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 is indexed by destination
498 * host:port pair, whereas in SSH 2 it is indexed by source port.
500 struct ssh_rportfwd {
501 unsigned sport, dport;
509 unsigned long sequence;
514 long encrypted_len; /* for SSH2 total-size counting */
517 * State associated with packet logging
521 struct logblank_t *blanks;
524 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
525 struct Packet *pktin);
526 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
527 struct Packet *pktin);
528 static void ssh1_protocol_setup(Ssh ssh);
529 static void ssh2_protocol_setup(Ssh ssh);
530 static void ssh_size(void *handle, int width, int height);
531 static void ssh_special(void *handle, Telnet_Special);
532 static int ssh2_try_send(struct ssh_channel *c);
533 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
534 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
535 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
536 static int ssh_sendbuffer(void *handle);
537 static void ssh_do_close(Ssh ssh);
538 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
539 static int ssh2_pkt_getbool(struct Packet *pkt);
540 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
541 static void ssh2_timer(void *ctx, long now);
542 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
543 struct Packet *pktin);
545 struct rdpkt1_state_tag {
546 long len, pad, biglen, to_read;
547 unsigned long realcrc, gotcrc;
551 struct Packet *pktin;
554 struct rdpkt2_state_tag {
555 long len, pad, payload, packetlen, maclen;
558 unsigned long incoming_sequence;
559 struct Packet *pktin;
562 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
563 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
565 struct queued_handler;
566 struct queued_handler {
568 chandler_fn_t handler;
570 struct queued_handler *next;
574 const struct plug_function_table *fn;
575 /* the above field _must_ be first in the structure */
577 SHA_State exhash, exhashbase;
584 unsigned char session_key[32];
586 int v1_remote_protoflags;
587 int v1_local_protoflags;
588 int agentfwd_enabled;
591 const struct ssh_cipher *cipher;
594 const struct ssh2_cipher *cscipher, *sccipher;
595 void *cs_cipher_ctx, *sc_cipher_ctx;
596 const struct ssh_mac *csmac, *scmac;
597 void *cs_mac_ctx, *sc_mac_ctx;
598 const struct ssh_compress *cscomp, *sccomp;
599 void *cs_comp_ctx, *sc_comp_ctx;
600 const struct ssh_kex *kex;
601 const struct ssh_signkey *hostkey;
602 unsigned char v2_session_id[20];
608 int echoing, editing;
612 int ospeed, ispeed; /* temporaries */
613 int term_width, term_height;
615 tree234 *channels; /* indexed by local id */
616 struct ssh_channel *mainchan; /* primary session channel */
623 SSH_STATE_BEFORE_SIZE,
629 int size_needed, eof_needed;
631 struct Packet **queue;
632 int queuelen, queuesize;
634 unsigned char *deferred_send_data;
635 int deferred_len, deferred_size;
638 * Gross hack: pscp will try to start SFTP but fall back to
639 * scp1 if that fails. This variable is the means by which
640 * scp.c can reach into the SSH code and find out which one it
646 * Used for username and password input.
648 char *userpass_input_buffer;
649 int userpass_input_buflen;
650 int userpass_input_bufpos;
651 int userpass_input_echo;
658 int v1_throttle_count;
661 int v1_stdout_throttling;
662 int v2_outgoing_sequence;
664 int ssh1_rdpkt_crstate;
665 int ssh2_rdpkt_crstate;
666 int do_ssh_init_crstate;
667 int ssh_gotdata_crstate;
668 int do_ssh1_login_crstate;
669 int do_ssh1_connection_crstate;
670 int do_ssh2_transport_crstate;
671 int do_ssh2_authconn_crstate;
673 void *do_ssh_init_state;
674 void *do_ssh1_login_state;
675 void *do_ssh2_transport_state;
676 void *do_ssh2_authconn_state;
678 struct rdpkt1_state_tag rdpkt1_state;
679 struct rdpkt2_state_tag rdpkt2_state;
681 /* ssh1 and ssh2 use this for different things, but both use it */
682 int protocol_initial_phase_done;
684 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
686 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
689 * We maintain a full _copy_ of a Config structure here, not
690 * merely a pointer to it. That way, when we're passed a new
691 * one for reconfiguration, we can check the differences and
692 * potentially reconfigure port forwardings etc in mid-session.
697 * Used to transfer data back from async agent callbacks.
699 void *agent_response;
700 int agent_response_len;
703 * Dispatch table for packet types that we may have to deal
706 handler_fn_t packet_dispatch[256];
709 * Queues of one-off handler functions for success/failure
710 * indications from a request.
712 struct queued_handler *qhead, *qtail;
715 * This module deals with sending keepalives.
720 * Track incoming and outgoing data sizes and time, for
723 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
724 unsigned long max_data_size;
729 #define logevent(s) logevent(ssh->frontend, s)
731 /* logevent, only printf-formatted. */
732 static void logeventf(Ssh ssh, const char *fmt, ...)
738 buf = dupvprintf(fmt, ap);
744 #define bombout(msg) \
746 char *text = dupprintf msg; \
749 connection_fatal(ssh->frontend, "%s", text); \
753 /* Functions to leave bits out of the SSH packet log file. */
755 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
757 if (ssh->cfg.logomitpass)
758 pkt->logmode = blanktype;
761 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
763 if (ssh->cfg.logomitdata)
764 pkt->logmode = blanktype;
767 static void end_log_omission(Ssh ssh, struct Packet *pkt)
769 pkt->logmode = PKTLOG_EMIT;
772 static int ssh_channelcmp(void *av, void *bv)
774 struct ssh_channel *a = (struct ssh_channel *) av;
775 struct ssh_channel *b = (struct ssh_channel *) bv;
776 if (a->localid < b->localid)
778 if (a->localid > b->localid)
782 static int ssh_channelfind(void *av, void *bv)
784 unsigned *a = (unsigned *) av;
785 struct ssh_channel *b = (struct ssh_channel *) bv;
793 static int ssh_rportcmp_ssh1(void *av, void *bv)
795 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
796 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
798 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
799 return i < 0 ? -1 : +1;
800 if (a->dport > b->dport)
802 if (a->dport < b->dport)
807 static int ssh_rportcmp_ssh2(void *av, void *bv)
809 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
810 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
812 if (a->sport > b->sport)
814 if (a->sport < b->sport)
819 static int alloc_channel_id(Ssh ssh)
821 const unsigned CHANNEL_NUMBER_OFFSET = 256;
822 unsigned low, high, mid;
824 struct ssh_channel *c;
827 * First-fit allocation of channel numbers: always pick the
828 * lowest unused one. To do this, binary-search using the
829 * counted B-tree to find the largest channel ID which is in a
830 * contiguous sequence from the beginning. (Precisely
831 * everything in that sequence must have ID equal to its tree
832 * index plus CHANNEL_NUMBER_OFFSET.)
834 tsize = count234(ssh->channels);
838 while (high - low > 1) {
839 mid = (high + low) / 2;
840 c = index234(ssh->channels, mid);
841 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
842 low = mid; /* this one is fine */
844 high = mid; /* this one is past it */
847 * Now low points to either -1, or the tree index of the
848 * largest ID in the initial sequence.
851 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
852 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
854 return low + 1 + CHANNEL_NUMBER_OFFSET;
857 static void c_write(Ssh ssh, const char *buf, int len)
859 if ((flags & FLAG_STDERR)) {
861 for (i = 0; i < len; i++)
863 fputc(buf[i], stderr);
866 from_backend(ssh->frontend, 1, buf, len);
869 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
872 for (i = 0; i < len; i++) {
874 c_write(ssh, "\r\n", 2);
875 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
876 c_write(ssh, buf + i, 1);
880 static void c_write_str(Ssh ssh, const char *buf)
882 c_write(ssh, buf, strlen(buf));
885 static void ssh_free_packet(struct Packet *pkt)
890 static struct Packet *ssh_new_packet(void)
892 struct Packet *pkt = snew(struct Packet);
896 pkt->logmode = PKTLOG_EMIT;
904 * Collect incoming data in the incoming packet buffer.
905 * Decipher and verify the packet when it is completely read.
906 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
907 * Update the *data and *datalen variables.
908 * Return a Packet structure when a packet is completed.
910 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
912 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
914 crBegin(ssh->ssh1_rdpkt_crstate);
916 st->pktin = ssh_new_packet();
919 st->pktin->length = 0;
921 for (st->i = st->len = 0; st->i < 4; st->i++) {
922 while ((*datalen) == 0)
924 st->len = (st->len << 8) + **data;
925 (*data)++, (*datalen)--;
928 st->pad = 8 - (st->len % 8);
929 st->biglen = st->len + st->pad;
930 st->pktin->length = st->len - 5;
932 if (st->biglen < 0) {
933 bombout(("Extremely large packet length from server suggests"
934 " data stream corruption"));
935 ssh_free_packet(st->pktin);
939 st->pktin->maxlen = st->biglen;
940 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
942 st->to_read = st->biglen;
943 st->p = st->pktin->data;
944 while (st->to_read > 0) {
945 st->chunk = st->to_read;
946 while ((*datalen) == 0)
948 if (st->chunk > (*datalen))
949 st->chunk = (*datalen);
950 memcpy(st->p, *data, st->chunk);
952 *datalen -= st->chunk;
954 st->to_read -= st->chunk;
957 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
959 bombout(("Network attack (CRC compensation) detected!"));
960 ssh_free_packet(st->pktin);
965 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
967 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
968 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
969 if (st->gotcrc != st->realcrc) {
970 bombout(("Incorrect CRC received on packet"));
971 ssh_free_packet(st->pktin);
975 st->pktin->body = st->pktin->data + st->pad + 1;
976 st->pktin->savedpos = 0;
978 if (ssh->v1_compressing) {
979 unsigned char *decompblk;
981 if (!zlib_decompress_block(ssh->sc_comp_ctx,
982 st->pktin->body - 1, st->pktin->length + 1,
983 &decompblk, &decomplen)) {
984 bombout(("Zlib decompression encountered invalid data"));
985 ssh_free_packet(st->pktin);
989 if (st->pktin->maxlen < st->pad + decomplen) {
990 st->pktin->maxlen = st->pad + decomplen;
991 st->pktin->data = sresize(st->pktin->data,
992 st->pktin->maxlen + APIEXTRA,
994 st->pktin->body = st->pktin->data + st->pad + 1;
997 memcpy(st->pktin->body - 1, decompblk, decomplen);
999 st->pktin->length = decomplen - 1;
1002 st->pktin->type = st->pktin->body[-1];
1005 * Log incoming packet, possibly omitting sensitive fields.
1009 struct logblank_t blank;
1010 if (ssh->cfg.logomitdata) {
1011 int do_blank = FALSE, blank_prefix = 0;
1012 /* "Session data" packets - omit the data field */
1013 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1014 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1015 do_blank = TRUE; blank_prefix = 0;
1016 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1017 do_blank = TRUE; blank_prefix = 4;
1020 blank.offset = blank_prefix;
1021 blank.len = st->pktin->length;
1022 blank.type = PKTLOG_OMIT;
1026 log_packet(ssh->logctx,
1027 PKT_INCOMING, st->pktin->type,
1028 ssh1_pkt_type(st->pktin->type),
1029 st->pktin->body, st->pktin->length,
1033 crFinish(st->pktin);
1036 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1038 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1040 crBegin(ssh->ssh2_rdpkt_crstate);
1042 st->pktin = ssh_new_packet();
1044 st->pktin->type = 0;
1045 st->pktin->length = 0;
1047 st->cipherblk = ssh->sccipher->blksize;
1050 if (st->cipherblk < 8)
1053 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1056 * Acquire and decrypt the first block of the packet. This will
1057 * contain the length and padding details.
1059 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1060 while ((*datalen) == 0)
1062 st->pktin->data[st->i] = *(*data)++;
1067 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1068 st->pktin->data, st->cipherblk);
1071 * Now get the length and padding figures.
1073 st->len = GET_32BIT(st->pktin->data);
1074 st->pad = st->pktin->data[4];
1077 * _Completely_ silly lengths should be stomped on before they
1078 * do us any more damage.
1080 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1081 bombout(("Incoming packet was garbled on decryption"));
1082 ssh_free_packet(st->pktin);
1087 * This enables us to deduce the payload length.
1089 st->payload = st->len - st->pad - 1;
1091 st->pktin->length = st->payload + 5;
1094 * So now we can work out the total packet length.
1096 st->packetlen = st->len + 4;
1097 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1100 * Allocate memory for the rest of the packet.
1102 st->pktin->maxlen = st->packetlen + st->maclen;
1103 st->pktin->data = sresize(st->pktin->data,
1104 st->pktin->maxlen + APIEXTRA,
1108 * Read and decrypt the remainder of the packet.
1110 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1112 while ((*datalen) == 0)
1114 st->pktin->data[st->i] = *(*data)++;
1117 /* Decrypt everything _except_ the MAC. */
1119 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1120 st->pktin->data + st->cipherblk,
1121 st->packetlen - st->cipherblk);
1123 st->pktin->encrypted_len = st->packetlen;
1129 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1130 st->incoming_sequence)) {
1131 bombout(("Incorrect MAC received on packet"));
1132 ssh_free_packet(st->pktin);
1136 st->pktin->sequence = st->incoming_sequence++;
1139 * Decompress packet payload.
1142 unsigned char *newpayload;
1145 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1146 st->pktin->data + 5, st->pktin->length - 5,
1147 &newpayload, &newlen)) {
1148 if (st->pktin->maxlen < newlen + 5) {
1149 st->pktin->maxlen = newlen + 5;
1150 st->pktin->data = sresize(st->pktin->data,
1151 st->pktin->maxlen + APIEXTRA,
1154 st->pktin->length = 5 + newlen;
1155 memcpy(st->pktin->data + 5, newpayload, newlen);
1160 st->pktin->savedpos = 6;
1161 st->pktin->body = st->pktin->data;
1162 st->pktin->type = st->pktin->data[5];
1165 * Log incoming packet, possibly omitting sensitive fields.
1169 struct logblank_t blank;
1170 if (ssh->cfg.logomitdata) {
1171 int do_blank = FALSE, blank_prefix = 0;
1172 /* "Session data" packets - omit the data field */
1173 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1174 do_blank = TRUE; blank_prefix = 4;
1175 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1176 do_blank = TRUE; blank_prefix = 8;
1179 blank.offset = blank_prefix;
1180 blank.len = (st->pktin->length-6) - blank_prefix;
1181 blank.type = PKTLOG_OMIT;
1185 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1186 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1187 st->pktin->data+6, st->pktin->length-6,
1191 crFinish(st->pktin);
1194 static void ssh1_pktout_size(struct Packet *pkt, int len)
1198 len += 5; /* type and CRC */
1199 pad = 8 - (len % 8);
1202 pkt->length = len - 5;
1203 if (pkt->maxlen < biglen) {
1204 pkt->maxlen = biglen;
1205 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1207 pkt->body = pkt->data + 4 + pad + 1;
1210 static struct Packet *s_wrpkt_start(int type, int len)
1212 struct Packet *pkt = ssh_new_packet();
1213 ssh1_pktout_size(pkt, len);
1215 /* Initialise log omission state */
1221 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1227 * XXX various versions of SC (including 8.8.4) screw up the
1228 * register allocation in this function and use the same register
1229 * (D6) for len and as a temporary, with predictable results. The
1230 * following sledgehammer prevents this.
1236 pkt->body[-1] = pkt->type;
1239 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1240 ssh1_pkt_type(pkt->type),
1241 pkt->body, pkt->length,
1242 pkt->nblanks, pkt->blanks);
1243 sfree(pkt->blanks); pkt->blanks = NULL;
1246 if (ssh->v1_compressing) {
1247 unsigned char *compblk;
1249 zlib_compress_block(ssh->cs_comp_ctx,
1250 pkt->body - 1, pkt->length + 1,
1251 &compblk, &complen);
1252 ssh1_pktout_size(pkt, complen - 1);
1253 memcpy(pkt->body - 1, compblk, complen);
1257 len = pkt->length + 5; /* type and CRC */
1258 pad = 8 - (len % 8);
1261 for (i = 0; i < pad; i++)
1262 pkt->data[i + 4] = random_byte();
1263 crc = crc32_compute(pkt->data + 4, biglen - 4);
1264 PUT_32BIT(pkt->data + biglen, crc);
1265 PUT_32BIT(pkt->data, len);
1268 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1273 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1276 len = s_wrpkt_prepare(ssh, pkt);
1277 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1278 if (backlog > SSH_MAX_BACKLOG)
1279 ssh_throttle_all(ssh, 1, backlog);
1282 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1285 len = s_wrpkt_prepare(ssh, pkt);
1286 if (ssh->deferred_len + len > ssh->deferred_size) {
1287 ssh->deferred_size = ssh->deferred_len + len + 128;
1288 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1292 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1293 ssh->deferred_len += len;
1297 * Construct a packet with the specified contents.
1299 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1300 va_list ap1, va_list ap2)
1302 unsigned char *p, *argp, argchar;
1303 unsigned long argint;
1304 int pktlen, argtype, arglen;
1309 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1312 (void) va_arg(ap1, int);
1316 (void) va_arg(ap1, int);
1320 (void) va_arg(ap1, unsigned char *);
1321 arglen = va_arg(ap1, int);
1325 argp = va_arg(ap1, unsigned char *);
1326 arglen = strlen((char *)argp);
1327 pktlen += 4 + arglen;
1330 bn = va_arg(ap1, Bignum);
1331 pktlen += ssh1_bignum_length(bn);
1336 /* ignore this pass */
1343 pkt = s_wrpkt_start(pkttype, pktlen);
1346 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1347 int offset = p - pkt->body, len = 0;
1349 /* Actual fields in the packet */
1351 argint = va_arg(ap2, int);
1352 PUT_32BIT(p, argint);
1356 argchar = (unsigned char) va_arg(ap2, int);
1361 argp = va_arg(ap2, unsigned char *);
1362 arglen = va_arg(ap2, int);
1363 memcpy(p, argp, arglen);
1367 argp = va_arg(ap2, unsigned char *);
1368 arglen = strlen((char *)argp);
1369 PUT_32BIT(p, arglen);
1370 memcpy(p + 4, argp, arglen);
1374 bn = va_arg(ap2, Bignum);
1375 len = ssh1_write_bignum(p, bn);
1377 /* Tokens for modifications to packet logging */
1379 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1382 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1385 end_log_omission(ssh, pkt);
1389 /* Deal with logfile omission, if required. */
1390 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1392 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1394 pkt->blanks[pkt->nblanks-1].offset = offset;
1395 pkt->blanks[pkt->nblanks-1].len = len;
1396 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1403 static void send_packet(Ssh ssh, int pkttype, ...)
1407 va_start(ap1, pkttype);
1408 va_start(ap2, pkttype);
1409 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1413 ssh_free_packet(pkt);
1416 static void defer_packet(Ssh ssh, int pkttype, ...)
1420 va_start(ap1, pkttype);
1421 va_start(ap2, pkttype);
1422 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1425 s_wrpkt_defer(ssh, pkt);
1426 ssh_free_packet(pkt);
1429 static int ssh_versioncmp(char *a, char *b)
1432 unsigned long av, bv;
1434 av = strtoul(a, &ae, 10);
1435 bv = strtoul(b, &be, 10);
1437 return (av < bv ? -1 : +1);
1442 av = strtoul(ae, &ae, 10);
1443 bv = strtoul(be, &be, 10);
1445 return (av < bv ? -1 : +1);
1450 * Utility routines for putting an SSH-protocol `string' and
1451 * `uint32' into a SHA state.
1454 static void sha_string(SHA_State * s, void *str, int len)
1456 unsigned char lenblk[4];
1457 PUT_32BIT(lenblk, len);
1458 SHA_Bytes(s, lenblk, 4);
1459 SHA_Bytes(s, str, len);
1462 static void sha_uint32(SHA_State * s, unsigned i)
1464 unsigned char intblk[4];
1465 PUT_32BIT(intblk, i);
1466 SHA_Bytes(s, intblk, 4);
1470 * SSH2 packet construction functions.
1472 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1474 if (pkt->maxlen < length) {
1475 pkt->maxlen = length + 256;
1476 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1479 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1481 if (pkt->logmode != PKTLOG_EMIT) {
1483 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1484 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1485 pkt->blanks[pkt->nblanks-1].len = len;
1486 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1489 ssh2_pkt_ensure(pkt, pkt->length);
1490 memcpy(pkt->data + pkt->length - len, data, len);
1492 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1494 ssh2_pkt_adddata(pkt, &byte, 1);
1496 static struct Packet *ssh2_pkt_init(int pkt_type)
1498 struct Packet *pkt = ssh_new_packet();
1500 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1503 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1505 ssh2_pkt_adddata(pkt, &value, 1);
1507 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1510 PUT_32BIT(x, value);
1511 ssh2_pkt_adddata(pkt, x, 4);
1513 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1515 ssh2_pkt_adduint32(pkt, 0);
1516 pkt->savedpos = pkt->length;
1518 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1520 ssh2_pkt_adddata(pkt, data, strlen(data));
1521 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1523 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1525 ssh2_pkt_adddata(pkt, data, len);
1526 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1528 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1530 ssh2_pkt_addstring_start(pkt);
1531 ssh2_pkt_addstring_str(pkt, data);
1533 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1536 int i, n = (bignum_bitcount(b) + 7) / 8;
1537 p = snewn(n + 1, unsigned char);
1539 fatalbox("out of memory");
1541 for (i = 1; i <= n; i++)
1542 p[i] = bignum_byte(b, n - i);
1544 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1546 memmove(p, p + i, n + 1 - i);
1550 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1554 p = ssh2_mpint_fmt(b, &len);
1555 ssh2_pkt_addstring_start(pkt);
1556 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1561 * Construct an SSH2 final-form packet: compress it, encrypt it,
1562 * put the MAC on it. Final packet, ready to be sent, is stored in
1563 * pkt->data. Total length is returned.
1565 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1567 int cipherblk, maclen, padding, i;
1570 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1571 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1572 pkt->data + 6, pkt->length - 6,
1573 pkt->nblanks, pkt->blanks);
1574 sfree(pkt->blanks); pkt->blanks = NULL;
1578 * Compress packet payload.
1581 unsigned char *newpayload;
1584 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1586 &newpayload, &newlen)) {
1588 ssh2_pkt_adddata(pkt, newpayload, newlen);
1594 * Add padding. At least four bytes, and must also bring total
1595 * length (minus MAC) up to a multiple of the block size.
1597 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1598 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1601 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1602 maclen = ssh->csmac ? ssh->csmac->len : 0;
1603 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1604 pkt->data[4] = padding;
1605 for (i = 0; i < padding; i++)
1606 pkt->data[pkt->length + i] = random_byte();
1607 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1609 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1610 pkt->length + padding,
1611 ssh->v2_outgoing_sequence);
1612 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1615 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1616 pkt->data, pkt->length + padding);
1618 pkt->encrypted_len = pkt->length + padding;
1620 /* Ready-to-send packet starts at pkt->data. We return length. */
1621 return pkt->length + padding + maclen;
1625 * Routines called from the main SSH code to send packets. There
1626 * are quite a few of these, because we have two separate
1627 * mechanisms for delaying the sending of packets:
1629 * - In order to send an IGNORE message and a password message in
1630 * a single fixed-length blob, we require the ability to
1631 * concatenate the encrypted forms of those two packets _into_ a
1632 * single blob and then pass it to our <network.h> transport
1633 * layer in one go. Hence, there's a deferment mechanism which
1634 * works after packet encryption.
1636 * - In order to avoid sending any connection-layer messages
1637 * during repeat key exchange, we have to queue up any such
1638 * outgoing messages _before_ they are encrypted (and in
1639 * particular before they're allocated sequence numbers), and
1640 * then send them once we've finished.
1642 * I call these mechanisms `defer' and `queue' respectively, so as
1643 * to distinguish them reasonably easily.
1645 * The functions send_noqueue() and defer_noqueue() free the packet
1646 * structure they are passed. Every outgoing packet goes through
1647 * precisely one of these functions in its life; packets passed to
1648 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1649 * these or get queued, and then when the queue is later emptied
1650 * the packets are all passed to defer_noqueue().
1654 * Send an SSH2 packet immediately, without queuing or deferring.
1656 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1660 len = ssh2_pkt_construct(ssh, pkt);
1661 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1662 if (backlog > SSH_MAX_BACKLOG)
1663 ssh_throttle_all(ssh, 1, backlog);
1665 ssh->outgoing_data_size += pkt->encrypted_len;
1666 if (!ssh->kex_in_progress &&
1667 ssh->max_data_size != 0 &&
1668 ssh->outgoing_data_size > ssh->max_data_size)
1669 do_ssh2_transport(ssh, "Initiating key re-exchange "
1670 "(too much data sent)", -1, NULL);
1672 ssh_free_packet(pkt);
1676 * Defer an SSH2 packet.
1678 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1680 int len = ssh2_pkt_construct(ssh, pkt);
1681 if (ssh->deferred_len + len > ssh->deferred_size) {
1682 ssh->deferred_size = ssh->deferred_len + len + 128;
1683 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1687 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1688 ssh->deferred_len += len;
1689 ssh->deferred_data_size += pkt->encrypted_len;
1690 ssh_free_packet(pkt);
1694 * Queue an SSH2 packet.
1696 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1698 assert(ssh->queueing);
1700 if (ssh->queuelen >= ssh->queuesize) {
1701 ssh->queuesize = ssh->queuelen + 32;
1702 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1705 ssh->queue[ssh->queuelen++] = pkt;
1709 * Either queue or send a packet, depending on whether queueing is
1712 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1715 ssh2_pkt_queue(ssh, pkt);
1717 ssh2_pkt_send_noqueue(ssh, pkt);
1721 * Either queue or defer a packet, depending on whether queueing is
1724 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1727 ssh2_pkt_queue(ssh, pkt);
1729 ssh2_pkt_defer_noqueue(ssh, pkt);
1733 * Send the whole deferred data block constructed by
1734 * ssh2_pkt_defer() or SSH1's defer_packet().
1736 * The expected use of the defer mechanism is that you call
1737 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1738 * not currently queueing, this simply sets up deferred_send_data
1739 * and then sends it. If we _are_ currently queueing, the calls to
1740 * ssh2_pkt_defer() put the deferred packets on to the queue
1741 * instead, and therefore ssh_pkt_defersend() has no deferred data
1742 * to send. Hence, there's no need to make it conditional on
1745 static void ssh_pkt_defersend(Ssh ssh)
1748 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1750 ssh->deferred_len = ssh->deferred_size = 0;
1751 sfree(ssh->deferred_send_data);
1752 ssh->deferred_send_data = NULL;
1753 if (backlog > SSH_MAX_BACKLOG)
1754 ssh_throttle_all(ssh, 1, backlog);
1756 ssh->outgoing_data_size += ssh->deferred_data_size;
1757 if (!ssh->kex_in_progress &&
1758 ssh->max_data_size != 0 &&
1759 ssh->outgoing_data_size > ssh->max_data_size)
1760 do_ssh2_transport(ssh, "Initiating key re-exchange "
1761 "(too much data sent)", -1, NULL);
1762 ssh->deferred_data_size = 0;
1766 * Send all queued SSH2 packets. We send them by means of
1767 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1768 * packets that needed to be lumped together.
1770 static void ssh2_pkt_queuesend(Ssh ssh)
1774 assert(!ssh->queueing);
1776 for (i = 0; i < ssh->queuelen; i++)
1777 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1780 ssh_pkt_defersend(ssh);
1784 void bndebug(char *string, Bignum b)
1788 p = ssh2_mpint_fmt(b, &len);
1789 debug(("%s", string));
1790 for (i = 0; i < len; i++)
1791 debug((" %02x", p[i]));
1797 static void sha_mpint(SHA_State * s, Bignum b)
1801 p = ssh2_mpint_fmt(b, &len);
1802 sha_string(s, p, len);
1807 * Packet decode functions for both SSH1 and SSH2.
1809 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1811 unsigned long value;
1812 if (pkt->length - pkt->savedpos < 4)
1813 return 0; /* arrgh, no way to decline (FIXME?) */
1814 value = GET_32BIT(pkt->body + pkt->savedpos);
1818 static int ssh2_pkt_getbool(struct Packet *pkt)
1820 unsigned long value;
1821 if (pkt->length - pkt->savedpos < 1)
1822 return 0; /* arrgh, no way to decline (FIXME?) */
1823 value = pkt->body[pkt->savedpos] != 0;
1827 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1832 if (pkt->length - pkt->savedpos < 4)
1834 len = GET_32BIT(pkt->body + pkt->savedpos);
1839 if (pkt->length - pkt->savedpos < *length)
1841 *p = (char *)(pkt->body + pkt->savedpos);
1842 pkt->savedpos += *length;
1844 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1846 if (pkt->length - pkt->savedpos < length)
1848 pkt->savedpos += length;
1849 return pkt->body + (pkt->savedpos - length);
1851 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1852 unsigned char **keystr)
1856 j = makekey(pkt->body + pkt->savedpos,
1857 pkt->length - pkt->savedpos,
1864 assert(pkt->savedpos < pkt->length);
1868 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1873 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1874 pkt->length - pkt->savedpos, &b);
1882 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1888 ssh_pkt_getstring(pkt, &p, &length);
1893 b = bignum_from_bytes((unsigned char *)p, length);
1898 * Helper function to add an SSH2 signature blob to a packet.
1899 * Expects to be shown the public key blob as well as the signature
1900 * blob. Normally works just like ssh2_pkt_addstring, but will
1901 * fiddle with the signature packet if necessary for
1902 * BUG_SSH2_RSA_PADDING.
1904 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1905 void *pkblob_v, int pkblob_len,
1906 void *sigblob_v, int sigblob_len)
1908 unsigned char *pkblob = (unsigned char *)pkblob_v;
1909 unsigned char *sigblob = (unsigned char *)sigblob_v;
1911 /* dmemdump(pkblob, pkblob_len); */
1912 /* dmemdump(sigblob, sigblob_len); */
1915 * See if this is in fact an ssh-rsa signature and a buggy
1916 * server; otherwise we can just do this the easy way.
1918 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1919 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1920 int pos, len, siglen;
1923 * Find the byte length of the modulus.
1926 pos = 4+7; /* skip over "ssh-rsa" */
1927 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1928 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1929 pos += 4; /* find modulus itself */
1930 while (len > 0 && pkblob[pos] == 0)
1932 /* debug(("modulus length is %d\n", len)); */
1935 * Now find the signature integer.
1937 pos = 4+7; /* skip over "ssh-rsa" */
1938 siglen = GET_32BIT(sigblob+pos);
1939 /* debug(("signature length is %d\n", siglen)); */
1941 if (len != siglen) {
1942 unsigned char newlen[4];
1943 ssh2_pkt_addstring_start(pkt);
1944 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1945 /* dmemdump(sigblob, pos); */
1946 pos += 4; /* point to start of actual sig */
1947 PUT_32BIT(newlen, len);
1948 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1949 /* dmemdump(newlen, 4); */
1951 while (len-- > siglen) {
1952 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1953 /* dmemdump(newlen, 1); */
1955 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1956 /* dmemdump(sigblob+pos, siglen); */
1960 /* Otherwise fall through and do it the easy way. */
1963 ssh2_pkt_addstring_start(pkt);
1964 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1968 * Examine the remote side's version string and compare it against
1969 * a list of known buggy implementations.
1971 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1973 char *imp; /* pointer to implementation part */
1975 imp += strcspn(imp, "-");
1977 imp += strcspn(imp, "-");
1980 ssh->remote_bugs = 0;
1982 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1983 (ssh->cfg.sshbug_ignore1 == AUTO &&
1984 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1985 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1986 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1987 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1989 * These versions don't support SSH1_MSG_IGNORE, so we have
1990 * to use a different defence against password length
1993 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1994 logevent("We believe remote version has SSH1 ignore bug");
1997 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1998 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1999 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2001 * These versions need a plain password sent; they can't
2002 * handle having a null and a random length of data after
2005 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2006 logevent("We believe remote version needs a plain SSH1 password");
2009 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2010 (ssh->cfg.sshbug_rsa1 == AUTO &&
2011 (!strcmp(imp, "Cisco-1.25")))) {
2013 * These versions apparently have no clue whatever about
2014 * RSA authentication and will panic and die if they see
2015 * an AUTH_RSA message.
2017 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2018 logevent("We believe remote version can't handle RSA authentication");
2021 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2022 (ssh->cfg.sshbug_hmac2 == AUTO &&
2023 !wc_match("* VShell", imp) &&
2024 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2025 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2026 wc_match("2.1 *", imp)))) {
2028 * These versions have the HMAC bug.
2030 ssh->remote_bugs |= BUG_SSH2_HMAC;
2031 logevent("We believe remote version has SSH2 HMAC bug");
2034 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2035 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2036 !wc_match("* VShell", imp) &&
2037 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2039 * These versions have the key-derivation bug (failing to
2040 * include the literal shared secret in the hashes that
2041 * generate the keys).
2043 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2044 logevent("We believe remote version has SSH2 key-derivation bug");
2047 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2048 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2049 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2050 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2052 * These versions have the SSH2 RSA padding bug.
2054 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2055 logevent("We believe remote version has SSH2 RSA padding bug");
2058 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2059 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2060 wc_match("OpenSSH_2.[0-2]*", imp))) {
2062 * These versions have the SSH2 session-ID bug in
2063 * public-key authentication.
2065 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2066 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2071 * The `software version' part of an SSH version string is required
2072 * to contain no spaces or minus signs.
2074 static void ssh_fix_verstring(char *str)
2076 /* Eat "SSH-<protoversion>-". */
2077 assert(*str == 'S'); str++;
2078 assert(*str == 'S'); str++;
2079 assert(*str == 'H'); str++;
2080 assert(*str == '-'); str++;
2081 while (*str && *str != '-') str++;
2082 assert(*str == '-'); str++;
2084 /* Convert minus signs and spaces in the remaining string into
2087 if (*str == '-' || *str == ' ')
2093 static int do_ssh_init(Ssh ssh, unsigned char c)
2095 struct do_ssh_init_state {
2103 crState(do_ssh_init_state);
2105 crBegin(ssh->do_ssh_init_crstate);
2107 /* Search for the string "SSH-" in the input. */
2110 static const int transS[] = { 1, 2, 2, 1 };
2111 static const int transH[] = { 0, 0, 3, 0 };
2112 static const int transminus[] = { 0, 0, 0, -1 };
2114 s->i = transS[s->i];
2116 s->i = transH[s->i];
2118 s->i = transminus[s->i];
2123 crReturn(1); /* get another character */
2127 s->vstring = snewn(s->vstrsize, char);
2128 strcpy(s->vstring, "SSH-");
2132 crReturn(1); /* get another char */
2133 if (s->vslen >= s->vstrsize - 1) {
2135 s->vstring = sresize(s->vstring, s->vstrsize, char);
2137 s->vstring[s->vslen++] = c;
2140 s->version[s->i] = '\0';
2142 } else if (s->i < sizeof(s->version) - 1)
2143 s->version[s->i++] = c;
2144 } else if (c == '\012')
2148 ssh->agentfwd_enabled = FALSE;
2149 ssh->rdpkt2_state.incoming_sequence = 0;
2151 s->vstring[s->vslen] = 0;
2152 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2155 vlog = snewn(20 + s->vslen, char);
2156 sprintf(vlog, "Server version: %s", s->vstring);
2160 ssh_detect_bugs(ssh, s->vstring);
2163 * Decide which SSH protocol version to support.
2166 /* Anything strictly below "2.0" means protocol 1 is supported. */
2167 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2168 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2169 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2171 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2172 bombout(("SSH protocol version 1 required by user but not provided by server"));
2175 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2176 bombout(("SSH protocol version 2 required by user but not provided by server"));
2183 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2185 * Construct a v2 version string.
2187 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2191 * Construct a v1 version string.
2193 verstring = dupprintf("SSH-%s-%s\012",
2194 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2195 s->version : "1.5"),
2200 ssh_fix_verstring(verstring);
2202 if (ssh->version == 2) {
2204 * Hash our version string and their version string.
2206 SHA_Init(&ssh->exhashbase);
2207 sha_string(&ssh->exhashbase, verstring,
2208 strcspn(verstring, "\015\012"));
2209 sha_string(&ssh->exhashbase, s->vstring,
2210 strcspn(s->vstring, "\015\012"));
2213 * Initialise SSHv2 protocol.
2215 ssh->protocol = ssh2_protocol;
2216 ssh2_protocol_setup(ssh);
2217 ssh->s_rdpkt = ssh2_rdpkt;
2220 * Initialise SSHv1 protocol.
2222 ssh->protocol = ssh1_protocol;
2223 ssh1_protocol_setup(ssh);
2224 ssh->s_rdpkt = ssh1_rdpkt;
2226 logeventf(ssh, "We claim version: %.*s",
2227 strcspn(verstring, "\015\012"), verstring);
2228 sk_write(ssh->s, verstring, strlen(verstring));
2232 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2234 update_specials_menu(ssh->frontend);
2235 ssh->state = SSH_STATE_BEFORE_SIZE;
2236 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2243 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2245 crBegin(ssh->ssh_gotdata_crstate);
2248 * To begin with, feed the characters one by one to the
2249 * protocol initialisation / selection function do_ssh_init().
2250 * When that returns 0, we're done with the initial greeting
2251 * exchange and can move on to packet discipline.
2254 int ret; /* need not be kept across crReturn */
2256 crReturnV; /* more data please */
2257 ret = do_ssh_init(ssh, *data);
2265 * We emerge from that loop when the initial negotiation is
2266 * over and we have selected an s_rdpkt function. Now pass
2267 * everything to s_rdpkt, and then pass the resulting packets
2268 * to the proper protocol handler.
2273 while (datalen > 0) {
2274 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2276 ssh->protocol(ssh, NULL, 0, pktin);
2277 ssh_free_packet(pktin);
2279 if (ssh->state == SSH_STATE_CLOSED)
2287 static void ssh_do_close(Ssh ssh)
2290 struct ssh_channel *c;
2292 ssh->state = SSH_STATE_CLOSED;
2296 notify_remote_exit(ssh->frontend);
2299 * Now we must shut down any port and X forwardings going
2300 * through this connection.
2302 if (ssh->channels) {
2303 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2306 x11_close(c->u.x11.s);
2309 pfd_close(c->u.pfd.s);
2312 del234(ssh->channels, c);
2313 if (ssh->version == 2)
2314 bufchain_clear(&c->v.v2.outbuffer);
2320 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2323 Ssh ssh = (Ssh) plug;
2326 /* A socket error has occurred. */
2327 logevent(error_msg);
2328 connection_fatal(ssh->frontend, "%s", error_msg);
2330 /* Otherwise, the remote side closed the connection normally. */
2335 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2337 Ssh ssh = (Ssh) plug;
2338 ssh_gotdata(ssh, (unsigned char *)data, len);
2339 if (ssh->state == SSH_STATE_CLOSED) {
2346 static void ssh_sent(Plug plug, int bufsize)
2348 Ssh ssh = (Ssh) plug;
2350 * If the send backlog on the SSH socket itself clears, we
2351 * should unthrottle the whole world if it was throttled.
2353 if (bufsize < SSH_MAX_BACKLOG)
2354 ssh_throttle_all(ssh, 0, bufsize);
2358 * Connect to specified host and port.
2359 * Returns an error message, or NULL on success.
2360 * Also places the canonical host name into `realhost'. It must be
2361 * freed by the caller.
2363 static const char *connect_to_host(Ssh ssh, char *host, int port,
2364 char **realhost, int nodelay, int keepalive)
2366 static const struct plug_function_table fn_table = {
2376 ssh->savedhost = snewn(1 + strlen(host), char);
2377 if (!ssh->savedhost)
2378 fatalbox("Out of memory");
2379 strcpy(ssh->savedhost, host);
2382 port = 22; /* default ssh port */
2383 ssh->savedport = port;
2388 logeventf(ssh, "Looking up host \"%s\"", host);
2389 addr = name_lookup(host, port, realhost, &ssh->cfg);
2390 if ((err = sk_addr_error(addr)) != NULL) {
2400 sk_getaddr(addr, addrbuf, 100);
2401 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2403 ssh->fn = &fn_table;
2404 ssh->s = new_connection(addr, *realhost, port,
2405 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2406 if ((err = sk_socket_error(ssh->s)) != NULL) {
2408 notify_remote_exit(ssh->frontend);
2416 * Throttle or unthrottle the SSH connection.
2418 static void ssh1_throttle(Ssh ssh, int adjust)
2420 int old_count = ssh->v1_throttle_count;
2421 ssh->v1_throttle_count += adjust;
2422 assert(ssh->v1_throttle_count >= 0);
2423 if (ssh->v1_throttle_count && !old_count) {
2424 sk_set_frozen(ssh->s, 1);
2425 } else if (!ssh->v1_throttle_count && old_count) {
2426 sk_set_frozen(ssh->s, 0);
2431 * Throttle or unthrottle _all_ local data streams (for when sends
2432 * on the SSH connection itself back up).
2434 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2437 struct ssh_channel *c;
2439 if (enable == ssh->throttled_all)
2441 ssh->throttled_all = enable;
2442 ssh->overall_bufsize = bufsize;
2445 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2447 case CHAN_MAINSESSION:
2449 * This is treated separately, outside the switch.
2453 x11_override_throttle(c->u.x11.s, enable);
2456 /* Agent channels require no buffer management. */
2459 pfd_override_throttle(c->u.pfd.s, enable);
2466 * Username and password input, abstracted off into routines
2467 * reusable in several places - even between SSH1 and SSH2.
2470 /* Set up a username or password input loop on a given buffer. */
2471 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2473 ssh->userpass_input_buffer = buffer;
2474 ssh->userpass_input_buflen = buflen;
2475 ssh->userpass_input_bufpos = 0;
2476 ssh->userpass_input_echo = echo;
2480 * Process some terminal data in the course of username/password
2481 * input. Returns >0 for success (line of input returned in
2482 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2483 * for inconclusive (keep waiting for more input please).
2485 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2490 switch (c = *in++) {
2493 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2494 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2499 if (ssh->userpass_input_bufpos > 0) {
2500 if (ssh->userpass_input_echo)
2501 c_write_str(ssh, "\b \b");
2502 ssh->userpass_input_bufpos--;
2507 while (ssh->userpass_input_bufpos > 0) {
2508 if (ssh->userpass_input_echo)
2509 c_write_str(ssh, "\b \b");
2510 ssh->userpass_input_bufpos--;
2519 * This simplistic check for printability is disabled
2520 * when we're doing password input, because some people
2521 * have control characters in their passwords.o
2523 if ((!ssh->userpass_input_echo ||
2524 (c >= ' ' && c <= '~') ||
2525 ((unsigned char) c >= 160))
2526 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2527 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2528 if (ssh->userpass_input_echo)
2529 c_write(ssh, &c, 1);
2537 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2539 Ssh ssh = (Ssh) sshv;
2541 ssh->agent_response = reply;
2542 ssh->agent_response_len = replylen;
2544 if (ssh->version == 1)
2545 do_ssh1_login(ssh, NULL, -1, NULL);
2547 do_ssh2_authconn(ssh, NULL, -1, NULL);
2550 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2552 struct ssh_channel *c = (struct ssh_channel *)cv;
2554 void *sentreply = reply;
2557 /* Fake SSH_AGENT_FAILURE. */
2558 sentreply = "\0\0\0\1\5";
2561 if (ssh->version == 2) {
2562 ssh2_add_channel_data(c, sentreply, replylen);
2565 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2566 PKT_INT, c->remoteid,
2569 PKT_DATA, sentreply, replylen,
2578 * Handle the key exchange and user authentication phases.
2580 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2581 struct Packet *pktin)
2584 unsigned char cookie[8], *ptr;
2585 struct RSAKey servkey, hostkey;
2586 struct MD5Context md5c;
2587 struct do_ssh1_login_state {
2589 unsigned char *rsabuf, *keystr1, *keystr2;
2590 unsigned long supported_ciphers_mask, supported_auths_mask;
2591 int tried_publickey, tried_agent;
2592 int tis_auth_refused, ccard_auth_refused;
2593 unsigned char session_id[16];
2596 void *publickey_blob;
2597 int publickey_bloblen;
2603 unsigned char request[5], *response, *p;
2612 crState(do_ssh1_login_state);
2614 crBegin(ssh->do_ssh1_login_crstate);
2619 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2620 bombout(("Public key packet not received"));
2624 logevent("Received public keys");
2626 ptr = ssh_pkt_getdata(pktin, 8);
2628 bombout(("SSH1 public key packet stopped before random cookie"));
2631 memcpy(cookie, ptr, 8);
2633 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2634 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2635 bombout(("Failed to read SSH1 public keys from public key packet"));
2640 * Log the host key fingerprint.
2644 logevent("Host key fingerprint is:");
2645 strcpy(logmsg, " ");
2646 hostkey.comment = NULL;
2647 rsa_fingerprint(logmsg + strlen(logmsg),
2648 sizeof(logmsg) - strlen(logmsg), &hostkey);
2652 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2653 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2654 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2656 ssh->v1_local_protoflags =
2657 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2658 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2661 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2662 MD5Update(&md5c, s->keystr1, servkey.bytes);
2663 MD5Update(&md5c, cookie, 8);
2664 MD5Final(s->session_id, &md5c);
2666 for (i = 0; i < 32; i++)
2667 ssh->session_key[i] = random_byte();
2670 * Verify that the `bits' and `bytes' parameters match.
2672 if (hostkey.bits > hostkey.bytes * 8 ||
2673 servkey.bits > servkey.bytes * 8) {
2674 bombout(("SSH1 public keys were badly formatted"));
2678 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2680 s->rsabuf = snewn(s->len, unsigned char);
2682 fatalbox("Out of memory");
2685 * Verify the host key.
2689 * First format the key into a string.
2691 int len = rsastr_len(&hostkey);
2692 char fingerprint[100];
2693 char *keystr = snewn(len, char);
2695 fatalbox("Out of memory");
2696 rsastr_fmt(keystr, &hostkey);
2697 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2698 verify_ssh_host_key(ssh->frontend,
2699 ssh->savedhost, ssh->savedport, "rsa", keystr,
2704 for (i = 0; i < 32; i++) {
2705 s->rsabuf[i] = ssh->session_key[i];
2707 s->rsabuf[i] ^= s->session_id[i];
2710 if (hostkey.bytes > servkey.bytes) {
2711 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2713 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2715 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2717 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2720 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2724 logevent("Encrypted session key");
2727 int cipher_chosen = 0, warn = 0;
2728 char *cipher_string = NULL;
2730 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2731 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2732 if (next_cipher == CIPHER_WARN) {
2733 /* If/when we choose a cipher, warn about it */
2735 } else if (next_cipher == CIPHER_AES) {
2736 /* XXX Probably don't need to mention this. */
2737 logevent("AES not supported in SSH1, skipping");
2739 switch (next_cipher) {
2740 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2741 cipher_string = "3DES"; break;
2742 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2743 cipher_string = "Blowfish"; break;
2744 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2745 cipher_string = "single-DES"; break;
2747 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2751 if (!cipher_chosen) {
2752 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2753 bombout(("Server violates SSH 1 protocol by not "
2754 "supporting 3DES encryption"));
2756 /* shouldn't happen */
2757 bombout(("No supported ciphers found"));
2761 /* Warn about chosen cipher if necessary. */
2763 askalg(ssh->frontend, "cipher", cipher_string);
2766 switch (s->cipher_type) {
2767 case SSH_CIPHER_3DES:
2768 logevent("Using 3DES encryption");
2770 case SSH_CIPHER_DES:
2771 logevent("Using single-DES encryption");
2773 case SSH_CIPHER_BLOWFISH:
2774 logevent("Using Blowfish encryption");
2778 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2779 PKT_CHAR, s->cipher_type,
2780 PKT_DATA, cookie, 8,
2781 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2782 PKT_DATA, s->rsabuf, s->len,
2783 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2785 logevent("Trying to enable encryption...");
2789 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2790 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2792 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2793 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2794 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2796 ssh->crcda_ctx = crcda_make_context();
2797 logevent("Installing CRC compensation attack detector");
2799 if (servkey.modulus) {
2800 sfree(servkey.modulus);
2801 servkey.modulus = NULL;
2803 if (servkey.exponent) {
2804 sfree(servkey.exponent);
2805 servkey.exponent = NULL;
2807 if (hostkey.modulus) {
2808 sfree(hostkey.modulus);
2809 hostkey.modulus = NULL;
2811 if (hostkey.exponent) {
2812 sfree(hostkey.exponent);
2813 hostkey.exponent = NULL;
2817 if (pktin->type != SSH1_SMSG_SUCCESS) {
2818 bombout(("Encryption not successfully enabled"));
2822 logevent("Successfully started encryption");
2826 if (!*ssh->cfg.username) {
2827 if (ssh_get_line && !ssh_getline_pw_only) {
2828 if (!ssh_get_line("login as: ",
2829 s->username, sizeof(s->username), FALSE)) {
2831 * get_line failed to get a username.
2834 logevent("No username provided. Abandoning session.");
2835 ssh_closing((Plug)ssh, NULL, 0, 0);
2839 int ret; /* need not be kept over crReturn */
2840 c_write_str(ssh, "login as: ");
2843 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2845 crWaitUntil(!pktin);
2846 ret = process_userpass_input(ssh, in, inlen);
2850 c_write_str(ssh, "\r\n");
2853 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2854 s->username[sizeof(s->username)-1] = '\0';
2857 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2859 char userlog[22 + sizeof(s->username)];
2860 sprintf(userlog, "Sent username \"%s\"", s->username);
2862 if (flags & FLAG_INTERACTIVE &&
2863 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2864 strcat(userlog, "\r\n");
2865 c_write_str(ssh, userlog);
2872 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2873 /* We must not attempt PK auth. Pretend we've already tried it. */
2874 s->tried_publickey = s->tried_agent = 1;
2876 s->tried_publickey = s->tried_agent = 0;
2878 s->tis_auth_refused = s->ccard_auth_refused = 0;
2879 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2880 if (!filename_is_null(ssh->cfg.keyfile)) {
2881 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2882 &s->publickey_blob, &s->publickey_bloblen, NULL))
2883 s->publickey_blob = NULL;
2885 s->publickey_blob = NULL;
2887 while (pktin->type == SSH1_SMSG_FAILURE) {
2888 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2890 if (agent_exists() && !s->tried_agent) {
2892 * Attempt RSA authentication using Pageant.
2898 logevent("Pageant is running. Requesting keys.");
2900 /* Request the keys held by the agent. */
2901 PUT_32BIT(s->request, 1);
2902 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2903 if (!agent_query(s->request, 5, &r, &s->responselen,
2904 ssh_agent_callback, ssh)) {
2908 bombout(("Unexpected data from server while waiting"
2909 " for agent response"));
2912 } while (pktin || inlen > 0);
2913 r = ssh->agent_response;
2914 s->responselen = ssh->agent_response_len;
2916 s->response = (unsigned char *) r;
2917 if (s->response && s->responselen >= 5 &&
2918 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2919 s->p = s->response + 5;
2920 s->nkeys = GET_32BIT(s->p);
2924 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2927 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2930 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2933 if (s->publickey_blob &&
2934 !memcmp(s->p, s->publickey_blob,
2935 s->publickey_bloblen)) {
2936 logevent("This key matches configured key file");
2937 s->tried_publickey = 1;
2942 do { /* do while (0) to make breaking easy */
2943 n = ssh1_read_bignum
2944 (s->p, s->responselen-(s->p-s->response),
2949 n = ssh1_read_bignum
2950 (s->p, s->responselen-(s->p-s->response),
2955 if (s->responselen - (s->p-s->response) < 4)
2957 s->commentlen = GET_32BIT(s->p);
2959 if (s->responselen - (s->p-s->response) <
2962 s->commentp = (char *)s->p;
2963 s->p += s->commentlen;
2967 logevent("Pageant key list packet was truncated");
2971 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2972 PKT_BIGNUM, s->key.modulus, PKT_END);
2974 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2975 logevent("Key refused");
2978 logevent("Received RSA challenge");
2979 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
2980 bombout(("Server's RSA challenge was badly formatted"));
2985 char *agentreq, *q, *ret;
2988 len = 1 + 4; /* message type, bit count */
2989 len += ssh1_bignum_length(s->key.exponent);
2990 len += ssh1_bignum_length(s->key.modulus);
2991 len += ssh1_bignum_length(s->challenge);
2992 len += 16; /* session id */
2993 len += 4; /* response format */
2994 agentreq = snewn(4 + len, char);
2995 PUT_32BIT(agentreq, len);
2997 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2998 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3000 q += ssh1_write_bignum(q, s->key.exponent);
3001 q += ssh1_write_bignum(q, s->key.modulus);
3002 q += ssh1_write_bignum(q, s->challenge);
3003 memcpy(q, s->session_id, 16);
3005 PUT_32BIT(q, 1); /* response format */
3006 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3007 ssh_agent_callback, ssh)) {
3012 bombout(("Unexpected data from server"
3013 " while waiting for agent"
3017 } while (pktin || inlen > 0);
3018 vret = ssh->agent_response;
3019 retlen = ssh->agent_response_len;
3024 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3025 logevent("Sending Pageant's response");
3026 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3027 PKT_DATA, ret + 5, 16,
3031 if (pktin->type == SSH1_SMSG_SUCCESS) {
3033 ("Pageant's response accepted");
3034 if (flags & FLAG_VERBOSE) {
3035 c_write_str(ssh, "Authenticated using"
3037 c_write(ssh, s->commentp,
3039 c_write_str(ssh, "\" from agent\r\n");
3044 ("Pageant's response not accepted");
3047 ("Pageant failed to answer challenge");
3051 logevent("No reply received from Pageant");
3054 freebn(s->key.exponent);
3055 freebn(s->key.modulus);
3056 freebn(s->challenge);
3065 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3066 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3068 if (ssh->cfg.try_tis_auth &&
3069 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3070 !s->tis_auth_refused) {
3071 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3072 logevent("Requested TIS authentication");
3073 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3075 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3076 logevent("TIS authentication declined");
3077 if (flags & FLAG_INTERACTIVE)
3078 c_write_str(ssh, "TIS authentication refused.\r\n");
3079 s->tis_auth_refused = 1;
3085 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3087 bombout(("TIS challenge packet was badly formed"));
3090 logevent("Received TIS challenge");
3091 if (challengelen > sizeof(s->prompt) - 1)
3092 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3093 memcpy(s->prompt, challenge, challengelen);
3094 /* Prompt heuristic comes from OpenSSH */
3095 strncpy(s->prompt + challengelen,
3096 memchr(s->prompt, '\n', challengelen) ?
3097 "": "\r\nResponse: ",
3098 (sizeof s->prompt) - challengelen);
3099 s->prompt[(sizeof s->prompt) - 1] = '\0';
3102 if (ssh->cfg.try_tis_auth &&
3103 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3104 !s->ccard_auth_refused) {
3105 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3106 logevent("Requested CryptoCard authentication");
3107 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3109 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3110 logevent("CryptoCard authentication declined");
3111 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3112 s->ccard_auth_refused = 1;
3118 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3120 bombout(("CryptoCard challenge packet was badly formed"));
3123 logevent("Received CryptoCard challenge");
3124 if (challengelen > sizeof(s->prompt) - 1)
3125 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3126 memcpy(s->prompt, challenge, challengelen);
3127 strncpy(s->prompt + challengelen,
3128 memchr(s->prompt, '\n', challengelen) ?
3129 "" : "\r\nResponse: ",
3130 sizeof(s->prompt) - challengelen);
3131 s->prompt[sizeof(s->prompt) - 1] = '\0';
3134 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3135 sprintf(s->prompt, "%.90s@%.90s's password: ",
3136 s->username, ssh->savedhost);
3138 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3139 char *comment = NULL;
3142 if (flags & FLAG_VERBOSE)
3143 c_write_str(ssh, "Trying public key authentication.\r\n");
3144 logeventf(ssh, "Trying public key \"%s\"",
3145 filename_to_str(&ssh->cfg.keyfile));
3146 type = key_type(&ssh->cfg.keyfile);
3147 if (type != SSH_KEYTYPE_SSH1) {
3148 sprintf(msgbuf, "Key is of wrong type (%s)",
3149 key_type_to_str(type));
3151 c_write_str(ssh, msgbuf);
3152 c_write_str(ssh, "\r\n");
3153 s->tried_publickey = 1;
3156 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3157 if (flags & FLAG_VERBOSE)
3158 c_write_str(ssh, "No passphrase required.\r\n");
3161 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3166 * Show password prompt, having first obtained it via a TIS
3167 * or CryptoCard exchange if we're doing TIS or CryptoCard
3171 if (!ssh_get_line(s->prompt, s->password,
3172 sizeof(s->password), TRUE)) {
3174 * get_line failed to get a password (for example
3175 * because one was supplied on the command line
3176 * which has already failed to work). Terminate.
3178 send_packet(ssh, SSH1_MSG_DISCONNECT,
3179 PKT_STR, "No more passwords available to try",
3181 logevent("Unable to authenticate");
3182 connection_fatal(ssh->frontend, "Unable to authenticate");
3183 ssh_closing((Plug)ssh, NULL, 0, 0);
3187 /* Prompt may have come from server. We've munged it a bit, so
3188 * we know it to be zero-terminated at least once. */
3189 int ret; /* need not be saved over crReturn */
3190 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3193 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3195 crWaitUntil(!pktin);
3196 ret = process_userpass_input(ssh, in, inlen);
3200 c_write_str(ssh, "\r\n");
3204 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3206 * Try public key authentication with the specified
3209 s->tried_publickey = 1;
3212 const char *error = NULL;
3213 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3216 c_write_str(ssh, "Couldn't load private key from ");
3217 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3218 c_write_str(ssh, " (");
3219 c_write_str(ssh, error);
3220 c_write_str(ssh, ").\r\n");
3221 continue; /* go and try password */
3224 c_write_str(ssh, "Wrong passphrase.\r\n");
3225 s->tried_publickey = 0;
3226 continue; /* try again */
3231 * Send a public key attempt.
3233 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3234 PKT_BIGNUM, s->key.modulus, PKT_END);
3237 if (pktin->type == SSH1_SMSG_FAILURE) {
3238 c_write_str(ssh, "Server refused our public key.\r\n");
3239 continue; /* go and try password */
3241 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3242 bombout(("Bizarre response to offer of public key"));
3248 unsigned char buffer[32];
3249 Bignum challenge, response;
3251 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3252 bombout(("Server's RSA challenge was badly formatted"));
3255 response = rsadecrypt(challenge, &s->key);
3256 freebn(s->key.private_exponent);/* burn the evidence */
3258 for (i = 0; i < 32; i++) {
3259 buffer[i] = bignum_byte(response, 31 - i);
3263 MD5Update(&md5c, buffer, 32);
3264 MD5Update(&md5c, s->session_id, 16);
3265 MD5Final(buffer, &md5c);
3267 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3268 PKT_DATA, buffer, 16, PKT_END);
3275 if (pktin->type == SSH1_SMSG_FAILURE) {
3276 if (flags & FLAG_VERBOSE)
3277 c_write_str(ssh, "Failed to authenticate with"
3278 " our public key.\r\n");
3279 continue; /* go and try password */
3280 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3281 bombout(("Bizarre response to RSA authentication response"));
3285 break; /* we're through! */
3287 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3289 * Defence against traffic analysis: we send a
3290 * whole bunch of packets containing strings of
3291 * different lengths. One of these strings is the
3292 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3293 * The others are all random data in
3294 * SSH1_MSG_IGNORE packets. This way a passive
3295 * listener can't tell which is the password, and
3296 * hence can't deduce the password length.
3298 * Anybody with a password length greater than 16
3299 * bytes is going to have enough entropy in their
3300 * password that a listener won't find it _that_
3301 * much help to know how long it is. So what we'll
3304 * - if password length < 16, we send 15 packets
3305 * containing string lengths 1 through 15
3307 * - otherwise, we let N be the nearest multiple
3308 * of 8 below the password length, and send 8
3309 * packets containing string lengths N through
3310 * N+7. This won't obscure the order of
3311 * magnitude of the password length, but it will
3312 * introduce a bit of extra uncertainty.
3314 * A few servers (the old 1.2.18 through 1.2.22)
3315 * can't deal with SSH1_MSG_IGNORE. For these
3316 * servers, we need an alternative defence. We make
3317 * use of the fact that the password is interpreted
3318 * as a C string: so we can append a NUL, then some
3321 * One server (a Cisco one) can deal with neither
3322 * SSH1_MSG_IGNORE _nor_ a padded password string.
3323 * For this server we are left with no defences
3324 * against password length sniffing.
3326 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3328 * The server can deal with SSH1_MSG_IGNORE, so
3329 * we can use the primary defence.
3331 int bottom, top, pwlen, i;
3334 pwlen = strlen(s->password);
3336 bottom = 0; /* zero length passwords are OK! :-) */
3339 bottom = pwlen & ~7;
3343 assert(pwlen >= bottom && pwlen <= top);
3345 randomstr = snewn(top + 1, char);
3347 for (i = bottom; i <= top; i++) {
3349 defer_packet(ssh, s->pwpkt_type,
3350 PKTT_PASSWORD, PKT_STR, s->password,
3351 PKTT_OTHER, PKT_END);
3353 for (j = 0; j < i; j++) {
3355 randomstr[j] = random_byte();
3356 } while (randomstr[j] == '\0');
3358 randomstr[i] = '\0';
3359 defer_packet(ssh, SSH1_MSG_IGNORE,
3360 PKT_STR, randomstr, PKT_END);
3363 logevent("Sending password with camouflage packets");
3364 ssh_pkt_defersend(ssh);
3367 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3369 * The server can't deal with SSH1_MSG_IGNORE
3370 * but can deal with padded passwords, so we
3371 * can use the secondary defence.
3377 len = strlen(s->password);
3378 if (len < sizeof(string)) {
3380 strcpy(string, s->password);
3381 len++; /* cover the zero byte */
3382 while (len < sizeof(string)) {
3383 string[len++] = (char) random_byte();
3388 logevent("Sending length-padded password");
3389 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3390 PKT_INT, len, PKT_DATA, ss, len,
3391 PKTT_OTHER, PKT_END);
3394 * The server has _both_
3395 * BUG_CHOKES_ON_SSH1_IGNORE and
3396 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3397 * therefore nothing we can do.
3400 len = strlen(s->password);
3401 logevent("Sending unpadded password");
3402 send_packet(ssh, s->pwpkt_type,
3403 PKTT_PASSWORD, PKT_INT, len,
3404 PKT_DATA, s->password, len,
3405 PKTT_OTHER, PKT_END);
3408 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3409 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3412 logevent("Sent password");
3413 memset(s->password, 0, strlen(s->password));
3415 if (pktin->type == SSH1_SMSG_FAILURE) {
3416 if (flags & FLAG_VERBOSE)
3417 c_write_str(ssh, "Access denied\r\n");
3418 logevent("Authentication refused");
3419 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3420 bombout(("Strange packet received, type %d", pktin->type));
3425 logevent("Authentication successful");
3430 void sshfwd_close(struct ssh_channel *c)
3434 if (ssh->state != SSH_STATE_SESSION) {
3435 assert(ssh->state == SSH_STATE_CLOSED);
3439 if (c && !c->closes) {
3441 * If the channel's remoteid is -1, we have sent
3442 * CHANNEL_OPEN for this channel, but it hasn't even been
3443 * acknowledged by the server. So we must set a close flag
3444 * on it now, and then when the server acks the channel
3445 * open, we can close it then.
3447 if (((int)c->remoteid) != -1) {
3448 if (ssh->version == 1) {
3449 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3452 struct Packet *pktout;
3453 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3454 ssh2_pkt_adduint32(pktout, c->remoteid);
3455 ssh2_pkt_send(ssh, pktout);
3458 c->closes = 1; /* sent MSG_CLOSE */
3459 if (c->type == CHAN_X11) {
3461 logevent("Forwarded X11 connection terminated");
3462 } else if (c->type == CHAN_SOCKDATA ||
3463 c->type == CHAN_SOCKDATA_DORMANT) {
3465 logevent("Forwarded port closed");
3470 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3474 if (ssh->state != SSH_STATE_SESSION) {
3475 assert(ssh->state == SSH_STATE_CLOSED);
3479 if (ssh->version == 1) {
3480 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3481 PKT_INT, c->remoteid,
3483 PKT_INT, len, PKT_DATA, buf, len,
3484 PKTT_OTHER, PKT_END);
3486 * In SSH1 we can return 0 here - implying that forwarded
3487 * connections are never individually throttled - because
3488 * the only circumstance that can cause throttling will be
3489 * the whole SSH connection backing up, in which case
3490 * _everything_ will be throttled as a whole.
3494 ssh2_add_channel_data(c, buf, len);
3495 return ssh2_try_send(c);
3499 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3503 if (ssh->state != SSH_STATE_SESSION) {
3504 assert(ssh->state == SSH_STATE_CLOSED);
3508 if (ssh->version == 1) {
3509 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3510 c->v.v1.throttling = 0;
3511 ssh1_throttle(ssh, -1);
3514 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3518 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3520 struct queued_handler *qh = ssh->qhead;
3524 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3527 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3528 ssh->packet_dispatch[qh->msg1] = NULL;
3531 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3532 ssh->packet_dispatch[qh->msg2] = NULL;
3536 ssh->qhead = qh->next;
3538 if (ssh->qhead->msg1 > 0) {
3539 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3540 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3542 if (ssh->qhead->msg2 > 0) {
3543 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3544 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3547 ssh->qhead = ssh->qtail = NULL;
3548 ssh->packet_dispatch[pktin->type] = NULL;
3551 qh->handler(ssh, pktin, qh->ctx);
3556 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3557 chandler_fn_t handler, void *ctx)
3559 struct queued_handler *qh;
3561 qh = snew(struct queued_handler);
3564 qh->handler = handler;
3568 if (ssh->qtail == NULL) {
3572 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3573 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3576 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3577 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3580 ssh->qtail->next = qh;
3585 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3587 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3589 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3590 SSH2_MSG_REQUEST_SUCCESS)) {
3591 logeventf(ssh, "Remote port forwarding from %s enabled",
3594 logeventf(ssh, "Remote port forwarding from %s refused",
3597 rpf = del234(ssh->rportfwds, pf);
3599 sfree(pf->sportdesc);
3604 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3608 int sport,dport,sserv,dserv;
3609 char sports[256], dports[256], saddr[256], host[256];
3610 const char *portfwd_strptr;
3612 portfwd_strptr = cfg->portfwd;
3614 while (*portfwd_strptr) {
3615 type = *portfwd_strptr++;
3618 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3619 if (*portfwd_strptr == ':') {
3621 * We've seen a colon in the middle of the
3622 * source port number. This means that
3623 * everything we've seen until now is the
3624 * source _address_, so we'll move it into
3625 * saddr and start sports from the beginning
3630 if (ssh->version == 1 && type == 'R') {
3631 logeventf(ssh, "SSH1 cannot handle remote source address "
3632 "spec \"%s\"; ignoring", sports);
3634 strcpy(saddr, sports);
3637 if (n < 255) sports[n++] = *portfwd_strptr++;
3641 if (*portfwd_strptr == '\t')
3644 while (*portfwd_strptr && *portfwd_strptr != ':') {
3645 if (n < 255) host[n++] = *portfwd_strptr++;
3648 if (*portfwd_strptr == ':')
3651 while (*portfwd_strptr) {
3652 if (n < 255) dports[n++] = *portfwd_strptr++;
3656 dport = atoi(dports);
3660 dport = net_service_lookup(dports);
3662 logeventf(ssh, "Service lookup failed for destination"
3663 " port \"%s\"", dports);
3667 while (*portfwd_strptr) portfwd_strptr++;
3669 portfwd_strptr++; /* eat the NUL and move to next one */
3671 sport = atoi(sports);
3675 sport = net_service_lookup(sports);
3677 logeventf(ssh, "Service lookup failed for source"
3678 " port \"%s\"", sports);
3681 if (sport && dport) {
3682 /* Set up a description of the source port. */
3683 static char *sportdesc;
3684 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3685 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3686 (int)(*saddr?1:0), ":",
3687 (int)(sserv ? strlen(sports) : 0), sports,
3688 sserv, "(", sport, sserv, ")");
3690 /* Verbose description of the destination port */
3691 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3693 (int)(dserv ? strlen(dports) : 0), dports,
3694 dserv, "(", dport, dserv, ")");
3695 const char *err = pfd_addforward(host, dport,
3696 *saddr ? saddr : NULL,
3697 sport, ssh, &ssh->cfg);
3699 logeventf(ssh, "Local port %s forward to %s"
3700 " failed: %s", sportdesc, dportdesc, err);
3702 logeventf(ssh, "Local port %s forwarding to %s",
3703 sportdesc, dportdesc);
3706 } else if (type == 'D') {
3707 const char *err = pfd_addforward(NULL, -1,
3708 *saddr ? saddr : NULL,
3709 sport, ssh, &ssh->cfg);
3711 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3712 " setup failed: %s", sportdesc, err);
3714 logeventf(ssh, "Local port %s doing SOCKS"
3715 " dynamic forwarding", sportdesc);
3718 struct ssh_rportfwd *pf;
3721 * Ensure the remote port forwardings tree exists.
3723 if (!ssh->rportfwds) {
3724 if (ssh->version == 1)
3725 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3727 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3730 pf = snew(struct ssh_rportfwd);
3731 strcpy(pf->dhost, host);
3734 if (add234(ssh->rportfwds, pf) != pf) {
3735 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
3739 logeventf(ssh, "Requesting remote port %s"
3740 " forward to %s:%.*s%.*s%d%.*s",
3742 (int)(dserv ? strlen(dports) : 0), dports,
3743 dserv, "(", dport, dserv, ")");
3745 pf->sportdesc = sportdesc;
3748 if (ssh->version == 1) {
3749 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3754 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3756 ssh_rportfwd_succfail, pf);
3758 struct Packet *pktout;
3759 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3760 ssh2_pkt_addstring(pktout, "tcpip-forward");
3761 ssh2_pkt_addbool(pktout, 1);/* want reply */
3763 ssh2_pkt_addstring(pktout, saddr);
3764 } else if (ssh->cfg.rport_acceptall) {
3765 ssh2_pkt_addstring(pktout, "0.0.0.0");
3767 ssh2_pkt_addstring(pktout, "127.0.0.1");
3769 ssh2_pkt_adduint32(pktout, sport);
3770 ssh2_pkt_send(ssh, pktout);
3772 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3773 SSH2_MSG_REQUEST_FAILURE,
3774 ssh_rportfwd_succfail, pf);
3783 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3786 int stringlen, bufsize;
3788 ssh_pkt_getstring(pktin, &string, &stringlen);
3789 if (string == NULL) {
3790 bombout(("Incoming terminal data packet was badly formed"));
3794 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3796 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3797 ssh->v1_stdout_throttling = 1;
3798 ssh1_throttle(ssh, +1);
3802 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3804 /* Remote side is trying to open a channel to talk to our
3805 * X-Server. Give them back a local channel number. */
3806 struct ssh_channel *c;
3807 int remoteid = ssh_pkt_getuint32(pktin);
3809 logevent("Received X11 connect request");
3810 /* Refuse if X11 forwarding is disabled. */
3811 if (!ssh->X11_fwd_enabled) {
3812 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3813 PKT_INT, remoteid, PKT_END);
3814 logevent("Rejected X11 connect request");
3816 c = snew(struct ssh_channel);
3819 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3820 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3821 logevent("Opening X11 forward connection failed");
3823 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3824 PKT_INT, remoteid, PKT_END);
3827 ("Opening X11 forward connection succeeded");
3828 c->remoteid = remoteid;
3829 c->localid = alloc_channel_id(ssh);
3831 c->v.v1.throttling = 0;
3832 c->type = CHAN_X11; /* identify channel type */
3833 add234(ssh->channels, c);
3834 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3835 PKT_INT, c->remoteid, PKT_INT,
3836 c->localid, PKT_END);
3837 logevent("Opened X11 forward channel");
3842 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3844 /* Remote side is trying to open a channel to talk to our
3845 * agent. Give them back a local channel number. */
3846 struct ssh_channel *c;
3847 int remoteid = ssh_pkt_getuint32(pktin);
3849 /* Refuse if agent forwarding is disabled. */
3850 if (!ssh->agentfwd_enabled) {
3851 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3852 PKT_INT, remoteid, PKT_END);
3854 c = snew(struct ssh_channel);
3856 c->remoteid = remoteid;
3857 c->localid = alloc_channel_id(ssh);
3859 c->v.v1.throttling = 0;
3860 c->type = CHAN_AGENT; /* identify channel type */
3861 c->u.a.lensofar = 0;
3862 add234(ssh->channels, c);
3863 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3864 PKT_INT, c->remoteid, PKT_INT, c->localid,
3869 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3871 /* Remote side is trying to open a channel to talk to a
3872 * forwarded port. Give them back a local channel number. */
3873 struct ssh_channel *c;
3874 struct ssh_rportfwd pf;
3877 char *host, buf[1024];
3879 c = snew(struct ssh_channel);
3882 remoteid = ssh_pkt_getuint32(pktin);
3883 ssh_pkt_getstring(pktin, &host, &hostsize);
3884 port = ssh_pkt_getuint32(pktin);
3886 if (hostsize >= lenof(pf.dhost))
3887 hostsize = lenof(pf.dhost)-1;
3888 memcpy(pf.dhost, host, hostsize);
3889 pf.dhost[hostsize] = '\0';
3892 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3893 sprintf(buf, "Rejected remote port open request for %s:%d",
3896 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3897 PKT_INT, remoteid, PKT_END);
3899 sprintf(buf, "Received remote port open request for %s:%d",
3902 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3906 sprintf(buf, "Port open failed: %s", e);
3909 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3910 PKT_INT, remoteid, PKT_END);
3912 c->remoteid = remoteid;
3913 c->localid = alloc_channel_id(ssh);
3915 c->v.v1.throttling = 0;
3916 c->type = CHAN_SOCKDATA; /* identify channel type */
3917 add234(ssh->channels, c);
3918 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3919 PKT_INT, c->remoteid, PKT_INT,
3920 c->localid, PKT_END);
3921 logevent("Forwarded port opened successfully");
3926 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3928 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3929 unsigned int localid = ssh_pkt_getuint32(pktin);
3930 struct ssh_channel *c;
3932 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3933 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3934 c->remoteid = localid;
3935 c->type = CHAN_SOCKDATA;
3936 c->v.v1.throttling = 0;
3937 pfd_confirm(c->u.pfd.s);
3940 if (c && c->closes) {
3942 * We have a pending close on this channel,
3943 * which we decided on before the server acked
3944 * the channel open. So now we know the
3945 * remoteid, we can close it again.
3947 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3948 PKT_INT, c->remoteid, PKT_END);
3952 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3954 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3955 struct ssh_channel *c;
3957 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3958 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3959 logevent("Forwarded connection refused by server");
3960 pfd_close(c->u.pfd.s);
3961 del234(ssh->channels, c);
3966 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3968 /* Remote side closes a channel. */
3969 unsigned i = ssh_pkt_getuint32(pktin);
3970 struct ssh_channel *c;
3971 c = find234(ssh->channels, &i, ssh_channelfind);
3972 if (c && ((int)c->remoteid) != -1) {
3975 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3977 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3978 logevent("Forwarded X11 connection terminated");
3979 assert(c->u.x11.s != NULL);
3980 x11_close(c->u.x11.s);
3983 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3984 logevent("Forwarded port closed");
3985 assert(c->u.pfd.s != NULL);
3986 pfd_close(c->u.pfd.s);
3990 c->closes |= (closetype << 2); /* seen this message */
3991 if (!(c->closes & closetype)) {
3992 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3994 c->closes |= closetype; /* sent it too */
3997 if (c->closes == 15) {
3998 del234(ssh->channels, c);
4002 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4003 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4004 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4009 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4011 /* Data sent down one of our channels. */
4012 int i = ssh_pkt_getuint32(pktin);
4015 struct ssh_channel *c;
4017 ssh_pkt_getstring(pktin, &p, &len);
4019 c = find234(ssh->channels, &i, ssh_channelfind);
4024 bufsize = x11_send(c->u.x11.s, p, len);
4027 bufsize = pfd_send(c->u.pfd.s, p, len);
4030 /* Data for an agent message. Buffer it. */
4032 if (c->u.a.lensofar < 4) {
4033 int l = min(4 - c->u.a.lensofar, len);
4034 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4038 c->u.a.lensofar += l;
4040 if (c->u.a.lensofar == 4) {
4042 4 + GET_32BIT(c->u.a.msglen);
4043 c->u.a.message = snewn(c->u.a.totallen,
4045 memcpy(c->u.a.message, c->u.a.msglen, 4);
4047 if (c->u.a.lensofar >= 4 && len > 0) {
4049 min(c->u.a.totallen - c->u.a.lensofar,
4051 memcpy(c->u.a.message + c->u.a.lensofar, p,
4055 c->u.a.lensofar += l;
4057 if (c->u.a.lensofar == c->u.a.totallen) {
4060 if (agent_query(c->u.a.message,
4063 ssh_agentf_callback, c))
4064 ssh_agentf_callback(c, reply, replylen);
4065 sfree(c->u.a.message);
4066 c->u.a.lensofar = 0;
4069 bufsize = 0; /* agent channels never back up */
4072 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4073 c->v.v1.throttling = 1;
4074 ssh1_throttle(ssh, +1);
4079 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4082 ssh->exitcode = ssh_pkt_getuint32(pktin);
4083 sprintf(buf, "Server sent command exit status %d",
4086 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4088 * In case `helpful' firewalls or proxies tack
4089 * extra human-readable text on the end of the
4090 * session which we might mistake for another
4091 * encrypted packet, we close the session once
4092 * we've sent EXIT_CONFIRMATION.
4094 ssh_closing((Plug)ssh, NULL, 0, 0);
4097 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4098 struct Packet *pktin)
4100 crBegin(ssh->do_ssh1_connection_crstate);
4102 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4103 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4104 ssh1_smsg_stdout_stderr_data;
4106 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4107 ssh1_msg_channel_open_confirmation;
4108 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4109 ssh1_msg_channel_open_failure;
4110 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4111 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4112 ssh1_msg_channel_close;
4113 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4114 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4116 if (ssh->cfg.agentfwd && agent_exists()) {
4117 logevent("Requesting agent forwarding");
4118 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4122 if (pktin->type != SSH1_SMSG_SUCCESS
4123 && pktin->type != SSH1_SMSG_FAILURE) {
4124 bombout(("Protocol confusion"));
4126 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4127 logevent("Agent forwarding refused");
4129 logevent("Agent forwarding enabled");
4130 ssh->agentfwd_enabled = TRUE;
4131 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4135 if (ssh->cfg.x11_forward) {
4136 char proto[20], data[64];
4137 logevent("Requesting X11 forwarding");
4138 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4139 data, sizeof(data), ssh->cfg.x11_auth);
4140 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4141 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4142 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4143 PKT_STR, proto, PKT_STR, data,
4144 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4147 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4148 PKT_STR, proto, PKT_STR, data, PKT_END);
4153 if (pktin->type != SSH1_SMSG_SUCCESS
4154 && pktin->type != SSH1_SMSG_FAILURE) {
4155 bombout(("Protocol confusion"));
4157 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4158 logevent("X11 forwarding refused");
4160 logevent("X11 forwarding enabled");
4161 ssh->X11_fwd_enabled = TRUE;
4162 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4166 ssh_setup_portfwd(ssh, &ssh->cfg);
4167 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4169 if (!ssh->cfg.nopty) {
4170 /* Unpick the terminal-speed string. */
4171 /* XXX perhaps we should allow no speeds to be sent. */
4172 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4173 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4174 /* Send the pty request. */
4175 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4176 PKT_STR, ssh->cfg.termtype,
4177 PKT_INT, ssh->term_height,
4178 PKT_INT, ssh->term_width,
4179 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4180 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4181 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4182 PKT_CHAR, 0, PKT_END);
4183 ssh->state = SSH_STATE_INTERMED;
4187 if (pktin->type != SSH1_SMSG_SUCCESS
4188 && pktin->type != SSH1_SMSG_FAILURE) {
4189 bombout(("Protocol confusion"));
4191 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4192 c_write_str(ssh, "Server refused to allocate pty\r\n");
4193 ssh->editing = ssh->echoing = 1;
4195 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4196 ssh->ospeed, ssh->ispeed);
4198 ssh->editing = ssh->echoing = 1;
4201 if (ssh->cfg.compression) {
4202 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4206 if (pktin->type != SSH1_SMSG_SUCCESS
4207 && pktin->type != SSH1_SMSG_FAILURE) {
4208 bombout(("Protocol confusion"));
4210 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4211 c_write_str(ssh, "Server refused to compress\r\n");
4213 logevent("Started compression");
4214 ssh->v1_compressing = TRUE;
4215 ssh->cs_comp_ctx = zlib_compress_init();
4216 logevent("Initialised zlib (RFC1950) compression");
4217 ssh->sc_comp_ctx = zlib_decompress_init();
4218 logevent("Initialised zlib (RFC1950) decompression");
4222 * Start the shell or command.
4224 * Special case: if the first-choice command is an SSH2
4225 * subsystem (hence not usable here) and the second choice
4226 * exists, we fall straight back to that.
4229 char *cmd = ssh->cfg.remote_cmd_ptr;
4231 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4232 cmd = ssh->cfg.remote_cmd_ptr2;
4233 ssh->fallback_cmd = TRUE;
4236 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4238 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4239 logevent("Started session");
4242 ssh->state = SSH_STATE_SESSION;
4243 if (ssh->size_needed)
4244 ssh_size(ssh, ssh->term_width, ssh->term_height);
4245 if (ssh->eof_needed)
4246 ssh_special(ssh, TS_EOF);
4249 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4251 ssh->channels = newtree234(ssh_channelcmp);
4255 * By this point, most incoming packets are already being
4256 * handled by the dispatch table, and we need only pay
4257 * attention to the unusual ones.
4262 if (pktin->type == SSH1_SMSG_SUCCESS) {
4263 /* may be from EXEC_SHELL on some servers */
4264 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4265 /* may be from EXEC_SHELL on some servers
4266 * if no pty is available or in other odd cases. Ignore */
4268 bombout(("Strange packet received: type %d", pktin->type));
4273 int len = min(inlen, 512);
4274 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4275 PKT_INT, len, PKT_DATA, in, len,
4276 PKTT_OTHER, PKT_END);
4287 * Handle the top-level SSH2 protocol.
4289 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4294 ssh_pkt_getstring(pktin, &msg, &msglen);
4295 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4300 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4302 /* log reason code in disconnect message */
4306 ssh_pkt_getstring(pktin, &msg, &msglen);
4307 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4310 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4312 /* Do nothing, because we're ignoring it! Duhh. */
4315 static void ssh1_protocol_setup(Ssh ssh)
4320 * Most messages are handled by the coroutines.
4322 for (i = 0; i < 256; i++)
4323 ssh->packet_dispatch[i] = NULL;
4326 * These special message types we install handlers for.
4328 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4329 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4330 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4333 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4334 struct Packet *pktin)
4336 if (ssh->state == SSH_STATE_CLOSED)
4339 if (pktin && ssh->packet_dispatch[pktin->type]) {
4340 ssh->packet_dispatch[pktin->type](ssh, pktin);
4344 if (!ssh->protocol_initial_phase_done) {
4345 if (do_ssh1_login(ssh, in, inlen, pktin))
4346 ssh->protocol_initial_phase_done = TRUE;
4351 do_ssh1_connection(ssh, in, inlen, pktin);
4355 * Utility routine for decoding comma-separated strings in KEXINIT.
4357 static int in_commasep_string(char *needle, char *haystack, int haylen)
4360 if (!needle || !haystack) /* protect against null pointers */
4362 needlen = strlen(needle);
4365 * Is it at the start of the string?
4367 if (haylen >= needlen && /* haystack is long enough */
4368 !memcmp(needle, haystack, needlen) && /* initial match */
4369 (haylen == needlen || haystack[needlen] == ',')
4370 /* either , or EOS follows */
4374 * If not, search for the next comma and resume after that.
4375 * If no comma found, terminate.
4377 while (haylen > 0 && *haystack != ',')
4378 haylen--, haystack++;
4381 haylen--, haystack++; /* skip over comma itself */
4386 * SSH2 key creation method.
4388 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4389 unsigned char *sessid, char chr,
4390 unsigned char *keyspace)
4393 /* First 20 bytes. */
4395 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4397 SHA_Bytes(&s, H, 20);
4398 SHA_Bytes(&s, &chr, 1);
4399 SHA_Bytes(&s, sessid, 20);
4400 SHA_Final(&s, keyspace);
4401 /* Next 20 bytes. */
4403 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4405 SHA_Bytes(&s, H, 20);
4406 SHA_Bytes(&s, keyspace, 20);
4407 SHA_Final(&s, keyspace + 20);
4411 * Handle the SSH2 transport layer.
4413 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4414 struct Packet *pktin)
4416 struct do_ssh2_transport_state {
4417 int nbits, pbits, warn;
4418 Bignum p, g, e, f, K;
4419 int kex_init_value, kex_reply_value;
4420 const struct ssh_mac **maclist;
4422 const struct ssh2_cipher *cscipher_tobe;
4423 const struct ssh2_cipher *sccipher_tobe;
4424 const struct ssh_mac *csmac_tobe;
4425 const struct ssh_mac *scmac_tobe;
4426 const struct ssh_compress *cscomp_tobe;
4427 const struct ssh_compress *sccomp_tobe;
4428 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4429 int hostkeylen, siglen;
4430 void *hkey; /* actual host key */
4431 unsigned char exchange_hash[20];
4432 int n_preferred_kex;
4433 const struct ssh_kex *preferred_kex[KEX_MAX];
4434 int n_preferred_ciphers;
4435 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4436 const struct ssh_compress *preferred_comp;
4438 struct Packet *pktout;
4440 crState(do_ssh2_transport_state);
4442 crBegin(ssh->do_ssh2_transport_crstate);
4444 s->cscipher_tobe = s->sccipher_tobe = NULL;
4445 s->csmac_tobe = s->scmac_tobe = NULL;
4446 s->cscomp_tobe = s->sccomp_tobe = NULL;
4453 * Set up the preferred key exchange. (NULL => warn below here)
4455 s->n_preferred_kex = 0;
4456 for (i = 0; i < KEX_MAX; i++) {
4457 switch (ssh->cfg.ssh_kexlist[i]) {
4459 s->preferred_kex[s->n_preferred_kex++] =
4460 &ssh_diffiehellman_gex;
4463 s->preferred_kex[s->n_preferred_kex++] =
4464 &ssh_diffiehellman_group14;
4467 s->preferred_kex[s->n_preferred_kex++] =
4468 &ssh_diffiehellman_group1;
4471 /* Flag for later. Don't bother if it's the last in
4473 if (i < KEX_MAX - 1) {
4474 s->preferred_kex[s->n_preferred_kex++] = NULL;
4484 * Set up the preferred ciphers. (NULL => warn below here)
4486 s->n_preferred_ciphers = 0;
4487 for (i = 0; i < CIPHER_MAX; i++) {
4488 switch (ssh->cfg.ssh_cipherlist[i]) {
4489 case CIPHER_BLOWFISH:
4490 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4493 if (ssh->cfg.ssh2_des_cbc) {
4494 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4498 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4501 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4504 /* Flag for later. Don't bother if it's the last in
4506 if (i < CIPHER_MAX - 1) {
4507 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4515 * Set up preferred compression.
4517 if (ssh->cfg.compression)
4518 s->preferred_comp = &ssh_zlib;
4520 s->preferred_comp = &ssh_comp_none;
4523 * Be prepared to work around the buggy MAC problem.
4525 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4526 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4528 s->maclist = macs, s->nmacs = lenof(macs);
4532 int i, j, commalist_started;
4535 * Enable queueing of outgoing auth- or connection-layer
4536 * packets while we are in the middle of a key exchange.
4538 ssh->queueing = TRUE;
4541 * Flag that KEX is in progress.
4543 ssh->kex_in_progress = TRUE;
4546 * Construct and send our key exchange packet.
4548 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4549 for (i = 0; i < 16; i++)
4550 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4551 /* List key exchange algorithms. */
4552 ssh2_pkt_addstring_start(s->pktout);
4553 commalist_started = 0;
4554 for (i = 0; i < s->n_preferred_kex; i++) {
4555 const struct ssh_kex *k = s->preferred_kex[i];
4556 if (!k) continue; /* warning flag */
4557 if (commalist_started)
4558 ssh2_pkt_addstring_str(s->pktout, ",");
4559 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4560 commalist_started = 1;
4562 /* List server host key algorithms. */
4563 ssh2_pkt_addstring_start(s->pktout);
4564 for (i = 0; i < lenof(hostkey_algs); i++) {
4565 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4566 if (i < lenof(hostkey_algs) - 1)
4567 ssh2_pkt_addstring_str(s->pktout, ",");
4569 /* List client->server encryption algorithms. */
4570 ssh2_pkt_addstring_start(s->pktout);
4571 commalist_started = 0;
4572 for (i = 0; i < s->n_preferred_ciphers; i++) {
4573 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4574 if (!c) continue; /* warning flag */
4575 for (j = 0; j < c->nciphers; j++) {
4576 if (commalist_started)
4577 ssh2_pkt_addstring_str(s->pktout, ",");
4578 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4579 commalist_started = 1;
4582 /* List server->client encryption algorithms. */
4583 ssh2_pkt_addstring_start(s->pktout);
4584 commalist_started = 0;
4585 for (i = 0; i < s->n_preferred_ciphers; i++) {
4586 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4587 if (!c) continue; /* warning flag */
4588 for (j = 0; j < c->nciphers; j++) {
4589 if (commalist_started)
4590 ssh2_pkt_addstring_str(s->pktout, ",");
4591 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4592 commalist_started = 1;
4595 /* List client->server MAC algorithms. */
4596 ssh2_pkt_addstring_start(s->pktout);
4597 for (i = 0; i < s->nmacs; i++) {
4598 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4599 if (i < s->nmacs - 1)
4600 ssh2_pkt_addstring_str(s->pktout, ",");
4602 /* List server->client MAC algorithms. */
4603 ssh2_pkt_addstring_start(s->pktout);
4604 for (i = 0; i < s->nmacs; i++) {
4605 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4606 if (i < s->nmacs - 1)
4607 ssh2_pkt_addstring_str(s->pktout, ",");
4609 /* List client->server compression algorithms. */
4610 ssh2_pkt_addstring_start(s->pktout);
4611 assert(lenof(compressions) > 1);
4612 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4613 for (i = 0; i < lenof(compressions); i++) {
4614 const struct ssh_compress *c = compressions[i];
4615 if (c != s->preferred_comp) {
4616 ssh2_pkt_addstring_str(s->pktout, ",");
4617 ssh2_pkt_addstring_str(s->pktout, c->name);
4620 /* List server->client compression algorithms. */
4621 ssh2_pkt_addstring_start(s->pktout);
4622 assert(lenof(compressions) > 1);
4623 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4624 for (i = 0; i < lenof(compressions); i++) {
4625 const struct ssh_compress *c = compressions[i];
4626 if (c != s->preferred_comp) {
4627 ssh2_pkt_addstring_str(s->pktout, ",");
4628 ssh2_pkt_addstring_str(s->pktout, c->name);
4631 /* List client->server languages. Empty list. */
4632 ssh2_pkt_addstring_start(s->pktout);
4633 /* List server->client languages. Empty list. */
4634 ssh2_pkt_addstring_start(s->pktout);
4635 /* First KEX packet does _not_ follow, because we're not that brave. */
4636 ssh2_pkt_addbool(s->pktout, FALSE);
4638 ssh2_pkt_adduint32(s->pktout, 0);
4641 ssh->exhash = ssh->exhashbase;
4642 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4644 ssh2_pkt_send_noqueue(ssh, s->pktout);
4648 if (pktin->length > 5)
4649 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4652 * Now examine the other side's KEXINIT to see what we're up
4659 if (pktin->type != SSH2_MSG_KEXINIT) {
4660 bombout(("expected key exchange packet from server"));
4664 ssh->hostkey = NULL;
4665 s->cscipher_tobe = NULL;
4666 s->sccipher_tobe = NULL;
4667 s->csmac_tobe = NULL;
4668 s->scmac_tobe = NULL;
4669 s->cscomp_tobe = NULL;
4670 s->sccomp_tobe = NULL;
4671 pktin->savedpos += 16; /* skip garbage cookie */
4672 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4674 for (i = 0; i < s->n_preferred_kex; i++) {
4675 const struct ssh_kex *k = s->preferred_kex[i];
4678 } else if (in_commasep_string(k->name, str, len)) {
4683 askalg(ssh->frontend, "key-exchange algorithm",
4689 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4690 str ? str : "(null)"));
4693 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4694 for (i = 0; i < lenof(hostkey_algs); i++) {
4695 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4696 ssh->hostkey = hostkey_algs[i];
4700 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4702 for (i = 0; i < s->n_preferred_ciphers; i++) {
4703 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4707 for (j = 0; j < c->nciphers; j++) {
4708 if (in_commasep_string(c->list[j]->name, str, len)) {
4709 s->cscipher_tobe = c->list[j];
4714 if (s->cscipher_tobe) {
4716 askalg(ssh->frontend, "client-to-server cipher",
4717 s->cscipher_tobe->name);
4721 if (!s->cscipher_tobe) {
4722 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4723 str ? str : "(null)"));
4727 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4729 for (i = 0; i < s->n_preferred_ciphers; i++) {
4730 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4734 for (j = 0; j < c->nciphers; j++) {
4735 if (in_commasep_string(c->list[j]->name, str, len)) {
4736 s->sccipher_tobe = c->list[j];
4741 if (s->sccipher_tobe) {
4743 askalg(ssh->frontend, "server-to-client cipher",
4744 s->sccipher_tobe->name);
4748 if (!s->sccipher_tobe) {
4749 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4750 str ? str : "(null)"));
4754 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4755 for (i = 0; i < s->nmacs; i++) {
4756 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4757 s->csmac_tobe = s->maclist[i];
4761 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4762 for (i = 0; i < s->nmacs; i++) {
4763 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4764 s->scmac_tobe = s->maclist[i];
4768 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4769 for (i = 0; i < lenof(compressions) + 1; i++) {
4770 const struct ssh_compress *c =
4771 i == 0 ? s->preferred_comp : compressions[i - 1];
4772 if (in_commasep_string(c->name, str, len)) {
4777 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
4778 for (i = 0; i < lenof(compressions) + 1; i++) {
4779 const struct ssh_compress *c =
4780 i == 0 ? s->preferred_comp : compressions[i - 1];
4781 if (in_commasep_string(c->name, str, len)) {
4789 * Work out the number of bits of key we will need from the key
4790 * exchange. We start with the maximum key length of either
4796 csbits = s->cscipher_tobe->keylen;
4797 scbits = s->sccipher_tobe->keylen;
4798 s->nbits = (csbits > scbits ? csbits : scbits);
4800 /* The keys only have 160-bit entropy, since they're based on
4801 * a SHA-1 hash. So cap the key size at 160 bits. */
4806 * If we're doing Diffie-Hellman group exchange, start by
4807 * requesting a group.
4809 if (!ssh->kex->pdata) {
4810 logevent("Doing Diffie-Hellman group exchange");
4811 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4813 * Work out how big a DH group we will need to allow that
4816 s->pbits = 512 << ((s->nbits - 1) / 64);
4817 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4818 ssh2_pkt_adduint32(s->pktout, s->pbits);
4819 ssh2_pkt_send_noqueue(ssh, s->pktout);
4822 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4823 bombout(("expected key exchange group packet from server"));
4826 s->p = ssh2_pkt_getmp(pktin);
4827 s->g = ssh2_pkt_getmp(pktin);
4828 if (!s->p || !s->g) {
4829 bombout(("unable to read mp-ints from incoming group packet"));
4832 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
4833 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4834 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4836 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
4837 ssh->kex_ctx = dh_setup_group(ssh->kex);
4838 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4839 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4840 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
4841 ssh->kex->groupname);
4844 logevent("Doing Diffie-Hellman key exchange");
4846 * Now generate and send e for Diffie-Hellman.
4848 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4849 s->pktout = ssh2_pkt_init(s->kex_init_value);
4850 ssh2_pkt_addmp(s->pktout, s->e);
4851 ssh2_pkt_send_noqueue(ssh, s->pktout);
4854 if (pktin->type != s->kex_reply_value) {
4855 bombout(("expected key exchange reply packet from server"));
4858 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4859 s->f = ssh2_pkt_getmp(pktin);
4861 bombout(("unable to parse key exchange reply packet"));
4864 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
4866 s->K = dh_find_K(ssh->kex_ctx, s->f);
4868 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4869 if (ssh->kex == &ssh_diffiehellman_gex) {
4870 sha_uint32(&ssh->exhash, s->pbits);
4871 sha_mpint(&ssh->exhash, s->p);
4872 sha_mpint(&ssh->exhash, s->g);
4874 sha_mpint(&ssh->exhash, s->e);
4875 sha_mpint(&ssh->exhash, s->f);
4876 sha_mpint(&ssh->exhash, s->K);
4877 SHA_Final(&ssh->exhash, s->exchange_hash);
4879 dh_cleanup(ssh->kex_ctx);
4880 ssh->kex_ctx = NULL;
4883 debug(("Exchange hash is:\n"));
4884 dmemdump(s->exchange_hash, 20);
4887 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4889 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4890 (char *)s->exchange_hash, 20)) {
4891 bombout(("Server's host key did not match the signature supplied"));
4896 * Authenticate remote host: verify host key. (We've already
4897 * checked the signature of the exchange hash.)
4899 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4900 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4901 verify_ssh_host_key(ssh->frontend,
4902 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4903 s->keystr, s->fingerprint);
4904 if (s->first_kex) { /* don't bother logging this in rekeys */
4905 logevent("Host key fingerprint is:");
4906 logevent(s->fingerprint);
4908 sfree(s->fingerprint);
4910 ssh->hostkey->freekey(s->hkey);
4913 * The exchange hash from the very first key exchange is also
4914 * the session id, used in session key construction and
4918 memcpy(ssh->v2_session_id, s->exchange_hash,
4919 sizeof(s->exchange_hash));
4922 * Send SSH2_MSG_NEWKEYS.
4924 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
4925 ssh2_pkt_send_noqueue(ssh, s->pktout);
4926 ssh->outgoing_data_size = 0; /* start counting from here */
4929 * We've sent client NEWKEYS, so create and initialise
4930 * client-to-server session keys.
4932 if (ssh->cs_cipher_ctx)
4933 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4934 ssh->cscipher = s->cscipher_tobe;
4935 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4937 if (ssh->cs_mac_ctx)
4938 ssh->csmac->free_context(ssh->cs_mac_ctx);
4939 ssh->csmac = s->csmac_tobe;
4940 ssh->cs_mac_ctx = ssh->csmac->make_context();
4942 if (ssh->cs_comp_ctx)
4943 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4944 ssh->cscomp = s->cscomp_tobe;
4945 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4948 * Set IVs on client-to-server keys. Here we use the exchange
4949 * hash from the _first_ key exchange.
4952 unsigned char keyspace[40];
4953 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4954 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4955 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4956 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4957 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4958 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4961 logeventf(ssh, "Initialised %.200s client->server encryption",
4962 ssh->cscipher->text_name);
4963 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4964 ssh->csmac->text_name);
4965 if (ssh->cscomp->text_name)
4966 logeventf(ssh, "Initialised %s compression",
4967 ssh->cscomp->text_name);
4970 * Now our end of the key exchange is complete, we can send all
4971 * our queued higher-layer packets.
4973 ssh->queueing = FALSE;
4974 ssh2_pkt_queuesend(ssh);
4977 * Expect SSH2_MSG_NEWKEYS from server.
4980 if (pktin->type != SSH2_MSG_NEWKEYS) {
4981 bombout(("expected new-keys packet from server"));
4984 ssh->incoming_data_size = 0; /* start counting from here */
4987 * We've seen server NEWKEYS, so create and initialise
4988 * server-to-client session keys.
4990 if (ssh->sc_cipher_ctx)
4991 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4992 ssh->sccipher = s->sccipher_tobe;
4993 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4995 if (ssh->sc_mac_ctx)
4996 ssh->scmac->free_context(ssh->sc_mac_ctx);
4997 ssh->scmac = s->scmac_tobe;
4998 ssh->sc_mac_ctx = ssh->scmac->make_context();
5000 if (ssh->sc_comp_ctx)
5001 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5002 ssh->sccomp = s->sccomp_tobe;
5003 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5006 * Set IVs on server-to-client keys. Here we use the exchange
5007 * hash from the _first_ key exchange.
5010 unsigned char keyspace[40];
5011 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5012 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5013 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5014 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5015 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5016 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5018 logeventf(ssh, "Initialised %.200s server->client encryption",
5019 ssh->sccipher->text_name);
5020 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5021 ssh->scmac->text_name);
5022 if (ssh->sccomp->text_name)
5023 logeventf(ssh, "Initialised %s decompression",
5024 ssh->sccomp->text_name);
5027 * Free key exchange data.
5031 if (ssh->kex == &ssh_diffiehellman_gex) {
5037 * Key exchange is over. Schedule a timer for our next rekey.
5039 ssh->kex_in_progress = FALSE;
5040 if (ssh->cfg.ssh_rekey_time != 0)
5041 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5045 * If this is the first key exchange phase, we must pass the
5046 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5047 * wants to see it but because it will need time to initialise
5048 * itself before it sees an actual packet. In subsequent key
5049 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5050 * it would only confuse the layer above.
5052 if (!s->first_kex) {
5058 * Now we're encrypting. Begin returning 1 to the protocol main
5059 * function so that other things can run on top of the
5060 * transport. If we ever see a KEXINIT, we must go back to the
5063 * We _also_ go back to the start if we see pktin==NULL and
5064 * inlen==-1, because this is a special signal meaning
5065 * `initiate client-driven rekey', and `in' contains a message
5066 * giving the reason for the rekey.
5068 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5069 (!pktin && inlen == -1))) {
5073 logevent("Server initiated key re-exchange");
5075 logevent((char *)in);
5077 goto begin_key_exchange;
5083 * Add data to an SSH2 channel output buffer.
5085 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5088 bufchain_add(&c->v.v2.outbuffer, buf, len);
5092 * Attempt to send data on an SSH2 channel.
5094 static int ssh2_try_send(struct ssh_channel *c)
5097 struct Packet *pktout;
5099 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5102 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5103 if ((unsigned)len > c->v.v2.remwindow)
5104 len = c->v.v2.remwindow;
5105 if ((unsigned)len > c->v.v2.remmaxpkt)
5106 len = c->v.v2.remmaxpkt;
5107 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5108 ssh2_pkt_adduint32(pktout, c->remoteid);
5109 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5110 ssh2_pkt_addstring_start(pktout);
5111 ssh2_pkt_addstring_data(pktout, data, len);
5112 end_log_omission(ssh, pktout);
5113 ssh2_pkt_send(ssh, pktout);
5114 bufchain_consume(&c->v.v2.outbuffer, len);
5115 c->v.v2.remwindow -= len;
5119 * After having sent as much data as we can, return the amount
5122 return bufchain_size(&c->v.v2.outbuffer);
5126 * Potentially enlarge the window on an SSH2 channel.
5128 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5133 * Never send WINDOW_ADJUST for a channel that the remote side
5134 * already thinks it's closed; there's no point, since it won't
5135 * be sending any more data anyway.
5140 if (newwin > c->v.v2.locwindow) {
5141 struct Packet *pktout;
5143 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5144 ssh2_pkt_adduint32(pktout, c->remoteid);
5145 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5146 ssh2_pkt_send(ssh, pktout);
5147 c->v.v2.locwindow = newwin;
5151 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5153 unsigned i = ssh_pkt_getuint32(pktin);
5154 struct ssh_channel *c;
5155 c = find234(ssh->channels, &i, ssh_channelfind);
5156 if (c && !c->closes)
5157 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5160 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5164 unsigned i = ssh_pkt_getuint32(pktin);
5165 struct ssh_channel *c;
5166 c = find234(ssh->channels, &i, ssh_channelfind);
5168 return; /* nonexistent channel */
5169 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5170 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5171 return; /* extended but not stderr */
5172 ssh_pkt_getstring(pktin, &data, &length);
5175 c->v.v2.locwindow -= length;
5177 case CHAN_MAINSESSION:
5179 from_backend(ssh->frontend, pktin->type ==
5180 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5184 bufsize = x11_send(c->u.x11.s, data, length);
5187 bufsize = pfd_send(c->u.pfd.s, data, length);
5190 while (length > 0) {
5191 if (c->u.a.lensofar < 4) {
5192 int l = min(4 - c->u.a.lensofar, length);
5193 memcpy(c->u.a.msglen + c->u.a.lensofar,
5197 c->u.a.lensofar += l;
5199 if (c->u.a.lensofar == 4) {
5201 4 + GET_32BIT(c->u.a.msglen);
5202 c->u.a.message = snewn(c->u.a.totallen,
5204 memcpy(c->u.a.message, c->u.a.msglen, 4);
5206 if (c->u.a.lensofar >= 4 && length > 0) {
5208 min(c->u.a.totallen - c->u.a.lensofar,
5210 memcpy(c->u.a.message + c->u.a.lensofar,
5214 c->u.a.lensofar += l;
5216 if (c->u.a.lensofar == c->u.a.totallen) {
5219 if (agent_query(c->u.a.message,
5222 ssh_agentf_callback, c))
5223 ssh_agentf_callback(c, reply, replylen);
5224 sfree(c->u.a.message);
5225 c->u.a.lensofar = 0;
5232 * If we are not buffering too much data,
5233 * enlarge the window again at the remote side.
5235 if (bufsize < OUR_V2_WINSIZE)
5236 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5240 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5242 unsigned i = ssh_pkt_getuint32(pktin);
5243 struct ssh_channel *c;
5245 c = find234(ssh->channels, &i, ssh_channelfind);
5247 return; /* nonexistent channel */
5249 if (c->type == CHAN_X11) {
5251 * Remote EOF on an X11 channel means we should
5252 * wrap up and close the channel ourselves.
5254 x11_close(c->u.x11.s);
5256 } else if (c->type == CHAN_AGENT) {
5258 } else if (c->type == CHAN_SOCKDATA) {
5259 pfd_close(c->u.pfd.s);
5264 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5266 unsigned i = ssh_pkt_getuint32(pktin);
5267 struct ssh_channel *c;
5268 struct Packet *pktout;
5270 c = find234(ssh->channels, &i, ssh_channelfind);
5271 if (!c || ((int)c->remoteid) == -1) {
5272 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5273 c ? "half-open" : "nonexistent", i));
5276 /* Do pre-close processing on the channel. */
5278 case CHAN_MAINSESSION:
5279 ssh->mainchan = NULL;
5280 update_specials_menu(ssh->frontend);
5283 if (c->u.x11.s != NULL)
5284 x11_close(c->u.x11.s);
5291 if (c->u.pfd.s != NULL)
5292 pfd_close(c->u.pfd.s);
5296 if (c->closes == 0) {
5297 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5298 ssh2_pkt_adduint32(pktout, c->remoteid);
5299 ssh2_pkt_send(ssh, pktout);
5301 del234(ssh->channels, c);
5302 bufchain_clear(&c->v.v2.outbuffer);
5306 * See if that was the last channel left open.
5307 * (This is only our termination condition if we're
5308 * not running in -N mode.)
5310 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5311 logevent("All channels closed. Disconnecting");
5314 * We used to send SSH_MSG_DISCONNECT here,
5315 * because I'd believed that _every_ conforming
5316 * SSH2 connection had to end with a disconnect
5317 * being sent by at least one side; apparently
5318 * I was wrong and it's perfectly OK to
5319 * unceremoniously slam the connection shut
5320 * when you're done, and indeed OpenSSH feels
5321 * this is more polite than sending a
5322 * DISCONNECT. So now we don't.
5324 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5325 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5326 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5327 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5328 ssh2_pkt_send_noqueue(ssh, s->pktout);
5330 ssh_closing((Plug)ssh, NULL, 0, 0);
5334 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5336 unsigned i = ssh_pkt_getuint32(pktin);
5337 struct ssh_channel *c;
5338 struct Packet *pktout;
5340 c = find234(ssh->channels, &i, ssh_channelfind);
5342 return; /* nonexistent channel */
5343 if (c->type != CHAN_SOCKDATA_DORMANT)
5344 return; /* dunno why they're confirming this */
5345 c->remoteid = ssh_pkt_getuint32(pktin);
5346 c->type = CHAN_SOCKDATA;
5347 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5348 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5350 pfd_confirm(c->u.pfd.s);
5353 * We have a pending close on this channel,
5354 * which we decided on before the server acked
5355 * the channel open. So now we know the
5356 * remoteid, we can close it again.
5358 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5359 ssh2_pkt_adduint32(pktout, c->remoteid);
5360 ssh2_pkt_send(ssh, pktout);
5364 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5366 static const char *const reasons[] = {
5367 "<unknown reason code>",
5368 "Administratively prohibited",
5370 "Unknown channel type",
5371 "Resource shortage",
5373 unsigned i = ssh_pkt_getuint32(pktin);
5374 unsigned reason_code;
5375 char *reason_string;
5378 struct ssh_channel *c;
5379 c = find234(ssh->channels, &i, ssh_channelfind);
5381 return; /* nonexistent channel */
5382 if (c->type != CHAN_SOCKDATA_DORMANT)
5383 return; /* dunno why they're failing this */
5385 reason_code = ssh_pkt_getuint32(pktin);
5386 if (reason_code >= lenof(reasons))
5387 reason_code = 0; /* ensure reasons[reason_code] in range */
5388 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5389 message = dupprintf("Forwarded connection refused by"
5390 " server: %s [%.*s]", reasons[reason_code],
5391 reason_length, reason_string);
5395 pfd_close(c->u.pfd.s);
5397 del234(ssh->channels, c);
5401 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5405 int typelen, want_reply;
5406 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5407 struct ssh_channel *c;
5408 struct Packet *pktout;
5410 localid = ssh_pkt_getuint32(pktin);
5411 ssh_pkt_getstring(pktin, &type, &typelen);
5412 want_reply = ssh2_pkt_getbool(pktin);
5415 * First, check that the channel exists. Otherwise,
5416 * we can instantly disconnect with a rude message.
5418 c = find234(ssh->channels, &localid, ssh_channelfind);
5421 sprintf(buf, "Received channel request for nonexistent"
5422 " channel %d", localid);
5424 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5425 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5426 ssh2_pkt_addstring(pktout, buf);
5427 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5428 ssh2_pkt_send_noqueue(ssh, pktout);
5429 connection_fatal(ssh->frontend, "%s", buf);
5430 ssh_closing((Plug)ssh, NULL, 0, 0);
5435 * Having got the channel number, we now look at
5436 * the request type string to see if it's something
5439 if (c == ssh->mainchan) {
5441 * We recognise "exit-status" and "exit-signal" on
5442 * the primary channel.
5444 if (typelen == 11 &&
5445 !memcmp(type, "exit-status", 11)) {
5447 ssh->exitcode = ssh_pkt_getuint32(pktin);
5448 logeventf(ssh, "Server sent command exit status %d",
5450 reply = SSH2_MSG_CHANNEL_SUCCESS;
5452 } else if (typelen == 11 &&
5453 !memcmp(type, "exit-signal", 11)) {
5455 int is_plausible = TRUE, is_int = FALSE;
5456 char *fmt_sig = "", *fmt_msg = "";
5458 int msglen = 0, core = FALSE;
5459 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5460 * provide an `int' for the signal, despite its
5461 * having been a `string' in the drafts since at
5462 * least 2001. (Fixed in session.c 1.147.) Try to
5463 * infer which we can safely parse it as. */
5465 unsigned char *p = pktin->body +
5467 long len = pktin->length - pktin->savedpos;
5468 unsigned long num = GET_32BIT(p); /* what is it? */
5469 /* If it's 0, it hardly matters; assume string */
5473 int maybe_int = FALSE, maybe_str = FALSE;
5474 #define CHECK_HYPOTHESIS(offset, result) \
5477 if (q >= 0 && q+4 <= len) { \
5478 q = q + 4 + GET_32BIT(p+q); \
5479 if (q >= 0 && q+4 <= len && \
5480 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5484 CHECK_HYPOTHESIS(4+1, maybe_int);
5485 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5486 #undef CHECK_HYPOTHESIS
5487 if (maybe_int && !maybe_str)
5489 else if (!maybe_int && maybe_str)
5492 /* Crikey. Either or neither. Panic. */
5493 is_plausible = FALSE;
5498 /* Old non-standard OpenSSH. */
5499 int signum = ssh_pkt_getuint32(pktin);
5500 fmt_sig = dupprintf(" %d", signum);
5502 /* As per the drafts. */
5505 ssh_pkt_getstring(pktin, &sig, &siglen);
5506 /* Signal name isn't supposed to be blank, but
5507 * let's cope gracefully if it is. */
5509 fmt_sig = dupprintf(" \"%.*s\"",
5513 core = ssh2_pkt_getbool(pktin);
5514 ssh_pkt_getstring(pktin, &msg, &msglen);
5516 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5518 /* ignore lang tag */
5519 } /* else don't attempt to parse */
5520 logeventf(ssh, "Server exited on signal%s%s%s",
5521 fmt_sig, core ? " (core dumped)" : "",
5523 if (*fmt_sig) sfree(fmt_sig);
5524 if (*fmt_msg) sfree(fmt_msg);
5525 reply = SSH2_MSG_CHANNEL_SUCCESS;
5530 * This is a channel request we don't know
5531 * about, so we now either ignore the request
5532 * or respond with CHANNEL_FAILURE, depending
5535 reply = SSH2_MSG_CHANNEL_FAILURE;
5538 pktout = ssh2_pkt_init(reply);
5539 ssh2_pkt_adduint32(pktout, c->remoteid);
5540 ssh2_pkt_send(ssh, pktout);
5544 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5547 int typelen, want_reply;
5548 struct Packet *pktout;
5550 ssh_pkt_getstring(pktin, &type, &typelen);
5551 want_reply = ssh2_pkt_getbool(pktin);
5554 * We currently don't support any global requests
5555 * at all, so we either ignore the request or
5556 * respond with REQUEST_FAILURE, depending on
5560 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5561 ssh2_pkt_send(ssh, pktout);
5565 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5573 struct ssh_channel *c;
5574 unsigned remid, winsize, pktsize;
5575 struct Packet *pktout;
5577 ssh_pkt_getstring(pktin, &type, &typelen);
5578 c = snew(struct ssh_channel);
5581 remid = ssh_pkt_getuint32(pktin);
5582 winsize = ssh_pkt_getuint32(pktin);
5583 pktsize = ssh_pkt_getuint32(pktin);
5585 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5588 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5589 addrstr = snewn(peeraddrlen+1, char);
5590 memcpy(addrstr, peeraddr, peeraddrlen);
5591 addrstr[peeraddrlen] = '\0';
5592 peerport = ssh_pkt_getuint32(pktin);
5594 logeventf(ssh, "Received X11 connect request from %s:%d",
5597 if (!ssh->X11_fwd_enabled)
5598 error = "X11 forwarding is not enabled";
5599 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5600 ssh->x11auth, addrstr, peerport,
5601 &ssh->cfg) != NULL) {
5602 error = "Unable to open an X11 connection";
5604 logevent("Opening X11 forward connection succeeded");
5609 } else if (typelen == 15 &&
5610 !memcmp(type, "forwarded-tcpip", 15)) {
5611 struct ssh_rportfwd pf, *realpf;
5614 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5615 pf.sport = ssh_pkt_getuint32(pktin);
5616 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5617 peerport = ssh_pkt_getuint32(pktin);
5618 realpf = find234(ssh->rportfwds, &pf, NULL);
5619 logeventf(ssh, "Received remote port %d open request "
5620 "from %s:%d", pf.sport, peeraddr, peerport);
5621 if (realpf == NULL) {
5622 error = "Remote port is not recognised";
5624 const char *e = pfd_newconnect(&c->u.pfd.s,
5628 logeventf(ssh, "Attempting to forward remote port to "
5629 "%s:%d", realpf->dhost, realpf->dport);
5631 logeventf(ssh, "Port open failed: %s", e);
5632 error = "Port open failed";
5634 logevent("Forwarded port opened successfully");
5635 c->type = CHAN_SOCKDATA;
5638 } else if (typelen == 22 &&
5639 !memcmp(type, "auth-agent@openssh.com", 3)) {
5640 if (!ssh->agentfwd_enabled)
5641 error = "Agent forwarding is not enabled";
5643 c->type = CHAN_AGENT; /* identify channel type */
5644 c->u.a.lensofar = 0;
5647 error = "Unsupported channel type requested";
5650 c->remoteid = remid;
5652 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5653 ssh2_pkt_adduint32(pktout, c->remoteid);
5654 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5655 ssh2_pkt_addstring(pktout, error);
5656 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5657 ssh2_pkt_send(ssh, pktout);
5658 logeventf(ssh, "Rejected channel open: %s", error);
5661 c->localid = alloc_channel_id(ssh);
5663 c->v.v2.locwindow = OUR_V2_WINSIZE;
5664 c->v.v2.remwindow = winsize;
5665 c->v.v2.remmaxpkt = pktsize;
5666 bufchain_init(&c->v.v2.outbuffer);
5667 add234(ssh->channels, c);
5668 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5669 ssh2_pkt_adduint32(pktout, c->remoteid);
5670 ssh2_pkt_adduint32(pktout, c->localid);
5671 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5672 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5673 ssh2_pkt_send(ssh, pktout);
5678 * Handle the SSH2 userauth and connection layers.
5680 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5681 struct Packet *pktin)
5683 struct do_ssh2_authconn_state {
5685 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5687 AUTH_KEYBOARD_INTERACTIVE
5691 AUTH_TYPE_PUBLICKEY,
5692 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5693 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5695 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5696 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5698 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5699 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5700 int kbd_inter_running;
5702 int num_prompts, curr_prompt, echo;
5707 void *publickey_blob;
5708 int publickey_bloblen;
5709 unsigned char request[5], *response, *p;
5713 char *pkblob, *alg, *commentp;
5714 int pklen, alglen, commentlen;
5715 int siglen, retlen, len;
5716 char *q, *agentreq, *ret;
5718 int num_env, env_left, env_ok;
5719 struct Packet *pktout;
5721 crState(do_ssh2_authconn_state);
5723 crBegin(ssh->do_ssh2_authconn_crstate);
5726 * Request userauth protocol, and await a response to it.
5728 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5729 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5730 ssh2_pkt_send(ssh, s->pktout);
5731 crWaitUntilV(pktin);
5732 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5733 bombout(("Server refused user authentication protocol"));
5738 * We repeat this whole loop, including the username prompt,
5739 * until we manage a successful authentication. If the user
5740 * types the wrong _password_, they can be sent back to the
5741 * beginning to try another username, if this is configured on.
5742 * (If they specify a username in the config, they are never
5743 * asked, even if they do give a wrong password.)
5745 * I think this best serves the needs of
5747 * - the people who have no configuration, no keys, and just
5748 * want to try repeated (username,password) pairs until they
5749 * type both correctly
5751 * - people who have keys and configuration but occasionally
5752 * need to fall back to passwords
5754 * - people with a key held in Pageant, who might not have
5755 * logged in to a particular machine before; so they want to
5756 * type a username, and then _either_ their key will be
5757 * accepted, _or_ they will type a password. If they mistype
5758 * the username they will want to be able to get back and
5761 s->username[0] = '\0';
5762 s->got_username = FALSE;
5767 if (s->got_username && !ssh->cfg.change_username) {
5769 * We got a username last time round this loop, and
5770 * with change_username turned off we don't try to get
5773 } else if (!*ssh->cfg.username) {
5774 if (ssh_get_line && !ssh_getline_pw_only) {
5775 if (!ssh_get_line("login as: ",
5776 s->username, sizeof(s->username), FALSE)) {
5778 * get_line failed to get a username.
5781 logevent("No username provided. Abandoning session.");
5782 ssh_closing((Plug)ssh, NULL, 0, 0);
5786 int ret; /* need not be saved across crReturn */
5787 c_write_str(ssh, "login as: ");
5789 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
5791 crWaitUntilV(!pktin);
5792 ret = process_userpass_input(ssh, in, inlen);
5796 c_write_str(ssh, "\r\n");
5798 s->username[strcspn(s->username, "\n\r")] = '\0';
5801 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
5802 s->username[sizeof(s->username)-1] = '\0';
5803 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
5804 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
5805 c_write_str(ssh, stuff);
5809 s->got_username = TRUE;
5812 * Send an authentication request using method "none": (a)
5813 * just in case it succeeds, and (b) so that we know what
5814 * authentication methods we can usefully try next.
5816 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5818 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5819 ssh2_pkt_addstring(s->pktout, s->username);
5820 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5821 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5822 ssh2_pkt_send(ssh, s->pktout);
5823 s->type = AUTH_TYPE_NONE;
5825 s->we_are_in = FALSE;
5827 s->tried_pubkey_config = FALSE;
5828 s->tried_agent = FALSE;
5829 s->tried_keyb_inter = FALSE;
5830 s->kbd_inter_running = FALSE;
5831 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
5832 if (!filename_is_null(ssh->cfg.keyfile)) {
5834 logeventf(ssh, "Reading private key file \"%.150s\"",
5835 filename_to_str(&ssh->cfg.keyfile));
5836 keytype = key_type(&ssh->cfg.keyfile);
5837 if (keytype == SSH_KEYTYPE_SSH2) {
5839 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
5840 &s->publickey_bloblen, NULL);
5843 logeventf(ssh, "Unable to use this key file (%s)",
5844 key_type_to_str(keytype));
5845 msgbuf = dupprintf("Unable to use key file \"%.150s\""
5847 filename_to_str(&ssh->cfg.keyfile),
5848 key_type_to_str(keytype));
5849 c_write_str(ssh, msgbuf);
5851 s->publickey_blob = NULL;
5854 s->publickey_blob = NULL;
5858 * Wait for the result of the last authentication request.
5861 crWaitUntilV(pktin);
5862 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
5866 * Don't show the banner if we're operating in
5867 * non-verbose non-interactive mode. (It's probably
5868 * a script, which means nobody will read the
5869 * banner _anyway_, and moreover the printing of
5870 * the banner will screw up processing on the
5871 * output of (say) plink.)
5873 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
5874 ssh_pkt_getstring(pktin, &banner, &size);
5876 c_write_untrusted(ssh, banner, size);
5878 crWaitUntilV(pktin);
5880 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
5881 logevent("Access granted");
5882 s->we_are_in = TRUE;
5886 if (s->kbd_inter_running &&
5887 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
5889 * This is either a further set-of-prompts packet
5890 * in keyboard-interactive authentication, or it's
5891 * the same one and we came back here with `gotit'
5892 * set. In the former case, we must reset the
5893 * curr_prompt variable.
5897 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
5898 bombout(("Strange packet received during authentication: type %d",
5906 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5907 * we can look at the string in it and know what we can
5908 * helpfully try next.
5910 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
5913 ssh_pkt_getstring(pktin, &methods, &methlen);
5914 s->kbd_inter_running = FALSE;
5915 if (!ssh2_pkt_getbool(pktin)) {
5917 * We have received an unequivocal Access
5918 * Denied. This can translate to a variety of
5921 * - if we'd just tried "none" authentication,
5922 * it's not worth printing anything at all
5924 * - if we'd just tried a public key _offer_,
5925 * the message should be "Server refused our
5926 * key" (or no message at all if the key
5927 * came from Pageant)
5929 * - if we'd just tried anything else, the
5930 * message really should be "Access denied".
5932 * Additionally, if we'd just tried password
5933 * authentication, we should break out of this
5934 * whole loop so as to go back to the username
5935 * prompt (iff we're configured to allow
5936 * username change attempts).
5938 if (s->type == AUTH_TYPE_NONE) {
5940 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5941 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5942 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5943 c_write_str(ssh, "Server refused our key\r\n");
5944 logevent("Server refused public key");
5945 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5946 /* server declined keyboard-interactive; ignore */
5948 c_write_str(ssh, "Access denied\r\n");
5949 logevent("Access denied");
5950 if (s->type == AUTH_TYPE_PASSWORD &&
5951 ssh->cfg.change_username) {
5952 /* XXX perhaps we should allow
5953 * keyboard-interactive to do this too? */
5954 s->we_are_in = FALSE;
5959 c_write_str(ssh, "Further authentication required\r\n");
5960 logevent("Further authentication required");
5964 in_commasep_string("publickey", methods, methlen);
5966 in_commasep_string("password", methods, methlen);
5967 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5968 in_commasep_string("keyboard-interactive", methods, methlen);
5972 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5976 * Most password/passphrase prompts will be
5977 * non-echoing, so we set this to 0 by default.
5978 * Exception is that some keyboard-interactive prompts
5979 * can be echoing, in which case we'll set this to 1.
5983 if (!s->method && s->can_pubkey &&
5984 agent_exists() && !s->tried_agent) {
5986 * Attempt public-key authentication using Pageant.
5991 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5992 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5994 s->tried_agent = TRUE;
5996 logevent("Pageant is running. Requesting keys.");
5998 /* Request the keys held by the agent. */
5999 PUT_32BIT(s->request, 1);
6000 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6001 if (!agent_query(s->request, 5, &r, &s->responselen,
6002 ssh_agent_callback, ssh)) {
6006 bombout(("Unexpected data from server while"
6007 " waiting for agent response"));
6010 } while (pktin || inlen > 0);
6011 r = ssh->agent_response;
6012 s->responselen = ssh->agent_response_len;
6014 s->response = (unsigned char *) r;
6015 if (s->response && s->responselen >= 5 &&
6016 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6017 s->p = s->response + 5;
6018 s->nkeys = GET_32BIT(s->p);
6022 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6025 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6030 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6033 s->pklen = GET_32BIT(s->p);
6035 if (s->publickey_blob &&
6036 s->pklen == s->publickey_bloblen &&
6037 !memcmp(s->p, s->publickey_blob,
6038 s->publickey_bloblen)) {
6039 logevent("This key matches configured key file");
6040 s->tried_pubkey_config = 1;
6042 s->pkblob = (char *)s->p;
6044 s->alglen = GET_32BIT(s->pkblob);
6045 s->alg = s->pkblob + 4;
6046 s->commentlen = GET_32BIT(s->p);
6048 s->commentp = (char *)s->p;
6049 s->p += s->commentlen;
6050 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6051 ssh2_pkt_addstring(s->pktout, s->username);
6052 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6053 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6054 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6055 ssh2_pkt_addstring_start(s->pktout);
6056 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6057 ssh2_pkt_addstring_start(s->pktout);
6058 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6059 ssh2_pkt_send(ssh, s->pktout);
6061 crWaitUntilV(pktin);
6062 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6063 logevent("Key refused");
6067 if (flags & FLAG_VERBOSE) {
6068 c_write_str(ssh, "Authenticating with "
6070 c_write(ssh, s->commentp, s->commentlen);
6071 c_write_str(ssh, "\" from agent\r\n");
6075 * Server is willing to accept the key.
6076 * Construct a SIGN_REQUEST.
6078 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6079 ssh2_pkt_addstring(s->pktout, s->username);
6080 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6081 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6082 ssh2_pkt_addbool(s->pktout, TRUE);
6083 ssh2_pkt_addstring_start(s->pktout);
6084 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6085 ssh2_pkt_addstring_start(s->pktout);
6086 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6088 s->siglen = s->pktout->length - 5 + 4 + 20;
6089 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6091 s->len = 1; /* message type */
6092 s->len += 4 + s->pklen; /* key blob */
6093 s->len += 4 + s->siglen; /* data to sign */
6094 s->len += 4; /* flags */
6095 s->agentreq = snewn(4 + s->len, char);
6096 PUT_32BIT(s->agentreq, s->len);
6097 s->q = s->agentreq + 4;
6098 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6099 PUT_32BIT(s->q, s->pklen);
6101 memcpy(s->q, s->pkblob, s->pklen);
6103 PUT_32BIT(s->q, s->siglen);
6105 /* Now the data to be signed... */
6106 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6107 PUT_32BIT(s->q, 20);
6110 memcpy(s->q, ssh->v2_session_id, 20);
6112 memcpy(s->q, s->pktout->data + 5,
6113 s->pktout->length - 5);
6114 s->q += s->pktout->length - 5;
6115 /* And finally the (zero) flags word. */
6117 if (!agent_query(s->agentreq, s->len + 4,
6119 ssh_agent_callback, ssh)) {
6123 bombout(("Unexpected data from server"
6124 " while waiting for agent"
6128 } while (pktin || inlen > 0);
6129 vret = ssh->agent_response;
6130 s->retlen = ssh->agent_response_len;
6135 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6136 logevent("Sending Pageant's response");
6137 ssh2_add_sigblob(ssh, s->pktout,
6138 s->pkblob, s->pklen,
6140 GET_32BIT(s->ret + 5));
6141 ssh2_pkt_send(ssh, s->pktout);
6146 ("Pageant failed to answer challenge");
6157 if (!s->method && s->can_pubkey && s->publickey_blob
6158 && !s->tried_pubkey_config) {
6159 unsigned char *pub_blob;
6160 char *algorithm, *comment;
6163 s->tried_pubkey_config = TRUE;
6165 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6166 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6169 * Try the public key supplied in the configuration.
6171 * First, offer the public blob to see if the server is
6172 * willing to accept it.
6175 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6180 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6181 ssh2_pkt_addstring(s->pktout, s->username);
6182 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6183 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6184 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6185 ssh2_pkt_addstring(s->pktout, algorithm);
6186 ssh2_pkt_addstring_start(s->pktout);
6187 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6189 ssh2_pkt_send(ssh, s->pktout);
6190 logevent("Offered public key");
6192 crWaitUntilV(pktin);
6193 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6195 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6196 continue; /* key refused; give up on it */
6199 logevent("Offer of public key accepted");
6201 * Actually attempt a serious authentication using
6204 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6205 sprintf(s->pwprompt,
6206 "Passphrase for key \"%.100s\": ",
6212 if (flags & FLAG_VERBOSE) {
6213 c_write_str(ssh, "Authenticating with public key \"");
6214 c_write_str(ssh, comment);
6215 c_write_str(ssh, "\"\r\n");
6217 s->method = AUTH_PUBLICKEY_FILE;
6221 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6222 s->method = AUTH_KEYBOARD_INTERACTIVE;
6223 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6224 s->tried_keyb_inter = TRUE;
6226 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6227 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6229 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6230 ssh2_pkt_addstring(s->pktout, s->username);
6231 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6232 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6233 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6234 ssh2_pkt_addstring(s->pktout, "");
6235 ssh2_pkt_send(ssh, s->pktout);
6237 crWaitUntilV(pktin);
6238 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6239 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6241 logevent("Keyboard-interactive authentication refused");
6242 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6246 s->kbd_inter_running = TRUE;
6250 if (s->kbd_inter_running) {
6251 s->method = AUTH_KEYBOARD_INTERACTIVE;
6252 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6253 s->tried_keyb_inter = TRUE;
6255 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6256 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6258 if (s->curr_prompt == 0) {
6260 * We've got a fresh USERAUTH_INFO_REQUEST.
6261 * Display header data, and start going through
6264 char *name, *inst, *lang;
6265 int name_len, inst_len, lang_len;
6267 ssh_pkt_getstring(pktin, &name, &name_len);
6268 ssh_pkt_getstring(pktin, &inst, &inst_len);
6269 ssh_pkt_getstring(pktin, &lang, &lang_len);
6271 c_write_untrusted(ssh, name, name_len);
6272 c_write_str(ssh, "\r\n");
6275 c_write_untrusted(ssh, inst, inst_len);
6276 c_write_str(ssh, "\r\n");
6278 s->num_prompts = ssh_pkt_getuint32(pktin);
6282 * If there are prompts remaining in the packet,
6283 * display one and get a response.
6285 if (s->curr_prompt < s->num_prompts) {
6289 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6290 if (prompt_len > 0) {
6291 static const char trunc[] = "<prompt truncated>: ";
6292 static const int prlen = sizeof(s->pwprompt) -
6294 if (prompt_len > prlen) {
6295 memcpy(s->pwprompt, prompt, prlen);
6296 strcpy(s->pwprompt + prlen, trunc);
6298 memcpy(s->pwprompt, prompt, prompt_len);
6299 s->pwprompt[prompt_len] = '\0';
6303 "<server failed to send prompt>: ");
6305 s->echo = ssh2_pkt_getbool(pktin);
6311 if (!s->method && s->can_passwd) {
6312 s->method = AUTH_PASSWORD;
6313 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6314 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6315 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6322 if (!ssh_get_line(s->pwprompt, s->password,
6323 sizeof(s->password), TRUE)) {
6325 * get_line failed to get a password (for
6326 * example because one was supplied on the
6327 * command line which has already failed to
6330 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6331 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6332 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6334 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6335 ssh2_pkt_send_noqueue(ssh, s->pktout);
6336 logevent("Unable to authenticate");
6337 connection_fatal(ssh->frontend,
6338 "Unable to authenticate");
6339 ssh_closing((Plug)ssh, NULL, 0, 0);
6343 int ret; /* need not be saved across crReturn */
6344 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6347 setup_userpass_input(ssh, s->password,
6348 sizeof(s->password), s->echo);
6350 crWaitUntilV(!pktin);
6351 ret = process_userpass_input(ssh, in, inlen);
6355 c_write_str(ssh, "\r\n");
6359 if (s->method == AUTH_PUBLICKEY_FILE) {
6361 * We have our passphrase. Now try the actual authentication.
6363 struct ssh2_userkey *key;
6364 const char *error = NULL;
6366 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6368 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6369 if (key == SSH2_WRONG_PASSPHRASE) {
6370 c_write_str(ssh, "Wrong passphrase\r\n");
6371 s->tried_pubkey_config = FALSE;
6373 c_write_str(ssh, "Unable to load private key (");
6374 c_write_str(ssh, error);
6375 c_write_str(ssh, ")\r\n");
6376 s->tried_pubkey_config = TRUE;
6378 /* Send a spurious AUTH_NONE to return to the top. */
6379 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6380 ssh2_pkt_addstring(s->pktout, s->username);
6381 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6382 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6383 ssh2_pkt_send(ssh, s->pktout);
6384 s->type = AUTH_TYPE_NONE;
6386 unsigned char *pkblob, *sigblob, *sigdata;
6387 int pkblob_len, sigblob_len, sigdata_len;
6391 * We have loaded the private key and the server
6392 * has announced that it's willing to accept it.
6393 * Hallelujah. Generate a signature and send it.
6395 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6396 ssh2_pkt_addstring(s->pktout, s->username);
6397 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6398 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6399 ssh2_pkt_addbool(s->pktout, TRUE);
6400 ssh2_pkt_addstring(s->pktout, key->alg->name);
6401 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6402 ssh2_pkt_addstring_start(s->pktout);
6403 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6406 * The data to be signed is:
6410 * followed by everything so far placed in the
6413 sigdata_len = s->pktout->length - 5 + 4 + 20;
6414 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6416 sigdata = snewn(sigdata_len, unsigned char);
6418 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6419 PUT_32BIT(sigdata+p, 20);
6422 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6423 memcpy(sigdata+p, s->pktout->data + 5,
6424 s->pktout->length - 5);
6425 p += s->pktout->length - 5;
6426 assert(p == sigdata_len);
6427 sigblob = key->alg->sign(key->data, (char *)sigdata,
6428 sigdata_len, &sigblob_len);
6429 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6430 sigblob, sigblob_len);
6435 ssh2_pkt_send(ssh, s->pktout);
6436 s->type = AUTH_TYPE_PUBLICKEY;
6437 key->alg->freekey(key->data);
6439 } else if (s->method == AUTH_PASSWORD) {
6441 * We send the password packet lumped tightly together with
6442 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6443 * string long enough to make the total length of the two
6444 * packets constant. This should ensure that a passive
6445 * listener doing traffic analyis can't work out the length
6448 * For this to work, we need an assumption about the
6449 * maximum length of the password packet. I think 256 is
6450 * pretty conservative. Anyone using a password longer than
6451 * that probably doesn't have much to worry about from
6452 * people who find out how long their password is!
6454 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6455 ssh2_pkt_addstring(s->pktout, s->username);
6456 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6457 ssh2_pkt_addstring(s->pktout, "password");
6458 ssh2_pkt_addbool(s->pktout, FALSE);
6459 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6460 ssh2_pkt_addstring(s->pktout, s->password);
6461 memset(s->password, 0, sizeof(s->password));
6462 end_log_omission(ssh, s->pktout);
6463 ssh2_pkt_defer(ssh, s->pktout);
6465 * We'll include a string that's an exact multiple of the
6466 * cipher block size. If the cipher is NULL for some
6467 * reason, we don't do this trick at all because we gain
6470 if (ssh->cscipher) {
6473 stringlen = (256 - ssh->deferred_len);
6474 stringlen += ssh->cscipher->blksize - 1;
6475 stringlen -= (stringlen % ssh->cscipher->blksize);
6478 * Temporarily disable actual compression,
6479 * so we can guarantee to get this string
6480 * exactly the length we want it. The
6481 * compression-disabling routine should
6482 * return an integer indicating how many
6483 * bytes we should adjust our string length
6487 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6489 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6490 ssh2_pkt_addstring_start(s->pktout);
6491 for (i = 0; i < stringlen; i++) {
6492 char c = (char) random_byte();
6493 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6495 ssh2_pkt_defer(ssh, s->pktout);
6497 ssh_pkt_defersend(ssh);
6498 logevent("Sent password");
6499 s->type = AUTH_TYPE_PASSWORD;
6500 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6501 if (s->curr_prompt == 0) {
6502 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6503 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6505 if (s->need_pw) { /* only add pw if we just got one! */
6506 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6507 ssh2_pkt_addstring(s->pktout, s->password);
6508 memset(s->password, 0, sizeof(s->password));
6509 end_log_omission(ssh, s->pktout);
6512 if (s->curr_prompt >= s->num_prompts) {
6513 ssh2_pkt_send(ssh, s->pktout);
6516 * If there are prompts remaining, we set
6517 * `gotit' so that we won't attempt to get
6518 * another packet. Then we go back round the
6519 * loop and will end up retrieving another
6520 * prompt out of the existing packet. Funky or
6525 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6527 c_write_str(ssh, "No supported authentication methods"
6528 " left to try!\r\n");
6529 logevent("No supported authentications offered."
6531 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6532 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6533 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6534 " methods available");
6535 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6536 ssh2_pkt_send_noqueue(ssh, s->pktout);
6537 ssh_closing((Plug)ssh, NULL, 0, 0);
6541 } while (!s->we_are_in);
6544 * Now we're authenticated for the connection protocol. The
6545 * connection protocol will automatically have started at this
6546 * point; there's no need to send SERVICE_REQUEST.
6549 ssh->channels = newtree234(ssh_channelcmp);
6552 * Set up handlers for some connection protocol messages, so we
6553 * don't have to handle them repeatedly in this coroutine.
6555 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6556 ssh2_msg_channel_window_adjust;
6557 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6558 ssh2_msg_global_request;
6561 * Create the main session channel.
6563 if (!ssh->cfg.ssh_no_shell) {
6564 ssh->mainchan = snew(struct ssh_channel);
6565 ssh->mainchan->ssh = ssh;
6566 ssh->mainchan->localid = alloc_channel_id(ssh);
6567 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6568 ssh2_pkt_addstring(s->pktout, "session");
6569 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6570 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6571 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6572 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6573 ssh2_pkt_send(ssh, s->pktout);
6574 crWaitUntilV(pktin);
6575 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6576 bombout(("Server refused to open a session"));
6578 /* FIXME: error data comes back in FAILURE packet */
6580 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6581 bombout(("Server's channel confirmation cited wrong channel"));
6584 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6585 ssh->mainchan->type = CHAN_MAINSESSION;
6586 ssh->mainchan->closes = 0;
6587 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6588 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6589 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6590 add234(ssh->channels, ssh->mainchan);
6591 update_specials_menu(ssh->frontend);
6592 logevent("Opened channel for session");
6594 ssh->mainchan = NULL;
6597 * Now we have a channel, make dispatch table entries for
6598 * general channel-based messages.
6600 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6601 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6602 ssh2_msg_channel_data;
6603 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6604 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6605 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6606 ssh2_msg_channel_open_confirmation;
6607 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6608 ssh2_msg_channel_open_failure;
6609 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6610 ssh2_msg_channel_request;
6611 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6612 ssh2_msg_channel_open;
6615 * Potentially enable X11 forwarding.
6617 if (ssh->mainchan && ssh->cfg.x11_forward) {
6618 char proto[20], data[64];
6619 logevent("Requesting X11 forwarding");
6620 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6621 data, sizeof(data), ssh->cfg.x11_auth);
6622 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6623 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6624 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6625 ssh2_pkt_addstring(s->pktout, "x11-req");
6626 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6627 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6628 ssh2_pkt_addstring(s->pktout, proto);
6629 ssh2_pkt_addstring(s->pktout, data);
6630 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6631 ssh2_pkt_send(ssh, s->pktout);
6633 crWaitUntilV(pktin);
6635 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6636 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6637 bombout(("Unexpected response to X11 forwarding request:"
6638 " packet type %d", pktin->type));
6641 logevent("X11 forwarding refused");
6643 logevent("X11 forwarding enabled");
6644 ssh->X11_fwd_enabled = TRUE;
6649 * Enable port forwardings.
6651 ssh_setup_portfwd(ssh, &ssh->cfg);
6654 * Potentially enable agent forwarding.
6656 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6657 logevent("Requesting OpenSSH-style agent forwarding");
6658 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6659 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6660 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6661 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6662 ssh2_pkt_send(ssh, s->pktout);
6664 crWaitUntilV(pktin);
6666 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6667 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6668 bombout(("Unexpected response to agent forwarding request:"
6669 " packet type %d", pktin->type));
6672 logevent("Agent forwarding refused");
6674 logevent("Agent forwarding enabled");
6675 ssh->agentfwd_enabled = TRUE;
6680 * Now allocate a pty for the session.
6682 if (ssh->mainchan && !ssh->cfg.nopty) {
6683 /* Unpick the terminal-speed string. */
6684 /* XXX perhaps we should allow no speeds to be sent. */
6685 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6686 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6687 /* Build the pty request. */
6688 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6689 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6690 ssh2_pkt_addstring(s->pktout, "pty-req");
6691 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6692 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6693 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6694 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6695 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6696 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6697 ssh2_pkt_addstring_start(s->pktout);
6698 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6699 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6700 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6701 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6702 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6703 ssh2_pkt_send(ssh, s->pktout);
6704 ssh->state = SSH_STATE_INTERMED;
6706 crWaitUntilV(pktin);
6708 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6709 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6710 bombout(("Unexpected response to pty request:"
6711 " packet type %d", pktin->type));
6714 c_write_str(ssh, "Server refused to allocate pty\r\n");
6715 ssh->editing = ssh->echoing = 1;
6717 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6718 ssh->ospeed, ssh->ispeed);
6721 ssh->editing = ssh->echoing = 1;
6725 * Send environment variables.
6727 * Simplest thing here is to send all the requests at once, and
6728 * then wait for a whole bunch of successes or failures.
6730 if (ssh->mainchan && *ssh->cfg.environmt) {
6731 char *e = ssh->cfg.environmt;
6732 char *var, *varend, *val;
6738 while (*e && *e != '\t') e++;
6740 if (*e == '\t') e++;
6745 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6746 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6747 ssh2_pkt_addstring(s->pktout, "env");
6748 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6749 ssh2_pkt_addstring_start(s->pktout);
6750 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6751 ssh2_pkt_addstring(s->pktout, val);
6752 ssh2_pkt_send(ssh, s->pktout);
6757 logeventf(ssh, "Sent %d environment variables", s->num_env);
6760 s->env_left = s->num_env;
6762 while (s->env_left > 0) {
6763 crWaitUntilV(pktin);
6765 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6766 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6767 bombout(("Unexpected response to environment request:"
6768 " packet type %d", pktin->type));
6778 if (s->env_ok == s->num_env) {
6779 logevent("All environment variables successfully set");
6780 } else if (s->env_ok == 0) {
6781 logevent("All environment variables refused");
6782 c_write_str(ssh, "Server refused to set environment variables\r\n");
6784 logeventf(ssh, "%d environment variables refused",
6785 s->num_env - s->env_ok);
6786 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6791 * Start a shell or a remote command. We may have to attempt
6792 * this twice if the config data has provided a second choice
6795 if (ssh->mainchan) while (1) {
6799 if (ssh->fallback_cmd) {
6800 subsys = ssh->cfg.ssh_subsys2;
6801 cmd = ssh->cfg.remote_cmd_ptr2;
6803 subsys = ssh->cfg.ssh_subsys;
6804 cmd = ssh->cfg.remote_cmd_ptr;
6807 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6808 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6810 ssh2_pkt_addstring(s->pktout, "subsystem");
6811 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6812 ssh2_pkt_addstring(s->pktout, cmd);
6814 ssh2_pkt_addstring(s->pktout, "exec");
6815 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6816 ssh2_pkt_addstring(s->pktout, cmd);
6818 ssh2_pkt_addstring(s->pktout, "shell");
6819 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6821 ssh2_pkt_send(ssh, s->pktout);
6823 crWaitUntilV(pktin);
6825 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6826 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6827 bombout(("Unexpected response to shell/command request:"
6828 " packet type %d", pktin->type));
6832 * We failed to start the command. If this is the
6833 * fallback command, we really are finished; if it's
6834 * not, and if the fallback command exists, try falling
6835 * back to it before complaining.
6837 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6838 logevent("Primary command failed; attempting fallback");
6839 ssh->fallback_cmd = TRUE;
6842 bombout(("Server refused to start a shell/command"));
6845 logevent("Started a shell/command");
6850 ssh->state = SSH_STATE_SESSION;
6851 if (ssh->size_needed)
6852 ssh_size(ssh, ssh->term_width, ssh->term_height);
6853 if (ssh->eof_needed)
6854 ssh_special(ssh, TS_EOF);
6860 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6865 s->try_send = FALSE;
6869 * _All_ the connection-layer packets we expect to
6870 * receive are now handled by the dispatch table.
6871 * Anything that reaches here must be bogus.
6874 bombout(("Strange packet received: type %d", pktin->type));
6876 } else if (ssh->mainchan) {
6878 * We have spare data. Add it to the channel buffer.
6880 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6885 struct ssh_channel *c;
6887 * Try to send data on all channels if we can.
6889 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6892 continue; /* don't send on closing channels */
6893 bufsize = ssh2_try_send(c);
6896 case CHAN_MAINSESSION:
6897 /* stdin need not receive an unthrottle
6898 * notification since it will be polled */
6901 x11_unthrottle(c->u.x11.s);
6904 /* agent sockets are request/response and need no
6905 * buffer management */
6908 pfd_unthrottle(c->u.pfd.s);
6920 * Handlers for SSH2 messages that might arrive at any moment.
6922 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6924 /* log reason code in disconnect message */
6926 int nowlen, reason, msglen;
6928 reason = ssh_pkt_getuint32(pktin);
6929 ssh_pkt_getstring(pktin, &msg, &msglen);
6931 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6932 buf = dupprintf("Received disconnect message (%s)",
6933 ssh2_disconnect_reasons[reason]);
6935 buf = dupprintf("Received disconnect message (unknown"
6936 " type %d)", reason);
6940 buf = dupprintf("Disconnection message text: %n%.*s",
6941 &nowlen, msglen, msg);
6943 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6945 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6946 ssh2_disconnect_reasons[reason] : "unknown",
6951 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6953 /* log the debug message */
6958 /* XXX maybe we should actually take notice of this */
6959 always_display = ssh2_pkt_getbool(pktin);
6960 ssh_pkt_getstring(pktin, &msg, &msglen);
6962 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6967 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6969 struct Packet *pktout;
6970 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6971 ssh2_pkt_adduint32(pktout, pktin->sequence);
6973 * UNIMPLEMENTED messages MUST appear in the same order as the
6974 * messages they respond to. Hence, never queue them.
6976 ssh2_pkt_send_noqueue(ssh, pktout);
6980 * Handle the top-level SSH2 protocol.
6982 static void ssh2_protocol_setup(Ssh ssh)
6987 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6989 for (i = 0; i < 256; i++)
6990 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6993 * Any message we actually understand, we set to NULL so that
6994 * the coroutines will get it.
6996 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6997 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6998 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6999 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7000 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7001 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7002 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7003 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7004 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7005 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7006 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7007 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7008 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7009 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7010 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7011 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7012 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7013 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7014 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7015 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7016 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7017 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7025 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7026 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7027 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7028 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7031 * These special message types we install handlers for.
7033 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7034 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7035 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7038 static void ssh2_timer(void *ctx, long now)
7042 if (!ssh->kex_in_progress &&
7043 now - ssh->next_rekey >= 0) {
7044 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7049 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7050 struct Packet *pktin)
7052 if (ssh->state == SSH_STATE_CLOSED)
7056 ssh->incoming_data_size += pktin->encrypted_len;
7057 if (!ssh->kex_in_progress &&
7058 ssh->max_data_size != 0 &&
7059 ssh->incoming_data_size > ssh->max_data_size)
7060 do_ssh2_transport(ssh, "Initiating key re-exchange "
7061 "(too much data received)", -1, NULL);
7064 if (pktin && ssh->packet_dispatch[pktin->type]) {
7065 ssh->packet_dispatch[pktin->type](ssh, pktin);
7069 if (!ssh->protocol_initial_phase_done ||
7070 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7071 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7072 !ssh->protocol_initial_phase_done) {
7073 ssh->protocol_initial_phase_done = TRUE;
7075 * Allow authconn to initialise itself.
7077 do_ssh2_authconn(ssh, NULL, 0, NULL);
7080 do_ssh2_authconn(ssh, in, inlen, pktin);
7085 * Called to set up the connection.
7087 * Returns an error message, or NULL on success.
7089 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7091 char *host, int port, char **realhost, int nodelay,
7097 ssh = snew(struct ssh_tag);
7098 ssh->cfg = *cfg; /* STRUCTURE COPY */
7099 ssh->version = 0; /* when not ready yet */
7102 ssh->v1_cipher_ctx = NULL;
7103 ssh->crcda_ctx = NULL;
7104 ssh->cscipher = NULL;
7105 ssh->cs_cipher_ctx = NULL;
7106 ssh->sccipher = NULL;
7107 ssh->sc_cipher_ctx = NULL;
7109 ssh->cs_mac_ctx = NULL;
7111 ssh->sc_mac_ctx = NULL;
7113 ssh->cs_comp_ctx = NULL;
7115 ssh->sc_comp_ctx = NULL;
7117 ssh->kex_ctx = NULL;
7118 ssh->hostkey = NULL;
7120 ssh->state = SSH_STATE_PREPACKET;
7121 ssh->size_needed = FALSE;
7122 ssh->eof_needed = FALSE;
7125 ssh->deferred_send_data = NULL;
7126 ssh->deferred_len = 0;
7127 ssh->deferred_size = 0;
7128 ssh->fallback_cmd = 0;
7130 ssh->x11auth = NULL;
7131 ssh->v1_compressing = FALSE;
7132 ssh->v2_outgoing_sequence = 0;
7133 ssh->ssh1_rdpkt_crstate = 0;
7134 ssh->ssh2_rdpkt_crstate = 0;
7135 ssh->do_ssh_init_crstate = 0;
7136 ssh->ssh_gotdata_crstate = 0;
7137 ssh->do_ssh1_connection_crstate = 0;
7138 ssh->do_ssh1_login_crstate = 0;
7139 ssh->do_ssh2_transport_crstate = 0;
7140 ssh->do_ssh2_authconn_crstate = 0;
7141 ssh->do_ssh_init_state = NULL;
7142 ssh->do_ssh1_login_state = NULL;
7143 ssh->do_ssh2_transport_state = NULL;
7144 ssh->do_ssh2_authconn_state = NULL;
7145 ssh->mainchan = NULL;
7146 ssh->throttled_all = 0;
7147 ssh->v1_stdout_throttling = 0;
7149 ssh->queuelen = ssh->queuesize = 0;
7150 ssh->queueing = FALSE;
7151 ssh->qhead = ssh->qtail = NULL;
7153 *backend_handle = ssh;
7156 if (crypto_startup() == 0)
7157 return "Microsoft high encryption pack not installed!";
7160 ssh->frontend = frontend_handle;
7161 ssh->term_width = ssh->cfg.width;
7162 ssh->term_height = ssh->cfg.height;
7164 ssh->channels = NULL;
7165 ssh->rportfwds = NULL;
7170 ssh->v1_throttle_count = 0;
7171 ssh->overall_bufsize = 0;
7172 ssh->fallback_cmd = 0;
7174 ssh->protocol = NULL;
7176 ssh->protocol_initial_phase_done = FALSE;
7180 ssh->incoming_data_size = ssh->outgoing_data_size =
7181 ssh->deferred_data_size = 0L;
7182 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7183 ssh->kex_in_progress = FALSE;
7185 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7194 static void ssh_free(void *handle)
7196 Ssh ssh = (Ssh) handle;
7197 struct ssh_channel *c;
7198 struct ssh_rportfwd *pf;
7200 if (ssh->v1_cipher_ctx)
7201 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7202 if (ssh->cs_cipher_ctx)
7203 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7204 if (ssh->sc_cipher_ctx)
7205 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7206 if (ssh->cs_mac_ctx)
7207 ssh->csmac->free_context(ssh->cs_mac_ctx);
7208 if (ssh->sc_mac_ctx)
7209 ssh->scmac->free_context(ssh->sc_mac_ctx);
7210 if (ssh->cs_comp_ctx) {
7212 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7214 zlib_compress_cleanup(ssh->cs_comp_ctx);
7216 if (ssh->sc_comp_ctx) {
7218 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7220 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7223 dh_cleanup(ssh->kex_ctx);
7224 sfree(ssh->savedhost);
7226 while (ssh->queuelen-- > 0)
7227 ssh_free_packet(ssh->queue[ssh->queuelen]);
7230 while (ssh->qhead) {
7231 struct queued_handler *qh = ssh->qhead;
7232 ssh->qhead = qh->next;
7235 ssh->qhead = ssh->qtail = NULL;
7237 if (ssh->channels) {
7238 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7241 if (c->u.x11.s != NULL)
7242 x11_close(c->u.x11.s);
7245 if (c->u.pfd.s != NULL)
7246 pfd_close(c->u.pfd.s);
7251 freetree234(ssh->channels);
7252 ssh->channels = NULL;
7255 if (ssh->rportfwds) {
7256 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7258 freetree234(ssh->rportfwds);
7259 ssh->rportfwds = NULL;
7261 sfree(ssh->deferred_send_data);
7263 x11_free_auth(ssh->x11auth);
7264 sfree(ssh->do_ssh_init_state);
7265 sfree(ssh->do_ssh1_login_state);
7266 sfree(ssh->do_ssh2_transport_state);
7267 sfree(ssh->do_ssh2_authconn_state);
7268 if (ssh->crcda_ctx) {
7269 crcda_free_context(ssh->crcda_ctx);
7270 ssh->crcda_ctx = NULL;
7274 expire_timer_context(ssh);
7276 pinger_free(ssh->pinger);
7283 * Reconfigure the SSH backend.
7285 * Currently, this function does nothing very useful. In future,
7286 * however, we could do some handy things with it. For example, we
7287 * could make the port forwarding configurer active in the Change
7288 * Settings box, and this routine could close down existing
7289 * forwardings and open up new ones in response to changes.
7291 static void ssh_reconfig(void *handle, Config *cfg)
7293 Ssh ssh = (Ssh) handle;
7294 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7295 ssh->cfg = *cfg; /* STRUCTURE COPY */
7299 * Called to send data down the Telnet connection.
7301 static int ssh_send(void *handle, char *buf, int len)
7303 Ssh ssh = (Ssh) handle;
7305 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7308 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7310 return ssh_sendbuffer(ssh);
7314 * Called to query the current amount of buffered stdin data.
7316 static int ssh_sendbuffer(void *handle)
7318 Ssh ssh = (Ssh) handle;
7321 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7325 * If the SSH socket itself has backed up, add the total backup
7326 * size on that to any individual buffer on the stdin channel.
7329 if (ssh->throttled_all)
7330 override_value = ssh->overall_bufsize;
7332 if (ssh->version == 1) {
7333 return override_value;
7334 } else if (ssh->version == 2) {
7335 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7336 return override_value;
7338 return (override_value +
7339 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7346 * Called to set the size of the window from SSH's POV.
7348 static void ssh_size(void *handle, int width, int height)
7350 Ssh ssh = (Ssh) handle;
7351 struct Packet *pktout;
7353 ssh->term_width = width;
7354 ssh->term_height = height;
7356 switch (ssh->state) {
7357 case SSH_STATE_BEFORE_SIZE:
7358 case SSH_STATE_PREPACKET:
7359 case SSH_STATE_CLOSED:
7360 break; /* do nothing */
7361 case SSH_STATE_INTERMED:
7362 ssh->size_needed = TRUE; /* buffer for later */
7364 case SSH_STATE_SESSION:
7365 if (!ssh->cfg.nopty) {
7366 if (ssh->version == 1) {
7367 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7368 PKT_INT, ssh->term_height,
7369 PKT_INT, ssh->term_width,
7370 PKT_INT, 0, PKT_INT, 0, PKT_END);
7371 } else if (ssh->mainchan) {
7372 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7373 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7374 ssh2_pkt_addstring(pktout, "window-change");
7375 ssh2_pkt_addbool(pktout, 0);
7376 ssh2_pkt_adduint32(pktout, ssh->term_width);
7377 ssh2_pkt_adduint32(pktout, ssh->term_height);
7378 ssh2_pkt_adduint32(pktout, 0);
7379 ssh2_pkt_adduint32(pktout, 0);
7380 ssh2_pkt_send(ssh, pktout);
7388 * Return a list of the special codes that make sense in this
7391 static const struct telnet_special *ssh_get_specials(void *handle)
7393 static const struct telnet_special ssh1_ignore_special[] = {
7394 {"IGNORE message", TS_NOP}
7396 static const struct telnet_special ssh2_transport_specials[] = {
7397 {"IGNORE message", TS_NOP},
7398 {"Repeat key exchange", TS_REKEY},
7400 static const struct telnet_special ssh2_session_specials[] = {
7403 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7404 * They include all the ISO C signals, but are a subset of the POSIX
7405 * required signals. */
7406 {"SIGINT (Interrupt)", TS_SIGINT},
7407 {"SIGTERM (Terminate)", TS_SIGTERM},
7408 {"SIGKILL (Kill)", TS_SIGKILL},
7409 {"SIGQUIT (Quit)", TS_SIGQUIT},
7410 {"SIGHUP (Hangup)", TS_SIGHUP},
7411 {"More signals", TS_SUBMENU},
7412 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7413 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7414 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7415 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7418 static const struct telnet_special specials_end[] = {
7421 /* XXX review this length for any changes: */
7422 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7423 lenof(ssh2_session_specials) +
7424 lenof(specials_end)];
7425 Ssh ssh = (Ssh) handle;
7427 #define ADD_SPECIALS(name) \
7429 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7430 memcpy(&ssh_specials[i], name, sizeof name); \
7434 if (ssh->version == 1) {
7435 /* Don't bother offering IGNORE if we've decided the remote
7436 * won't cope with it, since we wouldn't bother sending it if
7438 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7439 ADD_SPECIALS(ssh1_ignore_special);
7440 } else if (ssh->version == 2) {
7441 ADD_SPECIALS(ssh2_transport_specials);
7443 ADD_SPECIALS(ssh2_session_specials);
7444 } /* else we're not ready yet */
7447 ADD_SPECIALS(specials_end);
7448 return ssh_specials;
7456 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7457 * can send an EOF and collect resulting output (e.g. `plink
7460 static void ssh_special(void *handle, Telnet_Special code)
7462 Ssh ssh = (Ssh) handle;
7463 struct Packet *pktout;
7465 if (code == TS_EOF) {
7466 if (ssh->state != SSH_STATE_SESSION) {
7468 * Buffer the EOF in case we are pre-SESSION, so we can
7469 * send it as soon as we reach SESSION.
7472 ssh->eof_needed = TRUE;
7475 if (ssh->version == 1) {
7476 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7477 } else if (ssh->mainchan) {
7478 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7479 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7480 ssh2_pkt_send(ssh, pktout);
7482 logevent("Sent EOF message");
7483 } else if (code == TS_PING || code == TS_NOP) {
7484 if (ssh->state == SSH_STATE_CLOSED
7485 || ssh->state == SSH_STATE_PREPACKET) return;
7486 if (ssh->version == 1) {
7487 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7488 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7490 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7491 ssh2_pkt_addstring_start(pktout);
7492 ssh2_pkt_send_noqueue(ssh, pktout);
7494 } else if (code == TS_REKEY) {
7495 if (!ssh->kex_in_progress && ssh->version == 2) {
7496 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7497 " user request", -1, NULL);
7499 } else if (code == TS_BRK) {
7500 if (ssh->state == SSH_STATE_CLOSED
7501 || ssh->state == SSH_STATE_PREPACKET) return;
7502 if (ssh->version == 1) {
7503 logevent("Unable to send BREAK signal in SSH1");
7504 } else if (ssh->mainchan) {
7505 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7506 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7507 ssh2_pkt_addstring(pktout, "break");
7508 ssh2_pkt_addbool(pktout, 0);
7509 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7510 ssh2_pkt_send(ssh, pktout);
7513 /* Is is a POSIX signal? */
7514 char *signame = NULL;
7515 if (code == TS_SIGABRT) signame = "ABRT";
7516 if (code == TS_SIGALRM) signame = "ALRM";
7517 if (code == TS_SIGFPE) signame = "FPE";
7518 if (code == TS_SIGHUP) signame = "HUP";
7519 if (code == TS_SIGILL) signame = "ILL";
7520 if (code == TS_SIGINT) signame = "INT";
7521 if (code == TS_SIGKILL) signame = "KILL";
7522 if (code == TS_SIGPIPE) signame = "PIPE";
7523 if (code == TS_SIGQUIT) signame = "QUIT";
7524 if (code == TS_SIGSEGV) signame = "SEGV";
7525 if (code == TS_SIGTERM) signame = "TERM";
7526 if (code == TS_SIGUSR1) signame = "USR1";
7527 if (code == TS_SIGUSR2) signame = "USR2";
7528 /* The SSH-2 protocol does in principle support arbitrary named
7529 * signals, including signame@domain, but we don't support those. */
7531 /* It's a signal. */
7532 if (ssh->version == 2 && ssh->mainchan) {
7533 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7534 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7535 ssh2_pkt_addstring(pktout, "signal");
7536 ssh2_pkt_addbool(pktout, 0);
7537 ssh2_pkt_addstring(pktout, signame);
7538 ssh2_pkt_send(ssh, pktout);
7539 logeventf(ssh, "Sent signal SIG%s", signame);
7542 /* Never heard of it. Do nothing */
7547 void *new_sock_channel(void *handle, Socket s)
7549 Ssh ssh = (Ssh) handle;
7550 struct ssh_channel *c;
7551 c = snew(struct ssh_channel);
7555 c->remoteid = -1; /* to be set when open confirmed */
7556 c->localid = alloc_channel_id(ssh);
7558 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7560 bufchain_init(&c->v.v2.outbuffer);
7561 add234(ssh->channels, c);
7567 * This is called when stdout/stderr (the entity to which
7568 * from_backend sends data) manages to clear some backlog.
7570 static void ssh_unthrottle(void *handle, int bufsize)
7572 Ssh ssh = (Ssh) handle;
7573 if (ssh->version == 1) {
7574 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7575 ssh->v1_stdout_throttling = 0;
7576 ssh1_throttle(ssh, -1);
7579 if (ssh->mainchan && ssh->mainchan->closes == 0)
7580 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7584 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7586 struct ssh_channel *c = (struct ssh_channel *)channel;
7588 struct Packet *pktout;
7590 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7592 if (ssh->version == 1) {
7593 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7594 PKT_INT, c->localid,
7597 //PKT_STR, <org:orgport>,
7600 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7601 ssh2_pkt_addstring(pktout, "direct-tcpip");
7602 ssh2_pkt_adduint32(pktout, c->localid);
7603 c->v.v2.locwindow = OUR_V2_WINSIZE;
7604 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7605 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7606 ssh2_pkt_addstring(pktout, hostname);
7607 ssh2_pkt_adduint32(pktout, port);
7609 * We make up values for the originator data; partly it's
7610 * too much hassle to keep track, and partly I'm not
7611 * convinced the server should be told details like that
7612 * about my local network configuration.
7614 ssh2_pkt_addstring(pktout, "client-side-connection");
7615 ssh2_pkt_adduint32(pktout, 0);
7616 ssh2_pkt_send(ssh, pktout);
7620 static Socket ssh_socket(void *handle)
7622 Ssh ssh = (Ssh) handle;
7626 static int ssh_sendok(void *handle)
7628 Ssh ssh = (Ssh) handle;
7629 return ssh->send_ok;
7632 static int ssh_ldisc(void *handle, int option)
7634 Ssh ssh = (Ssh) handle;
7635 if (option == LD_ECHO)
7636 return ssh->echoing;
7637 if (option == LD_EDIT)
7638 return ssh->editing;
7642 static void ssh_provide_ldisc(void *handle, void *ldisc)
7644 Ssh ssh = (Ssh) handle;
7648 static void ssh_provide_logctx(void *handle, void *logctx)
7650 Ssh ssh = (Ssh) handle;
7651 ssh->logctx = logctx;
7654 static int ssh_return_exitcode(void *handle)
7656 Ssh ssh = (Ssh) handle;
7660 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7664 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7665 * that fails. This variable is the means by which scp.c can reach
7666 * into the SSH code and find out which one it got.
7668 extern int ssh_fallback_cmd(void *handle)
7670 Ssh ssh = (Ssh) handle;
7671 return ssh->fallback_cmd;
7674 Backend ssh_backend = {
7684 ssh_return_exitcode,