29 * Packet type contexts, so that ssh2_pkt_type can correctly decode
30 * the ambiguous type numbers back into the correct type strings.
41 SSH2_PKTCTX_PUBLICKEY,
47 static const char *const ssh2_disconnect_reasons[] = {
49 "host not allowed to connect",
51 "key exchange failed",
52 "host authentication failed",
55 "service not available",
56 "protocol version not supported",
57 "host key not verifiable",
60 "too many connections",
61 "auth cancelled by user",
62 "no more auth methods available",
67 * Various remote-bug flags.
69 #define BUG_CHOKES_ON_SSH1_IGNORE 1
70 #define BUG_SSH2_HMAC 2
71 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
72 #define BUG_CHOKES_ON_RSA 8
73 #define BUG_SSH2_RSA_PADDING 16
74 #define BUG_SSH2_DERIVEKEY 32
75 #define BUG_SSH2_REKEY 64
76 #define BUG_SSH2_PK_SESSIONID 128
77 #define BUG_SSH2_MAXPKT 256
78 #define BUG_CHOKES_ON_SSH2_IGNORE 512
79 #define BUG_CHOKES_ON_WINADJ 1024
80 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 #define BUG_SSH2_OLDGEX 4096
83 #define DH_MIN_SIZE 1024
84 #define DH_MAX_SIZE 8192
87 * Codes for terminal modes.
88 * Most of these are the same in SSH-1 and SSH-2.
89 * This list is derived from RFC 4254 and
93 const char* const mode;
95 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
97 /* "V" prefix discarded for special characters relative to SSH specs */
98 { "INTR", 1, TTY_OP_CHAR },
99 { "QUIT", 2, TTY_OP_CHAR },
100 { "ERASE", 3, TTY_OP_CHAR },
101 { "KILL", 4, TTY_OP_CHAR },
102 { "EOF", 5, TTY_OP_CHAR },
103 { "EOL", 6, TTY_OP_CHAR },
104 { "EOL2", 7, TTY_OP_CHAR },
105 { "START", 8, TTY_OP_CHAR },
106 { "STOP", 9, TTY_OP_CHAR },
107 { "SUSP", 10, TTY_OP_CHAR },
108 { "DSUSP", 11, TTY_OP_CHAR },
109 { "REPRINT", 12, TTY_OP_CHAR },
110 { "WERASE", 13, TTY_OP_CHAR },
111 { "LNEXT", 14, TTY_OP_CHAR },
112 { "FLUSH", 15, TTY_OP_CHAR },
113 { "SWTCH", 16, TTY_OP_CHAR },
114 { "STATUS", 17, TTY_OP_CHAR },
115 { "DISCARD", 18, TTY_OP_CHAR },
116 { "IGNPAR", 30, TTY_OP_BOOL },
117 { "PARMRK", 31, TTY_OP_BOOL },
118 { "INPCK", 32, TTY_OP_BOOL },
119 { "ISTRIP", 33, TTY_OP_BOOL },
120 { "INLCR", 34, TTY_OP_BOOL },
121 { "IGNCR", 35, TTY_OP_BOOL },
122 { "ICRNL", 36, TTY_OP_BOOL },
123 { "IUCLC", 37, TTY_OP_BOOL },
124 { "IXON", 38, TTY_OP_BOOL },
125 { "IXANY", 39, TTY_OP_BOOL },
126 { "IXOFF", 40, TTY_OP_BOOL },
127 { "IMAXBEL", 41, TTY_OP_BOOL },
128 { "ISIG", 50, TTY_OP_BOOL },
129 { "ICANON", 51, TTY_OP_BOOL },
130 { "XCASE", 52, TTY_OP_BOOL },
131 { "ECHO", 53, TTY_OP_BOOL },
132 { "ECHOE", 54, TTY_OP_BOOL },
133 { "ECHOK", 55, TTY_OP_BOOL },
134 { "ECHONL", 56, TTY_OP_BOOL },
135 { "NOFLSH", 57, TTY_OP_BOOL },
136 { "TOSTOP", 58, TTY_OP_BOOL },
137 { "IEXTEN", 59, TTY_OP_BOOL },
138 { "ECHOCTL", 60, TTY_OP_BOOL },
139 { "ECHOKE", 61, TTY_OP_BOOL },
140 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
141 { "OPOST", 70, TTY_OP_BOOL },
142 { "OLCUC", 71, TTY_OP_BOOL },
143 { "ONLCR", 72, TTY_OP_BOOL },
144 { "OCRNL", 73, TTY_OP_BOOL },
145 { "ONOCR", 74, TTY_OP_BOOL },
146 { "ONLRET", 75, TTY_OP_BOOL },
147 { "CS7", 90, TTY_OP_BOOL },
148 { "CS8", 91, TTY_OP_BOOL },
149 { "PARENB", 92, TTY_OP_BOOL },
150 { "PARODD", 93, TTY_OP_BOOL }
153 /* Miscellaneous other tty-related constants. */
154 #define SSH_TTY_OP_END 0
155 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
156 #define SSH1_TTY_OP_ISPEED 192
157 #define SSH1_TTY_OP_OSPEED 193
158 #define SSH2_TTY_OP_ISPEED 128
159 #define SSH2_TTY_OP_OSPEED 129
161 /* Helper functions for parsing tty-related config. */
162 static unsigned int ssh_tty_parse_specchar(char *s)
167 ret = ctrlparse(s, &next);
168 if (!next) ret = s[0];
170 ret = 255; /* special value meaning "don't set" */
174 static unsigned int ssh_tty_parse_boolean(char *s)
176 if (stricmp(s, "yes") == 0 ||
177 stricmp(s, "on") == 0 ||
178 stricmp(s, "true") == 0 ||
179 stricmp(s, "+") == 0)
181 else if (stricmp(s, "no") == 0 ||
182 stricmp(s, "off") == 0 ||
183 stricmp(s, "false") == 0 ||
184 stricmp(s, "-") == 0)
185 return 0; /* false */
187 return (atoi(s) != 0);
190 #define translate(x) if (type == x) return #x
191 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
192 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
193 static const char *ssh1_pkt_type(int type)
195 translate(SSH1_MSG_DISCONNECT);
196 translate(SSH1_SMSG_PUBLIC_KEY);
197 translate(SSH1_CMSG_SESSION_KEY);
198 translate(SSH1_CMSG_USER);
199 translate(SSH1_CMSG_AUTH_RSA);
200 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
201 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
202 translate(SSH1_CMSG_AUTH_PASSWORD);
203 translate(SSH1_CMSG_REQUEST_PTY);
204 translate(SSH1_CMSG_WINDOW_SIZE);
205 translate(SSH1_CMSG_EXEC_SHELL);
206 translate(SSH1_CMSG_EXEC_CMD);
207 translate(SSH1_SMSG_SUCCESS);
208 translate(SSH1_SMSG_FAILURE);
209 translate(SSH1_CMSG_STDIN_DATA);
210 translate(SSH1_SMSG_STDOUT_DATA);
211 translate(SSH1_SMSG_STDERR_DATA);
212 translate(SSH1_CMSG_EOF);
213 translate(SSH1_SMSG_EXIT_STATUS);
214 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
215 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
216 translate(SSH1_MSG_CHANNEL_DATA);
217 translate(SSH1_MSG_CHANNEL_CLOSE);
218 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
219 translate(SSH1_SMSG_X11_OPEN);
220 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
221 translate(SSH1_MSG_PORT_OPEN);
222 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
223 translate(SSH1_SMSG_AGENT_OPEN);
224 translate(SSH1_MSG_IGNORE);
225 translate(SSH1_CMSG_EXIT_CONFIRMATION);
226 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
227 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
228 translate(SSH1_MSG_DEBUG);
229 translate(SSH1_CMSG_REQUEST_COMPRESSION);
230 translate(SSH1_CMSG_AUTH_TIS);
231 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
233 translate(SSH1_CMSG_AUTH_CCARD);
234 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
235 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
238 static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx,
241 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
242 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
243 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
244 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
245 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
246 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
247 translate(SSH2_MSG_DISCONNECT);
248 translate(SSH2_MSG_IGNORE);
249 translate(SSH2_MSG_UNIMPLEMENTED);
250 translate(SSH2_MSG_DEBUG);
251 translate(SSH2_MSG_SERVICE_REQUEST);
252 translate(SSH2_MSG_SERVICE_ACCEPT);
253 translate(SSH2_MSG_KEXINIT);
254 translate(SSH2_MSG_NEWKEYS);
255 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
256 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
257 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX);
258 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
259 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
260 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
261 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
262 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
263 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
264 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
265 translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
266 translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
267 translate(SSH2_MSG_USERAUTH_REQUEST);
268 translate(SSH2_MSG_USERAUTH_FAILURE);
269 translate(SSH2_MSG_USERAUTH_SUCCESS);
270 translate(SSH2_MSG_USERAUTH_BANNER);
271 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
272 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
273 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
274 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
275 translate(SSH2_MSG_GLOBAL_REQUEST);
276 translate(SSH2_MSG_REQUEST_SUCCESS);
277 translate(SSH2_MSG_REQUEST_FAILURE);
278 translate(SSH2_MSG_CHANNEL_OPEN);
279 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
280 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
281 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
282 translate(SSH2_MSG_CHANNEL_DATA);
283 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
284 translate(SSH2_MSG_CHANNEL_EOF);
285 translate(SSH2_MSG_CHANNEL_CLOSE);
286 translate(SSH2_MSG_CHANNEL_REQUEST);
287 translate(SSH2_MSG_CHANNEL_SUCCESS);
288 translate(SSH2_MSG_CHANNEL_FAILURE);
294 /* Enumeration values for fields in SSH-1 packets */
296 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
300 * Coroutine mechanics for the sillier bits of the code. If these
301 * macros look impenetrable to you, you might find it helpful to
304 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
306 * which explains the theory behind these macros.
308 * In particular, if you are getting `case expression not constant'
309 * errors when building with MS Visual Studio, this is because MS's
310 * Edit and Continue debugging feature causes their compiler to
311 * violate ANSI C. To disable Edit and Continue debugging:
313 * - right-click ssh.c in the FileView
315 * - select the C/C++ tab and the General category
316 * - under `Debug info:', select anything _other_ than `Program
317 * Database for Edit and Continue'.
319 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
320 #define crBeginState crBegin(s->crLine)
321 #define crStateP(t, v) \
323 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
325 #define crState(t) crStateP(t, ssh->t)
326 #define crFinish(z) } *crLine = 0; return (z); }
327 #define crFinishV } *crLine = 0; return; }
328 #define crFinishFree(z) } sfree(s); return (z); }
329 #define crFinishFreeV } sfree(s); return; }
330 #define crReturn(z) \
332 *crLine =__LINE__; return (z); case __LINE__:;\
336 *crLine=__LINE__; return; case __LINE__:;\
338 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
339 #define crStopV do{ *crLine = 0; return; }while(0)
340 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
341 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
345 static struct Packet *ssh1_pkt_init(int pkt_type);
346 static struct Packet *ssh2_pkt_init(int pkt_type);
347 static void ssh_pkt_ensure(struct Packet *, int length);
348 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
349 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
350 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
351 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
352 static void ssh_pkt_addstring_start(struct Packet *);
353 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
354 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
355 static void ssh_pkt_addstring(struct Packet *, const char *data);
356 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
357 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
358 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
359 static int ssh2_pkt_construct(Ssh, struct Packet *);
360 static void ssh2_pkt_send(Ssh, struct Packet *);
361 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
362 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
363 struct Packet *pktin);
364 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
365 struct Packet *pktin);
366 static void ssh2_channel_check_close(struct ssh_channel *c);
367 static void ssh_channel_destroy(struct ssh_channel *c);
368 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin);
371 * Buffer management constants. There are several of these for
372 * various different purposes:
374 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
375 * on a local data stream before we throttle the whole SSH
376 * connection (in SSH-1 only). Throttling the whole connection is
377 * pretty drastic so we set this high in the hope it won't
380 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
381 * on the SSH connection itself before we defensively throttle
382 * _all_ local data streams. This is pretty drastic too (though
383 * thankfully unlikely in SSH-2 since the window mechanism should
384 * ensure that the server never has any need to throttle its end
385 * of the connection), so we set this high as well.
387 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
390 * - OUR_V2_BIGWIN is the window size we advertise for the only
391 * channel in a simple connection. It must be <= INT_MAX.
393 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
394 * to the remote side. This actually has nothing to do with the
395 * size of the _packet_, but is instead a limit on the amount
396 * of data we're willing to receive in a single SSH2 channel
399 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
400 * _packet_ we're prepared to cope with. It must be a multiple
401 * of the cipher block size, and must be at least 35000.
404 #define SSH1_BUFFER_LIMIT 32768
405 #define SSH_MAX_BACKLOG 32768
406 #define OUR_V2_WINSIZE 16384
407 #define OUR_V2_BIGWIN 0x7fffffff
408 #define OUR_V2_MAXPKT 0x4000UL
409 #define OUR_V2_PACKETLIMIT 0x9000UL
411 const static struct ssh_signkey *hostkey_algs[] = {
413 &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
417 const static struct ssh_mac *macs[] = {
418 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
420 const static struct ssh_mac *buggymacs[] = {
421 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
424 static void *ssh_comp_none_init(void)
428 static void ssh_comp_none_cleanup(void *handle)
431 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
432 unsigned char **outblock, int *outlen)
436 static int ssh_comp_none_disable(void *handle)
440 const static struct ssh_compress ssh_comp_none = {
442 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
443 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
444 ssh_comp_none_disable, NULL
446 extern const struct ssh_compress ssh_zlib;
447 const static struct ssh_compress *compressions[] = {
448 &ssh_zlib, &ssh_comp_none
451 enum { /* channel types */
456 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
458 * CHAN_SHARING indicates a channel which is tracked here on
459 * behalf of a connection-sharing downstream. We do almost nothing
460 * with these channels ourselves: all messages relating to them
461 * get thrown straight to sshshare.c and passed on almost
462 * unmodified to downstream.
466 * CHAN_ZOMBIE is used to indicate a channel for which we've
467 * already destroyed the local data source: for instance, if a
468 * forwarded port experiences a socket error on the local side, we
469 * immediately destroy its local socket and turn the SSH channel
475 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
476 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
477 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
480 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
483 struct outstanding_channel_request {
484 cchandler_fn_t handler;
486 struct outstanding_channel_request *next;
490 * 2-3-4 tree storing channels.
493 Ssh ssh; /* pointer back to main context */
494 unsigned remoteid, localid;
496 /* True if we opened this channel but server hasn't confirmed. */
499 * In SSH-1, this value contains four bits:
501 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
502 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
503 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
504 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
506 * A channel is completely finished with when all four bits are set.
508 * In SSH-2, the four bits mean:
510 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
511 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
512 * 4 We have received SSH2_MSG_CHANNEL_EOF.
513 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
515 * A channel is completely finished with when we have both sent
516 * and received CLOSE.
518 * The symbolic constants below use the SSH-2 terminology, which
519 * is a bit confusing in SSH-1, but we have to use _something_.
521 #define CLOSES_SENT_EOF 1
522 #define CLOSES_SENT_CLOSE 2
523 #define CLOSES_RCVD_EOF 4
524 #define CLOSES_RCVD_CLOSE 8
528 * This flag indicates that an EOF is pending on the outgoing side
529 * of the channel: that is, wherever we're getting the data for
530 * this channel has sent us some data followed by EOF. We can't
531 * actually send the EOF until we've finished sending the data, so
532 * we set this flag instead to remind us to do so once our buffer
538 * True if this channel is causing the underlying connection to be
543 struct ssh2_data_channel {
545 unsigned remwindow, remmaxpkt;
546 /* locwindow is signed so we can cope with excess data. */
547 int locwindow, locmaxwin;
549 * remlocwin is the amount of local window that we think
550 * the remote end had available to it after it sent the
551 * last data packet or window adjust ack.
555 * These store the list of channel requests that haven't
558 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
559 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
563 struct ssh_agent_channel {
564 unsigned char *message;
565 unsigned char msglen[4];
566 unsigned lensofar, totallen;
567 int outstanding_requests;
569 struct ssh_x11_channel {
570 struct X11Connection *xconn;
573 struct ssh_pfd_channel {
574 struct PortForwarding *pf;
576 struct ssh_sharing_channel {
583 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
584 * use this structure in different ways, reflecting SSH-2's
585 * altogether saner approach to port forwarding.
587 * In SSH-1, you arrange a remote forwarding by sending the server
588 * the remote port number, and the local destination host:port.
589 * When a connection comes in, the server sends you back that
590 * host:port pair, and you connect to it. This is a ready-made
591 * security hole if you're not on the ball: a malicious server
592 * could send you back _any_ host:port pair, so if you trustingly
593 * connect to the address it gives you then you've just opened the
594 * entire inside of your corporate network just by connecting
595 * through it to a dodgy SSH server. Hence, we must store a list of
596 * host:port pairs we _are_ trying to forward to, and reject a
597 * connection request from the server if it's not in the list.
599 * In SSH-2, each side of the connection minds its own business and
600 * doesn't send unnecessary information to the other. You arrange a
601 * remote forwarding by sending the server just the remote port
602 * number. When a connection comes in, the server tells you which
603 * of its ports was connected to; and _you_ have to remember what
604 * local host:port pair went with that port number.
606 * Hence, in SSH-1 this structure is indexed by destination
607 * host:port pair, whereas in SSH-2 it is indexed by source port.
609 struct ssh_portfwd; /* forward declaration */
611 struct ssh_rportfwd {
612 unsigned sport, dport;
616 struct ssh_portfwd *pfrec;
619 static void free_rportfwd(struct ssh_rportfwd *pf)
622 sfree(pf->sportdesc);
630 * Separately to the rportfwd tree (which is for looking up port
631 * open requests from the server), a tree of _these_ structures is
632 * used to keep track of all the currently open port forwardings,
633 * so that we can reconfigure in mid-session if the user requests
637 enum { DESTROY, KEEP, CREATE } status;
639 unsigned sport, dport;
642 struct ssh_rportfwd *remote;
644 struct PortListener *local;
646 #define free_portfwd(pf) ( \
647 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
648 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
651 long length; /* length of packet: see below */
652 long forcepad; /* SSH-2: force padding to at least this length */
653 int type; /* only used for incoming packets */
654 unsigned long sequence; /* SSH-2 incoming sequence number */
655 unsigned char *data; /* allocated storage */
656 unsigned char *body; /* offset of payload within `data' */
657 long savedpos; /* dual-purpose saved packet position: see below */
658 long maxlen; /* amount of storage allocated for `data' */
659 long encrypted_len; /* for SSH-2 total-size counting */
662 * A note on the 'length' and 'savedpos' fields above.
664 * Incoming packets are set up so that pkt->length is measured
665 * relative to pkt->body, which itself points to a few bytes after
666 * pkt->data (skipping some uninteresting header fields including
667 * the packet type code). The ssh_pkt_get* functions all expect
668 * this setup, and they also use pkt->savedpos to indicate how far
669 * through the packet being decoded they've got - and that, too,
670 * is an offset from pkt->body rather than pkt->data.
672 * During construction of an outgoing packet, however, pkt->length
673 * is measured relative to the base pointer pkt->data, and
674 * pkt->body is not really used for anything until the packet is
675 * ready for sending. In this mode, pkt->savedpos is reused as a
676 * temporary variable by the addstring functions, which write out
677 * a string length field and then keep going back and updating it
678 * as more data is appended to the subsequent string data field;
679 * pkt->savedpos stores the offset (again relative to pkt->data)
680 * of the start of the string data field.
683 /* Extra metadata used in SSH packet logging mode, allowing us to
684 * log in the packet header line that the packet came from a
685 * connection-sharing downstream and what if anything unusual was
686 * done to it. The additional_log_text field is expected to be a
687 * static string - it will not be freed. */
688 unsigned downstream_id;
689 const char *additional_log_text;
692 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
693 struct Packet *pktin);
694 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
695 struct Packet *pktin);
696 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
697 struct Packet *pktin);
698 static void ssh1_protocol_setup(Ssh ssh);
699 static void ssh2_protocol_setup(Ssh ssh);
700 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
701 static void ssh_size(void *handle, int width, int height);
702 static void ssh_special(void *handle, Telnet_Special);
703 static int ssh2_try_send(struct ssh_channel *c);
704 static void ssh2_add_channel_data(struct ssh_channel *c,
705 const char *buf, int len);
706 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
707 static void ssh2_set_window(struct ssh_channel *c, int newwin);
708 static int ssh_sendbuffer(void *handle);
709 static int ssh_do_close(Ssh ssh, int notify_exit);
710 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
711 static int ssh2_pkt_getbool(struct Packet *pkt);
712 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
713 static void ssh2_timer(void *ctx, unsigned long now);
714 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
715 struct Packet *pktin);
716 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
718 struct rdpkt1_state_tag {
719 long len, pad, biglen, to_read;
720 unsigned long realcrc, gotcrc;
724 struct Packet *pktin;
727 struct rdpkt2_state_tag {
728 long len, pad, payload, packetlen, maclen;
731 unsigned long incoming_sequence;
732 struct Packet *pktin;
735 struct rdpkt2_bare_state_tag {
739 unsigned long incoming_sequence;
740 struct Packet *pktin;
743 struct queued_handler;
744 struct queued_handler {
746 chandler_fn_t handler;
748 struct queued_handler *next;
752 const struct plug_function_table *fn;
753 /* the above field _must_ be first in the structure */
763 unsigned char session_key[32];
765 int v1_remote_protoflags;
766 int v1_local_protoflags;
767 int agentfwd_enabled;
770 const struct ssh_cipher *cipher;
773 const struct ssh2_cipher *cscipher, *sccipher;
774 void *cs_cipher_ctx, *sc_cipher_ctx;
775 const struct ssh_mac *csmac, *scmac;
776 int csmac_etm, scmac_etm;
777 void *cs_mac_ctx, *sc_mac_ctx;
778 const struct ssh_compress *cscomp, *sccomp;
779 void *cs_comp_ctx, *sc_comp_ctx;
780 const struct ssh_kex *kex;
781 const struct ssh_signkey *hostkey;
782 char *hostkey_str; /* string representation, for easy checking in rekeys */
783 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
784 int v2_session_id_len;
788 int attempting_connshare;
794 int echoing, editing;
799 int ospeed, ispeed; /* temporaries */
800 int term_width, term_height;
802 tree234 *channels; /* indexed by local id */
803 struct ssh_channel *mainchan; /* primary session channel */
804 int ncmode; /* is primary channel direct-tcpip? */
809 tree234 *rportfwds, *portfwds;
813 SSH_STATE_BEFORE_SIZE,
819 int size_needed, eof_needed;
820 int sent_console_eof;
821 int got_pty; /* affects EOF behaviour on main channel */
823 struct Packet **queue;
824 int queuelen, queuesize;
826 unsigned char *deferred_send_data;
827 int deferred_len, deferred_size;
830 * Gross hack: pscp will try to start SFTP but fall back to
831 * scp1 if that fails. This variable is the means by which
832 * scp.c can reach into the SSH code and find out which one it
837 bufchain banner; /* accumulates banners during do_ssh2_authconn */
842 struct X11Display *x11disp;
843 struct X11FakeAuth *x11auth;
844 tree234 *x11authtree;
847 int conn_throttle_count;
850 int v1_stdout_throttling;
851 unsigned long v2_outgoing_sequence;
853 int ssh1_rdpkt_crstate;
854 int ssh2_rdpkt_crstate;
855 int ssh2_bare_rdpkt_crstate;
856 int ssh_gotdata_crstate;
857 int do_ssh1_connection_crstate;
859 void *do_ssh_init_state;
860 void *do_ssh1_login_state;
861 void *do_ssh2_transport_state;
862 void *do_ssh2_authconn_state;
863 void *do_ssh_connection_init_state;
865 struct rdpkt1_state_tag rdpkt1_state;
866 struct rdpkt2_state_tag rdpkt2_state;
867 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
869 /* SSH-1 and SSH-2 use this for different things, but both use it */
870 int protocol_initial_phase_done;
872 void (*protocol) (Ssh ssh, const void *vin, int inlen,
874 struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data,
876 int (*do_ssh_init)(Ssh ssh, unsigned char c);
879 * We maintain our own copy of a Conf structure here. That way,
880 * when we're passed a new one for reconfiguration, we can check
881 * the differences and potentially reconfigure port forwardings
882 * etc in mid-session.
887 * Values cached out of conf so as to avoid the tree234 lookup
888 * cost every time they're used.
893 * Dynamically allocated username string created during SSH
894 * login. Stored in here rather than in the coroutine state so
895 * that it'll be reliably freed if we shut down the SSH session
896 * at some unexpected moment.
901 * Used to transfer data back from async callbacks.
903 void *agent_response;
904 int agent_response_len;
908 * The SSH connection can be set as `frozen', meaning we are
909 * not currently accepting incoming data from the network. This
910 * is slightly more serious than setting the _socket_ as
911 * frozen, because we may already have had data passed to us
912 * from the network which we need to delay processing until
913 * after the freeze is lifted, so we also need a bufchain to
917 bufchain queued_incoming_data;
920 * Dispatch table for packet types that we may have to deal
923 handler_fn_t packet_dispatch[256];
926 * Queues of one-off handler functions for success/failure
927 * indications from a request.
929 struct queued_handler *qhead, *qtail;
930 handler_fn_t q_saved_handler1, q_saved_handler2;
933 * This module deals with sending keepalives.
938 * Track incoming and outgoing data sizes and time, for
941 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
942 unsigned long max_data_size;
944 unsigned long next_rekey, last_rekey;
945 const char *deferred_rekey_reason;
948 * Fully qualified host name, which we need if doing GSSAPI.
954 * GSSAPI libraries for this session.
956 struct ssh_gss_liblist *gsslibs;
960 * The last list returned from get_specials.
962 struct telnet_special *specials;
965 * List of host key algorithms for which we _don't_ have a stored
966 * host key. These are indices into the main hostkey_algs[] array
968 int uncert_hostkeys[lenof(hostkey_algs)];
969 int n_uncert_hostkeys;
972 * Flag indicating that the current rekey is intended to finish
973 * with a newly cross-certified host key.
975 int cross_certifying;
978 #define logevent(s) logevent(ssh->frontend, s)
980 /* logevent, only printf-formatted. */
981 static void logeventf(Ssh ssh, const char *fmt, ...)
987 buf = dupvprintf(fmt, ap);
993 static void bomb_out(Ssh ssh, char *text)
995 ssh_do_close(ssh, FALSE);
997 connection_fatal(ssh->frontend, "%s", text);
1001 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1003 /* Helper function for common bits of parsing ttymodes. */
1004 static void parse_ttymodes(Ssh ssh,
1005 void (*do_mode)(void *data, char *mode, char *val),
1010 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1012 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1014 * val[0] is either 'V', indicating that an explicit value
1015 * follows it, or 'A' indicating that we should pass the
1016 * value through from the local environment via get_ttymode.
1018 if (val[0] == 'A') {
1019 val = get_ttymode(ssh->frontend, key);
1021 do_mode(data, key, val);
1025 do_mode(data, key, val + 1); /* skip the 'V' */
1029 static int ssh_channelcmp(void *av, void *bv)
1031 struct ssh_channel *a = (struct ssh_channel *) av;
1032 struct ssh_channel *b = (struct ssh_channel *) bv;
1033 if (a->localid < b->localid)
1035 if (a->localid > b->localid)
1039 static int ssh_channelfind(void *av, void *bv)
1041 unsigned *a = (unsigned *) av;
1042 struct ssh_channel *b = (struct ssh_channel *) bv;
1043 if (*a < b->localid)
1045 if (*a > b->localid)
1050 static int ssh_rportcmp_ssh1(void *av, void *bv)
1052 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1053 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1055 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1056 return i < 0 ? -1 : +1;
1057 if (a->dport > b->dport)
1059 if (a->dport < b->dport)
1064 static int ssh_rportcmp_ssh2(void *av, void *bv)
1066 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1067 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1069 if ( (i = strcmp(a->shost, b->shost)) != 0)
1070 return i < 0 ? -1 : +1;
1071 if (a->sport > b->sport)
1073 if (a->sport < b->sport)
1079 * Special form of strcmp which can cope with NULL inputs. NULL is
1080 * defined to sort before even the empty string.
1082 static int nullstrcmp(const char *a, const char *b)
1084 if (a == NULL && b == NULL)
1090 return strcmp(a, b);
1093 static int ssh_portcmp(void *av, void *bv)
1095 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1096 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1098 if (a->type > b->type)
1100 if (a->type < b->type)
1102 if (a->addressfamily > b->addressfamily)
1104 if (a->addressfamily < b->addressfamily)
1106 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1107 return i < 0 ? -1 : +1;
1108 if (a->sport > b->sport)
1110 if (a->sport < b->sport)
1112 if (a->type != 'D') {
1113 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1114 return i < 0 ? -1 : +1;
1115 if (a->dport > b->dport)
1117 if (a->dport < b->dport)
1123 static int alloc_channel_id(Ssh ssh)
1125 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1126 unsigned low, high, mid;
1128 struct ssh_channel *c;
1131 * First-fit allocation of channel numbers: always pick the
1132 * lowest unused one. To do this, binary-search using the
1133 * counted B-tree to find the largest channel ID which is in a
1134 * contiguous sequence from the beginning. (Precisely
1135 * everything in that sequence must have ID equal to its tree
1136 * index plus CHANNEL_NUMBER_OFFSET.)
1138 tsize = count234(ssh->channels);
1142 while (high - low > 1) {
1143 mid = (high + low) / 2;
1144 c = index234(ssh->channels, mid);
1145 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1146 low = mid; /* this one is fine */
1148 high = mid; /* this one is past it */
1151 * Now low points to either -1, or the tree index of the
1152 * largest ID in the initial sequence.
1155 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1156 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1158 return low + 1 + CHANNEL_NUMBER_OFFSET;
1161 static void c_write_stderr(int trusted, const char *buf, int len)
1164 for (i = 0; i < len; i++)
1165 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1166 fputc(buf[i], stderr);
1169 static void c_write(Ssh ssh, const char *buf, int len)
1171 if (flags & FLAG_STDERR)
1172 c_write_stderr(1, buf, len);
1174 from_backend(ssh->frontend, 1, buf, len);
1177 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1179 if (flags & FLAG_STDERR)
1180 c_write_stderr(0, buf, len);
1182 from_backend_untrusted(ssh->frontend, buf, len);
1185 static void c_write_str(Ssh ssh, const char *buf)
1187 c_write(ssh, buf, strlen(buf));
1190 static void ssh_free_packet(struct Packet *pkt)
1195 static struct Packet *ssh_new_packet(void)
1197 struct Packet *pkt = snew(struct Packet);
1199 pkt->body = pkt->data = NULL;
1205 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1208 struct logblank_t blanks[4];
1214 if (ssh->logomitdata &&
1215 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1216 pkt->type == SSH1_SMSG_STDERR_DATA ||
1217 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1218 /* "Session data" packets - omit the data string. */
1219 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1220 ssh_pkt_getuint32(pkt); /* skip channel id */
1221 blanks[nblanks].offset = pkt->savedpos + 4;
1222 blanks[nblanks].type = PKTLOG_OMIT;
1223 ssh_pkt_getstring(pkt, &str, &slen);
1225 blanks[nblanks].len = slen;
1229 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1230 ssh1_pkt_type(pkt->type),
1231 pkt->body, pkt->length, nblanks, blanks, NULL,
1235 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1238 struct logblank_t blanks[4];
1243 * For outgoing packets, pkt->length represents the length of the
1244 * whole packet starting at pkt->data (including some header), and
1245 * pkt->body refers to the point within that where the log-worthy
1246 * payload begins. However, incoming packets expect pkt->length to
1247 * represent only the payload length (that is, it's measured from
1248 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1249 * packet to conform to the incoming-packet semantics, so that we
1250 * can analyse it with the ssh_pkt_get functions.
1252 pkt->length -= (pkt->body - pkt->data);
1255 if (ssh->logomitdata &&
1256 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1257 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1258 /* "Session data" packets - omit the data string. */
1259 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1260 ssh_pkt_getuint32(pkt); /* skip channel id */
1261 blanks[nblanks].offset = pkt->savedpos + 4;
1262 blanks[nblanks].type = PKTLOG_OMIT;
1263 ssh_pkt_getstring(pkt, &str, &slen);
1265 blanks[nblanks].len = slen;
1270 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1271 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1272 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1273 conf_get_int(ssh->conf, CONF_logomitpass)) {
1274 /* If this is a password or similar packet, blank the password(s). */
1275 blanks[nblanks].offset = 0;
1276 blanks[nblanks].len = pkt->length;
1277 blanks[nblanks].type = PKTLOG_BLANK;
1279 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1280 conf_get_int(ssh->conf, CONF_logomitpass)) {
1282 * If this is an X forwarding request packet, blank the fake
1285 * Note that while we blank the X authentication data here, we
1286 * don't take any special action to blank the start of an X11
1287 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1288 * an X connection without having session blanking enabled is
1289 * likely to leak your cookie into the log.
1292 ssh_pkt_getstring(pkt, &str, &slen);
1293 blanks[nblanks].offset = pkt->savedpos;
1294 blanks[nblanks].type = PKTLOG_BLANK;
1295 ssh_pkt_getstring(pkt, &str, &slen);
1297 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1302 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1303 ssh1_pkt_type(pkt->data[12]),
1304 pkt->body, pkt->length,
1305 nblanks, blanks, NULL, 0, NULL);
1308 * Undo the above adjustment of pkt->length, to put the packet
1309 * back in the state we found it.
1311 pkt->length += (pkt->body - pkt->data);
1315 * Collect incoming data in the incoming packet buffer.
1316 * Decipher and verify the packet when it is completely read.
1317 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1318 * Update the *data and *datalen variables.
1319 * Return a Packet structure when a packet is completed.
1321 static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data,
1324 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1326 crBegin(ssh->ssh1_rdpkt_crstate);
1328 st->pktin = ssh_new_packet();
1330 st->pktin->type = 0;
1331 st->pktin->length = 0;
1333 for (st->i = st->len = 0; st->i < 4; st->i++) {
1334 while ((*datalen) == 0)
1336 st->len = (st->len << 8) + **data;
1337 (*data)++, (*datalen)--;
1340 st->pad = 8 - (st->len % 8);
1341 st->biglen = st->len + st->pad;
1342 st->pktin->length = st->len - 5;
1344 if (st->biglen < 0) {
1345 bombout(("Extremely large packet length from server suggests"
1346 " data stream corruption"));
1347 ssh_free_packet(st->pktin);
1351 st->pktin->maxlen = st->biglen;
1352 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1354 st->to_read = st->biglen;
1355 st->p = st->pktin->data;
1356 while (st->to_read > 0) {
1357 st->chunk = st->to_read;
1358 while ((*datalen) == 0)
1360 if (st->chunk > (*datalen))
1361 st->chunk = (*datalen);
1362 memcpy(st->p, *data, st->chunk);
1364 *datalen -= st->chunk;
1366 st->to_read -= st->chunk;
1369 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1370 st->biglen, NULL)) {
1371 bombout(("Network attack (CRC compensation) detected!"));
1372 ssh_free_packet(st->pktin);
1377 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1379 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1380 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1381 if (st->gotcrc != st->realcrc) {
1382 bombout(("Incorrect CRC received on packet"));
1383 ssh_free_packet(st->pktin);
1387 st->pktin->body = st->pktin->data + st->pad + 1;
1389 if (ssh->v1_compressing) {
1390 unsigned char *decompblk;
1392 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1393 st->pktin->body - 1, st->pktin->length + 1,
1394 &decompblk, &decomplen)) {
1395 bombout(("Zlib decompression encountered invalid data"));
1396 ssh_free_packet(st->pktin);
1400 if (st->pktin->maxlen < st->pad + decomplen) {
1401 st->pktin->maxlen = st->pad + decomplen;
1402 st->pktin->data = sresize(st->pktin->data,
1403 st->pktin->maxlen + APIEXTRA,
1405 st->pktin->body = st->pktin->data + st->pad + 1;
1408 memcpy(st->pktin->body - 1, decompblk, decomplen);
1410 st->pktin->length = decomplen - 1;
1413 st->pktin->type = st->pktin->body[-1];
1416 * Now pktin->body and pktin->length identify the semantic content
1417 * of the packet, excluding the initial type byte.
1421 ssh1_log_incoming_packet(ssh, st->pktin);
1423 st->pktin->savedpos = 0;
1425 crFinish(st->pktin);
1428 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1431 struct logblank_t blanks[4];
1437 if (ssh->logomitdata &&
1438 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1439 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1440 /* "Session data" packets - omit the data string. */
1441 ssh_pkt_getuint32(pkt); /* skip channel id */
1442 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1443 ssh_pkt_getuint32(pkt); /* skip extended data type */
1444 blanks[nblanks].offset = pkt->savedpos + 4;
1445 blanks[nblanks].type = PKTLOG_OMIT;
1446 ssh_pkt_getstring(pkt, &str, &slen);
1448 blanks[nblanks].len = slen;
1453 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1454 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1455 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1459 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1462 struct logblank_t blanks[4];
1467 * For outgoing packets, pkt->length represents the length of the
1468 * whole packet starting at pkt->data (including some header), and
1469 * pkt->body refers to the point within that where the log-worthy
1470 * payload begins. However, incoming packets expect pkt->length to
1471 * represent only the payload length (that is, it's measured from
1472 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1473 * packet to conform to the incoming-packet semantics, so that we
1474 * can analyse it with the ssh_pkt_get functions.
1476 pkt->length -= (pkt->body - pkt->data);
1479 if (ssh->logomitdata &&
1480 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1481 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1482 /* "Session data" packets - omit the data string. */
1483 ssh_pkt_getuint32(pkt); /* skip channel id */
1484 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1485 ssh_pkt_getuint32(pkt); /* skip extended data type */
1486 blanks[nblanks].offset = pkt->savedpos + 4;
1487 blanks[nblanks].type = PKTLOG_OMIT;
1488 ssh_pkt_getstring(pkt, &str, &slen);
1490 blanks[nblanks].len = slen;
1495 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1496 conf_get_int(ssh->conf, CONF_logomitpass)) {
1497 /* If this is a password packet, blank the password(s). */
1499 ssh_pkt_getstring(pkt, &str, &slen);
1500 ssh_pkt_getstring(pkt, &str, &slen);
1501 ssh_pkt_getstring(pkt, &str, &slen);
1502 if (slen == 8 && !memcmp(str, "password", 8)) {
1503 ssh2_pkt_getbool(pkt);
1504 /* Blank the password field. */
1505 blanks[nblanks].offset = pkt->savedpos;
1506 blanks[nblanks].type = PKTLOG_BLANK;
1507 ssh_pkt_getstring(pkt, &str, &slen);
1509 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1511 /* If there's another password field beyond it (change of
1512 * password), blank that too. */
1513 ssh_pkt_getstring(pkt, &str, &slen);
1515 blanks[nblanks-1].len =
1516 pkt->savedpos - blanks[nblanks].offset;
1519 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1520 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1521 conf_get_int(ssh->conf, CONF_logomitpass)) {
1522 /* If this is a keyboard-interactive response packet, blank
1525 ssh_pkt_getuint32(pkt);
1526 blanks[nblanks].offset = pkt->savedpos;
1527 blanks[nblanks].type = PKTLOG_BLANK;
1529 ssh_pkt_getstring(pkt, &str, &slen);
1533 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1535 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1536 conf_get_int(ssh->conf, CONF_logomitpass)) {
1538 * If this is an X forwarding request packet, blank the fake
1541 * Note that while we blank the X authentication data here, we
1542 * don't take any special action to blank the start of an X11
1543 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1544 * an X connection without having session blanking enabled is
1545 * likely to leak your cookie into the log.
1548 ssh_pkt_getuint32(pkt);
1549 ssh_pkt_getstring(pkt, &str, &slen);
1550 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1551 ssh2_pkt_getbool(pkt);
1552 ssh2_pkt_getbool(pkt);
1553 ssh_pkt_getstring(pkt, &str, &slen);
1554 blanks[nblanks].offset = pkt->savedpos;
1555 blanks[nblanks].type = PKTLOG_BLANK;
1556 ssh_pkt_getstring(pkt, &str, &slen);
1558 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1564 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1565 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1566 pkt->body, pkt->length, nblanks, blanks,
1567 &ssh->v2_outgoing_sequence,
1568 pkt->downstream_id, pkt->additional_log_text);
1571 * Undo the above adjustment of pkt->length, to put the packet
1572 * back in the state we found it.
1574 pkt->length += (pkt->body - pkt->data);
1577 static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data,
1580 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1582 crBegin(ssh->ssh2_rdpkt_crstate);
1584 st->pktin = ssh_new_packet();
1586 st->pktin->type = 0;
1587 st->pktin->length = 0;
1589 st->cipherblk = ssh->sccipher->blksize;
1592 if (st->cipherblk < 8)
1594 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1596 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1597 ssh->scmac && !ssh->scmac_etm) {
1599 * When dealing with a CBC-mode cipher, we want to avoid the
1600 * possibility of an attacker's tweaking the ciphertext stream
1601 * so as to cause us to feed the same block to the block
1602 * cipher more than once and thus leak information
1603 * (VU#958563). The way we do this is not to take any
1604 * decisions on the basis of anything we've decrypted until
1605 * we've verified it with a MAC. That includes the packet
1606 * length, so we just read data and check the MAC repeatedly,
1607 * and when the MAC passes, see if the length we've got is
1610 * This defence is unnecessary in OpenSSH ETM mode, because
1611 * the whole point of ETM mode is that the attacker can't
1612 * tweak the ciphertext stream at all without the MAC
1613 * detecting it before we decrypt anything.
1616 /* May as well allocate the whole lot now. */
1617 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1620 /* Read an amount corresponding to the MAC. */
1621 for (st->i = 0; st->i < st->maclen; st->i++) {
1622 while ((*datalen) == 0)
1624 st->pktin->data[st->i] = *(*data)++;
1630 unsigned char seq[4];
1631 ssh->scmac->start(ssh->sc_mac_ctx);
1632 PUT_32BIT(seq, st->incoming_sequence);
1633 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1636 for (;;) { /* Once around this loop per cipher block. */
1637 /* Read another cipher-block's worth, and tack it onto the end. */
1638 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1639 while ((*datalen) == 0)
1641 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1644 /* Decrypt one more block (a little further back in the stream). */
1645 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1646 st->pktin->data + st->packetlen,
1648 /* Feed that block to the MAC. */
1649 ssh->scmac->bytes(ssh->sc_mac_ctx,
1650 st->pktin->data + st->packetlen, st->cipherblk);
1651 st->packetlen += st->cipherblk;
1652 /* See if that gives us a valid packet. */
1653 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1654 st->pktin->data + st->packetlen) &&
1655 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1658 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1659 bombout(("No valid incoming packet found"));
1660 ssh_free_packet(st->pktin);
1664 st->pktin->maxlen = st->packetlen + st->maclen;
1665 st->pktin->data = sresize(st->pktin->data,
1666 st->pktin->maxlen + APIEXTRA,
1668 } else if (ssh->scmac && ssh->scmac_etm) {
1669 st->pktin->data = snewn(4 + APIEXTRA, unsigned char);
1672 * OpenSSH encrypt-then-MAC mode: the packet length is
1673 * unencrypted, unless the cipher supports length encryption.
1675 for (st->i = st->len = 0; st->i < 4; st->i++) {
1676 while ((*datalen) == 0)
1678 st->pktin->data[st->i] = *(*data)++;
1681 /* Cipher supports length decryption, so do it */
1682 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
1683 /* Keep the packet the same though, so the MAC passes */
1684 unsigned char len[4];
1685 memcpy(len, st->pktin->data, 4);
1686 ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence);
1687 st->len = toint(GET_32BIT(len));
1689 st->len = toint(GET_32BIT(st->pktin->data));
1693 * _Completely_ silly lengths should be stomped on before they
1694 * do us any more damage.
1696 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1697 st->len % st->cipherblk != 0) {
1698 bombout(("Incoming packet length field was garbled"));
1699 ssh_free_packet(st->pktin);
1704 * So now we can work out the total packet length.
1706 st->packetlen = st->len + 4;
1709 * Allocate memory for the rest of the packet.
1711 st->pktin->maxlen = st->packetlen + st->maclen;
1712 st->pktin->data = sresize(st->pktin->data,
1713 st->pktin->maxlen + APIEXTRA,
1717 * Read the remainder of the packet.
1719 for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) {
1720 while ((*datalen) == 0)
1722 st->pktin->data[st->i] = *(*data)++;
1730 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1731 st->len + 4, st->incoming_sequence)) {
1732 bombout(("Incorrect MAC received on packet"));
1733 ssh_free_packet(st->pktin);
1737 /* Decrypt everything between the length field and the MAC. */
1739 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1740 st->pktin->data + 4,
1743 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1746 * Acquire and decrypt the first block of the packet. This will
1747 * contain the length and padding details.
1749 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1750 while ((*datalen) == 0)
1752 st->pktin->data[st->i] = *(*data)++;
1757 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1758 st->pktin->data, st->cipherblk);
1761 * Now get the length figure.
1763 st->len = toint(GET_32BIT(st->pktin->data));
1766 * _Completely_ silly lengths should be stomped on before they
1767 * do us any more damage.
1769 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1770 (st->len + 4) % st->cipherblk != 0) {
1771 bombout(("Incoming packet was garbled on decryption"));
1772 ssh_free_packet(st->pktin);
1777 * So now we can work out the total packet length.
1779 st->packetlen = st->len + 4;
1782 * Allocate memory for the rest of the packet.
1784 st->pktin->maxlen = st->packetlen + st->maclen;
1785 st->pktin->data = sresize(st->pktin->data,
1786 st->pktin->maxlen + APIEXTRA,
1790 * Read and decrypt the remainder of the packet.
1792 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1794 while ((*datalen) == 0)
1796 st->pktin->data[st->i] = *(*data)++;
1799 /* Decrypt everything _except_ the MAC. */
1801 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1802 st->pktin->data + st->cipherblk,
1803 st->packetlen - st->cipherblk);
1809 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1810 st->len + 4, st->incoming_sequence)) {
1811 bombout(("Incorrect MAC received on packet"));
1812 ssh_free_packet(st->pktin);
1816 /* Get and sanity-check the amount of random padding. */
1817 st->pad = st->pktin->data[4];
1818 if (st->pad < 4 || st->len - st->pad < 1) {
1819 bombout(("Invalid padding length on received packet"));
1820 ssh_free_packet(st->pktin);
1824 * This enables us to deduce the payload length.
1826 st->payload = st->len - st->pad - 1;
1828 st->pktin->length = st->payload + 5;
1829 st->pktin->encrypted_len = st->packetlen;
1831 st->pktin->sequence = st->incoming_sequence++;
1833 st->pktin->length = st->packetlen - st->pad;
1834 assert(st->pktin->length >= 0);
1837 * Decompress packet payload.
1840 unsigned char *newpayload;
1843 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1844 st->pktin->data + 5, st->pktin->length - 5,
1845 &newpayload, &newlen)) {
1846 if (st->pktin->maxlen < newlen + 5) {
1847 st->pktin->maxlen = newlen + 5;
1848 st->pktin->data = sresize(st->pktin->data,
1849 st->pktin->maxlen + APIEXTRA,
1852 st->pktin->length = 5 + newlen;
1853 memcpy(st->pktin->data + 5, newpayload, newlen);
1859 * RFC 4253 doesn't explicitly say that completely empty packets
1860 * with no type byte are forbidden, so treat them as deserving
1861 * an SSH_MSG_UNIMPLEMENTED.
1863 if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */
1864 ssh2_msg_something_unimplemented(ssh, st->pktin);
1868 * pktin->body and pktin->length should identify the semantic
1869 * content of the packet, excluding the initial type byte.
1871 st->pktin->type = st->pktin->data[5];
1872 st->pktin->body = st->pktin->data + 6;
1873 st->pktin->length -= 6;
1874 assert(st->pktin->length >= 0); /* one last double-check */
1877 ssh2_log_incoming_packet(ssh, st->pktin);
1879 st->pktin->savedpos = 0;
1881 crFinish(st->pktin);
1884 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh,
1885 const unsigned char **data,
1888 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1890 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1893 * Read the packet length field.
1895 for (st->i = 0; st->i < 4; st->i++) {
1896 while ((*datalen) == 0)
1898 st->length[st->i] = *(*data)++;
1902 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1903 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1904 bombout(("Invalid packet length received"));
1908 st->pktin = ssh_new_packet();
1909 st->pktin->data = snewn(st->packetlen, unsigned char);
1911 st->pktin->encrypted_len = st->packetlen;
1913 st->pktin->sequence = st->incoming_sequence++;
1916 * Read the remainder of the packet.
1918 for (st->i = 0; st->i < st->packetlen; st->i++) {
1919 while ((*datalen) == 0)
1921 st->pktin->data[st->i] = *(*data)++;
1926 * pktin->body and pktin->length should identify the semantic
1927 * content of the packet, excluding the initial type byte.
1929 st->pktin->type = st->pktin->data[0];
1930 st->pktin->body = st->pktin->data + 1;
1931 st->pktin->length = st->packetlen - 1;
1934 * Log incoming packet, possibly omitting sensitive fields.
1937 ssh2_log_incoming_packet(ssh, st->pktin);
1939 st->pktin->savedpos = 0;
1941 crFinish(st->pktin);
1944 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1946 int pad, biglen, i, pktoffs;
1950 * XXX various versions of SC (including 8.8.4) screw up the
1951 * register allocation in this function and use the same register
1952 * (D6) for len and as a temporary, with predictable results. The
1953 * following sledgehammer prevents this.
1960 ssh1_log_outgoing_packet(ssh, pkt);
1962 if (ssh->v1_compressing) {
1963 unsigned char *compblk;
1965 zlib_compress_block(ssh->cs_comp_ctx,
1966 pkt->data + 12, pkt->length - 12,
1967 &compblk, &complen);
1968 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1969 memcpy(pkt->data + 12, compblk, complen);
1971 pkt->length = complen + 12;
1974 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1976 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1977 pad = 8 - (len % 8);
1979 biglen = len + pad; /* len(padding+type+data+CRC) */
1981 for (i = pktoffs; i < 4+8; i++)
1982 pkt->data[i] = random_byte();
1983 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1984 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1985 PUT_32BIT(pkt->data + pktoffs, len);
1988 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1989 pkt->data + pktoffs + 4, biglen);
1991 if (offset_p) *offset_p = pktoffs;
1992 return biglen + 4; /* len(length+padding+type+data+CRC) */
1995 static int s_write(Ssh ssh, void *data, int len)
1998 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1999 0, NULL, NULL, 0, NULL);
2002 return sk_write(ssh->s, (char *)data, len);
2005 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
2007 int len, backlog, offset;
2008 len = s_wrpkt_prepare(ssh, pkt, &offset);
2009 backlog = s_write(ssh, pkt->data + offset, len);
2010 if (backlog > SSH_MAX_BACKLOG)
2011 ssh_throttle_all(ssh, 1, backlog);
2012 ssh_free_packet(pkt);
2015 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
2018 len = s_wrpkt_prepare(ssh, pkt, &offset);
2019 if (ssh->deferred_len + len > ssh->deferred_size) {
2020 ssh->deferred_size = ssh->deferred_len + len + 128;
2021 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2025 memcpy(ssh->deferred_send_data + ssh->deferred_len,
2026 pkt->data + offset, len);
2027 ssh->deferred_len += len;
2028 ssh_free_packet(pkt);
2032 * Construct a SSH-1 packet with the specified contents.
2033 * (This all-at-once interface used to be the only one, but now SSH-1
2034 * packets can also be constructed incrementally.)
2036 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
2042 pkt = ssh1_pkt_init(pkttype);
2044 while ((argtype = va_arg(ap, int)) != PKT_END) {
2045 unsigned char *argp, argchar;
2047 unsigned long argint;
2050 /* Actual fields in the packet */
2052 argint = va_arg(ap, int);
2053 ssh_pkt_adduint32(pkt, argint);
2056 argchar = (unsigned char) va_arg(ap, int);
2057 ssh_pkt_addbyte(pkt, argchar);
2060 argp = va_arg(ap, unsigned char *);
2061 arglen = va_arg(ap, int);
2062 ssh_pkt_adddata(pkt, argp, arglen);
2065 sargp = va_arg(ap, char *);
2066 ssh_pkt_addstring(pkt, sargp);
2069 bn = va_arg(ap, Bignum);
2070 ssh1_pkt_addmp(pkt, bn);
2078 static void send_packet(Ssh ssh, int pkttype, ...)
2082 va_start(ap, pkttype);
2083 pkt = construct_packet(ssh, pkttype, ap);
2088 static void defer_packet(Ssh ssh, int pkttype, ...)
2092 va_start(ap, pkttype);
2093 pkt = construct_packet(ssh, pkttype, ap);
2095 s_wrpkt_defer(ssh, pkt);
2098 static int ssh_versioncmp(const char *a, const char *b)
2101 unsigned long av, bv;
2103 av = strtoul(a, &ae, 10);
2104 bv = strtoul(b, &be, 10);
2106 return (av < bv ? -1 : +1);
2111 av = strtoul(ae, &ae, 10);
2112 bv = strtoul(be, &be, 10);
2114 return (av < bv ? -1 : +1);
2119 * Utility routines for putting an SSH-protocol `string' and
2120 * `uint32' into a hash state.
2122 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
2124 unsigned char lenblk[4];
2125 PUT_32BIT(lenblk, len);
2126 h->bytes(s, lenblk, 4);
2127 h->bytes(s, str, len);
2130 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2132 unsigned char intblk[4];
2133 PUT_32BIT(intblk, i);
2134 h->bytes(s, intblk, 4);
2138 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2140 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2142 if (pkt->maxlen < length) {
2143 unsigned char *body = pkt->body;
2144 int offset = body ? body - pkt->data : 0;
2145 pkt->maxlen = length + 256;
2146 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2147 if (body) pkt->body = pkt->data + offset;
2150 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2153 ssh_pkt_ensure(pkt, pkt->length);
2154 memcpy(pkt->data + pkt->length - len, data, len);
2156 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2158 ssh_pkt_adddata(pkt, &byte, 1);
2160 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2162 ssh_pkt_adddata(pkt, &value, 1);
2164 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2167 PUT_32BIT(x, value);
2168 ssh_pkt_adddata(pkt, x, 4);
2170 static void ssh_pkt_addstring_start(struct Packet *pkt)
2172 ssh_pkt_adduint32(pkt, 0);
2173 pkt->savedpos = pkt->length;
2175 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2178 ssh_pkt_adddata(pkt, data, len);
2179 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2181 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2183 ssh_pkt_addstring_data(pkt, data, strlen(data));
2185 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2187 ssh_pkt_addstring_start(pkt);
2188 ssh_pkt_addstring_str(pkt, data);
2190 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2192 int len = ssh1_bignum_length(b);
2193 unsigned char *data = snewn(len, unsigned char);
2194 (void) ssh1_write_bignum(data, b);
2195 ssh_pkt_adddata(pkt, data, len);
2198 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2201 int i, n = (bignum_bitcount(b) + 7) / 8;
2202 p = snewn(n + 1, unsigned char);
2204 for (i = 1; i <= n; i++)
2205 p[i] = bignum_byte(b, n - i);
2207 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2209 memmove(p, p + i, n + 1 - i);
2213 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2217 p = ssh2_mpint_fmt(b, &len);
2218 ssh_pkt_addstring_start(pkt);
2219 ssh_pkt_addstring_data(pkt, (char *)p, len);
2223 static struct Packet *ssh1_pkt_init(int pkt_type)
2225 struct Packet *pkt = ssh_new_packet();
2226 pkt->length = 4 + 8; /* space for length + max padding */
2227 ssh_pkt_addbyte(pkt, pkt_type);
2228 pkt->body = pkt->data + pkt->length;
2229 pkt->type = pkt_type;
2230 pkt->downstream_id = 0;
2231 pkt->additional_log_text = NULL;
2235 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2236 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2237 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2238 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2239 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2240 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2241 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2242 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2243 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2245 static struct Packet *ssh2_pkt_init(int pkt_type)
2247 struct Packet *pkt = ssh_new_packet();
2248 pkt->length = 5; /* space for packet length + padding length */
2250 pkt->type = pkt_type;
2251 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2252 pkt->body = pkt->data + pkt->length; /* after packet type */
2253 pkt->downstream_id = 0;
2254 pkt->additional_log_text = NULL;
2259 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2260 * put the MAC on it. Final packet, ready to be sent, is stored in
2261 * pkt->data. Total length is returned.
2263 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2265 int cipherblk, maclen, padding, unencrypted_prefix, i;
2268 ssh2_log_outgoing_packet(ssh, pkt);
2270 if (ssh->bare_connection) {
2272 * Trivial packet construction for the bare connection
2275 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2276 pkt->body = pkt->data + 1;
2277 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2278 return pkt->length - 1;
2282 * Compress packet payload.
2285 unsigned char *newpayload;
2288 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2290 &newpayload, &newlen)) {
2292 ssh2_pkt_adddata(pkt, newpayload, newlen);
2298 * Add padding. At least four bytes, and must also bring total
2299 * length (minus MAC) up to a multiple of the block size.
2300 * If pkt->forcepad is set, make sure the packet is at least that size
2303 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2304 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2306 unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0;
2307 if (pkt->length + padding < pkt->forcepad)
2308 padding = pkt->forcepad - pkt->length;
2310 (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk)
2312 assert(padding <= 255);
2313 maclen = ssh->csmac ? ssh->csmac->len : 0;
2314 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2315 pkt->data[4] = padding;
2316 for (i = 0; i < padding; i++)
2317 pkt->data[pkt->length + i] = random_byte();
2318 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2320 /* Encrypt length if the scheme requires it */
2321 if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) {
2322 ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4,
2323 ssh->v2_outgoing_sequence);
2326 if (ssh->csmac && ssh->csmac_etm) {
2328 * OpenSSH-defined encrypt-then-MAC protocol.
2331 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2332 pkt->data + 4, pkt->length + padding - 4);
2333 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2334 pkt->length + padding,
2335 ssh->v2_outgoing_sequence);
2338 * SSH-2 standard protocol.
2341 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2342 pkt->length + padding,
2343 ssh->v2_outgoing_sequence);
2345 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2346 pkt->data, pkt->length + padding);
2349 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2350 pkt->encrypted_len = pkt->length + padding;
2352 /* Ready-to-send packet starts at pkt->data. We return length. */
2353 pkt->body = pkt->data;
2354 return pkt->length + padding + maclen;
2358 * Routines called from the main SSH code to send packets. There
2359 * are quite a few of these, because we have two separate
2360 * mechanisms for delaying the sending of packets:
2362 * - In order to send an IGNORE message and a password message in
2363 * a single fixed-length blob, we require the ability to
2364 * concatenate the encrypted forms of those two packets _into_ a
2365 * single blob and then pass it to our <network.h> transport
2366 * layer in one go. Hence, there's a deferment mechanism which
2367 * works after packet encryption.
2369 * - In order to avoid sending any connection-layer messages
2370 * during repeat key exchange, we have to queue up any such
2371 * outgoing messages _before_ they are encrypted (and in
2372 * particular before they're allocated sequence numbers), and
2373 * then send them once we've finished.
2375 * I call these mechanisms `defer' and `queue' respectively, so as
2376 * to distinguish them reasonably easily.
2378 * The functions send_noqueue() and defer_noqueue() free the packet
2379 * structure they are passed. Every outgoing packet goes through
2380 * precisely one of these functions in its life; packets passed to
2381 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2382 * these or get queued, and then when the queue is later emptied
2383 * the packets are all passed to defer_noqueue().
2385 * When using a CBC-mode cipher, it's necessary to ensure that an
2386 * attacker can't provide data to be encrypted using an IV that they
2387 * know. We ensure this by prefixing each packet that might contain
2388 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2389 * mechanism, so in this case send_noqueue() ends up redirecting to
2390 * defer_noqueue(). If you don't like this inefficiency, don't use
2394 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2395 static void ssh_pkt_defersend(Ssh);
2398 * Send an SSH-2 packet immediately, without queuing or deferring.
2400 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2404 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2405 /* We need to send two packets, so use the deferral mechanism. */
2406 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2407 ssh_pkt_defersend(ssh);
2410 len = ssh2_pkt_construct(ssh, pkt);
2411 backlog = s_write(ssh, pkt->body, len);
2412 if (backlog > SSH_MAX_BACKLOG)
2413 ssh_throttle_all(ssh, 1, backlog);
2415 ssh->outgoing_data_size += pkt->encrypted_len;
2416 if (!ssh->kex_in_progress &&
2417 !ssh->bare_connection &&
2418 ssh->max_data_size != 0 &&
2419 ssh->outgoing_data_size > ssh->max_data_size)
2420 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2422 ssh_free_packet(pkt);
2426 * Defer an SSH-2 packet.
2428 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2431 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2432 ssh->deferred_len == 0 && !noignore &&
2433 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2435 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2436 * get encrypted with a known IV.
2438 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2439 ssh2_pkt_addstring_start(ipkt);
2440 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2442 len = ssh2_pkt_construct(ssh, pkt);
2443 if (ssh->deferred_len + len > ssh->deferred_size) {
2444 ssh->deferred_size = ssh->deferred_len + len + 128;
2445 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2449 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2450 ssh->deferred_len += len;
2451 ssh->deferred_data_size += pkt->encrypted_len;
2452 ssh_free_packet(pkt);
2456 * Queue an SSH-2 packet.
2458 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2460 assert(ssh->queueing);
2462 if (ssh->queuelen >= ssh->queuesize) {
2463 ssh->queuesize = ssh->queuelen + 32;
2464 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2467 ssh->queue[ssh->queuelen++] = pkt;
2471 * Either queue or send a packet, depending on whether queueing is
2474 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2477 ssh2_pkt_queue(ssh, pkt);
2479 ssh2_pkt_send_noqueue(ssh, pkt);
2483 * Either queue or defer a packet, depending on whether queueing is
2486 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2489 ssh2_pkt_queue(ssh, pkt);
2491 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2495 * Send the whole deferred data block constructed by
2496 * ssh2_pkt_defer() or SSH-1's defer_packet().
2498 * The expected use of the defer mechanism is that you call
2499 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2500 * not currently queueing, this simply sets up deferred_send_data
2501 * and then sends it. If we _are_ currently queueing, the calls to
2502 * ssh2_pkt_defer() put the deferred packets on to the queue
2503 * instead, and therefore ssh_pkt_defersend() has no deferred data
2504 * to send. Hence, there's no need to make it conditional on
2507 static void ssh_pkt_defersend(Ssh ssh)
2510 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2511 ssh->deferred_len = ssh->deferred_size = 0;
2512 sfree(ssh->deferred_send_data);
2513 ssh->deferred_send_data = NULL;
2514 if (backlog > SSH_MAX_BACKLOG)
2515 ssh_throttle_all(ssh, 1, backlog);
2517 ssh->outgoing_data_size += ssh->deferred_data_size;
2518 if (!ssh->kex_in_progress &&
2519 !ssh->bare_connection &&
2520 ssh->max_data_size != 0 &&
2521 ssh->outgoing_data_size > ssh->max_data_size)
2522 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2523 ssh->deferred_data_size = 0;
2527 * Send a packet whose length needs to be disguised (typically
2528 * passwords or keyboard-interactive responses).
2530 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2536 * The simplest way to do this is to adjust the
2537 * variable-length padding field in the outgoing packet.
2539 * Currently compiled out, because some Cisco SSH servers
2540 * don't like excessively padded packets (bah, why's it
2543 pkt->forcepad = padsize;
2544 ssh2_pkt_send(ssh, pkt);
2549 * If we can't do that, however, an alternative approach is
2550 * to use the pkt_defer mechanism to bundle the packet
2551 * tightly together with an SSH_MSG_IGNORE such that their
2552 * combined length is a constant. So first we construct the
2553 * final form of this packet and defer its sending.
2555 ssh2_pkt_defer(ssh, pkt);
2558 * Now construct an SSH_MSG_IGNORE which includes a string
2559 * that's an exact multiple of the cipher block size. (If
2560 * the cipher is NULL so that the block size is
2561 * unavailable, we don't do this trick at all, because we
2562 * gain nothing by it.)
2564 if (ssh->cscipher &&
2565 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2568 stringlen = (256 - ssh->deferred_len);
2569 stringlen += ssh->cscipher->blksize - 1;
2570 stringlen -= (stringlen % ssh->cscipher->blksize);
2573 * Temporarily disable actual compression, so we
2574 * can guarantee to get this string exactly the
2575 * length we want it. The compression-disabling
2576 * routine should return an integer indicating how
2577 * many bytes we should adjust our string length
2581 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2583 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2584 ssh2_pkt_addstring_start(pkt);
2585 for (i = 0; i < stringlen; i++) {
2586 char c = (char) random_byte();
2587 ssh2_pkt_addstring_data(pkt, &c, 1);
2589 ssh2_pkt_defer(ssh, pkt);
2591 ssh_pkt_defersend(ssh);
2596 * Send all queued SSH-2 packets. We send them by means of
2597 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2598 * packets that needed to be lumped together.
2600 static void ssh2_pkt_queuesend(Ssh ssh)
2604 assert(!ssh->queueing);
2606 for (i = 0; i < ssh->queuelen; i++)
2607 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2610 ssh_pkt_defersend(ssh);
2614 void bndebug(char *string, Bignum b)
2618 p = ssh2_mpint_fmt(b, &len);
2619 debug(("%s", string));
2620 for (i = 0; i < len; i++)
2621 debug((" %02x", p[i]));
2627 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2631 p = ssh2_mpint_fmt(b, &len);
2632 hash_string(h, s, p, len);
2637 * Packet decode functions for both SSH-1 and SSH-2.
2639 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2641 unsigned long value;
2642 if (pkt->length - pkt->savedpos < 4)
2643 return 0; /* arrgh, no way to decline (FIXME?) */
2644 value = GET_32BIT(pkt->body + pkt->savedpos);
2648 static int ssh2_pkt_getbool(struct Packet *pkt)
2650 unsigned long value;
2651 if (pkt->length - pkt->savedpos < 1)
2652 return 0; /* arrgh, no way to decline (FIXME?) */
2653 value = pkt->body[pkt->savedpos] != 0;
2657 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2662 if (pkt->length - pkt->savedpos < 4)
2664 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2669 if (pkt->length - pkt->savedpos < *length)
2671 *p = (char *)(pkt->body + pkt->savedpos);
2672 pkt->savedpos += *length;
2674 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2676 if (pkt->length - pkt->savedpos < length)
2678 pkt->savedpos += length;
2679 return pkt->body + (pkt->savedpos - length);
2681 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2682 const unsigned char **keystr)
2686 j = makekey(pkt->body + pkt->savedpos,
2687 pkt->length - pkt->savedpos,
2694 assert(pkt->savedpos < pkt->length);
2698 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2703 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2704 pkt->length - pkt->savedpos, &b);
2712 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2718 ssh_pkt_getstring(pkt, &p, &length);
2723 b = bignum_from_bytes((unsigned char *)p, length);
2728 * Helper function to add an SSH-2 signature blob to a packet.
2729 * Expects to be shown the public key blob as well as the signature
2730 * blob. Normally works just like ssh2_pkt_addstring, but will
2731 * fiddle with the signature packet if necessary for
2732 * BUG_SSH2_RSA_PADDING.
2734 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2735 void *pkblob_v, int pkblob_len,
2736 void *sigblob_v, int sigblob_len)
2738 unsigned char *pkblob = (unsigned char *)pkblob_v;
2739 unsigned char *sigblob = (unsigned char *)sigblob_v;
2741 /* dmemdump(pkblob, pkblob_len); */
2742 /* dmemdump(sigblob, sigblob_len); */
2745 * See if this is in fact an ssh-rsa signature and a buggy
2746 * server; otherwise we can just do this the easy way.
2748 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2749 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2750 int pos, len, siglen;
2753 * Find the byte length of the modulus.
2756 pos = 4+7; /* skip over "ssh-rsa" */
2757 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2758 if (len < 0 || len > pkblob_len - pos - 4)
2760 pos += 4 + len; /* skip over exponent */
2761 if (pkblob_len - pos < 4)
2763 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2764 if (len < 0 || len > pkblob_len - pos - 4)
2766 pos += 4; /* find modulus itself */
2767 while (len > 0 && pkblob[pos] == 0)
2769 /* debug(("modulus length is %d\n", len)); */
2772 * Now find the signature integer.
2774 pos = 4+7; /* skip over "ssh-rsa" */
2775 if (sigblob_len < pos+4)
2777 siglen = toint(GET_32BIT(sigblob+pos));
2778 if (siglen != sigblob_len - pos - 4)
2780 /* debug(("signature length is %d\n", siglen)); */
2782 if (len != siglen) {
2783 unsigned char newlen[4];
2784 ssh2_pkt_addstring_start(pkt);
2785 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2786 /* dmemdump(sigblob, pos); */
2787 pos += 4; /* point to start of actual sig */
2788 PUT_32BIT(newlen, len);
2789 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2790 /* dmemdump(newlen, 4); */
2792 while (len-- > siglen) {
2793 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2794 /* dmemdump(newlen, 1); */
2796 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2797 /* dmemdump(sigblob+pos, siglen); */
2801 /* Otherwise fall through and do it the easy way. We also come
2802 * here as a fallback if we discover above that the key blob
2803 * is misformatted in some way. */
2807 ssh2_pkt_addstring_start(pkt);
2808 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2812 * Examine the remote side's version string and compare it against
2813 * a list of known buggy implementations.
2815 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2817 char *imp; /* pointer to implementation part */
2819 imp += strcspn(imp, "-");
2821 imp += strcspn(imp, "-");
2824 ssh->remote_bugs = 0;
2827 * General notes on server version strings:
2828 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2829 * here -- in particular, we've heard of one that's perfectly happy
2830 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2831 * so we can't distinguish them.
2833 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2834 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2835 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2836 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2837 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2838 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2840 * These versions don't support SSH1_MSG_IGNORE, so we have
2841 * to use a different defence against password length
2844 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2845 logevent("We believe remote version has SSH-1 ignore bug");
2848 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2849 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2850 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2852 * These versions need a plain password sent; they can't
2853 * handle having a null and a random length of data after
2856 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2857 logevent("We believe remote version needs a plain SSH-1 password");
2860 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2861 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2862 (!strcmp(imp, "Cisco-1.25")))) {
2864 * These versions apparently have no clue whatever about
2865 * RSA authentication and will panic and die if they see
2866 * an AUTH_RSA message.
2868 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2869 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2872 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2873 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2874 !wc_match("* VShell", imp) &&
2875 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2876 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2877 wc_match("2.1 *", imp)))) {
2879 * These versions have the HMAC bug.
2881 ssh->remote_bugs |= BUG_SSH2_HMAC;
2882 logevent("We believe remote version has SSH-2 HMAC bug");
2885 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2886 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2887 !wc_match("* VShell", imp) &&
2888 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2890 * These versions have the key-derivation bug (failing to
2891 * include the literal shared secret in the hashes that
2892 * generate the keys).
2894 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2895 logevent("We believe remote version has SSH-2 key-derivation bug");
2898 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2899 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2900 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2901 wc_match("OpenSSH_3.[0-2]*", imp) ||
2902 wc_match("mod_sftp/0.[0-8]*", imp) ||
2903 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2905 * These versions have the SSH-2 RSA padding bug.
2907 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2908 logevent("We believe remote version has SSH-2 RSA padding bug");
2911 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2912 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2913 wc_match("OpenSSH_2.[0-2]*", imp))) {
2915 * These versions have the SSH-2 session-ID bug in
2916 * public-key authentication.
2918 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2919 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2922 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2923 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2924 (wc_match("DigiSSH_2.0", imp) ||
2925 wc_match("OpenSSH_2.[0-4]*", imp) ||
2926 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2927 wc_match("Sun_SSH_1.0", imp) ||
2928 wc_match("Sun_SSH_1.0.1", imp) ||
2929 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2930 wc_match("WeOnlyDo-*", imp)))) {
2932 * These versions have the SSH-2 rekey bug.
2934 ssh->remote_bugs |= BUG_SSH2_REKEY;
2935 logevent("We believe remote version has SSH-2 rekey bug");
2938 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2939 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2940 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2941 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2943 * This version ignores our makpkt and needs to be throttled.
2945 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2946 logevent("We believe remote version ignores SSH-2 maximum packet size");
2949 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2951 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2952 * none detected automatically.
2954 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2955 logevent("We believe remote version has SSH-2 ignore bug");
2958 if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON ||
2959 (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO &&
2960 (wc_match("OpenSSH_2.[235]*", imp)))) {
2962 * These versions only support the original (pre-RFC4419)
2963 * SSH-2 GEX request, and disconnect with a protocol error if
2964 * we use the newer version.
2966 ssh->remote_bugs |= BUG_SSH2_OLDGEX;
2967 logevent("We believe remote version has outdated SSH-2 GEX");
2970 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2972 * Servers that don't support our winadj request for one
2973 * reason or another. Currently, none detected automatically.
2975 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2976 logevent("We believe remote version has winadj bug");
2979 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2980 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2981 (wc_match("OpenSSH_[2-5].*", imp) ||
2982 wc_match("OpenSSH_6.[0-6]*", imp) ||
2983 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2984 wc_match("dropbear_0.5[01]*", imp)))) {
2986 * These versions have the SSH-2 channel request bug.
2987 * OpenSSH 6.7 and above do not:
2988 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2989 * dropbear_0.52 and above do not:
2990 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2992 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2993 logevent("We believe remote version has SSH-2 channel request bug");
2998 * The `software version' part of an SSH version string is required
2999 * to contain no spaces or minus signs.
3001 static void ssh_fix_verstring(char *str)
3003 /* Eat "<protoversion>-". */
3004 while (*str && *str != '-') str++;
3005 assert(*str == '-'); str++;
3007 /* Convert minus signs and spaces in the remaining string into
3010 if (*str == '-' || *str == ' ')
3017 * Send an appropriate SSH version string.
3019 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
3023 if (ssh->version == 2) {
3025 * Construct a v2 version string.
3027 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
3030 * Construct a v1 version string.
3032 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
3033 verstring = dupprintf("SSH-%s-%s\012",
3034 (ssh_versioncmp(svers, "1.5") <= 0 ?
3039 ssh_fix_verstring(verstring + strlen(protoname));
3041 /* FUZZING make PuTTY insecure, so make live use difficult. */
3045 if (ssh->version == 2) {
3048 * Record our version string.
3050 len = strcspn(verstring, "\015\012");
3051 ssh->v_c = snewn(len + 1, char);
3052 memcpy(ssh->v_c, verstring, len);
3056 logeventf(ssh, "We claim version: %.*s",
3057 strcspn(verstring, "\015\012"), verstring);
3058 s_write(ssh, verstring, strlen(verstring));
3062 static int do_ssh_init(Ssh ssh, unsigned char c)
3064 static const char protoname[] = "SSH-";
3066 struct do_ssh_init_state {
3075 crState(do_ssh_init_state);
3079 /* Search for a line beginning with the protocol name prefix in
3082 for (s->i = 0; protoname[s->i]; s->i++) {
3083 if ((char)c != protoname[s->i]) goto no;
3093 ssh->session_started = TRUE;
3095 s->vstrsize = sizeof(protoname) + 16;
3096 s->vstring = snewn(s->vstrsize, char);
3097 strcpy(s->vstring, protoname);
3098 s->vslen = strlen(protoname);
3101 if (s->vslen >= s->vstrsize - 1) {
3103 s->vstring = sresize(s->vstring, s->vstrsize, char);
3105 s->vstring[s->vslen++] = c;
3108 s->version[s->i] = '\0';
3110 } else if (s->i < sizeof(s->version) - 1)
3111 s->version[s->i++] = c;
3112 } else if (c == '\012')
3114 crReturn(1); /* get another char */
3117 ssh->agentfwd_enabled = FALSE;
3118 ssh->rdpkt2_state.incoming_sequence = 0;
3120 s->vstring[s->vslen] = 0;
3121 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3122 logeventf(ssh, "Server version: %s", s->vstring);
3123 ssh_detect_bugs(ssh, s->vstring);
3126 * Decide which SSH protocol version to support.
3129 /* Anything strictly below "2.0" means protocol 1 is supported. */
3130 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
3131 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
3132 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
3134 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
3135 bombout(("SSH protocol version 1 required by configuration but "
3136 "not provided by server"));
3139 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
3140 bombout(("SSH protocol version 2 required by configuration but "
3141 "not provided by server"));
3145 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
3150 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
3152 /* Send the version string, if we haven't already */
3153 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
3154 ssh_send_verstring(ssh, protoname, s->version);
3156 if (ssh->version == 2) {
3159 * Record their version string.
3161 len = strcspn(s->vstring, "\015\012");
3162 ssh->v_s = snewn(len + 1, char);
3163 memcpy(ssh->v_s, s->vstring, len);
3167 * Initialise SSH-2 protocol.
3169 ssh->protocol = ssh2_protocol;
3170 ssh2_protocol_setup(ssh);
3171 ssh->s_rdpkt = ssh2_rdpkt;
3174 * Initialise SSH-1 protocol.
3176 ssh->protocol = ssh1_protocol;
3177 ssh1_protocol_setup(ssh);
3178 ssh->s_rdpkt = ssh1_rdpkt;
3180 if (ssh->version == 2)
3181 do_ssh2_transport(ssh, NULL, -1, NULL);
3183 update_specials_menu(ssh->frontend);
3184 ssh->state = SSH_STATE_BEFORE_SIZE;
3185 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3192 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3195 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3196 * the ssh-connection part, extracted and given a trivial binary
3197 * packet protocol, so we replace 'SSH-' at the start with a new
3198 * name. In proper SSH style (though of course this part of the
3199 * proper SSH protocol _isn't_ subject to this kind of
3200 * DNS-domain-based extension), we define the new name in our
3203 static const char protoname[] =
3204 "SSHCONNECTION@putty.projects.tartarus.org-";
3206 struct do_ssh_connection_init_state {
3214 crState(do_ssh_connection_init_state);
3218 /* Search for a line beginning with the protocol name prefix in
3221 for (s->i = 0; protoname[s->i]; s->i++) {
3222 if ((char)c != protoname[s->i]) goto no;
3232 s->vstrsize = sizeof(protoname) + 16;
3233 s->vstring = snewn(s->vstrsize, char);
3234 strcpy(s->vstring, protoname);
3235 s->vslen = strlen(protoname);
3238 if (s->vslen >= s->vstrsize - 1) {
3240 s->vstring = sresize(s->vstring, s->vstrsize, char);
3242 s->vstring[s->vslen++] = c;
3245 s->version[s->i] = '\0';
3247 } else if (s->i < sizeof(s->version) - 1)
3248 s->version[s->i++] = c;
3249 } else if (c == '\012')
3251 crReturn(1); /* get another char */
3254 ssh->agentfwd_enabled = FALSE;
3255 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3257 s->vstring[s->vslen] = 0;
3258 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3259 logeventf(ssh, "Server version: %s", s->vstring);
3260 ssh_detect_bugs(ssh, s->vstring);
3263 * Decide which SSH protocol version to support. This is easy in
3264 * bare ssh-connection mode: only 2.0 is legal.
3266 if (ssh_versioncmp(s->version, "2.0") < 0) {
3267 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3270 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3271 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3277 logeventf(ssh, "Using bare ssh-connection protocol");
3279 /* Send the version string, if we haven't already */
3280 ssh_send_verstring(ssh, protoname, s->version);
3283 * Initialise bare connection protocol.
3285 ssh->protocol = ssh2_bare_connection_protocol;
3286 ssh2_bare_connection_protocol_setup(ssh);
3287 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3289 update_specials_menu(ssh->frontend);
3290 ssh->state = SSH_STATE_BEFORE_SIZE;
3291 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3294 * Get authconn (really just conn) under way.
3296 do_ssh2_authconn(ssh, NULL, 0, NULL);
3303 static void ssh_process_incoming_data(Ssh ssh,
3304 const unsigned char **data, int *datalen)
3306 struct Packet *pktin;
3308 pktin = ssh->s_rdpkt(ssh, data, datalen);
3310 ssh->protocol(ssh, NULL, 0, pktin);
3311 ssh_free_packet(pktin);
3315 static void ssh_queue_incoming_data(Ssh ssh,
3316 const unsigned char **data, int *datalen)
3318 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3323 static void ssh_process_queued_incoming_data(Ssh ssh)
3326 const unsigned char *data;
3329 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3330 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3334 while (!ssh->frozen && len > 0)
3335 ssh_process_incoming_data(ssh, &data, &len);
3338 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3342 static void ssh_set_frozen(Ssh ssh, int frozen)
3345 sk_set_frozen(ssh->s, frozen);
3346 ssh->frozen = frozen;
3349 static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen)
3351 /* Log raw data, if we're in that mode. */
3353 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3354 0, NULL, NULL, 0, NULL);
3356 crBegin(ssh->ssh_gotdata_crstate);
3359 * To begin with, feed the characters one by one to the
3360 * protocol initialisation / selection function do_ssh_init().
3361 * When that returns 0, we're done with the initial greeting
3362 * exchange and can move on to packet discipline.
3365 int ret; /* need not be kept across crReturn */
3367 crReturnV; /* more data please */
3368 ret = ssh->do_ssh_init(ssh, *data);
3376 * We emerge from that loop when the initial negotiation is
3377 * over and we have selected an s_rdpkt function. Now pass
3378 * everything to s_rdpkt, and then pass the resulting packets
3379 * to the proper protocol handler.
3383 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3385 ssh_queue_incoming_data(ssh, &data, &datalen);
3386 /* This uses up all data and cannot cause anything interesting
3387 * to happen; indeed, for anything to happen at all, we must
3388 * return, so break out. */
3390 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3391 /* This uses up some or all data, and may freeze the
3393 ssh_process_queued_incoming_data(ssh);
3395 /* This uses up some or all data, and may freeze the
3397 ssh_process_incoming_data(ssh, &data, &datalen);
3399 /* FIXME this is probably EBW. */
3400 if (ssh->state == SSH_STATE_CLOSED)
3403 /* We're out of data. Go and get some more. */
3409 static int ssh_do_close(Ssh ssh, int notify_exit)
3412 struct ssh_channel *c;
3414 ssh->state = SSH_STATE_CLOSED;
3415 expire_timer_context(ssh);
3420 notify_remote_exit(ssh->frontend);
3425 * Now we must shut down any port- and X-forwarded channels going
3426 * through this connection.
3428 if (ssh->channels) {
3429 while (NULL != (c = index234(ssh->channels, 0))) {
3432 x11_close(c->u.x11.xconn);
3435 case CHAN_SOCKDATA_DORMANT:
3436 pfd_close(c->u.pfd.pf);
3439 del234(ssh->channels, c); /* moving next one to index 0 */
3440 if (ssh->version == 2)
3441 bufchain_clear(&c->v.v2.outbuffer);
3446 * Go through port-forwardings, and close any associated
3447 * listening sockets.
3449 if (ssh->portfwds) {
3450 struct ssh_portfwd *pf;
3451 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3452 /* Dispose of any listening socket. */
3454 pfl_terminate(pf->local);
3455 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3458 freetree234(ssh->portfwds);
3459 ssh->portfwds = NULL;
3463 * Also stop attempting to connection-share.
3465 if (ssh->connshare) {
3466 sharestate_free(ssh->connshare);
3467 ssh->connshare = NULL;
3473 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3474 const char *error_msg, int error_code)
3476 Ssh ssh = (Ssh) plug;
3479 * While we're attempting connection sharing, don't loudly log
3480 * everything that happens. Real TCP connections need to be logged
3481 * when we _start_ trying to connect, because it might be ages
3482 * before they respond if something goes wrong; but connection
3483 * sharing is local and quick to respond, and it's sufficient to
3484 * simply wait and see whether it worked afterwards.
3487 if (!ssh->attempting_connshare)
3488 backend_socket_log(ssh->frontend, type, addr, port,
3489 error_msg, error_code, ssh->conf,
3490 ssh->session_started);
3493 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3494 const char *ds_err, const char *us_err)
3496 if (event == SHARE_NONE) {
3497 /* In this case, 'logtext' is an error message indicating a
3498 * reason why connection sharing couldn't be set up _at all_.
3499 * Failing that, ds_err and us_err indicate why we couldn't be
3500 * a downstream and an upstream respectively. */
3502 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3505 logeventf(ssh, "Could not set up connection sharing"
3506 " as downstream: %s", ds_err);
3508 logeventf(ssh, "Could not set up connection sharing"
3509 " as upstream: %s", us_err);
3511 } else if (event == SHARE_DOWNSTREAM) {
3512 /* In this case, 'logtext' is a local endpoint address */
3513 logeventf(ssh, "Using existing shared connection at %s", logtext);
3514 /* Also we should mention this in the console window to avoid
3515 * confusing users as to why this window doesn't behave the
3517 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3518 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3520 } else if (event == SHARE_UPSTREAM) {
3521 /* In this case, 'logtext' is a local endpoint address too */
3522 logeventf(ssh, "Sharing this connection at %s", logtext);
3526 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3529 Ssh ssh = (Ssh) plug;
3530 int need_notify = ssh_do_close(ssh, FALSE);
3533 if (!ssh->close_expected)
3534 error_msg = "Server unexpectedly closed network connection";
3536 error_msg = "Server closed network connection";
3539 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3543 notify_remote_exit(ssh->frontend);
3546 logevent(error_msg);
3547 if (!ssh->close_expected || !ssh->clean_exit)
3548 connection_fatal(ssh->frontend, "%s", error_msg);
3552 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3554 Ssh ssh = (Ssh) plug;
3555 ssh_gotdata(ssh, (unsigned char *)data, len);
3556 if (ssh->state == SSH_STATE_CLOSED) {
3557 ssh_do_close(ssh, TRUE);
3563 static void ssh_sent(Plug plug, int bufsize)
3565 Ssh ssh = (Ssh) plug;
3567 * If the send backlog on the SSH socket itself clears, we
3568 * should unthrottle the whole world if it was throttled.
3570 if (bufsize < SSH_MAX_BACKLOG)
3571 ssh_throttle_all(ssh, 0, bufsize);
3574 static void ssh_hostport_setup(const char *host, int port, Conf *conf,
3575 char **savedhost, int *savedport,
3578 char *loghost = conf_get_str(conf, CONF_loghost);
3580 *loghost_ret = loghost;
3586 tmphost = dupstr(loghost);
3587 *savedport = 22; /* default ssh port */
3590 * A colon suffix on the hostname string also lets us affect
3591 * savedport. (Unless there are multiple colons, in which case
3592 * we assume this is an unbracketed IPv6 literal.)
3594 colon = host_strrchr(tmphost, ':');
3595 if (colon && colon == host_strchr(tmphost, ':')) {
3598 *savedport = atoi(colon);
3601 *savedhost = host_strduptrim(tmphost);
3604 *savedhost = host_strduptrim(host);
3606 port = 22; /* default ssh port */
3611 static int ssh_test_for_upstream(const char *host, int port, Conf *conf)
3617 random_ref(); /* platform may need this to determine share socket name */
3618 ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL);
3619 ret = ssh_share_test_for_upstream(savedhost, savedport, conf);
3627 * Connect to specified host and port.
3628 * Returns an error message, or NULL on success.
3629 * Also places the canonical host name into `realhost'. It must be
3630 * freed by the caller.
3632 static const char *connect_to_host(Ssh ssh, const char *host, int port,
3633 char **realhost, int nodelay, int keepalive)
3635 static const struct plug_function_table fn_table = {
3646 int addressfamily, sshprot;
3648 ssh_hostport_setup(host, port, ssh->conf,
3649 &ssh->savedhost, &ssh->savedport, &loghost);
3651 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3654 * Try connection-sharing, in case that means we don't open a
3655 * socket after all. ssh_connection_sharing_init will connect to a
3656 * previously established upstream if it can, and failing that,
3657 * establish a listening socket for _us_ to be the upstream. In
3658 * the latter case it will return NULL just as if it had done
3659 * nothing, because here we only need to care if we're a
3660 * downstream and need to do our connection setup differently.
3662 ssh->connshare = NULL;
3663 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3664 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3665 ssh->conf, ssh, &ssh->connshare);
3666 ssh->attempting_connshare = FALSE;
3667 if (ssh->s != NULL) {
3669 * We are a downstream.
3671 ssh->bare_connection = TRUE;
3672 ssh->do_ssh_init = do_ssh_connection_init;
3673 ssh->fullhostname = NULL;
3674 *realhost = dupstr(host); /* best we can do */
3677 * We're not a downstream, so open a normal socket.
3679 ssh->do_ssh_init = do_ssh_init;
3684 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3685 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily,
3686 ssh->frontend, "SSH connection");
3687 if ((err = sk_addr_error(addr)) != NULL) {
3691 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3693 ssh->s = new_connection(addr, *realhost, port,
3694 0, 1, nodelay, keepalive,
3695 (Plug) ssh, ssh->conf);
3696 if ((err = sk_socket_error(ssh->s)) != NULL) {
3698 notify_remote_exit(ssh->frontend);
3704 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3705 * send the version string too.
3707 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3710 if (sshprot == 3 && !ssh->bare_connection) {
3712 ssh_send_verstring(ssh, "SSH-", NULL);
3716 * loghost, if configured, overrides realhost.
3720 *realhost = dupstr(loghost);
3727 * Throttle or unthrottle the SSH connection.
3729 static void ssh_throttle_conn(Ssh ssh, int adjust)
3731 int old_count = ssh->conn_throttle_count;
3732 ssh->conn_throttle_count += adjust;
3733 assert(ssh->conn_throttle_count >= 0);
3734 if (ssh->conn_throttle_count && !old_count) {
3735 ssh_set_frozen(ssh, 1);
3736 } else if (!ssh->conn_throttle_count && old_count) {
3737 ssh_set_frozen(ssh, 0);
3742 * Throttle or unthrottle _all_ local data streams (for when sends
3743 * on the SSH connection itself back up).
3745 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3748 struct ssh_channel *c;
3750 if (enable == ssh->throttled_all)
3752 ssh->throttled_all = enable;
3753 ssh->overall_bufsize = bufsize;
3756 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3758 case CHAN_MAINSESSION:
3760 * This is treated separately, outside the switch.
3764 x11_override_throttle(c->u.x11.xconn, enable);
3767 /* Agent channels require no buffer management. */
3770 pfd_override_throttle(c->u.pfd.pf, enable);
3776 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3778 Ssh ssh = (Ssh) sshv;
3780 ssh->agent_response = reply;
3781 ssh->agent_response_len = replylen;
3783 if (ssh->version == 1)
3784 do_ssh1_login(ssh, NULL, -1, NULL);
3786 do_ssh2_authconn(ssh, NULL, -1, NULL);
3789 static void ssh_dialog_callback(void *sshv, int ret)
3791 Ssh ssh = (Ssh) sshv;
3793 ssh->user_response = ret;
3795 if (ssh->version == 1)
3796 do_ssh1_login(ssh, NULL, -1, NULL);
3798 do_ssh2_transport(ssh, NULL, -1, NULL);
3801 * This may have unfrozen the SSH connection, so do a
3804 ssh_process_queued_incoming_data(ssh);
3807 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3809 struct ssh_channel *c = (struct ssh_channel *)cv;
3811 const void *sentreply = reply;
3813 c->u.a.outstanding_requests--;
3815 /* Fake SSH_AGENT_FAILURE. */
3816 sentreply = "\0\0\0\1\5";
3819 if (ssh->version == 2) {
3820 ssh2_add_channel_data(c, sentreply, replylen);
3823 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3824 PKT_INT, c->remoteid,
3826 PKT_DATA, sentreply, replylen,
3832 * If we've already seen an incoming EOF but haven't sent an
3833 * outgoing one, this may be the moment to send it.
3835 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3836 sshfwd_write_eof(c);
3840 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3841 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3842 * => log `wire_reason'.
3844 static void ssh_disconnect(Ssh ssh, const char *client_reason,
3845 const char *wire_reason,
3846 int code, int clean_exit)
3850 client_reason = wire_reason;
3852 error = dupprintf("Disconnected: %s", client_reason);
3854 error = dupstr("Disconnected");
3856 if (ssh->version == 1) {
3857 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3859 } else if (ssh->version == 2) {
3860 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3861 ssh2_pkt_adduint32(pktout, code);
3862 ssh2_pkt_addstring(pktout, wire_reason);
3863 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3864 ssh2_pkt_send_noqueue(ssh, pktout);
3867 ssh->close_expected = TRUE;
3868 ssh->clean_exit = clean_exit;
3869 ssh_closing((Plug)ssh, error, 0, 0);
3873 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3874 const struct ssh_signkey *ssh2keytype,
3877 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3878 return -1; /* no manual keys configured */
3883 * The fingerprint string we've been given will have things
3884 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3885 * narrow down to just the colon-separated hex block at the
3886 * end of the string.
3888 const char *p = strrchr(fingerprint, ' ');
3889 fingerprint = p ? p+1 : fingerprint;
3890 /* Quick sanity checks, including making sure it's in lowercase */
3891 assert(strlen(fingerprint) == 16*3 - 1);
3892 assert(fingerprint[2] == ':');
3893 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3895 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3897 return 1; /* success */
3902 * Construct the base64-encoded public key blob and see if
3905 unsigned char *binblob;
3907 int binlen, atoms, i;
3908 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3909 atoms = (binlen + 2) / 3;
3910 base64blob = snewn(atoms * 4 + 1, char);
3911 for (i = 0; i < atoms; i++)
3912 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3913 base64blob[atoms * 4] = '\0';
3915 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3918 return 1; /* success */
3927 * Handle the key exchange and user authentication phases.
3929 static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen,
3930 struct Packet *pktin)
3933 unsigned char cookie[8], *ptr;
3934 struct MD5Context md5c;
3935 struct do_ssh1_login_state {
3938 unsigned char *rsabuf;
3939 const unsigned char *keystr1, *keystr2;
3940 unsigned long supported_ciphers_mask, supported_auths_mask;
3941 int tried_publickey, tried_agent;
3942 int tis_auth_refused, ccard_auth_refused;
3943 unsigned char session_id[16];
3945 void *publickey_blob;
3946 int publickey_bloblen;
3947 char *publickey_comment;
3948 int privatekey_available, privatekey_encrypted;
3949 prompts_t *cur_prompt;
3952 unsigned char request[5], *response, *p;
3962 struct RSAKey servkey, hostkey;
3964 crState(do_ssh1_login_state);
3971 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3972 bombout(("Public key packet not received"));
3976 logevent("Received public keys");
3978 ptr = ssh_pkt_getdata(pktin, 8);
3980 bombout(("SSH-1 public key packet stopped before random cookie"));
3983 memcpy(cookie, ptr, 8);
3985 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3986 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3987 bombout(("Failed to read SSH-1 public keys from public key packet"));
3992 * Log the host key fingerprint.
3996 logevent("Host key fingerprint is:");
3997 strcpy(logmsg, " ");
3998 s->hostkey.comment = NULL;
3999 rsa_fingerprint(logmsg + strlen(logmsg),
4000 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
4004 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
4005 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
4006 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
4007 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
4008 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
4010 ssh->v1_local_protoflags =
4011 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
4012 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
4015 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
4016 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
4017 MD5Update(&md5c, cookie, 8);
4018 MD5Final(s->session_id, &md5c);
4020 for (i = 0; i < 32; i++)
4021 ssh->session_key[i] = random_byte();
4024 * Verify that the `bits' and `bytes' parameters match.
4026 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
4027 s->servkey.bits > s->servkey.bytes * 8) {
4028 bombout(("SSH-1 public keys were badly formatted"));
4032 s->len = (s->hostkey.bytes > s->servkey.bytes ?
4033 s->hostkey.bytes : s->servkey.bytes);
4035 s->rsabuf = snewn(s->len, unsigned char);
4038 * Verify the host key.
4042 * First format the key into a string.
4044 int len = rsastr_len(&s->hostkey);
4045 char fingerprint[100];
4046 char *keystr = snewn(len, char);
4047 rsastr_fmt(keystr, &s->hostkey);
4048 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
4050 /* First check against manually configured host keys. */
4051 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
4052 if (s->dlgret == 0) { /* did not match */
4053 bombout(("Host key did not appear in manually configured list"));
4056 } else if (s->dlgret < 0) { /* none configured; use standard handling */
4057 ssh_set_frozen(ssh, 1);
4058 s->dlgret = verify_ssh_host_key(ssh->frontend,
4059 ssh->savedhost, ssh->savedport,
4060 "rsa", keystr, fingerprint,
4061 ssh_dialog_callback, ssh);
4066 if (s->dlgret < 0) {
4070 bombout(("Unexpected data from server while waiting"
4071 " for user host key response"));
4074 } while (pktin || inlen > 0);
4075 s->dlgret = ssh->user_response;
4077 ssh_set_frozen(ssh, 0);
4079 if (s->dlgret == 0) {
4080 ssh_disconnect(ssh, "User aborted at host key verification",
4089 for (i = 0; i < 32; i++) {
4090 s->rsabuf[i] = ssh->session_key[i];
4092 s->rsabuf[i] ^= s->session_id[i];
4095 if (s->hostkey.bytes > s->servkey.bytes) {
4096 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
4098 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
4100 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
4102 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
4105 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
4109 logevent("Encrypted session key");
4112 int cipher_chosen = 0, warn = 0;
4113 const char *cipher_string = NULL;
4115 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4116 int next_cipher = conf_get_int_int(ssh->conf,
4117 CONF_ssh_cipherlist, i);
4118 if (next_cipher == CIPHER_WARN) {
4119 /* If/when we choose a cipher, warn about it */
4121 } else if (next_cipher == CIPHER_AES) {
4122 /* XXX Probably don't need to mention this. */
4123 logevent("AES not supported in SSH-1, skipping");
4125 switch (next_cipher) {
4126 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
4127 cipher_string = "3DES"; break;
4128 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
4129 cipher_string = "Blowfish"; break;
4130 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
4131 cipher_string = "single-DES"; break;
4133 if (s->supported_ciphers_mask & (1 << s->cipher_type))
4137 if (!cipher_chosen) {
4138 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
4139 bombout(("Server violates SSH-1 protocol by not "
4140 "supporting 3DES encryption"));
4142 /* shouldn't happen */
4143 bombout(("No supported ciphers found"));
4147 /* Warn about chosen cipher if necessary. */
4149 ssh_set_frozen(ssh, 1);
4150 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
4151 ssh_dialog_callback, ssh);
4152 if (s->dlgret < 0) {
4156 bombout(("Unexpected data from server while waiting"
4157 " for user response"));
4160 } while (pktin || inlen > 0);
4161 s->dlgret = ssh->user_response;
4163 ssh_set_frozen(ssh, 0);
4164 if (s->dlgret == 0) {
4165 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
4172 switch (s->cipher_type) {
4173 case SSH_CIPHER_3DES:
4174 logevent("Using 3DES encryption");
4176 case SSH_CIPHER_DES:
4177 logevent("Using single-DES encryption");
4179 case SSH_CIPHER_BLOWFISH:
4180 logevent("Using Blowfish encryption");
4184 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4185 PKT_CHAR, s->cipher_type,
4186 PKT_DATA, cookie, 8,
4187 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4188 PKT_DATA, s->rsabuf, s->len,
4189 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4191 logevent("Trying to enable encryption...");
4195 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4196 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4198 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4199 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4200 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4202 ssh->crcda_ctx = crcda_make_context();
4203 logevent("Installing CRC compensation attack detector");
4205 if (s->servkey.modulus) {
4206 sfree(s->servkey.modulus);
4207 s->servkey.modulus = NULL;
4209 if (s->servkey.exponent) {
4210 sfree(s->servkey.exponent);
4211 s->servkey.exponent = NULL;
4213 if (s->hostkey.modulus) {
4214 sfree(s->hostkey.modulus);
4215 s->hostkey.modulus = NULL;
4217 if (s->hostkey.exponent) {
4218 sfree(s->hostkey.exponent);
4219 s->hostkey.exponent = NULL;
4223 if (pktin->type != SSH1_SMSG_SUCCESS) {
4224 bombout(("Encryption not successfully enabled"));
4228 logevent("Successfully started encryption");
4230 fflush(stdout); /* FIXME eh? */
4232 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4233 int ret; /* need not be kept over crReturn */
4234 s->cur_prompt = new_prompts(ssh->frontend);
4235 s->cur_prompt->to_server = TRUE;
4236 s->cur_prompt->name = dupstr("SSH login name");
4237 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4238 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4241 crWaitUntil(!pktin);
4242 ret = get_userpass_input(s->cur_prompt, in, inlen);
4247 * Failed to get a username. Terminate.
4249 free_prompts(s->cur_prompt);
4250 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4253 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4254 free_prompts(s->cur_prompt);
4257 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4259 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4261 if (flags & FLAG_INTERACTIVE &&
4262 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4263 c_write_str(ssh, userlog);
4264 c_write_str(ssh, "\r\n");
4272 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4273 /* We must not attempt PK auth. Pretend we've already tried it. */
4274 s->tried_publickey = s->tried_agent = 1;
4276 s->tried_publickey = s->tried_agent = 0;
4278 s->tis_auth_refused = s->ccard_auth_refused = 0;
4280 * Load the public half of any configured keyfile for later use.
4282 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4283 if (!filename_is_null(s->keyfile)) {
4285 logeventf(ssh, "Reading key file \"%.150s\"",
4286 filename_to_str(s->keyfile));
4287 keytype = key_type(s->keyfile);
4288 if (keytype == SSH_KEYTYPE_SSH1 ||
4289 keytype == SSH_KEYTYPE_SSH1_PUBLIC) {
4291 if (rsakey_pubblob(s->keyfile,
4292 &s->publickey_blob, &s->publickey_bloblen,
4293 &s->publickey_comment, &error)) {
4294 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1);
4295 if (!s->privatekey_available)
4296 logeventf(ssh, "Key file contains public key only");
4297 s->privatekey_encrypted = rsakey_encrypted(s->keyfile,
4301 logeventf(ssh, "Unable to load key (%s)", error);
4302 msgbuf = dupprintf("Unable to load key file "
4303 "\"%.150s\" (%s)\r\n",
4304 filename_to_str(s->keyfile),
4306 c_write_str(ssh, msgbuf);
4308 s->publickey_blob = NULL;
4312 logeventf(ssh, "Unable to use this key file (%s)",
4313 key_type_to_str(keytype));
4314 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4316 filename_to_str(s->keyfile),
4317 key_type_to_str(keytype));
4318 c_write_str(ssh, msgbuf);
4320 s->publickey_blob = NULL;
4323 s->publickey_blob = NULL;
4325 while (pktin->type == SSH1_SMSG_FAILURE) {
4326 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4328 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4330 * Attempt RSA authentication using Pageant.
4336 logevent("Pageant is running. Requesting keys.");
4338 /* Request the keys held by the agent. */
4339 PUT_32BIT(s->request, 1);
4340 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4341 if (!agent_query(s->request, 5, &r, &s->responselen,
4342 ssh_agent_callback, ssh)) {
4346 bombout(("Unexpected data from server while waiting"
4347 " for agent response"));
4350 } while (pktin || inlen > 0);
4351 r = ssh->agent_response;
4352 s->responselen = ssh->agent_response_len;
4354 s->response = (unsigned char *) r;
4355 if (s->response && s->responselen >= 5 &&
4356 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4357 s->p = s->response + 5;
4358 s->nkeys = toint(GET_32BIT(s->p));
4360 logeventf(ssh, "Pageant reported negative key count %d",
4365 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4366 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4367 unsigned char *pkblob = s->p;
4371 do { /* do while (0) to make breaking easy */
4372 n = ssh1_read_bignum
4373 (s->p, toint(s->responselen-(s->p-s->response)),
4378 n = ssh1_read_bignum
4379 (s->p, toint(s->responselen-(s->p-s->response)),
4384 if (s->responselen - (s->p-s->response) < 4)
4386 s->commentlen = toint(GET_32BIT(s->p));
4388 if (s->commentlen < 0 ||
4389 toint(s->responselen - (s->p-s->response)) <
4392 s->commentp = (char *)s->p;
4393 s->p += s->commentlen;
4397 logevent("Pageant key list packet was truncated");
4401 if (s->publickey_blob) {
4402 if (!memcmp(pkblob, s->publickey_blob,
4403 s->publickey_bloblen)) {
4404 logeventf(ssh, "Pageant key #%d matches "
4405 "configured key file", s->keyi);
4406 s->tried_publickey = 1;
4408 /* Skip non-configured key */
4411 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4412 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4413 PKT_BIGNUM, s->key.modulus, PKT_END);
4415 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4416 logevent("Key refused");
4419 logevent("Received RSA challenge");
4420 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4421 bombout(("Server's RSA challenge was badly formatted"));
4426 char *agentreq, *q, *ret;
4429 len = 1 + 4; /* message type, bit count */
4430 len += ssh1_bignum_length(s->key.exponent);
4431 len += ssh1_bignum_length(s->key.modulus);
4432 len += ssh1_bignum_length(s->challenge);
4433 len += 16; /* session id */
4434 len += 4; /* response format */
4435 agentreq = snewn(4 + len, char);
4436 PUT_32BIT(agentreq, len);
4438 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4439 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4441 q += ssh1_write_bignum(q, s->key.exponent);
4442 q += ssh1_write_bignum(q, s->key.modulus);
4443 q += ssh1_write_bignum(q, s->challenge);
4444 memcpy(q, s->session_id, 16);
4446 PUT_32BIT(q, 1); /* response format */
4447 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4448 ssh_agent_callback, ssh)) {
4453 bombout(("Unexpected data from server"
4454 " while waiting for agent"
4458 } while (pktin || inlen > 0);
4459 vret = ssh->agent_response;
4460 retlen = ssh->agent_response_len;
4465 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4466 logevent("Sending Pageant's response");
4467 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4468 PKT_DATA, ret + 5, 16,
4472 if (pktin->type == SSH1_SMSG_SUCCESS) {
4474 ("Pageant's response accepted");
4475 if (flags & FLAG_VERBOSE) {
4476 c_write_str(ssh, "Authenticated using"
4478 c_write(ssh, s->commentp,
4480 c_write_str(ssh, "\" from agent\r\n");
4485 ("Pageant's response not accepted");
4488 ("Pageant failed to answer challenge");
4492 logevent("No reply received from Pageant");
4495 freebn(s->key.exponent);
4496 freebn(s->key.modulus);
4497 freebn(s->challenge);
4502 if (s->publickey_blob && !s->tried_publickey)
4503 logevent("Configured key file not in Pageant");
4505 logevent("Failed to get reply from Pageant");
4510 if (s->publickey_blob && s->privatekey_available &&
4511 !s->tried_publickey) {
4513 * Try public key authentication with the specified
4516 int got_passphrase; /* need not be kept over crReturn */
4517 if (flags & FLAG_VERBOSE)
4518 c_write_str(ssh, "Trying public key authentication.\r\n");
4519 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4520 logeventf(ssh, "Trying public key \"%s\"",
4521 filename_to_str(s->keyfile));
4522 s->tried_publickey = 1;
4523 got_passphrase = FALSE;
4524 while (!got_passphrase) {
4526 * Get a passphrase, if necessary.
4528 char *passphrase = NULL; /* only written after crReturn */
4530 if (!s->privatekey_encrypted) {
4531 if (flags & FLAG_VERBOSE)
4532 c_write_str(ssh, "No passphrase required.\r\n");
4535 int ret; /* need not be kept over crReturn */
4536 s->cur_prompt = new_prompts(ssh->frontend);
4537 s->cur_prompt->to_server = FALSE;
4538 s->cur_prompt->name = dupstr("SSH key passphrase");
4539 add_prompt(s->cur_prompt,
4540 dupprintf("Passphrase for key \"%.100s\": ",
4541 s->publickey_comment), FALSE);
4542 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4545 crWaitUntil(!pktin);
4546 ret = get_userpass_input(s->cur_prompt, in, inlen);
4550 /* Failed to get a passphrase. Terminate. */
4551 free_prompts(s->cur_prompt);
4552 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4556 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4557 free_prompts(s->cur_prompt);
4560 * Try decrypting key with passphrase.
4562 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4563 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4566 smemclr(passphrase, strlen(passphrase));
4570 /* Correct passphrase. */
4571 got_passphrase = TRUE;
4572 } else if (ret == 0) {
4573 c_write_str(ssh, "Couldn't load private key from ");
4574 c_write_str(ssh, filename_to_str(s->keyfile));
4575 c_write_str(ssh, " (");
4576 c_write_str(ssh, error);
4577 c_write_str(ssh, ").\r\n");
4578 got_passphrase = FALSE;
4579 break; /* go and try something else */
4580 } else if (ret == -1) {
4581 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4582 got_passphrase = FALSE;
4585 assert(0 && "unexpected return from loadrsakey()");
4586 got_passphrase = FALSE; /* placate optimisers */
4590 if (got_passphrase) {
4593 * Send a public key attempt.
4595 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4596 PKT_BIGNUM, s->key.modulus, PKT_END);
4599 if (pktin->type == SSH1_SMSG_FAILURE) {
4600 c_write_str(ssh, "Server refused our public key.\r\n");
4601 continue; /* go and try something else */
4603 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4604 bombout(("Bizarre response to offer of public key"));
4610 unsigned char buffer[32];
4611 Bignum challenge, response;
4613 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4614 bombout(("Server's RSA challenge was badly formatted"));
4617 response = rsadecrypt(challenge, &s->key);
4618 freebn(s->key.private_exponent);/* burn the evidence */
4620 for (i = 0; i < 32; i++) {
4621 buffer[i] = bignum_byte(response, 31 - i);
4625 MD5Update(&md5c, buffer, 32);
4626 MD5Update(&md5c, s->session_id, 16);
4627 MD5Final(buffer, &md5c);
4629 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4630 PKT_DATA, buffer, 16, PKT_END);
4637 if (pktin->type == SSH1_SMSG_FAILURE) {
4638 if (flags & FLAG_VERBOSE)
4639 c_write_str(ssh, "Failed to authenticate with"
4640 " our public key.\r\n");
4641 continue; /* go and try something else */
4642 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4643 bombout(("Bizarre response to RSA authentication response"));
4647 break; /* we're through! */
4653 * Otherwise, try various forms of password-like authentication.
4655 s->cur_prompt = new_prompts(ssh->frontend);
4657 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4658 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4659 !s->tis_auth_refused) {
4660 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4661 logevent("Requested TIS authentication");
4662 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4664 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4665 logevent("TIS authentication declined");
4666 if (flags & FLAG_INTERACTIVE)
4667 c_write_str(ssh, "TIS authentication refused.\r\n");
4668 s->tis_auth_refused = 1;
4673 char *instr_suf, *prompt;
4675 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4677 bombout(("TIS challenge packet was badly formed"));
4680 logevent("Received TIS challenge");
4681 s->cur_prompt->to_server = TRUE;
4682 s->cur_prompt->name = dupstr("SSH TIS authentication");
4683 /* Prompt heuristic comes from OpenSSH */
4684 if (memchr(challenge, '\n', challengelen)) {
4685 instr_suf = dupstr("");
4686 prompt = dupprintf("%.*s", challengelen, challenge);
4688 instr_suf = dupprintf("%.*s", challengelen, challenge);
4689 prompt = dupstr("Response: ");
4691 s->cur_prompt->instruction =
4692 dupprintf("Using TIS authentication.%s%s",
4693 (*instr_suf) ? "\n" : "",
4695 s->cur_prompt->instr_reqd = TRUE;
4696 add_prompt(s->cur_prompt, prompt, FALSE);
4700 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4701 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4702 !s->ccard_auth_refused) {
4703 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4704 logevent("Requested CryptoCard authentication");
4705 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4707 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4708 logevent("CryptoCard authentication declined");
4709 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4710 s->ccard_auth_refused = 1;
4715 char *instr_suf, *prompt;
4717 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4719 bombout(("CryptoCard challenge packet was badly formed"));
4722 logevent("Received CryptoCard challenge");
4723 s->cur_prompt->to_server = TRUE;
4724 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4725 s->cur_prompt->name_reqd = FALSE;
4726 /* Prompt heuristic comes from OpenSSH */
4727 if (memchr(challenge, '\n', challengelen)) {
4728 instr_suf = dupstr("");
4729 prompt = dupprintf("%.*s", challengelen, challenge);
4731 instr_suf = dupprintf("%.*s", challengelen, challenge);
4732 prompt = dupstr("Response: ");
4734 s->cur_prompt->instruction =
4735 dupprintf("Using CryptoCard authentication.%s%s",
4736 (*instr_suf) ? "\n" : "",
4738 s->cur_prompt->instr_reqd = TRUE;
4739 add_prompt(s->cur_prompt, prompt, FALSE);
4743 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4744 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4745 bombout(("No supported authentication methods available"));
4748 s->cur_prompt->to_server = TRUE;
4749 s->cur_prompt->name = dupstr("SSH password");
4750 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4751 ssh->username, ssh->savedhost),
4756 * Show password prompt, having first obtained it via a TIS
4757 * or CryptoCard exchange if we're doing TIS or CryptoCard
4761 int ret; /* need not be kept over crReturn */
4762 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4765 crWaitUntil(!pktin);
4766 ret = get_userpass_input(s->cur_prompt, in, inlen);
4771 * Failed to get a password (for example
4772 * because one was supplied on the command line
4773 * which has already failed to work). Terminate.
4775 free_prompts(s->cur_prompt);
4776 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4781 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4783 * Defence against traffic analysis: we send a
4784 * whole bunch of packets containing strings of
4785 * different lengths. One of these strings is the
4786 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4787 * The others are all random data in
4788 * SSH1_MSG_IGNORE packets. This way a passive
4789 * listener can't tell which is the password, and
4790 * hence can't deduce the password length.
4792 * Anybody with a password length greater than 16
4793 * bytes is going to have enough entropy in their
4794 * password that a listener won't find it _that_
4795 * much help to know how long it is. So what we'll
4798 * - if password length < 16, we send 15 packets
4799 * containing string lengths 1 through 15
4801 * - otherwise, we let N be the nearest multiple
4802 * of 8 below the password length, and send 8
4803 * packets containing string lengths N through
4804 * N+7. This won't obscure the order of
4805 * magnitude of the password length, but it will
4806 * introduce a bit of extra uncertainty.
4808 * A few servers can't deal with SSH1_MSG_IGNORE, at
4809 * least in this context. For these servers, we need
4810 * an alternative defence. We make use of the fact
4811 * that the password is interpreted as a C string:
4812 * so we can append a NUL, then some random data.
4814 * A few servers can deal with neither SSH1_MSG_IGNORE
4815 * here _nor_ a padded password string.
4816 * For these servers we are left with no defences
4817 * against password length sniffing.
4819 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4820 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4822 * The server can deal with SSH1_MSG_IGNORE, so
4823 * we can use the primary defence.
4825 int bottom, top, pwlen, i;
4828 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4830 bottom = 0; /* zero length passwords are OK! :-) */
4833 bottom = pwlen & ~7;
4837 assert(pwlen >= bottom && pwlen <= top);
4839 randomstr = snewn(top + 1, char);
4841 for (i = bottom; i <= top; i++) {
4843 defer_packet(ssh, s->pwpkt_type,
4844 PKT_STR,s->cur_prompt->prompts[0]->result,
4847 for (j = 0; j < i; j++) {
4849 randomstr[j] = random_byte();
4850 } while (randomstr[j] == '\0');
4852 randomstr[i] = '\0';
4853 defer_packet(ssh, SSH1_MSG_IGNORE,
4854 PKT_STR, randomstr, PKT_END);
4857 logevent("Sending password with camouflage packets");
4858 ssh_pkt_defersend(ssh);
4861 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4863 * The server can't deal with SSH1_MSG_IGNORE
4864 * but can deal with padded passwords, so we
4865 * can use the secondary defence.
4871 len = strlen(s->cur_prompt->prompts[0]->result);
4872 if (len < sizeof(string)) {
4874 strcpy(string, s->cur_prompt->prompts[0]->result);
4875 len++; /* cover the zero byte */
4876 while (len < sizeof(string)) {
4877 string[len++] = (char) random_byte();
4880 ss = s->cur_prompt->prompts[0]->result;
4882 logevent("Sending length-padded password");
4883 send_packet(ssh, s->pwpkt_type,
4884 PKT_INT, len, PKT_DATA, ss, len,
4888 * The server is believed unable to cope with
4889 * any of our password camouflage methods.
4892 len = strlen(s->cur_prompt->prompts[0]->result);
4893 logevent("Sending unpadded password");
4894 send_packet(ssh, s->pwpkt_type,
4896 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4900 send_packet(ssh, s->pwpkt_type,
4901 PKT_STR, s->cur_prompt->prompts[0]->result,
4904 logevent("Sent password");
4905 free_prompts(s->cur_prompt);
4907 if (pktin->type == SSH1_SMSG_FAILURE) {
4908 if (flags & FLAG_VERBOSE)
4909 c_write_str(ssh, "Access denied\r\n");
4910 logevent("Authentication refused");
4911 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4912 bombout(("Strange packet received, type %d", pktin->type));
4918 if (s->publickey_blob) {
4919 sfree(s->publickey_blob);
4920 sfree(s->publickey_comment);
4923 logevent("Authentication successful");
4928 static void ssh_channel_try_eof(struct ssh_channel *c)
4931 assert(c->pending_eof); /* precondition for calling us */
4933 return; /* can't close: not even opened yet */
4934 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4935 return; /* can't send EOF: pending outgoing data */
4937 c->pending_eof = FALSE; /* we're about to send it */
4938 if (ssh->version == 1) {
4939 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4941 c->closes |= CLOSES_SENT_EOF;
4943 struct Packet *pktout;
4944 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4945 ssh2_pkt_adduint32(pktout, c->remoteid);
4946 ssh2_pkt_send(ssh, pktout);
4947 c->closes |= CLOSES_SENT_EOF;
4948 ssh2_channel_check_close(c);
4952 Conf *sshfwd_get_conf(struct ssh_channel *c)
4958 void sshfwd_write_eof(struct ssh_channel *c)
4962 if (ssh->state == SSH_STATE_CLOSED)
4965 if (c->closes & CLOSES_SENT_EOF)
4968 c->pending_eof = TRUE;
4969 ssh_channel_try_eof(c);
4972 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4976 if (ssh->state == SSH_STATE_CLOSED)
4981 x11_close(c->u.x11.xconn);
4982 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4986 case CHAN_SOCKDATA_DORMANT:
4987 pfd_close(c->u.pfd.pf);
4988 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4991 c->type = CHAN_ZOMBIE;
4992 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4994 ssh2_channel_check_close(c);
4997 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
5001 if (ssh->state == SSH_STATE_CLOSED)
5004 if (ssh->version == 1) {
5005 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
5006 PKT_INT, c->remoteid,
5007 PKT_INT, len, PKT_DATA, buf, len,
5010 * In SSH-1 we can return 0 here - implying that forwarded
5011 * connections are never individually throttled - because
5012 * the only circumstance that can cause throttling will be
5013 * the whole SSH connection backing up, in which case
5014 * _everything_ will be throttled as a whole.
5018 ssh2_add_channel_data(c, buf, len);
5019 return ssh2_try_send(c);
5023 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
5028 if (ssh->state == SSH_STATE_CLOSED)
5031 if (ssh->version == 1) {
5032 buflimit = SSH1_BUFFER_LIMIT;
5034 buflimit = c->v.v2.locmaxwin;
5035 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
5037 if (c->throttling_conn && bufsize <= buflimit) {
5038 c->throttling_conn = 0;
5039 ssh_throttle_conn(ssh, -1);
5043 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
5045 struct queued_handler *qh = ssh->qhead;
5049 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
5052 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
5053 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
5056 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
5057 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
5061 ssh->qhead = qh->next;
5063 if (ssh->qhead->msg1 > 0) {
5064 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5065 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
5067 if (ssh->qhead->msg2 > 0) {
5068 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5069 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
5072 ssh->qhead = ssh->qtail = NULL;
5075 qh->handler(ssh, pktin, qh->ctx);
5080 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
5081 chandler_fn_t handler, void *ctx)
5083 struct queued_handler *qh;
5085 qh = snew(struct queued_handler);
5088 qh->handler = handler;
5092 if (ssh->qtail == NULL) {
5096 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
5097 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
5100 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
5101 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
5104 ssh->qtail->next = qh;
5109 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
5111 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
5113 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
5114 SSH2_MSG_REQUEST_SUCCESS)) {
5115 logeventf(ssh, "Remote port forwarding from %s enabled",
5118 logeventf(ssh, "Remote port forwarding from %s refused",
5121 rpf = del234(ssh->rportfwds, pf);
5123 pf->pfrec->remote = NULL;
5128 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
5131 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
5134 pf->share_ctx = share_ctx;
5135 pf->shost = dupstr(shost);
5137 pf->sportdesc = NULL;
5138 if (!ssh->rportfwds) {
5139 assert(ssh->version == 2);
5140 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5142 if (add234(ssh->rportfwds, pf) != pf) {
5150 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
5153 share_got_pkt_from_server(ctx, pktin->type,
5154 pktin->body, pktin->length);
5157 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
5159 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
5160 ssh_sharing_global_request_response, share_ctx);
5163 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
5165 struct ssh_portfwd *epf;
5169 if (!ssh->portfwds) {
5170 ssh->portfwds = newtree234(ssh_portcmp);
5173 * Go through the existing port forwardings and tag them
5174 * with status==DESTROY. Any that we want to keep will be
5175 * re-enabled (status==KEEP) as we go through the
5176 * configuration and find out which bits are the same as
5179 struct ssh_portfwd *epf;
5181 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5182 epf->status = DESTROY;
5185 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
5187 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5188 char *kp, *kp2, *vp, *vp2;
5189 char address_family, type;
5190 int sport,dport,sserv,dserv;
5191 char *sports, *dports, *saddr, *host;
5195 address_family = 'A';
5197 if (*kp == 'A' || *kp == '4' || *kp == '6')
5198 address_family = *kp++;
5199 if (*kp == 'L' || *kp == 'R')
5202 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5204 * There's a colon in the middle of the source port
5205 * string, which means that the part before it is
5206 * actually a source address.
5208 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5209 saddr = host_strduptrim(saddr_tmp);
5216 sport = atoi(sports);
5220 sport = net_service_lookup(sports);
5222 logeventf(ssh, "Service lookup failed for source"
5223 " port \"%s\"", sports);
5227 if (type == 'L' && !strcmp(val, "D")) {
5228 /* dynamic forwarding */
5235 /* ordinary forwarding */
5237 vp2 = vp + host_strcspn(vp, ":");
5238 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5242 dport = atoi(dports);
5246 dport = net_service_lookup(dports);
5248 logeventf(ssh, "Service lookup failed for destination"
5249 " port \"%s\"", dports);
5254 if (sport && dport) {
5255 /* Set up a description of the source port. */
5256 struct ssh_portfwd *pfrec, *epfrec;
5258 pfrec = snew(struct ssh_portfwd);
5260 pfrec->saddr = saddr;
5261 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5262 pfrec->sport = sport;
5263 pfrec->daddr = host;
5264 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5265 pfrec->dport = dport;
5266 pfrec->local = NULL;
5267 pfrec->remote = NULL;
5268 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5269 address_family == '6' ? ADDRTYPE_IPV6 :
5272 epfrec = add234(ssh->portfwds, pfrec);
5273 if (epfrec != pfrec) {
5274 if (epfrec->status == DESTROY) {
5276 * We already have a port forwarding up and running
5277 * with precisely these parameters. Hence, no need
5278 * to do anything; simply re-tag the existing one
5281 epfrec->status = KEEP;
5284 * Anything else indicates that there was a duplicate
5285 * in our input, which we'll silently ignore.
5287 free_portfwd(pfrec);
5289 pfrec->status = CREATE;
5298 * Now go through and destroy any port forwardings which were
5301 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5302 if (epf->status == DESTROY) {
5305 message = dupprintf("%s port forwarding from %s%s%d",
5306 epf->type == 'L' ? "local" :
5307 epf->type == 'R' ? "remote" : "dynamic",
5308 epf->saddr ? epf->saddr : "",
5309 epf->saddr ? ":" : "",
5312 if (epf->type != 'D') {
5313 char *msg2 = dupprintf("%s to %s:%d", message,
5314 epf->daddr, epf->dport);
5319 logeventf(ssh, "Cancelling %s", message);
5322 /* epf->remote or epf->local may be NULL if setting up a
5323 * forwarding failed. */
5325 struct ssh_rportfwd *rpf = epf->remote;
5326 struct Packet *pktout;
5329 * Cancel the port forwarding at the server
5332 if (ssh->version == 1) {
5334 * We cannot cancel listening ports on the
5335 * server side in SSH-1! There's no message
5336 * to support it. Instead, we simply remove
5337 * the rportfwd record from the local end
5338 * so that any connections the server tries
5339 * to make on it are rejected.
5342 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5343 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5344 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5346 ssh2_pkt_addstring(pktout, epf->saddr);
5347 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5348 /* XXX: rport_acceptall may not represent
5349 * what was used to open the original connection,
5350 * since it's reconfigurable. */
5351 ssh2_pkt_addstring(pktout, "");
5353 ssh2_pkt_addstring(pktout, "localhost");
5355 ssh2_pkt_adduint32(pktout, epf->sport);
5356 ssh2_pkt_send(ssh, pktout);
5359 del234(ssh->rportfwds, rpf);
5361 } else if (epf->local) {
5362 pfl_terminate(epf->local);
5365 delpos234(ssh->portfwds, i);
5367 i--; /* so we don't skip one in the list */
5371 * And finally, set up any new port forwardings (status==CREATE).
5373 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5374 if (epf->status == CREATE) {
5375 char *sportdesc, *dportdesc;
5376 sportdesc = dupprintf("%s%s%s%s%d%s",
5377 epf->saddr ? epf->saddr : "",
5378 epf->saddr ? ":" : "",
5379 epf->sserv ? epf->sserv : "",
5380 epf->sserv ? "(" : "",
5382 epf->sserv ? ")" : "");
5383 if (epf->type == 'D') {
5386 dportdesc = dupprintf("%s:%s%s%d%s",
5388 epf->dserv ? epf->dserv : "",
5389 epf->dserv ? "(" : "",
5391 epf->dserv ? ")" : "");
5394 if (epf->type == 'L') {
5395 char *err = pfl_listen(epf->daddr, epf->dport,
5396 epf->saddr, epf->sport,
5397 ssh, conf, &epf->local,
5398 epf->addressfamily);
5400 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5401 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5402 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5403 sportdesc, dportdesc,
5404 err ? " failed: " : "", err ? err : "");
5407 } else if (epf->type == 'D') {
5408 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5409 ssh, conf, &epf->local,
5410 epf->addressfamily);
5412 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5413 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5414 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5416 err ? " failed: " : "", err ? err : "");
5421 struct ssh_rportfwd *pf;
5424 * Ensure the remote port forwardings tree exists.
5426 if (!ssh->rportfwds) {
5427 if (ssh->version == 1)
5428 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5430 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5433 pf = snew(struct ssh_rportfwd);
5434 pf->share_ctx = NULL;
5435 pf->dhost = dupstr(epf->daddr);
5436 pf->dport = epf->dport;
5438 pf->shost = dupstr(epf->saddr);
5439 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5440 pf->shost = dupstr("");
5442 pf->shost = dupstr("localhost");
5444 pf->sport = epf->sport;
5445 if (add234(ssh->rportfwds, pf) != pf) {
5446 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5447 epf->daddr, epf->dport);
5450 logeventf(ssh, "Requesting remote port %s"
5451 " forward to %s", sportdesc, dportdesc);
5453 pf->sportdesc = sportdesc;
5458 if (ssh->version == 1) {
5459 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5460 PKT_INT, epf->sport,
5461 PKT_STR, epf->daddr,
5462 PKT_INT, epf->dport,
5464 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5466 ssh_rportfwd_succfail, pf);
5468 struct Packet *pktout;
5469 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5470 ssh2_pkt_addstring(pktout, "tcpip-forward");
5471 ssh2_pkt_addbool(pktout, 1);/* want reply */
5472 ssh2_pkt_addstring(pktout, pf->shost);
5473 ssh2_pkt_adduint32(pktout, pf->sport);
5474 ssh2_pkt_send(ssh, pktout);
5476 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5477 SSH2_MSG_REQUEST_FAILURE,
5478 ssh_rportfwd_succfail, pf);
5487 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5490 int stringlen, bufsize;
5492 ssh_pkt_getstring(pktin, &string, &stringlen);
5493 if (string == NULL) {
5494 bombout(("Incoming terminal data packet was badly formed"));
5498 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5500 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5501 ssh->v1_stdout_throttling = 1;
5502 ssh_throttle_conn(ssh, +1);
5506 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5508 /* Remote side is trying to open a channel to talk to our
5509 * X-Server. Give them back a local channel number. */
5510 struct ssh_channel *c;
5511 int remoteid = ssh_pkt_getuint32(pktin);
5513 logevent("Received X11 connect request");
5514 /* Refuse if X11 forwarding is disabled. */
5515 if (!ssh->X11_fwd_enabled) {
5516 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5517 PKT_INT, remoteid, PKT_END);
5518 logevent("Rejected X11 connect request");
5520 c = snew(struct ssh_channel);
5523 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5524 c->remoteid = remoteid;
5525 c->halfopen = FALSE;
5526 c->localid = alloc_channel_id(ssh);
5528 c->pending_eof = FALSE;
5529 c->throttling_conn = 0;
5530 c->type = CHAN_X11; /* identify channel type */
5531 add234(ssh->channels, c);
5532 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5533 PKT_INT, c->remoteid, PKT_INT,
5534 c->localid, PKT_END);
5535 logevent("Opened X11 forward channel");
5539 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5541 /* Remote side is trying to open a channel to talk to our
5542 * agent. Give them back a local channel number. */
5543 struct ssh_channel *c;
5544 int remoteid = ssh_pkt_getuint32(pktin);
5546 /* Refuse if agent forwarding is disabled. */
5547 if (!ssh->agentfwd_enabled) {
5548 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5549 PKT_INT, remoteid, PKT_END);
5551 c = snew(struct ssh_channel);
5553 c->remoteid = remoteid;
5554 c->halfopen = FALSE;
5555 c->localid = alloc_channel_id(ssh);
5557 c->pending_eof = FALSE;
5558 c->throttling_conn = 0;
5559 c->type = CHAN_AGENT; /* identify channel type */
5560 c->u.a.lensofar = 0;
5561 c->u.a.message = NULL;
5562 c->u.a.outstanding_requests = 0;
5563 add234(ssh->channels, c);
5564 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5565 PKT_INT, c->remoteid, PKT_INT, c->localid,
5570 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5572 /* Remote side is trying to open a channel to talk to a
5573 * forwarded port. Give them back a local channel number. */
5574 struct ssh_rportfwd pf, *pfp;
5580 remoteid = ssh_pkt_getuint32(pktin);
5581 ssh_pkt_getstring(pktin, &host, &hostsize);
5582 port = ssh_pkt_getuint32(pktin);
5584 pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host));
5586 pfp = find234(ssh->rportfwds, &pf, NULL);
5589 logeventf(ssh, "Rejected remote port open request for %s:%d",
5591 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5592 PKT_INT, remoteid, PKT_END);
5594 struct ssh_channel *c = snew(struct ssh_channel);
5597 logeventf(ssh, "Received remote port open request for %s:%d",
5599 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5600 c, ssh->conf, pfp->pfrec->addressfamily);
5602 logeventf(ssh, "Port open failed: %s", err);
5605 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5606 PKT_INT, remoteid, PKT_END);
5608 c->remoteid = remoteid;
5609 c->halfopen = FALSE;
5610 c->localid = alloc_channel_id(ssh);
5612 c->pending_eof = FALSE;
5613 c->throttling_conn = 0;
5614 c->type = CHAN_SOCKDATA; /* identify channel type */
5615 add234(ssh->channels, c);
5616 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5617 PKT_INT, c->remoteid, PKT_INT,
5618 c->localid, PKT_END);
5619 logevent("Forwarded port opened successfully");
5626 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5628 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5629 unsigned int localid = ssh_pkt_getuint32(pktin);
5630 struct ssh_channel *c;
5632 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5633 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5634 c->remoteid = localid;
5635 c->halfopen = FALSE;
5636 c->type = CHAN_SOCKDATA;
5637 c->throttling_conn = 0;
5638 pfd_confirm(c->u.pfd.pf);
5641 if (c && c->pending_eof) {
5643 * We have a pending close on this channel,
5644 * which we decided on before the server acked
5645 * the channel open. So now we know the
5646 * remoteid, we can close it again.
5648 ssh_channel_try_eof(c);
5652 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5654 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5655 struct ssh_channel *c;
5657 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5658 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5659 logevent("Forwarded connection refused by server");
5660 pfd_close(c->u.pfd.pf);
5661 del234(ssh->channels, c);
5666 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5668 /* Remote side closes a channel. */
5669 unsigned i = ssh_pkt_getuint32(pktin);
5670 struct ssh_channel *c;
5671 c = find234(ssh->channels, &i, ssh_channelfind);
5672 if (c && !c->halfopen) {
5674 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5675 !(c->closes & CLOSES_RCVD_EOF)) {
5677 * Received CHANNEL_CLOSE, which we translate into
5680 int send_close = FALSE;
5682 c->closes |= CLOSES_RCVD_EOF;
5687 x11_send_eof(c->u.x11.xconn);
5693 pfd_send_eof(c->u.pfd.pf);
5702 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5703 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5705 c->closes |= CLOSES_SENT_EOF;
5709 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5710 !(c->closes & CLOSES_RCVD_CLOSE)) {
5712 if (!(c->closes & CLOSES_SENT_EOF)) {
5713 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5714 " for which we never sent CHANNEL_CLOSE\n", i));
5717 c->closes |= CLOSES_RCVD_CLOSE;
5720 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5721 !(c->closes & CLOSES_SENT_CLOSE)) {
5722 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5723 PKT_INT, c->remoteid, PKT_END);
5724 c->closes |= CLOSES_SENT_CLOSE;
5727 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5728 ssh_channel_destroy(c);
5730 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5731 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5732 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5737 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5739 /* Data sent down one of our channels. */
5740 int i = ssh_pkt_getuint32(pktin);
5743 struct ssh_channel *c;
5745 ssh_pkt_getstring(pktin, &p, &len);
5747 c = find234(ssh->channels, &i, ssh_channelfind);
5752 bufsize = x11_send(c->u.x11.xconn, p, len);
5755 bufsize = pfd_send(c->u.pfd.pf, p, len);
5758 /* Data for an agent message. Buffer it. */
5760 if (c->u.a.lensofar < 4) {
5761 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5762 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5766 c->u.a.lensofar += l;
5768 if (c->u.a.lensofar == 4) {
5770 4 + GET_32BIT(c->u.a.msglen);
5771 c->u.a.message = snewn(c->u.a.totallen,
5773 memcpy(c->u.a.message, c->u.a.msglen, 4);
5775 if (c->u.a.lensofar >= 4 && len > 0) {
5777 min(c->u.a.totallen - c->u.a.lensofar,
5779 memcpy(c->u.a.message + c->u.a.lensofar, p,
5783 c->u.a.lensofar += l;
5785 if (c->u.a.lensofar == c->u.a.totallen) {
5788 c->u.a.outstanding_requests++;
5789 if (agent_query(c->u.a.message,
5792 ssh_agentf_callback, c))
5793 ssh_agentf_callback(c, reply, replylen);
5794 sfree(c->u.a.message);
5795 c->u.a.lensofar = 0;
5798 bufsize = 0; /* agent channels never back up */
5801 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5802 c->throttling_conn = 1;
5803 ssh_throttle_conn(ssh, +1);
5808 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5810 ssh->exitcode = ssh_pkt_getuint32(pktin);
5811 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5812 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5814 * In case `helpful' firewalls or proxies tack
5815 * extra human-readable text on the end of the
5816 * session which we might mistake for another
5817 * encrypted packet, we close the session once
5818 * we've sent EXIT_CONFIRMATION.
5820 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5823 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5824 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5826 struct Packet *pktout = (struct Packet *)data;
5828 unsigned int arg = 0;
5829 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5830 if (i == lenof(ssh_ttymodes)) return;
5831 switch (ssh_ttymodes[i].type) {
5833 arg = ssh_tty_parse_specchar(val);
5836 arg = ssh_tty_parse_boolean(val);
5839 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5840 ssh2_pkt_addbyte(pktout, arg);
5843 int ssh_agent_forwarding_permitted(Ssh ssh)
5845 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5848 static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen,
5849 struct Packet *pktin)
5851 crBegin(ssh->do_ssh1_connection_crstate);
5853 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5854 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5855 ssh1_smsg_stdout_stderr_data;
5857 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5858 ssh1_msg_channel_open_confirmation;
5859 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5860 ssh1_msg_channel_open_failure;
5861 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5862 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5863 ssh1_msg_channel_close;
5864 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5865 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5867 if (ssh_agent_forwarding_permitted(ssh)) {
5868 logevent("Requesting agent forwarding");
5869 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5873 if (pktin->type != SSH1_SMSG_SUCCESS
5874 && pktin->type != SSH1_SMSG_FAILURE) {
5875 bombout(("Protocol confusion"));
5877 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5878 logevent("Agent forwarding refused");
5880 logevent("Agent forwarding enabled");
5881 ssh->agentfwd_enabled = TRUE;
5882 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5886 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5888 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5890 if (!ssh->x11disp) {
5891 /* FIXME: return an error message from x11_setup_display */
5892 logevent("X11 forwarding not enabled: unable to"
5893 " initialise X display");
5895 ssh->x11auth = x11_invent_fake_auth
5896 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5897 ssh->x11auth->disp = ssh->x11disp;
5899 logevent("Requesting X11 forwarding");
5900 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5901 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5902 PKT_STR, ssh->x11auth->protoname,
5903 PKT_STR, ssh->x11auth->datastring,
5904 PKT_INT, ssh->x11disp->screennum,
5907 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5908 PKT_STR, ssh->x11auth->protoname,
5909 PKT_STR, ssh->x11auth->datastring,
5915 if (pktin->type != SSH1_SMSG_SUCCESS
5916 && pktin->type != SSH1_SMSG_FAILURE) {
5917 bombout(("Protocol confusion"));
5919 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5920 logevent("X11 forwarding refused");
5922 logevent("X11 forwarding enabled");
5923 ssh->X11_fwd_enabled = TRUE;
5924 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5929 ssh_setup_portfwd(ssh, ssh->conf);
5930 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5932 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5934 /* Unpick the terminal-speed string. */
5935 /* XXX perhaps we should allow no speeds to be sent. */
5936 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5937 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5938 /* Send the pty request. */
5939 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5940 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5941 ssh_pkt_adduint32(pkt, ssh->term_height);
5942 ssh_pkt_adduint32(pkt, ssh->term_width);
5943 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5944 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5945 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5946 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5947 ssh_pkt_adduint32(pkt, ssh->ispeed);
5948 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5949 ssh_pkt_adduint32(pkt, ssh->ospeed);
5950 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5952 ssh->state = SSH_STATE_INTERMED;
5956 if (pktin->type != SSH1_SMSG_SUCCESS
5957 && pktin->type != SSH1_SMSG_FAILURE) {
5958 bombout(("Protocol confusion"));
5960 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5961 c_write_str(ssh, "Server refused to allocate pty\r\n");
5962 ssh->editing = ssh->echoing = 1;
5964 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5965 ssh->ospeed, ssh->ispeed);
5966 ssh->got_pty = TRUE;
5969 ssh->editing = ssh->echoing = 1;
5972 if (conf_get_int(ssh->conf, CONF_compression)) {
5973 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5977 if (pktin->type != SSH1_SMSG_SUCCESS
5978 && pktin->type != SSH1_SMSG_FAILURE) {
5979 bombout(("Protocol confusion"));
5981 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5982 c_write_str(ssh, "Server refused to compress\r\n");
5984 logevent("Started compression");
5985 ssh->v1_compressing = TRUE;
5986 ssh->cs_comp_ctx = zlib_compress_init();
5987 logevent("Initialised zlib (RFC1950) compression");
5988 ssh->sc_comp_ctx = zlib_decompress_init();
5989 logevent("Initialised zlib (RFC1950) decompression");
5993 * Start the shell or command.
5995 * Special case: if the first-choice command is an SSH-2
5996 * subsystem (hence not usable here) and the second choice
5997 * exists, we fall straight back to that.
6000 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
6002 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
6003 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
6004 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
6005 ssh->fallback_cmd = TRUE;
6008 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
6010 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
6011 logevent("Started session");
6014 ssh->state = SSH_STATE_SESSION;
6015 if (ssh->size_needed)
6016 ssh_size(ssh, ssh->term_width, ssh->term_height);
6017 if (ssh->eof_needed)
6018 ssh_special(ssh, TS_EOF);
6021 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
6023 ssh->channels = newtree234(ssh_channelcmp);
6027 * By this point, most incoming packets are already being
6028 * handled by the dispatch table, and we need only pay
6029 * attention to the unusual ones.
6034 if (pktin->type == SSH1_SMSG_SUCCESS) {
6035 /* may be from EXEC_SHELL on some servers */
6036 } else if (pktin->type == SSH1_SMSG_FAILURE) {
6037 /* may be from EXEC_SHELL on some servers
6038 * if no pty is available or in other odd cases. Ignore */
6040 bombout(("Strange packet received: type %d", pktin->type));
6045 int len = min(inlen, 512);
6046 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
6047 PKT_INT, len, PKT_DATA, in, len,
6059 * Handle the top-level SSH-2 protocol.
6061 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
6066 ssh_pkt_getstring(pktin, &msg, &msglen);
6067 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
6070 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
6072 /* log reason code in disconnect message */
6076 ssh_pkt_getstring(pktin, &msg, &msglen);
6077 bombout(("Server sent disconnect message:\n\"%.*s\"",
6078 msglen, NULLTOEMPTY(msg)));
6081 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
6083 /* Do nothing, because we're ignoring it! Duhh. */
6086 static void ssh1_protocol_setup(Ssh ssh)
6091 * Most messages are handled by the coroutines.
6093 for (i = 0; i < 256; i++)
6094 ssh->packet_dispatch[i] = NULL;
6097 * These special message types we install handlers for.
6099 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
6100 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
6101 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
6104 static void ssh1_protocol(Ssh ssh, const void *vin, int inlen,
6105 struct Packet *pktin)
6107 const unsigned char *in = (const unsigned char *)vin;
6108 if (ssh->state == SSH_STATE_CLOSED)
6111 if (pktin && ssh->packet_dispatch[pktin->type]) {
6112 ssh->packet_dispatch[pktin->type](ssh, pktin);
6116 if (!ssh->protocol_initial_phase_done) {
6117 if (do_ssh1_login(ssh, in, inlen, pktin))
6118 ssh->protocol_initial_phase_done = TRUE;
6123 do_ssh1_connection(ssh, in, inlen, pktin);
6127 * Utility routines for decoding comma-separated strings in KEXINIT.
6129 static int first_in_commasep_string(char const *needle, char const *haystack,
6133 if (!needle || !haystack) /* protect against null pointers */
6135 needlen = strlen(needle);
6137 if (haylen >= needlen && /* haystack is long enough */
6138 !memcmp(needle, haystack, needlen) && /* initial match */
6139 (haylen == needlen || haystack[needlen] == ',')
6140 /* either , or EOS follows */
6146 static int in_commasep_string(char const *needle, char const *haystack,
6151 if (!needle || !haystack) /* protect against null pointers */
6154 * Is it at the start of the string?
6156 if (first_in_commasep_string(needle, haystack, haylen))
6159 * If not, search for the next comma and resume after that.
6160 * If no comma found, terminate.
6162 p = memchr(haystack, ',', haylen);
6164 /* + 1 to skip over comma */
6165 return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
6169 * Add a value to the comma-separated string at the end of the packet.
6171 static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data)
6173 if (pkt->length - pkt->savedpos > 0)
6174 ssh_pkt_addstring_str(pkt, ",");
6175 ssh_pkt_addstring_str(pkt, data);
6180 * SSH-2 key derivation (RFC 4253 section 7.2).
6182 static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
6183 char chr, int keylen)
6185 const struct ssh_hash *h = ssh->kex->hash;
6193 /* Round up to the next multiple of hash length. */
6194 keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen;
6196 key = snewn(keylen_padded, unsigned char);
6198 /* First hlen bytes. */
6200 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6201 hash_mpint(h, s, K);
6202 h->bytes(s, H, h->hlen);
6203 h->bytes(s, &chr, 1);
6204 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6207 /* Subsequent blocks of hlen bytes. */
6208 if (keylen_padded > h->hlen) {
6212 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6213 hash_mpint(h, s, K);
6214 h->bytes(s, H, h->hlen);
6216 for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) {
6217 h->bytes(s, key + offset - h->hlen, h->hlen);
6219 h->final(s2, key + offset);
6225 /* Now clear any extra bytes of key material beyond the length
6226 * we're officially returning, because the caller won't know to
6228 if (keylen_padded > keylen)
6229 smemclr(key + keylen, keylen_padded - keylen);
6235 * Structure for constructing KEXINIT algorithm lists.
6237 #define MAXKEXLIST 16
6238 struct kexinit_algorithm {
6242 const struct ssh_kex *kex;
6245 const struct ssh_signkey *hostkey;
6247 const struct ssh2_cipher *cipher;
6251 const struct ssh_mac *mac;
6254 const struct ssh_compress *comp;
6259 * Find a slot in a KEXINIT algorithm list to use for a new algorithm.
6260 * If the algorithm is already in the list, return a pointer to its
6261 * entry, otherwise return an entry from the end of the list.
6262 * This assumes that every time a particular name is passed in, it
6263 * comes from the same string constant. If this isn't true, this
6264 * function may need to be rewritten to use strcmp() instead.
6266 static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm
6267 *list, const char *name)
6271 for (i = 0; i < MAXKEXLIST; i++)
6272 if (list[i].name == NULL || list[i].name == name) {
6273 list[i].name = name;
6276 assert(!"No space in KEXINIT list");
6281 * Handle the SSH-2 transport layer.
6283 static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen,
6284 struct Packet *pktin)
6286 const unsigned char *in = (const unsigned char *)vin;
6288 KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
6289 KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
6292 const char * kexlist_descr[NKEXLIST] = {
6293 "key exchange algorithm", "host key algorithm",
6294 "client-to-server cipher", "server-to-client cipher",
6295 "client-to-server MAC", "server-to-client MAC",
6296 "client-to-server compression method",
6297 "server-to-client compression method" };
6298 struct do_ssh2_transport_state {
6300 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6301 Bignum p, g, e, f, K;
6304 int kex_init_value, kex_reply_value;
6305 const struct ssh_mac **maclist;
6307 const struct ssh2_cipher *cscipher_tobe;
6308 const struct ssh2_cipher *sccipher_tobe;
6309 const struct ssh_mac *csmac_tobe;
6310 const struct ssh_mac *scmac_tobe;
6311 int csmac_etm_tobe, scmac_etm_tobe;
6312 const struct ssh_compress *cscomp_tobe;
6313 const struct ssh_compress *sccomp_tobe;
6314 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6315 int hostkeylen, siglen, rsakeylen;
6316 void *hkey; /* actual host key */
6317 void *rsakey; /* for RSA kex */
6318 void *eckey; /* for ECDH kex */
6319 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6320 int n_preferred_kex;
6321 const struct ssh_kexes *preferred_kex[KEX_MAX];
6322 int n_preferred_ciphers;
6323 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6324 const struct ssh_compress *preferred_comp;
6325 int userauth_succeeded; /* for delayed compression */
6326 int pending_compression;
6327 int got_session_id, activated_authconn;
6328 struct Packet *pktout;
6332 struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST];
6334 crState(do_ssh2_transport_state);
6336 assert(!ssh->bare_connection);
6340 s->cscipher_tobe = s->sccipher_tobe = NULL;
6341 s->csmac_tobe = s->scmac_tobe = NULL;
6342 s->cscomp_tobe = s->sccomp_tobe = NULL;
6344 s->got_session_id = s->activated_authconn = FALSE;
6345 s->userauth_succeeded = FALSE;
6346 s->pending_compression = FALSE;
6349 * Be prepared to work around the buggy MAC problem.
6351 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6352 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6354 s->maclist = macs, s->nmacs = lenof(macs);
6357 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6360 struct kexinit_algorithm *alg;
6363 * Set up the preferred key exchange. (NULL => warn below here)
6365 s->n_preferred_kex = 0;
6366 for (i = 0; i < KEX_MAX; i++) {
6367 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6369 s->preferred_kex[s->n_preferred_kex++] =
6370 &ssh_diffiehellman_gex;
6373 s->preferred_kex[s->n_preferred_kex++] =
6374 &ssh_diffiehellman_group14;
6377 s->preferred_kex[s->n_preferred_kex++] =
6378 &ssh_diffiehellman_group1;
6381 s->preferred_kex[s->n_preferred_kex++] =
6385 s->preferred_kex[s->n_preferred_kex++] =
6389 /* Flag for later. Don't bother if it's the last in
6391 if (i < KEX_MAX - 1) {
6392 s->preferred_kex[s->n_preferred_kex++] = NULL;
6399 * Set up the preferred ciphers. (NULL => warn below here)
6401 s->n_preferred_ciphers = 0;
6402 for (i = 0; i < CIPHER_MAX; i++) {
6403 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6404 case CIPHER_BLOWFISH:
6405 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6408 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6409 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6413 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6416 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6418 case CIPHER_ARCFOUR:
6419 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6421 case CIPHER_CHACHA20:
6422 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp;
6425 /* Flag for later. Don't bother if it's the last in
6427 if (i < CIPHER_MAX - 1) {
6428 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6435 * Set up preferred compression.
6437 if (conf_get_int(ssh->conf, CONF_compression))
6438 s->preferred_comp = &ssh_zlib;
6440 s->preferred_comp = &ssh_comp_none;
6443 * Enable queueing of outgoing auth- or connection-layer
6444 * packets while we are in the middle of a key exchange.
6446 ssh->queueing = TRUE;
6449 * Flag that KEX is in progress.
6451 ssh->kex_in_progress = TRUE;
6453 for (i = 0; i < NKEXLIST; i++)
6454 for (j = 0; j < MAXKEXLIST; j++)
6455 s->kexlists[i][j].name = NULL;
6456 /* List key exchange algorithms. */
6458 for (i = 0; i < s->n_preferred_kex; i++) {
6459 const struct ssh_kexes *k = s->preferred_kex[i];
6460 if (!k) warn = TRUE;
6461 else for (j = 0; j < k->nkexes; j++) {
6462 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX],
6464 alg->u.kex.kex = k->list[j];
6465 alg->u.kex.warn = warn;
6468 /* List server host key algorithms. */
6469 if (!s->got_session_id) {
6471 * In the first key exchange, we list all the algorithms
6472 * we're prepared to cope with, but prefer those algorithms
6473 * for which we have a host key for this host.
6475 for (i = 0; i < lenof(hostkey_algs); i++) {
6476 if (have_ssh_host_key(ssh->savedhost, ssh->savedport,
6477 hostkey_algs[i]->keytype)) {
6478 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6479 hostkey_algs[i]->name);
6480 alg->u.hostkey = hostkey_algs[i];
6483 for (i = 0; i < lenof(hostkey_algs); i++) {
6484 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6485 hostkey_algs[i]->name);
6486 alg->u.hostkey = hostkey_algs[i];
6490 * In subsequent key exchanges, we list only the kex
6491 * algorithm that was selected in the first key exchange,
6492 * so that we keep getting the same host key and hence
6493 * don't have to interrupt the user's session to ask for
6497 alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY],
6498 ssh->hostkey->name);
6499 alg->u.hostkey = ssh->hostkey;
6501 /* List encryption algorithms (client->server then server->client). */
6502 for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) {
6505 alg = ssh2_kexinit_addalg(s->kexlists[k], "none");
6506 alg->u.cipher.cipher = NULL;
6507 alg->u.cipher.warn = warn;
6508 #endif /* FUZZING */
6509 for (i = 0; i < s->n_preferred_ciphers; i++) {
6510 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6511 if (!c) warn = TRUE;
6512 else for (j = 0; j < c->nciphers; j++) {
6513 alg = ssh2_kexinit_addalg(s->kexlists[k],
6515 alg->u.cipher.cipher = c->list[j];
6516 alg->u.cipher.warn = warn;
6520 /* List MAC algorithms (client->server then server->client). */
6521 for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) {
6523 alg = ssh2_kexinit_addalg(s->kexlists[j], "none");
6524 alg->u.mac.mac = NULL;
6525 alg->u.mac.etm = FALSE;
6526 #endif /* FUZZING */
6527 for (i = 0; i < s->nmacs; i++) {
6528 alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name);
6529 alg->u.mac.mac = s->maclist[i];
6530 alg->u.mac.etm = FALSE;
6532 for (i = 0; i < s->nmacs; i++)
6533 /* For each MAC, there may also be an ETM version,
6534 * which we list second. */
6535 if (s->maclist[i]->etm_name) {
6536 alg = ssh2_kexinit_addalg(s->kexlists[j],
6537 s->maclist[i]->etm_name);
6538 alg->u.mac.mac = s->maclist[i];
6539 alg->u.mac.etm = TRUE;
6542 /* List client->server compression algorithms,
6543 * then server->client compression algorithms. (We use the
6544 * same set twice.) */
6545 for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) {
6546 assert(lenof(compressions) > 1);
6547 /* Prefer non-delayed versions */
6548 alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name);
6549 alg->u.comp = s->preferred_comp;
6550 /* We don't even list delayed versions of algorithms until
6551 * they're allowed to be used, to avoid a race. See the end of
6553 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6554 alg = ssh2_kexinit_addalg(s->kexlists[j],
6555 s->preferred_comp->delayed_name);
6556 alg->u.comp = s->preferred_comp;
6558 for (i = 0; i < lenof(compressions); i++) {
6559 const struct ssh_compress *c = compressions[i];
6560 alg = ssh2_kexinit_addalg(s->kexlists[j], c->name);
6562 if (s->userauth_succeeded && c->delayed_name) {
6563 alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name);
6569 * Construct and send our key exchange packet.
6571 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6572 for (i = 0; i < 16; i++)
6573 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6574 for (i = 0; i < NKEXLIST; i++) {
6575 ssh2_pkt_addstring_start(s->pktout);
6576 for (j = 0; j < MAXKEXLIST; j++) {
6577 if (s->kexlists[i][j].name == NULL) break;
6578 ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name);
6581 /* List client->server languages. Empty list. */
6582 ssh2_pkt_addstring_start(s->pktout);
6583 /* List server->client languages. Empty list. */
6584 ssh2_pkt_addstring_start(s->pktout);
6585 /* First KEX packet does _not_ follow, because we're not that brave. */
6586 ssh2_pkt_addbool(s->pktout, FALSE);
6588 ssh2_pkt_adduint32(s->pktout, 0);
6591 s->our_kexinitlen = s->pktout->length - 5;
6592 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6593 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6595 ssh2_pkt_send_noqueue(ssh, s->pktout);
6598 crWaitUntilV(pktin);
6601 * Now examine the other side's KEXINIT to see what we're up
6608 if (pktin->type != SSH2_MSG_KEXINIT) {
6609 bombout(("expected key exchange packet from server"));
6613 ssh->hostkey = NULL;
6614 s->cscipher_tobe = NULL;
6615 s->sccipher_tobe = NULL;
6616 s->csmac_tobe = NULL;
6617 s->scmac_tobe = NULL;
6618 s->cscomp_tobe = NULL;
6619 s->sccomp_tobe = NULL;
6620 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6622 pktin->savedpos += 16; /* skip garbage cookie */
6625 for (i = 0; i < NKEXLIST; i++) {
6626 ssh_pkt_getstring(pktin, &str, &len);
6628 bombout(("KEXINIT packet was incomplete"));
6632 /* If we've already selected a cipher which requires a
6633 * particular MAC, then just select that, and don't even
6634 * bother looking through the server's KEXINIT string for
6636 if (i == KEXLIST_CSMAC && s->cscipher_tobe &&
6637 s->cscipher_tobe->required_mac) {
6638 s->csmac_tobe = s->cscipher_tobe->required_mac;
6639 s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name);
6642 if (i == KEXLIST_SCMAC && s->sccipher_tobe &&
6643 s->sccipher_tobe->required_mac) {
6644 s->scmac_tobe = s->sccipher_tobe->required_mac;
6645 s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name);
6649 for (j = 0; j < MAXKEXLIST; j++) {
6650 struct kexinit_algorithm *alg = &s->kexlists[i][j];
6651 if (alg->name == NULL) break;
6652 if (in_commasep_string(alg->name, str, len)) {
6653 /* We've found a matching algorithm. */
6654 if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) {
6655 /* Check if we might need to ignore first kex pkt */
6657 !first_in_commasep_string(alg->name, str, len))
6660 if (i == KEXLIST_KEX) {
6661 ssh->kex = alg->u.kex.kex;
6662 s->warn_kex = alg->u.kex.warn;
6663 } else if (i == KEXLIST_HOSTKEY) {
6664 ssh->hostkey = alg->u.hostkey;
6665 } else if (i == KEXLIST_CSCIPHER) {
6666 s->cscipher_tobe = alg->u.cipher.cipher;
6667 s->warn_cscipher = alg->u.cipher.warn;
6668 } else if (i == KEXLIST_SCCIPHER) {
6669 s->sccipher_tobe = alg->u.cipher.cipher;
6670 s->warn_sccipher = alg->u.cipher.warn;
6671 } else if (i == KEXLIST_CSMAC) {
6672 s->csmac_tobe = alg->u.mac.mac;
6673 s->csmac_etm_tobe = alg->u.mac.etm;
6674 } else if (i == KEXLIST_SCMAC) {
6675 s->scmac_tobe = alg->u.mac.mac;
6676 s->scmac_etm_tobe = alg->u.mac.etm;
6677 } else if (i == KEXLIST_CSCOMP) {
6678 s->cscomp_tobe = alg->u.comp;
6679 } else if (i == KEXLIST_SCCOMP) {
6680 s->sccomp_tobe = alg->u.comp;
6684 if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) &&
6685 in_commasep_string(alg->u.comp->delayed_name, str, len))
6686 s->pending_compression = TRUE; /* try this later */
6688 bombout(("Couldn't agree a %s ((available: %.*s)",
6689 kexlist_descr[i], len, str));
6693 if (i == KEXLIST_HOSTKEY) {
6697 * In addition to deciding which host key we're
6698 * actually going to use, we should make a list of the
6699 * host keys offered by the server which we _don't_
6700 * have cached. These will be offered as cross-
6701 * certification options by ssh_get_specials.
6703 * We also count the key we're currently using for KEX
6704 * as one we've already got, because by the time this
6705 * menu becomes visible, it will be.
6707 ssh->n_uncert_hostkeys = 0;
6709 for (j = 0; j < lenof(hostkey_algs); j++) {
6710 if (hostkey_algs[j] != ssh->hostkey &&
6711 in_commasep_string(hostkey_algs[j]->name, str, len) &&
6712 !have_ssh_host_key(ssh->savedhost, ssh->savedport,
6713 hostkey_algs[j]->keytype)) {
6714 ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j;
6720 if (s->pending_compression) {
6721 logevent("Server supports delayed compression; "
6722 "will try this later");
6724 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6725 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6726 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6728 ssh->exhash = ssh->kex->hash->init();
6729 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6730 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6731 hash_string(ssh->kex->hash, ssh->exhash,
6732 s->our_kexinit, s->our_kexinitlen);
6733 sfree(s->our_kexinit);
6734 /* Include the type byte in the hash of server's KEXINIT */
6735 hash_string(ssh->kex->hash, ssh->exhash,
6736 pktin->body - 1, pktin->length + 1);
6739 ssh_set_frozen(ssh, 1);
6740 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6742 ssh_dialog_callback, ssh);
6743 if (s->dlgret < 0) {
6747 bombout(("Unexpected data from server while"
6748 " waiting for user response"));
6751 } while (pktin || inlen > 0);
6752 s->dlgret = ssh->user_response;
6754 ssh_set_frozen(ssh, 0);
6755 if (s->dlgret == 0) {
6756 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6762 if (s->warn_cscipher) {
6763 ssh_set_frozen(ssh, 1);
6764 s->dlgret = askalg(ssh->frontend,
6765 "client-to-server cipher",
6766 s->cscipher_tobe->name,
6767 ssh_dialog_callback, ssh);
6768 if (s->dlgret < 0) {
6772 bombout(("Unexpected data from server while"
6773 " waiting for user response"));
6776 } while (pktin || inlen > 0);
6777 s->dlgret = ssh->user_response;
6779 ssh_set_frozen(ssh, 0);
6780 if (s->dlgret == 0) {
6781 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6787 if (s->warn_sccipher) {
6788 ssh_set_frozen(ssh, 1);
6789 s->dlgret = askalg(ssh->frontend,
6790 "server-to-client cipher",
6791 s->sccipher_tobe->name,
6792 ssh_dialog_callback, ssh);
6793 if (s->dlgret < 0) {
6797 bombout(("Unexpected data from server while"
6798 " waiting for user response"));
6801 } while (pktin || inlen > 0);
6802 s->dlgret = ssh->user_response;
6804 ssh_set_frozen(ssh, 0);
6805 if (s->dlgret == 0) {
6806 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6812 if (s->ignorepkt) /* first_kex_packet_follows */
6813 crWaitUntilV(pktin); /* Ignore packet */
6816 if (ssh->kex->main_type == KEXTYPE_DH) {
6818 * Work out the number of bits of key we will need from the
6819 * key exchange. We start with the maximum key length of
6825 csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0;
6826 scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0;
6827 s->nbits = (csbits > scbits ? csbits : scbits);
6829 /* The keys only have hlen-bit entropy, since they're based on
6830 * a hash. So cap the key size at hlen bits. */
6831 if (s->nbits > ssh->kex->hash->hlen * 8)
6832 s->nbits = ssh->kex->hash->hlen * 8;
6835 * If we're doing Diffie-Hellman group exchange, start by
6836 * requesting a group.
6838 if (dh_is_gex(ssh->kex)) {
6839 logevent("Doing Diffie-Hellman group exchange");
6840 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6842 * Work out how big a DH group we will need to allow that
6845 s->pbits = 512 << ((s->nbits - 1) / 64);
6846 if (s->pbits < DH_MIN_SIZE)
6847 s->pbits = DH_MIN_SIZE;
6848 if (s->pbits > DH_MAX_SIZE)
6849 s->pbits = DH_MAX_SIZE;
6850 if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) {
6851 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
6852 ssh2_pkt_adduint32(s->pktout, s->pbits);
6854 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6855 ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE);
6856 ssh2_pkt_adduint32(s->pktout, s->pbits);
6857 ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE);
6859 ssh2_pkt_send_noqueue(ssh, s->pktout);
6861 crWaitUntilV(pktin);
6862 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6863 bombout(("expected key exchange group packet from server"));
6866 s->p = ssh2_pkt_getmp(pktin);
6867 s->g = ssh2_pkt_getmp(pktin);
6868 if (!s->p || !s->g) {
6869 bombout(("unable to read mp-ints from incoming group packet"));
6872 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6873 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6874 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6876 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6877 ssh->kex_ctx = dh_setup_group(ssh->kex);
6878 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6879 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6880 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6881 ssh->kex->groupname);
6884 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6885 ssh->kex->hash->text_name);
6887 * Now generate and send e for Diffie-Hellman.
6889 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6890 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6891 s->pktout = ssh2_pkt_init(s->kex_init_value);
6892 ssh2_pkt_addmp(s->pktout, s->e);
6893 ssh2_pkt_send_noqueue(ssh, s->pktout);
6895 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6896 crWaitUntilV(pktin);
6897 if (pktin->type != s->kex_reply_value) {
6898 bombout(("expected key exchange reply packet from server"));
6901 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6902 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6903 if (!s->hostkeydata) {
6904 bombout(("unable to parse key exchange reply packet"));
6907 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6908 s->hostkeydata, s->hostkeylen);
6909 s->f = ssh2_pkt_getmp(pktin);
6911 bombout(("unable to parse key exchange reply packet"));
6914 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6916 bombout(("unable to parse key exchange reply packet"));
6921 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6923 bombout(("key exchange reply failed validation: %s", err));
6927 s->K = dh_find_K(ssh->kex_ctx, s->f);
6929 /* We assume everything from now on will be quick, and it might
6930 * involve user interaction. */
6931 set_busy_status(ssh->frontend, BUSY_NOT);
6933 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6934 if (dh_is_gex(ssh->kex)) {
6935 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6936 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE);
6937 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6938 if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX))
6939 hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE);
6940 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6941 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6943 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6944 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6946 dh_cleanup(ssh->kex_ctx);
6948 if (dh_is_gex(ssh->kex)) {
6952 } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
6954 logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s",
6955 ssh_ecdhkex_curve_textname(ssh->kex),
6956 ssh->kex->hash->text_name);
6957 ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
6959 s->eckey = ssh_ecdhkex_newkey(ssh->kex);
6961 bombout(("Unable to generate key for ECDH"));
6967 int publicPointLength;
6968 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
6970 ssh_ecdhkex_freekey(s->eckey);
6971 bombout(("Unable to encode public key for ECDH"));
6974 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
6975 ssh2_pkt_addstring_start(s->pktout);
6976 ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
6980 ssh2_pkt_send_noqueue(ssh, s->pktout);
6982 crWaitUntilV(pktin);
6983 if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
6984 ssh_ecdhkex_freekey(s->eckey);
6985 bombout(("expected ECDH reply packet from server"));
6989 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6990 if (!s->hostkeydata) {
6991 bombout(("unable to parse ECDH reply packet"));
6994 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6995 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
6996 s->hostkeydata, s->hostkeylen);
7000 int publicPointLength;
7001 publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
7003 ssh_ecdhkex_freekey(s->eckey);
7004 bombout(("Unable to encode public key for ECDH hash"));
7007 hash_string(ssh->kex->hash, ssh->exhash,
7008 publicPoint, publicPointLength);
7015 ssh_pkt_getstring(pktin, &keydata, &keylen);
7017 bombout(("unable to parse ECDH reply packet"));
7020 hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
7021 s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
7023 ssh_ecdhkex_freekey(s->eckey);
7024 bombout(("point received in ECDH was not valid"));
7029 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7031 bombout(("unable to parse key exchange reply packet"));
7035 ssh_ecdhkex_freekey(s->eckey);
7037 logeventf(ssh, "Doing RSA key exchange with hash %s",
7038 ssh->kex->hash->text_name);
7039 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
7041 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
7044 crWaitUntilV(pktin);
7045 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
7046 bombout(("expected RSA public key packet from server"));
7050 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
7051 if (!s->hostkeydata) {
7052 bombout(("unable to parse RSA public key packet"));
7055 hash_string(ssh->kex->hash, ssh->exhash,
7056 s->hostkeydata, s->hostkeylen);
7057 s->hkey = ssh->hostkey->newkey(ssh->hostkey,
7058 s->hostkeydata, s->hostkeylen);
7062 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
7064 bombout(("unable to parse RSA public key packet"));
7067 s->rsakeydata = snewn(s->rsakeylen, char);
7068 memcpy(s->rsakeydata, keydata, s->rsakeylen);
7071 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
7073 sfree(s->rsakeydata);
7074 bombout(("unable to parse RSA public key from server"));
7078 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
7081 * Next, set up a shared secret K, of precisely KLEN -
7082 * 2*HLEN - 49 bits, where KLEN is the bit length of the
7083 * RSA key modulus and HLEN is the bit length of the hash
7087 int klen = ssh_rsakex_klen(s->rsakey);
7088 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
7090 unsigned char *kstr1, *kstr2, *outstr;
7091 int kstr1len, kstr2len, outstrlen;
7093 s->K = bn_power_2(nbits - 1);
7095 for (i = 0; i < nbits; i++) {
7097 byte = random_byte();
7099 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
7103 * Encode this as an mpint.
7105 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
7106 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
7107 PUT_32BIT(kstr2, kstr1len);
7108 memcpy(kstr2 + 4, kstr1, kstr1len);
7111 * Encrypt it with the given RSA key.
7113 outstrlen = (klen + 7) / 8;
7114 outstr = snewn(outstrlen, unsigned char);
7115 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
7116 outstr, outstrlen, s->rsakey);
7119 * And send it off in a return packet.
7121 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
7122 ssh2_pkt_addstring_start(s->pktout);
7123 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
7124 ssh2_pkt_send_noqueue(ssh, s->pktout);
7126 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
7133 ssh_rsakex_freekey(s->rsakey);
7135 crWaitUntilV(pktin);
7136 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
7137 sfree(s->rsakeydata);
7138 bombout(("expected signature packet from server"));
7142 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
7144 bombout(("unable to parse signature packet"));
7148 sfree(s->rsakeydata);
7151 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
7152 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
7153 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
7155 ssh->kex_ctx = NULL;
7158 debug(("Exchange hash is:\n"));
7159 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7163 bombout(("Server's host key is invalid"));
7167 if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
7168 (char *)s->exchange_hash,
7169 ssh->kex->hash->hlen)) {
7171 bombout(("Server's host key did not match the signature supplied"));
7176 s->keystr = ssh->hostkey->fmtkey(s->hkey);
7177 if (!s->got_session_id) {
7179 * Authenticate remote host: verify host key. (We've already
7180 * checked the signature of the exchange hash.)
7182 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7183 logevent("Host key fingerprint is:");
7184 logevent(s->fingerprint);
7185 /* First check against manually configured host keys. */
7186 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
7187 ssh->hostkey, s->hkey);
7188 if (s->dlgret == 0) { /* did not match */
7189 bombout(("Host key did not appear in manually configured list"));
7191 } else if (s->dlgret < 0) { /* none configured; use standard handling */
7192 ssh_set_frozen(ssh, 1);
7193 s->dlgret = verify_ssh_host_key(ssh->frontend,
7194 ssh->savedhost, ssh->savedport,
7195 ssh->hostkey->keytype, s->keystr,
7197 ssh_dialog_callback, ssh);
7201 if (s->dlgret < 0) {
7205 bombout(("Unexpected data from server while waiting"
7206 " for user host key response"));
7209 } while (pktin || inlen > 0);
7210 s->dlgret = ssh->user_response;
7212 ssh_set_frozen(ssh, 0);
7213 if (s->dlgret == 0) {
7214 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
7219 sfree(s->fingerprint);
7221 * Save this host key, to check against the one presented in
7222 * subsequent rekeys.
7224 ssh->hostkey_str = s->keystr;
7225 } else if (ssh->cross_certifying) {
7226 s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey);
7227 logevent("Storing additional host key for this host:");
7228 logevent(s->fingerprint);
7229 store_host_key(ssh->savedhost, ssh->savedport,
7230 ssh->hostkey->keytype, s->keystr);
7231 ssh->cross_certifying = FALSE;
7233 * Don't forget to store the new key as the one we'll be
7234 * re-checking in future normal rekeys.
7236 ssh->hostkey_str = s->keystr;
7239 * In a rekey, we never present an interactive host key
7240 * verification request to the user. Instead, we simply
7241 * enforce that the key we're seeing this time is identical to
7242 * the one we saw before.
7244 if (strcmp(ssh->hostkey_str, s->keystr)) {
7246 bombout(("Host key was different in repeat key exchange"));
7252 ssh->hostkey->freekey(s->hkey);
7255 * The exchange hash from the very first key exchange is also
7256 * the session id, used in session key construction and
7259 if (!s->got_session_id) {
7260 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
7261 memcpy(ssh->v2_session_id, s->exchange_hash,
7262 sizeof(s->exchange_hash));
7263 ssh->v2_session_id_len = ssh->kex->hash->hlen;
7264 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
7265 s->got_session_id = TRUE;
7269 * Send SSH2_MSG_NEWKEYS.
7271 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
7272 ssh2_pkt_send_noqueue(ssh, s->pktout);
7273 ssh->outgoing_data_size = 0; /* start counting from here */
7276 * We've sent client NEWKEYS, so create and initialise
7277 * client-to-server session keys.
7279 if (ssh->cs_cipher_ctx)
7280 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7281 ssh->cscipher = s->cscipher_tobe;
7282 if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context();
7284 if (ssh->cs_mac_ctx)
7285 ssh->csmac->free_context(ssh->cs_mac_ctx);
7286 ssh->csmac = s->csmac_tobe;
7287 ssh->csmac_etm = s->csmac_etm_tobe;
7289 ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx);
7291 if (ssh->cs_comp_ctx)
7292 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7293 ssh->cscomp = s->cscomp_tobe;
7294 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
7297 * Set IVs on client-to-server keys. Here we use the exchange
7298 * hash from the _first_ key exchange.
7300 if (ssh->cscipher) {
7303 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C',
7304 ssh->cscipher->padded_keybytes);
7305 ssh->cscipher->setkey(ssh->cs_cipher_ctx, key);
7306 smemclr(key, ssh->cscipher->padded_keybytes);
7309 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A',
7310 ssh->cscipher->blksize);
7311 ssh->cscipher->setiv(ssh->cs_cipher_ctx, key);
7312 smemclr(key, ssh->cscipher->blksize);
7318 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E',
7319 ssh->csmac->keylen);
7320 ssh->csmac->setkey(ssh->cs_mac_ctx, key);
7321 smemclr(key, ssh->csmac->keylen);
7326 logeventf(ssh, "Initialised %.200s client->server encryption",
7327 ssh->cscipher->text_name);
7329 logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s",
7330 ssh->csmac->text_name,
7331 ssh->csmac_etm ? " (in ETM mode)" : "",
7332 ssh->cscipher->required_mac ? " (required by cipher)" : "");
7333 if (ssh->cscomp->text_name)
7334 logeventf(ssh, "Initialised %s compression",
7335 ssh->cscomp->text_name);
7338 * Now our end of the key exchange is complete, we can send all
7339 * our queued higher-layer packets.
7341 ssh->queueing = FALSE;
7342 ssh2_pkt_queuesend(ssh);
7345 * Expect SSH2_MSG_NEWKEYS from server.
7347 crWaitUntilV(pktin);
7348 if (pktin->type != SSH2_MSG_NEWKEYS) {
7349 bombout(("expected new-keys packet from server"));
7352 ssh->incoming_data_size = 0; /* start counting from here */
7355 * We've seen server NEWKEYS, so create and initialise
7356 * server-to-client session keys.
7358 if (ssh->sc_cipher_ctx)
7359 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7360 if (s->sccipher_tobe) {
7361 ssh->sccipher = s->sccipher_tobe;
7362 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
7365 if (ssh->sc_mac_ctx)
7366 ssh->scmac->free_context(ssh->sc_mac_ctx);
7367 if (s->scmac_tobe) {
7368 ssh->scmac = s->scmac_tobe;
7369 ssh->scmac_etm = s->scmac_etm_tobe;
7370 ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx);
7373 if (ssh->sc_comp_ctx)
7374 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7375 ssh->sccomp = s->sccomp_tobe;
7376 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
7379 * Set IVs on server-to-client keys. Here we use the exchange
7380 * hash from the _first_ key exchange.
7382 if (ssh->sccipher) {
7385 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D',
7386 ssh->sccipher->padded_keybytes);
7387 ssh->sccipher->setkey(ssh->sc_cipher_ctx, key);
7388 smemclr(key, ssh->sccipher->padded_keybytes);
7391 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B',
7392 ssh->sccipher->blksize);
7393 ssh->sccipher->setiv(ssh->sc_cipher_ctx, key);
7394 smemclr(key, ssh->sccipher->blksize);
7400 key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F',
7401 ssh->scmac->keylen);
7402 ssh->scmac->setkey(ssh->sc_mac_ctx, key);
7403 smemclr(key, ssh->scmac->keylen);
7407 logeventf(ssh, "Initialised %.200s server->client encryption",
7408 ssh->sccipher->text_name);
7410 logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s",
7411 ssh->scmac->text_name,
7412 ssh->scmac_etm ? " (in ETM mode)" : "",
7413 ssh->sccipher->required_mac ? " (required by cipher)" : "");
7414 if (ssh->sccomp->text_name)
7415 logeventf(ssh, "Initialised %s decompression",
7416 ssh->sccomp->text_name);
7419 * Free shared secret.
7424 * Update the specials menu to list the remaining uncertified host
7427 update_specials_menu(ssh->frontend);
7430 * Key exchange is over. Loop straight back round if we have a
7431 * deferred rekey reason.
7433 if (ssh->deferred_rekey_reason) {
7434 logevent(ssh->deferred_rekey_reason);
7436 ssh->deferred_rekey_reason = NULL;
7437 goto begin_key_exchange;
7441 * Otherwise, schedule a timer for our next rekey.
7443 ssh->kex_in_progress = FALSE;
7444 ssh->last_rekey = GETTICKCOUNT();
7445 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7446 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7450 * Now we're encrypting. Begin returning 1 to the protocol main
7451 * function so that other things can run on top of the
7452 * transport. If we ever see a KEXINIT, we must go back to the
7455 * We _also_ go back to the start if we see pktin==NULL and
7456 * inlen negative, because this is a special signal meaning
7457 * `initiate client-driven rekey', and `in' contains a message
7458 * giving the reason for the rekey.
7460 * inlen==-1 means always initiate a rekey;
7461 * inlen==-2 means that userauth has completed successfully and
7462 * we should consider rekeying (for delayed compression).
7464 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7465 (!pktin && inlen < 0))) {
7467 if (!ssh->protocol_initial_phase_done) {
7468 ssh->protocol_initial_phase_done = TRUE;
7470 * Allow authconn to initialise itself.
7472 do_ssh2_authconn(ssh, NULL, 0, NULL);
7477 logevent("Server initiated key re-exchange");
7481 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7482 * delayed compression, if it's available.
7484 * draft-miller-secsh-compression-delayed-00 says that you
7485 * negotiate delayed compression in the first key exchange, and
7486 * both sides start compressing when the server has sent
7487 * USERAUTH_SUCCESS. This has a race condition -- the server
7488 * can't know when the client has seen it, and thus which incoming
7489 * packets it should treat as compressed.
7491 * Instead, we do the initial key exchange without offering the
7492 * delayed methods, but note if the server offers them; when we
7493 * get here, if a delayed method was available that was higher
7494 * on our list than what we got, we initiate a rekey in which we
7495 * _do_ list the delayed methods (and hopefully get it as a
7496 * result). Subsequent rekeys will do the same.
7498 assert(!s->userauth_succeeded); /* should only happen once */
7499 s->userauth_succeeded = TRUE;
7500 if (!s->pending_compression)
7501 /* Can't see any point rekeying. */
7502 goto wait_for_rekey; /* this is utterly horrid */
7503 /* else fall through to rekey... */
7504 s->pending_compression = FALSE;
7507 * Now we've decided to rekey.
7509 * Special case: if the server bug is set that doesn't
7510 * allow rekeying, we give a different log message and
7511 * continue waiting. (If such a server _initiates_ a rekey,
7512 * we process it anyway!)
7514 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7515 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7517 /* Reset the counters, so that at least this message doesn't
7518 * hit the event log _too_ often. */
7519 ssh->outgoing_data_size = 0;
7520 ssh->incoming_data_size = 0;
7521 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7523 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7526 goto wait_for_rekey; /* this is still utterly horrid */
7528 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7531 goto begin_key_exchange;
7537 * Add data to an SSH-2 channel output buffer.
7539 static void ssh2_add_channel_data(struct ssh_channel *c, const char *buf,
7542 bufchain_add(&c->v.v2.outbuffer, buf, len);
7546 * Attempt to send data on an SSH-2 channel.
7548 static int ssh2_try_send(struct ssh_channel *c)
7551 struct Packet *pktout;
7554 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7557 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7558 if ((unsigned)len > c->v.v2.remwindow)
7559 len = c->v.v2.remwindow;
7560 if ((unsigned)len > c->v.v2.remmaxpkt)
7561 len = c->v.v2.remmaxpkt;
7562 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7563 ssh2_pkt_adduint32(pktout, c->remoteid);
7564 ssh2_pkt_addstring_start(pktout);
7565 ssh2_pkt_addstring_data(pktout, data, len);
7566 ssh2_pkt_send(ssh, pktout);
7567 bufchain_consume(&c->v.v2.outbuffer, len);
7568 c->v.v2.remwindow -= len;
7572 * After having sent as much data as we can, return the amount
7575 ret = bufchain_size(&c->v.v2.outbuffer);
7578 * And if there's no data pending but we need to send an EOF, send
7581 if (!ret && c->pending_eof)
7582 ssh_channel_try_eof(c);
7587 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7590 if (c->closes & CLOSES_SENT_EOF)
7591 return; /* don't send on channels we've EOFed */
7592 bufsize = ssh2_try_send(c);
7595 case CHAN_MAINSESSION:
7596 /* stdin need not receive an unthrottle
7597 * notification since it will be polled */
7600 x11_unthrottle(c->u.x11.xconn);
7603 /* agent sockets are request/response and need no
7604 * buffer management */
7607 pfd_unthrottle(c->u.pfd.pf);
7613 static int ssh_is_simple(Ssh ssh)
7616 * We use the 'simple' variant of the SSH protocol if we're asked
7617 * to, except not if we're also doing connection-sharing (either
7618 * tunnelling our packets over an upstream or expecting to be
7619 * tunnelled over ourselves), since then the assumption that we
7620 * have only one channel to worry about is not true after all.
7622 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7623 !ssh->bare_connection && !ssh->connshare);
7627 * Set up most of a new ssh_channel for SSH-2.
7629 static void ssh2_channel_init(struct ssh_channel *c)
7632 c->localid = alloc_channel_id(ssh);
7634 c->pending_eof = FALSE;
7635 c->throttling_conn = FALSE;
7636 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7637 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7638 c->v.v2.chanreq_head = NULL;
7639 c->v.v2.throttle_state = UNTHROTTLED;
7640 bufchain_init(&c->v.v2.outbuffer);
7644 * Construct the common parts of a CHANNEL_OPEN.
7646 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c,
7649 struct Packet *pktout;
7651 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7652 ssh2_pkt_addstring(pktout, type);
7653 ssh2_pkt_adduint32(pktout, c->localid);
7654 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7655 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7660 * CHANNEL_FAILURE doesn't come with any indication of what message
7661 * caused it, so we have to keep track of the outstanding
7662 * CHANNEL_REQUESTs ourselves.
7664 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7665 cchandler_fn_t handler, void *ctx)
7667 struct outstanding_channel_request *ocr =
7668 snew(struct outstanding_channel_request);
7670 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7671 ocr->handler = handler;
7674 if (!c->v.v2.chanreq_head)
7675 c->v.v2.chanreq_head = ocr;
7677 c->v.v2.chanreq_tail->next = ocr;
7678 c->v.v2.chanreq_tail = ocr;
7682 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7683 * NULL then a reply will be requested and the handler will be called
7684 * when it arrives. The returned packet is ready to have any
7685 * request-specific data added and be sent. Note that if a handler is
7686 * provided, it's essential that the request actually be sent.
7688 * The handler will usually be passed the response packet in pktin. If
7689 * pktin is NULL, this means that no reply will ever be forthcoming
7690 * (e.g. because the entire connection is being destroyed, or because
7691 * the server initiated channel closure before we saw the response)
7692 * and the handler should free any storage it's holding.
7694 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c,
7696 cchandler_fn_t handler, void *ctx)
7698 struct Packet *pktout;
7700 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7701 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7702 ssh2_pkt_adduint32(pktout, c->remoteid);
7703 ssh2_pkt_addstring(pktout, type);
7704 ssh2_pkt_addbool(pktout, handler != NULL);
7705 if (handler != NULL)
7706 ssh2_queue_chanreq_handler(c, handler, ctx);
7711 * Potentially enlarge the window on an SSH-2 channel.
7713 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7715 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7720 * Never send WINDOW_ADJUST for a channel that the remote side has
7721 * already sent EOF on; there's no point, since it won't be
7722 * sending any more data anyway. Ditto if _we've_ already sent
7725 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7729 * Also, never widen the window for an X11 channel when we're
7730 * still waiting to see its initial auth and may yet hand it off
7733 if (c->type == CHAN_X11 && c->u.x11.initial)
7737 * If the remote end has a habit of ignoring maxpkt, limit the
7738 * window so that it has no choice (assuming it doesn't ignore the
7741 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7742 newwin = OUR_V2_MAXPKT;
7745 * Only send a WINDOW_ADJUST if there's significantly more window
7746 * available than the other end thinks there is. This saves us
7747 * sending a WINDOW_ADJUST for every character in a shell session.
7749 * "Significant" is arbitrarily defined as half the window size.
7751 if (newwin / 2 >= c->v.v2.locwindow) {
7752 struct Packet *pktout;
7756 * In order to keep track of how much window the client
7757 * actually has available, we'd like it to acknowledge each
7758 * WINDOW_ADJUST. We can't do that directly, so we accompany
7759 * it with a CHANNEL_REQUEST that has to be acknowledged.
7761 * This is only necessary if we're opening the window wide.
7762 * If we're not, then throughput is being constrained by
7763 * something other than the maximum window size anyway.
7765 if (newwin == c->v.v2.locmaxwin &&
7766 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7767 up = snew(unsigned);
7768 *up = newwin - c->v.v2.locwindow;
7769 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7770 ssh2_handle_winadj_response, up);
7771 ssh2_pkt_send(ssh, pktout);
7773 if (c->v.v2.throttle_state != UNTHROTTLED)
7774 c->v.v2.throttle_state = UNTHROTTLING;
7776 /* Pretend the WINDOW_ADJUST was acked immediately. */
7777 c->v.v2.remlocwin = newwin;
7778 c->v.v2.throttle_state = THROTTLED;
7780 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7781 ssh2_pkt_adduint32(pktout, c->remoteid);
7782 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7783 ssh2_pkt_send(ssh, pktout);
7784 c->v.v2.locwindow = newwin;
7789 * Find the channel associated with a message. If there's no channel,
7790 * or it's not properly open, make a noise about it and return NULL.
7792 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7794 unsigned localid = ssh_pkt_getuint32(pktin);
7795 struct ssh_channel *c;
7797 c = find234(ssh->channels, &localid, ssh_channelfind);
7799 (c->type != CHAN_SHARING && c->halfopen &&
7800 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7801 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7802 char *buf = dupprintf("Received %s for %s channel %u",
7803 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7805 c ? "half-open" : "nonexistent", localid);
7806 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7813 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7814 struct Packet *pktin, void *ctx)
7816 unsigned *sizep = ctx;
7819 * Winadj responses should always be failures. However, at least
7820 * one server ("boks_sshd") is known to return SUCCESS for channel
7821 * requests it's never heard of, such as "winadj@putty". Raised
7822 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7823 * life, we don't worry about what kind of response we got.
7826 c->v.v2.remlocwin += *sizep;
7829 * winadj messages are only sent when the window is fully open, so
7830 * if we get an ack of one, we know any pending unthrottle is
7833 if (c->v.v2.throttle_state == UNTHROTTLING)
7834 c->v.v2.throttle_state = UNTHROTTLED;
7837 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7839 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7840 struct outstanding_channel_request *ocr;
7843 if (c->type == CHAN_SHARING) {
7844 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7845 pktin->body, pktin->length);
7848 ocr = c->v.v2.chanreq_head;
7850 ssh2_msg_unexpected(ssh, pktin);
7853 ocr->handler(c, pktin, ocr->ctx);
7854 c->v.v2.chanreq_head = ocr->next;
7857 * We may now initiate channel-closing procedures, if that
7858 * CHANNEL_REQUEST was the last thing outstanding before we send
7861 ssh2_channel_check_close(c);
7864 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7866 struct ssh_channel *c;
7867 c = ssh2_channel_msg(ssh, pktin);
7870 if (c->type == CHAN_SHARING) {
7871 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7872 pktin->body, pktin->length);
7875 if (!(c->closes & CLOSES_SENT_EOF)) {
7876 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7877 ssh2_try_send_and_unthrottle(ssh, c);
7881 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7885 struct ssh_channel *c;
7886 c = ssh2_channel_msg(ssh, pktin);
7889 if (c->type == CHAN_SHARING) {
7890 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7891 pktin->body, pktin->length);
7894 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7895 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7896 return; /* extended but not stderr */
7897 ssh_pkt_getstring(pktin, &data, &length);
7900 c->v.v2.locwindow -= length;
7901 c->v.v2.remlocwin -= length;
7903 case CHAN_MAINSESSION:
7905 from_backend(ssh->frontend, pktin->type ==
7906 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7910 bufsize = x11_send(c->u.x11.xconn, data, length);
7913 bufsize = pfd_send(c->u.pfd.pf, data, length);
7916 while (length > 0) {
7917 if (c->u.a.lensofar < 4) {
7918 unsigned int l = min(4 - c->u.a.lensofar,
7920 memcpy(c->u.a.msglen + c->u.a.lensofar,
7924 c->u.a.lensofar += l;
7926 if (c->u.a.lensofar == 4) {
7928 4 + GET_32BIT(c->u.a.msglen);
7929 c->u.a.message = snewn(c->u.a.totallen,
7931 memcpy(c->u.a.message, c->u.a.msglen, 4);
7933 if (c->u.a.lensofar >= 4 && length > 0) {
7935 min(c->u.a.totallen - c->u.a.lensofar,
7937 memcpy(c->u.a.message + c->u.a.lensofar,
7941 c->u.a.lensofar += l;
7943 if (c->u.a.lensofar == c->u.a.totallen) {
7946 c->u.a.outstanding_requests++;
7947 if (agent_query(c->u.a.message,
7950 ssh_agentf_callback, c))
7951 ssh_agentf_callback(c, reply, replylen);
7952 sfree(c->u.a.message);
7953 c->u.a.message = NULL;
7954 c->u.a.lensofar = 0;
7961 * If it looks like the remote end hit the end of its window,
7962 * and we didn't want it to do that, think about using a
7965 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7966 c->v.v2.locmaxwin < 0x40000000)
7967 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7969 * If we are not buffering too much data,
7970 * enlarge the window again at the remote side.
7971 * If we are buffering too much, we may still
7972 * need to adjust the window if the server's
7975 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7976 c->v.v2.locmaxwin - bufsize : 0);
7978 * If we're either buffering way too much data, or if we're
7979 * buffering anything at all and we're in "simple" mode,
7980 * throttle the whole channel.
7982 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7983 && !c->throttling_conn) {
7984 c->throttling_conn = 1;
7985 ssh_throttle_conn(ssh, +1);
7990 static void ssh_check_termination(Ssh ssh)
7992 if (ssh->version == 2 &&
7993 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7994 (ssh->channels && count234(ssh->channels) == 0) &&
7995 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7997 * We used to send SSH_MSG_DISCONNECT here, because I'd
7998 * believed that _every_ conforming SSH-2 connection had to
7999 * end with a disconnect being sent by at least one side;
8000 * apparently I was wrong and it's perfectly OK to
8001 * unceremoniously slam the connection shut when you're done,
8002 * and indeed OpenSSH feels this is more polite than sending a
8003 * DISCONNECT. So now we don't.
8005 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
8009 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id,
8010 const char *peerinfo)
8013 logeventf(ssh, "Connection sharing downstream #%u connected from %s",
8016 logeventf(ssh, "Connection sharing downstream #%u connected", id);
8019 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
8021 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
8022 ssh_check_termination(ssh);
8025 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
8030 va_start(ap, logfmt);
8031 buf = dupvprintf(logfmt, ap);
8034 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
8036 logeventf(ssh, "Connection sharing: %s", buf);
8040 static void ssh_channel_destroy(struct ssh_channel *c)
8045 case CHAN_MAINSESSION:
8046 ssh->mainchan = NULL;
8047 update_specials_menu(ssh->frontend);
8050 if (c->u.x11.xconn != NULL)
8051 x11_close(c->u.x11.xconn);
8052 logevent("Forwarded X11 connection terminated");
8055 sfree(c->u.a.message);
8058 if (c->u.pfd.pf != NULL)
8059 pfd_close(c->u.pfd.pf);
8060 logevent("Forwarded port closed");
8064 del234(ssh->channels, c);
8065 if (ssh->version == 2) {
8066 bufchain_clear(&c->v.v2.outbuffer);
8067 assert(c->v.v2.chanreq_head == NULL);
8072 * If that was the last channel left open, we might need to
8075 ssh_check_termination(ssh);
8078 static void ssh2_channel_check_close(struct ssh_channel *c)
8081 struct Packet *pktout;
8085 * If we've sent out our own CHANNEL_OPEN but not yet seen
8086 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
8087 * it's too early to be sending close messages of any kind.
8092 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
8093 c->type == CHAN_ZOMBIE) &&
8094 !c->v.v2.chanreq_head &&
8095 !(c->closes & CLOSES_SENT_CLOSE)) {
8097 * We have both sent and received EOF (or the channel is a
8098 * zombie), and we have no outstanding channel requests, which
8099 * means the channel is in final wind-up. But we haven't sent
8100 * CLOSE, so let's do so now.
8102 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
8103 ssh2_pkt_adduint32(pktout, c->remoteid);
8104 ssh2_pkt_send(ssh, pktout);
8105 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
8108 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
8109 assert(c->v.v2.chanreq_head == NULL);
8111 * We have both sent and received CLOSE, which means we're
8112 * completely done with the channel.
8114 ssh_channel_destroy(c);
8118 static void ssh2_channel_got_eof(struct ssh_channel *c)
8120 if (c->closes & CLOSES_RCVD_EOF)
8121 return; /* already seen EOF */
8122 c->closes |= CLOSES_RCVD_EOF;
8124 if (c->type == CHAN_X11) {
8125 x11_send_eof(c->u.x11.xconn);
8126 } else if (c->type == CHAN_AGENT) {
8127 if (c->u.a.outstanding_requests == 0) {
8128 /* Manufacture an outgoing EOF in response to the incoming one. */
8129 sshfwd_write_eof(c);
8131 } else if (c->type == CHAN_SOCKDATA) {
8132 pfd_send_eof(c->u.pfd.pf);
8133 } else if (c->type == CHAN_MAINSESSION) {
8136 if (!ssh->sent_console_eof &&
8137 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
8139 * Either from_backend_eof told us that the front end
8140 * wants us to close the outgoing side of the connection
8141 * as soon as we see EOF from the far end, or else we've
8142 * unilaterally decided to do that because we've allocated
8143 * a remote pty and hence EOF isn't a particularly
8144 * meaningful concept.
8146 sshfwd_write_eof(c);
8148 ssh->sent_console_eof = TRUE;
8151 ssh2_channel_check_close(c);
8154 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
8156 struct ssh_channel *c;
8158 c = ssh2_channel_msg(ssh, pktin);
8161 if (c->type == CHAN_SHARING) {
8162 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8163 pktin->body, pktin->length);
8166 ssh2_channel_got_eof(c);
8169 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
8171 struct ssh_channel *c;
8173 c = ssh2_channel_msg(ssh, pktin);
8176 if (c->type == CHAN_SHARING) {
8177 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8178 pktin->body, pktin->length);
8183 * When we receive CLOSE on a channel, we assume it comes with an
8184 * implied EOF if we haven't seen EOF yet.
8186 ssh2_channel_got_eof(c);
8188 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
8190 * It also means we stop expecting to see replies to any
8191 * outstanding channel requests, so clean those up too.
8192 * (ssh_chanreq_init will enforce by assertion that we don't
8193 * subsequently put anything back on this list.)
8195 while (c->v.v2.chanreq_head) {
8196 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
8197 ocr->handler(c, NULL, ocr->ctx);
8198 c->v.v2.chanreq_head = ocr->next;
8204 * And we also send an outgoing EOF, if we haven't already, on the
8205 * assumption that CLOSE is a pretty forceful announcement that
8206 * the remote side is doing away with the entire channel. (If it
8207 * had wanted to send us EOF and continue receiving data from us,
8208 * it would have just sent CHANNEL_EOF.)
8210 if (!(c->closes & CLOSES_SENT_EOF)) {
8212 * Make sure we don't read any more from whatever our local
8213 * data source is for this channel.
8216 case CHAN_MAINSESSION:
8217 ssh->send_ok = 0; /* stop trying to read from stdin */
8220 x11_override_throttle(c->u.x11.xconn, 1);
8223 pfd_override_throttle(c->u.pfd.pf, 1);
8228 * Abandon any buffered data we still wanted to send to this
8229 * channel. Receiving a CHANNEL_CLOSE is an indication that
8230 * the server really wants to get on and _destroy_ this
8231 * channel, and it isn't going to send us any further
8232 * WINDOW_ADJUSTs to permit us to send pending stuff.
8234 bufchain_clear(&c->v.v2.outbuffer);
8237 * Send outgoing EOF.
8239 sshfwd_write_eof(c);
8243 * Now process the actual close.
8245 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
8246 c->closes |= CLOSES_RCVD_CLOSE;
8247 ssh2_channel_check_close(c);
8251 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
8253 struct ssh_channel *c;
8255 c = ssh2_channel_msg(ssh, pktin);
8258 if (c->type == CHAN_SHARING) {
8259 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8260 pktin->body, pktin->length);
8263 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8264 c->remoteid = ssh_pkt_getuint32(pktin);
8265 c->halfopen = FALSE;
8266 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8267 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8269 if (c->type == CHAN_SOCKDATA_DORMANT) {
8270 c->type = CHAN_SOCKDATA;
8272 pfd_confirm(c->u.pfd.pf);
8273 } else if (c->type == CHAN_ZOMBIE) {
8275 * This case can occur if a local socket error occurred
8276 * between us sending out CHANNEL_OPEN and receiving
8277 * OPEN_CONFIRMATION. In this case, all we can do is
8278 * immediately initiate close proceedings now that we know the
8279 * server's id to put in the close message.
8281 ssh2_channel_check_close(c);
8284 * We never expect to receive OPEN_CONFIRMATION for any
8285 * *other* channel type (since only local-to-remote port
8286 * forwardings cause us to send CHANNEL_OPEN after the main
8287 * channel is live - all other auxiliary channel types are
8288 * initiated from the server end). It's safe to enforce this
8289 * by assertion rather than by ssh_disconnect, because the
8290 * real point is that we never constructed a half-open channel
8291 * structure in the first place with any type other than the
8294 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
8298 ssh_channel_try_eof(c); /* in case we had a pending EOF */
8301 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
8303 static const char *const reasons[] = {
8304 "<unknown reason code>",
8305 "Administratively prohibited",
8307 "Unknown channel type",
8308 "Resource shortage",
8310 unsigned reason_code;
8311 char *reason_string;
8313 struct ssh_channel *c;
8315 c = ssh2_channel_msg(ssh, pktin);
8318 if (c->type == CHAN_SHARING) {
8319 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8320 pktin->body, pktin->length);
8323 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
8325 if (c->type == CHAN_SOCKDATA_DORMANT) {
8326 reason_code = ssh_pkt_getuint32(pktin);
8327 if (reason_code >= lenof(reasons))
8328 reason_code = 0; /* ensure reasons[reason_code] in range */
8329 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
8330 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
8331 reasons[reason_code], reason_length,
8332 NULLTOEMPTY(reason_string));
8334 pfd_close(c->u.pfd.pf);
8335 } else if (c->type == CHAN_ZOMBIE) {
8337 * This case can occur if a local socket error occurred
8338 * between us sending out CHANNEL_OPEN and receiving
8339 * OPEN_FAILURE. In this case, we need do nothing except allow
8340 * the code below to throw the half-open channel away.
8344 * We never expect to receive OPEN_FAILURE for any *other*
8345 * channel type (since only local-to-remote port forwardings
8346 * cause us to send CHANNEL_OPEN after the main channel is
8347 * live - all other auxiliary channel types are initiated from
8348 * the server end). It's safe to enforce this by assertion
8349 * rather than by ssh_disconnect, because the real point is
8350 * that we never constructed a half-open channel structure in
8351 * the first place with any type other than the above.
8353 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
8356 del234(ssh->channels, c);
8360 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
8363 int typelen, want_reply;
8364 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
8365 struct ssh_channel *c;
8366 struct Packet *pktout;
8368 c = ssh2_channel_msg(ssh, pktin);
8371 if (c->type == CHAN_SHARING) {
8372 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
8373 pktin->body, pktin->length);
8376 ssh_pkt_getstring(pktin, &type, &typelen);
8377 want_reply = ssh2_pkt_getbool(pktin);
8379 if (c->closes & CLOSES_SENT_CLOSE) {
8381 * We don't reply to channel requests after we've sent
8382 * CHANNEL_CLOSE for the channel, because our reply might
8383 * cross in the network with the other side's CHANNEL_CLOSE
8384 * and arrive after they have wound the channel up completely.
8390 * Having got the channel number, we now look at
8391 * the request type string to see if it's something
8394 if (c == ssh->mainchan) {
8396 * We recognise "exit-status" and "exit-signal" on
8397 * the primary channel.
8399 if (typelen == 11 &&
8400 !memcmp(type, "exit-status", 11)) {
8402 ssh->exitcode = ssh_pkt_getuint32(pktin);
8403 logeventf(ssh, "Server sent command exit status %d",
8405 reply = SSH2_MSG_CHANNEL_SUCCESS;
8407 } else if (typelen == 11 &&
8408 !memcmp(type, "exit-signal", 11)) {
8410 int is_plausible = TRUE, is_int = FALSE;
8411 char *fmt_sig = NULL, *fmt_msg = NULL;
8413 int msglen = 0, core = FALSE;
8414 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
8415 * provide an `int' for the signal, despite its
8416 * having been a `string' in the drafts of RFC 4254 since at
8417 * least 2001. (Fixed in session.c 1.147.) Try to
8418 * infer which we can safely parse it as. */
8420 unsigned char *p = pktin->body +
8422 long len = pktin->length - pktin->savedpos;
8423 unsigned long num = GET_32BIT(p); /* what is it? */
8424 /* If it's 0, it hardly matters; assume string */
8428 int maybe_int = FALSE, maybe_str = FALSE;
8429 #define CHECK_HYPOTHESIS(offset, result) \
8432 int q = toint(offset); \
8433 if (q >= 0 && q+4 <= len) { \
8434 q = toint(q + 4 + GET_32BIT(p+q)); \
8435 if (q >= 0 && q+4 <= len && \
8436 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8441 CHECK_HYPOTHESIS(4+1, maybe_int);
8442 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8443 #undef CHECK_HYPOTHESIS
8444 if (maybe_int && !maybe_str)
8446 else if (!maybe_int && maybe_str)
8449 /* Crikey. Either or neither. Panic. */
8450 is_plausible = FALSE;
8453 ssh->exitcode = 128; /* means `unknown signal' */
8456 /* Old non-standard OpenSSH. */
8457 int signum = ssh_pkt_getuint32(pktin);
8458 fmt_sig = dupprintf(" %d", signum);
8459 ssh->exitcode = 128 + signum;
8461 /* As per RFC 4254. */
8464 ssh_pkt_getstring(pktin, &sig, &siglen);
8465 /* Signal name isn't supposed to be blank, but
8466 * let's cope gracefully if it is. */
8468 fmt_sig = dupprintf(" \"%.*s\"",
8473 * Really hideous method of translating the
8474 * signal description back into a locally
8475 * meaningful number.
8480 #define TRANSLATE_SIGNAL(s) \
8481 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8482 ssh->exitcode = 128 + SIG ## s
8484 TRANSLATE_SIGNAL(ABRT);
8487 TRANSLATE_SIGNAL(ALRM);
8490 TRANSLATE_SIGNAL(FPE);
8493 TRANSLATE_SIGNAL(HUP);
8496 TRANSLATE_SIGNAL(ILL);
8499 TRANSLATE_SIGNAL(INT);
8502 TRANSLATE_SIGNAL(KILL);
8505 TRANSLATE_SIGNAL(PIPE);
8508 TRANSLATE_SIGNAL(QUIT);
8511 TRANSLATE_SIGNAL(SEGV);
8514 TRANSLATE_SIGNAL(TERM);
8517 TRANSLATE_SIGNAL(USR1);
8520 TRANSLATE_SIGNAL(USR2);
8522 #undef TRANSLATE_SIGNAL
8524 ssh->exitcode = 128;
8526 core = ssh2_pkt_getbool(pktin);
8527 ssh_pkt_getstring(pktin, &msg, &msglen);
8529 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8531 /* ignore lang tag */
8532 } /* else don't attempt to parse */
8533 logeventf(ssh, "Server exited on signal%s%s%s",
8534 fmt_sig ? fmt_sig : "",
8535 core ? " (core dumped)" : "",
8536 fmt_msg ? fmt_msg : "");
8539 reply = SSH2_MSG_CHANNEL_SUCCESS;
8544 * This is a channel request we don't know
8545 * about, so we now either ignore the request
8546 * or respond with CHANNEL_FAILURE, depending
8549 reply = SSH2_MSG_CHANNEL_FAILURE;
8552 pktout = ssh2_pkt_init(reply);
8553 ssh2_pkt_adduint32(pktout, c->remoteid);
8554 ssh2_pkt_send(ssh, pktout);
8558 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8561 int typelen, want_reply;
8562 struct Packet *pktout;
8564 ssh_pkt_getstring(pktin, &type, &typelen);
8565 want_reply = ssh2_pkt_getbool(pktin);
8568 * We currently don't support any global requests
8569 * at all, so we either ignore the request or
8570 * respond with REQUEST_FAILURE, depending on
8574 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8575 ssh2_pkt_send(ssh, pktout);
8579 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8583 struct X11FakeAuth *auth;
8586 * Make up a new set of fake X11 auth data, and add it to the tree
8587 * of currently valid ones with an indication of the sharing
8588 * context that it's relevant to.
8590 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8591 auth->share_cs = share_cs;
8592 auth->share_chan = share_chan;
8597 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8599 del234(ssh->x11authtree, auth);
8600 x11_free_fake_auth(auth);
8603 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8610 const char *error = NULL;
8611 struct ssh_channel *c;
8612 unsigned remid, winsize, pktsize;
8613 unsigned our_winsize_override = 0;
8614 struct Packet *pktout;
8616 ssh_pkt_getstring(pktin, &type, &typelen);
8617 c = snew(struct ssh_channel);
8620 remid = ssh_pkt_getuint32(pktin);
8621 winsize = ssh_pkt_getuint32(pktin);
8622 pktsize = ssh_pkt_getuint32(pktin);
8624 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8627 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8628 addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr));
8629 peerport = ssh_pkt_getuint32(pktin);
8631 logeventf(ssh, "Received X11 connect request from %s:%d",
8634 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8635 error = "X11 forwarding is not enabled";
8637 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8640 c->u.x11.initial = TRUE;
8643 * If we are a connection-sharing upstream, then we should
8644 * initially present a very small window, adequate to take
8645 * the X11 initial authorisation packet but not much more.
8646 * Downstream will then present us a larger window (by
8647 * fiat of the connection-sharing protocol) and we can
8648 * guarantee to send a positive-valued WINDOW_ADJUST.
8651 our_winsize_override = 128;
8653 logevent("Opened X11 forward channel");
8657 } else if (typelen == 15 &&
8658 !memcmp(type, "forwarded-tcpip", 15)) {
8659 struct ssh_rportfwd pf, *realpf;
8662 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8663 pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost));
8664 pf.sport = ssh_pkt_getuint32(pktin);
8665 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8666 peerport = ssh_pkt_getuint32(pktin);
8667 realpf = find234(ssh->rportfwds, &pf, NULL);
8668 logeventf(ssh, "Received remote port %s:%d open request "
8669 "from %.*s:%d", pf.shost, pf.sport,
8670 peeraddrlen, NULLTOEMPTY(peeraddr), peerport);
8673 if (realpf == NULL) {
8674 error = "Remote port is not recognised";
8678 if (realpf->share_ctx) {
8680 * This port forwarding is on behalf of a
8681 * connection-sharing downstream, so abandon our own
8682 * channel-open procedure and just pass the message on
8685 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8686 pktin->body, pktin->length);
8691 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8692 c, ssh->conf, realpf->pfrec->addressfamily);
8693 logeventf(ssh, "Attempting to forward remote port to "
8694 "%s:%d", realpf->dhost, realpf->dport);
8696 logeventf(ssh, "Port open failed: %s", err);
8698 error = "Port open failed";
8700 logevent("Forwarded port opened successfully");
8701 c->type = CHAN_SOCKDATA;
8704 } else if (typelen == 22 &&
8705 !memcmp(type, "auth-agent@openssh.com", 22)) {
8706 if (!ssh->agentfwd_enabled)
8707 error = "Agent forwarding is not enabled";
8709 c->type = CHAN_AGENT; /* identify channel type */
8710 c->u.a.lensofar = 0;
8711 c->u.a.message = NULL;
8712 c->u.a.outstanding_requests = 0;
8715 error = "Unsupported channel type requested";
8718 c->remoteid = remid;
8719 c->halfopen = FALSE;
8721 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8722 ssh2_pkt_adduint32(pktout, c->remoteid);
8723 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8724 ssh2_pkt_addstring(pktout, error);
8725 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8726 ssh2_pkt_send(ssh, pktout);
8727 logeventf(ssh, "Rejected channel open: %s", error);
8730 ssh2_channel_init(c);
8731 c->v.v2.remwindow = winsize;
8732 c->v.v2.remmaxpkt = pktsize;
8733 if (our_winsize_override) {
8734 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8735 our_winsize_override;
8737 add234(ssh->channels, c);
8738 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8739 ssh2_pkt_adduint32(pktout, c->remoteid);
8740 ssh2_pkt_adduint32(pktout, c->localid);
8741 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8742 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8743 ssh2_pkt_send(ssh, pktout);
8747 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8748 void *share_cs, void *share_chan,
8749 const char *peer_addr, int peer_port,
8750 int endian, int protomajor, int protominor,
8751 const void *initial_data, int initial_len)
8754 * This function is called when we've just discovered that an X
8755 * forwarding channel on which we'd been handling the initial auth
8756 * ourselves turns out to be destined for a connection-sharing
8757 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8758 * that we completely stop tracking windows and buffering data and
8759 * just pass more or less unmodified SSH messages back and forth.
8761 c->type = CHAN_SHARING;
8762 c->u.sharing.ctx = share_cs;
8763 share_setup_x11_channel(share_cs, share_chan,
8764 c->localid, c->remoteid, c->v.v2.remwindow,
8765 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8766 peer_addr, peer_port, endian,
8767 protomajor, protominor,
8768 initial_data, initial_len);
8771 void sshfwd_x11_is_local(struct ssh_channel *c)
8774 * This function is called when we've just discovered that an X
8775 * forwarding channel is _not_ destined for a connection-sharing
8776 * downstream but we're going to handle it ourselves. We stop
8777 * presenting a cautiously small window and go into ordinary data
8780 c->u.x11.initial = FALSE;
8781 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8785 * Buffer banner messages for later display at some convenient point,
8786 * if we're going to display them.
8788 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8790 /* Arbitrary limit to prevent unbounded inflation of buffer */
8791 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8792 bufchain_size(&ssh->banner) <= 131072) {
8793 char *banner = NULL;
8795 ssh_pkt_getstring(pktin, &banner, &size);
8797 bufchain_add(&ssh->banner, banner, size);
8801 /* Helper function to deal with sending tty modes for "pty-req" */
8802 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8804 struct Packet *pktout = (struct Packet *)data;
8806 unsigned int arg = 0;
8807 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8808 if (i == lenof(ssh_ttymodes)) return;
8809 switch (ssh_ttymodes[i].type) {
8811 arg = ssh_tty_parse_specchar(val);
8814 arg = ssh_tty_parse_boolean(val);
8817 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8818 ssh2_pkt_adduint32(pktout, arg);
8821 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8824 struct ssh2_setup_x11_state {
8828 struct Packet *pktout;
8829 crStateP(ssh2_setup_x11_state, ctx);
8833 logevent("Requesting X11 forwarding");
8834 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8836 ssh2_pkt_addbool(pktout, 0); /* many connections */
8837 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8838 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8839 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8840 ssh2_pkt_send(ssh, pktout);
8842 /* Wait to be called back with either a response packet, or NULL
8843 * meaning clean up and free our data */
8847 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8848 logevent("X11 forwarding enabled");
8849 ssh->X11_fwd_enabled = TRUE;
8851 logevent("X11 forwarding refused");
8857 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8860 struct ssh2_setup_agent_state {
8864 struct Packet *pktout;
8865 crStateP(ssh2_setup_agent_state, ctx);
8869 logevent("Requesting OpenSSH-style agent forwarding");
8870 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8871 ssh2_setup_agent, s);
8872 ssh2_pkt_send(ssh, pktout);
8874 /* Wait to be called back with either a response packet, or NULL
8875 * meaning clean up and free our data */
8879 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8880 logevent("Agent forwarding enabled");
8881 ssh->agentfwd_enabled = TRUE;
8883 logevent("Agent forwarding refused");
8889 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8892 struct ssh2_setup_pty_state {
8896 struct Packet *pktout;
8897 crStateP(ssh2_setup_pty_state, ctx);
8901 /* Unpick the terminal-speed string. */
8902 /* XXX perhaps we should allow no speeds to be sent. */
8903 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8904 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8905 /* Build the pty request. */
8906 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8908 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8909 ssh2_pkt_adduint32(pktout, ssh->term_width);
8910 ssh2_pkt_adduint32(pktout, ssh->term_height);
8911 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8912 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8913 ssh2_pkt_addstring_start(pktout);
8914 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8915 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8916 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8917 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8918 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8919 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8920 ssh2_pkt_send(ssh, pktout);
8921 ssh->state = SSH_STATE_INTERMED;
8923 /* Wait to be called back with either a response packet, or NULL
8924 * meaning clean up and free our data */
8928 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8929 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8930 ssh->ospeed, ssh->ispeed);
8931 ssh->got_pty = TRUE;
8933 c_write_str(ssh, "Server refused to allocate pty\r\n");
8934 ssh->editing = ssh->echoing = 1;
8941 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8944 struct ssh2_setup_env_state {
8946 int num_env, env_left, env_ok;
8949 struct Packet *pktout;
8950 crStateP(ssh2_setup_env_state, ctx);
8955 * Send environment variables.
8957 * Simplest thing here is to send all the requests at once, and
8958 * then wait for a whole bunch of successes or failures.
8964 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8966 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8967 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8968 ssh2_pkt_addstring(pktout, key);
8969 ssh2_pkt_addstring(pktout, val);
8970 ssh2_pkt_send(ssh, pktout);
8975 logeventf(ssh, "Sent %d environment variables", s->num_env);
8980 s->env_left = s->num_env;
8982 while (s->env_left > 0) {
8983 /* Wait to be called back with either a response packet,
8984 * or NULL meaning clean up and free our data */
8986 if (!pktin) goto out;
8987 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8992 if (s->env_ok == s->num_env) {
8993 logevent("All environment variables successfully set");
8994 } else if (s->env_ok == 0) {
8995 logevent("All environment variables refused");
8996 c_write_str(ssh, "Server refused to set environment variables\r\n");
8998 logeventf(ssh, "%d environment variables refused",
8999 s->num_env - s->env_ok);
9000 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9008 * Handle the SSH-2 userauth and connection layers.
9010 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
9012 do_ssh2_authconn(ssh, NULL, 0, pktin);
9015 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
9019 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
9022 static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen,
9023 struct Packet *pktin)
9025 struct do_ssh2_authconn_state {
9029 AUTH_TYPE_PUBLICKEY,
9030 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
9031 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
9033 AUTH_TYPE_GSSAPI, /* always QUIET */
9034 AUTH_TYPE_KEYBOARD_INTERACTIVE,
9035 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
9037 int done_service_req;
9038 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
9039 int tried_pubkey_config, done_agent;
9044 int kbd_inter_refused;
9045 int we_are_in, userauth_success;
9046 prompts_t *cur_prompt;
9051 void *publickey_blob;
9052 int publickey_bloblen;
9053 int privatekey_available, privatekey_encrypted;
9054 char *publickey_algorithm;
9055 char *publickey_comment;
9056 unsigned char agent_request[5], *agent_response, *agentp;
9057 int agent_responselen;
9058 unsigned char *pkblob_in_agent;
9060 char *pkblob, *alg, *commentp;
9061 int pklen, alglen, commentlen;
9062 int siglen, retlen, len;
9063 char *q, *agentreq, *ret;
9065 struct Packet *pktout;
9068 struct ssh_gss_library *gsslib;
9069 Ssh_gss_ctx gss_ctx;
9070 Ssh_gss_buf gss_buf;
9071 Ssh_gss_buf gss_rcvtok, gss_sndtok;
9072 Ssh_gss_name gss_srv_name;
9073 Ssh_gss_stat gss_stat;
9076 crState(do_ssh2_authconn_state);
9080 /* Register as a handler for all the messages this coroutine handles. */
9081 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
9082 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
9083 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
9084 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
9085 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
9086 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
9087 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
9088 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
9089 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
9090 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
9091 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
9092 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
9093 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
9094 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
9095 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
9096 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
9097 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
9098 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
9099 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
9100 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
9102 s->done_service_req = FALSE;
9103 s->we_are_in = s->userauth_success = FALSE;
9104 s->agent_response = NULL;
9106 s->tried_gssapi = FALSE;
9109 if (!ssh->bare_connection) {
9110 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
9112 * Request userauth protocol, and await a response to it.
9114 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9115 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
9116 ssh2_pkt_send(ssh, s->pktout);
9117 crWaitUntilV(pktin);
9118 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
9119 s->done_service_req = TRUE;
9121 if (!s->done_service_req) {
9123 * Request connection protocol directly, without authentication.
9125 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
9126 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9127 ssh2_pkt_send(ssh, s->pktout);
9128 crWaitUntilV(pktin);
9129 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
9130 s->we_are_in = TRUE; /* no auth required */
9132 bombout(("Server refused service request"));
9137 s->we_are_in = TRUE;
9140 /* Arrange to be able to deal with any BANNERs that come in.
9141 * (We do this now as packets may come in during the next bit.) */
9142 bufchain_init(&ssh->banner);
9143 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
9144 ssh2_msg_userauth_banner;
9147 * Misc one-time setup for authentication.
9149 s->publickey_blob = NULL;
9150 if (!s->we_are_in) {
9153 * Load the public half of any configured public key file
9156 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9157 if (!filename_is_null(s->keyfile)) {
9159 logeventf(ssh, "Reading key file \"%.150s\"",
9160 filename_to_str(s->keyfile));
9161 keytype = key_type(s->keyfile);
9162 if (keytype == SSH_KEYTYPE_SSH2 ||
9163 keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 ||
9164 keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
9167 ssh2_userkey_loadpub(s->keyfile,
9168 &s->publickey_algorithm,
9169 &s->publickey_bloblen,
9170 &s->publickey_comment, &error);
9171 if (s->publickey_blob) {
9172 s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2);
9173 if (!s->privatekey_available)
9174 logeventf(ssh, "Key file contains public key only");
9175 s->privatekey_encrypted =
9176 ssh2_userkey_encrypted(s->keyfile, NULL);
9179 logeventf(ssh, "Unable to load key (%s)",
9181 msgbuf = dupprintf("Unable to load key file "
9182 "\"%.150s\" (%s)\r\n",
9183 filename_to_str(s->keyfile),
9185 c_write_str(ssh, msgbuf);
9190 logeventf(ssh, "Unable to use this key file (%s)",
9191 key_type_to_str(keytype));
9192 msgbuf = dupprintf("Unable to use key file \"%.150s\""
9194 filename_to_str(s->keyfile),
9195 key_type_to_str(keytype));
9196 c_write_str(ssh, msgbuf);
9198 s->publickey_blob = NULL;
9203 * Find out about any keys Pageant has (but if there's a
9204 * public key configured, filter out all others).
9207 s->agent_response = NULL;
9208 s->pkblob_in_agent = NULL;
9209 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
9213 logevent("Pageant is running. Requesting keys.");
9215 /* Request the keys held by the agent. */
9216 PUT_32BIT(s->agent_request, 1);
9217 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
9218 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
9219 ssh_agent_callback, ssh)) {
9223 bombout(("Unexpected data from server while"
9224 " waiting for agent response"));
9227 } while (pktin || inlen > 0);
9228 r = ssh->agent_response;
9229 s->agent_responselen = ssh->agent_response_len;
9231 s->agent_response = (unsigned char *) r;
9232 if (s->agent_response && s->agent_responselen >= 5 &&
9233 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
9236 p = s->agent_response + 5;
9237 s->nkeys = toint(GET_32BIT(p));
9240 * Vet the Pageant response to ensure that the key
9241 * count and blob lengths make sense.
9244 logeventf(ssh, "Pageant response contained a negative"
9245 " key count %d", s->nkeys);
9247 goto done_agent_query;
9249 unsigned char *q = p + 4;
9250 int lenleft = s->agent_responselen - 5 - 4;
9252 for (keyi = 0; keyi < s->nkeys; keyi++) {
9253 int bloblen, commentlen;
9255 logeventf(ssh, "Pageant response was truncated");
9257 goto done_agent_query;
9259 bloblen = toint(GET_32BIT(q));
9260 if (bloblen < 0 || bloblen > lenleft) {
9261 logeventf(ssh, "Pageant response was truncated");
9263 goto done_agent_query;
9265 lenleft -= 4 + bloblen;
9267 commentlen = toint(GET_32BIT(q));
9268 if (commentlen < 0 || commentlen > lenleft) {
9269 logeventf(ssh, "Pageant response was truncated");
9271 goto done_agent_query;
9273 lenleft -= 4 + commentlen;
9274 q += 4 + commentlen;
9279 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
9280 if (s->publickey_blob) {
9281 /* See if configured key is in agent. */
9282 for (keyi = 0; keyi < s->nkeys; keyi++) {
9283 s->pklen = toint(GET_32BIT(p));
9284 if (s->pklen == s->publickey_bloblen &&
9285 !memcmp(p+4, s->publickey_blob,
9286 s->publickey_bloblen)) {
9287 logeventf(ssh, "Pageant key #%d matches "
9288 "configured key file", keyi);
9290 s->pkblob_in_agent = p;
9294 p += toint(GET_32BIT(p)) + 4; /* comment */
9296 if (!s->pkblob_in_agent) {
9297 logevent("Configured key file not in Pageant");
9302 logevent("Failed to get reply from Pageant");
9310 * We repeat this whole loop, including the username prompt,
9311 * until we manage a successful authentication. If the user
9312 * types the wrong _password_, they can be sent back to the
9313 * beginning to try another username, if this is configured on.
9314 * (If they specify a username in the config, they are never
9315 * asked, even if they do give a wrong password.)
9317 * I think this best serves the needs of
9319 * - the people who have no configuration, no keys, and just
9320 * want to try repeated (username,password) pairs until they
9321 * type both correctly
9323 * - people who have keys and configuration but occasionally
9324 * need to fall back to passwords
9326 * - people with a key held in Pageant, who might not have
9327 * logged in to a particular machine before; so they want to
9328 * type a username, and then _either_ their key will be
9329 * accepted, _or_ they will type a password. If they mistype
9330 * the username they will want to be able to get back and
9333 s->got_username = FALSE;
9334 while (!s->we_are_in) {
9338 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
9340 * We got a username last time round this loop, and
9341 * with change_username turned off we don't try to get
9344 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
9345 int ret; /* need not be kept over crReturn */
9346 s->cur_prompt = new_prompts(ssh->frontend);
9347 s->cur_prompt->to_server = TRUE;
9348 s->cur_prompt->name = dupstr("SSH login name");
9349 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
9350 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9353 crWaitUntilV(!pktin);
9354 ret = get_userpass_input(s->cur_prompt, in, inlen);
9359 * get_userpass_input() failed to get a username.
9362 free_prompts(s->cur_prompt);
9363 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
9366 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
9367 free_prompts(s->cur_prompt);
9370 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
9371 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
9372 c_write_str(ssh, stuff);
9376 s->got_username = TRUE;
9379 * Send an authentication request using method "none": (a)
9380 * just in case it succeeds, and (b) so that we know what
9381 * authentication methods we can usefully try next.
9383 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9385 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9386 ssh2_pkt_addstring(s->pktout, ssh->username);
9387 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
9388 ssh2_pkt_addstring(s->pktout, "none"); /* method */
9389 ssh2_pkt_send(ssh, s->pktout);
9390 s->type = AUTH_TYPE_NONE;
9392 s->we_are_in = FALSE;
9394 s->tried_pubkey_config = FALSE;
9395 s->kbd_inter_refused = FALSE;
9397 /* Reset agent request state. */
9398 s->done_agent = FALSE;
9399 if (s->agent_response) {
9400 if (s->pkblob_in_agent) {
9401 s->agentp = s->pkblob_in_agent;
9403 s->agentp = s->agent_response + 5 + 4;
9409 char *methods = NULL;
9413 * Wait for the result of the last authentication request.
9416 crWaitUntilV(pktin);
9418 * Now is a convenient point to spew any banner material
9419 * that we've accumulated. (This should ensure that when
9420 * we exit the auth loop, we haven't any left to deal
9424 int size = bufchain_size(&ssh->banner);
9426 * Don't show the banner if we're operating in
9427 * non-verbose non-interactive mode. (It's probably
9428 * a script, which means nobody will read the
9429 * banner _anyway_, and moreover the printing of
9430 * the banner will screw up processing on the
9431 * output of (say) plink.)
9433 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
9434 char *banner = snewn(size, char);
9435 bufchain_fetch(&ssh->banner, banner, size);
9436 c_write_untrusted(ssh, banner, size);
9439 bufchain_clear(&ssh->banner);
9441 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9442 logevent("Access granted");
9443 s->we_are_in = s->userauth_success = TRUE;
9447 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9448 bombout(("Strange packet received during authentication: "
9449 "type %d", pktin->type));
9456 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9457 * we can look at the string in it and know what we can
9458 * helpfully try next.
9460 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9461 ssh_pkt_getstring(pktin, &methods, &methlen);
9462 if (!ssh2_pkt_getbool(pktin)) {
9464 * We have received an unequivocal Access
9465 * Denied. This can translate to a variety of
9466 * messages, or no message at all.
9468 * For forms of authentication which are attempted
9469 * implicitly, by which I mean without printing
9470 * anything in the window indicating that we're
9471 * trying them, we should never print 'Access
9474 * If we do print a message saying that we're
9475 * attempting some kind of authentication, it's OK
9476 * to print a followup message saying it failed -
9477 * but the message may sometimes be more specific
9478 * than simply 'Access denied'.
9480 * Additionally, if we'd just tried password
9481 * authentication, we should break out of this
9482 * whole loop so as to go back to the username
9483 * prompt (iff we're configured to allow
9484 * username change attempts).
9486 if (s->type == AUTH_TYPE_NONE) {
9488 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9489 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9490 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9491 c_write_str(ssh, "Server refused our key\r\n");
9492 logevent("Server refused our key");
9493 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9494 /* This _shouldn't_ happen except by a
9495 * protocol bug causing client and server to
9496 * disagree on what is a correct signature. */
9497 c_write_str(ssh, "Server refused public-key signature"
9498 " despite accepting key!\r\n");
9499 logevent("Server refused public-key signature"
9500 " despite accepting key!");
9501 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9502 /* quiet, so no c_write */
9503 logevent("Server refused keyboard-interactive authentication");
9504 } else if (s->type==AUTH_TYPE_GSSAPI) {
9505 /* always quiet, so no c_write */
9506 /* also, the code down in the GSSAPI block has
9507 * already logged this in the Event Log */
9508 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9509 logevent("Keyboard-interactive authentication failed");
9510 c_write_str(ssh, "Access denied\r\n");
9512 assert(s->type == AUTH_TYPE_PASSWORD);
9513 logevent("Password authentication failed");
9514 c_write_str(ssh, "Access denied\r\n");
9516 if (conf_get_int(ssh->conf, CONF_change_username)) {
9517 /* XXX perhaps we should allow
9518 * keyboard-interactive to do this too? */
9519 s->we_are_in = FALSE;
9524 c_write_str(ssh, "Further authentication required\r\n");
9525 logevent("Further authentication required");
9529 in_commasep_string("publickey", methods, methlen);
9531 in_commasep_string("password", methods, methlen);
9532 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9533 in_commasep_string("keyboard-interactive", methods, methlen);
9535 if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9536 in_commasep_string("gssapi-with-mic", methods, methlen)) {
9537 /* Try loading the GSS libraries and see if we
9540 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9541 s->can_gssapi = (ssh->gsslibs->nlibraries > 0);
9543 /* No point in even bothering to try to load the
9544 * GSS libraries, if the user configuration and
9545 * server aren't both prepared to attempt GSSAPI
9546 * auth in the first place. */
9547 s->can_gssapi = FALSE;
9552 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9554 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9557 * Attempt public-key authentication using a key from Pageant.
9560 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9562 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9564 /* Unpack key from agent response */
9565 s->pklen = toint(GET_32BIT(s->agentp));
9567 s->pkblob = (char *)s->agentp;
9568 s->agentp += s->pklen;
9569 s->alglen = toint(GET_32BIT(s->pkblob));
9570 s->alg = s->pkblob + 4;
9571 s->commentlen = toint(GET_32BIT(s->agentp));
9573 s->commentp = (char *)s->agentp;
9574 s->agentp += s->commentlen;
9575 /* s->agentp now points at next key, if any */
9577 /* See if server will accept it */
9578 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9579 ssh2_pkt_addstring(s->pktout, ssh->username);
9580 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9581 /* service requested */
9582 ssh2_pkt_addstring(s->pktout, "publickey");
9584 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9585 ssh2_pkt_addstring_start(s->pktout);
9586 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9587 ssh2_pkt_addstring_start(s->pktout);
9588 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9589 ssh2_pkt_send(ssh, s->pktout);
9590 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9592 crWaitUntilV(pktin);
9593 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9595 /* Offer of key refused. */
9602 if (flags & FLAG_VERBOSE) {
9603 c_write_str(ssh, "Authenticating with "
9605 c_write(ssh, s->commentp, s->commentlen);
9606 c_write_str(ssh, "\" from agent\r\n");
9610 * Server is willing to accept the key.
9611 * Construct a SIGN_REQUEST.
9613 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9614 ssh2_pkt_addstring(s->pktout, ssh->username);
9615 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9616 /* service requested */
9617 ssh2_pkt_addstring(s->pktout, "publickey");
9619 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9620 ssh2_pkt_addstring_start(s->pktout);
9621 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9622 ssh2_pkt_addstring_start(s->pktout);
9623 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9625 /* Ask agent for signature. */
9626 s->siglen = s->pktout->length - 5 + 4 +
9627 ssh->v2_session_id_len;
9628 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9630 s->len = 1; /* message type */
9631 s->len += 4 + s->pklen; /* key blob */
9632 s->len += 4 + s->siglen; /* data to sign */
9633 s->len += 4; /* flags */
9634 s->agentreq = snewn(4 + s->len, char);
9635 PUT_32BIT(s->agentreq, s->len);
9636 s->q = s->agentreq + 4;
9637 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9638 PUT_32BIT(s->q, s->pklen);
9640 memcpy(s->q, s->pkblob, s->pklen);
9642 PUT_32BIT(s->q, s->siglen);
9644 /* Now the data to be signed... */
9645 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9646 PUT_32BIT(s->q, ssh->v2_session_id_len);
9649 memcpy(s->q, ssh->v2_session_id,
9650 ssh->v2_session_id_len);
9651 s->q += ssh->v2_session_id_len;
9652 memcpy(s->q, s->pktout->data + 5,
9653 s->pktout->length - 5);
9654 s->q += s->pktout->length - 5;
9655 /* And finally the (zero) flags word. */
9657 if (!agent_query(s->agentreq, s->len + 4,
9659 ssh_agent_callback, ssh)) {
9663 bombout(("Unexpected data from server"
9664 " while waiting for agent"
9668 } while (pktin || inlen > 0);
9669 vret = ssh->agent_response;
9670 s->retlen = ssh->agent_response_len;
9675 if (s->retlen >= 9 &&
9676 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9677 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9678 logevent("Sending Pageant's response");
9679 ssh2_add_sigblob(ssh, s->pktout,
9680 s->pkblob, s->pklen,
9682 GET_32BIT(s->ret + 5));
9683 ssh2_pkt_send(ssh, s->pktout);
9684 s->type = AUTH_TYPE_PUBLICKEY;
9686 /* FIXME: less drastic response */
9687 bombout(("Pageant failed to answer challenge"));
9693 /* Do we have any keys left to try? */
9694 if (s->pkblob_in_agent) {
9695 s->done_agent = TRUE;
9696 s->tried_pubkey_config = TRUE;
9699 if (s->keyi >= s->nkeys)
9700 s->done_agent = TRUE;
9703 } else if (s->can_pubkey && s->publickey_blob &&
9704 s->privatekey_available && !s->tried_pubkey_config) {
9706 struct ssh2_userkey *key; /* not live over crReturn */
9707 char *passphrase; /* not live over crReturn */
9709 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9711 s->tried_pubkey_config = TRUE;
9714 * Try the public key supplied in the configuration.
9716 * First, offer the public blob to see if the server is
9717 * willing to accept it.
9719 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9720 ssh2_pkt_addstring(s->pktout, ssh->username);
9721 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9722 /* service requested */
9723 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9724 ssh2_pkt_addbool(s->pktout, FALSE);
9725 /* no signature included */
9726 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9727 ssh2_pkt_addstring_start(s->pktout);
9728 ssh2_pkt_addstring_data(s->pktout,
9729 (char *)s->publickey_blob,
9730 s->publickey_bloblen);
9731 ssh2_pkt_send(ssh, s->pktout);
9732 logevent("Offered public key");
9734 crWaitUntilV(pktin);
9735 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9736 /* Key refused. Give up. */
9737 s->gotit = TRUE; /* reconsider message next loop */
9738 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9739 continue; /* process this new message */
9741 logevent("Offer of public key accepted");
9744 * Actually attempt a serious authentication using
9747 if (flags & FLAG_VERBOSE) {
9748 c_write_str(ssh, "Authenticating with public key \"");
9749 c_write_str(ssh, s->publickey_comment);
9750 c_write_str(ssh, "\"\r\n");
9754 const char *error; /* not live over crReturn */
9755 if (s->privatekey_encrypted) {
9757 * Get a passphrase from the user.
9759 int ret; /* need not be kept over crReturn */
9760 s->cur_prompt = new_prompts(ssh->frontend);
9761 s->cur_prompt->to_server = FALSE;
9762 s->cur_prompt->name = dupstr("SSH key passphrase");
9763 add_prompt(s->cur_prompt,
9764 dupprintf("Passphrase for key \"%.100s\": ",
9765 s->publickey_comment),
9767 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9770 crWaitUntilV(!pktin);
9771 ret = get_userpass_input(s->cur_prompt,
9776 /* Failed to get a passphrase. Terminate. */
9777 free_prompts(s->cur_prompt);
9778 ssh_disconnect(ssh, NULL,
9779 "Unable to authenticate",
9780 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9785 dupstr(s->cur_prompt->prompts[0]->result);
9786 free_prompts(s->cur_prompt);
9788 passphrase = NULL; /* no passphrase needed */
9792 * Try decrypting the key.
9794 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9795 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9797 /* burn the evidence */
9798 smemclr(passphrase, strlen(passphrase));
9801 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9803 (key == SSH2_WRONG_PASSPHRASE)) {
9804 c_write_str(ssh, "Wrong passphrase\r\n");
9806 /* and loop again */
9808 c_write_str(ssh, "Unable to load private key (");
9809 c_write_str(ssh, error);
9810 c_write_str(ssh, ")\r\n");
9812 break; /* try something else */
9818 unsigned char *pkblob, *sigblob, *sigdata;
9819 int pkblob_len, sigblob_len, sigdata_len;
9823 * We have loaded the private key and the server
9824 * has announced that it's willing to accept it.
9825 * Hallelujah. Generate a signature and send it.
9827 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9828 ssh2_pkt_addstring(s->pktout, ssh->username);
9829 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9830 /* service requested */
9831 ssh2_pkt_addstring(s->pktout, "publickey");
9833 ssh2_pkt_addbool(s->pktout, TRUE);
9834 /* signature follows */
9835 ssh2_pkt_addstring(s->pktout, key->alg->name);
9836 pkblob = key->alg->public_blob(key->data,
9838 ssh2_pkt_addstring_start(s->pktout);
9839 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9843 * The data to be signed is:
9847 * followed by everything so far placed in the
9850 sigdata_len = s->pktout->length - 5 + 4 +
9851 ssh->v2_session_id_len;
9852 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9854 sigdata = snewn(sigdata_len, unsigned char);
9856 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9857 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9860 memcpy(sigdata+p, ssh->v2_session_id,
9861 ssh->v2_session_id_len);
9862 p += ssh->v2_session_id_len;
9863 memcpy(sigdata+p, s->pktout->data + 5,
9864 s->pktout->length - 5);
9865 p += s->pktout->length - 5;
9866 assert(p == sigdata_len);
9867 sigblob = key->alg->sign(key->data, (char *)sigdata,
9868 sigdata_len, &sigblob_len);
9869 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9870 sigblob, sigblob_len);
9875 ssh2_pkt_send(ssh, s->pktout);
9876 logevent("Sent public key signature");
9877 s->type = AUTH_TYPE_PUBLICKEY;
9878 key->alg->freekey(key->data);
9879 sfree(key->comment);
9884 } else if (s->can_gssapi && !s->tried_gssapi) {
9886 /* GSSAPI Authentication */
9891 s->type = AUTH_TYPE_GSSAPI;
9892 s->tried_gssapi = TRUE;
9894 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9897 * Pick the highest GSS library on the preference
9903 for (i = 0; i < ngsslibs; i++) {
9904 int want_id = conf_get_int_int(ssh->conf,
9905 CONF_ssh_gsslist, i);
9906 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9907 if (ssh->gsslibs->libraries[j].id == want_id) {
9908 s->gsslib = &ssh->gsslibs->libraries[j];
9909 goto got_gsslib; /* double break */
9914 * We always expect to have found something in
9915 * the above loop: we only came here if there
9916 * was at least one viable GSS library, and the
9917 * preference list should always mention
9918 * everything and only change the order.
9923 if (s->gsslib->gsslogmsg)
9924 logevent(s->gsslib->gsslogmsg);
9926 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9927 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9928 ssh2_pkt_addstring(s->pktout, ssh->username);
9929 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9930 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9931 logevent("Attempting GSSAPI authentication");
9933 /* add mechanism info */
9934 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9936 /* number of GSSAPI mechanisms */
9937 ssh2_pkt_adduint32(s->pktout,1);
9939 /* length of OID + 2 */
9940 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9941 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9944 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9946 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9948 ssh2_pkt_send(ssh, s->pktout);
9949 crWaitUntilV(pktin);
9950 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9951 logevent("GSSAPI authentication request refused");
9955 /* check returned packet ... */
9957 ssh_pkt_getstring(pktin, &data, &len);
9958 s->gss_rcvtok.value = data;
9959 s->gss_rcvtok.length = len;
9960 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9961 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9962 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9963 memcmp((char *)s->gss_rcvtok.value + 2,
9964 s->gss_buf.value,s->gss_buf.length) ) {
9965 logevent("GSSAPI authentication - wrong response from server");
9969 /* now start running */
9970 s->gss_stat = s->gsslib->import_name(s->gsslib,
9973 if (s->gss_stat != SSH_GSS_OK) {
9974 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9975 logevent("GSSAPI import name failed - Bad service name");
9977 logevent("GSSAPI import name failed");
9981 /* fetch TGT into GSS engine */
9982 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9984 if (s->gss_stat != SSH_GSS_OK) {
9985 logevent("GSSAPI authentication failed to get credentials");
9986 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9990 /* initial tokens are empty */
9991 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9992 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9994 /* now enter the loop */
9996 s->gss_stat = s->gsslib->init_sec_context
10000 conf_get_int(ssh->conf, CONF_gssapifwd),
10004 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
10005 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
10006 logevent("GSSAPI authentication initialisation failed");
10008 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
10009 &s->gss_buf) == SSH_GSS_OK) {
10010 logevent(s->gss_buf.value);
10011 sfree(s->gss_buf.value);
10016 logevent("GSSAPI authentication initialised");
10018 /* Client and server now exchange tokens until GSSAPI
10019 * no longer says CONTINUE_NEEDED */
10021 if (s->gss_sndtok.length != 0) {
10022 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
10023 ssh_pkt_addstring_start(s->pktout);
10024 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
10025 ssh2_pkt_send(ssh, s->pktout);
10026 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
10029 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
10030 crWaitUntilV(pktin);
10031 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
10032 logevent("GSSAPI authentication - bad server response");
10033 s->gss_stat = SSH_GSS_FAILURE;
10036 ssh_pkt_getstring(pktin, &data, &len);
10037 s->gss_rcvtok.value = data;
10038 s->gss_rcvtok.length = len;
10040 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
10042 if (s->gss_stat != SSH_GSS_OK) {
10043 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10044 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10047 logevent("GSSAPI authentication loop finished OK");
10049 /* Now send the MIC */
10051 s->pktout = ssh2_pkt_init(0);
10052 micoffset = s->pktout->length;
10053 ssh_pkt_addstring_start(s->pktout);
10054 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
10055 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
10056 ssh_pkt_addstring(s->pktout, ssh->username);
10057 ssh_pkt_addstring(s->pktout, "ssh-connection");
10058 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
10060 s->gss_buf.value = (char *)s->pktout->data + micoffset;
10061 s->gss_buf.length = s->pktout->length - micoffset;
10063 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
10064 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
10065 ssh_pkt_addstring_start(s->pktout);
10066 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
10067 ssh2_pkt_send(ssh, s->pktout);
10068 s->gsslib->free_mic(s->gsslib, &mic);
10072 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
10073 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
10076 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
10079 * Keyboard-interactive authentication.
10082 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
10084 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
10086 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10087 ssh2_pkt_addstring(s->pktout, ssh->username);
10088 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10089 /* service requested */
10090 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
10092 ssh2_pkt_addstring(s->pktout, ""); /* lang */
10093 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
10094 ssh2_pkt_send(ssh, s->pktout);
10096 logevent("Attempting keyboard-interactive authentication");
10098 crWaitUntilV(pktin);
10099 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
10100 /* Server is not willing to do keyboard-interactive
10101 * at all (or, bizarrely but legally, accepts the
10102 * user without actually issuing any prompts).
10103 * Give up on it entirely. */
10105 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
10106 s->kbd_inter_refused = TRUE; /* don't try it again */
10111 * Loop while the server continues to send INFO_REQUESTs.
10113 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
10115 char *name, *inst, *lang;
10116 int name_len, inst_len, lang_len;
10120 * We've got a fresh USERAUTH_INFO_REQUEST.
10121 * Get the preamble and start building a prompt.
10123 ssh_pkt_getstring(pktin, &name, &name_len);
10124 ssh_pkt_getstring(pktin, &inst, &inst_len);
10125 ssh_pkt_getstring(pktin, &lang, &lang_len);
10126 s->cur_prompt = new_prompts(ssh->frontend);
10127 s->cur_prompt->to_server = TRUE;
10130 * Get any prompt(s) from the packet.
10132 s->num_prompts = ssh_pkt_getuint32(pktin);
10133 for (i = 0; i < s->num_prompts; i++) {
10137 static char noprompt[] =
10138 "<server failed to send prompt>: ";
10140 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10141 echo = ssh2_pkt_getbool(pktin);
10144 prompt_len = lenof(noprompt)-1;
10146 add_prompt(s->cur_prompt,
10147 dupprintf("%.*s", prompt_len, prompt),
10152 /* FIXME: better prefix to distinguish from
10153 * local prompts? */
10154 s->cur_prompt->name =
10155 dupprintf("SSH server: %.*s", name_len, name);
10156 s->cur_prompt->name_reqd = TRUE;
10158 s->cur_prompt->name =
10159 dupstr("SSH server authentication");
10160 s->cur_prompt->name_reqd = FALSE;
10162 /* We add a prefix to try to make it clear that a prompt
10163 * has come from the server.
10164 * FIXME: ugly to print "Using..." in prompt _every_
10165 * time round. Can this be done more subtly? */
10166 /* Special case: for reasons best known to themselves,
10167 * some servers send k-i requests with no prompts and
10168 * nothing to display. Keep quiet in this case. */
10169 if (s->num_prompts || name_len || inst_len) {
10170 s->cur_prompt->instruction =
10171 dupprintf("Using keyboard-interactive authentication.%s%.*s",
10172 inst_len ? "\n" : "", inst_len, inst);
10173 s->cur_prompt->instr_reqd = TRUE;
10175 s->cur_prompt->instr_reqd = FALSE;
10179 * Display any instructions, and get the user's
10183 int ret; /* not live over crReturn */
10184 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10187 crWaitUntilV(!pktin);
10188 ret = get_userpass_input(s->cur_prompt, in, inlen);
10193 * Failed to get responses. Terminate.
10195 free_prompts(s->cur_prompt);
10196 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10197 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10204 * Send the response(s) to the server.
10206 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10207 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
10208 for (i=0; i < s->num_prompts; i++) {
10209 ssh2_pkt_addstring(s->pktout,
10210 s->cur_prompt->prompts[i]->result);
10212 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10215 * Free the prompts structure from this iteration.
10216 * If there's another, a new one will be allocated
10217 * when we return to the top of this while loop.
10219 free_prompts(s->cur_prompt);
10222 * Get the next packet in case it's another
10225 crWaitUntilV(pktin);
10230 * We should have SUCCESS or FAILURE now.
10234 } else if (s->can_passwd) {
10237 * Plain old password authentication.
10239 int ret; /* not live over crReturn */
10240 int changereq_first_time; /* not live over crReturn */
10242 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
10244 s->cur_prompt = new_prompts(ssh->frontend);
10245 s->cur_prompt->to_server = TRUE;
10246 s->cur_prompt->name = dupstr("SSH password");
10247 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
10252 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10255 crWaitUntilV(!pktin);
10256 ret = get_userpass_input(s->cur_prompt, in, inlen);
10261 * Failed to get responses. Terminate.
10263 free_prompts(s->cur_prompt);
10264 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10265 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10270 * Squirrel away the password. (We may need it later if
10271 * asked to change it.)
10273 s->password = dupstr(s->cur_prompt->prompts[0]->result);
10274 free_prompts(s->cur_prompt);
10277 * Send the password packet.
10279 * We pad out the password packet to 256 bytes to make
10280 * it harder for an attacker to find the length of the
10283 * Anyone using a password longer than 256 bytes
10284 * probably doesn't have much to worry about from
10285 * people who find out how long their password is!
10287 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10288 ssh2_pkt_addstring(s->pktout, ssh->username);
10289 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10290 /* service requested */
10291 ssh2_pkt_addstring(s->pktout, "password");
10292 ssh2_pkt_addbool(s->pktout, FALSE);
10293 ssh2_pkt_addstring(s->pktout, s->password);
10294 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10295 logevent("Sent password");
10296 s->type = AUTH_TYPE_PASSWORD;
10299 * Wait for next packet, in case it's a password change
10302 crWaitUntilV(pktin);
10303 changereq_first_time = TRUE;
10305 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
10308 * We're being asked for a new password
10309 * (perhaps not for the first time).
10310 * Loop until the server accepts it.
10313 int got_new = FALSE; /* not live over crReturn */
10314 char *prompt; /* not live over crReturn */
10315 int prompt_len; /* not live over crReturn */
10319 if (changereq_first_time)
10320 msg = "Server requested password change";
10322 msg = "Server rejected new password";
10324 c_write_str(ssh, msg);
10325 c_write_str(ssh, "\r\n");
10328 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
10330 s->cur_prompt = new_prompts(ssh->frontend);
10331 s->cur_prompt->to_server = TRUE;
10332 s->cur_prompt->name = dupstr("New SSH password");
10333 s->cur_prompt->instruction =
10334 dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt));
10335 s->cur_prompt->instr_reqd = TRUE;
10337 * There's no explicit requirement in the protocol
10338 * for the "old" passwords in the original and
10339 * password-change messages to be the same, and
10340 * apparently some Cisco kit supports password change
10341 * by the user entering a blank password originally
10342 * and the real password subsequently, so,
10343 * reluctantly, we prompt for the old password again.
10345 * (On the other hand, some servers don't even bother
10346 * to check this field.)
10348 add_prompt(s->cur_prompt,
10349 dupstr("Current password (blank for previously entered password): "),
10351 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
10353 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
10357 * Loop until the user manages to enter the same
10362 ret = get_userpass_input(s->cur_prompt, NULL, 0);
10365 crWaitUntilV(!pktin);
10366 ret = get_userpass_input(s->cur_prompt, in, inlen);
10371 * Failed to get responses. Terminate.
10373 /* burn the evidence */
10374 free_prompts(s->cur_prompt);
10375 smemclr(s->password, strlen(s->password));
10376 sfree(s->password);
10377 ssh_disconnect(ssh, NULL, "Unable to authenticate",
10378 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
10384 * If the user specified a new original password
10385 * (IYSWIM), overwrite any previously specified
10387 * (A side effect is that the user doesn't have to
10388 * re-enter it if they louse up the new password.)
10390 if (s->cur_prompt->prompts[0]->result[0]) {
10391 smemclr(s->password, strlen(s->password));
10392 /* burn the evidence */
10393 sfree(s->password);
10395 dupstr(s->cur_prompt->prompts[0]->result);
10399 * Check the two new passwords match.
10401 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
10402 s->cur_prompt->prompts[2]->result)
10405 /* They don't. Silly user. */
10406 c_write_str(ssh, "Passwords do not match\r\n");
10411 * Send the new password (along with the old one).
10412 * (see above for padding rationale)
10414 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
10415 ssh2_pkt_addstring(s->pktout, ssh->username);
10416 ssh2_pkt_addstring(s->pktout, "ssh-connection");
10417 /* service requested */
10418 ssh2_pkt_addstring(s->pktout, "password");
10419 ssh2_pkt_addbool(s->pktout, TRUE);
10420 ssh2_pkt_addstring(s->pktout, s->password);
10421 ssh2_pkt_addstring(s->pktout,
10422 s->cur_prompt->prompts[1]->result);
10423 free_prompts(s->cur_prompt);
10424 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
10425 logevent("Sent new password");
10428 * Now see what the server has to say about it.
10429 * (If it's CHANGEREQ again, it's not happy with the
10432 crWaitUntilV(pktin);
10433 changereq_first_time = FALSE;
10438 * We need to reexamine the current pktin at the top
10439 * of the loop. Either:
10440 * - we weren't asked to change password at all, in
10441 * which case it's a SUCCESS or FAILURE with the
10443 * - we sent a new password, and the server was
10444 * either OK with it (SUCCESS or FAILURE w/partial
10445 * success) or unhappy with the _old_ password
10446 * (FAILURE w/o partial success)
10447 * In any of these cases, we go back to the top of
10448 * the loop and start again.
10453 * We don't need the old password any more, in any
10454 * case. Burn the evidence.
10456 smemclr(s->password, strlen(s->password));
10457 sfree(s->password);
10460 char *str = dupprintf("No supported authentication methods available"
10461 " (server sent: %.*s)",
10464 ssh_disconnect(ssh, str,
10465 "No supported authentication methods available",
10466 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10476 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10478 /* Clear up various bits and pieces from authentication. */
10479 if (s->publickey_blob) {
10480 sfree(s->publickey_algorithm);
10481 sfree(s->publickey_blob);
10482 sfree(s->publickey_comment);
10484 if (s->agent_response)
10485 sfree(s->agent_response);
10487 if (s->userauth_success && !ssh->bare_connection) {
10489 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10490 * packets since. Signal the transport layer to consider enacting
10491 * delayed compression.
10493 * (Relying on we_are_in is not sufficient, as
10494 * draft-miller-secsh-compression-delayed is quite clear that it
10495 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10496 * become set for other reasons.)
10498 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10501 ssh->channels = newtree234(ssh_channelcmp);
10504 * Set up handlers for some connection protocol messages, so we
10505 * don't have to handle them repeatedly in this coroutine.
10507 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10508 ssh2_msg_channel_window_adjust;
10509 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10510 ssh2_msg_global_request;
10513 * Create the main session channel.
10515 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10516 ssh->mainchan = NULL;
10518 ssh->mainchan = snew(struct ssh_channel);
10519 ssh->mainchan->ssh = ssh;
10520 ssh2_channel_init(ssh->mainchan);
10522 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10524 * Just start a direct-tcpip channel and use it as the main
10527 ssh_send_port_open(ssh->mainchan,
10528 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10529 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10531 ssh->ncmode = TRUE;
10533 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10534 logevent("Opening session as main channel");
10535 ssh2_pkt_send(ssh, s->pktout);
10536 ssh->ncmode = FALSE;
10538 crWaitUntilV(pktin);
10539 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10540 bombout(("Server refused to open channel"));
10542 /* FIXME: error data comes back in FAILURE packet */
10544 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10545 bombout(("Server's channel confirmation cited wrong channel"));
10548 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10549 ssh->mainchan->halfopen = FALSE;
10550 ssh->mainchan->type = CHAN_MAINSESSION;
10551 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10552 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10553 add234(ssh->channels, ssh->mainchan);
10554 update_specials_menu(ssh->frontend);
10555 logevent("Opened main channel");
10559 * Now we have a channel, make dispatch table entries for
10560 * general channel-based messages.
10562 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10563 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10564 ssh2_msg_channel_data;
10565 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10566 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10567 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10568 ssh2_msg_channel_open_confirmation;
10569 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10570 ssh2_msg_channel_open_failure;
10571 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10572 ssh2_msg_channel_request;
10573 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10574 ssh2_msg_channel_open;
10575 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10576 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10579 * Now the connection protocol is properly up and running, with
10580 * all those dispatch table entries, so it's safe to let
10581 * downstreams start trying to open extra channels through us.
10583 if (ssh->connshare)
10584 share_activate(ssh->connshare, ssh->v_s);
10586 if (ssh->mainchan && ssh_is_simple(ssh)) {
10588 * This message indicates to the server that we promise
10589 * not to try to run any other channel in parallel with
10590 * this one, so it's safe for it to advertise a very large
10591 * window and leave the flow control to TCP.
10593 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10594 "simple@putty.projects.tartarus.org",
10596 ssh2_pkt_send(ssh, s->pktout);
10600 * Enable port forwardings.
10602 ssh_setup_portfwd(ssh, ssh->conf);
10604 if (ssh->mainchan && !ssh->ncmode) {
10606 * Send the CHANNEL_REQUESTS for the main session channel.
10607 * Each one is handled by its own little asynchronous
10611 /* Potentially enable X11 forwarding. */
10612 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10614 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10616 if (!ssh->x11disp) {
10617 /* FIXME: return an error message from x11_setup_display */
10618 logevent("X11 forwarding not enabled: unable to"
10619 " initialise X display");
10621 ssh->x11auth = x11_invent_fake_auth
10622 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10623 ssh->x11auth->disp = ssh->x11disp;
10625 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10629 /* Potentially enable agent forwarding. */
10630 if (ssh_agent_forwarding_permitted(ssh))
10631 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10633 /* Now allocate a pty for the session. */
10634 if (!conf_get_int(ssh->conf, CONF_nopty))
10635 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10637 /* Send environment variables. */
10638 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10641 * Start a shell or a remote command. We may have to attempt
10642 * this twice if the config data has provided a second choice
10649 if (ssh->fallback_cmd) {
10650 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10651 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10653 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10654 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10658 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10659 ssh2_response_authconn, NULL);
10660 ssh2_pkt_addstring(s->pktout, cmd);
10662 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10663 ssh2_response_authconn, NULL);
10664 ssh2_pkt_addstring(s->pktout, cmd);
10666 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10667 ssh2_response_authconn, NULL);
10669 ssh2_pkt_send(ssh, s->pktout);
10671 crWaitUntilV(pktin);
10673 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10674 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10675 bombout(("Unexpected response to shell/command request:"
10676 " packet type %d", pktin->type));
10680 * We failed to start the command. If this is the
10681 * fallback command, we really are finished; if it's
10682 * not, and if the fallback command exists, try falling
10683 * back to it before complaining.
10685 if (!ssh->fallback_cmd &&
10686 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10687 logevent("Primary command failed; attempting fallback");
10688 ssh->fallback_cmd = TRUE;
10691 bombout(("Server refused to start a shell/command"));
10694 logevent("Started a shell/command");
10699 ssh->editing = ssh->echoing = TRUE;
10702 ssh->state = SSH_STATE_SESSION;
10703 if (ssh->size_needed)
10704 ssh_size(ssh, ssh->term_width, ssh->term_height);
10705 if (ssh->eof_needed)
10706 ssh_special(ssh, TS_EOF);
10712 ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */
10717 s->try_send = FALSE;
10721 * _All_ the connection-layer packets we expect to
10722 * receive are now handled by the dispatch table.
10723 * Anything that reaches here must be bogus.
10726 bombout(("Strange packet received: type %d", pktin->type));
10728 } else if (ssh->mainchan) {
10730 * We have spare data. Add it to the channel buffer.
10732 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10733 s->try_send = TRUE;
10737 struct ssh_channel *c;
10739 * Try to send data on all channels if we can.
10741 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10742 if (c->type != CHAN_SHARING)
10743 ssh2_try_send_and_unthrottle(ssh, c);
10751 * Handlers for SSH-2 messages that might arrive at any moment.
10753 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10755 /* log reason code in disconnect message */
10757 int reason, msglen;
10759 reason = ssh_pkt_getuint32(pktin);
10760 ssh_pkt_getstring(pktin, &msg, &msglen);
10762 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10763 buf = dupprintf("Received disconnect message (%s)",
10764 ssh2_disconnect_reasons[reason]);
10766 buf = dupprintf("Received disconnect message (unknown"
10767 " type %d)", reason);
10771 buf = dupprintf("Disconnection message text: %.*s",
10772 msglen, NULLTOEMPTY(msg));
10774 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10776 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10777 ssh2_disconnect_reasons[reason] : "unknown",
10778 msglen, NULLTOEMPTY(msg)));
10782 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10784 /* log the debug message */
10788 /* XXX maybe we should actually take notice of the return value */
10789 ssh2_pkt_getbool(pktin);
10790 ssh_pkt_getstring(pktin, &msg, &msglen);
10792 logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg));
10795 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10797 do_ssh2_transport(ssh, NULL, 0, pktin);
10801 * Called if we receive a packet that isn't allowed by the protocol.
10802 * This only applies to packets whose meaning PuTTY understands.
10803 * Entirely unknown packets are handled below.
10805 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10807 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10808 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10810 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10814 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10816 struct Packet *pktout;
10817 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10818 ssh2_pkt_adduint32(pktout, pktin->sequence);
10820 * UNIMPLEMENTED messages MUST appear in the same order as the
10821 * messages they respond to. Hence, never queue them.
10823 ssh2_pkt_send_noqueue(ssh, pktout);
10827 * Handle the top-level SSH-2 protocol.
10829 static void ssh2_protocol_setup(Ssh ssh)
10834 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10836 for (i = 0; i < 256; i++)
10837 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10840 * Initially, we only accept transport messages (and a few generic
10841 * ones). do_ssh2_authconn will add more when it starts.
10842 * Messages that are understood but not currently acceptable go to
10843 * ssh2_msg_unexpected.
10845 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10846 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10847 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10848 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10849 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10850 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10851 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10852 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10853 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10854 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10855 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10856 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10857 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10858 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10859 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10860 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10861 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10862 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10863 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10864 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10865 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10866 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10867 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10868 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10869 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10870 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10871 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10872 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10873 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10874 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10875 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10876 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10877 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10880 * These messages have a special handler from the start.
10882 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10883 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10884 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10887 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10892 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10894 for (i = 0; i < 256; i++)
10895 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10898 * Initially, we set all ssh-connection messages to 'unexpected';
10899 * do_ssh2_authconn will fill things in properly. We also handle a
10900 * couple of messages from the transport protocol which aren't
10901 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10904 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10905 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10906 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10907 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10908 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10909 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10910 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10911 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10912 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10913 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10914 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10915 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10916 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10917 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10919 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10922 * These messages have a special handler from the start.
10924 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10925 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10926 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10929 static void ssh2_timer(void *ctx, unsigned long now)
10931 Ssh ssh = (Ssh)ctx;
10933 if (ssh->state == SSH_STATE_CLOSED)
10936 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10937 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10938 now == ssh->next_rekey) {
10939 do_ssh2_transport(ssh, "timeout", -1, NULL);
10943 static void ssh2_protocol(Ssh ssh, const void *vin, int inlen,
10944 struct Packet *pktin)
10946 const unsigned char *in = (const unsigned char *)vin;
10947 if (ssh->state == SSH_STATE_CLOSED)
10951 ssh->incoming_data_size += pktin->encrypted_len;
10952 if (!ssh->kex_in_progress &&
10953 ssh->max_data_size != 0 &&
10954 ssh->incoming_data_size > ssh->max_data_size)
10955 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10959 ssh->packet_dispatch[pktin->type](ssh, pktin);
10960 else if (!ssh->protocol_initial_phase_done)
10961 do_ssh2_transport(ssh, in, inlen, pktin);
10963 do_ssh2_authconn(ssh, in, inlen, pktin);
10966 static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen,
10967 struct Packet *pktin)
10969 const unsigned char *in = (const unsigned char *)vin;
10970 if (ssh->state == SSH_STATE_CLOSED)
10974 ssh->packet_dispatch[pktin->type](ssh, pktin);
10976 do_ssh2_authconn(ssh, in, inlen, pktin);
10979 static void ssh_cache_conf_values(Ssh ssh)
10981 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10985 * Called to set up the connection.
10987 * Returns an error message, or NULL on success.
10989 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10991 const char *host, int port, char **realhost,
10992 int nodelay, int keepalive)
10997 ssh = snew(struct ssh_tag);
10998 ssh->conf = conf_copy(conf);
10999 ssh_cache_conf_values(ssh);
11000 ssh->version = 0; /* when not ready yet */
11002 ssh->cipher = NULL;
11003 ssh->v1_cipher_ctx = NULL;
11004 ssh->crcda_ctx = NULL;
11005 ssh->cscipher = NULL;
11006 ssh->cs_cipher_ctx = NULL;
11007 ssh->sccipher = NULL;
11008 ssh->sc_cipher_ctx = NULL;
11010 ssh->cs_mac_ctx = NULL;
11012 ssh->sc_mac_ctx = NULL;
11013 ssh->cscomp = NULL;
11014 ssh->cs_comp_ctx = NULL;
11015 ssh->sccomp = NULL;
11016 ssh->sc_comp_ctx = NULL;
11018 ssh->kex_ctx = NULL;
11019 ssh->hostkey = NULL;
11020 ssh->hostkey_str = NULL;
11021 ssh->exitcode = -1;
11022 ssh->close_expected = FALSE;
11023 ssh->clean_exit = FALSE;
11024 ssh->state = SSH_STATE_PREPACKET;
11025 ssh->size_needed = FALSE;
11026 ssh->eof_needed = FALSE;
11028 ssh->logctx = NULL;
11029 ssh->deferred_send_data = NULL;
11030 ssh->deferred_len = 0;
11031 ssh->deferred_size = 0;
11032 ssh->fallback_cmd = 0;
11033 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
11034 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
11035 ssh->x11disp = NULL;
11036 ssh->x11auth = NULL;
11037 ssh->x11authtree = newtree234(x11_authcmp);
11038 ssh->v1_compressing = FALSE;
11039 ssh->v2_outgoing_sequence = 0;
11040 ssh->ssh1_rdpkt_crstate = 0;
11041 ssh->ssh2_rdpkt_crstate = 0;
11042 ssh->ssh2_bare_rdpkt_crstate = 0;
11043 ssh->ssh_gotdata_crstate = 0;
11044 ssh->do_ssh1_connection_crstate = 0;
11045 ssh->do_ssh_init_state = NULL;
11046 ssh->do_ssh_connection_init_state = NULL;
11047 ssh->do_ssh1_login_state = NULL;
11048 ssh->do_ssh2_transport_state = NULL;
11049 ssh->do_ssh2_authconn_state = NULL;
11052 ssh->mainchan = NULL;
11053 ssh->throttled_all = 0;
11054 ssh->v1_stdout_throttling = 0;
11056 ssh->queuelen = ssh->queuesize = 0;
11057 ssh->queueing = FALSE;
11058 ssh->qhead = ssh->qtail = NULL;
11059 ssh->deferred_rekey_reason = NULL;
11060 bufchain_init(&ssh->queued_incoming_data);
11061 ssh->frozen = FALSE;
11062 ssh->username = NULL;
11063 ssh->sent_console_eof = FALSE;
11064 ssh->got_pty = FALSE;
11065 ssh->bare_connection = FALSE;
11066 ssh->X11_fwd_enabled = FALSE;
11067 ssh->connshare = NULL;
11068 ssh->attempting_connshare = FALSE;
11069 ssh->session_started = FALSE;
11070 ssh->specials = NULL;
11071 ssh->n_uncert_hostkeys = 0;
11072 ssh->cross_certifying = FALSE;
11074 *backend_handle = ssh;
11077 if (crypto_startup() == 0)
11078 return "Microsoft high encryption pack not installed!";
11081 ssh->frontend = frontend_handle;
11082 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
11083 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
11085 ssh->channels = NULL;
11086 ssh->rportfwds = NULL;
11087 ssh->portfwds = NULL;
11092 ssh->conn_throttle_count = 0;
11093 ssh->overall_bufsize = 0;
11094 ssh->fallback_cmd = 0;
11096 ssh->protocol = NULL;
11098 ssh->protocol_initial_phase_done = FALSE;
11100 ssh->pinger = NULL;
11102 ssh->incoming_data_size = ssh->outgoing_data_size =
11103 ssh->deferred_data_size = 0L;
11104 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11105 CONF_ssh_rekey_data));
11106 ssh->kex_in_progress = FALSE;
11109 ssh->gsslibs = NULL;
11112 random_ref(); /* do this now - may be needed by sharing setup code */
11114 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
11123 static void ssh_free(void *handle)
11125 Ssh ssh = (Ssh) handle;
11126 struct ssh_channel *c;
11127 struct ssh_rportfwd *pf;
11128 struct X11FakeAuth *auth;
11130 if (ssh->v1_cipher_ctx)
11131 ssh->cipher->free_context(ssh->v1_cipher_ctx);
11132 if (ssh->cs_cipher_ctx)
11133 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
11134 if (ssh->sc_cipher_ctx)
11135 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
11136 if (ssh->cs_mac_ctx)
11137 ssh->csmac->free_context(ssh->cs_mac_ctx);
11138 if (ssh->sc_mac_ctx)
11139 ssh->scmac->free_context(ssh->sc_mac_ctx);
11140 if (ssh->cs_comp_ctx) {
11142 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
11144 zlib_compress_cleanup(ssh->cs_comp_ctx);
11146 if (ssh->sc_comp_ctx) {
11148 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
11150 zlib_decompress_cleanup(ssh->sc_comp_ctx);
11153 dh_cleanup(ssh->kex_ctx);
11154 sfree(ssh->savedhost);
11156 while (ssh->queuelen-- > 0)
11157 ssh_free_packet(ssh->queue[ssh->queuelen]);
11160 while (ssh->qhead) {
11161 struct queued_handler *qh = ssh->qhead;
11162 ssh->qhead = qh->next;
11165 ssh->qhead = ssh->qtail = NULL;
11167 if (ssh->channels) {
11168 while ((c = delpos234(ssh->channels, 0)) != NULL) {
11171 if (c->u.x11.xconn != NULL)
11172 x11_close(c->u.x11.xconn);
11174 case CHAN_SOCKDATA:
11175 case CHAN_SOCKDATA_DORMANT:
11176 if (c->u.pfd.pf != NULL)
11177 pfd_close(c->u.pfd.pf);
11180 if (ssh->version == 2) {
11181 struct outstanding_channel_request *ocr, *nocr;
11182 ocr = c->v.v2.chanreq_head;
11184 ocr->handler(c, NULL, ocr->ctx);
11189 bufchain_clear(&c->v.v2.outbuffer);
11193 freetree234(ssh->channels);
11194 ssh->channels = NULL;
11197 if (ssh->connshare)
11198 sharestate_free(ssh->connshare);
11200 if (ssh->rportfwds) {
11201 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
11203 freetree234(ssh->rportfwds);
11204 ssh->rportfwds = NULL;
11206 sfree(ssh->deferred_send_data);
11208 x11_free_display(ssh->x11disp);
11209 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
11210 x11_free_fake_auth(auth);
11211 freetree234(ssh->x11authtree);
11212 sfree(ssh->do_ssh_init_state);
11213 sfree(ssh->do_ssh1_login_state);
11214 sfree(ssh->do_ssh2_transport_state);
11215 sfree(ssh->do_ssh2_authconn_state);
11218 sfree(ssh->fullhostname);
11219 sfree(ssh->hostkey_str);
11220 sfree(ssh->specials);
11221 if (ssh->crcda_ctx) {
11222 crcda_free_context(ssh->crcda_ctx);
11223 ssh->crcda_ctx = NULL;
11226 ssh_do_close(ssh, TRUE);
11227 expire_timer_context(ssh);
11229 pinger_free(ssh->pinger);
11230 bufchain_clear(&ssh->queued_incoming_data);
11231 sfree(ssh->username);
11232 conf_free(ssh->conf);
11235 ssh_gss_cleanup(ssh->gsslibs);
11243 * Reconfigure the SSH backend.
11245 static void ssh_reconfig(void *handle, Conf *conf)
11247 Ssh ssh = (Ssh) handle;
11248 const char *rekeying = NULL;
11249 int rekey_mandatory = FALSE;
11250 unsigned long old_max_data_size;
11253 pinger_reconfig(ssh->pinger, ssh->conf, conf);
11255 ssh_setup_portfwd(ssh, conf);
11257 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
11258 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
11260 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
11261 unsigned long now = GETTICKCOUNT();
11263 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
11264 rekeying = "timeout shortened";
11266 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
11270 old_max_data_size = ssh->max_data_size;
11271 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
11272 CONF_ssh_rekey_data));
11273 if (old_max_data_size != ssh->max_data_size &&
11274 ssh->max_data_size != 0) {
11275 if (ssh->outgoing_data_size > ssh->max_data_size ||
11276 ssh->incoming_data_size > ssh->max_data_size)
11277 rekeying = "data limit lowered";
11280 if (conf_get_int(ssh->conf, CONF_compression) !=
11281 conf_get_int(conf, CONF_compression)) {
11282 rekeying = "compression setting changed";
11283 rekey_mandatory = TRUE;
11286 for (i = 0; i < CIPHER_MAX; i++)
11287 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
11288 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
11289 rekeying = "cipher settings changed";
11290 rekey_mandatory = TRUE;
11292 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
11293 conf_get_int(conf, CONF_ssh2_des_cbc)) {
11294 rekeying = "cipher settings changed";
11295 rekey_mandatory = TRUE;
11298 conf_free(ssh->conf);
11299 ssh->conf = conf_copy(conf);
11300 ssh_cache_conf_values(ssh);
11302 if (!ssh->bare_connection && rekeying) {
11303 if (!ssh->kex_in_progress) {
11304 do_ssh2_transport(ssh, rekeying, -1, NULL);
11305 } else if (rekey_mandatory) {
11306 ssh->deferred_rekey_reason = rekeying;
11312 * Called to send data down the SSH connection.
11314 static int ssh_send(void *handle, const char *buf, int len)
11316 Ssh ssh = (Ssh) handle;
11318 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11321 ssh->protocol(ssh, (const unsigned char *)buf, len, 0);
11323 return ssh_sendbuffer(ssh);
11327 * Called to query the current amount of buffered stdin data.
11329 static int ssh_sendbuffer(void *handle)
11331 Ssh ssh = (Ssh) handle;
11332 int override_value;
11334 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
11338 * If the SSH socket itself has backed up, add the total backup
11339 * size on that to any individual buffer on the stdin channel.
11341 override_value = 0;
11342 if (ssh->throttled_all)
11343 override_value = ssh->overall_bufsize;
11345 if (ssh->version == 1) {
11346 return override_value;
11347 } else if (ssh->version == 2) {
11348 if (!ssh->mainchan)
11349 return override_value;
11351 return (override_value +
11352 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
11359 * Called to set the size of the window from SSH's POV.
11361 static void ssh_size(void *handle, int width, int height)
11363 Ssh ssh = (Ssh) handle;
11364 struct Packet *pktout;
11366 ssh->term_width = width;
11367 ssh->term_height = height;
11369 switch (ssh->state) {
11370 case SSH_STATE_BEFORE_SIZE:
11371 case SSH_STATE_PREPACKET:
11372 case SSH_STATE_CLOSED:
11373 break; /* do nothing */
11374 case SSH_STATE_INTERMED:
11375 ssh->size_needed = TRUE; /* buffer for later */
11377 case SSH_STATE_SESSION:
11378 if (!conf_get_int(ssh->conf, CONF_nopty)) {
11379 if (ssh->version == 1) {
11380 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
11381 PKT_INT, ssh->term_height,
11382 PKT_INT, ssh->term_width,
11383 PKT_INT, 0, PKT_INT, 0, PKT_END);
11384 } else if (ssh->mainchan) {
11385 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
11387 ssh2_pkt_adduint32(pktout, ssh->term_width);
11388 ssh2_pkt_adduint32(pktout, ssh->term_height);
11389 ssh2_pkt_adduint32(pktout, 0);
11390 ssh2_pkt_adduint32(pktout, 0);
11391 ssh2_pkt_send(ssh, pktout);
11399 * Return a list of the special codes that make sense in this
11402 static const struct telnet_special *ssh_get_specials(void *handle)
11404 static const struct telnet_special ssh1_ignore_special[] = {
11405 {"IGNORE message", TS_NOP}
11407 static const struct telnet_special ssh2_ignore_special[] = {
11408 {"IGNORE message", TS_NOP},
11410 static const struct telnet_special ssh2_rekey_special[] = {
11411 {"Repeat key exchange", TS_REKEY},
11413 static const struct telnet_special ssh2_session_specials[] = {
11416 /* These are the signal names defined by RFC 4254.
11417 * They include all the ISO C signals, but are a subset of the POSIX
11418 * required signals. */
11419 {"SIGINT (Interrupt)", TS_SIGINT},
11420 {"SIGTERM (Terminate)", TS_SIGTERM},
11421 {"SIGKILL (Kill)", TS_SIGKILL},
11422 {"SIGQUIT (Quit)", TS_SIGQUIT},
11423 {"SIGHUP (Hangup)", TS_SIGHUP},
11424 {"More signals", TS_SUBMENU},
11425 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
11426 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
11427 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
11428 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
11429 {NULL, TS_EXITMENU}
11431 static const struct telnet_special specials_end[] = {
11432 {NULL, TS_EXITMENU}
11435 struct telnet_special *specials = NULL;
11436 int nspecials = 0, specialsize = 0;
11438 Ssh ssh = (Ssh) handle;
11440 sfree(ssh->specials);
11442 #define ADD_SPECIALS(name) do \
11444 int len = lenof(name); \
11445 if (nspecials + len > specialsize) { \
11446 specialsize = (nspecials + len) * 5 / 4 + 32; \
11447 specials = sresize(specials, specialsize, struct telnet_special); \
11449 memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \
11450 nspecials += len; \
11453 if (ssh->version == 1) {
11454 /* Don't bother offering IGNORE if we've decided the remote
11455 * won't cope with it, since we wouldn't bother sending it if
11457 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11458 ADD_SPECIALS(ssh1_ignore_special);
11459 } else if (ssh->version == 2) {
11460 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
11461 ADD_SPECIALS(ssh2_ignore_special);
11462 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
11463 ADD_SPECIALS(ssh2_rekey_special);
11465 ADD_SPECIALS(ssh2_session_specials);
11467 if (ssh->n_uncert_hostkeys) {
11468 static const struct telnet_special uncert_start[] = {
11470 {"Cache new host key type", TS_SUBMENU},
11472 static const struct telnet_special uncert_end[] = {
11473 {NULL, TS_EXITMENU},
11477 ADD_SPECIALS(uncert_start);
11478 for (i = 0; i < ssh->n_uncert_hostkeys; i++) {
11479 struct telnet_special uncert[1];
11480 const struct ssh_signkey *alg =
11481 hostkey_algs[ssh->uncert_hostkeys[i]];
11482 uncert[0].name = alg->name;
11483 uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i];
11484 ADD_SPECIALS(uncert);
11486 ADD_SPECIALS(uncert_end);
11488 } /* else we're not ready yet */
11491 ADD_SPECIALS(specials_end);
11493 ssh->specials = specials;
11500 #undef ADD_SPECIALS
11504 * Send special codes. TS_EOF is useful for `plink', so you
11505 * can send an EOF and collect resulting output (e.g. `plink
11508 static void ssh_special(void *handle, Telnet_Special code)
11510 Ssh ssh = (Ssh) handle;
11511 struct Packet *pktout;
11513 if (code == TS_EOF) {
11514 if (ssh->state != SSH_STATE_SESSION) {
11516 * Buffer the EOF in case we are pre-SESSION, so we can
11517 * send it as soon as we reach SESSION.
11519 if (code == TS_EOF)
11520 ssh->eof_needed = TRUE;
11523 if (ssh->version == 1) {
11524 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11525 } else if (ssh->mainchan) {
11526 sshfwd_write_eof(ssh->mainchan);
11527 ssh->send_ok = 0; /* now stop trying to read from stdin */
11529 logevent("Sent EOF message");
11530 } else if (code == TS_PING || code == TS_NOP) {
11531 if (ssh->state == SSH_STATE_CLOSED
11532 || ssh->state == SSH_STATE_PREPACKET) return;
11533 if (ssh->version == 1) {
11534 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11535 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11537 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11538 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11539 ssh2_pkt_addstring_start(pktout);
11540 ssh2_pkt_send_noqueue(ssh, pktout);
11543 } else if (code == TS_REKEY) {
11544 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11545 ssh->version == 2) {
11546 do_ssh2_transport(ssh, "at user request", -1, NULL);
11548 } else if (code >= TS_LOCALSTART) {
11549 ssh->hostkey = hostkey_algs[code - TS_LOCALSTART];
11550 ssh->cross_certifying = TRUE;
11551 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11552 ssh->version == 2) {
11553 do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL);
11555 } else if (code == TS_BRK) {
11556 if (ssh->state == SSH_STATE_CLOSED
11557 || ssh->state == SSH_STATE_PREPACKET) return;
11558 if (ssh->version == 1) {
11559 logevent("Unable to send BREAK signal in SSH-1");
11560 } else if (ssh->mainchan) {
11561 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11562 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11563 ssh2_pkt_send(ssh, pktout);
11566 /* Is is a POSIX signal? */
11567 const char *signame = NULL;
11568 if (code == TS_SIGABRT) signame = "ABRT";
11569 if (code == TS_SIGALRM) signame = "ALRM";
11570 if (code == TS_SIGFPE) signame = "FPE";
11571 if (code == TS_SIGHUP) signame = "HUP";
11572 if (code == TS_SIGILL) signame = "ILL";
11573 if (code == TS_SIGINT) signame = "INT";
11574 if (code == TS_SIGKILL) signame = "KILL";
11575 if (code == TS_SIGPIPE) signame = "PIPE";
11576 if (code == TS_SIGQUIT) signame = "QUIT";
11577 if (code == TS_SIGSEGV) signame = "SEGV";
11578 if (code == TS_SIGTERM) signame = "TERM";
11579 if (code == TS_SIGUSR1) signame = "USR1";
11580 if (code == TS_SIGUSR2) signame = "USR2";
11581 /* The SSH-2 protocol does in principle support arbitrary named
11582 * signals, including signame@domain, but we don't support those. */
11584 /* It's a signal. */
11585 if (ssh->version == 2 && ssh->mainchan) {
11586 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11587 ssh2_pkt_addstring(pktout, signame);
11588 ssh2_pkt_send(ssh, pktout);
11589 logeventf(ssh, "Sent signal SIG%s", signame);
11592 /* Never heard of it. Do nothing */
11597 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11599 Ssh ssh = (Ssh) handle;
11600 struct ssh_channel *c;
11601 c = snew(struct ssh_channel);
11604 ssh2_channel_init(c);
11605 c->halfopen = TRUE;
11606 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11608 add234(ssh->channels, c);
11612 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11614 struct ssh_channel *c;
11615 c = snew(struct ssh_channel);
11618 ssh2_channel_init(c);
11619 c->type = CHAN_SHARING;
11620 c->u.sharing.ctx = sharing_ctx;
11621 add234(ssh->channels, c);
11625 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11627 struct ssh_channel *c;
11629 c = find234(ssh->channels, &localid, ssh_channelfind);
11631 ssh_channel_destroy(c);
11634 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11635 const void *data, int datalen,
11636 const char *additional_log_text)
11638 struct Packet *pkt;
11640 pkt = ssh2_pkt_init(type);
11641 pkt->downstream_id = id;
11642 pkt->additional_log_text = additional_log_text;
11643 ssh2_pkt_adddata(pkt, data, datalen);
11644 ssh2_pkt_send(ssh, pkt);
11648 * This is called when stdout/stderr (the entity to which
11649 * from_backend sends data) manages to clear some backlog.
11651 static void ssh_unthrottle(void *handle, int bufsize)
11653 Ssh ssh = (Ssh) handle;
11656 if (ssh->version == 1) {
11657 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11658 ssh->v1_stdout_throttling = 0;
11659 ssh_throttle_conn(ssh, -1);
11662 if (ssh->mainchan) {
11663 ssh2_set_window(ssh->mainchan,
11664 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11665 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11666 if (ssh_is_simple(ssh))
11669 buflimit = ssh->mainchan->v.v2.locmaxwin;
11670 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11671 ssh->mainchan->throttling_conn = 0;
11672 ssh_throttle_conn(ssh, -1);
11678 * Now process any SSH connection data that was stashed in our
11679 * queue while we were frozen.
11681 ssh_process_queued_incoming_data(ssh);
11684 void ssh_send_port_open(void *channel, const char *hostname, int port,
11687 struct ssh_channel *c = (struct ssh_channel *)channel;
11689 struct Packet *pktout;
11691 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11693 if (ssh->version == 1) {
11694 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11695 PKT_INT, c->localid,
11698 /* PKT_STR, <org:orgport>, */
11701 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11703 char *trimmed_host = host_strduptrim(hostname);
11704 ssh2_pkt_addstring(pktout, trimmed_host);
11705 sfree(trimmed_host);
11707 ssh2_pkt_adduint32(pktout, port);
11709 * We make up values for the originator data; partly it's
11710 * too much hassle to keep track, and partly I'm not
11711 * convinced the server should be told details like that
11712 * about my local network configuration.
11713 * The "originator IP address" is syntactically a numeric
11714 * IP address, and some servers (e.g., Tectia) get upset
11715 * if it doesn't match this syntax.
11717 ssh2_pkt_addstring(pktout, "0.0.0.0");
11718 ssh2_pkt_adduint32(pktout, 0);
11719 ssh2_pkt_send(ssh, pktout);
11723 static int ssh_connected(void *handle)
11725 Ssh ssh = (Ssh) handle;
11726 return ssh->s != NULL;
11729 static int ssh_sendok(void *handle)
11731 Ssh ssh = (Ssh) handle;
11732 return ssh->send_ok;
11735 static int ssh_ldisc(void *handle, int option)
11737 Ssh ssh = (Ssh) handle;
11738 if (option == LD_ECHO)
11739 return ssh->echoing;
11740 if (option == LD_EDIT)
11741 return ssh->editing;
11745 static void ssh_provide_ldisc(void *handle, void *ldisc)
11747 Ssh ssh = (Ssh) handle;
11748 ssh->ldisc = ldisc;
11751 static void ssh_provide_logctx(void *handle, void *logctx)
11753 Ssh ssh = (Ssh) handle;
11754 ssh->logctx = logctx;
11757 static int ssh_return_exitcode(void *handle)
11759 Ssh ssh = (Ssh) handle;
11760 if (ssh->s != NULL)
11763 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11767 * cfg_info for SSH is the protocol running in this session.
11768 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11769 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11771 static int ssh_cfg_info(void *handle)
11773 Ssh ssh = (Ssh) handle;
11774 if (ssh->version == 0)
11775 return 0; /* don't know yet */
11776 else if (ssh->bare_connection)
11779 return ssh->version;
11783 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11784 * that fails. This variable is the means by which scp.c can reach
11785 * into the SSH code and find out which one it got.
11787 extern int ssh_fallback_cmd(void *handle)
11789 Ssh ssh = (Ssh) handle;
11790 return ssh->fallback_cmd;
11793 Backend ssh_backend = {
11803 ssh_return_exitcode,
11807 ssh_provide_logctx,
11810 ssh_test_for_upstream,