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 configuration but "
2964 "not provided by server"));
2967 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2968 bombout(("SSH protocol version 2 required by configuration but "
2969 "not provided by server"));
2973 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2978 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2980 /* Send the version string, if we haven't already */
2981 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2982 ssh_send_verstring(ssh, protoname, s->version);
2984 if (ssh->version == 2) {
2987 * Record their version string.
2989 len = strcspn(s->vstring, "\015\012");
2990 ssh->v_s = snewn(len + 1, char);
2991 memcpy(ssh->v_s, s->vstring, len);
2995 * Initialise SSH-2 protocol.
2997 ssh->protocol = ssh2_protocol;
2998 ssh2_protocol_setup(ssh);
2999 ssh->s_rdpkt = ssh2_rdpkt;
3002 * Initialise SSH-1 protocol.
3004 ssh->protocol = ssh1_protocol;
3005 ssh1_protocol_setup(ssh);
3006 ssh->s_rdpkt = ssh1_rdpkt;
3008 if (ssh->version == 2)
3009 do_ssh2_transport(ssh, NULL, -1, NULL);
3011 update_specials_menu(ssh->frontend);
3012 ssh->state = SSH_STATE_BEFORE_SIZE;
3013 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3020 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3023 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3024 * the ssh-connection part, extracted and given a trivial binary
3025 * packet protocol, so we replace 'SSH-' at the start with a new
3026 * name. In proper SSH style (though of course this part of the
3027 * proper SSH protocol _isn't_ subject to this kind of
3028 * DNS-domain-based extension), we define the new name in our
3031 static const char protoname[] =
3032 "SSHCONNECTION@putty.projects.tartarus.org-";
3034 struct do_ssh_connection_init_state {
3042 crState(do_ssh_connection_init_state);
3046 /* Search for a line beginning with the protocol name prefix in
3049 for (s->i = 0; protoname[s->i]; s->i++) {
3050 if ((char)c != protoname[s->i]) goto no;
3060 s->vstrsize = sizeof(protoname) + 16;
3061 s->vstring = snewn(s->vstrsize, char);
3062 strcpy(s->vstring, protoname);
3063 s->vslen = strlen(protoname);
3066 if (s->vslen >= s->vstrsize - 1) {
3068 s->vstring = sresize(s->vstring, s->vstrsize, char);
3070 s->vstring[s->vslen++] = c;
3073 s->version[s->i] = '\0';
3075 } else if (s->i < sizeof(s->version) - 1)
3076 s->version[s->i++] = c;
3077 } else if (c == '\012')
3079 crReturn(1); /* get another char */
3082 ssh->agentfwd_enabled = FALSE;
3083 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3085 s->vstring[s->vslen] = 0;
3086 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3087 logeventf(ssh, "Server version: %s", s->vstring);
3088 ssh_detect_bugs(ssh, s->vstring);
3091 * Decide which SSH protocol version to support. This is easy in
3092 * bare ssh-connection mode: only 2.0 is legal.
3094 if (ssh_versioncmp(s->version, "2.0") < 0) {
3095 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3098 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3099 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3105 logeventf(ssh, "Using bare ssh-connection protocol");
3107 /* Send the version string, if we haven't already */
3108 ssh_send_verstring(ssh, protoname, s->version);
3111 * Initialise bare connection protocol.
3113 ssh->protocol = ssh2_bare_connection_protocol;
3114 ssh2_bare_connection_protocol_setup(ssh);
3115 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3117 update_specials_menu(ssh->frontend);
3118 ssh->state = SSH_STATE_BEFORE_SIZE;
3119 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3122 * Get authconn (really just conn) under way.
3124 do_ssh2_authconn(ssh, NULL, 0, NULL);
3131 static void ssh_process_incoming_data(Ssh ssh,
3132 unsigned char **data, int *datalen)
3134 struct Packet *pktin;
3136 pktin = ssh->s_rdpkt(ssh, data, datalen);
3138 ssh->protocol(ssh, NULL, 0, pktin);
3139 ssh_free_packet(pktin);
3143 static void ssh_queue_incoming_data(Ssh ssh,
3144 unsigned char **data, int *datalen)
3146 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3151 static void ssh_process_queued_incoming_data(Ssh ssh)
3154 unsigned char *data;
3157 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3158 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3162 while (!ssh->frozen && len > 0)
3163 ssh_process_incoming_data(ssh, &data, &len);
3166 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3170 static void ssh_set_frozen(Ssh ssh, int frozen)
3173 sk_set_frozen(ssh->s, frozen);
3174 ssh->frozen = frozen;
3177 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3179 /* Log raw data, if we're in that mode. */
3181 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3182 0, NULL, NULL, 0, NULL);
3184 crBegin(ssh->ssh_gotdata_crstate);
3187 * To begin with, feed the characters one by one to the
3188 * protocol initialisation / selection function do_ssh_init().
3189 * When that returns 0, we're done with the initial greeting
3190 * exchange and can move on to packet discipline.
3193 int ret; /* need not be kept across crReturn */
3195 crReturnV; /* more data please */
3196 ret = ssh->do_ssh_init(ssh, *data);
3204 * We emerge from that loop when the initial negotiation is
3205 * over and we have selected an s_rdpkt function. Now pass
3206 * everything to s_rdpkt, and then pass the resulting packets
3207 * to the proper protocol handler.
3211 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3213 ssh_queue_incoming_data(ssh, &data, &datalen);
3214 /* This uses up all data and cannot cause anything interesting
3215 * to happen; indeed, for anything to happen at all, we must
3216 * return, so break out. */
3218 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3219 /* This uses up some or all data, and may freeze the
3221 ssh_process_queued_incoming_data(ssh);
3223 /* This uses up some or all data, and may freeze the
3225 ssh_process_incoming_data(ssh, &data, &datalen);
3227 /* FIXME this is probably EBW. */
3228 if (ssh->state == SSH_STATE_CLOSED)
3231 /* We're out of data. Go and get some more. */
3237 static int ssh_do_close(Ssh ssh, int notify_exit)
3240 struct ssh_channel *c;
3242 ssh->state = SSH_STATE_CLOSED;
3243 expire_timer_context(ssh);
3248 notify_remote_exit(ssh->frontend);
3253 * Now we must shut down any port- and X-forwarded channels going
3254 * through this connection.
3256 if (ssh->channels) {
3257 while (NULL != (c = index234(ssh->channels, 0))) {
3260 x11_close(c->u.x11.xconn);
3263 case CHAN_SOCKDATA_DORMANT:
3264 pfd_close(c->u.pfd.pf);
3267 del234(ssh->channels, c); /* moving next one to index 0 */
3268 if (ssh->version == 2)
3269 bufchain_clear(&c->v.v2.outbuffer);
3274 * Go through port-forwardings, and close any associated
3275 * listening sockets.
3277 if (ssh->portfwds) {
3278 struct ssh_portfwd *pf;
3279 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3280 /* Dispose of any listening socket. */
3282 pfl_terminate(pf->local);
3283 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3286 freetree234(ssh->portfwds);
3287 ssh->portfwds = NULL;
3291 * Also stop attempting to connection-share.
3293 if (ssh->connshare) {
3294 sharestate_free(ssh->connshare);
3295 ssh->connshare = NULL;
3301 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3302 const char *error_msg, int error_code)
3304 Ssh ssh = (Ssh) plug;
3305 char addrbuf[256], *msg;
3307 if (ssh->attempting_connshare) {
3309 * While we're attempting connection sharing, don't loudly log
3310 * everything that happens. Real TCP connections need to be
3311 * logged when we _start_ trying to connect, because it might
3312 * be ages before they respond if something goes wrong; but
3313 * connection sharing is local and quick to respond, and it's
3314 * sufficient to simply wait and see whether it worked
3318 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3321 if (sk_addr_needs_port(addr)) {
3322 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3324 msg = dupprintf("Connecting to %s", addrbuf);
3327 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3335 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3336 const char *ds_err, const char *us_err)
3338 if (event == SHARE_NONE) {
3339 /* In this case, 'logtext' is an error message indicating a
3340 * reason why connection sharing couldn't be set up _at all_.
3341 * Failing that, ds_err and us_err indicate why we couldn't be
3342 * a downstream and an upstream respectively. */
3344 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3347 logeventf(ssh, "Could not set up connection sharing"
3348 " as downstream: %s", ds_err);
3350 logeventf(ssh, "Could not set up connection sharing"
3351 " as upstream: %s", us_err);
3353 } else if (event == SHARE_DOWNSTREAM) {
3354 /* In this case, 'logtext' is a local endpoint address */
3355 logeventf(ssh, "Using existing shared connection at %s", logtext);
3356 /* Also we should mention this in the console window to avoid
3357 * confusing users as to why this window doesn't behave the
3359 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3360 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3362 } else if (event == SHARE_UPSTREAM) {
3363 /* In this case, 'logtext' is a local endpoint address too */
3364 logeventf(ssh, "Sharing this connection at %s", logtext);
3368 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3371 Ssh ssh = (Ssh) plug;
3372 int need_notify = ssh_do_close(ssh, FALSE);
3375 if (!ssh->close_expected)
3376 error_msg = "Server unexpectedly closed network connection";
3378 error_msg = "Server closed network connection";
3381 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3385 notify_remote_exit(ssh->frontend);
3388 logevent(error_msg);
3389 if (!ssh->close_expected || !ssh->clean_exit)
3390 connection_fatal(ssh->frontend, "%s", error_msg);
3394 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3396 Ssh ssh = (Ssh) plug;
3397 ssh_gotdata(ssh, (unsigned char *)data, len);
3398 if (ssh->state == SSH_STATE_CLOSED) {
3399 ssh_do_close(ssh, TRUE);
3405 static void ssh_sent(Plug plug, int bufsize)
3407 Ssh ssh = (Ssh) plug;
3409 * If the send backlog on the SSH socket itself clears, we
3410 * should unthrottle the whole world if it was throttled.
3412 if (bufsize < SSH_MAX_BACKLOG)
3413 ssh_throttle_all(ssh, 0, bufsize);
3417 * Connect to specified host and port.
3418 * Returns an error message, or NULL on success.
3419 * Also places the canonical host name into `realhost'. It must be
3420 * freed by the caller.
3422 static const char *connect_to_host(Ssh ssh, char *host, int port,
3423 char **realhost, int nodelay, int keepalive)
3425 static const struct plug_function_table fn_table = {
3436 int addressfamily, sshprot;
3438 loghost = conf_get_str(ssh->conf, CONF_loghost);
3443 tmphost = dupstr(loghost);
3444 ssh->savedport = 22; /* default ssh port */
3447 * A colon suffix on the hostname string also lets us affect
3448 * savedport. (Unless there are multiple colons, in which case
3449 * we assume this is an unbracketed IPv6 literal.)
3451 colon = host_strrchr(tmphost, ':');
3452 if (colon && colon == host_strchr(tmphost, ':')) {
3455 ssh->savedport = atoi(colon);
3458 ssh->savedhost = host_strduptrim(tmphost);
3461 ssh->savedhost = host_strduptrim(host);
3463 port = 22; /* default ssh port */
3464 ssh->savedport = port;
3467 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3470 * Try connection-sharing, in case that means we don't open a
3471 * socket after all. ssh_connection_sharing_init will connect to a
3472 * previously established upstream if it can, and failing that,
3473 * establish a listening socket for _us_ to be the upstream. In
3474 * the latter case it will return NULL just as if it had done
3475 * nothing, because here we only need to care if we're a
3476 * downstream and need to do our connection setup differently.
3478 ssh->connshare = NULL;
3479 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3480 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3481 ssh->conf, ssh, &ssh->connshare);
3482 ssh->attempting_connshare = FALSE;
3483 if (ssh->s != NULL) {
3485 * We are a downstream.
3487 ssh->bare_connection = TRUE;
3488 ssh->do_ssh_init = do_ssh_connection_init;
3489 ssh->fullhostname = NULL;
3490 *realhost = dupstr(host); /* best we can do */
3493 * We're not a downstream, so open a normal socket.
3495 ssh->do_ssh_init = do_ssh_init;
3500 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3501 logeventf(ssh, "Looking up host \"%s\"%s", host,
3502 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3503 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3504 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3505 if ((err = sk_addr_error(addr)) != NULL) {
3509 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3511 ssh->s = new_connection(addr, *realhost, port,
3512 0, 1, nodelay, keepalive,
3513 (Plug) ssh, ssh->conf);
3514 if ((err = sk_socket_error(ssh->s)) != NULL) {
3516 notify_remote_exit(ssh->frontend);
3522 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3523 * send the version string too.
3525 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3528 if (sshprot == 3 && !ssh->bare_connection) {
3530 ssh_send_verstring(ssh, "SSH-", NULL);
3534 * loghost, if configured, overrides realhost.
3538 *realhost = dupstr(loghost);
3545 * Throttle or unthrottle the SSH connection.
3547 static void ssh_throttle_conn(Ssh ssh, int adjust)
3549 int old_count = ssh->conn_throttle_count;
3550 ssh->conn_throttle_count += adjust;
3551 assert(ssh->conn_throttle_count >= 0);
3552 if (ssh->conn_throttle_count && !old_count) {
3553 ssh_set_frozen(ssh, 1);
3554 } else if (!ssh->conn_throttle_count && old_count) {
3555 ssh_set_frozen(ssh, 0);
3560 * Throttle or unthrottle _all_ local data streams (for when sends
3561 * on the SSH connection itself back up).
3563 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3566 struct ssh_channel *c;
3568 if (enable == ssh->throttled_all)
3570 ssh->throttled_all = enable;
3571 ssh->overall_bufsize = bufsize;
3574 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3576 case CHAN_MAINSESSION:
3578 * This is treated separately, outside the switch.
3582 x11_override_throttle(c->u.x11.xconn, enable);
3585 /* Agent channels require no buffer management. */
3588 pfd_override_throttle(c->u.pfd.pf, enable);
3594 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3596 Ssh ssh = (Ssh) sshv;
3598 ssh->agent_response = reply;
3599 ssh->agent_response_len = replylen;
3601 if (ssh->version == 1)
3602 do_ssh1_login(ssh, NULL, -1, NULL);
3604 do_ssh2_authconn(ssh, NULL, -1, NULL);
3607 static void ssh_dialog_callback(void *sshv, int ret)
3609 Ssh ssh = (Ssh) sshv;
3611 ssh->user_response = ret;
3613 if (ssh->version == 1)
3614 do_ssh1_login(ssh, NULL, -1, NULL);
3616 do_ssh2_transport(ssh, NULL, -1, NULL);
3619 * This may have unfrozen the SSH connection, so do a
3622 ssh_process_queued_incoming_data(ssh);
3625 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3627 struct ssh_channel *c = (struct ssh_channel *)cv;
3629 void *sentreply = reply;
3631 c->u.a.outstanding_requests--;
3633 /* Fake SSH_AGENT_FAILURE. */
3634 sentreply = "\0\0\0\1\5";
3637 if (ssh->version == 2) {
3638 ssh2_add_channel_data(c, sentreply, replylen);
3641 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3642 PKT_INT, c->remoteid,
3644 PKT_DATA, sentreply, replylen,
3650 * If we've already seen an incoming EOF but haven't sent an
3651 * outgoing one, this may be the moment to send it.
3653 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3654 sshfwd_write_eof(c);
3658 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3659 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3660 * => log `wire_reason'.
3662 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3663 int code, int clean_exit)
3667 client_reason = wire_reason;
3669 error = dupprintf("Disconnected: %s", client_reason);
3671 error = dupstr("Disconnected");
3673 if (ssh->version == 1) {
3674 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3676 } else if (ssh->version == 2) {
3677 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3678 ssh2_pkt_adduint32(pktout, code);
3679 ssh2_pkt_addstring(pktout, wire_reason);
3680 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3681 ssh2_pkt_send_noqueue(ssh, pktout);
3684 ssh->close_expected = TRUE;
3685 ssh->clean_exit = clean_exit;
3686 ssh_closing((Plug)ssh, error, 0, 0);
3690 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3691 const struct ssh_signkey *ssh2keytype,
3694 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3695 return -1; /* no manual keys configured */
3700 * The fingerprint string we've been given will have things
3701 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3702 * narrow down to just the colon-separated hex block at the
3703 * end of the string.
3705 const char *p = strrchr(fingerprint, ' ');
3706 fingerprint = p ? p+1 : fingerprint;
3707 /* Quick sanity checks, including making sure it's in lowercase */
3708 assert(strlen(fingerprint) == 16*3 - 1);
3709 assert(fingerprint[2] == ':');
3710 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3712 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3714 return 1; /* success */
3719 * Construct the base64-encoded public key blob and see if
3722 unsigned char *binblob;
3724 int binlen, atoms, i;
3725 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3726 atoms = (binlen + 2) / 3;
3727 base64blob = snewn(atoms * 4 + 1, char);
3728 for (i = 0; i < atoms; i++)
3729 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3730 base64blob[atoms * 4] = '\0';
3732 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3735 return 1; /* success */
3744 * Handle the key exchange and user authentication phases.
3746 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3747 struct Packet *pktin)
3750 unsigned char cookie[8], *ptr;
3751 struct MD5Context md5c;
3752 struct do_ssh1_login_state {
3755 unsigned char *rsabuf, *keystr1, *keystr2;
3756 unsigned long supported_ciphers_mask, supported_auths_mask;
3757 int tried_publickey, tried_agent;
3758 int tis_auth_refused, ccard_auth_refused;
3759 unsigned char session_id[16];
3761 void *publickey_blob;
3762 int publickey_bloblen;
3763 char *publickey_comment;
3764 int publickey_encrypted;
3765 prompts_t *cur_prompt;
3768 unsigned char request[5], *response, *p;
3778 struct RSAKey servkey, hostkey;
3780 crState(do_ssh1_login_state);
3787 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3788 bombout(("Public key packet not received"));
3792 logevent("Received public keys");
3794 ptr = ssh_pkt_getdata(pktin, 8);
3796 bombout(("SSH-1 public key packet stopped before random cookie"));
3799 memcpy(cookie, ptr, 8);
3801 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3802 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3803 bombout(("Failed to read SSH-1 public keys from public key packet"));
3808 * Log the host key fingerprint.
3812 logevent("Host key fingerprint is:");
3813 strcpy(logmsg, " ");
3814 s->hostkey.comment = NULL;
3815 rsa_fingerprint(logmsg + strlen(logmsg),
3816 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3820 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3821 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3822 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3823 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3824 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3826 ssh->v1_local_protoflags =
3827 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3828 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3831 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3832 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3833 MD5Update(&md5c, cookie, 8);
3834 MD5Final(s->session_id, &md5c);
3836 for (i = 0; i < 32; i++)
3837 ssh->session_key[i] = random_byte();
3840 * Verify that the `bits' and `bytes' parameters match.
3842 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3843 s->servkey.bits > s->servkey.bytes * 8) {
3844 bombout(("SSH-1 public keys were badly formatted"));
3848 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3849 s->hostkey.bytes : s->servkey.bytes);
3851 s->rsabuf = snewn(s->len, unsigned char);
3854 * Verify the host key.
3858 * First format the key into a string.
3860 int len = rsastr_len(&s->hostkey);
3861 char fingerprint[100];
3862 char *keystr = snewn(len, char);
3863 rsastr_fmt(keystr, &s->hostkey);
3864 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3866 /* First check against manually configured host keys. */
3867 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3868 if (s->dlgret == 0) { /* did not match */
3869 bombout(("Host key did not appear in manually configured list"));
3872 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3873 ssh_set_frozen(ssh, 1);
3874 s->dlgret = verify_ssh_host_key(ssh->frontend,
3875 ssh->savedhost, ssh->savedport,
3876 "rsa", keystr, fingerprint,
3877 ssh_dialog_callback, ssh);
3879 if (s->dlgret < 0) {
3883 bombout(("Unexpected data from server while waiting"
3884 " for user host key response"));
3887 } while (pktin || inlen > 0);
3888 s->dlgret = ssh->user_response;
3890 ssh_set_frozen(ssh, 0);
3892 if (s->dlgret == 0) {
3893 ssh_disconnect(ssh, "User aborted at host key verification",
3902 for (i = 0; i < 32; i++) {
3903 s->rsabuf[i] = ssh->session_key[i];
3905 s->rsabuf[i] ^= s->session_id[i];
3908 if (s->hostkey.bytes > s->servkey.bytes) {
3909 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3911 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3913 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3915 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3918 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3922 logevent("Encrypted session key");
3925 int cipher_chosen = 0, warn = 0;
3926 char *cipher_string = NULL;
3928 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3929 int next_cipher = conf_get_int_int(ssh->conf,
3930 CONF_ssh_cipherlist, i);
3931 if (next_cipher == CIPHER_WARN) {
3932 /* If/when we choose a cipher, warn about it */
3934 } else if (next_cipher == CIPHER_AES) {
3935 /* XXX Probably don't need to mention this. */
3936 logevent("AES not supported in SSH-1, skipping");
3938 switch (next_cipher) {
3939 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3940 cipher_string = "3DES"; break;
3941 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3942 cipher_string = "Blowfish"; break;
3943 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3944 cipher_string = "single-DES"; break;
3946 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3950 if (!cipher_chosen) {
3951 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3952 bombout(("Server violates SSH-1 protocol by not "
3953 "supporting 3DES encryption"));
3955 /* shouldn't happen */
3956 bombout(("No supported ciphers found"));
3960 /* Warn about chosen cipher if necessary. */
3962 ssh_set_frozen(ssh, 1);
3963 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3964 ssh_dialog_callback, ssh);
3965 if (s->dlgret < 0) {
3969 bombout(("Unexpected data from server while waiting"
3970 " for user response"));
3973 } while (pktin || inlen > 0);
3974 s->dlgret = ssh->user_response;
3976 ssh_set_frozen(ssh, 0);
3977 if (s->dlgret == 0) {
3978 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3985 switch (s->cipher_type) {
3986 case SSH_CIPHER_3DES:
3987 logevent("Using 3DES encryption");
3989 case SSH_CIPHER_DES:
3990 logevent("Using single-DES encryption");
3992 case SSH_CIPHER_BLOWFISH:
3993 logevent("Using Blowfish encryption");
3997 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3998 PKT_CHAR, s->cipher_type,
3999 PKT_DATA, cookie, 8,
4000 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4001 PKT_DATA, s->rsabuf, s->len,
4002 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4004 logevent("Trying to enable encryption...");
4008 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4009 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4011 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4012 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4013 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4015 ssh->crcda_ctx = crcda_make_context();
4016 logevent("Installing CRC compensation attack detector");
4018 if (s->servkey.modulus) {
4019 sfree(s->servkey.modulus);
4020 s->servkey.modulus = NULL;
4022 if (s->servkey.exponent) {
4023 sfree(s->servkey.exponent);
4024 s->servkey.exponent = NULL;
4026 if (s->hostkey.modulus) {
4027 sfree(s->hostkey.modulus);
4028 s->hostkey.modulus = NULL;
4030 if (s->hostkey.exponent) {
4031 sfree(s->hostkey.exponent);
4032 s->hostkey.exponent = NULL;
4036 if (pktin->type != SSH1_SMSG_SUCCESS) {
4037 bombout(("Encryption not successfully enabled"));
4041 logevent("Successfully started encryption");
4043 fflush(stdout); /* FIXME eh? */
4045 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4046 int ret; /* need not be kept over crReturn */
4047 s->cur_prompt = new_prompts(ssh->frontend);
4048 s->cur_prompt->to_server = TRUE;
4049 s->cur_prompt->name = dupstr("SSH login name");
4050 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4051 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4054 crWaitUntil(!pktin);
4055 ret = get_userpass_input(s->cur_prompt, in, inlen);
4060 * Failed to get a username. Terminate.
4062 free_prompts(s->cur_prompt);
4063 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4066 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4067 free_prompts(s->cur_prompt);
4070 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4072 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4074 if (flags & FLAG_INTERACTIVE &&
4075 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4076 c_write_str(ssh, userlog);
4077 c_write_str(ssh, "\r\n");
4085 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4086 /* We must not attempt PK auth. Pretend we've already tried it. */
4087 s->tried_publickey = s->tried_agent = 1;
4089 s->tried_publickey = s->tried_agent = 0;
4091 s->tis_auth_refused = s->ccard_auth_refused = 0;
4093 * Load the public half of any configured keyfile for later use.
4095 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4096 if (!filename_is_null(s->keyfile)) {
4098 logeventf(ssh, "Reading private key file \"%.150s\"",
4099 filename_to_str(s->keyfile));
4100 keytype = key_type(s->keyfile);
4101 if (keytype == SSH_KEYTYPE_SSH1) {
4103 if (rsakey_pubblob(s->keyfile,
4104 &s->publickey_blob, &s->publickey_bloblen,
4105 &s->publickey_comment, &error)) {
4106 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4110 logeventf(ssh, "Unable to load private key (%s)", error);
4111 msgbuf = dupprintf("Unable to load private key file "
4112 "\"%.150s\" (%s)\r\n",
4113 filename_to_str(s->keyfile),
4115 c_write_str(ssh, msgbuf);
4117 s->publickey_blob = NULL;
4121 logeventf(ssh, "Unable to use this key file (%s)",
4122 key_type_to_str(keytype));
4123 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4125 filename_to_str(s->keyfile),
4126 key_type_to_str(keytype));
4127 c_write_str(ssh, msgbuf);
4129 s->publickey_blob = NULL;
4132 s->publickey_blob = NULL;
4134 while (pktin->type == SSH1_SMSG_FAILURE) {
4135 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4137 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4139 * Attempt RSA authentication using Pageant.
4145 logevent("Pageant is running. Requesting keys.");
4147 /* Request the keys held by the agent. */
4148 PUT_32BIT(s->request, 1);
4149 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4150 if (!agent_query(s->request, 5, &r, &s->responselen,
4151 ssh_agent_callback, ssh)) {
4155 bombout(("Unexpected data from server while waiting"
4156 " for agent response"));
4159 } while (pktin || inlen > 0);
4160 r = ssh->agent_response;
4161 s->responselen = ssh->agent_response_len;
4163 s->response = (unsigned char *) r;
4164 if (s->response && s->responselen >= 5 &&
4165 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4166 s->p = s->response + 5;
4167 s->nkeys = toint(GET_32BIT(s->p));
4169 logeventf(ssh, "Pageant reported negative key count %d",
4174 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4175 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4176 unsigned char *pkblob = s->p;
4180 do { /* do while (0) to make breaking easy */
4181 n = ssh1_read_bignum
4182 (s->p, toint(s->responselen-(s->p-s->response)),
4187 n = ssh1_read_bignum
4188 (s->p, toint(s->responselen-(s->p-s->response)),
4193 if (s->responselen - (s->p-s->response) < 4)
4195 s->commentlen = toint(GET_32BIT(s->p));
4197 if (s->commentlen < 0 ||
4198 toint(s->responselen - (s->p-s->response)) <
4201 s->commentp = (char *)s->p;
4202 s->p += s->commentlen;
4206 logevent("Pageant key list packet was truncated");
4210 if (s->publickey_blob) {
4211 if (!memcmp(pkblob, s->publickey_blob,
4212 s->publickey_bloblen)) {
4213 logeventf(ssh, "Pageant key #%d matches "
4214 "configured key file", s->keyi);
4215 s->tried_publickey = 1;
4217 /* Skip non-configured key */
4220 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4221 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4222 PKT_BIGNUM, s->key.modulus, PKT_END);
4224 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4225 logevent("Key refused");
4228 logevent("Received RSA challenge");
4229 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4230 bombout(("Server's RSA challenge was badly formatted"));
4235 char *agentreq, *q, *ret;
4238 len = 1 + 4; /* message type, bit count */
4239 len += ssh1_bignum_length(s->key.exponent);
4240 len += ssh1_bignum_length(s->key.modulus);
4241 len += ssh1_bignum_length(s->challenge);
4242 len += 16; /* session id */
4243 len += 4; /* response format */
4244 agentreq = snewn(4 + len, char);
4245 PUT_32BIT(agentreq, len);
4247 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4248 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4250 q += ssh1_write_bignum(q, s->key.exponent);
4251 q += ssh1_write_bignum(q, s->key.modulus);
4252 q += ssh1_write_bignum(q, s->challenge);
4253 memcpy(q, s->session_id, 16);
4255 PUT_32BIT(q, 1); /* response format */
4256 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4257 ssh_agent_callback, ssh)) {
4262 bombout(("Unexpected data from server"
4263 " while waiting for agent"
4267 } while (pktin || inlen > 0);
4268 vret = ssh->agent_response;
4269 retlen = ssh->agent_response_len;
4274 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4275 logevent("Sending Pageant's response");
4276 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4277 PKT_DATA, ret + 5, 16,
4281 if (pktin->type == SSH1_SMSG_SUCCESS) {
4283 ("Pageant's response accepted");
4284 if (flags & FLAG_VERBOSE) {
4285 c_write_str(ssh, "Authenticated using"
4287 c_write(ssh, s->commentp,
4289 c_write_str(ssh, "\" from agent\r\n");
4294 ("Pageant's response not accepted");
4297 ("Pageant failed to answer challenge");
4301 logevent("No reply received from Pageant");
4304 freebn(s->key.exponent);
4305 freebn(s->key.modulus);
4306 freebn(s->challenge);
4311 if (s->publickey_blob && !s->tried_publickey)
4312 logevent("Configured key file not in Pageant");
4314 logevent("Failed to get reply from Pageant");
4319 if (s->publickey_blob && !s->tried_publickey) {
4321 * Try public key authentication with the specified
4324 int got_passphrase; /* need not be kept over crReturn */
4325 if (flags & FLAG_VERBOSE)
4326 c_write_str(ssh, "Trying public key authentication.\r\n");
4327 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4328 logeventf(ssh, "Trying public key \"%s\"",
4329 filename_to_str(s->keyfile));
4330 s->tried_publickey = 1;
4331 got_passphrase = FALSE;
4332 while (!got_passphrase) {
4334 * Get a passphrase, if necessary.
4336 char *passphrase = NULL; /* only written after crReturn */
4338 if (!s->publickey_encrypted) {
4339 if (flags & FLAG_VERBOSE)
4340 c_write_str(ssh, "No passphrase required.\r\n");
4343 int ret; /* need not be kept over crReturn */
4344 s->cur_prompt = new_prompts(ssh->frontend);
4345 s->cur_prompt->to_server = FALSE;
4346 s->cur_prompt->name = dupstr("SSH key passphrase");
4347 add_prompt(s->cur_prompt,
4348 dupprintf("Passphrase for key \"%.100s\": ",
4349 s->publickey_comment), FALSE);
4350 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4353 crWaitUntil(!pktin);
4354 ret = get_userpass_input(s->cur_prompt, in, inlen);
4358 /* Failed to get a passphrase. Terminate. */
4359 free_prompts(s->cur_prompt);
4360 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4364 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4365 free_prompts(s->cur_prompt);
4368 * Try decrypting key with passphrase.
4370 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4371 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4374 smemclr(passphrase, strlen(passphrase));
4378 /* Correct passphrase. */
4379 got_passphrase = TRUE;
4380 } else if (ret == 0) {
4381 c_write_str(ssh, "Couldn't load private key from ");
4382 c_write_str(ssh, filename_to_str(s->keyfile));
4383 c_write_str(ssh, " (");
4384 c_write_str(ssh, error);
4385 c_write_str(ssh, ").\r\n");
4386 got_passphrase = FALSE;
4387 break; /* go and try something else */
4388 } else if (ret == -1) {
4389 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4390 got_passphrase = FALSE;
4393 assert(0 && "unexpected return from loadrsakey()");
4394 got_passphrase = FALSE; /* placate optimisers */
4398 if (got_passphrase) {
4401 * Send a public key attempt.
4403 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4404 PKT_BIGNUM, s->key.modulus, PKT_END);
4407 if (pktin->type == SSH1_SMSG_FAILURE) {
4408 c_write_str(ssh, "Server refused our public key.\r\n");
4409 continue; /* go and try something else */
4411 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4412 bombout(("Bizarre response to offer of public key"));
4418 unsigned char buffer[32];
4419 Bignum challenge, response;
4421 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4422 bombout(("Server's RSA challenge was badly formatted"));
4425 response = rsadecrypt(challenge, &s->key);
4426 freebn(s->key.private_exponent);/* burn the evidence */
4428 for (i = 0; i < 32; i++) {
4429 buffer[i] = bignum_byte(response, 31 - i);
4433 MD5Update(&md5c, buffer, 32);
4434 MD5Update(&md5c, s->session_id, 16);
4435 MD5Final(buffer, &md5c);
4437 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4438 PKT_DATA, buffer, 16, PKT_END);
4445 if (pktin->type == SSH1_SMSG_FAILURE) {
4446 if (flags & FLAG_VERBOSE)
4447 c_write_str(ssh, "Failed to authenticate with"
4448 " our public key.\r\n");
4449 continue; /* go and try something else */
4450 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4451 bombout(("Bizarre response to RSA authentication response"));
4455 break; /* we're through! */
4461 * Otherwise, try various forms of password-like authentication.
4463 s->cur_prompt = new_prompts(ssh->frontend);
4465 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4466 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4467 !s->tis_auth_refused) {
4468 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4469 logevent("Requested TIS authentication");
4470 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4472 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4473 logevent("TIS authentication declined");
4474 if (flags & FLAG_INTERACTIVE)
4475 c_write_str(ssh, "TIS authentication refused.\r\n");
4476 s->tis_auth_refused = 1;
4481 char *instr_suf, *prompt;
4483 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4485 bombout(("TIS challenge packet was badly formed"));
4488 logevent("Received TIS challenge");
4489 s->cur_prompt->to_server = TRUE;
4490 s->cur_prompt->name = dupstr("SSH TIS authentication");
4491 /* Prompt heuristic comes from OpenSSH */
4492 if (memchr(challenge, '\n', challengelen)) {
4493 instr_suf = dupstr("");
4494 prompt = dupprintf("%.*s", challengelen, challenge);
4496 instr_suf = dupprintf("%.*s", challengelen, challenge);
4497 prompt = dupstr("Response: ");
4499 s->cur_prompt->instruction =
4500 dupprintf("Using TIS authentication.%s%s",
4501 (*instr_suf) ? "\n" : "",
4503 s->cur_prompt->instr_reqd = TRUE;
4504 add_prompt(s->cur_prompt, prompt, FALSE);
4508 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4509 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4510 !s->ccard_auth_refused) {
4511 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4512 logevent("Requested CryptoCard authentication");
4513 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4515 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4516 logevent("CryptoCard authentication declined");
4517 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4518 s->ccard_auth_refused = 1;
4523 char *instr_suf, *prompt;
4525 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4527 bombout(("CryptoCard challenge packet was badly formed"));
4530 logevent("Received CryptoCard challenge");
4531 s->cur_prompt->to_server = TRUE;
4532 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4533 s->cur_prompt->name_reqd = FALSE;
4534 /* Prompt heuristic comes from OpenSSH */
4535 if (memchr(challenge, '\n', challengelen)) {
4536 instr_suf = dupstr("");
4537 prompt = dupprintf("%.*s", challengelen, challenge);
4539 instr_suf = dupprintf("%.*s", challengelen, challenge);
4540 prompt = dupstr("Response: ");
4542 s->cur_prompt->instruction =
4543 dupprintf("Using CryptoCard authentication.%s%s",
4544 (*instr_suf) ? "\n" : "",
4546 s->cur_prompt->instr_reqd = TRUE;
4547 add_prompt(s->cur_prompt, prompt, FALSE);
4551 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4552 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4553 bombout(("No supported authentication methods available"));
4556 s->cur_prompt->to_server = TRUE;
4557 s->cur_prompt->name = dupstr("SSH password");
4558 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4559 ssh->username, ssh->savedhost),
4564 * Show password prompt, having first obtained it via a TIS
4565 * or CryptoCard exchange if we're doing TIS or CryptoCard
4569 int ret; /* need not be kept over crReturn */
4570 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4573 crWaitUntil(!pktin);
4574 ret = get_userpass_input(s->cur_prompt, in, inlen);
4579 * Failed to get a password (for example
4580 * because one was supplied on the command line
4581 * which has already failed to work). Terminate.
4583 free_prompts(s->cur_prompt);
4584 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4589 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4591 * Defence against traffic analysis: we send a
4592 * whole bunch of packets containing strings of
4593 * different lengths. One of these strings is the
4594 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4595 * The others are all random data in
4596 * SSH1_MSG_IGNORE packets. This way a passive
4597 * listener can't tell which is the password, and
4598 * hence can't deduce the password length.
4600 * Anybody with a password length greater than 16
4601 * bytes is going to have enough entropy in their
4602 * password that a listener won't find it _that_
4603 * much help to know how long it is. So what we'll
4606 * - if password length < 16, we send 15 packets
4607 * containing string lengths 1 through 15
4609 * - otherwise, we let N be the nearest multiple
4610 * of 8 below the password length, and send 8
4611 * packets containing string lengths N through
4612 * N+7. This won't obscure the order of
4613 * magnitude of the password length, but it will
4614 * introduce a bit of extra uncertainty.
4616 * A few servers can't deal with SSH1_MSG_IGNORE, at
4617 * least in this context. For these servers, we need
4618 * an alternative defence. We make use of the fact
4619 * that the password is interpreted as a C string:
4620 * so we can append a NUL, then some random data.
4622 * A few servers can deal with neither SSH1_MSG_IGNORE
4623 * here _nor_ a padded password string.
4624 * For these servers we are left with no defences
4625 * against password length sniffing.
4627 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4628 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4630 * The server can deal with SSH1_MSG_IGNORE, so
4631 * we can use the primary defence.
4633 int bottom, top, pwlen, i;
4636 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4638 bottom = 0; /* zero length passwords are OK! :-) */
4641 bottom = pwlen & ~7;
4645 assert(pwlen >= bottom && pwlen <= top);
4647 randomstr = snewn(top + 1, char);
4649 for (i = bottom; i <= top; i++) {
4651 defer_packet(ssh, s->pwpkt_type,
4652 PKT_STR,s->cur_prompt->prompts[0]->result,
4655 for (j = 0; j < i; j++) {
4657 randomstr[j] = random_byte();
4658 } while (randomstr[j] == '\0');
4660 randomstr[i] = '\0';
4661 defer_packet(ssh, SSH1_MSG_IGNORE,
4662 PKT_STR, randomstr, PKT_END);
4665 logevent("Sending password with camouflage packets");
4666 ssh_pkt_defersend(ssh);
4669 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4671 * The server can't deal with SSH1_MSG_IGNORE
4672 * but can deal with padded passwords, so we
4673 * can use the secondary defence.
4679 len = strlen(s->cur_prompt->prompts[0]->result);
4680 if (len < sizeof(string)) {
4682 strcpy(string, s->cur_prompt->prompts[0]->result);
4683 len++; /* cover the zero byte */
4684 while (len < sizeof(string)) {
4685 string[len++] = (char) random_byte();
4688 ss = s->cur_prompt->prompts[0]->result;
4690 logevent("Sending length-padded password");
4691 send_packet(ssh, s->pwpkt_type,
4692 PKT_INT, len, PKT_DATA, ss, len,
4696 * The server is believed unable to cope with
4697 * any of our password camouflage methods.
4700 len = strlen(s->cur_prompt->prompts[0]->result);
4701 logevent("Sending unpadded password");
4702 send_packet(ssh, s->pwpkt_type,
4704 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4708 send_packet(ssh, s->pwpkt_type,
4709 PKT_STR, s->cur_prompt->prompts[0]->result,
4712 logevent("Sent password");
4713 free_prompts(s->cur_prompt);
4715 if (pktin->type == SSH1_SMSG_FAILURE) {
4716 if (flags & FLAG_VERBOSE)
4717 c_write_str(ssh, "Access denied\r\n");
4718 logevent("Authentication refused");
4719 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4720 bombout(("Strange packet received, type %d", pktin->type));
4726 if (s->publickey_blob) {
4727 sfree(s->publickey_blob);
4728 sfree(s->publickey_comment);
4731 logevent("Authentication successful");
4736 static void ssh_channel_try_eof(struct ssh_channel *c)
4739 assert(c->pending_eof); /* precondition for calling us */
4741 return; /* can't close: not even opened yet */
4742 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4743 return; /* can't send EOF: pending outgoing data */
4745 c->pending_eof = FALSE; /* we're about to send it */
4746 if (ssh->version == 1) {
4747 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4749 c->closes |= CLOSES_SENT_EOF;
4751 struct Packet *pktout;
4752 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4753 ssh2_pkt_adduint32(pktout, c->remoteid);
4754 ssh2_pkt_send(ssh, pktout);
4755 c->closes |= CLOSES_SENT_EOF;
4756 ssh2_channel_check_close(c);
4760 Conf *sshfwd_get_conf(struct ssh_channel *c)
4766 void sshfwd_write_eof(struct ssh_channel *c)
4770 if (ssh->state == SSH_STATE_CLOSED)
4773 if (c->closes & CLOSES_SENT_EOF)
4776 c->pending_eof = TRUE;
4777 ssh_channel_try_eof(c);
4780 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4784 if (ssh->state == SSH_STATE_CLOSED)
4789 x11_close(c->u.x11.xconn);
4790 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4794 case CHAN_SOCKDATA_DORMANT:
4795 pfd_close(c->u.pfd.pf);
4796 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4799 c->type = CHAN_ZOMBIE;
4800 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4802 ssh2_channel_check_close(c);
4805 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4809 if (ssh->state == SSH_STATE_CLOSED)
4812 if (ssh->version == 1) {
4813 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4814 PKT_INT, c->remoteid,
4815 PKT_INT, len, PKT_DATA, buf, len,
4818 * In SSH-1 we can return 0 here - implying that forwarded
4819 * connections are never individually throttled - because
4820 * the only circumstance that can cause throttling will be
4821 * the whole SSH connection backing up, in which case
4822 * _everything_ will be throttled as a whole.
4826 ssh2_add_channel_data(c, buf, len);
4827 return ssh2_try_send(c);
4831 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4836 if (ssh->state == SSH_STATE_CLOSED)
4839 if (ssh->version == 1) {
4840 buflimit = SSH1_BUFFER_LIMIT;
4842 buflimit = c->v.v2.locmaxwin;
4843 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4845 if (c->throttling_conn && bufsize <= buflimit) {
4846 c->throttling_conn = 0;
4847 ssh_throttle_conn(ssh, -1);
4851 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4853 struct queued_handler *qh = ssh->qhead;
4857 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4860 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4861 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4864 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4865 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4869 ssh->qhead = qh->next;
4871 if (ssh->qhead->msg1 > 0) {
4872 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4873 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4875 if (ssh->qhead->msg2 > 0) {
4876 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4877 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4880 ssh->qhead = ssh->qtail = NULL;
4883 qh->handler(ssh, pktin, qh->ctx);
4888 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4889 chandler_fn_t handler, void *ctx)
4891 struct queued_handler *qh;
4893 qh = snew(struct queued_handler);
4896 qh->handler = handler;
4900 if (ssh->qtail == NULL) {
4904 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4905 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4908 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4909 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4912 ssh->qtail->next = qh;
4917 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4919 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4921 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4922 SSH2_MSG_REQUEST_SUCCESS)) {
4923 logeventf(ssh, "Remote port forwarding from %s enabled",
4926 logeventf(ssh, "Remote port forwarding from %s refused",
4929 rpf = del234(ssh->rportfwds, pf);
4931 pf->pfrec->remote = NULL;
4936 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4939 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4942 pf->share_ctx = share_ctx;
4943 pf->shost = dupstr(shost);
4945 pf->sportdesc = NULL;
4946 if (!ssh->rportfwds) {
4947 assert(ssh->version == 2);
4948 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4950 if (add234(ssh->rportfwds, pf) != pf) {
4958 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4961 share_got_pkt_from_server(ctx, pktin->type,
4962 pktin->body, pktin->length);
4965 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4967 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4968 ssh_sharing_global_request_response, share_ctx);
4971 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4973 struct ssh_portfwd *epf;
4977 if (!ssh->portfwds) {
4978 ssh->portfwds = newtree234(ssh_portcmp);
4981 * Go through the existing port forwardings and tag them
4982 * with status==DESTROY. Any that we want to keep will be
4983 * re-enabled (status==KEEP) as we go through the
4984 * configuration and find out which bits are the same as
4987 struct ssh_portfwd *epf;
4989 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4990 epf->status = DESTROY;
4993 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4995 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4996 char *kp, *kp2, *vp, *vp2;
4997 char address_family, type;
4998 int sport,dport,sserv,dserv;
4999 char *sports, *dports, *saddr, *host;
5003 address_family = 'A';
5005 if (*kp == 'A' || *kp == '4' || *kp == '6')
5006 address_family = *kp++;
5007 if (*kp == 'L' || *kp == 'R')
5010 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5012 * There's a colon in the middle of the source port
5013 * string, which means that the part before it is
5014 * actually a source address.
5016 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5017 saddr = host_strduptrim(saddr_tmp);
5024 sport = atoi(sports);
5028 sport = net_service_lookup(sports);
5030 logeventf(ssh, "Service lookup failed for source"
5031 " port \"%s\"", sports);
5035 if (type == 'L' && !strcmp(val, "D")) {
5036 /* dynamic forwarding */
5043 /* ordinary forwarding */
5045 vp2 = vp + host_strcspn(vp, ":");
5046 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5050 dport = atoi(dports);
5054 dport = net_service_lookup(dports);
5056 logeventf(ssh, "Service lookup failed for destination"
5057 " port \"%s\"", dports);
5062 if (sport && dport) {
5063 /* Set up a description of the source port. */
5064 struct ssh_portfwd *pfrec, *epfrec;
5066 pfrec = snew(struct ssh_portfwd);
5068 pfrec->saddr = saddr;
5069 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5070 pfrec->sport = sport;
5071 pfrec->daddr = host;
5072 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5073 pfrec->dport = dport;
5074 pfrec->local = NULL;
5075 pfrec->remote = NULL;
5076 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5077 address_family == '6' ? ADDRTYPE_IPV6 :
5080 epfrec = add234(ssh->portfwds, pfrec);
5081 if (epfrec != pfrec) {
5082 if (epfrec->status == DESTROY) {
5084 * We already have a port forwarding up and running
5085 * with precisely these parameters. Hence, no need
5086 * to do anything; simply re-tag the existing one
5089 epfrec->status = KEEP;
5092 * Anything else indicates that there was a duplicate
5093 * in our input, which we'll silently ignore.
5095 free_portfwd(pfrec);
5097 pfrec->status = CREATE;
5106 * Now go through and destroy any port forwardings which were
5109 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5110 if (epf->status == DESTROY) {
5113 message = dupprintf("%s port forwarding from %s%s%d",
5114 epf->type == 'L' ? "local" :
5115 epf->type == 'R' ? "remote" : "dynamic",
5116 epf->saddr ? epf->saddr : "",
5117 epf->saddr ? ":" : "",
5120 if (epf->type != 'D') {
5121 char *msg2 = dupprintf("%s to %s:%d", message,
5122 epf->daddr, epf->dport);
5127 logeventf(ssh, "Cancelling %s", message);
5130 /* epf->remote or epf->local may be NULL if setting up a
5131 * forwarding failed. */
5133 struct ssh_rportfwd *rpf = epf->remote;
5134 struct Packet *pktout;
5137 * Cancel the port forwarding at the server
5140 if (ssh->version == 1) {
5142 * We cannot cancel listening ports on the
5143 * server side in SSH-1! There's no message
5144 * to support it. Instead, we simply remove
5145 * the rportfwd record from the local end
5146 * so that any connections the server tries
5147 * to make on it are rejected.
5150 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5151 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5152 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5154 ssh2_pkt_addstring(pktout, epf->saddr);
5155 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5156 /* XXX: rport_acceptall may not represent
5157 * what was used to open the original connection,
5158 * since it's reconfigurable. */
5159 ssh2_pkt_addstring(pktout, "");
5161 ssh2_pkt_addstring(pktout, "localhost");
5163 ssh2_pkt_adduint32(pktout, epf->sport);
5164 ssh2_pkt_send(ssh, pktout);
5167 del234(ssh->rportfwds, rpf);
5169 } else if (epf->local) {
5170 pfl_terminate(epf->local);
5173 delpos234(ssh->portfwds, i);
5175 i--; /* so we don't skip one in the list */
5179 * And finally, set up any new port forwardings (status==CREATE).
5181 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5182 if (epf->status == CREATE) {
5183 char *sportdesc, *dportdesc;
5184 sportdesc = dupprintf("%s%s%s%s%d%s",
5185 epf->saddr ? epf->saddr : "",
5186 epf->saddr ? ":" : "",
5187 epf->sserv ? epf->sserv : "",
5188 epf->sserv ? "(" : "",
5190 epf->sserv ? ")" : "");
5191 if (epf->type == 'D') {
5194 dportdesc = dupprintf("%s:%s%s%d%s",
5196 epf->dserv ? epf->dserv : "",
5197 epf->dserv ? "(" : "",
5199 epf->dserv ? ")" : "");
5202 if (epf->type == 'L') {
5203 char *err = pfl_listen(epf->daddr, epf->dport,
5204 epf->saddr, epf->sport,
5205 ssh, conf, &epf->local,
5206 epf->addressfamily);
5208 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5209 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5210 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5211 sportdesc, dportdesc,
5212 err ? " failed: " : "", err ? err : "");
5215 } else if (epf->type == 'D') {
5216 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5217 ssh, conf, &epf->local,
5218 epf->addressfamily);
5220 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5221 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5222 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5224 err ? " failed: " : "", err ? err : "");
5229 struct ssh_rportfwd *pf;
5232 * Ensure the remote port forwardings tree exists.
5234 if (!ssh->rportfwds) {
5235 if (ssh->version == 1)
5236 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5238 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5241 pf = snew(struct ssh_rportfwd);
5242 pf->share_ctx = NULL;
5243 pf->dhost = dupstr(epf->daddr);
5244 pf->dport = epf->dport;
5246 pf->shost = dupstr(epf->saddr);
5247 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5248 pf->shost = dupstr("");
5250 pf->shost = dupstr("localhost");
5252 pf->sport = epf->sport;
5253 if (add234(ssh->rportfwds, pf) != pf) {
5254 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5255 epf->daddr, epf->dport);
5258 logeventf(ssh, "Requesting remote port %s"
5259 " forward to %s", sportdesc, dportdesc);
5261 pf->sportdesc = sportdesc;
5266 if (ssh->version == 1) {
5267 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5268 PKT_INT, epf->sport,
5269 PKT_STR, epf->daddr,
5270 PKT_INT, epf->dport,
5272 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5274 ssh_rportfwd_succfail, pf);
5276 struct Packet *pktout;
5277 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5278 ssh2_pkt_addstring(pktout, "tcpip-forward");
5279 ssh2_pkt_addbool(pktout, 1);/* want reply */
5280 ssh2_pkt_addstring(pktout, pf->shost);
5281 ssh2_pkt_adduint32(pktout, pf->sport);
5282 ssh2_pkt_send(ssh, pktout);
5284 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5285 SSH2_MSG_REQUEST_FAILURE,
5286 ssh_rportfwd_succfail, pf);
5295 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5298 int stringlen, bufsize;
5300 ssh_pkt_getstring(pktin, &string, &stringlen);
5301 if (string == NULL) {
5302 bombout(("Incoming terminal data packet was badly formed"));
5306 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5308 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5309 ssh->v1_stdout_throttling = 1;
5310 ssh_throttle_conn(ssh, +1);
5314 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5316 /* Remote side is trying to open a channel to talk to our
5317 * X-Server. Give them back a local channel number. */
5318 struct ssh_channel *c;
5319 int remoteid = ssh_pkt_getuint32(pktin);
5321 logevent("Received X11 connect request");
5322 /* Refuse if X11 forwarding is disabled. */
5323 if (!ssh->X11_fwd_enabled) {
5324 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5325 PKT_INT, remoteid, PKT_END);
5326 logevent("Rejected X11 connect request");
5328 c = snew(struct ssh_channel);
5331 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5332 c->remoteid = remoteid;
5333 c->halfopen = FALSE;
5334 c->localid = alloc_channel_id(ssh);
5336 c->pending_eof = FALSE;
5337 c->throttling_conn = 0;
5338 c->type = CHAN_X11; /* identify channel type */
5339 add234(ssh->channels, c);
5340 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5341 PKT_INT, c->remoteid, PKT_INT,
5342 c->localid, PKT_END);
5343 logevent("Opened X11 forward channel");
5347 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5349 /* Remote side is trying to open a channel to talk to our
5350 * agent. Give them back a local channel number. */
5351 struct ssh_channel *c;
5352 int remoteid = ssh_pkt_getuint32(pktin);
5354 /* Refuse if agent forwarding is disabled. */
5355 if (!ssh->agentfwd_enabled) {
5356 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5357 PKT_INT, remoteid, PKT_END);
5359 c = snew(struct ssh_channel);
5361 c->remoteid = remoteid;
5362 c->halfopen = FALSE;
5363 c->localid = alloc_channel_id(ssh);
5365 c->pending_eof = FALSE;
5366 c->throttling_conn = 0;
5367 c->type = CHAN_AGENT; /* identify channel type */
5368 c->u.a.lensofar = 0;
5369 c->u.a.message = NULL;
5370 c->u.a.outstanding_requests = 0;
5371 add234(ssh->channels, c);
5372 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5373 PKT_INT, c->remoteid, PKT_INT, c->localid,
5378 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5380 /* Remote side is trying to open a channel to talk to a
5381 * forwarded port. Give them back a local channel number. */
5382 struct ssh_rportfwd pf, *pfp;
5388 remoteid = ssh_pkt_getuint32(pktin);
5389 ssh_pkt_getstring(pktin, &host, &hostsize);
5390 port = ssh_pkt_getuint32(pktin);
5392 pf.dhost = dupprintf("%.*s", hostsize, host);
5394 pfp = find234(ssh->rportfwds, &pf, NULL);
5397 logeventf(ssh, "Rejected remote port open request for %s:%d",
5399 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5400 PKT_INT, remoteid, PKT_END);
5402 struct ssh_channel *c = snew(struct ssh_channel);
5405 logeventf(ssh, "Received remote port open request for %s:%d",
5407 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5408 c, ssh->conf, pfp->pfrec->addressfamily);
5410 logeventf(ssh, "Port open failed: %s", err);
5413 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5414 PKT_INT, remoteid, PKT_END);
5416 c->remoteid = remoteid;
5417 c->halfopen = FALSE;
5418 c->localid = alloc_channel_id(ssh);
5420 c->pending_eof = FALSE;
5421 c->throttling_conn = 0;
5422 c->type = CHAN_SOCKDATA; /* identify channel type */
5423 add234(ssh->channels, c);
5424 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5425 PKT_INT, c->remoteid, PKT_INT,
5426 c->localid, PKT_END);
5427 logevent("Forwarded port opened successfully");
5434 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5436 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5437 unsigned int localid = ssh_pkt_getuint32(pktin);
5438 struct ssh_channel *c;
5440 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5441 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5442 c->remoteid = localid;
5443 c->halfopen = FALSE;
5444 c->type = CHAN_SOCKDATA;
5445 c->throttling_conn = 0;
5446 pfd_confirm(c->u.pfd.pf);
5449 if (c && c->pending_eof) {
5451 * We have a pending close on this channel,
5452 * which we decided on before the server acked
5453 * the channel open. So now we know the
5454 * remoteid, we can close it again.
5456 ssh_channel_try_eof(c);
5460 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5462 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5463 struct ssh_channel *c;
5465 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5466 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5467 logevent("Forwarded connection refused by server");
5468 pfd_close(c->u.pfd.pf);
5469 del234(ssh->channels, c);
5474 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5476 /* Remote side closes a channel. */
5477 unsigned i = ssh_pkt_getuint32(pktin);
5478 struct ssh_channel *c;
5479 c = find234(ssh->channels, &i, ssh_channelfind);
5480 if (c && !c->halfopen) {
5482 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5483 !(c->closes & CLOSES_RCVD_EOF)) {
5485 * Received CHANNEL_CLOSE, which we translate into
5488 int send_close = FALSE;
5490 c->closes |= CLOSES_RCVD_EOF;
5495 x11_send_eof(c->u.x11.xconn);
5501 pfd_send_eof(c->u.pfd.pf);
5510 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5511 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5513 c->closes |= CLOSES_SENT_EOF;
5517 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5518 !(c->closes & CLOSES_RCVD_CLOSE)) {
5520 if (!(c->closes & CLOSES_SENT_EOF)) {
5521 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5522 " for which we never sent CHANNEL_CLOSE\n", i));
5525 c->closes |= CLOSES_RCVD_CLOSE;
5528 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5529 !(c->closes & CLOSES_SENT_CLOSE)) {
5530 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5531 PKT_INT, c->remoteid, PKT_END);
5532 c->closes |= CLOSES_SENT_CLOSE;
5535 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5536 ssh_channel_destroy(c);
5538 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5539 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5540 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5545 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5547 /* Data sent down one of our channels. */
5548 int i = ssh_pkt_getuint32(pktin);
5551 struct ssh_channel *c;
5553 ssh_pkt_getstring(pktin, &p, &len);
5555 c = find234(ssh->channels, &i, ssh_channelfind);
5560 bufsize = x11_send(c->u.x11.xconn, p, len);
5563 bufsize = pfd_send(c->u.pfd.pf, p, len);
5566 /* Data for an agent message. Buffer it. */
5568 if (c->u.a.lensofar < 4) {
5569 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5570 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5574 c->u.a.lensofar += l;
5576 if (c->u.a.lensofar == 4) {
5578 4 + GET_32BIT(c->u.a.msglen);
5579 c->u.a.message = snewn(c->u.a.totallen,
5581 memcpy(c->u.a.message, c->u.a.msglen, 4);
5583 if (c->u.a.lensofar >= 4 && len > 0) {
5585 min(c->u.a.totallen - c->u.a.lensofar,
5587 memcpy(c->u.a.message + c->u.a.lensofar, p,
5591 c->u.a.lensofar += l;
5593 if (c->u.a.lensofar == c->u.a.totallen) {
5596 c->u.a.outstanding_requests++;
5597 if (agent_query(c->u.a.message,
5600 ssh_agentf_callback, c))
5601 ssh_agentf_callback(c, reply, replylen);
5602 sfree(c->u.a.message);
5603 c->u.a.lensofar = 0;
5606 bufsize = 0; /* agent channels never back up */
5609 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5610 c->throttling_conn = 1;
5611 ssh_throttle_conn(ssh, +1);
5616 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5618 ssh->exitcode = ssh_pkt_getuint32(pktin);
5619 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5620 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5622 * In case `helpful' firewalls or proxies tack
5623 * extra human-readable text on the end of the
5624 * session which we might mistake for another
5625 * encrypted packet, we close the session once
5626 * we've sent EXIT_CONFIRMATION.
5628 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5631 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5632 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5634 struct Packet *pktout = (struct Packet *)data;
5636 unsigned int arg = 0;
5637 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5638 if (i == lenof(ssh_ttymodes)) return;
5639 switch (ssh_ttymodes[i].type) {
5641 arg = ssh_tty_parse_specchar(val);
5644 arg = ssh_tty_parse_boolean(val);
5647 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5648 ssh2_pkt_addbyte(pktout, arg);
5651 int ssh_agent_forwarding_permitted(Ssh ssh)
5653 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5656 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5657 struct Packet *pktin)
5659 crBegin(ssh->do_ssh1_connection_crstate);
5661 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5662 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5663 ssh1_smsg_stdout_stderr_data;
5665 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5666 ssh1_msg_channel_open_confirmation;
5667 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5668 ssh1_msg_channel_open_failure;
5669 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5670 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5671 ssh1_msg_channel_close;
5672 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5673 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5675 if (ssh_agent_forwarding_permitted(ssh)) {
5676 logevent("Requesting agent forwarding");
5677 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5681 if (pktin->type != SSH1_SMSG_SUCCESS
5682 && pktin->type != SSH1_SMSG_FAILURE) {
5683 bombout(("Protocol confusion"));
5685 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5686 logevent("Agent forwarding refused");
5688 logevent("Agent forwarding enabled");
5689 ssh->agentfwd_enabled = TRUE;
5690 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5694 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5696 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5698 if (!ssh->x11disp) {
5699 /* FIXME: return an error message from x11_setup_display */
5700 logevent("X11 forwarding not enabled: unable to"
5701 " initialise X display");
5703 ssh->x11auth = x11_invent_fake_auth
5704 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5705 ssh->x11auth->disp = ssh->x11disp;
5707 logevent("Requesting X11 forwarding");
5708 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5709 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5710 PKT_STR, ssh->x11auth->protoname,
5711 PKT_STR, ssh->x11auth->datastring,
5712 PKT_INT, ssh->x11disp->screennum,
5715 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5716 PKT_STR, ssh->x11auth->protoname,
5717 PKT_STR, ssh->x11auth->datastring,
5723 if (pktin->type != SSH1_SMSG_SUCCESS
5724 && pktin->type != SSH1_SMSG_FAILURE) {
5725 bombout(("Protocol confusion"));
5727 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5728 logevent("X11 forwarding refused");
5730 logevent("X11 forwarding enabled");
5731 ssh->X11_fwd_enabled = TRUE;
5732 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5737 ssh_setup_portfwd(ssh, ssh->conf);
5738 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5740 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5742 /* Unpick the terminal-speed string. */
5743 /* XXX perhaps we should allow no speeds to be sent. */
5744 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5745 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5746 /* Send the pty request. */
5747 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5748 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5749 ssh_pkt_adduint32(pkt, ssh->term_height);
5750 ssh_pkt_adduint32(pkt, ssh->term_width);
5751 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5752 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5753 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5754 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5755 ssh_pkt_adduint32(pkt, ssh->ispeed);
5756 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5757 ssh_pkt_adduint32(pkt, ssh->ospeed);
5758 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5760 ssh->state = SSH_STATE_INTERMED;
5764 if (pktin->type != SSH1_SMSG_SUCCESS
5765 && pktin->type != SSH1_SMSG_FAILURE) {
5766 bombout(("Protocol confusion"));
5768 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5769 c_write_str(ssh, "Server refused to allocate pty\r\n");
5770 ssh->editing = ssh->echoing = 1;
5772 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5773 ssh->ospeed, ssh->ispeed);
5774 ssh->got_pty = TRUE;
5777 ssh->editing = ssh->echoing = 1;
5780 if (conf_get_int(ssh->conf, CONF_compression)) {
5781 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5785 if (pktin->type != SSH1_SMSG_SUCCESS
5786 && pktin->type != SSH1_SMSG_FAILURE) {
5787 bombout(("Protocol confusion"));
5789 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5790 c_write_str(ssh, "Server refused to compress\r\n");
5792 logevent("Started compression");
5793 ssh->v1_compressing = TRUE;
5794 ssh->cs_comp_ctx = zlib_compress_init();
5795 logevent("Initialised zlib (RFC1950) compression");
5796 ssh->sc_comp_ctx = zlib_decompress_init();
5797 logevent("Initialised zlib (RFC1950) decompression");
5801 * Start the shell or command.
5803 * Special case: if the first-choice command is an SSH-2
5804 * subsystem (hence not usable here) and the second choice
5805 * exists, we fall straight back to that.
5808 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5810 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5811 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5812 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5813 ssh->fallback_cmd = TRUE;
5816 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5818 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5819 logevent("Started session");
5822 ssh->state = SSH_STATE_SESSION;
5823 if (ssh->size_needed)
5824 ssh_size(ssh, ssh->term_width, ssh->term_height);
5825 if (ssh->eof_needed)
5826 ssh_special(ssh, TS_EOF);
5829 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5831 ssh->channels = newtree234(ssh_channelcmp);
5835 * By this point, most incoming packets are already being
5836 * handled by the dispatch table, and we need only pay
5837 * attention to the unusual ones.
5842 if (pktin->type == SSH1_SMSG_SUCCESS) {
5843 /* may be from EXEC_SHELL on some servers */
5844 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5845 /* may be from EXEC_SHELL on some servers
5846 * if no pty is available or in other odd cases. Ignore */
5848 bombout(("Strange packet received: type %d", pktin->type));
5853 int len = min(inlen, 512);
5854 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5855 PKT_INT, len, PKT_DATA, in, len,
5867 * Handle the top-level SSH-2 protocol.
5869 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5874 ssh_pkt_getstring(pktin, &msg, &msglen);
5875 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5878 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5880 /* log reason code in disconnect message */
5884 ssh_pkt_getstring(pktin, &msg, &msglen);
5885 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5888 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5890 /* Do nothing, because we're ignoring it! Duhh. */
5893 static void ssh1_protocol_setup(Ssh ssh)
5898 * Most messages are handled by the coroutines.
5900 for (i = 0; i < 256; i++)
5901 ssh->packet_dispatch[i] = NULL;
5904 * These special message types we install handlers for.
5906 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5907 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5908 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5911 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5912 struct Packet *pktin)
5914 unsigned char *in=(unsigned char*)vin;
5915 if (ssh->state == SSH_STATE_CLOSED)
5918 if (pktin && ssh->packet_dispatch[pktin->type]) {
5919 ssh->packet_dispatch[pktin->type](ssh, pktin);
5923 if (!ssh->protocol_initial_phase_done) {
5924 if (do_ssh1_login(ssh, in, inlen, pktin))
5925 ssh->protocol_initial_phase_done = TRUE;
5930 do_ssh1_connection(ssh, in, inlen, pktin);
5934 * Utility routine for decoding comma-separated strings in KEXINIT.
5936 static int in_commasep_string(char *needle, char *haystack, int haylen)
5939 if (!needle || !haystack) /* protect against null pointers */
5941 needlen = strlen(needle);
5944 * Is it at the start of the string?
5946 if (haylen >= needlen && /* haystack is long enough */
5947 !memcmp(needle, haystack, needlen) && /* initial match */
5948 (haylen == needlen || haystack[needlen] == ',')
5949 /* either , or EOS follows */
5953 * If not, search for the next comma and resume after that.
5954 * If no comma found, terminate.
5956 while (haylen > 0 && *haystack != ',')
5957 haylen--, haystack++;
5960 haylen--, haystack++; /* skip over comma itself */
5965 * Similar routine for checking whether we have the first string in a list.
5967 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5970 if (!needle || !haystack) /* protect against null pointers */
5972 needlen = strlen(needle);
5974 * Is it at the start of the string?
5976 if (haylen >= needlen && /* haystack is long enough */
5977 !memcmp(needle, haystack, needlen) && /* initial match */
5978 (haylen == needlen || haystack[needlen] == ',')
5979 /* either , or EOS follows */
5987 * SSH-2 key creation method.
5988 * (Currently assumes 2 lots of any hash are sufficient to generate
5989 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5991 #define SSH2_MKKEY_ITERS (2)
5992 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5993 unsigned char *keyspace)
5995 const struct ssh_hash *h = ssh->kex->hash;
5997 /* First hlen bytes. */
5999 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6000 hash_mpint(h, s, K);
6001 h->bytes(s, H, h->hlen);
6002 h->bytes(s, &chr, 1);
6003 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6004 h->final(s, keyspace);
6005 /* Next hlen bytes. */
6007 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6008 hash_mpint(h, s, K);
6009 h->bytes(s, H, h->hlen);
6010 h->bytes(s, keyspace, h->hlen);
6011 h->final(s, keyspace + h->hlen);
6015 * Handle the SSH-2 transport layer.
6017 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6018 struct Packet *pktin)
6020 unsigned char *in = (unsigned char *)vin;
6021 struct do_ssh2_transport_state {
6023 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6024 Bignum p, g, e, f, K;
6027 int kex_init_value, kex_reply_value;
6028 const struct ssh_mac **maclist;
6030 const struct ssh2_cipher *cscipher_tobe;
6031 const struct ssh2_cipher *sccipher_tobe;
6032 const struct ssh_mac *csmac_tobe;
6033 const struct ssh_mac *scmac_tobe;
6034 const struct ssh_compress *cscomp_tobe;
6035 const struct ssh_compress *sccomp_tobe;
6036 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6037 int hostkeylen, siglen, rsakeylen;
6038 void *hkey; /* actual host key */
6039 void *rsakey; /* for RSA kex */
6040 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6041 int n_preferred_kex;
6042 const struct ssh_kexes *preferred_kex[KEX_MAX];
6043 int n_preferred_ciphers;
6044 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6045 const struct ssh_compress *preferred_comp;
6046 int userauth_succeeded; /* for delayed compression */
6047 int pending_compression;
6048 int got_session_id, activated_authconn;
6049 struct Packet *pktout;
6054 crState(do_ssh2_transport_state);
6056 assert(!ssh->bare_connection);
6060 s->cscipher_tobe = s->sccipher_tobe = NULL;
6061 s->csmac_tobe = s->scmac_tobe = NULL;
6062 s->cscomp_tobe = s->sccomp_tobe = NULL;
6064 s->got_session_id = s->activated_authconn = FALSE;
6065 s->userauth_succeeded = FALSE;
6066 s->pending_compression = FALSE;
6069 * Be prepared to work around the buggy MAC problem.
6071 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6072 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6074 s->maclist = macs, s->nmacs = lenof(macs);
6077 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6079 int i, j, k, commalist_started;
6082 * Set up the preferred key exchange. (NULL => warn below here)
6084 s->n_preferred_kex = 0;
6085 for (i = 0; i < KEX_MAX; i++) {
6086 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6088 s->preferred_kex[s->n_preferred_kex++] =
6089 &ssh_diffiehellman_gex;
6092 s->preferred_kex[s->n_preferred_kex++] =
6093 &ssh_diffiehellman_group14;
6096 s->preferred_kex[s->n_preferred_kex++] =
6097 &ssh_diffiehellman_group1;
6100 s->preferred_kex[s->n_preferred_kex++] =
6104 /* Flag for later. Don't bother if it's the last in
6106 if (i < KEX_MAX - 1) {
6107 s->preferred_kex[s->n_preferred_kex++] = NULL;
6114 * Set up the preferred ciphers. (NULL => warn below here)
6116 s->n_preferred_ciphers = 0;
6117 for (i = 0; i < CIPHER_MAX; i++) {
6118 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6119 case CIPHER_BLOWFISH:
6120 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6123 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6124 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6128 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6131 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6133 case CIPHER_ARCFOUR:
6134 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6137 /* Flag for later. Don't bother if it's the last in
6139 if (i < CIPHER_MAX - 1) {
6140 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6147 * Set up preferred compression.
6149 if (conf_get_int(ssh->conf, CONF_compression))
6150 s->preferred_comp = &ssh_zlib;
6152 s->preferred_comp = &ssh_comp_none;
6155 * Enable queueing of outgoing auth- or connection-layer
6156 * packets while we are in the middle of a key exchange.
6158 ssh->queueing = TRUE;
6161 * Flag that KEX is in progress.
6163 ssh->kex_in_progress = TRUE;
6166 * Construct and send our key exchange packet.
6168 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6169 for (i = 0; i < 16; i++)
6170 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6171 /* List key exchange algorithms. */
6172 ssh2_pkt_addstring_start(s->pktout);
6173 commalist_started = 0;
6174 for (i = 0; i < s->n_preferred_kex; i++) {
6175 const struct ssh_kexes *k = s->preferred_kex[i];
6176 if (!k) continue; /* warning flag */
6177 for (j = 0; j < k->nkexes; j++) {
6178 if (commalist_started)
6179 ssh2_pkt_addstring_str(s->pktout, ",");
6180 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6181 commalist_started = 1;
6184 /* List server host key algorithms. */
6185 if (!s->got_session_id) {
6187 * In the first key exchange, we list all the algorithms
6188 * we're prepared to cope with.
6190 ssh2_pkt_addstring_start(s->pktout);
6191 for (i = 0; i < lenof(hostkey_algs); i++) {
6192 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6193 if (i < lenof(hostkey_algs) - 1)
6194 ssh2_pkt_addstring_str(s->pktout, ",");
6198 * In subsequent key exchanges, we list only the kex
6199 * algorithm that was selected in the first key exchange,
6200 * so that we keep getting the same host key and hence
6201 * don't have to interrupt the user's session to ask for
6205 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6207 /* List encryption algorithms (client->server then server->client). */
6208 for (k = 0; k < 2; k++) {
6209 ssh2_pkt_addstring_start(s->pktout);
6210 commalist_started = 0;
6211 for (i = 0; i < s->n_preferred_ciphers; i++) {
6212 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6213 if (!c) continue; /* warning flag */
6214 for (j = 0; j < c->nciphers; j++) {
6215 if (commalist_started)
6216 ssh2_pkt_addstring_str(s->pktout, ",");
6217 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6218 commalist_started = 1;
6222 /* List MAC algorithms (client->server then server->client). */
6223 for (j = 0; j < 2; j++) {
6224 ssh2_pkt_addstring_start(s->pktout);
6225 for (i = 0; i < s->nmacs; i++) {
6226 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6227 if (i < s->nmacs - 1)
6228 ssh2_pkt_addstring_str(s->pktout, ",");
6231 /* List client->server compression algorithms,
6232 * then server->client compression algorithms. (We use the
6233 * same set twice.) */
6234 for (j = 0; j < 2; j++) {
6235 ssh2_pkt_addstring_start(s->pktout);
6236 assert(lenof(compressions) > 1);
6237 /* Prefer non-delayed versions */
6238 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6239 /* We don't even list delayed versions of algorithms until
6240 * they're allowed to be used, to avoid a race. See the end of
6242 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6243 ssh2_pkt_addstring_str(s->pktout, ",");
6244 ssh2_pkt_addstring_str(s->pktout,
6245 s->preferred_comp->delayed_name);
6247 for (i = 0; i < lenof(compressions); i++) {
6248 const struct ssh_compress *c = compressions[i];
6249 if (c != s->preferred_comp) {
6250 ssh2_pkt_addstring_str(s->pktout, ",");
6251 ssh2_pkt_addstring_str(s->pktout, c->name);
6252 if (s->userauth_succeeded && c->delayed_name) {
6253 ssh2_pkt_addstring_str(s->pktout, ",");
6254 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6259 /* List client->server languages. Empty list. */
6260 ssh2_pkt_addstring_start(s->pktout);
6261 /* List server->client languages. Empty list. */
6262 ssh2_pkt_addstring_start(s->pktout);
6263 /* First KEX packet does _not_ follow, because we're not that brave. */
6264 ssh2_pkt_addbool(s->pktout, FALSE);
6266 ssh2_pkt_adduint32(s->pktout, 0);
6269 s->our_kexinitlen = s->pktout->length - 5;
6270 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6271 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6273 ssh2_pkt_send_noqueue(ssh, s->pktout);
6276 crWaitUntilV(pktin);
6279 * Now examine the other side's KEXINIT to see what we're up
6283 char *str, *preferred;
6286 if (pktin->type != SSH2_MSG_KEXINIT) {
6287 bombout(("expected key exchange packet from server"));
6291 ssh->hostkey = NULL;
6292 s->cscipher_tobe = NULL;
6293 s->sccipher_tobe = NULL;
6294 s->csmac_tobe = NULL;
6295 s->scmac_tobe = NULL;
6296 s->cscomp_tobe = NULL;
6297 s->sccomp_tobe = NULL;
6298 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6300 pktin->savedpos += 16; /* skip garbage cookie */
6301 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6303 bombout(("KEXINIT packet was incomplete"));
6308 for (i = 0; i < s->n_preferred_kex; i++) {
6309 const struct ssh_kexes *k = s->preferred_kex[i];
6313 for (j = 0; j < k->nkexes; j++) {
6314 if (!preferred) preferred = k->list[j]->name;
6315 if (in_commasep_string(k->list[j]->name, str, len)) {
6316 ssh->kex = k->list[j];
6325 bombout(("Couldn't agree a key exchange algorithm"
6326 " (available: %.*s)", len, str));
6330 * Note that the server's guess is considered wrong if it doesn't match
6331 * the first algorithm in our list, even if it's still the algorithm
6334 s->guessok = first_in_commasep_string(preferred, str, len);
6335 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6337 bombout(("KEXINIT packet was incomplete"));
6340 for (i = 0; i < lenof(hostkey_algs); i++) {
6341 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6342 ssh->hostkey = hostkey_algs[i];
6346 if (!ssh->hostkey) {
6347 bombout(("Couldn't agree a host key algorithm"
6348 " (available: %.*s)", len, str));
6352 s->guessok = s->guessok &&
6353 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6354 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6356 bombout(("KEXINIT packet was incomplete"));
6359 for (i = 0; i < s->n_preferred_ciphers; i++) {
6360 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6362 s->warn_cscipher = TRUE;
6364 for (j = 0; j < c->nciphers; j++) {
6365 if (in_commasep_string(c->list[j]->name, str, len)) {
6366 s->cscipher_tobe = c->list[j];
6371 if (s->cscipher_tobe)
6374 if (!s->cscipher_tobe) {
6375 bombout(("Couldn't agree a client-to-server cipher"
6376 " (available: %.*s)", len, str));
6380 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6382 bombout(("KEXINIT packet was incomplete"));
6385 for (i = 0; i < s->n_preferred_ciphers; i++) {
6386 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6388 s->warn_sccipher = TRUE;
6390 for (j = 0; j < c->nciphers; j++) {
6391 if (in_commasep_string(c->list[j]->name, str, len)) {
6392 s->sccipher_tobe = c->list[j];
6397 if (s->sccipher_tobe)
6400 if (!s->sccipher_tobe) {
6401 bombout(("Couldn't agree a server-to-client cipher"
6402 " (available: %.*s)", len, str));
6406 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6408 bombout(("KEXINIT packet was incomplete"));
6411 for (i = 0; i < s->nmacs; i++) {
6412 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6413 s->csmac_tobe = s->maclist[i];
6417 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6419 bombout(("KEXINIT packet was incomplete"));
6422 for (i = 0; i < s->nmacs; i++) {
6423 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6424 s->scmac_tobe = s->maclist[i];
6428 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6430 bombout(("KEXINIT packet was incomplete"));
6433 for (i = 0; i < lenof(compressions) + 1; i++) {
6434 const struct ssh_compress *c =
6435 i == 0 ? s->preferred_comp : compressions[i - 1];
6436 if (in_commasep_string(c->name, str, len)) {
6439 } else if (in_commasep_string(c->delayed_name, str, len)) {
6440 if (s->userauth_succeeded) {
6444 s->pending_compression = TRUE; /* try this later */
6448 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6450 bombout(("KEXINIT packet was incomplete"));
6453 for (i = 0; i < lenof(compressions) + 1; i++) {
6454 const struct ssh_compress *c =
6455 i == 0 ? s->preferred_comp : compressions[i - 1];
6456 if (in_commasep_string(c->name, str, len)) {
6459 } else if (in_commasep_string(c->delayed_name, str, len)) {
6460 if (s->userauth_succeeded) {
6464 s->pending_compression = TRUE; /* try this later */
6468 if (s->pending_compression) {
6469 logevent("Server supports delayed compression; "
6470 "will try this later");
6472 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6473 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6474 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6476 ssh->exhash = ssh->kex->hash->init();
6477 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6478 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6479 hash_string(ssh->kex->hash, ssh->exhash,
6480 s->our_kexinit, s->our_kexinitlen);
6481 sfree(s->our_kexinit);
6482 /* Include the type byte in the hash of server's KEXINIT */
6483 hash_string(ssh->kex->hash, ssh->exhash,
6484 pktin->body - 1, pktin->length + 1);
6487 ssh_set_frozen(ssh, 1);
6488 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6490 ssh_dialog_callback, ssh);
6491 if (s->dlgret < 0) {
6495 bombout(("Unexpected data from server while"
6496 " waiting for user response"));
6499 } while (pktin || inlen > 0);
6500 s->dlgret = ssh->user_response;
6502 ssh_set_frozen(ssh, 0);
6503 if (s->dlgret == 0) {
6504 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6510 if (s->warn_cscipher) {
6511 ssh_set_frozen(ssh, 1);
6512 s->dlgret = askalg(ssh->frontend,
6513 "client-to-server cipher",
6514 s->cscipher_tobe->name,
6515 ssh_dialog_callback, ssh);
6516 if (s->dlgret < 0) {
6520 bombout(("Unexpected data from server while"
6521 " waiting for user response"));
6524 } while (pktin || inlen > 0);
6525 s->dlgret = ssh->user_response;
6527 ssh_set_frozen(ssh, 0);
6528 if (s->dlgret == 0) {
6529 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6535 if (s->warn_sccipher) {
6536 ssh_set_frozen(ssh, 1);
6537 s->dlgret = askalg(ssh->frontend,
6538 "server-to-client cipher",
6539 s->sccipher_tobe->name,
6540 ssh_dialog_callback, ssh);
6541 if (s->dlgret < 0) {
6545 bombout(("Unexpected data from server while"
6546 " waiting for user response"));
6549 } while (pktin || inlen > 0);
6550 s->dlgret = ssh->user_response;
6552 ssh_set_frozen(ssh, 0);
6553 if (s->dlgret == 0) {
6554 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6560 if (s->ignorepkt) /* first_kex_packet_follows */
6561 crWaitUntilV(pktin); /* Ignore packet */
6564 if (ssh->kex->main_type == KEXTYPE_DH) {
6566 * Work out the number of bits of key we will need from the
6567 * key exchange. We start with the maximum key length of
6573 csbits = s->cscipher_tobe->keylen;
6574 scbits = s->sccipher_tobe->keylen;
6575 s->nbits = (csbits > scbits ? csbits : scbits);
6577 /* The keys only have hlen-bit entropy, since they're based on
6578 * a hash. So cap the key size at hlen bits. */
6579 if (s->nbits > ssh->kex->hash->hlen * 8)
6580 s->nbits = ssh->kex->hash->hlen * 8;
6583 * If we're doing Diffie-Hellman group exchange, start by
6584 * requesting a group.
6586 if (!ssh->kex->pdata) {
6587 logevent("Doing Diffie-Hellman group exchange");
6588 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6590 * Work out how big a DH group we will need to allow that
6593 s->pbits = 512 << ((s->nbits - 1) / 64);
6594 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6595 ssh2_pkt_adduint32(s->pktout, s->pbits);
6596 ssh2_pkt_send_noqueue(ssh, s->pktout);
6598 crWaitUntilV(pktin);
6599 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6600 bombout(("expected key exchange group packet from server"));
6603 s->p = ssh2_pkt_getmp(pktin);
6604 s->g = ssh2_pkt_getmp(pktin);
6605 if (!s->p || !s->g) {
6606 bombout(("unable to read mp-ints from incoming group packet"));
6609 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6610 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6611 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6613 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6614 ssh->kex_ctx = dh_setup_group(ssh->kex);
6615 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6616 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6617 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6618 ssh->kex->groupname);
6621 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6622 ssh->kex->hash->text_name);
6624 * Now generate and send e for Diffie-Hellman.
6626 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6627 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6628 s->pktout = ssh2_pkt_init(s->kex_init_value);
6629 ssh2_pkt_addmp(s->pktout, s->e);
6630 ssh2_pkt_send_noqueue(ssh, s->pktout);
6632 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6633 crWaitUntilV(pktin);
6634 if (pktin->type != s->kex_reply_value) {
6635 bombout(("expected key exchange reply packet from server"));
6638 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6639 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6640 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6641 s->f = ssh2_pkt_getmp(pktin);
6643 bombout(("unable to parse key exchange reply packet"));
6646 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6648 s->K = dh_find_K(ssh->kex_ctx, s->f);
6650 /* We assume everything from now on will be quick, and it might
6651 * involve user interaction. */
6652 set_busy_status(ssh->frontend, BUSY_NOT);
6654 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6655 if (!ssh->kex->pdata) {
6656 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6657 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6658 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6660 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6661 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6663 dh_cleanup(ssh->kex_ctx);
6665 if (!ssh->kex->pdata) {
6670 logeventf(ssh, "Doing RSA key exchange with hash %s",
6671 ssh->kex->hash->text_name);
6672 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6674 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6677 crWaitUntilV(pktin);
6678 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6679 bombout(("expected RSA public key packet from server"));
6683 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6684 hash_string(ssh->kex->hash, ssh->exhash,
6685 s->hostkeydata, s->hostkeylen);
6686 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6690 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6691 s->rsakeydata = snewn(s->rsakeylen, char);
6692 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6695 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6697 sfree(s->rsakeydata);
6698 bombout(("unable to parse RSA public key from server"));
6702 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6705 * Next, set up a shared secret K, of precisely KLEN -
6706 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6707 * RSA key modulus and HLEN is the bit length of the hash
6711 int klen = ssh_rsakex_klen(s->rsakey);
6712 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6714 unsigned char *kstr1, *kstr2, *outstr;
6715 int kstr1len, kstr2len, outstrlen;
6717 s->K = bn_power_2(nbits - 1);
6719 for (i = 0; i < nbits; i++) {
6721 byte = random_byte();
6723 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6727 * Encode this as an mpint.
6729 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6730 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6731 PUT_32BIT(kstr2, kstr1len);
6732 memcpy(kstr2 + 4, kstr1, kstr1len);
6735 * Encrypt it with the given RSA key.
6737 outstrlen = (klen + 7) / 8;
6738 outstr = snewn(outstrlen, unsigned char);
6739 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6740 outstr, outstrlen, s->rsakey);
6743 * And send it off in a return packet.
6745 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6746 ssh2_pkt_addstring_start(s->pktout);
6747 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6748 ssh2_pkt_send_noqueue(ssh, s->pktout);
6750 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6757 ssh_rsakex_freekey(s->rsakey);
6759 crWaitUntilV(pktin);
6760 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6761 sfree(s->rsakeydata);
6762 bombout(("expected signature packet from server"));
6766 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6768 sfree(s->rsakeydata);
6771 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6772 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6773 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6775 ssh->kex_ctx = NULL;
6778 debug(("Exchange hash is:\n"));
6779 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6783 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6784 (char *)s->exchange_hash,
6785 ssh->kex->hash->hlen)) {
6786 bombout(("Server's host key did not match the signature supplied"));
6790 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6791 if (!s->got_session_id) {
6793 * Authenticate remote host: verify host key. (We've already
6794 * checked the signature of the exchange hash.)
6796 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6797 logevent("Host key fingerprint is:");
6798 logevent(s->fingerprint);
6799 /* First check against manually configured host keys. */
6800 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6801 ssh->hostkey, s->hkey);
6802 if (s->dlgret == 0) { /* did not match */
6803 bombout(("Host key did not appear in manually configured list"));
6805 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6806 ssh_set_frozen(ssh, 1);
6807 s->dlgret = verify_ssh_host_key(ssh->frontend,
6808 ssh->savedhost, ssh->savedport,
6809 ssh->hostkey->keytype, s->keystr,
6811 ssh_dialog_callback, ssh);
6812 if (s->dlgret < 0) {
6816 bombout(("Unexpected data from server while waiting"
6817 " for user host key response"));
6820 } while (pktin || inlen > 0);
6821 s->dlgret = ssh->user_response;
6823 ssh_set_frozen(ssh, 0);
6824 if (s->dlgret == 0) {
6825 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6830 sfree(s->fingerprint);
6832 * Save this host key, to check against the one presented in
6833 * subsequent rekeys.
6835 ssh->hostkey_str = s->keystr;
6838 * In a rekey, we never present an interactive host key
6839 * verification request to the user. Instead, we simply
6840 * enforce that the key we're seeing this time is identical to
6841 * the one we saw before.
6843 if (strcmp(ssh->hostkey_str, s->keystr)) {
6844 bombout(("Host key was different in repeat key exchange"));
6849 ssh->hostkey->freekey(s->hkey);
6852 * The exchange hash from the very first key exchange is also
6853 * the session id, used in session key construction and
6856 if (!s->got_session_id) {
6857 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6858 memcpy(ssh->v2_session_id, s->exchange_hash,
6859 sizeof(s->exchange_hash));
6860 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6861 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6862 s->got_session_id = TRUE;
6866 * Send SSH2_MSG_NEWKEYS.
6868 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6869 ssh2_pkt_send_noqueue(ssh, s->pktout);
6870 ssh->outgoing_data_size = 0; /* start counting from here */
6873 * We've sent client NEWKEYS, so create and initialise
6874 * client-to-server session keys.
6876 if (ssh->cs_cipher_ctx)
6877 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6878 ssh->cscipher = s->cscipher_tobe;
6879 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6881 if (ssh->cs_mac_ctx)
6882 ssh->csmac->free_context(ssh->cs_mac_ctx);
6883 ssh->csmac = s->csmac_tobe;
6884 ssh->cs_mac_ctx = ssh->csmac->make_context();
6886 if (ssh->cs_comp_ctx)
6887 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6888 ssh->cscomp = s->cscomp_tobe;
6889 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6892 * Set IVs on client-to-server keys. Here we use the exchange
6893 * hash from the _first_ key exchange.
6896 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6897 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6898 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6899 assert((ssh->cscipher->keylen+7) / 8 <=
6900 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6901 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6902 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6903 assert(ssh->cscipher->blksize <=
6904 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6905 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6906 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6907 assert(ssh->csmac->len <=
6908 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6909 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6910 smemclr(keyspace, sizeof(keyspace));
6913 logeventf(ssh, "Initialised %.200s client->server encryption",
6914 ssh->cscipher->text_name);
6915 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6916 ssh->csmac->text_name);
6917 if (ssh->cscomp->text_name)
6918 logeventf(ssh, "Initialised %s compression",
6919 ssh->cscomp->text_name);
6922 * Now our end of the key exchange is complete, we can send all
6923 * our queued higher-layer packets.
6925 ssh->queueing = FALSE;
6926 ssh2_pkt_queuesend(ssh);
6929 * Expect SSH2_MSG_NEWKEYS from server.
6931 crWaitUntilV(pktin);
6932 if (pktin->type != SSH2_MSG_NEWKEYS) {
6933 bombout(("expected new-keys packet from server"));
6936 ssh->incoming_data_size = 0; /* start counting from here */
6939 * We've seen server NEWKEYS, so create and initialise
6940 * server-to-client session keys.
6942 if (ssh->sc_cipher_ctx)
6943 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6944 ssh->sccipher = s->sccipher_tobe;
6945 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6947 if (ssh->sc_mac_ctx)
6948 ssh->scmac->free_context(ssh->sc_mac_ctx);
6949 ssh->scmac = s->scmac_tobe;
6950 ssh->sc_mac_ctx = ssh->scmac->make_context();
6952 if (ssh->sc_comp_ctx)
6953 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6954 ssh->sccomp = s->sccomp_tobe;
6955 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6958 * Set IVs on server-to-client keys. Here we use the exchange
6959 * hash from the _first_ key exchange.
6962 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6963 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6964 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6965 assert((ssh->sccipher->keylen+7) / 8 <=
6966 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6967 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6968 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6969 assert(ssh->sccipher->blksize <=
6970 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6971 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6972 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6973 assert(ssh->scmac->len <=
6974 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6975 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6976 smemclr(keyspace, sizeof(keyspace));
6978 logeventf(ssh, "Initialised %.200s server->client encryption",
6979 ssh->sccipher->text_name);
6980 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6981 ssh->scmac->text_name);
6982 if (ssh->sccomp->text_name)
6983 logeventf(ssh, "Initialised %s decompression",
6984 ssh->sccomp->text_name);
6987 * Free shared secret.
6992 * Key exchange is over. Loop straight back round if we have a
6993 * deferred rekey reason.
6995 if (ssh->deferred_rekey_reason) {
6996 logevent(ssh->deferred_rekey_reason);
6998 ssh->deferred_rekey_reason = NULL;
6999 goto begin_key_exchange;
7003 * Otherwise, schedule a timer for our next rekey.
7005 ssh->kex_in_progress = FALSE;
7006 ssh->last_rekey = GETTICKCOUNT();
7007 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7008 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7012 * Now we're encrypting. Begin returning 1 to the protocol main
7013 * function so that other things can run on top of the
7014 * transport. If we ever see a KEXINIT, we must go back to the
7017 * We _also_ go back to the start if we see pktin==NULL and
7018 * inlen negative, because this is a special signal meaning
7019 * `initiate client-driven rekey', and `in' contains a message
7020 * giving the reason for the rekey.
7022 * inlen==-1 means always initiate a rekey;
7023 * inlen==-2 means that userauth has completed successfully and
7024 * we should consider rekeying (for delayed compression).
7026 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7027 (!pktin && inlen < 0))) {
7029 if (!ssh->protocol_initial_phase_done) {
7030 ssh->protocol_initial_phase_done = TRUE;
7032 * Allow authconn to initialise itself.
7034 do_ssh2_authconn(ssh, NULL, 0, NULL);
7039 logevent("Server initiated key re-exchange");
7043 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7044 * delayed compression, if it's available.
7046 * draft-miller-secsh-compression-delayed-00 says that you
7047 * negotiate delayed compression in the first key exchange, and
7048 * both sides start compressing when the server has sent
7049 * USERAUTH_SUCCESS. This has a race condition -- the server
7050 * can't know when the client has seen it, and thus which incoming
7051 * packets it should treat as compressed.
7053 * Instead, we do the initial key exchange without offering the
7054 * delayed methods, but note if the server offers them; when we
7055 * get here, if a delayed method was available that was higher
7056 * on our list than what we got, we initiate a rekey in which we
7057 * _do_ list the delayed methods (and hopefully get it as a
7058 * result). Subsequent rekeys will do the same.
7060 assert(!s->userauth_succeeded); /* should only happen once */
7061 s->userauth_succeeded = TRUE;
7062 if (!s->pending_compression)
7063 /* Can't see any point rekeying. */
7064 goto wait_for_rekey; /* this is utterly horrid */
7065 /* else fall through to rekey... */
7066 s->pending_compression = FALSE;
7069 * Now we've decided to rekey.
7071 * Special case: if the server bug is set that doesn't
7072 * allow rekeying, we give a different log message and
7073 * continue waiting. (If such a server _initiates_ a rekey,
7074 * we process it anyway!)
7076 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7077 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7079 /* Reset the counters, so that at least this message doesn't
7080 * hit the event log _too_ often. */
7081 ssh->outgoing_data_size = 0;
7082 ssh->incoming_data_size = 0;
7083 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7085 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7088 goto wait_for_rekey; /* this is still utterly horrid */
7090 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7093 goto begin_key_exchange;
7099 * Add data to an SSH-2 channel output buffer.
7101 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7104 bufchain_add(&c->v.v2.outbuffer, buf, len);
7108 * Attempt to send data on an SSH-2 channel.
7110 static int ssh2_try_send(struct ssh_channel *c)
7113 struct Packet *pktout;
7116 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7119 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7120 if ((unsigned)len > c->v.v2.remwindow)
7121 len = c->v.v2.remwindow;
7122 if ((unsigned)len > c->v.v2.remmaxpkt)
7123 len = c->v.v2.remmaxpkt;
7124 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7125 ssh2_pkt_adduint32(pktout, c->remoteid);
7126 ssh2_pkt_addstring_start(pktout);
7127 ssh2_pkt_addstring_data(pktout, data, len);
7128 ssh2_pkt_send(ssh, pktout);
7129 bufchain_consume(&c->v.v2.outbuffer, len);
7130 c->v.v2.remwindow -= len;
7134 * After having sent as much data as we can, return the amount
7137 ret = bufchain_size(&c->v.v2.outbuffer);
7140 * And if there's no data pending but we need to send an EOF, send
7143 if (!ret && c->pending_eof)
7144 ssh_channel_try_eof(c);
7149 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7152 if (c->closes & CLOSES_SENT_EOF)
7153 return; /* don't send on channels we've EOFed */
7154 bufsize = ssh2_try_send(c);
7157 case CHAN_MAINSESSION:
7158 /* stdin need not receive an unthrottle
7159 * notification since it will be polled */
7162 x11_unthrottle(c->u.x11.xconn);
7165 /* agent sockets are request/response and need no
7166 * buffer management */
7169 pfd_unthrottle(c->u.pfd.pf);
7175 static int ssh_is_simple(Ssh ssh)
7178 * We use the 'simple' variant of the SSH protocol if we're asked
7179 * to, except not if we're also doing connection-sharing (either
7180 * tunnelling our packets over an upstream or expecting to be
7181 * tunnelled over ourselves), since then the assumption that we
7182 * have only one channel to worry about is not true after all.
7184 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7185 !ssh->bare_connection && !ssh->connshare);
7189 * Set up most of a new ssh_channel for SSH-2.
7191 static void ssh2_channel_init(struct ssh_channel *c)
7194 c->localid = alloc_channel_id(ssh);
7196 c->pending_eof = FALSE;
7197 c->throttling_conn = FALSE;
7198 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7199 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7200 c->v.v2.chanreq_head = NULL;
7201 c->v.v2.throttle_state = UNTHROTTLED;
7202 bufchain_init(&c->v.v2.outbuffer);
7206 * Construct the common parts of a CHANNEL_OPEN.
7208 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7210 struct Packet *pktout;
7212 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7213 ssh2_pkt_addstring(pktout, type);
7214 ssh2_pkt_adduint32(pktout, c->localid);
7215 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7216 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7221 * CHANNEL_FAILURE doesn't come with any indication of what message
7222 * caused it, so we have to keep track of the outstanding
7223 * CHANNEL_REQUESTs ourselves.
7225 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7226 cchandler_fn_t handler, void *ctx)
7228 struct outstanding_channel_request *ocr =
7229 snew(struct outstanding_channel_request);
7231 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7232 ocr->handler = handler;
7235 if (!c->v.v2.chanreq_head)
7236 c->v.v2.chanreq_head = ocr;
7238 c->v.v2.chanreq_tail->next = ocr;
7239 c->v.v2.chanreq_tail = ocr;
7243 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7244 * NULL then a reply will be requested and the handler will be called
7245 * when it arrives. The returned packet is ready to have any
7246 * request-specific data added and be sent. Note that if a handler is
7247 * provided, it's essential that the request actually be sent.
7249 * The handler will usually be passed the response packet in pktin. If
7250 * pktin is NULL, this means that no reply will ever be forthcoming
7251 * (e.g. because the entire connection is being destroyed, or because
7252 * the server initiated channel closure before we saw the response)
7253 * and the handler should free any storage it's holding.
7255 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7256 cchandler_fn_t handler, void *ctx)
7258 struct Packet *pktout;
7260 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7261 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7262 ssh2_pkt_adduint32(pktout, c->remoteid);
7263 ssh2_pkt_addstring(pktout, type);
7264 ssh2_pkt_addbool(pktout, handler != NULL);
7265 if (handler != NULL)
7266 ssh2_queue_chanreq_handler(c, handler, ctx);
7271 * Potentially enlarge the window on an SSH-2 channel.
7273 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7275 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7280 * Never send WINDOW_ADJUST for a channel that the remote side has
7281 * already sent EOF on; there's no point, since it won't be
7282 * sending any more data anyway. Ditto if _we've_ already sent
7285 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7289 * Also, never widen the window for an X11 channel when we're
7290 * still waiting to see its initial auth and may yet hand it off
7293 if (c->type == CHAN_X11 && c->u.x11.initial)
7297 * If the remote end has a habit of ignoring maxpkt, limit the
7298 * window so that it has no choice (assuming it doesn't ignore the
7301 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7302 newwin = OUR_V2_MAXPKT;
7305 * Only send a WINDOW_ADJUST if there's significantly more window
7306 * available than the other end thinks there is. This saves us
7307 * sending a WINDOW_ADJUST for every character in a shell session.
7309 * "Significant" is arbitrarily defined as half the window size.
7311 if (newwin / 2 >= c->v.v2.locwindow) {
7312 struct Packet *pktout;
7316 * In order to keep track of how much window the client
7317 * actually has available, we'd like it to acknowledge each
7318 * WINDOW_ADJUST. We can't do that directly, so we accompany
7319 * it with a CHANNEL_REQUEST that has to be acknowledged.
7321 * This is only necessary if we're opening the window wide.
7322 * If we're not, then throughput is being constrained by
7323 * something other than the maximum window size anyway.
7325 if (newwin == c->v.v2.locmaxwin &&
7326 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7327 up = snew(unsigned);
7328 *up = newwin - c->v.v2.locwindow;
7329 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7330 ssh2_handle_winadj_response, up);
7331 ssh2_pkt_send(ssh, pktout);
7333 if (c->v.v2.throttle_state != UNTHROTTLED)
7334 c->v.v2.throttle_state = UNTHROTTLING;
7336 /* Pretend the WINDOW_ADJUST was acked immediately. */
7337 c->v.v2.remlocwin = newwin;
7338 c->v.v2.throttle_state = THROTTLED;
7340 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7341 ssh2_pkt_adduint32(pktout, c->remoteid);
7342 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7343 ssh2_pkt_send(ssh, pktout);
7344 c->v.v2.locwindow = newwin;
7349 * Find the channel associated with a message. If there's no channel,
7350 * or it's not properly open, make a noise about it and return NULL.
7352 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7354 unsigned localid = ssh_pkt_getuint32(pktin);
7355 struct ssh_channel *c;
7357 c = find234(ssh->channels, &localid, ssh_channelfind);
7359 (c->type != CHAN_SHARING && c->halfopen &&
7360 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7361 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7362 char *buf = dupprintf("Received %s for %s channel %u",
7363 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7365 c ? "half-open" : "nonexistent", localid);
7366 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7373 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7374 struct Packet *pktin, void *ctx)
7376 unsigned *sizep = ctx;
7379 * Winadj responses should always be failures. However, at least
7380 * one server ("boks_sshd") is known to return SUCCESS for channel
7381 * requests it's never heard of, such as "winadj@putty". Raised
7382 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7383 * life, we don't worry about what kind of response we got.
7386 c->v.v2.remlocwin += *sizep;
7389 * winadj messages are only sent when the window is fully open, so
7390 * if we get an ack of one, we know any pending unthrottle is
7393 if (c->v.v2.throttle_state == UNTHROTTLING)
7394 c->v.v2.throttle_state = UNTHROTTLED;
7397 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7399 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7400 struct outstanding_channel_request *ocr;
7403 if (c->type == CHAN_SHARING) {
7404 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7405 pktin->body, pktin->length);
7408 ocr = c->v.v2.chanreq_head;
7410 ssh2_msg_unexpected(ssh, pktin);
7413 ocr->handler(c, pktin, ocr->ctx);
7414 c->v.v2.chanreq_head = ocr->next;
7417 * We may now initiate channel-closing procedures, if that
7418 * CHANNEL_REQUEST was the last thing outstanding before we send
7421 ssh2_channel_check_close(c);
7424 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7426 struct ssh_channel *c;
7427 c = ssh2_channel_msg(ssh, pktin);
7430 if (c->type == CHAN_SHARING) {
7431 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7432 pktin->body, pktin->length);
7435 if (!(c->closes & CLOSES_SENT_EOF)) {
7436 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7437 ssh2_try_send_and_unthrottle(ssh, c);
7441 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7445 struct ssh_channel *c;
7446 c = ssh2_channel_msg(ssh, pktin);
7449 if (c->type == CHAN_SHARING) {
7450 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7451 pktin->body, pktin->length);
7454 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7455 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7456 return; /* extended but not stderr */
7457 ssh_pkt_getstring(pktin, &data, &length);
7460 c->v.v2.locwindow -= length;
7461 c->v.v2.remlocwin -= length;
7463 case CHAN_MAINSESSION:
7465 from_backend(ssh->frontend, pktin->type ==
7466 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7470 bufsize = x11_send(c->u.x11.xconn, data, length);
7473 bufsize = pfd_send(c->u.pfd.pf, data, length);
7476 while (length > 0) {
7477 if (c->u.a.lensofar < 4) {
7478 unsigned int l = min(4 - c->u.a.lensofar,
7480 memcpy(c->u.a.msglen + c->u.a.lensofar,
7484 c->u.a.lensofar += l;
7486 if (c->u.a.lensofar == 4) {
7488 4 + GET_32BIT(c->u.a.msglen);
7489 c->u.a.message = snewn(c->u.a.totallen,
7491 memcpy(c->u.a.message, c->u.a.msglen, 4);
7493 if (c->u.a.lensofar >= 4 && length > 0) {
7495 min(c->u.a.totallen - c->u.a.lensofar,
7497 memcpy(c->u.a.message + c->u.a.lensofar,
7501 c->u.a.lensofar += l;
7503 if (c->u.a.lensofar == c->u.a.totallen) {
7506 c->u.a.outstanding_requests++;
7507 if (agent_query(c->u.a.message,
7510 ssh_agentf_callback, c))
7511 ssh_agentf_callback(c, reply, replylen);
7512 sfree(c->u.a.message);
7513 c->u.a.message = NULL;
7514 c->u.a.lensofar = 0;
7521 * If it looks like the remote end hit the end of its window,
7522 * and we didn't want it to do that, think about using a
7525 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7526 c->v.v2.locmaxwin < 0x40000000)
7527 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7529 * If we are not buffering too much data,
7530 * enlarge the window again at the remote side.
7531 * If we are buffering too much, we may still
7532 * need to adjust the window if the server's
7535 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7536 c->v.v2.locmaxwin - bufsize : 0);
7538 * If we're either buffering way too much data, or if we're
7539 * buffering anything at all and we're in "simple" mode,
7540 * throttle the whole channel.
7542 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7543 && !c->throttling_conn) {
7544 c->throttling_conn = 1;
7545 ssh_throttle_conn(ssh, +1);
7550 static void ssh_check_termination(Ssh ssh)
7552 if (ssh->version == 2 &&
7553 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7554 count234(ssh->channels) == 0 &&
7555 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7557 * We used to send SSH_MSG_DISCONNECT here, because I'd
7558 * believed that _every_ conforming SSH-2 connection had to
7559 * end with a disconnect being sent by at least one side;
7560 * apparently I was wrong and it's perfectly OK to
7561 * unceremoniously slam the connection shut when you're done,
7562 * and indeed OpenSSH feels this is more polite than sending a
7563 * DISCONNECT. So now we don't.
7565 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7569 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7571 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7574 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7576 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7577 ssh_check_termination(ssh);
7580 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7585 va_start(ap, logfmt);
7586 buf = dupvprintf(logfmt, ap);
7589 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7591 logeventf(ssh, "Connection sharing: %s", buf);
7595 static void ssh_channel_destroy(struct ssh_channel *c)
7600 case CHAN_MAINSESSION:
7601 ssh->mainchan = NULL;
7602 update_specials_menu(ssh->frontend);
7605 if (c->u.x11.xconn != NULL)
7606 x11_close(c->u.x11.xconn);
7607 logevent("Forwarded X11 connection terminated");
7610 sfree(c->u.a.message);
7613 if (c->u.pfd.pf != NULL)
7614 pfd_close(c->u.pfd.pf);
7615 logevent("Forwarded port closed");
7619 del234(ssh->channels, c);
7620 if (ssh->version == 2) {
7621 bufchain_clear(&c->v.v2.outbuffer);
7622 assert(c->v.v2.chanreq_head == NULL);
7627 * If that was the last channel left open, we might need to
7630 ssh_check_termination(ssh);
7633 static void ssh2_channel_check_close(struct ssh_channel *c)
7636 struct Packet *pktout;
7640 * If we've sent out our own CHANNEL_OPEN but not yet seen
7641 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7642 * it's too early to be sending close messages of any kind.
7647 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7648 c->type == CHAN_ZOMBIE) &&
7649 !c->v.v2.chanreq_head &&
7650 !(c->closes & CLOSES_SENT_CLOSE)) {
7652 * We have both sent and received EOF (or the channel is a
7653 * zombie), and we have no outstanding channel requests, which
7654 * means the channel is in final wind-up. But we haven't sent
7655 * CLOSE, so let's do so now.
7657 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7658 ssh2_pkt_adduint32(pktout, c->remoteid);
7659 ssh2_pkt_send(ssh, pktout);
7660 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7663 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7664 assert(c->v.v2.chanreq_head == NULL);
7666 * We have both sent and received CLOSE, which means we're
7667 * completely done with the channel.
7669 ssh_channel_destroy(c);
7673 static void ssh2_channel_got_eof(struct ssh_channel *c)
7675 if (c->closes & CLOSES_RCVD_EOF)
7676 return; /* already seen EOF */
7677 c->closes |= CLOSES_RCVD_EOF;
7679 if (c->type == CHAN_X11) {
7680 x11_send_eof(c->u.x11.xconn);
7681 } else if (c->type == CHAN_AGENT) {
7682 if (c->u.a.outstanding_requests == 0) {
7683 /* Manufacture an outgoing EOF in response to the incoming one. */
7684 sshfwd_write_eof(c);
7686 } else if (c->type == CHAN_SOCKDATA) {
7687 pfd_send_eof(c->u.pfd.pf);
7688 } else if (c->type == CHAN_MAINSESSION) {
7691 if (!ssh->sent_console_eof &&
7692 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7694 * Either from_backend_eof told us that the front end
7695 * wants us to close the outgoing side of the connection
7696 * as soon as we see EOF from the far end, or else we've
7697 * unilaterally decided to do that because we've allocated
7698 * a remote pty and hence EOF isn't a particularly
7699 * meaningful concept.
7701 sshfwd_write_eof(c);
7703 ssh->sent_console_eof = TRUE;
7706 ssh2_channel_check_close(c);
7709 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7711 struct ssh_channel *c;
7713 c = ssh2_channel_msg(ssh, pktin);
7716 if (c->type == CHAN_SHARING) {
7717 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7718 pktin->body, pktin->length);
7721 ssh2_channel_got_eof(c);
7724 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7726 struct ssh_channel *c;
7728 c = ssh2_channel_msg(ssh, pktin);
7731 if (c->type == CHAN_SHARING) {
7732 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7733 pktin->body, pktin->length);
7738 * When we receive CLOSE on a channel, we assume it comes with an
7739 * implied EOF if we haven't seen EOF yet.
7741 ssh2_channel_got_eof(c);
7743 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7745 * It also means we stop expecting to see replies to any
7746 * outstanding channel requests, so clean those up too.
7747 * (ssh_chanreq_init will enforce by assertion that we don't
7748 * subsequently put anything back on this list.)
7750 while (c->v.v2.chanreq_head) {
7751 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7752 ocr->handler(c, NULL, ocr->ctx);
7753 c->v.v2.chanreq_head = ocr->next;
7759 * And we also send an outgoing EOF, if we haven't already, on the
7760 * assumption that CLOSE is a pretty forceful announcement that
7761 * the remote side is doing away with the entire channel. (If it
7762 * had wanted to send us EOF and continue receiving data from us,
7763 * it would have just sent CHANNEL_EOF.)
7765 if (!(c->closes & CLOSES_SENT_EOF)) {
7767 * Make sure we don't read any more from whatever our local
7768 * data source is for this channel.
7771 case CHAN_MAINSESSION:
7772 ssh->send_ok = 0; /* stop trying to read from stdin */
7775 x11_override_throttle(c->u.x11.xconn, 1);
7778 pfd_override_throttle(c->u.pfd.pf, 1);
7783 * Abandon any buffered data we still wanted to send to this
7784 * channel. Receiving a CHANNEL_CLOSE is an indication that
7785 * the server really wants to get on and _destroy_ this
7786 * channel, and it isn't going to send us any further
7787 * WINDOW_ADJUSTs to permit us to send pending stuff.
7789 bufchain_clear(&c->v.v2.outbuffer);
7792 * Send outgoing EOF.
7794 sshfwd_write_eof(c);
7798 * Now process the actual close.
7800 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7801 c->closes |= CLOSES_RCVD_CLOSE;
7802 ssh2_channel_check_close(c);
7806 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7808 struct ssh_channel *c;
7810 c = ssh2_channel_msg(ssh, pktin);
7813 if (c->type == CHAN_SHARING) {
7814 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7815 pktin->body, pktin->length);
7818 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7819 c->remoteid = ssh_pkt_getuint32(pktin);
7820 c->halfopen = FALSE;
7821 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7822 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7824 if (c->type == CHAN_SOCKDATA_DORMANT) {
7825 c->type = CHAN_SOCKDATA;
7827 pfd_confirm(c->u.pfd.pf);
7828 } else if (c->type == CHAN_ZOMBIE) {
7830 * This case can occur if a local socket error occurred
7831 * between us sending out CHANNEL_OPEN and receiving
7832 * OPEN_CONFIRMATION. In this case, all we can do is
7833 * immediately initiate close proceedings now that we know the
7834 * server's id to put in the close message.
7836 ssh2_channel_check_close(c);
7839 * We never expect to receive OPEN_CONFIRMATION for any
7840 * *other* channel type (since only local-to-remote port
7841 * forwardings cause us to send CHANNEL_OPEN after the main
7842 * channel is live - all other auxiliary channel types are
7843 * initiated from the server end). It's safe to enforce this
7844 * by assertion rather than by ssh_disconnect, because the
7845 * real point is that we never constructed a half-open channel
7846 * structure in the first place with any type other than the
7849 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7853 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7856 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7858 static const char *const reasons[] = {
7859 "<unknown reason code>",
7860 "Administratively prohibited",
7862 "Unknown channel type",
7863 "Resource shortage",
7865 unsigned reason_code;
7866 char *reason_string;
7868 struct ssh_channel *c;
7870 c = ssh2_channel_msg(ssh, pktin);
7873 if (c->type == CHAN_SHARING) {
7874 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7875 pktin->body, pktin->length);
7878 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7880 if (c->type == CHAN_SOCKDATA_DORMANT) {
7881 reason_code = ssh_pkt_getuint32(pktin);
7882 if (reason_code >= lenof(reasons))
7883 reason_code = 0; /* ensure reasons[reason_code] in range */
7884 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7885 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7886 reasons[reason_code], reason_length, reason_string);
7888 pfd_close(c->u.pfd.pf);
7889 } else if (c->type == CHAN_ZOMBIE) {
7891 * This case can occur if a local socket error occurred
7892 * between us sending out CHANNEL_OPEN and receiving
7893 * OPEN_FAILURE. In this case, we need do nothing except allow
7894 * the code below to throw the half-open channel away.
7898 * We never expect to receive OPEN_FAILURE for any *other*
7899 * channel type (since only local-to-remote port forwardings
7900 * cause us to send CHANNEL_OPEN after the main channel is
7901 * live - all other auxiliary channel types are initiated from
7902 * the server end). It's safe to enforce this by assertion
7903 * rather than by ssh_disconnect, because the real point is
7904 * that we never constructed a half-open channel structure in
7905 * the first place with any type other than the above.
7907 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7910 del234(ssh->channels, c);
7914 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7917 int typelen, want_reply;
7918 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7919 struct ssh_channel *c;
7920 struct Packet *pktout;
7922 c = ssh2_channel_msg(ssh, pktin);
7925 if (c->type == CHAN_SHARING) {
7926 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7927 pktin->body, pktin->length);
7930 ssh_pkt_getstring(pktin, &type, &typelen);
7931 want_reply = ssh2_pkt_getbool(pktin);
7933 if (c->closes & CLOSES_SENT_CLOSE) {
7935 * We don't reply to channel requests after we've sent
7936 * CHANNEL_CLOSE for the channel, because our reply might
7937 * cross in the network with the other side's CHANNEL_CLOSE
7938 * and arrive after they have wound the channel up completely.
7944 * Having got the channel number, we now look at
7945 * the request type string to see if it's something
7948 if (c == ssh->mainchan) {
7950 * We recognise "exit-status" and "exit-signal" on
7951 * the primary channel.
7953 if (typelen == 11 &&
7954 !memcmp(type, "exit-status", 11)) {
7956 ssh->exitcode = ssh_pkt_getuint32(pktin);
7957 logeventf(ssh, "Server sent command exit status %d",
7959 reply = SSH2_MSG_CHANNEL_SUCCESS;
7961 } else if (typelen == 11 &&
7962 !memcmp(type, "exit-signal", 11)) {
7964 int is_plausible = TRUE, is_int = FALSE;
7965 char *fmt_sig = "", *fmt_msg = "";
7967 int msglen = 0, core = FALSE;
7968 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7969 * provide an `int' for the signal, despite its
7970 * having been a `string' in the drafts of RFC 4254 since at
7971 * least 2001. (Fixed in session.c 1.147.) Try to
7972 * infer which we can safely parse it as. */
7974 unsigned char *p = pktin->body +
7976 long len = pktin->length - pktin->savedpos;
7977 unsigned long num = GET_32BIT(p); /* what is it? */
7978 /* If it's 0, it hardly matters; assume string */
7982 int maybe_int = FALSE, maybe_str = FALSE;
7983 #define CHECK_HYPOTHESIS(offset, result) \
7986 int q = toint(offset); \
7987 if (q >= 0 && q+4 <= len) { \
7988 q = toint(q + 4 + GET_32BIT(p+q)); \
7989 if (q >= 0 && q+4 <= len && \
7990 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7995 CHECK_HYPOTHESIS(4+1, maybe_int);
7996 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7997 #undef CHECK_HYPOTHESIS
7998 if (maybe_int && !maybe_str)
8000 else if (!maybe_int && maybe_str)
8003 /* Crikey. Either or neither. Panic. */
8004 is_plausible = FALSE;
8007 ssh->exitcode = 128; /* means `unknown signal' */
8010 /* Old non-standard OpenSSH. */
8011 int signum = ssh_pkt_getuint32(pktin);
8012 fmt_sig = dupprintf(" %d", signum);
8013 ssh->exitcode = 128 + signum;
8015 /* As per RFC 4254. */
8018 ssh_pkt_getstring(pktin, &sig, &siglen);
8019 /* Signal name isn't supposed to be blank, but
8020 * let's cope gracefully if it is. */
8022 fmt_sig = dupprintf(" \"%.*s\"",
8027 * Really hideous method of translating the
8028 * signal description back into a locally
8029 * meaningful number.
8034 #define TRANSLATE_SIGNAL(s) \
8035 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8036 ssh->exitcode = 128 + SIG ## s
8038 TRANSLATE_SIGNAL(ABRT);
8041 TRANSLATE_SIGNAL(ALRM);
8044 TRANSLATE_SIGNAL(FPE);
8047 TRANSLATE_SIGNAL(HUP);
8050 TRANSLATE_SIGNAL(ILL);
8053 TRANSLATE_SIGNAL(INT);
8056 TRANSLATE_SIGNAL(KILL);
8059 TRANSLATE_SIGNAL(PIPE);
8062 TRANSLATE_SIGNAL(QUIT);
8065 TRANSLATE_SIGNAL(SEGV);
8068 TRANSLATE_SIGNAL(TERM);
8071 TRANSLATE_SIGNAL(USR1);
8074 TRANSLATE_SIGNAL(USR2);
8076 #undef TRANSLATE_SIGNAL
8078 ssh->exitcode = 128;
8080 core = ssh2_pkt_getbool(pktin);
8081 ssh_pkt_getstring(pktin, &msg, &msglen);
8083 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8085 /* ignore lang tag */
8086 } /* else don't attempt to parse */
8087 logeventf(ssh, "Server exited on signal%s%s%s",
8088 fmt_sig, core ? " (core dumped)" : "",
8090 if (*fmt_sig) sfree(fmt_sig);
8091 if (*fmt_msg) sfree(fmt_msg);
8092 reply = SSH2_MSG_CHANNEL_SUCCESS;
8097 * This is a channel request we don't know
8098 * about, so we now either ignore the request
8099 * or respond with CHANNEL_FAILURE, depending
8102 reply = SSH2_MSG_CHANNEL_FAILURE;
8105 pktout = ssh2_pkt_init(reply);
8106 ssh2_pkt_adduint32(pktout, c->remoteid);
8107 ssh2_pkt_send(ssh, pktout);
8111 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8114 int typelen, want_reply;
8115 struct Packet *pktout;
8117 ssh_pkt_getstring(pktin, &type, &typelen);
8118 want_reply = ssh2_pkt_getbool(pktin);
8121 * We currently don't support any global requests
8122 * at all, so we either ignore the request or
8123 * respond with REQUEST_FAILURE, depending on
8127 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8128 ssh2_pkt_send(ssh, pktout);
8132 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8136 struct X11FakeAuth *auth;
8139 * Make up a new set of fake X11 auth data, and add it to the tree
8140 * of currently valid ones with an indication of the sharing
8141 * context that it's relevant to.
8143 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8144 auth->share_cs = share_cs;
8145 auth->share_chan = share_chan;
8150 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8152 del234(ssh->x11authtree, auth);
8153 x11_free_fake_auth(auth);
8156 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8164 struct ssh_channel *c;
8165 unsigned remid, winsize, pktsize;
8166 unsigned our_winsize_override = 0;
8167 struct Packet *pktout;
8169 ssh_pkt_getstring(pktin, &type, &typelen);
8170 c = snew(struct ssh_channel);
8173 remid = ssh_pkt_getuint32(pktin);
8174 winsize = ssh_pkt_getuint32(pktin);
8175 pktsize = ssh_pkt_getuint32(pktin);
8177 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8180 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8181 addrstr = snewn(peeraddrlen+1, char);
8182 memcpy(addrstr, peeraddr, peeraddrlen);
8183 addrstr[peeraddrlen] = '\0';
8184 peerport = ssh_pkt_getuint32(pktin);
8186 logeventf(ssh, "Received X11 connect request from %s:%d",
8189 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8190 error = "X11 forwarding is not enabled";
8192 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8195 c->u.x11.initial = TRUE;
8198 * If we are a connection-sharing upstream, then we should
8199 * initially present a very small window, adequate to take
8200 * the X11 initial authorisation packet but not much more.
8201 * Downstream will then present us a larger window (by
8202 * fiat of the connection-sharing protocol) and we can
8203 * guarantee to send a positive-valued WINDOW_ADJUST.
8206 our_winsize_override = 128;
8208 logevent("Opened X11 forward channel");
8212 } else if (typelen == 15 &&
8213 !memcmp(type, "forwarded-tcpip", 15)) {
8214 struct ssh_rportfwd pf, *realpf;
8217 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8218 pf.shost = dupprintf("%.*s", shostlen, shost);
8219 pf.sport = ssh_pkt_getuint32(pktin);
8220 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8221 peerport = ssh_pkt_getuint32(pktin);
8222 realpf = find234(ssh->rportfwds, &pf, NULL);
8223 logeventf(ssh, "Received remote port %s:%d open request "
8224 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8227 if (realpf == NULL) {
8228 error = "Remote port is not recognised";
8232 if (realpf->share_ctx) {
8234 * This port forwarding is on behalf of a
8235 * connection-sharing downstream, so abandon our own
8236 * channel-open procedure and just pass the message on
8239 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8240 pktin->body, pktin->length);
8245 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8246 c, ssh->conf, realpf->pfrec->addressfamily);
8247 logeventf(ssh, "Attempting to forward remote port to "
8248 "%s:%d", realpf->dhost, realpf->dport);
8250 logeventf(ssh, "Port open failed: %s", err);
8252 error = "Port open failed";
8254 logevent("Forwarded port opened successfully");
8255 c->type = CHAN_SOCKDATA;
8258 } else if (typelen == 22 &&
8259 !memcmp(type, "auth-agent@openssh.com", 22)) {
8260 if (!ssh->agentfwd_enabled)
8261 error = "Agent forwarding is not enabled";
8263 c->type = CHAN_AGENT; /* identify channel type */
8264 c->u.a.lensofar = 0;
8265 c->u.a.message = NULL;
8266 c->u.a.outstanding_requests = 0;
8269 error = "Unsupported channel type requested";
8272 c->remoteid = remid;
8273 c->halfopen = FALSE;
8275 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8276 ssh2_pkt_adduint32(pktout, c->remoteid);
8277 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8278 ssh2_pkt_addstring(pktout, error);
8279 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8280 ssh2_pkt_send(ssh, pktout);
8281 logeventf(ssh, "Rejected channel open: %s", error);
8284 ssh2_channel_init(c);
8285 c->v.v2.remwindow = winsize;
8286 c->v.v2.remmaxpkt = pktsize;
8287 if (our_winsize_override) {
8288 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8289 our_winsize_override;
8291 add234(ssh->channels, c);
8292 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8293 ssh2_pkt_adduint32(pktout, c->remoteid);
8294 ssh2_pkt_adduint32(pktout, c->localid);
8295 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8296 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8297 ssh2_pkt_send(ssh, pktout);
8301 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8302 void *share_cs, void *share_chan,
8303 const char *peer_addr, int peer_port,
8304 int endian, int protomajor, int protominor,
8305 const void *initial_data, int initial_len)
8308 * This function is called when we've just discovered that an X
8309 * forwarding channel on which we'd been handling the initial auth
8310 * ourselves turns out to be destined for a connection-sharing
8311 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8312 * that we completely stop tracking windows and buffering data and
8313 * just pass more or less unmodified SSH messages back and forth.
8315 c->type = CHAN_SHARING;
8316 c->u.sharing.ctx = share_cs;
8317 share_setup_x11_channel(share_cs, share_chan,
8318 c->localid, c->remoteid, c->v.v2.remwindow,
8319 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8320 peer_addr, peer_port, endian,
8321 protomajor, protominor,
8322 initial_data, initial_len);
8325 void sshfwd_x11_is_local(struct ssh_channel *c)
8328 * This function is called when we've just discovered that an X
8329 * forwarding channel is _not_ destined for a connection-sharing
8330 * downstream but we're going to handle it ourselves. We stop
8331 * presenting a cautiously small window and go into ordinary data
8334 c->u.x11.initial = FALSE;
8335 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8339 * Buffer banner messages for later display at some convenient point,
8340 * if we're going to display them.
8342 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8344 /* Arbitrary limit to prevent unbounded inflation of buffer */
8345 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8346 bufchain_size(&ssh->banner) <= 131072) {
8347 char *banner = NULL;
8349 ssh_pkt_getstring(pktin, &banner, &size);
8351 bufchain_add(&ssh->banner, banner, size);
8355 /* Helper function to deal with sending tty modes for "pty-req" */
8356 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8358 struct Packet *pktout = (struct Packet *)data;
8360 unsigned int arg = 0;
8361 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8362 if (i == lenof(ssh_ttymodes)) return;
8363 switch (ssh_ttymodes[i].type) {
8365 arg = ssh_tty_parse_specchar(val);
8368 arg = ssh_tty_parse_boolean(val);
8371 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8372 ssh2_pkt_adduint32(pktout, arg);
8375 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8378 struct ssh2_setup_x11_state {
8382 struct Packet *pktout;
8383 crStateP(ssh2_setup_x11_state, ctx);
8387 logevent("Requesting X11 forwarding");
8388 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8390 ssh2_pkt_addbool(pktout, 0); /* many connections */
8391 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8392 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8393 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8394 ssh2_pkt_send(ssh, pktout);
8396 /* Wait to be called back with either a response packet, or NULL
8397 * meaning clean up and free our data */
8401 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8402 logevent("X11 forwarding enabled");
8403 ssh->X11_fwd_enabled = TRUE;
8405 logevent("X11 forwarding refused");
8411 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8414 struct ssh2_setup_agent_state {
8418 struct Packet *pktout;
8419 crStateP(ssh2_setup_agent_state, ctx);
8423 logevent("Requesting OpenSSH-style agent forwarding");
8424 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8425 ssh2_setup_agent, s);
8426 ssh2_pkt_send(ssh, pktout);
8428 /* Wait to be called back with either a response packet, or NULL
8429 * meaning clean up and free our data */
8433 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8434 logevent("Agent forwarding enabled");
8435 ssh->agentfwd_enabled = TRUE;
8437 logevent("Agent forwarding refused");
8443 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8446 struct ssh2_setup_pty_state {
8450 struct Packet *pktout;
8451 crStateP(ssh2_setup_pty_state, ctx);
8455 /* Unpick the terminal-speed string. */
8456 /* XXX perhaps we should allow no speeds to be sent. */
8457 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8458 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8459 /* Build the pty request. */
8460 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8462 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8463 ssh2_pkt_adduint32(pktout, ssh->term_width);
8464 ssh2_pkt_adduint32(pktout, ssh->term_height);
8465 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8466 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8467 ssh2_pkt_addstring_start(pktout);
8468 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8469 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8470 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8471 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8472 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8473 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8474 ssh2_pkt_send(ssh, pktout);
8475 ssh->state = SSH_STATE_INTERMED;
8477 /* Wait to be called back with either a response packet, or NULL
8478 * meaning clean up and free our data */
8482 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8483 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8484 ssh->ospeed, ssh->ispeed);
8485 ssh->got_pty = TRUE;
8487 c_write_str(ssh, "Server refused to allocate pty\r\n");
8488 ssh->editing = ssh->echoing = 1;
8495 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8498 struct ssh2_setup_env_state {
8500 int num_env, env_left, env_ok;
8503 struct Packet *pktout;
8504 crStateP(ssh2_setup_env_state, ctx);
8509 * Send environment variables.
8511 * Simplest thing here is to send all the requests at once, and
8512 * then wait for a whole bunch of successes or failures.
8518 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8520 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8521 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8522 ssh2_pkt_addstring(pktout, key);
8523 ssh2_pkt_addstring(pktout, val);
8524 ssh2_pkt_send(ssh, pktout);
8529 logeventf(ssh, "Sent %d environment variables", s->num_env);
8534 s->env_left = s->num_env;
8536 while (s->env_left > 0) {
8537 /* Wait to be called back with either a response packet,
8538 * or NULL meaning clean up and free our data */
8540 if (!pktin) goto out;
8541 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8546 if (s->env_ok == s->num_env) {
8547 logevent("All environment variables successfully set");
8548 } else if (s->env_ok == 0) {
8549 logevent("All environment variables refused");
8550 c_write_str(ssh, "Server refused to set environment variables\r\n");
8552 logeventf(ssh, "%d environment variables refused",
8553 s->num_env - s->env_ok);
8554 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8562 * Handle the SSH-2 userauth and connection layers.
8564 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8566 do_ssh2_authconn(ssh, NULL, 0, pktin);
8569 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8573 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8576 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8577 struct Packet *pktin)
8579 struct do_ssh2_authconn_state {
8583 AUTH_TYPE_PUBLICKEY,
8584 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8585 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8587 AUTH_TYPE_GSSAPI, /* always QUIET */
8588 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8589 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8591 int done_service_req;
8592 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8593 int tried_pubkey_config, done_agent;
8598 int kbd_inter_refused;
8599 int we_are_in, userauth_success;
8600 prompts_t *cur_prompt;
8605 void *publickey_blob;
8606 int publickey_bloblen;
8607 int publickey_encrypted;
8608 char *publickey_algorithm;
8609 char *publickey_comment;
8610 unsigned char agent_request[5], *agent_response, *agentp;
8611 int agent_responselen;
8612 unsigned char *pkblob_in_agent;
8614 char *pkblob, *alg, *commentp;
8615 int pklen, alglen, commentlen;
8616 int siglen, retlen, len;
8617 char *q, *agentreq, *ret;
8619 struct Packet *pktout;
8622 struct ssh_gss_library *gsslib;
8623 Ssh_gss_ctx gss_ctx;
8624 Ssh_gss_buf gss_buf;
8625 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8626 Ssh_gss_name gss_srv_name;
8627 Ssh_gss_stat gss_stat;
8630 crState(do_ssh2_authconn_state);
8634 /* Register as a handler for all the messages this coroutine handles. */
8635 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8636 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8637 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8638 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8639 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8640 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8641 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8642 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8643 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8644 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8645 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8646 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8647 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8649 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8650 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8651 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8652 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8653 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8654 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8656 s->done_service_req = FALSE;
8657 s->we_are_in = s->userauth_success = FALSE;
8658 s->agent_response = NULL;
8660 s->tried_gssapi = FALSE;
8663 if (!ssh->bare_connection) {
8664 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8666 * Request userauth protocol, and await a response to it.
8668 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8669 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8670 ssh2_pkt_send(ssh, s->pktout);
8671 crWaitUntilV(pktin);
8672 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8673 s->done_service_req = TRUE;
8675 if (!s->done_service_req) {
8677 * Request connection protocol directly, without authentication.
8679 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8680 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8681 ssh2_pkt_send(ssh, s->pktout);
8682 crWaitUntilV(pktin);
8683 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8684 s->we_are_in = TRUE; /* no auth required */
8686 bombout(("Server refused service request"));
8691 s->we_are_in = TRUE;
8694 /* Arrange to be able to deal with any BANNERs that come in.
8695 * (We do this now as packets may come in during the next bit.) */
8696 bufchain_init(&ssh->banner);
8697 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8698 ssh2_msg_userauth_banner;
8701 * Misc one-time setup for authentication.
8703 s->publickey_blob = NULL;
8704 if (!s->we_are_in) {
8707 * Load the public half of any configured public key file
8710 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8711 if (!filename_is_null(s->keyfile)) {
8713 logeventf(ssh, "Reading private key file \"%.150s\"",
8714 filename_to_str(s->keyfile));
8715 keytype = key_type(s->keyfile);
8716 if (keytype == SSH_KEYTYPE_SSH2) {
8719 ssh2_userkey_loadpub(s->keyfile,
8720 &s->publickey_algorithm,
8721 &s->publickey_bloblen,
8722 &s->publickey_comment, &error);
8723 if (s->publickey_blob) {
8724 s->publickey_encrypted =
8725 ssh2_userkey_encrypted(s->keyfile, NULL);
8728 logeventf(ssh, "Unable to load private key (%s)",
8730 msgbuf = dupprintf("Unable to load private key file "
8731 "\"%.150s\" (%s)\r\n",
8732 filename_to_str(s->keyfile),
8734 c_write_str(ssh, msgbuf);
8739 logeventf(ssh, "Unable to use this key file (%s)",
8740 key_type_to_str(keytype));
8741 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8743 filename_to_str(s->keyfile),
8744 key_type_to_str(keytype));
8745 c_write_str(ssh, msgbuf);
8747 s->publickey_blob = NULL;
8752 * Find out about any keys Pageant has (but if there's a
8753 * public key configured, filter out all others).
8756 s->agent_response = NULL;
8757 s->pkblob_in_agent = NULL;
8758 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8762 logevent("Pageant is running. Requesting keys.");
8764 /* Request the keys held by the agent. */
8765 PUT_32BIT(s->agent_request, 1);
8766 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8767 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8768 ssh_agent_callback, ssh)) {
8772 bombout(("Unexpected data from server while"
8773 " waiting for agent response"));
8776 } while (pktin || inlen > 0);
8777 r = ssh->agent_response;
8778 s->agent_responselen = ssh->agent_response_len;
8780 s->agent_response = (unsigned char *) r;
8781 if (s->agent_response && s->agent_responselen >= 5 &&
8782 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8785 p = s->agent_response + 5;
8786 s->nkeys = toint(GET_32BIT(p));
8789 * Vet the Pageant response to ensure that the key
8790 * count and blob lengths make sense.
8793 logeventf(ssh, "Pageant response contained a negative"
8794 " key count %d", s->nkeys);
8796 goto done_agent_query;
8798 unsigned char *q = p + 4;
8799 int lenleft = s->agent_responselen - 5 - 4;
8801 for (keyi = 0; keyi < s->nkeys; keyi++) {
8802 int bloblen, commentlen;
8804 logeventf(ssh, "Pageant response was truncated");
8806 goto done_agent_query;
8808 bloblen = toint(GET_32BIT(q));
8809 if (bloblen < 0 || bloblen > lenleft) {
8810 logeventf(ssh, "Pageant response was truncated");
8812 goto done_agent_query;
8814 lenleft -= 4 + bloblen;
8816 commentlen = toint(GET_32BIT(q));
8817 if (commentlen < 0 || commentlen > lenleft) {
8818 logeventf(ssh, "Pageant response was truncated");
8820 goto done_agent_query;
8822 lenleft -= 4 + commentlen;
8823 q += 4 + commentlen;
8828 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8829 if (s->publickey_blob) {
8830 /* See if configured key is in agent. */
8831 for (keyi = 0; keyi < s->nkeys; keyi++) {
8832 s->pklen = toint(GET_32BIT(p));
8833 if (s->pklen == s->publickey_bloblen &&
8834 !memcmp(p+4, s->publickey_blob,
8835 s->publickey_bloblen)) {
8836 logeventf(ssh, "Pageant key #%d matches "
8837 "configured key file", keyi);
8839 s->pkblob_in_agent = p;
8843 p += toint(GET_32BIT(p)) + 4; /* comment */
8845 if (!s->pkblob_in_agent) {
8846 logevent("Configured key file not in Pageant");
8851 logevent("Failed to get reply from Pageant");
8859 * We repeat this whole loop, including the username prompt,
8860 * until we manage a successful authentication. If the user
8861 * types the wrong _password_, they can be sent back to the
8862 * beginning to try another username, if this is configured on.
8863 * (If they specify a username in the config, they are never
8864 * asked, even if they do give a wrong password.)
8866 * I think this best serves the needs of
8868 * - the people who have no configuration, no keys, and just
8869 * want to try repeated (username,password) pairs until they
8870 * type both correctly
8872 * - people who have keys and configuration but occasionally
8873 * need to fall back to passwords
8875 * - people with a key held in Pageant, who might not have
8876 * logged in to a particular machine before; so they want to
8877 * type a username, and then _either_ their key will be
8878 * accepted, _or_ they will type a password. If they mistype
8879 * the username they will want to be able to get back and
8882 s->got_username = FALSE;
8883 while (!s->we_are_in) {
8887 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8889 * We got a username last time round this loop, and
8890 * with change_username turned off we don't try to get
8893 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8894 int ret; /* need not be kept over crReturn */
8895 s->cur_prompt = new_prompts(ssh->frontend);
8896 s->cur_prompt->to_server = TRUE;
8897 s->cur_prompt->name = dupstr("SSH login name");
8898 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8899 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8902 crWaitUntilV(!pktin);
8903 ret = get_userpass_input(s->cur_prompt, in, inlen);
8908 * get_userpass_input() failed to get a username.
8911 free_prompts(s->cur_prompt);
8912 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8915 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8916 free_prompts(s->cur_prompt);
8919 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8920 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8921 c_write_str(ssh, stuff);
8925 s->got_username = TRUE;
8928 * Send an authentication request using method "none": (a)
8929 * just in case it succeeds, and (b) so that we know what
8930 * authentication methods we can usefully try next.
8932 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8934 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8935 ssh2_pkt_addstring(s->pktout, ssh->username);
8936 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8937 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8938 ssh2_pkt_send(ssh, s->pktout);
8939 s->type = AUTH_TYPE_NONE;
8941 s->we_are_in = FALSE;
8943 s->tried_pubkey_config = FALSE;
8944 s->kbd_inter_refused = FALSE;
8946 /* Reset agent request state. */
8947 s->done_agent = FALSE;
8948 if (s->agent_response) {
8949 if (s->pkblob_in_agent) {
8950 s->agentp = s->pkblob_in_agent;
8952 s->agentp = s->agent_response + 5 + 4;
8958 char *methods = NULL;
8962 * Wait for the result of the last authentication request.
8965 crWaitUntilV(pktin);
8967 * Now is a convenient point to spew any banner material
8968 * that we've accumulated. (This should ensure that when
8969 * we exit the auth loop, we haven't any left to deal
8973 int size = bufchain_size(&ssh->banner);
8975 * Don't show the banner if we're operating in
8976 * non-verbose non-interactive mode. (It's probably
8977 * a script, which means nobody will read the
8978 * banner _anyway_, and moreover the printing of
8979 * the banner will screw up processing on the
8980 * output of (say) plink.)
8982 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8983 char *banner = snewn(size, char);
8984 bufchain_fetch(&ssh->banner, banner, size);
8985 c_write_untrusted(ssh, banner, size);
8988 bufchain_clear(&ssh->banner);
8990 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8991 logevent("Access granted");
8992 s->we_are_in = s->userauth_success = TRUE;
8996 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8997 bombout(("Strange packet received during authentication: "
8998 "type %d", pktin->type));
9005 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9006 * we can look at the string in it and know what we can
9007 * helpfully try next.
9009 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9010 ssh_pkt_getstring(pktin, &methods, &methlen);
9011 if (!ssh2_pkt_getbool(pktin)) {
9013 * We have received an unequivocal Access
9014 * Denied. This can translate to a variety of
9015 * messages, or no message at all.
9017 * For forms of authentication which are attempted
9018 * implicitly, by which I mean without printing
9019 * anything in the window indicating that we're
9020 * trying them, we should never print 'Access
9023 * If we do print a message saying that we're
9024 * attempting some kind of authentication, it's OK
9025 * to print a followup message saying it failed -
9026 * but the message may sometimes be more specific
9027 * than simply 'Access denied'.
9029 * Additionally, if we'd just tried password
9030 * authentication, we should break out of this
9031 * whole loop so as to go back to the username
9032 * prompt (iff we're configured to allow
9033 * username change attempts).
9035 if (s->type == AUTH_TYPE_NONE) {
9037 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9038 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9039 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9040 c_write_str(ssh, "Server refused our key\r\n");
9041 logevent("Server refused our key");
9042 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9043 /* This _shouldn't_ happen except by a
9044 * protocol bug causing client and server to
9045 * disagree on what is a correct signature. */
9046 c_write_str(ssh, "Server refused public-key signature"
9047 " despite accepting key!\r\n");
9048 logevent("Server refused public-key signature"
9049 " despite accepting key!");
9050 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9051 /* quiet, so no c_write */
9052 logevent("Server refused keyboard-interactive authentication");
9053 } else if (s->type==AUTH_TYPE_GSSAPI) {
9054 /* always quiet, so no c_write */
9055 /* also, the code down in the GSSAPI block has
9056 * already logged this in the Event Log */
9057 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9058 logevent("Keyboard-interactive authentication failed");
9059 c_write_str(ssh, "Access denied\r\n");
9061 assert(s->type == AUTH_TYPE_PASSWORD);
9062 logevent("Password authentication failed");
9063 c_write_str(ssh, "Access denied\r\n");
9065 if (conf_get_int(ssh->conf, CONF_change_username)) {
9066 /* XXX perhaps we should allow
9067 * keyboard-interactive to do this too? */
9068 s->we_are_in = FALSE;
9073 c_write_str(ssh, "Further authentication required\r\n");
9074 logevent("Further authentication required");
9078 in_commasep_string("publickey", methods, methlen);
9080 in_commasep_string("password", methods, methlen);
9081 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9082 in_commasep_string("keyboard-interactive", methods, methlen);
9085 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9086 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9087 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9088 ssh->gsslibs->nlibraries > 0;
9092 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9094 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9097 * Attempt public-key authentication using a key from Pageant.
9100 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9102 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9104 /* Unpack key from agent response */
9105 s->pklen = toint(GET_32BIT(s->agentp));
9107 s->pkblob = (char *)s->agentp;
9108 s->agentp += s->pklen;
9109 s->alglen = toint(GET_32BIT(s->pkblob));
9110 s->alg = s->pkblob + 4;
9111 s->commentlen = toint(GET_32BIT(s->agentp));
9113 s->commentp = (char *)s->agentp;
9114 s->agentp += s->commentlen;
9115 /* s->agentp now points at next key, if any */
9117 /* See if server will accept it */
9118 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9119 ssh2_pkt_addstring(s->pktout, ssh->username);
9120 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9121 /* service requested */
9122 ssh2_pkt_addstring(s->pktout, "publickey");
9124 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9125 ssh2_pkt_addstring_start(s->pktout);
9126 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9127 ssh2_pkt_addstring_start(s->pktout);
9128 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9129 ssh2_pkt_send(ssh, s->pktout);
9130 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9132 crWaitUntilV(pktin);
9133 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9135 /* Offer of key refused. */
9142 if (flags & FLAG_VERBOSE) {
9143 c_write_str(ssh, "Authenticating with "
9145 c_write(ssh, s->commentp, s->commentlen);
9146 c_write_str(ssh, "\" from agent\r\n");
9150 * Server is willing to accept the key.
9151 * Construct a SIGN_REQUEST.
9153 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9154 ssh2_pkt_addstring(s->pktout, ssh->username);
9155 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9156 /* service requested */
9157 ssh2_pkt_addstring(s->pktout, "publickey");
9159 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9160 ssh2_pkt_addstring_start(s->pktout);
9161 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9162 ssh2_pkt_addstring_start(s->pktout);
9163 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9165 /* Ask agent for signature. */
9166 s->siglen = s->pktout->length - 5 + 4 +
9167 ssh->v2_session_id_len;
9168 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9170 s->len = 1; /* message type */
9171 s->len += 4 + s->pklen; /* key blob */
9172 s->len += 4 + s->siglen; /* data to sign */
9173 s->len += 4; /* flags */
9174 s->agentreq = snewn(4 + s->len, char);
9175 PUT_32BIT(s->agentreq, s->len);
9176 s->q = s->agentreq + 4;
9177 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9178 PUT_32BIT(s->q, s->pklen);
9180 memcpy(s->q, s->pkblob, s->pklen);
9182 PUT_32BIT(s->q, s->siglen);
9184 /* Now the data to be signed... */
9185 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9186 PUT_32BIT(s->q, ssh->v2_session_id_len);
9189 memcpy(s->q, ssh->v2_session_id,
9190 ssh->v2_session_id_len);
9191 s->q += ssh->v2_session_id_len;
9192 memcpy(s->q, s->pktout->data + 5,
9193 s->pktout->length - 5);
9194 s->q += s->pktout->length - 5;
9195 /* And finally the (zero) flags word. */
9197 if (!agent_query(s->agentreq, s->len + 4,
9199 ssh_agent_callback, ssh)) {
9203 bombout(("Unexpected data from server"
9204 " while waiting for agent"
9208 } while (pktin || inlen > 0);
9209 vret = ssh->agent_response;
9210 s->retlen = ssh->agent_response_len;
9215 if (s->retlen >= 9 &&
9216 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9217 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9218 logevent("Sending Pageant's response");
9219 ssh2_add_sigblob(ssh, s->pktout,
9220 s->pkblob, s->pklen,
9222 GET_32BIT(s->ret + 5));
9223 ssh2_pkt_send(ssh, s->pktout);
9224 s->type = AUTH_TYPE_PUBLICKEY;
9226 /* FIXME: less drastic response */
9227 bombout(("Pageant failed to answer challenge"));
9233 /* Do we have any keys left to try? */
9234 if (s->pkblob_in_agent) {
9235 s->done_agent = TRUE;
9236 s->tried_pubkey_config = TRUE;
9239 if (s->keyi >= s->nkeys)
9240 s->done_agent = TRUE;
9243 } else if (s->can_pubkey && s->publickey_blob &&
9244 !s->tried_pubkey_config) {
9246 struct ssh2_userkey *key; /* not live over crReturn */
9247 char *passphrase; /* not live over crReturn */
9249 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9251 s->tried_pubkey_config = TRUE;
9254 * Try the public key supplied in the configuration.
9256 * First, offer the public blob to see if the server is
9257 * willing to accept it.
9259 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9260 ssh2_pkt_addstring(s->pktout, ssh->username);
9261 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9262 /* service requested */
9263 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9264 ssh2_pkt_addbool(s->pktout, FALSE);
9265 /* no signature included */
9266 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9267 ssh2_pkt_addstring_start(s->pktout);
9268 ssh2_pkt_addstring_data(s->pktout,
9269 (char *)s->publickey_blob,
9270 s->publickey_bloblen);
9271 ssh2_pkt_send(ssh, s->pktout);
9272 logevent("Offered public key");
9274 crWaitUntilV(pktin);
9275 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9276 /* Key refused. Give up. */
9277 s->gotit = TRUE; /* reconsider message next loop */
9278 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9279 continue; /* process this new message */
9281 logevent("Offer of public key accepted");
9284 * Actually attempt a serious authentication using
9287 if (flags & FLAG_VERBOSE) {
9288 c_write_str(ssh, "Authenticating with public key \"");
9289 c_write_str(ssh, s->publickey_comment);
9290 c_write_str(ssh, "\"\r\n");
9294 const char *error; /* not live over crReturn */
9295 if (s->publickey_encrypted) {
9297 * Get a passphrase from the user.
9299 int ret; /* need not be kept over crReturn */
9300 s->cur_prompt = new_prompts(ssh->frontend);
9301 s->cur_prompt->to_server = FALSE;
9302 s->cur_prompt->name = dupstr("SSH key passphrase");
9303 add_prompt(s->cur_prompt,
9304 dupprintf("Passphrase for key \"%.100s\": ",
9305 s->publickey_comment),
9307 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9310 crWaitUntilV(!pktin);
9311 ret = get_userpass_input(s->cur_prompt,
9316 /* Failed to get a passphrase. Terminate. */
9317 free_prompts(s->cur_prompt);
9318 ssh_disconnect(ssh, NULL,
9319 "Unable to authenticate",
9320 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9325 dupstr(s->cur_prompt->prompts[0]->result);
9326 free_prompts(s->cur_prompt);
9328 passphrase = NULL; /* no passphrase needed */
9332 * Try decrypting the key.
9334 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9335 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9337 /* burn the evidence */
9338 smemclr(passphrase, strlen(passphrase));
9341 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9343 (key == SSH2_WRONG_PASSPHRASE)) {
9344 c_write_str(ssh, "Wrong passphrase\r\n");
9346 /* and loop again */
9348 c_write_str(ssh, "Unable to load private key (");
9349 c_write_str(ssh, error);
9350 c_write_str(ssh, ")\r\n");
9352 break; /* try something else */
9358 unsigned char *pkblob, *sigblob, *sigdata;
9359 int pkblob_len, sigblob_len, sigdata_len;
9363 * We have loaded the private key and the server
9364 * has announced that it's willing to accept it.
9365 * Hallelujah. Generate a signature and send it.
9367 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9368 ssh2_pkt_addstring(s->pktout, ssh->username);
9369 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9370 /* service requested */
9371 ssh2_pkt_addstring(s->pktout, "publickey");
9373 ssh2_pkt_addbool(s->pktout, TRUE);
9374 /* signature follows */
9375 ssh2_pkt_addstring(s->pktout, key->alg->name);
9376 pkblob = key->alg->public_blob(key->data,
9378 ssh2_pkt_addstring_start(s->pktout);
9379 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9383 * The data to be signed is:
9387 * followed by everything so far placed in the
9390 sigdata_len = s->pktout->length - 5 + 4 +
9391 ssh->v2_session_id_len;
9392 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9394 sigdata = snewn(sigdata_len, unsigned char);
9396 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9397 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9400 memcpy(sigdata+p, ssh->v2_session_id,
9401 ssh->v2_session_id_len);
9402 p += ssh->v2_session_id_len;
9403 memcpy(sigdata+p, s->pktout->data + 5,
9404 s->pktout->length - 5);
9405 p += s->pktout->length - 5;
9406 assert(p == sigdata_len);
9407 sigblob = key->alg->sign(key->data, (char *)sigdata,
9408 sigdata_len, &sigblob_len);
9409 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9410 sigblob, sigblob_len);
9415 ssh2_pkt_send(ssh, s->pktout);
9416 logevent("Sent public key signature");
9417 s->type = AUTH_TYPE_PUBLICKEY;
9418 key->alg->freekey(key->data);
9422 } else if (s->can_gssapi && !s->tried_gssapi) {
9424 /* GSSAPI Authentication */
9429 s->type = AUTH_TYPE_GSSAPI;
9430 s->tried_gssapi = TRUE;
9432 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9435 * Pick the highest GSS library on the preference
9441 for (i = 0; i < ngsslibs; i++) {
9442 int want_id = conf_get_int_int(ssh->conf,
9443 CONF_ssh_gsslist, i);
9444 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9445 if (ssh->gsslibs->libraries[j].id == want_id) {
9446 s->gsslib = &ssh->gsslibs->libraries[j];
9447 goto got_gsslib; /* double break */
9452 * We always expect to have found something in
9453 * the above loop: we only came here if there
9454 * was at least one viable GSS library, and the
9455 * preference list should always mention
9456 * everything and only change the order.
9461 if (s->gsslib->gsslogmsg)
9462 logevent(s->gsslib->gsslogmsg);
9464 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9465 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9466 ssh2_pkt_addstring(s->pktout, ssh->username);
9467 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9468 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9469 logevent("Attempting GSSAPI authentication");
9471 /* add mechanism info */
9472 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9474 /* number of GSSAPI mechanisms */
9475 ssh2_pkt_adduint32(s->pktout,1);
9477 /* length of OID + 2 */
9478 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9479 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9482 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9484 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9486 ssh2_pkt_send(ssh, s->pktout);
9487 crWaitUntilV(pktin);
9488 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9489 logevent("GSSAPI authentication request refused");
9493 /* check returned packet ... */
9495 ssh_pkt_getstring(pktin, &data, &len);
9496 s->gss_rcvtok.value = data;
9497 s->gss_rcvtok.length = len;
9498 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9499 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9500 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9501 memcmp((char *)s->gss_rcvtok.value + 2,
9502 s->gss_buf.value,s->gss_buf.length) ) {
9503 logevent("GSSAPI authentication - wrong response from server");
9507 /* now start running */
9508 s->gss_stat = s->gsslib->import_name(s->gsslib,
9511 if (s->gss_stat != SSH_GSS_OK) {
9512 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9513 logevent("GSSAPI import name failed - Bad service name");
9515 logevent("GSSAPI import name failed");
9519 /* fetch TGT into GSS engine */
9520 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9522 if (s->gss_stat != SSH_GSS_OK) {
9523 logevent("GSSAPI authentication failed to get credentials");
9524 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9528 /* initial tokens are empty */
9529 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9530 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9532 /* now enter the loop */
9534 s->gss_stat = s->gsslib->init_sec_context
9538 conf_get_int(ssh->conf, CONF_gssapifwd),
9542 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9543 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9544 logevent("GSSAPI authentication initialisation failed");
9546 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9547 &s->gss_buf) == SSH_GSS_OK) {
9548 logevent(s->gss_buf.value);
9549 sfree(s->gss_buf.value);
9554 logevent("GSSAPI authentication initialised");
9556 /* Client and server now exchange tokens until GSSAPI
9557 * no longer says CONTINUE_NEEDED */
9559 if (s->gss_sndtok.length != 0) {
9560 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9561 ssh_pkt_addstring_start(s->pktout);
9562 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9563 ssh2_pkt_send(ssh, s->pktout);
9564 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9567 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9568 crWaitUntilV(pktin);
9569 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9570 logevent("GSSAPI authentication - bad server response");
9571 s->gss_stat = SSH_GSS_FAILURE;
9574 ssh_pkt_getstring(pktin, &data, &len);
9575 s->gss_rcvtok.value = data;
9576 s->gss_rcvtok.length = len;
9578 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9580 if (s->gss_stat != SSH_GSS_OK) {
9581 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9582 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9585 logevent("GSSAPI authentication loop finished OK");
9587 /* Now send the MIC */
9589 s->pktout = ssh2_pkt_init(0);
9590 micoffset = s->pktout->length;
9591 ssh_pkt_addstring_start(s->pktout);
9592 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9593 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9594 ssh_pkt_addstring(s->pktout, ssh->username);
9595 ssh_pkt_addstring(s->pktout, "ssh-connection");
9596 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9598 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9599 s->gss_buf.length = s->pktout->length - micoffset;
9601 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9602 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9603 ssh_pkt_addstring_start(s->pktout);
9604 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9605 ssh2_pkt_send(ssh, s->pktout);
9606 s->gsslib->free_mic(s->gsslib, &mic);
9610 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9611 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9614 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9617 * Keyboard-interactive authentication.
9620 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9622 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9624 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9625 ssh2_pkt_addstring(s->pktout, ssh->username);
9626 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9627 /* service requested */
9628 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9630 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9631 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9632 ssh2_pkt_send(ssh, s->pktout);
9634 logevent("Attempting keyboard-interactive authentication");
9636 crWaitUntilV(pktin);
9637 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9638 /* Server is not willing to do keyboard-interactive
9639 * at all (or, bizarrely but legally, accepts the
9640 * user without actually issuing any prompts).
9641 * Give up on it entirely. */
9643 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9644 s->kbd_inter_refused = TRUE; /* don't try it again */
9649 * Loop while the server continues to send INFO_REQUESTs.
9651 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9653 char *name, *inst, *lang;
9654 int name_len, inst_len, lang_len;
9658 * We've got a fresh USERAUTH_INFO_REQUEST.
9659 * Get the preamble and start building a prompt.
9661 ssh_pkt_getstring(pktin, &name, &name_len);
9662 ssh_pkt_getstring(pktin, &inst, &inst_len);
9663 ssh_pkt_getstring(pktin, &lang, &lang_len);
9664 s->cur_prompt = new_prompts(ssh->frontend);
9665 s->cur_prompt->to_server = TRUE;
9668 * Get any prompt(s) from the packet.
9670 s->num_prompts = ssh_pkt_getuint32(pktin);
9671 for (i = 0; i < s->num_prompts; i++) {
9675 static char noprompt[] =
9676 "<server failed to send prompt>: ";
9678 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9679 echo = ssh2_pkt_getbool(pktin);
9682 prompt_len = lenof(noprompt)-1;
9684 add_prompt(s->cur_prompt,
9685 dupprintf("%.*s", prompt_len, prompt),
9690 /* FIXME: better prefix to distinguish from
9692 s->cur_prompt->name =
9693 dupprintf("SSH server: %.*s", name_len, name);
9694 s->cur_prompt->name_reqd = TRUE;
9696 s->cur_prompt->name =
9697 dupstr("SSH server authentication");
9698 s->cur_prompt->name_reqd = FALSE;
9700 /* We add a prefix to try to make it clear that a prompt
9701 * has come from the server.
9702 * FIXME: ugly to print "Using..." in prompt _every_
9703 * time round. Can this be done more subtly? */
9704 /* Special case: for reasons best known to themselves,
9705 * some servers send k-i requests with no prompts and
9706 * nothing to display. Keep quiet in this case. */
9707 if (s->num_prompts || name_len || inst_len) {
9708 s->cur_prompt->instruction =
9709 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9710 inst_len ? "\n" : "", inst_len, inst);
9711 s->cur_prompt->instr_reqd = TRUE;
9713 s->cur_prompt->instr_reqd = FALSE;
9717 * Display any instructions, and get the user's
9721 int ret; /* not live over crReturn */
9722 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9725 crWaitUntilV(!pktin);
9726 ret = get_userpass_input(s->cur_prompt, in, inlen);
9731 * Failed to get responses. Terminate.
9733 free_prompts(s->cur_prompt);
9734 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9735 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9742 * Send the response(s) to the server.
9744 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9745 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9746 for (i=0; i < s->num_prompts; i++) {
9747 ssh2_pkt_addstring(s->pktout,
9748 s->cur_prompt->prompts[i]->result);
9750 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9753 * Free the prompts structure from this iteration.
9754 * If there's another, a new one will be allocated
9755 * when we return to the top of this while loop.
9757 free_prompts(s->cur_prompt);
9760 * Get the next packet in case it's another
9763 crWaitUntilV(pktin);
9768 * We should have SUCCESS or FAILURE now.
9772 } else if (s->can_passwd) {
9775 * Plain old password authentication.
9777 int ret; /* not live over crReturn */
9778 int changereq_first_time; /* not live over crReturn */
9780 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9782 s->cur_prompt = new_prompts(ssh->frontend);
9783 s->cur_prompt->to_server = TRUE;
9784 s->cur_prompt->name = dupstr("SSH password");
9785 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9790 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9793 crWaitUntilV(!pktin);
9794 ret = get_userpass_input(s->cur_prompt, in, inlen);
9799 * Failed to get responses. Terminate.
9801 free_prompts(s->cur_prompt);
9802 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9803 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9808 * Squirrel away the password. (We may need it later if
9809 * asked to change it.)
9811 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9812 free_prompts(s->cur_prompt);
9815 * Send the password packet.
9817 * We pad out the password packet to 256 bytes to make
9818 * it harder for an attacker to find the length of the
9821 * Anyone using a password longer than 256 bytes
9822 * probably doesn't have much to worry about from
9823 * people who find out how long their password is!
9825 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9826 ssh2_pkt_addstring(s->pktout, ssh->username);
9827 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9828 /* service requested */
9829 ssh2_pkt_addstring(s->pktout, "password");
9830 ssh2_pkt_addbool(s->pktout, FALSE);
9831 ssh2_pkt_addstring(s->pktout, s->password);
9832 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9833 logevent("Sent password");
9834 s->type = AUTH_TYPE_PASSWORD;
9837 * Wait for next packet, in case it's a password change
9840 crWaitUntilV(pktin);
9841 changereq_first_time = TRUE;
9843 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9846 * We're being asked for a new password
9847 * (perhaps not for the first time).
9848 * Loop until the server accepts it.
9851 int got_new = FALSE; /* not live over crReturn */
9852 char *prompt; /* not live over crReturn */
9853 int prompt_len; /* not live over crReturn */
9857 if (changereq_first_time)
9858 msg = "Server requested password change";
9860 msg = "Server rejected new password";
9862 c_write_str(ssh, msg);
9863 c_write_str(ssh, "\r\n");
9866 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9868 s->cur_prompt = new_prompts(ssh->frontend);
9869 s->cur_prompt->to_server = TRUE;
9870 s->cur_prompt->name = dupstr("New SSH password");
9871 s->cur_prompt->instruction =
9872 dupprintf("%.*s", prompt_len, prompt);
9873 s->cur_prompt->instr_reqd = TRUE;
9875 * There's no explicit requirement in the protocol
9876 * for the "old" passwords in the original and
9877 * password-change messages to be the same, and
9878 * apparently some Cisco kit supports password change
9879 * by the user entering a blank password originally
9880 * and the real password subsequently, so,
9881 * reluctantly, we prompt for the old password again.
9883 * (On the other hand, some servers don't even bother
9884 * to check this field.)
9886 add_prompt(s->cur_prompt,
9887 dupstr("Current password (blank for previously entered password): "),
9889 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9891 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9895 * Loop until the user manages to enter the same
9900 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9903 crWaitUntilV(!pktin);
9904 ret = get_userpass_input(s->cur_prompt, in, inlen);
9909 * Failed to get responses. Terminate.
9911 /* burn the evidence */
9912 free_prompts(s->cur_prompt);
9913 smemclr(s->password, strlen(s->password));
9915 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9916 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9922 * If the user specified a new original password
9923 * (IYSWIM), overwrite any previously specified
9925 * (A side effect is that the user doesn't have to
9926 * re-enter it if they louse up the new password.)
9928 if (s->cur_prompt->prompts[0]->result[0]) {
9929 smemclr(s->password, strlen(s->password));
9930 /* burn the evidence */
9933 dupstr(s->cur_prompt->prompts[0]->result);
9937 * Check the two new passwords match.
9939 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9940 s->cur_prompt->prompts[2]->result)
9943 /* They don't. Silly user. */
9944 c_write_str(ssh, "Passwords do not match\r\n");
9949 * Send the new password (along with the old one).
9950 * (see above for padding rationale)
9952 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9953 ssh2_pkt_addstring(s->pktout, ssh->username);
9954 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9955 /* service requested */
9956 ssh2_pkt_addstring(s->pktout, "password");
9957 ssh2_pkt_addbool(s->pktout, TRUE);
9958 ssh2_pkt_addstring(s->pktout, s->password);
9959 ssh2_pkt_addstring(s->pktout,
9960 s->cur_prompt->prompts[1]->result);
9961 free_prompts(s->cur_prompt);
9962 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9963 logevent("Sent new password");
9966 * Now see what the server has to say about it.
9967 * (If it's CHANGEREQ again, it's not happy with the
9970 crWaitUntilV(pktin);
9971 changereq_first_time = FALSE;
9976 * We need to reexamine the current pktin at the top
9977 * of the loop. Either:
9978 * - we weren't asked to change password at all, in
9979 * which case it's a SUCCESS or FAILURE with the
9981 * - we sent a new password, and the server was
9982 * either OK with it (SUCCESS or FAILURE w/partial
9983 * success) or unhappy with the _old_ password
9984 * (FAILURE w/o partial success)
9985 * In any of these cases, we go back to the top of
9986 * the loop and start again.
9991 * We don't need the old password any more, in any
9992 * case. Burn the evidence.
9994 smemclr(s->password, strlen(s->password));
9998 char *str = dupprintf("No supported authentication methods available"
9999 " (server sent: %.*s)",
10002 ssh_disconnect(ssh, str,
10003 "No supported authentication methods available",
10004 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10014 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10016 /* Clear up various bits and pieces from authentication. */
10017 if (s->publickey_blob) {
10018 sfree(s->publickey_blob);
10019 sfree(s->publickey_comment);
10021 if (s->agent_response)
10022 sfree(s->agent_response);
10024 if (s->userauth_success && !ssh->bare_connection) {
10026 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10027 * packets since. Signal the transport layer to consider enacting
10028 * delayed compression.
10030 * (Relying on we_are_in is not sufficient, as
10031 * draft-miller-secsh-compression-delayed is quite clear that it
10032 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10033 * become set for other reasons.)
10035 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10038 ssh->channels = newtree234(ssh_channelcmp);
10041 * Set up handlers for some connection protocol messages, so we
10042 * don't have to handle them repeatedly in this coroutine.
10044 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10045 ssh2_msg_channel_window_adjust;
10046 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10047 ssh2_msg_global_request;
10050 * Create the main session channel.
10052 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10053 ssh->mainchan = NULL;
10055 ssh->mainchan = snew(struct ssh_channel);
10056 ssh->mainchan->ssh = ssh;
10057 ssh2_channel_init(ssh->mainchan);
10059 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10061 * Just start a direct-tcpip channel and use it as the main
10064 ssh_send_port_open(ssh->mainchan,
10065 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10066 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10068 ssh->ncmode = TRUE;
10070 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10071 logevent("Opening session as main channel");
10072 ssh2_pkt_send(ssh, s->pktout);
10073 ssh->ncmode = FALSE;
10075 crWaitUntilV(pktin);
10076 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10077 bombout(("Server refused to open channel"));
10079 /* FIXME: error data comes back in FAILURE packet */
10081 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10082 bombout(("Server's channel confirmation cited wrong channel"));
10085 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10086 ssh->mainchan->halfopen = FALSE;
10087 ssh->mainchan->type = CHAN_MAINSESSION;
10088 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10089 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10090 add234(ssh->channels, ssh->mainchan);
10091 update_specials_menu(ssh->frontend);
10092 logevent("Opened main channel");
10096 * Now we have a channel, make dispatch table entries for
10097 * general channel-based messages.
10099 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10100 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10101 ssh2_msg_channel_data;
10102 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10103 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10104 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10105 ssh2_msg_channel_open_confirmation;
10106 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10107 ssh2_msg_channel_open_failure;
10108 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10109 ssh2_msg_channel_request;
10110 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10111 ssh2_msg_channel_open;
10112 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10113 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10116 * Now the connection protocol is properly up and running, with
10117 * all those dispatch table entries, so it's safe to let
10118 * downstreams start trying to open extra channels through us.
10120 if (ssh->connshare)
10121 share_activate(ssh->connshare, ssh->v_s);
10123 if (ssh->mainchan && ssh_is_simple(ssh)) {
10125 * This message indicates to the server that we promise
10126 * not to try to run any other channel in parallel with
10127 * this one, so it's safe for it to advertise a very large
10128 * window and leave the flow control to TCP.
10130 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10131 "simple@putty.projects.tartarus.org",
10133 ssh2_pkt_send(ssh, s->pktout);
10137 * Enable port forwardings.
10139 ssh_setup_portfwd(ssh, ssh->conf);
10141 if (ssh->mainchan && !ssh->ncmode) {
10143 * Send the CHANNEL_REQUESTS for the main session channel.
10144 * Each one is handled by its own little asynchronous
10148 /* Potentially enable X11 forwarding. */
10149 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10151 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10153 if (!ssh->x11disp) {
10154 /* FIXME: return an error message from x11_setup_display */
10155 logevent("X11 forwarding not enabled: unable to"
10156 " initialise X display");
10158 ssh->x11auth = x11_invent_fake_auth
10159 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10160 ssh->x11auth->disp = ssh->x11disp;
10162 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10166 /* Potentially enable agent forwarding. */
10167 if (ssh_agent_forwarding_permitted(ssh))
10168 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10170 /* Now allocate a pty for the session. */
10171 if (!conf_get_int(ssh->conf, CONF_nopty))
10172 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10174 /* Send environment variables. */
10175 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10178 * Start a shell or a remote command. We may have to attempt
10179 * this twice if the config data has provided a second choice
10186 if (ssh->fallback_cmd) {
10187 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10188 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10190 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10191 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10195 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10196 ssh2_response_authconn, NULL);
10197 ssh2_pkt_addstring(s->pktout, cmd);
10199 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10200 ssh2_response_authconn, NULL);
10201 ssh2_pkt_addstring(s->pktout, cmd);
10203 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10204 ssh2_response_authconn, NULL);
10206 ssh2_pkt_send(ssh, s->pktout);
10208 crWaitUntilV(pktin);
10210 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10211 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10212 bombout(("Unexpected response to shell/command request:"
10213 " packet type %d", pktin->type));
10217 * We failed to start the command. If this is the
10218 * fallback command, we really are finished; if it's
10219 * not, and if the fallback command exists, try falling
10220 * back to it before complaining.
10222 if (!ssh->fallback_cmd &&
10223 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10224 logevent("Primary command failed; attempting fallback");
10225 ssh->fallback_cmd = TRUE;
10228 bombout(("Server refused to start a shell/command"));
10231 logevent("Started a shell/command");
10236 ssh->editing = ssh->echoing = TRUE;
10239 ssh->state = SSH_STATE_SESSION;
10240 if (ssh->size_needed)
10241 ssh_size(ssh, ssh->term_width, ssh->term_height);
10242 if (ssh->eof_needed)
10243 ssh_special(ssh, TS_EOF);
10249 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10254 s->try_send = FALSE;
10258 * _All_ the connection-layer packets we expect to
10259 * receive are now handled by the dispatch table.
10260 * Anything that reaches here must be bogus.
10263 bombout(("Strange packet received: type %d", pktin->type));
10265 } else if (ssh->mainchan) {
10267 * We have spare data. Add it to the channel buffer.
10269 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10270 s->try_send = TRUE;
10274 struct ssh_channel *c;
10276 * Try to send data on all channels if we can.
10278 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10279 ssh2_try_send_and_unthrottle(ssh, c);
10287 * Handlers for SSH-2 messages that might arrive at any moment.
10289 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10291 /* log reason code in disconnect message */
10293 int reason, msglen;
10295 reason = ssh_pkt_getuint32(pktin);
10296 ssh_pkt_getstring(pktin, &msg, &msglen);
10298 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10299 buf = dupprintf("Received disconnect message (%s)",
10300 ssh2_disconnect_reasons[reason]);
10302 buf = dupprintf("Received disconnect message (unknown"
10303 " type %d)", reason);
10307 buf = dupprintf("Disconnection message text: %.*s",
10310 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10312 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10313 ssh2_disconnect_reasons[reason] : "unknown",
10318 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10320 /* log the debug message */
10324 /* XXX maybe we should actually take notice of the return value */
10325 ssh2_pkt_getbool(pktin);
10326 ssh_pkt_getstring(pktin, &msg, &msglen);
10328 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10331 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10333 do_ssh2_transport(ssh, NULL, 0, pktin);
10337 * Called if we receive a packet that isn't allowed by the protocol.
10338 * This only applies to packets whose meaning PuTTY understands.
10339 * Entirely unknown packets are handled below.
10341 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10343 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10344 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10346 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10350 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10352 struct Packet *pktout;
10353 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10354 ssh2_pkt_adduint32(pktout, pktin->sequence);
10356 * UNIMPLEMENTED messages MUST appear in the same order as the
10357 * messages they respond to. Hence, never queue them.
10359 ssh2_pkt_send_noqueue(ssh, pktout);
10363 * Handle the top-level SSH-2 protocol.
10365 static void ssh2_protocol_setup(Ssh ssh)
10370 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10372 for (i = 0; i < 256; i++)
10373 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10376 * Initially, we only accept transport messages (and a few generic
10377 * ones). do_ssh2_authconn will add more when it starts.
10378 * Messages that are understood but not currently acceptable go to
10379 * ssh2_msg_unexpected.
10381 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10382 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10383 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10384 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10385 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10386 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10387 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10388 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10389 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10390 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10391 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10392 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10393 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10394 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10395 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10396 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10397 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10398 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10399 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10400 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10401 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10402 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10403 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10404 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10405 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10406 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10407 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10408 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10409 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10410 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10411 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10412 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10413 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10416 * These messages have a special handler from the start.
10418 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10419 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10420 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10423 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10428 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10430 for (i = 0; i < 256; i++)
10431 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10434 * Initially, we set all ssh-connection messages to 'unexpected';
10435 * do_ssh2_authconn will fill things in properly. We also handle a
10436 * couple of messages from the transport protocol which aren't
10437 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10440 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10441 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10442 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10444 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10445 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10446 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10448 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10450 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10451 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10452 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10453 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10455 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10458 * These messages have a special handler from the start.
10460 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10461 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10462 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10465 static void ssh2_timer(void *ctx, unsigned long now)
10467 Ssh ssh = (Ssh)ctx;
10469 if (ssh->state == SSH_STATE_CLOSED)
10472 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10473 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10474 now == ssh->next_rekey) {
10475 do_ssh2_transport(ssh, "timeout", -1, NULL);
10479 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10480 struct Packet *pktin)
10482 unsigned char *in = (unsigned char *)vin;
10483 if (ssh->state == SSH_STATE_CLOSED)
10487 ssh->incoming_data_size += pktin->encrypted_len;
10488 if (!ssh->kex_in_progress &&
10489 ssh->max_data_size != 0 &&
10490 ssh->incoming_data_size > ssh->max_data_size)
10491 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10495 ssh->packet_dispatch[pktin->type](ssh, pktin);
10496 else if (!ssh->protocol_initial_phase_done)
10497 do_ssh2_transport(ssh, in, inlen, pktin);
10499 do_ssh2_authconn(ssh, in, inlen, pktin);
10502 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10503 struct Packet *pktin)
10505 unsigned char *in = (unsigned char *)vin;
10506 if (ssh->state == SSH_STATE_CLOSED)
10510 ssh->packet_dispatch[pktin->type](ssh, pktin);
10512 do_ssh2_authconn(ssh, in, inlen, pktin);
10515 static void ssh_cache_conf_values(Ssh ssh)
10517 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10521 * Called to set up the connection.
10523 * Returns an error message, or NULL on success.
10525 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10526 Conf *conf, char *host, int port, char **realhost,
10527 int nodelay, int keepalive)
10532 ssh = snew(struct ssh_tag);
10533 ssh->conf = conf_copy(conf);
10534 ssh_cache_conf_values(ssh);
10535 ssh->version = 0; /* when not ready yet */
10537 ssh->cipher = NULL;
10538 ssh->v1_cipher_ctx = NULL;
10539 ssh->crcda_ctx = NULL;
10540 ssh->cscipher = NULL;
10541 ssh->cs_cipher_ctx = NULL;
10542 ssh->sccipher = NULL;
10543 ssh->sc_cipher_ctx = NULL;
10545 ssh->cs_mac_ctx = NULL;
10547 ssh->sc_mac_ctx = NULL;
10548 ssh->cscomp = NULL;
10549 ssh->cs_comp_ctx = NULL;
10550 ssh->sccomp = NULL;
10551 ssh->sc_comp_ctx = NULL;
10553 ssh->kex_ctx = NULL;
10554 ssh->hostkey = NULL;
10555 ssh->hostkey_str = NULL;
10556 ssh->exitcode = -1;
10557 ssh->close_expected = FALSE;
10558 ssh->clean_exit = FALSE;
10559 ssh->state = SSH_STATE_PREPACKET;
10560 ssh->size_needed = FALSE;
10561 ssh->eof_needed = FALSE;
10563 ssh->logctx = NULL;
10564 ssh->deferred_send_data = NULL;
10565 ssh->deferred_len = 0;
10566 ssh->deferred_size = 0;
10567 ssh->fallback_cmd = 0;
10568 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10569 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10570 ssh->x11disp = NULL;
10571 ssh->x11auth = NULL;
10572 ssh->x11authtree = newtree234(x11_authcmp);
10573 ssh->v1_compressing = FALSE;
10574 ssh->v2_outgoing_sequence = 0;
10575 ssh->ssh1_rdpkt_crstate = 0;
10576 ssh->ssh2_rdpkt_crstate = 0;
10577 ssh->ssh2_bare_rdpkt_crstate = 0;
10578 ssh->ssh_gotdata_crstate = 0;
10579 ssh->do_ssh1_connection_crstate = 0;
10580 ssh->do_ssh_init_state = NULL;
10581 ssh->do_ssh_connection_init_state = NULL;
10582 ssh->do_ssh1_login_state = NULL;
10583 ssh->do_ssh2_transport_state = NULL;
10584 ssh->do_ssh2_authconn_state = NULL;
10587 ssh->mainchan = NULL;
10588 ssh->throttled_all = 0;
10589 ssh->v1_stdout_throttling = 0;
10591 ssh->queuelen = ssh->queuesize = 0;
10592 ssh->queueing = FALSE;
10593 ssh->qhead = ssh->qtail = NULL;
10594 ssh->deferred_rekey_reason = NULL;
10595 bufchain_init(&ssh->queued_incoming_data);
10596 ssh->frozen = FALSE;
10597 ssh->username = NULL;
10598 ssh->sent_console_eof = FALSE;
10599 ssh->got_pty = FALSE;
10600 ssh->bare_connection = FALSE;
10601 ssh->X11_fwd_enabled = FALSE;
10602 ssh->connshare = NULL;
10603 ssh->attempting_connshare = FALSE;
10605 *backend_handle = ssh;
10608 if (crypto_startup() == 0)
10609 return "Microsoft high encryption pack not installed!";
10612 ssh->frontend = frontend_handle;
10613 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10614 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10616 ssh->channels = NULL;
10617 ssh->rportfwds = NULL;
10618 ssh->portfwds = NULL;
10623 ssh->conn_throttle_count = 0;
10624 ssh->overall_bufsize = 0;
10625 ssh->fallback_cmd = 0;
10627 ssh->protocol = NULL;
10629 ssh->protocol_initial_phase_done = FALSE;
10631 ssh->pinger = NULL;
10633 ssh->incoming_data_size = ssh->outgoing_data_size =
10634 ssh->deferred_data_size = 0L;
10635 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10636 CONF_ssh_rekey_data));
10637 ssh->kex_in_progress = FALSE;
10640 ssh->gsslibs = NULL;
10643 random_ref(); /* do this now - may be needed by sharing setup code */
10645 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10654 static void ssh_free(void *handle)
10656 Ssh ssh = (Ssh) handle;
10657 struct ssh_channel *c;
10658 struct ssh_rportfwd *pf;
10659 struct X11FakeAuth *auth;
10661 if (ssh->v1_cipher_ctx)
10662 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10663 if (ssh->cs_cipher_ctx)
10664 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10665 if (ssh->sc_cipher_ctx)
10666 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10667 if (ssh->cs_mac_ctx)
10668 ssh->csmac->free_context(ssh->cs_mac_ctx);
10669 if (ssh->sc_mac_ctx)
10670 ssh->scmac->free_context(ssh->sc_mac_ctx);
10671 if (ssh->cs_comp_ctx) {
10673 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10675 zlib_compress_cleanup(ssh->cs_comp_ctx);
10677 if (ssh->sc_comp_ctx) {
10679 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10681 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10684 dh_cleanup(ssh->kex_ctx);
10685 sfree(ssh->savedhost);
10687 while (ssh->queuelen-- > 0)
10688 ssh_free_packet(ssh->queue[ssh->queuelen]);
10691 while (ssh->qhead) {
10692 struct queued_handler *qh = ssh->qhead;
10693 ssh->qhead = qh->next;
10696 ssh->qhead = ssh->qtail = NULL;
10698 if (ssh->channels) {
10699 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10702 if (c->u.x11.xconn != NULL)
10703 x11_close(c->u.x11.xconn);
10705 case CHAN_SOCKDATA:
10706 case CHAN_SOCKDATA_DORMANT:
10707 if (c->u.pfd.pf != NULL)
10708 pfd_close(c->u.pfd.pf);
10711 if (ssh->version == 2) {
10712 struct outstanding_channel_request *ocr, *nocr;
10713 ocr = c->v.v2.chanreq_head;
10715 ocr->handler(c, NULL, ocr->ctx);
10720 bufchain_clear(&c->v.v2.outbuffer);
10724 freetree234(ssh->channels);
10725 ssh->channels = NULL;
10728 if (ssh->connshare)
10729 sharestate_free(ssh->connshare);
10731 if (ssh->rportfwds) {
10732 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10734 freetree234(ssh->rportfwds);
10735 ssh->rportfwds = NULL;
10737 sfree(ssh->deferred_send_data);
10739 x11_free_display(ssh->x11disp);
10740 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10741 x11_free_fake_auth(auth);
10742 freetree234(ssh->x11authtree);
10743 sfree(ssh->do_ssh_init_state);
10744 sfree(ssh->do_ssh1_login_state);
10745 sfree(ssh->do_ssh2_transport_state);
10746 sfree(ssh->do_ssh2_authconn_state);
10749 sfree(ssh->fullhostname);
10750 sfree(ssh->hostkey_str);
10751 if (ssh->crcda_ctx) {
10752 crcda_free_context(ssh->crcda_ctx);
10753 ssh->crcda_ctx = NULL;
10756 ssh_do_close(ssh, TRUE);
10757 expire_timer_context(ssh);
10759 pinger_free(ssh->pinger);
10760 bufchain_clear(&ssh->queued_incoming_data);
10761 sfree(ssh->username);
10762 conf_free(ssh->conf);
10765 ssh_gss_cleanup(ssh->gsslibs);
10773 * Reconfigure the SSH backend.
10775 static void ssh_reconfig(void *handle, Conf *conf)
10777 Ssh ssh = (Ssh) handle;
10778 char *rekeying = NULL, rekey_mandatory = FALSE;
10779 unsigned long old_max_data_size;
10782 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10784 ssh_setup_portfwd(ssh, conf);
10786 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10787 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10789 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10790 unsigned long now = GETTICKCOUNT();
10792 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10793 rekeying = "timeout shortened";
10795 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10799 old_max_data_size = ssh->max_data_size;
10800 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10801 CONF_ssh_rekey_data));
10802 if (old_max_data_size != ssh->max_data_size &&
10803 ssh->max_data_size != 0) {
10804 if (ssh->outgoing_data_size > ssh->max_data_size ||
10805 ssh->incoming_data_size > ssh->max_data_size)
10806 rekeying = "data limit lowered";
10809 if (conf_get_int(ssh->conf, CONF_compression) !=
10810 conf_get_int(conf, CONF_compression)) {
10811 rekeying = "compression setting changed";
10812 rekey_mandatory = TRUE;
10815 for (i = 0; i < CIPHER_MAX; i++)
10816 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10817 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10818 rekeying = "cipher settings changed";
10819 rekey_mandatory = TRUE;
10821 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10822 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10823 rekeying = "cipher settings changed";
10824 rekey_mandatory = TRUE;
10827 conf_free(ssh->conf);
10828 ssh->conf = conf_copy(conf);
10829 ssh_cache_conf_values(ssh);
10831 if (!ssh->bare_connection && rekeying) {
10832 if (!ssh->kex_in_progress) {
10833 do_ssh2_transport(ssh, rekeying, -1, NULL);
10834 } else if (rekey_mandatory) {
10835 ssh->deferred_rekey_reason = rekeying;
10841 * Called to send data down the SSH connection.
10843 static int ssh_send(void *handle, char *buf, int len)
10845 Ssh ssh = (Ssh) handle;
10847 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10850 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10852 return ssh_sendbuffer(ssh);
10856 * Called to query the current amount of buffered stdin data.
10858 static int ssh_sendbuffer(void *handle)
10860 Ssh ssh = (Ssh) handle;
10861 int override_value;
10863 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10867 * If the SSH socket itself has backed up, add the total backup
10868 * size on that to any individual buffer on the stdin channel.
10870 override_value = 0;
10871 if (ssh->throttled_all)
10872 override_value = ssh->overall_bufsize;
10874 if (ssh->version == 1) {
10875 return override_value;
10876 } else if (ssh->version == 2) {
10877 if (!ssh->mainchan)
10878 return override_value;
10880 return (override_value +
10881 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10888 * Called to set the size of the window from SSH's POV.
10890 static void ssh_size(void *handle, int width, int height)
10892 Ssh ssh = (Ssh) handle;
10893 struct Packet *pktout;
10895 ssh->term_width = width;
10896 ssh->term_height = height;
10898 switch (ssh->state) {
10899 case SSH_STATE_BEFORE_SIZE:
10900 case SSH_STATE_PREPACKET:
10901 case SSH_STATE_CLOSED:
10902 break; /* do nothing */
10903 case SSH_STATE_INTERMED:
10904 ssh->size_needed = TRUE; /* buffer for later */
10906 case SSH_STATE_SESSION:
10907 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10908 if (ssh->version == 1) {
10909 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10910 PKT_INT, ssh->term_height,
10911 PKT_INT, ssh->term_width,
10912 PKT_INT, 0, PKT_INT, 0, PKT_END);
10913 } else if (ssh->mainchan) {
10914 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10916 ssh2_pkt_adduint32(pktout, ssh->term_width);
10917 ssh2_pkt_adduint32(pktout, ssh->term_height);
10918 ssh2_pkt_adduint32(pktout, 0);
10919 ssh2_pkt_adduint32(pktout, 0);
10920 ssh2_pkt_send(ssh, pktout);
10928 * Return a list of the special codes that make sense in this
10931 static const struct telnet_special *ssh_get_specials(void *handle)
10933 static const struct telnet_special ssh1_ignore_special[] = {
10934 {"IGNORE message", TS_NOP}
10936 static const struct telnet_special ssh2_ignore_special[] = {
10937 {"IGNORE message", TS_NOP},
10939 static const struct telnet_special ssh2_rekey_special[] = {
10940 {"Repeat key exchange", TS_REKEY},
10942 static const struct telnet_special ssh2_session_specials[] = {
10945 /* These are the signal names defined by RFC 4254.
10946 * They include all the ISO C signals, but are a subset of the POSIX
10947 * required signals. */
10948 {"SIGINT (Interrupt)", TS_SIGINT},
10949 {"SIGTERM (Terminate)", TS_SIGTERM},
10950 {"SIGKILL (Kill)", TS_SIGKILL},
10951 {"SIGQUIT (Quit)", TS_SIGQUIT},
10952 {"SIGHUP (Hangup)", TS_SIGHUP},
10953 {"More signals", TS_SUBMENU},
10954 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10955 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10956 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10957 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10958 {NULL, TS_EXITMENU}
10960 static const struct telnet_special specials_end[] = {
10961 {NULL, TS_EXITMENU}
10963 /* XXX review this length for any changes: */
10964 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10965 lenof(ssh2_rekey_special) +
10966 lenof(ssh2_session_specials) +
10967 lenof(specials_end)];
10968 Ssh ssh = (Ssh) handle;
10970 #define ADD_SPECIALS(name) \
10972 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10973 memcpy(&ssh_specials[i], name, sizeof name); \
10974 i += lenof(name); \
10977 if (ssh->version == 1) {
10978 /* Don't bother offering IGNORE if we've decided the remote
10979 * won't cope with it, since we wouldn't bother sending it if
10981 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10982 ADD_SPECIALS(ssh1_ignore_special);
10983 } else if (ssh->version == 2) {
10984 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10985 ADD_SPECIALS(ssh2_ignore_special);
10986 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10987 ADD_SPECIALS(ssh2_rekey_special);
10989 ADD_SPECIALS(ssh2_session_specials);
10990 } /* else we're not ready yet */
10993 ADD_SPECIALS(specials_end);
10994 return ssh_specials;
10998 #undef ADD_SPECIALS
11002 * Send special codes. TS_EOF is useful for `plink', so you
11003 * can send an EOF and collect resulting output (e.g. `plink
11006 static void ssh_special(void *handle, Telnet_Special code)
11008 Ssh ssh = (Ssh) handle;
11009 struct Packet *pktout;
11011 if (code == TS_EOF) {
11012 if (ssh->state != SSH_STATE_SESSION) {
11014 * Buffer the EOF in case we are pre-SESSION, so we can
11015 * send it as soon as we reach SESSION.
11017 if (code == TS_EOF)
11018 ssh->eof_needed = TRUE;
11021 if (ssh->version == 1) {
11022 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11023 } else if (ssh->mainchan) {
11024 sshfwd_write_eof(ssh->mainchan);
11025 ssh->send_ok = 0; /* now stop trying to read from stdin */
11027 logevent("Sent EOF message");
11028 } else if (code == TS_PING || code == TS_NOP) {
11029 if (ssh->state == SSH_STATE_CLOSED
11030 || ssh->state == SSH_STATE_PREPACKET) return;
11031 if (ssh->version == 1) {
11032 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11033 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11035 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11036 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11037 ssh2_pkt_addstring_start(pktout);
11038 ssh2_pkt_send_noqueue(ssh, pktout);
11041 } else if (code == TS_REKEY) {
11042 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11043 ssh->version == 2) {
11044 do_ssh2_transport(ssh, "at user request", -1, NULL);
11046 } else if (code == TS_BRK) {
11047 if (ssh->state == SSH_STATE_CLOSED
11048 || ssh->state == SSH_STATE_PREPACKET) return;
11049 if (ssh->version == 1) {
11050 logevent("Unable to send BREAK signal in SSH-1");
11051 } else if (ssh->mainchan) {
11052 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11053 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11054 ssh2_pkt_send(ssh, pktout);
11057 /* Is is a POSIX signal? */
11058 char *signame = NULL;
11059 if (code == TS_SIGABRT) signame = "ABRT";
11060 if (code == TS_SIGALRM) signame = "ALRM";
11061 if (code == TS_SIGFPE) signame = "FPE";
11062 if (code == TS_SIGHUP) signame = "HUP";
11063 if (code == TS_SIGILL) signame = "ILL";
11064 if (code == TS_SIGINT) signame = "INT";
11065 if (code == TS_SIGKILL) signame = "KILL";
11066 if (code == TS_SIGPIPE) signame = "PIPE";
11067 if (code == TS_SIGQUIT) signame = "QUIT";
11068 if (code == TS_SIGSEGV) signame = "SEGV";
11069 if (code == TS_SIGTERM) signame = "TERM";
11070 if (code == TS_SIGUSR1) signame = "USR1";
11071 if (code == TS_SIGUSR2) signame = "USR2";
11072 /* The SSH-2 protocol does in principle support arbitrary named
11073 * signals, including signame@domain, but we don't support those. */
11075 /* It's a signal. */
11076 if (ssh->version == 2 && ssh->mainchan) {
11077 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11078 ssh2_pkt_addstring(pktout, signame);
11079 ssh2_pkt_send(ssh, pktout);
11080 logeventf(ssh, "Sent signal SIG%s", signame);
11083 /* Never heard of it. Do nothing */
11088 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11090 Ssh ssh = (Ssh) handle;
11091 struct ssh_channel *c;
11092 c = snew(struct ssh_channel);
11095 ssh2_channel_init(c);
11096 c->halfopen = TRUE;
11097 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11099 add234(ssh->channels, c);
11103 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11105 struct ssh_channel *c;
11106 c = snew(struct ssh_channel);
11109 ssh2_channel_init(c);
11110 c->type = CHAN_SHARING;
11111 c->u.sharing.ctx = sharing_ctx;
11112 add234(ssh->channels, c);
11116 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11118 struct ssh_channel *c;
11120 c = find234(ssh->channels, &localid, ssh_channelfind);
11122 ssh_channel_destroy(c);
11125 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11126 const void *data, int datalen,
11127 const char *additional_log_text)
11129 struct Packet *pkt;
11131 pkt = ssh2_pkt_init(type);
11132 pkt->downstream_id = id;
11133 pkt->additional_log_text = additional_log_text;
11134 ssh2_pkt_adddata(pkt, data, datalen);
11135 ssh2_pkt_send(ssh, pkt);
11139 * This is called when stdout/stderr (the entity to which
11140 * from_backend sends data) manages to clear some backlog.
11142 static void ssh_unthrottle(void *handle, int bufsize)
11144 Ssh ssh = (Ssh) handle;
11147 if (ssh->version == 1) {
11148 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11149 ssh->v1_stdout_throttling = 0;
11150 ssh_throttle_conn(ssh, -1);
11153 if (ssh->mainchan) {
11154 ssh2_set_window(ssh->mainchan,
11155 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11156 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11157 if (ssh_is_simple(ssh))
11160 buflimit = ssh->mainchan->v.v2.locmaxwin;
11161 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11162 ssh->mainchan->throttling_conn = 0;
11163 ssh_throttle_conn(ssh, -1);
11169 * Now process any SSH connection data that was stashed in our
11170 * queue while we were frozen.
11172 ssh_process_queued_incoming_data(ssh);
11175 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11177 struct ssh_channel *c = (struct ssh_channel *)channel;
11179 struct Packet *pktout;
11181 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11183 if (ssh->version == 1) {
11184 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11185 PKT_INT, c->localid,
11188 /* PKT_STR, <org:orgport>, */
11191 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11193 char *trimmed_host = host_strduptrim(hostname);
11194 ssh2_pkt_addstring(pktout, trimmed_host);
11195 sfree(trimmed_host);
11197 ssh2_pkt_adduint32(pktout, port);
11199 * We make up values for the originator data; partly it's
11200 * too much hassle to keep track, and partly I'm not
11201 * convinced the server should be told details like that
11202 * about my local network configuration.
11203 * The "originator IP address" is syntactically a numeric
11204 * IP address, and some servers (e.g., Tectia) get upset
11205 * if it doesn't match this syntax.
11207 ssh2_pkt_addstring(pktout, "0.0.0.0");
11208 ssh2_pkt_adduint32(pktout, 0);
11209 ssh2_pkt_send(ssh, pktout);
11213 static int ssh_connected(void *handle)
11215 Ssh ssh = (Ssh) handle;
11216 return ssh->s != NULL;
11219 static int ssh_sendok(void *handle)
11221 Ssh ssh = (Ssh) handle;
11222 return ssh->send_ok;
11225 static int ssh_ldisc(void *handle, int option)
11227 Ssh ssh = (Ssh) handle;
11228 if (option == LD_ECHO)
11229 return ssh->echoing;
11230 if (option == LD_EDIT)
11231 return ssh->editing;
11235 static void ssh_provide_ldisc(void *handle, void *ldisc)
11237 Ssh ssh = (Ssh) handle;
11238 ssh->ldisc = ldisc;
11241 static void ssh_provide_logctx(void *handle, void *logctx)
11243 Ssh ssh = (Ssh) handle;
11244 ssh->logctx = logctx;
11247 static int ssh_return_exitcode(void *handle)
11249 Ssh ssh = (Ssh) handle;
11250 if (ssh->s != NULL)
11253 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11257 * cfg_info for SSH is the protocol running in this session.
11258 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11259 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11261 static int ssh_cfg_info(void *handle)
11263 Ssh ssh = (Ssh) handle;
11264 if (ssh->version == 0)
11265 return 0; /* don't know yet */
11266 else if (ssh->bare_connection)
11269 return ssh->version;
11273 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11274 * that fails. This variable is the means by which scp.c can reach
11275 * into the SSH code and find out which one it got.
11277 extern int ssh_fallback_cmd(void *handle)
11279 Ssh ssh = (Ssh) handle;
11280 return ssh->fallback_cmd;
11283 Backend ssh_backend = {
11293 ssh_return_exitcode,
11297 ssh_provide_logctx,