28 * Packet type contexts, so that ssh2_pkt_type can correctly decode
29 * the ambiguous type numbers back into the correct type strings.
39 SSH2_PKTCTX_PUBLICKEY,
45 static const char *const ssh2_disconnect_reasons[] = {
47 "host not allowed to connect",
49 "key exchange failed",
50 "host authentication failed",
53 "service not available",
54 "protocol version not supported",
55 "host key not verifiable",
58 "too many connections",
59 "auth cancelled by user",
60 "no more auth methods available",
65 * Various remote-bug flags.
67 #define BUG_CHOKES_ON_SSH1_IGNORE 1
68 #define BUG_SSH2_HMAC 2
69 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
70 #define BUG_CHOKES_ON_RSA 8
71 #define BUG_SSH2_RSA_PADDING 16
72 #define BUG_SSH2_DERIVEKEY 32
73 #define BUG_SSH2_REKEY 64
74 #define BUG_SSH2_PK_SESSIONID 128
75 #define BUG_SSH2_MAXPKT 256
76 #define BUG_CHOKES_ON_SSH2_IGNORE 512
77 #define BUG_CHOKES_ON_WINADJ 1024
78 #define BUG_SENDS_LATE_REQUEST_REPLY 2048
81 * Codes for terminal modes.
82 * Most of these are the same in SSH-1 and SSH-2.
83 * This list is derived from RFC 4254 and
87 const char* const mode;
89 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
91 /* "V" prefix discarded for special characters relative to SSH specs */
92 { "INTR", 1, TTY_OP_CHAR },
93 { "QUIT", 2, TTY_OP_CHAR },
94 { "ERASE", 3, TTY_OP_CHAR },
95 { "KILL", 4, TTY_OP_CHAR },
96 { "EOF", 5, TTY_OP_CHAR },
97 { "EOL", 6, TTY_OP_CHAR },
98 { "EOL2", 7, TTY_OP_CHAR },
99 { "START", 8, TTY_OP_CHAR },
100 { "STOP", 9, TTY_OP_CHAR },
101 { "SUSP", 10, TTY_OP_CHAR },
102 { "DSUSP", 11, TTY_OP_CHAR },
103 { "REPRINT", 12, TTY_OP_CHAR },
104 { "WERASE", 13, TTY_OP_CHAR },
105 { "LNEXT", 14, TTY_OP_CHAR },
106 { "FLUSH", 15, TTY_OP_CHAR },
107 { "SWTCH", 16, TTY_OP_CHAR },
108 { "STATUS", 17, TTY_OP_CHAR },
109 { "DISCARD", 18, TTY_OP_CHAR },
110 { "IGNPAR", 30, TTY_OP_BOOL },
111 { "PARMRK", 31, TTY_OP_BOOL },
112 { "INPCK", 32, TTY_OP_BOOL },
113 { "ISTRIP", 33, TTY_OP_BOOL },
114 { "INLCR", 34, TTY_OP_BOOL },
115 { "IGNCR", 35, TTY_OP_BOOL },
116 { "ICRNL", 36, TTY_OP_BOOL },
117 { "IUCLC", 37, TTY_OP_BOOL },
118 { "IXON", 38, TTY_OP_BOOL },
119 { "IXANY", 39, TTY_OP_BOOL },
120 { "IXOFF", 40, TTY_OP_BOOL },
121 { "IMAXBEL", 41, TTY_OP_BOOL },
122 { "ISIG", 50, TTY_OP_BOOL },
123 { "ICANON", 51, TTY_OP_BOOL },
124 { "XCASE", 52, TTY_OP_BOOL },
125 { "ECHO", 53, TTY_OP_BOOL },
126 { "ECHOE", 54, TTY_OP_BOOL },
127 { "ECHOK", 55, TTY_OP_BOOL },
128 { "ECHONL", 56, TTY_OP_BOOL },
129 { "NOFLSH", 57, TTY_OP_BOOL },
130 { "TOSTOP", 58, TTY_OP_BOOL },
131 { "IEXTEN", 59, TTY_OP_BOOL },
132 { "ECHOCTL", 60, TTY_OP_BOOL },
133 { "ECHOKE", 61, TTY_OP_BOOL },
134 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
135 { "OPOST", 70, TTY_OP_BOOL },
136 { "OLCUC", 71, TTY_OP_BOOL },
137 { "ONLCR", 72, TTY_OP_BOOL },
138 { "OCRNL", 73, TTY_OP_BOOL },
139 { "ONOCR", 74, TTY_OP_BOOL },
140 { "ONLRET", 75, TTY_OP_BOOL },
141 { "CS7", 90, TTY_OP_BOOL },
142 { "CS8", 91, TTY_OP_BOOL },
143 { "PARENB", 92, TTY_OP_BOOL },
144 { "PARODD", 93, TTY_OP_BOOL }
147 /* Miscellaneous other tty-related constants. */
148 #define SSH_TTY_OP_END 0
149 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
150 #define SSH1_TTY_OP_ISPEED 192
151 #define SSH1_TTY_OP_OSPEED 193
152 #define SSH2_TTY_OP_ISPEED 128
153 #define SSH2_TTY_OP_OSPEED 129
155 /* Helper functions for parsing tty-related config. */
156 static unsigned int ssh_tty_parse_specchar(char *s)
161 ret = ctrlparse(s, &next);
162 if (!next) ret = s[0];
164 ret = 255; /* special value meaning "don't set" */
168 static unsigned int ssh_tty_parse_boolean(char *s)
170 if (stricmp(s, "yes") == 0 ||
171 stricmp(s, "on") == 0 ||
172 stricmp(s, "true") == 0 ||
173 stricmp(s, "+") == 0)
175 else if (stricmp(s, "no") == 0 ||
176 stricmp(s, "off") == 0 ||
177 stricmp(s, "false") == 0 ||
178 stricmp(s, "-") == 0)
179 return 0; /* false */
181 return (atoi(s) != 0);
184 #define translate(x) if (type == x) return #x
185 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
186 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
187 static char *ssh1_pkt_type(int type)
189 translate(SSH1_MSG_DISCONNECT);
190 translate(SSH1_SMSG_PUBLIC_KEY);
191 translate(SSH1_CMSG_SESSION_KEY);
192 translate(SSH1_CMSG_USER);
193 translate(SSH1_CMSG_AUTH_RSA);
194 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
195 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
196 translate(SSH1_CMSG_AUTH_PASSWORD);
197 translate(SSH1_CMSG_REQUEST_PTY);
198 translate(SSH1_CMSG_WINDOW_SIZE);
199 translate(SSH1_CMSG_EXEC_SHELL);
200 translate(SSH1_CMSG_EXEC_CMD);
201 translate(SSH1_SMSG_SUCCESS);
202 translate(SSH1_SMSG_FAILURE);
203 translate(SSH1_CMSG_STDIN_DATA);
204 translate(SSH1_SMSG_STDOUT_DATA);
205 translate(SSH1_SMSG_STDERR_DATA);
206 translate(SSH1_CMSG_EOF);
207 translate(SSH1_SMSG_EXIT_STATUS);
208 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
209 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
210 translate(SSH1_MSG_CHANNEL_DATA);
211 translate(SSH1_MSG_CHANNEL_CLOSE);
212 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
213 translate(SSH1_SMSG_X11_OPEN);
214 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
215 translate(SSH1_MSG_PORT_OPEN);
216 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
217 translate(SSH1_SMSG_AGENT_OPEN);
218 translate(SSH1_MSG_IGNORE);
219 translate(SSH1_CMSG_EXIT_CONFIRMATION);
220 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
221 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
222 translate(SSH1_MSG_DEBUG);
223 translate(SSH1_CMSG_REQUEST_COMPRESSION);
224 translate(SSH1_CMSG_AUTH_TIS);
225 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
226 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
227 translate(SSH1_CMSG_AUTH_CCARD);
228 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
232 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
234 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
235 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
236 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
237 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
238 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
239 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
240 translate(SSH2_MSG_DISCONNECT);
241 translate(SSH2_MSG_IGNORE);
242 translate(SSH2_MSG_UNIMPLEMENTED);
243 translate(SSH2_MSG_DEBUG);
244 translate(SSH2_MSG_SERVICE_REQUEST);
245 translate(SSH2_MSG_SERVICE_ACCEPT);
246 translate(SSH2_MSG_KEXINIT);
247 translate(SSH2_MSG_NEWKEYS);
248 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
249 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
250 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
251 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
252 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
253 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
254 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
255 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
256 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
257 translate(SSH2_MSG_USERAUTH_REQUEST);
258 translate(SSH2_MSG_USERAUTH_FAILURE);
259 translate(SSH2_MSG_USERAUTH_SUCCESS);
260 translate(SSH2_MSG_USERAUTH_BANNER);
261 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
262 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
263 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
264 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
265 translate(SSH2_MSG_GLOBAL_REQUEST);
266 translate(SSH2_MSG_REQUEST_SUCCESS);
267 translate(SSH2_MSG_REQUEST_FAILURE);
268 translate(SSH2_MSG_CHANNEL_OPEN);
269 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
270 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
271 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
272 translate(SSH2_MSG_CHANNEL_DATA);
273 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
274 translate(SSH2_MSG_CHANNEL_EOF);
275 translate(SSH2_MSG_CHANNEL_CLOSE);
276 translate(SSH2_MSG_CHANNEL_REQUEST);
277 translate(SSH2_MSG_CHANNEL_SUCCESS);
278 translate(SSH2_MSG_CHANNEL_FAILURE);
284 /* Enumeration values for fields in SSH-1 packets */
286 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
290 * Coroutine mechanics for the sillier bits of the code. If these
291 * macros look impenetrable to you, you might find it helpful to
294 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
296 * which explains the theory behind these macros.
298 * In particular, if you are getting `case expression not constant'
299 * errors when building with MS Visual Studio, this is because MS's
300 * Edit and Continue debugging feature causes their compiler to
301 * violate ANSI C. To disable Edit and Continue debugging:
303 * - right-click ssh.c in the FileView
305 * - select the C/C++ tab and the General category
306 * - under `Debug info:', select anything _other_ than `Program
307 * Database for Edit and Continue'.
309 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
310 #define crBeginState crBegin(s->crLine)
311 #define crStateP(t, v) \
313 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
315 #define crState(t) crStateP(t, ssh->t)
316 #define crFinish(z) } *crLine = 0; return (z); }
317 #define crFinishV } *crLine = 0; return; }
318 #define crFinishFree(z) } sfree(s); return (z); }
319 #define crFinishFreeV } sfree(s); return; }
320 #define crReturn(z) \
322 *crLine =__LINE__; return (z); case __LINE__:;\
326 *crLine=__LINE__; return; case __LINE__:;\
328 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
329 #define crStopV do{ *crLine = 0; return; }while(0)
330 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
331 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
335 static struct Packet *ssh1_pkt_init(int pkt_type);
336 static struct Packet *ssh2_pkt_init(int pkt_type);
337 static void ssh_pkt_ensure(struct Packet *, int length);
338 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
339 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
340 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
341 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
342 static void ssh_pkt_addstring_start(struct Packet *);
343 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
344 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
345 static void ssh_pkt_addstring(struct Packet *, const char *data);
346 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
347 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
348 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
349 static int ssh2_pkt_construct(Ssh, struct Packet *);
350 static void ssh2_pkt_send(Ssh, struct Packet *);
351 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
352 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
353 struct Packet *pktin);
354 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
355 struct Packet *pktin);
356 static void ssh2_channel_check_close(struct ssh_channel *c);
357 static void ssh_channel_destroy(struct ssh_channel *c);
360 * Buffer management constants. There are several of these for
361 * various different purposes:
363 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
364 * on a local data stream before we throttle the whole SSH
365 * connection (in SSH-1 only). Throttling the whole connection is
366 * pretty drastic so we set this high in the hope it won't
369 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
370 * on the SSH connection itself before we defensively throttle
371 * _all_ local data streams. This is pretty drastic too (though
372 * thankfully unlikely in SSH-2 since the window mechanism should
373 * ensure that the server never has any need to throttle its end
374 * of the connection), so we set this high as well.
376 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
379 * - OUR_V2_BIGWIN is the window size we advertise for the only
380 * channel in a simple connection. It must be <= INT_MAX.
382 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
383 * to the remote side. This actually has nothing to do with the
384 * size of the _packet_, but is instead a limit on the amount
385 * of data we're willing to receive in a single SSH2 channel
388 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
389 * _packet_ we're prepared to cope with. It must be a multiple
390 * of the cipher block size, and must be at least 35000.
393 #define SSH1_BUFFER_LIMIT 32768
394 #define SSH_MAX_BACKLOG 32768
395 #define OUR_V2_WINSIZE 16384
396 #define OUR_V2_BIGWIN 0x7fffffff
397 #define OUR_V2_MAXPKT 0x4000UL
398 #define OUR_V2_PACKETLIMIT 0x9000UL
400 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
402 const static struct ssh_mac *macs[] = {
403 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
405 const static struct ssh_mac *buggymacs[] = {
406 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
409 static void *ssh_comp_none_init(void)
413 static void ssh_comp_none_cleanup(void *handle)
416 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
417 unsigned char **outblock, int *outlen)
421 static int ssh_comp_none_disable(void *handle)
425 const static struct ssh_compress ssh_comp_none = {
427 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
428 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
429 ssh_comp_none_disable, NULL
431 extern const struct ssh_compress ssh_zlib;
432 const static struct ssh_compress *compressions[] = {
433 &ssh_zlib, &ssh_comp_none
436 enum { /* channel types */
441 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
443 * CHAN_SHARING indicates a channel which is tracked here on
444 * behalf of a connection-sharing downstream. We do almost nothing
445 * with these channels ourselves: all messages relating to them
446 * get thrown straight to sshshare.c and passed on almost
447 * unmodified to downstream.
451 * CHAN_ZOMBIE is used to indicate a channel for which we've
452 * already destroyed the local data source: for instance, if a
453 * forwarded port experiences a socket error on the local side, we
454 * immediately destroy its local socket and turn the SSH channel
460 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
461 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
462 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
465 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
468 struct outstanding_channel_request {
469 cchandler_fn_t handler;
471 struct outstanding_channel_request *next;
475 * 2-3-4 tree storing channels.
478 Ssh ssh; /* pointer back to main context */
479 unsigned remoteid, localid;
481 /* True if we opened this channel but server hasn't confirmed. */
484 * In SSH-1, this value contains four bits:
486 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
487 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
488 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
489 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
491 * A channel is completely finished with when all four bits are set.
493 * In SSH-2, the four bits mean:
495 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
496 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
497 * 4 We have received SSH2_MSG_CHANNEL_EOF.
498 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
500 * A channel is completely finished with when we have both sent
501 * and received CLOSE.
503 * The symbolic constants below use the SSH-2 terminology, which
504 * is a bit confusing in SSH-1, but we have to use _something_.
506 #define CLOSES_SENT_EOF 1
507 #define CLOSES_SENT_CLOSE 2
508 #define CLOSES_RCVD_EOF 4
509 #define CLOSES_RCVD_CLOSE 8
513 * This flag indicates that an EOF is pending on the outgoing side
514 * of the channel: that is, wherever we're getting the data for
515 * this channel has sent us some data followed by EOF. We can't
516 * actually send the EOF until we've finished sending the data, so
517 * we set this flag instead to remind us to do so once our buffer
523 * True if this channel is causing the underlying connection to be
528 struct ssh2_data_channel {
530 unsigned remwindow, remmaxpkt;
531 /* locwindow is signed so we can cope with excess data. */
532 int locwindow, locmaxwin;
534 * remlocwin is the amount of local window that we think
535 * the remote end had available to it after it sent the
536 * last data packet or window adjust ack.
540 * These store the list of channel requests that haven't
543 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
544 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
548 struct ssh_agent_channel {
549 unsigned char *message;
550 unsigned char msglen[4];
551 unsigned lensofar, totallen;
552 int outstanding_requests;
554 struct ssh_x11_channel {
555 struct X11Connection *xconn;
558 struct ssh_pfd_channel {
559 struct PortForwarding *pf;
561 struct ssh_sharing_channel {
568 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
569 * use this structure in different ways, reflecting SSH-2's
570 * altogether saner approach to port forwarding.
572 * In SSH-1, you arrange a remote forwarding by sending the server
573 * the remote port number, and the local destination host:port.
574 * When a connection comes in, the server sends you back that
575 * host:port pair, and you connect to it. This is a ready-made
576 * security hole if you're not on the ball: a malicious server
577 * could send you back _any_ host:port pair, so if you trustingly
578 * connect to the address it gives you then you've just opened the
579 * entire inside of your corporate network just by connecting
580 * through it to a dodgy SSH server. Hence, we must store a list of
581 * host:port pairs we _are_ trying to forward to, and reject a
582 * connection request from the server if it's not in the list.
584 * In SSH-2, each side of the connection minds its own business and
585 * doesn't send unnecessary information to the other. You arrange a
586 * remote forwarding by sending the server just the remote port
587 * number. When a connection comes in, the server tells you which
588 * of its ports was connected to; and _you_ have to remember what
589 * local host:port pair went with that port number.
591 * Hence, in SSH-1 this structure is indexed by destination
592 * host:port pair, whereas in SSH-2 it is indexed by source port.
594 struct ssh_portfwd; /* forward declaration */
596 struct ssh_rportfwd {
597 unsigned sport, dport;
601 struct ssh_portfwd *pfrec;
604 static void free_rportfwd(struct ssh_rportfwd *pf)
607 sfree(pf->sportdesc);
615 * Separately to the rportfwd tree (which is for looking up port
616 * open requests from the server), a tree of _these_ structures is
617 * used to keep track of all the currently open port forwardings,
618 * so that we can reconfigure in mid-session if the user requests
622 enum { DESTROY, KEEP, CREATE } status;
624 unsigned sport, dport;
627 struct ssh_rportfwd *remote;
629 struct PortListener *local;
631 #define free_portfwd(pf) ( \
632 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
633 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
636 long length; /* length of packet: see below */
637 long forcepad; /* SSH-2: force padding to at least this length */
638 int type; /* only used for incoming packets */
639 unsigned long sequence; /* SSH-2 incoming sequence number */
640 unsigned char *data; /* allocated storage */
641 unsigned char *body; /* offset of payload within `data' */
642 long savedpos; /* dual-purpose saved packet position: see below */
643 long maxlen; /* amount of storage allocated for `data' */
644 long encrypted_len; /* for SSH-2 total-size counting */
647 * A note on the 'length' and 'savedpos' fields above.
649 * Incoming packets are set up so that pkt->length is measured
650 * relative to pkt->body, which itself points to a few bytes after
651 * pkt->data (skipping some uninteresting header fields including
652 * the packet type code). The ssh_pkt_get* functions all expect
653 * this setup, and they also use pkt->savedpos to indicate how far
654 * through the packet being decoded they've got - and that, too,
655 * is an offset from pkt->body rather than pkt->data.
657 * During construction of an outgoing packet, however, pkt->length
658 * is measured relative to the base pointer pkt->data, and
659 * pkt->body is not really used for anything until the packet is
660 * ready for sending. In this mode, pkt->savedpos is reused as a
661 * temporary variable by the addstring functions, which write out
662 * a string length field and then keep going back and updating it
663 * as more data is appended to the subsequent string data field;
664 * pkt->savedpos stores the offset (again relative to pkt->data)
665 * of the start of the string data field.
668 /* Extra metadata used in SSH packet logging mode, allowing us to
669 * log in the packet header line that the packet came from a
670 * connection-sharing downstream and what if anything unusual was
671 * done to it. The additional_log_text field is expected to be a
672 * static string - it will not be freed. */
673 unsigned downstream_id;
674 const char *additional_log_text;
677 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
678 struct Packet *pktin);
679 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
680 struct Packet *pktin);
681 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
682 struct Packet *pktin);
683 static void ssh1_protocol_setup(Ssh ssh);
684 static void ssh2_protocol_setup(Ssh ssh);
685 static void ssh2_bare_connection_protocol_setup(Ssh ssh);
686 static void ssh_size(void *handle, int width, int height);
687 static void ssh_special(void *handle, Telnet_Special);
688 static int ssh2_try_send(struct ssh_channel *c);
689 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
690 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
691 static void ssh2_set_window(struct ssh_channel *c, int newwin);
692 static int ssh_sendbuffer(void *handle);
693 static int ssh_do_close(Ssh ssh, int notify_exit);
694 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
695 static int ssh2_pkt_getbool(struct Packet *pkt);
696 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
697 static void ssh2_timer(void *ctx, unsigned long now);
698 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
699 struct Packet *pktin);
700 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
702 struct rdpkt1_state_tag {
703 long len, pad, biglen, to_read;
704 unsigned long realcrc, gotcrc;
708 struct Packet *pktin;
711 struct rdpkt2_state_tag {
712 long len, pad, payload, packetlen, maclen;
715 unsigned long incoming_sequence;
716 struct Packet *pktin;
719 struct rdpkt2_bare_state_tag {
723 unsigned long incoming_sequence;
724 struct Packet *pktin;
727 struct queued_handler;
728 struct queued_handler {
730 chandler_fn_t handler;
732 struct queued_handler *next;
736 const struct plug_function_table *fn;
737 /* the above field _must_ be first in the structure */
747 unsigned char session_key[32];
749 int v1_remote_protoflags;
750 int v1_local_protoflags;
751 int agentfwd_enabled;
754 const struct ssh_cipher *cipher;
757 const struct ssh2_cipher *cscipher, *sccipher;
758 void *cs_cipher_ctx, *sc_cipher_ctx;
759 const struct ssh_mac *csmac, *scmac;
760 void *cs_mac_ctx, *sc_mac_ctx;
761 const struct ssh_compress *cscomp, *sccomp;
762 void *cs_comp_ctx, *sc_comp_ctx;
763 const struct ssh_kex *kex;
764 const struct ssh_signkey *hostkey;
765 char *hostkey_str; /* string representation, for easy checking in rekeys */
766 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
767 int v2_session_id_len;
771 int attempting_connshare;
777 int echoing, editing;
781 int ospeed, ispeed; /* temporaries */
782 int term_width, term_height;
784 tree234 *channels; /* indexed by local id */
785 struct ssh_channel *mainchan; /* primary session channel */
786 int ncmode; /* is primary channel direct-tcpip? */
791 tree234 *rportfwds, *portfwds;
795 SSH_STATE_BEFORE_SIZE,
801 int size_needed, eof_needed;
802 int sent_console_eof;
803 int got_pty; /* affects EOF behaviour on main channel */
805 struct Packet **queue;
806 int queuelen, queuesize;
808 unsigned char *deferred_send_data;
809 int deferred_len, deferred_size;
812 * Gross hack: pscp will try to start SFTP but fall back to
813 * scp1 if that fails. This variable is the means by which
814 * scp.c can reach into the SSH code and find out which one it
819 bufchain banner; /* accumulates banners during do_ssh2_authconn */
824 struct X11Display *x11disp;
825 struct X11FakeAuth *x11auth;
826 tree234 *x11authtree;
829 int conn_throttle_count;
832 int v1_stdout_throttling;
833 unsigned long v2_outgoing_sequence;
835 int ssh1_rdpkt_crstate;
836 int ssh2_rdpkt_crstate;
837 int ssh2_bare_rdpkt_crstate;
838 int ssh_gotdata_crstate;
839 int do_ssh1_connection_crstate;
841 void *do_ssh_init_state;
842 void *do_ssh1_login_state;
843 void *do_ssh2_transport_state;
844 void *do_ssh2_authconn_state;
845 void *do_ssh_connection_init_state;
847 struct rdpkt1_state_tag rdpkt1_state;
848 struct rdpkt2_state_tag rdpkt2_state;
849 struct rdpkt2_bare_state_tag rdpkt2_bare_state;
851 /* SSH-1 and SSH-2 use this for different things, but both use it */
852 int protocol_initial_phase_done;
854 void (*protocol) (Ssh ssh, void *vin, int inlen,
856 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
857 int (*do_ssh_init)(Ssh ssh, unsigned char c);
860 * We maintain our own copy of a Conf structure here. That way,
861 * when we're passed a new one for reconfiguration, we can check
862 * the differences and potentially reconfigure port forwardings
863 * etc in mid-session.
868 * Values cached out of conf so as to avoid the tree234 lookup
869 * cost every time they're used.
874 * Dynamically allocated username string created during SSH
875 * login. Stored in here rather than in the coroutine state so
876 * that it'll be reliably freed if we shut down the SSH session
877 * at some unexpected moment.
882 * Used to transfer data back from async callbacks.
884 void *agent_response;
885 int agent_response_len;
889 * The SSH connection can be set as `frozen', meaning we are
890 * not currently accepting incoming data from the network. This
891 * is slightly more serious than setting the _socket_ as
892 * frozen, because we may already have had data passed to us
893 * from the network which we need to delay processing until
894 * after the freeze is lifted, so we also need a bufchain to
898 bufchain queued_incoming_data;
901 * Dispatch table for packet types that we may have to deal
904 handler_fn_t packet_dispatch[256];
907 * Queues of one-off handler functions for success/failure
908 * indications from a request.
910 struct queued_handler *qhead, *qtail;
911 handler_fn_t q_saved_handler1, q_saved_handler2;
914 * This module deals with sending keepalives.
919 * Track incoming and outgoing data sizes and time, for
922 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
923 unsigned long max_data_size;
925 unsigned long next_rekey, last_rekey;
926 char *deferred_rekey_reason; /* points to STATIC string; don't free */
929 * Fully qualified host name, which we need if doing GSSAPI.
935 * GSSAPI libraries for this session.
937 struct ssh_gss_liblist *gsslibs;
941 #define logevent(s) logevent(ssh->frontend, s)
943 /* logevent, only printf-formatted. */
944 static void logeventf(Ssh ssh, const char *fmt, ...)
950 buf = dupvprintf(fmt, ap);
956 static void bomb_out(Ssh ssh, char *text)
958 ssh_do_close(ssh, FALSE);
960 connection_fatal(ssh->frontend, "%s", text);
964 #define bombout(msg) bomb_out(ssh, dupprintf msg)
966 /* Helper function for common bits of parsing ttymodes. */
967 static void parse_ttymodes(Ssh ssh,
968 void (*do_mode)(void *data, char *mode, char *val),
973 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
975 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
977 * val[0] is either 'V', indicating that an explicit value
978 * follows it, or 'A' indicating that we should pass the
979 * value through from the local environment via get_ttymode.
982 val = get_ttymode(ssh->frontend, key);
984 do_mode(data, key, val);
988 do_mode(data, key, val + 1); /* skip the 'V' */
992 static int ssh_channelcmp(void *av, void *bv)
994 struct ssh_channel *a = (struct ssh_channel *) av;
995 struct ssh_channel *b = (struct ssh_channel *) bv;
996 if (a->localid < b->localid)
998 if (a->localid > b->localid)
1002 static int ssh_channelfind(void *av, void *bv)
1004 unsigned *a = (unsigned *) av;
1005 struct ssh_channel *b = (struct ssh_channel *) bv;
1006 if (*a < b->localid)
1008 if (*a > b->localid)
1013 static int ssh_rportcmp_ssh1(void *av, void *bv)
1015 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1016 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1018 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1019 return i < 0 ? -1 : +1;
1020 if (a->dport > b->dport)
1022 if (a->dport < b->dport)
1027 static int ssh_rportcmp_ssh2(void *av, void *bv)
1029 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1030 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1032 if ( (i = strcmp(a->shost, b->shost)) != 0)
1033 return i < 0 ? -1 : +1;
1034 if (a->sport > b->sport)
1036 if (a->sport < b->sport)
1042 * Special form of strcmp which can cope with NULL inputs. NULL is
1043 * defined to sort before even the empty string.
1045 static int nullstrcmp(const char *a, const char *b)
1047 if (a == NULL && b == NULL)
1053 return strcmp(a, b);
1056 static int ssh_portcmp(void *av, void *bv)
1058 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1059 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1061 if (a->type > b->type)
1063 if (a->type < b->type)
1065 if (a->addressfamily > b->addressfamily)
1067 if (a->addressfamily < b->addressfamily)
1069 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1070 return i < 0 ? -1 : +1;
1071 if (a->sport > b->sport)
1073 if (a->sport < b->sport)
1075 if (a->type != 'D') {
1076 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1077 return i < 0 ? -1 : +1;
1078 if (a->dport > b->dport)
1080 if (a->dport < b->dport)
1086 static int alloc_channel_id(Ssh ssh)
1088 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1089 unsigned low, high, mid;
1091 struct ssh_channel *c;
1094 * First-fit allocation of channel numbers: always pick the
1095 * lowest unused one. To do this, binary-search using the
1096 * counted B-tree to find the largest channel ID which is in a
1097 * contiguous sequence from the beginning. (Precisely
1098 * everything in that sequence must have ID equal to its tree
1099 * index plus CHANNEL_NUMBER_OFFSET.)
1101 tsize = count234(ssh->channels);
1105 while (high - low > 1) {
1106 mid = (high + low) / 2;
1107 c = index234(ssh->channels, mid);
1108 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1109 low = mid; /* this one is fine */
1111 high = mid; /* this one is past it */
1114 * Now low points to either -1, or the tree index of the
1115 * largest ID in the initial sequence.
1118 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1119 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1121 return low + 1 + CHANNEL_NUMBER_OFFSET;
1124 static void c_write_stderr(int trusted, const char *buf, int len)
1127 for (i = 0; i < len; i++)
1128 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1129 fputc(buf[i], stderr);
1132 static void c_write(Ssh ssh, const char *buf, int len)
1134 if (flags & FLAG_STDERR)
1135 c_write_stderr(1, buf, len);
1137 from_backend(ssh->frontend, 1, buf, len);
1140 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1142 if (flags & FLAG_STDERR)
1143 c_write_stderr(0, buf, len);
1145 from_backend_untrusted(ssh->frontend, buf, len);
1148 static void c_write_str(Ssh ssh, const char *buf)
1150 c_write(ssh, buf, strlen(buf));
1153 static void ssh_free_packet(struct Packet *pkt)
1158 static struct Packet *ssh_new_packet(void)
1160 struct Packet *pkt = snew(struct Packet);
1162 pkt->body = pkt->data = NULL;
1168 static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1171 struct logblank_t blanks[4];
1177 if (ssh->logomitdata &&
1178 (pkt->type == SSH1_SMSG_STDOUT_DATA ||
1179 pkt->type == SSH1_SMSG_STDERR_DATA ||
1180 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1181 /* "Session data" packets - omit the data string. */
1182 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1183 ssh_pkt_getuint32(pkt); /* skip channel id */
1184 blanks[nblanks].offset = pkt->savedpos + 4;
1185 blanks[nblanks].type = PKTLOG_OMIT;
1186 ssh_pkt_getstring(pkt, &str, &slen);
1188 blanks[nblanks].len = slen;
1192 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1193 ssh1_pkt_type(pkt->type),
1194 pkt->body, pkt->length, nblanks, blanks, NULL,
1198 static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1201 struct logblank_t blanks[4];
1206 * For outgoing packets, pkt->length represents the length of the
1207 * whole packet starting at pkt->data (including some header), and
1208 * pkt->body refers to the point within that where the log-worthy
1209 * payload begins. However, incoming packets expect pkt->length to
1210 * represent only the payload length (that is, it's measured from
1211 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1212 * packet to conform to the incoming-packet semantics, so that we
1213 * can analyse it with the ssh_pkt_get functions.
1215 pkt->length -= (pkt->body - pkt->data);
1218 if (ssh->logomitdata &&
1219 (pkt->type == SSH1_CMSG_STDIN_DATA ||
1220 pkt->type == SSH1_MSG_CHANNEL_DATA)) {
1221 /* "Session data" packets - omit the data string. */
1222 if (pkt->type == SSH1_MSG_CHANNEL_DATA)
1223 ssh_pkt_getuint32(pkt); /* skip channel id */
1224 blanks[nblanks].offset = pkt->savedpos + 4;
1225 blanks[nblanks].type = PKTLOG_OMIT;
1226 ssh_pkt_getstring(pkt, &str, &slen);
1228 blanks[nblanks].len = slen;
1233 if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD ||
1234 pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE ||
1235 pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) &&
1236 conf_get_int(ssh->conf, CONF_logomitpass)) {
1237 /* If this is a password or similar packet, blank the password(s). */
1238 blanks[nblanks].offset = 0;
1239 blanks[nblanks].len = pkt->length;
1240 blanks[nblanks].type = PKTLOG_BLANK;
1242 } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING &&
1243 conf_get_int(ssh->conf, CONF_logomitpass)) {
1245 * If this is an X forwarding request packet, blank the fake
1248 * Note that while we blank the X authentication data here, we
1249 * don't take any special action to blank the start of an X11
1250 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1251 * an X connection without having session blanking enabled is
1252 * likely to leak your cookie into the log.
1255 ssh_pkt_getstring(pkt, &str, &slen);
1256 blanks[nblanks].offset = pkt->savedpos;
1257 blanks[nblanks].type = PKTLOG_BLANK;
1258 ssh_pkt_getstring(pkt, &str, &slen);
1260 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1265 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1266 ssh1_pkt_type(pkt->data[12]),
1267 pkt->body, pkt->length,
1268 nblanks, blanks, NULL, 0, NULL);
1271 * Undo the above adjustment of pkt->length, to put the packet
1272 * back in the state we found it.
1274 pkt->length += (pkt->body - pkt->data);
1278 * Collect incoming data in the incoming packet buffer.
1279 * Decipher and verify the packet when it is completely read.
1280 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1281 * Update the *data and *datalen variables.
1282 * Return a Packet structure when a packet is completed.
1284 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1286 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1288 crBegin(ssh->ssh1_rdpkt_crstate);
1290 st->pktin = ssh_new_packet();
1292 st->pktin->type = 0;
1293 st->pktin->length = 0;
1295 for (st->i = st->len = 0; st->i < 4; st->i++) {
1296 while ((*datalen) == 0)
1298 st->len = (st->len << 8) + **data;
1299 (*data)++, (*datalen)--;
1302 st->pad = 8 - (st->len % 8);
1303 st->biglen = st->len + st->pad;
1304 st->pktin->length = st->len - 5;
1306 if (st->biglen < 0) {
1307 bombout(("Extremely large packet length from server suggests"
1308 " data stream corruption"));
1309 ssh_free_packet(st->pktin);
1313 st->pktin->maxlen = st->biglen;
1314 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1316 st->to_read = st->biglen;
1317 st->p = st->pktin->data;
1318 while (st->to_read > 0) {
1319 st->chunk = st->to_read;
1320 while ((*datalen) == 0)
1322 if (st->chunk > (*datalen))
1323 st->chunk = (*datalen);
1324 memcpy(st->p, *data, st->chunk);
1326 *datalen -= st->chunk;
1328 st->to_read -= st->chunk;
1331 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1332 st->biglen, NULL)) {
1333 bombout(("Network attack (CRC compensation) detected!"));
1334 ssh_free_packet(st->pktin);
1339 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1341 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1342 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1343 if (st->gotcrc != st->realcrc) {
1344 bombout(("Incorrect CRC received on packet"));
1345 ssh_free_packet(st->pktin);
1349 st->pktin->body = st->pktin->data + st->pad + 1;
1351 if (ssh->v1_compressing) {
1352 unsigned char *decompblk;
1354 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1355 st->pktin->body - 1, st->pktin->length + 1,
1356 &decompblk, &decomplen)) {
1357 bombout(("Zlib decompression encountered invalid data"));
1358 ssh_free_packet(st->pktin);
1362 if (st->pktin->maxlen < st->pad + decomplen) {
1363 st->pktin->maxlen = st->pad + decomplen;
1364 st->pktin->data = sresize(st->pktin->data,
1365 st->pktin->maxlen + APIEXTRA,
1367 st->pktin->body = st->pktin->data + st->pad + 1;
1370 memcpy(st->pktin->body - 1, decompblk, decomplen);
1372 st->pktin->length = decomplen - 1;
1375 st->pktin->type = st->pktin->body[-1];
1378 * Now pktin->body and pktin->length identify the semantic content
1379 * of the packet, excluding the initial type byte.
1383 ssh1_log_incoming_packet(ssh, st->pktin);
1385 st->pktin->savedpos = 0;
1387 crFinish(st->pktin);
1390 static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt)
1393 struct logblank_t blanks[4];
1399 if (ssh->logomitdata &&
1400 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1401 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1402 /* "Session data" packets - omit the data string. */
1403 ssh_pkt_getuint32(pkt); /* skip channel id */
1404 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1405 ssh_pkt_getuint32(pkt); /* skip extended data type */
1406 blanks[nblanks].offset = pkt->savedpos + 4;
1407 blanks[nblanks].type = PKTLOG_OMIT;
1408 ssh_pkt_getstring(pkt, &str, &slen);
1410 blanks[nblanks].len = slen;
1415 log_packet(ssh->logctx, PKT_INCOMING, pkt->type,
1416 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type),
1417 pkt->body, pkt->length, nblanks, blanks, &pkt->sequence,
1421 static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt)
1424 struct logblank_t blanks[4];
1429 * For outgoing packets, pkt->length represents the length of the
1430 * whole packet starting at pkt->data (including some header), and
1431 * pkt->body refers to the point within that where the log-worthy
1432 * payload begins. However, incoming packets expect pkt->length to
1433 * represent only the payload length (that is, it's measured from
1434 * pkt->body not from pkt->data). Temporarily adjust our outgoing
1435 * packet to conform to the incoming-packet semantics, so that we
1436 * can analyse it with the ssh_pkt_get functions.
1438 pkt->length -= (pkt->body - pkt->data);
1441 if (ssh->logomitdata &&
1442 (pkt->type == SSH2_MSG_CHANNEL_DATA ||
1443 pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) {
1444 /* "Session data" packets - omit the data string. */
1445 ssh_pkt_getuint32(pkt); /* skip channel id */
1446 if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)
1447 ssh_pkt_getuint32(pkt); /* skip extended data type */
1448 blanks[nblanks].offset = pkt->savedpos + 4;
1449 blanks[nblanks].type = PKTLOG_OMIT;
1450 ssh_pkt_getstring(pkt, &str, &slen);
1452 blanks[nblanks].len = slen;
1457 if (pkt->type == SSH2_MSG_USERAUTH_REQUEST &&
1458 conf_get_int(ssh->conf, CONF_logomitpass)) {
1459 /* If this is a password packet, blank the password(s). */
1461 ssh_pkt_getstring(pkt, &str, &slen);
1462 ssh_pkt_getstring(pkt, &str, &slen);
1463 ssh_pkt_getstring(pkt, &str, &slen);
1464 if (slen == 8 && !memcmp(str, "password", 8)) {
1465 ssh2_pkt_getbool(pkt);
1466 /* Blank the password field. */
1467 blanks[nblanks].offset = pkt->savedpos;
1468 blanks[nblanks].type = PKTLOG_BLANK;
1469 ssh_pkt_getstring(pkt, &str, &slen);
1471 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1473 /* If there's another password field beyond it (change of
1474 * password), blank that too. */
1475 ssh_pkt_getstring(pkt, &str, &slen);
1477 blanks[nblanks-1].len =
1478 pkt->savedpos - blanks[nblanks].offset;
1481 } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER &&
1482 pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE &&
1483 conf_get_int(ssh->conf, CONF_logomitpass)) {
1484 /* If this is a keyboard-interactive response packet, blank
1487 ssh_pkt_getuint32(pkt);
1488 blanks[nblanks].offset = pkt->savedpos;
1489 blanks[nblanks].type = PKTLOG_BLANK;
1491 ssh_pkt_getstring(pkt, &str, &slen);
1495 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1497 } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST &&
1498 conf_get_int(ssh->conf, CONF_logomitpass)) {
1500 * If this is an X forwarding request packet, blank the fake
1503 * Note that while we blank the X authentication data here, we
1504 * don't take any special action to blank the start of an X11
1505 * channel, so using MIT-MAGIC-COOKIE-1 and actually opening
1506 * an X connection without having session blanking enabled is
1507 * likely to leak your cookie into the log.
1510 ssh_pkt_getuint32(pkt);
1511 ssh_pkt_getstring(pkt, &str, &slen);
1512 if (slen == 7 && !memcmp(str, "x11-req", 0)) {
1513 ssh2_pkt_getbool(pkt);
1514 ssh2_pkt_getbool(pkt);
1515 ssh_pkt_getstring(pkt, &str, &slen);
1516 blanks[nblanks].offset = pkt->savedpos;
1517 blanks[nblanks].type = PKTLOG_BLANK;
1518 ssh_pkt_getstring(pkt, &str, &slen);
1520 blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset;
1526 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1527 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1528 pkt->body, pkt->length, nblanks, blanks,
1529 &ssh->v2_outgoing_sequence,
1530 pkt->downstream_id, pkt->additional_log_text);
1533 * Undo the above adjustment of pkt->length, to put the packet
1534 * back in the state we found it.
1536 pkt->length += (pkt->body - pkt->data);
1539 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1541 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1543 crBegin(ssh->ssh2_rdpkt_crstate);
1545 st->pktin = ssh_new_packet();
1547 st->pktin->type = 0;
1548 st->pktin->length = 0;
1550 st->cipherblk = ssh->sccipher->blksize;
1553 if (st->cipherblk < 8)
1555 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1557 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1560 * When dealing with a CBC-mode cipher, we want to avoid the
1561 * possibility of an attacker's tweaking the ciphertext stream
1562 * so as to cause us to feed the same block to the block
1563 * cipher more than once and thus leak information
1564 * (VU#958563). The way we do this is not to take any
1565 * decisions on the basis of anything we've decrypted until
1566 * we've verified it with a MAC. That includes the packet
1567 * length, so we just read data and check the MAC repeatedly,
1568 * and when the MAC passes, see if the length we've got is
1572 /* May as well allocate the whole lot now. */
1573 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1576 /* Read an amount corresponding to the MAC. */
1577 for (st->i = 0; st->i < st->maclen; st->i++) {
1578 while ((*datalen) == 0)
1580 st->pktin->data[st->i] = *(*data)++;
1586 unsigned char seq[4];
1587 ssh->scmac->start(ssh->sc_mac_ctx);
1588 PUT_32BIT(seq, st->incoming_sequence);
1589 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1592 for (;;) { /* Once around this loop per cipher block. */
1593 /* Read another cipher-block's worth, and tack it onto the end. */
1594 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1595 while ((*datalen) == 0)
1597 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1600 /* Decrypt one more block (a little further back in the stream). */
1601 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1602 st->pktin->data + st->packetlen,
1604 /* Feed that block to the MAC. */
1605 ssh->scmac->bytes(ssh->sc_mac_ctx,
1606 st->pktin->data + st->packetlen, st->cipherblk);
1607 st->packetlen += st->cipherblk;
1608 /* See if that gives us a valid packet. */
1609 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1610 st->pktin->data + st->packetlen) &&
1611 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1614 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1615 bombout(("No valid incoming packet found"));
1616 ssh_free_packet(st->pktin);
1620 st->pktin->maxlen = st->packetlen + st->maclen;
1621 st->pktin->data = sresize(st->pktin->data,
1622 st->pktin->maxlen + APIEXTRA,
1625 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1628 * Acquire and decrypt the first block of the packet. This will
1629 * contain the length and padding details.
1631 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1632 while ((*datalen) == 0)
1634 st->pktin->data[st->i] = *(*data)++;
1639 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1640 st->pktin->data, st->cipherblk);
1643 * Now get the length figure.
1645 st->len = toint(GET_32BIT(st->pktin->data));
1648 * _Completely_ silly lengths should be stomped on before they
1649 * do us any more damage.
1651 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1652 (st->len + 4) % st->cipherblk != 0) {
1653 bombout(("Incoming packet was garbled on decryption"));
1654 ssh_free_packet(st->pktin);
1659 * So now we can work out the total packet length.
1661 st->packetlen = st->len + 4;
1664 * Allocate memory for the rest of the packet.
1666 st->pktin->maxlen = st->packetlen + st->maclen;
1667 st->pktin->data = sresize(st->pktin->data,
1668 st->pktin->maxlen + APIEXTRA,
1672 * Read and decrypt the remainder of the packet.
1674 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1676 while ((*datalen) == 0)
1678 st->pktin->data[st->i] = *(*data)++;
1681 /* Decrypt everything _except_ the MAC. */
1683 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1684 st->pktin->data + st->cipherblk,
1685 st->packetlen - st->cipherblk);
1691 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1692 st->len + 4, st->incoming_sequence)) {
1693 bombout(("Incorrect MAC received on packet"));
1694 ssh_free_packet(st->pktin);
1698 /* Get and sanity-check the amount of random padding. */
1699 st->pad = st->pktin->data[4];
1700 if (st->pad < 4 || st->len - st->pad < 1) {
1701 bombout(("Invalid padding length on received packet"));
1702 ssh_free_packet(st->pktin);
1706 * This enables us to deduce the payload length.
1708 st->payload = st->len - st->pad - 1;
1710 st->pktin->length = st->payload + 5;
1711 st->pktin->encrypted_len = st->packetlen;
1713 st->pktin->sequence = st->incoming_sequence++;
1715 st->pktin->length = st->packetlen - st->pad;
1716 assert(st->pktin->length >= 0);
1719 * Decompress packet payload.
1722 unsigned char *newpayload;
1725 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1726 st->pktin->data + 5, st->pktin->length - 5,
1727 &newpayload, &newlen)) {
1728 if (st->pktin->maxlen < newlen + 5) {
1729 st->pktin->maxlen = newlen + 5;
1730 st->pktin->data = sresize(st->pktin->data,
1731 st->pktin->maxlen + APIEXTRA,
1734 st->pktin->length = 5 + newlen;
1735 memcpy(st->pktin->data + 5, newpayload, newlen);
1741 * pktin->body and pktin->length should identify the semantic
1742 * content of the packet, excluding the initial type byte.
1744 st->pktin->type = st->pktin->data[5];
1745 st->pktin->body = st->pktin->data + 6;
1746 st->pktin->length -= 6;
1747 assert(st->pktin->length >= 0); /* one last double-check */
1750 ssh2_log_incoming_packet(ssh, st->pktin);
1752 st->pktin->savedpos = 0;
1754 crFinish(st->pktin);
1757 static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data,
1760 struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state;
1762 crBegin(ssh->ssh2_bare_rdpkt_crstate);
1765 * Read the packet length field.
1767 for (st->i = 0; st->i < 4; st->i++) {
1768 while ((*datalen) == 0)
1770 st->length[st->i] = *(*data)++;
1774 st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length));
1775 if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) {
1776 bombout(("Invalid packet length received"));
1780 st->pktin = ssh_new_packet();
1781 st->pktin->data = snewn(st->packetlen, unsigned char);
1783 st->pktin->encrypted_len = st->packetlen;
1785 st->pktin->sequence = st->incoming_sequence++;
1788 * Read the remainder of the packet.
1790 for (st->i = 0; st->i < st->packetlen; st->i++) {
1791 while ((*datalen) == 0)
1793 st->pktin->data[st->i] = *(*data)++;
1798 * pktin->body and pktin->length should identify the semantic
1799 * content of the packet, excluding the initial type byte.
1801 st->pktin->type = st->pktin->data[0];
1802 st->pktin->body = st->pktin->data + 1;
1803 st->pktin->length = st->packetlen - 1;
1806 * Log incoming packet, possibly omitting sensitive fields.
1809 ssh2_log_incoming_packet(ssh, st->pktin);
1811 st->pktin->savedpos = 0;
1813 crFinish(st->pktin);
1816 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1818 int pad, biglen, i, pktoffs;
1822 * XXX various versions of SC (including 8.8.4) screw up the
1823 * register allocation in this function and use the same register
1824 * (D6) for len and as a temporary, with predictable results. The
1825 * following sledgehammer prevents this.
1832 ssh1_log_outgoing_packet(ssh, pkt);
1834 if (ssh->v1_compressing) {
1835 unsigned char *compblk;
1837 zlib_compress_block(ssh->cs_comp_ctx,
1838 pkt->data + 12, pkt->length - 12,
1839 &compblk, &complen);
1840 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1841 memcpy(pkt->data + 12, compblk, complen);
1843 pkt->length = complen + 12;
1846 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1848 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1849 pad = 8 - (len % 8);
1851 biglen = len + pad; /* len(padding+type+data+CRC) */
1853 for (i = pktoffs; i < 4+8; i++)
1854 pkt->data[i] = random_byte();
1855 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1856 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1857 PUT_32BIT(pkt->data + pktoffs, len);
1860 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1861 pkt->data + pktoffs + 4, biglen);
1863 if (offset_p) *offset_p = pktoffs;
1864 return biglen + 4; /* len(length+padding+type+data+CRC) */
1867 static int s_write(Ssh ssh, void *data, int len)
1870 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1871 0, NULL, NULL, 0, NULL);
1874 return sk_write(ssh->s, (char *)data, len);
1877 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1879 int len, backlog, offset;
1880 len = s_wrpkt_prepare(ssh, pkt, &offset);
1881 backlog = s_write(ssh, pkt->data + offset, len);
1882 if (backlog > SSH_MAX_BACKLOG)
1883 ssh_throttle_all(ssh, 1, backlog);
1884 ssh_free_packet(pkt);
1887 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1890 len = s_wrpkt_prepare(ssh, pkt, &offset);
1891 if (ssh->deferred_len + len > ssh->deferred_size) {
1892 ssh->deferred_size = ssh->deferred_len + len + 128;
1893 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1897 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1898 pkt->data + offset, len);
1899 ssh->deferred_len += len;
1900 ssh_free_packet(pkt);
1904 * Construct a SSH-1 packet with the specified contents.
1905 * (This all-at-once interface used to be the only one, but now SSH-1
1906 * packets can also be constructed incrementally.)
1908 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1914 pkt = ssh1_pkt_init(pkttype);
1916 while ((argtype = va_arg(ap, int)) != PKT_END) {
1917 unsigned char *argp, argchar;
1919 unsigned long argint;
1922 /* Actual fields in the packet */
1924 argint = va_arg(ap, int);
1925 ssh_pkt_adduint32(pkt, argint);
1928 argchar = (unsigned char) va_arg(ap, int);
1929 ssh_pkt_addbyte(pkt, argchar);
1932 argp = va_arg(ap, unsigned char *);
1933 arglen = va_arg(ap, int);
1934 ssh_pkt_adddata(pkt, argp, arglen);
1937 sargp = va_arg(ap, char *);
1938 ssh_pkt_addstring(pkt, sargp);
1941 bn = va_arg(ap, Bignum);
1942 ssh1_pkt_addmp(pkt, bn);
1950 static void send_packet(Ssh ssh, int pkttype, ...)
1954 va_start(ap, pkttype);
1955 pkt = construct_packet(ssh, pkttype, ap);
1960 static void defer_packet(Ssh ssh, int pkttype, ...)
1964 va_start(ap, pkttype);
1965 pkt = construct_packet(ssh, pkttype, ap);
1967 s_wrpkt_defer(ssh, pkt);
1970 static int ssh_versioncmp(char *a, char *b)
1973 unsigned long av, bv;
1975 av = strtoul(a, &ae, 10);
1976 bv = strtoul(b, &be, 10);
1978 return (av < bv ? -1 : +1);
1983 av = strtoul(ae, &ae, 10);
1984 bv = strtoul(be, &be, 10);
1986 return (av < bv ? -1 : +1);
1991 * Utility routines for putting an SSH-protocol `string' and
1992 * `uint32' into a hash state.
1994 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1996 unsigned char lenblk[4];
1997 PUT_32BIT(lenblk, len);
1998 h->bytes(s, lenblk, 4);
1999 h->bytes(s, str, len);
2002 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
2004 unsigned char intblk[4];
2005 PUT_32BIT(intblk, i);
2006 h->bytes(s, intblk, 4);
2010 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
2012 static void ssh_pkt_ensure(struct Packet *pkt, int length)
2014 if (pkt->maxlen < length) {
2015 unsigned char *body = pkt->body;
2016 int offset = body ? body - pkt->data : 0;
2017 pkt->maxlen = length + 256;
2018 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
2019 if (body) pkt->body = pkt->data + offset;
2022 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
2025 ssh_pkt_ensure(pkt, pkt->length);
2026 memcpy(pkt->data + pkt->length - len, data, len);
2028 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
2030 ssh_pkt_adddata(pkt, &byte, 1);
2032 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
2034 ssh_pkt_adddata(pkt, &value, 1);
2036 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
2039 PUT_32BIT(x, value);
2040 ssh_pkt_adddata(pkt, x, 4);
2042 static void ssh_pkt_addstring_start(struct Packet *pkt)
2044 ssh_pkt_adduint32(pkt, 0);
2045 pkt->savedpos = pkt->length;
2047 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
2049 ssh_pkt_adddata(pkt, data, strlen(data));
2050 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2052 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
2055 ssh_pkt_adddata(pkt, data, len);
2056 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
2058 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
2060 ssh_pkt_addstring_start(pkt);
2061 ssh_pkt_addstring_str(pkt, data);
2063 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
2065 int len = ssh1_bignum_length(b);
2066 unsigned char *data = snewn(len, unsigned char);
2067 (void) ssh1_write_bignum(data, b);
2068 ssh_pkt_adddata(pkt, data, len);
2071 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
2074 int i, n = (bignum_bitcount(b) + 7) / 8;
2075 p = snewn(n + 1, unsigned char);
2077 for (i = 1; i <= n; i++)
2078 p[i] = bignum_byte(b, n - i);
2080 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
2082 memmove(p, p + i, n + 1 - i);
2086 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
2090 p = ssh2_mpint_fmt(b, &len);
2091 ssh_pkt_addstring_start(pkt);
2092 ssh_pkt_addstring_data(pkt, (char *)p, len);
2096 static struct Packet *ssh1_pkt_init(int pkt_type)
2098 struct Packet *pkt = ssh_new_packet();
2099 pkt->length = 4 + 8; /* space for length + max padding */
2100 ssh_pkt_addbyte(pkt, pkt_type);
2101 pkt->body = pkt->data + pkt->length;
2102 pkt->type = pkt_type;
2103 pkt->downstream_id = 0;
2104 pkt->additional_log_text = NULL;
2108 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
2109 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
2110 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
2111 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
2112 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
2113 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
2114 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
2115 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
2116 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
2118 static struct Packet *ssh2_pkt_init(int pkt_type)
2120 struct Packet *pkt = ssh_new_packet();
2121 pkt->length = 5; /* space for packet length + padding length */
2123 pkt->type = pkt_type;
2124 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
2125 pkt->body = pkt->data + pkt->length; /* after packet type */
2126 pkt->downstream_id = 0;
2127 pkt->additional_log_text = NULL;
2132 * Construct an SSH-2 final-form packet: compress it, encrypt it,
2133 * put the MAC on it. Final packet, ready to be sent, is stored in
2134 * pkt->data. Total length is returned.
2136 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
2138 int cipherblk, maclen, padding, i;
2141 ssh2_log_outgoing_packet(ssh, pkt);
2143 if (ssh->bare_connection) {
2145 * Trivial packet construction for the bare connection
2148 PUT_32BIT(pkt->data + 1, pkt->length - 5);
2149 pkt->body = pkt->data + 1;
2150 ssh->v2_outgoing_sequence++; /* only for diagnostics, really */
2151 return pkt->length - 1;
2155 * Compress packet payload.
2158 unsigned char *newpayload;
2161 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
2163 &newpayload, &newlen)) {
2165 ssh2_pkt_adddata(pkt, newpayload, newlen);
2171 * Add padding. At least four bytes, and must also bring total
2172 * length (minus MAC) up to a multiple of the block size.
2173 * If pkt->forcepad is set, make sure the packet is at least that size
2176 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
2177 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
2179 if (pkt->length + padding < pkt->forcepad)
2180 padding = pkt->forcepad - pkt->length;
2182 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2183 assert(padding <= 255);
2184 maclen = ssh->csmac ? ssh->csmac->len : 0;
2185 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2186 pkt->data[4] = padding;
2187 for (i = 0; i < padding; i++)
2188 pkt->data[pkt->length + i] = random_byte();
2189 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2191 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2192 pkt->length + padding,
2193 ssh->v2_outgoing_sequence);
2194 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2197 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2198 pkt->data, pkt->length + padding);
2200 pkt->encrypted_len = pkt->length + padding;
2202 /* Ready-to-send packet starts at pkt->data. We return length. */
2203 pkt->body = pkt->data;
2204 return pkt->length + padding + maclen;
2208 * Routines called from the main SSH code to send packets. There
2209 * are quite a few of these, because we have two separate
2210 * mechanisms for delaying the sending of packets:
2212 * - In order to send an IGNORE message and a password message in
2213 * a single fixed-length blob, we require the ability to
2214 * concatenate the encrypted forms of those two packets _into_ a
2215 * single blob and then pass it to our <network.h> transport
2216 * layer in one go. Hence, there's a deferment mechanism which
2217 * works after packet encryption.
2219 * - In order to avoid sending any connection-layer messages
2220 * during repeat key exchange, we have to queue up any such
2221 * outgoing messages _before_ they are encrypted (and in
2222 * particular before they're allocated sequence numbers), and
2223 * then send them once we've finished.
2225 * I call these mechanisms `defer' and `queue' respectively, so as
2226 * to distinguish them reasonably easily.
2228 * The functions send_noqueue() and defer_noqueue() free the packet
2229 * structure they are passed. Every outgoing packet goes through
2230 * precisely one of these functions in its life; packets passed to
2231 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2232 * these or get queued, and then when the queue is later emptied
2233 * the packets are all passed to defer_noqueue().
2235 * When using a CBC-mode cipher, it's necessary to ensure that an
2236 * attacker can't provide data to be encrypted using an IV that they
2237 * know. We ensure this by prefixing each packet that might contain
2238 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2239 * mechanism, so in this case send_noqueue() ends up redirecting to
2240 * defer_noqueue(). If you don't like this inefficiency, don't use
2244 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2245 static void ssh_pkt_defersend(Ssh);
2248 * Send an SSH-2 packet immediately, without queuing or deferring.
2250 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2254 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2255 /* We need to send two packets, so use the deferral mechanism. */
2256 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2257 ssh_pkt_defersend(ssh);
2260 len = ssh2_pkt_construct(ssh, pkt);
2261 backlog = s_write(ssh, pkt->body, len);
2262 if (backlog > SSH_MAX_BACKLOG)
2263 ssh_throttle_all(ssh, 1, backlog);
2265 ssh->outgoing_data_size += pkt->encrypted_len;
2266 if (!ssh->kex_in_progress &&
2267 !ssh->bare_connection &&
2268 ssh->max_data_size != 0 &&
2269 ssh->outgoing_data_size > ssh->max_data_size)
2270 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2272 ssh_free_packet(pkt);
2276 * Defer an SSH-2 packet.
2278 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2281 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2282 ssh->deferred_len == 0 && !noignore &&
2283 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2285 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2286 * get encrypted with a known IV.
2288 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2289 ssh2_pkt_addstring_start(ipkt);
2290 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2292 len = ssh2_pkt_construct(ssh, pkt);
2293 if (ssh->deferred_len + len > ssh->deferred_size) {
2294 ssh->deferred_size = ssh->deferred_len + len + 128;
2295 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2299 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len);
2300 ssh->deferred_len += len;
2301 ssh->deferred_data_size += pkt->encrypted_len;
2302 ssh_free_packet(pkt);
2306 * Queue an SSH-2 packet.
2308 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2310 assert(ssh->queueing);
2312 if (ssh->queuelen >= ssh->queuesize) {
2313 ssh->queuesize = ssh->queuelen + 32;
2314 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2317 ssh->queue[ssh->queuelen++] = pkt;
2321 * Either queue or send a packet, depending on whether queueing is
2324 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2327 ssh2_pkt_queue(ssh, pkt);
2329 ssh2_pkt_send_noqueue(ssh, pkt);
2333 * Either queue or defer a packet, depending on whether queueing is
2336 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2339 ssh2_pkt_queue(ssh, pkt);
2341 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2345 * Send the whole deferred data block constructed by
2346 * ssh2_pkt_defer() or SSH-1's defer_packet().
2348 * The expected use of the defer mechanism is that you call
2349 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2350 * not currently queueing, this simply sets up deferred_send_data
2351 * and then sends it. If we _are_ currently queueing, the calls to
2352 * ssh2_pkt_defer() put the deferred packets on to the queue
2353 * instead, and therefore ssh_pkt_defersend() has no deferred data
2354 * to send. Hence, there's no need to make it conditional on
2357 static void ssh_pkt_defersend(Ssh ssh)
2360 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2361 ssh->deferred_len = ssh->deferred_size = 0;
2362 sfree(ssh->deferred_send_data);
2363 ssh->deferred_send_data = NULL;
2364 if (backlog > SSH_MAX_BACKLOG)
2365 ssh_throttle_all(ssh, 1, backlog);
2367 ssh->outgoing_data_size += ssh->deferred_data_size;
2368 if (!ssh->kex_in_progress &&
2369 !ssh->bare_connection &&
2370 ssh->max_data_size != 0 &&
2371 ssh->outgoing_data_size > ssh->max_data_size)
2372 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2373 ssh->deferred_data_size = 0;
2377 * Send a packet whose length needs to be disguised (typically
2378 * passwords or keyboard-interactive responses).
2380 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2386 * The simplest way to do this is to adjust the
2387 * variable-length padding field in the outgoing packet.
2389 * Currently compiled out, because some Cisco SSH servers
2390 * don't like excessively padded packets (bah, why's it
2393 pkt->forcepad = padsize;
2394 ssh2_pkt_send(ssh, pkt);
2399 * If we can't do that, however, an alternative approach is
2400 * to use the pkt_defer mechanism to bundle the packet
2401 * tightly together with an SSH_MSG_IGNORE such that their
2402 * combined length is a constant. So first we construct the
2403 * final form of this packet and defer its sending.
2405 ssh2_pkt_defer(ssh, pkt);
2408 * Now construct an SSH_MSG_IGNORE which includes a string
2409 * that's an exact multiple of the cipher block size. (If
2410 * the cipher is NULL so that the block size is
2411 * unavailable, we don't do this trick at all, because we
2412 * gain nothing by it.)
2414 if (ssh->cscipher &&
2415 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2418 stringlen = (256 - ssh->deferred_len);
2419 stringlen += ssh->cscipher->blksize - 1;
2420 stringlen -= (stringlen % ssh->cscipher->blksize);
2423 * Temporarily disable actual compression, so we
2424 * can guarantee to get this string exactly the
2425 * length we want it. The compression-disabling
2426 * routine should return an integer indicating how
2427 * many bytes we should adjust our string length
2431 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2433 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2434 ssh2_pkt_addstring_start(pkt);
2435 for (i = 0; i < stringlen; i++) {
2436 char c = (char) random_byte();
2437 ssh2_pkt_addstring_data(pkt, &c, 1);
2439 ssh2_pkt_defer(ssh, pkt);
2441 ssh_pkt_defersend(ssh);
2446 * Send all queued SSH-2 packets. We send them by means of
2447 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2448 * packets that needed to be lumped together.
2450 static void ssh2_pkt_queuesend(Ssh ssh)
2454 assert(!ssh->queueing);
2456 for (i = 0; i < ssh->queuelen; i++)
2457 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2460 ssh_pkt_defersend(ssh);
2464 void bndebug(char *string, Bignum b)
2468 p = ssh2_mpint_fmt(b, &len);
2469 debug(("%s", string));
2470 for (i = 0; i < len; i++)
2471 debug((" %02x", p[i]));
2477 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2481 p = ssh2_mpint_fmt(b, &len);
2482 hash_string(h, s, p, len);
2487 * Packet decode functions for both SSH-1 and SSH-2.
2489 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2491 unsigned long value;
2492 if (pkt->length - pkt->savedpos < 4)
2493 return 0; /* arrgh, no way to decline (FIXME?) */
2494 value = GET_32BIT(pkt->body + pkt->savedpos);
2498 static int ssh2_pkt_getbool(struct Packet *pkt)
2500 unsigned long value;
2501 if (pkt->length - pkt->savedpos < 1)
2502 return 0; /* arrgh, no way to decline (FIXME?) */
2503 value = pkt->body[pkt->savedpos] != 0;
2507 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2512 if (pkt->length - pkt->savedpos < 4)
2514 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2519 if (pkt->length - pkt->savedpos < *length)
2521 *p = (char *)(pkt->body + pkt->savedpos);
2522 pkt->savedpos += *length;
2524 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2526 if (pkt->length - pkt->savedpos < length)
2528 pkt->savedpos += length;
2529 return pkt->body + (pkt->savedpos - length);
2531 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2532 unsigned char **keystr)
2536 j = makekey(pkt->body + pkt->savedpos,
2537 pkt->length - pkt->savedpos,
2544 assert(pkt->savedpos < pkt->length);
2548 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2553 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2554 pkt->length - pkt->savedpos, &b);
2562 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2568 ssh_pkt_getstring(pkt, &p, &length);
2573 b = bignum_from_bytes((unsigned char *)p, length);
2578 * Helper function to add an SSH-2 signature blob to a packet.
2579 * Expects to be shown the public key blob as well as the signature
2580 * blob. Normally works just like ssh2_pkt_addstring, but will
2581 * fiddle with the signature packet if necessary for
2582 * BUG_SSH2_RSA_PADDING.
2584 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2585 void *pkblob_v, int pkblob_len,
2586 void *sigblob_v, int sigblob_len)
2588 unsigned char *pkblob = (unsigned char *)pkblob_v;
2589 unsigned char *sigblob = (unsigned char *)sigblob_v;
2591 /* dmemdump(pkblob, pkblob_len); */
2592 /* dmemdump(sigblob, sigblob_len); */
2595 * See if this is in fact an ssh-rsa signature and a buggy
2596 * server; otherwise we can just do this the easy way.
2598 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2599 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2600 int pos, len, siglen;
2603 * Find the byte length of the modulus.
2606 pos = 4+7; /* skip over "ssh-rsa" */
2607 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2608 if (len < 0 || len > pkblob_len - pos - 4)
2610 pos += 4 + len; /* skip over exponent */
2611 if (pkblob_len - pos < 4)
2613 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2614 if (len < 0 || len > pkblob_len - pos - 4)
2616 pos += 4; /* find modulus itself */
2617 while (len > 0 && pkblob[pos] == 0)
2619 /* debug(("modulus length is %d\n", len)); */
2622 * Now find the signature integer.
2624 pos = 4+7; /* skip over "ssh-rsa" */
2625 if (sigblob_len < pos+4)
2627 siglen = toint(GET_32BIT(sigblob+pos));
2628 if (siglen != sigblob_len - pos - 4)
2630 /* debug(("signature length is %d\n", siglen)); */
2632 if (len != siglen) {
2633 unsigned char newlen[4];
2634 ssh2_pkt_addstring_start(pkt);
2635 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2636 /* dmemdump(sigblob, pos); */
2637 pos += 4; /* point to start of actual sig */
2638 PUT_32BIT(newlen, len);
2639 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2640 /* dmemdump(newlen, 4); */
2642 while (len-- > siglen) {
2643 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2644 /* dmemdump(newlen, 1); */
2646 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2647 /* dmemdump(sigblob+pos, siglen); */
2651 /* Otherwise fall through and do it the easy way. We also come
2652 * here as a fallback if we discover above that the key blob
2653 * is misformatted in some way. */
2657 ssh2_pkt_addstring_start(pkt);
2658 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2662 * Examine the remote side's version string and compare it against
2663 * a list of known buggy implementations.
2665 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2667 char *imp; /* pointer to implementation part */
2669 imp += strcspn(imp, "-");
2671 imp += strcspn(imp, "-");
2674 ssh->remote_bugs = 0;
2677 * General notes on server version strings:
2678 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2679 * here -- in particular, we've heard of one that's perfectly happy
2680 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2681 * so we can't distinguish them.
2683 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2684 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2685 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2686 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2687 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2688 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2690 * These versions don't support SSH1_MSG_IGNORE, so we have
2691 * to use a different defence against password length
2694 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2695 logevent("We believe remote version has SSH-1 ignore bug");
2698 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2699 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2700 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2702 * These versions need a plain password sent; they can't
2703 * handle having a null and a random length of data after
2706 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2707 logevent("We believe remote version needs a plain SSH-1 password");
2710 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2711 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2712 (!strcmp(imp, "Cisco-1.25")))) {
2714 * These versions apparently have no clue whatever about
2715 * RSA authentication and will panic and die if they see
2716 * an AUTH_RSA message.
2718 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2719 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2722 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2723 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2724 !wc_match("* VShell", imp) &&
2725 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2726 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2727 wc_match("2.1 *", imp)))) {
2729 * These versions have the HMAC bug.
2731 ssh->remote_bugs |= BUG_SSH2_HMAC;
2732 logevent("We believe remote version has SSH-2 HMAC bug");
2735 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2736 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2737 !wc_match("* VShell", imp) &&
2738 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2740 * These versions have the key-derivation bug (failing to
2741 * include the literal shared secret in the hashes that
2742 * generate the keys).
2744 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2745 logevent("We believe remote version has SSH-2 key-derivation bug");
2748 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2749 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2750 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2751 wc_match("OpenSSH_3.[0-2]*", imp) ||
2752 wc_match("mod_sftp/0.[0-8]*", imp) ||
2753 wc_match("mod_sftp/0.9.[0-8]", imp)))) {
2755 * These versions have the SSH-2 RSA padding bug.
2757 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2758 logevent("We believe remote version has SSH-2 RSA padding bug");
2761 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2762 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2763 wc_match("OpenSSH_2.[0-2]*", imp))) {
2765 * These versions have the SSH-2 session-ID bug in
2766 * public-key authentication.
2768 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2769 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2772 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2773 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2774 (wc_match("DigiSSH_2.0", imp) ||
2775 wc_match("OpenSSH_2.[0-4]*", imp) ||
2776 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2777 wc_match("Sun_SSH_1.0", imp) ||
2778 wc_match("Sun_SSH_1.0.1", imp) ||
2779 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2780 wc_match("WeOnlyDo-*", imp)))) {
2782 * These versions have the SSH-2 rekey bug.
2784 ssh->remote_bugs |= BUG_SSH2_REKEY;
2785 logevent("We believe remote version has SSH-2 rekey bug");
2788 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2789 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2790 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2791 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2793 * This version ignores our makpkt and needs to be throttled.
2795 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2796 logevent("We believe remote version ignores SSH-2 maximum packet size");
2799 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2801 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2802 * none detected automatically.
2804 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2805 logevent("We believe remote version has SSH-2 ignore bug");
2808 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2810 * Servers that don't support our winadj request for one
2811 * reason or another. Currently, none detected automatically.
2813 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2814 logevent("We believe remote version has winadj bug");
2817 if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON ||
2818 (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO &&
2819 (wc_match("OpenSSH_[2-5].*", imp) ||
2820 wc_match("OpenSSH_6.[0-6]*", imp)))) {
2822 * These versions have the SSH-2 channel request bug. 6.7 and
2824 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2826 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2827 logevent("We believe remote version has SSH-2 channel request bug");
2832 * The `software version' part of an SSH version string is required
2833 * to contain no spaces or minus signs.
2835 static void ssh_fix_verstring(char *str)
2837 /* Eat "<protoversion>-". */
2838 while (*str && *str != '-') str++;
2839 assert(*str == '-'); str++;
2841 /* Convert minus signs and spaces in the remaining string into
2844 if (*str == '-' || *str == ' ')
2851 * Send an appropriate SSH version string.
2853 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2857 if (ssh->version == 2) {
2859 * Construct a v2 version string.
2861 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2864 * Construct a v1 version string.
2866 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2867 verstring = dupprintf("SSH-%s-%s\012",
2868 (ssh_versioncmp(svers, "1.5") <= 0 ?
2873 ssh_fix_verstring(verstring + strlen(protoname));
2875 if (ssh->version == 2) {
2878 * Record our version string.
2880 len = strcspn(verstring, "\015\012");
2881 ssh->v_c = snewn(len + 1, char);
2882 memcpy(ssh->v_c, verstring, len);
2886 logeventf(ssh, "We claim version: %.*s",
2887 strcspn(verstring, "\015\012"), verstring);
2888 s_write(ssh, verstring, strlen(verstring));
2892 static int do_ssh_init(Ssh ssh, unsigned char c)
2894 static const char protoname[] = "SSH-";
2896 struct do_ssh_init_state {
2905 crState(do_ssh_init_state);
2909 /* Search for a line beginning with the protocol name prefix in
2912 for (s->i = 0; protoname[s->i]; s->i++) {
2913 if ((char)c != protoname[s->i]) goto no;
2923 s->vstrsize = sizeof(protoname) + 16;
2924 s->vstring = snewn(s->vstrsize, char);
2925 strcpy(s->vstring, protoname);
2926 s->vslen = strlen(protoname);
2929 if (s->vslen >= s->vstrsize - 1) {
2931 s->vstring = sresize(s->vstring, s->vstrsize, char);
2933 s->vstring[s->vslen++] = c;
2936 s->version[s->i] = '\0';
2938 } else if (s->i < sizeof(s->version) - 1)
2939 s->version[s->i++] = c;
2940 } else if (c == '\012')
2942 crReturn(1); /* get another char */
2945 ssh->agentfwd_enabled = FALSE;
2946 ssh->rdpkt2_state.incoming_sequence = 0;
2948 s->vstring[s->vslen] = 0;
2949 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2950 logeventf(ssh, "Server version: %s", s->vstring);
2951 ssh_detect_bugs(ssh, s->vstring);
2954 * Decide which SSH protocol version to support.
2957 /* Anything strictly below "2.0" means protocol 1 is supported. */
2958 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2959 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2960 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2962 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2963 bombout(("SSH protocol version 1 required by user but not provided by server"));
2966 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2967 bombout(("SSH protocol version 2 required by user but not provided by server"));
2971 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2976 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2978 /* Send the version string, if we haven't already */
2979 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2980 ssh_send_verstring(ssh, protoname, s->version);
2982 if (ssh->version == 2) {
2985 * Record their version string.
2987 len = strcspn(s->vstring, "\015\012");
2988 ssh->v_s = snewn(len + 1, char);
2989 memcpy(ssh->v_s, s->vstring, len);
2993 * Initialise SSH-2 protocol.
2995 ssh->protocol = ssh2_protocol;
2996 ssh2_protocol_setup(ssh);
2997 ssh->s_rdpkt = ssh2_rdpkt;
3000 * Initialise SSH-1 protocol.
3002 ssh->protocol = ssh1_protocol;
3003 ssh1_protocol_setup(ssh);
3004 ssh->s_rdpkt = ssh1_rdpkt;
3006 if (ssh->version == 2)
3007 do_ssh2_transport(ssh, NULL, -1, NULL);
3009 update_specials_menu(ssh->frontend);
3010 ssh->state = SSH_STATE_BEFORE_SIZE;
3011 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3018 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3021 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3022 * the ssh-connection part, extracted and given a trivial binary
3023 * packet protocol, so we replace 'SSH-' at the start with a new
3024 * name. In proper SSH style (though of course this part of the
3025 * proper SSH protocol _isn't_ subject to this kind of
3026 * DNS-domain-based extension), we define the new name in our
3029 static const char protoname[] =
3030 "SSHCONNECTION@putty.projects.tartarus.org-";
3032 struct do_ssh_connection_init_state {
3040 crState(do_ssh_connection_init_state);
3044 /* Search for a line beginning with the protocol name prefix in
3047 for (s->i = 0; protoname[s->i]; s->i++) {
3048 if ((char)c != protoname[s->i]) goto no;
3058 s->vstrsize = sizeof(protoname) + 16;
3059 s->vstring = snewn(s->vstrsize, char);
3060 strcpy(s->vstring, protoname);
3061 s->vslen = strlen(protoname);
3064 if (s->vslen >= s->vstrsize - 1) {
3066 s->vstring = sresize(s->vstring, s->vstrsize, char);
3068 s->vstring[s->vslen++] = c;
3071 s->version[s->i] = '\0';
3073 } else if (s->i < sizeof(s->version) - 1)
3074 s->version[s->i++] = c;
3075 } else if (c == '\012')
3077 crReturn(1); /* get another char */
3080 ssh->agentfwd_enabled = FALSE;
3081 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3083 s->vstring[s->vslen] = 0;
3084 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3085 logeventf(ssh, "Server version: %s", s->vstring);
3086 ssh_detect_bugs(ssh, s->vstring);
3089 * Decide which SSH protocol version to support. This is easy in
3090 * bare ssh-connection mode: only 2.0 is legal.
3092 if (ssh_versioncmp(s->version, "2.0") < 0) {
3093 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3096 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3097 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3103 logeventf(ssh, "Using bare ssh-connection protocol");
3105 /* Send the version string, if we haven't already */
3106 ssh_send_verstring(ssh, protoname, s->version);
3109 * Initialise bare connection protocol.
3111 ssh->protocol = ssh2_bare_connection_protocol;
3112 ssh2_bare_connection_protocol_setup(ssh);
3113 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3115 update_specials_menu(ssh->frontend);
3116 ssh->state = SSH_STATE_BEFORE_SIZE;
3117 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3120 * Get authconn (really just conn) under way.
3122 do_ssh2_authconn(ssh, NULL, 0, NULL);
3129 static void ssh_process_incoming_data(Ssh ssh,
3130 unsigned char **data, int *datalen)
3132 struct Packet *pktin;
3134 pktin = ssh->s_rdpkt(ssh, data, datalen);
3136 ssh->protocol(ssh, NULL, 0, pktin);
3137 ssh_free_packet(pktin);
3141 static void ssh_queue_incoming_data(Ssh ssh,
3142 unsigned char **data, int *datalen)
3144 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3149 static void ssh_process_queued_incoming_data(Ssh ssh)
3152 unsigned char *data;
3155 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3156 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3160 while (!ssh->frozen && len > 0)
3161 ssh_process_incoming_data(ssh, &data, &len);
3164 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3168 static void ssh_set_frozen(Ssh ssh, int frozen)
3171 sk_set_frozen(ssh->s, frozen);
3172 ssh->frozen = frozen;
3175 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3177 /* Log raw data, if we're in that mode. */
3179 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3180 0, NULL, NULL, 0, NULL);
3182 crBegin(ssh->ssh_gotdata_crstate);
3185 * To begin with, feed the characters one by one to the
3186 * protocol initialisation / selection function do_ssh_init().
3187 * When that returns 0, we're done with the initial greeting
3188 * exchange and can move on to packet discipline.
3191 int ret; /* need not be kept across crReturn */
3193 crReturnV; /* more data please */
3194 ret = ssh->do_ssh_init(ssh, *data);
3202 * We emerge from that loop when the initial negotiation is
3203 * over and we have selected an s_rdpkt function. Now pass
3204 * everything to s_rdpkt, and then pass the resulting packets
3205 * to the proper protocol handler.
3209 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3211 ssh_queue_incoming_data(ssh, &data, &datalen);
3212 /* This uses up all data and cannot cause anything interesting
3213 * to happen; indeed, for anything to happen at all, we must
3214 * return, so break out. */
3216 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3217 /* This uses up some or all data, and may freeze the
3219 ssh_process_queued_incoming_data(ssh);
3221 /* This uses up some or all data, and may freeze the
3223 ssh_process_incoming_data(ssh, &data, &datalen);
3225 /* FIXME this is probably EBW. */
3226 if (ssh->state == SSH_STATE_CLOSED)
3229 /* We're out of data. Go and get some more. */
3235 static int ssh_do_close(Ssh ssh, int notify_exit)
3238 struct ssh_channel *c;
3240 ssh->state = SSH_STATE_CLOSED;
3241 expire_timer_context(ssh);
3246 notify_remote_exit(ssh->frontend);
3251 * Now we must shut down any port- and X-forwarded channels going
3252 * through this connection.
3254 if (ssh->channels) {
3255 while (NULL != (c = index234(ssh->channels, 0))) {
3258 x11_close(c->u.x11.xconn);
3261 case CHAN_SOCKDATA_DORMANT:
3262 pfd_close(c->u.pfd.pf);
3265 del234(ssh->channels, c); /* moving next one to index 0 */
3266 if (ssh->version == 2)
3267 bufchain_clear(&c->v.v2.outbuffer);
3272 * Go through port-forwardings, and close any associated
3273 * listening sockets.
3275 if (ssh->portfwds) {
3276 struct ssh_portfwd *pf;
3277 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3278 /* Dispose of any listening socket. */
3280 pfl_terminate(pf->local);
3281 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3284 freetree234(ssh->portfwds);
3285 ssh->portfwds = NULL;
3291 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3292 const char *error_msg, int error_code)
3294 Ssh ssh = (Ssh) plug;
3295 char addrbuf[256], *msg;
3297 if (ssh->attempting_connshare) {
3299 * While we're attempting connection sharing, don't loudly log
3300 * everything that happens. Real TCP connections need to be
3301 * logged when we _start_ trying to connect, because it might
3302 * be ages before they respond if something goes wrong; but
3303 * connection sharing is local and quick to respond, and it's
3304 * sufficient to simply wait and see whether it worked
3308 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3311 if (sk_addr_needs_port(addr)) {
3312 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3314 msg = dupprintf("Connecting to %s", addrbuf);
3317 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3325 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3326 const char *ds_err, const char *us_err)
3328 if (event == SHARE_NONE) {
3329 /* In this case, 'logtext' is an error message indicating a
3330 * reason why connection sharing couldn't be set up _at all_.
3331 * Failing that, ds_err and us_err indicate why we couldn't be
3332 * a downstream and an upstream respectively. */
3334 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3337 logeventf(ssh, "Could not set up connection sharing"
3338 " as downstream: %s", ds_err);
3340 logeventf(ssh, "Could not set up connection sharing"
3341 " as upstream: %s", us_err);
3343 } else if (event == SHARE_DOWNSTREAM) {
3344 /* In this case, 'logtext' is a local endpoint address */
3345 logeventf(ssh, "Using existing shared connection at %s", logtext);
3346 /* Also we should mention this in the console window to avoid
3347 * confusing users as to why this window doesn't behave the
3349 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3350 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3352 } else if (event == SHARE_UPSTREAM) {
3353 /* In this case, 'logtext' is a local endpoint address too */
3354 logeventf(ssh, "Sharing this connection at %s", logtext);
3358 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3361 Ssh ssh = (Ssh) plug;
3362 int need_notify = ssh_do_close(ssh, FALSE);
3365 if (!ssh->close_expected)
3366 error_msg = "Server unexpectedly closed network connection";
3368 error_msg = "Server closed network connection";
3371 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3375 notify_remote_exit(ssh->frontend);
3378 logevent(error_msg);
3379 if (!ssh->close_expected || !ssh->clean_exit)
3380 connection_fatal(ssh->frontend, "%s", error_msg);
3384 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3386 Ssh ssh = (Ssh) plug;
3387 ssh_gotdata(ssh, (unsigned char *)data, len);
3388 if (ssh->state == SSH_STATE_CLOSED) {
3389 ssh_do_close(ssh, TRUE);
3395 static void ssh_sent(Plug plug, int bufsize)
3397 Ssh ssh = (Ssh) plug;
3399 * If the send backlog on the SSH socket itself clears, we
3400 * should unthrottle the whole world if it was throttled.
3402 if (bufsize < SSH_MAX_BACKLOG)
3403 ssh_throttle_all(ssh, 0, bufsize);
3407 * Connect to specified host and port.
3408 * Returns an error message, or NULL on success.
3409 * Also places the canonical host name into `realhost'. It must be
3410 * freed by the caller.
3412 static const char *connect_to_host(Ssh ssh, char *host, int port,
3413 char **realhost, int nodelay, int keepalive)
3415 static const struct plug_function_table fn_table = {
3426 int addressfamily, sshprot;
3428 loghost = conf_get_str(ssh->conf, CONF_loghost);
3433 tmphost = dupstr(loghost);
3434 ssh->savedport = 22; /* default ssh port */
3437 * A colon suffix on the hostname string also lets us affect
3438 * savedport. (Unless there are multiple colons, in which case
3439 * we assume this is an unbracketed IPv6 literal.)
3441 colon = host_strrchr(tmphost, ':');
3442 if (colon && colon == host_strchr(tmphost, ':')) {
3445 ssh->savedport = atoi(colon);
3448 ssh->savedhost = host_strduptrim(tmphost);
3451 ssh->savedhost = host_strduptrim(host);
3453 port = 22; /* default ssh port */
3454 ssh->savedport = port;
3457 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3460 * Try connection-sharing, in case that means we don't open a
3461 * socket after all. ssh_connection_sharing_init will connect to a
3462 * previously established upstream if it can, and failing that,
3463 * establish a listening socket for _us_ to be the upstream. In
3464 * the latter case it will return NULL just as if it had done
3465 * nothing, because here we only need to care if we're a
3466 * downstream and need to do our connection setup differently.
3468 ssh->connshare = NULL;
3469 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3470 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3471 ssh->conf, ssh, &ssh->connshare);
3472 ssh->attempting_connshare = FALSE;
3473 if (ssh->s != NULL) {
3475 * We are a downstream.
3477 ssh->bare_connection = TRUE;
3478 ssh->do_ssh_init = do_ssh_connection_init;
3479 ssh->fullhostname = NULL;
3480 *realhost = dupstr(host); /* best we can do */
3483 * We're not a downstream, so open a normal socket.
3485 ssh->do_ssh_init = do_ssh_init;
3490 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3491 logeventf(ssh, "Looking up host \"%s\"%s", host,
3492 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3493 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3494 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3495 if ((err = sk_addr_error(addr)) != NULL) {
3499 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3501 ssh->s = new_connection(addr, *realhost, port,
3502 0, 1, nodelay, keepalive,
3503 (Plug) ssh, ssh->conf);
3504 if ((err = sk_socket_error(ssh->s)) != NULL) {
3506 notify_remote_exit(ssh->frontend);
3512 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3513 * send the version string too.
3515 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3518 if (sshprot == 3 && !ssh->bare_connection) {
3520 ssh_send_verstring(ssh, "SSH-", NULL);
3524 * loghost, if configured, overrides realhost.
3528 *realhost = dupstr(loghost);
3535 * Throttle or unthrottle the SSH connection.
3537 static void ssh_throttle_conn(Ssh ssh, int adjust)
3539 int old_count = ssh->conn_throttle_count;
3540 ssh->conn_throttle_count += adjust;
3541 assert(ssh->conn_throttle_count >= 0);
3542 if (ssh->conn_throttle_count && !old_count) {
3543 ssh_set_frozen(ssh, 1);
3544 } else if (!ssh->conn_throttle_count && old_count) {
3545 ssh_set_frozen(ssh, 0);
3550 * Throttle or unthrottle _all_ local data streams (for when sends
3551 * on the SSH connection itself back up).
3553 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3556 struct ssh_channel *c;
3558 if (enable == ssh->throttled_all)
3560 ssh->throttled_all = enable;
3561 ssh->overall_bufsize = bufsize;
3564 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3566 case CHAN_MAINSESSION:
3568 * This is treated separately, outside the switch.
3572 x11_override_throttle(c->u.x11.xconn, enable);
3575 /* Agent channels require no buffer management. */
3578 pfd_override_throttle(c->u.pfd.pf, enable);
3584 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3586 Ssh ssh = (Ssh) sshv;
3588 ssh->agent_response = reply;
3589 ssh->agent_response_len = replylen;
3591 if (ssh->version == 1)
3592 do_ssh1_login(ssh, NULL, -1, NULL);
3594 do_ssh2_authconn(ssh, NULL, -1, NULL);
3597 static void ssh_dialog_callback(void *sshv, int ret)
3599 Ssh ssh = (Ssh) sshv;
3601 ssh->user_response = ret;
3603 if (ssh->version == 1)
3604 do_ssh1_login(ssh, NULL, -1, NULL);
3606 do_ssh2_transport(ssh, NULL, -1, NULL);
3609 * This may have unfrozen the SSH connection, so do a
3612 ssh_process_queued_incoming_data(ssh);
3615 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3617 struct ssh_channel *c = (struct ssh_channel *)cv;
3619 void *sentreply = reply;
3621 c->u.a.outstanding_requests--;
3623 /* Fake SSH_AGENT_FAILURE. */
3624 sentreply = "\0\0\0\1\5";
3627 if (ssh->version == 2) {
3628 ssh2_add_channel_data(c, sentreply, replylen);
3631 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3632 PKT_INT, c->remoteid,
3634 PKT_DATA, sentreply, replylen,
3640 * If we've already seen an incoming EOF but haven't sent an
3641 * outgoing one, this may be the moment to send it.
3643 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3644 sshfwd_write_eof(c);
3648 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3649 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3650 * => log `wire_reason'.
3652 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3653 int code, int clean_exit)
3657 client_reason = wire_reason;
3659 error = dupprintf("Disconnected: %s", client_reason);
3661 error = dupstr("Disconnected");
3663 if (ssh->version == 1) {
3664 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3666 } else if (ssh->version == 2) {
3667 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3668 ssh2_pkt_adduint32(pktout, code);
3669 ssh2_pkt_addstring(pktout, wire_reason);
3670 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3671 ssh2_pkt_send_noqueue(ssh, pktout);
3674 ssh->close_expected = TRUE;
3675 ssh->clean_exit = clean_exit;
3676 ssh_closing((Plug)ssh, error, 0, 0);
3681 * Handle the key exchange and user authentication phases.
3683 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3684 struct Packet *pktin)
3687 unsigned char cookie[8], *ptr;
3688 struct MD5Context md5c;
3689 struct do_ssh1_login_state {
3692 unsigned char *rsabuf, *keystr1, *keystr2;
3693 unsigned long supported_ciphers_mask, supported_auths_mask;
3694 int tried_publickey, tried_agent;
3695 int tis_auth_refused, ccard_auth_refused;
3696 unsigned char session_id[16];
3698 void *publickey_blob;
3699 int publickey_bloblen;
3700 char *publickey_comment;
3701 int publickey_encrypted;
3702 prompts_t *cur_prompt;
3705 unsigned char request[5], *response, *p;
3715 struct RSAKey servkey, hostkey;
3717 crState(do_ssh1_login_state);
3724 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3725 bombout(("Public key packet not received"));
3729 logevent("Received public keys");
3731 ptr = ssh_pkt_getdata(pktin, 8);
3733 bombout(("SSH-1 public key packet stopped before random cookie"));
3736 memcpy(cookie, ptr, 8);
3738 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3739 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3740 bombout(("Failed to read SSH-1 public keys from public key packet"));
3745 * Log the host key fingerprint.
3749 logevent("Host key fingerprint is:");
3750 strcpy(logmsg, " ");
3751 s->hostkey.comment = NULL;
3752 rsa_fingerprint(logmsg + strlen(logmsg),
3753 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3757 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3758 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3759 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3760 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3761 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3763 ssh->v1_local_protoflags =
3764 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3765 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3768 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3769 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3770 MD5Update(&md5c, cookie, 8);
3771 MD5Final(s->session_id, &md5c);
3773 for (i = 0; i < 32; i++)
3774 ssh->session_key[i] = random_byte();
3777 * Verify that the `bits' and `bytes' parameters match.
3779 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3780 s->servkey.bits > s->servkey.bytes * 8) {
3781 bombout(("SSH-1 public keys were badly formatted"));
3785 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3786 s->hostkey.bytes : s->servkey.bytes);
3788 s->rsabuf = snewn(s->len, unsigned char);
3791 * Verify the host key.
3795 * First format the key into a string.
3797 int len = rsastr_len(&s->hostkey);
3798 char fingerprint[100];
3799 char *keystr = snewn(len, char);
3800 rsastr_fmt(keystr, &s->hostkey);
3801 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3803 ssh_set_frozen(ssh, 1);
3804 s->dlgret = verify_ssh_host_key(ssh->frontend,
3805 ssh->savedhost, ssh->savedport,
3806 "rsa", keystr, fingerprint,
3807 ssh_dialog_callback, ssh);
3809 if (s->dlgret < 0) {
3813 bombout(("Unexpected data from server while waiting"
3814 " for user host key response"));
3817 } while (pktin || inlen > 0);
3818 s->dlgret = ssh->user_response;
3820 ssh_set_frozen(ssh, 0);
3822 if (s->dlgret == 0) {
3823 ssh_disconnect(ssh, "User aborted at host key verification",
3829 for (i = 0; i < 32; i++) {
3830 s->rsabuf[i] = ssh->session_key[i];
3832 s->rsabuf[i] ^= s->session_id[i];
3835 if (s->hostkey.bytes > s->servkey.bytes) {
3836 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3838 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3840 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3842 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3845 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3849 logevent("Encrypted session key");
3852 int cipher_chosen = 0, warn = 0;
3853 char *cipher_string = NULL;
3855 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3856 int next_cipher = conf_get_int_int(ssh->conf,
3857 CONF_ssh_cipherlist, i);
3858 if (next_cipher == CIPHER_WARN) {
3859 /* If/when we choose a cipher, warn about it */
3861 } else if (next_cipher == CIPHER_AES) {
3862 /* XXX Probably don't need to mention this. */
3863 logevent("AES not supported in SSH-1, skipping");
3865 switch (next_cipher) {
3866 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3867 cipher_string = "3DES"; break;
3868 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3869 cipher_string = "Blowfish"; break;
3870 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3871 cipher_string = "single-DES"; break;
3873 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3877 if (!cipher_chosen) {
3878 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3879 bombout(("Server violates SSH-1 protocol by not "
3880 "supporting 3DES encryption"));
3882 /* shouldn't happen */
3883 bombout(("No supported ciphers found"));
3887 /* Warn about chosen cipher if necessary. */
3889 ssh_set_frozen(ssh, 1);
3890 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3891 ssh_dialog_callback, ssh);
3892 if (s->dlgret < 0) {
3896 bombout(("Unexpected data from server while waiting"
3897 " for user response"));
3900 } while (pktin || inlen > 0);
3901 s->dlgret = ssh->user_response;
3903 ssh_set_frozen(ssh, 0);
3904 if (s->dlgret == 0) {
3905 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3912 switch (s->cipher_type) {
3913 case SSH_CIPHER_3DES:
3914 logevent("Using 3DES encryption");
3916 case SSH_CIPHER_DES:
3917 logevent("Using single-DES encryption");
3919 case SSH_CIPHER_BLOWFISH:
3920 logevent("Using Blowfish encryption");
3924 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3925 PKT_CHAR, s->cipher_type,
3926 PKT_DATA, cookie, 8,
3927 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3928 PKT_DATA, s->rsabuf, s->len,
3929 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3931 logevent("Trying to enable encryption...");
3935 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3936 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3938 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3939 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3940 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3942 ssh->crcda_ctx = crcda_make_context();
3943 logevent("Installing CRC compensation attack detector");
3945 if (s->servkey.modulus) {
3946 sfree(s->servkey.modulus);
3947 s->servkey.modulus = NULL;
3949 if (s->servkey.exponent) {
3950 sfree(s->servkey.exponent);
3951 s->servkey.exponent = NULL;
3953 if (s->hostkey.modulus) {
3954 sfree(s->hostkey.modulus);
3955 s->hostkey.modulus = NULL;
3957 if (s->hostkey.exponent) {
3958 sfree(s->hostkey.exponent);
3959 s->hostkey.exponent = NULL;
3963 if (pktin->type != SSH1_SMSG_SUCCESS) {
3964 bombout(("Encryption not successfully enabled"));
3968 logevent("Successfully started encryption");
3970 fflush(stdout); /* FIXME eh? */
3972 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3973 int ret; /* need not be kept over crReturn */
3974 s->cur_prompt = new_prompts(ssh->frontend);
3975 s->cur_prompt->to_server = TRUE;
3976 s->cur_prompt->name = dupstr("SSH login name");
3977 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3978 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3981 crWaitUntil(!pktin);
3982 ret = get_userpass_input(s->cur_prompt, in, inlen);
3987 * Failed to get a username. Terminate.
3989 free_prompts(s->cur_prompt);
3990 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3993 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3994 free_prompts(s->cur_prompt);
3997 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3999 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4001 if (flags & FLAG_INTERACTIVE &&
4002 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4003 c_write_str(ssh, userlog);
4004 c_write_str(ssh, "\r\n");
4012 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4013 /* We must not attempt PK auth. Pretend we've already tried it. */
4014 s->tried_publickey = s->tried_agent = 1;
4016 s->tried_publickey = s->tried_agent = 0;
4018 s->tis_auth_refused = s->ccard_auth_refused = 0;
4020 * Load the public half of any configured keyfile for later use.
4022 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4023 if (!filename_is_null(s->keyfile)) {
4025 logeventf(ssh, "Reading private key file \"%.150s\"",
4026 filename_to_str(s->keyfile));
4027 keytype = key_type(s->keyfile);
4028 if (keytype == SSH_KEYTYPE_SSH1) {
4030 if (rsakey_pubblob(s->keyfile,
4031 &s->publickey_blob, &s->publickey_bloblen,
4032 &s->publickey_comment, &error)) {
4033 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4037 logeventf(ssh, "Unable to load private key (%s)", error);
4038 msgbuf = dupprintf("Unable to load private key file "
4039 "\"%.150s\" (%s)\r\n",
4040 filename_to_str(s->keyfile),
4042 c_write_str(ssh, msgbuf);
4044 s->publickey_blob = NULL;
4048 logeventf(ssh, "Unable to use this key file (%s)",
4049 key_type_to_str(keytype));
4050 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4052 filename_to_str(s->keyfile),
4053 key_type_to_str(keytype));
4054 c_write_str(ssh, msgbuf);
4056 s->publickey_blob = NULL;
4059 s->publickey_blob = NULL;
4061 while (pktin->type == SSH1_SMSG_FAILURE) {
4062 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4064 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4066 * Attempt RSA authentication using Pageant.
4072 logevent("Pageant is running. Requesting keys.");
4074 /* Request the keys held by the agent. */
4075 PUT_32BIT(s->request, 1);
4076 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4077 if (!agent_query(s->request, 5, &r, &s->responselen,
4078 ssh_agent_callback, ssh)) {
4082 bombout(("Unexpected data from server while waiting"
4083 " for agent response"));
4086 } while (pktin || inlen > 0);
4087 r = ssh->agent_response;
4088 s->responselen = ssh->agent_response_len;
4090 s->response = (unsigned char *) r;
4091 if (s->response && s->responselen >= 5 &&
4092 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4093 s->p = s->response + 5;
4094 s->nkeys = toint(GET_32BIT(s->p));
4096 logeventf(ssh, "Pageant reported negative key count %d",
4101 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4102 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4103 unsigned char *pkblob = s->p;
4107 do { /* do while (0) to make breaking easy */
4108 n = ssh1_read_bignum
4109 (s->p, toint(s->responselen-(s->p-s->response)),
4114 n = ssh1_read_bignum
4115 (s->p, toint(s->responselen-(s->p-s->response)),
4120 if (s->responselen - (s->p-s->response) < 4)
4122 s->commentlen = toint(GET_32BIT(s->p));
4124 if (s->commentlen < 0 ||
4125 toint(s->responselen - (s->p-s->response)) <
4128 s->commentp = (char *)s->p;
4129 s->p += s->commentlen;
4133 logevent("Pageant key list packet was truncated");
4137 if (s->publickey_blob) {
4138 if (!memcmp(pkblob, s->publickey_blob,
4139 s->publickey_bloblen)) {
4140 logeventf(ssh, "Pageant key #%d matches "
4141 "configured key file", s->keyi);
4142 s->tried_publickey = 1;
4144 /* Skip non-configured key */
4147 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4148 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4149 PKT_BIGNUM, s->key.modulus, PKT_END);
4151 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4152 logevent("Key refused");
4155 logevent("Received RSA challenge");
4156 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4157 bombout(("Server's RSA challenge was badly formatted"));
4162 char *agentreq, *q, *ret;
4165 len = 1 + 4; /* message type, bit count */
4166 len += ssh1_bignum_length(s->key.exponent);
4167 len += ssh1_bignum_length(s->key.modulus);
4168 len += ssh1_bignum_length(s->challenge);
4169 len += 16; /* session id */
4170 len += 4; /* response format */
4171 agentreq = snewn(4 + len, char);
4172 PUT_32BIT(agentreq, len);
4174 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4175 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4177 q += ssh1_write_bignum(q, s->key.exponent);
4178 q += ssh1_write_bignum(q, s->key.modulus);
4179 q += ssh1_write_bignum(q, s->challenge);
4180 memcpy(q, s->session_id, 16);
4182 PUT_32BIT(q, 1); /* response format */
4183 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4184 ssh_agent_callback, ssh)) {
4189 bombout(("Unexpected data from server"
4190 " while waiting for agent"
4194 } while (pktin || inlen > 0);
4195 vret = ssh->agent_response;
4196 retlen = ssh->agent_response_len;
4201 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4202 logevent("Sending Pageant's response");
4203 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4204 PKT_DATA, ret + 5, 16,
4208 if (pktin->type == SSH1_SMSG_SUCCESS) {
4210 ("Pageant's response accepted");
4211 if (flags & FLAG_VERBOSE) {
4212 c_write_str(ssh, "Authenticated using"
4214 c_write(ssh, s->commentp,
4216 c_write_str(ssh, "\" from agent\r\n");
4221 ("Pageant's response not accepted");
4224 ("Pageant failed to answer challenge");
4228 logevent("No reply received from Pageant");
4231 freebn(s->key.exponent);
4232 freebn(s->key.modulus);
4233 freebn(s->challenge);
4238 if (s->publickey_blob && !s->tried_publickey)
4239 logevent("Configured key file not in Pageant");
4241 logevent("Failed to get reply from Pageant");
4246 if (s->publickey_blob && !s->tried_publickey) {
4248 * Try public key authentication with the specified
4251 int got_passphrase; /* need not be kept over crReturn */
4252 if (flags & FLAG_VERBOSE)
4253 c_write_str(ssh, "Trying public key authentication.\r\n");
4254 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4255 logeventf(ssh, "Trying public key \"%s\"",
4256 filename_to_str(s->keyfile));
4257 s->tried_publickey = 1;
4258 got_passphrase = FALSE;
4259 while (!got_passphrase) {
4261 * Get a passphrase, if necessary.
4263 char *passphrase = NULL; /* only written after crReturn */
4265 if (!s->publickey_encrypted) {
4266 if (flags & FLAG_VERBOSE)
4267 c_write_str(ssh, "No passphrase required.\r\n");
4270 int ret; /* need not be kept over crReturn */
4271 s->cur_prompt = new_prompts(ssh->frontend);
4272 s->cur_prompt->to_server = FALSE;
4273 s->cur_prompt->name = dupstr("SSH key passphrase");
4274 add_prompt(s->cur_prompt,
4275 dupprintf("Passphrase for key \"%.100s\": ",
4276 s->publickey_comment), FALSE);
4277 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4280 crWaitUntil(!pktin);
4281 ret = get_userpass_input(s->cur_prompt, in, inlen);
4285 /* Failed to get a passphrase. Terminate. */
4286 free_prompts(s->cur_prompt);
4287 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4291 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4292 free_prompts(s->cur_prompt);
4295 * Try decrypting key with passphrase.
4297 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4298 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4301 smemclr(passphrase, strlen(passphrase));
4305 /* Correct passphrase. */
4306 got_passphrase = TRUE;
4307 } else if (ret == 0) {
4308 c_write_str(ssh, "Couldn't load private key from ");
4309 c_write_str(ssh, filename_to_str(s->keyfile));
4310 c_write_str(ssh, " (");
4311 c_write_str(ssh, error);
4312 c_write_str(ssh, ").\r\n");
4313 got_passphrase = FALSE;
4314 break; /* go and try something else */
4315 } else if (ret == -1) {
4316 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4317 got_passphrase = FALSE;
4320 assert(0 && "unexpected return from loadrsakey()");
4321 got_passphrase = FALSE; /* placate optimisers */
4325 if (got_passphrase) {
4328 * Send a public key attempt.
4330 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4331 PKT_BIGNUM, s->key.modulus, PKT_END);
4334 if (pktin->type == SSH1_SMSG_FAILURE) {
4335 c_write_str(ssh, "Server refused our public key.\r\n");
4336 continue; /* go and try something else */
4338 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4339 bombout(("Bizarre response to offer of public key"));
4345 unsigned char buffer[32];
4346 Bignum challenge, response;
4348 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4349 bombout(("Server's RSA challenge was badly formatted"));
4352 response = rsadecrypt(challenge, &s->key);
4353 freebn(s->key.private_exponent);/* burn the evidence */
4355 for (i = 0; i < 32; i++) {
4356 buffer[i] = bignum_byte(response, 31 - i);
4360 MD5Update(&md5c, buffer, 32);
4361 MD5Update(&md5c, s->session_id, 16);
4362 MD5Final(buffer, &md5c);
4364 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4365 PKT_DATA, buffer, 16, PKT_END);
4372 if (pktin->type == SSH1_SMSG_FAILURE) {
4373 if (flags & FLAG_VERBOSE)
4374 c_write_str(ssh, "Failed to authenticate with"
4375 " our public key.\r\n");
4376 continue; /* go and try something else */
4377 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4378 bombout(("Bizarre response to RSA authentication response"));
4382 break; /* we're through! */
4388 * Otherwise, try various forms of password-like authentication.
4390 s->cur_prompt = new_prompts(ssh->frontend);
4392 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4393 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4394 !s->tis_auth_refused) {
4395 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4396 logevent("Requested TIS authentication");
4397 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4399 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4400 logevent("TIS authentication declined");
4401 if (flags & FLAG_INTERACTIVE)
4402 c_write_str(ssh, "TIS authentication refused.\r\n");
4403 s->tis_auth_refused = 1;
4408 char *instr_suf, *prompt;
4410 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4412 bombout(("TIS challenge packet was badly formed"));
4415 logevent("Received TIS challenge");
4416 s->cur_prompt->to_server = TRUE;
4417 s->cur_prompt->name = dupstr("SSH TIS authentication");
4418 /* Prompt heuristic comes from OpenSSH */
4419 if (memchr(challenge, '\n', challengelen)) {
4420 instr_suf = dupstr("");
4421 prompt = dupprintf("%.*s", challengelen, challenge);
4423 instr_suf = dupprintf("%.*s", challengelen, challenge);
4424 prompt = dupstr("Response: ");
4426 s->cur_prompt->instruction =
4427 dupprintf("Using TIS authentication.%s%s",
4428 (*instr_suf) ? "\n" : "",
4430 s->cur_prompt->instr_reqd = TRUE;
4431 add_prompt(s->cur_prompt, prompt, FALSE);
4435 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4436 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4437 !s->ccard_auth_refused) {
4438 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4439 logevent("Requested CryptoCard authentication");
4440 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4442 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4443 logevent("CryptoCard authentication declined");
4444 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4445 s->ccard_auth_refused = 1;
4450 char *instr_suf, *prompt;
4452 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4454 bombout(("CryptoCard challenge packet was badly formed"));
4457 logevent("Received CryptoCard challenge");
4458 s->cur_prompt->to_server = TRUE;
4459 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4460 s->cur_prompt->name_reqd = FALSE;
4461 /* Prompt heuristic comes from OpenSSH */
4462 if (memchr(challenge, '\n', challengelen)) {
4463 instr_suf = dupstr("");
4464 prompt = dupprintf("%.*s", challengelen, challenge);
4466 instr_suf = dupprintf("%.*s", challengelen, challenge);
4467 prompt = dupstr("Response: ");
4469 s->cur_prompt->instruction =
4470 dupprintf("Using CryptoCard authentication.%s%s",
4471 (*instr_suf) ? "\n" : "",
4473 s->cur_prompt->instr_reqd = TRUE;
4474 add_prompt(s->cur_prompt, prompt, FALSE);
4478 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4479 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4480 bombout(("No supported authentication methods available"));
4483 s->cur_prompt->to_server = TRUE;
4484 s->cur_prompt->name = dupstr("SSH password");
4485 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4486 ssh->username, ssh->savedhost),
4491 * Show password prompt, having first obtained it via a TIS
4492 * or CryptoCard exchange if we're doing TIS or CryptoCard
4496 int ret; /* need not be kept over crReturn */
4497 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4500 crWaitUntil(!pktin);
4501 ret = get_userpass_input(s->cur_prompt, in, inlen);
4506 * Failed to get a password (for example
4507 * because one was supplied on the command line
4508 * which has already failed to work). Terminate.
4510 free_prompts(s->cur_prompt);
4511 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4516 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4518 * Defence against traffic analysis: we send a
4519 * whole bunch of packets containing strings of
4520 * different lengths. One of these strings is the
4521 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4522 * The others are all random data in
4523 * SSH1_MSG_IGNORE packets. This way a passive
4524 * listener can't tell which is the password, and
4525 * hence can't deduce the password length.
4527 * Anybody with a password length greater than 16
4528 * bytes is going to have enough entropy in their
4529 * password that a listener won't find it _that_
4530 * much help to know how long it is. So what we'll
4533 * - if password length < 16, we send 15 packets
4534 * containing string lengths 1 through 15
4536 * - otherwise, we let N be the nearest multiple
4537 * of 8 below the password length, and send 8
4538 * packets containing string lengths N through
4539 * N+7. This won't obscure the order of
4540 * magnitude of the password length, but it will
4541 * introduce a bit of extra uncertainty.
4543 * A few servers can't deal with SSH1_MSG_IGNORE, at
4544 * least in this context. For these servers, we need
4545 * an alternative defence. We make use of the fact
4546 * that the password is interpreted as a C string:
4547 * so we can append a NUL, then some random data.
4549 * A few servers can deal with neither SSH1_MSG_IGNORE
4550 * here _nor_ a padded password string.
4551 * For these servers we are left with no defences
4552 * against password length sniffing.
4554 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4555 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4557 * The server can deal with SSH1_MSG_IGNORE, so
4558 * we can use the primary defence.
4560 int bottom, top, pwlen, i;
4563 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4565 bottom = 0; /* zero length passwords are OK! :-) */
4568 bottom = pwlen & ~7;
4572 assert(pwlen >= bottom && pwlen <= top);
4574 randomstr = snewn(top + 1, char);
4576 for (i = bottom; i <= top; i++) {
4578 defer_packet(ssh, s->pwpkt_type,
4579 PKT_STR,s->cur_prompt->prompts[0]->result,
4582 for (j = 0; j < i; j++) {
4584 randomstr[j] = random_byte();
4585 } while (randomstr[j] == '\0');
4587 randomstr[i] = '\0';
4588 defer_packet(ssh, SSH1_MSG_IGNORE,
4589 PKT_STR, randomstr, PKT_END);
4592 logevent("Sending password with camouflage packets");
4593 ssh_pkt_defersend(ssh);
4596 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4598 * The server can't deal with SSH1_MSG_IGNORE
4599 * but can deal with padded passwords, so we
4600 * can use the secondary defence.
4606 len = strlen(s->cur_prompt->prompts[0]->result);
4607 if (len < sizeof(string)) {
4609 strcpy(string, s->cur_prompt->prompts[0]->result);
4610 len++; /* cover the zero byte */
4611 while (len < sizeof(string)) {
4612 string[len++] = (char) random_byte();
4615 ss = s->cur_prompt->prompts[0]->result;
4617 logevent("Sending length-padded password");
4618 send_packet(ssh, s->pwpkt_type,
4619 PKT_INT, len, PKT_DATA, ss, len,
4623 * The server is believed unable to cope with
4624 * any of our password camouflage methods.
4627 len = strlen(s->cur_prompt->prompts[0]->result);
4628 logevent("Sending unpadded password");
4629 send_packet(ssh, s->pwpkt_type,
4631 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4635 send_packet(ssh, s->pwpkt_type,
4636 PKT_STR, s->cur_prompt->prompts[0]->result,
4639 logevent("Sent password");
4640 free_prompts(s->cur_prompt);
4642 if (pktin->type == SSH1_SMSG_FAILURE) {
4643 if (flags & FLAG_VERBOSE)
4644 c_write_str(ssh, "Access denied\r\n");
4645 logevent("Authentication refused");
4646 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4647 bombout(("Strange packet received, type %d", pktin->type));
4653 if (s->publickey_blob) {
4654 sfree(s->publickey_blob);
4655 sfree(s->publickey_comment);
4658 logevent("Authentication successful");
4663 static void ssh_channel_try_eof(struct ssh_channel *c)
4666 assert(c->pending_eof); /* precondition for calling us */
4668 return; /* can't close: not even opened yet */
4669 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4670 return; /* can't send EOF: pending outgoing data */
4672 c->pending_eof = FALSE; /* we're about to send it */
4673 if (ssh->version == 1) {
4674 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4676 c->closes |= CLOSES_SENT_EOF;
4678 struct Packet *pktout;
4679 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4680 ssh2_pkt_adduint32(pktout, c->remoteid);
4681 ssh2_pkt_send(ssh, pktout);
4682 c->closes |= CLOSES_SENT_EOF;
4683 ssh2_channel_check_close(c);
4687 Conf *sshfwd_get_conf(struct ssh_channel *c)
4693 void sshfwd_write_eof(struct ssh_channel *c)
4697 if (ssh->state == SSH_STATE_CLOSED)
4700 if (c->closes & CLOSES_SENT_EOF)
4703 c->pending_eof = TRUE;
4704 ssh_channel_try_eof(c);
4707 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4711 if (ssh->state == SSH_STATE_CLOSED)
4716 x11_close(c->u.x11.xconn);
4717 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4721 case CHAN_SOCKDATA_DORMANT:
4722 pfd_close(c->u.pfd.pf);
4723 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4726 c->type = CHAN_ZOMBIE;
4727 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4729 ssh2_channel_check_close(c);
4732 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4736 if (ssh->state == SSH_STATE_CLOSED)
4739 if (ssh->version == 1) {
4740 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4741 PKT_INT, c->remoteid,
4742 PKT_INT, len, PKT_DATA, buf, len,
4745 * In SSH-1 we can return 0 here - implying that forwarded
4746 * connections are never individually throttled - because
4747 * the only circumstance that can cause throttling will be
4748 * the whole SSH connection backing up, in which case
4749 * _everything_ will be throttled as a whole.
4753 ssh2_add_channel_data(c, buf, len);
4754 return ssh2_try_send(c);
4758 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4763 if (ssh->state == SSH_STATE_CLOSED)
4766 if (ssh->version == 1) {
4767 buflimit = SSH1_BUFFER_LIMIT;
4769 buflimit = c->v.v2.locmaxwin;
4770 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4772 if (c->throttling_conn && bufsize <= buflimit) {
4773 c->throttling_conn = 0;
4774 ssh_throttle_conn(ssh, -1);
4778 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4780 struct queued_handler *qh = ssh->qhead;
4784 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4787 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4788 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4791 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4792 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4796 ssh->qhead = qh->next;
4798 if (ssh->qhead->msg1 > 0) {
4799 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4800 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4802 if (ssh->qhead->msg2 > 0) {
4803 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4804 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4807 ssh->qhead = ssh->qtail = NULL;
4810 qh->handler(ssh, pktin, qh->ctx);
4815 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4816 chandler_fn_t handler, void *ctx)
4818 struct queued_handler *qh;
4820 qh = snew(struct queued_handler);
4823 qh->handler = handler;
4827 if (ssh->qtail == NULL) {
4831 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4832 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4835 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4836 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4839 ssh->qtail->next = qh;
4844 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4846 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4848 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4849 SSH2_MSG_REQUEST_SUCCESS)) {
4850 logeventf(ssh, "Remote port forwarding from %s enabled",
4853 logeventf(ssh, "Remote port forwarding from %s refused",
4856 rpf = del234(ssh->rportfwds, pf);
4858 pf->pfrec->remote = NULL;
4863 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4866 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4869 pf->share_ctx = share_ctx;
4870 pf->shost = dupstr(shost);
4872 pf->sportdesc = NULL;
4873 if (!ssh->rportfwds) {
4874 assert(ssh->version == 2);
4875 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4877 if (add234(ssh->rportfwds, pf) != pf) {
4885 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4888 share_got_pkt_from_server(ctx, pktin->type,
4889 pktin->body, pktin->length);
4892 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4894 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4895 ssh_sharing_global_request_response, share_ctx);
4898 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4900 struct ssh_portfwd *epf;
4904 if (!ssh->portfwds) {
4905 ssh->portfwds = newtree234(ssh_portcmp);
4908 * Go through the existing port forwardings and tag them
4909 * with status==DESTROY. Any that we want to keep will be
4910 * re-enabled (status==KEEP) as we go through the
4911 * configuration and find out which bits are the same as
4914 struct ssh_portfwd *epf;
4916 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4917 epf->status = DESTROY;
4920 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4922 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4923 char *kp, *kp2, *vp, *vp2;
4924 char address_family, type;
4925 int sport,dport,sserv,dserv;
4926 char *sports, *dports, *saddr, *host;
4930 address_family = 'A';
4932 if (*kp == 'A' || *kp == '4' || *kp == '6')
4933 address_family = *kp++;
4934 if (*kp == 'L' || *kp == 'R')
4937 if ((kp2 = host_strchr(kp, ':')) != NULL) {
4939 * There's a colon in the middle of the source port
4940 * string, which means that the part before it is
4941 * actually a source address.
4943 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
4944 saddr = host_strduptrim(saddr_tmp);
4951 sport = atoi(sports);
4955 sport = net_service_lookup(sports);
4957 logeventf(ssh, "Service lookup failed for source"
4958 " port \"%s\"", sports);
4962 if (type == 'L' && !strcmp(val, "D")) {
4963 /* dynamic forwarding */
4970 /* ordinary forwarding */
4972 vp2 = vp + host_strcspn(vp, ":");
4973 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4977 dport = atoi(dports);
4981 dport = net_service_lookup(dports);
4983 logeventf(ssh, "Service lookup failed for destination"
4984 " port \"%s\"", dports);
4989 if (sport && dport) {
4990 /* Set up a description of the source port. */
4991 struct ssh_portfwd *pfrec, *epfrec;
4993 pfrec = snew(struct ssh_portfwd);
4995 pfrec->saddr = saddr;
4996 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4997 pfrec->sport = sport;
4998 pfrec->daddr = host;
4999 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5000 pfrec->dport = dport;
5001 pfrec->local = NULL;
5002 pfrec->remote = NULL;
5003 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5004 address_family == '6' ? ADDRTYPE_IPV6 :
5007 epfrec = add234(ssh->portfwds, pfrec);
5008 if (epfrec != pfrec) {
5009 if (epfrec->status == DESTROY) {
5011 * We already have a port forwarding up and running
5012 * with precisely these parameters. Hence, no need
5013 * to do anything; simply re-tag the existing one
5016 epfrec->status = KEEP;
5019 * Anything else indicates that there was a duplicate
5020 * in our input, which we'll silently ignore.
5022 free_portfwd(pfrec);
5024 pfrec->status = CREATE;
5033 * Now go through and destroy any port forwardings which were
5036 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5037 if (epf->status == DESTROY) {
5040 message = dupprintf("%s port forwarding from %s%s%d",
5041 epf->type == 'L' ? "local" :
5042 epf->type == 'R' ? "remote" : "dynamic",
5043 epf->saddr ? epf->saddr : "",
5044 epf->saddr ? ":" : "",
5047 if (epf->type != 'D') {
5048 char *msg2 = dupprintf("%s to %s:%d", message,
5049 epf->daddr, epf->dport);
5054 logeventf(ssh, "Cancelling %s", message);
5057 /* epf->remote or epf->local may be NULL if setting up a
5058 * forwarding failed. */
5060 struct ssh_rportfwd *rpf = epf->remote;
5061 struct Packet *pktout;
5064 * Cancel the port forwarding at the server
5067 if (ssh->version == 1) {
5069 * We cannot cancel listening ports on the
5070 * server side in SSH-1! There's no message
5071 * to support it. Instead, we simply remove
5072 * the rportfwd record from the local end
5073 * so that any connections the server tries
5074 * to make on it are rejected.
5077 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5078 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5079 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5081 ssh2_pkt_addstring(pktout, epf->saddr);
5082 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5083 /* XXX: rport_acceptall may not represent
5084 * what was used to open the original connection,
5085 * since it's reconfigurable. */
5086 ssh2_pkt_addstring(pktout, "");
5088 ssh2_pkt_addstring(pktout, "localhost");
5090 ssh2_pkt_adduint32(pktout, epf->sport);
5091 ssh2_pkt_send(ssh, pktout);
5094 del234(ssh->rportfwds, rpf);
5096 } else if (epf->local) {
5097 pfl_terminate(epf->local);
5100 delpos234(ssh->portfwds, i);
5102 i--; /* so we don't skip one in the list */
5106 * And finally, set up any new port forwardings (status==CREATE).
5108 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5109 if (epf->status == CREATE) {
5110 char *sportdesc, *dportdesc;
5111 sportdesc = dupprintf("%s%s%s%s%d%s",
5112 epf->saddr ? epf->saddr : "",
5113 epf->saddr ? ":" : "",
5114 epf->sserv ? epf->sserv : "",
5115 epf->sserv ? "(" : "",
5117 epf->sserv ? ")" : "");
5118 if (epf->type == 'D') {
5121 dportdesc = dupprintf("%s:%s%s%d%s",
5123 epf->dserv ? epf->dserv : "",
5124 epf->dserv ? "(" : "",
5126 epf->dserv ? ")" : "");
5129 if (epf->type == 'L') {
5130 char *err = pfl_listen(epf->daddr, epf->dport,
5131 epf->saddr, epf->sport,
5132 ssh, conf, &epf->local,
5133 epf->addressfamily);
5135 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5136 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5137 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5138 sportdesc, dportdesc,
5139 err ? " failed: " : "", err ? err : "");
5142 } else if (epf->type == 'D') {
5143 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5144 ssh, conf, &epf->local,
5145 epf->addressfamily);
5147 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5148 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5149 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5151 err ? " failed: " : "", err ? err : "");
5156 struct ssh_rportfwd *pf;
5159 * Ensure the remote port forwardings tree exists.
5161 if (!ssh->rportfwds) {
5162 if (ssh->version == 1)
5163 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5165 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5168 pf = snew(struct ssh_rportfwd);
5169 pf->share_ctx = NULL;
5170 pf->dhost = dupstr(epf->daddr);
5171 pf->dport = epf->dport;
5173 pf->shost = dupstr(epf->saddr);
5174 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5175 pf->shost = dupstr("");
5177 pf->shost = dupstr("localhost");
5179 pf->sport = epf->sport;
5180 if (add234(ssh->rportfwds, pf) != pf) {
5181 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5182 epf->daddr, epf->dport);
5185 logeventf(ssh, "Requesting remote port %s"
5186 " forward to %s", sportdesc, dportdesc);
5188 pf->sportdesc = sportdesc;
5193 if (ssh->version == 1) {
5194 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5195 PKT_INT, epf->sport,
5196 PKT_STR, epf->daddr,
5197 PKT_INT, epf->dport,
5199 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5201 ssh_rportfwd_succfail, pf);
5203 struct Packet *pktout;
5204 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5205 ssh2_pkt_addstring(pktout, "tcpip-forward");
5206 ssh2_pkt_addbool(pktout, 1);/* want reply */
5207 ssh2_pkt_addstring(pktout, pf->shost);
5208 ssh2_pkt_adduint32(pktout, pf->sport);
5209 ssh2_pkt_send(ssh, pktout);
5211 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5212 SSH2_MSG_REQUEST_FAILURE,
5213 ssh_rportfwd_succfail, pf);
5222 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5225 int stringlen, bufsize;
5227 ssh_pkt_getstring(pktin, &string, &stringlen);
5228 if (string == NULL) {
5229 bombout(("Incoming terminal data packet was badly formed"));
5233 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5235 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5236 ssh->v1_stdout_throttling = 1;
5237 ssh_throttle_conn(ssh, +1);
5241 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5243 /* Remote side is trying to open a channel to talk to our
5244 * X-Server. Give them back a local channel number. */
5245 struct ssh_channel *c;
5246 int remoteid = ssh_pkt_getuint32(pktin);
5248 logevent("Received X11 connect request");
5249 /* Refuse if X11 forwarding is disabled. */
5250 if (!ssh->X11_fwd_enabled) {
5251 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5252 PKT_INT, remoteid, PKT_END);
5253 logevent("Rejected X11 connect request");
5255 c = snew(struct ssh_channel);
5258 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5259 c->remoteid = remoteid;
5260 c->halfopen = FALSE;
5261 c->localid = alloc_channel_id(ssh);
5263 c->pending_eof = FALSE;
5264 c->throttling_conn = 0;
5265 c->type = CHAN_X11; /* identify channel type */
5266 add234(ssh->channels, c);
5267 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5268 PKT_INT, c->remoteid, PKT_INT,
5269 c->localid, PKT_END);
5270 logevent("Opened X11 forward channel");
5274 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5276 /* Remote side is trying to open a channel to talk to our
5277 * agent. Give them back a local channel number. */
5278 struct ssh_channel *c;
5279 int remoteid = ssh_pkt_getuint32(pktin);
5281 /* Refuse if agent forwarding is disabled. */
5282 if (!ssh->agentfwd_enabled) {
5283 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5284 PKT_INT, remoteid, PKT_END);
5286 c = snew(struct ssh_channel);
5288 c->remoteid = remoteid;
5289 c->halfopen = FALSE;
5290 c->localid = alloc_channel_id(ssh);
5292 c->pending_eof = FALSE;
5293 c->throttling_conn = 0;
5294 c->type = CHAN_AGENT; /* identify channel type */
5295 c->u.a.lensofar = 0;
5296 c->u.a.message = NULL;
5297 c->u.a.outstanding_requests = 0;
5298 add234(ssh->channels, c);
5299 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5300 PKT_INT, c->remoteid, PKT_INT, c->localid,
5305 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5307 /* Remote side is trying to open a channel to talk to a
5308 * forwarded port. Give them back a local channel number. */
5309 struct ssh_rportfwd pf, *pfp;
5315 remoteid = ssh_pkt_getuint32(pktin);
5316 ssh_pkt_getstring(pktin, &host, &hostsize);
5317 port = ssh_pkt_getuint32(pktin);
5319 pf.dhost = dupprintf("%.*s", hostsize, host);
5321 pfp = find234(ssh->rportfwds, &pf, NULL);
5324 logeventf(ssh, "Rejected remote port open request for %s:%d",
5326 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5327 PKT_INT, remoteid, PKT_END);
5329 struct ssh_channel *c = snew(struct ssh_channel);
5332 logeventf(ssh, "Received remote port open request for %s:%d",
5334 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5335 c, ssh->conf, pfp->pfrec->addressfamily);
5337 logeventf(ssh, "Port open failed: %s", err);
5340 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5341 PKT_INT, remoteid, PKT_END);
5343 c->remoteid = remoteid;
5344 c->halfopen = FALSE;
5345 c->localid = alloc_channel_id(ssh);
5347 c->pending_eof = FALSE;
5348 c->throttling_conn = 0;
5349 c->type = CHAN_SOCKDATA; /* identify channel type */
5350 add234(ssh->channels, c);
5351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5352 PKT_INT, c->remoteid, PKT_INT,
5353 c->localid, PKT_END);
5354 logevent("Forwarded port opened successfully");
5361 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5363 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5364 unsigned int localid = ssh_pkt_getuint32(pktin);
5365 struct ssh_channel *c;
5367 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5368 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5369 c->remoteid = localid;
5370 c->halfopen = FALSE;
5371 c->type = CHAN_SOCKDATA;
5372 c->throttling_conn = 0;
5373 pfd_confirm(c->u.pfd.pf);
5376 if (c && c->pending_eof) {
5378 * We have a pending close on this channel,
5379 * which we decided on before the server acked
5380 * the channel open. So now we know the
5381 * remoteid, we can close it again.
5383 ssh_channel_try_eof(c);
5387 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5389 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5390 struct ssh_channel *c;
5392 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5393 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5394 logevent("Forwarded connection refused by server");
5395 pfd_close(c->u.pfd.pf);
5396 del234(ssh->channels, c);
5401 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5403 /* Remote side closes a channel. */
5404 unsigned i = ssh_pkt_getuint32(pktin);
5405 struct ssh_channel *c;
5406 c = find234(ssh->channels, &i, ssh_channelfind);
5407 if (c && !c->halfopen) {
5409 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5410 !(c->closes & CLOSES_RCVD_EOF)) {
5412 * Received CHANNEL_CLOSE, which we translate into
5415 int send_close = FALSE;
5417 c->closes |= CLOSES_RCVD_EOF;
5422 x11_send_eof(c->u.x11.xconn);
5428 pfd_send_eof(c->u.pfd.pf);
5437 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5438 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5440 c->closes |= CLOSES_SENT_EOF;
5444 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5445 !(c->closes & CLOSES_RCVD_CLOSE)) {
5447 if (!(c->closes & CLOSES_SENT_EOF)) {
5448 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5449 " for which we never sent CHANNEL_CLOSE\n", i));
5452 c->closes |= CLOSES_RCVD_CLOSE;
5455 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5456 !(c->closes & CLOSES_SENT_CLOSE)) {
5457 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5458 PKT_INT, c->remoteid, PKT_END);
5459 c->closes |= CLOSES_SENT_CLOSE;
5462 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5463 ssh_channel_destroy(c);
5465 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5466 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5467 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5472 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5474 /* Data sent down one of our channels. */
5475 int i = ssh_pkt_getuint32(pktin);
5478 struct ssh_channel *c;
5480 ssh_pkt_getstring(pktin, &p, &len);
5482 c = find234(ssh->channels, &i, ssh_channelfind);
5487 bufsize = x11_send(c->u.x11.xconn, p, len);
5490 bufsize = pfd_send(c->u.pfd.pf, p, len);
5493 /* Data for an agent message. Buffer it. */
5495 if (c->u.a.lensofar < 4) {
5496 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5497 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5501 c->u.a.lensofar += l;
5503 if (c->u.a.lensofar == 4) {
5505 4 + GET_32BIT(c->u.a.msglen);
5506 c->u.a.message = snewn(c->u.a.totallen,
5508 memcpy(c->u.a.message, c->u.a.msglen, 4);
5510 if (c->u.a.lensofar >= 4 && len > 0) {
5512 min(c->u.a.totallen - c->u.a.lensofar,
5514 memcpy(c->u.a.message + c->u.a.lensofar, p,
5518 c->u.a.lensofar += l;
5520 if (c->u.a.lensofar == c->u.a.totallen) {
5523 c->u.a.outstanding_requests++;
5524 if (agent_query(c->u.a.message,
5527 ssh_agentf_callback, c))
5528 ssh_agentf_callback(c, reply, replylen);
5529 sfree(c->u.a.message);
5530 c->u.a.lensofar = 0;
5533 bufsize = 0; /* agent channels never back up */
5536 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5537 c->throttling_conn = 1;
5538 ssh_throttle_conn(ssh, +1);
5543 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5545 ssh->exitcode = ssh_pkt_getuint32(pktin);
5546 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5547 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5549 * In case `helpful' firewalls or proxies tack
5550 * extra human-readable text on the end of the
5551 * session which we might mistake for another
5552 * encrypted packet, we close the session once
5553 * we've sent EXIT_CONFIRMATION.
5555 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5558 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5559 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5561 struct Packet *pktout = (struct Packet *)data;
5563 unsigned int arg = 0;
5564 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5565 if (i == lenof(ssh_ttymodes)) return;
5566 switch (ssh_ttymodes[i].type) {
5568 arg = ssh_tty_parse_specchar(val);
5571 arg = ssh_tty_parse_boolean(val);
5574 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5575 ssh2_pkt_addbyte(pktout, arg);
5578 int ssh_agent_forwarding_permitted(Ssh ssh)
5580 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5583 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5584 struct Packet *pktin)
5586 crBegin(ssh->do_ssh1_connection_crstate);
5588 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5589 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5590 ssh1_smsg_stdout_stderr_data;
5592 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5593 ssh1_msg_channel_open_confirmation;
5594 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5595 ssh1_msg_channel_open_failure;
5596 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5597 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5598 ssh1_msg_channel_close;
5599 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5600 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5602 if (ssh_agent_forwarding_permitted(ssh)) {
5603 logevent("Requesting agent forwarding");
5604 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5608 if (pktin->type != SSH1_SMSG_SUCCESS
5609 && pktin->type != SSH1_SMSG_FAILURE) {
5610 bombout(("Protocol confusion"));
5612 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5613 logevent("Agent forwarding refused");
5615 logevent("Agent forwarding enabled");
5616 ssh->agentfwd_enabled = TRUE;
5617 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5621 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5623 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5625 if (!ssh->x11disp) {
5626 /* FIXME: return an error message from x11_setup_display */
5627 logevent("X11 forwarding not enabled: unable to"
5628 " initialise X display");
5630 ssh->x11auth = x11_invent_fake_auth
5631 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5632 ssh->x11auth->disp = ssh->x11disp;
5634 logevent("Requesting X11 forwarding");
5635 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5636 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5637 PKT_STR, ssh->x11auth->protoname,
5638 PKT_STR, ssh->x11auth->datastring,
5639 PKT_INT, ssh->x11disp->screennum,
5642 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5643 PKT_STR, ssh->x11auth->protoname,
5644 PKT_STR, ssh->x11auth->datastring,
5650 if (pktin->type != SSH1_SMSG_SUCCESS
5651 && pktin->type != SSH1_SMSG_FAILURE) {
5652 bombout(("Protocol confusion"));
5654 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5655 logevent("X11 forwarding refused");
5657 logevent("X11 forwarding enabled");
5658 ssh->X11_fwd_enabled = TRUE;
5659 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5664 ssh_setup_portfwd(ssh, ssh->conf);
5665 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5667 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5669 /* Unpick the terminal-speed string. */
5670 /* XXX perhaps we should allow no speeds to be sent. */
5671 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5672 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5673 /* Send the pty request. */
5674 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5675 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5676 ssh_pkt_adduint32(pkt, ssh->term_height);
5677 ssh_pkt_adduint32(pkt, ssh->term_width);
5678 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5679 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5680 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5681 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5682 ssh_pkt_adduint32(pkt, ssh->ispeed);
5683 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5684 ssh_pkt_adduint32(pkt, ssh->ospeed);
5685 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5687 ssh->state = SSH_STATE_INTERMED;
5691 if (pktin->type != SSH1_SMSG_SUCCESS
5692 && pktin->type != SSH1_SMSG_FAILURE) {
5693 bombout(("Protocol confusion"));
5695 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5696 c_write_str(ssh, "Server refused to allocate pty\r\n");
5697 ssh->editing = ssh->echoing = 1;
5699 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5700 ssh->ospeed, ssh->ispeed);
5701 ssh->got_pty = TRUE;
5704 ssh->editing = ssh->echoing = 1;
5707 if (conf_get_int(ssh->conf, CONF_compression)) {
5708 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5712 if (pktin->type != SSH1_SMSG_SUCCESS
5713 && pktin->type != SSH1_SMSG_FAILURE) {
5714 bombout(("Protocol confusion"));
5716 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5717 c_write_str(ssh, "Server refused to compress\r\n");
5719 logevent("Started compression");
5720 ssh->v1_compressing = TRUE;
5721 ssh->cs_comp_ctx = zlib_compress_init();
5722 logevent("Initialised zlib (RFC1950) compression");
5723 ssh->sc_comp_ctx = zlib_decompress_init();
5724 logevent("Initialised zlib (RFC1950) decompression");
5728 * Start the shell or command.
5730 * Special case: if the first-choice command is an SSH-2
5731 * subsystem (hence not usable here) and the second choice
5732 * exists, we fall straight back to that.
5735 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5737 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5738 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5739 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5740 ssh->fallback_cmd = TRUE;
5743 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5745 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5746 logevent("Started session");
5749 ssh->state = SSH_STATE_SESSION;
5750 if (ssh->size_needed)
5751 ssh_size(ssh, ssh->term_width, ssh->term_height);
5752 if (ssh->eof_needed)
5753 ssh_special(ssh, TS_EOF);
5756 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5758 ssh->channels = newtree234(ssh_channelcmp);
5762 * By this point, most incoming packets are already being
5763 * handled by the dispatch table, and we need only pay
5764 * attention to the unusual ones.
5769 if (pktin->type == SSH1_SMSG_SUCCESS) {
5770 /* may be from EXEC_SHELL on some servers */
5771 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5772 /* may be from EXEC_SHELL on some servers
5773 * if no pty is available or in other odd cases. Ignore */
5775 bombout(("Strange packet received: type %d", pktin->type));
5780 int len = min(inlen, 512);
5781 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5782 PKT_INT, len, PKT_DATA, in, len,
5794 * Handle the top-level SSH-2 protocol.
5796 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5801 ssh_pkt_getstring(pktin, &msg, &msglen);
5802 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5805 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5807 /* log reason code in disconnect message */
5811 ssh_pkt_getstring(pktin, &msg, &msglen);
5812 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5815 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5817 /* Do nothing, because we're ignoring it! Duhh. */
5820 static void ssh1_protocol_setup(Ssh ssh)
5825 * Most messages are handled by the coroutines.
5827 for (i = 0; i < 256; i++)
5828 ssh->packet_dispatch[i] = NULL;
5831 * These special message types we install handlers for.
5833 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5834 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5835 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5838 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5839 struct Packet *pktin)
5841 unsigned char *in=(unsigned char*)vin;
5842 if (ssh->state == SSH_STATE_CLOSED)
5845 if (pktin && ssh->packet_dispatch[pktin->type]) {
5846 ssh->packet_dispatch[pktin->type](ssh, pktin);
5850 if (!ssh->protocol_initial_phase_done) {
5851 if (do_ssh1_login(ssh, in, inlen, pktin))
5852 ssh->protocol_initial_phase_done = TRUE;
5857 do_ssh1_connection(ssh, in, inlen, pktin);
5861 * Utility routine for decoding comma-separated strings in KEXINIT.
5863 static int in_commasep_string(char *needle, char *haystack, int haylen)
5866 if (!needle || !haystack) /* protect against null pointers */
5868 needlen = strlen(needle);
5871 * Is it at the start of the string?
5873 if (haylen >= needlen && /* haystack is long enough */
5874 !memcmp(needle, haystack, needlen) && /* initial match */
5875 (haylen == needlen || haystack[needlen] == ',')
5876 /* either , or EOS follows */
5880 * If not, search for the next comma and resume after that.
5881 * If no comma found, terminate.
5883 while (haylen > 0 && *haystack != ',')
5884 haylen--, haystack++;
5887 haylen--, haystack++; /* skip over comma itself */
5892 * Similar routine for checking whether we have the first string in a list.
5894 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5897 if (!needle || !haystack) /* protect against null pointers */
5899 needlen = strlen(needle);
5901 * Is it at the start of the string?
5903 if (haylen >= needlen && /* haystack is long enough */
5904 !memcmp(needle, haystack, needlen) && /* initial match */
5905 (haylen == needlen || haystack[needlen] == ',')
5906 /* either , or EOS follows */
5914 * SSH-2 key creation method.
5915 * (Currently assumes 2 lots of any hash are sufficient to generate
5916 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5918 #define SSH2_MKKEY_ITERS (2)
5919 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5920 unsigned char *keyspace)
5922 const struct ssh_hash *h = ssh->kex->hash;
5924 /* First hlen bytes. */
5926 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5927 hash_mpint(h, s, K);
5928 h->bytes(s, H, h->hlen);
5929 h->bytes(s, &chr, 1);
5930 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5931 h->final(s, keyspace);
5932 /* Next hlen bytes. */
5934 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5935 hash_mpint(h, s, K);
5936 h->bytes(s, H, h->hlen);
5937 h->bytes(s, keyspace, h->hlen);
5938 h->final(s, keyspace + h->hlen);
5942 * Handle the SSH-2 transport layer.
5944 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5945 struct Packet *pktin)
5947 unsigned char *in = (unsigned char *)vin;
5948 struct do_ssh2_transport_state {
5950 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5951 Bignum p, g, e, f, K;
5954 int kex_init_value, kex_reply_value;
5955 const struct ssh_mac **maclist;
5957 const struct ssh2_cipher *cscipher_tobe;
5958 const struct ssh2_cipher *sccipher_tobe;
5959 const struct ssh_mac *csmac_tobe;
5960 const struct ssh_mac *scmac_tobe;
5961 const struct ssh_compress *cscomp_tobe;
5962 const struct ssh_compress *sccomp_tobe;
5963 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5964 int hostkeylen, siglen, rsakeylen;
5965 void *hkey; /* actual host key */
5966 void *rsakey; /* for RSA kex */
5967 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5968 int n_preferred_kex;
5969 const struct ssh_kexes *preferred_kex[KEX_MAX];
5970 int n_preferred_ciphers;
5971 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5972 const struct ssh_compress *preferred_comp;
5973 int userauth_succeeded; /* for delayed compression */
5974 int pending_compression;
5975 int got_session_id, activated_authconn;
5976 struct Packet *pktout;
5981 crState(do_ssh2_transport_state);
5983 assert(!ssh->bare_connection);
5987 s->cscipher_tobe = s->sccipher_tobe = NULL;
5988 s->csmac_tobe = s->scmac_tobe = NULL;
5989 s->cscomp_tobe = s->sccomp_tobe = NULL;
5991 s->got_session_id = s->activated_authconn = FALSE;
5992 s->userauth_succeeded = FALSE;
5993 s->pending_compression = FALSE;
5996 * Be prepared to work around the buggy MAC problem.
5998 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5999 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6001 s->maclist = macs, s->nmacs = lenof(macs);
6004 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6006 int i, j, k, commalist_started;
6009 * Set up the preferred key exchange. (NULL => warn below here)
6011 s->n_preferred_kex = 0;
6012 for (i = 0; i < KEX_MAX; i++) {
6013 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6015 s->preferred_kex[s->n_preferred_kex++] =
6016 &ssh_diffiehellman_gex;
6019 s->preferred_kex[s->n_preferred_kex++] =
6020 &ssh_diffiehellman_group14;
6023 s->preferred_kex[s->n_preferred_kex++] =
6024 &ssh_diffiehellman_group1;
6027 s->preferred_kex[s->n_preferred_kex++] =
6031 /* Flag for later. Don't bother if it's the last in
6033 if (i < KEX_MAX - 1) {
6034 s->preferred_kex[s->n_preferred_kex++] = NULL;
6041 * Set up the preferred ciphers. (NULL => warn below here)
6043 s->n_preferred_ciphers = 0;
6044 for (i = 0; i < CIPHER_MAX; i++) {
6045 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6046 case CIPHER_BLOWFISH:
6047 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6050 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6051 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6055 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6058 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6060 case CIPHER_ARCFOUR:
6061 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6064 /* Flag for later. Don't bother if it's the last in
6066 if (i < CIPHER_MAX - 1) {
6067 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6074 * Set up preferred compression.
6076 if (conf_get_int(ssh->conf, CONF_compression))
6077 s->preferred_comp = &ssh_zlib;
6079 s->preferred_comp = &ssh_comp_none;
6082 * Enable queueing of outgoing auth- or connection-layer
6083 * packets while we are in the middle of a key exchange.
6085 ssh->queueing = TRUE;
6088 * Flag that KEX is in progress.
6090 ssh->kex_in_progress = TRUE;
6093 * Construct and send our key exchange packet.
6095 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6096 for (i = 0; i < 16; i++)
6097 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6098 /* List key exchange algorithms. */
6099 ssh2_pkt_addstring_start(s->pktout);
6100 commalist_started = 0;
6101 for (i = 0; i < s->n_preferred_kex; i++) {
6102 const struct ssh_kexes *k = s->preferred_kex[i];
6103 if (!k) continue; /* warning flag */
6104 for (j = 0; j < k->nkexes; j++) {
6105 if (commalist_started)
6106 ssh2_pkt_addstring_str(s->pktout, ",");
6107 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6108 commalist_started = 1;
6111 /* List server host key algorithms. */
6112 if (!s->got_session_id) {
6114 * In the first key exchange, we list all the algorithms
6115 * we're prepared to cope with.
6117 ssh2_pkt_addstring_start(s->pktout);
6118 for (i = 0; i < lenof(hostkey_algs); i++) {
6119 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6120 if (i < lenof(hostkey_algs) - 1)
6121 ssh2_pkt_addstring_str(s->pktout, ",");
6125 * In subsequent key exchanges, we list only the kex
6126 * algorithm that was selected in the first key exchange,
6127 * so that we keep getting the same host key and hence
6128 * don't have to interrupt the user's session to ask for
6132 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6134 /* List encryption algorithms (client->server then server->client). */
6135 for (k = 0; k < 2; k++) {
6136 ssh2_pkt_addstring_start(s->pktout);
6137 commalist_started = 0;
6138 for (i = 0; i < s->n_preferred_ciphers; i++) {
6139 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6140 if (!c) continue; /* warning flag */
6141 for (j = 0; j < c->nciphers; j++) {
6142 if (commalist_started)
6143 ssh2_pkt_addstring_str(s->pktout, ",");
6144 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6145 commalist_started = 1;
6149 /* List MAC algorithms (client->server then server->client). */
6150 for (j = 0; j < 2; j++) {
6151 ssh2_pkt_addstring_start(s->pktout);
6152 for (i = 0; i < s->nmacs; i++) {
6153 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6154 if (i < s->nmacs - 1)
6155 ssh2_pkt_addstring_str(s->pktout, ",");
6158 /* List client->server compression algorithms,
6159 * then server->client compression algorithms. (We use the
6160 * same set twice.) */
6161 for (j = 0; j < 2; j++) {
6162 ssh2_pkt_addstring_start(s->pktout);
6163 assert(lenof(compressions) > 1);
6164 /* Prefer non-delayed versions */
6165 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6166 /* We don't even list delayed versions of algorithms until
6167 * they're allowed to be used, to avoid a race. See the end of
6169 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6170 ssh2_pkt_addstring_str(s->pktout, ",");
6171 ssh2_pkt_addstring_str(s->pktout,
6172 s->preferred_comp->delayed_name);
6174 for (i = 0; i < lenof(compressions); i++) {
6175 const struct ssh_compress *c = compressions[i];
6176 if (c != s->preferred_comp) {
6177 ssh2_pkt_addstring_str(s->pktout, ",");
6178 ssh2_pkt_addstring_str(s->pktout, c->name);
6179 if (s->userauth_succeeded && c->delayed_name) {
6180 ssh2_pkt_addstring_str(s->pktout, ",");
6181 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6186 /* List client->server languages. Empty list. */
6187 ssh2_pkt_addstring_start(s->pktout);
6188 /* List server->client languages. Empty list. */
6189 ssh2_pkt_addstring_start(s->pktout);
6190 /* First KEX packet does _not_ follow, because we're not that brave. */
6191 ssh2_pkt_addbool(s->pktout, FALSE);
6193 ssh2_pkt_adduint32(s->pktout, 0);
6196 s->our_kexinitlen = s->pktout->length - 5;
6197 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6198 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6200 ssh2_pkt_send_noqueue(ssh, s->pktout);
6203 crWaitUntilV(pktin);
6206 * Now examine the other side's KEXINIT to see what we're up
6210 char *str, *preferred;
6213 if (pktin->type != SSH2_MSG_KEXINIT) {
6214 bombout(("expected key exchange packet from server"));
6218 ssh->hostkey = NULL;
6219 s->cscipher_tobe = NULL;
6220 s->sccipher_tobe = NULL;
6221 s->csmac_tobe = NULL;
6222 s->scmac_tobe = NULL;
6223 s->cscomp_tobe = NULL;
6224 s->sccomp_tobe = NULL;
6225 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6227 pktin->savedpos += 16; /* skip garbage cookie */
6228 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6231 for (i = 0; i < s->n_preferred_kex; i++) {
6232 const struct ssh_kexes *k = s->preferred_kex[i];
6236 for (j = 0; j < k->nkexes; j++) {
6237 if (!preferred) preferred = k->list[j]->name;
6238 if (in_commasep_string(k->list[j]->name, str, len)) {
6239 ssh->kex = k->list[j];
6248 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
6249 str ? str : "(null)"));
6253 * Note that the server's guess is considered wrong if it doesn't match
6254 * the first algorithm in our list, even if it's still the algorithm
6257 s->guessok = first_in_commasep_string(preferred, str, len);
6258 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6259 for (i = 0; i < lenof(hostkey_algs); i++) {
6260 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6261 ssh->hostkey = hostkey_algs[i];
6265 if (!ssh->hostkey) {
6266 bombout(("Couldn't agree a host key algorithm (available: %s)",
6267 str ? str : "(null)"));
6271 s->guessok = s->guessok &&
6272 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6273 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6274 for (i = 0; i < s->n_preferred_ciphers; i++) {
6275 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6277 s->warn_cscipher = TRUE;
6279 for (j = 0; j < c->nciphers; j++) {
6280 if (in_commasep_string(c->list[j]->name, str, len)) {
6281 s->cscipher_tobe = c->list[j];
6286 if (s->cscipher_tobe)
6289 if (!s->cscipher_tobe) {
6290 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
6291 str ? str : "(null)"));
6295 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6296 for (i = 0; i < s->n_preferred_ciphers; i++) {
6297 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6299 s->warn_sccipher = TRUE;
6301 for (j = 0; j < c->nciphers; j++) {
6302 if (in_commasep_string(c->list[j]->name, str, len)) {
6303 s->sccipher_tobe = c->list[j];
6308 if (s->sccipher_tobe)
6311 if (!s->sccipher_tobe) {
6312 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
6313 str ? str : "(null)"));
6317 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6318 for (i = 0; i < s->nmacs; i++) {
6319 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6320 s->csmac_tobe = s->maclist[i];
6324 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6325 for (i = 0; i < s->nmacs; i++) {
6326 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6327 s->scmac_tobe = s->maclist[i];
6331 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6332 for (i = 0; i < lenof(compressions) + 1; i++) {
6333 const struct ssh_compress *c =
6334 i == 0 ? s->preferred_comp : compressions[i - 1];
6335 if (in_commasep_string(c->name, str, len)) {
6338 } else if (in_commasep_string(c->delayed_name, str, len)) {
6339 if (s->userauth_succeeded) {
6343 s->pending_compression = TRUE; /* try this later */
6347 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6348 for (i = 0; i < lenof(compressions) + 1; i++) {
6349 const struct ssh_compress *c =
6350 i == 0 ? s->preferred_comp : compressions[i - 1];
6351 if (in_commasep_string(c->name, str, len)) {
6354 } else if (in_commasep_string(c->delayed_name, str, len)) {
6355 if (s->userauth_succeeded) {
6359 s->pending_compression = TRUE; /* try this later */
6363 if (s->pending_compression) {
6364 logevent("Server supports delayed compression; "
6365 "will try this later");
6367 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6368 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6369 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6371 ssh->exhash = ssh->kex->hash->init();
6372 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6373 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6374 hash_string(ssh->kex->hash, ssh->exhash,
6375 s->our_kexinit, s->our_kexinitlen);
6376 sfree(s->our_kexinit);
6377 /* Include the type byte in the hash of server's KEXINIT */
6378 hash_string(ssh->kex->hash, ssh->exhash,
6379 pktin->body - 1, pktin->length + 1);
6382 ssh_set_frozen(ssh, 1);
6383 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6385 ssh_dialog_callback, ssh);
6386 if (s->dlgret < 0) {
6390 bombout(("Unexpected data from server while"
6391 " waiting for user response"));
6394 } while (pktin || inlen > 0);
6395 s->dlgret = ssh->user_response;
6397 ssh_set_frozen(ssh, 0);
6398 if (s->dlgret == 0) {
6399 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6405 if (s->warn_cscipher) {
6406 ssh_set_frozen(ssh, 1);
6407 s->dlgret = askalg(ssh->frontend,
6408 "client-to-server cipher",
6409 s->cscipher_tobe->name,
6410 ssh_dialog_callback, ssh);
6411 if (s->dlgret < 0) {
6415 bombout(("Unexpected data from server while"
6416 " waiting for user response"));
6419 } while (pktin || inlen > 0);
6420 s->dlgret = ssh->user_response;
6422 ssh_set_frozen(ssh, 0);
6423 if (s->dlgret == 0) {
6424 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6430 if (s->warn_sccipher) {
6431 ssh_set_frozen(ssh, 1);
6432 s->dlgret = askalg(ssh->frontend,
6433 "server-to-client cipher",
6434 s->sccipher_tobe->name,
6435 ssh_dialog_callback, ssh);
6436 if (s->dlgret < 0) {
6440 bombout(("Unexpected data from server while"
6441 " waiting for user response"));
6444 } while (pktin || inlen > 0);
6445 s->dlgret = ssh->user_response;
6447 ssh_set_frozen(ssh, 0);
6448 if (s->dlgret == 0) {
6449 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6455 if (s->ignorepkt) /* first_kex_packet_follows */
6456 crWaitUntilV(pktin); /* Ignore packet */
6459 if (ssh->kex->main_type == KEXTYPE_DH) {
6461 * Work out the number of bits of key we will need from the
6462 * key exchange. We start with the maximum key length of
6468 csbits = s->cscipher_tobe->keylen;
6469 scbits = s->sccipher_tobe->keylen;
6470 s->nbits = (csbits > scbits ? csbits : scbits);
6472 /* The keys only have hlen-bit entropy, since they're based on
6473 * a hash. So cap the key size at hlen bits. */
6474 if (s->nbits > ssh->kex->hash->hlen * 8)
6475 s->nbits = ssh->kex->hash->hlen * 8;
6478 * If we're doing Diffie-Hellman group exchange, start by
6479 * requesting a group.
6481 if (!ssh->kex->pdata) {
6482 logevent("Doing Diffie-Hellman group exchange");
6483 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6485 * Work out how big a DH group we will need to allow that
6488 s->pbits = 512 << ((s->nbits - 1) / 64);
6489 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6490 ssh2_pkt_adduint32(s->pktout, s->pbits);
6491 ssh2_pkt_send_noqueue(ssh, s->pktout);
6493 crWaitUntilV(pktin);
6494 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6495 bombout(("expected key exchange group packet from server"));
6498 s->p = ssh2_pkt_getmp(pktin);
6499 s->g = ssh2_pkt_getmp(pktin);
6500 if (!s->p || !s->g) {
6501 bombout(("unable to read mp-ints from incoming group packet"));
6504 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6505 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6506 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6508 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6509 ssh->kex_ctx = dh_setup_group(ssh->kex);
6510 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6511 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6512 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6513 ssh->kex->groupname);
6516 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6517 ssh->kex->hash->text_name);
6519 * Now generate and send e for Diffie-Hellman.
6521 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6522 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6523 s->pktout = ssh2_pkt_init(s->kex_init_value);
6524 ssh2_pkt_addmp(s->pktout, s->e);
6525 ssh2_pkt_send_noqueue(ssh, s->pktout);
6527 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6528 crWaitUntilV(pktin);
6529 if (pktin->type != s->kex_reply_value) {
6530 bombout(("expected key exchange reply packet from server"));
6533 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6534 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6535 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6536 s->f = ssh2_pkt_getmp(pktin);
6538 bombout(("unable to parse key exchange reply packet"));
6541 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6543 s->K = dh_find_K(ssh->kex_ctx, s->f);
6545 /* We assume everything from now on will be quick, and it might
6546 * involve user interaction. */
6547 set_busy_status(ssh->frontend, BUSY_NOT);
6549 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6550 if (!ssh->kex->pdata) {
6551 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6552 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6553 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6555 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6556 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6558 dh_cleanup(ssh->kex_ctx);
6560 if (!ssh->kex->pdata) {
6565 logeventf(ssh, "Doing RSA key exchange with hash %s",
6566 ssh->kex->hash->text_name);
6567 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6569 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6572 crWaitUntilV(pktin);
6573 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6574 bombout(("expected RSA public key packet from server"));
6578 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6579 hash_string(ssh->kex->hash, ssh->exhash,
6580 s->hostkeydata, s->hostkeylen);
6581 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6585 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6586 s->rsakeydata = snewn(s->rsakeylen, char);
6587 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6590 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6592 sfree(s->rsakeydata);
6593 bombout(("unable to parse RSA public key from server"));
6597 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6600 * Next, set up a shared secret K, of precisely KLEN -
6601 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6602 * RSA key modulus and HLEN is the bit length of the hash
6606 int klen = ssh_rsakex_klen(s->rsakey);
6607 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6609 unsigned char *kstr1, *kstr2, *outstr;
6610 int kstr1len, kstr2len, outstrlen;
6612 s->K = bn_power_2(nbits - 1);
6614 for (i = 0; i < nbits; i++) {
6616 byte = random_byte();
6618 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6622 * Encode this as an mpint.
6624 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6625 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6626 PUT_32BIT(kstr2, kstr1len);
6627 memcpy(kstr2 + 4, kstr1, kstr1len);
6630 * Encrypt it with the given RSA key.
6632 outstrlen = (klen + 7) / 8;
6633 outstr = snewn(outstrlen, unsigned char);
6634 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6635 outstr, outstrlen, s->rsakey);
6638 * And send it off in a return packet.
6640 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6641 ssh2_pkt_addstring_start(s->pktout);
6642 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6643 ssh2_pkt_send_noqueue(ssh, s->pktout);
6645 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6652 ssh_rsakex_freekey(s->rsakey);
6654 crWaitUntilV(pktin);
6655 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6656 sfree(s->rsakeydata);
6657 bombout(("expected signature packet from server"));
6661 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6663 sfree(s->rsakeydata);
6666 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6667 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6668 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6670 ssh->kex_ctx = NULL;
6673 debug(("Exchange hash is:\n"));
6674 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6678 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6679 (char *)s->exchange_hash,
6680 ssh->kex->hash->hlen)) {
6681 bombout(("Server's host key did not match the signature supplied"));
6685 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6686 if (!s->got_session_id) {
6688 * Authenticate remote host: verify host key. (We've already
6689 * checked the signature of the exchange hash.)
6691 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6692 ssh_set_frozen(ssh, 1);
6693 s->dlgret = verify_ssh_host_key(ssh->frontend,
6694 ssh->savedhost, ssh->savedport,
6695 ssh->hostkey->keytype, s->keystr,
6697 ssh_dialog_callback, ssh);
6698 if (s->dlgret < 0) {
6702 bombout(("Unexpected data from server while waiting"
6703 " for user host key response"));
6706 } while (pktin || inlen > 0);
6707 s->dlgret = ssh->user_response;
6709 ssh_set_frozen(ssh, 0);
6710 if (s->dlgret == 0) {
6711 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6715 logevent("Host key fingerprint is:");
6716 logevent(s->fingerprint);
6717 sfree(s->fingerprint);
6719 * Save this host key, to check against the one presented in
6720 * subsequent rekeys.
6722 ssh->hostkey_str = s->keystr;
6725 * In a rekey, we never present an interactive host key
6726 * verification request to the user. Instead, we simply
6727 * enforce that the key we're seeing this time is identical to
6728 * the one we saw before.
6730 if (strcmp(ssh->hostkey_str, s->keystr)) {
6731 bombout(("Host key was different in repeat key exchange"));
6736 ssh->hostkey->freekey(s->hkey);
6739 * The exchange hash from the very first key exchange is also
6740 * the session id, used in session key construction and
6743 if (!s->got_session_id) {
6744 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6745 memcpy(ssh->v2_session_id, s->exchange_hash,
6746 sizeof(s->exchange_hash));
6747 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6748 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6749 s->got_session_id = TRUE;
6753 * Send SSH2_MSG_NEWKEYS.
6755 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6756 ssh2_pkt_send_noqueue(ssh, s->pktout);
6757 ssh->outgoing_data_size = 0; /* start counting from here */
6760 * We've sent client NEWKEYS, so create and initialise
6761 * client-to-server session keys.
6763 if (ssh->cs_cipher_ctx)
6764 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6765 ssh->cscipher = s->cscipher_tobe;
6766 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6768 if (ssh->cs_mac_ctx)
6769 ssh->csmac->free_context(ssh->cs_mac_ctx);
6770 ssh->csmac = s->csmac_tobe;
6771 ssh->cs_mac_ctx = ssh->csmac->make_context();
6773 if (ssh->cs_comp_ctx)
6774 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6775 ssh->cscomp = s->cscomp_tobe;
6776 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6779 * Set IVs on client-to-server keys. Here we use the exchange
6780 * hash from the _first_ key exchange.
6783 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6784 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6785 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6786 assert((ssh->cscipher->keylen+7) / 8 <=
6787 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6788 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6789 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6790 assert(ssh->cscipher->blksize <=
6791 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6792 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6793 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6794 assert(ssh->csmac->len <=
6795 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6796 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6797 smemclr(keyspace, sizeof(keyspace));
6800 logeventf(ssh, "Initialised %.200s client->server encryption",
6801 ssh->cscipher->text_name);
6802 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6803 ssh->csmac->text_name);
6804 if (ssh->cscomp->text_name)
6805 logeventf(ssh, "Initialised %s compression",
6806 ssh->cscomp->text_name);
6809 * Now our end of the key exchange is complete, we can send all
6810 * our queued higher-layer packets.
6812 ssh->queueing = FALSE;
6813 ssh2_pkt_queuesend(ssh);
6816 * Expect SSH2_MSG_NEWKEYS from server.
6818 crWaitUntilV(pktin);
6819 if (pktin->type != SSH2_MSG_NEWKEYS) {
6820 bombout(("expected new-keys packet from server"));
6823 ssh->incoming_data_size = 0; /* start counting from here */
6826 * We've seen server NEWKEYS, so create and initialise
6827 * server-to-client session keys.
6829 if (ssh->sc_cipher_ctx)
6830 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6831 ssh->sccipher = s->sccipher_tobe;
6832 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6834 if (ssh->sc_mac_ctx)
6835 ssh->scmac->free_context(ssh->sc_mac_ctx);
6836 ssh->scmac = s->scmac_tobe;
6837 ssh->sc_mac_ctx = ssh->scmac->make_context();
6839 if (ssh->sc_comp_ctx)
6840 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6841 ssh->sccomp = s->sccomp_tobe;
6842 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6845 * Set IVs on server-to-client keys. Here we use the exchange
6846 * hash from the _first_ key exchange.
6849 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6850 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6851 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6852 assert((ssh->sccipher->keylen+7) / 8 <=
6853 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6854 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6855 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6856 assert(ssh->sccipher->blksize <=
6857 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6858 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6859 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6860 assert(ssh->scmac->len <=
6861 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6862 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6863 smemclr(keyspace, sizeof(keyspace));
6865 logeventf(ssh, "Initialised %.200s server->client encryption",
6866 ssh->sccipher->text_name);
6867 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6868 ssh->scmac->text_name);
6869 if (ssh->sccomp->text_name)
6870 logeventf(ssh, "Initialised %s decompression",
6871 ssh->sccomp->text_name);
6874 * Free shared secret.
6879 * Key exchange is over. Loop straight back round if we have a
6880 * deferred rekey reason.
6882 if (ssh->deferred_rekey_reason) {
6883 logevent(ssh->deferred_rekey_reason);
6885 ssh->deferred_rekey_reason = NULL;
6886 goto begin_key_exchange;
6890 * Otherwise, schedule a timer for our next rekey.
6892 ssh->kex_in_progress = FALSE;
6893 ssh->last_rekey = GETTICKCOUNT();
6894 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6895 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6899 * Now we're encrypting. Begin returning 1 to the protocol main
6900 * function so that other things can run on top of the
6901 * transport. If we ever see a KEXINIT, we must go back to the
6904 * We _also_ go back to the start if we see pktin==NULL and
6905 * inlen negative, because this is a special signal meaning
6906 * `initiate client-driven rekey', and `in' contains a message
6907 * giving the reason for the rekey.
6909 * inlen==-1 means always initiate a rekey;
6910 * inlen==-2 means that userauth has completed successfully and
6911 * we should consider rekeying (for delayed compression).
6913 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6914 (!pktin && inlen < 0))) {
6916 if (!ssh->protocol_initial_phase_done) {
6917 ssh->protocol_initial_phase_done = TRUE;
6919 * Allow authconn to initialise itself.
6921 do_ssh2_authconn(ssh, NULL, 0, NULL);
6926 logevent("Server initiated key re-exchange");
6930 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6931 * delayed compression, if it's available.
6933 * draft-miller-secsh-compression-delayed-00 says that you
6934 * negotiate delayed compression in the first key exchange, and
6935 * both sides start compressing when the server has sent
6936 * USERAUTH_SUCCESS. This has a race condition -- the server
6937 * can't know when the client has seen it, and thus which incoming
6938 * packets it should treat as compressed.
6940 * Instead, we do the initial key exchange without offering the
6941 * delayed methods, but note if the server offers them; when we
6942 * get here, if a delayed method was available that was higher
6943 * on our list than what we got, we initiate a rekey in which we
6944 * _do_ list the delayed methods (and hopefully get it as a
6945 * result). Subsequent rekeys will do the same.
6947 assert(!s->userauth_succeeded); /* should only happen once */
6948 s->userauth_succeeded = TRUE;
6949 if (!s->pending_compression)
6950 /* Can't see any point rekeying. */
6951 goto wait_for_rekey; /* this is utterly horrid */
6952 /* else fall through to rekey... */
6953 s->pending_compression = FALSE;
6956 * Now we've decided to rekey.
6958 * Special case: if the server bug is set that doesn't
6959 * allow rekeying, we give a different log message and
6960 * continue waiting. (If such a server _initiates_ a rekey,
6961 * we process it anyway!)
6963 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6964 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6966 /* Reset the counters, so that at least this message doesn't
6967 * hit the event log _too_ often. */
6968 ssh->outgoing_data_size = 0;
6969 ssh->incoming_data_size = 0;
6970 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6972 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6975 goto wait_for_rekey; /* this is still utterly horrid */
6977 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6980 goto begin_key_exchange;
6986 * Add data to an SSH-2 channel output buffer.
6988 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6991 bufchain_add(&c->v.v2.outbuffer, buf, len);
6995 * Attempt to send data on an SSH-2 channel.
6997 static int ssh2_try_send(struct ssh_channel *c)
7000 struct Packet *pktout;
7003 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7006 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7007 if ((unsigned)len > c->v.v2.remwindow)
7008 len = c->v.v2.remwindow;
7009 if ((unsigned)len > c->v.v2.remmaxpkt)
7010 len = c->v.v2.remmaxpkt;
7011 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7012 ssh2_pkt_adduint32(pktout, c->remoteid);
7013 ssh2_pkt_addstring_start(pktout);
7014 ssh2_pkt_addstring_data(pktout, data, len);
7015 ssh2_pkt_send(ssh, pktout);
7016 bufchain_consume(&c->v.v2.outbuffer, len);
7017 c->v.v2.remwindow -= len;
7021 * After having sent as much data as we can, return the amount
7024 ret = bufchain_size(&c->v.v2.outbuffer);
7027 * And if there's no data pending but we need to send an EOF, send
7030 if (!ret && c->pending_eof)
7031 ssh_channel_try_eof(c);
7036 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7039 if (c->closes & CLOSES_SENT_EOF)
7040 return; /* don't send on channels we've EOFed */
7041 bufsize = ssh2_try_send(c);
7044 case CHAN_MAINSESSION:
7045 /* stdin need not receive an unthrottle
7046 * notification since it will be polled */
7049 x11_unthrottle(c->u.x11.xconn);
7052 /* agent sockets are request/response and need no
7053 * buffer management */
7056 pfd_unthrottle(c->u.pfd.pf);
7062 static int ssh_is_simple(Ssh ssh)
7065 * We use the 'simple' variant of the SSH protocol if we're asked
7066 * to, except not if we're also doing connection-sharing (either
7067 * tunnelling our packets over an upstream or expecting to be
7068 * tunnelled over ourselves), since then the assumption that we
7069 * have only one channel to worry about is not true after all.
7071 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7072 !ssh->bare_connection && !ssh->connshare);
7076 * Set up most of a new ssh_channel for SSH-2.
7078 static void ssh2_channel_init(struct ssh_channel *c)
7081 c->localid = alloc_channel_id(ssh);
7083 c->pending_eof = FALSE;
7084 c->throttling_conn = FALSE;
7085 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7086 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7087 c->v.v2.chanreq_head = NULL;
7088 c->v.v2.throttle_state = UNTHROTTLED;
7089 bufchain_init(&c->v.v2.outbuffer);
7093 * Construct the common parts of a CHANNEL_OPEN.
7095 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7097 struct Packet *pktout;
7099 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7100 ssh2_pkt_addstring(pktout, type);
7101 ssh2_pkt_adduint32(pktout, c->localid);
7102 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7103 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7108 * CHANNEL_FAILURE doesn't come with any indication of what message
7109 * caused it, so we have to keep track of the outstanding
7110 * CHANNEL_REQUESTs ourselves.
7112 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7113 cchandler_fn_t handler, void *ctx)
7115 struct outstanding_channel_request *ocr =
7116 snew(struct outstanding_channel_request);
7118 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7119 ocr->handler = handler;
7122 if (!c->v.v2.chanreq_head)
7123 c->v.v2.chanreq_head = ocr;
7125 c->v.v2.chanreq_tail->next = ocr;
7126 c->v.v2.chanreq_tail = ocr;
7130 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7131 * NULL then a reply will be requested and the handler will be called
7132 * when it arrives. The returned packet is ready to have any
7133 * request-specific data added and be sent. Note that if a handler is
7134 * provided, it's essential that the request actually be sent.
7136 * The handler will usually be passed the response packet in pktin. If
7137 * pktin is NULL, this means that no reply will ever be forthcoming
7138 * (e.g. because the entire connection is being destroyed, or because
7139 * the server initiated channel closure before we saw the response)
7140 * and the handler should free any storage it's holding.
7142 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7143 cchandler_fn_t handler, void *ctx)
7145 struct Packet *pktout;
7147 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7148 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7149 ssh2_pkt_adduint32(pktout, c->remoteid);
7150 ssh2_pkt_addstring(pktout, type);
7151 ssh2_pkt_addbool(pktout, handler != NULL);
7152 if (handler != NULL)
7153 ssh2_queue_chanreq_handler(c, handler, ctx);
7158 * Potentially enlarge the window on an SSH-2 channel.
7160 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7162 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7167 * Never send WINDOW_ADJUST for a channel that the remote side has
7168 * already sent EOF on; there's no point, since it won't be
7169 * sending any more data anyway. Ditto if _we've_ already sent
7172 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7176 * Also, never widen the window for an X11 channel when we're
7177 * still waiting to see its initial auth and may yet hand it off
7180 if (c->type == CHAN_X11 && c->u.x11.initial)
7184 * If the remote end has a habit of ignoring maxpkt, limit the
7185 * window so that it has no choice (assuming it doesn't ignore the
7188 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7189 newwin = OUR_V2_MAXPKT;
7192 * Only send a WINDOW_ADJUST if there's significantly more window
7193 * available than the other end thinks there is. This saves us
7194 * sending a WINDOW_ADJUST for every character in a shell session.
7196 * "Significant" is arbitrarily defined as half the window size.
7198 if (newwin / 2 >= c->v.v2.locwindow) {
7199 struct Packet *pktout;
7203 * In order to keep track of how much window the client
7204 * actually has available, we'd like it to acknowledge each
7205 * WINDOW_ADJUST. We can't do that directly, so we accompany
7206 * it with a CHANNEL_REQUEST that has to be acknowledged.
7208 * This is only necessary if we're opening the window wide.
7209 * If we're not, then throughput is being constrained by
7210 * something other than the maximum window size anyway.
7212 if (newwin == c->v.v2.locmaxwin &&
7213 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7214 up = snew(unsigned);
7215 *up = newwin - c->v.v2.locwindow;
7216 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7217 ssh2_handle_winadj_response, up);
7218 ssh2_pkt_send(ssh, pktout);
7220 if (c->v.v2.throttle_state != UNTHROTTLED)
7221 c->v.v2.throttle_state = UNTHROTTLING;
7223 /* Pretend the WINDOW_ADJUST was acked immediately. */
7224 c->v.v2.remlocwin = newwin;
7225 c->v.v2.throttle_state = THROTTLED;
7227 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7228 ssh2_pkt_adduint32(pktout, c->remoteid);
7229 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7230 ssh2_pkt_send(ssh, pktout);
7231 c->v.v2.locwindow = newwin;
7236 * Find the channel associated with a message. If there's no channel,
7237 * or it's not properly open, make a noise about it and return NULL.
7239 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7241 unsigned localid = ssh_pkt_getuint32(pktin);
7242 struct ssh_channel *c;
7244 c = find234(ssh->channels, &localid, ssh_channelfind);
7246 (c->type != CHAN_SHARING && c->halfopen &&
7247 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7248 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7249 char *buf = dupprintf("Received %s for %s channel %u",
7250 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7252 c ? "half-open" : "nonexistent", localid);
7253 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7260 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7261 struct Packet *pktin, void *ctx)
7263 unsigned *sizep = ctx;
7266 * Winadj responses should always be failures. However, at least
7267 * one server ("boks_sshd") is known to return SUCCESS for channel
7268 * requests it's never heard of, such as "winadj@putty". Raised
7269 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7270 * life, we don't worry about what kind of response we got.
7273 c->v.v2.remlocwin += *sizep;
7276 * winadj messages are only sent when the window is fully open, so
7277 * if we get an ack of one, we know any pending unthrottle is
7280 if (c->v.v2.throttle_state == UNTHROTTLING)
7281 c->v.v2.throttle_state = UNTHROTTLED;
7284 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7286 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7287 struct outstanding_channel_request *ocr;
7290 if (c->type == CHAN_SHARING) {
7291 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7292 pktin->body, pktin->length);
7295 ocr = c->v.v2.chanreq_head;
7297 ssh2_msg_unexpected(ssh, pktin);
7300 ocr->handler(c, pktin, ocr->ctx);
7301 c->v.v2.chanreq_head = ocr->next;
7304 * We may now initiate channel-closing procedures, if that
7305 * CHANNEL_REQUEST was the last thing outstanding before we send
7308 ssh2_channel_check_close(c);
7311 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7313 struct ssh_channel *c;
7314 c = ssh2_channel_msg(ssh, pktin);
7317 if (c->type == CHAN_SHARING) {
7318 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7319 pktin->body, pktin->length);
7322 if (!(c->closes & CLOSES_SENT_EOF)) {
7323 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7324 ssh2_try_send_and_unthrottle(ssh, c);
7328 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7332 struct ssh_channel *c;
7333 c = ssh2_channel_msg(ssh, pktin);
7336 if (c->type == CHAN_SHARING) {
7337 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7338 pktin->body, pktin->length);
7341 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7342 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7343 return; /* extended but not stderr */
7344 ssh_pkt_getstring(pktin, &data, &length);
7347 c->v.v2.locwindow -= length;
7348 c->v.v2.remlocwin -= length;
7350 case CHAN_MAINSESSION:
7352 from_backend(ssh->frontend, pktin->type ==
7353 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7357 bufsize = x11_send(c->u.x11.xconn, data, length);
7360 bufsize = pfd_send(c->u.pfd.pf, data, length);
7363 while (length > 0) {
7364 if (c->u.a.lensofar < 4) {
7365 unsigned int l = min(4 - c->u.a.lensofar,
7367 memcpy(c->u.a.msglen + c->u.a.lensofar,
7371 c->u.a.lensofar += l;
7373 if (c->u.a.lensofar == 4) {
7375 4 + GET_32BIT(c->u.a.msglen);
7376 c->u.a.message = snewn(c->u.a.totallen,
7378 memcpy(c->u.a.message, c->u.a.msglen, 4);
7380 if (c->u.a.lensofar >= 4 && length > 0) {
7382 min(c->u.a.totallen - c->u.a.lensofar,
7384 memcpy(c->u.a.message + c->u.a.lensofar,
7388 c->u.a.lensofar += l;
7390 if (c->u.a.lensofar == c->u.a.totallen) {
7393 c->u.a.outstanding_requests++;
7394 if (agent_query(c->u.a.message,
7397 ssh_agentf_callback, c))
7398 ssh_agentf_callback(c, reply, replylen);
7399 sfree(c->u.a.message);
7400 c->u.a.message = NULL;
7401 c->u.a.lensofar = 0;
7408 * If it looks like the remote end hit the end of its window,
7409 * and we didn't want it to do that, think about using a
7412 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7413 c->v.v2.locmaxwin < 0x40000000)
7414 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7416 * If we are not buffering too much data,
7417 * enlarge the window again at the remote side.
7418 * If we are buffering too much, we may still
7419 * need to adjust the window if the server's
7422 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7423 c->v.v2.locmaxwin - bufsize : 0);
7425 * If we're either buffering way too much data, or if we're
7426 * buffering anything at all and we're in "simple" mode,
7427 * throttle the whole channel.
7429 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7430 && !c->throttling_conn) {
7431 c->throttling_conn = 1;
7432 ssh_throttle_conn(ssh, +1);
7437 static void ssh_check_termination(Ssh ssh)
7439 if (ssh->version == 2 &&
7440 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7441 count234(ssh->channels) == 0 &&
7442 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7444 * We used to send SSH_MSG_DISCONNECT here, because I'd
7445 * believed that _every_ conforming SSH-2 connection had to
7446 * end with a disconnect being sent by at least one side;
7447 * apparently I was wrong and it's perfectly OK to
7448 * unceremoniously slam the connection shut when you're done,
7449 * and indeed OpenSSH feels this is more polite than sending a
7450 * DISCONNECT. So now we don't.
7452 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7456 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7458 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7461 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7463 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7464 ssh_check_termination(ssh);
7467 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7472 va_start(ap, logfmt);
7473 buf = dupvprintf(logfmt, ap);
7476 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7478 logeventf(ssh, "Connection sharing: %s", buf);
7482 static void ssh_channel_destroy(struct ssh_channel *c)
7487 case CHAN_MAINSESSION:
7488 ssh->mainchan = NULL;
7489 update_specials_menu(ssh->frontend);
7492 if (c->u.x11.xconn != NULL)
7493 x11_close(c->u.x11.xconn);
7494 logevent("Forwarded X11 connection terminated");
7497 sfree(c->u.a.message);
7500 if (c->u.pfd.pf != NULL)
7501 pfd_close(c->u.pfd.pf);
7502 logevent("Forwarded port closed");
7506 del234(ssh->channels, c);
7507 if (ssh->version == 2) {
7508 bufchain_clear(&c->v.v2.outbuffer);
7509 assert(c->v.v2.chanreq_head == NULL);
7514 * If that was the last channel left open, we might need to
7517 ssh_check_termination(ssh);
7520 static void ssh2_channel_check_close(struct ssh_channel *c)
7523 struct Packet *pktout;
7527 * If we've sent out our own CHANNEL_OPEN but not yet seen
7528 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7529 * it's too early to be sending close messages of any kind.
7534 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7535 c->type == CHAN_ZOMBIE) &&
7536 !c->v.v2.chanreq_head &&
7537 !(c->closes & CLOSES_SENT_CLOSE)) {
7539 * We have both sent and received EOF (or the channel is a
7540 * zombie), and we have no outstanding channel requests, which
7541 * means the channel is in final wind-up. But we haven't sent
7542 * CLOSE, so let's do so now.
7544 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7545 ssh2_pkt_adduint32(pktout, c->remoteid);
7546 ssh2_pkt_send(ssh, pktout);
7547 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7550 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7551 assert(c->v.v2.chanreq_head == NULL);
7553 * We have both sent and received CLOSE, which means we're
7554 * completely done with the channel.
7556 ssh_channel_destroy(c);
7560 static void ssh2_channel_got_eof(struct ssh_channel *c)
7562 if (c->closes & CLOSES_RCVD_EOF)
7563 return; /* already seen EOF */
7564 c->closes |= CLOSES_RCVD_EOF;
7566 if (c->type == CHAN_X11) {
7567 x11_send_eof(c->u.x11.xconn);
7568 } else if (c->type == CHAN_AGENT) {
7569 if (c->u.a.outstanding_requests == 0) {
7570 /* Manufacture an outgoing EOF in response to the incoming one. */
7571 sshfwd_write_eof(c);
7573 } else if (c->type == CHAN_SOCKDATA) {
7574 pfd_send_eof(c->u.pfd.pf);
7575 } else if (c->type == CHAN_MAINSESSION) {
7578 if (!ssh->sent_console_eof &&
7579 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7581 * Either from_backend_eof told us that the front end
7582 * wants us to close the outgoing side of the connection
7583 * as soon as we see EOF from the far end, or else we've
7584 * unilaterally decided to do that because we've allocated
7585 * a remote pty and hence EOF isn't a particularly
7586 * meaningful concept.
7588 sshfwd_write_eof(c);
7590 ssh->sent_console_eof = TRUE;
7593 ssh2_channel_check_close(c);
7596 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7598 struct ssh_channel *c;
7600 c = ssh2_channel_msg(ssh, pktin);
7603 if (c->type == CHAN_SHARING) {
7604 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7605 pktin->body, pktin->length);
7608 ssh2_channel_got_eof(c);
7611 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7613 struct ssh_channel *c;
7615 c = ssh2_channel_msg(ssh, pktin);
7618 if (c->type == CHAN_SHARING) {
7619 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7620 pktin->body, pktin->length);
7625 * When we receive CLOSE on a channel, we assume it comes with an
7626 * implied EOF if we haven't seen EOF yet.
7628 ssh2_channel_got_eof(c);
7630 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7632 * It also means we stop expecting to see replies to any
7633 * outstanding channel requests, so clean those up too.
7634 * (ssh_chanreq_init will enforce by assertion that we don't
7635 * subsequently put anything back on this list.)
7637 while (c->v.v2.chanreq_head) {
7638 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7639 ocr->handler(c, NULL, ocr->ctx);
7640 c->v.v2.chanreq_head = ocr->next;
7646 * And we also send an outgoing EOF, if we haven't already, on the
7647 * assumption that CLOSE is a pretty forceful announcement that
7648 * the remote side is doing away with the entire channel. (If it
7649 * had wanted to send us EOF and continue receiving data from us,
7650 * it would have just sent CHANNEL_EOF.)
7652 if (!(c->closes & CLOSES_SENT_EOF)) {
7654 * Make sure we don't read any more from whatever our local
7655 * data source is for this channel.
7658 case CHAN_MAINSESSION:
7659 ssh->send_ok = 0; /* stop trying to read from stdin */
7662 x11_override_throttle(c->u.x11.xconn, 1);
7665 pfd_override_throttle(c->u.pfd.pf, 1);
7670 * Abandon any buffered data we still wanted to send to this
7671 * channel. Receiving a CHANNEL_CLOSE is an indication that
7672 * the server really wants to get on and _destroy_ this
7673 * channel, and it isn't going to send us any further
7674 * WINDOW_ADJUSTs to permit us to send pending stuff.
7676 bufchain_clear(&c->v.v2.outbuffer);
7679 * Send outgoing EOF.
7681 sshfwd_write_eof(c);
7685 * Now process the actual close.
7687 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7688 c->closes |= CLOSES_RCVD_CLOSE;
7689 ssh2_channel_check_close(c);
7693 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7695 struct ssh_channel *c;
7697 c = ssh2_channel_msg(ssh, pktin);
7700 if (c->type == CHAN_SHARING) {
7701 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7702 pktin->body, pktin->length);
7705 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7706 c->remoteid = ssh_pkt_getuint32(pktin);
7707 c->halfopen = FALSE;
7708 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7709 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7711 if (c->type == CHAN_SOCKDATA_DORMANT) {
7712 c->type = CHAN_SOCKDATA;
7714 pfd_confirm(c->u.pfd.pf);
7715 } else if (c->type == CHAN_ZOMBIE) {
7717 * This case can occur if a local socket error occurred
7718 * between us sending out CHANNEL_OPEN and receiving
7719 * OPEN_CONFIRMATION. In this case, all we can do is
7720 * immediately initiate close proceedings now that we know the
7721 * server's id to put in the close message.
7723 ssh2_channel_check_close(c);
7726 * We never expect to receive OPEN_CONFIRMATION for any
7727 * *other* channel type (since only local-to-remote port
7728 * forwardings cause us to send CHANNEL_OPEN after the main
7729 * channel is live - all other auxiliary channel types are
7730 * initiated from the server end). It's safe to enforce this
7731 * by assertion rather than by ssh_disconnect, because the
7732 * real point is that we never constructed a half-open channel
7733 * structure in the first place with any type other than the
7736 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7740 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7743 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7745 static const char *const reasons[] = {
7746 "<unknown reason code>",
7747 "Administratively prohibited",
7749 "Unknown channel type",
7750 "Resource shortage",
7752 unsigned reason_code;
7753 char *reason_string;
7755 struct ssh_channel *c;
7757 c = ssh2_channel_msg(ssh, pktin);
7760 if (c->type == CHAN_SHARING) {
7761 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7762 pktin->body, pktin->length);
7765 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7767 if (c->type == CHAN_SOCKDATA_DORMANT) {
7768 reason_code = ssh_pkt_getuint32(pktin);
7769 if (reason_code >= lenof(reasons))
7770 reason_code = 0; /* ensure reasons[reason_code] in range */
7771 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7772 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7773 reasons[reason_code], reason_length, reason_string);
7775 pfd_close(c->u.pfd.pf);
7776 } else if (c->type == CHAN_ZOMBIE) {
7778 * This case can occur if a local socket error occurred
7779 * between us sending out CHANNEL_OPEN and receiving
7780 * OPEN_FAILURE. In this case, we need do nothing except allow
7781 * the code below to throw the half-open channel away.
7785 * We never expect to receive OPEN_FAILURE for any *other*
7786 * channel type (since only local-to-remote port forwardings
7787 * cause us to send CHANNEL_OPEN after the main channel is
7788 * live - all other auxiliary channel types are initiated from
7789 * the server end). It's safe to enforce this by assertion
7790 * rather than by ssh_disconnect, because the real point is
7791 * that we never constructed a half-open channel structure in
7792 * the first place with any type other than the above.
7794 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7797 del234(ssh->channels, c);
7801 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7804 int typelen, want_reply;
7805 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7806 struct ssh_channel *c;
7807 struct Packet *pktout;
7809 c = ssh2_channel_msg(ssh, pktin);
7812 if (c->type == CHAN_SHARING) {
7813 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7814 pktin->body, pktin->length);
7817 ssh_pkt_getstring(pktin, &type, &typelen);
7818 want_reply = ssh2_pkt_getbool(pktin);
7820 if (c->closes & CLOSES_SENT_CLOSE) {
7822 * We don't reply to channel requests after we've sent
7823 * CHANNEL_CLOSE for the channel, because our reply might
7824 * cross in the network with the other side's CHANNEL_CLOSE
7825 * and arrive after they have wound the channel up completely.
7831 * Having got the channel number, we now look at
7832 * the request type string to see if it's something
7835 if (c == ssh->mainchan) {
7837 * We recognise "exit-status" and "exit-signal" on
7838 * the primary channel.
7840 if (typelen == 11 &&
7841 !memcmp(type, "exit-status", 11)) {
7843 ssh->exitcode = ssh_pkt_getuint32(pktin);
7844 logeventf(ssh, "Server sent command exit status %d",
7846 reply = SSH2_MSG_CHANNEL_SUCCESS;
7848 } else if (typelen == 11 &&
7849 !memcmp(type, "exit-signal", 11)) {
7851 int is_plausible = TRUE, is_int = FALSE;
7852 char *fmt_sig = "", *fmt_msg = "";
7854 int msglen = 0, core = FALSE;
7855 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7856 * provide an `int' for the signal, despite its
7857 * having been a `string' in the drafts of RFC 4254 since at
7858 * least 2001. (Fixed in session.c 1.147.) Try to
7859 * infer which we can safely parse it as. */
7861 unsigned char *p = pktin->body +
7863 long len = pktin->length - pktin->savedpos;
7864 unsigned long num = GET_32BIT(p); /* what is it? */
7865 /* If it's 0, it hardly matters; assume string */
7869 int maybe_int = FALSE, maybe_str = FALSE;
7870 #define CHECK_HYPOTHESIS(offset, result) \
7873 int q = toint(offset); \
7874 if (q >= 0 && q+4 <= len) { \
7875 q = toint(q + 4 + GET_32BIT(p+q)); \
7876 if (q >= 0 && q+4 <= len && \
7877 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7882 CHECK_HYPOTHESIS(4+1, maybe_int);
7883 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7884 #undef CHECK_HYPOTHESIS
7885 if (maybe_int && !maybe_str)
7887 else if (!maybe_int && maybe_str)
7890 /* Crikey. Either or neither. Panic. */
7891 is_plausible = FALSE;
7894 ssh->exitcode = 128; /* means `unknown signal' */
7897 /* Old non-standard OpenSSH. */
7898 int signum = ssh_pkt_getuint32(pktin);
7899 fmt_sig = dupprintf(" %d", signum);
7900 ssh->exitcode = 128 + signum;
7902 /* As per RFC 4254. */
7905 ssh_pkt_getstring(pktin, &sig, &siglen);
7906 /* Signal name isn't supposed to be blank, but
7907 * let's cope gracefully if it is. */
7909 fmt_sig = dupprintf(" \"%.*s\"",
7914 * Really hideous method of translating the
7915 * signal description back into a locally
7916 * meaningful number.
7921 #define TRANSLATE_SIGNAL(s) \
7922 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7923 ssh->exitcode = 128 + SIG ## s
7925 TRANSLATE_SIGNAL(ABRT);
7928 TRANSLATE_SIGNAL(ALRM);
7931 TRANSLATE_SIGNAL(FPE);
7934 TRANSLATE_SIGNAL(HUP);
7937 TRANSLATE_SIGNAL(ILL);
7940 TRANSLATE_SIGNAL(INT);
7943 TRANSLATE_SIGNAL(KILL);
7946 TRANSLATE_SIGNAL(PIPE);
7949 TRANSLATE_SIGNAL(QUIT);
7952 TRANSLATE_SIGNAL(SEGV);
7955 TRANSLATE_SIGNAL(TERM);
7958 TRANSLATE_SIGNAL(USR1);
7961 TRANSLATE_SIGNAL(USR2);
7963 #undef TRANSLATE_SIGNAL
7965 ssh->exitcode = 128;
7967 core = ssh2_pkt_getbool(pktin);
7968 ssh_pkt_getstring(pktin, &msg, &msglen);
7970 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7972 /* ignore lang tag */
7973 } /* else don't attempt to parse */
7974 logeventf(ssh, "Server exited on signal%s%s%s",
7975 fmt_sig, core ? " (core dumped)" : "",
7977 if (*fmt_sig) sfree(fmt_sig);
7978 if (*fmt_msg) sfree(fmt_msg);
7979 reply = SSH2_MSG_CHANNEL_SUCCESS;
7984 * This is a channel request we don't know
7985 * about, so we now either ignore the request
7986 * or respond with CHANNEL_FAILURE, depending
7989 reply = SSH2_MSG_CHANNEL_FAILURE;
7992 pktout = ssh2_pkt_init(reply);
7993 ssh2_pkt_adduint32(pktout, c->remoteid);
7994 ssh2_pkt_send(ssh, pktout);
7998 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8001 int typelen, want_reply;
8002 struct Packet *pktout;
8004 ssh_pkt_getstring(pktin, &type, &typelen);
8005 want_reply = ssh2_pkt_getbool(pktin);
8008 * We currently don't support any global requests
8009 * at all, so we either ignore the request or
8010 * respond with REQUEST_FAILURE, depending on
8014 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8015 ssh2_pkt_send(ssh, pktout);
8019 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8023 struct X11FakeAuth *auth;
8026 * Make up a new set of fake X11 auth data, and add it to the tree
8027 * of currently valid ones with an indication of the sharing
8028 * context that it's relevant to.
8030 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8031 auth->share_cs = share_cs;
8032 auth->share_chan = share_chan;
8037 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8039 del234(ssh->x11authtree, auth);
8040 x11_free_fake_auth(auth);
8043 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8051 struct ssh_channel *c;
8052 unsigned remid, winsize, pktsize;
8053 unsigned our_winsize_override = 0;
8054 struct Packet *pktout;
8056 ssh_pkt_getstring(pktin, &type, &typelen);
8057 c = snew(struct ssh_channel);
8060 remid = ssh_pkt_getuint32(pktin);
8061 winsize = ssh_pkt_getuint32(pktin);
8062 pktsize = ssh_pkt_getuint32(pktin);
8064 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8067 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8068 addrstr = snewn(peeraddrlen+1, char);
8069 memcpy(addrstr, peeraddr, peeraddrlen);
8070 addrstr[peeraddrlen] = '\0';
8071 peerport = ssh_pkt_getuint32(pktin);
8073 logeventf(ssh, "Received X11 connect request from %s:%d",
8076 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8077 error = "X11 forwarding is not enabled";
8079 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8082 c->u.x11.initial = TRUE;
8085 * If we are a connection-sharing upstream, then we should
8086 * initially present a very small window, adequate to take
8087 * the X11 initial authorisation packet but not much more.
8088 * Downstream will then present us a larger window (by
8089 * fiat of the connection-sharing protocol) and we can
8090 * guarantee to send a positive-valued WINDOW_ADJUST.
8093 our_winsize_override = 128;
8095 logevent("Opened X11 forward channel");
8099 } else if (typelen == 15 &&
8100 !memcmp(type, "forwarded-tcpip", 15)) {
8101 struct ssh_rportfwd pf, *realpf;
8104 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8105 pf.shost = dupprintf("%.*s", shostlen, shost);
8106 pf.sport = ssh_pkt_getuint32(pktin);
8107 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8108 peerport = ssh_pkt_getuint32(pktin);
8109 realpf = find234(ssh->rportfwds, &pf, NULL);
8110 logeventf(ssh, "Received remote port %s:%d open request "
8111 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8114 if (realpf == NULL) {
8115 error = "Remote port is not recognised";
8119 if (realpf->share_ctx) {
8121 * This port forwarding is on behalf of a
8122 * connection-sharing downstream, so abandon our own
8123 * channel-open procedure and just pass the message on
8126 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8127 pktin->body, pktin->length);
8132 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8133 c, ssh->conf, realpf->pfrec->addressfamily);
8134 logeventf(ssh, "Attempting to forward remote port to "
8135 "%s:%d", realpf->dhost, realpf->dport);
8137 logeventf(ssh, "Port open failed: %s", err);
8139 error = "Port open failed";
8141 logevent("Forwarded port opened successfully");
8142 c->type = CHAN_SOCKDATA;
8145 } else if (typelen == 22 &&
8146 !memcmp(type, "auth-agent@openssh.com", 22)) {
8147 if (!ssh->agentfwd_enabled)
8148 error = "Agent forwarding is not enabled";
8150 c->type = CHAN_AGENT; /* identify channel type */
8151 c->u.a.lensofar = 0;
8152 c->u.a.message = NULL;
8153 c->u.a.outstanding_requests = 0;
8156 error = "Unsupported channel type requested";
8159 c->remoteid = remid;
8160 c->halfopen = FALSE;
8162 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8163 ssh2_pkt_adduint32(pktout, c->remoteid);
8164 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8165 ssh2_pkt_addstring(pktout, error);
8166 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8167 ssh2_pkt_send(ssh, pktout);
8168 logeventf(ssh, "Rejected channel open: %s", error);
8171 ssh2_channel_init(c);
8172 c->v.v2.remwindow = winsize;
8173 c->v.v2.remmaxpkt = pktsize;
8174 if (our_winsize_override) {
8175 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8176 our_winsize_override;
8178 add234(ssh->channels, c);
8179 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8180 ssh2_pkt_adduint32(pktout, c->remoteid);
8181 ssh2_pkt_adduint32(pktout, c->localid);
8182 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8183 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8184 ssh2_pkt_send(ssh, pktout);
8188 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8189 void *share_cs, void *share_chan,
8190 const char *peer_addr, int peer_port,
8191 int endian, int protomajor, int protominor,
8192 const void *initial_data, int initial_len)
8195 * This function is called when we've just discovered that an X
8196 * forwarding channel on which we'd been handling the initial auth
8197 * ourselves turns out to be destined for a connection-sharing
8198 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8199 * that we completely stop tracking windows and buffering data and
8200 * just pass more or less unmodified SSH messages back and forth.
8202 c->type = CHAN_SHARING;
8203 c->u.sharing.ctx = share_cs;
8204 share_setup_x11_channel(share_cs, share_chan,
8205 c->localid, c->remoteid, c->v.v2.remwindow,
8206 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8207 peer_addr, peer_port, endian,
8208 protomajor, protominor,
8209 initial_data, initial_len);
8212 void sshfwd_x11_is_local(struct ssh_channel *c)
8215 * This function is called when we've just discovered that an X
8216 * forwarding channel is _not_ destined for a connection-sharing
8217 * downstream but we're going to handle it ourselves. We stop
8218 * presenting a cautiously small window and go into ordinary data
8221 c->u.x11.initial = FALSE;
8222 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8226 * Buffer banner messages for later display at some convenient point,
8227 * if we're going to display them.
8229 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8231 /* Arbitrary limit to prevent unbounded inflation of buffer */
8232 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8233 bufchain_size(&ssh->banner) <= 131072) {
8234 char *banner = NULL;
8236 ssh_pkt_getstring(pktin, &banner, &size);
8238 bufchain_add(&ssh->banner, banner, size);
8242 /* Helper function to deal with sending tty modes for "pty-req" */
8243 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8245 struct Packet *pktout = (struct Packet *)data;
8247 unsigned int arg = 0;
8248 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8249 if (i == lenof(ssh_ttymodes)) return;
8250 switch (ssh_ttymodes[i].type) {
8252 arg = ssh_tty_parse_specchar(val);
8255 arg = ssh_tty_parse_boolean(val);
8258 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8259 ssh2_pkt_adduint32(pktout, arg);
8262 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8265 struct ssh2_setup_x11_state {
8269 struct Packet *pktout;
8270 crStateP(ssh2_setup_x11_state, ctx);
8274 logevent("Requesting X11 forwarding");
8275 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8277 ssh2_pkt_addbool(pktout, 0); /* many connections */
8278 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8279 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8280 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8281 ssh2_pkt_send(ssh, pktout);
8283 /* Wait to be called back with either a response packet, or NULL
8284 * meaning clean up and free our data */
8288 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8289 logevent("X11 forwarding enabled");
8290 ssh->X11_fwd_enabled = TRUE;
8292 logevent("X11 forwarding refused");
8298 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8301 struct ssh2_setup_agent_state {
8305 struct Packet *pktout;
8306 crStateP(ssh2_setup_agent_state, ctx);
8310 logevent("Requesting OpenSSH-style agent forwarding");
8311 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8312 ssh2_setup_agent, s);
8313 ssh2_pkt_send(ssh, pktout);
8315 /* Wait to be called back with either a response packet, or NULL
8316 * meaning clean up and free our data */
8320 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8321 logevent("Agent forwarding enabled");
8322 ssh->agentfwd_enabled = TRUE;
8324 logevent("Agent forwarding refused");
8330 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8333 struct ssh2_setup_pty_state {
8337 struct Packet *pktout;
8338 crStateP(ssh2_setup_pty_state, ctx);
8342 /* Unpick the terminal-speed string. */
8343 /* XXX perhaps we should allow no speeds to be sent. */
8344 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8345 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8346 /* Build the pty request. */
8347 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8349 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8350 ssh2_pkt_adduint32(pktout, ssh->term_width);
8351 ssh2_pkt_adduint32(pktout, ssh->term_height);
8352 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8353 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8354 ssh2_pkt_addstring_start(pktout);
8355 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8356 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8357 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8358 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8359 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8360 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8361 ssh2_pkt_send(ssh, pktout);
8362 ssh->state = SSH_STATE_INTERMED;
8364 /* Wait to be called back with either a response packet, or NULL
8365 * meaning clean up and free our data */
8369 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8370 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8371 ssh->ospeed, ssh->ispeed);
8372 ssh->got_pty = TRUE;
8374 c_write_str(ssh, "Server refused to allocate pty\r\n");
8375 ssh->editing = ssh->echoing = 1;
8382 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8385 struct ssh2_setup_env_state {
8387 int num_env, env_left, env_ok;
8390 struct Packet *pktout;
8391 crStateP(ssh2_setup_env_state, ctx);
8396 * Send environment variables.
8398 * Simplest thing here is to send all the requests at once, and
8399 * then wait for a whole bunch of successes or failures.
8405 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8407 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8408 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8409 ssh2_pkt_addstring(pktout, key);
8410 ssh2_pkt_addstring(pktout, val);
8411 ssh2_pkt_send(ssh, pktout);
8416 logeventf(ssh, "Sent %d environment variables", s->num_env);
8421 s->env_left = s->num_env;
8423 while (s->env_left > 0) {
8424 /* Wait to be called back with either a response packet,
8425 * or NULL meaning clean up and free our data */
8427 if (!pktin) goto out;
8428 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8433 if (s->env_ok == s->num_env) {
8434 logevent("All environment variables successfully set");
8435 } else if (s->env_ok == 0) {
8436 logevent("All environment variables refused");
8437 c_write_str(ssh, "Server refused to set environment variables\r\n");
8439 logeventf(ssh, "%d environment variables refused",
8440 s->num_env - s->env_ok);
8441 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8449 * Handle the SSH-2 userauth and connection layers.
8451 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8453 do_ssh2_authconn(ssh, NULL, 0, pktin);
8456 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8460 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8463 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8464 struct Packet *pktin)
8466 struct do_ssh2_authconn_state {
8470 AUTH_TYPE_PUBLICKEY,
8471 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8472 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8474 AUTH_TYPE_GSSAPI, /* always QUIET */
8475 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8476 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8478 int done_service_req;
8479 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8480 int tried_pubkey_config, done_agent;
8485 int kbd_inter_refused;
8486 int we_are_in, userauth_success;
8487 prompts_t *cur_prompt;
8492 void *publickey_blob;
8493 int publickey_bloblen;
8494 int publickey_encrypted;
8495 char *publickey_algorithm;
8496 char *publickey_comment;
8497 unsigned char agent_request[5], *agent_response, *agentp;
8498 int agent_responselen;
8499 unsigned char *pkblob_in_agent;
8501 char *pkblob, *alg, *commentp;
8502 int pklen, alglen, commentlen;
8503 int siglen, retlen, len;
8504 char *q, *agentreq, *ret;
8506 struct Packet *pktout;
8509 struct ssh_gss_library *gsslib;
8510 Ssh_gss_ctx gss_ctx;
8511 Ssh_gss_buf gss_buf;
8512 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8513 Ssh_gss_name gss_srv_name;
8514 Ssh_gss_stat gss_stat;
8517 crState(do_ssh2_authconn_state);
8521 /* Register as a handler for all the messages this coroutine handles. */
8522 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8523 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8524 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8525 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8526 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8527 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8528 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8529 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8530 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8531 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8532 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8533 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8534 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8535 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8536 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8537 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8538 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8539 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8543 s->done_service_req = FALSE;
8544 s->we_are_in = s->userauth_success = FALSE;
8545 s->agent_response = NULL;
8547 s->tried_gssapi = FALSE;
8550 if (!ssh->bare_connection) {
8551 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8553 * Request userauth protocol, and await a response to it.
8555 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8556 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8557 ssh2_pkt_send(ssh, s->pktout);
8558 crWaitUntilV(pktin);
8559 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8560 s->done_service_req = TRUE;
8562 if (!s->done_service_req) {
8564 * Request connection protocol directly, without authentication.
8566 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8567 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8568 ssh2_pkt_send(ssh, s->pktout);
8569 crWaitUntilV(pktin);
8570 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8571 s->we_are_in = TRUE; /* no auth required */
8573 bombout(("Server refused service request"));
8578 s->we_are_in = TRUE;
8581 /* Arrange to be able to deal with any BANNERs that come in.
8582 * (We do this now as packets may come in during the next bit.) */
8583 bufchain_init(&ssh->banner);
8584 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8585 ssh2_msg_userauth_banner;
8588 * Misc one-time setup for authentication.
8590 s->publickey_blob = NULL;
8591 if (!s->we_are_in) {
8594 * Load the public half of any configured public key file
8597 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8598 if (!filename_is_null(s->keyfile)) {
8600 logeventf(ssh, "Reading private key file \"%.150s\"",
8601 filename_to_str(s->keyfile));
8602 keytype = key_type(s->keyfile);
8603 if (keytype == SSH_KEYTYPE_SSH2) {
8606 ssh2_userkey_loadpub(s->keyfile,
8607 &s->publickey_algorithm,
8608 &s->publickey_bloblen,
8609 &s->publickey_comment, &error);
8610 if (s->publickey_blob) {
8611 s->publickey_encrypted =
8612 ssh2_userkey_encrypted(s->keyfile, NULL);
8615 logeventf(ssh, "Unable to load private key (%s)",
8617 msgbuf = dupprintf("Unable to load private key file "
8618 "\"%.150s\" (%s)\r\n",
8619 filename_to_str(s->keyfile),
8621 c_write_str(ssh, msgbuf);
8626 logeventf(ssh, "Unable to use this key file (%s)",
8627 key_type_to_str(keytype));
8628 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8630 filename_to_str(s->keyfile),
8631 key_type_to_str(keytype));
8632 c_write_str(ssh, msgbuf);
8634 s->publickey_blob = NULL;
8639 * Find out about any keys Pageant has (but if there's a
8640 * public key configured, filter out all others).
8643 s->agent_response = NULL;
8644 s->pkblob_in_agent = NULL;
8645 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8649 logevent("Pageant is running. Requesting keys.");
8651 /* Request the keys held by the agent. */
8652 PUT_32BIT(s->agent_request, 1);
8653 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8654 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8655 ssh_agent_callback, ssh)) {
8659 bombout(("Unexpected data from server while"
8660 " waiting for agent response"));
8663 } while (pktin || inlen > 0);
8664 r = ssh->agent_response;
8665 s->agent_responselen = ssh->agent_response_len;
8667 s->agent_response = (unsigned char *) r;
8668 if (s->agent_response && s->agent_responselen >= 5 &&
8669 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8672 p = s->agent_response + 5;
8673 s->nkeys = toint(GET_32BIT(p));
8676 * Vet the Pageant response to ensure that the key
8677 * count and blob lengths make sense.
8680 logeventf(ssh, "Pageant response contained a negative"
8681 " key count %d", s->nkeys);
8683 goto done_agent_query;
8685 unsigned char *q = p + 4;
8686 int lenleft = s->agent_responselen - 5 - 4;
8688 for (keyi = 0; keyi < s->nkeys; keyi++) {
8689 int bloblen, commentlen;
8691 logeventf(ssh, "Pageant response was truncated");
8693 goto done_agent_query;
8695 bloblen = toint(GET_32BIT(q));
8696 if (bloblen < 0 || bloblen > lenleft) {
8697 logeventf(ssh, "Pageant response was truncated");
8699 goto done_agent_query;
8701 lenleft -= 4 + bloblen;
8703 commentlen = toint(GET_32BIT(q));
8704 if (commentlen < 0 || commentlen > lenleft) {
8705 logeventf(ssh, "Pageant response was truncated");
8707 goto done_agent_query;
8709 lenleft -= 4 + commentlen;
8710 q += 4 + commentlen;
8715 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8716 if (s->publickey_blob) {
8717 /* See if configured key is in agent. */
8718 for (keyi = 0; keyi < s->nkeys; keyi++) {
8719 s->pklen = toint(GET_32BIT(p));
8720 if (s->pklen == s->publickey_bloblen &&
8721 !memcmp(p+4, s->publickey_blob,
8722 s->publickey_bloblen)) {
8723 logeventf(ssh, "Pageant key #%d matches "
8724 "configured key file", keyi);
8726 s->pkblob_in_agent = p;
8730 p += toint(GET_32BIT(p)) + 4; /* comment */
8732 if (!s->pkblob_in_agent) {
8733 logevent("Configured key file not in Pageant");
8738 logevent("Failed to get reply from Pageant");
8746 * We repeat this whole loop, including the username prompt,
8747 * until we manage a successful authentication. If the user
8748 * types the wrong _password_, they can be sent back to the
8749 * beginning to try another username, if this is configured on.
8750 * (If they specify a username in the config, they are never
8751 * asked, even if they do give a wrong password.)
8753 * I think this best serves the needs of
8755 * - the people who have no configuration, no keys, and just
8756 * want to try repeated (username,password) pairs until they
8757 * type both correctly
8759 * - people who have keys and configuration but occasionally
8760 * need to fall back to passwords
8762 * - people with a key held in Pageant, who might not have
8763 * logged in to a particular machine before; so they want to
8764 * type a username, and then _either_ their key will be
8765 * accepted, _or_ they will type a password. If they mistype
8766 * the username they will want to be able to get back and
8769 s->got_username = FALSE;
8770 while (!s->we_are_in) {
8774 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8776 * We got a username last time round this loop, and
8777 * with change_username turned off we don't try to get
8780 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8781 int ret; /* need not be kept over crReturn */
8782 s->cur_prompt = new_prompts(ssh->frontend);
8783 s->cur_prompt->to_server = TRUE;
8784 s->cur_prompt->name = dupstr("SSH login name");
8785 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8786 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8789 crWaitUntilV(!pktin);
8790 ret = get_userpass_input(s->cur_prompt, in, inlen);
8795 * get_userpass_input() failed to get a username.
8798 free_prompts(s->cur_prompt);
8799 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8802 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8803 free_prompts(s->cur_prompt);
8806 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8807 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8808 c_write_str(ssh, stuff);
8812 s->got_username = TRUE;
8815 * Send an authentication request using method "none": (a)
8816 * just in case it succeeds, and (b) so that we know what
8817 * authentication methods we can usefully try next.
8819 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8821 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8822 ssh2_pkt_addstring(s->pktout, ssh->username);
8823 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8824 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8825 ssh2_pkt_send(ssh, s->pktout);
8826 s->type = AUTH_TYPE_NONE;
8828 s->we_are_in = FALSE;
8830 s->tried_pubkey_config = FALSE;
8831 s->kbd_inter_refused = FALSE;
8833 /* Reset agent request state. */
8834 s->done_agent = FALSE;
8835 if (s->agent_response) {
8836 if (s->pkblob_in_agent) {
8837 s->agentp = s->pkblob_in_agent;
8839 s->agentp = s->agent_response + 5 + 4;
8845 char *methods = NULL;
8849 * Wait for the result of the last authentication request.
8852 crWaitUntilV(pktin);
8854 * Now is a convenient point to spew any banner material
8855 * that we've accumulated. (This should ensure that when
8856 * we exit the auth loop, we haven't any left to deal
8860 int size = bufchain_size(&ssh->banner);
8862 * Don't show the banner if we're operating in
8863 * non-verbose non-interactive mode. (It's probably
8864 * a script, which means nobody will read the
8865 * banner _anyway_, and moreover the printing of
8866 * the banner will screw up processing on the
8867 * output of (say) plink.)
8869 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8870 char *banner = snewn(size, char);
8871 bufchain_fetch(&ssh->banner, banner, size);
8872 c_write_untrusted(ssh, banner, size);
8875 bufchain_clear(&ssh->banner);
8877 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8878 logevent("Access granted");
8879 s->we_are_in = s->userauth_success = TRUE;
8883 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8884 bombout(("Strange packet received during authentication: "
8885 "type %d", pktin->type));
8892 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8893 * we can look at the string in it and know what we can
8894 * helpfully try next.
8896 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8897 ssh_pkt_getstring(pktin, &methods, &methlen);
8898 if (!ssh2_pkt_getbool(pktin)) {
8900 * We have received an unequivocal Access
8901 * Denied. This can translate to a variety of
8902 * messages, or no message at all.
8904 * For forms of authentication which are attempted
8905 * implicitly, by which I mean without printing
8906 * anything in the window indicating that we're
8907 * trying them, we should never print 'Access
8910 * If we do print a message saying that we're
8911 * attempting some kind of authentication, it's OK
8912 * to print a followup message saying it failed -
8913 * but the message may sometimes be more specific
8914 * than simply 'Access denied'.
8916 * Additionally, if we'd just tried password
8917 * authentication, we should break out of this
8918 * whole loop so as to go back to the username
8919 * prompt (iff we're configured to allow
8920 * username change attempts).
8922 if (s->type == AUTH_TYPE_NONE) {
8924 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8925 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8926 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8927 c_write_str(ssh, "Server refused our key\r\n");
8928 logevent("Server refused our key");
8929 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8930 /* This _shouldn't_ happen except by a
8931 * protocol bug causing client and server to
8932 * disagree on what is a correct signature. */
8933 c_write_str(ssh, "Server refused public-key signature"
8934 " despite accepting key!\r\n");
8935 logevent("Server refused public-key signature"
8936 " despite accepting key!");
8937 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8938 /* quiet, so no c_write */
8939 logevent("Server refused keyboard-interactive authentication");
8940 } else if (s->type==AUTH_TYPE_GSSAPI) {
8941 /* always quiet, so no c_write */
8942 /* also, the code down in the GSSAPI block has
8943 * already logged this in the Event Log */
8944 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8945 logevent("Keyboard-interactive authentication failed");
8946 c_write_str(ssh, "Access denied\r\n");
8948 assert(s->type == AUTH_TYPE_PASSWORD);
8949 logevent("Password authentication failed");
8950 c_write_str(ssh, "Access denied\r\n");
8952 if (conf_get_int(ssh->conf, CONF_change_username)) {
8953 /* XXX perhaps we should allow
8954 * keyboard-interactive to do this too? */
8955 s->we_are_in = FALSE;
8960 c_write_str(ssh, "Further authentication required\r\n");
8961 logevent("Further authentication required");
8965 in_commasep_string("publickey", methods, methlen);
8967 in_commasep_string("password", methods, methlen);
8968 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8969 in_commasep_string("keyboard-interactive", methods, methlen);
8972 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8973 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8974 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8975 ssh->gsslibs->nlibraries > 0;
8979 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8981 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8984 * Attempt public-key authentication using a key from Pageant.
8987 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8989 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8991 /* Unpack key from agent response */
8992 s->pklen = toint(GET_32BIT(s->agentp));
8994 s->pkblob = (char *)s->agentp;
8995 s->agentp += s->pklen;
8996 s->alglen = toint(GET_32BIT(s->pkblob));
8997 s->alg = s->pkblob + 4;
8998 s->commentlen = toint(GET_32BIT(s->agentp));
9000 s->commentp = (char *)s->agentp;
9001 s->agentp += s->commentlen;
9002 /* s->agentp now points at next key, if any */
9004 /* See if server will accept it */
9005 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9006 ssh2_pkt_addstring(s->pktout, ssh->username);
9007 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9008 /* service requested */
9009 ssh2_pkt_addstring(s->pktout, "publickey");
9011 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9012 ssh2_pkt_addstring_start(s->pktout);
9013 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9014 ssh2_pkt_addstring_start(s->pktout);
9015 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9016 ssh2_pkt_send(ssh, s->pktout);
9017 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9019 crWaitUntilV(pktin);
9020 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9022 /* Offer of key refused. */
9029 if (flags & FLAG_VERBOSE) {
9030 c_write_str(ssh, "Authenticating with "
9032 c_write(ssh, s->commentp, s->commentlen);
9033 c_write_str(ssh, "\" from agent\r\n");
9037 * Server is willing to accept the key.
9038 * Construct a SIGN_REQUEST.
9040 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9041 ssh2_pkt_addstring(s->pktout, ssh->username);
9042 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9043 /* service requested */
9044 ssh2_pkt_addstring(s->pktout, "publickey");
9046 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9047 ssh2_pkt_addstring_start(s->pktout);
9048 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9049 ssh2_pkt_addstring_start(s->pktout);
9050 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9052 /* Ask agent for signature. */
9053 s->siglen = s->pktout->length - 5 + 4 +
9054 ssh->v2_session_id_len;
9055 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9057 s->len = 1; /* message type */
9058 s->len += 4 + s->pklen; /* key blob */
9059 s->len += 4 + s->siglen; /* data to sign */
9060 s->len += 4; /* flags */
9061 s->agentreq = snewn(4 + s->len, char);
9062 PUT_32BIT(s->agentreq, s->len);
9063 s->q = s->agentreq + 4;
9064 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9065 PUT_32BIT(s->q, s->pklen);
9067 memcpy(s->q, s->pkblob, s->pklen);
9069 PUT_32BIT(s->q, s->siglen);
9071 /* Now the data to be signed... */
9072 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9073 PUT_32BIT(s->q, ssh->v2_session_id_len);
9076 memcpy(s->q, ssh->v2_session_id,
9077 ssh->v2_session_id_len);
9078 s->q += ssh->v2_session_id_len;
9079 memcpy(s->q, s->pktout->data + 5,
9080 s->pktout->length - 5);
9081 s->q += s->pktout->length - 5;
9082 /* And finally the (zero) flags word. */
9084 if (!agent_query(s->agentreq, s->len + 4,
9086 ssh_agent_callback, ssh)) {
9090 bombout(("Unexpected data from server"
9091 " while waiting for agent"
9095 } while (pktin || inlen > 0);
9096 vret = ssh->agent_response;
9097 s->retlen = ssh->agent_response_len;
9102 if (s->retlen >= 9 &&
9103 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9104 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9105 logevent("Sending Pageant's response");
9106 ssh2_add_sigblob(ssh, s->pktout,
9107 s->pkblob, s->pklen,
9109 GET_32BIT(s->ret + 5));
9110 ssh2_pkt_send(ssh, s->pktout);
9111 s->type = AUTH_TYPE_PUBLICKEY;
9113 /* FIXME: less drastic response */
9114 bombout(("Pageant failed to answer challenge"));
9120 /* Do we have any keys left to try? */
9121 if (s->pkblob_in_agent) {
9122 s->done_agent = TRUE;
9123 s->tried_pubkey_config = TRUE;
9126 if (s->keyi >= s->nkeys)
9127 s->done_agent = TRUE;
9130 } else if (s->can_pubkey && s->publickey_blob &&
9131 !s->tried_pubkey_config) {
9133 struct ssh2_userkey *key; /* not live over crReturn */
9134 char *passphrase; /* not live over crReturn */
9136 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9138 s->tried_pubkey_config = TRUE;
9141 * Try the public key supplied in the configuration.
9143 * First, offer the public blob to see if the server is
9144 * willing to accept it.
9146 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9147 ssh2_pkt_addstring(s->pktout, ssh->username);
9148 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9149 /* service requested */
9150 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9151 ssh2_pkt_addbool(s->pktout, FALSE);
9152 /* no signature included */
9153 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9154 ssh2_pkt_addstring_start(s->pktout);
9155 ssh2_pkt_addstring_data(s->pktout,
9156 (char *)s->publickey_blob,
9157 s->publickey_bloblen);
9158 ssh2_pkt_send(ssh, s->pktout);
9159 logevent("Offered public key");
9161 crWaitUntilV(pktin);
9162 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9163 /* Key refused. Give up. */
9164 s->gotit = TRUE; /* reconsider message next loop */
9165 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9166 continue; /* process this new message */
9168 logevent("Offer of public key accepted");
9171 * Actually attempt a serious authentication using
9174 if (flags & FLAG_VERBOSE) {
9175 c_write_str(ssh, "Authenticating with public key \"");
9176 c_write_str(ssh, s->publickey_comment);
9177 c_write_str(ssh, "\"\r\n");
9181 const char *error; /* not live over crReturn */
9182 if (s->publickey_encrypted) {
9184 * Get a passphrase from the user.
9186 int ret; /* need not be kept over crReturn */
9187 s->cur_prompt = new_prompts(ssh->frontend);
9188 s->cur_prompt->to_server = FALSE;
9189 s->cur_prompt->name = dupstr("SSH key passphrase");
9190 add_prompt(s->cur_prompt,
9191 dupprintf("Passphrase for key \"%.100s\": ",
9192 s->publickey_comment),
9194 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9197 crWaitUntilV(!pktin);
9198 ret = get_userpass_input(s->cur_prompt,
9203 /* Failed to get a passphrase. Terminate. */
9204 free_prompts(s->cur_prompt);
9205 ssh_disconnect(ssh, NULL,
9206 "Unable to authenticate",
9207 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9212 dupstr(s->cur_prompt->prompts[0]->result);
9213 free_prompts(s->cur_prompt);
9215 passphrase = NULL; /* no passphrase needed */
9219 * Try decrypting the key.
9221 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9222 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9224 /* burn the evidence */
9225 smemclr(passphrase, strlen(passphrase));
9228 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9230 (key == SSH2_WRONG_PASSPHRASE)) {
9231 c_write_str(ssh, "Wrong passphrase\r\n");
9233 /* and loop again */
9235 c_write_str(ssh, "Unable to load private key (");
9236 c_write_str(ssh, error);
9237 c_write_str(ssh, ")\r\n");
9239 break; /* try something else */
9245 unsigned char *pkblob, *sigblob, *sigdata;
9246 int pkblob_len, sigblob_len, sigdata_len;
9250 * We have loaded the private key and the server
9251 * has announced that it's willing to accept it.
9252 * Hallelujah. Generate a signature and send it.
9254 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9255 ssh2_pkt_addstring(s->pktout, ssh->username);
9256 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9257 /* service requested */
9258 ssh2_pkt_addstring(s->pktout, "publickey");
9260 ssh2_pkt_addbool(s->pktout, TRUE);
9261 /* signature follows */
9262 ssh2_pkt_addstring(s->pktout, key->alg->name);
9263 pkblob = key->alg->public_blob(key->data,
9265 ssh2_pkt_addstring_start(s->pktout);
9266 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9270 * The data to be signed is:
9274 * followed by everything so far placed in the
9277 sigdata_len = s->pktout->length - 5 + 4 +
9278 ssh->v2_session_id_len;
9279 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9281 sigdata = snewn(sigdata_len, unsigned char);
9283 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9284 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9287 memcpy(sigdata+p, ssh->v2_session_id,
9288 ssh->v2_session_id_len);
9289 p += ssh->v2_session_id_len;
9290 memcpy(sigdata+p, s->pktout->data + 5,
9291 s->pktout->length - 5);
9292 p += s->pktout->length - 5;
9293 assert(p == sigdata_len);
9294 sigblob = key->alg->sign(key->data, (char *)sigdata,
9295 sigdata_len, &sigblob_len);
9296 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9297 sigblob, sigblob_len);
9302 ssh2_pkt_send(ssh, s->pktout);
9303 logevent("Sent public key signature");
9304 s->type = AUTH_TYPE_PUBLICKEY;
9305 key->alg->freekey(key->data);
9309 } else if (s->can_gssapi && !s->tried_gssapi) {
9311 /* GSSAPI Authentication */
9316 s->type = AUTH_TYPE_GSSAPI;
9317 s->tried_gssapi = TRUE;
9319 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9322 * Pick the highest GSS library on the preference
9328 for (i = 0; i < ngsslibs; i++) {
9329 int want_id = conf_get_int_int(ssh->conf,
9330 CONF_ssh_gsslist, i);
9331 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9332 if (ssh->gsslibs->libraries[j].id == want_id) {
9333 s->gsslib = &ssh->gsslibs->libraries[j];
9334 goto got_gsslib; /* double break */
9339 * We always expect to have found something in
9340 * the above loop: we only came here if there
9341 * was at least one viable GSS library, and the
9342 * preference list should always mention
9343 * everything and only change the order.
9348 if (s->gsslib->gsslogmsg)
9349 logevent(s->gsslib->gsslogmsg);
9351 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9352 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9353 ssh2_pkt_addstring(s->pktout, ssh->username);
9354 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9355 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9356 logevent("Attempting GSSAPI authentication");
9358 /* add mechanism info */
9359 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9361 /* number of GSSAPI mechanisms */
9362 ssh2_pkt_adduint32(s->pktout,1);
9364 /* length of OID + 2 */
9365 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9366 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9369 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9371 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9373 ssh2_pkt_send(ssh, s->pktout);
9374 crWaitUntilV(pktin);
9375 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9376 logevent("GSSAPI authentication request refused");
9380 /* check returned packet ... */
9382 ssh_pkt_getstring(pktin, &data, &len);
9383 s->gss_rcvtok.value = data;
9384 s->gss_rcvtok.length = len;
9385 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9386 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9387 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9388 memcmp((char *)s->gss_rcvtok.value + 2,
9389 s->gss_buf.value,s->gss_buf.length) ) {
9390 logevent("GSSAPI authentication - wrong response from server");
9394 /* now start running */
9395 s->gss_stat = s->gsslib->import_name(s->gsslib,
9398 if (s->gss_stat != SSH_GSS_OK) {
9399 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9400 logevent("GSSAPI import name failed - Bad service name");
9402 logevent("GSSAPI import name failed");
9406 /* fetch TGT into GSS engine */
9407 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9409 if (s->gss_stat != SSH_GSS_OK) {
9410 logevent("GSSAPI authentication failed to get credentials");
9411 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9415 /* initial tokens are empty */
9416 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9417 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9419 /* now enter the loop */
9421 s->gss_stat = s->gsslib->init_sec_context
9425 conf_get_int(ssh->conf, CONF_gssapifwd),
9429 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9430 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9431 logevent("GSSAPI authentication initialisation failed");
9433 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9434 &s->gss_buf) == SSH_GSS_OK) {
9435 logevent(s->gss_buf.value);
9436 sfree(s->gss_buf.value);
9441 logevent("GSSAPI authentication initialised");
9443 /* Client and server now exchange tokens until GSSAPI
9444 * no longer says CONTINUE_NEEDED */
9446 if (s->gss_sndtok.length != 0) {
9447 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9448 ssh_pkt_addstring_start(s->pktout);
9449 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9450 ssh2_pkt_send(ssh, s->pktout);
9451 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9454 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9455 crWaitUntilV(pktin);
9456 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9457 logevent("GSSAPI authentication - bad server response");
9458 s->gss_stat = SSH_GSS_FAILURE;
9461 ssh_pkt_getstring(pktin, &data, &len);
9462 s->gss_rcvtok.value = data;
9463 s->gss_rcvtok.length = len;
9465 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9467 if (s->gss_stat != SSH_GSS_OK) {
9468 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9469 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9472 logevent("GSSAPI authentication loop finished OK");
9474 /* Now send the MIC */
9476 s->pktout = ssh2_pkt_init(0);
9477 micoffset = s->pktout->length;
9478 ssh_pkt_addstring_start(s->pktout);
9479 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9480 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9481 ssh_pkt_addstring(s->pktout, ssh->username);
9482 ssh_pkt_addstring(s->pktout, "ssh-connection");
9483 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9485 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9486 s->gss_buf.length = s->pktout->length - micoffset;
9488 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9489 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9490 ssh_pkt_addstring_start(s->pktout);
9491 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9492 ssh2_pkt_send(ssh, s->pktout);
9493 s->gsslib->free_mic(s->gsslib, &mic);
9497 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9498 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9501 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9504 * Keyboard-interactive authentication.
9507 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9509 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9511 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9512 ssh2_pkt_addstring(s->pktout, ssh->username);
9513 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9514 /* service requested */
9515 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9517 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9518 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9519 ssh2_pkt_send(ssh, s->pktout);
9521 logevent("Attempting keyboard-interactive authentication");
9523 crWaitUntilV(pktin);
9524 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9525 /* Server is not willing to do keyboard-interactive
9526 * at all (or, bizarrely but legally, accepts the
9527 * user without actually issuing any prompts).
9528 * Give up on it entirely. */
9530 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9531 s->kbd_inter_refused = TRUE; /* don't try it again */
9536 * Loop while the server continues to send INFO_REQUESTs.
9538 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9540 char *name, *inst, *lang;
9541 int name_len, inst_len, lang_len;
9545 * We've got a fresh USERAUTH_INFO_REQUEST.
9546 * Get the preamble and start building a prompt.
9548 ssh_pkt_getstring(pktin, &name, &name_len);
9549 ssh_pkt_getstring(pktin, &inst, &inst_len);
9550 ssh_pkt_getstring(pktin, &lang, &lang_len);
9551 s->cur_prompt = new_prompts(ssh->frontend);
9552 s->cur_prompt->to_server = TRUE;
9555 * Get any prompt(s) from the packet.
9557 s->num_prompts = ssh_pkt_getuint32(pktin);
9558 for (i = 0; i < s->num_prompts; i++) {
9562 static char noprompt[] =
9563 "<server failed to send prompt>: ";
9565 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9566 echo = ssh2_pkt_getbool(pktin);
9569 prompt_len = lenof(noprompt)-1;
9571 add_prompt(s->cur_prompt,
9572 dupprintf("%.*s", prompt_len, prompt),
9577 /* FIXME: better prefix to distinguish from
9579 s->cur_prompt->name =
9580 dupprintf("SSH server: %.*s", name_len, name);
9581 s->cur_prompt->name_reqd = TRUE;
9583 s->cur_prompt->name =
9584 dupstr("SSH server authentication");
9585 s->cur_prompt->name_reqd = FALSE;
9587 /* We add a prefix to try to make it clear that a prompt
9588 * has come from the server.
9589 * FIXME: ugly to print "Using..." in prompt _every_
9590 * time round. Can this be done more subtly? */
9591 /* Special case: for reasons best known to themselves,
9592 * some servers send k-i requests with no prompts and
9593 * nothing to display. Keep quiet in this case. */
9594 if (s->num_prompts || name_len || inst_len) {
9595 s->cur_prompt->instruction =
9596 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9597 inst_len ? "\n" : "", inst_len, inst);
9598 s->cur_prompt->instr_reqd = TRUE;
9600 s->cur_prompt->instr_reqd = FALSE;
9604 * Display any instructions, and get the user's
9608 int ret; /* not live over crReturn */
9609 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9612 crWaitUntilV(!pktin);
9613 ret = get_userpass_input(s->cur_prompt, in, inlen);
9618 * Failed to get responses. Terminate.
9620 free_prompts(s->cur_prompt);
9621 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9622 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9629 * Send the response(s) to the server.
9631 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9632 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9633 for (i=0; i < s->num_prompts; i++) {
9634 ssh2_pkt_addstring(s->pktout,
9635 s->cur_prompt->prompts[i]->result);
9637 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9640 * Free the prompts structure from this iteration.
9641 * If there's another, a new one will be allocated
9642 * when we return to the top of this while loop.
9644 free_prompts(s->cur_prompt);
9647 * Get the next packet in case it's another
9650 crWaitUntilV(pktin);
9655 * We should have SUCCESS or FAILURE now.
9659 } else if (s->can_passwd) {
9662 * Plain old password authentication.
9664 int ret; /* not live over crReturn */
9665 int changereq_first_time; /* not live over crReturn */
9667 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9669 s->cur_prompt = new_prompts(ssh->frontend);
9670 s->cur_prompt->to_server = TRUE;
9671 s->cur_prompt->name = dupstr("SSH password");
9672 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9677 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9680 crWaitUntilV(!pktin);
9681 ret = get_userpass_input(s->cur_prompt, in, inlen);
9686 * Failed to get responses. Terminate.
9688 free_prompts(s->cur_prompt);
9689 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9690 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9695 * Squirrel away the password. (We may need it later if
9696 * asked to change it.)
9698 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9699 free_prompts(s->cur_prompt);
9702 * Send the password packet.
9704 * We pad out the password packet to 256 bytes to make
9705 * it harder for an attacker to find the length of the
9708 * Anyone using a password longer than 256 bytes
9709 * probably doesn't have much to worry about from
9710 * people who find out how long their password is!
9712 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9713 ssh2_pkt_addstring(s->pktout, ssh->username);
9714 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9715 /* service requested */
9716 ssh2_pkt_addstring(s->pktout, "password");
9717 ssh2_pkt_addbool(s->pktout, FALSE);
9718 ssh2_pkt_addstring(s->pktout, s->password);
9719 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9720 logevent("Sent password");
9721 s->type = AUTH_TYPE_PASSWORD;
9724 * Wait for next packet, in case it's a password change
9727 crWaitUntilV(pktin);
9728 changereq_first_time = TRUE;
9730 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9733 * We're being asked for a new password
9734 * (perhaps not for the first time).
9735 * Loop until the server accepts it.
9738 int got_new = FALSE; /* not live over crReturn */
9739 char *prompt; /* not live over crReturn */
9740 int prompt_len; /* not live over crReturn */
9744 if (changereq_first_time)
9745 msg = "Server requested password change";
9747 msg = "Server rejected new password";
9749 c_write_str(ssh, msg);
9750 c_write_str(ssh, "\r\n");
9753 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9755 s->cur_prompt = new_prompts(ssh->frontend);
9756 s->cur_prompt->to_server = TRUE;
9757 s->cur_prompt->name = dupstr("New SSH password");
9758 s->cur_prompt->instruction =
9759 dupprintf("%.*s", prompt_len, prompt);
9760 s->cur_prompt->instr_reqd = TRUE;
9762 * There's no explicit requirement in the protocol
9763 * for the "old" passwords in the original and
9764 * password-change messages to be the same, and
9765 * apparently some Cisco kit supports password change
9766 * by the user entering a blank password originally
9767 * and the real password subsequently, so,
9768 * reluctantly, we prompt for the old password again.
9770 * (On the other hand, some servers don't even bother
9771 * to check this field.)
9773 add_prompt(s->cur_prompt,
9774 dupstr("Current password (blank for previously entered password): "),
9776 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9778 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9782 * Loop until the user manages to enter the same
9787 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9790 crWaitUntilV(!pktin);
9791 ret = get_userpass_input(s->cur_prompt, in, inlen);
9796 * Failed to get responses. Terminate.
9798 /* burn the evidence */
9799 free_prompts(s->cur_prompt);
9800 smemclr(s->password, strlen(s->password));
9802 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9803 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9809 * If the user specified a new original password
9810 * (IYSWIM), overwrite any previously specified
9812 * (A side effect is that the user doesn't have to
9813 * re-enter it if they louse up the new password.)
9815 if (s->cur_prompt->prompts[0]->result[0]) {
9816 smemclr(s->password, strlen(s->password));
9817 /* burn the evidence */
9820 dupstr(s->cur_prompt->prompts[0]->result);
9824 * Check the two new passwords match.
9826 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9827 s->cur_prompt->prompts[2]->result)
9830 /* They don't. Silly user. */
9831 c_write_str(ssh, "Passwords do not match\r\n");
9836 * Send the new password (along with the old one).
9837 * (see above for padding rationale)
9839 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9840 ssh2_pkt_addstring(s->pktout, ssh->username);
9841 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9842 /* service requested */
9843 ssh2_pkt_addstring(s->pktout, "password");
9844 ssh2_pkt_addbool(s->pktout, TRUE);
9845 ssh2_pkt_addstring(s->pktout, s->password);
9846 ssh2_pkt_addstring(s->pktout,
9847 s->cur_prompt->prompts[1]->result);
9848 free_prompts(s->cur_prompt);
9849 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9850 logevent("Sent new password");
9853 * Now see what the server has to say about it.
9854 * (If it's CHANGEREQ again, it's not happy with the
9857 crWaitUntilV(pktin);
9858 changereq_first_time = FALSE;
9863 * We need to reexamine the current pktin at the top
9864 * of the loop. Either:
9865 * - we weren't asked to change password at all, in
9866 * which case it's a SUCCESS or FAILURE with the
9868 * - we sent a new password, and the server was
9869 * either OK with it (SUCCESS or FAILURE w/partial
9870 * success) or unhappy with the _old_ password
9871 * (FAILURE w/o partial success)
9872 * In any of these cases, we go back to the top of
9873 * the loop and start again.
9878 * We don't need the old password any more, in any
9879 * case. Burn the evidence.
9881 smemclr(s->password, strlen(s->password));
9885 char *str = dupprintf("No supported authentication methods available"
9886 " (server sent: %.*s)",
9889 ssh_disconnect(ssh, str,
9890 "No supported authentication methods available",
9891 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9901 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9903 /* Clear up various bits and pieces from authentication. */
9904 if (s->publickey_blob) {
9905 sfree(s->publickey_blob);
9906 sfree(s->publickey_comment);
9908 if (s->agent_response)
9909 sfree(s->agent_response);
9911 if (s->userauth_success && !ssh->bare_connection) {
9913 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9914 * packets since. Signal the transport layer to consider enacting
9915 * delayed compression.
9917 * (Relying on we_are_in is not sufficient, as
9918 * draft-miller-secsh-compression-delayed is quite clear that it
9919 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9920 * become set for other reasons.)
9922 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9925 ssh->channels = newtree234(ssh_channelcmp);
9928 * Set up handlers for some connection protocol messages, so we
9929 * don't have to handle them repeatedly in this coroutine.
9931 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9932 ssh2_msg_channel_window_adjust;
9933 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9934 ssh2_msg_global_request;
9937 * Create the main session channel.
9939 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9940 ssh->mainchan = NULL;
9942 ssh->mainchan = snew(struct ssh_channel);
9943 ssh->mainchan->ssh = ssh;
9944 ssh2_channel_init(ssh->mainchan);
9946 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9948 * Just start a direct-tcpip channel and use it as the main
9951 ssh_send_port_open(ssh->mainchan,
9952 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9953 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9957 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9958 logevent("Opening session as main channel");
9959 ssh2_pkt_send(ssh, s->pktout);
9960 ssh->ncmode = FALSE;
9962 crWaitUntilV(pktin);
9963 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9964 bombout(("Server refused to open channel"));
9966 /* FIXME: error data comes back in FAILURE packet */
9968 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9969 bombout(("Server's channel confirmation cited wrong channel"));
9972 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9973 ssh->mainchan->halfopen = FALSE;
9974 ssh->mainchan->type = CHAN_MAINSESSION;
9975 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9976 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9977 add234(ssh->channels, ssh->mainchan);
9978 update_specials_menu(ssh->frontend);
9979 logevent("Opened main channel");
9983 * Now we have a channel, make dispatch table entries for
9984 * general channel-based messages.
9986 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9988 ssh2_msg_channel_data;
9989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9990 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9991 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9992 ssh2_msg_channel_open_confirmation;
9993 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9994 ssh2_msg_channel_open_failure;
9995 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9996 ssh2_msg_channel_request;
9997 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9998 ssh2_msg_channel_open;
9999 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10000 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10003 * Now the connection protocol is properly up and running, with
10004 * all those dispatch table entries, so it's safe to let
10005 * downstreams start trying to open extra channels through us.
10007 if (ssh->connshare)
10008 share_activate(ssh->connshare, ssh->v_s);
10010 if (ssh->mainchan && ssh_is_simple(ssh)) {
10012 * This message indicates to the server that we promise
10013 * not to try to run any other channel in parallel with
10014 * this one, so it's safe for it to advertise a very large
10015 * window and leave the flow control to TCP.
10017 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10018 "simple@putty.projects.tartarus.org",
10020 ssh2_pkt_send(ssh, s->pktout);
10024 * Enable port forwardings.
10026 ssh_setup_portfwd(ssh, ssh->conf);
10028 if (ssh->mainchan && !ssh->ncmode) {
10030 * Send the CHANNEL_REQUESTS for the main session channel.
10031 * Each one is handled by its own little asynchronous
10035 /* Potentially enable X11 forwarding. */
10036 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10038 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10040 if (!ssh->x11disp) {
10041 /* FIXME: return an error message from x11_setup_display */
10042 logevent("X11 forwarding not enabled: unable to"
10043 " initialise X display");
10045 ssh->x11auth = x11_invent_fake_auth
10046 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10047 ssh->x11auth->disp = ssh->x11disp;
10049 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10053 /* Potentially enable agent forwarding. */
10054 if (ssh_agent_forwarding_permitted(ssh))
10055 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10057 /* Now allocate a pty for the session. */
10058 if (!conf_get_int(ssh->conf, CONF_nopty))
10059 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10061 /* Send environment variables. */
10062 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10065 * Start a shell or a remote command. We may have to attempt
10066 * this twice if the config data has provided a second choice
10073 if (ssh->fallback_cmd) {
10074 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10075 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10077 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10078 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10082 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10083 ssh2_response_authconn, NULL);
10084 ssh2_pkt_addstring(s->pktout, cmd);
10086 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10087 ssh2_response_authconn, NULL);
10088 ssh2_pkt_addstring(s->pktout, cmd);
10090 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10091 ssh2_response_authconn, NULL);
10093 ssh2_pkt_send(ssh, s->pktout);
10095 crWaitUntilV(pktin);
10097 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10098 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10099 bombout(("Unexpected response to shell/command request:"
10100 " packet type %d", pktin->type));
10104 * We failed to start the command. If this is the
10105 * fallback command, we really are finished; if it's
10106 * not, and if the fallback command exists, try falling
10107 * back to it before complaining.
10109 if (!ssh->fallback_cmd &&
10110 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10111 logevent("Primary command failed; attempting fallback");
10112 ssh->fallback_cmd = TRUE;
10115 bombout(("Server refused to start a shell/command"));
10118 logevent("Started a shell/command");
10123 ssh->editing = ssh->echoing = TRUE;
10126 ssh->state = SSH_STATE_SESSION;
10127 if (ssh->size_needed)
10128 ssh_size(ssh, ssh->term_width, ssh->term_height);
10129 if (ssh->eof_needed)
10130 ssh_special(ssh, TS_EOF);
10136 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10141 s->try_send = FALSE;
10145 * _All_ the connection-layer packets we expect to
10146 * receive are now handled by the dispatch table.
10147 * Anything that reaches here must be bogus.
10150 bombout(("Strange packet received: type %d", pktin->type));
10152 } else if (ssh->mainchan) {
10154 * We have spare data. Add it to the channel buffer.
10156 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10157 s->try_send = TRUE;
10161 struct ssh_channel *c;
10163 * Try to send data on all channels if we can.
10165 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10166 ssh2_try_send_and_unthrottle(ssh, c);
10174 * Handlers for SSH-2 messages that might arrive at any moment.
10176 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10178 /* log reason code in disconnect message */
10180 int reason, msglen;
10182 reason = ssh_pkt_getuint32(pktin);
10183 ssh_pkt_getstring(pktin, &msg, &msglen);
10185 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10186 buf = dupprintf("Received disconnect message (%s)",
10187 ssh2_disconnect_reasons[reason]);
10189 buf = dupprintf("Received disconnect message (unknown"
10190 " type %d)", reason);
10194 buf = dupprintf("Disconnection message text: %.*s",
10197 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10199 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10200 ssh2_disconnect_reasons[reason] : "unknown",
10205 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10207 /* log the debug message */
10211 /* XXX maybe we should actually take notice of the return value */
10212 ssh2_pkt_getbool(pktin);
10213 ssh_pkt_getstring(pktin, &msg, &msglen);
10215 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10218 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10220 do_ssh2_transport(ssh, NULL, 0, pktin);
10224 * Called if we receive a packet that isn't allowed by the protocol.
10225 * This only applies to packets whose meaning PuTTY understands.
10226 * Entirely unknown packets are handled below.
10228 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10230 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10231 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10233 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10237 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10239 struct Packet *pktout;
10240 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10241 ssh2_pkt_adduint32(pktout, pktin->sequence);
10243 * UNIMPLEMENTED messages MUST appear in the same order as the
10244 * messages they respond to. Hence, never queue them.
10246 ssh2_pkt_send_noqueue(ssh, pktout);
10250 * Handle the top-level SSH-2 protocol.
10252 static void ssh2_protocol_setup(Ssh ssh)
10257 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10259 for (i = 0; i < 256; i++)
10260 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10263 * Initially, we only accept transport messages (and a few generic
10264 * ones). do_ssh2_authconn will add more when it starts.
10265 * Messages that are understood but not currently acceptable go to
10266 * ssh2_msg_unexpected.
10268 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10269 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10270 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10271 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10272 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10273 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10274 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10275 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10276 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10277 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10278 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10279 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10280 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10281 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10282 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10283 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10284 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10285 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10286 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10287 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10288 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10289 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10290 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10291 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10292 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10293 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10294 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10295 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10298 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10300 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10303 * These messages have a special handler from the start.
10305 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10306 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10307 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10310 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10315 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10317 for (i = 0; i < 256; i++)
10318 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10321 * Initially, we set all ssh-connection messages to 'unexpected';
10322 * do_ssh2_authconn will fill things in properly. We also handle a
10323 * couple of messages from the transport protocol which aren't
10324 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10327 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10328 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10329 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10330 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10331 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10332 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10333 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10334 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10335 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10336 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10337 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10338 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10339 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10340 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10342 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10345 * These messages have a special handler from the start.
10347 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10348 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10349 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10352 static void ssh2_timer(void *ctx, unsigned long now)
10354 Ssh ssh = (Ssh)ctx;
10356 if (ssh->state == SSH_STATE_CLOSED)
10359 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10360 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10361 now == ssh->next_rekey) {
10362 do_ssh2_transport(ssh, "timeout", -1, NULL);
10366 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10367 struct Packet *pktin)
10369 unsigned char *in = (unsigned char *)vin;
10370 if (ssh->state == SSH_STATE_CLOSED)
10374 ssh->incoming_data_size += pktin->encrypted_len;
10375 if (!ssh->kex_in_progress &&
10376 ssh->max_data_size != 0 &&
10377 ssh->incoming_data_size > ssh->max_data_size)
10378 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10382 ssh->packet_dispatch[pktin->type](ssh, pktin);
10383 else if (!ssh->protocol_initial_phase_done)
10384 do_ssh2_transport(ssh, in, inlen, pktin);
10386 do_ssh2_authconn(ssh, in, inlen, pktin);
10389 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10390 struct Packet *pktin)
10392 unsigned char *in = (unsigned char *)vin;
10393 if (ssh->state == SSH_STATE_CLOSED)
10397 ssh->packet_dispatch[pktin->type](ssh, pktin);
10399 do_ssh2_authconn(ssh, in, inlen, pktin);
10402 static void ssh_cache_conf_values(Ssh ssh)
10404 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10408 * Called to set up the connection.
10410 * Returns an error message, or NULL on success.
10412 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10413 Conf *conf, char *host, int port, char **realhost,
10414 int nodelay, int keepalive)
10419 ssh = snew(struct ssh_tag);
10420 ssh->conf = conf_copy(conf);
10421 ssh_cache_conf_values(ssh);
10422 ssh->version = 0; /* when not ready yet */
10424 ssh->cipher = NULL;
10425 ssh->v1_cipher_ctx = NULL;
10426 ssh->crcda_ctx = NULL;
10427 ssh->cscipher = NULL;
10428 ssh->cs_cipher_ctx = NULL;
10429 ssh->sccipher = NULL;
10430 ssh->sc_cipher_ctx = NULL;
10432 ssh->cs_mac_ctx = NULL;
10434 ssh->sc_mac_ctx = NULL;
10435 ssh->cscomp = NULL;
10436 ssh->cs_comp_ctx = NULL;
10437 ssh->sccomp = NULL;
10438 ssh->sc_comp_ctx = NULL;
10440 ssh->kex_ctx = NULL;
10441 ssh->hostkey = NULL;
10442 ssh->hostkey_str = NULL;
10443 ssh->exitcode = -1;
10444 ssh->close_expected = FALSE;
10445 ssh->clean_exit = FALSE;
10446 ssh->state = SSH_STATE_PREPACKET;
10447 ssh->size_needed = FALSE;
10448 ssh->eof_needed = FALSE;
10450 ssh->logctx = NULL;
10451 ssh->deferred_send_data = NULL;
10452 ssh->deferred_len = 0;
10453 ssh->deferred_size = 0;
10454 ssh->fallback_cmd = 0;
10455 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10456 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10457 ssh->x11disp = NULL;
10458 ssh->x11auth = NULL;
10459 ssh->x11authtree = newtree234(x11_authcmp);
10460 ssh->v1_compressing = FALSE;
10461 ssh->v2_outgoing_sequence = 0;
10462 ssh->ssh1_rdpkt_crstate = 0;
10463 ssh->ssh2_rdpkt_crstate = 0;
10464 ssh->ssh2_bare_rdpkt_crstate = 0;
10465 ssh->ssh_gotdata_crstate = 0;
10466 ssh->do_ssh1_connection_crstate = 0;
10467 ssh->do_ssh_init_state = NULL;
10468 ssh->do_ssh_connection_init_state = NULL;
10469 ssh->do_ssh1_login_state = NULL;
10470 ssh->do_ssh2_transport_state = NULL;
10471 ssh->do_ssh2_authconn_state = NULL;
10474 ssh->mainchan = NULL;
10475 ssh->throttled_all = 0;
10476 ssh->v1_stdout_throttling = 0;
10478 ssh->queuelen = ssh->queuesize = 0;
10479 ssh->queueing = FALSE;
10480 ssh->qhead = ssh->qtail = NULL;
10481 ssh->deferred_rekey_reason = NULL;
10482 bufchain_init(&ssh->queued_incoming_data);
10483 ssh->frozen = FALSE;
10484 ssh->username = NULL;
10485 ssh->sent_console_eof = FALSE;
10486 ssh->got_pty = FALSE;
10487 ssh->bare_connection = FALSE;
10488 ssh->attempting_connshare = FALSE;
10490 *backend_handle = ssh;
10493 if (crypto_startup() == 0)
10494 return "Microsoft high encryption pack not installed!";
10497 ssh->frontend = frontend_handle;
10498 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10499 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10501 ssh->channels = NULL;
10502 ssh->rportfwds = NULL;
10503 ssh->portfwds = NULL;
10508 ssh->conn_throttle_count = 0;
10509 ssh->overall_bufsize = 0;
10510 ssh->fallback_cmd = 0;
10512 ssh->protocol = NULL;
10514 ssh->protocol_initial_phase_done = FALSE;
10516 ssh->pinger = NULL;
10518 ssh->incoming_data_size = ssh->outgoing_data_size =
10519 ssh->deferred_data_size = 0L;
10520 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10521 CONF_ssh_rekey_data));
10522 ssh->kex_in_progress = FALSE;
10525 ssh->gsslibs = NULL;
10528 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10537 static void ssh_free(void *handle)
10539 Ssh ssh = (Ssh) handle;
10540 struct ssh_channel *c;
10541 struct ssh_rportfwd *pf;
10542 struct X11FakeAuth *auth;
10544 if (ssh->v1_cipher_ctx)
10545 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10546 if (ssh->cs_cipher_ctx)
10547 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10548 if (ssh->sc_cipher_ctx)
10549 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10550 if (ssh->cs_mac_ctx)
10551 ssh->csmac->free_context(ssh->cs_mac_ctx);
10552 if (ssh->sc_mac_ctx)
10553 ssh->scmac->free_context(ssh->sc_mac_ctx);
10554 if (ssh->cs_comp_ctx) {
10556 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10558 zlib_compress_cleanup(ssh->cs_comp_ctx);
10560 if (ssh->sc_comp_ctx) {
10562 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10564 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10567 dh_cleanup(ssh->kex_ctx);
10568 sfree(ssh->savedhost);
10570 while (ssh->queuelen-- > 0)
10571 ssh_free_packet(ssh->queue[ssh->queuelen]);
10574 while (ssh->qhead) {
10575 struct queued_handler *qh = ssh->qhead;
10576 ssh->qhead = qh->next;
10579 ssh->qhead = ssh->qtail = NULL;
10581 if (ssh->channels) {
10582 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10585 if (c->u.x11.xconn != NULL)
10586 x11_close(c->u.x11.xconn);
10588 case CHAN_SOCKDATA:
10589 case CHAN_SOCKDATA_DORMANT:
10590 if (c->u.pfd.pf != NULL)
10591 pfd_close(c->u.pfd.pf);
10594 if (ssh->version == 2) {
10595 struct outstanding_channel_request *ocr, *nocr;
10596 ocr = c->v.v2.chanreq_head;
10598 ocr->handler(c, NULL, ocr->ctx);
10603 bufchain_clear(&c->v.v2.outbuffer);
10607 freetree234(ssh->channels);
10608 ssh->channels = NULL;
10611 if (ssh->connshare)
10612 sharestate_free(ssh->connshare);
10614 if (ssh->rportfwds) {
10615 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10617 freetree234(ssh->rportfwds);
10618 ssh->rportfwds = NULL;
10620 sfree(ssh->deferred_send_data);
10622 x11_free_display(ssh->x11disp);
10623 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10624 x11_free_fake_auth(auth);
10625 freetree234(ssh->x11authtree);
10626 sfree(ssh->do_ssh_init_state);
10627 sfree(ssh->do_ssh1_login_state);
10628 sfree(ssh->do_ssh2_transport_state);
10629 sfree(ssh->do_ssh2_authconn_state);
10632 sfree(ssh->fullhostname);
10633 sfree(ssh->hostkey_str);
10634 if (ssh->crcda_ctx) {
10635 crcda_free_context(ssh->crcda_ctx);
10636 ssh->crcda_ctx = NULL;
10639 ssh_do_close(ssh, TRUE);
10640 expire_timer_context(ssh);
10642 pinger_free(ssh->pinger);
10643 bufchain_clear(&ssh->queued_incoming_data);
10644 sfree(ssh->username);
10645 conf_free(ssh->conf);
10648 ssh_gss_cleanup(ssh->gsslibs);
10656 * Reconfigure the SSH backend.
10658 static void ssh_reconfig(void *handle, Conf *conf)
10660 Ssh ssh = (Ssh) handle;
10661 char *rekeying = NULL, rekey_mandatory = FALSE;
10662 unsigned long old_max_data_size;
10665 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10667 ssh_setup_portfwd(ssh, conf);
10669 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10670 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10672 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10673 unsigned long now = GETTICKCOUNT();
10675 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10676 rekeying = "timeout shortened";
10678 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10682 old_max_data_size = ssh->max_data_size;
10683 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10684 CONF_ssh_rekey_data));
10685 if (old_max_data_size != ssh->max_data_size &&
10686 ssh->max_data_size != 0) {
10687 if (ssh->outgoing_data_size > ssh->max_data_size ||
10688 ssh->incoming_data_size > ssh->max_data_size)
10689 rekeying = "data limit lowered";
10692 if (conf_get_int(ssh->conf, CONF_compression) !=
10693 conf_get_int(conf, CONF_compression)) {
10694 rekeying = "compression setting changed";
10695 rekey_mandatory = TRUE;
10698 for (i = 0; i < CIPHER_MAX; i++)
10699 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10700 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10701 rekeying = "cipher settings changed";
10702 rekey_mandatory = TRUE;
10704 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10705 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10706 rekeying = "cipher settings changed";
10707 rekey_mandatory = TRUE;
10710 conf_free(ssh->conf);
10711 ssh->conf = conf_copy(conf);
10712 ssh_cache_conf_values(ssh);
10714 if (!ssh->bare_connection && rekeying) {
10715 if (!ssh->kex_in_progress) {
10716 do_ssh2_transport(ssh, rekeying, -1, NULL);
10717 } else if (rekey_mandatory) {
10718 ssh->deferred_rekey_reason = rekeying;
10724 * Called to send data down the SSH connection.
10726 static int ssh_send(void *handle, char *buf, int len)
10728 Ssh ssh = (Ssh) handle;
10730 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10733 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10735 return ssh_sendbuffer(ssh);
10739 * Called to query the current amount of buffered stdin data.
10741 static int ssh_sendbuffer(void *handle)
10743 Ssh ssh = (Ssh) handle;
10744 int override_value;
10746 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10750 * If the SSH socket itself has backed up, add the total backup
10751 * size on that to any individual buffer on the stdin channel.
10753 override_value = 0;
10754 if (ssh->throttled_all)
10755 override_value = ssh->overall_bufsize;
10757 if (ssh->version == 1) {
10758 return override_value;
10759 } else if (ssh->version == 2) {
10760 if (!ssh->mainchan)
10761 return override_value;
10763 return (override_value +
10764 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10771 * Called to set the size of the window from SSH's POV.
10773 static void ssh_size(void *handle, int width, int height)
10775 Ssh ssh = (Ssh) handle;
10776 struct Packet *pktout;
10778 ssh->term_width = width;
10779 ssh->term_height = height;
10781 switch (ssh->state) {
10782 case SSH_STATE_BEFORE_SIZE:
10783 case SSH_STATE_PREPACKET:
10784 case SSH_STATE_CLOSED:
10785 break; /* do nothing */
10786 case SSH_STATE_INTERMED:
10787 ssh->size_needed = TRUE; /* buffer for later */
10789 case SSH_STATE_SESSION:
10790 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10791 if (ssh->version == 1) {
10792 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10793 PKT_INT, ssh->term_height,
10794 PKT_INT, ssh->term_width,
10795 PKT_INT, 0, PKT_INT, 0, PKT_END);
10796 } else if (ssh->mainchan) {
10797 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10799 ssh2_pkt_adduint32(pktout, ssh->term_width);
10800 ssh2_pkt_adduint32(pktout, ssh->term_height);
10801 ssh2_pkt_adduint32(pktout, 0);
10802 ssh2_pkt_adduint32(pktout, 0);
10803 ssh2_pkt_send(ssh, pktout);
10811 * Return a list of the special codes that make sense in this
10814 static const struct telnet_special *ssh_get_specials(void *handle)
10816 static const struct telnet_special ssh1_ignore_special[] = {
10817 {"IGNORE message", TS_NOP}
10819 static const struct telnet_special ssh2_ignore_special[] = {
10820 {"IGNORE message", TS_NOP},
10822 static const struct telnet_special ssh2_rekey_special[] = {
10823 {"Repeat key exchange", TS_REKEY},
10825 static const struct telnet_special ssh2_session_specials[] = {
10828 /* These are the signal names defined by RFC 4254.
10829 * They include all the ISO C signals, but are a subset of the POSIX
10830 * required signals. */
10831 {"SIGINT (Interrupt)", TS_SIGINT},
10832 {"SIGTERM (Terminate)", TS_SIGTERM},
10833 {"SIGKILL (Kill)", TS_SIGKILL},
10834 {"SIGQUIT (Quit)", TS_SIGQUIT},
10835 {"SIGHUP (Hangup)", TS_SIGHUP},
10836 {"More signals", TS_SUBMENU},
10837 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10838 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10839 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10840 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10841 {NULL, TS_EXITMENU}
10843 static const struct telnet_special specials_end[] = {
10844 {NULL, TS_EXITMENU}
10846 /* XXX review this length for any changes: */
10847 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10848 lenof(ssh2_rekey_special) +
10849 lenof(ssh2_session_specials) +
10850 lenof(specials_end)];
10851 Ssh ssh = (Ssh) handle;
10853 #define ADD_SPECIALS(name) \
10855 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10856 memcpy(&ssh_specials[i], name, sizeof name); \
10857 i += lenof(name); \
10860 if (ssh->version == 1) {
10861 /* Don't bother offering IGNORE if we've decided the remote
10862 * won't cope with it, since we wouldn't bother sending it if
10864 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10865 ADD_SPECIALS(ssh1_ignore_special);
10866 } else if (ssh->version == 2) {
10867 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10868 ADD_SPECIALS(ssh2_ignore_special);
10869 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10870 ADD_SPECIALS(ssh2_rekey_special);
10872 ADD_SPECIALS(ssh2_session_specials);
10873 } /* else we're not ready yet */
10876 ADD_SPECIALS(specials_end);
10877 return ssh_specials;
10881 #undef ADD_SPECIALS
10885 * Send special codes. TS_EOF is useful for `plink', so you
10886 * can send an EOF and collect resulting output (e.g. `plink
10889 static void ssh_special(void *handle, Telnet_Special code)
10891 Ssh ssh = (Ssh) handle;
10892 struct Packet *pktout;
10894 if (code == TS_EOF) {
10895 if (ssh->state != SSH_STATE_SESSION) {
10897 * Buffer the EOF in case we are pre-SESSION, so we can
10898 * send it as soon as we reach SESSION.
10900 if (code == TS_EOF)
10901 ssh->eof_needed = TRUE;
10904 if (ssh->version == 1) {
10905 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10906 } else if (ssh->mainchan) {
10907 sshfwd_write_eof(ssh->mainchan);
10908 ssh->send_ok = 0; /* now stop trying to read from stdin */
10910 logevent("Sent EOF message");
10911 } else if (code == TS_PING || code == TS_NOP) {
10912 if (ssh->state == SSH_STATE_CLOSED
10913 || ssh->state == SSH_STATE_PREPACKET) return;
10914 if (ssh->version == 1) {
10915 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10916 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10918 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10919 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10920 ssh2_pkt_addstring_start(pktout);
10921 ssh2_pkt_send_noqueue(ssh, pktout);
10924 } else if (code == TS_REKEY) {
10925 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10926 ssh->version == 2) {
10927 do_ssh2_transport(ssh, "at user request", -1, NULL);
10929 } else if (code == TS_BRK) {
10930 if (ssh->state == SSH_STATE_CLOSED
10931 || ssh->state == SSH_STATE_PREPACKET) return;
10932 if (ssh->version == 1) {
10933 logevent("Unable to send BREAK signal in SSH-1");
10934 } else if (ssh->mainchan) {
10935 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10936 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10937 ssh2_pkt_send(ssh, pktout);
10940 /* Is is a POSIX signal? */
10941 char *signame = NULL;
10942 if (code == TS_SIGABRT) signame = "ABRT";
10943 if (code == TS_SIGALRM) signame = "ALRM";
10944 if (code == TS_SIGFPE) signame = "FPE";
10945 if (code == TS_SIGHUP) signame = "HUP";
10946 if (code == TS_SIGILL) signame = "ILL";
10947 if (code == TS_SIGINT) signame = "INT";
10948 if (code == TS_SIGKILL) signame = "KILL";
10949 if (code == TS_SIGPIPE) signame = "PIPE";
10950 if (code == TS_SIGQUIT) signame = "QUIT";
10951 if (code == TS_SIGSEGV) signame = "SEGV";
10952 if (code == TS_SIGTERM) signame = "TERM";
10953 if (code == TS_SIGUSR1) signame = "USR1";
10954 if (code == TS_SIGUSR2) signame = "USR2";
10955 /* The SSH-2 protocol does in principle support arbitrary named
10956 * signals, including signame@domain, but we don't support those. */
10958 /* It's a signal. */
10959 if (ssh->version == 2 && ssh->mainchan) {
10960 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10961 ssh2_pkt_addstring(pktout, signame);
10962 ssh2_pkt_send(ssh, pktout);
10963 logeventf(ssh, "Sent signal SIG%s", signame);
10966 /* Never heard of it. Do nothing */
10971 void *new_sock_channel(void *handle, struct PortForwarding *pf)
10973 Ssh ssh = (Ssh) handle;
10974 struct ssh_channel *c;
10975 c = snew(struct ssh_channel);
10978 ssh2_channel_init(c);
10979 c->halfopen = TRUE;
10980 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10982 add234(ssh->channels, c);
10986 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
10988 struct ssh_channel *c;
10989 c = snew(struct ssh_channel);
10992 ssh2_channel_init(c);
10993 c->type = CHAN_SHARING;
10994 c->u.sharing.ctx = sharing_ctx;
10995 add234(ssh->channels, c);
10999 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11001 struct ssh_channel *c;
11003 c = find234(ssh->channels, &localid, ssh_channelfind);
11005 ssh_channel_destroy(c);
11008 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11009 const void *data, int datalen,
11010 const char *additional_log_text)
11012 struct Packet *pkt;
11014 pkt = ssh2_pkt_init(type);
11015 pkt->downstream_id = id;
11016 pkt->additional_log_text = additional_log_text;
11017 ssh2_pkt_adddata(pkt, data, datalen);
11018 ssh2_pkt_send(ssh, pkt);
11022 * This is called when stdout/stderr (the entity to which
11023 * from_backend sends data) manages to clear some backlog.
11025 static void ssh_unthrottle(void *handle, int bufsize)
11027 Ssh ssh = (Ssh) handle;
11030 if (ssh->version == 1) {
11031 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11032 ssh->v1_stdout_throttling = 0;
11033 ssh_throttle_conn(ssh, -1);
11036 if (ssh->mainchan) {
11037 ssh2_set_window(ssh->mainchan,
11038 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11039 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11040 if (ssh_is_simple(ssh))
11043 buflimit = ssh->mainchan->v.v2.locmaxwin;
11044 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11045 ssh->mainchan->throttling_conn = 0;
11046 ssh_throttle_conn(ssh, -1);
11052 * Now process any SSH connection data that was stashed in our
11053 * queue while we were frozen.
11055 ssh_process_queued_incoming_data(ssh);
11058 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11060 struct ssh_channel *c = (struct ssh_channel *)channel;
11062 struct Packet *pktout;
11064 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11066 if (ssh->version == 1) {
11067 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11068 PKT_INT, c->localid,
11071 /* PKT_STR, <org:orgport>, */
11074 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11076 char *trimmed_host = host_strduptrim(hostname);
11077 ssh2_pkt_addstring(pktout, trimmed_host);
11078 sfree(trimmed_host);
11080 ssh2_pkt_adduint32(pktout, port);
11082 * We make up values for the originator data; partly it's
11083 * too much hassle to keep track, and partly I'm not
11084 * convinced the server should be told details like that
11085 * about my local network configuration.
11086 * The "originator IP address" is syntactically a numeric
11087 * IP address, and some servers (e.g., Tectia) get upset
11088 * if it doesn't match this syntax.
11090 ssh2_pkt_addstring(pktout, "0.0.0.0");
11091 ssh2_pkt_adduint32(pktout, 0);
11092 ssh2_pkt_send(ssh, pktout);
11096 static int ssh_connected(void *handle)
11098 Ssh ssh = (Ssh) handle;
11099 return ssh->s != NULL;
11102 static int ssh_sendok(void *handle)
11104 Ssh ssh = (Ssh) handle;
11105 return ssh->send_ok;
11108 static int ssh_ldisc(void *handle, int option)
11110 Ssh ssh = (Ssh) handle;
11111 if (option == LD_ECHO)
11112 return ssh->echoing;
11113 if (option == LD_EDIT)
11114 return ssh->editing;
11118 static void ssh_provide_ldisc(void *handle, void *ldisc)
11120 Ssh ssh = (Ssh) handle;
11121 ssh->ldisc = ldisc;
11124 static void ssh_provide_logctx(void *handle, void *logctx)
11126 Ssh ssh = (Ssh) handle;
11127 ssh->logctx = logctx;
11130 static int ssh_return_exitcode(void *handle)
11132 Ssh ssh = (Ssh) handle;
11133 if (ssh->s != NULL)
11136 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11140 * cfg_info for SSH is the currently running version of the
11141 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
11143 static int ssh_cfg_info(void *handle)
11145 Ssh ssh = (Ssh) handle;
11146 return ssh->version;
11150 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11151 * that fails. This variable is the means by which scp.c can reach
11152 * into the SSH code and find out which one it got.
11154 extern int ssh_fallback_cmd(void *handle)
11156 Ssh ssh = (Ssh) handle;
11157 return ssh->fallback_cmd;
11160 Backend ssh_backend = {
11170 ssh_return_exitcode,
11174 ssh_provide_logctx,