17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 /* 64 was BUG_SSH2_DH_GEX, now spare */
166 #define BUG_SSH2_PK_SESSIONID 128
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 /* Enumeration values for fields in SSH-1 packets */
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
285 * which explains the theory behind these macros.
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
292 * - right-click ssh.c in the FileView
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
298 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
301 if (!ssh->t) ssh->t = snew(struct t); \
303 #define crFinish(z) } *crLine = 0; return (z); }
304 #define crFinishV } *crLine = 0; return; }
305 #define crReturn(z) \
307 *crLine =__LINE__; return (z); case __LINE__:;\
311 *crLine=__LINE__; return; case __LINE__:;\
313 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
314 #define crStopV do{ *crLine = 0; return; }while(0)
315 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
316 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
318 typedef struct ssh_tag *Ssh;
321 static struct Packet *ssh2_pkt_init(int pkt_type);
322 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323 static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324 static void ssh2_pkt_addstring_start(struct Packet *);
325 static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326 static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327 static void ssh2_pkt_addstring(struct Packet *, char *data);
328 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
329 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330 static int ssh2_pkt_construct(Ssh, struct Packet *);
331 static void ssh2_pkt_send(Ssh, struct Packet *);
332 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
333 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
339 * Buffer management constants. There are several of these for
340 * various different purposes:
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
359 #define SSH1_BUFFER_LIMIT 32768
360 #define SSH_MAX_BACKLOG 32768
361 #define OUR_V2_WINSIZE 16384
363 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
365 static void *nullmac_make_context(void)
369 static void nullmac_free_context(void *handle)
372 static void nullmac_key(void *handle, unsigned char *key)
375 static void nullmac_generate(void *handle, unsigned char *blk, int len,
379 static int nullmac_verify(void *handle, unsigned char *blk, int len,
384 const static struct ssh_mac ssh_mac_none = {
385 nullmac_make_context, nullmac_free_context, nullmac_key,
386 nullmac_generate, nullmac_verify, "none", 0
388 const static struct ssh_mac *macs[] = {
389 &ssh_sha1, &ssh_md5, &ssh_mac_none
391 const static struct ssh_mac *buggymacs[] = {
392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
395 static void *ssh_comp_none_init(void)
399 static void ssh_comp_none_cleanup(void *handle)
402 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
403 unsigned char **outblock, int *outlen)
407 static int ssh_comp_none_disable(void *handle)
411 const static struct ssh_compress ssh_comp_none = {
413 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_disable, NULL
417 extern const struct ssh_compress ssh_zlib;
418 const static struct ssh_compress *compressions[] = {
419 &ssh_zlib, &ssh_comp_none
422 enum { /* channel types */
427 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
431 * 2-3-4 tree storing channels.
434 Ssh ssh; /* pointer back to main context */
435 unsigned remoteid, localid;
438 * In SSH1, this value contains four bits:
440 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
441 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
443 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
445 * A channel is completely finished with when all four bits are set.
449 struct ssh1_data_channel {
452 struct ssh2_data_channel {
454 unsigned remwindow, remmaxpkt;
459 struct ssh_agent_channel {
460 unsigned char *message;
461 unsigned char msglen[4];
462 unsigned lensofar, totallen;
464 struct ssh_x11_channel {
467 struct ssh_pfd_channel {
474 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
475 * 2 use this structure in different ways, reflecting SSH 2's
476 * altogether saner approach to port forwarding.
478 * In SSH 1, you arrange a remote forwarding by sending the server
479 * the remote port number, and the local destination host:port.
480 * When a connection comes in, the server sends you back that
481 * host:port pair, and you connect to it. This is a ready-made
482 * security hole if you're not on the ball: a malicious server
483 * could send you back _any_ host:port pair, so if you trustingly
484 * connect to the address it gives you then you've just opened the
485 * entire inside of your corporate network just by connecting
486 * through it to a dodgy SSH server. Hence, we must store a list of
487 * host:port pairs we _are_ trying to forward to, and reject a
488 * connection request from the server if it's not in the list.
490 * In SSH 2, each side of the connection minds its own business and
491 * doesn't send unnecessary information to the other. You arrange a
492 * remote forwarding by sending the server just the remote port
493 * number. When a connection comes in, the server tells you which
494 * of its ports was connected to; and _you_ have to remember what
495 * local host:port pair went with that port number.
497 * Hence: in SSH 1 this structure stores host:port pairs we intend
498 * to allow connections to, and is indexed by those host:port
499 * pairs. In SSH 2 it stores a mapping from source port to
500 * destination host:port pair, and is indexed by source port.
502 struct ssh_rportfwd {
503 unsigned sport, dport;
510 unsigned long sequence;
515 long encrypted_len; /* for SSH2 total-size counting */
518 * State associated with packet logging
522 struct logblank_t *blanks;
525 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
526 struct Packet *pktin);
527 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
528 struct Packet *pktin);
529 static void ssh1_protocol_setup(Ssh ssh);
530 static void ssh2_protocol_setup(Ssh ssh);
531 static void ssh_size(void *handle, int width, int height);
532 static void ssh_special(void *handle, Telnet_Special);
533 static int ssh2_try_send(struct ssh_channel *c);
534 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
535 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
536 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
537 static int ssh_sendbuffer(void *handle);
538 static void ssh_do_close(Ssh ssh);
539 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
540 static int ssh2_pkt_getbool(struct Packet *pkt);
541 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
542 static void ssh2_timer(void *ctx, long now);
543 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
544 struct Packet *pktin);
546 struct rdpkt1_state_tag {
547 long len, pad, biglen, to_read;
548 unsigned long realcrc, gotcrc;
552 struct Packet *pktin;
555 struct rdpkt2_state_tag {
556 long len, pad, payload, packetlen, maclen;
559 unsigned long incoming_sequence;
560 struct Packet *pktin;
563 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
566 const struct plug_function_table *fn;
567 /* the above field _must_ be first in the structure */
569 SHA_State exhash, exhashbase;
576 unsigned char session_key[32];
578 int v1_remote_protoflags;
579 int v1_local_protoflags;
580 int agentfwd_enabled;
583 const struct ssh_cipher *cipher;
586 const struct ssh2_cipher *cscipher, *sccipher;
587 void *cs_cipher_ctx, *sc_cipher_ctx;
588 const struct ssh_mac *csmac, *scmac;
589 void *cs_mac_ctx, *sc_mac_ctx;
590 const struct ssh_compress *cscomp, *sccomp;
591 void *cs_comp_ctx, *sc_comp_ctx;
592 const struct ssh_kex *kex;
593 const struct ssh_signkey *hostkey;
594 unsigned char v2_session_id[20];
600 int echoing, editing;
604 int ospeed, ispeed; /* temporaries */
605 int term_width, term_height;
607 tree234 *channels; /* indexed by local id */
608 struct ssh_channel *mainchan; /* primary session channel */
615 SSH_STATE_BEFORE_SIZE,
621 int size_needed, eof_needed;
623 struct Packet **queue;
624 int queuelen, queuesize;
626 unsigned char *deferred_send_data;
627 int deferred_len, deferred_size;
630 * Gross hack: pscp will try to start SFTP but fall back to
631 * scp1 if that fails. This variable is the means by which
632 * scp.c can reach into the SSH code and find out which one it
638 * Used for username and password input.
640 char *userpass_input_buffer;
641 int userpass_input_buflen;
642 int userpass_input_bufpos;
643 int userpass_input_echo;
645 char *portfwd_strptr;
651 int v1_throttle_count;
654 int v1_stdout_throttling;
655 int v2_outgoing_sequence;
657 int ssh1_rdpkt_crstate;
658 int ssh2_rdpkt_crstate;
659 int do_ssh_init_crstate;
660 int ssh_gotdata_crstate;
661 int do_ssh1_login_crstate;
662 int do_ssh1_connection_crstate;
663 int do_ssh2_transport_crstate;
664 int do_ssh2_authconn_crstate;
666 void *do_ssh_init_state;
667 void *do_ssh1_login_state;
668 void *do_ssh2_transport_state;
669 void *do_ssh2_authconn_state;
671 struct rdpkt1_state_tag rdpkt1_state;
672 struct rdpkt2_state_tag rdpkt2_state;
674 /* ssh1 and ssh2 use this for different things, but both use it */
675 int protocol_initial_phase_done;
677 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
679 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
682 * We maintain a full _copy_ of a Config structure here, not
683 * merely a pointer to it. That way, when we're passed a new
684 * one for reconfiguration, we can check the differences and
685 * potentially reconfigure port forwardings etc in mid-session.
690 * Used to transfer data back from async agent callbacks.
692 void *agent_response;
693 int agent_response_len;
696 * Dispatch table for packet types that we may have to deal
699 handler_fn_t packet_dispatch[256];
702 * This module deals with sending keepalives.
707 * Track incoming and outgoing data sizes and time, for
710 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
715 #define MAX_DATA_BEFORE_REKEY (0x40000000UL)
716 #define REKEY_TIMEOUT (3600 * TICKSPERSEC)
718 #define logevent(s) logevent(ssh->frontend, s)
720 /* logevent, only printf-formatted. */
721 static void logeventf(Ssh ssh, const char *fmt, ...)
727 buf = dupvprintf(fmt, ap);
733 #define bombout(msg) \
735 char *text = dupprintf msg; \
738 connection_fatal(ssh->frontend, "%s", text); \
742 /* Functions to leave bits out of the SSH packet log file. */
744 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
746 if (ssh->cfg.logomitpass)
747 pkt->logmode = blanktype;
750 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
752 if (ssh->cfg.logomitdata)
753 pkt->logmode = blanktype;
756 static void end_log_omission(Ssh ssh, struct Packet *pkt)
758 pkt->logmode = PKTLOG_EMIT;
761 static int ssh_channelcmp(void *av, void *bv)
763 struct ssh_channel *a = (struct ssh_channel *) av;
764 struct ssh_channel *b = (struct ssh_channel *) bv;
765 if (a->localid < b->localid)
767 if (a->localid > b->localid)
771 static int ssh_channelfind(void *av, void *bv)
773 unsigned *a = (unsigned *) av;
774 struct ssh_channel *b = (struct ssh_channel *) bv;
782 static int ssh_rportcmp_ssh1(void *av, void *bv)
784 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
785 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
787 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
788 return i < 0 ? -1 : +1;
789 if (a->dport > b->dport)
791 if (a->dport < b->dport)
796 static int ssh_rportcmp_ssh2(void *av, void *bv)
798 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
799 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
801 if (a->sport > b->sport)
803 if (a->sport < b->sport)
808 static int alloc_channel_id(Ssh ssh)
810 const unsigned CHANNEL_NUMBER_OFFSET = 256;
811 unsigned low, high, mid;
813 struct ssh_channel *c;
816 * First-fit allocation of channel numbers: always pick the
817 * lowest unused one. To do this, binary-search using the
818 * counted B-tree to find the largest channel ID which is in a
819 * contiguous sequence from the beginning. (Precisely
820 * everything in that sequence must have ID equal to its tree
821 * index plus CHANNEL_NUMBER_OFFSET.)
823 tsize = count234(ssh->channels);
827 while (high - low > 1) {
828 mid = (high + low) / 2;
829 c = index234(ssh->channels, mid);
830 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
831 low = mid; /* this one is fine */
833 high = mid; /* this one is past it */
836 * Now low points to either -1, or the tree index of the
837 * largest ID in the initial sequence.
840 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
841 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
843 return low + 1 + CHANNEL_NUMBER_OFFSET;
846 static void c_write(Ssh ssh, const char *buf, int len)
848 if ((flags & FLAG_STDERR)) {
850 for (i = 0; i < len; i++)
852 fputc(buf[i], stderr);
855 from_backend(ssh->frontend, 1, buf, len);
858 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
861 for (i = 0; i < len; i++) {
863 c_write(ssh, "\r\n", 2);
864 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
865 c_write(ssh, buf + i, 1);
869 static void c_write_str(Ssh ssh, const char *buf)
871 c_write(ssh, buf, strlen(buf));
874 static void ssh_free_packet(struct Packet *pkt)
879 static struct Packet *ssh_new_packet(void)
881 struct Packet *pkt = snew(struct Packet);
885 pkt->logmode = PKTLOG_EMIT;
893 * Collect incoming data in the incoming packet buffer.
894 * Decipher and verify the packet when it is completely read.
895 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
896 * Update the *data and *datalen variables.
897 * Return a Packet structure when a packet is completed.
899 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
901 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
903 crBegin(ssh->ssh1_rdpkt_crstate);
905 st->pktin = ssh_new_packet();
908 st->pktin->length = 0;
910 for (st->i = st->len = 0; st->i < 4; st->i++) {
911 while ((*datalen) == 0)
913 st->len = (st->len << 8) + **data;
914 (*data)++, (*datalen)--;
917 st->pad = 8 - (st->len % 8);
918 st->biglen = st->len + st->pad;
919 st->pktin->length = st->len - 5;
921 if (st->biglen < 0) {
922 bombout(("Extremely large packet length from server suggests"
923 " data stream corruption"));
924 ssh_free_packet(st->pktin);
928 st->pktin->maxlen = st->biglen;
929 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
931 st->to_read = st->biglen;
932 st->p = st->pktin->data;
933 while (st->to_read > 0) {
934 st->chunk = st->to_read;
935 while ((*datalen) == 0)
937 if (st->chunk > (*datalen))
938 st->chunk = (*datalen);
939 memcpy(st->p, *data, st->chunk);
941 *datalen -= st->chunk;
943 st->to_read -= st->chunk;
946 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
948 bombout(("Network attack (CRC compensation) detected!"));
949 ssh_free_packet(st->pktin);
954 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
956 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
957 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
958 if (st->gotcrc != st->realcrc) {
959 bombout(("Incorrect CRC received on packet"));
960 ssh_free_packet(st->pktin);
964 st->pktin->body = st->pktin->data + st->pad + 1;
965 st->pktin->savedpos = 0;
967 if (ssh->v1_compressing) {
968 unsigned char *decompblk;
970 if (!zlib_decompress_block(ssh->sc_comp_ctx,
971 st->pktin->body - 1, st->pktin->length + 1,
972 &decompblk, &decomplen)) {
973 bombout(("Zlib decompression encountered invalid data"));
974 ssh_free_packet(st->pktin);
978 if (st->pktin->maxlen < st->pad + decomplen) {
979 st->pktin->maxlen = st->pad + decomplen;
980 st->pktin->data = sresize(st->pktin->data,
981 st->pktin->maxlen + APIEXTRA,
983 st->pktin->body = st->pktin->data + st->pad + 1;
986 memcpy(st->pktin->body - 1, decompblk, decomplen);
988 st->pktin->length = decomplen - 1;
991 st->pktin->type = st->pktin->body[-1];
994 * Log incoming packet, possibly omitting sensitive fields.
998 struct logblank_t blank;
999 if (ssh->cfg.logomitdata) {
1000 int do_blank = FALSE, blank_prefix = 0;
1001 /* "Session data" packets - omit the data field */
1002 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1003 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1004 do_blank = TRUE; blank_prefix = 0;
1005 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1006 do_blank = TRUE; blank_prefix = 4;
1009 blank.offset = blank_prefix;
1010 blank.len = st->pktin->length;
1011 blank.type = PKTLOG_OMIT;
1015 log_packet(ssh->logctx,
1016 PKT_INCOMING, st->pktin->type,
1017 ssh1_pkt_type(st->pktin->type),
1018 st->pktin->body, st->pktin->length,
1022 crFinish(st->pktin);
1025 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1027 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1029 crBegin(ssh->ssh2_rdpkt_crstate);
1031 st->pktin = ssh_new_packet();
1033 st->pktin->type = 0;
1034 st->pktin->length = 0;
1036 st->cipherblk = ssh->sccipher->blksize;
1039 if (st->cipherblk < 8)
1042 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1045 * Acquire and decrypt the first block of the packet. This will
1046 * contain the length and padding details.
1048 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1049 while ((*datalen) == 0)
1051 st->pktin->data[st->i] = *(*data)++;
1056 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1057 st->pktin->data, st->cipherblk);
1060 * Now get the length and padding figures.
1062 st->len = GET_32BIT(st->pktin->data);
1063 st->pad = st->pktin->data[4];
1066 * _Completely_ silly lengths should be stomped on before they
1067 * do us any more damage.
1069 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1070 bombout(("Incoming packet was garbled on decryption"));
1071 ssh_free_packet(st->pktin);
1076 * This enables us to deduce the payload length.
1078 st->payload = st->len - st->pad - 1;
1080 st->pktin->length = st->payload + 5;
1083 * So now we can work out the total packet length.
1085 st->packetlen = st->len + 4;
1086 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1089 * Allocate memory for the rest of the packet.
1091 st->pktin->maxlen = st->packetlen + st->maclen;
1092 st->pktin->data = sresize(st->pktin->data,
1093 st->pktin->maxlen + APIEXTRA,
1097 * Read and decrypt the remainder of the packet.
1099 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1101 while ((*datalen) == 0)
1103 st->pktin->data[st->i] = *(*data)++;
1106 /* Decrypt everything _except_ the MAC. */
1108 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1109 st->pktin->data + st->cipherblk,
1110 st->packetlen - st->cipherblk);
1112 st->pktin->encrypted_len = st->packetlen;
1118 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1119 st->incoming_sequence)) {
1120 bombout(("Incorrect MAC received on packet"));
1121 ssh_free_packet(st->pktin);
1125 st->pktin->sequence = st->incoming_sequence++;
1128 * Decompress packet payload.
1131 unsigned char *newpayload;
1134 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1135 st->pktin->data + 5, st->pktin->length - 5,
1136 &newpayload, &newlen)) {
1137 if (st->pktin->maxlen < newlen + 5) {
1138 st->pktin->maxlen = newlen + 5;
1139 st->pktin->data = sresize(st->pktin->data,
1140 st->pktin->maxlen + APIEXTRA,
1143 st->pktin->length = 5 + newlen;
1144 memcpy(st->pktin->data + 5, newpayload, newlen);
1149 st->pktin->savedpos = 6;
1150 st->pktin->body = st->pktin->data;
1151 st->pktin->type = st->pktin->data[5];
1154 * Log incoming packet, possibly omitting sensitive fields.
1158 struct logblank_t blank;
1159 if (ssh->cfg.logomitdata) {
1160 int do_blank = FALSE, blank_prefix = 0;
1161 /* "Session data" packets - omit the data field */
1162 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1163 do_blank = TRUE; blank_prefix = 4;
1164 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1165 do_blank = TRUE; blank_prefix = 8;
1168 blank.offset = blank_prefix;
1169 blank.len = (st->pktin->length-6) - blank_prefix;
1170 blank.type = PKTLOG_OMIT;
1174 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1175 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1176 st->pktin->data+6, st->pktin->length-6,
1180 crFinish(st->pktin);
1183 static void ssh1_pktout_size(struct Packet *pkt, int len)
1187 len += 5; /* type and CRC */
1188 pad = 8 - (len % 8);
1191 pkt->length = len - 5;
1192 if (pkt->maxlen < biglen) {
1193 pkt->maxlen = biglen;
1194 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1196 pkt->body = pkt->data + 4 + pad + 1;
1199 static struct Packet *s_wrpkt_start(int type, int len)
1201 struct Packet *pkt = ssh_new_packet();
1202 ssh1_pktout_size(pkt, len);
1204 /* Initialise log omission state */
1210 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1216 * XXX various versions of SC (including 8.8.4) screw up the
1217 * register allocation in this function and use the same register
1218 * (D6) for len and as a temporary, with predictable results. The
1219 * following sledgehammer prevents this.
1225 pkt->body[-1] = pkt->type;
1228 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1229 ssh1_pkt_type(pkt->type),
1230 pkt->body, pkt->length,
1231 pkt->nblanks, pkt->blanks);
1232 sfree(pkt->blanks); pkt->blanks = NULL;
1235 if (ssh->v1_compressing) {
1236 unsigned char *compblk;
1238 zlib_compress_block(ssh->cs_comp_ctx,
1239 pkt->body - 1, pkt->length + 1,
1240 &compblk, &complen);
1241 ssh1_pktout_size(pkt, complen - 1);
1242 memcpy(pkt->body - 1, compblk, complen);
1246 len = pkt->length + 5; /* type and CRC */
1247 pad = 8 - (len % 8);
1250 for (i = 0; i < pad; i++)
1251 pkt->data[i + 4] = random_byte();
1252 crc = crc32_compute(pkt->data + 4, biglen - 4);
1253 PUT_32BIT(pkt->data + biglen, crc);
1254 PUT_32BIT(pkt->data, len);
1257 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1262 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1265 len = s_wrpkt_prepare(ssh, pkt);
1266 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1267 if (backlog > SSH_MAX_BACKLOG)
1268 ssh_throttle_all(ssh, 1, backlog);
1271 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1274 len = s_wrpkt_prepare(ssh, pkt);
1275 if (ssh->deferred_len + len > ssh->deferred_size) {
1276 ssh->deferred_size = ssh->deferred_len + len + 128;
1277 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1281 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1282 ssh->deferred_len += len;
1286 * Construct a packet with the specified contents.
1288 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1289 va_list ap1, va_list ap2)
1291 unsigned char *p, *argp, argchar;
1292 unsigned long argint;
1293 int pktlen, argtype, arglen;
1298 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1301 (void) va_arg(ap1, int);
1305 (void) va_arg(ap1, int);
1309 (void) va_arg(ap1, unsigned char *);
1310 arglen = va_arg(ap1, int);
1314 argp = va_arg(ap1, unsigned char *);
1315 arglen = strlen((char *)argp);
1316 pktlen += 4 + arglen;
1319 bn = va_arg(ap1, Bignum);
1320 pktlen += ssh1_bignum_length(bn);
1325 /* ignore this pass */
1332 pkt = s_wrpkt_start(pkttype, pktlen);
1335 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1336 int offset = p - pkt->body, len = 0;
1338 /* Actual fields in the packet */
1340 argint = va_arg(ap2, int);
1341 PUT_32BIT(p, argint);
1345 argchar = (unsigned char) va_arg(ap2, int);
1350 argp = va_arg(ap2, unsigned char *);
1351 arglen = va_arg(ap2, int);
1352 memcpy(p, argp, arglen);
1356 argp = va_arg(ap2, unsigned char *);
1357 arglen = strlen((char *)argp);
1358 PUT_32BIT(p, arglen);
1359 memcpy(p + 4, argp, arglen);
1363 bn = va_arg(ap2, Bignum);
1364 len = ssh1_write_bignum(p, bn);
1366 /* Tokens for modifications to packet logging */
1368 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1371 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1374 end_log_omission(ssh, pkt);
1378 /* Deal with logfile omission, if required. */
1379 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1381 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1383 pkt->blanks[pkt->nblanks-1].offset = offset;
1384 pkt->blanks[pkt->nblanks-1].len = len;
1385 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1392 static void send_packet(Ssh ssh, int pkttype, ...)
1396 va_start(ap1, pkttype);
1397 va_start(ap2, pkttype);
1398 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1402 ssh_free_packet(pkt);
1405 static void defer_packet(Ssh ssh, int pkttype, ...)
1409 va_start(ap1, pkttype);
1410 va_start(ap2, pkttype);
1411 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1414 s_wrpkt_defer(ssh, pkt);
1415 ssh_free_packet(pkt);
1418 static int ssh_versioncmp(char *a, char *b)
1421 unsigned long av, bv;
1423 av = strtoul(a, &ae, 10);
1424 bv = strtoul(b, &be, 10);
1426 return (av < bv ? -1 : +1);
1431 av = strtoul(ae, &ae, 10);
1432 bv = strtoul(be, &be, 10);
1434 return (av < bv ? -1 : +1);
1439 * Utility routines for putting an SSH-protocol `string' and
1440 * `uint32' into a SHA state.
1443 static void sha_string(SHA_State * s, void *str, int len)
1445 unsigned char lenblk[4];
1446 PUT_32BIT(lenblk, len);
1447 SHA_Bytes(s, lenblk, 4);
1448 SHA_Bytes(s, str, len);
1451 static void sha_uint32(SHA_State * s, unsigned i)
1453 unsigned char intblk[4];
1454 PUT_32BIT(intblk, i);
1455 SHA_Bytes(s, intblk, 4);
1459 * SSH2 packet construction functions.
1461 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1463 if (pkt->maxlen < length) {
1464 pkt->maxlen = length + 256;
1465 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1468 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1470 if (pkt->logmode != PKTLOG_EMIT) {
1472 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1473 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1474 pkt->blanks[pkt->nblanks-1].len = len;
1475 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1478 ssh2_pkt_ensure(pkt, pkt->length);
1479 memcpy(pkt->data + pkt->length - len, data, len);
1481 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1483 ssh2_pkt_adddata(pkt, &byte, 1);
1485 static struct Packet *ssh2_pkt_init(int pkt_type)
1487 struct Packet *pkt = ssh_new_packet();
1489 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1492 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1494 ssh2_pkt_adddata(pkt, &value, 1);
1496 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1499 PUT_32BIT(x, value);
1500 ssh2_pkt_adddata(pkt, x, 4);
1502 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1504 ssh2_pkt_adduint32(pkt, 0);
1505 pkt->savedpos = pkt->length;
1507 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1509 ssh2_pkt_adddata(pkt, data, strlen(data));
1510 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1512 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1514 ssh2_pkt_adddata(pkt, data, len);
1515 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1517 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1519 ssh2_pkt_addstring_start(pkt);
1520 ssh2_pkt_addstring_str(pkt, data);
1522 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1525 int i, n = (bignum_bitcount(b) + 7) / 8;
1526 p = snewn(n + 1, unsigned char);
1528 fatalbox("out of memory");
1530 for (i = 1; i <= n; i++)
1531 p[i] = bignum_byte(b, n - i);
1533 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1535 memmove(p, p + i, n + 1 - i);
1539 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1543 p = ssh2_mpint_fmt(b, &len);
1544 ssh2_pkt_addstring_start(pkt);
1545 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1550 * Construct an SSH2 final-form packet: compress it, encrypt it,
1551 * put the MAC on it. Final packet, ready to be sent, is stored in
1552 * pkt->data. Total length is returned.
1554 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1556 int cipherblk, maclen, padding, i;
1559 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1560 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1561 pkt->data + 6, pkt->length - 6,
1562 pkt->nblanks, pkt->blanks);
1563 sfree(pkt->blanks); pkt->blanks = NULL;
1567 * Compress packet payload.
1570 unsigned char *newpayload;
1573 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1575 &newpayload, &newlen)) {
1577 ssh2_pkt_adddata(pkt, newpayload, newlen);
1583 * Add padding. At least four bytes, and must also bring total
1584 * length (minus MAC) up to a multiple of the block size.
1586 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1587 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1590 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1591 maclen = ssh->csmac ? ssh->csmac->len : 0;
1592 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1593 pkt->data[4] = padding;
1594 for (i = 0; i < padding; i++)
1595 pkt->data[pkt->length + i] = random_byte();
1596 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1598 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1599 pkt->length + padding,
1600 ssh->v2_outgoing_sequence);
1601 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1604 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1605 pkt->data, pkt->length + padding);
1607 pkt->encrypted_len = pkt->length + padding;
1609 /* Ready-to-send packet starts at pkt->data. We return length. */
1610 return pkt->length + padding + maclen;
1614 * Routines called from the main SSH code to send packets. There
1615 * are quite a few of these, because we have two separate
1616 * mechanisms for delaying the sending of packets:
1618 * - In order to send an IGNORE message and a password message in
1619 * a single fixed-length blob, we require the ability to
1620 * concatenate the encrypted forms of those two packets _into_ a
1621 * single blob and then pass it to our <network.h> transport
1622 * layer in one go. Hence, there's a deferment mechanism which
1623 * works after packet encryption.
1625 * - In order to avoid sending any connection-layer messages
1626 * during repeat key exchange, we have to queue up any such
1627 * outgoing messages _before_ they are encrypted (and in
1628 * particular before they're allocated sequence numbers), and
1629 * then send them once we've finished.
1631 * I call these mechanisms `defer' and `queue' respectively, so as
1632 * to distinguish them reasonably easily.
1634 * The functions send_noqueue() and defer_noqueue() free the packet
1635 * structure they are passed. Every outgoing packet goes through
1636 * precisely one of these functions in its life; packets passed to
1637 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1638 * these or get queued, and then when the queue is later emptied
1639 * the packets are all passed to defer_noqueue().
1643 * Send an SSH2 packet immediately, without queuing or deferring.
1645 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1649 len = ssh2_pkt_construct(ssh, pkt);
1650 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1651 if (backlog > SSH_MAX_BACKLOG)
1652 ssh_throttle_all(ssh, 1, backlog);
1654 ssh->outgoing_data_size += pkt->encrypted_len;
1655 if (!ssh->kex_in_progress &&
1656 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1657 do_ssh2_transport(ssh, "Initiating key re-exchange "
1658 "(too much data sent)", -1, NULL);
1660 ssh_free_packet(pkt);
1664 * Defer an SSH2 packet.
1666 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1668 int len = ssh2_pkt_construct(ssh, pkt);
1669 if (ssh->deferred_len + len > ssh->deferred_size) {
1670 ssh->deferred_size = ssh->deferred_len + len + 128;
1671 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1675 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1676 ssh->deferred_len += len;
1677 ssh->deferred_data_size += pkt->encrypted_len;
1678 ssh_free_packet(pkt);
1682 * Queue an SSH2 packet.
1684 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1686 assert(ssh->queueing);
1688 if (ssh->queuelen >= ssh->queuesize) {
1689 ssh->queuesize = ssh->queuelen + 32;
1690 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1693 ssh->queue[ssh->queuelen++] = pkt;
1697 * Either queue or send a packet, depending on whether queueing is
1700 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1703 ssh2_pkt_queue(ssh, pkt);
1705 ssh2_pkt_send_noqueue(ssh, pkt);
1709 * Either queue or defer a packet, depending on whether queueing is
1712 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1715 ssh2_pkt_queue(ssh, pkt);
1717 ssh2_pkt_defer_noqueue(ssh, pkt);
1721 * Send the whole deferred data block constructed by
1722 * ssh2_pkt_defer() or SSH1's defer_packet().
1724 * The expected use of the defer mechanism is that you call
1725 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1726 * not currently queueing, this simply sets up deferred_send_data
1727 * and then sends it. If we _are_ currently queueing, the calls to
1728 * ssh2_pkt_defer() put the deferred packets on to the queue
1729 * instead, and therefore ssh_pkt_defersend() has no deferred data
1730 * to send. Hence, there's no need to make it conditional on
1733 static void ssh_pkt_defersend(Ssh ssh)
1736 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1738 ssh->deferred_len = ssh->deferred_size = 0;
1739 sfree(ssh->deferred_send_data);
1740 ssh->deferred_send_data = NULL;
1741 if (backlog > SSH_MAX_BACKLOG)
1742 ssh_throttle_all(ssh, 1, backlog);
1744 ssh->outgoing_data_size += ssh->deferred_data_size;
1745 if (!ssh->kex_in_progress &&
1746 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1747 do_ssh2_transport(ssh, "Initiating key re-exchange "
1748 "(too much data sent)", -1, NULL);
1749 ssh->deferred_data_size = 0;
1753 * Send all queued SSH2 packets. We send them by means of
1754 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1755 * packets that needed to be lumped together.
1757 static void ssh2_pkt_queuesend(Ssh ssh)
1761 assert(!ssh->queueing);
1763 for (i = 0; i < ssh->queuelen; i++)
1764 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1767 ssh_pkt_defersend(ssh);
1771 void bndebug(char *string, Bignum b)
1775 p = ssh2_mpint_fmt(b, &len);
1776 debug(("%s", string));
1777 for (i = 0; i < len; i++)
1778 debug((" %02x", p[i]));
1784 static void sha_mpint(SHA_State * s, Bignum b)
1788 p = ssh2_mpint_fmt(b, &len);
1789 sha_string(s, p, len);
1794 * Packet decode functions for both SSH1 and SSH2.
1796 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1798 unsigned long value;
1799 if (pkt->length - pkt->savedpos < 4)
1800 return 0; /* arrgh, no way to decline (FIXME?) */
1801 value = GET_32BIT(pkt->body + pkt->savedpos);
1805 static int ssh2_pkt_getbool(struct Packet *pkt)
1807 unsigned long value;
1808 if (pkt->length - pkt->savedpos < 1)
1809 return 0; /* arrgh, no way to decline (FIXME?) */
1810 value = pkt->body[pkt->savedpos] != 0;
1814 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1819 if (pkt->length - pkt->savedpos < 4)
1821 len = GET_32BIT(pkt->body + pkt->savedpos);
1826 if (pkt->length - pkt->savedpos < *length)
1828 *p = (char *)(pkt->body + pkt->savedpos);
1829 pkt->savedpos += *length;
1831 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1833 if (pkt->length - pkt->savedpos < length)
1835 pkt->savedpos += length;
1836 return pkt->body + (pkt->savedpos - length);
1838 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1839 unsigned char **keystr)
1843 j = makekey(pkt->body + pkt->savedpos,
1844 pkt->length - pkt->savedpos,
1851 assert(pkt->savedpos < pkt->length);
1855 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1860 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1861 pkt->length - pkt->savedpos, &b);
1869 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1875 ssh_pkt_getstring(pkt, &p, &length);
1880 b = bignum_from_bytes((unsigned char *)p, length);
1885 * Helper function to add an SSH2 signature blob to a packet.
1886 * Expects to be shown the public key blob as well as the signature
1887 * blob. Normally works just like ssh2_pkt_addstring, but will
1888 * fiddle with the signature packet if necessary for
1889 * BUG_SSH2_RSA_PADDING.
1891 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1892 void *pkblob_v, int pkblob_len,
1893 void *sigblob_v, int sigblob_len)
1895 unsigned char *pkblob = (unsigned char *)pkblob_v;
1896 unsigned char *sigblob = (unsigned char *)sigblob_v;
1898 /* dmemdump(pkblob, pkblob_len); */
1899 /* dmemdump(sigblob, sigblob_len); */
1902 * See if this is in fact an ssh-rsa signature and a buggy
1903 * server; otherwise we can just do this the easy way.
1905 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1906 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1907 int pos, len, siglen;
1910 * Find the byte length of the modulus.
1913 pos = 4+7; /* skip over "ssh-rsa" */
1914 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1915 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1916 pos += 4; /* find modulus itself */
1917 while (len > 0 && pkblob[pos] == 0)
1919 /* debug(("modulus length is %d\n", len)); */
1922 * Now find the signature integer.
1924 pos = 4+7; /* skip over "ssh-rsa" */
1925 siglen = GET_32BIT(sigblob+pos);
1926 /* debug(("signature length is %d\n", siglen)); */
1928 if (len != siglen) {
1929 unsigned char newlen[4];
1930 ssh2_pkt_addstring_start(pkt);
1931 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1932 /* dmemdump(sigblob, pos); */
1933 pos += 4; /* point to start of actual sig */
1934 PUT_32BIT(newlen, len);
1935 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1936 /* dmemdump(newlen, 4); */
1938 while (len-- > siglen) {
1939 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1940 /* dmemdump(newlen, 1); */
1942 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1943 /* dmemdump(sigblob+pos, siglen); */
1947 /* Otherwise fall through and do it the easy way. */
1950 ssh2_pkt_addstring_start(pkt);
1951 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1955 * Examine the remote side's version string and compare it against
1956 * a list of known buggy implementations.
1958 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1960 char *imp; /* pointer to implementation part */
1962 imp += strcspn(imp, "-");
1964 imp += strcspn(imp, "-");
1967 ssh->remote_bugs = 0;
1969 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1970 (ssh->cfg.sshbug_ignore1 == AUTO &&
1971 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1972 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1973 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1974 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1976 * These versions don't support SSH1_MSG_IGNORE, so we have
1977 * to use a different defence against password length
1980 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1981 logevent("We believe remote version has SSH1 ignore bug");
1984 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1985 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1986 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1988 * These versions need a plain password sent; they can't
1989 * handle having a null and a random length of data after
1992 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1993 logevent("We believe remote version needs a plain SSH1 password");
1996 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1997 (ssh->cfg.sshbug_rsa1 == AUTO &&
1998 (!strcmp(imp, "Cisco-1.25")))) {
2000 * These versions apparently have no clue whatever about
2001 * RSA authentication and will panic and die if they see
2002 * an AUTH_RSA message.
2004 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2005 logevent("We believe remote version can't handle RSA authentication");
2008 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2009 (ssh->cfg.sshbug_hmac2 == AUTO &&
2010 !wc_match("* VShell", imp) &&
2011 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2012 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2013 wc_match("2.1 *", imp)))) {
2015 * These versions have the HMAC bug.
2017 ssh->remote_bugs |= BUG_SSH2_HMAC;
2018 logevent("We believe remote version has SSH2 HMAC bug");
2021 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2022 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2023 !wc_match("* VShell", imp) &&
2024 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2026 * These versions have the key-derivation bug (failing to
2027 * include the literal shared secret in the hashes that
2028 * generate the keys).
2030 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2031 logevent("We believe remote version has SSH2 key-derivation bug");
2034 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2035 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2036 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2037 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2039 * These versions have the SSH2 RSA padding bug.
2041 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2042 logevent("We believe remote version has SSH2 RSA padding bug");
2045 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2046 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2047 wc_match("OpenSSH_2.[0-2]*", imp))) {
2049 * These versions have the SSH2 session-ID bug in
2050 * public-key authentication.
2052 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2053 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2058 * The `software version' part of an SSH version string is required
2059 * to contain no spaces or minus signs.
2061 static void ssh_fix_verstring(char *str)
2063 /* Eat "SSH-<protoversion>-". */
2064 assert(*str == 'S'); str++;
2065 assert(*str == 'S'); str++;
2066 assert(*str == 'H'); str++;
2067 assert(*str == '-'); str++;
2068 while (*str && *str != '-') str++;
2069 assert(*str == '-'); str++;
2071 /* Convert minus signs and spaces in the remaining string into
2074 if (*str == '-' || *str == ' ')
2080 static int do_ssh_init(Ssh ssh, unsigned char c)
2082 struct do_ssh_init_state {
2090 crState(do_ssh_init_state);
2092 crBegin(ssh->do_ssh_init_crstate);
2094 /* Search for the string "SSH-" in the input. */
2097 static const int transS[] = { 1, 2, 2, 1 };
2098 static const int transH[] = { 0, 0, 3, 0 };
2099 static const int transminus[] = { 0, 0, 0, -1 };
2101 s->i = transS[s->i];
2103 s->i = transH[s->i];
2105 s->i = transminus[s->i];
2110 crReturn(1); /* get another character */
2114 s->vstring = snewn(s->vstrsize, char);
2115 strcpy(s->vstring, "SSH-");
2119 crReturn(1); /* get another char */
2120 if (s->vslen >= s->vstrsize - 1) {
2122 s->vstring = sresize(s->vstring, s->vstrsize, char);
2124 s->vstring[s->vslen++] = c;
2127 s->version[s->i] = '\0';
2129 } else if (s->i < sizeof(s->version) - 1)
2130 s->version[s->i++] = c;
2131 } else if (c == '\012')
2135 ssh->agentfwd_enabled = FALSE;
2136 ssh->rdpkt2_state.incoming_sequence = 0;
2138 s->vstring[s->vslen] = 0;
2139 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2142 vlog = snewn(20 + s->vslen, char);
2143 sprintf(vlog, "Server version: %s", s->vstring);
2147 ssh_detect_bugs(ssh, s->vstring);
2150 * Decide which SSH protocol version to support.
2153 /* Anything strictly below "2.0" means protocol 1 is supported. */
2154 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2155 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2156 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2158 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2159 bombout(("SSH protocol version 1 required by user but not provided by server"));
2162 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2163 bombout(("SSH protocol version 2 required by user but not provided by server"));
2170 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2172 * Construct a v2 version string.
2174 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2178 * Construct a v1 version string.
2180 verstring = dupprintf("SSH-%s-%s\012",
2181 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2182 s->version : "1.5"),
2187 ssh_fix_verstring(verstring);
2189 if (ssh->version == 2) {
2191 * Hash our version string and their version string.
2193 SHA_Init(&ssh->exhashbase);
2194 sha_string(&ssh->exhashbase, verstring,
2195 strcspn(verstring, "\015\012"));
2196 sha_string(&ssh->exhashbase, s->vstring,
2197 strcspn(s->vstring, "\015\012"));
2200 * Initialise SSHv2 protocol.
2202 ssh->protocol = ssh2_protocol;
2203 ssh2_protocol_setup(ssh);
2204 ssh->s_rdpkt = ssh2_rdpkt;
2207 * Initialise SSHv1 protocol.
2209 ssh->protocol = ssh1_protocol;
2210 ssh1_protocol_setup(ssh);
2211 ssh->s_rdpkt = ssh1_rdpkt;
2213 logeventf(ssh, "We claim version: %.*s",
2214 strcspn(verstring, "\015\012"), verstring);
2215 sk_write(ssh->s, verstring, strlen(verstring));
2219 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2221 update_specials_menu(ssh->frontend);
2222 ssh->state = SSH_STATE_BEFORE_SIZE;
2223 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2230 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2232 crBegin(ssh->ssh_gotdata_crstate);
2235 * To begin with, feed the characters one by one to the
2236 * protocol initialisation / selection function do_ssh_init().
2237 * When that returns 0, we're done with the initial greeting
2238 * exchange and can move on to packet discipline.
2241 int ret; /* need not be kept across crReturn */
2243 crReturnV; /* more data please */
2244 ret = do_ssh_init(ssh, *data);
2252 * We emerge from that loop when the initial negotiation is
2253 * over and we have selected an s_rdpkt function. Now pass
2254 * everything to s_rdpkt, and then pass the resulting packets
2255 * to the proper protocol handler.
2260 while (datalen > 0) {
2261 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2263 ssh->protocol(ssh, NULL, 0, pktin);
2264 ssh_free_packet(pktin);
2266 if (ssh->state == SSH_STATE_CLOSED)
2274 static void ssh_do_close(Ssh ssh)
2277 struct ssh_channel *c;
2279 ssh->state = SSH_STATE_CLOSED;
2283 notify_remote_exit(ssh->frontend);
2286 * Now we must shut down any port and X forwardings going
2287 * through this connection.
2289 if (ssh->channels) {
2290 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2293 x11_close(c->u.x11.s);
2296 pfd_close(c->u.pfd.s);
2299 del234(ssh->channels, c);
2300 if (ssh->version == 2)
2301 bufchain_clear(&c->v.v2.outbuffer);
2307 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2310 Ssh ssh = (Ssh) plug;
2313 /* A socket error has occurred. */
2314 logevent(error_msg);
2315 connection_fatal(ssh->frontend, "%s", error_msg);
2317 /* Otherwise, the remote side closed the connection normally. */
2322 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2324 Ssh ssh = (Ssh) plug;
2325 ssh_gotdata(ssh, (unsigned char *)data, len);
2326 if (ssh->state == SSH_STATE_CLOSED) {
2333 static void ssh_sent(Plug plug, int bufsize)
2335 Ssh ssh = (Ssh) plug;
2337 * If the send backlog on the SSH socket itself clears, we
2338 * should unthrottle the whole world if it was throttled.
2340 if (bufsize < SSH_MAX_BACKLOG)
2341 ssh_throttle_all(ssh, 0, bufsize);
2345 * Connect to specified host and port.
2346 * Returns an error message, or NULL on success.
2347 * Also places the canonical host name into `realhost'. It must be
2348 * freed by the caller.
2350 static const char *connect_to_host(Ssh ssh, char *host, int port,
2351 char **realhost, int nodelay, int keepalive)
2353 static const struct plug_function_table fn_table = {
2363 ssh->savedhost = snewn(1 + strlen(host), char);
2364 if (!ssh->savedhost)
2365 fatalbox("Out of memory");
2366 strcpy(ssh->savedhost, host);
2369 port = 22; /* default ssh port */
2370 ssh->savedport = port;
2375 logeventf(ssh, "Looking up host \"%s\"", host);
2376 addr = name_lookup(host, port, realhost, &ssh->cfg);
2377 if ((err = sk_addr_error(addr)) != NULL) {
2387 sk_getaddr(addr, addrbuf, 100);
2388 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2390 ssh->fn = &fn_table;
2391 ssh->s = new_connection(addr, *realhost, port,
2392 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2393 if ((err = sk_socket_error(ssh->s)) != NULL) {
2395 notify_remote_exit(ssh->frontend);
2403 * Throttle or unthrottle the SSH connection.
2405 static void ssh1_throttle(Ssh ssh, int adjust)
2407 int old_count = ssh->v1_throttle_count;
2408 ssh->v1_throttle_count += adjust;
2409 assert(ssh->v1_throttle_count >= 0);
2410 if (ssh->v1_throttle_count && !old_count) {
2411 sk_set_frozen(ssh->s, 1);
2412 } else if (!ssh->v1_throttle_count && old_count) {
2413 sk_set_frozen(ssh->s, 0);
2418 * Throttle or unthrottle _all_ local data streams (for when sends
2419 * on the SSH connection itself back up).
2421 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2424 struct ssh_channel *c;
2426 if (enable == ssh->throttled_all)
2428 ssh->throttled_all = enable;
2429 ssh->overall_bufsize = bufsize;
2432 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2434 case CHAN_MAINSESSION:
2436 * This is treated separately, outside the switch.
2440 x11_override_throttle(c->u.x11.s, enable);
2443 /* Agent channels require no buffer management. */
2446 pfd_override_throttle(c->u.pfd.s, enable);
2453 * Username and password input, abstracted off into routines
2454 * reusable in several places - even between SSH1 and SSH2.
2457 /* Set up a username or password input loop on a given buffer. */
2458 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2460 ssh->userpass_input_buffer = buffer;
2461 ssh->userpass_input_buflen = buflen;
2462 ssh->userpass_input_bufpos = 0;
2463 ssh->userpass_input_echo = echo;
2467 * Process some terminal data in the course of username/password
2468 * input. Returns >0 for success (line of input returned in
2469 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2470 * for inconclusive (keep waiting for more input please).
2472 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2477 switch (c = *in++) {
2480 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2481 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2486 if (ssh->userpass_input_bufpos > 0) {
2487 if (ssh->userpass_input_echo)
2488 c_write_str(ssh, "\b \b");
2489 ssh->userpass_input_bufpos--;
2494 while (ssh->userpass_input_bufpos > 0) {
2495 if (ssh->userpass_input_echo)
2496 c_write_str(ssh, "\b \b");
2497 ssh->userpass_input_bufpos--;
2506 * This simplistic check for printability is disabled
2507 * when we're doing password input, because some people
2508 * have control characters in their passwords.o
2510 if ((!ssh->userpass_input_echo ||
2511 (c >= ' ' && c <= '~') ||
2512 ((unsigned char) c >= 160))
2513 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2514 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2515 if (ssh->userpass_input_echo)
2516 c_write(ssh, &c, 1);
2524 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2526 Ssh ssh = (Ssh) sshv;
2528 ssh->agent_response = reply;
2529 ssh->agent_response_len = replylen;
2531 if (ssh->version == 1)
2532 do_ssh1_login(ssh, NULL, -1, NULL);
2534 do_ssh2_authconn(ssh, NULL, -1, NULL);
2537 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2539 struct ssh_channel *c = (struct ssh_channel *)cv;
2541 void *sentreply = reply;
2544 /* Fake SSH_AGENT_FAILURE. */
2545 sentreply = "\0\0\0\1\5";
2548 if (ssh->version == 2) {
2549 ssh2_add_channel_data(c, sentreply, replylen);
2552 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2553 PKT_INT, c->remoteid,
2556 PKT_DATA, sentreply, replylen,
2565 * Handle the key exchange and user authentication phases.
2567 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2568 struct Packet *pktin)
2571 unsigned char cookie[8], *ptr;
2572 struct RSAKey servkey, hostkey;
2573 struct MD5Context md5c;
2574 struct do_ssh1_login_state {
2576 unsigned char *rsabuf, *keystr1, *keystr2;
2577 unsigned long supported_ciphers_mask, supported_auths_mask;
2578 int tried_publickey, tried_agent;
2579 int tis_auth_refused, ccard_auth_refused;
2580 unsigned char session_id[16];
2583 void *publickey_blob;
2584 int publickey_bloblen;
2590 unsigned char request[5], *response, *p;
2599 crState(do_ssh1_login_state);
2601 crBegin(ssh->do_ssh1_login_crstate);
2606 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2607 bombout(("Public key packet not received"));
2611 logevent("Received public keys");
2613 ptr = ssh_pkt_getdata(pktin, 8);
2615 bombout(("SSH1 public key packet stopped before random cookie"));
2618 memcpy(cookie, ptr, 8);
2620 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2621 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2622 bombout(("Failed to read SSH1 public keys from public key packet"));
2627 * Log the host key fingerprint.
2631 logevent("Host key fingerprint is:");
2632 strcpy(logmsg, " ");
2633 hostkey.comment = NULL;
2634 rsa_fingerprint(logmsg + strlen(logmsg),
2635 sizeof(logmsg) - strlen(logmsg), &hostkey);
2639 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2640 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2641 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2643 ssh->v1_local_protoflags =
2644 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2645 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2648 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2649 MD5Update(&md5c, s->keystr1, servkey.bytes);
2650 MD5Update(&md5c, cookie, 8);
2651 MD5Final(s->session_id, &md5c);
2653 for (i = 0; i < 32; i++)
2654 ssh->session_key[i] = random_byte();
2657 * Verify that the `bits' and `bytes' parameters match.
2659 if (hostkey.bits > hostkey.bytes * 8 ||
2660 servkey.bits > servkey.bytes * 8) {
2661 bombout(("SSH1 public keys were badly formatted"));
2665 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2667 s->rsabuf = snewn(s->len, unsigned char);
2669 fatalbox("Out of memory");
2672 * Verify the host key.
2676 * First format the key into a string.
2678 int len = rsastr_len(&hostkey);
2679 char fingerprint[100];
2680 char *keystr = snewn(len, char);
2682 fatalbox("Out of memory");
2683 rsastr_fmt(keystr, &hostkey);
2684 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2685 verify_ssh_host_key(ssh->frontend,
2686 ssh->savedhost, ssh->savedport, "rsa", keystr,
2691 for (i = 0; i < 32; i++) {
2692 s->rsabuf[i] = ssh->session_key[i];
2694 s->rsabuf[i] ^= s->session_id[i];
2697 if (hostkey.bytes > servkey.bytes) {
2698 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2700 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2702 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2704 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2707 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2711 logevent("Encrypted session key");
2714 int cipher_chosen = 0, warn = 0;
2715 char *cipher_string = NULL;
2717 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2718 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2719 if (next_cipher == CIPHER_WARN) {
2720 /* If/when we choose a cipher, warn about it */
2722 } else if (next_cipher == CIPHER_AES) {
2723 /* XXX Probably don't need to mention this. */
2724 logevent("AES not supported in SSH1, skipping");
2726 switch (next_cipher) {
2727 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2728 cipher_string = "3DES"; break;
2729 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2730 cipher_string = "Blowfish"; break;
2731 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2732 cipher_string = "single-DES"; break;
2734 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2738 if (!cipher_chosen) {
2739 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2740 bombout(("Server violates SSH 1 protocol by not "
2741 "supporting 3DES encryption"));
2743 /* shouldn't happen */
2744 bombout(("No supported ciphers found"));
2748 /* Warn about chosen cipher if necessary. */
2750 askalg(ssh->frontend, "cipher", cipher_string);
2753 switch (s->cipher_type) {
2754 case SSH_CIPHER_3DES:
2755 logevent("Using 3DES encryption");
2757 case SSH_CIPHER_DES:
2758 logevent("Using single-DES encryption");
2760 case SSH_CIPHER_BLOWFISH:
2761 logevent("Using Blowfish encryption");
2765 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2766 PKT_CHAR, s->cipher_type,
2767 PKT_DATA, cookie, 8,
2768 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2769 PKT_DATA, s->rsabuf, s->len,
2770 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2772 logevent("Trying to enable encryption...");
2776 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2777 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2779 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2780 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2781 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2783 ssh->crcda_ctx = crcda_make_context();
2784 logevent("Installing CRC compensation attack detector");
2786 if (servkey.modulus) {
2787 sfree(servkey.modulus);
2788 servkey.modulus = NULL;
2790 if (servkey.exponent) {
2791 sfree(servkey.exponent);
2792 servkey.exponent = NULL;
2794 if (hostkey.modulus) {
2795 sfree(hostkey.modulus);
2796 hostkey.modulus = NULL;
2798 if (hostkey.exponent) {
2799 sfree(hostkey.exponent);
2800 hostkey.exponent = NULL;
2804 if (pktin->type != SSH1_SMSG_SUCCESS) {
2805 bombout(("Encryption not successfully enabled"));
2809 logevent("Successfully started encryption");
2813 if (!*ssh->cfg.username) {
2814 if (ssh_get_line && !ssh_getline_pw_only) {
2815 if (!ssh_get_line("login as: ",
2816 s->username, sizeof(s->username), FALSE)) {
2818 * get_line failed to get a username.
2821 logevent("No username provided. Abandoning session.");
2822 ssh_closing((Plug)ssh, NULL, 0, 0);
2826 int ret; /* need not be kept over crReturn */
2827 c_write_str(ssh, "login as: ");
2830 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2832 crWaitUntil(!pktin);
2833 ret = process_userpass_input(ssh, in, inlen);
2837 c_write_str(ssh, "\r\n");
2840 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2841 s->username[sizeof(s->username)-1] = '\0';
2844 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2846 char userlog[22 + sizeof(s->username)];
2847 sprintf(userlog, "Sent username \"%s\"", s->username);
2849 if (flags & FLAG_INTERACTIVE &&
2850 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2851 strcat(userlog, "\r\n");
2852 c_write_str(ssh, userlog);
2859 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2860 /* We must not attempt PK auth. Pretend we've already tried it. */
2861 s->tried_publickey = s->tried_agent = 1;
2863 s->tried_publickey = s->tried_agent = 0;
2865 s->tis_auth_refused = s->ccard_auth_refused = 0;
2866 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2867 if (!filename_is_null(ssh->cfg.keyfile)) {
2868 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2869 &s->publickey_blob, &s->publickey_bloblen, NULL))
2870 s->publickey_blob = NULL;
2872 s->publickey_blob = NULL;
2874 while (pktin->type == SSH1_SMSG_FAILURE) {
2875 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2877 if (agent_exists() && !s->tried_agent) {
2879 * Attempt RSA authentication using Pageant.
2885 logevent("Pageant is running. Requesting keys.");
2887 /* Request the keys held by the agent. */
2888 PUT_32BIT(s->request, 1);
2889 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2890 if (!agent_query(s->request, 5, &r, &s->responselen,
2891 ssh_agent_callback, ssh)) {
2895 bombout(("Unexpected data from server while waiting"
2896 " for agent response"));
2899 } while (pktin || inlen > 0);
2900 r = ssh->agent_response;
2901 s->responselen = ssh->agent_response_len;
2903 s->response = (unsigned char *) r;
2904 if (s->response && s->responselen >= 5 &&
2905 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2906 s->p = s->response + 5;
2907 s->nkeys = GET_32BIT(s->p);
2911 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2914 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2917 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2920 if (s->publickey_blob &&
2921 !memcmp(s->p, s->publickey_blob,
2922 s->publickey_bloblen)) {
2923 logevent("This key matches configured key file");
2924 s->tried_publickey = 1;
2929 do { /* do while (0) to make breaking easy */
2930 n = ssh1_read_bignum
2931 (s->p, s->responselen-(s->p-s->response),
2936 n = ssh1_read_bignum
2937 (s->p, s->responselen-(s->p-s->response),
2942 if (s->responselen - (s->p-s->response) < 4)
2944 s->commentlen = GET_32BIT(s->p);
2946 if (s->responselen - (s->p-s->response) <
2949 s->commentp = (char *)s->p;
2950 s->p += s->commentlen;
2954 logevent("Pageant key list packet was truncated");
2958 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2959 PKT_BIGNUM, s->key.modulus, PKT_END);
2961 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2962 logevent("Key refused");
2965 logevent("Received RSA challenge");
2966 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
2967 bombout(("Server's RSA challenge was badly formatted"));
2972 char *agentreq, *q, *ret;
2975 len = 1 + 4; /* message type, bit count */
2976 len += ssh1_bignum_length(s->key.exponent);
2977 len += ssh1_bignum_length(s->key.modulus);
2978 len += ssh1_bignum_length(s->challenge);
2979 len += 16; /* session id */
2980 len += 4; /* response format */
2981 agentreq = snewn(4 + len, char);
2982 PUT_32BIT(agentreq, len);
2984 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2985 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2987 q += ssh1_write_bignum(q, s->key.exponent);
2988 q += ssh1_write_bignum(q, s->key.modulus);
2989 q += ssh1_write_bignum(q, s->challenge);
2990 memcpy(q, s->session_id, 16);
2992 PUT_32BIT(q, 1); /* response format */
2993 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2994 ssh_agent_callback, ssh)) {
2999 bombout(("Unexpected data from server"
3000 " while waiting for agent"
3004 } while (pktin || inlen > 0);
3005 vret = ssh->agent_response;
3006 retlen = ssh->agent_response_len;
3011 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3012 logevent("Sending Pageant's response");
3013 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3014 PKT_DATA, ret + 5, 16,
3018 if (pktin->type == SSH1_SMSG_SUCCESS) {
3020 ("Pageant's response accepted");
3021 if (flags & FLAG_VERBOSE) {
3022 c_write_str(ssh, "Authenticated using"
3024 c_write(ssh, s->commentp,
3026 c_write_str(ssh, "\" from agent\r\n");
3031 ("Pageant's response not accepted");
3034 ("Pageant failed to answer challenge");
3038 logevent("No reply received from Pageant");
3041 freebn(s->key.exponent);
3042 freebn(s->key.modulus);
3043 freebn(s->challenge);
3052 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3053 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3055 if (ssh->cfg.try_tis_auth &&
3056 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3057 !s->tis_auth_refused) {
3058 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3059 logevent("Requested TIS authentication");
3060 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3062 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3063 logevent("TIS authentication declined");
3064 if (flags & FLAG_INTERACTIVE)
3065 c_write_str(ssh, "TIS authentication refused.\r\n");
3066 s->tis_auth_refused = 1;
3072 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3074 bombout(("TIS challenge packet was badly formed"));
3077 logevent("Received TIS challenge");
3078 if (challengelen > sizeof(s->prompt) - 1)
3079 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3080 memcpy(s->prompt, challenge, challengelen);
3081 /* Prompt heuristic comes from OpenSSH */
3082 strncpy(s->prompt + challengelen,
3083 memchr(s->prompt, '\n', challengelen) ?
3084 "": "\r\nResponse: ",
3085 (sizeof s->prompt) - challengelen);
3086 s->prompt[(sizeof s->prompt) - 1] = '\0';
3089 if (ssh->cfg.try_tis_auth &&
3090 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3091 !s->ccard_auth_refused) {
3092 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3093 logevent("Requested CryptoCard authentication");
3094 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3096 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3097 logevent("CryptoCard authentication declined");
3098 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3099 s->ccard_auth_refused = 1;
3105 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3107 bombout(("CryptoCard challenge packet was badly formed"));
3110 logevent("Received CryptoCard challenge");
3111 if (challengelen > sizeof(s->prompt) - 1)
3112 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3113 memcpy(s->prompt, challenge, challengelen);
3114 strncpy(s->prompt + challengelen,
3115 memchr(s->prompt, '\n', challengelen) ?
3116 "" : "\r\nResponse: ",
3117 sizeof(s->prompt) - challengelen);
3118 s->prompt[sizeof(s->prompt) - 1] = '\0';
3121 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3122 sprintf(s->prompt, "%.90s@%.90s's password: ",
3123 s->username, ssh->savedhost);
3125 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3126 char *comment = NULL;
3129 if (flags & FLAG_VERBOSE)
3130 c_write_str(ssh, "Trying public key authentication.\r\n");
3131 logeventf(ssh, "Trying public key \"%s\"",
3132 filename_to_str(&ssh->cfg.keyfile));
3133 type = key_type(&ssh->cfg.keyfile);
3134 if (type != SSH_KEYTYPE_SSH1) {
3135 sprintf(msgbuf, "Key is of wrong type (%s)",
3136 key_type_to_str(type));
3138 c_write_str(ssh, msgbuf);
3139 c_write_str(ssh, "\r\n");
3140 s->tried_publickey = 1;
3143 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3144 if (flags & FLAG_VERBOSE)
3145 c_write_str(ssh, "No passphrase required.\r\n");
3148 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3153 * Show password prompt, having first obtained it via a TIS
3154 * or CryptoCard exchange if we're doing TIS or CryptoCard
3158 if (!ssh_get_line(s->prompt, s->password,
3159 sizeof(s->password), TRUE)) {
3161 * get_line failed to get a password (for example
3162 * because one was supplied on the command line
3163 * which has already failed to work). Terminate.
3165 send_packet(ssh, SSH1_MSG_DISCONNECT,
3166 PKT_STR, "No more passwords available to try",
3168 logevent("Unable to authenticate");
3169 connection_fatal(ssh->frontend, "Unable to authenticate");
3170 ssh_closing((Plug)ssh, NULL, 0, 0);
3174 /* Prompt may have come from server. We've munged it a bit, so
3175 * we know it to be zero-terminated at least once. */
3176 int ret; /* need not be saved over crReturn */
3177 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3180 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3182 crWaitUntil(!pktin);
3183 ret = process_userpass_input(ssh, in, inlen);
3187 c_write_str(ssh, "\r\n");
3191 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3193 * Try public key authentication with the specified
3196 s->tried_publickey = 1;
3199 const char *error = NULL;
3200 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3203 c_write_str(ssh, "Couldn't load private key from ");
3204 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3205 c_write_str(ssh, " (");
3206 c_write_str(ssh, error);
3207 c_write_str(ssh, ").\r\n");
3208 continue; /* go and try password */
3211 c_write_str(ssh, "Wrong passphrase.\r\n");
3212 s->tried_publickey = 0;
3213 continue; /* try again */
3218 * Send a public key attempt.
3220 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3221 PKT_BIGNUM, s->key.modulus, PKT_END);
3224 if (pktin->type == SSH1_SMSG_FAILURE) {
3225 c_write_str(ssh, "Server refused our public key.\r\n");
3226 continue; /* go and try password */
3228 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3229 bombout(("Bizarre response to offer of public key"));
3235 unsigned char buffer[32];
3236 Bignum challenge, response;
3238 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3239 bombout(("Server's RSA challenge was badly formatted"));
3242 response = rsadecrypt(challenge, &s->key);
3243 freebn(s->key.private_exponent);/* burn the evidence */
3245 for (i = 0; i < 32; i++) {
3246 buffer[i] = bignum_byte(response, 31 - i);
3250 MD5Update(&md5c, buffer, 32);
3251 MD5Update(&md5c, s->session_id, 16);
3252 MD5Final(buffer, &md5c);
3254 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3255 PKT_DATA, buffer, 16, PKT_END);
3262 if (pktin->type == SSH1_SMSG_FAILURE) {
3263 if (flags & FLAG_VERBOSE)
3264 c_write_str(ssh, "Failed to authenticate with"
3265 " our public key.\r\n");
3266 continue; /* go and try password */
3267 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3268 bombout(("Bizarre response to RSA authentication response"));
3272 break; /* we're through! */
3274 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3276 * Defence against traffic analysis: we send a
3277 * whole bunch of packets containing strings of
3278 * different lengths. One of these strings is the
3279 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3280 * The others are all random data in
3281 * SSH1_MSG_IGNORE packets. This way a passive
3282 * listener can't tell which is the password, and
3283 * hence can't deduce the password length.
3285 * Anybody with a password length greater than 16
3286 * bytes is going to have enough entropy in their
3287 * password that a listener won't find it _that_
3288 * much help to know how long it is. So what we'll
3291 * - if password length < 16, we send 15 packets
3292 * containing string lengths 1 through 15
3294 * - otherwise, we let N be the nearest multiple
3295 * of 8 below the password length, and send 8
3296 * packets containing string lengths N through
3297 * N+7. This won't obscure the order of
3298 * magnitude of the password length, but it will
3299 * introduce a bit of extra uncertainty.
3301 * A few servers (the old 1.2.18 through 1.2.22)
3302 * can't deal with SSH1_MSG_IGNORE. For these
3303 * servers, we need an alternative defence. We make
3304 * use of the fact that the password is interpreted
3305 * as a C string: so we can append a NUL, then some
3308 * One server (a Cisco one) can deal with neither
3309 * SSH1_MSG_IGNORE _nor_ a padded password string.
3310 * For this server we are left with no defences
3311 * against password length sniffing.
3313 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3315 * The server can deal with SSH1_MSG_IGNORE, so
3316 * we can use the primary defence.
3318 int bottom, top, pwlen, i;
3321 pwlen = strlen(s->password);
3323 bottom = 0; /* zero length passwords are OK! :-) */
3326 bottom = pwlen & ~7;
3330 assert(pwlen >= bottom && pwlen <= top);
3332 randomstr = snewn(top + 1, char);
3334 for (i = bottom; i <= top; i++) {
3336 defer_packet(ssh, s->pwpkt_type,
3337 PKTT_PASSWORD, PKT_STR, s->password,
3338 PKTT_OTHER, PKT_END);
3340 for (j = 0; j < i; j++) {
3342 randomstr[j] = random_byte();
3343 } while (randomstr[j] == '\0');
3345 randomstr[i] = '\0';
3346 defer_packet(ssh, SSH1_MSG_IGNORE,
3347 PKT_STR, randomstr, PKT_END);
3350 logevent("Sending password with camouflage packets");
3351 ssh_pkt_defersend(ssh);
3354 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3356 * The server can't deal with SSH1_MSG_IGNORE
3357 * but can deal with padded passwords, so we
3358 * can use the secondary defence.
3364 len = strlen(s->password);
3365 if (len < sizeof(string)) {
3367 strcpy(string, s->password);
3368 len++; /* cover the zero byte */
3369 while (len < sizeof(string)) {
3370 string[len++] = (char) random_byte();
3375 logevent("Sending length-padded password");
3376 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3377 PKT_INT, len, PKT_DATA, ss, len,
3378 PKTT_OTHER, PKT_END);
3381 * The server has _both_
3382 * BUG_CHOKES_ON_SSH1_IGNORE and
3383 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3384 * therefore nothing we can do.
3387 len = strlen(s->password);
3388 logevent("Sending unpadded password");
3389 send_packet(ssh, s->pwpkt_type,
3390 PKTT_PASSWORD, PKT_INT, len,
3391 PKT_DATA, s->password, len,
3392 PKTT_OTHER, PKT_END);
3395 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3396 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3399 logevent("Sent password");
3400 memset(s->password, 0, strlen(s->password));
3402 if (pktin->type == SSH1_SMSG_FAILURE) {
3403 if (flags & FLAG_VERBOSE)
3404 c_write_str(ssh, "Access denied\r\n");
3405 logevent("Authentication refused");
3406 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3407 bombout(("Strange packet received, type %d", pktin->type));
3412 logevent("Authentication successful");
3417 void sshfwd_close(struct ssh_channel *c)
3421 if (ssh->state != SSH_STATE_SESSION) {
3422 assert(ssh->state == SSH_STATE_CLOSED);
3426 if (c && !c->closes) {
3428 * If the channel's remoteid is -1, we have sent
3429 * CHANNEL_OPEN for this channel, but it hasn't even been
3430 * acknowledged by the server. So we must set a close flag
3431 * on it now, and then when the server acks the channel
3432 * open, we can close it then.
3434 if (((int)c->remoteid) != -1) {
3435 if (ssh->version == 1) {
3436 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3439 struct Packet *pktout;
3440 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3441 ssh2_pkt_adduint32(pktout, c->remoteid);
3442 ssh2_pkt_send(ssh, pktout);
3445 c->closes = 1; /* sent MSG_CLOSE */
3446 if (c->type == CHAN_X11) {
3448 logevent("Forwarded X11 connection terminated");
3449 } else if (c->type == CHAN_SOCKDATA ||
3450 c->type == CHAN_SOCKDATA_DORMANT) {
3452 logevent("Forwarded port closed");
3457 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3461 if (ssh->state != SSH_STATE_SESSION) {
3462 assert(ssh->state == SSH_STATE_CLOSED);
3466 if (ssh->version == 1) {
3467 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3468 PKT_INT, c->remoteid,
3470 PKT_INT, len, PKT_DATA, buf, len,
3471 PKTT_OTHER, PKT_END);
3473 * In SSH1 we can return 0 here - implying that forwarded
3474 * connections are never individually throttled - because
3475 * the only circumstance that can cause throttling will be
3476 * the whole SSH connection backing up, in which case
3477 * _everything_ will be throttled as a whole.
3481 ssh2_add_channel_data(c, buf, len);
3482 return ssh2_try_send(c);
3486 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3490 if (ssh->state != SSH_STATE_SESSION) {
3491 assert(ssh->state == SSH_STATE_CLOSED);
3495 if (ssh->version == 1) {
3496 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3497 c->v.v1.throttling = 0;
3498 ssh1_throttle(ssh, -1);
3501 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3505 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3508 int stringlen, bufsize;
3510 ssh_pkt_getstring(pktin, &string, &stringlen);
3511 if (string == NULL) {
3512 bombout(("Incoming terminal data packet was badly formed"));
3516 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3518 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3519 ssh->v1_stdout_throttling = 1;
3520 ssh1_throttle(ssh, +1);
3524 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3526 /* Remote side is trying to open a channel to talk to our
3527 * X-Server. Give them back a local channel number. */
3528 struct ssh_channel *c;
3529 int remoteid = ssh_pkt_getuint32(pktin);
3531 logevent("Received X11 connect request");
3532 /* Refuse if X11 forwarding is disabled. */
3533 if (!ssh->X11_fwd_enabled) {
3534 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3535 PKT_INT, remoteid, PKT_END);
3536 logevent("Rejected X11 connect request");
3538 c = snew(struct ssh_channel);
3541 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3542 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3543 logevent("Opening X11 forward connection failed");
3545 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3546 PKT_INT, remoteid, PKT_END);
3549 ("Opening X11 forward connection succeeded");
3550 c->remoteid = remoteid;
3551 c->localid = alloc_channel_id(ssh);
3553 c->v.v1.throttling = 0;
3554 c->type = CHAN_X11; /* identify channel type */
3555 add234(ssh->channels, c);
3556 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3557 PKT_INT, c->remoteid, PKT_INT,
3558 c->localid, PKT_END);
3559 logevent("Opened X11 forward channel");
3564 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3566 /* Remote side is trying to open a channel to talk to our
3567 * agent. Give them back a local channel number. */
3568 struct ssh_channel *c;
3569 int remoteid = ssh_pkt_getuint32(pktin);
3571 /* Refuse if agent forwarding is disabled. */
3572 if (!ssh->agentfwd_enabled) {
3573 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3574 PKT_INT, remoteid, PKT_END);
3576 c = snew(struct ssh_channel);
3578 c->remoteid = remoteid;
3579 c->localid = alloc_channel_id(ssh);
3581 c->v.v1.throttling = 0;
3582 c->type = CHAN_AGENT; /* identify channel type */
3583 c->u.a.lensofar = 0;
3584 add234(ssh->channels, c);
3585 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3586 PKT_INT, c->remoteid, PKT_INT, c->localid,
3591 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3593 /* Remote side is trying to open a channel to talk to a
3594 * forwarded port. Give them back a local channel number. */
3595 struct ssh_channel *c;
3596 struct ssh_rportfwd pf;
3599 char *host, buf[1024];
3601 c = snew(struct ssh_channel);
3604 remoteid = ssh_pkt_getuint32(pktin);
3605 ssh_pkt_getstring(pktin, &host, &hostsize);
3606 port = ssh_pkt_getuint32(pktin);
3608 if (hostsize >= lenof(pf.dhost))
3609 hostsize = lenof(pf.dhost)-1;
3610 memcpy(pf.dhost, host, hostsize);
3611 pf.dhost[hostsize] = '\0';
3614 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3615 sprintf(buf, "Rejected remote port open request for %s:%d",
3618 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3619 PKT_INT, remoteid, PKT_END);
3621 sprintf(buf, "Received remote port open request for %s:%d",
3624 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3628 sprintf(buf, "Port open failed: %s", e);
3631 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3632 PKT_INT, remoteid, PKT_END);
3634 c->remoteid = remoteid;
3635 c->localid = alloc_channel_id(ssh);
3637 c->v.v1.throttling = 0;
3638 c->type = CHAN_SOCKDATA; /* identify channel type */
3639 add234(ssh->channels, c);
3640 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3641 PKT_INT, c->remoteid, PKT_INT,
3642 c->localid, PKT_END);
3643 logevent("Forwarded port opened successfully");
3648 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3650 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3651 unsigned int localid = ssh_pkt_getuint32(pktin);
3652 struct ssh_channel *c;
3654 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3655 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3656 c->remoteid = localid;
3657 c->type = CHAN_SOCKDATA;
3658 c->v.v1.throttling = 0;
3659 pfd_confirm(c->u.pfd.s);
3662 if (c && c->closes) {
3664 * We have a pending close on this channel,
3665 * which we decided on before the server acked
3666 * the channel open. So now we know the
3667 * remoteid, we can close it again.
3669 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3670 PKT_INT, c->remoteid, PKT_END);
3674 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3676 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3677 struct ssh_channel *c;
3679 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3680 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3681 logevent("Forwarded connection refused by server");
3682 pfd_close(c->u.pfd.s);
3683 del234(ssh->channels, c);
3688 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3690 /* Remote side closes a channel. */
3691 unsigned i = ssh_pkt_getuint32(pktin);
3692 struct ssh_channel *c;
3693 c = find234(ssh->channels, &i, ssh_channelfind);
3694 if (c && ((int)c->remoteid) != -1) {
3697 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3699 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3700 logevent("Forwarded X11 connection terminated");
3701 assert(c->u.x11.s != NULL);
3702 x11_close(c->u.x11.s);
3705 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3706 logevent("Forwarded port closed");
3707 assert(c->u.pfd.s != NULL);
3708 pfd_close(c->u.pfd.s);
3712 c->closes |= (closetype << 2); /* seen this message */
3713 if (!(c->closes & closetype)) {
3714 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3716 c->closes |= closetype; /* sent it too */
3719 if (c->closes == 15) {
3720 del234(ssh->channels, c);
3724 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3725 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3726 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3731 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3733 /* Data sent down one of our channels. */
3734 int i = ssh_pkt_getuint32(pktin);
3737 struct ssh_channel *c;
3739 ssh_pkt_getstring(pktin, &p, &len);
3741 c = find234(ssh->channels, &i, ssh_channelfind);
3746 bufsize = x11_send(c->u.x11.s, p, len);
3749 bufsize = pfd_send(c->u.pfd.s, p, len);
3752 /* Data for an agent message. Buffer it. */
3754 if (c->u.a.lensofar < 4) {
3755 int l = min(4 - c->u.a.lensofar, len);
3756 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3760 c->u.a.lensofar += l;
3762 if (c->u.a.lensofar == 4) {
3764 4 + GET_32BIT(c->u.a.msglen);
3765 c->u.a.message = snewn(c->u.a.totallen,
3767 memcpy(c->u.a.message, c->u.a.msglen, 4);
3769 if (c->u.a.lensofar >= 4 && len > 0) {
3771 min(c->u.a.totallen - c->u.a.lensofar,
3773 memcpy(c->u.a.message + c->u.a.lensofar, p,
3777 c->u.a.lensofar += l;
3779 if (c->u.a.lensofar == c->u.a.totallen) {
3782 if (agent_query(c->u.a.message,
3785 ssh_agentf_callback, c))
3786 ssh_agentf_callback(c, reply, replylen);
3787 sfree(c->u.a.message);
3788 c->u.a.lensofar = 0;
3791 bufsize = 0; /* agent channels never back up */
3794 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3795 c->v.v1.throttling = 1;
3796 ssh1_throttle(ssh, +1);
3801 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3804 ssh->exitcode = ssh_pkt_getuint32(pktin);
3805 sprintf(buf, "Server sent command exit status %d",
3808 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3810 * In case `helpful' firewalls or proxies tack
3811 * extra human-readable text on the end of the
3812 * session which we might mistake for another
3813 * encrypted packet, we close the session once
3814 * we've sent EXIT_CONFIRMATION.
3816 ssh_closing((Plug)ssh, NULL, 0, 0);
3819 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3820 struct Packet *pktin)
3822 crBegin(ssh->do_ssh1_connection_crstate);
3824 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3825 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3826 ssh1_smsg_stdout_stderr_data;
3828 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3829 ssh1_msg_channel_open_confirmation;
3830 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3831 ssh1_msg_channel_open_failure;
3832 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3833 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3834 ssh1_msg_channel_close;
3835 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3836 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3838 if (ssh->cfg.agentfwd && agent_exists()) {
3839 logevent("Requesting agent forwarding");
3840 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3844 if (pktin->type != SSH1_SMSG_SUCCESS
3845 && pktin->type != SSH1_SMSG_FAILURE) {
3846 bombout(("Protocol confusion"));
3848 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3849 logevent("Agent forwarding refused");
3851 logevent("Agent forwarding enabled");
3852 ssh->agentfwd_enabled = TRUE;
3853 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
3857 if (ssh->cfg.x11_forward) {
3858 char proto[20], data[64];
3859 logevent("Requesting X11 forwarding");
3860 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3861 data, sizeof(data), ssh->cfg.x11_auth);
3862 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3863 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3864 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3865 PKT_STR, proto, PKT_STR, data,
3866 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3869 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3870 PKT_STR, proto, PKT_STR, data, PKT_END);
3875 if (pktin->type != SSH1_SMSG_SUCCESS
3876 && pktin->type != SSH1_SMSG_FAILURE) {
3877 bombout(("Protocol confusion"));
3879 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3880 logevent("X11 forwarding refused");
3882 logevent("X11 forwarding enabled");
3883 ssh->X11_fwd_enabled = TRUE;
3884 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
3891 int sport,dport,sserv,dserv;
3892 char sports[256], dports[256], saddr[256], host[256];
3894 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3895 /* Add port forwardings. */
3896 ssh->portfwd_strptr = ssh->cfg.portfwd;
3897 while (*ssh->portfwd_strptr) {
3898 type = *ssh->portfwd_strptr++;
3901 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3902 if (*ssh->portfwd_strptr == ':') {
3904 * We've seen a colon in the middle of the
3905 * source port number. This means that
3906 * everything we've seen until now is the
3907 * source _address_, so we'll move it into
3908 * saddr and start sports from the beginning
3911 ssh->portfwd_strptr++;
3913 strcpy(saddr, sports);
3916 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3920 if (*ssh->portfwd_strptr == '\t')
3921 ssh->portfwd_strptr++;
3923 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3924 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3927 if (*ssh->portfwd_strptr == ':')
3928 ssh->portfwd_strptr++;
3930 while (*ssh->portfwd_strptr) {
3931 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3934 ssh->portfwd_strptr++;
3935 dport = atoi(dports);
3939 dport = net_service_lookup(dports);
3941 logeventf(ssh, "Service lookup failed for"
3942 " destination port \"%s\"", dports);
3946 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3948 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3950 sport = atoi(sports);
3954 sport = net_service_lookup(sports);
3956 logeventf(ssh, "Service lookup failed for source"
3957 " port \"%s\"", sports);
3960 if (sport && dport) {
3961 /* Set up a description of the source port. */
3962 static char *sportdesc;
3963 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3964 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3965 (int)(*saddr?1:0), ":",
3966 (int)(sserv ? strlen(sports) : 0), sports,
3967 sserv, "(", sport, sserv, ")");
3969 /* Verbose description of the destination port */
3970 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3972 (int)(dserv ? strlen(dports) : 0), dports,
3973 dserv, "(", dport, dserv, ")");
3974 const char *err = pfd_addforward(host, dport,
3975 *saddr ? saddr : NULL,
3976 sport, ssh, &ssh->cfg);
3978 logeventf(ssh, "Local port %s forward to %s"
3979 " failed: %s", sportdesc, dportdesc, err);
3981 logeventf(ssh, "Local port %s forwarding to %s",
3982 sportdesc, dportdesc);
3985 } else if (type == 'D') {
3986 const char *err = pfd_addforward(NULL, -1,
3987 *saddr ? saddr : NULL,
3988 sport, ssh, &ssh->cfg);
3990 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3991 " setup failed: %s", sportdesc, err);
3993 logeventf(ssh, "Local port %s doing SOCKS"
3994 " dynamic forwarding", sportdesc);
3997 struct ssh_rportfwd *pf;
3998 pf = snew(struct ssh_rportfwd);
3999 strcpy(pf->dhost, host);
4003 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
4006 if (add234(ssh->rportfwds, pf) != pf) {
4008 "Duplicate remote port forwarding to %s:%d",
4012 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
4013 " forward to %s:%.*s%.*s%d%.*s",
4014 (int)(sserv ? strlen(sports) : 0), sports,
4015 sserv, "(", sport, sserv, ")",
4017 (int)(dserv ? strlen(dports) : 0), dports,
4018 dserv, "(", dport, dserv, ")");
4019 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4027 if (pktin->type != SSH1_SMSG_SUCCESS
4028 && pktin->type != SSH1_SMSG_FAILURE) {
4029 bombout(("Protocol confusion"));
4031 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4032 c_write_str(ssh, "Server refused port"
4034 logevent("Server refused this port forwarding");
4036 logevent("Remote port forwarding enabled");
4037 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4047 if (!ssh->cfg.nopty) {
4048 /* Unpick the terminal-speed string. */
4049 /* XXX perhaps we should allow no speeds to be sent. */
4050 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4051 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4052 /* Send the pty request. */
4053 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4054 PKT_STR, ssh->cfg.termtype,
4055 PKT_INT, ssh->term_height,
4056 PKT_INT, ssh->term_width,
4057 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4058 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4059 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4060 PKT_CHAR, 0, PKT_END);
4061 ssh->state = SSH_STATE_INTERMED;
4065 if (pktin->type != SSH1_SMSG_SUCCESS
4066 && pktin->type != SSH1_SMSG_FAILURE) {
4067 bombout(("Protocol confusion"));
4069 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4070 c_write_str(ssh, "Server refused to allocate pty\r\n");
4071 ssh->editing = ssh->echoing = 1;
4073 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4074 ssh->ospeed, ssh->ispeed);
4076 ssh->editing = ssh->echoing = 1;
4079 if (ssh->cfg.compression) {
4080 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4084 if (pktin->type != SSH1_SMSG_SUCCESS
4085 && pktin->type != SSH1_SMSG_FAILURE) {
4086 bombout(("Protocol confusion"));
4088 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4089 c_write_str(ssh, "Server refused to compress\r\n");
4091 logevent("Started compression");
4092 ssh->v1_compressing = TRUE;
4093 ssh->cs_comp_ctx = zlib_compress_init();
4094 logevent("Initialised zlib (RFC1950) compression");
4095 ssh->sc_comp_ctx = zlib_decompress_init();
4096 logevent("Initialised zlib (RFC1950) decompression");
4100 * Start the shell or command.
4102 * Special case: if the first-choice command is an SSH2
4103 * subsystem (hence not usable here) and the second choice
4104 * exists, we fall straight back to that.
4107 char *cmd = ssh->cfg.remote_cmd_ptr;
4109 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4110 cmd = ssh->cfg.remote_cmd_ptr2;
4111 ssh->fallback_cmd = TRUE;
4114 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4116 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4117 logevent("Started session");
4120 ssh->state = SSH_STATE_SESSION;
4121 if (ssh->size_needed)
4122 ssh_size(ssh, ssh->term_width, ssh->term_height);
4123 if (ssh->eof_needed)
4124 ssh_special(ssh, TS_EOF);
4127 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4129 ssh->channels = newtree234(ssh_channelcmp);
4133 * By this point, most incoming packets are already being
4134 * handled by the dispatch table, and we need only pay
4135 * attention to the unusual ones.
4140 if (pktin->type == SSH1_SMSG_SUCCESS) {
4141 /* may be from EXEC_SHELL on some servers */
4142 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4143 /* may be from EXEC_SHELL on some servers
4144 * if no pty is available or in other odd cases. Ignore */
4146 bombout(("Strange packet received: type %d", pktin->type));
4151 int len = min(inlen, 512);
4152 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4153 PKT_INT, len, PKT_DATA, in, len,
4154 PKTT_OTHER, PKT_END);
4165 * Handle the top-level SSH2 protocol.
4167 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4172 ssh_pkt_getstring(pktin, &msg, &msglen);
4173 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4178 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4180 /* log reason code in disconnect message */
4184 ssh_pkt_getstring(pktin, &msg, &msglen);
4185 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4188 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4190 /* Do nothing, because we're ignoring it! Duhh. */
4193 static void ssh1_protocol_setup(Ssh ssh)
4198 * Most messages are handled by the coroutines.
4200 for (i = 0; i < 256; i++)
4201 ssh->packet_dispatch[i] = NULL;
4204 * These special message types we install handlers for.
4206 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4207 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4208 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4211 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4212 struct Packet *pktin)
4214 if (ssh->state == SSH_STATE_CLOSED)
4217 if (pktin && ssh->packet_dispatch[pktin->type]) {
4218 ssh->packet_dispatch[pktin->type](ssh, pktin);
4222 if (!ssh->protocol_initial_phase_done) {
4223 if (do_ssh1_login(ssh, in, inlen, pktin))
4224 ssh->protocol_initial_phase_done = TRUE;
4229 do_ssh1_connection(ssh, in, inlen, pktin);
4233 * Utility routine for decoding comma-separated strings in KEXINIT.
4235 static int in_commasep_string(char *needle, char *haystack, int haylen)
4238 if (!needle || !haystack) /* protect against null pointers */
4240 needlen = strlen(needle);
4243 * Is it at the start of the string?
4245 if (haylen >= needlen && /* haystack is long enough */
4246 !memcmp(needle, haystack, needlen) && /* initial match */
4247 (haylen == needlen || haystack[needlen] == ',')
4248 /* either , or EOS follows */
4252 * If not, search for the next comma and resume after that.
4253 * If no comma found, terminate.
4255 while (haylen > 0 && *haystack != ',')
4256 haylen--, haystack++;
4259 haylen--, haystack++; /* skip over comma itself */
4264 * SSH2 key creation method.
4266 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4267 unsigned char *sessid, char chr,
4268 unsigned char *keyspace)
4271 /* First 20 bytes. */
4273 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4275 SHA_Bytes(&s, H, 20);
4276 SHA_Bytes(&s, &chr, 1);
4277 SHA_Bytes(&s, sessid, 20);
4278 SHA_Final(&s, keyspace);
4279 /* Next 20 bytes. */
4281 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4283 SHA_Bytes(&s, H, 20);
4284 SHA_Bytes(&s, keyspace, 20);
4285 SHA_Final(&s, keyspace + 20);
4289 * Handle the SSH2 transport layer.
4291 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4292 struct Packet *pktin)
4294 struct do_ssh2_transport_state {
4295 int nbits, pbits, warn;
4296 Bignum p, g, e, f, K;
4297 int kex_init_value, kex_reply_value;
4298 const struct ssh_mac **maclist;
4300 const struct ssh2_cipher *cscipher_tobe;
4301 const struct ssh2_cipher *sccipher_tobe;
4302 const struct ssh_mac *csmac_tobe;
4303 const struct ssh_mac *scmac_tobe;
4304 const struct ssh_compress *cscomp_tobe;
4305 const struct ssh_compress *sccomp_tobe;
4306 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4307 int hostkeylen, siglen;
4308 void *hkey; /* actual host key */
4309 unsigned char exchange_hash[20];
4310 int n_preferred_kex;
4311 const struct ssh_kex *preferred_kex[KEX_MAX];
4312 int n_preferred_ciphers;
4313 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4314 const struct ssh_compress *preferred_comp;
4316 struct Packet *pktout;
4318 crState(do_ssh2_transport_state);
4320 crBegin(ssh->do_ssh2_transport_crstate);
4322 s->cscipher_tobe = s->sccipher_tobe = NULL;
4323 s->csmac_tobe = s->scmac_tobe = NULL;
4324 s->cscomp_tobe = s->sccomp_tobe = NULL;
4331 * Set up the preferred key exchange. (NULL => warn below here)
4333 s->n_preferred_kex = 0;
4334 for (i = 0; i < KEX_MAX; i++) {
4335 switch (ssh->cfg.ssh_kexlist[i]) {
4337 s->preferred_kex[s->n_preferred_kex++] =
4338 &ssh_diffiehellman_gex;
4341 s->preferred_kex[s->n_preferred_kex++] =
4342 &ssh_diffiehellman_group14;
4345 s->preferred_kex[s->n_preferred_kex++] =
4346 &ssh_diffiehellman_group1;
4349 /* Flag for later. Don't bother if it's the last in
4351 if (i < KEX_MAX - 1) {
4352 s->preferred_kex[s->n_preferred_kex++] = NULL;
4362 * Set up the preferred ciphers. (NULL => warn below here)
4364 s->n_preferred_ciphers = 0;
4365 for (i = 0; i < CIPHER_MAX; i++) {
4366 switch (ssh->cfg.ssh_cipherlist[i]) {
4367 case CIPHER_BLOWFISH:
4368 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4371 if (ssh->cfg.ssh2_des_cbc) {
4372 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4376 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4379 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4382 /* Flag for later. Don't bother if it's the last in
4384 if (i < CIPHER_MAX - 1) {
4385 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4393 * Set up preferred compression.
4395 if (ssh->cfg.compression)
4396 s->preferred_comp = &ssh_zlib;
4398 s->preferred_comp = &ssh_comp_none;
4401 * Be prepared to work around the buggy MAC problem.
4403 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4404 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4406 s->maclist = macs, s->nmacs = lenof(macs);
4410 int i, j, commalist_started;
4413 * Enable queueing of outgoing auth- or connection-layer
4414 * packets while we are in the middle of a key exchange.
4416 ssh->queueing = TRUE;
4419 * Flag that KEX is in progress.
4421 ssh->kex_in_progress = TRUE;
4424 * Construct and send our key exchange packet.
4426 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4427 for (i = 0; i < 16; i++)
4428 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4429 /* List key exchange algorithms. */
4430 ssh2_pkt_addstring_start(s->pktout);
4431 commalist_started = 0;
4432 for (i = 0; i < s->n_preferred_kex; i++) {
4433 const struct ssh_kex *k = s->preferred_kex[i];
4434 if (!k) continue; /* warning flag */
4435 if (commalist_started)
4436 ssh2_pkt_addstring_str(s->pktout, ",");
4437 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4438 commalist_started = 1;
4440 /* List server host key algorithms. */
4441 ssh2_pkt_addstring_start(s->pktout);
4442 for (i = 0; i < lenof(hostkey_algs); i++) {
4443 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4444 if (i < lenof(hostkey_algs) - 1)
4445 ssh2_pkt_addstring_str(s->pktout, ",");
4447 /* List client->server encryption algorithms. */
4448 ssh2_pkt_addstring_start(s->pktout);
4449 commalist_started = 0;
4450 for (i = 0; i < s->n_preferred_ciphers; i++) {
4451 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4452 if (!c) continue; /* warning flag */
4453 for (j = 0; j < c->nciphers; j++) {
4454 if (commalist_started)
4455 ssh2_pkt_addstring_str(s->pktout, ",");
4456 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4457 commalist_started = 1;
4460 /* List server->client encryption algorithms. */
4461 ssh2_pkt_addstring_start(s->pktout);
4462 commalist_started = 0;
4463 for (i = 0; i < s->n_preferred_ciphers; i++) {
4464 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4465 if (!c) continue; /* warning flag */
4466 for (j = 0; j < c->nciphers; j++) {
4467 if (commalist_started)
4468 ssh2_pkt_addstring_str(s->pktout, ",");
4469 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4470 commalist_started = 1;
4473 /* List client->server MAC algorithms. */
4474 ssh2_pkt_addstring_start(s->pktout);
4475 for (i = 0; i < s->nmacs; i++) {
4476 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4477 if (i < s->nmacs - 1)
4478 ssh2_pkt_addstring_str(s->pktout, ",");
4480 /* List server->client MAC algorithms. */
4481 ssh2_pkt_addstring_start(s->pktout);
4482 for (i = 0; i < s->nmacs; i++) {
4483 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4484 if (i < s->nmacs - 1)
4485 ssh2_pkt_addstring_str(s->pktout, ",");
4487 /* List client->server compression algorithms. */
4488 ssh2_pkt_addstring_start(s->pktout);
4489 assert(lenof(compressions) > 1);
4490 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4491 for (i = 0; i < lenof(compressions); i++) {
4492 const struct ssh_compress *c = compressions[i];
4493 if (c != s->preferred_comp) {
4494 ssh2_pkt_addstring_str(s->pktout, ",");
4495 ssh2_pkt_addstring_str(s->pktout, c->name);
4498 /* List server->client compression algorithms. */
4499 ssh2_pkt_addstring_start(s->pktout);
4500 assert(lenof(compressions) > 1);
4501 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4502 for (i = 0; i < lenof(compressions); i++) {
4503 const struct ssh_compress *c = compressions[i];
4504 if (c != s->preferred_comp) {
4505 ssh2_pkt_addstring_str(s->pktout, ",");
4506 ssh2_pkt_addstring_str(s->pktout, c->name);
4509 /* List client->server languages. Empty list. */
4510 ssh2_pkt_addstring_start(s->pktout);
4511 /* List server->client languages. Empty list. */
4512 ssh2_pkt_addstring_start(s->pktout);
4513 /* First KEX packet does _not_ follow, because we're not that brave. */
4514 ssh2_pkt_addbool(s->pktout, FALSE);
4516 ssh2_pkt_adduint32(s->pktout, 0);
4519 ssh->exhash = ssh->exhashbase;
4520 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4522 ssh2_pkt_send_noqueue(ssh, s->pktout);
4526 if (pktin->length > 5)
4527 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4530 * Now examine the other side's KEXINIT to see what we're up
4537 if (pktin->type != SSH2_MSG_KEXINIT) {
4538 bombout(("expected key exchange packet from server"));
4542 ssh->hostkey = NULL;
4543 s->cscipher_tobe = NULL;
4544 s->sccipher_tobe = NULL;
4545 s->csmac_tobe = NULL;
4546 s->scmac_tobe = NULL;
4547 s->cscomp_tobe = NULL;
4548 s->sccomp_tobe = NULL;
4549 pktin->savedpos += 16; /* skip garbage cookie */
4550 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4552 for (i = 0; i < s->n_preferred_kex; i++) {
4553 const struct ssh_kex *k = s->preferred_kex[i];
4556 } else if (in_commasep_string(k->name, str, len)) {
4561 askalg(ssh->frontend, "key-exchange algorithm",
4567 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4568 str ? str : "(null)"));
4571 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4572 for (i = 0; i < lenof(hostkey_algs); i++) {
4573 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4574 ssh->hostkey = hostkey_algs[i];
4578 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4580 for (i = 0; i < s->n_preferred_ciphers; i++) {
4581 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4585 for (j = 0; j < c->nciphers; j++) {
4586 if (in_commasep_string(c->list[j]->name, str, len)) {
4587 s->cscipher_tobe = c->list[j];
4592 if (s->cscipher_tobe) {
4594 askalg(ssh->frontend, "client-to-server cipher",
4595 s->cscipher_tobe->name);
4599 if (!s->cscipher_tobe) {
4600 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4601 str ? str : "(null)"));
4605 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4607 for (i = 0; i < s->n_preferred_ciphers; i++) {
4608 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4612 for (j = 0; j < c->nciphers; j++) {
4613 if (in_commasep_string(c->list[j]->name, str, len)) {
4614 s->sccipher_tobe = c->list[j];
4619 if (s->sccipher_tobe) {
4621 askalg(ssh->frontend, "server-to-client cipher",
4622 s->sccipher_tobe->name);
4626 if (!s->sccipher_tobe) {
4627 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4628 str ? str : "(null)"));
4632 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4633 for (i = 0; i < s->nmacs; i++) {
4634 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4635 s->csmac_tobe = s->maclist[i];
4639 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4640 for (i = 0; i < s->nmacs; i++) {
4641 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4642 s->scmac_tobe = s->maclist[i];
4646 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4647 for (i = 0; i < lenof(compressions) + 1; i++) {
4648 const struct ssh_compress *c =
4649 i == 0 ? s->preferred_comp : compressions[i - 1];
4650 if (in_commasep_string(c->name, str, len)) {
4655 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
4656 for (i = 0; i < lenof(compressions) + 1; i++) {
4657 const struct ssh_compress *c =
4658 i == 0 ? s->preferred_comp : compressions[i - 1];
4659 if (in_commasep_string(c->name, str, len)) {
4667 * Work out the number of bits of key we will need from the key
4668 * exchange. We start with the maximum key length of either
4674 csbits = s->cscipher_tobe->keylen;
4675 scbits = s->sccipher_tobe->keylen;
4676 s->nbits = (csbits > scbits ? csbits : scbits);
4678 /* The keys only have 160-bit entropy, since they're based on
4679 * a SHA-1 hash. So cap the key size at 160 bits. */
4684 * If we're doing Diffie-Hellman group exchange, start by
4685 * requesting a group.
4687 if (!ssh->kex->pdata) {
4688 logevent("Doing Diffie-Hellman group exchange");
4689 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4691 * Work out how big a DH group we will need to allow that
4694 s->pbits = 512 << ((s->nbits - 1) / 64);
4695 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4696 ssh2_pkt_adduint32(s->pktout, s->pbits);
4697 ssh2_pkt_send_noqueue(ssh, s->pktout);
4700 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4701 bombout(("expected key exchange group packet from server"));
4704 s->p = ssh2_pkt_getmp(pktin);
4705 s->g = ssh2_pkt_getmp(pktin);
4706 if (!s->p || !s->g) {
4707 bombout(("unable to read mp-ints from incoming group packet"));
4710 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
4711 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4712 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4714 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
4715 ssh->kex_ctx = dh_setup_group(ssh->kex);
4716 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4717 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4718 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
4719 ssh->kex->groupname);
4722 logevent("Doing Diffie-Hellman key exchange");
4724 * Now generate and send e for Diffie-Hellman.
4726 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4727 s->pktout = ssh2_pkt_init(s->kex_init_value);
4728 ssh2_pkt_addmp(s->pktout, s->e);
4729 ssh2_pkt_send_noqueue(ssh, s->pktout);
4732 if (pktin->type != s->kex_reply_value) {
4733 bombout(("expected key exchange reply packet from server"));
4736 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4737 s->f = ssh2_pkt_getmp(pktin);
4739 bombout(("unable to parse key exchange reply packet"));
4742 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
4744 s->K = dh_find_K(ssh->kex_ctx, s->f);
4746 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4747 if (ssh->kex == &ssh_diffiehellman_gex) {
4748 sha_uint32(&ssh->exhash, s->pbits);
4749 sha_mpint(&ssh->exhash, s->p);
4750 sha_mpint(&ssh->exhash, s->g);
4752 sha_mpint(&ssh->exhash, s->e);
4753 sha_mpint(&ssh->exhash, s->f);
4754 sha_mpint(&ssh->exhash, s->K);
4755 SHA_Final(&ssh->exhash, s->exchange_hash);
4757 dh_cleanup(ssh->kex_ctx);
4758 ssh->kex_ctx = NULL;
4761 debug(("Exchange hash is:\n"));
4762 dmemdump(s->exchange_hash, 20);
4765 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4767 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4768 (char *)s->exchange_hash, 20)) {
4769 bombout(("Server's host key did not match the signature supplied"));
4774 * Authenticate remote host: verify host key. (We've already
4775 * checked the signature of the exchange hash.)
4777 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4778 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4779 verify_ssh_host_key(ssh->frontend,
4780 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4781 s->keystr, s->fingerprint);
4782 if (s->first_kex) { /* don't bother logging this in rekeys */
4783 logevent("Host key fingerprint is:");
4784 logevent(s->fingerprint);
4786 sfree(s->fingerprint);
4788 ssh->hostkey->freekey(s->hkey);
4791 * The exchange hash from the very first key exchange is also
4792 * the session id, used in session key construction and
4796 memcpy(ssh->v2_session_id, s->exchange_hash,
4797 sizeof(s->exchange_hash));
4800 * Send SSH2_MSG_NEWKEYS.
4802 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
4803 ssh2_pkt_send_noqueue(ssh, s->pktout);
4804 ssh->outgoing_data_size = 0; /* start counting from here */
4807 * We've sent client NEWKEYS, so create and initialise
4808 * client-to-server session keys.
4810 if (ssh->cs_cipher_ctx)
4811 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4812 ssh->cscipher = s->cscipher_tobe;
4813 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4815 if (ssh->cs_mac_ctx)
4816 ssh->csmac->free_context(ssh->cs_mac_ctx);
4817 ssh->csmac = s->csmac_tobe;
4818 ssh->cs_mac_ctx = ssh->csmac->make_context();
4820 if (ssh->cs_comp_ctx)
4821 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4822 ssh->cscomp = s->cscomp_tobe;
4823 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4826 * Set IVs on client-to-server keys. Here we use the exchange
4827 * hash from the _first_ key exchange.
4830 unsigned char keyspace[40];
4831 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4832 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4833 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4834 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4835 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4836 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4839 logeventf(ssh, "Initialised %.200s client->server encryption",
4840 ssh->cscipher->text_name);
4841 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4842 ssh->csmac->text_name);
4843 if (ssh->cscomp->text_name)
4844 logeventf(ssh, "Initialised %s compression",
4845 ssh->cscomp->text_name);
4848 * Now our end of the key exchange is complete, we can send all
4849 * our queued higher-layer packets.
4851 ssh->queueing = FALSE;
4852 ssh2_pkt_queuesend(ssh);
4855 * Expect SSH2_MSG_NEWKEYS from server.
4858 if (pktin->type != SSH2_MSG_NEWKEYS) {
4859 bombout(("expected new-keys packet from server"));
4862 ssh->incoming_data_size = 0; /* start counting from here */
4865 * We've seen server NEWKEYS, so create and initialise
4866 * server-to-client session keys.
4868 if (ssh->sc_cipher_ctx)
4869 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4870 ssh->sccipher = s->sccipher_tobe;
4871 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4873 if (ssh->sc_mac_ctx)
4874 ssh->scmac->free_context(ssh->sc_mac_ctx);
4875 ssh->scmac = s->scmac_tobe;
4876 ssh->sc_mac_ctx = ssh->scmac->make_context();
4878 if (ssh->sc_comp_ctx)
4879 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4880 ssh->sccomp = s->sccomp_tobe;
4881 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4884 * Set IVs on server-to-client keys. Here we use the exchange
4885 * hash from the _first_ key exchange.
4888 unsigned char keyspace[40];
4889 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4890 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4891 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4892 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4893 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4894 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4896 logeventf(ssh, "Initialised %.200s server->client encryption",
4897 ssh->sccipher->text_name);
4898 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4899 ssh->scmac->text_name);
4900 if (ssh->sccomp->text_name)
4901 logeventf(ssh, "Initialised %s decompression",
4902 ssh->sccomp->text_name);
4905 * Free key exchange data.
4909 if (ssh->kex == &ssh_diffiehellman_gex) {
4915 * Key exchange is over. Schedule a timer for our next rekey.
4917 ssh->kex_in_progress = FALSE;
4918 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4921 * If this is the first key exchange phase, we must pass the
4922 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4923 * wants to see it but because it will need time to initialise
4924 * itself before it sees an actual packet. In subsequent key
4925 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4926 * it would only confuse the layer above.
4928 if (!s->first_kex) {
4934 * Now we're encrypting. Begin returning 1 to the protocol main
4935 * function so that other things can run on top of the
4936 * transport. If we ever see a KEXINIT, we must go back to the
4939 * We _also_ go back to the start if we see pktin==NULL and
4940 * inlen==-1, because this is a special signal meaning
4941 * `initiate client-driven rekey', and `in' contains a message
4942 * giving the reason for the rekey.
4944 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4945 (!pktin && inlen == -1))) {
4949 logevent("Server initiated key re-exchange");
4951 logevent((char *)in);
4953 goto begin_key_exchange;
4959 * Add data to an SSH2 channel output buffer.
4961 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4964 bufchain_add(&c->v.v2.outbuffer, buf, len);
4968 * Attempt to send data on an SSH2 channel.
4970 static int ssh2_try_send(struct ssh_channel *c)
4973 struct Packet *pktout;
4975 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4978 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4979 if ((unsigned)len > c->v.v2.remwindow)
4980 len = c->v.v2.remwindow;
4981 if ((unsigned)len > c->v.v2.remmaxpkt)
4982 len = c->v.v2.remmaxpkt;
4983 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4984 ssh2_pkt_adduint32(pktout, c->remoteid);
4985 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4986 ssh2_pkt_addstring_start(pktout);
4987 ssh2_pkt_addstring_data(pktout, data, len);
4988 end_log_omission(ssh, pktout);
4989 ssh2_pkt_send(ssh, pktout);
4990 bufchain_consume(&c->v.v2.outbuffer, len);
4991 c->v.v2.remwindow -= len;
4995 * After having sent as much data as we can, return the amount
4998 return bufchain_size(&c->v.v2.outbuffer);
5002 * Potentially enlarge the window on an SSH2 channel.
5004 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5009 * Never send WINDOW_ADJUST for a channel that the remote side
5010 * already thinks it's closed; there's no point, since it won't
5011 * be sending any more data anyway.
5016 if (newwin > c->v.v2.locwindow) {
5017 struct Packet *pktout;
5019 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5020 ssh2_pkt_adduint32(pktout, c->remoteid);
5021 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5022 ssh2_pkt_send(ssh, pktout);
5023 c->v.v2.locwindow = newwin;
5027 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5029 unsigned i = ssh_pkt_getuint32(pktin);
5030 struct ssh_channel *c;
5031 c = find234(ssh->channels, &i, ssh_channelfind);
5032 if (c && !c->closes)
5033 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5036 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5040 unsigned i = ssh_pkt_getuint32(pktin);
5041 struct ssh_channel *c;
5042 c = find234(ssh->channels, &i, ssh_channelfind);
5044 return; /* nonexistent channel */
5045 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5046 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5047 return; /* extended but not stderr */
5048 ssh_pkt_getstring(pktin, &data, &length);
5051 c->v.v2.locwindow -= length;
5053 case CHAN_MAINSESSION:
5055 from_backend(ssh->frontend, pktin->type ==
5056 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5060 bufsize = x11_send(c->u.x11.s, data, length);
5063 bufsize = pfd_send(c->u.pfd.s, data, length);
5066 while (length > 0) {
5067 if (c->u.a.lensofar < 4) {
5068 int l = min(4 - c->u.a.lensofar, length);
5069 memcpy(c->u.a.msglen + c->u.a.lensofar,
5073 c->u.a.lensofar += l;
5075 if (c->u.a.lensofar == 4) {
5077 4 + GET_32BIT(c->u.a.msglen);
5078 c->u.a.message = snewn(c->u.a.totallen,
5080 memcpy(c->u.a.message, c->u.a.msglen, 4);
5082 if (c->u.a.lensofar >= 4 && length > 0) {
5084 min(c->u.a.totallen - c->u.a.lensofar,
5086 memcpy(c->u.a.message + c->u.a.lensofar,
5090 c->u.a.lensofar += l;
5092 if (c->u.a.lensofar == c->u.a.totallen) {
5095 if (agent_query(c->u.a.message,
5098 ssh_agentf_callback, c))
5099 ssh_agentf_callback(c, reply, replylen);
5100 sfree(c->u.a.message);
5101 c->u.a.lensofar = 0;
5108 * If we are not buffering too much data,
5109 * enlarge the window again at the remote side.
5111 if (bufsize < OUR_V2_WINSIZE)
5112 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5116 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5118 unsigned i = ssh_pkt_getuint32(pktin);
5119 struct ssh_channel *c;
5121 c = find234(ssh->channels, &i, ssh_channelfind);
5123 return; /* nonexistent channel */
5125 if (c->type == CHAN_X11) {
5127 * Remote EOF on an X11 channel means we should
5128 * wrap up and close the channel ourselves.
5130 x11_close(c->u.x11.s);
5132 } else if (c->type == CHAN_AGENT) {
5134 } else if (c->type == CHAN_SOCKDATA) {
5135 pfd_close(c->u.pfd.s);
5140 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5142 unsigned i = ssh_pkt_getuint32(pktin);
5143 struct ssh_channel *c;
5144 struct Packet *pktout;
5146 c = find234(ssh->channels, &i, ssh_channelfind);
5147 if (!c || ((int)c->remoteid) == -1) {
5148 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5149 c ? "half-open" : "nonexistent", i));
5152 /* Do pre-close processing on the channel. */
5154 case CHAN_MAINSESSION:
5155 ssh->mainchan = NULL;
5156 update_specials_menu(ssh->frontend);
5159 if (c->u.x11.s != NULL)
5160 x11_close(c->u.x11.s);
5167 if (c->u.pfd.s != NULL)
5168 pfd_close(c->u.pfd.s);
5172 if (c->closes == 0) {
5173 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5174 ssh2_pkt_adduint32(pktout, c->remoteid);
5175 ssh2_pkt_send(ssh, pktout);
5177 del234(ssh->channels, c);
5178 bufchain_clear(&c->v.v2.outbuffer);
5182 * See if that was the last channel left open.
5183 * (This is only our termination condition if we're
5184 * not running in -N mode.)
5186 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5187 logevent("All channels closed. Disconnecting");
5190 * We used to send SSH_MSG_DISCONNECT here,
5191 * because I'd believed that _every_ conforming
5192 * SSH2 connection had to end with a disconnect
5193 * being sent by at least one side; apparently
5194 * I was wrong and it's perfectly OK to
5195 * unceremoniously slam the connection shut
5196 * when you're done, and indeed OpenSSH feels
5197 * this is more polite than sending a
5198 * DISCONNECT. So now we don't.
5200 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5201 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5202 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5203 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5204 ssh2_pkt_send_noqueue(ssh, s->pktout);
5206 ssh_closing((Plug)ssh, NULL, 0, 0);
5210 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5212 unsigned i = ssh_pkt_getuint32(pktin);
5213 struct ssh_channel *c;
5214 struct Packet *pktout;
5216 c = find234(ssh->channels, &i, ssh_channelfind);
5218 return; /* nonexistent channel */
5219 if (c->type != CHAN_SOCKDATA_DORMANT)
5220 return; /* dunno why they're confirming this */
5221 c->remoteid = ssh_pkt_getuint32(pktin);
5222 c->type = CHAN_SOCKDATA;
5223 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5224 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5226 pfd_confirm(c->u.pfd.s);
5229 * We have a pending close on this channel,
5230 * which we decided on before the server acked
5231 * the channel open. So now we know the
5232 * remoteid, we can close it again.
5234 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5235 ssh2_pkt_adduint32(pktout, c->remoteid);
5236 ssh2_pkt_send(ssh, pktout);
5240 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5242 static const char *const reasons[] = {
5243 "<unknown reason code>",
5244 "Administratively prohibited",
5246 "Unknown channel type",
5247 "Resource shortage",
5249 unsigned i = ssh_pkt_getuint32(pktin);
5250 unsigned reason_code;
5251 char *reason_string;
5254 struct ssh_channel *c;
5255 c = find234(ssh->channels, &i, ssh_channelfind);
5257 return; /* nonexistent channel */
5258 if (c->type != CHAN_SOCKDATA_DORMANT)
5259 return; /* dunno why they're failing this */
5261 reason_code = ssh_pkt_getuint32(pktin);
5262 if (reason_code >= lenof(reasons))
5263 reason_code = 0; /* ensure reasons[reason_code] in range */
5264 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5265 message = dupprintf("Forwarded connection refused by"
5266 " server: %s [%.*s]", reasons[reason_code],
5267 reason_length, reason_string);
5271 pfd_close(c->u.pfd.s);
5273 del234(ssh->channels, c);
5277 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5281 int typelen, want_reply;
5282 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5283 struct ssh_channel *c;
5284 struct Packet *pktout;
5286 localid = ssh_pkt_getuint32(pktin);
5287 ssh_pkt_getstring(pktin, &type, &typelen);
5288 want_reply = ssh2_pkt_getbool(pktin);
5291 * First, check that the channel exists. Otherwise,
5292 * we can instantly disconnect with a rude message.
5294 c = find234(ssh->channels, &localid, ssh_channelfind);
5297 sprintf(buf, "Received channel request for nonexistent"
5298 " channel %d", localid);
5300 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5301 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5302 ssh2_pkt_addstring(pktout, buf);
5303 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5304 ssh2_pkt_send_noqueue(ssh, pktout);
5305 connection_fatal(ssh->frontend, "%s", buf);
5306 ssh_closing((Plug)ssh, NULL, 0, 0);
5311 * Having got the channel number, we now look at
5312 * the request type string to see if it's something
5315 if (c == ssh->mainchan) {
5317 * We recognise "exit-status" and "exit-signal" on
5318 * the primary channel.
5320 if (typelen == 11 &&
5321 !memcmp(type, "exit-status", 11)) {
5323 ssh->exitcode = ssh_pkt_getuint32(pktin);
5324 logeventf(ssh, "Server sent command exit status %d",
5326 reply = SSH2_MSG_CHANNEL_SUCCESS;
5328 } else if (typelen == 11 &&
5329 !memcmp(type, "exit-signal", 11)) {
5331 int is_plausible = TRUE, is_int = FALSE;
5332 char *fmt_sig = "", *fmt_msg = "";
5334 int msglen = 0, core = FALSE;
5335 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5336 * provide an `int' for the signal, despite its
5337 * having been a `string' in the drafts since at
5338 * least 2001. (Fixed in session.c 1.147.) Try to
5339 * infer which we can safely parse it as. */
5341 unsigned char *p = pktin->body +
5343 long len = pktin->length - pktin->savedpos;
5344 unsigned long num = GET_32BIT(p); /* what is it? */
5345 /* If it's 0, it hardly matters; assume string */
5349 int maybe_int = FALSE, maybe_str = FALSE;
5350 #define CHECK_HYPOTHESIS(offset, result) \
5353 if (q >= 0 && q+4 <= len) { \
5354 q = q + 4 + GET_32BIT(p+q); \
5355 if (q >= 0 && q+4 <= len && \
5356 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5360 CHECK_HYPOTHESIS(4+1, maybe_int);
5361 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5362 #undef CHECK_HYPOTHESIS
5363 if (maybe_int && !maybe_str)
5365 else if (!maybe_int && maybe_str)
5368 /* Crikey. Either or neither. Panic. */
5369 is_plausible = FALSE;
5374 /* Old non-standard OpenSSH. */
5375 int signum = ssh_pkt_getuint32(pktin);
5376 fmt_sig = dupprintf(" %d", signum);
5378 /* As per the drafts. */
5381 ssh_pkt_getstring(pktin, &sig, &siglen);
5382 /* Signal name isn't supposed to be blank, but
5383 * let's cope gracefully if it is. */
5385 fmt_sig = dupprintf(" \"%.*s\"",
5389 core = ssh2_pkt_getbool(pktin);
5390 ssh_pkt_getstring(pktin, &msg, &msglen);
5392 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5394 /* ignore lang tag */
5395 } /* else don't attempt to parse */
5396 logeventf(ssh, "Server exited on signal%s%s%s",
5397 fmt_sig, core ? " (core dumped)" : "",
5399 if (*fmt_sig) sfree(fmt_sig);
5400 if (*fmt_msg) sfree(fmt_msg);
5401 reply = SSH2_MSG_CHANNEL_SUCCESS;
5406 * This is a channel request we don't know
5407 * about, so we now either ignore the request
5408 * or respond with CHANNEL_FAILURE, depending
5411 reply = SSH2_MSG_CHANNEL_FAILURE;
5414 pktout = ssh2_pkt_init(reply);
5415 ssh2_pkt_adduint32(pktout, c->remoteid);
5416 ssh2_pkt_send(ssh, pktout);
5420 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5423 int typelen, want_reply;
5424 struct Packet *pktout;
5426 ssh_pkt_getstring(pktin, &type, &typelen);
5427 want_reply = ssh2_pkt_getbool(pktin);
5430 * We currently don't support any global requests
5431 * at all, so we either ignore the request or
5432 * respond with REQUEST_FAILURE, depending on
5436 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5437 ssh2_pkt_send(ssh, pktout);
5441 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5449 struct ssh_channel *c;
5450 unsigned remid, winsize, pktsize;
5451 struct Packet *pktout;
5453 ssh_pkt_getstring(pktin, &type, &typelen);
5454 c = snew(struct ssh_channel);
5457 remid = ssh_pkt_getuint32(pktin);
5458 winsize = ssh_pkt_getuint32(pktin);
5459 pktsize = ssh_pkt_getuint32(pktin);
5461 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5464 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5465 addrstr = snewn(peeraddrlen+1, char);
5466 memcpy(addrstr, peeraddr, peeraddrlen);
5467 addrstr[peeraddrlen] = '\0';
5468 peerport = ssh_pkt_getuint32(pktin);
5470 logeventf(ssh, "Received X11 connect request from %s:%d",
5473 if (!ssh->X11_fwd_enabled)
5474 error = "X11 forwarding is not enabled";
5475 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5476 ssh->x11auth, addrstr, peerport,
5477 &ssh->cfg) != NULL) {
5478 error = "Unable to open an X11 connection";
5480 logevent("Opening X11 forward connection succeeded");
5485 } else if (typelen == 15 &&
5486 !memcmp(type, "forwarded-tcpip", 15)) {
5487 struct ssh_rportfwd pf, *realpf;
5490 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5491 pf.sport = ssh_pkt_getuint32(pktin);
5492 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5493 peerport = ssh_pkt_getuint32(pktin);
5494 realpf = find234(ssh->rportfwds, &pf, NULL);
5495 logeventf(ssh, "Received remote port %d open request "
5496 "from %s:%d", pf.sport, peeraddr, peerport);
5497 if (realpf == NULL) {
5498 error = "Remote port is not recognised";
5500 const char *e = pfd_newconnect(&c->u.pfd.s,
5504 logeventf(ssh, "Attempting to forward remote port to "
5505 "%s:%d", realpf->dhost, realpf->dport);
5507 logeventf(ssh, "Port open failed: %s", e);
5508 error = "Port open failed";
5510 logevent("Forwarded port opened successfully");
5511 c->type = CHAN_SOCKDATA;
5514 } else if (typelen == 22 &&
5515 !memcmp(type, "auth-agent@openssh.com", 3)) {
5516 if (!ssh->agentfwd_enabled)
5517 error = "Agent forwarding is not enabled";
5519 c->type = CHAN_AGENT; /* identify channel type */
5520 c->u.a.lensofar = 0;
5523 error = "Unsupported channel type requested";
5526 c->remoteid = remid;
5528 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5529 ssh2_pkt_adduint32(pktout, c->remoteid);
5530 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5531 ssh2_pkt_addstring(pktout, error);
5532 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5533 ssh2_pkt_send(ssh, pktout);
5534 logeventf(ssh, "Rejected channel open: %s", error);
5537 c->localid = alloc_channel_id(ssh);
5539 c->v.v2.locwindow = OUR_V2_WINSIZE;
5540 c->v.v2.remwindow = winsize;
5541 c->v.v2.remmaxpkt = pktsize;
5542 bufchain_init(&c->v.v2.outbuffer);
5543 add234(ssh->channels, c);
5544 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5545 ssh2_pkt_adduint32(pktout, c->remoteid);
5546 ssh2_pkt_adduint32(pktout, c->localid);
5547 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5548 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5549 ssh2_pkt_send(ssh, pktout);
5554 * Handle the SSH2 userauth and connection layers.
5556 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5557 struct Packet *pktin)
5559 struct do_ssh2_authconn_state {
5561 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5563 AUTH_KEYBOARD_INTERACTIVE
5567 AUTH_TYPE_PUBLICKEY,
5568 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5569 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5571 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5572 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5574 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5575 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5576 int kbd_inter_running;
5578 int num_prompts, curr_prompt, echo;
5583 void *publickey_blob;
5584 int publickey_bloblen;
5585 unsigned char request[5], *response, *p;
5589 char *pkblob, *alg, *commentp;
5590 int pklen, alglen, commentlen;
5591 int siglen, retlen, len;
5592 char *q, *agentreq, *ret;
5594 int num_env, env_left, env_ok;
5595 struct Packet *pktout;
5597 crState(do_ssh2_authconn_state);
5599 crBegin(ssh->do_ssh2_authconn_crstate);
5602 * Request userauth protocol, and await a response to it.
5604 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5605 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5606 ssh2_pkt_send(ssh, s->pktout);
5607 crWaitUntilV(pktin);
5608 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5609 bombout(("Server refused user authentication protocol"));
5614 * We repeat this whole loop, including the username prompt,
5615 * until we manage a successful authentication. If the user
5616 * types the wrong _password_, they can be sent back to the
5617 * beginning to try another username, if this is configured on.
5618 * (If they specify a username in the config, they are never
5619 * asked, even if they do give a wrong password.)
5621 * I think this best serves the needs of
5623 * - the people who have no configuration, no keys, and just
5624 * want to try repeated (username,password) pairs until they
5625 * type both correctly
5627 * - people who have keys and configuration but occasionally
5628 * need to fall back to passwords
5630 * - people with a key held in Pageant, who might not have
5631 * logged in to a particular machine before; so they want to
5632 * type a username, and then _either_ their key will be
5633 * accepted, _or_ they will type a password. If they mistype
5634 * the username they will want to be able to get back and
5637 s->username[0] = '\0';
5638 s->got_username = FALSE;
5643 if (s->got_username && !ssh->cfg.change_username) {
5645 * We got a username last time round this loop, and
5646 * with change_username turned off we don't try to get
5649 } else if (!*ssh->cfg.username) {
5650 if (ssh_get_line && !ssh_getline_pw_only) {
5651 if (!ssh_get_line("login as: ",
5652 s->username, sizeof(s->username), FALSE)) {
5654 * get_line failed to get a username.
5657 logevent("No username provided. Abandoning session.");
5658 ssh_closing((Plug)ssh, NULL, 0, 0);
5662 int ret; /* need not be saved across crReturn */
5663 c_write_str(ssh, "login as: ");
5665 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
5667 crWaitUntilV(!pktin);
5668 ret = process_userpass_input(ssh, in, inlen);
5672 c_write_str(ssh, "\r\n");
5674 s->username[strcspn(s->username, "\n\r")] = '\0';
5677 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
5678 s->username[sizeof(s->username)-1] = '\0';
5679 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
5680 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
5681 c_write_str(ssh, stuff);
5685 s->got_username = TRUE;
5688 * Send an authentication request using method "none": (a)
5689 * just in case it succeeds, and (b) so that we know what
5690 * authentication methods we can usefully try next.
5692 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5694 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5695 ssh2_pkt_addstring(s->pktout, s->username);
5696 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5697 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5698 ssh2_pkt_send(ssh, s->pktout);
5699 s->type = AUTH_TYPE_NONE;
5701 s->we_are_in = FALSE;
5703 s->tried_pubkey_config = FALSE;
5704 s->tried_agent = FALSE;
5705 s->tried_keyb_inter = FALSE;
5706 s->kbd_inter_running = FALSE;
5707 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
5708 if (!filename_is_null(ssh->cfg.keyfile)) {
5710 logeventf(ssh, "Reading private key file \"%.150s\"",
5711 filename_to_str(&ssh->cfg.keyfile));
5712 keytype = key_type(&ssh->cfg.keyfile);
5713 if (keytype == SSH_KEYTYPE_SSH2) {
5715 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
5716 &s->publickey_bloblen, NULL);
5719 logeventf(ssh, "Unable to use this key file (%s)",
5720 key_type_to_str(keytype));
5721 msgbuf = dupprintf("Unable to use key file \"%.150s\""
5723 filename_to_str(&ssh->cfg.keyfile),
5724 key_type_to_str(keytype));
5725 c_write_str(ssh, msgbuf);
5727 s->publickey_blob = NULL;
5730 s->publickey_blob = NULL;
5734 * Wait for the result of the last authentication request.
5737 crWaitUntilV(pktin);
5738 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
5742 * Don't show the banner if we're operating in
5743 * non-verbose non-interactive mode. (It's probably
5744 * a script, which means nobody will read the
5745 * banner _anyway_, and moreover the printing of
5746 * the banner will screw up processing on the
5747 * output of (say) plink.)
5749 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
5750 ssh_pkt_getstring(pktin, &banner, &size);
5752 c_write_untrusted(ssh, banner, size);
5754 crWaitUntilV(pktin);
5756 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
5757 logevent("Access granted");
5758 s->we_are_in = TRUE;
5762 if (s->kbd_inter_running &&
5763 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
5765 * This is either a further set-of-prompts packet
5766 * in keyboard-interactive authentication, or it's
5767 * the same one and we came back here with `gotit'
5768 * set. In the former case, we must reset the
5769 * curr_prompt variable.
5773 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
5774 bombout(("Strange packet received during authentication: type %d",
5782 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5783 * we can look at the string in it and know what we can
5784 * helpfully try next.
5786 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
5789 ssh_pkt_getstring(pktin, &methods, &methlen);
5790 s->kbd_inter_running = FALSE;
5791 if (!ssh2_pkt_getbool(pktin)) {
5793 * We have received an unequivocal Access
5794 * Denied. This can translate to a variety of
5797 * - if we'd just tried "none" authentication,
5798 * it's not worth printing anything at all
5800 * - if we'd just tried a public key _offer_,
5801 * the message should be "Server refused our
5802 * key" (or no message at all if the key
5803 * came from Pageant)
5805 * - if we'd just tried anything else, the
5806 * message really should be "Access denied".
5808 * Additionally, if we'd just tried password
5809 * authentication, we should break out of this
5810 * whole loop so as to go back to the username
5811 * prompt (iff we're configured to allow
5812 * username change attempts).
5814 if (s->type == AUTH_TYPE_NONE) {
5816 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5817 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5818 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5819 c_write_str(ssh, "Server refused our key\r\n");
5820 logevent("Server refused public key");
5821 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5822 /* server declined keyboard-interactive; ignore */
5824 c_write_str(ssh, "Access denied\r\n");
5825 logevent("Access denied");
5826 if (s->type == AUTH_TYPE_PASSWORD &&
5827 ssh->cfg.change_username) {
5828 /* XXX perhaps we should allow
5829 * keyboard-interactive to do this too? */
5830 s->we_are_in = FALSE;
5835 c_write_str(ssh, "Further authentication required\r\n");
5836 logevent("Further authentication required");
5840 in_commasep_string("publickey", methods, methlen);
5842 in_commasep_string("password", methods, methlen);
5843 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5844 in_commasep_string("keyboard-interactive", methods, methlen);
5848 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5852 * Most password/passphrase prompts will be
5853 * non-echoing, so we set this to 0 by default.
5854 * Exception is that some keyboard-interactive prompts
5855 * can be echoing, in which case we'll set this to 1.
5859 if (!s->method && s->can_pubkey &&
5860 agent_exists() && !s->tried_agent) {
5862 * Attempt public-key authentication using Pageant.
5867 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5868 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5870 s->tried_agent = TRUE;
5872 logevent("Pageant is running. Requesting keys.");
5874 /* Request the keys held by the agent. */
5875 PUT_32BIT(s->request, 1);
5876 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5877 if (!agent_query(s->request, 5, &r, &s->responselen,
5878 ssh_agent_callback, ssh)) {
5882 bombout(("Unexpected data from server while"
5883 " waiting for agent response"));
5886 } while (pktin || inlen > 0);
5887 r = ssh->agent_response;
5888 s->responselen = ssh->agent_response_len;
5890 s->response = (unsigned char *) r;
5891 if (s->response && s->responselen >= 5 &&
5892 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5893 s->p = s->response + 5;
5894 s->nkeys = GET_32BIT(s->p);
5898 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5901 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5906 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5909 s->pklen = GET_32BIT(s->p);
5911 if (s->publickey_blob &&
5912 s->pklen == s->publickey_bloblen &&
5913 !memcmp(s->p, s->publickey_blob,
5914 s->publickey_bloblen)) {
5915 logevent("This key matches configured key file");
5916 s->tried_pubkey_config = 1;
5918 s->pkblob = (char *)s->p;
5920 s->alglen = GET_32BIT(s->pkblob);
5921 s->alg = s->pkblob + 4;
5922 s->commentlen = GET_32BIT(s->p);
5924 s->commentp = (char *)s->p;
5925 s->p += s->commentlen;
5926 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5927 ssh2_pkt_addstring(s->pktout, s->username);
5928 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5929 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5930 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5931 ssh2_pkt_addstring_start(s->pktout);
5932 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5933 ssh2_pkt_addstring_start(s->pktout);
5934 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5935 ssh2_pkt_send(ssh, s->pktout);
5937 crWaitUntilV(pktin);
5938 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
5939 logevent("Key refused");
5943 if (flags & FLAG_VERBOSE) {
5944 c_write_str(ssh, "Authenticating with "
5946 c_write(ssh, s->commentp, s->commentlen);
5947 c_write_str(ssh, "\" from agent\r\n");
5951 * Server is willing to accept the key.
5952 * Construct a SIGN_REQUEST.
5954 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5955 ssh2_pkt_addstring(s->pktout, s->username);
5956 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5957 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5958 ssh2_pkt_addbool(s->pktout, TRUE);
5959 ssh2_pkt_addstring_start(s->pktout);
5960 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5961 ssh2_pkt_addstring_start(s->pktout);
5962 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5964 s->siglen = s->pktout->length - 5 + 4 + 20;
5965 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5967 s->len = 1; /* message type */
5968 s->len += 4 + s->pklen; /* key blob */
5969 s->len += 4 + s->siglen; /* data to sign */
5970 s->len += 4; /* flags */
5971 s->agentreq = snewn(4 + s->len, char);
5972 PUT_32BIT(s->agentreq, s->len);
5973 s->q = s->agentreq + 4;
5974 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5975 PUT_32BIT(s->q, s->pklen);
5977 memcpy(s->q, s->pkblob, s->pklen);
5979 PUT_32BIT(s->q, s->siglen);
5981 /* Now the data to be signed... */
5982 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5983 PUT_32BIT(s->q, 20);
5986 memcpy(s->q, ssh->v2_session_id, 20);
5988 memcpy(s->q, s->pktout->data + 5,
5989 s->pktout->length - 5);
5990 s->q += s->pktout->length - 5;
5991 /* And finally the (zero) flags word. */
5993 if (!agent_query(s->agentreq, s->len + 4,
5995 ssh_agent_callback, ssh)) {
5999 bombout(("Unexpected data from server"
6000 " while waiting for agent"
6004 } while (pktin || inlen > 0);
6005 vret = ssh->agent_response;
6006 s->retlen = ssh->agent_response_len;
6011 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6012 logevent("Sending Pageant's response");
6013 ssh2_add_sigblob(ssh, s->pktout,
6014 s->pkblob, s->pklen,
6016 GET_32BIT(s->ret + 5));
6017 ssh2_pkt_send(ssh, s->pktout);
6022 ("Pageant failed to answer challenge");
6033 if (!s->method && s->can_pubkey && s->publickey_blob
6034 && !s->tried_pubkey_config) {
6035 unsigned char *pub_blob;
6036 char *algorithm, *comment;
6039 s->tried_pubkey_config = TRUE;
6041 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6042 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6045 * Try the public key supplied in the configuration.
6047 * First, offer the public blob to see if the server is
6048 * willing to accept it.
6051 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6056 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6057 ssh2_pkt_addstring(s->pktout, s->username);
6058 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6059 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6060 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6061 ssh2_pkt_addstring(s->pktout, algorithm);
6062 ssh2_pkt_addstring_start(s->pktout);
6063 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6065 ssh2_pkt_send(ssh, s->pktout);
6066 logevent("Offered public key");
6068 crWaitUntilV(pktin);
6069 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6071 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6072 continue; /* key refused; give up on it */
6075 logevent("Offer of public key accepted");
6077 * Actually attempt a serious authentication using
6080 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6081 sprintf(s->pwprompt,
6082 "Passphrase for key \"%.100s\": ",
6088 if (flags & FLAG_VERBOSE) {
6089 c_write_str(ssh, "Authenticating with public key \"");
6090 c_write_str(ssh, comment);
6091 c_write_str(ssh, "\"\r\n");
6093 s->method = AUTH_PUBLICKEY_FILE;
6097 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6098 s->method = AUTH_KEYBOARD_INTERACTIVE;
6099 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6100 s->tried_keyb_inter = TRUE;
6102 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6103 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6105 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6106 ssh2_pkt_addstring(s->pktout, s->username);
6107 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6108 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6109 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6110 ssh2_pkt_addstring(s->pktout, "");
6111 ssh2_pkt_send(ssh, s->pktout);
6113 crWaitUntilV(pktin);
6114 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6115 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6117 logevent("Keyboard-interactive authentication refused");
6118 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6122 s->kbd_inter_running = TRUE;
6126 if (s->kbd_inter_running) {
6127 s->method = AUTH_KEYBOARD_INTERACTIVE;
6128 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6129 s->tried_keyb_inter = TRUE;
6131 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6132 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6134 if (s->curr_prompt == 0) {
6136 * We've got a fresh USERAUTH_INFO_REQUEST.
6137 * Display header data, and start going through
6140 char *name, *inst, *lang;
6141 int name_len, inst_len, lang_len;
6143 ssh_pkt_getstring(pktin, &name, &name_len);
6144 ssh_pkt_getstring(pktin, &inst, &inst_len);
6145 ssh_pkt_getstring(pktin, &lang, &lang_len);
6147 c_write_untrusted(ssh, name, name_len);
6148 c_write_str(ssh, "\r\n");
6151 c_write_untrusted(ssh, inst, inst_len);
6152 c_write_str(ssh, "\r\n");
6154 s->num_prompts = ssh_pkt_getuint32(pktin);
6158 * If there are prompts remaining in the packet,
6159 * display one and get a response.
6161 if (s->curr_prompt < s->num_prompts) {
6165 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6166 if (prompt_len > 0) {
6167 static const char trunc[] = "<prompt truncated>: ";
6168 static const int prlen = sizeof(s->pwprompt) -
6170 if (prompt_len > prlen) {
6171 memcpy(s->pwprompt, prompt, prlen);
6172 strcpy(s->pwprompt + prlen, trunc);
6174 memcpy(s->pwprompt, prompt, prompt_len);
6175 s->pwprompt[prompt_len] = '\0';
6179 "<server failed to send prompt>: ");
6181 s->echo = ssh2_pkt_getbool(pktin);
6187 if (!s->method && s->can_passwd) {
6188 s->method = AUTH_PASSWORD;
6189 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6190 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6191 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6198 if (!ssh_get_line(s->pwprompt, s->password,
6199 sizeof(s->password), TRUE)) {
6201 * get_line failed to get a password (for
6202 * example because one was supplied on the
6203 * command line which has already failed to
6206 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6207 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6208 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6210 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6211 ssh2_pkt_send_noqueue(ssh, s->pktout);
6212 logevent("Unable to authenticate");
6213 connection_fatal(ssh->frontend,
6214 "Unable to authenticate");
6215 ssh_closing((Plug)ssh, NULL, 0, 0);
6219 int ret; /* need not be saved across crReturn */
6220 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6223 setup_userpass_input(ssh, s->password,
6224 sizeof(s->password), s->echo);
6226 crWaitUntilV(!pktin);
6227 ret = process_userpass_input(ssh, in, inlen);
6231 c_write_str(ssh, "\r\n");
6235 if (s->method == AUTH_PUBLICKEY_FILE) {
6237 * We have our passphrase. Now try the actual authentication.
6239 struct ssh2_userkey *key;
6240 const char *error = NULL;
6242 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6244 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6245 if (key == SSH2_WRONG_PASSPHRASE) {
6246 c_write_str(ssh, "Wrong passphrase\r\n");
6247 s->tried_pubkey_config = FALSE;
6249 c_write_str(ssh, "Unable to load private key (");
6250 c_write_str(ssh, error);
6251 c_write_str(ssh, ")\r\n");
6252 s->tried_pubkey_config = TRUE;
6254 /* Send a spurious AUTH_NONE to return to the top. */
6255 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6256 ssh2_pkt_addstring(s->pktout, s->username);
6257 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6258 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6259 ssh2_pkt_send(ssh, s->pktout);
6260 s->type = AUTH_TYPE_NONE;
6262 unsigned char *pkblob, *sigblob, *sigdata;
6263 int pkblob_len, sigblob_len, sigdata_len;
6267 * We have loaded the private key and the server
6268 * has announced that it's willing to accept it.
6269 * Hallelujah. Generate a signature and send it.
6271 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6272 ssh2_pkt_addstring(s->pktout, s->username);
6273 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6274 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6275 ssh2_pkt_addbool(s->pktout, TRUE);
6276 ssh2_pkt_addstring(s->pktout, key->alg->name);
6277 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6278 ssh2_pkt_addstring_start(s->pktout);
6279 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6282 * The data to be signed is:
6286 * followed by everything so far placed in the
6289 sigdata_len = s->pktout->length - 5 + 4 + 20;
6290 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6292 sigdata = snewn(sigdata_len, unsigned char);
6294 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6295 PUT_32BIT(sigdata+p, 20);
6298 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6299 memcpy(sigdata+p, s->pktout->data + 5,
6300 s->pktout->length - 5);
6301 p += s->pktout->length - 5;
6302 assert(p == sigdata_len);
6303 sigblob = key->alg->sign(key->data, (char *)sigdata,
6304 sigdata_len, &sigblob_len);
6305 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6306 sigblob, sigblob_len);
6311 ssh2_pkt_send(ssh, s->pktout);
6312 s->type = AUTH_TYPE_PUBLICKEY;
6313 key->alg->freekey(key->data);
6315 } else if (s->method == AUTH_PASSWORD) {
6317 * We send the password packet lumped tightly together with
6318 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6319 * string long enough to make the total length of the two
6320 * packets constant. This should ensure that a passive
6321 * listener doing traffic analyis can't work out the length
6324 * For this to work, we need an assumption about the
6325 * maximum length of the password packet. I think 256 is
6326 * pretty conservative. Anyone using a password longer than
6327 * that probably doesn't have much to worry about from
6328 * people who find out how long their password is!
6330 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6331 ssh2_pkt_addstring(s->pktout, s->username);
6332 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6333 ssh2_pkt_addstring(s->pktout, "password");
6334 ssh2_pkt_addbool(s->pktout, FALSE);
6335 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6336 ssh2_pkt_addstring(s->pktout, s->password);
6337 memset(s->password, 0, sizeof(s->password));
6338 end_log_omission(ssh, s->pktout);
6339 ssh2_pkt_defer(ssh, s->pktout);
6341 * We'll include a string that's an exact multiple of the
6342 * cipher block size. If the cipher is NULL for some
6343 * reason, we don't do this trick at all because we gain
6346 if (ssh->cscipher) {
6349 stringlen = (256 - ssh->deferred_len);
6350 stringlen += ssh->cscipher->blksize - 1;
6351 stringlen -= (stringlen % ssh->cscipher->blksize);
6354 * Temporarily disable actual compression,
6355 * so we can guarantee to get this string
6356 * exactly the length we want it. The
6357 * compression-disabling routine should
6358 * return an integer indicating how many
6359 * bytes we should adjust our string length
6363 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6365 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6366 ssh2_pkt_addstring_start(s->pktout);
6367 for (i = 0; i < stringlen; i++) {
6368 char c = (char) random_byte();
6369 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6371 ssh2_pkt_defer(ssh, s->pktout);
6373 ssh_pkt_defersend(ssh);
6374 logevent("Sent password");
6375 s->type = AUTH_TYPE_PASSWORD;
6376 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6377 if (s->curr_prompt == 0) {
6378 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6379 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6381 if (s->need_pw) { /* only add pw if we just got one! */
6382 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6383 ssh2_pkt_addstring(s->pktout, s->password);
6384 memset(s->password, 0, sizeof(s->password));
6385 end_log_omission(ssh, s->pktout);
6388 if (s->curr_prompt >= s->num_prompts) {
6389 ssh2_pkt_send(ssh, s->pktout);
6392 * If there are prompts remaining, we set
6393 * `gotit' so that we won't attempt to get
6394 * another packet. Then we go back round the
6395 * loop and will end up retrieving another
6396 * prompt out of the existing packet. Funky or
6401 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6403 c_write_str(ssh, "No supported authentication methods"
6404 " left to try!\r\n");
6405 logevent("No supported authentications offered."
6407 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6408 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6409 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6410 " methods available");
6411 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6412 ssh2_pkt_send_noqueue(ssh, s->pktout);
6413 ssh_closing((Plug)ssh, NULL, 0, 0);
6417 } while (!s->we_are_in);
6420 * Now we're authenticated for the connection protocol. The
6421 * connection protocol will automatically have started at this
6422 * point; there's no need to send SERVICE_REQUEST.
6425 ssh->channels = newtree234(ssh_channelcmp);
6428 * Set up handlers for some connection protocol messages, so we
6429 * don't have to handle them repeatedly in this coroutine.
6431 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6432 ssh2_msg_channel_window_adjust;
6433 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6434 ssh2_msg_global_request;
6437 * Create the main session channel.
6439 if (!ssh->cfg.ssh_no_shell) {
6440 ssh->mainchan = snew(struct ssh_channel);
6441 ssh->mainchan->ssh = ssh;
6442 ssh->mainchan->localid = alloc_channel_id(ssh);
6443 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6444 ssh2_pkt_addstring(s->pktout, "session");
6445 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6446 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6447 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6448 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6449 ssh2_pkt_send(ssh, s->pktout);
6450 crWaitUntilV(pktin);
6451 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6452 bombout(("Server refused to open a session"));
6454 /* FIXME: error data comes back in FAILURE packet */
6456 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6457 bombout(("Server's channel confirmation cited wrong channel"));
6460 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6461 ssh->mainchan->type = CHAN_MAINSESSION;
6462 ssh->mainchan->closes = 0;
6463 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6464 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6465 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6466 add234(ssh->channels, ssh->mainchan);
6467 update_specials_menu(ssh->frontend);
6468 logevent("Opened channel for session");
6470 ssh->mainchan = NULL;
6473 * Now we have a channel, make dispatch table entries for
6474 * general channel-based messages.
6476 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6477 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6478 ssh2_msg_channel_data;
6479 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6480 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6481 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6482 ssh2_msg_channel_open_confirmation;
6483 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6484 ssh2_msg_channel_open_failure;
6485 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6486 ssh2_msg_channel_request;
6487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6488 ssh2_msg_channel_open;
6491 * Potentially enable X11 forwarding.
6493 if (ssh->mainchan && ssh->cfg.x11_forward) {
6494 char proto[20], data[64];
6495 logevent("Requesting X11 forwarding");
6496 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6497 data, sizeof(data), ssh->cfg.x11_auth);
6498 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6499 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6500 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6501 ssh2_pkt_addstring(s->pktout, "x11-req");
6502 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6503 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6504 ssh2_pkt_addstring(s->pktout, proto);
6505 ssh2_pkt_addstring(s->pktout, data);
6506 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6507 ssh2_pkt_send(ssh, s->pktout);
6509 crWaitUntilV(pktin);
6511 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6512 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6513 bombout(("Unexpected response to X11 forwarding request:"
6514 " packet type %d", pktin->type));
6517 logevent("X11 forwarding refused");
6519 logevent("X11 forwarding enabled");
6520 ssh->X11_fwd_enabled = TRUE;
6525 * Enable port forwardings.
6530 int sport,dport,sserv,dserv;
6531 char sports[256], dports[256], saddr[256], host[256];
6533 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
6534 /* Add port forwardings. */
6535 ssh->portfwd_strptr = ssh->cfg.portfwd;
6536 while (*ssh->portfwd_strptr) {
6537 type = *ssh->portfwd_strptr++;
6540 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6541 if (*ssh->portfwd_strptr == ':') {
6543 * We've seen a colon in the middle of the
6544 * source port number. This means that
6545 * everything we've seen until now is the
6546 * source _address_, so we'll move it into
6547 * saddr and start sports from the beginning
6550 ssh->portfwd_strptr++;
6552 strcpy(saddr, sports);
6555 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6559 if (*ssh->portfwd_strptr == '\t')
6560 ssh->portfwd_strptr++;
6562 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6563 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6566 if (*ssh->portfwd_strptr == ':')
6567 ssh->portfwd_strptr++;
6569 while (*ssh->portfwd_strptr) {
6570 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6573 ssh->portfwd_strptr++;
6574 dport = atoi(dports);
6578 dport = net_service_lookup(dports);
6580 logeventf(ssh, "Service lookup failed for destination"
6581 " port \"%s\"", dports);
6585 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
6587 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
6589 sport = atoi(sports);
6593 sport = net_service_lookup(sports);
6595 logeventf(ssh, "Service lookup failed for source"
6596 " port \"%s\"", sports);
6599 if (sport && dport) {
6600 /* Set up a description of the source port. */
6601 static char *sportdesc;
6602 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
6603 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6604 (int)(*saddr?1:0), ":",
6605 (int)(sserv ? strlen(sports) : 0), sports,
6606 sserv, "(", sport, sserv, ")");
6608 /* Verbose description of the destination port */
6609 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6611 (int)(dserv ? strlen(dports) : 0), dports,
6612 dserv, "(", dport, dserv, ")");
6613 const char *err = pfd_addforward(host, dport,
6614 *saddr ? saddr : NULL,
6615 sport, ssh, &ssh->cfg);
6617 logeventf(ssh, "Local port %s forward to %s"
6618 " failed: %s", sportdesc, dportdesc, err);
6620 logeventf(ssh, "Local port %s forwarding to %s",
6621 sportdesc, dportdesc);
6624 } else if (type == 'D') {
6625 const char *err = pfd_addforward(NULL, -1,
6626 *saddr ? saddr : NULL,
6627 sport, ssh, &ssh->cfg);
6629 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6630 " setup failed: %s", sportdesc, err);
6632 logeventf(ssh, "Local port %s doing SOCKS"
6633 " dynamic forwarding", sportdesc);
6636 struct ssh_rportfwd *pf;
6637 pf = snew(struct ssh_rportfwd);
6638 strcpy(pf->dhost, host);
6641 if (add234(ssh->rportfwds, pf) != pf) {
6642 logeventf(ssh, "Duplicate remote port forwarding"
6643 " to %s:%d", host, dport);
6646 logeventf(ssh, "Requesting remote port %s"
6647 " forward to %s:%.*s%.*s%d%.*s",
6650 (int)(dserv ? strlen(dports) : 0), dports,
6651 dserv, "(", dport, dserv, ")");
6652 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6653 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6654 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
6656 ssh2_pkt_addstring(s->pktout, saddr);
6657 } else if (ssh->cfg.rport_acceptall) {
6658 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
6660 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
6662 ssh2_pkt_adduint32(s->pktout, sport);
6663 ssh2_pkt_send(ssh, s->pktout);
6665 crWaitUntilV(pktin);
6667 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6668 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6669 bombout(("Unexpected response to port "
6670 "forwarding request: packet type %d",
6674 logevent("Server refused this port forwarding");
6676 logevent("Remote port forwarding enabled");
6686 * Potentially enable agent forwarding.
6688 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6689 logevent("Requesting OpenSSH-style agent forwarding");
6690 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6691 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6692 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6693 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6694 ssh2_pkt_send(ssh, s->pktout);
6696 crWaitUntilV(pktin);
6698 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6699 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6700 bombout(("Unexpected response to agent forwarding request:"
6701 " packet type %d", pktin->type));
6704 logevent("Agent forwarding refused");
6706 logevent("Agent forwarding enabled");
6707 ssh->agentfwd_enabled = TRUE;
6712 * Now allocate a pty for the session.
6714 if (ssh->mainchan && !ssh->cfg.nopty) {
6715 /* Unpick the terminal-speed string. */
6716 /* XXX perhaps we should allow no speeds to be sent. */
6717 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6718 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6719 /* Build the pty request. */
6720 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6721 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6722 ssh2_pkt_addstring(s->pktout, "pty-req");
6723 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6724 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6725 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6726 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6727 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6728 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6729 ssh2_pkt_addstring_start(s->pktout);
6730 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6731 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6732 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6733 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6734 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6735 ssh2_pkt_send(ssh, s->pktout);
6736 ssh->state = SSH_STATE_INTERMED;
6738 crWaitUntilV(pktin);
6740 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6741 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6742 bombout(("Unexpected response to pty request:"
6743 " packet type %d", pktin->type));
6746 c_write_str(ssh, "Server refused to allocate pty\r\n");
6747 ssh->editing = ssh->echoing = 1;
6749 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6750 ssh->ospeed, ssh->ispeed);
6753 ssh->editing = ssh->echoing = 1;
6757 * Send environment variables.
6759 * Simplest thing here is to send all the requests at once, and
6760 * then wait for a whole bunch of successes or failures.
6762 if (ssh->mainchan && *ssh->cfg.environmt) {
6763 char *e = ssh->cfg.environmt;
6764 char *var, *varend, *val;
6770 while (*e && *e != '\t') e++;
6772 if (*e == '\t') e++;
6777 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6778 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6779 ssh2_pkt_addstring(s->pktout, "env");
6780 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6781 ssh2_pkt_addstring_start(s->pktout);
6782 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6783 ssh2_pkt_addstring(s->pktout, val);
6784 ssh2_pkt_send(ssh, s->pktout);
6789 logeventf(ssh, "Sent %d environment variables", s->num_env);
6792 s->env_left = s->num_env;
6794 while (s->env_left > 0) {
6795 crWaitUntilV(pktin);
6797 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6798 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6799 bombout(("Unexpected response to environment request:"
6800 " packet type %d", pktin->type));
6810 if (s->env_ok == s->num_env) {
6811 logevent("All environment variables successfully set");
6812 } else if (s->env_ok == 0) {
6813 logevent("All environment variables refused");
6814 c_write_str(ssh, "Server refused to set environment variables\r\n");
6816 logeventf(ssh, "%d environment variables refused",
6817 s->num_env - s->env_ok);
6818 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6823 * Start a shell or a remote command. We may have to attempt
6824 * this twice if the config data has provided a second choice
6827 if (ssh->mainchan) while (1) {
6831 if (ssh->fallback_cmd) {
6832 subsys = ssh->cfg.ssh_subsys2;
6833 cmd = ssh->cfg.remote_cmd_ptr2;
6835 subsys = ssh->cfg.ssh_subsys;
6836 cmd = ssh->cfg.remote_cmd_ptr;
6839 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6840 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6842 ssh2_pkt_addstring(s->pktout, "subsystem");
6843 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6844 ssh2_pkt_addstring(s->pktout, cmd);
6846 ssh2_pkt_addstring(s->pktout, "exec");
6847 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6848 ssh2_pkt_addstring(s->pktout, cmd);
6850 ssh2_pkt_addstring(s->pktout, "shell");
6851 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6853 ssh2_pkt_send(ssh, s->pktout);
6855 crWaitUntilV(pktin);
6857 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6858 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6859 bombout(("Unexpected response to shell/command request:"
6860 " packet type %d", pktin->type));
6864 * We failed to start the command. If this is the
6865 * fallback command, we really are finished; if it's
6866 * not, and if the fallback command exists, try falling
6867 * back to it before complaining.
6869 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6870 logevent("Primary command failed; attempting fallback");
6871 ssh->fallback_cmd = TRUE;
6874 bombout(("Server refused to start a shell/command"));
6877 logevent("Started a shell/command");
6882 ssh->state = SSH_STATE_SESSION;
6883 if (ssh->size_needed)
6884 ssh_size(ssh, ssh->term_width, ssh->term_height);
6885 if (ssh->eof_needed)
6886 ssh_special(ssh, TS_EOF);
6892 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6897 s->try_send = FALSE;
6901 * _All_ the connection-layer packets we expect to
6902 * receive are now handled by the dispatch table.
6903 * Anything that reaches here must be bogus.
6906 bombout(("Strange packet received: type %d", pktin->type));
6908 } else if (ssh->mainchan) {
6910 * We have spare data. Add it to the channel buffer.
6912 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6917 struct ssh_channel *c;
6919 * Try to send data on all channels if we can.
6921 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6924 continue; /* don't send on closing channels */
6925 bufsize = ssh2_try_send(c);
6928 case CHAN_MAINSESSION:
6929 /* stdin need not receive an unthrottle
6930 * notification since it will be polled */
6933 x11_unthrottle(c->u.x11.s);
6936 /* agent sockets are request/response and need no
6937 * buffer management */
6940 pfd_unthrottle(c->u.pfd.s);
6952 * Handlers for SSH2 messages that might arrive at any moment.
6954 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6956 /* log reason code in disconnect message */
6958 int nowlen, reason, msglen;
6960 reason = ssh_pkt_getuint32(pktin);
6961 ssh_pkt_getstring(pktin, &msg, &msglen);
6963 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6964 buf = dupprintf("Received disconnect message (%s)",
6965 ssh2_disconnect_reasons[reason]);
6967 buf = dupprintf("Received disconnect message (unknown"
6968 " type %d)", reason);
6972 buf = dupprintf("Disconnection message text: %n%.*s",
6973 &nowlen, msglen, msg);
6975 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6977 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6978 ssh2_disconnect_reasons[reason] : "unknown",
6983 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6985 /* log the debug message */
6990 /* XXX maybe we should actually take notice of this */
6991 always_display = ssh2_pkt_getbool(pktin);
6992 ssh_pkt_getstring(pktin, &msg, &msglen);
6994 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6999 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7001 struct Packet *pktout;
7002 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7003 ssh2_pkt_adduint32(pktout, pktin->sequence);
7005 * UNIMPLEMENTED messages MUST appear in the same order as the
7006 * messages they respond to. Hence, never queue them.
7008 ssh2_pkt_send_noqueue(ssh, pktout);
7012 * Handle the top-level SSH2 protocol.
7014 static void ssh2_protocol_setup(Ssh ssh)
7019 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7021 for (i = 0; i < 256; i++)
7022 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7025 * Any message we actually understand, we set to NULL so that
7026 * the coroutines will get it.
7028 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7029 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7030 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7031 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7032 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7033 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7034 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7035 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7036 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7037 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7038 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7039 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7040 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7041 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7042 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7043 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7044 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7045 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7046 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7047 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7048 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7049 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7050 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7051 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7052 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7053 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7054 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7056 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7057 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7058 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7059 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7060 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7063 * These special message types we install handlers for.
7065 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7066 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7067 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7070 static void ssh2_timer(void *ctx, long now)
7074 if (!ssh->kex_in_progress &&
7075 now - ssh->next_rekey >= 0) {
7076 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7081 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7082 struct Packet *pktin)
7084 if (ssh->state == SSH_STATE_CLOSED)
7088 ssh->incoming_data_size += pktin->encrypted_len;
7089 if (!ssh->kex_in_progress &&
7090 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7091 do_ssh2_transport(ssh, "Initiating key re-exchange "
7092 "(too much data received)", -1, NULL);
7095 if (pktin && ssh->packet_dispatch[pktin->type]) {
7096 ssh->packet_dispatch[pktin->type](ssh, pktin);
7100 if (!ssh->protocol_initial_phase_done ||
7101 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7102 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7103 !ssh->protocol_initial_phase_done) {
7104 ssh->protocol_initial_phase_done = TRUE;
7106 * Allow authconn to initialise itself.
7108 do_ssh2_authconn(ssh, NULL, 0, NULL);
7111 do_ssh2_authconn(ssh, in, inlen, pktin);
7116 * Called to set up the connection.
7118 * Returns an error message, or NULL on success.
7120 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7122 char *host, int port, char **realhost, int nodelay,
7128 ssh = snew(struct ssh_tag);
7129 ssh->cfg = *cfg; /* STRUCTURE COPY */
7130 ssh->version = 0; /* when not ready yet */
7133 ssh->v1_cipher_ctx = NULL;
7134 ssh->crcda_ctx = NULL;
7135 ssh->cscipher = NULL;
7136 ssh->cs_cipher_ctx = NULL;
7137 ssh->sccipher = NULL;
7138 ssh->sc_cipher_ctx = NULL;
7140 ssh->cs_mac_ctx = NULL;
7142 ssh->sc_mac_ctx = NULL;
7144 ssh->cs_comp_ctx = NULL;
7146 ssh->sc_comp_ctx = NULL;
7148 ssh->kex_ctx = NULL;
7149 ssh->hostkey = NULL;
7151 ssh->state = SSH_STATE_PREPACKET;
7152 ssh->size_needed = FALSE;
7153 ssh->eof_needed = FALSE;
7156 ssh->deferred_send_data = NULL;
7157 ssh->deferred_len = 0;
7158 ssh->deferred_size = 0;
7159 ssh->fallback_cmd = 0;
7161 ssh->x11auth = NULL;
7162 ssh->v1_compressing = FALSE;
7163 ssh->v2_outgoing_sequence = 0;
7164 ssh->ssh1_rdpkt_crstate = 0;
7165 ssh->ssh2_rdpkt_crstate = 0;
7166 ssh->do_ssh_init_crstate = 0;
7167 ssh->ssh_gotdata_crstate = 0;
7168 ssh->do_ssh1_connection_crstate = 0;
7169 ssh->do_ssh1_login_crstate = 0;
7170 ssh->do_ssh2_transport_crstate = 0;
7171 ssh->do_ssh2_authconn_crstate = 0;
7172 ssh->do_ssh_init_state = NULL;
7173 ssh->do_ssh1_login_state = NULL;
7174 ssh->do_ssh2_transport_state = NULL;
7175 ssh->do_ssh2_authconn_state = NULL;
7176 ssh->mainchan = NULL;
7177 ssh->throttled_all = 0;
7178 ssh->v1_stdout_throttling = 0;
7180 ssh->queuelen = ssh->queuesize = 0;
7181 ssh->queueing = FALSE;
7183 *backend_handle = ssh;
7186 if (crypto_startup() == 0)
7187 return "Microsoft high encryption pack not installed!";
7190 ssh->frontend = frontend_handle;
7191 ssh->term_width = ssh->cfg.width;
7192 ssh->term_height = ssh->cfg.height;
7194 ssh->channels = NULL;
7195 ssh->rportfwds = NULL;
7200 ssh->v1_throttle_count = 0;
7201 ssh->overall_bufsize = 0;
7202 ssh->fallback_cmd = 0;
7204 ssh->protocol = NULL;
7206 ssh->protocol_initial_phase_done = FALSE;
7210 ssh->incoming_data_size = ssh->outgoing_data_size =
7211 ssh->deferred_data_size = 0L;
7212 ssh->kex_in_progress = FALSE;
7214 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7223 static void ssh_free(void *handle)
7225 Ssh ssh = (Ssh) handle;
7226 struct ssh_channel *c;
7227 struct ssh_rportfwd *pf;
7229 if (ssh->v1_cipher_ctx)
7230 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7231 if (ssh->cs_cipher_ctx)
7232 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7233 if (ssh->sc_cipher_ctx)
7234 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7235 if (ssh->cs_mac_ctx)
7236 ssh->csmac->free_context(ssh->cs_mac_ctx);
7237 if (ssh->sc_mac_ctx)
7238 ssh->scmac->free_context(ssh->sc_mac_ctx);
7239 if (ssh->cs_comp_ctx) {
7241 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7243 zlib_compress_cleanup(ssh->cs_comp_ctx);
7245 if (ssh->sc_comp_ctx) {
7247 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7249 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7252 dh_cleanup(ssh->kex_ctx);
7253 sfree(ssh->savedhost);
7255 while (ssh->queuelen-- > 0)
7256 ssh_free_packet(ssh->queue[ssh->queuelen]);
7259 if (ssh->channels) {
7260 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7263 if (c->u.x11.s != NULL)
7264 x11_close(c->u.x11.s);
7267 if (c->u.pfd.s != NULL)
7268 pfd_close(c->u.pfd.s);
7273 freetree234(ssh->channels);
7274 ssh->channels = NULL;
7277 if (ssh->rportfwds) {
7278 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7280 freetree234(ssh->rportfwds);
7281 ssh->rportfwds = NULL;
7283 sfree(ssh->deferred_send_data);
7285 x11_free_auth(ssh->x11auth);
7286 sfree(ssh->do_ssh_init_state);
7287 sfree(ssh->do_ssh1_login_state);
7288 sfree(ssh->do_ssh2_transport_state);
7289 sfree(ssh->do_ssh2_authconn_state);
7290 if (ssh->crcda_ctx) {
7291 crcda_free_context(ssh->crcda_ctx);
7292 ssh->crcda_ctx = NULL;
7296 expire_timer_context(ssh);
7298 pinger_free(ssh->pinger);
7305 * Reconfigure the SSH backend.
7307 * Currently, this function does nothing very useful. In future,
7308 * however, we could do some handy things with it. For example, we
7309 * could make the port forwarding configurer active in the Change
7310 * Settings box, and this routine could close down existing
7311 * forwardings and open up new ones in response to changes.
7313 static void ssh_reconfig(void *handle, Config *cfg)
7315 Ssh ssh = (Ssh) handle;
7316 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7317 ssh->cfg = *cfg; /* STRUCTURE COPY */
7321 * Called to send data down the Telnet connection.
7323 static int ssh_send(void *handle, char *buf, int len)
7325 Ssh ssh = (Ssh) handle;
7327 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7330 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7332 return ssh_sendbuffer(ssh);
7336 * Called to query the current amount of buffered stdin data.
7338 static int ssh_sendbuffer(void *handle)
7340 Ssh ssh = (Ssh) handle;
7343 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7347 * If the SSH socket itself has backed up, add the total backup
7348 * size on that to any individual buffer on the stdin channel.
7351 if (ssh->throttled_all)
7352 override_value = ssh->overall_bufsize;
7354 if (ssh->version == 1) {
7355 return override_value;
7356 } else if (ssh->version == 2) {
7357 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7358 return override_value;
7360 return (override_value +
7361 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7368 * Called to set the size of the window from SSH's POV.
7370 static void ssh_size(void *handle, int width, int height)
7372 Ssh ssh = (Ssh) handle;
7373 struct Packet *pktout;
7375 ssh->term_width = width;
7376 ssh->term_height = height;
7378 switch (ssh->state) {
7379 case SSH_STATE_BEFORE_SIZE:
7380 case SSH_STATE_PREPACKET:
7381 case SSH_STATE_CLOSED:
7382 break; /* do nothing */
7383 case SSH_STATE_INTERMED:
7384 ssh->size_needed = TRUE; /* buffer for later */
7386 case SSH_STATE_SESSION:
7387 if (!ssh->cfg.nopty) {
7388 if (ssh->version == 1) {
7389 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7390 PKT_INT, ssh->term_height,
7391 PKT_INT, ssh->term_width,
7392 PKT_INT, 0, PKT_INT, 0, PKT_END);
7393 } else if (ssh->mainchan) {
7394 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7395 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7396 ssh2_pkt_addstring(pktout, "window-change");
7397 ssh2_pkt_addbool(pktout, 0);
7398 ssh2_pkt_adduint32(pktout, ssh->term_width);
7399 ssh2_pkt_adduint32(pktout, ssh->term_height);
7400 ssh2_pkt_adduint32(pktout, 0);
7401 ssh2_pkt_adduint32(pktout, 0);
7402 ssh2_pkt_send(ssh, pktout);
7410 * Return a list of the special codes that make sense in this
7413 static const struct telnet_special *ssh_get_specials(void *handle)
7415 static const struct telnet_special ssh1_ignore_special[] = {
7416 {"IGNORE message", TS_NOP}
7418 static const struct telnet_special ssh2_transport_specials[] = {
7419 {"IGNORE message", TS_NOP},
7420 {"Repeat key exchange", TS_REKEY},
7422 static const struct telnet_special ssh2_session_specials[] = {
7425 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7426 * They include all the ISO C signals, but are a subset of the POSIX
7427 * required signals. */
7428 {"SIGINT (Interrupt)", TS_SIGINT},
7429 {"SIGTERM (Terminate)", TS_SIGTERM},
7430 {"SIGKILL (Kill)", TS_SIGKILL},
7431 {"SIGQUIT (Quit)", TS_SIGQUIT},
7432 {"SIGHUP (Hangup)", TS_SIGHUP},
7433 {"More signals", TS_SUBMENU},
7434 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7435 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7436 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7437 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7440 static const struct telnet_special specials_end[] = {
7443 /* XXX review this length for any changes: */
7444 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7445 lenof(ssh2_session_specials) +
7446 lenof(specials_end)];
7447 Ssh ssh = (Ssh) handle;
7449 #define ADD_SPECIALS(name) \
7451 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7452 memcpy(&ssh_specials[i], name, sizeof name); \
7456 if (ssh->version == 1) {
7457 /* Don't bother offering IGNORE if we've decided the remote
7458 * won't cope with it, since we wouldn't bother sending it if
7460 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7461 ADD_SPECIALS(ssh1_ignore_special);
7462 } else if (ssh->version == 2) {
7463 ADD_SPECIALS(ssh2_transport_specials);
7465 ADD_SPECIALS(ssh2_session_specials);
7466 } /* else we're not ready yet */
7469 ADD_SPECIALS(specials_end);
7470 return ssh_specials;
7478 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7479 * can send an EOF and collect resulting output (e.g. `plink
7482 static void ssh_special(void *handle, Telnet_Special code)
7484 Ssh ssh = (Ssh) handle;
7485 struct Packet *pktout;
7487 if (code == TS_EOF) {
7488 if (ssh->state != SSH_STATE_SESSION) {
7490 * Buffer the EOF in case we are pre-SESSION, so we can
7491 * send it as soon as we reach SESSION.
7494 ssh->eof_needed = TRUE;
7497 if (ssh->version == 1) {
7498 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7499 } else if (ssh->mainchan) {
7500 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7501 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7502 ssh2_pkt_send(ssh, pktout);
7504 logevent("Sent EOF message");
7505 } else if (code == TS_PING || code == TS_NOP) {
7506 if (ssh->state == SSH_STATE_CLOSED
7507 || ssh->state == SSH_STATE_PREPACKET) return;
7508 if (ssh->version == 1) {
7509 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7510 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7512 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7513 ssh2_pkt_addstring_start(pktout);
7514 ssh2_pkt_send_noqueue(ssh, pktout);
7516 } else if (code == TS_REKEY) {
7517 if (!ssh->kex_in_progress && ssh->version == 2) {
7518 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7519 " user request", -1, NULL);
7521 } else if (code == TS_BRK) {
7522 if (ssh->state == SSH_STATE_CLOSED
7523 || ssh->state == SSH_STATE_PREPACKET) return;
7524 if (ssh->version == 1) {
7525 logevent("Unable to send BREAK signal in SSH1");
7526 } else if (ssh->mainchan) {
7527 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7528 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7529 ssh2_pkt_addstring(pktout, "break");
7530 ssh2_pkt_addbool(pktout, 0);
7531 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7532 ssh2_pkt_send(ssh, pktout);
7535 /* Is is a POSIX signal? */
7536 char *signame = NULL;
7537 if (code == TS_SIGABRT) signame = "ABRT";
7538 if (code == TS_SIGALRM) signame = "ALRM";
7539 if (code == TS_SIGFPE) signame = "FPE";
7540 if (code == TS_SIGHUP) signame = "HUP";
7541 if (code == TS_SIGILL) signame = "ILL";
7542 if (code == TS_SIGINT) signame = "INT";
7543 if (code == TS_SIGKILL) signame = "KILL";
7544 if (code == TS_SIGPIPE) signame = "PIPE";
7545 if (code == TS_SIGQUIT) signame = "QUIT";
7546 if (code == TS_SIGSEGV) signame = "SEGV";
7547 if (code == TS_SIGTERM) signame = "TERM";
7548 if (code == TS_SIGUSR1) signame = "USR1";
7549 if (code == TS_SIGUSR2) signame = "USR2";
7550 /* The SSH-2 protocol does in principle support arbitrary named
7551 * signals, including signame@domain, but we don't support those. */
7553 /* It's a signal. */
7554 if (ssh->version == 2 && ssh->mainchan) {
7555 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7556 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7557 ssh2_pkt_addstring(pktout, "signal");
7558 ssh2_pkt_addbool(pktout, 0);
7559 ssh2_pkt_addstring(pktout, signame);
7560 ssh2_pkt_send(ssh, pktout);
7561 logeventf(ssh, "Sent signal SIG%s", signame);
7564 /* Never heard of it. Do nothing */
7569 void *new_sock_channel(void *handle, Socket s)
7571 Ssh ssh = (Ssh) handle;
7572 struct ssh_channel *c;
7573 c = snew(struct ssh_channel);
7577 c->remoteid = -1; /* to be set when open confirmed */
7578 c->localid = alloc_channel_id(ssh);
7580 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7582 bufchain_init(&c->v.v2.outbuffer);
7583 add234(ssh->channels, c);
7589 * This is called when stdout/stderr (the entity to which
7590 * from_backend sends data) manages to clear some backlog.
7592 static void ssh_unthrottle(void *handle, int bufsize)
7594 Ssh ssh = (Ssh) handle;
7595 if (ssh->version == 1) {
7596 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7597 ssh->v1_stdout_throttling = 0;
7598 ssh1_throttle(ssh, -1);
7601 if (ssh->mainchan && ssh->mainchan->closes == 0)
7602 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7606 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7608 struct ssh_channel *c = (struct ssh_channel *)channel;
7610 struct Packet *pktout;
7612 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7614 if (ssh->version == 1) {
7615 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7616 PKT_INT, c->localid,
7619 //PKT_STR, <org:orgport>,
7622 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7623 ssh2_pkt_addstring(pktout, "direct-tcpip");
7624 ssh2_pkt_adduint32(pktout, c->localid);
7625 c->v.v2.locwindow = OUR_V2_WINSIZE;
7626 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7627 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7628 ssh2_pkt_addstring(pktout, hostname);
7629 ssh2_pkt_adduint32(pktout, port);
7631 * We make up values for the originator data; partly it's
7632 * too much hassle to keep track, and partly I'm not
7633 * convinced the server should be told details like that
7634 * about my local network configuration.
7636 ssh2_pkt_addstring(pktout, "client-side-connection");
7637 ssh2_pkt_adduint32(pktout, 0);
7638 ssh2_pkt_send(ssh, pktout);
7642 static Socket ssh_socket(void *handle)
7644 Ssh ssh = (Ssh) handle;
7648 static int ssh_sendok(void *handle)
7650 Ssh ssh = (Ssh) handle;
7651 return ssh->send_ok;
7654 static int ssh_ldisc(void *handle, int option)
7656 Ssh ssh = (Ssh) handle;
7657 if (option == LD_ECHO)
7658 return ssh->echoing;
7659 if (option == LD_EDIT)
7660 return ssh->editing;
7664 static void ssh_provide_ldisc(void *handle, void *ldisc)
7666 Ssh ssh = (Ssh) handle;
7670 static void ssh_provide_logctx(void *handle, void *logctx)
7672 Ssh ssh = (Ssh) handle;
7673 ssh->logctx = logctx;
7676 static int ssh_return_exitcode(void *handle)
7678 Ssh ssh = (Ssh) handle;
7682 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7686 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7687 * that fails. This variable is the means by which scp.c can reach
7688 * into the SSH code and find out which one it got.
7690 extern int ssh_fallback_cmd(void *handle)
7692 Ssh ssh = (Ssh) handle;
7693 return ssh->fallback_cmd;
7696 Backend ssh_backend = {
7706 ssh_return_exitcode,