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;
320 static void ssh2_pkt_init(Ssh, int pkt_type);
321 static void ssh2_pkt_addbool(Ssh, unsigned char value);
322 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
323 static void ssh2_pkt_addstring_start(Ssh);
324 static void ssh2_pkt_addstring_str(Ssh, char *data);
325 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
326 static void ssh2_pkt_addstring(Ssh, char *data);
327 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
328 static void ssh2_pkt_addmp(Ssh, Bignum b);
329 static int ssh2_pkt_construct(Ssh);
330 static void ssh2_pkt_send(Ssh);
331 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
332 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
335 * Buffer management constants. There are several of these for
336 * various different purposes:
338 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
339 * on a local data stream before we throttle the whole SSH
340 * connection (in SSH1 only). Throttling the whole connection is
341 * pretty drastic so we set this high in the hope it won't
344 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
345 * on the SSH connection itself before we defensively throttle
346 * _all_ local data streams. This is pretty drastic too (though
347 * thankfully unlikely in SSH2 since the window mechanism should
348 * ensure that the server never has any need to throttle its end
349 * of the connection), so we set this high as well.
351 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
355 #define SSH1_BUFFER_LIMIT 32768
356 #define SSH_MAX_BACKLOG 32768
357 #define OUR_V2_WINSIZE 16384
359 const static struct ssh_kex *kex_algs[] = {
360 &ssh_diffiehellman_gex,
364 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
366 static void *nullmac_make_context(void)
370 static void nullmac_free_context(void *handle)
373 static void nullmac_key(void *handle, unsigned char *key)
376 static void nullmac_generate(void *handle, unsigned char *blk, int len,
380 static int nullmac_verify(void *handle, unsigned char *blk, int len,
385 const static struct ssh_mac ssh_mac_none = {
386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
389 const static struct ssh_mac *macs[] = {
390 &ssh_sha1, &ssh_md5, &ssh_mac_none
392 const static struct ssh_mac *buggymacs[] = {
393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
396 static void *ssh_comp_none_init(void)
400 static void ssh_comp_none_cleanup(void *handle)
403 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
404 unsigned char **outblock, int *outlen)
408 static int ssh_comp_none_disable(void *handle)
412 const static struct ssh_compress ssh_comp_none = {
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
418 extern const struct ssh_compress ssh_zlib;
419 const static struct ssh_compress *compressions[] = {
420 &ssh_zlib, &ssh_comp_none
423 enum { /* channel types */
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
432 * 2-3-4 tree storing channels.
435 Ssh ssh; /* pointer back to main context */
436 unsigned remoteid, localid;
439 * In SSH1, this value contains four bits:
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 * A channel is completely finished with when all four bits are set.
450 struct ssh1_data_channel {
453 struct ssh2_data_channel {
455 unsigned remwindow, remmaxpkt;
460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
463 unsigned lensofar, totallen;
465 struct ssh_x11_channel {
468 struct ssh_pfd_channel {
475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
498 * Hence: in SSH 1 this structure stores host:port pairs we intend
499 * to allow connections to, and is indexed by those host:port
500 * pairs. In SSH 2 it stores a mapping from source port to
501 * destination host:port pair, and is indexed by source port.
503 struct ssh_rportfwd {
504 unsigned sport, dport;
517 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
518 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
519 static void ssh_size(void *handle, int width, int height);
520 static void ssh_special(void *handle, Telnet_Special);
521 static int ssh2_try_send(struct ssh_channel *c);
522 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
523 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
524 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
525 static int ssh_sendbuffer(void *handle);
526 static void ssh_do_close(Ssh ssh);
527 static unsigned long ssh_pkt_getuint32(Ssh ssh);
528 static int ssh2_pkt_getbool(Ssh ssh);
529 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length);
531 struct rdpkt1_state_tag {
532 long len, pad, biglen, to_read;
533 unsigned long realcrc, gotcrc;
539 struct rdpkt2_state_tag {
540 long len, pad, payload, packetlen, maclen;
543 unsigned long incoming_sequence;
547 const struct plug_function_table *fn;
548 /* the above field _must_ be first in the structure */
550 SHA_State exhash, exhashbase;
557 unsigned char session_key[32];
559 int v1_remote_protoflags;
560 int v1_local_protoflags;
561 int agentfwd_enabled;
564 const struct ssh_cipher *cipher;
567 const struct ssh2_cipher *cscipher, *sccipher;
568 void *cs_cipher_ctx, *sc_cipher_ctx;
569 const struct ssh_mac *csmac, *scmac;
570 void *cs_mac_ctx, *sc_mac_ctx;
571 const struct ssh_compress *cscomp, *sccomp;
572 void *cs_comp_ctx, *sc_comp_ctx;
573 const struct ssh_kex *kex;
574 const struct ssh_signkey *hostkey;
575 unsigned char v2_session_id[20];
581 int echoing, editing;
585 int ospeed, ispeed; /* temporaries */
586 int term_width, term_height;
588 tree234 *channels; /* indexed by local id */
589 struct ssh_channel *mainchan; /* primary session channel */
596 SSH_STATE_BEFORE_SIZE,
602 int size_needed, eof_needed;
605 struct Packet pktout;
606 unsigned char *deferred_send_data;
607 int deferred_len, deferred_size;
610 * State associated with packet logging
614 struct logblank_t *pktout_blanks;
617 * Gross hack: pscp will try to start SFTP but fall back to
618 * scp1 if that fails. This variable is the means by which
619 * scp.c can reach into the SSH code and find out which one it
625 * Used for username and password input.
627 char *userpass_input_buffer;
628 int userpass_input_buflen;
629 int userpass_input_bufpos;
630 int userpass_input_echo;
632 char *portfwd_strptr;
638 int v1_throttle_count;
641 int v1_stdout_throttling;
642 int v2_outgoing_sequence;
644 int ssh1_rdpkt_crstate;
645 int ssh2_rdpkt_crstate;
646 int do_ssh_init_crstate;
647 int ssh_gotdata_crstate;
648 int ssh1_protocol_crstate;
649 int do_ssh1_login_crstate;
650 int do_ssh2_transport_crstate;
651 int do_ssh2_authconn_crstate;
653 void *do_ssh_init_state;
654 void *do_ssh1_login_state;
655 void *do_ssh2_transport_state;
656 void *do_ssh2_authconn_state;
658 struct rdpkt1_state_tag rdpkt1_state;
659 struct rdpkt2_state_tag rdpkt2_state;
661 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
662 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
665 * We maintain a full _copy_ of a Config structure here, not
666 * merely a pointer to it. That way, when we're passed a new
667 * one for reconfiguration, we can check the differences and
668 * potentially reconfigure port forwardings etc in mid-session.
673 * Used to transfer data back from async agent callbacks.
675 void *agent_response;
676 int agent_response_len;
679 #define logevent(s) logevent(ssh->frontend, s)
681 /* logevent, only printf-formatted. */
682 static void logeventf(Ssh ssh, const char *fmt, ...)
688 buf = dupvprintf(fmt, ap);
694 #define bombout(msg) \
696 char *text = dupprintf msg; \
699 connection_fatal(ssh->frontend, "%s", text); \
703 /* Functions to leave bits out of the SSH packet log file. */
705 static void dont_log_password(Ssh ssh, int blanktype)
707 if (ssh->cfg.logomitpass)
708 ssh->pktout_logmode = blanktype;
711 static void dont_log_data(Ssh ssh, int blanktype)
713 if (ssh->cfg.logomitdata)
714 ssh->pktout_logmode = blanktype;
717 static void end_log_omission(Ssh ssh)
719 ssh->pktout_logmode = PKTLOG_EMIT;
722 static int ssh_channelcmp(void *av, void *bv)
724 struct ssh_channel *a = (struct ssh_channel *) av;
725 struct ssh_channel *b = (struct ssh_channel *) bv;
726 if (a->localid < b->localid)
728 if (a->localid > b->localid)
732 static int ssh_channelfind(void *av, void *bv)
734 unsigned *a = (unsigned *) av;
735 struct ssh_channel *b = (struct ssh_channel *) bv;
743 static int ssh_rportcmp_ssh1(void *av, void *bv)
745 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
746 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
748 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
749 return i < 0 ? -1 : +1;
750 if (a->dport > b->dport)
752 if (a->dport < b->dport)
757 static int ssh_rportcmp_ssh2(void *av, void *bv)
759 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
760 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
762 if (a->sport > b->sport)
764 if (a->sport < b->sport)
769 static int alloc_channel_id(Ssh ssh)
771 const unsigned CHANNEL_NUMBER_OFFSET = 256;
772 unsigned low, high, mid;
774 struct ssh_channel *c;
777 * First-fit allocation of channel numbers: always pick the
778 * lowest unused one. To do this, binary-search using the
779 * counted B-tree to find the largest channel ID which is in a
780 * contiguous sequence from the beginning. (Precisely
781 * everything in that sequence must have ID equal to its tree
782 * index plus CHANNEL_NUMBER_OFFSET.)
784 tsize = count234(ssh->channels);
788 while (high - low > 1) {
789 mid = (high + low) / 2;
790 c = index234(ssh->channels, mid);
791 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
792 low = mid; /* this one is fine */
794 high = mid; /* this one is past it */
797 * Now low points to either -1, or the tree index of the
798 * largest ID in the initial sequence.
801 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
802 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
804 return low + 1 + CHANNEL_NUMBER_OFFSET;
807 static void c_write(Ssh ssh, const char *buf, int len)
809 if ((flags & FLAG_STDERR)) {
811 for (i = 0; i < len; i++)
813 fputc(buf[i], stderr);
816 from_backend(ssh->frontend, 1, buf, len);
819 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
822 for (i = 0; i < len; i++) {
824 c_write(ssh, "\r\n", 2);
825 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
826 c_write(ssh, buf + i, 1);
830 static void c_write_str(Ssh ssh, const char *buf)
832 c_write(ssh, buf, strlen(buf));
836 * Collect incoming data in the incoming packet buffer.
837 * Decipher and verify the packet when it is completely read.
838 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
839 * Update the *data and *datalen variables.
840 * Return the additional nr of bytes needed, or 0 when
841 * a complete packet is available.
843 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
845 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
847 crBegin(ssh->ssh1_rdpkt_crstate);
852 ssh->pktin.length = 0;
854 for (st->i = st->len = 0; st->i < 4; st->i++) {
855 while ((*datalen) == 0)
857 st->len = (st->len << 8) + **data;
858 (*data)++, (*datalen)--;
861 st->pad = 8 - (st->len % 8);
862 st->biglen = st->len + st->pad;
863 ssh->pktin.length = st->len - 5;
865 if (st->biglen < 0) {
866 bombout(("Extremely large packet length from server suggests"
867 " data stream corruption"));
871 if (ssh->pktin.maxlen < st->biglen) {
872 ssh->pktin.maxlen = st->biglen;
873 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
877 st->to_read = st->biglen;
878 st->p = ssh->pktin.data;
879 while (st->to_read > 0) {
880 st->chunk = st->to_read;
881 while ((*datalen) == 0)
882 crReturn(st->to_read);
883 if (st->chunk > (*datalen))
884 st->chunk = (*datalen);
885 memcpy(st->p, *data, st->chunk);
887 *datalen -= st->chunk;
889 st->to_read -= st->chunk;
892 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
894 bombout(("Network attack (CRC compensation) detected!"));
899 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
901 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
902 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
903 if (st->gotcrc != st->realcrc) {
904 bombout(("Incorrect CRC received on packet"));
908 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
909 ssh->pktin.savedpos = 0;
911 if (ssh->v1_compressing) {
912 unsigned char *decompblk;
914 if (!zlib_decompress_block(ssh->sc_comp_ctx,
915 ssh->pktin.body - 1, ssh->pktin.length + 1,
916 &decompblk, &decomplen)) {
917 bombout(("Zlib decompression encountered invalid data"));
921 if (ssh->pktin.maxlen < st->pad + decomplen) {
922 ssh->pktin.maxlen = st->pad + decomplen;
923 ssh->pktin.data = sresize(ssh->pktin.data,
924 ssh->pktin.maxlen + APIEXTRA,
926 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
929 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
931 ssh->pktin.length = decomplen - 1;
934 ssh->pktin.type = ssh->pktin.body[-1];
937 * Log incoming packet, possibly omitting sensitive fields.
941 struct logblank_t blank;
942 if (ssh->cfg.logomitdata) {
943 int do_blank = FALSE, blank_prefix = 0;
944 /* "Session data" packets - omit the data field */
945 if ((ssh->pktin.type == SSH1_SMSG_STDOUT_DATA) ||
946 (ssh->pktin.type == SSH1_SMSG_STDERR_DATA)) {
947 do_blank = TRUE; blank_prefix = 0;
948 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
949 do_blank = TRUE; blank_prefix = 4;
952 blank.offset = blank_prefix;
953 blank.len = ssh->pktin.length;
954 blank.type = PKTLOG_OMIT;
958 log_packet(ssh->logctx,
959 PKT_INCOMING, ssh->pktin.type,
960 ssh1_pkt_type(ssh->pktin.type),
961 ssh->pktin.body, ssh->pktin.length,
965 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
966 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
967 ssh->pktin.type == SSH1_MSG_DEBUG ||
968 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
969 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
970 long stringlen = GET_32BIT(ssh->pktin.body);
971 if (stringlen + 4 != ssh->pktin.length) {
972 bombout(("Received data packet with bogus string length"));
977 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
981 ssh_pkt_getstring(ssh, &msg, &msglen);
982 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
987 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
992 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
993 /* log reason code in disconnect message */
997 ssh_pkt_getstring(ssh, &msg, &msglen);
999 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
1006 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1008 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1010 crBegin(ssh->ssh2_rdpkt_crstate);
1013 ssh->pktin.type = 0;
1014 ssh->pktin.length = 0;
1016 st->cipherblk = ssh->sccipher->blksize;
1019 if (st->cipherblk < 8)
1022 if (ssh->pktin.maxlen < st->cipherblk) {
1023 ssh->pktin.maxlen = st->cipherblk;
1024 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
1029 * Acquire and decrypt the first block of the packet. This will
1030 * contain the length and padding details.
1032 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1033 while ((*datalen) == 0)
1034 crReturn(st->cipherblk - st->i);
1035 ssh->pktin.data[st->i] = *(*data)++;
1040 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1041 ssh->pktin.data, st->cipherblk);
1044 * Now get the length and padding figures.
1046 st->len = GET_32BIT(ssh->pktin.data);
1047 st->pad = ssh->pktin.data[4];
1050 * _Completely_ silly lengths should be stomped on before they
1051 * do us any more damage.
1053 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1054 bombout(("Incoming packet was garbled on decryption"));
1059 * This enables us to deduce the payload length.
1061 st->payload = st->len - st->pad - 1;
1063 ssh->pktin.length = st->payload + 5;
1066 * So now we can work out the total packet length.
1068 st->packetlen = st->len + 4;
1069 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1072 * Adjust memory allocation if packet is too big.
1074 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1075 ssh->pktin.maxlen = st->packetlen + st->maclen;
1076 ssh->pktin.data = sresize(ssh->pktin.data,
1077 ssh->pktin.maxlen + APIEXTRA,
1082 * Read and decrypt the remainder of the packet.
1084 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1086 while ((*datalen) == 0)
1087 crReturn(st->packetlen + st->maclen - st->i);
1088 ssh->pktin.data[st->i] = *(*data)++;
1091 /* Decrypt everything _except_ the MAC. */
1093 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1094 ssh->pktin.data + st->cipherblk,
1095 st->packetlen - st->cipherblk);
1101 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1102 st->incoming_sequence)) {
1103 bombout(("Incorrect MAC received on packet"));
1106 st->incoming_sequence++; /* whether or not we MACed */
1109 * Decompress packet payload.
1112 unsigned char *newpayload;
1115 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1116 ssh->pktin.data + 5, ssh->pktin.length - 5,
1117 &newpayload, &newlen)) {
1118 if (ssh->pktin.maxlen < newlen + 5) {
1119 ssh->pktin.maxlen = newlen + 5;
1120 ssh->pktin.data = sresize(ssh->pktin.data,
1121 ssh->pktin.maxlen + APIEXTRA,
1124 ssh->pktin.length = 5 + newlen;
1125 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1130 ssh->pktin.savedpos = 6;
1131 ssh->pktin.body = ssh->pktin.data;
1132 ssh->pktin.type = ssh->pktin.data[5];
1135 * Log incoming packet, possibly omitting sensitive fields.
1139 struct logblank_t blank;
1140 if (ssh->cfg.logomitdata) {
1141 int do_blank = FALSE, blank_prefix = 0;
1142 /* "Session data" packets - omit the data field */
1143 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA) {
1144 do_blank = TRUE; blank_prefix = 4;
1145 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1146 do_blank = TRUE; blank_prefix = 8;
1149 blank.offset = blank_prefix;
1150 blank.len = (ssh->pktin.length-6) - blank_prefix;
1151 blank.type = PKTLOG_OMIT;
1155 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1156 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1157 ssh->pktin.data+6, ssh->pktin.length-6,
1161 switch (ssh->pktin.type) {
1163 * These packets we must handle instantly.
1165 case SSH2_MSG_DISCONNECT:
1167 /* log reason code in disconnect message */
1169 int nowlen, reason, msglen;
1171 reason = ssh_pkt_getuint32(ssh);
1172 ssh_pkt_getstring(ssh, &msg, &msglen);
1174 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1175 buf = dupprintf("Received disconnect message (%s)",
1176 ssh2_disconnect_reasons[reason]);
1178 buf = dupprintf("Received disconnect message (unknown"
1179 " type %d)", reason);
1183 buf = dupprintf("Disconnection message text: %n%.*s",
1184 &nowlen, msglen, msg);
1186 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1188 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1189 ssh2_disconnect_reasons[reason] : "unknown",
1195 case SSH2_MSG_IGNORE:
1197 case SSH2_MSG_DEBUG:
1199 /* log the debug message */
1204 /* XXX maybe we should actually take notice of this */
1205 always_display = ssh2_pkt_getbool(ssh);
1206 ssh_pkt_getstring(ssh, &msg, &msglen);
1208 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
1215 * These packets we need do nothing about here.
1217 case SSH2_MSG_UNIMPLEMENTED:
1218 case SSH2_MSG_SERVICE_REQUEST:
1219 case SSH2_MSG_SERVICE_ACCEPT:
1220 case SSH2_MSG_KEXINIT:
1221 case SSH2_MSG_NEWKEYS:
1222 case SSH2_MSG_KEXDH_INIT:
1223 case SSH2_MSG_KEXDH_REPLY:
1224 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1225 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1226 case SSH2_MSG_KEX_DH_GEX_INIT:
1227 case SSH2_MSG_KEX_DH_GEX_REPLY:
1228 case SSH2_MSG_USERAUTH_REQUEST:
1229 case SSH2_MSG_USERAUTH_FAILURE:
1230 case SSH2_MSG_USERAUTH_SUCCESS:
1231 case SSH2_MSG_USERAUTH_BANNER:
1232 case SSH2_MSG_USERAUTH_PK_OK:
1233 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1234 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1235 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1236 case SSH2_MSG_GLOBAL_REQUEST:
1237 case SSH2_MSG_REQUEST_SUCCESS:
1238 case SSH2_MSG_REQUEST_FAILURE:
1239 case SSH2_MSG_CHANNEL_OPEN:
1240 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1241 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1242 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1243 case SSH2_MSG_CHANNEL_DATA:
1244 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1245 case SSH2_MSG_CHANNEL_EOF:
1246 case SSH2_MSG_CHANNEL_CLOSE:
1247 case SSH2_MSG_CHANNEL_REQUEST:
1248 case SSH2_MSG_CHANNEL_SUCCESS:
1249 case SSH2_MSG_CHANNEL_FAILURE:
1253 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1256 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1257 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1265 static void ssh1_pktout_size(Ssh ssh, int len)
1269 len += 5; /* type and CRC */
1270 pad = 8 - (len % 8);
1273 ssh->pktout.length = len - 5;
1274 if (ssh->pktout.maxlen < biglen) {
1275 ssh->pktout.maxlen = biglen;
1277 /* Allocate enough buffer space for extra block
1278 * for MS CryptEncrypt() */
1279 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1282 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1286 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1289 static void s_wrpkt_start(Ssh ssh, int type, int len)
1291 ssh1_pktout_size(ssh, len);
1292 ssh->pktout.type = type;
1293 /* Initialise log omission state */
1294 ssh->pktout_nblanks = 0;
1295 ssh->pktout_blanks = NULL;
1298 static int s_wrpkt_prepare(Ssh ssh)
1304 * XXX various versions of SC (including 8.8.4) screw up the
1305 * register allocation in this function and use the same register
1306 * (D6) for len and as a temporary, with predictable results. The
1307 * following sledgehammer prevents this.
1313 ssh->pktout.body[-1] = ssh->pktout.type;
1316 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1317 ssh1_pkt_type(ssh->pktout.type),
1318 ssh->pktout.body, ssh->pktout.length,
1319 ssh->pktout_nblanks, ssh->pktout_blanks);
1320 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1321 ssh->pktout_nblanks = 0;
1323 if (ssh->v1_compressing) {
1324 unsigned char *compblk;
1326 zlib_compress_block(ssh->cs_comp_ctx,
1327 ssh->pktout.body - 1, ssh->pktout.length + 1,
1328 &compblk, &complen);
1329 ssh1_pktout_size(ssh, complen - 1);
1330 memcpy(ssh->pktout.body - 1, compblk, complen);
1334 len = ssh->pktout.length + 5; /* type and CRC */
1335 pad = 8 - (len % 8);
1338 for (i = 0; i < pad; i++)
1339 ssh->pktout.data[i + 4] = random_byte();
1340 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1341 PUT_32BIT(ssh->pktout.data + biglen, crc);
1342 PUT_32BIT(ssh->pktout.data, len);
1345 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1350 static void s_wrpkt(Ssh ssh)
1353 len = s_wrpkt_prepare(ssh);
1354 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1355 if (backlog > SSH_MAX_BACKLOG)
1356 ssh_throttle_all(ssh, 1, backlog);
1359 static void s_wrpkt_defer(Ssh ssh)
1362 len = s_wrpkt_prepare(ssh);
1363 if (ssh->deferred_len + len > ssh->deferred_size) {
1364 ssh->deferred_size = ssh->deferred_len + len + 128;
1365 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1369 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1370 ssh->deferred_len += len;
1374 * Construct a packet with the specified contents.
1376 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1378 unsigned char *p, *argp, argchar;
1379 unsigned long argint;
1380 int pktlen, argtype, arglen;
1384 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1387 (void) va_arg(ap1, int);
1391 (void) va_arg(ap1, int);
1395 (void) va_arg(ap1, unsigned char *);
1396 arglen = va_arg(ap1, int);
1400 argp = va_arg(ap1, unsigned char *);
1401 arglen = strlen((char *)argp);
1402 pktlen += 4 + arglen;
1405 bn = va_arg(ap1, Bignum);
1406 pktlen += ssh1_bignum_length(bn);
1411 /* ignore this pass */
1418 s_wrpkt_start(ssh, pkttype, pktlen);
1419 p = ssh->pktout.body;
1421 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1422 int offset = p - ssh->pktout.body, len = 0;
1424 /* Actual fields in the packet */
1426 argint = va_arg(ap2, int);
1427 PUT_32BIT(p, argint);
1431 argchar = (unsigned char) va_arg(ap2, int);
1436 argp = va_arg(ap2, unsigned char *);
1437 arglen = va_arg(ap2, int);
1438 memcpy(p, argp, arglen);
1442 argp = va_arg(ap2, unsigned char *);
1443 arglen = strlen((char *)argp);
1444 PUT_32BIT(p, arglen);
1445 memcpy(p + 4, argp, arglen);
1449 bn = va_arg(ap2, Bignum);
1450 len = ssh1_write_bignum(p, bn);
1452 /* Tokens for modifications to packet logging */
1454 dont_log_password(ssh, PKTLOG_BLANK);
1457 dont_log_data(ssh, PKTLOG_OMIT);
1460 end_log_omission(ssh);
1464 /* Deal with logfile omission, if required. */
1465 if (len && (ssh->pktout_logmode != PKTLOG_EMIT)) {
1466 ssh->pktout_nblanks++;
1467 ssh->pktout_blanks = sresize(ssh->pktout_blanks,
1468 ssh->pktout_nblanks,
1470 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset = offset;
1471 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1472 ssh->pktout_blanks[ssh->pktout_nblanks-1].type =
1473 ssh->pktout_logmode;
1478 static void send_packet(Ssh ssh, int pkttype, ...)
1481 va_start(ap1, pkttype);
1482 va_start(ap2, pkttype);
1483 construct_packet(ssh, pkttype, ap1, ap2);
1487 static void defer_packet(Ssh ssh, int pkttype, ...)
1490 va_start(ap1, pkttype);
1491 va_start(ap2, pkttype);
1492 construct_packet(ssh, pkttype, ap1, ap2);
1496 static int ssh_versioncmp(char *a, char *b)
1499 unsigned long av, bv;
1501 av = strtoul(a, &ae, 10);
1502 bv = strtoul(b, &be, 10);
1504 return (av < bv ? -1 : +1);
1509 av = strtoul(ae, &ae, 10);
1510 bv = strtoul(be, &be, 10);
1512 return (av < bv ? -1 : +1);
1517 * Utility routines for putting an SSH-protocol `string' and
1518 * `uint32' into a SHA state.
1521 static void sha_string(SHA_State * s, void *str, int len)
1523 unsigned char lenblk[4];
1524 PUT_32BIT(lenblk, len);
1525 SHA_Bytes(s, lenblk, 4);
1526 SHA_Bytes(s, str, len);
1529 static void sha_uint32(SHA_State * s, unsigned i)
1531 unsigned char intblk[4];
1532 PUT_32BIT(intblk, i);
1533 SHA_Bytes(s, intblk, 4);
1537 * SSH2 packet construction functions.
1539 static void ssh2_pkt_ensure(Ssh ssh, int length)
1541 if (ssh->pktout.maxlen < length) {
1542 ssh->pktout.maxlen = length + 256;
1543 ssh->pktout.data = sresize(ssh->pktout.data,
1544 ssh->pktout.maxlen + APIEXTRA,
1546 if (!ssh->pktout.data)
1547 fatalbox("Out of memory");
1550 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1552 if (ssh->pktout_logmode != PKTLOG_EMIT) {
1553 ssh->pktout_nblanks++;
1554 ssh->pktout_blanks = sresize(ssh->pktout_blanks, ssh->pktout_nblanks,
1556 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset =
1557 ssh->pktout.length - 6;
1558 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1559 ssh->pktout_blanks[ssh->pktout_nblanks-1].type = ssh->pktout_logmode;
1561 ssh->pktout.length += len;
1562 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1563 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1565 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1567 ssh2_pkt_adddata(ssh, &byte, 1);
1569 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1571 ssh->pktout.length = 5;
1572 ssh->pktout_nblanks = 0; ssh->pktout_blanks = NULL;
1573 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1575 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1577 ssh2_pkt_adddata(ssh, &value, 1);
1579 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1582 PUT_32BIT(x, value);
1583 ssh2_pkt_adddata(ssh, x, 4);
1585 static void ssh2_pkt_addstring_start(Ssh ssh)
1587 ssh2_pkt_adduint32(ssh, 0);
1588 ssh->pktout.savedpos = ssh->pktout.length;
1590 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1592 ssh2_pkt_adddata(ssh, data, strlen(data));
1593 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1594 ssh->pktout.length - ssh->pktout.savedpos);
1596 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1598 ssh2_pkt_adddata(ssh, data, len);
1599 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1600 ssh->pktout.length - ssh->pktout.savedpos);
1602 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1604 ssh2_pkt_addstring_start(ssh);
1605 ssh2_pkt_addstring_str(ssh, data);
1607 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1610 int i, n = (bignum_bitcount(b) + 7) / 8;
1611 p = snewn(n + 1, unsigned char);
1613 fatalbox("out of memory");
1615 for (i = 1; i <= n; i++)
1616 p[i] = bignum_byte(b, n - i);
1618 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1620 memmove(p, p + i, n + 1 - i);
1624 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1628 p = ssh2_mpint_fmt(b, &len);
1629 ssh2_pkt_addstring_start(ssh);
1630 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1635 * Construct an SSH2 final-form packet: compress it, encrypt it,
1636 * put the MAC on it. Final packet, ready to be sent, is stored in
1637 * ssh->pktout.data. Total length is returned.
1639 static int ssh2_pkt_construct(Ssh ssh)
1641 int cipherblk, maclen, padding, i;
1644 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1645 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1646 ssh->pktout.data + 6, ssh->pktout.length - 6,
1647 ssh->pktout_nblanks, ssh->pktout_blanks);
1648 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1649 ssh->pktout_nblanks = 0;
1652 * Compress packet payload.
1655 unsigned char *newpayload;
1658 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1659 ssh->pktout.length - 5,
1660 &newpayload, &newlen)) {
1661 ssh->pktout.length = 5;
1662 ssh2_pkt_adddata(ssh, newpayload, newlen);
1668 * Add padding. At least four bytes, and must also bring total
1669 * length (minus MAC) up to a multiple of the block size.
1671 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1672 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1675 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1676 maclen = ssh->csmac ? ssh->csmac->len : 0;
1677 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1678 ssh->pktout.data[4] = padding;
1679 for (i = 0; i < padding; i++)
1680 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1681 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1683 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1684 ssh->pktout.length + padding,
1685 ssh->v2_outgoing_sequence);
1686 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1689 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1690 ssh->pktout.data, ssh->pktout.length + padding);
1692 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1693 return ssh->pktout.length + padding + maclen;
1697 * Construct and send an SSH2 packet immediately.
1699 static void ssh2_pkt_send(Ssh ssh)
1703 len = ssh2_pkt_construct(ssh);
1704 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1705 if (backlog > SSH_MAX_BACKLOG)
1706 ssh_throttle_all(ssh, 1, backlog);
1710 * Construct an SSH2 packet and add it to a deferred data block.
1711 * Useful for sending multiple packets in a single sk_write() call,
1712 * to prevent a traffic-analysing listener from being able to work
1713 * out the length of any particular packet (such as the password
1716 * Note that because SSH2 sequence-numbers its packets, this can
1717 * NOT be used as an m4-style `defer' allowing packets to be
1718 * constructed in one order and sent in another.
1720 static void ssh2_pkt_defer(Ssh ssh)
1722 int len = ssh2_pkt_construct(ssh);
1723 if (ssh->deferred_len + len > ssh->deferred_size) {
1724 ssh->deferred_size = ssh->deferred_len + len + 128;
1725 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1729 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1730 ssh->deferred_len += len;
1734 * Send the whole deferred data block constructed by
1735 * ssh2_pkt_defer() or SSH1's defer_packet().
1737 static void ssh_pkt_defersend(Ssh ssh)
1740 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1742 ssh->deferred_len = ssh->deferred_size = 0;
1743 sfree(ssh->deferred_send_data);
1744 ssh->deferred_send_data = NULL;
1745 if (backlog > SSH_MAX_BACKLOG)
1746 ssh_throttle_all(ssh, 1, backlog);
1750 void bndebug(char *string, Bignum b)
1754 p = ssh2_mpint_fmt(b, &len);
1755 debug(("%s", string));
1756 for (i = 0; i < len; i++)
1757 debug((" %02x", p[i]));
1763 static void sha_mpint(SHA_State * s, Bignum b)
1767 p = ssh2_mpint_fmt(b, &len);
1768 sha_string(s, p, len);
1773 * Packet decode functions for both SSH1 and SSH2.
1775 static unsigned long ssh_pkt_getuint32(Ssh ssh)
1777 unsigned long value;
1778 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1779 return 0; /* arrgh, no way to decline (FIXME?) */
1780 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1781 ssh->pktin.savedpos += 4;
1784 static int ssh2_pkt_getbool(Ssh ssh)
1786 unsigned long value;
1787 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1788 return 0; /* arrgh, no way to decline (FIXME?) */
1789 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
1790 ssh->pktin.savedpos++;
1793 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
1798 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1800 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1804 ssh->pktin.savedpos += 4;
1805 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1807 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
1808 ssh->pktin.savedpos += *length;
1810 static void *ssh_pkt_getdata(Ssh ssh, int length)
1812 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1814 ssh->pktin.savedpos += length;
1815 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1817 static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1818 unsigned char **keystr)
1822 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1823 ssh->pktin.length - ssh->pktin.savedpos,
1829 ssh->pktin.savedpos += j;
1830 assert(ssh->pktin.savedpos < ssh->pktin.length);
1834 static Bignum ssh1_pkt_getmp(Ssh ssh)
1839 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1840 ssh->pktin.length - ssh->pktin.savedpos, &b);
1845 ssh->pktin.savedpos += j;
1848 static Bignum ssh2_pkt_getmp(Ssh ssh)
1854 ssh_pkt_getstring(ssh, &p, &length);
1858 bombout(("internal error: Can't handle negative mpints"));
1861 b = bignum_from_bytes((unsigned char *)p, length);
1866 * Helper function to add an SSH2 signature blob to a packet.
1867 * Expects to be shown the public key blob as well as the signature
1868 * blob. Normally works just like ssh2_pkt_addstring, but will
1869 * fiddle with the signature packet if necessary for
1870 * BUG_SSH2_RSA_PADDING.
1872 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1873 void *sigblob_v, int sigblob_len)
1875 unsigned char *pkblob = (unsigned char *)pkblob_v;
1876 unsigned char *sigblob = (unsigned char *)sigblob_v;
1878 /* dmemdump(pkblob, pkblob_len); */
1879 /* dmemdump(sigblob, sigblob_len); */
1882 * See if this is in fact an ssh-rsa signature and a buggy
1883 * server; otherwise we can just do this the easy way.
1885 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1886 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1887 int pos, len, siglen;
1890 * Find the byte length of the modulus.
1893 pos = 4+7; /* skip over "ssh-rsa" */
1894 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1895 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1896 pos += 4; /* find modulus itself */
1897 while (len > 0 && pkblob[pos] == 0)
1899 /* debug(("modulus length is %d\n", len)); */
1902 * Now find the signature integer.
1904 pos = 4+7; /* skip over "ssh-rsa" */
1905 siglen = GET_32BIT(sigblob+pos);
1906 /* debug(("signature length is %d\n", siglen)); */
1908 if (len != siglen) {
1909 unsigned char newlen[4];
1910 ssh2_pkt_addstring_start(ssh);
1911 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1912 /* dmemdump(sigblob, pos); */
1913 pos += 4; /* point to start of actual sig */
1914 PUT_32BIT(newlen, len);
1915 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1916 /* dmemdump(newlen, 4); */
1918 while (len-- > siglen) {
1919 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1920 /* dmemdump(newlen, 1); */
1922 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1923 /* dmemdump(sigblob+pos, siglen); */
1927 /* Otherwise fall through and do it the easy way. */
1930 ssh2_pkt_addstring_start(ssh);
1931 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1935 * Examine the remote side's version string and compare it against
1936 * a list of known buggy implementations.
1938 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1940 char *imp; /* pointer to implementation part */
1942 imp += strcspn(imp, "-");
1944 imp += strcspn(imp, "-");
1947 ssh->remote_bugs = 0;
1949 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1950 (ssh->cfg.sshbug_ignore1 == AUTO &&
1951 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1952 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1953 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1954 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1956 * These versions don't support SSH1_MSG_IGNORE, so we have
1957 * to use a different defence against password length
1960 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1961 logevent("We believe remote version has SSH1 ignore bug");
1964 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1965 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1966 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1968 * These versions need a plain password sent; they can't
1969 * handle having a null and a random length of data after
1972 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1973 logevent("We believe remote version needs a plain SSH1 password");
1976 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1977 (ssh->cfg.sshbug_rsa1 == AUTO &&
1978 (!strcmp(imp, "Cisco-1.25")))) {
1980 * These versions apparently have no clue whatever about
1981 * RSA authentication and will panic and die if they see
1982 * an AUTH_RSA message.
1984 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1985 logevent("We believe remote version can't handle RSA authentication");
1988 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1989 (ssh->cfg.sshbug_hmac2 == AUTO &&
1990 !wc_match("* VShell", imp) &&
1991 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1992 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1993 wc_match("2.1 *", imp)))) {
1995 * These versions have the HMAC bug.
1997 ssh->remote_bugs |= BUG_SSH2_HMAC;
1998 logevent("We believe remote version has SSH2 HMAC bug");
2001 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2002 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2003 !wc_match("* VShell", imp) &&
2004 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2006 * These versions have the key-derivation bug (failing to
2007 * include the literal shared secret in the hashes that
2008 * generate the keys).
2010 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2011 logevent("We believe remote version has SSH2 key-derivation bug");
2014 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2015 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2016 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2017 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2019 * These versions have the SSH2 RSA padding bug.
2021 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2022 logevent("We believe remote version has SSH2 RSA padding bug");
2025 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2026 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2027 wc_match("OpenSSH_2.[0-2]*", imp))) {
2029 * These versions have the SSH2 session-ID bug in
2030 * public-key authentication.
2032 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2033 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2036 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
2038 * User specified the SSH2 DH GEX bug.
2040 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
2041 logevent("We believe remote version has SSH2 DH group exchange bug");
2045 static int do_ssh_init(Ssh ssh, unsigned char c)
2047 struct do_ssh_init_state {
2055 crState(do_ssh_init_state);
2057 crBegin(ssh->do_ssh_init_crstate);
2059 /* Search for the string "SSH-" in the input. */
2062 static const int transS[] = { 1, 2, 2, 1 };
2063 static const int transH[] = { 0, 0, 3, 0 };
2064 static const int transminus[] = { 0, 0, 0, -1 };
2066 s->i = transS[s->i];
2068 s->i = transH[s->i];
2070 s->i = transminus[s->i];
2075 crReturn(1); /* get another character */
2079 s->vstring = snewn(s->vstrsize, char);
2080 strcpy(s->vstring, "SSH-");
2084 crReturn(1); /* get another char */
2085 if (s->vslen >= s->vstrsize - 1) {
2087 s->vstring = sresize(s->vstring, s->vstrsize, char);
2089 s->vstring[s->vslen++] = c;
2092 s->version[s->i] = '\0';
2094 } else if (s->i < sizeof(s->version) - 1)
2095 s->version[s->i++] = c;
2096 } else if (c == '\012')
2100 ssh->agentfwd_enabled = FALSE;
2101 ssh->rdpkt2_state.incoming_sequence = 0;
2103 s->vstring[s->vslen] = 0;
2104 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2107 vlog = snewn(20 + s->vslen, char);
2108 sprintf(vlog, "Server version: %s", s->vstring);
2112 ssh_detect_bugs(ssh, s->vstring);
2115 * Decide which SSH protocol version to support.
2118 /* Anything strictly below "2.0" means protocol 1 is supported. */
2119 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2120 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2121 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2123 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2124 bombout(("SSH protocol version 1 required by user but not provided by server"));
2127 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2128 bombout(("SSH protocol version 2 required by user but not provided by server"));
2132 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2136 char verstring[80], vlog[100];
2137 sprintf(verstring, "SSH-2.0-%s", sshver);
2138 SHA_Init(&ssh->exhashbase);
2140 * Hash our version string and their version string.
2142 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2143 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2144 sprintf(vlog, "We claim version: %s", verstring);
2146 strcat(verstring, "\012");
2147 logevent("Using SSH protocol version 2");
2148 sk_write(ssh->s, verstring, strlen(verstring));
2149 ssh->protocol = ssh2_protocol;
2151 ssh->s_rdpkt = ssh2_rdpkt;
2156 char verstring[80], vlog[100];
2157 sprintf(verstring, "SSH-%s-%s",
2158 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
2160 sprintf(vlog, "We claim version: %s", verstring);
2162 strcat(verstring, "\012");
2164 logevent("Using SSH protocol version 1");
2165 sk_write(ssh->s, verstring, strlen(verstring));
2166 ssh->protocol = ssh1_protocol;
2168 ssh->s_rdpkt = ssh1_rdpkt;
2170 update_specials_menu(ssh->frontend);
2171 ssh->state = SSH_STATE_BEFORE_SIZE;
2178 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2180 crBegin(ssh->ssh_gotdata_crstate);
2183 * To begin with, feed the characters one by one to the
2184 * protocol initialisation / selection function do_ssh_init().
2185 * When that returns 0, we're done with the initial greeting
2186 * exchange and can move on to packet discipline.
2189 int ret; /* need not be kept across crReturn */
2191 crReturnV; /* more data please */
2192 ret = do_ssh_init(ssh, *data);
2200 * We emerge from that loop when the initial negotiation is
2201 * over and we have selected an s_rdpkt function. Now pass
2202 * everything to s_rdpkt, and then pass the resulting packets
2203 * to the proper protocol handler.
2208 while (datalen > 0) {
2209 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2210 if (ssh->state == SSH_STATE_CLOSED) {
2213 ssh->protocol(ssh, NULL, 0, 1);
2214 if (ssh->state == SSH_STATE_CLOSED) {
2224 static void ssh_do_close(Ssh ssh)
2227 struct ssh_channel *c;
2229 ssh->state = SSH_STATE_CLOSED;
2235 * Now we must shut down any port and X forwardings going
2236 * through this connection.
2238 if (ssh->channels) {
2239 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2242 x11_close(c->u.x11.s);
2245 pfd_close(c->u.pfd.s);
2248 del234(ssh->channels, c);
2249 if (ssh->version == 2)
2250 bufchain_clear(&c->v.v2.outbuffer);
2256 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2259 Ssh ssh = (Ssh) plug;
2262 /* A socket error has occurred. */
2263 logevent(error_msg);
2264 connection_fatal(ssh->frontend, "%s", error_msg);
2266 /* Otherwise, the remote side closed the connection normally. */
2271 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2273 Ssh ssh = (Ssh) plug;
2274 ssh_gotdata(ssh, (unsigned char *)data, len);
2275 if (ssh->state == SSH_STATE_CLOSED) {
2282 static void ssh_sent(Plug plug, int bufsize)
2284 Ssh ssh = (Ssh) plug;
2286 * If the send backlog on the SSH socket itself clears, we
2287 * should unthrottle the whole world if it was throttled.
2289 if (bufsize < SSH_MAX_BACKLOG)
2290 ssh_throttle_all(ssh, 0, bufsize);
2294 * Connect to specified host and port.
2295 * Returns an error message, or NULL on success.
2296 * Also places the canonical host name into `realhost'. It must be
2297 * freed by the caller.
2299 static const char *connect_to_host(Ssh ssh, char *host, int port,
2300 char **realhost, int nodelay, int keepalive)
2302 static const struct plug_function_table fn_table = {
2312 ssh->savedhost = snewn(1 + strlen(host), char);
2313 if (!ssh->savedhost)
2314 fatalbox("Out of memory");
2315 strcpy(ssh->savedhost, host);
2318 port = 22; /* default ssh port */
2319 ssh->savedport = port;
2324 logeventf(ssh, "Looking up host \"%s\"", host);
2325 addr = name_lookup(host, port, realhost, &ssh->cfg);
2326 if ((err = sk_addr_error(addr)) != NULL) {
2336 sk_getaddr(addr, addrbuf, 100);
2337 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2339 ssh->fn = &fn_table;
2340 ssh->s = new_connection(addr, *realhost, port,
2341 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2342 if ((err = sk_socket_error(ssh->s)) != NULL) {
2351 * Throttle or unthrottle the SSH connection.
2353 static void ssh1_throttle(Ssh ssh, int adjust)
2355 int old_count = ssh->v1_throttle_count;
2356 ssh->v1_throttle_count += adjust;
2357 assert(ssh->v1_throttle_count >= 0);
2358 if (ssh->v1_throttle_count && !old_count) {
2359 sk_set_frozen(ssh->s, 1);
2360 } else if (!ssh->v1_throttle_count && old_count) {
2361 sk_set_frozen(ssh->s, 0);
2366 * Throttle or unthrottle _all_ local data streams (for when sends
2367 * on the SSH connection itself back up).
2369 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2372 struct ssh_channel *c;
2374 if (enable == ssh->throttled_all)
2376 ssh->throttled_all = enable;
2377 ssh->overall_bufsize = bufsize;
2380 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2382 case CHAN_MAINSESSION:
2384 * This is treated separately, outside the switch.
2388 x11_override_throttle(c->u.x11.s, enable);
2391 /* Agent channels require no buffer management. */
2394 pfd_override_throttle(c->u.pfd.s, enable);
2401 * Username and password input, abstracted off into routines
2402 * reusable in several places - even between SSH1 and SSH2.
2405 /* Set up a username or password input loop on a given buffer. */
2406 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2408 ssh->userpass_input_buffer = buffer;
2409 ssh->userpass_input_buflen = buflen;
2410 ssh->userpass_input_bufpos = 0;
2411 ssh->userpass_input_echo = echo;
2415 * Process some terminal data in the course of username/password
2416 * input. Returns >0 for success (line of input returned in
2417 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2418 * for inconclusive (keep waiting for more input please).
2420 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2425 switch (c = *in++) {
2428 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2429 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2434 if (ssh->userpass_input_bufpos > 0) {
2435 if (ssh->userpass_input_echo)
2436 c_write_str(ssh, "\b \b");
2437 ssh->userpass_input_bufpos--;
2442 while (ssh->userpass_input_bufpos > 0) {
2443 if (ssh->userpass_input_echo)
2444 c_write_str(ssh, "\b \b");
2445 ssh->userpass_input_bufpos--;
2454 * This simplistic check for printability is disabled
2455 * when we're doing password input, because some people
2456 * have control characters in their passwords.o
2458 if ((!ssh->userpass_input_echo ||
2459 (c >= ' ' && c <= '~') ||
2460 ((unsigned char) c >= 160))
2461 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2462 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2463 if (ssh->userpass_input_echo)
2464 c_write(ssh, &c, 1);
2472 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2474 Ssh ssh = (Ssh) sshv;
2476 ssh->agent_response = reply;
2477 ssh->agent_response_len = replylen;
2479 if (ssh->version == 1)
2480 do_ssh1_login(ssh, NULL, -1, 0);
2482 do_ssh2_authconn(ssh, NULL, -1, 0);
2485 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2487 struct ssh_channel *c = (struct ssh_channel *)cv;
2489 void *sentreply = reply;
2492 /* Fake SSH_AGENT_FAILURE. */
2493 sentreply = "\0\0\0\1\5";
2496 if (ssh->version == 2) {
2497 ssh2_add_channel_data(c, sentreply, replylen);
2500 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2501 PKT_INT, c->remoteid,
2504 PKT_DATA, sentreply, replylen,
2513 * Handle the key exchange and user authentication phases.
2515 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2518 unsigned char cookie[8], *ptr;
2519 struct RSAKey servkey, hostkey;
2520 struct MD5Context md5c;
2521 struct do_ssh1_login_state {
2523 unsigned char *rsabuf, *keystr1, *keystr2;
2524 unsigned long supported_ciphers_mask, supported_auths_mask;
2525 int tried_publickey, tried_agent;
2526 int tis_auth_refused, ccard_auth_refused;
2527 unsigned char session_id[16];
2530 void *publickey_blob;
2531 int publickey_bloblen;
2537 unsigned char request[5], *response, *p;
2546 crState(do_ssh1_login_state);
2548 crBegin(ssh->do_ssh1_login_crstate);
2553 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2554 bombout(("Public key packet not received"));
2558 logevent("Received public keys");
2560 ptr = ssh_pkt_getdata(ssh, 8);
2562 bombout(("SSH1 public key packet stopped before random cookie"));
2565 memcpy(cookie, ptr, 8);
2567 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2568 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
2569 bombout(("Failed to read SSH1 public keys from public key packet"));
2574 * Log the host key fingerprint.
2578 logevent("Host key fingerprint is:");
2579 strcpy(logmsg, " ");
2580 hostkey.comment = NULL;
2581 rsa_fingerprint(logmsg + strlen(logmsg),
2582 sizeof(logmsg) - strlen(logmsg), &hostkey);
2586 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2587 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2588 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
2590 ssh->v1_local_protoflags =
2591 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2592 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2595 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2596 MD5Update(&md5c, s->keystr1, servkey.bytes);
2597 MD5Update(&md5c, cookie, 8);
2598 MD5Final(s->session_id, &md5c);
2600 for (i = 0; i < 32; i++)
2601 ssh->session_key[i] = random_byte();
2604 * Verify that the `bits' and `bytes' parameters match.
2606 if (hostkey.bits > hostkey.bytes * 8 ||
2607 servkey.bits > servkey.bytes * 8) {
2608 bombout(("SSH1 public keys were badly formatted"));
2612 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2614 s->rsabuf = snewn(s->len, unsigned char);
2616 fatalbox("Out of memory");
2619 * Verify the host key.
2623 * First format the key into a string.
2625 int len = rsastr_len(&hostkey);
2626 char fingerprint[100];
2627 char *keystr = snewn(len, char);
2629 fatalbox("Out of memory");
2630 rsastr_fmt(keystr, &hostkey);
2631 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2632 verify_ssh_host_key(ssh->frontend,
2633 ssh->savedhost, ssh->savedport, "rsa", keystr,
2638 for (i = 0; i < 32; i++) {
2639 s->rsabuf[i] = ssh->session_key[i];
2641 s->rsabuf[i] ^= s->session_id[i];
2644 if (hostkey.bytes > servkey.bytes) {
2645 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2647 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2649 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2651 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2654 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2658 logevent("Encrypted session key");
2661 int cipher_chosen = 0, warn = 0;
2662 char *cipher_string = NULL;
2664 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2665 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2666 if (next_cipher == CIPHER_WARN) {
2667 /* If/when we choose a cipher, warn about it */
2669 } else if (next_cipher == CIPHER_AES) {
2670 /* XXX Probably don't need to mention this. */
2671 logevent("AES not supported in SSH1, skipping");
2673 switch (next_cipher) {
2674 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2675 cipher_string = "3DES"; break;
2676 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2677 cipher_string = "Blowfish"; break;
2678 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2679 cipher_string = "single-DES"; break;
2681 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2685 if (!cipher_chosen) {
2686 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2687 bombout(("Server violates SSH 1 protocol by not "
2688 "supporting 3DES encryption"));
2690 /* shouldn't happen */
2691 bombout(("No supported ciphers found"));
2695 /* Warn about chosen cipher if necessary. */
2697 askcipher(ssh->frontend, cipher_string, 0);
2700 switch (s->cipher_type) {
2701 case SSH_CIPHER_3DES:
2702 logevent("Using 3DES encryption");
2704 case SSH_CIPHER_DES:
2705 logevent("Using single-DES encryption");
2707 case SSH_CIPHER_BLOWFISH:
2708 logevent("Using Blowfish encryption");
2712 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2713 PKT_CHAR, s->cipher_type,
2714 PKT_DATA, cookie, 8,
2715 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2716 PKT_DATA, s->rsabuf, s->len,
2717 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2719 logevent("Trying to enable encryption...");
2723 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2724 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2726 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2727 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2728 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2730 ssh->crcda_ctx = crcda_make_context();
2731 logevent("Installing CRC compensation attack detector");
2733 if (servkey.modulus) {
2734 sfree(servkey.modulus);
2735 servkey.modulus = NULL;
2737 if (servkey.exponent) {
2738 sfree(servkey.exponent);
2739 servkey.exponent = NULL;
2741 if (hostkey.modulus) {
2742 sfree(hostkey.modulus);
2743 hostkey.modulus = NULL;
2745 if (hostkey.exponent) {
2746 sfree(hostkey.exponent);
2747 hostkey.exponent = NULL;
2751 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2752 bombout(("Encryption not successfully enabled"));
2756 logevent("Successfully started encryption");
2760 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2761 if (ssh_get_line && !ssh_getline_pw_only) {
2762 if (!ssh_get_line("login as: ",
2763 s->username, sizeof(s->username), FALSE)) {
2765 * get_line failed to get a username.
2768 logevent("No username provided. Abandoning session.");
2769 ssh_closing((Plug)ssh, NULL, 0, 0);
2773 int ret; /* need not be kept over crReturn */
2774 c_write_str(ssh, "login as: ");
2777 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2779 crWaitUntil(!ispkt);
2780 ret = process_userpass_input(ssh, in, inlen);
2784 c_write_str(ssh, "\r\n");
2787 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2788 s->username[sizeof(s->username)-1] = '\0';
2791 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2793 char userlog[22 + sizeof(s->username)];
2794 sprintf(userlog, "Sent username \"%s\"", s->username);
2796 if (flags & FLAG_INTERACTIVE &&
2797 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2798 strcat(userlog, "\r\n");
2799 c_write_str(ssh, userlog);
2806 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2807 /* We must not attempt PK auth. Pretend we've already tried it. */
2808 s->tried_publickey = s->tried_agent = 1;
2810 s->tried_publickey = s->tried_agent = 0;
2812 s->tis_auth_refused = s->ccard_auth_refused = 0;
2813 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2814 if (!filename_is_null(ssh->cfg.keyfile)) {
2815 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2816 &s->publickey_blob, &s->publickey_bloblen, NULL))
2817 s->publickey_blob = NULL;
2819 s->publickey_blob = NULL;
2821 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2822 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2824 if (agent_exists() && !s->tried_agent) {
2826 * Attempt RSA authentication using Pageant.
2832 logevent("Pageant is running. Requesting keys.");
2834 /* Request the keys held by the agent. */
2835 PUT_32BIT(s->request, 1);
2836 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2837 if (!agent_query(s->request, 5, &r, &s->responselen,
2838 ssh_agent_callback, ssh)) {
2842 bombout(("Unexpected data from server while waiting"
2843 " for agent response"));
2846 } while (ispkt || inlen > 0);
2847 r = ssh->agent_response;
2848 s->responselen = ssh->agent_response_len;
2850 s->response = (unsigned char *) r;
2851 if (s->response && s->responselen >= 5 &&
2852 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2853 s->p = s->response + 5;
2854 s->nkeys = GET_32BIT(s->p);
2858 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2861 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2864 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2867 if (s->publickey_blob &&
2868 !memcmp(s->p, s->publickey_blob,
2869 s->publickey_bloblen)) {
2870 logevent("This key matches configured key file");
2871 s->tried_publickey = 1;
2876 do { /* do while (0) to make breaking easy */
2877 n = ssh1_read_bignum
2878 (s->p, s->responselen-(s->p-s->response),
2883 n = ssh1_read_bignum
2884 (s->p, s->responselen-(s->p-s->response),
2889 if (s->responselen - (s->p-s->response) < 4)
2891 s->commentlen = GET_32BIT(s->p);
2893 if (s->responselen - (s->p-s->response) <
2896 s->commentp = (char *)s->p;
2897 s->p += s->commentlen;
2901 logevent("Pageant key list packet was truncated");
2905 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2906 PKT_BIGNUM, s->key.modulus, PKT_END);
2908 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2909 logevent("Key refused");
2912 logevent("Received RSA challenge");
2913 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2914 bombout(("Server's RSA challenge was badly formatted"));
2919 char *agentreq, *q, *ret;
2922 len = 1 + 4; /* message type, bit count */
2923 len += ssh1_bignum_length(s->key.exponent);
2924 len += ssh1_bignum_length(s->key.modulus);
2925 len += ssh1_bignum_length(s->challenge);
2926 len += 16; /* session id */
2927 len += 4; /* response format */
2928 agentreq = snewn(4 + len, char);
2929 PUT_32BIT(agentreq, len);
2931 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2932 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2934 q += ssh1_write_bignum(q, s->key.exponent);
2935 q += ssh1_write_bignum(q, s->key.modulus);
2936 q += ssh1_write_bignum(q, s->challenge);
2937 memcpy(q, s->session_id, 16);
2939 PUT_32BIT(q, 1); /* response format */
2940 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2941 ssh_agent_callback, ssh)) {
2946 bombout(("Unexpected data from server"
2947 " while waiting for agent"
2951 } while (ispkt || inlen > 0);
2952 vret = ssh->agent_response;
2953 retlen = ssh->agent_response_len;
2958 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2959 logevent("Sending Pageant's response");
2960 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2961 PKT_DATA, ret + 5, 16,
2965 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2967 ("Pageant's response accepted");
2968 if (flags & FLAG_VERBOSE) {
2969 c_write_str(ssh, "Authenticated using"
2971 c_write(ssh, s->commentp,
2973 c_write_str(ssh, "\" from agent\r\n");
2978 ("Pageant's response not accepted");
2981 ("Pageant failed to answer challenge");
2985 logevent("No reply received from Pageant");
2988 freebn(s->key.exponent);
2989 freebn(s->key.modulus);
2990 freebn(s->challenge);
2999 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3000 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3002 if (ssh->cfg.try_tis_auth &&
3003 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3004 !s->tis_auth_refused) {
3005 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3006 logevent("Requested TIS authentication");
3007 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3009 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3010 logevent("TIS authentication declined");
3011 if (flags & FLAG_INTERACTIVE)
3012 c_write_str(ssh, "TIS authentication refused.\r\n");
3013 s->tis_auth_refused = 1;
3019 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3021 bombout(("TIS challenge packet was badly formed"));
3024 logevent("Received TIS challenge");
3025 if (challengelen > sizeof(s->prompt) - 1)
3026 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3027 memcpy(s->prompt, challenge, challengelen);
3028 /* Prompt heuristic comes from OpenSSH */
3029 strncpy(s->prompt + challengelen,
3030 memchr(s->prompt, '\n', challengelen) ?
3031 "": "\r\nResponse: ",
3032 (sizeof s->prompt) - challengelen);
3033 s->prompt[(sizeof s->prompt) - 1] = '\0';
3036 if (ssh->cfg.try_tis_auth &&
3037 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3038 !s->ccard_auth_refused) {
3039 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3040 logevent("Requested CryptoCard authentication");
3041 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3043 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3044 logevent("CryptoCard authentication declined");
3045 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3046 s->ccard_auth_refused = 1;
3052 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3054 bombout(("CryptoCard challenge packet was badly formed"));
3057 logevent("Received CryptoCard challenge");
3058 if (challengelen > sizeof(s->prompt) - 1)
3059 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3060 memcpy(s->prompt, challenge, challengelen);
3061 strncpy(s->prompt + challengelen,
3062 memchr(s->prompt, '\n', challengelen) ?
3063 "" : "\r\nResponse: ",
3064 sizeof(s->prompt) - challengelen);
3065 s->prompt[sizeof(s->prompt) - 1] = '\0';
3068 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3069 sprintf(s->prompt, "%.90s@%.90s's password: ",
3070 s->username, ssh->savedhost);
3072 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3073 char *comment = NULL;
3076 if (flags & FLAG_VERBOSE)
3077 c_write_str(ssh, "Trying public key authentication.\r\n");
3078 logeventf(ssh, "Trying public key \"%s\"",
3079 filename_to_str(&ssh->cfg.keyfile));
3080 type = key_type(&ssh->cfg.keyfile);
3081 if (type != SSH_KEYTYPE_SSH1) {
3082 sprintf(msgbuf, "Key is of wrong type (%s)",
3083 key_type_to_str(type));
3085 c_write_str(ssh, msgbuf);
3086 c_write_str(ssh, "\r\n");
3087 s->tried_publickey = 1;
3090 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3091 if (flags & FLAG_VERBOSE)
3092 c_write_str(ssh, "No passphrase required.\r\n");
3095 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3100 * Show password prompt, having first obtained it via a TIS
3101 * or CryptoCard exchange if we're doing TIS or CryptoCard
3105 if (!ssh_get_line(s->prompt, s->password,
3106 sizeof(s->password), TRUE)) {
3108 * get_line failed to get a password (for example
3109 * because one was supplied on the command line
3110 * which has already failed to work). Terminate.
3112 send_packet(ssh, SSH1_MSG_DISCONNECT,
3113 PKT_STR, "No more passwords available to try",
3115 logevent("Unable to authenticate");
3116 connection_fatal(ssh->frontend, "Unable to authenticate");
3117 ssh_closing((Plug)ssh, NULL, 0, 0);
3121 /* Prompt may have come from server. We've munged it a bit, so
3122 * we know it to be zero-terminated at least once. */
3123 int ret; /* need not be saved over crReturn */
3124 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3127 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3129 crWaitUntil(!ispkt);
3130 ret = process_userpass_input(ssh, in, inlen);
3134 c_write_str(ssh, "\r\n");
3138 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3140 * Try public key authentication with the specified
3143 s->tried_publickey = 1;
3146 const char *error = NULL;
3147 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3150 c_write_str(ssh, "Couldn't load private key from ");
3151 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3152 c_write_str(ssh, " (");
3153 c_write_str(ssh, error);
3154 c_write_str(ssh, ").\r\n");
3155 continue; /* go and try password */
3158 c_write_str(ssh, "Wrong passphrase.\r\n");
3159 s->tried_publickey = 0;
3160 continue; /* try again */
3165 * Send a public key attempt.
3167 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3168 PKT_BIGNUM, s->key.modulus, PKT_END);
3171 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3172 c_write_str(ssh, "Server refused our public key.\r\n");
3173 continue; /* go and try password */
3175 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3176 bombout(("Bizarre response to offer of public key"));
3182 unsigned char buffer[32];
3183 Bignum challenge, response;
3185 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3186 bombout(("Server's RSA challenge was badly formatted"));
3189 response = rsadecrypt(challenge, &s->key);
3190 freebn(s->key.private_exponent);/* burn the evidence */
3192 for (i = 0; i < 32; i++) {
3193 buffer[i] = bignum_byte(response, 31 - i);
3197 MD5Update(&md5c, buffer, 32);
3198 MD5Update(&md5c, s->session_id, 16);
3199 MD5Final(buffer, &md5c);
3201 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3202 PKT_DATA, buffer, 16, PKT_END);
3209 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3210 if (flags & FLAG_VERBOSE)
3211 c_write_str(ssh, "Failed to authenticate with"
3212 " our public key.\r\n");
3213 continue; /* go and try password */
3214 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3215 bombout(("Bizarre response to RSA authentication response"));
3219 break; /* we're through! */
3221 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3223 * Defence against traffic analysis: we send a
3224 * whole bunch of packets containing strings of
3225 * different lengths. One of these strings is the
3226 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3227 * The others are all random data in
3228 * SSH1_MSG_IGNORE packets. This way a passive
3229 * listener can't tell which is the password, and
3230 * hence can't deduce the password length.
3232 * Anybody with a password length greater than 16
3233 * bytes is going to have enough entropy in their
3234 * password that a listener won't find it _that_
3235 * much help to know how long it is. So what we'll
3238 * - if password length < 16, we send 15 packets
3239 * containing string lengths 1 through 15
3241 * - otherwise, we let N be the nearest multiple
3242 * of 8 below the password length, and send 8
3243 * packets containing string lengths N through
3244 * N+7. This won't obscure the order of
3245 * magnitude of the password length, but it will
3246 * introduce a bit of extra uncertainty.
3248 * A few servers (the old 1.2.18 through 1.2.22)
3249 * can't deal with SSH1_MSG_IGNORE. For these
3250 * servers, we need an alternative defence. We make
3251 * use of the fact that the password is interpreted
3252 * as a C string: so we can append a NUL, then some
3255 * One server (a Cisco one) can deal with neither
3256 * SSH1_MSG_IGNORE _nor_ a padded password string.
3257 * For this server we are left with no defences
3258 * against password length sniffing.
3260 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3262 * The server can deal with SSH1_MSG_IGNORE, so
3263 * we can use the primary defence.
3265 int bottom, top, pwlen, i;
3268 pwlen = strlen(s->password);
3270 bottom = 0; /* zero length passwords are OK! :-) */
3273 bottom = pwlen & ~7;
3277 assert(pwlen >= bottom && pwlen <= top);
3279 randomstr = snewn(top + 1, char);
3281 for (i = bottom; i <= top; i++) {
3283 defer_packet(ssh, s->pwpkt_type,
3284 PKTT_PASSWORD, PKT_STR, s->password,
3285 PKTT_OTHER, PKT_END);
3287 for (j = 0; j < i; j++) {
3289 randomstr[j] = random_byte();
3290 } while (randomstr[j] == '\0');
3292 randomstr[i] = '\0';
3293 defer_packet(ssh, SSH1_MSG_IGNORE,
3294 PKT_STR, randomstr, PKT_END);
3297 logevent("Sending password with camouflage packets");
3298 ssh_pkt_defersend(ssh);
3301 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3303 * The server can't deal with SSH1_MSG_IGNORE
3304 * but can deal with padded passwords, so we
3305 * can use the secondary defence.
3311 len = strlen(s->password);
3312 if (len < sizeof(string)) {
3314 strcpy(string, s->password);
3315 len++; /* cover the zero byte */
3316 while (len < sizeof(string)) {
3317 string[len++] = (char) random_byte();
3322 logevent("Sending length-padded password");
3323 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3324 PKT_INT, len, PKT_DATA, ss, len,
3325 PKTT_OTHER, PKT_END);
3328 * The server has _both_
3329 * BUG_CHOKES_ON_SSH1_IGNORE and
3330 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3331 * therefore nothing we can do.
3334 len = strlen(s->password);
3335 logevent("Sending unpadded password");
3336 send_packet(ssh, s->pwpkt_type,
3337 PKTT_PASSWORD, PKT_INT, len,
3338 PKT_DATA, s->password, len,
3339 PKTT_OTHER, PKT_END);
3342 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3343 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3346 logevent("Sent password");
3347 memset(s->password, 0, strlen(s->password));
3349 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3350 if (flags & FLAG_VERBOSE)
3351 c_write_str(ssh, "Access denied\r\n");
3352 logevent("Authentication refused");
3353 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3354 bombout(("Strange packet received, type %d", ssh->pktin.type));
3359 logevent("Authentication successful");
3364 void sshfwd_close(struct ssh_channel *c)
3368 if (ssh->state != SSH_STATE_SESSION) {
3369 assert(ssh->state == SSH_STATE_CLOSED);
3373 if (c && !c->closes) {
3375 * If the channel's remoteid is -1, we have sent
3376 * CHANNEL_OPEN for this channel, but it hasn't even been
3377 * acknowledged by the server. So we must set a close flag
3378 * on it now, and then when the server acks the channel
3379 * open, we can close it then.
3381 if (((int)c->remoteid) != -1) {
3382 if (ssh->version == 1) {
3383 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3386 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3387 ssh2_pkt_adduint32(ssh, c->remoteid);
3391 c->closes = 1; /* sent MSG_CLOSE */
3392 if (c->type == CHAN_X11) {
3394 logevent("Forwarded X11 connection terminated");
3395 } else if (c->type == CHAN_SOCKDATA ||
3396 c->type == CHAN_SOCKDATA_DORMANT) {
3398 logevent("Forwarded port closed");
3403 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3407 if (ssh->state != SSH_STATE_SESSION) {
3408 assert(ssh->state == SSH_STATE_CLOSED);
3412 if (ssh->version == 1) {
3413 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3414 PKT_INT, c->remoteid,
3416 PKT_INT, len, PKT_DATA, buf, len,
3417 PKTT_OTHER, PKT_END);
3419 * In SSH1 we can return 0 here - implying that forwarded
3420 * connections are never individually throttled - because
3421 * the only circumstance that can cause throttling will be
3422 * the whole SSH connection backing up, in which case
3423 * _everything_ will be throttled as a whole.
3427 ssh2_add_channel_data(c, buf, len);
3428 return ssh2_try_send(c);
3432 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3436 if (ssh->state != SSH_STATE_SESSION) {
3437 assert(ssh->state == SSH_STATE_CLOSED);
3441 if (ssh->version == 1) {
3442 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3443 c->v.v1.throttling = 0;
3444 ssh1_throttle(ssh, -1);
3447 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3451 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3453 crBegin(ssh->ssh1_protocol_crstate);
3457 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3460 if (ssh->state == SSH_STATE_CLOSED)
3463 if (ssh->cfg.agentfwd && agent_exists()) {
3464 logevent("Requesting agent forwarding");
3465 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3469 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3470 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3471 bombout(("Protocol confusion"));
3473 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3474 logevent("Agent forwarding refused");
3476 logevent("Agent forwarding enabled");
3477 ssh->agentfwd_enabled = TRUE;
3481 if (ssh->cfg.x11_forward) {
3482 char proto[20], data[64];
3483 logevent("Requesting X11 forwarding");
3484 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3485 data, sizeof(data), ssh->cfg.x11_auth);
3486 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3487 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3488 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3489 PKT_STR, proto, PKT_STR, data,
3490 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3493 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3494 PKT_STR, proto, PKT_STR, data, PKT_END);
3499 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3500 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3501 bombout(("Protocol confusion"));
3503 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3504 logevent("X11 forwarding refused");
3506 logevent("X11 forwarding enabled");
3507 ssh->X11_fwd_enabled = TRUE;
3514 int sport,dport,sserv,dserv;
3515 char sports[256], dports[256], saddr[256], host[256];
3517 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3518 /* Add port forwardings. */
3519 ssh->portfwd_strptr = ssh->cfg.portfwd;
3520 while (*ssh->portfwd_strptr) {
3521 type = *ssh->portfwd_strptr++;
3524 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3525 if (*ssh->portfwd_strptr == ':') {
3527 * We've seen a colon in the middle of the
3528 * source port number. This means that
3529 * everything we've seen until now is the
3530 * source _address_, so we'll move it into
3531 * saddr and start sports from the beginning
3534 ssh->portfwd_strptr++;
3536 strcpy(saddr, sports);
3539 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3543 if (*ssh->portfwd_strptr == '\t')
3544 ssh->portfwd_strptr++;
3546 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3547 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3550 if (*ssh->portfwd_strptr == ':')
3551 ssh->portfwd_strptr++;
3553 while (*ssh->portfwd_strptr) {
3554 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3557 ssh->portfwd_strptr++;
3558 dport = atoi(dports);
3562 dport = net_service_lookup(dports);
3564 logeventf(ssh, "Service lookup failed for"
3565 " destination port \"%s\"", dports);
3569 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3571 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3573 sport = atoi(sports);
3577 sport = net_service_lookup(sports);
3579 logeventf(ssh, "Service lookup failed for source"
3580 " port \"%s\"", sports);
3583 if (sport && dport) {
3584 /* Set up a description of the source port. */
3585 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3586 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3587 (int)(*saddr?1:0), ":",
3588 (int)(sserv ? strlen(sports) : 0), sports,
3589 sserv, "(", sport, sserv, ")");
3591 /* Verbose description of the destination port */
3592 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3594 (int)(dserv ? strlen(dports) : 0), dports,
3595 dserv, "(", dport, dserv, ")");
3596 const char *err = pfd_addforward(host, dport,
3597 *saddr ? saddr : NULL,
3598 sport, ssh, &ssh->cfg);
3600 logeventf(ssh, "Local port %s forward to %s"
3601 " failed: %s", sportdesc, dportdesc, err);
3603 logeventf(ssh, "Local port %s forwarding to %s",
3604 sportdesc, dportdesc);
3607 } else if (type == 'D') {
3608 const char *err = pfd_addforward(NULL, -1,
3609 *saddr ? saddr : NULL,
3610 sport, ssh, &ssh->cfg);
3612 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3613 " setup failed: %s", sportdesc, err);
3615 logeventf(ssh, "Local port %s doing SOCKS"
3616 " dynamic forwarding", sportdesc);
3619 struct ssh_rportfwd *pf;
3620 pf = snew(struct ssh_rportfwd);
3621 strcpy(pf->dhost, host);
3625 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3628 if (add234(ssh->rportfwds, pf) != pf) {
3630 "Duplicate remote port forwarding to %s:%d",
3634 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3635 " forward to %s:%.*s%.*s%d%.*s",
3636 (int)(sserv ? strlen(sports) : 0), sports,
3637 sserv, "(", sport, sserv, ")",
3639 (int)(dserv ? strlen(dports) : 0), dports,
3640 dserv, "(", dport, dserv, ")");
3641 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3649 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3650 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3651 bombout(("Protocol confusion"));
3653 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3654 c_write_str(ssh, "Server refused port"
3657 logevent("Remote port forwarding enabled");
3665 if (!ssh->cfg.nopty) {
3666 /* Unpick the terminal-speed string. */
3667 /* XXX perhaps we should allow no speeds to be sent. */
3668 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3669 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
3670 /* Send the pty request. */
3671 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3672 PKT_STR, ssh->cfg.termtype,
3673 PKT_INT, ssh->term_height,
3674 PKT_INT, ssh->term_width,
3675 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
3676 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3677 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
3678 PKT_CHAR, 0, PKT_END);
3679 ssh->state = SSH_STATE_INTERMED;
3683 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3684 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3685 bombout(("Protocol confusion"));
3687 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3688 c_write_str(ssh, "Server refused to allocate pty\r\n");
3689 ssh->editing = ssh->echoing = 1;
3691 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
3692 ssh->ospeed, ssh->ispeed);
3694 ssh->editing = ssh->echoing = 1;
3697 if (ssh->cfg.compression) {
3698 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3702 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3703 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3704 bombout(("Protocol confusion"));
3706 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3707 c_write_str(ssh, "Server refused to compress\r\n");
3709 logevent("Started compression");
3710 ssh->v1_compressing = TRUE;
3711 ssh->cs_comp_ctx = zlib_compress_init();
3712 logevent("Initialised zlib (RFC1950) compression");
3713 ssh->sc_comp_ctx = zlib_decompress_init();
3714 logevent("Initialised zlib (RFC1950) decompression");
3718 * Start the shell or command.
3720 * Special case: if the first-choice command is an SSH2
3721 * subsystem (hence not usable here) and the second choice
3722 * exists, we fall straight back to that.
3725 char *cmd = ssh->cfg.remote_cmd_ptr;
3727 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3728 cmd = ssh->cfg.remote_cmd_ptr2;
3729 ssh->fallback_cmd = TRUE;
3732 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3734 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3735 logevent("Started session");
3738 ssh->state = SSH_STATE_SESSION;
3739 if (ssh->size_needed)
3740 ssh_size(ssh, ssh->term_width, ssh->term_height);
3741 if (ssh->eof_needed)
3742 ssh_special(ssh, TS_EOF);
3745 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3747 ssh->channels = newtree234(ssh_channelcmp);
3751 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3752 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3754 int stringlen, bufsize;
3756 ssh_pkt_getstring(ssh, &string, &stringlen);
3757 if (string == NULL) {
3758 bombout(("Incoming terminal data packet was badly formed"));
3763 from_backend(ssh->frontend,
3764 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3766 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3767 ssh->v1_stdout_throttling = 1;
3768 ssh1_throttle(ssh, +1);
3770 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3771 ssh_closing((Plug)ssh, NULL, 0, 0);
3772 logevent("Received disconnect request");
3774 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3775 /* Remote side is trying to open a channel to talk to our
3776 * X-Server. Give them back a local channel number. */
3777 struct ssh_channel *c;
3778 int remoteid = ssh_pkt_getuint32(ssh);
3780 logevent("Received X11 connect request");
3781 /* Refuse if X11 forwarding is disabled. */
3782 if (!ssh->X11_fwd_enabled) {
3783 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3784 PKT_INT, remoteid, PKT_END);
3785 logevent("Rejected X11 connect request");
3787 c = snew(struct ssh_channel);
3790 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3791 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3792 logevent("Opening X11 forward connection failed");
3794 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3795 PKT_INT, remoteid, PKT_END);
3798 ("Opening X11 forward connection succeeded");
3799 c->remoteid = remoteid;
3800 c->localid = alloc_channel_id(ssh);
3802 c->v.v1.throttling = 0;
3803 c->type = CHAN_X11; /* identify channel type */
3804 add234(ssh->channels, c);
3805 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3806 PKT_INT, c->remoteid, PKT_INT,
3807 c->localid, PKT_END);
3808 logevent("Opened X11 forward channel");
3811 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3812 /* Remote side is trying to open a channel to talk to our
3813 * agent. Give them back a local channel number. */
3814 struct ssh_channel *c;
3815 int remoteid = ssh_pkt_getuint32(ssh);
3817 /* Refuse if agent forwarding is disabled. */
3818 if (!ssh->agentfwd_enabled) {
3819 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3820 PKT_INT, remoteid, PKT_END);
3822 c = snew(struct ssh_channel);
3824 c->remoteid = remoteid;
3825 c->localid = alloc_channel_id(ssh);
3827 c->v.v1.throttling = 0;
3828 c->type = CHAN_AGENT; /* identify channel type */
3829 c->u.a.lensofar = 0;
3830 add234(ssh->channels, c);
3831 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3832 PKT_INT, c->remoteid, PKT_INT, c->localid,
3835 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3836 /* Remote side is trying to open a channel to talk to a
3837 * forwarded port. Give them back a local channel number. */
3838 struct ssh_channel *c;
3839 struct ssh_rportfwd pf;
3842 char *host, buf[1024];
3844 c = snew(struct ssh_channel);
3847 remoteid = ssh_pkt_getuint32(ssh);
3848 ssh_pkt_getstring(ssh, &host, &hostsize);
3849 port = ssh_pkt_getuint32(ssh);
3851 if (hostsize >= lenof(pf.dhost))
3852 hostsize = lenof(pf.dhost)-1;
3853 memcpy(pf.dhost, host, hostsize);
3854 pf.dhost[hostsize] = '\0';
3857 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3858 sprintf(buf, "Rejected remote port open request for %s:%d",
3861 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3862 PKT_INT, remoteid, PKT_END);
3864 sprintf(buf, "Received remote port open request for %s:%d",
3867 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3871 sprintf(buf, "Port open failed: %s", e);
3874 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3875 PKT_INT, remoteid, PKT_END);
3877 c->remoteid = remoteid;
3878 c->localid = alloc_channel_id(ssh);
3880 c->v.v1.throttling = 0;
3881 c->type = CHAN_SOCKDATA; /* identify channel type */
3882 add234(ssh->channels, c);
3883 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3884 PKT_INT, c->remoteid, PKT_INT,
3885 c->localid, PKT_END);
3886 logevent("Forwarded port opened successfully");
3890 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3891 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3892 unsigned int localid = ssh_pkt_getuint32(ssh);
3893 struct ssh_channel *c;
3895 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3896 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3897 c->remoteid = localid;
3898 c->type = CHAN_SOCKDATA;
3899 c->v.v1.throttling = 0;
3900 pfd_confirm(c->u.pfd.s);
3903 if (c && c->closes) {
3905 * We have a pending close on this channel,
3906 * which we decided on before the server acked
3907 * the channel open. So now we know the
3908 * remoteid, we can close it again.
3910 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3911 PKT_INT, c->remoteid, PKT_END);
3914 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3915 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3916 struct ssh_channel *c;
3918 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3919 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3920 logevent("Forwarded connection refused by server");
3921 pfd_close(c->u.pfd.s);
3922 del234(ssh->channels, c);
3926 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3927 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3928 /* Remote side closes a channel. */
3929 unsigned i = ssh_pkt_getuint32(ssh);
3930 struct ssh_channel *c;
3931 c = find234(ssh->channels, &i, ssh_channelfind);
3932 if (c && ((int)c->remoteid) != -1) {
3935 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3937 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3938 logevent("Forwarded X11 connection terminated");
3939 assert(c->u.x11.s != NULL);
3940 x11_close(c->u.x11.s);
3943 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3944 logevent("Forwarded port closed");
3945 assert(c->u.pfd.s != NULL);
3946 pfd_close(c->u.pfd.s);
3950 c->closes |= (closetype << 2); /* seen this message */
3951 if (!(c->closes & closetype)) {
3952 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3954 c->closes |= closetype; /* sent it too */
3957 if (c->closes == 15) {
3958 del234(ssh->channels, c);
3962 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3963 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3964 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3968 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3969 /* Data sent down one of our channels. */
3970 int i = ssh_pkt_getuint32(ssh);
3973 struct ssh_channel *c;
3975 ssh_pkt_getstring(ssh, &p, &len);
3977 c = find234(ssh->channels, &i, ssh_channelfind);
3982 bufsize = x11_send(c->u.x11.s, p, len);
3985 bufsize = pfd_send(c->u.pfd.s, p, len);
3988 /* Data for an agent message. Buffer it. */
3990 if (c->u.a.lensofar < 4) {
3991 int l = min(4 - c->u.a.lensofar, len);
3992 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3996 c->u.a.lensofar += l;
3998 if (c->u.a.lensofar == 4) {
4000 4 + GET_32BIT(c->u.a.msglen);
4001 c->u.a.message = snewn(c->u.a.totallen,
4003 memcpy(c->u.a.message, c->u.a.msglen, 4);
4005 if (c->u.a.lensofar >= 4 && len > 0) {
4007 min(c->u.a.totallen - c->u.a.lensofar,
4009 memcpy(c->u.a.message + c->u.a.lensofar, p,
4013 c->u.a.lensofar += l;
4015 if (c->u.a.lensofar == c->u.a.totallen) {
4018 if (agent_query(c->u.a.message,
4021 ssh_agentf_callback, c))
4022 ssh_agentf_callback(c, reply, replylen);
4023 sfree(c->u.a.message);
4024 c->u.a.lensofar = 0;
4027 bufsize = 0; /* agent channels never back up */
4030 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4031 c->v.v1.throttling = 1;
4032 ssh1_throttle(ssh, +1);
4035 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
4036 /* may be from EXEC_SHELL on some servers */
4037 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
4038 /* may be from EXEC_SHELL on some servers
4039 * if no pty is available or in other odd cases. Ignore */
4040 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
4042 ssh->exitcode = ssh_pkt_getuint32(ssh);
4043 sprintf(buf, "Server sent command exit status %d",
4046 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4048 * In case `helpful' firewalls or proxies tack
4049 * extra human-readable text on the end of the
4050 * session which we might mistake for another
4051 * encrypted packet, we close the session once
4052 * we've sent EXIT_CONFIRMATION.
4054 ssh_closing((Plug)ssh, NULL, 0, 0);
4057 bombout(("Strange packet received: type %d", ssh->pktin.type));
4062 int len = min(inlen, 512);
4063 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4064 PKT_INT, len, PKT_DATA, in, len,
4065 PKTT_OTHER, PKT_END);
4076 * Utility routine for decoding comma-separated strings in KEXINIT.
4078 static int in_commasep_string(char *needle, char *haystack, int haylen)
4081 if (!needle || !haystack) /* protect against null pointers */
4083 needlen = strlen(needle);
4086 * Is it at the start of the string?
4088 if (haylen >= needlen && /* haystack is long enough */
4089 !memcmp(needle, haystack, needlen) && /* initial match */
4090 (haylen == needlen || haystack[needlen] == ',')
4091 /* either , or EOS follows */
4095 * If not, search for the next comma and resume after that.
4096 * If no comma found, terminate.
4098 while (haylen > 0 && *haystack != ',')
4099 haylen--, haystack++;
4102 haylen--, haystack++; /* skip over comma itself */
4107 * SSH2 key creation method.
4109 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4110 unsigned char *sessid, char chr,
4111 unsigned char *keyspace)
4114 /* First 20 bytes. */
4116 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4118 SHA_Bytes(&s, H, 20);
4119 SHA_Bytes(&s, &chr, 1);
4120 SHA_Bytes(&s, sessid, 20);
4121 SHA_Final(&s, keyspace);
4122 /* Next 20 bytes. */
4124 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4126 SHA_Bytes(&s, H, 20);
4127 SHA_Bytes(&s, keyspace, 20);
4128 SHA_Final(&s, keyspace + 20);
4132 * Handle the SSH2 transport layer.
4134 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4136 struct do_ssh2_transport_state {
4137 int nbits, pbits, warn;
4138 Bignum p, g, e, f, K;
4139 int kex_init_value, kex_reply_value;
4140 const struct ssh_mac **maclist;
4142 const struct ssh2_cipher *cscipher_tobe;
4143 const struct ssh2_cipher *sccipher_tobe;
4144 const struct ssh_mac *csmac_tobe;
4145 const struct ssh_mac *scmac_tobe;
4146 const struct ssh_compress *cscomp_tobe;
4147 const struct ssh_compress *sccomp_tobe;
4148 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4149 int hostkeylen, siglen;
4150 void *hkey; /* actual host key */
4151 unsigned char exchange_hash[20];
4152 int n_preferred_ciphers;
4153 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4154 const struct ssh_compress *preferred_comp;
4157 crState(do_ssh2_transport_state);
4159 crBegin(ssh->do_ssh2_transport_crstate);
4161 s->cscipher_tobe = s->sccipher_tobe = NULL;
4162 s->csmac_tobe = s->scmac_tobe = NULL;
4163 s->cscomp_tobe = s->sccomp_tobe = NULL;
4171 * Set up the preferred ciphers. (NULL => warn below here)
4173 s->n_preferred_ciphers = 0;
4174 for (i = 0; i < CIPHER_MAX; i++) {
4175 switch (ssh->cfg.ssh_cipherlist[i]) {
4176 case CIPHER_BLOWFISH:
4177 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4180 if (ssh->cfg.ssh2_des_cbc) {
4181 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4185 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4188 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4191 /* Flag for later. Don't bother if it's the last in
4193 if (i < CIPHER_MAX - 1) {
4194 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4202 * Set up preferred compression.
4204 if (ssh->cfg.compression)
4205 s->preferred_comp = &ssh_zlib;
4207 s->preferred_comp = &ssh_comp_none;
4210 * Be prepared to work around the buggy MAC problem.
4212 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4213 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4215 s->maclist = macs, s->nmacs = lenof(macs);
4219 int i, j, cipherstr_started;
4222 * Construct and send our key exchange packet.
4224 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4225 for (i = 0; i < 16; i++)
4226 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4227 /* List key exchange algorithms. */
4228 ssh2_pkt_addstring_start(ssh);
4229 for (i = 0; i < lenof(kex_algs); i++) {
4230 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4231 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4233 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4234 if (i < lenof(kex_algs) - 1)
4235 ssh2_pkt_addstring_str(ssh, ",");
4237 /* List server host key algorithms. */
4238 ssh2_pkt_addstring_start(ssh);
4239 for (i = 0; i < lenof(hostkey_algs); i++) {
4240 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4241 if (i < lenof(hostkey_algs) - 1)
4242 ssh2_pkt_addstring_str(ssh, ",");
4244 /* List client->server encryption algorithms. */
4245 ssh2_pkt_addstring_start(ssh);
4246 cipherstr_started = 0;
4247 for (i = 0; i < s->n_preferred_ciphers; i++) {
4248 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4249 if (!c) continue; /* warning flag */
4250 for (j = 0; j < c->nciphers; j++) {
4251 if (cipherstr_started)
4252 ssh2_pkt_addstring_str(ssh, ",");
4253 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4254 cipherstr_started = 1;
4257 /* List server->client encryption algorithms. */
4258 ssh2_pkt_addstring_start(ssh);
4259 cipherstr_started = 0;
4260 for (i = 0; i < s->n_preferred_ciphers; i++) {
4261 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4262 if (!c) continue; /* warning flag */
4263 for (j = 0; j < c->nciphers; j++) {
4264 if (cipherstr_started)
4265 ssh2_pkt_addstring_str(ssh, ",");
4266 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4267 cipherstr_started = 1;
4270 /* List client->server MAC algorithms. */
4271 ssh2_pkt_addstring_start(ssh);
4272 for (i = 0; i < s->nmacs; i++) {
4273 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4274 if (i < s->nmacs - 1)
4275 ssh2_pkt_addstring_str(ssh, ",");
4277 /* List server->client MAC algorithms. */
4278 ssh2_pkt_addstring_start(ssh);
4279 for (i = 0; i < s->nmacs; i++) {
4280 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4281 if (i < s->nmacs - 1)
4282 ssh2_pkt_addstring_str(ssh, ",");
4284 /* List client->server compression algorithms. */
4285 ssh2_pkt_addstring_start(ssh);
4286 assert(lenof(compressions) > 1);
4287 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4288 for (i = 0; i < lenof(compressions); i++) {
4289 const struct ssh_compress *c = compressions[i];
4290 if (c != s->preferred_comp) {
4291 ssh2_pkt_addstring_str(ssh, ",");
4292 ssh2_pkt_addstring_str(ssh, c->name);
4295 /* List server->client compression algorithms. */
4296 ssh2_pkt_addstring_start(ssh);
4297 assert(lenof(compressions) > 1);
4298 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4299 for (i = 0; i < lenof(compressions); i++) {
4300 const struct ssh_compress *c = compressions[i];
4301 if (c != s->preferred_comp) {
4302 ssh2_pkt_addstring_str(ssh, ",");
4303 ssh2_pkt_addstring_str(ssh, c->name);
4306 /* List client->server languages. Empty list. */
4307 ssh2_pkt_addstring_start(ssh);
4308 /* List server->client languages. Empty list. */
4309 ssh2_pkt_addstring_start(ssh);
4310 /* First KEX packet does _not_ follow, because we're not that brave. */
4311 ssh2_pkt_addbool(ssh, FALSE);
4313 ssh2_pkt_adduint32(ssh, 0);
4316 ssh->exhash = ssh->exhashbase;
4317 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4323 if (ssh->pktin.length > 5)
4324 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4327 * Now examine the other side's KEXINIT to see what we're up
4334 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4335 bombout(("expected key exchange packet from server"));
4339 ssh->hostkey = NULL;
4340 s->cscipher_tobe = NULL;
4341 s->sccipher_tobe = NULL;
4342 s->csmac_tobe = NULL;
4343 s->scmac_tobe = NULL;
4344 s->cscomp_tobe = NULL;
4345 s->sccomp_tobe = NULL;
4346 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4347 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4348 for (i = 0; i < lenof(kex_algs); i++) {
4349 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4350 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4352 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4353 ssh->kex = kex_algs[i];
4357 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4358 for (i = 0; i < lenof(hostkey_algs); i++) {
4359 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4360 ssh->hostkey = hostkey_algs[i];
4364 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4366 for (i = 0; i < s->n_preferred_ciphers; i++) {
4367 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4371 for (j = 0; j < c->nciphers; j++) {
4372 if (in_commasep_string(c->list[j]->name, str, len)) {
4373 s->cscipher_tobe = c->list[j];
4378 if (s->cscipher_tobe) {
4380 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4384 if (!s->cscipher_tobe) {
4385 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4386 str ? str : "(null)"));
4390 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4392 for (i = 0; i < s->n_preferred_ciphers; i++) {
4393 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4397 for (j = 0; j < c->nciphers; j++) {
4398 if (in_commasep_string(c->list[j]->name, str, len)) {
4399 s->sccipher_tobe = c->list[j];
4404 if (s->sccipher_tobe) {
4406 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4410 if (!s->sccipher_tobe) {
4411 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4412 str ? str : "(null)"));
4416 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
4417 for (i = 0; i < s->nmacs; i++) {
4418 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4419 s->csmac_tobe = s->maclist[i];
4423 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
4424 for (i = 0; i < s->nmacs; i++) {
4425 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4426 s->scmac_tobe = s->maclist[i];
4430 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
4431 for (i = 0; i < lenof(compressions) + 1; i++) {
4432 const struct ssh_compress *c =
4433 i == 0 ? s->preferred_comp : compressions[i - 1];
4434 if (in_commasep_string(c->name, str, len)) {
4439 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
4440 for (i = 0; i < lenof(compressions) + 1; i++) {
4441 const struct ssh_compress *c =
4442 i == 0 ? s->preferred_comp : compressions[i - 1];
4443 if (in_commasep_string(c->name, str, len)) {
4451 * Work out the number of bits of key we will need from the key
4452 * exchange. We start with the maximum key length of either
4458 csbits = s->cscipher_tobe->keylen;
4459 scbits = s->sccipher_tobe->keylen;
4460 s->nbits = (csbits > scbits ? csbits : scbits);
4462 /* The keys only have 160-bit entropy, since they're based on
4463 * a SHA-1 hash. So cap the key size at 160 bits. */
4468 * If we're doing Diffie-Hellman group exchange, start by
4469 * requesting a group.
4471 if (ssh->kex == &ssh_diffiehellman_gex) {
4472 logevent("Doing Diffie-Hellman group exchange");
4473 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4475 * Work out how big a DH group we will need to allow that
4478 s->pbits = 512 << ((s->nbits - 1) / 64);
4479 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4480 ssh2_pkt_adduint32(ssh, s->pbits);
4484 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4485 bombout(("expected key exchange group packet from server"));
4488 s->p = ssh2_pkt_getmp(ssh);
4489 s->g = ssh2_pkt_getmp(ssh);
4490 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4491 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4492 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4494 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4495 ssh->kex_ctx = dh_setup_group1();
4496 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4497 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4500 logevent("Doing Diffie-Hellman key exchange");
4502 * Now generate and send e for Diffie-Hellman.
4504 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4505 ssh2_pkt_init(ssh, s->kex_init_value);
4506 ssh2_pkt_addmp(ssh, s->e);
4510 if (ssh->pktin.type != s->kex_reply_value) {
4511 bombout(("expected key exchange reply packet from server"));
4514 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4515 s->f = ssh2_pkt_getmp(ssh);
4516 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4518 s->K = dh_find_K(ssh->kex_ctx, s->f);
4520 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4521 if (ssh->kex == &ssh_diffiehellman_gex) {
4522 sha_uint32(&ssh->exhash, s->pbits);
4523 sha_mpint(&ssh->exhash, s->p);
4524 sha_mpint(&ssh->exhash, s->g);
4526 sha_mpint(&ssh->exhash, s->e);
4527 sha_mpint(&ssh->exhash, s->f);
4528 sha_mpint(&ssh->exhash, s->K);
4529 SHA_Final(&ssh->exhash, s->exchange_hash);
4531 dh_cleanup(ssh->kex_ctx);
4532 ssh->kex_ctx = NULL;
4535 debug(("Exchange hash is:\n"));
4536 dmemdump(s->exchange_hash, 20);
4539 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4541 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4542 (char *)s->exchange_hash, 20)) {
4543 bombout(("Server's host key did not match the signature supplied"));
4548 * Authenticate remote host: verify host key. (We've already
4549 * checked the signature of the exchange hash.)
4551 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4552 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4553 verify_ssh_host_key(ssh->frontend,
4554 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4555 s->keystr, s->fingerprint);
4556 if (s->first_kex) { /* don't bother logging this in rekeys */
4557 logevent("Host key fingerprint is:");
4558 logevent(s->fingerprint);
4560 sfree(s->fingerprint);
4562 ssh->hostkey->freekey(s->hkey);
4565 * Send SSH2_MSG_NEWKEYS.
4567 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4571 * Expect SSH2_MSG_NEWKEYS from server.
4574 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4575 bombout(("expected new-keys packet from server"));
4580 * Create and initialise session keys.
4582 if (ssh->cs_cipher_ctx)
4583 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4584 ssh->cscipher = s->cscipher_tobe;
4585 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4587 if (ssh->sc_cipher_ctx)
4588 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4589 ssh->sccipher = s->sccipher_tobe;
4590 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4592 if (ssh->cs_mac_ctx)
4593 ssh->csmac->free_context(ssh->cs_mac_ctx);
4594 ssh->csmac = s->csmac_tobe;
4595 ssh->cs_mac_ctx = ssh->csmac->make_context();
4597 if (ssh->sc_mac_ctx)
4598 ssh->scmac->free_context(ssh->sc_mac_ctx);
4599 ssh->scmac = s->scmac_tobe;
4600 ssh->sc_mac_ctx = ssh->scmac->make_context();
4602 if (ssh->cs_comp_ctx)
4603 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4604 ssh->cscomp = s->cscomp_tobe;
4605 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4607 if (ssh->sc_comp_ctx)
4608 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4609 ssh->sccomp = s->sccomp_tobe;
4610 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4613 * Set IVs after keys. Here we use the exchange hash from the
4614 * _first_ key exchange.
4617 unsigned char keyspace[40];
4619 memcpy(ssh->v2_session_id, s->exchange_hash,
4620 sizeof(s->exchange_hash));
4621 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4622 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4623 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4624 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4625 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4626 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4627 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4628 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4629 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4630 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4631 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4632 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4634 logeventf(ssh, "Initialised %.200s client->server encryption",
4635 ssh->cscipher->text_name);
4636 logeventf(ssh, "Initialised %.200s server->client encryption",
4637 ssh->sccipher->text_name);
4638 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4639 ssh->csmac->text_name);
4640 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4641 ssh->scmac->text_name);
4642 if (ssh->cscomp->text_name)
4643 logeventf(ssh, "Initialised %s compression",
4644 ssh->cscomp->text_name);
4645 if (ssh->sccomp->text_name)
4646 logeventf(ssh, "Initialised %s decompression",
4647 ssh->sccomp->text_name);
4650 if (ssh->kex == &ssh_diffiehellman_gex) {
4656 * If this is the first key exchange phase, we must pass the
4657 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4658 * wants to see it but because it will need time to initialise
4659 * itself before it sees an actual packet. In subsequent key
4660 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4661 * it would only confuse the layer above.
4663 if (!s->first_kex) {
4669 * Now we're encrypting. Begin returning 1 to the protocol main
4670 * function so that other things can run on top of the
4671 * transport. If we ever see a KEXINIT, we must go back to the
4674 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4677 logevent("Server initiated key re-exchange");
4678 goto begin_key_exchange;
4684 * Add data to an SSH2 channel output buffer.
4686 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4689 bufchain_add(&c->v.v2.outbuffer, buf, len);
4693 * Attempt to send data on an SSH2 channel.
4695 static int ssh2_try_send(struct ssh_channel *c)
4699 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4702 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4703 if ((unsigned)len > c->v.v2.remwindow)
4704 len = c->v.v2.remwindow;
4705 if ((unsigned)len > c->v.v2.remmaxpkt)
4706 len = c->v.v2.remmaxpkt;
4707 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4708 ssh2_pkt_adduint32(ssh, c->remoteid);
4709 dont_log_data(ssh, PKTLOG_OMIT);
4710 ssh2_pkt_addstring_start(ssh);
4711 ssh2_pkt_addstring_data(ssh, data, len);
4712 end_log_omission(ssh);
4714 bufchain_consume(&c->v.v2.outbuffer, len);
4715 c->v.v2.remwindow -= len;
4719 * After having sent as much data as we can, return the amount
4722 return bufchain_size(&c->v.v2.outbuffer);
4726 * Potentially enlarge the window on an SSH2 channel.
4728 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4733 * Never send WINDOW_ADJUST for a channel that the remote side
4734 * already thinks it's closed; there's no point, since it won't
4735 * be sending any more data anyway.
4740 if (newwin > c->v.v2.locwindow) {
4741 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4742 ssh2_pkt_adduint32(ssh, c->remoteid);
4743 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4745 c->v.v2.locwindow = newwin;
4750 * Handle the SSH2 userauth and connection layers.
4752 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4754 struct do_ssh2_authconn_state {
4756 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4758 AUTH_KEYBOARD_INTERACTIVE
4762 AUTH_TYPE_PUBLICKEY,
4763 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4764 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4766 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4767 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4769 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4770 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4771 int kbd_inter_running;
4773 int num_prompts, curr_prompt, echo;
4778 void *publickey_blob;
4779 int publickey_bloblen;
4780 unsigned char request[5], *response, *p;
4784 char *pkblob, *alg, *commentp;
4785 int pklen, alglen, commentlen;
4786 int siglen, retlen, len;
4787 char *q, *agentreq, *ret;
4789 int num_env, env_left, env_ok;
4791 crState(do_ssh2_authconn_state);
4793 crBegin(ssh->do_ssh2_authconn_crstate);
4796 * Request userauth protocol, and await a response to it.
4798 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4799 ssh2_pkt_addstring(ssh, "ssh-userauth");
4801 crWaitUntilV(ispkt);
4802 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4803 bombout(("Server refused user authentication protocol"));
4808 * We repeat this whole loop, including the username prompt,
4809 * until we manage a successful authentication. If the user
4810 * types the wrong _password_, they can be sent back to the
4811 * beginning to try another username, if this is configured on.
4812 * (If they specify a username in the config, they are never
4813 * asked, even if they do give a wrong password.)
4815 * I think this best serves the needs of
4817 * - the people who have no configuration, no keys, and just
4818 * want to try repeated (username,password) pairs until they
4819 * type both correctly
4821 * - people who have keys and configuration but occasionally
4822 * need to fall back to passwords
4824 * - people with a key held in Pageant, who might not have
4825 * logged in to a particular machine before; so they want to
4826 * type a username, and then _either_ their key will be
4827 * accepted, _or_ they will type a password. If they mistype
4828 * the username they will want to be able to get back and
4831 s->username[0] = '\0';
4832 s->got_username = FALSE;
4837 if (s->got_username && !ssh->cfg.change_username) {
4839 * We got a username last time round this loop, and
4840 * with change_username turned off we don't try to get
4843 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4844 if (ssh_get_line && !ssh_getline_pw_only) {
4845 if (!ssh_get_line("login as: ",
4846 s->username, sizeof(s->username), FALSE)) {
4848 * get_line failed to get a username.
4851 logevent("No username provided. Abandoning session.");
4852 ssh_closing((Plug)ssh, NULL, 0, 0);
4856 int ret; /* need not be saved across crReturn */
4857 c_write_str(ssh, "login as: ");
4859 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4861 crWaitUntilV(!ispkt);
4862 ret = process_userpass_input(ssh, in, inlen);
4866 c_write_str(ssh, "\r\n");
4868 s->username[strcspn(s->username, "\n\r")] = '\0';
4871 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4872 s->username[sizeof(s->username)-1] = '\0';
4873 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4874 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4875 c_write_str(ssh, stuff);
4879 s->got_username = TRUE;
4882 * Send an authentication request using method "none": (a)
4883 * just in case it succeeds, and (b) so that we know what
4884 * authentication methods we can usefully try next.
4886 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4888 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4889 ssh2_pkt_addstring(ssh, s->username);
4890 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4891 ssh2_pkt_addstring(ssh, "none"); /* method */
4893 s->type = AUTH_TYPE_NONE;
4895 s->we_are_in = FALSE;
4897 s->tried_pubkey_config = FALSE;
4898 s->tried_agent = FALSE;
4899 s->tried_keyb_inter = FALSE;
4900 s->kbd_inter_running = FALSE;
4901 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4902 if (!filename_is_null(ssh->cfg.keyfile)) {
4904 logeventf(ssh, "Reading private key file \"%.150s\"",
4905 filename_to_str(&ssh->cfg.keyfile));
4906 keytype = key_type(&ssh->cfg.keyfile);
4907 if (keytype == SSH_KEYTYPE_SSH2) {
4909 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4910 &s->publickey_bloblen, NULL);
4913 logeventf(ssh, "Unable to use this key file (%s)",
4914 key_type_to_str(keytype));
4915 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4917 filename_to_str(&ssh->cfg.keyfile),
4918 key_type_to_str(keytype));
4919 c_write_str(ssh, msgbuf);
4921 s->publickey_blob = NULL;
4924 s->publickey_blob = NULL;
4928 * Wait for the result of the last authentication request.
4931 crWaitUntilV(ispkt);
4932 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4936 * Don't show the banner if we're operating in
4937 * non-verbose non-interactive mode. (It's probably
4938 * a script, which means nobody will read the
4939 * banner _anyway_, and moreover the printing of
4940 * the banner will screw up processing on the
4941 * output of (say) plink.)
4943 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4944 ssh_pkt_getstring(ssh, &banner, &size);
4946 c_write_untrusted(ssh, banner, size);
4948 crWaitUntilV(ispkt);
4950 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4951 logevent("Access granted");
4952 s->we_are_in = TRUE;
4956 if (s->kbd_inter_running &&
4957 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4959 * This is either a further set-of-prompts packet
4960 * in keyboard-interactive authentication, or it's
4961 * the same one and we came back here with `gotit'
4962 * set. In the former case, we must reset the
4963 * curr_prompt variable.
4967 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4968 bombout(("Strange packet received during authentication: type %d",
4976 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4977 * we can look at the string in it and know what we can
4978 * helpfully try next.
4980 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4983 ssh_pkt_getstring(ssh, &methods, &methlen);
4984 s->kbd_inter_running = FALSE;
4985 if (!ssh2_pkt_getbool(ssh)) {
4987 * We have received an unequivocal Access
4988 * Denied. This can translate to a variety of
4991 * - if we'd just tried "none" authentication,
4992 * it's not worth printing anything at all
4994 * - if we'd just tried a public key _offer_,
4995 * the message should be "Server refused our
4996 * key" (or no message at all if the key
4997 * came from Pageant)
4999 * - if we'd just tried anything else, the
5000 * message really should be "Access denied".
5002 * Additionally, if we'd just tried password
5003 * authentication, we should break out of this
5004 * whole loop so as to go back to the username
5007 if (s->type == AUTH_TYPE_NONE) {
5009 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5010 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5011 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5012 c_write_str(ssh, "Server refused our key\r\n");
5013 logevent("Server refused public key");
5014 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5015 /* server declined keyboard-interactive; ignore */
5017 c_write_str(ssh, "Access denied\r\n");
5018 logevent("Access denied");
5019 if (s->type == AUTH_TYPE_PASSWORD) {
5020 s->we_are_in = FALSE;
5025 c_write_str(ssh, "Further authentication required\r\n");
5026 logevent("Further authentication required");
5030 in_commasep_string("publickey", methods, methlen);
5032 in_commasep_string("password", methods, methlen);
5033 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5034 in_commasep_string("keyboard-interactive", methods, methlen);
5038 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5042 * Most password/passphrase prompts will be
5043 * non-echoing, so we set this to 0 by default.
5044 * Exception is that some keyboard-interactive prompts
5045 * can be echoing, in which case we'll set this to 1.
5049 if (!s->method && s->can_pubkey &&
5050 agent_exists() && !s->tried_agent) {
5052 * Attempt public-key authentication using Pageant.
5057 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5058 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5060 s->tried_agent = TRUE;
5062 logevent("Pageant is running. Requesting keys.");
5064 /* Request the keys held by the agent. */
5065 PUT_32BIT(s->request, 1);
5066 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5067 if (!agent_query(s->request, 5, &r, &s->responselen,
5068 ssh_agent_callback, ssh)) {
5072 bombout(("Unexpected data from server while"
5073 " waiting for agent response"));
5076 } while (ispkt || inlen > 0);
5077 r = ssh->agent_response;
5078 s->responselen = ssh->agent_response_len;
5080 s->response = (unsigned char *) r;
5081 if (s->response && s->responselen >= 5 &&
5082 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5083 s->p = s->response + 5;
5084 s->nkeys = GET_32BIT(s->p);
5088 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5091 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5096 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5099 s->pklen = GET_32BIT(s->p);
5101 if (s->publickey_blob &&
5102 s->pklen == s->publickey_bloblen &&
5103 !memcmp(s->p, s->publickey_blob,
5104 s->publickey_bloblen)) {
5105 logevent("This key matches configured key file");
5106 s->tried_pubkey_config = 1;
5108 s->pkblob = (char *)s->p;
5110 s->alglen = GET_32BIT(s->pkblob);
5111 s->alg = s->pkblob + 4;
5112 s->commentlen = GET_32BIT(s->p);
5114 s->commentp = (char *)s->p;
5115 s->p += s->commentlen;
5116 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5117 ssh2_pkt_addstring(ssh, s->username);
5118 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5119 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5120 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5121 ssh2_pkt_addstring_start(ssh);
5122 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5123 ssh2_pkt_addstring_start(ssh);
5124 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5127 crWaitUntilV(ispkt);
5128 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5129 logevent("Key refused");
5133 if (flags & FLAG_VERBOSE) {
5134 c_write_str(ssh, "Authenticating with "
5136 c_write(ssh, s->commentp, s->commentlen);
5137 c_write_str(ssh, "\" from agent\r\n");
5141 * Server is willing to accept the key.
5142 * Construct a SIGN_REQUEST.
5144 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5145 ssh2_pkt_addstring(ssh, s->username);
5146 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5147 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5148 ssh2_pkt_addbool(ssh, TRUE);
5149 ssh2_pkt_addstring_start(ssh);
5150 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5151 ssh2_pkt_addstring_start(ssh);
5152 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5154 s->siglen = ssh->pktout.length - 5 + 4 + 20;
5155 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5157 s->len = 1; /* message type */
5158 s->len += 4 + s->pklen; /* key blob */
5159 s->len += 4 + s->siglen; /* data to sign */
5160 s->len += 4; /* flags */
5161 s->agentreq = snewn(4 + s->len, char);
5162 PUT_32BIT(s->agentreq, s->len);
5163 s->q = s->agentreq + 4;
5164 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5165 PUT_32BIT(s->q, s->pklen);
5167 memcpy(s->q, s->pkblob, s->pklen);
5169 PUT_32BIT(s->q, s->siglen);
5171 /* Now the data to be signed... */
5172 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5173 PUT_32BIT(s->q, 20);
5176 memcpy(s->q, ssh->v2_session_id, 20);
5178 memcpy(s->q, ssh->pktout.data + 5,
5179 ssh->pktout.length - 5);
5180 s->q += ssh->pktout.length - 5;
5181 /* And finally the (zero) flags word. */
5183 if (!agent_query(s->agentreq, s->len + 4,
5185 ssh_agent_callback, ssh)) {
5189 bombout(("Unexpected data from server"
5190 " while waiting for agent"
5194 } while (ispkt || inlen > 0);
5195 vret = ssh->agent_response;
5196 s->retlen = ssh->agent_response_len;
5201 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5202 logevent("Sending Pageant's response");
5203 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5205 GET_32BIT(s->ret + 5));
5211 ("Pageant failed to answer challenge");
5222 if (!s->method && s->can_pubkey && s->publickey_blob
5223 && !s->tried_pubkey_config) {
5224 unsigned char *pub_blob;
5225 char *algorithm, *comment;
5228 s->tried_pubkey_config = TRUE;
5230 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5231 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5234 * Try the public key supplied in the configuration.
5236 * First, offer the public blob to see if the server is
5237 * willing to accept it.
5240 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
5245 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5246 ssh2_pkt_addstring(ssh, s->username);
5247 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5248 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5249 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5250 ssh2_pkt_addstring(ssh, algorithm);
5251 ssh2_pkt_addstring_start(ssh);
5252 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5255 logevent("Offered public key");
5257 crWaitUntilV(ispkt);
5258 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5260 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
5261 continue; /* key refused; give up on it */
5264 logevent("Offer of public key accepted");
5266 * Actually attempt a serious authentication using
5269 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
5270 sprintf(s->pwprompt,
5271 "Passphrase for key \"%.100s\": ",
5277 if (flags & FLAG_VERBOSE) {
5278 c_write_str(ssh, "Authenticating with public key \"");
5279 c_write_str(ssh, comment);
5280 c_write_str(ssh, "\"\r\n");
5282 s->method = AUTH_PUBLICKEY_FILE;
5286 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5287 s->method = AUTH_KEYBOARD_INTERACTIVE;
5288 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5289 s->tried_keyb_inter = TRUE;
5291 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5292 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5294 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5295 ssh2_pkt_addstring(ssh, s->username);
5296 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5297 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5298 ssh2_pkt_addstring(ssh, ""); /* lang */
5299 ssh2_pkt_addstring(ssh, "");
5302 crWaitUntilV(ispkt);
5303 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5304 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5306 logevent("Keyboard-interactive authentication refused");
5307 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5311 s->kbd_inter_running = TRUE;
5315 if (s->kbd_inter_running) {
5316 s->method = AUTH_KEYBOARD_INTERACTIVE;
5317 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5318 s->tried_keyb_inter = TRUE;
5320 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5321 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5323 if (s->curr_prompt == 0) {
5325 * We've got a fresh USERAUTH_INFO_REQUEST.
5326 * Display header data, and start going through
5329 char *name, *inst, *lang;
5330 int name_len, inst_len, lang_len;
5332 ssh_pkt_getstring(ssh, &name, &name_len);
5333 ssh_pkt_getstring(ssh, &inst, &inst_len);
5334 ssh_pkt_getstring(ssh, &lang, &lang_len);
5336 c_write_untrusted(ssh, name, name_len);
5337 c_write_str(ssh, "\r\n");
5340 c_write_untrusted(ssh, inst, inst_len);
5341 c_write_str(ssh, "\r\n");
5343 s->num_prompts = ssh_pkt_getuint32(ssh);
5347 * If there are prompts remaining in the packet,
5348 * display one and get a response.
5350 if (s->curr_prompt < s->num_prompts) {
5354 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
5355 if (prompt_len > 0) {
5356 static const char trunc[] = "<prompt truncated>: ";
5357 static const int prlen = sizeof(s->pwprompt) -
5359 if (prompt_len > prlen) {
5360 memcpy(s->pwprompt, prompt, prlen);
5361 strcpy(s->pwprompt + prlen, trunc);
5363 memcpy(s->pwprompt, prompt, prompt_len);
5364 s->pwprompt[prompt_len] = '\0';
5368 "<server failed to send prompt>: ");
5370 s->echo = ssh2_pkt_getbool(ssh);
5376 if (!s->method && s->can_passwd) {
5377 s->method = AUTH_PASSWORD;
5378 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5379 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5380 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5387 if (!ssh_get_line(s->pwprompt, s->password,
5388 sizeof(s->password), TRUE)) {
5390 * get_line failed to get a password (for
5391 * example because one was supplied on the
5392 * command line which has already failed to
5395 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5396 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5397 ssh2_pkt_addstring(ssh, "No more passwords available"
5399 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5401 logevent("Unable to authenticate");
5402 connection_fatal(ssh->frontend,
5403 "Unable to authenticate");
5404 ssh_closing((Plug)ssh, NULL, 0, 0);
5408 int ret; /* need not be saved across crReturn */
5409 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5412 setup_userpass_input(ssh, s->password,
5413 sizeof(s->password), s->echo);
5415 crWaitUntilV(!ispkt);
5416 ret = process_userpass_input(ssh, in, inlen);
5420 c_write_str(ssh, "\r\n");
5424 if (s->method == AUTH_PUBLICKEY_FILE) {
5426 * We have our passphrase. Now try the actual authentication.
5428 struct ssh2_userkey *key;
5429 const char *error = NULL;
5431 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5433 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5434 if (key == SSH2_WRONG_PASSPHRASE) {
5435 c_write_str(ssh, "Wrong passphrase\r\n");
5436 s->tried_pubkey_config = FALSE;
5438 c_write_str(ssh, "Unable to load private key (");
5439 c_write_str(ssh, error);
5440 c_write_str(ssh, ")\r\n");
5441 s->tried_pubkey_config = TRUE;
5443 /* Send a spurious AUTH_NONE to return to the top. */
5444 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5445 ssh2_pkt_addstring(ssh, s->username);
5446 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5447 ssh2_pkt_addstring(ssh, "none"); /* method */
5449 s->type = AUTH_TYPE_NONE;
5451 unsigned char *pkblob, *sigblob, *sigdata;
5452 int pkblob_len, sigblob_len, sigdata_len;
5456 * We have loaded the private key and the server
5457 * has announced that it's willing to accept it.
5458 * Hallelujah. Generate a signature and send it.
5460 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5461 ssh2_pkt_addstring(ssh, s->username);
5462 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5463 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5464 ssh2_pkt_addbool(ssh, TRUE);
5465 ssh2_pkt_addstring(ssh, key->alg->name);
5466 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5467 ssh2_pkt_addstring_start(ssh);
5468 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5471 * The data to be signed is:
5475 * followed by everything so far placed in the
5478 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5479 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5481 sigdata = snewn(sigdata_len, unsigned char);
5483 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5484 PUT_32BIT(sigdata+p, 20);
5487 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5488 memcpy(sigdata+p, ssh->pktout.data + 5,
5489 ssh->pktout.length - 5);
5490 p += ssh->pktout.length - 5;
5491 assert(p == sigdata_len);
5492 sigblob = key->alg->sign(key->data, (char *)sigdata,
5493 sigdata_len, &sigblob_len);
5494 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5495 sigblob, sigblob_len);
5501 s->type = AUTH_TYPE_PUBLICKEY;
5502 key->alg->freekey(key->data);
5504 } else if (s->method == AUTH_PASSWORD) {
5506 * We send the password packet lumped tightly together with
5507 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5508 * string long enough to make the total length of the two
5509 * packets constant. This should ensure that a passive
5510 * listener doing traffic analyis can't work out the length
5513 * For this to work, we need an assumption about the
5514 * maximum length of the password packet. I think 256 is
5515 * pretty conservative. Anyone using a password longer than
5516 * that probably doesn't have much to worry about from
5517 * people who find out how long their password is!
5519 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5520 ssh2_pkt_addstring(ssh, s->username);
5521 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5522 ssh2_pkt_addstring(ssh, "password");
5523 ssh2_pkt_addbool(ssh, FALSE);
5524 dont_log_password(ssh, PKTLOG_BLANK);
5525 ssh2_pkt_addstring(ssh, s->password);
5526 memset(s->password, 0, sizeof(s->password));
5527 end_log_omission(ssh);
5528 ssh2_pkt_defer(ssh);
5530 * We'll include a string that's an exact multiple of the
5531 * cipher block size. If the cipher is NULL for some
5532 * reason, we don't do this trick at all because we gain
5535 if (ssh->cscipher) {
5538 stringlen = (256 - ssh->deferred_len);
5539 stringlen += ssh->cscipher->blksize - 1;
5540 stringlen -= (stringlen % ssh->cscipher->blksize);
5543 * Temporarily disable actual compression,
5544 * so we can guarantee to get this string
5545 * exactly the length we want it. The
5546 * compression-disabling routine should
5547 * return an integer indicating how many
5548 * bytes we should adjust our string length
5552 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5554 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5555 ssh2_pkt_addstring_start(ssh);
5556 for (i = 0; i < stringlen; i++) {
5557 char c = (char) random_byte();
5558 ssh2_pkt_addstring_data(ssh, &c, 1);
5560 ssh2_pkt_defer(ssh);
5562 ssh_pkt_defersend(ssh);
5563 logevent("Sent password");
5564 s->type = AUTH_TYPE_PASSWORD;
5565 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5566 if (s->curr_prompt == 0) {
5567 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5568 ssh2_pkt_adduint32(ssh, s->num_prompts);
5570 if (s->need_pw) { /* only add pw if we just got one! */
5571 dont_log_password(ssh, PKTLOG_BLANK);
5572 ssh2_pkt_addstring(ssh, s->password);
5573 memset(s->password, 0, sizeof(s->password));
5574 end_log_omission(ssh);
5577 if (s->curr_prompt >= s->num_prompts) {
5581 * If there are prompts remaining, we set
5582 * `gotit' so that we won't attempt to get
5583 * another packet. Then we go back round the
5584 * loop and will end up retrieving another
5585 * prompt out of the existing packet. Funky or
5590 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5592 c_write_str(ssh, "No supported authentication methods"
5593 " left to try!\r\n");
5594 logevent("No supported authentications offered."
5596 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5597 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5598 ssh2_pkt_addstring(ssh, "No supported authentication"
5599 " methods available");
5600 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5602 ssh_closing((Plug)ssh, NULL, 0, 0);
5606 } while (!s->we_are_in);
5609 * Now we're authenticated for the connection protocol. The
5610 * connection protocol will automatically have started at this
5611 * point; there's no need to send SERVICE_REQUEST.
5614 ssh->channels = newtree234(ssh_channelcmp);
5617 * Create the main session channel.
5619 if (!ssh->cfg.ssh_no_shell) {
5620 ssh->mainchan = snew(struct ssh_channel);
5621 ssh->mainchan->ssh = ssh;
5622 ssh->mainchan->localid = alloc_channel_id(ssh);
5623 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5624 ssh2_pkt_addstring(ssh, "session");
5625 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5626 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5627 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5628 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5630 crWaitUntilV(ispkt);
5631 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5632 bombout(("Server refused to open a session"));
5634 /* FIXME: error data comes back in FAILURE packet */
5636 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5637 bombout(("Server's channel confirmation cited wrong channel"));
5640 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5641 ssh->mainchan->type = CHAN_MAINSESSION;
5642 ssh->mainchan->closes = 0;
5643 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5644 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5645 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5646 add234(ssh->channels, ssh->mainchan);
5647 update_specials_menu(ssh->frontend);
5648 logevent("Opened channel for session");
5650 ssh->mainchan = NULL;
5653 * Potentially enable X11 forwarding.
5655 if (ssh->mainchan && ssh->cfg.x11_forward) {
5656 char proto[20], data[64];
5657 logevent("Requesting X11 forwarding");
5658 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5659 data, sizeof(data), ssh->cfg.x11_auth);
5660 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5661 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5662 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5663 ssh2_pkt_addstring(ssh, "x11-req");
5664 ssh2_pkt_addbool(ssh, 1); /* want reply */
5665 ssh2_pkt_addbool(ssh, 0); /* many connections */
5666 ssh2_pkt_addstring(ssh, proto);
5667 ssh2_pkt_addstring(ssh, data);
5668 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5672 crWaitUntilV(ispkt);
5673 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5674 unsigned i = ssh_pkt_getuint32(ssh);
5675 struct ssh_channel *c;
5676 c = find234(ssh->channels, &i, ssh_channelfind);
5678 continue; /* nonexistent channel */
5679 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5681 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5683 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5684 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5685 bombout(("Unexpected response to X11 forwarding request:"
5686 " packet type %d", ssh->pktin.type));
5689 logevent("X11 forwarding refused");
5691 logevent("X11 forwarding enabled");
5692 ssh->X11_fwd_enabled = TRUE;
5697 * Enable port forwardings.
5702 int sport,dport,sserv,dserv;
5703 char sports[256], dports[256], saddr[256], host[256];
5705 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5706 /* Add port forwardings. */
5707 ssh->portfwd_strptr = ssh->cfg.portfwd;
5708 while (*ssh->portfwd_strptr) {
5709 type = *ssh->portfwd_strptr++;
5712 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5713 if (*ssh->portfwd_strptr == ':') {
5715 * We've seen a colon in the middle of the
5716 * source port number. This means that
5717 * everything we've seen until now is the
5718 * source _address_, so we'll move it into
5719 * saddr and start sports from the beginning
5722 ssh->portfwd_strptr++;
5724 strcpy(saddr, sports);
5727 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5731 if (*ssh->portfwd_strptr == '\t')
5732 ssh->portfwd_strptr++;
5734 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5735 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5738 if (*ssh->portfwd_strptr == ':')
5739 ssh->portfwd_strptr++;
5741 while (*ssh->portfwd_strptr) {
5742 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5745 ssh->portfwd_strptr++;
5746 dport = atoi(dports);
5750 dport = net_service_lookup(dports);
5752 logeventf(ssh, "Service lookup failed for destination"
5753 " port \"%s\"", dports);
5757 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5759 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5761 sport = atoi(sports);
5765 sport = net_service_lookup(sports);
5767 logeventf(ssh, "Service lookup failed for source"
5768 " port \"%s\"", sports);
5771 if (sport && dport) {
5772 /* Set up a description of the source port. */
5773 static char *sportdesc;
5774 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
5775 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5776 (int)(*saddr?1:0), ":",
5777 (int)(sserv ? strlen(sports) : 0), sports,
5778 sserv, "(", sport, sserv, ")");
5780 /* Verbose description of the destination port */
5781 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
5783 (int)(dserv ? strlen(dports) : 0), dports,
5784 dserv, "(", dport, dserv, ")");
5785 const char *err = pfd_addforward(host, dport,
5786 *saddr ? saddr : NULL,
5787 sport, ssh, &ssh->cfg);
5789 logeventf(ssh, "Local port %s forward to %s"
5790 " failed: %s", sportdesc, dportdesc, err);
5792 logeventf(ssh, "Local port %s forwarding to %s",
5793 sportdesc, dportdesc);
5796 } else if (type == 'D') {
5797 const char *err = pfd_addforward(NULL, -1,
5798 *saddr ? saddr : NULL,
5799 sport, ssh, &ssh->cfg);
5801 logeventf(ssh, "Local port %s SOCKS dynamic forward"
5802 " setup failed: %s", sportdesc, err);
5804 logeventf(ssh, "Local port %s doing SOCKS"
5805 " dynamic forwarding", sportdesc);
5808 struct ssh_rportfwd *pf;
5809 pf = snew(struct ssh_rportfwd);
5810 strcpy(pf->dhost, host);
5813 if (add234(ssh->rportfwds, pf) != pf) {
5814 logeventf(ssh, "Duplicate remote port forwarding"
5815 " to %s:%d", host, dport);
5818 logeventf(ssh, "Requesting remote port %s"
5819 " forward to %s:%.*s%.*s%d%.*s",
5822 (int)(dserv ? strlen(dports) : 0), dports,
5823 dserv, "(", dport, dserv, ")");
5824 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5825 ssh2_pkt_addstring(ssh, "tcpip-forward");
5826 ssh2_pkt_addbool(ssh, 1);/* want reply */
5828 ssh2_pkt_addstring(ssh, saddr);
5829 } else if (ssh->cfg.rport_acceptall) {
5830 ssh2_pkt_addstring(ssh, "0.0.0.0");
5832 ssh2_pkt_addstring(ssh, "127.0.0.1");
5834 ssh2_pkt_adduint32(ssh, sport);
5838 crWaitUntilV(ispkt);
5839 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5840 unsigned i = ssh_pkt_getuint32(ssh);
5841 struct ssh_channel *c;
5842 c = find234(ssh->channels, &i, ssh_channelfind);
5844 continue;/* nonexistent channel */
5845 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5847 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5849 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5850 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5851 bombout(("Unexpected response to port "
5852 "forwarding request: packet type %d",
5856 logevent("Server refused this port forwarding");
5858 logevent("Remote port forwarding enabled");
5868 * Potentially enable agent forwarding.
5870 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
5871 logevent("Requesting OpenSSH-style agent forwarding");
5872 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5873 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5874 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5875 ssh2_pkt_addbool(ssh, 1); /* want reply */
5879 crWaitUntilV(ispkt);
5880 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5881 unsigned i = ssh_pkt_getuint32(ssh);
5882 struct ssh_channel *c;
5883 c = find234(ssh->channels, &i, ssh_channelfind);
5885 continue; /* nonexistent channel */
5886 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5888 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5890 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5891 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5892 bombout(("Unexpected response to agent forwarding request:"
5893 " packet type %d", ssh->pktin.type));
5896 logevent("Agent forwarding refused");
5898 logevent("Agent forwarding enabled");
5899 ssh->agentfwd_enabled = TRUE;
5904 * Now allocate a pty for the session.
5906 if (ssh->mainchan && !ssh->cfg.nopty) {
5907 /* Unpick the terminal-speed string. */
5908 /* XXX perhaps we should allow no speeds to be sent. */
5909 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5910 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5911 /* Build the pty request. */
5912 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5913 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5914 ssh2_pkt_addstring(ssh, "pty-req");
5915 ssh2_pkt_addbool(ssh, 1); /* want reply */
5916 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5917 ssh2_pkt_adduint32(ssh, ssh->term_width);
5918 ssh2_pkt_adduint32(ssh, ssh->term_height);
5919 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5920 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5921 ssh2_pkt_addstring_start(ssh);
5922 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
5923 ssh2_pkt_adduint32(ssh, ssh->ispeed);
5924 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
5925 ssh2_pkt_adduint32(ssh, ssh->ospeed);
5926 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
5928 ssh->state = SSH_STATE_INTERMED;
5931 crWaitUntilV(ispkt);
5932 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5933 unsigned i = ssh_pkt_getuint32(ssh);
5934 struct ssh_channel *c;
5935 c = find234(ssh->channels, &i, ssh_channelfind);
5937 continue; /* nonexistent channel */
5938 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5940 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5942 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5943 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5944 bombout(("Unexpected response to pty request:"
5945 " packet type %d", ssh->pktin.type));
5948 c_write_str(ssh, "Server refused to allocate pty\r\n");
5949 ssh->editing = ssh->echoing = 1;
5951 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5952 ssh->ospeed, ssh->ispeed);
5955 ssh->editing = ssh->echoing = 1;
5959 * Send environment variables.
5961 * Simplest thing here is to send all the requests at once, and
5962 * then wait for a whole bunch of successes or failures.
5964 if (ssh->mainchan && *ssh->cfg.environmt) {
5965 char *e = ssh->cfg.environmt;
5966 char *var, *varend, *val;
5972 while (*e && *e != '\t') e++;
5974 if (*e == '\t') e++;
5979 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5980 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5981 ssh2_pkt_addstring(ssh, "env");
5982 ssh2_pkt_addbool(ssh, 1); /* want reply */
5983 ssh2_pkt_addstring_start(ssh);
5984 ssh2_pkt_addstring_data(ssh, var, varend-var);
5985 ssh2_pkt_addstring(ssh, val);
5991 logeventf(ssh, "Sent %d environment variables", s->num_env);
5994 s->env_left = s->num_env;
5996 while (s->env_left > 0) {
5998 crWaitUntilV(ispkt);
5999 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6000 unsigned i = ssh_pkt_getuint32(ssh);
6001 struct ssh_channel *c;
6002 c = find234(ssh->channels, &i, ssh_channelfind);
6004 continue; /* nonexistent channel */
6005 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6007 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6009 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6010 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6011 bombout(("Unexpected response to environment request:"
6012 " packet type %d", ssh->pktin.type));
6022 if (s->env_ok == s->num_env) {
6023 logevent("All environment variables successfully set");
6024 } else if (s->env_ok == 0) {
6025 logevent("All environment variables refused");
6026 c_write_str(ssh, "Server refused to set environment variables\r\n");
6028 logeventf(ssh, "%d environment variables refused",
6029 s->num_env - s->env_ok);
6030 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6035 * Start a shell or a remote command. We may have to attempt
6036 * this twice if the config data has provided a second choice
6039 if (ssh->mainchan) while (1) {
6043 if (ssh->fallback_cmd) {
6044 subsys = ssh->cfg.ssh_subsys2;
6045 cmd = ssh->cfg.remote_cmd_ptr2;
6047 subsys = ssh->cfg.ssh_subsys;
6048 cmd = ssh->cfg.remote_cmd_ptr;
6051 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6052 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
6054 ssh2_pkt_addstring(ssh, "subsystem");
6055 ssh2_pkt_addbool(ssh, 1); /* want reply */
6056 ssh2_pkt_addstring(ssh, cmd);
6058 ssh2_pkt_addstring(ssh, "exec");
6059 ssh2_pkt_addbool(ssh, 1); /* want reply */
6060 ssh2_pkt_addstring(ssh, cmd);
6062 ssh2_pkt_addstring(ssh, "shell");
6063 ssh2_pkt_addbool(ssh, 1); /* want reply */
6067 crWaitUntilV(ispkt);
6068 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6069 unsigned i = ssh_pkt_getuint32(ssh);
6070 struct ssh_channel *c;
6071 c = find234(ssh->channels, &i, ssh_channelfind);
6073 continue; /* nonexistent channel */
6074 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6076 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6077 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6078 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6079 bombout(("Unexpected response to shell/command request:"
6080 " packet type %d", ssh->pktin.type));
6084 * We failed to start the command. If this is the
6085 * fallback command, we really are finished; if it's
6086 * not, and if the fallback command exists, try falling
6087 * back to it before complaining.
6089 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6090 logevent("Primary command failed; attempting fallback");
6091 ssh->fallback_cmd = TRUE;
6094 bombout(("Server refused to start a shell/command"));
6097 logevent("Started a shell/command");
6102 ssh->state = SSH_STATE_SESSION;
6103 if (ssh->size_needed)
6104 ssh_size(ssh, ssh->term_width, ssh->term_height);
6105 if (ssh->eof_needed)
6106 ssh_special(ssh, TS_EOF);
6112 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6117 s->try_send = FALSE;
6119 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
6120 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
6123 unsigned i = ssh_pkt_getuint32(ssh);
6124 struct ssh_channel *c;
6125 c = find234(ssh->channels, &i, ssh_channelfind);
6127 continue; /* nonexistent channel */
6128 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6129 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
6130 continue; /* extended but not stderr */
6131 ssh_pkt_getstring(ssh, &data, &length);
6134 c->v.v2.locwindow -= length;
6136 case CHAN_MAINSESSION:
6138 from_backend(ssh->frontend, ssh->pktin.type ==
6139 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6143 bufsize = x11_send(c->u.x11.s, data, length);
6146 bufsize = pfd_send(c->u.pfd.s, data, length);
6149 while (length > 0) {
6150 if (c->u.a.lensofar < 4) {
6151 int l = min(4 - c->u.a.lensofar, length);
6152 memcpy(c->u.a.msglen + c->u.a.lensofar,
6156 c->u.a.lensofar += l;
6158 if (c->u.a.lensofar == 4) {
6160 4 + GET_32BIT(c->u.a.msglen);
6161 c->u.a.message = snewn(c->u.a.totallen,
6163 memcpy(c->u.a.message, c->u.a.msglen, 4);
6165 if (c->u.a.lensofar >= 4 && length > 0) {
6167 min(c->u.a.totallen - c->u.a.lensofar,
6169 memcpy(c->u.a.message + c->u.a.lensofar,
6173 c->u.a.lensofar += l;
6175 if (c->u.a.lensofar == c->u.a.totallen) {
6178 if (agent_query(c->u.a.message,
6181 ssh_agentf_callback, c))
6182 ssh_agentf_callback(c, reply, replylen);
6183 sfree(c->u.a.message);
6184 c->u.a.lensofar = 0;
6191 * If we are not buffering too much data,
6192 * enlarge the window again at the remote side.
6194 if (bufsize < OUR_V2_WINSIZE)
6195 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6197 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
6198 unsigned i = ssh_pkt_getuint32(ssh);
6199 struct ssh_channel *c;
6201 c = find234(ssh->channels, &i, ssh_channelfind);
6203 continue; /* nonexistent channel */
6205 if (c->type == CHAN_X11) {
6207 * Remote EOF on an X11 channel means we should
6208 * wrap up and close the channel ourselves.
6210 x11_close(c->u.x11.s);
6212 } else if (c->type == CHAN_AGENT) {
6214 } else if (c->type == CHAN_SOCKDATA) {
6215 pfd_close(c->u.pfd.s);
6218 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
6219 unsigned i = ssh_pkt_getuint32(ssh);
6220 struct ssh_channel *c;
6222 c = find234(ssh->channels, &i, ssh_channelfind);
6223 if (!c || ((int)c->remoteid) == -1) {
6224 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6225 c ? "half-open" : "nonexistent", i));
6228 /* Do pre-close processing on the channel. */
6230 case CHAN_MAINSESSION:
6231 ssh->mainchan = NULL;
6232 update_specials_menu(ssh->frontend);
6235 if (c->u.x11.s != NULL)
6236 x11_close(c->u.x11.s);
6243 if (c->u.pfd.s != NULL)
6244 pfd_close(c->u.pfd.s);
6248 if (c->closes == 0) {
6249 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6250 ssh2_pkt_adduint32(ssh, c->remoteid);
6253 del234(ssh->channels, c);
6254 bufchain_clear(&c->v.v2.outbuffer);
6258 * See if that was the last channel left open.
6259 * (This is only our termination condition if we're
6260 * not running in -N mode.)
6262 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6263 logevent("All channels closed. Disconnecting");
6266 * We used to send SSH_MSG_DISCONNECT here,
6267 * because I'd believed that _every_ conforming
6268 * SSH2 connection had to end with a disconnect
6269 * being sent by at least one side; apparently
6270 * I was wrong and it's perfectly OK to
6271 * unceremoniously slam the connection shut
6272 * when you're done, and indeed OpenSSH feels
6273 * this is more polite than sending a
6274 * DISCONNECT. So now we don't.
6276 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6277 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6278 ssh2_pkt_addstring(ssh, "All open channels closed");
6279 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6282 ssh_closing((Plug)ssh, NULL, 0, 0);
6285 continue; /* remote sends close; ignore (FIXME) */
6286 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6287 unsigned i = ssh_pkt_getuint32(ssh);
6288 struct ssh_channel *c;
6289 c = find234(ssh->channels, &i, ssh_channelfind);
6290 if (!c || c->closes)
6291 continue; /* nonexistent or closing channel */
6292 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6294 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6295 unsigned i = ssh_pkt_getuint32(ssh);
6296 struct ssh_channel *c;
6297 c = find234(ssh->channels, &i, ssh_channelfind);
6299 continue; /* nonexistent channel */
6300 if (c->type != CHAN_SOCKDATA_DORMANT)
6301 continue; /* dunno why they're confirming this */
6302 c->remoteid = ssh_pkt_getuint32(ssh);
6303 c->type = CHAN_SOCKDATA;
6304 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6305 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
6307 pfd_confirm(c->u.pfd.s);
6310 * We have a pending close on this channel,
6311 * which we decided on before the server acked
6312 * the channel open. So now we know the
6313 * remoteid, we can close it again.
6315 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6316 ssh2_pkt_adduint32(ssh, c->remoteid);
6319 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
6320 static const char *const reasons[] = {
6321 "<unknown reason code>",
6322 "Administratively prohibited",
6324 "Unknown channel type",
6325 "Resource shortage",
6327 unsigned i = ssh_pkt_getuint32(ssh);
6328 unsigned reason_code;
6329 char *reason_string;
6332 struct ssh_channel *c;
6333 c = find234(ssh->channels, &i, ssh_channelfind);
6335 continue; /* nonexistent channel */
6336 if (c->type != CHAN_SOCKDATA_DORMANT)
6337 continue; /* dunno why they're failing this */
6339 reason_code = ssh_pkt_getuint32(ssh);
6340 if (reason_code >= lenof(reasons))
6341 reason_code = 0; /* ensure reasons[reason_code] in range */
6342 ssh_pkt_getstring(ssh, &reason_string, &reason_length);
6343 message = dupprintf("Forwarded connection refused by"
6344 " server: %s [%.*s]", reasons[reason_code],
6345 reason_length, reason_string);
6349 pfd_close(c->u.pfd.s);
6351 del234(ssh->channels, c);
6353 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
6356 int typelen, want_reply;
6357 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6358 struct ssh_channel *c;
6360 localid = ssh_pkt_getuint32(ssh);
6361 ssh_pkt_getstring(ssh, &type, &typelen);
6362 want_reply = ssh2_pkt_getbool(ssh);
6365 * First, check that the channel exists. Otherwise,
6366 * we can instantly disconnect with a rude message.
6368 c = find234(ssh->channels, &localid, ssh_channelfind);
6371 sprintf(buf, "Received channel request for nonexistent"
6372 " channel %d", localid);
6374 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6375 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6376 ssh2_pkt_addstring(ssh, buf);
6377 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6379 connection_fatal(ssh->frontend, "%s", buf);
6380 ssh_closing((Plug)ssh, NULL, 0, 0);
6385 * Having got the channel number, we now look at
6386 * the request type string to see if it's something
6389 if (c == ssh->mainchan) {
6391 * We recognise "exit-status" and "exit-signal" on
6392 * the primary channel.
6394 if (typelen == 11 &&
6395 !memcmp(type, "exit-status", 11)) {
6397 ssh->exitcode = ssh_pkt_getuint32(ssh);
6398 logeventf(ssh, "Server sent command exit status %d",
6400 reply = SSH2_MSG_CHANNEL_SUCCESS;
6402 } else if (typelen == 11 &&
6403 !memcmp(type, "exit-signal", 11)) {
6405 int is_plausible = TRUE, is_int = FALSE;
6406 char *fmt_sig = "", *fmt_msg = "";
6408 int msglen = 0, core = FALSE;
6409 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6410 * provide an `int' for the signal, despite its
6411 * having been a `string' in the drafts since at
6412 * least 2001. (Fixed in session.c 1.147.) Try to
6413 * infer which we can safely parse it as. */
6415 unsigned char *p = ssh->pktin.body +
6416 ssh->pktin.savedpos;
6417 long len = ssh->pktin.length - ssh->pktin.savedpos;
6418 unsigned long num = GET_32BIT(p); /* what is it? */
6419 /* If it's 0, it hardly matters; assume string */
6423 int maybe_int = FALSE, maybe_str = FALSE;
6424 #define CHECK_HYPOTHESIS(offset, result) \
6427 if (q >= 0 && q+4 <= len) { \
6428 q = q + 4 + GET_32BIT(p+q); \
6429 if (q >= 0 && q+4 <= len && \
6430 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
6434 CHECK_HYPOTHESIS(4+1, maybe_int);
6435 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6436 #undef CHECK_HYPOTHESIS
6437 if (maybe_int && !maybe_str)
6439 else if (!maybe_int && maybe_str)
6442 /* Crikey. Either or neither. Panic. */
6443 is_plausible = FALSE;
6448 /* Old non-standard OpenSSH. */
6449 int signum = ssh_pkt_getuint32(ssh);
6450 fmt_sig = dupprintf(" %d", signum);
6452 /* As per the drafts. */
6455 ssh_pkt_getstring(ssh, &sig, &siglen);
6456 /* Signal name isn't supposed to be blank, but
6457 * let's cope gracefully if it is. */
6459 fmt_sig = dupprintf(" \"%.*s\"",
6463 core = ssh2_pkt_getbool(ssh);
6464 ssh_pkt_getstring(ssh, &msg, &msglen);
6466 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6468 /* ignore lang tag */
6469 } /* else don't attempt to parse */
6470 logeventf(ssh, "Server exited on signal%s%s%s",
6471 fmt_sig, core ? " (core dumped)" : "",
6473 if (*fmt_sig) sfree(fmt_sig);
6474 if (*fmt_msg) sfree(fmt_msg);
6475 reply = SSH2_MSG_CHANNEL_SUCCESS;
6480 * This is a channel request we don't know
6481 * about, so we now either ignore the request
6482 * or respond with CHANNEL_FAILURE, depending
6485 reply = SSH2_MSG_CHANNEL_FAILURE;
6488 ssh2_pkt_init(ssh, reply);
6489 ssh2_pkt_adduint32(ssh, c->remoteid);
6492 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
6494 int typelen, want_reply;
6496 ssh_pkt_getstring(ssh, &type, &typelen);
6497 want_reply = ssh2_pkt_getbool(ssh);
6500 * We currently don't support any global requests
6501 * at all, so we either ignore the request or
6502 * respond with REQUEST_FAILURE, depending on
6506 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6509 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6516 struct ssh_channel *c;
6517 unsigned remid, winsize, pktsize;
6518 ssh_pkt_getstring(ssh, &type, &typelen);
6519 c = snew(struct ssh_channel);
6522 remid = ssh_pkt_getuint32(ssh);
6523 winsize = ssh_pkt_getuint32(ssh);
6524 pktsize = ssh_pkt_getuint32(ssh);
6526 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6529 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6530 addrstr = snewn(peeraddrlen+1, char);
6531 memcpy(addrstr, peeraddr, peeraddrlen);
6532 addrstr[peeraddrlen] = '\0';
6533 peerport = ssh_pkt_getuint32(ssh);
6535 logeventf(ssh, "Received X11 connect request from %s:%d",
6538 if (!ssh->X11_fwd_enabled)
6539 error = "X11 forwarding is not enabled";
6540 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6541 ssh->x11auth, addrstr, peerport,
6542 &ssh->cfg) != NULL) {
6543 error = "Unable to open an X11 connection";
6545 logevent("Opening X11 forward connection succeeded");
6550 } else if (typelen == 15 &&
6551 !memcmp(type, "forwarded-tcpip", 15)) {
6552 struct ssh_rportfwd pf, *realpf;
6555 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6556 pf.sport = ssh_pkt_getuint32(ssh);
6557 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6558 peerport = ssh_pkt_getuint32(ssh);
6559 realpf = find234(ssh->rportfwds, &pf, NULL);
6560 logeventf(ssh, "Received remote port %d open request "
6561 "from %s:%d", pf.sport, peeraddr, peerport);
6562 if (realpf == NULL) {
6563 error = "Remote port is not recognised";
6565 const char *e = pfd_newconnect(&c->u.pfd.s,
6569 logeventf(ssh, "Attempting to forward remote port to "
6570 "%s:%d", realpf->dhost, realpf->dport);
6572 logeventf(ssh, "Port open failed: %s", e);
6573 error = "Port open failed";
6575 logevent("Forwarded port opened successfully");
6576 c->type = CHAN_SOCKDATA;
6579 } else if (typelen == 22 &&
6580 !memcmp(type, "auth-agent@openssh.com", 3)) {
6581 if (!ssh->agentfwd_enabled)
6582 error = "Agent forwarding is not enabled";
6584 c->type = CHAN_AGENT; /* identify channel type */
6585 c->u.a.lensofar = 0;
6588 error = "Unsupported channel type requested";
6591 c->remoteid = remid;
6593 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6594 ssh2_pkt_adduint32(ssh, c->remoteid);
6595 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6596 ssh2_pkt_addstring(ssh, error);
6597 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6599 logeventf(ssh, "Rejected channel open: %s", error);
6602 c->localid = alloc_channel_id(ssh);
6604 c->v.v2.locwindow = OUR_V2_WINSIZE;
6605 c->v.v2.remwindow = winsize;
6606 c->v.v2.remmaxpkt = pktsize;
6607 bufchain_init(&c->v.v2.outbuffer);
6608 add234(ssh->channels, c);
6609 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6610 ssh2_pkt_adduint32(ssh, c->remoteid);
6611 ssh2_pkt_adduint32(ssh, c->localid);
6612 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6613 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6617 bombout(("Strange packet received: type %d", ssh->pktin.type));
6620 } else if (ssh->mainchan) {
6622 * We have spare data. Add it to the channel buffer.
6624 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6629 struct ssh_channel *c;
6631 * Try to send data on all channels if we can.
6633 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6636 continue; /* don't send on closing channels */
6637 bufsize = ssh2_try_send(c);
6640 case CHAN_MAINSESSION:
6641 /* stdin need not receive an unthrottle
6642 * notification since it will be polled */
6645 x11_unthrottle(c->u.x11.s);
6648 /* agent sockets are request/response and need no
6649 * buffer management */
6652 pfd_unthrottle(c->u.pfd.s);
6664 * Handle the top-level SSH2 protocol.
6666 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6668 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6670 do_ssh2_authconn(ssh, in, inlen, ispkt);
6674 * Called to set up the connection.
6676 * Returns an error message, or NULL on success.
6678 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6680 char *host, int port, char **realhost, int nodelay,
6686 ssh = snew(struct ssh_tag);
6687 ssh->cfg = *cfg; /* STRUCTURE COPY */
6688 ssh->version = 0; /* when not ready yet */
6691 ssh->v1_cipher_ctx = NULL;
6692 ssh->crcda_ctx = NULL;
6693 ssh->cscipher = NULL;
6694 ssh->cs_cipher_ctx = NULL;
6695 ssh->sccipher = NULL;
6696 ssh->sc_cipher_ctx = NULL;
6698 ssh->cs_mac_ctx = NULL;
6700 ssh->sc_mac_ctx = NULL;
6702 ssh->cs_comp_ctx = NULL;
6704 ssh->sc_comp_ctx = NULL;
6706 ssh->kex_ctx = NULL;
6707 ssh->hostkey = NULL;
6709 ssh->state = SSH_STATE_PREPACKET;
6710 ssh->size_needed = FALSE;
6711 ssh->eof_needed = FALSE;
6715 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6716 ssh->pktin = ssh->pktout = empty;
6718 ssh->deferred_send_data = NULL;
6719 ssh->deferred_len = 0;
6720 ssh->deferred_size = 0;
6721 ssh->pktout_logmode = PKTLOG_EMIT;
6722 ssh->pktout_nblanks = 0;
6723 ssh->pktout_blanks = NULL;
6724 ssh->fallback_cmd = 0;
6726 ssh->x11auth = NULL;
6727 ssh->v1_compressing = FALSE;
6728 ssh->v2_outgoing_sequence = 0;
6729 ssh->ssh1_rdpkt_crstate = 0;
6730 ssh->ssh2_rdpkt_crstate = 0;
6731 ssh->do_ssh_init_crstate = 0;
6732 ssh->ssh_gotdata_crstate = 0;
6733 ssh->ssh1_protocol_crstate = 0;
6734 ssh->do_ssh1_login_crstate = 0;
6735 ssh->do_ssh2_transport_crstate = 0;
6736 ssh->do_ssh2_authconn_crstate = 0;
6737 ssh->do_ssh_init_state = NULL;
6738 ssh->do_ssh1_login_state = NULL;
6739 ssh->do_ssh2_transport_state = NULL;
6740 ssh->do_ssh2_authconn_state = NULL;
6741 ssh->mainchan = NULL;
6742 ssh->throttled_all = 0;
6743 ssh->v1_stdout_throttling = 0;
6745 *backend_handle = ssh;
6748 if (crypto_startup() == 0)
6749 return "Microsoft high encryption pack not installed!";
6752 ssh->frontend = frontend_handle;
6753 ssh->term_width = ssh->cfg.width;
6754 ssh->term_height = ssh->cfg.height;
6756 ssh->channels = NULL;
6757 ssh->rportfwds = NULL;
6762 ssh->v1_throttle_count = 0;
6763 ssh->overall_bufsize = 0;
6764 ssh->fallback_cmd = 0;
6766 ssh->protocol = NULL;
6768 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
6775 static void ssh_free(void *handle)
6777 Ssh ssh = (Ssh) handle;
6778 struct ssh_channel *c;
6779 struct ssh_rportfwd *pf;
6781 if (ssh->v1_cipher_ctx)
6782 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6783 if (ssh->cs_cipher_ctx)
6784 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6785 if (ssh->sc_cipher_ctx)
6786 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6787 if (ssh->cs_mac_ctx)
6788 ssh->csmac->free_context(ssh->cs_mac_ctx);
6789 if (ssh->sc_mac_ctx)
6790 ssh->scmac->free_context(ssh->sc_mac_ctx);
6791 if (ssh->cs_comp_ctx) {
6793 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6795 zlib_compress_cleanup(ssh->cs_comp_ctx);
6797 if (ssh->sc_comp_ctx) {
6799 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6801 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6804 dh_cleanup(ssh->kex_ctx);
6805 sfree(ssh->savedhost);
6807 if (ssh->channels) {
6808 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6811 if (c->u.x11.s != NULL)
6812 x11_close(c->u.x11.s);
6815 if (c->u.pfd.s != NULL)
6816 pfd_close(c->u.pfd.s);
6821 freetree234(ssh->channels);
6824 if (ssh->rportfwds) {
6825 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6827 freetree234(ssh->rportfwds);
6829 sfree(ssh->deferred_send_data);
6831 x11_free_auth(ssh->x11auth);
6832 sfree(ssh->do_ssh_init_state);
6833 sfree(ssh->do_ssh1_login_state);
6834 sfree(ssh->do_ssh2_transport_state);
6835 sfree(ssh->do_ssh2_authconn_state);
6836 if (ssh->pktout.data) {
6837 sfree(ssh->pktout.data);
6838 ssh->pktout.data = NULL;
6840 if (ssh->pktin.data) {
6841 sfree(ssh->pktin.data);
6842 ssh->pktin.data = NULL;
6844 if (ssh->crcda_ctx) {
6845 crcda_free_context(ssh->crcda_ctx);
6846 ssh->crcda_ctx = NULL;
6854 * Reconfigure the SSH backend.
6856 * Currently, this function does nothing very useful. In future,
6857 * however, we could do some handy things with it. For example, we
6858 * could make the port forwarding configurer active in the Change
6859 * Settings box, and this routine could close down existing
6860 * forwardings and open up new ones in response to changes.
6862 static void ssh_reconfig(void *handle, Config *cfg)
6864 Ssh ssh = (Ssh) handle;
6865 ssh->cfg = *cfg; /* STRUCTURE COPY */
6869 * Called to send data down the Telnet connection.
6871 static int ssh_send(void *handle, char *buf, int len)
6873 Ssh ssh = (Ssh) handle;
6875 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6878 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6880 return ssh_sendbuffer(ssh);
6884 * Called to query the current amount of buffered stdin data.
6886 static int ssh_sendbuffer(void *handle)
6888 Ssh ssh = (Ssh) handle;
6891 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6895 * If the SSH socket itself has backed up, add the total backup
6896 * size on that to any individual buffer on the stdin channel.
6899 if (ssh->throttled_all)
6900 override_value = ssh->overall_bufsize;
6902 if (ssh->version == 1) {
6903 return override_value;
6904 } else if (ssh->version == 2) {
6905 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6906 return override_value;
6908 return (override_value +
6909 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6916 * Called to set the size of the window from SSH's POV.
6918 static void ssh_size(void *handle, int width, int height)
6920 Ssh ssh = (Ssh) handle;
6922 ssh->term_width = width;
6923 ssh->term_height = height;
6925 switch (ssh->state) {
6926 case SSH_STATE_BEFORE_SIZE:
6927 case SSH_STATE_PREPACKET:
6928 case SSH_STATE_CLOSED:
6929 break; /* do nothing */
6930 case SSH_STATE_INTERMED:
6931 ssh->size_needed = TRUE; /* buffer for later */
6933 case SSH_STATE_SESSION:
6934 if (!ssh->cfg.nopty) {
6935 if (ssh->version == 1) {
6936 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6937 PKT_INT, ssh->term_height,
6938 PKT_INT, ssh->term_width,
6939 PKT_INT, 0, PKT_INT, 0, PKT_END);
6940 } else if (ssh->mainchan) {
6941 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6942 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6943 ssh2_pkt_addstring(ssh, "window-change");
6944 ssh2_pkt_addbool(ssh, 0);
6945 ssh2_pkt_adduint32(ssh, ssh->term_width);
6946 ssh2_pkt_adduint32(ssh, ssh->term_height);
6947 ssh2_pkt_adduint32(ssh, 0);
6948 ssh2_pkt_adduint32(ssh, 0);
6957 * Return a list of the special codes that make sense in this
6960 static const struct telnet_special *ssh_get_specials(void *handle)
6962 static const struct telnet_special ignore_special[] = {
6963 {"IGNORE message", TS_NOP},
6965 static const struct telnet_special ssh2_session_specials[] = {
6968 /* These are the signal names defined by draft-ietf-secsh-connect-19.
6969 * They include all the ISO C signals, but are a subset of the POSIX
6970 * required signals. */
6971 {"SIGINT (Interrupt)", TS_SIGINT},
6972 {"SIGTERM (Terminate)", TS_SIGTERM},
6973 {"SIGKILL (Kill)", TS_SIGKILL},
6974 {"SIGQUIT (Quit)", TS_SIGQUIT},
6975 {"SIGHUP (Hangup)", TS_SIGHUP},
6976 {"More signals", TS_SUBMENU},
6977 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
6978 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
6979 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
6980 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
6983 static const struct telnet_special specials_end[] = {
6986 static struct telnet_special ssh_specials[lenof(ignore_special) +
6987 lenof(ssh2_session_specials) +
6988 lenof(specials_end)];
6989 Ssh ssh = (Ssh) handle;
6991 #define ADD_SPECIALS(name) \
6993 assert((i + lenof(name)) <= lenof(ssh_specials)); \
6994 memcpy(&ssh_specials[i], name, sizeof name); \
6998 if (ssh->version == 1) {
6999 /* Don't bother offering IGNORE if we've decided the remote
7000 * won't cope with it, since we wouldn't bother sending it if
7002 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7003 ADD_SPECIALS(ignore_special);
7004 } else if (ssh->version == 2) {
7005 /* XXX add rekey, when implemented */
7006 ADD_SPECIALS(ignore_special);
7008 ADD_SPECIALS(ssh2_session_specials);
7009 } /* else we're not ready yet */
7012 ADD_SPECIALS(specials_end);
7013 return ssh_specials;
7021 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7022 * can send an EOF and collect resulting output (e.g. `plink
7025 static void ssh_special(void *handle, Telnet_Special code)
7027 Ssh ssh = (Ssh) handle;
7029 if (code == TS_EOF) {
7030 if (ssh->state != SSH_STATE_SESSION) {
7032 * Buffer the EOF in case we are pre-SESSION, so we can
7033 * send it as soon as we reach SESSION.
7036 ssh->eof_needed = TRUE;
7039 if (ssh->version == 1) {
7040 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7041 } else if (ssh->mainchan) {
7042 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
7043 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7046 logevent("Sent EOF message");
7047 } else if (code == TS_PING || code == TS_NOP) {
7048 if (ssh->state == SSH_STATE_CLOSED
7049 || ssh->state == SSH_STATE_PREPACKET) return;
7050 if (ssh->version == 1) {
7051 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7052 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7054 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
7055 ssh2_pkt_addstring_start(ssh);
7058 } else if (code == TS_BRK) {
7059 if (ssh->state == SSH_STATE_CLOSED
7060 || ssh->state == SSH_STATE_PREPACKET) return;
7061 if (ssh->version == 1) {
7062 logevent("Unable to send BREAK signal in SSH1");
7063 } else if (ssh->mainchan) {
7064 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
7065 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7066 ssh2_pkt_addstring(ssh, "break");
7067 ssh2_pkt_addbool(ssh, 0);
7068 ssh2_pkt_adduint32(ssh, 0); /* default break length */
7072 /* Is is a POSIX signal? */
7073 char *signame = NULL;
7074 if (code == TS_SIGABRT) signame = "ABRT";
7075 if (code == TS_SIGALRM) signame = "ALRM";
7076 if (code == TS_SIGFPE) signame = "FPE";
7077 if (code == TS_SIGHUP) signame = "HUP";
7078 if (code == TS_SIGILL) signame = "ILL";
7079 if (code == TS_SIGINT) signame = "INT";
7080 if (code == TS_SIGKILL) signame = "KILL";
7081 if (code == TS_SIGPIPE) signame = "PIPE";
7082 if (code == TS_SIGQUIT) signame = "QUIT";
7083 if (code == TS_SIGSEGV) signame = "SEGV";
7084 if (code == TS_SIGTERM) signame = "TERM";
7085 if (code == TS_SIGUSR1) signame = "USR1";
7086 if (code == TS_SIGUSR2) signame = "USR2";
7087 /* The SSH-2 protocol does in principle support arbitrary named
7088 * signals, including signame@domain, but we don't support those. */
7090 /* It's a signal. */
7091 if (ssh->version == 2 && ssh->mainchan) {
7092 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
7093 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7094 ssh2_pkt_addstring(ssh, "signal");
7095 ssh2_pkt_addbool(ssh, 0);
7096 ssh2_pkt_addstring(ssh, signame);
7098 logeventf(ssh, "Sent signal SIG%s", signame);
7101 /* Never heard of it. Do nothing */
7106 void *new_sock_channel(void *handle, Socket s)
7108 Ssh ssh = (Ssh) handle;
7109 struct ssh_channel *c;
7110 c = snew(struct ssh_channel);
7114 c->remoteid = -1; /* to be set when open confirmed */
7115 c->localid = alloc_channel_id(ssh);
7117 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7119 bufchain_init(&c->v.v2.outbuffer);
7120 add234(ssh->channels, c);
7126 * This is called when stdout/stderr (the entity to which
7127 * from_backend sends data) manages to clear some backlog.
7129 static void ssh_unthrottle(void *handle, int bufsize)
7131 Ssh ssh = (Ssh) handle;
7132 if (ssh->version == 1) {
7133 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7134 ssh->v1_stdout_throttling = 0;
7135 ssh1_throttle(ssh, -1);
7138 if (ssh->mainchan && ssh->mainchan->closes == 0)
7139 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7143 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7145 struct ssh_channel *c = (struct ssh_channel *)channel;
7148 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7150 if (ssh->version == 1) {
7151 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7152 PKT_INT, c->localid,
7155 //PKT_STR, <org:orgport>,
7158 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
7159 ssh2_pkt_addstring(ssh, "direct-tcpip");
7160 ssh2_pkt_adduint32(ssh, c->localid);
7161 c->v.v2.locwindow = OUR_V2_WINSIZE;
7162 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
7163 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
7164 ssh2_pkt_addstring(ssh, hostname);
7165 ssh2_pkt_adduint32(ssh, port);
7167 * We make up values for the originator data; partly it's
7168 * too much hassle to keep track, and partly I'm not
7169 * convinced the server should be told details like that
7170 * about my local network configuration.
7172 ssh2_pkt_addstring(ssh, "client-side-connection");
7173 ssh2_pkt_adduint32(ssh, 0);
7179 static Socket ssh_socket(void *handle)
7181 Ssh ssh = (Ssh) handle;
7185 static int ssh_sendok(void *handle)
7187 Ssh ssh = (Ssh) handle;
7188 return ssh->send_ok;
7191 static int ssh_ldisc(void *handle, int option)
7193 Ssh ssh = (Ssh) handle;
7194 if (option == LD_ECHO)
7195 return ssh->echoing;
7196 if (option == LD_EDIT)
7197 return ssh->editing;
7201 static void ssh_provide_ldisc(void *handle, void *ldisc)
7203 Ssh ssh = (Ssh) handle;
7207 static void ssh_provide_logctx(void *handle, void *logctx)
7209 Ssh ssh = (Ssh) handle;
7210 ssh->logctx = logctx;
7213 static int ssh_return_exitcode(void *handle)
7215 Ssh ssh = (Ssh) handle;
7219 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7223 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7224 * that fails. This variable is the means by which scp.c can reach
7225 * into the SSH code and find out which one it got.
7227 extern int ssh_fallback_cmd(void *handle)
7229 Ssh ssh = (Ssh) handle;
7230 return ssh->fallback_cmd;
7233 Backend ssh_backend = {
7243 ssh_return_exitcode,