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_DHGROUP1 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 #define BUG_SSH2_DH_GEX 64
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_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
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_kex *kex_algs[] = {
364 &ssh_diffiehellman_gex,
368 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
370 static void *nullmac_make_context(void)
374 static void nullmac_free_context(void *handle)
377 static void nullmac_key(void *handle, unsigned char *key)
380 static void nullmac_generate(void *handle, unsigned char *blk, int len,
384 static int nullmac_verify(void *handle, unsigned char *blk, int len,
389 const static struct ssh_mac ssh_mac_none = {
390 nullmac_make_context, nullmac_free_context, nullmac_key,
391 nullmac_generate, nullmac_verify, "none", 0
393 const static struct ssh_mac *macs[] = {
394 &ssh_sha1, &ssh_md5, &ssh_mac_none
396 const static struct ssh_mac *buggymacs[] = {
397 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
400 static void *ssh_comp_none_init(void)
404 static void ssh_comp_none_cleanup(void *handle)
407 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
408 unsigned char **outblock, int *outlen)
412 static int ssh_comp_none_disable(void *handle)
416 const static struct ssh_compress ssh_comp_none = {
418 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
419 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
420 ssh_comp_none_disable, NULL
422 extern const struct ssh_compress ssh_zlib;
423 const static struct ssh_compress *compressions[] = {
424 &ssh_zlib, &ssh_comp_none
427 enum { /* channel types */
432 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
436 * 2-3-4 tree storing channels.
439 Ssh ssh; /* pointer back to main context */
440 unsigned remoteid, localid;
443 * In SSH1, this value contains four bits:
445 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
446 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
447 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
448 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
450 * A channel is completely finished with when all four bits are set.
454 struct ssh1_data_channel {
457 struct ssh2_data_channel {
459 unsigned remwindow, remmaxpkt;
464 struct ssh_agent_channel {
465 unsigned char *message;
466 unsigned char msglen[4];
467 unsigned lensofar, totallen;
469 struct ssh_x11_channel {
472 struct ssh_pfd_channel {
479 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
480 * 2 use this structure in different ways, reflecting SSH 2's
481 * altogether saner approach to port forwarding.
483 * In SSH 1, you arrange a remote forwarding by sending the server
484 * the remote port number, and the local destination host:port.
485 * When a connection comes in, the server sends you back that
486 * host:port pair, and you connect to it. This is a ready-made
487 * security hole if you're not on the ball: a malicious server
488 * could send you back _any_ host:port pair, so if you trustingly
489 * connect to the address it gives you then you've just opened the
490 * entire inside of your corporate network just by connecting
491 * through it to a dodgy SSH server. Hence, we must store a list of
492 * host:port pairs we _are_ trying to forward to, and reject a
493 * connection request from the server if it's not in the list.
495 * In SSH 2, each side of the connection minds its own business and
496 * doesn't send unnecessary information to the other. You arrange a
497 * remote forwarding by sending the server just the remote port
498 * number. When a connection comes in, the server tells you which
499 * of its ports was connected to; and _you_ have to remember what
500 * local host:port pair went with that port number.
502 * Hence: in SSH 1 this structure stores host:port pairs we intend
503 * to allow connections to, and is indexed by those host:port
504 * pairs. In SSH 2 it stores a mapping from source port to
505 * destination host:port pair, and is indexed by source port.
507 struct ssh_rportfwd {
508 unsigned sport, dport;
515 unsigned long sequence;
520 long encrypted_len; /* for SSH2 total-size counting */
523 * State associated with packet logging
527 struct logblank_t *blanks;
530 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
531 struct Packet *pktin);
532 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
533 struct Packet *pktin);
534 static void ssh1_protocol_setup(Ssh ssh);
535 static void ssh2_protocol_setup(Ssh ssh);
536 static void ssh_size(void *handle, int width, int height);
537 static void ssh_special(void *handle, Telnet_Special);
538 static int ssh2_try_send(struct ssh_channel *c);
539 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
540 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
541 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
542 static int ssh_sendbuffer(void *handle);
543 static void ssh_do_close(Ssh ssh);
544 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
545 static int ssh2_pkt_getbool(struct Packet *pkt);
546 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
547 static void ssh2_timer(void *ctx, long now);
548 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
549 struct Packet *pktin);
551 struct rdpkt1_state_tag {
552 long len, pad, biglen, to_read;
553 unsigned long realcrc, gotcrc;
557 struct Packet *pktin;
560 struct rdpkt2_state_tag {
561 long len, pad, payload, packetlen, maclen;
564 unsigned long incoming_sequence;
565 struct Packet *pktin;
568 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
571 const struct plug_function_table *fn;
572 /* the above field _must_ be first in the structure */
574 SHA_State exhash, exhashbase;
581 unsigned char session_key[32];
583 int v1_remote_protoflags;
584 int v1_local_protoflags;
585 int agentfwd_enabled;
588 const struct ssh_cipher *cipher;
591 const struct ssh2_cipher *cscipher, *sccipher;
592 void *cs_cipher_ctx, *sc_cipher_ctx;
593 const struct ssh_mac *csmac, *scmac;
594 void *cs_mac_ctx, *sc_mac_ctx;
595 const struct ssh_compress *cscomp, *sccomp;
596 void *cs_comp_ctx, *sc_comp_ctx;
597 const struct ssh_kex *kex;
598 const struct ssh_signkey *hostkey;
599 unsigned char v2_session_id[20];
605 int echoing, editing;
609 int ospeed, ispeed; /* temporaries */
610 int term_width, term_height;
612 tree234 *channels; /* indexed by local id */
613 struct ssh_channel *mainchan; /* primary session channel */
620 SSH_STATE_BEFORE_SIZE,
626 int size_needed, eof_needed;
628 struct Packet **queue;
629 int queuelen, queuesize;
631 unsigned char *deferred_send_data;
632 int deferred_len, deferred_size;
635 * Gross hack: pscp will try to start SFTP but fall back to
636 * scp1 if that fails. This variable is the means by which
637 * scp.c can reach into the SSH code and find out which one it
643 * Used for username and password input.
645 char *userpass_input_buffer;
646 int userpass_input_buflen;
647 int userpass_input_bufpos;
648 int userpass_input_echo;
650 char *portfwd_strptr;
656 int v1_throttle_count;
659 int v1_stdout_throttling;
660 int v2_outgoing_sequence;
662 int ssh1_rdpkt_crstate;
663 int ssh2_rdpkt_crstate;
664 int do_ssh_init_crstate;
665 int ssh_gotdata_crstate;
666 int do_ssh1_login_crstate;
667 int do_ssh1_connection_crstate;
668 int do_ssh2_transport_crstate;
669 int do_ssh2_authconn_crstate;
671 void *do_ssh_init_state;
672 void *do_ssh1_login_state;
673 void *do_ssh2_transport_state;
674 void *do_ssh2_authconn_state;
676 struct rdpkt1_state_tag rdpkt1_state;
677 struct rdpkt2_state_tag rdpkt2_state;
679 /* ssh1 and ssh2 use this for different things, but both use it */
680 int protocol_initial_phase_done;
682 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
684 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
687 * We maintain a full _copy_ of a Config structure here, not
688 * merely a pointer to it. That way, when we're passed a new
689 * one for reconfiguration, we can check the differences and
690 * potentially reconfigure port forwardings etc in mid-session.
695 * Used to transfer data back from async agent callbacks.
697 void *agent_response;
698 int agent_response_len;
701 * Dispatch table for packet types that we may have to deal
704 handler_fn_t packet_dispatch[256];
707 * This module deals with sending keepalives.
712 * Track incoming and outgoing data sizes and time, for
715 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
720 #define MAX_DATA_BEFORE_REKEY (0x40000000UL)
721 #define REKEY_TIMEOUT (3600 * TICKSPERSEC)
723 #define logevent(s) logevent(ssh->frontend, s)
725 /* logevent, only printf-formatted. */
726 static void logeventf(Ssh ssh, const char *fmt, ...)
732 buf = dupvprintf(fmt, ap);
738 #define bombout(msg) \
740 char *text = dupprintf msg; \
743 connection_fatal(ssh->frontend, "%s", text); \
747 /* Functions to leave bits out of the SSH packet log file. */
749 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
751 if (ssh->cfg.logomitpass)
752 pkt->logmode = blanktype;
755 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
757 if (ssh->cfg.logomitdata)
758 pkt->logmode = blanktype;
761 static void end_log_omission(Ssh ssh, struct Packet *pkt)
763 pkt->logmode = PKTLOG_EMIT;
766 static int ssh_channelcmp(void *av, void *bv)
768 struct ssh_channel *a = (struct ssh_channel *) av;
769 struct ssh_channel *b = (struct ssh_channel *) bv;
770 if (a->localid < b->localid)
772 if (a->localid > b->localid)
776 static int ssh_channelfind(void *av, void *bv)
778 unsigned *a = (unsigned *) av;
779 struct ssh_channel *b = (struct ssh_channel *) bv;
787 static int ssh_rportcmp_ssh1(void *av, void *bv)
789 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
790 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
792 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
793 return i < 0 ? -1 : +1;
794 if (a->dport > b->dport)
796 if (a->dport < b->dport)
801 static int ssh_rportcmp_ssh2(void *av, void *bv)
803 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
804 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
806 if (a->sport > b->sport)
808 if (a->sport < b->sport)
813 static int alloc_channel_id(Ssh ssh)
815 const unsigned CHANNEL_NUMBER_OFFSET = 256;
816 unsigned low, high, mid;
818 struct ssh_channel *c;
821 * First-fit allocation of channel numbers: always pick the
822 * lowest unused one. To do this, binary-search using the
823 * counted B-tree to find the largest channel ID which is in a
824 * contiguous sequence from the beginning. (Precisely
825 * everything in that sequence must have ID equal to its tree
826 * index plus CHANNEL_NUMBER_OFFSET.)
828 tsize = count234(ssh->channels);
832 while (high - low > 1) {
833 mid = (high + low) / 2;
834 c = index234(ssh->channels, mid);
835 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
836 low = mid; /* this one is fine */
838 high = mid; /* this one is past it */
841 * Now low points to either -1, or the tree index of the
842 * largest ID in the initial sequence.
845 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
846 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
848 return low + 1 + CHANNEL_NUMBER_OFFSET;
851 static void c_write(Ssh ssh, const char *buf, int len)
853 if ((flags & FLAG_STDERR)) {
855 for (i = 0; i < len; i++)
857 fputc(buf[i], stderr);
860 from_backend(ssh->frontend, 1, buf, len);
863 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
866 for (i = 0; i < len; i++) {
868 c_write(ssh, "\r\n", 2);
869 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
870 c_write(ssh, buf + i, 1);
874 static void c_write_str(Ssh ssh, const char *buf)
876 c_write(ssh, buf, strlen(buf));
879 static void ssh_free_packet(struct Packet *pkt)
884 static struct Packet *ssh_new_packet(void)
886 struct Packet *pkt = snew(struct Packet);
890 pkt->logmode = PKTLOG_EMIT;
898 * Collect incoming data in the incoming packet buffer.
899 * Decipher and verify the packet when it is completely read.
900 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
901 * Update the *data and *datalen variables.
902 * Return a Packet structure when a packet is completed.
904 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
906 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
908 crBegin(ssh->ssh1_rdpkt_crstate);
910 st->pktin = ssh_new_packet();
913 st->pktin->length = 0;
915 for (st->i = st->len = 0; st->i < 4; st->i++) {
916 while ((*datalen) == 0)
918 st->len = (st->len << 8) + **data;
919 (*data)++, (*datalen)--;
922 st->pad = 8 - (st->len % 8);
923 st->biglen = st->len + st->pad;
924 st->pktin->length = st->len - 5;
926 if (st->biglen < 0) {
927 bombout(("Extremely large packet length from server suggests"
928 " data stream corruption"));
929 ssh_free_packet(st->pktin);
933 st->pktin->maxlen = st->biglen;
934 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
936 st->to_read = st->biglen;
937 st->p = st->pktin->data;
938 while (st->to_read > 0) {
939 st->chunk = st->to_read;
940 while ((*datalen) == 0)
942 if (st->chunk > (*datalen))
943 st->chunk = (*datalen);
944 memcpy(st->p, *data, st->chunk);
946 *datalen -= st->chunk;
948 st->to_read -= st->chunk;
951 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
953 bombout(("Network attack (CRC compensation) detected!"));
954 ssh_free_packet(st->pktin);
959 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
961 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
962 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
963 if (st->gotcrc != st->realcrc) {
964 bombout(("Incorrect CRC received on packet"));
965 ssh_free_packet(st->pktin);
969 st->pktin->body = st->pktin->data + st->pad + 1;
970 st->pktin->savedpos = 0;
972 if (ssh->v1_compressing) {
973 unsigned char *decompblk;
975 if (!zlib_decompress_block(ssh->sc_comp_ctx,
976 st->pktin->body - 1, st->pktin->length + 1,
977 &decompblk, &decomplen)) {
978 bombout(("Zlib decompression encountered invalid data"));
979 ssh_free_packet(st->pktin);
983 if (st->pktin->maxlen < st->pad + decomplen) {
984 st->pktin->maxlen = st->pad + decomplen;
985 st->pktin->data = sresize(st->pktin->data,
986 st->pktin->maxlen + APIEXTRA,
988 st->pktin->body = st->pktin->data + st->pad + 1;
991 memcpy(st->pktin->body - 1, decompblk, decomplen);
993 st->pktin->length = decomplen - 1;
996 st->pktin->type = st->pktin->body[-1];
999 * Log incoming packet, possibly omitting sensitive fields.
1003 struct logblank_t blank;
1004 if (ssh->cfg.logomitdata) {
1005 int do_blank = FALSE, blank_prefix = 0;
1006 /* "Session data" packets - omit the data field */
1007 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1008 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1009 do_blank = TRUE; blank_prefix = 0;
1010 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1011 do_blank = TRUE; blank_prefix = 4;
1014 blank.offset = blank_prefix;
1015 blank.len = st->pktin->length;
1016 blank.type = PKTLOG_OMIT;
1020 log_packet(ssh->logctx,
1021 PKT_INCOMING, st->pktin->type,
1022 ssh1_pkt_type(st->pktin->type),
1023 st->pktin->body, st->pktin->length,
1027 crFinish(st->pktin);
1030 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1032 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1034 crBegin(ssh->ssh2_rdpkt_crstate);
1036 st->pktin = ssh_new_packet();
1038 st->pktin->type = 0;
1039 st->pktin->length = 0;
1041 st->cipherblk = ssh->sccipher->blksize;
1044 if (st->cipherblk < 8)
1047 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1050 * Acquire and decrypt the first block of the packet. This will
1051 * contain the length and padding details.
1053 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1054 while ((*datalen) == 0)
1056 st->pktin->data[st->i] = *(*data)++;
1061 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1062 st->pktin->data, st->cipherblk);
1065 * Now get the length and padding figures.
1067 st->len = GET_32BIT(st->pktin->data);
1068 st->pad = st->pktin->data[4];
1071 * _Completely_ silly lengths should be stomped on before they
1072 * do us any more damage.
1074 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1075 bombout(("Incoming packet was garbled on decryption"));
1076 ssh_free_packet(st->pktin);
1081 * This enables us to deduce the payload length.
1083 st->payload = st->len - st->pad - 1;
1085 st->pktin->length = st->payload + 5;
1088 * So now we can work out the total packet length.
1090 st->packetlen = st->len + 4;
1091 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1094 * Allocate memory for the rest of the packet.
1096 st->pktin->maxlen = st->packetlen + st->maclen;
1097 st->pktin->data = sresize(st->pktin->data,
1098 st->pktin->maxlen + APIEXTRA,
1102 * Read and decrypt the remainder of the packet.
1104 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1106 while ((*datalen) == 0)
1108 st->pktin->data[st->i] = *(*data)++;
1111 /* Decrypt everything _except_ the MAC. */
1113 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1114 st->pktin->data + st->cipherblk,
1115 st->packetlen - st->cipherblk);
1117 st->pktin->encrypted_len = st->packetlen;
1123 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1124 st->incoming_sequence)) {
1125 bombout(("Incorrect MAC received on packet"));
1126 ssh_free_packet(st->pktin);
1130 st->pktin->sequence = st->incoming_sequence++;
1133 * Decompress packet payload.
1136 unsigned char *newpayload;
1139 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1140 st->pktin->data + 5, st->pktin->length - 5,
1141 &newpayload, &newlen)) {
1142 if (st->pktin->maxlen < newlen + 5) {
1143 st->pktin->maxlen = newlen + 5;
1144 st->pktin->data = sresize(st->pktin->data,
1145 st->pktin->maxlen + APIEXTRA,
1148 st->pktin->length = 5 + newlen;
1149 memcpy(st->pktin->data + 5, newpayload, newlen);
1154 st->pktin->savedpos = 6;
1155 st->pktin->body = st->pktin->data;
1156 st->pktin->type = st->pktin->data[5];
1159 * Log incoming packet, possibly omitting sensitive fields.
1163 struct logblank_t blank;
1164 if (ssh->cfg.logomitdata) {
1165 int do_blank = FALSE, blank_prefix = 0;
1166 /* "Session data" packets - omit the data field */
1167 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1168 do_blank = TRUE; blank_prefix = 4;
1169 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1170 do_blank = TRUE; blank_prefix = 8;
1173 blank.offset = blank_prefix;
1174 blank.len = (st->pktin->length-6) - blank_prefix;
1175 blank.type = PKTLOG_OMIT;
1179 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1180 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1181 st->pktin->data+6, st->pktin->length-6,
1185 crFinish(st->pktin);
1188 static void ssh1_pktout_size(struct Packet *pkt, int len)
1192 len += 5; /* type and CRC */
1193 pad = 8 - (len % 8);
1196 pkt->length = len - 5;
1197 if (pkt->maxlen < biglen) {
1198 pkt->maxlen = biglen;
1199 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1201 pkt->body = pkt->data + 4 + pad + 1;
1204 static struct Packet *s_wrpkt_start(int type, int len)
1206 struct Packet *pkt = ssh_new_packet();
1207 ssh1_pktout_size(pkt, len);
1209 /* Initialise log omission state */
1215 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1221 * XXX various versions of SC (including 8.8.4) screw up the
1222 * register allocation in this function and use the same register
1223 * (D6) for len and as a temporary, with predictable results. The
1224 * following sledgehammer prevents this.
1230 pkt->body[-1] = pkt->type;
1233 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1234 ssh1_pkt_type(pkt->type),
1235 pkt->body, pkt->length,
1236 pkt->nblanks, pkt->blanks);
1237 sfree(pkt->blanks); pkt->blanks = NULL;
1240 if (ssh->v1_compressing) {
1241 unsigned char *compblk;
1243 zlib_compress_block(ssh->cs_comp_ctx,
1244 pkt->body - 1, pkt->length + 1,
1245 &compblk, &complen);
1246 ssh1_pktout_size(pkt, complen - 1);
1247 memcpy(pkt->body - 1, compblk, complen);
1251 len = pkt->length + 5; /* type and CRC */
1252 pad = 8 - (len % 8);
1255 for (i = 0; i < pad; i++)
1256 pkt->data[i + 4] = random_byte();
1257 crc = crc32_compute(pkt->data + 4, biglen - 4);
1258 PUT_32BIT(pkt->data + biglen, crc);
1259 PUT_32BIT(pkt->data, len);
1262 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1267 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1270 len = s_wrpkt_prepare(ssh, pkt);
1271 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1272 if (backlog > SSH_MAX_BACKLOG)
1273 ssh_throttle_all(ssh, 1, backlog);
1276 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1279 len = s_wrpkt_prepare(ssh, pkt);
1280 if (ssh->deferred_len + len > ssh->deferred_size) {
1281 ssh->deferred_size = ssh->deferred_len + len + 128;
1282 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1286 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1287 ssh->deferred_len += len;
1291 * Construct a packet with the specified contents.
1293 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1294 va_list ap1, va_list ap2)
1296 unsigned char *p, *argp, argchar;
1297 unsigned long argint;
1298 int pktlen, argtype, arglen;
1303 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1306 (void) va_arg(ap1, int);
1310 (void) va_arg(ap1, int);
1314 (void) va_arg(ap1, unsigned char *);
1315 arglen = va_arg(ap1, int);
1319 argp = va_arg(ap1, unsigned char *);
1320 arglen = strlen((char *)argp);
1321 pktlen += 4 + arglen;
1324 bn = va_arg(ap1, Bignum);
1325 pktlen += ssh1_bignum_length(bn);
1330 /* ignore this pass */
1337 pkt = s_wrpkt_start(pkttype, pktlen);
1340 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1341 int offset = p - pkt->body, len = 0;
1343 /* Actual fields in the packet */
1345 argint = va_arg(ap2, int);
1346 PUT_32BIT(p, argint);
1350 argchar = (unsigned char) va_arg(ap2, int);
1355 argp = va_arg(ap2, unsigned char *);
1356 arglen = va_arg(ap2, int);
1357 memcpy(p, argp, arglen);
1361 argp = va_arg(ap2, unsigned char *);
1362 arglen = strlen((char *)argp);
1363 PUT_32BIT(p, arglen);
1364 memcpy(p + 4, argp, arglen);
1368 bn = va_arg(ap2, Bignum);
1369 len = ssh1_write_bignum(p, bn);
1371 /* Tokens for modifications to packet logging */
1373 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1376 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1379 end_log_omission(ssh, pkt);
1383 /* Deal with logfile omission, if required. */
1384 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1386 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1388 pkt->blanks[pkt->nblanks-1].offset = offset;
1389 pkt->blanks[pkt->nblanks-1].len = len;
1390 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1397 static void send_packet(Ssh ssh, int pkttype, ...)
1401 va_start(ap1, pkttype);
1402 va_start(ap2, pkttype);
1403 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1407 ssh_free_packet(pkt);
1410 static void defer_packet(Ssh ssh, int pkttype, ...)
1414 va_start(ap1, pkttype);
1415 va_start(ap2, pkttype);
1416 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1419 s_wrpkt_defer(ssh, pkt);
1420 ssh_free_packet(pkt);
1423 static int ssh_versioncmp(char *a, char *b)
1426 unsigned long av, bv;
1428 av = strtoul(a, &ae, 10);
1429 bv = strtoul(b, &be, 10);
1431 return (av < bv ? -1 : +1);
1436 av = strtoul(ae, &ae, 10);
1437 bv = strtoul(be, &be, 10);
1439 return (av < bv ? -1 : +1);
1444 * Utility routines for putting an SSH-protocol `string' and
1445 * `uint32' into a SHA state.
1448 static void sha_string(SHA_State * s, void *str, int len)
1450 unsigned char lenblk[4];
1451 PUT_32BIT(lenblk, len);
1452 SHA_Bytes(s, lenblk, 4);
1453 SHA_Bytes(s, str, len);
1456 static void sha_uint32(SHA_State * s, unsigned i)
1458 unsigned char intblk[4];
1459 PUT_32BIT(intblk, i);
1460 SHA_Bytes(s, intblk, 4);
1464 * SSH2 packet construction functions.
1466 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1468 if (pkt->maxlen < length) {
1469 pkt->maxlen = length + 256;
1470 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1473 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1475 if (pkt->logmode != PKTLOG_EMIT) {
1477 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1478 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1479 pkt->blanks[pkt->nblanks-1].len = len;
1480 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1483 ssh2_pkt_ensure(pkt, pkt->length);
1484 memcpy(pkt->data + pkt->length - len, data, len);
1486 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1488 ssh2_pkt_adddata(pkt, &byte, 1);
1490 static struct Packet *ssh2_pkt_init(int pkt_type)
1492 struct Packet *pkt = ssh_new_packet();
1494 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1497 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1499 ssh2_pkt_adddata(pkt, &value, 1);
1501 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1504 PUT_32BIT(x, value);
1505 ssh2_pkt_adddata(pkt, x, 4);
1507 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1509 ssh2_pkt_adduint32(pkt, 0);
1510 pkt->savedpos = pkt->length;
1512 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1514 ssh2_pkt_adddata(pkt, data, strlen(data));
1515 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1517 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1519 ssh2_pkt_adddata(pkt, data, len);
1520 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1522 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1524 ssh2_pkt_addstring_start(pkt);
1525 ssh2_pkt_addstring_str(pkt, data);
1527 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1530 int i, n = (bignum_bitcount(b) + 7) / 8;
1531 p = snewn(n + 1, unsigned char);
1533 fatalbox("out of memory");
1535 for (i = 1; i <= n; i++)
1536 p[i] = bignum_byte(b, n - i);
1538 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1540 memmove(p, p + i, n + 1 - i);
1544 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1548 p = ssh2_mpint_fmt(b, &len);
1549 ssh2_pkt_addstring_start(pkt);
1550 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1555 * Construct an SSH2 final-form packet: compress it, encrypt it,
1556 * put the MAC on it. Final packet, ready to be sent, is stored in
1557 * pkt->data. Total length is returned.
1559 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1561 int cipherblk, maclen, padding, i;
1564 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1565 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1566 pkt->data + 6, pkt->length - 6,
1567 pkt->nblanks, pkt->blanks);
1568 sfree(pkt->blanks); pkt->blanks = NULL;
1572 * Compress packet payload.
1575 unsigned char *newpayload;
1578 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1580 &newpayload, &newlen)) {
1582 ssh2_pkt_adddata(pkt, newpayload, newlen);
1588 * Add padding. At least four bytes, and must also bring total
1589 * length (minus MAC) up to a multiple of the block size.
1591 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1592 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1595 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1596 maclen = ssh->csmac ? ssh->csmac->len : 0;
1597 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1598 pkt->data[4] = padding;
1599 for (i = 0; i < padding; i++)
1600 pkt->data[pkt->length + i] = random_byte();
1601 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1603 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1604 pkt->length + padding,
1605 ssh->v2_outgoing_sequence);
1606 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1609 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1610 pkt->data, pkt->length + padding);
1612 pkt->encrypted_len = pkt->length + padding;
1614 /* Ready-to-send packet starts at pkt->data. We return length. */
1615 return pkt->length + padding + maclen;
1619 * Routines called from the main SSH code to send packets. There
1620 * are quite a few of these, because we have two separate
1621 * mechanisms for delaying the sending of packets:
1623 * - In order to send an IGNORE message and a password message in
1624 * a single fixed-length blob, we require the ability to
1625 * concatenate the encrypted forms of those two packets _into_ a
1626 * single blob and then pass it to our <network.h> transport
1627 * layer in one go. Hence, there's a deferment mechanism which
1628 * works after packet encryption.
1630 * - In order to avoid sending any connection-layer messages
1631 * during repeat key exchange, we have to queue up any such
1632 * outgoing messages _before_ they are encrypted (and in
1633 * particular before they're allocated sequence numbers), and
1634 * then send them once we've finished.
1636 * I call these mechanisms `defer' and `queue' respectively, so as
1637 * to distinguish them reasonably easily.
1639 * The functions send_noqueue() and defer_noqueue() free the packet
1640 * structure they are passed. Every outgoing packet goes through
1641 * precisely one of these functions in its life; packets passed to
1642 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1643 * these or get queued, and then when the queue is later emptied
1644 * the packets are all passed to defer_noqueue().
1648 * Send an SSH2 packet immediately, without queuing or deferring.
1650 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1654 len = ssh2_pkt_construct(ssh, pkt);
1655 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1656 if (backlog > SSH_MAX_BACKLOG)
1657 ssh_throttle_all(ssh, 1, backlog);
1659 ssh->outgoing_data_size += pkt->encrypted_len;
1660 if (!ssh->kex_in_progress &&
1661 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1662 do_ssh2_transport(ssh, "Initiating key re-exchange "
1663 "(too much data sent)", -1, NULL);
1665 ssh_free_packet(pkt);
1669 * Defer an SSH2 packet.
1671 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1673 int len = ssh2_pkt_construct(ssh, pkt);
1674 if (ssh->deferred_len + len > ssh->deferred_size) {
1675 ssh->deferred_size = ssh->deferred_len + len + 128;
1676 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1680 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1681 ssh->deferred_len += len;
1682 ssh->deferred_data_size += pkt->encrypted_len;
1683 ssh_free_packet(pkt);
1687 * Queue an SSH2 packet.
1689 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1691 assert(ssh->queueing);
1693 if (ssh->queuelen >= ssh->queuesize) {
1694 ssh->queuesize = ssh->queuelen + 32;
1695 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1698 ssh->queue[ssh->queuelen++] = pkt;
1702 * Either queue or send a packet, depending on whether queueing is
1705 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1708 ssh2_pkt_queue(ssh, pkt);
1710 ssh2_pkt_send_noqueue(ssh, pkt);
1714 * Either queue or defer a packet, depending on whether queueing is
1717 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1720 ssh2_pkt_queue(ssh, pkt);
1722 ssh2_pkt_defer_noqueue(ssh, pkt);
1726 * Send the whole deferred data block constructed by
1727 * ssh2_pkt_defer() or SSH1's defer_packet().
1729 * The expected use of the defer mechanism is that you call
1730 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1731 * not currently queueing, this simply sets up deferred_send_data
1732 * and then sends it. If we _are_ currently queueing, the calls to
1733 * ssh2_pkt_defer() put the deferred packets on to the queue
1734 * instead, and therefore ssh_pkt_defersend() has no deferred data
1735 * to send. Hence, there's no need to make it conditional on
1738 static void ssh_pkt_defersend(Ssh ssh)
1741 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1743 ssh->deferred_len = ssh->deferred_size = 0;
1744 sfree(ssh->deferred_send_data);
1745 ssh->deferred_send_data = NULL;
1746 if (backlog > SSH_MAX_BACKLOG)
1747 ssh_throttle_all(ssh, 1, backlog);
1749 ssh->outgoing_data_size += ssh->deferred_data_size;
1750 if (!ssh->kex_in_progress &&
1751 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1752 do_ssh2_transport(ssh, "Initiating key re-exchange "
1753 "(too much data sent)", -1, NULL);
1754 ssh->deferred_data_size = 0;
1758 * Send all queued SSH2 packets. We send them by means of
1759 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1760 * packets that needed to be lumped together.
1762 static void ssh2_pkt_queuesend(Ssh ssh)
1766 assert(!ssh->queueing);
1768 for (i = 0; i < ssh->queuelen; i++)
1769 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1772 ssh_pkt_defersend(ssh);
1776 void bndebug(char *string, Bignum b)
1780 p = ssh2_mpint_fmt(b, &len);
1781 debug(("%s", string));
1782 for (i = 0; i < len; i++)
1783 debug((" %02x", p[i]));
1789 static void sha_mpint(SHA_State * s, Bignum b)
1793 p = ssh2_mpint_fmt(b, &len);
1794 sha_string(s, p, len);
1799 * Packet decode functions for both SSH1 and SSH2.
1801 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1803 unsigned long value;
1804 if (pkt->length - pkt->savedpos < 4)
1805 return 0; /* arrgh, no way to decline (FIXME?) */
1806 value = GET_32BIT(pkt->body + pkt->savedpos);
1810 static int ssh2_pkt_getbool(struct Packet *pkt)
1812 unsigned long value;
1813 if (pkt->length - pkt->savedpos < 1)
1814 return 0; /* arrgh, no way to decline (FIXME?) */
1815 value = pkt->body[pkt->savedpos] != 0;
1819 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1824 if (pkt->length - pkt->savedpos < 4)
1826 len = GET_32BIT(pkt->body + pkt->savedpos);
1831 if (pkt->length - pkt->savedpos < *length)
1833 *p = (char *)(pkt->body + pkt->savedpos);
1834 pkt->savedpos += *length;
1836 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1838 if (pkt->length - pkt->savedpos < length)
1840 pkt->savedpos += length;
1841 return pkt->body + (pkt->savedpos - length);
1843 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1844 unsigned char **keystr)
1848 j = makekey(pkt->body + pkt->savedpos,
1849 pkt->length - pkt->savedpos,
1856 assert(pkt->savedpos < pkt->length);
1860 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1865 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1866 pkt->length - pkt->savedpos, &b);
1874 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1880 ssh_pkt_getstring(pkt, &p, &length);
1885 b = bignum_from_bytes((unsigned char *)p, length);
1890 * Helper function to add an SSH2 signature blob to a packet.
1891 * Expects to be shown the public key blob as well as the signature
1892 * blob. Normally works just like ssh2_pkt_addstring, but will
1893 * fiddle with the signature packet if necessary for
1894 * BUG_SSH2_RSA_PADDING.
1896 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1897 void *pkblob_v, int pkblob_len,
1898 void *sigblob_v, int sigblob_len)
1900 unsigned char *pkblob = (unsigned char *)pkblob_v;
1901 unsigned char *sigblob = (unsigned char *)sigblob_v;
1903 /* dmemdump(pkblob, pkblob_len); */
1904 /* dmemdump(sigblob, sigblob_len); */
1907 * See if this is in fact an ssh-rsa signature and a buggy
1908 * server; otherwise we can just do this the easy way.
1910 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1911 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1912 int pos, len, siglen;
1915 * Find the byte length of the modulus.
1918 pos = 4+7; /* skip over "ssh-rsa" */
1919 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1920 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1921 pos += 4; /* find modulus itself */
1922 while (len > 0 && pkblob[pos] == 0)
1924 /* debug(("modulus length is %d\n", len)); */
1927 * Now find the signature integer.
1929 pos = 4+7; /* skip over "ssh-rsa" */
1930 siglen = GET_32BIT(sigblob+pos);
1931 /* debug(("signature length is %d\n", siglen)); */
1933 if (len != siglen) {
1934 unsigned char newlen[4];
1935 ssh2_pkt_addstring_start(pkt);
1936 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1937 /* dmemdump(sigblob, pos); */
1938 pos += 4; /* point to start of actual sig */
1939 PUT_32BIT(newlen, len);
1940 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1941 /* dmemdump(newlen, 4); */
1943 while (len-- > siglen) {
1944 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1945 /* dmemdump(newlen, 1); */
1947 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1948 /* dmemdump(sigblob+pos, siglen); */
1952 /* Otherwise fall through and do it the easy way. */
1955 ssh2_pkt_addstring_start(pkt);
1956 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1960 * Examine the remote side's version string and compare it against
1961 * a list of known buggy implementations.
1963 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1965 char *imp; /* pointer to implementation part */
1967 imp += strcspn(imp, "-");
1969 imp += strcspn(imp, "-");
1972 ssh->remote_bugs = 0;
1974 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1975 (ssh->cfg.sshbug_ignore1 == AUTO &&
1976 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1977 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1978 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1979 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1981 * These versions don't support SSH1_MSG_IGNORE, so we have
1982 * to use a different defence against password length
1985 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1986 logevent("We believe remote version has SSH1 ignore bug");
1989 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1990 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1991 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1993 * These versions need a plain password sent; they can't
1994 * handle having a null and a random length of data after
1997 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1998 logevent("We believe remote version needs a plain SSH1 password");
2001 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2002 (ssh->cfg.sshbug_rsa1 == AUTO &&
2003 (!strcmp(imp, "Cisco-1.25")))) {
2005 * These versions apparently have no clue whatever about
2006 * RSA authentication and will panic and die if they see
2007 * an AUTH_RSA message.
2009 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2010 logevent("We believe remote version can't handle RSA authentication");
2013 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2014 (ssh->cfg.sshbug_hmac2 == AUTO &&
2015 !wc_match("* VShell", imp) &&
2016 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2017 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2018 wc_match("2.1 *", imp)))) {
2020 * These versions have the HMAC bug.
2022 ssh->remote_bugs |= BUG_SSH2_HMAC;
2023 logevent("We believe remote version has SSH2 HMAC bug");
2026 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2027 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2028 !wc_match("* VShell", imp) &&
2029 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2031 * These versions have the key-derivation bug (failing to
2032 * include the literal shared secret in the hashes that
2033 * generate the keys).
2035 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2036 logevent("We believe remote version has SSH2 key-derivation bug");
2039 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2040 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2041 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2042 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2044 * These versions have the SSH2 RSA padding bug.
2046 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2047 logevent("We believe remote version has SSH2 RSA padding bug");
2050 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2051 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2052 wc_match("OpenSSH_2.[0-2]*", imp))) {
2054 * These versions have the SSH2 session-ID bug in
2055 * public-key authentication.
2057 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2058 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2061 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
2063 * User specified the SSH2 DH GEX bug.
2065 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
2066 logevent("We believe remote version has SSH2 DH group exchange 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, "\r\n")] = '\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\n", sshver);
2191 * Construct a v1 version string.
2193 verstring = dupprintf("SSH-%s-%s\n",
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, strlen(verstring)-1);
2208 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2211 * Initialise SSHv2 protocol.
2213 ssh->protocol = ssh2_protocol;
2214 ssh2_protocol_setup(ssh);
2215 ssh->s_rdpkt = ssh2_rdpkt;
2218 * Initialise SSHv1 protocol.
2220 ssh->protocol = ssh1_protocol;
2221 ssh1_protocol_setup(ssh);
2222 ssh->s_rdpkt = ssh1_rdpkt;
2224 logeventf(ssh, "We claim version: %.*s",
2225 strlen(verstring)-1, verstring);
2226 sk_write(ssh->s, verstring, strlen(verstring));
2230 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2232 update_specials_menu(ssh->frontend);
2233 ssh->state = SSH_STATE_BEFORE_SIZE;
2234 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2241 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2243 crBegin(ssh->ssh_gotdata_crstate);
2246 * To begin with, feed the characters one by one to the
2247 * protocol initialisation / selection function do_ssh_init().
2248 * When that returns 0, we're done with the initial greeting
2249 * exchange and can move on to packet discipline.
2252 int ret; /* need not be kept across crReturn */
2254 crReturnV; /* more data please */
2255 ret = do_ssh_init(ssh, *data);
2263 * We emerge from that loop when the initial negotiation is
2264 * over and we have selected an s_rdpkt function. Now pass
2265 * everything to s_rdpkt, and then pass the resulting packets
2266 * to the proper protocol handler.
2271 while (datalen > 0) {
2272 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2274 ssh->protocol(ssh, NULL, 0, pktin);
2275 ssh_free_packet(pktin);
2277 if (ssh->state == SSH_STATE_CLOSED)
2285 static void ssh_do_close(Ssh ssh)
2288 struct ssh_channel *c;
2290 ssh->state = SSH_STATE_CLOSED;
2294 notify_remote_exit(ssh->frontend);
2297 * Now we must shut down any port and X forwardings going
2298 * through this connection.
2300 if (ssh->channels) {
2301 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2304 x11_close(c->u.x11.s);
2307 pfd_close(c->u.pfd.s);
2310 del234(ssh->channels, c);
2311 if (ssh->version == 2)
2312 bufchain_clear(&c->v.v2.outbuffer);
2318 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2321 Ssh ssh = (Ssh) plug;
2324 /* A socket error has occurred. */
2325 logevent(error_msg);
2326 connection_fatal(ssh->frontend, "%s", error_msg);
2328 /* Otherwise, the remote side closed the connection normally. */
2333 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2335 Ssh ssh = (Ssh) plug;
2336 ssh_gotdata(ssh, (unsigned char *)data, len);
2337 if (ssh->state == SSH_STATE_CLOSED) {
2344 static void ssh_sent(Plug plug, int bufsize)
2346 Ssh ssh = (Ssh) plug;
2348 * If the send backlog on the SSH socket itself clears, we
2349 * should unthrottle the whole world if it was throttled.
2351 if (bufsize < SSH_MAX_BACKLOG)
2352 ssh_throttle_all(ssh, 0, bufsize);
2356 * Connect to specified host and port.
2357 * Returns an error message, or NULL on success.
2358 * Also places the canonical host name into `realhost'. It must be
2359 * freed by the caller.
2361 static const char *connect_to_host(Ssh ssh, char *host, int port,
2362 char **realhost, int nodelay, int keepalive)
2364 static const struct plug_function_table fn_table = {
2374 ssh->savedhost = snewn(1 + strlen(host), char);
2375 if (!ssh->savedhost)
2376 fatalbox("Out of memory");
2377 strcpy(ssh->savedhost, host);
2380 port = 22; /* default ssh port */
2381 ssh->savedport = port;
2386 logeventf(ssh, "Looking up host \"%s\"", host);
2387 addr = name_lookup(host, port, realhost, &ssh->cfg);
2388 if ((err = sk_addr_error(addr)) != NULL) {
2398 sk_getaddr(addr, addrbuf, 100);
2399 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2401 ssh->fn = &fn_table;
2402 ssh->s = new_connection(addr, *realhost, port,
2403 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2404 if ((err = sk_socket_error(ssh->s)) != NULL) {
2406 notify_remote_exit(ssh->frontend);
2414 * Throttle or unthrottle the SSH connection.
2416 static void ssh1_throttle(Ssh ssh, int adjust)
2418 int old_count = ssh->v1_throttle_count;
2419 ssh->v1_throttle_count += adjust;
2420 assert(ssh->v1_throttle_count >= 0);
2421 if (ssh->v1_throttle_count && !old_count) {
2422 sk_set_frozen(ssh->s, 1);
2423 } else if (!ssh->v1_throttle_count && old_count) {
2424 sk_set_frozen(ssh->s, 0);
2429 * Throttle or unthrottle _all_ local data streams (for when sends
2430 * on the SSH connection itself back up).
2432 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2435 struct ssh_channel *c;
2437 if (enable == ssh->throttled_all)
2439 ssh->throttled_all = enable;
2440 ssh->overall_bufsize = bufsize;
2443 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2445 case CHAN_MAINSESSION:
2447 * This is treated separately, outside the switch.
2451 x11_override_throttle(c->u.x11.s, enable);
2454 /* Agent channels require no buffer management. */
2457 pfd_override_throttle(c->u.pfd.s, enable);
2464 * Username and password input, abstracted off into routines
2465 * reusable in several places - even between SSH1 and SSH2.
2468 /* Set up a username or password input loop on a given buffer. */
2469 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2471 ssh->userpass_input_buffer = buffer;
2472 ssh->userpass_input_buflen = buflen;
2473 ssh->userpass_input_bufpos = 0;
2474 ssh->userpass_input_echo = echo;
2478 * Process some terminal data in the course of username/password
2479 * input. Returns >0 for success (line of input returned in
2480 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2481 * for inconclusive (keep waiting for more input please).
2483 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2488 switch (c = *in++) {
2491 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2492 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2497 if (ssh->userpass_input_bufpos > 0) {
2498 if (ssh->userpass_input_echo)
2499 c_write_str(ssh, "\b \b");
2500 ssh->userpass_input_bufpos--;
2505 while (ssh->userpass_input_bufpos > 0) {
2506 if (ssh->userpass_input_echo)
2507 c_write_str(ssh, "\b \b");
2508 ssh->userpass_input_bufpos--;
2517 * This simplistic check for printability is disabled
2518 * when we're doing password input, because some people
2519 * have control characters in their passwords.o
2521 if ((!ssh->userpass_input_echo ||
2522 (c >= ' ' && c <= '~') ||
2523 ((unsigned char) c >= 160))
2524 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2525 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2526 if (ssh->userpass_input_echo)
2527 c_write(ssh, &c, 1);
2535 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2537 Ssh ssh = (Ssh) sshv;
2539 ssh->agent_response = reply;
2540 ssh->agent_response_len = replylen;
2542 if (ssh->version == 1)
2543 do_ssh1_login(ssh, NULL, -1, NULL);
2545 do_ssh2_authconn(ssh, NULL, -1, NULL);
2548 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2550 struct ssh_channel *c = (struct ssh_channel *)cv;
2552 void *sentreply = reply;
2555 /* Fake SSH_AGENT_FAILURE. */
2556 sentreply = "\0\0\0\1\5";
2559 if (ssh->version == 2) {
2560 ssh2_add_channel_data(c, sentreply, replylen);
2563 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2564 PKT_INT, c->remoteid,
2567 PKT_DATA, sentreply, replylen,
2576 * Handle the key exchange and user authentication phases.
2578 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2579 struct Packet *pktin)
2582 unsigned char cookie[8], *ptr;
2583 struct RSAKey servkey, hostkey;
2584 struct MD5Context md5c;
2585 struct do_ssh1_login_state {
2587 unsigned char *rsabuf, *keystr1, *keystr2;
2588 unsigned long supported_ciphers_mask, supported_auths_mask;
2589 int tried_publickey, tried_agent;
2590 int tis_auth_refused, ccard_auth_refused;
2591 unsigned char session_id[16];
2594 void *publickey_blob;
2595 int publickey_bloblen;
2601 unsigned char request[5], *response, *p;
2610 crState(do_ssh1_login_state);
2612 crBegin(ssh->do_ssh1_login_crstate);
2617 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2618 bombout(("Public key packet not received"));
2622 logevent("Received public keys");
2624 ptr = ssh_pkt_getdata(pktin, 8);
2626 bombout(("SSH1 public key packet stopped before random cookie"));
2629 memcpy(cookie, ptr, 8);
2631 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2632 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2633 bombout(("Failed to read SSH1 public keys from public key packet"));
2638 * Log the host key fingerprint.
2642 logevent("Host key fingerprint is:");
2643 strcpy(logmsg, " ");
2644 hostkey.comment = NULL;
2645 rsa_fingerprint(logmsg + strlen(logmsg),
2646 sizeof(logmsg) - strlen(logmsg), &hostkey);
2650 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2651 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2652 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2654 ssh->v1_local_protoflags =
2655 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2656 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2659 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2660 MD5Update(&md5c, s->keystr1, servkey.bytes);
2661 MD5Update(&md5c, cookie, 8);
2662 MD5Final(s->session_id, &md5c);
2664 for (i = 0; i < 32; i++)
2665 ssh->session_key[i] = random_byte();
2668 * Verify that the `bits' and `bytes' parameters match.
2670 if (hostkey.bits > hostkey.bytes * 8 ||
2671 servkey.bits > servkey.bytes * 8) {
2672 bombout(("SSH1 public keys were badly formatted"));
2676 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2678 s->rsabuf = snewn(s->len, unsigned char);
2680 fatalbox("Out of memory");
2683 * Verify the host key.
2687 * First format the key into a string.
2689 int len = rsastr_len(&hostkey);
2690 char fingerprint[100];
2691 char *keystr = snewn(len, char);
2693 fatalbox("Out of memory");
2694 rsastr_fmt(keystr, &hostkey);
2695 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2696 verify_ssh_host_key(ssh->frontend,
2697 ssh->savedhost, ssh->savedport, "rsa", keystr,
2702 for (i = 0; i < 32; i++) {
2703 s->rsabuf[i] = ssh->session_key[i];
2705 s->rsabuf[i] ^= s->session_id[i];
2708 if (hostkey.bytes > servkey.bytes) {
2709 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2711 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2713 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2715 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2718 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2722 logevent("Encrypted session key");
2725 int cipher_chosen = 0, warn = 0;
2726 char *cipher_string = NULL;
2728 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2729 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2730 if (next_cipher == CIPHER_WARN) {
2731 /* If/when we choose a cipher, warn about it */
2733 } else if (next_cipher == CIPHER_AES) {
2734 /* XXX Probably don't need to mention this. */
2735 logevent("AES not supported in SSH1, skipping");
2737 switch (next_cipher) {
2738 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2739 cipher_string = "3DES"; break;
2740 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2741 cipher_string = "Blowfish"; break;
2742 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2743 cipher_string = "single-DES"; break;
2745 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2749 if (!cipher_chosen) {
2750 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2751 bombout(("Server violates SSH 1 protocol by not "
2752 "supporting 3DES encryption"));
2754 /* shouldn't happen */
2755 bombout(("No supported ciphers found"));
2759 /* Warn about chosen cipher if necessary. */
2761 askcipher(ssh->frontend, cipher_string, 0);
2764 switch (s->cipher_type) {
2765 case SSH_CIPHER_3DES:
2766 logevent("Using 3DES encryption");
2768 case SSH_CIPHER_DES:
2769 logevent("Using single-DES encryption");
2771 case SSH_CIPHER_BLOWFISH:
2772 logevent("Using Blowfish encryption");
2776 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2777 PKT_CHAR, s->cipher_type,
2778 PKT_DATA, cookie, 8,
2779 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2780 PKT_DATA, s->rsabuf, s->len,
2781 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2783 logevent("Trying to enable encryption...");
2787 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2788 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2790 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2791 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2792 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2794 ssh->crcda_ctx = crcda_make_context();
2795 logevent("Installing CRC compensation attack detector");
2797 if (servkey.modulus) {
2798 sfree(servkey.modulus);
2799 servkey.modulus = NULL;
2801 if (servkey.exponent) {
2802 sfree(servkey.exponent);
2803 servkey.exponent = NULL;
2805 if (hostkey.modulus) {
2806 sfree(hostkey.modulus);
2807 hostkey.modulus = NULL;
2809 if (hostkey.exponent) {
2810 sfree(hostkey.exponent);
2811 hostkey.exponent = NULL;
2815 if (pktin->type != SSH1_SMSG_SUCCESS) {
2816 bombout(("Encryption not successfully enabled"));
2820 logevent("Successfully started encryption");
2824 if (!*ssh->cfg.username) {
2825 if (ssh_get_line && !ssh_getline_pw_only) {
2826 if (!ssh_get_line("login as: ",
2827 s->username, sizeof(s->username), FALSE)) {
2829 * get_line failed to get a username.
2832 logevent("No username provided. Abandoning session.");
2833 ssh_closing((Plug)ssh, NULL, 0, 0);
2837 int ret; /* need not be kept over crReturn */
2838 c_write_str(ssh, "login as: ");
2841 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2843 crWaitUntil(!pktin);
2844 ret = process_userpass_input(ssh, in, inlen);
2848 c_write_str(ssh, "\r\n");
2851 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2852 s->username[sizeof(s->username)-1] = '\0';
2855 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2857 char userlog[22 + sizeof(s->username)];
2858 sprintf(userlog, "Sent username \"%s\"", s->username);
2860 if (flags & FLAG_INTERACTIVE &&
2861 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2862 strcat(userlog, "\r\n");
2863 c_write_str(ssh, userlog);
2870 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2871 /* We must not attempt PK auth. Pretend we've already tried it. */
2872 s->tried_publickey = s->tried_agent = 1;
2874 s->tried_publickey = s->tried_agent = 0;
2876 s->tis_auth_refused = s->ccard_auth_refused = 0;
2877 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2878 if (!filename_is_null(ssh->cfg.keyfile)) {
2879 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2880 &s->publickey_blob, &s->publickey_bloblen, NULL))
2881 s->publickey_blob = NULL;
2883 s->publickey_blob = NULL;
2885 while (pktin->type == SSH1_SMSG_FAILURE) {
2886 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2888 if (agent_exists() && !s->tried_agent) {
2890 * Attempt RSA authentication using Pageant.
2896 logevent("Pageant is running. Requesting keys.");
2898 /* Request the keys held by the agent. */
2899 PUT_32BIT(s->request, 1);
2900 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2901 if (!agent_query(s->request, 5, &r, &s->responselen,
2902 ssh_agent_callback, ssh)) {
2906 bombout(("Unexpected data from server while waiting"
2907 " for agent response"));
2910 } while (pktin || inlen > 0);
2911 r = ssh->agent_response;
2912 s->responselen = ssh->agent_response_len;
2914 s->response = (unsigned char *) r;
2915 if (s->response && s->responselen >= 5 &&
2916 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2917 s->p = s->response + 5;
2918 s->nkeys = GET_32BIT(s->p);
2922 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2925 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2928 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2931 if (s->publickey_blob &&
2932 !memcmp(s->p, s->publickey_blob,
2933 s->publickey_bloblen)) {
2934 logevent("This key matches configured key file");
2935 s->tried_publickey = 1;
2940 do { /* do while (0) to make breaking easy */
2941 n = ssh1_read_bignum
2942 (s->p, s->responselen-(s->p-s->response),
2947 n = ssh1_read_bignum
2948 (s->p, s->responselen-(s->p-s->response),
2953 if (s->responselen - (s->p-s->response) < 4)
2955 s->commentlen = GET_32BIT(s->p);
2957 if (s->responselen - (s->p-s->response) <
2960 s->commentp = (char *)s->p;
2961 s->p += s->commentlen;
2965 logevent("Pageant key list packet was truncated");
2969 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2970 PKT_BIGNUM, s->key.modulus, PKT_END);
2972 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2973 logevent("Key refused");
2976 logevent("Received RSA challenge");
2977 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
2978 bombout(("Server's RSA challenge was badly formatted"));
2983 char *agentreq, *q, *ret;
2986 len = 1 + 4; /* message type, bit count */
2987 len += ssh1_bignum_length(s->key.exponent);
2988 len += ssh1_bignum_length(s->key.modulus);
2989 len += ssh1_bignum_length(s->challenge);
2990 len += 16; /* session id */
2991 len += 4; /* response format */
2992 agentreq = snewn(4 + len, char);
2993 PUT_32BIT(agentreq, len);
2995 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2996 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2998 q += ssh1_write_bignum(q, s->key.exponent);
2999 q += ssh1_write_bignum(q, s->key.modulus);
3000 q += ssh1_write_bignum(q, s->challenge);
3001 memcpy(q, s->session_id, 16);
3003 PUT_32BIT(q, 1); /* response format */
3004 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3005 ssh_agent_callback, ssh)) {
3010 bombout(("Unexpected data from server"
3011 " while waiting for agent"
3015 } while (pktin || inlen > 0);
3016 vret = ssh->agent_response;
3017 retlen = ssh->agent_response_len;
3022 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3023 logevent("Sending Pageant's response");
3024 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3025 PKT_DATA, ret + 5, 16,
3029 if (pktin->type == SSH1_SMSG_SUCCESS) {
3031 ("Pageant's response accepted");
3032 if (flags & FLAG_VERBOSE) {
3033 c_write_str(ssh, "Authenticated using"
3035 c_write(ssh, s->commentp,
3037 c_write_str(ssh, "\" from agent\r\n");
3042 ("Pageant's response not accepted");
3045 ("Pageant failed to answer challenge");
3049 logevent("No reply received from Pageant");
3052 freebn(s->key.exponent);
3053 freebn(s->key.modulus);
3054 freebn(s->challenge);
3063 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3064 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3066 if (ssh->cfg.try_tis_auth &&
3067 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3068 !s->tis_auth_refused) {
3069 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3070 logevent("Requested TIS authentication");
3071 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3073 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3074 logevent("TIS authentication declined");
3075 if (flags & FLAG_INTERACTIVE)
3076 c_write_str(ssh, "TIS authentication refused.\r\n");
3077 s->tis_auth_refused = 1;
3083 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3085 bombout(("TIS challenge packet was badly formed"));
3088 logevent("Received TIS challenge");
3089 if (challengelen > sizeof(s->prompt) - 1)
3090 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3091 memcpy(s->prompt, challenge, challengelen);
3092 /* Prompt heuristic comes from OpenSSH */
3093 strncpy(s->prompt + challengelen,
3094 memchr(s->prompt, '\n', challengelen) ?
3095 "": "\r\nResponse: ",
3096 (sizeof s->prompt) - challengelen);
3097 s->prompt[(sizeof s->prompt) - 1] = '\0';
3100 if (ssh->cfg.try_tis_auth &&
3101 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3102 !s->ccard_auth_refused) {
3103 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3104 logevent("Requested CryptoCard authentication");
3105 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3107 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3108 logevent("CryptoCard authentication declined");
3109 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3110 s->ccard_auth_refused = 1;
3116 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3118 bombout(("CryptoCard challenge packet was badly formed"));
3121 logevent("Received CryptoCard challenge");
3122 if (challengelen > sizeof(s->prompt) - 1)
3123 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3124 memcpy(s->prompt, challenge, challengelen);
3125 strncpy(s->prompt + challengelen,
3126 memchr(s->prompt, '\n', challengelen) ?
3127 "" : "\r\nResponse: ",
3128 sizeof(s->prompt) - challengelen);
3129 s->prompt[sizeof(s->prompt) - 1] = '\0';
3132 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3133 sprintf(s->prompt, "%.90s@%.90s's password: ",
3134 s->username, ssh->savedhost);
3136 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3137 char *comment = NULL;
3140 if (flags & FLAG_VERBOSE)
3141 c_write_str(ssh, "Trying public key authentication.\r\n");
3142 logeventf(ssh, "Trying public key \"%s\"",
3143 filename_to_str(&ssh->cfg.keyfile));
3144 type = key_type(&ssh->cfg.keyfile);
3145 if (type != SSH_KEYTYPE_SSH1) {
3146 sprintf(msgbuf, "Key is of wrong type (%s)",
3147 key_type_to_str(type));
3149 c_write_str(ssh, msgbuf);
3150 c_write_str(ssh, "\r\n");
3151 s->tried_publickey = 1;
3154 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3155 if (flags & FLAG_VERBOSE)
3156 c_write_str(ssh, "No passphrase required.\r\n");
3159 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3164 * Show password prompt, having first obtained it via a TIS
3165 * or CryptoCard exchange if we're doing TIS or CryptoCard
3169 if (!ssh_get_line(s->prompt, s->password,
3170 sizeof(s->password), TRUE)) {
3172 * get_line failed to get a password (for example
3173 * because one was supplied on the command line
3174 * which has already failed to work). Terminate.
3176 send_packet(ssh, SSH1_MSG_DISCONNECT,
3177 PKT_STR, "No more passwords available to try",
3179 logevent("Unable to authenticate");
3180 connection_fatal(ssh->frontend, "Unable to authenticate");
3181 ssh_closing((Plug)ssh, NULL, 0, 0);
3185 /* Prompt may have come from server. We've munged it a bit, so
3186 * we know it to be zero-terminated at least once. */
3187 int ret; /* need not be saved over crReturn */
3188 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3191 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3193 crWaitUntil(!pktin);
3194 ret = process_userpass_input(ssh, in, inlen);
3198 c_write_str(ssh, "\r\n");
3202 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3204 * Try public key authentication with the specified
3207 s->tried_publickey = 1;
3210 const char *error = NULL;
3211 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3214 c_write_str(ssh, "Couldn't load private key from ");
3215 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3216 c_write_str(ssh, " (");
3217 c_write_str(ssh, error);
3218 c_write_str(ssh, ").\r\n");
3219 continue; /* go and try password */
3222 c_write_str(ssh, "Wrong passphrase.\r\n");
3223 s->tried_publickey = 0;
3224 continue; /* try again */
3229 * Send a public key attempt.
3231 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3232 PKT_BIGNUM, s->key.modulus, PKT_END);
3235 if (pktin->type == SSH1_SMSG_FAILURE) {
3236 c_write_str(ssh, "Server refused our public key.\r\n");
3237 continue; /* go and try password */
3239 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3240 bombout(("Bizarre response to offer of public key"));
3246 unsigned char buffer[32];
3247 Bignum challenge, response;
3249 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3250 bombout(("Server's RSA challenge was badly formatted"));
3253 response = rsadecrypt(challenge, &s->key);
3254 freebn(s->key.private_exponent);/* burn the evidence */
3256 for (i = 0; i < 32; i++) {
3257 buffer[i] = bignum_byte(response, 31 - i);
3261 MD5Update(&md5c, buffer, 32);
3262 MD5Update(&md5c, s->session_id, 16);
3263 MD5Final(buffer, &md5c);
3265 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3266 PKT_DATA, buffer, 16, PKT_END);
3273 if (pktin->type == SSH1_SMSG_FAILURE) {
3274 if (flags & FLAG_VERBOSE)
3275 c_write_str(ssh, "Failed to authenticate with"
3276 " our public key.\r\n");
3277 continue; /* go and try password */
3278 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3279 bombout(("Bizarre response to RSA authentication response"));
3283 break; /* we're through! */
3285 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3287 * Defence against traffic analysis: we send a
3288 * whole bunch of packets containing strings of
3289 * different lengths. One of these strings is the
3290 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3291 * The others are all random data in
3292 * SSH1_MSG_IGNORE packets. This way a passive
3293 * listener can't tell which is the password, and
3294 * hence can't deduce the password length.
3296 * Anybody with a password length greater than 16
3297 * bytes is going to have enough entropy in their
3298 * password that a listener won't find it _that_
3299 * much help to know how long it is. So what we'll
3302 * - if password length < 16, we send 15 packets
3303 * containing string lengths 1 through 15
3305 * - otherwise, we let N be the nearest multiple
3306 * of 8 below the password length, and send 8
3307 * packets containing string lengths N through
3308 * N+7. This won't obscure the order of
3309 * magnitude of the password length, but it will
3310 * introduce a bit of extra uncertainty.
3312 * A few servers (the old 1.2.18 through 1.2.22)
3313 * can't deal with SSH1_MSG_IGNORE. For these
3314 * servers, we need an alternative defence. We make
3315 * use of the fact that the password is interpreted
3316 * as a C string: so we can append a NUL, then some
3319 * One server (a Cisco one) can deal with neither
3320 * SSH1_MSG_IGNORE _nor_ a padded password string.
3321 * For this server we are left with no defences
3322 * against password length sniffing.
3324 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3326 * The server can deal with SSH1_MSG_IGNORE, so
3327 * we can use the primary defence.
3329 int bottom, top, pwlen, i;
3332 pwlen = strlen(s->password);
3334 bottom = 0; /* zero length passwords are OK! :-) */
3337 bottom = pwlen & ~7;
3341 assert(pwlen >= bottom && pwlen <= top);
3343 randomstr = snewn(top + 1, char);
3345 for (i = bottom; i <= top; i++) {
3347 defer_packet(ssh, s->pwpkt_type,
3348 PKTT_PASSWORD, PKT_STR, s->password,
3349 PKTT_OTHER, PKT_END);
3351 for (j = 0; j < i; j++) {
3353 randomstr[j] = random_byte();
3354 } while (randomstr[j] == '\0');
3356 randomstr[i] = '\0';
3357 defer_packet(ssh, SSH1_MSG_IGNORE,
3358 PKT_STR, randomstr, PKT_END);
3361 logevent("Sending password with camouflage packets");
3362 ssh_pkt_defersend(ssh);
3365 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3367 * The server can't deal with SSH1_MSG_IGNORE
3368 * but can deal with padded passwords, so we
3369 * can use the secondary defence.
3375 len = strlen(s->password);
3376 if (len < sizeof(string)) {
3378 strcpy(string, s->password);
3379 len++; /* cover the zero byte */
3380 while (len < sizeof(string)) {
3381 string[len++] = (char) random_byte();
3386 logevent("Sending length-padded password");
3387 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3388 PKT_INT, len, PKT_DATA, ss, len,
3389 PKTT_OTHER, PKT_END);
3392 * The server has _both_
3393 * BUG_CHOKES_ON_SSH1_IGNORE and
3394 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3395 * therefore nothing we can do.
3398 len = strlen(s->password);
3399 logevent("Sending unpadded password");
3400 send_packet(ssh, s->pwpkt_type,
3401 PKTT_PASSWORD, PKT_INT, len,
3402 PKT_DATA, s->password, len,
3403 PKTT_OTHER, PKT_END);
3406 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3407 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3410 logevent("Sent password");
3411 memset(s->password, 0, strlen(s->password));
3413 if (pktin->type == SSH1_SMSG_FAILURE) {
3414 if (flags & FLAG_VERBOSE)
3415 c_write_str(ssh, "Access denied\r\n");
3416 logevent("Authentication refused");
3417 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3418 bombout(("Strange packet received, type %d", pktin->type));
3423 logevent("Authentication successful");
3428 void sshfwd_close(struct ssh_channel *c)
3432 if (ssh->state != SSH_STATE_SESSION) {
3433 assert(ssh->state == SSH_STATE_CLOSED);
3437 if (c && !c->closes) {
3439 * If the channel's remoteid is -1, we have sent
3440 * CHANNEL_OPEN for this channel, but it hasn't even been
3441 * acknowledged by the server. So we must set a close flag
3442 * on it now, and then when the server acks the channel
3443 * open, we can close it then.
3445 if (((int)c->remoteid) != -1) {
3446 if (ssh->version == 1) {
3447 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3450 struct Packet *pktout;
3451 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3452 ssh2_pkt_adduint32(pktout, c->remoteid);
3453 ssh2_pkt_send(ssh, pktout);
3456 c->closes = 1; /* sent MSG_CLOSE */
3457 if (c->type == CHAN_X11) {
3459 logevent("Forwarded X11 connection terminated");
3460 } else if (c->type == CHAN_SOCKDATA ||
3461 c->type == CHAN_SOCKDATA_DORMANT) {
3463 logevent("Forwarded port closed");
3468 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3472 if (ssh->state != SSH_STATE_SESSION) {
3473 assert(ssh->state == SSH_STATE_CLOSED);
3477 if (ssh->version == 1) {
3478 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3479 PKT_INT, c->remoteid,
3481 PKT_INT, len, PKT_DATA, buf, len,
3482 PKTT_OTHER, PKT_END);
3484 * In SSH1 we can return 0 here - implying that forwarded
3485 * connections are never individually throttled - because
3486 * the only circumstance that can cause throttling will be
3487 * the whole SSH connection backing up, in which case
3488 * _everything_ will be throttled as a whole.
3492 ssh2_add_channel_data(c, buf, len);
3493 return ssh2_try_send(c);
3497 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3501 if (ssh->state != SSH_STATE_SESSION) {
3502 assert(ssh->state == SSH_STATE_CLOSED);
3506 if (ssh->version == 1) {
3507 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3508 c->v.v1.throttling = 0;
3509 ssh1_throttle(ssh, -1);
3512 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3516 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3519 int stringlen, bufsize;
3521 ssh_pkt_getstring(pktin, &string, &stringlen);
3522 if (string == NULL) {
3523 bombout(("Incoming terminal data packet was badly formed"));
3527 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3529 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3530 ssh->v1_stdout_throttling = 1;
3531 ssh1_throttle(ssh, +1);
3535 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3537 /* Remote side is trying to open a channel to talk to our
3538 * X-Server. Give them back a local channel number. */
3539 struct ssh_channel *c;
3540 int remoteid = ssh_pkt_getuint32(pktin);
3542 logevent("Received X11 connect request");
3543 /* Refuse if X11 forwarding is disabled. */
3544 if (!ssh->X11_fwd_enabled) {
3545 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3546 PKT_INT, remoteid, PKT_END);
3547 logevent("Rejected X11 connect request");
3549 c = snew(struct ssh_channel);
3552 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3553 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3554 logevent("Opening X11 forward connection failed");
3556 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3557 PKT_INT, remoteid, PKT_END);
3560 ("Opening X11 forward connection succeeded");
3561 c->remoteid = remoteid;
3562 c->localid = alloc_channel_id(ssh);
3564 c->v.v1.throttling = 0;
3565 c->type = CHAN_X11; /* identify channel type */
3566 add234(ssh->channels, c);
3567 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3568 PKT_INT, c->remoteid, PKT_INT,
3569 c->localid, PKT_END);
3570 logevent("Opened X11 forward channel");
3575 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3577 /* Remote side is trying to open a channel to talk to our
3578 * agent. Give them back a local channel number. */
3579 struct ssh_channel *c;
3580 int remoteid = ssh_pkt_getuint32(pktin);
3582 /* Refuse if agent forwarding is disabled. */
3583 if (!ssh->agentfwd_enabled) {
3584 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3585 PKT_INT, remoteid, PKT_END);
3587 c = snew(struct ssh_channel);
3589 c->remoteid = remoteid;
3590 c->localid = alloc_channel_id(ssh);
3592 c->v.v1.throttling = 0;
3593 c->type = CHAN_AGENT; /* identify channel type */
3594 c->u.a.lensofar = 0;
3595 add234(ssh->channels, c);
3596 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3597 PKT_INT, c->remoteid, PKT_INT, c->localid,
3602 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3604 /* Remote side is trying to open a channel to talk to a
3605 * forwarded port. Give them back a local channel number. */
3606 struct ssh_channel *c;
3607 struct ssh_rportfwd pf;
3610 char *host, buf[1024];
3612 c = snew(struct ssh_channel);
3615 remoteid = ssh_pkt_getuint32(pktin);
3616 ssh_pkt_getstring(pktin, &host, &hostsize);
3617 port = ssh_pkt_getuint32(pktin);
3619 if (hostsize >= lenof(pf.dhost))
3620 hostsize = lenof(pf.dhost)-1;
3621 memcpy(pf.dhost, host, hostsize);
3622 pf.dhost[hostsize] = '\0';
3625 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3626 sprintf(buf, "Rejected remote port open request for %s:%d",
3629 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3630 PKT_INT, remoteid, PKT_END);
3632 sprintf(buf, "Received remote port open request for %s:%d",
3635 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3639 sprintf(buf, "Port open failed: %s", e);
3642 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3643 PKT_INT, remoteid, PKT_END);
3645 c->remoteid = remoteid;
3646 c->localid = alloc_channel_id(ssh);
3648 c->v.v1.throttling = 0;
3649 c->type = CHAN_SOCKDATA; /* identify channel type */
3650 add234(ssh->channels, c);
3651 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3652 PKT_INT, c->remoteid, PKT_INT,
3653 c->localid, PKT_END);
3654 logevent("Forwarded port opened successfully");
3659 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3661 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3662 unsigned int localid = ssh_pkt_getuint32(pktin);
3663 struct ssh_channel *c;
3665 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3666 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3667 c->remoteid = localid;
3668 c->type = CHAN_SOCKDATA;
3669 c->v.v1.throttling = 0;
3670 pfd_confirm(c->u.pfd.s);
3673 if (c && c->closes) {
3675 * We have a pending close on this channel,
3676 * which we decided on before the server acked
3677 * the channel open. So now we know the
3678 * remoteid, we can close it again.
3680 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3681 PKT_INT, c->remoteid, PKT_END);
3685 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3687 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3688 struct ssh_channel *c;
3690 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3691 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3692 logevent("Forwarded connection refused by server");
3693 pfd_close(c->u.pfd.s);
3694 del234(ssh->channels, c);
3699 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3701 /* Remote side closes a channel. */
3702 unsigned i = ssh_pkt_getuint32(pktin);
3703 struct ssh_channel *c;
3704 c = find234(ssh->channels, &i, ssh_channelfind);
3705 if (c && ((int)c->remoteid) != -1) {
3708 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3710 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3711 logevent("Forwarded X11 connection terminated");
3712 assert(c->u.x11.s != NULL);
3713 x11_close(c->u.x11.s);
3716 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3717 logevent("Forwarded port closed");
3718 assert(c->u.pfd.s != NULL);
3719 pfd_close(c->u.pfd.s);
3723 c->closes |= (closetype << 2); /* seen this message */
3724 if (!(c->closes & closetype)) {
3725 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3727 c->closes |= closetype; /* sent it too */
3730 if (c->closes == 15) {
3731 del234(ssh->channels, c);
3735 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3736 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3737 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3742 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3744 /* Data sent down one of our channels. */
3745 int i = ssh_pkt_getuint32(pktin);
3748 struct ssh_channel *c;
3750 ssh_pkt_getstring(pktin, &p, &len);
3752 c = find234(ssh->channels, &i, ssh_channelfind);
3757 bufsize = x11_send(c->u.x11.s, p, len);
3760 bufsize = pfd_send(c->u.pfd.s, p, len);
3763 /* Data for an agent message. Buffer it. */
3765 if (c->u.a.lensofar < 4) {
3766 int l = min(4 - c->u.a.lensofar, len);
3767 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3771 c->u.a.lensofar += l;
3773 if (c->u.a.lensofar == 4) {
3775 4 + GET_32BIT(c->u.a.msglen);
3776 c->u.a.message = snewn(c->u.a.totallen,
3778 memcpy(c->u.a.message, c->u.a.msglen, 4);
3780 if (c->u.a.lensofar >= 4 && len > 0) {
3782 min(c->u.a.totallen - c->u.a.lensofar,
3784 memcpy(c->u.a.message + c->u.a.lensofar, p,
3788 c->u.a.lensofar += l;
3790 if (c->u.a.lensofar == c->u.a.totallen) {
3793 if (agent_query(c->u.a.message,
3796 ssh_agentf_callback, c))
3797 ssh_agentf_callback(c, reply, replylen);
3798 sfree(c->u.a.message);
3799 c->u.a.lensofar = 0;
3802 bufsize = 0; /* agent channels never back up */
3805 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3806 c->v.v1.throttling = 1;
3807 ssh1_throttle(ssh, +1);
3812 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3815 ssh->exitcode = ssh_pkt_getuint32(pktin);
3816 sprintf(buf, "Server sent command exit status %d",
3819 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3821 * In case `helpful' firewalls or proxies tack
3822 * extra human-readable text on the end of the
3823 * session which we might mistake for another
3824 * encrypted packet, we close the session once
3825 * we've sent EXIT_CONFIRMATION.
3827 ssh_closing((Plug)ssh, NULL, 0, 0);
3830 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3831 struct Packet *pktin)
3833 crBegin(ssh->do_ssh1_connection_crstate);
3835 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3836 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3837 ssh1_smsg_stdout_stderr_data;
3839 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3840 ssh1_msg_channel_open_confirmation;
3841 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3842 ssh1_msg_channel_open_failure;
3843 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3844 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3845 ssh1_msg_channel_close;
3846 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3847 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3849 if (ssh->cfg.agentfwd && agent_exists()) {
3850 logevent("Requesting agent forwarding");
3851 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3855 if (pktin->type != SSH1_SMSG_SUCCESS
3856 && pktin->type != SSH1_SMSG_FAILURE) {
3857 bombout(("Protocol confusion"));
3859 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3860 logevent("Agent forwarding refused");
3862 logevent("Agent forwarding enabled");
3863 ssh->agentfwd_enabled = TRUE;
3864 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
3868 if (ssh->cfg.x11_forward) {
3869 char proto[20], data[64];
3870 logevent("Requesting X11 forwarding");
3871 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3872 data, sizeof(data), ssh->cfg.x11_auth);
3873 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3874 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3875 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3876 PKT_STR, proto, PKT_STR, data,
3877 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3880 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3881 PKT_STR, proto, PKT_STR, data, PKT_END);
3886 if (pktin->type != SSH1_SMSG_SUCCESS
3887 && pktin->type != SSH1_SMSG_FAILURE) {
3888 bombout(("Protocol confusion"));
3890 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3891 logevent("X11 forwarding refused");
3893 logevent("X11 forwarding enabled");
3894 ssh->X11_fwd_enabled = TRUE;
3895 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
3902 int sport,dport,sserv,dserv;
3903 char sports[256], dports[256], saddr[256], host[256];
3905 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3906 /* Add port forwardings. */
3907 ssh->portfwd_strptr = ssh->cfg.portfwd;
3908 while (*ssh->portfwd_strptr) {
3909 type = *ssh->portfwd_strptr++;
3912 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3913 if (*ssh->portfwd_strptr == ':') {
3915 * We've seen a colon in the middle of the
3916 * source port number. This means that
3917 * everything we've seen until now is the
3918 * source _address_, so we'll move it into
3919 * saddr and start sports from the beginning
3922 ssh->portfwd_strptr++;
3924 strcpy(saddr, sports);
3927 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3931 if (*ssh->portfwd_strptr == '\t')
3932 ssh->portfwd_strptr++;
3934 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3935 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3938 if (*ssh->portfwd_strptr == ':')
3939 ssh->portfwd_strptr++;
3941 while (*ssh->portfwd_strptr) {
3942 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3945 ssh->portfwd_strptr++;
3946 dport = atoi(dports);
3950 dport = net_service_lookup(dports);
3952 logeventf(ssh, "Service lookup failed for"
3953 " destination port \"%s\"", dports);
3957 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3959 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3961 sport = atoi(sports);
3965 sport = net_service_lookup(sports);
3967 logeventf(ssh, "Service lookup failed for source"
3968 " port \"%s\"", sports);
3971 if (sport && dport) {
3972 /* Set up a description of the source port. */
3973 static char *sportdesc;
3974 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3975 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3976 (int)(*saddr?1:0), ":",
3977 (int)(sserv ? strlen(sports) : 0), sports,
3978 sserv, "(", sport, sserv, ")");
3980 /* Verbose description of the destination port */
3981 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3983 (int)(dserv ? strlen(dports) : 0), dports,
3984 dserv, "(", dport, dserv, ")");
3985 const char *err = pfd_addforward(host, dport,
3986 *saddr ? saddr : NULL,
3987 sport, ssh, &ssh->cfg);
3989 logeventf(ssh, "Local port %s forward to %s"
3990 " failed: %s", sportdesc, dportdesc, err);
3992 logeventf(ssh, "Local port %s forwarding to %s",
3993 sportdesc, dportdesc);
3996 } else if (type == 'D') {
3997 const char *err = pfd_addforward(NULL, -1,
3998 *saddr ? saddr : NULL,
3999 sport, ssh, &ssh->cfg);
4001 logeventf(ssh, "Local port %s SOCKS dynamic forward"
4002 " setup failed: %s", sportdesc, err);
4004 logeventf(ssh, "Local port %s doing SOCKS"
4005 " dynamic forwarding", sportdesc);
4008 struct ssh_rportfwd *pf;
4009 pf = snew(struct ssh_rportfwd);
4010 strcpy(pf->dhost, host);
4014 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
4017 if (add234(ssh->rportfwds, pf) != pf) {
4019 "Duplicate remote port forwarding to %s:%d",
4023 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
4024 " forward to %s:%.*s%.*s%d%.*s",
4025 (int)(sserv ? strlen(sports) : 0), sports,
4026 sserv, "(", sport, sserv, ")",
4028 (int)(dserv ? strlen(dports) : 0), dports,
4029 dserv, "(", dport, dserv, ")");
4030 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4038 if (pktin->type != SSH1_SMSG_SUCCESS
4039 && pktin->type != SSH1_SMSG_FAILURE) {
4040 bombout(("Protocol confusion"));
4042 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4043 c_write_str(ssh, "Server refused port"
4045 logevent("Server refused this port forwarding");
4047 logevent("Remote port forwarding enabled");
4048 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4058 if (!ssh->cfg.nopty) {
4059 /* Unpick the terminal-speed string. */
4060 /* XXX perhaps we should allow no speeds to be sent. */
4061 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4062 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4063 /* Send the pty request. */
4064 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4065 PKT_STR, ssh->cfg.termtype,
4066 PKT_INT, ssh->term_height,
4067 PKT_INT, ssh->term_width,
4068 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4069 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4070 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4071 PKT_CHAR, 0, PKT_END);
4072 ssh->state = SSH_STATE_INTERMED;
4076 if (pktin->type != SSH1_SMSG_SUCCESS
4077 && pktin->type != SSH1_SMSG_FAILURE) {
4078 bombout(("Protocol confusion"));
4080 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4081 c_write_str(ssh, "Server refused to allocate pty\r\n");
4082 ssh->editing = ssh->echoing = 1;
4084 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4085 ssh->ospeed, ssh->ispeed);
4087 ssh->editing = ssh->echoing = 1;
4090 if (ssh->cfg.compression) {
4091 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4095 if (pktin->type != SSH1_SMSG_SUCCESS
4096 && pktin->type != SSH1_SMSG_FAILURE) {
4097 bombout(("Protocol confusion"));
4099 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4100 c_write_str(ssh, "Server refused to compress\r\n");
4102 logevent("Started compression");
4103 ssh->v1_compressing = TRUE;
4104 ssh->cs_comp_ctx = zlib_compress_init();
4105 logevent("Initialised zlib (RFC1950) compression");
4106 ssh->sc_comp_ctx = zlib_decompress_init();
4107 logevent("Initialised zlib (RFC1950) decompression");
4111 * Start the shell or command.
4113 * Special case: if the first-choice command is an SSH2
4114 * subsystem (hence not usable here) and the second choice
4115 * exists, we fall straight back to that.
4118 char *cmd = ssh->cfg.remote_cmd_ptr;
4120 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4121 cmd = ssh->cfg.remote_cmd_ptr2;
4122 ssh->fallback_cmd = TRUE;
4125 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4127 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4128 logevent("Started session");
4131 ssh->state = SSH_STATE_SESSION;
4132 if (ssh->size_needed)
4133 ssh_size(ssh, ssh->term_width, ssh->term_height);
4134 if (ssh->eof_needed)
4135 ssh_special(ssh, TS_EOF);
4138 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4140 ssh->channels = newtree234(ssh_channelcmp);
4144 * By this point, most incoming packets are already being
4145 * handled by the dispatch table, and we need only pay
4146 * attention to the unusual ones.
4151 if (pktin->type == SSH1_SMSG_SUCCESS) {
4152 /* may be from EXEC_SHELL on some servers */
4153 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4154 /* may be from EXEC_SHELL on some servers
4155 * if no pty is available or in other odd cases. Ignore */
4157 bombout(("Strange packet received: type %d", pktin->type));
4162 int len = min(inlen, 512);
4163 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4164 PKT_INT, len, PKT_DATA, in, len,
4165 PKTT_OTHER, PKT_END);
4176 * Handle the top-level SSH2 protocol.
4178 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4183 ssh_pkt_getstring(pktin, &msg, &msglen);
4184 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4189 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4191 /* log reason code in disconnect message */
4195 ssh_pkt_getstring(pktin, &msg, &msglen);
4196 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4199 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4201 /* Do nothing, because we're ignoring it! Duhh. */
4204 static void ssh1_protocol_setup(Ssh ssh)
4209 * Most messages are handled by the coroutines.
4211 for (i = 0; i < 256; i++)
4212 ssh->packet_dispatch[i] = NULL;
4215 * These special message types we install handlers for.
4217 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4218 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4219 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4222 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4223 struct Packet *pktin)
4225 if (ssh->state == SSH_STATE_CLOSED)
4228 if (pktin && ssh->packet_dispatch[pktin->type]) {
4229 ssh->packet_dispatch[pktin->type](ssh, pktin);
4233 if (!ssh->protocol_initial_phase_done) {
4234 if (do_ssh1_login(ssh, in, inlen, pktin))
4235 ssh->protocol_initial_phase_done = TRUE;
4240 do_ssh1_connection(ssh, in, inlen, pktin);
4244 * Utility routine for decoding comma-separated strings in KEXINIT.
4246 static int in_commasep_string(char *needle, char *haystack, int haylen)
4249 if (!needle || !haystack) /* protect against null pointers */
4251 needlen = strlen(needle);
4254 * Is it at the start of the string?
4256 if (haylen >= needlen && /* haystack is long enough */
4257 !memcmp(needle, haystack, needlen) && /* initial match */
4258 (haylen == needlen || haystack[needlen] == ',')
4259 /* either , or EOS follows */
4263 * If not, search for the next comma and resume after that.
4264 * If no comma found, terminate.
4266 while (haylen > 0 && *haystack != ',')
4267 haylen--, haystack++;
4270 haylen--, haystack++; /* skip over comma itself */
4275 * SSH2 key creation method.
4277 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4278 unsigned char *sessid, char chr,
4279 unsigned char *keyspace)
4282 /* First 20 bytes. */
4284 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4286 SHA_Bytes(&s, H, 20);
4287 SHA_Bytes(&s, &chr, 1);
4288 SHA_Bytes(&s, sessid, 20);
4289 SHA_Final(&s, keyspace);
4290 /* Next 20 bytes. */
4292 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4294 SHA_Bytes(&s, H, 20);
4295 SHA_Bytes(&s, keyspace, 20);
4296 SHA_Final(&s, keyspace + 20);
4300 * Handle the SSH2 transport layer.
4302 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4303 struct Packet *pktin)
4305 struct do_ssh2_transport_state {
4306 int nbits, pbits, warn;
4307 Bignum p, g, e, f, K;
4308 int kex_init_value, kex_reply_value;
4309 const struct ssh_mac **maclist;
4311 const struct ssh2_cipher *cscipher_tobe;
4312 const struct ssh2_cipher *sccipher_tobe;
4313 const struct ssh_mac *csmac_tobe;
4314 const struct ssh_mac *scmac_tobe;
4315 const struct ssh_compress *cscomp_tobe;
4316 const struct ssh_compress *sccomp_tobe;
4317 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4318 int hostkeylen, siglen;
4319 void *hkey; /* actual host key */
4320 unsigned char exchange_hash[20];
4321 int n_preferred_ciphers;
4322 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4323 const struct ssh_compress *preferred_comp;
4325 struct Packet *pktout;
4327 crState(do_ssh2_transport_state);
4329 crBegin(ssh->do_ssh2_transport_crstate);
4331 s->cscipher_tobe = s->sccipher_tobe = NULL;
4332 s->csmac_tobe = s->scmac_tobe = NULL;
4333 s->cscomp_tobe = s->sccomp_tobe = NULL;
4340 * Set up the preferred ciphers. (NULL => warn below here)
4342 s->n_preferred_ciphers = 0;
4343 for (i = 0; i < CIPHER_MAX; i++) {
4344 switch (ssh->cfg.ssh_cipherlist[i]) {
4345 case CIPHER_BLOWFISH:
4346 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4349 if (ssh->cfg.ssh2_des_cbc) {
4350 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4354 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4357 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4360 /* Flag for later. Don't bother if it's the last in
4362 if (i < CIPHER_MAX - 1) {
4363 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4371 * Set up preferred compression.
4373 if (ssh->cfg.compression)
4374 s->preferred_comp = &ssh_zlib;
4376 s->preferred_comp = &ssh_comp_none;
4379 * Be prepared to work around the buggy MAC problem.
4381 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4382 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4384 s->maclist = macs, s->nmacs = lenof(macs);
4388 int i, j, cipherstr_started;
4391 * Enable queueing of outgoing auth- or connection-layer
4392 * packets while we are in the middle of a key exchange.
4394 ssh->queueing = TRUE;
4397 * Flag that KEX is in progress.
4399 ssh->kex_in_progress = TRUE;
4402 * Construct and send our key exchange packet.
4404 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4405 for (i = 0; i < 16; i++)
4406 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4407 /* List key exchange algorithms. */
4408 ssh2_pkt_addstring_start(s->pktout);
4409 for (i = 0; i < lenof(kex_algs); i++) {
4410 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4411 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4413 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
4414 if (i < lenof(kex_algs) - 1)
4415 ssh2_pkt_addstring_str(s->pktout, ",");
4417 /* List server host key algorithms. */
4418 ssh2_pkt_addstring_start(s->pktout);
4419 for (i = 0; i < lenof(hostkey_algs); i++) {
4420 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4421 if (i < lenof(hostkey_algs) - 1)
4422 ssh2_pkt_addstring_str(s->pktout, ",");
4424 /* List client->server encryption algorithms. */
4425 ssh2_pkt_addstring_start(s->pktout);
4426 cipherstr_started = 0;
4427 for (i = 0; i < s->n_preferred_ciphers; i++) {
4428 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4429 if (!c) continue; /* warning flag */
4430 for (j = 0; j < c->nciphers; j++) {
4431 if (cipherstr_started)
4432 ssh2_pkt_addstring_str(s->pktout, ",");
4433 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4434 cipherstr_started = 1;
4437 /* List server->client encryption algorithms. */
4438 ssh2_pkt_addstring_start(s->pktout);
4439 cipherstr_started = 0;
4440 for (i = 0; i < s->n_preferred_ciphers; i++) {
4441 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4442 if (!c) continue; /* warning flag */
4443 for (j = 0; j < c->nciphers; j++) {
4444 if (cipherstr_started)
4445 ssh2_pkt_addstring_str(s->pktout, ",");
4446 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4447 cipherstr_started = 1;
4450 /* List client->server MAC algorithms. */
4451 ssh2_pkt_addstring_start(s->pktout);
4452 for (i = 0; i < s->nmacs; i++) {
4453 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4454 if (i < s->nmacs - 1)
4455 ssh2_pkt_addstring_str(s->pktout, ",");
4457 /* List server->client MAC algorithms. */
4458 ssh2_pkt_addstring_start(s->pktout);
4459 for (i = 0; i < s->nmacs; i++) {
4460 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4461 if (i < s->nmacs - 1)
4462 ssh2_pkt_addstring_str(s->pktout, ",");
4464 /* List client->server compression algorithms. */
4465 ssh2_pkt_addstring_start(s->pktout);
4466 assert(lenof(compressions) > 1);
4467 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4468 for (i = 0; i < lenof(compressions); i++) {
4469 const struct ssh_compress *c = compressions[i];
4470 if (c != s->preferred_comp) {
4471 ssh2_pkt_addstring_str(s->pktout, ",");
4472 ssh2_pkt_addstring_str(s->pktout, c->name);
4475 /* List server->client compression algorithms. */
4476 ssh2_pkt_addstring_start(s->pktout);
4477 assert(lenof(compressions) > 1);
4478 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4479 for (i = 0; i < lenof(compressions); i++) {
4480 const struct ssh_compress *c = compressions[i];
4481 if (c != s->preferred_comp) {
4482 ssh2_pkt_addstring_str(s->pktout, ",");
4483 ssh2_pkt_addstring_str(s->pktout, c->name);
4486 /* List client->server languages. Empty list. */
4487 ssh2_pkt_addstring_start(s->pktout);
4488 /* List server->client languages. Empty list. */
4489 ssh2_pkt_addstring_start(s->pktout);
4490 /* First KEX packet does _not_ follow, because we're not that brave. */
4491 ssh2_pkt_addbool(s->pktout, FALSE);
4493 ssh2_pkt_adduint32(s->pktout, 0);
4496 ssh->exhash = ssh->exhashbase;
4497 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4499 ssh2_pkt_send_noqueue(ssh, s->pktout);
4503 if (pktin->length > 5)
4504 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4507 * Now examine the other side's KEXINIT to see what we're up
4514 if (pktin->type != SSH2_MSG_KEXINIT) {
4515 bombout(("expected key exchange packet from server"));
4519 ssh->hostkey = NULL;
4520 s->cscipher_tobe = NULL;
4521 s->sccipher_tobe = NULL;
4522 s->csmac_tobe = NULL;
4523 s->scmac_tobe = NULL;
4524 s->cscomp_tobe = NULL;
4525 s->sccomp_tobe = NULL;
4526 pktin->savedpos += 16; /* skip garbage cookie */
4527 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4528 for (i = 0; i < lenof(kex_algs); i++) {
4529 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4530 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4532 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4533 ssh->kex = kex_algs[i];
4537 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4538 for (i = 0; i < lenof(hostkey_algs); i++) {
4539 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4540 ssh->hostkey = hostkey_algs[i];
4544 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4546 for (i = 0; i < s->n_preferred_ciphers; i++) {
4547 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4551 for (j = 0; j < c->nciphers; j++) {
4552 if (in_commasep_string(c->list[j]->name, str, len)) {
4553 s->cscipher_tobe = c->list[j];
4558 if (s->cscipher_tobe) {
4560 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4564 if (!s->cscipher_tobe) {
4565 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4566 str ? str : "(null)"));
4570 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4572 for (i = 0; i < s->n_preferred_ciphers; i++) {
4573 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4577 for (j = 0; j < c->nciphers; j++) {
4578 if (in_commasep_string(c->list[j]->name, str, len)) {
4579 s->sccipher_tobe = c->list[j];
4584 if (s->sccipher_tobe) {
4586 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4590 if (!s->sccipher_tobe) {
4591 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4592 str ? str : "(null)"));
4596 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4597 for (i = 0; i < s->nmacs; i++) {
4598 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4599 s->csmac_tobe = s->maclist[i];
4603 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4604 for (i = 0; i < s->nmacs; i++) {
4605 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4606 s->scmac_tobe = s->maclist[i];
4610 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4611 for (i = 0; i < lenof(compressions) + 1; i++) {
4612 const struct ssh_compress *c =
4613 i == 0 ? s->preferred_comp : compressions[i - 1];
4614 if (in_commasep_string(c->name, str, len)) {
4619 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
4620 for (i = 0; i < lenof(compressions) + 1; i++) {
4621 const struct ssh_compress *c =
4622 i == 0 ? s->preferred_comp : compressions[i - 1];
4623 if (in_commasep_string(c->name, str, len)) {
4631 * Work out the number of bits of key we will need from the key
4632 * exchange. We start with the maximum key length of either
4638 csbits = s->cscipher_tobe->keylen;
4639 scbits = s->sccipher_tobe->keylen;
4640 s->nbits = (csbits > scbits ? csbits : scbits);
4642 /* The keys only have 160-bit entropy, since they're based on
4643 * a SHA-1 hash. So cap the key size at 160 bits. */
4648 * If we're doing Diffie-Hellman group exchange, start by
4649 * requesting a group.
4651 if (ssh->kex == &ssh_diffiehellman_gex) {
4652 logevent("Doing Diffie-Hellman group exchange");
4653 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4655 * Work out how big a DH group we will need to allow that
4658 s->pbits = 512 << ((s->nbits - 1) / 64);
4659 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4660 ssh2_pkt_adduint32(s->pktout, s->pbits);
4661 ssh2_pkt_send_noqueue(ssh, s->pktout);
4664 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4665 bombout(("expected key exchange group packet from server"));
4668 s->p = ssh2_pkt_getmp(pktin);
4669 s->g = ssh2_pkt_getmp(pktin);
4670 if (!s->p || !s->g) {
4671 bombout(("unable to read mp-ints from incoming group packet"));
4674 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4675 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4676 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4678 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4679 ssh->kex_ctx = dh_setup_group1();
4680 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4681 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4684 logevent("Doing Diffie-Hellman key exchange");
4686 * Now generate and send e for Diffie-Hellman.
4688 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4689 s->pktout = ssh2_pkt_init(s->kex_init_value);
4690 ssh2_pkt_addmp(s->pktout, s->e);
4691 ssh2_pkt_send_noqueue(ssh, s->pktout);
4694 if (pktin->type != s->kex_reply_value) {
4695 bombout(("expected key exchange reply packet from server"));
4698 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4699 s->f = ssh2_pkt_getmp(pktin);
4701 bombout(("unable to parse key exchange reply packet"));
4704 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
4706 s->K = dh_find_K(ssh->kex_ctx, s->f);
4708 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4709 if (ssh->kex == &ssh_diffiehellman_gex) {
4710 sha_uint32(&ssh->exhash, s->pbits);
4711 sha_mpint(&ssh->exhash, s->p);
4712 sha_mpint(&ssh->exhash, s->g);
4714 sha_mpint(&ssh->exhash, s->e);
4715 sha_mpint(&ssh->exhash, s->f);
4716 sha_mpint(&ssh->exhash, s->K);
4717 SHA_Final(&ssh->exhash, s->exchange_hash);
4719 dh_cleanup(ssh->kex_ctx);
4720 ssh->kex_ctx = NULL;
4723 debug(("Exchange hash is:\n"));
4724 dmemdump(s->exchange_hash, 20);
4727 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4729 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4730 (char *)s->exchange_hash, 20)) {
4731 bombout(("Server's host key did not match the signature supplied"));
4736 * Authenticate remote host: verify host key. (We've already
4737 * checked the signature of the exchange hash.)
4739 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4740 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4741 verify_ssh_host_key(ssh->frontend,
4742 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4743 s->keystr, s->fingerprint);
4744 if (s->first_kex) { /* don't bother logging this in rekeys */
4745 logevent("Host key fingerprint is:");
4746 logevent(s->fingerprint);
4748 sfree(s->fingerprint);
4750 ssh->hostkey->freekey(s->hkey);
4753 * The exchange hash from the very first key exchange is also
4754 * the session id, used in session key construction and
4758 memcpy(ssh->v2_session_id, s->exchange_hash,
4759 sizeof(s->exchange_hash));
4762 * Send SSH2_MSG_NEWKEYS.
4764 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
4765 ssh2_pkt_send_noqueue(ssh, s->pktout);
4766 ssh->outgoing_data_size = 0; /* start counting from here */
4769 * We've sent client NEWKEYS, so create and initialise
4770 * client-to-server session keys.
4772 if (ssh->cs_cipher_ctx)
4773 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4774 ssh->cscipher = s->cscipher_tobe;
4775 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4777 if (ssh->cs_mac_ctx)
4778 ssh->csmac->free_context(ssh->cs_mac_ctx);
4779 ssh->csmac = s->csmac_tobe;
4780 ssh->cs_mac_ctx = ssh->csmac->make_context();
4782 if (ssh->cs_comp_ctx)
4783 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4784 ssh->cscomp = s->cscomp_tobe;
4785 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4788 * Set IVs on client-to-server keys. Here we use the exchange
4789 * hash from the _first_ key exchange.
4792 unsigned char keyspace[40];
4793 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4794 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4795 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4796 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4797 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4798 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4801 logeventf(ssh, "Initialised %.200s client->server encryption",
4802 ssh->cscipher->text_name);
4803 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4804 ssh->csmac->text_name);
4805 if (ssh->cscomp->text_name)
4806 logeventf(ssh, "Initialised %s compression",
4807 ssh->cscomp->text_name);
4810 * Now our end of the key exchange is complete, we can send all
4811 * our queued higher-layer packets.
4813 ssh->queueing = FALSE;
4814 ssh2_pkt_queuesend(ssh);
4817 * Expect SSH2_MSG_NEWKEYS from server.
4820 if (pktin->type != SSH2_MSG_NEWKEYS) {
4821 bombout(("expected new-keys packet from server"));
4824 ssh->incoming_data_size = 0; /* start counting from here */
4827 * We've seen server NEWKEYS, so create and initialise
4828 * server-to-client session keys.
4830 if (ssh->sc_cipher_ctx)
4831 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4832 ssh->sccipher = s->sccipher_tobe;
4833 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4835 if (ssh->sc_mac_ctx)
4836 ssh->scmac->free_context(ssh->sc_mac_ctx);
4837 ssh->scmac = s->scmac_tobe;
4838 ssh->sc_mac_ctx = ssh->scmac->make_context();
4840 if (ssh->sc_comp_ctx)
4841 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4842 ssh->sccomp = s->sccomp_tobe;
4843 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4846 * Set IVs on server-to-client keys. Here we use the exchange
4847 * hash from the _first_ key exchange.
4850 unsigned char keyspace[40];
4851 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4852 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4853 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4854 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4855 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4856 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4858 logeventf(ssh, "Initialised %.200s server->client encryption",
4859 ssh->sccipher->text_name);
4860 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4861 ssh->scmac->text_name);
4862 if (ssh->sccomp->text_name)
4863 logeventf(ssh, "Initialised %s decompression",
4864 ssh->sccomp->text_name);
4867 * Free key exchange data.
4871 if (ssh->kex == &ssh_diffiehellman_gex) {
4877 * Key exchange is over. Schedule a timer for our next rekey.
4879 ssh->kex_in_progress = FALSE;
4880 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4883 * If this is the first key exchange phase, we must pass the
4884 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4885 * wants to see it but because it will need time to initialise
4886 * itself before it sees an actual packet. In subsequent key
4887 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4888 * it would only confuse the layer above.
4890 if (!s->first_kex) {
4896 * Now we're encrypting. Begin returning 1 to the protocol main
4897 * function so that other things can run on top of the
4898 * transport. If we ever see a KEXINIT, we must go back to the
4901 * We _also_ go back to the start if we see pktin==NULL and
4902 * inlen==-1, because this is a special signal meaning
4903 * `initiate client-driven rekey', and `in' contains a message
4904 * giving the reason for the rekey.
4906 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4907 (!pktin && inlen == -1))) {
4911 logevent("Server initiated key re-exchange");
4913 logevent((char *)in);
4915 goto begin_key_exchange;
4921 * Add data to an SSH2 channel output buffer.
4923 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4926 bufchain_add(&c->v.v2.outbuffer, buf, len);
4930 * Attempt to send data on an SSH2 channel.
4932 static int ssh2_try_send(struct ssh_channel *c)
4935 struct Packet *pktout;
4937 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4940 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4941 if ((unsigned)len > c->v.v2.remwindow)
4942 len = c->v.v2.remwindow;
4943 if ((unsigned)len > c->v.v2.remmaxpkt)
4944 len = c->v.v2.remmaxpkt;
4945 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4946 ssh2_pkt_adduint32(pktout, c->remoteid);
4947 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4948 ssh2_pkt_addstring_start(pktout);
4949 ssh2_pkt_addstring_data(pktout, data, len);
4950 end_log_omission(ssh, pktout);
4951 ssh2_pkt_send(ssh, pktout);
4952 bufchain_consume(&c->v.v2.outbuffer, len);
4953 c->v.v2.remwindow -= len;
4957 * After having sent as much data as we can, return the amount
4960 return bufchain_size(&c->v.v2.outbuffer);
4964 * Potentially enlarge the window on an SSH2 channel.
4966 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4971 * Never send WINDOW_ADJUST for a channel that the remote side
4972 * already thinks it's closed; there's no point, since it won't
4973 * be sending any more data anyway.
4978 if (newwin > c->v.v2.locwindow) {
4979 struct Packet *pktout;
4981 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4982 ssh2_pkt_adduint32(pktout, c->remoteid);
4983 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4984 ssh2_pkt_send(ssh, pktout);
4985 c->v.v2.locwindow = newwin;
4989 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
4991 unsigned i = ssh_pkt_getuint32(pktin);
4992 struct ssh_channel *c;
4993 c = find234(ssh->channels, &i, ssh_channelfind);
4994 if (c && !c->closes)
4995 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
4998 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5002 unsigned i = ssh_pkt_getuint32(pktin);
5003 struct ssh_channel *c;
5004 c = find234(ssh->channels, &i, ssh_channelfind);
5006 return; /* nonexistent channel */
5007 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5008 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5009 return; /* extended but not stderr */
5010 ssh_pkt_getstring(pktin, &data, &length);
5013 c->v.v2.locwindow -= length;
5015 case CHAN_MAINSESSION:
5017 from_backend(ssh->frontend, pktin->type ==
5018 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5022 bufsize = x11_send(c->u.x11.s, data, length);
5025 bufsize = pfd_send(c->u.pfd.s, data, length);
5028 while (length > 0) {
5029 if (c->u.a.lensofar < 4) {
5030 int l = min(4 - c->u.a.lensofar, length);
5031 memcpy(c->u.a.msglen + c->u.a.lensofar,
5035 c->u.a.lensofar += l;
5037 if (c->u.a.lensofar == 4) {
5039 4 + GET_32BIT(c->u.a.msglen);
5040 c->u.a.message = snewn(c->u.a.totallen,
5042 memcpy(c->u.a.message, c->u.a.msglen, 4);
5044 if (c->u.a.lensofar >= 4 && length > 0) {
5046 min(c->u.a.totallen - c->u.a.lensofar,
5048 memcpy(c->u.a.message + c->u.a.lensofar,
5052 c->u.a.lensofar += l;
5054 if (c->u.a.lensofar == c->u.a.totallen) {
5057 if (agent_query(c->u.a.message,
5060 ssh_agentf_callback, c))
5061 ssh_agentf_callback(c, reply, replylen);
5062 sfree(c->u.a.message);
5063 c->u.a.lensofar = 0;
5070 * If we are not buffering too much data,
5071 * enlarge the window again at the remote side.
5073 if (bufsize < OUR_V2_WINSIZE)
5074 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5078 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5080 unsigned i = ssh_pkt_getuint32(pktin);
5081 struct ssh_channel *c;
5083 c = find234(ssh->channels, &i, ssh_channelfind);
5085 return; /* nonexistent channel */
5087 if (c->type == CHAN_X11) {
5089 * Remote EOF on an X11 channel means we should
5090 * wrap up and close the channel ourselves.
5092 x11_close(c->u.x11.s);
5094 } else if (c->type == CHAN_AGENT) {
5096 } else if (c->type == CHAN_SOCKDATA) {
5097 pfd_close(c->u.pfd.s);
5102 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5104 unsigned i = ssh_pkt_getuint32(pktin);
5105 struct ssh_channel *c;
5106 struct Packet *pktout;
5108 c = find234(ssh->channels, &i, ssh_channelfind);
5109 if (!c || ((int)c->remoteid) == -1) {
5110 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5111 c ? "half-open" : "nonexistent", i));
5114 /* Do pre-close processing on the channel. */
5116 case CHAN_MAINSESSION:
5117 ssh->mainchan = NULL;
5118 update_specials_menu(ssh->frontend);
5121 if (c->u.x11.s != NULL)
5122 x11_close(c->u.x11.s);
5129 if (c->u.pfd.s != NULL)
5130 pfd_close(c->u.pfd.s);
5134 if (c->closes == 0) {
5135 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5136 ssh2_pkt_adduint32(pktout, c->remoteid);
5137 ssh2_pkt_send(ssh, pktout);
5139 del234(ssh->channels, c);
5140 bufchain_clear(&c->v.v2.outbuffer);
5144 * See if that was the last channel left open.
5145 * (This is only our termination condition if we're
5146 * not running in -N mode.)
5148 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5149 logevent("All channels closed. Disconnecting");
5152 * We used to send SSH_MSG_DISCONNECT here,
5153 * because I'd believed that _every_ conforming
5154 * SSH2 connection had to end with a disconnect
5155 * being sent by at least one side; apparently
5156 * I was wrong and it's perfectly OK to
5157 * unceremoniously slam the connection shut
5158 * when you're done, and indeed OpenSSH feels
5159 * this is more polite than sending a
5160 * DISCONNECT. So now we don't.
5162 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5163 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5164 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5165 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5166 ssh2_pkt_send_noqueue(ssh, s->pktout);
5168 ssh_closing((Plug)ssh, NULL, 0, 0);
5172 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5174 unsigned i = ssh_pkt_getuint32(pktin);
5175 struct ssh_channel *c;
5176 struct Packet *pktout;
5178 c = find234(ssh->channels, &i, ssh_channelfind);
5180 return; /* nonexistent channel */
5181 if (c->type != CHAN_SOCKDATA_DORMANT)
5182 return; /* dunno why they're confirming this */
5183 c->remoteid = ssh_pkt_getuint32(pktin);
5184 c->type = CHAN_SOCKDATA;
5185 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5186 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5188 pfd_confirm(c->u.pfd.s);
5191 * We have a pending close on this channel,
5192 * which we decided on before the server acked
5193 * the channel open. So now we know the
5194 * remoteid, we can close it again.
5196 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5197 ssh2_pkt_adduint32(pktout, c->remoteid);
5198 ssh2_pkt_send(ssh, pktout);
5202 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5204 static const char *const reasons[] = {
5205 "<unknown reason code>",
5206 "Administratively prohibited",
5208 "Unknown channel type",
5209 "Resource shortage",
5211 unsigned i = ssh_pkt_getuint32(pktin);
5212 unsigned reason_code;
5213 char *reason_string;
5216 struct ssh_channel *c;
5217 c = find234(ssh->channels, &i, ssh_channelfind);
5219 return; /* nonexistent channel */
5220 if (c->type != CHAN_SOCKDATA_DORMANT)
5221 return; /* dunno why they're failing this */
5223 reason_code = ssh_pkt_getuint32(pktin);
5224 if (reason_code >= lenof(reasons))
5225 reason_code = 0; /* ensure reasons[reason_code] in range */
5226 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5227 message = dupprintf("Forwarded connection refused by"
5228 " server: %s [%.*s]", reasons[reason_code],
5229 reason_length, reason_string);
5233 pfd_close(c->u.pfd.s);
5235 del234(ssh->channels, c);
5239 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5243 int typelen, want_reply;
5244 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5245 struct ssh_channel *c;
5246 struct Packet *pktout;
5248 localid = ssh_pkt_getuint32(pktin);
5249 ssh_pkt_getstring(pktin, &type, &typelen);
5250 want_reply = ssh2_pkt_getbool(pktin);
5253 * First, check that the channel exists. Otherwise,
5254 * we can instantly disconnect with a rude message.
5256 c = find234(ssh->channels, &localid, ssh_channelfind);
5259 sprintf(buf, "Received channel request for nonexistent"
5260 " channel %d", localid);
5262 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5263 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5264 ssh2_pkt_addstring(pktout, buf);
5265 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5266 ssh2_pkt_send_noqueue(ssh, pktout);
5267 connection_fatal(ssh->frontend, "%s", buf);
5268 ssh_closing((Plug)ssh, NULL, 0, 0);
5273 * Having got the channel number, we now look at
5274 * the request type string to see if it's something
5277 if (c == ssh->mainchan) {
5279 * We recognise "exit-status" and "exit-signal" on
5280 * the primary channel.
5282 if (typelen == 11 &&
5283 !memcmp(type, "exit-status", 11)) {
5285 ssh->exitcode = ssh_pkt_getuint32(pktin);
5286 logeventf(ssh, "Server sent command exit status %d",
5288 reply = SSH2_MSG_CHANNEL_SUCCESS;
5290 } else if (typelen == 11 &&
5291 !memcmp(type, "exit-signal", 11)) {
5293 int is_plausible = TRUE, is_int = FALSE;
5294 char *fmt_sig = "", *fmt_msg = "";
5296 int msglen = 0, core = FALSE;
5297 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5298 * provide an `int' for the signal, despite its
5299 * having been a `string' in the drafts since at
5300 * least 2001. (Fixed in session.c 1.147.) Try to
5301 * infer which we can safely parse it as. */
5303 unsigned char *p = pktin->body +
5305 long len = pktin->length - pktin->savedpos;
5306 unsigned long num = GET_32BIT(p); /* what is it? */
5307 /* If it's 0, it hardly matters; assume string */
5311 int maybe_int = FALSE, maybe_str = FALSE;
5312 #define CHECK_HYPOTHESIS(offset, result) \
5315 if (q >= 0 && q+4 <= len) { \
5316 q = q + 4 + GET_32BIT(p+q); \
5317 if (q >= 0 && q+4 <= len && \
5318 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5322 CHECK_HYPOTHESIS(4+1, maybe_int);
5323 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5324 #undef CHECK_HYPOTHESIS
5325 if (maybe_int && !maybe_str)
5327 else if (!maybe_int && maybe_str)
5330 /* Crikey. Either or neither. Panic. */
5331 is_plausible = FALSE;
5336 /* Old non-standard OpenSSH. */
5337 int signum = ssh_pkt_getuint32(pktin);
5338 fmt_sig = dupprintf(" %d", signum);
5340 /* As per the drafts. */
5343 ssh_pkt_getstring(pktin, &sig, &siglen);
5344 /* Signal name isn't supposed to be blank, but
5345 * let's cope gracefully if it is. */
5347 fmt_sig = dupprintf(" \"%.*s\"",
5351 core = ssh2_pkt_getbool(pktin);
5352 ssh_pkt_getstring(pktin, &msg, &msglen);
5354 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5356 /* ignore lang tag */
5357 } /* else don't attempt to parse */
5358 logeventf(ssh, "Server exited on signal%s%s%s",
5359 fmt_sig, core ? " (core dumped)" : "",
5361 if (*fmt_sig) sfree(fmt_sig);
5362 if (*fmt_msg) sfree(fmt_msg);
5363 reply = SSH2_MSG_CHANNEL_SUCCESS;
5368 * This is a channel request we don't know
5369 * about, so we now either ignore the request
5370 * or respond with CHANNEL_FAILURE, depending
5373 reply = SSH2_MSG_CHANNEL_FAILURE;
5376 pktout = ssh2_pkt_init(reply);
5377 ssh2_pkt_adduint32(pktout, c->remoteid);
5378 ssh2_pkt_send(ssh, pktout);
5382 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5385 int typelen, want_reply;
5386 struct Packet *pktout;
5388 ssh_pkt_getstring(pktin, &type, &typelen);
5389 want_reply = ssh2_pkt_getbool(pktin);
5392 * We currently don't support any global requests
5393 * at all, so we either ignore the request or
5394 * respond with REQUEST_FAILURE, depending on
5398 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5399 ssh2_pkt_send(ssh, pktout);
5403 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5411 struct ssh_channel *c;
5412 unsigned remid, winsize, pktsize;
5413 struct Packet *pktout;
5415 ssh_pkt_getstring(pktin, &type, &typelen);
5416 c = snew(struct ssh_channel);
5419 remid = ssh_pkt_getuint32(pktin);
5420 winsize = ssh_pkt_getuint32(pktin);
5421 pktsize = ssh_pkt_getuint32(pktin);
5423 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5426 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5427 addrstr = snewn(peeraddrlen+1, char);
5428 memcpy(addrstr, peeraddr, peeraddrlen);
5429 addrstr[peeraddrlen] = '\0';
5430 peerport = ssh_pkt_getuint32(pktin);
5432 logeventf(ssh, "Received X11 connect request from %s:%d",
5435 if (!ssh->X11_fwd_enabled)
5436 error = "X11 forwarding is not enabled";
5437 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5438 ssh->x11auth, addrstr, peerport,
5439 &ssh->cfg) != NULL) {
5440 error = "Unable to open an X11 connection";
5442 logevent("Opening X11 forward connection succeeded");
5447 } else if (typelen == 15 &&
5448 !memcmp(type, "forwarded-tcpip", 15)) {
5449 struct ssh_rportfwd pf, *realpf;
5452 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5453 pf.sport = ssh_pkt_getuint32(pktin);
5454 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5455 peerport = ssh_pkt_getuint32(pktin);
5456 realpf = find234(ssh->rportfwds, &pf, NULL);
5457 logeventf(ssh, "Received remote port %d open request "
5458 "from %s:%d", pf.sport, peeraddr, peerport);
5459 if (realpf == NULL) {
5460 error = "Remote port is not recognised";
5462 const char *e = pfd_newconnect(&c->u.pfd.s,
5466 logeventf(ssh, "Attempting to forward remote port to "
5467 "%s:%d", realpf->dhost, realpf->dport);
5469 logeventf(ssh, "Port open failed: %s", e);
5470 error = "Port open failed";
5472 logevent("Forwarded port opened successfully");
5473 c->type = CHAN_SOCKDATA;
5476 } else if (typelen == 22 &&
5477 !memcmp(type, "auth-agent@openssh.com", 3)) {
5478 if (!ssh->agentfwd_enabled)
5479 error = "Agent forwarding is not enabled";
5481 c->type = CHAN_AGENT; /* identify channel type */
5482 c->u.a.lensofar = 0;
5485 error = "Unsupported channel type requested";
5488 c->remoteid = remid;
5490 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5491 ssh2_pkt_adduint32(pktout, c->remoteid);
5492 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5493 ssh2_pkt_addstring(pktout, error);
5494 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5495 ssh2_pkt_send(ssh, pktout);
5496 logeventf(ssh, "Rejected channel open: %s", error);
5499 c->localid = alloc_channel_id(ssh);
5501 c->v.v2.locwindow = OUR_V2_WINSIZE;
5502 c->v.v2.remwindow = winsize;
5503 c->v.v2.remmaxpkt = pktsize;
5504 bufchain_init(&c->v.v2.outbuffer);
5505 add234(ssh->channels, c);
5506 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5507 ssh2_pkt_adduint32(pktout, c->remoteid);
5508 ssh2_pkt_adduint32(pktout, c->localid);
5509 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5510 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5511 ssh2_pkt_send(ssh, pktout);
5516 * Handle the SSH2 userauth and connection layers.
5518 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5519 struct Packet *pktin)
5521 struct do_ssh2_authconn_state {
5523 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5525 AUTH_KEYBOARD_INTERACTIVE
5529 AUTH_TYPE_PUBLICKEY,
5530 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5531 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5533 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5534 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5536 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5537 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5538 int kbd_inter_running;
5540 int num_prompts, curr_prompt, echo;
5545 void *publickey_blob;
5546 int publickey_bloblen;
5547 unsigned char request[5], *response, *p;
5551 char *pkblob, *alg, *commentp;
5552 int pklen, alglen, commentlen;
5553 int siglen, retlen, len;
5554 char *q, *agentreq, *ret;
5556 int num_env, env_left, env_ok;
5557 struct Packet *pktout;
5559 crState(do_ssh2_authconn_state);
5561 crBegin(ssh->do_ssh2_authconn_crstate);
5564 * Request userauth protocol, and await a response to it.
5566 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5567 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5568 ssh2_pkt_send(ssh, s->pktout);
5569 crWaitUntilV(pktin);
5570 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5571 bombout(("Server refused user authentication protocol"));
5576 * We repeat this whole loop, including the username prompt,
5577 * until we manage a successful authentication. If the user
5578 * types the wrong _password_, they can be sent back to the
5579 * beginning to try another username, if this is configured on.
5580 * (If they specify a username in the config, they are never
5581 * asked, even if they do give a wrong password.)
5583 * I think this best serves the needs of
5585 * - the people who have no configuration, no keys, and just
5586 * want to try repeated (username,password) pairs until they
5587 * type both correctly
5589 * - people who have keys and configuration but occasionally
5590 * need to fall back to passwords
5592 * - people with a key held in Pageant, who might not have
5593 * logged in to a particular machine before; so they want to
5594 * type a username, and then _either_ their key will be
5595 * accepted, _or_ they will type a password. If they mistype
5596 * the username they will want to be able to get back and
5599 s->username[0] = '\0';
5600 s->got_username = FALSE;
5605 if (s->got_username && !ssh->cfg.change_username) {
5607 * We got a username last time round this loop, and
5608 * with change_username turned off we don't try to get
5611 } else if (!*ssh->cfg.username) {
5612 if (ssh_get_line && !ssh_getline_pw_only) {
5613 if (!ssh_get_line("login as: ",
5614 s->username, sizeof(s->username), FALSE)) {
5616 * get_line failed to get a username.
5619 logevent("No username provided. Abandoning session.");
5620 ssh_closing((Plug)ssh, NULL, 0, 0);
5624 int ret; /* need not be saved across crReturn */
5625 c_write_str(ssh, "login as: ");
5627 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
5629 crWaitUntilV(!pktin);
5630 ret = process_userpass_input(ssh, in, inlen);
5634 c_write_str(ssh, "\r\n");
5636 s->username[strcspn(s->username, "\n\r")] = '\0';
5639 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
5640 s->username[sizeof(s->username)-1] = '\0';
5641 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
5642 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
5643 c_write_str(ssh, stuff);
5647 s->got_username = TRUE;
5650 * Send an authentication request using method "none": (a)
5651 * just in case it succeeds, and (b) so that we know what
5652 * authentication methods we can usefully try next.
5654 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5656 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5657 ssh2_pkt_addstring(s->pktout, s->username);
5658 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5659 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5660 ssh2_pkt_send(ssh, s->pktout);
5661 s->type = AUTH_TYPE_NONE;
5663 s->we_are_in = FALSE;
5665 s->tried_pubkey_config = FALSE;
5666 s->tried_agent = FALSE;
5667 s->tried_keyb_inter = FALSE;
5668 s->kbd_inter_running = FALSE;
5669 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
5670 if (!filename_is_null(ssh->cfg.keyfile)) {
5672 logeventf(ssh, "Reading private key file \"%.150s\"",
5673 filename_to_str(&ssh->cfg.keyfile));
5674 keytype = key_type(&ssh->cfg.keyfile);
5675 if (keytype == SSH_KEYTYPE_SSH2) {
5677 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
5678 &s->publickey_bloblen, NULL);
5681 logeventf(ssh, "Unable to use this key file (%s)",
5682 key_type_to_str(keytype));
5683 msgbuf = dupprintf("Unable to use key file \"%.150s\""
5685 filename_to_str(&ssh->cfg.keyfile),
5686 key_type_to_str(keytype));
5687 c_write_str(ssh, msgbuf);
5689 s->publickey_blob = NULL;
5692 s->publickey_blob = NULL;
5696 * Wait for the result of the last authentication request.
5699 crWaitUntilV(pktin);
5700 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
5704 * Don't show the banner if we're operating in
5705 * non-verbose non-interactive mode. (It's probably
5706 * a script, which means nobody will read the
5707 * banner _anyway_, and moreover the printing of
5708 * the banner will screw up processing on the
5709 * output of (say) plink.)
5711 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
5712 ssh_pkt_getstring(pktin, &banner, &size);
5714 c_write_untrusted(ssh, banner, size);
5716 crWaitUntilV(pktin);
5718 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
5719 logevent("Access granted");
5720 s->we_are_in = TRUE;
5724 if (s->kbd_inter_running &&
5725 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
5727 * This is either a further set-of-prompts packet
5728 * in keyboard-interactive authentication, or it's
5729 * the same one and we came back here with `gotit'
5730 * set. In the former case, we must reset the
5731 * curr_prompt variable.
5735 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
5736 bombout(("Strange packet received during authentication: type %d",
5744 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5745 * we can look at the string in it and know what we can
5746 * helpfully try next.
5748 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
5751 ssh_pkt_getstring(pktin, &methods, &methlen);
5752 s->kbd_inter_running = FALSE;
5753 if (!ssh2_pkt_getbool(pktin)) {
5755 * We have received an unequivocal Access
5756 * Denied. This can translate to a variety of
5759 * - if we'd just tried "none" authentication,
5760 * it's not worth printing anything at all
5762 * - if we'd just tried a public key _offer_,
5763 * the message should be "Server refused our
5764 * key" (or no message at all if the key
5765 * came from Pageant)
5767 * - if we'd just tried anything else, the
5768 * message really should be "Access denied".
5770 * Additionally, if we'd just tried password
5771 * authentication, we should break out of this
5772 * whole loop so as to go back to the username
5773 * prompt (iff we're configured to allow
5774 * username change attempts).
5776 if (s->type == AUTH_TYPE_NONE) {
5778 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5779 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5780 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5781 c_write_str(ssh, "Server refused our key\r\n");
5782 logevent("Server refused public key");
5783 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5784 /* server declined keyboard-interactive; ignore */
5786 c_write_str(ssh, "Access denied\r\n");
5787 logevent("Access denied");
5788 if (s->type == AUTH_TYPE_PASSWORD &&
5789 ssh->cfg.change_username) {
5790 /* XXX perhaps we should allow
5791 * keyboard-interactive to do this too? */
5792 s->we_are_in = FALSE;
5797 c_write_str(ssh, "Further authentication required\r\n");
5798 logevent("Further authentication required");
5802 in_commasep_string("publickey", methods, methlen);
5804 in_commasep_string("password", methods, methlen);
5805 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5806 in_commasep_string("keyboard-interactive", methods, methlen);
5810 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5814 * Most password/passphrase prompts will be
5815 * non-echoing, so we set this to 0 by default.
5816 * Exception is that some keyboard-interactive prompts
5817 * can be echoing, in which case we'll set this to 1.
5821 if (!s->method && s->can_pubkey &&
5822 agent_exists() && !s->tried_agent) {
5824 * Attempt public-key authentication using Pageant.
5829 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5830 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5832 s->tried_agent = TRUE;
5834 logevent("Pageant is running. Requesting keys.");
5836 /* Request the keys held by the agent. */
5837 PUT_32BIT(s->request, 1);
5838 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5839 if (!agent_query(s->request, 5, &r, &s->responselen,
5840 ssh_agent_callback, ssh)) {
5844 bombout(("Unexpected data from server while"
5845 " waiting for agent response"));
5848 } while (pktin || inlen > 0);
5849 r = ssh->agent_response;
5850 s->responselen = ssh->agent_response_len;
5852 s->response = (unsigned char *) r;
5853 if (s->response && s->responselen >= 5 &&
5854 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5855 s->p = s->response + 5;
5856 s->nkeys = GET_32BIT(s->p);
5860 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5863 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5868 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5871 s->pklen = GET_32BIT(s->p);
5873 if (s->publickey_blob &&
5874 s->pklen == s->publickey_bloblen &&
5875 !memcmp(s->p, s->publickey_blob,
5876 s->publickey_bloblen)) {
5877 logevent("This key matches configured key file");
5878 s->tried_pubkey_config = 1;
5880 s->pkblob = (char *)s->p;
5882 s->alglen = GET_32BIT(s->pkblob);
5883 s->alg = s->pkblob + 4;
5884 s->commentlen = GET_32BIT(s->p);
5886 s->commentp = (char *)s->p;
5887 s->p += s->commentlen;
5888 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5889 ssh2_pkt_addstring(s->pktout, s->username);
5890 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5891 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5892 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5893 ssh2_pkt_addstring_start(s->pktout);
5894 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5895 ssh2_pkt_addstring_start(s->pktout);
5896 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5897 ssh2_pkt_send(ssh, s->pktout);
5899 crWaitUntilV(pktin);
5900 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
5901 logevent("Key refused");
5905 if (flags & FLAG_VERBOSE) {
5906 c_write_str(ssh, "Authenticating with "
5908 c_write(ssh, s->commentp, s->commentlen);
5909 c_write_str(ssh, "\" from agent\r\n");
5913 * Server is willing to accept the key.
5914 * Construct a SIGN_REQUEST.
5916 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5917 ssh2_pkt_addstring(s->pktout, s->username);
5918 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5919 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5920 ssh2_pkt_addbool(s->pktout, TRUE);
5921 ssh2_pkt_addstring_start(s->pktout);
5922 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5923 ssh2_pkt_addstring_start(s->pktout);
5924 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5926 s->siglen = s->pktout->length - 5 + 4 + 20;
5927 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5929 s->len = 1; /* message type */
5930 s->len += 4 + s->pklen; /* key blob */
5931 s->len += 4 + s->siglen; /* data to sign */
5932 s->len += 4; /* flags */
5933 s->agentreq = snewn(4 + s->len, char);
5934 PUT_32BIT(s->agentreq, s->len);
5935 s->q = s->agentreq + 4;
5936 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5937 PUT_32BIT(s->q, s->pklen);
5939 memcpy(s->q, s->pkblob, s->pklen);
5941 PUT_32BIT(s->q, s->siglen);
5943 /* Now the data to be signed... */
5944 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5945 PUT_32BIT(s->q, 20);
5948 memcpy(s->q, ssh->v2_session_id, 20);
5950 memcpy(s->q, s->pktout->data + 5,
5951 s->pktout->length - 5);
5952 s->q += s->pktout->length - 5;
5953 /* And finally the (zero) flags word. */
5955 if (!agent_query(s->agentreq, s->len + 4,
5957 ssh_agent_callback, ssh)) {
5961 bombout(("Unexpected data from server"
5962 " while waiting for agent"
5966 } while (pktin || inlen > 0);
5967 vret = ssh->agent_response;
5968 s->retlen = ssh->agent_response_len;
5973 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5974 logevent("Sending Pageant's response");
5975 ssh2_add_sigblob(ssh, s->pktout,
5976 s->pkblob, s->pklen,
5978 GET_32BIT(s->ret + 5));
5979 ssh2_pkt_send(ssh, s->pktout);
5984 ("Pageant failed to answer challenge");
5995 if (!s->method && s->can_pubkey && s->publickey_blob
5996 && !s->tried_pubkey_config) {
5997 unsigned char *pub_blob;
5998 char *algorithm, *comment;
6001 s->tried_pubkey_config = TRUE;
6003 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6004 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6007 * Try the public key supplied in the configuration.
6009 * First, offer the public blob to see if the server is
6010 * willing to accept it.
6013 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6018 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6019 ssh2_pkt_addstring(s->pktout, s->username);
6020 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6021 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6022 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6023 ssh2_pkt_addstring(s->pktout, algorithm);
6024 ssh2_pkt_addstring_start(s->pktout);
6025 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6027 ssh2_pkt_send(ssh, s->pktout);
6028 logevent("Offered public key");
6030 crWaitUntilV(pktin);
6031 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6033 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6034 continue; /* key refused; give up on it */
6037 logevent("Offer of public key accepted");
6039 * Actually attempt a serious authentication using
6042 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6043 sprintf(s->pwprompt,
6044 "Passphrase for key \"%.100s\": ",
6050 if (flags & FLAG_VERBOSE) {
6051 c_write_str(ssh, "Authenticating with public key \"");
6052 c_write_str(ssh, comment);
6053 c_write_str(ssh, "\"\r\n");
6055 s->method = AUTH_PUBLICKEY_FILE;
6059 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6060 s->method = AUTH_KEYBOARD_INTERACTIVE;
6061 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6062 s->tried_keyb_inter = TRUE;
6064 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6065 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6067 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6068 ssh2_pkt_addstring(s->pktout, s->username);
6069 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6070 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6071 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6072 ssh2_pkt_addstring(s->pktout, "");
6073 ssh2_pkt_send(ssh, s->pktout);
6075 crWaitUntilV(pktin);
6076 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6077 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6079 logevent("Keyboard-interactive authentication refused");
6080 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6084 s->kbd_inter_running = TRUE;
6088 if (s->kbd_inter_running) {
6089 s->method = AUTH_KEYBOARD_INTERACTIVE;
6090 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6091 s->tried_keyb_inter = TRUE;
6093 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6094 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6096 if (s->curr_prompt == 0) {
6098 * We've got a fresh USERAUTH_INFO_REQUEST.
6099 * Display header data, and start going through
6102 char *name, *inst, *lang;
6103 int name_len, inst_len, lang_len;
6105 ssh_pkt_getstring(pktin, &name, &name_len);
6106 ssh_pkt_getstring(pktin, &inst, &inst_len);
6107 ssh_pkt_getstring(pktin, &lang, &lang_len);
6109 c_write_untrusted(ssh, name, name_len);
6110 c_write_str(ssh, "\r\n");
6113 c_write_untrusted(ssh, inst, inst_len);
6114 c_write_str(ssh, "\r\n");
6116 s->num_prompts = ssh_pkt_getuint32(pktin);
6120 * If there are prompts remaining in the packet,
6121 * display one and get a response.
6123 if (s->curr_prompt < s->num_prompts) {
6127 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6128 if (prompt_len > 0) {
6129 static const char trunc[] = "<prompt truncated>: ";
6130 static const int prlen = sizeof(s->pwprompt) -
6132 if (prompt_len > prlen) {
6133 memcpy(s->pwprompt, prompt, prlen);
6134 strcpy(s->pwprompt + prlen, trunc);
6136 memcpy(s->pwprompt, prompt, prompt_len);
6137 s->pwprompt[prompt_len] = '\0';
6141 "<server failed to send prompt>: ");
6143 s->echo = ssh2_pkt_getbool(pktin);
6149 if (!s->method && s->can_passwd) {
6150 s->method = AUTH_PASSWORD;
6151 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6152 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6153 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6160 if (!ssh_get_line(s->pwprompt, s->password,
6161 sizeof(s->password), TRUE)) {
6163 * get_line failed to get a password (for
6164 * example because one was supplied on the
6165 * command line which has already failed to
6168 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6169 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6170 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6172 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6173 ssh2_pkt_send_noqueue(ssh, s->pktout);
6174 logevent("Unable to authenticate");
6175 connection_fatal(ssh->frontend,
6176 "Unable to authenticate");
6177 ssh_closing((Plug)ssh, NULL, 0, 0);
6181 int ret; /* need not be saved across crReturn */
6182 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6185 setup_userpass_input(ssh, s->password,
6186 sizeof(s->password), s->echo);
6188 crWaitUntilV(!pktin);
6189 ret = process_userpass_input(ssh, in, inlen);
6193 c_write_str(ssh, "\r\n");
6197 if (s->method == AUTH_PUBLICKEY_FILE) {
6199 * We have our passphrase. Now try the actual authentication.
6201 struct ssh2_userkey *key;
6202 const char *error = NULL;
6204 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6206 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6207 if (key == SSH2_WRONG_PASSPHRASE) {
6208 c_write_str(ssh, "Wrong passphrase\r\n");
6209 s->tried_pubkey_config = FALSE;
6211 c_write_str(ssh, "Unable to load private key (");
6212 c_write_str(ssh, error);
6213 c_write_str(ssh, ")\r\n");
6214 s->tried_pubkey_config = TRUE;
6216 /* Send a spurious AUTH_NONE to return to the top. */
6217 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6218 ssh2_pkt_addstring(s->pktout, s->username);
6219 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6220 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6221 ssh2_pkt_send(ssh, s->pktout);
6222 s->type = AUTH_TYPE_NONE;
6224 unsigned char *pkblob, *sigblob, *sigdata;
6225 int pkblob_len, sigblob_len, sigdata_len;
6229 * We have loaded the private key and the server
6230 * has announced that it's willing to accept it.
6231 * Hallelujah. Generate a signature and send it.
6233 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6234 ssh2_pkt_addstring(s->pktout, s->username);
6235 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6236 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6237 ssh2_pkt_addbool(s->pktout, TRUE);
6238 ssh2_pkt_addstring(s->pktout, key->alg->name);
6239 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6240 ssh2_pkt_addstring_start(s->pktout);
6241 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6244 * The data to be signed is:
6248 * followed by everything so far placed in the
6251 sigdata_len = s->pktout->length - 5 + 4 + 20;
6252 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6254 sigdata = snewn(sigdata_len, unsigned char);
6256 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6257 PUT_32BIT(sigdata+p, 20);
6260 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6261 memcpy(sigdata+p, s->pktout->data + 5,
6262 s->pktout->length - 5);
6263 p += s->pktout->length - 5;
6264 assert(p == sigdata_len);
6265 sigblob = key->alg->sign(key->data, (char *)sigdata,
6266 sigdata_len, &sigblob_len);
6267 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6268 sigblob, sigblob_len);
6273 ssh2_pkt_send(ssh, s->pktout);
6274 s->type = AUTH_TYPE_PUBLICKEY;
6275 key->alg->freekey(key->data);
6277 } else if (s->method == AUTH_PASSWORD) {
6279 * We send the password packet lumped tightly together with
6280 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6281 * string long enough to make the total length of the two
6282 * packets constant. This should ensure that a passive
6283 * listener doing traffic analyis can't work out the length
6286 * For this to work, we need an assumption about the
6287 * maximum length of the password packet. I think 256 is
6288 * pretty conservative. Anyone using a password longer than
6289 * that probably doesn't have much to worry about from
6290 * people who find out how long their password is!
6292 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6293 ssh2_pkt_addstring(s->pktout, s->username);
6294 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6295 ssh2_pkt_addstring(s->pktout, "password");
6296 ssh2_pkt_addbool(s->pktout, FALSE);
6297 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6298 ssh2_pkt_addstring(s->pktout, s->password);
6299 memset(s->password, 0, sizeof(s->password));
6300 end_log_omission(ssh, s->pktout);
6301 ssh2_pkt_defer(ssh, s->pktout);
6303 * We'll include a string that's an exact multiple of the
6304 * cipher block size. If the cipher is NULL for some
6305 * reason, we don't do this trick at all because we gain
6308 if (ssh->cscipher) {
6311 stringlen = (256 - ssh->deferred_len);
6312 stringlen += ssh->cscipher->blksize - 1;
6313 stringlen -= (stringlen % ssh->cscipher->blksize);
6316 * Temporarily disable actual compression,
6317 * so we can guarantee to get this string
6318 * exactly the length we want it. The
6319 * compression-disabling routine should
6320 * return an integer indicating how many
6321 * bytes we should adjust our string length
6325 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6327 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6328 ssh2_pkt_addstring_start(s->pktout);
6329 for (i = 0; i < stringlen; i++) {
6330 char c = (char) random_byte();
6331 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6333 ssh2_pkt_defer(ssh, s->pktout);
6335 ssh_pkt_defersend(ssh);
6336 logevent("Sent password");
6337 s->type = AUTH_TYPE_PASSWORD;
6338 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6339 if (s->curr_prompt == 0) {
6340 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6341 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6343 if (s->need_pw) { /* only add pw if we just got one! */
6344 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6345 ssh2_pkt_addstring(s->pktout, s->password);
6346 memset(s->password, 0, sizeof(s->password));
6347 end_log_omission(ssh, s->pktout);
6350 if (s->curr_prompt >= s->num_prompts) {
6351 ssh2_pkt_send(ssh, s->pktout);
6354 * If there are prompts remaining, we set
6355 * `gotit' so that we won't attempt to get
6356 * another packet. Then we go back round the
6357 * loop and will end up retrieving another
6358 * prompt out of the existing packet. Funky or
6363 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6365 c_write_str(ssh, "No supported authentication methods"
6366 " left to try!\r\n");
6367 logevent("No supported authentications offered."
6369 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6370 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6371 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6372 " methods available");
6373 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6374 ssh2_pkt_send_noqueue(ssh, s->pktout);
6375 ssh_closing((Plug)ssh, NULL, 0, 0);
6379 } while (!s->we_are_in);
6382 * Now we're authenticated for the connection protocol. The
6383 * connection protocol will automatically have started at this
6384 * point; there's no need to send SERVICE_REQUEST.
6387 ssh->channels = newtree234(ssh_channelcmp);
6390 * Set up handlers for some connection protocol messages, so we
6391 * don't have to handle them repeatedly in this coroutine.
6393 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6394 ssh2_msg_channel_window_adjust;
6395 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6396 ssh2_msg_global_request;
6399 * Create the main session channel.
6401 if (!ssh->cfg.ssh_no_shell) {
6402 ssh->mainchan = snew(struct ssh_channel);
6403 ssh->mainchan->ssh = ssh;
6404 ssh->mainchan->localid = alloc_channel_id(ssh);
6405 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6406 ssh2_pkt_addstring(s->pktout, "session");
6407 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6408 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6409 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6410 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6411 ssh2_pkt_send(ssh, s->pktout);
6412 crWaitUntilV(pktin);
6413 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6414 bombout(("Server refused to open a session"));
6416 /* FIXME: error data comes back in FAILURE packet */
6418 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6419 bombout(("Server's channel confirmation cited wrong channel"));
6422 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6423 ssh->mainchan->type = CHAN_MAINSESSION;
6424 ssh->mainchan->closes = 0;
6425 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6426 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6427 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6428 add234(ssh->channels, ssh->mainchan);
6429 update_specials_menu(ssh->frontend);
6430 logevent("Opened channel for session");
6432 ssh->mainchan = NULL;
6435 * Now we have a channel, make dispatch table entries for
6436 * general channel-based messages.
6438 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6439 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6440 ssh2_msg_channel_data;
6441 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6442 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6444 ssh2_msg_channel_open_confirmation;
6445 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6446 ssh2_msg_channel_open_failure;
6447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6448 ssh2_msg_channel_request;
6449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6450 ssh2_msg_channel_open;
6453 * Potentially enable X11 forwarding.
6455 if (ssh->mainchan && ssh->cfg.x11_forward) {
6456 char proto[20], data[64];
6457 logevent("Requesting X11 forwarding");
6458 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6459 data, sizeof(data), ssh->cfg.x11_auth);
6460 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6461 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6462 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6463 ssh2_pkt_addstring(s->pktout, "x11-req");
6464 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6465 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6466 ssh2_pkt_addstring(s->pktout, proto);
6467 ssh2_pkt_addstring(s->pktout, data);
6468 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6469 ssh2_pkt_send(ssh, s->pktout);
6471 crWaitUntilV(pktin);
6473 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6474 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6475 bombout(("Unexpected response to X11 forwarding request:"
6476 " packet type %d", pktin->type));
6479 logevent("X11 forwarding refused");
6481 logevent("X11 forwarding enabled");
6482 ssh->X11_fwd_enabled = TRUE;
6487 * Enable port forwardings.
6492 int sport,dport,sserv,dserv;
6493 char sports[256], dports[256], saddr[256], host[256];
6495 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
6496 /* Add port forwardings. */
6497 ssh->portfwd_strptr = ssh->cfg.portfwd;
6498 while (*ssh->portfwd_strptr) {
6499 type = *ssh->portfwd_strptr++;
6502 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6503 if (*ssh->portfwd_strptr == ':') {
6505 * We've seen a colon in the middle of the
6506 * source port number. This means that
6507 * everything we've seen until now is the
6508 * source _address_, so we'll move it into
6509 * saddr and start sports from the beginning
6512 ssh->portfwd_strptr++;
6514 strcpy(saddr, sports);
6517 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6521 if (*ssh->portfwd_strptr == '\t')
6522 ssh->portfwd_strptr++;
6524 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6525 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6528 if (*ssh->portfwd_strptr == ':')
6529 ssh->portfwd_strptr++;
6531 while (*ssh->portfwd_strptr) {
6532 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6535 ssh->portfwd_strptr++;
6536 dport = atoi(dports);
6540 dport = net_service_lookup(dports);
6542 logeventf(ssh, "Service lookup failed for destination"
6543 " port \"%s\"", dports);
6547 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
6549 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
6551 sport = atoi(sports);
6555 sport = net_service_lookup(sports);
6557 logeventf(ssh, "Service lookup failed for source"
6558 " port \"%s\"", sports);
6561 if (sport && dport) {
6562 /* Set up a description of the source port. */
6563 static char *sportdesc;
6564 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
6565 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6566 (int)(*saddr?1:0), ":",
6567 (int)(sserv ? strlen(sports) : 0), sports,
6568 sserv, "(", sport, sserv, ")");
6570 /* Verbose description of the destination port */
6571 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6573 (int)(dserv ? strlen(dports) : 0), dports,
6574 dserv, "(", dport, dserv, ")");
6575 const char *err = pfd_addforward(host, dport,
6576 *saddr ? saddr : NULL,
6577 sport, ssh, &ssh->cfg);
6579 logeventf(ssh, "Local port %s forward to %s"
6580 " failed: %s", sportdesc, dportdesc, err);
6582 logeventf(ssh, "Local port %s forwarding to %s",
6583 sportdesc, dportdesc);
6586 } else if (type == 'D') {
6587 const char *err = pfd_addforward(NULL, -1,
6588 *saddr ? saddr : NULL,
6589 sport, ssh, &ssh->cfg);
6591 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6592 " setup failed: %s", sportdesc, err);
6594 logeventf(ssh, "Local port %s doing SOCKS"
6595 " dynamic forwarding", sportdesc);
6598 struct ssh_rportfwd *pf;
6599 pf = snew(struct ssh_rportfwd);
6600 strcpy(pf->dhost, host);
6603 if (add234(ssh->rportfwds, pf) != pf) {
6604 logeventf(ssh, "Duplicate remote port forwarding"
6605 " to %s:%d", host, dport);
6608 logeventf(ssh, "Requesting remote port %s"
6609 " forward to %s:%.*s%.*s%d%.*s",
6612 (int)(dserv ? strlen(dports) : 0), dports,
6613 dserv, "(", dport, dserv, ")");
6614 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6615 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6616 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
6618 ssh2_pkt_addstring(s->pktout, saddr);
6619 } else if (ssh->cfg.rport_acceptall) {
6620 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
6622 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
6624 ssh2_pkt_adduint32(s->pktout, sport);
6625 ssh2_pkt_send(ssh, s->pktout);
6627 crWaitUntilV(pktin);
6629 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6630 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6631 bombout(("Unexpected response to port "
6632 "forwarding request: packet type %d",
6636 logevent("Server refused this port forwarding");
6638 logevent("Remote port forwarding enabled");
6648 * Potentially enable agent forwarding.
6650 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6651 logevent("Requesting OpenSSH-style agent forwarding");
6652 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6653 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6654 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6655 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6656 ssh2_pkt_send(ssh, s->pktout);
6658 crWaitUntilV(pktin);
6660 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6661 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6662 bombout(("Unexpected response to agent forwarding request:"
6663 " packet type %d", pktin->type));
6666 logevent("Agent forwarding refused");
6668 logevent("Agent forwarding enabled");
6669 ssh->agentfwd_enabled = TRUE;
6674 * Now allocate a pty for the session.
6676 if (ssh->mainchan && !ssh->cfg.nopty) {
6677 /* Unpick the terminal-speed string. */
6678 /* XXX perhaps we should allow no speeds to be sent. */
6679 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6680 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6681 /* Build the pty request. */
6682 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6683 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6684 ssh2_pkt_addstring(s->pktout, "pty-req");
6685 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6686 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6687 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6688 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6689 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6690 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6691 ssh2_pkt_addstring_start(s->pktout);
6692 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6693 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6694 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6695 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6696 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6697 ssh2_pkt_send(ssh, s->pktout);
6698 ssh->state = SSH_STATE_INTERMED;
6700 crWaitUntilV(pktin);
6702 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6703 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6704 bombout(("Unexpected response to pty request:"
6705 " packet type %d", pktin->type));
6708 c_write_str(ssh, "Server refused to allocate pty\r\n");
6709 ssh->editing = ssh->echoing = 1;
6711 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6712 ssh->ospeed, ssh->ispeed);
6715 ssh->editing = ssh->echoing = 1;
6719 * Send environment variables.
6721 * Simplest thing here is to send all the requests at once, and
6722 * then wait for a whole bunch of successes or failures.
6724 if (ssh->mainchan && *ssh->cfg.environmt) {
6725 char *e = ssh->cfg.environmt;
6726 char *var, *varend, *val;
6732 while (*e && *e != '\t') e++;
6734 if (*e == '\t') e++;
6739 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6740 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6741 ssh2_pkt_addstring(s->pktout, "env");
6742 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6743 ssh2_pkt_addstring_start(s->pktout);
6744 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6745 ssh2_pkt_addstring(s->pktout, val);
6746 ssh2_pkt_send(ssh, s->pktout);
6751 logeventf(ssh, "Sent %d environment variables", s->num_env);
6754 s->env_left = s->num_env;
6756 while (s->env_left > 0) {
6757 crWaitUntilV(pktin);
6759 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6760 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6761 bombout(("Unexpected response to environment request:"
6762 " packet type %d", pktin->type));
6772 if (s->env_ok == s->num_env) {
6773 logevent("All environment variables successfully set");
6774 } else if (s->env_ok == 0) {
6775 logevent("All environment variables refused");
6776 c_write_str(ssh, "Server refused to set environment variables\r\n");
6778 logeventf(ssh, "%d environment variables refused",
6779 s->num_env - s->env_ok);
6780 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6785 * Start a shell or a remote command. We may have to attempt
6786 * this twice if the config data has provided a second choice
6789 if (ssh->mainchan) while (1) {
6793 if (ssh->fallback_cmd) {
6794 subsys = ssh->cfg.ssh_subsys2;
6795 cmd = ssh->cfg.remote_cmd_ptr2;
6797 subsys = ssh->cfg.ssh_subsys;
6798 cmd = ssh->cfg.remote_cmd_ptr;
6801 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6802 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6804 ssh2_pkt_addstring(s->pktout, "subsystem");
6805 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6806 ssh2_pkt_addstring(s->pktout, cmd);
6808 ssh2_pkt_addstring(s->pktout, "exec");
6809 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6810 ssh2_pkt_addstring(s->pktout, cmd);
6812 ssh2_pkt_addstring(s->pktout, "shell");
6813 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6815 ssh2_pkt_send(ssh, s->pktout);
6817 crWaitUntilV(pktin);
6819 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6820 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6821 bombout(("Unexpected response to shell/command request:"
6822 " packet type %d", pktin->type));
6826 * We failed to start the command. If this is the
6827 * fallback command, we really are finished; if it's
6828 * not, and if the fallback command exists, try falling
6829 * back to it before complaining.
6831 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6832 logevent("Primary command failed; attempting fallback");
6833 ssh->fallback_cmd = TRUE;
6836 bombout(("Server refused to start a shell/command"));
6839 logevent("Started a shell/command");
6844 ssh->state = SSH_STATE_SESSION;
6845 if (ssh->size_needed)
6846 ssh_size(ssh, ssh->term_width, ssh->term_height);
6847 if (ssh->eof_needed)
6848 ssh_special(ssh, TS_EOF);
6854 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6859 s->try_send = FALSE;
6863 * _All_ the connection-layer packets we expect to
6864 * receive are now handled by the dispatch table.
6865 * Anything that reaches here must be bogus.
6868 bombout(("Strange packet received: type %d", pktin->type));
6870 } else if (ssh->mainchan) {
6872 * We have spare data. Add it to the channel buffer.
6874 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6879 struct ssh_channel *c;
6881 * Try to send data on all channels if we can.
6883 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6886 continue; /* don't send on closing channels */
6887 bufsize = ssh2_try_send(c);
6890 case CHAN_MAINSESSION:
6891 /* stdin need not receive an unthrottle
6892 * notification since it will be polled */
6895 x11_unthrottle(c->u.x11.s);
6898 /* agent sockets are request/response and need no
6899 * buffer management */
6902 pfd_unthrottle(c->u.pfd.s);
6914 * Handlers for SSH2 messages that might arrive at any moment.
6916 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6918 /* log reason code in disconnect message */
6920 int nowlen, reason, msglen;
6922 reason = ssh_pkt_getuint32(pktin);
6923 ssh_pkt_getstring(pktin, &msg, &msglen);
6925 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6926 buf = dupprintf("Received disconnect message (%s)",
6927 ssh2_disconnect_reasons[reason]);
6929 buf = dupprintf("Received disconnect message (unknown"
6930 " type %d)", reason);
6934 buf = dupprintf("Disconnection message text: %n%.*s",
6935 &nowlen, msglen, msg);
6937 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6939 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6940 ssh2_disconnect_reasons[reason] : "unknown",
6945 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6947 /* log the debug message */
6952 /* XXX maybe we should actually take notice of this */
6953 always_display = ssh2_pkt_getbool(pktin);
6954 ssh_pkt_getstring(pktin, &msg, &msglen);
6956 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6961 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6963 struct Packet *pktout;
6964 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6965 ssh2_pkt_adduint32(pktout, pktin->sequence);
6967 * UNIMPLEMENTED messages MUST appear in the same order as the
6968 * messages they respond to. Hence, never queue them.
6970 ssh2_pkt_send_noqueue(ssh, pktout);
6974 * Handle the top-level SSH2 protocol.
6976 static void ssh2_protocol_setup(Ssh ssh)
6981 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6983 for (i = 0; i < 256; i++)
6984 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6987 * Any message we actually understand, we set to NULL so that
6988 * the coroutines will get it.
6990 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6991 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6992 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6993 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6994 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6995 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6996 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6997 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
6998 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
6999 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7000 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7001 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7002 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7003 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7004 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7005 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7006 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7007 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7008 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7009 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7010 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7011 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7012 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7013 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7014 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7025 * These special message types we install handlers for.
7027 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7028 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7029 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7032 static void ssh2_timer(void *ctx, long now)
7036 if (!ssh->kex_in_progress &&
7037 now - ssh->next_rekey >= 0) {
7038 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7043 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7044 struct Packet *pktin)
7046 if (ssh->state == SSH_STATE_CLOSED)
7050 ssh->incoming_data_size += pktin->encrypted_len;
7051 if (!ssh->kex_in_progress &&
7052 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7053 do_ssh2_transport(ssh, "Initiating key re-exchange "
7054 "(too much data received)", -1, NULL);
7057 if (pktin && ssh->packet_dispatch[pktin->type]) {
7058 ssh->packet_dispatch[pktin->type](ssh, pktin);
7062 if (!ssh->protocol_initial_phase_done ||
7063 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7064 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7065 !ssh->protocol_initial_phase_done) {
7066 ssh->protocol_initial_phase_done = TRUE;
7068 * Allow authconn to initialise itself.
7070 do_ssh2_authconn(ssh, NULL, 0, NULL);
7073 do_ssh2_authconn(ssh, in, inlen, pktin);
7078 * Called to set up the connection.
7080 * Returns an error message, or NULL on success.
7082 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7084 char *host, int port, char **realhost, int nodelay,
7090 ssh = snew(struct ssh_tag);
7091 ssh->cfg = *cfg; /* STRUCTURE COPY */
7092 ssh->version = 0; /* when not ready yet */
7095 ssh->v1_cipher_ctx = NULL;
7096 ssh->crcda_ctx = NULL;
7097 ssh->cscipher = NULL;
7098 ssh->cs_cipher_ctx = NULL;
7099 ssh->sccipher = NULL;
7100 ssh->sc_cipher_ctx = NULL;
7102 ssh->cs_mac_ctx = NULL;
7104 ssh->sc_mac_ctx = NULL;
7106 ssh->cs_comp_ctx = NULL;
7108 ssh->sc_comp_ctx = NULL;
7110 ssh->kex_ctx = NULL;
7111 ssh->hostkey = NULL;
7113 ssh->state = SSH_STATE_PREPACKET;
7114 ssh->size_needed = FALSE;
7115 ssh->eof_needed = FALSE;
7118 ssh->deferred_send_data = NULL;
7119 ssh->deferred_len = 0;
7120 ssh->deferred_size = 0;
7121 ssh->fallback_cmd = 0;
7123 ssh->x11auth = NULL;
7124 ssh->v1_compressing = FALSE;
7125 ssh->v2_outgoing_sequence = 0;
7126 ssh->ssh1_rdpkt_crstate = 0;
7127 ssh->ssh2_rdpkt_crstate = 0;
7128 ssh->do_ssh_init_crstate = 0;
7129 ssh->ssh_gotdata_crstate = 0;
7130 ssh->do_ssh1_connection_crstate = 0;
7131 ssh->do_ssh1_login_crstate = 0;
7132 ssh->do_ssh2_transport_crstate = 0;
7133 ssh->do_ssh2_authconn_crstate = 0;
7134 ssh->do_ssh_init_state = NULL;
7135 ssh->do_ssh1_login_state = NULL;
7136 ssh->do_ssh2_transport_state = NULL;
7137 ssh->do_ssh2_authconn_state = NULL;
7138 ssh->mainchan = NULL;
7139 ssh->throttled_all = 0;
7140 ssh->v1_stdout_throttling = 0;
7142 ssh->queuelen = ssh->queuesize = 0;
7143 ssh->queueing = FALSE;
7145 *backend_handle = ssh;
7148 if (crypto_startup() == 0)
7149 return "Microsoft high encryption pack not installed!";
7152 ssh->frontend = frontend_handle;
7153 ssh->term_width = ssh->cfg.width;
7154 ssh->term_height = ssh->cfg.height;
7156 ssh->channels = NULL;
7157 ssh->rportfwds = NULL;
7162 ssh->v1_throttle_count = 0;
7163 ssh->overall_bufsize = 0;
7164 ssh->fallback_cmd = 0;
7166 ssh->protocol = NULL;
7168 ssh->protocol_initial_phase_done = FALSE;
7172 ssh->incoming_data_size = ssh->outgoing_data_size =
7173 ssh->deferred_data_size = 0L;
7174 ssh->kex_in_progress = FALSE;
7176 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7185 static void ssh_free(void *handle)
7187 Ssh ssh = (Ssh) handle;
7188 struct ssh_channel *c;
7189 struct ssh_rportfwd *pf;
7191 if (ssh->v1_cipher_ctx)
7192 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7193 if (ssh->cs_cipher_ctx)
7194 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7195 if (ssh->sc_cipher_ctx)
7196 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7197 if (ssh->cs_mac_ctx)
7198 ssh->csmac->free_context(ssh->cs_mac_ctx);
7199 if (ssh->sc_mac_ctx)
7200 ssh->scmac->free_context(ssh->sc_mac_ctx);
7201 if (ssh->cs_comp_ctx) {
7203 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7205 zlib_compress_cleanup(ssh->cs_comp_ctx);
7207 if (ssh->sc_comp_ctx) {
7209 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7211 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7214 dh_cleanup(ssh->kex_ctx);
7215 sfree(ssh->savedhost);
7217 while (ssh->queuelen-- > 0)
7218 ssh_free_packet(ssh->queue[ssh->queuelen]);
7221 if (ssh->channels) {
7222 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7225 if (c->u.x11.s != NULL)
7226 x11_close(c->u.x11.s);
7229 if (c->u.pfd.s != NULL)
7230 pfd_close(c->u.pfd.s);
7235 freetree234(ssh->channels);
7238 if (ssh->rportfwds) {
7239 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7241 freetree234(ssh->rportfwds);
7243 sfree(ssh->deferred_send_data);
7245 x11_free_auth(ssh->x11auth);
7246 sfree(ssh->do_ssh_init_state);
7247 sfree(ssh->do_ssh1_login_state);
7248 sfree(ssh->do_ssh2_transport_state);
7249 sfree(ssh->do_ssh2_authconn_state);
7250 if (ssh->crcda_ctx) {
7251 crcda_free_context(ssh->crcda_ctx);
7252 ssh->crcda_ctx = NULL;
7256 expire_timer_context(ssh);
7259 pinger_free(ssh->pinger);
7265 * Reconfigure the SSH backend.
7267 * Currently, this function does nothing very useful. In future,
7268 * however, we could do some handy things with it. For example, we
7269 * could make the port forwarding configurer active in the Change
7270 * Settings box, and this routine could close down existing
7271 * forwardings and open up new ones in response to changes.
7273 static void ssh_reconfig(void *handle, Config *cfg)
7275 Ssh ssh = (Ssh) handle;
7276 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7277 ssh->cfg = *cfg; /* STRUCTURE COPY */
7281 * Called to send data down the Telnet connection.
7283 static int ssh_send(void *handle, char *buf, int len)
7285 Ssh ssh = (Ssh) handle;
7287 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7290 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7292 return ssh_sendbuffer(ssh);
7296 * Called to query the current amount of buffered stdin data.
7298 static int ssh_sendbuffer(void *handle)
7300 Ssh ssh = (Ssh) handle;
7303 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7307 * If the SSH socket itself has backed up, add the total backup
7308 * size on that to any individual buffer on the stdin channel.
7311 if (ssh->throttled_all)
7312 override_value = ssh->overall_bufsize;
7314 if (ssh->version == 1) {
7315 return override_value;
7316 } else if (ssh->version == 2) {
7317 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7318 return override_value;
7320 return (override_value +
7321 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7328 * Called to set the size of the window from SSH's POV.
7330 static void ssh_size(void *handle, int width, int height)
7332 Ssh ssh = (Ssh) handle;
7333 struct Packet *pktout;
7335 ssh->term_width = width;
7336 ssh->term_height = height;
7338 switch (ssh->state) {
7339 case SSH_STATE_BEFORE_SIZE:
7340 case SSH_STATE_PREPACKET:
7341 case SSH_STATE_CLOSED:
7342 break; /* do nothing */
7343 case SSH_STATE_INTERMED:
7344 ssh->size_needed = TRUE; /* buffer for later */
7346 case SSH_STATE_SESSION:
7347 if (!ssh->cfg.nopty) {
7348 if (ssh->version == 1) {
7349 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7350 PKT_INT, ssh->term_height,
7351 PKT_INT, ssh->term_width,
7352 PKT_INT, 0, PKT_INT, 0, PKT_END);
7353 } else if (ssh->mainchan) {
7354 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7355 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7356 ssh2_pkt_addstring(pktout, "window-change");
7357 ssh2_pkt_addbool(pktout, 0);
7358 ssh2_pkt_adduint32(pktout, ssh->term_width);
7359 ssh2_pkt_adduint32(pktout, ssh->term_height);
7360 ssh2_pkt_adduint32(pktout, 0);
7361 ssh2_pkt_adduint32(pktout, 0);
7362 ssh2_pkt_send(ssh, pktout);
7370 * Return a list of the special codes that make sense in this
7373 static const struct telnet_special *ssh_get_specials(void *handle)
7375 static const struct telnet_special ignore_special[] = {
7376 {"IGNORE message", TS_NOP},
7377 {"Repeat key exchange", TS_REKEY},
7379 static const struct telnet_special ssh2_session_specials[] = {
7382 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7383 * They include all the ISO C signals, but are a subset of the POSIX
7384 * required signals. */
7385 {"SIGINT (Interrupt)", TS_SIGINT},
7386 {"SIGTERM (Terminate)", TS_SIGTERM},
7387 {"SIGKILL (Kill)", TS_SIGKILL},
7388 {"SIGQUIT (Quit)", TS_SIGQUIT},
7389 {"SIGHUP (Hangup)", TS_SIGHUP},
7390 {"More signals", TS_SUBMENU},
7391 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7392 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7393 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7394 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7397 static const struct telnet_special specials_end[] = {
7400 static struct telnet_special ssh_specials[lenof(ignore_special) +
7401 lenof(ssh2_session_specials) +
7402 lenof(specials_end)];
7403 Ssh ssh = (Ssh) handle;
7405 #define ADD_SPECIALS(name) \
7407 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7408 memcpy(&ssh_specials[i], name, sizeof name); \
7412 if (ssh->version == 1) {
7413 /* Don't bother offering IGNORE if we've decided the remote
7414 * won't cope with it, since we wouldn't bother sending it if
7416 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7417 ADD_SPECIALS(ignore_special);
7418 } else if (ssh->version == 2) {
7419 ADD_SPECIALS(ignore_special);
7421 ADD_SPECIALS(ssh2_session_specials);
7422 } /* else we're not ready yet */
7425 ADD_SPECIALS(specials_end);
7426 return ssh_specials;
7434 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7435 * can send an EOF and collect resulting output (e.g. `plink
7438 static void ssh_special(void *handle, Telnet_Special code)
7440 Ssh ssh = (Ssh) handle;
7441 struct Packet *pktout;
7443 if (code == TS_EOF) {
7444 if (ssh->state != SSH_STATE_SESSION) {
7446 * Buffer the EOF in case we are pre-SESSION, so we can
7447 * send it as soon as we reach SESSION.
7450 ssh->eof_needed = TRUE;
7453 if (ssh->version == 1) {
7454 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7455 } else if (ssh->mainchan) {
7456 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7457 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7458 ssh2_pkt_send(ssh, pktout);
7460 logevent("Sent EOF message");
7461 } else if (code == TS_PING || code == TS_NOP) {
7462 if (ssh->state == SSH_STATE_CLOSED
7463 || ssh->state == SSH_STATE_PREPACKET) return;
7464 if (ssh->version == 1) {
7465 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7466 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7468 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7469 ssh2_pkt_addstring_start(pktout);
7470 ssh2_pkt_send_noqueue(ssh, pktout);
7472 } else if (code == TS_REKEY) {
7473 if (!ssh->kex_in_progress && ssh->version == 2) {
7474 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7475 " user request", -1, NULL);
7477 } else if (code == TS_BRK) {
7478 if (ssh->state == SSH_STATE_CLOSED
7479 || ssh->state == SSH_STATE_PREPACKET) return;
7480 if (ssh->version == 1) {
7481 logevent("Unable to send BREAK signal in SSH1");
7482 } else if (ssh->mainchan) {
7483 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7484 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7485 ssh2_pkt_addstring(pktout, "break");
7486 ssh2_pkt_addbool(pktout, 0);
7487 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7488 ssh2_pkt_send(ssh, pktout);
7491 /* Is is a POSIX signal? */
7492 char *signame = NULL;
7493 if (code == TS_SIGABRT) signame = "ABRT";
7494 if (code == TS_SIGALRM) signame = "ALRM";
7495 if (code == TS_SIGFPE) signame = "FPE";
7496 if (code == TS_SIGHUP) signame = "HUP";
7497 if (code == TS_SIGILL) signame = "ILL";
7498 if (code == TS_SIGINT) signame = "INT";
7499 if (code == TS_SIGKILL) signame = "KILL";
7500 if (code == TS_SIGPIPE) signame = "PIPE";
7501 if (code == TS_SIGQUIT) signame = "QUIT";
7502 if (code == TS_SIGSEGV) signame = "SEGV";
7503 if (code == TS_SIGTERM) signame = "TERM";
7504 if (code == TS_SIGUSR1) signame = "USR1";
7505 if (code == TS_SIGUSR2) signame = "USR2";
7506 /* The SSH-2 protocol does in principle support arbitrary named
7507 * signals, including signame@domain, but we don't support those. */
7509 /* It's a signal. */
7510 if (ssh->version == 2 && ssh->mainchan) {
7511 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7512 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7513 ssh2_pkt_addstring(pktout, "signal");
7514 ssh2_pkt_addbool(pktout, 0);
7515 ssh2_pkt_addstring(pktout, signame);
7516 ssh2_pkt_send(ssh, pktout);
7517 logeventf(ssh, "Sent signal SIG%s", signame);
7520 /* Never heard of it. Do nothing */
7525 void *new_sock_channel(void *handle, Socket s)
7527 Ssh ssh = (Ssh) handle;
7528 struct ssh_channel *c;
7529 c = snew(struct ssh_channel);
7533 c->remoteid = -1; /* to be set when open confirmed */
7534 c->localid = alloc_channel_id(ssh);
7536 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7538 bufchain_init(&c->v.v2.outbuffer);
7539 add234(ssh->channels, c);
7545 * This is called when stdout/stderr (the entity to which
7546 * from_backend sends data) manages to clear some backlog.
7548 static void ssh_unthrottle(void *handle, int bufsize)
7550 Ssh ssh = (Ssh) handle;
7551 if (ssh->version == 1) {
7552 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7553 ssh->v1_stdout_throttling = 0;
7554 ssh1_throttle(ssh, -1);
7557 if (ssh->mainchan && ssh->mainchan->closes == 0)
7558 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7562 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7564 struct ssh_channel *c = (struct ssh_channel *)channel;
7566 struct Packet *pktout;
7568 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7570 if (ssh->version == 1) {
7571 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7572 PKT_INT, c->localid,
7575 //PKT_STR, <org:orgport>,
7578 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7579 ssh2_pkt_addstring(pktout, "direct-tcpip");
7580 ssh2_pkt_adduint32(pktout, c->localid);
7581 c->v.v2.locwindow = OUR_V2_WINSIZE;
7582 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7583 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7584 ssh2_pkt_addstring(pktout, hostname);
7585 ssh2_pkt_adduint32(pktout, port);
7587 * We make up values for the originator data; partly it's
7588 * too much hassle to keep track, and partly I'm not
7589 * convinced the server should be told details like that
7590 * about my local network configuration.
7592 ssh2_pkt_addstring(pktout, "client-side-connection");
7593 ssh2_pkt_adduint32(pktout, 0);
7594 ssh2_pkt_send(ssh, pktout);
7598 static Socket ssh_socket(void *handle)
7600 Ssh ssh = (Ssh) handle;
7604 static int ssh_sendok(void *handle)
7606 Ssh ssh = (Ssh) handle;
7607 return ssh->send_ok;
7610 static int ssh_ldisc(void *handle, int option)
7612 Ssh ssh = (Ssh) handle;
7613 if (option == LD_ECHO)
7614 return ssh->echoing;
7615 if (option == LD_EDIT)
7616 return ssh->editing;
7620 static void ssh_provide_ldisc(void *handle, void *ldisc)
7622 Ssh ssh = (Ssh) handle;
7626 static void ssh_provide_logctx(void *handle, void *logctx)
7628 Ssh ssh = (Ssh) handle;
7629 ssh->logctx = logctx;
7632 static int ssh_return_exitcode(void *handle)
7634 Ssh ssh = (Ssh) handle;
7638 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7642 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7643 * that fails. This variable is the means by which scp.c can reach
7644 * into the SSH code and find out which one it got.
7646 extern int ssh_fallback_cmd(void *handle)
7648 Ssh ssh = (Ssh) handle;
7649 return ssh->fallback_cmd;
7652 Backend ssh_backend = {
7662 ssh_return_exitcode,