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 {
547 struct X11Connection *xconn;
549 struct ssh_pfd_channel {
550 struct PortForwarding *pf;
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;
616 struct PortListener *local;
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,
1767 return sk_write(ssh->s, (char *)data, len);
1770 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1772 int len, backlog, offset;
1773 len = s_wrpkt_prepare(ssh, pkt, &offset);
1774 backlog = s_write(ssh, pkt->data + offset, len);
1775 if (backlog > SSH_MAX_BACKLOG)
1776 ssh_throttle_all(ssh, 1, backlog);
1777 ssh_free_packet(pkt);
1780 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1783 len = s_wrpkt_prepare(ssh, pkt, &offset);
1784 if (ssh->deferred_len + len > ssh->deferred_size) {
1785 ssh->deferred_size = ssh->deferred_len + len + 128;
1786 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1790 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1791 pkt->data + offset, len);
1792 ssh->deferred_len += len;
1793 ssh_free_packet(pkt);
1797 * Construct a SSH-1 packet with the specified contents.
1798 * (This all-at-once interface used to be the only one, but now SSH-1
1799 * packets can also be constructed incrementally.)
1801 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1807 pkt = ssh1_pkt_init(pkttype);
1809 while ((argtype = va_arg(ap, int)) != PKT_END) {
1810 unsigned char *argp, argchar;
1812 unsigned long argint;
1815 /* Actual fields in the packet */
1817 argint = va_arg(ap, int);
1818 ssh_pkt_adduint32(pkt, argint);
1821 argchar = (unsigned char) va_arg(ap, int);
1822 ssh_pkt_addbyte(pkt, argchar);
1825 argp = va_arg(ap, unsigned char *);
1826 arglen = va_arg(ap, int);
1827 ssh_pkt_adddata(pkt, argp, arglen);
1830 sargp = va_arg(ap, char *);
1831 ssh_pkt_addstring(pkt, sargp);
1834 bn = va_arg(ap, Bignum);
1835 ssh1_pkt_addmp(pkt, bn);
1843 static void send_packet(Ssh ssh, int pkttype, ...)
1847 va_start(ap, pkttype);
1848 pkt = construct_packet(ssh, pkttype, ap);
1853 static void defer_packet(Ssh ssh, int pkttype, ...)
1857 va_start(ap, pkttype);
1858 pkt = construct_packet(ssh, pkttype, ap);
1860 s_wrpkt_defer(ssh, pkt);
1863 static int ssh_versioncmp(char *a, char *b)
1866 unsigned long av, bv;
1868 av = strtoul(a, &ae, 10);
1869 bv = strtoul(b, &be, 10);
1871 return (av < bv ? -1 : +1);
1876 av = strtoul(ae, &ae, 10);
1877 bv = strtoul(be, &be, 10);
1879 return (av < bv ? -1 : +1);
1884 * Utility routines for putting an SSH-protocol `string' and
1885 * `uint32' into a hash state.
1887 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1889 unsigned char lenblk[4];
1890 PUT_32BIT(lenblk, len);
1891 h->bytes(s, lenblk, 4);
1892 h->bytes(s, str, len);
1895 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1897 unsigned char intblk[4];
1898 PUT_32BIT(intblk, i);
1899 h->bytes(s, intblk, 4);
1903 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1905 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1907 if (pkt->maxlen < length) {
1908 unsigned char *body = pkt->body;
1909 int offset = body ? body - pkt->data : 0;
1910 pkt->maxlen = length + 256;
1911 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1912 if (body) pkt->body = pkt->data + offset;
1915 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
1918 ssh_pkt_ensure(pkt, pkt->length);
1919 memcpy(pkt->data + pkt->length - len, data, len);
1921 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1923 ssh_pkt_adddata(pkt, &byte, 1);
1925 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1927 ssh_pkt_adddata(pkt, &value, 1);
1929 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1932 PUT_32BIT(x, value);
1933 ssh_pkt_adddata(pkt, x, 4);
1935 static void ssh_pkt_addstring_start(struct Packet *pkt)
1937 ssh_pkt_adduint32(pkt, 0);
1938 pkt->savedpos = pkt->length;
1940 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
1942 ssh_pkt_adddata(pkt, data, strlen(data));
1943 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1945 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
1948 ssh_pkt_adddata(pkt, data, len);
1949 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1951 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
1953 ssh_pkt_addstring_start(pkt);
1954 ssh_pkt_addstring_str(pkt, data);
1956 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1958 int len = ssh1_bignum_length(b);
1959 unsigned char *data = snewn(len, unsigned char);
1960 (void) ssh1_write_bignum(data, b);
1961 ssh_pkt_adddata(pkt, data, len);
1964 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1967 int i, n = (bignum_bitcount(b) + 7) / 8;
1968 p = snewn(n + 1, unsigned char);
1970 for (i = 1; i <= n; i++)
1971 p[i] = bignum_byte(b, n - i);
1973 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1975 memmove(p, p + i, n + 1 - i);
1979 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1983 p = ssh2_mpint_fmt(b, &len);
1984 ssh_pkt_addstring_start(pkt);
1985 ssh_pkt_addstring_data(pkt, (char *)p, len);
1989 static struct Packet *ssh1_pkt_init(int pkt_type)
1991 struct Packet *pkt = ssh_new_packet();
1992 pkt->length = 4 + 8; /* space for length + max padding */
1993 ssh_pkt_addbyte(pkt, pkt_type);
1994 pkt->body = pkt->data + pkt->length;
1995 pkt->type = pkt_type;
1999 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2000 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2001 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2002 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2003 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2004 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2005 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2006 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2007 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2009 static struct Packet *ssh2_pkt_init(int pkt_type)
2011 struct Packet *pkt = ssh_new_packet();
2012 pkt->length = 5; /* space for packet length + padding length */
2014 pkt->type = pkt_type;
2015 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2016 pkt->body = pkt->data + pkt->length; /* after packet type */
2021 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2022 * put the MAC on it. Final packet, ready to be sent, is stored in
2023 * pkt->data. Total length is returned.
2025 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2027 int cipherblk, maclen, padding, i;
2030 ssh2_log_outgoing_packet(ssh, pkt);
2033 * Compress packet payload.
2036 unsigned char *newpayload;
2039 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2041 &newpayload, &newlen)) {
2043 ssh2_pkt_adddata(pkt, newpayload, newlen);
2049 * Add padding. At least four bytes, and must also bring total
2050 * length (minus MAC) up to a multiple of the block size.
2051 * If pkt->forcepad is set, make sure the packet is at least that size
2054 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2055 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2057 if (pkt->length + padding < pkt->forcepad)
2058 padding = pkt->forcepad - pkt->length;
2060 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2061 assert(padding <= 255);
2062 maclen = ssh->csmac ? ssh->csmac->len : 0;
2063 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2064 pkt->data[4] = padding;
2065 for (i = 0; i < padding; i++)
2066 pkt->data[pkt->length + i] = random_byte();
2067 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2069 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2070 pkt->length + padding,
2071 ssh->v2_outgoing_sequence);
2072 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2075 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2076 pkt->data, pkt->length + padding);
2078 pkt->encrypted_len = pkt->length + padding;
2080 /* Ready-to-send packet starts at pkt->data. We return length. */
2081 return pkt->length + padding + maclen;
2085 * Routines called from the main SSH code to send packets. There
2086 * are quite a few of these, because we have two separate
2087 * mechanisms for delaying the sending of packets:
2089 * - In order to send an IGNORE message and a password message in
2090 * a single fixed-length blob, we require the ability to
2091 * concatenate the encrypted forms of those two packets _into_ a
2092 * single blob and then pass it to our <network.h> transport
2093 * layer in one go. Hence, there's a deferment mechanism which
2094 * works after packet encryption.
2096 * - In order to avoid sending any connection-layer messages
2097 * during repeat key exchange, we have to queue up any such
2098 * outgoing messages _before_ they are encrypted (and in
2099 * particular before they're allocated sequence numbers), and
2100 * then send them once we've finished.
2102 * I call these mechanisms `defer' and `queue' respectively, so as
2103 * to distinguish them reasonably easily.
2105 * The functions send_noqueue() and defer_noqueue() free the packet
2106 * structure they are passed. Every outgoing packet goes through
2107 * precisely one of these functions in its life; packets passed to
2108 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2109 * these or get queued, and then when the queue is later emptied
2110 * the packets are all passed to defer_noqueue().
2112 * When using a CBC-mode cipher, it's necessary to ensure that an
2113 * attacker can't provide data to be encrypted using an IV that they
2114 * know. We ensure this by prefixing each packet that might contain
2115 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2116 * mechanism, so in this case send_noqueue() ends up redirecting to
2117 * defer_noqueue(). If you don't like this inefficiency, don't use
2121 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2122 static void ssh_pkt_defersend(Ssh);
2125 * Send an SSH-2 packet immediately, without queuing or deferring.
2127 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2131 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2132 /* We need to send two packets, so use the deferral mechanism. */
2133 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2134 ssh_pkt_defersend(ssh);
2137 len = ssh2_pkt_construct(ssh, pkt);
2138 backlog = s_write(ssh, pkt->data, len);
2139 if (backlog > SSH_MAX_BACKLOG)
2140 ssh_throttle_all(ssh, 1, backlog);
2142 ssh->outgoing_data_size += pkt->encrypted_len;
2143 if (!ssh->kex_in_progress &&
2144 ssh->max_data_size != 0 &&
2145 ssh->outgoing_data_size > ssh->max_data_size)
2146 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2148 ssh_free_packet(pkt);
2152 * Defer an SSH-2 packet.
2154 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2157 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2158 ssh->deferred_len == 0 && !noignore &&
2159 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2161 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2162 * get encrypted with a known IV.
2164 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2165 ssh2_pkt_addstring_start(ipkt);
2166 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2168 len = ssh2_pkt_construct(ssh, pkt);
2169 if (ssh->deferred_len + len > ssh->deferred_size) {
2170 ssh->deferred_size = ssh->deferred_len + len + 128;
2171 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2175 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2176 ssh->deferred_len += len;
2177 ssh->deferred_data_size += pkt->encrypted_len;
2178 ssh_free_packet(pkt);
2182 * Queue an SSH-2 packet.
2184 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2186 assert(ssh->queueing);
2188 if (ssh->queuelen >= ssh->queuesize) {
2189 ssh->queuesize = ssh->queuelen + 32;
2190 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2193 ssh->queue[ssh->queuelen++] = pkt;
2197 * Either queue or send a packet, depending on whether queueing is
2200 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2203 ssh2_pkt_queue(ssh, pkt);
2205 ssh2_pkt_send_noqueue(ssh, pkt);
2209 * Either queue or defer a packet, depending on whether queueing is
2212 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2215 ssh2_pkt_queue(ssh, pkt);
2217 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2221 * Send the whole deferred data block constructed by
2222 * ssh2_pkt_defer() or SSH-1's defer_packet().
2224 * The expected use of the defer mechanism is that you call
2225 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2226 * not currently queueing, this simply sets up deferred_send_data
2227 * and then sends it. If we _are_ currently queueing, the calls to
2228 * ssh2_pkt_defer() put the deferred packets on to the queue
2229 * instead, and therefore ssh_pkt_defersend() has no deferred data
2230 * to send. Hence, there's no need to make it conditional on
2233 static void ssh_pkt_defersend(Ssh ssh)
2236 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2237 ssh->deferred_len = ssh->deferred_size = 0;
2238 sfree(ssh->deferred_send_data);
2239 ssh->deferred_send_data = NULL;
2240 if (backlog > SSH_MAX_BACKLOG)
2241 ssh_throttle_all(ssh, 1, backlog);
2243 ssh->outgoing_data_size += ssh->deferred_data_size;
2244 if (!ssh->kex_in_progress &&
2245 ssh->max_data_size != 0 &&
2246 ssh->outgoing_data_size > ssh->max_data_size)
2247 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2248 ssh->deferred_data_size = 0;
2252 * Send a packet whose length needs to be disguised (typically
2253 * passwords or keyboard-interactive responses).
2255 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2261 * The simplest way to do this is to adjust the
2262 * variable-length padding field in the outgoing packet.
2264 * Currently compiled out, because some Cisco SSH servers
2265 * don't like excessively padded packets (bah, why's it
2268 pkt->forcepad = padsize;
2269 ssh2_pkt_send(ssh, pkt);
2274 * If we can't do that, however, an alternative approach is
2275 * to use the pkt_defer mechanism to bundle the packet
2276 * tightly together with an SSH_MSG_IGNORE such that their
2277 * combined length is a constant. So first we construct the
2278 * final form of this packet and defer its sending.
2280 ssh2_pkt_defer(ssh, pkt);
2283 * Now construct an SSH_MSG_IGNORE which includes a string
2284 * that's an exact multiple of the cipher block size. (If
2285 * the cipher is NULL so that the block size is
2286 * unavailable, we don't do this trick at all, because we
2287 * gain nothing by it.)
2289 if (ssh->cscipher &&
2290 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2293 stringlen = (256 - ssh->deferred_len);
2294 stringlen += ssh->cscipher->blksize - 1;
2295 stringlen -= (stringlen % ssh->cscipher->blksize);
2298 * Temporarily disable actual compression, so we
2299 * can guarantee to get this string exactly the
2300 * length we want it. The compression-disabling
2301 * routine should return an integer indicating how
2302 * many bytes we should adjust our string length
2306 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2308 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2309 ssh2_pkt_addstring_start(pkt);
2310 for (i = 0; i < stringlen; i++) {
2311 char c = (char) random_byte();
2312 ssh2_pkt_addstring_data(pkt, &c, 1);
2314 ssh2_pkt_defer(ssh, pkt);
2316 ssh_pkt_defersend(ssh);
2321 * Send all queued SSH-2 packets. We send them by means of
2322 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2323 * packets that needed to be lumped together.
2325 static void ssh2_pkt_queuesend(Ssh ssh)
2329 assert(!ssh->queueing);
2331 for (i = 0; i < ssh->queuelen; i++)
2332 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2335 ssh_pkt_defersend(ssh);
2339 void bndebug(char *string, Bignum b)
2343 p = ssh2_mpint_fmt(b, &len);
2344 debug(("%s", string));
2345 for (i = 0; i < len; i++)
2346 debug((" %02x", p[i]));
2352 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2356 p = ssh2_mpint_fmt(b, &len);
2357 hash_string(h, s, p, len);
2362 * Packet decode functions for both SSH-1 and SSH-2.
2364 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2366 unsigned long value;
2367 if (pkt->length - pkt->savedpos < 4)
2368 return 0; /* arrgh, no way to decline (FIXME?) */
2369 value = GET_32BIT(pkt->body + pkt->savedpos);
2373 static int ssh2_pkt_getbool(struct Packet *pkt)
2375 unsigned long value;
2376 if (pkt->length - pkt->savedpos < 1)
2377 return 0; /* arrgh, no way to decline (FIXME?) */
2378 value = pkt->body[pkt->savedpos] != 0;
2382 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2387 if (pkt->length - pkt->savedpos < 4)
2389 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2394 if (pkt->length - pkt->savedpos < *length)
2396 *p = (char *)(pkt->body + pkt->savedpos);
2397 pkt->savedpos += *length;
2399 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2401 if (pkt->length - pkt->savedpos < length)
2403 pkt->savedpos += length;
2404 return pkt->body + (pkt->savedpos - length);
2406 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2407 unsigned char **keystr)
2411 j = makekey(pkt->body + pkt->savedpos,
2412 pkt->length - pkt->savedpos,
2419 assert(pkt->savedpos < pkt->length);
2423 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2428 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2429 pkt->length - pkt->savedpos, &b);
2437 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2443 ssh_pkt_getstring(pkt, &p, &length);
2448 b = bignum_from_bytes((unsigned char *)p, length);
2453 * Helper function to add an SSH-2 signature blob to a packet.
2454 * Expects to be shown the public key blob as well as the signature
2455 * blob. Normally works just like ssh2_pkt_addstring, but will
2456 * fiddle with the signature packet if necessary for
2457 * BUG_SSH2_RSA_PADDING.
2459 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2460 void *pkblob_v, int pkblob_len,
2461 void *sigblob_v, int sigblob_len)
2463 unsigned char *pkblob = (unsigned char *)pkblob_v;
2464 unsigned char *sigblob = (unsigned char *)sigblob_v;
2466 /* dmemdump(pkblob, pkblob_len); */
2467 /* dmemdump(sigblob, sigblob_len); */
2470 * See if this is in fact an ssh-rsa signature and a buggy
2471 * server; otherwise we can just do this the easy way.
2473 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2474 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2475 int pos, len, siglen;
2478 * Find the byte length of the modulus.
2481 pos = 4+7; /* skip over "ssh-rsa" */
2482 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2483 if (len < 0 || len > pkblob_len - pos - 4)
2485 pos += 4 + len; /* skip over exponent */
2486 if (pkblob_len - pos < 4)
2488 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2489 if (len < 0 || len > pkblob_len - pos - 4)
2491 pos += 4; /* find modulus itself */
2492 while (len > 0 && pkblob[pos] == 0)
2494 /* debug(("modulus length is %d\n", len)); */
2497 * Now find the signature integer.
2499 pos = 4+7; /* skip over "ssh-rsa" */
2500 if (sigblob_len < pos+4)
2502 siglen = toint(GET_32BIT(sigblob+pos));
2503 if (siglen != sigblob_len - pos - 4)
2505 /* debug(("signature length is %d\n", siglen)); */
2507 if (len != siglen) {
2508 unsigned char newlen[4];
2509 ssh2_pkt_addstring_start(pkt);
2510 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2511 /* dmemdump(sigblob, pos); */
2512 pos += 4; /* point to start of actual sig */
2513 PUT_32BIT(newlen, len);
2514 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2515 /* dmemdump(newlen, 4); */
2517 while (len-- > siglen) {
2518 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2519 /* dmemdump(newlen, 1); */
2521 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2522 /* dmemdump(sigblob+pos, siglen); */
2526 /* Otherwise fall through and do it the easy way. We also come
2527 * here as a fallback if we discover above that the key blob
2528 * is misformatted in some way. */
2532 ssh2_pkt_addstring_start(pkt);
2533 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2537 * Examine the remote side's version string and compare it against
2538 * a list of known buggy implementations.
2540 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2542 char *imp; /* pointer to implementation part */
2544 imp += strcspn(imp, "-");
2546 imp += strcspn(imp, "-");
2549 ssh->remote_bugs = 0;
2552 * General notes on server version strings:
2553 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2554 * here -- in particular, we've heard of one that's perfectly happy
2555 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2556 * so we can't distinguish them.
2558 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2559 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2560 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2561 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2562 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2563 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2565 * These versions don't support SSH1_MSG_IGNORE, so we have
2566 * to use a different defence against password length
2569 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2570 logevent("We believe remote version has SSH-1 ignore bug");
2573 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2574 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2575 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2577 * These versions need a plain password sent; they can't
2578 * handle having a null and a random length of data after
2581 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2582 logevent("We believe remote version needs a plain SSH-1 password");
2585 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2586 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2587 (!strcmp(imp, "Cisco-1.25")))) {
2589 * These versions apparently have no clue whatever about
2590 * RSA authentication and will panic and die if they see
2591 * an AUTH_RSA message.
2593 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2594 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2597 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2598 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2599 !wc_match("* VShell", imp) &&
2600 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2601 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2602 wc_match("2.1 *", imp)))) {
2604 * These versions have the HMAC bug.
2606 ssh->remote_bugs |= BUG_SSH2_HMAC;
2607 logevent("We believe remote version has SSH-2 HMAC bug");
2610 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2611 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2612 !wc_match("* VShell", imp) &&
2613 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2615 * These versions have the key-derivation bug (failing to
2616 * include the literal shared secret in the hashes that
2617 * generate the keys).
2619 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2620 logevent("We believe remote version has SSH-2 key-derivation bug");
2623 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2624 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2625 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2626 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2628 * These versions have the SSH-2 RSA padding bug.
2630 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2631 logevent("We believe remote version has SSH-2 RSA padding bug");
2634 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2635 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2636 wc_match("OpenSSH_2.[0-2]*", imp))) {
2638 * These versions have the SSH-2 session-ID bug in
2639 * public-key authentication.
2641 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2642 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2645 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2646 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2647 (wc_match("DigiSSH_2.0", imp) ||
2648 wc_match("OpenSSH_2.[0-4]*", imp) ||
2649 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2650 wc_match("Sun_SSH_1.0", imp) ||
2651 wc_match("Sun_SSH_1.0.1", imp) ||
2652 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2653 wc_match("WeOnlyDo-*", imp)))) {
2655 * These versions have the SSH-2 rekey bug.
2657 ssh->remote_bugs |= BUG_SSH2_REKEY;
2658 logevent("We believe remote version has SSH-2 rekey bug");
2661 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2662 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2663 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2664 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2666 * This version ignores our makpkt and needs to be throttled.
2668 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2669 logevent("We believe remote version ignores SSH-2 maximum packet size");
2672 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2674 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2675 * none detected automatically.
2677 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2678 logevent("We believe remote version has SSH-2 ignore bug");
2681 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2683 * Servers that don't support our winadj request for one
2684 * reason or another. Currently, none detected automatically.
2686 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2687 logevent("We believe remote version has winadj bug");
2692 * The `software version' part of an SSH version string is required
2693 * to contain no spaces or minus signs.
2695 static void ssh_fix_verstring(char *str)
2697 /* Eat "SSH-<protoversion>-". */
2698 assert(*str == 'S'); str++;
2699 assert(*str == 'S'); str++;
2700 assert(*str == 'H'); str++;
2701 assert(*str == '-'); str++;
2702 while (*str && *str != '-') str++;
2703 assert(*str == '-'); str++;
2705 /* Convert minus signs and spaces in the remaining string into
2708 if (*str == '-' || *str == ' ')
2715 * Send an appropriate SSH version string.
2717 static void ssh_send_verstring(Ssh ssh, char *svers)
2721 if (ssh->version == 2) {
2723 * Construct a v2 version string.
2725 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2728 * Construct a v1 version string.
2730 verstring = dupprintf("SSH-%s-%s\012",
2731 (ssh_versioncmp(svers, "1.5") <= 0 ?
2736 ssh_fix_verstring(verstring);
2738 if (ssh->version == 2) {
2741 * Record our version string.
2743 len = strcspn(verstring, "\015\012");
2744 ssh->v_c = snewn(len + 1, char);
2745 memcpy(ssh->v_c, verstring, len);
2749 logeventf(ssh, "We claim version: %.*s",
2750 strcspn(verstring, "\015\012"), verstring);
2751 s_write(ssh, verstring, strlen(verstring));
2755 static int do_ssh_init(Ssh ssh, unsigned char c)
2757 struct do_ssh_init_state {
2766 crState(do_ssh_init_state);
2770 /* Search for a line beginning with the string "SSH-" in the input. */
2772 if (c != 'S') goto no;
2774 if (c != 'S') goto no;
2776 if (c != 'H') goto no;
2778 if (c != '-') goto no;
2787 s->vstring = snewn(s->vstrsize, char);
2788 strcpy(s->vstring, "SSH-");
2792 crReturn(1); /* get another char */
2793 if (s->vslen >= s->vstrsize - 1) {
2795 s->vstring = sresize(s->vstring, s->vstrsize, char);
2797 s->vstring[s->vslen++] = c;
2800 s->version[s->i] = '\0';
2802 } else if (s->i < sizeof(s->version) - 1)
2803 s->version[s->i++] = c;
2804 } else if (c == '\012')
2808 ssh->agentfwd_enabled = FALSE;
2809 ssh->rdpkt2_state.incoming_sequence = 0;
2811 s->vstring[s->vslen] = 0;
2812 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2813 logeventf(ssh, "Server version: %s", s->vstring);
2814 ssh_detect_bugs(ssh, s->vstring);
2817 * Decide which SSH protocol version to support.
2820 /* Anything strictly below "2.0" means protocol 1 is supported. */
2821 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2822 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2823 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2825 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2826 bombout(("SSH protocol version 1 required by user but not provided by server"));
2829 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2830 bombout(("SSH protocol version 2 required by user but not provided by server"));
2834 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2839 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2841 /* Send the version string, if we haven't already */
2842 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2843 ssh_send_verstring(ssh, s->version);
2845 if (ssh->version == 2) {
2848 * Record their version string.
2850 len = strcspn(s->vstring, "\015\012");
2851 ssh->v_s = snewn(len + 1, char);
2852 memcpy(ssh->v_s, s->vstring, len);
2856 * Initialise SSH-2 protocol.
2858 ssh->protocol = ssh2_protocol;
2859 ssh2_protocol_setup(ssh);
2860 ssh->s_rdpkt = ssh2_rdpkt;
2863 * Initialise SSH-1 protocol.
2865 ssh->protocol = ssh1_protocol;
2866 ssh1_protocol_setup(ssh);
2867 ssh->s_rdpkt = ssh1_rdpkt;
2869 if (ssh->version == 2)
2870 do_ssh2_transport(ssh, NULL, -1, NULL);
2872 update_specials_menu(ssh->frontend);
2873 ssh->state = SSH_STATE_BEFORE_SIZE;
2874 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2881 static void ssh_process_incoming_data(Ssh ssh,
2882 unsigned char **data, int *datalen)
2884 struct Packet *pktin;
2886 pktin = ssh->s_rdpkt(ssh, data, datalen);
2888 ssh->protocol(ssh, NULL, 0, pktin);
2889 ssh_free_packet(pktin);
2893 static void ssh_queue_incoming_data(Ssh ssh,
2894 unsigned char **data, int *datalen)
2896 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2901 static void ssh_process_queued_incoming_data(Ssh ssh)
2904 unsigned char *data;
2907 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2908 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2912 while (!ssh->frozen && len > 0)
2913 ssh_process_incoming_data(ssh, &data, &len);
2916 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2920 static void ssh_set_frozen(Ssh ssh, int frozen)
2923 sk_set_frozen(ssh->s, frozen);
2924 ssh->frozen = frozen;
2927 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2929 /* Log raw data, if we're in that mode. */
2931 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2934 crBegin(ssh->ssh_gotdata_crstate);
2937 * To begin with, feed the characters one by one to the
2938 * protocol initialisation / selection function do_ssh_init().
2939 * When that returns 0, we're done with the initial greeting
2940 * exchange and can move on to packet discipline.
2943 int ret; /* need not be kept across crReturn */
2945 crReturnV; /* more data please */
2946 ret = do_ssh_init(ssh, *data);
2954 * We emerge from that loop when the initial negotiation is
2955 * over and we have selected an s_rdpkt function. Now pass
2956 * everything to s_rdpkt, and then pass the resulting packets
2957 * to the proper protocol handler.
2961 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2963 ssh_queue_incoming_data(ssh, &data, &datalen);
2964 /* This uses up all data and cannot cause anything interesting
2965 * to happen; indeed, for anything to happen at all, we must
2966 * return, so break out. */
2968 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2969 /* This uses up some or all data, and may freeze the
2971 ssh_process_queued_incoming_data(ssh);
2973 /* This uses up some or all data, and may freeze the
2975 ssh_process_incoming_data(ssh, &data, &datalen);
2977 /* FIXME this is probably EBW. */
2978 if (ssh->state == SSH_STATE_CLOSED)
2981 /* We're out of data. Go and get some more. */
2987 static int ssh_do_close(Ssh ssh, int notify_exit)
2990 struct ssh_channel *c;
2992 ssh->state = SSH_STATE_CLOSED;
2993 expire_timer_context(ssh);
2998 notify_remote_exit(ssh->frontend);
3003 * Now we must shut down any port- and X-forwarded channels going
3004 * through this connection.
3006 if (ssh->channels) {
3007 while (NULL != (c = index234(ssh->channels, 0))) {
3010 x11_close(c->u.x11.xconn);
3013 case CHAN_SOCKDATA_DORMANT:
3014 pfd_close(c->u.pfd.pf);
3017 del234(ssh->channels, c); /* moving next one to index 0 */
3018 if (ssh->version == 2)
3019 bufchain_clear(&c->v.v2.outbuffer);
3024 * Go through port-forwardings, and close any associated
3025 * listening sockets.
3027 if (ssh->portfwds) {
3028 struct ssh_portfwd *pf;
3029 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3030 /* Dispose of any listening socket. */
3032 pfl_terminate(pf->local);
3033 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3036 freetree234(ssh->portfwds);
3037 ssh->portfwds = NULL;
3043 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
3044 const char *error_msg, int error_code)
3046 Ssh ssh = (Ssh) plug;
3047 char addrbuf[256], *msg;
3049 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3052 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3054 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3060 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3063 Ssh ssh = (Ssh) plug;
3064 int need_notify = ssh_do_close(ssh, FALSE);
3067 if (!ssh->close_expected)
3068 error_msg = "Server unexpectedly closed network connection";
3070 error_msg = "Server closed network connection";
3073 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3077 notify_remote_exit(ssh->frontend);
3080 logevent(error_msg);
3081 if (!ssh->close_expected || !ssh->clean_exit)
3082 connection_fatal(ssh->frontend, "%s", error_msg);
3086 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3088 Ssh ssh = (Ssh) plug;
3089 ssh_gotdata(ssh, (unsigned char *)data, len);
3090 if (ssh->state == SSH_STATE_CLOSED) {
3091 ssh_do_close(ssh, TRUE);
3097 static void ssh_sent(Plug plug, int bufsize)
3099 Ssh ssh = (Ssh) plug;
3101 * If the send backlog on the SSH socket itself clears, we
3102 * should unthrottle the whole world if it was throttled.
3104 if (bufsize < SSH_MAX_BACKLOG)
3105 ssh_throttle_all(ssh, 0, bufsize);
3109 * Connect to specified host and port.
3110 * Returns an error message, or NULL on success.
3111 * Also places the canonical host name into `realhost'. It must be
3112 * freed by the caller.
3114 static const char *connect_to_host(Ssh ssh, char *host, int port,
3115 char **realhost, int nodelay, int keepalive)
3117 static const struct plug_function_table fn_table = {
3128 int addressfamily, sshprot;
3130 loghost = conf_get_str(ssh->conf, CONF_loghost);
3134 ssh->savedhost = dupstr(loghost);
3135 ssh->savedport = 22; /* default ssh port */
3138 * A colon suffix on savedhost also lets us affect
3141 * (FIXME: do something about IPv6 address literals here.)
3143 colon = strrchr(ssh->savedhost, ':');
3147 ssh->savedport = atoi(colon);
3150 ssh->savedhost = dupstr(host);
3152 port = 22; /* default ssh port */
3153 ssh->savedport = port;
3159 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3160 logeventf(ssh, "Looking up host \"%s\"%s", host,
3161 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3162 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3163 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3164 if ((err = sk_addr_error(addr)) != NULL) {
3168 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3173 ssh->fn = &fn_table;
3174 ssh->s = new_connection(addr, *realhost, port,
3175 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
3176 if ((err = sk_socket_error(ssh->s)) != NULL) {
3178 notify_remote_exit(ssh->frontend);
3183 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3184 * send the version string too.
3186 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3191 ssh_send_verstring(ssh, NULL);
3195 * loghost, if configured, overrides realhost.
3199 *realhost = dupstr(loghost);
3206 * Throttle or unthrottle the SSH connection.
3208 static void ssh_throttle_conn(Ssh ssh, int adjust)
3210 int old_count = ssh->conn_throttle_count;
3211 ssh->conn_throttle_count += adjust;
3212 assert(ssh->conn_throttle_count >= 0);
3213 if (ssh->conn_throttle_count && !old_count) {
3214 ssh_set_frozen(ssh, 1);
3215 } else if (!ssh->conn_throttle_count && old_count) {
3216 ssh_set_frozen(ssh, 0);
3221 * Throttle or unthrottle _all_ local data streams (for when sends
3222 * on the SSH connection itself back up).
3224 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3227 struct ssh_channel *c;
3229 if (enable == ssh->throttled_all)
3231 ssh->throttled_all = enable;
3232 ssh->overall_bufsize = bufsize;
3235 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3237 case CHAN_MAINSESSION:
3239 * This is treated separately, outside the switch.
3243 x11_override_throttle(c->u.x11.xconn, enable);
3246 /* Agent channels require no buffer management. */
3249 pfd_override_throttle(c->u.pfd.pf, enable);
3255 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3257 Ssh ssh = (Ssh) sshv;
3259 ssh->agent_response = reply;
3260 ssh->agent_response_len = replylen;
3262 if (ssh->version == 1)
3263 do_ssh1_login(ssh, NULL, -1, NULL);
3265 do_ssh2_authconn(ssh, NULL, -1, NULL);
3268 static void ssh_dialog_callback(void *sshv, int ret)
3270 Ssh ssh = (Ssh) sshv;
3272 ssh->user_response = ret;
3274 if (ssh->version == 1)
3275 do_ssh1_login(ssh, NULL, -1, NULL);
3277 do_ssh2_transport(ssh, NULL, -1, NULL);
3280 * This may have unfrozen the SSH connection, so do a
3283 ssh_process_queued_incoming_data(ssh);
3286 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3288 struct ssh_channel *c = (struct ssh_channel *)cv;
3290 void *sentreply = reply;
3292 c->u.a.outstanding_requests--;
3294 /* Fake SSH_AGENT_FAILURE. */
3295 sentreply = "\0\0\0\1\5";
3298 if (ssh->version == 2) {
3299 ssh2_add_channel_data(c, sentreply, replylen);
3302 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3303 PKT_INT, c->remoteid,
3305 PKT_DATA, sentreply, replylen,
3311 * If we've already seen an incoming EOF but haven't sent an
3312 * outgoing one, this may be the moment to send it.
3314 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3315 sshfwd_write_eof(c);
3319 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3320 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3321 * => log `wire_reason'.
3323 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3324 int code, int clean_exit)
3328 client_reason = wire_reason;
3330 error = dupprintf("Disconnected: %s", client_reason);
3332 error = dupstr("Disconnected");
3334 if (ssh->version == 1) {
3335 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3337 } else if (ssh->version == 2) {
3338 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3339 ssh2_pkt_adduint32(pktout, code);
3340 ssh2_pkt_addstring(pktout, wire_reason);
3341 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3342 ssh2_pkt_send_noqueue(ssh, pktout);
3345 ssh->close_expected = TRUE;
3346 ssh->clean_exit = clean_exit;
3347 ssh_closing((Plug)ssh, error, 0, 0);
3352 * Handle the key exchange and user authentication phases.
3354 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3355 struct Packet *pktin)
3358 unsigned char cookie[8], *ptr;
3359 struct MD5Context md5c;
3360 struct do_ssh1_login_state {
3363 unsigned char *rsabuf, *keystr1, *keystr2;
3364 unsigned long supported_ciphers_mask, supported_auths_mask;
3365 int tried_publickey, tried_agent;
3366 int tis_auth_refused, ccard_auth_refused;
3367 unsigned char session_id[16];
3369 void *publickey_blob;
3370 int publickey_bloblen;
3371 char *publickey_comment;
3372 int publickey_encrypted;
3373 prompts_t *cur_prompt;
3376 unsigned char request[5], *response, *p;
3386 struct RSAKey servkey, hostkey;
3388 crState(do_ssh1_login_state);
3395 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3396 bombout(("Public key packet not received"));
3400 logevent("Received public keys");
3402 ptr = ssh_pkt_getdata(pktin, 8);
3404 bombout(("SSH-1 public key packet stopped before random cookie"));
3407 memcpy(cookie, ptr, 8);
3409 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3410 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3411 bombout(("Failed to read SSH-1 public keys from public key packet"));
3416 * Log the host key fingerprint.
3420 logevent("Host key fingerprint is:");
3421 strcpy(logmsg, " ");
3422 s->hostkey.comment = NULL;
3423 rsa_fingerprint(logmsg + strlen(logmsg),
3424 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3428 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3429 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3430 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3431 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3432 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3434 ssh->v1_local_protoflags =
3435 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3436 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3439 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3440 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3441 MD5Update(&md5c, cookie, 8);
3442 MD5Final(s->session_id, &md5c);
3444 for (i = 0; i < 32; i++)
3445 ssh->session_key[i] = random_byte();
3448 * Verify that the `bits' and `bytes' parameters match.
3450 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3451 s->servkey.bits > s->servkey.bytes * 8) {
3452 bombout(("SSH-1 public keys were badly formatted"));
3456 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3457 s->hostkey.bytes : s->servkey.bytes);
3459 s->rsabuf = snewn(s->len, unsigned char);
3462 * Verify the host key.
3466 * First format the key into a string.
3468 int len = rsastr_len(&s->hostkey);
3469 char fingerprint[100];
3470 char *keystr = snewn(len, char);
3471 rsastr_fmt(keystr, &s->hostkey);
3472 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3474 ssh_set_frozen(ssh, 1);
3475 s->dlgret = verify_ssh_host_key(ssh->frontend,
3476 ssh->savedhost, ssh->savedport,
3477 "rsa", keystr, fingerprint,
3478 ssh_dialog_callback, ssh);
3480 if (s->dlgret < 0) {
3484 bombout(("Unexpected data from server while waiting"
3485 " for user host key response"));
3488 } while (pktin || inlen > 0);
3489 s->dlgret = ssh->user_response;
3491 ssh_set_frozen(ssh, 0);
3493 if (s->dlgret == 0) {
3494 ssh_disconnect(ssh, "User aborted at host key verification",
3500 for (i = 0; i < 32; i++) {
3501 s->rsabuf[i] = ssh->session_key[i];
3503 s->rsabuf[i] ^= s->session_id[i];
3506 if (s->hostkey.bytes > s->servkey.bytes) {
3507 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3509 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3511 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3513 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3516 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3520 logevent("Encrypted session key");
3523 int cipher_chosen = 0, warn = 0;
3524 char *cipher_string = NULL;
3526 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3527 int next_cipher = conf_get_int_int(ssh->conf,
3528 CONF_ssh_cipherlist, i);
3529 if (next_cipher == CIPHER_WARN) {
3530 /* If/when we choose a cipher, warn about it */
3532 } else if (next_cipher == CIPHER_AES) {
3533 /* XXX Probably don't need to mention this. */
3534 logevent("AES not supported in SSH-1, skipping");
3536 switch (next_cipher) {
3537 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3538 cipher_string = "3DES"; break;
3539 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3540 cipher_string = "Blowfish"; break;
3541 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3542 cipher_string = "single-DES"; break;
3544 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3548 if (!cipher_chosen) {
3549 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3550 bombout(("Server violates SSH-1 protocol by not "
3551 "supporting 3DES encryption"));
3553 /* shouldn't happen */
3554 bombout(("No supported ciphers found"));
3558 /* Warn about chosen cipher if necessary. */
3560 ssh_set_frozen(ssh, 1);
3561 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3562 ssh_dialog_callback, ssh);
3563 if (s->dlgret < 0) {
3567 bombout(("Unexpected data from server while waiting"
3568 " for user response"));
3571 } while (pktin || inlen > 0);
3572 s->dlgret = ssh->user_response;
3574 ssh_set_frozen(ssh, 0);
3575 if (s->dlgret == 0) {
3576 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3583 switch (s->cipher_type) {
3584 case SSH_CIPHER_3DES:
3585 logevent("Using 3DES encryption");
3587 case SSH_CIPHER_DES:
3588 logevent("Using single-DES encryption");
3590 case SSH_CIPHER_BLOWFISH:
3591 logevent("Using Blowfish encryption");
3595 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3596 PKT_CHAR, s->cipher_type,
3597 PKT_DATA, cookie, 8,
3598 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3599 PKT_DATA, s->rsabuf, s->len,
3600 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3602 logevent("Trying to enable encryption...");
3606 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3607 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3609 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3610 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3611 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3613 ssh->crcda_ctx = crcda_make_context();
3614 logevent("Installing CRC compensation attack detector");
3616 if (s->servkey.modulus) {
3617 sfree(s->servkey.modulus);
3618 s->servkey.modulus = NULL;
3620 if (s->servkey.exponent) {
3621 sfree(s->servkey.exponent);
3622 s->servkey.exponent = NULL;
3624 if (s->hostkey.modulus) {
3625 sfree(s->hostkey.modulus);
3626 s->hostkey.modulus = NULL;
3628 if (s->hostkey.exponent) {
3629 sfree(s->hostkey.exponent);
3630 s->hostkey.exponent = NULL;
3634 if (pktin->type != SSH1_SMSG_SUCCESS) {
3635 bombout(("Encryption not successfully enabled"));
3639 logevent("Successfully started encryption");
3641 fflush(stdout); /* FIXME eh? */
3643 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3644 int ret; /* need not be kept over crReturn */
3645 s->cur_prompt = new_prompts(ssh->frontend);
3646 s->cur_prompt->to_server = TRUE;
3647 s->cur_prompt->name = dupstr("SSH login name");
3648 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3649 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3652 crWaitUntil(!pktin);
3653 ret = get_userpass_input(s->cur_prompt, in, inlen);
3658 * Failed to get a username. Terminate.
3660 free_prompts(s->cur_prompt);
3661 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3664 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3665 free_prompts(s->cur_prompt);
3668 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3670 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3672 if (flags & FLAG_INTERACTIVE &&
3673 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3674 c_write_str(ssh, userlog);
3675 c_write_str(ssh, "\r\n");
3683 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3684 /* We must not attempt PK auth. Pretend we've already tried it. */
3685 s->tried_publickey = s->tried_agent = 1;
3687 s->tried_publickey = s->tried_agent = 0;
3689 s->tis_auth_refused = s->ccard_auth_refused = 0;
3691 * Load the public half of any configured keyfile for later use.
3693 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3694 if (!filename_is_null(s->keyfile)) {
3696 logeventf(ssh, "Reading private key file \"%.150s\"",
3697 filename_to_str(s->keyfile));
3698 keytype = key_type(s->keyfile);
3699 if (keytype == SSH_KEYTYPE_SSH1) {
3701 if (rsakey_pubblob(s->keyfile,
3702 &s->publickey_blob, &s->publickey_bloblen,
3703 &s->publickey_comment, &error)) {
3704 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
3708 logeventf(ssh, "Unable to load private key (%s)", error);
3709 msgbuf = dupprintf("Unable to load private key file "
3710 "\"%.150s\" (%s)\r\n",
3711 filename_to_str(s->keyfile),
3713 c_write_str(ssh, msgbuf);
3715 s->publickey_blob = NULL;
3719 logeventf(ssh, "Unable to use this key file (%s)",
3720 key_type_to_str(keytype));
3721 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3723 filename_to_str(s->keyfile),
3724 key_type_to_str(keytype));
3725 c_write_str(ssh, msgbuf);
3727 s->publickey_blob = NULL;
3730 s->publickey_blob = NULL;
3732 while (pktin->type == SSH1_SMSG_FAILURE) {
3733 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3735 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
3737 * Attempt RSA authentication using Pageant.
3743 logevent("Pageant is running. Requesting keys.");
3745 /* Request the keys held by the agent. */
3746 PUT_32BIT(s->request, 1);
3747 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3748 if (!agent_query(s->request, 5, &r, &s->responselen,
3749 ssh_agent_callback, ssh)) {
3753 bombout(("Unexpected data from server while waiting"
3754 " for agent response"));
3757 } while (pktin || inlen > 0);
3758 r = ssh->agent_response;
3759 s->responselen = ssh->agent_response_len;
3761 s->response = (unsigned char *) r;
3762 if (s->response && s->responselen >= 5 &&
3763 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3764 s->p = s->response + 5;
3765 s->nkeys = toint(GET_32BIT(s->p));
3767 logeventf(ssh, "Pageant reported negative key count %d",
3772 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3773 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3774 unsigned char *pkblob = s->p;
3778 do { /* do while (0) to make breaking easy */
3779 n = ssh1_read_bignum
3780 (s->p, toint(s->responselen-(s->p-s->response)),
3785 n = ssh1_read_bignum
3786 (s->p, toint(s->responselen-(s->p-s->response)),
3791 if (s->responselen - (s->p-s->response) < 4)
3793 s->commentlen = toint(GET_32BIT(s->p));
3795 if (s->commentlen < 0 ||
3796 toint(s->responselen - (s->p-s->response)) <
3799 s->commentp = (char *)s->p;
3800 s->p += s->commentlen;
3804 logevent("Pageant key list packet was truncated");
3808 if (s->publickey_blob) {
3809 if (!memcmp(pkblob, s->publickey_blob,
3810 s->publickey_bloblen)) {
3811 logeventf(ssh, "Pageant key #%d matches "
3812 "configured key file", s->keyi);
3813 s->tried_publickey = 1;
3815 /* Skip non-configured key */
3818 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3819 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3820 PKT_BIGNUM, s->key.modulus, PKT_END);
3822 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3823 logevent("Key refused");
3826 logevent("Received RSA challenge");
3827 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3828 bombout(("Server's RSA challenge was badly formatted"));
3833 char *agentreq, *q, *ret;
3836 len = 1 + 4; /* message type, bit count */
3837 len += ssh1_bignum_length(s->key.exponent);
3838 len += ssh1_bignum_length(s->key.modulus);
3839 len += ssh1_bignum_length(s->challenge);
3840 len += 16; /* session id */
3841 len += 4; /* response format */
3842 agentreq = snewn(4 + len, char);
3843 PUT_32BIT(agentreq, len);
3845 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3846 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3848 q += ssh1_write_bignum(q, s->key.exponent);
3849 q += ssh1_write_bignum(q, s->key.modulus);
3850 q += ssh1_write_bignum(q, s->challenge);
3851 memcpy(q, s->session_id, 16);
3853 PUT_32BIT(q, 1); /* response format */
3854 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3855 ssh_agent_callback, ssh)) {
3860 bombout(("Unexpected data from server"
3861 " while waiting for agent"
3865 } while (pktin || inlen > 0);
3866 vret = ssh->agent_response;
3867 retlen = ssh->agent_response_len;
3872 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3873 logevent("Sending Pageant's response");
3874 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3875 PKT_DATA, ret + 5, 16,
3879 if (pktin->type == SSH1_SMSG_SUCCESS) {
3881 ("Pageant's response accepted");
3882 if (flags & FLAG_VERBOSE) {
3883 c_write_str(ssh, "Authenticated using"
3885 c_write(ssh, s->commentp,
3887 c_write_str(ssh, "\" from agent\r\n");
3892 ("Pageant's response not accepted");
3895 ("Pageant failed to answer challenge");
3899 logevent("No reply received from Pageant");
3902 freebn(s->key.exponent);
3903 freebn(s->key.modulus);
3904 freebn(s->challenge);
3909 if (s->publickey_blob && !s->tried_publickey)
3910 logevent("Configured key file not in Pageant");
3912 logevent("Failed to get reply from Pageant");
3917 if (s->publickey_blob && !s->tried_publickey) {
3919 * Try public key authentication with the specified
3922 int got_passphrase; /* need not be kept over crReturn */
3923 if (flags & FLAG_VERBOSE)
3924 c_write_str(ssh, "Trying public key authentication.\r\n");
3925 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3926 logeventf(ssh, "Trying public key \"%s\"",
3927 filename_to_str(s->keyfile));
3928 s->tried_publickey = 1;
3929 got_passphrase = FALSE;
3930 while (!got_passphrase) {
3932 * Get a passphrase, if necessary.
3934 char *passphrase = NULL; /* only written after crReturn */
3936 if (!s->publickey_encrypted) {
3937 if (flags & FLAG_VERBOSE)
3938 c_write_str(ssh, "No passphrase required.\r\n");
3941 int ret; /* need not be kept over crReturn */
3942 s->cur_prompt = new_prompts(ssh->frontend);
3943 s->cur_prompt->to_server = FALSE;
3944 s->cur_prompt->name = dupstr("SSH key passphrase");
3945 add_prompt(s->cur_prompt,
3946 dupprintf("Passphrase for key \"%.100s\": ",
3947 s->publickey_comment), FALSE);
3948 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3951 crWaitUntil(!pktin);
3952 ret = get_userpass_input(s->cur_prompt, in, inlen);
3956 /* Failed to get a passphrase. Terminate. */
3957 free_prompts(s->cur_prompt);
3958 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3962 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3963 free_prompts(s->cur_prompt);
3966 * Try decrypting key with passphrase.
3968 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3969 ret = loadrsakey(s->keyfile, &s->key, passphrase,
3972 smemclr(passphrase, strlen(passphrase));
3976 /* Correct passphrase. */
3977 got_passphrase = TRUE;
3978 } else if (ret == 0) {
3979 c_write_str(ssh, "Couldn't load private key from ");
3980 c_write_str(ssh, filename_to_str(s->keyfile));
3981 c_write_str(ssh, " (");
3982 c_write_str(ssh, error);
3983 c_write_str(ssh, ").\r\n");
3984 got_passphrase = FALSE;
3985 break; /* go and try something else */
3986 } else if (ret == -1) {
3987 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3988 got_passphrase = FALSE;
3991 assert(0 && "unexpected return from loadrsakey()");
3992 got_passphrase = FALSE; /* placate optimisers */
3996 if (got_passphrase) {
3999 * Send a public key attempt.
4001 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4002 PKT_BIGNUM, s->key.modulus, PKT_END);
4005 if (pktin->type == SSH1_SMSG_FAILURE) {
4006 c_write_str(ssh, "Server refused our public key.\r\n");
4007 continue; /* go and try something else */
4009 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4010 bombout(("Bizarre response to offer of public key"));
4016 unsigned char buffer[32];
4017 Bignum challenge, response;
4019 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4020 bombout(("Server's RSA challenge was badly formatted"));
4023 response = rsadecrypt(challenge, &s->key);
4024 freebn(s->key.private_exponent);/* burn the evidence */
4026 for (i = 0; i < 32; i++) {
4027 buffer[i] = bignum_byte(response, 31 - i);
4031 MD5Update(&md5c, buffer, 32);
4032 MD5Update(&md5c, s->session_id, 16);
4033 MD5Final(buffer, &md5c);
4035 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4036 PKT_DATA, buffer, 16, PKT_END);
4043 if (pktin->type == SSH1_SMSG_FAILURE) {
4044 if (flags & FLAG_VERBOSE)
4045 c_write_str(ssh, "Failed to authenticate with"
4046 " our public key.\r\n");
4047 continue; /* go and try something else */
4048 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4049 bombout(("Bizarre response to RSA authentication response"));
4053 break; /* we're through! */
4059 * Otherwise, try various forms of password-like authentication.
4061 s->cur_prompt = new_prompts(ssh->frontend);
4063 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4064 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4065 !s->tis_auth_refused) {
4066 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4067 logevent("Requested TIS authentication");
4068 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4070 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4071 logevent("TIS authentication declined");
4072 if (flags & FLAG_INTERACTIVE)
4073 c_write_str(ssh, "TIS authentication refused.\r\n");
4074 s->tis_auth_refused = 1;
4079 char *instr_suf, *prompt;
4081 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4083 bombout(("TIS challenge packet was badly formed"));
4086 logevent("Received TIS challenge");
4087 s->cur_prompt->to_server = TRUE;
4088 s->cur_prompt->name = dupstr("SSH TIS authentication");
4089 /* Prompt heuristic comes from OpenSSH */
4090 if (memchr(challenge, '\n', challengelen)) {
4091 instr_suf = dupstr("");
4092 prompt = dupprintf("%.*s", challengelen, challenge);
4094 instr_suf = dupprintf("%.*s", challengelen, challenge);
4095 prompt = dupstr("Response: ");
4097 s->cur_prompt->instruction =
4098 dupprintf("Using TIS authentication.%s%s",
4099 (*instr_suf) ? "\n" : "",
4101 s->cur_prompt->instr_reqd = TRUE;
4102 add_prompt(s->cur_prompt, prompt, FALSE);
4106 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4107 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4108 !s->ccard_auth_refused) {
4109 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4110 logevent("Requested CryptoCard authentication");
4111 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4113 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4114 logevent("CryptoCard authentication declined");
4115 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4116 s->ccard_auth_refused = 1;
4121 char *instr_suf, *prompt;
4123 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4125 bombout(("CryptoCard challenge packet was badly formed"));
4128 logevent("Received CryptoCard challenge");
4129 s->cur_prompt->to_server = TRUE;
4130 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4131 s->cur_prompt->name_reqd = FALSE;
4132 /* Prompt heuristic comes from OpenSSH */
4133 if (memchr(challenge, '\n', challengelen)) {
4134 instr_suf = dupstr("");
4135 prompt = dupprintf("%.*s", challengelen, challenge);
4137 instr_suf = dupprintf("%.*s", challengelen, challenge);
4138 prompt = dupstr("Response: ");
4140 s->cur_prompt->instruction =
4141 dupprintf("Using CryptoCard authentication.%s%s",
4142 (*instr_suf) ? "\n" : "",
4144 s->cur_prompt->instr_reqd = TRUE;
4145 add_prompt(s->cur_prompt, prompt, FALSE);
4149 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4150 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4151 bombout(("No supported authentication methods available"));
4154 s->cur_prompt->to_server = TRUE;
4155 s->cur_prompt->name = dupstr("SSH password");
4156 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4157 ssh->username, ssh->savedhost),
4162 * Show password prompt, having first obtained it via a TIS
4163 * or CryptoCard exchange if we're doing TIS or CryptoCard
4167 int ret; /* need not be kept over crReturn */
4168 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4171 crWaitUntil(!pktin);
4172 ret = get_userpass_input(s->cur_prompt, in, inlen);
4177 * Failed to get a password (for example
4178 * because one was supplied on the command line
4179 * which has already failed to work). Terminate.
4181 free_prompts(s->cur_prompt);
4182 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4187 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4189 * Defence against traffic analysis: we send a
4190 * whole bunch of packets containing strings of
4191 * different lengths. One of these strings is the
4192 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4193 * The others are all random data in
4194 * SSH1_MSG_IGNORE packets. This way a passive
4195 * listener can't tell which is the password, and
4196 * hence can't deduce the password length.
4198 * Anybody with a password length greater than 16
4199 * bytes is going to have enough entropy in their
4200 * password that a listener won't find it _that_
4201 * much help to know how long it is. So what we'll
4204 * - if password length < 16, we send 15 packets
4205 * containing string lengths 1 through 15
4207 * - otherwise, we let N be the nearest multiple
4208 * of 8 below the password length, and send 8
4209 * packets containing string lengths N through
4210 * N+7. This won't obscure the order of
4211 * magnitude of the password length, but it will
4212 * introduce a bit of extra uncertainty.
4214 * A few servers can't deal with SSH1_MSG_IGNORE, at
4215 * least in this context. For these servers, we need
4216 * an alternative defence. We make use of the fact
4217 * that the password is interpreted as a C string:
4218 * so we can append a NUL, then some random data.
4220 * A few servers can deal with neither SSH1_MSG_IGNORE
4221 * here _nor_ a padded password string.
4222 * For these servers we are left with no defences
4223 * against password length sniffing.
4225 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4226 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4228 * The server can deal with SSH1_MSG_IGNORE, so
4229 * we can use the primary defence.
4231 int bottom, top, pwlen, i;
4234 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4236 bottom = 0; /* zero length passwords are OK! :-) */
4239 bottom = pwlen & ~7;
4243 assert(pwlen >= bottom && pwlen <= top);
4245 randomstr = snewn(top + 1, char);
4247 for (i = bottom; i <= top; i++) {
4249 defer_packet(ssh, s->pwpkt_type,
4250 PKT_STR,s->cur_prompt->prompts[0]->result,
4253 for (j = 0; j < i; j++) {
4255 randomstr[j] = random_byte();
4256 } while (randomstr[j] == '\0');
4258 randomstr[i] = '\0';
4259 defer_packet(ssh, SSH1_MSG_IGNORE,
4260 PKT_STR, randomstr, PKT_END);
4263 logevent("Sending password with camouflage packets");
4264 ssh_pkt_defersend(ssh);
4267 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4269 * The server can't deal with SSH1_MSG_IGNORE
4270 * but can deal with padded passwords, so we
4271 * can use the secondary defence.
4277 len = strlen(s->cur_prompt->prompts[0]->result);
4278 if (len < sizeof(string)) {
4280 strcpy(string, s->cur_prompt->prompts[0]->result);
4281 len++; /* cover the zero byte */
4282 while (len < sizeof(string)) {
4283 string[len++] = (char) random_byte();
4286 ss = s->cur_prompt->prompts[0]->result;
4288 logevent("Sending length-padded password");
4289 send_packet(ssh, s->pwpkt_type,
4290 PKT_INT, len, PKT_DATA, ss, len,
4294 * The server is believed unable to cope with
4295 * any of our password camouflage methods.
4298 len = strlen(s->cur_prompt->prompts[0]->result);
4299 logevent("Sending unpadded password");
4300 send_packet(ssh, s->pwpkt_type,
4302 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4306 send_packet(ssh, s->pwpkt_type,
4307 PKT_STR, s->cur_prompt->prompts[0]->result,
4310 logevent("Sent password");
4311 free_prompts(s->cur_prompt);
4313 if (pktin->type == SSH1_SMSG_FAILURE) {
4314 if (flags & FLAG_VERBOSE)
4315 c_write_str(ssh, "Access denied\r\n");
4316 logevent("Authentication refused");
4317 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4318 bombout(("Strange packet received, type %d", pktin->type));
4324 if (s->publickey_blob) {
4325 sfree(s->publickey_blob);
4326 sfree(s->publickey_comment);
4329 logevent("Authentication successful");
4334 static void ssh_channel_try_eof(struct ssh_channel *c)
4337 assert(c->pending_eof); /* precondition for calling us */
4339 return; /* can't close: not even opened yet */
4340 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4341 return; /* can't send EOF: pending outgoing data */
4343 c->pending_eof = FALSE; /* we're about to send it */
4344 if (ssh->version == 1) {
4345 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4347 c->closes |= CLOSES_SENT_EOF;
4349 struct Packet *pktout;
4350 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4351 ssh2_pkt_adduint32(pktout, c->remoteid);
4352 ssh2_pkt_send(ssh, pktout);
4353 c->closes |= CLOSES_SENT_EOF;
4354 ssh2_channel_check_close(c);
4358 void sshfwd_write_eof(struct ssh_channel *c)
4362 if (ssh->state == SSH_STATE_CLOSED)
4365 if (c->closes & CLOSES_SENT_EOF)
4368 c->pending_eof = TRUE;
4369 ssh_channel_try_eof(c);
4372 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4376 if (ssh->state == SSH_STATE_CLOSED)
4381 x11_close(c->u.x11.xconn);
4382 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4386 case CHAN_SOCKDATA_DORMANT:
4387 pfd_close(c->u.pfd.pf);
4388 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4391 c->type = CHAN_ZOMBIE;
4392 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4394 ssh2_channel_check_close(c);
4397 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4401 if (ssh->state == SSH_STATE_CLOSED)
4404 if (ssh->version == 1) {
4405 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4406 PKT_INT, c->remoteid,
4407 PKT_INT, len, PKT_DATA, buf, len,
4410 * In SSH-1 we can return 0 here - implying that forwarded
4411 * connections are never individually throttled - because
4412 * the only circumstance that can cause throttling will be
4413 * the whole SSH connection backing up, in which case
4414 * _everything_ will be throttled as a whole.
4418 ssh2_add_channel_data(c, buf, len);
4419 return ssh2_try_send(c);
4423 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4428 if (ssh->state == SSH_STATE_CLOSED)
4431 if (ssh->version == 1) {
4432 buflimit = SSH1_BUFFER_LIMIT;
4434 buflimit = c->v.v2.locmaxwin;
4435 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4437 if (c->throttling_conn && bufsize <= buflimit) {
4438 c->throttling_conn = 0;
4439 ssh_throttle_conn(ssh, -1);
4443 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4445 struct queued_handler *qh = ssh->qhead;
4449 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4452 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4453 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4456 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4457 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4461 ssh->qhead = qh->next;
4463 if (ssh->qhead->msg1 > 0) {
4464 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4465 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4467 if (ssh->qhead->msg2 > 0) {
4468 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4469 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4472 ssh->qhead = ssh->qtail = NULL;
4475 qh->handler(ssh, pktin, qh->ctx);
4480 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4481 chandler_fn_t handler, void *ctx)
4483 struct queued_handler *qh;
4485 qh = snew(struct queued_handler);
4488 qh->handler = handler;
4492 if (ssh->qtail == NULL) {
4496 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4497 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4500 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4501 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4504 ssh->qtail->next = qh;
4509 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4511 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4513 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4514 SSH2_MSG_REQUEST_SUCCESS)) {
4515 logeventf(ssh, "Remote port forwarding from %s enabled",
4518 logeventf(ssh, "Remote port forwarding from %s refused",
4521 rpf = del234(ssh->rportfwds, pf);
4523 pf->pfrec->remote = NULL;
4528 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4530 struct ssh_portfwd *epf;
4534 if (!ssh->portfwds) {
4535 ssh->portfwds = newtree234(ssh_portcmp);
4538 * Go through the existing port forwardings and tag them
4539 * with status==DESTROY. Any that we want to keep will be
4540 * re-enabled (status==KEEP) as we go through the
4541 * configuration and find out which bits are the same as
4544 struct ssh_portfwd *epf;
4546 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4547 epf->status = DESTROY;
4550 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4552 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4553 char *kp, *kp2, *vp, *vp2;
4554 char address_family, type;
4555 int sport,dport,sserv,dserv;
4556 char *sports, *dports, *saddr, *host;
4560 address_family = 'A';
4562 if (*kp == 'A' || *kp == '4' || *kp == '6')
4563 address_family = *kp++;
4564 if (*kp == 'L' || *kp == 'R')
4567 if ((kp2 = strchr(kp, ':')) != NULL) {
4569 * There's a colon in the middle of the source port
4570 * string, which means that the part before it is
4571 * actually a source address.
4573 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4579 sport = atoi(sports);
4583 sport = net_service_lookup(sports);
4585 logeventf(ssh, "Service lookup failed for source"
4586 " port \"%s\"", sports);
4590 if (type == 'L' && !strcmp(val, "D")) {
4591 /* dynamic forwarding */
4598 /* ordinary forwarding */
4600 vp2 = vp + strcspn(vp, ":");
4601 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4605 dport = atoi(dports);
4609 dport = net_service_lookup(dports);
4611 logeventf(ssh, "Service lookup failed for destination"
4612 " port \"%s\"", dports);
4617 if (sport && dport) {
4618 /* Set up a description of the source port. */
4619 struct ssh_portfwd *pfrec, *epfrec;
4621 pfrec = snew(struct ssh_portfwd);
4623 pfrec->saddr = saddr;
4624 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4625 pfrec->sport = sport;
4626 pfrec->daddr = host;
4627 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4628 pfrec->dport = dport;
4629 pfrec->local = NULL;
4630 pfrec->remote = NULL;
4631 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4632 address_family == '6' ? ADDRTYPE_IPV6 :
4635 epfrec = add234(ssh->portfwds, pfrec);
4636 if (epfrec != pfrec) {
4637 if (epfrec->status == DESTROY) {
4639 * We already have a port forwarding up and running
4640 * with precisely these parameters. Hence, no need
4641 * to do anything; simply re-tag the existing one
4644 epfrec->status = KEEP;
4647 * Anything else indicates that there was a duplicate
4648 * in our input, which we'll silently ignore.
4650 free_portfwd(pfrec);
4652 pfrec->status = CREATE;
4661 * Now go through and destroy any port forwardings which were
4664 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4665 if (epf->status == DESTROY) {
4668 message = dupprintf("%s port forwarding from %s%s%d",
4669 epf->type == 'L' ? "local" :
4670 epf->type == 'R' ? "remote" : "dynamic",
4671 epf->saddr ? epf->saddr : "",
4672 epf->saddr ? ":" : "",
4675 if (epf->type != 'D') {
4676 char *msg2 = dupprintf("%s to %s:%d", message,
4677 epf->daddr, epf->dport);
4682 logeventf(ssh, "Cancelling %s", message);
4685 /* epf->remote or epf->local may be NULL if setting up a
4686 * forwarding failed. */
4688 struct ssh_rportfwd *rpf = epf->remote;
4689 struct Packet *pktout;
4692 * Cancel the port forwarding at the server
4695 if (ssh->version == 1) {
4697 * We cannot cancel listening ports on the
4698 * server side in SSH-1! There's no message
4699 * to support it. Instead, we simply remove
4700 * the rportfwd record from the local end
4701 * so that any connections the server tries
4702 * to make on it are rejected.
4705 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4706 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4707 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4709 ssh2_pkt_addstring(pktout, epf->saddr);
4710 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4711 /* XXX: rport_acceptall may not represent
4712 * what was used to open the original connection,
4713 * since it's reconfigurable. */
4714 ssh2_pkt_addstring(pktout, "");
4716 ssh2_pkt_addstring(pktout, "localhost");
4718 ssh2_pkt_adduint32(pktout, epf->sport);
4719 ssh2_pkt_send(ssh, pktout);
4722 del234(ssh->rportfwds, rpf);
4724 } else if (epf->local) {
4725 pfl_terminate(epf->local);
4728 delpos234(ssh->portfwds, i);
4730 i--; /* so we don't skip one in the list */
4734 * And finally, set up any new port forwardings (status==CREATE).
4736 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4737 if (epf->status == CREATE) {
4738 char *sportdesc, *dportdesc;
4739 sportdesc = dupprintf("%s%s%s%s%d%s",
4740 epf->saddr ? epf->saddr : "",
4741 epf->saddr ? ":" : "",
4742 epf->sserv ? epf->sserv : "",
4743 epf->sserv ? "(" : "",
4745 epf->sserv ? ")" : "");
4746 if (epf->type == 'D') {
4749 dportdesc = dupprintf("%s:%s%s%d%s",
4751 epf->dserv ? epf->dserv : "",
4752 epf->dserv ? "(" : "",
4754 epf->dserv ? ")" : "");
4757 if (epf->type == 'L') {
4758 char *err = pfl_listen(epf->daddr, epf->dport,
4759 epf->saddr, epf->sport,
4760 ssh, conf, &epf->local,
4761 epf->addressfamily);
4763 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4764 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4765 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4766 sportdesc, dportdesc,
4767 err ? " failed: " : "", err ? err : "");
4770 } else if (epf->type == 'D') {
4771 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
4772 ssh, conf, &epf->local,
4773 epf->addressfamily);
4775 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4776 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4777 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4779 err ? " failed: " : "", err ? err : "");
4784 struct ssh_rportfwd *pf;
4787 * Ensure the remote port forwardings tree exists.
4789 if (!ssh->rportfwds) {
4790 if (ssh->version == 1)
4791 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4793 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4796 pf = snew(struct ssh_rportfwd);
4797 pf->dhost = dupstr(epf->daddr);
4798 pf->dport = epf->dport;
4800 pf->shost = dupstr(epf->saddr);
4801 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4802 pf->shost = dupstr("");
4804 pf->shost = dupstr("localhost");
4806 pf->sport = epf->sport;
4807 if (add234(ssh->rportfwds, pf) != pf) {
4808 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4809 epf->daddr, epf->dport);
4812 logeventf(ssh, "Requesting remote port %s"
4813 " forward to %s", sportdesc, dportdesc);
4815 pf->sportdesc = sportdesc;
4820 if (ssh->version == 1) {
4821 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4822 PKT_INT, epf->sport,
4823 PKT_STR, epf->daddr,
4824 PKT_INT, epf->dport,
4826 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4828 ssh_rportfwd_succfail, pf);
4830 struct Packet *pktout;
4831 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4832 ssh2_pkt_addstring(pktout, "tcpip-forward");
4833 ssh2_pkt_addbool(pktout, 1);/* want reply */
4834 ssh2_pkt_addstring(pktout, pf->shost);
4835 ssh2_pkt_adduint32(pktout, pf->sport);
4836 ssh2_pkt_send(ssh, pktout);
4838 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4839 SSH2_MSG_REQUEST_FAILURE,
4840 ssh_rportfwd_succfail, pf);
4849 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4852 int stringlen, bufsize;
4854 ssh_pkt_getstring(pktin, &string, &stringlen);
4855 if (string == NULL) {
4856 bombout(("Incoming terminal data packet was badly formed"));
4860 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4862 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4863 ssh->v1_stdout_throttling = 1;
4864 ssh_throttle_conn(ssh, +1);
4868 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4870 /* Remote side is trying to open a channel to talk to our
4871 * X-Server. Give them back a local channel number. */
4872 struct ssh_channel *c;
4873 int remoteid = ssh_pkt_getuint32(pktin);
4875 logevent("Received X11 connect request");
4876 /* Refuse if X11 forwarding is disabled. */
4877 if (!ssh->X11_fwd_enabled) {
4878 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4879 PKT_INT, remoteid, PKT_END);
4880 logevent("Rejected X11 connect request");
4884 c = snew(struct ssh_channel);
4887 if ((err = x11_init(&c->u.x11.xconn, ssh->x11disp, c,
4888 NULL, -1, ssh->conf)) != NULL) {
4889 logeventf(ssh, "Opening X11 forward connection failed: %s", err);
4892 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4893 PKT_INT, remoteid, PKT_END);
4896 ("Opening X11 forward connection succeeded");
4897 c->remoteid = remoteid;
4898 c->halfopen = FALSE;
4899 c->localid = alloc_channel_id(ssh);
4901 c->pending_eof = FALSE;
4902 c->throttling_conn = 0;
4903 c->type = CHAN_X11; /* identify channel type */
4904 add234(ssh->channels, c);
4905 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4906 PKT_INT, c->remoteid, PKT_INT,
4907 c->localid, PKT_END);
4908 logevent("Opened X11 forward channel");
4913 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4915 /* Remote side is trying to open a channel to talk to our
4916 * agent. Give them back a local channel number. */
4917 struct ssh_channel *c;
4918 int remoteid = ssh_pkt_getuint32(pktin);
4920 /* Refuse if agent forwarding is disabled. */
4921 if (!ssh->agentfwd_enabled) {
4922 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4923 PKT_INT, remoteid, PKT_END);
4925 c = snew(struct ssh_channel);
4927 c->remoteid = remoteid;
4928 c->halfopen = FALSE;
4929 c->localid = alloc_channel_id(ssh);
4931 c->pending_eof = FALSE;
4932 c->throttling_conn = 0;
4933 c->type = CHAN_AGENT; /* identify channel type */
4934 c->u.a.lensofar = 0;
4935 c->u.a.message = NULL;
4936 c->u.a.outstanding_requests = 0;
4937 add234(ssh->channels, c);
4938 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4939 PKT_INT, c->remoteid, PKT_INT, c->localid,
4944 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4946 /* Remote side is trying to open a channel to talk to a
4947 * forwarded port. Give them back a local channel number. */
4948 struct ssh_rportfwd pf, *pfp;
4954 remoteid = ssh_pkt_getuint32(pktin);
4955 ssh_pkt_getstring(pktin, &host, &hostsize);
4956 port = ssh_pkt_getuint32(pktin);
4958 pf.dhost = dupprintf(".*s", hostsize, host);
4960 pfp = find234(ssh->rportfwds, &pf, NULL);
4963 logeventf(ssh, "Rejected remote port open request for %s:%d",
4965 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4966 PKT_INT, remoteid, PKT_END);
4968 struct ssh_channel *c = snew(struct ssh_channel);
4971 logeventf(ssh, "Received remote port open request for %s:%d",
4973 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
4974 c, ssh->conf, pfp->pfrec->addressfamily);
4976 logeventf(ssh, "Port open failed: %s", err);
4979 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4980 PKT_INT, remoteid, PKT_END);
4982 c->remoteid = remoteid;
4983 c->halfopen = FALSE;
4984 c->localid = alloc_channel_id(ssh);
4986 c->pending_eof = FALSE;
4987 c->throttling_conn = 0;
4988 c->type = CHAN_SOCKDATA; /* identify channel type */
4989 add234(ssh->channels, c);
4990 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4991 PKT_INT, c->remoteid, PKT_INT,
4992 c->localid, PKT_END);
4993 logevent("Forwarded port opened successfully");
5000 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5002 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5003 unsigned int localid = ssh_pkt_getuint32(pktin);
5004 struct ssh_channel *c;
5006 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5007 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5008 c->remoteid = localid;
5009 c->halfopen = FALSE;
5010 c->type = CHAN_SOCKDATA;
5011 c->throttling_conn = 0;
5012 pfd_confirm(c->u.pfd.pf);
5015 if (c && c->pending_eof) {
5017 * We have a pending close on this channel,
5018 * which we decided on before the server acked
5019 * the channel open. So now we know the
5020 * remoteid, we can close it again.
5022 ssh_channel_try_eof(c);
5026 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5028 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5029 struct ssh_channel *c;
5031 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5032 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5033 logevent("Forwarded connection refused by server");
5034 pfd_close(c->u.pfd.pf);
5035 del234(ssh->channels, c);
5040 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5042 /* Remote side closes a channel. */
5043 unsigned i = ssh_pkt_getuint32(pktin);
5044 struct ssh_channel *c;
5045 c = find234(ssh->channels, &i, ssh_channelfind);
5046 if (c && !c->halfopen) {
5048 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5049 !(c->closes & CLOSES_RCVD_EOF)) {
5051 * Received CHANNEL_CLOSE, which we translate into
5054 int send_close = FALSE;
5056 c->closes |= CLOSES_RCVD_EOF;
5061 x11_send_eof(c->u.x11.xconn);
5067 pfd_send_eof(c->u.pfd.pf);
5076 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5077 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5079 c->closes |= CLOSES_SENT_EOF;
5083 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5084 !(c->closes & CLOSES_RCVD_CLOSE)) {
5086 if (!(c->closes & CLOSES_SENT_EOF)) {
5087 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5088 " for which we never sent CHANNEL_CLOSE\n", i));
5091 c->closes |= CLOSES_RCVD_CLOSE;
5094 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5095 !(c->closes & CLOSES_SENT_CLOSE)) {
5096 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5097 PKT_INT, c->remoteid, PKT_END);
5098 c->closes |= CLOSES_SENT_CLOSE;
5101 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5102 ssh_channel_destroy(c);
5104 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5105 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5106 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5111 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5113 /* Data sent down one of our channels. */
5114 int i = ssh_pkt_getuint32(pktin);
5117 struct ssh_channel *c;
5119 ssh_pkt_getstring(pktin, &p, &len);
5121 c = find234(ssh->channels, &i, ssh_channelfind);
5126 bufsize = x11_send(c->u.x11.xconn, p, len);
5129 bufsize = pfd_send(c->u.pfd.pf, p, len);
5132 /* Data for an agent message. Buffer it. */
5134 if (c->u.a.lensofar < 4) {
5135 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5136 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5140 c->u.a.lensofar += l;
5142 if (c->u.a.lensofar == 4) {
5144 4 + GET_32BIT(c->u.a.msglen);
5145 c->u.a.message = snewn(c->u.a.totallen,
5147 memcpy(c->u.a.message, c->u.a.msglen, 4);
5149 if (c->u.a.lensofar >= 4 && len > 0) {
5151 min(c->u.a.totallen - c->u.a.lensofar,
5153 memcpy(c->u.a.message + c->u.a.lensofar, p,
5157 c->u.a.lensofar += l;
5159 if (c->u.a.lensofar == c->u.a.totallen) {
5162 c->u.a.outstanding_requests++;
5163 if (agent_query(c->u.a.message,
5166 ssh_agentf_callback, c))
5167 ssh_agentf_callback(c, reply, replylen);
5168 sfree(c->u.a.message);
5169 c->u.a.lensofar = 0;
5172 bufsize = 0; /* agent channels never back up */
5175 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5176 c->throttling_conn = 1;
5177 ssh_throttle_conn(ssh, +1);
5182 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5184 ssh->exitcode = ssh_pkt_getuint32(pktin);
5185 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5186 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5188 * In case `helpful' firewalls or proxies tack
5189 * extra human-readable text on the end of the
5190 * session which we might mistake for another
5191 * encrypted packet, we close the session once
5192 * we've sent EXIT_CONFIRMATION.
5194 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5197 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5198 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5200 struct Packet *pktout = (struct Packet *)data;
5202 unsigned int arg = 0;
5203 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5204 if (i == lenof(ssh_ttymodes)) return;
5205 switch (ssh_ttymodes[i].type) {
5207 arg = ssh_tty_parse_specchar(val);
5210 arg = ssh_tty_parse_boolean(val);
5213 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5214 ssh2_pkt_addbyte(pktout, arg);
5218 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5219 struct Packet *pktin)
5221 crBegin(ssh->do_ssh1_connection_crstate);
5223 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5224 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5225 ssh1_smsg_stdout_stderr_data;
5227 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5228 ssh1_msg_channel_open_confirmation;
5229 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5230 ssh1_msg_channel_open_failure;
5231 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5232 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5233 ssh1_msg_channel_close;
5234 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5235 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5237 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5238 logevent("Requesting agent forwarding");
5239 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5243 if (pktin->type != SSH1_SMSG_SUCCESS
5244 && pktin->type != SSH1_SMSG_FAILURE) {
5245 bombout(("Protocol confusion"));
5247 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5248 logevent("Agent forwarding refused");
5250 logevent("Agent forwarding enabled");
5251 ssh->agentfwd_enabled = TRUE;
5252 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5256 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5257 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5258 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5259 logevent("Requesting X11 forwarding");
5260 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5261 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5262 PKT_STR, ssh->x11disp->remoteauthprotoname,
5263 PKT_STR, ssh->x11disp->remoteauthdatastring,
5264 PKT_INT, ssh->x11disp->screennum,
5267 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5268 PKT_STR, ssh->x11disp->remoteauthprotoname,
5269 PKT_STR, ssh->x11disp->remoteauthdatastring,
5275 if (pktin->type != SSH1_SMSG_SUCCESS
5276 && pktin->type != SSH1_SMSG_FAILURE) {
5277 bombout(("Protocol confusion"));
5279 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5280 logevent("X11 forwarding refused");
5282 logevent("X11 forwarding enabled");
5283 ssh->X11_fwd_enabled = TRUE;
5284 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5288 ssh_setup_portfwd(ssh, ssh->conf);
5289 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5291 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5293 /* Unpick the terminal-speed string. */
5294 /* XXX perhaps we should allow no speeds to be sent. */
5295 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5296 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5297 /* Send the pty request. */
5298 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5299 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5300 ssh_pkt_adduint32(pkt, ssh->term_height);
5301 ssh_pkt_adduint32(pkt, ssh->term_width);
5302 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5303 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5304 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5305 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5306 ssh_pkt_adduint32(pkt, ssh->ispeed);
5307 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5308 ssh_pkt_adduint32(pkt, ssh->ospeed);
5309 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5311 ssh->state = SSH_STATE_INTERMED;
5315 if (pktin->type != SSH1_SMSG_SUCCESS
5316 && pktin->type != SSH1_SMSG_FAILURE) {
5317 bombout(("Protocol confusion"));
5319 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5320 c_write_str(ssh, "Server refused to allocate pty\r\n");
5321 ssh->editing = ssh->echoing = 1;
5323 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5324 ssh->ospeed, ssh->ispeed);
5325 ssh->got_pty = TRUE;
5328 ssh->editing = ssh->echoing = 1;
5331 if (conf_get_int(ssh->conf, CONF_compression)) {
5332 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5336 if (pktin->type != SSH1_SMSG_SUCCESS
5337 && pktin->type != SSH1_SMSG_FAILURE) {
5338 bombout(("Protocol confusion"));
5340 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5341 c_write_str(ssh, "Server refused to compress\r\n");
5343 logevent("Started compression");
5344 ssh->v1_compressing = TRUE;
5345 ssh->cs_comp_ctx = zlib_compress_init();
5346 logevent("Initialised zlib (RFC1950) compression");
5347 ssh->sc_comp_ctx = zlib_decompress_init();
5348 logevent("Initialised zlib (RFC1950) decompression");
5352 * Start the shell or command.
5354 * Special case: if the first-choice command is an SSH-2
5355 * subsystem (hence not usable here) and the second choice
5356 * exists, we fall straight back to that.
5359 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5361 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5362 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5363 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5364 ssh->fallback_cmd = TRUE;
5367 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5369 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5370 logevent("Started session");
5373 ssh->state = SSH_STATE_SESSION;
5374 if (ssh->size_needed)
5375 ssh_size(ssh, ssh->term_width, ssh->term_height);
5376 if (ssh->eof_needed)
5377 ssh_special(ssh, TS_EOF);
5380 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5382 ssh->channels = newtree234(ssh_channelcmp);
5386 * By this point, most incoming packets are already being
5387 * handled by the dispatch table, and we need only pay
5388 * attention to the unusual ones.
5393 if (pktin->type == SSH1_SMSG_SUCCESS) {
5394 /* may be from EXEC_SHELL on some servers */
5395 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5396 /* may be from EXEC_SHELL on some servers
5397 * if no pty is available or in other odd cases. Ignore */
5399 bombout(("Strange packet received: type %d", pktin->type));
5404 int len = min(inlen, 512);
5405 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5406 PKT_INT, len, PKT_DATA, in, len,
5418 * Handle the top-level SSH-2 protocol.
5420 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5425 ssh_pkt_getstring(pktin, &msg, &msglen);
5426 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5429 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5431 /* log reason code in disconnect message */
5435 ssh_pkt_getstring(pktin, &msg, &msglen);
5436 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5439 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5441 /* Do nothing, because we're ignoring it! Duhh. */
5444 static void ssh1_protocol_setup(Ssh ssh)
5449 * Most messages are handled by the coroutines.
5451 for (i = 0; i < 256; i++)
5452 ssh->packet_dispatch[i] = NULL;
5455 * These special message types we install handlers for.
5457 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5458 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5459 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5462 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5463 struct Packet *pktin)
5465 unsigned char *in=(unsigned char*)vin;
5466 if (ssh->state == SSH_STATE_CLOSED)
5469 if (pktin && ssh->packet_dispatch[pktin->type]) {
5470 ssh->packet_dispatch[pktin->type](ssh, pktin);
5474 if (!ssh->protocol_initial_phase_done) {
5475 if (do_ssh1_login(ssh, in, inlen, pktin))
5476 ssh->protocol_initial_phase_done = TRUE;
5481 do_ssh1_connection(ssh, in, inlen, pktin);
5485 * Utility routine for decoding comma-separated strings in KEXINIT.
5487 static int in_commasep_string(char *needle, char *haystack, int haylen)
5490 if (!needle || !haystack) /* protect against null pointers */
5492 needlen = strlen(needle);
5495 * Is it at the start of the string?
5497 if (haylen >= needlen && /* haystack is long enough */
5498 !memcmp(needle, haystack, needlen) && /* initial match */
5499 (haylen == needlen || haystack[needlen] == ',')
5500 /* either , or EOS follows */
5504 * If not, search for the next comma and resume after that.
5505 * If no comma found, terminate.
5507 while (haylen > 0 && *haystack != ',')
5508 haylen--, haystack++;
5511 haylen--, haystack++; /* skip over comma itself */
5516 * Similar routine for checking whether we have the first string in a list.
5518 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5521 if (!needle || !haystack) /* protect against null pointers */
5523 needlen = strlen(needle);
5525 * Is it at the start of the string?
5527 if (haylen >= needlen && /* haystack is long enough */
5528 !memcmp(needle, haystack, needlen) && /* initial match */
5529 (haylen == needlen || haystack[needlen] == ',')
5530 /* either , or EOS follows */
5538 * SSH-2 key creation method.
5539 * (Currently assumes 2 lots of any hash are sufficient to generate
5540 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5542 #define SSH2_MKKEY_ITERS (2)
5543 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5544 unsigned char *keyspace)
5546 const struct ssh_hash *h = ssh->kex->hash;
5548 /* First 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, &chr, 1);
5554 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5555 h->final(s, keyspace);
5556 /* Next hlen bytes. */
5558 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5559 hash_mpint(h, s, K);
5560 h->bytes(s, H, h->hlen);
5561 h->bytes(s, keyspace, h->hlen);
5562 h->final(s, keyspace + h->hlen);
5566 * Handle the SSH-2 transport layer.
5568 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5569 struct Packet *pktin)
5571 unsigned char *in = (unsigned char *)vin;
5572 struct do_ssh2_transport_state {
5574 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5575 Bignum p, g, e, f, K;
5578 int kex_init_value, kex_reply_value;
5579 const struct ssh_mac **maclist;
5581 const struct ssh2_cipher *cscipher_tobe;
5582 const struct ssh2_cipher *sccipher_tobe;
5583 const struct ssh_mac *csmac_tobe;
5584 const struct ssh_mac *scmac_tobe;
5585 const struct ssh_compress *cscomp_tobe;
5586 const struct ssh_compress *sccomp_tobe;
5587 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5588 int hostkeylen, siglen, rsakeylen;
5589 void *hkey; /* actual host key */
5590 void *rsakey; /* for RSA kex */
5591 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5592 int n_preferred_kex;
5593 const struct ssh_kexes *preferred_kex[KEX_MAX];
5594 int n_preferred_ciphers;
5595 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5596 const struct ssh_compress *preferred_comp;
5597 int userauth_succeeded; /* for delayed compression */
5598 int pending_compression;
5599 int got_session_id, activated_authconn;
5600 struct Packet *pktout;
5605 crState(do_ssh2_transport_state);
5609 s->cscipher_tobe = s->sccipher_tobe = NULL;
5610 s->csmac_tobe = s->scmac_tobe = NULL;
5611 s->cscomp_tobe = s->sccomp_tobe = NULL;
5613 s->got_session_id = s->activated_authconn = FALSE;
5614 s->userauth_succeeded = FALSE;
5615 s->pending_compression = FALSE;
5618 * Be prepared to work around the buggy MAC problem.
5620 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5621 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5623 s->maclist = macs, s->nmacs = lenof(macs);
5626 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5628 int i, j, k, commalist_started;
5631 * Set up the preferred key exchange. (NULL => warn below here)
5633 s->n_preferred_kex = 0;
5634 for (i = 0; i < KEX_MAX; i++) {
5635 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5637 s->preferred_kex[s->n_preferred_kex++] =
5638 &ssh_diffiehellman_gex;
5641 s->preferred_kex[s->n_preferred_kex++] =
5642 &ssh_diffiehellman_group14;
5645 s->preferred_kex[s->n_preferred_kex++] =
5646 &ssh_diffiehellman_group1;
5649 s->preferred_kex[s->n_preferred_kex++] =
5653 /* Flag for later. Don't bother if it's the last in
5655 if (i < KEX_MAX - 1) {
5656 s->preferred_kex[s->n_preferred_kex++] = NULL;
5663 * Set up the preferred ciphers. (NULL => warn below here)
5665 s->n_preferred_ciphers = 0;
5666 for (i = 0; i < CIPHER_MAX; i++) {
5667 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5668 case CIPHER_BLOWFISH:
5669 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5672 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5673 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5677 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5680 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5682 case CIPHER_ARCFOUR:
5683 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5686 /* Flag for later. Don't bother if it's the last in
5688 if (i < CIPHER_MAX - 1) {
5689 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5696 * Set up preferred compression.
5698 if (conf_get_int(ssh->conf, CONF_compression))
5699 s->preferred_comp = &ssh_zlib;
5701 s->preferred_comp = &ssh_comp_none;
5704 * Enable queueing of outgoing auth- or connection-layer
5705 * packets while we are in the middle of a key exchange.
5707 ssh->queueing = TRUE;
5710 * Flag that KEX is in progress.
5712 ssh->kex_in_progress = TRUE;
5715 * Construct and send our key exchange packet.
5717 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5718 for (i = 0; i < 16; i++)
5719 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5720 /* List key exchange algorithms. */
5721 ssh2_pkt_addstring_start(s->pktout);
5722 commalist_started = 0;
5723 for (i = 0; i < s->n_preferred_kex; i++) {
5724 const struct ssh_kexes *k = s->preferred_kex[i];
5725 if (!k) continue; /* warning flag */
5726 for (j = 0; j < k->nkexes; j++) {
5727 if (commalist_started)
5728 ssh2_pkt_addstring_str(s->pktout, ",");
5729 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5730 commalist_started = 1;
5733 /* List server host key algorithms. */
5734 if (!s->got_session_id) {
5736 * In the first key exchange, we list all the algorithms
5737 * we're prepared to cope with.
5739 ssh2_pkt_addstring_start(s->pktout);
5740 for (i = 0; i < lenof(hostkey_algs); i++) {
5741 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5742 if (i < lenof(hostkey_algs) - 1)
5743 ssh2_pkt_addstring_str(s->pktout, ",");
5747 * In subsequent key exchanges, we list only the kex
5748 * algorithm that was selected in the first key exchange,
5749 * so that we keep getting the same host key and hence
5750 * don't have to interrupt the user's session to ask for
5754 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5756 /* List encryption algorithms (client->server then server->client). */
5757 for (k = 0; k < 2; k++) {
5758 ssh2_pkt_addstring_start(s->pktout);
5759 commalist_started = 0;
5760 for (i = 0; i < s->n_preferred_ciphers; i++) {
5761 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5762 if (!c) continue; /* warning flag */
5763 for (j = 0; j < c->nciphers; j++) {
5764 if (commalist_started)
5765 ssh2_pkt_addstring_str(s->pktout, ",");
5766 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5767 commalist_started = 1;
5771 /* List MAC algorithms (client->server then server->client). */
5772 for (j = 0; j < 2; j++) {
5773 ssh2_pkt_addstring_start(s->pktout);
5774 for (i = 0; i < s->nmacs; i++) {
5775 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5776 if (i < s->nmacs - 1)
5777 ssh2_pkt_addstring_str(s->pktout, ",");
5780 /* List client->server compression algorithms,
5781 * then server->client compression algorithms. (We use the
5782 * same set twice.) */
5783 for (j = 0; j < 2; j++) {
5784 ssh2_pkt_addstring_start(s->pktout);
5785 assert(lenof(compressions) > 1);
5786 /* Prefer non-delayed versions */
5787 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5788 /* We don't even list delayed versions of algorithms until
5789 * they're allowed to be used, to avoid a race. See the end of
5791 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5792 ssh2_pkt_addstring_str(s->pktout, ",");
5793 ssh2_pkt_addstring_str(s->pktout,
5794 s->preferred_comp->delayed_name);
5796 for (i = 0; i < lenof(compressions); i++) {
5797 const struct ssh_compress *c = compressions[i];
5798 if (c != s->preferred_comp) {
5799 ssh2_pkt_addstring_str(s->pktout, ",");
5800 ssh2_pkt_addstring_str(s->pktout, c->name);
5801 if (s->userauth_succeeded && c->delayed_name) {
5802 ssh2_pkt_addstring_str(s->pktout, ",");
5803 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5808 /* List client->server languages. Empty list. */
5809 ssh2_pkt_addstring_start(s->pktout);
5810 /* List server->client languages. Empty list. */
5811 ssh2_pkt_addstring_start(s->pktout);
5812 /* First KEX packet does _not_ follow, because we're not that brave. */
5813 ssh2_pkt_addbool(s->pktout, FALSE);
5815 ssh2_pkt_adduint32(s->pktout, 0);
5818 s->our_kexinitlen = s->pktout->length - 5;
5819 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5820 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5822 ssh2_pkt_send_noqueue(ssh, s->pktout);
5825 crWaitUntilV(pktin);
5828 * Now examine the other side's KEXINIT to see what we're up
5832 char *str, *preferred;
5835 if (pktin->type != SSH2_MSG_KEXINIT) {
5836 bombout(("expected key exchange packet from server"));
5840 ssh->hostkey = NULL;
5841 s->cscipher_tobe = NULL;
5842 s->sccipher_tobe = NULL;
5843 s->csmac_tobe = NULL;
5844 s->scmac_tobe = NULL;
5845 s->cscomp_tobe = NULL;
5846 s->sccomp_tobe = NULL;
5847 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5849 pktin->savedpos += 16; /* skip garbage cookie */
5850 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5853 for (i = 0; i < s->n_preferred_kex; i++) {
5854 const struct ssh_kexes *k = s->preferred_kex[i];
5858 for (j = 0; j < k->nkexes; j++) {
5859 if (!preferred) preferred = k->list[j]->name;
5860 if (in_commasep_string(k->list[j]->name, str, len)) {
5861 ssh->kex = k->list[j];
5870 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5871 str ? str : "(null)"));
5875 * Note that the server's guess is considered wrong if it doesn't match
5876 * the first algorithm in our list, even if it's still the algorithm
5879 s->guessok = first_in_commasep_string(preferred, str, len);
5880 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5881 for (i = 0; i < lenof(hostkey_algs); i++) {
5882 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5883 ssh->hostkey = hostkey_algs[i];
5887 if (!ssh->hostkey) {
5888 bombout(("Couldn't agree a host key algorithm (available: %s)",
5889 str ? str : "(null)"));
5893 s->guessok = s->guessok &&
5894 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5895 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5896 for (i = 0; i < s->n_preferred_ciphers; i++) {
5897 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5899 s->warn_cscipher = TRUE;
5901 for (j = 0; j < c->nciphers; j++) {
5902 if (in_commasep_string(c->list[j]->name, str, len)) {
5903 s->cscipher_tobe = c->list[j];
5908 if (s->cscipher_tobe)
5911 if (!s->cscipher_tobe) {
5912 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5913 str ? str : "(null)"));
5917 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5918 for (i = 0; i < s->n_preferred_ciphers; i++) {
5919 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5921 s->warn_sccipher = TRUE;
5923 for (j = 0; j < c->nciphers; j++) {
5924 if (in_commasep_string(c->list[j]->name, str, len)) {
5925 s->sccipher_tobe = c->list[j];
5930 if (s->sccipher_tobe)
5933 if (!s->sccipher_tobe) {
5934 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5935 str ? str : "(null)"));
5939 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5940 for (i = 0; i < s->nmacs; i++) {
5941 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5942 s->csmac_tobe = s->maclist[i];
5946 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5947 for (i = 0; i < s->nmacs; i++) {
5948 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5949 s->scmac_tobe = s->maclist[i];
5953 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5954 for (i = 0; i < lenof(compressions) + 1; i++) {
5955 const struct ssh_compress *c =
5956 i == 0 ? s->preferred_comp : compressions[i - 1];
5957 if (in_commasep_string(c->name, str, len)) {
5960 } else if (in_commasep_string(c->delayed_name, str, len)) {
5961 if (s->userauth_succeeded) {
5965 s->pending_compression = TRUE; /* try this later */
5969 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5970 for (i = 0; i < lenof(compressions) + 1; i++) {
5971 const struct ssh_compress *c =
5972 i == 0 ? s->preferred_comp : compressions[i - 1];
5973 if (in_commasep_string(c->name, str, len)) {
5976 } else if (in_commasep_string(c->delayed_name, str, len)) {
5977 if (s->userauth_succeeded) {
5981 s->pending_compression = TRUE; /* try this later */
5985 if (s->pending_compression) {
5986 logevent("Server supports delayed compression; "
5987 "will try this later");
5989 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5990 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5991 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5993 ssh->exhash = ssh->kex->hash->init();
5994 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5995 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5996 hash_string(ssh->kex->hash, ssh->exhash,
5997 s->our_kexinit, s->our_kexinitlen);
5998 sfree(s->our_kexinit);
5999 /* Include the type byte in the hash of server's KEXINIT */
6000 hash_string(ssh->kex->hash, ssh->exhash,
6001 pktin->body - 1, pktin->length + 1);
6004 ssh_set_frozen(ssh, 1);
6005 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6007 ssh_dialog_callback, ssh);
6008 if (s->dlgret < 0) {
6012 bombout(("Unexpected data from server while"
6013 " waiting for user response"));
6016 } while (pktin || inlen > 0);
6017 s->dlgret = ssh->user_response;
6019 ssh_set_frozen(ssh, 0);
6020 if (s->dlgret == 0) {
6021 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6027 if (s->warn_cscipher) {
6028 ssh_set_frozen(ssh, 1);
6029 s->dlgret = askalg(ssh->frontend,
6030 "client-to-server cipher",
6031 s->cscipher_tobe->name,
6032 ssh_dialog_callback, ssh);
6033 if (s->dlgret < 0) {
6037 bombout(("Unexpected data from server while"
6038 " waiting for user response"));
6041 } while (pktin || inlen > 0);
6042 s->dlgret = ssh->user_response;
6044 ssh_set_frozen(ssh, 0);
6045 if (s->dlgret == 0) {
6046 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6052 if (s->warn_sccipher) {
6053 ssh_set_frozen(ssh, 1);
6054 s->dlgret = askalg(ssh->frontend,
6055 "server-to-client cipher",
6056 s->sccipher_tobe->name,
6057 ssh_dialog_callback, ssh);
6058 if (s->dlgret < 0) {
6062 bombout(("Unexpected data from server while"
6063 " waiting for user response"));
6066 } while (pktin || inlen > 0);
6067 s->dlgret = ssh->user_response;
6069 ssh_set_frozen(ssh, 0);
6070 if (s->dlgret == 0) {
6071 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6077 if (s->ignorepkt) /* first_kex_packet_follows */
6078 crWaitUntilV(pktin); /* Ignore packet */
6081 if (ssh->kex->main_type == KEXTYPE_DH) {
6083 * Work out the number of bits of key we will need from the
6084 * key exchange. We start with the maximum key length of
6090 csbits = s->cscipher_tobe->keylen;
6091 scbits = s->sccipher_tobe->keylen;
6092 s->nbits = (csbits > scbits ? csbits : scbits);
6094 /* The keys only have hlen-bit entropy, since they're based on
6095 * a hash. So cap the key size at hlen bits. */
6096 if (s->nbits > ssh->kex->hash->hlen * 8)
6097 s->nbits = ssh->kex->hash->hlen * 8;
6100 * If we're doing Diffie-Hellman group exchange, start by
6101 * requesting a group.
6103 if (!ssh->kex->pdata) {
6104 logevent("Doing Diffie-Hellman group exchange");
6105 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6107 * Work out how big a DH group we will need to allow that
6110 s->pbits = 512 << ((s->nbits - 1) / 64);
6111 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6112 ssh2_pkt_adduint32(s->pktout, s->pbits);
6113 ssh2_pkt_send_noqueue(ssh, s->pktout);
6115 crWaitUntilV(pktin);
6116 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6117 bombout(("expected key exchange group packet from server"));
6120 s->p = ssh2_pkt_getmp(pktin);
6121 s->g = ssh2_pkt_getmp(pktin);
6122 if (!s->p || !s->g) {
6123 bombout(("unable to read mp-ints from incoming group packet"));
6126 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6127 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6128 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6130 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6131 ssh->kex_ctx = dh_setup_group(ssh->kex);
6132 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6133 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6134 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6135 ssh->kex->groupname);
6138 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6139 ssh->kex->hash->text_name);
6141 * Now generate and send e for Diffie-Hellman.
6143 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6144 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6145 s->pktout = ssh2_pkt_init(s->kex_init_value);
6146 ssh2_pkt_addmp(s->pktout, s->e);
6147 ssh2_pkt_send_noqueue(ssh, s->pktout);
6149 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6150 crWaitUntilV(pktin);
6151 if (pktin->type != s->kex_reply_value) {
6152 bombout(("expected key exchange reply packet from server"));
6155 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6156 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6157 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6158 s->f = ssh2_pkt_getmp(pktin);
6160 bombout(("unable to parse key exchange reply packet"));
6163 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6165 s->K = dh_find_K(ssh->kex_ctx, s->f);
6167 /* We assume everything from now on will be quick, and it might
6168 * involve user interaction. */
6169 set_busy_status(ssh->frontend, BUSY_NOT);
6171 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6172 if (!ssh->kex->pdata) {
6173 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6174 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6175 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6177 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6178 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6180 dh_cleanup(ssh->kex_ctx);
6182 if (!ssh->kex->pdata) {
6187 logeventf(ssh, "Doing RSA key exchange with hash %s",
6188 ssh->kex->hash->text_name);
6189 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6191 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6194 crWaitUntilV(pktin);
6195 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6196 bombout(("expected RSA public key packet from server"));
6200 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6201 hash_string(ssh->kex->hash, ssh->exhash,
6202 s->hostkeydata, s->hostkeylen);
6203 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6207 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6208 s->rsakeydata = snewn(s->rsakeylen, char);
6209 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6212 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6214 sfree(s->rsakeydata);
6215 bombout(("unable to parse RSA public key from server"));
6219 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6222 * Next, set up a shared secret K, of precisely KLEN -
6223 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6224 * RSA key modulus and HLEN is the bit length of the hash
6228 int klen = ssh_rsakex_klen(s->rsakey);
6229 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6231 unsigned char *kstr1, *kstr2, *outstr;
6232 int kstr1len, kstr2len, outstrlen;
6234 s->K = bn_power_2(nbits - 1);
6236 for (i = 0; i < nbits; i++) {
6238 byte = random_byte();
6240 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6244 * Encode this as an mpint.
6246 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6247 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6248 PUT_32BIT(kstr2, kstr1len);
6249 memcpy(kstr2 + 4, kstr1, kstr1len);
6252 * Encrypt it with the given RSA key.
6254 outstrlen = (klen + 7) / 8;
6255 outstr = snewn(outstrlen, unsigned char);
6256 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6257 outstr, outstrlen, s->rsakey);
6260 * And send it off in a return packet.
6262 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6263 ssh2_pkt_addstring_start(s->pktout);
6264 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6265 ssh2_pkt_send_noqueue(ssh, s->pktout);
6267 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6274 ssh_rsakex_freekey(s->rsakey);
6276 crWaitUntilV(pktin);
6277 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6278 sfree(s->rsakeydata);
6279 bombout(("expected signature packet from server"));
6283 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6285 sfree(s->rsakeydata);
6288 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6289 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6290 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6292 ssh->kex_ctx = NULL;
6295 debug(("Exchange hash is:\n"));
6296 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6300 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6301 (char *)s->exchange_hash,
6302 ssh->kex->hash->hlen)) {
6303 bombout(("Server's host key did not match the signature supplied"));
6307 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6308 if (!s->got_session_id) {
6310 * Authenticate remote host: verify host key. (We've already
6311 * checked the signature of the exchange hash.)
6313 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6314 ssh_set_frozen(ssh, 1);
6315 s->dlgret = verify_ssh_host_key(ssh->frontend,
6316 ssh->savedhost, ssh->savedport,
6317 ssh->hostkey->keytype, s->keystr,
6319 ssh_dialog_callback, ssh);
6320 if (s->dlgret < 0) {
6324 bombout(("Unexpected data from server while waiting"
6325 " for user host key response"));
6328 } while (pktin || inlen > 0);
6329 s->dlgret = ssh->user_response;
6331 ssh_set_frozen(ssh, 0);
6332 if (s->dlgret == 0) {
6333 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6337 logevent("Host key fingerprint is:");
6338 logevent(s->fingerprint);
6339 sfree(s->fingerprint);
6341 * Save this host key, to check against the one presented in
6342 * subsequent rekeys.
6344 ssh->hostkey_str = s->keystr;
6347 * In a rekey, we never present an interactive host key
6348 * verification request to the user. Instead, we simply
6349 * enforce that the key we're seeing this time is identical to
6350 * the one we saw before.
6352 if (strcmp(ssh->hostkey_str, s->keystr)) {
6353 bombout(("Host key was different in repeat key exchange"));
6358 ssh->hostkey->freekey(s->hkey);
6361 * The exchange hash from the very first key exchange is also
6362 * the session id, used in session key construction and
6365 if (!s->got_session_id) {
6366 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6367 memcpy(ssh->v2_session_id, s->exchange_hash,
6368 sizeof(s->exchange_hash));
6369 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6370 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6371 s->got_session_id = TRUE;
6375 * Send SSH2_MSG_NEWKEYS.
6377 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6378 ssh2_pkt_send_noqueue(ssh, s->pktout);
6379 ssh->outgoing_data_size = 0; /* start counting from here */
6382 * We've sent client NEWKEYS, so create and initialise
6383 * client-to-server session keys.
6385 if (ssh->cs_cipher_ctx)
6386 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6387 ssh->cscipher = s->cscipher_tobe;
6388 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6390 if (ssh->cs_mac_ctx)
6391 ssh->csmac->free_context(ssh->cs_mac_ctx);
6392 ssh->csmac = s->csmac_tobe;
6393 ssh->cs_mac_ctx = ssh->csmac->make_context();
6395 if (ssh->cs_comp_ctx)
6396 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6397 ssh->cscomp = s->cscomp_tobe;
6398 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6401 * Set IVs on client-to-server keys. Here we use the exchange
6402 * hash from the _first_ key exchange.
6405 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6406 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6407 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6408 assert((ssh->cscipher->keylen+7) / 8 <=
6409 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6410 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6411 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6412 assert(ssh->cscipher->blksize <=
6413 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6414 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6415 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6416 assert(ssh->csmac->len <=
6417 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6418 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6419 smemclr(keyspace, sizeof(keyspace));
6422 logeventf(ssh, "Initialised %.200s client->server encryption",
6423 ssh->cscipher->text_name);
6424 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6425 ssh->csmac->text_name);
6426 if (ssh->cscomp->text_name)
6427 logeventf(ssh, "Initialised %s compression",
6428 ssh->cscomp->text_name);
6431 * Now our end of the key exchange is complete, we can send all
6432 * our queued higher-layer packets.
6434 ssh->queueing = FALSE;
6435 ssh2_pkt_queuesend(ssh);
6438 * Expect SSH2_MSG_NEWKEYS from server.
6440 crWaitUntilV(pktin);
6441 if (pktin->type != SSH2_MSG_NEWKEYS) {
6442 bombout(("expected new-keys packet from server"));
6445 ssh->incoming_data_size = 0; /* start counting from here */
6448 * We've seen server NEWKEYS, so create and initialise
6449 * server-to-client session keys.
6451 if (ssh->sc_cipher_ctx)
6452 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6453 ssh->sccipher = s->sccipher_tobe;
6454 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6456 if (ssh->sc_mac_ctx)
6457 ssh->scmac->free_context(ssh->sc_mac_ctx);
6458 ssh->scmac = s->scmac_tobe;
6459 ssh->sc_mac_ctx = ssh->scmac->make_context();
6461 if (ssh->sc_comp_ctx)
6462 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6463 ssh->sccomp = s->sccomp_tobe;
6464 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6467 * Set IVs on server-to-client keys. Here we use the exchange
6468 * hash from the _first_ key exchange.
6471 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6472 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6473 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6474 assert((ssh->sccipher->keylen+7) / 8 <=
6475 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6476 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6477 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6478 assert(ssh->sccipher->blksize <=
6479 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6480 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6481 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6482 assert(ssh->scmac->len <=
6483 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6484 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6485 smemclr(keyspace, sizeof(keyspace));
6487 logeventf(ssh, "Initialised %.200s server->client encryption",
6488 ssh->sccipher->text_name);
6489 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6490 ssh->scmac->text_name);
6491 if (ssh->sccomp->text_name)
6492 logeventf(ssh, "Initialised %s decompression",
6493 ssh->sccomp->text_name);
6496 * Free shared secret.
6501 * Key exchange is over. Loop straight back round if we have a
6502 * deferred rekey reason.
6504 if (ssh->deferred_rekey_reason) {
6505 logevent(ssh->deferred_rekey_reason);
6507 ssh->deferred_rekey_reason = NULL;
6508 goto begin_key_exchange;
6512 * Otherwise, schedule a timer for our next rekey.
6514 ssh->kex_in_progress = FALSE;
6515 ssh->last_rekey = GETTICKCOUNT();
6516 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6517 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6521 * Now we're encrypting. Begin returning 1 to the protocol main
6522 * function so that other things can run on top of the
6523 * transport. If we ever see a KEXINIT, we must go back to the
6526 * We _also_ go back to the start if we see pktin==NULL and
6527 * inlen negative, because this is a special signal meaning
6528 * `initiate client-driven rekey', and `in' contains a message
6529 * giving the reason for the rekey.
6531 * inlen==-1 means always initiate a rekey;
6532 * inlen==-2 means that userauth has completed successfully and
6533 * we should consider rekeying (for delayed compression).
6535 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6536 (!pktin && inlen < 0))) {
6538 if (!ssh->protocol_initial_phase_done) {
6539 ssh->protocol_initial_phase_done = TRUE;
6541 * Allow authconn to initialise itself.
6543 do_ssh2_authconn(ssh, NULL, 0, NULL);
6548 logevent("Server initiated key re-exchange");
6552 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6553 * delayed compression, if it's available.
6555 * draft-miller-secsh-compression-delayed-00 says that you
6556 * negotiate delayed compression in the first key exchange, and
6557 * both sides start compressing when the server has sent
6558 * USERAUTH_SUCCESS. This has a race condition -- the server
6559 * can't know when the client has seen it, and thus which incoming
6560 * packets it should treat as compressed.
6562 * Instead, we do the initial key exchange without offering the
6563 * delayed methods, but note if the server offers them; when we
6564 * get here, if a delayed method was available that was higher
6565 * on our list than what we got, we initiate a rekey in which we
6566 * _do_ list the delayed methods (and hopefully get it as a
6567 * result). Subsequent rekeys will do the same.
6569 assert(!s->userauth_succeeded); /* should only happen once */
6570 s->userauth_succeeded = TRUE;
6571 if (!s->pending_compression)
6572 /* Can't see any point rekeying. */
6573 goto wait_for_rekey; /* this is utterly horrid */
6574 /* else fall through to rekey... */
6575 s->pending_compression = FALSE;
6578 * Now we've decided to rekey.
6580 * Special case: if the server bug is set that doesn't
6581 * allow rekeying, we give a different log message and
6582 * continue waiting. (If such a server _initiates_ a rekey,
6583 * we process it anyway!)
6585 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6586 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6588 /* Reset the counters, so that at least this message doesn't
6589 * hit the event log _too_ often. */
6590 ssh->outgoing_data_size = 0;
6591 ssh->incoming_data_size = 0;
6592 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6594 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6597 goto wait_for_rekey; /* this is still utterly horrid */
6599 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6602 goto begin_key_exchange;
6608 * Add data to an SSH-2 channel output buffer.
6610 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6613 bufchain_add(&c->v.v2.outbuffer, buf, len);
6617 * Attempt to send data on an SSH-2 channel.
6619 static int ssh2_try_send(struct ssh_channel *c)
6622 struct Packet *pktout;
6625 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6628 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6629 if ((unsigned)len > c->v.v2.remwindow)
6630 len = c->v.v2.remwindow;
6631 if ((unsigned)len > c->v.v2.remmaxpkt)
6632 len = c->v.v2.remmaxpkt;
6633 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6634 ssh2_pkt_adduint32(pktout, c->remoteid);
6635 ssh2_pkt_addstring_start(pktout);
6636 ssh2_pkt_addstring_data(pktout, data, len);
6637 ssh2_pkt_send(ssh, pktout);
6638 bufchain_consume(&c->v.v2.outbuffer, len);
6639 c->v.v2.remwindow -= len;
6643 * After having sent as much data as we can, return the amount
6646 ret = bufchain_size(&c->v.v2.outbuffer);
6649 * And if there's no data pending but we need to send an EOF, send
6652 if (!ret && c->pending_eof)
6653 ssh_channel_try_eof(c);
6658 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6661 if (c->closes & CLOSES_SENT_EOF)
6662 return; /* don't send on channels we've EOFed */
6663 bufsize = ssh2_try_send(c);
6666 case CHAN_MAINSESSION:
6667 /* stdin need not receive an unthrottle
6668 * notification since it will be polled */
6671 x11_unthrottle(c->u.x11.xconn);
6674 /* agent sockets are request/response and need no
6675 * buffer management */
6678 pfd_unthrottle(c->u.pfd.pf);
6685 * Set up most of a new ssh_channel for SSH-2.
6687 static void ssh2_channel_init(struct ssh_channel *c)
6690 c->localid = alloc_channel_id(ssh);
6692 c->pending_eof = FALSE;
6693 c->throttling_conn = FALSE;
6694 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6695 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6696 c->v.v2.chanreq_head = NULL;
6697 c->v.v2.throttle_state = UNTHROTTLED;
6698 bufchain_init(&c->v.v2.outbuffer);
6702 * Construct the common parts of a CHANNEL_OPEN.
6704 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6706 struct Packet *pktout;
6708 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6709 ssh2_pkt_addstring(pktout, type);
6710 ssh2_pkt_adduint32(pktout, c->localid);
6711 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6712 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6717 * CHANNEL_FAILURE doesn't come with any indication of what message
6718 * caused it, so we have to keep track of the outstanding
6719 * CHANNEL_REQUESTs ourselves.
6721 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6722 cchandler_fn_t handler, void *ctx)
6724 struct outstanding_channel_request *ocr =
6725 snew(struct outstanding_channel_request);
6727 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6728 ocr->handler = handler;
6731 if (!c->v.v2.chanreq_head)
6732 c->v.v2.chanreq_head = ocr;
6734 c->v.v2.chanreq_tail->next = ocr;
6735 c->v.v2.chanreq_tail = ocr;
6739 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6740 * NULL then a reply will be requested and the handler will be called
6741 * when it arrives. The returned packet is ready to have any
6742 * request-specific data added and be sent. Note that if a handler is
6743 * provided, it's essential that the request actually be sent.
6745 * The handler will usually be passed the response packet in pktin.
6746 * If pktin is NULL, this means that no reply will ever be forthcoming
6747 * (e.g. because the entire connection is being destroyed) and the
6748 * handler should free any storage it's holding.
6750 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6751 cchandler_fn_t handler, void *ctx)
6753 struct Packet *pktout;
6755 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6756 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6757 ssh2_pkt_adduint32(pktout, c->remoteid);
6758 ssh2_pkt_addstring(pktout, type);
6759 ssh2_pkt_addbool(pktout, handler != NULL);
6760 if (handler != NULL)
6761 ssh2_queue_chanreq_handler(c, handler, ctx);
6766 * Potentially enlarge the window on an SSH-2 channel.
6768 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6770 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6775 * Never send WINDOW_ADJUST for a channel that the remote side has
6776 * already sent EOF on; there's no point, since it won't be
6777 * sending any more data anyway. Ditto if _we've_ already sent
6780 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6784 * If the remote end has a habit of ignoring maxpkt, limit the
6785 * window so that it has no choice (assuming it doesn't ignore the
6788 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6789 newwin = OUR_V2_MAXPKT;
6792 * Only send a WINDOW_ADJUST if there's significantly more window
6793 * available than the other end thinks there is. This saves us
6794 * sending a WINDOW_ADJUST for every character in a shell session.
6796 * "Significant" is arbitrarily defined as half the window size.
6798 if (newwin / 2 >= c->v.v2.locwindow) {
6799 struct Packet *pktout;
6803 * In order to keep track of how much window the client
6804 * actually has available, we'd like it to acknowledge each
6805 * WINDOW_ADJUST. We can't do that directly, so we accompany
6806 * it with a CHANNEL_REQUEST that has to be acknowledged.
6808 * This is only necessary if we're opening the window wide.
6809 * If we're not, then throughput is being constrained by
6810 * something other than the maximum window size anyway.
6812 if (newwin == c->v.v2.locmaxwin &&
6813 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6814 up = snew(unsigned);
6815 *up = newwin - c->v.v2.locwindow;
6816 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6817 ssh2_handle_winadj_response, up);
6818 ssh2_pkt_send(ssh, pktout);
6820 if (c->v.v2.throttle_state != UNTHROTTLED)
6821 c->v.v2.throttle_state = UNTHROTTLING;
6823 /* Pretend the WINDOW_ADJUST was acked immediately. */
6824 c->v.v2.remlocwin = newwin;
6825 c->v.v2.throttle_state = THROTTLED;
6827 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6828 ssh2_pkt_adduint32(pktout, c->remoteid);
6829 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6830 ssh2_pkt_send(ssh, pktout);
6831 c->v.v2.locwindow = newwin;
6836 * Find the channel associated with a message. If there's no channel,
6837 * or it's not properly open, make a noise about it and return NULL.
6839 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6841 unsigned localid = ssh_pkt_getuint32(pktin);
6842 struct ssh_channel *c;
6844 c = find234(ssh->channels, &localid, ssh_channelfind);
6846 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6847 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6848 char *buf = dupprintf("Received %s for %s channel %u",
6849 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6851 c ? "half-open" : "nonexistent", localid);
6852 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6859 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6860 struct Packet *pktin, void *ctx)
6862 unsigned *sizep = ctx;
6865 * Winadj responses should always be failures. However, at least
6866 * one server ("boks_sshd") is known to return SUCCESS for channel
6867 * requests it's never heard of, such as "winadj@putty". Raised
6868 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6869 * life, we don't worry about what kind of response we got.
6872 c->v.v2.remlocwin += *sizep;
6875 * winadj messages are only sent when the window is fully open, so
6876 * if we get an ack of one, we know any pending unthrottle is
6879 if (c->v.v2.throttle_state == UNTHROTTLING)
6880 c->v.v2.throttle_state = UNTHROTTLED;
6883 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6885 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6886 struct outstanding_channel_request *ocr;
6889 ocr = c->v.v2.chanreq_head;
6891 ssh2_msg_unexpected(ssh, pktin);
6894 ocr->handler(c, pktin, ocr->ctx);
6895 c->v.v2.chanreq_head = ocr->next;
6898 * We may now initiate channel-closing procedures, if that
6899 * CHANNEL_REQUEST was the last thing outstanding before we send
6902 ssh2_channel_check_close(c);
6905 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6907 struct ssh_channel *c;
6908 c = ssh2_channel_msg(ssh, pktin);
6911 if (!(c->closes & CLOSES_SENT_EOF)) {
6912 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6913 ssh2_try_send_and_unthrottle(ssh, c);
6917 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6921 struct ssh_channel *c;
6922 c = ssh2_channel_msg(ssh, pktin);
6925 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6926 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6927 return; /* extended but not stderr */
6928 ssh_pkt_getstring(pktin, &data, &length);
6931 c->v.v2.locwindow -= length;
6932 c->v.v2.remlocwin -= length;
6934 case CHAN_MAINSESSION:
6936 from_backend(ssh->frontend, pktin->type ==
6937 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6941 bufsize = x11_send(c->u.x11.xconn, data, length);
6944 bufsize = pfd_send(c->u.pfd.pf, data, length);
6947 while (length > 0) {
6948 if (c->u.a.lensofar < 4) {
6949 unsigned int l = min(4 - c->u.a.lensofar,
6951 memcpy(c->u.a.msglen + c->u.a.lensofar,
6955 c->u.a.lensofar += l;
6957 if (c->u.a.lensofar == 4) {
6959 4 + GET_32BIT(c->u.a.msglen);
6960 c->u.a.message = snewn(c->u.a.totallen,
6962 memcpy(c->u.a.message, c->u.a.msglen, 4);
6964 if (c->u.a.lensofar >= 4 && length > 0) {
6966 min(c->u.a.totallen - c->u.a.lensofar,
6968 memcpy(c->u.a.message + c->u.a.lensofar,
6972 c->u.a.lensofar += l;
6974 if (c->u.a.lensofar == c->u.a.totallen) {
6977 c->u.a.outstanding_requests++;
6978 if (agent_query(c->u.a.message,
6981 ssh_agentf_callback, c))
6982 ssh_agentf_callback(c, reply, replylen);
6983 sfree(c->u.a.message);
6984 c->u.a.message = NULL;
6985 c->u.a.lensofar = 0;
6992 * If it looks like the remote end hit the end of its window,
6993 * and we didn't want it to do that, think about using a
6996 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6997 c->v.v2.locmaxwin < 0x40000000)
6998 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7000 * If we are not buffering too much data,
7001 * enlarge the window again at the remote side.
7002 * If we are buffering too much, we may still
7003 * need to adjust the window if the server's
7006 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7007 c->v.v2.locmaxwin - bufsize : 0);
7009 * If we're either buffering way too much data, or if we're
7010 * buffering anything at all and we're in "simple" mode,
7011 * throttle the whole channel.
7013 if ((bufsize > c->v.v2.locmaxwin ||
7014 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
7015 !c->throttling_conn) {
7016 c->throttling_conn = 1;
7017 ssh_throttle_conn(ssh, +1);
7022 static void ssh_channel_destroy(struct ssh_channel *c)
7027 case CHAN_MAINSESSION:
7028 ssh->mainchan = NULL;
7029 update_specials_menu(ssh->frontend);
7032 if (c->u.x11.xconn != NULL)
7033 x11_close(c->u.x11.xconn);
7034 logevent("Forwarded X11 connection terminated");
7037 sfree(c->u.a.message);
7040 if (c->u.pfd.pf != NULL)
7041 pfd_close(c->u.pfd.pf);
7042 logevent("Forwarded port closed");
7046 del234(ssh->channels, c);
7047 if (ssh->version == 2) {
7048 bufchain_clear(&c->v.v2.outbuffer);
7049 assert(c->v.v2.chanreq_head == NULL);
7054 * See if that was the last channel left open.
7055 * (This is only our termination condition if we're
7056 * not running in -N mode.)
7058 if (ssh->version == 2 &&
7059 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7060 count234(ssh->channels) == 0) {
7062 * We used to send SSH_MSG_DISCONNECT here,
7063 * because I'd believed that _every_ conforming
7064 * SSH-2 connection had to end with a disconnect
7065 * being sent by at least one side; apparently
7066 * I was wrong and it's perfectly OK to
7067 * unceremoniously slam the connection shut
7068 * when you're done, and indeed OpenSSH feels
7069 * this is more polite than sending a
7070 * DISCONNECT. So now we don't.
7072 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7076 static void ssh2_channel_check_close(struct ssh_channel *c)
7079 struct Packet *pktout;
7083 * If we've sent out our own CHANNEL_OPEN but not yet seen
7084 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7085 * it's too early to be sending close messages of any kind.
7090 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7091 c->type == CHAN_ZOMBIE) &&
7092 !c->v.v2.chanreq_head &&
7093 !(c->closes & CLOSES_SENT_CLOSE)) {
7095 * We have both sent and received EOF (or the channel is a
7096 * zombie), and we have no outstanding channel requests, which
7097 * means the channel is in final wind-up. But we haven't sent
7098 * CLOSE, so let's do so now.
7100 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7101 ssh2_pkt_adduint32(pktout, c->remoteid);
7102 ssh2_pkt_send(ssh, pktout);
7103 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7106 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7107 assert(c->v.v2.chanreq_head == NULL);
7109 * We have both sent and received CLOSE, which means we're
7110 * completely done with the channel.
7112 ssh_channel_destroy(c);
7116 static void ssh2_channel_got_eof(struct ssh_channel *c)
7118 if (c->closes & CLOSES_RCVD_EOF)
7119 return; /* already seen EOF */
7120 c->closes |= CLOSES_RCVD_EOF;
7122 if (c->type == CHAN_X11) {
7123 x11_send_eof(c->u.x11.xconn);
7124 } else if (c->type == CHAN_AGENT) {
7125 if (c->u.a.outstanding_requests == 0) {
7126 /* Manufacture an outgoing EOF in response to the incoming one. */
7127 sshfwd_write_eof(c);
7129 } else if (c->type == CHAN_SOCKDATA) {
7130 pfd_send_eof(c->u.pfd.pf);
7131 } else if (c->type == CHAN_MAINSESSION) {
7134 if (!ssh->sent_console_eof &&
7135 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7137 * Either from_backend_eof told us that the front end
7138 * wants us to close the outgoing side of the connection
7139 * as soon as we see EOF from the far end, or else we've
7140 * unilaterally decided to do that because we've allocated
7141 * a remote pty and hence EOF isn't a particularly
7142 * meaningful concept.
7144 sshfwd_write_eof(c);
7146 ssh->sent_console_eof = TRUE;
7149 ssh2_channel_check_close(c);
7152 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7154 struct ssh_channel *c;
7156 c = ssh2_channel_msg(ssh, pktin);
7159 ssh2_channel_got_eof(c);
7162 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7164 struct ssh_channel *c;
7166 c = ssh2_channel_msg(ssh, pktin);
7171 * When we receive CLOSE on a channel, we assume it comes with an
7172 * implied EOF if we haven't seen EOF yet.
7174 ssh2_channel_got_eof(c);
7177 * And we also send an outgoing EOF, if we haven't already, on the
7178 * assumption that CLOSE is a pretty forceful announcement that
7179 * the remote side is doing away with the entire channel. (If it
7180 * had wanted to send us EOF and continue receiving data from us,
7181 * it would have just sent CHANNEL_EOF.)
7183 if (!(c->closes & CLOSES_SENT_EOF)) {
7185 * Make sure we don't read any more from whatever our local
7186 * data source is for this channel.
7189 case CHAN_MAINSESSION:
7190 ssh->send_ok = 0; /* stop trying to read from stdin */
7193 x11_override_throttle(c->u.x11.xconn, 1);
7196 pfd_override_throttle(c->u.pfd.pf, 1);
7201 * Abandon any buffered data we still wanted to send to this
7202 * channel. Receiving a CHANNEL_CLOSE is an indication that
7203 * the server really wants to get on and _destroy_ this
7204 * channel, and it isn't going to send us any further
7205 * WINDOW_ADJUSTs to permit us to send pending stuff.
7207 bufchain_clear(&c->v.v2.outbuffer);
7210 * Send outgoing EOF.
7212 sshfwd_write_eof(c);
7216 * Now process the actual close.
7218 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7219 c->closes |= CLOSES_RCVD_CLOSE;
7220 ssh2_channel_check_close(c);
7224 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7226 struct ssh_channel *c;
7228 c = ssh2_channel_msg(ssh, pktin);
7231 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7232 c->remoteid = ssh_pkt_getuint32(pktin);
7233 c->halfopen = FALSE;
7234 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7235 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7237 if (c->type == CHAN_SOCKDATA_DORMANT) {
7238 c->type = CHAN_SOCKDATA;
7240 pfd_confirm(c->u.pfd.pf);
7241 } else if (c->type == CHAN_ZOMBIE) {
7243 * This case can occur if a local socket error occurred
7244 * between us sending out CHANNEL_OPEN and receiving
7245 * OPEN_CONFIRMATION. In this case, all we can do is
7246 * immediately initiate close proceedings now that we know the
7247 * server's id to put in the close message.
7249 ssh2_channel_check_close(c);
7252 * We never expect to receive OPEN_CONFIRMATION for any
7253 * *other* channel type (since only local-to-remote port
7254 * forwardings cause us to send CHANNEL_OPEN after the main
7255 * channel is live - all other auxiliary channel types are
7256 * initiated from the server end). It's safe to enforce this
7257 * by assertion rather than by ssh_disconnect, because the
7258 * real point is that we never constructed a half-open channel
7259 * structure in the first place with any type other than the
7262 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7266 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7269 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7271 static const char *const reasons[] = {
7272 "<unknown reason code>",
7273 "Administratively prohibited",
7275 "Unknown channel type",
7276 "Resource shortage",
7278 unsigned reason_code;
7279 char *reason_string;
7281 struct ssh_channel *c;
7283 c = ssh2_channel_msg(ssh, pktin);
7286 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7288 if (c->type == CHAN_SOCKDATA_DORMANT) {
7289 reason_code = ssh_pkt_getuint32(pktin);
7290 if (reason_code >= lenof(reasons))
7291 reason_code = 0; /* ensure reasons[reason_code] in range */
7292 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7293 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7294 reasons[reason_code], reason_length, reason_string);
7296 pfd_close(c->u.pfd.pf);
7297 } else if (c->type == CHAN_ZOMBIE) {
7299 * This case can occur if a local socket error occurred
7300 * between us sending out CHANNEL_OPEN and receiving
7301 * OPEN_FAILURE. In this case, we need do nothing except allow
7302 * the code below to throw the half-open channel away.
7306 * We never expect to receive OPEN_FAILURE for any *other*
7307 * channel type (since only local-to-remote port forwardings
7308 * cause us to send CHANNEL_OPEN after the main channel is
7309 * live - all other auxiliary channel types are initiated from
7310 * the server end). It's safe to enforce this by assertion
7311 * rather than by ssh_disconnect, because the real point is
7312 * that we never constructed a half-open channel structure in
7313 * the first place with any type other than the above.
7315 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7318 del234(ssh->channels, c);
7322 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7325 int typelen, want_reply;
7326 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7327 struct ssh_channel *c;
7328 struct Packet *pktout;
7330 c = ssh2_channel_msg(ssh, pktin);
7333 ssh_pkt_getstring(pktin, &type, &typelen);
7334 want_reply = ssh2_pkt_getbool(pktin);
7337 * Having got the channel number, we now look at
7338 * the request type string to see if it's something
7341 if (c == ssh->mainchan) {
7343 * We recognise "exit-status" and "exit-signal" on
7344 * the primary channel.
7346 if (typelen == 11 &&
7347 !memcmp(type, "exit-status", 11)) {
7349 ssh->exitcode = ssh_pkt_getuint32(pktin);
7350 logeventf(ssh, "Server sent command exit status %d",
7352 reply = SSH2_MSG_CHANNEL_SUCCESS;
7354 } else if (typelen == 11 &&
7355 !memcmp(type, "exit-signal", 11)) {
7357 int is_plausible = TRUE, is_int = FALSE;
7358 char *fmt_sig = "", *fmt_msg = "";
7360 int msglen = 0, core = FALSE;
7361 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7362 * provide an `int' for the signal, despite its
7363 * having been a `string' in the drafts of RFC 4254 since at
7364 * least 2001. (Fixed in session.c 1.147.) Try to
7365 * infer which we can safely parse it as. */
7367 unsigned char *p = pktin->body +
7369 long len = pktin->length - pktin->savedpos;
7370 unsigned long num = GET_32BIT(p); /* what is it? */
7371 /* If it's 0, it hardly matters; assume string */
7375 int maybe_int = FALSE, maybe_str = FALSE;
7376 #define CHECK_HYPOTHESIS(offset, result) \
7379 int q = toint(offset); \
7380 if (q >= 0 && q+4 <= len) { \
7381 q = toint(q + 4 + GET_32BIT(p+q)); \
7382 if (q >= 0 && q+4 <= len && \
7383 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7388 CHECK_HYPOTHESIS(4+1, maybe_int);
7389 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7390 #undef CHECK_HYPOTHESIS
7391 if (maybe_int && !maybe_str)
7393 else if (!maybe_int && maybe_str)
7396 /* Crikey. Either or neither. Panic. */
7397 is_plausible = FALSE;
7400 ssh->exitcode = 128; /* means `unknown signal' */
7403 /* Old non-standard OpenSSH. */
7404 int signum = ssh_pkt_getuint32(pktin);
7405 fmt_sig = dupprintf(" %d", signum);
7406 ssh->exitcode = 128 + signum;
7408 /* As per RFC 4254. */
7411 ssh_pkt_getstring(pktin, &sig, &siglen);
7412 /* Signal name isn't supposed to be blank, but
7413 * let's cope gracefully if it is. */
7415 fmt_sig = dupprintf(" \"%.*s\"",
7420 * Really hideous method of translating the
7421 * signal description back into a locally
7422 * meaningful number.
7427 #define TRANSLATE_SIGNAL(s) \
7428 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7429 ssh->exitcode = 128 + SIG ## s
7431 TRANSLATE_SIGNAL(ABRT);
7434 TRANSLATE_SIGNAL(ALRM);
7437 TRANSLATE_SIGNAL(FPE);
7440 TRANSLATE_SIGNAL(HUP);
7443 TRANSLATE_SIGNAL(ILL);
7446 TRANSLATE_SIGNAL(INT);
7449 TRANSLATE_SIGNAL(KILL);
7452 TRANSLATE_SIGNAL(PIPE);
7455 TRANSLATE_SIGNAL(QUIT);
7458 TRANSLATE_SIGNAL(SEGV);
7461 TRANSLATE_SIGNAL(TERM);
7464 TRANSLATE_SIGNAL(USR1);
7467 TRANSLATE_SIGNAL(USR2);
7469 #undef TRANSLATE_SIGNAL
7471 ssh->exitcode = 128;
7473 core = ssh2_pkt_getbool(pktin);
7474 ssh_pkt_getstring(pktin, &msg, &msglen);
7476 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7478 /* ignore lang tag */
7479 } /* else don't attempt to parse */
7480 logeventf(ssh, "Server exited on signal%s%s%s",
7481 fmt_sig, core ? " (core dumped)" : "",
7483 if (*fmt_sig) sfree(fmt_sig);
7484 if (*fmt_msg) sfree(fmt_msg);
7485 reply = SSH2_MSG_CHANNEL_SUCCESS;
7490 * This is a channel request we don't know
7491 * about, so we now either ignore the request
7492 * or respond with CHANNEL_FAILURE, depending
7495 reply = SSH2_MSG_CHANNEL_FAILURE;
7498 pktout = ssh2_pkt_init(reply);
7499 ssh2_pkt_adduint32(pktout, c->remoteid);
7500 ssh2_pkt_send(ssh, pktout);
7504 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7507 int typelen, want_reply;
7508 struct Packet *pktout;
7510 ssh_pkt_getstring(pktin, &type, &typelen);
7511 want_reply = ssh2_pkt_getbool(pktin);
7514 * We currently don't support any global requests
7515 * at all, so we either ignore the request or
7516 * respond with REQUEST_FAILURE, depending on
7520 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7521 ssh2_pkt_send(ssh, pktout);
7525 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7533 struct ssh_channel *c;
7534 unsigned remid, winsize, pktsize;
7535 struct Packet *pktout;
7537 ssh_pkt_getstring(pktin, &type, &typelen);
7538 c = snew(struct ssh_channel);
7541 remid = ssh_pkt_getuint32(pktin);
7542 winsize = ssh_pkt_getuint32(pktin);
7543 pktsize = ssh_pkt_getuint32(pktin);
7545 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7549 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7550 addrstr = snewn(peeraddrlen+1, char);
7551 memcpy(addrstr, peeraddr, peeraddrlen);
7552 addrstr[peeraddrlen] = '\0';
7553 peerport = ssh_pkt_getuint32(pktin);
7555 logeventf(ssh, "Received X11 connect request from %s:%d",
7558 if (!ssh->X11_fwd_enabled)
7559 error = "X11 forwarding is not enabled";
7560 else if ((x11err = x11_init(&c->u.x11.xconn, ssh->x11disp, c,
7561 addrstr, peerport, ssh->conf)) != NULL) {
7562 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7564 error = "Unable to open an X11 connection";
7566 logevent("Opening X11 forward connection succeeded");
7571 } else if (typelen == 15 &&
7572 !memcmp(type, "forwarded-tcpip", 15)) {
7573 struct ssh_rportfwd pf, *realpf;
7576 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
7577 pf.shost = dupprintf("%.*s", shostlen, shost);
7578 pf.sport = ssh_pkt_getuint32(pktin);
7579 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7580 peerport = ssh_pkt_getuint32(pktin);
7581 realpf = find234(ssh->rportfwds, &pf, NULL);
7582 logeventf(ssh, "Received remote port %s:%d open request "
7583 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
7586 if (realpf == NULL) {
7587 error = "Remote port is not recognised";
7589 char *err = pfd_connect(&c->u.pfd.pf,
7593 realpf->pfrec->addressfamily);
7594 logeventf(ssh, "Attempting to forward remote port to "
7595 "%s:%d", realpf->dhost, realpf->dport);
7597 logeventf(ssh, "Port open failed: %s", err);
7599 error = "Port open failed";
7601 logevent("Forwarded port opened successfully");
7602 c->type = CHAN_SOCKDATA;
7605 } else if (typelen == 22 &&
7606 !memcmp(type, "auth-agent@openssh.com", 22)) {
7607 if (!ssh->agentfwd_enabled)
7608 error = "Agent forwarding is not enabled";
7610 c->type = CHAN_AGENT; /* identify channel type */
7611 c->u.a.lensofar = 0;
7612 c->u.a.message = NULL;
7613 c->u.a.outstanding_requests = 0;
7616 error = "Unsupported channel type requested";
7619 c->remoteid = remid;
7620 c->halfopen = FALSE;
7622 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7623 ssh2_pkt_adduint32(pktout, c->remoteid);
7624 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7625 ssh2_pkt_addstring(pktout, error);
7626 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7627 ssh2_pkt_send(ssh, pktout);
7628 logeventf(ssh, "Rejected channel open: %s", error);
7631 ssh2_channel_init(c);
7632 c->v.v2.remwindow = winsize;
7633 c->v.v2.remmaxpkt = pktsize;
7634 add234(ssh->channels, c);
7635 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7636 ssh2_pkt_adduint32(pktout, c->remoteid);
7637 ssh2_pkt_adduint32(pktout, c->localid);
7638 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7639 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7640 ssh2_pkt_send(ssh, pktout);
7645 * Buffer banner messages for later display at some convenient point,
7646 * if we're going to display them.
7648 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7650 /* Arbitrary limit to prevent unbounded inflation of buffer */
7651 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7652 bufchain_size(&ssh->banner) <= 131072) {
7653 char *banner = NULL;
7655 ssh_pkt_getstring(pktin, &banner, &size);
7657 bufchain_add(&ssh->banner, banner, size);
7661 /* Helper function to deal with sending tty modes for "pty-req" */
7662 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7664 struct Packet *pktout = (struct Packet *)data;
7666 unsigned int arg = 0;
7667 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7668 if (i == lenof(ssh_ttymodes)) return;
7669 switch (ssh_ttymodes[i].type) {
7671 arg = ssh_tty_parse_specchar(val);
7674 arg = ssh_tty_parse_boolean(val);
7677 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7678 ssh2_pkt_adduint32(pktout, arg);
7681 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7684 struct ssh2_setup_x11_state {
7688 struct Packet *pktout;
7689 crStateP(ssh2_setup_x11_state, ctx);
7693 logevent("Requesting X11 forwarding");
7694 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7696 ssh2_pkt_addbool(pktout, 0); /* many connections */
7697 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7698 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7699 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7700 ssh2_pkt_send(ssh, pktout);
7702 /* Wait to be called back with either a response packet, or NULL
7703 * meaning clean up and free our data */
7707 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7708 logevent("X11 forwarding enabled");
7709 ssh->X11_fwd_enabled = TRUE;
7711 logevent("X11 forwarding refused");
7717 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7720 struct ssh2_setup_agent_state {
7724 struct Packet *pktout;
7725 crStateP(ssh2_setup_agent_state, ctx);
7729 logevent("Requesting OpenSSH-style agent forwarding");
7730 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7731 ssh2_setup_agent, s);
7732 ssh2_pkt_send(ssh, pktout);
7734 /* Wait to be called back with either a response packet, or NULL
7735 * meaning clean up and free our data */
7739 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7740 logevent("Agent forwarding enabled");
7741 ssh->agentfwd_enabled = TRUE;
7743 logevent("Agent forwarding refused");
7749 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7752 struct ssh2_setup_pty_state {
7756 struct Packet *pktout;
7757 crStateP(ssh2_setup_pty_state, ctx);
7761 /* Unpick the terminal-speed string. */
7762 /* XXX perhaps we should allow no speeds to be sent. */
7763 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7764 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7765 /* Build the pty request. */
7766 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7768 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7769 ssh2_pkt_adduint32(pktout, ssh->term_width);
7770 ssh2_pkt_adduint32(pktout, ssh->term_height);
7771 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7772 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7773 ssh2_pkt_addstring_start(pktout);
7774 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7775 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7776 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7777 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7778 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7779 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7780 ssh2_pkt_send(ssh, pktout);
7781 ssh->state = SSH_STATE_INTERMED;
7783 /* Wait to be called back with either a response packet, or NULL
7784 * meaning clean up and free our data */
7788 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7789 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7790 ssh->ospeed, ssh->ispeed);
7791 ssh->got_pty = TRUE;
7793 c_write_str(ssh, "Server refused to allocate pty\r\n");
7794 ssh->editing = ssh->echoing = 1;
7801 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7804 struct ssh2_setup_env_state {
7806 int num_env, env_left, env_ok;
7809 struct Packet *pktout;
7810 crStateP(ssh2_setup_env_state, ctx);
7815 * Send environment variables.
7817 * Simplest thing here is to send all the requests at once, and
7818 * then wait for a whole bunch of successes or failures.
7824 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7826 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7827 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7828 ssh2_pkt_addstring(pktout, key);
7829 ssh2_pkt_addstring(pktout, val);
7830 ssh2_pkt_send(ssh, pktout);
7835 logeventf(ssh, "Sent %d environment variables", s->num_env);
7840 s->env_left = s->num_env;
7842 while (s->env_left > 0) {
7843 /* Wait to be called back with either a response packet,
7844 * or NULL meaning clean up and free our data */
7846 if (!pktin) goto out;
7847 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7852 if (s->env_ok == s->num_env) {
7853 logevent("All environment variables successfully set");
7854 } else if (s->env_ok == 0) {
7855 logevent("All environment variables refused");
7856 c_write_str(ssh, "Server refused to set environment variables\r\n");
7858 logeventf(ssh, "%d environment variables refused",
7859 s->num_env - s->env_ok);
7860 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7868 * Handle the SSH-2 userauth and connection layers.
7870 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7872 do_ssh2_authconn(ssh, NULL, 0, pktin);
7875 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7878 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7881 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7882 struct Packet *pktin)
7884 struct do_ssh2_authconn_state {
7888 AUTH_TYPE_PUBLICKEY,
7889 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7890 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7892 AUTH_TYPE_GSSAPI, /* always QUIET */
7893 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7894 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7896 int done_service_req;
7897 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7898 int tried_pubkey_config, done_agent;
7903 int kbd_inter_refused;
7904 int we_are_in, userauth_success;
7905 prompts_t *cur_prompt;
7910 void *publickey_blob;
7911 int publickey_bloblen;
7912 int publickey_encrypted;
7913 char *publickey_algorithm;
7914 char *publickey_comment;
7915 unsigned char agent_request[5], *agent_response, *agentp;
7916 int agent_responselen;
7917 unsigned char *pkblob_in_agent;
7919 char *pkblob, *alg, *commentp;
7920 int pklen, alglen, commentlen;
7921 int siglen, retlen, len;
7922 char *q, *agentreq, *ret;
7924 struct Packet *pktout;
7927 struct ssh_gss_library *gsslib;
7928 Ssh_gss_ctx gss_ctx;
7929 Ssh_gss_buf gss_buf;
7930 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7931 Ssh_gss_name gss_srv_name;
7932 Ssh_gss_stat gss_stat;
7935 crState(do_ssh2_authconn_state);
7939 /* Register as a handler for all the messages this coroutine handles. */
7940 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7941 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7942 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7943 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7944 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7945 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7946 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7947 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7948 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7949 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7950 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7951 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7952 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7953 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7954 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7955 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7956 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7957 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7958 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7959 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7961 s->done_service_req = FALSE;
7962 s->we_are_in = s->userauth_success = FALSE;
7964 s->tried_gssapi = FALSE;
7967 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7969 * Request userauth protocol, and await a response to it.
7971 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7972 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7973 ssh2_pkt_send(ssh, s->pktout);
7974 crWaitUntilV(pktin);
7975 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7976 s->done_service_req = TRUE;
7978 if (!s->done_service_req) {
7980 * Request connection protocol directly, without authentication.
7982 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7983 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7984 ssh2_pkt_send(ssh, s->pktout);
7985 crWaitUntilV(pktin);
7986 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7987 s->we_are_in = TRUE; /* no auth required */
7989 bombout(("Server refused service request"));
7994 /* Arrange to be able to deal with any BANNERs that come in.
7995 * (We do this now as packets may come in during the next bit.) */
7996 bufchain_init(&ssh->banner);
7997 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7998 ssh2_msg_userauth_banner;
8001 * Misc one-time setup for authentication.
8003 s->publickey_blob = NULL;
8004 if (!s->we_are_in) {
8007 * Load the public half of any configured public key file
8010 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8011 if (!filename_is_null(s->keyfile)) {
8013 logeventf(ssh, "Reading private key file \"%.150s\"",
8014 filename_to_str(s->keyfile));
8015 keytype = key_type(s->keyfile);
8016 if (keytype == SSH_KEYTYPE_SSH2) {
8019 ssh2_userkey_loadpub(s->keyfile,
8020 &s->publickey_algorithm,
8021 &s->publickey_bloblen,
8022 &s->publickey_comment, &error);
8023 if (s->publickey_blob) {
8024 s->publickey_encrypted =
8025 ssh2_userkey_encrypted(s->keyfile, NULL);
8028 logeventf(ssh, "Unable to load private key (%s)",
8030 msgbuf = dupprintf("Unable to load private key file "
8031 "\"%.150s\" (%s)\r\n",
8032 filename_to_str(s->keyfile),
8034 c_write_str(ssh, msgbuf);
8039 logeventf(ssh, "Unable to use this key file (%s)",
8040 key_type_to_str(keytype));
8041 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8043 filename_to_str(s->keyfile),
8044 key_type_to_str(keytype));
8045 c_write_str(ssh, msgbuf);
8047 s->publickey_blob = NULL;
8052 * Find out about any keys Pageant has (but if there's a
8053 * public key configured, filter out all others).
8056 s->agent_response = NULL;
8057 s->pkblob_in_agent = NULL;
8058 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8062 logevent("Pageant is running. Requesting keys.");
8064 /* Request the keys held by the agent. */
8065 PUT_32BIT(s->agent_request, 1);
8066 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8067 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8068 ssh_agent_callback, ssh)) {
8072 bombout(("Unexpected data from server while"
8073 " waiting for agent response"));
8076 } while (pktin || inlen > 0);
8077 r = ssh->agent_response;
8078 s->agent_responselen = ssh->agent_response_len;
8080 s->agent_response = (unsigned char *) r;
8081 if (s->agent_response && s->agent_responselen >= 5 &&
8082 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8085 p = s->agent_response + 5;
8086 s->nkeys = toint(GET_32BIT(p));
8089 * Vet the Pageant response to ensure that the key
8090 * count and blob lengths make sense.
8093 logeventf(ssh, "Pageant response contained a negative"
8094 " key count %d", s->nkeys);
8096 goto done_agent_query;
8098 unsigned char *q = p + 4;
8099 int lenleft = s->agent_responselen - 5 - 4;
8101 for (keyi = 0; keyi < s->nkeys; keyi++) {
8102 int bloblen, commentlen;
8104 logeventf(ssh, "Pageant response was truncated");
8106 goto done_agent_query;
8108 bloblen = toint(GET_32BIT(q));
8109 if (bloblen < 0 || bloblen > lenleft) {
8110 logeventf(ssh, "Pageant response was truncated");
8112 goto done_agent_query;
8114 lenleft -= 4 + bloblen;
8116 commentlen = toint(GET_32BIT(q));
8117 if (commentlen < 0 || commentlen > lenleft) {
8118 logeventf(ssh, "Pageant response was truncated");
8120 goto done_agent_query;
8122 lenleft -= 4 + commentlen;
8123 q += 4 + commentlen;
8128 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8129 if (s->publickey_blob) {
8130 /* See if configured key is in agent. */
8131 for (keyi = 0; keyi < s->nkeys; keyi++) {
8132 s->pklen = toint(GET_32BIT(p));
8133 if (s->pklen == s->publickey_bloblen &&
8134 !memcmp(p+4, s->publickey_blob,
8135 s->publickey_bloblen)) {
8136 logeventf(ssh, "Pageant key #%d matches "
8137 "configured key file", keyi);
8139 s->pkblob_in_agent = p;
8143 p += toint(GET_32BIT(p)) + 4; /* comment */
8145 if (!s->pkblob_in_agent) {
8146 logevent("Configured key file not in Pageant");
8151 logevent("Failed to get reply from Pageant");
8159 * We repeat this whole loop, including the username prompt,
8160 * until we manage a successful authentication. If the user
8161 * types the wrong _password_, they can be sent back to the
8162 * beginning to try another username, if this is configured on.
8163 * (If they specify a username in the config, they are never
8164 * asked, even if they do give a wrong password.)
8166 * I think this best serves the needs of
8168 * - the people who have no configuration, no keys, and just
8169 * want to try repeated (username,password) pairs until they
8170 * type both correctly
8172 * - people who have keys and configuration but occasionally
8173 * need to fall back to passwords
8175 * - people with a key held in Pageant, who might not have
8176 * logged in to a particular machine before; so they want to
8177 * type a username, and then _either_ their key will be
8178 * accepted, _or_ they will type a password. If they mistype
8179 * the username they will want to be able to get back and
8182 s->got_username = FALSE;
8183 while (!s->we_are_in) {
8187 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8189 * We got a username last time round this loop, and
8190 * with change_username turned off we don't try to get
8193 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8194 int ret; /* need not be kept over crReturn */
8195 s->cur_prompt = new_prompts(ssh->frontend);
8196 s->cur_prompt->to_server = TRUE;
8197 s->cur_prompt->name = dupstr("SSH login name");
8198 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8199 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8202 crWaitUntilV(!pktin);
8203 ret = get_userpass_input(s->cur_prompt, in, inlen);
8208 * get_userpass_input() failed to get a username.
8211 free_prompts(s->cur_prompt);
8212 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8215 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8216 free_prompts(s->cur_prompt);
8219 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8220 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8221 c_write_str(ssh, stuff);
8225 s->got_username = TRUE;
8228 * Send an authentication request using method "none": (a)
8229 * just in case it succeeds, and (b) so that we know what
8230 * authentication methods we can usefully try next.
8232 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8234 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8235 ssh2_pkt_addstring(s->pktout, ssh->username);
8236 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8237 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8238 ssh2_pkt_send(ssh, s->pktout);
8239 s->type = AUTH_TYPE_NONE;
8241 s->we_are_in = FALSE;
8243 s->tried_pubkey_config = FALSE;
8244 s->kbd_inter_refused = FALSE;
8246 /* Reset agent request state. */
8247 s->done_agent = FALSE;
8248 if (s->agent_response) {
8249 if (s->pkblob_in_agent) {
8250 s->agentp = s->pkblob_in_agent;
8252 s->agentp = s->agent_response + 5 + 4;
8258 char *methods = NULL;
8262 * Wait for the result of the last authentication request.
8265 crWaitUntilV(pktin);
8267 * Now is a convenient point to spew any banner material
8268 * that we've accumulated. (This should ensure that when
8269 * we exit the auth loop, we haven't any left to deal
8273 int size = bufchain_size(&ssh->banner);
8275 * Don't show the banner if we're operating in
8276 * non-verbose non-interactive mode. (It's probably
8277 * a script, which means nobody will read the
8278 * banner _anyway_, and moreover the printing of
8279 * the banner will screw up processing on the
8280 * output of (say) plink.)
8282 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8283 char *banner = snewn(size, char);
8284 bufchain_fetch(&ssh->banner, banner, size);
8285 c_write_untrusted(ssh, banner, size);
8288 bufchain_clear(&ssh->banner);
8290 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8291 logevent("Access granted");
8292 s->we_are_in = s->userauth_success = TRUE;
8296 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8297 bombout(("Strange packet received during authentication: "
8298 "type %d", pktin->type));
8305 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8306 * we can look at the string in it and know what we can
8307 * helpfully try next.
8309 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8310 ssh_pkt_getstring(pktin, &methods, &methlen);
8311 if (!ssh2_pkt_getbool(pktin)) {
8313 * We have received an unequivocal Access
8314 * Denied. This can translate to a variety of
8315 * messages, or no message at all.
8317 * For forms of authentication which are attempted
8318 * implicitly, by which I mean without printing
8319 * anything in the window indicating that we're
8320 * trying them, we should never print 'Access
8323 * If we do print a message saying that we're
8324 * attempting some kind of authentication, it's OK
8325 * to print a followup message saying it failed -
8326 * but the message may sometimes be more specific
8327 * than simply 'Access denied'.
8329 * Additionally, if we'd just tried password
8330 * authentication, we should break out of this
8331 * whole loop so as to go back to the username
8332 * prompt (iff we're configured to allow
8333 * username change attempts).
8335 if (s->type == AUTH_TYPE_NONE) {
8337 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8338 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8339 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8340 c_write_str(ssh, "Server refused our key\r\n");
8341 logevent("Server refused our key");
8342 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8343 /* This _shouldn't_ happen except by a
8344 * protocol bug causing client and server to
8345 * disagree on what is a correct signature. */
8346 c_write_str(ssh, "Server refused public-key signature"
8347 " despite accepting key!\r\n");
8348 logevent("Server refused public-key signature"
8349 " despite accepting key!");
8350 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8351 /* quiet, so no c_write */
8352 logevent("Server refused keyboard-interactive authentication");
8353 } else if (s->type==AUTH_TYPE_GSSAPI) {
8354 /* always quiet, so no c_write */
8355 /* also, the code down in the GSSAPI block has
8356 * already logged this in the Event Log */
8357 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8358 logevent("Keyboard-interactive authentication failed");
8359 c_write_str(ssh, "Access denied\r\n");
8361 assert(s->type == AUTH_TYPE_PASSWORD);
8362 logevent("Password authentication failed");
8363 c_write_str(ssh, "Access denied\r\n");
8365 if (conf_get_int(ssh->conf, CONF_change_username)) {
8366 /* XXX perhaps we should allow
8367 * keyboard-interactive to do this too? */
8368 s->we_are_in = FALSE;
8373 c_write_str(ssh, "Further authentication required\r\n");
8374 logevent("Further authentication required");
8378 in_commasep_string("publickey", methods, methlen);
8380 in_commasep_string("password", methods, methlen);
8381 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8382 in_commasep_string("keyboard-interactive", methods, methlen);
8385 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8386 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8387 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8388 ssh->gsslibs->nlibraries > 0;
8392 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8394 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8397 * Attempt public-key authentication using a key from Pageant.
8400 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8402 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8404 /* Unpack key from agent response */
8405 s->pklen = toint(GET_32BIT(s->agentp));
8407 s->pkblob = (char *)s->agentp;
8408 s->agentp += s->pklen;
8409 s->alglen = toint(GET_32BIT(s->pkblob));
8410 s->alg = s->pkblob + 4;
8411 s->commentlen = toint(GET_32BIT(s->agentp));
8413 s->commentp = (char *)s->agentp;
8414 s->agentp += s->commentlen;
8415 /* s->agentp now points at next key, if any */
8417 /* See if server will accept it */
8418 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8419 ssh2_pkt_addstring(s->pktout, ssh->username);
8420 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8421 /* service requested */
8422 ssh2_pkt_addstring(s->pktout, "publickey");
8424 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8425 ssh2_pkt_addstring_start(s->pktout);
8426 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8427 ssh2_pkt_addstring_start(s->pktout);
8428 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8429 ssh2_pkt_send(ssh, s->pktout);
8430 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8432 crWaitUntilV(pktin);
8433 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8435 /* Offer of key refused. */
8442 if (flags & FLAG_VERBOSE) {
8443 c_write_str(ssh, "Authenticating with "
8445 c_write(ssh, s->commentp, s->commentlen);
8446 c_write_str(ssh, "\" from agent\r\n");
8450 * Server is willing to accept the key.
8451 * Construct a SIGN_REQUEST.
8453 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8454 ssh2_pkt_addstring(s->pktout, ssh->username);
8455 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8456 /* service requested */
8457 ssh2_pkt_addstring(s->pktout, "publickey");
8459 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8460 ssh2_pkt_addstring_start(s->pktout);
8461 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8462 ssh2_pkt_addstring_start(s->pktout);
8463 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8465 /* Ask agent for signature. */
8466 s->siglen = s->pktout->length - 5 + 4 +
8467 ssh->v2_session_id_len;
8468 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8470 s->len = 1; /* message type */
8471 s->len += 4 + s->pklen; /* key blob */
8472 s->len += 4 + s->siglen; /* data to sign */
8473 s->len += 4; /* flags */
8474 s->agentreq = snewn(4 + s->len, char);
8475 PUT_32BIT(s->agentreq, s->len);
8476 s->q = s->agentreq + 4;
8477 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8478 PUT_32BIT(s->q, s->pklen);
8480 memcpy(s->q, s->pkblob, s->pklen);
8482 PUT_32BIT(s->q, s->siglen);
8484 /* Now the data to be signed... */
8485 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8486 PUT_32BIT(s->q, ssh->v2_session_id_len);
8489 memcpy(s->q, ssh->v2_session_id,
8490 ssh->v2_session_id_len);
8491 s->q += ssh->v2_session_id_len;
8492 memcpy(s->q, s->pktout->data + 5,
8493 s->pktout->length - 5);
8494 s->q += s->pktout->length - 5;
8495 /* And finally the (zero) flags word. */
8497 if (!agent_query(s->agentreq, s->len + 4,
8499 ssh_agent_callback, ssh)) {
8503 bombout(("Unexpected data from server"
8504 " while waiting for agent"
8508 } while (pktin || inlen > 0);
8509 vret = ssh->agent_response;
8510 s->retlen = ssh->agent_response_len;
8515 if (s->retlen >= 9 &&
8516 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8517 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8518 logevent("Sending Pageant's response");
8519 ssh2_add_sigblob(ssh, s->pktout,
8520 s->pkblob, s->pklen,
8522 GET_32BIT(s->ret + 5));
8523 ssh2_pkt_send(ssh, s->pktout);
8524 s->type = AUTH_TYPE_PUBLICKEY;
8526 /* FIXME: less drastic response */
8527 bombout(("Pageant failed to answer challenge"));
8533 /* Do we have any keys left to try? */
8534 if (s->pkblob_in_agent) {
8535 s->done_agent = TRUE;
8536 s->tried_pubkey_config = TRUE;
8539 if (s->keyi >= s->nkeys)
8540 s->done_agent = TRUE;
8543 } else if (s->can_pubkey && s->publickey_blob &&
8544 !s->tried_pubkey_config) {
8546 struct ssh2_userkey *key; /* not live over crReturn */
8547 char *passphrase; /* not live over crReturn */
8549 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8551 s->tried_pubkey_config = TRUE;
8554 * Try the public key supplied in the configuration.
8556 * First, offer the public blob to see if the server is
8557 * willing to accept it.
8559 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8560 ssh2_pkt_addstring(s->pktout, ssh->username);
8561 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8562 /* service requested */
8563 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8564 ssh2_pkt_addbool(s->pktout, FALSE);
8565 /* no signature included */
8566 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8567 ssh2_pkt_addstring_start(s->pktout);
8568 ssh2_pkt_addstring_data(s->pktout,
8569 (char *)s->publickey_blob,
8570 s->publickey_bloblen);
8571 ssh2_pkt_send(ssh, s->pktout);
8572 logevent("Offered public key");
8574 crWaitUntilV(pktin);
8575 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8576 /* Key refused. Give up. */
8577 s->gotit = TRUE; /* reconsider message next loop */
8578 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8579 continue; /* process this new message */
8581 logevent("Offer of public key accepted");
8584 * Actually attempt a serious authentication using
8587 if (flags & FLAG_VERBOSE) {
8588 c_write_str(ssh, "Authenticating with public key \"");
8589 c_write_str(ssh, s->publickey_comment);
8590 c_write_str(ssh, "\"\r\n");
8594 const char *error; /* not live over crReturn */
8595 if (s->publickey_encrypted) {
8597 * Get a passphrase from the user.
8599 int ret; /* need not be kept over crReturn */
8600 s->cur_prompt = new_prompts(ssh->frontend);
8601 s->cur_prompt->to_server = FALSE;
8602 s->cur_prompt->name = dupstr("SSH key passphrase");
8603 add_prompt(s->cur_prompt,
8604 dupprintf("Passphrase for key \"%.100s\": ",
8605 s->publickey_comment),
8607 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8610 crWaitUntilV(!pktin);
8611 ret = get_userpass_input(s->cur_prompt,
8616 /* Failed to get a passphrase. Terminate. */
8617 free_prompts(s->cur_prompt);
8618 ssh_disconnect(ssh, NULL,
8619 "Unable to authenticate",
8620 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8625 dupstr(s->cur_prompt->prompts[0]->result);
8626 free_prompts(s->cur_prompt);
8628 passphrase = NULL; /* no passphrase needed */
8632 * Try decrypting the key.
8634 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8635 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8637 /* burn the evidence */
8638 smemclr(passphrase, strlen(passphrase));
8641 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8643 (key == SSH2_WRONG_PASSPHRASE)) {
8644 c_write_str(ssh, "Wrong passphrase\r\n");
8646 /* and loop again */
8648 c_write_str(ssh, "Unable to load private key (");
8649 c_write_str(ssh, error);
8650 c_write_str(ssh, ")\r\n");
8652 break; /* try something else */
8658 unsigned char *pkblob, *sigblob, *sigdata;
8659 int pkblob_len, sigblob_len, sigdata_len;
8663 * We have loaded the private key and the server
8664 * has announced that it's willing to accept it.
8665 * Hallelujah. Generate a signature and send it.
8667 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8668 ssh2_pkt_addstring(s->pktout, ssh->username);
8669 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8670 /* service requested */
8671 ssh2_pkt_addstring(s->pktout, "publickey");
8673 ssh2_pkt_addbool(s->pktout, TRUE);
8674 /* signature follows */
8675 ssh2_pkt_addstring(s->pktout, key->alg->name);
8676 pkblob = key->alg->public_blob(key->data,
8678 ssh2_pkt_addstring_start(s->pktout);
8679 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8683 * The data to be signed is:
8687 * followed by everything so far placed in the
8690 sigdata_len = s->pktout->length - 5 + 4 +
8691 ssh->v2_session_id_len;
8692 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8694 sigdata = snewn(sigdata_len, unsigned char);
8696 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8697 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8700 memcpy(sigdata+p, ssh->v2_session_id,
8701 ssh->v2_session_id_len);
8702 p += ssh->v2_session_id_len;
8703 memcpy(sigdata+p, s->pktout->data + 5,
8704 s->pktout->length - 5);
8705 p += s->pktout->length - 5;
8706 assert(p == sigdata_len);
8707 sigblob = key->alg->sign(key->data, (char *)sigdata,
8708 sigdata_len, &sigblob_len);
8709 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8710 sigblob, sigblob_len);
8715 ssh2_pkt_send(ssh, s->pktout);
8716 logevent("Sent public key signature");
8717 s->type = AUTH_TYPE_PUBLICKEY;
8718 key->alg->freekey(key->data);
8722 } else if (s->can_gssapi && !s->tried_gssapi) {
8724 /* GSSAPI Authentication */
8729 s->type = AUTH_TYPE_GSSAPI;
8730 s->tried_gssapi = TRUE;
8732 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8735 * Pick the highest GSS library on the preference
8741 for (i = 0; i < ngsslibs; i++) {
8742 int want_id = conf_get_int_int(ssh->conf,
8743 CONF_ssh_gsslist, i);
8744 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8745 if (ssh->gsslibs->libraries[j].id == want_id) {
8746 s->gsslib = &ssh->gsslibs->libraries[j];
8747 goto got_gsslib; /* double break */
8752 * We always expect to have found something in
8753 * the above loop: we only came here if there
8754 * was at least one viable GSS library, and the
8755 * preference list should always mention
8756 * everything and only change the order.
8761 if (s->gsslib->gsslogmsg)
8762 logevent(s->gsslib->gsslogmsg);
8764 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8765 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8766 ssh2_pkt_addstring(s->pktout, ssh->username);
8767 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8768 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8769 logevent("Attempting GSSAPI authentication");
8771 /* add mechanism info */
8772 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8774 /* number of GSSAPI mechanisms */
8775 ssh2_pkt_adduint32(s->pktout,1);
8777 /* length of OID + 2 */
8778 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8779 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8782 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8784 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8786 ssh2_pkt_send(ssh, s->pktout);
8787 crWaitUntilV(pktin);
8788 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8789 logevent("GSSAPI authentication request refused");
8793 /* check returned packet ... */
8795 ssh_pkt_getstring(pktin, &data, &len);
8796 s->gss_rcvtok.value = data;
8797 s->gss_rcvtok.length = len;
8798 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8799 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8800 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8801 memcmp((char *)s->gss_rcvtok.value + 2,
8802 s->gss_buf.value,s->gss_buf.length) ) {
8803 logevent("GSSAPI authentication - wrong response from server");
8807 /* now start running */
8808 s->gss_stat = s->gsslib->import_name(s->gsslib,
8811 if (s->gss_stat != SSH_GSS_OK) {
8812 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8813 logevent("GSSAPI import name failed - Bad service name");
8815 logevent("GSSAPI import name failed");
8819 /* fetch TGT into GSS engine */
8820 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8822 if (s->gss_stat != SSH_GSS_OK) {
8823 logevent("GSSAPI authentication failed to get credentials");
8824 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8828 /* initial tokens are empty */
8829 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8830 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8832 /* now enter the loop */
8834 s->gss_stat = s->gsslib->init_sec_context
8838 conf_get_int(ssh->conf, CONF_gssapifwd),
8842 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8843 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8844 logevent("GSSAPI authentication initialisation failed");
8846 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8847 &s->gss_buf) == SSH_GSS_OK) {
8848 logevent(s->gss_buf.value);
8849 sfree(s->gss_buf.value);
8854 logevent("GSSAPI authentication initialised");
8856 /* Client and server now exchange tokens until GSSAPI
8857 * no longer says CONTINUE_NEEDED */
8859 if (s->gss_sndtok.length != 0) {
8860 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8861 ssh_pkt_addstring_start(s->pktout);
8862 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8863 ssh2_pkt_send(ssh, s->pktout);
8864 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8867 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8868 crWaitUntilV(pktin);
8869 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8870 logevent("GSSAPI authentication - bad server response");
8871 s->gss_stat = SSH_GSS_FAILURE;
8874 ssh_pkt_getstring(pktin, &data, &len);
8875 s->gss_rcvtok.value = data;
8876 s->gss_rcvtok.length = len;
8878 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8880 if (s->gss_stat != SSH_GSS_OK) {
8881 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8882 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8885 logevent("GSSAPI authentication loop finished OK");
8887 /* Now send the MIC */
8889 s->pktout = ssh2_pkt_init(0);
8890 micoffset = s->pktout->length;
8891 ssh_pkt_addstring_start(s->pktout);
8892 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8893 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8894 ssh_pkt_addstring(s->pktout, ssh->username);
8895 ssh_pkt_addstring(s->pktout, "ssh-connection");
8896 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8898 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8899 s->gss_buf.length = s->pktout->length - micoffset;
8901 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8902 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8903 ssh_pkt_addstring_start(s->pktout);
8904 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8905 ssh2_pkt_send(ssh, s->pktout);
8906 s->gsslib->free_mic(s->gsslib, &mic);
8910 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8911 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8914 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8917 * Keyboard-interactive authentication.
8920 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8922 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8924 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8925 ssh2_pkt_addstring(s->pktout, ssh->username);
8926 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8927 /* service requested */
8928 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8930 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8931 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8932 ssh2_pkt_send(ssh, s->pktout);
8934 logevent("Attempting keyboard-interactive authentication");
8936 crWaitUntilV(pktin);
8937 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8938 /* Server is not willing to do keyboard-interactive
8939 * at all (or, bizarrely but legally, accepts the
8940 * user without actually issuing any prompts).
8941 * Give up on it entirely. */
8943 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8944 s->kbd_inter_refused = TRUE; /* don't try it again */
8949 * Loop while the server continues to send INFO_REQUESTs.
8951 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8953 char *name, *inst, *lang;
8954 int name_len, inst_len, lang_len;
8958 * We've got a fresh USERAUTH_INFO_REQUEST.
8959 * Get the preamble and start building a prompt.
8961 ssh_pkt_getstring(pktin, &name, &name_len);
8962 ssh_pkt_getstring(pktin, &inst, &inst_len);
8963 ssh_pkt_getstring(pktin, &lang, &lang_len);
8964 s->cur_prompt = new_prompts(ssh->frontend);
8965 s->cur_prompt->to_server = TRUE;
8968 * Get any prompt(s) from the packet.
8970 s->num_prompts = ssh_pkt_getuint32(pktin);
8971 for (i = 0; i < s->num_prompts; i++) {
8975 static char noprompt[] =
8976 "<server failed to send prompt>: ";
8978 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8979 echo = ssh2_pkt_getbool(pktin);
8982 prompt_len = lenof(noprompt)-1;
8984 add_prompt(s->cur_prompt,
8985 dupprintf("%.*s", prompt_len, prompt),
8990 /* FIXME: better prefix to distinguish from
8992 s->cur_prompt->name =
8993 dupprintf("SSH server: %.*s", name_len, name);
8994 s->cur_prompt->name_reqd = TRUE;
8996 s->cur_prompt->name =
8997 dupstr("SSH server authentication");
8998 s->cur_prompt->name_reqd = FALSE;
9000 /* We add a prefix to try to make it clear that a prompt
9001 * has come from the server.
9002 * FIXME: ugly to print "Using..." in prompt _every_
9003 * time round. Can this be done more subtly? */
9004 /* Special case: for reasons best known to themselves,
9005 * some servers send k-i requests with no prompts and
9006 * nothing to display. Keep quiet in this case. */
9007 if (s->num_prompts || name_len || inst_len) {
9008 s->cur_prompt->instruction =
9009 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9010 inst_len ? "\n" : "", inst_len, inst);
9011 s->cur_prompt->instr_reqd = TRUE;
9013 s->cur_prompt->instr_reqd = FALSE;
9017 * Display any instructions, and get the user's
9021 int ret; /* not live over crReturn */
9022 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9025 crWaitUntilV(!pktin);
9026 ret = get_userpass_input(s->cur_prompt, in, inlen);
9031 * Failed to get responses. Terminate.
9033 free_prompts(s->cur_prompt);
9034 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9035 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9042 * Send the response(s) to the server.
9044 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9045 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9046 for (i=0; i < s->num_prompts; i++) {
9047 ssh2_pkt_addstring(s->pktout,
9048 s->cur_prompt->prompts[i]->result);
9050 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9053 * Free the prompts structure from this iteration.
9054 * If there's another, a new one will be allocated
9055 * when we return to the top of this while loop.
9057 free_prompts(s->cur_prompt);
9060 * Get the next packet in case it's another
9063 crWaitUntilV(pktin);
9068 * We should have SUCCESS or FAILURE now.
9072 } else if (s->can_passwd) {
9075 * Plain old password authentication.
9077 int ret; /* not live over crReturn */
9078 int changereq_first_time; /* not live over crReturn */
9080 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9082 s->cur_prompt = new_prompts(ssh->frontend);
9083 s->cur_prompt->to_server = TRUE;
9084 s->cur_prompt->name = dupstr("SSH password");
9085 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9090 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9093 crWaitUntilV(!pktin);
9094 ret = get_userpass_input(s->cur_prompt, in, inlen);
9099 * Failed to get responses. Terminate.
9101 free_prompts(s->cur_prompt);
9102 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9103 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9108 * Squirrel away the password. (We may need it later if
9109 * asked to change it.)
9111 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9112 free_prompts(s->cur_prompt);
9115 * Send the password packet.
9117 * We pad out the password packet to 256 bytes to make
9118 * it harder for an attacker to find the length of the
9121 * Anyone using a password longer than 256 bytes
9122 * probably doesn't have much to worry about from
9123 * people who find out how long their password is!
9125 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9126 ssh2_pkt_addstring(s->pktout, ssh->username);
9127 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9128 /* service requested */
9129 ssh2_pkt_addstring(s->pktout, "password");
9130 ssh2_pkt_addbool(s->pktout, FALSE);
9131 ssh2_pkt_addstring(s->pktout, s->password);
9132 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9133 logevent("Sent password");
9134 s->type = AUTH_TYPE_PASSWORD;
9137 * Wait for next packet, in case it's a password change
9140 crWaitUntilV(pktin);
9141 changereq_first_time = TRUE;
9143 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9146 * We're being asked for a new password
9147 * (perhaps not for the first time).
9148 * Loop until the server accepts it.
9151 int got_new = FALSE; /* not live over crReturn */
9152 char *prompt; /* not live over crReturn */
9153 int prompt_len; /* not live over crReturn */
9157 if (changereq_first_time)
9158 msg = "Server requested password change";
9160 msg = "Server rejected new password";
9162 c_write_str(ssh, msg);
9163 c_write_str(ssh, "\r\n");
9166 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9168 s->cur_prompt = new_prompts(ssh->frontend);
9169 s->cur_prompt->to_server = TRUE;
9170 s->cur_prompt->name = dupstr("New SSH password");
9171 s->cur_prompt->instruction =
9172 dupprintf("%.*s", prompt_len, prompt);
9173 s->cur_prompt->instr_reqd = TRUE;
9175 * There's no explicit requirement in the protocol
9176 * for the "old" passwords in the original and
9177 * password-change messages to be the same, and
9178 * apparently some Cisco kit supports password change
9179 * by the user entering a blank password originally
9180 * and the real password subsequently, so,
9181 * reluctantly, we prompt for the old password again.
9183 * (On the other hand, some servers don't even bother
9184 * to check this field.)
9186 add_prompt(s->cur_prompt,
9187 dupstr("Current password (blank for previously entered password): "),
9189 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9191 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9195 * Loop until the user manages to enter the same
9200 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9203 crWaitUntilV(!pktin);
9204 ret = get_userpass_input(s->cur_prompt, in, inlen);
9209 * Failed to get responses. Terminate.
9211 /* burn the evidence */
9212 free_prompts(s->cur_prompt);
9213 smemclr(s->password, strlen(s->password));
9215 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9216 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9222 * If the user specified a new original password
9223 * (IYSWIM), overwrite any previously specified
9225 * (A side effect is that the user doesn't have to
9226 * re-enter it if they louse up the new password.)
9228 if (s->cur_prompt->prompts[0]->result[0]) {
9229 smemclr(s->password, strlen(s->password));
9230 /* burn the evidence */
9233 dupstr(s->cur_prompt->prompts[0]->result);
9237 * Check the two new passwords match.
9239 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9240 s->cur_prompt->prompts[2]->result)
9243 /* They don't. Silly user. */
9244 c_write_str(ssh, "Passwords do not match\r\n");
9249 * Send the new password (along with the old one).
9250 * (see above for padding rationale)
9252 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9253 ssh2_pkt_addstring(s->pktout, ssh->username);
9254 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9255 /* service requested */
9256 ssh2_pkt_addstring(s->pktout, "password");
9257 ssh2_pkt_addbool(s->pktout, TRUE);
9258 ssh2_pkt_addstring(s->pktout, s->password);
9259 ssh2_pkt_addstring(s->pktout,
9260 s->cur_prompt->prompts[1]->result);
9261 free_prompts(s->cur_prompt);
9262 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9263 logevent("Sent new password");
9266 * Now see what the server has to say about it.
9267 * (If it's CHANGEREQ again, it's not happy with the
9270 crWaitUntilV(pktin);
9271 changereq_first_time = FALSE;
9276 * We need to reexamine the current pktin at the top
9277 * of the loop. Either:
9278 * - we weren't asked to change password at all, in
9279 * which case it's a SUCCESS or FAILURE with the
9281 * - we sent a new password, and the server was
9282 * either OK with it (SUCCESS or FAILURE w/partial
9283 * success) or unhappy with the _old_ password
9284 * (FAILURE w/o partial success)
9285 * In any of these cases, we go back to the top of
9286 * the loop and start again.
9291 * We don't need the old password any more, in any
9292 * case. Burn the evidence.
9294 smemclr(s->password, strlen(s->password));
9298 char *str = dupprintf("No supported authentication methods available"
9299 " (server sent: %.*s)",
9302 ssh_disconnect(ssh, str,
9303 "No supported authentication methods available",
9304 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9314 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9316 /* Clear up various bits and pieces from authentication. */
9317 if (s->publickey_blob) {
9318 sfree(s->publickey_blob);
9319 sfree(s->publickey_comment);
9321 if (s->agent_response)
9322 sfree(s->agent_response);
9324 if (s->userauth_success) {
9326 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9327 * packets since. Signal the transport layer to consider enacting
9328 * delayed compression.
9330 * (Relying on we_are_in is not sufficient, as
9331 * draft-miller-secsh-compression-delayed is quite clear that it
9332 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9333 * become set for other reasons.)
9335 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9339 * Now the connection protocol has started, one way or another.
9342 ssh->channels = newtree234(ssh_channelcmp);
9345 * Set up handlers for some connection protocol messages, so we
9346 * don't have to handle them repeatedly in this coroutine.
9348 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9349 ssh2_msg_channel_window_adjust;
9350 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9351 ssh2_msg_global_request;
9354 * Create the main session channel.
9356 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9357 ssh->mainchan = NULL;
9359 ssh->mainchan = snew(struct ssh_channel);
9360 ssh->mainchan->ssh = ssh;
9361 ssh2_channel_init(ssh->mainchan);
9363 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9365 * Just start a direct-tcpip channel and use it as the main
9368 ssh_send_port_open(ssh->mainchan,
9369 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9370 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9374 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9375 logevent("Opening session as main channel");
9376 ssh2_pkt_send(ssh, s->pktout);
9377 ssh->ncmode = FALSE;
9379 crWaitUntilV(pktin);
9380 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9381 bombout(("Server refused to open channel"));
9383 /* FIXME: error data comes back in FAILURE packet */
9385 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9386 bombout(("Server's channel confirmation cited wrong channel"));
9389 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9390 ssh->mainchan->halfopen = FALSE;
9391 ssh->mainchan->type = CHAN_MAINSESSION;
9392 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9393 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9394 add234(ssh->channels, ssh->mainchan);
9395 update_specials_menu(ssh->frontend);
9396 logevent("Opened main channel");
9400 * Now we have a channel, make dispatch table entries for
9401 * general channel-based messages.
9403 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9404 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9405 ssh2_msg_channel_data;
9406 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9407 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9408 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9409 ssh2_msg_channel_open_confirmation;
9410 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9411 ssh2_msg_channel_open_failure;
9412 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9413 ssh2_msg_channel_request;
9414 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9415 ssh2_msg_channel_open;
9416 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9417 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9420 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9422 * This message indicates to the server that we promise
9423 * not to try to run any other channel in parallel with
9424 * this one, so it's safe for it to advertise a very large
9425 * window and leave the flow control to TCP.
9427 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9428 "simple@putty.projects.tartarus.org",
9430 ssh2_pkt_send(ssh, s->pktout);
9434 * Enable port forwardings.
9436 ssh_setup_portfwd(ssh, ssh->conf);
9438 if (ssh->mainchan && !ssh->ncmode) {
9440 * Send the CHANNEL_REQUESTS for the main session channel.
9441 * Each one is handled by its own little asynchronous
9445 /* Potentially enable X11 forwarding. */
9446 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9448 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9449 conf_get_int(ssh->conf, CONF_x11_auth),
9451 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9453 /* Potentially enable agent forwarding. */
9454 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9455 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9457 /* Now allocate a pty for the session. */
9458 if (!conf_get_int(ssh->conf, CONF_nopty))
9459 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9461 /* Send environment variables. */
9462 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9465 * Start a shell or a remote command. We may have to attempt
9466 * this twice if the config data has provided a second choice
9473 if (ssh->fallback_cmd) {
9474 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9475 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9477 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9478 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9482 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9483 ssh2_response_authconn, NULL);
9484 ssh2_pkt_addstring(s->pktout, cmd);
9486 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9487 ssh2_response_authconn, NULL);
9488 ssh2_pkt_addstring(s->pktout, cmd);
9490 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9491 ssh2_response_authconn, NULL);
9493 ssh2_pkt_send(ssh, s->pktout);
9495 crWaitUntilV(pktin);
9497 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9498 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9499 bombout(("Unexpected response to shell/command request:"
9500 " packet type %d", pktin->type));
9504 * We failed to start the command. If this is the
9505 * fallback command, we really are finished; if it's
9506 * not, and if the fallback command exists, try falling
9507 * back to it before complaining.
9509 if (!ssh->fallback_cmd &&
9510 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9511 logevent("Primary command failed; attempting fallback");
9512 ssh->fallback_cmd = TRUE;
9515 bombout(("Server refused to start a shell/command"));
9518 logevent("Started a shell/command");
9523 ssh->editing = ssh->echoing = TRUE;
9526 ssh->state = SSH_STATE_SESSION;
9527 if (ssh->size_needed)
9528 ssh_size(ssh, ssh->term_width, ssh->term_height);
9529 if (ssh->eof_needed)
9530 ssh_special(ssh, TS_EOF);
9536 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9541 s->try_send = FALSE;
9545 * _All_ the connection-layer packets we expect to
9546 * receive are now handled by the dispatch table.
9547 * Anything that reaches here must be bogus.
9550 bombout(("Strange packet received: type %d", pktin->type));
9552 } else if (ssh->mainchan) {
9554 * We have spare data. Add it to the channel buffer.
9556 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9561 struct ssh_channel *c;
9563 * Try to send data on all channels if we can.
9565 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9566 ssh2_try_send_and_unthrottle(ssh, c);
9574 * Handlers for SSH-2 messages that might arrive at any moment.
9576 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9578 /* log reason code in disconnect message */
9582 reason = ssh_pkt_getuint32(pktin);
9583 ssh_pkt_getstring(pktin, &msg, &msglen);
9585 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9586 buf = dupprintf("Received disconnect message (%s)",
9587 ssh2_disconnect_reasons[reason]);
9589 buf = dupprintf("Received disconnect message (unknown"
9590 " type %d)", reason);
9594 buf = dupprintf("Disconnection message text: %.*s",
9597 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9599 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9600 ssh2_disconnect_reasons[reason] : "unknown",
9605 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9607 /* log the debug message */
9611 /* XXX maybe we should actually take notice of the return value */
9612 ssh2_pkt_getbool(pktin);
9613 ssh_pkt_getstring(pktin, &msg, &msglen);
9615 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9618 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9620 do_ssh2_transport(ssh, NULL, 0, pktin);
9624 * Called if we receive a packet that isn't allowed by the protocol.
9625 * This only applies to packets whose meaning PuTTY understands.
9626 * Entirely unknown packets are handled below.
9628 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9630 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9631 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9633 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9637 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9639 struct Packet *pktout;
9640 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9641 ssh2_pkt_adduint32(pktout, pktin->sequence);
9643 * UNIMPLEMENTED messages MUST appear in the same order as the
9644 * messages they respond to. Hence, never queue them.
9646 ssh2_pkt_send_noqueue(ssh, pktout);
9650 * Handle the top-level SSH-2 protocol.
9652 static void ssh2_protocol_setup(Ssh ssh)
9657 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9659 for (i = 0; i < 256; i++)
9660 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9663 * Initially, we only accept transport messages (and a few generic
9664 * ones). do_ssh2_authconn will add more when it starts.
9665 * Messages that are understood but not currently acceptable go to
9666 * ssh2_msg_unexpected.
9668 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9669 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9670 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9671 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9672 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9673 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9674 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9675 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9676 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9677 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9678 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9679 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9680 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9681 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9682 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9683 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9684 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9685 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9686 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9687 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9688 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9689 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9690 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9691 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9692 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9693 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9694 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9695 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9696 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9697 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9698 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9699 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9700 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9703 * These messages have a special handler from the start.
9705 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9706 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9707 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9710 static void ssh2_timer(void *ctx, unsigned long now)
9714 if (ssh->state == SSH_STATE_CLOSED)
9717 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9718 now == ssh->next_rekey) {
9719 do_ssh2_transport(ssh, "timeout", -1, NULL);
9723 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9724 struct Packet *pktin)
9726 unsigned char *in = (unsigned char *)vin;
9727 if (ssh->state == SSH_STATE_CLOSED)
9731 ssh->incoming_data_size += pktin->encrypted_len;
9732 if (!ssh->kex_in_progress &&
9733 ssh->max_data_size != 0 &&
9734 ssh->incoming_data_size > ssh->max_data_size)
9735 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9739 ssh->packet_dispatch[pktin->type](ssh, pktin);
9740 else if (!ssh->protocol_initial_phase_done)
9741 do_ssh2_transport(ssh, in, inlen, pktin);
9743 do_ssh2_authconn(ssh, in, inlen, pktin);
9746 static void ssh_cache_conf_values(Ssh ssh)
9748 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9752 * Called to set up the connection.
9754 * Returns an error message, or NULL on success.
9756 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9757 Conf *conf, char *host, int port, char **realhost,
9758 int nodelay, int keepalive)
9763 ssh = snew(struct ssh_tag);
9764 ssh->conf = conf_copy(conf);
9765 ssh_cache_conf_values(ssh);
9766 ssh->version = 0; /* when not ready yet */
9769 ssh->v1_cipher_ctx = NULL;
9770 ssh->crcda_ctx = NULL;
9771 ssh->cscipher = NULL;
9772 ssh->cs_cipher_ctx = NULL;
9773 ssh->sccipher = NULL;
9774 ssh->sc_cipher_ctx = NULL;
9776 ssh->cs_mac_ctx = NULL;
9778 ssh->sc_mac_ctx = NULL;
9780 ssh->cs_comp_ctx = NULL;
9782 ssh->sc_comp_ctx = NULL;
9784 ssh->kex_ctx = NULL;
9785 ssh->hostkey = NULL;
9786 ssh->hostkey_str = NULL;
9788 ssh->close_expected = FALSE;
9789 ssh->clean_exit = FALSE;
9790 ssh->state = SSH_STATE_PREPACKET;
9791 ssh->size_needed = FALSE;
9792 ssh->eof_needed = FALSE;
9795 ssh->deferred_send_data = NULL;
9796 ssh->deferred_len = 0;
9797 ssh->deferred_size = 0;
9798 ssh->fallback_cmd = 0;
9799 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9800 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9801 ssh->x11disp = NULL;
9802 ssh->v1_compressing = FALSE;
9803 ssh->v2_outgoing_sequence = 0;
9804 ssh->ssh1_rdpkt_crstate = 0;
9805 ssh->ssh2_rdpkt_crstate = 0;
9806 ssh->ssh_gotdata_crstate = 0;
9807 ssh->do_ssh1_connection_crstate = 0;
9808 ssh->do_ssh_init_state = NULL;
9809 ssh->do_ssh1_login_state = NULL;
9810 ssh->do_ssh2_transport_state = NULL;
9811 ssh->do_ssh2_authconn_state = NULL;
9814 ssh->mainchan = NULL;
9815 ssh->throttled_all = 0;
9816 ssh->v1_stdout_throttling = 0;
9818 ssh->queuelen = ssh->queuesize = 0;
9819 ssh->queueing = FALSE;
9820 ssh->qhead = ssh->qtail = NULL;
9821 ssh->deferred_rekey_reason = NULL;
9822 bufchain_init(&ssh->queued_incoming_data);
9823 ssh->frozen = FALSE;
9824 ssh->username = NULL;
9825 ssh->sent_console_eof = FALSE;
9826 ssh->got_pty = FALSE;
9828 *backend_handle = ssh;
9831 if (crypto_startup() == 0)
9832 return "Microsoft high encryption pack not installed!";
9835 ssh->frontend = frontend_handle;
9836 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9837 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9839 ssh->channels = NULL;
9840 ssh->rportfwds = NULL;
9841 ssh->portfwds = NULL;
9846 ssh->conn_throttle_count = 0;
9847 ssh->overall_bufsize = 0;
9848 ssh->fallback_cmd = 0;
9850 ssh->protocol = NULL;
9852 ssh->protocol_initial_phase_done = FALSE;
9856 ssh->incoming_data_size = ssh->outgoing_data_size =
9857 ssh->deferred_data_size = 0L;
9858 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9859 CONF_ssh_rekey_data));
9860 ssh->kex_in_progress = FALSE;
9863 ssh->gsslibs = NULL;
9866 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9875 static void ssh_free(void *handle)
9877 Ssh ssh = (Ssh) handle;
9878 struct ssh_channel *c;
9879 struct ssh_rportfwd *pf;
9881 if (ssh->v1_cipher_ctx)
9882 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9883 if (ssh->cs_cipher_ctx)
9884 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9885 if (ssh->sc_cipher_ctx)
9886 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9887 if (ssh->cs_mac_ctx)
9888 ssh->csmac->free_context(ssh->cs_mac_ctx);
9889 if (ssh->sc_mac_ctx)
9890 ssh->scmac->free_context(ssh->sc_mac_ctx);
9891 if (ssh->cs_comp_ctx) {
9893 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9895 zlib_compress_cleanup(ssh->cs_comp_ctx);
9897 if (ssh->sc_comp_ctx) {
9899 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9901 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9904 dh_cleanup(ssh->kex_ctx);
9905 sfree(ssh->savedhost);
9907 while (ssh->queuelen-- > 0)
9908 ssh_free_packet(ssh->queue[ssh->queuelen]);
9911 while (ssh->qhead) {
9912 struct queued_handler *qh = ssh->qhead;
9913 ssh->qhead = qh->next;
9916 ssh->qhead = ssh->qtail = NULL;
9918 if (ssh->channels) {
9919 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9922 if (c->u.x11.xconn != NULL)
9923 x11_close(c->u.x11.xconn);
9926 case CHAN_SOCKDATA_DORMANT:
9927 if (c->u.pfd.pf != NULL)
9928 pfd_close(c->u.pfd.pf);
9931 if (ssh->version == 2) {
9932 struct outstanding_channel_request *ocr, *nocr;
9933 ocr = c->v.v2.chanreq_head;
9935 ocr->handler(c, NULL, ocr->ctx);
9940 bufchain_clear(&c->v.v2.outbuffer);
9944 freetree234(ssh->channels);
9945 ssh->channels = NULL;
9948 if (ssh->rportfwds) {
9949 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9951 freetree234(ssh->rportfwds);
9952 ssh->rportfwds = NULL;
9954 sfree(ssh->deferred_send_data);
9956 x11_free_display(ssh->x11disp);
9957 sfree(ssh->do_ssh_init_state);
9958 sfree(ssh->do_ssh1_login_state);
9959 sfree(ssh->do_ssh2_transport_state);
9960 sfree(ssh->do_ssh2_authconn_state);
9963 sfree(ssh->fullhostname);
9964 sfree(ssh->hostkey_str);
9965 if (ssh->crcda_ctx) {
9966 crcda_free_context(ssh->crcda_ctx);
9967 ssh->crcda_ctx = NULL;
9970 ssh_do_close(ssh, TRUE);
9971 expire_timer_context(ssh);
9973 pinger_free(ssh->pinger);
9974 bufchain_clear(&ssh->queued_incoming_data);
9975 sfree(ssh->username);
9976 conf_free(ssh->conf);
9979 ssh_gss_cleanup(ssh->gsslibs);
9987 * Reconfigure the SSH backend.
9989 static void ssh_reconfig(void *handle, Conf *conf)
9991 Ssh ssh = (Ssh) handle;
9992 char *rekeying = NULL, rekey_mandatory = FALSE;
9993 unsigned long old_max_data_size;
9996 pinger_reconfig(ssh->pinger, ssh->conf, conf);
9998 ssh_setup_portfwd(ssh, conf);
10000 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10001 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10003 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10004 unsigned long now = GETTICKCOUNT();
10006 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10007 rekeying = "timeout shortened";
10009 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10013 old_max_data_size = ssh->max_data_size;
10014 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10015 CONF_ssh_rekey_data));
10016 if (old_max_data_size != ssh->max_data_size &&
10017 ssh->max_data_size != 0) {
10018 if (ssh->outgoing_data_size > ssh->max_data_size ||
10019 ssh->incoming_data_size > ssh->max_data_size)
10020 rekeying = "data limit lowered";
10023 if (conf_get_int(ssh->conf, CONF_compression) !=
10024 conf_get_int(conf, CONF_compression)) {
10025 rekeying = "compression setting changed";
10026 rekey_mandatory = TRUE;
10029 for (i = 0; i < CIPHER_MAX; i++)
10030 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10031 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10032 rekeying = "cipher settings changed";
10033 rekey_mandatory = TRUE;
10035 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10036 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10037 rekeying = "cipher settings changed";
10038 rekey_mandatory = TRUE;
10041 conf_free(ssh->conf);
10042 ssh->conf = conf_copy(conf);
10043 ssh_cache_conf_values(ssh);
10046 if (!ssh->kex_in_progress) {
10047 do_ssh2_transport(ssh, rekeying, -1, NULL);
10048 } else if (rekey_mandatory) {
10049 ssh->deferred_rekey_reason = rekeying;
10055 * Called to send data down the SSH connection.
10057 static int ssh_send(void *handle, char *buf, int len)
10059 Ssh ssh = (Ssh) handle;
10061 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10064 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10066 return ssh_sendbuffer(ssh);
10070 * Called to query the current amount of buffered stdin data.
10072 static int ssh_sendbuffer(void *handle)
10074 Ssh ssh = (Ssh) handle;
10075 int override_value;
10077 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10081 * If the SSH socket itself has backed up, add the total backup
10082 * size on that to any individual buffer on the stdin channel.
10084 override_value = 0;
10085 if (ssh->throttled_all)
10086 override_value = ssh->overall_bufsize;
10088 if (ssh->version == 1) {
10089 return override_value;
10090 } else if (ssh->version == 2) {
10091 if (!ssh->mainchan)
10092 return override_value;
10094 return (override_value +
10095 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10102 * Called to set the size of the window from SSH's POV.
10104 static void ssh_size(void *handle, int width, int height)
10106 Ssh ssh = (Ssh) handle;
10107 struct Packet *pktout;
10109 ssh->term_width = width;
10110 ssh->term_height = height;
10112 switch (ssh->state) {
10113 case SSH_STATE_BEFORE_SIZE:
10114 case SSH_STATE_PREPACKET:
10115 case SSH_STATE_CLOSED:
10116 break; /* do nothing */
10117 case SSH_STATE_INTERMED:
10118 ssh->size_needed = TRUE; /* buffer for later */
10120 case SSH_STATE_SESSION:
10121 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10122 if (ssh->version == 1) {
10123 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10124 PKT_INT, ssh->term_height,
10125 PKT_INT, ssh->term_width,
10126 PKT_INT, 0, PKT_INT, 0, PKT_END);
10127 } else if (ssh->mainchan) {
10128 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10130 ssh2_pkt_adduint32(pktout, ssh->term_width);
10131 ssh2_pkt_adduint32(pktout, ssh->term_height);
10132 ssh2_pkt_adduint32(pktout, 0);
10133 ssh2_pkt_adduint32(pktout, 0);
10134 ssh2_pkt_send(ssh, pktout);
10142 * Return a list of the special codes that make sense in this
10145 static const struct telnet_special *ssh_get_specials(void *handle)
10147 static const struct telnet_special ssh1_ignore_special[] = {
10148 {"IGNORE message", TS_NOP}
10150 static const struct telnet_special ssh2_ignore_special[] = {
10151 {"IGNORE message", TS_NOP},
10153 static const struct telnet_special ssh2_rekey_special[] = {
10154 {"Repeat key exchange", TS_REKEY},
10156 static const struct telnet_special ssh2_session_specials[] = {
10159 /* These are the signal names defined by RFC 4254.
10160 * They include all the ISO C signals, but are a subset of the POSIX
10161 * required signals. */
10162 {"SIGINT (Interrupt)", TS_SIGINT},
10163 {"SIGTERM (Terminate)", TS_SIGTERM},
10164 {"SIGKILL (Kill)", TS_SIGKILL},
10165 {"SIGQUIT (Quit)", TS_SIGQUIT},
10166 {"SIGHUP (Hangup)", TS_SIGHUP},
10167 {"More signals", TS_SUBMENU},
10168 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10169 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10170 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10171 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10172 {NULL, TS_EXITMENU}
10174 static const struct telnet_special specials_end[] = {
10175 {NULL, TS_EXITMENU}
10177 /* XXX review this length for any changes: */
10178 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10179 lenof(ssh2_rekey_special) +
10180 lenof(ssh2_session_specials) +
10181 lenof(specials_end)];
10182 Ssh ssh = (Ssh) handle;
10184 #define ADD_SPECIALS(name) \
10186 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10187 memcpy(&ssh_specials[i], name, sizeof name); \
10188 i += lenof(name); \
10191 if (ssh->version == 1) {
10192 /* Don't bother offering IGNORE if we've decided the remote
10193 * won't cope with it, since we wouldn't bother sending it if
10195 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10196 ADD_SPECIALS(ssh1_ignore_special);
10197 } else if (ssh->version == 2) {
10198 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10199 ADD_SPECIALS(ssh2_ignore_special);
10200 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10201 ADD_SPECIALS(ssh2_rekey_special);
10203 ADD_SPECIALS(ssh2_session_specials);
10204 } /* else we're not ready yet */
10207 ADD_SPECIALS(specials_end);
10208 return ssh_specials;
10212 #undef ADD_SPECIALS
10216 * Send special codes. TS_EOF is useful for `plink', so you
10217 * can send an EOF and collect resulting output (e.g. `plink
10220 static void ssh_special(void *handle, Telnet_Special code)
10222 Ssh ssh = (Ssh) handle;
10223 struct Packet *pktout;
10225 if (code == TS_EOF) {
10226 if (ssh->state != SSH_STATE_SESSION) {
10228 * Buffer the EOF in case we are pre-SESSION, so we can
10229 * send it as soon as we reach SESSION.
10231 if (code == TS_EOF)
10232 ssh->eof_needed = TRUE;
10235 if (ssh->version == 1) {
10236 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10237 } else if (ssh->mainchan) {
10238 sshfwd_write_eof(ssh->mainchan);
10239 ssh->send_ok = 0; /* now stop trying to read from stdin */
10241 logevent("Sent EOF message");
10242 } else if (code == TS_PING || code == TS_NOP) {
10243 if (ssh->state == SSH_STATE_CLOSED
10244 || ssh->state == SSH_STATE_PREPACKET) return;
10245 if (ssh->version == 1) {
10246 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10247 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10249 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10250 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10251 ssh2_pkt_addstring_start(pktout);
10252 ssh2_pkt_send_noqueue(ssh, pktout);
10255 } else if (code == TS_REKEY) {
10256 if (!ssh->kex_in_progress && ssh->version == 2) {
10257 do_ssh2_transport(ssh, "at user request", -1, NULL);
10259 } else if (code == TS_BRK) {
10260 if (ssh->state == SSH_STATE_CLOSED
10261 || ssh->state == SSH_STATE_PREPACKET) return;
10262 if (ssh->version == 1) {
10263 logevent("Unable to send BREAK signal in SSH-1");
10264 } else if (ssh->mainchan) {
10265 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10266 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10267 ssh2_pkt_send(ssh, pktout);
10270 /* Is is a POSIX signal? */
10271 char *signame = NULL;
10272 if (code == TS_SIGABRT) signame = "ABRT";
10273 if (code == TS_SIGALRM) signame = "ALRM";
10274 if (code == TS_SIGFPE) signame = "FPE";
10275 if (code == TS_SIGHUP) signame = "HUP";
10276 if (code == TS_SIGILL) signame = "ILL";
10277 if (code == TS_SIGINT) signame = "INT";
10278 if (code == TS_SIGKILL) signame = "KILL";
10279 if (code == TS_SIGPIPE) signame = "PIPE";
10280 if (code == TS_SIGQUIT) signame = "QUIT";
10281 if (code == TS_SIGSEGV) signame = "SEGV";
10282 if (code == TS_SIGTERM) signame = "TERM";
10283 if (code == TS_SIGUSR1) signame = "USR1";
10284 if (code == TS_SIGUSR2) signame = "USR2";
10285 /* The SSH-2 protocol does in principle support arbitrary named
10286 * signals, including signame@domain, but we don't support those. */
10288 /* It's a signal. */
10289 if (ssh->version == 2 && ssh->mainchan) {
10290 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10291 ssh2_pkt_addstring(pktout, signame);
10292 ssh2_pkt_send(ssh, pktout);
10293 logeventf(ssh, "Sent signal SIG%s", signame);
10296 /* Never heard of it. Do nothing */
10301 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10303 Ssh ssh = (Ssh) handle;
10304 struct ssh_channel *c;
10305 c = snew(struct ssh_channel);
10308 ssh2_channel_init(c);
10309 c->halfopen = TRUE;
10310 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10312 add234(ssh->channels, c);
10317 * This is called when stdout/stderr (the entity to which
10318 * from_backend sends data) manages to clear some backlog.
10320 static void ssh_unthrottle(void *handle, int bufsize)
10322 Ssh ssh = (Ssh) handle;
10325 if (ssh->version == 1) {
10326 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10327 ssh->v1_stdout_throttling = 0;
10328 ssh_throttle_conn(ssh, -1);
10331 if (ssh->mainchan) {
10332 ssh2_set_window(ssh->mainchan,
10333 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10334 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10335 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10338 buflimit = ssh->mainchan->v.v2.locmaxwin;
10339 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10340 ssh->mainchan->throttling_conn = 0;
10341 ssh_throttle_conn(ssh, -1);
10347 * Now process any SSH connection data that was stashed in our
10348 * queue while we were frozen.
10350 ssh_process_queued_incoming_data(ssh);
10353 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10355 struct ssh_channel *c = (struct ssh_channel *)channel;
10357 struct Packet *pktout;
10359 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10361 if (ssh->version == 1) {
10362 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10363 PKT_INT, c->localid,
10366 /* PKT_STR, <org:orgport>, */
10369 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10370 ssh2_pkt_addstring(pktout, hostname);
10371 ssh2_pkt_adduint32(pktout, port);
10373 * We make up values for the originator data; partly it's
10374 * too much hassle to keep track, and partly I'm not
10375 * convinced the server should be told details like that
10376 * about my local network configuration.
10377 * The "originator IP address" is syntactically a numeric
10378 * IP address, and some servers (e.g., Tectia) get upset
10379 * if it doesn't match this syntax.
10381 ssh2_pkt_addstring(pktout, "0.0.0.0");
10382 ssh2_pkt_adduint32(pktout, 0);
10383 ssh2_pkt_send(ssh, pktout);
10387 static int ssh_connected(void *handle)
10389 Ssh ssh = (Ssh) handle;
10390 return ssh->s != NULL;
10393 static int ssh_sendok(void *handle)
10395 Ssh ssh = (Ssh) handle;
10396 return ssh->send_ok;
10399 static int ssh_ldisc(void *handle, int option)
10401 Ssh ssh = (Ssh) handle;
10402 if (option == LD_ECHO)
10403 return ssh->echoing;
10404 if (option == LD_EDIT)
10405 return ssh->editing;
10409 static void ssh_provide_ldisc(void *handle, void *ldisc)
10411 Ssh ssh = (Ssh) handle;
10412 ssh->ldisc = ldisc;
10415 static void ssh_provide_logctx(void *handle, void *logctx)
10417 Ssh ssh = (Ssh) handle;
10418 ssh->logctx = logctx;
10421 static int ssh_return_exitcode(void *handle)
10423 Ssh ssh = (Ssh) handle;
10424 if (ssh->s != NULL)
10427 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10431 * cfg_info for SSH is the currently running version of the
10432 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10434 static int ssh_cfg_info(void *handle)
10436 Ssh ssh = (Ssh) handle;
10437 return ssh->version;
10441 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10442 * that fails. This variable is the means by which scp.c can reach
10443 * into the SSH code and find out which one it got.
10445 extern int ssh_fallback_cmd(void *handle)
10447 Ssh ssh = (Ssh) handle;
10448 return ssh->fallback_cmd;
10451 Backend ssh_backend = {
10461 ssh_return_exitcode,
10465 ssh_provide_logctx,