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 (!ssh->kex->pdata) {
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(s->hostkeydata, s->hostkeylen);
6809 s->f = ssh2_pkt_getmp(pktin);
6811 bombout(("unable to parse key exchange reply packet"));
6814 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6817 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6819 bombout(("key exchange reply failed validation: %s", err));
6823 s->K = dh_find_K(ssh->kex_ctx, s->f);
6825 /* We assume everything from now on will be quick, and it might
6826 * involve user interaction. */
6827 set_busy_status(ssh->frontend, BUSY_NOT);
6829 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6830 if (!ssh->kex->pdata) {
6831 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6832 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6833 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6834 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6835 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6836 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6837 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6839 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6840 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6842 dh_cleanup(ssh->kex_ctx);
6844 if (!ssh->kex->pdata) {
6848 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6850 logeventf(ssh, "Doing ECDH key exchange with hash %s",
6851 ssh->kex->hash->text_name);
6852 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6854 s->eckey = ssh_ecdhkex_newkey(ssh->kex->name);
6856 bombout(("Unable to generate key for ECDH"));
6862 int publicPointLength;
6863 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6865 ssh_ecdhkex_freekey(s->eckey);
6866 bombout(("Unable to encode public key for ECDH"));
6869 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6870 ssh2_pkt_addstring_start(s->pktout);
6871 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6875 ssh2_pkt_send_noqueue(ssh, s->pktout);
6877 crWaitUntilV(pktin);
6878 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6879 ssh_ecdhkex_freekey(s->eckey);
6880 bombout(("expected ECDH reply packet from server"));
6884 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6885 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6886 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6890 int publicPointLength;
6891 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6893 ssh_ecdhkex_freekey(s->eckey);
6894 bombout(("Unable to encode public key for ECDH hash"));
6897 hash_string(ssh->kex->hash, ssh->exhash,
6898 publicPoint, publicPointLength);
6905 ssh_pkt_getstring(pktin, &keydata, &keylen);
6906 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
6907 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
6909 ssh_ecdhkex_freekey(s->eckey);
6910 bombout(("point received in ECDH was not valid"));
6915 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6917 ssh_ecdhkex_freekey(s->eckey);
6919 logeventf(ssh, "Doing RSA key exchange with hash %s",
6920 ssh->kex->hash->text_name);
6921 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6923 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6926 crWaitUntilV(pktin);
6927 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6928 bombout(("expected RSA public key packet from server"));
6932 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6933 hash_string(ssh->kex->hash, ssh->exhash,
6934 s->hostkeydata, s->hostkeylen);
6935 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6939 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6940 s->rsakeydata = snewn(s->rsakeylen, char);
6941 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6944 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6946 sfree(s->rsakeydata);
6947 bombout(("unable to parse RSA public key from server"));
6951 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6954 * Next, set up a shared secret K, of precisely KLEN -
6955 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6956 * RSA key modulus and HLEN is the bit length of the hash
6960 int klen = ssh_rsakex_klen(s->rsakey);
6961 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6963 unsigned char *kstr1, *kstr2, *outstr;
6964 int kstr1len, kstr2len, outstrlen;
6966 s->K = bn_power_2(nbits - 1);
6968 for (i = 0; i < nbits; i++) {
6970 byte = random_byte();
6972 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6976 * Encode this as an mpint.
6978 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6979 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6980 PUT_32BIT(kstr2, kstr1len);
6981 memcpy(kstr2 + 4, kstr1, kstr1len);
6984 * Encrypt it with the given RSA key.
6986 outstrlen = (klen + 7) / 8;
6987 outstr = snewn(outstrlen, unsigned char);
6988 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6989 outstr, outstrlen, s->rsakey);
6992 * And send it off in a return packet.
6994 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6995 ssh2_pkt_addstring_start(s->pktout);
6996 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6997 ssh2_pkt_send_noqueue(ssh, s->pktout);
6999 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7006 ssh_rsakex_freekey(s->rsakey);
7008 crWaitUntilV(pktin);
7009 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7010 sfree(s->rsakeydata);
7011 bombout(("expected signature packet from server"));
7015 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7017 sfree(s->rsakeydata);
7020 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7021 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7022 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7024 ssh->kex_ctx = NULL;
7027 debug(("Exchange hash is:\n"));
7028 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7032 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7033 (char *)s->exchange_hash,
7034 ssh->kex->hash->hlen)) {
7035 bombout(("Server's host key did not match the signature supplied"));
7039 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7040 if (!s->got_session_id) {
7042 * Authenticate remote host: verify host key. (We've already
7043 * checked the signature of the exchange hash.)
7045 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
7046 logevent("Host key fingerprint is:");
7047 logevent(s->fingerprint);
7048 /* First check against manually configured host keys. */
7049 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7050 ssh->hostkey, s->hkey);
7051 if (s->dlgret == 0) { /* did not match */
7052 bombout(("Host key did not appear in manually configured list"));
7054 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7055 ssh_set_frozen(ssh, 1);
7056 s->dlgret = verify_ssh_host_key(ssh->frontend,
7057 ssh->savedhost, ssh->savedport,
7058 ssh->hostkey->keytype, s->keystr,
7060 ssh_dialog_callback, ssh);
7061 if (s->dlgret < 0) {
7065 bombout(("Unexpected data from server while waiting"
7066 " for user host key response"));
7069 } while (pktin || inlen > 0);
7070 s->dlgret = ssh->user_response;
7072 ssh_set_frozen(ssh, 0);
7073 if (s->dlgret == 0) {
7074 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7079 sfree(s->fingerprint);
7081 * Save this host key, to check against the one presented in
7082 * subsequent rekeys.
7084 ssh->hostkey_str = s->keystr;
7087 * In a rekey, we never present an interactive host key
7088 * verification request to the user. Instead, we simply
7089 * enforce that the key we're seeing this time is identical to
7090 * the one we saw before.
7092 if (strcmp(ssh->hostkey_str, s->keystr)) {
7093 bombout(("Host key was different in repeat key exchange"));
7098 ssh->hostkey->freekey(s->hkey);
7101 * The exchange hash from the very first key exchange is also
7102 * the session id, used in session key construction and
7105 if (!s->got_session_id) {
7106 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7107 memcpy(ssh->v2_session_id, s->exchange_hash,
7108 sizeof(s->exchange_hash));
7109 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7110 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7111 s->got_session_id = TRUE;
7115 * Send SSH2_MSG_NEWKEYS.
7117 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7118 ssh2_pkt_send_noqueue(ssh, s->pktout);
7119 ssh->outgoing_data_size = 0; /* start counting from here */
7122 * We've sent client NEWKEYS, so create and initialise
7123 * client-to-server session keys.
7125 if (ssh->cs_cipher_ctx)
7126 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7127 ssh->cscipher = s->cscipher_tobe;
7128 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7130 if (ssh->cs_mac_ctx)
7131 ssh->csmac->free_context(ssh->cs_mac_ctx);
7132 ssh->csmac = s->csmac_tobe;
7133 ssh->csmac_etm = s->csmac_etm_tobe;
7134 ssh->cs_mac_ctx = ssh->csmac->make_context();
7136 if (ssh->cs_comp_ctx)
7137 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7138 ssh->cscomp = s->cscomp_tobe;
7139 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7142 * Set IVs on client-to-server keys. Here we use the exchange
7143 * hash from the _first_ key exchange.
7146 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7147 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7148 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
7149 assert((ssh->cscipher->keylen+7) / 8 <=
7150 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7151 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
7152 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
7153 assert(ssh->cscipher->blksize <=
7154 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7155 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
7156 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
7157 assert(ssh->csmac->len <=
7158 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7159 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
7160 smemclr(keyspace, sizeof(keyspace));
7163 logeventf(ssh, "Initialised %.200s client->server encryption",
7164 ssh->cscipher->text_name);
7165 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s",
7166 ssh->csmac->text_name,
7167 ssh->csmac_etm ? " (in ETM mode)" : "");
7168 if (ssh->cscomp->text_name)
7169 logeventf(ssh, "Initialised %s compression",
7170 ssh->cscomp->text_name);
7173 * Now our end of the key exchange is complete, we can send all
7174 * our queued higher-layer packets.
7176 ssh->queueing = FALSE;
7177 ssh2_pkt_queuesend(ssh);
7180 * Expect SSH2_MSG_NEWKEYS from server.
7182 crWaitUntilV(pktin);
7183 if (pktin->type != SSH2_MSG_NEWKEYS) {
7184 bombout(("expected new-keys packet from server"));
7187 ssh->incoming_data_size = 0; /* start counting from here */
7190 * We've seen server NEWKEYS, so create and initialise
7191 * server-to-client session keys.
7193 if (ssh->sc_cipher_ctx)
7194 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7195 ssh->sccipher = s->sccipher_tobe;
7196 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7198 if (ssh->sc_mac_ctx)
7199 ssh->scmac->free_context(ssh->sc_mac_ctx);
7200 ssh->scmac = s->scmac_tobe;
7201 ssh->scmac_etm = s->scmac_etm_tobe;
7202 ssh->sc_mac_ctx = ssh->scmac->make_context();
7204 if (ssh->sc_comp_ctx)
7205 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7206 ssh->sccomp = s->sccomp_tobe;
7207 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7210 * Set IVs on server-to-client keys. Here we use the exchange
7211 * hash from the _first_ key exchange.
7214 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
7215 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7216 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
7217 assert((ssh->sccipher->keylen+7) / 8 <=
7218 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7219 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
7220 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
7221 assert(ssh->sccipher->blksize <=
7222 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7223 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
7224 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
7225 assert(ssh->scmac->len <=
7226 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
7227 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
7228 smemclr(keyspace, sizeof(keyspace));
7230 logeventf(ssh, "Initialised %.200s server->client encryption",
7231 ssh->sccipher->text_name);
7232 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s",
7233 ssh->scmac->text_name,
7234 ssh->scmac_etm ? " (in ETM mode)" : "");
7235 if (ssh->sccomp->text_name)
7236 logeventf(ssh, "Initialised %s decompression",
7237 ssh->sccomp->text_name);
7240 * Free shared secret.
7245 * Key exchange is over. Loop straight back round if we have a
7246 * deferred rekey reason.
7248 if (ssh->deferred_rekey_reason) {
7249 logevent(ssh->deferred_rekey_reason);
7251 ssh->deferred_rekey_reason = NULL;
7252 goto begin_key_exchange;
7256 * Otherwise, schedule a timer for our next rekey.
7258 ssh->kex_in_progress = FALSE;
7259 ssh->last_rekey = GETTICKCOUNT();
7260 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7261 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7265 * Now we're encrypting. Begin returning 1 to the protocol main
7266 * function so that other things can run on top of the
7267 * transport. If we ever see a KEXINIT, we must go back to the
7270 * We _also_ go back to the start if we see pktin==NULL and
7271 * inlen negative, because this is a special signal meaning
7272 * `initiate client-driven rekey', and `in' contains a message
7273 * giving the reason for the rekey.
7275 * inlen==-1 means always initiate a rekey;
7276 * inlen==-2 means that userauth has completed successfully and
7277 * we should consider rekeying (for delayed compression).
7279 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7280 (!pktin && inlen < 0))) {
7282 if (!ssh->protocol_initial_phase_done) {
7283 ssh->protocol_initial_phase_done = TRUE;
7285 * Allow authconn to initialise itself.
7287 do_ssh2_authconn(ssh, NULL, 0, NULL);
7292 logevent("Server initiated key re-exchange");
7296 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7297 * delayed compression, if it's available.
7299 * draft-miller-secsh-compression-delayed-00 says that you
7300 * negotiate delayed compression in the first key exchange, and
7301 * both sides start compressing when the server has sent
7302 * USERAUTH_SUCCESS. This has a race condition -- the server
7303 * can't know when the client has seen it, and thus which incoming
7304 * packets it should treat as compressed.
7306 * Instead, we do the initial key exchange without offering the
7307 * delayed methods, but note if the server offers them; when we
7308 * get here, if a delayed method was available that was higher
7309 * on our list than what we got, we initiate a rekey in which we
7310 * _do_ list the delayed methods (and hopefully get it as a
7311 * result). Subsequent rekeys will do the same.
7313 assert(!s->userauth_succeeded); /* should only happen once */
7314 s->userauth_succeeded = TRUE;
7315 if (!s->pending_compression)
7316 /* Can't see any point rekeying. */
7317 goto wait_for_rekey; /* this is utterly horrid */
7318 /* else fall through to rekey... */
7319 s->pending_compression = FALSE;
7322 * Now we've decided to rekey.
7324 * Special case: if the server bug is set that doesn't
7325 * allow rekeying, we give a different log message and
7326 * continue waiting. (If such a server _initiates_ a rekey,
7327 * we process it anyway!)
7329 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7330 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7332 /* Reset the counters, so that at least this message doesn't
7333 * hit the event log _too_ often. */
7334 ssh->outgoing_data_size = 0;
7335 ssh->incoming_data_size = 0;
7336 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7338 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7341 goto wait_for_rekey; /* this is still utterly horrid */
7343 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7346 goto begin_key_exchange;
7352 * Add data to an SSH-2 channel output buffer.
7354 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7357 bufchain_add(&c->v.v2.outbuffer, buf, len);
7361 * Attempt to send data on an SSH-2 channel.
7363 static int ssh2_try_send(struct ssh_channel *c)
7366 struct Packet *pktout;
7369 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7372 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7373 if ((unsigned)len > c->v.v2.remwindow)
7374 len = c->v.v2.remwindow;
7375 if ((unsigned)len > c->v.v2.remmaxpkt)
7376 len = c->v.v2.remmaxpkt;
7377 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7378 ssh2_pkt_adduint32(pktout, c->remoteid);
7379 ssh2_pkt_addstring_start(pktout);
7380 ssh2_pkt_addstring_data(pktout, data, len);
7381 ssh2_pkt_send(ssh, pktout);
7382 bufchain_consume(&c->v.v2.outbuffer, len);
7383 c->v.v2.remwindow -= len;
7387 * After having sent as much data as we can, return the amount
7390 ret = bufchain_size(&c->v.v2.outbuffer);
7393 * And if there's no data pending but we need to send an EOF, send
7396 if (!ret && c->pending_eof)
7397 ssh_channel_try_eof(c);
7402 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7405 if (c->closes & CLOSES_SENT_EOF)
7406 return; /* don't send on channels we've EOFed */
7407 bufsize = ssh2_try_send(c);
7410 case CHAN_MAINSESSION:
7411 /* stdin need not receive an unthrottle
7412 * notification since it will be polled */
7415 x11_unthrottle(c->u.x11.xconn);
7418 /* agent sockets are request/response and need no
7419 * buffer management */
7422 pfd_unthrottle(c->u.pfd.pf);
7428 static int ssh_is_simple(Ssh ssh)
7431 * We use the 'simple' variant of the SSH protocol if we're asked
7432 * to, except not if we're also doing connection-sharing (either
7433 * tunnelling our packets over an upstream or expecting to be
7434 * tunnelled over ourselves), since then the assumption that we
7435 * have only one channel to worry about is not true after all.
7437 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7438 !ssh->bare_connection && !ssh->connshare);
7442 * Set up most of a new ssh_channel for SSH-2.
7444 static void ssh2_channel_init(struct ssh_channel *c)
7447 c->localid = alloc_channel_id(ssh);
7449 c->pending_eof = FALSE;
7450 c->throttling_conn = FALSE;
7451 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7452 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7453 c->v.v2.chanreq_head = NULL;
7454 c->v.v2.throttle_state = UNTHROTTLED;
7455 bufchain_init(&c->v.v2.outbuffer);
7459 * Construct the common parts of a CHANNEL_OPEN.
7461 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7463 struct Packet *pktout;
7465 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7466 ssh2_pkt_addstring(pktout, type);
7467 ssh2_pkt_adduint32(pktout, c->localid);
7468 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7469 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7474 * CHANNEL_FAILURE doesn't come with any indication of what message
7475 * caused it, so we have to keep track of the outstanding
7476 * CHANNEL_REQUESTs ourselves.
7478 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7479 cchandler_fn_t handler, void *ctx)
7481 struct outstanding_channel_request *ocr =
7482 snew(struct outstanding_channel_request);
7484 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7485 ocr->handler = handler;
7488 if (!c->v.v2.chanreq_head)
7489 c->v.v2.chanreq_head = ocr;
7491 c->v.v2.chanreq_tail->next = ocr;
7492 c->v.v2.chanreq_tail = ocr;
7496 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7497 * NULL then a reply will be requested and the handler will be called
7498 * when it arrives. The returned packet is ready to have any
7499 * request-specific data added and be sent. Note that if a handler is
7500 * provided, it's essential that the request actually be sent.
7502 * The handler will usually be passed the response packet in pktin. If
7503 * pktin is NULL, this means that no reply will ever be forthcoming
7504 * (e.g. because the entire connection is being destroyed, or because
7505 * the server initiated channel closure before we saw the response)
7506 * and the handler should free any storage it's holding.
7508 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7509 cchandler_fn_t handler, void *ctx)
7511 struct Packet *pktout;
7513 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7514 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7515 ssh2_pkt_adduint32(pktout, c->remoteid);
7516 ssh2_pkt_addstring(pktout, type);
7517 ssh2_pkt_addbool(pktout, handler != NULL);
7518 if (handler != NULL)
7519 ssh2_queue_chanreq_handler(c, handler, ctx);
7524 * Potentially enlarge the window on an SSH-2 channel.
7526 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7528 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7533 * Never send WINDOW_ADJUST for a channel that the remote side has
7534 * already sent EOF on; there's no point, since it won't be
7535 * sending any more data anyway. Ditto if _we've_ already sent
7538 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7542 * Also, never widen the window for an X11 channel when we're
7543 * still waiting to see its initial auth and may yet hand it off
7546 if (c->type == CHAN_X11 && c->u.x11.initial)
7550 * If the remote end has a habit of ignoring maxpkt, limit the
7551 * window so that it has no choice (assuming it doesn't ignore the
7554 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7555 newwin = OUR_V2_MAXPKT;
7558 * Only send a WINDOW_ADJUST if there's significantly more window
7559 * available than the other end thinks there is. This saves us
7560 * sending a WINDOW_ADJUST for every character in a shell session.
7562 * "Significant" is arbitrarily defined as half the window size.
7564 if (newwin / 2 >= c->v.v2.locwindow) {
7565 struct Packet *pktout;
7569 * In order to keep track of how much window the client
7570 * actually has available, we'd like it to acknowledge each
7571 * WINDOW_ADJUST. We can't do that directly, so we accompany
7572 * it with a CHANNEL_REQUEST that has to be acknowledged.
7574 * This is only necessary if we're opening the window wide.
7575 * If we're not, then throughput is being constrained by
7576 * something other than the maximum window size anyway.
7578 if (newwin == c->v.v2.locmaxwin &&
7579 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7580 up = snew(unsigned);
7581 *up = newwin - c->v.v2.locwindow;
7582 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7583 ssh2_handle_winadj_response, up);
7584 ssh2_pkt_send(ssh, pktout);
7586 if (c->v.v2.throttle_state != UNTHROTTLED)
7587 c->v.v2.throttle_state = UNTHROTTLING;
7589 /* Pretend the WINDOW_ADJUST was acked immediately. */
7590 c->v.v2.remlocwin = newwin;
7591 c->v.v2.throttle_state = THROTTLED;
7593 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7594 ssh2_pkt_adduint32(pktout, c->remoteid);
7595 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7596 ssh2_pkt_send(ssh, pktout);
7597 c->v.v2.locwindow = newwin;
7602 * Find the channel associated with a message. If there's no channel,
7603 * or it's not properly open, make a noise about it and return NULL.
7605 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7607 unsigned localid = ssh_pkt_getuint32(pktin);
7608 struct ssh_channel *c;
7610 c = find234(ssh->channels, &localid, ssh_channelfind);
7612 (c->type != CHAN_SHARING && c->halfopen &&
7613 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7614 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7615 char *buf = dupprintf("Received %s for %s channel %u",
7616 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7618 c ? "half-open" : "nonexistent", localid);
7619 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7626 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7627 struct Packet *pktin, void *ctx)
7629 unsigned *sizep = ctx;
7632 * Winadj responses should always be failures. However, at least
7633 * one server ("boks_sshd") is known to return SUCCESS for channel
7634 * requests it's never heard of, such as "winadj@putty". Raised
7635 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7636 * life, we don't worry about what kind of response we got.
7639 c->v.v2.remlocwin += *sizep;
7642 * winadj messages are only sent when the window is fully open, so
7643 * if we get an ack of one, we know any pending unthrottle is
7646 if (c->v.v2.throttle_state == UNTHROTTLING)
7647 c->v.v2.throttle_state = UNTHROTTLED;
7650 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7652 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7653 struct outstanding_channel_request *ocr;
7656 if (c->type == CHAN_SHARING) {
7657 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7658 pktin->body, pktin->length);
7661 ocr = c->v.v2.chanreq_head;
7663 ssh2_msg_unexpected(ssh, pktin);
7666 ocr->handler(c, pktin, ocr->ctx);
7667 c->v.v2.chanreq_head = ocr->next;
7670 * We may now initiate channel-closing procedures, if that
7671 * CHANNEL_REQUEST was the last thing outstanding before we send
7674 ssh2_channel_check_close(c);
7677 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7679 struct ssh_channel *c;
7680 c = ssh2_channel_msg(ssh, pktin);
7683 if (c->type == CHAN_SHARING) {
7684 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7685 pktin->body, pktin->length);
7688 if (!(c->closes & CLOSES_SENT_EOF)) {
7689 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7690 ssh2_try_send_and_unthrottle(ssh, c);
7694 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7698 struct ssh_channel *c;
7699 c = ssh2_channel_msg(ssh, pktin);
7702 if (c->type == CHAN_SHARING) {
7703 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7704 pktin->body, pktin->length);
7707 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7708 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7709 return; /* extended but not stderr */
7710 ssh_pkt_getstring(pktin, &data, &length);
7713 c->v.v2.locwindow -= length;
7714 c->v.v2.remlocwin -= length;
7716 case CHAN_MAINSESSION:
7718 from_backend(ssh->frontend, pktin->type ==
7719 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7723 bufsize = x11_send(c->u.x11.xconn, data, length);
7726 bufsize = pfd_send(c->u.pfd.pf, data, length);
7729 while (length > 0) {
7730 if (c->u.a.lensofar < 4) {
7731 unsigned int l = min(4 - c->u.a.lensofar,
7733 memcpy(c->u.a.msglen + c->u.a.lensofar,
7737 c->u.a.lensofar += l;
7739 if (c->u.a.lensofar == 4) {
7741 4 + GET_32BIT(c->u.a.msglen);
7742 c->u.a.message = snewn(c->u.a.totallen,
7744 memcpy(c->u.a.message, c->u.a.msglen, 4);
7746 if (c->u.a.lensofar >= 4 && length > 0) {
7748 min(c->u.a.totallen - c->u.a.lensofar,
7750 memcpy(c->u.a.message + c->u.a.lensofar,
7754 c->u.a.lensofar += l;
7756 if (c->u.a.lensofar == c->u.a.totallen) {
7759 c->u.a.outstanding_requests++;
7760 if (agent_query(c->u.a.message,
7763 ssh_agentf_callback, c))
7764 ssh_agentf_callback(c, reply, replylen);
7765 sfree(c->u.a.message);
7766 c->u.a.message = NULL;
7767 c->u.a.lensofar = 0;
7774 * If it looks like the remote end hit the end of its window,
7775 * and we didn't want it to do that, think about using a
7778 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7779 c->v.v2.locmaxwin < 0x40000000)
7780 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7782 * If we are not buffering too much data,
7783 * enlarge the window again at the remote side.
7784 * If we are buffering too much, we may still
7785 * need to adjust the window if the server's
7788 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7789 c->v.v2.locmaxwin - bufsize : 0);
7791 * If we're either buffering way too much data, or if we're
7792 * buffering anything at all and we're in "simple" mode,
7793 * throttle the whole channel.
7795 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7796 && !c->throttling_conn) {
7797 c->throttling_conn = 1;
7798 ssh_throttle_conn(ssh, +1);
7803 static void ssh_check_termination(Ssh ssh)
7805 if (ssh->version == 2 &&
7806 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7807 count234(ssh->channels) == 0 &&
7808 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7810 * We used to send SSH_MSG_DISCONNECT here, because I'd
7811 * believed that _every_ conforming SSH-2 connection had to
7812 * end with a disconnect being sent by at least one side;
7813 * apparently I was wrong and it's perfectly OK to
7814 * unceremoniously slam the connection shut when you're done,
7815 * and indeed OpenSSH feels this is more polite than sending a
7816 * DISCONNECT. So now we don't.
7818 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7822 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7824 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7827 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7829 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7830 ssh_check_termination(ssh);
7833 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7838 va_start(ap, logfmt);
7839 buf = dupvprintf(logfmt, ap);
7842 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7844 logeventf(ssh, "Connection sharing: %s", buf);
7848 static void ssh_channel_destroy(struct ssh_channel *c)
7853 case CHAN_MAINSESSION:
7854 ssh->mainchan = NULL;
7855 update_specials_menu(ssh->frontend);
7858 if (c->u.x11.xconn != NULL)
7859 x11_close(c->u.x11.xconn);
7860 logevent("Forwarded X11 connection terminated");
7863 sfree(c->u.a.message);
7866 if (c->u.pfd.pf != NULL)
7867 pfd_close(c->u.pfd.pf);
7868 logevent("Forwarded port closed");
7872 del234(ssh->channels, c);
7873 if (ssh->version == 2) {
7874 bufchain_clear(&c->v.v2.outbuffer);
7875 assert(c->v.v2.chanreq_head == NULL);
7880 * If that was the last channel left open, we might need to
7883 ssh_check_termination(ssh);
7886 static void ssh2_channel_check_close(struct ssh_channel *c)
7889 struct Packet *pktout;
7893 * If we've sent out our own CHANNEL_OPEN but not yet seen
7894 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7895 * it's too early to be sending close messages of any kind.
7900 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7901 c->type == CHAN_ZOMBIE) &&
7902 !c->v.v2.chanreq_head &&
7903 !(c->closes & CLOSES_SENT_CLOSE)) {
7905 * We have both sent and received EOF (or the channel is a
7906 * zombie), and we have no outstanding channel requests, which
7907 * means the channel is in final wind-up. But we haven't sent
7908 * CLOSE, so let's do so now.
7910 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7911 ssh2_pkt_adduint32(pktout, c->remoteid);
7912 ssh2_pkt_send(ssh, pktout);
7913 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7916 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7917 assert(c->v.v2.chanreq_head == NULL);
7919 * We have both sent and received CLOSE, which means we're
7920 * completely done with the channel.
7922 ssh_channel_destroy(c);
7926 static void ssh2_channel_got_eof(struct ssh_channel *c)
7928 if (c->closes & CLOSES_RCVD_EOF)
7929 return; /* already seen EOF */
7930 c->closes |= CLOSES_RCVD_EOF;
7932 if (c->type == CHAN_X11) {
7933 x11_send_eof(c->u.x11.xconn);
7934 } else if (c->type == CHAN_AGENT) {
7935 if (c->u.a.outstanding_requests == 0) {
7936 /* Manufacture an outgoing EOF in response to the incoming one. */
7937 sshfwd_write_eof(c);
7939 } else if (c->type == CHAN_SOCKDATA) {
7940 pfd_send_eof(c->u.pfd.pf);
7941 } else if (c->type == CHAN_MAINSESSION) {
7944 if (!ssh->sent_console_eof &&
7945 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7947 * Either from_backend_eof told us that the front end
7948 * wants us to close the outgoing side of the connection
7949 * as soon as we see EOF from the far end, or else we've
7950 * unilaterally decided to do that because we've allocated
7951 * a remote pty and hence EOF isn't a particularly
7952 * meaningful concept.
7954 sshfwd_write_eof(c);
7956 ssh->sent_console_eof = TRUE;
7959 ssh2_channel_check_close(c);
7962 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7964 struct ssh_channel *c;
7966 c = ssh2_channel_msg(ssh, pktin);
7969 if (c->type == CHAN_SHARING) {
7970 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7971 pktin->body, pktin->length);
7974 ssh2_channel_got_eof(c);
7977 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7979 struct ssh_channel *c;
7981 c = ssh2_channel_msg(ssh, pktin);
7984 if (c->type == CHAN_SHARING) {
7985 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7986 pktin->body, pktin->length);
7991 * When we receive CLOSE on a channel, we assume it comes with an
7992 * implied EOF if we haven't seen EOF yet.
7994 ssh2_channel_got_eof(c);
7996 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7998 * It also means we stop expecting to see replies to any
7999 * outstanding channel requests, so clean those up too.
8000 * (ssh_chanreq_init will enforce by assertion that we don't
8001 * subsequently put anything back on this list.)
8003 while (c->v.v2.chanreq_head) {
8004 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8005 ocr->handler(c, NULL, ocr->ctx);
8006 c->v.v2.chanreq_head = ocr->next;
8012 * And we also send an outgoing EOF, if we haven't already, on the
8013 * assumption that CLOSE is a pretty forceful announcement that
8014 * the remote side is doing away with the entire channel. (If it
8015 * had wanted to send us EOF and continue receiving data from us,
8016 * it would have just sent CHANNEL_EOF.)
8018 if (!(c->closes & CLOSES_SENT_EOF)) {
8020 * Make sure we don't read any more from whatever our local
8021 * data source is for this channel.
8024 case CHAN_MAINSESSION:
8025 ssh->send_ok = 0; /* stop trying to read from stdin */
8028 x11_override_throttle(c->u.x11.xconn, 1);
8031 pfd_override_throttle(c->u.pfd.pf, 1);
8036 * Abandon any buffered data we still wanted to send to this
8037 * channel. Receiving a CHANNEL_CLOSE is an indication that
8038 * the server really wants to get on and _destroy_ this
8039 * channel, and it isn't going to send us any further
8040 * WINDOW_ADJUSTs to permit us to send pending stuff.
8042 bufchain_clear(&c->v.v2.outbuffer);
8045 * Send outgoing EOF.
8047 sshfwd_write_eof(c);
8051 * Now process the actual close.
8053 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8054 c->closes |= CLOSES_RCVD_CLOSE;
8055 ssh2_channel_check_close(c);
8059 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8061 struct ssh_channel *c;
8063 c = ssh2_channel_msg(ssh, pktin);
8066 if (c->type == CHAN_SHARING) {
8067 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8068 pktin->body, pktin->length);
8071 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8072 c->remoteid = ssh_pkt_getuint32(pktin);
8073 c->halfopen = FALSE;
8074 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8075 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8077 if (c->type == CHAN_SOCKDATA_DORMANT) {
8078 c->type = CHAN_SOCKDATA;
8080 pfd_confirm(c->u.pfd.pf);
8081 } else if (c->type == CHAN_ZOMBIE) {
8083 * This case can occur if a local socket error occurred
8084 * between us sending out CHANNEL_OPEN and receiving
8085 * OPEN_CONFIRMATION. In this case, all we can do is
8086 * immediately initiate close proceedings now that we know the
8087 * server's id to put in the close message.
8089 ssh2_channel_check_close(c);
8092 * We never expect to receive OPEN_CONFIRMATION for any
8093 * *other* channel type (since only local-to-remote port
8094 * forwardings cause us to send CHANNEL_OPEN after the main
8095 * channel is live - all other auxiliary channel types are
8096 * initiated from the server end). It's safe to enforce this
8097 * by assertion rather than by ssh_disconnect, because the
8098 * real point is that we never constructed a half-open channel
8099 * structure in the first place with any type other than the
8102 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8106 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8109 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8111 static const char *const reasons[] = {
8112 "<unknown reason code>",
8113 "Administratively prohibited",
8115 "Unknown channel type",
8116 "Resource shortage",
8118 unsigned reason_code;
8119 char *reason_string;
8121 struct ssh_channel *c;
8123 c = ssh2_channel_msg(ssh, pktin);
8126 if (c->type == CHAN_SHARING) {
8127 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8128 pktin->body, pktin->length);
8131 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8133 if (c->type == CHAN_SOCKDATA_DORMANT) {
8134 reason_code = ssh_pkt_getuint32(pktin);
8135 if (reason_code >= lenof(reasons))
8136 reason_code = 0; /* ensure reasons[reason_code] in range */
8137 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8138 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8139 reasons[reason_code], reason_length, reason_string);
8141 pfd_close(c->u.pfd.pf);
8142 } else if (c->type == CHAN_ZOMBIE) {
8144 * This case can occur if a local socket error occurred
8145 * between us sending out CHANNEL_OPEN and receiving
8146 * OPEN_FAILURE. In this case, we need do nothing except allow
8147 * the code below to throw the half-open channel away.
8151 * We never expect to receive OPEN_FAILURE for any *other*
8152 * channel type (since only local-to-remote port forwardings
8153 * cause us to send CHANNEL_OPEN after the main channel is
8154 * live - all other auxiliary channel types are initiated from
8155 * the server end). It's safe to enforce this by assertion
8156 * rather than by ssh_disconnect, because the real point is
8157 * that we never constructed a half-open channel structure in
8158 * the first place with any type other than the above.
8160 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8163 del234(ssh->channels, c);
8167 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8170 int typelen, want_reply;
8171 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8172 struct ssh_channel *c;
8173 struct Packet *pktout;
8175 c = ssh2_channel_msg(ssh, pktin);
8178 if (c->type == CHAN_SHARING) {
8179 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8180 pktin->body, pktin->length);
8183 ssh_pkt_getstring(pktin, &type, &typelen);
8184 want_reply = ssh2_pkt_getbool(pktin);
8186 if (c->closes & CLOSES_SENT_CLOSE) {
8188 * We don't reply to channel requests after we've sent
8189 * CHANNEL_CLOSE for the channel, because our reply might
8190 * cross in the network with the other side's CHANNEL_CLOSE
8191 * and arrive after they have wound the channel up completely.
8197 * Having got the channel number, we now look at
8198 * the request type string to see if it's something
8201 if (c == ssh->mainchan) {
8203 * We recognise "exit-status" and "exit-signal" on
8204 * the primary channel.
8206 if (typelen == 11 &&
8207 !memcmp(type, "exit-status", 11)) {
8209 ssh->exitcode = ssh_pkt_getuint32(pktin);
8210 logeventf(ssh, "Server sent command exit status %d",
8212 reply = SSH2_MSG_CHANNEL_SUCCESS;
8214 } else if (typelen == 11 &&
8215 !memcmp(type, "exit-signal", 11)) {
8217 int is_plausible = TRUE, is_int = FALSE;
8218 char *fmt_sig = "", *fmt_msg = "";
8220 int msglen = 0, core = FALSE;
8221 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8222 * provide an `int' for the signal, despite its
8223 * having been a `string' in the drafts of RFC 4254 since at
8224 * least 2001. (Fixed in session.c 1.147.) Try to
8225 * infer which we can safely parse it as. */
8227 unsigned char *p = pktin->body +
8229 long len = pktin->length - pktin->savedpos;
8230 unsigned long num = GET_32BIT(p); /* what is it? */
8231 /* If it's 0, it hardly matters; assume string */
8235 int maybe_int = FALSE, maybe_str = FALSE;
8236 #define CHECK_HYPOTHESIS(offset, result) \
8239 int q = toint(offset); \
8240 if (q >= 0 && q+4 <= len) { \
8241 q = toint(q + 4 + GET_32BIT(p+q)); \
8242 if (q >= 0 && q+4 <= len && \
8243 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8248 CHECK_HYPOTHESIS(4+1, maybe_int);
8249 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8250 #undef CHECK_HYPOTHESIS
8251 if (maybe_int && !maybe_str)
8253 else if (!maybe_int && maybe_str)
8256 /* Crikey. Either or neither. Panic. */
8257 is_plausible = FALSE;
8260 ssh->exitcode = 128; /* means `unknown signal' */
8263 /* Old non-standard OpenSSH. */
8264 int signum = ssh_pkt_getuint32(pktin);
8265 fmt_sig = dupprintf(" %d", signum);
8266 ssh->exitcode = 128 + signum;
8268 /* As per RFC 4254. */
8271 ssh_pkt_getstring(pktin, &sig, &siglen);
8272 /* Signal name isn't supposed to be blank, but
8273 * let's cope gracefully if it is. */
8275 fmt_sig = dupprintf(" \"%.*s\"",
8280 * Really hideous method of translating the
8281 * signal description back into a locally
8282 * meaningful number.
8287 #define TRANSLATE_SIGNAL(s) \
8288 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8289 ssh->exitcode = 128 + SIG ## s
8291 TRANSLATE_SIGNAL(ABRT);
8294 TRANSLATE_SIGNAL(ALRM);
8297 TRANSLATE_SIGNAL(FPE);
8300 TRANSLATE_SIGNAL(HUP);
8303 TRANSLATE_SIGNAL(ILL);
8306 TRANSLATE_SIGNAL(INT);
8309 TRANSLATE_SIGNAL(KILL);
8312 TRANSLATE_SIGNAL(PIPE);
8315 TRANSLATE_SIGNAL(QUIT);
8318 TRANSLATE_SIGNAL(SEGV);
8321 TRANSLATE_SIGNAL(TERM);
8324 TRANSLATE_SIGNAL(USR1);
8327 TRANSLATE_SIGNAL(USR2);
8329 #undef TRANSLATE_SIGNAL
8331 ssh->exitcode = 128;
8333 core = ssh2_pkt_getbool(pktin);
8334 ssh_pkt_getstring(pktin, &msg, &msglen);
8336 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8338 /* ignore lang tag */
8339 } /* else don't attempt to parse */
8340 logeventf(ssh, "Server exited on signal%s%s%s",
8341 fmt_sig, core ? " (core dumped)" : "",
8343 if (*fmt_sig) sfree(fmt_sig);
8344 if (*fmt_msg) sfree(fmt_msg);
8345 reply = SSH2_MSG_CHANNEL_SUCCESS;
8350 * This is a channel request we don't know
8351 * about, so we now either ignore the request
8352 * or respond with CHANNEL_FAILURE, depending
8355 reply = SSH2_MSG_CHANNEL_FAILURE;
8358 pktout = ssh2_pkt_init(reply);
8359 ssh2_pkt_adduint32(pktout, c->remoteid);
8360 ssh2_pkt_send(ssh, pktout);
8364 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8367 int typelen, want_reply;
8368 struct Packet *pktout;
8370 ssh_pkt_getstring(pktin, &type, &typelen);
8371 want_reply = ssh2_pkt_getbool(pktin);
8374 * We currently don't support any global requests
8375 * at all, so we either ignore the request or
8376 * respond with REQUEST_FAILURE, depending on
8380 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8381 ssh2_pkt_send(ssh, pktout);
8385 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8389 struct X11FakeAuth *auth;
8392 * Make up a new set of fake X11 auth data, and add it to the tree
8393 * of currently valid ones with an indication of the sharing
8394 * context that it's relevant to.
8396 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8397 auth->share_cs = share_cs;
8398 auth->share_chan = share_chan;
8403 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8405 del234(ssh->x11authtree, auth);
8406 x11_free_fake_auth(auth);
8409 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8417 struct ssh_channel *c;
8418 unsigned remid, winsize, pktsize;
8419 unsigned our_winsize_override = 0;
8420 struct Packet *pktout;
8422 ssh_pkt_getstring(pktin, &type, &typelen);
8423 c = snew(struct ssh_channel);
8426 remid = ssh_pkt_getuint32(pktin);
8427 winsize = ssh_pkt_getuint32(pktin);
8428 pktsize = ssh_pkt_getuint32(pktin);
8430 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8433 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8434 addrstr = snewn(peeraddrlen+1, char);
8435 memcpy(addrstr, peeraddr, peeraddrlen);
8436 addrstr[peeraddrlen] = '\0';
8437 peerport = ssh_pkt_getuint32(pktin);
8439 logeventf(ssh, "Received X11 connect request from %s:%d",
8442 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8443 error = "X11 forwarding is not enabled";
8445 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8448 c->u.x11.initial = TRUE;
8451 * If we are a connection-sharing upstream, then we should
8452 * initially present a very small window, adequate to take
8453 * the X11 initial authorisation packet but not much more.
8454 * Downstream will then present us a larger window (by
8455 * fiat of the connection-sharing protocol) and we can
8456 * guarantee to send a positive-valued WINDOW_ADJUST.
8459 our_winsize_override = 128;
8461 logevent("Opened X11 forward channel");
8465 } else if (typelen == 15 &&
8466 !memcmp(type, "forwarded-tcpip", 15)) {
8467 struct ssh_rportfwd pf, *realpf;
8470 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8471 pf.shost = dupprintf("%.*s", shostlen, shost);
8472 pf.sport = ssh_pkt_getuint32(pktin);
8473 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8474 peerport = ssh_pkt_getuint32(pktin);
8475 realpf = find234(ssh->rportfwds, &pf, NULL);
8476 logeventf(ssh, "Received remote port %s:%d open request "
8477 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8480 if (realpf == NULL) {
8481 error = "Remote port is not recognised";
8485 if (realpf->share_ctx) {
8487 * This port forwarding is on behalf of a
8488 * connection-sharing downstream, so abandon our own
8489 * channel-open procedure and just pass the message on
8492 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8493 pktin->body, pktin->length);
8498 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8499 c, ssh->conf, realpf->pfrec->addressfamily);
8500 logeventf(ssh, "Attempting to forward remote port to "
8501 "%s:%d", realpf->dhost, realpf->dport);
8503 logeventf(ssh, "Port open failed: %s", err);
8505 error = "Port open failed";
8507 logevent("Forwarded port opened successfully");
8508 c->type = CHAN_SOCKDATA;
8511 } else if (typelen == 22 &&
8512 !memcmp(type, "auth-agent@openssh.com", 22)) {
8513 if (!ssh->agentfwd_enabled)
8514 error = "Agent forwarding is not enabled";
8516 c->type = CHAN_AGENT; /* identify channel type */
8517 c->u.a.lensofar = 0;
8518 c->u.a.message = NULL;
8519 c->u.a.outstanding_requests = 0;
8522 error = "Unsupported channel type requested";
8525 c->remoteid = remid;
8526 c->halfopen = FALSE;
8528 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8529 ssh2_pkt_adduint32(pktout, c->remoteid);
8530 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8531 ssh2_pkt_addstring(pktout, error);
8532 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8533 ssh2_pkt_send(ssh, pktout);
8534 logeventf(ssh, "Rejected channel open: %s", error);
8537 ssh2_channel_init(c);
8538 c->v.v2.remwindow = winsize;
8539 c->v.v2.remmaxpkt = pktsize;
8540 if (our_winsize_override) {
8541 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8542 our_winsize_override;
8544 add234(ssh->channels, c);
8545 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8546 ssh2_pkt_adduint32(pktout, c->remoteid);
8547 ssh2_pkt_adduint32(pktout, c->localid);
8548 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8549 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8550 ssh2_pkt_send(ssh, pktout);
8554 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8555 void *share_cs, void *share_chan,
8556 const char *peer_addr, int peer_port,
8557 int endian, int protomajor, int protominor,
8558 const void *initial_data, int initial_len)
8561 * This function is called when we've just discovered that an X
8562 * forwarding channel on which we'd been handling the initial auth
8563 * ourselves turns out to be destined for a connection-sharing
8564 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8565 * that we completely stop tracking windows and buffering data and
8566 * just pass more or less unmodified SSH messages back and forth.
8568 c->type = CHAN_SHARING;
8569 c->u.sharing.ctx = share_cs;
8570 share_setup_x11_channel(share_cs, share_chan,
8571 c->localid, c->remoteid, c->v.v2.remwindow,
8572 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8573 peer_addr, peer_port, endian,
8574 protomajor, protominor,
8575 initial_data, initial_len);
8578 void sshfwd_x11_is_local(struct ssh_channel *c)
8581 * This function is called when we've just discovered that an X
8582 * forwarding channel is _not_ destined for a connection-sharing
8583 * downstream but we're going to handle it ourselves. We stop
8584 * presenting a cautiously small window and go into ordinary data
8587 c->u.x11.initial = FALSE;
8588 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8592 * Buffer banner messages for later display at some convenient point,
8593 * if we're going to display them.
8595 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8597 /* Arbitrary limit to prevent unbounded inflation of buffer */
8598 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8599 bufchain_size(&ssh->banner) <= 131072) {
8600 char *banner = NULL;
8602 ssh_pkt_getstring(pktin, &banner, &size);
8604 bufchain_add(&ssh->banner, banner, size);
8608 /* Helper function to deal with sending tty modes for "pty-req" */
8609 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8611 struct Packet *pktout = (struct Packet *)data;
8613 unsigned int arg = 0;
8614 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8615 if (i == lenof(ssh_ttymodes)) return;
8616 switch (ssh_ttymodes[i].type) {
8618 arg = ssh_tty_parse_specchar(val);
8621 arg = ssh_tty_parse_boolean(val);
8624 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8625 ssh2_pkt_adduint32(pktout, arg);
8628 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8631 struct ssh2_setup_x11_state {
8635 struct Packet *pktout;
8636 crStateP(ssh2_setup_x11_state, ctx);
8640 logevent("Requesting X11 forwarding");
8641 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8643 ssh2_pkt_addbool(pktout, 0); /* many connections */
8644 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8645 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8646 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8647 ssh2_pkt_send(ssh, pktout);
8649 /* Wait to be called back with either a response packet, or NULL
8650 * meaning clean up and free our data */
8654 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8655 logevent("X11 forwarding enabled");
8656 ssh->X11_fwd_enabled = TRUE;
8658 logevent("X11 forwarding refused");
8664 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8667 struct ssh2_setup_agent_state {
8671 struct Packet *pktout;
8672 crStateP(ssh2_setup_agent_state, ctx);
8676 logevent("Requesting OpenSSH-style agent forwarding");
8677 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8678 ssh2_setup_agent, s);
8679 ssh2_pkt_send(ssh, pktout);
8681 /* Wait to be called back with either a response packet, or NULL
8682 * meaning clean up and free our data */
8686 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8687 logevent("Agent forwarding enabled");
8688 ssh->agentfwd_enabled = TRUE;
8690 logevent("Agent forwarding refused");
8696 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8699 struct ssh2_setup_pty_state {
8703 struct Packet *pktout;
8704 crStateP(ssh2_setup_pty_state, ctx);
8708 /* Unpick the terminal-speed string. */
8709 /* XXX perhaps we should allow no speeds to be sent. */
8710 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8711 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8712 /* Build the pty request. */
8713 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8715 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8716 ssh2_pkt_adduint32(pktout, ssh->term_width);
8717 ssh2_pkt_adduint32(pktout, ssh->term_height);
8718 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8719 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8720 ssh2_pkt_addstring_start(pktout);
8721 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8722 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8723 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8724 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8725 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8726 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8727 ssh2_pkt_send(ssh, pktout);
8728 ssh->state = SSH_STATE_INTERMED;
8730 /* Wait to be called back with either a response packet, or NULL
8731 * meaning clean up and free our data */
8735 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8736 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8737 ssh->ospeed, ssh->ispeed);
8738 ssh->got_pty = TRUE;
8740 c_write_str(ssh, "Server refused to allocate pty\r\n");
8741 ssh->editing = ssh->echoing = 1;
8748 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8751 struct ssh2_setup_env_state {
8753 int num_env, env_left, env_ok;
8756 struct Packet *pktout;
8757 crStateP(ssh2_setup_env_state, ctx);
8762 * Send environment variables.
8764 * Simplest thing here is to send all the requests at once, and
8765 * then wait for a whole bunch of successes or failures.
8771 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8773 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8774 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8775 ssh2_pkt_addstring(pktout, key);
8776 ssh2_pkt_addstring(pktout, val);
8777 ssh2_pkt_send(ssh, pktout);
8782 logeventf(ssh, "Sent %d environment variables", s->num_env);
8787 s->env_left = s->num_env;
8789 while (s->env_left > 0) {
8790 /* Wait to be called back with either a response packet,
8791 * or NULL meaning clean up and free our data */
8793 if (!pktin) goto out;
8794 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8799 if (s->env_ok == s->num_env) {
8800 logevent("All environment variables successfully set");
8801 } else if (s->env_ok == 0) {
8802 logevent("All environment variables refused");
8803 c_write_str(ssh, "Server refused to set environment variables\r\n");
8805 logeventf(ssh, "%d environment variables refused",
8806 s->num_env - s->env_ok);
8807 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8815 * Handle the SSH-2 userauth and connection layers.
8817 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8819 do_ssh2_authconn(ssh, NULL, 0, pktin);
8822 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8826 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8829 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8830 struct Packet *pktin)
8832 struct do_ssh2_authconn_state {
8836 AUTH_TYPE_PUBLICKEY,
8837 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8838 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8840 AUTH_TYPE_GSSAPI, /* always QUIET */
8841 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8842 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8844 int done_service_req;
8845 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8846 int tried_pubkey_config, done_agent;
8851 int kbd_inter_refused;
8852 int we_are_in, userauth_success;
8853 prompts_t *cur_prompt;
8858 void *publickey_blob;
8859 int publickey_bloblen;
8860 int privatekey_available, privatekey_encrypted;
8861 char *publickey_algorithm;
8862 char *publickey_comment;
8863 unsigned char agent_request[5], *agent_response, *agentp;
8864 int agent_responselen;
8865 unsigned char *pkblob_in_agent;
8867 char *pkblob, *alg, *commentp;
8868 int pklen, alglen, commentlen;
8869 int siglen, retlen, len;
8870 char *q, *agentreq, *ret;
8872 struct Packet *pktout;
8875 struct ssh_gss_library *gsslib;
8876 Ssh_gss_ctx gss_ctx;
8877 Ssh_gss_buf gss_buf;
8878 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8879 Ssh_gss_name gss_srv_name;
8880 Ssh_gss_stat gss_stat;
8883 crState(do_ssh2_authconn_state);
8887 /* Register as a handler for all the messages this coroutine handles. */
8888 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8889 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8890 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8891 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8892 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8893 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8894 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8895 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8896 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8897 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8898 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8899 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8900 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8901 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8902 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8903 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8904 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8905 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8906 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8907 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8909 s->done_service_req = FALSE;
8910 s->we_are_in = s->userauth_success = FALSE;
8911 s->agent_response = NULL;
8913 s->tried_gssapi = FALSE;
8916 if (!ssh->bare_connection) {
8917 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8919 * Request userauth protocol, and await a response to it.
8921 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8922 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8923 ssh2_pkt_send(ssh, s->pktout);
8924 crWaitUntilV(pktin);
8925 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8926 s->done_service_req = TRUE;
8928 if (!s->done_service_req) {
8930 * Request connection protocol directly, without authentication.
8932 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8933 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8934 ssh2_pkt_send(ssh, s->pktout);
8935 crWaitUntilV(pktin);
8936 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8937 s->we_are_in = TRUE; /* no auth required */
8939 bombout(("Server refused service request"));
8944 s->we_are_in = TRUE;
8947 /* Arrange to be able to deal with any BANNERs that come in.
8948 * (We do this now as packets may come in during the next bit.) */
8949 bufchain_init(&ssh->banner);
8950 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8951 ssh2_msg_userauth_banner;
8954 * Misc one-time setup for authentication.
8956 s->publickey_blob = NULL;
8957 if (!s->we_are_in) {
8960 * Load the public half of any configured public key file
8963 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8964 if (!filename_is_null(s->keyfile)) {
8966 logeventf(ssh, "Reading key file \"%.150s\"",
8967 filename_to_str(s->keyfile));
8968 keytype = key_type(s->keyfile);
8969 if (keytype == SSH_KEYTYPE_SSH2 ||
8970 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
8971 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
8974 ssh2_userkey_loadpub(s->keyfile,
8975 &s->publickey_algorithm,
8976 &s->publickey_bloblen,
8977 &s->publickey_comment, &error);
8978 if (s->publickey_blob) {
8979 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
8980 if (!s->privatekey_available)
8981 logeventf(ssh, "Key file contains public key only");
8982 s->privatekey_encrypted =
8983 ssh2_userkey_encrypted(s->keyfile, NULL);
8986 logeventf(ssh, "Unable to load key (%s)",
8988 msgbuf = dupprintf("Unable to load key file "
8989 "\"%.150s\" (%s)\r\n",
8990 filename_to_str(s->keyfile),
8992 c_write_str(ssh, msgbuf);
8997 logeventf(ssh, "Unable to use this key file (%s)",
8998 key_type_to_str(keytype));
8999 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9001 filename_to_str(s->keyfile),
9002 key_type_to_str(keytype));
9003 c_write_str(ssh, msgbuf);
9005 s->publickey_blob = NULL;
9010 * Find out about any keys Pageant has (but if there's a
9011 * public key configured, filter out all others).
9014 s->agent_response = NULL;
9015 s->pkblob_in_agent = NULL;
9016 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9020 logevent("Pageant is running. Requesting keys.");
9022 /* Request the keys held by the agent. */
9023 PUT_32BIT(s->agent_request, 1);
9024 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9025 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9026 ssh_agent_callback, ssh)) {
9030 bombout(("Unexpected data from server while"
9031 " waiting for agent response"));
9034 } while (pktin || inlen > 0);
9035 r = ssh->agent_response;
9036 s->agent_responselen = ssh->agent_response_len;
9038 s->agent_response = (unsigned char *) r;
9039 if (s->agent_response && s->agent_responselen >= 5 &&
9040 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9043 p = s->agent_response + 5;
9044 s->nkeys = toint(GET_32BIT(p));
9047 * Vet the Pageant response to ensure that the key
9048 * count and blob lengths make sense.
9051 logeventf(ssh, "Pageant response contained a negative"
9052 " key count %d", s->nkeys);
9054 goto done_agent_query;
9056 unsigned char *q = p + 4;
9057 int lenleft = s->agent_responselen - 5 - 4;
9059 for (keyi = 0; keyi < s->nkeys; keyi++) {
9060 int bloblen, commentlen;
9062 logeventf(ssh, "Pageant response was truncated");
9064 goto done_agent_query;
9066 bloblen = toint(GET_32BIT(q));
9067 if (bloblen < 0 || bloblen > lenleft) {
9068 logeventf(ssh, "Pageant response was truncated");
9070 goto done_agent_query;
9072 lenleft -= 4 + bloblen;
9074 commentlen = toint(GET_32BIT(q));
9075 if (commentlen < 0 || commentlen > lenleft) {
9076 logeventf(ssh, "Pageant response was truncated");
9078 goto done_agent_query;
9080 lenleft -= 4 + commentlen;
9081 q += 4 + commentlen;
9086 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9087 if (s->publickey_blob) {
9088 /* See if configured key is in agent. */
9089 for (keyi = 0; keyi < s->nkeys; keyi++) {
9090 s->pklen = toint(GET_32BIT(p));
9091 if (s->pklen == s->publickey_bloblen &&
9092 !memcmp(p+4, s->publickey_blob,
9093 s->publickey_bloblen)) {
9094 logeventf(ssh, "Pageant key #%d matches "
9095 "configured key file", keyi);
9097 s->pkblob_in_agent = p;
9101 p += toint(GET_32BIT(p)) + 4; /* comment */
9103 if (!s->pkblob_in_agent) {
9104 logevent("Configured key file not in Pageant");
9109 logevent("Failed to get reply from Pageant");
9117 * We repeat this whole loop, including the username prompt,
9118 * until we manage a successful authentication. If the user
9119 * types the wrong _password_, they can be sent back to the
9120 * beginning to try another username, if this is configured on.
9121 * (If they specify a username in the config, they are never
9122 * asked, even if they do give a wrong password.)
9124 * I think this best serves the needs of
9126 * - the people who have no configuration, no keys, and just
9127 * want to try repeated (username,password) pairs until they
9128 * type both correctly
9130 * - people who have keys and configuration but occasionally
9131 * need to fall back to passwords
9133 * - people with a key held in Pageant, who might not have
9134 * logged in to a particular machine before; so they want to
9135 * type a username, and then _either_ their key will be
9136 * accepted, _or_ they will type a password. If they mistype
9137 * the username they will want to be able to get back and
9140 s->got_username = FALSE;
9141 while (!s->we_are_in) {
9145 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9147 * We got a username last time round this loop, and
9148 * with change_username turned off we don't try to get
9151 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9152 int ret; /* need not be kept over crReturn */
9153 s->cur_prompt = new_prompts(ssh->frontend);
9154 s->cur_prompt->to_server = TRUE;
9155 s->cur_prompt->name = dupstr("SSH login name");
9156 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9157 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9160 crWaitUntilV(!pktin);
9161 ret = get_userpass_input(s->cur_prompt, in, inlen);
9166 * get_userpass_input() failed to get a username.
9169 free_prompts(s->cur_prompt);
9170 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9173 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9174 free_prompts(s->cur_prompt);
9177 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9178 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9179 c_write_str(ssh, stuff);
9183 s->got_username = TRUE;
9186 * Send an authentication request using method "none": (a)
9187 * just in case it succeeds, and (b) so that we know what
9188 * authentication methods we can usefully try next.
9190 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9192 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9193 ssh2_pkt_addstring(s->pktout, ssh->username);
9194 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9195 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9196 ssh2_pkt_send(ssh, s->pktout);
9197 s->type = AUTH_TYPE_NONE;
9199 s->we_are_in = FALSE;
9201 s->tried_pubkey_config = FALSE;
9202 s->kbd_inter_refused = FALSE;
9204 /* Reset agent request state. */
9205 s->done_agent = FALSE;
9206 if (s->agent_response) {
9207 if (s->pkblob_in_agent) {
9208 s->agentp = s->pkblob_in_agent;
9210 s->agentp = s->agent_response + 5 + 4;
9216 char *methods = NULL;
9220 * Wait for the result of the last authentication request.
9223 crWaitUntilV(pktin);
9225 * Now is a convenient point to spew any banner material
9226 * that we've accumulated. (This should ensure that when
9227 * we exit the auth loop, we haven't any left to deal
9231 int size = bufchain_size(&ssh->banner);
9233 * Don't show the banner if we're operating in
9234 * non-verbose non-interactive mode. (It's probably
9235 * a script, which means nobody will read the
9236 * banner _anyway_, and moreover the printing of
9237 * the banner will screw up processing on the
9238 * output of (say) plink.)
9240 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9241 char *banner = snewn(size, char);
9242 bufchain_fetch(&ssh->banner, banner, size);
9243 c_write_untrusted(ssh, banner, size);
9246 bufchain_clear(&ssh->banner);
9248 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9249 logevent("Access granted");
9250 s->we_are_in = s->userauth_success = TRUE;
9254 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9255 bombout(("Strange packet received during authentication: "
9256 "type %d", pktin->type));
9263 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9264 * we can look at the string in it and know what we can
9265 * helpfully try next.
9267 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9268 ssh_pkt_getstring(pktin, &methods, &methlen);
9269 if (!ssh2_pkt_getbool(pktin)) {
9271 * We have received an unequivocal Access
9272 * Denied. This can translate to a variety of
9273 * messages, or no message at all.
9275 * For forms of authentication which are attempted
9276 * implicitly, by which I mean without printing
9277 * anything in the window indicating that we're
9278 * trying them, we should never print 'Access
9281 * If we do print a message saying that we're
9282 * attempting some kind of authentication, it's OK
9283 * to print a followup message saying it failed -
9284 * but the message may sometimes be more specific
9285 * than simply 'Access denied'.
9287 * Additionally, if we'd just tried password
9288 * authentication, we should break out of this
9289 * whole loop so as to go back to the username
9290 * prompt (iff we're configured to allow
9291 * username change attempts).
9293 if (s->type == AUTH_TYPE_NONE) {
9295 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9296 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9297 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9298 c_write_str(ssh, "Server refused our key\r\n");
9299 logevent("Server refused our key");
9300 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9301 /* This _shouldn't_ happen except by a
9302 * protocol bug causing client and server to
9303 * disagree on what is a correct signature. */
9304 c_write_str(ssh, "Server refused public-key signature"
9305 " despite accepting key!\r\n");
9306 logevent("Server refused public-key signature"
9307 " despite accepting key!");
9308 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9309 /* quiet, so no c_write */
9310 logevent("Server refused keyboard-interactive authentication");
9311 } else if (s->type==AUTH_TYPE_GSSAPI) {
9312 /* always quiet, so no c_write */
9313 /* also, the code down in the GSSAPI block has
9314 * already logged this in the Event Log */
9315 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9316 logevent("Keyboard-interactive authentication failed");
9317 c_write_str(ssh, "Access denied\r\n");
9319 assert(s->type == AUTH_TYPE_PASSWORD);
9320 logevent("Password authentication failed");
9321 c_write_str(ssh, "Access denied\r\n");
9323 if (conf_get_int(ssh->conf, CONF_change_username)) {
9324 /* XXX perhaps we should allow
9325 * keyboard-interactive to do this too? */
9326 s->we_are_in = FALSE;
9331 c_write_str(ssh, "Further authentication required\r\n");
9332 logevent("Further authentication required");
9336 in_commasep_string("publickey", methods, methlen);
9338 in_commasep_string("password", methods, methlen);
9339 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9340 in_commasep_string("keyboard-interactive", methods, methlen);
9343 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9344 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9345 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9346 ssh->gsslibs->nlibraries > 0;
9350 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9352 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9355 * Attempt public-key authentication using a key from Pageant.
9358 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9360 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9362 /* Unpack key from agent response */
9363 s->pklen = toint(GET_32BIT(s->agentp));
9365 s->pkblob = (char *)s->agentp;
9366 s->agentp += s->pklen;
9367 s->alglen = toint(GET_32BIT(s->pkblob));
9368 s->alg = s->pkblob + 4;
9369 s->commentlen = toint(GET_32BIT(s->agentp));
9371 s->commentp = (char *)s->agentp;
9372 s->agentp += s->commentlen;
9373 /* s->agentp now points at next key, if any */
9375 /* See if server will accept it */
9376 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9377 ssh2_pkt_addstring(s->pktout, ssh->username);
9378 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9379 /* service requested */
9380 ssh2_pkt_addstring(s->pktout, "publickey");
9382 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9383 ssh2_pkt_addstring_start(s->pktout);
9384 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9385 ssh2_pkt_addstring_start(s->pktout);
9386 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9387 ssh2_pkt_send(ssh, s->pktout);
9388 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9390 crWaitUntilV(pktin);
9391 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9393 /* Offer of key refused. */
9400 if (flags & FLAG_VERBOSE) {
9401 c_write_str(ssh, "Authenticating with "
9403 c_write(ssh, s->commentp, s->commentlen);
9404 c_write_str(ssh, "\" from agent\r\n");
9408 * Server is willing to accept the key.
9409 * Construct a SIGN_REQUEST.
9411 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9412 ssh2_pkt_addstring(s->pktout, ssh->username);
9413 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9414 /* service requested */
9415 ssh2_pkt_addstring(s->pktout, "publickey");
9417 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9418 ssh2_pkt_addstring_start(s->pktout);
9419 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9420 ssh2_pkt_addstring_start(s->pktout);
9421 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9423 /* Ask agent for signature. */
9424 s->siglen = s->pktout->length - 5 + 4 +
9425 ssh->v2_session_id_len;
9426 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9428 s->len = 1; /* message type */
9429 s->len += 4 + s->pklen; /* key blob */
9430 s->len += 4 + s->siglen; /* data to sign */
9431 s->len += 4; /* flags */
9432 s->agentreq = snewn(4 + s->len, char);
9433 PUT_32BIT(s->agentreq, s->len);
9434 s->q = s->agentreq + 4;
9435 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9436 PUT_32BIT(s->q, s->pklen);
9438 memcpy(s->q, s->pkblob, s->pklen);
9440 PUT_32BIT(s->q, s->siglen);
9442 /* Now the data to be signed... */
9443 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9444 PUT_32BIT(s->q, ssh->v2_session_id_len);
9447 memcpy(s->q, ssh->v2_session_id,
9448 ssh->v2_session_id_len);
9449 s->q += ssh->v2_session_id_len;
9450 memcpy(s->q, s->pktout->data + 5,
9451 s->pktout->length - 5);
9452 s->q += s->pktout->length - 5;
9453 /* And finally the (zero) flags word. */
9455 if (!agent_query(s->agentreq, s->len + 4,
9457 ssh_agent_callback, ssh)) {
9461 bombout(("Unexpected data from server"
9462 " while waiting for agent"
9466 } while (pktin || inlen > 0);
9467 vret = ssh->agent_response;
9468 s->retlen = ssh->agent_response_len;
9473 if (s->retlen >= 9 &&
9474 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9475 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9476 logevent("Sending Pageant's response");
9477 ssh2_add_sigblob(ssh, s->pktout,
9478 s->pkblob, s->pklen,
9480 GET_32BIT(s->ret + 5));
9481 ssh2_pkt_send(ssh, s->pktout);
9482 s->type = AUTH_TYPE_PUBLICKEY;
9484 /* FIXME: less drastic response */
9485 bombout(("Pageant failed to answer challenge"));
9491 /* Do we have any keys left to try? */
9492 if (s->pkblob_in_agent) {
9493 s->done_agent = TRUE;
9494 s->tried_pubkey_config = TRUE;
9497 if (s->keyi >= s->nkeys)
9498 s->done_agent = TRUE;
9501 } else if (s->can_pubkey && s->publickey_blob &&
9502 s->privatekey_available && !s->tried_pubkey_config) {
9504 struct ssh2_userkey *key; /* not live over crReturn */
9505 char *passphrase; /* not live over crReturn */
9507 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9509 s->tried_pubkey_config = TRUE;
9512 * Try the public key supplied in the configuration.
9514 * First, offer the public blob to see if the server is
9515 * willing to accept it.
9517 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9518 ssh2_pkt_addstring(s->pktout, ssh->username);
9519 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9520 /* service requested */
9521 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9522 ssh2_pkt_addbool(s->pktout, FALSE);
9523 /* no signature included */
9524 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9525 ssh2_pkt_addstring_start(s->pktout);
9526 ssh2_pkt_addstring_data(s->pktout,
9527 (char *)s->publickey_blob,
9528 s->publickey_bloblen);
9529 ssh2_pkt_send(ssh, s->pktout);
9530 logevent("Offered public key");
9532 crWaitUntilV(pktin);
9533 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9534 /* Key refused. Give up. */
9535 s->gotit = TRUE; /* reconsider message next loop */
9536 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9537 continue; /* process this new message */
9539 logevent("Offer of public key accepted");
9542 * Actually attempt a serious authentication using
9545 if (flags & FLAG_VERBOSE) {
9546 c_write_str(ssh, "Authenticating with public key \"");
9547 c_write_str(ssh, s->publickey_comment);
9548 c_write_str(ssh, "\"\r\n");
9552 const char *error; /* not live over crReturn */
9553 if (s->privatekey_encrypted) {
9555 * Get a passphrase from the user.
9557 int ret; /* need not be kept over crReturn */
9558 s->cur_prompt = new_prompts(ssh->frontend);
9559 s->cur_prompt->to_server = FALSE;
9560 s->cur_prompt->name = dupstr("SSH key passphrase");
9561 add_prompt(s->cur_prompt,
9562 dupprintf("Passphrase for key \"%.100s\": ",
9563 s->publickey_comment),
9565 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9568 crWaitUntilV(!pktin);
9569 ret = get_userpass_input(s->cur_prompt,
9574 /* Failed to get a passphrase. Terminate. */
9575 free_prompts(s->cur_prompt);
9576 ssh_disconnect(ssh, NULL,
9577 "Unable to authenticate",
9578 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9583 dupstr(s->cur_prompt->prompts[0]->result);
9584 free_prompts(s->cur_prompt);
9586 passphrase = NULL; /* no passphrase needed */
9590 * Try decrypting the key.
9592 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9593 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9595 /* burn the evidence */
9596 smemclr(passphrase, strlen(passphrase));
9599 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9601 (key == SSH2_WRONG_PASSPHRASE)) {
9602 c_write_str(ssh, "Wrong passphrase\r\n");
9604 /* and loop again */
9606 c_write_str(ssh, "Unable to load private key (");
9607 c_write_str(ssh, error);
9608 c_write_str(ssh, ")\r\n");
9610 break; /* try something else */
9616 unsigned char *pkblob, *sigblob, *sigdata;
9617 int pkblob_len, sigblob_len, sigdata_len;
9621 * We have loaded the private key and the server
9622 * has announced that it's willing to accept it.
9623 * Hallelujah. Generate a signature and send it.
9625 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9626 ssh2_pkt_addstring(s->pktout, ssh->username);
9627 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9628 /* service requested */
9629 ssh2_pkt_addstring(s->pktout, "publickey");
9631 ssh2_pkt_addbool(s->pktout, TRUE);
9632 /* signature follows */
9633 ssh2_pkt_addstring(s->pktout, key->alg->name);
9634 pkblob = key->alg->public_blob(key->data,
9636 ssh2_pkt_addstring_start(s->pktout);
9637 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9641 * The data to be signed is:
9645 * followed by everything so far placed in the
9648 sigdata_len = s->pktout->length - 5 + 4 +
9649 ssh->v2_session_id_len;
9650 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9652 sigdata = snewn(sigdata_len, unsigned char);
9654 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9655 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9658 memcpy(sigdata+p, ssh->v2_session_id,
9659 ssh->v2_session_id_len);
9660 p += ssh->v2_session_id_len;
9661 memcpy(sigdata+p, s->pktout->data + 5,
9662 s->pktout->length - 5);
9663 p += s->pktout->length - 5;
9664 assert(p == sigdata_len);
9665 sigblob = key->alg->sign(key->data, (char *)sigdata,
9666 sigdata_len, &sigblob_len);
9667 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9668 sigblob, sigblob_len);
9673 ssh2_pkt_send(ssh, s->pktout);
9674 logevent("Sent public key signature");
9675 s->type = AUTH_TYPE_PUBLICKEY;
9676 key->alg->freekey(key->data);
9677 sfree(key->comment);
9682 } else if (s->can_gssapi && !s->tried_gssapi) {
9684 /* GSSAPI Authentication */
9689 s->type = AUTH_TYPE_GSSAPI;
9690 s->tried_gssapi = TRUE;
9692 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9695 * Pick the highest GSS library on the preference
9701 for (i = 0; i < ngsslibs; i++) {
9702 int want_id = conf_get_int_int(ssh->conf,
9703 CONF_ssh_gsslist, i);
9704 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9705 if (ssh->gsslibs->libraries[j].id == want_id) {
9706 s->gsslib = &ssh->gsslibs->libraries[j];
9707 goto got_gsslib; /* double break */
9712 * We always expect to have found something in
9713 * the above loop: we only came here if there
9714 * was at least one viable GSS library, and the
9715 * preference list should always mention
9716 * everything and only change the order.
9721 if (s->gsslib->gsslogmsg)
9722 logevent(s->gsslib->gsslogmsg);
9724 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9725 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9726 ssh2_pkt_addstring(s->pktout, ssh->username);
9727 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9728 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9729 logevent("Attempting GSSAPI authentication");
9731 /* add mechanism info */
9732 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9734 /* number of GSSAPI mechanisms */
9735 ssh2_pkt_adduint32(s->pktout,1);
9737 /* length of OID + 2 */
9738 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9739 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9742 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9744 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9746 ssh2_pkt_send(ssh, s->pktout);
9747 crWaitUntilV(pktin);
9748 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9749 logevent("GSSAPI authentication request refused");
9753 /* check returned packet ... */
9755 ssh_pkt_getstring(pktin, &data, &len);
9756 s->gss_rcvtok.value = data;
9757 s->gss_rcvtok.length = len;
9758 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9759 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9760 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9761 memcmp((char *)s->gss_rcvtok.value + 2,
9762 s->gss_buf.value,s->gss_buf.length) ) {
9763 logevent("GSSAPI authentication - wrong response from server");
9767 /* now start running */
9768 s->gss_stat = s->gsslib->import_name(s->gsslib,
9771 if (s->gss_stat != SSH_GSS_OK) {
9772 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9773 logevent("GSSAPI import name failed - Bad service name");
9775 logevent("GSSAPI import name failed");
9779 /* fetch TGT into GSS engine */
9780 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9782 if (s->gss_stat != SSH_GSS_OK) {
9783 logevent("GSSAPI authentication failed to get credentials");
9784 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9788 /* initial tokens are empty */
9789 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9790 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9792 /* now enter the loop */
9794 s->gss_stat = s->gsslib->init_sec_context
9798 conf_get_int(ssh->conf, CONF_gssapifwd),
9802 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9803 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9804 logevent("GSSAPI authentication initialisation failed");
9806 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9807 &s->gss_buf) == SSH_GSS_OK) {
9808 logevent(s->gss_buf.value);
9809 sfree(s->gss_buf.value);
9814 logevent("GSSAPI authentication initialised");
9816 /* Client and server now exchange tokens until GSSAPI
9817 * no longer says CONTINUE_NEEDED */
9819 if (s->gss_sndtok.length != 0) {
9820 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9821 ssh_pkt_addstring_start(s->pktout);
9822 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9823 ssh2_pkt_send(ssh, s->pktout);
9824 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9827 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9828 crWaitUntilV(pktin);
9829 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9830 logevent("GSSAPI authentication - bad server response");
9831 s->gss_stat = SSH_GSS_FAILURE;
9834 ssh_pkt_getstring(pktin, &data, &len);
9835 s->gss_rcvtok.value = data;
9836 s->gss_rcvtok.length = len;
9838 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9840 if (s->gss_stat != SSH_GSS_OK) {
9841 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9842 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9845 logevent("GSSAPI authentication loop finished OK");
9847 /* Now send the MIC */
9849 s->pktout = ssh2_pkt_init(0);
9850 micoffset = s->pktout->length;
9851 ssh_pkt_addstring_start(s->pktout);
9852 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9853 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9854 ssh_pkt_addstring(s->pktout, ssh->username);
9855 ssh_pkt_addstring(s->pktout, "ssh-connection");
9856 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9858 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9859 s->gss_buf.length = s->pktout->length - micoffset;
9861 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9862 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9863 ssh_pkt_addstring_start(s->pktout);
9864 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9865 ssh2_pkt_send(ssh, s->pktout);
9866 s->gsslib->free_mic(s->gsslib, &mic);
9870 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9871 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9874 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9877 * Keyboard-interactive authentication.
9880 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9882 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9884 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9885 ssh2_pkt_addstring(s->pktout, ssh->username);
9886 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9887 /* service requested */
9888 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9890 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9891 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9892 ssh2_pkt_send(ssh, s->pktout);
9894 logevent("Attempting keyboard-interactive authentication");
9896 crWaitUntilV(pktin);
9897 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9898 /* Server is not willing to do keyboard-interactive
9899 * at all (or, bizarrely but legally, accepts the
9900 * user without actually issuing any prompts).
9901 * Give up on it entirely. */
9903 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9904 s->kbd_inter_refused = TRUE; /* don't try it again */
9909 * Loop while the server continues to send INFO_REQUESTs.
9911 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9913 char *name, *inst, *lang;
9914 int name_len, inst_len, lang_len;
9918 * We've got a fresh USERAUTH_INFO_REQUEST.
9919 * Get the preamble and start building a prompt.
9921 ssh_pkt_getstring(pktin, &name, &name_len);
9922 ssh_pkt_getstring(pktin, &inst, &inst_len);
9923 ssh_pkt_getstring(pktin, &lang, &lang_len);
9924 s->cur_prompt = new_prompts(ssh->frontend);
9925 s->cur_prompt->to_server = TRUE;
9928 * Get any prompt(s) from the packet.
9930 s->num_prompts = ssh_pkt_getuint32(pktin);
9931 for (i = 0; i < s->num_prompts; i++) {
9935 static char noprompt[] =
9936 "<server failed to send prompt>: ";
9938 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9939 echo = ssh2_pkt_getbool(pktin);
9942 prompt_len = lenof(noprompt)-1;
9944 add_prompt(s->cur_prompt,
9945 dupprintf("%.*s", prompt_len, prompt),
9950 /* FIXME: better prefix to distinguish from
9952 s->cur_prompt->name =
9953 dupprintf("SSH server: %.*s", name_len, name);
9954 s->cur_prompt->name_reqd = TRUE;
9956 s->cur_prompt->name =
9957 dupstr("SSH server authentication");
9958 s->cur_prompt->name_reqd = FALSE;
9960 /* We add a prefix to try to make it clear that a prompt
9961 * has come from the server.
9962 * FIXME: ugly to print "Using..." in prompt _every_
9963 * time round. Can this be done more subtly? */
9964 /* Special case: for reasons best known to themselves,
9965 * some servers send k-i requests with no prompts and
9966 * nothing to display. Keep quiet in this case. */
9967 if (s->num_prompts || name_len || inst_len) {
9968 s->cur_prompt->instruction =
9969 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9970 inst_len ? "\n" : "", inst_len, inst);
9971 s->cur_prompt->instr_reqd = TRUE;
9973 s->cur_prompt->instr_reqd = FALSE;
9977 * Display any instructions, and get the user's
9981 int ret; /* not live over crReturn */
9982 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9985 crWaitUntilV(!pktin);
9986 ret = get_userpass_input(s->cur_prompt, in, inlen);
9991 * Failed to get responses. Terminate.
9993 free_prompts(s->cur_prompt);
9994 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9995 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10002 * Send the response(s) to the server.
10004 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10005 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10006 for (i=0; i < s->num_prompts; i++) {
10007 ssh2_pkt_addstring(s->pktout,
10008 s->cur_prompt->prompts[i]->result);
10010 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10013 * Free the prompts structure from this iteration.
10014 * If there's another, a new one will be allocated
10015 * when we return to the top of this while loop.
10017 free_prompts(s->cur_prompt);
10020 * Get the next packet in case it's another
10023 crWaitUntilV(pktin);
10028 * We should have SUCCESS or FAILURE now.
10032 } else if (s->can_passwd) {
10035 * Plain old password authentication.
10037 int ret; /* not live over crReturn */
10038 int changereq_first_time; /* not live over crReturn */
10040 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10042 s->cur_prompt = new_prompts(ssh->frontend);
10043 s->cur_prompt->to_server = TRUE;
10044 s->cur_prompt->name = dupstr("SSH password");
10045 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10050 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10053 crWaitUntilV(!pktin);
10054 ret = get_userpass_input(s->cur_prompt, in, inlen);
10059 * Failed to get responses. Terminate.
10061 free_prompts(s->cur_prompt);
10062 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10063 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10068 * Squirrel away the password. (We may need it later if
10069 * asked to change it.)
10071 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10072 free_prompts(s->cur_prompt);
10075 * Send the password packet.
10077 * We pad out the password packet to 256 bytes to make
10078 * it harder for an attacker to find the length of the
10081 * Anyone using a password longer than 256 bytes
10082 * probably doesn't have much to worry about from
10083 * people who find out how long their password is!
10085 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10086 ssh2_pkt_addstring(s->pktout, ssh->username);
10087 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10088 /* service requested */
10089 ssh2_pkt_addstring(s->pktout, "password");
10090 ssh2_pkt_addbool(s->pktout, FALSE);
10091 ssh2_pkt_addstring(s->pktout, s->password);
10092 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10093 logevent("Sent password");
10094 s->type = AUTH_TYPE_PASSWORD;
10097 * Wait for next packet, in case it's a password change
10100 crWaitUntilV(pktin);
10101 changereq_first_time = TRUE;
10103 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10106 * We're being asked for a new password
10107 * (perhaps not for the first time).
10108 * Loop until the server accepts it.
10111 int got_new = FALSE; /* not live over crReturn */
10112 char *prompt; /* not live over crReturn */
10113 int prompt_len; /* not live over crReturn */
10117 if (changereq_first_time)
10118 msg = "Server requested password change";
10120 msg = "Server rejected new password";
10122 c_write_str(ssh, msg);
10123 c_write_str(ssh, "\r\n");
10126 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10128 s->cur_prompt = new_prompts(ssh->frontend);
10129 s->cur_prompt->to_server = TRUE;
10130 s->cur_prompt->name = dupstr("New SSH password");
10131 s->cur_prompt->instruction =
10132 dupprintf("%.*s", prompt_len, prompt);
10133 s->cur_prompt->instr_reqd = TRUE;
10135 * There's no explicit requirement in the protocol
10136 * for the "old" passwords in the original and
10137 * password-change messages to be the same, and
10138 * apparently some Cisco kit supports password change
10139 * by the user entering a blank password originally
10140 * and the real password subsequently, so,
10141 * reluctantly, we prompt for the old password again.
10143 * (On the other hand, some servers don't even bother
10144 * to check this field.)
10146 add_prompt(s->cur_prompt,
10147 dupstr("Current password (blank for previously entered password): "),
10149 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10151 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10155 * Loop until the user manages to enter the same
10160 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10163 crWaitUntilV(!pktin);
10164 ret = get_userpass_input(s->cur_prompt, in, inlen);
10169 * Failed to get responses. Terminate.
10171 /* burn the evidence */
10172 free_prompts(s->cur_prompt);
10173 smemclr(s->password, strlen(s->password));
10174 sfree(s->password);
10175 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10176 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10182 * If the user specified a new original password
10183 * (IYSWIM), overwrite any previously specified
10185 * (A side effect is that the user doesn't have to
10186 * re-enter it if they louse up the new password.)
10188 if (s->cur_prompt->prompts[0]->result[0]) {
10189 smemclr(s->password, strlen(s->password));
10190 /* burn the evidence */
10191 sfree(s->password);
10193 dupstr(s->cur_prompt->prompts[0]->result);
10197 * Check the two new passwords match.
10199 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10200 s->cur_prompt->prompts[2]->result)
10203 /* They don't. Silly user. */
10204 c_write_str(ssh, "Passwords do not match\r\n");
10209 * Send the new password (along with the old one).
10210 * (see above for padding rationale)
10212 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10213 ssh2_pkt_addstring(s->pktout, ssh->username);
10214 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10215 /* service requested */
10216 ssh2_pkt_addstring(s->pktout, "password");
10217 ssh2_pkt_addbool(s->pktout, TRUE);
10218 ssh2_pkt_addstring(s->pktout, s->password);
10219 ssh2_pkt_addstring(s->pktout,
10220 s->cur_prompt->prompts[1]->result);
10221 free_prompts(s->cur_prompt);
10222 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10223 logevent("Sent new password");
10226 * Now see what the server has to say about it.
10227 * (If it's CHANGEREQ again, it's not happy with the
10230 crWaitUntilV(pktin);
10231 changereq_first_time = FALSE;
10236 * We need to reexamine the current pktin at the top
10237 * of the loop. Either:
10238 * - we weren't asked to change password at all, in
10239 * which case it's a SUCCESS or FAILURE with the
10241 * - we sent a new password, and the server was
10242 * either OK with it (SUCCESS or FAILURE w/partial
10243 * success) or unhappy with the _old_ password
10244 * (FAILURE w/o partial success)
10245 * In any of these cases, we go back to the top of
10246 * the loop and start again.
10251 * We don't need the old password any more, in any
10252 * case. Burn the evidence.
10254 smemclr(s->password, strlen(s->password));
10255 sfree(s->password);
10258 char *str = dupprintf("No supported authentication methods available"
10259 " (server sent: %.*s)",
10262 ssh_disconnect(ssh, str,
10263 "No supported authentication methods available",
10264 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10274 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10276 /* Clear up various bits and pieces from authentication. */
10277 if (s->publickey_blob) {
10278 sfree(s->publickey_blob);
10279 sfree(s->publickey_comment);
10281 if (s->agent_response)
10282 sfree(s->agent_response);
10284 if (s->userauth_success && !ssh->bare_connection) {
10286 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10287 * packets since. Signal the transport layer to consider enacting
10288 * delayed compression.
10290 * (Relying on we_are_in is not sufficient, as
10291 * draft-miller-secsh-compression-delayed is quite clear that it
10292 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10293 * become set for other reasons.)
10295 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10298 ssh->channels = newtree234(ssh_channelcmp);
10301 * Set up handlers for some connection protocol messages, so we
10302 * don't have to handle them repeatedly in this coroutine.
10304 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10305 ssh2_msg_channel_window_adjust;
10306 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10307 ssh2_msg_global_request;
10310 * Create the main session channel.
10312 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10313 ssh->mainchan = NULL;
10315 ssh->mainchan = snew(struct ssh_channel);
10316 ssh->mainchan->ssh = ssh;
10317 ssh2_channel_init(ssh->mainchan);
10319 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10321 * Just start a direct-tcpip channel and use it as the main
10324 ssh_send_port_open(ssh->mainchan,
10325 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10326 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10328 ssh->ncmode = TRUE;
10330 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10331 logevent("Opening session as main channel");
10332 ssh2_pkt_send(ssh, s->pktout);
10333 ssh->ncmode = FALSE;
10335 crWaitUntilV(pktin);
10336 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10337 bombout(("Server refused to open channel"));
10339 /* FIXME: error data comes back in FAILURE packet */
10341 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10342 bombout(("Server's channel confirmation cited wrong channel"));
10345 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10346 ssh->mainchan->halfopen = FALSE;
10347 ssh->mainchan->type = CHAN_MAINSESSION;
10348 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10349 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10350 add234(ssh->channels, ssh->mainchan);
10351 update_specials_menu(ssh->frontend);
10352 logevent("Opened main channel");
10356 * Now we have a channel, make dispatch table entries for
10357 * general channel-based messages.
10359 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10360 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10361 ssh2_msg_channel_data;
10362 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10363 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10364 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10365 ssh2_msg_channel_open_confirmation;
10366 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10367 ssh2_msg_channel_open_failure;
10368 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10369 ssh2_msg_channel_request;
10370 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10371 ssh2_msg_channel_open;
10372 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10373 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10376 * Now the connection protocol is properly up and running, with
10377 * all those dispatch table entries, so it's safe to let
10378 * downstreams start trying to open extra channels through us.
10380 if (ssh->connshare)
10381 share_activate(ssh->connshare, ssh->v_s);
10383 if (ssh->mainchan && ssh_is_simple(ssh)) {
10385 * This message indicates to the server that we promise
10386 * not to try to run any other channel in parallel with
10387 * this one, so it's safe for it to advertise a very large
10388 * window and leave the flow control to TCP.
10390 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10391 "simple@putty.projects.tartarus.org",
10393 ssh2_pkt_send(ssh, s->pktout);
10397 * Enable port forwardings.
10399 ssh_setup_portfwd(ssh, ssh->conf);
10401 if (ssh->mainchan && !ssh->ncmode) {
10403 * Send the CHANNEL_REQUESTS for the main session channel.
10404 * Each one is handled by its own little asynchronous
10408 /* Potentially enable X11 forwarding. */
10409 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10411 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10413 if (!ssh->x11disp) {
10414 /* FIXME: return an error message from x11_setup_display */
10415 logevent("X11 forwarding not enabled: unable to"
10416 " initialise X display");
10418 ssh->x11auth = x11_invent_fake_auth
10419 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10420 ssh->x11auth->disp = ssh->x11disp;
10422 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10426 /* Potentially enable agent forwarding. */
10427 if (ssh_agent_forwarding_permitted(ssh))
10428 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10430 /* Now allocate a pty for the session. */
10431 if (!conf_get_int(ssh->conf, CONF_nopty))
10432 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10434 /* Send environment variables. */
10435 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10438 * Start a shell or a remote command. We may have to attempt
10439 * this twice if the config data has provided a second choice
10446 if (ssh->fallback_cmd) {
10447 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10448 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10450 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10451 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10455 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10456 ssh2_response_authconn, NULL);
10457 ssh2_pkt_addstring(s->pktout, cmd);
10459 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10460 ssh2_response_authconn, NULL);
10461 ssh2_pkt_addstring(s->pktout, cmd);
10463 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10464 ssh2_response_authconn, NULL);
10466 ssh2_pkt_send(ssh, s->pktout);
10468 crWaitUntilV(pktin);
10470 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10471 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10472 bombout(("Unexpected response to shell/command request:"
10473 " packet type %d", pktin->type));
10477 * We failed to start the command. If this is the
10478 * fallback command, we really are finished; if it's
10479 * not, and if the fallback command exists, try falling
10480 * back to it before complaining.
10482 if (!ssh->fallback_cmd &&
10483 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10484 logevent("Primary command failed; attempting fallback");
10485 ssh->fallback_cmd = TRUE;
10488 bombout(("Server refused to start a shell/command"));
10491 logevent("Started a shell/command");
10496 ssh->editing = ssh->echoing = TRUE;
10499 ssh->state = SSH_STATE_SESSION;
10500 if (ssh->size_needed)
10501 ssh_size(ssh, ssh->term_width, ssh->term_height);
10502 if (ssh->eof_needed)
10503 ssh_special(ssh, TS_EOF);
10509 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10514 s->try_send = FALSE;
10518 * _All_ the connection-layer packets we expect to
10519 * receive are now handled by the dispatch table.
10520 * Anything that reaches here must be bogus.
10523 bombout(("Strange packet received: type %d", pktin->type));
10525 } else if (ssh->mainchan) {
10527 * We have spare data. Add it to the channel buffer.
10529 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10530 s->try_send = TRUE;
10534 struct ssh_channel *c;
10536 * Try to send data on all channels if we can.
10538 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10539 ssh2_try_send_and_unthrottle(ssh, c);
10547 * Handlers for SSH-2 messages that might arrive at any moment.
10549 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10551 /* log reason code in disconnect message */
10553 int reason, msglen;
10555 reason = ssh_pkt_getuint32(pktin);
10556 ssh_pkt_getstring(pktin, &msg, &msglen);
10558 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10559 buf = dupprintf("Received disconnect message (%s)",
10560 ssh2_disconnect_reasons[reason]);
10562 buf = dupprintf("Received disconnect message (unknown"
10563 " type %d)", reason);
10567 buf = dupprintf("Disconnection message text: %.*s",
10570 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10572 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10573 ssh2_disconnect_reasons[reason] : "unknown",
10578 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10580 /* log the debug message */
10584 /* XXX maybe we should actually take notice of the return value */
10585 ssh2_pkt_getbool(pktin);
10586 ssh_pkt_getstring(pktin, &msg, &msglen);
10588 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10591 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10593 do_ssh2_transport(ssh, NULL, 0, pktin);
10597 * Called if we receive a packet that isn't allowed by the protocol.
10598 * This only applies to packets whose meaning PuTTY understands.
10599 * Entirely unknown packets are handled below.
10601 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10603 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10604 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10606 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10610 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10612 struct Packet *pktout;
10613 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10614 ssh2_pkt_adduint32(pktout, pktin->sequence);
10616 * UNIMPLEMENTED messages MUST appear in the same order as the
10617 * messages they respond to. Hence, never queue them.
10619 ssh2_pkt_send_noqueue(ssh, pktout);
10623 * Handle the top-level SSH-2 protocol.
10625 static void ssh2_protocol_setup(Ssh ssh)
10630 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10632 for (i = 0; i < 256; i++)
10633 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10636 * Initially, we only accept transport messages (and a few generic
10637 * ones). do_ssh2_authconn will add more when it starts.
10638 * Messages that are understood but not currently acceptable go to
10639 * ssh2_msg_unexpected.
10641 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10642 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10643 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10644 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10645 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10646 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10647 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10648 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10649 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10650 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10651 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10652 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10653 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10654 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10655 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10656 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10657 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10658 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10659 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10660 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10661 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10662 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10663 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10664 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10665 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10666 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10667 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10668 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10669 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10670 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10671 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10672 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10673 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10676 * These messages have a special handler from the start.
10678 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10679 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10680 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10683 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10688 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10690 for (i = 0; i < 256; i++)
10691 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10694 * Initially, we set all ssh-connection messages to 'unexpected';
10695 * do_ssh2_authconn will fill things in properly. We also handle a
10696 * couple of messages from the transport protocol which aren't
10697 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10700 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10701 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10702 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10703 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10704 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10705 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10706 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10707 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10708 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10709 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10710 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10711 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10712 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10713 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10715 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10718 * These messages have a special handler from the start.
10720 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10721 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10722 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10725 static void ssh2_timer(void *ctx, unsigned long now)
10727 Ssh ssh = (Ssh)ctx;
10729 if (ssh->state == SSH_STATE_CLOSED)
10732 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10733 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10734 now == ssh->next_rekey) {
10735 do_ssh2_transport(ssh, "timeout", -1, NULL);
10739 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10740 struct Packet *pktin)
10742 unsigned char *in = (unsigned char *)vin;
10743 if (ssh->state == SSH_STATE_CLOSED)
10747 ssh->incoming_data_size += pktin->encrypted_len;
10748 if (!ssh->kex_in_progress &&
10749 ssh->max_data_size != 0 &&
10750 ssh->incoming_data_size > ssh->max_data_size)
10751 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10755 ssh->packet_dispatch[pktin->type](ssh, pktin);
10756 else if (!ssh->protocol_initial_phase_done)
10757 do_ssh2_transport(ssh, in, inlen, pktin);
10759 do_ssh2_authconn(ssh, in, inlen, pktin);
10762 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10763 struct Packet *pktin)
10765 unsigned char *in = (unsigned char *)vin;
10766 if (ssh->state == SSH_STATE_CLOSED)
10770 ssh->packet_dispatch[pktin->type](ssh, pktin);
10772 do_ssh2_authconn(ssh, in, inlen, pktin);
10775 static void ssh_cache_conf_values(Ssh ssh)
10777 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10781 * Called to set up the connection.
10783 * Returns an error message, or NULL on success.
10785 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10786 Conf *conf, char *host, int port, char **realhost,
10787 int nodelay, int keepalive)
10792 ssh = snew(struct ssh_tag);
10793 ssh->conf = conf_copy(conf);
10794 ssh_cache_conf_values(ssh);
10795 ssh->version = 0; /* when not ready yet */
10797 ssh->cipher = NULL;
10798 ssh->v1_cipher_ctx = NULL;
10799 ssh->crcda_ctx = NULL;
10800 ssh->cscipher = NULL;
10801 ssh->cs_cipher_ctx = NULL;
10802 ssh->sccipher = NULL;
10803 ssh->sc_cipher_ctx = NULL;
10805 ssh->cs_mac_ctx = NULL;
10807 ssh->sc_mac_ctx = NULL;
10808 ssh->cscomp = NULL;
10809 ssh->cs_comp_ctx = NULL;
10810 ssh->sccomp = NULL;
10811 ssh->sc_comp_ctx = NULL;
10813 ssh->kex_ctx = NULL;
10814 ssh->hostkey = NULL;
10815 ssh->hostkey_str = NULL;
10816 ssh->exitcode = -1;
10817 ssh->close_expected = FALSE;
10818 ssh->clean_exit = FALSE;
10819 ssh->state = SSH_STATE_PREPACKET;
10820 ssh->size_needed = FALSE;
10821 ssh->eof_needed = FALSE;
10823 ssh->logctx = NULL;
10824 ssh->deferred_send_data = NULL;
10825 ssh->deferred_len = 0;
10826 ssh->deferred_size = 0;
10827 ssh->fallback_cmd = 0;
10828 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10829 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10830 ssh->x11disp = NULL;
10831 ssh->x11auth = NULL;
10832 ssh->x11authtree = newtree234(x11_authcmp);
10833 ssh->v1_compressing = FALSE;
10834 ssh->v2_outgoing_sequence = 0;
10835 ssh->ssh1_rdpkt_crstate = 0;
10836 ssh->ssh2_rdpkt_crstate = 0;
10837 ssh->ssh2_bare_rdpkt_crstate = 0;
10838 ssh->ssh_gotdata_crstate = 0;
10839 ssh->do_ssh1_connection_crstate = 0;
10840 ssh->do_ssh_init_state = NULL;
10841 ssh->do_ssh_connection_init_state = NULL;
10842 ssh->do_ssh1_login_state = NULL;
10843 ssh->do_ssh2_transport_state = NULL;
10844 ssh->do_ssh2_authconn_state = NULL;
10847 ssh->mainchan = NULL;
10848 ssh->throttled_all = 0;
10849 ssh->v1_stdout_throttling = 0;
10851 ssh->queuelen = ssh->queuesize = 0;
10852 ssh->queueing = FALSE;
10853 ssh->qhead = ssh->qtail = NULL;
10854 ssh->deferred_rekey_reason = NULL;
10855 bufchain_init(&ssh->queued_incoming_data);
10856 ssh->frozen = FALSE;
10857 ssh->username = NULL;
10858 ssh->sent_console_eof = FALSE;
10859 ssh->got_pty = FALSE;
10860 ssh->bare_connection = FALSE;
10861 ssh->X11_fwd_enabled = FALSE;
10862 ssh->connshare = NULL;
10863 ssh->attempting_connshare = FALSE;
10865 *backend_handle = ssh;
10868 if (crypto_startup() == 0)
10869 return "Microsoft high encryption pack not installed!";
10872 ssh->frontend = frontend_handle;
10873 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10874 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10876 ssh->channels = NULL;
10877 ssh->rportfwds = NULL;
10878 ssh->portfwds = NULL;
10883 ssh->conn_throttle_count = 0;
10884 ssh->overall_bufsize = 0;
10885 ssh->fallback_cmd = 0;
10887 ssh->protocol = NULL;
10889 ssh->protocol_initial_phase_done = FALSE;
10891 ssh->pinger = NULL;
10893 ssh->incoming_data_size = ssh->outgoing_data_size =
10894 ssh->deferred_data_size = 0L;
10895 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10896 CONF_ssh_rekey_data));
10897 ssh->kex_in_progress = FALSE;
10900 ssh->gsslibs = NULL;
10903 random_ref(); /* do this now - may be needed by sharing setup code */
10905 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10914 static void ssh_free(void *handle)
10916 Ssh ssh = (Ssh) handle;
10917 struct ssh_channel *c;
10918 struct ssh_rportfwd *pf;
10919 struct X11FakeAuth *auth;
10921 if (ssh->v1_cipher_ctx)
10922 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10923 if (ssh->cs_cipher_ctx)
10924 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10925 if (ssh->sc_cipher_ctx)
10926 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10927 if (ssh->cs_mac_ctx)
10928 ssh->csmac->free_context(ssh->cs_mac_ctx);
10929 if (ssh->sc_mac_ctx)
10930 ssh->scmac->free_context(ssh->sc_mac_ctx);
10931 if (ssh->cs_comp_ctx) {
10933 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10935 zlib_compress_cleanup(ssh->cs_comp_ctx);
10937 if (ssh->sc_comp_ctx) {
10939 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10941 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10944 dh_cleanup(ssh->kex_ctx);
10945 sfree(ssh->savedhost);
10947 while (ssh->queuelen-- > 0)
10948 ssh_free_packet(ssh->queue[ssh->queuelen]);
10951 while (ssh->qhead) {
10952 struct queued_handler *qh = ssh->qhead;
10953 ssh->qhead = qh->next;
10956 ssh->qhead = ssh->qtail = NULL;
10958 if (ssh->channels) {
10959 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10962 if (c->u.x11.xconn != NULL)
10963 x11_close(c->u.x11.xconn);
10965 case CHAN_SOCKDATA:
10966 case CHAN_SOCKDATA_DORMANT:
10967 if (c->u.pfd.pf != NULL)
10968 pfd_close(c->u.pfd.pf);
10971 if (ssh->version == 2) {
10972 struct outstanding_channel_request *ocr, *nocr;
10973 ocr = c->v.v2.chanreq_head;
10975 ocr->handler(c, NULL, ocr->ctx);
10980 bufchain_clear(&c->v.v2.outbuffer);
10984 freetree234(ssh->channels);
10985 ssh->channels = NULL;
10988 if (ssh->connshare)
10989 sharestate_free(ssh->connshare);
10991 if (ssh->rportfwds) {
10992 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10994 freetree234(ssh->rportfwds);
10995 ssh->rportfwds = NULL;
10997 sfree(ssh->deferred_send_data);
10999 x11_free_display(ssh->x11disp);
11000 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11001 x11_free_fake_auth(auth);
11002 freetree234(ssh->x11authtree);
11003 sfree(ssh->do_ssh_init_state);
11004 sfree(ssh->do_ssh1_login_state);
11005 sfree(ssh->do_ssh2_transport_state);
11006 sfree(ssh->do_ssh2_authconn_state);
11009 sfree(ssh->fullhostname);
11010 sfree(ssh->hostkey_str);
11011 if (ssh->crcda_ctx) {
11012 crcda_free_context(ssh->crcda_ctx);
11013 ssh->crcda_ctx = NULL;
11016 ssh_do_close(ssh, TRUE);
11017 expire_timer_context(ssh);
11019 pinger_free(ssh->pinger);
11020 bufchain_clear(&ssh->queued_incoming_data);
11021 sfree(ssh->username);
11022 conf_free(ssh->conf);
11025 ssh_gss_cleanup(ssh->gsslibs);
11033 * Reconfigure the SSH backend.
11035 static void ssh_reconfig(void *handle, Conf *conf)
11037 Ssh ssh = (Ssh) handle;
11038 char *rekeying = NULL, rekey_mandatory = FALSE;
11039 unsigned long old_max_data_size;
11042 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11044 ssh_setup_portfwd(ssh, conf);
11046 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11047 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11049 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11050 unsigned long now = GETTICKCOUNT();
11052 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11053 rekeying = "timeout shortened";
11055 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11059 old_max_data_size = ssh->max_data_size;
11060 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11061 CONF_ssh_rekey_data));
11062 if (old_max_data_size != ssh->max_data_size &&
11063 ssh->max_data_size != 0) {
11064 if (ssh->outgoing_data_size > ssh->max_data_size ||
11065 ssh->incoming_data_size > ssh->max_data_size)
11066 rekeying = "data limit lowered";
11069 if (conf_get_int(ssh->conf, CONF_compression) !=
11070 conf_get_int(conf, CONF_compression)) {
11071 rekeying = "compression setting changed";
11072 rekey_mandatory = TRUE;
11075 for (i = 0; i < CIPHER_MAX; i++)
11076 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11077 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11078 rekeying = "cipher settings changed";
11079 rekey_mandatory = TRUE;
11081 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11082 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11083 rekeying = "cipher settings changed";
11084 rekey_mandatory = TRUE;
11087 conf_free(ssh->conf);
11088 ssh->conf = conf_copy(conf);
11089 ssh_cache_conf_values(ssh);
11091 if (!ssh->bare_connection && rekeying) {
11092 if (!ssh->kex_in_progress) {
11093 do_ssh2_transport(ssh, rekeying, -1, NULL);
11094 } else if (rekey_mandatory) {
11095 ssh->deferred_rekey_reason = rekeying;
11101 * Called to send data down the SSH connection.
11103 static int ssh_send(void *handle, char *buf, int len)
11105 Ssh ssh = (Ssh) handle;
11107 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11110 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
11112 return ssh_sendbuffer(ssh);
11116 * Called to query the current amount of buffered stdin data.
11118 static int ssh_sendbuffer(void *handle)
11120 Ssh ssh = (Ssh) handle;
11121 int override_value;
11123 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11127 * If the SSH socket itself has backed up, add the total backup
11128 * size on that to any individual buffer on the stdin channel.
11130 override_value = 0;
11131 if (ssh->throttled_all)
11132 override_value = ssh->overall_bufsize;
11134 if (ssh->version == 1) {
11135 return override_value;
11136 } else if (ssh->version == 2) {
11137 if (!ssh->mainchan)
11138 return override_value;
11140 return (override_value +
11141 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11148 * Called to set the size of the window from SSH's POV.
11150 static void ssh_size(void *handle, int width, int height)
11152 Ssh ssh = (Ssh) handle;
11153 struct Packet *pktout;
11155 ssh->term_width = width;
11156 ssh->term_height = height;
11158 switch (ssh->state) {
11159 case SSH_STATE_BEFORE_SIZE:
11160 case SSH_STATE_PREPACKET:
11161 case SSH_STATE_CLOSED:
11162 break; /* do nothing */
11163 case SSH_STATE_INTERMED:
11164 ssh->size_needed = TRUE; /* buffer for later */
11166 case SSH_STATE_SESSION:
11167 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11168 if (ssh->version == 1) {
11169 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11170 PKT_INT, ssh->term_height,
11171 PKT_INT, ssh->term_width,
11172 PKT_INT, 0, PKT_INT, 0, PKT_END);
11173 } else if (ssh->mainchan) {
11174 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11176 ssh2_pkt_adduint32(pktout, ssh->term_width);
11177 ssh2_pkt_adduint32(pktout, ssh->term_height);
11178 ssh2_pkt_adduint32(pktout, 0);
11179 ssh2_pkt_adduint32(pktout, 0);
11180 ssh2_pkt_send(ssh, pktout);
11188 * Return a list of the special codes that make sense in this
11191 static const struct telnet_special *ssh_get_specials(void *handle)
11193 static const struct telnet_special ssh1_ignore_special[] = {
11194 {"IGNORE message", TS_NOP}
11196 static const struct telnet_special ssh2_ignore_special[] = {
11197 {"IGNORE message", TS_NOP},
11199 static const struct telnet_special ssh2_rekey_special[] = {
11200 {"Repeat key exchange", TS_REKEY},
11202 static const struct telnet_special ssh2_session_specials[] = {
11205 /* These are the signal names defined by RFC 4254.
11206 * They include all the ISO C signals, but are a subset of the POSIX
11207 * required signals. */
11208 {"SIGINT (Interrupt)", TS_SIGINT},
11209 {"SIGTERM (Terminate)", TS_SIGTERM},
11210 {"SIGKILL (Kill)", TS_SIGKILL},
11211 {"SIGQUIT (Quit)", TS_SIGQUIT},
11212 {"SIGHUP (Hangup)", TS_SIGHUP},
11213 {"More signals", TS_SUBMENU},
11214 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11215 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11216 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11217 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11218 {NULL, TS_EXITMENU}
11220 static const struct telnet_special specials_end[] = {
11221 {NULL, TS_EXITMENU}
11223 /* XXX review this length for any changes: */
11224 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
11225 lenof(ssh2_rekey_special) +
11226 lenof(ssh2_session_specials) +
11227 lenof(specials_end)];
11228 Ssh ssh = (Ssh) handle;
11230 #define ADD_SPECIALS(name) \
11232 assert((i + lenof(name)) <= lenof(ssh_specials)); \
11233 memcpy(&ssh_specials[i], name, sizeof name); \
11234 i += lenof(name); \
11237 if (ssh->version == 1) {
11238 /* Don't bother offering IGNORE if we've decided the remote
11239 * won't cope with it, since we wouldn't bother sending it if
11241 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11242 ADD_SPECIALS(ssh1_ignore_special);
11243 } else if (ssh->version == 2) {
11244 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11245 ADD_SPECIALS(ssh2_ignore_special);
11246 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11247 ADD_SPECIALS(ssh2_rekey_special);
11249 ADD_SPECIALS(ssh2_session_specials);
11250 } /* else we're not ready yet */
11253 ADD_SPECIALS(specials_end);
11254 return ssh_specials;
11258 #undef ADD_SPECIALS
11262 * Send special codes. TS_EOF is useful for `plink', so you
11263 * can send an EOF and collect resulting output (e.g. `plink
11266 static void ssh_special(void *handle, Telnet_Special code)
11268 Ssh ssh = (Ssh) handle;
11269 struct Packet *pktout;
11271 if (code == TS_EOF) {
11272 if (ssh->state != SSH_STATE_SESSION) {
11274 * Buffer the EOF in case we are pre-SESSION, so we can
11275 * send it as soon as we reach SESSION.
11277 if (code == TS_EOF)
11278 ssh->eof_needed = TRUE;
11281 if (ssh->version == 1) {
11282 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11283 } else if (ssh->mainchan) {
11284 sshfwd_write_eof(ssh->mainchan);
11285 ssh->send_ok = 0; /* now stop trying to read from stdin */
11287 logevent("Sent EOF message");
11288 } else if (code == TS_PING || code == TS_NOP) {
11289 if (ssh->state == SSH_STATE_CLOSED
11290 || ssh->state == SSH_STATE_PREPACKET) return;
11291 if (ssh->version == 1) {
11292 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11293 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11295 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11296 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11297 ssh2_pkt_addstring_start(pktout);
11298 ssh2_pkt_send_noqueue(ssh, pktout);
11301 } else if (code == TS_REKEY) {
11302 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11303 ssh->version == 2) {
11304 do_ssh2_transport(ssh, "at user request", -1, NULL);
11306 } else if (code == TS_BRK) {
11307 if (ssh->state == SSH_STATE_CLOSED
11308 || ssh->state == SSH_STATE_PREPACKET) return;
11309 if (ssh->version == 1) {
11310 logevent("Unable to send BREAK signal in SSH-1");
11311 } else if (ssh->mainchan) {
11312 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11313 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11314 ssh2_pkt_send(ssh, pktout);
11317 /* Is is a POSIX signal? */
11318 char *signame = NULL;
11319 if (code == TS_SIGABRT) signame = "ABRT";
11320 if (code == TS_SIGALRM) signame = "ALRM";
11321 if (code == TS_SIGFPE) signame = "FPE";
11322 if (code == TS_SIGHUP) signame = "HUP";
11323 if (code == TS_SIGILL) signame = "ILL";
11324 if (code == TS_SIGINT) signame = "INT";
11325 if (code == TS_SIGKILL) signame = "KILL";
11326 if (code == TS_SIGPIPE) signame = "PIPE";
11327 if (code == TS_SIGQUIT) signame = "QUIT";
11328 if (code == TS_SIGSEGV) signame = "SEGV";
11329 if (code == TS_SIGTERM) signame = "TERM";
11330 if (code == TS_SIGUSR1) signame = "USR1";
11331 if (code == TS_SIGUSR2) signame = "USR2";
11332 /* The SSH-2 protocol does in principle support arbitrary named
11333 * signals, including signame@domain, but we don't support those. */
11335 /* It's a signal. */
11336 if (ssh->version == 2 && ssh->mainchan) {
11337 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11338 ssh2_pkt_addstring(pktout, signame);
11339 ssh2_pkt_send(ssh, pktout);
11340 logeventf(ssh, "Sent signal SIG%s", signame);
11343 /* Never heard of it. Do nothing */
11348 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11350 Ssh ssh = (Ssh) handle;
11351 struct ssh_channel *c;
11352 c = snew(struct ssh_channel);
11355 ssh2_channel_init(c);
11356 c->halfopen = TRUE;
11357 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11359 add234(ssh->channels, c);
11363 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11365 struct ssh_channel *c;
11366 c = snew(struct ssh_channel);
11369 ssh2_channel_init(c);
11370 c->type = CHAN_SHARING;
11371 c->u.sharing.ctx = sharing_ctx;
11372 add234(ssh->channels, c);
11376 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11378 struct ssh_channel *c;
11380 c = find234(ssh->channels, &localid, ssh_channelfind);
11382 ssh_channel_destroy(c);
11385 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11386 const void *data, int datalen,
11387 const char *additional_log_text)
11389 struct Packet *pkt;
11391 pkt = ssh2_pkt_init(type);
11392 pkt->downstream_id = id;
11393 pkt->additional_log_text = additional_log_text;
11394 ssh2_pkt_adddata(pkt, data, datalen);
11395 ssh2_pkt_send(ssh, pkt);
11399 * This is called when stdout/stderr (the entity to which
11400 * from_backend sends data) manages to clear some backlog.
11402 static void ssh_unthrottle(void *handle, int bufsize)
11404 Ssh ssh = (Ssh) handle;
11407 if (ssh->version == 1) {
11408 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11409 ssh->v1_stdout_throttling = 0;
11410 ssh_throttle_conn(ssh, -1);
11413 if (ssh->mainchan) {
11414 ssh2_set_window(ssh->mainchan,
11415 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11416 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11417 if (ssh_is_simple(ssh))
11420 buflimit = ssh->mainchan->v.v2.locmaxwin;
11421 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11422 ssh->mainchan->throttling_conn = 0;
11423 ssh_throttle_conn(ssh, -1);
11429 * Now process any SSH connection data that was stashed in our
11430 * queue while we were frozen.
11432 ssh_process_queued_incoming_data(ssh);
11435 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11437 struct ssh_channel *c = (struct ssh_channel *)channel;
11439 struct Packet *pktout;
11441 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11443 if (ssh->version == 1) {
11444 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11445 PKT_INT, c->localid,
11448 /* PKT_STR, <org:orgport>, */
11451 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11453 char *trimmed_host = host_strduptrim(hostname);
11454 ssh2_pkt_addstring(pktout, trimmed_host);
11455 sfree(trimmed_host);
11457 ssh2_pkt_adduint32(pktout, port);
11459 * We make up values for the originator data; partly it's
11460 * too much hassle to keep track, and partly I'm not
11461 * convinced the server should be told details like that
11462 * about my local network configuration.
11463 * The "originator IP address" is syntactically a numeric
11464 * IP address, and some servers (e.g., Tectia) get upset
11465 * if it doesn't match this syntax.
11467 ssh2_pkt_addstring(pktout, "0.0.0.0");
11468 ssh2_pkt_adduint32(pktout, 0);
11469 ssh2_pkt_send(ssh, pktout);
11473 static int ssh_connected(void *handle)
11475 Ssh ssh = (Ssh) handle;
11476 return ssh->s != NULL;
11479 static int ssh_sendok(void *handle)
11481 Ssh ssh = (Ssh) handle;
11482 return ssh->send_ok;
11485 static int ssh_ldisc(void *handle, int option)
11487 Ssh ssh = (Ssh) handle;
11488 if (option == LD_ECHO)
11489 return ssh->echoing;
11490 if (option == LD_EDIT)
11491 return ssh->editing;
11495 static void ssh_provide_ldisc(void *handle, void *ldisc)
11497 Ssh ssh = (Ssh) handle;
11498 ssh->ldisc = ldisc;
11501 static void ssh_provide_logctx(void *handle, void *logctx)
11503 Ssh ssh = (Ssh) handle;
11504 ssh->logctx = logctx;
11507 static int ssh_return_exitcode(void *handle)
11509 Ssh ssh = (Ssh) handle;
11510 if (ssh->s != NULL)
11513 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11517 * cfg_info for SSH is the protocol running in this session.
11518 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11519 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11521 static int ssh_cfg_info(void *handle)
11523 Ssh ssh = (Ssh) handle;
11524 if (ssh->version == 0)
11525 return 0; /* don't know yet */
11526 else if (ssh->bare_connection)
11529 return ssh->version;
11533 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11534 * that fails. This variable is the means by which scp.c can reach
11535 * into the SSH code and find out which one it got.
11537 extern int ssh_fallback_cmd(void *handle)
11539 Ssh ssh = (Ssh) handle;
11540 return ssh->fallback_cmd;
11543 Backend ssh_backend = {
11553 ssh_return_exitcode,
11557 ssh_provide_logctx,