
11202 if (crypto_startup() == 0)
11203 return "Microsoft high encryption pack not installed!";
11206 ssh->frontend = frontend_handle;
11207 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11208 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11210 ssh->channels = NULL;
11211 ssh->rportfwds = NULL;
11212 ssh->portfwds = NULL;
11217 ssh->conn_throttle_count = 0;
11218 ssh->overall_bufsize = 0;
11219 ssh->fallback_cmd = 0;
11221 ssh->protocol = NULL;
11223 ssh->protocol_initial_phase_done = FALSE;
11225 ssh->pinger = NULL;
11227 ssh->incoming_data_size = ssh->outgoing_data_size =
11228 ssh->deferred_data_size = 0L;
11229 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11230 CONF_ssh_rekey_data));
11231 ssh->kex_in_progress = FALSE;
11234 ssh->gsslibs = NULL;
11237 random_ref(); /* do this now - may be needed by sharing setup code */
11239 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11248 static void ssh_free(void *handle)
11250 Ssh ssh = (Ssh) handle;
11251 struct ssh_channel *c;
11252 struct ssh_rportfwd *pf;
11253 struct X11FakeAuth *auth;
11255 if (ssh->v1_cipher_ctx)
11256 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11257 if (ssh->cs_cipher_ctx)
11258 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11259 if (ssh->sc_cipher_ctx)
11260 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11261 if (ssh->cs_mac_ctx)
11262 ssh->csmac->free_context(ssh->cs_mac_ctx);
11263 if (ssh->sc_mac_ctx)
11264 ssh->scmac->free_context(ssh->sc_mac_ctx);
11265 if (ssh->cs_comp_ctx) {
11267 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11269 zlib_compress_cleanup(ssh->cs_comp_ctx);
11271 if (ssh->sc_comp_ctx) {
11273 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11275 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11278 dh_cleanup(ssh->kex_ctx);
11279 sfree(ssh->savedhost);
11281 while (ssh->queuelen-- > 0)
11282 ssh_free_packet(ssh->queue[ssh->queuelen]);
11285 while (ssh->qhead) {
11286 struct queued_handler *qh = ssh->qhead;
11287 ssh->qhead = qh->next;
11290 ssh->qhead = ssh->qtail = NULL;
11292 if (ssh->channels) {
11293 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11296 if (c->u.x11.xconn != NULL)
11297 x11_close(c->u.x11.xconn);
11299 case CHAN_SOCKDATA:
11300 case CHAN_SOCKDATA_DORMANT:
11301 if (c->u.pfd.pf != NULL)
11302 pfd_close(c->u.pfd.pf);
11305 if (ssh->version == 2) {
11306 struct outstanding_channel_request *ocr, *nocr;
11307 ocr = c->v.v2.chanreq_head;
11309 ocr->handler(c, NULL, ocr->ctx);
11314 bufchain_clear(&c->v.v2.outbuffer);
11318 freetree234(ssh->channels);
11319 ssh->channels = NULL;
11322 if (ssh->connshare)
11323 sharestate_free(ssh->connshare);
11325 if (ssh->rportfwds) {
11326 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11328 freetree234(ssh->rportfwds);
11329 ssh->rportfwds = NULL;
11331 sfree(ssh->deferred_send_data);
11333 x11_free_display(ssh->x11disp);
11334 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11335 x11_free_fake_auth(auth);
11336 freetree234(ssh->x11authtree);
11337 sfree(ssh->do_ssh_init_state);
11338 sfree(ssh->do_ssh1_login_state);
11339 sfree(ssh->do_ssh2_transport_state);
11340 sfree(ssh->do_ssh2_authconn_state);
11343 sfree(ssh->fullhostname);
11344 sfree(ssh->hostkey_str);
11345 sfree(ssh->specials);
11346 if (ssh->crcda_ctx) {
11347 crcda_free_context(ssh->crcda_ctx);
11348 ssh->crcda_ctx = NULL;
11351 ssh_do_close(ssh, TRUE);
11352 expire_timer_context(ssh);
11354 pinger_free(ssh->pinger);
11355 bufchain_clear(&ssh->queued_incoming_data);
11356 sfree(ssh->username);
11357 conf_free(ssh->conf);
11360 ssh_gss_cleanup(ssh->gsslibs);
11368 * Reconfigure the SSH backend.
11370 static void ssh_reconfig(void *handle, Conf *conf)
11372 Ssh ssh = (Ssh) handle;
11373 const char *rekeying = NULL;
11374 int rekey_mandatory = FALSE;
11375 unsigned long old_max_data_size;
11378 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11380 ssh_setup_portfwd(ssh, conf);
11382 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11383 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11385 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11386 unsigned long now = GETTICKCOUNT();
11388 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11389 rekeying = "timeout shortened";
11391 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11395 old_max_data_size = ssh->max_data_size;
11396 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11397 CONF_ssh_rekey_data));
11398 if (old_max_data_size != ssh->max_data_size &&
11399 ssh->max_data_size != 0) {
11400 if (ssh->outgoing_data_size > ssh->max_data_size ||
11401 ssh->incoming_data_size > ssh->max_data_size)
11402 rekeying = "data limit lowered";
11405 if (conf_get_int(ssh->conf, CONF_compression) !=
11406 conf_get_int(conf, CONF_compression)) {
11407 rekeying = "compression setting changed";
11408 rekey_mandatory = TRUE;
11411 for (i = 0; i < CIPHER_MAX; i++)
11412 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11413 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11414 rekeying = "cipher settings changed";
11415 rekey_mandatory = TRUE;
11417 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11418 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11419 rekeying = "cipher settings changed";
11420 rekey_mandatory = TRUE;
11423 conf_free(ssh->conf);
11424 ssh->conf = conf_copy(conf);
11425 ssh_cache_conf_values(ssh);
11427 if (!ssh->bare_connection && rekeying) {
11428 if (!ssh->kex_in_progress) {
11429 do_ssh2_transport(ssh, rekeying, -1, NULL);
11430 } else if (rekey_mandatory) {
11431 ssh->deferred_rekey_reason = rekeying;
11437 * Called to send data down the SSH connection.
11439 static int ssh_send(void *handle, const char *buf, int len)
11441 Ssh ssh = (Ssh) handle;
11443 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11446 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11448 return ssh_sendbuffer(ssh);
11452 * Called to query the current amount of buffered stdin data.
11454 static int ssh_sendbuffer(void *handle)
11456 Ssh ssh = (Ssh) handle;
11457 int override_value;
11459 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11463 * If the SSH socket itself has backed up, add the total backup
11464 * size on that to any individual buffer on the stdin channel.
11466 override_value = 0;
11467 if (ssh->throttled_all)
11468 override_value = ssh->overall_bufsize;
11470 if (ssh->version == 1) {
11471 return override_value;
11472 } else if (ssh->version == 2) {
11473 if (!ssh->mainchan)
11474 return override_value;
11476 return (override_value +
11477 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11484 * Called to set the size of the window from SSH's POV.
11486 static void ssh_size(void *handle, int width, int height)
11488 Ssh ssh = (Ssh) handle;
11489 struct Packet *pktout;
11491 ssh->term_width = width;
11492 ssh->term_height = height;
11494 switch (ssh->state) {
11495 case SSH_STATE_BEFORE_SIZE:
11496 case SSH_STATE_PREPACKET:
11497 case SSH_STATE_CLOSED:
11498 break; /* do nothing */
11499 case SSH_STATE_INTERMED:
11500 ssh->size_needed = TRUE; /* buffer for later */
11502 case SSH_STATE_SESSION:
11503 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11504 if (ssh->version == 1) {
11505 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11506 PKT_INT, ssh->term_height,
11507 PKT_INT, ssh->term_width,
11508 PKT_INT, 0, PKT_INT, 0, PKT_END);
11509 } else if (ssh->mainchan) {
11510 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11512 ssh2_pkt_adduint32(pktout, ssh->term_width);
11513 ssh2_pkt_adduint32(pktout, ssh->term_height);
11514 ssh2_pkt_adduint32(pktout, 0);
11515 ssh2_pkt_adduint32(pktout, 0);
11516 ssh2_pkt_send(ssh, pktout);
11524 * Return a list of the special codes that make sense in this
11527 static const struct telnet_special *ssh_get_specials(void *handle)
11529 static const struct telnet_special ssh1_ignore_special[] = {
11530 {"IGNORE message", TS_NOP}
11532 static const struct telnet_special ssh2_ignore_special[] = {
11533 {"IGNORE message", TS_NOP},
11535 static const struct telnet_special ssh2_rekey_special[] = {
11536 {"Repeat key exchange", TS_REKEY},
11538 static const struct telnet_special ssh2_session_specials[] = {
11541 /* These are the signal names defined by RFC 4254.
11542 * They include all the ISO C signals, but are a subset of the POSIX
11543 * required signals. */
11544 {"SIGINT (Interrupt)", TS_SIGINT},
11545 {"SIGTERM (Terminate)", TS_SIGTERM},
11546 {"SIGKILL (Kill)", TS_SIGKILL},
11547 {"SIGQUIT (Quit)", TS_SIGQUIT},
11548 {"SIGHUP (Hangup)", TS_SIGHUP},
11549 {"More signals", TS_SUBMENU},
11550 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11551 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11552 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11553 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11554 {NULL, TS_EXITMENU}
11556 static const struct telnet_special specials_end[] = {
11557 {NULL, TS_EXITMENU}
11560 struct telnet_special *specials = NULL;
11561 int nspecials = 0, specialsize = 0;
11563 Ssh ssh = (Ssh) handle;
11565 sfree(ssh->specials);
11567 #define ADD_SPECIALS(name) do \
11569 int len = lenof(name); \
11570 if (nspecials + len > specialsize) { \
11571 specialsize = (nspecials + len) * 5 / 4 + 32; \
11572 specials = sresize(specials, specialsize, struct telnet_special); \
11574 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11575 nspecials += len; \
11578 if (ssh->version == 1) {
11579 /* Don't bother offering IGNORE if we've decided the remote
11580 * won't cope with it, since we wouldn't bother sending it if
11582 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11583 ADD_SPECIALS(ssh1_ignore_special);
11584 } else if (ssh->version == 2) {
11585 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11586 ADD_SPECIALS(ssh2_ignore_special);
11587 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11588 ADD_SPECIALS(ssh2_rekey_special);
11590 ADD_SPECIALS(ssh2_session_specials);
11592 if (ssh->n_uncert_hostkeys) {
11593 static const struct telnet_special uncert_start[] = {
11595 {"Cache new host key type", TS_SUBMENU},
11597 static const struct telnet_special uncert_end[] = {
11598 {NULL, TS_EXITMENU},
11602 ADD_SPECIALS(uncert_start);
11603 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11604 struct telnet_special uncert[1];
11605 const struct ssh_signkey *alg =
11606 hostkey_algs[ssh->uncert_hostkeys[i]].alg;
11607 uncert[0].name = alg->name;
11608 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11609 ADD_SPECIALS(uncert);
11611 ADD_SPECIALS(uncert_end);
11613 } /* else we're not ready yet */
11616 ADD_SPECIALS(specials_end);
11618 ssh->specials = specials;
11625 #undef ADD_SPECIALS
11629 * Send special codes. TS_EOF is useful for `plink', so you
11630 * can send an EOF and collect resulting output (e.g. `plink
11633 static void ssh_special(void *handle, Telnet_Special code)
11635 Ssh ssh = (Ssh) handle;
11636 struct Packet *pktout;
11638 if (code == TS_EOF) {
11639 if (ssh->state != SSH_STATE_SESSION) {
11641 * Buffer the EOF in case we are pre-SESSION, so we can
11642 * send it as soon as we reach SESSION.
11644 if (code == TS_EOF)
11645 ssh->eof_needed = TRUE;
11648 if (ssh->version == 1) {
11649 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11650 } else if (ssh->mainchan) {
11651 sshfwd_write_eof(ssh->mainchan);
11652 ssh->send_ok = 0; /* now stop trying to read from stdin */
11654 logevent("Sent EOF message");
11655 } else if (code == TS_PING || code == TS_NOP) {
11656 if (ssh->state == SSH_STATE_CLOSED
11657 || ssh->state == SSH_STATE_PREPACKET) return;
11658 if (ssh->version == 1) {
11659 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11660 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11662 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11663 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11664 ssh2_pkt_addstring_start(pktout);
11665 ssh2_pkt_send_noqueue(ssh, pktout);
11668 } else if (code == TS_REKEY) {
11669 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11670 ssh->version == 2) {
11671 do_ssh2_transport(ssh, "at user request", -1, NULL);
11673 } else if (code >= TS_LOCALSTART) {
11674 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg;
11675 ssh->cross_certifying = TRUE;
11676 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11677 ssh->version == 2) {
11678 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11680 } else if (code == TS_BRK) {
11681 if (ssh->state == SSH_STATE_CLOSED
11682 || ssh->state == SSH_STATE_PREPACKET) return;
11683 if (ssh->version == 1) {
11684 logevent("Unable to send BREAK signal in SSH-1");
11685 } else if (ssh->mainchan) {
11686 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11687 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11688 ssh2_pkt_send(ssh, pktout);
11691 /* Is is a POSIX signal? */
11692 const char *signame = NULL;
11693 if (code == TS_SIGABRT) signame = "ABRT";
11694 if (code == TS_SIGALRM) signame = "ALRM";
11695 if (code == TS_SIGFPE) signame = "FPE";
11696 if (code == TS_SIGHUP) signame = "HUP";
11697 if (code == TS_SIGILL) signame = "ILL";
11698 if (code == TS_SIGINT) signame = "INT";
11699 if (code == TS_SIGKILL) signame = "KILL";
11700 if (code == TS_SIGPIPE) signame = "PIPE";
11701 if (code == TS_SIGQUIT) signame = "QUIT";
11702 if (code == TS_SIGSEGV) signame = "SEGV";
11703 if (code == TS_SIGTERM) signame = "TERM";
11704 if (code == TS_SIGUSR1) signame = "USR1";
11705 if (code == TS_SIGUSR2) signame = "USR2";
11706 /* The SSH-2 protocol does in principle support arbitrary named
11707 * signals, including signame@domain, but we don't support those. */
11709 /* It's a signal. */
11710 if (ssh->version == 2 && ssh->mainchan) {
11711 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11712 ssh2_pkt_addstring(pktout, signame);
11713 ssh2_pkt_send(ssh, pktout);
11714 logeventf(ssh, "Sent signal SIG%s", signame);
11717 /* Never heard of it. Do nothing */
11722 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11724 Ssh ssh = (Ssh) handle;
11725 struct ssh_channel *c;
11726 c = snew(struct ssh_channel);
11729 ssh_channel_init(c);
11730 c->halfopen = TRUE;
11731 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11736 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11738 struct ssh_channel *c;
11739 c = snew(struct ssh_channel);
11742 ssh_channel_init(c);
11743 c->type = CHAN_SHARING;
11744 c->u.sharing.ctx = sharing_ctx;
11748 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11750 struct ssh_channel *c;
11752 c = find234(ssh->channels, &localid, ssh_channelfind);
11754 ssh_channel_destroy(c);
11757 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11758 const void *data, int datalen,
11759 const char *additional_log_text)
11761 struct Packet *pkt;
11763 pkt = ssh2_pkt_init(type);
11764 pkt->downstream_id = id;
11765 pkt->additional_log_text = additional_log_text;
11766 ssh2_pkt_adddata(pkt, data, datalen);
11767 ssh2_pkt_send(ssh, pkt);
11771 * This is called when stdout/stderr (the entity to which
11772 * from_backend sends data) manages to clear some backlog.
11774 static void ssh_unthrottle(void *handle, int bufsize)
11776 Ssh ssh = (Ssh) handle;
11778 if (ssh->version == 1) {
11779 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11780 ssh->v1_stdout_throttling = 0;
11781 ssh_throttle_conn(ssh, -1);
11785 ssh_channel_unthrottle(ssh->mainchan, bufsize);
11789 * Now process any SSH connection data that was stashed in our
11790 * queue while we were frozen.
11792 ssh_process_queued_incoming_data(ssh);
11795 void ssh_send_port_open(void *channel, const char *hostname, int port,
11798 struct ssh_channel *c = (struct ssh_channel *)channel;
11800 struct Packet *pktout;
11802 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11804 if (ssh->version == 1) {
11805 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11806 PKT_INT, c->localid,
11809 /* PKT_STR, <org:orgport>, */
11812 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11814 char *trimmed_host = host_strduptrim(hostname);
11815 ssh2_pkt_addstring(pktout, trimmed_host);
11816 sfree(trimmed_host);
11818 ssh2_pkt_adduint32(pktout, port);
11820 * We make up values for the originator data; partly it's
11821 * too much hassle to keep track, and partly I'm not
11822 * convinced the server should be told details like that
11823 * about my local network configuration.
11824 * The "originator IP address" is syntactically a numeric
11825 * IP address, and some servers (e.g., Tectia) get upset
11826 * if it doesn't match this syntax.
11828 ssh2_pkt_addstring(pktout, "0.0.0.0");
11829 ssh2_pkt_adduint32(pktout, 0);
11830 ssh2_pkt_send(ssh, pktout);
11834 static int ssh_connected(void *handle)
11836 Ssh ssh = (Ssh) handle;
11837 return ssh->s != NULL;
11840 static int ssh_sendok(void *handle)
11842 Ssh ssh = (Ssh) handle;
11843 return ssh->send_ok;
11846 static int ssh_ldisc(void *handle, int option)
11848 Ssh ssh = (Ssh) handle;
11849 if (option == LD_ECHO)
11850 return ssh->echoing;
11851 if (option == LD_EDIT)
11852 return ssh->editing;
11856 static void ssh_provide_ldisc(void *handle, void *ldisc)
11858 Ssh ssh = (Ssh) handle;
11859 ssh->ldisc = ldisc;
11862 static void ssh_provide_logctx(void *handle, void *logctx)
11864 Ssh ssh = (Ssh) handle;
11865 ssh->logctx = logctx;
11868 static int ssh_return_exitcode(void *handle)
11870 Ssh ssh = (Ssh) handle;
11871 if (ssh->s != NULL)
11874 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11878 * cfg_info for SSH is the protocol running in this session.
11879 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11880 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11882 static int ssh_cfg_info(void *handle)
11884 Ssh ssh = (Ssh) handle;
11885 if (ssh->version == 0)
11886 return 0; /* don't know yet */
11887 else if (ssh->bare_connection)
11890 return ssh->version;
11894 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11895 * that fails. This variable is the means by which scp.c can reach
11896 * into the SSH code and find out which one it got.
11898 extern int ssh_fallback_cmd(void *handle)
11900 Ssh ssh = (Ssh) handle;
11901 return ssh->fallback_cmd;
11904 Backend ssh_backend = {
11914 ssh_return_exitcode,
11918 ssh_provide_logctx,
11921 ssh_test_for_upstream,