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) ||
2821 wc_match("dropbear_0.[2-4][0-9]*", imp) ||
2822 wc_match("dropbear_0.5[01]*", imp)))) {
2824 * These versions have the SSH-2 channel request bug.
2825 * OpenSSH 6.7 and above do not:
2826 * https://bugzilla.mindrot.org/show_bug.cgi?id=1818
2827 * dropbear_0.52 and above do not:
2828 * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c
2830 ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY;
2831 logevent("We believe remote version has SSH-2 channel request bug");
2836 * The `software version' part of an SSH version string is required
2837 * to contain no spaces or minus signs.
2839 static void ssh_fix_verstring(char *str)
2841 /* Eat "<protoversion>-". */
2842 while (*str && *str != '-') str++;
2843 assert(*str == '-'); str++;
2845 /* Convert minus signs and spaces in the remaining string into
2848 if (*str == '-' || *str == ' ')
2855 * Send an appropriate SSH version string.
2857 static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers)
2861 if (ssh->version == 2) {
2863 * Construct a v2 version string.
2865 verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver);
2868 * Construct a v1 version string.
2870 assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */
2871 verstring = dupprintf("SSH-%s-%s\012",
2872 (ssh_versioncmp(svers, "1.5") <= 0 ?
2877 ssh_fix_verstring(verstring + strlen(protoname));
2879 if (ssh->version == 2) {
2882 * Record our version string.
2884 len = strcspn(verstring, "\015\012");
2885 ssh->v_c = snewn(len + 1, char);
2886 memcpy(ssh->v_c, verstring, len);
2890 logeventf(ssh, "We claim version: %.*s",
2891 strcspn(verstring, "\015\012"), verstring);
2892 s_write(ssh, verstring, strlen(verstring));
2896 static int do_ssh_init(Ssh ssh, unsigned char c)
2898 static const char protoname[] = "SSH-";
2900 struct do_ssh_init_state {
2909 crState(do_ssh_init_state);
2913 /* Search for a line beginning with the protocol name prefix in
2916 for (s->i = 0; protoname[s->i]; s->i++) {
2917 if ((char)c != protoname[s->i]) goto no;
2927 s->vstrsize = sizeof(protoname) + 16;
2928 s->vstring = snewn(s->vstrsize, char);
2929 strcpy(s->vstring, protoname);
2930 s->vslen = strlen(protoname);
2933 if (s->vslen >= s->vstrsize - 1) {
2935 s->vstring = sresize(s->vstring, s->vstrsize, char);
2937 s->vstring[s->vslen++] = c;
2940 s->version[s->i] = '\0';
2942 } else if (s->i < sizeof(s->version) - 1)
2943 s->version[s->i++] = c;
2944 } else if (c == '\012')
2946 crReturn(1); /* get another char */
2949 ssh->agentfwd_enabled = FALSE;
2950 ssh->rdpkt2_state.incoming_sequence = 0;
2952 s->vstring[s->vslen] = 0;
2953 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2954 logeventf(ssh, "Server version: %s", s->vstring);
2955 ssh_detect_bugs(ssh, s->vstring);
2958 * Decide which SSH protocol version to support.
2961 /* Anything strictly below "2.0" means protocol 1 is supported. */
2962 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2963 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2964 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2966 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2967 bombout(("SSH protocol version 1 required by configuration but "
2968 "not provided by server"));
2971 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2972 bombout(("SSH protocol version 2 required by configuration but "
2973 "not provided by server"));
2977 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2982 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2984 /* Send the version string, if we haven't already */
2985 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2986 ssh_send_verstring(ssh, protoname, s->version);
2988 if (ssh->version == 2) {
2991 * Record their version string.
2993 len = strcspn(s->vstring, "\015\012");
2994 ssh->v_s = snewn(len + 1, char);
2995 memcpy(ssh->v_s, s->vstring, len);
2999 * Initialise SSH-2 protocol.
3001 ssh->protocol = ssh2_protocol;
3002 ssh2_protocol_setup(ssh);
3003 ssh->s_rdpkt = ssh2_rdpkt;
3006 * Initialise SSH-1 protocol.
3008 ssh->protocol = ssh1_protocol;
3009 ssh1_protocol_setup(ssh);
3010 ssh->s_rdpkt = ssh1_rdpkt;
3012 if (ssh->version == 2)
3013 do_ssh2_transport(ssh, NULL, -1, NULL);
3015 update_specials_menu(ssh->frontend);
3016 ssh->state = SSH_STATE_BEFORE_SIZE;
3017 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3024 static int do_ssh_connection_init(Ssh ssh, unsigned char c)
3027 * Ordinary SSH begins with the banner "SSH-x.y-...". This is just
3028 * the ssh-connection part, extracted and given a trivial binary
3029 * packet protocol, so we replace 'SSH-' at the start with a new
3030 * name. In proper SSH style (though of course this part of the
3031 * proper SSH protocol _isn't_ subject to this kind of
3032 * DNS-domain-based extension), we define the new name in our
3035 static const char protoname[] =
3036 "SSHCONNECTION@putty.projects.tartarus.org-";
3038 struct do_ssh_connection_init_state {
3046 crState(do_ssh_connection_init_state);
3050 /* Search for a line beginning with the protocol name prefix in
3053 for (s->i = 0; protoname[s->i]; s->i++) {
3054 if ((char)c != protoname[s->i]) goto no;
3064 s->vstrsize = sizeof(protoname) + 16;
3065 s->vstring = snewn(s->vstrsize, char);
3066 strcpy(s->vstring, protoname);
3067 s->vslen = strlen(protoname);
3070 if (s->vslen >= s->vstrsize - 1) {
3072 s->vstring = sresize(s->vstring, s->vstrsize, char);
3074 s->vstring[s->vslen++] = c;
3077 s->version[s->i] = '\0';
3079 } else if (s->i < sizeof(s->version) - 1)
3080 s->version[s->i++] = c;
3081 } else if (c == '\012')
3083 crReturn(1); /* get another char */
3086 ssh->agentfwd_enabled = FALSE;
3087 ssh->rdpkt2_bare_state.incoming_sequence = 0;
3089 s->vstring[s->vslen] = 0;
3090 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
3091 logeventf(ssh, "Server version: %s", s->vstring);
3092 ssh_detect_bugs(ssh, s->vstring);
3095 * Decide which SSH protocol version to support. This is easy in
3096 * bare ssh-connection mode: only 2.0 is legal.
3098 if (ssh_versioncmp(s->version, "2.0") < 0) {
3099 bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol"));
3102 if (conf_get_int(ssh->conf, CONF_sshprot) == 0) {
3103 bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode"));
3109 logeventf(ssh, "Using bare ssh-connection protocol");
3111 /* Send the version string, if we haven't already */
3112 ssh_send_verstring(ssh, protoname, s->version);
3115 * Initialise bare connection protocol.
3117 ssh->protocol = ssh2_bare_connection_protocol;
3118 ssh2_bare_connection_protocol_setup(ssh);
3119 ssh->s_rdpkt = ssh2_bare_connection_rdpkt;
3121 update_specials_menu(ssh->frontend);
3122 ssh->state = SSH_STATE_BEFORE_SIZE;
3123 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
3126 * Get authconn (really just conn) under way.
3128 do_ssh2_authconn(ssh, NULL, 0, NULL);
3135 static void ssh_process_incoming_data(Ssh ssh,
3136 unsigned char **data, int *datalen)
3138 struct Packet *pktin;
3140 pktin = ssh->s_rdpkt(ssh, data, datalen);
3142 ssh->protocol(ssh, NULL, 0, pktin);
3143 ssh_free_packet(pktin);
3147 static void ssh_queue_incoming_data(Ssh ssh,
3148 unsigned char **data, int *datalen)
3150 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
3155 static void ssh_process_queued_incoming_data(Ssh ssh)
3158 unsigned char *data;
3161 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
3162 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
3166 while (!ssh->frozen && len > 0)
3167 ssh_process_incoming_data(ssh, &data, &len);
3170 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
3174 static void ssh_set_frozen(Ssh ssh, int frozen)
3177 sk_set_frozen(ssh->s, frozen);
3178 ssh->frozen = frozen;
3181 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
3183 /* Log raw data, if we're in that mode. */
3185 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
3186 0, NULL, NULL, 0, NULL);
3188 crBegin(ssh->ssh_gotdata_crstate);
3191 * To begin with, feed the characters one by one to the
3192 * protocol initialisation / selection function do_ssh_init().
3193 * When that returns 0, we're done with the initial greeting
3194 * exchange and can move on to packet discipline.
3197 int ret; /* need not be kept across crReturn */
3199 crReturnV; /* more data please */
3200 ret = ssh->do_ssh_init(ssh, *data);
3208 * We emerge from that loop when the initial negotiation is
3209 * over and we have selected an s_rdpkt function. Now pass
3210 * everything to s_rdpkt, and then pass the resulting packets
3211 * to the proper protocol handler.
3215 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
3217 ssh_queue_incoming_data(ssh, &data, &datalen);
3218 /* This uses up all data and cannot cause anything interesting
3219 * to happen; indeed, for anything to happen at all, we must
3220 * return, so break out. */
3222 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
3223 /* This uses up some or all data, and may freeze the
3225 ssh_process_queued_incoming_data(ssh);
3227 /* This uses up some or all data, and may freeze the
3229 ssh_process_incoming_data(ssh, &data, &datalen);
3231 /* FIXME this is probably EBW. */
3232 if (ssh->state == SSH_STATE_CLOSED)
3235 /* We're out of data. Go and get some more. */
3241 static int ssh_do_close(Ssh ssh, int notify_exit)
3244 struct ssh_channel *c;
3246 ssh->state = SSH_STATE_CLOSED;
3247 expire_timer_context(ssh);
3252 notify_remote_exit(ssh->frontend);
3257 * Now we must shut down any port- and X-forwarded channels going
3258 * through this connection.
3260 if (ssh->channels) {
3261 while (NULL != (c = index234(ssh->channels, 0))) {
3264 x11_close(c->u.x11.xconn);
3267 case CHAN_SOCKDATA_DORMANT:
3268 pfd_close(c->u.pfd.pf);
3271 del234(ssh->channels, c); /* moving next one to index 0 */
3272 if (ssh->version == 2)
3273 bufchain_clear(&c->v.v2.outbuffer);
3278 * Go through port-forwardings, and close any associated
3279 * listening sockets.
3281 if (ssh->portfwds) {
3282 struct ssh_portfwd *pf;
3283 while (NULL != (pf = index234(ssh->portfwds, 0))) {
3284 /* Dispose of any listening socket. */
3286 pfl_terminate(pf->local);
3287 del234(ssh->portfwds, pf); /* moving next one to index 0 */
3290 freetree234(ssh->portfwds);
3291 ssh->portfwds = NULL;
3295 * Also stop attempting to connection-share.
3297 if (ssh->connshare) {
3298 sharestate_free(ssh->connshare);
3299 ssh->connshare = NULL;
3305 static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port,
3306 const char *error_msg, int error_code)
3308 Ssh ssh = (Ssh) plug;
3309 char addrbuf[256], *msg;
3311 if (ssh->attempting_connshare) {
3313 * While we're attempting connection sharing, don't loudly log
3314 * everything that happens. Real TCP connections need to be
3315 * logged when we _start_ trying to connect, because it might
3316 * be ages before they respond if something goes wrong; but
3317 * connection sharing is local and quick to respond, and it's
3318 * sufficient to simply wait and see whether it worked
3322 sk_getaddr(addr, addrbuf, lenof(addrbuf));
3325 if (sk_addr_needs_port(addr)) {
3326 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
3328 msg = dupprintf("Connecting to %s", addrbuf);
3331 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3339 void ssh_connshare_log(Ssh ssh, int event, const char *logtext,
3340 const char *ds_err, const char *us_err)
3342 if (event == SHARE_NONE) {
3343 /* In this case, 'logtext' is an error message indicating a
3344 * reason why connection sharing couldn't be set up _at all_.
3345 * Failing that, ds_err and us_err indicate why we couldn't be
3346 * a downstream and an upstream respectively. */
3348 logeventf(ssh, "Could not set up connection sharing: %s", logtext);
3351 logeventf(ssh, "Could not set up connection sharing"
3352 " as downstream: %s", ds_err);
3354 logeventf(ssh, "Could not set up connection sharing"
3355 " as upstream: %s", us_err);
3357 } else if (event == SHARE_DOWNSTREAM) {
3358 /* In this case, 'logtext' is a local endpoint address */
3359 logeventf(ssh, "Using existing shared connection at %s", logtext);
3360 /* Also we should mention this in the console window to avoid
3361 * confusing users as to why this window doesn't behave the
3363 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3364 c_write_str(ssh,"Reusing a shared connection to this server.\r\n");
3366 } else if (event == SHARE_UPSTREAM) {
3367 /* In this case, 'logtext' is a local endpoint address too */
3368 logeventf(ssh, "Sharing this connection at %s", logtext);
3372 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3375 Ssh ssh = (Ssh) plug;
3376 int need_notify = ssh_do_close(ssh, FALSE);
3379 if (!ssh->close_expected)
3380 error_msg = "Server unexpectedly closed network connection";
3382 error_msg = "Server closed network connection";
3385 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3389 notify_remote_exit(ssh->frontend);
3392 logevent(error_msg);
3393 if (!ssh->close_expected || !ssh->clean_exit)
3394 connection_fatal(ssh->frontend, "%s", error_msg);
3398 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3400 Ssh ssh = (Ssh) plug;
3401 ssh_gotdata(ssh, (unsigned char *)data, len);
3402 if (ssh->state == SSH_STATE_CLOSED) {
3403 ssh_do_close(ssh, TRUE);
3409 static void ssh_sent(Plug plug, int bufsize)
3411 Ssh ssh = (Ssh) plug;
3413 * If the send backlog on the SSH socket itself clears, we
3414 * should unthrottle the whole world if it was throttled.
3416 if (bufsize < SSH_MAX_BACKLOG)
3417 ssh_throttle_all(ssh, 0, bufsize);
3421 * Connect to specified host and port.
3422 * Returns an error message, or NULL on success.
3423 * Also places the canonical host name into `realhost'. It must be
3424 * freed by the caller.
3426 static const char *connect_to_host(Ssh ssh, char *host, int port,
3427 char **realhost, int nodelay, int keepalive)
3429 static const struct plug_function_table fn_table = {
3440 int addressfamily, sshprot;
3442 loghost = conf_get_str(ssh->conf, CONF_loghost);
3447 tmphost = dupstr(loghost);
3448 ssh->savedport = 22; /* default ssh port */
3451 * A colon suffix on the hostname string also lets us affect
3452 * savedport. (Unless there are multiple colons, in which case
3453 * we assume this is an unbracketed IPv6 literal.)
3455 colon = host_strrchr(tmphost, ':');
3456 if (colon && colon == host_strchr(tmphost, ':')) {
3459 ssh->savedport = atoi(colon);
3462 ssh->savedhost = host_strduptrim(tmphost);
3465 ssh->savedhost = host_strduptrim(host);
3467 port = 22; /* default ssh port */
3468 ssh->savedport = port;
3471 ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */
3474 * Try connection-sharing, in case that means we don't open a
3475 * socket after all. ssh_connection_sharing_init will connect to a
3476 * previously established upstream if it can, and failing that,
3477 * establish a listening socket for _us_ to be the upstream. In
3478 * the latter case it will return NULL just as if it had done
3479 * nothing, because here we only need to care if we're a
3480 * downstream and need to do our connection setup differently.
3482 ssh->connshare = NULL;
3483 ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */
3484 ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport,
3485 ssh->conf, ssh, &ssh->connshare);
3486 ssh->attempting_connshare = FALSE;
3487 if (ssh->s != NULL) {
3489 * We are a downstream.
3491 ssh->bare_connection = TRUE;
3492 ssh->do_ssh_init = do_ssh_connection_init;
3493 ssh->fullhostname = NULL;
3494 *realhost = dupstr(host); /* best we can do */
3497 * We're not a downstream, so open a normal socket.
3499 ssh->do_ssh_init = do_ssh_init;
3504 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3505 logeventf(ssh, "Looking up host \"%s\"%s", host,
3506 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3507 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3508 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3509 if ((err = sk_addr_error(addr)) != NULL) {
3513 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3515 ssh->s = new_connection(addr, *realhost, port,
3516 0, 1, nodelay, keepalive,
3517 (Plug) ssh, ssh->conf);
3518 if ((err = sk_socket_error(ssh->s)) != NULL) {
3520 notify_remote_exit(ssh->frontend);
3526 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3527 * send the version string too.
3529 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3532 if (sshprot == 3 && !ssh->bare_connection) {
3534 ssh_send_verstring(ssh, "SSH-", NULL);
3538 * loghost, if configured, overrides realhost.
3542 *realhost = dupstr(loghost);
3549 * Throttle or unthrottle the SSH connection.
3551 static void ssh_throttle_conn(Ssh ssh, int adjust)
3553 int old_count = ssh->conn_throttle_count;
3554 ssh->conn_throttle_count += adjust;
3555 assert(ssh->conn_throttle_count >= 0);
3556 if (ssh->conn_throttle_count && !old_count) {
3557 ssh_set_frozen(ssh, 1);
3558 } else if (!ssh->conn_throttle_count && old_count) {
3559 ssh_set_frozen(ssh, 0);
3564 * Throttle or unthrottle _all_ local data streams (for when sends
3565 * on the SSH connection itself back up).
3567 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3570 struct ssh_channel *c;
3572 if (enable == ssh->throttled_all)
3574 ssh->throttled_all = enable;
3575 ssh->overall_bufsize = bufsize;
3578 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3580 case CHAN_MAINSESSION:
3582 * This is treated separately, outside the switch.
3586 x11_override_throttle(c->u.x11.xconn, enable);
3589 /* Agent channels require no buffer management. */
3592 pfd_override_throttle(c->u.pfd.pf, enable);
3598 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3600 Ssh ssh = (Ssh) sshv;
3602 ssh->agent_response = reply;
3603 ssh->agent_response_len = replylen;
3605 if (ssh->version == 1)
3606 do_ssh1_login(ssh, NULL, -1, NULL);
3608 do_ssh2_authconn(ssh, NULL, -1, NULL);
3611 static void ssh_dialog_callback(void *sshv, int ret)
3613 Ssh ssh = (Ssh) sshv;
3615 ssh->user_response = ret;
3617 if (ssh->version == 1)
3618 do_ssh1_login(ssh, NULL, -1, NULL);
3620 do_ssh2_transport(ssh, NULL, -1, NULL);
3623 * This may have unfrozen the SSH connection, so do a
3626 ssh_process_queued_incoming_data(ssh);
3629 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3631 struct ssh_channel *c = (struct ssh_channel *)cv;
3633 void *sentreply = reply;
3635 c->u.a.outstanding_requests--;
3637 /* Fake SSH_AGENT_FAILURE. */
3638 sentreply = "\0\0\0\1\5";
3641 if (ssh->version == 2) {
3642 ssh2_add_channel_data(c, sentreply, replylen);
3645 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3646 PKT_INT, c->remoteid,
3648 PKT_DATA, sentreply, replylen,
3654 * If we've already seen an incoming EOF but haven't sent an
3655 * outgoing one, this may be the moment to send it.
3657 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3658 sshfwd_write_eof(c);
3662 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3663 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3664 * => log `wire_reason'.
3666 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3667 int code, int clean_exit)
3671 client_reason = wire_reason;
3673 error = dupprintf("Disconnected: %s", client_reason);
3675 error = dupstr("Disconnected");
3677 if (ssh->version == 1) {
3678 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3680 } else if (ssh->version == 2) {
3681 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3682 ssh2_pkt_adduint32(pktout, code);
3683 ssh2_pkt_addstring(pktout, wire_reason);
3684 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3685 ssh2_pkt_send_noqueue(ssh, pktout);
3688 ssh->close_expected = TRUE;
3689 ssh->clean_exit = clean_exit;
3690 ssh_closing((Plug)ssh, error, 0, 0);
3694 int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
3695 const struct ssh_signkey *ssh2keytype,
3698 if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
3699 return -1; /* no manual keys configured */
3704 * The fingerprint string we've been given will have things
3705 * like 'ssh-rsa 2048' at the front of it. Strip those off and
3706 * narrow down to just the colon-separated hex block at the
3707 * end of the string.
3709 const char *p = strrchr(fingerprint, ' ');
3710 fingerprint = p ? p+1 : fingerprint;
3711 /* Quick sanity checks, including making sure it's in lowercase */
3712 assert(strlen(fingerprint) == 16*3 - 1);
3713 assert(fingerprint[2] == ':');
3714 assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
3716 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3718 return 1; /* success */
3723 * Construct the base64-encoded public key blob and see if
3726 unsigned char *binblob;
3728 int binlen, atoms, i;
3729 binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
3730 atoms = (binlen + 2) / 3;
3731 base64blob = snewn(atoms * 4 + 1, char);
3732 for (i = 0; i < atoms; i++)
3733 base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
3734 base64blob[atoms * 4] = '\0';
3736 if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
3739 return 1; /* success */
3748 * Handle the key exchange and user authentication phases.
3750 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3751 struct Packet *pktin)
3754 unsigned char cookie[8], *ptr;
3755 struct MD5Context md5c;
3756 struct do_ssh1_login_state {
3759 unsigned char *rsabuf, *keystr1, *keystr2;
3760 unsigned long supported_ciphers_mask, supported_auths_mask;
3761 int tried_publickey, tried_agent;
3762 int tis_auth_refused, ccard_auth_refused;
3763 unsigned char session_id[16];
3765 void *publickey_blob;
3766 int publickey_bloblen;
3767 char *publickey_comment;
3768 int publickey_encrypted;
3769 prompts_t *cur_prompt;
3772 unsigned char request[5], *response, *p;
3782 struct RSAKey servkey, hostkey;
3784 crState(do_ssh1_login_state);
3791 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3792 bombout(("Public key packet not received"));
3796 logevent("Received public keys");
3798 ptr = ssh_pkt_getdata(pktin, 8);
3800 bombout(("SSH-1 public key packet stopped before random cookie"));
3803 memcpy(cookie, ptr, 8);
3805 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3806 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3807 bombout(("Failed to read SSH-1 public keys from public key packet"));
3812 * Log the host key fingerprint.
3816 logevent("Host key fingerprint is:");
3817 strcpy(logmsg, " ");
3818 s->hostkey.comment = NULL;
3819 rsa_fingerprint(logmsg + strlen(logmsg),
3820 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3824 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3825 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3826 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3827 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3828 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3830 ssh->v1_local_protoflags =
3831 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3832 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3835 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3836 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3837 MD5Update(&md5c, cookie, 8);
3838 MD5Final(s->session_id, &md5c);
3840 for (i = 0; i < 32; i++)
3841 ssh->session_key[i] = random_byte();
3844 * Verify that the `bits' and `bytes' parameters match.
3846 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3847 s->servkey.bits > s->servkey.bytes * 8) {
3848 bombout(("SSH-1 public keys were badly formatted"));
3852 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3853 s->hostkey.bytes : s->servkey.bytes);
3855 s->rsabuf = snewn(s->len, unsigned char);
3858 * Verify the host key.
3862 * First format the key into a string.
3864 int len = rsastr_len(&s->hostkey);
3865 char fingerprint[100];
3866 char *keystr = snewn(len, char);
3867 rsastr_fmt(keystr, &s->hostkey);
3868 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3870 /* First check against manually configured host keys. */
3871 s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
3872 if (s->dlgret == 0) { /* did not match */
3873 bombout(("Host key did not appear in manually configured list"));
3876 } else if (s->dlgret < 0) { /* none configured; use standard handling */
3877 ssh_set_frozen(ssh, 1);
3878 s->dlgret = verify_ssh_host_key(ssh->frontend,
3879 ssh->savedhost, ssh->savedport,
3880 "rsa", keystr, fingerprint,
3881 ssh_dialog_callback, ssh);
3883 if (s->dlgret < 0) {
3887 bombout(("Unexpected data from server while waiting"
3888 " for user host key response"));
3891 } while (pktin || inlen > 0);
3892 s->dlgret = ssh->user_response;
3894 ssh_set_frozen(ssh, 0);
3896 if (s->dlgret == 0) {
3897 ssh_disconnect(ssh, "User aborted at host key verification",
3906 for (i = 0; i < 32; i++) {
3907 s->rsabuf[i] = ssh->session_key[i];
3909 s->rsabuf[i] ^= s->session_id[i];
3912 if (s->hostkey.bytes > s->servkey.bytes) {
3913 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3915 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3917 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3919 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3922 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3926 logevent("Encrypted session key");
3929 int cipher_chosen = 0, warn = 0;
3930 char *cipher_string = NULL;
3932 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3933 int next_cipher = conf_get_int_int(ssh->conf,
3934 CONF_ssh_cipherlist, i);
3935 if (next_cipher == CIPHER_WARN) {
3936 /* If/when we choose a cipher, warn about it */
3938 } else if (next_cipher == CIPHER_AES) {
3939 /* XXX Probably don't need to mention this. */
3940 logevent("AES not supported in SSH-1, skipping");
3942 switch (next_cipher) {
3943 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3944 cipher_string = "3DES"; break;
3945 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3946 cipher_string = "Blowfish"; break;
3947 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3948 cipher_string = "single-DES"; break;
3950 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3954 if (!cipher_chosen) {
3955 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3956 bombout(("Server violates SSH-1 protocol by not "
3957 "supporting 3DES encryption"));
3959 /* shouldn't happen */
3960 bombout(("No supported ciphers found"));
3964 /* Warn about chosen cipher if necessary. */
3966 ssh_set_frozen(ssh, 1);
3967 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3968 ssh_dialog_callback, ssh);
3969 if (s->dlgret < 0) {
3973 bombout(("Unexpected data from server while waiting"
3974 " for user response"));
3977 } while (pktin || inlen > 0);
3978 s->dlgret = ssh->user_response;
3980 ssh_set_frozen(ssh, 0);
3981 if (s->dlgret == 0) {
3982 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3989 switch (s->cipher_type) {
3990 case SSH_CIPHER_3DES:
3991 logevent("Using 3DES encryption");
3993 case SSH_CIPHER_DES:
3994 logevent("Using single-DES encryption");
3996 case SSH_CIPHER_BLOWFISH:
3997 logevent("Using Blowfish encryption");
4001 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
4002 PKT_CHAR, s->cipher_type,
4003 PKT_DATA, cookie, 8,
4004 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
4005 PKT_DATA, s->rsabuf, s->len,
4006 PKT_INT, ssh->v1_local_protoflags, PKT_END);
4008 logevent("Trying to enable encryption...");
4012 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
4013 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
4015 ssh->v1_cipher_ctx = ssh->cipher->make_context();
4016 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
4017 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
4019 ssh->crcda_ctx = crcda_make_context();
4020 logevent("Installing CRC compensation attack detector");
4022 if (s->servkey.modulus) {
4023 sfree(s->servkey.modulus);
4024 s->servkey.modulus = NULL;
4026 if (s->servkey.exponent) {
4027 sfree(s->servkey.exponent);
4028 s->servkey.exponent = NULL;
4030 if (s->hostkey.modulus) {
4031 sfree(s->hostkey.modulus);
4032 s->hostkey.modulus = NULL;
4034 if (s->hostkey.exponent) {
4035 sfree(s->hostkey.exponent);
4036 s->hostkey.exponent = NULL;
4040 if (pktin->type != SSH1_SMSG_SUCCESS) {
4041 bombout(("Encryption not successfully enabled"));
4045 logevent("Successfully started encryption");
4047 fflush(stdout); /* FIXME eh? */
4049 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
4050 int ret; /* need not be kept over crReturn */
4051 s->cur_prompt = new_prompts(ssh->frontend);
4052 s->cur_prompt->to_server = TRUE;
4053 s->cur_prompt->name = dupstr("SSH login name");
4054 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
4055 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4058 crWaitUntil(!pktin);
4059 ret = get_userpass_input(s->cur_prompt, in, inlen);
4064 * Failed to get a username. Terminate.
4066 free_prompts(s->cur_prompt);
4067 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
4070 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
4071 free_prompts(s->cur_prompt);
4074 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
4076 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
4078 if (flags & FLAG_INTERACTIVE &&
4079 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
4080 c_write_str(ssh, userlog);
4081 c_write_str(ssh, "\r\n");
4089 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
4090 /* We must not attempt PK auth. Pretend we've already tried it. */
4091 s->tried_publickey = s->tried_agent = 1;
4093 s->tried_publickey = s->tried_agent = 0;
4095 s->tis_auth_refused = s->ccard_auth_refused = 0;
4097 * Load the public half of any configured keyfile for later use.
4099 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4100 if (!filename_is_null(s->keyfile)) {
4102 logeventf(ssh, "Reading private key file \"%.150s\"",
4103 filename_to_str(s->keyfile));
4104 keytype = key_type(s->keyfile);
4105 if (keytype == SSH_KEYTYPE_SSH1) {
4107 if (rsakey_pubblob(s->keyfile,
4108 &s->publickey_blob, &s->publickey_bloblen,
4109 &s->publickey_comment, &error)) {
4110 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
4114 logeventf(ssh, "Unable to load private key (%s)", error);
4115 msgbuf = dupprintf("Unable to load private key file "
4116 "\"%.150s\" (%s)\r\n",
4117 filename_to_str(s->keyfile),
4119 c_write_str(ssh, msgbuf);
4121 s->publickey_blob = NULL;
4125 logeventf(ssh, "Unable to use this key file (%s)",
4126 key_type_to_str(keytype));
4127 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4129 filename_to_str(s->keyfile),
4130 key_type_to_str(keytype));
4131 c_write_str(ssh, msgbuf);
4133 s->publickey_blob = NULL;
4136 s->publickey_blob = NULL;
4138 while (pktin->type == SSH1_SMSG_FAILURE) {
4139 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
4141 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
4143 * Attempt RSA authentication using Pageant.
4149 logevent("Pageant is running. Requesting keys.");
4151 /* Request the keys held by the agent. */
4152 PUT_32BIT(s->request, 1);
4153 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
4154 if (!agent_query(s->request, 5, &r, &s->responselen,
4155 ssh_agent_callback, ssh)) {
4159 bombout(("Unexpected data from server while waiting"
4160 " for agent response"));
4163 } while (pktin || inlen > 0);
4164 r = ssh->agent_response;
4165 s->responselen = ssh->agent_response_len;
4167 s->response = (unsigned char *) r;
4168 if (s->response && s->responselen >= 5 &&
4169 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
4170 s->p = s->response + 5;
4171 s->nkeys = toint(GET_32BIT(s->p));
4173 logeventf(ssh, "Pageant reported negative key count %d",
4178 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
4179 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4180 unsigned char *pkblob = s->p;
4184 do { /* do while (0) to make breaking easy */
4185 n = ssh1_read_bignum
4186 (s->p, toint(s->responselen-(s->p-s->response)),
4191 n = ssh1_read_bignum
4192 (s->p, toint(s->responselen-(s->p-s->response)),
4197 if (s->responselen - (s->p-s->response) < 4)
4199 s->commentlen = toint(GET_32BIT(s->p));
4201 if (s->commentlen < 0 ||
4202 toint(s->responselen - (s->p-s->response)) <
4205 s->commentp = (char *)s->p;
4206 s->p += s->commentlen;
4210 logevent("Pageant key list packet was truncated");
4214 if (s->publickey_blob) {
4215 if (!memcmp(pkblob, s->publickey_blob,
4216 s->publickey_bloblen)) {
4217 logeventf(ssh, "Pageant key #%d matches "
4218 "configured key file", s->keyi);
4219 s->tried_publickey = 1;
4221 /* Skip non-configured key */
4224 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
4225 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4226 PKT_BIGNUM, s->key.modulus, PKT_END);
4228 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4229 logevent("Key refused");
4232 logevent("Received RSA challenge");
4233 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4234 bombout(("Server's RSA challenge was badly formatted"));
4239 char *agentreq, *q, *ret;
4242 len = 1 + 4; /* message type, bit count */
4243 len += ssh1_bignum_length(s->key.exponent);
4244 len += ssh1_bignum_length(s->key.modulus);
4245 len += ssh1_bignum_length(s->challenge);
4246 len += 16; /* session id */
4247 len += 4; /* response format */
4248 agentreq = snewn(4 + len, char);
4249 PUT_32BIT(agentreq, len);
4251 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
4252 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
4254 q += ssh1_write_bignum(q, s->key.exponent);
4255 q += ssh1_write_bignum(q, s->key.modulus);
4256 q += ssh1_write_bignum(q, s->challenge);
4257 memcpy(q, s->session_id, 16);
4259 PUT_32BIT(q, 1); /* response format */
4260 if (!agent_query(agentreq, len + 4, &vret, &retlen,
4261 ssh_agent_callback, ssh)) {
4266 bombout(("Unexpected data from server"
4267 " while waiting for agent"
4271 } while (pktin || inlen > 0);
4272 vret = ssh->agent_response;
4273 retlen = ssh->agent_response_len;
4278 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
4279 logevent("Sending Pageant's response");
4280 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4281 PKT_DATA, ret + 5, 16,
4285 if (pktin->type == SSH1_SMSG_SUCCESS) {
4287 ("Pageant's response accepted");
4288 if (flags & FLAG_VERBOSE) {
4289 c_write_str(ssh, "Authenticated using"
4291 c_write(ssh, s->commentp,
4293 c_write_str(ssh, "\" from agent\r\n");
4298 ("Pageant's response not accepted");
4301 ("Pageant failed to answer challenge");
4305 logevent("No reply received from Pageant");
4308 freebn(s->key.exponent);
4309 freebn(s->key.modulus);
4310 freebn(s->challenge);
4315 if (s->publickey_blob && !s->tried_publickey)
4316 logevent("Configured key file not in Pageant");
4318 logevent("Failed to get reply from Pageant");
4323 if (s->publickey_blob && !s->tried_publickey) {
4325 * Try public key authentication with the specified
4328 int got_passphrase; /* need not be kept over crReturn */
4329 if (flags & FLAG_VERBOSE)
4330 c_write_str(ssh, "Trying public key authentication.\r\n");
4331 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4332 logeventf(ssh, "Trying public key \"%s\"",
4333 filename_to_str(s->keyfile));
4334 s->tried_publickey = 1;
4335 got_passphrase = FALSE;
4336 while (!got_passphrase) {
4338 * Get a passphrase, if necessary.
4340 char *passphrase = NULL; /* only written after crReturn */
4342 if (!s->publickey_encrypted) {
4343 if (flags & FLAG_VERBOSE)
4344 c_write_str(ssh, "No passphrase required.\r\n");
4347 int ret; /* need not be kept over crReturn */
4348 s->cur_prompt = new_prompts(ssh->frontend);
4349 s->cur_prompt->to_server = FALSE;
4350 s->cur_prompt->name = dupstr("SSH key passphrase");
4351 add_prompt(s->cur_prompt,
4352 dupprintf("Passphrase for key \"%.100s\": ",
4353 s->publickey_comment), FALSE);
4354 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4357 crWaitUntil(!pktin);
4358 ret = get_userpass_input(s->cur_prompt, in, inlen);
4362 /* Failed to get a passphrase. Terminate. */
4363 free_prompts(s->cur_prompt);
4364 ssh_disconnect(ssh, NULL, "Unable to authenticate",
4368 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
4369 free_prompts(s->cur_prompt);
4372 * Try decrypting key with passphrase.
4374 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
4375 ret = loadrsakey(s->keyfile, &s->key, passphrase,
4378 smemclr(passphrase, strlen(passphrase));
4382 /* Correct passphrase. */
4383 got_passphrase = TRUE;
4384 } else if (ret == 0) {
4385 c_write_str(ssh, "Couldn't load private key from ");
4386 c_write_str(ssh, filename_to_str(s->keyfile));
4387 c_write_str(ssh, " (");
4388 c_write_str(ssh, error);
4389 c_write_str(ssh, ").\r\n");
4390 got_passphrase = FALSE;
4391 break; /* go and try something else */
4392 } else if (ret == -1) {
4393 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
4394 got_passphrase = FALSE;
4397 assert(0 && "unexpected return from loadrsakey()");
4398 got_passphrase = FALSE; /* placate optimisers */
4402 if (got_passphrase) {
4405 * Send a public key attempt.
4407 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
4408 PKT_BIGNUM, s->key.modulus, PKT_END);
4411 if (pktin->type == SSH1_SMSG_FAILURE) {
4412 c_write_str(ssh, "Server refused our public key.\r\n");
4413 continue; /* go and try something else */
4415 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
4416 bombout(("Bizarre response to offer of public key"));
4422 unsigned char buffer[32];
4423 Bignum challenge, response;
4425 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
4426 bombout(("Server's RSA challenge was badly formatted"));
4429 response = rsadecrypt(challenge, &s->key);
4430 freebn(s->key.private_exponent);/* burn the evidence */
4432 for (i = 0; i < 32; i++) {
4433 buffer[i] = bignum_byte(response, 31 - i);
4437 MD5Update(&md5c, buffer, 32);
4438 MD5Update(&md5c, s->session_id, 16);
4439 MD5Final(buffer, &md5c);
4441 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
4442 PKT_DATA, buffer, 16, PKT_END);
4449 if (pktin->type == SSH1_SMSG_FAILURE) {
4450 if (flags & FLAG_VERBOSE)
4451 c_write_str(ssh, "Failed to authenticate with"
4452 " our public key.\r\n");
4453 continue; /* go and try something else */
4454 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4455 bombout(("Bizarre response to RSA authentication response"));
4459 break; /* we're through! */
4465 * Otherwise, try various forms of password-like authentication.
4467 s->cur_prompt = new_prompts(ssh->frontend);
4469 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4470 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4471 !s->tis_auth_refused) {
4472 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4473 logevent("Requested TIS authentication");
4474 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4476 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4477 logevent("TIS authentication declined");
4478 if (flags & FLAG_INTERACTIVE)
4479 c_write_str(ssh, "TIS authentication refused.\r\n");
4480 s->tis_auth_refused = 1;
4485 char *instr_suf, *prompt;
4487 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4489 bombout(("TIS challenge packet was badly formed"));
4492 logevent("Received TIS challenge");
4493 s->cur_prompt->to_server = TRUE;
4494 s->cur_prompt->name = dupstr("SSH TIS authentication");
4495 /* Prompt heuristic comes from OpenSSH */
4496 if (memchr(challenge, '\n', challengelen)) {
4497 instr_suf = dupstr("");
4498 prompt = dupprintf("%.*s", challengelen, challenge);
4500 instr_suf = dupprintf("%.*s", challengelen, challenge);
4501 prompt = dupstr("Response: ");
4503 s->cur_prompt->instruction =
4504 dupprintf("Using TIS authentication.%s%s",
4505 (*instr_suf) ? "\n" : "",
4507 s->cur_prompt->instr_reqd = TRUE;
4508 add_prompt(s->cur_prompt, prompt, FALSE);
4512 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4513 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4514 !s->ccard_auth_refused) {
4515 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4516 logevent("Requested CryptoCard authentication");
4517 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4519 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4520 logevent("CryptoCard authentication declined");
4521 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4522 s->ccard_auth_refused = 1;
4527 char *instr_suf, *prompt;
4529 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4531 bombout(("CryptoCard challenge packet was badly formed"));
4534 logevent("Received CryptoCard challenge");
4535 s->cur_prompt->to_server = TRUE;
4536 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4537 s->cur_prompt->name_reqd = FALSE;
4538 /* Prompt heuristic comes from OpenSSH */
4539 if (memchr(challenge, '\n', challengelen)) {
4540 instr_suf = dupstr("");
4541 prompt = dupprintf("%.*s", challengelen, challenge);
4543 instr_suf = dupprintf("%.*s", challengelen, challenge);
4544 prompt = dupstr("Response: ");
4546 s->cur_prompt->instruction =
4547 dupprintf("Using CryptoCard authentication.%s%s",
4548 (*instr_suf) ? "\n" : "",
4550 s->cur_prompt->instr_reqd = TRUE;
4551 add_prompt(s->cur_prompt, prompt, FALSE);
4555 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4556 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4557 bombout(("No supported authentication methods available"));
4560 s->cur_prompt->to_server = TRUE;
4561 s->cur_prompt->name = dupstr("SSH password");
4562 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4563 ssh->username, ssh->savedhost),
4568 * Show password prompt, having first obtained it via a TIS
4569 * or CryptoCard exchange if we're doing TIS or CryptoCard
4573 int ret; /* need not be kept over crReturn */
4574 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4577 crWaitUntil(!pktin);
4578 ret = get_userpass_input(s->cur_prompt, in, inlen);
4583 * Failed to get a password (for example
4584 * because one was supplied on the command line
4585 * which has already failed to work). Terminate.
4587 free_prompts(s->cur_prompt);
4588 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4593 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4595 * Defence against traffic analysis: we send a
4596 * whole bunch of packets containing strings of
4597 * different lengths. One of these strings is the
4598 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4599 * The others are all random data in
4600 * SSH1_MSG_IGNORE packets. This way a passive
4601 * listener can't tell which is the password, and
4602 * hence can't deduce the password length.
4604 * Anybody with a password length greater than 16
4605 * bytes is going to have enough entropy in their
4606 * password that a listener won't find it _that_
4607 * much help to know how long it is. So what we'll
4610 * - if password length < 16, we send 15 packets
4611 * containing string lengths 1 through 15
4613 * - otherwise, we let N be the nearest multiple
4614 * of 8 below the password length, and send 8
4615 * packets containing string lengths N through
4616 * N+7. This won't obscure the order of
4617 * magnitude of the password length, but it will
4618 * introduce a bit of extra uncertainty.
4620 * A few servers can't deal with SSH1_MSG_IGNORE, at
4621 * least in this context. For these servers, we need
4622 * an alternative defence. We make use of the fact
4623 * that the password is interpreted as a C string:
4624 * so we can append a NUL, then some random data.
4626 * A few servers can deal with neither SSH1_MSG_IGNORE
4627 * here _nor_ a padded password string.
4628 * For these servers we are left with no defences
4629 * against password length sniffing.
4631 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4632 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4634 * The server can deal with SSH1_MSG_IGNORE, so
4635 * we can use the primary defence.
4637 int bottom, top, pwlen, i;
4640 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4642 bottom = 0; /* zero length passwords are OK! :-) */
4645 bottom = pwlen & ~7;
4649 assert(pwlen >= bottom && pwlen <= top);
4651 randomstr = snewn(top + 1, char);
4653 for (i = bottom; i <= top; i++) {
4655 defer_packet(ssh, s->pwpkt_type,
4656 PKT_STR,s->cur_prompt->prompts[0]->result,
4659 for (j = 0; j < i; j++) {
4661 randomstr[j] = random_byte();
4662 } while (randomstr[j] == '\0');
4664 randomstr[i] = '\0';
4665 defer_packet(ssh, SSH1_MSG_IGNORE,
4666 PKT_STR, randomstr, PKT_END);
4669 logevent("Sending password with camouflage packets");
4670 ssh_pkt_defersend(ssh);
4673 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4675 * The server can't deal with SSH1_MSG_IGNORE
4676 * but can deal with padded passwords, so we
4677 * can use the secondary defence.
4683 len = strlen(s->cur_prompt->prompts[0]->result);
4684 if (len < sizeof(string)) {
4686 strcpy(string, s->cur_prompt->prompts[0]->result);
4687 len++; /* cover the zero byte */
4688 while (len < sizeof(string)) {
4689 string[len++] = (char) random_byte();
4692 ss = s->cur_prompt->prompts[0]->result;
4694 logevent("Sending length-padded password");
4695 send_packet(ssh, s->pwpkt_type,
4696 PKT_INT, len, PKT_DATA, ss, len,
4700 * The server is believed unable to cope with
4701 * any of our password camouflage methods.
4704 len = strlen(s->cur_prompt->prompts[0]->result);
4705 logevent("Sending unpadded password");
4706 send_packet(ssh, s->pwpkt_type,
4708 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4712 send_packet(ssh, s->pwpkt_type,
4713 PKT_STR, s->cur_prompt->prompts[0]->result,
4716 logevent("Sent password");
4717 free_prompts(s->cur_prompt);
4719 if (pktin->type == SSH1_SMSG_FAILURE) {
4720 if (flags & FLAG_VERBOSE)
4721 c_write_str(ssh, "Access denied\r\n");
4722 logevent("Authentication refused");
4723 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4724 bombout(("Strange packet received, type %d", pktin->type));
4730 if (s->publickey_blob) {
4731 sfree(s->publickey_blob);
4732 sfree(s->publickey_comment);
4735 logevent("Authentication successful");
4740 static void ssh_channel_try_eof(struct ssh_channel *c)
4743 assert(c->pending_eof); /* precondition for calling us */
4745 return; /* can't close: not even opened yet */
4746 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4747 return; /* can't send EOF: pending outgoing data */
4749 c->pending_eof = FALSE; /* we're about to send it */
4750 if (ssh->version == 1) {
4751 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4753 c->closes |= CLOSES_SENT_EOF;
4755 struct Packet *pktout;
4756 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4757 ssh2_pkt_adduint32(pktout, c->remoteid);
4758 ssh2_pkt_send(ssh, pktout);
4759 c->closes |= CLOSES_SENT_EOF;
4760 ssh2_channel_check_close(c);
4764 Conf *sshfwd_get_conf(struct ssh_channel *c)
4770 void sshfwd_write_eof(struct ssh_channel *c)
4774 if (ssh->state == SSH_STATE_CLOSED)
4777 if (c->closes & CLOSES_SENT_EOF)
4780 c->pending_eof = TRUE;
4781 ssh_channel_try_eof(c);
4784 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4788 if (ssh->state == SSH_STATE_CLOSED)
4793 x11_close(c->u.x11.xconn);
4794 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4798 case CHAN_SOCKDATA_DORMANT:
4799 pfd_close(c->u.pfd.pf);
4800 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4803 c->type = CHAN_ZOMBIE;
4804 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4806 ssh2_channel_check_close(c);
4809 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4813 if (ssh->state == SSH_STATE_CLOSED)
4816 if (ssh->version == 1) {
4817 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4818 PKT_INT, c->remoteid,
4819 PKT_INT, len, PKT_DATA, buf, len,
4822 * In SSH-1 we can return 0 here - implying that forwarded
4823 * connections are never individually throttled - because
4824 * the only circumstance that can cause throttling will be
4825 * the whole SSH connection backing up, in which case
4826 * _everything_ will be throttled as a whole.
4830 ssh2_add_channel_data(c, buf, len);
4831 return ssh2_try_send(c);
4835 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4840 if (ssh->state == SSH_STATE_CLOSED)
4843 if (ssh->version == 1) {
4844 buflimit = SSH1_BUFFER_LIMIT;
4846 buflimit = c->v.v2.locmaxwin;
4847 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4849 if (c->throttling_conn && bufsize <= buflimit) {
4850 c->throttling_conn = 0;
4851 ssh_throttle_conn(ssh, -1);
4855 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4857 struct queued_handler *qh = ssh->qhead;
4861 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4864 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4865 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4868 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4869 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4873 ssh->qhead = qh->next;
4875 if (ssh->qhead->msg1 > 0) {
4876 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4877 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4879 if (ssh->qhead->msg2 > 0) {
4880 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4881 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4884 ssh->qhead = ssh->qtail = NULL;
4887 qh->handler(ssh, pktin, qh->ctx);
4892 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4893 chandler_fn_t handler, void *ctx)
4895 struct queued_handler *qh;
4897 qh = snew(struct queued_handler);
4900 qh->handler = handler;
4904 if (ssh->qtail == NULL) {
4908 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4909 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4912 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4913 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4916 ssh->qtail->next = qh;
4921 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4923 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4925 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4926 SSH2_MSG_REQUEST_SUCCESS)) {
4927 logeventf(ssh, "Remote port forwarding from %s enabled",
4930 logeventf(ssh, "Remote port forwarding from %s refused",
4933 rpf = del234(ssh->rportfwds, pf);
4935 pf->pfrec->remote = NULL;
4940 int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport,
4943 struct ssh_rportfwd *pf = snew(struct ssh_rportfwd);
4946 pf->share_ctx = share_ctx;
4947 pf->shost = dupstr(shost);
4949 pf->sportdesc = NULL;
4950 if (!ssh->rportfwds) {
4951 assert(ssh->version == 2);
4952 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4954 if (add234(ssh->rportfwds, pf) != pf) {
4962 static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin,
4965 share_got_pkt_from_server(ctx, pktin->type,
4966 pktin->body, pktin->length);
4969 void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx)
4971 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE,
4972 ssh_sharing_global_request_response, share_ctx);
4975 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4977 struct ssh_portfwd *epf;
4981 if (!ssh->portfwds) {
4982 ssh->portfwds = newtree234(ssh_portcmp);
4985 * Go through the existing port forwardings and tag them
4986 * with status==DESTROY. Any that we want to keep will be
4987 * re-enabled (status==KEEP) as we go through the
4988 * configuration and find out which bits are the same as
4991 struct ssh_portfwd *epf;
4993 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4994 epf->status = DESTROY;
4997 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4999 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
5000 char *kp, *kp2, *vp, *vp2;
5001 char address_family, type;
5002 int sport,dport,sserv,dserv;
5003 char *sports, *dports, *saddr, *host;
5007 address_family = 'A';
5009 if (*kp == 'A' || *kp == '4' || *kp == '6')
5010 address_family = *kp++;
5011 if (*kp == 'L' || *kp == 'R')
5014 if ((kp2 = host_strchr(kp, ':')) != NULL) {
5016 * There's a colon in the middle of the source port
5017 * string, which means that the part before it is
5018 * actually a source address.
5020 char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp);
5021 saddr = host_strduptrim(saddr_tmp);
5028 sport = atoi(sports);
5032 sport = net_service_lookup(sports);
5034 logeventf(ssh, "Service lookup failed for source"
5035 " port \"%s\"", sports);
5039 if (type == 'L' && !strcmp(val, "D")) {
5040 /* dynamic forwarding */
5047 /* ordinary forwarding */
5049 vp2 = vp + host_strcspn(vp, ":");
5050 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
5054 dport = atoi(dports);
5058 dport = net_service_lookup(dports);
5060 logeventf(ssh, "Service lookup failed for destination"
5061 " port \"%s\"", dports);
5066 if (sport && dport) {
5067 /* Set up a description of the source port. */
5068 struct ssh_portfwd *pfrec, *epfrec;
5070 pfrec = snew(struct ssh_portfwd);
5072 pfrec->saddr = saddr;
5073 pfrec->sserv = sserv ? dupstr(sports) : NULL;
5074 pfrec->sport = sport;
5075 pfrec->daddr = host;
5076 pfrec->dserv = dserv ? dupstr(dports) : NULL;
5077 pfrec->dport = dport;
5078 pfrec->local = NULL;
5079 pfrec->remote = NULL;
5080 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
5081 address_family == '6' ? ADDRTYPE_IPV6 :
5084 epfrec = add234(ssh->portfwds, pfrec);
5085 if (epfrec != pfrec) {
5086 if (epfrec->status == DESTROY) {
5088 * We already have a port forwarding up and running
5089 * with precisely these parameters. Hence, no need
5090 * to do anything; simply re-tag the existing one
5093 epfrec->status = KEEP;
5096 * Anything else indicates that there was a duplicate
5097 * in our input, which we'll silently ignore.
5099 free_portfwd(pfrec);
5101 pfrec->status = CREATE;
5110 * Now go through and destroy any port forwardings which were
5113 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5114 if (epf->status == DESTROY) {
5117 message = dupprintf("%s port forwarding from %s%s%d",
5118 epf->type == 'L' ? "local" :
5119 epf->type == 'R' ? "remote" : "dynamic",
5120 epf->saddr ? epf->saddr : "",
5121 epf->saddr ? ":" : "",
5124 if (epf->type != 'D') {
5125 char *msg2 = dupprintf("%s to %s:%d", message,
5126 epf->daddr, epf->dport);
5131 logeventf(ssh, "Cancelling %s", message);
5134 /* epf->remote or epf->local may be NULL if setting up a
5135 * forwarding failed. */
5137 struct ssh_rportfwd *rpf = epf->remote;
5138 struct Packet *pktout;
5141 * Cancel the port forwarding at the server
5144 if (ssh->version == 1) {
5146 * We cannot cancel listening ports on the
5147 * server side in SSH-1! There's no message
5148 * to support it. Instead, we simply remove
5149 * the rportfwd record from the local end
5150 * so that any connections the server tries
5151 * to make on it are rejected.
5154 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5155 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
5156 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
5158 ssh2_pkt_addstring(pktout, epf->saddr);
5159 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5160 /* XXX: rport_acceptall may not represent
5161 * what was used to open the original connection,
5162 * since it's reconfigurable. */
5163 ssh2_pkt_addstring(pktout, "");
5165 ssh2_pkt_addstring(pktout, "localhost");
5167 ssh2_pkt_adduint32(pktout, epf->sport);
5168 ssh2_pkt_send(ssh, pktout);
5171 del234(ssh->rportfwds, rpf);
5173 } else if (epf->local) {
5174 pfl_terminate(epf->local);
5177 delpos234(ssh->portfwds, i);
5179 i--; /* so we don't skip one in the list */
5183 * And finally, set up any new port forwardings (status==CREATE).
5185 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
5186 if (epf->status == CREATE) {
5187 char *sportdesc, *dportdesc;
5188 sportdesc = dupprintf("%s%s%s%s%d%s",
5189 epf->saddr ? epf->saddr : "",
5190 epf->saddr ? ":" : "",
5191 epf->sserv ? epf->sserv : "",
5192 epf->sserv ? "(" : "",
5194 epf->sserv ? ")" : "");
5195 if (epf->type == 'D') {
5198 dportdesc = dupprintf("%s:%s%s%d%s",
5200 epf->dserv ? epf->dserv : "",
5201 epf->dserv ? "(" : "",
5203 epf->dserv ? ")" : "");
5206 if (epf->type == 'L') {
5207 char *err = pfl_listen(epf->daddr, epf->dport,
5208 epf->saddr, epf->sport,
5209 ssh, conf, &epf->local,
5210 epf->addressfamily);
5212 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
5213 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5214 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5215 sportdesc, dportdesc,
5216 err ? " failed: " : "", err ? err : "");
5219 } else if (epf->type == 'D') {
5220 char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport,
5221 ssh, conf, &epf->local,
5222 epf->addressfamily);
5224 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
5225 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
5226 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
5228 err ? " failed: " : "", err ? err : "");
5233 struct ssh_rportfwd *pf;
5236 * Ensure the remote port forwardings tree exists.
5238 if (!ssh->rportfwds) {
5239 if (ssh->version == 1)
5240 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
5242 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5245 pf = snew(struct ssh_rportfwd);
5246 pf->share_ctx = NULL;
5247 pf->dhost = dupstr(epf->daddr);
5248 pf->dport = epf->dport;
5250 pf->shost = dupstr(epf->saddr);
5251 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
5252 pf->shost = dupstr("");
5254 pf->shost = dupstr("localhost");
5256 pf->sport = epf->sport;
5257 if (add234(ssh->rportfwds, pf) != pf) {
5258 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
5259 epf->daddr, epf->dport);
5262 logeventf(ssh, "Requesting remote port %s"
5263 " forward to %s", sportdesc, dportdesc);
5265 pf->sportdesc = sportdesc;
5270 if (ssh->version == 1) {
5271 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
5272 PKT_INT, epf->sport,
5273 PKT_STR, epf->daddr,
5274 PKT_INT, epf->dport,
5276 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
5278 ssh_rportfwd_succfail, pf);
5280 struct Packet *pktout;
5281 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5282 ssh2_pkt_addstring(pktout, "tcpip-forward");
5283 ssh2_pkt_addbool(pktout, 1);/* want reply */
5284 ssh2_pkt_addstring(pktout, pf->shost);
5285 ssh2_pkt_adduint32(pktout, pf->sport);
5286 ssh2_pkt_send(ssh, pktout);
5288 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
5289 SSH2_MSG_REQUEST_FAILURE,
5290 ssh_rportfwd_succfail, pf);
5299 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
5302 int stringlen, bufsize;
5304 ssh_pkt_getstring(pktin, &string, &stringlen);
5305 if (string == NULL) {
5306 bombout(("Incoming terminal data packet was badly formed"));
5310 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
5312 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5313 ssh->v1_stdout_throttling = 1;
5314 ssh_throttle_conn(ssh, +1);
5318 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
5320 /* Remote side is trying to open a channel to talk to our
5321 * X-Server. Give them back a local channel number. */
5322 struct ssh_channel *c;
5323 int remoteid = ssh_pkt_getuint32(pktin);
5325 logevent("Received X11 connect request");
5326 /* Refuse if X11 forwarding is disabled. */
5327 if (!ssh->X11_fwd_enabled) {
5328 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5329 PKT_INT, remoteid, PKT_END);
5330 logevent("Rejected X11 connect request");
5332 c = snew(struct ssh_channel);
5335 c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1);
5336 c->remoteid = remoteid;
5337 c->halfopen = FALSE;
5338 c->localid = alloc_channel_id(ssh);
5340 c->pending_eof = FALSE;
5341 c->throttling_conn = 0;
5342 c->type = CHAN_X11; /* identify channel type */
5343 add234(ssh->channels, c);
5344 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5345 PKT_INT, c->remoteid, PKT_INT,
5346 c->localid, PKT_END);
5347 logevent("Opened X11 forward channel");
5351 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
5353 /* Remote side is trying to open a channel to talk to our
5354 * agent. Give them back a local channel number. */
5355 struct ssh_channel *c;
5356 int remoteid = ssh_pkt_getuint32(pktin);
5358 /* Refuse if agent forwarding is disabled. */
5359 if (!ssh->agentfwd_enabled) {
5360 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5361 PKT_INT, remoteid, PKT_END);
5363 c = snew(struct ssh_channel);
5365 c->remoteid = remoteid;
5366 c->halfopen = FALSE;
5367 c->localid = alloc_channel_id(ssh);
5369 c->pending_eof = FALSE;
5370 c->throttling_conn = 0;
5371 c->type = CHAN_AGENT; /* identify channel type */
5372 c->u.a.lensofar = 0;
5373 c->u.a.message = NULL;
5374 c->u.a.outstanding_requests = 0;
5375 add234(ssh->channels, c);
5376 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5377 PKT_INT, c->remoteid, PKT_INT, c->localid,
5382 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
5384 /* Remote side is trying to open a channel to talk to a
5385 * forwarded port. Give them back a local channel number. */
5386 struct ssh_rportfwd pf, *pfp;
5392 remoteid = ssh_pkt_getuint32(pktin);
5393 ssh_pkt_getstring(pktin, &host, &hostsize);
5394 port = ssh_pkt_getuint32(pktin);
5396 pf.dhost = dupprintf("%.*s", hostsize, host);
5398 pfp = find234(ssh->rportfwds, &pf, NULL);
5401 logeventf(ssh, "Rejected remote port open request for %s:%d",
5403 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5404 PKT_INT, remoteid, PKT_END);
5406 struct ssh_channel *c = snew(struct ssh_channel);
5409 logeventf(ssh, "Received remote port open request for %s:%d",
5411 err = pfd_connect(&c->u.pfd.pf, pf.dhost, port,
5412 c, ssh->conf, pfp->pfrec->addressfamily);
5414 logeventf(ssh, "Port open failed: %s", err);
5417 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
5418 PKT_INT, remoteid, PKT_END);
5420 c->remoteid = remoteid;
5421 c->halfopen = FALSE;
5422 c->localid = alloc_channel_id(ssh);
5424 c->pending_eof = FALSE;
5425 c->throttling_conn = 0;
5426 c->type = CHAN_SOCKDATA; /* identify channel type */
5427 add234(ssh->channels, c);
5428 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
5429 PKT_INT, c->remoteid, PKT_INT,
5430 c->localid, PKT_END);
5431 logevent("Forwarded port opened successfully");
5438 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5440 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5441 unsigned int localid = ssh_pkt_getuint32(pktin);
5442 struct ssh_channel *c;
5444 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5445 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5446 c->remoteid = localid;
5447 c->halfopen = FALSE;
5448 c->type = CHAN_SOCKDATA;
5449 c->throttling_conn = 0;
5450 pfd_confirm(c->u.pfd.pf);
5453 if (c && c->pending_eof) {
5455 * We have a pending close on this channel,
5456 * which we decided on before the server acked
5457 * the channel open. So now we know the
5458 * remoteid, we can close it again.
5460 ssh_channel_try_eof(c);
5464 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5466 unsigned int remoteid = ssh_pkt_getuint32(pktin);
5467 struct ssh_channel *c;
5469 c = find234(ssh->channels, &remoteid, ssh_channelfind);
5470 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
5471 logevent("Forwarded connection refused by server");
5472 pfd_close(c->u.pfd.pf);
5473 del234(ssh->channels, c);
5478 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
5480 /* Remote side closes a channel. */
5481 unsigned i = ssh_pkt_getuint32(pktin);
5482 struct ssh_channel *c;
5483 c = find234(ssh->channels, &i, ssh_channelfind);
5484 if (c && !c->halfopen) {
5486 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
5487 !(c->closes & CLOSES_RCVD_EOF)) {
5489 * Received CHANNEL_CLOSE, which we translate into
5492 int send_close = FALSE;
5494 c->closes |= CLOSES_RCVD_EOF;
5499 x11_send_eof(c->u.x11.xconn);
5505 pfd_send_eof(c->u.pfd.pf);
5514 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5515 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5517 c->closes |= CLOSES_SENT_EOF;
5521 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5522 !(c->closes & CLOSES_RCVD_CLOSE)) {
5524 if (!(c->closes & CLOSES_SENT_EOF)) {
5525 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5526 " for which we never sent CHANNEL_CLOSE\n", i));
5529 c->closes |= CLOSES_RCVD_CLOSE;
5532 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5533 !(c->closes & CLOSES_SENT_CLOSE)) {
5534 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5535 PKT_INT, c->remoteid, PKT_END);
5536 c->closes |= CLOSES_SENT_CLOSE;
5539 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5540 ssh_channel_destroy(c);
5542 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5543 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5544 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5549 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5551 /* Data sent down one of our channels. */
5552 int i = ssh_pkt_getuint32(pktin);
5555 struct ssh_channel *c;
5557 ssh_pkt_getstring(pktin, &p, &len);
5559 c = find234(ssh->channels, &i, ssh_channelfind);
5564 bufsize = x11_send(c->u.x11.xconn, p, len);
5567 bufsize = pfd_send(c->u.pfd.pf, p, len);
5570 /* Data for an agent message. Buffer it. */
5572 if (c->u.a.lensofar < 4) {
5573 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5574 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5578 c->u.a.lensofar += l;
5580 if (c->u.a.lensofar == 4) {
5582 4 + GET_32BIT(c->u.a.msglen);
5583 c->u.a.message = snewn(c->u.a.totallen,
5585 memcpy(c->u.a.message, c->u.a.msglen, 4);
5587 if (c->u.a.lensofar >= 4 && len > 0) {
5589 min(c->u.a.totallen - c->u.a.lensofar,
5591 memcpy(c->u.a.message + c->u.a.lensofar, p,
5595 c->u.a.lensofar += l;
5597 if (c->u.a.lensofar == c->u.a.totallen) {
5600 c->u.a.outstanding_requests++;
5601 if (agent_query(c->u.a.message,
5604 ssh_agentf_callback, c))
5605 ssh_agentf_callback(c, reply, replylen);
5606 sfree(c->u.a.message);
5607 c->u.a.lensofar = 0;
5610 bufsize = 0; /* agent channels never back up */
5613 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5614 c->throttling_conn = 1;
5615 ssh_throttle_conn(ssh, +1);
5620 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5622 ssh->exitcode = ssh_pkt_getuint32(pktin);
5623 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5624 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5626 * In case `helpful' firewalls or proxies tack
5627 * extra human-readable text on the end of the
5628 * session which we might mistake for another
5629 * encrypted packet, we close the session once
5630 * we've sent EXIT_CONFIRMATION.
5632 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5635 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5636 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5638 struct Packet *pktout = (struct Packet *)data;
5640 unsigned int arg = 0;
5641 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5642 if (i == lenof(ssh_ttymodes)) return;
5643 switch (ssh_ttymodes[i].type) {
5645 arg = ssh_tty_parse_specchar(val);
5648 arg = ssh_tty_parse_boolean(val);
5651 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5652 ssh2_pkt_addbyte(pktout, arg);
5655 int ssh_agent_forwarding_permitted(Ssh ssh)
5657 return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists();
5660 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5661 struct Packet *pktin)
5663 crBegin(ssh->do_ssh1_connection_crstate);
5665 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5666 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5667 ssh1_smsg_stdout_stderr_data;
5669 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5670 ssh1_msg_channel_open_confirmation;
5671 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5672 ssh1_msg_channel_open_failure;
5673 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5674 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5675 ssh1_msg_channel_close;
5676 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5677 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5679 if (ssh_agent_forwarding_permitted(ssh)) {
5680 logevent("Requesting agent forwarding");
5681 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5685 if (pktin->type != SSH1_SMSG_SUCCESS
5686 && pktin->type != SSH1_SMSG_FAILURE) {
5687 bombout(("Protocol confusion"));
5689 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5690 logevent("Agent forwarding refused");
5692 logevent("Agent forwarding enabled");
5693 ssh->agentfwd_enabled = TRUE;
5694 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5698 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
5700 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5702 if (!ssh->x11disp) {
5703 /* FIXME: return an error message from x11_setup_display */
5704 logevent("X11 forwarding not enabled: unable to"
5705 " initialise X display");
5707 ssh->x11auth = x11_invent_fake_auth
5708 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
5709 ssh->x11auth->disp = ssh->x11disp;
5711 logevent("Requesting X11 forwarding");
5712 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5713 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5714 PKT_STR, ssh->x11auth->protoname,
5715 PKT_STR, ssh->x11auth->datastring,
5716 PKT_INT, ssh->x11disp->screennum,
5719 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5720 PKT_STR, ssh->x11auth->protoname,
5721 PKT_STR, ssh->x11auth->datastring,
5727 if (pktin->type != SSH1_SMSG_SUCCESS
5728 && pktin->type != SSH1_SMSG_FAILURE) {
5729 bombout(("Protocol confusion"));
5731 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5732 logevent("X11 forwarding refused");
5734 logevent("X11 forwarding enabled");
5735 ssh->X11_fwd_enabled = TRUE;
5736 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5741 ssh_setup_portfwd(ssh, ssh->conf);
5742 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5744 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5746 /* Unpick the terminal-speed string. */
5747 /* XXX perhaps we should allow no speeds to be sent. */
5748 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5749 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5750 /* Send the pty request. */
5751 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5752 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5753 ssh_pkt_adduint32(pkt, ssh->term_height);
5754 ssh_pkt_adduint32(pkt, ssh->term_width);
5755 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5756 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5757 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5758 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5759 ssh_pkt_adduint32(pkt, ssh->ispeed);
5760 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5761 ssh_pkt_adduint32(pkt, ssh->ospeed);
5762 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5764 ssh->state = SSH_STATE_INTERMED;
5768 if (pktin->type != SSH1_SMSG_SUCCESS
5769 && pktin->type != SSH1_SMSG_FAILURE) {
5770 bombout(("Protocol confusion"));
5772 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5773 c_write_str(ssh, "Server refused to allocate pty\r\n");
5774 ssh->editing = ssh->echoing = 1;
5776 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5777 ssh->ospeed, ssh->ispeed);
5778 ssh->got_pty = TRUE;
5781 ssh->editing = ssh->echoing = 1;
5784 if (conf_get_int(ssh->conf, CONF_compression)) {
5785 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5789 if (pktin->type != SSH1_SMSG_SUCCESS
5790 && pktin->type != SSH1_SMSG_FAILURE) {
5791 bombout(("Protocol confusion"));
5793 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5794 c_write_str(ssh, "Server refused to compress\r\n");
5796 logevent("Started compression");
5797 ssh->v1_compressing = TRUE;
5798 ssh->cs_comp_ctx = zlib_compress_init();
5799 logevent("Initialised zlib (RFC1950) compression");
5800 ssh->sc_comp_ctx = zlib_decompress_init();
5801 logevent("Initialised zlib (RFC1950) decompression");
5805 * Start the shell or command.
5807 * Special case: if the first-choice command is an SSH-2
5808 * subsystem (hence not usable here) and the second choice
5809 * exists, we fall straight back to that.
5812 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5814 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5815 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5816 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5817 ssh->fallback_cmd = TRUE;
5820 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5822 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5823 logevent("Started session");
5826 ssh->state = SSH_STATE_SESSION;
5827 if (ssh->size_needed)
5828 ssh_size(ssh, ssh->term_width, ssh->term_height);
5829 if (ssh->eof_needed)
5830 ssh_special(ssh, TS_EOF);
5833 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5835 ssh->channels = newtree234(ssh_channelcmp);
5839 * By this point, most incoming packets are already being
5840 * handled by the dispatch table, and we need only pay
5841 * attention to the unusual ones.
5846 if (pktin->type == SSH1_SMSG_SUCCESS) {
5847 /* may be from EXEC_SHELL on some servers */
5848 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5849 /* may be from EXEC_SHELL on some servers
5850 * if no pty is available or in other odd cases. Ignore */
5852 bombout(("Strange packet received: type %d", pktin->type));
5857 int len = min(inlen, 512);
5858 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5859 PKT_INT, len, PKT_DATA, in, len,
5871 * Handle the top-level SSH-2 protocol.
5873 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5878 ssh_pkt_getstring(pktin, &msg, &msglen);
5879 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5882 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5884 /* log reason code in disconnect message */
5888 ssh_pkt_getstring(pktin, &msg, &msglen);
5889 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5892 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5894 /* Do nothing, because we're ignoring it! Duhh. */
5897 static void ssh1_protocol_setup(Ssh ssh)
5902 * Most messages are handled by the coroutines.
5904 for (i = 0; i < 256; i++)
5905 ssh->packet_dispatch[i] = NULL;
5908 * These special message types we install handlers for.
5910 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5911 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5912 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5915 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5916 struct Packet *pktin)
5918 unsigned char *in=(unsigned char*)vin;
5919 if (ssh->state == SSH_STATE_CLOSED)
5922 if (pktin && ssh->packet_dispatch[pktin->type]) {
5923 ssh->packet_dispatch[pktin->type](ssh, pktin);
5927 if (!ssh->protocol_initial_phase_done) {
5928 if (do_ssh1_login(ssh, in, inlen, pktin))
5929 ssh->protocol_initial_phase_done = TRUE;
5934 do_ssh1_connection(ssh, in, inlen, pktin);
5938 * Utility routine for decoding comma-separated strings in KEXINIT.
5940 static int in_commasep_string(char *needle, char *haystack, int haylen)
5943 if (!needle || !haystack) /* protect against null pointers */
5945 needlen = strlen(needle);
5948 * Is it at the start of the string?
5950 if (haylen >= needlen && /* haystack is long enough */
5951 !memcmp(needle, haystack, needlen) && /* initial match */
5952 (haylen == needlen || haystack[needlen] == ',')
5953 /* either , or EOS follows */
5957 * If not, search for the next comma and resume after that.
5958 * If no comma found, terminate.
5960 while (haylen > 0 && *haystack != ',')
5961 haylen--, haystack++;
5964 haylen--, haystack++; /* skip over comma itself */
5969 * Similar routine for checking whether we have the first string in a list.
5971 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5974 if (!needle || !haystack) /* protect against null pointers */
5976 needlen = strlen(needle);
5978 * Is it at the start of the string?
5980 if (haylen >= needlen && /* haystack is long enough */
5981 !memcmp(needle, haystack, needlen) && /* initial match */
5982 (haylen == needlen || haystack[needlen] == ',')
5983 /* either , or EOS follows */
5991 * SSH-2 key creation method.
5992 * (Currently assumes 2 lots of any hash are sufficient to generate
5993 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5995 #define SSH2_MKKEY_ITERS (2)
5996 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5997 unsigned char *keyspace)
5999 const struct ssh_hash *h = ssh->kex->hash;
6001 /* First hlen bytes. */
6003 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6004 hash_mpint(h, s, K);
6005 h->bytes(s, H, h->hlen);
6006 h->bytes(s, &chr, 1);
6007 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
6008 h->final(s, keyspace);
6009 /* Next hlen bytes. */
6011 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
6012 hash_mpint(h, s, K);
6013 h->bytes(s, H, h->hlen);
6014 h->bytes(s, keyspace, h->hlen);
6015 h->final(s, keyspace + h->hlen);
6019 * Handle the SSH-2 transport layer.
6021 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
6022 struct Packet *pktin)
6024 unsigned char *in = (unsigned char *)vin;
6025 struct do_ssh2_transport_state {
6027 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
6028 Bignum p, g, e, f, K;
6031 int kex_init_value, kex_reply_value;
6032 const struct ssh_mac **maclist;
6034 const struct ssh2_cipher *cscipher_tobe;
6035 const struct ssh2_cipher *sccipher_tobe;
6036 const struct ssh_mac *csmac_tobe;
6037 const struct ssh_mac *scmac_tobe;
6038 const struct ssh_compress *cscomp_tobe;
6039 const struct ssh_compress *sccomp_tobe;
6040 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
6041 int hostkeylen, siglen, rsakeylen;
6042 void *hkey; /* actual host key */
6043 void *rsakey; /* for RSA kex */
6044 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
6045 int n_preferred_kex;
6046 const struct ssh_kexes *preferred_kex[KEX_MAX];
6047 int n_preferred_ciphers;
6048 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
6049 const struct ssh_compress *preferred_comp;
6050 int userauth_succeeded; /* for delayed compression */
6051 int pending_compression;
6052 int got_session_id, activated_authconn;
6053 struct Packet *pktout;
6058 crState(do_ssh2_transport_state);
6060 assert(!ssh->bare_connection);
6064 s->cscipher_tobe = s->sccipher_tobe = NULL;
6065 s->csmac_tobe = s->scmac_tobe = NULL;
6066 s->cscomp_tobe = s->sccomp_tobe = NULL;
6068 s->got_session_id = s->activated_authconn = FALSE;
6069 s->userauth_succeeded = FALSE;
6070 s->pending_compression = FALSE;
6073 * Be prepared to work around the buggy MAC problem.
6075 if (ssh->remote_bugs & BUG_SSH2_HMAC)
6076 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
6078 s->maclist = macs, s->nmacs = lenof(macs);
6081 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
6083 int i, j, k, commalist_started;
6086 * Set up the preferred key exchange. (NULL => warn below here)
6088 s->n_preferred_kex = 0;
6089 for (i = 0; i < KEX_MAX; i++) {
6090 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
6092 s->preferred_kex[s->n_preferred_kex++] =
6093 &ssh_diffiehellman_gex;
6096 s->preferred_kex[s->n_preferred_kex++] =
6097 &ssh_diffiehellman_group14;
6100 s->preferred_kex[s->n_preferred_kex++] =
6101 &ssh_diffiehellman_group1;
6104 s->preferred_kex[s->n_preferred_kex++] =
6108 /* Flag for later. Don't bother if it's the last in
6110 if (i < KEX_MAX - 1) {
6111 s->preferred_kex[s->n_preferred_kex++] = NULL;
6118 * Set up the preferred ciphers. (NULL => warn below here)
6120 s->n_preferred_ciphers = 0;
6121 for (i = 0; i < CIPHER_MAX; i++) {
6122 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
6123 case CIPHER_BLOWFISH:
6124 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
6127 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
6128 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
6132 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
6135 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
6137 case CIPHER_ARCFOUR:
6138 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
6141 /* Flag for later. Don't bother if it's the last in
6143 if (i < CIPHER_MAX - 1) {
6144 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
6151 * Set up preferred compression.
6153 if (conf_get_int(ssh->conf, CONF_compression))
6154 s->preferred_comp = &ssh_zlib;
6156 s->preferred_comp = &ssh_comp_none;
6159 * Enable queueing of outgoing auth- or connection-layer
6160 * packets while we are in the middle of a key exchange.
6162 ssh->queueing = TRUE;
6165 * Flag that KEX is in progress.
6167 ssh->kex_in_progress = TRUE;
6170 * Construct and send our key exchange packet.
6172 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
6173 for (i = 0; i < 16; i++)
6174 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
6175 /* List key exchange algorithms. */
6176 ssh2_pkt_addstring_start(s->pktout);
6177 commalist_started = 0;
6178 for (i = 0; i < s->n_preferred_kex; i++) {
6179 const struct ssh_kexes *k = s->preferred_kex[i];
6180 if (!k) continue; /* warning flag */
6181 for (j = 0; j < k->nkexes; j++) {
6182 if (commalist_started)
6183 ssh2_pkt_addstring_str(s->pktout, ",");
6184 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
6185 commalist_started = 1;
6188 /* List server host key algorithms. */
6189 if (!s->got_session_id) {
6191 * In the first key exchange, we list all the algorithms
6192 * we're prepared to cope with.
6194 ssh2_pkt_addstring_start(s->pktout);
6195 for (i = 0; i < lenof(hostkey_algs); i++) {
6196 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
6197 if (i < lenof(hostkey_algs) - 1)
6198 ssh2_pkt_addstring_str(s->pktout, ",");
6202 * In subsequent key exchanges, we list only the kex
6203 * algorithm that was selected in the first key exchange,
6204 * so that we keep getting the same host key and hence
6205 * don't have to interrupt the user's session to ask for
6209 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
6211 /* List encryption algorithms (client->server then server->client). */
6212 for (k = 0; k < 2; k++) {
6213 ssh2_pkt_addstring_start(s->pktout);
6214 commalist_started = 0;
6215 for (i = 0; i < s->n_preferred_ciphers; i++) {
6216 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6217 if (!c) continue; /* warning flag */
6218 for (j = 0; j < c->nciphers; j++) {
6219 if (commalist_started)
6220 ssh2_pkt_addstring_str(s->pktout, ",");
6221 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
6222 commalist_started = 1;
6226 /* List MAC algorithms (client->server then server->client). */
6227 for (j = 0; j < 2; j++) {
6228 ssh2_pkt_addstring_start(s->pktout);
6229 for (i = 0; i < s->nmacs; i++) {
6230 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
6231 if (i < s->nmacs - 1)
6232 ssh2_pkt_addstring_str(s->pktout, ",");
6235 /* List client->server compression algorithms,
6236 * then server->client compression algorithms. (We use the
6237 * same set twice.) */
6238 for (j = 0; j < 2; j++) {
6239 ssh2_pkt_addstring_start(s->pktout);
6240 assert(lenof(compressions) > 1);
6241 /* Prefer non-delayed versions */
6242 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
6243 /* We don't even list delayed versions of algorithms until
6244 * they're allowed to be used, to avoid a race. See the end of
6246 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
6247 ssh2_pkt_addstring_str(s->pktout, ",");
6248 ssh2_pkt_addstring_str(s->pktout,
6249 s->preferred_comp->delayed_name);
6251 for (i = 0; i < lenof(compressions); i++) {
6252 const struct ssh_compress *c = compressions[i];
6253 if (c != s->preferred_comp) {
6254 ssh2_pkt_addstring_str(s->pktout, ",");
6255 ssh2_pkt_addstring_str(s->pktout, c->name);
6256 if (s->userauth_succeeded && c->delayed_name) {
6257 ssh2_pkt_addstring_str(s->pktout, ",");
6258 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
6263 /* List client->server languages. Empty list. */
6264 ssh2_pkt_addstring_start(s->pktout);
6265 /* List server->client languages. Empty list. */
6266 ssh2_pkt_addstring_start(s->pktout);
6267 /* First KEX packet does _not_ follow, because we're not that brave. */
6268 ssh2_pkt_addbool(s->pktout, FALSE);
6270 ssh2_pkt_adduint32(s->pktout, 0);
6273 s->our_kexinitlen = s->pktout->length - 5;
6274 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
6275 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
6277 ssh2_pkt_send_noqueue(ssh, s->pktout);
6280 crWaitUntilV(pktin);
6283 * Now examine the other side's KEXINIT to see what we're up
6287 char *str, *preferred;
6290 if (pktin->type != SSH2_MSG_KEXINIT) {
6291 bombout(("expected key exchange packet from server"));
6295 ssh->hostkey = NULL;
6296 s->cscipher_tobe = NULL;
6297 s->sccipher_tobe = NULL;
6298 s->csmac_tobe = NULL;
6299 s->scmac_tobe = NULL;
6300 s->cscomp_tobe = NULL;
6301 s->sccomp_tobe = NULL;
6302 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
6304 pktin->savedpos += 16; /* skip garbage cookie */
6305 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
6307 bombout(("KEXINIT packet was incomplete"));
6312 for (i = 0; i < s->n_preferred_kex; i++) {
6313 const struct ssh_kexes *k = s->preferred_kex[i];
6317 for (j = 0; j < k->nkexes; j++) {
6318 if (!preferred) preferred = k->list[j]->name;
6319 if (in_commasep_string(k->list[j]->name, str, len)) {
6320 ssh->kex = k->list[j];
6329 bombout(("Couldn't agree a key exchange algorithm"
6330 " (available: %.*s)", len, str));
6334 * Note that the server's guess is considered wrong if it doesn't match
6335 * the first algorithm in our list, even if it's still the algorithm
6338 s->guessok = first_in_commasep_string(preferred, str, len);
6339 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
6341 bombout(("KEXINIT packet was incomplete"));
6344 for (i = 0; i < lenof(hostkey_algs); i++) {
6345 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
6346 ssh->hostkey = hostkey_algs[i];
6350 if (!ssh->hostkey) {
6351 bombout(("Couldn't agree a host key algorithm"
6352 " (available: %.*s)", len, str));
6356 s->guessok = s->guessok &&
6357 first_in_commasep_string(hostkey_algs[0]->name, str, len);
6358 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
6360 bombout(("KEXINIT packet was incomplete"));
6363 for (i = 0; i < s->n_preferred_ciphers; i++) {
6364 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6366 s->warn_cscipher = TRUE;
6368 for (j = 0; j < c->nciphers; j++) {
6369 if (in_commasep_string(c->list[j]->name, str, len)) {
6370 s->cscipher_tobe = c->list[j];
6375 if (s->cscipher_tobe)
6378 if (!s->cscipher_tobe) {
6379 bombout(("Couldn't agree a client-to-server cipher"
6380 " (available: %.*s)", len, str));
6384 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
6386 bombout(("KEXINIT packet was incomplete"));
6389 for (i = 0; i < s->n_preferred_ciphers; i++) {
6390 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
6392 s->warn_sccipher = TRUE;
6394 for (j = 0; j < c->nciphers; j++) {
6395 if (in_commasep_string(c->list[j]->name, str, len)) {
6396 s->sccipher_tobe = c->list[j];
6401 if (s->sccipher_tobe)
6404 if (!s->sccipher_tobe) {
6405 bombout(("Couldn't agree a server-to-client cipher"
6406 " (available: %.*s)", len, str));
6410 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
6412 bombout(("KEXINIT packet was incomplete"));
6415 for (i = 0; i < s->nmacs; i++) {
6416 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6417 s->csmac_tobe = s->maclist[i];
6421 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
6423 bombout(("KEXINIT packet was incomplete"));
6426 for (i = 0; i < s->nmacs; i++) {
6427 if (in_commasep_string(s->maclist[i]->name, str, len)) {
6428 s->scmac_tobe = s->maclist[i];
6432 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
6434 bombout(("KEXINIT packet was incomplete"));
6437 for (i = 0; i < lenof(compressions) + 1; i++) {
6438 const struct ssh_compress *c =
6439 i == 0 ? s->preferred_comp : compressions[i - 1];
6440 if (in_commasep_string(c->name, str, len)) {
6443 } else if (in_commasep_string(c->delayed_name, str, len)) {
6444 if (s->userauth_succeeded) {
6448 s->pending_compression = TRUE; /* try this later */
6452 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
6454 bombout(("KEXINIT packet was incomplete"));
6457 for (i = 0; i < lenof(compressions) + 1; i++) {
6458 const struct ssh_compress *c =
6459 i == 0 ? s->preferred_comp : compressions[i - 1];
6460 if (in_commasep_string(c->name, str, len)) {
6463 } else if (in_commasep_string(c->delayed_name, str, len)) {
6464 if (s->userauth_succeeded) {
6468 s->pending_compression = TRUE; /* try this later */
6472 if (s->pending_compression) {
6473 logevent("Server supports delayed compression; "
6474 "will try this later");
6476 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
6477 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
6478 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
6480 ssh->exhash = ssh->kex->hash->init();
6481 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
6482 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
6483 hash_string(ssh->kex->hash, ssh->exhash,
6484 s->our_kexinit, s->our_kexinitlen);
6485 sfree(s->our_kexinit);
6486 /* Include the type byte in the hash of server's KEXINIT */
6487 hash_string(ssh->kex->hash, ssh->exhash,
6488 pktin->body - 1, pktin->length + 1);
6491 ssh_set_frozen(ssh, 1);
6492 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
6494 ssh_dialog_callback, ssh);
6495 if (s->dlgret < 0) {
6499 bombout(("Unexpected data from server while"
6500 " waiting for user response"));
6503 } while (pktin || inlen > 0);
6504 s->dlgret = ssh->user_response;
6506 ssh_set_frozen(ssh, 0);
6507 if (s->dlgret == 0) {
6508 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
6514 if (s->warn_cscipher) {
6515 ssh_set_frozen(ssh, 1);
6516 s->dlgret = askalg(ssh->frontend,
6517 "client-to-server cipher",
6518 s->cscipher_tobe->name,
6519 ssh_dialog_callback, ssh);
6520 if (s->dlgret < 0) {
6524 bombout(("Unexpected data from server while"
6525 " waiting for user response"));
6528 } while (pktin || inlen > 0);
6529 s->dlgret = ssh->user_response;
6531 ssh_set_frozen(ssh, 0);
6532 if (s->dlgret == 0) {
6533 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6539 if (s->warn_sccipher) {
6540 ssh_set_frozen(ssh, 1);
6541 s->dlgret = askalg(ssh->frontend,
6542 "server-to-client cipher",
6543 s->sccipher_tobe->name,
6544 ssh_dialog_callback, ssh);
6545 if (s->dlgret < 0) {
6549 bombout(("Unexpected data from server while"
6550 " waiting for user response"));
6553 } while (pktin || inlen > 0);
6554 s->dlgret = ssh->user_response;
6556 ssh_set_frozen(ssh, 0);
6557 if (s->dlgret == 0) {
6558 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6564 if (s->ignorepkt) /* first_kex_packet_follows */
6565 crWaitUntilV(pktin); /* Ignore packet */
6568 if (ssh->kex->main_type == KEXTYPE_DH) {
6570 * Work out the number of bits of key we will need from the
6571 * key exchange. We start with the maximum key length of
6577 csbits = s->cscipher_tobe->keylen;
6578 scbits = s->sccipher_tobe->keylen;
6579 s->nbits = (csbits > scbits ? csbits : scbits);
6581 /* The keys only have hlen-bit entropy, since they're based on
6582 * a hash. So cap the key size at hlen bits. */
6583 if (s->nbits > ssh->kex->hash->hlen * 8)
6584 s->nbits = ssh->kex->hash->hlen * 8;
6587 * If we're doing Diffie-Hellman group exchange, start by
6588 * requesting a group.
6590 if (!ssh->kex->pdata) {
6591 logevent("Doing Diffie-Hellman group exchange");
6592 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6594 * Work out how big a DH group we will need to allow that
6597 s->pbits = 512 << ((s->nbits - 1) / 64);
6598 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6599 ssh2_pkt_adduint32(s->pktout, s->pbits);
6600 ssh2_pkt_send_noqueue(ssh, s->pktout);
6602 crWaitUntilV(pktin);
6603 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6604 bombout(("expected key exchange group packet from server"));
6607 s->p = ssh2_pkt_getmp(pktin);
6608 s->g = ssh2_pkt_getmp(pktin);
6609 if (!s->p || !s->g) {
6610 bombout(("unable to read mp-ints from incoming group packet"));
6613 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6614 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6615 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6617 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6618 ssh->kex_ctx = dh_setup_group(ssh->kex);
6619 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6620 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6621 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6622 ssh->kex->groupname);
6625 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6626 ssh->kex->hash->text_name);
6628 * Now generate and send e for Diffie-Hellman.
6630 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6631 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6632 s->pktout = ssh2_pkt_init(s->kex_init_value);
6633 ssh2_pkt_addmp(s->pktout, s->e);
6634 ssh2_pkt_send_noqueue(ssh, s->pktout);
6636 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6637 crWaitUntilV(pktin);
6638 if (pktin->type != s->kex_reply_value) {
6639 bombout(("expected key exchange reply packet from server"));
6642 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6643 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6644 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6645 s->f = ssh2_pkt_getmp(pktin);
6647 bombout(("unable to parse key exchange reply packet"));
6650 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6653 const char *err = dh_validate_f(ssh->kex_ctx, s->f);
6655 bombout(("key exchange reply failed validation: %s", err));
6659 s->K = dh_find_K(ssh->kex_ctx, s->f);
6661 /* We assume everything from now on will be quick, and it might
6662 * involve user interaction. */
6663 set_busy_status(ssh->frontend, BUSY_NOT);
6665 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6666 if (!ssh->kex->pdata) {
6667 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6668 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6669 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6671 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6672 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6674 dh_cleanup(ssh->kex_ctx);
6676 if (!ssh->kex->pdata) {
6681 logeventf(ssh, "Doing RSA key exchange with hash %s",
6682 ssh->kex->hash->text_name);
6683 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6685 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6688 crWaitUntilV(pktin);
6689 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6690 bombout(("expected RSA public key packet from server"));
6694 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6695 hash_string(ssh->kex->hash, ssh->exhash,
6696 s->hostkeydata, s->hostkeylen);
6697 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6701 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6702 s->rsakeydata = snewn(s->rsakeylen, char);
6703 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6706 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6708 sfree(s->rsakeydata);
6709 bombout(("unable to parse RSA public key from server"));
6713 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6716 * Next, set up a shared secret K, of precisely KLEN -
6717 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6718 * RSA key modulus and HLEN is the bit length of the hash
6722 int klen = ssh_rsakex_klen(s->rsakey);
6723 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6725 unsigned char *kstr1, *kstr2, *outstr;
6726 int kstr1len, kstr2len, outstrlen;
6728 s->K = bn_power_2(nbits - 1);
6730 for (i = 0; i < nbits; i++) {
6732 byte = random_byte();
6734 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6738 * Encode this as an mpint.
6740 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6741 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6742 PUT_32BIT(kstr2, kstr1len);
6743 memcpy(kstr2 + 4, kstr1, kstr1len);
6746 * Encrypt it with the given RSA key.
6748 outstrlen = (klen + 7) / 8;
6749 outstr = snewn(outstrlen, unsigned char);
6750 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6751 outstr, outstrlen, s->rsakey);
6754 * And send it off in a return packet.
6756 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6757 ssh2_pkt_addstring_start(s->pktout);
6758 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6759 ssh2_pkt_send_noqueue(ssh, s->pktout);
6761 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6768 ssh_rsakex_freekey(s->rsakey);
6770 crWaitUntilV(pktin);
6771 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6772 sfree(s->rsakeydata);
6773 bombout(("expected signature packet from server"));
6777 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6779 sfree(s->rsakeydata);
6782 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6783 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6784 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6786 ssh->kex_ctx = NULL;
6789 debug(("Exchange hash is:\n"));
6790 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6794 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6795 (char *)s->exchange_hash,
6796 ssh->kex->hash->hlen)) {
6797 bombout(("Server's host key did not match the signature supplied"));
6801 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6802 if (!s->got_session_id) {
6804 * Authenticate remote host: verify host key. (We've already
6805 * checked the signature of the exchange hash.)
6807 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6808 logevent("Host key fingerprint is:");
6809 logevent(s->fingerprint);
6810 /* First check against manually configured host keys. */
6811 s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
6812 ssh->hostkey, s->hkey);
6813 if (s->dlgret == 0) { /* did not match */
6814 bombout(("Host key did not appear in manually configured list"));
6816 } else if (s->dlgret < 0) { /* none configured; use standard handling */
6817 ssh_set_frozen(ssh, 1);
6818 s->dlgret = verify_ssh_host_key(ssh->frontend,
6819 ssh->savedhost, ssh->savedport,
6820 ssh->hostkey->keytype, s->keystr,
6822 ssh_dialog_callback, ssh);
6823 if (s->dlgret < 0) {
6827 bombout(("Unexpected data from server while waiting"
6828 " for user host key response"));
6831 } while (pktin || inlen > 0);
6832 s->dlgret = ssh->user_response;
6834 ssh_set_frozen(ssh, 0);
6835 if (s->dlgret == 0) {
6836 ssh_disconnect(ssh, "Aborted at host key verification", NULL,
6841 sfree(s->fingerprint);
6843 * Save this host key, to check against the one presented in
6844 * subsequent rekeys.
6846 ssh->hostkey_str = s->keystr;
6849 * In a rekey, we never present an interactive host key
6850 * verification request to the user. Instead, we simply
6851 * enforce that the key we're seeing this time is identical to
6852 * the one we saw before.
6854 if (strcmp(ssh->hostkey_str, s->keystr)) {
6855 bombout(("Host key was different in repeat key exchange"));
6860 ssh->hostkey->freekey(s->hkey);
6863 * The exchange hash from the very first key exchange is also
6864 * the session id, used in session key construction and
6867 if (!s->got_session_id) {
6868 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6869 memcpy(ssh->v2_session_id, s->exchange_hash,
6870 sizeof(s->exchange_hash));
6871 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6872 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6873 s->got_session_id = TRUE;
6877 * Send SSH2_MSG_NEWKEYS.
6879 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6880 ssh2_pkt_send_noqueue(ssh, s->pktout);
6881 ssh->outgoing_data_size = 0; /* start counting from here */
6884 * We've sent client NEWKEYS, so create and initialise
6885 * client-to-server session keys.
6887 if (ssh->cs_cipher_ctx)
6888 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6889 ssh->cscipher = s->cscipher_tobe;
6890 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6892 if (ssh->cs_mac_ctx)
6893 ssh->csmac->free_context(ssh->cs_mac_ctx);
6894 ssh->csmac = s->csmac_tobe;
6895 ssh->cs_mac_ctx = ssh->csmac->make_context();
6897 if (ssh->cs_comp_ctx)
6898 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6899 ssh->cscomp = s->cscomp_tobe;
6900 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6903 * Set IVs on client-to-server keys. Here we use the exchange
6904 * hash from the _first_ key exchange.
6907 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6908 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6909 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6910 assert((ssh->cscipher->keylen+7) / 8 <=
6911 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6912 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6913 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6914 assert(ssh->cscipher->blksize <=
6915 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6916 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6917 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6918 assert(ssh->csmac->len <=
6919 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6920 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6921 smemclr(keyspace, sizeof(keyspace));
6924 logeventf(ssh, "Initialised %.200s client->server encryption",
6925 ssh->cscipher->text_name);
6926 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6927 ssh->csmac->text_name);
6928 if (ssh->cscomp->text_name)
6929 logeventf(ssh, "Initialised %s compression",
6930 ssh->cscomp->text_name);
6933 * Now our end of the key exchange is complete, we can send all
6934 * our queued higher-layer packets.
6936 ssh->queueing = FALSE;
6937 ssh2_pkt_queuesend(ssh);
6940 * Expect SSH2_MSG_NEWKEYS from server.
6942 crWaitUntilV(pktin);
6943 if (pktin->type != SSH2_MSG_NEWKEYS) {
6944 bombout(("expected new-keys packet from server"));
6947 ssh->incoming_data_size = 0; /* start counting from here */
6950 * We've seen server NEWKEYS, so create and initialise
6951 * server-to-client session keys.
6953 if (ssh->sc_cipher_ctx)
6954 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6955 ssh->sccipher = s->sccipher_tobe;
6956 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6958 if (ssh->sc_mac_ctx)
6959 ssh->scmac->free_context(ssh->sc_mac_ctx);
6960 ssh->scmac = s->scmac_tobe;
6961 ssh->sc_mac_ctx = ssh->scmac->make_context();
6963 if (ssh->sc_comp_ctx)
6964 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6965 ssh->sccomp = s->sccomp_tobe;
6966 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6969 * Set IVs on server-to-client keys. Here we use the exchange
6970 * hash from the _first_ key exchange.
6973 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6974 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6975 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6976 assert((ssh->sccipher->keylen+7) / 8 <=
6977 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6978 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6979 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6980 assert(ssh->sccipher->blksize <=
6981 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6982 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6983 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6984 assert(ssh->scmac->len <=
6985 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6986 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6987 smemclr(keyspace, sizeof(keyspace));
6989 logeventf(ssh, "Initialised %.200s server->client encryption",
6990 ssh->sccipher->text_name);
6991 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6992 ssh->scmac->text_name);
6993 if (ssh->sccomp->text_name)
6994 logeventf(ssh, "Initialised %s decompression",
6995 ssh->sccomp->text_name);
6998 * Free shared secret.
7003 * Key exchange is over. Loop straight back round if we have a
7004 * deferred rekey reason.
7006 if (ssh->deferred_rekey_reason) {
7007 logevent(ssh->deferred_rekey_reason);
7009 ssh->deferred_rekey_reason = NULL;
7010 goto begin_key_exchange;
7014 * Otherwise, schedule a timer for our next rekey.
7016 ssh->kex_in_progress = FALSE;
7017 ssh->last_rekey = GETTICKCOUNT();
7018 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
7019 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7023 * Now we're encrypting. Begin returning 1 to the protocol main
7024 * function so that other things can run on top of the
7025 * transport. If we ever see a KEXINIT, we must go back to the
7028 * We _also_ go back to the start if we see pktin==NULL and
7029 * inlen negative, because this is a special signal meaning
7030 * `initiate client-driven rekey', and `in' contains a message
7031 * giving the reason for the rekey.
7033 * inlen==-1 means always initiate a rekey;
7034 * inlen==-2 means that userauth has completed successfully and
7035 * we should consider rekeying (for delayed compression).
7037 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
7038 (!pktin && inlen < 0))) {
7040 if (!ssh->protocol_initial_phase_done) {
7041 ssh->protocol_initial_phase_done = TRUE;
7043 * Allow authconn to initialise itself.
7045 do_ssh2_authconn(ssh, NULL, 0, NULL);
7050 logevent("Server initiated key re-exchange");
7054 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
7055 * delayed compression, if it's available.
7057 * draft-miller-secsh-compression-delayed-00 says that you
7058 * negotiate delayed compression in the first key exchange, and
7059 * both sides start compressing when the server has sent
7060 * USERAUTH_SUCCESS. This has a race condition -- the server
7061 * can't know when the client has seen it, and thus which incoming
7062 * packets it should treat as compressed.
7064 * Instead, we do the initial key exchange without offering the
7065 * delayed methods, but note if the server offers them; when we
7066 * get here, if a delayed method was available that was higher
7067 * on our list than what we got, we initiate a rekey in which we
7068 * _do_ list the delayed methods (and hopefully get it as a
7069 * result). Subsequent rekeys will do the same.
7071 assert(!s->userauth_succeeded); /* should only happen once */
7072 s->userauth_succeeded = TRUE;
7073 if (!s->pending_compression)
7074 /* Can't see any point rekeying. */
7075 goto wait_for_rekey; /* this is utterly horrid */
7076 /* else fall through to rekey... */
7077 s->pending_compression = FALSE;
7080 * Now we've decided to rekey.
7082 * Special case: if the server bug is set that doesn't
7083 * allow rekeying, we give a different log message and
7084 * continue waiting. (If such a server _initiates_ a rekey,
7085 * we process it anyway!)
7087 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
7088 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
7090 /* Reset the counters, so that at least this message doesn't
7091 * hit the event log _too_ often. */
7092 ssh->outgoing_data_size = 0;
7093 ssh->incoming_data_size = 0;
7094 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
7096 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
7099 goto wait_for_rekey; /* this is still utterly horrid */
7101 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
7104 goto begin_key_exchange;
7110 * Add data to an SSH-2 channel output buffer.
7112 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
7115 bufchain_add(&c->v.v2.outbuffer, buf, len);
7119 * Attempt to send data on an SSH-2 channel.
7121 static int ssh2_try_send(struct ssh_channel *c)
7124 struct Packet *pktout;
7127 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
7130 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
7131 if ((unsigned)len > c->v.v2.remwindow)
7132 len = c->v.v2.remwindow;
7133 if ((unsigned)len > c->v.v2.remmaxpkt)
7134 len = c->v.v2.remmaxpkt;
7135 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
7136 ssh2_pkt_adduint32(pktout, c->remoteid);
7137 ssh2_pkt_addstring_start(pktout);
7138 ssh2_pkt_addstring_data(pktout, data, len);
7139 ssh2_pkt_send(ssh, pktout);
7140 bufchain_consume(&c->v.v2.outbuffer, len);
7141 c->v.v2.remwindow -= len;
7145 * After having sent as much data as we can, return the amount
7148 ret = bufchain_size(&c->v.v2.outbuffer);
7151 * And if there's no data pending but we need to send an EOF, send
7154 if (!ret && c->pending_eof)
7155 ssh_channel_try_eof(c);
7160 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
7163 if (c->closes & CLOSES_SENT_EOF)
7164 return; /* don't send on channels we've EOFed */
7165 bufsize = ssh2_try_send(c);
7168 case CHAN_MAINSESSION:
7169 /* stdin need not receive an unthrottle
7170 * notification since it will be polled */
7173 x11_unthrottle(c->u.x11.xconn);
7176 /* agent sockets are request/response and need no
7177 * buffer management */
7180 pfd_unthrottle(c->u.pfd.pf);
7186 static int ssh_is_simple(Ssh ssh)
7189 * We use the 'simple' variant of the SSH protocol if we're asked
7190 * to, except not if we're also doing connection-sharing (either
7191 * tunnelling our packets over an upstream or expecting to be
7192 * tunnelled over ourselves), since then the assumption that we
7193 * have only one channel to worry about is not true after all.
7195 return (conf_get_int(ssh->conf, CONF_ssh_simple) &&
7196 !ssh->bare_connection && !ssh->connshare);
7200 * Set up most of a new ssh_channel for SSH-2.
7202 static void ssh2_channel_init(struct ssh_channel *c)
7205 c->localid = alloc_channel_id(ssh);
7207 c->pending_eof = FALSE;
7208 c->throttling_conn = FALSE;
7209 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
7210 ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7211 c->v.v2.chanreq_head = NULL;
7212 c->v.v2.throttle_state = UNTHROTTLED;
7213 bufchain_init(&c->v.v2.outbuffer);
7217 * Construct the common parts of a CHANNEL_OPEN.
7219 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
7221 struct Packet *pktout;
7223 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7224 ssh2_pkt_addstring(pktout, type);
7225 ssh2_pkt_adduint32(pktout, c->localid);
7226 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7227 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7232 * CHANNEL_FAILURE doesn't come with any indication of what message
7233 * caused it, so we have to keep track of the outstanding
7234 * CHANNEL_REQUESTs ourselves.
7236 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
7237 cchandler_fn_t handler, void *ctx)
7239 struct outstanding_channel_request *ocr =
7240 snew(struct outstanding_channel_request);
7242 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7243 ocr->handler = handler;
7246 if (!c->v.v2.chanreq_head)
7247 c->v.v2.chanreq_head = ocr;
7249 c->v.v2.chanreq_tail->next = ocr;
7250 c->v.v2.chanreq_tail = ocr;
7254 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
7255 * NULL then a reply will be requested and the handler will be called
7256 * when it arrives. The returned packet is ready to have any
7257 * request-specific data added and be sent. Note that if a handler is
7258 * provided, it's essential that the request actually be sent.
7260 * The handler will usually be passed the response packet in pktin. If
7261 * pktin is NULL, this means that no reply will ever be forthcoming
7262 * (e.g. because the entire connection is being destroyed, or because
7263 * the server initiated channel closure before we saw the response)
7264 * and the handler should free any storage it's holding.
7266 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
7267 cchandler_fn_t handler, void *ctx)
7269 struct Packet *pktout;
7271 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
7272 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7273 ssh2_pkt_adduint32(pktout, c->remoteid);
7274 ssh2_pkt_addstring(pktout, type);
7275 ssh2_pkt_addbool(pktout, handler != NULL);
7276 if (handler != NULL)
7277 ssh2_queue_chanreq_handler(c, handler, ctx);
7282 * Potentially enlarge the window on an SSH-2 channel.
7284 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
7286 static void ssh2_set_window(struct ssh_channel *c, int newwin)
7291 * Never send WINDOW_ADJUST for a channel that the remote side has
7292 * already sent EOF on; there's no point, since it won't be
7293 * sending any more data anyway. Ditto if _we've_ already sent
7296 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
7300 * Also, never widen the window for an X11 channel when we're
7301 * still waiting to see its initial auth and may yet hand it off
7304 if (c->type == CHAN_X11 && c->u.x11.initial)
7308 * If the remote end has a habit of ignoring maxpkt, limit the
7309 * window so that it has no choice (assuming it doesn't ignore the
7312 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
7313 newwin = OUR_V2_MAXPKT;
7316 * Only send a WINDOW_ADJUST if there's significantly more window
7317 * available than the other end thinks there is. This saves us
7318 * sending a WINDOW_ADJUST for every character in a shell session.
7320 * "Significant" is arbitrarily defined as half the window size.
7322 if (newwin / 2 >= c->v.v2.locwindow) {
7323 struct Packet *pktout;
7327 * In order to keep track of how much window the client
7328 * actually has available, we'd like it to acknowledge each
7329 * WINDOW_ADJUST. We can't do that directly, so we accompany
7330 * it with a CHANNEL_REQUEST that has to be acknowledged.
7332 * This is only necessary if we're opening the window wide.
7333 * If we're not, then throughput is being constrained by
7334 * something other than the maximum window size anyway.
7336 if (newwin == c->v.v2.locmaxwin &&
7337 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
7338 up = snew(unsigned);
7339 *up = newwin - c->v.v2.locwindow;
7340 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
7341 ssh2_handle_winadj_response, up);
7342 ssh2_pkt_send(ssh, pktout);
7344 if (c->v.v2.throttle_state != UNTHROTTLED)
7345 c->v.v2.throttle_state = UNTHROTTLING;
7347 /* Pretend the WINDOW_ADJUST was acked immediately. */
7348 c->v.v2.remlocwin = newwin;
7349 c->v.v2.throttle_state = THROTTLED;
7351 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7352 ssh2_pkt_adduint32(pktout, c->remoteid);
7353 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
7354 ssh2_pkt_send(ssh, pktout);
7355 c->v.v2.locwindow = newwin;
7360 * Find the channel associated with a message. If there's no channel,
7361 * or it's not properly open, make a noise about it and return NULL.
7363 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
7365 unsigned localid = ssh_pkt_getuint32(pktin);
7366 struct ssh_channel *c;
7368 c = find234(ssh->channels, &localid, ssh_channelfind);
7370 (c->type != CHAN_SHARING && c->halfopen &&
7371 pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
7372 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
7373 char *buf = dupprintf("Received %s for %s channel %u",
7374 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
7376 c ? "half-open" : "nonexistent", localid);
7377 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
7384 static void ssh2_handle_winadj_response(struct ssh_channel *c,
7385 struct Packet *pktin, void *ctx)
7387 unsigned *sizep = ctx;
7390 * Winadj responses should always be failures. However, at least
7391 * one server ("boks_sshd") is known to return SUCCESS for channel
7392 * requests it's never heard of, such as "winadj@putty". Raised
7393 * with foxt.com as bug 090916-090424, but for the sake of a quiet
7394 * life, we don't worry about what kind of response we got.
7397 c->v.v2.remlocwin += *sizep;
7400 * winadj messages are only sent when the window is fully open, so
7401 * if we get an ack of one, we know any pending unthrottle is
7404 if (c->v.v2.throttle_state == UNTHROTTLING)
7405 c->v.v2.throttle_state = UNTHROTTLED;
7408 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
7410 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
7411 struct outstanding_channel_request *ocr;
7414 if (c->type == CHAN_SHARING) {
7415 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7416 pktin->body, pktin->length);
7419 ocr = c->v.v2.chanreq_head;
7421 ssh2_msg_unexpected(ssh, pktin);
7424 ocr->handler(c, pktin, ocr->ctx);
7425 c->v.v2.chanreq_head = ocr->next;
7428 * We may now initiate channel-closing procedures, if that
7429 * CHANNEL_REQUEST was the last thing outstanding before we send
7432 ssh2_channel_check_close(c);
7435 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
7437 struct ssh_channel *c;
7438 c = ssh2_channel_msg(ssh, pktin);
7441 if (c->type == CHAN_SHARING) {
7442 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7443 pktin->body, pktin->length);
7446 if (!(c->closes & CLOSES_SENT_EOF)) {
7447 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
7448 ssh2_try_send_and_unthrottle(ssh, c);
7452 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
7456 struct ssh_channel *c;
7457 c = ssh2_channel_msg(ssh, pktin);
7460 if (c->type == CHAN_SHARING) {
7461 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7462 pktin->body, pktin->length);
7465 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
7466 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
7467 return; /* extended but not stderr */
7468 ssh_pkt_getstring(pktin, &data, &length);
7471 c->v.v2.locwindow -= length;
7472 c->v.v2.remlocwin -= length;
7474 case CHAN_MAINSESSION:
7476 from_backend(ssh->frontend, pktin->type ==
7477 SSH2_MSG_CHANNEL_EXTENDED_DATA,
7481 bufsize = x11_send(c->u.x11.xconn, data, length);
7484 bufsize = pfd_send(c->u.pfd.pf, data, length);
7487 while (length > 0) {
7488 if (c->u.a.lensofar < 4) {
7489 unsigned int l = min(4 - c->u.a.lensofar,
7491 memcpy(c->u.a.msglen + c->u.a.lensofar,
7495 c->u.a.lensofar += l;
7497 if (c->u.a.lensofar == 4) {
7499 4 + GET_32BIT(c->u.a.msglen);
7500 c->u.a.message = snewn(c->u.a.totallen,
7502 memcpy(c->u.a.message, c->u.a.msglen, 4);
7504 if (c->u.a.lensofar >= 4 && length > 0) {
7506 min(c->u.a.totallen - c->u.a.lensofar,
7508 memcpy(c->u.a.message + c->u.a.lensofar,
7512 c->u.a.lensofar += l;
7514 if (c->u.a.lensofar == c->u.a.totallen) {
7517 c->u.a.outstanding_requests++;
7518 if (agent_query(c->u.a.message,
7521 ssh_agentf_callback, c))
7522 ssh_agentf_callback(c, reply, replylen);
7523 sfree(c->u.a.message);
7524 c->u.a.message = NULL;
7525 c->u.a.lensofar = 0;
7532 * If it looks like the remote end hit the end of its window,
7533 * and we didn't want it to do that, think about using a
7536 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
7537 c->v.v2.locmaxwin < 0x40000000)
7538 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
7540 * If we are not buffering too much data,
7541 * enlarge the window again at the remote side.
7542 * If we are buffering too much, we may still
7543 * need to adjust the window if the server's
7546 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
7547 c->v.v2.locmaxwin - bufsize : 0);
7549 * If we're either buffering way too much data, or if we're
7550 * buffering anything at all and we're in "simple" mode,
7551 * throttle the whole channel.
7553 if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0))
7554 && !c->throttling_conn) {
7555 c->throttling_conn = 1;
7556 ssh_throttle_conn(ssh, +1);
7561 static void ssh_check_termination(Ssh ssh)
7563 if (ssh->version == 2 &&
7564 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7565 count234(ssh->channels) == 0 &&
7566 !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) {
7568 * We used to send SSH_MSG_DISCONNECT here, because I'd
7569 * believed that _every_ conforming SSH-2 connection had to
7570 * end with a disconnect being sent by at least one side;
7571 * apparently I was wrong and it's perfectly OK to
7572 * unceremoniously slam the connection shut when you're done,
7573 * and indeed OpenSSH feels this is more polite than sending a
7574 * DISCONNECT. So now we don't.
7576 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7580 void ssh_sharing_downstream_connected(Ssh ssh, unsigned id)
7582 logeventf(ssh, "Connection sharing downstream #%u connected", id);
7585 void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id)
7587 logeventf(ssh, "Connection sharing downstream #%u disconnected", id);
7588 ssh_check_termination(ssh);
7591 void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...)
7596 va_start(ap, logfmt);
7597 buf = dupvprintf(logfmt, ap);
7600 logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf);
7602 logeventf(ssh, "Connection sharing: %s", buf);
7606 static void ssh_channel_destroy(struct ssh_channel *c)
7611 case CHAN_MAINSESSION:
7612 ssh->mainchan = NULL;
7613 update_specials_menu(ssh->frontend);
7616 if (c->u.x11.xconn != NULL)
7617 x11_close(c->u.x11.xconn);
7618 logevent("Forwarded X11 connection terminated");
7621 sfree(c->u.a.message);
7624 if (c->u.pfd.pf != NULL)
7625 pfd_close(c->u.pfd.pf);
7626 logevent("Forwarded port closed");
7630 del234(ssh->channels, c);
7631 if (ssh->version == 2) {
7632 bufchain_clear(&c->v.v2.outbuffer);
7633 assert(c->v.v2.chanreq_head == NULL);
7638 * If that was the last channel left open, we might need to
7641 ssh_check_termination(ssh);
7644 static void ssh2_channel_check_close(struct ssh_channel *c)
7647 struct Packet *pktout;
7651 * If we've sent out our own CHANNEL_OPEN but not yet seen
7652 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7653 * it's too early to be sending close messages of any kind.
7658 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7659 c->type == CHAN_ZOMBIE) &&
7660 !c->v.v2.chanreq_head &&
7661 !(c->closes & CLOSES_SENT_CLOSE)) {
7663 * We have both sent and received EOF (or the channel is a
7664 * zombie), and we have no outstanding channel requests, which
7665 * means the channel is in final wind-up. But we haven't sent
7666 * CLOSE, so let's do so now.
7668 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7669 ssh2_pkt_adduint32(pktout, c->remoteid);
7670 ssh2_pkt_send(ssh, pktout);
7671 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7674 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7675 assert(c->v.v2.chanreq_head == NULL);
7677 * We have both sent and received CLOSE, which means we're
7678 * completely done with the channel.
7680 ssh_channel_destroy(c);
7684 static void ssh2_channel_got_eof(struct ssh_channel *c)
7686 if (c->closes & CLOSES_RCVD_EOF)
7687 return; /* already seen EOF */
7688 c->closes |= CLOSES_RCVD_EOF;
7690 if (c->type == CHAN_X11) {
7691 x11_send_eof(c->u.x11.xconn);
7692 } else if (c->type == CHAN_AGENT) {
7693 if (c->u.a.outstanding_requests == 0) {
7694 /* Manufacture an outgoing EOF in response to the incoming one. */
7695 sshfwd_write_eof(c);
7697 } else if (c->type == CHAN_SOCKDATA) {
7698 pfd_send_eof(c->u.pfd.pf);
7699 } else if (c->type == CHAN_MAINSESSION) {
7702 if (!ssh->sent_console_eof &&
7703 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7705 * Either from_backend_eof told us that the front end
7706 * wants us to close the outgoing side of the connection
7707 * as soon as we see EOF from the far end, or else we've
7708 * unilaterally decided to do that because we've allocated
7709 * a remote pty and hence EOF isn't a particularly
7710 * meaningful concept.
7712 sshfwd_write_eof(c);
7714 ssh->sent_console_eof = TRUE;
7717 ssh2_channel_check_close(c);
7720 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7722 struct ssh_channel *c;
7724 c = ssh2_channel_msg(ssh, pktin);
7727 if (c->type == CHAN_SHARING) {
7728 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7729 pktin->body, pktin->length);
7732 ssh2_channel_got_eof(c);
7735 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7737 struct ssh_channel *c;
7739 c = ssh2_channel_msg(ssh, pktin);
7742 if (c->type == CHAN_SHARING) {
7743 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7744 pktin->body, pktin->length);
7749 * When we receive CLOSE on a channel, we assume it comes with an
7750 * implied EOF if we haven't seen EOF yet.
7752 ssh2_channel_got_eof(c);
7754 if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
7756 * It also means we stop expecting to see replies to any
7757 * outstanding channel requests, so clean those up too.
7758 * (ssh_chanreq_init will enforce by assertion that we don't
7759 * subsequently put anything back on this list.)
7761 while (c->v.v2.chanreq_head) {
7762 struct outstanding_channel_request *ocr = c->v.v2.chanreq_head;
7763 ocr->handler(c, NULL, ocr->ctx);
7764 c->v.v2.chanreq_head = ocr->next;
7770 * And we also send an outgoing EOF, if we haven't already, on the
7771 * assumption that CLOSE is a pretty forceful announcement that
7772 * the remote side is doing away with the entire channel. (If it
7773 * had wanted to send us EOF and continue receiving data from us,
7774 * it would have just sent CHANNEL_EOF.)
7776 if (!(c->closes & CLOSES_SENT_EOF)) {
7778 * Make sure we don't read any more from whatever our local
7779 * data source is for this channel.
7782 case CHAN_MAINSESSION:
7783 ssh->send_ok = 0; /* stop trying to read from stdin */
7786 x11_override_throttle(c->u.x11.xconn, 1);
7789 pfd_override_throttle(c->u.pfd.pf, 1);
7794 * Abandon any buffered data we still wanted to send to this
7795 * channel. Receiving a CHANNEL_CLOSE is an indication that
7796 * the server really wants to get on and _destroy_ this
7797 * channel, and it isn't going to send us any further
7798 * WINDOW_ADJUSTs to permit us to send pending stuff.
7800 bufchain_clear(&c->v.v2.outbuffer);
7803 * Send outgoing EOF.
7805 sshfwd_write_eof(c);
7809 * Now process the actual close.
7811 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7812 c->closes |= CLOSES_RCVD_CLOSE;
7813 ssh2_channel_check_close(c);
7817 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7819 struct ssh_channel *c;
7821 c = ssh2_channel_msg(ssh, pktin);
7824 if (c->type == CHAN_SHARING) {
7825 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7826 pktin->body, pktin->length);
7829 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7830 c->remoteid = ssh_pkt_getuint32(pktin);
7831 c->halfopen = FALSE;
7832 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7833 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7835 if (c->type == CHAN_SOCKDATA_DORMANT) {
7836 c->type = CHAN_SOCKDATA;
7838 pfd_confirm(c->u.pfd.pf);
7839 } else if (c->type == CHAN_ZOMBIE) {
7841 * This case can occur if a local socket error occurred
7842 * between us sending out CHANNEL_OPEN and receiving
7843 * OPEN_CONFIRMATION. In this case, all we can do is
7844 * immediately initiate close proceedings now that we know the
7845 * server's id to put in the close message.
7847 ssh2_channel_check_close(c);
7850 * We never expect to receive OPEN_CONFIRMATION for any
7851 * *other* channel type (since only local-to-remote port
7852 * forwardings cause us to send CHANNEL_OPEN after the main
7853 * channel is live - all other auxiliary channel types are
7854 * initiated from the server end). It's safe to enforce this
7855 * by assertion rather than by ssh_disconnect, because the
7856 * real point is that we never constructed a half-open channel
7857 * structure in the first place with any type other than the
7860 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7864 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7867 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7869 static const char *const reasons[] = {
7870 "<unknown reason code>",
7871 "Administratively prohibited",
7873 "Unknown channel type",
7874 "Resource shortage",
7876 unsigned reason_code;
7877 char *reason_string;
7879 struct ssh_channel *c;
7881 c = ssh2_channel_msg(ssh, pktin);
7884 if (c->type == CHAN_SHARING) {
7885 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7886 pktin->body, pktin->length);
7889 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7891 if (c->type == CHAN_SOCKDATA_DORMANT) {
7892 reason_code = ssh_pkt_getuint32(pktin);
7893 if (reason_code >= lenof(reasons))
7894 reason_code = 0; /* ensure reasons[reason_code] in range */
7895 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7896 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7897 reasons[reason_code], reason_length, reason_string);
7899 pfd_close(c->u.pfd.pf);
7900 } else if (c->type == CHAN_ZOMBIE) {
7902 * This case can occur if a local socket error occurred
7903 * between us sending out CHANNEL_OPEN and receiving
7904 * OPEN_FAILURE. In this case, we need do nothing except allow
7905 * the code below to throw the half-open channel away.
7909 * We never expect to receive OPEN_FAILURE for any *other*
7910 * channel type (since only local-to-remote port forwardings
7911 * cause us to send CHANNEL_OPEN after the main channel is
7912 * live - all other auxiliary channel types are initiated from
7913 * the server end). It's safe to enforce this by assertion
7914 * rather than by ssh_disconnect, because the real point is
7915 * that we never constructed a half-open channel structure in
7916 * the first place with any type other than the above.
7918 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7921 del234(ssh->channels, c);
7925 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7928 int typelen, want_reply;
7929 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7930 struct ssh_channel *c;
7931 struct Packet *pktout;
7933 c = ssh2_channel_msg(ssh, pktin);
7936 if (c->type == CHAN_SHARING) {
7937 share_got_pkt_from_server(c->u.sharing.ctx, pktin->type,
7938 pktin->body, pktin->length);
7941 ssh_pkt_getstring(pktin, &type, &typelen);
7942 want_reply = ssh2_pkt_getbool(pktin);
7944 if (c->closes & CLOSES_SENT_CLOSE) {
7946 * We don't reply to channel requests after we've sent
7947 * CHANNEL_CLOSE for the channel, because our reply might
7948 * cross in the network with the other side's CHANNEL_CLOSE
7949 * and arrive after they have wound the channel up completely.
7955 * Having got the channel number, we now look at
7956 * the request type string to see if it's something
7959 if (c == ssh->mainchan) {
7961 * We recognise "exit-status" and "exit-signal" on
7962 * the primary channel.
7964 if (typelen == 11 &&
7965 !memcmp(type, "exit-status", 11)) {
7967 ssh->exitcode = ssh_pkt_getuint32(pktin);
7968 logeventf(ssh, "Server sent command exit status %d",
7970 reply = SSH2_MSG_CHANNEL_SUCCESS;
7972 } else if (typelen == 11 &&
7973 !memcmp(type, "exit-signal", 11)) {
7975 int is_plausible = TRUE, is_int = FALSE;
7976 char *fmt_sig = "", *fmt_msg = "";
7978 int msglen = 0, core = FALSE;
7979 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7980 * provide an `int' for the signal, despite its
7981 * having been a `string' in the drafts of RFC 4254 since at
7982 * least 2001. (Fixed in session.c 1.147.) Try to
7983 * infer which we can safely parse it as. */
7985 unsigned char *p = pktin->body +
7987 long len = pktin->length - pktin->savedpos;
7988 unsigned long num = GET_32BIT(p); /* what is it? */
7989 /* If it's 0, it hardly matters; assume string */
7993 int maybe_int = FALSE, maybe_str = FALSE;
7994 #define CHECK_HYPOTHESIS(offset, result) \
7997 int q = toint(offset); \
7998 if (q >= 0 && q+4 <= len) { \
7999 q = toint(q + 4 + GET_32BIT(p+q)); \
8000 if (q >= 0 && q+4 <= len && \
8001 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
8006 CHECK_HYPOTHESIS(4+1, maybe_int);
8007 CHECK_HYPOTHESIS(4+num+1, maybe_str);
8008 #undef CHECK_HYPOTHESIS
8009 if (maybe_int && !maybe_str)
8011 else if (!maybe_int && maybe_str)
8014 /* Crikey. Either or neither. Panic. */
8015 is_plausible = FALSE;
8018 ssh->exitcode = 128; /* means `unknown signal' */
8021 /* Old non-standard OpenSSH. */
8022 int signum = ssh_pkt_getuint32(pktin);
8023 fmt_sig = dupprintf(" %d", signum);
8024 ssh->exitcode = 128 + signum;
8026 /* As per RFC 4254. */
8029 ssh_pkt_getstring(pktin, &sig, &siglen);
8030 /* Signal name isn't supposed to be blank, but
8031 * let's cope gracefully if it is. */
8033 fmt_sig = dupprintf(" \"%.*s\"",
8038 * Really hideous method of translating the
8039 * signal description back into a locally
8040 * meaningful number.
8045 #define TRANSLATE_SIGNAL(s) \
8046 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
8047 ssh->exitcode = 128 + SIG ## s
8049 TRANSLATE_SIGNAL(ABRT);
8052 TRANSLATE_SIGNAL(ALRM);
8055 TRANSLATE_SIGNAL(FPE);
8058 TRANSLATE_SIGNAL(HUP);
8061 TRANSLATE_SIGNAL(ILL);
8064 TRANSLATE_SIGNAL(INT);
8067 TRANSLATE_SIGNAL(KILL);
8070 TRANSLATE_SIGNAL(PIPE);
8073 TRANSLATE_SIGNAL(QUIT);
8076 TRANSLATE_SIGNAL(SEGV);
8079 TRANSLATE_SIGNAL(TERM);
8082 TRANSLATE_SIGNAL(USR1);
8085 TRANSLATE_SIGNAL(USR2);
8087 #undef TRANSLATE_SIGNAL
8089 ssh->exitcode = 128;
8091 core = ssh2_pkt_getbool(pktin);
8092 ssh_pkt_getstring(pktin, &msg, &msglen);
8094 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
8096 /* ignore lang tag */
8097 } /* else don't attempt to parse */
8098 logeventf(ssh, "Server exited on signal%s%s%s",
8099 fmt_sig, core ? " (core dumped)" : "",
8101 if (*fmt_sig) sfree(fmt_sig);
8102 if (*fmt_msg) sfree(fmt_msg);
8103 reply = SSH2_MSG_CHANNEL_SUCCESS;
8108 * This is a channel request we don't know
8109 * about, so we now either ignore the request
8110 * or respond with CHANNEL_FAILURE, depending
8113 reply = SSH2_MSG_CHANNEL_FAILURE;
8116 pktout = ssh2_pkt_init(reply);
8117 ssh2_pkt_adduint32(pktout, c->remoteid);
8118 ssh2_pkt_send(ssh, pktout);
8122 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
8125 int typelen, want_reply;
8126 struct Packet *pktout;
8128 ssh_pkt_getstring(pktin, &type, &typelen);
8129 want_reply = ssh2_pkt_getbool(pktin);
8132 * We currently don't support any global requests
8133 * at all, so we either ignore the request or
8134 * respond with REQUEST_FAILURE, depending on
8138 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
8139 ssh2_pkt_send(ssh, pktout);
8143 struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype,
8147 struct X11FakeAuth *auth;
8150 * Make up a new set of fake X11 auth data, and add it to the tree
8151 * of currently valid ones with an indication of the sharing
8152 * context that it's relevant to.
8154 auth = x11_invent_fake_auth(ssh->x11authtree, authtype);
8155 auth->share_cs = share_cs;
8156 auth->share_chan = share_chan;
8161 void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth)
8163 del234(ssh->x11authtree, auth);
8164 x11_free_fake_auth(auth);
8167 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
8175 struct ssh_channel *c;
8176 unsigned remid, winsize, pktsize;
8177 unsigned our_winsize_override = 0;
8178 struct Packet *pktout;
8180 ssh_pkt_getstring(pktin, &type, &typelen);
8181 c = snew(struct ssh_channel);
8184 remid = ssh_pkt_getuint32(pktin);
8185 winsize = ssh_pkt_getuint32(pktin);
8186 pktsize = ssh_pkt_getuint32(pktin);
8188 if (typelen == 3 && !memcmp(type, "x11", 3)) {
8191 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8192 addrstr = snewn(peeraddrlen+1, char);
8193 memcpy(addrstr, peeraddr, peeraddrlen);
8194 addrstr[peeraddrlen] = '\0';
8195 peerport = ssh_pkt_getuint32(pktin);
8197 logeventf(ssh, "Received X11 connect request from %s:%d",
8200 if (!ssh->X11_fwd_enabled && !ssh->connshare)
8201 error = "X11 forwarding is not enabled";
8203 c->u.x11.xconn = x11_init(ssh->x11authtree, c,
8206 c->u.x11.initial = TRUE;
8209 * If we are a connection-sharing upstream, then we should
8210 * initially present a very small window, adequate to take
8211 * the X11 initial authorisation packet but not much more.
8212 * Downstream will then present us a larger window (by
8213 * fiat of the connection-sharing protocol) and we can
8214 * guarantee to send a positive-valued WINDOW_ADJUST.
8217 our_winsize_override = 128;
8219 logevent("Opened X11 forward channel");
8223 } else if (typelen == 15 &&
8224 !memcmp(type, "forwarded-tcpip", 15)) {
8225 struct ssh_rportfwd pf, *realpf;
8228 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
8229 pf.shost = dupprintf("%.*s", shostlen, shost);
8230 pf.sport = ssh_pkt_getuint32(pktin);
8231 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
8232 peerport = ssh_pkt_getuint32(pktin);
8233 realpf = find234(ssh->rportfwds, &pf, NULL);
8234 logeventf(ssh, "Received remote port %s:%d open request "
8235 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
8238 if (realpf == NULL) {
8239 error = "Remote port is not recognised";
8243 if (realpf->share_ctx) {
8245 * This port forwarding is on behalf of a
8246 * connection-sharing downstream, so abandon our own
8247 * channel-open procedure and just pass the message on
8250 share_got_pkt_from_server(realpf->share_ctx, pktin->type,
8251 pktin->body, pktin->length);
8256 err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport,
8257 c, ssh->conf, realpf->pfrec->addressfamily);
8258 logeventf(ssh, "Attempting to forward remote port to "
8259 "%s:%d", realpf->dhost, realpf->dport);
8261 logeventf(ssh, "Port open failed: %s", err);
8263 error = "Port open failed";
8265 logevent("Forwarded port opened successfully");
8266 c->type = CHAN_SOCKDATA;
8269 } else if (typelen == 22 &&
8270 !memcmp(type, "auth-agent@openssh.com", 22)) {
8271 if (!ssh->agentfwd_enabled)
8272 error = "Agent forwarding is not enabled";
8274 c->type = CHAN_AGENT; /* identify channel type */
8275 c->u.a.lensofar = 0;
8276 c->u.a.message = NULL;
8277 c->u.a.outstanding_requests = 0;
8280 error = "Unsupported channel type requested";
8283 c->remoteid = remid;
8284 c->halfopen = FALSE;
8286 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
8287 ssh2_pkt_adduint32(pktout, c->remoteid);
8288 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
8289 ssh2_pkt_addstring(pktout, error);
8290 ssh2_pkt_addstring(pktout, "en"); /* language tag */
8291 ssh2_pkt_send(ssh, pktout);
8292 logeventf(ssh, "Rejected channel open: %s", error);
8295 ssh2_channel_init(c);
8296 c->v.v2.remwindow = winsize;
8297 c->v.v2.remmaxpkt = pktsize;
8298 if (our_winsize_override) {
8299 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
8300 our_winsize_override;
8302 add234(ssh->channels, c);
8303 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
8304 ssh2_pkt_adduint32(pktout, c->remoteid);
8305 ssh2_pkt_adduint32(pktout, c->localid);
8306 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
8307 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8308 ssh2_pkt_send(ssh, pktout);
8312 void sshfwd_x11_sharing_handover(struct ssh_channel *c,
8313 void *share_cs, void *share_chan,
8314 const char *peer_addr, int peer_port,
8315 int endian, int protomajor, int protominor,
8316 const void *initial_data, int initial_len)
8319 * This function is called when we've just discovered that an X
8320 * forwarding channel on which we'd been handling the initial auth
8321 * ourselves turns out to be destined for a connection-sharing
8322 * downstream. So we turn the channel into a CHAN_SHARING, meaning
8323 * that we completely stop tracking windows and buffering data and
8324 * just pass more or less unmodified SSH messages back and forth.
8326 c->type = CHAN_SHARING;
8327 c->u.sharing.ctx = share_cs;
8328 share_setup_x11_channel(share_cs, share_chan,
8329 c->localid, c->remoteid, c->v.v2.remwindow,
8330 c->v.v2.remmaxpkt, c->v.v2.locwindow,
8331 peer_addr, peer_port, endian,
8332 protomajor, protominor,
8333 initial_data, initial_len);
8336 void sshfwd_x11_is_local(struct ssh_channel *c)
8339 * This function is called when we've just discovered that an X
8340 * forwarding channel is _not_ destined for a connection-sharing
8341 * downstream but we're going to handle it ourselves. We stop
8342 * presenting a cautiously small window and go into ordinary data
8345 c->u.x11.initial = FALSE;
8346 ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
8350 * Buffer banner messages for later display at some convenient point,
8351 * if we're going to display them.
8353 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
8355 /* Arbitrary limit to prevent unbounded inflation of buffer */
8356 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
8357 bufchain_size(&ssh->banner) <= 131072) {
8358 char *banner = NULL;
8360 ssh_pkt_getstring(pktin, &banner, &size);
8362 bufchain_add(&ssh->banner, banner, size);
8366 /* Helper function to deal with sending tty modes for "pty-req" */
8367 static void ssh2_send_ttymode(void *data, char *mode, char *val)
8369 struct Packet *pktout = (struct Packet *)data;
8371 unsigned int arg = 0;
8372 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
8373 if (i == lenof(ssh_ttymodes)) return;
8374 switch (ssh_ttymodes[i].type) {
8376 arg = ssh_tty_parse_specchar(val);
8379 arg = ssh_tty_parse_boolean(val);
8382 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
8383 ssh2_pkt_adduint32(pktout, arg);
8386 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
8389 struct ssh2_setup_x11_state {
8393 struct Packet *pktout;
8394 crStateP(ssh2_setup_x11_state, ctx);
8398 logevent("Requesting X11 forwarding");
8399 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
8401 ssh2_pkt_addbool(pktout, 0); /* many connections */
8402 ssh2_pkt_addstring(pktout, ssh->x11auth->protoname);
8403 ssh2_pkt_addstring(pktout, ssh->x11auth->datastring);
8404 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
8405 ssh2_pkt_send(ssh, pktout);
8407 /* Wait to be called back with either a response packet, or NULL
8408 * meaning clean up and free our data */
8412 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8413 logevent("X11 forwarding enabled");
8414 ssh->X11_fwd_enabled = TRUE;
8416 logevent("X11 forwarding refused");
8422 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
8425 struct ssh2_setup_agent_state {
8429 struct Packet *pktout;
8430 crStateP(ssh2_setup_agent_state, ctx);
8434 logevent("Requesting OpenSSH-style agent forwarding");
8435 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
8436 ssh2_setup_agent, s);
8437 ssh2_pkt_send(ssh, pktout);
8439 /* Wait to be called back with either a response packet, or NULL
8440 * meaning clean up and free our data */
8444 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8445 logevent("Agent forwarding enabled");
8446 ssh->agentfwd_enabled = TRUE;
8448 logevent("Agent forwarding refused");
8454 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
8457 struct ssh2_setup_pty_state {
8461 struct Packet *pktout;
8462 crStateP(ssh2_setup_pty_state, ctx);
8466 /* Unpick the terminal-speed string. */
8467 /* XXX perhaps we should allow no speeds to be sent. */
8468 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8469 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
8470 /* Build the pty request. */
8471 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
8473 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
8474 ssh2_pkt_adduint32(pktout, ssh->term_width);
8475 ssh2_pkt_adduint32(pktout, ssh->term_height);
8476 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
8477 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
8478 ssh2_pkt_addstring_start(pktout);
8479 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
8480 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
8481 ssh2_pkt_adduint32(pktout, ssh->ispeed);
8482 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
8483 ssh2_pkt_adduint32(pktout, ssh->ospeed);
8484 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
8485 ssh2_pkt_send(ssh, pktout);
8486 ssh->state = SSH_STATE_INTERMED;
8488 /* Wait to be called back with either a response packet, or NULL
8489 * meaning clean up and free our data */
8493 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
8494 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8495 ssh->ospeed, ssh->ispeed);
8496 ssh->got_pty = TRUE;
8498 c_write_str(ssh, "Server refused to allocate pty\r\n");
8499 ssh->editing = ssh->echoing = 1;
8506 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
8509 struct ssh2_setup_env_state {
8511 int num_env, env_left, env_ok;
8514 struct Packet *pktout;
8515 crStateP(ssh2_setup_env_state, ctx);
8520 * Send environment variables.
8522 * Simplest thing here is to send all the requests at once, and
8523 * then wait for a whole bunch of successes or failures.
8529 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
8531 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
8532 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
8533 ssh2_pkt_addstring(pktout, key);
8534 ssh2_pkt_addstring(pktout, val);
8535 ssh2_pkt_send(ssh, pktout);
8540 logeventf(ssh, "Sent %d environment variables", s->num_env);
8545 s->env_left = s->num_env;
8547 while (s->env_left > 0) {
8548 /* Wait to be called back with either a response packet,
8549 * or NULL meaning clean up and free our data */
8551 if (!pktin) goto out;
8552 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
8557 if (s->env_ok == s->num_env) {
8558 logevent("All environment variables successfully set");
8559 } else if (s->env_ok == 0) {
8560 logevent("All environment variables refused");
8561 c_write_str(ssh, "Server refused to set environment variables\r\n");
8563 logeventf(ssh, "%d environment variables refused",
8564 s->num_env - s->env_ok);
8565 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8573 * Handle the SSH-2 userauth and connection layers.
8575 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
8577 do_ssh2_authconn(ssh, NULL, 0, pktin);
8580 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
8584 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
8587 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
8588 struct Packet *pktin)
8590 struct do_ssh2_authconn_state {
8594 AUTH_TYPE_PUBLICKEY,
8595 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
8596 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
8598 AUTH_TYPE_GSSAPI, /* always QUIET */
8599 AUTH_TYPE_KEYBOARD_INTERACTIVE,
8600 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
8602 int done_service_req;
8603 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
8604 int tried_pubkey_config, done_agent;
8609 int kbd_inter_refused;
8610 int we_are_in, userauth_success;
8611 prompts_t *cur_prompt;
8616 void *publickey_blob;
8617 int publickey_bloblen;
8618 int publickey_encrypted;
8619 char *publickey_algorithm;
8620 char *publickey_comment;
8621 unsigned char agent_request[5], *agent_response, *agentp;
8622 int agent_responselen;
8623 unsigned char *pkblob_in_agent;
8625 char *pkblob, *alg, *commentp;
8626 int pklen, alglen, commentlen;
8627 int siglen, retlen, len;
8628 char *q, *agentreq, *ret;
8630 struct Packet *pktout;
8633 struct ssh_gss_library *gsslib;
8634 Ssh_gss_ctx gss_ctx;
8635 Ssh_gss_buf gss_buf;
8636 Ssh_gss_buf gss_rcvtok, gss_sndtok;
8637 Ssh_gss_name gss_srv_name;
8638 Ssh_gss_stat gss_stat;
8641 crState(do_ssh2_authconn_state);
8645 /* Register as a handler for all the messages this coroutine handles. */
8646 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
8647 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
8648 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
8649 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
8650 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
8651 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
8652 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
8653 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
8654 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
8655 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
8656 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
8657 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
8658 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
8659 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
8660 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
8661 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
8662 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
8663 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
8664 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
8665 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
8667 s->done_service_req = FALSE;
8668 s->we_are_in = s->userauth_success = FALSE;
8669 s->agent_response = NULL;
8671 s->tried_gssapi = FALSE;
8674 if (!ssh->bare_connection) {
8675 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
8677 * Request userauth protocol, and await a response to it.
8679 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8680 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
8681 ssh2_pkt_send(ssh, s->pktout);
8682 crWaitUntilV(pktin);
8683 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
8684 s->done_service_req = TRUE;
8686 if (!s->done_service_req) {
8688 * Request connection protocol directly, without authentication.
8690 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
8691 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8692 ssh2_pkt_send(ssh, s->pktout);
8693 crWaitUntilV(pktin);
8694 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
8695 s->we_are_in = TRUE; /* no auth required */
8697 bombout(("Server refused service request"));
8702 s->we_are_in = TRUE;
8705 /* Arrange to be able to deal with any BANNERs that come in.
8706 * (We do this now as packets may come in during the next bit.) */
8707 bufchain_init(&ssh->banner);
8708 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
8709 ssh2_msg_userauth_banner;
8712 * Misc one-time setup for authentication.
8714 s->publickey_blob = NULL;
8715 if (!s->we_are_in) {
8718 * Load the public half of any configured public key file
8721 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8722 if (!filename_is_null(s->keyfile)) {
8724 logeventf(ssh, "Reading private key file \"%.150s\"",
8725 filename_to_str(s->keyfile));
8726 keytype = key_type(s->keyfile);
8727 if (keytype == SSH_KEYTYPE_SSH2) {
8730 ssh2_userkey_loadpub(s->keyfile,
8731 &s->publickey_algorithm,
8732 &s->publickey_bloblen,
8733 &s->publickey_comment, &error);
8734 if (s->publickey_blob) {
8735 s->publickey_encrypted =
8736 ssh2_userkey_encrypted(s->keyfile, NULL);
8739 logeventf(ssh, "Unable to load private key (%s)",
8741 msgbuf = dupprintf("Unable to load private key file "
8742 "\"%.150s\" (%s)\r\n",
8743 filename_to_str(s->keyfile),
8745 c_write_str(ssh, msgbuf);
8750 logeventf(ssh, "Unable to use this key file (%s)",
8751 key_type_to_str(keytype));
8752 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8754 filename_to_str(s->keyfile),
8755 key_type_to_str(keytype));
8756 c_write_str(ssh, msgbuf);
8758 s->publickey_blob = NULL;
8763 * Find out about any keys Pageant has (but if there's a
8764 * public key configured, filter out all others).
8767 s->agent_response = NULL;
8768 s->pkblob_in_agent = NULL;
8769 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8773 logevent("Pageant is running. Requesting keys.");
8775 /* Request the keys held by the agent. */
8776 PUT_32BIT(s->agent_request, 1);
8777 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8778 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8779 ssh_agent_callback, ssh)) {
8783 bombout(("Unexpected data from server while"
8784 " waiting for agent response"));
8787 } while (pktin || inlen > 0);
8788 r = ssh->agent_response;
8789 s->agent_responselen = ssh->agent_response_len;
8791 s->agent_response = (unsigned char *) r;
8792 if (s->agent_response && s->agent_responselen >= 5 &&
8793 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8796 p = s->agent_response + 5;
8797 s->nkeys = toint(GET_32BIT(p));
8800 * Vet the Pageant response to ensure that the key
8801 * count and blob lengths make sense.
8804 logeventf(ssh, "Pageant response contained a negative"
8805 " key count %d", s->nkeys);
8807 goto done_agent_query;
8809 unsigned char *q = p + 4;
8810 int lenleft = s->agent_responselen - 5 - 4;
8812 for (keyi = 0; keyi < s->nkeys; keyi++) {
8813 int bloblen, commentlen;
8815 logeventf(ssh, "Pageant response was truncated");
8817 goto done_agent_query;
8819 bloblen = toint(GET_32BIT(q));
8820 if (bloblen < 0 || bloblen > lenleft) {
8821 logeventf(ssh, "Pageant response was truncated");
8823 goto done_agent_query;
8825 lenleft -= 4 + bloblen;
8827 commentlen = toint(GET_32BIT(q));
8828 if (commentlen < 0 || commentlen > lenleft) {
8829 logeventf(ssh, "Pageant response was truncated");
8831 goto done_agent_query;
8833 lenleft -= 4 + commentlen;
8834 q += 4 + commentlen;
8839 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8840 if (s->publickey_blob) {
8841 /* See if configured key is in agent. */
8842 for (keyi = 0; keyi < s->nkeys; keyi++) {
8843 s->pklen = toint(GET_32BIT(p));
8844 if (s->pklen == s->publickey_bloblen &&
8845 !memcmp(p+4, s->publickey_blob,
8846 s->publickey_bloblen)) {
8847 logeventf(ssh, "Pageant key #%d matches "
8848 "configured key file", keyi);
8850 s->pkblob_in_agent = p;
8854 p += toint(GET_32BIT(p)) + 4; /* comment */
8856 if (!s->pkblob_in_agent) {
8857 logevent("Configured key file not in Pageant");
8862 logevent("Failed to get reply from Pageant");
8870 * We repeat this whole loop, including the username prompt,
8871 * until we manage a successful authentication. If the user
8872 * types the wrong _password_, they can be sent back to the
8873 * beginning to try another username, if this is configured on.
8874 * (If they specify a username in the config, they are never
8875 * asked, even if they do give a wrong password.)
8877 * I think this best serves the needs of
8879 * - the people who have no configuration, no keys, and just
8880 * want to try repeated (username,password) pairs until they
8881 * type both correctly
8883 * - people who have keys and configuration but occasionally
8884 * need to fall back to passwords
8886 * - people with a key held in Pageant, who might not have
8887 * logged in to a particular machine before; so they want to
8888 * type a username, and then _either_ their key will be
8889 * accepted, _or_ they will type a password. If they mistype
8890 * the username they will want to be able to get back and
8893 s->got_username = FALSE;
8894 while (!s->we_are_in) {
8898 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8900 * We got a username last time round this loop, and
8901 * with change_username turned off we don't try to get
8904 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8905 int ret; /* need not be kept over crReturn */
8906 s->cur_prompt = new_prompts(ssh->frontend);
8907 s->cur_prompt->to_server = TRUE;
8908 s->cur_prompt->name = dupstr("SSH login name");
8909 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8910 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8913 crWaitUntilV(!pktin);
8914 ret = get_userpass_input(s->cur_prompt, in, inlen);
8919 * get_userpass_input() failed to get a username.
8922 free_prompts(s->cur_prompt);
8923 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8926 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8927 free_prompts(s->cur_prompt);
8930 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8931 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8932 c_write_str(ssh, stuff);
8936 s->got_username = TRUE;
8939 * Send an authentication request using method "none": (a)
8940 * just in case it succeeds, and (b) so that we know what
8941 * authentication methods we can usefully try next.
8943 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8945 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8946 ssh2_pkt_addstring(s->pktout, ssh->username);
8947 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8948 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8949 ssh2_pkt_send(ssh, s->pktout);
8950 s->type = AUTH_TYPE_NONE;
8952 s->we_are_in = FALSE;
8954 s->tried_pubkey_config = FALSE;
8955 s->kbd_inter_refused = FALSE;
8957 /* Reset agent request state. */
8958 s->done_agent = FALSE;
8959 if (s->agent_response) {
8960 if (s->pkblob_in_agent) {
8961 s->agentp = s->pkblob_in_agent;
8963 s->agentp = s->agent_response + 5 + 4;
8969 char *methods = NULL;
8973 * Wait for the result of the last authentication request.
8976 crWaitUntilV(pktin);
8978 * Now is a convenient point to spew any banner material
8979 * that we've accumulated. (This should ensure that when
8980 * we exit the auth loop, we haven't any left to deal
8984 int size = bufchain_size(&ssh->banner);
8986 * Don't show the banner if we're operating in
8987 * non-verbose non-interactive mode. (It's probably
8988 * a script, which means nobody will read the
8989 * banner _anyway_, and moreover the printing of
8990 * the banner will screw up processing on the
8991 * output of (say) plink.)
8993 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8994 char *banner = snewn(size, char);
8995 bufchain_fetch(&ssh->banner, banner, size);
8996 c_write_untrusted(ssh, banner, size);
8999 bufchain_clear(&ssh->banner);
9001 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
9002 logevent("Access granted");
9003 s->we_are_in = s->userauth_success = TRUE;
9007 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
9008 bombout(("Strange packet received during authentication: "
9009 "type %d", pktin->type));
9016 * OK, we're now sitting on a USERAUTH_FAILURE message, so
9017 * we can look at the string in it and know what we can
9018 * helpfully try next.
9020 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
9021 ssh_pkt_getstring(pktin, &methods, &methlen);
9022 if (!ssh2_pkt_getbool(pktin)) {
9024 * We have received an unequivocal Access
9025 * Denied. This can translate to a variety of
9026 * messages, or no message at all.
9028 * For forms of authentication which are attempted
9029 * implicitly, by which I mean without printing
9030 * anything in the window indicating that we're
9031 * trying them, we should never print 'Access
9034 * If we do print a message saying that we're
9035 * attempting some kind of authentication, it's OK
9036 * to print a followup message saying it failed -
9037 * but the message may sometimes be more specific
9038 * than simply 'Access denied'.
9040 * Additionally, if we'd just tried password
9041 * authentication, we should break out of this
9042 * whole loop so as to go back to the username
9043 * prompt (iff we're configured to allow
9044 * username change attempts).
9046 if (s->type == AUTH_TYPE_NONE) {
9048 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
9049 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
9050 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
9051 c_write_str(ssh, "Server refused our key\r\n");
9052 logevent("Server refused our key");
9053 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
9054 /* This _shouldn't_ happen except by a
9055 * protocol bug causing client and server to
9056 * disagree on what is a correct signature. */
9057 c_write_str(ssh, "Server refused public-key signature"
9058 " despite accepting key!\r\n");
9059 logevent("Server refused public-key signature"
9060 " despite accepting key!");
9061 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
9062 /* quiet, so no c_write */
9063 logevent("Server refused keyboard-interactive authentication");
9064 } else if (s->type==AUTH_TYPE_GSSAPI) {
9065 /* always quiet, so no c_write */
9066 /* also, the code down in the GSSAPI block has
9067 * already logged this in the Event Log */
9068 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
9069 logevent("Keyboard-interactive authentication failed");
9070 c_write_str(ssh, "Access denied\r\n");
9072 assert(s->type == AUTH_TYPE_PASSWORD);
9073 logevent("Password authentication failed");
9074 c_write_str(ssh, "Access denied\r\n");
9076 if (conf_get_int(ssh->conf, CONF_change_username)) {
9077 /* XXX perhaps we should allow
9078 * keyboard-interactive to do this too? */
9079 s->we_are_in = FALSE;
9084 c_write_str(ssh, "Further authentication required\r\n");
9085 logevent("Further authentication required");
9089 in_commasep_string("publickey", methods, methlen);
9091 in_commasep_string("password", methods, methlen);
9092 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
9093 in_commasep_string("keyboard-interactive", methods, methlen);
9096 ssh->gsslibs = ssh_gss_setup(ssh->conf);
9097 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
9098 in_commasep_string("gssapi-with-mic", methods, methlen) &&
9099 ssh->gsslibs->nlibraries > 0;
9103 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9105 if (s->can_pubkey && !s->done_agent && s->nkeys) {
9108 * Attempt public-key authentication using a key from Pageant.
9111 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9113 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
9115 /* Unpack key from agent response */
9116 s->pklen = toint(GET_32BIT(s->agentp));
9118 s->pkblob = (char *)s->agentp;
9119 s->agentp += s->pklen;
9120 s->alglen = toint(GET_32BIT(s->pkblob));
9121 s->alg = s->pkblob + 4;
9122 s->commentlen = toint(GET_32BIT(s->agentp));
9124 s->commentp = (char *)s->agentp;
9125 s->agentp += s->commentlen;
9126 /* s->agentp now points at next key, if any */
9128 /* See if server will accept it */
9129 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9130 ssh2_pkt_addstring(s->pktout, ssh->username);
9131 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9132 /* service requested */
9133 ssh2_pkt_addstring(s->pktout, "publickey");
9135 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
9136 ssh2_pkt_addstring_start(s->pktout);
9137 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9138 ssh2_pkt_addstring_start(s->pktout);
9139 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9140 ssh2_pkt_send(ssh, s->pktout);
9141 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
9143 crWaitUntilV(pktin);
9144 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9146 /* Offer of key refused. */
9153 if (flags & FLAG_VERBOSE) {
9154 c_write_str(ssh, "Authenticating with "
9156 c_write(ssh, s->commentp, s->commentlen);
9157 c_write_str(ssh, "\" from agent\r\n");
9161 * Server is willing to accept the key.
9162 * Construct a SIGN_REQUEST.
9164 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9165 ssh2_pkt_addstring(s->pktout, ssh->username);
9166 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9167 /* service requested */
9168 ssh2_pkt_addstring(s->pktout, "publickey");
9170 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
9171 ssh2_pkt_addstring_start(s->pktout);
9172 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
9173 ssh2_pkt_addstring_start(s->pktout);
9174 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
9176 /* Ask agent for signature. */
9177 s->siglen = s->pktout->length - 5 + 4 +
9178 ssh->v2_session_id_len;
9179 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9181 s->len = 1; /* message type */
9182 s->len += 4 + s->pklen; /* key blob */
9183 s->len += 4 + s->siglen; /* data to sign */
9184 s->len += 4; /* flags */
9185 s->agentreq = snewn(4 + s->len, char);
9186 PUT_32BIT(s->agentreq, s->len);
9187 s->q = s->agentreq + 4;
9188 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
9189 PUT_32BIT(s->q, s->pklen);
9191 memcpy(s->q, s->pkblob, s->pklen);
9193 PUT_32BIT(s->q, s->siglen);
9195 /* Now the data to be signed... */
9196 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9197 PUT_32BIT(s->q, ssh->v2_session_id_len);
9200 memcpy(s->q, ssh->v2_session_id,
9201 ssh->v2_session_id_len);
9202 s->q += ssh->v2_session_id_len;
9203 memcpy(s->q, s->pktout->data + 5,
9204 s->pktout->length - 5);
9205 s->q += s->pktout->length - 5;
9206 /* And finally the (zero) flags word. */
9208 if (!agent_query(s->agentreq, s->len + 4,
9210 ssh_agent_callback, ssh)) {
9214 bombout(("Unexpected data from server"
9215 " while waiting for agent"
9219 } while (pktin || inlen > 0);
9220 vret = ssh->agent_response;
9221 s->retlen = ssh->agent_response_len;
9226 if (s->retlen >= 9 &&
9227 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
9228 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
9229 logevent("Sending Pageant's response");
9230 ssh2_add_sigblob(ssh, s->pktout,
9231 s->pkblob, s->pklen,
9233 GET_32BIT(s->ret + 5));
9234 ssh2_pkt_send(ssh, s->pktout);
9235 s->type = AUTH_TYPE_PUBLICKEY;
9237 /* FIXME: less drastic response */
9238 bombout(("Pageant failed to answer challenge"));
9244 /* Do we have any keys left to try? */
9245 if (s->pkblob_in_agent) {
9246 s->done_agent = TRUE;
9247 s->tried_pubkey_config = TRUE;
9250 if (s->keyi >= s->nkeys)
9251 s->done_agent = TRUE;
9254 } else if (s->can_pubkey && s->publickey_blob &&
9255 !s->tried_pubkey_config) {
9257 struct ssh2_userkey *key; /* not live over crReturn */
9258 char *passphrase; /* not live over crReturn */
9260 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
9262 s->tried_pubkey_config = TRUE;
9265 * Try the public key supplied in the configuration.
9267 * First, offer the public blob to see if the server is
9268 * willing to accept it.
9270 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9271 ssh2_pkt_addstring(s->pktout, ssh->username);
9272 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9273 /* service requested */
9274 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
9275 ssh2_pkt_addbool(s->pktout, FALSE);
9276 /* no signature included */
9277 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
9278 ssh2_pkt_addstring_start(s->pktout);
9279 ssh2_pkt_addstring_data(s->pktout,
9280 (char *)s->publickey_blob,
9281 s->publickey_bloblen);
9282 ssh2_pkt_send(ssh, s->pktout);
9283 logevent("Offered public key");
9285 crWaitUntilV(pktin);
9286 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
9287 /* Key refused. Give up. */
9288 s->gotit = TRUE; /* reconsider message next loop */
9289 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
9290 continue; /* process this new message */
9292 logevent("Offer of public key accepted");
9295 * Actually attempt a serious authentication using
9298 if (flags & FLAG_VERBOSE) {
9299 c_write_str(ssh, "Authenticating with public key \"");
9300 c_write_str(ssh, s->publickey_comment);
9301 c_write_str(ssh, "\"\r\n");
9305 const char *error; /* not live over crReturn */
9306 if (s->publickey_encrypted) {
9308 * Get a passphrase from the user.
9310 int ret; /* need not be kept over crReturn */
9311 s->cur_prompt = new_prompts(ssh->frontend);
9312 s->cur_prompt->to_server = FALSE;
9313 s->cur_prompt->name = dupstr("SSH key passphrase");
9314 add_prompt(s->cur_prompt,
9315 dupprintf("Passphrase for key \"%.100s\": ",
9316 s->publickey_comment),
9318 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9321 crWaitUntilV(!pktin);
9322 ret = get_userpass_input(s->cur_prompt,
9327 /* Failed to get a passphrase. Terminate. */
9328 free_prompts(s->cur_prompt);
9329 ssh_disconnect(ssh, NULL,
9330 "Unable to authenticate",
9331 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9336 dupstr(s->cur_prompt->prompts[0]->result);
9337 free_prompts(s->cur_prompt);
9339 passphrase = NULL; /* no passphrase needed */
9343 * Try decrypting the key.
9345 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
9346 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
9348 /* burn the evidence */
9349 smemclr(passphrase, strlen(passphrase));
9352 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
9354 (key == SSH2_WRONG_PASSPHRASE)) {
9355 c_write_str(ssh, "Wrong passphrase\r\n");
9357 /* and loop again */
9359 c_write_str(ssh, "Unable to load private key (");
9360 c_write_str(ssh, error);
9361 c_write_str(ssh, ")\r\n");
9363 break; /* try something else */
9369 unsigned char *pkblob, *sigblob, *sigdata;
9370 int pkblob_len, sigblob_len, sigdata_len;
9374 * We have loaded the private key and the server
9375 * has announced that it's willing to accept it.
9376 * Hallelujah. Generate a signature and send it.
9378 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9379 ssh2_pkt_addstring(s->pktout, ssh->username);
9380 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9381 /* service requested */
9382 ssh2_pkt_addstring(s->pktout, "publickey");
9384 ssh2_pkt_addbool(s->pktout, TRUE);
9385 /* signature follows */
9386 ssh2_pkt_addstring(s->pktout, key->alg->name);
9387 pkblob = key->alg->public_blob(key->data,
9389 ssh2_pkt_addstring_start(s->pktout);
9390 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
9394 * The data to be signed is:
9398 * followed by everything so far placed in the
9401 sigdata_len = s->pktout->length - 5 + 4 +
9402 ssh->v2_session_id_len;
9403 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
9405 sigdata = snewn(sigdata_len, unsigned char);
9407 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
9408 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
9411 memcpy(sigdata+p, ssh->v2_session_id,
9412 ssh->v2_session_id_len);
9413 p += ssh->v2_session_id_len;
9414 memcpy(sigdata+p, s->pktout->data + 5,
9415 s->pktout->length - 5);
9416 p += s->pktout->length - 5;
9417 assert(p == sigdata_len);
9418 sigblob = key->alg->sign(key->data, (char *)sigdata,
9419 sigdata_len, &sigblob_len);
9420 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
9421 sigblob, sigblob_len);
9426 ssh2_pkt_send(ssh, s->pktout);
9427 logevent("Sent public key signature");
9428 s->type = AUTH_TYPE_PUBLICKEY;
9429 key->alg->freekey(key->data);
9433 } else if (s->can_gssapi && !s->tried_gssapi) {
9435 /* GSSAPI Authentication */
9440 s->type = AUTH_TYPE_GSSAPI;
9441 s->tried_gssapi = TRUE;
9443 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
9446 * Pick the highest GSS library on the preference
9452 for (i = 0; i < ngsslibs; i++) {
9453 int want_id = conf_get_int_int(ssh->conf,
9454 CONF_ssh_gsslist, i);
9455 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
9456 if (ssh->gsslibs->libraries[j].id == want_id) {
9457 s->gsslib = &ssh->gsslibs->libraries[j];
9458 goto got_gsslib; /* double break */
9463 * We always expect to have found something in
9464 * the above loop: we only came here if there
9465 * was at least one viable GSS library, and the
9466 * preference list should always mention
9467 * everything and only change the order.
9472 if (s->gsslib->gsslogmsg)
9473 logevent(s->gsslib->gsslogmsg);
9475 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
9476 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9477 ssh2_pkt_addstring(s->pktout, ssh->username);
9478 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9479 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
9480 logevent("Attempting GSSAPI authentication");
9482 /* add mechanism info */
9483 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
9485 /* number of GSSAPI mechanisms */
9486 ssh2_pkt_adduint32(s->pktout,1);
9488 /* length of OID + 2 */
9489 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
9490 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
9493 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
9495 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
9497 ssh2_pkt_send(ssh, s->pktout);
9498 crWaitUntilV(pktin);
9499 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
9500 logevent("GSSAPI authentication request refused");
9504 /* check returned packet ... */
9506 ssh_pkt_getstring(pktin, &data, &len);
9507 s->gss_rcvtok.value = data;
9508 s->gss_rcvtok.length = len;
9509 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
9510 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
9511 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
9512 memcmp((char *)s->gss_rcvtok.value + 2,
9513 s->gss_buf.value,s->gss_buf.length) ) {
9514 logevent("GSSAPI authentication - wrong response from server");
9518 /* now start running */
9519 s->gss_stat = s->gsslib->import_name(s->gsslib,
9522 if (s->gss_stat != SSH_GSS_OK) {
9523 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
9524 logevent("GSSAPI import name failed - Bad service name");
9526 logevent("GSSAPI import name failed");
9530 /* fetch TGT into GSS engine */
9531 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
9533 if (s->gss_stat != SSH_GSS_OK) {
9534 logevent("GSSAPI authentication failed to get credentials");
9535 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9539 /* initial tokens are empty */
9540 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
9541 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
9543 /* now enter the loop */
9545 s->gss_stat = s->gsslib->init_sec_context
9549 conf_get_int(ssh->conf, CONF_gssapifwd),
9553 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
9554 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
9555 logevent("GSSAPI authentication initialisation failed");
9557 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
9558 &s->gss_buf) == SSH_GSS_OK) {
9559 logevent(s->gss_buf.value);
9560 sfree(s->gss_buf.value);
9565 logevent("GSSAPI authentication initialised");
9567 /* Client and server now exchange tokens until GSSAPI
9568 * no longer says CONTINUE_NEEDED */
9570 if (s->gss_sndtok.length != 0) {
9571 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
9572 ssh_pkt_addstring_start(s->pktout);
9573 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
9574 ssh2_pkt_send(ssh, s->pktout);
9575 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
9578 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
9579 crWaitUntilV(pktin);
9580 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
9581 logevent("GSSAPI authentication - bad server response");
9582 s->gss_stat = SSH_GSS_FAILURE;
9585 ssh_pkt_getstring(pktin, &data, &len);
9586 s->gss_rcvtok.value = data;
9587 s->gss_rcvtok.length = len;
9589 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
9591 if (s->gss_stat != SSH_GSS_OK) {
9592 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9593 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9596 logevent("GSSAPI authentication loop finished OK");
9598 /* Now send the MIC */
9600 s->pktout = ssh2_pkt_init(0);
9601 micoffset = s->pktout->length;
9602 ssh_pkt_addstring_start(s->pktout);
9603 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
9604 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
9605 ssh_pkt_addstring(s->pktout, ssh->username);
9606 ssh_pkt_addstring(s->pktout, "ssh-connection");
9607 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
9609 s->gss_buf.value = (char *)s->pktout->data + micoffset;
9610 s->gss_buf.length = s->pktout->length - micoffset;
9612 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
9613 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
9614 ssh_pkt_addstring_start(s->pktout);
9615 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
9616 ssh2_pkt_send(ssh, s->pktout);
9617 s->gsslib->free_mic(s->gsslib, &mic);
9621 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
9622 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
9625 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
9628 * Keyboard-interactive authentication.
9631 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
9633 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
9635 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9636 ssh2_pkt_addstring(s->pktout, ssh->username);
9637 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9638 /* service requested */
9639 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
9641 ssh2_pkt_addstring(s->pktout, ""); /* lang */
9642 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
9643 ssh2_pkt_send(ssh, s->pktout);
9645 logevent("Attempting keyboard-interactive authentication");
9647 crWaitUntilV(pktin);
9648 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
9649 /* Server is not willing to do keyboard-interactive
9650 * at all (or, bizarrely but legally, accepts the
9651 * user without actually issuing any prompts).
9652 * Give up on it entirely. */
9654 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
9655 s->kbd_inter_refused = TRUE; /* don't try it again */
9660 * Loop while the server continues to send INFO_REQUESTs.
9662 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
9664 char *name, *inst, *lang;
9665 int name_len, inst_len, lang_len;
9669 * We've got a fresh USERAUTH_INFO_REQUEST.
9670 * Get the preamble and start building a prompt.
9672 ssh_pkt_getstring(pktin, &name, &name_len);
9673 ssh_pkt_getstring(pktin, &inst, &inst_len);
9674 ssh_pkt_getstring(pktin, &lang, &lang_len);
9675 s->cur_prompt = new_prompts(ssh->frontend);
9676 s->cur_prompt->to_server = TRUE;
9679 * Get any prompt(s) from the packet.
9681 s->num_prompts = ssh_pkt_getuint32(pktin);
9682 for (i = 0; i < s->num_prompts; i++) {
9686 static char noprompt[] =
9687 "<server failed to send prompt>: ";
9689 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9690 echo = ssh2_pkt_getbool(pktin);
9693 prompt_len = lenof(noprompt)-1;
9695 add_prompt(s->cur_prompt,
9696 dupprintf("%.*s", prompt_len, prompt),
9701 /* FIXME: better prefix to distinguish from
9703 s->cur_prompt->name =
9704 dupprintf("SSH server: %.*s", name_len, name);
9705 s->cur_prompt->name_reqd = TRUE;
9707 s->cur_prompt->name =
9708 dupstr("SSH server authentication");
9709 s->cur_prompt->name_reqd = FALSE;
9711 /* We add a prefix to try to make it clear that a prompt
9712 * has come from the server.
9713 * FIXME: ugly to print "Using..." in prompt _every_
9714 * time round. Can this be done more subtly? */
9715 /* Special case: for reasons best known to themselves,
9716 * some servers send k-i requests with no prompts and
9717 * nothing to display. Keep quiet in this case. */
9718 if (s->num_prompts || name_len || inst_len) {
9719 s->cur_prompt->instruction =
9720 dupprintf("Using keyboard-interactive authentication.%s%.*s",
9721 inst_len ? "\n" : "", inst_len, inst);
9722 s->cur_prompt->instr_reqd = TRUE;
9724 s->cur_prompt->instr_reqd = FALSE;
9728 * Display any instructions, and get the user's
9732 int ret; /* not live over crReturn */
9733 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9736 crWaitUntilV(!pktin);
9737 ret = get_userpass_input(s->cur_prompt, in, inlen);
9742 * Failed to get responses. Terminate.
9744 free_prompts(s->cur_prompt);
9745 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9746 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9753 * Send the response(s) to the server.
9755 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9756 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9757 for (i=0; i < s->num_prompts; i++) {
9758 ssh2_pkt_addstring(s->pktout,
9759 s->cur_prompt->prompts[i]->result);
9761 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9764 * Free the prompts structure from this iteration.
9765 * If there's another, a new one will be allocated
9766 * when we return to the top of this while loop.
9768 free_prompts(s->cur_prompt);
9771 * Get the next packet in case it's another
9774 crWaitUntilV(pktin);
9779 * We should have SUCCESS or FAILURE now.
9783 } else if (s->can_passwd) {
9786 * Plain old password authentication.
9788 int ret; /* not live over crReturn */
9789 int changereq_first_time; /* not live over crReturn */
9791 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9793 s->cur_prompt = new_prompts(ssh->frontend);
9794 s->cur_prompt->to_server = TRUE;
9795 s->cur_prompt->name = dupstr("SSH password");
9796 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9801 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9804 crWaitUntilV(!pktin);
9805 ret = get_userpass_input(s->cur_prompt, in, inlen);
9810 * Failed to get responses. Terminate.
9812 free_prompts(s->cur_prompt);
9813 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9814 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9819 * Squirrel away the password. (We may need it later if
9820 * asked to change it.)
9822 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9823 free_prompts(s->cur_prompt);
9826 * Send the password packet.
9828 * We pad out the password packet to 256 bytes to make
9829 * it harder for an attacker to find the length of the
9832 * Anyone using a password longer than 256 bytes
9833 * probably doesn't have much to worry about from
9834 * people who find out how long their password is!
9836 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9837 ssh2_pkt_addstring(s->pktout, ssh->username);
9838 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9839 /* service requested */
9840 ssh2_pkt_addstring(s->pktout, "password");
9841 ssh2_pkt_addbool(s->pktout, FALSE);
9842 ssh2_pkt_addstring(s->pktout, s->password);
9843 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9844 logevent("Sent password");
9845 s->type = AUTH_TYPE_PASSWORD;
9848 * Wait for next packet, in case it's a password change
9851 crWaitUntilV(pktin);
9852 changereq_first_time = TRUE;
9854 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9857 * We're being asked for a new password
9858 * (perhaps not for the first time).
9859 * Loop until the server accepts it.
9862 int got_new = FALSE; /* not live over crReturn */
9863 char *prompt; /* not live over crReturn */
9864 int prompt_len; /* not live over crReturn */
9868 if (changereq_first_time)
9869 msg = "Server requested password change";
9871 msg = "Server rejected new password";
9873 c_write_str(ssh, msg);
9874 c_write_str(ssh, "\r\n");
9877 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9879 s->cur_prompt = new_prompts(ssh->frontend);
9880 s->cur_prompt->to_server = TRUE;
9881 s->cur_prompt->name = dupstr("New SSH password");
9882 s->cur_prompt->instruction =
9883 dupprintf("%.*s", prompt_len, prompt);
9884 s->cur_prompt->instr_reqd = TRUE;
9886 * There's no explicit requirement in the protocol
9887 * for the "old" passwords in the original and
9888 * password-change messages to be the same, and
9889 * apparently some Cisco kit supports password change
9890 * by the user entering a blank password originally
9891 * and the real password subsequently, so,
9892 * reluctantly, we prompt for the old password again.
9894 * (On the other hand, some servers don't even bother
9895 * to check this field.)
9897 add_prompt(s->cur_prompt,
9898 dupstr("Current password (blank for previously entered password): "),
9900 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9902 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9906 * Loop until the user manages to enter the same
9911 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9914 crWaitUntilV(!pktin);
9915 ret = get_userpass_input(s->cur_prompt, in, inlen);
9920 * Failed to get responses. Terminate.
9922 /* burn the evidence */
9923 free_prompts(s->cur_prompt);
9924 smemclr(s->password, strlen(s->password));
9926 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9927 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9933 * If the user specified a new original password
9934 * (IYSWIM), overwrite any previously specified
9936 * (A side effect is that the user doesn't have to
9937 * re-enter it if they louse up the new password.)
9939 if (s->cur_prompt->prompts[0]->result[0]) {
9940 smemclr(s->password, strlen(s->password));
9941 /* burn the evidence */
9944 dupstr(s->cur_prompt->prompts[0]->result);
9948 * Check the two new passwords match.
9950 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9951 s->cur_prompt->prompts[2]->result)
9954 /* They don't. Silly user. */
9955 c_write_str(ssh, "Passwords do not match\r\n");
9960 * Send the new password (along with the old one).
9961 * (see above for padding rationale)
9963 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9964 ssh2_pkt_addstring(s->pktout, ssh->username);
9965 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9966 /* service requested */
9967 ssh2_pkt_addstring(s->pktout, "password");
9968 ssh2_pkt_addbool(s->pktout, TRUE);
9969 ssh2_pkt_addstring(s->pktout, s->password);
9970 ssh2_pkt_addstring(s->pktout,
9971 s->cur_prompt->prompts[1]->result);
9972 free_prompts(s->cur_prompt);
9973 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9974 logevent("Sent new password");
9977 * Now see what the server has to say about it.
9978 * (If it's CHANGEREQ again, it's not happy with the
9981 crWaitUntilV(pktin);
9982 changereq_first_time = FALSE;
9987 * We need to reexamine the current pktin at the top
9988 * of the loop. Either:
9989 * - we weren't asked to change password at all, in
9990 * which case it's a SUCCESS or FAILURE with the
9992 * - we sent a new password, and the server was
9993 * either OK with it (SUCCESS or FAILURE w/partial
9994 * success) or unhappy with the _old_ password
9995 * (FAILURE w/o partial success)
9996 * In any of these cases, we go back to the top of
9997 * the loop and start again.
10002 * We don't need the old password any more, in any
10003 * case. Burn the evidence.
10005 smemclr(s->password, strlen(s->password));
10006 sfree(s->password);
10009 char *str = dupprintf("No supported authentication methods available"
10010 " (server sent: %.*s)",
10013 ssh_disconnect(ssh, str,
10014 "No supported authentication methods available",
10015 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
10025 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
10027 /* Clear up various bits and pieces from authentication. */
10028 if (s->publickey_blob) {
10029 sfree(s->publickey_blob);
10030 sfree(s->publickey_comment);
10032 if (s->agent_response)
10033 sfree(s->agent_response);
10035 if (s->userauth_success && !ssh->bare_connection) {
10037 * We've just received USERAUTH_SUCCESS, and we haven't sent any
10038 * packets since. Signal the transport layer to consider enacting
10039 * delayed compression.
10041 * (Relying on we_are_in is not sufficient, as
10042 * draft-miller-secsh-compression-delayed is quite clear that it
10043 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
10044 * become set for other reasons.)
10046 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
10049 ssh->channels = newtree234(ssh_channelcmp);
10052 * Set up handlers for some connection protocol messages, so we
10053 * don't have to handle them repeatedly in this coroutine.
10055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
10056 ssh2_msg_channel_window_adjust;
10057 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
10058 ssh2_msg_global_request;
10061 * Create the main session channel.
10063 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
10064 ssh->mainchan = NULL;
10066 ssh->mainchan = snew(struct ssh_channel);
10067 ssh->mainchan->ssh = ssh;
10068 ssh2_channel_init(ssh->mainchan);
10070 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
10072 * Just start a direct-tcpip channel and use it as the main
10075 ssh_send_port_open(ssh->mainchan,
10076 conf_get_str(ssh->conf, CONF_ssh_nc_host),
10077 conf_get_int(ssh->conf, CONF_ssh_nc_port),
10079 ssh->ncmode = TRUE;
10081 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
10082 logevent("Opening session as main channel");
10083 ssh2_pkt_send(ssh, s->pktout);
10084 ssh->ncmode = FALSE;
10086 crWaitUntilV(pktin);
10087 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
10088 bombout(("Server refused to open channel"));
10090 /* FIXME: error data comes back in FAILURE packet */
10092 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
10093 bombout(("Server's channel confirmation cited wrong channel"));
10096 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
10097 ssh->mainchan->halfopen = FALSE;
10098 ssh->mainchan->type = CHAN_MAINSESSION;
10099 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
10100 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
10101 add234(ssh->channels, ssh->mainchan);
10102 update_specials_menu(ssh->frontend);
10103 logevent("Opened main channel");
10107 * Now we have a channel, make dispatch table entries for
10108 * general channel-based messages.
10110 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
10111 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
10112 ssh2_msg_channel_data;
10113 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
10114 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
10115 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
10116 ssh2_msg_channel_open_confirmation;
10117 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
10118 ssh2_msg_channel_open_failure;
10119 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
10120 ssh2_msg_channel_request;
10121 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
10122 ssh2_msg_channel_open;
10123 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
10124 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
10127 * Now the connection protocol is properly up and running, with
10128 * all those dispatch table entries, so it's safe to let
10129 * downstreams start trying to open extra channels through us.
10131 if (ssh->connshare)
10132 share_activate(ssh->connshare, ssh->v_s);
10134 if (ssh->mainchan && ssh_is_simple(ssh)) {
10136 * This message indicates to the server that we promise
10137 * not to try to run any other channel in parallel with
10138 * this one, so it's safe for it to advertise a very large
10139 * window and leave the flow control to TCP.
10141 s->pktout = ssh2_chanreq_init(ssh->mainchan,
10142 "simple@putty.projects.tartarus.org",
10144 ssh2_pkt_send(ssh, s->pktout);
10148 * Enable port forwardings.
10150 ssh_setup_portfwd(ssh, ssh->conf);
10152 if (ssh->mainchan && !ssh->ncmode) {
10154 * Send the CHANNEL_REQUESTS for the main session channel.
10155 * Each one is handled by its own little asynchronous
10159 /* Potentially enable X11 forwarding. */
10160 if (conf_get_int(ssh->conf, CONF_x11_forward)) {
10162 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
10164 if (!ssh->x11disp) {
10165 /* FIXME: return an error message from x11_setup_display */
10166 logevent("X11 forwarding not enabled: unable to"
10167 " initialise X display");
10169 ssh->x11auth = x11_invent_fake_auth
10170 (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth));
10171 ssh->x11auth->disp = ssh->x11disp;
10173 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
10177 /* Potentially enable agent forwarding. */
10178 if (ssh_agent_forwarding_permitted(ssh))
10179 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
10181 /* Now allocate a pty for the session. */
10182 if (!conf_get_int(ssh->conf, CONF_nopty))
10183 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
10185 /* Send environment variables. */
10186 ssh2_setup_env(ssh->mainchan, NULL, NULL);
10189 * Start a shell or a remote command. We may have to attempt
10190 * this twice if the config data has provided a second choice
10197 if (ssh->fallback_cmd) {
10198 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
10199 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
10201 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
10202 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
10206 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
10207 ssh2_response_authconn, NULL);
10208 ssh2_pkt_addstring(s->pktout, cmd);
10210 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
10211 ssh2_response_authconn, NULL);
10212 ssh2_pkt_addstring(s->pktout, cmd);
10214 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
10215 ssh2_response_authconn, NULL);
10217 ssh2_pkt_send(ssh, s->pktout);
10219 crWaitUntilV(pktin);
10221 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
10222 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
10223 bombout(("Unexpected response to shell/command request:"
10224 " packet type %d", pktin->type));
10228 * We failed to start the command. If this is the
10229 * fallback command, we really are finished; if it's
10230 * not, and if the fallback command exists, try falling
10231 * back to it before complaining.
10233 if (!ssh->fallback_cmd &&
10234 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
10235 logevent("Primary command failed; attempting fallback");
10236 ssh->fallback_cmd = TRUE;
10239 bombout(("Server refused to start a shell/command"));
10242 logevent("Started a shell/command");
10247 ssh->editing = ssh->echoing = TRUE;
10250 ssh->state = SSH_STATE_SESSION;
10251 if (ssh->size_needed)
10252 ssh_size(ssh, ssh->term_width, ssh->term_height);
10253 if (ssh->eof_needed)
10254 ssh_special(ssh, TS_EOF);
10260 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
10265 s->try_send = FALSE;
10269 * _All_ the connection-layer packets we expect to
10270 * receive are now handled by the dispatch table.
10271 * Anything that reaches here must be bogus.
10274 bombout(("Strange packet received: type %d", pktin->type));
10276 } else if (ssh->mainchan) {
10278 * We have spare data. Add it to the channel buffer.
10280 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
10281 s->try_send = TRUE;
10285 struct ssh_channel *c;
10287 * Try to send data on all channels if we can.
10289 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
10290 ssh2_try_send_and_unthrottle(ssh, c);
10298 * Handlers for SSH-2 messages that might arrive at any moment.
10300 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
10302 /* log reason code in disconnect message */
10304 int reason, msglen;
10306 reason = ssh_pkt_getuint32(pktin);
10307 ssh_pkt_getstring(pktin, &msg, &msglen);
10309 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
10310 buf = dupprintf("Received disconnect message (%s)",
10311 ssh2_disconnect_reasons[reason]);
10313 buf = dupprintf("Received disconnect message (unknown"
10314 " type %d)", reason);
10318 buf = dupprintf("Disconnection message text: %.*s",
10321 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
10323 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
10324 ssh2_disconnect_reasons[reason] : "unknown",
10329 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
10331 /* log the debug message */
10335 /* XXX maybe we should actually take notice of the return value */
10336 ssh2_pkt_getbool(pktin);
10337 ssh_pkt_getstring(pktin, &msg, &msglen);
10339 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
10342 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
10344 do_ssh2_transport(ssh, NULL, 0, pktin);
10348 * Called if we receive a packet that isn't allowed by the protocol.
10349 * This only applies to packets whose meaning PuTTY understands.
10350 * Entirely unknown packets are handled below.
10352 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
10354 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
10355 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
10357 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
10361 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
10363 struct Packet *pktout;
10364 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
10365 ssh2_pkt_adduint32(pktout, pktin->sequence);
10367 * UNIMPLEMENTED messages MUST appear in the same order as the
10368 * messages they respond to. Hence, never queue them.
10370 ssh2_pkt_send_noqueue(ssh, pktout);
10374 * Handle the top-level SSH-2 protocol.
10376 static void ssh2_protocol_setup(Ssh ssh)
10381 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10383 for (i = 0; i < 256; i++)
10384 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10387 * Initially, we only accept transport messages (and a few generic
10388 * ones). do_ssh2_authconn will add more when it starts.
10389 * Messages that are understood but not currently acceptable go to
10390 * ssh2_msg_unexpected.
10392 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10393 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
10394 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
10395 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
10396 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
10397 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
10398 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
10399 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
10400 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
10401 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
10402 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
10403 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
10404 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
10405 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
10406 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
10407 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
10408 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
10409 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
10410 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
10411 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10412 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10413 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10414 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10415 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10416 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10417 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10418 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10419 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10420 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10421 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10422 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10423 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10424 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10427 * These messages have a special handler from the start.
10429 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10430 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
10431 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10434 static void ssh2_bare_connection_protocol_setup(Ssh ssh)
10439 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
10441 for (i = 0; i < 256; i++)
10442 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
10445 * Initially, we set all ssh-connection messages to 'unexpected';
10446 * do_ssh2_authconn will fill things in properly. We also handle a
10447 * couple of messages from the transport protocol which aren't
10448 * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG,
10451 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
10452 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
10453 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
10454 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
10455 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
10456 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
10457 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
10458 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
10459 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
10460 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
10461 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
10462 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
10463 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
10464 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
10466 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
10469 * These messages have a special handler from the start.
10471 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
10472 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore;
10473 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
10476 static void ssh2_timer(void *ctx, unsigned long now)
10478 Ssh ssh = (Ssh)ctx;
10480 if (ssh->state == SSH_STATE_CLOSED)
10483 if (!ssh->kex_in_progress && !ssh->bare_connection &&
10484 conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
10485 now == ssh->next_rekey) {
10486 do_ssh2_transport(ssh, "timeout", -1, NULL);
10490 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
10491 struct Packet *pktin)
10493 unsigned char *in = (unsigned char *)vin;
10494 if (ssh->state == SSH_STATE_CLOSED)
10498 ssh->incoming_data_size += pktin->encrypted_len;
10499 if (!ssh->kex_in_progress &&
10500 ssh->max_data_size != 0 &&
10501 ssh->incoming_data_size > ssh->max_data_size)
10502 do_ssh2_transport(ssh, "too much data received", -1, NULL);
10506 ssh->packet_dispatch[pktin->type](ssh, pktin);
10507 else if (!ssh->protocol_initial_phase_done)
10508 do_ssh2_transport(ssh, in, inlen, pktin);
10510 do_ssh2_authconn(ssh, in, inlen, pktin);
10513 static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen,
10514 struct Packet *pktin)
10516 unsigned char *in = (unsigned char *)vin;
10517 if (ssh->state == SSH_STATE_CLOSED)
10521 ssh->packet_dispatch[pktin->type](ssh, pktin);
10523 do_ssh2_authconn(ssh, in, inlen, pktin);
10526 static void ssh_cache_conf_values(Ssh ssh)
10528 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
10532 * Called to set up the connection.
10534 * Returns an error message, or NULL on success.
10536 static const char *ssh_init(void *frontend_handle, void **backend_handle,
10537 Conf *conf, char *host, int port, char **realhost,
10538 int nodelay, int keepalive)
10543 ssh = snew(struct ssh_tag);
10544 ssh->conf = conf_copy(conf);
10545 ssh_cache_conf_values(ssh);
10546 ssh->version = 0; /* when not ready yet */
10548 ssh->cipher = NULL;
10549 ssh->v1_cipher_ctx = NULL;
10550 ssh->crcda_ctx = NULL;
10551 ssh->cscipher = NULL;
10552 ssh->cs_cipher_ctx = NULL;
10553 ssh->sccipher = NULL;
10554 ssh->sc_cipher_ctx = NULL;
10556 ssh->cs_mac_ctx = NULL;
10558 ssh->sc_mac_ctx = NULL;
10559 ssh->cscomp = NULL;
10560 ssh->cs_comp_ctx = NULL;
10561 ssh->sccomp = NULL;
10562 ssh->sc_comp_ctx = NULL;
10564 ssh->kex_ctx = NULL;
10565 ssh->hostkey = NULL;
10566 ssh->hostkey_str = NULL;
10567 ssh->exitcode = -1;
10568 ssh->close_expected = FALSE;
10569 ssh->clean_exit = FALSE;
10570 ssh->state = SSH_STATE_PREPACKET;
10571 ssh->size_needed = FALSE;
10572 ssh->eof_needed = FALSE;
10574 ssh->logctx = NULL;
10575 ssh->deferred_send_data = NULL;
10576 ssh->deferred_len = 0;
10577 ssh->deferred_size = 0;
10578 ssh->fallback_cmd = 0;
10579 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
10580 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
10581 ssh->x11disp = NULL;
10582 ssh->x11auth = NULL;
10583 ssh->x11authtree = newtree234(x11_authcmp);
10584 ssh->v1_compressing = FALSE;
10585 ssh->v2_outgoing_sequence = 0;
10586 ssh->ssh1_rdpkt_crstate = 0;
10587 ssh->ssh2_rdpkt_crstate = 0;
10588 ssh->ssh2_bare_rdpkt_crstate = 0;
10589 ssh->ssh_gotdata_crstate = 0;
10590 ssh->do_ssh1_connection_crstate = 0;
10591 ssh->do_ssh_init_state = NULL;
10592 ssh->do_ssh_connection_init_state = NULL;
10593 ssh->do_ssh1_login_state = NULL;
10594 ssh->do_ssh2_transport_state = NULL;
10595 ssh->do_ssh2_authconn_state = NULL;
10598 ssh->mainchan = NULL;
10599 ssh->throttled_all = 0;
10600 ssh->v1_stdout_throttling = 0;
10602 ssh->queuelen = ssh->queuesize = 0;
10603 ssh->queueing = FALSE;
10604 ssh->qhead = ssh->qtail = NULL;
10605 ssh->deferred_rekey_reason = NULL;
10606 bufchain_init(&ssh->queued_incoming_data);
10607 ssh->frozen = FALSE;
10608 ssh->username = NULL;
10609 ssh->sent_console_eof = FALSE;
10610 ssh->got_pty = FALSE;
10611 ssh->bare_connection = FALSE;
10612 ssh->X11_fwd_enabled = FALSE;
10613 ssh->connshare = NULL;
10614 ssh->attempting_connshare = FALSE;
10616 *backend_handle = ssh;
10619 if (crypto_startup() == 0)
10620 return "Microsoft high encryption pack not installed!";
10623 ssh->frontend = frontend_handle;
10624 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
10625 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
10627 ssh->channels = NULL;
10628 ssh->rportfwds = NULL;
10629 ssh->portfwds = NULL;
10634 ssh->conn_throttle_count = 0;
10635 ssh->overall_bufsize = 0;
10636 ssh->fallback_cmd = 0;
10638 ssh->protocol = NULL;
10640 ssh->protocol_initial_phase_done = FALSE;
10642 ssh->pinger = NULL;
10644 ssh->incoming_data_size = ssh->outgoing_data_size =
10645 ssh->deferred_data_size = 0L;
10646 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10647 CONF_ssh_rekey_data));
10648 ssh->kex_in_progress = FALSE;
10651 ssh->gsslibs = NULL;
10654 random_ref(); /* do this now - may be needed by sharing setup code */
10656 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
10665 static void ssh_free(void *handle)
10667 Ssh ssh = (Ssh) handle;
10668 struct ssh_channel *c;
10669 struct ssh_rportfwd *pf;
10670 struct X11FakeAuth *auth;
10672 if (ssh->v1_cipher_ctx)
10673 ssh->cipher->free_context(ssh->v1_cipher_ctx);
10674 if (ssh->cs_cipher_ctx)
10675 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
10676 if (ssh->sc_cipher_ctx)
10677 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
10678 if (ssh->cs_mac_ctx)
10679 ssh->csmac->free_context(ssh->cs_mac_ctx);
10680 if (ssh->sc_mac_ctx)
10681 ssh->scmac->free_context(ssh->sc_mac_ctx);
10682 if (ssh->cs_comp_ctx) {
10684 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
10686 zlib_compress_cleanup(ssh->cs_comp_ctx);
10688 if (ssh->sc_comp_ctx) {
10690 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
10692 zlib_decompress_cleanup(ssh->sc_comp_ctx);
10695 dh_cleanup(ssh->kex_ctx);
10696 sfree(ssh->savedhost);
10698 while (ssh->queuelen-- > 0)
10699 ssh_free_packet(ssh->queue[ssh->queuelen]);
10702 while (ssh->qhead) {
10703 struct queued_handler *qh = ssh->qhead;
10704 ssh->qhead = qh->next;
10707 ssh->qhead = ssh->qtail = NULL;
10709 if (ssh->channels) {
10710 while ((c = delpos234(ssh->channels, 0)) != NULL) {
10713 if (c->u.x11.xconn != NULL)
10714 x11_close(c->u.x11.xconn);
10716 case CHAN_SOCKDATA:
10717 case CHAN_SOCKDATA_DORMANT:
10718 if (c->u.pfd.pf != NULL)
10719 pfd_close(c->u.pfd.pf);
10722 if (ssh->version == 2) {
10723 struct outstanding_channel_request *ocr, *nocr;
10724 ocr = c->v.v2.chanreq_head;
10726 ocr->handler(c, NULL, ocr->ctx);
10731 bufchain_clear(&c->v.v2.outbuffer);
10735 freetree234(ssh->channels);
10736 ssh->channels = NULL;
10739 if (ssh->connshare)
10740 sharestate_free(ssh->connshare);
10742 if (ssh->rportfwds) {
10743 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
10745 freetree234(ssh->rportfwds);
10746 ssh->rportfwds = NULL;
10748 sfree(ssh->deferred_send_data);
10750 x11_free_display(ssh->x11disp);
10751 while ((auth = delpos234(ssh->x11authtree, 0)) != NULL)
10752 x11_free_fake_auth(auth);
10753 freetree234(ssh->x11authtree);
10754 sfree(ssh->do_ssh_init_state);
10755 sfree(ssh->do_ssh1_login_state);
10756 sfree(ssh->do_ssh2_transport_state);
10757 sfree(ssh->do_ssh2_authconn_state);
10760 sfree(ssh->fullhostname);
10761 sfree(ssh->hostkey_str);
10762 if (ssh->crcda_ctx) {
10763 crcda_free_context(ssh->crcda_ctx);
10764 ssh->crcda_ctx = NULL;
10767 ssh_do_close(ssh, TRUE);
10768 expire_timer_context(ssh);
10770 pinger_free(ssh->pinger);
10771 bufchain_clear(&ssh->queued_incoming_data);
10772 sfree(ssh->username);
10773 conf_free(ssh->conf);
10776 ssh_gss_cleanup(ssh->gsslibs);
10784 * Reconfigure the SSH backend.
10786 static void ssh_reconfig(void *handle, Conf *conf)
10788 Ssh ssh = (Ssh) handle;
10789 char *rekeying = NULL, rekey_mandatory = FALSE;
10790 unsigned long old_max_data_size;
10793 pinger_reconfig(ssh->pinger, ssh->conf, conf);
10795 ssh_setup_portfwd(ssh, conf);
10797 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
10798 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
10800 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
10801 unsigned long now = GETTICKCOUNT();
10803 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
10804 rekeying = "timeout shortened";
10806 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
10810 old_max_data_size = ssh->max_data_size;
10811 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
10812 CONF_ssh_rekey_data));
10813 if (old_max_data_size != ssh->max_data_size &&
10814 ssh->max_data_size != 0) {
10815 if (ssh->outgoing_data_size > ssh->max_data_size ||
10816 ssh->incoming_data_size > ssh->max_data_size)
10817 rekeying = "data limit lowered";
10820 if (conf_get_int(ssh->conf, CONF_compression) !=
10821 conf_get_int(conf, CONF_compression)) {
10822 rekeying = "compression setting changed";
10823 rekey_mandatory = TRUE;
10826 for (i = 0; i < CIPHER_MAX; i++)
10827 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
10828 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
10829 rekeying = "cipher settings changed";
10830 rekey_mandatory = TRUE;
10832 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
10833 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10834 rekeying = "cipher settings changed";
10835 rekey_mandatory = TRUE;
10838 conf_free(ssh->conf);
10839 ssh->conf = conf_copy(conf);
10840 ssh_cache_conf_values(ssh);
10842 if (!ssh->bare_connection && rekeying) {
10843 if (!ssh->kex_in_progress) {
10844 do_ssh2_transport(ssh, rekeying, -1, NULL);
10845 } else if (rekey_mandatory) {
10846 ssh->deferred_rekey_reason = rekeying;
10852 * Called to send data down the SSH connection.
10854 static int ssh_send(void *handle, char *buf, int len)
10856 Ssh ssh = (Ssh) handle;
10858 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10861 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10863 return ssh_sendbuffer(ssh);
10867 * Called to query the current amount of buffered stdin data.
10869 static int ssh_sendbuffer(void *handle)
10871 Ssh ssh = (Ssh) handle;
10872 int override_value;
10874 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10878 * If the SSH socket itself has backed up, add the total backup
10879 * size on that to any individual buffer on the stdin channel.
10881 override_value = 0;
10882 if (ssh->throttled_all)
10883 override_value = ssh->overall_bufsize;
10885 if (ssh->version == 1) {
10886 return override_value;
10887 } else if (ssh->version == 2) {
10888 if (!ssh->mainchan)
10889 return override_value;
10891 return (override_value +
10892 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10899 * Called to set the size of the window from SSH's POV.
10901 static void ssh_size(void *handle, int width, int height)
10903 Ssh ssh = (Ssh) handle;
10904 struct Packet *pktout;
10906 ssh->term_width = width;
10907 ssh->term_height = height;
10909 switch (ssh->state) {
10910 case SSH_STATE_BEFORE_SIZE:
10911 case SSH_STATE_PREPACKET:
10912 case SSH_STATE_CLOSED:
10913 break; /* do nothing */
10914 case SSH_STATE_INTERMED:
10915 ssh->size_needed = TRUE; /* buffer for later */
10917 case SSH_STATE_SESSION:
10918 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10919 if (ssh->version == 1) {
10920 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10921 PKT_INT, ssh->term_height,
10922 PKT_INT, ssh->term_width,
10923 PKT_INT, 0, PKT_INT, 0, PKT_END);
10924 } else if (ssh->mainchan) {
10925 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10927 ssh2_pkt_adduint32(pktout, ssh->term_width);
10928 ssh2_pkt_adduint32(pktout, ssh->term_height);
10929 ssh2_pkt_adduint32(pktout, 0);
10930 ssh2_pkt_adduint32(pktout, 0);
10931 ssh2_pkt_send(ssh, pktout);
10939 * Return a list of the special codes that make sense in this
10942 static const struct telnet_special *ssh_get_specials(void *handle)
10944 static const struct telnet_special ssh1_ignore_special[] = {
10945 {"IGNORE message", TS_NOP}
10947 static const struct telnet_special ssh2_ignore_special[] = {
10948 {"IGNORE message", TS_NOP},
10950 static const struct telnet_special ssh2_rekey_special[] = {
10951 {"Repeat key exchange", TS_REKEY},
10953 static const struct telnet_special ssh2_session_specials[] = {
10956 /* These are the signal names defined by RFC 4254.
10957 * They include all the ISO C signals, but are a subset of the POSIX
10958 * required signals. */
10959 {"SIGINT (Interrupt)", TS_SIGINT},
10960 {"SIGTERM (Terminate)", TS_SIGTERM},
10961 {"SIGKILL (Kill)", TS_SIGKILL},
10962 {"SIGQUIT (Quit)", TS_SIGQUIT},
10963 {"SIGHUP (Hangup)", TS_SIGHUP},
10964 {"More signals", TS_SUBMENU},
10965 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10966 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10967 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10968 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10969 {NULL, TS_EXITMENU}
10971 static const struct telnet_special specials_end[] = {
10972 {NULL, TS_EXITMENU}
10974 /* XXX review this length for any changes: */
10975 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10976 lenof(ssh2_rekey_special) +
10977 lenof(ssh2_session_specials) +
10978 lenof(specials_end)];
10979 Ssh ssh = (Ssh) handle;
10981 #define ADD_SPECIALS(name) \
10983 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10984 memcpy(&ssh_specials[i], name, sizeof name); \
10985 i += lenof(name); \
10988 if (ssh->version == 1) {
10989 /* Don't bother offering IGNORE if we've decided the remote
10990 * won't cope with it, since we wouldn't bother sending it if
10992 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10993 ADD_SPECIALS(ssh1_ignore_special);
10994 } else if (ssh->version == 2) {
10995 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10996 ADD_SPECIALS(ssh2_ignore_special);
10997 if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection)
10998 ADD_SPECIALS(ssh2_rekey_special);
11000 ADD_SPECIALS(ssh2_session_specials);
11001 } /* else we're not ready yet */
11004 ADD_SPECIALS(specials_end);
11005 return ssh_specials;
11009 #undef ADD_SPECIALS
11013 * Send special codes. TS_EOF is useful for `plink', so you
11014 * can send an EOF and collect resulting output (e.g. `plink
11017 static void ssh_special(void *handle, Telnet_Special code)
11019 Ssh ssh = (Ssh) handle;
11020 struct Packet *pktout;
11022 if (code == TS_EOF) {
11023 if (ssh->state != SSH_STATE_SESSION) {
11025 * Buffer the EOF in case we are pre-SESSION, so we can
11026 * send it as soon as we reach SESSION.
11028 if (code == TS_EOF)
11029 ssh->eof_needed = TRUE;
11032 if (ssh->version == 1) {
11033 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
11034 } else if (ssh->mainchan) {
11035 sshfwd_write_eof(ssh->mainchan);
11036 ssh->send_ok = 0; /* now stop trying to read from stdin */
11038 logevent("Sent EOF message");
11039 } else if (code == TS_PING || code == TS_NOP) {
11040 if (ssh->state == SSH_STATE_CLOSED
11041 || ssh->state == SSH_STATE_PREPACKET) return;
11042 if (ssh->version == 1) {
11043 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
11044 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
11046 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
11047 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
11048 ssh2_pkt_addstring_start(pktout);
11049 ssh2_pkt_send_noqueue(ssh, pktout);
11052 } else if (code == TS_REKEY) {
11053 if (!ssh->kex_in_progress && !ssh->bare_connection &&
11054 ssh->version == 2) {
11055 do_ssh2_transport(ssh, "at user request", -1, NULL);
11057 } else if (code == TS_BRK) {
11058 if (ssh->state == SSH_STATE_CLOSED
11059 || ssh->state == SSH_STATE_PREPACKET) return;
11060 if (ssh->version == 1) {
11061 logevent("Unable to send BREAK signal in SSH-1");
11062 } else if (ssh->mainchan) {
11063 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
11064 ssh2_pkt_adduint32(pktout, 0); /* default break length */
11065 ssh2_pkt_send(ssh, pktout);
11068 /* Is is a POSIX signal? */
11069 char *signame = NULL;
11070 if (code == TS_SIGABRT) signame = "ABRT";
11071 if (code == TS_SIGALRM) signame = "ALRM";
11072 if (code == TS_SIGFPE) signame = "FPE";
11073 if (code == TS_SIGHUP) signame = "HUP";
11074 if (code == TS_SIGILL) signame = "ILL";
11075 if (code == TS_SIGINT) signame = "INT";
11076 if (code == TS_SIGKILL) signame = "KILL";
11077 if (code == TS_SIGPIPE) signame = "PIPE";
11078 if (code == TS_SIGQUIT) signame = "QUIT";
11079 if (code == TS_SIGSEGV) signame = "SEGV";
11080 if (code == TS_SIGTERM) signame = "TERM";
11081 if (code == TS_SIGUSR1) signame = "USR1";
11082 if (code == TS_SIGUSR2) signame = "USR2";
11083 /* The SSH-2 protocol does in principle support arbitrary named
11084 * signals, including signame@domain, but we don't support those. */
11086 /* It's a signal. */
11087 if (ssh->version == 2 && ssh->mainchan) {
11088 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
11089 ssh2_pkt_addstring(pktout, signame);
11090 ssh2_pkt_send(ssh, pktout);
11091 logeventf(ssh, "Sent signal SIG%s", signame);
11094 /* Never heard of it. Do nothing */
11099 void *new_sock_channel(void *handle, struct PortForwarding *pf)
11101 Ssh ssh = (Ssh) handle;
11102 struct ssh_channel *c;
11103 c = snew(struct ssh_channel);
11106 ssh2_channel_init(c);
11107 c->halfopen = TRUE;
11108 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
11110 add234(ssh->channels, c);
11114 unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx)
11116 struct ssh_channel *c;
11117 c = snew(struct ssh_channel);
11120 ssh2_channel_init(c);
11121 c->type = CHAN_SHARING;
11122 c->u.sharing.ctx = sharing_ctx;
11123 add234(ssh->channels, c);
11127 void ssh_delete_sharing_channel(Ssh ssh, unsigned localid)
11129 struct ssh_channel *c;
11131 c = find234(ssh->channels, &localid, ssh_channelfind);
11133 ssh_channel_destroy(c);
11136 void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type,
11137 const void *data, int datalen,
11138 const char *additional_log_text)
11140 struct Packet *pkt;
11142 pkt = ssh2_pkt_init(type);
11143 pkt->downstream_id = id;
11144 pkt->additional_log_text = additional_log_text;
11145 ssh2_pkt_adddata(pkt, data, datalen);
11146 ssh2_pkt_send(ssh, pkt);
11150 * This is called when stdout/stderr (the entity to which
11151 * from_backend sends data) manages to clear some backlog.
11153 static void ssh_unthrottle(void *handle, int bufsize)
11155 Ssh ssh = (Ssh) handle;
11158 if (ssh->version == 1) {
11159 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
11160 ssh->v1_stdout_throttling = 0;
11161 ssh_throttle_conn(ssh, -1);
11164 if (ssh->mainchan) {
11165 ssh2_set_window(ssh->mainchan,
11166 bufsize < ssh->mainchan->v.v2.locmaxwin ?
11167 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
11168 if (ssh_is_simple(ssh))
11171 buflimit = ssh->mainchan->v.v2.locmaxwin;
11172 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
11173 ssh->mainchan->throttling_conn = 0;
11174 ssh_throttle_conn(ssh, -1);
11180 * Now process any SSH connection data that was stashed in our
11181 * queue while we were frozen.
11183 ssh_process_queued_incoming_data(ssh);
11186 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
11188 struct ssh_channel *c = (struct ssh_channel *)channel;
11190 struct Packet *pktout;
11192 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
11194 if (ssh->version == 1) {
11195 send_packet(ssh, SSH1_MSG_PORT_OPEN,
11196 PKT_INT, c->localid,
11199 /* PKT_STR, <org:orgport>, */
11202 pktout = ssh2_chanopen_init(c, "direct-tcpip");
11204 char *trimmed_host = host_strduptrim(hostname);
11205 ssh2_pkt_addstring(pktout, trimmed_host);
11206 sfree(trimmed_host);
11208 ssh2_pkt_adduint32(pktout, port);
11210 * We make up values for the originator data; partly it's
11211 * too much hassle to keep track, and partly I'm not
11212 * convinced the server should be told details like that
11213 * about my local network configuration.
11214 * The "originator IP address" is syntactically a numeric
11215 * IP address, and some servers (e.g., Tectia) get upset
11216 * if it doesn't match this syntax.
11218 ssh2_pkt_addstring(pktout, "0.0.0.0");
11219 ssh2_pkt_adduint32(pktout, 0);
11220 ssh2_pkt_send(ssh, pktout);
11224 static int ssh_connected(void *handle)
11226 Ssh ssh = (Ssh) handle;
11227 return ssh->s != NULL;
11230 static int ssh_sendok(void *handle)
11232 Ssh ssh = (Ssh) handle;
11233 return ssh->send_ok;
11236 static int ssh_ldisc(void *handle, int option)
11238 Ssh ssh = (Ssh) handle;
11239 if (option == LD_ECHO)
11240 return ssh->echoing;
11241 if (option == LD_EDIT)
11242 return ssh->editing;
11246 static void ssh_provide_ldisc(void *handle, void *ldisc)
11248 Ssh ssh = (Ssh) handle;
11249 ssh->ldisc = ldisc;
11252 static void ssh_provide_logctx(void *handle, void *logctx)
11254 Ssh ssh = (Ssh) handle;
11255 ssh->logctx = logctx;
11258 static int ssh_return_exitcode(void *handle)
11260 Ssh ssh = (Ssh) handle;
11261 if (ssh->s != NULL)
11264 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
11268 * cfg_info for SSH is the protocol running in this session.
11269 * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare
11270 * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.)
11272 static int ssh_cfg_info(void *handle)
11274 Ssh ssh = (Ssh) handle;
11275 if (ssh->version == 0)
11276 return 0; /* don't know yet */
11277 else if (ssh->bare_connection)
11280 return ssh->version;
11284 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
11285 * that fails. This variable is the means by which scp.c can reach
11286 * into the SSH code and find out which one it got.
11288 extern int ssh_fallback_cmd(void *handle)
11290 Ssh ssh = (Ssh) handle;
11291 return ssh->fallback_cmd;
11294 Backend ssh_backend = {
11304 ssh_return_exitcode,
11308 ssh_provide_logctx,