28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
40 SSH2_PKTCTX_PUBLICKEY,
46 static const char *const ssh2_disconnect_reasons[] = {
48 "host not allowed to connect",
50 "key exchange failed",
51 "host authentication failed",
54 "service not available",
55 "protocol version not supported",
56 "host key not verifiable",
59 "too many connections",
60 "auth cancelled by user",
61 "no more auth methods available",
66 * Various remote-bug flags.
68 #define BUG_CHOKES_ON_SSH1_IGNORE 1
69 #define BUG_SSH2_HMAC 2
70 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
71 #define BUG_CHOKES_ON_RSA 8
72 #define BUG_SSH2_RSA_PADDING 16
73 #define BUG_SSH2_DERIVEKEY 32
74 #define BUG_SSH2_REKEY 64
75 #define BUG_SSH2_PK_SESSIONID 128
76 #define BUG_SSH2_MAXPKT 256
77 #define BUG_CHOKES_ON_SSH2_IGNORE 512
78 #define BUG_CHOKES_ON_WINADJ 1024
79 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
80 #define BUG_SSH2_OLDGEX 4096
82 #define DH_MIN_SIZE 1024
83 #define DH_MAX_SIZE 8192
86 * Codes for terminal modes.
87 * Most of these are the same in SSH-1 and SSH-2.
88 * This list is derived from RFC 4254 and
92 const char* const mode;
94 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
96 /* "V" prefix discarded for special characters relative to SSH specs */
97 { "INTR", 1, TTY_OP_CHAR },
98 { "QUIT", 2, TTY_OP_CHAR },
99 { "ERASE", 3, TTY_OP_CHAR },
100 { "KILL", 4, TTY_OP_CHAR },
101 { "EOF", 5, TTY_OP_CHAR },
102 { "EOL", 6, TTY_OP_CHAR },
103 { "EOL2", 7, TTY_OP_CHAR },
104 { "START", 8, TTY_OP_CHAR },
105 { "STOP", 9, TTY_OP_CHAR },
106 { "SUSP", 10, TTY_OP_CHAR },
107 { "DSUSP", 11, TTY_OP_CHAR },
108 { "REPRINT", 12, TTY_OP_CHAR },
109 { "WERASE", 13, TTY_OP_CHAR },
110 { "LNEXT", 14, TTY_OP_CHAR },
111 { "FLUSH", 15, TTY_OP_CHAR },
112 { "SWTCH", 16, TTY_OP_CHAR },
113 { "STATUS", 17, TTY_OP_CHAR },
114 { "DISCARD", 18, TTY_OP_CHAR },
115 { "IGNPAR", 30, TTY_OP_BOOL },
116 { "PARMRK", 31, TTY_OP_BOOL },
117 { "INPCK", 32, TTY_OP_BOOL },
118 { "ISTRIP", 33, TTY_OP_BOOL },
119 { "INLCR", 34, TTY_OP_BOOL },
120 { "IGNCR", 35, TTY_OP_BOOL },
121 { "ICRNL", 36, TTY_OP_BOOL },
122 { "IUCLC", 37, TTY_OP_BOOL },
123 { "IXON", 38, TTY_OP_BOOL },
124 { "IXANY", 39, TTY_OP_BOOL },
125 { "IXOFF", 40, TTY_OP_BOOL },
126 { "IMAXBEL", 41, TTY_OP_BOOL },
127 { "ISIG", 50, TTY_OP_BOOL },
128 { "ICANON", 51, TTY_OP_BOOL },
129 { "XCASE", 52, TTY_OP_BOOL },
130 { "ECHO", 53, TTY_OP_BOOL },
131 { "ECHOE", 54, TTY_OP_BOOL },
132 { "ECHOK", 55, TTY_OP_BOOL },
133 { "ECHONL", 56, TTY_OP_BOOL },
134 { "NOFLSH", 57, TTY_OP_BOOL },
135 { "TOSTOP", 58, TTY_OP_BOOL },
136 { "IEXTEN", 59, TTY_OP_BOOL },
137 { "ECHOCTL", 60, TTY_OP_BOOL },
138 { "ECHOKE", 61, TTY_OP_BOOL },
139 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
140 { "OPOST", 70, TTY_OP_BOOL },
141 { "OLCUC", 71, TTY_OP_BOOL },
142 { "ONLCR", 72, TTY_OP_BOOL },
143 { "OCRNL", 73, TTY_OP_BOOL },
144 { "ONOCR", 74, TTY_OP_BOOL },
145 { "ONLRET", 75, TTY_OP_BOOL },
146 { "CS7", 90, TTY_OP_BOOL },
147 { "CS8", 91, TTY_OP_BOOL },
148 { "PARENB", 92, TTY_OP_BOOL },
149 { "PARODD", 93, TTY_OP_BOOL }
152 /* Miscellaneous other tty-related constants. */
153 #define SSH_TTY_OP_END 0
154 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
155 #define SSH1_TTY_OP_ISPEED 192
156 #define SSH1_TTY_OP_OSPEED 193
157 #define SSH2_TTY_OP_ISPEED 128
158 #define SSH2_TTY_OP_OSPEED 129
160 /* Helper functions for parsing tty-related config. */
161 static unsigned int ssh_tty_parse_specchar(char *s)
166 ret = ctrlparse(s, &next);
167 if (!next) ret = s[0];
169 ret = 255; /* special value meaning "don't set" */
173 static unsigned int ssh_tty_parse_boolean(char *s)
175 if (stricmp(s, "yes") == 0 ||
176 stricmp(s, "on") == 0 ||
177 stricmp(s, "true") == 0 ||
178 stricmp(s, "+") == 0)
180 else if (stricmp(s, "no") == 0 ||
181 stricmp(s, "off") == 0 ||
182 stricmp(s, "false") == 0 ||
183 stricmp(s, "-") == 0)
184 return 0; /* false */
186 return (atoi(s) != 0);
189 #define translate(x) if (type == x) return #x
190 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
191 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
192 static char *ssh1_pkt_type(int type)
194 translate(SSH1_MSG_DISCONNECT);
195 translate(SSH1_SMSG_PUBLIC_KEY);
196 translate(SSH1_CMSG_SESSION_KEY);
197 translate(SSH1_CMSG_USER);
198 translate(SSH1_CMSG_AUTH_RSA);
199 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
200 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
201 translate(SSH1_CMSG_AUTH_PASSWORD);
202 translate(SSH1_CMSG_REQUEST_PTY);
203 translate(SSH1_CMSG_WINDOW_SIZE);
204 translate(SSH1_CMSG_EXEC_SHELL);
205 translate(SSH1_CMSG_EXEC_CMD);
206 translate(SSH1_SMSG_SUCCESS);
207 translate(SSH1_SMSG_FAILURE);
208 translate(SSH1_CMSG_STDIN_DATA);
209 translate(SSH1_SMSG_STDOUT_DATA);
210 translate(SSH1_SMSG_STDERR_DATA);
211 translate(SSH1_CMSG_EOF);
212 translate(SSH1_SMSG_EXIT_STATUS);
213 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
214 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
215 translate(SSH1_MSG_CHANNEL_DATA);
216 translate(SSH1_MSG_CHANNEL_CLOSE);
217 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
218 translate(SSH1_SMSG_X11_OPEN);
219 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
220 translate(SSH1_MSG_PORT_OPEN);
221 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
222 translate(SSH1_SMSG_AGENT_OPEN);
223 translate(SSH1_MSG_IGNORE);
224 translate(SSH1_CMSG_EXIT_CONFIRMATION);
225 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
226 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
227 translate(SSH1_MSG_DEBUG);
228 translate(SSH1_CMSG_REQUEST_COMPRESSION);
229 translate(SSH1_CMSG_AUTH_TIS);
230 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
231 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
232 translate(SSH1_CMSG_AUTH_CCARD);
233 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
234 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
237 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
239 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
240 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
245 translate(SSH2_MSG_DISCONNECT);
246 translate(SSH2_MSG_IGNORE);
247 translate(SSH2_MSG_UNIMPLEMENTED);
248 translate(SSH2_MSG_DEBUG);
249 translate(SSH2_MSG_SERVICE_REQUEST);
250 translate(SSH2_MSG_SERVICE_ACCEPT);
251 translate(SSH2_MSG_KEXINIT);
252 translate(SSH2_MSG_NEWKEYS);
253 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
254 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
255 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
256 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
257 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
261 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
262 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
263 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
264 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
265 translate(SSH2_MSG_USERAUTH_REQUEST);
266 translate(SSH2_MSG_USERAUTH_FAILURE);
267 translate(SSH2_MSG_USERAUTH_SUCCESS);
268 translate(SSH2_MSG_USERAUTH_BANNER);
269 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
270 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
271 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
272 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
273 translate(SSH2_MSG_GLOBAL_REQUEST);
274 translate(SSH2_MSG_REQUEST_SUCCESS);
275 translate(SSH2_MSG_REQUEST_FAILURE);
276 translate(SSH2_MSG_CHANNEL_OPEN);
277 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
278 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
279 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
280 translate(SSH2_MSG_CHANNEL_DATA);
281 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
282 translate(SSH2_MSG_CHANNEL_EOF);
283 translate(SSH2_MSG_CHANNEL_CLOSE);
284 translate(SSH2_MSG_CHANNEL_REQUEST);
285 translate(SSH2_MSG_CHANNEL_SUCCESS);
286 translate(SSH2_MSG_CHANNEL_FAILURE);
292 /* Enumeration values for fields in SSH-1 packets */
294 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
298 * Coroutine mechanics for the sillier bits of the code. If these
299 * macros look impenetrable to you, you might find it helpful to
302 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
304 * which explains the theory behind these macros.
306 * In particular, if you are getting `case expression not constant'
307 * errors when building with MS Visual Studio, this is because MS's
308 * Edit and Continue debugging feature causes their compiler to
309 * violate ANSI C. To disable Edit and Continue debugging:
311 * - right-click ssh.c in the FileView
313 * - select the C/C++ tab and the General category
314 * - under `Debug info:', select anything _other_ than `Program
315 * Database for Edit and Continue'.
317 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
318 #define crBeginState crBegin(s->crLine)
319 #define crStateP(t, v) \
321 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
323 #define crState(t) crStateP(t, ssh->t)
324 #define crFinish(z) } *crLine = 0; return (z); }
325 #define crFinishV } *crLine = 0; return; }
326 #define crFinishFree(z) } sfree(s); return (z); }
327 #define crFinishFreeV } sfree(s); return; }
328 #define crReturn(z) \
330 *crLine =__LINE__; return (z); case __LINE__:;\
334 *crLine=__LINE__; return; case __LINE__:;\
336 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
337 #define crStopV do{ *crLine = 0; return; }while(0)
338 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
339 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
343 static struct Packet *ssh1_pkt_init(int pkt_type);
344 static struct Packet *ssh2_pkt_init(int pkt_type);
345 static void ssh_pkt_ensure(struct Packet *, int length);
346 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
347 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
348 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
349 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
350 static void ssh_pkt_addstring_start(struct Packet *);
351 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
352 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
353 static void ssh_pkt_addstring(struct Packet *, const char *data);
354 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
355 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
356 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
357 static int ssh2_pkt_construct(Ssh, struct Packet *);
358 static void ssh2_pkt_send(Ssh, struct Packet *);
359 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
360 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
361 struct Packet *pktin);
362 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
363 struct Packet *pktin);
364 static void ssh2_channel_check_close(struct ssh_channel *c);
365 static void ssh_channel_destroy(struct ssh_channel *c);
368 * Buffer management constants. There are several of these for
369 * various different purposes:
371 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
372 * on a local data stream before we throttle the whole SSH
373 * connection (in SSH-1 only). Throttling the whole connection is
374 * pretty drastic so we set this high in the hope it won't
377 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
378 * on the SSH connection itself before we defensively throttle
379 * _all_ local data streams. This is pretty drastic too (though
380 * thankfully unlikely in SSH-2 since the window mechanism should
381 * ensure that the server never has any need to throttle its end
382 * of the connection), so we set this high as well.
384 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
387 * - OUR_V2_BIGWIN is the window size we advertise for the only
388 * channel in a simple connection. It must be <= INT_MAX.
390 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
391 * to the remote side. This actually has nothing to do with the
392 * size of the _packet_, but is instead a limit on the amount
393 * of data we're willing to receive in a single SSH2 channel
396 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
397 * _packet_ we're prepared to cope with. It must be a multiple
398 * of the cipher block size, and must be at least 35000.
401 #define SSH1_BUFFER_LIMIT 32768
402 #define SSH_MAX_BACKLOG 32768
403 #define OUR_V2_WINSIZE 16384
404 #define OUR_V2_BIGWIN 0x7fffffff
405 #define OUR_V2_MAXPKT 0x4000UL
406 #define OUR_V2_PACKETLIMIT 0x9000UL
408 const static struct ssh_signkey *hostkey_algs[] = {
410 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
414 const static struct ssh_mac *macs[] = {
415 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
417 const static struct ssh_mac *buggymacs[] = {
418 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
421 static void *ssh_comp_none_init(void)
425 static void ssh_comp_none_cleanup(void *handle)
428 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
429 unsigned char **outblock, int *outlen)
433 static int ssh_comp_none_disable(void *handle)
437 const static struct ssh_compress ssh_comp_none = {
439 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
440 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
441 ssh_comp_none_disable, NULL
443 extern const struct ssh_compress ssh_zlib;
444 const static struct ssh_compress *compressions[] = {
445 &ssh_zlib, &ssh_comp_none
448 enum { /* channel types */
453 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
455 * CHAN_SHARING indicates a channel which is tracked here on
456 * behalf of a connection-sharing downstream. We do almost nothing
457 * with these channels ourselves: all messages relating to them
458 * get thrown straight to sshshare.c and passed on almost
459 * unmodified to downstream.
463 * CHAN_ZOMBIE is used to indicate a channel for which we've
464 * already destroyed the local data source: for instance, if a
465 * forwarded port experiences a socket error on the local side, we
466 * immediately destroy its local socket and turn the SSH channel
472 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
473 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
474 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
477 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
480 struct outstanding_channel_request {
481 cchandler_fn_t handler;
483 struct outstanding_channel_request *next;
487 * 2-3-4 tree storing channels.
490 Ssh ssh; /* pointer back to main context */
491 unsigned remoteid, localid;
493 /* True if we opened this channel but server hasn't confirmed. */
496 * In SSH-1, this value contains four bits:
498 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
499 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
500 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
501 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
503 * A channel is completely finished with when all four bits are set.
505 * In SSH-2, the four bits mean:
507 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
508 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
509 * 4 We have received SSH2_MSG_CHANNEL_EOF.
510 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
512 * A channel is completely finished with when we have both sent
513 * and received CLOSE.
515 * The symbolic constants below use the SSH-2 terminology, which
516 * is a bit confusing in SSH-1, but we have to use _something_.
518 #define CLOSES_SENT_EOF 1
519 #define CLOSES_SENT_CLOSE 2
520 #define CLOSES_RCVD_EOF 4
521 #define CLOSES_RCVD_CLOSE 8
525 * This flag indicates that an EOF is pending on the outgoing side
526 * of the channel: that is, wherever we're getting the data for
527 * this channel has sent us some data followed by EOF. We can't
528 * actually send the EOF until we've finished sending the data, so
529 * we set this flag instead to remind us to do so once our buffer
535 * True if this channel is causing the underlying connection to be
540 struct ssh2_data_channel {
542 unsigned remwindow, remmaxpkt;
543 /* locwindow is signed so we can cope with excess data. */
544 int locwindow, locmaxwin;
546 * remlocwin is the amount of local window that we think
547 * the remote end had available to it after it sent the
548 * last data packet or window adjust ack.
552 * These store the list of channel requests that haven't
555 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
556 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
560 struct ssh_agent_channel {
561 unsigned char *message;
562 unsigned char msglen[4];
563 unsigned lensofar, totallen;
564 int outstanding_requests;
566 struct ssh_x11_channel {
567 struct X11Connection *xconn;
570 struct ssh_pfd_channel {
571 struct PortForwarding *pf;
573 struct ssh_sharing_channel {
580 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
581 * use this structure in different ways, reflecting SSH-2's
582 * altogether saner approach to port forwarding.
584 * In SSH-1, you arrange a remote forwarding by sending the server
585 * the remote port number, and the local destination host:port.
586 * When a connection comes in, the server sends you back that
587 * host:port pair, and you connect to it. This is a ready-made
588 * security hole if you're not on the ball: a malicious server
589 * could send you back _any_ host:port pair, so if you trustingly
590 * connect to the address it gives you then you've just opened the
591 * entire inside of your corporate network just by connecting
592 * through it to a dodgy SSH server. Hence, we must store a list of
593 * host:port pairs we _are_ trying to forward to, and reject a
594 * connection request from the server if it's not in the list.
596 * In SSH-2, each side of the connection minds its own business and
597 * doesn't send unnecessary information to the other. You arrange a
598 * remote forwarding by sending the server just the remote port
599 * number. When a connection comes in, the server tells you which
600 * of its ports was connected to; and _you_ have to remember what
601 * local host:port pair went with that port number.
603 * Hence, in SSH-1 this structure is indexed by destination
604 * host:port pair, whereas in SSH-2 it is indexed by source port.
606 struct ssh_portfwd; /* forward declaration */
608 struct ssh_rportfwd {
609 unsigned sport, dport;
613 struct ssh_portfwd *pfrec;
616 static void free_rportfwd(struct ssh_rportfwd *pf)
619 sfree(pf->sportdesc);
627 * Separately to the rportfwd tree (which is for looking up port
628 * open requests from the server), a tree of _these_ structures is
629 * used to keep track of all the currently open port forwardings,
630 * so that we can reconfigure in mid-session if the user requests
634 enum { DESTROY, KEEP, CREATE } status;
636 unsigned sport, dport;
639 struct ssh_rportfwd *remote;
641 struct PortListener *local;
643 #define free_portfwd(pf) ( \
644 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
645 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
648 long length; /* length of packet: see below */
649 long forcepad; /* SSH-2: force padding to at least this length */
650 int type; /* only used for incoming packets */
651 unsigned long sequence; /* SSH-2 incoming sequence number */
652 unsigned char *data; /* allocated storage */
653 unsigned char *body; /* offset of payload within `data' */
654 long savedpos; /* dual-purpose saved packet position: see below */
655 long maxlen; /* amount of storage allocated for `data' */
656 long encrypted_len; /* for SSH-2 total-size counting */
659 * A note on the 'length' and 'savedpos' fields above.
661 * Incoming packets are set up so that pkt->length is measured
662 * relative to pkt->body, which itself points to a few bytes after
663 * pkt->data (skipping some uninteresting header fields including
664 * the packet type code). The ssh_pkt_get* functions all expect
665 * this setup, and they also use pkt->savedpos to indicate how far
666 * through the packet being decoded they've got - and that, too,
667 * is an offset from pkt->body rather than pkt->data.
669 * During construction of an outgoing packet, however, pkt->length
670 * is measured relative to the base pointer pkt->data, and
671 * pkt->body is not really used for anything until the packet is
672 * ready for sending. In this mode, pkt->savedpos is reused as a
673 * temporary variable by the addstring functions, which write out
674 * a string length field and then keep going back and updating it
675 * as more data is appended to the subsequent string data field;
676 * pkt->savedpos stores the offset (again relative to pkt->data)
677 * of the start of the string data field.
680 /* Extra metadata used in SSH packet logging mode, allowing us to
681 * log in the packet header line that the packet came from a
682 * connection-sharing downstream and what if anything unusual was
683 * done to it. The additional_log_text field is expected to be a
684 * static string - it will not be freed. */
685 unsigned downstream_id;
686 const char *additional_log_text;
689 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
690 struct Packet *pktin);
691 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
692 struct Packet *pktin);
693 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
694 struct Packet *pktin);
695 static void ssh1_protocol_setup(Ssh ssh);
696 static void ssh2_protocol_setup(Ssh ssh);
697 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
698 static void ssh_size(void *handle, int width, int height);
699 static void ssh_special(void *handle, Telnet_Special);
700 static int ssh2_try_send(struct ssh_channel *c);
701 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
702 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
703 static void ssh2_set_window(struct ssh_channel *c, int newwin);
704 static int ssh_sendbuffer(void *handle);
705 static int ssh_do_close(Ssh ssh, int notify_exit);
706 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
707 static int ssh2_pkt_getbool(struct Packet *pkt);
708 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
709 static void ssh2_timer(void *ctx, unsigned long now);
710 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
711 struct Packet *pktin);
712 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
714 struct rdpkt1_state_tag {
715 long len, pad, biglen, to_read;
716 unsigned long realcrc, gotcrc;
720 struct Packet *pktin;
723 struct rdpkt2_state_tag {
724 long len, pad, payload, packetlen, maclen;
727 unsigned long incoming_sequence;
728 struct Packet *pktin;
731 struct rdpkt2_bare_state_tag {
735 unsigned long incoming_sequence;
736 struct Packet *pktin;
739 struct queued_handler;
740 struct queued_handler {
742 chandler_fn_t handler;
744 struct queued_handler *next;
748 const struct plug_function_table *fn;
749 /* the above field _must_ be first in the structure */
759 unsigned char session_key[32];
761 int v1_remote_protoflags;
762 int v1_local_protoflags;
763 int agentfwd_enabled;
766 const struct ssh_cipher *cipher;
769 const struct ssh2_cipher *cscipher, *sccipher;
770 void *cs_cipher_ctx, *sc_cipher_ctx;
771 const struct ssh_mac *csmac, *scmac;
772 int csmac_etm, scmac_etm;
773 void *cs_mac_ctx, *sc_mac_ctx;
774 const struct ssh_compress *cscomp, *sccomp;
775 void *cs_comp_ctx, *sc_comp_ctx;
776 const struct ssh_kex *kex;
777 const struct ssh_signkey *hostkey;
778 char *hostkey_str; /* string representation, for easy checking in rekeys */
779 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
780 int v2_session_id_len;
784 int attempting_connshare;
790 int echoing, editing;
794 int ospeed, ispeed; /* temporaries */
795 int term_width, term_height;
797 tree234 *channels; /* indexed by local id */
798 struct ssh_channel *mainchan; /* primary session channel */
799 int ncmode; /* is primary channel direct-tcpip? */
804 tree234 *rportfwds, *portfwds;
808 SSH_STATE_BEFORE_SIZE,
814 int size_needed, eof_needed;
815 int sent_console_eof;
816 int got_pty; /* affects EOF behaviour on main channel */
818 struct Packet **queue;
819 int queuelen, queuesize;
821 unsigned char *deferred_send_data;
822 int deferred_len, deferred_size;
825 * Gross hack: pscp will try to start SFTP but fall back to
826 * scp1 if that fails. This variable is the means by which
827 * scp.c can reach into the SSH code and find out which one it
832 bufchain banner; /* accumulates banners during do_ssh2_authconn */
837 struct X11Display *x11disp;
838 struct X11FakeAuth *x11auth;
839 tree234 *x11authtree;
842 int conn_throttle_count;
845 int v1_stdout_throttling;
846 unsigned long v2_outgoing_sequence;
848 int ssh1_rdpkt_crstate;
849 int ssh2_rdpkt_crstate;
850 int ssh2_bare_rdpkt_crstate;
851 int ssh_gotdata_crstate;
852 int do_ssh1_connection_crstate;
854 void *do_ssh_init_state;
855 void *do_ssh1_login_state;
856 void *do_ssh2_transport_state;
857 void *do_ssh2_authconn_state;
858 void *do_ssh_connection_init_state;
860 struct rdpkt1_state_tag rdpkt1_state;
861 struct rdpkt2_state_tag rdpkt2_state;
862 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
864 /* SSH-1 and SSH-2 use this for different things, but both use it */
865 int protocol_initial_phase_done;
867 void (*protocol) (Ssh ssh, void *vin, int inlen,
869 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
870 int (*do_ssh_init)(Ssh ssh, unsigned char c);
873 * We maintain our own copy of a Conf structure here. That way,
874 * when we're passed a new one for reconfiguration, we can check
875 * the differences and potentially reconfigure port forwardings
876 * etc in mid-session.
881 * Values cached out of conf so as to avoid the tree234 lookup
882 * cost every time they're used.
887 * Dynamically allocated username string created during SSH
888 * login. Stored in here rather than in the coroutine state so
889 * that it'll be reliably freed if we shut down the SSH session
890 * at some unexpected moment.
895 * Used to transfer data back from async callbacks.
897 void *agent_response;
898 int agent_response_len;
902 * The SSH connection can be set as `frozen', meaning we are
903 * not currently accepting incoming data from the network. This
904 * is slightly more serious than setting the _socket_ as
905 * frozen, because we may already have had data passed to us
906 * from the network which we need to delay processing until
907 * after the freeze is lifted, so we also need a bufchain to
911 bufchain queued_incoming_data;
914 * Dispatch table for packet types that we may have to deal
917 handler_fn_t packet_dispatch[256];
920 * Queues of one-off handler functions for success/failure
921 * indications from a request.
923 struct queued_handler *qhead, *qtail;
924 handler_fn_t q_saved_handler1, q_saved_handler2;
927 * This module deals with sending keepalives.
932 * Track incoming and outgoing data sizes and time, for
935 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
936 unsigned long max_data_size;
938 unsigned long next_rekey, last_rekey;
939 char *deferred_rekey_reason; /* points to STATIC string; don't free */
942 * Fully qualified host name, which we need if doing GSSAPI.
948 * GSSAPI libraries for this session.
950 struct ssh_gss_liblist *gsslibs;
954 #define logevent(s) logevent(ssh->frontend, s)
956 /* logevent, only printf-formatted. */
957 static void logeventf(Ssh ssh, const char *fmt, ...)
963 buf = dupvprintf(fmt, ap);
969 static void bomb_out(Ssh ssh, char *text)
971 ssh_do_close(ssh, FALSE);
973 connection_fatal(ssh->frontend, "%s", text);
977 #define bombout(msg) bomb_out(ssh, dupprintf msg)
979 /* Helper function for common bits of parsing ttymodes. */
980 static void parse_ttymodes(Ssh ssh,
981 void (*do_mode)(void *data, char *mode, char *val),
986 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
988 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
990 * val[0] is either 'V', indicating that an explicit value
991 * follows it, or 'A' indicating that we should pass the
992 * value through from the local environment via get_ttymode.
995 val = get_ttymode(ssh->frontend, key);
997 do_mode(data, key, val);
1001 do_mode(data, key, val + 1); /* skip the 'V' */
1005 static int ssh_channelcmp(void *av, void *bv)
1007 struct ssh_channel *a = (struct ssh_channel *) av;
1008 struct ssh_channel *b = (struct ssh_channel *) bv;
1009 if (a->localid < b->localid)
1011 if (a->localid > b->localid)
1015 static int ssh_channelfind(void *av, void *bv)
1017 unsigned *a = (unsigned *) av;
1018 struct ssh_channel *b = (struct ssh_channel *) bv;
1019 if (*a < b->localid)
1021 if (*a > b->localid)
1026 static int ssh_rportcmp_ssh1(void *av, void *bv)
1028 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1029 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1031 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1032 return i < 0 ? -1 : +1;
1033 if (a->dport > b->dport)
1035 if (a->dport < b->dport)
1040 static int ssh_rportcmp_ssh2(void *av, void *bv)
1042 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1043 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1045 if ( (i = strcmp(a->shost, b->shost)) != 0)
1046 return i < 0 ? -1 : +1;
1047 if (a->sport > b->sport)
1049 if (a->sport < b->sport)
1055 * Special form of strcmp which can cope with NULL inputs. NULL is
1056 * defined to sort before even the empty string.
1058 static int nullstrcmp(const char *a, const char *b)
1060 if (a == NULL && b == NULL)
1066 return strcmp(a, b);
1069 static int ssh_portcmp(void *av, void *bv)
1071 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1072 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1074 if (a->type > b->type)
1076 if (a->type < b->type)
1078 if (a->addressfamily > b->addressfamily)
1080 if (a->addressfamily < b->addressfamily)
1082 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1083 return i < 0 ? -1 : +1;
1084 if (a->sport > b->sport)
1086 if (a->sport < b->sport)
1088 if (a->type != 'D') {
1089 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1090 return i < 0 ? -1 : +1;
1091 if (a->dport > b->dport)
1093 if (a->dport < b->dport)
1099 static int alloc_channel_id(Ssh ssh)
1101 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1102 unsigned low, high, mid;
1104 struct ssh_channel *c;
1107 * First-fit allocation of channel numbers: always pick the
1108 * lowest unused one. To do this, binary-search using the
1109 * counted B-tree to find the largest channel ID which is in a
1110 * contiguous sequence from the beginning. (Precisely
1111 * everything in that sequence must have ID equal to its tree
1112 * index plus CHANNEL_NUMBER_OFFSET.)
1114 tsize = count234(ssh->channels);
1118 while (high - low > 1) {
1119 mid = (high + low) / 2;
1120 c = index234(ssh->channels, mid);
1121 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1122 low = mid; /* this one is fine */
1124 high = mid; /* this one is past it */
1127 * Now low points to either -1, or the tree index of the
1128 * largest ID in the initial sequence.
1131 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1132 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1134 return low + 1 + CHANNEL_NUMBER_OFFSET;
1137 static void c_write_stderr(int trusted, const char *buf, int len)
1140 for (i = 0; i < len; i++)
1141 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1142 fputc(buf[i], stderr);
1145 static void c_write(Ssh ssh, const char *buf, int len)
1147 if (flags & FLAG_STDERR)
1148 c_write_stderr(1, buf, len);
1150 from_backend(ssh->frontend, 1, buf, len);
1153 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1155 if (flags & FLAG_STDERR)
1156 c_write_stderr(0, buf, len);
1158 from_backend_untrusted(ssh->frontend, buf, len);
1161 static void c_write_str(Ssh ssh, const char *buf)
1163 c_write(ssh, buf, strlen(buf));
1166 static void ssh_free_packet(struct Packet *pkt)
1171 static struct Packet *ssh_new_packet(void)
1173 struct Packet *pkt = snew(struct Packet);
1175 pkt->body = pkt->data = NULL;
1181 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1184 struct logblank_t blanks[4];
1190 if (ssh->logomitdata &&
1191 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1192 pkt->type == SSH1_SMSG_STDERR_DATA ||
1193 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1194 /* "Session data" packets - omit the data string. */
1195 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1196 ssh_pkt_getuint32(pkt); /* skip channel id */
1197 blanks[nblanks].offset = pkt->savedpos + 4;
1198 blanks[nblanks].type = PKTLOG_OMIT;
1199 ssh_pkt_getstring(pkt, &str, &slen);
1201 blanks[nblanks].len = slen;
1205 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1206 ssh1_pkt_type(pkt->type),
1207 pkt->body, pkt->length, nblanks, blanks, NULL,
1211 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1214 struct logblank_t blanks[4];
1219 * For outgoing packets, pkt->length represents the length of the
1220 * whole packet starting at pkt->data (including some header), and
1221 * pkt->body refers to the point within that where the log-worthy
1222 * payload begins. However, incoming packets expect pkt->length to
1223 * represent only the payload length (that is, it's measured from
1224 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1225 * packet to conform to the incoming-packet semantics, so that we
1226 * can analyse it with the ssh_pkt_get functions.
1228 pkt->length -= (pkt->body - pkt->data);
1231 if (ssh->logomitdata &&
1232 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1233 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1234 /* "Session data" packets - omit the data string. */
1235 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1236 ssh_pkt_getuint32(pkt); /* skip channel id */
1237 blanks[nblanks].offset = pkt->savedpos + 4;
1238 blanks[nblanks].type = PKTLOG_OMIT;
1239 ssh_pkt_getstring(pkt, &str, &slen);
1241 blanks[nblanks].len = slen;
1246 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1247 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1248 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1249 conf_get_int(ssh->conf, CONF_logomitpass)) {
1250 /* If this is a password or similar packet, blank the password(s). */
1251 blanks[nblanks].offset = 0;
1252 blanks[nblanks].len = pkt->length;
1253 blanks[nblanks].type = PKTLOG_BLANK;
1255 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1256 conf_get_int(ssh->conf, CONF_logomitpass)) {
1258 * If this is an X forwarding request packet, blank the fake
1261 * Note that while we blank the X authentication data here, we
1262 * don't take any special action to blank the start of an X11
1263 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1264 * an X connection without having session blanking enabled is
1265 * likely to leak your cookie into the log.
1268 ssh_pkt_getstring(pkt, &str, &slen);
1269 blanks[nblanks].offset = pkt->savedpos;
1270 blanks[nblanks].type = PKTLOG_BLANK;
1271 ssh_pkt_getstring(pkt, &str, &slen);
1273 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1278 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1279 ssh1_pkt_type(pkt->data[12]),
1280 pkt->body, pkt->length,
1281 nblanks, blanks, NULL, 0, NULL);
1284 * Undo the above adjustment of pkt->length, to put the packet
1285 * back in the state we found it.
1287 pkt->length += (pkt->body - pkt->data);
1291 * Collect incoming data in the incoming packet buffer.
1292 * Decipher and verify the packet when it is completely read.
1293 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1294 * Update the *data and *datalen variables.
1295 * Return a Packet structure when a packet is completed.
1297 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1299 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1301 crBegin(ssh->ssh1_rdpkt_crstate);
1303 st->pktin = ssh_new_packet();
1305 st->pktin->type = 0;
1306 st->pktin->length = 0;
1308 for (st->i = st->len = 0; st->i < 4; st->i++) {
1309 while ((*datalen) == 0)
1311 st->len = (st->len << 8) + **data;
1312 (*data)++, (*datalen)--;
1315 st->pad = 8 - (st->len % 8);
1316 st->biglen = st->len + st->pad;
1317 st->pktin->length = st->len - 5;
1319 if (st->biglen < 0) {
1320 bombout(("Extremely large packet length from server suggests"
1321 " data stream corruption"));
1322 ssh_free_packet(st->pktin);
1326 st->pktin->maxlen = st->biglen;
1327 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1329 st->to_read = st->biglen;
1330 st->p = st->pktin->data;
1331 while (st->to_read > 0) {
1332 st->chunk = st->to_read;
1333 while ((*datalen) == 0)
1335 if (st->chunk > (*datalen))
1336 st->chunk = (*datalen);
1337 memcpy(st->p, *data, st->chunk);
1339 *datalen -= st->chunk;
1341 st->to_read -= st->chunk;
1344 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1345 st->biglen, NULL)) {
1346 bombout(("Network attack (CRC compensation) detected!"));
1347 ssh_free_packet(st->pktin);
1352 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1354 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1355 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1356 if (st->gotcrc != st->realcrc) {
1357 bombout(("Incorrect CRC received on packet"));
1358 ssh_free_packet(st->pktin);
1362 st->pktin->body = st->pktin->data + st->pad + 1;
1364 if (ssh->v1_compressing) {
1365 unsigned char *decompblk;
1367 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1368 st->pktin->body - 1, st->pktin->length + 1,
1369 &decompblk, &decomplen)) {
1370 bombout(("Zlib decompression encountered invalid data"));
1371 ssh_free_packet(st->pktin);
1375 if (st->pktin->maxlen < st->pad + decomplen) {
1376 st->pktin->maxlen = st->pad + decomplen;
1377 st->pktin->data = sresize(st->pktin->data,
1378 st->pktin->maxlen + APIEXTRA,
1380 st->pktin->body = st->pktin->data + st->pad + 1;
1383 memcpy(st->pktin->body - 1, decompblk, decomplen);
1385 st->pktin->length = decomplen - 1;
1388 st->pktin->type = st->pktin->body[-1];
1391 * Now pktin->body and pktin->length identify the semantic content
1392 * of the packet, excluding the initial type byte.
1396 ssh1_log_incoming_packet(ssh, st->pktin);
1398 st->pktin->savedpos = 0;
1400 crFinish(st->pktin);
1403 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1406 struct logblank_t blanks[4];
1412 if (ssh->logomitdata &&
1413 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1414 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1415 /* "Session data" packets - omit the data string. */
1416 ssh_pkt_getuint32(pkt); /* skip channel id */
1417 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1418 ssh_pkt_getuint32(pkt); /* skip extended data type */
1419 blanks[nblanks].offset = pkt->savedpos + 4;
1420 blanks[nblanks].type = PKTLOG_OMIT;
1421 ssh_pkt_getstring(pkt, &str, &slen);
1423 blanks[nblanks].len = slen;
1428 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1429 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1430 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1434 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1437 struct logblank_t blanks[4];
1442 * For outgoing packets, pkt->length represents the length of the
1443 * whole packet starting at pkt->data (including some header), and
1444 * pkt->body refers to the point within that where the log-worthy
1445 * payload begins. However, incoming packets expect pkt->length to
1446 * represent only the payload length (that is, it's measured from
1447 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1448 * packet to conform to the incoming-packet semantics, so that we
1449 * can analyse it with the ssh_pkt_get functions.
1451 pkt->length -= (pkt->body - pkt->data);
1454 if (ssh->logomitdata &&
1455 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1456 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1457 /* "Session data" packets - omit the data string. */
1458 ssh_pkt_getuint32(pkt); /* skip channel id */
1459 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1460 ssh_pkt_getuint32(pkt); /* skip extended data type */
1461 blanks[nblanks].offset = pkt->savedpos + 4;
1462 blanks[nblanks].type = PKTLOG_OMIT;
1463 ssh_pkt_getstring(pkt, &str, &slen);
1465 blanks[nblanks].len = slen;
1470 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1471 conf_get_int(ssh->conf, CONF_logomitpass)) {
1472 /* If this is a password packet, blank the password(s). */
1474 ssh_pkt_getstring(pkt, &str, &slen);
1475 ssh_pkt_getstring(pkt, &str, &slen);
1476 ssh_pkt_getstring(pkt, &str, &slen);
1477 if (slen == 8 && !memcmp(str, "password", 8)) {
1478 ssh2_pkt_getbool(pkt);
1479 /* Blank the password field. */
1480 blanks[nblanks].offset = pkt->savedpos;
1481 blanks[nblanks].type = PKTLOG_BLANK;
1482 ssh_pkt_getstring(pkt, &str, &slen);
1484 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1486 /* If there's another password field beyond it (change of
1487 * password), blank that too. */
1488 ssh_pkt_getstring(pkt, &str, &slen);
1490 blanks[nblanks-1].len =
1491 pkt->savedpos - blanks[nblanks].offset;
1494 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1495 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1496 conf_get_int(ssh->conf, CONF_logomitpass)) {
1497 /* If this is a keyboard-interactive response packet, blank
1500 ssh_pkt_getuint32(pkt);
1501 blanks[nblanks].offset = pkt->savedpos;
1502 blanks[nblanks].type = PKTLOG_BLANK;
1504 ssh_pkt_getstring(pkt, &str, &slen);
1508 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1510 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1511 conf_get_int(ssh->conf, CONF_logomitpass)) {
1513 * If this is an X forwarding request packet, blank the fake
1516 * Note that while we blank the X authentication data here, we
1517 * don't take any special action to blank the start of an X11
1518 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1519 * an X connection without having session blanking enabled is
1520 * likely to leak your cookie into the log.
1523 ssh_pkt_getuint32(pkt);
1524 ssh_pkt_getstring(pkt, &str, &slen);
1525 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1526 ssh2_pkt_getbool(pkt);
1527 ssh2_pkt_getbool(pkt);
1528 ssh_pkt_getstring(pkt, &str, &slen);
1529 blanks[nblanks].offset = pkt->savedpos;
1530 blanks[nblanks].type = PKTLOG_BLANK;
1531 ssh_pkt_getstring(pkt, &str, &slen);
1533 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1539 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1540 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1541 pkt->body, pkt->length, nblanks, blanks,
1542 &ssh->v2_outgoing_sequence,
1543 pkt->downstream_id, pkt->additional_log_text);
1546 * Undo the above adjustment of pkt->length, to put the packet
1547 * back in the state we found it.
1549 pkt->length += (pkt->body - pkt->data);
1552 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1554 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1556 crBegin(ssh->ssh2_rdpkt_crstate);
1558 st->pktin = ssh_new_packet();
1560 st->pktin->type = 0;
1561 st->pktin->length = 0;
1563 st->cipherblk = ssh->sccipher->blksize;
1566 if (st->cipherblk < 8)
1568 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1570 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1571 ssh->scmac && !ssh->scmac_etm) {
1573 * When dealing with a CBC-mode cipher, we want to avoid the
1574 * possibility of an attacker's tweaking the ciphertext stream
1575 * so as to cause us to feed the same block to the block
1576 * cipher more than once and thus leak information
1577 * (VU#958563). The way we do this is not to take any
1578 * decisions on the basis of anything we've decrypted until
1579 * we've verified it with a MAC. That includes the packet
1580 * length, so we just read data and check the MAC repeatedly,
1581 * and when the MAC passes, see if the length we've got is
1584 * This defence is unnecessary in OpenSSH ETM mode, because
1585 * the whole point of ETM mode is that the attacker can't
1586 * tweak the ciphertext stream at all without the MAC
1587 * detecting it before we decrypt anything.
1590 /* May as well allocate the whole lot now. */
1591 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1594 /* Read an amount corresponding to the MAC. */
1595 for (st->i = 0; st->i < st->maclen; st->i++) {
1596 while ((*datalen) == 0)
1598 st->pktin->data[st->i] = *(*data)++;
1604 unsigned char seq[4];
1605 ssh->scmac->start(ssh->sc_mac_ctx);
1606 PUT_32BIT(seq, st->incoming_sequence);
1607 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1610 for (;;) { /* Once around this loop per cipher block. */
1611 /* Read another cipher-block's worth, and tack it onto the end. */
1612 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1613 while ((*datalen) == 0)
1615 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1618 /* Decrypt one more block (a little further back in the stream). */
1619 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1620 st->pktin->data + st->packetlen,
1622 /* Feed that block to the MAC. */
1623 ssh->scmac->bytes(ssh->sc_mac_ctx,
1624 st->pktin->data + st->packetlen, st->cipherblk);
1625 st->packetlen += st->cipherblk;
1626 /* See if that gives us a valid packet. */
1627 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1628 st->pktin->data + st->packetlen) &&
1629 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1632 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1633 bombout(("No valid incoming packet found"));
1634 ssh_free_packet(st->pktin);
1638 st->pktin->maxlen = st->packetlen + st->maclen;
1639 st->pktin->data = sresize(st->pktin->data,
1640 st->pktin->maxlen + APIEXTRA,
1642 } else if (ssh->scmac && ssh->scmac_etm) {
1643 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1646 * OpenSSH encrypt-then-MAC mode: the packet length is
1649 for (st->i = st->len = 0; st->i < 4; st->i++) {
1650 while ((*datalen) == 0)
1652 st->pktin->data[st->i] = *(*data)++;
1655 st->len = toint(GET_32BIT(st->pktin->data));
1658 * _Completely_ silly lengths should be stomped on before they
1659 * do us any more damage.
1661 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1662 st->len % st->cipherblk != 0) {
1663 bombout(("Incoming packet length field was garbled"));
1664 ssh_free_packet(st->pktin);
1669 * So now we can work out the total packet length.
1671 st->packetlen = st->len + 4;
1674 * Allocate memory for the rest of the packet.
1676 st->pktin->maxlen = st->packetlen + st->maclen;
1677 st->pktin->data = sresize(st->pktin->data,
1678 st->pktin->maxlen + APIEXTRA,
1682 * Read the remainder of the packet.
1684 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1685 while ((*datalen) == 0)
1687 st->pktin->data[st->i] = *(*data)++;
1695 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1696 st->len + 4, st->incoming_sequence)) {
1697 bombout(("Incorrect MAC received on packet"));
1698 ssh_free_packet(st->pktin);
1702 /* Decrypt everything between the length field and the MAC. */
1704 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1705 st->pktin->data + 4,
1708 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1711 * Acquire and decrypt the first block of the packet. This will
1712 * contain the length and padding details.
1714 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1715 while ((*datalen) == 0)
1717 st->pktin->data[st->i] = *(*data)++;
1722 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1723 st->pktin->data, st->cipherblk);
1726 * Now get the length figure.
1728 st->len = toint(GET_32BIT(st->pktin->data));
1731 * _Completely_ silly lengths should be stomped on before they
1732 * do us any more damage.
1734 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1735 (st->len + 4) % st->cipherblk != 0) {
1736 bombout(("Incoming packet was garbled on decryption"));
1737 ssh_free_packet(st->pktin);
1742 * So now we can work out the total packet length.
1744 st->packetlen = st->len + 4;
1747 * Allocate memory for the rest of the packet.
1749 st->pktin->maxlen = st->packetlen + st->maclen;
1750 st->pktin->data = sresize(st->pktin->data,
1751 st->pktin->maxlen + APIEXTRA,
1755 * Read and decrypt the remainder of the packet.
1757 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1759 while ((*datalen) == 0)
1761 st->pktin->data[st->i] = *(*data)++;
1764 /* Decrypt everything _except_ the MAC. */
1766 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1767 st->pktin->data + st->cipherblk,
1768 st->packetlen - st->cipherblk);
1774 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1775 st->len + 4, st->incoming_sequence)) {
1776 bombout(("Incorrect MAC received on packet"));
1777 ssh_free_packet(st->pktin);
1781 /* Get and sanity-check the amount of random padding. */
1782 st->pad = st->pktin->data[4];
1783 if (st->pad < 4 || st->len - st->pad < 1) {
1784 bombout(("Invalid padding length on received packet"));
1785 ssh_free_packet(st->pktin);
1789 * This enables us to deduce the payload length.
1791 st->payload = st->len - st->pad - 1;
1793 st->pktin->length = st->payload + 5;
1794 st->pktin->encrypted_len = st->packetlen;
1796 st->pktin->sequence = st->incoming_sequence++;
1798 st->pktin->length = st->packetlen - st->pad;
1799 assert(st->pktin->length >= 0);
1802 * Decompress packet payload.
1805 unsigned char *newpayload;
1808 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1809 st->pktin->data + 5, st->pktin->length - 5,
1810 &newpayload, &newlen)) {
1811 if (st->pktin->maxlen < newlen + 5) {
1812 st->pktin->maxlen = newlen + 5;
1813 st->pktin->data = sresize(st->pktin->data,
1814 st->pktin->maxlen + APIEXTRA,
1817 st->pktin->length = 5 + newlen;
1818 memcpy(st->pktin->data + 5, newpayload, newlen);
1824 * pktin->body and pktin->length should identify the semantic
1825 * content of the packet, excluding the initial type byte.
1827 st->pktin->type = st->pktin->data[5];
1828 st->pktin->body = st->pktin->data + 6;
1829 st->pktin->length -= 6;
1830 assert(st->pktin->length >= 0); /* one last double-check */
1833 ssh2_log_incoming_packet(ssh, st->pktin);
1835 st->pktin->savedpos = 0;
1837 crFinish(st->pktin);
1840 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1843 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1845 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1848 * Read the packet length field.
1850 for (st->i = 0; st->i < 4; st->i++) {
1851 while ((*datalen) == 0)
1853 st->length[st->i] = *(*data)++;
1857 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1858 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1859 bombout(("Invalid packet length received"));
1863 st->pktin = ssh_new_packet();
1864 st->pktin->data = snewn(st->packetlen, unsigned char);
1866 st->pktin->encrypted_len = st->packetlen;
1868 st->pktin->sequence = st->incoming_sequence++;
1871 * Read the remainder of the packet.
1873 for (st->i = 0; st->i < st->packetlen; st->i++) {
1874 while ((*datalen) == 0)
1876 st->pktin->data[st->i] = *(*data)++;
1881 * pktin->body and pktin->length should identify the semantic
1882 * content of the packet, excluding the initial type byte.
1884 st->pktin->type = st->pktin->data[0];
1885 st->pktin->body = st->pktin->data + 1;
1886 st->pktin->length = st->packetlen - 1;
1889 * Log incoming packet, possibly omitting sensitive fields.
1892 ssh2_log_incoming_packet(ssh, st->pktin);
1894 st->pktin->savedpos = 0;
1896 crFinish(st->pktin);
1899 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1901 int pad, biglen, i, pktoffs;
1905 * XXX various versions of SC (including 8.8.4) screw up the
1906 * register allocation in this function and use the same register
1907 * (D6) for len and as a temporary, with predictable results. The
1908 * following sledgehammer prevents this.
1915 ssh1_log_outgoing_packet(ssh, pkt);
1917 if (ssh->v1_compressing) {
1918 unsigned char *compblk;
1920 zlib_compress_block(ssh->cs_comp_ctx,
1921 pkt->data + 12, pkt->length - 12,
1922 &compblk, &complen);
1923 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1924 memcpy(pkt->data + 12, compblk, complen);
1926 pkt->length = complen + 12;
1929 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1931 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1932 pad = 8 - (len % 8);
1934 biglen = len + pad; /* len(padding+type+data+CRC) */
1936 for (i = pktoffs; i < 4+8; i++)
1937 pkt->data[i] = random_byte();
1938 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1939 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1940 PUT_32BIT(pkt->data + pktoffs, len);
1943 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1944 pkt->data + pktoffs + 4, biglen);
1946 if (offset_p) *offset_p = pktoffs;
1947 return biglen + 4; /* len(length+padding+type+data+CRC) */
1950 static int s_write(Ssh ssh, void *data, int len)
1953 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1954 0, NULL, NULL, 0, NULL);
1957 return sk_write(ssh->s, (char *)data, len);
1960 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1962 int len, backlog, offset;
1963 len = s_wrpkt_prepare(ssh, pkt, &offset);
1964 backlog = s_write(ssh, pkt->data + offset, len);
1965 if (backlog > SSH_MAX_BACKLOG)
1966 ssh_throttle_all(ssh, 1, backlog);
1967 ssh_free_packet(pkt);
1970 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1973 len = s_wrpkt_prepare(ssh, pkt, &offset);
1974 if (ssh->deferred_len + len > ssh->deferred_size) {
1975 ssh->deferred_size = ssh->deferred_len + len + 128;
1976 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1980 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1981 pkt->data + offset, len);
1982 ssh->deferred_len += len;
1983 ssh_free_packet(pkt);
1987 * Construct a SSH-1 packet with the specified contents.
1988 * (This all-at-once interface used to be the only one, but now SSH-1
1989 * packets can also be constructed incrementally.)
1991 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1997 pkt = ssh1_pkt_init(pkttype);
1999 while ((argtype = va_arg(ap, int)) != PKT_END) {
2000 unsigned char *argp, argchar;
2002 unsigned long argint;
2005 /* Actual fields in the packet */
2007 argint = va_arg(ap, int);
2008 ssh_pkt_adduint32(pkt, argint);
2011 argchar = (unsigned char) va_arg(ap, int);
2012 ssh_pkt_addbyte(pkt, argchar);
2015 argp = va_arg(ap, unsigned char *);
2016 arglen = va_arg(ap, int);
2017 ssh_pkt_adddata(pkt, argp, arglen);
2020 sargp = va_arg(ap, char *);
2021 ssh_pkt_addstring(pkt, sargp);
2024 bn = va_arg(ap, Bignum);
2025 ssh1_pkt_addmp(pkt, bn);
2033 static void send_packet(Ssh ssh, int pkttype, ...)
2037 va_start(ap, pkttype);
2038 pkt = construct_packet(ssh, pkttype, ap);
2043 static void defer_packet(Ssh ssh, int pkttype, ...)
2047 va_start(ap, pkttype);
2048 pkt = construct_packet(ssh, pkttype, ap);
2050 s_wrpkt_defer(ssh, pkt);
2053 static int ssh_versioncmp(char *a, char *b)
2056 unsigned long av, bv;
2058 av = strtoul(a, &ae, 10);
2059 bv = strtoul(b, &be, 10);
2061 return (av < bv ? -1 : +1);
2066 av = strtoul(ae, &ae, 10);
2067 bv = strtoul(be, &be, 10);
2069 return (av < bv ? -1 : +1);
2074 * Utility routines for putting an SSH-protocol `string' and
2075 * `uint32' into a hash state.
2077 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2079 unsigned char lenblk[4];
2080 PUT_32BIT(lenblk, len);
2081 h->bytes(s, lenblk, 4);
2082 h->bytes(s, str, len);
2085 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2087 unsigned char intblk[4];
2088 PUT_32BIT(intblk, i);
2089 h->bytes(s, intblk, 4);
2093 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2095 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2097 if (pkt->maxlen < length) {
2098 unsigned char *body = pkt->body;
2099 int offset = body ? body - pkt->data : 0;
2100 pkt->maxlen = length + 256;
2101 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2102 if (body) pkt->body = pkt->data + offset;
2105 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2108 ssh_pkt_ensure(pkt, pkt->length);
2109 memcpy(pkt->data + pkt->length - len, data, len);
2111 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2113 ssh_pkt_adddata(pkt, &byte, 1);
2115 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2117 ssh_pkt_adddata(pkt, &value, 1);
2119 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2122 PUT_32BIT(x, value);
2123 ssh_pkt_adddata(pkt, x, 4);
2125 static void ssh_pkt_addstring_start(struct Packet *pkt)
2127 ssh_pkt_adduint32(pkt, 0);
2128 pkt->savedpos = pkt->length;
2130 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2133 ssh_pkt_adddata(pkt, data, len);
2134 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2136 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2138 ssh_pkt_addstring_data(pkt, data, strlen(data));
2140 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2142 ssh_pkt_addstring_start(pkt);
2143 ssh_pkt_addstring_str(pkt, data);
2145 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2147 int len = ssh1_bignum_length(b);
2148 unsigned char *data = snewn(len, unsigned char);
2149 (void) ssh1_write_bignum(data, b);
2150 ssh_pkt_adddata(pkt, data, len);
2153 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2156 int i, n = (bignum_bitcount(b) + 7) / 8;
2157 p = snewn(n + 1, unsigned char);
2159 for (i = 1; i <= n; i++)
2160 p[i] = bignum_byte(b, n - i);
2162 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2164 memmove(p, p + i, n + 1 - i);
2168 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2172 p = ssh2_mpint_fmt(b, &len);
2173 ssh_pkt_addstring_start(pkt);
2174 ssh_pkt_addstring_data(pkt, (char *)p, len);
2178 static struct Packet *ssh1_pkt_init(int pkt_type)
2180 struct Packet *pkt = ssh_new_packet();
2181 pkt->length = 4 + 8; /* space for length + max padding */
2182 ssh_pkt_addbyte(pkt, pkt_type);
2183 pkt->body = pkt->data + pkt->length;
2184 pkt->type = pkt_type;
2185 pkt->downstream_id = 0;
2186 pkt->additional_log_text = NULL;
2190 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2191 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2192 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2193 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2194 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2195 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2196 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2197 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2198 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2200 static struct Packet *ssh2_pkt_init(int pkt_type)
2202 struct Packet *pkt = ssh_new_packet();
2203 pkt->length = 5; /* space for packet length + padding length */
2205 pkt->type = pkt_type;
2206 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2207 pkt->body = pkt->data + pkt->length; /* after packet type */
2208 pkt->downstream_id = 0;
2209 pkt->additional_log_text = NULL;
2214 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2215 * put the MAC on it. Final packet, ready to be sent, is stored in
2216 * pkt->data. Total length is returned.
2218 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2220 int cipherblk, maclen, padding, unencrypted_prefix, i;
2223 ssh2_log_outgoing_packet(ssh, pkt);
2225 if (ssh->bare_connection) {
2227 * Trivial packet construction for the bare connection
2230 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2231 pkt->body = pkt->data + 1;
2232 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2233 return pkt->length - 1;
2237 * Compress packet payload.
2240 unsigned char *newpayload;
2243 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2245 &newpayload, &newlen)) {
2247 ssh2_pkt_adddata(pkt, newpayload, newlen);
2253 * Add padding. At least four bytes, and must also bring total
2254 * length (minus MAC) up to a multiple of the block size.
2255 * If pkt->forcepad is set, make sure the packet is at least that size
2258 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2259 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2261 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2262 if (pkt->length + padding < pkt->forcepad)
2263 padding = pkt->forcepad - pkt->length;
2265 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2267 assert(padding <= 255);
2268 maclen = ssh->csmac ? ssh->csmac->len : 0;
2269 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2270 pkt->data[4] = padding;
2271 for (i = 0; i < padding; i++)
2272 pkt->data[pkt->length + i] = random_byte();
2273 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2274 if (ssh->csmac && ssh->csmac_etm) {
2276 * OpenSSH-defined encrypt-then-MAC protocol.
2279 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2280 pkt->data + 4, pkt->length + padding - 4);
2281 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2282 pkt->length + padding,
2283 ssh->v2_outgoing_sequence);
2286 * SSH-2 standard protocol.
2289 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2290 pkt->length + padding,
2291 ssh->v2_outgoing_sequence);
2293 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2294 pkt->data, pkt->length + padding);
2297 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2298 pkt->encrypted_len = pkt->length + padding;
2300 /* Ready-to-send packet starts at pkt->data. We return length. */
2301 pkt->body = pkt->data;
2302 return pkt->length + padding + maclen;
2306 * Routines called from the main SSH code to send packets. There
2307 * are quite a few of these, because we have two separate
2308 * mechanisms for delaying the sending of packets:
2310 * - In order to send an IGNORE message and a password message in
2311 * a single fixed-length blob, we require the ability to
2312 * concatenate the encrypted forms of those two packets _into_ a
2313 * single blob and then pass it to our <network.h> transport
2314 * layer in one go. Hence, there's a deferment mechanism which
2315 * works after packet encryption.
2317 * - In order to avoid sending any connection-layer messages
2318 * during repeat key exchange, we have to queue up any such
2319 * outgoing messages _before_ they are encrypted (and in
2320 * particular before they're allocated sequence numbers), and
2321 * then send them once we've finished.
2323 * I call these mechanisms `defer' and `queue' respectively, so as
2324 * to distinguish them reasonably easily.
2326 * The functions send_noqueue() and defer_noqueue() free the packet
2327 * structure they are passed. Every outgoing packet goes through
2328 * precisely one of these functions in its life; packets passed to
2329 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2330 * these or get queued, and then when the queue is later emptied
2331 * the packets are all passed to defer_noqueue().
2333 * When using a CBC-mode cipher, it's necessary to ensure that an
2334 * attacker can't provide data to be encrypted using an IV that they
2335 * know. We ensure this by prefixing each packet that might contain
2336 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2337 * mechanism, so in this case send_noqueue() ends up redirecting to
2338 * defer_noqueue(). If you don't like this inefficiency, don't use
2342 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2343 static void ssh_pkt_defersend(Ssh);
2346 * Send an SSH-2 packet immediately, without queuing or deferring.
2348 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2352 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2353 /* We need to send two packets, so use the deferral mechanism. */
2354 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2355 ssh_pkt_defersend(ssh);
2358 len = ssh2_pkt_construct(ssh, pkt);
2359 backlog = s_write(ssh, pkt->body, len);
2360 if (backlog > SSH_MAX_BACKLOG)
2361 ssh_throttle_all(ssh, 1, backlog);
2363 ssh->outgoing_data_size += pkt->encrypted_len;
2364 if (!ssh->kex_in_progress &&
2365 !ssh->bare_connection &&
2366 ssh->max_data_size != 0 &&
2367 ssh->outgoing_data_size > ssh->max_data_size)
2368 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2370 ssh_free_packet(pkt);
2374 * Defer an SSH-2 packet.
2376 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2379 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2380 ssh->deferred_len == 0 && !noignore &&
2381 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2383 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2384 * get encrypted with a known IV.
2386 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2387 ssh2_pkt_addstring_start(ipkt);
2388 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2390 len = ssh2_pkt_construct(ssh, pkt);
2391 if (ssh->deferred_len + len > ssh->deferred_size) {
2392 ssh->deferred_size = ssh->deferred_len + len + 128;
2393 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2397 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2398 ssh->deferred_len += len;
2399 ssh->deferred_data_size += pkt->encrypted_len;
2400 ssh_free_packet(pkt);
2404 * Queue an SSH-2 packet.
2406 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2408 assert(ssh->queueing);
2410 if (ssh->queuelen >= ssh->queuesize) {
2411 ssh->queuesize = ssh->queuelen + 32;
2412 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2415 ssh->queue[ssh->queuelen++] = pkt;
2419 * Either queue or send a packet, depending on whether queueing is
2422 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2425 ssh2_pkt_queue(ssh, pkt);
2427 ssh2_pkt_send_noqueue(ssh, pkt);
2431 * Either queue or defer a packet, depending on whether queueing is
2434 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2437 ssh2_pkt_queue(ssh, pkt);
2439 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2443 * Send the whole deferred data block constructed by
2444 * ssh2_pkt_defer() or SSH-1's defer_packet().
2446 * The expected use of the defer mechanism is that you call
2447 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2448 * not currently queueing, this simply sets up deferred_send_data
2449 * and then sends it. If we _are_ currently queueing, the calls to
2450 * ssh2_pkt_defer() put the deferred packets on to the queue
2451 * instead, and therefore ssh_pkt_defersend() has no deferred data
2452 * to send. Hence, there's no need to make it conditional on
2455 static void ssh_pkt_defersend(Ssh ssh)
2458 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2459 ssh->deferred_len = ssh->deferred_size = 0;
2460 sfree(ssh->deferred_send_data);
2461 ssh->deferred_send_data = NULL;
2462 if (backlog > SSH_MAX_BACKLOG)
2463 ssh_throttle_all(ssh, 1, backlog);
2465 ssh->outgoing_data_size += ssh->deferred_data_size;
2466 if (!ssh->kex_in_progress &&
2467 !ssh->bare_connection &&
2468 ssh->max_data_size != 0 &&
2469 ssh->outgoing_data_size > ssh->max_data_size)
2470 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2471 ssh->deferred_data_size = 0;
2475 * Send a packet whose length needs to be disguised (typically
2476 * passwords or keyboard-interactive responses).
2478 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2484 * The simplest way to do this is to adjust the
2485 * variable-length padding field in the outgoing packet.
2487 * Currently compiled out, because some Cisco SSH servers
2488 * don't like excessively padded packets (bah, why's it
2491 pkt->forcepad = padsize;
2492 ssh2_pkt_send(ssh, pkt);
2497 * If we can't do that, however, an alternative approach is
2498 * to use the pkt_defer mechanism to bundle the packet
2499 * tightly together with an SSH_MSG_IGNORE such that their
2500 * combined length is a constant. So first we construct the
2501 * final form of this packet and defer its sending.
2503 ssh2_pkt_defer(ssh, pkt);
2506 * Now construct an SSH_MSG_IGNORE which includes a string
2507 * that's an exact multiple of the cipher block size. (If
2508 * the cipher is NULL so that the block size is
2509 * unavailable, we don't do this trick at all, because we
2510 * gain nothing by it.)
2512 if (ssh->cscipher &&
2513 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2516 stringlen = (256 - ssh->deferred_len);
2517 stringlen += ssh->cscipher->blksize - 1;
2518 stringlen -= (stringlen % ssh->cscipher->blksize);
2521 * Temporarily disable actual compression, so we
2522 * can guarantee to get this string exactly the
2523 * length we want it. The compression-disabling
2524 * routine should return an integer indicating how
2525 * many bytes we should adjust our string length
2529 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2531 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2532 ssh2_pkt_addstring_start(pkt);
2533 for (i = 0; i < stringlen; i++) {
2534 char c = (char) random_byte();
2535 ssh2_pkt_addstring_data(pkt, &c, 1);
2537 ssh2_pkt_defer(ssh, pkt);
2539 ssh_pkt_defersend(ssh);
2544 * Send all queued SSH-2 packets. We send them by means of
2545 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2546 * packets that needed to be lumped together.
2548 static void ssh2_pkt_queuesend(Ssh ssh)
2552 assert(!ssh->queueing);
2554 for (i = 0; i < ssh->queuelen; i++)
2555 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2558 ssh_pkt_defersend(ssh);
2562 void bndebug(char *string, Bignum b)
2566 p = ssh2_mpint_fmt(b, &len);
2567 debug(("%s", string));
2568 for (i = 0; i < len; i++)
2569 debug((" %02x", p[i]));
2575 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2579 p = ssh2_mpint_fmt(b, &len);
2580 hash_string(h, s, p, len);
2585 * Packet decode functions for both SSH-1 and SSH-2.
2587 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2589 unsigned long value;
2590 if (pkt->length - pkt->savedpos < 4)
2591 return 0; /* arrgh, no way to decline (FIXME?) */
2592 value = GET_32BIT(pkt->body + pkt->savedpos);
2596 static int ssh2_pkt_getbool(struct Packet *pkt)
2598 unsigned long value;
2599 if (pkt->length - pkt->savedpos < 1)
2600 return 0; /* arrgh, no way to decline (FIXME?) */
2601 value = pkt->body[pkt->savedpos] != 0;
2605 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2610 if (pkt->length - pkt->savedpos < 4)
2612 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2617 if (pkt->length - pkt->savedpos < *length)
2619 *p = (char *)(pkt->body + pkt->savedpos);
2620 pkt->savedpos += *length;
2622 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2624 if (pkt->length - pkt->savedpos < length)
2626 pkt->savedpos += length;
2627 return pkt->body + (pkt->savedpos - length);
2629 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2630 const unsigned char **keystr)
2634 j = makekey(pkt->body + pkt->savedpos,
2635 pkt->length - pkt->savedpos,
2642 assert(pkt->savedpos < pkt->length);
2646 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2651 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2652 pkt->length - pkt->savedpos, &b);
2660 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2666 ssh_pkt_getstring(pkt, &p, &length);
2671 b = bignum_from_bytes((unsigned char *)p, length);
2676 * Helper function to add an SSH-2 signature blob to a packet.
2677 * Expects to be shown the public key blob as well as the signature
2678 * blob. Normally works just like ssh2_pkt_addstring, but will
2679 * fiddle with the signature packet if necessary for
2680 * BUG_SSH2_RSA_PADDING.
2682 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2683 void *pkblob_v, int pkblob_len,
2684 void *sigblob_v, int sigblob_len)
2686 unsigned char *pkblob = (unsigned char *)pkblob_v;
2687 unsigned char *sigblob = (unsigned char *)sigblob_v;
2689 /* dmemdump(pkblob, pkblob_len); */
2690 /* dmemdump(sigblob, sigblob_len); */
2693 * See if this is in fact an ssh-rsa signature and a buggy
2694 * server; otherwise we can just do this the easy way.
2696 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2697 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2698 int pos, len, siglen;
2701 * Find the byte length of the modulus.
2704 pos = 4+7; /* skip over "ssh-rsa" */
2705 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2706 if (len < 0 || len > pkblob_len - pos - 4)
2708 pos += 4 + len; /* skip over exponent */
2709 if (pkblob_len - pos < 4)
2711 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2712 if (len < 0 || len > pkblob_len - pos - 4)
2714 pos += 4; /* find modulus itself */
2715 while (len > 0 && pkblob[pos] == 0)
2717 /* debug(("modulus length is %d\n", len)); */
2720 * Now find the signature integer.
2722 pos = 4+7; /* skip over "ssh-rsa" */
2723 if (sigblob_len < pos+4)
2725 siglen = toint(GET_32BIT(sigblob+pos));
2726 if (siglen != sigblob_len - pos - 4)
2728 /* debug(("signature length is %d\n", siglen)); */
2730 if (len != siglen) {
2731 unsigned char newlen[4];
2732 ssh2_pkt_addstring_start(pkt);
2733 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2734 /* dmemdump(sigblob, pos); */
2735 pos += 4; /* point to start of actual sig */
2736 PUT_32BIT(newlen, len);
2737 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2738 /* dmemdump(newlen, 4); */
2740 while (len-- > siglen) {
2741 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2742 /* dmemdump(newlen, 1); */
2744 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2745 /* dmemdump(sigblob+pos, siglen); */
2749 /* Otherwise fall through and do it the easy way. We also come
2750 * here as a fallback if we discover above that the key blob
2751 * is misformatted in some way. */
2755 ssh2_pkt_addstring_start(pkt);
2756 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2760 * Examine the remote side's version string and compare it against
2761 * a list of known buggy implementations.
2763 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2765 char *imp; /* pointer to implementation part */
2767 imp += strcspn(imp, "-");
2769 imp += strcspn(imp, "-");
2772 ssh->remote_bugs = 0;
2775 * General notes on server version strings:
2776 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2777 * here -- in particular, we've heard of one that's perfectly happy
2778 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2779 * so we can't distinguish them.
2781 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2782 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2783 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2784 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2785 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2786 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2788 * These versions don't support SSH1_MSG_IGNORE, so we have
2789 * to use a different defence against password length
2792 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2793 logevent("We believe remote version has SSH-1 ignore bug");
2796 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2797 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2798 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2800 * These versions need a plain password sent; they can't
2801 * handle having a null and a random length of data after
2804 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2805 logevent("We believe remote version needs a plain SSH-1 password");
2808 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2809 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2810 (!strcmp(imp, "Cisco-1.25")))) {
2812 * These versions apparently have no clue whatever about
2813 * RSA authentication and will panic and die if they see
2814 * an AUTH_RSA message.
2816 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2817 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2820 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2821 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2822 !wc_match("* VShell", imp) &&
2823 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2824 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2825 wc_match("2.1 *", imp)))) {
2827 * These versions have the HMAC bug.
2829 ssh->remote_bugs |= BUG_SSH2_HMAC;
2830 logevent("We believe remote version has SSH-2 HMAC bug");
2833 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2834 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2835 !wc_match("* VShell", imp) &&
2836 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2838 * These versions have the key-derivation bug (failing to
2839 * include the literal shared secret in the hashes that
2840 * generate the keys).
2842 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2843 logevent("We believe remote version has SSH-2 key-derivation bug");
2846 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2847 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2848 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2849 wc_match("OpenSSH_3.[0-2]*", imp) ||
2850 wc_match("mod_sftp/0.[0-8]*", imp) ||
2851 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2853 * These versions have the SSH-2 RSA padding bug.
2855 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2856 logevent("We believe remote version has SSH-2 RSA padding bug");
2859 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2860 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2861 wc_match("OpenSSH_2.[0-2]*", imp))) {
2863 * These versions have the SSH-2 session-ID bug in
2864 * public-key authentication.
2866 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2867 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2870 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2871 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2872 (wc_match("DigiSSH_2.0", imp) ||
2873 wc_match("OpenSSH_2.[0-4]*", imp) ||
2874 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2875 wc_match("Sun_SSH_1.0", imp) ||
2876 wc_match("Sun_SSH_1.0.1", imp) ||
2877 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2878 wc_match("WeOnlyDo-*", imp)))) {
2880 * These versions have the SSH-2 rekey bug.
2882 ssh->remote_bugs |= BUG_SSH2_REKEY;
2883 logevent("We believe remote version has SSH-2 rekey bug");
2886 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2887 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2888 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2889 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2891 * This version ignores our makpkt and needs to be throttled.
2893 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2894 logevent("We believe remote version ignores SSH-2 maximum packet size");
2897 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2899 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2900 * none detected automatically.
2902 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2903 logevent("We believe remote version has SSH-2 ignore bug");
2906 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2907 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2908 (wc_match("OpenSSH_2.[235]*", imp)))) {
2910 * These versions only support the original (pre-RFC4419)
2911 * SSH-2 GEX request, and disconnect with a protocol error if
2912 * we use the newer version.
2914 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2915 logevent("We believe remote version has outdated SSH-2 GEX");
2918 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2920 * Servers that don't support our winadj request for one
2921 * reason or another. Currently, none detected automatically.
2923 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2924 logevent("We believe remote version has winadj bug");
2927 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2928 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2929 (wc_match("OpenSSH_[2-5].*", imp) ||
2930 wc_match("OpenSSH_6.[0-6]*", imp) ||
2931 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2932 wc_match("dropbear_0.5[01]*", imp)))) {
2934 * These versions have the SSH-2 channel request bug.
2935 * OpenSSH 6.7 and above do not:
2936 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2937 * dropbear_0.52 and above do not:
2938 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2940 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2941 logevent("We believe remote version has SSH-2 channel request bug");
2946 * The `software version' part of an SSH version string is required
2947 * to contain no spaces or minus signs.
2949 static void ssh_fix_verstring(char *str)
2951 /* Eat "<protoversion>-". */
2952 while (*str && *str != '-') str++;
2953 assert(*str == '-'); str++;
2955 /* Convert minus signs and spaces in the remaining string into
2958 if (*str == '-' || *str == ' ')
2965 * Send an appropriate SSH version string.
2967 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2971 if (ssh->version == 2) {
2973 * Construct a v2 version string.
2975 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2978 * Construct a v1 version string.
2980 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2981 verstring = dupprintf("SSH-%s-%s\012",
2982 (ssh_versioncmp(svers, "1.5") <= 0 ?
2987 ssh_fix_verstring(verstring + strlen(protoname));
2989 if (ssh->version == 2) {
2992 * Record our version string.
2994 len = strcspn(verstring, "\015\012");
2995 ssh->v_c = snewn(len + 1, char);
2996 memcpy(ssh->v_c, verstring, len);
3000 logeventf(ssh, "We claim version: %.*s",
3001 strcspn(verstring, "\015\012"), verstring);
3002 s_write(ssh, verstring, strlen(verstring));
3006 static int do_ssh_init(Ssh ssh, unsigned char c)
3008 static const char protoname[] = "SSH-";
3010 struct do_ssh_init_state {
3019 crState(do_ssh_init_state);
3023 /* Search for a line beginning with the protocol name prefix in
3026 for (s->i = 0; protoname[s->i]; s->i++) {
3027 if ((char)c != protoname[s->i]) goto no;
3037 s->vstrsize = sizeof(protoname) + 16;
3038 s->vstring = snewn(s->vstrsize, char);
3039 strcpy(s->vstring, protoname);
3040 s->vslen = strlen(protoname);
3043 if (s->vslen >= s->vstrsize - 1) {
3045 s->vstring = sresize(s->vstring, s->vstrsize, char);
3047 s->vstring[s->vslen++] = c;
3050 s->version[s->i] = '\0';
3052 } else if (s->i < sizeof(s->version) - 1)
3053 s->version[s->i++] = c;
3054 } else if (c == '\012')
3056 crReturn(1); /* get another char */
3059 ssh->agentfwd_enabled = FALSE;
3060 ssh->rdpkt2_state.incoming_sequence = 0;
3062 s->vstring[s->vslen] = 0;
3063 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3064 logeventf(ssh, "Server version: %s", s->vstring);
3065 ssh_detect_bugs(ssh, s->vstring);
3068 * Decide which SSH protocol version to support.
3071 /* Anything strictly below "2.0" means protocol 1 is supported. */
3072 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3073 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3074 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3076 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
3077 bombout(("SSH protocol version 1 required by configuration but "
3078 "not provided by server"));
3081 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3082 bombout(("SSH protocol version 2 required by configuration but "
3083 "not provided by server"));
3087 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3092 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3094 /* Send the version string, if we haven't already */
3095 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3096 ssh_send_verstring(ssh, protoname, s->version);
3098 if (ssh->version == 2) {
3101 * Record their version string.
3103 len = strcspn(s->vstring, "\015\012");
3104 ssh->v_s = snewn(len + 1, char);
3105 memcpy(ssh->v_s, s->vstring, len);
3109 * Initialise SSH-2 protocol.
3111 ssh->protocol = ssh2_protocol;
3112 ssh2_protocol_setup(ssh);
3113 ssh->s_rdpkt = ssh2_rdpkt;
3116 * Initialise SSH-1 protocol.
3118 ssh->protocol = ssh1_protocol;
3119 ssh1_protocol_setup(ssh);
3120 ssh->s_rdpkt = ssh1_rdpkt;
3122 if (ssh->version == 2)
3123 do_ssh2_transport(ssh, NULL, -1, NULL);
3125 update_specials_menu(ssh->frontend);
3126 ssh->state = SSH_STATE_BEFORE_SIZE;
3127 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3134 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3137 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3138 * the ssh-connection part, extracted and given a trivial binary
3139 * packet protocol, so we replace 'SSH-' at the start with a new
3140 * name. In proper SSH style (though of course this part of the
3141 * proper SSH protocol _isn't_ subject to this kind of
3142 * DNS-domain-based extension), we define the new name in our
3145 static const char protoname[] =
3146 "SSHCONNECTION@putty.projects.tartarus.org-";
3148 struct do_ssh_connection_init_state {
3156 crState(do_ssh_connection_init_state);
3160 /* Search for a line beginning with the protocol name prefix in
3163 for (s->i = 0; protoname[s->i]; s->i++) {
3164 if ((char)c != protoname[s->i]) goto no;
3174 s->vstrsize = sizeof(protoname) + 16;
3175 s->vstring = snewn(s->vstrsize, char);
3176 strcpy(s->vstring, protoname);
3177 s->vslen = strlen(protoname);
3180 if (s->vslen >= s->vstrsize - 1) {
3182 s->vstring = sresize(s->vstring, s->vstrsize, char);
3184 s->vstring[s->vslen++] = c;
3187 s->version[s->i] = '\0';
3189 } else if (s->i < sizeof(s->version) - 1)
3190 s->version[s->i++] = c;
3191 } else if (c == '\012')
3193 crReturn(1); /* get another char */
3196 ssh->agentfwd_enabled = FALSE;
3197 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3199 s->vstring[s->vslen] = 0;
3200 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3201 logeventf(ssh, "Server version: %s", s->vstring);
3202 ssh_detect_bugs(ssh, s->vstring);
3205 * Decide which SSH protocol version to support. This is easy in
3206 * bare ssh-connection mode: only 2.0 is legal.
3208 if (ssh_versioncmp(s->version, "2.0") < 0) {
3209 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3212 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3213 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3219 logeventf(ssh, "Using bare ssh-connection protocol");
3221 /* Send the version string, if we haven't already */
3222 ssh_send_verstring(ssh, protoname, s->version);
3225 * Initialise bare connection protocol.
3227 ssh->protocol = ssh2_bare_connection_protocol;
3228 ssh2_bare_connection_protocol_setup(ssh);
3229 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3231 update_specials_menu(ssh->frontend);
3232 ssh->state = SSH_STATE_BEFORE_SIZE;
3233 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3236 * Get authconn (really just conn) under way.
3238 do_ssh2_authconn(ssh, NULL, 0, NULL);
3245 static void ssh_process_incoming_data(Ssh ssh,
3246 unsigned char **data, int *datalen)
3248 struct Packet *pktin;
3250 pktin = ssh->s_rdpkt(ssh, data, datalen);
3252 ssh->protocol(ssh, NULL, 0, pktin);
3253 ssh_free_packet(pktin);
3257 static void ssh_queue_incoming_data(Ssh ssh,
3258 unsigned char **data, int *datalen)
3260 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3265 static void ssh_process_queued_incoming_data(Ssh ssh)
3268 unsigned char *data;
3271 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3272 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3276 while (!ssh->frozen && len > 0)
3277 ssh_process_incoming_data(ssh, &data, &len);
3280 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3284 static void ssh_set_frozen(Ssh ssh, int frozen)
3287 sk_set_frozen(ssh->s, frozen);
3288 ssh->frozen = frozen;
3291 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3293 /* Log raw data, if we're in that mode. */
3295 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3296 0, NULL, NULL, 0, NULL);
3298 crBegin(ssh->ssh_gotdata_crstate);
3301 * To begin with, feed the characters one by one to the
3302 * protocol initialisation / selection function do_ssh_init().
3303 * When that returns 0, we're done with the initial greeting
3304 * exchange and can move on to packet discipline.
3307 int ret; /* need not be kept across crReturn */
3309 crReturnV; /* more data please */
3310 ret = ssh->do_ssh_init(ssh, *data);
3318 * We emerge from that loop when the initial negotiation is
3319 * over and we have selected an s_rdpkt function. Now pass
3320 * everything to s_rdpkt, and then pass the resulting packets
3321 * to the proper protocol handler.
3325 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3327 ssh_queue_incoming_data(ssh, &data, &datalen);
3328 /* This uses up all data and cannot cause anything interesting
3329 * to happen; indeed, for anything to happen at all, we must
3330 * return, so break out. */
3332 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3333 /* This uses up some or all data, and may freeze the
3335 ssh_process_queued_incoming_data(ssh);
3337 /* This uses up some or all data, and may freeze the
3339 ssh_process_incoming_data(ssh, &data, &datalen);
3341 /* FIXME this is probably EBW. */
3342 if (ssh->state == SSH_STATE_CLOSED)
3345 /* We're out of data. Go and get some more. */
3351 static int ssh_do_close(Ssh ssh, int notify_exit)
3354 struct ssh_channel *c;
3356 ssh->state = SSH_STATE_CLOSED;
3357 expire_timer_context(ssh);
3362 notify_remote_exit(ssh->frontend);
3367 * Now we must shut down any port- and X-forwarded channels going
3368 * through this connection.
3370 if (ssh->channels) {
3371 while (NULL != (c = index234(ssh->channels, 0))) {
3374 x11_close(c->u.x11.xconn);
3377 case CHAN_SOCKDATA_DORMANT:
3378 pfd_close(c->u.pfd.pf);
3381 del234(ssh->channels, c); /* moving next one to index 0 */
3382 if (ssh->version == 2)
3383 bufchain_clear(&c->v.v2.outbuffer);
3388 * Go through port-forwardings, and close any associated
3389 * listening sockets.
3391 if (ssh->portfwds) {
3392 struct ssh_portfwd *pf;
3393 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3394 /* Dispose of any listening socket. */
3396 pfl_terminate(pf->local);
3397 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3400 freetree234(ssh->portfwds);
3401 ssh->portfwds = NULL;
3405 * Also stop attempting to connection-share.
3407 if (ssh->connshare) {
3408 sharestate_free(ssh->connshare);
3409 ssh->connshare = NULL;
3415 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3416 const char *error_msg, int error_code)
3418 Ssh ssh = (Ssh) plug;
3419 char addrbuf[256], *msg;
3421 if (ssh->attempting_connshare) {
3423 * While we're attempting connection sharing, don't loudly log
3424 * everything that happens. Real TCP connections need to be
3425 * logged when we _start_ trying to connect, because it might
3426 * be ages before they respond if something goes wrong; but
3427 * connection sharing is local and quick to respond, and it's
3428 * sufficient to simply wait and see whether it worked
3432 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3435 if (sk_addr_needs_port(addr)) {
3436 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3438 msg = dupprintf("Connecting to %s", addrbuf);
3441 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3449 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3450 const char *ds_err, const char *us_err)
3452 if (event == SHARE_NONE) {
3453 /* In this case, 'logtext' is an error message indicating a
3454 * reason why connection sharing couldn't be set up _at all_.
3455 * Failing that, ds_err and us_err indicate why we couldn't be
3456 * a downstream and an upstream respectively. */
3458 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3461 logeventf(ssh, "Could not set up connection sharing"
3462 " as downstream: %s", ds_err);
3464 logeventf(ssh, "Could not set up connection sharing"
3465 " as upstream: %s", us_err);
3467 } else if (event == SHARE_DOWNSTREAM) {
3468 /* In this case, 'logtext' is a local endpoint address */
3469 logeventf(ssh, "Using existing shared connection at %s", logtext);
3470 /* Also we should mention this in the console window to avoid
3471 * confusing users as to why this window doesn't behave the
3473 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3474 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3476 } else if (event == SHARE_UPSTREAM) {
3477 /* In this case, 'logtext' is a local endpoint address too */
3478 logeventf(ssh, "Sharing this connection at %s", logtext);
3482 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3485 Ssh ssh = (Ssh) plug;
3486 int need_notify = ssh_do_close(ssh, FALSE);
3489 if (!ssh->close_expected)
3490 error_msg = "Server unexpectedly closed network connection";
3492 error_msg = "Server closed network connection";
3495 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3499 notify_remote_exit(ssh->frontend);
3502 logevent(error_msg);
3503 if (!ssh->close_expected || !ssh->clean_exit)
3504 connection_fatal(ssh->frontend, "%s", error_msg);
3508 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3510 Ssh ssh = (Ssh) plug;
3511 ssh_gotdata(ssh, (unsigned char *)data, len);
3512 if (ssh->state == SSH_STATE_CLOSED) {
3513 ssh_do_close(ssh, TRUE);
3519 static void ssh_sent(Plug plug, int bufsize)
3521 Ssh ssh = (Ssh) plug;
3523 * If the send backlog on the SSH socket itself clears, we
3524 * should unthrottle the whole world if it was throttled.
3526 if (bufsize < SSH_MAX_BACKLOG)
3527 ssh_throttle_all(ssh, 0, bufsize);
3531 * Connect to specified host and port.
3532 * Returns an error message, or NULL on success.
3533 * Also places the canonical host name into `realhost'. It must be
3534 * freed by the caller.
3536 static const char *connect_to_host(Ssh ssh, char *host, int port,
3537 char **realhost, int nodelay, int keepalive)
3539 static const struct plug_function_table fn_table = {
3550 int addressfamily, sshprot;
3552 loghost = conf_get_str(ssh->conf, CONF_loghost);
3557 tmphost = dupstr(loghost);
3558 ssh->savedport = 22; /* default ssh port */
3561 * A colon suffix on the hostname string also lets us affect
3562 * savedport. (Unless there are multiple colons, in which case
3563 * we assume this is an unbracketed IPv6 literal.)
3565 colon = host_strrchr(tmphost, ':');
3566 if (colon && colon == host_strchr(tmphost, ':')) {
3569 ssh->savedport = atoi(colon);
3572 ssh->savedhost = host_strduptrim(tmphost);
3575 ssh->savedhost = host_strduptrim(host);
3577 port = 22; /* default ssh port */
3578 ssh->savedport = port;
3581 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3584 * Try connection-sharing, in case that means we don't open a
3585 * socket after all. ssh_connection_sharing_init will connect to a
3586 * previously established upstream if it can, and failing that,
3587 * establish a listening socket for _us_ to be the upstream. In
3588 * the latter case it will return NULL just as if it had done
3589 * nothing, because here we only need to care if we're a
3590 * downstream and need to do our connection setup differently.
3592 ssh->connshare = NULL;
3593 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3594 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3595 ssh->conf, ssh, &ssh->connshare);
3596 ssh->attempting_connshare = FALSE;
3597 if (ssh->s != NULL) {
3599 * We are a downstream.
3601 ssh->bare_connection = TRUE;
3602 ssh->do_ssh_init = do_ssh_connection_init;
3603 ssh->fullhostname = NULL;
3604 *realhost = dupstr(host); /* best we can do */
3607 * We're not a downstream, so open a normal socket.
3609 ssh->do_ssh_init = do_ssh_init;
3614 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3615 logeventf(ssh, "Looking up host \"%s\"%s", host,
3616 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3617 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3618 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3619 if ((err = sk_addr_error(addr)) != NULL) {
3623 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3625 ssh->s = new_connection(addr, *realhost, port,
3626 0, 1, nodelay, keepalive,
3627 (Plug) ssh, ssh->conf);
3628 if ((err = sk_socket_error(ssh->s)) != NULL) {
3630 notify_remote_exit(ssh->frontend);
3636 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3637 * send the version string too.
3639 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3642 if (sshprot == 3 && !ssh->bare_connection) {
3644 ssh_send_verstring(ssh, "SSH-", NULL);
3648 * loghost, if configured, overrides realhost.
3652 *realhost = dupstr(loghost);
3659 * Throttle or unthrottle the SSH connection.
3661 static void ssh_throttle_conn(Ssh ssh, int adjust)
3663 int old_count = ssh->conn_throttle_count;
3664 ssh->conn_throttle_count += adjust;
3665 assert(ssh->conn_throttle_count >= 0);
3666 if (ssh->conn_throttle_count && !old_count) {
3667 ssh_set_frozen(ssh, 1);
3668 } else if (!ssh->conn_throttle_count && old_count) {
3669 ssh_set_frozen(ssh, 0);
3674 * Throttle or unthrottle _all_ local data streams (for when sends
3675 * on the SSH connection itself back up).
3677 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3680 struct ssh_channel *c;
3682 if (enable == ssh->throttled_all)
3684 ssh->throttled_all = enable;
3685 ssh->overall_bufsize = bufsize;
3688 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3690 case CHAN_MAINSESSION:
3692 * This is treated separately, outside the switch.
3696 x11_override_throttle(c->u.x11.xconn, enable);
3699 /* Agent channels require no buffer management. */
3702 pfd_override_throttle(c->u.pfd.pf, enable);
3708 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3710 Ssh ssh = (Ssh) sshv;
3712 ssh->agent_response = reply;
3713 ssh->agent_response_len = replylen;
3715 if (ssh->version == 1)
3716 do_ssh1_login(ssh, NULL, -1, NULL);
3718 do_ssh2_authconn(ssh, NULL, -1, NULL);
3721 static void ssh_dialog_callback(void *sshv, int ret)
3723 Ssh ssh = (Ssh) sshv;
3725 ssh->user_response = ret;
3727 if (ssh->version == 1)
3728 do_ssh1_login(ssh, NULL, -1, NULL);
3730 do_ssh2_transport(ssh, NULL, -1, NULL);
3733 * This may have unfrozen the SSH connection, so do a
3736 ssh_process_queued_incoming_data(ssh);
3739 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3741 struct ssh_channel *c = (struct ssh_channel *)cv;
3743 void *sentreply = reply;
3745 c->u.a.outstanding_requests--;
3747 /* Fake SSH_AGENT_FAILURE. */
3748 sentreply = "\0\0\0\1\5";
3751 if (ssh->version == 2) {
3752 ssh2_add_channel_data(c, sentreply, replylen);
3755 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3756 PKT_INT, c->remoteid,
3758 PKT_DATA, sentreply, replylen,
3764 * If we've already seen an incoming EOF but haven't sent an
3765 * outgoing one, this may be the moment to send it.
3767 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3768 sshfwd_write_eof(c);
3772 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3773 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3774 * => log `wire_reason'.
3776 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3777 int code, int clean_exit)
3781 client_reason = wire_reason;
3783 error = dupprintf("Disconnected: %s", client_reason);
3785 error = dupstr("Disconnected");
3787 if (ssh->version == 1) {
3788 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3790 } else if (ssh->version == 2) {
3791 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3792 ssh2_pkt_adduint32(pktout, code);
3793 ssh2_pkt_addstring(pktout, wire_reason);
3794 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3795 ssh2_pkt_send_noqueue(ssh, pktout);
3798 ssh->close_expected = TRUE;
3799 ssh->clean_exit = clean_exit;
3800 ssh_closing((Plug)ssh, error, 0, 0);
3804 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3805 const struct ssh_signkey *ssh2keytype,
3808 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3809 return -1; /* no manual keys configured */
3814 * The fingerprint string we've been given will have things
3815 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3816 * narrow down to just the colon-separated hex block at the
3817 * end of the string.
3819 const char *p = strrchr(fingerprint, ' ');
3820 fingerprint = p ? p+1 : fingerprint;
3821 /* Quick sanity checks, including making sure it's in lowercase */
3822 assert(strlen(fingerprint) == 16*3 - 1);
3823 assert(fingerprint[2] == ':');
3824 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3826 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3828 return 1; /* success */
3833 * Construct the base64-encoded public key blob and see if
3836 unsigned char *binblob;
3838 int binlen, atoms, i;
3839 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3840 atoms = (binlen + 2) / 3;
3841 base64blob = snewn(atoms * 4 + 1, char);
3842 for (i = 0; i < atoms; i++)
3843 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3844 base64blob[atoms * 4] = '\0';
3846 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3849 return 1; /* success */
3858 * Handle the key exchange and user authentication phases.
3860 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3861 struct Packet *pktin)
3864 unsigned char cookie[8], *ptr;
3865 struct MD5Context md5c;
3866 struct do_ssh1_login_state {
3869 unsigned char *rsabuf;
3870 const unsigned char *keystr1, *keystr2;
3871 unsigned long supported_ciphers_mask, supported_auths_mask;
3872 int tried_publickey, tried_agent;
3873 int tis_auth_refused, ccard_auth_refused;
3874 unsigned char session_id[16];
3876 void *publickey_blob;
3877 int publickey_bloblen;
3878 char *publickey_comment;
3879 int privatekey_available, privatekey_encrypted;
3880 prompts_t *cur_prompt;
3883 unsigned char request[5], *response, *p;
3893 struct RSAKey servkey, hostkey;
3895 crState(do_ssh1_login_state);
3902 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3903 bombout(("Public key packet not received"));
3907 logevent("Received public keys");
3909 ptr = ssh_pkt_getdata(pktin, 8);
3911 bombout(("SSH-1 public key packet stopped before random cookie"));
3914 memcpy(cookie, ptr, 8);
3916 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3917 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3918 bombout(("Failed to read SSH-1 public keys from public key packet"));
3923 * Log the host key fingerprint.
3927 logevent("Host key fingerprint is:");
3928 strcpy(logmsg, " ");
3929 s->hostkey.comment = NULL;
3930 rsa_fingerprint(logmsg + strlen(logmsg),
3931 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3935 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3936 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3937 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3938 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3939 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3941 ssh->v1_local_protoflags =
3942 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3943 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3946 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3947 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3948 MD5Update(&md5c, cookie, 8);
3949 MD5Final(s->session_id, &md5c);
3951 for (i = 0; i < 32; i++)
3952 ssh->session_key[i] = random_byte();
3955 * Verify that the `bits' and `bytes' parameters match.
3957 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3958 s->servkey.bits > s->servkey.bytes * 8) {
3959 bombout(("SSH-1 public keys were badly formatted"));
3963 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3964 s->hostkey.bytes : s->servkey.bytes);
3966 s->rsabuf = snewn(s->len, unsigned char);
3969 * Verify the host key.
3973 * First format the key into a string.
3975 int len = rsastr_len(&s->hostkey);
3976 char fingerprint[100];
3977 char *keystr = snewn(len, char);
3978 rsastr_fmt(keystr, &s->hostkey);
3979 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3981 /* First check against manually configured host keys. */
3982 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3983 if (s->dlgret == 0) { /* did not match */
3984 bombout(("Host key did not appear in manually configured list"));
3987 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3988 ssh_set_frozen(ssh, 1);
3989 s->dlgret = verify_ssh_host_key(ssh->frontend,
3990 ssh->savedhost, ssh->savedport,
3991 "rsa", keystr, fingerprint,
3992 ssh_dialog_callback, ssh);
3994 if (s->dlgret < 0) {
3998 bombout(("Unexpected data from server while waiting"
3999 " for user host key response"));
4002 } while (pktin || inlen > 0);
4003 s->dlgret = ssh->user_response;
4005 ssh_set_frozen(ssh, 0);
4007 if (s->dlgret == 0) {
4008 ssh_disconnect(ssh, "User aborted at host key verification",
4017 for (i = 0; i < 32; i++) {
4018 s->rsabuf[i] = ssh->session_key[i];
4020 s->rsabuf[i] ^= s->session_id[i];
4023 if (s->hostkey.bytes > s->servkey.bytes) {
4024 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4026 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4028 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4030 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4033 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4037 logevent("Encrypted session key");
4040 int cipher_chosen = 0, warn = 0;
4041 char *cipher_string = NULL;
4043 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4044 int next_cipher = conf_get_int_int(ssh->conf,
4045 CONF_ssh_cipherlist, i);
4046 if (next_cipher == CIPHER_WARN) {
4047 /* If/when we choose a cipher, warn about it */
4049 } else if (next_cipher == CIPHER_AES) {
4050 /* XXX Probably don't need to mention this. */
4051 logevent("AES not supported in SSH-1, skipping");
4053 switch (next_cipher) {
4054 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4055 cipher_string = "3DES"; break;
4056 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4057 cipher_string = "Blowfish"; break;
4058 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4059 cipher_string = "single-DES"; break;
4061 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4065 if (!cipher_chosen) {
4066 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4067 bombout(("Server violates SSH-1 protocol by not "
4068 "supporting 3DES encryption"));
4070 /* shouldn't happen */
4071 bombout(("No supported ciphers found"));
4075 /* Warn about chosen cipher if necessary. */
4077 ssh_set_frozen(ssh, 1);
4078 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4079 ssh_dialog_callback, ssh);
4080 if (s->dlgret < 0) {
4084 bombout(("Unexpected data from server while waiting"
4085 " for user response"));
4088 } while (pktin || inlen > 0);
4089 s->dlgret = ssh->user_response;
4091 ssh_set_frozen(ssh, 0);
4092 if (s->dlgret == 0) {
4093 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4100 switch (s->cipher_type) {
4101 case SSH_CIPHER_3DES:
4102 logevent("Using 3DES encryption");
4104 case SSH_CIPHER_DES:
4105 logevent("Using single-DES encryption");
4107 case SSH_CIPHER_BLOWFISH:
4108 logevent("Using Blowfish encryption");
4112 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4113 PKT_CHAR, s->cipher_type,
4114 PKT_DATA, cookie, 8,
4115 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4116 PKT_DATA, s->rsabuf, s->len,
4117 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4119 logevent("Trying to enable encryption...");
4123 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4124 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4126 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4127 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4128 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4130 ssh->crcda_ctx = crcda_make_context();
4131 logevent("Installing CRC compensation attack detector");
4133 if (s->servkey.modulus) {
4134 sfree(s->servkey.modulus);
4135 s->servkey.modulus = NULL;
4137 if (s->servkey.exponent) {
4138 sfree(s->servkey.exponent);
4139 s->servkey.exponent = NULL;
4141 if (s->hostkey.modulus) {
4142 sfree(s->hostkey.modulus);
4143 s->hostkey.modulus = NULL;
4145 if (s->hostkey.exponent) {
4146 sfree(s->hostkey.exponent);
4147 s->hostkey.exponent = NULL;
4151 if (pktin->type != SSH1_SMSG_SUCCESS) {
4152 bombout(("Encryption not successfully enabled"));
4156 logevent("Successfully started encryption");
4158 fflush(stdout); /* FIXME eh? */
4160 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4161 int ret; /* need not be kept over crReturn */
4162 s->cur_prompt = new_prompts(ssh->frontend);
4163 s->cur_prompt->to_server = TRUE;
4164 s->cur_prompt->name = dupstr("SSH login name");
4165 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4166 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4169 crWaitUntil(!pktin);
4170 ret = get_userpass_input(s->cur_prompt, in, inlen);
4175 * Failed to get a username. Terminate.
4177 free_prompts(s->cur_prompt);
4178 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4181 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4182 free_prompts(s->cur_prompt);
4185 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4187 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4189 if (flags & FLAG_INTERACTIVE &&
4190 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4191 c_write_str(ssh, userlog);
4192 c_write_str(ssh, "\r\n");
4200 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4201 /* We must not attempt PK auth. Pretend we've already tried it. */
4202 s->tried_publickey = s->tried_agent = 1;
4204 s->tried_publickey = s->tried_agent = 0;
4206 s->tis_auth_refused = s->ccard_auth_refused = 0;
4208 * Load the public half of any configured keyfile for later use.
4210 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4211 if (!filename_is_null(s->keyfile)) {
4213 logeventf(ssh, "Reading key file \"%.150s\"",
4214 filename_to_str(s->keyfile));
4215 keytype = key_type(s->keyfile);
4216 if (keytype == SSH_KEYTYPE_SSH1 ||
4217 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4219 if (rsakey_pubblob(s->keyfile,
4220 &s->publickey_blob, &s->publickey_bloblen,
4221 &s->publickey_comment, &error)) {
4222 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4223 if (!s->privatekey_available)
4224 logeventf(ssh, "Key file contains public key only");
4225 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4229 logeventf(ssh, "Unable to load key (%s)", error);
4230 msgbuf = dupprintf("Unable to load key file "
4231 "\"%.150s\" (%s)\r\n",
4232 filename_to_str(s->keyfile),
4234 c_write_str(ssh, msgbuf);
4236 s->publickey_blob = NULL;
4240 logeventf(ssh, "Unable to use this key file (%s)",
4241 key_type_to_str(keytype));
4242 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4244 filename_to_str(s->keyfile),
4245 key_type_to_str(keytype));
4246 c_write_str(ssh, msgbuf);
4248 s->publickey_blob = NULL;
4251 s->publickey_blob = NULL;
4253 while (pktin->type == SSH1_SMSG_FAILURE) {
4254 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4256 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4258 * Attempt RSA authentication using Pageant.
4264 logevent("Pageant is running. Requesting keys.");
4266 /* Request the keys held by the agent. */
4267 PUT_32BIT(s->request, 1);
4268 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4269 if (!agent_query(s->request, 5, &r, &s->responselen,
4270 ssh_agent_callback, ssh)) {
4274 bombout(("Unexpected data from server while waiting"
4275 " for agent response"));
4278 } while (pktin || inlen > 0);
4279 r = ssh->agent_response;
4280 s->responselen = ssh->agent_response_len;
4282 s->response = (unsigned char *) r;
4283 if (s->response && s->responselen >= 5 &&
4284 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4285 s->p = s->response + 5;
4286 s->nkeys = toint(GET_32BIT(s->p));
4288 logeventf(ssh, "Pageant reported negative key count %d",
4293 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4294 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4295 unsigned char *pkblob = s->p;
4299 do { /* do while (0) to make breaking easy */
4300 n = ssh1_read_bignum
4301 (s->p, toint(s->responselen-(s->p-s->response)),
4306 n = ssh1_read_bignum
4307 (s->p, toint(s->responselen-(s->p-s->response)),
4312 if (s->responselen - (s->p-s->response) < 4)
4314 s->commentlen = toint(GET_32BIT(s->p));
4316 if (s->commentlen < 0 ||
4317 toint(s->responselen - (s->p-s->response)) <
4320 s->commentp = (char *)s->p;
4321 s->p += s->commentlen;
4325 logevent("Pageant key list packet was truncated");
4329 if (s->publickey_blob) {
4330 if (!memcmp(pkblob, s->publickey_blob,
4331 s->publickey_bloblen)) {
4332 logeventf(ssh, "Pageant key #%d matches "
4333 "configured key file", s->keyi);
4334 s->tried_publickey = 1;
4336 /* Skip non-configured key */
4339 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4340 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4341 PKT_BIGNUM, s->key.modulus, PKT_END);
4343 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4344 logevent("Key refused");
4347 logevent("Received RSA challenge");
4348 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4349 bombout(("Server's RSA challenge was badly formatted"));
4354 char *agentreq, *q, *ret;
4357 len = 1 + 4; /* message type, bit count */
4358 len += ssh1_bignum_length(s->key.exponent);
4359 len += ssh1_bignum_length(s->key.modulus);
4360 len += ssh1_bignum_length(s->challenge);
4361 len += 16; /* session id */
4362 len += 4; /* response format */
4363 agentreq = snewn(4 + len, char);
4364 PUT_32BIT(agentreq, len);
4366 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4367 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4369 q += ssh1_write_bignum(q, s->key.exponent);
4370 q += ssh1_write_bignum(q, s->key.modulus);
4371 q += ssh1_write_bignum(q, s->challenge);
4372 memcpy(q, s->session_id, 16);
4374 PUT_32BIT(q, 1); /* response format */
4375 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4376 ssh_agent_callback, ssh)) {
4381 bombout(("Unexpected data from server"
4382 " while waiting for agent"
4386 } while (pktin || inlen > 0);
4387 vret = ssh->agent_response;
4388 retlen = ssh->agent_response_len;
4393 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4394 logevent("Sending Pageant's response");
4395 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4396 PKT_DATA, ret + 5, 16,
4400 if (pktin->type == SSH1_SMSG_SUCCESS) {
4402 ("Pageant's response accepted");
4403 if (flags & FLAG_VERBOSE) {
4404 c_write_str(ssh, "Authenticated using"
4406 c_write(ssh, s->commentp,
4408 c_write_str(ssh, "\" from agent\r\n");
4413 ("Pageant's response not accepted");
4416 ("Pageant failed to answer challenge");
4420 logevent("No reply received from Pageant");
4423 freebn(s->key.exponent);
4424 freebn(s->key.modulus);
4425 freebn(s->challenge);
4430 if (s->publickey_blob && !s->tried_publickey)
4431 logevent("Configured key file not in Pageant");
4433 logevent("Failed to get reply from Pageant");
4438 if (s->publickey_blob && s->privatekey_available &&
4439 !s->tried_publickey) {
4441 * Try public key authentication with the specified
4444 int got_passphrase; /* need not be kept over crReturn */
4445 if (flags & FLAG_VERBOSE)
4446 c_write_str(ssh, "Trying public key authentication.\r\n");
4447 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4448 logeventf(ssh, "Trying public key \"%s\"",
4449 filename_to_str(s->keyfile));
4450 s->tried_publickey = 1;
4451 got_passphrase = FALSE;
4452 while (!got_passphrase) {
4454 * Get a passphrase, if necessary.
4456 char *passphrase = NULL; /* only written after crReturn */
4458 if (!s->privatekey_encrypted) {
4459 if (flags & FLAG_VERBOSE)
4460 c_write_str(ssh, "No passphrase required.\r\n");
4463 int ret; /* need not be kept over crReturn */
4464 s->cur_prompt = new_prompts(ssh->frontend);
4465 s->cur_prompt->to_server = FALSE;
4466 s->cur_prompt->name = dupstr("SSH key passphrase");
4467 add_prompt(s->cur_prompt,
4468 dupprintf("Passphrase for key \"%.100s\": ",
4469 s->publickey_comment), FALSE);
4470 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4473 crWaitUntil(!pktin);
4474 ret = get_userpass_input(s->cur_prompt, in, inlen);
4478 /* Failed to get a passphrase. Terminate. */
4479 free_prompts(s->cur_prompt);
4480 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4484 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4485 free_prompts(s->cur_prompt);
4488 * Try decrypting key with passphrase.
4490 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4491 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4494 smemclr(passphrase, strlen(passphrase));
4498 /* Correct passphrase. */
4499 got_passphrase = TRUE;
4500 } else if (ret == 0) {
4501 c_write_str(ssh, "Couldn't load private key from ");
4502 c_write_str(ssh, filename_to_str(s->keyfile));
4503 c_write_str(ssh, " (");
4504 c_write_str(ssh, error);
4505 c_write_str(ssh, ").\r\n");
4506 got_passphrase = FALSE;
4507 break; /* go and try something else */
4508 } else if (ret == -1) {
4509 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4510 got_passphrase = FALSE;
4513 assert(0 && "unexpected return from loadrsakey()");
4514 got_passphrase = FALSE; /* placate optimisers */
4518 if (got_passphrase) {
4521 * Send a public key attempt.
4523 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4524 PKT_BIGNUM, s->key.modulus, PKT_END);
4527 if (pktin->type == SSH1_SMSG_FAILURE) {
4528 c_write_str(ssh, "Server refused our public key.\r\n");
4529 continue; /* go and try something else */
4531 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4532 bombout(("Bizarre response to offer of public key"));
4538 unsigned char buffer[32];
4539 Bignum challenge, response;
4541 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4542 bombout(("Server's RSA challenge was badly formatted"));
4545 response = rsadecrypt(challenge, &s->key);
4546 freebn(s->key.private_exponent);/* burn the evidence */
4548 for (i = 0; i < 32; i++) {
4549 buffer[i] = bignum_byte(response, 31 - i);
4553 MD5Update(&md5c, buffer, 32);
4554 MD5Update(&md5c, s->session_id, 16);
4555 MD5Final(buffer, &md5c);
4557 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4558 PKT_DATA, buffer, 16, PKT_END);
4565 if (pktin->type == SSH1_SMSG_FAILURE) {
4566 if (flags & FLAG_VERBOSE)
4567 c_write_str(ssh, "Failed to authenticate with"
4568 " our public key.\r\n");
4569 continue; /* go and try something else */
4570 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4571 bombout(("Bizarre response to RSA authentication response"));
4575 break; /* we're through! */
4581 * Otherwise, try various forms of password-like authentication.
4583 s->cur_prompt = new_prompts(ssh->frontend);
4585 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4586 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4587 !s->tis_auth_refused) {
4588 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4589 logevent("Requested TIS authentication");
4590 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4592 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4593 logevent("TIS authentication declined");
4594 if (flags & FLAG_INTERACTIVE)
4595 c_write_str(ssh, "TIS authentication refused.\r\n");
4596 s->tis_auth_refused = 1;
4601 char *instr_suf, *prompt;
4603 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4605 bombout(("TIS challenge packet was badly formed"));
4608 logevent("Received TIS challenge");
4609 s->cur_prompt->to_server = TRUE;
4610 s->cur_prompt->name = dupstr("SSH TIS authentication");
4611 /* Prompt heuristic comes from OpenSSH */
4612 if (memchr(challenge, '\n', challengelen)) {
4613 instr_suf = dupstr("");
4614 prompt = dupprintf("%.*s", challengelen, challenge);
4616 instr_suf = dupprintf("%.*s", challengelen, challenge);
4617 prompt = dupstr("Response: ");
4619 s->cur_prompt->instruction =
4620 dupprintf("Using TIS authentication.%s%s",
4621 (*instr_suf) ? "\n" : "",
4623 s->cur_prompt->instr_reqd = TRUE;
4624 add_prompt(s->cur_prompt, prompt, FALSE);
4628 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4629 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4630 !s->ccard_auth_refused) {
4631 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4632 logevent("Requested CryptoCard authentication");
4633 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4635 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4636 logevent("CryptoCard authentication declined");
4637 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4638 s->ccard_auth_refused = 1;
4643 char *instr_suf, *prompt;
4645 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4647 bombout(("CryptoCard challenge packet was badly formed"));
4650 logevent("Received CryptoCard challenge");
4651 s->cur_prompt->to_server = TRUE;
4652 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4653 s->cur_prompt->name_reqd = FALSE;
4654 /* Prompt heuristic comes from OpenSSH */
4655 if (memchr(challenge, '\n', challengelen)) {
4656 instr_suf = dupstr("");
4657 prompt = dupprintf("%.*s", challengelen, challenge);
4659 instr_suf = dupprintf("%.*s", challengelen, challenge);
4660 prompt = dupstr("Response: ");
4662 s->cur_prompt->instruction =
4663 dupprintf("Using CryptoCard authentication.%s%s",
4664 (*instr_suf) ? "\n" : "",
4666 s->cur_prompt->instr_reqd = TRUE;
4667 add_prompt(s->cur_prompt, prompt, FALSE);
4671 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4672 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4673 bombout(("No supported authentication methods available"));
4676 s->cur_prompt->to_server = TRUE;
4677 s->cur_prompt->name = dupstr("SSH password");
4678 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4679 ssh->username, ssh->savedhost),
4684 * Show password prompt, having first obtained it via a TIS
4685 * or CryptoCard exchange if we're doing TIS or CryptoCard
4689 int ret; /* need not be kept over crReturn */
4690 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4693 crWaitUntil(!pktin);
4694 ret = get_userpass_input(s->cur_prompt, in, inlen);
4699 * Failed to get a password (for example
4700 * because one was supplied on the command line
4701 * which has already failed to work). Terminate.
4703 free_prompts(s->cur_prompt);
4704 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4709 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4711 * Defence against traffic analysis: we send a
4712 * whole bunch of packets containing strings of
4713 * different lengths. One of these strings is the
4714 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4715 * The others are all random data in
4716 * SSH1_MSG_IGNORE packets. This way a passive
4717 * listener can't tell which is the password, and
4718 * hence can't deduce the password length.
4720 * Anybody with a password length greater than 16
4721 * bytes is going to have enough entropy in their
4722 * password that a listener won't find it _that_
4723 * much help to know how long it is. So what we'll
4726 * - if password length < 16, we send 15 packets
4727 * containing string lengths 1 through 15
4729 * - otherwise, we let N be the nearest multiple
4730 * of 8 below the password length, and send 8
4731 * packets containing string lengths N through
4732 * N+7. This won't obscure the order of
4733 * magnitude of the password length, but it will
4734 * introduce a bit of extra uncertainty.
4736 * A few servers can't deal with SSH1_MSG_IGNORE, at
4737 * least in this context. For these servers, we need
4738 * an alternative defence. We make use of the fact
4739 * that the password is interpreted as a C string:
4740 * so we can append a NUL, then some random data.
4742 * A few servers can deal with neither SSH1_MSG_IGNORE
4743 * here _nor_ a padded password string.
4744 * For these servers we are left with no defences
4745 * against password length sniffing.
4747 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4748 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4750 * The server can deal with SSH1_MSG_IGNORE, so
4751 * we can use the primary defence.
4753 int bottom, top, pwlen, i;
4756 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4758 bottom = 0; /* zero length passwords are OK! :-) */
4761 bottom = pwlen & ~7;
4765 assert(pwlen >= bottom && pwlen <= top);
4767 randomstr = snewn(top + 1, char);
4769 for (i = bottom; i <= top; i++) {
4771 defer_packet(ssh, s->pwpkt_type,
4772 PKT_STR,s->cur_prompt->prompts[0]->result,
4775 for (j = 0; j < i; j++) {
4777 randomstr[j] = random_byte();
4778 } while (randomstr[j] == '\0');
4780 randomstr[i] = '\0';
4781 defer_packet(ssh, SSH1_MSG_IGNORE,
4782 PKT_STR, randomstr, PKT_END);
4785 logevent("Sending password with camouflage packets");
4786 ssh_pkt_defersend(ssh);
4789 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4791 * The server can't deal with SSH1_MSG_IGNORE
4792 * but can deal with padded passwords, so we
4793 * can use the secondary defence.
4799 len = strlen(s->cur_prompt->prompts[0]->result);
4800 if (len < sizeof(string)) {
4802 strcpy(string, s->cur_prompt->prompts[0]->result);
4803 len++; /* cover the zero byte */
4804 while (len < sizeof(string)) {
4805 string[len++] = (char) random_byte();
4808 ss = s->cur_prompt->prompts[0]->result;
4810 logevent("Sending length-padded password");
4811 send_packet(ssh, s->pwpkt_type,
4812 PKT_INT, len, PKT_DATA, ss, len,
4816 * The server is believed unable to cope with
4817 * any of our password camouflage methods.
4820 len = strlen(s->cur_prompt->prompts[0]->result);
4821 logevent("Sending unpadded password");
4822 send_packet(ssh, s->pwpkt_type,
4824 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4828 send_packet(ssh, s->pwpkt_type,
4829 PKT_STR, s->cur_prompt->prompts[0]->result,
4832 logevent("Sent password");
4833 free_prompts(s->cur_prompt);
4835 if (pktin->type == SSH1_SMSG_FAILURE) {
4836 if (flags & FLAG_VERBOSE)
4837 c_write_str(ssh, "Access denied\r\n");
4838 logevent("Authentication refused");
4839 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4840 bombout(("Strange packet received, type %d", pktin->type));
4846 if (s->publickey_blob) {
4847 sfree(s->publickey_blob);
4848 sfree(s->publickey_comment);
4851 logevent("Authentication successful");
4856 static void ssh_channel_try_eof(struct ssh_channel *c)
4859 assert(c->pending_eof); /* precondition for calling us */
4861 return; /* can't close: not even opened yet */
4862 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4863 return; /* can't send EOF: pending outgoing data */
4865 c->pending_eof = FALSE; /* we're about to send it */
4866 if (ssh->version == 1) {
4867 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4869 c->closes |= CLOSES_SENT_EOF;
4871 struct Packet *pktout;
4872 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4873 ssh2_pkt_adduint32(pktout, c->remoteid);
4874 ssh2_pkt_send(ssh, pktout);
4875 c->closes |= CLOSES_SENT_EOF;
4876 ssh2_channel_check_close(c);
4880 Conf *sshfwd_get_conf(struct ssh_channel *c)
4886 void sshfwd_write_eof(struct ssh_channel *c)
4890 if (ssh->state == SSH_STATE_CLOSED)
4893 if (c->closes & CLOSES_SENT_EOF)
4896 c->pending_eof = TRUE;
4897 ssh_channel_try_eof(c);
4900 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4904 if (ssh->state == SSH_STATE_CLOSED)
4909 x11_close(c->u.x11.xconn);
4910 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4914 case CHAN_SOCKDATA_DORMANT:
4915 pfd_close(c->u.pfd.pf);
4916 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4919 c->type = CHAN_ZOMBIE;
4920 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4922 ssh2_channel_check_close(c);
4925 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4929 if (ssh->state == SSH_STATE_CLOSED)
4932 if (ssh->version == 1) {
4933 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4934 PKT_INT, c->remoteid,
4935 PKT_INT, len, PKT_DATA, buf, len,
4938 * In SSH-1 we can return 0 here - implying that forwarded
4939 * connections are never individually throttled - because
4940 * the only circumstance that can cause throttling will be
4941 * the whole SSH connection backing up, in which case
4942 * _everything_ will be throttled as a whole.
4946 ssh2_add_channel_data(c, buf, len);
4947 return ssh2_try_send(c);
4951 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4956 if (ssh->state == SSH_STATE_CLOSED)
4959 if (ssh->version == 1) {
4960 buflimit = SSH1_BUFFER_LIMIT;
4962 buflimit = c->v.v2.locmaxwin;
4963 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4965 if (c->throttling_conn && bufsize <= buflimit) {
4966 c->throttling_conn = 0;
4967 ssh_throttle_conn(ssh, -1);
4971 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4973 struct queued_handler *qh = ssh->qhead;
4977 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4980 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4981 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4984 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4985 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4989 ssh->qhead = qh->next;
4991 if (ssh->qhead->msg1 > 0) {
4992 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4993 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4995 if (ssh->qhead->msg2 > 0) {
4996 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4997 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5000 ssh->qhead = ssh->qtail = NULL;
5003 qh->handler(ssh, pktin, qh->ctx);
5008 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5009 chandler_fn_t handler, void *ctx)
5011 struct queued_handler *qh;
5013 qh = snew(struct queued_handler);
5016 qh->handler = handler;
5020 if (ssh->qtail == NULL) {
5024 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5025 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5028 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5029 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5032 ssh->qtail->next = qh;
5037 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5039 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5041 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5042 SSH2_MSG_REQUEST_SUCCESS)) {
5043 logeventf(ssh, "Remote port forwarding from %s enabled",
5046 logeventf(ssh, "Remote port forwarding from %s refused",
5049 rpf = del234(ssh->rportfwds, pf);
5051 pf->pfrec->remote = NULL;
5056 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5059 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5062 pf->share_ctx = share_ctx;
5063 pf->shost = dupstr(shost);
5065 pf->sportdesc = NULL;
5066 if (!ssh->rportfwds) {
5067 assert(ssh->version == 2);
5068 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5070 if (add234(ssh->rportfwds, pf) != pf) {
5078 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5081 share_got_pkt_from_server(ctx, pktin->type,
5082 pktin->body, pktin->length);
5085 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5087 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5088 ssh_sharing_global_request_response, share_ctx);
5091 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5093 struct ssh_portfwd *epf;
5097 if (!ssh->portfwds) {
5098 ssh->portfwds = newtree234(ssh_portcmp);
5101 * Go through the existing port forwardings and tag them
5102 * with status==DESTROY. Any that we want to keep will be
5103 * re-enabled (status==KEEP) as we go through the
5104 * configuration and find out which bits are the same as
5107 struct ssh_portfwd *epf;
5109 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5110 epf->status = DESTROY;
5113 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5115 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5116 char *kp, *kp2, *vp, *vp2;
5117 char address_family, type;
5118 int sport,dport,sserv,dserv;
5119 char *sports, *dports, *saddr, *host;
5123 address_family = 'A';
5125 if (*kp == 'A' || *kp == '4' || *kp == '6')
5126 address_family = *kp++;
5127 if (*kp == 'L' || *kp == 'R')
5130 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5132 * There's a colon in the middle of the source port
5133 * string, which means that the part before it is
5134 * actually a source address.
5136 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5137 saddr = host_strduptrim(saddr_tmp);
5144 sport = atoi(sports);
5148 sport = net_service_lookup(sports);
5150 logeventf(ssh, "Service lookup failed for source"
5151 " port \"%s\"", sports);
5155 if (type == 'L' && !strcmp(val, "D")) {
5156 /* dynamic forwarding */
5163 /* ordinary forwarding */
5165 vp2 = vp + host_strcspn(vp, ":");
5166 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5170 dport = atoi(dports);
5174 dport = net_service_lookup(dports);
5176 logeventf(ssh, "Service lookup failed for destination"
5177 " port \"%s\"", dports);
5182 if (sport && dport) {
5183 /* Set up a description of the source port. */
5184 struct ssh_portfwd *pfrec, *epfrec;
5186 pfrec = snew(struct ssh_portfwd);
5188 pfrec->saddr = saddr;
5189 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5190 pfrec->sport = sport;
5191 pfrec->daddr = host;
5192 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5193 pfrec->dport = dport;
5194 pfrec->local = NULL;
5195 pfrec->remote = NULL;
5196 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5197 address_family == '6' ? ADDRTYPE_IPV6 :
5200 epfrec = add234(ssh->portfwds, pfrec);
5201 if (epfrec != pfrec) {
5202 if (epfrec->status == DESTROY) {
5204 * We already have a port forwarding up and running
5205 * with precisely these parameters. Hence, no need
5206 * to do anything; simply re-tag the existing one
5209 epfrec->status = KEEP;
5212 * Anything else indicates that there was a duplicate
5213 * in our input, which we'll silently ignore.
5215 free_portfwd(pfrec);
5217 pfrec->status = CREATE;
5226 * Now go through and destroy any port forwardings which were
5229 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5230 if (epf->status == DESTROY) {
5233 message = dupprintf("%s port forwarding from %s%s%d",
5234 epf->type == 'L' ? "local" :
5235 epf->type == 'R' ? "remote" : "dynamic",
5236 epf->saddr ? epf->saddr : "",
5237 epf->saddr ? ":" : "",
5240 if (epf->type != 'D') {
5241 char *msg2 = dupprintf("%s to %s:%d", message,
5242 epf->daddr, epf->dport);
5247 logeventf(ssh, "Cancelling %s", message);
5250 /* epf->remote or epf->local may be NULL if setting up a
5251 * forwarding failed. */
5253 struct ssh_rportfwd *rpf = epf->remote;
5254 struct Packet *pktout;
5257 * Cancel the port forwarding at the server
5260 if (ssh->version == 1) {
5262 * We cannot cancel listening ports on the
5263 * server side in SSH-1! There's no message
5264 * to support it. Instead, we simply remove
5265 * the rportfwd record from the local end
5266 * so that any connections the server tries
5267 * to make on it are rejected.
5270 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5271 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5272 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5274 ssh2_pkt_addstring(pktout, epf->saddr);
5275 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5276 /* XXX: rport_acceptall may not represent
5277 * what was used to open the original connection,
5278 * since it's reconfigurable. */
5279 ssh2_pkt_addstring(pktout, "");
5281 ssh2_pkt_addstring(pktout, "localhost");
5283 ssh2_pkt_adduint32(pktout, epf->sport);
5284 ssh2_pkt_send(ssh, pktout);
5287 del234(ssh->rportfwds, rpf);
5289 } else if (epf->local) {
5290 pfl_terminate(epf->local);
5293 delpos234(ssh->portfwds, i);
5295 i--; /* so we don't skip one in the list */
5299 * And finally, set up any new port forwardings (status==CREATE).
5301 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5302 if (epf->status == CREATE) {
5303 char *sportdesc, *dportdesc;
5304 sportdesc = dupprintf("%s%s%s%s%d%s",
5305 epf->saddr ? epf->saddr : "",
5306 epf->saddr ? ":" : "",
5307 epf->sserv ? epf->sserv : "",
5308 epf->sserv ? "(" : "",
5310 epf->sserv ? ")" : "");
5311 if (epf->type == 'D') {
5314 dportdesc = dupprintf("%s:%s%s%d%s",
5316 epf->dserv ? epf->dserv : "",
5317 epf->dserv ? "(" : "",
5319 epf->dserv ? ")" : "");
5322 if (epf->type == 'L') {
5323 char *err = pfl_listen(epf->daddr, epf->dport,
5324 epf->saddr, epf->sport,
5325 ssh, conf, &epf->local,
5326 epf->addressfamily);
5328 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5329 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5330 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5331 sportdesc, dportdesc,
5332 err ? " failed: " : "", err ? err : "");
5335 } else if (epf->type == 'D') {
5336 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5337 ssh, conf, &epf->local,
5338 epf->addressfamily);
5340 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5341 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5342 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5344 err ? " failed: " : "", err ? err : "");
5349 struct ssh_rportfwd *pf;
5352 * Ensure the remote port forwardings tree exists.
5354 if (!ssh->rportfwds) {
5355 if (ssh->version == 1)
5356 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5358 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5361 pf = snew(struct ssh_rportfwd);
5362 pf->share_ctx = NULL;
5363 pf->dhost = dupstr(epf->daddr);
5364 pf->dport = epf->dport;
5366 pf->shost = dupstr(epf->saddr);
5367 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5368 pf->shost = dupstr("");
5370 pf->shost = dupstr("localhost");
5372 pf->sport = epf->sport;
5373 if (add234(ssh->rportfwds, pf) != pf) {
5374 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5375 epf->daddr, epf->dport);
5378 logeventf(ssh, "Requesting remote port %s"
5379 " forward to %s", sportdesc, dportdesc);
5381 pf->sportdesc = sportdesc;
5386 if (ssh->version == 1) {
5387 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5388 PKT_INT, epf->sport,
5389 PKT_STR, epf->daddr,
5390 PKT_INT, epf->dport,
5392 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5394 ssh_rportfwd_succfail, pf);
5396 struct Packet *pktout;
5397 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5398 ssh2_pkt_addstring(pktout, "tcpip-forward");
5399 ssh2_pkt_addbool(pktout, 1);/* want reply */
5400 ssh2_pkt_addstring(pktout, pf->shost);
5401 ssh2_pkt_adduint32(pktout, pf->sport);
5402 ssh2_pkt_send(ssh, pktout);
5404 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5405 SSH2_MSG_REQUEST_FAILURE,
5406 ssh_rportfwd_succfail, pf);
5415 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5418 int stringlen, bufsize;
5420 ssh_pkt_getstring(pktin, &string, &stringlen);
5421 if (string == NULL) {
5422 bombout(("Incoming terminal data packet was badly formed"));
5426 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5428 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5429 ssh->v1_stdout_throttling = 1;
5430 ssh_throttle_conn(ssh, +1);
5434 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5436 /* Remote side is trying to open a channel to talk to our
5437 * X-Server. Give them back a local channel number. */
5438 struct ssh_channel *c;
5439 int remoteid = ssh_pkt_getuint32(pktin);
5441 logevent("Received X11 connect request");
5442 /* Refuse if X11 forwarding is disabled. */
5443 if (!ssh->X11_fwd_enabled) {
5444 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5445 PKT_INT, remoteid, PKT_END);
5446 logevent("Rejected X11 connect request");
5448 c = snew(struct ssh_channel);
5451 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5452 c->remoteid = remoteid;
5453 c->halfopen = FALSE;
5454 c->localid = alloc_channel_id(ssh);
5456 c->pending_eof = FALSE;
5457 c->throttling_conn = 0;
5458 c->type = CHAN_X11; /* identify channel type */
5459 add234(ssh->channels, c);
5460 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5461 PKT_INT, c->remoteid, PKT_INT,
5462 c->localid, PKT_END);
5463 logevent("Opened X11 forward channel");
5467 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5469 /* Remote side is trying to open a channel to talk to our
5470 * agent. Give them back a local channel number. */
5471 struct ssh_channel *c;
5472 int remoteid = ssh_pkt_getuint32(pktin);
5474 /* Refuse if agent forwarding is disabled. */
5475 if (!ssh->agentfwd_enabled) {
5476 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5477 PKT_INT, remoteid, PKT_END);
5479 c = snew(struct ssh_channel);
5481 c->remoteid = remoteid;
5482 c->halfopen = FALSE;
5483 c->localid = alloc_channel_id(ssh);
5485 c->pending_eof = FALSE;
5486 c->throttling_conn = 0;
5487 c->type = CHAN_AGENT; /* identify channel type */
5488 c->u.a.lensofar = 0;
5489 c->u.a.message = NULL;
5490 c->u.a.outstanding_requests = 0;
5491 add234(ssh->channels, c);
5492 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5493 PKT_INT, c->remoteid, PKT_INT, c->localid,
5498 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5500 /* Remote side is trying to open a channel to talk to a
5501 * forwarded port. Give them back a local channel number. */
5502 struct ssh_rportfwd pf, *pfp;
5508 remoteid = ssh_pkt_getuint32(pktin);
5509 ssh_pkt_getstring(pktin, &host, &hostsize);
5510 port = ssh_pkt_getuint32(pktin);
5512 pf.dhost = dupprintf("%.*s", hostsize, host);
5514 pfp = find234(ssh->rportfwds, &pf, NULL);
5517 logeventf(ssh, "Rejected remote port open request for %s:%d",
5519 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5520 PKT_INT, remoteid, PKT_END);
5522 struct ssh_channel *c = snew(struct ssh_channel);
5525 logeventf(ssh, "Received remote port open request for %s:%d",
5527 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5528 c, ssh->conf, pfp->pfrec->addressfamily);
5530 logeventf(ssh, "Port open failed: %s", err);
5533 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5534 PKT_INT, remoteid, PKT_END);
5536 c->remoteid = remoteid;
5537 c->halfopen = FALSE;
5538 c->localid = alloc_channel_id(ssh);
5540 c->pending_eof = FALSE;
5541 c->throttling_conn = 0;
5542 c->type = CHAN_SOCKDATA; /* identify channel type */
5543 add234(ssh->channels, c);
5544 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5545 PKT_INT, c->remoteid, PKT_INT,
5546 c->localid, PKT_END);
5547 logevent("Forwarded port opened successfully");
5554 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5556 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5557 unsigned int localid = ssh_pkt_getuint32(pktin);
5558 struct ssh_channel *c;
5560 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5561 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5562 c->remoteid = localid;
5563 c->halfopen = FALSE;
5564 c->type = CHAN_SOCKDATA;
5565 c->throttling_conn = 0;
5566 pfd_confirm(c->u.pfd.pf);
5569 if (c && c->pending_eof) {
5571 * We have a pending close on this channel,
5572 * which we decided on before the server acked
5573 * the channel open. So now we know the
5574 * remoteid, we can close it again.
5576 ssh_channel_try_eof(c);
5580 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5582 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5583 struct ssh_channel *c;
5585 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5586 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5587 logevent("Forwarded connection refused by server");
5588 pfd_close(c->u.pfd.pf);
5589 del234(ssh->channels, c);
5594 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5596 /* Remote side closes a channel. */
5597 unsigned i = ssh_pkt_getuint32(pktin);
5598 struct ssh_channel *c;
5599 c = find234(ssh->channels, &i, ssh_channelfind);
5600 if (c && !c->halfopen) {
5602 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5603 !(c->closes & CLOSES_RCVD_EOF)) {
5605 * Received CHANNEL_CLOSE, which we translate into
5608 int send_close = FALSE;
5610 c->closes |= CLOSES_RCVD_EOF;
5615 x11_send_eof(c->u.x11.xconn);
5621 pfd_send_eof(c->u.pfd.pf);
5630 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5631 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5633 c->closes |= CLOSES_SENT_EOF;
5637 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5638 !(c->closes & CLOSES_RCVD_CLOSE)) {
5640 if (!(c->closes & CLOSES_SENT_EOF)) {
5641 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5642 " for which we never sent CHANNEL_CLOSE\n", i));
5645 c->closes |= CLOSES_RCVD_CLOSE;
5648 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5649 !(c->closes & CLOSES_SENT_CLOSE)) {
5650 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5651 PKT_INT, c->remoteid, PKT_END);
5652 c->closes |= CLOSES_SENT_CLOSE;
5655 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5656 ssh_channel_destroy(c);
5658 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5659 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5660 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5665 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5667 /* Data sent down one of our channels. */
5668 int i = ssh_pkt_getuint32(pktin);
5671 struct ssh_channel *c;
5673 ssh_pkt_getstring(pktin, &p, &len);
5675 c = find234(ssh->channels, &i, ssh_channelfind);
5680 bufsize = x11_send(c->u.x11.xconn, p, len);
5683 bufsize = pfd_send(c->u.pfd.pf, p, len);
5686 /* Data for an agent message. Buffer it. */
5688 if (c->u.a.lensofar < 4) {
5689 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5690 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5694 c->u.a.lensofar += l;
5696 if (c->u.a.lensofar == 4) {
5698 4 + GET_32BIT(c->u.a.msglen);
5699 c->u.a.message = snewn(c->u.a.totallen,
5701 memcpy(c->u.a.message, c->u.a.msglen, 4);
5703 if (c->u.a.lensofar >= 4 && len > 0) {
5705 min(c->u.a.totallen - c->u.a.lensofar,
5707 memcpy(c->u.a.message + c->u.a.lensofar, p,
5711 c->u.a.lensofar += l;
5713 if (c->u.a.lensofar == c->u.a.totallen) {
5716 c->u.a.outstanding_requests++;
5717 if (agent_query(c->u.a.message,
5720 ssh_agentf_callback, c))
5721 ssh_agentf_callback(c, reply, replylen);
5722 sfree(c->u.a.message);
5723 c->u.a.lensofar = 0;
5726 bufsize = 0; /* agent channels never back up */
5729 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5730 c->throttling_conn = 1;
5731 ssh_throttle_conn(ssh, +1);
5736 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5738 ssh->exitcode = ssh_pkt_getuint32(pktin);
5739 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5740 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5742 * In case `helpful' firewalls or proxies tack
5743 * extra human-readable text on the end of the
5744 * session which we might mistake for another
5745 * encrypted packet, we close the session once
5746 * we've sent EXIT_CONFIRMATION.
5748 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5751 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5752 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5754 struct Packet *pktout = (struct Packet *)data;
5756 unsigned int arg = 0;
5757 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5758 if (i == lenof(ssh_ttymodes)) return;
5759 switch (ssh_ttymodes[i].type) {
5761 arg = ssh_tty_parse_specchar(val);
5764 arg = ssh_tty_parse_boolean(val);
5767 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5768 ssh2_pkt_addbyte(pktout, arg);
5771 int ssh_agent_forwarding_permitted(Ssh ssh)
5773 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5776 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5777 struct Packet *pktin)
5779 crBegin(ssh->do_ssh1_connection_crstate);
5781 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5782 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5783 ssh1_smsg_stdout_stderr_data;
5785 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5786 ssh1_msg_channel_open_confirmation;
5787 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5788 ssh1_msg_channel_open_failure;
5789 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5790 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5791 ssh1_msg_channel_close;
5792 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5793 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5795 if (ssh_agent_forwarding_permitted(ssh)) {
5796 logevent("Requesting agent forwarding");
5797 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5801 if (pktin->type != SSH1_SMSG_SUCCESS
5802 && pktin->type != SSH1_SMSG_FAILURE) {
5803 bombout(("Protocol confusion"));
5805 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5806 logevent("Agent forwarding refused");
5808 logevent("Agent forwarding enabled");
5809 ssh->agentfwd_enabled = TRUE;
5810 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5814 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5816 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5818 if (!ssh->x11disp) {
5819 /* FIXME: return an error message from x11_setup_display */
5820 logevent("X11 forwarding not enabled: unable to"
5821 " initialise X display");
5823 ssh->x11auth = x11_invent_fake_auth
5824 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5825 ssh->x11auth->disp = ssh->x11disp;
5827 logevent("Requesting X11 forwarding");
5828 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5829 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5830 PKT_STR, ssh->x11auth->protoname,
5831 PKT_STR, ssh->x11auth->datastring,
5832 PKT_INT, ssh->x11disp->screennum,
5835 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5836 PKT_STR, ssh->x11auth->protoname,
5837 PKT_STR, ssh->x11auth->datastring,
5843 if (pktin->type != SSH1_SMSG_SUCCESS
5844 && pktin->type != SSH1_SMSG_FAILURE) {
5845 bombout(("Protocol confusion"));
5847 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5848 logevent("X11 forwarding refused");
5850 logevent("X11 forwarding enabled");
5851 ssh->X11_fwd_enabled = TRUE;
5852 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5857 ssh_setup_portfwd(ssh, ssh->conf);
5858 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5860 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5862 /* Unpick the terminal-speed string. */
5863 /* XXX perhaps we should allow no speeds to be sent. */
5864 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5865 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5866 /* Send the pty request. */
5867 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5868 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5869 ssh_pkt_adduint32(pkt, ssh->term_height);
5870 ssh_pkt_adduint32(pkt, ssh->term_width);
5871 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5872 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5873 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5874 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5875 ssh_pkt_adduint32(pkt, ssh->ispeed);
5876 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5877 ssh_pkt_adduint32(pkt, ssh->ospeed);
5878 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5880 ssh->state = SSH_STATE_INTERMED;
5884 if (pktin->type != SSH1_SMSG_SUCCESS
5885 && pktin->type != SSH1_SMSG_FAILURE) {
5886 bombout(("Protocol confusion"));
5888 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5889 c_write_str(ssh, "Server refused to allocate pty\r\n");
5890 ssh->editing = ssh->echoing = 1;
5892 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5893 ssh->ospeed, ssh->ispeed);
5894 ssh->got_pty = TRUE;
5897 ssh->editing = ssh->echoing = 1;
5900 if (conf_get_int(ssh->conf, CONF_compression)) {
5901 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5905 if (pktin->type != SSH1_SMSG_SUCCESS
5906 && pktin->type != SSH1_SMSG_FAILURE) {
5907 bombout(("Protocol confusion"));
5909 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5910 c_write_str(ssh, "Server refused to compress\r\n");
5912 logevent("Started compression");
5913 ssh->v1_compressing = TRUE;
5914 ssh->cs_comp_ctx = zlib_compress_init();
5915 logevent("Initialised zlib (RFC1950) compression");
5916 ssh->sc_comp_ctx = zlib_decompress_init();
5917 logevent("Initialised zlib (RFC1950) decompression");
5921 * Start the shell or command.
5923 * Special case: if the first-choice command is an SSH-2
5924 * subsystem (hence not usable here) and the second choice
5925 * exists, we fall straight back to that.
5928 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5930 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5931 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5932 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5933 ssh->fallback_cmd = TRUE;
5936 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5938 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5939 logevent("Started session");
5942 ssh->state = SSH_STATE_SESSION;
5943 if (ssh->size_needed)
5944 ssh_size(ssh, ssh->term_width, ssh->term_height);
5945 if (ssh->eof_needed)
5946 ssh_special(ssh, TS_EOF);
5949 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
5951 ssh->channels = newtree234(ssh_channelcmp);
5955 * By this point, most incoming packets are already being
5956 * handled by the dispatch table, and we need only pay
5957 * attention to the unusual ones.
5962 if (pktin->type == SSH1_SMSG_SUCCESS) {
5963 /* may be from EXEC_SHELL on some servers */
5964 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5965 /* may be from EXEC_SHELL on some servers
5966 * if no pty is available or in other odd cases. Ignore */
5968 bombout(("Strange packet received: type %d", pktin->type));
5973 int len = min(inlen, 512);
5974 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5975 PKT_INT, len, PKT_DATA, in, len,
5987 * Handle the top-level SSH-2 protocol.
5989 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5994 ssh_pkt_getstring(pktin, &msg, &msglen);
5995 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5998 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6000 /* log reason code in disconnect message */
6004 ssh_pkt_getstring(pktin, &msg, &msglen);
6005 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
6008 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6010 /* Do nothing, because we're ignoring it! Duhh. */
6013 static void ssh1_protocol_setup(Ssh ssh)
6018 * Most messages are handled by the coroutines.
6020 for (i = 0; i < 256; i++)
6021 ssh->packet_dispatch[i] = NULL;
6024 * These special message types we install handlers for.
6026 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6027 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6028 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6031 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
6032 struct Packet *pktin)
6034 unsigned char *in=(unsigned char*)vin;
6035 if (ssh->state == SSH_STATE_CLOSED)
6038 if (pktin && ssh->packet_dispatch[pktin->type]) {
6039 ssh->packet_dispatch[pktin->type](ssh, pktin);
6043 if (!ssh->protocol_initial_phase_done) {
6044 if (do_ssh1_login(ssh, in, inlen, pktin))
6045 ssh->protocol_initial_phase_done = TRUE;
6050 do_ssh1_connection(ssh, in, inlen, pktin);
6054 * Utility routine for decoding comma-separated strings in KEXINIT.
6056 static int in_commasep_string(char const *needle, char const *haystack,
6060 if (!needle || !haystack) /* protect against null pointers */
6062 needlen = strlen(needle);
6065 * Is it at the start of the string?
6067 if (haylen >= needlen && /* haystack is long enough */
6068 !memcmp(needle, haystack, needlen) && /* initial match */
6069 (haylen == needlen || haystack[needlen] == ',')
6070 /* either , or EOS follows */
6074 * If not, search for the next comma and resume after that.
6075 * If no comma found, terminate.
6077 while (haylen > 0 && *haystack != ',')
6078 haylen--, haystack++;
6081 haylen--, haystack++; /* skip over comma itself */
6086 * Similar routine for checking whether we have the first string in a list.
6088 static int first_in_commasep_string(char const *needle, char const *haystack,
6092 if (!needle || !haystack) /* protect against null pointers */
6094 needlen = strlen(needle);
6096 * Is it at the start of the string?
6098 if (haylen >= needlen && /* haystack is long enough */
6099 !memcmp(needle, haystack, needlen) && /* initial match */
6100 (haylen == needlen || haystack[needlen] == ',')
6101 /* either , or EOS follows */
6108 * Add a value to the comma-separated string at the end of the packet.
6109 * If the value is already in the string, don't bother adding it again.
6111 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6113 if (in_commasep_string(data, (char *)pkt->data + pkt->savedpos,
6114 pkt->length - pkt->savedpos)) return;
6115 if (pkt->length - pkt->savedpos > 0)
6116 ssh_pkt_addstring_str(pkt, ",");
6117 ssh_pkt_addstring_str(pkt, data);
6122 * SSH-2 key creation method.
6123 * (Currently assumes 2 lots of any hash are sufficient to generate
6124 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
6126 #define SSH2_MKKEY_ITERS (2)
6127 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
6128 unsigned char *keyspace)
6130 const struct ssh_hash *h = ssh->kex->hash;
6132 /* First hlen bytes. */
6134 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6135 hash_mpint(h, s, K);
6136 h->bytes(s, H, h->hlen);
6137 h->bytes(s, &chr, 1);
6138 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6139 h->final(s, keyspace);
6140 /* Next hlen bytes. */
6142 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6143 hash_mpint(h, s, K);
6144 h->bytes(s, H, h->hlen);
6145 h->bytes(s, keyspace, h->hlen);
6146 h->final(s, keyspace + h->hlen);
6150 * Handle the SSH-2 transport layer.
6152 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6153 struct Packet *pktin)
6155 unsigned char *in = (unsigned char *)vin;
6156 struct do_ssh2_transport_state {
6158 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6159 Bignum p, g, e, f, K;
6162 int kex_init_value, kex_reply_value;
6163 const struct ssh_mac **maclist;
6165 const struct ssh2_cipher *cscipher_tobe;
6166 const struct ssh2_cipher *sccipher_tobe;
6167 const struct ssh_mac *csmac_tobe;
6168 const struct ssh_mac *scmac_tobe;
6169 int csmac_etm_tobe, scmac_etm_tobe;
6170 const struct ssh_compress *cscomp_tobe;
6171 const struct ssh_compress *sccomp_tobe;
6172 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6173 int hostkeylen, siglen, rsakeylen;
6174 void *hkey; /* actual host key */
6175 void *rsakey; /* for RSA kex */
6176 void *eckey; /* for ECDH kex */
6177 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6178 int n_preferred_kex;
6179 const struct ssh_kexes *preferred_kex[KEX_MAX];
6180 int n_preferred_ciphers;
6181 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6182 const struct ssh_compress *preferred_comp;
6183 int userauth_succeeded; /* for delayed compression */
6184 int pending_compression;
6185 int got_session_id, activated_authconn;
6186 struct Packet *pktout;
6191 crState(do_ssh2_transport_state);
6193 assert(!ssh->bare_connection);
6197 s->cscipher_tobe = s->sccipher_tobe = NULL;
6198 s->csmac_tobe = s->scmac_tobe = NULL;
6199 s->cscomp_tobe = s->sccomp_tobe = NULL;
6201 s->got_session_id = s->activated_authconn = FALSE;
6202 s->userauth_succeeded = FALSE;
6203 s->pending_compression = FALSE;
6206 * Be prepared to work around the buggy MAC problem.
6208 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6209 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6211 s->maclist = macs, s->nmacs = lenof(macs);
6214 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6219 * Set up the preferred key exchange. (NULL => warn below here)
6221 s->n_preferred_kex = 0;
6222 for (i = 0; i < KEX_MAX; i++) {
6223 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6225 s->preferred_kex[s->n_preferred_kex++] =
6226 &ssh_diffiehellman_gex;
6229 s->preferred_kex[s->n_preferred_kex++] =
6230 &ssh_diffiehellman_group14;
6233 s->preferred_kex[s->n_preferred_kex++] =
6234 &ssh_diffiehellman_group1;
6237 s->preferred_kex[s->n_preferred_kex++] =
6241 s->preferred_kex[s->n_preferred_kex++] =
6245 /* Flag for later. Don't bother if it's the last in
6247 if (i < KEX_MAX - 1) {
6248 s->preferred_kex[s->n_preferred_kex++] = NULL;
6255 * Set up the preferred ciphers. (NULL => warn below here)
6257 s->n_preferred_ciphers = 0;
6258 for (i = 0; i < CIPHER_MAX; i++) {
6259 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6260 case CIPHER_BLOWFISH:
6261 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6264 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6265 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6269 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6272 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6274 case CIPHER_ARCFOUR:
6275 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6278 /* Flag for later. Don't bother if it's the last in
6280 if (i < CIPHER_MAX - 1) {
6281 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6288 * Set up preferred compression.
6290 if (conf_get_int(ssh->conf, CONF_compression))
6291 s->preferred_comp = &ssh_zlib;
6293 s->preferred_comp = &ssh_comp_none;
6296 * Enable queueing of outgoing auth- or connection-layer
6297 * packets while we are in the middle of a key exchange.
6299 ssh->queueing = TRUE;
6302 * Flag that KEX is in progress.
6304 ssh->kex_in_progress = TRUE;
6307 * Construct and send our key exchange packet.
6309 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6310 for (i = 0; i < 16; i++)
6311 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6312 /* List key exchange algorithms. */
6313 ssh2_pkt_addstring_start(s->pktout);
6314 for (i = 0; i < s->n_preferred_kex; i++) {
6315 const struct ssh_kexes *k = s->preferred_kex[i];
6316 if (!k) continue; /* warning flag */
6317 for (j = 0; j < k->nkexes; j++)
6318 ssh2_pkt_addstring_commasep(s->pktout, k->list[j]->name);
6320 /* List server host key algorithms. */
6321 if (!s->got_session_id) {
6323 * In the first key exchange, we list all the algorithms
6324 * we're prepared to cope with.
6326 ssh2_pkt_addstring_start(s->pktout);
6327 for (i = 0; i < lenof(hostkey_algs); i++)
6328 ssh2_pkt_addstring_commasep(s->pktout, hostkey_algs[i]->name);
6331 * In subsequent key exchanges, we list only the kex
6332 * algorithm that was selected in the first key exchange,
6333 * so that we keep getting the same host key and hence
6334 * don't have to interrupt the user's session to ask for
6338 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6340 /* List encryption algorithms (client->server then server->client). */
6341 for (k = 0; k < 2; k++) {
6342 ssh2_pkt_addstring_start(s->pktout);
6343 for (i = 0; i < s->n_preferred_ciphers; i++) {
6344 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6345 if (!c) continue; /* warning flag */
6346 for (j = 0; j < c->nciphers; j++)
6347 ssh2_pkt_addstring_commasep(s->pktout, c->list[j]->name);
6350 /* List MAC algorithms (client->server then server->client). */
6351 for (j = 0; j < 2; j++) {
6352 ssh2_pkt_addstring_start(s->pktout);
6353 for (i = 0; i < s->nmacs; i++) {
6354 ssh2_pkt_addstring_commasep(s->pktout, s->maclist[i]->name);
6356 for (i = 0; i < s->nmacs; i++) {
6357 /* For each MAC, there may also be an ETM version,
6358 * which we list second. */
6359 if (s->maclist[i]->etm_name)
6360 ssh2_pkt_addstring_commasep(s->pktout, s->maclist[i]->etm_name);
6363 /* List client->server compression algorithms,
6364 * then server->client compression algorithms. (We use the
6365 * same set twice.) */
6366 for (j = 0; j < 2; j++) {
6367 ssh2_pkt_addstring_start(s->pktout);
6368 assert(lenof(compressions) > 1);
6369 /* Prefer non-delayed versions */
6370 ssh2_pkt_addstring_commasep(s->pktout, s->preferred_comp->name);
6371 /* We don't even list delayed versions of algorithms until
6372 * they're allowed to be used, to avoid a race. See the end of
6374 if (s->userauth_succeeded && s->preferred_comp->delayed_name)
6375 ssh2_pkt_addstring_commasep(s->pktout,
6376 s->preferred_comp->delayed_name);
6377 for (i = 0; i < lenof(compressions); i++) {
6378 const struct ssh_compress *c = compressions[i];
6379 ssh2_pkt_addstring_commasep(s->pktout, c->name);
6380 if (s->userauth_succeeded && c->delayed_name)
6381 ssh2_pkt_addstring_commasep(s->pktout, c->delayed_name);
6384 /* List client->server languages. Empty list. */
6385 ssh2_pkt_addstring_start(s->pktout);
6386 /* List server->client languages. Empty list. */
6387 ssh2_pkt_addstring_start(s->pktout);
6388 /* First KEX packet does _not_ follow, because we're not that brave. */
6389 ssh2_pkt_addbool(s->pktout, FALSE);
6391 ssh2_pkt_adduint32(s->pktout, 0);
6394 s->our_kexinitlen = s->pktout->length - 5;
6395 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6396 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6398 ssh2_pkt_send_noqueue(ssh, s->pktout);
6401 crWaitUntilV(pktin);
6404 * Now examine the other side's KEXINIT to see what we're up
6408 char *str, *preferred;
6411 if (pktin->type != SSH2_MSG_KEXINIT) {
6412 bombout(("expected key exchange packet from server"));
6416 ssh->hostkey = NULL;
6417 s->cscipher_tobe = NULL;
6418 s->sccipher_tobe = NULL;
6419 s->csmac_tobe = NULL;
6420 s->scmac_tobe = NULL;
6421 s->cscomp_tobe = NULL;
6422 s->sccomp_tobe = NULL;
6423 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6425 pktin->savedpos += 16; /* skip garbage cookie */
6426 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6428 bombout(("KEXINIT packet was incomplete"));
6433 for (i = 0; i < s->n_preferred_kex; i++) {
6434 const struct ssh_kexes *k = s->preferred_kex[i];
6438 for (j = 0; j < k->nkexes; j++) {
6439 if (!preferred) preferred = k->list[j]->name;
6440 if (in_commasep_string(k->list[j]->name, str, len)) {
6441 ssh->kex = k->list[j];
6450 bombout(("Couldn't agree a key exchange algorithm"
6451 " (available: %.*s)", len, str));
6455 * Note that the server's guess is considered wrong if it doesn't match
6456 * the first algorithm in our list, even if it's still the algorithm
6459 s->guessok = first_in_commasep_string(preferred, str, len);
6460 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6462 bombout(("KEXINIT packet was incomplete"));
6465 for (i = 0; i < lenof(hostkey_algs); i++) {
6466 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6467 ssh->hostkey = hostkey_algs[i];
6471 if (!ssh->hostkey) {
6472 bombout(("Couldn't agree a host key algorithm"
6473 " (available: %.*s)", len, str));
6477 s->guessok = s->guessok &&
6478 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6479 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6481 bombout(("KEXINIT packet was incomplete"));
6484 for (i = 0; i < s->n_preferred_ciphers; i++) {
6485 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6487 s->warn_cscipher = TRUE;
6489 for (j = 0; j < c->nciphers; j++) {
6490 if (in_commasep_string(c->list[j]->name, str, len)) {
6491 s->cscipher_tobe = c->list[j];
6496 if (s->cscipher_tobe)
6499 if (!s->cscipher_tobe) {
6500 bombout(("Couldn't agree a client-to-server cipher"
6501 " (available: %.*s)", len, str));
6505 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6507 bombout(("KEXINIT packet was incomplete"));
6510 for (i = 0; i < s->n_preferred_ciphers; i++) {
6511 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6513 s->warn_sccipher = TRUE;
6515 for (j = 0; j < c->nciphers; j++) {
6516 if (in_commasep_string(c->list[j]->name, str, len)) {
6517 s->sccipher_tobe = c->list[j];
6522 if (s->sccipher_tobe)
6525 if (!s->sccipher_tobe) {
6526 bombout(("Couldn't agree a server-to-client cipher"
6527 " (available: %.*s)", len, str));
6531 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6533 bombout(("KEXINIT packet was incomplete"));
6536 for (i = 0; i < s->nmacs; i++) {
6537 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6538 s->csmac_tobe = s->maclist[i];
6539 s->csmac_etm_tobe = FALSE;
6543 if (!s->csmac_tobe) {
6544 for (i = 0; i < s->nmacs; i++) {
6545 if (s->maclist[i]->etm_name &&
6546 in_commasep_string(s->maclist[i]->etm_name, str, len)) {
6547 s->csmac_tobe = s->maclist[i];
6548 s->csmac_etm_tobe = TRUE;
6553 if (!s->csmac_tobe) {
6554 bombout(("Couldn't agree a client-to-server MAC"
6555 " (available: %.*s)", len, str));
6558 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6560 bombout(("KEXINIT packet was incomplete"));
6563 for (i = 0; i < s->nmacs; i++) {
6564 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6565 s->scmac_tobe = s->maclist[i];
6566 s->scmac_etm_tobe = FALSE;
6570 if (!s->scmac_tobe) {
6571 for (i = 0; i < s->nmacs; i++) {
6572 if (s->maclist[i]->etm_name &&
6573 in_commasep_string(s->maclist[i]->etm_name, str, len)) {
6574 s->scmac_tobe = s->maclist[i];
6575 s->scmac_etm_tobe = TRUE;
6580 if (!s->scmac_tobe) {
6581 bombout(("Couldn't agree a server-to-client MAC"
6582 " (available: %.*s)", len, str));
6585 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6587 bombout(("KEXINIT packet was incomplete"));
6590 for (i = 0; i < lenof(compressions) + 1; i++) {
6591 const struct ssh_compress *c =
6592 i == 0 ? s->preferred_comp : compressions[i - 1];
6593 if (in_commasep_string(c->name, str, len)) {
6596 } else if (in_commasep_string(c->delayed_name, str, len)) {
6597 if (s->userauth_succeeded) {
6601 s->pending_compression = TRUE; /* try this later */
6605 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6607 bombout(("KEXINIT packet was incomplete"));
6610 for (i = 0; i < lenof(compressions) + 1; i++) {
6611 const struct ssh_compress *c =
6612 i == 0 ? s->preferred_comp : compressions[i - 1];
6613 if (in_commasep_string(c->name, str, len)) {
6616 } else if (in_commasep_string(c->delayed_name, str, len)) {
6617 if (s->userauth_succeeded) {
6621 s->pending_compression = TRUE; /* try this later */
6625 if (s->pending_compression) {
6626 logevent("Server supports delayed compression; "
6627 "will try this later");
6629 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6630 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6631 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6633 ssh->exhash = ssh->kex->hash->init();
6634 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6635 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6636 hash_string(ssh->kex->hash, ssh->exhash,
6637 s->our_kexinit, s->our_kexinitlen);
6638 sfree(s->our_kexinit);
6639 /* Include the type byte in the hash of server's KEXINIT */
6640 hash_string(ssh->kex->hash, ssh->exhash,
6641 pktin->body - 1, pktin->length + 1);
6644 ssh_set_frozen(ssh, 1);
6645 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6647 ssh_dialog_callback, ssh);
6648 if (s->dlgret < 0) {
6652 bombout(("Unexpected data from server while"
6653 " waiting for user response"));
6656 } while (pktin || inlen > 0);
6657 s->dlgret = ssh->user_response;
6659 ssh_set_frozen(ssh, 0);
6660 if (s->dlgret == 0) {
6661 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6667 if (s->warn_cscipher) {
6668 ssh_set_frozen(ssh, 1);
6669 s->dlgret = askalg(ssh->frontend,
6670 "client-to-server cipher",
6671 s->cscipher_tobe->name,
6672 ssh_dialog_callback, ssh);
6673 if (s->dlgret < 0) {
6677 bombout(("Unexpected data from server while"
6678 " waiting for user response"));
6681 } while (pktin || inlen > 0);
6682 s->dlgret = ssh->user_response;
6684 ssh_set_frozen(ssh, 0);
6685 if (s->dlgret == 0) {
6686 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6692 if (s->warn_sccipher) {
6693 ssh_set_frozen(ssh, 1);
6694 s->dlgret = askalg(ssh->frontend,
6695 "server-to-client cipher",
6696 s->sccipher_tobe->name,
6697 ssh_dialog_callback, ssh);
6698 if (s->dlgret < 0) {
6702 bombout(("Unexpected data from server while"
6703 " waiting for user response"));
6706 } while (pktin || inlen > 0);
6707 s->dlgret = ssh->user_response;
6709 ssh_set_frozen(ssh, 0);
6710 if (s->dlgret == 0) {
6711 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6717 if (s->ignorepkt) /* first_kex_packet_follows */
6718 crWaitUntilV(pktin); /* Ignore packet */
6721 if (ssh->kex->main_type == KEXTYPE_DH) {
6723 * Work out the number of bits of key we will need from the
6724 * key exchange. We start with the maximum key length of
6730 csbits = s->cscipher_tobe->keylen;
6731 scbits = s->sccipher_tobe->keylen;
6732 s->nbits = (csbits > scbits ? csbits : scbits);
6734 /* The keys only have hlen-bit entropy, since they're based on
6735 * a hash. So cap the key size at hlen bits. */
6736 if (s->nbits > ssh->kex->hash->hlen * 8)
6737 s->nbits = ssh->kex->hash->hlen * 8;
6740 * If we're doing Diffie-Hellman group exchange, start by
6741 * requesting a group.
6743 if (dh_is_gex(ssh->kex)) {
6744 logevent("Doing Diffie-Hellman group exchange");
6745 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6747 * Work out how big a DH group we will need to allow that
6750 s->pbits = 512 << ((s->nbits - 1) / 64);
6751 if (s->pbits < DH_MIN_SIZE)
6752 s->pbits = DH_MIN_SIZE;
6753 if (s->pbits > DH_MAX_SIZE)
6754 s->pbits = DH_MAX_SIZE;
6755 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6756 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6757 ssh2_pkt_adduint32(s->pktout, s->pbits);
6759 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6760 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6761 ssh2_pkt_adduint32(s->pktout, s->pbits);
6762 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6764 ssh2_pkt_send_noqueue(ssh, s->pktout);
6766 crWaitUntilV(pktin);
6767 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6768 bombout(("expected key exchange group packet from server"));
6771 s->p = ssh2_pkt_getmp(pktin);
6772 s->g = ssh2_pkt_getmp(pktin);
6773 if (!s->p || !s->g) {
6774 bombout(("unable to read mp-ints from incoming group packet"));
6777 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6778 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6779 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6781 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6782 ssh->kex_ctx = dh_setup_group(ssh->kex);
6783 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6784 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6785 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6786 ssh->kex->groupname);
6789 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6790 ssh->kex->hash->text_name);
6792 * Now generate and send e for Diffie-Hellman.
6794 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6795 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6796 s->pktout = ssh2_pkt_init(s->kex_init_value);
6797 ssh2_pkt_addmp(s->pktout, s->e);
6798 ssh2_pkt_send_noqueue(ssh, s->pktout);
6800 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6801 crWaitUntilV(pktin);
6802 if (pktin->type != s->kex_reply_value) {
6803 bombout(("expected key exchange reply packet from server"));
6806 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6807 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6808 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6809 s->hostkeydata, s->hostkeylen);
6810 s->f = ssh2_pkt_getmp(pktin);
6812 bombout(("unable to parse key exchange reply packet"));
6815 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6818 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6820 bombout(("key exchange reply failed validation: %s", err));
6824 s->K = dh_find_K(ssh->kex_ctx, s->f);
6826 /* We assume everything from now on will be quick, and it might
6827 * involve user interaction. */
6828 set_busy_status(ssh->frontend, BUSY_NOT);
6830 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6831 if (dh_is_gex(ssh->kex)) {
6832 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6833 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6834 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6835 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6836 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6837 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6838 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6840 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6841 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6843 dh_cleanup(ssh->kex_ctx);
6845 if (dh_is_gex(ssh->kex)) {
6849 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6851 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6852 ssh->kex->hash->text_name);
6853 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6855 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6857 bombout(("Unable to generate key for ECDH"));
6863 int publicPointLength;
6864 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6866 ssh_ecdhkex_freekey(s->eckey);
6867 bombout(("Unable to encode public key for ECDH"));
6870 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6871 ssh2_pkt_addstring_start(s->pktout);
6872 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6876 ssh2_pkt_send_noqueue(ssh, s->pktout);
6878 crWaitUntilV(pktin);
6879 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6880 ssh_ecdhkex_freekey(s->eckey);
6881 bombout(("expected ECDH reply packet from server"));
6885 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6886 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6887 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6888 s->hostkeydata, s->hostkeylen);
6892 int publicPointLength;
6893 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6895 ssh_ecdhkex_freekey(s->eckey);
6896 bombout(("Unable to encode public key for ECDH hash"));
6899 hash_string(ssh->kex->hash, ssh->exhash,
6900 publicPoint, publicPointLength);
6907 ssh_pkt_getstring(pktin, &keydata, &keylen);
6908 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6909 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6911 ssh_ecdhkex_freekey(s->eckey);
6912 bombout(("point received in ECDH was not valid"));
6917 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6919 ssh_ecdhkex_freekey(s->eckey);
6921 logeventf(ssh, "Doing RSA key exchange with hash %s",
6922 ssh->kex->hash->text_name);
6923 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6925 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6928 crWaitUntilV(pktin);
6929 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6930 bombout(("expected RSA public key packet from server"));
6934 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6935 hash_string(ssh->kex->hash, ssh->exhash,
6936 s->hostkeydata, s->hostkeylen);
6937 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6938 s->hostkeydata, s->hostkeylen);
6942 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6943 s->rsakeydata = snewn(s->rsakeylen, char);
6944 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6947 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6949 sfree(s->rsakeydata);
6950 bombout(("unable to parse RSA public key from server"));
6954 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6957 * Next, set up a shared secret K, of precisely KLEN -
6958 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6959 * RSA key modulus and HLEN is the bit length of the hash
6963 int klen = ssh_rsakex_klen(s->rsakey);
6964 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6966 unsigned char *kstr1, *kstr2, *outstr;
6967 int kstr1len, kstr2len, outstrlen;
6969 s->K = bn_power_2(nbits - 1);
6971 for (i = 0; i < nbits; i++) {
6973 byte = random_byte();
6975 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6979 * Encode this as an mpint.
6981 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6982 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6983 PUT_32BIT(kstr2, kstr1len);
6984 memcpy(kstr2 + 4, kstr1, kstr1len);
6987 * Encrypt it with the given RSA key.
6989 outstrlen = (klen + 7) / 8;
6990 outstr = snewn(outstrlen, unsigned char);
6991 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6992 outstr, outstrlen, s->rsakey);
6995 * And send it off in a return packet.
6997 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6998 ssh2_pkt_addstring_start(s->pktout);
6999 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7000 ssh2_pkt_send_noqueue(ssh, s->pktout);
7002 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7009 ssh_rsakex_freekey(s->rsakey);
7011 crWaitUntilV(pktin);
7012 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7013 sfree(s->rsakeydata);
7014 bombout(("expected signature packet from server"));
7018 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7020 sfree(s->rsakeydata);
7023 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7024 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7025 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7027 ssh->kex_ctx = NULL;
7030 debug(("Exchange hash is:\n"));
7031 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7035 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7036 (char *)s->exchange_hash,
7037 ssh->kex->hash->hlen)) {
7038 bombout(("Server's host key did not match the signature supplied"));
7042 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7043 if (!s->got_session_id) {
7045 * Authenticate remote host: verify host key. (We've already
7046 * checked the signature of the exchange hash.)
7048 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7049 logevent("Host key fingerprint is:");
7050 logevent(s->fingerprint);
7051 /* First check against manually configured host keys. */
7052 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7053 ssh->hostkey, s->hkey);
7054 if (s->dlgret == 0) { /* did not match */
7055 bombout(("Host key did not appear in manually configured list"));
7057 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7058 ssh_set_frozen(ssh, 1);
7059 s->dlgret = verify_ssh_host_key(ssh->frontend,
7060 ssh->savedhost, ssh->savedport,
7061 ssh->hostkey->keytype, s->keystr,
7063 ssh_dialog_callback, ssh);
7064 if (s->dlgret < 0) {
7068 bombout(("Unexpected data from server while waiting"
7069 " for user host key response"));
7072 } while (pktin || inlen > 0);
7073 s->dlgret = ssh->user_response;
7075 ssh_set_frozen(ssh, 0);
7076 if (s->dlgret == 0) {
7077 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7082 sfree(s->fingerprint);
7084 * Save this host key, to check against the one presented in
7085 * subsequent rekeys.
7087 ssh->hostkey_str = s->keystr;
7090 * In a rekey, we never present an interactive host key
7091 * verification request to the user. Instead, we simply
7092 * enforce that the key we're seeing this time is identical to
7093 * the one we saw before.
7095 if (strcmp(ssh->hostkey_str, s->keystr)) {
7096 bombout(("Host key was different in repeat key exchange"));
7101 ssh->hostkey->freekey(s->hkey);
7104 * The exchange hash from the very first key exchange is also
7105 * the session id, used in session key construction and
7108 if (!s->got_session_id) {
7109 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7110 memcpy(ssh->v2_session_id, s->exchange_hash,
7111 sizeof(s->exchange_hash));
7112 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7113 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7114 s->got_session_id = TRUE;
7118 * Send SSH2_MSG_NEWKEYS.
7120 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7121 ssh2_pkt_send_noqueue(ssh, s->pktout);
7122 ssh->outgoing_data_size = 0; /* start counting from here */
7125 * We've sent client NEWKEYS, so create and initialise
7126 * client-to-server session keys.
7128 if (ssh->cs_cipher_ctx)
7129 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7130 ssh->cscipher = s->cscipher_tobe;
7131 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7133 if (ssh->cs_mac_ctx)
7134 ssh->csmac->free_context(ssh->cs_mac_ctx);
7135 ssh->csmac = s->csmac_tobe;
7136 ssh->csmac_etm = s->csmac_etm_tobe;
7137 ssh->cs_mac_ctx = ssh->csmac->make_context();
7139 if (ssh->cs_comp_ctx)
7140 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7141 ssh->cscomp = s->cscomp_tobe;
7142 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7145 * Set IVs on client-to-server keys. Here we use the exchange
7146 * hash from the _first_ key exchange.
7149 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7150 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7151 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
7152 assert((ssh->cscipher->keylen+7) / 8 <=
7153 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7154 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
7155 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
7156 assert(ssh->cscipher->blksize <=
7157 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7158 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
7159 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
7160 assert(ssh->csmac->len <=
7161 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7162 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
7163 smemclr(keyspace, sizeof(keyspace));
7166 logeventf(ssh, "Initialised %.200s client->server encryption",
7167 ssh->cscipher->text_name);
7168 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s",
7169 ssh->csmac->text_name,
7170 ssh->csmac_etm ? " (in ETM mode)" : "");
7171 if (ssh->cscomp->text_name)
7172 logeventf(ssh, "Initialised %s compression",
7173 ssh->cscomp->text_name);
7176 * Now our end of the key exchange is complete, we can send all
7177 * our queued higher-layer packets.
7179 ssh->queueing = FALSE;
7180 ssh2_pkt_queuesend(ssh);
7183 * Expect SSH2_MSG_NEWKEYS from server.
7185 crWaitUntilV(pktin);
7186 if (pktin->type != SSH2_MSG_NEWKEYS) {
7187 bombout(("expected new-keys packet from server"));
7190 ssh->incoming_data_size = 0; /* start counting from here */
7193 * We've seen server NEWKEYS, so create and initialise
7194 * server-to-client session keys.
7196 if (ssh->sc_cipher_ctx)
7197 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7198 ssh->sccipher = s->sccipher_tobe;
7199 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7201 if (ssh->sc_mac_ctx)
7202 ssh->scmac->free_context(ssh->sc_mac_ctx);
7203 ssh->scmac = s->scmac_tobe;
7204 ssh->scmac_etm = s->scmac_etm_tobe;
7205 ssh->sc_mac_ctx = ssh->scmac->make_context();
7207 if (ssh->sc_comp_ctx)
7208 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7209 ssh->sccomp = s->sccomp_tobe;
7210 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7213 * Set IVs on server-to-client keys. Here we use the exchange
7214 * hash from the _first_ key exchange.
7217 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7218 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7219 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7220 assert((ssh->sccipher->keylen+7) / 8 <=
7221 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7222 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7223 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7224 assert(ssh->sccipher->blksize <=
7225 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7226 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7227 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7228 assert(ssh->scmac->len <=
7229 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7230 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7231 smemclr(keyspace, sizeof(keyspace));
7233 logeventf(ssh, "Initialised %.200s server->client encryption",
7234 ssh->sccipher->text_name);
7235 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s",
7236 ssh->scmac->text_name,
7237 ssh->scmac_etm ? " (in ETM mode)" : "");
7238 if (ssh->sccomp->text_name)
7239 logeventf(ssh, "Initialised %s decompression",
7240 ssh->sccomp->text_name);
7243 * Free shared secret.
7248 * Key exchange is over. Loop straight back round if we have a
7249 * deferred rekey reason.
7251 if (ssh->deferred_rekey_reason) {
7252 logevent(ssh->deferred_rekey_reason);
7254 ssh->deferred_rekey_reason = NULL;
7255 goto begin_key_exchange;
7259 * Otherwise, schedule a timer for our next rekey.
7261 ssh->kex_in_progress = FALSE;
7262 ssh->last_rekey = GETTICKCOUNT();
7263 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7264 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7268 * Now we're encrypting. Begin returning 1 to the protocol main
7269 * function so that other things can run on top of the
7270 * transport. If we ever see a KEXINIT, we must go back to the
7273 * We _also_ go back to the start if we see pktin==NULL and
7274 * inlen negative, because this is a special signal meaning
7275 * `initiate client-driven rekey', and `in' contains a message
7276 * giving the reason for the rekey.
7278 * inlen==-1 means always initiate a rekey;
7279 * inlen==-2 means that userauth has completed successfully and
7280 * we should consider rekeying (for delayed compression).
7282 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7283 (!pktin && inlen < 0))) {
7285 if (!ssh->protocol_initial_phase_done) {
7286 ssh->protocol_initial_phase_done = TRUE;
7288 * Allow authconn to initialise itself.
7290 do_ssh2_authconn(ssh, NULL, 0, NULL);
7295 logevent("Server initiated key re-exchange");
7299 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7300 * delayed compression, if it's available.
7302 * draft-miller-secsh-compression-delayed-00 says that you
7303 * negotiate delayed compression in the first key exchange, and
7304 * both sides start compressing when the server has sent
7305 * USERAUTH_SUCCESS. This has a race condition -- the server
7306 * can't know when the client has seen it, and thus which incoming
7307 * packets it should treat as compressed.
7309 * Instead, we do the initial key exchange without offering the
7310 * delayed methods, but note if the server offers them; when we
7311 * get here, if a delayed method was available that was higher
7312 * on our list than what we got, we initiate a rekey in which we
7313 * _do_ list the delayed methods (and hopefully get it as a
7314 * result). Subsequent rekeys will do the same.
7316 assert(!s->userauth_succeeded); /* should only happen once */
7317 s->userauth_succeeded = TRUE;
7318 if (!s->pending_compression)
7319 /* Can't see any point rekeying. */
7320 goto wait_for_rekey; /* this is utterly horrid */
7321 /* else fall through to rekey... */
7322 s->pending_compression = FALSE;
7325 * Now we've decided to rekey.
7327 * Special case: if the server bug is set that doesn't
7328 * allow rekeying, we give a different log message and
7329 * continue waiting. (If such a server _initiates_ a rekey,
7330 * we process it anyway!)
7332 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7333 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7335 /* Reset the counters, so that at least this message doesn't
7336 * hit the event log _too_ often. */
7337 ssh->outgoing_data_size = 0;
7338 ssh->incoming_data_size = 0;
7339 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7341 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7344 goto wait_for_rekey; /* this is still utterly horrid */
7346 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7349 goto begin_key_exchange;
7355 * Add data to an SSH-2 channel output buffer.
7357 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7360 bufchain_add(&c->v.v2.outbuffer, buf, len);
7364 * Attempt to send data on an SSH-2 channel.
7366 static int ssh2_try_send(struct ssh_channel *c)
7369 struct Packet *pktout;
7372 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7375 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7376 if ((unsigned)len > c->v.v2.remwindow)
7377 len = c->v.v2.remwindow;
7378 if ((unsigned)len > c->v.v2.remmaxpkt)
7379 len = c->v.v2.remmaxpkt;
7380 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7381 ssh2_pkt_adduint32(pktout, c->remoteid);
7382 ssh2_pkt_addstring_start(pktout);
7383 ssh2_pkt_addstring_data(pktout, data, len);
7384 ssh2_pkt_send(ssh, pktout);
7385 bufchain_consume(&c->v.v2.outbuffer, len);
7386 c->v.v2.remwindow -= len;
7390 * After having sent as much data as we can, return the amount
7393 ret = bufchain_size(&c->v.v2.outbuffer);
7396 * And if there's no data pending but we need to send an EOF, send
7399 if (!ret && c->pending_eof)
7400 ssh_channel_try_eof(c);
7405 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7408 if (c->closes & CLOSES_SENT_EOF)
7409 return; /* don't send on channels we've EOFed */
7410 bufsize = ssh2_try_send(c);
7413 case CHAN_MAINSESSION:
7414 /* stdin need not receive an unthrottle
7415 * notification since it will be polled */
7418 x11_unthrottle(c->u.x11.xconn);
7421 /* agent sockets are request/response and need no
7422 * buffer management */
7425 pfd_unthrottle(c->u.pfd.pf);
7431 static int ssh_is_simple(Ssh ssh)
7434 * We use the 'simple' variant of the SSH protocol if we're asked
7435 * to, except not if we're also doing connection-sharing (either
7436 * tunnelling our packets over an upstream or expecting to be
7437 * tunnelled over ourselves), since then the assumption that we
7438 * have only one channel to worry about is not true after all.
7440 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7441 !ssh->bare_connection && !ssh->connshare);
7445 * Set up most of a new ssh_channel for SSH-2.
7447 static void ssh2_channel_init(struct ssh_channel *c)
7450 c->localid = alloc_channel_id(ssh);
7452 c->pending_eof = FALSE;
7453 c->throttling_conn = FALSE;
7454 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7455 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7456 c->v.v2.chanreq_head = NULL;
7457 c->v.v2.throttle_state = UNTHROTTLED;
7458 bufchain_init(&c->v.v2.outbuffer);
7462 * Construct the common parts of a CHANNEL_OPEN.
7464 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7466 struct Packet *pktout;
7468 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7469 ssh2_pkt_addstring(pktout, type);
7470 ssh2_pkt_adduint32(pktout, c->localid);
7471 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7472 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7477 * CHANNEL_FAILURE doesn't come with any indication of what message
7478 * caused it, so we have to keep track of the outstanding
7479 * CHANNEL_REQUESTs ourselves.
7481 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7482 cchandler_fn_t handler, void *ctx)
7484 struct outstanding_channel_request *ocr =
7485 snew(struct outstanding_channel_request);
7487 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7488 ocr->handler = handler;
7491 if (!c->v.v2.chanreq_head)
7492 c->v.v2.chanreq_head = ocr;
7494 c->v.v2.chanreq_tail->next = ocr;
7495 c->v.v2.chanreq_tail = ocr;
7499 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7500 * NULL then a reply will be requested and the handler will be called
7501 * when it arrives. The returned packet is ready to have any
7502 * request-specific data added and be sent. Note that if a handler is
7503 * provided, it's essential that the request actually be sent.
7505 * The handler will usually be passed the response packet in pktin. If
7506 * pktin is NULL, this means that no reply will ever be forthcoming
7507 * (e.g. because the entire connection is being destroyed, or because
7508 * the server initiated channel closure before we saw the response)
7509 * and the handler should free any storage it's holding.
7511 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7512 cchandler_fn_t handler, void *ctx)
7514 struct Packet *pktout;
7516 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7517 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7518 ssh2_pkt_adduint32(pktout, c->remoteid);
7519 ssh2_pkt_addstring(pktout, type);
7520 ssh2_pkt_addbool(pktout, handler != NULL);
7521 if (handler != NULL)
7522 ssh2_queue_chanreq_handler(c, handler, ctx);
7527 * Potentially enlarge the window on an SSH-2 channel.
7529 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7531 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7536 * Never send WINDOW_ADJUST for a channel that the remote side has
7537 * already sent EOF on; there's no point, since it won't be
7538 * sending any more data anyway. Ditto if _we've_ already sent
7541 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7545 * Also, never widen the window for an X11 channel when we're
7546 * still waiting to see its initial auth and may yet hand it off
7549 if (c->type == CHAN_X11 && c->u.x11.initial)
7553 * If the remote end has a habit of ignoring maxpkt, limit the
7554 * window so that it has no choice (assuming it doesn't ignore the
7557 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7558 newwin = OUR_V2_MAXPKT;
7561 * Only send a WINDOW_ADJUST if there's significantly more window
7562 * available than the other end thinks there is. This saves us
7563 * sending a WINDOW_ADJUST for every character in a shell session.
7565 * "Significant" is arbitrarily defined as half the window size.
7567 if (newwin / 2 >= c->v.v2.locwindow) {
7568 struct Packet *pktout;
7572 * In order to keep track of how much window the client
7573 * actually has available, we'd like it to acknowledge each
7574 * WINDOW_ADJUST. We can't do that directly, so we accompany
7575 * it with a CHANNEL_REQUEST that has to be acknowledged.
7577 * This is only necessary if we're opening the window wide.
7578 * If we're not, then throughput is being constrained by
7579 * something other than the maximum window size anyway.
7581 if (newwin == c->v.v2.locmaxwin &&
7582 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7583 up = snew(unsigned);
7584 *up = newwin - c->v.v2.locwindow;
7585 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7586 ssh2_handle_winadj_response, up);
7587 ssh2_pkt_send(ssh, pktout);
7589 if (c->v.v2.throttle_state != UNTHROTTLED)
7590 c->v.v2.throttle_state = UNTHROTTLING;
7592 /* Pretend the WINDOW_ADJUST was acked immediately. */
7593 c->v.v2.remlocwin = newwin;
7594 c->v.v2.throttle_state = THROTTLED;
7596 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7597 ssh2_pkt_adduint32(pktout, c->remoteid);
7598 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7599 ssh2_pkt_send(ssh, pktout);
7600 c->v.v2.locwindow = newwin;
7605 * Find the channel associated with a message. If there's no channel,
7606 * or it's not properly open, make a noise about it and return NULL.
7608 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7610 unsigned localid = ssh_pkt_getuint32(pktin);
7611 struct ssh_channel *c;
7613 c = find234(ssh->channels, &localid, ssh_channelfind);
7615 (c->type != CHAN_SHARING && c->halfopen &&
7616 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7617 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7618 char *buf = dupprintf("Received %s for %s channel %u",
7619 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7621 c ? "half-open" : "nonexistent", localid);
7622 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7629 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7630 struct Packet *pktin, void *ctx)
7632 unsigned *sizep = ctx;
7635 * Winadj responses should always be failures. However, at least
7636 * one server ("boks_sshd") is known to return SUCCESS for channel
7637 * requests it's never heard of, such as "winadj@putty". Raised
7638 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7639 * life, we don't worry about what kind of response we got.
7642 c->v.v2.remlocwin += *sizep;
7645 * winadj messages are only sent when the window is fully open, so
7646 * if we get an ack of one, we know any pending unthrottle is
7649 if (c->v.v2.throttle_state == UNTHROTTLING)
7650 c->v.v2.throttle_state = UNTHROTTLED;
7653 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7655 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7656 struct outstanding_channel_request *ocr;
7659 if (c->type == CHAN_SHARING) {
7660 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7661 pktin->body, pktin->length);
7664 ocr = c->v.v2.chanreq_head;
7666 ssh2_msg_unexpected(ssh, pktin);
7669 ocr->handler(c, pktin, ocr->ctx);
7670 c->v.v2.chanreq_head = ocr->next;
7673 * We may now initiate channel-closing procedures, if that
7674 * CHANNEL_REQUEST was the last thing outstanding before we send
7677 ssh2_channel_check_close(c);
7680 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7682 struct ssh_channel *c;
7683 c = ssh2_channel_msg(ssh, pktin);
7686 if (c->type == CHAN_SHARING) {
7687 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7688 pktin->body, pktin->length);
7691 if (!(c->closes & CLOSES_SENT_EOF)) {
7692 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7693 ssh2_try_send_and_unthrottle(ssh, c);
7697 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7701 struct ssh_channel *c;
7702 c = ssh2_channel_msg(ssh, pktin);
7705 if (c->type == CHAN_SHARING) {
7706 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7707 pktin->body, pktin->length);
7710 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7711 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7712 return; /* extended but not stderr */
7713 ssh_pkt_getstring(pktin, &data, &length);
7716 c->v.v2.locwindow -= length;
7717 c->v.v2.remlocwin -= length;
7719 case CHAN_MAINSESSION:
7721 from_backend(ssh->frontend, pktin->type ==
7722 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7726 bufsize = x11_send(c->u.x11.xconn, data, length);
7729 bufsize = pfd_send(c->u.pfd.pf, data, length);
7732 while (length > 0) {
7733 if (c->u.a.lensofar < 4) {
7734 unsigned int l = min(4 - c->u.a.lensofar,
7736 memcpy(c->u.a.msglen + c->u.a.lensofar,
7740 c->u.a.lensofar += l;
7742 if (c->u.a.lensofar == 4) {
7744 4 + GET_32BIT(c->u.a.msglen);
7745 c->u.a.message = snewn(c->u.a.totallen,
7747 memcpy(c->u.a.message, c->u.a.msglen, 4);
7749 if (c->u.a.lensofar >= 4 && length > 0) {
7751 min(c->u.a.totallen - c->u.a.lensofar,
7753 memcpy(c->u.a.message + c->u.a.lensofar,
7757 c->u.a.lensofar += l;
7759 if (c->u.a.lensofar == c->u.a.totallen) {
7762 c->u.a.outstanding_requests++;
7763 if (agent_query(c->u.a.message,
7766 ssh_agentf_callback, c))
7767 ssh_agentf_callback(c, reply, replylen);
7768 sfree(c->u.a.message);
7769 c->u.a.message = NULL;
7770 c->u.a.lensofar = 0;
7777 * If it looks like the remote end hit the end of its window,
7778 * and we didn't want it to do that, think about using a
7781 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7782 c->v.v2.locmaxwin < 0x40000000)
7783 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7785 * If we are not buffering too much data,
7786 * enlarge the window again at the remote side.
7787 * If we are buffering too much, we may still
7788 * need to adjust the window if the server's
7791 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7792 c->v.v2.locmaxwin - bufsize : 0);
7794 * If we're either buffering way too much data, or if we're
7795 * buffering anything at all and we're in "simple" mode,
7796 * throttle the whole channel.
7798 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7799 && !c->throttling_conn) {
7800 c->throttling_conn = 1;
7801 ssh_throttle_conn(ssh, +1);
7806 static void ssh_check_termination(Ssh ssh)
7808 if (ssh->version == 2 &&
7809 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7810 count234(ssh->channels) == 0 &&
7811 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7813 * We used to send SSH_MSG_DISCONNECT here, because I'd
7814 * believed that _every_ conforming SSH-2 connection had to
7815 * end with a disconnect being sent by at least one side;
7816 * apparently I was wrong and it's perfectly OK to
7817 * unceremoniously slam the connection shut when you're done,
7818 * and indeed OpenSSH feels this is more polite than sending a
7819 * DISCONNECT. So now we don't.
7821 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7825 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7827 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7830 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7832 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7833 ssh_check_termination(ssh);
7836 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7841 va_start(ap, logfmt);
7842 buf = dupvprintf(logfmt, ap);
7845 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7847 logeventf(ssh, "Connection sharing: %s", buf);
7851 static void ssh_channel_destroy(struct ssh_channel *c)
7856 case CHAN_MAINSESSION:
7857 ssh->mainchan = NULL;
7858 update_specials_menu(ssh->frontend);
7861 if (c->u.x11.xconn != NULL)
7862 x11_close(c->u.x11.xconn);
7863 logevent("Forwarded X11 connection terminated");
7866 sfree(c->u.a.message);
7869 if (c->u.pfd.pf != NULL)
7870 pfd_close(c->u.pfd.pf);
7871 logevent("Forwarded port closed");
7875 del234(ssh->channels, c);
7876 if (ssh->version == 2) {
7877 bufchain_clear(&c->v.v2.outbuffer);
7878 assert(c->v.v2.chanreq_head == NULL);
7883 * If that was the last channel left open, we might need to
7886 ssh_check_termination(ssh);
7889 static void ssh2_channel_check_close(struct ssh_channel *c)
7892 struct Packet *pktout;
7896 * If we've sent out our own CHANNEL_OPEN but not yet seen
7897 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7898 * it's too early to be sending close messages of any kind.
7903 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7904 c->type == CHAN_ZOMBIE) &&
7905 !c->v.v2.chanreq_head &&
7906 !(c->closes & CLOSES_SENT_CLOSE)) {
7908 * We have both sent and received EOF (or the channel is a
7909 * zombie), and we have no outstanding channel requests, which
7910 * means the channel is in final wind-up. But we haven't sent
7911 * CLOSE, so let's do so now.
7913 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7914 ssh2_pkt_adduint32(pktout, c->remoteid);
7915 ssh2_pkt_send(ssh, pktout);
7916 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7919 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7920 assert(c->v.v2.chanreq_head == NULL);
7922 * We have both sent and received CLOSE, which means we're
7923 * completely done with the channel.
7925 ssh_channel_destroy(c);
7929 static void ssh2_channel_got_eof(struct ssh_channel *c)
7931 if (c->closes & CLOSES_RCVD_EOF)
7932 return; /* already seen EOF */
7933 c->closes |= CLOSES_RCVD_EOF;
7935 if (c->type == CHAN_X11) {
7936 x11_send_eof(c->u.x11.xconn);
7937 } else if (c->type == CHAN_AGENT) {
7938 if (c->u.a.outstanding_requests == 0) {
7939 /* Manufacture an outgoing EOF in response to the incoming one. */
7940 sshfwd_write_eof(c);
7942 } else if (c->type == CHAN_SOCKDATA) {
7943 pfd_send_eof(c->u.pfd.pf);
7944 } else if (c->type == CHAN_MAINSESSION) {
7947 if (!ssh->sent_console_eof &&
7948 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7950 * Either from_backend_eof told us that the front end
7951 * wants us to close the outgoing side of the connection
7952 * as soon as we see EOF from the far end, or else we've
7953 * unilaterally decided to do that because we've allocated
7954 * a remote pty and hence EOF isn't a particularly
7955 * meaningful concept.
7957 sshfwd_write_eof(c);
7959 ssh->sent_console_eof = TRUE;
7962 ssh2_channel_check_close(c);
7965 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7967 struct ssh_channel *c;
7969 c = ssh2_channel_msg(ssh, pktin);
7972 if (c->type == CHAN_SHARING) {
7973 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7974 pktin->body, pktin->length);
7977 ssh2_channel_got_eof(c);
7980 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7982 struct ssh_channel *c;
7984 c = ssh2_channel_msg(ssh, pktin);
7987 if (c->type == CHAN_SHARING) {
7988 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7989 pktin->body, pktin->length);
7994 * When we receive CLOSE on a channel, we assume it comes with an
7995 * implied EOF if we haven't seen EOF yet.
7997 ssh2_channel_got_eof(c);
7999 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8001 * It also means we stop expecting to see replies to any
8002 * outstanding channel requests, so clean those up too.
8003 * (ssh_chanreq_init will enforce by assertion that we don't
8004 * subsequently put anything back on this list.)
8006 while (c->v.v2.chanreq_head) {
8007 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8008 ocr->handler(c, NULL, ocr->ctx);
8009 c->v.v2.chanreq_head = ocr->next;
8015 * And we also send an outgoing EOF, if we haven't already, on the
8016 * assumption that CLOSE is a pretty forceful announcement that
8017 * the remote side is doing away with the entire channel. (If it
8018 * had wanted to send us EOF and continue receiving data from us,
8019 * it would have just sent CHANNEL_EOF.)
8021 if (!(c->closes & CLOSES_SENT_EOF)) {
8023 * Make sure we don't read any more from whatever our local
8024 * data source is for this channel.
8027 case CHAN_MAINSESSION:
8028 ssh->send_ok = 0; /* stop trying to read from stdin */
8031 x11_override_throttle(c->u.x11.xconn, 1);
8034 pfd_override_throttle(c->u.pfd.pf, 1);
8039 * Abandon any buffered data we still wanted to send to this
8040 * channel. Receiving a CHANNEL_CLOSE is an indication that
8041 * the server really wants to get on and _destroy_ this
8042 * channel, and it isn't going to send us any further
8043 * WINDOW_ADJUSTs to permit us to send pending stuff.
8045 bufchain_clear(&c->v.v2.outbuffer);
8048 * Send outgoing EOF.
8050 sshfwd_write_eof(c);
8054 * Now process the actual close.
8056 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8057 c->closes |= CLOSES_RCVD_CLOSE;
8058 ssh2_channel_check_close(c);
8062 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8064 struct ssh_channel *c;
8066 c = ssh2_channel_msg(ssh, pktin);
8069 if (c->type == CHAN_SHARING) {
8070 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8071 pktin->body, pktin->length);
8074 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8075 c->remoteid = ssh_pkt_getuint32(pktin);
8076 c->halfopen = FALSE;
8077 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8078 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8080 if (c->type == CHAN_SOCKDATA_DORMANT) {
8081 c->type = CHAN_SOCKDATA;
8083 pfd_confirm(c->u.pfd.pf);
8084 } else if (c->type == CHAN_ZOMBIE) {
8086 * This case can occur if a local socket error occurred
8087 * between us sending out CHANNEL_OPEN and receiving
8088 * OPEN_CONFIRMATION. In this case, all we can do is
8089 * immediately initiate close proceedings now that we know the
8090 * server's id to put in the close message.
8092 ssh2_channel_check_close(c);
8095 * We never expect to receive OPEN_CONFIRMATION for any
8096 * *other* channel type (since only local-to-remote port
8097 * forwardings cause us to send CHANNEL_OPEN after the main
8098 * channel is live - all other auxiliary channel types are
8099 * initiated from the server end). It's safe to enforce this
8100 * by assertion rather than by ssh_disconnect, because the
8101 * real point is that we never constructed a half-open channel
8102 * structure in the first place with any type other than the
8105 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8109 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8112 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8114 static const char *const reasons[] = {
8115 "<unknown reason code>",
8116 "Administratively prohibited",
8118 "Unknown channel type",
8119 "Resource shortage",
8121 unsigned reason_code;
8122 char *reason_string;
8124 struct ssh_channel *c;
8126 c = ssh2_channel_msg(ssh, pktin);
8129 if (c->type == CHAN_SHARING) {
8130 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8131 pktin->body, pktin->length);
8134 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8136 if (c->type == CHAN_SOCKDATA_DORMANT) {
8137 reason_code = ssh_pkt_getuint32(pktin);
8138 if (reason_code >= lenof(reasons))
8139 reason_code = 0; /* ensure reasons[reason_code] in range */
8140 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8141 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8142 reasons[reason_code], reason_length, reason_string);
8144 pfd_close(c->u.pfd.pf);
8145 } else if (c->type == CHAN_ZOMBIE) {
8147 * This case can occur if a local socket error occurred
8148 * between us sending out CHANNEL_OPEN and receiving
8149 * OPEN_FAILURE. In this case, we need do nothing except allow
8150 * the code below to throw the half-open channel away.
8154 * We never expect to receive OPEN_FAILURE for any *other*
8155 * channel type (since only local-to-remote port forwardings
8156 * cause us to send CHANNEL_OPEN after the main channel is
8157 * live - all other auxiliary channel types are initiated from
8158 * the server end). It's safe to enforce this by assertion
8159 * rather than by ssh_disconnect, because the real point is
8160 * that we never constructed a half-open channel structure in
8161 * the first place with any type other than the above.
8163 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8166 del234(ssh->channels, c);
8170 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8173 int typelen, want_reply;
8174 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8175 struct ssh_channel *c;
8176 struct Packet *pktout;
8178 c = ssh2_channel_msg(ssh, pktin);
8181 if (c->type == CHAN_SHARING) {
8182 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8183 pktin->body, pktin->length);
8186 ssh_pkt_getstring(pktin, &type, &typelen);
8187 want_reply = ssh2_pkt_getbool(pktin);
8189 if (c->closes & CLOSES_SENT_CLOSE) {
8191 * We don't reply to channel requests after we've sent
8192 * CHANNEL_CLOSE for the channel, because our reply might
8193 * cross in the network with the other side's CHANNEL_CLOSE
8194 * and arrive after they have wound the channel up completely.
8200 * Having got the channel number, we now look at
8201 * the request type string to see if it's something
8204 if (c == ssh->mainchan) {
8206 * We recognise "exit-status" and "exit-signal" on
8207 * the primary channel.
8209 if (typelen == 11 &&
8210 !memcmp(type, "exit-status", 11)) {
8212 ssh->exitcode = ssh_pkt_getuint32(pktin);
8213 logeventf(ssh, "Server sent command exit status %d",
8215 reply = SSH2_MSG_CHANNEL_SUCCESS;
8217 } else if (typelen == 11 &&
8218 !memcmp(type, "exit-signal", 11)) {
8220 int is_plausible = TRUE, is_int = FALSE;
8221 char *fmt_sig = "", *fmt_msg = "";
8223 int msglen = 0, core = FALSE;
8224 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8225 * provide an `int' for the signal, despite its
8226 * having been a `string' in the drafts of RFC 4254 since at
8227 * least 2001. (Fixed in session.c 1.147.) Try to
8228 * infer which we can safely parse it as. */
8230 unsigned char *p = pktin->body +
8232 long len = pktin->length - pktin->savedpos;
8233 unsigned long num = GET_32BIT(p); /* what is it? */
8234 /* If it's 0, it hardly matters; assume string */
8238 int maybe_int = FALSE, maybe_str = FALSE;
8239 #define CHECK_HYPOTHESIS(offset, result) \
8242 int q = toint(offset); \
8243 if (q >= 0 && q+4 <= len) { \
8244 q = toint(q + 4 + GET_32BIT(p+q)); \
8245 if (q >= 0 && q+4 <= len && \
8246 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8251 CHECK_HYPOTHESIS(4+1, maybe_int);
8252 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8253 #undef CHECK_HYPOTHESIS
8254 if (maybe_int && !maybe_str)
8256 else if (!maybe_int && maybe_str)
8259 /* Crikey. Either or neither. Panic. */
8260 is_plausible = FALSE;
8263 ssh->exitcode = 128; /* means `unknown signal' */
8266 /* Old non-standard OpenSSH. */
8267 int signum = ssh_pkt_getuint32(pktin);
8268 fmt_sig = dupprintf(" %d", signum);
8269 ssh->exitcode = 128 + signum;
8271 /* As per RFC 4254. */
8274 ssh_pkt_getstring(pktin, &sig, &siglen);
8275 /* Signal name isn't supposed to be blank, but
8276 * let's cope gracefully if it is. */
8278 fmt_sig = dupprintf(" \"%.*s\"",
8283 * Really hideous method of translating the
8284 * signal description back into a locally
8285 * meaningful number.
8290 #define TRANSLATE_SIGNAL(s) \
8291 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8292 ssh->exitcode = 128 + SIG ## s
8294 TRANSLATE_SIGNAL(ABRT);
8297 TRANSLATE_SIGNAL(ALRM);
8300 TRANSLATE_SIGNAL(FPE);
8303 TRANSLATE_SIGNAL(HUP);
8306 TRANSLATE_SIGNAL(ILL);
8309 TRANSLATE_SIGNAL(INT);
8312 TRANSLATE_SIGNAL(KILL);
8315 TRANSLATE_SIGNAL(PIPE);
8318 TRANSLATE_SIGNAL(QUIT);
8321 TRANSLATE_SIGNAL(SEGV);
8324 TRANSLATE_SIGNAL(TERM);
8327 TRANSLATE_SIGNAL(USR1);
8330 TRANSLATE_SIGNAL(USR2);
8332 #undef TRANSLATE_SIGNAL
8334 ssh->exitcode = 128;
8336 core = ssh2_pkt_getbool(pktin);
8337 ssh_pkt_getstring(pktin, &msg, &msglen);
8339 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8341 /* ignore lang tag */
8342 } /* else don't attempt to parse */
8343 logeventf(ssh, "Server exited on signal%s%s%s",
8344 fmt_sig, core ? " (core dumped)" : "",
8346 if (*fmt_sig) sfree(fmt_sig);
8347 if (*fmt_msg) sfree(fmt_msg);
8348 reply = SSH2_MSG_CHANNEL_SUCCESS;
8353 * This is a channel request we don't know
8354 * about, so we now either ignore the request
8355 * or respond with CHANNEL_FAILURE, depending
8358 reply = SSH2_MSG_CHANNEL_FAILURE;
8361 pktout = ssh2_pkt_init(reply);
8362 ssh2_pkt_adduint32(pktout, c->remoteid);
8363 ssh2_pkt_send(ssh, pktout);
8367 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8370 int typelen, want_reply;
8371 struct Packet *pktout;
8373 ssh_pkt_getstring(pktin, &type, &typelen);
8374 want_reply = ssh2_pkt_getbool(pktin);
8377 * We currently don't support any global requests
8378 * at all, so we either ignore the request or
8379 * respond with REQUEST_FAILURE, depending on
8383 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8384 ssh2_pkt_send(ssh, pktout);
8388 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8392 struct X11FakeAuth *auth;
8395 * Make up a new set of fake X11 auth data, and add it to the tree
8396 * of currently valid ones with an indication of the sharing
8397 * context that it's relevant to.
8399 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8400 auth->share_cs = share_cs;
8401 auth->share_chan = share_chan;
8406 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8408 del234(ssh->x11authtree, auth);
8409 x11_free_fake_auth(auth);
8412 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8420 struct ssh_channel *c;
8421 unsigned remid, winsize, pktsize;
8422 unsigned our_winsize_override = 0;
8423 struct Packet *pktout;
8425 ssh_pkt_getstring(pktin, &type, &typelen);
8426 c = snew(struct ssh_channel);
8429 remid = ssh_pkt_getuint32(pktin);
8430 winsize = ssh_pkt_getuint32(pktin);
8431 pktsize = ssh_pkt_getuint32(pktin);
8433 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8436 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8437 addrstr = snewn(peeraddrlen+1, char);
8438 memcpy(addrstr, peeraddr, peeraddrlen);
8439 addrstr[peeraddrlen] = '\0';
8440 peerport = ssh_pkt_getuint32(pktin);
8442 logeventf(ssh, "Received X11 connect request from %s:%d",
8445 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8446 error = "X11 forwarding is not enabled";
8448 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8451 c->u.x11.initial = TRUE;
8454 * If we are a connection-sharing upstream, then we should
8455 * initially present a very small window, adequate to take
8456 * the X11 initial authorisation packet but not much more.
8457 * Downstream will then present us a larger window (by
8458 * fiat of the connection-sharing protocol) and we can
8459 * guarantee to send a positive-valued WINDOW_ADJUST.
8462 our_winsize_override = 128;
8464 logevent("Opened X11 forward channel");
8468 } else if (typelen == 15 &&
8469 !memcmp(type, "forwarded-tcpip", 15)) {
8470 struct ssh_rportfwd pf, *realpf;
8473 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8474 pf.shost = dupprintf("%.*s", shostlen, shost);
8475 pf.sport = ssh_pkt_getuint32(pktin);
8476 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8477 peerport = ssh_pkt_getuint32(pktin);
8478 realpf = find234(ssh->rportfwds, &pf, NULL);
8479 logeventf(ssh, "Received remote port %s:%d open request "
8480 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8483 if (realpf == NULL) {
8484 error = "Remote port is not recognised";
8488 if (realpf->share_ctx) {
8490 * This port forwarding is on behalf of a
8491 * connection-sharing downstream, so abandon our own
8492 * channel-open procedure and just pass the message on
8495 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8496 pktin->body, pktin->length);
8501 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8502 c, ssh->conf, realpf->pfrec->addressfamily);
8503 logeventf(ssh, "Attempting to forward remote port to "
8504 "%s:%d", realpf->dhost, realpf->dport);
8506 logeventf(ssh, "Port open failed: %s", err);
8508 error = "Port open failed";
8510 logevent("Forwarded port opened successfully");
8511 c->type = CHAN_SOCKDATA;
8514 } else if (typelen == 22 &&
8515 !memcmp(type, "auth-agent@openssh.com", 22)) {
8516 if (!ssh->agentfwd_enabled)
8517 error = "Agent forwarding is not enabled";
8519 c->type = CHAN_AGENT; /* identify channel type */
8520 c->u.a.lensofar = 0;
8521 c->u.a.message = NULL;
8522 c->u.a.outstanding_requests = 0;
8525 error = "Unsupported channel type requested";
8528 c->remoteid = remid;
8529 c->halfopen = FALSE;
8531 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8532 ssh2_pkt_adduint32(pktout, c->remoteid);
8533 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8534 ssh2_pkt_addstring(pktout, error);
8535 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8536 ssh2_pkt_send(ssh, pktout);
8537 logeventf(ssh, "Rejected channel open: %s", error);
8540 ssh2_channel_init(c);
8541 c->v.v2.remwindow = winsize;
8542 c->v.v2.remmaxpkt = pktsize;
8543 if (our_winsize_override) {
8544 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8545 our_winsize_override;
8547 add234(ssh->channels, c);
8548 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8549 ssh2_pkt_adduint32(pktout, c->remoteid);
8550 ssh2_pkt_adduint32(pktout, c->localid);
8551 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8552 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8553 ssh2_pkt_send(ssh, pktout);
8557 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8558 void *share_cs, void *share_chan,
8559 const char *peer_addr, int peer_port,
8560 int endian, int protomajor, int protominor,
8561 const void *initial_data, int initial_len)
8564 * This function is called when we've just discovered that an X
8565 * forwarding channel on which we'd been handling the initial auth
8566 * ourselves turns out to be destined for a connection-sharing
8567 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8568 * that we completely stop tracking windows and buffering data and
8569 * just pass more or less unmodified SSH messages back and forth.
8571 c->type = CHAN_SHARING;
8572 c->u.sharing.ctx = share_cs;
8573 share_setup_x11_channel(share_cs, share_chan,
8574 c->localid, c->remoteid, c->v.v2.remwindow,
8575 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8576 peer_addr, peer_port, endian,
8577 protomajor, protominor,
8578 initial_data, initial_len);
8581 void sshfwd_x11_is_local(struct ssh_channel *c)
8584 * This function is called when we've just discovered that an X
8585 * forwarding channel is _not_ destined for a connection-sharing
8586 * downstream but we're going to handle it ourselves. We stop
8587 * presenting a cautiously small window and go into ordinary data
8590 c->u.x11.initial = FALSE;
8591 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8595 * Buffer banner messages for later display at some convenient point,
8596 * if we're going to display them.
8598 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8600 /* Arbitrary limit to prevent unbounded inflation of buffer */
8601 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8602 bufchain_size(&ssh->banner) <= 131072) {
8603 char *banner = NULL;
8605 ssh_pkt_getstring(pktin, &banner, &size);
8607 bufchain_add(&ssh->banner, banner, size);
8611 /* Helper function to deal with sending tty modes for "pty-req" */
8612 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8614 struct Packet *pktout = (struct Packet *)data;
8616 unsigned int arg = 0;
8617 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8618 if (i == lenof(ssh_ttymodes)) return;
8619 switch (ssh_ttymodes[i].type) {
8621 arg = ssh_tty_parse_specchar(val);
8624 arg = ssh_tty_parse_boolean(val);
8627 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8628 ssh2_pkt_adduint32(pktout, arg);
8631 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8634 struct ssh2_setup_x11_state {
8638 struct Packet *pktout;
8639 crStateP(ssh2_setup_x11_state, ctx);
8643 logevent("Requesting X11 forwarding");
8644 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8646 ssh2_pkt_addbool(pktout, 0); /* many connections */
8647 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8648 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8649 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8650 ssh2_pkt_send(ssh, pktout);
8652 /* Wait to be called back with either a response packet, or NULL
8653 * meaning clean up and free our data */
8657 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8658 logevent("X11 forwarding enabled");
8659 ssh->X11_fwd_enabled = TRUE;
8661 logevent("X11 forwarding refused");
8667 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8670 struct ssh2_setup_agent_state {
8674 struct Packet *pktout;
8675 crStateP(ssh2_setup_agent_state, ctx);
8679 logevent("Requesting OpenSSH-style agent forwarding");
8680 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8681 ssh2_setup_agent, s);
8682 ssh2_pkt_send(ssh, pktout);
8684 /* Wait to be called back with either a response packet, or NULL
8685 * meaning clean up and free our data */
8689 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8690 logevent("Agent forwarding enabled");
8691 ssh->agentfwd_enabled = TRUE;
8693 logevent("Agent forwarding refused");
8699 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8702 struct ssh2_setup_pty_state {
8706 struct Packet *pktout;
8707 crStateP(ssh2_setup_pty_state, ctx);
8711 /* Unpick the terminal-speed string. */
8712 /* XXX perhaps we should allow no speeds to be sent. */
8713 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8714 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8715 /* Build the pty request. */
8716 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8718 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8719 ssh2_pkt_adduint32(pktout, ssh->term_width);
8720 ssh2_pkt_adduint32(pktout, ssh->term_height);
8721 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8722 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8723 ssh2_pkt_addstring_start(pktout);
8724 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8725 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8726 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8727 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8728 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8729 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8730 ssh2_pkt_send(ssh, pktout);
8731 ssh->state = SSH_STATE_INTERMED;
8733 /* Wait to be called back with either a response packet, or NULL
8734 * meaning clean up and free our data */
8738 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8739 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8740 ssh->ospeed, ssh->ispeed);
8741 ssh->got_pty = TRUE;
8743 c_write_str(ssh, "Server refused to allocate pty\r\n");
8744 ssh->editing = ssh->echoing = 1;
8751 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8754 struct ssh2_setup_env_state {
8756 int num_env, env_left, env_ok;
8759 struct Packet *pktout;
8760 crStateP(ssh2_setup_env_state, ctx);
8765 * Send environment variables.
8767 * Simplest thing here is to send all the requests at once, and
8768 * then wait for a whole bunch of successes or failures.
8774 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8776 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8777 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8778 ssh2_pkt_addstring(pktout, key);
8779 ssh2_pkt_addstring(pktout, val);
8780 ssh2_pkt_send(ssh, pktout);
8785 logeventf(ssh, "Sent %d environment variables", s->num_env);
8790 s->env_left = s->num_env;
8792 while (s->env_left > 0) {
8793 /* Wait to be called back with either a response packet,
8794 * or NULL meaning clean up and free our data */
8796 if (!pktin) goto out;
8797 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8802 if (s->env_ok == s->num_env) {
8803 logevent("All environment variables successfully set");
8804 } else if (s->env_ok == 0) {
8805 logevent("All environment variables refused");
8806 c_write_str(ssh, "Server refused to set environment variables\r\n");
8808 logeventf(ssh, "%d environment variables refused",
8809 s->num_env - s->env_ok);
8810 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8818 * Handle the SSH-2 userauth and connection layers.
8820 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8822 do_ssh2_authconn(ssh, NULL, 0, pktin);
8825 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8829 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8832 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8833 struct Packet *pktin)
8835 struct do_ssh2_authconn_state {
8839 AUTH_TYPE_PUBLICKEY,
8840 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8841 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8843 AUTH_TYPE_GSSAPI, /* always QUIET */
8844 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8845 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8847 int done_service_req;
8848 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8849 int tried_pubkey_config, done_agent;
8854 int kbd_inter_refused;
8855 int we_are_in, userauth_success;
8856 prompts_t *cur_prompt;
8861 void *publickey_blob;
8862 int publickey_bloblen;
8863 int privatekey_available, privatekey_encrypted;
8864 char *publickey_algorithm;
8865 char *publickey_comment;
8866 unsigned char agent_request[5], *agent_response, *agentp;
8867 int agent_responselen;
8868 unsigned char *pkblob_in_agent;
8870 char *pkblob, *alg, *commentp;
8871 int pklen, alglen, commentlen;
8872 int siglen, retlen, len;
8873 char *q, *agentreq, *ret;
8875 struct Packet *pktout;
8878 struct ssh_gss_library *gsslib;
8879 Ssh_gss_ctx gss_ctx;
8880 Ssh_gss_buf gss_buf;
8881 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8882 Ssh_gss_name gss_srv_name;
8883 Ssh_gss_stat gss_stat;
8886 crState(do_ssh2_authconn_state);
8890 /* Register as a handler for all the messages this coroutine handles. */
8891 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8892 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8893 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8894 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8895 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8896 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8897 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8898 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8899 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8900 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8901 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8902 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8903 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8904 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8905 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8906 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8907 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8908 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8909 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8910 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8912 s->done_service_req = FALSE;
8913 s->we_are_in = s->userauth_success = FALSE;
8914 s->agent_response = NULL;
8916 s->tried_gssapi = FALSE;
8919 if (!ssh->bare_connection) {
8920 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8922 * Request userauth protocol, and await a response to it.
8924 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8925 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8926 ssh2_pkt_send(ssh, s->pktout);
8927 crWaitUntilV(pktin);
8928 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8929 s->done_service_req = TRUE;
8931 if (!s->done_service_req) {
8933 * Request connection protocol directly, without authentication.
8935 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8936 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8937 ssh2_pkt_send(ssh, s->pktout);
8938 crWaitUntilV(pktin);
8939 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8940 s->we_are_in = TRUE; /* no auth required */
8942 bombout(("Server refused service request"));
8947 s->we_are_in = TRUE;
8950 /* Arrange to be able to deal with any BANNERs that come in.
8951 * (We do this now as packets may come in during the next bit.) */
8952 bufchain_init(&ssh->banner);
8953 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8954 ssh2_msg_userauth_banner;
8957 * Misc one-time setup for authentication.
8959 s->publickey_blob = NULL;
8960 if (!s->we_are_in) {
8963 * Load the public half of any configured public key file
8966 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8967 if (!filename_is_null(s->keyfile)) {
8969 logeventf(ssh, "Reading key file \"%.150s\"",
8970 filename_to_str(s->keyfile));
8971 keytype = key_type(s->keyfile);
8972 if (keytype == SSH_KEYTYPE_SSH2 ||
8973 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
8974 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
8977 ssh2_userkey_loadpub(s->keyfile,
8978 &s->publickey_algorithm,
8979 &s->publickey_bloblen,
8980 &s->publickey_comment, &error);
8981 if (s->publickey_blob) {
8982 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
8983 if (!s->privatekey_available)
8984 logeventf(ssh, "Key file contains public key only");
8985 s->privatekey_encrypted =
8986 ssh2_userkey_encrypted(s->keyfile, NULL);
8989 logeventf(ssh, "Unable to load key (%s)",
8991 msgbuf = dupprintf("Unable to load key file "
8992 "\"%.150s\" (%s)\r\n",
8993 filename_to_str(s->keyfile),
8995 c_write_str(ssh, msgbuf);
9000 logeventf(ssh, "Unable to use this key file (%s)",
9001 key_type_to_str(keytype));
9002 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9004 filename_to_str(s->keyfile),
9005 key_type_to_str(keytype));
9006 c_write_str(ssh, msgbuf);
9008 s->publickey_blob = NULL;
9013 * Find out about any keys Pageant has (but if there's a
9014 * public key configured, filter out all others).
9017 s->agent_response = NULL;
9018 s->pkblob_in_agent = NULL;
9019 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9023 logevent("Pageant is running. Requesting keys.");
9025 /* Request the keys held by the agent. */
9026 PUT_32BIT(s->agent_request, 1);
9027 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9028 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9029 ssh_agent_callback, ssh)) {
9033 bombout(("Unexpected data from server while"
9034 " waiting for agent response"));
9037 } while (pktin || inlen > 0);
9038 r = ssh->agent_response;
9039 s->agent_responselen = ssh->agent_response_len;
9041 s->agent_response = (unsigned char *) r;
9042 if (s->agent_response && s->agent_responselen >= 5 &&
9043 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9046 p = s->agent_response + 5;
9047 s->nkeys = toint(GET_32BIT(p));
9050 * Vet the Pageant response to ensure that the key
9051 * count and blob lengths make sense.
9054 logeventf(ssh, "Pageant response contained a negative"
9055 " key count %d", s->nkeys);
9057 goto done_agent_query;
9059 unsigned char *q = p + 4;
9060 int lenleft = s->agent_responselen - 5 - 4;
9062 for (keyi = 0; keyi < s->nkeys; keyi++) {
9063 int bloblen, commentlen;
9065 logeventf(ssh, "Pageant response was truncated");
9067 goto done_agent_query;
9069 bloblen = toint(GET_32BIT(q));
9070 if (bloblen < 0 || bloblen > lenleft) {
9071 logeventf(ssh, "Pageant response was truncated");
9073 goto done_agent_query;
9075 lenleft -= 4 + bloblen;
9077 commentlen = toint(GET_32BIT(q));
9078 if (commentlen < 0 || commentlen > lenleft) {
9079 logeventf(ssh, "Pageant response was truncated");
9081 goto done_agent_query;
9083 lenleft -= 4 + commentlen;
9084 q += 4 + commentlen;
9089 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9090 if (s->publickey_blob) {
9091 /* See if configured key is in agent. */
9092 for (keyi = 0; keyi < s->nkeys; keyi++) {
9093 s->pklen = toint(GET_32BIT(p));
9094 if (s->pklen == s->publickey_bloblen &&
9095 !memcmp(p+4, s->publickey_blob,
9096 s->publickey_bloblen)) {
9097 logeventf(ssh, "Pageant key #%d matches "
9098 "configured key file", keyi);
9100 s->pkblob_in_agent = p;
9104 p += toint(GET_32BIT(p)) + 4; /* comment */
9106 if (!s->pkblob_in_agent) {
9107 logevent("Configured key file not in Pageant");
9112 logevent("Failed to get reply from Pageant");
9120 * We repeat this whole loop, including the username prompt,
9121 * until we manage a successful authentication. If the user
9122 * types the wrong _password_, they can be sent back to the
9123 * beginning to try another username, if this is configured on.
9124 * (If they specify a username in the config, they are never
9125 * asked, even if they do give a wrong password.)
9127 * I think this best serves the needs of
9129 * - the people who have no configuration, no keys, and just
9130 * want to try repeated (username,password) pairs until they
9131 * type both correctly
9133 * - people who have keys and configuration but occasionally
9134 * need to fall back to passwords
9136 * - people with a key held in Pageant, who might not have
9137 * logged in to a particular machine before; so they want to
9138 * type a username, and then _either_ their key will be
9139 * accepted, _or_ they will type a password. If they mistype
9140 * the username they will want to be able to get back and
9143 s->got_username = FALSE;
9144 while (!s->we_are_in) {
9148 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9150 * We got a username last time round this loop, and
9151 * with change_username turned off we don't try to get
9154 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9155 int ret; /* need not be kept over crReturn */
9156 s->cur_prompt = new_prompts(ssh->frontend);
9157 s->cur_prompt->to_server = TRUE;
9158 s->cur_prompt->name = dupstr("SSH login name");
9159 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9160 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9163 crWaitUntilV(!pktin);
9164 ret = get_userpass_input(s->cur_prompt, in, inlen);
9169 * get_userpass_input() failed to get a username.
9172 free_prompts(s->cur_prompt);
9173 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9176 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9177 free_prompts(s->cur_prompt);
9180 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9181 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9182 c_write_str(ssh, stuff);
9186 s->got_username = TRUE;
9189 * Send an authentication request using method "none": (a)
9190 * just in case it succeeds, and (b) so that we know what
9191 * authentication methods we can usefully try next.
9193 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9195 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9196 ssh2_pkt_addstring(s->pktout, ssh->username);
9197 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9198 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9199 ssh2_pkt_send(ssh, s->pktout);
9200 s->type = AUTH_TYPE_NONE;
9202 s->we_are_in = FALSE;
9204 s->tried_pubkey_config = FALSE;
9205 s->kbd_inter_refused = FALSE;
9207 /* Reset agent request state. */
9208 s->done_agent = FALSE;
9209 if (s->agent_response) {
9210 if (s->pkblob_in_agent) {
9211 s->agentp = s->pkblob_in_agent;
9213 s->agentp = s->agent_response + 5 + 4;
9219 char *methods = NULL;
9223 * Wait for the result of the last authentication request.
9226 crWaitUntilV(pktin);
9228 * Now is a convenient point to spew any banner material
9229 * that we've accumulated. (This should ensure that when
9230 * we exit the auth loop, we haven't any left to deal
9234 int size = bufchain_size(&ssh->banner);
9236 * Don't show the banner if we're operating in
9237 * non-verbose non-interactive mode. (It's probably
9238 * a script, which means nobody will read the
9239 * banner _anyway_, and moreover the printing of
9240 * the banner will screw up processing on the
9241 * output of (say) plink.)
9243 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9244 char *banner = snewn(size, char);
9245 bufchain_fetch(&ssh->banner, banner, size);
9246 c_write_untrusted(ssh, banner, size);
9249 bufchain_clear(&ssh->banner);
9251 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9252 logevent("Access granted");
9253 s->we_are_in = s->userauth_success = TRUE;
9257 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9258 bombout(("Strange packet received during authentication: "
9259 "type %d", pktin->type));
9266 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9267 * we can look at the string in it and know what we can
9268 * helpfully try next.
9270 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9271 ssh_pkt_getstring(pktin, &methods, &methlen);
9272 if (!ssh2_pkt_getbool(pktin)) {
9274 * We have received an unequivocal Access
9275 * Denied. This can translate to a variety of
9276 * messages, or no message at all.
9278 * For forms of authentication which are attempted
9279 * implicitly, by which I mean without printing
9280 * anything in the window indicating that we're
9281 * trying them, we should never print 'Access
9284 * If we do print a message saying that we're
9285 * attempting some kind of authentication, it's OK
9286 * to print a followup message saying it failed -
9287 * but the message may sometimes be more specific
9288 * than simply 'Access denied'.
9290 * Additionally, if we'd just tried password
9291 * authentication, we should break out of this
9292 * whole loop so as to go back to the username
9293 * prompt (iff we're configured to allow
9294 * username change attempts).
9296 if (s->type == AUTH_TYPE_NONE) {
9298 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9299 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9300 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9301 c_write_str(ssh, "Server refused our key\r\n");
9302 logevent("Server refused our key");
9303 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9304 /* This _shouldn't_ happen except by a
9305 * protocol bug causing client and server to
9306 * disagree on what is a correct signature. */
9307 c_write_str(ssh, "Server refused public-key signature"
9308 " despite accepting key!\r\n");
9309 logevent("Server refused public-key signature"
9310 " despite accepting key!");
9311 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9312 /* quiet, so no c_write */
9313 logevent("Server refused keyboard-interactive authentication");
9314 } else if (s->type==AUTH_TYPE_GSSAPI) {
9315 /* always quiet, so no c_write */
9316 /* also, the code down in the GSSAPI block has
9317 * already logged this in the Event Log */
9318 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9319 logevent("Keyboard-interactive authentication failed");
9320 c_write_str(ssh, "Access denied\r\n");
9322 assert(s->type == AUTH_TYPE_PASSWORD);
9323 logevent("Password authentication failed");
9324 c_write_str(ssh, "Access denied\r\n");
9326 if (conf_get_int(ssh->conf, CONF_change_username)) {
9327 /* XXX perhaps we should allow
9328 * keyboard-interactive to do this too? */
9329 s->we_are_in = FALSE;
9334 c_write_str(ssh, "Further authentication required\r\n");
9335 logevent("Further authentication required");
9339 in_commasep_string("publickey", methods, methlen);
9341 in_commasep_string("password", methods, methlen);
9342 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9343 in_commasep_string("keyboard-interactive", methods, methlen);
9346 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9347 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9348 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9349 ssh->gsslibs->nlibraries > 0;
9353 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9355 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9358 * Attempt public-key authentication using a key from Pageant.
9361 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9363 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9365 /* Unpack key from agent response */
9366 s->pklen = toint(GET_32BIT(s->agentp));
9368 s->pkblob = (char *)s->agentp;
9369 s->agentp += s->pklen;
9370 s->alglen = toint(GET_32BIT(s->pkblob));
9371 s->alg = s->pkblob + 4;
9372 s->commentlen = toint(GET_32BIT(s->agentp));
9374 s->commentp = (char *)s->agentp;
9375 s->agentp += s->commentlen;
9376 /* s->agentp now points at next key, if any */
9378 /* See if server will accept it */
9379 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9380 ssh2_pkt_addstring(s->pktout, ssh->username);
9381 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9382 /* service requested */
9383 ssh2_pkt_addstring(s->pktout, "publickey");
9385 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9386 ssh2_pkt_addstring_start(s->pktout);
9387 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9388 ssh2_pkt_addstring_start(s->pktout);
9389 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9390 ssh2_pkt_send(ssh, s->pktout);
9391 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9393 crWaitUntilV(pktin);
9394 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9396 /* Offer of key refused. */
9403 if (flags & FLAG_VERBOSE) {
9404 c_write_str(ssh, "Authenticating with "
9406 c_write(ssh, s->commentp, s->commentlen);
9407 c_write_str(ssh, "\" from agent\r\n");
9411 * Server is willing to accept the key.
9412 * Construct a SIGN_REQUEST.
9414 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9415 ssh2_pkt_addstring(s->pktout, ssh->username);
9416 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9417 /* service requested */
9418 ssh2_pkt_addstring(s->pktout, "publickey");
9420 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9421 ssh2_pkt_addstring_start(s->pktout);
9422 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9423 ssh2_pkt_addstring_start(s->pktout);
9424 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9426 /* Ask agent for signature. */
9427 s->siglen = s->pktout->length - 5 + 4 +
9428 ssh->v2_session_id_len;
9429 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9431 s->len = 1; /* message type */
9432 s->len += 4 + s->pklen; /* key blob */
9433 s->len += 4 + s->siglen; /* data to sign */
9434 s->len += 4; /* flags */
9435 s->agentreq = snewn(4 + s->len, char);
9436 PUT_32BIT(s->agentreq, s->len);
9437 s->q = s->agentreq + 4;
9438 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9439 PUT_32BIT(s->q, s->pklen);
9441 memcpy(s->q, s->pkblob, s->pklen);
9443 PUT_32BIT(s->q, s->siglen);
9445 /* Now the data to be signed... */
9446 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9447 PUT_32BIT(s->q, ssh->v2_session_id_len);
9450 memcpy(s->q, ssh->v2_session_id,
9451 ssh->v2_session_id_len);
9452 s->q += ssh->v2_session_id_len;
9453 memcpy(s->q, s->pktout->data + 5,
9454 s->pktout->length - 5);
9455 s->q += s->pktout->length - 5;
9456 /* And finally the (zero) flags word. */
9458 if (!agent_query(s->agentreq, s->len + 4,
9460 ssh_agent_callback, ssh)) {
9464 bombout(("Unexpected data from server"
9465 " while waiting for agent"
9469 } while (pktin || inlen > 0);
9470 vret = ssh->agent_response;
9471 s->retlen = ssh->agent_response_len;
9476 if (s->retlen >= 9 &&
9477 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9478 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9479 logevent("Sending Pageant's response");
9480 ssh2_add_sigblob(ssh, s->pktout,
9481 s->pkblob, s->pklen,
9483 GET_32BIT(s->ret + 5));
9484 ssh2_pkt_send(ssh, s->pktout);
9485 s->type = AUTH_TYPE_PUBLICKEY;
9487 /* FIXME: less drastic response */
9488 bombout(("Pageant failed to answer challenge"));
9494 /* Do we have any keys left to try? */
9495 if (s->pkblob_in_agent) {
9496 s->done_agent = TRUE;
9497 s->tried_pubkey_config = TRUE;
9500 if (s->keyi >= s->nkeys)
9501 s->done_agent = TRUE;
9504 } else if (s->can_pubkey && s->publickey_blob &&
9505 s->privatekey_available && !s->tried_pubkey_config) {
9507 struct ssh2_userkey *key; /* not live over crReturn */
9508 char *passphrase; /* not live over crReturn */
9510 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9512 s->tried_pubkey_config = TRUE;
9515 * Try the public key supplied in the configuration.
9517 * First, offer the public blob to see if the server is
9518 * willing to accept it.
9520 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9521 ssh2_pkt_addstring(s->pktout, ssh->username);
9522 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9523 /* service requested */
9524 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9525 ssh2_pkt_addbool(s->pktout, FALSE);
9526 /* no signature included */
9527 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9528 ssh2_pkt_addstring_start(s->pktout);
9529 ssh2_pkt_addstring_data(s->pktout,
9530 (char *)s->publickey_blob,
9531 s->publickey_bloblen);
9532 ssh2_pkt_send(ssh, s->pktout);
9533 logevent("Offered public key");
9535 crWaitUntilV(pktin);
9536 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9537 /* Key refused. Give up. */
9538 s->gotit = TRUE; /* reconsider message next loop */
9539 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9540 continue; /* process this new message */
9542 logevent("Offer of public key accepted");
9545 * Actually attempt a serious authentication using
9548 if (flags & FLAG_VERBOSE) {
9549 c_write_str(ssh, "Authenticating with public key \"");
9550 c_write_str(ssh, s->publickey_comment);
9551 c_write_str(ssh, "\"\r\n");
9555 const char *error; /* not live over crReturn */
9556 if (s->privatekey_encrypted) {
9558 * Get a passphrase from the user.
9560 int ret; /* need not be kept over crReturn */
9561 s->cur_prompt = new_prompts(ssh->frontend);
9562 s->cur_prompt->to_server = FALSE;
9563 s->cur_prompt->name = dupstr("SSH key passphrase");
9564 add_prompt(s->cur_prompt,
9565 dupprintf("Passphrase for key \"%.100s\": ",
9566 s->publickey_comment),
9568 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9571 crWaitUntilV(!pktin);
9572 ret = get_userpass_input(s->cur_prompt,
9577 /* Failed to get a passphrase. Terminate. */
9578 free_prompts(s->cur_prompt);
9579 ssh_disconnect(ssh, NULL,
9580 "Unable to authenticate",
9581 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9586 dupstr(s->cur_prompt->prompts[0]->result);
9587 free_prompts(s->cur_prompt);
9589 passphrase = NULL; /* no passphrase needed */
9593 * Try decrypting the key.
9595 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9596 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9598 /* burn the evidence */
9599 smemclr(passphrase, strlen(passphrase));
9602 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9604 (key == SSH2_WRONG_PASSPHRASE)) {
9605 c_write_str(ssh, "Wrong passphrase\r\n");
9607 /* and loop again */
9609 c_write_str(ssh, "Unable to load private key (");
9610 c_write_str(ssh, error);
9611 c_write_str(ssh, ")\r\n");
9613 break; /* try something else */
9619 unsigned char *pkblob, *sigblob, *sigdata;
9620 int pkblob_len, sigblob_len, sigdata_len;
9624 * We have loaded the private key and the server
9625 * has announced that it's willing to accept it.
9626 * Hallelujah. Generate a signature and send it.
9628 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9629 ssh2_pkt_addstring(s->pktout, ssh->username);
9630 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9631 /* service requested */
9632 ssh2_pkt_addstring(s->pktout, "publickey");
9634 ssh2_pkt_addbool(s->pktout, TRUE);
9635 /* signature follows */
9636 ssh2_pkt_addstring(s->pktout, key->alg->name);
9637 pkblob = key->alg->public_blob(key->data,
9639 ssh2_pkt_addstring_start(s->pktout);
9640 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9644 * The data to be signed is:
9648 * followed by everything so far placed in the
9651 sigdata_len = s->pktout->length - 5 + 4 +
9652 ssh->v2_session_id_len;
9653 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9655 sigdata = snewn(sigdata_len, unsigned char);
9657 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9658 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9661 memcpy(sigdata+p, ssh->v2_session_id,
9662 ssh->v2_session_id_len);
9663 p += ssh->v2_session_id_len;
9664 memcpy(sigdata+p, s->pktout->data + 5,
9665 s->pktout->length - 5);
9666 p += s->pktout->length - 5;
9667 assert(p == sigdata_len);
9668 sigblob = key->alg->sign(key->data, (char *)sigdata,
9669 sigdata_len, &sigblob_len);
9670 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9671 sigblob, sigblob_len);
9676 ssh2_pkt_send(ssh, s->pktout);
9677 logevent("Sent public key signature");
9678 s->type = AUTH_TYPE_PUBLICKEY;
9679 key->alg->freekey(key->data);
9680 sfree(key->comment);
9685 } else if (s->can_gssapi && !s->tried_gssapi) {
9687 /* GSSAPI Authentication */
9692 s->type = AUTH_TYPE_GSSAPI;
9693 s->tried_gssapi = TRUE;
9695 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9698 * Pick the highest GSS library on the preference
9704 for (i = 0; i < ngsslibs; i++) {
9705 int want_id = conf_get_int_int(ssh->conf,
9706 CONF_ssh_gsslist, i);
9707 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9708 if (ssh->gsslibs->libraries[j].id == want_id) {
9709 s->gsslib = &ssh->gsslibs->libraries[j];
9710 goto got_gsslib; /* double break */
9715 * We always expect to have found something in
9716 * the above loop: we only came here if there
9717 * was at least one viable GSS library, and the
9718 * preference list should always mention
9719 * everything and only change the order.
9724 if (s->gsslib->gsslogmsg)
9725 logevent(s->gsslib->gsslogmsg);
9727 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9728 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9729 ssh2_pkt_addstring(s->pktout, ssh->username);
9730 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9731 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9732 logevent("Attempting GSSAPI authentication");
9734 /* add mechanism info */
9735 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9737 /* number of GSSAPI mechanisms */
9738 ssh2_pkt_adduint32(s->pktout,1);
9740 /* length of OID + 2 */
9741 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9742 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9745 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9747 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9749 ssh2_pkt_send(ssh, s->pktout);
9750 crWaitUntilV(pktin);
9751 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9752 logevent("GSSAPI authentication request refused");
9756 /* check returned packet ... */
9758 ssh_pkt_getstring(pktin, &data, &len);
9759 s->gss_rcvtok.value = data;
9760 s->gss_rcvtok.length = len;
9761 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9762 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9763 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9764 memcmp((char *)s->gss_rcvtok.value + 2,
9765 s->gss_buf.value,s->gss_buf.length) ) {
9766 logevent("GSSAPI authentication - wrong response from server");
9770 /* now start running */
9771 s->gss_stat = s->gsslib->import_name(s->gsslib,
9774 if (s->gss_stat != SSH_GSS_OK) {
9775 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9776 logevent("GSSAPI import name failed - Bad service name");
9778 logevent("GSSAPI import name failed");
9782 /* fetch TGT into GSS engine */
9783 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9785 if (s->gss_stat != SSH_GSS_OK) {
9786 logevent("GSSAPI authentication failed to get credentials");
9787 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9791 /* initial tokens are empty */
9792 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9793 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9795 /* now enter the loop */
9797 s->gss_stat = s->gsslib->init_sec_context
9801 conf_get_int(ssh->conf, CONF_gssapifwd),
9805 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9806 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9807 logevent("GSSAPI authentication initialisation failed");
9809 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9810 &s->gss_buf) == SSH_GSS_OK) {
9811 logevent(s->gss_buf.value);
9812 sfree(s->gss_buf.value);
9817 logevent("GSSAPI authentication initialised");
9819 /* Client and server now exchange tokens until GSSAPI
9820 * no longer says CONTINUE_NEEDED */
9822 if (s->gss_sndtok.length != 0) {
9823 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9824 ssh_pkt_addstring_start(s->pktout);
9825 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9826 ssh2_pkt_send(ssh, s->pktout);
9827 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9830 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9831 crWaitUntilV(pktin);
9832 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9833 logevent("GSSAPI authentication - bad server response");
9834 s->gss_stat = SSH_GSS_FAILURE;
9837 ssh_pkt_getstring(pktin, &data, &len);
9838 s->gss_rcvtok.value = data;
9839 s->gss_rcvtok.length = len;
9841 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9843 if (s->gss_stat != SSH_GSS_OK) {
9844 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9845 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9848 logevent("GSSAPI authentication loop finished OK");
9850 /* Now send the MIC */
9852 s->pktout = ssh2_pkt_init(0);
9853 micoffset = s->pktout->length;
9854 ssh_pkt_addstring_start(s->pktout);
9855 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9856 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9857 ssh_pkt_addstring(s->pktout, ssh->username);
9858 ssh_pkt_addstring(s->pktout, "ssh-connection");
9859 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9861 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9862 s->gss_buf.length = s->pktout->length - micoffset;
9864 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9865 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9866 ssh_pkt_addstring_start(s->pktout);
9867 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9868 ssh2_pkt_send(ssh, s->pktout);
9869 s->gsslib->free_mic(s->gsslib, &mic);
9873 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9874 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9877 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9880 * Keyboard-interactive authentication.
9883 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9885 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9887 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9888 ssh2_pkt_addstring(s->pktout, ssh->username);
9889 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9890 /* service requested */
9891 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9893 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9894 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9895 ssh2_pkt_send(ssh, s->pktout);
9897 logevent("Attempting keyboard-interactive authentication");
9899 crWaitUntilV(pktin);
9900 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9901 /* Server is not willing to do keyboard-interactive
9902 * at all (or, bizarrely but legally, accepts the
9903 * user without actually issuing any prompts).
9904 * Give up on it entirely. */
9906 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9907 s->kbd_inter_refused = TRUE; /* don't try it again */
9912 * Loop while the server continues to send INFO_REQUESTs.
9914 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9916 char *name, *inst, *lang;
9917 int name_len, inst_len, lang_len;
9921 * We've got a fresh USERAUTH_INFO_REQUEST.
9922 * Get the preamble and start building a prompt.
9924 ssh_pkt_getstring(pktin, &name, &name_len);
9925 ssh_pkt_getstring(pktin, &inst, &inst_len);
9926 ssh_pkt_getstring(pktin, &lang, &lang_len);
9927 s->cur_prompt = new_prompts(ssh->frontend);
9928 s->cur_prompt->to_server = TRUE;
9931 * Get any prompt(s) from the packet.
9933 s->num_prompts = ssh_pkt_getuint32(pktin);
9934 for (i = 0; i < s->num_prompts; i++) {
9938 static char noprompt[] =
9939 "<server failed to send prompt>: ";
9941 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9942 echo = ssh2_pkt_getbool(pktin);
9945 prompt_len = lenof(noprompt)-1;
9947 add_prompt(s->cur_prompt,
9948 dupprintf("%.*s", prompt_len, prompt),
9953 /* FIXME: better prefix to distinguish from
9955 s->cur_prompt->name =
9956 dupprintf("SSH server: %.*s", name_len, name);
9957 s->cur_prompt->name_reqd = TRUE;
9959 s->cur_prompt->name =
9960 dupstr("SSH server authentication");
9961 s->cur_prompt->name_reqd = FALSE;
9963 /* We add a prefix to try to make it clear that a prompt
9964 * has come from the server.
9965 * FIXME: ugly to print "Using..." in prompt _every_
9966 * time round. Can this be done more subtly? */
9967 /* Special case: for reasons best known to themselves,
9968 * some servers send k-i requests with no prompts and
9969 * nothing to display. Keep quiet in this case. */
9970 if (s->num_prompts || name_len || inst_len) {
9971 s->cur_prompt->instruction =
9972 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9973 inst_len ? "\n" : "", inst_len, inst);
9974 s->cur_prompt->instr_reqd = TRUE;
9976 s->cur_prompt->instr_reqd = FALSE;
9980 * Display any instructions, and get the user's
9984 int ret; /* not live over crReturn */
9985 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9988 crWaitUntilV(!pktin);
9989 ret = get_userpass_input(s->cur_prompt, in, inlen);
9994 * Failed to get responses. Terminate.
9996 free_prompts(s->cur_prompt);
9997 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9998 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10005 * Send the response(s) to the server.
10007 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10008 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10009 for (i=0; i < s->num_prompts; i++) {
10010 ssh2_pkt_addstring(s->pktout,
10011 s->cur_prompt->prompts[i]->result);
10013 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10016 * Free the prompts structure from this iteration.
10017 * If there's another, a new one will be allocated
10018 * when we return to the top of this while loop.
10020 free_prompts(s->cur_prompt);
10023 * Get the next packet in case it's another
10026 crWaitUntilV(pktin);
10031 * We should have SUCCESS or FAILURE now.
10035 } else if (s->can_passwd) {
10038 * Plain old password authentication.
10040 int ret; /* not live over crReturn */
10041 int changereq_first_time; /* not live over crReturn */
10043 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10045 s->cur_prompt = new_prompts(ssh->frontend);
10046 s->cur_prompt->to_server = TRUE;
10047 s->cur_prompt->name = dupstr("SSH password");
10048 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10053 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10056 crWaitUntilV(!pktin);
10057 ret = get_userpass_input(s->cur_prompt, in, inlen);
10062 * Failed to get responses. Terminate.
10064 free_prompts(s->cur_prompt);
10065 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10066 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10071 * Squirrel away the password. (We may need it later if
10072 * asked to change it.)
10074 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10075 free_prompts(s->cur_prompt);
10078 * Send the password packet.
10080 * We pad out the password packet to 256 bytes to make
10081 * it harder for an attacker to find the length of the
10084 * Anyone using a password longer than 256 bytes
10085 * probably doesn't have much to worry about from
10086 * people who find out how long their password is!
10088 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10089 ssh2_pkt_addstring(s->pktout, ssh->username);
10090 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10091 /* service requested */
10092 ssh2_pkt_addstring(s->pktout, "password");
10093 ssh2_pkt_addbool(s->pktout, FALSE);
10094 ssh2_pkt_addstring(s->pktout, s->password);
10095 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10096 logevent("Sent password");
10097 s->type = AUTH_TYPE_PASSWORD;
10100 * Wait for next packet, in case it's a password change
10103 crWaitUntilV(pktin);
10104 changereq_first_time = TRUE;
10106 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10109 * We're being asked for a new password
10110 * (perhaps not for the first time).
10111 * Loop until the server accepts it.
10114 int got_new = FALSE; /* not live over crReturn */
10115 char *prompt; /* not live over crReturn */
10116 int prompt_len; /* not live over crReturn */
10120 if (changereq_first_time)
10121 msg = "Server requested password change";
10123 msg = "Server rejected new password";
10125 c_write_str(ssh, msg);
10126 c_write_str(ssh, "\r\n");
10129 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10131 s->cur_prompt = new_prompts(ssh->frontend);
10132 s->cur_prompt->to_server = TRUE;
10133 s->cur_prompt->name = dupstr("New SSH password");
10134 s->cur_prompt->instruction =
10135 dupprintf("%.*s", prompt_len, prompt);
10136 s->cur_prompt->instr_reqd = TRUE;
10138 * There's no explicit requirement in the protocol
10139 * for the "old" passwords in the original and
10140 * password-change messages to be the same, and
10141 * apparently some Cisco kit supports password change
10142 * by the user entering a blank password originally
10143 * and the real password subsequently, so,
10144 * reluctantly, we prompt for the old password again.
10146 * (On the other hand, some servers don't even bother
10147 * to check this field.)
10149 add_prompt(s->cur_prompt,
10150 dupstr("Current password (blank for previously entered password): "),
10152 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10154 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10158 * Loop until the user manages to enter the same
10163 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10166 crWaitUntilV(!pktin);
10167 ret = get_userpass_input(s->cur_prompt, in, inlen);
10172 * Failed to get responses. Terminate.
10174 /* burn the evidence */
10175 free_prompts(s->cur_prompt);
10176 smemclr(s->password, strlen(s->password));
10177 sfree(s->password);
10178 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10179 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10185 * If the user specified a new original password
10186 * (IYSWIM), overwrite any previously specified
10188 * (A side effect is that the user doesn't have to
10189 * re-enter it if they louse up the new password.)
10191 if (s->cur_prompt->prompts[0]->result[0]) {
10192 smemclr(s->password, strlen(s->password));
10193 /* burn the evidence */
10194 sfree(s->password);
10196 dupstr(s->cur_prompt->prompts[0]->result);
10200 * Check the two new passwords match.
10202 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10203 s->cur_prompt->prompts[2]->result)
10206 /* They don't. Silly user. */
10207 c_write_str(ssh, "Passwords do not match\r\n");
10212 * Send the new password (along with the old one).
10213 * (see above for padding rationale)
10215 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10216 ssh2_pkt_addstring(s->pktout, ssh->username);
10217 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10218 /* service requested */
10219 ssh2_pkt_addstring(s->pktout, "password");
10220 ssh2_pkt_addbool(s->pktout, TRUE);
10221 ssh2_pkt_addstring(s->pktout, s->password);
10222 ssh2_pkt_addstring(s->pktout,
10223 s->cur_prompt->prompts[1]->result);
10224 free_prompts(s->cur_prompt);
10225 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10226 logevent("Sent new password");
10229 * Now see what the server has to say about it.
10230 * (If it's CHANGEREQ again, it's not happy with the
10233 crWaitUntilV(pktin);
10234 changereq_first_time = FALSE;
10239 * We need to reexamine the current pktin at the top
10240 * of the loop. Either:
10241 * - we weren't asked to change password at all, in
10242 * which case it's a SUCCESS or FAILURE with the
10244 * - we sent a new password, and the server was
10245 * either OK with it (SUCCESS or FAILURE w/partial
10246 * success) or unhappy with the _old_ password
10247 * (FAILURE w/o partial success)
10248 * In any of these cases, we go back to the top of
10249 * the loop and start again.
10254 * We don't need the old password any more, in any
10255 * case. Burn the evidence.
10257 smemclr(s->password, strlen(s->password));
10258 sfree(s->password);
10261 char *str = dupprintf("No supported authentication methods available"
10262 " (server sent: %.*s)",
10265 ssh_disconnect(ssh, str,
10266 "No supported authentication methods available",
10267 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10277 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10279 /* Clear up various bits and pieces from authentication. */
10280 if (s->publickey_blob) {
10281 sfree(s->publickey_algorithm);
10282 sfree(s->publickey_blob);
10283 sfree(s->publickey_comment);
10285 if (s->agent_response)
10286 sfree(s->agent_response);
10288 if (s->userauth_success && !ssh->bare_connection) {
10290 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10291 * packets since. Signal the transport layer to consider enacting
10292 * delayed compression.
10294 * (Relying on we_are_in is not sufficient, as
10295 * draft-miller-secsh-compression-delayed is quite clear that it
10296 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10297 * become set for other reasons.)
10299 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10302 ssh->channels = newtree234(ssh_channelcmp);
10305 * Set up handlers for some connection protocol messages, so we
10306 * don't have to handle them repeatedly in this coroutine.
10308 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10309 ssh2_msg_channel_window_adjust;
10310 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10311 ssh2_msg_global_request;
10314 * Create the main session channel.
10316 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10317 ssh->mainchan = NULL;
10319 ssh->mainchan = snew(struct ssh_channel);
10320 ssh->mainchan->ssh = ssh;
10321 ssh2_channel_init(ssh->mainchan);
10323 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10325 * Just start a direct-tcpip channel and use it as the main
10328 ssh_send_port_open(ssh->mainchan,
10329 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10330 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10332 ssh->ncmode = TRUE;
10334 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10335 logevent("Opening session as main channel");
10336 ssh2_pkt_send(ssh, s->pktout);
10337 ssh->ncmode = FALSE;
10339 crWaitUntilV(pktin);
10340 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10341 bombout(("Server refused to open channel"));
10343 /* FIXME: error data comes back in FAILURE packet */
10345 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10346 bombout(("Server's channel confirmation cited wrong channel"));
10349 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10350 ssh->mainchan->halfopen = FALSE;
10351 ssh->mainchan->type = CHAN_MAINSESSION;
10352 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10353 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10354 add234(ssh->channels, ssh->mainchan);
10355 update_specials_menu(ssh->frontend);
10356 logevent("Opened main channel");
10360 * Now we have a channel, make dispatch table entries for
10361 * general channel-based messages.
10363 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10364 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10365 ssh2_msg_channel_data;
10366 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10367 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10368 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10369 ssh2_msg_channel_open_confirmation;
10370 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10371 ssh2_msg_channel_open_failure;
10372 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10373 ssh2_msg_channel_request;
10374 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10375 ssh2_msg_channel_open;
10376 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10377 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10380 * Now the connection protocol is properly up and running, with
10381 * all those dispatch table entries, so it's safe to let
10382 * downstreams start trying to open extra channels through us.
10384 if (ssh->connshare)
10385 share_activate(ssh->connshare, ssh->v_s);
10387 if (ssh->mainchan && ssh_is_simple(ssh)) {
10389 * This message indicates to the server that we promise
10390 * not to try to run any other channel in parallel with
10391 * this one, so it's safe for it to advertise a very large
10392 * window and leave the flow control to TCP.
10394 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10395 "simple@putty.projects.tartarus.org",
10397 ssh2_pkt_send(ssh, s->pktout);
10401 * Enable port forwardings.
10403 ssh_setup_portfwd(ssh, ssh->conf);
10405 if (ssh->mainchan && !ssh->ncmode) {
10407 * Send the CHANNEL_REQUESTS for the main session channel.
10408 * Each one is handled by its own little asynchronous
10412 /* Potentially enable X11 forwarding. */
10413 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10415 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10417 if (!ssh->x11disp) {
10418 /* FIXME: return an error message from x11_setup_display */
10419 logevent("X11 forwarding not enabled: unable to"
10420 " initialise X display");
10422 ssh->x11auth = x11_invent_fake_auth
10423 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10424 ssh->x11auth->disp = ssh->x11disp;
10426 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10430 /* Potentially enable agent forwarding. */
10431 if (ssh_agent_forwarding_permitted(ssh))
10432 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10434 /* Now allocate a pty for the session. */
10435 if (!conf_get_int(ssh->conf, CONF_nopty))
10436 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10438 /* Send environment variables. */
10439 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10442 * Start a shell or a remote command. We may have to attempt
10443 * this twice if the config data has provided a second choice
10450 if (ssh->fallback_cmd) {
10451 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10452 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10454 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10455 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10459 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10460 ssh2_response_authconn, NULL);
10461 ssh2_pkt_addstring(s->pktout, cmd);
10463 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10464 ssh2_response_authconn, NULL);
10465 ssh2_pkt_addstring(s->pktout, cmd);
10467 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10468 ssh2_response_authconn, NULL);
10470 ssh2_pkt_send(ssh, s->pktout);
10472 crWaitUntilV(pktin);
10474 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10475 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10476 bombout(("Unexpected response to shell/command request:"
10477 " packet type %d", pktin->type));
10481 * We failed to start the command. If this is the
10482 * fallback command, we really are finished; if it's
10483 * not, and if the fallback command exists, try falling
10484 * back to it before complaining.
10486 if (!ssh->fallback_cmd &&
10487 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10488 logevent("Primary command failed; attempting fallback");
10489 ssh->fallback_cmd = TRUE;
10492 bombout(("Server refused to start a shell/command"));
10495 logevent("Started a shell/command");
10500 ssh->editing = ssh->echoing = TRUE;
10503 ssh->state = SSH_STATE_SESSION;
10504 if (ssh->size_needed)
10505 ssh_size(ssh, ssh->term_width, ssh->term_height);
10506 if (ssh->eof_needed)
10507 ssh_special(ssh, TS_EOF);
10513 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10518 s->try_send = FALSE;
10522 * _All_ the connection-layer packets we expect to
10523 * receive are now handled by the dispatch table.
10524 * Anything that reaches here must be bogus.
10527 bombout(("Strange packet received: type %d", pktin->type));
10529 } else if (ssh->mainchan) {
10531 * We have spare data. Add it to the channel buffer.
10533 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10534 s->try_send = TRUE;
10538 struct ssh_channel *c;
10540 * Try to send data on all channels if we can.
10542 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10543 ssh2_try_send_and_unthrottle(ssh, c);
10551 * Handlers for SSH-2 messages that might arrive at any moment.
10553 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10555 /* log reason code in disconnect message */
10557 int reason, msglen;
10559 reason = ssh_pkt_getuint32(pktin);
10560 ssh_pkt_getstring(pktin, &msg, &msglen);
10562 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10563 buf = dupprintf("Received disconnect message (%s)",
10564 ssh2_disconnect_reasons[reason]);
10566 buf = dupprintf("Received disconnect message (unknown"
10567 " type %d)", reason);
10571 buf = dupprintf("Disconnection message text: %.*s",
10574 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10576 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10577 ssh2_disconnect_reasons[reason] : "unknown",
10582 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10584 /* log the debug message */
10588 /* XXX maybe we should actually take notice of the return value */
10589 ssh2_pkt_getbool(pktin);
10590 ssh_pkt_getstring(pktin, &msg, &msglen);
10592 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10595 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10597 do_ssh2_transport(ssh, NULL, 0, pktin);
10601 * Called if we receive a packet that isn't allowed by the protocol.
10602 * This only applies to packets whose meaning PuTTY understands.
10603 * Entirely unknown packets are handled below.
10605 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10607 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10608 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10610 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10614 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10616 struct Packet *pktout;
10617 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10618 ssh2_pkt_adduint32(pktout, pktin->sequence);
10620 * UNIMPLEMENTED messages MUST appear in the same order as the
10621 * messages they respond to. Hence, never queue them.
10623 ssh2_pkt_send_noqueue(ssh, pktout);
10627 * Handle the top-level SSH-2 protocol.
10629 static void ssh2_protocol_setup(Ssh ssh)
10634 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10636 for (i = 0; i < 256; i++)
10637 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10640 * Initially, we only accept transport messages (and a few generic
10641 * ones). do_ssh2_authconn will add more when it starts.
10642 * Messages that are understood but not currently acceptable go to
10643 * ssh2_msg_unexpected.
10645 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10646 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10647 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10648 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10649 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10650 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10651 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10652 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10653 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10654 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10655 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10656 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10657 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10658 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10659 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10660 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10661 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10662 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10663 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10664 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10665 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10666 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10667 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10668 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10669 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10670 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10671 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10672 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10673 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10674 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10675 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10676 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10677 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10680 * These messages have a special handler from the start.
10682 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10683 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10684 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10687 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10692 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10694 for (i = 0; i < 256; i++)
10695 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10698 * Initially, we set all ssh-connection messages to 'unexpected';
10699 * do_ssh2_authconn will fill things in properly. We also handle a
10700 * couple of messages from the transport protocol which aren't
10701 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10704 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10705 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10706 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10707 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10708 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10709 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10710 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10711 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10712 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10713 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10714 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10715 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10716 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10717 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10719 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10722 * These messages have a special handler from the start.
10724 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10725 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10726 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10729 static void ssh2_timer(void *ctx, unsigned long now)
10731 Ssh ssh = (Ssh)ctx;
10733 if (ssh->state == SSH_STATE_CLOSED)
10736 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10737 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10738 now == ssh->next_rekey) {
10739 do_ssh2_transport(ssh, "timeout", -1, NULL);
10743 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10744 struct Packet *pktin)
10746 unsigned char *in = (unsigned char *)vin;
10747 if (ssh->state == SSH_STATE_CLOSED)
10751 ssh->incoming_data_size += pktin->encrypted_len;
10752 if (!ssh->kex_in_progress &&
10753 ssh->max_data_size != 0 &&
10754 ssh->incoming_data_size > ssh->max_data_size)
10755 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10759 ssh->packet_dispatch[pktin->type](ssh, pktin);
10760 else if (!ssh->protocol_initial_phase_done)
10761 do_ssh2_transport(ssh, in, inlen, pktin);
10763 do_ssh2_authconn(ssh, in, inlen, pktin);
10766 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10767 struct Packet *pktin)
10769 unsigned char *in = (unsigned char *)vin;
10770 if (ssh->state == SSH_STATE_CLOSED)
10774 ssh->packet_dispatch[pktin->type](ssh, pktin);
10776 do_ssh2_authconn(ssh, in, inlen, pktin);
10779 static void ssh_cache_conf_values(Ssh ssh)
10781 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10785 * Called to set up the connection.
10787 * Returns an error message, or NULL on success.
10789 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10790 Conf *conf, char *host, int port, char **realhost,
10791 int nodelay, int keepalive)
10796 ssh = snew(struct ssh_tag);
10797 ssh->conf = conf_copy(conf);
10798 ssh_cache_conf_values(ssh);
10799 ssh->version = 0; /* when not ready yet */
10801 ssh->cipher = NULL;
10802 ssh->v1_cipher_ctx = NULL;
10803 ssh->crcda_ctx = NULL;
10804 ssh->cscipher = NULL;
10805 ssh->cs_cipher_ctx = NULL;
10806 ssh->sccipher = NULL;
10807 ssh->sc_cipher_ctx = NULL;
10809 ssh->cs_mac_ctx = NULL;
10811 ssh->sc_mac_ctx = NULL;
10812 ssh->cscomp = NULL;
10813 ssh->cs_comp_ctx = NULL;
10814 ssh->sccomp = NULL;
10815 ssh->sc_comp_ctx = NULL;
10817 ssh->kex_ctx = NULL;
10818 ssh->hostkey = NULL;
10819 ssh->hostkey_str = NULL;
10820 ssh->exitcode = -1;
10821 ssh->close_expected = FALSE;
10822 ssh->clean_exit = FALSE;
10823 ssh->state = SSH_STATE_PREPACKET;
10824 ssh->size_needed = FALSE;
10825 ssh->eof_needed = FALSE;
10827 ssh->logctx = NULL;
10828 ssh->deferred_send_data = NULL;
10829 ssh->deferred_len = 0;
10830 ssh->deferred_size = 0;
10831 ssh->fallback_cmd = 0;
10832 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10833 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10834 ssh->x11disp = NULL;
10835 ssh->x11auth = NULL;
10836 ssh->x11authtree = newtree234(x11_authcmp);
10837 ssh->v1_compressing = FALSE;
10838 ssh->v2_outgoing_sequence = 0;
10839 ssh->ssh1_rdpkt_crstate = 0;
10840 ssh->ssh2_rdpkt_crstate = 0;
10841 ssh->ssh2_bare_rdpkt_crstate = 0;
10842 ssh->ssh_gotdata_crstate = 0;
10843 ssh->do_ssh1_connection_crstate = 0;
10844 ssh->do_ssh_init_state = NULL;
10845 ssh->do_ssh_connection_init_state = NULL;
10846 ssh->do_ssh1_login_state = NULL;
10847 ssh->do_ssh2_transport_state = NULL;
10848 ssh->do_ssh2_authconn_state = NULL;
10851 ssh->mainchan = NULL;
10852 ssh->throttled_all = 0;
10853 ssh->v1_stdout_throttling = 0;
10855 ssh->queuelen = ssh->queuesize = 0;
10856 ssh->queueing = FALSE;
10857 ssh->qhead = ssh->qtail = NULL;
10858 ssh->deferred_rekey_reason = NULL;
10859 bufchain_init(&ssh->queued_incoming_data);
10860 ssh->frozen = FALSE;
10861 ssh->username = NULL;
10862 ssh->sent_console_eof = FALSE;
10863 ssh->got_pty = FALSE;
10864 ssh->bare_connection = FALSE;
10865 ssh->X11_fwd_enabled = FALSE;
10866 ssh->connshare = NULL;
10867 ssh->attempting_connshare = FALSE;
10869 *backend_handle = ssh;
10872 if (crypto_startup() == 0)
10873 return "Microsoft high encryption pack not installed!";
10876 ssh->frontend = frontend_handle;
10877 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10878 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10880 ssh->channels = NULL;
10881 ssh->rportfwds = NULL;
10882 ssh->portfwds = NULL;
10887 ssh->conn_throttle_count = 0;
10888 ssh->overall_bufsize = 0;
10889 ssh->fallback_cmd = 0;
10891 ssh->protocol = NULL;
10893 ssh->protocol_initial_phase_done = FALSE;
10895 ssh->pinger = NULL;
10897 ssh->incoming_data_size = ssh->outgoing_data_size =
10898 ssh->deferred_data_size = 0L;
10899 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10900 CONF_ssh_rekey_data));
10901 ssh->kex_in_progress = FALSE;
10904 ssh->gsslibs = NULL;
10907 random_ref(); /* do this now - may be needed by sharing setup code */
10909 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10918 static void ssh_free(void *handle)
10920 Ssh ssh = (Ssh) handle;
10921 struct ssh_channel *c;
10922 struct ssh_rportfwd *pf;
10923 struct X11FakeAuth *auth;
10925 if (ssh->v1_cipher_ctx)
10926 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10927 if (ssh->cs_cipher_ctx)
10928 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10929 if (ssh->sc_cipher_ctx)
10930 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10931 if (ssh->cs_mac_ctx)
10932 ssh->csmac->free_context(ssh->cs_mac_ctx);
10933 if (ssh->sc_mac_ctx)
10934 ssh->scmac->free_context(ssh->sc_mac_ctx);
10935 if (ssh->cs_comp_ctx) {
10937 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10939 zlib_compress_cleanup(ssh->cs_comp_ctx);
10941 if (ssh->sc_comp_ctx) {
10943 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10945 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10948 dh_cleanup(ssh->kex_ctx);
10949 sfree(ssh->savedhost);
10951 while (ssh->queuelen-- > 0)
10952 ssh_free_packet(ssh->queue[ssh->queuelen]);
10955 while (ssh->qhead) {
10956 struct queued_handler *qh = ssh->qhead;
10957 ssh->qhead = qh->next;
10960 ssh->qhead = ssh->qtail = NULL;
10962 if (ssh->channels) {
10963 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10966 if (c->u.x11.xconn != NULL)
10967 x11_close(c->u.x11.xconn);
10969 case CHAN_SOCKDATA:
10970 case CHAN_SOCKDATA_DORMANT:
10971 if (c->u.pfd.pf != NULL)
10972 pfd_close(c->u.pfd.pf);
10975 if (ssh->version == 2) {
10976 struct outstanding_channel_request *ocr, *nocr;
10977 ocr = c->v.v2.chanreq_head;
10979 ocr->handler(c, NULL, ocr->ctx);
10984 bufchain_clear(&c->v.v2.outbuffer);
10988 freetree234(ssh->channels);
10989 ssh->channels = NULL;
10992 if (ssh->connshare)
10993 sharestate_free(ssh->connshare);
10995 if (ssh->rportfwds) {
10996 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10998 freetree234(ssh->rportfwds);
10999 ssh->rportfwds = NULL;
11001 sfree(ssh->deferred_send_data);
11003 x11_free_display(ssh->x11disp);
11004 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11005 x11_free_fake_auth(auth);
11006 freetree234(ssh->x11authtree);
11007 sfree(ssh->do_ssh_init_state);
11008 sfree(ssh->do_ssh1_login_state);
11009 sfree(ssh->do_ssh2_transport_state);
11010 sfree(ssh->do_ssh2_authconn_state);
11013 sfree(ssh->fullhostname);
11014 sfree(ssh->hostkey_str);
11015 if (ssh->crcda_ctx) {
11016 crcda_free_context(ssh->crcda_ctx);
11017 ssh->crcda_ctx = NULL;
11020 ssh_do_close(ssh, TRUE);
11021 expire_timer_context(ssh);
11023 pinger_free(ssh->pinger);
11024 bufchain_clear(&ssh->queued_incoming_data);
11025 sfree(ssh->username);
11026 conf_free(ssh->conf);
11029 ssh_gss_cleanup(ssh->gsslibs);
11037 * Reconfigure the SSH backend.
11039 static void ssh_reconfig(void *handle, Conf *conf)
11041 Ssh ssh = (Ssh) handle;
11042 char *rekeying = NULL, rekey_mandatory = FALSE;
11043 unsigned long old_max_data_size;
11046 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11048 ssh_setup_portfwd(ssh, conf);
11050 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11051 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11053 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11054 unsigned long now = GETTICKCOUNT();
11056 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11057 rekeying = "timeout shortened";
11059 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11063 old_max_data_size = ssh->max_data_size;
11064 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11065 CONF_ssh_rekey_data));
11066 if (old_max_data_size != ssh->max_data_size &&
11067 ssh->max_data_size != 0) {
11068 if (ssh->outgoing_data_size > ssh->max_data_size ||
11069 ssh->incoming_data_size > ssh->max_data_size)
11070 rekeying = "data limit lowered";
11073 if (conf_get_int(ssh->conf, CONF_compression) !=
11074 conf_get_int(conf, CONF_compression)) {
11075 rekeying = "compression setting changed";
11076 rekey_mandatory = TRUE;
11079 for (i = 0; i < CIPHER_MAX; i++)
11080 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11081 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11082 rekeying = "cipher settings changed";
11083 rekey_mandatory = TRUE;
11085 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11086 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11087 rekeying = "cipher settings changed";
11088 rekey_mandatory = TRUE;
11091 conf_free(ssh->conf);
11092 ssh->conf = conf_copy(conf);
11093 ssh_cache_conf_values(ssh);
11095 if (!ssh->bare_connection && rekeying) {
11096 if (!ssh->kex_in_progress) {
11097 do_ssh2_transport(ssh, rekeying, -1, NULL);
11098 } else if (rekey_mandatory) {
11099 ssh->deferred_rekey_reason = rekeying;
11105 * Called to send data down the SSH connection.
11107 static int ssh_send(void *handle, char *buf, int len)
11109 Ssh ssh = (Ssh) handle;
11111 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11114 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
11116 return ssh_sendbuffer(ssh);
11120 * Called to query the current amount of buffered stdin data.
11122 static int ssh_sendbuffer(void *handle)
11124 Ssh ssh = (Ssh) handle;
11125 int override_value;
11127 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11131 * If the SSH socket itself has backed up, add the total backup
11132 * size on that to any individual buffer on the stdin channel.
11134 override_value = 0;
11135 if (ssh->throttled_all)
11136 override_value = ssh->overall_bufsize;
11138 if (ssh->version == 1) {
11139 return override_value;
11140 } else if (ssh->version == 2) {
11141 if (!ssh->mainchan)
11142 return override_value;
11144 return (override_value +
11145 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11152 * Called to set the size of the window from SSH's POV.
11154 static void ssh_size(void *handle, int width, int height)
11156 Ssh ssh = (Ssh) handle;
11157 struct Packet *pktout;
11159 ssh->term_width = width;
11160 ssh->term_height = height;
11162 switch (ssh->state) {
11163 case SSH_STATE_BEFORE_SIZE:
11164 case SSH_STATE_PREPACKET:
11165 case SSH_STATE_CLOSED:
11166 break; /* do nothing */
11167 case SSH_STATE_INTERMED:
11168 ssh->size_needed = TRUE; /* buffer for later */
11170 case SSH_STATE_SESSION:
11171 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11172 if (ssh->version == 1) {
11173 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11174 PKT_INT, ssh->term_height,
11175 PKT_INT, ssh->term_width,
11176 PKT_INT, 0, PKT_INT, 0, PKT_END);
11177 } else if (ssh->mainchan) {
11178 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11180 ssh2_pkt_adduint32(pktout, ssh->term_width);
11181 ssh2_pkt_adduint32(pktout, ssh->term_height);
11182 ssh2_pkt_adduint32(pktout, 0);
11183 ssh2_pkt_adduint32(pktout, 0);
11184 ssh2_pkt_send(ssh, pktout);
11192 * Return a list of the special codes that make sense in this
11195 static const struct telnet_special *ssh_get_specials(void *handle)
11197 static const struct telnet_special ssh1_ignore_special[] = {
11198 {"IGNORE message", TS_NOP}
11200 static const struct telnet_special ssh2_ignore_special[] = {
11201 {"IGNORE message", TS_NOP},
11203 static const struct telnet_special ssh2_rekey_special[] = {
11204 {"Repeat key exchange", TS_REKEY},
11206 static const struct telnet_special ssh2_session_specials[] = {
11209 /* These are the signal names defined by RFC 4254.
11210 * They include all the ISO C signals, but are a subset of the POSIX
11211 * required signals. */
11212 {"SIGINT (Interrupt)", TS_SIGINT},
11213 {"SIGTERM (Terminate)", TS_SIGTERM},
11214 {"SIGKILL (Kill)", TS_SIGKILL},
11215 {"SIGQUIT (Quit)", TS_SIGQUIT},
11216 {"SIGHUP (Hangup)", TS_SIGHUP},
11217 {"More signals", TS_SUBMENU},
11218 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11219 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11220 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11221 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11222 {NULL, TS_EXITMENU}
11224 static const struct telnet_special specials_end[] = {
11225 {NULL, TS_EXITMENU}
11227 /* XXX review this length for any changes: */
11228 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11229 lenof(ssh2_rekey_special) +
11230 lenof(ssh2_session_specials) +
11231 lenof(specials_end)];
11232 Ssh ssh = (Ssh) handle;
11234 #define ADD_SPECIALS(name) \
11236 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11237 memcpy(&ssh_specials[i], name, sizeof name); \
11238 i += lenof(name); \
11241 if (ssh->version == 1) {
11242 /* Don't bother offering IGNORE if we've decided the remote
11243 * won't cope with it, since we wouldn't bother sending it if
11245 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11246 ADD_SPECIALS(ssh1_ignore_special);
11247 } else if (ssh->version == 2) {
11248 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11249 ADD_SPECIALS(ssh2_ignore_special);
11250 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11251 ADD_SPECIALS(ssh2_rekey_special);
11253 ADD_SPECIALS(ssh2_session_specials);
11254 } /* else we're not ready yet */
11257 ADD_SPECIALS(specials_end);
11258 return ssh_specials;
11262 #undef ADD_SPECIALS
11266 * Send special codes. TS_EOF is useful for `plink', so you
11267 * can send an EOF and collect resulting output (e.g. `plink
11270 static void ssh_special(void *handle, Telnet_Special code)
11272 Ssh ssh = (Ssh) handle;
11273 struct Packet *pktout;
11275 if (code == TS_EOF) {
11276 if (ssh->state != SSH_STATE_SESSION) {
11278 * Buffer the EOF in case we are pre-SESSION, so we can
11279 * send it as soon as we reach SESSION.
11281 if (code == TS_EOF)
11282 ssh->eof_needed = TRUE;
11285 if (ssh->version == 1) {
11286 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11287 } else if (ssh->mainchan) {
11288 sshfwd_write_eof(ssh->mainchan);
11289 ssh->send_ok = 0; /* now stop trying to read from stdin */
11291 logevent("Sent EOF message");
11292 } else if (code == TS_PING || code == TS_NOP) {
11293 if (ssh->state == SSH_STATE_CLOSED
11294 || ssh->state == SSH_STATE_PREPACKET) return;
11295 if (ssh->version == 1) {
11296 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11297 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11299 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11300 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11301 ssh2_pkt_addstring_start(pktout);
11302 ssh2_pkt_send_noqueue(ssh, pktout);
11305 } else if (code == TS_REKEY) {
11306 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11307 ssh->version == 2) {
11308 do_ssh2_transport(ssh, "at user request", -1, NULL);
11310 } else if (code == TS_BRK) {
11311 if (ssh->state == SSH_STATE_CLOSED
11312 || ssh->state == SSH_STATE_PREPACKET) return;
11313 if (ssh->version == 1) {
11314 logevent("Unable to send BREAK signal in SSH-1");
11315 } else if (ssh->mainchan) {
11316 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11317 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11318 ssh2_pkt_send(ssh, pktout);
11321 /* Is is a POSIX signal? */
11322 char *signame = NULL;
11323 if (code == TS_SIGABRT) signame = "ABRT";
11324 if (code == TS_SIGALRM) signame = "ALRM";
11325 if (code == TS_SIGFPE) signame = "FPE";
11326 if (code == TS_SIGHUP) signame = "HUP";
11327 if (code == TS_SIGILL) signame = "ILL";
11328 if (code == TS_SIGINT) signame = "INT";
11329 if (code == TS_SIGKILL) signame = "KILL";
11330 if (code == TS_SIGPIPE) signame = "PIPE";
11331 if (code == TS_SIGQUIT) signame = "QUIT";
11332 if (code == TS_SIGSEGV) signame = "SEGV";
11333 if (code == TS_SIGTERM) signame = "TERM";
11334 if (code == TS_SIGUSR1) signame = "USR1";
11335 if (code == TS_SIGUSR2) signame = "USR2";
11336 /* The SSH-2 protocol does in principle support arbitrary named
11337 * signals, including signame@domain, but we don't support those. */
11339 /* It's a signal. */
11340 if (ssh->version == 2 && ssh->mainchan) {
11341 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11342 ssh2_pkt_addstring(pktout, signame);
11343 ssh2_pkt_send(ssh, pktout);
11344 logeventf(ssh, "Sent signal SIG%s", signame);
11347 /* Never heard of it. Do nothing */
11352 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11354 Ssh ssh = (Ssh) handle;
11355 struct ssh_channel *c;
11356 c = snew(struct ssh_channel);
11359 ssh2_channel_init(c);
11360 c->halfopen = TRUE;
11361 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11363 add234(ssh->channels, c);
11367 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11369 struct ssh_channel *c;
11370 c = snew(struct ssh_channel);
11373 ssh2_channel_init(c);
11374 c->type = CHAN_SHARING;
11375 c->u.sharing.ctx = sharing_ctx;
11376 add234(ssh->channels, c);
11380 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11382 struct ssh_channel *c;
11384 c = find234(ssh->channels, &localid, ssh_channelfind);
11386 ssh_channel_destroy(c);
11389 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11390 const void *data, int datalen,
11391 const char *additional_log_text)
11393 struct Packet *pkt;
11395 pkt = ssh2_pkt_init(type);
11396 pkt->downstream_id = id;
11397 pkt->additional_log_text = additional_log_text;
11398 ssh2_pkt_adddata(pkt, data, datalen);
11399 ssh2_pkt_send(ssh, pkt);
11403 * This is called when stdout/stderr (the entity to which
11404 * from_backend sends data) manages to clear some backlog.
11406 static void ssh_unthrottle(void *handle, int bufsize)
11408 Ssh ssh = (Ssh) handle;
11411 if (ssh->version == 1) {
11412 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11413 ssh->v1_stdout_throttling = 0;
11414 ssh_throttle_conn(ssh, -1);
11417 if (ssh->mainchan) {
11418 ssh2_set_window(ssh->mainchan,
11419 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11420 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11421 if (ssh_is_simple(ssh))
11424 buflimit = ssh->mainchan->v.v2.locmaxwin;
11425 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11426 ssh->mainchan->throttling_conn = 0;
11427 ssh_throttle_conn(ssh, -1);
11433 * Now process any SSH connection data that was stashed in our
11434 * queue while we were frozen.
11436 ssh_process_queued_incoming_data(ssh);
11439 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11441 struct ssh_channel *c = (struct ssh_channel *)channel;
11443 struct Packet *pktout;
11445 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11447 if (ssh->version == 1) {
11448 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11449 PKT_INT, c->localid,
11452 /* PKT_STR, <org:orgport>, */
11455 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11457 char *trimmed_host = host_strduptrim(hostname);
11458 ssh2_pkt_addstring(pktout, trimmed_host);
11459 sfree(trimmed_host);
11461 ssh2_pkt_adduint32(pktout, port);
11463 * We make up values for the originator data; partly it's
11464 * too much hassle to keep track, and partly I'm not
11465 * convinced the server should be told details like that
11466 * about my local network configuration.
11467 * The "originator IP address" is syntactically a numeric
11468 * IP address, and some servers (e.g., Tectia) get upset
11469 * if it doesn't match this syntax.
11471 ssh2_pkt_addstring(pktout, "0.0.0.0");
11472 ssh2_pkt_adduint32(pktout, 0);
11473 ssh2_pkt_send(ssh, pktout);
11477 static int ssh_connected(void *handle)
11479 Ssh ssh = (Ssh) handle;
11480 return ssh->s != NULL;
11483 static int ssh_sendok(void *handle)
11485 Ssh ssh = (Ssh) handle;
11486 return ssh->send_ok;
11489 static int ssh_ldisc(void *handle, int option)
11491 Ssh ssh = (Ssh) handle;
11492 if (option == LD_ECHO)
11493 return ssh->echoing;
11494 if (option == LD_EDIT)
11495 return ssh->editing;
11499 static void ssh_provide_ldisc(void *handle, void *ldisc)
11501 Ssh ssh = (Ssh) handle;
11502 ssh->ldisc = ldisc;
11505 static void ssh_provide_logctx(void *handle, void *logctx)
11507 Ssh ssh = (Ssh) handle;
11508 ssh->logctx = logctx;
11511 static int ssh_return_exitcode(void *handle)
11513 Ssh ssh = (Ssh) handle;
11514 if (ssh->s != NULL)
11517 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11521 * cfg_info for SSH is the protocol running in this session.
11522 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11523 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11525 static int ssh_cfg_info(void *handle)
11527 Ssh ssh = (Ssh) handle;
11528 if (ssh->version == 0)
11529 return 0; /* don't know yet */
11530 else if (ssh->bare_connection)
11533 return ssh->version;
11537 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11538 * that fails. This variable is the means by which scp.c can reach
11539 * into the SSH code and find out which one it got.
11541 extern int ssh_fallback_cmd(void *handle)
11543 Ssh ssh = (Ssh) handle;
11544 return ssh->fallback_cmd;
11547 Backend ssh_backend = {
11557 ssh_return_exitcode,
11561 ssh_provide_logctx,