28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
39 SSH2_PKTCTX_PUBLICKEY,
45 static const char *const ssh2_disconnect_reasons[] = {
47 "host not allowed to connect",
49 "key exchange failed",
50 "host authentication failed",
53 "service not available",
54 "protocol version not supported",
55 "host key not verifiable",
58 "too many connections",
59 "auth cancelled by user",
60 "no more auth methods available",
65 * Various remote-bug flags.
67 #define BUG_CHOKES_ON_SSH1_IGNORE 1
68 #define BUG_SSH2_HMAC 2
69 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
70 #define BUG_CHOKES_ON_RSA 8
71 #define BUG_SSH2_RSA_PADDING 16
72 #define BUG_SSH2_DERIVEKEY 32
73 #define BUG_SSH2_REKEY 64
74 #define BUG_SSH2_PK_SESSIONID 128
75 #define BUG_SSH2_MAXPKT 256
76 #define BUG_CHOKES_ON_SSH2_IGNORE 512
77 #define BUG_CHOKES_ON_WINADJ 1024
80 * Codes for terminal modes.
81 * Most of these are the same in SSH-1 and SSH-2.
82 * This list is derived from RFC 4254 and
86 const char* const mode;
88 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
90 /* "V" prefix discarded for special characters relative to SSH specs */
91 { "INTR", 1, TTY_OP_CHAR },
92 { "QUIT", 2, TTY_OP_CHAR },
93 { "ERASE", 3, TTY_OP_CHAR },
94 { "KILL", 4, TTY_OP_CHAR },
95 { "EOF", 5, TTY_OP_CHAR },
96 { "EOL", 6, TTY_OP_CHAR },
97 { "EOL2", 7, TTY_OP_CHAR },
98 { "START", 8, TTY_OP_CHAR },
99 { "STOP", 9, TTY_OP_CHAR },
100 { "SUSP", 10, TTY_OP_CHAR },
101 { "DSUSP", 11, TTY_OP_CHAR },
102 { "REPRINT", 12, TTY_OP_CHAR },
103 { "WERASE", 13, TTY_OP_CHAR },
104 { "LNEXT", 14, TTY_OP_CHAR },
105 { "FLUSH", 15, TTY_OP_CHAR },
106 { "SWTCH", 16, TTY_OP_CHAR },
107 { "STATUS", 17, TTY_OP_CHAR },
108 { "DISCARD", 18, TTY_OP_CHAR },
109 { "IGNPAR", 30, TTY_OP_BOOL },
110 { "PARMRK", 31, TTY_OP_BOOL },
111 { "INPCK", 32, TTY_OP_BOOL },
112 { "ISTRIP", 33, TTY_OP_BOOL },
113 { "INLCR", 34, TTY_OP_BOOL },
114 { "IGNCR", 35, TTY_OP_BOOL },
115 { "ICRNL", 36, TTY_OP_BOOL },
116 { "IUCLC", 37, TTY_OP_BOOL },
117 { "IXON", 38, TTY_OP_BOOL },
118 { "IXANY", 39, TTY_OP_BOOL },
119 { "IXOFF", 40, TTY_OP_BOOL },
120 { "IMAXBEL", 41, TTY_OP_BOOL },
121 { "ISIG", 50, TTY_OP_BOOL },
122 { "ICANON", 51, TTY_OP_BOOL },
123 { "XCASE", 52, TTY_OP_BOOL },
124 { "ECHO", 53, TTY_OP_BOOL },
125 { "ECHOE", 54, TTY_OP_BOOL },
126 { "ECHOK", 55, TTY_OP_BOOL },
127 { "ECHONL", 56, TTY_OP_BOOL },
128 { "NOFLSH", 57, TTY_OP_BOOL },
129 { "TOSTOP", 58, TTY_OP_BOOL },
130 { "IEXTEN", 59, TTY_OP_BOOL },
131 { "ECHOCTL", 60, TTY_OP_BOOL },
132 { "ECHOKE", 61, TTY_OP_BOOL },
133 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
134 { "OPOST", 70, TTY_OP_BOOL },
135 { "OLCUC", 71, TTY_OP_BOOL },
136 { "ONLCR", 72, TTY_OP_BOOL },
137 { "OCRNL", 73, TTY_OP_BOOL },
138 { "ONOCR", 74, TTY_OP_BOOL },
139 { "ONLRET", 75, TTY_OP_BOOL },
140 { "CS7", 90, TTY_OP_BOOL },
141 { "CS8", 91, TTY_OP_BOOL },
142 { "PARENB", 92, TTY_OP_BOOL },
143 { "PARODD", 93, TTY_OP_BOOL }
146 /* Miscellaneous other tty-related constants. */
147 #define SSH_TTY_OP_END 0
148 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
149 #define SSH1_TTY_OP_ISPEED 192
150 #define SSH1_TTY_OP_OSPEED 193
151 #define SSH2_TTY_OP_ISPEED 128
152 #define SSH2_TTY_OP_OSPEED 129
154 /* Helper functions for parsing tty-related config. */
155 static unsigned int ssh_tty_parse_specchar(char *s)
160 ret = ctrlparse(s, &next);
161 if (!next) ret = s[0];
163 ret = 255; /* special value meaning "don't set" */
167 static unsigned int ssh_tty_parse_boolean(char *s)
169 if (stricmp(s, "yes") == 0 ||
170 stricmp(s, "on") == 0 ||
171 stricmp(s, "true") == 0 ||
172 stricmp(s, "+") == 0)
174 else if (stricmp(s, "no") == 0 ||
175 stricmp(s, "off") == 0 ||
176 stricmp(s, "false") == 0 ||
177 stricmp(s, "-") == 0)
178 return 0; /* false */
180 return (atoi(s) != 0);
183 #define translate(x) if (type == x) return #x
184 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
185 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
186 static char *ssh1_pkt_type(int type)
188 translate(SSH1_MSG_DISCONNECT);
189 translate(SSH1_SMSG_PUBLIC_KEY);
190 translate(SSH1_CMSG_SESSION_KEY);
191 translate(SSH1_CMSG_USER);
192 translate(SSH1_CMSG_AUTH_RSA);
193 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
194 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
195 translate(SSH1_CMSG_AUTH_PASSWORD);
196 translate(SSH1_CMSG_REQUEST_PTY);
197 translate(SSH1_CMSG_WINDOW_SIZE);
198 translate(SSH1_CMSG_EXEC_SHELL);
199 translate(SSH1_CMSG_EXEC_CMD);
200 translate(SSH1_SMSG_SUCCESS);
201 translate(SSH1_SMSG_FAILURE);
202 translate(SSH1_CMSG_STDIN_DATA);
203 translate(SSH1_SMSG_STDOUT_DATA);
204 translate(SSH1_SMSG_STDERR_DATA);
205 translate(SSH1_CMSG_EOF);
206 translate(SSH1_SMSG_EXIT_STATUS);
207 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
208 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
209 translate(SSH1_MSG_CHANNEL_DATA);
210 translate(SSH1_MSG_CHANNEL_CLOSE);
211 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
212 translate(SSH1_SMSG_X11_OPEN);
213 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
214 translate(SSH1_MSG_PORT_OPEN);
215 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
216 translate(SSH1_SMSG_AGENT_OPEN);
217 translate(SSH1_MSG_IGNORE);
218 translate(SSH1_CMSG_EXIT_CONFIRMATION);
219 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
220 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
221 translate(SSH1_MSG_DEBUG);
222 translate(SSH1_CMSG_REQUEST_COMPRESSION);
223 translate(SSH1_CMSG_AUTH_TIS);
224 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
225 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
226 translate(SSH1_CMSG_AUTH_CCARD);
227 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
228 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
231 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
233 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
234 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
235 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
236 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
237 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
239 translate(SSH2_MSG_DISCONNECT);
240 translate(SSH2_MSG_IGNORE);
241 translate(SSH2_MSG_UNIMPLEMENTED);
242 translate(SSH2_MSG_DEBUG);
243 translate(SSH2_MSG_SERVICE_REQUEST);
244 translate(SSH2_MSG_SERVICE_ACCEPT);
245 translate(SSH2_MSG_KEXINIT);
246 translate(SSH2_MSG_NEWKEYS);
247 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
248 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
249 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
250 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
251 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
252 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
253 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
254 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
255 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
256 translate(SSH2_MSG_USERAUTH_REQUEST);
257 translate(SSH2_MSG_USERAUTH_FAILURE);
258 translate(SSH2_MSG_USERAUTH_SUCCESS);
259 translate(SSH2_MSG_USERAUTH_BANNER);
260 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
261 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
262 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
263 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
264 translate(SSH2_MSG_GLOBAL_REQUEST);
265 translate(SSH2_MSG_REQUEST_SUCCESS);
266 translate(SSH2_MSG_REQUEST_FAILURE);
267 translate(SSH2_MSG_CHANNEL_OPEN);
268 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
269 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
270 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
271 translate(SSH2_MSG_CHANNEL_DATA);
272 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
273 translate(SSH2_MSG_CHANNEL_EOF);
274 translate(SSH2_MSG_CHANNEL_CLOSE);
275 translate(SSH2_MSG_CHANNEL_REQUEST);
276 translate(SSH2_MSG_CHANNEL_SUCCESS);
277 translate(SSH2_MSG_CHANNEL_FAILURE);
283 /* Enumeration values for fields in SSH-1 packets */
285 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
289 * Coroutine mechanics for the sillier bits of the code. If these
290 * macros look impenetrable to you, you might find it helpful to
293 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
295 * which explains the theory behind these macros.
297 * In particular, if you are getting `case expression not constant'
298 * errors when building with MS Visual Studio, this is because MS's
299 * Edit and Continue debugging feature causes their compiler to
300 * violate ANSI C. To disable Edit and Continue debugging:
302 * - right-click ssh.c in the FileView
304 * - select the C/C++ tab and the General category
305 * - under `Debug info:', select anything _other_ than `Program
306 * Database for Edit and Continue'.
308 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
309 #define crBeginState crBegin(s->crLine)
310 #define crStateP(t, v) \
312 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
314 #define crState(t) crStateP(t, ssh->t)
315 #define crFinish(z) } *crLine = 0; return (z); }
316 #define crFinishV } *crLine = 0; return; }
317 #define crFinishFree(z) } sfree(s); return (z); }
318 #define crFinishFreeV } sfree(s); return; }
319 #define crReturn(z) \
321 *crLine =__LINE__; return (z); case __LINE__:;\
325 *crLine=__LINE__; return; case __LINE__:;\
327 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
328 #define crStopV do{ *crLine = 0; return; }while(0)
329 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
330 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
332 typedef struct ssh_tag *Ssh;
335 static struct Packet *ssh1_pkt_init(int pkt_type);
336 static struct Packet *ssh2_pkt_init(int pkt_type);
337 static void ssh_pkt_ensure(struct Packet *, int length);
338 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
339 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
340 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
341 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
342 static void ssh_pkt_addstring_start(struct Packet *);
343 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
344 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
345 static void ssh_pkt_addstring(struct Packet *, const char *data);
346 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
347 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
348 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
349 static int ssh2_pkt_construct(Ssh, struct Packet *);
350 static void ssh2_pkt_send(Ssh, struct Packet *);
351 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
352 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
353 struct Packet *pktin);
354 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
355 struct Packet *pktin);
356 static void ssh2_channel_check_close(struct ssh_channel *c);
357 static void ssh_channel_destroy(struct ssh_channel *c);
360 * Buffer management constants. There are several of these for
361 * various different purposes:
363 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
364 * on a local data stream before we throttle the whole SSH
365 * connection (in SSH-1 only). Throttling the whole connection is
366 * pretty drastic so we set this high in the hope it won't
369 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
370 * on the SSH connection itself before we defensively throttle
371 * _all_ local data streams. This is pretty drastic too (though
372 * thankfully unlikely in SSH-2 since the window mechanism should
373 * ensure that the server never has any need to throttle its end
374 * of the connection), so we set this high as well.
376 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
379 * - OUR_V2_BIGWIN is the window size we advertise for the only
380 * channel in a simple connection. It must be <= INT_MAX.
382 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
383 * to the remote side. This actually has nothing to do with the
384 * size of the _packet_, but is instead a limit on the amount
385 * of data we're willing to receive in a single SSH2 channel
388 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
389 * _packet_ we're prepared to cope with. It must be a multiple
390 * of the cipher block size, and must be at least 35000.
393 #define SSH1_BUFFER_LIMIT 32768
394 #define SSH_MAX_BACKLOG 32768
395 #define OUR_V2_WINSIZE 16384
396 #define OUR_V2_BIGWIN 0x7fffffff
397 #define OUR_V2_MAXPKT 0x4000UL
398 #define OUR_V2_PACKETLIMIT 0x9000UL
400 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
402 const static struct ssh_mac *macs[] = {
403 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
405 const static struct ssh_mac *buggymacs[] = {
406 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
409 static void *ssh_comp_none_init(void)
413 static void ssh_comp_none_cleanup(void *handle)
416 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
417 unsigned char **outblock, int *outlen)
421 static int ssh_comp_none_disable(void *handle)
425 const static struct ssh_compress ssh_comp_none = {
427 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
428 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
429 ssh_comp_none_disable, NULL
431 extern const struct ssh_compress ssh_zlib;
432 const static struct ssh_compress *compressions[] = {
433 &ssh_zlib, &ssh_comp_none
436 enum { /* channel types */
441 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
443 * CHAN_ZOMBIE is used to indicate a channel for which we've
444 * already destroyed the local data source: for instance, if a
445 * forwarded port experiences a socket error on the local side, we
446 * immediately destroy its local socket and turn the SSH channel
452 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
453 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
454 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
457 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
460 struct outstanding_channel_request {
461 cchandler_fn_t handler;
463 struct outstanding_channel_request *next;
467 * 2-3-4 tree storing channels.
470 Ssh ssh; /* pointer back to main context */
471 unsigned remoteid, localid;
473 /* True if we opened this channel but server hasn't confirmed. */
476 * In SSH-1, this value contains four bits:
478 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
479 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
480 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
481 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
483 * A channel is completely finished with when all four bits are set.
485 * In SSH-2, the four bits mean:
487 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
488 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
489 * 4 We have received SSH2_MSG_CHANNEL_EOF.
490 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
492 * A channel is completely finished with when we have both sent
493 * and received CLOSE.
495 * The symbolic constants below use the SSH-2 terminology, which
496 * is a bit confusing in SSH-1, but we have to use _something_.
498 #define CLOSES_SENT_EOF 1
499 #define CLOSES_SENT_CLOSE 2
500 #define CLOSES_RCVD_EOF 4
501 #define CLOSES_RCVD_CLOSE 8
505 * This flag indicates that an EOF is pending on the outgoing side
506 * of the channel: that is, wherever we're getting the data for
507 * this channel has sent us some data followed by EOF. We can't
508 * actually send the EOF until we've finished sending the data, so
509 * we set this flag instead to remind us to do so once our buffer
515 * True if this channel is causing the underlying connection to be
520 struct ssh2_data_channel {
522 unsigned remwindow, remmaxpkt;
523 /* locwindow is signed so we can cope with excess data. */
524 int locwindow, locmaxwin;
526 * remlocwin is the amount of local window that we think
527 * the remote end had available to it after it sent the
528 * last data packet or window adjust ack.
532 * These store the list of channel requests that haven't
535 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
536 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
540 struct ssh_agent_channel {
541 unsigned char *message;
542 unsigned char msglen[4];
543 unsigned lensofar, totallen;
544 int outstanding_requests;
546 struct ssh_x11_channel {
549 struct ssh_pfd_channel {
556 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
557 * use this structure in different ways, reflecting SSH-2's
558 * altogether saner approach to port forwarding.
560 * In SSH-1, you arrange a remote forwarding by sending the server
561 * the remote port number, and the local destination host:port.
562 * When a connection comes in, the server sends you back that
563 * host:port pair, and you connect to it. This is a ready-made
564 * security hole if you're not on the ball: a malicious server
565 * could send you back _any_ host:port pair, so if you trustingly
566 * connect to the address it gives you then you've just opened the
567 * entire inside of your corporate network just by connecting
568 * through it to a dodgy SSH server. Hence, we must store a list of
569 * host:port pairs we _are_ trying to forward to, and reject a
570 * connection request from the server if it's not in the list.
572 * In SSH-2, each side of the connection minds its own business and
573 * doesn't send unnecessary information to the other. You arrange a
574 * remote forwarding by sending the server just the remote port
575 * number. When a connection comes in, the server tells you which
576 * of its ports was connected to; and _you_ have to remember what
577 * local host:port pair went with that port number.
579 * Hence, in SSH-1 this structure is indexed by destination
580 * host:port pair, whereas in SSH-2 it is indexed by source port.
582 struct ssh_portfwd; /* forward declaration */
584 struct ssh_rportfwd {
585 unsigned sport, dport;
588 struct ssh_portfwd *pfrec;
591 static void free_rportfwd(struct ssh_rportfwd *pf)
594 sfree(pf->sportdesc);
602 * Separately to the rportfwd tree (which is for looking up port
603 * open requests from the server), a tree of _these_ structures is
604 * used to keep track of all the currently open port forwardings,
605 * so that we can reconfigure in mid-session if the user requests
609 enum { DESTROY, KEEP, CREATE } status;
611 unsigned sport, dport;
614 struct ssh_rportfwd *remote;
618 #define free_portfwd(pf) ( \
619 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
620 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
623 long length; /* length of packet: see below */
624 long forcepad; /* SSH-2: force padding to at least this length */
625 int type; /* only used for incoming packets */
626 unsigned long sequence; /* SSH-2 incoming sequence number */
627 unsigned char *data; /* allocated storage */
628 unsigned char *body; /* offset of payload within `data' */
629 long savedpos; /* dual-purpose saved packet position: see below */
630 long maxlen; /* amount of storage allocated for `data' */
631 long encrypted_len; /* for SSH-2 total-size counting */
634 * A note on the 'length' and 'savedpos' fields above.
636 * Incoming packets are set up so that pkt->length is measured
637 * relative to pkt->body, which itself points to a few bytes after
638 * pkt->data (skipping some uninteresting header fields including
639 * the packet type code). The ssh_pkt_get* functions all expect
640 * this setup, and they also use pkt->savedpos to indicate how far
641 * through the packet being decoded they've got - and that, too,
642 * is an offset from pkt->body rather than pkt->data.
644 * During construction of an outgoing packet, however, pkt->length
645 * is measured relative to the base pointer pkt->data, and
646 * pkt->body is not really used for anything until the packet is
647 * ready for sending. In this mode, pkt->savedpos is reused as a
648 * temporary variable by the addstring functions, which write out
649 * a string length field and then keep going back and updating it
650 * as more data is appended to the subsequent string data field;
651 * pkt->savedpos stores the offset (again relative to pkt->data)
652 * of the start of the string data field.
656 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
657 struct Packet *pktin);
658 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
659 struct Packet *pktin);
660 static void ssh1_protocol_setup(Ssh ssh);
661 static void ssh2_protocol_setup(Ssh ssh);
662 static void ssh_size(void *handle, int width, int height);
663 static void ssh_special(void *handle, Telnet_Special);
664 static int ssh2_try_send(struct ssh_channel *c);
665 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
666 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
667 static void ssh2_set_window(struct ssh_channel *c, int newwin);
668 static int ssh_sendbuffer(void *handle);
669 static int ssh_do_close(Ssh ssh, int notify_exit);
670 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
671 static int ssh2_pkt_getbool(struct Packet *pkt);
672 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
673 static void ssh2_timer(void *ctx, unsigned long now);
674 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
675 struct Packet *pktin);
676 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
678 struct rdpkt1_state_tag {
679 long len, pad, biglen, to_read;
680 unsigned long realcrc, gotcrc;
684 struct Packet *pktin;
687 struct rdpkt2_state_tag {
688 long len, pad, payload, packetlen, maclen;
691 unsigned long incoming_sequence;
692 struct Packet *pktin;
695 struct queued_handler;
696 struct queued_handler {
698 chandler_fn_t handler;
700 struct queued_handler *next;
704 const struct plug_function_table *fn;
705 /* the above field _must_ be first in the structure */
715 unsigned char session_key[32];
717 int v1_remote_protoflags;
718 int v1_local_protoflags;
719 int agentfwd_enabled;
722 const struct ssh_cipher *cipher;
725 const struct ssh2_cipher *cscipher, *sccipher;
726 void *cs_cipher_ctx, *sc_cipher_ctx;
727 const struct ssh_mac *csmac, *scmac;
728 void *cs_mac_ctx, *sc_mac_ctx;
729 const struct ssh_compress *cscomp, *sccomp;
730 void *cs_comp_ctx, *sc_comp_ctx;
731 const struct ssh_kex *kex;
732 const struct ssh_signkey *hostkey;
733 char *hostkey_str; /* string representation, for easy checking in rekeys */
734 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
735 int v2_session_id_len;
741 int echoing, editing;
745 int ospeed, ispeed; /* temporaries */
746 int term_width, term_height;
748 tree234 *channels; /* indexed by local id */
749 struct ssh_channel *mainchan; /* primary session channel */
750 int ncmode; /* is primary channel direct-tcpip? */
755 tree234 *rportfwds, *portfwds;
759 SSH_STATE_BEFORE_SIZE,
765 int size_needed, eof_needed;
766 int sent_console_eof;
767 int got_pty; /* affects EOF behaviour on main channel */
769 struct Packet **queue;
770 int queuelen, queuesize;
772 unsigned char *deferred_send_data;
773 int deferred_len, deferred_size;
776 * Gross hack: pscp will try to start SFTP but fall back to
777 * scp1 if that fails. This variable is the means by which
778 * scp.c can reach into the SSH code and find out which one it
783 bufchain banner; /* accumulates banners during do_ssh2_authconn */
788 struct X11Display *x11disp;
791 int conn_throttle_count;
794 int v1_stdout_throttling;
795 unsigned long v2_outgoing_sequence;
797 int ssh1_rdpkt_crstate;
798 int ssh2_rdpkt_crstate;
799 int ssh_gotdata_crstate;
800 int do_ssh1_connection_crstate;
802 void *do_ssh_init_state;
803 void *do_ssh1_login_state;
804 void *do_ssh2_transport_state;
805 void *do_ssh2_authconn_state;
807 struct rdpkt1_state_tag rdpkt1_state;
808 struct rdpkt2_state_tag rdpkt2_state;
810 /* SSH-1 and SSH-2 use this for different things, but both use it */
811 int protocol_initial_phase_done;
813 void (*protocol) (Ssh ssh, void *vin, int inlen,
815 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
818 * We maintain our own copy of a Conf structure here. That way,
819 * when we're passed a new one for reconfiguration, we can check
820 * the differences and potentially reconfigure port forwardings
821 * etc in mid-session.
826 * Values cached out of conf so as to avoid the tree234 lookup
827 * cost every time they're used.
832 * Dynamically allocated username string created during SSH
833 * login. Stored in here rather than in the coroutine state so
834 * that it'll be reliably freed if we shut down the SSH session
835 * at some unexpected moment.
840 * Used to transfer data back from async callbacks.
842 void *agent_response;
843 int agent_response_len;
847 * The SSH connection can be set as `frozen', meaning we are
848 * not currently accepting incoming data from the network. This
849 * is slightly more serious than setting the _socket_ as
850 * frozen, because we may already have had data passed to us
851 * from the network which we need to delay processing until
852 * after the freeze is lifted, so we also need a bufchain to
856 bufchain queued_incoming_data;
859 * Dispatch table for packet types that we may have to deal
862 handler_fn_t packet_dispatch[256];
865 * Queues of one-off handler functions for success/failure
866 * indications from a request.
868 struct queued_handler *qhead, *qtail;
869 handler_fn_t q_saved_handler1, q_saved_handler2;
872 * This module deals with sending keepalives.
877 * Track incoming and outgoing data sizes and time, for
880 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
881 unsigned long max_data_size;
883 unsigned long next_rekey, last_rekey;
884 char *deferred_rekey_reason; /* points to STATIC string; don't free */
887 * Fully qualified host name, which we need if doing GSSAPI.
893 * GSSAPI libraries for this session.
895 struct ssh_gss_liblist *gsslibs;
899 #define logevent(s) logevent(ssh->frontend, s)
901 /* logevent, only printf-formatted. */
902 static void logeventf(Ssh ssh, const char *fmt, ...)
908 buf = dupvprintf(fmt, ap);
914 static void bomb_out(Ssh ssh, char *text)
916 ssh_do_close(ssh, FALSE);
918 connection_fatal(ssh->frontend, "%s", text);
922 #define bombout(msg) bomb_out(ssh, dupprintf msg)
924 /* Helper function for common bits of parsing ttymodes. */
925 static void parse_ttymodes(Ssh ssh,
926 void (*do_mode)(void *data, char *mode, char *val),
931 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
933 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
935 * val[0] is either 'V', indicating that an explicit value
936 * follows it, or 'A' indicating that we should pass the
937 * value through from the local environment via get_ttymode.
940 val = get_ttymode(ssh->frontend, key);
942 do_mode(data, key, val);
946 do_mode(data, key, val + 1); /* skip the 'V' */
950 static int ssh_channelcmp(void *av, void *bv)
952 struct ssh_channel *a = (struct ssh_channel *) av;
953 struct ssh_channel *b = (struct ssh_channel *) bv;
954 if (a->localid < b->localid)
956 if (a->localid > b->localid)
960 static int ssh_channelfind(void *av, void *bv)
962 unsigned *a = (unsigned *) av;
963 struct ssh_channel *b = (struct ssh_channel *) bv;
971 static int ssh_rportcmp_ssh1(void *av, void *bv)
973 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
974 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
976 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
977 return i < 0 ? -1 : +1;
978 if (a->dport > b->dport)
980 if (a->dport < b->dport)
985 static int ssh_rportcmp_ssh2(void *av, void *bv)
987 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
988 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
990 if ( (i = strcmp(a->shost, b->shost)) != 0)
991 return i < 0 ? -1 : +1;
992 if (a->sport > b->sport)
994 if (a->sport < b->sport)
1000 * Special form of strcmp which can cope with NULL inputs. NULL is
1001 * defined to sort before even the empty string.
1003 static int nullstrcmp(const char *a, const char *b)
1005 if (a == NULL && b == NULL)
1011 return strcmp(a, b);
1014 static int ssh_portcmp(void *av, void *bv)
1016 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1017 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1019 if (a->type > b->type)
1021 if (a->type < b->type)
1023 if (a->addressfamily > b->addressfamily)
1025 if (a->addressfamily < b->addressfamily)
1027 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1028 return i < 0 ? -1 : +1;
1029 if (a->sport > b->sport)
1031 if (a->sport < b->sport)
1033 if (a->type != 'D') {
1034 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1035 return i < 0 ? -1 : +1;
1036 if (a->dport > b->dport)
1038 if (a->dport < b->dport)
1044 static int alloc_channel_id(Ssh ssh)
1046 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1047 unsigned low, high, mid;
1049 struct ssh_channel *c;
1052 * First-fit allocation of channel numbers: always pick the
1053 * lowest unused one. To do this, binary-search using the
1054 * counted B-tree to find the largest channel ID which is in a
1055 * contiguous sequence from the beginning. (Precisely
1056 * everything in that sequence must have ID equal to its tree
1057 * index plus CHANNEL_NUMBER_OFFSET.)
1059 tsize = count234(ssh->channels);
1063 while (high - low > 1) {
1064 mid = (high + low) / 2;
1065 c = index234(ssh->channels, mid);
1066 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1067 low = mid; /* this one is fine */
1069 high = mid; /* this one is past it */
1072 * Now low points to either -1, or the tree index of the
1073 * largest ID in the initial sequence.
1076 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1077 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1079 return low + 1 + CHANNEL_NUMBER_OFFSET;
1082 static void c_write_stderr(int trusted, const char *buf, int len)
1085 for (i = 0; i < len; i++)
1086 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1087 fputc(buf[i], stderr);
1090 static void c_write(Ssh ssh, const char *buf, int len)
1092 if (flags & FLAG_STDERR)
1093 c_write_stderr(1, buf, len);
1095 from_backend(ssh->frontend, 1, buf, len);
1098 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1100 if (flags & FLAG_STDERR)
1101 c_write_stderr(0, buf, len);
1103 from_backend_untrusted(ssh->frontend, buf, len);
1106 static void c_write_str(Ssh ssh, const char *buf)
1108 c_write(ssh, buf, strlen(buf));
1111 static void ssh_free_packet(struct Packet *pkt)
1116 static struct Packet *ssh_new_packet(void)
1118 struct Packet *pkt = snew(struct Packet);
1120 pkt->body = pkt->data = NULL;
1126 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1129 struct logblank_t blanks[4];
1135 if (ssh->logomitdata &&
1136 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1137 pkt->type == SSH1_SMSG_STDERR_DATA ||
1138 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1139 /* "Session data" packets - omit the data string. */
1140 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1141 ssh_pkt_getuint32(pkt); /* skip channel id */
1142 blanks[nblanks].offset = pkt->savedpos + 4;
1143 blanks[nblanks].type = PKTLOG_OMIT;
1144 ssh_pkt_getstring(pkt, &str, &slen);
1146 blanks[nblanks].len = slen;
1150 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1151 ssh1_pkt_type(pkt->type),
1152 pkt->body, pkt->length, nblanks, blanks, NULL);
1155 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1158 struct logblank_t blanks[4];
1163 * For outgoing packets, pkt->length represents the length of the
1164 * whole packet starting at pkt->data (including some header), and
1165 * pkt->body refers to the point within that where the log-worthy
1166 * payload begins. However, incoming packets expect pkt->length to
1167 * represent only the payload length (that is, it's measured from
1168 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1169 * packet to conform to the incoming-packet semantics, so that we
1170 * can analyse it with the ssh_pkt_get functions.
1172 pkt->length -= (pkt->body - pkt->data);
1175 if (ssh->logomitdata &&
1176 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1177 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1178 /* "Session data" packets - omit the data string. */
1179 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1180 ssh_pkt_getuint32(pkt); /* skip channel id */
1181 blanks[nblanks].offset = pkt->savedpos + 4;
1182 blanks[nblanks].type = PKTLOG_OMIT;
1183 ssh_pkt_getstring(pkt, &str, &slen);
1185 blanks[nblanks].len = slen;
1190 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1191 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1192 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1193 conf_get_int(ssh->conf, CONF_logomitpass)) {
1194 /* If this is a password or similar packet, blank the password(s). */
1195 blanks[nblanks].offset = 0;
1196 blanks[nblanks].len = pkt->length;
1197 blanks[nblanks].type = PKTLOG_BLANK;
1199 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1200 conf_get_int(ssh->conf, CONF_logomitpass)) {
1202 * If this is an X forwarding request packet, blank the fake
1205 * Note that while we blank the X authentication data here, we
1206 * don't take any special action to blank the start of an X11
1207 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1208 * an X connection without having session blanking enabled is
1209 * likely to leak your cookie into the log.
1212 ssh_pkt_getstring(pkt, &str, &slen);
1213 blanks[nblanks].offset = pkt->savedpos;
1214 blanks[nblanks].type = PKTLOG_BLANK;
1215 ssh_pkt_getstring(pkt, &str, &slen);
1217 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1222 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1223 ssh1_pkt_type(pkt->data[12]),
1224 pkt->body, pkt->length,
1225 nblanks, blanks, NULL);
1228 * Undo the above adjustment of pkt->length, to put the packet
1229 * back in the state we found it.
1231 pkt->length += (pkt->body - pkt->data);
1235 * Collect incoming data in the incoming packet buffer.
1236 * Decipher and verify the packet when it is completely read.
1237 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1238 * Update the *data and *datalen variables.
1239 * Return a Packet structure when a packet is completed.
1241 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1243 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1245 crBegin(ssh->ssh1_rdpkt_crstate);
1247 st->pktin = ssh_new_packet();
1249 st->pktin->type = 0;
1250 st->pktin->length = 0;
1252 for (st->i = st->len = 0; st->i < 4; st->i++) {
1253 while ((*datalen) == 0)
1255 st->len = (st->len << 8) + **data;
1256 (*data)++, (*datalen)--;
1259 st->pad = 8 - (st->len % 8);
1260 st->biglen = st->len + st->pad;
1261 st->pktin->length = st->len - 5;
1263 if (st->biglen < 0) {
1264 bombout(("Extremely large packet length from server suggests"
1265 " data stream corruption"));
1266 ssh_free_packet(st->pktin);
1270 st->pktin->maxlen = st->biglen;
1271 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1273 st->to_read = st->biglen;
1274 st->p = st->pktin->data;
1275 while (st->to_read > 0) {
1276 st->chunk = st->to_read;
1277 while ((*datalen) == 0)
1279 if (st->chunk > (*datalen))
1280 st->chunk = (*datalen);
1281 memcpy(st->p, *data, st->chunk);
1283 *datalen -= st->chunk;
1285 st->to_read -= st->chunk;
1288 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1289 st->biglen, NULL)) {
1290 bombout(("Network attack (CRC compensation) detected!"));
1291 ssh_free_packet(st->pktin);
1296 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1298 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1299 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1300 if (st->gotcrc != st->realcrc) {
1301 bombout(("Incorrect CRC received on packet"));
1302 ssh_free_packet(st->pktin);
1306 st->pktin->body = st->pktin->data + st->pad + 1;
1308 if (ssh->v1_compressing) {
1309 unsigned char *decompblk;
1311 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1312 st->pktin->body - 1, st->pktin->length + 1,
1313 &decompblk, &decomplen)) {
1314 bombout(("Zlib decompression encountered invalid data"));
1315 ssh_free_packet(st->pktin);
1319 if (st->pktin->maxlen < st->pad + decomplen) {
1320 st->pktin->maxlen = st->pad + decomplen;
1321 st->pktin->data = sresize(st->pktin->data,
1322 st->pktin->maxlen + APIEXTRA,
1324 st->pktin->body = st->pktin->data + st->pad + 1;
1327 memcpy(st->pktin->body - 1, decompblk, decomplen);
1329 st->pktin->length = decomplen - 1;
1332 st->pktin->type = st->pktin->body[-1];
1335 * Now pktin->body and pktin->length identify the semantic content
1336 * of the packet, excluding the initial type byte.
1340 ssh1_log_incoming_packet(ssh, st->pktin);
1342 st->pktin->savedpos = 0;
1344 crFinish(st->pktin);
1347 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1350 struct logblank_t blanks[4];
1356 if (ssh->logomitdata &&
1357 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1358 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1359 /* "Session data" packets - omit the data string. */
1360 ssh_pkt_getuint32(pkt); /* skip channel id */
1361 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1362 ssh_pkt_getuint32(pkt); /* skip extended data type */
1363 blanks[nblanks].offset = pkt->savedpos + 4;
1364 blanks[nblanks].type = PKTLOG_OMIT;
1365 ssh_pkt_getstring(pkt, &str, &slen);
1367 blanks[nblanks].len = slen;
1372 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1373 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1374 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence);
1377 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1380 struct logblank_t blanks[4];
1385 * For outgoing packets, pkt->length represents the length of the
1386 * whole packet starting at pkt->data (including some header), and
1387 * pkt->body refers to the point within that where the log-worthy
1388 * payload begins. However, incoming packets expect pkt->length to
1389 * represent only the payload length (that is, it's measured from
1390 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1391 * packet to conform to the incoming-packet semantics, so that we
1392 * can analyse it with the ssh_pkt_get functions.
1394 pkt->length -= (pkt->body - pkt->data);
1397 if (ssh->logomitdata &&
1398 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1399 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1400 /* "Session data" packets - omit the data string. */
1401 ssh_pkt_getuint32(pkt); /* skip channel id */
1402 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1403 ssh_pkt_getuint32(pkt); /* skip extended data type */
1404 blanks[nblanks].offset = pkt->savedpos + 4;
1405 blanks[nblanks].type = PKTLOG_OMIT;
1406 ssh_pkt_getstring(pkt, &str, &slen);
1408 blanks[nblanks].len = slen;
1413 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1414 conf_get_int(ssh->conf, CONF_logomitpass)) {
1415 /* If this is a password packet, blank the password(s). */
1417 ssh_pkt_getstring(pkt, &str, &slen);
1418 ssh_pkt_getstring(pkt, &str, &slen);
1419 ssh_pkt_getstring(pkt, &str, &slen);
1420 if (slen == 8 && !memcmp(str, "password", 8)) {
1421 ssh2_pkt_getbool(pkt);
1422 /* Blank the password field. */
1423 blanks[nblanks].offset = pkt->savedpos;
1424 blanks[nblanks].type = PKTLOG_BLANK;
1425 ssh_pkt_getstring(pkt, &str, &slen);
1427 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1429 /* If there's another password field beyond it (change of
1430 * password), blank that too. */
1431 ssh_pkt_getstring(pkt, &str, &slen);
1433 blanks[nblanks-1].len =
1434 pkt->savedpos - blanks[nblanks].offset;
1437 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1438 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1439 conf_get_int(ssh->conf, CONF_logomitpass)) {
1440 /* If this is a keyboard-interactive response packet, blank
1443 ssh_pkt_getuint32(pkt);
1444 blanks[nblanks].offset = pkt->savedpos;
1445 blanks[nblanks].type = PKTLOG_BLANK;
1447 ssh_pkt_getstring(pkt, &str, &slen);
1451 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1453 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1454 conf_get_int(ssh->conf, CONF_logomitpass)) {
1456 * If this is an X forwarding request packet, blank the fake
1459 * Note that while we blank the X authentication data here, we
1460 * don't take any special action to blank the start of an X11
1461 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1462 * an X connection without having session blanking enabled is
1463 * likely to leak your cookie into the log.
1466 ssh_pkt_getuint32(pkt);
1467 ssh_pkt_getstring(pkt, &str, &slen);
1468 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1469 ssh2_pkt_getbool(pkt);
1470 ssh2_pkt_getbool(pkt);
1471 ssh_pkt_getstring(pkt, &str, &slen);
1472 blanks[nblanks].offset = pkt->savedpos;
1473 blanks[nblanks].type = PKTLOG_BLANK;
1474 ssh_pkt_getstring(pkt, &str, &slen);
1476 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1482 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1483 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1484 pkt->body, pkt->length, nblanks, blanks,
1485 &ssh->v2_outgoing_sequence);
1488 * Undo the above adjustment of pkt->length, to put the packet
1489 * back in the state we found it.
1491 pkt->length += (pkt->body - pkt->data);
1494 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1496 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1498 crBegin(ssh->ssh2_rdpkt_crstate);
1500 st->pktin = ssh_new_packet();
1502 st->pktin->type = 0;
1503 st->pktin->length = 0;
1505 st->cipherblk = ssh->sccipher->blksize;
1508 if (st->cipherblk < 8)
1510 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1512 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1515 * When dealing with a CBC-mode cipher, we want to avoid the
1516 * possibility of an attacker's tweaking the ciphertext stream
1517 * so as to cause us to feed the same block to the block
1518 * cipher more than once and thus leak information
1519 * (VU#958563). The way we do this is not to take any
1520 * decisions on the basis of anything we've decrypted until
1521 * we've verified it with a MAC. That includes the packet
1522 * length, so we just read data and check the MAC repeatedly,
1523 * and when the MAC passes, see if the length we've got is
1527 /* May as well allocate the whole lot now. */
1528 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1531 /* Read an amount corresponding to the MAC. */
1532 for (st->i = 0; st->i < st->maclen; st->i++) {
1533 while ((*datalen) == 0)
1535 st->pktin->data[st->i] = *(*data)++;
1541 unsigned char seq[4];
1542 ssh->scmac->start(ssh->sc_mac_ctx);
1543 PUT_32BIT(seq, st->incoming_sequence);
1544 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1547 for (;;) { /* Once around this loop per cipher block. */
1548 /* Read another cipher-block's worth, and tack it onto the end. */
1549 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1550 while ((*datalen) == 0)
1552 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1555 /* Decrypt one more block (a little further back in the stream). */
1556 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1557 st->pktin->data + st->packetlen,
1559 /* Feed that block to the MAC. */
1560 ssh->scmac->bytes(ssh->sc_mac_ctx,
1561 st->pktin->data + st->packetlen, st->cipherblk);
1562 st->packetlen += st->cipherblk;
1563 /* See if that gives us a valid packet. */
1564 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1565 st->pktin->data + st->packetlen) &&
1566 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1569 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1570 bombout(("No valid incoming packet found"));
1571 ssh_free_packet(st->pktin);
1575 st->pktin->maxlen = st->packetlen + st->maclen;
1576 st->pktin->data = sresize(st->pktin->data,
1577 st->pktin->maxlen + APIEXTRA,
1580 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1583 * Acquire and decrypt the first block of the packet. This will
1584 * contain the length and padding details.
1586 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1587 while ((*datalen) == 0)
1589 st->pktin->data[st->i] = *(*data)++;
1594 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1595 st->pktin->data, st->cipherblk);
1598 * Now get the length figure.
1600 st->len = toint(GET_32BIT(st->pktin->data));
1603 * _Completely_ silly lengths should be stomped on before they
1604 * do us any more damage.
1606 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1607 (st->len + 4) % st->cipherblk != 0) {
1608 bombout(("Incoming packet was garbled on decryption"));
1609 ssh_free_packet(st->pktin);
1614 * So now we can work out the total packet length.
1616 st->packetlen = st->len + 4;
1619 * Allocate memory for the rest of the packet.
1621 st->pktin->maxlen = st->packetlen + st->maclen;
1622 st->pktin->data = sresize(st->pktin->data,
1623 st->pktin->maxlen + APIEXTRA,
1627 * Read and decrypt the remainder of the packet.
1629 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1631 while ((*datalen) == 0)
1633 st->pktin->data[st->i] = *(*data)++;
1636 /* Decrypt everything _except_ the MAC. */
1638 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1639 st->pktin->data + st->cipherblk,
1640 st->packetlen - st->cipherblk);
1646 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1647 st->len + 4, st->incoming_sequence)) {
1648 bombout(("Incorrect MAC received on packet"));
1649 ssh_free_packet(st->pktin);
1653 /* Get and sanity-check the amount of random padding. */
1654 st->pad = st->pktin->data[4];
1655 if (st->pad < 4 || st->len - st->pad < 1) {
1656 bombout(("Invalid padding length on received packet"));
1657 ssh_free_packet(st->pktin);
1661 * This enables us to deduce the payload length.
1663 st->payload = st->len - st->pad - 1;
1665 st->pktin->length = st->payload + 5;
1666 st->pktin->encrypted_len = st->packetlen;
1668 st->pktin->sequence = st->incoming_sequence++;
1671 * Decompress packet payload.
1674 unsigned char *newpayload;
1677 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1678 st->pktin->data + 5, st->pktin->length - 5,
1679 &newpayload, &newlen)) {
1680 if (st->pktin->maxlen < newlen + 5) {
1681 st->pktin->maxlen = newlen + 5;
1682 st->pktin->data = sresize(st->pktin->data,
1683 st->pktin->maxlen + APIEXTRA,
1686 st->pktin->length = 5 + newlen;
1687 memcpy(st->pktin->data + 5, newpayload, newlen);
1693 * pktin->body and pktin->length should identify the semantic
1694 * content of the packet, excluding the initial type byte.
1696 st->pktin->type = st->pktin->data[5];
1697 st->pktin->body = st->pktin->data + 6;
1698 st->pktin->length = st->packetlen - 6 - st->pad;
1699 assert(st->pktin->length >= 0); /* one last double-check */
1702 ssh2_log_incoming_packet(ssh, st->pktin);
1704 st->pktin->savedpos = 0;
1706 crFinish(st->pktin);
1709 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1711 int pad, biglen, i, pktoffs;
1715 * XXX various versions of SC (including 8.8.4) screw up the
1716 * register allocation in this function and use the same register
1717 * (D6) for len and as a temporary, with predictable results. The
1718 * following sledgehammer prevents this.
1725 ssh1_log_outgoing_packet(ssh, pkt);
1727 if (ssh->v1_compressing) {
1728 unsigned char *compblk;
1730 zlib_compress_block(ssh->cs_comp_ctx,
1731 pkt->data + 12, pkt->length - 12,
1732 &compblk, &complen);
1733 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1734 memcpy(pkt->data + 12, compblk, complen);
1736 pkt->length = complen + 12;
1739 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1741 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1742 pad = 8 - (len % 8);
1744 biglen = len + pad; /* len(padding+type+data+CRC) */
1746 for (i = pktoffs; i < 4+8; i++)
1747 pkt->data[i] = random_byte();
1748 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1749 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1750 PUT_32BIT(pkt->data + pktoffs, len);
1753 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1754 pkt->data + pktoffs + 4, biglen);
1756 if (offset_p) *offset_p = pktoffs;
1757 return biglen + 4; /* len(length+padding+type+data+CRC) */
1760 static int s_write(Ssh ssh, void *data, int len)
1763 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1765 return sk_write(ssh->s, (char *)data, len);
1768 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1770 int len, backlog, offset;
1771 len = s_wrpkt_prepare(ssh, pkt, &offset);
1772 backlog = s_write(ssh, pkt->data + offset, len);
1773 if (backlog > SSH_MAX_BACKLOG)
1774 ssh_throttle_all(ssh, 1, backlog);
1775 ssh_free_packet(pkt);
1778 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1781 len = s_wrpkt_prepare(ssh, pkt, &offset);
1782 if (ssh->deferred_len + len > ssh->deferred_size) {
1783 ssh->deferred_size = ssh->deferred_len + len + 128;
1784 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1788 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1789 pkt->data + offset, len);
1790 ssh->deferred_len += len;
1791 ssh_free_packet(pkt);
1795 * Construct a SSH-1 packet with the specified contents.
1796 * (This all-at-once interface used to be the only one, but now SSH-1
1797 * packets can also be constructed incrementally.)
1799 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1805 pkt = ssh1_pkt_init(pkttype);
1807 while ((argtype = va_arg(ap, int)) != PKT_END) {
1808 unsigned char *argp, argchar;
1810 unsigned long argint;
1813 /* Actual fields in the packet */
1815 argint = va_arg(ap, int);
1816 ssh_pkt_adduint32(pkt, argint);
1819 argchar = (unsigned char) va_arg(ap, int);
1820 ssh_pkt_addbyte(pkt, argchar);
1823 argp = va_arg(ap, unsigned char *);
1824 arglen = va_arg(ap, int);
1825 ssh_pkt_adddata(pkt, argp, arglen);
1828 sargp = va_arg(ap, char *);
1829 ssh_pkt_addstring(pkt, sargp);
1832 bn = va_arg(ap, Bignum);
1833 ssh1_pkt_addmp(pkt, bn);
1841 static void send_packet(Ssh ssh, int pkttype, ...)
1845 va_start(ap, pkttype);
1846 pkt = construct_packet(ssh, pkttype, ap);
1851 static void defer_packet(Ssh ssh, int pkttype, ...)
1855 va_start(ap, pkttype);
1856 pkt = construct_packet(ssh, pkttype, ap);
1858 s_wrpkt_defer(ssh, pkt);
1861 static int ssh_versioncmp(char *a, char *b)
1864 unsigned long av, bv;
1866 av = strtoul(a, &ae, 10);
1867 bv = strtoul(b, &be, 10);
1869 return (av < bv ? -1 : +1);
1874 av = strtoul(ae, &ae, 10);
1875 bv = strtoul(be, &be, 10);
1877 return (av < bv ? -1 : +1);
1882 * Utility routines for putting an SSH-protocol `string' and
1883 * `uint32' into a hash state.
1885 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1887 unsigned char lenblk[4];
1888 PUT_32BIT(lenblk, len);
1889 h->bytes(s, lenblk, 4);
1890 h->bytes(s, str, len);
1893 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1895 unsigned char intblk[4];
1896 PUT_32BIT(intblk, i);
1897 h->bytes(s, intblk, 4);
1901 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1903 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1905 if (pkt->maxlen < length) {
1906 unsigned char *body = pkt->body;
1907 int offset = body ? body - pkt->data : 0;
1908 pkt->maxlen = length + 256;
1909 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1910 if (body) pkt->body = pkt->data + offset;
1913 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
1916 ssh_pkt_ensure(pkt, pkt->length);
1917 memcpy(pkt->data + pkt->length - len, data, len);
1919 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1921 ssh_pkt_adddata(pkt, &byte, 1);
1923 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1925 ssh_pkt_adddata(pkt, &value, 1);
1927 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1930 PUT_32BIT(x, value);
1931 ssh_pkt_adddata(pkt, x, 4);
1933 static void ssh_pkt_addstring_start(struct Packet *pkt)
1935 ssh_pkt_adduint32(pkt, 0);
1936 pkt->savedpos = pkt->length;
1938 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
1940 ssh_pkt_adddata(pkt, data, strlen(data));
1941 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1943 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
1946 ssh_pkt_adddata(pkt, data, len);
1947 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1949 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
1951 ssh_pkt_addstring_start(pkt);
1952 ssh_pkt_addstring_str(pkt, data);
1954 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1956 int len = ssh1_bignum_length(b);
1957 unsigned char *data = snewn(len, unsigned char);
1958 (void) ssh1_write_bignum(data, b);
1959 ssh_pkt_adddata(pkt, data, len);
1962 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1965 int i, n = (bignum_bitcount(b) + 7) / 8;
1966 p = snewn(n + 1, unsigned char);
1968 for (i = 1; i <= n; i++)
1969 p[i] = bignum_byte(b, n - i);
1971 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1973 memmove(p, p + i, n + 1 - i);
1977 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1981 p = ssh2_mpint_fmt(b, &len);
1982 ssh_pkt_addstring_start(pkt);
1983 ssh_pkt_addstring_data(pkt, (char *)p, len);
1987 static struct Packet *ssh1_pkt_init(int pkt_type)
1989 struct Packet *pkt = ssh_new_packet();
1990 pkt->length = 4 + 8; /* space for length + max padding */
1991 ssh_pkt_addbyte(pkt, pkt_type);
1992 pkt->body = pkt->data + pkt->length;
1993 pkt->type = pkt_type;
1997 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1998 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1999 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2000 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2001 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2002 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2003 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2004 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2005 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2007 static struct Packet *ssh2_pkt_init(int pkt_type)
2009 struct Packet *pkt = ssh_new_packet();
2010 pkt->length = 5; /* space for packet length + padding length */
2012 pkt->type = pkt_type;
2013 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2014 pkt->body = pkt->data + pkt->length; /* after packet type */
2019 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2020 * put the MAC on it. Final packet, ready to be sent, is stored in
2021 * pkt->data. Total length is returned.
2023 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2025 int cipherblk, maclen, padding, i;
2028 ssh2_log_outgoing_packet(ssh, pkt);
2031 * Compress packet payload.
2034 unsigned char *newpayload;
2037 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2039 &newpayload, &newlen)) {
2041 ssh2_pkt_adddata(pkt, newpayload, newlen);
2047 * Add padding. At least four bytes, and must also bring total
2048 * length (minus MAC) up to a multiple of the block size.
2049 * If pkt->forcepad is set, make sure the packet is at least that size
2052 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2053 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2055 if (pkt->length + padding < pkt->forcepad)
2056 padding = pkt->forcepad - pkt->length;
2058 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2059 assert(padding <= 255);
2060 maclen = ssh->csmac ? ssh->csmac->len : 0;
2061 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2062 pkt->data[4] = padding;
2063 for (i = 0; i < padding; i++)
2064 pkt->data[pkt->length + i] = random_byte();
2065 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2067 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2068 pkt->length + padding,
2069 ssh->v2_outgoing_sequence);
2070 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2073 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2074 pkt->data, pkt->length + padding);
2076 pkt->encrypted_len = pkt->length + padding;
2078 /* Ready-to-send packet starts at pkt->data. We return length. */
2079 return pkt->length + padding + maclen;
2083 * Routines called from the main SSH code to send packets. There
2084 * are quite a few of these, because we have two separate
2085 * mechanisms for delaying the sending of packets:
2087 * - In order to send an IGNORE message and a password message in
2088 * a single fixed-length blob, we require the ability to
2089 * concatenate the encrypted forms of those two packets _into_ a
2090 * single blob and then pass it to our <network.h> transport
2091 * layer in one go. Hence, there's a deferment mechanism which
2092 * works after packet encryption.
2094 * - In order to avoid sending any connection-layer messages
2095 * during repeat key exchange, we have to queue up any such
2096 * outgoing messages _before_ they are encrypted (and in
2097 * particular before they're allocated sequence numbers), and
2098 * then send them once we've finished.
2100 * I call these mechanisms `defer' and `queue' respectively, so as
2101 * to distinguish them reasonably easily.
2103 * The functions send_noqueue() and defer_noqueue() free the packet
2104 * structure they are passed. Every outgoing packet goes through
2105 * precisely one of these functions in its life; packets passed to
2106 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2107 * these or get queued, and then when the queue is later emptied
2108 * the packets are all passed to defer_noqueue().
2110 * When using a CBC-mode cipher, it's necessary to ensure that an
2111 * attacker can't provide data to be encrypted using an IV that they
2112 * know. We ensure this by prefixing each packet that might contain
2113 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2114 * mechanism, so in this case send_noqueue() ends up redirecting to
2115 * defer_noqueue(). If you don't like this inefficiency, don't use
2119 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2120 static void ssh_pkt_defersend(Ssh);
2123 * Send an SSH-2 packet immediately, without queuing or deferring.
2125 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2129 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2130 /* We need to send two packets, so use the deferral mechanism. */
2131 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2132 ssh_pkt_defersend(ssh);
2135 len = ssh2_pkt_construct(ssh, pkt);
2136 backlog = s_write(ssh, pkt->data, len);
2137 if (backlog > SSH_MAX_BACKLOG)
2138 ssh_throttle_all(ssh, 1, backlog);
2140 ssh->outgoing_data_size += pkt->encrypted_len;
2141 if (!ssh->kex_in_progress &&
2142 ssh->max_data_size != 0 &&
2143 ssh->outgoing_data_size > ssh->max_data_size)
2144 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2146 ssh_free_packet(pkt);
2150 * Defer an SSH-2 packet.
2152 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2155 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2156 ssh->deferred_len == 0 && !noignore &&
2157 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2159 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2160 * get encrypted with a known IV.
2162 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2163 ssh2_pkt_addstring_start(ipkt);
2164 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2166 len = ssh2_pkt_construct(ssh, pkt);
2167 if (ssh->deferred_len + len > ssh->deferred_size) {
2168 ssh->deferred_size = ssh->deferred_len + len + 128;
2169 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2173 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2174 ssh->deferred_len += len;
2175 ssh->deferred_data_size += pkt->encrypted_len;
2176 ssh_free_packet(pkt);
2180 * Queue an SSH-2 packet.
2182 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2184 assert(ssh->queueing);
2186 if (ssh->queuelen >= ssh->queuesize) {
2187 ssh->queuesize = ssh->queuelen + 32;
2188 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2191 ssh->queue[ssh->queuelen++] = pkt;
2195 * Either queue or send a packet, depending on whether queueing is
2198 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2201 ssh2_pkt_queue(ssh, pkt);
2203 ssh2_pkt_send_noqueue(ssh, pkt);
2207 * Either queue or defer a packet, depending on whether queueing is
2210 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2213 ssh2_pkt_queue(ssh, pkt);
2215 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2219 * Send the whole deferred data block constructed by
2220 * ssh2_pkt_defer() or SSH-1's defer_packet().
2222 * The expected use of the defer mechanism is that you call
2223 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2224 * not currently queueing, this simply sets up deferred_send_data
2225 * and then sends it. If we _are_ currently queueing, the calls to
2226 * ssh2_pkt_defer() put the deferred packets on to the queue
2227 * instead, and therefore ssh_pkt_defersend() has no deferred data
2228 * to send. Hence, there's no need to make it conditional on
2231 static void ssh_pkt_defersend(Ssh ssh)
2234 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2235 ssh->deferred_len = ssh->deferred_size = 0;
2236 sfree(ssh->deferred_send_data);
2237 ssh->deferred_send_data = NULL;
2238 if (backlog > SSH_MAX_BACKLOG)
2239 ssh_throttle_all(ssh, 1, backlog);
2241 ssh->outgoing_data_size += ssh->deferred_data_size;
2242 if (!ssh->kex_in_progress &&
2243 ssh->max_data_size != 0 &&
2244 ssh->outgoing_data_size > ssh->max_data_size)
2245 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2246 ssh->deferred_data_size = 0;
2250 * Send a packet whose length needs to be disguised (typically
2251 * passwords or keyboard-interactive responses).
2253 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2259 * The simplest way to do this is to adjust the
2260 * variable-length padding field in the outgoing packet.
2262 * Currently compiled out, because some Cisco SSH servers
2263 * don't like excessively padded packets (bah, why's it
2266 pkt->forcepad = padsize;
2267 ssh2_pkt_send(ssh, pkt);
2272 * If we can't do that, however, an alternative approach is
2273 * to use the pkt_defer mechanism to bundle the packet
2274 * tightly together with an SSH_MSG_IGNORE such that their
2275 * combined length is a constant. So first we construct the
2276 * final form of this packet and defer its sending.
2278 ssh2_pkt_defer(ssh, pkt);
2281 * Now construct an SSH_MSG_IGNORE which includes a string
2282 * that's an exact multiple of the cipher block size. (If
2283 * the cipher is NULL so that the block size is
2284 * unavailable, we don't do this trick at all, because we
2285 * gain nothing by it.)
2287 if (ssh->cscipher &&
2288 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2291 stringlen = (256 - ssh->deferred_len);
2292 stringlen += ssh->cscipher->blksize - 1;
2293 stringlen -= (stringlen % ssh->cscipher->blksize);
2296 * Temporarily disable actual compression, so we
2297 * can guarantee to get this string exactly the
2298 * length we want it. The compression-disabling
2299 * routine should return an integer indicating how
2300 * many bytes we should adjust our string length
2304 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2306 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2307 ssh2_pkt_addstring_start(pkt);
2308 for (i = 0; i < stringlen; i++) {
2309 char c = (char) random_byte();
2310 ssh2_pkt_addstring_data(pkt, &c, 1);
2312 ssh2_pkt_defer(ssh, pkt);
2314 ssh_pkt_defersend(ssh);
2319 * Send all queued SSH-2 packets. We send them by means of
2320 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2321 * packets that needed to be lumped together.
2323 static void ssh2_pkt_queuesend(Ssh ssh)
2327 assert(!ssh->queueing);
2329 for (i = 0; i < ssh->queuelen; i++)
2330 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2333 ssh_pkt_defersend(ssh);
2337 void bndebug(char *string, Bignum b)
2341 p = ssh2_mpint_fmt(b, &len);
2342 debug(("%s", string));
2343 for (i = 0; i < len; i++)
2344 debug((" %02x", p[i]));
2350 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2354 p = ssh2_mpint_fmt(b, &len);
2355 hash_string(h, s, p, len);
2360 * Packet decode functions for both SSH-1 and SSH-2.
2362 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2364 unsigned long value;
2365 if (pkt->length - pkt->savedpos < 4)
2366 return 0; /* arrgh, no way to decline (FIXME?) */
2367 value = GET_32BIT(pkt->body + pkt->savedpos);
2371 static int ssh2_pkt_getbool(struct Packet *pkt)
2373 unsigned long value;
2374 if (pkt->length - pkt->savedpos < 1)
2375 return 0; /* arrgh, no way to decline (FIXME?) */
2376 value = pkt->body[pkt->savedpos] != 0;
2380 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2385 if (pkt->length - pkt->savedpos < 4)
2387 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2392 if (pkt->length - pkt->savedpos < *length)
2394 *p = (char *)(pkt->body + pkt->savedpos);
2395 pkt->savedpos += *length;
2397 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2399 if (pkt->length - pkt->savedpos < length)
2401 pkt->savedpos += length;
2402 return pkt->body + (pkt->savedpos - length);
2404 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2405 unsigned char **keystr)
2409 j = makekey(pkt->body + pkt->savedpos,
2410 pkt->length - pkt->savedpos,
2417 assert(pkt->savedpos < pkt->length);
2421 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2426 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2427 pkt->length - pkt->savedpos, &b);
2435 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2441 ssh_pkt_getstring(pkt, &p, &length);
2446 b = bignum_from_bytes((unsigned char *)p, length);
2451 * Helper function to add an SSH-2 signature blob to a packet.
2452 * Expects to be shown the public key blob as well as the signature
2453 * blob. Normally works just like ssh2_pkt_addstring, but will
2454 * fiddle with the signature packet if necessary for
2455 * BUG_SSH2_RSA_PADDING.
2457 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2458 void *pkblob_v, int pkblob_len,
2459 void *sigblob_v, int sigblob_len)
2461 unsigned char *pkblob = (unsigned char *)pkblob_v;
2462 unsigned char *sigblob = (unsigned char *)sigblob_v;
2464 /* dmemdump(pkblob, pkblob_len); */
2465 /* dmemdump(sigblob, sigblob_len); */
2468 * See if this is in fact an ssh-rsa signature and a buggy
2469 * server; otherwise we can just do this the easy way.
2471 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2472 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2473 int pos, len, siglen;
2476 * Find the byte length of the modulus.
2479 pos = 4+7; /* skip over "ssh-rsa" */
2480 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2481 if (len < 0 || len > pkblob_len - pos - 4)
2483 pos += 4 + len; /* skip over exponent */
2484 if (pkblob_len - pos < 4)
2486 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2487 if (len < 0 || len > pkblob_len - pos - 4)
2489 pos += 4; /* find modulus itself */
2490 while (len > 0 && pkblob[pos] == 0)
2492 /* debug(("modulus length is %d\n", len)); */
2495 * Now find the signature integer.
2497 pos = 4+7; /* skip over "ssh-rsa" */
2498 if (sigblob_len < pos+4)
2500 siglen = toint(GET_32BIT(sigblob+pos));
2501 if (siglen != sigblob_len - pos - 4)
2503 /* debug(("signature length is %d\n", siglen)); */
2505 if (len != siglen) {
2506 unsigned char newlen[4];
2507 ssh2_pkt_addstring_start(pkt);
2508 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2509 /* dmemdump(sigblob, pos); */
2510 pos += 4; /* point to start of actual sig */
2511 PUT_32BIT(newlen, len);
2512 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2513 /* dmemdump(newlen, 4); */
2515 while (len-- > siglen) {
2516 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2517 /* dmemdump(newlen, 1); */
2519 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2520 /* dmemdump(sigblob+pos, siglen); */
2524 /* Otherwise fall through and do it the easy way. We also come
2525 * here as a fallback if we discover above that the key blob
2526 * is misformatted in some way. */
2530 ssh2_pkt_addstring_start(pkt);
2531 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2535 * Examine the remote side's version string and compare it against
2536 * a list of known buggy implementations.
2538 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2540 char *imp; /* pointer to implementation part */
2542 imp += strcspn(imp, "-");
2544 imp += strcspn(imp, "-");
2547 ssh->remote_bugs = 0;
2550 * General notes on server version strings:
2551 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2552 * here -- in particular, we've heard of one that's perfectly happy
2553 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2554 * so we can't distinguish them.
2556 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2557 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2558 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2559 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2560 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2561 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2563 * These versions don't support SSH1_MSG_IGNORE, so we have
2564 * to use a different defence against password length
2567 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2568 logevent("We believe remote version has SSH-1 ignore bug");
2571 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2572 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2573 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2575 * These versions need a plain password sent; they can't
2576 * handle having a null and a random length of data after
2579 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2580 logevent("We believe remote version needs a plain SSH-1 password");
2583 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2584 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2585 (!strcmp(imp, "Cisco-1.25")))) {
2587 * These versions apparently have no clue whatever about
2588 * RSA authentication and will panic and die if they see
2589 * an AUTH_RSA message.
2591 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2592 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2595 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2596 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2597 !wc_match("* VShell", imp) &&
2598 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2599 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2600 wc_match("2.1 *", imp)))) {
2602 * These versions have the HMAC bug.
2604 ssh->remote_bugs |= BUG_SSH2_HMAC;
2605 logevent("We believe remote version has SSH-2 HMAC bug");
2608 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2609 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2610 !wc_match("* VShell", imp) &&
2611 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2613 * These versions have the key-derivation bug (failing to
2614 * include the literal shared secret in the hashes that
2615 * generate the keys).
2617 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2618 logevent("We believe remote version has SSH-2 key-derivation bug");
2621 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2622 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2623 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2624 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2626 * These versions have the SSH-2 RSA padding bug.
2628 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2629 logevent("We believe remote version has SSH-2 RSA padding bug");
2632 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2633 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2634 wc_match("OpenSSH_2.[0-2]*", imp))) {
2636 * These versions have the SSH-2 session-ID bug in
2637 * public-key authentication.
2639 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2640 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2643 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2644 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2645 (wc_match("DigiSSH_2.0", imp) ||
2646 wc_match("OpenSSH_2.[0-4]*", imp) ||
2647 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2648 wc_match("Sun_SSH_1.0", imp) ||
2649 wc_match("Sun_SSH_1.0.1", imp) ||
2650 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2651 wc_match("WeOnlyDo-*", imp)))) {
2653 * These versions have the SSH-2 rekey bug.
2655 ssh->remote_bugs |= BUG_SSH2_REKEY;
2656 logevent("We believe remote version has SSH-2 rekey bug");
2659 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2660 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2661 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2662 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2664 * This version ignores our makpkt and needs to be throttled.
2666 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2667 logevent("We believe remote version ignores SSH-2 maximum packet size");
2670 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2672 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2673 * none detected automatically.
2675 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2676 logevent("We believe remote version has SSH-2 ignore bug");
2679 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2681 * Servers that don't support our winadj request for one
2682 * reason or another. Currently, none detected automatically.
2684 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2685 logevent("We believe remote version has winadj bug");
2690 * The `software version' part of an SSH version string is required
2691 * to contain no spaces or minus signs.
2693 static void ssh_fix_verstring(char *str)
2695 /* Eat "SSH-<protoversion>-". */
2696 assert(*str == 'S'); str++;
2697 assert(*str == 'S'); str++;
2698 assert(*str == 'H'); str++;
2699 assert(*str == '-'); str++;
2700 while (*str && *str != '-') str++;
2701 assert(*str == '-'); str++;
2703 /* Convert minus signs and spaces in the remaining string into
2706 if (*str == '-' || *str == ' ')
2713 * Send an appropriate SSH version string.
2715 static void ssh_send_verstring(Ssh ssh, char *svers)
2719 if (ssh->version == 2) {
2721 * Construct a v2 version string.
2723 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2726 * Construct a v1 version string.
2728 verstring = dupprintf("SSH-%s-%s\012",
2729 (ssh_versioncmp(svers, "1.5") <= 0 ?
2734 ssh_fix_verstring(verstring);
2736 if (ssh->version == 2) {
2739 * Record our version string.
2741 len = strcspn(verstring, "\015\012");
2742 ssh->v_c = snewn(len + 1, char);
2743 memcpy(ssh->v_c, verstring, len);
2747 logeventf(ssh, "We claim version: %.*s",
2748 strcspn(verstring, "\015\012"), verstring);
2749 s_write(ssh, verstring, strlen(verstring));
2753 static int do_ssh_init(Ssh ssh, unsigned char c)
2755 struct do_ssh_init_state {
2764 crState(do_ssh_init_state);
2768 /* Search for a line beginning with the string "SSH-" in the input. */
2770 if (c != 'S') goto no;
2772 if (c != 'S') goto no;
2774 if (c != 'H') goto no;
2776 if (c != '-') goto no;
2785 s->vstring = snewn(s->vstrsize, char);
2786 strcpy(s->vstring, "SSH-");
2790 crReturn(1); /* get another char */
2791 if (s->vslen >= s->vstrsize - 1) {
2793 s->vstring = sresize(s->vstring, s->vstrsize, char);
2795 s->vstring[s->vslen++] = c;
2798 s->version[s->i] = '\0';
2800 } else if (s->i < sizeof(s->version) - 1)
2801 s->version[s->i++] = c;
2802 } else if (c == '\012')
2806 ssh->agentfwd_enabled = FALSE;
2807 ssh->rdpkt2_state.incoming_sequence = 0;
2809 s->vstring[s->vslen] = 0;
2810 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2811 logeventf(ssh, "Server version: %s", s->vstring);
2812 ssh_detect_bugs(ssh, s->vstring);
2815 * Decide which SSH protocol version to support.
2818 /* Anything strictly below "2.0" means protocol 1 is supported. */
2819 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2820 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2821 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2823 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2824 bombout(("SSH protocol version 1 required by user but not provided by server"));
2827 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2828 bombout(("SSH protocol version 2 required by user but not provided by server"));
2832 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2837 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2839 /* Send the version string, if we haven't already */
2840 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2841 ssh_send_verstring(ssh, s->version);
2843 if (ssh->version == 2) {
2846 * Record their version string.
2848 len = strcspn(s->vstring, "\015\012");
2849 ssh->v_s = snewn(len + 1, char);
2850 memcpy(ssh->v_s, s->vstring, len);
2854 * Initialise SSH-2 protocol.
2856 ssh->protocol = ssh2_protocol;
2857 ssh2_protocol_setup(ssh);
2858 ssh->s_rdpkt = ssh2_rdpkt;
2861 * Initialise SSH-1 protocol.
2863 ssh->protocol = ssh1_protocol;
2864 ssh1_protocol_setup(ssh);
2865 ssh->s_rdpkt = ssh1_rdpkt;
2867 if (ssh->version == 2)
2868 do_ssh2_transport(ssh, NULL, -1, NULL);
2870 update_specials_menu(ssh->frontend);
2871 ssh->state = SSH_STATE_BEFORE_SIZE;
2872 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2879 static void ssh_process_incoming_data(Ssh ssh,
2880 unsigned char **data, int *datalen)
2882 struct Packet *pktin;
2884 pktin = ssh->s_rdpkt(ssh, data, datalen);
2886 ssh->protocol(ssh, NULL, 0, pktin);
2887 ssh_free_packet(pktin);
2891 static void ssh_queue_incoming_data(Ssh ssh,
2892 unsigned char **data, int *datalen)
2894 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2899 static void ssh_process_queued_incoming_data(Ssh ssh)
2902 unsigned char *data;
2905 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2906 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2910 while (!ssh->frozen && len > 0)
2911 ssh_process_incoming_data(ssh, &data, &len);
2914 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2918 static void ssh_set_frozen(Ssh ssh, int frozen)
2921 sk_set_frozen(ssh->s, frozen);
2922 ssh->frozen = frozen;
2925 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2927 /* Log raw data, if we're in that mode. */
2929 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2932 crBegin(ssh->ssh_gotdata_crstate);
2935 * To begin with, feed the characters one by one to the
2936 * protocol initialisation / selection function do_ssh_init().
2937 * When that returns 0, we're done with the initial greeting
2938 * exchange and can move on to packet discipline.
2941 int ret; /* need not be kept across crReturn */
2943 crReturnV; /* more data please */
2944 ret = do_ssh_init(ssh, *data);
2952 * We emerge from that loop when the initial negotiation is
2953 * over and we have selected an s_rdpkt function. Now pass
2954 * everything to s_rdpkt, and then pass the resulting packets
2955 * to the proper protocol handler.
2959 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2961 ssh_queue_incoming_data(ssh, &data, &datalen);
2962 /* This uses up all data and cannot cause anything interesting
2963 * to happen; indeed, for anything to happen at all, we must
2964 * return, so break out. */
2966 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2967 /* This uses up some or all data, and may freeze the
2969 ssh_process_queued_incoming_data(ssh);
2971 /* This uses up some or all data, and may freeze the
2973 ssh_process_incoming_data(ssh, &data, &datalen);
2975 /* FIXME this is probably EBW. */
2976 if (ssh->state == SSH_STATE_CLOSED)
2979 /* We're out of data. Go and get some more. */
2985 static int ssh_do_close(Ssh ssh, int notify_exit)
2988 struct ssh_channel *c;
2990 ssh->state = SSH_STATE_CLOSED;
2991 expire_timer_context(ssh);
2996 notify_remote_exit(ssh->frontend);
3001 * Now we must shut down any port- and X-forwarded channels going
3002 * through this connection.
3004 if (ssh->channels) {
3005 while (NULL != (c = index234(ssh->channels, 0))) {
3008 x11_close(c->u.x11.s);
3011 case CHAN_SOCKDATA_DORMANT:
3012 pfd_close(c->u.pfd.s);
3015 del234(ssh->channels, c); /* moving next one to index 0 */
3016 if (ssh->version == 2)
3017 bufchain_clear(&c->v.v2.outbuffer);
3022 * Go through port-forwardings, and close any associated
3023 * listening sockets.
3025 if (ssh->portfwds) {
3026 struct ssh_portfwd *pf;
3027 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3028 /* Dispose of any listening socket. */
3030 pfd_terminate(pf->local);
3031 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3034 freetree234(ssh->portfwds);
3035 ssh->portfwds = NULL;
3041 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
3042 const char *error_msg, int error_code)
3044 Ssh ssh = (Ssh) plug;
3045 char addrbuf[256], *msg;
3047 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3050 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3052 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3058 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3061 Ssh ssh = (Ssh) plug;
3062 int need_notify = ssh_do_close(ssh, FALSE);
3065 if (!ssh->close_expected)
3066 error_msg = "Server unexpectedly closed network connection";
3068 error_msg = "Server closed network connection";
3071 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3075 notify_remote_exit(ssh->frontend);
3078 logevent(error_msg);
3079 if (!ssh->close_expected || !ssh->clean_exit)
3080 connection_fatal(ssh->frontend, "%s", error_msg);
3084 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3086 Ssh ssh = (Ssh) plug;
3087 ssh_gotdata(ssh, (unsigned char *)data, len);
3088 if (ssh->state == SSH_STATE_CLOSED) {
3089 ssh_do_close(ssh, TRUE);
3095 static void ssh_sent(Plug plug, int bufsize)
3097 Ssh ssh = (Ssh) plug;
3099 * If the send backlog on the SSH socket itself clears, we
3100 * should unthrottle the whole world if it was throttled.
3102 if (bufsize < SSH_MAX_BACKLOG)
3103 ssh_throttle_all(ssh, 0, bufsize);
3107 * Connect to specified host and port.
3108 * Returns an error message, or NULL on success.
3109 * Also places the canonical host name into `realhost'. It must be
3110 * freed by the caller.
3112 static const char *connect_to_host(Ssh ssh, char *host, int port,
3113 char **realhost, int nodelay, int keepalive)
3115 static const struct plug_function_table fn_table = {
3126 int addressfamily, sshprot;
3128 loghost = conf_get_str(ssh->conf, CONF_loghost);
3132 ssh->savedhost = dupstr(loghost);
3133 ssh->savedport = 22; /* default ssh port */
3136 * A colon suffix on savedhost also lets us affect
3139 * (FIXME: do something about IPv6 address literals here.)
3141 colon = strrchr(ssh->savedhost, ':');
3145 ssh->savedport = atoi(colon);
3148 ssh->savedhost = dupstr(host);
3150 port = 22; /* default ssh port */
3151 ssh->savedport = port;
3157 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3158 logeventf(ssh, "Looking up host \"%s\"%s", host,
3159 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3160 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3161 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3162 if ((err = sk_addr_error(addr)) != NULL) {
3166 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3171 ssh->fn = &fn_table;
3172 ssh->s = new_connection(addr, *realhost, port,
3173 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
3174 if ((err = sk_socket_error(ssh->s)) != NULL) {
3176 notify_remote_exit(ssh->frontend);
3181 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3182 * send the version string too.
3184 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3189 ssh_send_verstring(ssh, NULL);
3193 * loghost, if configured, overrides realhost.
3197 *realhost = dupstr(loghost);
3204 * Throttle or unthrottle the SSH connection.
3206 static void ssh_throttle_conn(Ssh ssh, int adjust)
3208 int old_count = ssh->conn_throttle_count;
3209 ssh->conn_throttle_count += adjust;
3210 assert(ssh->conn_throttle_count >= 0);
3211 if (ssh->conn_throttle_count && !old_count) {
3212 ssh_set_frozen(ssh, 1);
3213 } else if (!ssh->conn_throttle_count && old_count) {
3214 ssh_set_frozen(ssh, 0);
3219 * Throttle or unthrottle _all_ local data streams (for when sends
3220 * on the SSH connection itself back up).
3222 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3225 struct ssh_channel *c;
3227 if (enable == ssh->throttled_all)
3229 ssh->throttled_all = enable;
3230 ssh->overall_bufsize = bufsize;
3233 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3235 case CHAN_MAINSESSION:
3237 * This is treated separately, outside the switch.
3241 x11_override_throttle(c->u.x11.s, enable);
3244 /* Agent channels require no buffer management. */
3247 pfd_override_throttle(c->u.pfd.s, enable);
3253 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3255 Ssh ssh = (Ssh) sshv;
3257 ssh->agent_response = reply;
3258 ssh->agent_response_len = replylen;
3260 if (ssh->version == 1)
3261 do_ssh1_login(ssh, NULL, -1, NULL);
3263 do_ssh2_authconn(ssh, NULL, -1, NULL);
3266 static void ssh_dialog_callback(void *sshv, int ret)
3268 Ssh ssh = (Ssh) sshv;
3270 ssh->user_response = ret;
3272 if (ssh->version == 1)
3273 do_ssh1_login(ssh, NULL, -1, NULL);
3275 do_ssh2_transport(ssh, NULL, -1, NULL);
3278 * This may have unfrozen the SSH connection, so do a
3281 ssh_process_queued_incoming_data(ssh);
3284 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3286 struct ssh_channel *c = (struct ssh_channel *)cv;
3288 void *sentreply = reply;
3290 c->u.a.outstanding_requests--;
3292 /* Fake SSH_AGENT_FAILURE. */
3293 sentreply = "\0\0\0\1\5";
3296 if (ssh->version == 2) {
3297 ssh2_add_channel_data(c, sentreply, replylen);
3300 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3301 PKT_INT, c->remoteid,
3303 PKT_DATA, sentreply, replylen,
3309 * If we've already seen an incoming EOF but haven't sent an
3310 * outgoing one, this may be the moment to send it.
3312 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3313 sshfwd_write_eof(c);
3317 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3318 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3319 * => log `wire_reason'.
3321 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3322 int code, int clean_exit)
3326 client_reason = wire_reason;
3328 error = dupprintf("Disconnected: %s", client_reason);
3330 error = dupstr("Disconnected");
3332 if (ssh->version == 1) {
3333 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3335 } else if (ssh->version == 2) {
3336 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3337 ssh2_pkt_adduint32(pktout, code);
3338 ssh2_pkt_addstring(pktout, wire_reason);
3339 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3340 ssh2_pkt_send_noqueue(ssh, pktout);
3343 ssh->close_expected = TRUE;
3344 ssh->clean_exit = clean_exit;
3345 ssh_closing((Plug)ssh, error, 0, 0);
3350 * Handle the key exchange and user authentication phases.
3352 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3353 struct Packet *pktin)
3356 unsigned char cookie[8], *ptr;
3357 struct MD5Context md5c;
3358 struct do_ssh1_login_state {
3361 unsigned char *rsabuf, *keystr1, *keystr2;
3362 unsigned long supported_ciphers_mask, supported_auths_mask;
3363 int tried_publickey, tried_agent;
3364 int tis_auth_refused, ccard_auth_refused;
3365 unsigned char session_id[16];
3367 void *publickey_blob;
3368 int publickey_bloblen;
3369 char *publickey_comment;
3370 int publickey_encrypted;
3371 prompts_t *cur_prompt;
3374 unsigned char request[5], *response, *p;
3384 struct RSAKey servkey, hostkey;
3386 crState(do_ssh1_login_state);
3393 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3394 bombout(("Public key packet not received"));
3398 logevent("Received public keys");
3400 ptr = ssh_pkt_getdata(pktin, 8);
3402 bombout(("SSH-1 public key packet stopped before random cookie"));
3405 memcpy(cookie, ptr, 8);
3407 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3408 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3409 bombout(("Failed to read SSH-1 public keys from public key packet"));
3414 * Log the host key fingerprint.
3418 logevent("Host key fingerprint is:");
3419 strcpy(logmsg, " ");
3420 s->hostkey.comment = NULL;
3421 rsa_fingerprint(logmsg + strlen(logmsg),
3422 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3426 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3427 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3428 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3429 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3430 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3432 ssh->v1_local_protoflags =
3433 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3434 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3437 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3438 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3439 MD5Update(&md5c, cookie, 8);
3440 MD5Final(s->session_id, &md5c);
3442 for (i = 0; i < 32; i++)
3443 ssh->session_key[i] = random_byte();
3446 * Verify that the `bits' and `bytes' parameters match.
3448 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3449 s->servkey.bits > s->servkey.bytes * 8) {
3450 bombout(("SSH-1 public keys were badly formatted"));
3454 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3455 s->hostkey.bytes : s->servkey.bytes);
3457 s->rsabuf = snewn(s->len, unsigned char);
3460 * Verify the host key.
3464 * First format the key into a string.
3466 int len = rsastr_len(&s->hostkey);
3467 char fingerprint[100];
3468 char *keystr = snewn(len, char);
3469 rsastr_fmt(keystr, &s->hostkey);
3470 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3472 ssh_set_frozen(ssh, 1);
3473 s->dlgret = verify_ssh_host_key(ssh->frontend,
3474 ssh->savedhost, ssh->savedport,
3475 "rsa", keystr, fingerprint,
3476 ssh_dialog_callback, ssh);
3478 if (s->dlgret < 0) {
3482 bombout(("Unexpected data from server while waiting"
3483 " for user host key response"));
3486 } while (pktin || inlen > 0);
3487 s->dlgret = ssh->user_response;
3489 ssh_set_frozen(ssh, 0);
3491 if (s->dlgret == 0) {
3492 ssh_disconnect(ssh, "User aborted at host key verification",
3498 for (i = 0; i < 32; i++) {
3499 s->rsabuf[i] = ssh->session_key[i];
3501 s->rsabuf[i] ^= s->session_id[i];
3504 if (s->hostkey.bytes > s->servkey.bytes) {
3505 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3507 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3509 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3511 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3514 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3518 logevent("Encrypted session key");
3521 int cipher_chosen = 0, warn = 0;
3522 char *cipher_string = NULL;
3524 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3525 int next_cipher = conf_get_int_int(ssh->conf,
3526 CONF_ssh_cipherlist, i);
3527 if (next_cipher == CIPHER_WARN) {
3528 /* If/when we choose a cipher, warn about it */
3530 } else if (next_cipher == CIPHER_AES) {
3531 /* XXX Probably don't need to mention this. */
3532 logevent("AES not supported in SSH-1, skipping");
3534 switch (next_cipher) {
3535 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3536 cipher_string = "3DES"; break;
3537 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3538 cipher_string = "Blowfish"; break;
3539 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3540 cipher_string = "single-DES"; break;
3542 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3546 if (!cipher_chosen) {
3547 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3548 bombout(("Server violates SSH-1 protocol by not "
3549 "supporting 3DES encryption"));
3551 /* shouldn't happen */
3552 bombout(("No supported ciphers found"));
3556 /* Warn about chosen cipher if necessary. */
3558 ssh_set_frozen(ssh, 1);
3559 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3560 ssh_dialog_callback, ssh);
3561 if (s->dlgret < 0) {
3565 bombout(("Unexpected data from server while waiting"
3566 " for user response"));
3569 } while (pktin || inlen > 0);
3570 s->dlgret = ssh->user_response;
3572 ssh_set_frozen(ssh, 0);
3573 if (s->dlgret == 0) {
3574 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3581 switch (s->cipher_type) {
3582 case SSH_CIPHER_3DES:
3583 logevent("Using 3DES encryption");
3585 case SSH_CIPHER_DES:
3586 logevent("Using single-DES encryption");
3588 case SSH_CIPHER_BLOWFISH:
3589 logevent("Using Blowfish encryption");
3593 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3594 PKT_CHAR, s->cipher_type,
3595 PKT_DATA, cookie, 8,
3596 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3597 PKT_DATA, s->rsabuf, s->len,
3598 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3600 logevent("Trying to enable encryption...");
3604 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3605 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3607 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3608 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3609 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3611 ssh->crcda_ctx = crcda_make_context();
3612 logevent("Installing CRC compensation attack detector");
3614 if (s->servkey.modulus) {
3615 sfree(s->servkey.modulus);
3616 s->servkey.modulus = NULL;
3618 if (s->servkey.exponent) {
3619 sfree(s->servkey.exponent);
3620 s->servkey.exponent = NULL;
3622 if (s->hostkey.modulus) {
3623 sfree(s->hostkey.modulus);
3624 s->hostkey.modulus = NULL;
3626 if (s->hostkey.exponent) {
3627 sfree(s->hostkey.exponent);
3628 s->hostkey.exponent = NULL;
3632 if (pktin->type != SSH1_SMSG_SUCCESS) {
3633 bombout(("Encryption not successfully enabled"));
3637 logevent("Successfully started encryption");
3639 fflush(stdout); /* FIXME eh? */
3641 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3642 int ret; /* need not be kept over crReturn */
3643 s->cur_prompt = new_prompts(ssh->frontend);
3644 s->cur_prompt->to_server = TRUE;
3645 s->cur_prompt->name = dupstr("SSH login name");
3646 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3647 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3650 crWaitUntil(!pktin);
3651 ret = get_userpass_input(s->cur_prompt, in, inlen);
3656 * Failed to get a username. Terminate.
3658 free_prompts(s->cur_prompt);
3659 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3662 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3663 free_prompts(s->cur_prompt);
3666 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3668 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3670 if (flags & FLAG_INTERACTIVE &&
3671 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3672 c_write_str(ssh, userlog);
3673 c_write_str(ssh, "\r\n");
3681 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3682 /* We must not attempt PK auth. Pretend we've already tried it. */
3683 s->tried_publickey = s->tried_agent = 1;
3685 s->tried_publickey = s->tried_agent = 0;
3687 s->tis_auth_refused = s->ccard_auth_refused = 0;
3689 * Load the public half of any configured keyfile for later use.
3691 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3692 if (!filename_is_null(s->keyfile)) {
3694 logeventf(ssh, "Reading private key file \"%.150s\"",
3695 filename_to_str(s->keyfile));
3696 keytype = key_type(s->keyfile);
3697 if (keytype == SSH_KEYTYPE_SSH1) {
3699 if (rsakey_pubblob(s->keyfile,
3700 &s->publickey_blob, &s->publickey_bloblen,
3701 &s->publickey_comment, &error)) {
3702 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
3706 logeventf(ssh, "Unable to load private key (%s)", error);
3707 msgbuf = dupprintf("Unable to load private key file "
3708 "\"%.150s\" (%s)\r\n",
3709 filename_to_str(s->keyfile),
3711 c_write_str(ssh, msgbuf);
3713 s->publickey_blob = NULL;
3717 logeventf(ssh, "Unable to use this key file (%s)",
3718 key_type_to_str(keytype));
3719 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3721 filename_to_str(s->keyfile),
3722 key_type_to_str(keytype));
3723 c_write_str(ssh, msgbuf);
3725 s->publickey_blob = NULL;
3728 s->publickey_blob = NULL;
3730 while (pktin->type == SSH1_SMSG_FAILURE) {
3731 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3733 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
3735 * Attempt RSA authentication using Pageant.
3741 logevent("Pageant is running. Requesting keys.");
3743 /* Request the keys held by the agent. */
3744 PUT_32BIT(s->request, 1);
3745 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3746 if (!agent_query(s->request, 5, &r, &s->responselen,
3747 ssh_agent_callback, ssh)) {
3751 bombout(("Unexpected data from server while waiting"
3752 " for agent response"));
3755 } while (pktin || inlen > 0);
3756 r = ssh->agent_response;
3757 s->responselen = ssh->agent_response_len;
3759 s->response = (unsigned char *) r;
3760 if (s->response && s->responselen >= 5 &&
3761 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3762 s->p = s->response + 5;
3763 s->nkeys = toint(GET_32BIT(s->p));
3765 logeventf(ssh, "Pageant reported negative key count %d",
3770 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3771 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3772 unsigned char *pkblob = s->p;
3776 do { /* do while (0) to make breaking easy */
3777 n = ssh1_read_bignum
3778 (s->p, toint(s->responselen-(s->p-s->response)),
3783 n = ssh1_read_bignum
3784 (s->p, toint(s->responselen-(s->p-s->response)),
3789 if (s->responselen - (s->p-s->response) < 4)
3791 s->commentlen = toint(GET_32BIT(s->p));
3793 if (s->commentlen < 0 ||
3794 toint(s->responselen - (s->p-s->response)) <
3797 s->commentp = (char *)s->p;
3798 s->p += s->commentlen;
3802 logevent("Pageant key list packet was truncated");
3806 if (s->publickey_blob) {
3807 if (!memcmp(pkblob, s->publickey_blob,
3808 s->publickey_bloblen)) {
3809 logeventf(ssh, "Pageant key #%d matches "
3810 "configured key file", s->keyi);
3811 s->tried_publickey = 1;
3813 /* Skip non-configured key */
3816 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3817 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3818 PKT_BIGNUM, s->key.modulus, PKT_END);
3820 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3821 logevent("Key refused");
3824 logevent("Received RSA challenge");
3825 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3826 bombout(("Server's RSA challenge was badly formatted"));
3831 char *agentreq, *q, *ret;
3834 len = 1 + 4; /* message type, bit count */
3835 len += ssh1_bignum_length(s->key.exponent);
3836 len += ssh1_bignum_length(s->key.modulus);
3837 len += ssh1_bignum_length(s->challenge);
3838 len += 16; /* session id */
3839 len += 4; /* response format */
3840 agentreq = snewn(4 + len, char);
3841 PUT_32BIT(agentreq, len);
3843 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3844 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3846 q += ssh1_write_bignum(q, s->key.exponent);
3847 q += ssh1_write_bignum(q, s->key.modulus);
3848 q += ssh1_write_bignum(q, s->challenge);
3849 memcpy(q, s->session_id, 16);
3851 PUT_32BIT(q, 1); /* response format */
3852 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3853 ssh_agent_callback, ssh)) {
3858 bombout(("Unexpected data from server"
3859 " while waiting for agent"
3863 } while (pktin || inlen > 0);
3864 vret = ssh->agent_response;
3865 retlen = ssh->agent_response_len;
3870 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3871 logevent("Sending Pageant's response");
3872 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3873 PKT_DATA, ret + 5, 16,
3877 if (pktin->type == SSH1_SMSG_SUCCESS) {
3879 ("Pageant's response accepted");
3880 if (flags & FLAG_VERBOSE) {
3881 c_write_str(ssh, "Authenticated using"
3883 c_write(ssh, s->commentp,
3885 c_write_str(ssh, "\" from agent\r\n");
3890 ("Pageant's response not accepted");
3893 ("Pageant failed to answer challenge");
3897 logevent("No reply received from Pageant");
3900 freebn(s->key.exponent);
3901 freebn(s->key.modulus);
3902 freebn(s->challenge);
3907 if (s->publickey_blob && !s->tried_publickey)
3908 logevent("Configured key file not in Pageant");
3910 logevent("Failed to get reply from Pageant");
3915 if (s->publickey_blob && !s->tried_publickey) {
3917 * Try public key authentication with the specified
3920 int got_passphrase; /* need not be kept over crReturn */
3921 if (flags & FLAG_VERBOSE)
3922 c_write_str(ssh, "Trying public key authentication.\r\n");
3923 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3924 logeventf(ssh, "Trying public key \"%s\"",
3925 filename_to_str(s->keyfile));
3926 s->tried_publickey = 1;
3927 got_passphrase = FALSE;
3928 while (!got_passphrase) {
3930 * Get a passphrase, if necessary.
3932 char *passphrase = NULL; /* only written after crReturn */
3934 if (!s->publickey_encrypted) {
3935 if (flags & FLAG_VERBOSE)
3936 c_write_str(ssh, "No passphrase required.\r\n");
3939 int ret; /* need not be kept over crReturn */
3940 s->cur_prompt = new_prompts(ssh->frontend);
3941 s->cur_prompt->to_server = FALSE;
3942 s->cur_prompt->name = dupstr("SSH key passphrase");
3943 add_prompt(s->cur_prompt,
3944 dupprintf("Passphrase for key \"%.100s\": ",
3945 s->publickey_comment), FALSE);
3946 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3949 crWaitUntil(!pktin);
3950 ret = get_userpass_input(s->cur_prompt, in, inlen);
3954 /* Failed to get a passphrase. Terminate. */
3955 free_prompts(s->cur_prompt);
3956 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3960 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3961 free_prompts(s->cur_prompt);
3964 * Try decrypting key with passphrase.
3966 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3967 ret = loadrsakey(s->keyfile, &s->key, passphrase,
3970 smemclr(passphrase, strlen(passphrase));
3974 /* Correct passphrase. */
3975 got_passphrase = TRUE;
3976 } else if (ret == 0) {
3977 c_write_str(ssh, "Couldn't load private key from ");
3978 c_write_str(ssh, filename_to_str(s->keyfile));
3979 c_write_str(ssh, " (");
3980 c_write_str(ssh, error);
3981 c_write_str(ssh, ").\r\n");
3982 got_passphrase = FALSE;
3983 break; /* go and try something else */
3984 } else if (ret == -1) {
3985 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3986 got_passphrase = FALSE;
3989 assert(0 && "unexpected return from loadrsakey()");
3990 got_passphrase = FALSE; /* placate optimisers */
3994 if (got_passphrase) {
3997 * Send a public key attempt.
3999 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4000 PKT_BIGNUM, s->key.modulus, PKT_END);
4003 if (pktin->type == SSH1_SMSG_FAILURE) {
4004 c_write_str(ssh, "Server refused our public key.\r\n");
4005 continue; /* go and try something else */
4007 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4008 bombout(("Bizarre response to offer of public key"));
4014 unsigned char buffer[32];
4015 Bignum challenge, response;
4017 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4018 bombout(("Server's RSA challenge was badly formatted"));
4021 response = rsadecrypt(challenge, &s->key);
4022 freebn(s->key.private_exponent);/* burn the evidence */
4024 for (i = 0; i < 32; i++) {
4025 buffer[i] = bignum_byte(response, 31 - i);
4029 MD5Update(&md5c, buffer, 32);
4030 MD5Update(&md5c, s->session_id, 16);
4031 MD5Final(buffer, &md5c);
4033 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4034 PKT_DATA, buffer, 16, PKT_END);
4041 if (pktin->type == SSH1_SMSG_FAILURE) {
4042 if (flags & FLAG_VERBOSE)
4043 c_write_str(ssh, "Failed to authenticate with"
4044 " our public key.\r\n");
4045 continue; /* go and try something else */
4046 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4047 bombout(("Bizarre response to RSA authentication response"));
4051 break; /* we're through! */
4057 * Otherwise, try various forms of password-like authentication.
4059 s->cur_prompt = new_prompts(ssh->frontend);
4061 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4062 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4063 !s->tis_auth_refused) {
4064 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4065 logevent("Requested TIS authentication");
4066 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4068 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4069 logevent("TIS authentication declined");
4070 if (flags & FLAG_INTERACTIVE)
4071 c_write_str(ssh, "TIS authentication refused.\r\n");
4072 s->tis_auth_refused = 1;
4077 char *instr_suf, *prompt;
4079 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4081 bombout(("TIS challenge packet was badly formed"));
4084 logevent("Received TIS challenge");
4085 s->cur_prompt->to_server = TRUE;
4086 s->cur_prompt->name = dupstr("SSH TIS authentication");
4087 /* Prompt heuristic comes from OpenSSH */
4088 if (memchr(challenge, '\n', challengelen)) {
4089 instr_suf = dupstr("");
4090 prompt = dupprintf("%.*s", challengelen, challenge);
4092 instr_suf = dupprintf("%.*s", challengelen, challenge);
4093 prompt = dupstr("Response: ");
4095 s->cur_prompt->instruction =
4096 dupprintf("Using TIS authentication.%s%s",
4097 (*instr_suf) ? "\n" : "",
4099 s->cur_prompt->instr_reqd = TRUE;
4100 add_prompt(s->cur_prompt, prompt, FALSE);
4104 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4105 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4106 !s->ccard_auth_refused) {
4107 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4108 logevent("Requested CryptoCard authentication");
4109 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4111 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4112 logevent("CryptoCard authentication declined");
4113 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4114 s->ccard_auth_refused = 1;
4119 char *instr_suf, *prompt;
4121 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4123 bombout(("CryptoCard challenge packet was badly formed"));
4126 logevent("Received CryptoCard challenge");
4127 s->cur_prompt->to_server = TRUE;
4128 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4129 s->cur_prompt->name_reqd = FALSE;
4130 /* Prompt heuristic comes from OpenSSH */
4131 if (memchr(challenge, '\n', challengelen)) {
4132 instr_suf = dupstr("");
4133 prompt = dupprintf("%.*s", challengelen, challenge);
4135 instr_suf = dupprintf("%.*s", challengelen, challenge);
4136 prompt = dupstr("Response: ");
4138 s->cur_prompt->instruction =
4139 dupprintf("Using CryptoCard authentication.%s%s",
4140 (*instr_suf) ? "\n" : "",
4142 s->cur_prompt->instr_reqd = TRUE;
4143 add_prompt(s->cur_prompt, prompt, FALSE);
4147 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4148 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4149 bombout(("No supported authentication methods available"));
4152 s->cur_prompt->to_server = TRUE;
4153 s->cur_prompt->name = dupstr("SSH password");
4154 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4155 ssh->username, ssh->savedhost),
4160 * Show password prompt, having first obtained it via a TIS
4161 * or CryptoCard exchange if we're doing TIS or CryptoCard
4165 int ret; /* need not be kept over crReturn */
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 password (for example
4176 * because one was supplied on the command line
4177 * which has already failed to work). Terminate.
4179 free_prompts(s->cur_prompt);
4180 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4185 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4187 * Defence against traffic analysis: we send a
4188 * whole bunch of packets containing strings of
4189 * different lengths. One of these strings is the
4190 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4191 * The others are all random data in
4192 * SSH1_MSG_IGNORE packets. This way a passive
4193 * listener can't tell which is the password, and
4194 * hence can't deduce the password length.
4196 * Anybody with a password length greater than 16
4197 * bytes is going to have enough entropy in their
4198 * password that a listener won't find it _that_
4199 * much help to know how long it is. So what we'll
4202 * - if password length < 16, we send 15 packets
4203 * containing string lengths 1 through 15
4205 * - otherwise, we let N be the nearest multiple
4206 * of 8 below the password length, and send 8
4207 * packets containing string lengths N through
4208 * N+7. This won't obscure the order of
4209 * magnitude of the password length, but it will
4210 * introduce a bit of extra uncertainty.
4212 * A few servers can't deal with SSH1_MSG_IGNORE, at
4213 * least in this context. For these servers, we need
4214 * an alternative defence. We make use of the fact
4215 * that the password is interpreted as a C string:
4216 * so we can append a NUL, then some random data.
4218 * A few servers can deal with neither SSH1_MSG_IGNORE
4219 * here _nor_ a padded password string.
4220 * For these servers we are left with no defences
4221 * against password length sniffing.
4223 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4224 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4226 * The server can deal with SSH1_MSG_IGNORE, so
4227 * we can use the primary defence.
4229 int bottom, top, pwlen, i;
4232 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4234 bottom = 0; /* zero length passwords are OK! :-) */
4237 bottom = pwlen & ~7;
4241 assert(pwlen >= bottom && pwlen <= top);
4243 randomstr = snewn(top + 1, char);
4245 for (i = bottom; i <= top; i++) {
4247 defer_packet(ssh, s->pwpkt_type,
4248 PKT_STR,s->cur_prompt->prompts[0]->result,
4251 for (j = 0; j < i; j++) {
4253 randomstr[j] = random_byte();
4254 } while (randomstr[j] == '\0');
4256 randomstr[i] = '\0';
4257 defer_packet(ssh, SSH1_MSG_IGNORE,
4258 PKT_STR, randomstr, PKT_END);
4261 logevent("Sending password with camouflage packets");
4262 ssh_pkt_defersend(ssh);
4265 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4267 * The server can't deal with SSH1_MSG_IGNORE
4268 * but can deal with padded passwords, so we
4269 * can use the secondary defence.
4275 len = strlen(s->cur_prompt->prompts[0]->result);
4276 if (len < sizeof(string)) {
4278 strcpy(string, s->cur_prompt->prompts[0]->result);
4279 len++; /* cover the zero byte */
4280 while (len < sizeof(string)) {
4281 string[len++] = (char) random_byte();
4284 ss = s->cur_prompt->prompts[0]->result;
4286 logevent("Sending length-padded password");
4287 send_packet(ssh, s->pwpkt_type,
4288 PKT_INT, len, PKT_DATA, ss, len,
4292 * The server is believed unable to cope with
4293 * any of our password camouflage methods.
4296 len = strlen(s->cur_prompt->prompts[0]->result);
4297 logevent("Sending unpadded password");
4298 send_packet(ssh, s->pwpkt_type,
4300 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4304 send_packet(ssh, s->pwpkt_type,
4305 PKT_STR, s->cur_prompt->prompts[0]->result,
4308 logevent("Sent password");
4309 free_prompts(s->cur_prompt);
4311 if (pktin->type == SSH1_SMSG_FAILURE) {
4312 if (flags & FLAG_VERBOSE)
4313 c_write_str(ssh, "Access denied\r\n");
4314 logevent("Authentication refused");
4315 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4316 bombout(("Strange packet received, type %d", pktin->type));
4322 if (s->publickey_blob) {
4323 sfree(s->publickey_blob);
4324 sfree(s->publickey_comment);
4327 logevent("Authentication successful");
4332 static void ssh_channel_try_eof(struct ssh_channel *c)
4335 assert(c->pending_eof); /* precondition for calling us */
4337 return; /* can't close: not even opened yet */
4338 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4339 return; /* can't send EOF: pending outgoing data */
4341 c->pending_eof = FALSE; /* we're about to send it */
4342 if (ssh->version == 1) {
4343 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4345 c->closes |= CLOSES_SENT_EOF;
4347 struct Packet *pktout;
4348 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4349 ssh2_pkt_adduint32(pktout, c->remoteid);
4350 ssh2_pkt_send(ssh, pktout);
4351 c->closes |= CLOSES_SENT_EOF;
4352 ssh2_channel_check_close(c);
4356 void sshfwd_write_eof(struct ssh_channel *c)
4360 if (ssh->state == SSH_STATE_CLOSED)
4363 if (c->closes & CLOSES_SENT_EOF)
4366 c->pending_eof = TRUE;
4367 ssh_channel_try_eof(c);
4370 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4374 if (ssh->state == SSH_STATE_CLOSED)
4379 x11_close(c->u.x11.s);
4380 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4384 case CHAN_SOCKDATA_DORMANT:
4385 pfd_close(c->u.pfd.s);
4386 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4389 c->type = CHAN_ZOMBIE;
4390 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4392 ssh2_channel_check_close(c);
4395 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4399 if (ssh->state == SSH_STATE_CLOSED)
4402 if (ssh->version == 1) {
4403 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4404 PKT_INT, c->remoteid,
4405 PKT_INT, len, PKT_DATA, buf, len,
4408 * In SSH-1 we can return 0 here - implying that forwarded
4409 * connections are never individually throttled - because
4410 * the only circumstance that can cause throttling will be
4411 * the whole SSH connection backing up, in which case
4412 * _everything_ will be throttled as a whole.
4416 ssh2_add_channel_data(c, buf, len);
4417 return ssh2_try_send(c);
4421 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4426 if (ssh->state == SSH_STATE_CLOSED)
4429 if (ssh->version == 1) {
4430 buflimit = SSH1_BUFFER_LIMIT;
4432 buflimit = c->v.v2.locmaxwin;
4433 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4435 if (c->throttling_conn && bufsize <= buflimit) {
4436 c->throttling_conn = 0;
4437 ssh_throttle_conn(ssh, -1);
4441 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4443 struct queued_handler *qh = ssh->qhead;
4447 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4450 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4451 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4454 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4455 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4459 ssh->qhead = qh->next;
4461 if (ssh->qhead->msg1 > 0) {
4462 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4463 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4465 if (ssh->qhead->msg2 > 0) {
4466 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4467 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4470 ssh->qhead = ssh->qtail = NULL;
4473 qh->handler(ssh, pktin, qh->ctx);
4478 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4479 chandler_fn_t handler, void *ctx)
4481 struct queued_handler *qh;
4483 qh = snew(struct queued_handler);
4486 qh->handler = handler;
4490 if (ssh->qtail == NULL) {
4494 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4495 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4498 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4499 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4502 ssh->qtail->next = qh;
4507 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4509 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4511 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4512 SSH2_MSG_REQUEST_SUCCESS)) {
4513 logeventf(ssh, "Remote port forwarding from %s enabled",
4516 logeventf(ssh, "Remote port forwarding from %s refused",
4519 rpf = del234(ssh->rportfwds, pf);
4521 pf->pfrec->remote = NULL;
4526 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4528 struct ssh_portfwd *epf;
4532 if (!ssh->portfwds) {
4533 ssh->portfwds = newtree234(ssh_portcmp);
4536 * Go through the existing port forwardings and tag them
4537 * with status==DESTROY. Any that we want to keep will be
4538 * re-enabled (status==KEEP) as we go through the
4539 * configuration and find out which bits are the same as
4542 struct ssh_portfwd *epf;
4544 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4545 epf->status = DESTROY;
4548 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4550 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4551 char *kp, *kp2, *vp, *vp2;
4552 char address_family, type;
4553 int sport,dport,sserv,dserv;
4554 char *sports, *dports, *saddr, *host;
4558 address_family = 'A';
4560 if (*kp == 'A' || *kp == '4' || *kp == '6')
4561 address_family = *kp++;
4562 if (*kp == 'L' || *kp == 'R')
4565 if ((kp2 = strchr(kp, ':')) != NULL) {
4567 * There's a colon in the middle of the source port
4568 * string, which means that the part before it is
4569 * actually a source address.
4571 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4577 sport = atoi(sports);
4581 sport = net_service_lookup(sports);
4583 logeventf(ssh, "Service lookup failed for source"
4584 " port \"%s\"", sports);
4588 if (type == 'L' && !strcmp(val, "D")) {
4589 /* dynamic forwarding */
4596 /* ordinary forwarding */
4598 vp2 = vp + strcspn(vp, ":");
4599 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4603 dport = atoi(dports);
4607 dport = net_service_lookup(dports);
4609 logeventf(ssh, "Service lookup failed for destination"
4610 " port \"%s\"", dports);
4615 if (sport && dport) {
4616 /* Set up a description of the source port. */
4617 struct ssh_portfwd *pfrec, *epfrec;
4619 pfrec = snew(struct ssh_portfwd);
4621 pfrec->saddr = saddr;
4622 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4623 pfrec->sport = sport;
4624 pfrec->daddr = host;
4625 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4626 pfrec->dport = dport;
4627 pfrec->local = NULL;
4628 pfrec->remote = NULL;
4629 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4630 address_family == '6' ? ADDRTYPE_IPV6 :
4633 epfrec = add234(ssh->portfwds, pfrec);
4634 if (epfrec != pfrec) {
4635 if (epfrec->status == DESTROY) {
4637 * We already have a port forwarding up and running
4638 * with precisely these parameters. Hence, no need
4639 * to do anything; simply re-tag the existing one
4642 epfrec->status = KEEP;
4645 * Anything else indicates that there was a duplicate
4646 * in our input, which we'll silently ignore.
4648 free_portfwd(pfrec);
4650 pfrec->status = CREATE;
4659 * Now go through and destroy any port forwardings which were
4662 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4663 if (epf->status == DESTROY) {
4666 message = dupprintf("%s port forwarding from %s%s%d",
4667 epf->type == 'L' ? "local" :
4668 epf->type == 'R' ? "remote" : "dynamic",
4669 epf->saddr ? epf->saddr : "",
4670 epf->saddr ? ":" : "",
4673 if (epf->type != 'D') {
4674 char *msg2 = dupprintf("%s to %s:%d", message,
4675 epf->daddr, epf->dport);
4680 logeventf(ssh, "Cancelling %s", message);
4683 /* epf->remote or epf->local may be NULL if setting up a
4684 * forwarding failed. */
4686 struct ssh_rportfwd *rpf = epf->remote;
4687 struct Packet *pktout;
4690 * Cancel the port forwarding at the server
4693 if (ssh->version == 1) {
4695 * We cannot cancel listening ports on the
4696 * server side in SSH-1! There's no message
4697 * to support it. Instead, we simply remove
4698 * the rportfwd record from the local end
4699 * so that any connections the server tries
4700 * to make on it are rejected.
4703 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4704 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4705 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4707 ssh2_pkt_addstring(pktout, epf->saddr);
4708 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4709 /* XXX: rport_acceptall may not represent
4710 * what was used to open the original connection,
4711 * since it's reconfigurable. */
4712 ssh2_pkt_addstring(pktout, "");
4714 ssh2_pkt_addstring(pktout, "localhost");
4716 ssh2_pkt_adduint32(pktout, epf->sport);
4717 ssh2_pkt_send(ssh, pktout);
4720 del234(ssh->rportfwds, rpf);
4722 } else if (epf->local) {
4723 pfd_terminate(epf->local);
4726 delpos234(ssh->portfwds, i);
4728 i--; /* so we don't skip one in the list */
4732 * And finally, set up any new port forwardings (status==CREATE).
4734 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4735 if (epf->status == CREATE) {
4736 char *sportdesc, *dportdesc;
4737 sportdesc = dupprintf("%s%s%s%s%d%s",
4738 epf->saddr ? epf->saddr : "",
4739 epf->saddr ? ":" : "",
4740 epf->sserv ? epf->sserv : "",
4741 epf->sserv ? "(" : "",
4743 epf->sserv ? ")" : "");
4744 if (epf->type == 'D') {
4747 dportdesc = dupprintf("%s:%s%s%d%s",
4749 epf->dserv ? epf->dserv : "",
4750 epf->dserv ? "(" : "",
4752 epf->dserv ? ")" : "");
4755 if (epf->type == 'L') {
4756 const char *err = pfd_addforward(epf->daddr, epf->dport,
4757 epf->saddr, epf->sport,
4760 epf->addressfamily);
4762 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4763 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4764 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4765 sportdesc, dportdesc,
4766 err ? " failed: " : "", err ? err : "");
4767 } else if (epf->type == 'D') {
4768 const char *err = pfd_addforward(NULL, -1,
4769 epf->saddr, epf->sport,
4772 epf->addressfamily);
4774 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4775 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4776 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4778 err ? " failed: " : "", err ? err : "");
4780 struct ssh_rportfwd *pf;
4783 * Ensure the remote port forwardings tree exists.
4785 if (!ssh->rportfwds) {
4786 if (ssh->version == 1)
4787 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4789 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4792 pf = snew(struct ssh_rportfwd);
4793 pf->dhost = dupstr(epf->daddr);
4794 pf->dport = epf->dport;
4796 pf->shost = dupstr(epf->saddr);
4797 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4798 pf->shost = dupstr("");
4800 pf->shost = dupstr("localhost");
4802 pf->sport = epf->sport;
4803 if (add234(ssh->rportfwds, pf) != pf) {
4804 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4805 epf->daddr, epf->dport);
4808 logeventf(ssh, "Requesting remote port %s"
4809 " forward to %s", sportdesc, dportdesc);
4811 pf->sportdesc = sportdesc;
4816 if (ssh->version == 1) {
4817 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4818 PKT_INT, epf->sport,
4819 PKT_STR, epf->daddr,
4820 PKT_INT, epf->dport,
4822 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4824 ssh_rportfwd_succfail, pf);
4826 struct Packet *pktout;
4827 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4828 ssh2_pkt_addstring(pktout, "tcpip-forward");
4829 ssh2_pkt_addbool(pktout, 1);/* want reply */
4830 ssh2_pkt_addstring(pktout, pf->shost);
4831 ssh2_pkt_adduint32(pktout, pf->sport);
4832 ssh2_pkt_send(ssh, pktout);
4834 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4835 SSH2_MSG_REQUEST_FAILURE,
4836 ssh_rportfwd_succfail, pf);
4845 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4848 int stringlen, bufsize;
4850 ssh_pkt_getstring(pktin, &string, &stringlen);
4851 if (string == NULL) {
4852 bombout(("Incoming terminal data packet was badly formed"));
4856 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4858 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4859 ssh->v1_stdout_throttling = 1;
4860 ssh_throttle_conn(ssh, +1);
4864 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4866 /* Remote side is trying to open a channel to talk to our
4867 * X-Server. Give them back a local channel number. */
4868 struct ssh_channel *c;
4869 int remoteid = ssh_pkt_getuint32(pktin);
4871 logevent("Received X11 connect request");
4872 /* Refuse if X11 forwarding is disabled. */
4873 if (!ssh->X11_fwd_enabled) {
4874 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4875 PKT_INT, remoteid, PKT_END);
4876 logevent("Rejected X11 connect request");
4878 c = snew(struct ssh_channel);
4881 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4882 NULL, -1, ssh->conf) != NULL) {
4883 logevent("Opening X11 forward connection failed");
4885 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4886 PKT_INT, remoteid, PKT_END);
4889 ("Opening X11 forward connection succeeded");
4890 c->remoteid = remoteid;
4891 c->halfopen = FALSE;
4892 c->localid = alloc_channel_id(ssh);
4894 c->pending_eof = FALSE;
4895 c->throttling_conn = 0;
4896 c->type = CHAN_X11; /* identify channel type */
4897 add234(ssh->channels, c);
4898 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4899 PKT_INT, c->remoteid, PKT_INT,
4900 c->localid, PKT_END);
4901 logevent("Opened X11 forward channel");
4906 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4908 /* Remote side is trying to open a channel to talk to our
4909 * agent. Give them back a local channel number. */
4910 struct ssh_channel *c;
4911 int remoteid = ssh_pkt_getuint32(pktin);
4913 /* Refuse if agent forwarding is disabled. */
4914 if (!ssh->agentfwd_enabled) {
4915 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4916 PKT_INT, remoteid, PKT_END);
4918 c = snew(struct ssh_channel);
4920 c->remoteid = remoteid;
4921 c->halfopen = FALSE;
4922 c->localid = alloc_channel_id(ssh);
4924 c->pending_eof = FALSE;
4925 c->throttling_conn = 0;
4926 c->type = CHAN_AGENT; /* identify channel type */
4927 c->u.a.lensofar = 0;
4928 c->u.a.message = NULL;
4929 c->u.a.outstanding_requests = 0;
4930 add234(ssh->channels, c);
4931 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4932 PKT_INT, c->remoteid, PKT_INT, c->localid,
4937 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4939 /* Remote side is trying to open a channel to talk to a
4940 * forwarded port. Give them back a local channel number. */
4941 struct ssh_rportfwd pf, *pfp;
4947 remoteid = ssh_pkt_getuint32(pktin);
4948 ssh_pkt_getstring(pktin, &host, &hostsize);
4949 port = ssh_pkt_getuint32(pktin);
4951 pf.dhost = dupprintf(".*s", hostsize, host);
4953 pfp = find234(ssh->rportfwds, &pf, NULL);
4956 logeventf(ssh, "Rejected remote port open request for %s:%d",
4958 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4959 PKT_INT, remoteid, PKT_END);
4961 struct ssh_channel *c = snew(struct ssh_channel);
4964 logeventf(ssh, "Received remote port open request for %s:%d",
4966 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4967 c, ssh->conf, pfp->pfrec->addressfamily);
4969 logeventf(ssh, "Port open failed: %s", e);
4971 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4972 PKT_INT, remoteid, PKT_END);
4974 c->remoteid = remoteid;
4975 c->halfopen = FALSE;
4976 c->localid = alloc_channel_id(ssh);
4978 c->pending_eof = FALSE;
4979 c->throttling_conn = 0;
4980 c->type = CHAN_SOCKDATA; /* identify channel type */
4981 add234(ssh->channels, c);
4982 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4983 PKT_INT, c->remoteid, PKT_INT,
4984 c->localid, PKT_END);
4985 logevent("Forwarded port opened successfully");
4992 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4994 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4995 unsigned int localid = ssh_pkt_getuint32(pktin);
4996 struct ssh_channel *c;
4998 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4999 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5000 c->remoteid = localid;
5001 c->halfopen = FALSE;
5002 c->type = CHAN_SOCKDATA;
5003 c->throttling_conn = 0;
5004 pfd_confirm(c->u.pfd.s);
5007 if (c && c->pending_eof) {
5009 * We have a pending close on this channel,
5010 * which we decided on before the server acked
5011 * the channel open. So now we know the
5012 * remoteid, we can close it again.
5014 ssh_channel_try_eof(c);
5018 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5020 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5021 struct ssh_channel *c;
5023 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5024 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5025 logevent("Forwarded connection refused by server");
5026 pfd_close(c->u.pfd.s);
5027 del234(ssh->channels, c);
5032 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5034 /* Remote side closes a channel. */
5035 unsigned i = ssh_pkt_getuint32(pktin);
5036 struct ssh_channel *c;
5037 c = find234(ssh->channels, &i, ssh_channelfind);
5038 if (c && !c->halfopen) {
5040 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5041 !(c->closes & CLOSES_RCVD_EOF)) {
5043 * Received CHANNEL_CLOSE, which we translate into
5046 int send_close = FALSE;
5048 c->closes |= CLOSES_RCVD_EOF;
5053 x11_send_eof(c->u.x11.s);
5059 pfd_send_eof(c->u.pfd.s);
5068 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5069 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5071 c->closes |= CLOSES_SENT_EOF;
5075 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5076 !(c->closes & CLOSES_RCVD_CLOSE)) {
5078 if (!(c->closes & CLOSES_SENT_EOF)) {
5079 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5080 " for which we never sent CHANNEL_CLOSE\n", i));
5083 c->closes |= CLOSES_RCVD_CLOSE;
5086 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5087 !(c->closes & CLOSES_SENT_CLOSE)) {
5088 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5089 PKT_INT, c->remoteid, PKT_END);
5090 c->closes |= CLOSES_SENT_CLOSE;
5093 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5094 ssh_channel_destroy(c);
5096 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5097 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5098 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5103 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5105 /* Data sent down one of our channels. */
5106 int i = ssh_pkt_getuint32(pktin);
5109 struct ssh_channel *c;
5111 ssh_pkt_getstring(pktin, &p, &len);
5113 c = find234(ssh->channels, &i, ssh_channelfind);
5118 bufsize = x11_send(c->u.x11.s, p, len);
5121 bufsize = pfd_send(c->u.pfd.s, p, len);
5124 /* Data for an agent message. Buffer it. */
5126 if (c->u.a.lensofar < 4) {
5127 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5128 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5132 c->u.a.lensofar += l;
5134 if (c->u.a.lensofar == 4) {
5136 4 + GET_32BIT(c->u.a.msglen);
5137 c->u.a.message = snewn(c->u.a.totallen,
5139 memcpy(c->u.a.message, c->u.a.msglen, 4);
5141 if (c->u.a.lensofar >= 4 && len > 0) {
5143 min(c->u.a.totallen - c->u.a.lensofar,
5145 memcpy(c->u.a.message + c->u.a.lensofar, p,
5149 c->u.a.lensofar += l;
5151 if (c->u.a.lensofar == c->u.a.totallen) {
5154 c->u.a.outstanding_requests++;
5155 if (agent_query(c->u.a.message,
5158 ssh_agentf_callback, c))
5159 ssh_agentf_callback(c, reply, replylen);
5160 sfree(c->u.a.message);
5161 c->u.a.lensofar = 0;
5164 bufsize = 0; /* agent channels never back up */
5167 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5168 c->throttling_conn = 1;
5169 ssh_throttle_conn(ssh, +1);
5174 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5176 ssh->exitcode = ssh_pkt_getuint32(pktin);
5177 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5178 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5180 * In case `helpful' firewalls or proxies tack
5181 * extra human-readable text on the end of the
5182 * session which we might mistake for another
5183 * encrypted packet, we close the session once
5184 * we've sent EXIT_CONFIRMATION.
5186 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5189 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5190 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5192 struct Packet *pktout = (struct Packet *)data;
5194 unsigned int arg = 0;
5195 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5196 if (i == lenof(ssh_ttymodes)) return;
5197 switch (ssh_ttymodes[i].type) {
5199 arg = ssh_tty_parse_specchar(val);
5202 arg = ssh_tty_parse_boolean(val);
5205 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5206 ssh2_pkt_addbyte(pktout, arg);
5210 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5211 struct Packet *pktin)
5213 crBegin(ssh->do_ssh1_connection_crstate);
5215 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5216 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5217 ssh1_smsg_stdout_stderr_data;
5219 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5220 ssh1_msg_channel_open_confirmation;
5221 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5222 ssh1_msg_channel_open_failure;
5223 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5224 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5225 ssh1_msg_channel_close;
5226 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5227 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5229 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5230 logevent("Requesting agent forwarding");
5231 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5235 if (pktin->type != SSH1_SMSG_SUCCESS
5236 && pktin->type != SSH1_SMSG_FAILURE) {
5237 bombout(("Protocol confusion"));
5239 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5240 logevent("Agent forwarding refused");
5242 logevent("Agent forwarding enabled");
5243 ssh->agentfwd_enabled = TRUE;
5244 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5248 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5249 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5250 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5251 logevent("Requesting X11 forwarding");
5252 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5253 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5254 PKT_STR, ssh->x11disp->remoteauthprotoname,
5255 PKT_STR, ssh->x11disp->remoteauthdatastring,
5256 PKT_INT, ssh->x11disp->screennum,
5259 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5260 PKT_STR, ssh->x11disp->remoteauthprotoname,
5261 PKT_STR, ssh->x11disp->remoteauthdatastring,
5267 if (pktin->type != SSH1_SMSG_SUCCESS
5268 && pktin->type != SSH1_SMSG_FAILURE) {
5269 bombout(("Protocol confusion"));
5271 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5272 logevent("X11 forwarding refused");
5274 logevent("X11 forwarding enabled");
5275 ssh->X11_fwd_enabled = TRUE;
5276 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5280 ssh_setup_portfwd(ssh, ssh->conf);
5281 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5283 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5285 /* Unpick the terminal-speed string. */
5286 /* XXX perhaps we should allow no speeds to be sent. */
5287 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5288 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5289 /* Send the pty request. */
5290 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5291 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5292 ssh_pkt_adduint32(pkt, ssh->term_height);
5293 ssh_pkt_adduint32(pkt, ssh->term_width);
5294 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5295 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5296 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5297 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5298 ssh_pkt_adduint32(pkt, ssh->ispeed);
5299 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5300 ssh_pkt_adduint32(pkt, ssh->ospeed);
5301 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5303 ssh->state = SSH_STATE_INTERMED;
5307 if (pktin->type != SSH1_SMSG_SUCCESS
5308 && pktin->type != SSH1_SMSG_FAILURE) {
5309 bombout(("Protocol confusion"));
5311 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5312 c_write_str(ssh, "Server refused to allocate pty\r\n");
5313 ssh->editing = ssh->echoing = 1;
5315 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5316 ssh->ospeed, ssh->ispeed);
5317 ssh->got_pty = TRUE;
5320 ssh->editing = ssh->echoing = 1;
5323 if (conf_get_int(ssh->conf, CONF_compression)) {
5324 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5328 if (pktin->type != SSH1_SMSG_SUCCESS
5329 && pktin->type != SSH1_SMSG_FAILURE) {
5330 bombout(("Protocol confusion"));
5332 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5333 c_write_str(ssh, "Server refused to compress\r\n");
5335 logevent("Started compression");
5336 ssh->v1_compressing = TRUE;
5337 ssh->cs_comp_ctx = zlib_compress_init();
5338 logevent("Initialised zlib (RFC1950) compression");
5339 ssh->sc_comp_ctx = zlib_decompress_init();
5340 logevent("Initialised zlib (RFC1950) decompression");
5344 * Start the shell or command.
5346 * Special case: if the first-choice command is an SSH-2
5347 * subsystem (hence not usable here) and the second choice
5348 * exists, we fall straight back to that.
5351 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5353 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5354 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5355 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5356 ssh->fallback_cmd = TRUE;
5359 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5361 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5362 logevent("Started session");
5365 ssh->state = SSH_STATE_SESSION;
5366 if (ssh->size_needed)
5367 ssh_size(ssh, ssh->term_width, ssh->term_height);
5368 if (ssh->eof_needed)
5369 ssh_special(ssh, TS_EOF);
5372 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5374 ssh->channels = newtree234(ssh_channelcmp);
5378 * By this point, most incoming packets are already being
5379 * handled by the dispatch table, and we need only pay
5380 * attention to the unusual ones.
5385 if (pktin->type == SSH1_SMSG_SUCCESS) {
5386 /* may be from EXEC_SHELL on some servers */
5387 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5388 /* may be from EXEC_SHELL on some servers
5389 * if no pty is available or in other odd cases. Ignore */
5391 bombout(("Strange packet received: type %d", pktin->type));
5396 int len = min(inlen, 512);
5397 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5398 PKT_INT, len, PKT_DATA, in, len,
5410 * Handle the top-level SSH-2 protocol.
5412 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5417 ssh_pkt_getstring(pktin, &msg, &msglen);
5418 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5421 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5423 /* log reason code in disconnect message */
5427 ssh_pkt_getstring(pktin, &msg, &msglen);
5428 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5431 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5433 /* Do nothing, because we're ignoring it! Duhh. */
5436 static void ssh1_protocol_setup(Ssh ssh)
5441 * Most messages are handled by the coroutines.
5443 for (i = 0; i < 256; i++)
5444 ssh->packet_dispatch[i] = NULL;
5447 * These special message types we install handlers for.
5449 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5450 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5451 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5454 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5455 struct Packet *pktin)
5457 unsigned char *in=(unsigned char*)vin;
5458 if (ssh->state == SSH_STATE_CLOSED)
5461 if (pktin && ssh->packet_dispatch[pktin->type]) {
5462 ssh->packet_dispatch[pktin->type](ssh, pktin);
5466 if (!ssh->protocol_initial_phase_done) {
5467 if (do_ssh1_login(ssh, in, inlen, pktin))
5468 ssh->protocol_initial_phase_done = TRUE;
5473 do_ssh1_connection(ssh, in, inlen, pktin);
5477 * Utility routine for decoding comma-separated strings in KEXINIT.
5479 static int in_commasep_string(char *needle, char *haystack, int haylen)
5482 if (!needle || !haystack) /* protect against null pointers */
5484 needlen = strlen(needle);
5487 * Is it at the start of the string?
5489 if (haylen >= needlen && /* haystack is long enough */
5490 !memcmp(needle, haystack, needlen) && /* initial match */
5491 (haylen == needlen || haystack[needlen] == ',')
5492 /* either , or EOS follows */
5496 * If not, search for the next comma and resume after that.
5497 * If no comma found, terminate.
5499 while (haylen > 0 && *haystack != ',')
5500 haylen--, haystack++;
5503 haylen--, haystack++; /* skip over comma itself */
5508 * Similar routine for checking whether we have the first string in a list.
5510 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5513 if (!needle || !haystack) /* protect against null pointers */
5515 needlen = strlen(needle);
5517 * Is it at the start of the string?
5519 if (haylen >= needlen && /* haystack is long enough */
5520 !memcmp(needle, haystack, needlen) && /* initial match */
5521 (haylen == needlen || haystack[needlen] == ',')
5522 /* either , or EOS follows */
5530 * SSH-2 key creation method.
5531 * (Currently assumes 2 lots of any hash are sufficient to generate
5532 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5534 #define SSH2_MKKEY_ITERS (2)
5535 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5536 unsigned char *keyspace)
5538 const struct ssh_hash *h = ssh->kex->hash;
5540 /* First hlen bytes. */
5542 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5543 hash_mpint(h, s, K);
5544 h->bytes(s, H, h->hlen);
5545 h->bytes(s, &chr, 1);
5546 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5547 h->final(s, keyspace);
5548 /* Next hlen bytes. */
5550 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5551 hash_mpint(h, s, K);
5552 h->bytes(s, H, h->hlen);
5553 h->bytes(s, keyspace, h->hlen);
5554 h->final(s, keyspace + h->hlen);
5558 * Handle the SSH-2 transport layer.
5560 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5561 struct Packet *pktin)
5563 unsigned char *in = (unsigned char *)vin;
5564 struct do_ssh2_transport_state {
5566 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5567 Bignum p, g, e, f, K;
5570 int kex_init_value, kex_reply_value;
5571 const struct ssh_mac **maclist;
5573 const struct ssh2_cipher *cscipher_tobe;
5574 const struct ssh2_cipher *sccipher_tobe;
5575 const struct ssh_mac *csmac_tobe;
5576 const struct ssh_mac *scmac_tobe;
5577 const struct ssh_compress *cscomp_tobe;
5578 const struct ssh_compress *sccomp_tobe;
5579 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5580 int hostkeylen, siglen, rsakeylen;
5581 void *hkey; /* actual host key */
5582 void *rsakey; /* for RSA kex */
5583 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5584 int n_preferred_kex;
5585 const struct ssh_kexes *preferred_kex[KEX_MAX];
5586 int n_preferred_ciphers;
5587 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5588 const struct ssh_compress *preferred_comp;
5589 int userauth_succeeded; /* for delayed compression */
5590 int pending_compression;
5591 int got_session_id, activated_authconn;
5592 struct Packet *pktout;
5597 crState(do_ssh2_transport_state);
5601 s->cscipher_tobe = s->sccipher_tobe = NULL;
5602 s->csmac_tobe = s->scmac_tobe = NULL;
5603 s->cscomp_tobe = s->sccomp_tobe = NULL;
5605 s->got_session_id = s->activated_authconn = FALSE;
5606 s->userauth_succeeded = FALSE;
5607 s->pending_compression = FALSE;
5610 * Be prepared to work around the buggy MAC problem.
5612 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5613 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5615 s->maclist = macs, s->nmacs = lenof(macs);
5618 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5620 int i, j, k, commalist_started;
5623 * Set up the preferred key exchange. (NULL => warn below here)
5625 s->n_preferred_kex = 0;
5626 for (i = 0; i < KEX_MAX; i++) {
5627 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5629 s->preferred_kex[s->n_preferred_kex++] =
5630 &ssh_diffiehellman_gex;
5633 s->preferred_kex[s->n_preferred_kex++] =
5634 &ssh_diffiehellman_group14;
5637 s->preferred_kex[s->n_preferred_kex++] =
5638 &ssh_diffiehellman_group1;
5641 s->preferred_kex[s->n_preferred_kex++] =
5645 /* Flag for later. Don't bother if it's the last in
5647 if (i < KEX_MAX - 1) {
5648 s->preferred_kex[s->n_preferred_kex++] = NULL;
5655 * Set up the preferred ciphers. (NULL => warn below here)
5657 s->n_preferred_ciphers = 0;
5658 for (i = 0; i < CIPHER_MAX; i++) {
5659 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5660 case CIPHER_BLOWFISH:
5661 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5664 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5665 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5669 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5672 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5674 case CIPHER_ARCFOUR:
5675 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5678 /* Flag for later. Don't bother if it's the last in
5680 if (i < CIPHER_MAX - 1) {
5681 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5688 * Set up preferred compression.
5690 if (conf_get_int(ssh->conf, CONF_compression))
5691 s->preferred_comp = &ssh_zlib;
5693 s->preferred_comp = &ssh_comp_none;
5696 * Enable queueing of outgoing auth- or connection-layer
5697 * packets while we are in the middle of a key exchange.
5699 ssh->queueing = TRUE;
5702 * Flag that KEX is in progress.
5704 ssh->kex_in_progress = TRUE;
5707 * Construct and send our key exchange packet.
5709 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5710 for (i = 0; i < 16; i++)
5711 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5712 /* List key exchange algorithms. */
5713 ssh2_pkt_addstring_start(s->pktout);
5714 commalist_started = 0;
5715 for (i = 0; i < s->n_preferred_kex; i++) {
5716 const struct ssh_kexes *k = s->preferred_kex[i];
5717 if (!k) continue; /* warning flag */
5718 for (j = 0; j < k->nkexes; j++) {
5719 if (commalist_started)
5720 ssh2_pkt_addstring_str(s->pktout, ",");
5721 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5722 commalist_started = 1;
5725 /* List server host key algorithms. */
5726 if (!s->got_session_id) {
5728 * In the first key exchange, we list all the algorithms
5729 * we're prepared to cope with.
5731 ssh2_pkt_addstring_start(s->pktout);
5732 for (i = 0; i < lenof(hostkey_algs); i++) {
5733 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5734 if (i < lenof(hostkey_algs) - 1)
5735 ssh2_pkt_addstring_str(s->pktout, ",");
5739 * In subsequent key exchanges, we list only the kex
5740 * algorithm that was selected in the first key exchange,
5741 * so that we keep getting the same host key and hence
5742 * don't have to interrupt the user's session to ask for
5746 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5748 /* List encryption algorithms (client->server then server->client). */
5749 for (k = 0; k < 2; k++) {
5750 ssh2_pkt_addstring_start(s->pktout);
5751 commalist_started = 0;
5752 for (i = 0; i < s->n_preferred_ciphers; i++) {
5753 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5754 if (!c) continue; /* warning flag */
5755 for (j = 0; j < c->nciphers; j++) {
5756 if (commalist_started)
5757 ssh2_pkt_addstring_str(s->pktout, ",");
5758 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5759 commalist_started = 1;
5763 /* List MAC algorithms (client->server then server->client). */
5764 for (j = 0; j < 2; j++) {
5765 ssh2_pkt_addstring_start(s->pktout);
5766 for (i = 0; i < s->nmacs; i++) {
5767 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5768 if (i < s->nmacs - 1)
5769 ssh2_pkt_addstring_str(s->pktout, ",");
5772 /* List client->server compression algorithms,
5773 * then server->client compression algorithms. (We use the
5774 * same set twice.) */
5775 for (j = 0; j < 2; j++) {
5776 ssh2_pkt_addstring_start(s->pktout);
5777 assert(lenof(compressions) > 1);
5778 /* Prefer non-delayed versions */
5779 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5780 /* We don't even list delayed versions of algorithms until
5781 * they're allowed to be used, to avoid a race. See the end of
5783 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5784 ssh2_pkt_addstring_str(s->pktout, ",");
5785 ssh2_pkt_addstring_str(s->pktout,
5786 s->preferred_comp->delayed_name);
5788 for (i = 0; i < lenof(compressions); i++) {
5789 const struct ssh_compress *c = compressions[i];
5790 if (c != s->preferred_comp) {
5791 ssh2_pkt_addstring_str(s->pktout, ",");
5792 ssh2_pkt_addstring_str(s->pktout, c->name);
5793 if (s->userauth_succeeded && c->delayed_name) {
5794 ssh2_pkt_addstring_str(s->pktout, ",");
5795 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5800 /* List client->server languages. Empty list. */
5801 ssh2_pkt_addstring_start(s->pktout);
5802 /* List server->client languages. Empty list. */
5803 ssh2_pkt_addstring_start(s->pktout);
5804 /* First KEX packet does _not_ follow, because we're not that brave. */
5805 ssh2_pkt_addbool(s->pktout, FALSE);
5807 ssh2_pkt_adduint32(s->pktout, 0);
5810 s->our_kexinitlen = s->pktout->length - 5;
5811 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5812 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5814 ssh2_pkt_send_noqueue(ssh, s->pktout);
5817 crWaitUntilV(pktin);
5820 * Now examine the other side's KEXINIT to see what we're up
5824 char *str, *preferred;
5827 if (pktin->type != SSH2_MSG_KEXINIT) {
5828 bombout(("expected key exchange packet from server"));
5832 ssh->hostkey = NULL;
5833 s->cscipher_tobe = NULL;
5834 s->sccipher_tobe = NULL;
5835 s->csmac_tobe = NULL;
5836 s->scmac_tobe = NULL;
5837 s->cscomp_tobe = NULL;
5838 s->sccomp_tobe = NULL;
5839 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5841 pktin->savedpos += 16; /* skip garbage cookie */
5842 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5845 for (i = 0; i < s->n_preferred_kex; i++) {
5846 const struct ssh_kexes *k = s->preferred_kex[i];
5850 for (j = 0; j < k->nkexes; j++) {
5851 if (!preferred) preferred = k->list[j]->name;
5852 if (in_commasep_string(k->list[j]->name, str, len)) {
5853 ssh->kex = k->list[j];
5862 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5863 str ? str : "(null)"));
5867 * Note that the server's guess is considered wrong if it doesn't match
5868 * the first algorithm in our list, even if it's still the algorithm
5871 s->guessok = first_in_commasep_string(preferred, str, len);
5872 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5873 for (i = 0; i < lenof(hostkey_algs); i++) {
5874 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5875 ssh->hostkey = hostkey_algs[i];
5879 if (!ssh->hostkey) {
5880 bombout(("Couldn't agree a host key algorithm (available: %s)",
5881 str ? str : "(null)"));
5885 s->guessok = s->guessok &&
5886 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5887 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5888 for (i = 0; i < s->n_preferred_ciphers; i++) {
5889 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5891 s->warn_cscipher = TRUE;
5893 for (j = 0; j < c->nciphers; j++) {
5894 if (in_commasep_string(c->list[j]->name, str, len)) {
5895 s->cscipher_tobe = c->list[j];
5900 if (s->cscipher_tobe)
5903 if (!s->cscipher_tobe) {
5904 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5905 str ? str : "(null)"));
5909 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5910 for (i = 0; i < s->n_preferred_ciphers; i++) {
5911 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5913 s->warn_sccipher = TRUE;
5915 for (j = 0; j < c->nciphers; j++) {
5916 if (in_commasep_string(c->list[j]->name, str, len)) {
5917 s->sccipher_tobe = c->list[j];
5922 if (s->sccipher_tobe)
5925 if (!s->sccipher_tobe) {
5926 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5927 str ? str : "(null)"));
5931 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5932 for (i = 0; i < s->nmacs; i++) {
5933 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5934 s->csmac_tobe = s->maclist[i];
5938 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5939 for (i = 0; i < s->nmacs; i++) {
5940 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5941 s->scmac_tobe = s->maclist[i];
5945 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5946 for (i = 0; i < lenof(compressions) + 1; i++) {
5947 const struct ssh_compress *c =
5948 i == 0 ? s->preferred_comp : compressions[i - 1];
5949 if (in_commasep_string(c->name, str, len)) {
5952 } else if (in_commasep_string(c->delayed_name, str, len)) {
5953 if (s->userauth_succeeded) {
5957 s->pending_compression = TRUE; /* try this later */
5961 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5962 for (i = 0; i < lenof(compressions) + 1; i++) {
5963 const struct ssh_compress *c =
5964 i == 0 ? s->preferred_comp : compressions[i - 1];
5965 if (in_commasep_string(c->name, str, len)) {
5968 } else if (in_commasep_string(c->delayed_name, str, len)) {
5969 if (s->userauth_succeeded) {
5973 s->pending_compression = TRUE; /* try this later */
5977 if (s->pending_compression) {
5978 logevent("Server supports delayed compression; "
5979 "will try this later");
5981 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5982 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5983 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5985 ssh->exhash = ssh->kex->hash->init();
5986 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5987 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5988 hash_string(ssh->kex->hash, ssh->exhash,
5989 s->our_kexinit, s->our_kexinitlen);
5990 sfree(s->our_kexinit);
5991 /* Include the type byte in the hash of server's KEXINIT */
5992 hash_string(ssh->kex->hash, ssh->exhash,
5993 pktin->body - 1, pktin->length + 1);
5996 ssh_set_frozen(ssh, 1);
5997 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5999 ssh_dialog_callback, ssh);
6000 if (s->dlgret < 0) {
6004 bombout(("Unexpected data from server while"
6005 " waiting for user response"));
6008 } while (pktin || inlen > 0);
6009 s->dlgret = ssh->user_response;
6011 ssh_set_frozen(ssh, 0);
6012 if (s->dlgret == 0) {
6013 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6019 if (s->warn_cscipher) {
6020 ssh_set_frozen(ssh, 1);
6021 s->dlgret = askalg(ssh->frontend,
6022 "client-to-server cipher",
6023 s->cscipher_tobe->name,
6024 ssh_dialog_callback, ssh);
6025 if (s->dlgret < 0) {
6029 bombout(("Unexpected data from server while"
6030 " waiting for user response"));
6033 } while (pktin || inlen > 0);
6034 s->dlgret = ssh->user_response;
6036 ssh_set_frozen(ssh, 0);
6037 if (s->dlgret == 0) {
6038 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6044 if (s->warn_sccipher) {
6045 ssh_set_frozen(ssh, 1);
6046 s->dlgret = askalg(ssh->frontend,
6047 "server-to-client cipher",
6048 s->sccipher_tobe->name,
6049 ssh_dialog_callback, ssh);
6050 if (s->dlgret < 0) {
6054 bombout(("Unexpected data from server while"
6055 " waiting for user response"));
6058 } while (pktin || inlen > 0);
6059 s->dlgret = ssh->user_response;
6061 ssh_set_frozen(ssh, 0);
6062 if (s->dlgret == 0) {
6063 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6069 if (s->ignorepkt) /* first_kex_packet_follows */
6070 crWaitUntilV(pktin); /* Ignore packet */
6073 if (ssh->kex->main_type == KEXTYPE_DH) {
6075 * Work out the number of bits of key we will need from the
6076 * key exchange. We start with the maximum key length of
6082 csbits = s->cscipher_tobe->keylen;
6083 scbits = s->sccipher_tobe->keylen;
6084 s->nbits = (csbits > scbits ? csbits : scbits);
6086 /* The keys only have hlen-bit entropy, since they're based on
6087 * a hash. So cap the key size at hlen bits. */
6088 if (s->nbits > ssh->kex->hash->hlen * 8)
6089 s->nbits = ssh->kex->hash->hlen * 8;
6092 * If we're doing Diffie-Hellman group exchange, start by
6093 * requesting a group.
6095 if (!ssh->kex->pdata) {
6096 logevent("Doing Diffie-Hellman group exchange");
6097 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6099 * Work out how big a DH group we will need to allow that
6102 s->pbits = 512 << ((s->nbits - 1) / 64);
6103 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6104 ssh2_pkt_adduint32(s->pktout, s->pbits);
6105 ssh2_pkt_send_noqueue(ssh, s->pktout);
6107 crWaitUntilV(pktin);
6108 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6109 bombout(("expected key exchange group packet from server"));
6112 s->p = ssh2_pkt_getmp(pktin);
6113 s->g = ssh2_pkt_getmp(pktin);
6114 if (!s->p || !s->g) {
6115 bombout(("unable to read mp-ints from incoming group packet"));
6118 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6119 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6120 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6122 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6123 ssh->kex_ctx = dh_setup_group(ssh->kex);
6124 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6125 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6126 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6127 ssh->kex->groupname);
6130 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6131 ssh->kex->hash->text_name);
6133 * Now generate and send e for Diffie-Hellman.
6135 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6136 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6137 s->pktout = ssh2_pkt_init(s->kex_init_value);
6138 ssh2_pkt_addmp(s->pktout, s->e);
6139 ssh2_pkt_send_noqueue(ssh, s->pktout);
6141 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6142 crWaitUntilV(pktin);
6143 if (pktin->type != s->kex_reply_value) {
6144 bombout(("expected key exchange reply packet from server"));
6147 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6148 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6149 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6150 s->f = ssh2_pkt_getmp(pktin);
6152 bombout(("unable to parse key exchange reply packet"));
6155 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6157 s->K = dh_find_K(ssh->kex_ctx, s->f);
6159 /* We assume everything from now on will be quick, and it might
6160 * involve user interaction. */
6161 set_busy_status(ssh->frontend, BUSY_NOT);
6163 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6164 if (!ssh->kex->pdata) {
6165 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6166 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6167 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6169 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6170 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6172 dh_cleanup(ssh->kex_ctx);
6174 if (!ssh->kex->pdata) {
6179 logeventf(ssh, "Doing RSA key exchange with hash %s",
6180 ssh->kex->hash->text_name);
6181 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6183 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6186 crWaitUntilV(pktin);
6187 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6188 bombout(("expected RSA public key packet from server"));
6192 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6193 hash_string(ssh->kex->hash, ssh->exhash,
6194 s->hostkeydata, s->hostkeylen);
6195 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6199 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6200 s->rsakeydata = snewn(s->rsakeylen, char);
6201 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6204 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6206 sfree(s->rsakeydata);
6207 bombout(("unable to parse RSA public key from server"));
6211 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6214 * Next, set up a shared secret K, of precisely KLEN -
6215 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6216 * RSA key modulus and HLEN is the bit length of the hash
6220 int klen = ssh_rsakex_klen(s->rsakey);
6221 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6223 unsigned char *kstr1, *kstr2, *outstr;
6224 int kstr1len, kstr2len, outstrlen;
6226 s->K = bn_power_2(nbits - 1);
6228 for (i = 0; i < nbits; i++) {
6230 byte = random_byte();
6232 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6236 * Encode this as an mpint.
6238 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6239 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6240 PUT_32BIT(kstr2, kstr1len);
6241 memcpy(kstr2 + 4, kstr1, kstr1len);
6244 * Encrypt it with the given RSA key.
6246 outstrlen = (klen + 7) / 8;
6247 outstr = snewn(outstrlen, unsigned char);
6248 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6249 outstr, outstrlen, s->rsakey);
6252 * And send it off in a return packet.
6254 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6255 ssh2_pkt_addstring_start(s->pktout);
6256 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6257 ssh2_pkt_send_noqueue(ssh, s->pktout);
6259 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6266 ssh_rsakex_freekey(s->rsakey);
6268 crWaitUntilV(pktin);
6269 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6270 sfree(s->rsakeydata);
6271 bombout(("expected signature packet from server"));
6275 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6277 sfree(s->rsakeydata);
6280 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6281 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6282 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6284 ssh->kex_ctx = NULL;
6287 debug(("Exchange hash is:\n"));
6288 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6292 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6293 (char *)s->exchange_hash,
6294 ssh->kex->hash->hlen)) {
6295 bombout(("Server's host key did not match the signature supplied"));
6299 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6300 if (!s->got_session_id) {
6302 * Authenticate remote host: verify host key. (We've already
6303 * checked the signature of the exchange hash.)
6305 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6306 ssh_set_frozen(ssh, 1);
6307 s->dlgret = verify_ssh_host_key(ssh->frontend,
6308 ssh->savedhost, ssh->savedport,
6309 ssh->hostkey->keytype, s->keystr,
6311 ssh_dialog_callback, ssh);
6312 if (s->dlgret < 0) {
6316 bombout(("Unexpected data from server while waiting"
6317 " for user host key response"));
6320 } while (pktin || inlen > 0);
6321 s->dlgret = ssh->user_response;
6323 ssh_set_frozen(ssh, 0);
6324 if (s->dlgret == 0) {
6325 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6329 logevent("Host key fingerprint is:");
6330 logevent(s->fingerprint);
6331 sfree(s->fingerprint);
6333 * Save this host key, to check against the one presented in
6334 * subsequent rekeys.
6336 ssh->hostkey_str = s->keystr;
6339 * In a rekey, we never present an interactive host key
6340 * verification request to the user. Instead, we simply
6341 * enforce that the key we're seeing this time is identical to
6342 * the one we saw before.
6344 if (strcmp(ssh->hostkey_str, s->keystr)) {
6345 bombout(("Host key was different in repeat key exchange"));
6350 ssh->hostkey->freekey(s->hkey);
6353 * The exchange hash from the very first key exchange is also
6354 * the session id, used in session key construction and
6357 if (!s->got_session_id) {
6358 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6359 memcpy(ssh->v2_session_id, s->exchange_hash,
6360 sizeof(s->exchange_hash));
6361 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6362 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6363 s->got_session_id = TRUE;
6367 * Send SSH2_MSG_NEWKEYS.
6369 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6370 ssh2_pkt_send_noqueue(ssh, s->pktout);
6371 ssh->outgoing_data_size = 0; /* start counting from here */
6374 * We've sent client NEWKEYS, so create and initialise
6375 * client-to-server session keys.
6377 if (ssh->cs_cipher_ctx)
6378 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6379 ssh->cscipher = s->cscipher_tobe;
6380 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6382 if (ssh->cs_mac_ctx)
6383 ssh->csmac->free_context(ssh->cs_mac_ctx);
6384 ssh->csmac = s->csmac_tobe;
6385 ssh->cs_mac_ctx = ssh->csmac->make_context();
6387 if (ssh->cs_comp_ctx)
6388 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6389 ssh->cscomp = s->cscomp_tobe;
6390 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6393 * Set IVs on client-to-server keys. Here we use the exchange
6394 * hash from the _first_ key exchange.
6397 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6398 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6399 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6400 assert((ssh->cscipher->keylen+7) / 8 <=
6401 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6402 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6403 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6404 assert(ssh->cscipher->blksize <=
6405 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6406 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6407 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6408 assert(ssh->csmac->len <=
6409 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6410 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6411 smemclr(keyspace, sizeof(keyspace));
6414 logeventf(ssh, "Initialised %.200s client->server encryption",
6415 ssh->cscipher->text_name);
6416 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6417 ssh->csmac->text_name);
6418 if (ssh->cscomp->text_name)
6419 logeventf(ssh, "Initialised %s compression",
6420 ssh->cscomp->text_name);
6423 * Now our end of the key exchange is complete, we can send all
6424 * our queued higher-layer packets.
6426 ssh->queueing = FALSE;
6427 ssh2_pkt_queuesend(ssh);
6430 * Expect SSH2_MSG_NEWKEYS from server.
6432 crWaitUntilV(pktin);
6433 if (pktin->type != SSH2_MSG_NEWKEYS) {
6434 bombout(("expected new-keys packet from server"));
6437 ssh->incoming_data_size = 0; /* start counting from here */
6440 * We've seen server NEWKEYS, so create and initialise
6441 * server-to-client session keys.
6443 if (ssh->sc_cipher_ctx)
6444 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6445 ssh->sccipher = s->sccipher_tobe;
6446 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6448 if (ssh->sc_mac_ctx)
6449 ssh->scmac->free_context(ssh->sc_mac_ctx);
6450 ssh->scmac = s->scmac_tobe;
6451 ssh->sc_mac_ctx = ssh->scmac->make_context();
6453 if (ssh->sc_comp_ctx)
6454 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6455 ssh->sccomp = s->sccomp_tobe;
6456 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6459 * Set IVs on server-to-client keys. Here we use the exchange
6460 * hash from the _first_ key exchange.
6463 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6464 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6465 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6466 assert((ssh->sccipher->keylen+7) / 8 <=
6467 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6468 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6469 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6470 assert(ssh->sccipher->blksize <=
6471 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6472 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6473 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6474 assert(ssh->scmac->len <=
6475 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6476 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6477 smemclr(keyspace, sizeof(keyspace));
6479 logeventf(ssh, "Initialised %.200s server->client encryption",
6480 ssh->sccipher->text_name);
6481 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6482 ssh->scmac->text_name);
6483 if (ssh->sccomp->text_name)
6484 logeventf(ssh, "Initialised %s decompression",
6485 ssh->sccomp->text_name);
6488 * Free shared secret.
6493 * Key exchange is over. Loop straight back round if we have a
6494 * deferred rekey reason.
6496 if (ssh->deferred_rekey_reason) {
6497 logevent(ssh->deferred_rekey_reason);
6499 ssh->deferred_rekey_reason = NULL;
6500 goto begin_key_exchange;
6504 * Otherwise, schedule a timer for our next rekey.
6506 ssh->kex_in_progress = FALSE;
6507 ssh->last_rekey = GETTICKCOUNT();
6508 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6509 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6513 * Now we're encrypting. Begin returning 1 to the protocol main
6514 * function so that other things can run on top of the
6515 * transport. If we ever see a KEXINIT, we must go back to the
6518 * We _also_ go back to the start if we see pktin==NULL and
6519 * inlen negative, because this is a special signal meaning
6520 * `initiate client-driven rekey', and `in' contains a message
6521 * giving the reason for the rekey.
6523 * inlen==-1 means always initiate a rekey;
6524 * inlen==-2 means that userauth has completed successfully and
6525 * we should consider rekeying (for delayed compression).
6527 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6528 (!pktin && inlen < 0))) {
6530 if (!ssh->protocol_initial_phase_done) {
6531 ssh->protocol_initial_phase_done = TRUE;
6533 * Allow authconn to initialise itself.
6535 do_ssh2_authconn(ssh, NULL, 0, NULL);
6540 logevent("Server initiated key re-exchange");
6544 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6545 * delayed compression, if it's available.
6547 * draft-miller-secsh-compression-delayed-00 says that you
6548 * negotiate delayed compression in the first key exchange, and
6549 * both sides start compressing when the server has sent
6550 * USERAUTH_SUCCESS. This has a race condition -- the server
6551 * can't know when the client has seen it, and thus which incoming
6552 * packets it should treat as compressed.
6554 * Instead, we do the initial key exchange without offering the
6555 * delayed methods, but note if the server offers them; when we
6556 * get here, if a delayed method was available that was higher
6557 * on our list than what we got, we initiate a rekey in which we
6558 * _do_ list the delayed methods (and hopefully get it as a
6559 * result). Subsequent rekeys will do the same.
6561 assert(!s->userauth_succeeded); /* should only happen once */
6562 s->userauth_succeeded = TRUE;
6563 if (!s->pending_compression)
6564 /* Can't see any point rekeying. */
6565 goto wait_for_rekey; /* this is utterly horrid */
6566 /* else fall through to rekey... */
6567 s->pending_compression = FALSE;
6570 * Now we've decided to rekey.
6572 * Special case: if the server bug is set that doesn't
6573 * allow rekeying, we give a different log message and
6574 * continue waiting. (If such a server _initiates_ a rekey,
6575 * we process it anyway!)
6577 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6578 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6580 /* Reset the counters, so that at least this message doesn't
6581 * hit the event log _too_ often. */
6582 ssh->outgoing_data_size = 0;
6583 ssh->incoming_data_size = 0;
6584 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6586 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6589 goto wait_for_rekey; /* this is still utterly horrid */
6591 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6594 goto begin_key_exchange;
6600 * Add data to an SSH-2 channel output buffer.
6602 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6605 bufchain_add(&c->v.v2.outbuffer, buf, len);
6609 * Attempt to send data on an SSH-2 channel.
6611 static int ssh2_try_send(struct ssh_channel *c)
6614 struct Packet *pktout;
6617 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6620 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6621 if ((unsigned)len > c->v.v2.remwindow)
6622 len = c->v.v2.remwindow;
6623 if ((unsigned)len > c->v.v2.remmaxpkt)
6624 len = c->v.v2.remmaxpkt;
6625 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6626 ssh2_pkt_adduint32(pktout, c->remoteid);
6627 ssh2_pkt_addstring_start(pktout);
6628 ssh2_pkt_addstring_data(pktout, data, len);
6629 ssh2_pkt_send(ssh, pktout);
6630 bufchain_consume(&c->v.v2.outbuffer, len);
6631 c->v.v2.remwindow -= len;
6635 * After having sent as much data as we can, return the amount
6638 ret = bufchain_size(&c->v.v2.outbuffer);
6641 * And if there's no data pending but we need to send an EOF, send
6644 if (!ret && c->pending_eof)
6645 ssh_channel_try_eof(c);
6650 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6653 if (c->closes & CLOSES_SENT_EOF)
6654 return; /* don't send on channels we've EOFed */
6655 bufsize = ssh2_try_send(c);
6658 case CHAN_MAINSESSION:
6659 /* stdin need not receive an unthrottle
6660 * notification since it will be polled */
6663 x11_unthrottle(c->u.x11.s);
6666 /* agent sockets are request/response and need no
6667 * buffer management */
6670 pfd_unthrottle(c->u.pfd.s);
6677 * Set up most of a new ssh_channel for SSH-2.
6679 static void ssh2_channel_init(struct ssh_channel *c)
6682 c->localid = alloc_channel_id(ssh);
6684 c->pending_eof = FALSE;
6685 c->throttling_conn = FALSE;
6686 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6687 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6688 c->v.v2.chanreq_head = NULL;
6689 c->v.v2.throttle_state = UNTHROTTLED;
6690 bufchain_init(&c->v.v2.outbuffer);
6694 * Construct the common parts of a CHANNEL_OPEN.
6696 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6698 struct Packet *pktout;
6700 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6701 ssh2_pkt_addstring(pktout, type);
6702 ssh2_pkt_adduint32(pktout, c->localid);
6703 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6704 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6709 * CHANNEL_FAILURE doesn't come with any indication of what message
6710 * caused it, so we have to keep track of the outstanding
6711 * CHANNEL_REQUESTs ourselves.
6713 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6714 cchandler_fn_t handler, void *ctx)
6716 struct outstanding_channel_request *ocr =
6717 snew(struct outstanding_channel_request);
6719 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6720 ocr->handler = handler;
6723 if (!c->v.v2.chanreq_head)
6724 c->v.v2.chanreq_head = ocr;
6726 c->v.v2.chanreq_tail->next = ocr;
6727 c->v.v2.chanreq_tail = ocr;
6731 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6732 * NULL then a reply will be requested and the handler will be called
6733 * when it arrives. The returned packet is ready to have any
6734 * request-specific data added and be sent. Note that if a handler is
6735 * provided, it's essential that the request actually be sent.
6737 * The handler will usually be passed the response packet in pktin.
6738 * If pktin is NULL, this means that no reply will ever be forthcoming
6739 * (e.g. because the entire connection is being destroyed) and the
6740 * handler should free any storage it's holding.
6742 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6743 cchandler_fn_t handler, void *ctx)
6745 struct Packet *pktout;
6747 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6748 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6749 ssh2_pkt_adduint32(pktout, c->remoteid);
6750 ssh2_pkt_addstring(pktout, type);
6751 ssh2_pkt_addbool(pktout, handler != NULL);
6752 if (handler != NULL)
6753 ssh2_queue_chanreq_handler(c, handler, ctx);
6758 * Potentially enlarge the window on an SSH-2 channel.
6760 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6762 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6767 * Never send WINDOW_ADJUST for a channel that the remote side has
6768 * already sent EOF on; there's no point, since it won't be
6769 * sending any more data anyway. Ditto if _we've_ already sent
6772 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6776 * If the remote end has a habit of ignoring maxpkt, limit the
6777 * window so that it has no choice (assuming it doesn't ignore the
6780 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6781 newwin = OUR_V2_MAXPKT;
6784 * Only send a WINDOW_ADJUST if there's significantly more window
6785 * available than the other end thinks there is. This saves us
6786 * sending a WINDOW_ADJUST for every character in a shell session.
6788 * "Significant" is arbitrarily defined as half the window size.
6790 if (newwin / 2 >= c->v.v2.locwindow) {
6791 struct Packet *pktout;
6795 * In order to keep track of how much window the client
6796 * actually has available, we'd like it to acknowledge each
6797 * WINDOW_ADJUST. We can't do that directly, so we accompany
6798 * it with a CHANNEL_REQUEST that has to be acknowledged.
6800 * This is only necessary if we're opening the window wide.
6801 * If we're not, then throughput is being constrained by
6802 * something other than the maximum window size anyway.
6804 if (newwin == c->v.v2.locmaxwin &&
6805 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6806 up = snew(unsigned);
6807 *up = newwin - c->v.v2.locwindow;
6808 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6809 ssh2_handle_winadj_response, up);
6810 ssh2_pkt_send(ssh, pktout);
6812 if (c->v.v2.throttle_state != UNTHROTTLED)
6813 c->v.v2.throttle_state = UNTHROTTLING;
6815 /* Pretend the WINDOW_ADJUST was acked immediately. */
6816 c->v.v2.remlocwin = newwin;
6817 c->v.v2.throttle_state = THROTTLED;
6819 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6820 ssh2_pkt_adduint32(pktout, c->remoteid);
6821 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6822 ssh2_pkt_send(ssh, pktout);
6823 c->v.v2.locwindow = newwin;
6828 * Find the channel associated with a message. If there's no channel,
6829 * or it's not properly open, make a noise about it and return NULL.
6831 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6833 unsigned localid = ssh_pkt_getuint32(pktin);
6834 struct ssh_channel *c;
6836 c = find234(ssh->channels, &localid, ssh_channelfind);
6838 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6839 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6840 char *buf = dupprintf("Received %s for %s channel %u",
6841 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6843 c ? "half-open" : "nonexistent", localid);
6844 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6851 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6852 struct Packet *pktin, void *ctx)
6854 unsigned *sizep = ctx;
6857 * Winadj responses should always be failures. However, at least
6858 * one server ("boks_sshd") is known to return SUCCESS for channel
6859 * requests it's never heard of, such as "winadj@putty". Raised
6860 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6861 * life, we don't worry about what kind of response we got.
6864 c->v.v2.remlocwin += *sizep;
6867 * winadj messages are only sent when the window is fully open, so
6868 * if we get an ack of one, we know any pending unthrottle is
6871 if (c->v.v2.throttle_state == UNTHROTTLING)
6872 c->v.v2.throttle_state = UNTHROTTLED;
6875 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6877 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6878 struct outstanding_channel_request *ocr;
6881 ocr = c->v.v2.chanreq_head;
6883 ssh2_msg_unexpected(ssh, pktin);
6886 ocr->handler(c, pktin, ocr->ctx);
6887 c->v.v2.chanreq_head = ocr->next;
6890 * We may now initiate channel-closing procedures, if that
6891 * CHANNEL_REQUEST was the last thing outstanding before we send
6894 ssh2_channel_check_close(c);
6897 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6899 struct ssh_channel *c;
6900 c = ssh2_channel_msg(ssh, pktin);
6903 if (!(c->closes & CLOSES_SENT_EOF)) {
6904 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6905 ssh2_try_send_and_unthrottle(ssh, c);
6909 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6913 struct ssh_channel *c;
6914 c = ssh2_channel_msg(ssh, pktin);
6917 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6918 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6919 return; /* extended but not stderr */
6920 ssh_pkt_getstring(pktin, &data, &length);
6923 c->v.v2.locwindow -= length;
6924 c->v.v2.remlocwin -= length;
6926 case CHAN_MAINSESSION:
6928 from_backend(ssh->frontend, pktin->type ==
6929 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6933 bufsize = x11_send(c->u.x11.s, data, length);
6936 bufsize = pfd_send(c->u.pfd.s, data, length);
6939 while (length > 0) {
6940 if (c->u.a.lensofar < 4) {
6941 unsigned int l = min(4 - c->u.a.lensofar,
6943 memcpy(c->u.a.msglen + c->u.a.lensofar,
6947 c->u.a.lensofar += l;
6949 if (c->u.a.lensofar == 4) {
6951 4 + GET_32BIT(c->u.a.msglen);
6952 c->u.a.message = snewn(c->u.a.totallen,
6954 memcpy(c->u.a.message, c->u.a.msglen, 4);
6956 if (c->u.a.lensofar >= 4 && length > 0) {
6958 min(c->u.a.totallen - c->u.a.lensofar,
6960 memcpy(c->u.a.message + c->u.a.lensofar,
6964 c->u.a.lensofar += l;
6966 if (c->u.a.lensofar == c->u.a.totallen) {
6969 c->u.a.outstanding_requests++;
6970 if (agent_query(c->u.a.message,
6973 ssh_agentf_callback, c))
6974 ssh_agentf_callback(c, reply, replylen);
6975 sfree(c->u.a.message);
6976 c->u.a.message = NULL;
6977 c->u.a.lensofar = 0;
6984 * If it looks like the remote end hit the end of its window,
6985 * and we didn't want it to do that, think about using a
6988 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6989 c->v.v2.locmaxwin < 0x40000000)
6990 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6992 * If we are not buffering too much data,
6993 * enlarge the window again at the remote side.
6994 * If we are buffering too much, we may still
6995 * need to adjust the window if the server's
6998 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6999 c->v.v2.locmaxwin - bufsize : 0);
7001 * If we're either buffering way too much data, or if we're
7002 * buffering anything at all and we're in "simple" mode,
7003 * throttle the whole channel.
7005 if ((bufsize > c->v.v2.locmaxwin ||
7006 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
7007 !c->throttling_conn) {
7008 c->throttling_conn = 1;
7009 ssh_throttle_conn(ssh, +1);
7014 static void ssh_channel_destroy(struct ssh_channel *c)
7019 case CHAN_MAINSESSION:
7020 ssh->mainchan = NULL;
7021 update_specials_menu(ssh->frontend);
7024 if (c->u.x11.s != NULL)
7025 x11_close(c->u.x11.s);
7026 logevent("Forwarded X11 connection terminated");
7029 sfree(c->u.a.message);
7032 if (c->u.pfd.s != NULL)
7033 pfd_close(c->u.pfd.s);
7034 logevent("Forwarded port closed");
7038 del234(ssh->channels, c);
7039 if (ssh->version == 2) {
7040 bufchain_clear(&c->v.v2.outbuffer);
7041 assert(c->v.v2.chanreq_head == NULL);
7046 * See if that was the last channel left open.
7047 * (This is only our termination condition if we're
7048 * not running in -N mode.)
7050 if (ssh->version == 2 &&
7051 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7052 count234(ssh->channels) == 0) {
7054 * We used to send SSH_MSG_DISCONNECT here,
7055 * because I'd believed that _every_ conforming
7056 * SSH-2 connection had to end with a disconnect
7057 * being sent by at least one side; apparently
7058 * I was wrong and it's perfectly OK to
7059 * unceremoniously slam the connection shut
7060 * when you're done, and indeed OpenSSH feels
7061 * this is more polite than sending a
7062 * DISCONNECT. So now we don't.
7064 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7068 static void ssh2_channel_check_close(struct ssh_channel *c)
7071 struct Packet *pktout;
7075 * If we've sent out our own CHANNEL_OPEN but not yet seen
7076 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7077 * it's too early to be sending close messages of any kind.
7082 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7083 c->type == CHAN_ZOMBIE) &&
7084 !c->v.v2.chanreq_head &&
7085 !(c->closes & CLOSES_SENT_CLOSE)) {
7087 * We have both sent and received EOF (or the channel is a
7088 * zombie), and we have no outstanding channel requests, which
7089 * means the channel is in final wind-up. But we haven't sent
7090 * CLOSE, so let's do so now.
7092 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7093 ssh2_pkt_adduint32(pktout, c->remoteid);
7094 ssh2_pkt_send(ssh, pktout);
7095 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7098 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7099 assert(c->v.v2.chanreq_head == NULL);
7101 * We have both sent and received CLOSE, which means we're
7102 * completely done with the channel.
7104 ssh_channel_destroy(c);
7108 static void ssh2_channel_got_eof(struct ssh_channel *c)
7110 if (c->closes & CLOSES_RCVD_EOF)
7111 return; /* already seen EOF */
7112 c->closes |= CLOSES_RCVD_EOF;
7114 if (c->type == CHAN_X11) {
7115 x11_send_eof(c->u.x11.s);
7116 } else if (c->type == CHAN_AGENT) {
7117 if (c->u.a.outstanding_requests == 0) {
7118 /* Manufacture an outgoing EOF in response to the incoming one. */
7119 sshfwd_write_eof(c);
7121 } else if (c->type == CHAN_SOCKDATA) {
7122 pfd_send_eof(c->u.pfd.s);
7123 } else if (c->type == CHAN_MAINSESSION) {
7126 if (!ssh->sent_console_eof &&
7127 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7129 * Either from_backend_eof told us that the front end
7130 * wants us to close the outgoing side of the connection
7131 * as soon as we see EOF from the far end, or else we've
7132 * unilaterally decided to do that because we've allocated
7133 * a remote pty and hence EOF isn't a particularly
7134 * meaningful concept.
7136 sshfwd_write_eof(c);
7138 ssh->sent_console_eof = TRUE;
7141 ssh2_channel_check_close(c);
7144 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7146 struct ssh_channel *c;
7148 c = ssh2_channel_msg(ssh, pktin);
7151 ssh2_channel_got_eof(c);
7154 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7156 struct ssh_channel *c;
7158 c = ssh2_channel_msg(ssh, pktin);
7163 * When we receive CLOSE on a channel, we assume it comes with an
7164 * implied EOF if we haven't seen EOF yet.
7166 ssh2_channel_got_eof(c);
7169 * And we also send an outgoing EOF, if we haven't already, on the
7170 * assumption that CLOSE is a pretty forceful announcement that
7171 * the remote side is doing away with the entire channel. (If it
7172 * had wanted to send us EOF and continue receiving data from us,
7173 * it would have just sent CHANNEL_EOF.)
7175 if (!(c->closes & CLOSES_SENT_EOF)) {
7177 * Make sure we don't read any more from whatever our local
7178 * data source is for this channel.
7181 case CHAN_MAINSESSION:
7182 ssh->send_ok = 0; /* stop trying to read from stdin */
7185 x11_override_throttle(c->u.x11.s, 1);
7188 pfd_override_throttle(c->u.pfd.s, 1);
7193 * Abandon any buffered data we still wanted to send to this
7194 * channel. Receiving a CHANNEL_CLOSE is an indication that
7195 * the server really wants to get on and _destroy_ this
7196 * channel, and it isn't going to send us any further
7197 * WINDOW_ADJUSTs to permit us to send pending stuff.
7199 bufchain_clear(&c->v.v2.outbuffer);
7202 * Send outgoing EOF.
7204 sshfwd_write_eof(c);
7208 * Now process the actual close.
7210 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7211 c->closes |= CLOSES_RCVD_CLOSE;
7212 ssh2_channel_check_close(c);
7216 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7218 struct ssh_channel *c;
7220 c = ssh2_channel_msg(ssh, pktin);
7223 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7224 c->remoteid = ssh_pkt_getuint32(pktin);
7225 c->halfopen = FALSE;
7226 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7227 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7229 if (c->type == CHAN_SOCKDATA_DORMANT) {
7230 c->type = CHAN_SOCKDATA;
7232 pfd_confirm(c->u.pfd.s);
7233 } else if (c->type == CHAN_ZOMBIE) {
7235 * This case can occur if a local socket error occurred
7236 * between us sending out CHANNEL_OPEN and receiving
7237 * OPEN_CONFIRMATION. In this case, all we can do is
7238 * immediately initiate close proceedings now that we know the
7239 * server's id to put in the close message.
7241 ssh2_channel_check_close(c);
7244 * We never expect to receive OPEN_CONFIRMATION for any
7245 * *other* channel type (since only local-to-remote port
7246 * forwardings cause us to send CHANNEL_OPEN after the main
7247 * channel is live - all other auxiliary channel types are
7248 * initiated from the server end). It's safe to enforce this
7249 * by assertion rather than by ssh_disconnect, because the
7250 * real point is that we never constructed a half-open channel
7251 * structure in the first place with any type other than the
7254 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7258 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7261 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7263 static const char *const reasons[] = {
7264 "<unknown reason code>",
7265 "Administratively prohibited",
7267 "Unknown channel type",
7268 "Resource shortage",
7270 unsigned reason_code;
7271 char *reason_string;
7273 struct ssh_channel *c;
7275 c = ssh2_channel_msg(ssh, pktin);
7278 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7280 if (c->type == CHAN_SOCKDATA_DORMANT) {
7281 reason_code = ssh_pkt_getuint32(pktin);
7282 if (reason_code >= lenof(reasons))
7283 reason_code = 0; /* ensure reasons[reason_code] in range */
7284 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7285 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7286 reasons[reason_code], reason_length, reason_string);
7288 pfd_close(c->u.pfd.s);
7289 } else if (c->type == CHAN_ZOMBIE) {
7291 * This case can occur if a local socket error occurred
7292 * between us sending out CHANNEL_OPEN and receiving
7293 * OPEN_FAILURE. In this case, we need do nothing except allow
7294 * the code below to throw the half-open channel away.
7298 * We never expect to receive OPEN_FAILURE for any *other*
7299 * channel type (since only local-to-remote port forwardings
7300 * cause us to send CHANNEL_OPEN after the main channel is
7301 * live - all other auxiliary channel types are initiated from
7302 * the server end). It's safe to enforce this by assertion
7303 * rather than by ssh_disconnect, because the real point is
7304 * that we never constructed a half-open channel structure in
7305 * the first place with any type other than the above.
7307 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7310 del234(ssh->channels, c);
7314 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7317 int typelen, want_reply;
7318 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7319 struct ssh_channel *c;
7320 struct Packet *pktout;
7322 c = ssh2_channel_msg(ssh, pktin);
7325 ssh_pkt_getstring(pktin, &type, &typelen);
7326 want_reply = ssh2_pkt_getbool(pktin);
7329 * Having got the channel number, we now look at
7330 * the request type string to see if it's something
7333 if (c == ssh->mainchan) {
7335 * We recognise "exit-status" and "exit-signal" on
7336 * the primary channel.
7338 if (typelen == 11 &&
7339 !memcmp(type, "exit-status", 11)) {
7341 ssh->exitcode = ssh_pkt_getuint32(pktin);
7342 logeventf(ssh, "Server sent command exit status %d",
7344 reply = SSH2_MSG_CHANNEL_SUCCESS;
7346 } else if (typelen == 11 &&
7347 !memcmp(type, "exit-signal", 11)) {
7349 int is_plausible = TRUE, is_int = FALSE;
7350 char *fmt_sig = "", *fmt_msg = "";
7352 int msglen = 0, core = FALSE;
7353 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7354 * provide an `int' for the signal, despite its
7355 * having been a `string' in the drafts of RFC 4254 since at
7356 * least 2001. (Fixed in session.c 1.147.) Try to
7357 * infer which we can safely parse it as. */
7359 unsigned char *p = pktin->body +
7361 long len = pktin->length - pktin->savedpos;
7362 unsigned long num = GET_32BIT(p); /* what is it? */
7363 /* If it's 0, it hardly matters; assume string */
7367 int maybe_int = FALSE, maybe_str = FALSE;
7368 #define CHECK_HYPOTHESIS(offset, result) \
7371 int q = toint(offset); \
7372 if (q >= 0 && q+4 <= len) { \
7373 q = toint(q + 4 + GET_32BIT(p+q)); \
7374 if (q >= 0 && q+4 <= len && \
7375 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7380 CHECK_HYPOTHESIS(4+1, maybe_int);
7381 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7382 #undef CHECK_HYPOTHESIS
7383 if (maybe_int && !maybe_str)
7385 else if (!maybe_int && maybe_str)
7388 /* Crikey. Either or neither. Panic. */
7389 is_plausible = FALSE;
7392 ssh->exitcode = 128; /* means `unknown signal' */
7395 /* Old non-standard OpenSSH. */
7396 int signum = ssh_pkt_getuint32(pktin);
7397 fmt_sig = dupprintf(" %d", signum);
7398 ssh->exitcode = 128 + signum;
7400 /* As per RFC 4254. */
7403 ssh_pkt_getstring(pktin, &sig, &siglen);
7404 /* Signal name isn't supposed to be blank, but
7405 * let's cope gracefully if it is. */
7407 fmt_sig = dupprintf(" \"%.*s\"",
7412 * Really hideous method of translating the
7413 * signal description back into a locally
7414 * meaningful number.
7419 #define TRANSLATE_SIGNAL(s) \
7420 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7421 ssh->exitcode = 128 + SIG ## s
7423 TRANSLATE_SIGNAL(ABRT);
7426 TRANSLATE_SIGNAL(ALRM);
7429 TRANSLATE_SIGNAL(FPE);
7432 TRANSLATE_SIGNAL(HUP);
7435 TRANSLATE_SIGNAL(ILL);
7438 TRANSLATE_SIGNAL(INT);
7441 TRANSLATE_SIGNAL(KILL);
7444 TRANSLATE_SIGNAL(PIPE);
7447 TRANSLATE_SIGNAL(QUIT);
7450 TRANSLATE_SIGNAL(SEGV);
7453 TRANSLATE_SIGNAL(TERM);
7456 TRANSLATE_SIGNAL(USR1);
7459 TRANSLATE_SIGNAL(USR2);
7461 #undef TRANSLATE_SIGNAL
7463 ssh->exitcode = 128;
7465 core = ssh2_pkt_getbool(pktin);
7466 ssh_pkt_getstring(pktin, &msg, &msglen);
7468 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7470 /* ignore lang tag */
7471 } /* else don't attempt to parse */
7472 logeventf(ssh, "Server exited on signal%s%s%s",
7473 fmt_sig, core ? " (core dumped)" : "",
7475 if (*fmt_sig) sfree(fmt_sig);
7476 if (*fmt_msg) sfree(fmt_msg);
7477 reply = SSH2_MSG_CHANNEL_SUCCESS;
7482 * This is a channel request we don't know
7483 * about, so we now either ignore the request
7484 * or respond with CHANNEL_FAILURE, depending
7487 reply = SSH2_MSG_CHANNEL_FAILURE;
7490 pktout = ssh2_pkt_init(reply);
7491 ssh2_pkt_adduint32(pktout, c->remoteid);
7492 ssh2_pkt_send(ssh, pktout);
7496 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7499 int typelen, want_reply;
7500 struct Packet *pktout;
7502 ssh_pkt_getstring(pktin, &type, &typelen);
7503 want_reply = ssh2_pkt_getbool(pktin);
7506 * We currently don't support any global requests
7507 * at all, so we either ignore the request or
7508 * respond with REQUEST_FAILURE, depending on
7512 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7513 ssh2_pkt_send(ssh, pktout);
7517 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7525 struct ssh_channel *c;
7526 unsigned remid, winsize, pktsize;
7527 struct Packet *pktout;
7529 ssh_pkt_getstring(pktin, &type, &typelen);
7530 c = snew(struct ssh_channel);
7533 remid = ssh_pkt_getuint32(pktin);
7534 winsize = ssh_pkt_getuint32(pktin);
7535 pktsize = ssh_pkt_getuint32(pktin);
7537 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7541 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7542 addrstr = snewn(peeraddrlen+1, char);
7543 memcpy(addrstr, peeraddr, peeraddrlen);
7544 addrstr[peeraddrlen] = '\0';
7545 peerport = ssh_pkt_getuint32(pktin);
7547 logeventf(ssh, "Received X11 connect request from %s:%d",
7550 if (!ssh->X11_fwd_enabled)
7551 error = "X11 forwarding is not enabled";
7552 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7553 addrstr, peerport, ssh->conf)) != NULL) {
7554 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7555 error = "Unable to open an X11 connection";
7557 logevent("Opening X11 forward connection succeeded");
7562 } else if (typelen == 15 &&
7563 !memcmp(type, "forwarded-tcpip", 15)) {
7564 struct ssh_rportfwd pf, *realpf;
7567 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
7568 pf.shost = dupprintf("%.*s", shostlen, shost);
7569 pf.sport = ssh_pkt_getuint32(pktin);
7570 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7571 peerport = ssh_pkt_getuint32(pktin);
7572 realpf = find234(ssh->rportfwds, &pf, NULL);
7573 logeventf(ssh, "Received remote port %s:%d open request "
7574 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
7577 if (realpf == NULL) {
7578 error = "Remote port is not recognised";
7580 const char *e = pfd_newconnect(&c->u.pfd.s,
7584 realpf->pfrec->addressfamily);
7585 logeventf(ssh, "Attempting to forward remote port to "
7586 "%s:%d", realpf->dhost, realpf->dport);
7588 logeventf(ssh, "Port open failed: %s", e);
7589 error = "Port open failed";
7591 logevent("Forwarded port opened successfully");
7592 c->type = CHAN_SOCKDATA;
7595 } else if (typelen == 22 &&
7596 !memcmp(type, "auth-agent@openssh.com", 22)) {
7597 if (!ssh->agentfwd_enabled)
7598 error = "Agent forwarding is not enabled";
7600 c->type = CHAN_AGENT; /* identify channel type */
7601 c->u.a.lensofar = 0;
7602 c->u.a.message = NULL;
7603 c->u.a.outstanding_requests = 0;
7606 error = "Unsupported channel type requested";
7609 c->remoteid = remid;
7610 c->halfopen = FALSE;
7612 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7613 ssh2_pkt_adduint32(pktout, c->remoteid);
7614 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7615 ssh2_pkt_addstring(pktout, error);
7616 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7617 ssh2_pkt_send(ssh, pktout);
7618 logeventf(ssh, "Rejected channel open: %s", error);
7621 ssh2_channel_init(c);
7622 c->v.v2.remwindow = winsize;
7623 c->v.v2.remmaxpkt = pktsize;
7624 add234(ssh->channels, c);
7625 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7626 ssh2_pkt_adduint32(pktout, c->remoteid);
7627 ssh2_pkt_adduint32(pktout, c->localid);
7628 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7629 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7630 ssh2_pkt_send(ssh, pktout);
7635 * Buffer banner messages for later display at some convenient point,
7636 * if we're going to display them.
7638 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7640 /* Arbitrary limit to prevent unbounded inflation of buffer */
7641 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7642 bufchain_size(&ssh->banner) <= 131072) {
7643 char *banner = NULL;
7645 ssh_pkt_getstring(pktin, &banner, &size);
7647 bufchain_add(&ssh->banner, banner, size);
7651 /* Helper function to deal with sending tty modes for "pty-req" */
7652 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7654 struct Packet *pktout = (struct Packet *)data;
7656 unsigned int arg = 0;
7657 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7658 if (i == lenof(ssh_ttymodes)) return;
7659 switch (ssh_ttymodes[i].type) {
7661 arg = ssh_tty_parse_specchar(val);
7664 arg = ssh_tty_parse_boolean(val);
7667 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7668 ssh2_pkt_adduint32(pktout, arg);
7671 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7674 struct ssh2_setup_x11_state {
7678 struct Packet *pktout;
7679 crStateP(ssh2_setup_x11_state, ctx);
7683 logevent("Requesting X11 forwarding");
7684 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7686 ssh2_pkt_addbool(pktout, 0); /* many connections */
7687 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7688 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7689 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7690 ssh2_pkt_send(ssh, pktout);
7692 /* Wait to be called back with either a response packet, or NULL
7693 * meaning clean up and free our data */
7697 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7698 logevent("X11 forwarding enabled");
7699 ssh->X11_fwd_enabled = TRUE;
7701 logevent("X11 forwarding refused");
7707 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7710 struct ssh2_setup_agent_state {
7714 struct Packet *pktout;
7715 crStateP(ssh2_setup_agent_state, ctx);
7719 logevent("Requesting OpenSSH-style agent forwarding");
7720 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7721 ssh2_setup_agent, s);
7722 ssh2_pkt_send(ssh, pktout);
7724 /* Wait to be called back with either a response packet, or NULL
7725 * meaning clean up and free our data */
7729 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7730 logevent("Agent forwarding enabled");
7731 ssh->agentfwd_enabled = TRUE;
7733 logevent("Agent forwarding refused");
7739 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7742 struct ssh2_setup_pty_state {
7746 struct Packet *pktout;
7747 crStateP(ssh2_setup_pty_state, ctx);
7751 /* Unpick the terminal-speed string. */
7752 /* XXX perhaps we should allow no speeds to be sent. */
7753 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7754 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7755 /* Build the pty request. */
7756 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7758 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7759 ssh2_pkt_adduint32(pktout, ssh->term_width);
7760 ssh2_pkt_adduint32(pktout, ssh->term_height);
7761 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7762 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7763 ssh2_pkt_addstring_start(pktout);
7764 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7765 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7766 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7767 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7768 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7769 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7770 ssh2_pkt_send(ssh, pktout);
7771 ssh->state = SSH_STATE_INTERMED;
7773 /* Wait to be called back with either a response packet, or NULL
7774 * meaning clean up and free our data */
7778 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7779 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7780 ssh->ospeed, ssh->ispeed);
7781 ssh->got_pty = TRUE;
7783 c_write_str(ssh, "Server refused to allocate pty\r\n");
7784 ssh->editing = ssh->echoing = 1;
7791 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7794 struct ssh2_setup_env_state {
7796 int num_env, env_left, env_ok;
7799 struct Packet *pktout;
7800 crStateP(ssh2_setup_env_state, ctx);
7805 * Send environment variables.
7807 * Simplest thing here is to send all the requests at once, and
7808 * then wait for a whole bunch of successes or failures.
7814 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7816 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7817 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7818 ssh2_pkt_addstring(pktout, key);
7819 ssh2_pkt_addstring(pktout, val);
7820 ssh2_pkt_send(ssh, pktout);
7825 logeventf(ssh, "Sent %d environment variables", s->num_env);
7830 s->env_left = s->num_env;
7832 while (s->env_left > 0) {
7833 /* Wait to be called back with either a response packet,
7834 * or NULL meaning clean up and free our data */
7836 if (!pktin) goto out;
7837 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7842 if (s->env_ok == s->num_env) {
7843 logevent("All environment variables successfully set");
7844 } else if (s->env_ok == 0) {
7845 logevent("All environment variables refused");
7846 c_write_str(ssh, "Server refused to set environment variables\r\n");
7848 logeventf(ssh, "%d environment variables refused",
7849 s->num_env - s->env_ok);
7850 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7858 * Handle the SSH-2 userauth and connection layers.
7860 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7862 do_ssh2_authconn(ssh, NULL, 0, pktin);
7865 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7868 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7871 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7872 struct Packet *pktin)
7874 struct do_ssh2_authconn_state {
7878 AUTH_TYPE_PUBLICKEY,
7879 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7880 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7882 AUTH_TYPE_GSSAPI, /* always QUIET */
7883 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7884 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7886 int done_service_req;
7887 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7888 int tried_pubkey_config, done_agent;
7893 int kbd_inter_refused;
7894 int we_are_in, userauth_success;
7895 prompts_t *cur_prompt;
7900 void *publickey_blob;
7901 int publickey_bloblen;
7902 int publickey_encrypted;
7903 char *publickey_algorithm;
7904 char *publickey_comment;
7905 unsigned char agent_request[5], *agent_response, *agentp;
7906 int agent_responselen;
7907 unsigned char *pkblob_in_agent;
7909 char *pkblob, *alg, *commentp;
7910 int pklen, alglen, commentlen;
7911 int siglen, retlen, len;
7912 char *q, *agentreq, *ret;
7914 struct Packet *pktout;
7917 struct ssh_gss_library *gsslib;
7918 Ssh_gss_ctx gss_ctx;
7919 Ssh_gss_buf gss_buf;
7920 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7921 Ssh_gss_name gss_srv_name;
7922 Ssh_gss_stat gss_stat;
7925 crState(do_ssh2_authconn_state);
7929 /* Register as a handler for all the messages this coroutine handles. */
7930 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7931 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7932 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7933 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7934 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7935 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7936 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7937 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7938 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7939 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7940 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7941 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7942 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7943 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7944 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7945 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7947 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7948 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7949 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7951 s->done_service_req = FALSE;
7952 s->we_are_in = s->userauth_success = FALSE;
7954 s->tried_gssapi = FALSE;
7957 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7959 * Request userauth protocol, and await a response to it.
7961 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7962 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7963 ssh2_pkt_send(ssh, s->pktout);
7964 crWaitUntilV(pktin);
7965 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7966 s->done_service_req = TRUE;
7968 if (!s->done_service_req) {
7970 * Request connection protocol directly, without authentication.
7972 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7973 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7974 ssh2_pkt_send(ssh, s->pktout);
7975 crWaitUntilV(pktin);
7976 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7977 s->we_are_in = TRUE; /* no auth required */
7979 bombout(("Server refused service request"));
7984 /* Arrange to be able to deal with any BANNERs that come in.
7985 * (We do this now as packets may come in during the next bit.) */
7986 bufchain_init(&ssh->banner);
7987 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7988 ssh2_msg_userauth_banner;
7991 * Misc one-time setup for authentication.
7993 s->publickey_blob = NULL;
7994 if (!s->we_are_in) {
7997 * Load the public half of any configured public key file
8000 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8001 if (!filename_is_null(s->keyfile)) {
8003 logeventf(ssh, "Reading private key file \"%.150s\"",
8004 filename_to_str(s->keyfile));
8005 keytype = key_type(s->keyfile);
8006 if (keytype == SSH_KEYTYPE_SSH2) {
8009 ssh2_userkey_loadpub(s->keyfile,
8010 &s->publickey_algorithm,
8011 &s->publickey_bloblen,
8012 &s->publickey_comment, &error);
8013 if (s->publickey_blob) {
8014 s->publickey_encrypted =
8015 ssh2_userkey_encrypted(s->keyfile, NULL);
8018 logeventf(ssh, "Unable to load private key (%s)",
8020 msgbuf = dupprintf("Unable to load private key file "
8021 "\"%.150s\" (%s)\r\n",
8022 filename_to_str(s->keyfile),
8024 c_write_str(ssh, msgbuf);
8029 logeventf(ssh, "Unable to use this key file (%s)",
8030 key_type_to_str(keytype));
8031 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8033 filename_to_str(s->keyfile),
8034 key_type_to_str(keytype));
8035 c_write_str(ssh, msgbuf);
8037 s->publickey_blob = NULL;
8042 * Find out about any keys Pageant has (but if there's a
8043 * public key configured, filter out all others).
8046 s->agent_response = NULL;
8047 s->pkblob_in_agent = NULL;
8048 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8052 logevent("Pageant is running. Requesting keys.");
8054 /* Request the keys held by the agent. */
8055 PUT_32BIT(s->agent_request, 1);
8056 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8057 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8058 ssh_agent_callback, ssh)) {
8062 bombout(("Unexpected data from server while"
8063 " waiting for agent response"));
8066 } while (pktin || inlen > 0);
8067 r = ssh->agent_response;
8068 s->agent_responselen = ssh->agent_response_len;
8070 s->agent_response = (unsigned char *) r;
8071 if (s->agent_response && s->agent_responselen >= 5 &&
8072 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8075 p = s->agent_response + 5;
8076 s->nkeys = toint(GET_32BIT(p));
8079 * Vet the Pageant response to ensure that the key
8080 * count and blob lengths make sense.
8083 logeventf(ssh, "Pageant response contained a negative"
8084 " key count %d", s->nkeys);
8086 goto done_agent_query;
8088 unsigned char *q = p + 4;
8089 int lenleft = s->agent_responselen - 5 - 4;
8091 for (keyi = 0; keyi < s->nkeys; keyi++) {
8092 int bloblen, commentlen;
8094 logeventf(ssh, "Pageant response was truncated");
8096 goto done_agent_query;
8098 bloblen = toint(GET_32BIT(q));
8099 if (bloblen < 0 || bloblen > lenleft) {
8100 logeventf(ssh, "Pageant response was truncated");
8102 goto done_agent_query;
8104 lenleft -= 4 + bloblen;
8106 commentlen = toint(GET_32BIT(q));
8107 if (commentlen < 0 || commentlen > lenleft) {
8108 logeventf(ssh, "Pageant response was truncated");
8110 goto done_agent_query;
8112 lenleft -= 4 + commentlen;
8113 q += 4 + commentlen;
8118 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8119 if (s->publickey_blob) {
8120 /* See if configured key is in agent. */
8121 for (keyi = 0; keyi < s->nkeys; keyi++) {
8122 s->pklen = toint(GET_32BIT(p));
8123 if (s->pklen == s->publickey_bloblen &&
8124 !memcmp(p+4, s->publickey_blob,
8125 s->publickey_bloblen)) {
8126 logeventf(ssh, "Pageant key #%d matches "
8127 "configured key file", keyi);
8129 s->pkblob_in_agent = p;
8133 p += toint(GET_32BIT(p)) + 4; /* comment */
8135 if (!s->pkblob_in_agent) {
8136 logevent("Configured key file not in Pageant");
8141 logevent("Failed to get reply from Pageant");
8149 * We repeat this whole loop, including the username prompt,
8150 * until we manage a successful authentication. If the user
8151 * types the wrong _password_, they can be sent back to the
8152 * beginning to try another username, if this is configured on.
8153 * (If they specify a username in the config, they are never
8154 * asked, even if they do give a wrong password.)
8156 * I think this best serves the needs of
8158 * - the people who have no configuration, no keys, and just
8159 * want to try repeated (username,password) pairs until they
8160 * type both correctly
8162 * - people who have keys and configuration but occasionally
8163 * need to fall back to passwords
8165 * - people with a key held in Pageant, who might not have
8166 * logged in to a particular machine before; so they want to
8167 * type a username, and then _either_ their key will be
8168 * accepted, _or_ they will type a password. If they mistype
8169 * the username they will want to be able to get back and
8172 s->got_username = FALSE;
8173 while (!s->we_are_in) {
8177 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8179 * We got a username last time round this loop, and
8180 * with change_username turned off we don't try to get
8183 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8184 int ret; /* need not be kept over crReturn */
8185 s->cur_prompt = new_prompts(ssh->frontend);
8186 s->cur_prompt->to_server = TRUE;
8187 s->cur_prompt->name = dupstr("SSH login name");
8188 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8189 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8192 crWaitUntilV(!pktin);
8193 ret = get_userpass_input(s->cur_prompt, in, inlen);
8198 * get_userpass_input() failed to get a username.
8201 free_prompts(s->cur_prompt);
8202 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8205 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8206 free_prompts(s->cur_prompt);
8209 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8210 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8211 c_write_str(ssh, stuff);
8215 s->got_username = TRUE;
8218 * Send an authentication request using method "none": (a)
8219 * just in case it succeeds, and (b) so that we know what
8220 * authentication methods we can usefully try next.
8222 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8224 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8225 ssh2_pkt_addstring(s->pktout, ssh->username);
8226 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8227 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8228 ssh2_pkt_send(ssh, s->pktout);
8229 s->type = AUTH_TYPE_NONE;
8231 s->we_are_in = FALSE;
8233 s->tried_pubkey_config = FALSE;
8234 s->kbd_inter_refused = FALSE;
8236 /* Reset agent request state. */
8237 s->done_agent = FALSE;
8238 if (s->agent_response) {
8239 if (s->pkblob_in_agent) {
8240 s->agentp = s->pkblob_in_agent;
8242 s->agentp = s->agent_response + 5 + 4;
8248 char *methods = NULL;
8252 * Wait for the result of the last authentication request.
8255 crWaitUntilV(pktin);
8257 * Now is a convenient point to spew any banner material
8258 * that we've accumulated. (This should ensure that when
8259 * we exit the auth loop, we haven't any left to deal
8263 int size = bufchain_size(&ssh->banner);
8265 * Don't show the banner if we're operating in
8266 * non-verbose non-interactive mode. (It's probably
8267 * a script, which means nobody will read the
8268 * banner _anyway_, and moreover the printing of
8269 * the banner will screw up processing on the
8270 * output of (say) plink.)
8272 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8273 char *banner = snewn(size, char);
8274 bufchain_fetch(&ssh->banner, banner, size);
8275 c_write_untrusted(ssh, banner, size);
8278 bufchain_clear(&ssh->banner);
8280 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8281 logevent("Access granted");
8282 s->we_are_in = s->userauth_success = TRUE;
8286 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8287 bombout(("Strange packet received during authentication: "
8288 "type %d", pktin->type));
8295 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8296 * we can look at the string in it and know what we can
8297 * helpfully try next.
8299 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8300 ssh_pkt_getstring(pktin, &methods, &methlen);
8301 if (!ssh2_pkt_getbool(pktin)) {
8303 * We have received an unequivocal Access
8304 * Denied. This can translate to a variety of
8305 * messages, or no message at all.
8307 * For forms of authentication which are attempted
8308 * implicitly, by which I mean without printing
8309 * anything in the window indicating that we're
8310 * trying them, we should never print 'Access
8313 * If we do print a message saying that we're
8314 * attempting some kind of authentication, it's OK
8315 * to print a followup message saying it failed -
8316 * but the message may sometimes be more specific
8317 * than simply 'Access denied'.
8319 * Additionally, if we'd just tried password
8320 * authentication, we should break out of this
8321 * whole loop so as to go back to the username
8322 * prompt (iff we're configured to allow
8323 * username change attempts).
8325 if (s->type == AUTH_TYPE_NONE) {
8327 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8328 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8329 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8330 c_write_str(ssh, "Server refused our key\r\n");
8331 logevent("Server refused our key");
8332 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8333 /* This _shouldn't_ happen except by a
8334 * protocol bug causing client and server to
8335 * disagree on what is a correct signature. */
8336 c_write_str(ssh, "Server refused public-key signature"
8337 " despite accepting key!\r\n");
8338 logevent("Server refused public-key signature"
8339 " despite accepting key!");
8340 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8341 /* quiet, so no c_write */
8342 logevent("Server refused keyboard-interactive authentication");
8343 } else if (s->type==AUTH_TYPE_GSSAPI) {
8344 /* always quiet, so no c_write */
8345 /* also, the code down in the GSSAPI block has
8346 * already logged this in the Event Log */
8347 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8348 logevent("Keyboard-interactive authentication failed");
8349 c_write_str(ssh, "Access denied\r\n");
8351 assert(s->type == AUTH_TYPE_PASSWORD);
8352 logevent("Password authentication failed");
8353 c_write_str(ssh, "Access denied\r\n");
8355 if (conf_get_int(ssh->conf, CONF_change_username)) {
8356 /* XXX perhaps we should allow
8357 * keyboard-interactive to do this too? */
8358 s->we_are_in = FALSE;
8363 c_write_str(ssh, "Further authentication required\r\n");
8364 logevent("Further authentication required");
8368 in_commasep_string("publickey", methods, methlen);
8370 in_commasep_string("password", methods, methlen);
8371 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8372 in_commasep_string("keyboard-interactive", methods, methlen);
8375 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8376 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8377 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8378 ssh->gsslibs->nlibraries > 0;
8382 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8384 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8387 * Attempt public-key authentication using a key from Pageant.
8390 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8392 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8394 /* Unpack key from agent response */
8395 s->pklen = toint(GET_32BIT(s->agentp));
8397 s->pkblob = (char *)s->agentp;
8398 s->agentp += s->pklen;
8399 s->alglen = toint(GET_32BIT(s->pkblob));
8400 s->alg = s->pkblob + 4;
8401 s->commentlen = toint(GET_32BIT(s->agentp));
8403 s->commentp = (char *)s->agentp;
8404 s->agentp += s->commentlen;
8405 /* s->agentp now points at next key, if any */
8407 /* See if server will accept it */
8408 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8409 ssh2_pkt_addstring(s->pktout, ssh->username);
8410 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8411 /* service requested */
8412 ssh2_pkt_addstring(s->pktout, "publickey");
8414 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8415 ssh2_pkt_addstring_start(s->pktout);
8416 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8417 ssh2_pkt_addstring_start(s->pktout);
8418 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8419 ssh2_pkt_send(ssh, s->pktout);
8420 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8422 crWaitUntilV(pktin);
8423 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8425 /* Offer of key refused. */
8432 if (flags & FLAG_VERBOSE) {
8433 c_write_str(ssh, "Authenticating with "
8435 c_write(ssh, s->commentp, s->commentlen);
8436 c_write_str(ssh, "\" from agent\r\n");
8440 * Server is willing to accept the key.
8441 * Construct a SIGN_REQUEST.
8443 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8444 ssh2_pkt_addstring(s->pktout, ssh->username);
8445 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8446 /* service requested */
8447 ssh2_pkt_addstring(s->pktout, "publickey");
8449 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8450 ssh2_pkt_addstring_start(s->pktout);
8451 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8452 ssh2_pkt_addstring_start(s->pktout);
8453 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8455 /* Ask agent for signature. */
8456 s->siglen = s->pktout->length - 5 + 4 +
8457 ssh->v2_session_id_len;
8458 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8460 s->len = 1; /* message type */
8461 s->len += 4 + s->pklen; /* key blob */
8462 s->len += 4 + s->siglen; /* data to sign */
8463 s->len += 4; /* flags */
8464 s->agentreq = snewn(4 + s->len, char);
8465 PUT_32BIT(s->agentreq, s->len);
8466 s->q = s->agentreq + 4;
8467 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8468 PUT_32BIT(s->q, s->pklen);
8470 memcpy(s->q, s->pkblob, s->pklen);
8472 PUT_32BIT(s->q, s->siglen);
8474 /* Now the data to be signed... */
8475 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8476 PUT_32BIT(s->q, ssh->v2_session_id_len);
8479 memcpy(s->q, ssh->v2_session_id,
8480 ssh->v2_session_id_len);
8481 s->q += ssh->v2_session_id_len;
8482 memcpy(s->q, s->pktout->data + 5,
8483 s->pktout->length - 5);
8484 s->q += s->pktout->length - 5;
8485 /* And finally the (zero) flags word. */
8487 if (!agent_query(s->agentreq, s->len + 4,
8489 ssh_agent_callback, ssh)) {
8493 bombout(("Unexpected data from server"
8494 " while waiting for agent"
8498 } while (pktin || inlen > 0);
8499 vret = ssh->agent_response;
8500 s->retlen = ssh->agent_response_len;
8505 if (s->retlen >= 9 &&
8506 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8507 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8508 logevent("Sending Pageant's response");
8509 ssh2_add_sigblob(ssh, s->pktout,
8510 s->pkblob, s->pklen,
8512 GET_32BIT(s->ret + 5));
8513 ssh2_pkt_send(ssh, s->pktout);
8514 s->type = AUTH_TYPE_PUBLICKEY;
8516 /* FIXME: less drastic response */
8517 bombout(("Pageant failed to answer challenge"));
8523 /* Do we have any keys left to try? */
8524 if (s->pkblob_in_agent) {
8525 s->done_agent = TRUE;
8526 s->tried_pubkey_config = TRUE;
8529 if (s->keyi >= s->nkeys)
8530 s->done_agent = TRUE;
8533 } else if (s->can_pubkey && s->publickey_blob &&
8534 !s->tried_pubkey_config) {
8536 struct ssh2_userkey *key; /* not live over crReturn */
8537 char *passphrase; /* not live over crReturn */
8539 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8541 s->tried_pubkey_config = TRUE;
8544 * Try the public key supplied in the configuration.
8546 * First, offer the public blob to see if the server is
8547 * willing to accept it.
8549 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8550 ssh2_pkt_addstring(s->pktout, ssh->username);
8551 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8552 /* service requested */
8553 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8554 ssh2_pkt_addbool(s->pktout, FALSE);
8555 /* no signature included */
8556 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8557 ssh2_pkt_addstring_start(s->pktout);
8558 ssh2_pkt_addstring_data(s->pktout,
8559 (char *)s->publickey_blob,
8560 s->publickey_bloblen);
8561 ssh2_pkt_send(ssh, s->pktout);
8562 logevent("Offered public key");
8564 crWaitUntilV(pktin);
8565 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8566 /* Key refused. Give up. */
8567 s->gotit = TRUE; /* reconsider message next loop */
8568 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8569 continue; /* process this new message */
8571 logevent("Offer of public key accepted");
8574 * Actually attempt a serious authentication using
8577 if (flags & FLAG_VERBOSE) {
8578 c_write_str(ssh, "Authenticating with public key \"");
8579 c_write_str(ssh, s->publickey_comment);
8580 c_write_str(ssh, "\"\r\n");
8584 const char *error; /* not live over crReturn */
8585 if (s->publickey_encrypted) {
8587 * Get a passphrase from the user.
8589 int ret; /* need not be kept over crReturn */
8590 s->cur_prompt = new_prompts(ssh->frontend);
8591 s->cur_prompt->to_server = FALSE;
8592 s->cur_prompt->name = dupstr("SSH key passphrase");
8593 add_prompt(s->cur_prompt,
8594 dupprintf("Passphrase for key \"%.100s\": ",
8595 s->publickey_comment),
8597 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8600 crWaitUntilV(!pktin);
8601 ret = get_userpass_input(s->cur_prompt,
8606 /* Failed to get a passphrase. Terminate. */
8607 free_prompts(s->cur_prompt);
8608 ssh_disconnect(ssh, NULL,
8609 "Unable to authenticate",
8610 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8615 dupstr(s->cur_prompt->prompts[0]->result);
8616 free_prompts(s->cur_prompt);
8618 passphrase = NULL; /* no passphrase needed */
8622 * Try decrypting the key.
8624 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8625 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8627 /* burn the evidence */
8628 smemclr(passphrase, strlen(passphrase));
8631 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8633 (key == SSH2_WRONG_PASSPHRASE)) {
8634 c_write_str(ssh, "Wrong passphrase\r\n");
8636 /* and loop again */
8638 c_write_str(ssh, "Unable to load private key (");
8639 c_write_str(ssh, error);
8640 c_write_str(ssh, ")\r\n");
8642 break; /* try something else */
8648 unsigned char *pkblob, *sigblob, *sigdata;
8649 int pkblob_len, sigblob_len, sigdata_len;
8653 * We have loaded the private key and the server
8654 * has announced that it's willing to accept it.
8655 * Hallelujah. Generate a signature and send it.
8657 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8658 ssh2_pkt_addstring(s->pktout, ssh->username);
8659 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8660 /* service requested */
8661 ssh2_pkt_addstring(s->pktout, "publickey");
8663 ssh2_pkt_addbool(s->pktout, TRUE);
8664 /* signature follows */
8665 ssh2_pkt_addstring(s->pktout, key->alg->name);
8666 pkblob = key->alg->public_blob(key->data,
8668 ssh2_pkt_addstring_start(s->pktout);
8669 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8673 * The data to be signed is:
8677 * followed by everything so far placed in the
8680 sigdata_len = s->pktout->length - 5 + 4 +
8681 ssh->v2_session_id_len;
8682 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8684 sigdata = snewn(sigdata_len, unsigned char);
8686 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8687 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8690 memcpy(sigdata+p, ssh->v2_session_id,
8691 ssh->v2_session_id_len);
8692 p += ssh->v2_session_id_len;
8693 memcpy(sigdata+p, s->pktout->data + 5,
8694 s->pktout->length - 5);
8695 p += s->pktout->length - 5;
8696 assert(p == sigdata_len);
8697 sigblob = key->alg->sign(key->data, (char *)sigdata,
8698 sigdata_len, &sigblob_len);
8699 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8700 sigblob, sigblob_len);
8705 ssh2_pkt_send(ssh, s->pktout);
8706 logevent("Sent public key signature");
8707 s->type = AUTH_TYPE_PUBLICKEY;
8708 key->alg->freekey(key->data);
8712 } else if (s->can_gssapi && !s->tried_gssapi) {
8714 /* GSSAPI Authentication */
8719 s->type = AUTH_TYPE_GSSAPI;
8720 s->tried_gssapi = TRUE;
8722 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8725 * Pick the highest GSS library on the preference
8731 for (i = 0; i < ngsslibs; i++) {
8732 int want_id = conf_get_int_int(ssh->conf,
8733 CONF_ssh_gsslist, i);
8734 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8735 if (ssh->gsslibs->libraries[j].id == want_id) {
8736 s->gsslib = &ssh->gsslibs->libraries[j];
8737 goto got_gsslib; /* double break */
8742 * We always expect to have found something in
8743 * the above loop: we only came here if there
8744 * was at least one viable GSS library, and the
8745 * preference list should always mention
8746 * everything and only change the order.
8751 if (s->gsslib->gsslogmsg)
8752 logevent(s->gsslib->gsslogmsg);
8754 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8755 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8756 ssh2_pkt_addstring(s->pktout, ssh->username);
8757 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8758 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8759 logevent("Attempting GSSAPI authentication");
8761 /* add mechanism info */
8762 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8764 /* number of GSSAPI mechanisms */
8765 ssh2_pkt_adduint32(s->pktout,1);
8767 /* length of OID + 2 */
8768 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8769 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8772 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8774 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8776 ssh2_pkt_send(ssh, s->pktout);
8777 crWaitUntilV(pktin);
8778 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8779 logevent("GSSAPI authentication request refused");
8783 /* check returned packet ... */
8785 ssh_pkt_getstring(pktin, &data, &len);
8786 s->gss_rcvtok.value = data;
8787 s->gss_rcvtok.length = len;
8788 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8789 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8790 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8791 memcmp((char *)s->gss_rcvtok.value + 2,
8792 s->gss_buf.value,s->gss_buf.length) ) {
8793 logevent("GSSAPI authentication - wrong response from server");
8797 /* now start running */
8798 s->gss_stat = s->gsslib->import_name(s->gsslib,
8801 if (s->gss_stat != SSH_GSS_OK) {
8802 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8803 logevent("GSSAPI import name failed - Bad service name");
8805 logevent("GSSAPI import name failed");
8809 /* fetch TGT into GSS engine */
8810 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8812 if (s->gss_stat != SSH_GSS_OK) {
8813 logevent("GSSAPI authentication failed to get credentials");
8814 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8818 /* initial tokens are empty */
8819 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8820 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8822 /* now enter the loop */
8824 s->gss_stat = s->gsslib->init_sec_context
8828 conf_get_int(ssh->conf, CONF_gssapifwd),
8832 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8833 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8834 logevent("GSSAPI authentication initialisation failed");
8836 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8837 &s->gss_buf) == SSH_GSS_OK) {
8838 logevent(s->gss_buf.value);
8839 sfree(s->gss_buf.value);
8844 logevent("GSSAPI authentication initialised");
8846 /* Client and server now exchange tokens until GSSAPI
8847 * no longer says CONTINUE_NEEDED */
8849 if (s->gss_sndtok.length != 0) {
8850 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8851 ssh_pkt_addstring_start(s->pktout);
8852 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8853 ssh2_pkt_send(ssh, s->pktout);
8854 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8857 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8858 crWaitUntilV(pktin);
8859 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8860 logevent("GSSAPI authentication - bad server response");
8861 s->gss_stat = SSH_GSS_FAILURE;
8864 ssh_pkt_getstring(pktin, &data, &len);
8865 s->gss_rcvtok.value = data;
8866 s->gss_rcvtok.length = len;
8868 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8870 if (s->gss_stat != SSH_GSS_OK) {
8871 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8872 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8875 logevent("GSSAPI authentication loop finished OK");
8877 /* Now send the MIC */
8879 s->pktout = ssh2_pkt_init(0);
8880 micoffset = s->pktout->length;
8881 ssh_pkt_addstring_start(s->pktout);
8882 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8883 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8884 ssh_pkt_addstring(s->pktout, ssh->username);
8885 ssh_pkt_addstring(s->pktout, "ssh-connection");
8886 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8888 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8889 s->gss_buf.length = s->pktout->length - micoffset;
8891 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8892 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8893 ssh_pkt_addstring_start(s->pktout);
8894 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8895 ssh2_pkt_send(ssh, s->pktout);
8896 s->gsslib->free_mic(s->gsslib, &mic);
8900 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8901 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8904 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8907 * Keyboard-interactive authentication.
8910 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8912 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8914 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8915 ssh2_pkt_addstring(s->pktout, ssh->username);
8916 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8917 /* service requested */
8918 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8920 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8921 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8922 ssh2_pkt_send(ssh, s->pktout);
8924 logevent("Attempting keyboard-interactive authentication");
8926 crWaitUntilV(pktin);
8927 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8928 /* Server is not willing to do keyboard-interactive
8929 * at all (or, bizarrely but legally, accepts the
8930 * user without actually issuing any prompts).
8931 * Give up on it entirely. */
8933 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8934 s->kbd_inter_refused = TRUE; /* don't try it again */
8939 * Loop while the server continues to send INFO_REQUESTs.
8941 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8943 char *name, *inst, *lang;
8944 int name_len, inst_len, lang_len;
8948 * We've got a fresh USERAUTH_INFO_REQUEST.
8949 * Get the preamble and start building a prompt.
8951 ssh_pkt_getstring(pktin, &name, &name_len);
8952 ssh_pkt_getstring(pktin, &inst, &inst_len);
8953 ssh_pkt_getstring(pktin, &lang, &lang_len);
8954 s->cur_prompt = new_prompts(ssh->frontend);
8955 s->cur_prompt->to_server = TRUE;
8958 * Get any prompt(s) from the packet.
8960 s->num_prompts = ssh_pkt_getuint32(pktin);
8961 for (i = 0; i < s->num_prompts; i++) {
8965 static char noprompt[] =
8966 "<server failed to send prompt>: ";
8968 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8969 echo = ssh2_pkt_getbool(pktin);
8972 prompt_len = lenof(noprompt)-1;
8974 add_prompt(s->cur_prompt,
8975 dupprintf("%.*s", prompt_len, prompt),
8980 /* FIXME: better prefix to distinguish from
8982 s->cur_prompt->name =
8983 dupprintf("SSH server: %.*s", name_len, name);
8984 s->cur_prompt->name_reqd = TRUE;
8986 s->cur_prompt->name =
8987 dupstr("SSH server authentication");
8988 s->cur_prompt->name_reqd = FALSE;
8990 /* We add a prefix to try to make it clear that a prompt
8991 * has come from the server.
8992 * FIXME: ugly to print "Using..." in prompt _every_
8993 * time round. Can this be done more subtly? */
8994 /* Special case: for reasons best known to themselves,
8995 * some servers send k-i requests with no prompts and
8996 * nothing to display. Keep quiet in this case. */
8997 if (s->num_prompts || name_len || inst_len) {
8998 s->cur_prompt->instruction =
8999 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9000 inst_len ? "\n" : "", inst_len, inst);
9001 s->cur_prompt->instr_reqd = TRUE;
9003 s->cur_prompt->instr_reqd = FALSE;
9007 * Display any instructions, and get the user's
9011 int ret; /* not live over crReturn */
9012 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9015 crWaitUntilV(!pktin);
9016 ret = get_userpass_input(s->cur_prompt, in, inlen);
9021 * Failed to get responses. Terminate.
9023 free_prompts(s->cur_prompt);
9024 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9025 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9032 * Send the response(s) to the server.
9034 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9035 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9036 for (i=0; i < s->num_prompts; i++) {
9037 ssh2_pkt_addstring(s->pktout,
9038 s->cur_prompt->prompts[i]->result);
9040 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9043 * Free the prompts structure from this iteration.
9044 * If there's another, a new one will be allocated
9045 * when we return to the top of this while loop.
9047 free_prompts(s->cur_prompt);
9050 * Get the next packet in case it's another
9053 crWaitUntilV(pktin);
9058 * We should have SUCCESS or FAILURE now.
9062 } else if (s->can_passwd) {
9065 * Plain old password authentication.
9067 int ret; /* not live over crReturn */
9068 int changereq_first_time; /* not live over crReturn */
9070 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9072 s->cur_prompt = new_prompts(ssh->frontend);
9073 s->cur_prompt->to_server = TRUE;
9074 s->cur_prompt->name = dupstr("SSH password");
9075 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9080 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9083 crWaitUntilV(!pktin);
9084 ret = get_userpass_input(s->cur_prompt, in, inlen);
9089 * Failed to get responses. Terminate.
9091 free_prompts(s->cur_prompt);
9092 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9093 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9098 * Squirrel away the password. (We may need it later if
9099 * asked to change it.)
9101 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9102 free_prompts(s->cur_prompt);
9105 * Send the password packet.
9107 * We pad out the password packet to 256 bytes to make
9108 * it harder for an attacker to find the length of the
9111 * Anyone using a password longer than 256 bytes
9112 * probably doesn't have much to worry about from
9113 * people who find out how long their password is!
9115 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9116 ssh2_pkt_addstring(s->pktout, ssh->username);
9117 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9118 /* service requested */
9119 ssh2_pkt_addstring(s->pktout, "password");
9120 ssh2_pkt_addbool(s->pktout, FALSE);
9121 ssh2_pkt_addstring(s->pktout, s->password);
9122 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9123 logevent("Sent password");
9124 s->type = AUTH_TYPE_PASSWORD;
9127 * Wait for next packet, in case it's a password change
9130 crWaitUntilV(pktin);
9131 changereq_first_time = TRUE;
9133 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9136 * We're being asked for a new password
9137 * (perhaps not for the first time).
9138 * Loop until the server accepts it.
9141 int got_new = FALSE; /* not live over crReturn */
9142 char *prompt; /* not live over crReturn */
9143 int prompt_len; /* not live over crReturn */
9147 if (changereq_first_time)
9148 msg = "Server requested password change";
9150 msg = "Server rejected new password";
9152 c_write_str(ssh, msg);
9153 c_write_str(ssh, "\r\n");
9156 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9158 s->cur_prompt = new_prompts(ssh->frontend);
9159 s->cur_prompt->to_server = TRUE;
9160 s->cur_prompt->name = dupstr("New SSH password");
9161 s->cur_prompt->instruction =
9162 dupprintf("%.*s", prompt_len, prompt);
9163 s->cur_prompt->instr_reqd = TRUE;
9165 * There's no explicit requirement in the protocol
9166 * for the "old" passwords in the original and
9167 * password-change messages to be the same, and
9168 * apparently some Cisco kit supports password change
9169 * by the user entering a blank password originally
9170 * and the real password subsequently, so,
9171 * reluctantly, we prompt for the old password again.
9173 * (On the other hand, some servers don't even bother
9174 * to check this field.)
9176 add_prompt(s->cur_prompt,
9177 dupstr("Current password (blank for previously entered password): "),
9179 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9181 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9185 * Loop until the user manages to enter the same
9190 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9193 crWaitUntilV(!pktin);
9194 ret = get_userpass_input(s->cur_prompt, in, inlen);
9199 * Failed to get responses. Terminate.
9201 /* burn the evidence */
9202 free_prompts(s->cur_prompt);
9203 smemclr(s->password, strlen(s->password));
9205 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9206 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9212 * If the user specified a new original password
9213 * (IYSWIM), overwrite any previously specified
9215 * (A side effect is that the user doesn't have to
9216 * re-enter it if they louse up the new password.)
9218 if (s->cur_prompt->prompts[0]->result[0]) {
9219 smemclr(s->password, strlen(s->password));
9220 /* burn the evidence */
9223 dupstr(s->cur_prompt->prompts[0]->result);
9227 * Check the two new passwords match.
9229 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9230 s->cur_prompt->prompts[2]->result)
9233 /* They don't. Silly user. */
9234 c_write_str(ssh, "Passwords do not match\r\n");
9239 * Send the new password (along with the old one).
9240 * (see above for padding rationale)
9242 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9243 ssh2_pkt_addstring(s->pktout, ssh->username);
9244 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9245 /* service requested */
9246 ssh2_pkt_addstring(s->pktout, "password");
9247 ssh2_pkt_addbool(s->pktout, TRUE);
9248 ssh2_pkt_addstring(s->pktout, s->password);
9249 ssh2_pkt_addstring(s->pktout,
9250 s->cur_prompt->prompts[1]->result);
9251 free_prompts(s->cur_prompt);
9252 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9253 logevent("Sent new password");
9256 * Now see what the server has to say about it.
9257 * (If it's CHANGEREQ again, it's not happy with the
9260 crWaitUntilV(pktin);
9261 changereq_first_time = FALSE;
9266 * We need to reexamine the current pktin at the top
9267 * of the loop. Either:
9268 * - we weren't asked to change password at all, in
9269 * which case it's a SUCCESS or FAILURE with the
9271 * - we sent a new password, and the server was
9272 * either OK with it (SUCCESS or FAILURE w/partial
9273 * success) or unhappy with the _old_ password
9274 * (FAILURE w/o partial success)
9275 * In any of these cases, we go back to the top of
9276 * the loop and start again.
9281 * We don't need the old password any more, in any
9282 * case. Burn the evidence.
9284 smemclr(s->password, strlen(s->password));
9288 char *str = dupprintf("No supported authentication methods available"
9289 " (server sent: %.*s)",
9292 ssh_disconnect(ssh, str,
9293 "No supported authentication methods available",
9294 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9304 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9306 /* Clear up various bits and pieces from authentication. */
9307 if (s->publickey_blob) {
9308 sfree(s->publickey_blob);
9309 sfree(s->publickey_comment);
9311 if (s->agent_response)
9312 sfree(s->agent_response);
9314 if (s->userauth_success) {
9316 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9317 * packets since. Signal the transport layer to consider enacting
9318 * delayed compression.
9320 * (Relying on we_are_in is not sufficient, as
9321 * draft-miller-secsh-compression-delayed is quite clear that it
9322 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9323 * become set for other reasons.)
9325 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9329 * Now the connection protocol has started, one way or another.
9332 ssh->channels = newtree234(ssh_channelcmp);
9335 * Set up handlers for some connection protocol messages, so we
9336 * don't have to handle them repeatedly in this coroutine.
9338 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9339 ssh2_msg_channel_window_adjust;
9340 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9341 ssh2_msg_global_request;
9344 * Create the main session channel.
9346 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9347 ssh->mainchan = NULL;
9349 ssh->mainchan = snew(struct ssh_channel);
9350 ssh->mainchan->ssh = ssh;
9351 ssh2_channel_init(ssh->mainchan);
9353 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9355 * Just start a direct-tcpip channel and use it as the main
9358 ssh_send_port_open(ssh->mainchan,
9359 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9360 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9364 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9365 logevent("Opening session as main channel");
9366 ssh2_pkt_send(ssh, s->pktout);
9367 ssh->ncmode = FALSE;
9369 crWaitUntilV(pktin);
9370 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9371 bombout(("Server refused to open channel"));
9373 /* FIXME: error data comes back in FAILURE packet */
9375 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9376 bombout(("Server's channel confirmation cited wrong channel"));
9379 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9380 ssh->mainchan->halfopen = FALSE;
9381 ssh->mainchan->type = CHAN_MAINSESSION;
9382 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9383 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9384 add234(ssh->channels, ssh->mainchan);
9385 update_specials_menu(ssh->frontend);
9386 logevent("Opened main channel");
9390 * Now we have a channel, make dispatch table entries for
9391 * general channel-based messages.
9393 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9394 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9395 ssh2_msg_channel_data;
9396 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9397 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9398 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9399 ssh2_msg_channel_open_confirmation;
9400 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9401 ssh2_msg_channel_open_failure;
9402 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9403 ssh2_msg_channel_request;
9404 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9405 ssh2_msg_channel_open;
9406 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9407 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9410 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9412 * This message indicates to the server that we promise
9413 * not to try to run any other channel in parallel with
9414 * this one, so it's safe for it to advertise a very large
9415 * window and leave the flow control to TCP.
9417 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9418 "simple@putty.projects.tartarus.org",
9420 ssh2_pkt_send(ssh, s->pktout);
9424 * Enable port forwardings.
9426 ssh_setup_portfwd(ssh, ssh->conf);
9428 if (ssh->mainchan && !ssh->ncmode) {
9430 * Send the CHANNEL_REQUESTS for the main session channel.
9431 * Each one is handled by its own little asynchronous
9435 /* Potentially enable X11 forwarding. */
9436 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9438 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9439 conf_get_int(ssh->conf, CONF_x11_auth),
9441 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9443 /* Potentially enable agent forwarding. */
9444 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9445 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9447 /* Now allocate a pty for the session. */
9448 if (!conf_get_int(ssh->conf, CONF_nopty))
9449 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9451 /* Send environment variables. */
9452 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9455 * Start a shell or a remote command. We may have to attempt
9456 * this twice if the config data has provided a second choice
9463 if (ssh->fallback_cmd) {
9464 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9465 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9467 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9468 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9472 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9473 ssh2_response_authconn, NULL);
9474 ssh2_pkt_addstring(s->pktout, cmd);
9476 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9477 ssh2_response_authconn, NULL);
9478 ssh2_pkt_addstring(s->pktout, cmd);
9480 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9481 ssh2_response_authconn, NULL);
9483 ssh2_pkt_send(ssh, s->pktout);
9485 crWaitUntilV(pktin);
9487 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9488 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9489 bombout(("Unexpected response to shell/command request:"
9490 " packet type %d", pktin->type));
9494 * We failed to start the command. If this is the
9495 * fallback command, we really are finished; if it's
9496 * not, and if the fallback command exists, try falling
9497 * back to it before complaining.
9499 if (!ssh->fallback_cmd &&
9500 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9501 logevent("Primary command failed; attempting fallback");
9502 ssh->fallback_cmd = TRUE;
9505 bombout(("Server refused to start a shell/command"));
9508 logevent("Started a shell/command");
9513 ssh->editing = ssh->echoing = TRUE;
9516 ssh->state = SSH_STATE_SESSION;
9517 if (ssh->size_needed)
9518 ssh_size(ssh, ssh->term_width, ssh->term_height);
9519 if (ssh->eof_needed)
9520 ssh_special(ssh, TS_EOF);
9526 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9531 s->try_send = FALSE;
9535 * _All_ the connection-layer packets we expect to
9536 * receive are now handled by the dispatch table.
9537 * Anything that reaches here must be bogus.
9540 bombout(("Strange packet received: type %d", pktin->type));
9542 } else if (ssh->mainchan) {
9544 * We have spare data. Add it to the channel buffer.
9546 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9551 struct ssh_channel *c;
9553 * Try to send data on all channels if we can.
9555 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9556 ssh2_try_send_and_unthrottle(ssh, c);
9564 * Handlers for SSH-2 messages that might arrive at any moment.
9566 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9568 /* log reason code in disconnect message */
9572 reason = ssh_pkt_getuint32(pktin);
9573 ssh_pkt_getstring(pktin, &msg, &msglen);
9575 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9576 buf = dupprintf("Received disconnect message (%s)",
9577 ssh2_disconnect_reasons[reason]);
9579 buf = dupprintf("Received disconnect message (unknown"
9580 " type %d)", reason);
9584 buf = dupprintf("Disconnection message text: %.*s",
9587 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9589 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9590 ssh2_disconnect_reasons[reason] : "unknown",
9595 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9597 /* log the debug message */
9601 /* XXX maybe we should actually take notice of the return value */
9602 ssh2_pkt_getbool(pktin);
9603 ssh_pkt_getstring(pktin, &msg, &msglen);
9605 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9608 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9610 do_ssh2_transport(ssh, NULL, 0, pktin);
9614 * Called if we receive a packet that isn't allowed by the protocol.
9615 * This only applies to packets whose meaning PuTTY understands.
9616 * Entirely unknown packets are handled below.
9618 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9620 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9621 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9623 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9627 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9629 struct Packet *pktout;
9630 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9631 ssh2_pkt_adduint32(pktout, pktin->sequence);
9633 * UNIMPLEMENTED messages MUST appear in the same order as the
9634 * messages they respond to. Hence, never queue them.
9636 ssh2_pkt_send_noqueue(ssh, pktout);
9640 * Handle the top-level SSH-2 protocol.
9642 static void ssh2_protocol_setup(Ssh ssh)
9647 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9649 for (i = 0; i < 256; i++)
9650 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9653 * Initially, we only accept transport messages (and a few generic
9654 * ones). do_ssh2_authconn will add more when it starts.
9655 * Messages that are understood but not currently acceptable go to
9656 * ssh2_msg_unexpected.
9658 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9659 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9660 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9661 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9662 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9663 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9664 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9665 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9666 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9667 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9668 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9669 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9670 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9671 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9672 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9673 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9674 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9675 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9676 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9677 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9678 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9679 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9680 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9681 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9682 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9683 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9684 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9685 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9686 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9687 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9688 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9689 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9690 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9693 * These messages have a special handler from the start.
9695 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9696 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9697 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9700 static void ssh2_timer(void *ctx, unsigned long now)
9704 if (ssh->state == SSH_STATE_CLOSED)
9707 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9708 now == ssh->next_rekey) {
9709 do_ssh2_transport(ssh, "timeout", -1, NULL);
9713 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9714 struct Packet *pktin)
9716 unsigned char *in = (unsigned char *)vin;
9717 if (ssh->state == SSH_STATE_CLOSED)
9721 ssh->incoming_data_size += pktin->encrypted_len;
9722 if (!ssh->kex_in_progress &&
9723 ssh->max_data_size != 0 &&
9724 ssh->incoming_data_size > ssh->max_data_size)
9725 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9729 ssh->packet_dispatch[pktin->type](ssh, pktin);
9730 else if (!ssh->protocol_initial_phase_done)
9731 do_ssh2_transport(ssh, in, inlen, pktin);
9733 do_ssh2_authconn(ssh, in, inlen, pktin);
9736 static void ssh_cache_conf_values(Ssh ssh)
9738 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9742 * Called to set up the connection.
9744 * Returns an error message, or NULL on success.
9746 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9747 Conf *conf, char *host, int port, char **realhost,
9748 int nodelay, int keepalive)
9753 ssh = snew(struct ssh_tag);
9754 ssh->conf = conf_copy(conf);
9755 ssh_cache_conf_values(ssh);
9756 ssh->version = 0; /* when not ready yet */
9759 ssh->v1_cipher_ctx = NULL;
9760 ssh->crcda_ctx = NULL;
9761 ssh->cscipher = NULL;
9762 ssh->cs_cipher_ctx = NULL;
9763 ssh->sccipher = NULL;
9764 ssh->sc_cipher_ctx = NULL;
9766 ssh->cs_mac_ctx = NULL;
9768 ssh->sc_mac_ctx = NULL;
9770 ssh->cs_comp_ctx = NULL;
9772 ssh->sc_comp_ctx = NULL;
9774 ssh->kex_ctx = NULL;
9775 ssh->hostkey = NULL;
9776 ssh->hostkey_str = NULL;
9778 ssh->close_expected = FALSE;
9779 ssh->clean_exit = FALSE;
9780 ssh->state = SSH_STATE_PREPACKET;
9781 ssh->size_needed = FALSE;
9782 ssh->eof_needed = FALSE;
9785 ssh->deferred_send_data = NULL;
9786 ssh->deferred_len = 0;
9787 ssh->deferred_size = 0;
9788 ssh->fallback_cmd = 0;
9789 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9790 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9791 ssh->x11disp = NULL;
9792 ssh->v1_compressing = FALSE;
9793 ssh->v2_outgoing_sequence = 0;
9794 ssh->ssh1_rdpkt_crstate = 0;
9795 ssh->ssh2_rdpkt_crstate = 0;
9796 ssh->ssh_gotdata_crstate = 0;
9797 ssh->do_ssh1_connection_crstate = 0;
9798 ssh->do_ssh_init_state = NULL;
9799 ssh->do_ssh1_login_state = NULL;
9800 ssh->do_ssh2_transport_state = NULL;
9801 ssh->do_ssh2_authconn_state = NULL;
9804 ssh->mainchan = NULL;
9805 ssh->throttled_all = 0;
9806 ssh->v1_stdout_throttling = 0;
9808 ssh->queuelen = ssh->queuesize = 0;
9809 ssh->queueing = FALSE;
9810 ssh->qhead = ssh->qtail = NULL;
9811 ssh->deferred_rekey_reason = NULL;
9812 bufchain_init(&ssh->queued_incoming_data);
9813 ssh->frozen = FALSE;
9814 ssh->username = NULL;
9815 ssh->sent_console_eof = FALSE;
9816 ssh->got_pty = FALSE;
9818 *backend_handle = ssh;
9821 if (crypto_startup() == 0)
9822 return "Microsoft high encryption pack not installed!";
9825 ssh->frontend = frontend_handle;
9826 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9827 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9829 ssh->channels = NULL;
9830 ssh->rportfwds = NULL;
9831 ssh->portfwds = NULL;
9836 ssh->conn_throttle_count = 0;
9837 ssh->overall_bufsize = 0;
9838 ssh->fallback_cmd = 0;
9840 ssh->protocol = NULL;
9842 ssh->protocol_initial_phase_done = FALSE;
9846 ssh->incoming_data_size = ssh->outgoing_data_size =
9847 ssh->deferred_data_size = 0L;
9848 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9849 CONF_ssh_rekey_data));
9850 ssh->kex_in_progress = FALSE;
9853 ssh->gsslibs = NULL;
9856 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9865 static void ssh_free(void *handle)
9867 Ssh ssh = (Ssh) handle;
9868 struct ssh_channel *c;
9869 struct ssh_rportfwd *pf;
9871 if (ssh->v1_cipher_ctx)
9872 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9873 if (ssh->cs_cipher_ctx)
9874 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9875 if (ssh->sc_cipher_ctx)
9876 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9877 if (ssh->cs_mac_ctx)
9878 ssh->csmac->free_context(ssh->cs_mac_ctx);
9879 if (ssh->sc_mac_ctx)
9880 ssh->scmac->free_context(ssh->sc_mac_ctx);
9881 if (ssh->cs_comp_ctx) {
9883 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9885 zlib_compress_cleanup(ssh->cs_comp_ctx);
9887 if (ssh->sc_comp_ctx) {
9889 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9891 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9894 dh_cleanup(ssh->kex_ctx);
9895 sfree(ssh->savedhost);
9897 while (ssh->queuelen-- > 0)
9898 ssh_free_packet(ssh->queue[ssh->queuelen]);
9901 while (ssh->qhead) {
9902 struct queued_handler *qh = ssh->qhead;
9903 ssh->qhead = qh->next;
9906 ssh->qhead = ssh->qtail = NULL;
9908 if (ssh->channels) {
9909 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9912 if (c->u.x11.s != NULL)
9913 x11_close(c->u.x11.s);
9916 case CHAN_SOCKDATA_DORMANT:
9917 if (c->u.pfd.s != NULL)
9918 pfd_close(c->u.pfd.s);
9921 if (ssh->version == 2) {
9922 struct outstanding_channel_request *ocr, *nocr;
9923 ocr = c->v.v2.chanreq_head;
9925 ocr->handler(c, NULL, ocr->ctx);
9930 bufchain_clear(&c->v.v2.outbuffer);
9934 freetree234(ssh->channels);
9935 ssh->channels = NULL;
9938 if (ssh->rportfwds) {
9939 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9941 freetree234(ssh->rportfwds);
9942 ssh->rportfwds = NULL;
9944 sfree(ssh->deferred_send_data);
9946 x11_free_display(ssh->x11disp);
9947 sfree(ssh->do_ssh_init_state);
9948 sfree(ssh->do_ssh1_login_state);
9949 sfree(ssh->do_ssh2_transport_state);
9950 sfree(ssh->do_ssh2_authconn_state);
9953 sfree(ssh->fullhostname);
9954 sfree(ssh->hostkey_str);
9955 if (ssh->crcda_ctx) {
9956 crcda_free_context(ssh->crcda_ctx);
9957 ssh->crcda_ctx = NULL;
9960 ssh_do_close(ssh, TRUE);
9961 expire_timer_context(ssh);
9963 pinger_free(ssh->pinger);
9964 bufchain_clear(&ssh->queued_incoming_data);
9965 sfree(ssh->username);
9966 conf_free(ssh->conf);
9969 ssh_gss_cleanup(ssh->gsslibs);
9977 * Reconfigure the SSH backend.
9979 static void ssh_reconfig(void *handle, Conf *conf)
9981 Ssh ssh = (Ssh) handle;
9982 char *rekeying = NULL, rekey_mandatory = FALSE;
9983 unsigned long old_max_data_size;
9986 pinger_reconfig(ssh->pinger, ssh->conf, conf);
9988 ssh_setup_portfwd(ssh, conf);
9990 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9991 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9993 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
9994 unsigned long now = GETTICKCOUNT();
9996 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
9997 rekeying = "timeout shortened";
9999 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10003 old_max_data_size = ssh->max_data_size;
10004 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10005 CONF_ssh_rekey_data));
10006 if (old_max_data_size != ssh->max_data_size &&
10007 ssh->max_data_size != 0) {
10008 if (ssh->outgoing_data_size > ssh->max_data_size ||
10009 ssh->incoming_data_size > ssh->max_data_size)
10010 rekeying = "data limit lowered";
10013 if (conf_get_int(ssh->conf, CONF_compression) !=
10014 conf_get_int(conf, CONF_compression)) {
10015 rekeying = "compression setting changed";
10016 rekey_mandatory = TRUE;
10019 for (i = 0; i < CIPHER_MAX; i++)
10020 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10021 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10022 rekeying = "cipher settings changed";
10023 rekey_mandatory = TRUE;
10025 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10026 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10027 rekeying = "cipher settings changed";
10028 rekey_mandatory = TRUE;
10031 conf_free(ssh->conf);
10032 ssh->conf = conf_copy(conf);
10033 ssh_cache_conf_values(ssh);
10036 if (!ssh->kex_in_progress) {
10037 do_ssh2_transport(ssh, rekeying, -1, NULL);
10038 } else if (rekey_mandatory) {
10039 ssh->deferred_rekey_reason = rekeying;
10045 * Called to send data down the SSH connection.
10047 static int ssh_send(void *handle, char *buf, int len)
10049 Ssh ssh = (Ssh) handle;
10051 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10054 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10056 return ssh_sendbuffer(ssh);
10060 * Called to query the current amount of buffered stdin data.
10062 static int ssh_sendbuffer(void *handle)
10064 Ssh ssh = (Ssh) handle;
10065 int override_value;
10067 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10071 * If the SSH socket itself has backed up, add the total backup
10072 * size on that to any individual buffer on the stdin channel.
10074 override_value = 0;
10075 if (ssh->throttled_all)
10076 override_value = ssh->overall_bufsize;
10078 if (ssh->version == 1) {
10079 return override_value;
10080 } else if (ssh->version == 2) {
10081 if (!ssh->mainchan)
10082 return override_value;
10084 return (override_value +
10085 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10092 * Called to set the size of the window from SSH's POV.
10094 static void ssh_size(void *handle, int width, int height)
10096 Ssh ssh = (Ssh) handle;
10097 struct Packet *pktout;
10099 ssh->term_width = width;
10100 ssh->term_height = height;
10102 switch (ssh->state) {
10103 case SSH_STATE_BEFORE_SIZE:
10104 case SSH_STATE_PREPACKET:
10105 case SSH_STATE_CLOSED:
10106 break; /* do nothing */
10107 case SSH_STATE_INTERMED:
10108 ssh->size_needed = TRUE; /* buffer for later */
10110 case SSH_STATE_SESSION:
10111 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10112 if (ssh->version == 1) {
10113 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10114 PKT_INT, ssh->term_height,
10115 PKT_INT, ssh->term_width,
10116 PKT_INT, 0, PKT_INT, 0, PKT_END);
10117 } else if (ssh->mainchan) {
10118 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10120 ssh2_pkt_adduint32(pktout, ssh->term_width);
10121 ssh2_pkt_adduint32(pktout, ssh->term_height);
10122 ssh2_pkt_adduint32(pktout, 0);
10123 ssh2_pkt_adduint32(pktout, 0);
10124 ssh2_pkt_send(ssh, pktout);
10132 * Return a list of the special codes that make sense in this
10135 static const struct telnet_special *ssh_get_specials(void *handle)
10137 static const struct telnet_special ssh1_ignore_special[] = {
10138 {"IGNORE message", TS_NOP}
10140 static const struct telnet_special ssh2_ignore_special[] = {
10141 {"IGNORE message", TS_NOP},
10143 static const struct telnet_special ssh2_rekey_special[] = {
10144 {"Repeat key exchange", TS_REKEY},
10146 static const struct telnet_special ssh2_session_specials[] = {
10149 /* These are the signal names defined by RFC 4254.
10150 * They include all the ISO C signals, but are a subset of the POSIX
10151 * required signals. */
10152 {"SIGINT (Interrupt)", TS_SIGINT},
10153 {"SIGTERM (Terminate)", TS_SIGTERM},
10154 {"SIGKILL (Kill)", TS_SIGKILL},
10155 {"SIGQUIT (Quit)", TS_SIGQUIT},
10156 {"SIGHUP (Hangup)", TS_SIGHUP},
10157 {"More signals", TS_SUBMENU},
10158 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10159 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10160 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10161 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10162 {NULL, TS_EXITMENU}
10164 static const struct telnet_special specials_end[] = {
10165 {NULL, TS_EXITMENU}
10167 /* XXX review this length for any changes: */
10168 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10169 lenof(ssh2_rekey_special) +
10170 lenof(ssh2_session_specials) +
10171 lenof(specials_end)];
10172 Ssh ssh = (Ssh) handle;
10174 #define ADD_SPECIALS(name) \
10176 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10177 memcpy(&ssh_specials[i], name, sizeof name); \
10178 i += lenof(name); \
10181 if (ssh->version == 1) {
10182 /* Don't bother offering IGNORE if we've decided the remote
10183 * won't cope with it, since we wouldn't bother sending it if
10185 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10186 ADD_SPECIALS(ssh1_ignore_special);
10187 } else if (ssh->version == 2) {
10188 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10189 ADD_SPECIALS(ssh2_ignore_special);
10190 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10191 ADD_SPECIALS(ssh2_rekey_special);
10193 ADD_SPECIALS(ssh2_session_specials);
10194 } /* else we're not ready yet */
10197 ADD_SPECIALS(specials_end);
10198 return ssh_specials;
10202 #undef ADD_SPECIALS
10206 * Send special codes. TS_EOF is useful for `plink', so you
10207 * can send an EOF and collect resulting output (e.g. `plink
10210 static void ssh_special(void *handle, Telnet_Special code)
10212 Ssh ssh = (Ssh) handle;
10213 struct Packet *pktout;
10215 if (code == TS_EOF) {
10216 if (ssh->state != SSH_STATE_SESSION) {
10218 * Buffer the EOF in case we are pre-SESSION, so we can
10219 * send it as soon as we reach SESSION.
10221 if (code == TS_EOF)
10222 ssh->eof_needed = TRUE;
10225 if (ssh->version == 1) {
10226 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10227 } else if (ssh->mainchan) {
10228 sshfwd_write_eof(ssh->mainchan);
10229 ssh->send_ok = 0; /* now stop trying to read from stdin */
10231 logevent("Sent EOF message");
10232 } else if (code == TS_PING || code == TS_NOP) {
10233 if (ssh->state == SSH_STATE_CLOSED
10234 || ssh->state == SSH_STATE_PREPACKET) return;
10235 if (ssh->version == 1) {
10236 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10237 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10239 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10240 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10241 ssh2_pkt_addstring_start(pktout);
10242 ssh2_pkt_send_noqueue(ssh, pktout);
10245 } else if (code == TS_REKEY) {
10246 if (!ssh->kex_in_progress && ssh->version == 2) {
10247 do_ssh2_transport(ssh, "at user request", -1, NULL);
10249 } else if (code == TS_BRK) {
10250 if (ssh->state == SSH_STATE_CLOSED
10251 || ssh->state == SSH_STATE_PREPACKET) return;
10252 if (ssh->version == 1) {
10253 logevent("Unable to send BREAK signal in SSH-1");
10254 } else if (ssh->mainchan) {
10255 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10256 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10257 ssh2_pkt_send(ssh, pktout);
10260 /* Is is a POSIX signal? */
10261 char *signame = NULL;
10262 if (code == TS_SIGABRT) signame = "ABRT";
10263 if (code == TS_SIGALRM) signame = "ALRM";
10264 if (code == TS_SIGFPE) signame = "FPE";
10265 if (code == TS_SIGHUP) signame = "HUP";
10266 if (code == TS_SIGILL) signame = "ILL";
10267 if (code == TS_SIGINT) signame = "INT";
10268 if (code == TS_SIGKILL) signame = "KILL";
10269 if (code == TS_SIGPIPE) signame = "PIPE";
10270 if (code == TS_SIGQUIT) signame = "QUIT";
10271 if (code == TS_SIGSEGV) signame = "SEGV";
10272 if (code == TS_SIGTERM) signame = "TERM";
10273 if (code == TS_SIGUSR1) signame = "USR1";
10274 if (code == TS_SIGUSR2) signame = "USR2";
10275 /* The SSH-2 protocol does in principle support arbitrary named
10276 * signals, including signame@domain, but we don't support those. */
10278 /* It's a signal. */
10279 if (ssh->version == 2 && ssh->mainchan) {
10280 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10281 ssh2_pkt_addstring(pktout, signame);
10282 ssh2_pkt_send(ssh, pktout);
10283 logeventf(ssh, "Sent signal SIG%s", signame);
10286 /* Never heard of it. Do nothing */
10291 void *new_sock_channel(void *handle, Socket s)
10293 Ssh ssh = (Ssh) handle;
10294 struct ssh_channel *c;
10295 c = snew(struct ssh_channel);
10298 ssh2_channel_init(c);
10299 c->halfopen = TRUE;
10300 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10302 add234(ssh->channels, c);
10307 * This is called when stdout/stderr (the entity to which
10308 * from_backend sends data) manages to clear some backlog.
10310 static void ssh_unthrottle(void *handle, int bufsize)
10312 Ssh ssh = (Ssh) handle;
10315 if (ssh->version == 1) {
10316 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10317 ssh->v1_stdout_throttling = 0;
10318 ssh_throttle_conn(ssh, -1);
10321 if (ssh->mainchan) {
10322 ssh2_set_window(ssh->mainchan,
10323 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10324 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10325 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10328 buflimit = ssh->mainchan->v.v2.locmaxwin;
10329 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10330 ssh->mainchan->throttling_conn = 0;
10331 ssh_throttle_conn(ssh, -1);
10337 * Now process any SSH connection data that was stashed in our
10338 * queue while we were frozen.
10340 ssh_process_queued_incoming_data(ssh);
10343 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10345 struct ssh_channel *c = (struct ssh_channel *)channel;
10347 struct Packet *pktout;
10349 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10351 if (ssh->version == 1) {
10352 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10353 PKT_INT, c->localid,
10356 /* PKT_STR, <org:orgport>, */
10359 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10360 ssh2_pkt_addstring(pktout, hostname);
10361 ssh2_pkt_adduint32(pktout, port);
10363 * We make up values for the originator data; partly it's
10364 * too much hassle to keep track, and partly I'm not
10365 * convinced the server should be told details like that
10366 * about my local network configuration.
10367 * The "originator IP address" is syntactically a numeric
10368 * IP address, and some servers (e.g., Tectia) get upset
10369 * if it doesn't match this syntax.
10371 ssh2_pkt_addstring(pktout, "0.0.0.0");
10372 ssh2_pkt_adduint32(pktout, 0);
10373 ssh2_pkt_send(ssh, pktout);
10377 static int ssh_connected(void *handle)
10379 Ssh ssh = (Ssh) handle;
10380 return ssh->s != NULL;
10383 static int ssh_sendok(void *handle)
10385 Ssh ssh = (Ssh) handle;
10386 return ssh->send_ok;
10389 static int ssh_ldisc(void *handle, int option)
10391 Ssh ssh = (Ssh) handle;
10392 if (option == LD_ECHO)
10393 return ssh->echoing;
10394 if (option == LD_EDIT)
10395 return ssh->editing;
10399 static void ssh_provide_ldisc(void *handle, void *ldisc)
10401 Ssh ssh = (Ssh) handle;
10402 ssh->ldisc = ldisc;
10405 static void ssh_provide_logctx(void *handle, void *logctx)
10407 Ssh ssh = (Ssh) handle;
10408 ssh->logctx = logctx;
10411 static int ssh_return_exitcode(void *handle)
10413 Ssh ssh = (Ssh) handle;
10414 if (ssh->s != NULL)
10417 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10421 * cfg_info for SSH is the currently running version of the
10422 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10424 static int ssh_cfg_info(void *handle)
10426 Ssh ssh = (Ssh) handle;
10427 return ssh->version;
10431 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10432 * that fails. This variable is the means by which scp.c can reach
10433 * into the SSH code and find out which one it got.
10435 extern int ssh_fallback_cmd(void *handle)
10437 Ssh ssh = (Ssh) handle;
10438 return ssh->fallback_cmd;
10441 Backend ssh_backend = {
10451 ssh_return_exitcode,
10455 ssh_provide_logctx,