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 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
279 * which explains the theory behind these macros.
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
286 * - right-click ssh.c in the FileView
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
292 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
295 if (!ssh->t) ssh->t = snew(struct t); \
297 #define crFinish(z) } *crLine = 0; return (z); }
298 #define crFinishV } *crLine = 0; return; }
299 #define crReturn(z) \
301 *crLine =__LINE__; return (z); case __LINE__:;\
305 *crLine=__LINE__; return; case __LINE__:;\
307 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
308 #define crStopV do{ *crLine = 0; return; }while(0)
309 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
310 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
312 typedef struct ssh_tag *Ssh;
314 static void ssh2_pkt_init(Ssh, int pkt_type);
315 static void ssh2_pkt_addbool(Ssh, unsigned char value);
316 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317 static void ssh2_pkt_addstring_start(Ssh);
318 static void ssh2_pkt_addstring_str(Ssh, char *data);
319 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320 static void ssh2_pkt_addstring(Ssh, char *data);
321 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
322 static void ssh2_pkt_addmp(Ssh, Bignum b);
323 static int ssh2_pkt_construct(Ssh);
324 static void ssh2_pkt_send(Ssh);
325 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
326 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
329 * Buffer management constants. There are several of these for
330 * various different purposes:
332 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
333 * on a local data stream before we throttle the whole SSH
334 * connection (in SSH1 only). Throttling the whole connection is
335 * pretty drastic so we set this high in the hope it won't
338 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
339 * on the SSH connection itself before we defensively throttle
340 * _all_ local data streams. This is pretty drastic too (though
341 * thankfully unlikely in SSH2 since the window mechanism should
342 * ensure that the server never has any need to throttle its end
343 * of the connection), so we set this high as well.
345 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
349 #define SSH1_BUFFER_LIMIT 32768
350 #define SSH_MAX_BACKLOG 32768
351 #define OUR_V2_WINSIZE 16384
353 const static struct ssh_kex *kex_algs[] = {
354 &ssh_diffiehellman_gex,
358 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
360 static void *nullmac_make_context(void)
364 static void nullmac_free_context(void *handle)
367 static void nullmac_key(void *handle, unsigned char *key)
370 static void nullmac_generate(void *handle, unsigned char *blk, int len,
374 static int nullmac_verify(void *handle, unsigned char *blk, int len,
379 const static struct ssh_mac ssh_mac_none = {
380 nullmac_make_context, nullmac_free_context, nullmac_key,
381 nullmac_generate, nullmac_verify, "none", 0
383 const static struct ssh_mac *macs[] = {
384 &ssh_sha1, &ssh_md5, &ssh_mac_none
386 const static struct ssh_mac *buggymacs[] = {
387 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
390 static void *ssh_comp_none_init(void)
394 static void ssh_comp_none_cleanup(void *handle)
397 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
398 unsigned char **outblock, int *outlen)
402 static int ssh_comp_none_disable(void *handle)
406 const static struct ssh_compress ssh_comp_none = {
408 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
409 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
410 ssh_comp_none_disable, NULL
412 extern const struct ssh_compress ssh_zlib;
413 const static struct ssh_compress *compressions[] = {
414 &ssh_zlib, &ssh_comp_none
417 enum { /* channel types */
422 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
426 * 2-3-4 tree storing channels.
429 Ssh ssh; /* pointer back to main context */
430 unsigned remoteid, localid;
433 * In SSH1, this value contains four bits:
435 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
436 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
438 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
440 * A channel is completely finished with when all four bits are set.
444 struct ssh1_data_channel {
447 struct ssh2_data_channel {
449 unsigned remwindow, remmaxpkt;
454 struct ssh_agent_channel {
455 unsigned char *message;
456 unsigned char msglen[4];
457 int lensofar, totallen;
459 struct ssh_x11_channel {
462 struct ssh_pfd_channel {
469 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
470 * 2 use this structure in different ways, reflecting SSH 2's
471 * altogether saner approach to port forwarding.
473 * In SSH 1, you arrange a remote forwarding by sending the server
474 * the remote port number, and the local destination host:port.
475 * When a connection comes in, the server sends you back that
476 * host:port pair, and you connect to it. This is a ready-made
477 * security hole if you're not on the ball: a malicious server
478 * could send you back _any_ host:port pair, so if you trustingly
479 * connect to the address it gives you then you've just opened the
480 * entire inside of your corporate network just by connecting
481 * through it to a dodgy SSH server. Hence, we must store a list of
482 * host:port pairs we _are_ trying to forward to, and reject a
483 * connection request from the server if it's not in the list.
485 * In SSH 2, each side of the connection minds its own business and
486 * doesn't send unnecessary information to the other. You arrange a
487 * remote forwarding by sending the server just the remote port
488 * number. When a connection comes in, the server tells you which
489 * of its ports was connected to; and _you_ have to remember what
490 * local host:port pair went with that port number.
492 * Hence: in SSH 1 this structure stores host:port pairs we intend
493 * to allow connections to, and is indexed by those host:port
494 * pairs. In SSH 2 it stores a mapping from source port to
495 * destination host:port pair, and is indexed by source port.
497 struct ssh_rportfwd {
498 unsigned sport, dport;
511 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
512 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
513 static void ssh_size(void *handle, int width, int height);
514 static void ssh_special(void *handle, Telnet_Special);
515 static int ssh2_try_send(struct ssh_channel *c);
516 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
517 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
518 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
519 static int ssh_sendbuffer(void *handle);
520 static void ssh_do_close(Ssh ssh);
522 struct rdpkt1_state_tag {
523 long len, pad, biglen, to_read;
524 unsigned long realcrc, gotcrc;
530 struct rdpkt2_state_tag {
531 long len, pad, payload, packetlen, maclen;
534 unsigned long incoming_sequence;
538 const struct plug_function_table *fn;
539 /* the above field _must_ be first in the structure */
541 SHA_State exhash, exhashbase;
548 unsigned char session_key[32];
550 int v1_remote_protoflags;
551 int v1_local_protoflags;
552 int agentfwd_enabled;
555 const struct ssh_cipher *cipher;
558 const struct ssh2_cipher *cscipher, *sccipher;
559 void *cs_cipher_ctx, *sc_cipher_ctx;
560 const struct ssh_mac *csmac, *scmac;
561 void *cs_mac_ctx, *sc_mac_ctx;
562 const struct ssh_compress *cscomp, *sccomp;
563 void *cs_comp_ctx, *sc_comp_ctx;
564 const struct ssh_kex *kex;
565 const struct ssh_signkey *hostkey;
566 unsigned char v2_session_id[20];
572 int echoing, editing;
576 int ospeed, ispeed; /* temporaries */
577 int term_width, term_height;
579 tree234 *channels; /* indexed by local id */
580 struct ssh_channel *mainchan; /* primary session channel */
587 SSH_STATE_BEFORE_SIZE,
593 int size_needed, eof_needed;
596 struct Packet pktout;
597 unsigned char *deferred_send_data;
598 int deferred_len, deferred_size;
601 * Gross hack: pscp will try to start SFTP but fall back to
602 * scp1 if that fails. This variable is the means by which
603 * scp.c can reach into the SSH code and find out which one it
609 * Used for username and password input.
611 char *userpass_input_buffer;
612 int userpass_input_buflen;
613 int userpass_input_bufpos;
614 int userpass_input_echo;
616 char *portfwd_strptr;
622 int v1_throttle_count;
625 int v1_stdout_throttling;
626 int v2_outgoing_sequence;
628 int ssh1_rdpkt_crstate;
629 int ssh2_rdpkt_crstate;
630 int do_ssh_init_crstate;
631 int ssh_gotdata_crstate;
632 int ssh1_protocol_crstate;
633 int do_ssh1_login_crstate;
634 int do_ssh2_transport_crstate;
635 int do_ssh2_authconn_crstate;
637 void *do_ssh_init_state;
638 void *do_ssh1_login_state;
639 void *do_ssh2_transport_state;
640 void *do_ssh2_authconn_state;
642 struct rdpkt1_state_tag rdpkt1_state;
643 struct rdpkt2_state_tag rdpkt2_state;
645 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
646 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
649 * We maintain a full _copy_ of a Config structure here, not
650 * merely a pointer to it. That way, when we're passed a new
651 * one for reconfiguration, we can check the differences and
652 * potentially reconfigure port forwardings etc in mid-session.
657 * Used to transfer data back from async agent callbacks.
659 void *agent_response;
660 int agent_response_len;
663 #define logevent(s) logevent(ssh->frontend, s)
665 /* logevent, only printf-formatted. */
666 static void logeventf(Ssh ssh, const char *fmt, ...)
672 buf = dupvprintf(fmt, ap);
678 #define bombout(msg) \
680 char *text = dupprintf msg; \
683 connection_fatal(ssh->frontend, "%s", text); \
687 static int ssh_channelcmp(void *av, void *bv)
689 struct ssh_channel *a = (struct ssh_channel *) av;
690 struct ssh_channel *b = (struct ssh_channel *) bv;
691 if (a->localid < b->localid)
693 if (a->localid > b->localid)
697 static int ssh_channelfind(void *av, void *bv)
699 unsigned *a = (unsigned *) av;
700 struct ssh_channel *b = (struct ssh_channel *) bv;
708 static int ssh_rportcmp_ssh1(void *av, void *bv)
710 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
711 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
713 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
714 return i < 0 ? -1 : +1;
715 if (a->dport > b->dport)
717 if (a->dport < b->dport)
722 static int ssh_rportcmp_ssh2(void *av, void *bv)
724 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
725 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
727 if (a->sport > b->sport)
729 if (a->sport < b->sport)
734 static int alloc_channel_id(Ssh ssh)
736 const unsigned CHANNEL_NUMBER_OFFSET = 256;
737 unsigned low, high, mid;
739 struct ssh_channel *c;
742 * First-fit allocation of channel numbers: always pick the
743 * lowest unused one. To do this, binary-search using the
744 * counted B-tree to find the largest channel ID which is in a
745 * contiguous sequence from the beginning. (Precisely
746 * everything in that sequence must have ID equal to its tree
747 * index plus CHANNEL_NUMBER_OFFSET.)
749 tsize = count234(ssh->channels);
753 while (high - low > 1) {
754 mid = (high + low) / 2;
755 c = index234(ssh->channels, mid);
756 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
757 low = mid; /* this one is fine */
759 high = mid; /* this one is past it */
762 * Now low points to either -1, or the tree index of the
763 * largest ID in the initial sequence.
766 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
767 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
769 return low + 1 + CHANNEL_NUMBER_OFFSET;
772 static void c_write(Ssh ssh, const char *buf, int len)
774 if ((flags & FLAG_STDERR)) {
776 for (i = 0; i < len; i++)
778 fputc(buf[i], stderr);
781 from_backend(ssh->frontend, 1, buf, len);
784 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
787 for (i = 0; i < len; i++) {
789 c_write(ssh, "\r\n", 2);
790 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
791 c_write(ssh, buf + i, 1);
795 static void c_write_str(Ssh ssh, const char *buf)
797 c_write(ssh, buf, strlen(buf));
801 * Collect incoming data in the incoming packet buffer.
802 * Decipher and verify the packet when it is completely read.
803 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
804 * Update the *data and *datalen variables.
805 * Return the additional nr of bytes needed, or 0 when
806 * a complete packet is available.
808 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
810 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
812 crBegin(ssh->ssh1_rdpkt_crstate);
817 ssh->pktin.length = 0;
819 for (st->i = st->len = 0; st->i < 4; st->i++) {
820 while ((*datalen) == 0)
822 st->len = (st->len << 8) + **data;
823 (*data)++, (*datalen)--;
826 st->pad = 8 - (st->len % 8);
827 st->biglen = st->len + st->pad;
828 ssh->pktin.length = st->len - 5;
830 if (ssh->pktin.maxlen < st->biglen) {
831 ssh->pktin.maxlen = st->biglen;
832 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
836 st->to_read = st->biglen;
837 st->p = ssh->pktin.data;
838 while (st->to_read > 0) {
839 st->chunk = st->to_read;
840 while ((*datalen) == 0)
841 crReturn(st->to_read);
842 if (st->chunk > (*datalen))
843 st->chunk = (*datalen);
844 memcpy(st->p, *data, st->chunk);
846 *datalen -= st->chunk;
848 st->to_read -= st->chunk;
851 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
853 bombout(("Network attack (CRC compensation) detected!"));
858 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
860 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
861 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
862 if (st->gotcrc != st->realcrc) {
863 bombout(("Incorrect CRC received on packet"));
867 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
868 ssh->pktin.savedpos = 0;
870 if (ssh->v1_compressing) {
871 unsigned char *decompblk;
873 if (!zlib_decompress_block(ssh->sc_comp_ctx,
874 ssh->pktin.body - 1, ssh->pktin.length + 1,
875 &decompblk, &decomplen)) {
876 bombout(("Zlib decompression encountered invalid data"));
880 if (ssh->pktin.maxlen < st->pad + decomplen) {
881 ssh->pktin.maxlen = st->pad + decomplen;
882 ssh->pktin.data = sresize(ssh->pktin.data,
883 ssh->pktin.maxlen + APIEXTRA,
885 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
888 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
890 ssh->pktin.length = decomplen - 1;
893 ssh->pktin.type = ssh->pktin.body[-1];
896 log_packet(ssh->logctx,
897 PKT_INCOMING, ssh->pktin.type,
898 ssh1_pkt_type(ssh->pktin.type),
899 ssh->pktin.body, ssh->pktin.length);
901 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
902 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
903 ssh->pktin.type == SSH1_MSG_DEBUG ||
904 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
905 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
906 long stringlen = GET_32BIT(ssh->pktin.body);
907 if (stringlen + 4 != ssh->pktin.length) {
908 bombout(("Received data packet with bogus string length"));
913 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
914 /* log debug message */
916 int stringlen = GET_32BIT(ssh->pktin.body);
917 strcpy(buf, "Remote debug message: ");
920 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
921 buf[8 + stringlen] = '\0';
924 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
929 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
930 /* log reason code in disconnect message */
932 unsigned msglen = GET_32BIT(ssh->pktin.body);
934 strcpy(buf, "Remote sent disconnect: ");
935 nowlen = strlen(buf);
936 if (msglen > sizeof(buf) - nowlen - 1)
937 msglen = sizeof(buf) - nowlen - 1;
938 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
939 buf[nowlen + msglen] = '\0';
940 /* logevent(buf); (this is now done within the bombout macro) */
941 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
948 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
950 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
952 crBegin(ssh->ssh2_rdpkt_crstate);
956 ssh->pktin.length = 0;
958 st->cipherblk = ssh->sccipher->blksize;
961 if (st->cipherblk < 8)
964 if (ssh->pktin.maxlen < st->cipherblk) {
965 ssh->pktin.maxlen = st->cipherblk;
966 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
971 * Acquire and decrypt the first block of the packet. This will
972 * contain the length and padding details.
974 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
975 while ((*datalen) == 0)
976 crReturn(st->cipherblk - st->i);
977 ssh->pktin.data[st->i] = *(*data)++;
982 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
983 ssh->pktin.data, st->cipherblk);
986 * Now get the length and padding figures.
988 st->len = GET_32BIT(ssh->pktin.data);
989 st->pad = ssh->pktin.data[4];
992 * _Completely_ silly lengths should be stomped on before they
993 * do us any more damage.
995 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
996 bombout(("Incoming packet was garbled on decryption"));
1001 * This enables us to deduce the payload length.
1003 st->payload = st->len - st->pad - 1;
1005 ssh->pktin.length = st->payload + 5;
1008 * So now we can work out the total packet length.
1010 st->packetlen = st->len + 4;
1011 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1014 * Adjust memory allocation if packet is too big.
1016 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1017 ssh->pktin.maxlen = st->packetlen + st->maclen;
1018 ssh->pktin.data = sresize(ssh->pktin.data,
1019 ssh->pktin.maxlen + APIEXTRA,
1024 * Read and decrypt the remainder of the packet.
1026 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1028 while ((*datalen) == 0)
1029 crReturn(st->packetlen + st->maclen - st->i);
1030 ssh->pktin.data[st->i] = *(*data)++;
1033 /* Decrypt everything _except_ the MAC. */
1035 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1036 ssh->pktin.data + st->cipherblk,
1037 st->packetlen - st->cipherblk);
1043 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1044 st->incoming_sequence)) {
1045 bombout(("Incorrect MAC received on packet"));
1048 st->incoming_sequence++; /* whether or not we MACed */
1051 * Decompress packet payload.
1054 unsigned char *newpayload;
1057 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1058 ssh->pktin.data + 5, ssh->pktin.length - 5,
1059 &newpayload, &newlen)) {
1060 if (ssh->pktin.maxlen < newlen + 5) {
1061 ssh->pktin.maxlen = newlen + 5;
1062 ssh->pktin.data = sresize(ssh->pktin.data,
1063 ssh->pktin.maxlen + APIEXTRA,
1066 ssh->pktin.length = 5 + newlen;
1067 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1072 ssh->pktin.savedpos = 6;
1073 ssh->pktin.body = ssh->pktin.data;
1074 ssh->pktin.type = ssh->pktin.data[5];
1077 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1078 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1079 ssh->pktin.data+6, ssh->pktin.length-6);
1081 switch (ssh->pktin.type) {
1083 * These packets we must handle instantly.
1085 case SSH2_MSG_DISCONNECT:
1087 /* log reason code in disconnect message */
1090 int reason = GET_32BIT(ssh->pktin.data + 6);
1091 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1093 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1094 buf = dupprintf("Received disconnect message (%s)",
1095 ssh2_disconnect_reasons[reason]);
1097 buf = dupprintf("Received disconnect message (unknown"
1098 " type %d)", reason);
1102 buf = dupprintf("Disconnection message text: %n%.*s",
1103 &nowlen, msglen, ssh->pktin.data + 14);
1105 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1107 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1108 ssh2_disconnect_reasons[reason] : "unknown",
1114 case SSH2_MSG_IGNORE:
1116 case SSH2_MSG_DEBUG:
1118 /* log the debug message */
1120 /* int display = ssh->pktin.body[6]; */
1121 int stringlen = GET_32BIT(ssh->pktin.data+7);
1123 strcpy(buf, "Remote debug message: ");
1124 prefix = strlen(buf);
1125 if (stringlen > (int)(sizeof(buf)-prefix-1))
1126 stringlen = sizeof(buf)-prefix-1;
1127 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1128 buf[prefix + stringlen] = '\0';
1131 goto next_packet; /* FIXME: print the debug message */
1134 * These packets we need do nothing about here.
1136 case SSH2_MSG_UNIMPLEMENTED:
1137 case SSH2_MSG_SERVICE_REQUEST:
1138 case SSH2_MSG_SERVICE_ACCEPT:
1139 case SSH2_MSG_KEXINIT:
1140 case SSH2_MSG_NEWKEYS:
1141 case SSH2_MSG_KEXDH_INIT:
1142 case SSH2_MSG_KEXDH_REPLY:
1143 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1144 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1145 case SSH2_MSG_KEX_DH_GEX_INIT:
1146 case SSH2_MSG_KEX_DH_GEX_REPLY:
1147 case SSH2_MSG_USERAUTH_REQUEST:
1148 case SSH2_MSG_USERAUTH_FAILURE:
1149 case SSH2_MSG_USERAUTH_SUCCESS:
1150 case SSH2_MSG_USERAUTH_BANNER:
1151 case SSH2_MSG_USERAUTH_PK_OK:
1152 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1153 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1154 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1155 case SSH2_MSG_GLOBAL_REQUEST:
1156 case SSH2_MSG_REQUEST_SUCCESS:
1157 case SSH2_MSG_REQUEST_FAILURE:
1158 case SSH2_MSG_CHANNEL_OPEN:
1159 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1160 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1161 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1162 case SSH2_MSG_CHANNEL_DATA:
1163 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1164 case SSH2_MSG_CHANNEL_EOF:
1165 case SSH2_MSG_CHANNEL_CLOSE:
1166 case SSH2_MSG_CHANNEL_REQUEST:
1167 case SSH2_MSG_CHANNEL_SUCCESS:
1168 case SSH2_MSG_CHANNEL_FAILURE:
1172 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1175 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1176 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1184 static void ssh1_pktout_size(Ssh ssh, int len)
1188 len += 5; /* type and CRC */
1189 pad = 8 - (len % 8);
1192 ssh->pktout.length = len - 5;
1193 if (ssh->pktout.maxlen < biglen) {
1194 ssh->pktout.maxlen = biglen;
1196 /* Allocate enough buffer space for extra block
1197 * for MS CryptEncrypt() */
1198 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1201 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1205 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1208 static void s_wrpkt_start(Ssh ssh, int type, int len)
1210 ssh1_pktout_size(ssh, len);
1211 ssh->pktout.type = type;
1214 static int s_wrpkt_prepare(Ssh ssh)
1220 * XXX various versions of SC (including 8.8.4) screw up the
1221 * register allocation in this function and use the same register
1222 * (D6) for len and as a temporary, with predictable results. The
1223 * following sledgehammer prevents this.
1229 ssh->pktout.body[-1] = ssh->pktout.type;
1232 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1233 ssh1_pkt_type(ssh->pktout.type),
1234 ssh->pktout.body, ssh->pktout.length);
1236 if (ssh->v1_compressing) {
1237 unsigned char *compblk;
1239 zlib_compress_block(ssh->cs_comp_ctx,
1240 ssh->pktout.body - 1, ssh->pktout.length + 1,
1241 &compblk, &complen);
1242 ssh1_pktout_size(ssh, complen - 1);
1243 memcpy(ssh->pktout.body - 1, compblk, complen);
1247 len = ssh->pktout.length + 5; /* type and CRC */
1248 pad = 8 - (len % 8);
1251 for (i = 0; i < pad; i++)
1252 ssh->pktout.data[i + 4] = random_byte();
1253 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1254 PUT_32BIT(ssh->pktout.data + biglen, crc);
1255 PUT_32BIT(ssh->pktout.data, len);
1258 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1263 static void s_wrpkt(Ssh ssh)
1266 len = s_wrpkt_prepare(ssh);
1267 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1268 if (backlog > SSH_MAX_BACKLOG)
1269 ssh_throttle_all(ssh, 1, backlog);
1272 static void s_wrpkt_defer(Ssh ssh)
1275 len = s_wrpkt_prepare(ssh);
1276 if (ssh->deferred_len + len > ssh->deferred_size) {
1277 ssh->deferred_size = ssh->deferred_len + len + 128;
1278 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1282 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1283 ssh->deferred_len += len;
1287 * Construct a packet with the specified contents.
1289 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1291 unsigned char *p, *argp, argchar;
1292 unsigned long argint;
1293 int pktlen, argtype, arglen;
1297 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1300 (void) va_arg(ap1, int);
1304 (void) va_arg(ap1, int);
1308 (void) va_arg(ap1, unsigned char *);
1309 arglen = va_arg(ap1, int);
1313 argp = va_arg(ap1, unsigned char *);
1314 arglen = strlen((char *)argp);
1315 pktlen += 4 + arglen;
1318 bn = va_arg(ap1, Bignum);
1319 pktlen += ssh1_bignum_length(bn);
1326 s_wrpkt_start(ssh, pkttype, pktlen);
1327 p = ssh->pktout.body;
1329 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1332 argint = va_arg(ap2, int);
1333 PUT_32BIT(p, argint);
1337 argchar = (unsigned char) va_arg(ap2, int);
1342 argp = va_arg(ap2, unsigned char *);
1343 arglen = va_arg(ap2, int);
1344 memcpy(p, argp, arglen);
1348 argp = va_arg(ap2, unsigned char *);
1349 arglen = strlen((char *)argp);
1350 PUT_32BIT(p, arglen);
1351 memcpy(p + 4, argp, arglen);
1355 bn = va_arg(ap2, Bignum);
1356 p += ssh1_write_bignum(p, bn);
1362 static void send_packet(Ssh ssh, int pkttype, ...)
1365 va_start(ap1, pkttype);
1366 va_start(ap2, pkttype);
1367 construct_packet(ssh, pkttype, ap1, ap2);
1371 static void defer_packet(Ssh ssh, int pkttype, ...)
1374 va_start(ap1, pkttype);
1375 va_start(ap2, pkttype);
1376 construct_packet(ssh, pkttype, ap1, ap2);
1380 static int ssh_versioncmp(char *a, char *b)
1383 unsigned long av, bv;
1385 av = strtoul(a, &ae, 10);
1386 bv = strtoul(b, &be, 10);
1388 return (av < bv ? -1 : +1);
1393 av = strtoul(ae, &ae, 10);
1394 bv = strtoul(be, &be, 10);
1396 return (av < bv ? -1 : +1);
1401 * Utility routines for putting an SSH-protocol `string' and
1402 * `uint32' into a SHA state.
1405 static void sha_string(SHA_State * s, void *str, int len)
1407 unsigned char lenblk[4];
1408 PUT_32BIT(lenblk, len);
1409 SHA_Bytes(s, lenblk, 4);
1410 SHA_Bytes(s, str, len);
1413 static void sha_uint32(SHA_State * s, unsigned i)
1415 unsigned char intblk[4];
1416 PUT_32BIT(intblk, i);
1417 SHA_Bytes(s, intblk, 4);
1421 * SSH2 packet construction functions.
1423 static void ssh2_pkt_ensure(Ssh ssh, int length)
1425 if (ssh->pktout.maxlen < length) {
1426 ssh->pktout.maxlen = length + 256;
1427 ssh->pktout.data = sresize(ssh->pktout.data,
1428 ssh->pktout.maxlen + APIEXTRA,
1430 if (!ssh->pktout.data)
1431 fatalbox("Out of memory");
1434 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1436 ssh->pktout.length += len;
1437 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1438 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1440 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1442 ssh2_pkt_adddata(ssh, &byte, 1);
1444 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1446 ssh->pktout.length = 5;
1447 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1449 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1451 ssh2_pkt_adddata(ssh, &value, 1);
1453 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1456 PUT_32BIT(x, value);
1457 ssh2_pkt_adddata(ssh, x, 4);
1459 static void ssh2_pkt_addstring_start(Ssh ssh)
1461 ssh2_pkt_adduint32(ssh, 0);
1462 ssh->pktout.savedpos = ssh->pktout.length;
1464 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1466 ssh2_pkt_adddata(ssh, data, strlen(data));
1467 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1468 ssh->pktout.length - ssh->pktout.savedpos);
1470 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1472 ssh2_pkt_adddata(ssh, data, len);
1473 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1474 ssh->pktout.length - ssh->pktout.savedpos);
1476 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1478 ssh2_pkt_addstring_start(ssh);
1479 ssh2_pkt_addstring_str(ssh, data);
1481 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1484 int i, n = (bignum_bitcount(b) + 7) / 8;
1485 p = snewn(n + 1, unsigned char);
1487 fatalbox("out of memory");
1489 for (i = 1; i <= n; i++)
1490 p[i] = bignum_byte(b, n - i);
1492 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1494 memmove(p, p + i, n + 1 - i);
1498 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1502 p = ssh2_mpint_fmt(b, &len);
1503 ssh2_pkt_addstring_start(ssh);
1504 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1509 * Construct an SSH2 final-form packet: compress it, encrypt it,
1510 * put the MAC on it. Final packet, ready to be sent, is stored in
1511 * ssh->pktout.data. Total length is returned.
1513 static int ssh2_pkt_construct(Ssh ssh)
1515 int cipherblk, maclen, padding, i;
1518 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1519 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1520 ssh->pktout.data + 6, ssh->pktout.length - 6);
1523 * Compress packet payload.
1526 unsigned char *newpayload;
1529 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1530 ssh->pktout.length - 5,
1531 &newpayload, &newlen)) {
1532 ssh->pktout.length = 5;
1533 ssh2_pkt_adddata(ssh, newpayload, newlen);
1539 * Add padding. At least four bytes, and must also bring total
1540 * length (minus MAC) up to a multiple of the block size.
1542 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1543 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1546 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1547 maclen = ssh->csmac ? ssh->csmac->len : 0;
1548 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1549 ssh->pktout.data[4] = padding;
1550 for (i = 0; i < padding; i++)
1551 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1552 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1554 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1555 ssh->pktout.length + padding,
1556 ssh->v2_outgoing_sequence);
1557 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1560 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1561 ssh->pktout.data, ssh->pktout.length + padding);
1563 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1564 return ssh->pktout.length + padding + maclen;
1568 * Construct and send an SSH2 packet immediately.
1570 static void ssh2_pkt_send(Ssh ssh)
1574 len = ssh2_pkt_construct(ssh);
1575 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1576 if (backlog > SSH_MAX_BACKLOG)
1577 ssh_throttle_all(ssh, 1, backlog);
1581 * Construct an SSH2 packet and add it to a deferred data block.
1582 * Useful for sending multiple packets in a single sk_write() call,
1583 * to prevent a traffic-analysing listener from being able to work
1584 * out the length of any particular packet (such as the password
1587 * Note that because SSH2 sequence-numbers its packets, this can
1588 * NOT be used as an m4-style `defer' allowing packets to be
1589 * constructed in one order and sent in another.
1591 static void ssh2_pkt_defer(Ssh ssh)
1593 int len = ssh2_pkt_construct(ssh);
1594 if (ssh->deferred_len + len > ssh->deferred_size) {
1595 ssh->deferred_size = ssh->deferred_len + len + 128;
1596 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1600 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1601 ssh->deferred_len += len;
1605 * Send the whole deferred data block constructed by
1606 * ssh2_pkt_defer() or SSH1's defer_packet().
1608 static void ssh_pkt_defersend(Ssh ssh)
1611 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1613 ssh->deferred_len = ssh->deferred_size = 0;
1614 sfree(ssh->deferred_send_data);
1615 ssh->deferred_send_data = NULL;
1616 if (backlog > SSH_MAX_BACKLOG)
1617 ssh_throttle_all(ssh, 1, backlog);
1621 void bndebug(char *string, Bignum b)
1625 p = ssh2_mpint_fmt(b, &len);
1626 debug(("%s", string));
1627 for (i = 0; i < len; i++)
1628 debug((" %02x", p[i]));
1634 static void sha_mpint(SHA_State * s, Bignum b)
1638 p = ssh2_mpint_fmt(b, &len);
1639 sha_string(s, p, len);
1644 * Packet decode functions for both SSH1 and SSH2.
1646 static unsigned long ssh_pkt_getuint32(Ssh ssh)
1648 unsigned long value;
1649 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1650 return 0; /* arrgh, no way to decline (FIXME?) */
1651 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1652 ssh->pktin.savedpos += 4;
1655 static int ssh2_pkt_getbool(Ssh ssh)
1657 unsigned long value;
1658 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1659 return 0; /* arrgh, no way to decline (FIXME?) */
1660 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
1661 ssh->pktin.savedpos++;
1664 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
1669 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1671 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1675 ssh->pktin.savedpos += 4;
1676 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1678 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
1679 ssh->pktin.savedpos += *length;
1681 static void *ssh_pkt_getdata(Ssh ssh, int length)
1683 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1685 ssh->pktin.savedpos += length;
1686 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1688 static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1689 unsigned char **keystr)
1693 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1694 ssh->pktin.length - ssh->pktin.savedpos,
1700 ssh->pktin.savedpos += j;
1701 assert(ssh->pktin.savedpos < ssh->pktin.length);
1705 static Bignum ssh1_pkt_getmp(Ssh ssh)
1710 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1711 ssh->pktin.length - ssh->pktin.savedpos, &b);
1716 ssh->pktin.savedpos += j;
1719 static Bignum ssh2_pkt_getmp(Ssh ssh)
1725 ssh_pkt_getstring(ssh, &p, &length);
1729 bombout(("internal error: Can't handle negative mpints"));
1732 b = bignum_from_bytes((unsigned char *)p, length);
1737 * Helper function to add an SSH2 signature blob to a packet.
1738 * Expects to be shown the public key blob as well as the signature
1739 * blob. Normally works just like ssh2_pkt_addstring, but will
1740 * fiddle with the signature packet if necessary for
1741 * BUG_SSH2_RSA_PADDING.
1743 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1744 void *sigblob_v, int sigblob_len)
1746 unsigned char *pkblob = (unsigned char *)pkblob_v;
1747 unsigned char *sigblob = (unsigned char *)sigblob_v;
1749 /* dmemdump(pkblob, pkblob_len); */
1750 /* dmemdump(sigblob, sigblob_len); */
1753 * See if this is in fact an ssh-rsa signature and a buggy
1754 * server; otherwise we can just do this the easy way.
1756 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1757 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1758 int pos, len, siglen;
1761 * Find the byte length of the modulus.
1764 pos = 4+7; /* skip over "ssh-rsa" */
1765 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1766 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1767 pos += 4; /* find modulus itself */
1768 while (len > 0 && pkblob[pos] == 0)
1770 /* debug(("modulus length is %d\n", len)); */
1773 * Now find the signature integer.
1775 pos = 4+7; /* skip over "ssh-rsa" */
1776 siglen = GET_32BIT(sigblob+pos);
1777 /* debug(("signature length is %d\n", siglen)); */
1779 if (len != siglen) {
1780 unsigned char newlen[4];
1781 ssh2_pkt_addstring_start(ssh);
1782 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1783 /* dmemdump(sigblob, pos); */
1784 pos += 4; /* point to start of actual sig */
1785 PUT_32BIT(newlen, len);
1786 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1787 /* dmemdump(newlen, 4); */
1789 while (len-- > siglen) {
1790 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1791 /* dmemdump(newlen, 1); */
1793 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1794 /* dmemdump(sigblob+pos, siglen); */
1798 /* Otherwise fall through and do it the easy way. */
1801 ssh2_pkt_addstring_start(ssh);
1802 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1806 * Examine the remote side's version string and compare it against
1807 * a list of known buggy implementations.
1809 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1811 char *imp; /* pointer to implementation part */
1813 imp += strcspn(imp, "-");
1815 imp += strcspn(imp, "-");
1818 ssh->remote_bugs = 0;
1820 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1821 (ssh->cfg.sshbug_ignore1 == AUTO &&
1822 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1823 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1824 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1825 !strcmp(imp, "OSU_1.4alpha3")))) {
1827 * These versions don't support SSH1_MSG_IGNORE, so we have
1828 * to use a different defence against password length
1831 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1832 logevent("We believe remote version has SSH1 ignore bug");
1835 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1836 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1837 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1839 * These versions need a plain password sent; they can't
1840 * handle having a null and a random length of data after
1843 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1844 logevent("We believe remote version needs a plain SSH1 password");
1847 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1848 (ssh->cfg.sshbug_rsa1 == AUTO &&
1849 (!strcmp(imp, "Cisco-1.25")))) {
1851 * These versions apparently have no clue whatever about
1852 * RSA authentication and will panic and die if they see
1853 * an AUTH_RSA message.
1855 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1856 logevent("We believe remote version can't handle RSA authentication");
1859 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1860 (ssh->cfg.sshbug_hmac2 == AUTO &&
1861 !wc_match("* VShell", imp) &&
1862 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1863 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1864 wc_match("2.1 *", imp)))) {
1866 * These versions have the HMAC bug.
1868 ssh->remote_bugs |= BUG_SSH2_HMAC;
1869 logevent("We believe remote version has SSH2 HMAC bug");
1872 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1873 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1874 !wc_match("* VShell", imp) &&
1875 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1877 * These versions have the key-derivation bug (failing to
1878 * include the literal shared secret in the hashes that
1879 * generate the keys).
1881 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1882 logevent("We believe remote version has SSH2 key-derivation bug");
1885 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1886 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1887 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1888 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1890 * These versions have the SSH2 RSA padding bug.
1892 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1893 logevent("We believe remote version has SSH2 RSA padding bug");
1896 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1897 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1898 wc_match("OpenSSH_2.[0-2]*", imp))) {
1900 * These versions have the SSH2 session-ID bug in
1901 * public-key authentication.
1903 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1904 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1907 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1909 * User specified the SSH2 DH GEX bug.
1911 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1912 logevent("We believe remote version has SSH2 DH group exchange bug");
1916 static int do_ssh_init(Ssh ssh, unsigned char c)
1918 struct do_ssh_init_state {
1926 crState(do_ssh_init_state);
1928 crBegin(ssh->do_ssh_init_crstate);
1930 /* Search for the string "SSH-" in the input. */
1933 static const int transS[] = { 1, 2, 2, 1 };
1934 static const int transH[] = { 0, 0, 3, 0 };
1935 static const int transminus[] = { 0, 0, 0, -1 };
1937 s->i = transS[s->i];
1939 s->i = transH[s->i];
1941 s->i = transminus[s->i];
1946 crReturn(1); /* get another character */
1950 s->vstring = snewn(s->vstrsize, char);
1951 strcpy(s->vstring, "SSH-");
1955 crReturn(1); /* get another char */
1956 if (s->vslen >= s->vstrsize - 1) {
1958 s->vstring = sresize(s->vstring, s->vstrsize, char);
1960 s->vstring[s->vslen++] = c;
1963 s->version[s->i] = '\0';
1965 } else if (s->i < sizeof(s->version) - 1)
1966 s->version[s->i++] = c;
1967 } else if (c == '\012')
1971 ssh->agentfwd_enabled = FALSE;
1972 ssh->rdpkt2_state.incoming_sequence = 0;
1974 s->vstring[s->vslen] = 0;
1975 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1978 vlog = snewn(20 + s->vslen, char);
1979 sprintf(vlog, "Server version: %s", s->vstring);
1983 ssh_detect_bugs(ssh, s->vstring);
1986 * Decide which SSH protocol version to support.
1989 /* Anything strictly below "2.0" means protocol 1 is supported. */
1990 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1991 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1992 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1994 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1995 bombout(("SSH protocol version 1 required by user but not provided by server"));
1998 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1999 bombout(("SSH protocol version 2 required by user but not provided by server"));
2003 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2007 char verstring[80], vlog[100];
2008 sprintf(verstring, "SSH-2.0-%s", sshver);
2009 SHA_Init(&ssh->exhashbase);
2011 * Hash our version string and their version string.
2013 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2014 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2015 sprintf(vlog, "We claim version: %s", verstring);
2017 strcat(verstring, "\012");
2018 logevent("Using SSH protocol version 2");
2019 sk_write(ssh->s, verstring, strlen(verstring));
2020 ssh->protocol = ssh2_protocol;
2022 ssh->s_rdpkt = ssh2_rdpkt;
2027 char verstring[80], vlog[100];
2028 sprintf(verstring, "SSH-%s-%s",
2029 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
2031 sprintf(vlog, "We claim version: %s", verstring);
2033 strcat(verstring, "\012");
2035 logevent("Using SSH protocol version 1");
2036 sk_write(ssh->s, verstring, strlen(verstring));
2037 ssh->protocol = ssh1_protocol;
2039 ssh->s_rdpkt = ssh1_rdpkt;
2041 update_specials_menu(ssh->frontend);
2042 ssh->state = SSH_STATE_BEFORE_SIZE;
2049 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2051 crBegin(ssh->ssh_gotdata_crstate);
2054 * To begin with, feed the characters one by one to the
2055 * protocol initialisation / selection function do_ssh_init().
2056 * When that returns 0, we're done with the initial greeting
2057 * exchange and can move on to packet discipline.
2060 int ret; /* need not be kept across crReturn */
2062 crReturnV; /* more data please */
2063 ret = do_ssh_init(ssh, *data);
2071 * We emerge from that loop when the initial negotiation is
2072 * over and we have selected an s_rdpkt function. Now pass
2073 * everything to s_rdpkt, and then pass the resulting packets
2074 * to the proper protocol handler.
2079 while (datalen > 0) {
2080 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2081 if (ssh->state == SSH_STATE_CLOSED) {
2084 ssh->protocol(ssh, NULL, 0, 1);
2085 if (ssh->state == SSH_STATE_CLOSED) {
2095 static void ssh_do_close(Ssh ssh)
2098 struct ssh_channel *c;
2100 ssh->state = SSH_STATE_CLOSED;
2106 * Now we must shut down any port and X forwardings going
2107 * through this connection.
2109 if (ssh->channels) {
2110 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2113 x11_close(c->u.x11.s);
2116 pfd_close(c->u.pfd.s);
2119 del234(ssh->channels, c);
2120 if (ssh->version == 2)
2121 bufchain_clear(&c->v.v2.outbuffer);
2127 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2130 Ssh ssh = (Ssh) plug;
2133 /* A socket error has occurred. */
2134 logevent(error_msg);
2135 connection_fatal(ssh->frontend, "%s", error_msg);
2137 /* Otherwise, the remote side closed the connection normally. */
2142 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2144 Ssh ssh = (Ssh) plug;
2145 ssh_gotdata(ssh, (unsigned char *)data, len);
2146 if (ssh->state == SSH_STATE_CLOSED) {
2153 static void ssh_sent(Plug plug, int bufsize)
2155 Ssh ssh = (Ssh) plug;
2157 * If the send backlog on the SSH socket itself clears, we
2158 * should unthrottle the whole world if it was throttled.
2160 if (bufsize < SSH_MAX_BACKLOG)
2161 ssh_throttle_all(ssh, 0, bufsize);
2165 * Connect to specified host and port.
2166 * Returns an error message, or NULL on success.
2167 * Also places the canonical host name into `realhost'. It must be
2168 * freed by the caller.
2170 static const char *connect_to_host(Ssh ssh, char *host, int port,
2171 char **realhost, int nodelay, int keepalive)
2173 static const struct plug_function_table fn_table = {
2183 ssh->savedhost = snewn(1 + strlen(host), char);
2184 if (!ssh->savedhost)
2185 fatalbox("Out of memory");
2186 strcpy(ssh->savedhost, host);
2189 port = 22; /* default ssh port */
2190 ssh->savedport = port;
2195 logeventf(ssh, "Looking up host \"%s\"", host);
2196 addr = name_lookup(host, port, realhost, &ssh->cfg);
2197 if ((err = sk_addr_error(addr)) != NULL) {
2207 sk_getaddr(addr, addrbuf, 100);
2208 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2210 ssh->fn = &fn_table;
2211 ssh->s = new_connection(addr, *realhost, port,
2212 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2213 if ((err = sk_socket_error(ssh->s)) != NULL) {
2222 * Throttle or unthrottle the SSH connection.
2224 static void ssh1_throttle(Ssh ssh, int adjust)
2226 int old_count = ssh->v1_throttle_count;
2227 ssh->v1_throttle_count += adjust;
2228 assert(ssh->v1_throttle_count >= 0);
2229 if (ssh->v1_throttle_count && !old_count) {
2230 sk_set_frozen(ssh->s, 1);
2231 } else if (!ssh->v1_throttle_count && old_count) {
2232 sk_set_frozen(ssh->s, 0);
2237 * Throttle or unthrottle _all_ local data streams (for when sends
2238 * on the SSH connection itself back up).
2240 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2243 struct ssh_channel *c;
2245 if (enable == ssh->throttled_all)
2247 ssh->throttled_all = enable;
2248 ssh->overall_bufsize = bufsize;
2251 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2253 case CHAN_MAINSESSION:
2255 * This is treated separately, outside the switch.
2259 x11_override_throttle(c->u.x11.s, enable);
2262 /* Agent channels require no buffer management. */
2265 pfd_override_throttle(c->u.pfd.s, enable);
2272 * Username and password input, abstracted off into routines
2273 * reusable in several places - even between SSH1 and SSH2.
2276 /* Set up a username or password input loop on a given buffer. */
2277 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2279 ssh->userpass_input_buffer = buffer;
2280 ssh->userpass_input_buflen = buflen;
2281 ssh->userpass_input_bufpos = 0;
2282 ssh->userpass_input_echo = echo;
2286 * Process some terminal data in the course of username/password
2287 * input. Returns >0 for success (line of input returned in
2288 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2289 * for inconclusive (keep waiting for more input please).
2291 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2296 switch (c = *in++) {
2299 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2300 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2305 if (ssh->userpass_input_bufpos > 0) {
2306 if (ssh->userpass_input_echo)
2307 c_write_str(ssh, "\b \b");
2308 ssh->userpass_input_bufpos--;
2313 while (ssh->userpass_input_bufpos > 0) {
2314 if (ssh->userpass_input_echo)
2315 c_write_str(ssh, "\b \b");
2316 ssh->userpass_input_bufpos--;
2325 * This simplistic check for printability is disabled
2326 * when we're doing password input, because some people
2327 * have control characters in their passwords.o
2329 if ((!ssh->userpass_input_echo ||
2330 (c >= ' ' && c <= '~') ||
2331 ((unsigned char) c >= 160))
2332 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2333 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2334 if (ssh->userpass_input_echo)
2335 c_write(ssh, &c, 1);
2343 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2345 Ssh ssh = (Ssh) sshv;
2347 ssh->agent_response = reply;
2348 ssh->agent_response_len = replylen;
2350 if (ssh->version == 1)
2351 do_ssh1_login(ssh, NULL, -1, 0);
2353 do_ssh2_authconn(ssh, NULL, -1, 0);
2356 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2358 struct ssh_channel *c = (struct ssh_channel *)cv;
2360 void *sentreply = reply;
2363 /* Fake SSH_AGENT_FAILURE. */
2364 sentreply = "\0\0\0\1\5";
2367 if (ssh->version == 2) {
2368 ssh2_add_channel_data(c, sentreply, replylen);
2371 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2372 PKT_INT, c->remoteid,
2374 PKT_DATA, sentreply, replylen,
2382 * Handle the key exchange and user authentication phases.
2384 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2387 unsigned char cookie[8], *ptr;
2388 struct RSAKey servkey, hostkey;
2389 struct MD5Context md5c;
2390 struct do_ssh1_login_state {
2392 unsigned char *rsabuf, *keystr1, *keystr2;
2393 unsigned long supported_ciphers_mask, supported_auths_mask;
2394 int tried_publickey, tried_agent;
2395 int tis_auth_refused, ccard_auth_refused;
2396 unsigned char session_id[16];
2399 void *publickey_blob;
2400 int publickey_bloblen;
2406 unsigned char request[5], *response, *p;
2415 crState(do_ssh1_login_state);
2417 crBegin(ssh->do_ssh1_login_crstate);
2422 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2423 bombout(("Public key packet not received"));
2427 logevent("Received public keys");
2429 ptr = ssh_pkt_getdata(ssh, 8);
2431 bombout(("SSH1 public key packet stopped before random cookie"));
2434 memcpy(cookie, ptr, 8);
2436 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2437 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
2438 bombout(("SSH1 public key packet stopped before public keys"));
2443 * Log the host key fingerprint.
2447 logevent("Host key fingerprint is:");
2448 strcpy(logmsg, " ");
2449 hostkey.comment = NULL;
2450 rsa_fingerprint(logmsg + strlen(logmsg),
2451 sizeof(logmsg) - strlen(logmsg), &hostkey);
2455 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2456 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2457 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
2459 ssh->v1_local_protoflags =
2460 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2461 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2464 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2465 MD5Update(&md5c, s->keystr1, servkey.bytes);
2466 MD5Update(&md5c, cookie, 8);
2467 MD5Final(s->session_id, &md5c);
2469 for (i = 0; i < 32; i++)
2470 ssh->session_key[i] = random_byte();
2473 * Verify that the `bits' and `bytes' parameters match.
2475 if (hostkey.bits > hostkey.bytes * 8 ||
2476 servkey.bits > servkey.bytes * 8) {
2477 bombout(("SSH1 public keys were badly formatted"));
2481 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2483 s->rsabuf = snewn(s->len, unsigned char);
2485 fatalbox("Out of memory");
2488 * Verify the host key.
2492 * First format the key into a string.
2494 int len = rsastr_len(&hostkey);
2495 char fingerprint[100];
2496 char *keystr = snewn(len, char);
2498 fatalbox("Out of memory");
2499 rsastr_fmt(keystr, &hostkey);
2500 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2501 verify_ssh_host_key(ssh->frontend,
2502 ssh->savedhost, ssh->savedport, "rsa", keystr,
2507 for (i = 0; i < 32; i++) {
2508 s->rsabuf[i] = ssh->session_key[i];
2510 s->rsabuf[i] ^= s->session_id[i];
2513 if (hostkey.bytes > servkey.bytes) {
2514 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2516 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2518 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2520 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2523 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2527 logevent("Encrypted session key");
2530 int cipher_chosen = 0, warn = 0;
2531 char *cipher_string = NULL;
2533 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2534 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2535 if (next_cipher == CIPHER_WARN) {
2536 /* If/when we choose a cipher, warn about it */
2538 } else if (next_cipher == CIPHER_AES) {
2539 /* XXX Probably don't need to mention this. */
2540 logevent("AES not supported in SSH1, skipping");
2542 switch (next_cipher) {
2543 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2544 cipher_string = "3DES"; break;
2545 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2546 cipher_string = "Blowfish"; break;
2547 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2548 cipher_string = "single-DES"; break;
2550 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2554 if (!cipher_chosen) {
2555 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2556 bombout(("Server violates SSH 1 protocol by not "
2557 "supporting 3DES encryption"));
2559 /* shouldn't happen */
2560 bombout(("No supported ciphers found"));
2564 /* Warn about chosen cipher if necessary. */
2566 askcipher(ssh->frontend, cipher_string, 0);
2569 switch (s->cipher_type) {
2570 case SSH_CIPHER_3DES:
2571 logevent("Using 3DES encryption");
2573 case SSH_CIPHER_DES:
2574 logevent("Using single-DES encryption");
2576 case SSH_CIPHER_BLOWFISH:
2577 logevent("Using Blowfish encryption");
2581 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2582 PKT_CHAR, s->cipher_type,
2583 PKT_DATA, cookie, 8,
2584 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2585 PKT_DATA, s->rsabuf, s->len,
2586 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2588 logevent("Trying to enable encryption...");
2592 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2593 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2595 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2596 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2597 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2599 ssh->crcda_ctx = crcda_make_context();
2600 logevent("Installing CRC compensation attack detector");
2602 if (servkey.modulus) {
2603 sfree(servkey.modulus);
2604 servkey.modulus = NULL;
2606 if (servkey.exponent) {
2607 sfree(servkey.exponent);
2608 servkey.exponent = NULL;
2610 if (hostkey.modulus) {
2611 sfree(hostkey.modulus);
2612 hostkey.modulus = NULL;
2614 if (hostkey.exponent) {
2615 sfree(hostkey.exponent);
2616 hostkey.exponent = NULL;
2620 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2621 bombout(("Encryption not successfully enabled"));
2625 logevent("Successfully started encryption");
2629 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2630 if (ssh_get_line && !ssh_getline_pw_only) {
2631 if (!ssh_get_line("login as: ",
2632 s->username, sizeof(s->username), FALSE)) {
2634 * get_line failed to get a username.
2637 logevent("No username provided. Abandoning session.");
2638 ssh_closing((Plug)ssh, NULL, 0, 0);
2642 int ret; /* need not be kept over crReturn */
2643 c_write_str(ssh, "login as: ");
2646 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2648 crWaitUntil(!ispkt);
2649 ret = process_userpass_input(ssh, in, inlen);
2653 c_write_str(ssh, "\r\n");
2656 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2657 s->username[sizeof(s->username)-1] = '\0';
2660 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2662 char userlog[22 + sizeof(s->username)];
2663 sprintf(userlog, "Sent username \"%s\"", s->username);
2665 if (flags & FLAG_INTERACTIVE &&
2666 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2667 strcat(userlog, "\r\n");
2668 c_write_str(ssh, userlog);
2675 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2676 /* We must not attempt PK auth. Pretend we've already tried it. */
2677 s->tried_publickey = s->tried_agent = 1;
2679 s->tried_publickey = s->tried_agent = 0;
2681 s->tis_auth_refused = s->ccard_auth_refused = 0;
2682 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2683 if (!filename_is_null(ssh->cfg.keyfile)) {
2684 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2685 &s->publickey_blob, &s->publickey_bloblen, NULL))
2686 s->publickey_blob = NULL;
2688 s->publickey_blob = NULL;
2690 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2691 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2693 if (agent_exists() && !s->tried_agent) {
2695 * Attempt RSA authentication using Pageant.
2701 logevent("Pageant is running. Requesting keys.");
2703 /* Request the keys held by the agent. */
2704 PUT_32BIT(s->request, 1);
2705 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2706 if (!agent_query(s->request, 5, &r, &s->responselen,
2707 ssh_agent_callback, ssh)) {
2711 bombout(("Unexpected data from server while waiting"
2712 " for agent response"));
2715 } while (ispkt || inlen > 0);
2716 r = ssh->agent_response;
2717 s->responselen = ssh->agent_response_len;
2719 s->response = (unsigned char *) r;
2720 if (s->response && s->responselen >= 5 &&
2721 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2722 s->p = s->response + 5;
2723 s->nkeys = GET_32BIT(s->p);
2727 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2730 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2733 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2736 if (s->publickey_blob &&
2737 !memcmp(s->p, s->publickey_blob,
2738 s->publickey_bloblen)) {
2739 logevent("This key matches configured key file");
2740 s->tried_publickey = 1;
2745 do { /* do while (0) to make breaking easy */
2746 n = ssh1_read_bignum
2747 (s->p, s->responselen-(s->p-s->response),
2752 n = ssh1_read_bignum
2753 (s->p, s->responselen-(s->p-s->response),
2758 if (s->responselen - (s->p-s->response) < 4)
2760 s->commentlen = GET_32BIT(s->p);
2762 if (s->responselen - (s->p-s->response) <
2765 s->commentp = (char *)s->p;
2766 s->p += s->commentlen;
2770 logevent("Pageant key list packet was truncated");
2774 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2775 PKT_BIGNUM, s->key.modulus, PKT_END);
2777 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2778 logevent("Key refused");
2781 logevent("Received RSA challenge");
2782 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2783 bombout(("Server's RSA challenge was badly formatted"));
2788 char *agentreq, *q, *ret;
2791 len = 1 + 4; /* message type, bit count */
2792 len += ssh1_bignum_length(s->key.exponent);
2793 len += ssh1_bignum_length(s->key.modulus);
2794 len += ssh1_bignum_length(s->challenge);
2795 len += 16; /* session id */
2796 len += 4; /* response format */
2797 agentreq = snewn(4 + len, char);
2798 PUT_32BIT(agentreq, len);
2800 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2801 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2803 q += ssh1_write_bignum(q, s->key.exponent);
2804 q += ssh1_write_bignum(q, s->key.modulus);
2805 q += ssh1_write_bignum(q, s->challenge);
2806 memcpy(q, s->session_id, 16);
2808 PUT_32BIT(q, 1); /* response format */
2809 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2810 ssh_agent_callback, ssh)) {
2815 bombout(("Unexpected data from server"
2816 " while waiting for agent"
2820 } while (ispkt || inlen > 0);
2821 vret = ssh->agent_response;
2822 retlen = ssh->agent_response_len;
2827 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2828 logevent("Sending Pageant's response");
2829 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2830 PKT_DATA, ret + 5, 16,
2834 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2836 ("Pageant's response accepted");
2837 if (flags & FLAG_VERBOSE) {
2838 c_write_str(ssh, "Authenticated using"
2840 c_write(ssh, s->commentp,
2842 c_write_str(ssh, "\" from agent\r\n");
2847 ("Pageant's response not accepted");
2850 ("Pageant failed to answer challenge");
2854 logevent("No reply received from Pageant");
2857 freebn(s->key.exponent);
2858 freebn(s->key.modulus);
2859 freebn(s->challenge);
2868 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2869 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2871 if (ssh->cfg.try_tis_auth &&
2872 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2873 !s->tis_auth_refused) {
2874 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2875 logevent("Requested TIS authentication");
2876 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2878 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2879 logevent("TIS authentication declined");
2880 if (flags & FLAG_INTERACTIVE)
2881 c_write_str(ssh, "TIS authentication refused.\r\n");
2882 s->tis_auth_refused = 1;
2888 ssh_pkt_getstring(ssh, &challenge, &challengelen);
2890 bombout(("TIS challenge packet was badly formed"));
2893 logevent("Received TIS challenge");
2894 if (challengelen > sizeof(s->prompt) - 1)
2895 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2896 memcpy(s->prompt, challenge, challengelen);
2897 /* Prompt heuristic comes from OpenSSH */
2898 strncpy(s->prompt + challengelen,
2899 memchr(s->prompt, '\n', challengelen) ?
2900 "": "\r\nResponse: ",
2901 (sizeof s->prompt) - challengelen);
2902 s->prompt[(sizeof s->prompt) - 1] = '\0';
2905 if (ssh->cfg.try_tis_auth &&
2906 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2907 !s->ccard_auth_refused) {
2908 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2909 logevent("Requested CryptoCard authentication");
2910 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2912 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2913 logevent("CryptoCard authentication declined");
2914 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2915 s->ccard_auth_refused = 1;
2921 ssh_pkt_getstring(ssh, &challenge, &challengelen);
2923 bombout(("CryptoCard challenge packet was badly formed"));
2926 logevent("Received CryptoCard challenge");
2927 if (challengelen > sizeof(s->prompt) - 1)
2928 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2929 memcpy(s->prompt, challenge, challengelen);
2930 strncpy(s->prompt + challengelen,
2931 memchr(s->prompt, '\n', challengelen) ?
2932 "" : "\r\nResponse: ",
2933 sizeof(s->prompt) - challengelen);
2934 s->prompt[sizeof(s->prompt) - 1] = '\0';
2937 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2938 sprintf(s->prompt, "%.90s@%.90s's password: ",
2939 s->username, ssh->savedhost);
2941 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2942 char *comment = NULL;
2945 if (flags & FLAG_VERBOSE)
2946 c_write_str(ssh, "Trying public key authentication.\r\n");
2947 logeventf(ssh, "Trying public key \"%s\"",
2948 filename_to_str(&ssh->cfg.keyfile));
2949 type = key_type(&ssh->cfg.keyfile);
2950 if (type != SSH_KEYTYPE_SSH1) {
2951 sprintf(msgbuf, "Key is of wrong type (%s)",
2952 key_type_to_str(type));
2954 c_write_str(ssh, msgbuf);
2955 c_write_str(ssh, "\r\n");
2956 s->tried_publickey = 1;
2959 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2960 if (flags & FLAG_VERBOSE)
2961 c_write_str(ssh, "No passphrase required.\r\n");
2964 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2969 * Show password prompt, having first obtained it via a TIS
2970 * or CryptoCard exchange if we're doing TIS or CryptoCard
2974 if (!ssh_get_line(s->prompt, s->password,
2975 sizeof(s->password), TRUE)) {
2977 * get_line failed to get a password (for example
2978 * because one was supplied on the command line
2979 * which has already failed to work). Terminate.
2981 send_packet(ssh, SSH1_MSG_DISCONNECT,
2982 PKT_STR, "No more passwords available to try",
2984 logevent("Unable to authenticate");
2985 connection_fatal(ssh->frontend, "Unable to authenticate");
2986 ssh_closing((Plug)ssh, NULL, 0, 0);
2990 /* Prompt may have come from server. We've munged it a bit, so
2991 * we know it to be zero-terminated at least once. */
2992 int ret; /* need not be saved over crReturn */
2993 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2996 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2998 crWaitUntil(!ispkt);
2999 ret = process_userpass_input(ssh, in, inlen);
3003 c_write_str(ssh, "\r\n");
3007 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3009 * Try public key authentication with the specified
3012 s->tried_publickey = 1;
3015 const char *error = NULL;
3016 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3019 c_write_str(ssh, "Couldn't load private key from ");
3020 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3021 c_write_str(ssh, " (");
3022 c_write_str(ssh, error);
3023 c_write_str(ssh, ").\r\n");
3024 continue; /* go and try password */
3027 c_write_str(ssh, "Wrong passphrase.\r\n");
3028 s->tried_publickey = 0;
3029 continue; /* try again */
3034 * Send a public key attempt.
3036 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3037 PKT_BIGNUM, s->key.modulus, PKT_END);
3040 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3041 c_write_str(ssh, "Server refused our public key.\r\n");
3042 continue; /* go and try password */
3044 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3045 bombout(("Bizarre response to offer of public key"));
3051 unsigned char buffer[32];
3052 Bignum challenge, response;
3054 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3055 bombout(("Server's RSA challenge was badly formatted"));
3058 response = rsadecrypt(challenge, &s->key);
3059 freebn(s->key.private_exponent);/* burn the evidence */
3061 for (i = 0; i < 32; i++) {
3062 buffer[i] = bignum_byte(response, 31 - i);
3066 MD5Update(&md5c, buffer, 32);
3067 MD5Update(&md5c, s->session_id, 16);
3068 MD5Final(buffer, &md5c);
3070 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3071 PKT_DATA, buffer, 16, PKT_END);
3078 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3079 if (flags & FLAG_VERBOSE)
3080 c_write_str(ssh, "Failed to authenticate with"
3081 " our public key.\r\n");
3082 continue; /* go and try password */
3083 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3084 bombout(("Bizarre response to RSA authentication response"));
3088 break; /* we're through! */
3090 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3092 * Defence against traffic analysis: we send a
3093 * whole bunch of packets containing strings of
3094 * different lengths. One of these strings is the
3095 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3096 * The others are all random data in
3097 * SSH1_MSG_IGNORE packets. This way a passive
3098 * listener can't tell which is the password, and
3099 * hence can't deduce the password length.
3101 * Anybody with a password length greater than 16
3102 * bytes is going to have enough entropy in their
3103 * password that a listener won't find it _that_
3104 * much help to know how long it is. So what we'll
3107 * - if password length < 16, we send 15 packets
3108 * containing string lengths 1 through 15
3110 * - otherwise, we let N be the nearest multiple
3111 * of 8 below the password length, and send 8
3112 * packets containing string lengths N through
3113 * N+7. This won't obscure the order of
3114 * magnitude of the password length, but it will
3115 * introduce a bit of extra uncertainty.
3117 * A few servers (the old 1.2.18 through 1.2.22)
3118 * can't deal with SSH1_MSG_IGNORE. For these
3119 * servers, we need an alternative defence. We make
3120 * use of the fact that the password is interpreted
3121 * as a C string: so we can append a NUL, then some
3124 * One server (a Cisco one) can deal with neither
3125 * SSH1_MSG_IGNORE _nor_ a padded password string.
3126 * For this server we are left with no defences
3127 * against password length sniffing.
3129 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3131 * The server can deal with SSH1_MSG_IGNORE, so
3132 * we can use the primary defence.
3134 int bottom, top, pwlen, i;
3137 pwlen = strlen(s->password);
3139 bottom = 0; /* zero length passwords are OK! :-) */
3142 bottom = pwlen & ~7;
3146 assert(pwlen >= bottom && pwlen <= top);
3148 randomstr = snewn(top + 1, char);
3150 for (i = bottom; i <= top; i++) {
3152 defer_packet(ssh, s->pwpkt_type,
3153 PKT_STR, s->password, PKT_END);
3155 for (j = 0; j < i; j++) {
3157 randomstr[j] = random_byte();
3158 } while (randomstr[j] == '\0');
3160 randomstr[i] = '\0';
3161 defer_packet(ssh, SSH1_MSG_IGNORE,
3162 PKT_STR, randomstr, PKT_END);
3165 logevent("Sending password with camouflage packets");
3166 ssh_pkt_defersend(ssh);
3169 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3171 * The server can't deal with SSH1_MSG_IGNORE
3172 * but can deal with padded passwords, so we
3173 * can use the secondary defence.
3179 len = strlen(s->password);
3180 if (len < sizeof(string)) {
3182 strcpy(string, s->password);
3183 len++; /* cover the zero byte */
3184 while (len < sizeof(string)) {
3185 string[len++] = (char) random_byte();
3190 logevent("Sending length-padded password");
3191 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3192 PKT_DATA, ss, len, PKT_END);
3195 * The server has _both_
3196 * BUG_CHOKES_ON_SSH1_IGNORE and
3197 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3198 * therefore nothing we can do.
3201 len = strlen(s->password);
3202 logevent("Sending unpadded password");
3203 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3204 PKT_DATA, s->password, len, PKT_END);
3207 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
3210 logevent("Sent password");
3211 memset(s->password, 0, strlen(s->password));
3213 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3214 if (flags & FLAG_VERBOSE)
3215 c_write_str(ssh, "Access denied\r\n");
3216 logevent("Authentication refused");
3217 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3218 bombout(("Strange packet received, type %d", ssh->pktin.type));
3223 logevent("Authentication successful");
3228 void sshfwd_close(struct ssh_channel *c)
3232 if (ssh->state != SSH_STATE_SESSION) {
3233 assert(ssh->state == SSH_STATE_CLOSED);
3237 if (c && !c->closes) {
3239 * If the channel's remoteid is -1, we have sent
3240 * CHANNEL_OPEN for this channel, but it hasn't even been
3241 * acknowledged by the server. So we must set a close flag
3242 * on it now, and then when the server acks the channel
3243 * open, we can close it then.
3245 if (((int)c->remoteid) != -1) {
3246 if (ssh->version == 1) {
3247 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3250 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3251 ssh2_pkt_adduint32(ssh, c->remoteid);
3255 c->closes = 1; /* sent MSG_CLOSE */
3256 if (c->type == CHAN_X11) {
3258 logevent("Forwarded X11 connection terminated");
3259 } else if (c->type == CHAN_SOCKDATA ||
3260 c->type == CHAN_SOCKDATA_DORMANT) {
3262 logevent("Forwarded port closed");
3267 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3271 if (ssh->state != SSH_STATE_SESSION) {
3272 assert(ssh->state == SSH_STATE_CLOSED);
3276 if (ssh->version == 1) {
3277 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3278 PKT_INT, c->remoteid,
3279 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3281 * In SSH1 we can return 0 here - implying that forwarded
3282 * connections are never individually throttled - because
3283 * the only circumstance that can cause throttling will be
3284 * the whole SSH connection backing up, in which case
3285 * _everything_ will be throttled as a whole.
3289 ssh2_add_channel_data(c, buf, len);
3290 return ssh2_try_send(c);
3294 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3298 if (ssh->state != SSH_STATE_SESSION) {
3299 assert(ssh->state == SSH_STATE_CLOSED);
3303 if (ssh->version == 1) {
3304 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3305 c->v.v1.throttling = 0;
3306 ssh1_throttle(ssh, -1);
3309 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3313 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3315 crBegin(ssh->ssh1_protocol_crstate);
3319 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3322 if (ssh->state == SSH_STATE_CLOSED)
3325 if (ssh->cfg.agentfwd && agent_exists()) {
3326 logevent("Requesting agent forwarding");
3327 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3331 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3332 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3333 bombout(("Protocol confusion"));
3335 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3336 logevent("Agent forwarding refused");
3338 logevent("Agent forwarding enabled");
3339 ssh->agentfwd_enabled = TRUE;
3343 if (ssh->cfg.x11_forward) {
3344 char proto[20], data[64];
3345 logevent("Requesting X11 forwarding");
3346 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3347 data, sizeof(data), ssh->cfg.x11_auth);
3348 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3349 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3350 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3351 PKT_STR, proto, PKT_STR, data,
3352 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3355 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3356 PKT_STR, proto, PKT_STR, data, PKT_END);
3361 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3362 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3363 bombout(("Protocol confusion"));
3365 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3366 logevent("X11 forwarding refused");
3368 logevent("X11 forwarding enabled");
3369 ssh->X11_fwd_enabled = TRUE;
3376 int sport,dport,sserv,dserv;
3377 char sports[256], dports[256], saddr[256], host[256];
3379 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3380 /* Add port forwardings. */
3381 ssh->portfwd_strptr = ssh->cfg.portfwd;
3382 while (*ssh->portfwd_strptr) {
3383 type = *ssh->portfwd_strptr++;
3386 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3387 if (*ssh->portfwd_strptr == ':') {
3389 * We've seen a colon in the middle of the
3390 * source port number. This means that
3391 * everything we've seen until now is the
3392 * source _address_, so we'll move it into
3393 * saddr and start sports from the beginning
3396 ssh->portfwd_strptr++;
3398 strcpy(saddr, sports);
3401 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3405 if (*ssh->portfwd_strptr == '\t')
3406 ssh->portfwd_strptr++;
3408 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3409 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3412 if (*ssh->portfwd_strptr == ':')
3413 ssh->portfwd_strptr++;
3415 while (*ssh->portfwd_strptr) {
3416 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3419 ssh->portfwd_strptr++;
3420 dport = atoi(dports);
3424 dport = net_service_lookup(dports);
3426 logeventf(ssh, "Service lookup failed for"
3427 " destination port \"%s\"", dports);
3431 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3433 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3435 sport = atoi(sports);
3439 sport = net_service_lookup(sports);
3441 logeventf(ssh, "Service lookup failed for source"
3442 " port \"%s\"", sports);
3445 if (sport && dport) {
3447 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3448 sport, ssh, &ssh->cfg);
3449 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3450 " forwarding to %s:%.*s%.*s%d%.*s",
3451 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3452 (int)(*saddr?1:0), ":",
3453 (int)(sserv ? strlen(sports) : 0), sports,
3454 sserv, "(", sport, sserv, ")",
3456 (int)(dserv ? strlen(dports) : 0), dports,
3457 dserv, "(", dport, dserv, ")");
3458 } else if (type == 'D') {
3459 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3460 sport, ssh, &ssh->cfg);
3461 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3462 " doing SOCKS dynamic forwarding",
3463 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3464 (int)(*saddr?1:0), ":",
3465 (int)(sserv ? strlen(sports) : 0), sports,
3466 sserv, "(", sport, sserv, ")");
3468 struct ssh_rportfwd *pf;
3469 pf = snew(struct ssh_rportfwd);
3470 strcpy(pf->dhost, host);
3474 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3477 if (add234(ssh->rportfwds, pf) != pf) {
3479 "Duplicate remote port forwarding to %s:%d",
3483 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3484 " forward to %s:%.*s%.*s%d%.*s",
3485 (int)(sserv ? strlen(sports) : 0), sports,
3486 sserv, "(", sport, sserv, ")",
3488 (int)(dserv ? strlen(dports) : 0), dports,
3489 dserv, "(", dport, dserv, ")");
3490 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3498 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3499 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3500 bombout(("Protocol confusion"));
3502 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3503 c_write_str(ssh, "Server refused port"
3506 logevent("Remote port forwarding enabled");
3513 if (!ssh->cfg.nopty) {
3514 /* Unpick the terminal-speed string. */
3515 /* XXX perhaps we should allow no speeds to be sent. */
3516 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3517 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
3518 /* Send the pty request. */
3519 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3520 PKT_STR, ssh->cfg.termtype,
3521 PKT_INT, ssh->term_height,
3522 PKT_INT, ssh->term_width,
3523 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
3524 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3525 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
3526 PKT_CHAR, 0, PKT_END);
3527 ssh->state = SSH_STATE_INTERMED;
3531 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3532 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3533 bombout(("Protocol confusion"));
3535 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3536 c_write_str(ssh, "Server refused to allocate pty\r\n");
3537 ssh->editing = ssh->echoing = 1;
3539 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
3540 ssh->ospeed, ssh->ispeed);
3542 ssh->editing = ssh->echoing = 1;
3545 if (ssh->cfg.compression) {
3546 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3550 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3551 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3552 bombout(("Protocol confusion"));
3554 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3555 c_write_str(ssh, "Server refused to compress\r\n");
3557 logevent("Started compression");
3558 ssh->v1_compressing = TRUE;
3559 ssh->cs_comp_ctx = zlib_compress_init();
3560 logevent("Initialised zlib (RFC1950) compression");
3561 ssh->sc_comp_ctx = zlib_decompress_init();
3562 logevent("Initialised zlib (RFC1950) decompression");
3566 * Start the shell or command.
3568 * Special case: if the first-choice command is an SSH2
3569 * subsystem (hence not usable here) and the second choice
3570 * exists, we fall straight back to that.
3573 char *cmd = ssh->cfg.remote_cmd_ptr;
3575 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3576 cmd = ssh->cfg.remote_cmd_ptr2;
3577 ssh->fallback_cmd = TRUE;
3580 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3582 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3583 logevent("Started session");
3586 ssh->state = SSH_STATE_SESSION;
3587 if (ssh->size_needed)
3588 ssh_size(ssh, ssh->term_width, ssh->term_height);
3589 if (ssh->eof_needed)
3590 ssh_special(ssh, TS_EOF);
3593 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3595 ssh->channels = newtree234(ssh_channelcmp);
3599 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3600 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3602 int stringlen, bufsize;
3604 ssh_pkt_getstring(ssh, &string, &stringlen);
3605 if (string == NULL) {
3606 bombout(("Incoming terminal data packet was badly formed"));
3611 from_backend(ssh->frontend,
3612 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3614 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3615 ssh->v1_stdout_throttling = 1;
3616 ssh1_throttle(ssh, +1);
3618 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3619 ssh_closing((Plug)ssh, NULL, 0, 0);
3620 logevent("Received disconnect request");
3622 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3623 /* Remote side is trying to open a channel to talk to our
3624 * X-Server. Give them back a local channel number. */
3625 struct ssh_channel *c;
3626 int remoteid = ssh_pkt_getuint32(ssh);
3628 logevent("Received X11 connect request");
3629 /* Refuse if X11 forwarding is disabled. */
3630 if (!ssh->X11_fwd_enabled) {
3631 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3632 PKT_INT, remoteid, PKT_END);
3633 logevent("Rejected X11 connect request");
3635 c = snew(struct ssh_channel);
3638 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3639 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3640 logevent("Opening X11 forward connection failed");
3642 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3643 PKT_INT, remoteid, PKT_END);
3646 ("Opening X11 forward connection succeeded");
3647 c->remoteid = remoteid;
3648 c->localid = alloc_channel_id(ssh);
3650 c->v.v1.throttling = 0;
3651 c->type = CHAN_X11; /* identify channel type */
3652 add234(ssh->channels, c);
3653 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3654 PKT_INT, c->remoteid, PKT_INT,
3655 c->localid, PKT_END);
3656 logevent("Opened X11 forward channel");
3659 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3660 /* Remote side is trying to open a channel to talk to our
3661 * agent. Give them back a local channel number. */
3662 struct ssh_channel *c;
3663 int remoteid = ssh_pkt_getuint32(ssh);
3665 /* Refuse if agent forwarding is disabled. */
3666 if (!ssh->agentfwd_enabled) {
3667 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3668 PKT_INT, remoteid, PKT_END);
3670 c = snew(struct ssh_channel);
3672 c->remoteid = remoteid;
3673 c->localid = alloc_channel_id(ssh);
3675 c->v.v1.throttling = 0;
3676 c->type = CHAN_AGENT; /* identify channel type */
3677 c->u.a.lensofar = 0;
3678 add234(ssh->channels, c);
3679 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3680 PKT_INT, c->remoteid, PKT_INT, c->localid,
3683 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3684 /* Remote side is trying to open a channel to talk to a
3685 * forwarded port. Give them back a local channel number. */
3686 struct ssh_channel *c;
3687 struct ssh_rportfwd pf;
3690 char *host, buf[1024];
3692 c = snew(struct ssh_channel);
3695 remoteid = ssh_pkt_getuint32(ssh);
3696 ssh_pkt_getstring(ssh, &host, &hostsize);
3697 port = ssh_pkt_getuint32(ssh);
3699 if (hostsize >= lenof(pf.dhost))
3700 hostsize = lenof(pf.dhost)-1;
3701 memcpy(pf.dhost, host, hostsize);
3702 pf.dhost[hostsize] = '\0';
3705 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3706 sprintf(buf, "Rejected remote port open request for %s:%d",
3709 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3710 PKT_INT, remoteid, PKT_END);
3712 sprintf(buf, "Received remote port open request for %s:%d",
3715 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3719 sprintf(buf, "Port open failed: %s", e);
3722 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3723 PKT_INT, remoteid, PKT_END);
3725 c->remoteid = remoteid;
3726 c->localid = alloc_channel_id(ssh);
3728 c->v.v1.throttling = 0;
3729 c->type = CHAN_SOCKDATA; /* identify channel type */
3730 add234(ssh->channels, c);
3731 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3732 PKT_INT, c->remoteid, PKT_INT,
3733 c->localid, PKT_END);
3734 logevent("Forwarded port opened successfully");
3738 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3739 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3740 unsigned int localid = ssh_pkt_getuint32(ssh);
3741 struct ssh_channel *c;
3743 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3744 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3745 c->remoteid = localid;
3746 c->type = CHAN_SOCKDATA;
3747 c->v.v1.throttling = 0;
3748 pfd_confirm(c->u.pfd.s);
3751 if (c && c->closes) {
3753 * We have a pending close on this channel,
3754 * which we decided on before the server acked
3755 * the channel open. So now we know the
3756 * remoteid, we can close it again.
3758 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3759 PKT_INT, c->remoteid, PKT_END);
3762 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3763 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3764 struct ssh_channel *c;
3766 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3767 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3768 logevent("Forwarded connection refused by server");
3769 pfd_close(c->u.pfd.s);
3770 del234(ssh->channels, c);
3774 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3775 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3776 /* Remote side closes a channel. */
3777 unsigned i = ssh_pkt_getuint32(ssh);
3778 struct ssh_channel *c;
3779 c = find234(ssh->channels, &i, ssh_channelfind);
3780 if (c && ((int)c->remoteid) != -1) {
3783 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3785 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3786 logevent("Forwarded X11 connection terminated");
3787 assert(c->u.x11.s != NULL);
3788 x11_close(c->u.x11.s);
3791 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3792 logevent("Forwarded port closed");
3793 assert(c->u.pfd.s != NULL);
3794 pfd_close(c->u.pfd.s);
3798 c->closes |= (closetype << 2); /* seen this message */
3799 if (!(c->closes & closetype)) {
3800 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3802 c->closes |= closetype; /* sent it too */
3805 if (c->closes == 15) {
3806 del234(ssh->channels, c);
3810 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3811 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3812 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3816 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3817 /* Data sent down one of our channels. */
3818 int i = ssh_pkt_getuint32(ssh);
3821 struct ssh_channel *c;
3823 ssh_pkt_getstring(ssh, &p, &len);
3825 c = find234(ssh->channels, &i, ssh_channelfind);
3830 bufsize = x11_send(c->u.x11.s, p, len);
3833 bufsize = pfd_send(c->u.pfd.s, p, len);
3836 /* Data for an agent message. Buffer it. */
3838 if (c->u.a.lensofar < 4) {
3839 int l = min(4 - c->u.a.lensofar, len);
3840 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3844 c->u.a.lensofar += l;
3846 if (c->u.a.lensofar == 4) {
3848 4 + GET_32BIT(c->u.a.msglen);
3849 c->u.a.message = snewn(c->u.a.totallen,
3851 memcpy(c->u.a.message, c->u.a.msglen, 4);
3853 if (c->u.a.lensofar >= 4 && len > 0) {
3855 min(c->u.a.totallen - c->u.a.lensofar,
3857 memcpy(c->u.a.message + c->u.a.lensofar, p,
3861 c->u.a.lensofar += l;
3863 if (c->u.a.lensofar == c->u.a.totallen) {
3866 if (agent_query(c->u.a.message,
3869 ssh_agentf_callback, c))
3870 ssh_agentf_callback(c, reply, replylen);
3871 sfree(c->u.a.message);
3872 c->u.a.lensofar = 0;
3875 bufsize = 0; /* agent channels never back up */
3878 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3879 c->v.v1.throttling = 1;
3880 ssh1_throttle(ssh, +1);
3883 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3884 /* may be from EXEC_SHELL on some servers */
3885 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3886 /* may be from EXEC_SHELL on some servers
3887 * if no pty is available or in other odd cases. Ignore */
3888 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3890 ssh->exitcode = ssh_pkt_getuint32(ssh);
3891 sprintf(buf, "Server sent command exit status %d",
3894 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3896 * In case `helpful' firewalls or proxies tack
3897 * extra human-readable text on the end of the
3898 * session which we might mistake for another
3899 * encrypted packet, we close the session once
3900 * we've sent EXIT_CONFIRMATION.
3902 ssh_closing((Plug)ssh, NULL, 0, 0);
3905 bombout(("Strange packet received: type %d", ssh->pktin.type));
3910 int len = min(inlen, 512);
3911 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3912 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3923 * Utility routine for decoding comma-separated strings in KEXINIT.
3925 static int in_commasep_string(char *needle, char *haystack, int haylen)
3928 if (!needle || !haystack) /* protect against null pointers */
3930 needlen = strlen(needle);
3933 * Is it at the start of the string?
3935 if (haylen >= needlen && /* haystack is long enough */
3936 !memcmp(needle, haystack, needlen) && /* initial match */
3937 (haylen == needlen || haystack[needlen] == ',')
3938 /* either , or EOS follows */
3942 * If not, search for the next comma and resume after that.
3943 * If no comma found, terminate.
3945 while (haylen > 0 && *haystack != ',')
3946 haylen--, haystack++;
3949 haylen--, haystack++; /* skip over comma itself */
3954 * SSH2 key creation method.
3956 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3957 unsigned char *sessid, char chr,
3958 unsigned char *keyspace)
3961 /* First 20 bytes. */
3963 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3965 SHA_Bytes(&s, H, 20);
3966 SHA_Bytes(&s, &chr, 1);
3967 SHA_Bytes(&s, sessid, 20);
3968 SHA_Final(&s, keyspace);
3969 /* Next 20 bytes. */
3971 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3973 SHA_Bytes(&s, H, 20);
3974 SHA_Bytes(&s, keyspace, 20);
3975 SHA_Final(&s, keyspace + 20);
3979 * Handle the SSH2 transport layer.
3981 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3983 struct do_ssh2_transport_state {
3984 int nbits, pbits, warn;
3985 Bignum p, g, e, f, K;
3986 int kex_init_value, kex_reply_value;
3987 const struct ssh_mac **maclist;
3989 const struct ssh2_cipher *cscipher_tobe;
3990 const struct ssh2_cipher *sccipher_tobe;
3991 const struct ssh_mac *csmac_tobe;
3992 const struct ssh_mac *scmac_tobe;
3993 const struct ssh_compress *cscomp_tobe;
3994 const struct ssh_compress *sccomp_tobe;
3995 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3996 int hostkeylen, siglen;
3997 void *hkey; /* actual host key */
3998 unsigned char exchange_hash[20];
3999 int n_preferred_ciphers;
4000 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4001 const struct ssh_compress *preferred_comp;
4004 crState(do_ssh2_transport_state);
4006 crBegin(ssh->do_ssh2_transport_crstate);
4008 s->cscipher_tobe = s->sccipher_tobe = NULL;
4009 s->csmac_tobe = s->scmac_tobe = NULL;
4010 s->cscomp_tobe = s->sccomp_tobe = NULL;
4018 * Set up the preferred ciphers. (NULL => warn below here)
4020 s->n_preferred_ciphers = 0;
4021 for (i = 0; i < CIPHER_MAX; i++) {
4022 switch (ssh->cfg.ssh_cipherlist[i]) {
4023 case CIPHER_BLOWFISH:
4024 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4027 if (ssh->cfg.ssh2_des_cbc) {
4028 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4032 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4035 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4038 /* Flag for later. Don't bother if it's the last in
4040 if (i < CIPHER_MAX - 1) {
4041 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4049 * Set up preferred compression.
4051 if (ssh->cfg.compression)
4052 s->preferred_comp = &ssh_zlib;
4054 s->preferred_comp = &ssh_comp_none;
4057 * Be prepared to work around the buggy MAC problem.
4059 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4060 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4062 s->maclist = macs, s->nmacs = lenof(macs);
4066 int i, j, cipherstr_started;
4069 * Construct and send our key exchange packet.
4071 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4072 for (i = 0; i < 16; i++)
4073 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4074 /* List key exchange algorithms. */
4075 ssh2_pkt_addstring_start(ssh);
4076 for (i = 0; i < lenof(kex_algs); i++) {
4077 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4078 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4080 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4081 if (i < lenof(kex_algs) - 1)
4082 ssh2_pkt_addstring_str(ssh, ",");
4084 /* List server host key algorithms. */
4085 ssh2_pkt_addstring_start(ssh);
4086 for (i = 0; i < lenof(hostkey_algs); i++) {
4087 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4088 if (i < lenof(hostkey_algs) - 1)
4089 ssh2_pkt_addstring_str(ssh, ",");
4091 /* List client->server encryption algorithms. */
4092 ssh2_pkt_addstring_start(ssh);
4093 cipherstr_started = 0;
4094 for (i = 0; i < s->n_preferred_ciphers; i++) {
4095 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4096 if (!c) continue; /* warning flag */
4097 for (j = 0; j < c->nciphers; j++) {
4098 if (cipherstr_started)
4099 ssh2_pkt_addstring_str(ssh, ",");
4100 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4101 cipherstr_started = 1;
4104 /* List server->client encryption algorithms. */
4105 ssh2_pkt_addstring_start(ssh);
4106 cipherstr_started = 0;
4107 for (i = 0; i < s->n_preferred_ciphers; i++) {
4108 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4109 if (!c) continue; /* warning flag */
4110 for (j = 0; j < c->nciphers; j++) {
4111 if (cipherstr_started)
4112 ssh2_pkt_addstring_str(ssh, ",");
4113 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4114 cipherstr_started = 1;
4117 /* List client->server MAC algorithms. */
4118 ssh2_pkt_addstring_start(ssh);
4119 for (i = 0; i < s->nmacs; i++) {
4120 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4121 if (i < s->nmacs - 1)
4122 ssh2_pkt_addstring_str(ssh, ",");
4124 /* List server->client MAC algorithms. */
4125 ssh2_pkt_addstring_start(ssh);
4126 for (i = 0; i < s->nmacs; i++) {
4127 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4128 if (i < s->nmacs - 1)
4129 ssh2_pkt_addstring_str(ssh, ",");
4131 /* List client->server compression algorithms. */
4132 ssh2_pkt_addstring_start(ssh);
4133 for (i = 0; i < lenof(compressions) + 1; i++) {
4134 const struct ssh_compress *c =
4135 i == 0 ? s->preferred_comp : compressions[i - 1];
4136 ssh2_pkt_addstring_str(ssh, c->name);
4137 if (i < lenof(compressions))
4138 ssh2_pkt_addstring_str(ssh, ",");
4140 /* List server->client compression algorithms. */
4141 ssh2_pkt_addstring_start(ssh);
4142 for (i = 0; i < lenof(compressions) + 1; i++) {
4143 const struct ssh_compress *c =
4144 i == 0 ? s->preferred_comp : compressions[i - 1];
4145 ssh2_pkt_addstring_str(ssh, c->name);
4146 if (i < lenof(compressions))
4147 ssh2_pkt_addstring_str(ssh, ",");
4149 /* List client->server languages. Empty list. */
4150 ssh2_pkt_addstring_start(ssh);
4151 /* List server->client languages. Empty list. */
4152 ssh2_pkt_addstring_start(ssh);
4153 /* First KEX packet does _not_ follow, because we're not that brave. */
4154 ssh2_pkt_addbool(ssh, FALSE);
4156 ssh2_pkt_adduint32(ssh, 0);
4159 ssh->exhash = ssh->exhashbase;
4160 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4166 if (ssh->pktin.length > 5)
4167 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4170 * Now examine the other side's KEXINIT to see what we're up
4177 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4178 bombout(("expected key exchange packet from server"));
4182 ssh->hostkey = NULL;
4183 s->cscipher_tobe = NULL;
4184 s->sccipher_tobe = NULL;
4185 s->csmac_tobe = NULL;
4186 s->scmac_tobe = NULL;
4187 s->cscomp_tobe = NULL;
4188 s->sccomp_tobe = NULL;
4189 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4190 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4191 for (i = 0; i < lenof(kex_algs); i++) {
4192 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4193 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4195 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4196 ssh->kex = kex_algs[i];
4200 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4201 for (i = 0; i < lenof(hostkey_algs); i++) {
4202 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4203 ssh->hostkey = hostkey_algs[i];
4207 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4209 for (i = 0; i < s->n_preferred_ciphers; i++) {
4210 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4214 for (j = 0; j < c->nciphers; j++) {
4215 if (in_commasep_string(c->list[j]->name, str, len)) {
4216 s->cscipher_tobe = c->list[j];
4221 if (s->cscipher_tobe) {
4223 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4227 if (!s->cscipher_tobe) {
4228 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4229 str ? str : "(null)"));
4233 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4235 for (i = 0; i < s->n_preferred_ciphers; i++) {
4236 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4240 for (j = 0; j < c->nciphers; j++) {
4241 if (in_commasep_string(c->list[j]->name, str, len)) {
4242 s->sccipher_tobe = c->list[j];
4247 if (s->sccipher_tobe) {
4249 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4253 if (!s->sccipher_tobe) {
4254 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4255 str ? str : "(null)"));
4259 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
4260 for (i = 0; i < s->nmacs; i++) {
4261 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4262 s->csmac_tobe = s->maclist[i];
4266 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
4267 for (i = 0; i < s->nmacs; i++) {
4268 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4269 s->scmac_tobe = s->maclist[i];
4273 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
4274 for (i = 0; i < lenof(compressions) + 1; i++) {
4275 const struct ssh_compress *c =
4276 i == 0 ? s->preferred_comp : compressions[i - 1];
4277 if (in_commasep_string(c->name, str, len)) {
4282 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
4283 for (i = 0; i < lenof(compressions) + 1; i++) {
4284 const struct ssh_compress *c =
4285 i == 0 ? s->preferred_comp : compressions[i - 1];
4286 if (in_commasep_string(c->name, str, len)) {
4294 * Work out the number of bits of key we will need from the key
4295 * exchange. We start with the maximum key length of either
4301 csbits = s->cscipher_tobe->keylen;
4302 scbits = s->sccipher_tobe->keylen;
4303 s->nbits = (csbits > scbits ? csbits : scbits);
4305 /* The keys only have 160-bit entropy, since they're based on
4306 * a SHA-1 hash. So cap the key size at 160 bits. */
4311 * If we're doing Diffie-Hellman group exchange, start by
4312 * requesting a group.
4314 if (ssh->kex == &ssh_diffiehellman_gex) {
4315 logevent("Doing Diffie-Hellman group exchange");
4316 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4318 * Work out how big a DH group we will need to allow that
4321 s->pbits = 512 << ((s->nbits - 1) / 64);
4322 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4323 ssh2_pkt_adduint32(ssh, s->pbits);
4327 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4328 bombout(("expected key exchange group packet from server"));
4331 s->p = ssh2_pkt_getmp(ssh);
4332 s->g = ssh2_pkt_getmp(ssh);
4333 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4334 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4335 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4337 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4338 ssh->kex_ctx = dh_setup_group1();
4339 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4340 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4343 logevent("Doing Diffie-Hellman key exchange");
4345 * Now generate and send e for Diffie-Hellman.
4347 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4348 ssh2_pkt_init(ssh, s->kex_init_value);
4349 ssh2_pkt_addmp(ssh, s->e);
4353 if (ssh->pktin.type != s->kex_reply_value) {
4354 bombout(("expected key exchange reply packet from server"));
4357 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4358 s->f = ssh2_pkt_getmp(ssh);
4359 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4361 s->K = dh_find_K(ssh->kex_ctx, s->f);
4363 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4364 if (ssh->kex == &ssh_diffiehellman_gex) {
4365 sha_uint32(&ssh->exhash, s->pbits);
4366 sha_mpint(&ssh->exhash, s->p);
4367 sha_mpint(&ssh->exhash, s->g);
4369 sha_mpint(&ssh->exhash, s->e);
4370 sha_mpint(&ssh->exhash, s->f);
4371 sha_mpint(&ssh->exhash, s->K);
4372 SHA_Final(&ssh->exhash, s->exchange_hash);
4374 dh_cleanup(ssh->kex_ctx);
4375 ssh->kex_ctx = NULL;
4378 debug(("Exchange hash is:\n"));
4379 dmemdump(s->exchange_hash, 20);
4382 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4384 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4385 (char *)s->exchange_hash, 20)) {
4386 bombout(("Server's host key did not match the signature supplied"));
4391 * Authenticate remote host: verify host key. (We've already
4392 * checked the signature of the exchange hash.)
4394 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4395 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4396 verify_ssh_host_key(ssh->frontend,
4397 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4398 s->keystr, s->fingerprint);
4399 if (s->first_kex) { /* don't bother logging this in rekeys */
4400 logevent("Host key fingerprint is:");
4401 logevent(s->fingerprint);
4403 sfree(s->fingerprint);
4405 ssh->hostkey->freekey(s->hkey);
4408 * Send SSH2_MSG_NEWKEYS.
4410 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4414 * Expect SSH2_MSG_NEWKEYS from server.
4417 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4418 bombout(("expected new-keys packet from server"));
4423 * Create and initialise session keys.
4425 if (ssh->cs_cipher_ctx)
4426 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4427 ssh->cscipher = s->cscipher_tobe;
4428 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4430 if (ssh->sc_cipher_ctx)
4431 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4432 ssh->sccipher = s->sccipher_tobe;
4433 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4435 if (ssh->cs_mac_ctx)
4436 ssh->csmac->free_context(ssh->cs_mac_ctx);
4437 ssh->csmac = s->csmac_tobe;
4438 ssh->cs_mac_ctx = ssh->csmac->make_context();
4440 if (ssh->sc_mac_ctx)
4441 ssh->scmac->free_context(ssh->sc_mac_ctx);
4442 ssh->scmac = s->scmac_tobe;
4443 ssh->sc_mac_ctx = ssh->scmac->make_context();
4445 if (ssh->cs_comp_ctx)
4446 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4447 ssh->cscomp = s->cscomp_tobe;
4448 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4450 if (ssh->sc_comp_ctx)
4451 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4452 ssh->sccomp = s->sccomp_tobe;
4453 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4456 * Set IVs after keys. Here we use the exchange hash from the
4457 * _first_ key exchange.
4460 unsigned char keyspace[40];
4462 memcpy(ssh->v2_session_id, s->exchange_hash,
4463 sizeof(s->exchange_hash));
4464 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4465 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4466 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4467 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4468 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4469 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4470 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4471 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4472 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4473 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4474 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4475 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4477 logeventf(ssh, "Initialised %.200s client->server encryption",
4478 ssh->cscipher->text_name);
4479 logeventf(ssh, "Initialised %.200s server->client encryption",
4480 ssh->sccipher->text_name);
4481 if (ssh->cscomp->text_name)
4482 logeventf(ssh, "Initialised %s compression",
4483 ssh->cscomp->text_name);
4484 if (ssh->sccomp->text_name)
4485 logeventf(ssh, "Initialised %s decompression",
4486 ssh->sccomp->text_name);
4489 if (ssh->kex == &ssh_diffiehellman_gex) {
4495 * If this is the first key exchange phase, we must pass the
4496 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4497 * wants to see it but because it will need time to initialise
4498 * itself before it sees an actual packet. In subsequent key
4499 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4500 * it would only confuse the layer above.
4502 if (!s->first_kex) {
4508 * Now we're encrypting. Begin returning 1 to the protocol main
4509 * function so that other things can run on top of the
4510 * transport. If we ever see a KEXINIT, we must go back to the
4513 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4516 logevent("Server initiated key re-exchange");
4517 goto begin_key_exchange;
4523 * Add data to an SSH2 channel output buffer.
4525 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4528 bufchain_add(&c->v.v2.outbuffer, buf, len);
4532 * Attempt to send data on an SSH2 channel.
4534 static int ssh2_try_send(struct ssh_channel *c)
4538 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4541 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4542 if ((unsigned)len > c->v.v2.remwindow)
4543 len = c->v.v2.remwindow;
4544 if ((unsigned)len > c->v.v2.remmaxpkt)
4545 len = c->v.v2.remmaxpkt;
4546 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4547 ssh2_pkt_adduint32(ssh, c->remoteid);
4548 ssh2_pkt_addstring_start(ssh);
4549 ssh2_pkt_addstring_data(ssh, data, len);
4551 bufchain_consume(&c->v.v2.outbuffer, len);
4552 c->v.v2.remwindow -= len;
4556 * After having sent as much data as we can, return the amount
4559 return bufchain_size(&c->v.v2.outbuffer);
4563 * Potentially enlarge the window on an SSH2 channel.
4565 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4570 * Never send WINDOW_ADJUST for a channel that the remote side
4571 * already thinks it's closed; there's no point, since it won't
4572 * be sending any more data anyway.
4577 if (newwin > c->v.v2.locwindow) {
4578 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4579 ssh2_pkt_adduint32(ssh, c->remoteid);
4580 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4582 c->v.v2.locwindow = newwin;
4587 * Handle the SSH2 userauth and connection layers.
4589 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4591 struct do_ssh2_authconn_state {
4593 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4595 AUTH_KEYBOARD_INTERACTIVE
4599 AUTH_TYPE_PUBLICKEY,
4600 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4601 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4603 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4604 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4606 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4607 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4608 int kbd_inter_running;
4610 int num_prompts, curr_prompt, echo;
4615 void *publickey_blob;
4616 int publickey_bloblen;
4617 unsigned char request[5], *response, *p;
4621 char *pkblob, *alg, *commentp;
4622 int pklen, alglen, commentlen;
4623 int siglen, retlen, len;
4624 char *q, *agentreq, *ret;
4627 crState(do_ssh2_authconn_state);
4629 crBegin(ssh->do_ssh2_authconn_crstate);
4632 * Request userauth protocol, and await a response to it.
4634 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4635 ssh2_pkt_addstring(ssh, "ssh-userauth");
4637 crWaitUntilV(ispkt);
4638 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4639 bombout(("Server refused user authentication protocol"));
4644 * We repeat this whole loop, including the username prompt,
4645 * until we manage a successful authentication. If the user
4646 * types the wrong _password_, they can be sent back to the
4647 * beginning to try another username, if this is configured on.
4648 * (If they specify a username in the config, they are never
4649 * asked, even if they do give a wrong password.)
4651 * I think this best serves the needs of
4653 * - the people who have no configuration, no keys, and just
4654 * want to try repeated (username,password) pairs until they
4655 * type both correctly
4657 * - people who have keys and configuration but occasionally
4658 * need to fall back to passwords
4660 * - people with a key held in Pageant, who might not have
4661 * logged in to a particular machine before; so they want to
4662 * type a username, and then _either_ their key will be
4663 * accepted, _or_ they will type a password. If they mistype
4664 * the username they will want to be able to get back and
4667 s->username[0] = '\0';
4668 s->got_username = FALSE;
4673 if (s->got_username && !ssh->cfg.change_username) {
4675 * We got a username last time round this loop, and
4676 * with change_username turned off we don't try to get
4679 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4680 if (ssh_get_line && !ssh_getline_pw_only) {
4681 if (!ssh_get_line("login as: ",
4682 s->username, sizeof(s->username), FALSE)) {
4684 * get_line failed to get a username.
4687 logevent("No username provided. Abandoning session.");
4688 ssh_closing((Plug)ssh, NULL, 0, 0);
4692 int ret; /* need not be saved across crReturn */
4693 c_write_str(ssh, "login as: ");
4695 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4697 crWaitUntilV(!ispkt);
4698 ret = process_userpass_input(ssh, in, inlen);
4702 c_write_str(ssh, "\r\n");
4704 s->username[strcspn(s->username, "\n\r")] = '\0';
4707 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4708 s->username[sizeof(s->username)-1] = '\0';
4709 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4710 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4711 c_write_str(ssh, stuff);
4715 s->got_username = TRUE;
4718 * Send an authentication request using method "none": (a)
4719 * just in case it succeeds, and (b) so that we know what
4720 * authentication methods we can usefully try next.
4722 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4724 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4725 ssh2_pkt_addstring(ssh, s->username);
4726 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4727 ssh2_pkt_addstring(ssh, "none"); /* method */
4729 s->type = AUTH_TYPE_NONE;
4731 s->we_are_in = FALSE;
4733 s->tried_pubkey_config = FALSE;
4734 s->tried_agent = FALSE;
4735 s->tried_keyb_inter = FALSE;
4736 s->kbd_inter_running = FALSE;
4737 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4738 if (!filename_is_null(ssh->cfg.keyfile)) {
4740 logeventf(ssh, "Reading private key file \"%.150s\"",
4741 filename_to_str(&ssh->cfg.keyfile));
4742 keytype = key_type(&ssh->cfg.keyfile);
4743 if (keytype == SSH_KEYTYPE_SSH2) {
4745 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4746 &s->publickey_bloblen, NULL);
4749 logeventf(ssh, "Unable to use this key file (%s)",
4750 key_type_to_str(keytype));
4751 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4753 filename_to_str(&ssh->cfg.keyfile),
4754 key_type_to_str(keytype));
4755 c_write_str(ssh, msgbuf);
4757 s->publickey_blob = NULL;
4760 s->publickey_blob = NULL;
4764 * Wait for the result of the last authentication request.
4767 crWaitUntilV(ispkt);
4768 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4772 * Don't show the banner if we're operating in
4773 * non-verbose non-interactive mode. (It's probably
4774 * a script, which means nobody will read the
4775 * banner _anyway_, and moreover the printing of
4776 * the banner will screw up processing on the
4777 * output of (say) plink.)
4779 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4780 ssh_pkt_getstring(ssh, &banner, &size);
4782 c_write_untrusted(ssh, banner, size);
4784 crWaitUntilV(ispkt);
4786 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4787 logevent("Access granted");
4788 s->we_are_in = TRUE;
4792 if (s->kbd_inter_running &&
4793 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4795 * This is either a further set-of-prompts packet
4796 * in keyboard-interactive authentication, or it's
4797 * the same one and we came back here with `gotit'
4798 * set. In the former case, we must reset the
4799 * curr_prompt variable.
4803 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4804 bombout(("Strange packet received during authentication: type %d",
4812 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4813 * we can look at the string in it and know what we can
4814 * helpfully try next.
4816 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4819 ssh_pkt_getstring(ssh, &methods, &methlen);
4820 s->kbd_inter_running = FALSE;
4821 if (!ssh2_pkt_getbool(ssh)) {
4823 * We have received an unequivocal Access
4824 * Denied. This can translate to a variety of
4827 * - if we'd just tried "none" authentication,
4828 * it's not worth printing anything at all
4830 * - if we'd just tried a public key _offer_,
4831 * the message should be "Server refused our
4832 * key" (or no message at all if the key
4833 * came from Pageant)
4835 * - if we'd just tried anything else, the
4836 * message really should be "Access denied".
4838 * Additionally, if we'd just tried password
4839 * authentication, we should break out of this
4840 * whole loop so as to go back to the username
4843 if (s->type == AUTH_TYPE_NONE) {
4845 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4846 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4847 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4848 c_write_str(ssh, "Server refused our key\r\n");
4849 logevent("Server refused public key");
4850 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4851 /* server declined keyboard-interactive; ignore */
4853 c_write_str(ssh, "Access denied\r\n");
4854 logevent("Access denied");
4855 if (s->type == AUTH_TYPE_PASSWORD) {
4856 s->we_are_in = FALSE;
4861 c_write_str(ssh, "Further authentication required\r\n");
4862 logevent("Further authentication required");
4866 in_commasep_string("publickey", methods, methlen);
4868 in_commasep_string("password", methods, methlen);
4869 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4870 in_commasep_string("keyboard-interactive", methods, methlen);
4874 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4878 * Most password/passphrase prompts will be
4879 * non-echoing, so we set this to 0 by default.
4880 * Exception is that some keyboard-interactive prompts
4881 * can be echoing, in which case we'll set this to 1.
4885 if (!s->method && s->can_pubkey &&
4886 agent_exists() && !s->tried_agent) {
4888 * Attempt public-key authentication using Pageant.
4893 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4894 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4896 s->tried_agent = TRUE;
4898 logevent("Pageant is running. Requesting keys.");
4900 /* Request the keys held by the agent. */
4901 PUT_32BIT(s->request, 1);
4902 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4903 if (!agent_query(s->request, 5, &r, &s->responselen,
4904 ssh_agent_callback, ssh)) {
4908 bombout(("Unexpected data from server while"
4909 " waiting for agent response"));
4912 } while (ispkt || inlen > 0);
4913 r = ssh->agent_response;
4914 s->responselen = ssh->agent_response_len;
4916 s->response = (unsigned char *) r;
4917 if (s->response && s->responselen >= 5 &&
4918 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4919 s->p = s->response + 5;
4920 s->nkeys = GET_32BIT(s->p);
4924 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4927 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4932 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4935 s->pklen = GET_32BIT(s->p);
4937 if (s->publickey_blob &&
4938 s->pklen == s->publickey_bloblen &&
4939 !memcmp(s->p, s->publickey_blob,
4940 s->publickey_bloblen)) {
4941 logevent("This key matches configured key file");
4942 s->tried_pubkey_config = 1;
4944 s->pkblob = (char *)s->p;
4946 s->alglen = GET_32BIT(s->pkblob);
4947 s->alg = s->pkblob + 4;
4948 s->commentlen = GET_32BIT(s->p);
4950 s->commentp = (char *)s->p;
4951 s->p += s->commentlen;
4952 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4953 ssh2_pkt_addstring(ssh, s->username);
4954 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4955 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4956 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4957 ssh2_pkt_addstring_start(ssh);
4958 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4959 ssh2_pkt_addstring_start(ssh);
4960 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4963 crWaitUntilV(ispkt);
4964 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4965 logevent("Key refused");
4969 if (flags & FLAG_VERBOSE) {
4970 c_write_str(ssh, "Authenticating with "
4972 c_write(ssh, s->commentp, s->commentlen);
4973 c_write_str(ssh, "\" from agent\r\n");
4977 * Server is willing to accept the key.
4978 * Construct a SIGN_REQUEST.
4980 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4981 ssh2_pkt_addstring(ssh, s->username);
4982 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4983 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4984 ssh2_pkt_addbool(ssh, TRUE);
4985 ssh2_pkt_addstring_start(ssh);
4986 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4987 ssh2_pkt_addstring_start(ssh);
4988 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4990 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4991 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4993 s->len = 1; /* message type */
4994 s->len += 4 + s->pklen; /* key blob */
4995 s->len += 4 + s->siglen; /* data to sign */
4996 s->len += 4; /* flags */
4997 s->agentreq = snewn(4 + s->len, char);
4998 PUT_32BIT(s->agentreq, s->len);
4999 s->q = s->agentreq + 4;
5000 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5001 PUT_32BIT(s->q, s->pklen);
5003 memcpy(s->q, s->pkblob, s->pklen);
5005 PUT_32BIT(s->q, s->siglen);
5007 /* Now the data to be signed... */
5008 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5009 PUT_32BIT(s->q, 20);
5012 memcpy(s->q, ssh->v2_session_id, 20);
5014 memcpy(s->q, ssh->pktout.data + 5,
5015 ssh->pktout.length - 5);
5016 s->q += ssh->pktout.length - 5;
5017 /* And finally the (zero) flags word. */
5019 if (!agent_query(s->agentreq, s->len + 4,
5021 ssh_agent_callback, ssh)) {
5025 bombout(("Unexpected data from server"
5026 " while waiting for agent"
5030 } while (ispkt || inlen > 0);
5031 vret = ssh->agent_response;
5032 s->retlen = ssh->agent_response_len;
5037 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5038 logevent("Sending Pageant's response");
5039 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5041 GET_32BIT(s->ret + 5));
5047 ("Pageant failed to answer challenge");
5058 if (!s->method && s->can_pubkey && s->publickey_blob
5059 && !s->tried_pubkey_config) {
5060 unsigned char *pub_blob;
5061 char *algorithm, *comment;
5064 s->tried_pubkey_config = TRUE;
5066 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5067 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5070 * Try the public key supplied in the configuration.
5072 * First, offer the public blob to see if the server is
5073 * willing to accept it.
5076 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
5081 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5082 ssh2_pkt_addstring(ssh, s->username);
5083 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5084 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5085 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5086 ssh2_pkt_addstring(ssh, algorithm);
5087 ssh2_pkt_addstring_start(ssh);
5088 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5091 logevent("Offered public key"); /* FIXME */
5093 crWaitUntilV(ispkt);
5094 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5096 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
5097 continue; /* key refused; give up on it */
5100 logevent("Offer of public key accepted");
5102 * Actually attempt a serious authentication using
5105 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
5106 sprintf(s->pwprompt,
5107 "Passphrase for key \"%.100s\": ",
5113 if (flags & FLAG_VERBOSE) {
5114 c_write_str(ssh, "Authenticating with public key \"");
5115 c_write_str(ssh, comment);
5116 c_write_str(ssh, "\"\r\n");
5118 s->method = AUTH_PUBLICKEY_FILE;
5122 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5123 s->method = AUTH_KEYBOARD_INTERACTIVE;
5124 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5125 s->tried_keyb_inter = TRUE;
5127 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5128 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5130 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5131 ssh2_pkt_addstring(ssh, s->username);
5132 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5133 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5134 ssh2_pkt_addstring(ssh, ""); /* lang */
5135 ssh2_pkt_addstring(ssh, "");
5138 crWaitUntilV(ispkt);
5139 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5140 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5142 logevent("Keyboard-interactive authentication refused");
5143 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5147 s->kbd_inter_running = TRUE;
5151 if (s->kbd_inter_running) {
5152 s->method = AUTH_KEYBOARD_INTERACTIVE;
5153 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5154 s->tried_keyb_inter = TRUE;
5156 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5157 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5159 if (s->curr_prompt == 0) {
5161 * We've got a fresh USERAUTH_INFO_REQUEST.
5162 * Display header data, and start going through
5165 char *name, *inst, *lang;
5166 int name_len, inst_len, lang_len;
5168 ssh_pkt_getstring(ssh, &name, &name_len);
5169 ssh_pkt_getstring(ssh, &inst, &inst_len);
5170 ssh_pkt_getstring(ssh, &lang, &lang_len);
5172 c_write_untrusted(ssh, name, name_len);
5173 c_write_str(ssh, "\r\n");
5176 c_write_untrusted(ssh, inst, inst_len);
5177 c_write_str(ssh, "\r\n");
5179 s->num_prompts = ssh_pkt_getuint32(ssh);
5183 * If there are prompts remaining in the packet,
5184 * display one and get a response.
5186 if (s->curr_prompt < s->num_prompts) {
5190 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
5191 if (prompt_len > 0) {
5192 static const char trunc[] = "<prompt truncated>: ";
5193 static const int prlen = sizeof(s->pwprompt) -
5195 if (prompt_len > prlen) {
5196 memcpy(s->pwprompt, prompt, prlen);
5197 strcpy(s->pwprompt + prlen, trunc);
5199 memcpy(s->pwprompt, prompt, prompt_len);
5200 s->pwprompt[prompt_len] = '\0';
5204 "<server failed to send prompt>: ");
5206 s->echo = ssh2_pkt_getbool(ssh);
5212 if (!s->method && s->can_passwd) {
5213 s->method = AUTH_PASSWORD;
5214 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5215 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5216 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5223 if (!ssh_get_line(s->pwprompt, s->password,
5224 sizeof(s->password), TRUE)) {
5226 * get_line failed to get a password (for
5227 * example because one was supplied on the
5228 * command line which has already failed to
5231 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5232 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5233 ssh2_pkt_addstring(ssh, "No more passwords available"
5235 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5237 logevent("Unable to authenticate");
5238 connection_fatal(ssh->frontend,
5239 "Unable to authenticate");
5240 ssh_closing((Plug)ssh, NULL, 0, 0);
5244 int ret; /* need not be saved across crReturn */
5245 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5248 setup_userpass_input(ssh, s->password,
5249 sizeof(s->password), s->echo);
5251 crWaitUntilV(!ispkt);
5252 ret = process_userpass_input(ssh, in, inlen);
5256 c_write_str(ssh, "\r\n");
5260 if (s->method == AUTH_PUBLICKEY_FILE) {
5262 * We have our passphrase. Now try the actual authentication.
5264 struct ssh2_userkey *key;
5265 const char *error = NULL;
5267 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5269 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5270 if (key == SSH2_WRONG_PASSPHRASE) {
5271 c_write_str(ssh, "Wrong passphrase\r\n");
5272 s->tried_pubkey_config = FALSE;
5274 c_write_str(ssh, "Unable to load private key (");
5275 c_write_str(ssh, error);
5276 c_write_str(ssh, ")\r\n");
5277 s->tried_pubkey_config = TRUE;
5279 /* Send a spurious AUTH_NONE to return to the top. */
5280 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5281 ssh2_pkt_addstring(ssh, s->username);
5282 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5283 ssh2_pkt_addstring(ssh, "none"); /* method */
5285 s->type = AUTH_TYPE_NONE;
5287 unsigned char *pkblob, *sigblob, *sigdata;
5288 int pkblob_len, sigblob_len, sigdata_len;
5292 * We have loaded the private key and the server
5293 * has announced that it's willing to accept it.
5294 * Hallelujah. Generate a signature and send it.
5296 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5297 ssh2_pkt_addstring(ssh, s->username);
5298 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5299 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5300 ssh2_pkt_addbool(ssh, TRUE);
5301 ssh2_pkt_addstring(ssh, key->alg->name);
5302 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5303 ssh2_pkt_addstring_start(ssh);
5304 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5307 * The data to be signed is:
5311 * followed by everything so far placed in the
5314 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5315 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5317 sigdata = snewn(sigdata_len, unsigned char);
5319 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5320 PUT_32BIT(sigdata+p, 20);
5323 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5324 memcpy(sigdata+p, ssh->pktout.data + 5,
5325 ssh->pktout.length - 5);
5326 p += ssh->pktout.length - 5;
5327 assert(p == sigdata_len);
5328 sigblob = key->alg->sign(key->data, (char *)sigdata,
5329 sigdata_len, &sigblob_len);
5330 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5331 sigblob, sigblob_len);
5337 s->type = AUTH_TYPE_PUBLICKEY;
5338 key->alg->freekey(key->data);
5340 } else if (s->method == AUTH_PASSWORD) {
5342 * We send the password packet lumped tightly together with
5343 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5344 * string long enough to make the total length of the two
5345 * packets constant. This should ensure that a passive
5346 * listener doing traffic analyis can't work out the length
5349 * For this to work, we need an assumption about the
5350 * maximum length of the password packet. I think 256 is
5351 * pretty conservative. Anyone using a password longer than
5352 * that probably doesn't have much to worry about from
5353 * people who find out how long their password is!
5355 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5356 ssh2_pkt_addstring(ssh, s->username);
5357 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5358 ssh2_pkt_addstring(ssh, "password");
5359 ssh2_pkt_addbool(ssh, FALSE);
5360 ssh2_pkt_addstring(ssh, s->password);
5361 memset(s->password, 0, sizeof(s->password));
5362 ssh2_pkt_defer(ssh);
5364 * We'll include a string that's an exact multiple of the
5365 * cipher block size. If the cipher is NULL for some
5366 * reason, we don't do this trick at all because we gain
5369 if (ssh->cscipher) {
5372 stringlen = (256 - ssh->deferred_len);
5373 stringlen += ssh->cscipher->blksize - 1;
5374 stringlen -= (stringlen % ssh->cscipher->blksize);
5377 * Temporarily disable actual compression,
5378 * so we can guarantee to get this string
5379 * exactly the length we want it. The
5380 * compression-disabling routine should
5381 * return an integer indicating how many
5382 * bytes we should adjust our string length
5386 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5388 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5389 ssh2_pkt_addstring_start(ssh);
5390 for (i = 0; i < stringlen; i++) {
5391 char c = (char) random_byte();
5392 ssh2_pkt_addstring_data(ssh, &c, 1);
5394 ssh2_pkt_defer(ssh);
5396 ssh_pkt_defersend(ssh);
5397 logevent("Sent password");
5398 s->type = AUTH_TYPE_PASSWORD;
5399 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5400 if (s->curr_prompt == 0) {
5401 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5402 ssh2_pkt_adduint32(ssh, s->num_prompts);
5404 if (s->need_pw) { /* only add pw if we just got one! */
5405 ssh2_pkt_addstring(ssh, s->password);
5406 memset(s->password, 0, sizeof(s->password));
5409 if (s->curr_prompt >= s->num_prompts) {
5413 * If there are prompts remaining, we set
5414 * `gotit' so that we won't attempt to get
5415 * another packet. Then we go back round the
5416 * loop and will end up retrieving another
5417 * prompt out of the existing packet. Funky or
5422 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5424 c_write_str(ssh, "No supported authentication methods"
5425 " left to try!\r\n");
5426 logevent("No supported authentications offered."
5428 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5429 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5430 ssh2_pkt_addstring(ssh, "No supported authentication"
5431 " methods available");
5432 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5434 ssh_closing((Plug)ssh, NULL, 0, 0);
5438 } while (!s->we_are_in);
5441 * Now we're authenticated for the connection protocol. The
5442 * connection protocol will automatically have started at this
5443 * point; there's no need to send SERVICE_REQUEST.
5447 * So now create a channel with a session in it.
5449 ssh->channels = newtree234(ssh_channelcmp);
5450 ssh->mainchan = snew(struct ssh_channel);
5451 ssh->mainchan->ssh = ssh;
5452 ssh->mainchan->localid = alloc_channel_id(ssh);
5453 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5454 ssh2_pkt_addstring(ssh, "session");
5455 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5456 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5457 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5458 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5460 crWaitUntilV(ispkt);
5461 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5462 bombout(("Server refused to open a session"));
5464 /* FIXME: error data comes back in FAILURE packet */
5466 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5467 bombout(("Server's channel confirmation cited wrong channel"));
5470 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5471 ssh->mainchan->type = CHAN_MAINSESSION;
5472 ssh->mainchan->closes = 0;
5473 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5474 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5475 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5476 add234(ssh->channels, ssh->mainchan);
5477 logevent("Opened channel for session");
5480 * Potentially enable X11 forwarding.
5482 if (ssh->cfg.x11_forward) {
5483 char proto[20], data[64];
5484 logevent("Requesting X11 forwarding");
5485 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5486 data, sizeof(data), ssh->cfg.x11_auth);
5487 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5488 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5489 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5490 ssh2_pkt_addstring(ssh, "x11-req");
5491 ssh2_pkt_addbool(ssh, 1); /* want reply */
5492 ssh2_pkt_addbool(ssh, 0); /* many connections */
5493 ssh2_pkt_addstring(ssh, proto);
5494 ssh2_pkt_addstring(ssh, data);
5495 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5499 crWaitUntilV(ispkt);
5500 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5501 unsigned i = ssh_pkt_getuint32(ssh);
5502 struct ssh_channel *c;
5503 c = find234(ssh->channels, &i, ssh_channelfind);
5505 continue; /* nonexistent channel */
5506 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5508 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5510 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5511 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5512 bombout(("Unexpected response to X11 forwarding request:"
5513 " packet type %d", ssh->pktin.type));
5516 logevent("X11 forwarding refused");
5518 logevent("X11 forwarding enabled");
5519 ssh->X11_fwd_enabled = TRUE;
5524 * Enable port forwardings.
5529 int sport,dport,sserv,dserv;
5530 char sports[256], dports[256], saddr[256], host[256];
5532 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5533 /* Add port forwardings. */
5534 ssh->portfwd_strptr = ssh->cfg.portfwd;
5535 while (*ssh->portfwd_strptr) {
5536 type = *ssh->portfwd_strptr++;
5539 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5540 if (*ssh->portfwd_strptr == ':') {
5542 * We've seen a colon in the middle of the
5543 * source port number. This means that
5544 * everything we've seen until now is the
5545 * source _address_, so we'll move it into
5546 * saddr and start sports from the beginning
5549 ssh->portfwd_strptr++;
5551 strcpy(saddr, sports);
5554 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5558 if (*ssh->portfwd_strptr == '\t')
5559 ssh->portfwd_strptr++;
5561 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5562 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5565 if (*ssh->portfwd_strptr == ':')
5566 ssh->portfwd_strptr++;
5568 while (*ssh->portfwd_strptr) {
5569 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5572 ssh->portfwd_strptr++;
5573 dport = atoi(dports);
5577 dport = net_service_lookup(dports);
5579 logeventf(ssh, "Service lookup failed for destination"
5580 " port \"%s\"", dports);
5584 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5586 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5588 sport = atoi(sports);
5592 sport = net_service_lookup(sports);
5594 logeventf(ssh, "Service lookup failed for source"
5595 " port \"%s\"", sports);
5598 if (sport && dport) {
5600 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5601 sport, ssh, &ssh->cfg);
5602 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5603 " forwarding to %s:%.*s%.*s%d%.*s",
5604 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5605 (int)(*saddr?1:0), ":",
5606 (int)(sserv ? strlen(sports) : 0), sports,
5607 sserv, "(", sport, sserv, ")",
5609 (int)(dserv ? strlen(dports) : 0), dports,
5610 dserv, "(", dport, dserv, ")");
5611 } else if (type == 'D') {
5612 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5613 sport, ssh, &ssh->cfg);
5614 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5615 " doing SOCKS dynamic forwarding",
5616 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5617 (int)(*saddr?1:0), ":",
5618 (int)(sserv ? strlen(sports) : 0), sports,
5619 sserv, "(", sport, sserv, ")");
5621 struct ssh_rportfwd *pf;
5622 pf = snew(struct ssh_rportfwd);
5623 strcpy(pf->dhost, host);
5626 if (add234(ssh->rportfwds, pf) != pf) {
5627 logeventf(ssh, "Duplicate remote port forwarding"
5628 " to %s:%d", host, dport);
5631 logeventf(ssh, "Requesting remote port "
5632 "%.*s%.*s%.*s%.*s%d%.*s"
5633 " forward to %s:%.*s%.*s%d%.*s",
5634 (int)(*saddr?strlen(saddr):0),
5636 (int)(*saddr?1:0), ":",
5637 (int)(sserv ? strlen(sports) : 0), sports,
5638 sserv, "(", sport, sserv, ")",
5640 (int)(dserv ? strlen(dports) : 0), dports,
5641 dserv, "(", dport, dserv, ")");
5642 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5643 ssh2_pkt_addstring(ssh, "tcpip-forward");
5644 ssh2_pkt_addbool(ssh, 1);/* want reply */
5646 ssh2_pkt_addstring(ssh, saddr);
5647 if (ssh->cfg.rport_acceptall)
5648 ssh2_pkt_addstring(ssh, "0.0.0.0");
5650 ssh2_pkt_addstring(ssh, "127.0.0.1");
5651 ssh2_pkt_adduint32(ssh, sport);
5655 crWaitUntilV(ispkt);
5656 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5657 unsigned i = ssh_pkt_getuint32(ssh);
5658 struct ssh_channel *c;
5659 c = find234(ssh->channels, &i, ssh_channelfind);
5661 continue;/* nonexistent channel */
5662 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5664 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5666 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5667 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5668 bombout(("Unexpected response to port "
5669 "forwarding request: packet type %d",
5673 logevent("Server refused this port forwarding");
5675 logevent("Remote port forwarding enabled");
5684 * Potentially enable agent forwarding.
5686 if (ssh->cfg.agentfwd && agent_exists()) {
5687 logevent("Requesting OpenSSH-style agent forwarding");
5688 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5689 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5690 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5691 ssh2_pkt_addbool(ssh, 1); /* want reply */
5695 crWaitUntilV(ispkt);
5696 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5697 unsigned i = ssh_pkt_getuint32(ssh);
5698 struct ssh_channel *c;
5699 c = find234(ssh->channels, &i, ssh_channelfind);
5701 continue; /* nonexistent channel */
5702 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5704 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5706 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5707 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5708 bombout(("Unexpected response to agent forwarding request:"
5709 " packet type %d", ssh->pktin.type));
5712 logevent("Agent forwarding refused");
5714 logevent("Agent forwarding enabled");
5715 ssh->agentfwd_enabled = TRUE;
5720 * Now allocate a pty for the session.
5722 if (!ssh->cfg.nopty) {
5723 /* Unpick the terminal-speed string. */
5724 /* XXX perhaps we should allow no speeds to be sent. */
5725 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5726 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5727 /* Build the pty request. */
5728 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5729 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5730 ssh2_pkt_addstring(ssh, "pty-req");
5731 ssh2_pkt_addbool(ssh, 1); /* want reply */
5732 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5733 ssh2_pkt_adduint32(ssh, ssh->term_width);
5734 ssh2_pkt_adduint32(ssh, ssh->term_height);
5735 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5736 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5737 ssh2_pkt_addstring_start(ssh);
5738 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
5739 ssh2_pkt_adduint32(ssh, ssh->ispeed);
5740 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
5741 ssh2_pkt_adduint32(ssh, ssh->ospeed);
5742 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
5744 ssh->state = SSH_STATE_INTERMED;
5747 crWaitUntilV(ispkt);
5748 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5749 unsigned i = ssh_pkt_getuint32(ssh);
5750 struct ssh_channel *c;
5751 c = find234(ssh->channels, &i, ssh_channelfind);
5753 continue; /* nonexistent channel */
5754 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5756 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5758 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5759 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5760 bombout(("Unexpected response to pty request:"
5761 " packet type %d", ssh->pktin.type));
5764 c_write_str(ssh, "Server refused to allocate pty\r\n");
5765 ssh->editing = ssh->echoing = 1;
5767 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5768 ssh->ospeed, ssh->ispeed);
5771 ssh->editing = ssh->echoing = 1;
5775 * Start a shell or a remote command. We may have to attempt
5776 * this twice if the config data has provided a second choice
5783 if (ssh->fallback_cmd) {
5784 subsys = ssh->cfg.ssh_subsys2;
5785 cmd = ssh->cfg.remote_cmd_ptr2;
5787 subsys = ssh->cfg.ssh_subsys;
5788 cmd = ssh->cfg.remote_cmd_ptr;
5791 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5792 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5794 ssh2_pkt_addstring(ssh, "subsystem");
5795 ssh2_pkt_addbool(ssh, 1); /* want reply */
5796 ssh2_pkt_addstring(ssh, cmd);
5798 ssh2_pkt_addstring(ssh, "exec");
5799 ssh2_pkt_addbool(ssh, 1); /* want reply */
5800 ssh2_pkt_addstring(ssh, cmd);
5802 ssh2_pkt_addstring(ssh, "shell");
5803 ssh2_pkt_addbool(ssh, 1); /* want reply */
5807 crWaitUntilV(ispkt);
5808 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5809 unsigned i = ssh_pkt_getuint32(ssh);
5810 struct ssh_channel *c;
5811 c = find234(ssh->channels, &i, ssh_channelfind);
5813 continue; /* nonexistent channel */
5814 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5816 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5817 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5818 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5819 bombout(("Unexpected response to shell/command request:"
5820 " packet type %d", ssh->pktin.type));
5824 * We failed to start the command. If this is the
5825 * fallback command, we really are finished; if it's
5826 * not, and if the fallback command exists, try falling
5827 * back to it before complaining.
5829 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5830 logevent("Primary command failed; attempting fallback");
5831 ssh->fallback_cmd = TRUE;
5834 bombout(("Server refused to start a shell/command"));
5837 logevent("Started a shell/command");
5842 ssh->state = SSH_STATE_SESSION;
5843 if (ssh->size_needed)
5844 ssh_size(ssh, ssh->term_width, ssh->term_height);
5845 if (ssh->eof_needed)
5846 ssh_special(ssh, TS_EOF);
5852 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5856 s->try_send = FALSE;
5858 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5859 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5862 unsigned i = ssh_pkt_getuint32(ssh);
5863 struct ssh_channel *c;
5864 c = find234(ssh->channels, &i, ssh_channelfind);
5866 continue; /* nonexistent channel */
5867 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5868 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5869 continue; /* extended but not stderr */
5870 ssh_pkt_getstring(ssh, &data, &length);
5873 c->v.v2.locwindow -= length;
5875 case CHAN_MAINSESSION:
5877 from_backend(ssh->frontend, ssh->pktin.type ==
5878 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5882 bufsize = x11_send(c->u.x11.s, data, length);
5885 bufsize = pfd_send(c->u.pfd.s, data, length);
5888 while (length > 0) {
5889 if (c->u.a.lensofar < 4) {
5890 int l = min(4 - c->u.a.lensofar, length);
5891 memcpy(c->u.a.msglen + c->u.a.lensofar,
5895 c->u.a.lensofar += l;
5897 if (c->u.a.lensofar == 4) {
5899 4 + GET_32BIT(c->u.a.msglen);
5900 c->u.a.message = snewn(c->u.a.totallen,
5902 memcpy(c->u.a.message, c->u.a.msglen, 4);
5904 if (c->u.a.lensofar >= 4 && length > 0) {
5906 min(c->u.a.totallen - c->u.a.lensofar,
5908 memcpy(c->u.a.message + c->u.a.lensofar,
5912 c->u.a.lensofar += l;
5914 if (c->u.a.lensofar == c->u.a.totallen) {
5917 if (agent_query(c->u.a.message,
5920 ssh_agentf_callback, c))
5921 ssh_agentf_callback(c, reply, replylen);
5922 sfree(c->u.a.message);
5923 c->u.a.lensofar = 0;
5930 * If we are not buffering too much data,
5931 * enlarge the window again at the remote side.
5933 if (bufsize < OUR_V2_WINSIZE)
5934 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5936 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5937 unsigned i = ssh_pkt_getuint32(ssh);
5938 struct ssh_channel *c;
5940 c = find234(ssh->channels, &i, ssh_channelfind);
5942 continue; /* nonexistent channel */
5944 if (c->type == CHAN_X11) {
5946 * Remote EOF on an X11 channel means we should
5947 * wrap up and close the channel ourselves.
5949 x11_close(c->u.x11.s);
5951 } else if (c->type == CHAN_AGENT) {
5953 } else if (c->type == CHAN_SOCKDATA) {
5954 pfd_close(c->u.pfd.s);
5957 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5958 unsigned i = ssh_pkt_getuint32(ssh);
5959 struct ssh_channel *c;
5961 c = find234(ssh->channels, &i, ssh_channelfind);
5962 if (!c || ((int)c->remoteid) == -1) {
5963 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5964 c ? "half-open" : "nonexistent", i));
5967 /* Do pre-close processing on the channel. */
5969 case CHAN_MAINSESSION:
5970 break; /* nothing to see here, move along */
5972 if (c->u.x11.s != NULL)
5973 x11_close(c->u.x11.s);
5980 if (c->u.pfd.s != NULL)
5981 pfd_close(c->u.pfd.s);
5985 if (c->closes == 0) {
5986 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5987 ssh2_pkt_adduint32(ssh, c->remoteid);
5990 del234(ssh->channels, c);
5991 bufchain_clear(&c->v.v2.outbuffer);
5995 * See if that was the last channel left open.
5997 if (count234(ssh->channels) == 0) {
5998 logevent("All channels closed. Disconnecting");
6001 * We used to send SSH_MSG_DISCONNECT here,
6002 * because I'd believed that _every_ conforming
6003 * SSH2 connection had to end with a disconnect
6004 * being sent by at least one side; apparently
6005 * I was wrong and it's perfectly OK to
6006 * unceremoniously slam the connection shut
6007 * when you're done, and indeed OpenSSH feels
6008 * this is more polite than sending a
6009 * DISCONNECT. So now we don't.
6011 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6012 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6013 ssh2_pkt_addstring(ssh, "All open channels closed");
6014 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6017 ssh_closing((Plug)ssh, NULL, 0, 0);
6020 continue; /* remote sends close; ignore (FIXME) */
6021 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6022 unsigned i = ssh_pkt_getuint32(ssh);
6023 struct ssh_channel *c;
6024 c = find234(ssh->channels, &i, ssh_channelfind);
6025 if (!c || c->closes)
6026 continue; /* nonexistent or closing channel */
6027 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6029 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6030 unsigned i = ssh_pkt_getuint32(ssh);
6031 struct ssh_channel *c;
6032 c = find234(ssh->channels, &i, ssh_channelfind);
6034 continue; /* nonexistent channel */
6035 if (c->type != CHAN_SOCKDATA_DORMANT)
6036 continue; /* dunno why they're confirming this */
6037 c->remoteid = ssh_pkt_getuint32(ssh);
6038 c->type = CHAN_SOCKDATA;
6039 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6040 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
6042 pfd_confirm(c->u.pfd.s);
6045 * We have a pending close on this channel,
6046 * which we decided on before the server acked
6047 * the channel open. So now we know the
6048 * remoteid, we can close it again.
6050 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6051 ssh2_pkt_adduint32(ssh, c->remoteid);
6054 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
6055 unsigned i = ssh_pkt_getuint32(ssh);
6056 struct ssh_channel *c;
6057 c = find234(ssh->channels, &i, ssh_channelfind);
6059 continue; /* nonexistent channel */
6060 if (c->type != CHAN_SOCKDATA_DORMANT)
6061 continue; /* dunno why they're failing this */
6063 logevent("Forwarded connection refused by server");
6065 pfd_close(c->u.pfd.s);
6067 del234(ssh->channels, c);
6069 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
6072 int typelen, want_reply;
6073 struct ssh_channel *c;
6075 localid = ssh_pkt_getuint32(ssh);
6076 ssh_pkt_getstring(ssh, &type, &typelen);
6077 want_reply = ssh2_pkt_getbool(ssh);
6080 * First, check that the channel exists. Otherwise,
6081 * we can instantly disconnect with a rude message.
6083 c = find234(ssh->channels, &localid, ssh_channelfind);
6086 sprintf(buf, "Received channel request for nonexistent"
6087 " channel %d", localid);
6089 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6090 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6091 ssh2_pkt_addstring(ssh, buf);
6092 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6094 connection_fatal(ssh->frontend, "%s", buf);
6095 ssh_closing((Plug)ssh, NULL, 0, 0);
6100 * Having got the channel number, we now look at
6101 * the request type string to see if it's something
6104 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
6105 c == ssh->mainchan) {
6106 /* We recognise "exit-status" on the primary channel. */
6108 ssh->exitcode = ssh_pkt_getuint32(ssh);
6109 sprintf(buf, "Server sent command exit status %d",
6113 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
6114 ssh2_pkt_adduint32(ssh, c->remoteid);
6119 * This is a channel request we don't know
6120 * about, so we now either ignore the request
6121 * or respond with CHANNEL_FAILURE, depending
6125 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
6126 ssh2_pkt_adduint32(ssh, c->remoteid);
6130 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
6132 int typelen, want_reply;
6134 ssh_pkt_getstring(ssh, &type, &typelen);
6135 want_reply = ssh2_pkt_getbool(ssh);
6138 * We currently don't support any global requests
6139 * at all, so we either ignore the request or
6140 * respond with REQUEST_FAILURE, depending on
6144 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6147 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6154 struct ssh_channel *c;
6155 unsigned remid, winsize, pktsize;
6156 ssh_pkt_getstring(ssh, &type, &typelen);
6157 c = snew(struct ssh_channel);
6160 remid = ssh_pkt_getuint32(ssh);
6161 winsize = ssh_pkt_getuint32(ssh);
6162 pktsize = ssh_pkt_getuint32(ssh);
6164 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6167 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6168 addrstr = snewn(peeraddrlen+1, char);
6169 memcpy(addrstr, peeraddr, peeraddrlen);
6170 addrstr[peeraddrlen] = '\0';
6171 peerport = ssh_pkt_getuint32(ssh);
6173 logeventf(ssh, "Received X11 connect request from %s:%d",
6176 if (!ssh->X11_fwd_enabled)
6177 error = "X11 forwarding is not enabled";
6178 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6179 ssh->x11auth, addrstr, peerport,
6180 &ssh->cfg) != NULL) {
6181 error = "Unable to open an X11 connection";
6183 logevent("Opening X11 forward connection succeeded");
6188 } else if (typelen == 15 &&
6189 !memcmp(type, "forwarded-tcpip", 15)) {
6190 struct ssh_rportfwd pf, *realpf;
6193 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6194 pf.sport = ssh_pkt_getuint32(ssh);
6195 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6196 peerport = ssh_pkt_getuint32(ssh);
6197 realpf = find234(ssh->rportfwds, &pf, NULL);
6198 logeventf(ssh, "Received remote port %d open request "
6199 "from %s:%d", pf.sport, peeraddr, peerport);
6200 if (realpf == NULL) {
6201 error = "Remote port is not recognised";
6203 const char *e = pfd_newconnect(&c->u.pfd.s,
6207 logeventf(ssh, "Attempting to forward remote port to "
6208 "%s:%d", realpf->dhost, realpf->dport);
6210 logeventf(ssh, "Port open failed: %s", e);
6211 error = "Port open failed";
6213 logevent("Forwarded port opened successfully");
6214 c->type = CHAN_SOCKDATA;
6217 } else if (typelen == 22 &&
6218 !memcmp(type, "auth-agent@openssh.com", 3)) {
6219 if (!ssh->agentfwd_enabled)
6220 error = "Agent forwarding is not enabled";
6222 c->type = CHAN_AGENT; /* identify channel type */
6223 c->u.a.lensofar = 0;
6226 error = "Unsupported channel type requested";
6229 c->remoteid = remid;
6231 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6232 ssh2_pkt_adduint32(ssh, c->remoteid);
6233 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6234 ssh2_pkt_addstring(ssh, error);
6235 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6237 logeventf(ssh, "Rejected channel open: %s", error);
6240 c->localid = alloc_channel_id(ssh);
6242 c->v.v2.locwindow = OUR_V2_WINSIZE;
6243 c->v.v2.remwindow = winsize;
6244 c->v.v2.remmaxpkt = pktsize;
6245 bufchain_init(&c->v.v2.outbuffer);
6246 add234(ssh->channels, c);
6247 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6248 ssh2_pkt_adduint32(ssh, c->remoteid);
6249 ssh2_pkt_adduint32(ssh, c->localid);
6250 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6251 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6255 bombout(("Strange packet received: type %d", ssh->pktin.type));
6260 * We have spare data. Add it to the channel buffer.
6262 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6267 struct ssh_channel *c;
6269 * Try to send data on all channels if we can.
6271 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6274 continue; /* don't send on closing channels */
6275 bufsize = ssh2_try_send(c);
6278 case CHAN_MAINSESSION:
6279 /* stdin need not receive an unthrottle
6280 * notification since it will be polled */
6283 x11_unthrottle(c->u.x11.s);
6286 /* agent sockets are request/response and need no
6287 * buffer management */
6290 pfd_unthrottle(c->u.pfd.s);
6302 * Handle the top-level SSH2 protocol.
6304 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6306 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6308 do_ssh2_authconn(ssh, in, inlen, ispkt);
6312 * Called to set up the connection.
6314 * Returns an error message, or NULL on success.
6316 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6318 char *host, int port, char **realhost, int nodelay,
6324 ssh = snew(struct ssh_tag);
6325 ssh->cfg = *cfg; /* STRUCTURE COPY */
6326 ssh->version = 0; /* when not ready yet */
6329 ssh->v1_cipher_ctx = NULL;
6330 ssh->crcda_ctx = NULL;
6331 ssh->cscipher = NULL;
6332 ssh->cs_cipher_ctx = NULL;
6333 ssh->sccipher = NULL;
6334 ssh->sc_cipher_ctx = NULL;
6336 ssh->cs_mac_ctx = NULL;
6338 ssh->sc_mac_ctx = NULL;
6340 ssh->cs_comp_ctx = NULL;
6342 ssh->sc_comp_ctx = NULL;
6344 ssh->kex_ctx = NULL;
6345 ssh->hostkey = NULL;
6347 ssh->state = SSH_STATE_PREPACKET;
6348 ssh->size_needed = FALSE;
6349 ssh->eof_needed = FALSE;
6353 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6354 ssh->pktin = ssh->pktout = empty;
6356 ssh->deferred_send_data = NULL;
6357 ssh->deferred_len = 0;
6358 ssh->deferred_size = 0;
6359 ssh->fallback_cmd = 0;
6361 ssh->x11auth = NULL;
6362 ssh->v1_compressing = FALSE;
6363 ssh->v2_outgoing_sequence = 0;
6364 ssh->ssh1_rdpkt_crstate = 0;
6365 ssh->ssh2_rdpkt_crstate = 0;
6366 ssh->do_ssh_init_crstate = 0;
6367 ssh->ssh_gotdata_crstate = 0;
6368 ssh->ssh1_protocol_crstate = 0;
6369 ssh->do_ssh1_login_crstate = 0;
6370 ssh->do_ssh2_transport_crstate = 0;
6371 ssh->do_ssh2_authconn_crstate = 0;
6372 ssh->do_ssh_init_state = NULL;
6373 ssh->do_ssh1_login_state = NULL;
6374 ssh->do_ssh2_transport_state = NULL;
6375 ssh->do_ssh2_authconn_state = NULL;
6376 ssh->mainchan = NULL;
6377 ssh->throttled_all = 0;
6378 ssh->v1_stdout_throttling = 0;
6380 *backend_handle = ssh;
6383 if (crypto_startup() == 0)
6384 return "Microsoft high encryption pack not installed!";
6387 ssh->frontend = frontend_handle;
6388 ssh->term_width = ssh->cfg.width;
6389 ssh->term_height = ssh->cfg.height;
6391 ssh->channels = NULL;
6392 ssh->rportfwds = NULL;
6397 ssh->v1_throttle_count = 0;
6398 ssh->overall_bufsize = 0;
6399 ssh->fallback_cmd = 0;
6401 ssh->protocol = NULL;
6403 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
6410 static void ssh_free(void *handle)
6412 Ssh ssh = (Ssh) handle;
6413 struct ssh_channel *c;
6414 struct ssh_rportfwd *pf;
6416 if (ssh->v1_cipher_ctx)
6417 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6418 if (ssh->cs_cipher_ctx)
6419 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6420 if (ssh->sc_cipher_ctx)
6421 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6422 if (ssh->cs_mac_ctx)
6423 ssh->csmac->free_context(ssh->cs_mac_ctx);
6424 if (ssh->sc_mac_ctx)
6425 ssh->scmac->free_context(ssh->sc_mac_ctx);
6426 if (ssh->cs_comp_ctx) {
6428 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6430 zlib_compress_cleanup(ssh->cs_comp_ctx);
6432 if (ssh->sc_comp_ctx) {
6434 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6436 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6439 dh_cleanup(ssh->kex_ctx);
6440 sfree(ssh->savedhost);
6442 if (ssh->channels) {
6443 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6446 if (c->u.x11.s != NULL)
6447 x11_close(c->u.x11.s);
6450 if (c->u.pfd.s != NULL)
6451 pfd_close(c->u.pfd.s);
6456 freetree234(ssh->channels);
6459 if (ssh->rportfwds) {
6460 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6462 freetree234(ssh->rportfwds);
6464 sfree(ssh->deferred_send_data);
6466 x11_free_auth(ssh->x11auth);
6467 sfree(ssh->do_ssh_init_state);
6468 sfree(ssh->do_ssh1_login_state);
6469 sfree(ssh->do_ssh2_transport_state);
6470 sfree(ssh->do_ssh2_authconn_state);
6471 if (ssh->pktout.data) {
6472 sfree(ssh->pktout.data);
6473 ssh->pktout.data = NULL;
6475 if (ssh->pktin.data) {
6476 sfree(ssh->pktin.data);
6477 ssh->pktin.data = NULL;
6479 if (ssh->crcda_ctx) {
6480 crcda_free_context(ssh->crcda_ctx);
6481 ssh->crcda_ctx = NULL;
6489 * Reconfigure the SSH backend.
6491 * Currently, this function does nothing very useful. In future,
6492 * however, we could do some handy things with it. For example, we
6493 * could make the port forwarding configurer active in the Change
6494 * Settings box, and this routine could close down existing
6495 * forwardings and open up new ones in response to changes.
6497 static void ssh_reconfig(void *handle, Config *cfg)
6499 Ssh ssh = (Ssh) handle;
6500 ssh->cfg = *cfg; /* STRUCTURE COPY */
6504 * Called to send data down the Telnet connection.
6506 static int ssh_send(void *handle, char *buf, int len)
6508 Ssh ssh = (Ssh) handle;
6510 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6513 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6515 return ssh_sendbuffer(ssh);
6519 * Called to query the current amount of buffered stdin data.
6521 static int ssh_sendbuffer(void *handle)
6523 Ssh ssh = (Ssh) handle;
6526 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6530 * If the SSH socket itself has backed up, add the total backup
6531 * size on that to any individual buffer on the stdin channel.
6534 if (ssh->throttled_all)
6535 override_value = ssh->overall_bufsize;
6537 if (ssh->version == 1) {
6538 return override_value;
6539 } else if (ssh->version == 2) {
6540 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6541 return override_value;
6543 return (override_value +
6544 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6551 * Called to set the size of the window from SSH's POV.
6553 static void ssh_size(void *handle, int width, int height)
6555 Ssh ssh = (Ssh) handle;
6557 ssh->term_width = width;
6558 ssh->term_height = height;
6560 switch (ssh->state) {
6561 case SSH_STATE_BEFORE_SIZE:
6562 case SSH_STATE_PREPACKET:
6563 case SSH_STATE_CLOSED:
6564 break; /* do nothing */
6565 case SSH_STATE_INTERMED:
6566 ssh->size_needed = TRUE; /* buffer for later */
6568 case SSH_STATE_SESSION:
6569 if (!ssh->cfg.nopty) {
6570 if (ssh->version == 1) {
6571 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6572 PKT_INT, ssh->term_height,
6573 PKT_INT, ssh->term_width,
6574 PKT_INT, 0, PKT_INT, 0, PKT_END);
6576 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6577 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6578 ssh2_pkt_addstring(ssh, "window-change");
6579 ssh2_pkt_addbool(ssh, 0);
6580 ssh2_pkt_adduint32(ssh, ssh->term_width);
6581 ssh2_pkt_adduint32(ssh, ssh->term_height);
6582 ssh2_pkt_adduint32(ssh, 0);
6583 ssh2_pkt_adduint32(ssh, 0);
6592 * Return a list of the special codes that make sense in this
6595 static const struct telnet_special *ssh_get_specials(void *handle)
6597 Ssh ssh = (Ssh) handle;
6599 if (ssh->version == 1) {
6600 static const struct telnet_special ssh1_specials[] = {
6601 {"IGNORE message", TS_NOP},
6604 return ssh1_specials;
6605 } else if (ssh->version == 2) {
6606 static const struct telnet_special ssh2_specials[] = {
6608 {"IGNORE message", TS_NOP},
6611 return ssh2_specials;
6617 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6618 * can send an EOF and collect resulting output (e.g. `plink
6621 static void ssh_special(void *handle, Telnet_Special code)
6623 Ssh ssh = (Ssh) handle;
6625 if (code == TS_EOF) {
6626 if (ssh->state != SSH_STATE_SESSION) {
6628 * Buffer the EOF in case we are pre-SESSION, so we can
6629 * send it as soon as we reach SESSION.
6632 ssh->eof_needed = TRUE;
6635 if (ssh->version == 1) {
6636 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6638 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6639 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6642 logevent("Sent EOF message");
6643 } else if (code == TS_PING || code == TS_NOP) {
6644 if (ssh->state == SSH_STATE_CLOSED
6645 || ssh->state == SSH_STATE_PREPACKET) return;
6646 if (ssh->version == 1) {
6647 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6648 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6650 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6651 ssh2_pkt_addstring_start(ssh);
6654 } else if (code == TS_BRK) {
6655 if (ssh->state == SSH_STATE_CLOSED
6656 || ssh->state == SSH_STATE_PREPACKET) return;
6657 if (ssh->version == 1) {
6658 logevent("Unable to send BREAK signal in SSH1");
6660 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6661 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6662 ssh2_pkt_addstring(ssh, "break");
6663 ssh2_pkt_addbool(ssh, 0);
6664 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6672 void *new_sock_channel(void *handle, Socket s)
6674 Ssh ssh = (Ssh) handle;
6675 struct ssh_channel *c;
6676 c = snew(struct ssh_channel);
6680 c->remoteid = -1; /* to be set when open confirmed */
6681 c->localid = alloc_channel_id(ssh);
6683 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6685 bufchain_init(&c->v.v2.outbuffer);
6686 add234(ssh->channels, c);
6692 * This is called when stdout/stderr (the entity to which
6693 * from_backend sends data) manages to clear some backlog.
6695 static void ssh_unthrottle(void *handle, int bufsize)
6697 Ssh ssh = (Ssh) handle;
6698 if (ssh->version == 1) {
6699 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6700 ssh->v1_stdout_throttling = 0;
6701 ssh1_throttle(ssh, -1);
6704 if (ssh->mainchan && ssh->mainchan->closes == 0)
6705 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6709 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6711 struct ssh_channel *c = (struct ssh_channel *)channel;
6714 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6716 if (ssh->version == 1) {
6717 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6718 PKT_INT, c->localid,
6721 //PKT_STR, <org:orgport>,
6724 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6725 ssh2_pkt_addstring(ssh, "direct-tcpip");
6726 ssh2_pkt_adduint32(ssh, c->localid);
6727 c->v.v2.locwindow = OUR_V2_WINSIZE;
6728 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6729 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6730 ssh2_pkt_addstring(ssh, hostname);
6731 ssh2_pkt_adduint32(ssh, port);
6733 * We make up values for the originator data; partly it's
6734 * too much hassle to keep track, and partly I'm not
6735 * convinced the server should be told details like that
6736 * about my local network configuration.
6738 ssh2_pkt_addstring(ssh, "client-side-connection");
6739 ssh2_pkt_adduint32(ssh, 0);
6745 static Socket ssh_socket(void *handle)
6747 Ssh ssh = (Ssh) handle;
6751 static int ssh_sendok(void *handle)
6753 Ssh ssh = (Ssh) handle;
6754 return ssh->send_ok;
6757 static int ssh_ldisc(void *handle, int option)
6759 Ssh ssh = (Ssh) handle;
6760 if (option == LD_ECHO)
6761 return ssh->echoing;
6762 if (option == LD_EDIT)
6763 return ssh->editing;
6767 static void ssh_provide_ldisc(void *handle, void *ldisc)
6769 Ssh ssh = (Ssh) handle;
6773 static void ssh_provide_logctx(void *handle, void *logctx)
6775 Ssh ssh = (Ssh) handle;
6776 ssh->logctx = logctx;
6779 static int ssh_return_exitcode(void *handle)
6781 Ssh ssh = (Ssh) handle;
6785 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6789 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6790 * that fails. This variable is the means by which scp.c can reach
6791 * into the SSH code and find out which one it got.
6793 extern int ssh_fallback_cmd(void *handle)
6795 Ssh ssh = (Ssh) handle;
6796 return ssh->fallback_cmd;
6799 Backend ssh_backend = {
6809 ssh_return_exitcode,