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 Conf *sshfwd_get_conf(struct ssh_channel *c)
4364 void sshfwd_write_eof(struct ssh_channel *c)
4368 if (ssh->state == SSH_STATE_CLOSED)
4371 if (c->closes & CLOSES_SENT_EOF)
4374 c->pending_eof = TRUE;
4375 ssh_channel_try_eof(c);
4378 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4382 if (ssh->state == SSH_STATE_CLOSED)
4387 x11_close(c->u.x11.xconn);
4388 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4392 case CHAN_SOCKDATA_DORMANT:
4393 pfd_close(c->u.pfd.pf);
4394 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4397 c->type = CHAN_ZOMBIE;
4398 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4400 ssh2_channel_check_close(c);
4403 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4407 if (ssh->state == SSH_STATE_CLOSED)
4410 if (ssh->version == 1) {
4411 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4412 PKT_INT, c->remoteid,
4413 PKT_INT, len, PKT_DATA, buf, len,
4416 * In SSH-1 we can return 0 here - implying that forwarded
4417 * connections are never individually throttled - because
4418 * the only circumstance that can cause throttling will be
4419 * the whole SSH connection backing up, in which case
4420 * _everything_ will be throttled as a whole.
4424 ssh2_add_channel_data(c, buf, len);
4425 return ssh2_try_send(c);
4429 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4434 if (ssh->state == SSH_STATE_CLOSED)
4437 if (ssh->version == 1) {
4438 buflimit = SSH1_BUFFER_LIMIT;
4440 buflimit = c->v.v2.locmaxwin;
4441 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4443 if (c->throttling_conn && bufsize <= buflimit) {
4444 c->throttling_conn = 0;
4445 ssh_throttle_conn(ssh, -1);
4449 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4451 struct queued_handler *qh = ssh->qhead;
4455 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4458 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4459 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4462 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4463 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4467 ssh->qhead = qh->next;
4469 if (ssh->qhead->msg1 > 0) {
4470 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4471 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4473 if (ssh->qhead->msg2 > 0) {
4474 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4475 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4478 ssh->qhead = ssh->qtail = NULL;
4481 qh->handler(ssh, pktin, qh->ctx);
4486 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4487 chandler_fn_t handler, void *ctx)
4489 struct queued_handler *qh;
4491 qh = snew(struct queued_handler);
4494 qh->handler = handler;
4498 if (ssh->qtail == NULL) {
4502 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4503 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4506 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4507 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4510 ssh->qtail->next = qh;
4515 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4517 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4519 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4520 SSH2_MSG_REQUEST_SUCCESS)) {
4521 logeventf(ssh, "Remote port forwarding from %s enabled",
4524 logeventf(ssh, "Remote port forwarding from %s refused",
4527 rpf = del234(ssh->rportfwds, pf);
4529 pf->pfrec->remote = NULL;
4534 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4536 struct ssh_portfwd *epf;
4540 if (!ssh->portfwds) {
4541 ssh->portfwds = newtree234(ssh_portcmp);
4544 * Go through the existing port forwardings and tag them
4545 * with status==DESTROY. Any that we want to keep will be
4546 * re-enabled (status==KEEP) as we go through the
4547 * configuration and find out which bits are the same as
4550 struct ssh_portfwd *epf;
4552 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4553 epf->status = DESTROY;
4556 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4558 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4559 char *kp, *kp2, *vp, *vp2;
4560 char address_family, type;
4561 int sport,dport,sserv,dserv;
4562 char *sports, *dports, *saddr, *host;
4566 address_family = 'A';
4568 if (*kp == 'A' || *kp == '4' || *kp == '6')
4569 address_family = *kp++;
4570 if (*kp == 'L' || *kp == 'R')
4573 if ((kp2 = strchr(kp, ':')) != NULL) {
4575 * There's a colon in the middle of the source port
4576 * string, which means that the part before it is
4577 * actually a source address.
4579 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4585 sport = atoi(sports);
4589 sport = net_service_lookup(sports);
4591 logeventf(ssh, "Service lookup failed for source"
4592 " port \"%s\"", sports);
4596 if (type == 'L' && !strcmp(val, "D")) {
4597 /* dynamic forwarding */
4604 /* ordinary forwarding */
4606 vp2 = vp + strcspn(vp, ":");
4607 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4611 dport = atoi(dports);
4615 dport = net_service_lookup(dports);
4617 logeventf(ssh, "Service lookup failed for destination"
4618 " port \"%s\"", dports);
4623 if (sport && dport) {
4624 /* Set up a description of the source port. */
4625 struct ssh_portfwd *pfrec, *epfrec;
4627 pfrec = snew(struct ssh_portfwd);
4629 pfrec->saddr = saddr;
4630 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4631 pfrec->sport = sport;
4632 pfrec->daddr = host;
4633 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4634 pfrec->dport = dport;
4635 pfrec->local = NULL;
4636 pfrec->remote = NULL;
4637 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4638 address_family == '6' ? ADDRTYPE_IPV6 :
4641 epfrec = add234(ssh->portfwds, pfrec);
4642 if (epfrec != pfrec) {
4643 if (epfrec->status == DESTROY) {
4645 * We already have a port forwarding up and running
4646 * with precisely these parameters. Hence, no need
4647 * to do anything; simply re-tag the existing one
4650 epfrec->status = KEEP;
4653 * Anything else indicates that there was a duplicate
4654 * in our input, which we'll silently ignore.
4656 free_portfwd(pfrec);
4658 pfrec->status = CREATE;
4667 * Now go through and destroy any port forwardings which were
4670 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4671 if (epf->status == DESTROY) {
4674 message = dupprintf("%s port forwarding from %s%s%d",
4675 epf->type == 'L' ? "local" :
4676 epf->type == 'R' ? "remote" : "dynamic",
4677 epf->saddr ? epf->saddr : "",
4678 epf->saddr ? ":" : "",
4681 if (epf->type != 'D') {
4682 char *msg2 = dupprintf("%s to %s:%d", message,
4683 epf->daddr, epf->dport);
4688 logeventf(ssh, "Cancelling %s", message);
4691 /* epf->remote or epf->local may be NULL if setting up a
4692 * forwarding failed. */
4694 struct ssh_rportfwd *rpf = epf->remote;
4695 struct Packet *pktout;
4698 * Cancel the port forwarding at the server
4701 if (ssh->version == 1) {
4703 * We cannot cancel listening ports on the
4704 * server side in SSH-1! There's no message
4705 * to support it. Instead, we simply remove
4706 * the rportfwd record from the local end
4707 * so that any connections the server tries
4708 * to make on it are rejected.
4711 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4712 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4713 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4715 ssh2_pkt_addstring(pktout, epf->saddr);
4716 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4717 /* XXX: rport_acceptall may not represent
4718 * what was used to open the original connection,
4719 * since it's reconfigurable. */
4720 ssh2_pkt_addstring(pktout, "");
4722 ssh2_pkt_addstring(pktout, "localhost");
4724 ssh2_pkt_adduint32(pktout, epf->sport);
4725 ssh2_pkt_send(ssh, pktout);
4728 del234(ssh->rportfwds, rpf);
4730 } else if (epf->local) {
4731 pfl_terminate(epf->local);
4734 delpos234(ssh->portfwds, i);
4736 i--; /* so we don't skip one in the list */
4740 * And finally, set up any new port forwardings (status==CREATE).
4742 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4743 if (epf->status == CREATE) {
4744 char *sportdesc, *dportdesc;
4745 sportdesc = dupprintf("%s%s%s%s%d%s",
4746 epf->saddr ? epf->saddr : "",
4747 epf->saddr ? ":" : "",
4748 epf->sserv ? epf->sserv : "",
4749 epf->sserv ? "(" : "",
4751 epf->sserv ? ")" : "");
4752 if (epf->type == 'D') {
4755 dportdesc = dupprintf("%s:%s%s%d%s",
4757 epf->dserv ? epf->dserv : "",
4758 epf->dserv ? "(" : "",
4760 epf->dserv ? ")" : "");
4763 if (epf->type == 'L') {
4764 char *err = pfl_listen(epf->daddr, epf->dport,
4765 epf->saddr, epf->sport,
4766 ssh, conf, &epf->local,
4767 epf->addressfamily);
4769 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4770 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4771 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4772 sportdesc, dportdesc,
4773 err ? " failed: " : "", err ? err : "");
4776 } else if (epf->type == 'D') {
4777 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
4778 ssh, conf, &epf->local,
4779 epf->addressfamily);
4781 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4782 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4783 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4785 err ? " failed: " : "", err ? err : "");
4790 struct ssh_rportfwd *pf;
4793 * Ensure the remote port forwardings tree exists.
4795 if (!ssh->rportfwds) {
4796 if (ssh->version == 1)
4797 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4799 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4802 pf = snew(struct ssh_rportfwd);
4803 pf->dhost = dupstr(epf->daddr);
4804 pf->dport = epf->dport;
4806 pf->shost = dupstr(epf->saddr);
4807 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4808 pf->shost = dupstr("");
4810 pf->shost = dupstr("localhost");
4812 pf->sport = epf->sport;
4813 if (add234(ssh->rportfwds, pf) != pf) {
4814 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4815 epf->daddr, epf->dport);
4818 logeventf(ssh, "Requesting remote port %s"
4819 " forward to %s", sportdesc, dportdesc);
4821 pf->sportdesc = sportdesc;
4826 if (ssh->version == 1) {
4827 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4828 PKT_INT, epf->sport,
4829 PKT_STR, epf->daddr,
4830 PKT_INT, epf->dport,
4832 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4834 ssh_rportfwd_succfail, pf);
4836 struct Packet *pktout;
4837 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4838 ssh2_pkt_addstring(pktout, "tcpip-forward");
4839 ssh2_pkt_addbool(pktout, 1);/* want reply */
4840 ssh2_pkt_addstring(pktout, pf->shost);
4841 ssh2_pkt_adduint32(pktout, pf->sport);
4842 ssh2_pkt_send(ssh, pktout);
4844 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4845 SSH2_MSG_REQUEST_FAILURE,
4846 ssh_rportfwd_succfail, pf);
4855 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4858 int stringlen, bufsize;
4860 ssh_pkt_getstring(pktin, &string, &stringlen);
4861 if (string == NULL) {
4862 bombout(("Incoming terminal data packet was badly formed"));
4866 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4868 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4869 ssh->v1_stdout_throttling = 1;
4870 ssh_throttle_conn(ssh, +1);
4874 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4876 /* Remote side is trying to open a channel to talk to our
4877 * X-Server. Give them back a local channel number. */
4878 struct ssh_channel *c;
4879 int remoteid = ssh_pkt_getuint32(pktin);
4881 logevent("Received X11 connect request");
4882 /* Refuse if X11 forwarding is disabled. */
4883 if (!ssh->X11_fwd_enabled) {
4884 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4885 PKT_INT, remoteid, PKT_END);
4886 logevent("Rejected X11 connect request");
4890 c = snew(struct ssh_channel);
4893 if ((err = x11_init(&c->u.x11.xconn, ssh->x11disp, c,
4894 NULL, -1)) != NULL) {
4895 logeventf(ssh, "Opening X11 forward connection failed: %s", err);
4898 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4899 PKT_INT, remoteid, PKT_END);
4902 ("Opening X11 forward connection succeeded");
4903 c->remoteid = remoteid;
4904 c->halfopen = FALSE;
4905 c->localid = alloc_channel_id(ssh);
4907 c->pending_eof = FALSE;
4908 c->throttling_conn = 0;
4909 c->type = CHAN_X11; /* identify channel type */
4910 add234(ssh->channels, c);
4911 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4912 PKT_INT, c->remoteid, PKT_INT,
4913 c->localid, PKT_END);
4914 logevent("Opened X11 forward channel");
4919 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4921 /* Remote side is trying to open a channel to talk to our
4922 * agent. Give them back a local channel number. */
4923 struct ssh_channel *c;
4924 int remoteid = ssh_pkt_getuint32(pktin);
4926 /* Refuse if agent forwarding is disabled. */
4927 if (!ssh->agentfwd_enabled) {
4928 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4929 PKT_INT, remoteid, PKT_END);
4931 c = snew(struct ssh_channel);
4933 c->remoteid = remoteid;
4934 c->halfopen = FALSE;
4935 c->localid = alloc_channel_id(ssh);
4937 c->pending_eof = FALSE;
4938 c->throttling_conn = 0;
4939 c->type = CHAN_AGENT; /* identify channel type */
4940 c->u.a.lensofar = 0;
4941 c->u.a.message = NULL;
4942 c->u.a.outstanding_requests = 0;
4943 add234(ssh->channels, c);
4944 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4945 PKT_INT, c->remoteid, PKT_INT, c->localid,
4950 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4952 /* Remote side is trying to open a channel to talk to a
4953 * forwarded port. Give them back a local channel number. */
4954 struct ssh_rportfwd pf, *pfp;
4960 remoteid = ssh_pkt_getuint32(pktin);
4961 ssh_pkt_getstring(pktin, &host, &hostsize);
4962 port = ssh_pkt_getuint32(pktin);
4964 pf.dhost = dupprintf(".*s", hostsize, host);
4966 pfp = find234(ssh->rportfwds, &pf, NULL);
4969 logeventf(ssh, "Rejected remote port open request for %s:%d",
4971 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4972 PKT_INT, remoteid, PKT_END);
4974 struct ssh_channel *c = snew(struct ssh_channel);
4977 logeventf(ssh, "Received remote port open request for %s:%d",
4979 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
4980 c, ssh->conf, pfp->pfrec->addressfamily);
4982 logeventf(ssh, "Port open failed: %s", err);
4985 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4986 PKT_INT, remoteid, PKT_END);
4988 c->remoteid = remoteid;
4989 c->halfopen = FALSE;
4990 c->localid = alloc_channel_id(ssh);
4992 c->pending_eof = FALSE;
4993 c->throttling_conn = 0;
4994 c->type = CHAN_SOCKDATA; /* identify channel type */
4995 add234(ssh->channels, c);
4996 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4997 PKT_INT, c->remoteid, PKT_INT,
4998 c->localid, PKT_END);
4999 logevent("Forwarded port opened successfully");
5006 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5008 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5009 unsigned int localid = ssh_pkt_getuint32(pktin);
5010 struct ssh_channel *c;
5012 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5013 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5014 c->remoteid = localid;
5015 c->halfopen = FALSE;
5016 c->type = CHAN_SOCKDATA;
5017 c->throttling_conn = 0;
5018 pfd_confirm(c->u.pfd.pf);
5021 if (c && c->pending_eof) {
5023 * We have a pending close on this channel,
5024 * which we decided on before the server acked
5025 * the channel open. So now we know the
5026 * remoteid, we can close it again.
5028 ssh_channel_try_eof(c);
5032 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5034 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5035 struct ssh_channel *c;
5037 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5038 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5039 logevent("Forwarded connection refused by server");
5040 pfd_close(c->u.pfd.pf);
5041 del234(ssh->channels, c);
5046 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5048 /* Remote side closes a channel. */
5049 unsigned i = ssh_pkt_getuint32(pktin);
5050 struct ssh_channel *c;
5051 c = find234(ssh->channels, &i, ssh_channelfind);
5052 if (c && !c->halfopen) {
5054 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5055 !(c->closes & CLOSES_RCVD_EOF)) {
5057 * Received CHANNEL_CLOSE, which we translate into
5060 int send_close = FALSE;
5062 c->closes |= CLOSES_RCVD_EOF;
5067 x11_send_eof(c->u.x11.xconn);
5073 pfd_send_eof(c->u.pfd.pf);
5082 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5083 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5085 c->closes |= CLOSES_SENT_EOF;
5089 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5090 !(c->closes & CLOSES_RCVD_CLOSE)) {
5092 if (!(c->closes & CLOSES_SENT_EOF)) {
5093 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5094 " for which we never sent CHANNEL_CLOSE\n", i));
5097 c->closes |= CLOSES_RCVD_CLOSE;
5100 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5101 !(c->closes & CLOSES_SENT_CLOSE)) {
5102 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5103 PKT_INT, c->remoteid, PKT_END);
5104 c->closes |= CLOSES_SENT_CLOSE;
5107 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5108 ssh_channel_destroy(c);
5110 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5111 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5112 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5117 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5119 /* Data sent down one of our channels. */
5120 int i = ssh_pkt_getuint32(pktin);
5123 struct ssh_channel *c;
5125 ssh_pkt_getstring(pktin, &p, &len);
5127 c = find234(ssh->channels, &i, ssh_channelfind);
5132 bufsize = x11_send(c->u.x11.xconn, p, len);
5135 bufsize = pfd_send(c->u.pfd.pf, p, len);
5138 /* Data for an agent message. Buffer it. */
5140 if (c->u.a.lensofar < 4) {
5141 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5142 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5146 c->u.a.lensofar += l;
5148 if (c->u.a.lensofar == 4) {
5150 4 + GET_32BIT(c->u.a.msglen);
5151 c->u.a.message = snewn(c->u.a.totallen,
5153 memcpy(c->u.a.message, c->u.a.msglen, 4);
5155 if (c->u.a.lensofar >= 4 && len > 0) {
5157 min(c->u.a.totallen - c->u.a.lensofar,
5159 memcpy(c->u.a.message + c->u.a.lensofar, p,
5163 c->u.a.lensofar += l;
5165 if (c->u.a.lensofar == c->u.a.totallen) {
5168 c->u.a.outstanding_requests++;
5169 if (agent_query(c->u.a.message,
5172 ssh_agentf_callback, c))
5173 ssh_agentf_callback(c, reply, replylen);
5174 sfree(c->u.a.message);
5175 c->u.a.lensofar = 0;
5178 bufsize = 0; /* agent channels never back up */
5181 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5182 c->throttling_conn = 1;
5183 ssh_throttle_conn(ssh, +1);
5188 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5190 ssh->exitcode = ssh_pkt_getuint32(pktin);
5191 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5192 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5194 * In case `helpful' firewalls or proxies tack
5195 * extra human-readable text on the end of the
5196 * session which we might mistake for another
5197 * encrypted packet, we close the session once
5198 * we've sent EXIT_CONFIRMATION.
5200 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5203 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5204 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5206 struct Packet *pktout = (struct Packet *)data;
5208 unsigned int arg = 0;
5209 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5210 if (i == lenof(ssh_ttymodes)) return;
5211 switch (ssh_ttymodes[i].type) {
5213 arg = ssh_tty_parse_specchar(val);
5216 arg = ssh_tty_parse_boolean(val);
5219 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5220 ssh2_pkt_addbyte(pktout, arg);
5224 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5225 struct Packet *pktin)
5227 crBegin(ssh->do_ssh1_connection_crstate);
5229 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5230 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5231 ssh1_smsg_stdout_stderr_data;
5233 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5234 ssh1_msg_channel_open_confirmation;
5235 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5236 ssh1_msg_channel_open_failure;
5237 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5238 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5239 ssh1_msg_channel_close;
5240 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5241 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5243 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5244 logevent("Requesting agent forwarding");
5245 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5249 if (pktin->type != SSH1_SMSG_SUCCESS
5250 && pktin->type != SSH1_SMSG_FAILURE) {
5251 bombout(("Protocol confusion"));
5253 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5254 logevent("Agent forwarding refused");
5256 logevent("Agent forwarding enabled");
5257 ssh->agentfwd_enabled = TRUE;
5258 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5262 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5263 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5264 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5265 logevent("Requesting X11 forwarding");
5266 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5267 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5268 PKT_STR, ssh->x11disp->remoteauthprotoname,
5269 PKT_STR, ssh->x11disp->remoteauthdatastring,
5270 PKT_INT, ssh->x11disp->screennum,
5273 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5274 PKT_STR, ssh->x11disp->remoteauthprotoname,
5275 PKT_STR, ssh->x11disp->remoteauthdatastring,
5281 if (pktin->type != SSH1_SMSG_SUCCESS
5282 && pktin->type != SSH1_SMSG_FAILURE) {
5283 bombout(("Protocol confusion"));
5285 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5286 logevent("X11 forwarding refused");
5288 logevent("X11 forwarding enabled");
5289 ssh->X11_fwd_enabled = TRUE;
5290 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5294 ssh_setup_portfwd(ssh, ssh->conf);
5295 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5297 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5299 /* Unpick the terminal-speed string. */
5300 /* XXX perhaps we should allow no speeds to be sent. */
5301 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5302 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5303 /* Send the pty request. */
5304 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5305 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5306 ssh_pkt_adduint32(pkt, ssh->term_height);
5307 ssh_pkt_adduint32(pkt, ssh->term_width);
5308 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5309 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5310 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5311 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5312 ssh_pkt_adduint32(pkt, ssh->ispeed);
5313 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5314 ssh_pkt_adduint32(pkt, ssh->ospeed);
5315 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5317 ssh->state = SSH_STATE_INTERMED;
5321 if (pktin->type != SSH1_SMSG_SUCCESS
5322 && pktin->type != SSH1_SMSG_FAILURE) {
5323 bombout(("Protocol confusion"));
5325 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5326 c_write_str(ssh, "Server refused to allocate pty\r\n");
5327 ssh->editing = ssh->echoing = 1;
5329 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5330 ssh->ospeed, ssh->ispeed);
5331 ssh->got_pty = TRUE;
5334 ssh->editing = ssh->echoing = 1;
5337 if (conf_get_int(ssh->conf, CONF_compression)) {
5338 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5342 if (pktin->type != SSH1_SMSG_SUCCESS
5343 && pktin->type != SSH1_SMSG_FAILURE) {
5344 bombout(("Protocol confusion"));
5346 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5347 c_write_str(ssh, "Server refused to compress\r\n");
5349 logevent("Started compression");
5350 ssh->v1_compressing = TRUE;
5351 ssh->cs_comp_ctx = zlib_compress_init();
5352 logevent("Initialised zlib (RFC1950) compression");
5353 ssh->sc_comp_ctx = zlib_decompress_init();
5354 logevent("Initialised zlib (RFC1950) decompression");
5358 * Start the shell or command.
5360 * Special case: if the first-choice command is an SSH-2
5361 * subsystem (hence not usable here) and the second choice
5362 * exists, we fall straight back to that.
5365 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5367 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5368 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5369 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5370 ssh->fallback_cmd = TRUE;
5373 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5375 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5376 logevent("Started session");
5379 ssh->state = SSH_STATE_SESSION;
5380 if (ssh->size_needed)
5381 ssh_size(ssh, ssh->term_width, ssh->term_height);
5382 if (ssh->eof_needed)
5383 ssh_special(ssh, TS_EOF);
5386 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5388 ssh->channels = newtree234(ssh_channelcmp);
5392 * By this point, most incoming packets are already being
5393 * handled by the dispatch table, and we need only pay
5394 * attention to the unusual ones.
5399 if (pktin->type == SSH1_SMSG_SUCCESS) {
5400 /* may be from EXEC_SHELL on some servers */
5401 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5402 /* may be from EXEC_SHELL on some servers
5403 * if no pty is available or in other odd cases. Ignore */
5405 bombout(("Strange packet received: type %d", pktin->type));
5410 int len = min(inlen, 512);
5411 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5412 PKT_INT, len, PKT_DATA, in, len,
5424 * Handle the top-level SSH-2 protocol.
5426 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5431 ssh_pkt_getstring(pktin, &msg, &msglen);
5432 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5435 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5437 /* log reason code in disconnect message */
5441 ssh_pkt_getstring(pktin, &msg, &msglen);
5442 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5445 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5447 /* Do nothing, because we're ignoring it! Duhh. */
5450 static void ssh1_protocol_setup(Ssh ssh)
5455 * Most messages are handled by the coroutines.
5457 for (i = 0; i < 256; i++)
5458 ssh->packet_dispatch[i] = NULL;
5461 * These special message types we install handlers for.
5463 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5464 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5465 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5468 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5469 struct Packet *pktin)
5471 unsigned char *in=(unsigned char*)vin;
5472 if (ssh->state == SSH_STATE_CLOSED)
5475 if (pktin && ssh->packet_dispatch[pktin->type]) {
5476 ssh->packet_dispatch[pktin->type](ssh, pktin);
5480 if (!ssh->protocol_initial_phase_done) {
5481 if (do_ssh1_login(ssh, in, inlen, pktin))
5482 ssh->protocol_initial_phase_done = TRUE;
5487 do_ssh1_connection(ssh, in, inlen, pktin);
5491 * Utility routine for decoding comma-separated strings in KEXINIT.
5493 static int in_commasep_string(char *needle, char *haystack, int haylen)
5496 if (!needle || !haystack) /* protect against null pointers */
5498 needlen = strlen(needle);
5501 * Is it at the start of the string?
5503 if (haylen >= needlen && /* haystack is long enough */
5504 !memcmp(needle, haystack, needlen) && /* initial match */
5505 (haylen == needlen || haystack[needlen] == ',')
5506 /* either , or EOS follows */
5510 * If not, search for the next comma and resume after that.
5511 * If no comma found, terminate.
5513 while (haylen > 0 && *haystack != ',')
5514 haylen--, haystack++;
5517 haylen--, haystack++; /* skip over comma itself */
5522 * Similar routine for checking whether we have the first string in a list.
5524 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5527 if (!needle || !haystack) /* protect against null pointers */
5529 needlen = strlen(needle);
5531 * Is it at the start of the string?
5533 if (haylen >= needlen && /* haystack is long enough */
5534 !memcmp(needle, haystack, needlen) && /* initial match */
5535 (haylen == needlen || haystack[needlen] == ',')
5536 /* either , or EOS follows */
5544 * SSH-2 key creation method.
5545 * (Currently assumes 2 lots of any hash are sufficient to generate
5546 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5548 #define SSH2_MKKEY_ITERS (2)
5549 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5550 unsigned char *keyspace)
5552 const struct ssh_hash *h = ssh->kex->hash;
5554 /* First hlen bytes. */
5556 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5557 hash_mpint(h, s, K);
5558 h->bytes(s, H, h->hlen);
5559 h->bytes(s, &chr, 1);
5560 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5561 h->final(s, keyspace);
5562 /* Next hlen bytes. */
5564 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5565 hash_mpint(h, s, K);
5566 h->bytes(s, H, h->hlen);
5567 h->bytes(s, keyspace, h->hlen);
5568 h->final(s, keyspace + h->hlen);
5572 * Handle the SSH-2 transport layer.
5574 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5575 struct Packet *pktin)
5577 unsigned char *in = (unsigned char *)vin;
5578 struct do_ssh2_transport_state {
5580 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5581 Bignum p, g, e, f, K;
5584 int kex_init_value, kex_reply_value;
5585 const struct ssh_mac **maclist;
5587 const struct ssh2_cipher *cscipher_tobe;
5588 const struct ssh2_cipher *sccipher_tobe;
5589 const struct ssh_mac *csmac_tobe;
5590 const struct ssh_mac *scmac_tobe;
5591 const struct ssh_compress *cscomp_tobe;
5592 const struct ssh_compress *sccomp_tobe;
5593 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5594 int hostkeylen, siglen, rsakeylen;
5595 void *hkey; /* actual host key */
5596 void *rsakey; /* for RSA kex */
5597 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5598 int n_preferred_kex;
5599 const struct ssh_kexes *preferred_kex[KEX_MAX];
5600 int n_preferred_ciphers;
5601 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5602 const struct ssh_compress *preferred_comp;
5603 int userauth_succeeded; /* for delayed compression */
5604 int pending_compression;
5605 int got_session_id, activated_authconn;
5606 struct Packet *pktout;
5611 crState(do_ssh2_transport_state);
5615 s->cscipher_tobe = s->sccipher_tobe = NULL;
5616 s->csmac_tobe = s->scmac_tobe = NULL;
5617 s->cscomp_tobe = s->sccomp_tobe = NULL;
5619 s->got_session_id = s->activated_authconn = FALSE;
5620 s->userauth_succeeded = FALSE;
5621 s->pending_compression = FALSE;
5624 * Be prepared to work around the buggy MAC problem.
5626 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5627 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5629 s->maclist = macs, s->nmacs = lenof(macs);
5632 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5634 int i, j, k, commalist_started;
5637 * Set up the preferred key exchange. (NULL => warn below here)
5639 s->n_preferred_kex = 0;
5640 for (i = 0; i < KEX_MAX; i++) {
5641 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5643 s->preferred_kex[s->n_preferred_kex++] =
5644 &ssh_diffiehellman_gex;
5647 s->preferred_kex[s->n_preferred_kex++] =
5648 &ssh_diffiehellman_group14;
5651 s->preferred_kex[s->n_preferred_kex++] =
5652 &ssh_diffiehellman_group1;
5655 s->preferred_kex[s->n_preferred_kex++] =
5659 /* Flag for later. Don't bother if it's the last in
5661 if (i < KEX_MAX - 1) {
5662 s->preferred_kex[s->n_preferred_kex++] = NULL;
5669 * Set up the preferred ciphers. (NULL => warn below here)
5671 s->n_preferred_ciphers = 0;
5672 for (i = 0; i < CIPHER_MAX; i++) {
5673 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5674 case CIPHER_BLOWFISH:
5675 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5678 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5679 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5683 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5686 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5688 case CIPHER_ARCFOUR:
5689 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5692 /* Flag for later. Don't bother if it's the last in
5694 if (i < CIPHER_MAX - 1) {
5695 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5702 * Set up preferred compression.
5704 if (conf_get_int(ssh->conf, CONF_compression))
5705 s->preferred_comp = &ssh_zlib;
5707 s->preferred_comp = &ssh_comp_none;
5710 * Enable queueing of outgoing auth- or connection-layer
5711 * packets while we are in the middle of a key exchange.
5713 ssh->queueing = TRUE;
5716 * Flag that KEX is in progress.
5718 ssh->kex_in_progress = TRUE;
5721 * Construct and send our key exchange packet.
5723 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5724 for (i = 0; i < 16; i++)
5725 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5726 /* List key exchange algorithms. */
5727 ssh2_pkt_addstring_start(s->pktout);
5728 commalist_started = 0;
5729 for (i = 0; i < s->n_preferred_kex; i++) {
5730 const struct ssh_kexes *k = s->preferred_kex[i];
5731 if (!k) continue; /* warning flag */
5732 for (j = 0; j < k->nkexes; j++) {
5733 if (commalist_started)
5734 ssh2_pkt_addstring_str(s->pktout, ",");
5735 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5736 commalist_started = 1;
5739 /* List server host key algorithms. */
5740 if (!s->got_session_id) {
5742 * In the first key exchange, we list all the algorithms
5743 * we're prepared to cope with.
5745 ssh2_pkt_addstring_start(s->pktout);
5746 for (i = 0; i < lenof(hostkey_algs); i++) {
5747 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5748 if (i < lenof(hostkey_algs) - 1)
5749 ssh2_pkt_addstring_str(s->pktout, ",");
5753 * In subsequent key exchanges, we list only the kex
5754 * algorithm that was selected in the first key exchange,
5755 * so that we keep getting the same host key and hence
5756 * don't have to interrupt the user's session to ask for
5760 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5762 /* List encryption algorithms (client->server then server->client). */
5763 for (k = 0; k < 2; k++) {
5764 ssh2_pkt_addstring_start(s->pktout);
5765 commalist_started = 0;
5766 for (i = 0; i < s->n_preferred_ciphers; i++) {
5767 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5768 if (!c) continue; /* warning flag */
5769 for (j = 0; j < c->nciphers; j++) {
5770 if (commalist_started)
5771 ssh2_pkt_addstring_str(s->pktout, ",");
5772 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5773 commalist_started = 1;
5777 /* List MAC algorithms (client->server then server->client). */
5778 for (j = 0; j < 2; j++) {
5779 ssh2_pkt_addstring_start(s->pktout);
5780 for (i = 0; i < s->nmacs; i++) {
5781 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5782 if (i < s->nmacs - 1)
5783 ssh2_pkt_addstring_str(s->pktout, ",");
5786 /* List client->server compression algorithms,
5787 * then server->client compression algorithms. (We use the
5788 * same set twice.) */
5789 for (j = 0; j < 2; j++) {
5790 ssh2_pkt_addstring_start(s->pktout);
5791 assert(lenof(compressions) > 1);
5792 /* Prefer non-delayed versions */
5793 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5794 /* We don't even list delayed versions of algorithms until
5795 * they're allowed to be used, to avoid a race. See the end of
5797 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5798 ssh2_pkt_addstring_str(s->pktout, ",");
5799 ssh2_pkt_addstring_str(s->pktout,
5800 s->preferred_comp->delayed_name);
5802 for (i = 0; i < lenof(compressions); i++) {
5803 const struct ssh_compress *c = compressions[i];
5804 if (c != s->preferred_comp) {
5805 ssh2_pkt_addstring_str(s->pktout, ",");
5806 ssh2_pkt_addstring_str(s->pktout, c->name);
5807 if (s->userauth_succeeded && c->delayed_name) {
5808 ssh2_pkt_addstring_str(s->pktout, ",");
5809 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5814 /* List client->server languages. Empty list. */
5815 ssh2_pkt_addstring_start(s->pktout);
5816 /* List server->client languages. Empty list. */
5817 ssh2_pkt_addstring_start(s->pktout);
5818 /* First KEX packet does _not_ follow, because we're not that brave. */
5819 ssh2_pkt_addbool(s->pktout, FALSE);
5821 ssh2_pkt_adduint32(s->pktout, 0);
5824 s->our_kexinitlen = s->pktout->length - 5;
5825 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5826 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5828 ssh2_pkt_send_noqueue(ssh, s->pktout);
5831 crWaitUntilV(pktin);
5834 * Now examine the other side's KEXINIT to see what we're up
5838 char *str, *preferred;
5841 if (pktin->type != SSH2_MSG_KEXINIT) {
5842 bombout(("expected key exchange packet from server"));
5846 ssh->hostkey = NULL;
5847 s->cscipher_tobe = NULL;
5848 s->sccipher_tobe = NULL;
5849 s->csmac_tobe = NULL;
5850 s->scmac_tobe = NULL;
5851 s->cscomp_tobe = NULL;
5852 s->sccomp_tobe = NULL;
5853 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5855 pktin->savedpos += 16; /* skip garbage cookie */
5856 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5859 for (i = 0; i < s->n_preferred_kex; i++) {
5860 const struct ssh_kexes *k = s->preferred_kex[i];
5864 for (j = 0; j < k->nkexes; j++) {
5865 if (!preferred) preferred = k->list[j]->name;
5866 if (in_commasep_string(k->list[j]->name, str, len)) {
5867 ssh->kex = k->list[j];
5876 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5877 str ? str : "(null)"));
5881 * Note that the server's guess is considered wrong if it doesn't match
5882 * the first algorithm in our list, even if it's still the algorithm
5885 s->guessok = first_in_commasep_string(preferred, str, len);
5886 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5887 for (i = 0; i < lenof(hostkey_algs); i++) {
5888 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5889 ssh->hostkey = hostkey_algs[i];
5893 if (!ssh->hostkey) {
5894 bombout(("Couldn't agree a host key algorithm (available: %s)",
5895 str ? str : "(null)"));
5899 s->guessok = s->guessok &&
5900 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5901 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5902 for (i = 0; i < s->n_preferred_ciphers; i++) {
5903 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5905 s->warn_cscipher = TRUE;
5907 for (j = 0; j < c->nciphers; j++) {
5908 if (in_commasep_string(c->list[j]->name, str, len)) {
5909 s->cscipher_tobe = c->list[j];
5914 if (s->cscipher_tobe)
5917 if (!s->cscipher_tobe) {
5918 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5919 str ? str : "(null)"));
5923 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5924 for (i = 0; i < s->n_preferred_ciphers; i++) {
5925 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5927 s->warn_sccipher = TRUE;
5929 for (j = 0; j < c->nciphers; j++) {
5930 if (in_commasep_string(c->list[j]->name, str, len)) {
5931 s->sccipher_tobe = c->list[j];
5936 if (s->sccipher_tobe)
5939 if (!s->sccipher_tobe) {
5940 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5941 str ? str : "(null)"));
5945 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5946 for (i = 0; i < s->nmacs; i++) {
5947 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5948 s->csmac_tobe = s->maclist[i];
5952 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5953 for (i = 0; i < s->nmacs; i++) {
5954 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5955 s->scmac_tobe = s->maclist[i];
5959 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5960 for (i = 0; i < lenof(compressions) + 1; i++) {
5961 const struct ssh_compress *c =
5962 i == 0 ? s->preferred_comp : compressions[i - 1];
5963 if (in_commasep_string(c->name, str, len)) {
5966 } else if (in_commasep_string(c->delayed_name, str, len)) {
5967 if (s->userauth_succeeded) {
5971 s->pending_compression = TRUE; /* try this later */
5975 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5976 for (i = 0; i < lenof(compressions) + 1; i++) {
5977 const struct ssh_compress *c =
5978 i == 0 ? s->preferred_comp : compressions[i - 1];
5979 if (in_commasep_string(c->name, str, len)) {
5982 } else if (in_commasep_string(c->delayed_name, str, len)) {
5983 if (s->userauth_succeeded) {
5987 s->pending_compression = TRUE; /* try this later */
5991 if (s->pending_compression) {
5992 logevent("Server supports delayed compression; "
5993 "will try this later");
5995 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5996 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5997 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5999 ssh->exhash = ssh->kex->hash->init();
6000 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6001 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6002 hash_string(ssh->kex->hash, ssh->exhash,
6003 s->our_kexinit, s->our_kexinitlen);
6004 sfree(s->our_kexinit);
6005 /* Include the type byte in the hash of server's KEXINIT */
6006 hash_string(ssh->kex->hash, ssh->exhash,
6007 pktin->body - 1, pktin->length + 1);
6010 ssh_set_frozen(ssh, 1);
6011 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6013 ssh_dialog_callback, ssh);
6014 if (s->dlgret < 0) {
6018 bombout(("Unexpected data from server while"
6019 " waiting for user response"));
6022 } while (pktin || inlen > 0);
6023 s->dlgret = ssh->user_response;
6025 ssh_set_frozen(ssh, 0);
6026 if (s->dlgret == 0) {
6027 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6033 if (s->warn_cscipher) {
6034 ssh_set_frozen(ssh, 1);
6035 s->dlgret = askalg(ssh->frontend,
6036 "client-to-server cipher",
6037 s->cscipher_tobe->name,
6038 ssh_dialog_callback, ssh);
6039 if (s->dlgret < 0) {
6043 bombout(("Unexpected data from server while"
6044 " waiting for user response"));
6047 } while (pktin || inlen > 0);
6048 s->dlgret = ssh->user_response;
6050 ssh_set_frozen(ssh, 0);
6051 if (s->dlgret == 0) {
6052 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6058 if (s->warn_sccipher) {
6059 ssh_set_frozen(ssh, 1);
6060 s->dlgret = askalg(ssh->frontend,
6061 "server-to-client cipher",
6062 s->sccipher_tobe->name,
6063 ssh_dialog_callback, ssh);
6064 if (s->dlgret < 0) {
6068 bombout(("Unexpected data from server while"
6069 " waiting for user response"));
6072 } while (pktin || inlen > 0);
6073 s->dlgret = ssh->user_response;
6075 ssh_set_frozen(ssh, 0);
6076 if (s->dlgret == 0) {
6077 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6083 if (s->ignorepkt) /* first_kex_packet_follows */
6084 crWaitUntilV(pktin); /* Ignore packet */
6087 if (ssh->kex->main_type == KEXTYPE_DH) {
6089 * Work out the number of bits of key we will need from the
6090 * key exchange. We start with the maximum key length of
6096 csbits = s->cscipher_tobe->keylen;
6097 scbits = s->sccipher_tobe->keylen;
6098 s->nbits = (csbits > scbits ? csbits : scbits);
6100 /* The keys only have hlen-bit entropy, since they're based on
6101 * a hash. So cap the key size at hlen bits. */
6102 if (s->nbits > ssh->kex->hash->hlen * 8)
6103 s->nbits = ssh->kex->hash->hlen * 8;
6106 * If we're doing Diffie-Hellman group exchange, start by
6107 * requesting a group.
6109 if (!ssh->kex->pdata) {
6110 logevent("Doing Diffie-Hellman group exchange");
6111 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6113 * Work out how big a DH group we will need to allow that
6116 s->pbits = 512 << ((s->nbits - 1) / 64);
6117 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6118 ssh2_pkt_adduint32(s->pktout, s->pbits);
6119 ssh2_pkt_send_noqueue(ssh, s->pktout);
6121 crWaitUntilV(pktin);
6122 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6123 bombout(("expected key exchange group packet from server"));
6126 s->p = ssh2_pkt_getmp(pktin);
6127 s->g = ssh2_pkt_getmp(pktin);
6128 if (!s->p || !s->g) {
6129 bombout(("unable to read mp-ints from incoming group packet"));
6132 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6133 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6134 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6136 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6137 ssh->kex_ctx = dh_setup_group(ssh->kex);
6138 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6139 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6140 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6141 ssh->kex->groupname);
6144 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6145 ssh->kex->hash->text_name);
6147 * Now generate and send e for Diffie-Hellman.
6149 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6150 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6151 s->pktout = ssh2_pkt_init(s->kex_init_value);
6152 ssh2_pkt_addmp(s->pktout, s->e);
6153 ssh2_pkt_send_noqueue(ssh, s->pktout);
6155 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6156 crWaitUntilV(pktin);
6157 if (pktin->type != s->kex_reply_value) {
6158 bombout(("expected key exchange reply packet from server"));
6161 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6162 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6163 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6164 s->f = ssh2_pkt_getmp(pktin);
6166 bombout(("unable to parse key exchange reply packet"));
6169 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6171 s->K = dh_find_K(ssh->kex_ctx, s->f);
6173 /* We assume everything from now on will be quick, and it might
6174 * involve user interaction. */
6175 set_busy_status(ssh->frontend, BUSY_NOT);
6177 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6178 if (!ssh->kex->pdata) {
6179 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6180 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6181 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6183 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6184 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6186 dh_cleanup(ssh->kex_ctx);
6188 if (!ssh->kex->pdata) {
6193 logeventf(ssh, "Doing RSA key exchange with hash %s",
6194 ssh->kex->hash->text_name);
6195 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6197 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6200 crWaitUntilV(pktin);
6201 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6202 bombout(("expected RSA public key packet from server"));
6206 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6207 hash_string(ssh->kex->hash, ssh->exhash,
6208 s->hostkeydata, s->hostkeylen);
6209 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6213 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6214 s->rsakeydata = snewn(s->rsakeylen, char);
6215 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6218 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6220 sfree(s->rsakeydata);
6221 bombout(("unable to parse RSA public key from server"));
6225 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6228 * Next, set up a shared secret K, of precisely KLEN -
6229 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6230 * RSA key modulus and HLEN is the bit length of the hash
6234 int klen = ssh_rsakex_klen(s->rsakey);
6235 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6237 unsigned char *kstr1, *kstr2, *outstr;
6238 int kstr1len, kstr2len, outstrlen;
6240 s->K = bn_power_2(nbits - 1);
6242 for (i = 0; i < nbits; i++) {
6244 byte = random_byte();
6246 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6250 * Encode this as an mpint.
6252 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6253 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6254 PUT_32BIT(kstr2, kstr1len);
6255 memcpy(kstr2 + 4, kstr1, kstr1len);
6258 * Encrypt it with the given RSA key.
6260 outstrlen = (klen + 7) / 8;
6261 outstr = snewn(outstrlen, unsigned char);
6262 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6263 outstr, outstrlen, s->rsakey);
6266 * And send it off in a return packet.
6268 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6269 ssh2_pkt_addstring_start(s->pktout);
6270 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6271 ssh2_pkt_send_noqueue(ssh, s->pktout);
6273 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6280 ssh_rsakex_freekey(s->rsakey);
6282 crWaitUntilV(pktin);
6283 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6284 sfree(s->rsakeydata);
6285 bombout(("expected signature packet from server"));
6289 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6291 sfree(s->rsakeydata);
6294 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6295 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6296 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6298 ssh->kex_ctx = NULL;
6301 debug(("Exchange hash is:\n"));
6302 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6306 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6307 (char *)s->exchange_hash,
6308 ssh->kex->hash->hlen)) {
6309 bombout(("Server's host key did not match the signature supplied"));
6313 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6314 if (!s->got_session_id) {
6316 * Authenticate remote host: verify host key. (We've already
6317 * checked the signature of the exchange hash.)
6319 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6320 ssh_set_frozen(ssh, 1);
6321 s->dlgret = verify_ssh_host_key(ssh->frontend,
6322 ssh->savedhost, ssh->savedport,
6323 ssh->hostkey->keytype, s->keystr,
6325 ssh_dialog_callback, ssh);
6326 if (s->dlgret < 0) {
6330 bombout(("Unexpected data from server while waiting"
6331 " for user host key response"));
6334 } while (pktin || inlen > 0);
6335 s->dlgret = ssh->user_response;
6337 ssh_set_frozen(ssh, 0);
6338 if (s->dlgret == 0) {
6339 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6343 logevent("Host key fingerprint is:");
6344 logevent(s->fingerprint);
6345 sfree(s->fingerprint);
6347 * Save this host key, to check against the one presented in
6348 * subsequent rekeys.
6350 ssh->hostkey_str = s->keystr;
6353 * In a rekey, we never present an interactive host key
6354 * verification request to the user. Instead, we simply
6355 * enforce that the key we're seeing this time is identical to
6356 * the one we saw before.
6358 if (strcmp(ssh->hostkey_str, s->keystr)) {
6359 bombout(("Host key was different in repeat key exchange"));
6364 ssh->hostkey->freekey(s->hkey);
6367 * The exchange hash from the very first key exchange is also
6368 * the session id, used in session key construction and
6371 if (!s->got_session_id) {
6372 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6373 memcpy(ssh->v2_session_id, s->exchange_hash,
6374 sizeof(s->exchange_hash));
6375 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6376 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6377 s->got_session_id = TRUE;
6381 * Send SSH2_MSG_NEWKEYS.
6383 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6384 ssh2_pkt_send_noqueue(ssh, s->pktout);
6385 ssh->outgoing_data_size = 0; /* start counting from here */
6388 * We've sent client NEWKEYS, so create and initialise
6389 * client-to-server session keys.
6391 if (ssh->cs_cipher_ctx)
6392 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6393 ssh->cscipher = s->cscipher_tobe;
6394 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6396 if (ssh->cs_mac_ctx)
6397 ssh->csmac->free_context(ssh->cs_mac_ctx);
6398 ssh->csmac = s->csmac_tobe;
6399 ssh->cs_mac_ctx = ssh->csmac->make_context();
6401 if (ssh->cs_comp_ctx)
6402 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6403 ssh->cscomp = s->cscomp_tobe;
6404 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6407 * Set IVs on client-to-server keys. Here we use the exchange
6408 * hash from the _first_ key exchange.
6411 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6412 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6413 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6414 assert((ssh->cscipher->keylen+7) / 8 <=
6415 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6416 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6417 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6418 assert(ssh->cscipher->blksize <=
6419 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6420 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6421 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6422 assert(ssh->csmac->len <=
6423 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6424 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6425 smemclr(keyspace, sizeof(keyspace));
6428 logeventf(ssh, "Initialised %.200s client->server encryption",
6429 ssh->cscipher->text_name);
6430 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6431 ssh->csmac->text_name);
6432 if (ssh->cscomp->text_name)
6433 logeventf(ssh, "Initialised %s compression",
6434 ssh->cscomp->text_name);
6437 * Now our end of the key exchange is complete, we can send all
6438 * our queued higher-layer packets.
6440 ssh->queueing = FALSE;
6441 ssh2_pkt_queuesend(ssh);
6444 * Expect SSH2_MSG_NEWKEYS from server.
6446 crWaitUntilV(pktin);
6447 if (pktin->type != SSH2_MSG_NEWKEYS) {
6448 bombout(("expected new-keys packet from server"));
6451 ssh->incoming_data_size = 0; /* start counting from here */
6454 * We've seen server NEWKEYS, so create and initialise
6455 * server-to-client session keys.
6457 if (ssh->sc_cipher_ctx)
6458 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6459 ssh->sccipher = s->sccipher_tobe;
6460 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6462 if (ssh->sc_mac_ctx)
6463 ssh->scmac->free_context(ssh->sc_mac_ctx);
6464 ssh->scmac = s->scmac_tobe;
6465 ssh->sc_mac_ctx = ssh->scmac->make_context();
6467 if (ssh->sc_comp_ctx)
6468 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6469 ssh->sccomp = s->sccomp_tobe;
6470 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6473 * Set IVs on server-to-client keys. Here we use the exchange
6474 * hash from the _first_ key exchange.
6477 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6478 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6479 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6480 assert((ssh->sccipher->keylen+7) / 8 <=
6481 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6482 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6483 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6484 assert(ssh->sccipher->blksize <=
6485 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6486 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6487 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6488 assert(ssh->scmac->len <=
6489 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6490 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6491 smemclr(keyspace, sizeof(keyspace));
6493 logeventf(ssh, "Initialised %.200s server->client encryption",
6494 ssh->sccipher->text_name);
6495 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6496 ssh->scmac->text_name);
6497 if (ssh->sccomp->text_name)
6498 logeventf(ssh, "Initialised %s decompression",
6499 ssh->sccomp->text_name);
6502 * Free shared secret.
6507 * Key exchange is over. Loop straight back round if we have a
6508 * deferred rekey reason.
6510 if (ssh->deferred_rekey_reason) {
6511 logevent(ssh->deferred_rekey_reason);
6513 ssh->deferred_rekey_reason = NULL;
6514 goto begin_key_exchange;
6518 * Otherwise, schedule a timer for our next rekey.
6520 ssh->kex_in_progress = FALSE;
6521 ssh->last_rekey = GETTICKCOUNT();
6522 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6523 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6527 * Now we're encrypting. Begin returning 1 to the protocol main
6528 * function so that other things can run on top of the
6529 * transport. If we ever see a KEXINIT, we must go back to the
6532 * We _also_ go back to the start if we see pktin==NULL and
6533 * inlen negative, because this is a special signal meaning
6534 * `initiate client-driven rekey', and `in' contains a message
6535 * giving the reason for the rekey.
6537 * inlen==-1 means always initiate a rekey;
6538 * inlen==-2 means that userauth has completed successfully and
6539 * we should consider rekeying (for delayed compression).
6541 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6542 (!pktin && inlen < 0))) {
6544 if (!ssh->protocol_initial_phase_done) {
6545 ssh->protocol_initial_phase_done = TRUE;
6547 * Allow authconn to initialise itself.
6549 do_ssh2_authconn(ssh, NULL, 0, NULL);
6554 logevent("Server initiated key re-exchange");
6558 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6559 * delayed compression, if it's available.
6561 * draft-miller-secsh-compression-delayed-00 says that you
6562 * negotiate delayed compression in the first key exchange, and
6563 * both sides start compressing when the server has sent
6564 * USERAUTH_SUCCESS. This has a race condition -- the server
6565 * can't know when the client has seen it, and thus which incoming
6566 * packets it should treat as compressed.
6568 * Instead, we do the initial key exchange without offering the
6569 * delayed methods, but note if the server offers them; when we
6570 * get here, if a delayed method was available that was higher
6571 * on our list than what we got, we initiate a rekey in which we
6572 * _do_ list the delayed methods (and hopefully get it as a
6573 * result). Subsequent rekeys will do the same.
6575 assert(!s->userauth_succeeded); /* should only happen once */
6576 s->userauth_succeeded = TRUE;
6577 if (!s->pending_compression)
6578 /* Can't see any point rekeying. */
6579 goto wait_for_rekey; /* this is utterly horrid */
6580 /* else fall through to rekey... */
6581 s->pending_compression = FALSE;
6584 * Now we've decided to rekey.
6586 * Special case: if the server bug is set that doesn't
6587 * allow rekeying, we give a different log message and
6588 * continue waiting. (If such a server _initiates_ a rekey,
6589 * we process it anyway!)
6591 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6592 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6594 /* Reset the counters, so that at least this message doesn't
6595 * hit the event log _too_ often. */
6596 ssh->outgoing_data_size = 0;
6597 ssh->incoming_data_size = 0;
6598 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6600 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6603 goto wait_for_rekey; /* this is still utterly horrid */
6605 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6608 goto begin_key_exchange;
6614 * Add data to an SSH-2 channel output buffer.
6616 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6619 bufchain_add(&c->v.v2.outbuffer, buf, len);
6623 * Attempt to send data on an SSH-2 channel.
6625 static int ssh2_try_send(struct ssh_channel *c)
6628 struct Packet *pktout;
6631 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6634 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6635 if ((unsigned)len > c->v.v2.remwindow)
6636 len = c->v.v2.remwindow;
6637 if ((unsigned)len > c->v.v2.remmaxpkt)
6638 len = c->v.v2.remmaxpkt;
6639 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6640 ssh2_pkt_adduint32(pktout, c->remoteid);
6641 ssh2_pkt_addstring_start(pktout);
6642 ssh2_pkt_addstring_data(pktout, data, len);
6643 ssh2_pkt_send(ssh, pktout);
6644 bufchain_consume(&c->v.v2.outbuffer, len);
6645 c->v.v2.remwindow -= len;
6649 * After having sent as much data as we can, return the amount
6652 ret = bufchain_size(&c->v.v2.outbuffer);
6655 * And if there's no data pending but we need to send an EOF, send
6658 if (!ret && c->pending_eof)
6659 ssh_channel_try_eof(c);
6664 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6667 if (c->closes & CLOSES_SENT_EOF)
6668 return; /* don't send on channels we've EOFed */
6669 bufsize = ssh2_try_send(c);
6672 case CHAN_MAINSESSION:
6673 /* stdin need not receive an unthrottle
6674 * notification since it will be polled */
6677 x11_unthrottle(c->u.x11.xconn);
6680 /* agent sockets are request/response and need no
6681 * buffer management */
6684 pfd_unthrottle(c->u.pfd.pf);
6691 * Set up most of a new ssh_channel for SSH-2.
6693 static void ssh2_channel_init(struct ssh_channel *c)
6696 c->localid = alloc_channel_id(ssh);
6698 c->pending_eof = FALSE;
6699 c->throttling_conn = FALSE;
6700 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6701 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6702 c->v.v2.chanreq_head = NULL;
6703 c->v.v2.throttle_state = UNTHROTTLED;
6704 bufchain_init(&c->v.v2.outbuffer);
6708 * Construct the common parts of a CHANNEL_OPEN.
6710 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6712 struct Packet *pktout;
6714 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6715 ssh2_pkt_addstring(pktout, type);
6716 ssh2_pkt_adduint32(pktout, c->localid);
6717 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6718 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6723 * CHANNEL_FAILURE doesn't come with any indication of what message
6724 * caused it, so we have to keep track of the outstanding
6725 * CHANNEL_REQUESTs ourselves.
6727 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6728 cchandler_fn_t handler, void *ctx)
6730 struct outstanding_channel_request *ocr =
6731 snew(struct outstanding_channel_request);
6733 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6734 ocr->handler = handler;
6737 if (!c->v.v2.chanreq_head)
6738 c->v.v2.chanreq_head = ocr;
6740 c->v.v2.chanreq_tail->next = ocr;
6741 c->v.v2.chanreq_tail = ocr;
6745 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6746 * NULL then a reply will be requested and the handler will be called
6747 * when it arrives. The returned packet is ready to have any
6748 * request-specific data added and be sent. Note that if a handler is
6749 * provided, it's essential that the request actually be sent.
6751 * The handler will usually be passed the response packet in pktin.
6752 * If pktin is NULL, this means that no reply will ever be forthcoming
6753 * (e.g. because the entire connection is being destroyed) and the
6754 * handler should free any storage it's holding.
6756 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6757 cchandler_fn_t handler, void *ctx)
6759 struct Packet *pktout;
6761 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6762 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6763 ssh2_pkt_adduint32(pktout, c->remoteid);
6764 ssh2_pkt_addstring(pktout, type);
6765 ssh2_pkt_addbool(pktout, handler != NULL);
6766 if (handler != NULL)
6767 ssh2_queue_chanreq_handler(c, handler, ctx);
6772 * Potentially enlarge the window on an SSH-2 channel.
6774 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6776 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6781 * Never send WINDOW_ADJUST for a channel that the remote side has
6782 * already sent EOF on; there's no point, since it won't be
6783 * sending any more data anyway. Ditto if _we've_ already sent
6786 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6790 * If the remote end has a habit of ignoring maxpkt, limit the
6791 * window so that it has no choice (assuming it doesn't ignore the
6794 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6795 newwin = OUR_V2_MAXPKT;
6798 * Only send a WINDOW_ADJUST if there's significantly more window
6799 * available than the other end thinks there is. This saves us
6800 * sending a WINDOW_ADJUST for every character in a shell session.
6802 * "Significant" is arbitrarily defined as half the window size.
6804 if (newwin / 2 >= c->v.v2.locwindow) {
6805 struct Packet *pktout;
6809 * In order to keep track of how much window the client
6810 * actually has available, we'd like it to acknowledge each
6811 * WINDOW_ADJUST. We can't do that directly, so we accompany
6812 * it with a CHANNEL_REQUEST that has to be acknowledged.
6814 * This is only necessary if we're opening the window wide.
6815 * If we're not, then throughput is being constrained by
6816 * something other than the maximum window size anyway.
6818 if (newwin == c->v.v2.locmaxwin &&
6819 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6820 up = snew(unsigned);
6821 *up = newwin - c->v.v2.locwindow;
6822 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6823 ssh2_handle_winadj_response, up);
6824 ssh2_pkt_send(ssh, pktout);
6826 if (c->v.v2.throttle_state != UNTHROTTLED)
6827 c->v.v2.throttle_state = UNTHROTTLING;
6829 /* Pretend the WINDOW_ADJUST was acked immediately. */
6830 c->v.v2.remlocwin = newwin;
6831 c->v.v2.throttle_state = THROTTLED;
6833 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6834 ssh2_pkt_adduint32(pktout, c->remoteid);
6835 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6836 ssh2_pkt_send(ssh, pktout);
6837 c->v.v2.locwindow = newwin;
6842 * Find the channel associated with a message. If there's no channel,
6843 * or it's not properly open, make a noise about it and return NULL.
6845 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6847 unsigned localid = ssh_pkt_getuint32(pktin);
6848 struct ssh_channel *c;
6850 c = find234(ssh->channels, &localid, ssh_channelfind);
6852 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6853 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6854 char *buf = dupprintf("Received %s for %s channel %u",
6855 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6857 c ? "half-open" : "nonexistent", localid);
6858 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6865 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6866 struct Packet *pktin, void *ctx)
6868 unsigned *sizep = ctx;
6871 * Winadj responses should always be failures. However, at least
6872 * one server ("boks_sshd") is known to return SUCCESS for channel
6873 * requests it's never heard of, such as "winadj@putty". Raised
6874 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6875 * life, we don't worry about what kind of response we got.
6878 c->v.v2.remlocwin += *sizep;
6881 * winadj messages are only sent when the window is fully open, so
6882 * if we get an ack of one, we know any pending unthrottle is
6885 if (c->v.v2.throttle_state == UNTHROTTLING)
6886 c->v.v2.throttle_state = UNTHROTTLED;
6889 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6891 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6892 struct outstanding_channel_request *ocr;
6895 ocr = c->v.v2.chanreq_head;
6897 ssh2_msg_unexpected(ssh, pktin);
6900 ocr->handler(c, pktin, ocr->ctx);
6901 c->v.v2.chanreq_head = ocr->next;
6904 * We may now initiate channel-closing procedures, if that
6905 * CHANNEL_REQUEST was the last thing outstanding before we send
6908 ssh2_channel_check_close(c);
6911 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6913 struct ssh_channel *c;
6914 c = ssh2_channel_msg(ssh, pktin);
6917 if (!(c->closes & CLOSES_SENT_EOF)) {
6918 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6919 ssh2_try_send_and_unthrottle(ssh, c);
6923 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6927 struct ssh_channel *c;
6928 c = ssh2_channel_msg(ssh, pktin);
6931 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6932 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6933 return; /* extended but not stderr */
6934 ssh_pkt_getstring(pktin, &data, &length);
6937 c->v.v2.locwindow -= length;
6938 c->v.v2.remlocwin -= length;
6940 case CHAN_MAINSESSION:
6942 from_backend(ssh->frontend, pktin->type ==
6943 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6947 bufsize = x11_send(c->u.x11.xconn, data, length);
6950 bufsize = pfd_send(c->u.pfd.pf, data, length);
6953 while (length > 0) {
6954 if (c->u.a.lensofar < 4) {
6955 unsigned int l = min(4 - c->u.a.lensofar,
6957 memcpy(c->u.a.msglen + c->u.a.lensofar,
6961 c->u.a.lensofar += l;
6963 if (c->u.a.lensofar == 4) {
6965 4 + GET_32BIT(c->u.a.msglen);
6966 c->u.a.message = snewn(c->u.a.totallen,
6968 memcpy(c->u.a.message, c->u.a.msglen, 4);
6970 if (c->u.a.lensofar >= 4 && length > 0) {
6972 min(c->u.a.totallen - c->u.a.lensofar,
6974 memcpy(c->u.a.message + c->u.a.lensofar,
6978 c->u.a.lensofar += l;
6980 if (c->u.a.lensofar == c->u.a.totallen) {
6983 c->u.a.outstanding_requests++;
6984 if (agent_query(c->u.a.message,
6987 ssh_agentf_callback, c))
6988 ssh_agentf_callback(c, reply, replylen);
6989 sfree(c->u.a.message);
6990 c->u.a.message = NULL;
6991 c->u.a.lensofar = 0;
6998 * If it looks like the remote end hit the end of its window,
6999 * and we didn't want it to do that, think about using a
7002 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7003 c->v.v2.locmaxwin < 0x40000000)
7004 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7006 * If we are not buffering too much data,
7007 * enlarge the window again at the remote side.
7008 * If we are buffering too much, we may still
7009 * need to adjust the window if the server's
7012 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7013 c->v.v2.locmaxwin - bufsize : 0);
7015 * If we're either buffering way too much data, or if we're
7016 * buffering anything at all and we're in "simple" mode,
7017 * throttle the whole channel.
7019 if ((bufsize > c->v.v2.locmaxwin ||
7020 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
7021 !c->throttling_conn) {
7022 c->throttling_conn = 1;
7023 ssh_throttle_conn(ssh, +1);
7028 static void ssh_channel_destroy(struct ssh_channel *c)
7033 case CHAN_MAINSESSION:
7034 ssh->mainchan = NULL;
7035 update_specials_menu(ssh->frontend);
7038 if (c->u.x11.xconn != NULL)
7039 x11_close(c->u.x11.xconn);
7040 logevent("Forwarded X11 connection terminated");
7043 sfree(c->u.a.message);
7046 if (c->u.pfd.pf != NULL)
7047 pfd_close(c->u.pfd.pf);
7048 logevent("Forwarded port closed");
7052 del234(ssh->channels, c);
7053 if (ssh->version == 2) {
7054 bufchain_clear(&c->v.v2.outbuffer);
7055 assert(c->v.v2.chanreq_head == NULL);
7060 * See if that was the last channel left open.
7061 * (This is only our termination condition if we're
7062 * not running in -N mode.)
7064 if (ssh->version == 2 &&
7065 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7066 count234(ssh->channels) == 0) {
7068 * We used to send SSH_MSG_DISCONNECT here,
7069 * because I'd believed that _every_ conforming
7070 * SSH-2 connection had to end with a disconnect
7071 * being sent by at least one side; apparently
7072 * I was wrong and it's perfectly OK to
7073 * unceremoniously slam the connection shut
7074 * when you're done, and indeed OpenSSH feels
7075 * this is more polite than sending a
7076 * DISCONNECT. So now we don't.
7078 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7082 static void ssh2_channel_check_close(struct ssh_channel *c)
7085 struct Packet *pktout;
7089 * If we've sent out our own CHANNEL_OPEN but not yet seen
7090 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7091 * it's too early to be sending close messages of any kind.
7096 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7097 c->type == CHAN_ZOMBIE) &&
7098 !c->v.v2.chanreq_head &&
7099 !(c->closes & CLOSES_SENT_CLOSE)) {
7101 * We have both sent and received EOF (or the channel is a
7102 * zombie), and we have no outstanding channel requests, which
7103 * means the channel is in final wind-up. But we haven't sent
7104 * CLOSE, so let's do so now.
7106 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7107 ssh2_pkt_adduint32(pktout, c->remoteid);
7108 ssh2_pkt_send(ssh, pktout);
7109 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7112 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7113 assert(c->v.v2.chanreq_head == NULL);
7115 * We have both sent and received CLOSE, which means we're
7116 * completely done with the channel.
7118 ssh_channel_destroy(c);
7122 static void ssh2_channel_got_eof(struct ssh_channel *c)
7124 if (c->closes & CLOSES_RCVD_EOF)
7125 return; /* already seen EOF */
7126 c->closes |= CLOSES_RCVD_EOF;
7128 if (c->type == CHAN_X11) {
7129 x11_send_eof(c->u.x11.xconn);
7130 } else if (c->type == CHAN_AGENT) {
7131 if (c->u.a.outstanding_requests == 0) {
7132 /* Manufacture an outgoing EOF in response to the incoming one. */
7133 sshfwd_write_eof(c);
7135 } else if (c->type == CHAN_SOCKDATA) {
7136 pfd_send_eof(c->u.pfd.pf);
7137 } else if (c->type == CHAN_MAINSESSION) {
7140 if (!ssh->sent_console_eof &&
7141 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7143 * Either from_backend_eof told us that the front end
7144 * wants us to close the outgoing side of the connection
7145 * as soon as we see EOF from the far end, or else we've
7146 * unilaterally decided to do that because we've allocated
7147 * a remote pty and hence EOF isn't a particularly
7148 * meaningful concept.
7150 sshfwd_write_eof(c);
7152 ssh->sent_console_eof = TRUE;
7155 ssh2_channel_check_close(c);
7158 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7160 struct ssh_channel *c;
7162 c = ssh2_channel_msg(ssh, pktin);
7165 ssh2_channel_got_eof(c);
7168 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7170 struct ssh_channel *c;
7172 c = ssh2_channel_msg(ssh, pktin);
7177 * When we receive CLOSE on a channel, we assume it comes with an
7178 * implied EOF if we haven't seen EOF yet.
7180 ssh2_channel_got_eof(c);
7183 * And we also send an outgoing EOF, if we haven't already, on the
7184 * assumption that CLOSE is a pretty forceful announcement that
7185 * the remote side is doing away with the entire channel. (If it
7186 * had wanted to send us EOF and continue receiving data from us,
7187 * it would have just sent CHANNEL_EOF.)
7189 if (!(c->closes & CLOSES_SENT_EOF)) {
7191 * Make sure we don't read any more from whatever our local
7192 * data source is for this channel.
7195 case CHAN_MAINSESSION:
7196 ssh->send_ok = 0; /* stop trying to read from stdin */
7199 x11_override_throttle(c->u.x11.xconn, 1);
7202 pfd_override_throttle(c->u.pfd.pf, 1);
7207 * Abandon any buffered data we still wanted to send to this
7208 * channel. Receiving a CHANNEL_CLOSE is an indication that
7209 * the server really wants to get on and _destroy_ this
7210 * channel, and it isn't going to send us any further
7211 * WINDOW_ADJUSTs to permit us to send pending stuff.
7213 bufchain_clear(&c->v.v2.outbuffer);
7216 * Send outgoing EOF.
7218 sshfwd_write_eof(c);
7222 * Now process the actual close.
7224 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7225 c->closes |= CLOSES_RCVD_CLOSE;
7226 ssh2_channel_check_close(c);
7230 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7232 struct ssh_channel *c;
7234 c = ssh2_channel_msg(ssh, pktin);
7237 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7238 c->remoteid = ssh_pkt_getuint32(pktin);
7239 c->halfopen = FALSE;
7240 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7241 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7243 if (c->type == CHAN_SOCKDATA_DORMANT) {
7244 c->type = CHAN_SOCKDATA;
7246 pfd_confirm(c->u.pfd.pf);
7247 } else if (c->type == CHAN_ZOMBIE) {
7249 * This case can occur if a local socket error occurred
7250 * between us sending out CHANNEL_OPEN and receiving
7251 * OPEN_CONFIRMATION. In this case, all we can do is
7252 * immediately initiate close proceedings now that we know the
7253 * server's id to put in the close message.
7255 ssh2_channel_check_close(c);
7258 * We never expect to receive OPEN_CONFIRMATION for any
7259 * *other* channel type (since only local-to-remote port
7260 * forwardings cause us to send CHANNEL_OPEN after the main
7261 * channel is live - all other auxiliary channel types are
7262 * initiated from the server end). It's safe to enforce this
7263 * by assertion rather than by ssh_disconnect, because the
7264 * real point is that we never constructed a half-open channel
7265 * structure in the first place with any type other than the
7268 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7272 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7275 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7277 static const char *const reasons[] = {
7278 "<unknown reason code>",
7279 "Administratively prohibited",
7281 "Unknown channel type",
7282 "Resource shortage",
7284 unsigned reason_code;
7285 char *reason_string;
7287 struct ssh_channel *c;
7289 c = ssh2_channel_msg(ssh, pktin);
7292 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7294 if (c->type == CHAN_SOCKDATA_DORMANT) {
7295 reason_code = ssh_pkt_getuint32(pktin);
7296 if (reason_code >= lenof(reasons))
7297 reason_code = 0; /* ensure reasons[reason_code] in range */
7298 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7299 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7300 reasons[reason_code], reason_length, reason_string);
7302 pfd_close(c->u.pfd.pf);
7303 } else if (c->type == CHAN_ZOMBIE) {
7305 * This case can occur if a local socket error occurred
7306 * between us sending out CHANNEL_OPEN and receiving
7307 * OPEN_FAILURE. In this case, we need do nothing except allow
7308 * the code below to throw the half-open channel away.
7312 * We never expect to receive OPEN_FAILURE for any *other*
7313 * channel type (since only local-to-remote port forwardings
7314 * cause us to send CHANNEL_OPEN after the main channel is
7315 * live - all other auxiliary channel types are initiated from
7316 * the server end). It's safe to enforce this by assertion
7317 * rather than by ssh_disconnect, because the real point is
7318 * that we never constructed a half-open channel structure in
7319 * the first place with any type other than the above.
7321 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7324 del234(ssh->channels, c);
7328 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7331 int typelen, want_reply;
7332 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7333 struct ssh_channel *c;
7334 struct Packet *pktout;
7336 c = ssh2_channel_msg(ssh, pktin);
7339 ssh_pkt_getstring(pktin, &type, &typelen);
7340 want_reply = ssh2_pkt_getbool(pktin);
7343 * Having got the channel number, we now look at
7344 * the request type string to see if it's something
7347 if (c == ssh->mainchan) {
7349 * We recognise "exit-status" and "exit-signal" on
7350 * the primary channel.
7352 if (typelen == 11 &&
7353 !memcmp(type, "exit-status", 11)) {
7355 ssh->exitcode = ssh_pkt_getuint32(pktin);
7356 logeventf(ssh, "Server sent command exit status %d",
7358 reply = SSH2_MSG_CHANNEL_SUCCESS;
7360 } else if (typelen == 11 &&
7361 !memcmp(type, "exit-signal", 11)) {
7363 int is_plausible = TRUE, is_int = FALSE;
7364 char *fmt_sig = "", *fmt_msg = "";
7366 int msglen = 0, core = FALSE;
7367 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7368 * provide an `int' for the signal, despite its
7369 * having been a `string' in the drafts of RFC 4254 since at
7370 * least 2001. (Fixed in session.c 1.147.) Try to
7371 * infer which we can safely parse it as. */
7373 unsigned char *p = pktin->body +
7375 long len = pktin->length - pktin->savedpos;
7376 unsigned long num = GET_32BIT(p); /* what is it? */
7377 /* If it's 0, it hardly matters; assume string */
7381 int maybe_int = FALSE, maybe_str = FALSE;
7382 #define CHECK_HYPOTHESIS(offset, result) \
7385 int q = toint(offset); \
7386 if (q >= 0 && q+4 <= len) { \
7387 q = toint(q + 4 + GET_32BIT(p+q)); \
7388 if (q >= 0 && q+4 <= len && \
7389 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7394 CHECK_HYPOTHESIS(4+1, maybe_int);
7395 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7396 #undef CHECK_HYPOTHESIS
7397 if (maybe_int && !maybe_str)
7399 else if (!maybe_int && maybe_str)
7402 /* Crikey. Either or neither. Panic. */
7403 is_plausible = FALSE;
7406 ssh->exitcode = 128; /* means `unknown signal' */
7409 /* Old non-standard OpenSSH. */
7410 int signum = ssh_pkt_getuint32(pktin);
7411 fmt_sig = dupprintf(" %d", signum);
7412 ssh->exitcode = 128 + signum;
7414 /* As per RFC 4254. */
7417 ssh_pkt_getstring(pktin, &sig, &siglen);
7418 /* Signal name isn't supposed to be blank, but
7419 * let's cope gracefully if it is. */
7421 fmt_sig = dupprintf(" \"%.*s\"",
7426 * Really hideous method of translating the
7427 * signal description back into a locally
7428 * meaningful number.
7433 #define TRANSLATE_SIGNAL(s) \
7434 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7435 ssh->exitcode = 128 + SIG ## s
7437 TRANSLATE_SIGNAL(ABRT);
7440 TRANSLATE_SIGNAL(ALRM);
7443 TRANSLATE_SIGNAL(FPE);
7446 TRANSLATE_SIGNAL(HUP);
7449 TRANSLATE_SIGNAL(ILL);
7452 TRANSLATE_SIGNAL(INT);
7455 TRANSLATE_SIGNAL(KILL);
7458 TRANSLATE_SIGNAL(PIPE);
7461 TRANSLATE_SIGNAL(QUIT);
7464 TRANSLATE_SIGNAL(SEGV);
7467 TRANSLATE_SIGNAL(TERM);
7470 TRANSLATE_SIGNAL(USR1);
7473 TRANSLATE_SIGNAL(USR2);
7475 #undef TRANSLATE_SIGNAL
7477 ssh->exitcode = 128;
7479 core = ssh2_pkt_getbool(pktin);
7480 ssh_pkt_getstring(pktin, &msg, &msglen);
7482 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7484 /* ignore lang tag */
7485 } /* else don't attempt to parse */
7486 logeventf(ssh, "Server exited on signal%s%s%s",
7487 fmt_sig, core ? " (core dumped)" : "",
7489 if (*fmt_sig) sfree(fmt_sig);
7490 if (*fmt_msg) sfree(fmt_msg);
7491 reply = SSH2_MSG_CHANNEL_SUCCESS;
7496 * This is a channel request we don't know
7497 * about, so we now either ignore the request
7498 * or respond with CHANNEL_FAILURE, depending
7501 reply = SSH2_MSG_CHANNEL_FAILURE;
7504 pktout = ssh2_pkt_init(reply);
7505 ssh2_pkt_adduint32(pktout, c->remoteid);
7506 ssh2_pkt_send(ssh, pktout);
7510 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7513 int typelen, want_reply;
7514 struct Packet *pktout;
7516 ssh_pkt_getstring(pktin, &type, &typelen);
7517 want_reply = ssh2_pkt_getbool(pktin);
7520 * We currently don't support any global requests
7521 * at all, so we either ignore the request or
7522 * respond with REQUEST_FAILURE, depending on
7526 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7527 ssh2_pkt_send(ssh, pktout);
7531 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7539 struct ssh_channel *c;
7540 unsigned remid, winsize, pktsize;
7541 struct Packet *pktout;
7543 ssh_pkt_getstring(pktin, &type, &typelen);
7544 c = snew(struct ssh_channel);
7547 remid = ssh_pkt_getuint32(pktin);
7548 winsize = ssh_pkt_getuint32(pktin);
7549 pktsize = ssh_pkt_getuint32(pktin);
7551 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7555 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7556 addrstr = snewn(peeraddrlen+1, char);
7557 memcpy(addrstr, peeraddr, peeraddrlen);
7558 addrstr[peeraddrlen] = '\0';
7559 peerport = ssh_pkt_getuint32(pktin);
7561 logeventf(ssh, "Received X11 connect request from %s:%d",
7564 if (!ssh->X11_fwd_enabled)
7565 error = "X11 forwarding is not enabled";
7566 else if ((x11err = x11_init(&c->u.x11.xconn, ssh->x11disp, c,
7567 addrstr, peerport)) != NULL) {
7568 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7570 error = "Unable to open an X11 connection";
7572 logevent("Opening X11 forward connection succeeded");
7577 } else if (typelen == 15 &&
7578 !memcmp(type, "forwarded-tcpip", 15)) {
7579 struct ssh_rportfwd pf, *realpf;
7582 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
7583 pf.shost = dupprintf("%.*s", shostlen, shost);
7584 pf.sport = ssh_pkt_getuint32(pktin);
7585 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7586 peerport = ssh_pkt_getuint32(pktin);
7587 realpf = find234(ssh->rportfwds, &pf, NULL);
7588 logeventf(ssh, "Received remote port %s:%d open request "
7589 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
7592 if (realpf == NULL) {
7593 error = "Remote port is not recognised";
7595 char *err = pfd_connect(&c->u.pfd.pf,
7599 realpf->pfrec->addressfamily);
7600 logeventf(ssh, "Attempting to forward remote port to "
7601 "%s:%d", realpf->dhost, realpf->dport);
7603 logeventf(ssh, "Port open failed: %s", err);
7605 error = "Port open failed";
7607 logevent("Forwarded port opened successfully");
7608 c->type = CHAN_SOCKDATA;
7611 } else if (typelen == 22 &&
7612 !memcmp(type, "auth-agent@openssh.com", 22)) {
7613 if (!ssh->agentfwd_enabled)
7614 error = "Agent forwarding is not enabled";
7616 c->type = CHAN_AGENT; /* identify channel type */
7617 c->u.a.lensofar = 0;
7618 c->u.a.message = NULL;
7619 c->u.a.outstanding_requests = 0;
7622 error = "Unsupported channel type requested";
7625 c->remoteid = remid;
7626 c->halfopen = FALSE;
7628 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7629 ssh2_pkt_adduint32(pktout, c->remoteid);
7630 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7631 ssh2_pkt_addstring(pktout, error);
7632 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7633 ssh2_pkt_send(ssh, pktout);
7634 logeventf(ssh, "Rejected channel open: %s", error);
7637 ssh2_channel_init(c);
7638 c->v.v2.remwindow = winsize;
7639 c->v.v2.remmaxpkt = pktsize;
7640 add234(ssh->channels, c);
7641 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7642 ssh2_pkt_adduint32(pktout, c->remoteid);
7643 ssh2_pkt_adduint32(pktout, c->localid);
7644 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7645 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7646 ssh2_pkt_send(ssh, pktout);
7651 * Buffer banner messages for later display at some convenient point,
7652 * if we're going to display them.
7654 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7656 /* Arbitrary limit to prevent unbounded inflation of buffer */
7657 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7658 bufchain_size(&ssh->banner) <= 131072) {
7659 char *banner = NULL;
7661 ssh_pkt_getstring(pktin, &banner, &size);
7663 bufchain_add(&ssh->banner, banner, size);
7667 /* Helper function to deal with sending tty modes for "pty-req" */
7668 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7670 struct Packet *pktout = (struct Packet *)data;
7672 unsigned int arg = 0;
7673 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7674 if (i == lenof(ssh_ttymodes)) return;
7675 switch (ssh_ttymodes[i].type) {
7677 arg = ssh_tty_parse_specchar(val);
7680 arg = ssh_tty_parse_boolean(val);
7683 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7684 ssh2_pkt_adduint32(pktout, arg);
7687 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7690 struct ssh2_setup_x11_state {
7694 struct Packet *pktout;
7695 crStateP(ssh2_setup_x11_state, ctx);
7699 logevent("Requesting X11 forwarding");
7700 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7702 ssh2_pkt_addbool(pktout, 0); /* many connections */
7703 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7704 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7705 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7706 ssh2_pkt_send(ssh, pktout);
7708 /* Wait to be called back with either a response packet, or NULL
7709 * meaning clean up and free our data */
7713 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7714 logevent("X11 forwarding enabled");
7715 ssh->X11_fwd_enabled = TRUE;
7717 logevent("X11 forwarding refused");
7723 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7726 struct ssh2_setup_agent_state {
7730 struct Packet *pktout;
7731 crStateP(ssh2_setup_agent_state, ctx);
7735 logevent("Requesting OpenSSH-style agent forwarding");
7736 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7737 ssh2_setup_agent, s);
7738 ssh2_pkt_send(ssh, pktout);
7740 /* Wait to be called back with either a response packet, or NULL
7741 * meaning clean up and free our data */
7745 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7746 logevent("Agent forwarding enabled");
7747 ssh->agentfwd_enabled = TRUE;
7749 logevent("Agent forwarding refused");
7755 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7758 struct ssh2_setup_pty_state {
7762 struct Packet *pktout;
7763 crStateP(ssh2_setup_pty_state, ctx);
7767 /* Unpick the terminal-speed string. */
7768 /* XXX perhaps we should allow no speeds to be sent. */
7769 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7770 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7771 /* Build the pty request. */
7772 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7774 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7775 ssh2_pkt_adduint32(pktout, ssh->term_width);
7776 ssh2_pkt_adduint32(pktout, ssh->term_height);
7777 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7778 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7779 ssh2_pkt_addstring_start(pktout);
7780 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7781 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7782 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7783 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7784 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7785 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7786 ssh2_pkt_send(ssh, pktout);
7787 ssh->state = SSH_STATE_INTERMED;
7789 /* Wait to be called back with either a response packet, or NULL
7790 * meaning clean up and free our data */
7794 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7795 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7796 ssh->ospeed, ssh->ispeed);
7797 ssh->got_pty = TRUE;
7799 c_write_str(ssh, "Server refused to allocate pty\r\n");
7800 ssh->editing = ssh->echoing = 1;
7807 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7810 struct ssh2_setup_env_state {
7812 int num_env, env_left, env_ok;
7815 struct Packet *pktout;
7816 crStateP(ssh2_setup_env_state, ctx);
7821 * Send environment variables.
7823 * Simplest thing here is to send all the requests at once, and
7824 * then wait for a whole bunch of successes or failures.
7830 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7832 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7833 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7834 ssh2_pkt_addstring(pktout, key);
7835 ssh2_pkt_addstring(pktout, val);
7836 ssh2_pkt_send(ssh, pktout);
7841 logeventf(ssh, "Sent %d environment variables", s->num_env);
7846 s->env_left = s->num_env;
7848 while (s->env_left > 0) {
7849 /* Wait to be called back with either a response packet,
7850 * or NULL meaning clean up and free our data */
7852 if (!pktin) goto out;
7853 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7858 if (s->env_ok == s->num_env) {
7859 logevent("All environment variables successfully set");
7860 } else if (s->env_ok == 0) {
7861 logevent("All environment variables refused");
7862 c_write_str(ssh, "Server refused to set environment variables\r\n");
7864 logeventf(ssh, "%d environment variables refused",
7865 s->num_env - s->env_ok);
7866 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7874 * Handle the SSH-2 userauth and connection layers.
7876 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7878 do_ssh2_authconn(ssh, NULL, 0, pktin);
7881 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7884 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7887 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7888 struct Packet *pktin)
7890 struct do_ssh2_authconn_state {
7894 AUTH_TYPE_PUBLICKEY,
7895 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7896 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7898 AUTH_TYPE_GSSAPI, /* always QUIET */
7899 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7900 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7902 int done_service_req;
7903 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7904 int tried_pubkey_config, done_agent;
7909 int kbd_inter_refused;
7910 int we_are_in, userauth_success;
7911 prompts_t *cur_prompt;
7916 void *publickey_blob;
7917 int publickey_bloblen;
7918 int publickey_encrypted;
7919 char *publickey_algorithm;
7920 char *publickey_comment;
7921 unsigned char agent_request[5], *agent_response, *agentp;
7922 int agent_responselen;
7923 unsigned char *pkblob_in_agent;
7925 char *pkblob, *alg, *commentp;
7926 int pklen, alglen, commentlen;
7927 int siglen, retlen, len;
7928 char *q, *agentreq, *ret;
7930 struct Packet *pktout;
7933 struct ssh_gss_library *gsslib;
7934 Ssh_gss_ctx gss_ctx;
7935 Ssh_gss_buf gss_buf;
7936 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7937 Ssh_gss_name gss_srv_name;
7938 Ssh_gss_stat gss_stat;
7941 crState(do_ssh2_authconn_state);
7945 /* Register as a handler for all the messages this coroutine handles. */
7946 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7947 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7948 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7949 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7950 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7951 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7952 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7953 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7954 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7955 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7956 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7957 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7958 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7959 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7960 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7961 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7962 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7963 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7964 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7965 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7967 s->done_service_req = FALSE;
7968 s->we_are_in = s->userauth_success = FALSE;
7970 s->tried_gssapi = FALSE;
7973 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7975 * Request userauth protocol, and await a response to it.
7977 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7978 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7979 ssh2_pkt_send(ssh, s->pktout);
7980 crWaitUntilV(pktin);
7981 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7982 s->done_service_req = TRUE;
7984 if (!s->done_service_req) {
7986 * Request connection protocol directly, without authentication.
7988 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7989 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7990 ssh2_pkt_send(ssh, s->pktout);
7991 crWaitUntilV(pktin);
7992 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7993 s->we_are_in = TRUE; /* no auth required */
7995 bombout(("Server refused service request"));
8000 /* Arrange to be able to deal with any BANNERs that come in.
8001 * (We do this now as packets may come in during the next bit.) */
8002 bufchain_init(&ssh->banner);
8003 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8004 ssh2_msg_userauth_banner;
8007 * Misc one-time setup for authentication.
8009 s->publickey_blob = NULL;
8010 if (!s->we_are_in) {
8013 * Load the public half of any configured public key file
8016 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8017 if (!filename_is_null(s->keyfile)) {
8019 logeventf(ssh, "Reading private key file \"%.150s\"",
8020 filename_to_str(s->keyfile));
8021 keytype = key_type(s->keyfile);
8022 if (keytype == SSH_KEYTYPE_SSH2) {
8025 ssh2_userkey_loadpub(s->keyfile,
8026 &s->publickey_algorithm,
8027 &s->publickey_bloblen,
8028 &s->publickey_comment, &error);
8029 if (s->publickey_blob) {
8030 s->publickey_encrypted =
8031 ssh2_userkey_encrypted(s->keyfile, NULL);
8034 logeventf(ssh, "Unable to load private key (%s)",
8036 msgbuf = dupprintf("Unable to load private key file "
8037 "\"%.150s\" (%s)\r\n",
8038 filename_to_str(s->keyfile),
8040 c_write_str(ssh, msgbuf);
8045 logeventf(ssh, "Unable to use this key file (%s)",
8046 key_type_to_str(keytype));
8047 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8049 filename_to_str(s->keyfile),
8050 key_type_to_str(keytype));
8051 c_write_str(ssh, msgbuf);
8053 s->publickey_blob = NULL;
8058 * Find out about any keys Pageant has (but if there's a
8059 * public key configured, filter out all others).
8062 s->agent_response = NULL;
8063 s->pkblob_in_agent = NULL;
8064 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8068 logevent("Pageant is running. Requesting keys.");
8070 /* Request the keys held by the agent. */
8071 PUT_32BIT(s->agent_request, 1);
8072 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8073 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8074 ssh_agent_callback, ssh)) {
8078 bombout(("Unexpected data from server while"
8079 " waiting for agent response"));
8082 } while (pktin || inlen > 0);
8083 r = ssh->agent_response;
8084 s->agent_responselen = ssh->agent_response_len;
8086 s->agent_response = (unsigned char *) r;
8087 if (s->agent_response && s->agent_responselen >= 5 &&
8088 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8091 p = s->agent_response + 5;
8092 s->nkeys = toint(GET_32BIT(p));
8095 * Vet the Pageant response to ensure that the key
8096 * count and blob lengths make sense.
8099 logeventf(ssh, "Pageant response contained a negative"
8100 " key count %d", s->nkeys);
8102 goto done_agent_query;
8104 unsigned char *q = p + 4;
8105 int lenleft = s->agent_responselen - 5 - 4;
8107 for (keyi = 0; keyi < s->nkeys; keyi++) {
8108 int bloblen, commentlen;
8110 logeventf(ssh, "Pageant response was truncated");
8112 goto done_agent_query;
8114 bloblen = toint(GET_32BIT(q));
8115 if (bloblen < 0 || bloblen > lenleft) {
8116 logeventf(ssh, "Pageant response was truncated");
8118 goto done_agent_query;
8120 lenleft -= 4 + bloblen;
8122 commentlen = toint(GET_32BIT(q));
8123 if (commentlen < 0 || commentlen > lenleft) {
8124 logeventf(ssh, "Pageant response was truncated");
8126 goto done_agent_query;
8128 lenleft -= 4 + commentlen;
8129 q += 4 + commentlen;
8134 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8135 if (s->publickey_blob) {
8136 /* See if configured key is in agent. */
8137 for (keyi = 0; keyi < s->nkeys; keyi++) {
8138 s->pklen = toint(GET_32BIT(p));
8139 if (s->pklen == s->publickey_bloblen &&
8140 !memcmp(p+4, s->publickey_blob,
8141 s->publickey_bloblen)) {
8142 logeventf(ssh, "Pageant key #%d matches "
8143 "configured key file", keyi);
8145 s->pkblob_in_agent = p;
8149 p += toint(GET_32BIT(p)) + 4; /* comment */
8151 if (!s->pkblob_in_agent) {
8152 logevent("Configured key file not in Pageant");
8157 logevent("Failed to get reply from Pageant");
8165 * We repeat this whole loop, including the username prompt,
8166 * until we manage a successful authentication. If the user
8167 * types the wrong _password_, they can be sent back to the
8168 * beginning to try another username, if this is configured on.
8169 * (If they specify a username in the config, they are never
8170 * asked, even if they do give a wrong password.)
8172 * I think this best serves the needs of
8174 * - the people who have no configuration, no keys, and just
8175 * want to try repeated (username,password) pairs until they
8176 * type both correctly
8178 * - people who have keys and configuration but occasionally
8179 * need to fall back to passwords
8181 * - people with a key held in Pageant, who might not have
8182 * logged in to a particular machine before; so they want to
8183 * type a username, and then _either_ their key will be
8184 * accepted, _or_ they will type a password. If they mistype
8185 * the username they will want to be able to get back and
8188 s->got_username = FALSE;
8189 while (!s->we_are_in) {
8193 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8195 * We got a username last time round this loop, and
8196 * with change_username turned off we don't try to get
8199 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8200 int ret; /* need not be kept over crReturn */
8201 s->cur_prompt = new_prompts(ssh->frontend);
8202 s->cur_prompt->to_server = TRUE;
8203 s->cur_prompt->name = dupstr("SSH login name");
8204 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8205 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8208 crWaitUntilV(!pktin);
8209 ret = get_userpass_input(s->cur_prompt, in, inlen);
8214 * get_userpass_input() failed to get a username.
8217 free_prompts(s->cur_prompt);
8218 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8221 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8222 free_prompts(s->cur_prompt);
8225 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8226 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8227 c_write_str(ssh, stuff);
8231 s->got_username = TRUE;
8234 * Send an authentication request using method "none": (a)
8235 * just in case it succeeds, and (b) so that we know what
8236 * authentication methods we can usefully try next.
8238 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8240 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8241 ssh2_pkt_addstring(s->pktout, ssh->username);
8242 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8243 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8244 ssh2_pkt_send(ssh, s->pktout);
8245 s->type = AUTH_TYPE_NONE;
8247 s->we_are_in = FALSE;
8249 s->tried_pubkey_config = FALSE;
8250 s->kbd_inter_refused = FALSE;
8252 /* Reset agent request state. */
8253 s->done_agent = FALSE;
8254 if (s->agent_response) {
8255 if (s->pkblob_in_agent) {
8256 s->agentp = s->pkblob_in_agent;
8258 s->agentp = s->agent_response + 5 + 4;
8264 char *methods = NULL;
8268 * Wait for the result of the last authentication request.
8271 crWaitUntilV(pktin);
8273 * Now is a convenient point to spew any banner material
8274 * that we've accumulated. (This should ensure that when
8275 * we exit the auth loop, we haven't any left to deal
8279 int size = bufchain_size(&ssh->banner);
8281 * Don't show the banner if we're operating in
8282 * non-verbose non-interactive mode. (It's probably
8283 * a script, which means nobody will read the
8284 * banner _anyway_, and moreover the printing of
8285 * the banner will screw up processing on the
8286 * output of (say) plink.)
8288 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8289 char *banner = snewn(size, char);
8290 bufchain_fetch(&ssh->banner, banner, size);
8291 c_write_untrusted(ssh, banner, size);
8294 bufchain_clear(&ssh->banner);
8296 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8297 logevent("Access granted");
8298 s->we_are_in = s->userauth_success = TRUE;
8302 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8303 bombout(("Strange packet received during authentication: "
8304 "type %d", pktin->type));
8311 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8312 * we can look at the string in it and know what we can
8313 * helpfully try next.
8315 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8316 ssh_pkt_getstring(pktin, &methods, &methlen);
8317 if (!ssh2_pkt_getbool(pktin)) {
8319 * We have received an unequivocal Access
8320 * Denied. This can translate to a variety of
8321 * messages, or no message at all.
8323 * For forms of authentication which are attempted
8324 * implicitly, by which I mean without printing
8325 * anything in the window indicating that we're
8326 * trying them, we should never print 'Access
8329 * If we do print a message saying that we're
8330 * attempting some kind of authentication, it's OK
8331 * to print a followup message saying it failed -
8332 * but the message may sometimes be more specific
8333 * than simply 'Access denied'.
8335 * Additionally, if we'd just tried password
8336 * authentication, we should break out of this
8337 * whole loop so as to go back to the username
8338 * prompt (iff we're configured to allow
8339 * username change attempts).
8341 if (s->type == AUTH_TYPE_NONE) {
8343 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8344 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8345 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8346 c_write_str(ssh, "Server refused our key\r\n");
8347 logevent("Server refused our key");
8348 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8349 /* This _shouldn't_ happen except by a
8350 * protocol bug causing client and server to
8351 * disagree on what is a correct signature. */
8352 c_write_str(ssh, "Server refused public-key signature"
8353 " despite accepting key!\r\n");
8354 logevent("Server refused public-key signature"
8355 " despite accepting key!");
8356 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8357 /* quiet, so no c_write */
8358 logevent("Server refused keyboard-interactive authentication");
8359 } else if (s->type==AUTH_TYPE_GSSAPI) {
8360 /* always quiet, so no c_write */
8361 /* also, the code down in the GSSAPI block has
8362 * already logged this in the Event Log */
8363 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8364 logevent("Keyboard-interactive authentication failed");
8365 c_write_str(ssh, "Access denied\r\n");
8367 assert(s->type == AUTH_TYPE_PASSWORD);
8368 logevent("Password authentication failed");
8369 c_write_str(ssh, "Access denied\r\n");
8371 if (conf_get_int(ssh->conf, CONF_change_username)) {
8372 /* XXX perhaps we should allow
8373 * keyboard-interactive to do this too? */
8374 s->we_are_in = FALSE;
8379 c_write_str(ssh, "Further authentication required\r\n");
8380 logevent("Further authentication required");
8384 in_commasep_string("publickey", methods, methlen);
8386 in_commasep_string("password", methods, methlen);
8387 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8388 in_commasep_string("keyboard-interactive", methods, methlen);
8391 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8392 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8393 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8394 ssh->gsslibs->nlibraries > 0;
8398 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8400 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8403 * Attempt public-key authentication using a key from Pageant.
8406 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8408 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8410 /* Unpack key from agent response */
8411 s->pklen = toint(GET_32BIT(s->agentp));
8413 s->pkblob = (char *)s->agentp;
8414 s->agentp += s->pklen;
8415 s->alglen = toint(GET_32BIT(s->pkblob));
8416 s->alg = s->pkblob + 4;
8417 s->commentlen = toint(GET_32BIT(s->agentp));
8419 s->commentp = (char *)s->agentp;
8420 s->agentp += s->commentlen;
8421 /* s->agentp now points at next key, if any */
8423 /* See if server will accept it */
8424 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8425 ssh2_pkt_addstring(s->pktout, ssh->username);
8426 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8427 /* service requested */
8428 ssh2_pkt_addstring(s->pktout, "publickey");
8430 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8431 ssh2_pkt_addstring_start(s->pktout);
8432 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8433 ssh2_pkt_addstring_start(s->pktout);
8434 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8435 ssh2_pkt_send(ssh, s->pktout);
8436 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8438 crWaitUntilV(pktin);
8439 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8441 /* Offer of key refused. */
8448 if (flags & FLAG_VERBOSE) {
8449 c_write_str(ssh, "Authenticating with "
8451 c_write(ssh, s->commentp, s->commentlen);
8452 c_write_str(ssh, "\" from agent\r\n");
8456 * Server is willing to accept the key.
8457 * Construct a SIGN_REQUEST.
8459 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8460 ssh2_pkt_addstring(s->pktout, ssh->username);
8461 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8462 /* service requested */
8463 ssh2_pkt_addstring(s->pktout, "publickey");
8465 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8466 ssh2_pkt_addstring_start(s->pktout);
8467 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8468 ssh2_pkt_addstring_start(s->pktout);
8469 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8471 /* Ask agent for signature. */
8472 s->siglen = s->pktout->length - 5 + 4 +
8473 ssh->v2_session_id_len;
8474 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8476 s->len = 1; /* message type */
8477 s->len += 4 + s->pklen; /* key blob */
8478 s->len += 4 + s->siglen; /* data to sign */
8479 s->len += 4; /* flags */
8480 s->agentreq = snewn(4 + s->len, char);
8481 PUT_32BIT(s->agentreq, s->len);
8482 s->q = s->agentreq + 4;
8483 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8484 PUT_32BIT(s->q, s->pklen);
8486 memcpy(s->q, s->pkblob, s->pklen);
8488 PUT_32BIT(s->q, s->siglen);
8490 /* Now the data to be signed... */
8491 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8492 PUT_32BIT(s->q, ssh->v2_session_id_len);
8495 memcpy(s->q, ssh->v2_session_id,
8496 ssh->v2_session_id_len);
8497 s->q += ssh->v2_session_id_len;
8498 memcpy(s->q, s->pktout->data + 5,
8499 s->pktout->length - 5);
8500 s->q += s->pktout->length - 5;
8501 /* And finally the (zero) flags word. */
8503 if (!agent_query(s->agentreq, s->len + 4,
8505 ssh_agent_callback, ssh)) {
8509 bombout(("Unexpected data from server"
8510 " while waiting for agent"
8514 } while (pktin || inlen > 0);
8515 vret = ssh->agent_response;
8516 s->retlen = ssh->agent_response_len;
8521 if (s->retlen >= 9 &&
8522 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8523 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8524 logevent("Sending Pageant's response");
8525 ssh2_add_sigblob(ssh, s->pktout,
8526 s->pkblob, s->pklen,
8528 GET_32BIT(s->ret + 5));
8529 ssh2_pkt_send(ssh, s->pktout);
8530 s->type = AUTH_TYPE_PUBLICKEY;
8532 /* FIXME: less drastic response */
8533 bombout(("Pageant failed to answer challenge"));
8539 /* Do we have any keys left to try? */
8540 if (s->pkblob_in_agent) {
8541 s->done_agent = TRUE;
8542 s->tried_pubkey_config = TRUE;
8545 if (s->keyi >= s->nkeys)
8546 s->done_agent = TRUE;
8549 } else if (s->can_pubkey && s->publickey_blob &&
8550 !s->tried_pubkey_config) {
8552 struct ssh2_userkey *key; /* not live over crReturn */
8553 char *passphrase; /* not live over crReturn */
8555 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8557 s->tried_pubkey_config = TRUE;
8560 * Try the public key supplied in the configuration.
8562 * First, offer the public blob to see if the server is
8563 * willing to accept it.
8565 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8566 ssh2_pkt_addstring(s->pktout, ssh->username);
8567 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8568 /* service requested */
8569 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8570 ssh2_pkt_addbool(s->pktout, FALSE);
8571 /* no signature included */
8572 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8573 ssh2_pkt_addstring_start(s->pktout);
8574 ssh2_pkt_addstring_data(s->pktout,
8575 (char *)s->publickey_blob,
8576 s->publickey_bloblen);
8577 ssh2_pkt_send(ssh, s->pktout);
8578 logevent("Offered public key");
8580 crWaitUntilV(pktin);
8581 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8582 /* Key refused. Give up. */
8583 s->gotit = TRUE; /* reconsider message next loop */
8584 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8585 continue; /* process this new message */
8587 logevent("Offer of public key accepted");
8590 * Actually attempt a serious authentication using
8593 if (flags & FLAG_VERBOSE) {
8594 c_write_str(ssh, "Authenticating with public key \"");
8595 c_write_str(ssh, s->publickey_comment);
8596 c_write_str(ssh, "\"\r\n");
8600 const char *error; /* not live over crReturn */
8601 if (s->publickey_encrypted) {
8603 * Get a passphrase from the user.
8605 int ret; /* need not be kept over crReturn */
8606 s->cur_prompt = new_prompts(ssh->frontend);
8607 s->cur_prompt->to_server = FALSE;
8608 s->cur_prompt->name = dupstr("SSH key passphrase");
8609 add_prompt(s->cur_prompt,
8610 dupprintf("Passphrase for key \"%.100s\": ",
8611 s->publickey_comment),
8613 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8616 crWaitUntilV(!pktin);
8617 ret = get_userpass_input(s->cur_prompt,
8622 /* Failed to get a passphrase. Terminate. */
8623 free_prompts(s->cur_prompt);
8624 ssh_disconnect(ssh, NULL,
8625 "Unable to authenticate",
8626 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8631 dupstr(s->cur_prompt->prompts[0]->result);
8632 free_prompts(s->cur_prompt);
8634 passphrase = NULL; /* no passphrase needed */
8638 * Try decrypting the key.
8640 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8641 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8643 /* burn the evidence */
8644 smemclr(passphrase, strlen(passphrase));
8647 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8649 (key == SSH2_WRONG_PASSPHRASE)) {
8650 c_write_str(ssh, "Wrong passphrase\r\n");
8652 /* and loop again */
8654 c_write_str(ssh, "Unable to load private key (");
8655 c_write_str(ssh, error);
8656 c_write_str(ssh, ")\r\n");
8658 break; /* try something else */
8664 unsigned char *pkblob, *sigblob, *sigdata;
8665 int pkblob_len, sigblob_len, sigdata_len;
8669 * We have loaded the private key and the server
8670 * has announced that it's willing to accept it.
8671 * Hallelujah. Generate a signature and send it.
8673 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8674 ssh2_pkt_addstring(s->pktout, ssh->username);
8675 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8676 /* service requested */
8677 ssh2_pkt_addstring(s->pktout, "publickey");
8679 ssh2_pkt_addbool(s->pktout, TRUE);
8680 /* signature follows */
8681 ssh2_pkt_addstring(s->pktout, key->alg->name);
8682 pkblob = key->alg->public_blob(key->data,
8684 ssh2_pkt_addstring_start(s->pktout);
8685 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8689 * The data to be signed is:
8693 * followed by everything so far placed in the
8696 sigdata_len = s->pktout->length - 5 + 4 +
8697 ssh->v2_session_id_len;
8698 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8700 sigdata = snewn(sigdata_len, unsigned char);
8702 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8703 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8706 memcpy(sigdata+p, ssh->v2_session_id,
8707 ssh->v2_session_id_len);
8708 p += ssh->v2_session_id_len;
8709 memcpy(sigdata+p, s->pktout->data + 5,
8710 s->pktout->length - 5);
8711 p += s->pktout->length - 5;
8712 assert(p == sigdata_len);
8713 sigblob = key->alg->sign(key->data, (char *)sigdata,
8714 sigdata_len, &sigblob_len);
8715 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8716 sigblob, sigblob_len);
8721 ssh2_pkt_send(ssh, s->pktout);
8722 logevent("Sent public key signature");
8723 s->type = AUTH_TYPE_PUBLICKEY;
8724 key->alg->freekey(key->data);
8728 } else if (s->can_gssapi && !s->tried_gssapi) {
8730 /* GSSAPI Authentication */
8735 s->type = AUTH_TYPE_GSSAPI;
8736 s->tried_gssapi = TRUE;
8738 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8741 * Pick the highest GSS library on the preference
8747 for (i = 0; i < ngsslibs; i++) {
8748 int want_id = conf_get_int_int(ssh->conf,
8749 CONF_ssh_gsslist, i);
8750 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8751 if (ssh->gsslibs->libraries[j].id == want_id) {
8752 s->gsslib = &ssh->gsslibs->libraries[j];
8753 goto got_gsslib; /* double break */
8758 * We always expect to have found something in
8759 * the above loop: we only came here if there
8760 * was at least one viable GSS library, and the
8761 * preference list should always mention
8762 * everything and only change the order.
8767 if (s->gsslib->gsslogmsg)
8768 logevent(s->gsslib->gsslogmsg);
8770 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8771 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8772 ssh2_pkt_addstring(s->pktout, ssh->username);
8773 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8774 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8775 logevent("Attempting GSSAPI authentication");
8777 /* add mechanism info */
8778 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8780 /* number of GSSAPI mechanisms */
8781 ssh2_pkt_adduint32(s->pktout,1);
8783 /* length of OID + 2 */
8784 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8785 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8788 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8790 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8792 ssh2_pkt_send(ssh, s->pktout);
8793 crWaitUntilV(pktin);
8794 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8795 logevent("GSSAPI authentication request refused");
8799 /* check returned packet ... */
8801 ssh_pkt_getstring(pktin, &data, &len);
8802 s->gss_rcvtok.value = data;
8803 s->gss_rcvtok.length = len;
8804 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8805 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8806 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8807 memcmp((char *)s->gss_rcvtok.value + 2,
8808 s->gss_buf.value,s->gss_buf.length) ) {
8809 logevent("GSSAPI authentication - wrong response from server");
8813 /* now start running */
8814 s->gss_stat = s->gsslib->import_name(s->gsslib,
8817 if (s->gss_stat != SSH_GSS_OK) {
8818 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8819 logevent("GSSAPI import name failed - Bad service name");
8821 logevent("GSSAPI import name failed");
8825 /* fetch TGT into GSS engine */
8826 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8828 if (s->gss_stat != SSH_GSS_OK) {
8829 logevent("GSSAPI authentication failed to get credentials");
8830 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8834 /* initial tokens are empty */
8835 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8836 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8838 /* now enter the loop */
8840 s->gss_stat = s->gsslib->init_sec_context
8844 conf_get_int(ssh->conf, CONF_gssapifwd),
8848 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8849 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8850 logevent("GSSAPI authentication initialisation failed");
8852 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8853 &s->gss_buf) == SSH_GSS_OK) {
8854 logevent(s->gss_buf.value);
8855 sfree(s->gss_buf.value);
8860 logevent("GSSAPI authentication initialised");
8862 /* Client and server now exchange tokens until GSSAPI
8863 * no longer says CONTINUE_NEEDED */
8865 if (s->gss_sndtok.length != 0) {
8866 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8867 ssh_pkt_addstring_start(s->pktout);
8868 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8869 ssh2_pkt_send(ssh, s->pktout);
8870 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8873 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8874 crWaitUntilV(pktin);
8875 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8876 logevent("GSSAPI authentication - bad server response");
8877 s->gss_stat = SSH_GSS_FAILURE;
8880 ssh_pkt_getstring(pktin, &data, &len);
8881 s->gss_rcvtok.value = data;
8882 s->gss_rcvtok.length = len;
8884 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8886 if (s->gss_stat != SSH_GSS_OK) {
8887 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8888 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8891 logevent("GSSAPI authentication loop finished OK");
8893 /* Now send the MIC */
8895 s->pktout = ssh2_pkt_init(0);
8896 micoffset = s->pktout->length;
8897 ssh_pkt_addstring_start(s->pktout);
8898 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8899 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8900 ssh_pkt_addstring(s->pktout, ssh->username);
8901 ssh_pkt_addstring(s->pktout, "ssh-connection");
8902 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8904 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8905 s->gss_buf.length = s->pktout->length - micoffset;
8907 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8908 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8909 ssh_pkt_addstring_start(s->pktout);
8910 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8911 ssh2_pkt_send(ssh, s->pktout);
8912 s->gsslib->free_mic(s->gsslib, &mic);
8916 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8917 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8920 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8923 * Keyboard-interactive authentication.
8926 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8928 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8930 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8931 ssh2_pkt_addstring(s->pktout, ssh->username);
8932 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8933 /* service requested */
8934 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8936 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8937 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8938 ssh2_pkt_send(ssh, s->pktout);
8940 logevent("Attempting keyboard-interactive authentication");
8942 crWaitUntilV(pktin);
8943 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8944 /* Server is not willing to do keyboard-interactive
8945 * at all (or, bizarrely but legally, accepts the
8946 * user without actually issuing any prompts).
8947 * Give up on it entirely. */
8949 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8950 s->kbd_inter_refused = TRUE; /* don't try it again */
8955 * Loop while the server continues to send INFO_REQUESTs.
8957 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8959 char *name, *inst, *lang;
8960 int name_len, inst_len, lang_len;
8964 * We've got a fresh USERAUTH_INFO_REQUEST.
8965 * Get the preamble and start building a prompt.
8967 ssh_pkt_getstring(pktin, &name, &name_len);
8968 ssh_pkt_getstring(pktin, &inst, &inst_len);
8969 ssh_pkt_getstring(pktin, &lang, &lang_len);
8970 s->cur_prompt = new_prompts(ssh->frontend);
8971 s->cur_prompt->to_server = TRUE;
8974 * Get any prompt(s) from the packet.
8976 s->num_prompts = ssh_pkt_getuint32(pktin);
8977 for (i = 0; i < s->num_prompts; i++) {
8981 static char noprompt[] =
8982 "<server failed to send prompt>: ";
8984 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8985 echo = ssh2_pkt_getbool(pktin);
8988 prompt_len = lenof(noprompt)-1;
8990 add_prompt(s->cur_prompt,
8991 dupprintf("%.*s", prompt_len, prompt),
8996 /* FIXME: better prefix to distinguish from
8998 s->cur_prompt->name =
8999 dupprintf("SSH server: %.*s", name_len, name);
9000 s->cur_prompt->name_reqd = TRUE;
9002 s->cur_prompt->name =
9003 dupstr("SSH server authentication");
9004 s->cur_prompt->name_reqd = FALSE;
9006 /* We add a prefix to try to make it clear that a prompt
9007 * has come from the server.
9008 * FIXME: ugly to print "Using..." in prompt _every_
9009 * time round. Can this be done more subtly? */
9010 /* Special case: for reasons best known to themselves,
9011 * some servers send k-i requests with no prompts and
9012 * nothing to display. Keep quiet in this case. */
9013 if (s->num_prompts || name_len || inst_len) {
9014 s->cur_prompt->instruction =
9015 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9016 inst_len ? "\n" : "", inst_len, inst);
9017 s->cur_prompt->instr_reqd = TRUE;
9019 s->cur_prompt->instr_reqd = FALSE;
9023 * Display any instructions, and get the user's
9027 int ret; /* not live over crReturn */
9028 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9031 crWaitUntilV(!pktin);
9032 ret = get_userpass_input(s->cur_prompt, in, inlen);
9037 * Failed to get responses. Terminate.
9039 free_prompts(s->cur_prompt);
9040 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9041 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9048 * Send the response(s) to the server.
9050 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9051 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9052 for (i=0; i < s->num_prompts; i++) {
9053 ssh2_pkt_addstring(s->pktout,
9054 s->cur_prompt->prompts[i]->result);
9056 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9059 * Free the prompts structure from this iteration.
9060 * If there's another, a new one will be allocated
9061 * when we return to the top of this while loop.
9063 free_prompts(s->cur_prompt);
9066 * Get the next packet in case it's another
9069 crWaitUntilV(pktin);
9074 * We should have SUCCESS or FAILURE now.
9078 } else if (s->can_passwd) {
9081 * Plain old password authentication.
9083 int ret; /* not live over crReturn */
9084 int changereq_first_time; /* not live over crReturn */
9086 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9088 s->cur_prompt = new_prompts(ssh->frontend);
9089 s->cur_prompt->to_server = TRUE;
9090 s->cur_prompt->name = dupstr("SSH password");
9091 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9096 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9099 crWaitUntilV(!pktin);
9100 ret = get_userpass_input(s->cur_prompt, in, inlen);
9105 * Failed to get responses. Terminate.
9107 free_prompts(s->cur_prompt);
9108 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9109 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9114 * Squirrel away the password. (We may need it later if
9115 * asked to change it.)
9117 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9118 free_prompts(s->cur_prompt);
9121 * Send the password packet.
9123 * We pad out the password packet to 256 bytes to make
9124 * it harder for an attacker to find the length of the
9127 * Anyone using a password longer than 256 bytes
9128 * probably doesn't have much to worry about from
9129 * people who find out how long their password is!
9131 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9132 ssh2_pkt_addstring(s->pktout, ssh->username);
9133 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9134 /* service requested */
9135 ssh2_pkt_addstring(s->pktout, "password");
9136 ssh2_pkt_addbool(s->pktout, FALSE);
9137 ssh2_pkt_addstring(s->pktout, s->password);
9138 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9139 logevent("Sent password");
9140 s->type = AUTH_TYPE_PASSWORD;
9143 * Wait for next packet, in case it's a password change
9146 crWaitUntilV(pktin);
9147 changereq_first_time = TRUE;
9149 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9152 * We're being asked for a new password
9153 * (perhaps not for the first time).
9154 * Loop until the server accepts it.
9157 int got_new = FALSE; /* not live over crReturn */
9158 char *prompt; /* not live over crReturn */
9159 int prompt_len; /* not live over crReturn */
9163 if (changereq_first_time)
9164 msg = "Server requested password change";
9166 msg = "Server rejected new password";
9168 c_write_str(ssh, msg);
9169 c_write_str(ssh, "\r\n");
9172 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9174 s->cur_prompt = new_prompts(ssh->frontend);
9175 s->cur_prompt->to_server = TRUE;
9176 s->cur_prompt->name = dupstr("New SSH password");
9177 s->cur_prompt->instruction =
9178 dupprintf("%.*s", prompt_len, prompt);
9179 s->cur_prompt->instr_reqd = TRUE;
9181 * There's no explicit requirement in the protocol
9182 * for the "old" passwords in the original and
9183 * password-change messages to be the same, and
9184 * apparently some Cisco kit supports password change
9185 * by the user entering a blank password originally
9186 * and the real password subsequently, so,
9187 * reluctantly, we prompt for the old password again.
9189 * (On the other hand, some servers don't even bother
9190 * to check this field.)
9192 add_prompt(s->cur_prompt,
9193 dupstr("Current password (blank for previously entered password): "),
9195 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9197 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9201 * Loop until the user manages to enter the same
9206 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9209 crWaitUntilV(!pktin);
9210 ret = get_userpass_input(s->cur_prompt, in, inlen);
9215 * Failed to get responses. Terminate.
9217 /* burn the evidence */
9218 free_prompts(s->cur_prompt);
9219 smemclr(s->password, strlen(s->password));
9221 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9222 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9228 * If the user specified a new original password
9229 * (IYSWIM), overwrite any previously specified
9231 * (A side effect is that the user doesn't have to
9232 * re-enter it if they louse up the new password.)
9234 if (s->cur_prompt->prompts[0]->result[0]) {
9235 smemclr(s->password, strlen(s->password));
9236 /* burn the evidence */
9239 dupstr(s->cur_prompt->prompts[0]->result);
9243 * Check the two new passwords match.
9245 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9246 s->cur_prompt->prompts[2]->result)
9249 /* They don't. Silly user. */
9250 c_write_str(ssh, "Passwords do not match\r\n");
9255 * Send the new password (along with the old one).
9256 * (see above for padding rationale)
9258 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9259 ssh2_pkt_addstring(s->pktout, ssh->username);
9260 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9261 /* service requested */
9262 ssh2_pkt_addstring(s->pktout, "password");
9263 ssh2_pkt_addbool(s->pktout, TRUE);
9264 ssh2_pkt_addstring(s->pktout, s->password);
9265 ssh2_pkt_addstring(s->pktout,
9266 s->cur_prompt->prompts[1]->result);
9267 free_prompts(s->cur_prompt);
9268 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9269 logevent("Sent new password");
9272 * Now see what the server has to say about it.
9273 * (If it's CHANGEREQ again, it's not happy with the
9276 crWaitUntilV(pktin);
9277 changereq_first_time = FALSE;
9282 * We need to reexamine the current pktin at the top
9283 * of the loop. Either:
9284 * - we weren't asked to change password at all, in
9285 * which case it's a SUCCESS or FAILURE with the
9287 * - we sent a new password, and the server was
9288 * either OK with it (SUCCESS or FAILURE w/partial
9289 * success) or unhappy with the _old_ password
9290 * (FAILURE w/o partial success)
9291 * In any of these cases, we go back to the top of
9292 * the loop and start again.
9297 * We don't need the old password any more, in any
9298 * case. Burn the evidence.
9300 smemclr(s->password, strlen(s->password));
9304 char *str = dupprintf("No supported authentication methods available"
9305 " (server sent: %.*s)",
9308 ssh_disconnect(ssh, str,
9309 "No supported authentication methods available",
9310 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9320 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9322 /* Clear up various bits and pieces from authentication. */
9323 if (s->publickey_blob) {
9324 sfree(s->publickey_blob);
9325 sfree(s->publickey_comment);
9327 if (s->agent_response)
9328 sfree(s->agent_response);
9330 if (s->userauth_success) {
9332 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9333 * packets since. Signal the transport layer to consider enacting
9334 * delayed compression.
9336 * (Relying on we_are_in is not sufficient, as
9337 * draft-miller-secsh-compression-delayed is quite clear that it
9338 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9339 * become set for other reasons.)
9341 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9345 * Now the connection protocol has started, one way or another.
9348 ssh->channels = newtree234(ssh_channelcmp);
9351 * Set up handlers for some connection protocol messages, so we
9352 * don't have to handle them repeatedly in this coroutine.
9354 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9355 ssh2_msg_channel_window_adjust;
9356 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9357 ssh2_msg_global_request;
9360 * Create the main session channel.
9362 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9363 ssh->mainchan = NULL;
9365 ssh->mainchan = snew(struct ssh_channel);
9366 ssh->mainchan->ssh = ssh;
9367 ssh2_channel_init(ssh->mainchan);
9369 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9371 * Just start a direct-tcpip channel and use it as the main
9374 ssh_send_port_open(ssh->mainchan,
9375 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9376 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9380 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9381 logevent("Opening session as main channel");
9382 ssh2_pkt_send(ssh, s->pktout);
9383 ssh->ncmode = FALSE;
9385 crWaitUntilV(pktin);
9386 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9387 bombout(("Server refused to open channel"));
9389 /* FIXME: error data comes back in FAILURE packet */
9391 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9392 bombout(("Server's channel confirmation cited wrong channel"));
9395 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9396 ssh->mainchan->halfopen = FALSE;
9397 ssh->mainchan->type = CHAN_MAINSESSION;
9398 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9399 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9400 add234(ssh->channels, ssh->mainchan);
9401 update_specials_menu(ssh->frontend);
9402 logevent("Opened main channel");
9406 * Now we have a channel, make dispatch table entries for
9407 * general channel-based messages.
9409 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9410 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9411 ssh2_msg_channel_data;
9412 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9413 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9414 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9415 ssh2_msg_channel_open_confirmation;
9416 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9417 ssh2_msg_channel_open_failure;
9418 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9419 ssh2_msg_channel_request;
9420 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9421 ssh2_msg_channel_open;
9422 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9423 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9426 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9428 * This message indicates to the server that we promise
9429 * not to try to run any other channel in parallel with
9430 * this one, so it's safe for it to advertise a very large
9431 * window and leave the flow control to TCP.
9433 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9434 "simple@putty.projects.tartarus.org",
9436 ssh2_pkt_send(ssh, s->pktout);
9440 * Enable port forwardings.
9442 ssh_setup_portfwd(ssh, ssh->conf);
9444 if (ssh->mainchan && !ssh->ncmode) {
9446 * Send the CHANNEL_REQUESTS for the main session channel.
9447 * Each one is handled by its own little asynchronous
9451 /* Potentially enable X11 forwarding. */
9452 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9454 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9455 conf_get_int(ssh->conf, CONF_x11_auth),
9457 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9459 /* Potentially enable agent forwarding. */
9460 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9461 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9463 /* Now allocate a pty for the session. */
9464 if (!conf_get_int(ssh->conf, CONF_nopty))
9465 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9467 /* Send environment variables. */
9468 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9471 * Start a shell or a remote command. We may have to attempt
9472 * this twice if the config data has provided a second choice
9479 if (ssh->fallback_cmd) {
9480 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9481 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9483 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9484 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9488 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9489 ssh2_response_authconn, NULL);
9490 ssh2_pkt_addstring(s->pktout, cmd);
9492 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9493 ssh2_response_authconn, NULL);
9494 ssh2_pkt_addstring(s->pktout, cmd);
9496 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9497 ssh2_response_authconn, NULL);
9499 ssh2_pkt_send(ssh, s->pktout);
9501 crWaitUntilV(pktin);
9503 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9504 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9505 bombout(("Unexpected response to shell/command request:"
9506 " packet type %d", pktin->type));
9510 * We failed to start the command. If this is the
9511 * fallback command, we really are finished; if it's
9512 * not, and if the fallback command exists, try falling
9513 * back to it before complaining.
9515 if (!ssh->fallback_cmd &&
9516 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9517 logevent("Primary command failed; attempting fallback");
9518 ssh->fallback_cmd = TRUE;
9521 bombout(("Server refused to start a shell/command"));
9524 logevent("Started a shell/command");
9529 ssh->editing = ssh->echoing = TRUE;
9532 ssh->state = SSH_STATE_SESSION;
9533 if (ssh->size_needed)
9534 ssh_size(ssh, ssh->term_width, ssh->term_height);
9535 if (ssh->eof_needed)
9536 ssh_special(ssh, TS_EOF);
9542 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9547 s->try_send = FALSE;
9551 * _All_ the connection-layer packets we expect to
9552 * receive are now handled by the dispatch table.
9553 * Anything that reaches here must be bogus.
9556 bombout(("Strange packet received: type %d", pktin->type));
9558 } else if (ssh->mainchan) {
9560 * We have spare data. Add it to the channel buffer.
9562 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9567 struct ssh_channel *c;
9569 * Try to send data on all channels if we can.
9571 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9572 ssh2_try_send_and_unthrottle(ssh, c);
9580 * Handlers for SSH-2 messages that might arrive at any moment.
9582 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9584 /* log reason code in disconnect message */
9588 reason = ssh_pkt_getuint32(pktin);
9589 ssh_pkt_getstring(pktin, &msg, &msglen);
9591 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9592 buf = dupprintf("Received disconnect message (%s)",
9593 ssh2_disconnect_reasons[reason]);
9595 buf = dupprintf("Received disconnect message (unknown"
9596 " type %d)", reason);
9600 buf = dupprintf("Disconnection message text: %.*s",
9603 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9605 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9606 ssh2_disconnect_reasons[reason] : "unknown",
9611 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9613 /* log the debug message */
9617 /* XXX maybe we should actually take notice of the return value */
9618 ssh2_pkt_getbool(pktin);
9619 ssh_pkt_getstring(pktin, &msg, &msglen);
9621 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9624 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9626 do_ssh2_transport(ssh, NULL, 0, pktin);
9630 * Called if we receive a packet that isn't allowed by the protocol.
9631 * This only applies to packets whose meaning PuTTY understands.
9632 * Entirely unknown packets are handled below.
9634 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9636 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9637 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9639 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9643 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9645 struct Packet *pktout;
9646 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9647 ssh2_pkt_adduint32(pktout, pktin->sequence);
9649 * UNIMPLEMENTED messages MUST appear in the same order as the
9650 * messages they respond to. Hence, never queue them.
9652 ssh2_pkt_send_noqueue(ssh, pktout);
9656 * Handle the top-level SSH-2 protocol.
9658 static void ssh2_protocol_setup(Ssh ssh)
9663 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9665 for (i = 0; i < 256; i++)
9666 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9669 * Initially, we only accept transport messages (and a few generic
9670 * ones). do_ssh2_authconn will add more when it starts.
9671 * Messages that are understood but not currently acceptable go to
9672 * ssh2_msg_unexpected.
9674 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9675 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9676 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9677 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9678 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9679 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9680 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9681 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9682 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9683 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9684 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9685 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9686 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9687 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9688 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9689 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9690 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9691 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9692 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9693 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9694 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9695 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9696 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9697 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9698 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9699 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9700 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9701 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9702 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9703 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9704 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9705 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9706 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9709 * These messages have a special handler from the start.
9711 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9712 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9713 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9716 static void ssh2_timer(void *ctx, unsigned long now)
9720 if (ssh->state == SSH_STATE_CLOSED)
9723 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9724 now == ssh->next_rekey) {
9725 do_ssh2_transport(ssh, "timeout", -1, NULL);
9729 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9730 struct Packet *pktin)
9732 unsigned char *in = (unsigned char *)vin;
9733 if (ssh->state == SSH_STATE_CLOSED)
9737 ssh->incoming_data_size += pktin->encrypted_len;
9738 if (!ssh->kex_in_progress &&
9739 ssh->max_data_size != 0 &&
9740 ssh->incoming_data_size > ssh->max_data_size)
9741 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9745 ssh->packet_dispatch[pktin->type](ssh, pktin);
9746 else if (!ssh->protocol_initial_phase_done)
9747 do_ssh2_transport(ssh, in, inlen, pktin);
9749 do_ssh2_authconn(ssh, in, inlen, pktin);
9752 static void ssh_cache_conf_values(Ssh ssh)
9754 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9758 * Called to set up the connection.
9760 * Returns an error message, or NULL on success.
9762 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9763 Conf *conf, char *host, int port, char **realhost,
9764 int nodelay, int keepalive)
9769 ssh = snew(struct ssh_tag);
9770 ssh->conf = conf_copy(conf);
9771 ssh_cache_conf_values(ssh);
9772 ssh->version = 0; /* when not ready yet */
9775 ssh->v1_cipher_ctx = NULL;
9776 ssh->crcda_ctx = NULL;
9777 ssh->cscipher = NULL;
9778 ssh->cs_cipher_ctx = NULL;
9779 ssh->sccipher = NULL;
9780 ssh->sc_cipher_ctx = NULL;
9782 ssh->cs_mac_ctx = NULL;
9784 ssh->sc_mac_ctx = NULL;
9786 ssh->cs_comp_ctx = NULL;
9788 ssh->sc_comp_ctx = NULL;
9790 ssh->kex_ctx = NULL;
9791 ssh->hostkey = NULL;
9792 ssh->hostkey_str = NULL;
9794 ssh->close_expected = FALSE;
9795 ssh->clean_exit = FALSE;
9796 ssh->state = SSH_STATE_PREPACKET;
9797 ssh->size_needed = FALSE;
9798 ssh->eof_needed = FALSE;
9801 ssh->deferred_send_data = NULL;
9802 ssh->deferred_len = 0;
9803 ssh->deferred_size = 0;
9804 ssh->fallback_cmd = 0;
9805 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9806 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9807 ssh->x11disp = NULL;
9808 ssh->v1_compressing = FALSE;
9809 ssh->v2_outgoing_sequence = 0;
9810 ssh->ssh1_rdpkt_crstate = 0;
9811 ssh->ssh2_rdpkt_crstate = 0;
9812 ssh->ssh_gotdata_crstate = 0;
9813 ssh->do_ssh1_connection_crstate = 0;
9814 ssh->do_ssh_init_state = NULL;
9815 ssh->do_ssh1_login_state = NULL;
9816 ssh->do_ssh2_transport_state = NULL;
9817 ssh->do_ssh2_authconn_state = NULL;
9820 ssh->mainchan = NULL;
9821 ssh->throttled_all = 0;
9822 ssh->v1_stdout_throttling = 0;
9824 ssh->queuelen = ssh->queuesize = 0;
9825 ssh->queueing = FALSE;
9826 ssh->qhead = ssh->qtail = NULL;
9827 ssh->deferred_rekey_reason = NULL;
9828 bufchain_init(&ssh->queued_incoming_data);
9829 ssh->frozen = FALSE;
9830 ssh->username = NULL;
9831 ssh->sent_console_eof = FALSE;
9832 ssh->got_pty = FALSE;
9834 *backend_handle = ssh;
9837 if (crypto_startup() == 0)
9838 return "Microsoft high encryption pack not installed!";
9841 ssh->frontend = frontend_handle;
9842 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9843 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9845 ssh->channels = NULL;
9846 ssh->rportfwds = NULL;
9847 ssh->portfwds = NULL;
9852 ssh->conn_throttle_count = 0;
9853 ssh->overall_bufsize = 0;
9854 ssh->fallback_cmd = 0;
9856 ssh->protocol = NULL;
9858 ssh->protocol_initial_phase_done = FALSE;
9862 ssh->incoming_data_size = ssh->outgoing_data_size =
9863 ssh->deferred_data_size = 0L;
9864 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9865 CONF_ssh_rekey_data));
9866 ssh->kex_in_progress = FALSE;
9869 ssh->gsslibs = NULL;
9872 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9881 static void ssh_free(void *handle)
9883 Ssh ssh = (Ssh) handle;
9884 struct ssh_channel *c;
9885 struct ssh_rportfwd *pf;
9887 if (ssh->v1_cipher_ctx)
9888 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9889 if (ssh->cs_cipher_ctx)
9890 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9891 if (ssh->sc_cipher_ctx)
9892 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9893 if (ssh->cs_mac_ctx)
9894 ssh->csmac->free_context(ssh->cs_mac_ctx);
9895 if (ssh->sc_mac_ctx)
9896 ssh->scmac->free_context(ssh->sc_mac_ctx);
9897 if (ssh->cs_comp_ctx) {
9899 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9901 zlib_compress_cleanup(ssh->cs_comp_ctx);
9903 if (ssh->sc_comp_ctx) {
9905 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9907 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9910 dh_cleanup(ssh->kex_ctx);
9911 sfree(ssh->savedhost);
9913 while (ssh->queuelen-- > 0)
9914 ssh_free_packet(ssh->queue[ssh->queuelen]);
9917 while (ssh->qhead) {
9918 struct queued_handler *qh = ssh->qhead;
9919 ssh->qhead = qh->next;
9922 ssh->qhead = ssh->qtail = NULL;
9924 if (ssh->channels) {
9925 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9928 if (c->u.x11.xconn != NULL)
9929 x11_close(c->u.x11.xconn);
9932 case CHAN_SOCKDATA_DORMANT:
9933 if (c->u.pfd.pf != NULL)
9934 pfd_close(c->u.pfd.pf);
9937 if (ssh->version == 2) {
9938 struct outstanding_channel_request *ocr, *nocr;
9939 ocr = c->v.v2.chanreq_head;
9941 ocr->handler(c, NULL, ocr->ctx);
9946 bufchain_clear(&c->v.v2.outbuffer);
9950 freetree234(ssh->channels);
9951 ssh->channels = NULL;
9954 if (ssh->rportfwds) {
9955 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9957 freetree234(ssh->rportfwds);
9958 ssh->rportfwds = NULL;
9960 sfree(ssh->deferred_send_data);
9962 x11_free_display(ssh->x11disp);
9963 sfree(ssh->do_ssh_init_state);
9964 sfree(ssh->do_ssh1_login_state);
9965 sfree(ssh->do_ssh2_transport_state);
9966 sfree(ssh->do_ssh2_authconn_state);
9969 sfree(ssh->fullhostname);
9970 sfree(ssh->hostkey_str);
9971 if (ssh->crcda_ctx) {
9972 crcda_free_context(ssh->crcda_ctx);
9973 ssh->crcda_ctx = NULL;
9976 ssh_do_close(ssh, TRUE);
9977 expire_timer_context(ssh);
9979 pinger_free(ssh->pinger);
9980 bufchain_clear(&ssh->queued_incoming_data);
9981 sfree(ssh->username);
9982 conf_free(ssh->conf);
9985 ssh_gss_cleanup(ssh->gsslibs);
9993 * Reconfigure the SSH backend.
9995 static void ssh_reconfig(void *handle, Conf *conf)
9997 Ssh ssh = (Ssh) handle;
9998 char *rekeying = NULL, rekey_mandatory = FALSE;
9999 unsigned long old_max_data_size;
10002 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10004 ssh_setup_portfwd(ssh, conf);
10006 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10007 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10009 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10010 unsigned long now = GETTICKCOUNT();
10012 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10013 rekeying = "timeout shortened";
10015 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10019 old_max_data_size = ssh->max_data_size;
10020 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10021 CONF_ssh_rekey_data));
10022 if (old_max_data_size != ssh->max_data_size &&
10023 ssh->max_data_size != 0) {
10024 if (ssh->outgoing_data_size > ssh->max_data_size ||
10025 ssh->incoming_data_size > ssh->max_data_size)
10026 rekeying = "data limit lowered";
10029 if (conf_get_int(ssh->conf, CONF_compression) !=
10030 conf_get_int(conf, CONF_compression)) {
10031 rekeying = "compression setting changed";
10032 rekey_mandatory = TRUE;
10035 for (i = 0; i < CIPHER_MAX; i++)
10036 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10037 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10038 rekeying = "cipher settings changed";
10039 rekey_mandatory = TRUE;
10041 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10042 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10043 rekeying = "cipher settings changed";
10044 rekey_mandatory = TRUE;
10047 conf_free(ssh->conf);
10048 ssh->conf = conf_copy(conf);
10049 ssh_cache_conf_values(ssh);
10052 if (!ssh->kex_in_progress) {
10053 do_ssh2_transport(ssh, rekeying, -1, NULL);
10054 } else if (rekey_mandatory) {
10055 ssh->deferred_rekey_reason = rekeying;
10061 * Called to send data down the SSH connection.
10063 static int ssh_send(void *handle, char *buf, int len)
10065 Ssh ssh = (Ssh) handle;
10067 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10070 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10072 return ssh_sendbuffer(ssh);
10076 * Called to query the current amount of buffered stdin data.
10078 static int ssh_sendbuffer(void *handle)
10080 Ssh ssh = (Ssh) handle;
10081 int override_value;
10083 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10087 * If the SSH socket itself has backed up, add the total backup
10088 * size on that to any individual buffer on the stdin channel.
10090 override_value = 0;
10091 if (ssh->throttled_all)
10092 override_value = ssh->overall_bufsize;
10094 if (ssh->version == 1) {
10095 return override_value;
10096 } else if (ssh->version == 2) {
10097 if (!ssh->mainchan)
10098 return override_value;
10100 return (override_value +
10101 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10108 * Called to set the size of the window from SSH's POV.
10110 static void ssh_size(void *handle, int width, int height)
10112 Ssh ssh = (Ssh) handle;
10113 struct Packet *pktout;
10115 ssh->term_width = width;
10116 ssh->term_height = height;
10118 switch (ssh->state) {
10119 case SSH_STATE_BEFORE_SIZE:
10120 case SSH_STATE_PREPACKET:
10121 case SSH_STATE_CLOSED:
10122 break; /* do nothing */
10123 case SSH_STATE_INTERMED:
10124 ssh->size_needed = TRUE; /* buffer for later */
10126 case SSH_STATE_SESSION:
10127 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10128 if (ssh->version == 1) {
10129 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10130 PKT_INT, ssh->term_height,
10131 PKT_INT, ssh->term_width,
10132 PKT_INT, 0, PKT_INT, 0, PKT_END);
10133 } else if (ssh->mainchan) {
10134 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10136 ssh2_pkt_adduint32(pktout, ssh->term_width);
10137 ssh2_pkt_adduint32(pktout, ssh->term_height);
10138 ssh2_pkt_adduint32(pktout, 0);
10139 ssh2_pkt_adduint32(pktout, 0);
10140 ssh2_pkt_send(ssh, pktout);
10148 * Return a list of the special codes that make sense in this
10151 static const struct telnet_special *ssh_get_specials(void *handle)
10153 static const struct telnet_special ssh1_ignore_special[] = {
10154 {"IGNORE message", TS_NOP}
10156 static const struct telnet_special ssh2_ignore_special[] = {
10157 {"IGNORE message", TS_NOP},
10159 static const struct telnet_special ssh2_rekey_special[] = {
10160 {"Repeat key exchange", TS_REKEY},
10162 static const struct telnet_special ssh2_session_specials[] = {
10165 /* These are the signal names defined by RFC 4254.
10166 * They include all the ISO C signals, but are a subset of the POSIX
10167 * required signals. */
10168 {"SIGINT (Interrupt)", TS_SIGINT},
10169 {"SIGTERM (Terminate)", TS_SIGTERM},
10170 {"SIGKILL (Kill)", TS_SIGKILL},
10171 {"SIGQUIT (Quit)", TS_SIGQUIT},
10172 {"SIGHUP (Hangup)", TS_SIGHUP},
10173 {"More signals", TS_SUBMENU},
10174 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10175 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10176 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10177 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10178 {NULL, TS_EXITMENU}
10180 static const struct telnet_special specials_end[] = {
10181 {NULL, TS_EXITMENU}
10183 /* XXX review this length for any changes: */
10184 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10185 lenof(ssh2_rekey_special) +
10186 lenof(ssh2_session_specials) +
10187 lenof(specials_end)];
10188 Ssh ssh = (Ssh) handle;
10190 #define ADD_SPECIALS(name) \
10192 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10193 memcpy(&ssh_specials[i], name, sizeof name); \
10194 i += lenof(name); \
10197 if (ssh->version == 1) {
10198 /* Don't bother offering IGNORE if we've decided the remote
10199 * won't cope with it, since we wouldn't bother sending it if
10201 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10202 ADD_SPECIALS(ssh1_ignore_special);
10203 } else if (ssh->version == 2) {
10204 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10205 ADD_SPECIALS(ssh2_ignore_special);
10206 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10207 ADD_SPECIALS(ssh2_rekey_special);
10209 ADD_SPECIALS(ssh2_session_specials);
10210 } /* else we're not ready yet */
10213 ADD_SPECIALS(specials_end);
10214 return ssh_specials;
10218 #undef ADD_SPECIALS
10222 * Send special codes. TS_EOF is useful for `plink', so you
10223 * can send an EOF and collect resulting output (e.g. `plink
10226 static void ssh_special(void *handle, Telnet_Special code)
10228 Ssh ssh = (Ssh) handle;
10229 struct Packet *pktout;
10231 if (code == TS_EOF) {
10232 if (ssh->state != SSH_STATE_SESSION) {
10234 * Buffer the EOF in case we are pre-SESSION, so we can
10235 * send it as soon as we reach SESSION.
10237 if (code == TS_EOF)
10238 ssh->eof_needed = TRUE;
10241 if (ssh->version == 1) {
10242 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10243 } else if (ssh->mainchan) {
10244 sshfwd_write_eof(ssh->mainchan);
10245 ssh->send_ok = 0; /* now stop trying to read from stdin */
10247 logevent("Sent EOF message");
10248 } else if (code == TS_PING || code == TS_NOP) {
10249 if (ssh->state == SSH_STATE_CLOSED
10250 || ssh->state == SSH_STATE_PREPACKET) return;
10251 if (ssh->version == 1) {
10252 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10253 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10255 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10256 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10257 ssh2_pkt_addstring_start(pktout);
10258 ssh2_pkt_send_noqueue(ssh, pktout);
10261 } else if (code == TS_REKEY) {
10262 if (!ssh->kex_in_progress && ssh->version == 2) {
10263 do_ssh2_transport(ssh, "at user request", -1, NULL);
10265 } else if (code == TS_BRK) {
10266 if (ssh->state == SSH_STATE_CLOSED
10267 || ssh->state == SSH_STATE_PREPACKET) return;
10268 if (ssh->version == 1) {
10269 logevent("Unable to send BREAK signal in SSH-1");
10270 } else if (ssh->mainchan) {
10271 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10272 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10273 ssh2_pkt_send(ssh, pktout);
10276 /* Is is a POSIX signal? */
10277 char *signame = NULL;
10278 if (code == TS_SIGABRT) signame = "ABRT";
10279 if (code == TS_SIGALRM) signame = "ALRM";
10280 if (code == TS_SIGFPE) signame = "FPE";
10281 if (code == TS_SIGHUP) signame = "HUP";
10282 if (code == TS_SIGILL) signame = "ILL";
10283 if (code == TS_SIGINT) signame = "INT";
10284 if (code == TS_SIGKILL) signame = "KILL";
10285 if (code == TS_SIGPIPE) signame = "PIPE";
10286 if (code == TS_SIGQUIT) signame = "QUIT";
10287 if (code == TS_SIGSEGV) signame = "SEGV";
10288 if (code == TS_SIGTERM) signame = "TERM";
10289 if (code == TS_SIGUSR1) signame = "USR1";
10290 if (code == TS_SIGUSR2) signame = "USR2";
10291 /* The SSH-2 protocol does in principle support arbitrary named
10292 * signals, including signame@domain, but we don't support those. */
10294 /* It's a signal. */
10295 if (ssh->version == 2 && ssh->mainchan) {
10296 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10297 ssh2_pkt_addstring(pktout, signame);
10298 ssh2_pkt_send(ssh, pktout);
10299 logeventf(ssh, "Sent signal SIG%s", signame);
10302 /* Never heard of it. Do nothing */
10307 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10309 Ssh ssh = (Ssh) handle;
10310 struct ssh_channel *c;
10311 c = snew(struct ssh_channel);
10314 ssh2_channel_init(c);
10315 c->halfopen = TRUE;
10316 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10318 add234(ssh->channels, c);
10323 * This is called when stdout/stderr (the entity to which
10324 * from_backend sends data) manages to clear some backlog.
10326 static void ssh_unthrottle(void *handle, int bufsize)
10328 Ssh ssh = (Ssh) handle;
10331 if (ssh->version == 1) {
10332 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10333 ssh->v1_stdout_throttling = 0;
10334 ssh_throttle_conn(ssh, -1);
10337 if (ssh->mainchan) {
10338 ssh2_set_window(ssh->mainchan,
10339 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10340 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10341 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10344 buflimit = ssh->mainchan->v.v2.locmaxwin;
10345 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10346 ssh->mainchan->throttling_conn = 0;
10347 ssh_throttle_conn(ssh, -1);
10353 * Now process any SSH connection data that was stashed in our
10354 * queue while we were frozen.
10356 ssh_process_queued_incoming_data(ssh);
10359 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10361 struct ssh_channel *c = (struct ssh_channel *)channel;
10363 struct Packet *pktout;
10365 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10367 if (ssh->version == 1) {
10368 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10369 PKT_INT, c->localid,
10372 /* PKT_STR, <org:orgport>, */
10375 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10376 ssh2_pkt_addstring(pktout, hostname);
10377 ssh2_pkt_adduint32(pktout, port);
10379 * We make up values for the originator data; partly it's
10380 * too much hassle to keep track, and partly I'm not
10381 * convinced the server should be told details like that
10382 * about my local network configuration.
10383 * The "originator IP address" is syntactically a numeric
10384 * IP address, and some servers (e.g., Tectia) get upset
10385 * if it doesn't match this syntax.
10387 ssh2_pkt_addstring(pktout, "0.0.0.0");
10388 ssh2_pkt_adduint32(pktout, 0);
10389 ssh2_pkt_send(ssh, pktout);
10393 static int ssh_connected(void *handle)
10395 Ssh ssh = (Ssh) handle;
10396 return ssh->s != NULL;
10399 static int ssh_sendok(void *handle)
10401 Ssh ssh = (Ssh) handle;
10402 return ssh->send_ok;
10405 static int ssh_ldisc(void *handle, int option)
10407 Ssh ssh = (Ssh) handle;
10408 if (option == LD_ECHO)
10409 return ssh->echoing;
10410 if (option == LD_EDIT)
10411 return ssh->editing;
10415 static void ssh_provide_ldisc(void *handle, void *ldisc)
10417 Ssh ssh = (Ssh) handle;
10418 ssh->ldisc = ldisc;
10421 static void ssh_provide_logctx(void *handle, void *logctx)
10423 Ssh ssh = (Ssh) handle;
10424 ssh->logctx = logctx;
10427 static int ssh_return_exitcode(void *handle)
10429 Ssh ssh = (Ssh) handle;
10430 if (ssh->s != NULL)
10433 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10437 * cfg_info for SSH is the currently running version of the
10438 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10440 static int ssh_cfg_info(void *handle)
10442 Ssh ssh = (Ssh) handle;
10443 return ssh->version;
10447 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10448 * that fails. This variable is the means by which scp.c can reach
10449 * into the SSH code and find out which one it got.
10451 extern int ssh_fallback_cmd(void *handle)
10453 Ssh ssh = (Ssh) handle;
10454 return ssh->fallback_cmd;
10457 Backend ssh_backend = {
10467 ssh_return_exitcode,
10471 ssh_provide_logctx,