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, "\015\012")] = '\0';/* remove EOL chars */
2155 vlog = snewn(20 + s->vslen, char);
2156 sprintf(vlog, "Server version: %s", s->vstring);
2160 ssh_detect_bugs(ssh, s->vstring);
2163 * Decide which SSH protocol version to support.
2166 /* Anything strictly below "2.0" means protocol 1 is supported. */
2167 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2168 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2169 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2171 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2172 bombout(("SSH protocol version 1 required by user but not provided by server"));
2175 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2176 bombout(("SSH protocol version 2 required by user but not provided by server"));
2183 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2185 * Construct a v2 version string.
2187 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2191 * Construct a v1 version string.
2193 verstring = dupprintf("SSH-%s-%s\012",
2194 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2195 s->version : "1.5"),
2200 ssh_fix_verstring(verstring);
2202 if (ssh->version == 2) {
2204 * Hash our version string and their version string.
2206 SHA_Init(&ssh->exhashbase);
2207 sha_string(&ssh->exhashbase, verstring,
2208 strcspn(verstring, "\015\012"));
2209 sha_string(&ssh->exhashbase, s->vstring,
2210 strcspn(s->vstring, "\015\012"));
2213 * Initialise SSHv2 protocol.
2215 ssh->protocol = ssh2_protocol;
2216 ssh2_protocol_setup(ssh);
2217 ssh->s_rdpkt = ssh2_rdpkt;
2220 * Initialise SSHv1 protocol.
2222 ssh->protocol = ssh1_protocol;
2223 ssh1_protocol_setup(ssh);
2224 ssh->s_rdpkt = ssh1_rdpkt;
2226 logeventf(ssh, "We claim version: %.*s",
2227 strcspn(verstring, "\015\012"), verstring);
2228 sk_write(ssh->s, verstring, strlen(verstring));
2232 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2234 update_specials_menu(ssh->frontend);
2235 ssh->state = SSH_STATE_BEFORE_SIZE;
2236 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2243 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2245 crBegin(ssh->ssh_gotdata_crstate);
2248 * To begin with, feed the characters one by one to the
2249 * protocol initialisation / selection function do_ssh_init().
2250 * When that returns 0, we're done with the initial greeting
2251 * exchange and can move on to packet discipline.
2254 int ret; /* need not be kept across crReturn */
2256 crReturnV; /* more data please */
2257 ret = do_ssh_init(ssh, *data);
2265 * We emerge from that loop when the initial negotiation is
2266 * over and we have selected an s_rdpkt function. Now pass
2267 * everything to s_rdpkt, and then pass the resulting packets
2268 * to the proper protocol handler.
2273 while (datalen > 0) {
2274 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2276 ssh->protocol(ssh, NULL, 0, pktin);
2277 ssh_free_packet(pktin);
2279 if (ssh->state == SSH_STATE_CLOSED)
2287 static void ssh_do_close(Ssh ssh)
2290 struct ssh_channel *c;
2292 ssh->state = SSH_STATE_CLOSED;
2296 notify_remote_exit(ssh->frontend);
2299 * Now we must shut down any port and X forwardings going
2300 * through this connection.
2302 if (ssh->channels) {
2303 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2306 x11_close(c->u.x11.s);
2309 pfd_close(c->u.pfd.s);
2312 del234(ssh->channels, c);
2313 if (ssh->version == 2)
2314 bufchain_clear(&c->v.v2.outbuffer);
2320 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2323 Ssh ssh = (Ssh) plug;
2326 /* A socket error has occurred. */
2327 logevent(error_msg);
2328 connection_fatal(ssh->frontend, "%s", error_msg);
2330 /* Otherwise, the remote side closed the connection normally. */
2335 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2337 Ssh ssh = (Ssh) plug;
2338 ssh_gotdata(ssh, (unsigned char *)data, len);
2339 if (ssh->state == SSH_STATE_CLOSED) {
2346 static void ssh_sent(Plug plug, int bufsize)
2348 Ssh ssh = (Ssh) plug;
2350 * If the send backlog on the SSH socket itself clears, we
2351 * should unthrottle the whole world if it was throttled.
2353 if (bufsize < SSH_MAX_BACKLOG)
2354 ssh_throttle_all(ssh, 0, bufsize);
2358 * Connect to specified host and port.
2359 * Returns an error message, or NULL on success.
2360 * Also places the canonical host name into `realhost'. It must be
2361 * freed by the caller.
2363 static const char *connect_to_host(Ssh ssh, char *host, int port,
2364 char **realhost, int nodelay, int keepalive)
2366 static const struct plug_function_table fn_table = {
2376 ssh->savedhost = snewn(1 + strlen(host), char);
2377 if (!ssh->savedhost)
2378 fatalbox("Out of memory");
2379 strcpy(ssh->savedhost, host);
2382 port = 22; /* default ssh port */
2383 ssh->savedport = port;
2388 logeventf(ssh, "Looking up host \"%s\"", host);
2389 addr = name_lookup(host, port, realhost, &ssh->cfg);
2390 if ((err = sk_addr_error(addr)) != NULL) {
2400 sk_getaddr(addr, addrbuf, 100);
2401 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2403 ssh->fn = &fn_table;
2404 ssh->s = new_connection(addr, *realhost, port,
2405 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2406 if ((err = sk_socket_error(ssh->s)) != NULL) {
2408 notify_remote_exit(ssh->frontend);
2416 * Throttle or unthrottle the SSH connection.
2418 static void ssh1_throttle(Ssh ssh, int adjust)
2420 int old_count = ssh->v1_throttle_count;
2421 ssh->v1_throttle_count += adjust;
2422 assert(ssh->v1_throttle_count >= 0);
2423 if (ssh->v1_throttle_count && !old_count) {
2424 sk_set_frozen(ssh->s, 1);
2425 } else if (!ssh->v1_throttle_count && old_count) {
2426 sk_set_frozen(ssh->s, 0);
2431 * Throttle or unthrottle _all_ local data streams (for when sends
2432 * on the SSH connection itself back up).
2434 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2437 struct ssh_channel *c;
2439 if (enable == ssh->throttled_all)
2441 ssh->throttled_all = enable;
2442 ssh->overall_bufsize = bufsize;
2445 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2447 case CHAN_MAINSESSION:
2449 * This is treated separately, outside the switch.
2453 x11_override_throttle(c->u.x11.s, enable);
2456 /* Agent channels require no buffer management. */
2459 pfd_override_throttle(c->u.pfd.s, enable);
2466 * Username and password input, abstracted off into routines
2467 * reusable in several places - even between SSH1 and SSH2.
2470 /* Set up a username or password input loop on a given buffer. */
2471 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2473 ssh->userpass_input_buffer = buffer;
2474 ssh->userpass_input_buflen = buflen;
2475 ssh->userpass_input_bufpos = 0;
2476 ssh->userpass_input_echo = echo;
2480 * Process some terminal data in the course of username/password
2481 * input. Returns >0 for success (line of input returned in
2482 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2483 * for inconclusive (keep waiting for more input please).
2485 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2490 switch (c = *in++) {
2493 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2494 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2499 if (ssh->userpass_input_bufpos > 0) {
2500 if (ssh->userpass_input_echo)
2501 c_write_str(ssh, "\b \b");
2502 ssh->userpass_input_bufpos--;
2507 while (ssh->userpass_input_bufpos > 0) {
2508 if (ssh->userpass_input_echo)
2509 c_write_str(ssh, "\b \b");
2510 ssh->userpass_input_bufpos--;
2519 * This simplistic check for printability is disabled
2520 * when we're doing password input, because some people
2521 * have control characters in their passwords.o
2523 if ((!ssh->userpass_input_echo ||
2524 (c >= ' ' && c <= '~') ||
2525 ((unsigned char) c >= 160))
2526 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2527 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2528 if (ssh->userpass_input_echo)
2529 c_write(ssh, &c, 1);
2537 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2539 Ssh ssh = (Ssh) sshv;
2541 ssh->agent_response = reply;
2542 ssh->agent_response_len = replylen;
2544 if (ssh->version == 1)
2545 do_ssh1_login(ssh, NULL, -1, NULL);
2547 do_ssh2_authconn(ssh, NULL, -1, NULL);
2550 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2552 struct ssh_channel *c = (struct ssh_channel *)cv;
2554 void *sentreply = reply;
2557 /* Fake SSH_AGENT_FAILURE. */
2558 sentreply = "\0\0\0\1\5";
2561 if (ssh->version == 2) {
2562 ssh2_add_channel_data(c, sentreply, replylen);
2565 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2566 PKT_INT, c->remoteid,
2569 PKT_DATA, sentreply, replylen,
2578 * Handle the key exchange and user authentication phases.
2580 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2581 struct Packet *pktin)
2584 unsigned char cookie[8], *ptr;
2585 struct RSAKey servkey, hostkey;
2586 struct MD5Context md5c;
2587 struct do_ssh1_login_state {
2589 unsigned char *rsabuf, *keystr1, *keystr2;
2590 unsigned long supported_ciphers_mask, supported_auths_mask;
2591 int tried_publickey, tried_agent;
2592 int tis_auth_refused, ccard_auth_refused;
2593 unsigned char session_id[16];
2596 void *publickey_blob;
2597 int publickey_bloblen;
2603 unsigned char request[5], *response, *p;
2612 crState(do_ssh1_login_state);
2614 crBegin(ssh->do_ssh1_login_crstate);
2619 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2620 bombout(("Public key packet not received"));
2624 logevent("Received public keys");
2626 ptr = ssh_pkt_getdata(pktin, 8);
2628 bombout(("SSH1 public key packet stopped before random cookie"));
2631 memcpy(cookie, ptr, 8);
2633 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2634 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2635 bombout(("Failed to read SSH1 public keys from public key packet"));
2640 * Log the host key fingerprint.
2644 logevent("Host key fingerprint is:");
2645 strcpy(logmsg, " ");
2646 hostkey.comment = NULL;
2647 rsa_fingerprint(logmsg + strlen(logmsg),
2648 sizeof(logmsg) - strlen(logmsg), &hostkey);
2652 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2653 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2654 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2656 ssh->v1_local_protoflags =
2657 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2658 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2661 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2662 MD5Update(&md5c, s->keystr1, servkey.bytes);
2663 MD5Update(&md5c, cookie, 8);
2664 MD5Final(s->session_id, &md5c);
2666 for (i = 0; i < 32; i++)
2667 ssh->session_key[i] = random_byte();
2670 * Verify that the `bits' and `bytes' parameters match.
2672 if (hostkey.bits > hostkey.bytes * 8 ||
2673 servkey.bits > servkey.bytes * 8) {
2674 bombout(("SSH1 public keys were badly formatted"));
2678 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2680 s->rsabuf = snewn(s->len, unsigned char);
2682 fatalbox("Out of memory");
2685 * Verify the host key.
2689 * First format the key into a string.
2691 int len = rsastr_len(&hostkey);
2692 char fingerprint[100];
2693 char *keystr = snewn(len, char);
2695 fatalbox("Out of memory");
2696 rsastr_fmt(keystr, &hostkey);
2697 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2698 verify_ssh_host_key(ssh->frontend,
2699 ssh->savedhost, ssh->savedport, "rsa", keystr,
2704 for (i = 0; i < 32; i++) {
2705 s->rsabuf[i] = ssh->session_key[i];
2707 s->rsabuf[i] ^= s->session_id[i];
2710 if (hostkey.bytes > servkey.bytes) {
2711 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2713 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2715 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2717 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2720 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2724 logevent("Encrypted session key");
2727 int cipher_chosen = 0, warn = 0;
2728 char *cipher_string = NULL;
2730 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2731 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2732 if (next_cipher == CIPHER_WARN) {
2733 /* If/when we choose a cipher, warn about it */
2735 } else if (next_cipher == CIPHER_AES) {
2736 /* XXX Probably don't need to mention this. */
2737 logevent("AES not supported in SSH1, skipping");
2739 switch (next_cipher) {
2740 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2741 cipher_string = "3DES"; break;
2742 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2743 cipher_string = "Blowfish"; break;
2744 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2745 cipher_string = "single-DES"; break;
2747 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2751 if (!cipher_chosen) {
2752 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2753 bombout(("Server violates SSH 1 protocol by not "
2754 "supporting 3DES encryption"));
2756 /* shouldn't happen */
2757 bombout(("No supported ciphers found"));
2761 /* Warn about chosen cipher if necessary. */
2763 askcipher(ssh->frontend, cipher_string, 0);
2766 switch (s->cipher_type) {
2767 case SSH_CIPHER_3DES:
2768 logevent("Using 3DES encryption");
2770 case SSH_CIPHER_DES:
2771 logevent("Using single-DES encryption");
2773 case SSH_CIPHER_BLOWFISH:
2774 logevent("Using Blowfish encryption");
2778 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2779 PKT_CHAR, s->cipher_type,
2780 PKT_DATA, cookie, 8,
2781 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2782 PKT_DATA, s->rsabuf, s->len,
2783 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2785 logevent("Trying to enable encryption...");
2789 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2790 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2792 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2793 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2794 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2796 ssh->crcda_ctx = crcda_make_context();
2797 logevent("Installing CRC compensation attack detector");
2799 if (servkey.modulus) {
2800 sfree(servkey.modulus);
2801 servkey.modulus = NULL;
2803 if (servkey.exponent) {
2804 sfree(servkey.exponent);
2805 servkey.exponent = NULL;
2807 if (hostkey.modulus) {
2808 sfree(hostkey.modulus);
2809 hostkey.modulus = NULL;
2811 if (hostkey.exponent) {
2812 sfree(hostkey.exponent);
2813 hostkey.exponent = NULL;
2817 if (pktin->type != SSH1_SMSG_SUCCESS) {
2818 bombout(("Encryption not successfully enabled"));
2822 logevent("Successfully started encryption");
2826 if (!*ssh->cfg.username) {
2827 if (ssh_get_line && !ssh_getline_pw_only) {
2828 if (!ssh_get_line("login as: ",
2829 s->username, sizeof(s->username), FALSE)) {
2831 * get_line failed to get a username.
2834 logevent("No username provided. Abandoning session.");
2835 ssh_closing((Plug)ssh, NULL, 0, 0);
2839 int ret; /* need not be kept over crReturn */
2840 c_write_str(ssh, "login as: ");
2843 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2845 crWaitUntil(!pktin);
2846 ret = process_userpass_input(ssh, in, inlen);
2850 c_write_str(ssh, "\r\n");
2853 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2854 s->username[sizeof(s->username)-1] = '\0';
2857 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2859 char userlog[22 + sizeof(s->username)];
2860 sprintf(userlog, "Sent username \"%s\"", s->username);
2862 if (flags & FLAG_INTERACTIVE &&
2863 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2864 strcat(userlog, "\r\n");
2865 c_write_str(ssh, userlog);
2872 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2873 /* We must not attempt PK auth. Pretend we've already tried it. */
2874 s->tried_publickey = s->tried_agent = 1;
2876 s->tried_publickey = s->tried_agent = 0;
2878 s->tis_auth_refused = s->ccard_auth_refused = 0;
2879 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2880 if (!filename_is_null(ssh->cfg.keyfile)) {
2881 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2882 &s->publickey_blob, &s->publickey_bloblen, NULL))
2883 s->publickey_blob = NULL;
2885 s->publickey_blob = NULL;
2887 while (pktin->type == SSH1_SMSG_FAILURE) {
2888 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2890 if (agent_exists() && !s->tried_agent) {
2892 * Attempt RSA authentication using Pageant.
2898 logevent("Pageant is running. Requesting keys.");
2900 /* Request the keys held by the agent. */
2901 PUT_32BIT(s->request, 1);
2902 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2903 if (!agent_query(s->request, 5, &r, &s->responselen,
2904 ssh_agent_callback, ssh)) {
2908 bombout(("Unexpected data from server while waiting"
2909 " for agent response"));
2912 } while (pktin || inlen > 0);
2913 r = ssh->agent_response;
2914 s->responselen = ssh->agent_response_len;
2916 s->response = (unsigned char *) r;
2917 if (s->response && s->responselen >= 5 &&
2918 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2919 s->p = s->response + 5;
2920 s->nkeys = GET_32BIT(s->p);
2924 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2927 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2930 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2933 if (s->publickey_blob &&
2934 !memcmp(s->p, s->publickey_blob,
2935 s->publickey_bloblen)) {
2936 logevent("This key matches configured key file");
2937 s->tried_publickey = 1;
2942 do { /* do while (0) to make breaking easy */
2943 n = ssh1_read_bignum
2944 (s->p, s->responselen-(s->p-s->response),
2949 n = ssh1_read_bignum
2950 (s->p, s->responselen-(s->p-s->response),
2955 if (s->responselen - (s->p-s->response) < 4)
2957 s->commentlen = GET_32BIT(s->p);
2959 if (s->responselen - (s->p-s->response) <
2962 s->commentp = (char *)s->p;
2963 s->p += s->commentlen;
2967 logevent("Pageant key list packet was truncated");
2971 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2972 PKT_BIGNUM, s->key.modulus, PKT_END);
2974 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2975 logevent("Key refused");
2978 logevent("Received RSA challenge");
2979 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
2980 bombout(("Server's RSA challenge was badly formatted"));
2985 char *agentreq, *q, *ret;
2988 len = 1 + 4; /* message type, bit count */
2989 len += ssh1_bignum_length(s->key.exponent);
2990 len += ssh1_bignum_length(s->key.modulus);
2991 len += ssh1_bignum_length(s->challenge);
2992 len += 16; /* session id */
2993 len += 4; /* response format */
2994 agentreq = snewn(4 + len, char);
2995 PUT_32BIT(agentreq, len);
2997 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2998 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3000 q += ssh1_write_bignum(q, s->key.exponent);
3001 q += ssh1_write_bignum(q, s->key.modulus);
3002 q += ssh1_write_bignum(q, s->challenge);
3003 memcpy(q, s->session_id, 16);
3005 PUT_32BIT(q, 1); /* response format */
3006 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3007 ssh_agent_callback, ssh)) {
3012 bombout(("Unexpected data from server"
3013 " while waiting for agent"
3017 } while (pktin || inlen > 0);
3018 vret = ssh->agent_response;
3019 retlen = ssh->agent_response_len;
3024 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3025 logevent("Sending Pageant's response");
3026 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3027 PKT_DATA, ret + 5, 16,
3031 if (pktin->type == SSH1_SMSG_SUCCESS) {
3033 ("Pageant's response accepted");
3034 if (flags & FLAG_VERBOSE) {
3035 c_write_str(ssh, "Authenticated using"
3037 c_write(ssh, s->commentp,
3039 c_write_str(ssh, "\" from agent\r\n");
3044 ("Pageant's response not accepted");
3047 ("Pageant failed to answer challenge");
3051 logevent("No reply received from Pageant");
3054 freebn(s->key.exponent);
3055 freebn(s->key.modulus);
3056 freebn(s->challenge);
3065 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3066 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3068 if (ssh->cfg.try_tis_auth &&
3069 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3070 !s->tis_auth_refused) {
3071 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3072 logevent("Requested TIS authentication");
3073 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3075 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3076 logevent("TIS authentication declined");
3077 if (flags & FLAG_INTERACTIVE)
3078 c_write_str(ssh, "TIS authentication refused.\r\n");
3079 s->tis_auth_refused = 1;
3085 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3087 bombout(("TIS challenge packet was badly formed"));
3090 logevent("Received TIS challenge");
3091 if (challengelen > sizeof(s->prompt) - 1)
3092 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3093 memcpy(s->prompt, challenge, challengelen);
3094 /* Prompt heuristic comes from OpenSSH */
3095 strncpy(s->prompt + challengelen,
3096 memchr(s->prompt, '\n', challengelen) ?
3097 "": "\r\nResponse: ",
3098 (sizeof s->prompt) - challengelen);
3099 s->prompt[(sizeof s->prompt) - 1] = '\0';
3102 if (ssh->cfg.try_tis_auth &&
3103 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3104 !s->ccard_auth_refused) {
3105 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3106 logevent("Requested CryptoCard authentication");
3107 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3109 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3110 logevent("CryptoCard authentication declined");
3111 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3112 s->ccard_auth_refused = 1;
3118 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3120 bombout(("CryptoCard challenge packet was badly formed"));
3123 logevent("Received CryptoCard challenge");
3124 if (challengelen > sizeof(s->prompt) - 1)
3125 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3126 memcpy(s->prompt, challenge, challengelen);
3127 strncpy(s->prompt + challengelen,
3128 memchr(s->prompt, '\n', challengelen) ?
3129 "" : "\r\nResponse: ",
3130 sizeof(s->prompt) - challengelen);
3131 s->prompt[sizeof(s->prompt) - 1] = '\0';
3134 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3135 sprintf(s->prompt, "%.90s@%.90s's password: ",
3136 s->username, ssh->savedhost);
3138 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3139 char *comment = NULL;
3142 if (flags & FLAG_VERBOSE)
3143 c_write_str(ssh, "Trying public key authentication.\r\n");
3144 logeventf(ssh, "Trying public key \"%s\"",
3145 filename_to_str(&ssh->cfg.keyfile));
3146 type = key_type(&ssh->cfg.keyfile);
3147 if (type != SSH_KEYTYPE_SSH1) {
3148 sprintf(msgbuf, "Key is of wrong type (%s)",
3149 key_type_to_str(type));
3151 c_write_str(ssh, msgbuf);
3152 c_write_str(ssh, "\r\n");
3153 s->tried_publickey = 1;
3156 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3157 if (flags & FLAG_VERBOSE)
3158 c_write_str(ssh, "No passphrase required.\r\n");
3161 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3166 * Show password prompt, having first obtained it via a TIS
3167 * or CryptoCard exchange if we're doing TIS or CryptoCard
3171 if (!ssh_get_line(s->prompt, s->password,
3172 sizeof(s->password), TRUE)) {
3174 * get_line failed to get a password (for example
3175 * because one was supplied on the command line
3176 * which has already failed to work). Terminate.
3178 send_packet(ssh, SSH1_MSG_DISCONNECT,
3179 PKT_STR, "No more passwords available to try",
3181 logevent("Unable to authenticate");
3182 connection_fatal(ssh->frontend, "Unable to authenticate");
3183 ssh_closing((Plug)ssh, NULL, 0, 0);
3187 /* Prompt may have come from server. We've munged it a bit, so
3188 * we know it to be zero-terminated at least once. */
3189 int ret; /* need not be saved over crReturn */
3190 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3193 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3195 crWaitUntil(!pktin);
3196 ret = process_userpass_input(ssh, in, inlen);
3200 c_write_str(ssh, "\r\n");
3204 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3206 * Try public key authentication with the specified
3209 s->tried_publickey = 1;
3212 const char *error = NULL;
3213 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3216 c_write_str(ssh, "Couldn't load private key from ");
3217 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3218 c_write_str(ssh, " (");
3219 c_write_str(ssh, error);
3220 c_write_str(ssh, ").\r\n");
3221 continue; /* go and try password */
3224 c_write_str(ssh, "Wrong passphrase.\r\n");
3225 s->tried_publickey = 0;
3226 continue; /* try again */
3231 * Send a public key attempt.
3233 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3234 PKT_BIGNUM, s->key.modulus, PKT_END);
3237 if (pktin->type == SSH1_SMSG_FAILURE) {
3238 c_write_str(ssh, "Server refused our public key.\r\n");
3239 continue; /* go and try password */
3241 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3242 bombout(("Bizarre response to offer of public key"));
3248 unsigned char buffer[32];
3249 Bignum challenge, response;
3251 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3252 bombout(("Server's RSA challenge was badly formatted"));
3255 response = rsadecrypt(challenge, &s->key);
3256 freebn(s->key.private_exponent);/* burn the evidence */
3258 for (i = 0; i < 32; i++) {
3259 buffer[i] = bignum_byte(response, 31 - i);
3263 MD5Update(&md5c, buffer, 32);
3264 MD5Update(&md5c, s->session_id, 16);
3265 MD5Final(buffer, &md5c);
3267 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3268 PKT_DATA, buffer, 16, PKT_END);
3275 if (pktin->type == SSH1_SMSG_FAILURE) {
3276 if (flags & FLAG_VERBOSE)
3277 c_write_str(ssh, "Failed to authenticate with"
3278 " our public key.\r\n");
3279 continue; /* go and try password */
3280 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3281 bombout(("Bizarre response to RSA authentication response"));
3285 break; /* we're through! */
3287 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3289 * Defence against traffic analysis: we send a
3290 * whole bunch of packets containing strings of
3291 * different lengths. One of these strings is the
3292 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3293 * The others are all random data in
3294 * SSH1_MSG_IGNORE packets. This way a passive
3295 * listener can't tell which is the password, and
3296 * hence can't deduce the password length.
3298 * Anybody with a password length greater than 16
3299 * bytes is going to have enough entropy in their
3300 * password that a listener won't find it _that_
3301 * much help to know how long it is. So what we'll
3304 * - if password length < 16, we send 15 packets
3305 * containing string lengths 1 through 15
3307 * - otherwise, we let N be the nearest multiple
3308 * of 8 below the password length, and send 8
3309 * packets containing string lengths N through
3310 * N+7. This won't obscure the order of
3311 * magnitude of the password length, but it will
3312 * introduce a bit of extra uncertainty.
3314 * A few servers (the old 1.2.18 through 1.2.22)
3315 * can't deal with SSH1_MSG_IGNORE. For these
3316 * servers, we need an alternative defence. We make
3317 * use of the fact that the password is interpreted
3318 * as a C string: so we can append a NUL, then some
3321 * One server (a Cisco one) can deal with neither
3322 * SSH1_MSG_IGNORE _nor_ a padded password string.
3323 * For this server we are left with no defences
3324 * against password length sniffing.
3326 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3328 * The server can deal with SSH1_MSG_IGNORE, so
3329 * we can use the primary defence.
3331 int bottom, top, pwlen, i;
3334 pwlen = strlen(s->password);
3336 bottom = 0; /* zero length passwords are OK! :-) */
3339 bottom = pwlen & ~7;
3343 assert(pwlen >= bottom && pwlen <= top);
3345 randomstr = snewn(top + 1, char);
3347 for (i = bottom; i <= top; i++) {
3349 defer_packet(ssh, s->pwpkt_type,
3350 PKTT_PASSWORD, PKT_STR, s->password,
3351 PKTT_OTHER, PKT_END);
3353 for (j = 0; j < i; j++) {
3355 randomstr[j] = random_byte();
3356 } while (randomstr[j] == '\0');
3358 randomstr[i] = '\0';
3359 defer_packet(ssh, SSH1_MSG_IGNORE,
3360 PKT_STR, randomstr, PKT_END);
3363 logevent("Sending password with camouflage packets");
3364 ssh_pkt_defersend(ssh);
3367 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3369 * The server can't deal with SSH1_MSG_IGNORE
3370 * but can deal with padded passwords, so we
3371 * can use the secondary defence.
3377 len = strlen(s->password);
3378 if (len < sizeof(string)) {
3380 strcpy(string, s->password);
3381 len++; /* cover the zero byte */
3382 while (len < sizeof(string)) {
3383 string[len++] = (char) random_byte();
3388 logevent("Sending length-padded password");
3389 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3390 PKT_INT, len, PKT_DATA, ss, len,
3391 PKTT_OTHER, PKT_END);
3394 * The server has _both_
3395 * BUG_CHOKES_ON_SSH1_IGNORE and
3396 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3397 * therefore nothing we can do.
3400 len = strlen(s->password);
3401 logevent("Sending unpadded password");
3402 send_packet(ssh, s->pwpkt_type,
3403 PKTT_PASSWORD, PKT_INT, len,
3404 PKT_DATA, s->password, len,
3405 PKTT_OTHER, PKT_END);
3408 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3409 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3412 logevent("Sent password");
3413 memset(s->password, 0, strlen(s->password));
3415 if (pktin->type == SSH1_SMSG_FAILURE) {
3416 if (flags & FLAG_VERBOSE)
3417 c_write_str(ssh, "Access denied\r\n");
3418 logevent("Authentication refused");
3419 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3420 bombout(("Strange packet received, type %d", pktin->type));
3425 logevent("Authentication successful");
3430 void sshfwd_close(struct ssh_channel *c)
3434 if (ssh->state != SSH_STATE_SESSION) {
3435 assert(ssh->state == SSH_STATE_CLOSED);
3439 if (c && !c->closes) {
3441 * If the channel's remoteid is -1, we have sent
3442 * CHANNEL_OPEN for this channel, but it hasn't even been
3443 * acknowledged by the server. So we must set a close flag
3444 * on it now, and then when the server acks the channel
3445 * open, we can close it then.
3447 if (((int)c->remoteid) != -1) {
3448 if (ssh->version == 1) {
3449 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3452 struct Packet *pktout;
3453 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3454 ssh2_pkt_adduint32(pktout, c->remoteid);
3455 ssh2_pkt_send(ssh, pktout);
3458 c->closes = 1; /* sent MSG_CLOSE */
3459 if (c->type == CHAN_X11) {
3461 logevent("Forwarded X11 connection terminated");
3462 } else if (c->type == CHAN_SOCKDATA ||
3463 c->type == CHAN_SOCKDATA_DORMANT) {
3465 logevent("Forwarded port closed");
3470 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3474 if (ssh->state != SSH_STATE_SESSION) {
3475 assert(ssh->state == SSH_STATE_CLOSED);
3479 if (ssh->version == 1) {
3480 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3481 PKT_INT, c->remoteid,
3483 PKT_INT, len, PKT_DATA, buf, len,
3484 PKTT_OTHER, PKT_END);
3486 * In SSH1 we can return 0 here - implying that forwarded
3487 * connections are never individually throttled - because
3488 * the only circumstance that can cause throttling will be
3489 * the whole SSH connection backing up, in which case
3490 * _everything_ will be throttled as a whole.
3494 ssh2_add_channel_data(c, buf, len);
3495 return ssh2_try_send(c);
3499 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3503 if (ssh->state != SSH_STATE_SESSION) {
3504 assert(ssh->state == SSH_STATE_CLOSED);
3508 if (ssh->version == 1) {
3509 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3510 c->v.v1.throttling = 0;
3511 ssh1_throttle(ssh, -1);
3514 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3518 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3521 int stringlen, bufsize;
3523 ssh_pkt_getstring(pktin, &string, &stringlen);
3524 if (string == NULL) {
3525 bombout(("Incoming terminal data packet was badly formed"));
3529 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3531 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3532 ssh->v1_stdout_throttling = 1;
3533 ssh1_throttle(ssh, +1);
3537 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3539 /* Remote side is trying to open a channel to talk to our
3540 * X-Server. Give them back a local channel number. */
3541 struct ssh_channel *c;
3542 int remoteid = ssh_pkt_getuint32(pktin);
3544 logevent("Received X11 connect request");
3545 /* Refuse if X11 forwarding is disabled. */
3546 if (!ssh->X11_fwd_enabled) {
3547 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3548 PKT_INT, remoteid, PKT_END);
3549 logevent("Rejected X11 connect request");
3551 c = snew(struct ssh_channel);
3554 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3555 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3556 logevent("Opening X11 forward connection failed");
3558 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3559 PKT_INT, remoteid, PKT_END);
3562 ("Opening X11 forward connection succeeded");
3563 c->remoteid = remoteid;
3564 c->localid = alloc_channel_id(ssh);
3566 c->v.v1.throttling = 0;
3567 c->type = CHAN_X11; /* identify channel type */
3568 add234(ssh->channels, c);
3569 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3570 PKT_INT, c->remoteid, PKT_INT,
3571 c->localid, PKT_END);
3572 logevent("Opened X11 forward channel");
3577 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3579 /* Remote side is trying to open a channel to talk to our
3580 * agent. Give them back a local channel number. */
3581 struct ssh_channel *c;
3582 int remoteid = ssh_pkt_getuint32(pktin);
3584 /* Refuse if agent forwarding is disabled. */
3585 if (!ssh->agentfwd_enabled) {
3586 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3587 PKT_INT, remoteid, PKT_END);
3589 c = snew(struct ssh_channel);
3591 c->remoteid = remoteid;
3592 c->localid = alloc_channel_id(ssh);
3594 c->v.v1.throttling = 0;
3595 c->type = CHAN_AGENT; /* identify channel type */
3596 c->u.a.lensofar = 0;
3597 add234(ssh->channels, c);
3598 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3599 PKT_INT, c->remoteid, PKT_INT, c->localid,
3604 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3606 /* Remote side is trying to open a channel to talk to a
3607 * forwarded port. Give them back a local channel number. */
3608 struct ssh_channel *c;
3609 struct ssh_rportfwd pf;
3612 char *host, buf[1024];
3614 c = snew(struct ssh_channel);
3617 remoteid = ssh_pkt_getuint32(pktin);
3618 ssh_pkt_getstring(pktin, &host, &hostsize);
3619 port = ssh_pkt_getuint32(pktin);
3621 if (hostsize >= lenof(pf.dhost))
3622 hostsize = lenof(pf.dhost)-1;
3623 memcpy(pf.dhost, host, hostsize);
3624 pf.dhost[hostsize] = '\0';
3627 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3628 sprintf(buf, "Rejected remote port open request for %s:%d",
3631 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3632 PKT_INT, remoteid, PKT_END);
3634 sprintf(buf, "Received remote port open request for %s:%d",
3637 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3641 sprintf(buf, "Port open failed: %s", e);
3644 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3645 PKT_INT, remoteid, PKT_END);
3647 c->remoteid = remoteid;
3648 c->localid = alloc_channel_id(ssh);
3650 c->v.v1.throttling = 0;
3651 c->type = CHAN_SOCKDATA; /* identify channel type */
3652 add234(ssh->channels, c);
3653 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3654 PKT_INT, c->remoteid, PKT_INT,
3655 c->localid, PKT_END);
3656 logevent("Forwarded port opened successfully");
3661 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3663 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3664 unsigned int localid = ssh_pkt_getuint32(pktin);
3665 struct ssh_channel *c;
3667 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3668 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3669 c->remoteid = localid;
3670 c->type = CHAN_SOCKDATA;
3671 c->v.v1.throttling = 0;
3672 pfd_confirm(c->u.pfd.s);
3675 if (c && c->closes) {
3677 * We have a pending close on this channel,
3678 * which we decided on before the server acked
3679 * the channel open. So now we know the
3680 * remoteid, we can close it again.
3682 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3683 PKT_INT, c->remoteid, PKT_END);
3687 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3689 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3690 struct ssh_channel *c;
3692 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3693 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3694 logevent("Forwarded connection refused by server");
3695 pfd_close(c->u.pfd.s);
3696 del234(ssh->channels, c);
3701 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3703 /* Remote side closes a channel. */
3704 unsigned i = ssh_pkt_getuint32(pktin);
3705 struct ssh_channel *c;
3706 c = find234(ssh->channels, &i, ssh_channelfind);
3707 if (c && ((int)c->remoteid) != -1) {
3710 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3712 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3713 logevent("Forwarded X11 connection terminated");
3714 assert(c->u.x11.s != NULL);
3715 x11_close(c->u.x11.s);
3718 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3719 logevent("Forwarded port closed");
3720 assert(c->u.pfd.s != NULL);
3721 pfd_close(c->u.pfd.s);
3725 c->closes |= (closetype << 2); /* seen this message */
3726 if (!(c->closes & closetype)) {
3727 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3729 c->closes |= closetype; /* sent it too */
3732 if (c->closes == 15) {
3733 del234(ssh->channels, c);
3737 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3738 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3739 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3744 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3746 /* Data sent down one of our channels. */
3747 int i = ssh_pkt_getuint32(pktin);
3750 struct ssh_channel *c;
3752 ssh_pkt_getstring(pktin, &p, &len);
3754 c = find234(ssh->channels, &i, ssh_channelfind);
3759 bufsize = x11_send(c->u.x11.s, p, len);
3762 bufsize = pfd_send(c->u.pfd.s, p, len);
3765 /* Data for an agent message. Buffer it. */
3767 if (c->u.a.lensofar < 4) {
3768 int l = min(4 - c->u.a.lensofar, len);
3769 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3773 c->u.a.lensofar += l;
3775 if (c->u.a.lensofar == 4) {
3777 4 + GET_32BIT(c->u.a.msglen);
3778 c->u.a.message = snewn(c->u.a.totallen,
3780 memcpy(c->u.a.message, c->u.a.msglen, 4);
3782 if (c->u.a.lensofar >= 4 && len > 0) {
3784 min(c->u.a.totallen - c->u.a.lensofar,
3786 memcpy(c->u.a.message + c->u.a.lensofar, p,
3790 c->u.a.lensofar += l;
3792 if (c->u.a.lensofar == c->u.a.totallen) {
3795 if (agent_query(c->u.a.message,
3798 ssh_agentf_callback, c))
3799 ssh_agentf_callback(c, reply, replylen);
3800 sfree(c->u.a.message);
3801 c->u.a.lensofar = 0;
3804 bufsize = 0; /* agent channels never back up */
3807 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3808 c->v.v1.throttling = 1;
3809 ssh1_throttle(ssh, +1);
3814 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3817 ssh->exitcode = ssh_pkt_getuint32(pktin);
3818 sprintf(buf, "Server sent command exit status %d",
3821 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3823 * In case `helpful' firewalls or proxies tack
3824 * extra human-readable text on the end of the
3825 * session which we might mistake for another
3826 * encrypted packet, we close the session once
3827 * we've sent EXIT_CONFIRMATION.
3829 ssh_closing((Plug)ssh, NULL, 0, 0);
3832 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3833 struct Packet *pktin)
3835 crBegin(ssh->do_ssh1_connection_crstate);
3837 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3838 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3839 ssh1_smsg_stdout_stderr_data;
3841 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3842 ssh1_msg_channel_open_confirmation;
3843 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3844 ssh1_msg_channel_open_failure;
3845 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3846 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3847 ssh1_msg_channel_close;
3848 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3849 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3851 if (ssh->cfg.agentfwd && agent_exists()) {
3852 logevent("Requesting agent forwarding");
3853 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3857 if (pktin->type != SSH1_SMSG_SUCCESS
3858 && pktin->type != SSH1_SMSG_FAILURE) {
3859 bombout(("Protocol confusion"));
3861 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3862 logevent("Agent forwarding refused");
3864 logevent("Agent forwarding enabled");
3865 ssh->agentfwd_enabled = TRUE;
3866 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
3870 if (ssh->cfg.x11_forward) {
3871 char proto[20], data[64];
3872 logevent("Requesting X11 forwarding");
3873 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3874 data, sizeof(data), ssh->cfg.x11_auth);
3875 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3876 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3877 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3878 PKT_STR, proto, PKT_STR, data,
3879 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3882 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3883 PKT_STR, proto, PKT_STR, data, PKT_END);
3888 if (pktin->type != SSH1_SMSG_SUCCESS
3889 && pktin->type != SSH1_SMSG_FAILURE) {
3890 bombout(("Protocol confusion"));
3892 } else if (pktin->type == SSH1_SMSG_FAILURE) {
3893 logevent("X11 forwarding refused");
3895 logevent("X11 forwarding enabled");
3896 ssh->X11_fwd_enabled = TRUE;
3897 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
3904 int sport,dport,sserv,dserv;
3905 char sports[256], dports[256], saddr[256], host[256];
3907 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3908 /* Add port forwardings. */
3909 ssh->portfwd_strptr = ssh->cfg.portfwd;
3910 while (*ssh->portfwd_strptr) {
3911 type = *ssh->portfwd_strptr++;
3914 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3915 if (*ssh->portfwd_strptr == ':') {
3917 * We've seen a colon in the middle of the
3918 * source port number. This means that
3919 * everything we've seen until now is the
3920 * source _address_, so we'll move it into
3921 * saddr and start sports from the beginning
3924 ssh->portfwd_strptr++;
3926 strcpy(saddr, sports);
3929 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3933 if (*ssh->portfwd_strptr == '\t')
3934 ssh->portfwd_strptr++;
3936 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3937 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3940 if (*ssh->portfwd_strptr == ':')
3941 ssh->portfwd_strptr++;
3943 while (*ssh->portfwd_strptr) {
3944 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3947 ssh->portfwd_strptr++;
3948 dport = atoi(dports);
3952 dport = net_service_lookup(dports);
3954 logeventf(ssh, "Service lookup failed for"
3955 " destination port \"%s\"", dports);
3959 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3961 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3963 sport = atoi(sports);
3967 sport = net_service_lookup(sports);
3969 logeventf(ssh, "Service lookup failed for source"
3970 " port \"%s\"", sports);
3973 if (sport && dport) {
3974 /* Set up a description of the source port. */
3975 static char *sportdesc;
3976 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3977 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3978 (int)(*saddr?1:0), ":",
3979 (int)(sserv ? strlen(sports) : 0), sports,
3980 sserv, "(", sport, sserv, ")");
3982 /* Verbose description of the destination port */
3983 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3985 (int)(dserv ? strlen(dports) : 0), dports,
3986 dserv, "(", dport, dserv, ")");
3987 const char *err = pfd_addforward(host, dport,
3988 *saddr ? saddr : NULL,
3989 sport, ssh, &ssh->cfg);
3991 logeventf(ssh, "Local port %s forward to %s"
3992 " failed: %s", sportdesc, dportdesc, err);
3994 logeventf(ssh, "Local port %s forwarding to %s",
3995 sportdesc, dportdesc);
3998 } else if (type == 'D') {
3999 const char *err = pfd_addforward(NULL, -1,
4000 *saddr ? saddr : NULL,
4001 sport, ssh, &ssh->cfg);
4003 logeventf(ssh, "Local port %s SOCKS dynamic forward"
4004 " setup failed: %s", sportdesc, err);
4006 logeventf(ssh, "Local port %s doing SOCKS"
4007 " dynamic forwarding", sportdesc);
4010 struct ssh_rportfwd *pf;
4011 pf = snew(struct ssh_rportfwd);
4012 strcpy(pf->dhost, host);
4016 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
4019 if (add234(ssh->rportfwds, pf) != pf) {
4021 "Duplicate remote port forwarding to %s:%d",
4025 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
4026 " forward to %s:%.*s%.*s%d%.*s",
4027 (int)(sserv ? strlen(sports) : 0), sports,
4028 sserv, "(", sport, sserv, ")",
4030 (int)(dserv ? strlen(dports) : 0), dports,
4031 dserv, "(", dport, dserv, ")");
4032 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4040 if (pktin->type != SSH1_SMSG_SUCCESS
4041 && pktin->type != SSH1_SMSG_FAILURE) {
4042 bombout(("Protocol confusion"));
4044 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4045 c_write_str(ssh, "Server refused port"
4047 logevent("Server refused this port forwarding");
4049 logevent("Remote port forwarding enabled");
4050 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4060 if (!ssh->cfg.nopty) {
4061 /* Unpick the terminal-speed string. */
4062 /* XXX perhaps we should allow no speeds to be sent. */
4063 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4064 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4065 /* Send the pty request. */
4066 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4067 PKT_STR, ssh->cfg.termtype,
4068 PKT_INT, ssh->term_height,
4069 PKT_INT, ssh->term_width,
4070 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4071 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4072 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4073 PKT_CHAR, 0, PKT_END);
4074 ssh->state = SSH_STATE_INTERMED;
4078 if (pktin->type != SSH1_SMSG_SUCCESS
4079 && pktin->type != SSH1_SMSG_FAILURE) {
4080 bombout(("Protocol confusion"));
4082 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4083 c_write_str(ssh, "Server refused to allocate pty\r\n");
4084 ssh->editing = ssh->echoing = 1;
4086 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4087 ssh->ospeed, ssh->ispeed);
4089 ssh->editing = ssh->echoing = 1;
4092 if (ssh->cfg.compression) {
4093 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4097 if (pktin->type != SSH1_SMSG_SUCCESS
4098 && pktin->type != SSH1_SMSG_FAILURE) {
4099 bombout(("Protocol confusion"));
4101 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4102 c_write_str(ssh, "Server refused to compress\r\n");
4104 logevent("Started compression");
4105 ssh->v1_compressing = TRUE;
4106 ssh->cs_comp_ctx = zlib_compress_init();
4107 logevent("Initialised zlib (RFC1950) compression");
4108 ssh->sc_comp_ctx = zlib_decompress_init();
4109 logevent("Initialised zlib (RFC1950) decompression");
4113 * Start the shell or command.
4115 * Special case: if the first-choice command is an SSH2
4116 * subsystem (hence not usable here) and the second choice
4117 * exists, we fall straight back to that.
4120 char *cmd = ssh->cfg.remote_cmd_ptr;
4122 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4123 cmd = ssh->cfg.remote_cmd_ptr2;
4124 ssh->fallback_cmd = TRUE;
4127 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4129 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4130 logevent("Started session");
4133 ssh->state = SSH_STATE_SESSION;
4134 if (ssh->size_needed)
4135 ssh_size(ssh, ssh->term_width, ssh->term_height);
4136 if (ssh->eof_needed)
4137 ssh_special(ssh, TS_EOF);
4140 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4142 ssh->channels = newtree234(ssh_channelcmp);
4146 * By this point, most incoming packets are already being
4147 * handled by the dispatch table, and we need only pay
4148 * attention to the unusual ones.
4153 if (pktin->type == SSH1_SMSG_SUCCESS) {
4154 /* may be from EXEC_SHELL on some servers */
4155 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4156 /* may be from EXEC_SHELL on some servers
4157 * if no pty is available or in other odd cases. Ignore */
4159 bombout(("Strange packet received: type %d", pktin->type));
4164 int len = min(inlen, 512);
4165 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4166 PKT_INT, len, PKT_DATA, in, len,
4167 PKTT_OTHER, PKT_END);
4178 * Handle the top-level SSH2 protocol.
4180 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4185 ssh_pkt_getstring(pktin, &msg, &msglen);
4186 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4191 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4193 /* log reason code in disconnect message */
4197 ssh_pkt_getstring(pktin, &msg, &msglen);
4198 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4201 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4203 /* Do nothing, because we're ignoring it! Duhh. */
4206 static void ssh1_protocol_setup(Ssh ssh)
4211 * Most messages are handled by the coroutines.
4213 for (i = 0; i < 256; i++)
4214 ssh->packet_dispatch[i] = NULL;
4217 * These special message types we install handlers for.
4219 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4220 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4221 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4224 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4225 struct Packet *pktin)
4227 if (ssh->state == SSH_STATE_CLOSED)
4230 if (pktin && ssh->packet_dispatch[pktin->type]) {
4231 ssh->packet_dispatch[pktin->type](ssh, pktin);
4235 if (!ssh->protocol_initial_phase_done) {
4236 if (do_ssh1_login(ssh, in, inlen, pktin))
4237 ssh->protocol_initial_phase_done = TRUE;
4242 do_ssh1_connection(ssh, in, inlen, pktin);
4246 * Utility routine for decoding comma-separated strings in KEXINIT.
4248 static int in_commasep_string(char *needle, char *haystack, int haylen)
4251 if (!needle || !haystack) /* protect against null pointers */
4253 needlen = strlen(needle);
4256 * Is it at the start of the string?
4258 if (haylen >= needlen && /* haystack is long enough */
4259 !memcmp(needle, haystack, needlen) && /* initial match */
4260 (haylen == needlen || haystack[needlen] == ',')
4261 /* either , or EOS follows */
4265 * If not, search for the next comma and resume after that.
4266 * If no comma found, terminate.
4268 while (haylen > 0 && *haystack != ',')
4269 haylen--, haystack++;
4272 haylen--, haystack++; /* skip over comma itself */
4277 * SSH2 key creation method.
4279 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4280 unsigned char *sessid, char chr,
4281 unsigned char *keyspace)
4284 /* First 20 bytes. */
4286 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4288 SHA_Bytes(&s, H, 20);
4289 SHA_Bytes(&s, &chr, 1);
4290 SHA_Bytes(&s, sessid, 20);
4291 SHA_Final(&s, keyspace);
4292 /* Next 20 bytes. */
4294 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4296 SHA_Bytes(&s, H, 20);
4297 SHA_Bytes(&s, keyspace, 20);
4298 SHA_Final(&s, keyspace + 20);
4302 * Handle the SSH2 transport layer.
4304 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4305 struct Packet *pktin)
4307 struct do_ssh2_transport_state {
4308 int nbits, pbits, warn;
4309 Bignum p, g, e, f, K;
4310 int kex_init_value, kex_reply_value;
4311 const struct ssh_mac **maclist;
4313 const struct ssh2_cipher *cscipher_tobe;
4314 const struct ssh2_cipher *sccipher_tobe;
4315 const struct ssh_mac *csmac_tobe;
4316 const struct ssh_mac *scmac_tobe;
4317 const struct ssh_compress *cscomp_tobe;
4318 const struct ssh_compress *sccomp_tobe;
4319 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4320 int hostkeylen, siglen;
4321 void *hkey; /* actual host key */
4322 unsigned char exchange_hash[20];
4323 int n_preferred_ciphers;
4324 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4325 const struct ssh_compress *preferred_comp;
4327 struct Packet *pktout;
4329 crState(do_ssh2_transport_state);
4331 crBegin(ssh->do_ssh2_transport_crstate);
4333 s->cscipher_tobe = s->sccipher_tobe = NULL;
4334 s->csmac_tobe = s->scmac_tobe = NULL;
4335 s->cscomp_tobe = s->sccomp_tobe = NULL;
4342 * Set up the preferred ciphers. (NULL => warn below here)
4344 s->n_preferred_ciphers = 0;
4345 for (i = 0; i < CIPHER_MAX; i++) {
4346 switch (ssh->cfg.ssh_cipherlist[i]) {
4347 case CIPHER_BLOWFISH:
4348 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4351 if (ssh->cfg.ssh2_des_cbc) {
4352 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4356 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4359 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4362 /* Flag for later. Don't bother if it's the last in
4364 if (i < CIPHER_MAX - 1) {
4365 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4373 * Set up preferred compression.
4375 if (ssh->cfg.compression)
4376 s->preferred_comp = &ssh_zlib;
4378 s->preferred_comp = &ssh_comp_none;
4381 * Be prepared to work around the buggy MAC problem.
4383 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4384 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4386 s->maclist = macs, s->nmacs = lenof(macs);
4390 int i, j, cipherstr_started;
4393 * Enable queueing of outgoing auth- or connection-layer
4394 * packets while we are in the middle of a key exchange.
4396 ssh->queueing = TRUE;
4399 * Flag that KEX is in progress.
4401 ssh->kex_in_progress = TRUE;
4404 * Construct and send our key exchange packet.
4406 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4407 for (i = 0; i < 16; i++)
4408 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4409 /* List key exchange algorithms. */
4410 ssh2_pkt_addstring_start(s->pktout);
4411 for (i = 0; i < lenof(kex_algs); i++) {
4412 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4413 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4415 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
4416 if (i < lenof(kex_algs) - 1)
4417 ssh2_pkt_addstring_str(s->pktout, ",");
4419 /* List server host key algorithms. */
4420 ssh2_pkt_addstring_start(s->pktout);
4421 for (i = 0; i < lenof(hostkey_algs); i++) {
4422 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4423 if (i < lenof(hostkey_algs) - 1)
4424 ssh2_pkt_addstring_str(s->pktout, ",");
4426 /* List client->server encryption algorithms. */
4427 ssh2_pkt_addstring_start(s->pktout);
4428 cipherstr_started = 0;
4429 for (i = 0; i < s->n_preferred_ciphers; i++) {
4430 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4431 if (!c) continue; /* warning flag */
4432 for (j = 0; j < c->nciphers; j++) {
4433 if (cipherstr_started)
4434 ssh2_pkt_addstring_str(s->pktout, ",");
4435 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4436 cipherstr_started = 1;
4439 /* List server->client encryption algorithms. */
4440 ssh2_pkt_addstring_start(s->pktout);
4441 cipherstr_started = 0;
4442 for (i = 0; i < s->n_preferred_ciphers; i++) {
4443 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4444 if (!c) continue; /* warning flag */
4445 for (j = 0; j < c->nciphers; j++) {
4446 if (cipherstr_started)
4447 ssh2_pkt_addstring_str(s->pktout, ",");
4448 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4449 cipherstr_started = 1;
4452 /* List client->server MAC algorithms. */
4453 ssh2_pkt_addstring_start(s->pktout);
4454 for (i = 0; i < s->nmacs; i++) {
4455 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4456 if (i < s->nmacs - 1)
4457 ssh2_pkt_addstring_str(s->pktout, ",");
4459 /* List server->client MAC algorithms. */
4460 ssh2_pkt_addstring_start(s->pktout);
4461 for (i = 0; i < s->nmacs; i++) {
4462 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4463 if (i < s->nmacs - 1)
4464 ssh2_pkt_addstring_str(s->pktout, ",");
4466 /* List client->server compression algorithms. */
4467 ssh2_pkt_addstring_start(s->pktout);
4468 assert(lenof(compressions) > 1);
4469 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4470 for (i = 0; i < lenof(compressions); i++) {
4471 const struct ssh_compress *c = compressions[i];
4472 if (c != s->preferred_comp) {
4473 ssh2_pkt_addstring_str(s->pktout, ",");
4474 ssh2_pkt_addstring_str(s->pktout, c->name);
4477 /* List server->client compression algorithms. */
4478 ssh2_pkt_addstring_start(s->pktout);
4479 assert(lenof(compressions) > 1);
4480 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4481 for (i = 0; i < lenof(compressions); i++) {
4482 const struct ssh_compress *c = compressions[i];
4483 if (c != s->preferred_comp) {
4484 ssh2_pkt_addstring_str(s->pktout, ",");
4485 ssh2_pkt_addstring_str(s->pktout, c->name);
4488 /* List client->server languages. Empty list. */
4489 ssh2_pkt_addstring_start(s->pktout);
4490 /* List server->client languages. Empty list. */
4491 ssh2_pkt_addstring_start(s->pktout);
4492 /* First KEX packet does _not_ follow, because we're not that brave. */
4493 ssh2_pkt_addbool(s->pktout, FALSE);
4495 ssh2_pkt_adduint32(s->pktout, 0);
4498 ssh->exhash = ssh->exhashbase;
4499 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4501 ssh2_pkt_send_noqueue(ssh, s->pktout);
4505 if (pktin->length > 5)
4506 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4509 * Now examine the other side's KEXINIT to see what we're up
4516 if (pktin->type != SSH2_MSG_KEXINIT) {
4517 bombout(("expected key exchange packet from server"));
4521 ssh->hostkey = NULL;
4522 s->cscipher_tobe = NULL;
4523 s->sccipher_tobe = NULL;
4524 s->csmac_tobe = NULL;
4525 s->scmac_tobe = NULL;
4526 s->cscomp_tobe = NULL;
4527 s->sccomp_tobe = NULL;
4528 pktin->savedpos += 16; /* skip garbage cookie */
4529 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4530 for (i = 0; i < lenof(kex_algs); i++) {
4531 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4532 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4534 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4535 ssh->kex = kex_algs[i];
4539 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4540 for (i = 0; i < lenof(hostkey_algs); i++) {
4541 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4542 ssh->hostkey = hostkey_algs[i];
4546 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4548 for (i = 0; i < s->n_preferred_ciphers; i++) {
4549 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4553 for (j = 0; j < c->nciphers; j++) {
4554 if (in_commasep_string(c->list[j]->name, str, len)) {
4555 s->cscipher_tobe = c->list[j];
4560 if (s->cscipher_tobe) {
4562 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4566 if (!s->cscipher_tobe) {
4567 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4568 str ? str : "(null)"));
4572 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4574 for (i = 0; i < s->n_preferred_ciphers; i++) {
4575 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4579 for (j = 0; j < c->nciphers; j++) {
4580 if (in_commasep_string(c->list[j]->name, str, len)) {
4581 s->sccipher_tobe = c->list[j];
4586 if (s->sccipher_tobe) {
4588 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4592 if (!s->sccipher_tobe) {
4593 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4594 str ? str : "(null)"));
4598 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4599 for (i = 0; i < s->nmacs; i++) {
4600 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4601 s->csmac_tobe = s->maclist[i];
4605 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4606 for (i = 0; i < s->nmacs; i++) {
4607 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4608 s->scmac_tobe = s->maclist[i];
4612 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
4613 for (i = 0; i < lenof(compressions) + 1; i++) {
4614 const struct ssh_compress *c =
4615 i == 0 ? s->preferred_comp : compressions[i - 1];
4616 if (in_commasep_string(c->name, str, len)) {
4621 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
4622 for (i = 0; i < lenof(compressions) + 1; i++) {
4623 const struct ssh_compress *c =
4624 i == 0 ? s->preferred_comp : compressions[i - 1];
4625 if (in_commasep_string(c->name, str, len)) {
4633 * Work out the number of bits of key we will need from the key
4634 * exchange. We start with the maximum key length of either
4640 csbits = s->cscipher_tobe->keylen;
4641 scbits = s->sccipher_tobe->keylen;
4642 s->nbits = (csbits > scbits ? csbits : scbits);
4644 /* The keys only have 160-bit entropy, since they're based on
4645 * a SHA-1 hash. So cap the key size at 160 bits. */
4650 * If we're doing Diffie-Hellman group exchange, start by
4651 * requesting a group.
4653 if (ssh->kex == &ssh_diffiehellman_gex) {
4654 logevent("Doing Diffie-Hellman group exchange");
4655 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4657 * Work out how big a DH group we will need to allow that
4660 s->pbits = 512 << ((s->nbits - 1) / 64);
4661 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4662 ssh2_pkt_adduint32(s->pktout, s->pbits);
4663 ssh2_pkt_send_noqueue(ssh, s->pktout);
4666 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4667 bombout(("expected key exchange group packet from server"));
4670 s->p = ssh2_pkt_getmp(pktin);
4671 s->g = ssh2_pkt_getmp(pktin);
4672 if (!s->p || !s->g) {
4673 bombout(("unable to read mp-ints from incoming group packet"));
4676 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4677 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4678 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4680 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4681 ssh->kex_ctx = dh_setup_group1();
4682 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4683 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4686 logevent("Doing Diffie-Hellman key exchange");
4688 * Now generate and send e for Diffie-Hellman.
4690 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4691 s->pktout = ssh2_pkt_init(s->kex_init_value);
4692 ssh2_pkt_addmp(s->pktout, s->e);
4693 ssh2_pkt_send_noqueue(ssh, s->pktout);
4696 if (pktin->type != s->kex_reply_value) {
4697 bombout(("expected key exchange reply packet from server"));
4700 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4701 s->f = ssh2_pkt_getmp(pktin);
4703 bombout(("unable to parse key exchange reply packet"));
4706 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
4708 s->K = dh_find_K(ssh->kex_ctx, s->f);
4710 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4711 if (ssh->kex == &ssh_diffiehellman_gex) {
4712 sha_uint32(&ssh->exhash, s->pbits);
4713 sha_mpint(&ssh->exhash, s->p);
4714 sha_mpint(&ssh->exhash, s->g);
4716 sha_mpint(&ssh->exhash, s->e);
4717 sha_mpint(&ssh->exhash, s->f);
4718 sha_mpint(&ssh->exhash, s->K);
4719 SHA_Final(&ssh->exhash, s->exchange_hash);
4721 dh_cleanup(ssh->kex_ctx);
4722 ssh->kex_ctx = NULL;
4725 debug(("Exchange hash is:\n"));
4726 dmemdump(s->exchange_hash, 20);
4729 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4731 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4732 (char *)s->exchange_hash, 20)) {
4733 bombout(("Server's host key did not match the signature supplied"));
4738 * Authenticate remote host: verify host key. (We've already
4739 * checked the signature of the exchange hash.)
4741 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4742 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4743 verify_ssh_host_key(ssh->frontend,
4744 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4745 s->keystr, s->fingerprint);
4746 if (s->first_kex) { /* don't bother logging this in rekeys */
4747 logevent("Host key fingerprint is:");
4748 logevent(s->fingerprint);
4750 sfree(s->fingerprint);
4752 ssh->hostkey->freekey(s->hkey);
4755 * The exchange hash from the very first key exchange is also
4756 * the session id, used in session key construction and
4760 memcpy(ssh->v2_session_id, s->exchange_hash,
4761 sizeof(s->exchange_hash));
4764 * Send SSH2_MSG_NEWKEYS.
4766 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
4767 ssh2_pkt_send_noqueue(ssh, s->pktout);
4768 ssh->outgoing_data_size = 0; /* start counting from here */
4771 * We've sent client NEWKEYS, so create and initialise
4772 * client-to-server session keys.
4774 if (ssh->cs_cipher_ctx)
4775 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4776 ssh->cscipher = s->cscipher_tobe;
4777 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4779 if (ssh->cs_mac_ctx)
4780 ssh->csmac->free_context(ssh->cs_mac_ctx);
4781 ssh->csmac = s->csmac_tobe;
4782 ssh->cs_mac_ctx = ssh->csmac->make_context();
4784 if (ssh->cs_comp_ctx)
4785 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4786 ssh->cscomp = s->cscomp_tobe;
4787 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4790 * Set IVs on client-to-server keys. Here we use the exchange
4791 * hash from the _first_ key exchange.
4794 unsigned char keyspace[40];
4795 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4796 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4797 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4798 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4799 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4800 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4803 logeventf(ssh, "Initialised %.200s client->server encryption",
4804 ssh->cscipher->text_name);
4805 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4806 ssh->csmac->text_name);
4807 if (ssh->cscomp->text_name)
4808 logeventf(ssh, "Initialised %s compression",
4809 ssh->cscomp->text_name);
4812 * Now our end of the key exchange is complete, we can send all
4813 * our queued higher-layer packets.
4815 ssh->queueing = FALSE;
4816 ssh2_pkt_queuesend(ssh);
4819 * Expect SSH2_MSG_NEWKEYS from server.
4822 if (pktin->type != SSH2_MSG_NEWKEYS) {
4823 bombout(("expected new-keys packet from server"));
4826 ssh->incoming_data_size = 0; /* start counting from here */
4829 * We've seen server NEWKEYS, so create and initialise
4830 * server-to-client session keys.
4832 if (ssh->sc_cipher_ctx)
4833 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4834 ssh->sccipher = s->sccipher_tobe;
4835 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4837 if (ssh->sc_mac_ctx)
4838 ssh->scmac->free_context(ssh->sc_mac_ctx);
4839 ssh->scmac = s->scmac_tobe;
4840 ssh->sc_mac_ctx = ssh->scmac->make_context();
4842 if (ssh->sc_comp_ctx)
4843 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4844 ssh->sccomp = s->sccomp_tobe;
4845 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4848 * Set IVs on server-to-client keys. Here we use the exchange
4849 * hash from the _first_ key exchange.
4852 unsigned char keyspace[40];
4853 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4854 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4855 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4856 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4857 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4858 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4860 logeventf(ssh, "Initialised %.200s server->client encryption",
4861 ssh->sccipher->text_name);
4862 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4863 ssh->scmac->text_name);
4864 if (ssh->sccomp->text_name)
4865 logeventf(ssh, "Initialised %s decompression",
4866 ssh->sccomp->text_name);
4869 * Free key exchange data.
4873 if (ssh->kex == &ssh_diffiehellman_gex) {
4879 * Key exchange is over. Schedule a timer for our next rekey.
4881 ssh->kex_in_progress = FALSE;
4882 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4885 * If this is the first key exchange phase, we must pass the
4886 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4887 * wants to see it but because it will need time to initialise
4888 * itself before it sees an actual packet. In subsequent key
4889 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4890 * it would only confuse the layer above.
4892 if (!s->first_kex) {
4898 * Now we're encrypting. Begin returning 1 to the protocol main
4899 * function so that other things can run on top of the
4900 * transport. If we ever see a KEXINIT, we must go back to the
4903 * We _also_ go back to the start if we see pktin==NULL and
4904 * inlen==-1, because this is a special signal meaning
4905 * `initiate client-driven rekey', and `in' contains a message
4906 * giving the reason for the rekey.
4908 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4909 (!pktin && inlen == -1))) {
4913 logevent("Server initiated key re-exchange");
4915 logevent((char *)in);
4917 goto begin_key_exchange;
4923 * Add data to an SSH2 channel output buffer.
4925 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4928 bufchain_add(&c->v.v2.outbuffer, buf, len);
4932 * Attempt to send data on an SSH2 channel.
4934 static int ssh2_try_send(struct ssh_channel *c)
4937 struct Packet *pktout;
4939 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4942 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4943 if ((unsigned)len > c->v.v2.remwindow)
4944 len = c->v.v2.remwindow;
4945 if ((unsigned)len > c->v.v2.remmaxpkt)
4946 len = c->v.v2.remmaxpkt;
4947 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4948 ssh2_pkt_adduint32(pktout, c->remoteid);
4949 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4950 ssh2_pkt_addstring_start(pktout);
4951 ssh2_pkt_addstring_data(pktout, data, len);
4952 end_log_omission(ssh, pktout);
4953 ssh2_pkt_send(ssh, pktout);
4954 bufchain_consume(&c->v.v2.outbuffer, len);
4955 c->v.v2.remwindow -= len;
4959 * After having sent as much data as we can, return the amount
4962 return bufchain_size(&c->v.v2.outbuffer);
4966 * Potentially enlarge the window on an SSH2 channel.
4968 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4973 * Never send WINDOW_ADJUST for a channel that the remote side
4974 * already thinks it's closed; there's no point, since it won't
4975 * be sending any more data anyway.
4980 if (newwin > c->v.v2.locwindow) {
4981 struct Packet *pktout;
4983 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4984 ssh2_pkt_adduint32(pktout, c->remoteid);
4985 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4986 ssh2_pkt_send(ssh, pktout);
4987 c->v.v2.locwindow = newwin;
4991 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
4993 unsigned i = ssh_pkt_getuint32(pktin);
4994 struct ssh_channel *c;
4995 c = find234(ssh->channels, &i, ssh_channelfind);
4996 if (c && !c->closes)
4997 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5000 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5004 unsigned i = ssh_pkt_getuint32(pktin);
5005 struct ssh_channel *c;
5006 c = find234(ssh->channels, &i, ssh_channelfind);
5008 return; /* nonexistent channel */
5009 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5010 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5011 return; /* extended but not stderr */
5012 ssh_pkt_getstring(pktin, &data, &length);
5015 c->v.v2.locwindow -= length;
5017 case CHAN_MAINSESSION:
5019 from_backend(ssh->frontend, pktin->type ==
5020 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5024 bufsize = x11_send(c->u.x11.s, data, length);
5027 bufsize = pfd_send(c->u.pfd.s, data, length);
5030 while (length > 0) {
5031 if (c->u.a.lensofar < 4) {
5032 int l = min(4 - c->u.a.lensofar, length);
5033 memcpy(c->u.a.msglen + c->u.a.lensofar,
5037 c->u.a.lensofar += l;
5039 if (c->u.a.lensofar == 4) {
5041 4 + GET_32BIT(c->u.a.msglen);
5042 c->u.a.message = snewn(c->u.a.totallen,
5044 memcpy(c->u.a.message, c->u.a.msglen, 4);
5046 if (c->u.a.lensofar >= 4 && length > 0) {
5048 min(c->u.a.totallen - c->u.a.lensofar,
5050 memcpy(c->u.a.message + c->u.a.lensofar,
5054 c->u.a.lensofar += l;
5056 if (c->u.a.lensofar == c->u.a.totallen) {
5059 if (agent_query(c->u.a.message,
5062 ssh_agentf_callback, c))
5063 ssh_agentf_callback(c, reply, replylen);
5064 sfree(c->u.a.message);
5065 c->u.a.lensofar = 0;
5072 * If we are not buffering too much data,
5073 * enlarge the window again at the remote side.
5075 if (bufsize < OUR_V2_WINSIZE)
5076 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5080 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5082 unsigned i = ssh_pkt_getuint32(pktin);
5083 struct ssh_channel *c;
5085 c = find234(ssh->channels, &i, ssh_channelfind);
5087 return; /* nonexistent channel */
5089 if (c->type == CHAN_X11) {
5091 * Remote EOF on an X11 channel means we should
5092 * wrap up and close the channel ourselves.
5094 x11_close(c->u.x11.s);
5096 } else if (c->type == CHAN_AGENT) {
5098 } else if (c->type == CHAN_SOCKDATA) {
5099 pfd_close(c->u.pfd.s);
5104 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5106 unsigned i = ssh_pkt_getuint32(pktin);
5107 struct ssh_channel *c;
5108 struct Packet *pktout;
5110 c = find234(ssh->channels, &i, ssh_channelfind);
5111 if (!c || ((int)c->remoteid) == -1) {
5112 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5113 c ? "half-open" : "nonexistent", i));
5116 /* Do pre-close processing on the channel. */
5118 case CHAN_MAINSESSION:
5119 ssh->mainchan = NULL;
5120 update_specials_menu(ssh->frontend);
5123 if (c->u.x11.s != NULL)
5124 x11_close(c->u.x11.s);
5131 if (c->u.pfd.s != NULL)
5132 pfd_close(c->u.pfd.s);
5136 if (c->closes == 0) {
5137 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5138 ssh2_pkt_adduint32(pktout, c->remoteid);
5139 ssh2_pkt_send(ssh, pktout);
5141 del234(ssh->channels, c);
5142 bufchain_clear(&c->v.v2.outbuffer);
5146 * See if that was the last channel left open.
5147 * (This is only our termination condition if we're
5148 * not running in -N mode.)
5150 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5151 logevent("All channels closed. Disconnecting");
5154 * We used to send SSH_MSG_DISCONNECT here,
5155 * because I'd believed that _every_ conforming
5156 * SSH2 connection had to end with a disconnect
5157 * being sent by at least one side; apparently
5158 * I was wrong and it's perfectly OK to
5159 * unceremoniously slam the connection shut
5160 * when you're done, and indeed OpenSSH feels
5161 * this is more polite than sending a
5162 * DISCONNECT. So now we don't.
5164 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5165 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5166 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5167 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5168 ssh2_pkt_send_noqueue(ssh, s->pktout);
5170 ssh_closing((Plug)ssh, NULL, 0, 0);
5174 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5176 unsigned i = ssh_pkt_getuint32(pktin);
5177 struct ssh_channel *c;
5178 struct Packet *pktout;
5180 c = find234(ssh->channels, &i, ssh_channelfind);
5182 return; /* nonexistent channel */
5183 if (c->type != CHAN_SOCKDATA_DORMANT)
5184 return; /* dunno why they're confirming this */
5185 c->remoteid = ssh_pkt_getuint32(pktin);
5186 c->type = CHAN_SOCKDATA;
5187 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5188 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5190 pfd_confirm(c->u.pfd.s);
5193 * We have a pending close on this channel,
5194 * which we decided on before the server acked
5195 * the channel open. So now we know the
5196 * remoteid, we can close it again.
5198 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5199 ssh2_pkt_adduint32(pktout, c->remoteid);
5200 ssh2_pkt_send(ssh, pktout);
5204 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5206 static const char *const reasons[] = {
5207 "<unknown reason code>",
5208 "Administratively prohibited",
5210 "Unknown channel type",
5211 "Resource shortage",
5213 unsigned i = ssh_pkt_getuint32(pktin);
5214 unsigned reason_code;
5215 char *reason_string;
5218 struct ssh_channel *c;
5219 c = find234(ssh->channels, &i, ssh_channelfind);
5221 return; /* nonexistent channel */
5222 if (c->type != CHAN_SOCKDATA_DORMANT)
5223 return; /* dunno why they're failing this */
5225 reason_code = ssh_pkt_getuint32(pktin);
5226 if (reason_code >= lenof(reasons))
5227 reason_code = 0; /* ensure reasons[reason_code] in range */
5228 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5229 message = dupprintf("Forwarded connection refused by"
5230 " server: %s [%.*s]", reasons[reason_code],
5231 reason_length, reason_string);
5235 pfd_close(c->u.pfd.s);
5237 del234(ssh->channels, c);
5241 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5245 int typelen, want_reply;
5246 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5247 struct ssh_channel *c;
5248 struct Packet *pktout;
5250 localid = ssh_pkt_getuint32(pktin);
5251 ssh_pkt_getstring(pktin, &type, &typelen);
5252 want_reply = ssh2_pkt_getbool(pktin);
5255 * First, check that the channel exists. Otherwise,
5256 * we can instantly disconnect with a rude message.
5258 c = find234(ssh->channels, &localid, ssh_channelfind);
5261 sprintf(buf, "Received channel request for nonexistent"
5262 " channel %d", localid);
5264 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5265 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5266 ssh2_pkt_addstring(pktout, buf);
5267 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5268 ssh2_pkt_send_noqueue(ssh, pktout);
5269 connection_fatal(ssh->frontend, "%s", buf);
5270 ssh_closing((Plug)ssh, NULL, 0, 0);
5275 * Having got the channel number, we now look at
5276 * the request type string to see if it's something
5279 if (c == ssh->mainchan) {
5281 * We recognise "exit-status" and "exit-signal" on
5282 * the primary channel.
5284 if (typelen == 11 &&
5285 !memcmp(type, "exit-status", 11)) {
5287 ssh->exitcode = ssh_pkt_getuint32(pktin);
5288 logeventf(ssh, "Server sent command exit status %d",
5290 reply = SSH2_MSG_CHANNEL_SUCCESS;
5292 } else if (typelen == 11 &&
5293 !memcmp(type, "exit-signal", 11)) {
5295 int is_plausible = TRUE, is_int = FALSE;
5296 char *fmt_sig = "", *fmt_msg = "";
5298 int msglen = 0, core = FALSE;
5299 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5300 * provide an `int' for the signal, despite its
5301 * having been a `string' in the drafts since at
5302 * least 2001. (Fixed in session.c 1.147.) Try to
5303 * infer which we can safely parse it as. */
5305 unsigned char *p = pktin->body +
5307 long len = pktin->length - pktin->savedpos;
5308 unsigned long num = GET_32BIT(p); /* what is it? */
5309 /* If it's 0, it hardly matters; assume string */
5313 int maybe_int = FALSE, maybe_str = FALSE;
5314 #define CHECK_HYPOTHESIS(offset, result) \
5317 if (q >= 0 && q+4 <= len) { \
5318 q = q + 4 + GET_32BIT(p+q); \
5319 if (q >= 0 && q+4 <= len && \
5320 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5324 CHECK_HYPOTHESIS(4+1, maybe_int);
5325 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5326 #undef CHECK_HYPOTHESIS
5327 if (maybe_int && !maybe_str)
5329 else if (!maybe_int && maybe_str)
5332 /* Crikey. Either or neither. Panic. */
5333 is_plausible = FALSE;
5338 /* Old non-standard OpenSSH. */
5339 int signum = ssh_pkt_getuint32(pktin);
5340 fmt_sig = dupprintf(" %d", signum);
5342 /* As per the drafts. */
5345 ssh_pkt_getstring(pktin, &sig, &siglen);
5346 /* Signal name isn't supposed to be blank, but
5347 * let's cope gracefully if it is. */
5349 fmt_sig = dupprintf(" \"%.*s\"",
5353 core = ssh2_pkt_getbool(pktin);
5354 ssh_pkt_getstring(pktin, &msg, &msglen);
5356 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5358 /* ignore lang tag */
5359 } /* else don't attempt to parse */
5360 logeventf(ssh, "Server exited on signal%s%s%s",
5361 fmt_sig, core ? " (core dumped)" : "",
5363 if (*fmt_sig) sfree(fmt_sig);
5364 if (*fmt_msg) sfree(fmt_msg);
5365 reply = SSH2_MSG_CHANNEL_SUCCESS;
5370 * This is a channel request we don't know
5371 * about, so we now either ignore the request
5372 * or respond with CHANNEL_FAILURE, depending
5375 reply = SSH2_MSG_CHANNEL_FAILURE;
5378 pktout = ssh2_pkt_init(reply);
5379 ssh2_pkt_adduint32(pktout, c->remoteid);
5380 ssh2_pkt_send(ssh, pktout);
5384 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5387 int typelen, want_reply;
5388 struct Packet *pktout;
5390 ssh_pkt_getstring(pktin, &type, &typelen);
5391 want_reply = ssh2_pkt_getbool(pktin);
5394 * We currently don't support any global requests
5395 * at all, so we either ignore the request or
5396 * respond with REQUEST_FAILURE, depending on
5400 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5401 ssh2_pkt_send(ssh, pktout);
5405 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5413 struct ssh_channel *c;
5414 unsigned remid, winsize, pktsize;
5415 struct Packet *pktout;
5417 ssh_pkt_getstring(pktin, &type, &typelen);
5418 c = snew(struct ssh_channel);
5421 remid = ssh_pkt_getuint32(pktin);
5422 winsize = ssh_pkt_getuint32(pktin);
5423 pktsize = ssh_pkt_getuint32(pktin);
5425 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5428 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5429 addrstr = snewn(peeraddrlen+1, char);
5430 memcpy(addrstr, peeraddr, peeraddrlen);
5431 addrstr[peeraddrlen] = '\0';
5432 peerport = ssh_pkt_getuint32(pktin);
5434 logeventf(ssh, "Received X11 connect request from %s:%d",
5437 if (!ssh->X11_fwd_enabled)
5438 error = "X11 forwarding is not enabled";
5439 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5440 ssh->x11auth, addrstr, peerport,
5441 &ssh->cfg) != NULL) {
5442 error = "Unable to open an X11 connection";
5444 logevent("Opening X11 forward connection succeeded");
5449 } else if (typelen == 15 &&
5450 !memcmp(type, "forwarded-tcpip", 15)) {
5451 struct ssh_rportfwd pf, *realpf;
5454 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5455 pf.sport = ssh_pkt_getuint32(pktin);
5456 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5457 peerport = ssh_pkt_getuint32(pktin);
5458 realpf = find234(ssh->rportfwds, &pf, NULL);
5459 logeventf(ssh, "Received remote port %d open request "
5460 "from %s:%d", pf.sport, peeraddr, peerport);
5461 if (realpf == NULL) {
5462 error = "Remote port is not recognised";
5464 const char *e = pfd_newconnect(&c->u.pfd.s,
5468 logeventf(ssh, "Attempting to forward remote port to "
5469 "%s:%d", realpf->dhost, realpf->dport);
5471 logeventf(ssh, "Port open failed: %s", e);
5472 error = "Port open failed";
5474 logevent("Forwarded port opened successfully");
5475 c->type = CHAN_SOCKDATA;
5478 } else if (typelen == 22 &&
5479 !memcmp(type, "auth-agent@openssh.com", 3)) {
5480 if (!ssh->agentfwd_enabled)
5481 error = "Agent forwarding is not enabled";
5483 c->type = CHAN_AGENT; /* identify channel type */
5484 c->u.a.lensofar = 0;
5487 error = "Unsupported channel type requested";
5490 c->remoteid = remid;
5492 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5493 ssh2_pkt_adduint32(pktout, c->remoteid);
5494 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5495 ssh2_pkt_addstring(pktout, error);
5496 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5497 ssh2_pkt_send(ssh, pktout);
5498 logeventf(ssh, "Rejected channel open: %s", error);
5501 c->localid = alloc_channel_id(ssh);
5503 c->v.v2.locwindow = OUR_V2_WINSIZE;
5504 c->v.v2.remwindow = winsize;
5505 c->v.v2.remmaxpkt = pktsize;
5506 bufchain_init(&c->v.v2.outbuffer);
5507 add234(ssh->channels, c);
5508 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5509 ssh2_pkt_adduint32(pktout, c->remoteid);
5510 ssh2_pkt_adduint32(pktout, c->localid);
5511 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5512 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5513 ssh2_pkt_send(ssh, pktout);
5518 * Handle the SSH2 userauth and connection layers.
5520 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5521 struct Packet *pktin)
5523 struct do_ssh2_authconn_state {
5525 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5527 AUTH_KEYBOARD_INTERACTIVE
5531 AUTH_TYPE_PUBLICKEY,
5532 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5533 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5535 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5536 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5538 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5539 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5540 int kbd_inter_running;
5542 int num_prompts, curr_prompt, echo;
5547 void *publickey_blob;
5548 int publickey_bloblen;
5549 unsigned char request[5], *response, *p;
5553 char *pkblob, *alg, *commentp;
5554 int pklen, alglen, commentlen;
5555 int siglen, retlen, len;
5556 char *q, *agentreq, *ret;
5558 int num_env, env_left, env_ok;
5559 struct Packet *pktout;
5561 crState(do_ssh2_authconn_state);
5563 crBegin(ssh->do_ssh2_authconn_crstate);
5566 * Request userauth protocol, and await a response to it.
5568 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5569 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5570 ssh2_pkt_send(ssh, s->pktout);
5571 crWaitUntilV(pktin);
5572 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
5573 bombout(("Server refused user authentication protocol"));
5578 * We repeat this whole loop, including the username prompt,
5579 * until we manage a successful authentication. If the user
5580 * types the wrong _password_, they can be sent back to the
5581 * beginning to try another username, if this is configured on.
5582 * (If they specify a username in the config, they are never
5583 * asked, even if they do give a wrong password.)
5585 * I think this best serves the needs of
5587 * - the people who have no configuration, no keys, and just
5588 * want to try repeated (username,password) pairs until they
5589 * type both correctly
5591 * - people who have keys and configuration but occasionally
5592 * need to fall back to passwords
5594 * - people with a key held in Pageant, who might not have
5595 * logged in to a particular machine before; so they want to
5596 * type a username, and then _either_ their key will be
5597 * accepted, _or_ they will type a password. If they mistype
5598 * the username they will want to be able to get back and
5601 s->username[0] = '\0';
5602 s->got_username = FALSE;
5607 if (s->got_username && !ssh->cfg.change_username) {
5609 * We got a username last time round this loop, and
5610 * with change_username turned off we don't try to get
5613 } else if (!*ssh->cfg.username) {
5614 if (ssh_get_line && !ssh_getline_pw_only) {
5615 if (!ssh_get_line("login as: ",
5616 s->username, sizeof(s->username), FALSE)) {
5618 * get_line failed to get a username.
5621 logevent("No username provided. Abandoning session.");
5622 ssh_closing((Plug)ssh, NULL, 0, 0);
5626 int ret; /* need not be saved across crReturn */
5627 c_write_str(ssh, "login as: ");
5629 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
5631 crWaitUntilV(!pktin);
5632 ret = process_userpass_input(ssh, in, inlen);
5636 c_write_str(ssh, "\r\n");
5638 s->username[strcspn(s->username, "\n\r")] = '\0';
5641 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
5642 s->username[sizeof(s->username)-1] = '\0';
5643 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
5644 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
5645 c_write_str(ssh, stuff);
5649 s->got_username = TRUE;
5652 * Send an authentication request using method "none": (a)
5653 * just in case it succeeds, and (b) so that we know what
5654 * authentication methods we can usefully try next.
5656 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5658 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5659 ssh2_pkt_addstring(s->pktout, s->username);
5660 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5661 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5662 ssh2_pkt_send(ssh, s->pktout);
5663 s->type = AUTH_TYPE_NONE;
5665 s->we_are_in = FALSE;
5667 s->tried_pubkey_config = FALSE;
5668 s->tried_agent = FALSE;
5669 s->tried_keyb_inter = FALSE;
5670 s->kbd_inter_running = FALSE;
5671 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
5672 if (!filename_is_null(ssh->cfg.keyfile)) {
5674 logeventf(ssh, "Reading private key file \"%.150s\"",
5675 filename_to_str(&ssh->cfg.keyfile));
5676 keytype = key_type(&ssh->cfg.keyfile);
5677 if (keytype == SSH_KEYTYPE_SSH2) {
5679 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
5680 &s->publickey_bloblen, NULL);
5683 logeventf(ssh, "Unable to use this key file (%s)",
5684 key_type_to_str(keytype));
5685 msgbuf = dupprintf("Unable to use key file \"%.150s\""
5687 filename_to_str(&ssh->cfg.keyfile),
5688 key_type_to_str(keytype));
5689 c_write_str(ssh, msgbuf);
5691 s->publickey_blob = NULL;
5694 s->publickey_blob = NULL;
5698 * Wait for the result of the last authentication request.
5701 crWaitUntilV(pktin);
5702 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
5706 * Don't show the banner if we're operating in
5707 * non-verbose non-interactive mode. (It's probably
5708 * a script, which means nobody will read the
5709 * banner _anyway_, and moreover the printing of
5710 * the banner will screw up processing on the
5711 * output of (say) plink.)
5713 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
5714 ssh_pkt_getstring(pktin, &banner, &size);
5716 c_write_untrusted(ssh, banner, size);
5718 crWaitUntilV(pktin);
5720 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
5721 logevent("Access granted");
5722 s->we_are_in = TRUE;
5726 if (s->kbd_inter_running &&
5727 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
5729 * This is either a further set-of-prompts packet
5730 * in keyboard-interactive authentication, or it's
5731 * the same one and we came back here with `gotit'
5732 * set. In the former case, we must reset the
5733 * curr_prompt variable.
5737 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
5738 bombout(("Strange packet received during authentication: type %d",
5746 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5747 * we can look at the string in it and know what we can
5748 * helpfully try next.
5750 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
5753 ssh_pkt_getstring(pktin, &methods, &methlen);
5754 s->kbd_inter_running = FALSE;
5755 if (!ssh2_pkt_getbool(pktin)) {
5757 * We have received an unequivocal Access
5758 * Denied. This can translate to a variety of
5761 * - if we'd just tried "none" authentication,
5762 * it's not worth printing anything at all
5764 * - if we'd just tried a public key _offer_,
5765 * the message should be "Server refused our
5766 * key" (or no message at all if the key
5767 * came from Pageant)
5769 * - if we'd just tried anything else, the
5770 * message really should be "Access denied".
5772 * Additionally, if we'd just tried password
5773 * authentication, we should break out of this
5774 * whole loop so as to go back to the username
5775 * prompt (iff we're configured to allow
5776 * username change attempts).
5778 if (s->type == AUTH_TYPE_NONE) {
5780 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5781 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5782 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5783 c_write_str(ssh, "Server refused our key\r\n");
5784 logevent("Server refused public key");
5785 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5786 /* server declined keyboard-interactive; ignore */
5788 c_write_str(ssh, "Access denied\r\n");
5789 logevent("Access denied");
5790 if (s->type == AUTH_TYPE_PASSWORD &&
5791 ssh->cfg.change_username) {
5792 /* XXX perhaps we should allow
5793 * keyboard-interactive to do this too? */
5794 s->we_are_in = FALSE;
5799 c_write_str(ssh, "Further authentication required\r\n");
5800 logevent("Further authentication required");
5804 in_commasep_string("publickey", methods, methlen);
5806 in_commasep_string("password", methods, methlen);
5807 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5808 in_commasep_string("keyboard-interactive", methods, methlen);
5812 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5816 * Most password/passphrase prompts will be
5817 * non-echoing, so we set this to 0 by default.
5818 * Exception is that some keyboard-interactive prompts
5819 * can be echoing, in which case we'll set this to 1.
5823 if (!s->method && s->can_pubkey &&
5824 agent_exists() && !s->tried_agent) {
5826 * Attempt public-key authentication using Pageant.
5831 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5832 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5834 s->tried_agent = TRUE;
5836 logevent("Pageant is running. Requesting keys.");
5838 /* Request the keys held by the agent. */
5839 PUT_32BIT(s->request, 1);
5840 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5841 if (!agent_query(s->request, 5, &r, &s->responselen,
5842 ssh_agent_callback, ssh)) {
5846 bombout(("Unexpected data from server while"
5847 " waiting for agent response"));
5850 } while (pktin || inlen > 0);
5851 r = ssh->agent_response;
5852 s->responselen = ssh->agent_response_len;
5854 s->response = (unsigned char *) r;
5855 if (s->response && s->responselen >= 5 &&
5856 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5857 s->p = s->response + 5;
5858 s->nkeys = GET_32BIT(s->p);
5862 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5865 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5870 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5873 s->pklen = GET_32BIT(s->p);
5875 if (s->publickey_blob &&
5876 s->pklen == s->publickey_bloblen &&
5877 !memcmp(s->p, s->publickey_blob,
5878 s->publickey_bloblen)) {
5879 logevent("This key matches configured key file");
5880 s->tried_pubkey_config = 1;
5882 s->pkblob = (char *)s->p;
5884 s->alglen = GET_32BIT(s->pkblob);
5885 s->alg = s->pkblob + 4;
5886 s->commentlen = GET_32BIT(s->p);
5888 s->commentp = (char *)s->p;
5889 s->p += s->commentlen;
5890 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5891 ssh2_pkt_addstring(s->pktout, s->username);
5892 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5893 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5894 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5895 ssh2_pkt_addstring_start(s->pktout);
5896 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5897 ssh2_pkt_addstring_start(s->pktout);
5898 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5899 ssh2_pkt_send(ssh, s->pktout);
5901 crWaitUntilV(pktin);
5902 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
5903 logevent("Key refused");
5907 if (flags & FLAG_VERBOSE) {
5908 c_write_str(ssh, "Authenticating with "
5910 c_write(ssh, s->commentp, s->commentlen);
5911 c_write_str(ssh, "\" from agent\r\n");
5915 * Server is willing to accept the key.
5916 * Construct a SIGN_REQUEST.
5918 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5919 ssh2_pkt_addstring(s->pktout, s->username);
5920 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5921 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5922 ssh2_pkt_addbool(s->pktout, TRUE);
5923 ssh2_pkt_addstring_start(s->pktout);
5924 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5925 ssh2_pkt_addstring_start(s->pktout);
5926 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5928 s->siglen = s->pktout->length - 5 + 4 + 20;
5929 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5931 s->len = 1; /* message type */
5932 s->len += 4 + s->pklen; /* key blob */
5933 s->len += 4 + s->siglen; /* data to sign */
5934 s->len += 4; /* flags */
5935 s->agentreq = snewn(4 + s->len, char);
5936 PUT_32BIT(s->agentreq, s->len);
5937 s->q = s->agentreq + 4;
5938 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5939 PUT_32BIT(s->q, s->pklen);
5941 memcpy(s->q, s->pkblob, s->pklen);
5943 PUT_32BIT(s->q, s->siglen);
5945 /* Now the data to be signed... */
5946 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5947 PUT_32BIT(s->q, 20);
5950 memcpy(s->q, ssh->v2_session_id, 20);
5952 memcpy(s->q, s->pktout->data + 5,
5953 s->pktout->length - 5);
5954 s->q += s->pktout->length - 5;
5955 /* And finally the (zero) flags word. */
5957 if (!agent_query(s->agentreq, s->len + 4,
5959 ssh_agent_callback, ssh)) {
5963 bombout(("Unexpected data from server"
5964 " while waiting for agent"
5968 } while (pktin || inlen > 0);
5969 vret = ssh->agent_response;
5970 s->retlen = ssh->agent_response_len;
5975 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5976 logevent("Sending Pageant's response");
5977 ssh2_add_sigblob(ssh, s->pktout,
5978 s->pkblob, s->pklen,
5980 GET_32BIT(s->ret + 5));
5981 ssh2_pkt_send(ssh, s->pktout);
5986 ("Pageant failed to answer challenge");
5997 if (!s->method && s->can_pubkey && s->publickey_blob
5998 && !s->tried_pubkey_config) {
5999 unsigned char *pub_blob;
6000 char *algorithm, *comment;
6003 s->tried_pubkey_config = TRUE;
6005 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6006 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6009 * Try the public key supplied in the configuration.
6011 * First, offer the public blob to see if the server is
6012 * willing to accept it.
6015 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6020 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6021 ssh2_pkt_addstring(s->pktout, s->username);
6022 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6023 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6024 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6025 ssh2_pkt_addstring(s->pktout, algorithm);
6026 ssh2_pkt_addstring_start(s->pktout);
6027 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6029 ssh2_pkt_send(ssh, s->pktout);
6030 logevent("Offered public key");
6032 crWaitUntilV(pktin);
6033 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6035 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6036 continue; /* key refused; give up on it */
6039 logevent("Offer of public key accepted");
6041 * Actually attempt a serious authentication using
6044 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6045 sprintf(s->pwprompt,
6046 "Passphrase for key \"%.100s\": ",
6052 if (flags & FLAG_VERBOSE) {
6053 c_write_str(ssh, "Authenticating with public key \"");
6054 c_write_str(ssh, comment);
6055 c_write_str(ssh, "\"\r\n");
6057 s->method = AUTH_PUBLICKEY_FILE;
6061 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6062 s->method = AUTH_KEYBOARD_INTERACTIVE;
6063 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6064 s->tried_keyb_inter = TRUE;
6066 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6067 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6069 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6070 ssh2_pkt_addstring(s->pktout, s->username);
6071 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6072 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6073 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6074 ssh2_pkt_addstring(s->pktout, "");
6075 ssh2_pkt_send(ssh, s->pktout);
6077 crWaitUntilV(pktin);
6078 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6079 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6081 logevent("Keyboard-interactive authentication refused");
6082 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6086 s->kbd_inter_running = TRUE;
6090 if (s->kbd_inter_running) {
6091 s->method = AUTH_KEYBOARD_INTERACTIVE;
6092 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6093 s->tried_keyb_inter = TRUE;
6095 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6096 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6098 if (s->curr_prompt == 0) {
6100 * We've got a fresh USERAUTH_INFO_REQUEST.
6101 * Display header data, and start going through
6104 char *name, *inst, *lang;
6105 int name_len, inst_len, lang_len;
6107 ssh_pkt_getstring(pktin, &name, &name_len);
6108 ssh_pkt_getstring(pktin, &inst, &inst_len);
6109 ssh_pkt_getstring(pktin, &lang, &lang_len);
6111 c_write_untrusted(ssh, name, name_len);
6112 c_write_str(ssh, "\r\n");
6115 c_write_untrusted(ssh, inst, inst_len);
6116 c_write_str(ssh, "\r\n");
6118 s->num_prompts = ssh_pkt_getuint32(pktin);
6122 * If there are prompts remaining in the packet,
6123 * display one and get a response.
6125 if (s->curr_prompt < s->num_prompts) {
6129 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6130 if (prompt_len > 0) {
6131 static const char trunc[] = "<prompt truncated>: ";
6132 static const int prlen = sizeof(s->pwprompt) -
6134 if (prompt_len > prlen) {
6135 memcpy(s->pwprompt, prompt, prlen);
6136 strcpy(s->pwprompt + prlen, trunc);
6138 memcpy(s->pwprompt, prompt, prompt_len);
6139 s->pwprompt[prompt_len] = '\0';
6143 "<server failed to send prompt>: ");
6145 s->echo = ssh2_pkt_getbool(pktin);
6151 if (!s->method && s->can_passwd) {
6152 s->method = AUTH_PASSWORD;
6153 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6154 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6155 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6162 if (!ssh_get_line(s->pwprompt, s->password,
6163 sizeof(s->password), TRUE)) {
6165 * get_line failed to get a password (for
6166 * example because one was supplied on the
6167 * command line which has already failed to
6170 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6171 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6172 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6174 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6175 ssh2_pkt_send_noqueue(ssh, s->pktout);
6176 logevent("Unable to authenticate");
6177 connection_fatal(ssh->frontend,
6178 "Unable to authenticate");
6179 ssh_closing((Plug)ssh, NULL, 0, 0);
6183 int ret; /* need not be saved across crReturn */
6184 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6187 setup_userpass_input(ssh, s->password,
6188 sizeof(s->password), s->echo);
6190 crWaitUntilV(!pktin);
6191 ret = process_userpass_input(ssh, in, inlen);
6195 c_write_str(ssh, "\r\n");
6199 if (s->method == AUTH_PUBLICKEY_FILE) {
6201 * We have our passphrase. Now try the actual authentication.
6203 struct ssh2_userkey *key;
6204 const char *error = NULL;
6206 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6208 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6209 if (key == SSH2_WRONG_PASSPHRASE) {
6210 c_write_str(ssh, "Wrong passphrase\r\n");
6211 s->tried_pubkey_config = FALSE;
6213 c_write_str(ssh, "Unable to load private key (");
6214 c_write_str(ssh, error);
6215 c_write_str(ssh, ")\r\n");
6216 s->tried_pubkey_config = TRUE;
6218 /* Send a spurious AUTH_NONE to return to the top. */
6219 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6220 ssh2_pkt_addstring(s->pktout, s->username);
6221 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6222 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6223 ssh2_pkt_send(ssh, s->pktout);
6224 s->type = AUTH_TYPE_NONE;
6226 unsigned char *pkblob, *sigblob, *sigdata;
6227 int pkblob_len, sigblob_len, sigdata_len;
6231 * We have loaded the private key and the server
6232 * has announced that it's willing to accept it.
6233 * Hallelujah. Generate a signature and send it.
6235 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6236 ssh2_pkt_addstring(s->pktout, s->username);
6237 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6238 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6239 ssh2_pkt_addbool(s->pktout, TRUE);
6240 ssh2_pkt_addstring(s->pktout, key->alg->name);
6241 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6242 ssh2_pkt_addstring_start(s->pktout);
6243 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6246 * The data to be signed is:
6250 * followed by everything so far placed in the
6253 sigdata_len = s->pktout->length - 5 + 4 + 20;
6254 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6256 sigdata = snewn(sigdata_len, unsigned char);
6258 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6259 PUT_32BIT(sigdata+p, 20);
6262 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6263 memcpy(sigdata+p, s->pktout->data + 5,
6264 s->pktout->length - 5);
6265 p += s->pktout->length - 5;
6266 assert(p == sigdata_len);
6267 sigblob = key->alg->sign(key->data, (char *)sigdata,
6268 sigdata_len, &sigblob_len);
6269 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6270 sigblob, sigblob_len);
6275 ssh2_pkt_send(ssh, s->pktout);
6276 s->type = AUTH_TYPE_PUBLICKEY;
6277 key->alg->freekey(key->data);
6279 } else if (s->method == AUTH_PASSWORD) {
6281 * We send the password packet lumped tightly together with
6282 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6283 * string long enough to make the total length of the two
6284 * packets constant. This should ensure that a passive
6285 * listener doing traffic analyis can't work out the length
6288 * For this to work, we need an assumption about the
6289 * maximum length of the password packet. I think 256 is
6290 * pretty conservative. Anyone using a password longer than
6291 * that probably doesn't have much to worry about from
6292 * people who find out how long their password is!
6294 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6295 ssh2_pkt_addstring(s->pktout, s->username);
6296 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6297 ssh2_pkt_addstring(s->pktout, "password");
6298 ssh2_pkt_addbool(s->pktout, FALSE);
6299 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6300 ssh2_pkt_addstring(s->pktout, s->password);
6301 memset(s->password, 0, sizeof(s->password));
6302 end_log_omission(ssh, s->pktout);
6303 ssh2_pkt_defer(ssh, s->pktout);
6305 * We'll include a string that's an exact multiple of the
6306 * cipher block size. If the cipher is NULL for some
6307 * reason, we don't do this trick at all because we gain
6310 if (ssh->cscipher) {
6313 stringlen = (256 - ssh->deferred_len);
6314 stringlen += ssh->cscipher->blksize - 1;
6315 stringlen -= (stringlen % ssh->cscipher->blksize);
6318 * Temporarily disable actual compression,
6319 * so we can guarantee to get this string
6320 * exactly the length we want it. The
6321 * compression-disabling routine should
6322 * return an integer indicating how many
6323 * bytes we should adjust our string length
6327 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6329 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6330 ssh2_pkt_addstring_start(s->pktout);
6331 for (i = 0; i < stringlen; i++) {
6332 char c = (char) random_byte();
6333 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6335 ssh2_pkt_defer(ssh, s->pktout);
6337 ssh_pkt_defersend(ssh);
6338 logevent("Sent password");
6339 s->type = AUTH_TYPE_PASSWORD;
6340 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6341 if (s->curr_prompt == 0) {
6342 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6343 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6345 if (s->need_pw) { /* only add pw if we just got one! */
6346 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6347 ssh2_pkt_addstring(s->pktout, s->password);
6348 memset(s->password, 0, sizeof(s->password));
6349 end_log_omission(ssh, s->pktout);
6352 if (s->curr_prompt >= s->num_prompts) {
6353 ssh2_pkt_send(ssh, s->pktout);
6356 * If there are prompts remaining, we set
6357 * `gotit' so that we won't attempt to get
6358 * another packet. Then we go back round the
6359 * loop and will end up retrieving another
6360 * prompt out of the existing packet. Funky or
6365 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6367 c_write_str(ssh, "No supported authentication methods"
6368 " left to try!\r\n");
6369 logevent("No supported authentications offered."
6371 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6372 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6373 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6374 " methods available");
6375 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6376 ssh2_pkt_send_noqueue(ssh, s->pktout);
6377 ssh_closing((Plug)ssh, NULL, 0, 0);
6381 } while (!s->we_are_in);
6384 * Now we're authenticated for the connection protocol. The
6385 * connection protocol will automatically have started at this
6386 * point; there's no need to send SERVICE_REQUEST.
6389 ssh->channels = newtree234(ssh_channelcmp);
6392 * Set up handlers for some connection protocol messages, so we
6393 * don't have to handle them repeatedly in this coroutine.
6395 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6396 ssh2_msg_channel_window_adjust;
6397 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6398 ssh2_msg_global_request;
6401 * Create the main session channel.
6403 if (!ssh->cfg.ssh_no_shell) {
6404 ssh->mainchan = snew(struct ssh_channel);
6405 ssh->mainchan->ssh = ssh;
6406 ssh->mainchan->localid = alloc_channel_id(ssh);
6407 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6408 ssh2_pkt_addstring(s->pktout, "session");
6409 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6410 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6411 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6412 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6413 ssh2_pkt_send(ssh, s->pktout);
6414 crWaitUntilV(pktin);
6415 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6416 bombout(("Server refused to open a session"));
6418 /* FIXME: error data comes back in FAILURE packet */
6420 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6421 bombout(("Server's channel confirmation cited wrong channel"));
6424 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6425 ssh->mainchan->type = CHAN_MAINSESSION;
6426 ssh->mainchan->closes = 0;
6427 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6428 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6429 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6430 add234(ssh->channels, ssh->mainchan);
6431 update_specials_menu(ssh->frontend);
6432 logevent("Opened channel for session");
6434 ssh->mainchan = NULL;
6437 * Now we have a channel, make dispatch table entries for
6438 * general channel-based messages.
6440 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6441 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6442 ssh2_msg_channel_data;
6443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6444 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6445 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6446 ssh2_msg_channel_open_confirmation;
6447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6448 ssh2_msg_channel_open_failure;
6449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6450 ssh2_msg_channel_request;
6451 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6452 ssh2_msg_channel_open;
6455 * Potentially enable X11 forwarding.
6457 if (ssh->mainchan && ssh->cfg.x11_forward) {
6458 char proto[20], data[64];
6459 logevent("Requesting X11 forwarding");
6460 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6461 data, sizeof(data), ssh->cfg.x11_auth);
6462 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6463 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6464 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6465 ssh2_pkt_addstring(s->pktout, "x11-req");
6466 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6467 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6468 ssh2_pkt_addstring(s->pktout, proto);
6469 ssh2_pkt_addstring(s->pktout, data);
6470 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6471 ssh2_pkt_send(ssh, s->pktout);
6473 crWaitUntilV(pktin);
6475 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6476 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6477 bombout(("Unexpected response to X11 forwarding request:"
6478 " packet type %d", pktin->type));
6481 logevent("X11 forwarding refused");
6483 logevent("X11 forwarding enabled");
6484 ssh->X11_fwd_enabled = TRUE;
6489 * Enable port forwardings.
6494 int sport,dport,sserv,dserv;
6495 char sports[256], dports[256], saddr[256], host[256];
6497 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
6498 /* Add port forwardings. */
6499 ssh->portfwd_strptr = ssh->cfg.portfwd;
6500 while (*ssh->portfwd_strptr) {
6501 type = *ssh->portfwd_strptr++;
6504 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6505 if (*ssh->portfwd_strptr == ':') {
6507 * We've seen a colon in the middle of the
6508 * source port number. This means that
6509 * everything we've seen until now is the
6510 * source _address_, so we'll move it into
6511 * saddr and start sports from the beginning
6514 ssh->portfwd_strptr++;
6516 strcpy(saddr, sports);
6519 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6523 if (*ssh->portfwd_strptr == '\t')
6524 ssh->portfwd_strptr++;
6526 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6527 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6530 if (*ssh->portfwd_strptr == ':')
6531 ssh->portfwd_strptr++;
6533 while (*ssh->portfwd_strptr) {
6534 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6537 ssh->portfwd_strptr++;
6538 dport = atoi(dports);
6542 dport = net_service_lookup(dports);
6544 logeventf(ssh, "Service lookup failed for destination"
6545 " port \"%s\"", dports);
6549 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
6551 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
6553 sport = atoi(sports);
6557 sport = net_service_lookup(sports);
6559 logeventf(ssh, "Service lookup failed for source"
6560 " port \"%s\"", sports);
6563 if (sport && dport) {
6564 /* Set up a description of the source port. */
6565 static char *sportdesc;
6566 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
6567 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6568 (int)(*saddr?1:0), ":",
6569 (int)(sserv ? strlen(sports) : 0), sports,
6570 sserv, "(", sport, sserv, ")");
6572 /* Verbose description of the destination port */
6573 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6575 (int)(dserv ? strlen(dports) : 0), dports,
6576 dserv, "(", dport, dserv, ")");
6577 const char *err = pfd_addforward(host, dport,
6578 *saddr ? saddr : NULL,
6579 sport, ssh, &ssh->cfg);
6581 logeventf(ssh, "Local port %s forward to %s"
6582 " failed: %s", sportdesc, dportdesc, err);
6584 logeventf(ssh, "Local port %s forwarding to %s",
6585 sportdesc, dportdesc);
6588 } else if (type == 'D') {
6589 const char *err = pfd_addforward(NULL, -1,
6590 *saddr ? saddr : NULL,
6591 sport, ssh, &ssh->cfg);
6593 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6594 " setup failed: %s", sportdesc, err);
6596 logeventf(ssh, "Local port %s doing SOCKS"
6597 " dynamic forwarding", sportdesc);
6600 struct ssh_rportfwd *pf;
6601 pf = snew(struct ssh_rportfwd);
6602 strcpy(pf->dhost, host);
6605 if (add234(ssh->rportfwds, pf) != pf) {
6606 logeventf(ssh, "Duplicate remote port forwarding"
6607 " to %s:%d", host, dport);
6610 logeventf(ssh, "Requesting remote port %s"
6611 " forward to %s:%.*s%.*s%d%.*s",
6614 (int)(dserv ? strlen(dports) : 0), dports,
6615 dserv, "(", dport, dserv, ")");
6616 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6617 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6618 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
6620 ssh2_pkt_addstring(s->pktout, saddr);
6621 } else if (ssh->cfg.rport_acceptall) {
6622 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
6624 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
6626 ssh2_pkt_adduint32(s->pktout, sport);
6627 ssh2_pkt_send(ssh, s->pktout);
6629 crWaitUntilV(pktin);
6631 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6632 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6633 bombout(("Unexpected response to port "
6634 "forwarding request: packet type %d",
6638 logevent("Server refused this port forwarding");
6640 logevent("Remote port forwarding enabled");
6650 * Potentially enable agent forwarding.
6652 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6653 logevent("Requesting OpenSSH-style agent forwarding");
6654 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6655 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6656 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6657 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6658 ssh2_pkt_send(ssh, s->pktout);
6660 crWaitUntilV(pktin);
6662 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6663 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6664 bombout(("Unexpected response to agent forwarding request:"
6665 " packet type %d", pktin->type));
6668 logevent("Agent forwarding refused");
6670 logevent("Agent forwarding enabled");
6671 ssh->agentfwd_enabled = TRUE;
6676 * Now allocate a pty for the session.
6678 if (ssh->mainchan && !ssh->cfg.nopty) {
6679 /* Unpick the terminal-speed string. */
6680 /* XXX perhaps we should allow no speeds to be sent. */
6681 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6682 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6683 /* Build the pty request. */
6684 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6685 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6686 ssh2_pkt_addstring(s->pktout, "pty-req");
6687 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6688 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6689 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6690 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6691 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6692 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6693 ssh2_pkt_addstring_start(s->pktout);
6694 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6695 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6696 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6697 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6698 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6699 ssh2_pkt_send(ssh, s->pktout);
6700 ssh->state = SSH_STATE_INTERMED;
6702 crWaitUntilV(pktin);
6704 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6705 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6706 bombout(("Unexpected response to pty request:"
6707 " packet type %d", pktin->type));
6710 c_write_str(ssh, "Server refused to allocate pty\r\n");
6711 ssh->editing = ssh->echoing = 1;
6713 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6714 ssh->ospeed, ssh->ispeed);
6717 ssh->editing = ssh->echoing = 1;
6721 * Send environment variables.
6723 * Simplest thing here is to send all the requests at once, and
6724 * then wait for a whole bunch of successes or failures.
6726 if (ssh->mainchan && *ssh->cfg.environmt) {
6727 char *e = ssh->cfg.environmt;
6728 char *var, *varend, *val;
6734 while (*e && *e != '\t') e++;
6736 if (*e == '\t') e++;
6741 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6742 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6743 ssh2_pkt_addstring(s->pktout, "env");
6744 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6745 ssh2_pkt_addstring_start(s->pktout);
6746 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6747 ssh2_pkt_addstring(s->pktout, val);
6748 ssh2_pkt_send(ssh, s->pktout);
6753 logeventf(ssh, "Sent %d environment variables", s->num_env);
6756 s->env_left = s->num_env;
6758 while (s->env_left > 0) {
6759 crWaitUntilV(pktin);
6761 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6762 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6763 bombout(("Unexpected response to environment request:"
6764 " packet type %d", pktin->type));
6774 if (s->env_ok == s->num_env) {
6775 logevent("All environment variables successfully set");
6776 } else if (s->env_ok == 0) {
6777 logevent("All environment variables refused");
6778 c_write_str(ssh, "Server refused to set environment variables\r\n");
6780 logeventf(ssh, "%d environment variables refused",
6781 s->num_env - s->env_ok);
6782 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6787 * Start a shell or a remote command. We may have to attempt
6788 * this twice if the config data has provided a second choice
6791 if (ssh->mainchan) while (1) {
6795 if (ssh->fallback_cmd) {
6796 subsys = ssh->cfg.ssh_subsys2;
6797 cmd = ssh->cfg.remote_cmd_ptr2;
6799 subsys = ssh->cfg.ssh_subsys;
6800 cmd = ssh->cfg.remote_cmd_ptr;
6803 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6804 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6806 ssh2_pkt_addstring(s->pktout, "subsystem");
6807 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6808 ssh2_pkt_addstring(s->pktout, cmd);
6810 ssh2_pkt_addstring(s->pktout, "exec");
6811 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6812 ssh2_pkt_addstring(s->pktout, cmd);
6814 ssh2_pkt_addstring(s->pktout, "shell");
6815 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6817 ssh2_pkt_send(ssh, s->pktout);
6819 crWaitUntilV(pktin);
6821 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6822 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6823 bombout(("Unexpected response to shell/command request:"
6824 " packet type %d", pktin->type));
6828 * We failed to start the command. If this is the
6829 * fallback command, we really are finished; if it's
6830 * not, and if the fallback command exists, try falling
6831 * back to it before complaining.
6833 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6834 logevent("Primary command failed; attempting fallback");
6835 ssh->fallback_cmd = TRUE;
6838 bombout(("Server refused to start a shell/command"));
6841 logevent("Started a shell/command");
6846 ssh->state = SSH_STATE_SESSION;
6847 if (ssh->size_needed)
6848 ssh_size(ssh, ssh->term_width, ssh->term_height);
6849 if (ssh->eof_needed)
6850 ssh_special(ssh, TS_EOF);
6856 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6861 s->try_send = FALSE;
6865 * _All_ the connection-layer packets we expect to
6866 * receive are now handled by the dispatch table.
6867 * Anything that reaches here must be bogus.
6870 bombout(("Strange packet received: type %d", pktin->type));
6872 } else if (ssh->mainchan) {
6874 * We have spare data. Add it to the channel buffer.
6876 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6881 struct ssh_channel *c;
6883 * Try to send data on all channels if we can.
6885 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6888 continue; /* don't send on closing channels */
6889 bufsize = ssh2_try_send(c);
6892 case CHAN_MAINSESSION:
6893 /* stdin need not receive an unthrottle
6894 * notification since it will be polled */
6897 x11_unthrottle(c->u.x11.s);
6900 /* agent sockets are request/response and need no
6901 * buffer management */
6904 pfd_unthrottle(c->u.pfd.s);
6916 * Handlers for SSH2 messages that might arrive at any moment.
6918 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6920 /* log reason code in disconnect message */
6922 int nowlen, reason, msglen;
6924 reason = ssh_pkt_getuint32(pktin);
6925 ssh_pkt_getstring(pktin, &msg, &msglen);
6927 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6928 buf = dupprintf("Received disconnect message (%s)",
6929 ssh2_disconnect_reasons[reason]);
6931 buf = dupprintf("Received disconnect message (unknown"
6932 " type %d)", reason);
6936 buf = dupprintf("Disconnection message text: %n%.*s",
6937 &nowlen, msglen, msg);
6939 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6941 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6942 ssh2_disconnect_reasons[reason] : "unknown",
6947 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6949 /* log the debug message */
6954 /* XXX maybe we should actually take notice of this */
6955 always_display = ssh2_pkt_getbool(pktin);
6956 ssh_pkt_getstring(pktin, &msg, &msglen);
6958 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6963 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6965 struct Packet *pktout;
6966 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6967 ssh2_pkt_adduint32(pktout, pktin->sequence);
6969 * UNIMPLEMENTED messages MUST appear in the same order as the
6970 * messages they respond to. Hence, never queue them.
6972 ssh2_pkt_send_noqueue(ssh, pktout);
6976 * Handle the top-level SSH2 protocol.
6978 static void ssh2_protocol_setup(Ssh ssh)
6983 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6985 for (i = 0; i < 256; i++)
6986 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6989 * Any message we actually understand, we set to NULL so that
6990 * the coroutines will get it.
6992 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6993 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6994 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6995 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6996 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6997 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6998 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6999 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7000 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7001 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7002 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7003 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7004 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7005 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7006 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7007 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7008 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7009 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7010 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7011 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7012 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7013 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7014 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7027 * These special message types we install handlers for.
7029 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7030 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7031 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7034 static void ssh2_timer(void *ctx, long now)
7038 if (!ssh->kex_in_progress &&
7039 now - ssh->next_rekey >= 0) {
7040 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7045 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7046 struct Packet *pktin)
7048 if (ssh->state == SSH_STATE_CLOSED)
7052 ssh->incoming_data_size += pktin->encrypted_len;
7053 if (!ssh->kex_in_progress &&
7054 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7055 do_ssh2_transport(ssh, "Initiating key re-exchange "
7056 "(too much data received)", -1, NULL);
7059 if (pktin && ssh->packet_dispatch[pktin->type]) {
7060 ssh->packet_dispatch[pktin->type](ssh, pktin);
7064 if (!ssh->protocol_initial_phase_done ||
7065 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7066 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7067 !ssh->protocol_initial_phase_done) {
7068 ssh->protocol_initial_phase_done = TRUE;
7070 * Allow authconn to initialise itself.
7072 do_ssh2_authconn(ssh, NULL, 0, NULL);
7075 do_ssh2_authconn(ssh, in, inlen, pktin);
7080 * Called to set up the connection.
7082 * Returns an error message, or NULL on success.
7084 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7086 char *host, int port, char **realhost, int nodelay,
7092 ssh = snew(struct ssh_tag);
7093 ssh->cfg = *cfg; /* STRUCTURE COPY */
7094 ssh->version = 0; /* when not ready yet */
7097 ssh->v1_cipher_ctx = NULL;
7098 ssh->crcda_ctx = NULL;
7099 ssh->cscipher = NULL;
7100 ssh->cs_cipher_ctx = NULL;
7101 ssh->sccipher = NULL;
7102 ssh->sc_cipher_ctx = NULL;
7104 ssh->cs_mac_ctx = NULL;
7106 ssh->sc_mac_ctx = NULL;
7108 ssh->cs_comp_ctx = NULL;
7110 ssh->sc_comp_ctx = NULL;
7112 ssh->kex_ctx = NULL;
7113 ssh->hostkey = NULL;
7115 ssh->state = SSH_STATE_PREPACKET;
7116 ssh->size_needed = FALSE;
7117 ssh->eof_needed = FALSE;
7120 ssh->deferred_send_data = NULL;
7121 ssh->deferred_len = 0;
7122 ssh->deferred_size = 0;
7123 ssh->fallback_cmd = 0;
7125 ssh->x11auth = NULL;
7126 ssh->v1_compressing = FALSE;
7127 ssh->v2_outgoing_sequence = 0;
7128 ssh->ssh1_rdpkt_crstate = 0;
7129 ssh->ssh2_rdpkt_crstate = 0;
7130 ssh->do_ssh_init_crstate = 0;
7131 ssh->ssh_gotdata_crstate = 0;
7132 ssh->do_ssh1_connection_crstate = 0;
7133 ssh->do_ssh1_login_crstate = 0;
7134 ssh->do_ssh2_transport_crstate = 0;
7135 ssh->do_ssh2_authconn_crstate = 0;
7136 ssh->do_ssh_init_state = NULL;
7137 ssh->do_ssh1_login_state = NULL;
7138 ssh->do_ssh2_transport_state = NULL;
7139 ssh->do_ssh2_authconn_state = NULL;
7140 ssh->mainchan = NULL;
7141 ssh->throttled_all = 0;
7142 ssh->v1_stdout_throttling = 0;
7144 ssh->queuelen = ssh->queuesize = 0;
7145 ssh->queueing = FALSE;
7147 *backend_handle = ssh;
7150 if (crypto_startup() == 0)
7151 return "Microsoft high encryption pack not installed!";
7154 ssh->frontend = frontend_handle;
7155 ssh->term_width = ssh->cfg.width;
7156 ssh->term_height = ssh->cfg.height;
7158 ssh->channels = NULL;
7159 ssh->rportfwds = NULL;
7164 ssh->v1_throttle_count = 0;
7165 ssh->overall_bufsize = 0;
7166 ssh->fallback_cmd = 0;
7168 ssh->protocol = NULL;
7170 ssh->protocol_initial_phase_done = FALSE;
7174 ssh->incoming_data_size = ssh->outgoing_data_size =
7175 ssh->deferred_data_size = 0L;
7176 ssh->kex_in_progress = FALSE;
7178 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7187 static void ssh_free(void *handle)
7189 Ssh ssh = (Ssh) handle;
7190 struct ssh_channel *c;
7191 struct ssh_rportfwd *pf;
7193 if (ssh->v1_cipher_ctx)
7194 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7195 if (ssh->cs_cipher_ctx)
7196 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7197 if (ssh->sc_cipher_ctx)
7198 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7199 if (ssh->cs_mac_ctx)
7200 ssh->csmac->free_context(ssh->cs_mac_ctx);
7201 if (ssh->sc_mac_ctx)
7202 ssh->scmac->free_context(ssh->sc_mac_ctx);
7203 if (ssh->cs_comp_ctx) {
7205 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7207 zlib_compress_cleanup(ssh->cs_comp_ctx);
7209 if (ssh->sc_comp_ctx) {
7211 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7213 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7216 dh_cleanup(ssh->kex_ctx);
7217 sfree(ssh->savedhost);
7219 while (ssh->queuelen-- > 0)
7220 ssh_free_packet(ssh->queue[ssh->queuelen]);
7223 if (ssh->channels) {
7224 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7227 if (c->u.x11.s != NULL)
7228 x11_close(c->u.x11.s);
7231 if (c->u.pfd.s != NULL)
7232 pfd_close(c->u.pfd.s);
7237 freetree234(ssh->channels);
7238 ssh->channels = NULL;
7241 if (ssh->rportfwds) {
7242 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7244 freetree234(ssh->rportfwds);
7245 ssh->rportfwds = NULL;
7247 sfree(ssh->deferred_send_data);
7249 x11_free_auth(ssh->x11auth);
7250 sfree(ssh->do_ssh_init_state);
7251 sfree(ssh->do_ssh1_login_state);
7252 sfree(ssh->do_ssh2_transport_state);
7253 sfree(ssh->do_ssh2_authconn_state);
7254 if (ssh->crcda_ctx) {
7255 crcda_free_context(ssh->crcda_ctx);
7256 ssh->crcda_ctx = NULL;
7260 expire_timer_context(ssh);
7262 pinger_free(ssh->pinger);
7269 * Reconfigure the SSH backend.
7271 * Currently, this function does nothing very useful. In future,
7272 * however, we could do some handy things with it. For example, we
7273 * could make the port forwarding configurer active in the Change
7274 * Settings box, and this routine could close down existing
7275 * forwardings and open up new ones in response to changes.
7277 static void ssh_reconfig(void *handle, Config *cfg)
7279 Ssh ssh = (Ssh) handle;
7280 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7281 ssh->cfg = *cfg; /* STRUCTURE COPY */
7285 * Called to send data down the Telnet connection.
7287 static int ssh_send(void *handle, char *buf, int len)
7289 Ssh ssh = (Ssh) handle;
7291 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7294 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7296 return ssh_sendbuffer(ssh);
7300 * Called to query the current amount of buffered stdin data.
7302 static int ssh_sendbuffer(void *handle)
7304 Ssh ssh = (Ssh) handle;
7307 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7311 * If the SSH socket itself has backed up, add the total backup
7312 * size on that to any individual buffer on the stdin channel.
7315 if (ssh->throttled_all)
7316 override_value = ssh->overall_bufsize;
7318 if (ssh->version == 1) {
7319 return override_value;
7320 } else if (ssh->version == 2) {
7321 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7322 return override_value;
7324 return (override_value +
7325 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7332 * Called to set the size of the window from SSH's POV.
7334 static void ssh_size(void *handle, int width, int height)
7336 Ssh ssh = (Ssh) handle;
7337 struct Packet *pktout;
7339 ssh->term_width = width;
7340 ssh->term_height = height;
7342 switch (ssh->state) {
7343 case SSH_STATE_BEFORE_SIZE:
7344 case SSH_STATE_PREPACKET:
7345 case SSH_STATE_CLOSED:
7346 break; /* do nothing */
7347 case SSH_STATE_INTERMED:
7348 ssh->size_needed = TRUE; /* buffer for later */
7350 case SSH_STATE_SESSION:
7351 if (!ssh->cfg.nopty) {
7352 if (ssh->version == 1) {
7353 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7354 PKT_INT, ssh->term_height,
7355 PKT_INT, ssh->term_width,
7356 PKT_INT, 0, PKT_INT, 0, PKT_END);
7357 } else if (ssh->mainchan) {
7358 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7359 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7360 ssh2_pkt_addstring(pktout, "window-change");
7361 ssh2_pkt_addbool(pktout, 0);
7362 ssh2_pkt_adduint32(pktout, ssh->term_width);
7363 ssh2_pkt_adduint32(pktout, ssh->term_height);
7364 ssh2_pkt_adduint32(pktout, 0);
7365 ssh2_pkt_adduint32(pktout, 0);
7366 ssh2_pkt_send(ssh, pktout);
7374 * Return a list of the special codes that make sense in this
7377 static const struct telnet_special *ssh_get_specials(void *handle)
7379 static const struct telnet_special ignore_special[] = {
7380 {"IGNORE message", TS_NOP},
7381 {"Repeat key exchange", TS_REKEY},
7383 static const struct telnet_special ssh2_session_specials[] = {
7386 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7387 * They include all the ISO C signals, but are a subset of the POSIX
7388 * required signals. */
7389 {"SIGINT (Interrupt)", TS_SIGINT},
7390 {"SIGTERM (Terminate)", TS_SIGTERM},
7391 {"SIGKILL (Kill)", TS_SIGKILL},
7392 {"SIGQUIT (Quit)", TS_SIGQUIT},
7393 {"SIGHUP (Hangup)", TS_SIGHUP},
7394 {"More signals", TS_SUBMENU},
7395 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7396 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7397 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7398 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7401 static const struct telnet_special specials_end[] = {
7404 static struct telnet_special ssh_specials[lenof(ignore_special) +
7405 lenof(ssh2_session_specials) +
7406 lenof(specials_end)];
7407 Ssh ssh = (Ssh) handle;
7409 #define ADD_SPECIALS(name) \
7411 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7412 memcpy(&ssh_specials[i], name, sizeof name); \
7416 if (ssh->version == 1) {
7417 /* Don't bother offering IGNORE if we've decided the remote
7418 * won't cope with it, since we wouldn't bother sending it if
7420 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7421 ADD_SPECIALS(ignore_special);
7422 } else if (ssh->version == 2) {
7423 ADD_SPECIALS(ignore_special);
7425 ADD_SPECIALS(ssh2_session_specials);
7426 } /* else we're not ready yet */
7429 ADD_SPECIALS(specials_end);
7430 return ssh_specials;
7438 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7439 * can send an EOF and collect resulting output (e.g. `plink
7442 static void ssh_special(void *handle, Telnet_Special code)
7444 Ssh ssh = (Ssh) handle;
7445 struct Packet *pktout;
7447 if (code == TS_EOF) {
7448 if (ssh->state != SSH_STATE_SESSION) {
7450 * Buffer the EOF in case we are pre-SESSION, so we can
7451 * send it as soon as we reach SESSION.
7454 ssh->eof_needed = TRUE;
7457 if (ssh->version == 1) {
7458 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7459 } else if (ssh->mainchan) {
7460 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7461 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7462 ssh2_pkt_send(ssh, pktout);
7464 logevent("Sent EOF message");
7465 } else if (code == TS_PING || code == TS_NOP) {
7466 if (ssh->state == SSH_STATE_CLOSED
7467 || ssh->state == SSH_STATE_PREPACKET) return;
7468 if (ssh->version == 1) {
7469 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7470 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7472 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7473 ssh2_pkt_addstring_start(pktout);
7474 ssh2_pkt_send_noqueue(ssh, pktout);
7476 } else if (code == TS_REKEY) {
7477 if (!ssh->kex_in_progress && ssh->version == 2) {
7478 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7479 " user request", -1, NULL);
7481 } else if (code == TS_BRK) {
7482 if (ssh->state == SSH_STATE_CLOSED
7483 || ssh->state == SSH_STATE_PREPACKET) return;
7484 if (ssh->version == 1) {
7485 logevent("Unable to send BREAK signal in SSH1");
7486 } else if (ssh->mainchan) {
7487 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7488 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7489 ssh2_pkt_addstring(pktout, "break");
7490 ssh2_pkt_addbool(pktout, 0);
7491 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7492 ssh2_pkt_send(ssh, pktout);
7495 /* Is is a POSIX signal? */
7496 char *signame = NULL;
7497 if (code == TS_SIGABRT) signame = "ABRT";
7498 if (code == TS_SIGALRM) signame = "ALRM";
7499 if (code == TS_SIGFPE) signame = "FPE";
7500 if (code == TS_SIGHUP) signame = "HUP";
7501 if (code == TS_SIGILL) signame = "ILL";
7502 if (code == TS_SIGINT) signame = "INT";
7503 if (code == TS_SIGKILL) signame = "KILL";
7504 if (code == TS_SIGPIPE) signame = "PIPE";
7505 if (code == TS_SIGQUIT) signame = "QUIT";
7506 if (code == TS_SIGSEGV) signame = "SEGV";
7507 if (code == TS_SIGTERM) signame = "TERM";
7508 if (code == TS_SIGUSR1) signame = "USR1";
7509 if (code == TS_SIGUSR2) signame = "USR2";
7510 /* The SSH-2 protocol does in principle support arbitrary named
7511 * signals, including signame@domain, but we don't support those. */
7513 /* It's a signal. */
7514 if (ssh->version == 2 && ssh->mainchan) {
7515 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7516 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7517 ssh2_pkt_addstring(pktout, "signal");
7518 ssh2_pkt_addbool(pktout, 0);
7519 ssh2_pkt_addstring(pktout, signame);
7520 ssh2_pkt_send(ssh, pktout);
7521 logeventf(ssh, "Sent signal SIG%s", signame);
7524 /* Never heard of it. Do nothing */
7529 void *new_sock_channel(void *handle, Socket s)
7531 Ssh ssh = (Ssh) handle;
7532 struct ssh_channel *c;
7533 c = snew(struct ssh_channel);
7537 c->remoteid = -1; /* to be set when open confirmed */
7538 c->localid = alloc_channel_id(ssh);
7540 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7542 bufchain_init(&c->v.v2.outbuffer);
7543 add234(ssh->channels, c);
7549 * This is called when stdout/stderr (the entity to which
7550 * from_backend sends data) manages to clear some backlog.
7552 static void ssh_unthrottle(void *handle, int bufsize)
7554 Ssh ssh = (Ssh) handle;
7555 if (ssh->version == 1) {
7556 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7557 ssh->v1_stdout_throttling = 0;
7558 ssh1_throttle(ssh, -1);
7561 if (ssh->mainchan && ssh->mainchan->closes == 0)
7562 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7566 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7568 struct ssh_channel *c = (struct ssh_channel *)channel;
7570 struct Packet *pktout;
7572 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7574 if (ssh->version == 1) {
7575 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7576 PKT_INT, c->localid,
7579 //PKT_STR, <org:orgport>,
7582 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7583 ssh2_pkt_addstring(pktout, "direct-tcpip");
7584 ssh2_pkt_adduint32(pktout, c->localid);
7585 c->v.v2.locwindow = OUR_V2_WINSIZE;
7586 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7587 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7588 ssh2_pkt_addstring(pktout, hostname);
7589 ssh2_pkt_adduint32(pktout, port);
7591 * We make up values for the originator data; partly it's
7592 * too much hassle to keep track, and partly I'm not
7593 * convinced the server should be told details like that
7594 * about my local network configuration.
7596 ssh2_pkt_addstring(pktout, "client-side-connection");
7597 ssh2_pkt_adduint32(pktout, 0);
7598 ssh2_pkt_send(ssh, pktout);
7602 static Socket ssh_socket(void *handle)
7604 Ssh ssh = (Ssh) handle;
7608 static int ssh_sendok(void *handle)
7610 Ssh ssh = (Ssh) handle;
7611 return ssh->send_ok;
7614 static int ssh_ldisc(void *handle, int option)
7616 Ssh ssh = (Ssh) handle;
7617 if (option == LD_ECHO)
7618 return ssh->echoing;
7619 if (option == LD_EDIT)
7620 return ssh->editing;
7624 static void ssh_provide_ldisc(void *handle, void *ldisc)
7626 Ssh ssh = (Ssh) handle;
7630 static void ssh_provide_logctx(void *handle, void *logctx)
7632 Ssh ssh = (Ssh) handle;
7633 ssh->logctx = logctx;
7636 static int ssh_return_exitcode(void *handle)
7638 Ssh ssh = (Ssh) handle;
7642 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7646 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7647 * that fails. This variable is the means by which scp.c can reach
7648 * into the SSH code and find out which one it got.
7650 extern int ssh_fallback_cmd(void *handle)
7652 Ssh ssh = (Ssh) handle;
7653 return ssh->fallback_cmd;
7656 Backend ssh_backend = {
7666 ssh_return_exitcode,