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 (st->biglen < 0) {
831 bombout(("Extremely large packet length from server suggests"
832 " data stream corruption"));
836 if (ssh->pktin.maxlen < st->biglen) {
837 ssh->pktin.maxlen = st->biglen;
838 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
842 st->to_read = st->biglen;
843 st->p = ssh->pktin.data;
844 while (st->to_read > 0) {
845 st->chunk = st->to_read;
846 while ((*datalen) == 0)
847 crReturn(st->to_read);
848 if (st->chunk > (*datalen))
849 st->chunk = (*datalen);
850 memcpy(st->p, *data, st->chunk);
852 *datalen -= st->chunk;
854 st->to_read -= st->chunk;
857 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
859 bombout(("Network attack (CRC compensation) detected!"));
864 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
866 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
867 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
868 if (st->gotcrc != st->realcrc) {
869 bombout(("Incorrect CRC received on packet"));
873 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
874 ssh->pktin.savedpos = 0;
876 if (ssh->v1_compressing) {
877 unsigned char *decompblk;
879 if (!zlib_decompress_block(ssh->sc_comp_ctx,
880 ssh->pktin.body - 1, ssh->pktin.length + 1,
881 &decompblk, &decomplen)) {
882 bombout(("Zlib decompression encountered invalid data"));
886 if (ssh->pktin.maxlen < st->pad + decomplen) {
887 ssh->pktin.maxlen = st->pad + decomplen;
888 ssh->pktin.data = sresize(ssh->pktin.data,
889 ssh->pktin.maxlen + APIEXTRA,
891 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
894 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
896 ssh->pktin.length = decomplen - 1;
899 ssh->pktin.type = ssh->pktin.body[-1];
902 log_packet(ssh->logctx,
903 PKT_INCOMING, ssh->pktin.type,
904 ssh1_pkt_type(ssh->pktin.type),
905 ssh->pktin.body, ssh->pktin.length);
907 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
908 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
909 ssh->pktin.type == SSH1_MSG_DEBUG ||
910 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
911 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
912 long stringlen = GET_32BIT(ssh->pktin.body);
913 if (stringlen + 4 != ssh->pktin.length) {
914 bombout(("Received data packet with bogus string length"));
919 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
920 /* log debug message */
922 int stringlen = GET_32BIT(ssh->pktin.body);
923 strcpy(buf, "Remote debug message: ");
926 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
927 buf[8 + stringlen] = '\0';
930 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
935 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
936 /* log reason code in disconnect message */
938 unsigned msglen = GET_32BIT(ssh->pktin.body);
940 strcpy(buf, "Remote sent disconnect: ");
941 nowlen = strlen(buf);
942 if (msglen > sizeof(buf) - nowlen - 1)
943 msglen = sizeof(buf) - nowlen - 1;
944 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
945 buf[nowlen + msglen] = '\0';
946 /* logevent(buf); (this is now done within the bombout macro) */
947 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
954 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
956 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
958 crBegin(ssh->ssh2_rdpkt_crstate);
962 ssh->pktin.length = 0;
964 st->cipherblk = ssh->sccipher->blksize;
967 if (st->cipherblk < 8)
970 if (ssh->pktin.maxlen < st->cipherblk) {
971 ssh->pktin.maxlen = st->cipherblk;
972 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
977 * Acquire and decrypt the first block of the packet. This will
978 * contain the length and padding details.
980 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
981 while ((*datalen) == 0)
982 crReturn(st->cipherblk - st->i);
983 ssh->pktin.data[st->i] = *(*data)++;
988 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
989 ssh->pktin.data, st->cipherblk);
992 * Now get the length and padding figures.
994 st->len = GET_32BIT(ssh->pktin.data);
995 st->pad = ssh->pktin.data[4];
998 * _Completely_ silly lengths should be stomped on before they
999 * do us any more damage.
1001 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1002 bombout(("Incoming packet was garbled on decryption"));
1007 * This enables us to deduce the payload length.
1009 st->payload = st->len - st->pad - 1;
1011 ssh->pktin.length = st->payload + 5;
1014 * So now we can work out the total packet length.
1016 st->packetlen = st->len + 4;
1017 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1020 * Adjust memory allocation if packet is too big.
1022 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1023 ssh->pktin.maxlen = st->packetlen + st->maclen;
1024 ssh->pktin.data = sresize(ssh->pktin.data,
1025 ssh->pktin.maxlen + APIEXTRA,
1030 * Read and decrypt the remainder of the packet.
1032 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1034 while ((*datalen) == 0)
1035 crReturn(st->packetlen + st->maclen - st->i);
1036 ssh->pktin.data[st->i] = *(*data)++;
1039 /* Decrypt everything _except_ the MAC. */
1041 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1042 ssh->pktin.data + st->cipherblk,
1043 st->packetlen - st->cipherblk);
1049 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1050 st->incoming_sequence)) {
1051 bombout(("Incorrect MAC received on packet"));
1054 st->incoming_sequence++; /* whether or not we MACed */
1057 * Decompress packet payload.
1060 unsigned char *newpayload;
1063 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1064 ssh->pktin.data + 5, ssh->pktin.length - 5,
1065 &newpayload, &newlen)) {
1066 if (ssh->pktin.maxlen < newlen + 5) {
1067 ssh->pktin.maxlen = newlen + 5;
1068 ssh->pktin.data = sresize(ssh->pktin.data,
1069 ssh->pktin.maxlen + APIEXTRA,
1072 ssh->pktin.length = 5 + newlen;
1073 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1078 ssh->pktin.savedpos = 6;
1079 ssh->pktin.body = ssh->pktin.data;
1080 ssh->pktin.type = ssh->pktin.data[5];
1083 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1084 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1085 ssh->pktin.data+6, ssh->pktin.length-6);
1087 switch (ssh->pktin.type) {
1089 * These packets we must handle instantly.
1091 case SSH2_MSG_DISCONNECT:
1093 /* log reason code in disconnect message */
1096 int reason = GET_32BIT(ssh->pktin.data + 6);
1097 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1099 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1100 buf = dupprintf("Received disconnect message (%s)",
1101 ssh2_disconnect_reasons[reason]);
1103 buf = dupprintf("Received disconnect message (unknown"
1104 " type %d)", reason);
1108 buf = dupprintf("Disconnection message text: %n%.*s",
1109 &nowlen, msglen, ssh->pktin.data + 14);
1111 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1113 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1114 ssh2_disconnect_reasons[reason] : "unknown",
1120 case SSH2_MSG_IGNORE:
1122 case SSH2_MSG_DEBUG:
1124 /* log the debug message */
1126 /* int display = ssh->pktin.body[6]; */
1127 int stringlen = GET_32BIT(ssh->pktin.data+7);
1129 strcpy(buf, "Remote debug message: ");
1130 prefix = strlen(buf);
1131 if (stringlen > (int)(sizeof(buf)-prefix-1))
1132 stringlen = sizeof(buf)-prefix-1;
1133 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1134 buf[prefix + stringlen] = '\0';
1137 goto next_packet; /* FIXME: print the debug message */
1140 * These packets we need do nothing about here.
1142 case SSH2_MSG_UNIMPLEMENTED:
1143 case SSH2_MSG_SERVICE_REQUEST:
1144 case SSH2_MSG_SERVICE_ACCEPT:
1145 case SSH2_MSG_KEXINIT:
1146 case SSH2_MSG_NEWKEYS:
1147 case SSH2_MSG_KEXDH_INIT:
1148 case SSH2_MSG_KEXDH_REPLY:
1149 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1150 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1151 case SSH2_MSG_KEX_DH_GEX_INIT:
1152 case SSH2_MSG_KEX_DH_GEX_REPLY:
1153 case SSH2_MSG_USERAUTH_REQUEST:
1154 case SSH2_MSG_USERAUTH_FAILURE:
1155 case SSH2_MSG_USERAUTH_SUCCESS:
1156 case SSH2_MSG_USERAUTH_BANNER:
1157 case SSH2_MSG_USERAUTH_PK_OK:
1158 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1159 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1160 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1161 case SSH2_MSG_GLOBAL_REQUEST:
1162 case SSH2_MSG_REQUEST_SUCCESS:
1163 case SSH2_MSG_REQUEST_FAILURE:
1164 case SSH2_MSG_CHANNEL_OPEN:
1165 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1166 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1167 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1168 case SSH2_MSG_CHANNEL_DATA:
1169 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1170 case SSH2_MSG_CHANNEL_EOF:
1171 case SSH2_MSG_CHANNEL_CLOSE:
1172 case SSH2_MSG_CHANNEL_REQUEST:
1173 case SSH2_MSG_CHANNEL_SUCCESS:
1174 case SSH2_MSG_CHANNEL_FAILURE:
1178 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1181 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1182 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1190 static void ssh1_pktout_size(Ssh ssh, int len)
1194 len += 5; /* type and CRC */
1195 pad = 8 - (len % 8);
1198 ssh->pktout.length = len - 5;
1199 if (ssh->pktout.maxlen < biglen) {
1200 ssh->pktout.maxlen = biglen;
1202 /* Allocate enough buffer space for extra block
1203 * for MS CryptEncrypt() */
1204 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1207 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1211 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1214 static void s_wrpkt_start(Ssh ssh, int type, int len)
1216 ssh1_pktout_size(ssh, len);
1217 ssh->pktout.type = type;
1220 static int s_wrpkt_prepare(Ssh ssh)
1226 * XXX various versions of SC (including 8.8.4) screw up the
1227 * register allocation in this function and use the same register
1228 * (D6) for len and as a temporary, with predictable results. The
1229 * following sledgehammer prevents this.
1235 ssh->pktout.body[-1] = ssh->pktout.type;
1238 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1239 ssh1_pkt_type(ssh->pktout.type),
1240 ssh->pktout.body, ssh->pktout.length);
1242 if (ssh->v1_compressing) {
1243 unsigned char *compblk;
1245 zlib_compress_block(ssh->cs_comp_ctx,
1246 ssh->pktout.body - 1, ssh->pktout.length + 1,
1247 &compblk, &complen);
1248 ssh1_pktout_size(ssh, complen - 1);
1249 memcpy(ssh->pktout.body - 1, compblk, complen);
1253 len = ssh->pktout.length + 5; /* type and CRC */
1254 pad = 8 - (len % 8);
1257 for (i = 0; i < pad; i++)
1258 ssh->pktout.data[i + 4] = random_byte();
1259 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1260 PUT_32BIT(ssh->pktout.data + biglen, crc);
1261 PUT_32BIT(ssh->pktout.data, len);
1264 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1269 static void s_wrpkt(Ssh ssh)
1272 len = s_wrpkt_prepare(ssh);
1273 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1274 if (backlog > SSH_MAX_BACKLOG)
1275 ssh_throttle_all(ssh, 1, backlog);
1278 static void s_wrpkt_defer(Ssh ssh)
1281 len = s_wrpkt_prepare(ssh);
1282 if (ssh->deferred_len + len > ssh->deferred_size) {
1283 ssh->deferred_size = ssh->deferred_len + len + 128;
1284 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1288 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1289 ssh->deferred_len += len;
1293 * Construct a packet with the specified contents.
1295 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1297 unsigned char *p, *argp, argchar;
1298 unsigned long argint;
1299 int pktlen, argtype, arglen;
1303 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1306 (void) va_arg(ap1, int);
1310 (void) va_arg(ap1, int);
1314 (void) va_arg(ap1, unsigned char *);
1315 arglen = va_arg(ap1, int);
1319 argp = va_arg(ap1, unsigned char *);
1320 arglen = strlen((char *)argp);
1321 pktlen += 4 + arglen;
1324 bn = va_arg(ap1, Bignum);
1325 pktlen += ssh1_bignum_length(bn);
1332 s_wrpkt_start(ssh, pkttype, pktlen);
1333 p = ssh->pktout.body;
1335 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1338 argint = va_arg(ap2, int);
1339 PUT_32BIT(p, argint);
1343 argchar = (unsigned char) va_arg(ap2, int);
1348 argp = va_arg(ap2, unsigned char *);
1349 arglen = va_arg(ap2, int);
1350 memcpy(p, argp, arglen);
1354 argp = va_arg(ap2, unsigned char *);
1355 arglen = strlen((char *)argp);
1356 PUT_32BIT(p, arglen);
1357 memcpy(p + 4, argp, arglen);
1361 bn = va_arg(ap2, Bignum);
1362 p += ssh1_write_bignum(p, bn);
1368 static void send_packet(Ssh ssh, int pkttype, ...)
1371 va_start(ap1, pkttype);
1372 va_start(ap2, pkttype);
1373 construct_packet(ssh, pkttype, ap1, ap2);
1377 static void defer_packet(Ssh ssh, int pkttype, ...)
1380 va_start(ap1, pkttype);
1381 va_start(ap2, pkttype);
1382 construct_packet(ssh, pkttype, ap1, ap2);
1386 static int ssh_versioncmp(char *a, char *b)
1389 unsigned long av, bv;
1391 av = strtoul(a, &ae, 10);
1392 bv = strtoul(b, &be, 10);
1394 return (av < bv ? -1 : +1);
1399 av = strtoul(ae, &ae, 10);
1400 bv = strtoul(be, &be, 10);
1402 return (av < bv ? -1 : +1);
1407 * Utility routines for putting an SSH-protocol `string' and
1408 * `uint32' into a SHA state.
1411 static void sha_string(SHA_State * s, void *str, int len)
1413 unsigned char lenblk[4];
1414 PUT_32BIT(lenblk, len);
1415 SHA_Bytes(s, lenblk, 4);
1416 SHA_Bytes(s, str, len);
1419 static void sha_uint32(SHA_State * s, unsigned i)
1421 unsigned char intblk[4];
1422 PUT_32BIT(intblk, i);
1423 SHA_Bytes(s, intblk, 4);
1427 * SSH2 packet construction functions.
1429 static void ssh2_pkt_ensure(Ssh ssh, int length)
1431 if (ssh->pktout.maxlen < length) {
1432 ssh->pktout.maxlen = length + 256;
1433 ssh->pktout.data = sresize(ssh->pktout.data,
1434 ssh->pktout.maxlen + APIEXTRA,
1436 if (!ssh->pktout.data)
1437 fatalbox("Out of memory");
1440 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1442 ssh->pktout.length += len;
1443 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1444 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1446 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1448 ssh2_pkt_adddata(ssh, &byte, 1);
1450 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1452 ssh->pktout.length = 5;
1453 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1455 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1457 ssh2_pkt_adddata(ssh, &value, 1);
1459 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1462 PUT_32BIT(x, value);
1463 ssh2_pkt_adddata(ssh, x, 4);
1465 static void ssh2_pkt_addstring_start(Ssh ssh)
1467 ssh2_pkt_adduint32(ssh, 0);
1468 ssh->pktout.savedpos = ssh->pktout.length;
1470 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1472 ssh2_pkt_adddata(ssh, data, strlen(data));
1473 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1474 ssh->pktout.length - ssh->pktout.savedpos);
1476 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1478 ssh2_pkt_adddata(ssh, data, len);
1479 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1480 ssh->pktout.length - ssh->pktout.savedpos);
1482 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1484 ssh2_pkt_addstring_start(ssh);
1485 ssh2_pkt_addstring_str(ssh, data);
1487 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1490 int i, n = (bignum_bitcount(b) + 7) / 8;
1491 p = snewn(n + 1, unsigned char);
1493 fatalbox("out of memory");
1495 for (i = 1; i <= n; i++)
1496 p[i] = bignum_byte(b, n - i);
1498 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1500 memmove(p, p + i, n + 1 - i);
1504 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1508 p = ssh2_mpint_fmt(b, &len);
1509 ssh2_pkt_addstring_start(ssh);
1510 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1515 * Construct an SSH2 final-form packet: compress it, encrypt it,
1516 * put the MAC on it. Final packet, ready to be sent, is stored in
1517 * ssh->pktout.data. Total length is returned.
1519 static int ssh2_pkt_construct(Ssh ssh)
1521 int cipherblk, maclen, padding, i;
1524 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1525 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1526 ssh->pktout.data + 6, ssh->pktout.length - 6);
1529 * Compress packet payload.
1532 unsigned char *newpayload;
1535 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1536 ssh->pktout.length - 5,
1537 &newpayload, &newlen)) {
1538 ssh->pktout.length = 5;
1539 ssh2_pkt_adddata(ssh, newpayload, newlen);
1545 * Add padding. At least four bytes, and must also bring total
1546 * length (minus MAC) up to a multiple of the block size.
1548 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1549 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1552 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1553 maclen = ssh->csmac ? ssh->csmac->len : 0;
1554 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1555 ssh->pktout.data[4] = padding;
1556 for (i = 0; i < padding; i++)
1557 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1558 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1560 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1561 ssh->pktout.length + padding,
1562 ssh->v2_outgoing_sequence);
1563 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1566 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1567 ssh->pktout.data, ssh->pktout.length + padding);
1569 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1570 return ssh->pktout.length + padding + maclen;
1574 * Construct and send an SSH2 packet immediately.
1576 static void ssh2_pkt_send(Ssh ssh)
1580 len = ssh2_pkt_construct(ssh);
1581 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1582 if (backlog > SSH_MAX_BACKLOG)
1583 ssh_throttle_all(ssh, 1, backlog);
1587 * Construct an SSH2 packet and add it to a deferred data block.
1588 * Useful for sending multiple packets in a single sk_write() call,
1589 * to prevent a traffic-analysing listener from being able to work
1590 * out the length of any particular packet (such as the password
1593 * Note that because SSH2 sequence-numbers its packets, this can
1594 * NOT be used as an m4-style `defer' allowing packets to be
1595 * constructed in one order and sent in another.
1597 static void ssh2_pkt_defer(Ssh ssh)
1599 int len = ssh2_pkt_construct(ssh);
1600 if (ssh->deferred_len + len > ssh->deferred_size) {
1601 ssh->deferred_size = ssh->deferred_len + len + 128;
1602 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1606 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1607 ssh->deferred_len += len;
1611 * Send the whole deferred data block constructed by
1612 * ssh2_pkt_defer() or SSH1's defer_packet().
1614 static void ssh_pkt_defersend(Ssh ssh)
1617 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1619 ssh->deferred_len = ssh->deferred_size = 0;
1620 sfree(ssh->deferred_send_data);
1621 ssh->deferred_send_data = NULL;
1622 if (backlog > SSH_MAX_BACKLOG)
1623 ssh_throttle_all(ssh, 1, backlog);
1627 void bndebug(char *string, Bignum b)
1631 p = ssh2_mpint_fmt(b, &len);
1632 debug(("%s", string));
1633 for (i = 0; i < len; i++)
1634 debug((" %02x", p[i]));
1640 static void sha_mpint(SHA_State * s, Bignum b)
1644 p = ssh2_mpint_fmt(b, &len);
1645 sha_string(s, p, len);
1650 * Packet decode functions for both SSH1 and SSH2.
1652 static unsigned long ssh_pkt_getuint32(Ssh ssh)
1654 unsigned long value;
1655 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1656 return 0; /* arrgh, no way to decline (FIXME?) */
1657 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1658 ssh->pktin.savedpos += 4;
1661 static int ssh2_pkt_getbool(Ssh ssh)
1663 unsigned long value;
1664 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1665 return 0; /* arrgh, no way to decline (FIXME?) */
1666 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
1667 ssh->pktin.savedpos++;
1670 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
1675 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1677 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1681 ssh->pktin.savedpos += 4;
1682 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1684 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
1685 ssh->pktin.savedpos += *length;
1687 static void *ssh_pkt_getdata(Ssh ssh, int length)
1689 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1691 ssh->pktin.savedpos += length;
1692 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1694 static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1695 unsigned char **keystr)
1699 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1700 ssh->pktin.length - ssh->pktin.savedpos,
1706 ssh->pktin.savedpos += j;
1707 assert(ssh->pktin.savedpos < ssh->pktin.length);
1711 static Bignum ssh1_pkt_getmp(Ssh ssh)
1716 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1717 ssh->pktin.length - ssh->pktin.savedpos, &b);
1722 ssh->pktin.savedpos += j;
1725 static Bignum ssh2_pkt_getmp(Ssh ssh)
1731 ssh_pkt_getstring(ssh, &p, &length);
1735 bombout(("internal error: Can't handle negative mpints"));
1738 b = bignum_from_bytes((unsigned char *)p, length);
1743 * Helper function to add an SSH2 signature blob to a packet.
1744 * Expects to be shown the public key blob as well as the signature
1745 * blob. Normally works just like ssh2_pkt_addstring, but will
1746 * fiddle with the signature packet if necessary for
1747 * BUG_SSH2_RSA_PADDING.
1749 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1750 void *sigblob_v, int sigblob_len)
1752 unsigned char *pkblob = (unsigned char *)pkblob_v;
1753 unsigned char *sigblob = (unsigned char *)sigblob_v;
1755 /* dmemdump(pkblob, pkblob_len); */
1756 /* dmemdump(sigblob, sigblob_len); */
1759 * See if this is in fact an ssh-rsa signature and a buggy
1760 * server; otherwise we can just do this the easy way.
1762 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1763 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1764 int pos, len, siglen;
1767 * Find the byte length of the modulus.
1770 pos = 4+7; /* skip over "ssh-rsa" */
1771 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1772 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1773 pos += 4; /* find modulus itself */
1774 while (len > 0 && pkblob[pos] == 0)
1776 /* debug(("modulus length is %d\n", len)); */
1779 * Now find the signature integer.
1781 pos = 4+7; /* skip over "ssh-rsa" */
1782 siglen = GET_32BIT(sigblob+pos);
1783 /* debug(("signature length is %d\n", siglen)); */
1785 if (len != siglen) {
1786 unsigned char newlen[4];
1787 ssh2_pkt_addstring_start(ssh);
1788 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1789 /* dmemdump(sigblob, pos); */
1790 pos += 4; /* point to start of actual sig */
1791 PUT_32BIT(newlen, len);
1792 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1793 /* dmemdump(newlen, 4); */
1795 while (len-- > siglen) {
1796 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1797 /* dmemdump(newlen, 1); */
1799 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1800 /* dmemdump(sigblob+pos, siglen); */
1804 /* Otherwise fall through and do it the easy way. */
1807 ssh2_pkt_addstring_start(ssh);
1808 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1812 * Examine the remote side's version string and compare it against
1813 * a list of known buggy implementations.
1815 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1817 char *imp; /* pointer to implementation part */
1819 imp += strcspn(imp, "-");
1821 imp += strcspn(imp, "-");
1824 ssh->remote_bugs = 0;
1826 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1827 (ssh->cfg.sshbug_ignore1 == AUTO &&
1828 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1829 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1830 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1831 !strcmp(imp, "OSU_1.4alpha3")))) {
1833 * These versions don't support SSH1_MSG_IGNORE, so we have
1834 * to use a different defence against password length
1837 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1838 logevent("We believe remote version has SSH1 ignore bug");
1841 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1842 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1843 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1845 * These versions need a plain password sent; they can't
1846 * handle having a null and a random length of data after
1849 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1850 logevent("We believe remote version needs a plain SSH1 password");
1853 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1854 (ssh->cfg.sshbug_rsa1 == AUTO &&
1855 (!strcmp(imp, "Cisco-1.25")))) {
1857 * These versions apparently have no clue whatever about
1858 * RSA authentication and will panic and die if they see
1859 * an AUTH_RSA message.
1861 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1862 logevent("We believe remote version can't handle RSA authentication");
1865 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1866 (ssh->cfg.sshbug_hmac2 == AUTO &&
1867 !wc_match("* VShell", imp) &&
1868 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1869 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1870 wc_match("2.1 *", imp)))) {
1872 * These versions have the HMAC bug.
1874 ssh->remote_bugs |= BUG_SSH2_HMAC;
1875 logevent("We believe remote version has SSH2 HMAC bug");
1878 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1879 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1880 !wc_match("* VShell", imp) &&
1881 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1883 * These versions have the key-derivation bug (failing to
1884 * include the literal shared secret in the hashes that
1885 * generate the keys).
1887 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1888 logevent("We believe remote version has SSH2 key-derivation bug");
1891 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1892 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1893 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1894 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1896 * These versions have the SSH2 RSA padding bug.
1898 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1899 logevent("We believe remote version has SSH2 RSA padding bug");
1902 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1903 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1904 wc_match("OpenSSH_2.[0-2]*", imp))) {
1906 * These versions have the SSH2 session-ID bug in
1907 * public-key authentication.
1909 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1910 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1913 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1915 * User specified the SSH2 DH GEX bug.
1917 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1918 logevent("We believe remote version has SSH2 DH group exchange bug");
1922 static int do_ssh_init(Ssh ssh, unsigned char c)
1924 struct do_ssh_init_state {
1932 crState(do_ssh_init_state);
1934 crBegin(ssh->do_ssh_init_crstate);
1936 /* Search for the string "SSH-" in the input. */
1939 static const int transS[] = { 1, 2, 2, 1 };
1940 static const int transH[] = { 0, 0, 3, 0 };
1941 static const int transminus[] = { 0, 0, 0, -1 };
1943 s->i = transS[s->i];
1945 s->i = transH[s->i];
1947 s->i = transminus[s->i];
1952 crReturn(1); /* get another character */
1956 s->vstring = snewn(s->vstrsize, char);
1957 strcpy(s->vstring, "SSH-");
1961 crReturn(1); /* get another char */
1962 if (s->vslen >= s->vstrsize - 1) {
1964 s->vstring = sresize(s->vstring, s->vstrsize, char);
1966 s->vstring[s->vslen++] = c;
1969 s->version[s->i] = '\0';
1971 } else if (s->i < sizeof(s->version) - 1)
1972 s->version[s->i++] = c;
1973 } else if (c == '\012')
1977 ssh->agentfwd_enabled = FALSE;
1978 ssh->rdpkt2_state.incoming_sequence = 0;
1980 s->vstring[s->vslen] = 0;
1981 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1984 vlog = snewn(20 + s->vslen, char);
1985 sprintf(vlog, "Server version: %s", s->vstring);
1989 ssh_detect_bugs(ssh, s->vstring);
1992 * Decide which SSH protocol version to support.
1995 /* Anything strictly below "2.0" means protocol 1 is supported. */
1996 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1997 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1998 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2000 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2001 bombout(("SSH protocol version 1 required by user but not provided by server"));
2004 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2005 bombout(("SSH protocol version 2 required by user but not provided by server"));
2009 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2013 char verstring[80], vlog[100];
2014 sprintf(verstring, "SSH-2.0-%s", sshver);
2015 SHA_Init(&ssh->exhashbase);
2017 * Hash our version string and their version string.
2019 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2020 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2021 sprintf(vlog, "We claim version: %s", verstring);
2023 strcat(verstring, "\012");
2024 logevent("Using SSH protocol version 2");
2025 sk_write(ssh->s, verstring, strlen(verstring));
2026 ssh->protocol = ssh2_protocol;
2028 ssh->s_rdpkt = ssh2_rdpkt;
2033 char verstring[80], vlog[100];
2034 sprintf(verstring, "SSH-%s-%s",
2035 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
2037 sprintf(vlog, "We claim version: %s", verstring);
2039 strcat(verstring, "\012");
2041 logevent("Using SSH protocol version 1");
2042 sk_write(ssh->s, verstring, strlen(verstring));
2043 ssh->protocol = ssh1_protocol;
2045 ssh->s_rdpkt = ssh1_rdpkt;
2047 update_specials_menu(ssh->frontend);
2048 ssh->state = SSH_STATE_BEFORE_SIZE;
2055 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2057 crBegin(ssh->ssh_gotdata_crstate);
2060 * To begin with, feed the characters one by one to the
2061 * protocol initialisation / selection function do_ssh_init().
2062 * When that returns 0, we're done with the initial greeting
2063 * exchange and can move on to packet discipline.
2066 int ret; /* need not be kept across crReturn */
2068 crReturnV; /* more data please */
2069 ret = do_ssh_init(ssh, *data);
2077 * We emerge from that loop when the initial negotiation is
2078 * over and we have selected an s_rdpkt function. Now pass
2079 * everything to s_rdpkt, and then pass the resulting packets
2080 * to the proper protocol handler.
2085 while (datalen > 0) {
2086 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2087 if (ssh->state == SSH_STATE_CLOSED) {
2090 ssh->protocol(ssh, NULL, 0, 1);
2091 if (ssh->state == SSH_STATE_CLOSED) {
2101 static void ssh_do_close(Ssh ssh)
2104 struct ssh_channel *c;
2106 ssh->state = SSH_STATE_CLOSED;
2112 * Now we must shut down any port and X forwardings going
2113 * through this connection.
2115 if (ssh->channels) {
2116 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2119 x11_close(c->u.x11.s);
2122 pfd_close(c->u.pfd.s);
2125 del234(ssh->channels, c);
2126 if (ssh->version == 2)
2127 bufchain_clear(&c->v.v2.outbuffer);
2133 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2136 Ssh ssh = (Ssh) plug;
2139 /* A socket error has occurred. */
2140 logevent(error_msg);
2141 connection_fatal(ssh->frontend, "%s", error_msg);
2143 /* Otherwise, the remote side closed the connection normally. */
2148 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2150 Ssh ssh = (Ssh) plug;
2151 ssh_gotdata(ssh, (unsigned char *)data, len);
2152 if (ssh->state == SSH_STATE_CLOSED) {
2159 static void ssh_sent(Plug plug, int bufsize)
2161 Ssh ssh = (Ssh) plug;
2163 * If the send backlog on the SSH socket itself clears, we
2164 * should unthrottle the whole world if it was throttled.
2166 if (bufsize < SSH_MAX_BACKLOG)
2167 ssh_throttle_all(ssh, 0, bufsize);
2171 * Connect to specified host and port.
2172 * Returns an error message, or NULL on success.
2173 * Also places the canonical host name into `realhost'. It must be
2174 * freed by the caller.
2176 static const char *connect_to_host(Ssh ssh, char *host, int port,
2177 char **realhost, int nodelay, int keepalive)
2179 static const struct plug_function_table fn_table = {
2189 ssh->savedhost = snewn(1 + strlen(host), char);
2190 if (!ssh->savedhost)
2191 fatalbox("Out of memory");
2192 strcpy(ssh->savedhost, host);
2195 port = 22; /* default ssh port */
2196 ssh->savedport = port;
2201 logeventf(ssh, "Looking up host \"%s\"", host);
2202 addr = name_lookup(host, port, realhost, &ssh->cfg);
2203 if ((err = sk_addr_error(addr)) != NULL) {
2213 sk_getaddr(addr, addrbuf, 100);
2214 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2216 ssh->fn = &fn_table;
2217 ssh->s = new_connection(addr, *realhost, port,
2218 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2219 if ((err = sk_socket_error(ssh->s)) != NULL) {
2228 * Throttle or unthrottle the SSH connection.
2230 static void ssh1_throttle(Ssh ssh, int adjust)
2232 int old_count = ssh->v1_throttle_count;
2233 ssh->v1_throttle_count += adjust;
2234 assert(ssh->v1_throttle_count >= 0);
2235 if (ssh->v1_throttle_count && !old_count) {
2236 sk_set_frozen(ssh->s, 1);
2237 } else if (!ssh->v1_throttle_count && old_count) {
2238 sk_set_frozen(ssh->s, 0);
2243 * Throttle or unthrottle _all_ local data streams (for when sends
2244 * on the SSH connection itself back up).
2246 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2249 struct ssh_channel *c;
2251 if (enable == ssh->throttled_all)
2253 ssh->throttled_all = enable;
2254 ssh->overall_bufsize = bufsize;
2257 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2259 case CHAN_MAINSESSION:
2261 * This is treated separately, outside the switch.
2265 x11_override_throttle(c->u.x11.s, enable);
2268 /* Agent channels require no buffer management. */
2271 pfd_override_throttle(c->u.pfd.s, enable);
2278 * Username and password input, abstracted off into routines
2279 * reusable in several places - even between SSH1 and SSH2.
2282 /* Set up a username or password input loop on a given buffer. */
2283 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2285 ssh->userpass_input_buffer = buffer;
2286 ssh->userpass_input_buflen = buflen;
2287 ssh->userpass_input_bufpos = 0;
2288 ssh->userpass_input_echo = echo;
2292 * Process some terminal data in the course of username/password
2293 * input. Returns >0 for success (line of input returned in
2294 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2295 * for inconclusive (keep waiting for more input please).
2297 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2302 switch (c = *in++) {
2305 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2306 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2311 if (ssh->userpass_input_bufpos > 0) {
2312 if (ssh->userpass_input_echo)
2313 c_write_str(ssh, "\b \b");
2314 ssh->userpass_input_bufpos--;
2319 while (ssh->userpass_input_bufpos > 0) {
2320 if (ssh->userpass_input_echo)
2321 c_write_str(ssh, "\b \b");
2322 ssh->userpass_input_bufpos--;
2331 * This simplistic check for printability is disabled
2332 * when we're doing password input, because some people
2333 * have control characters in their passwords.o
2335 if ((!ssh->userpass_input_echo ||
2336 (c >= ' ' && c <= '~') ||
2337 ((unsigned char) c >= 160))
2338 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2339 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2340 if (ssh->userpass_input_echo)
2341 c_write(ssh, &c, 1);
2349 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2351 Ssh ssh = (Ssh) sshv;
2353 ssh->agent_response = reply;
2354 ssh->agent_response_len = replylen;
2356 if (ssh->version == 1)
2357 do_ssh1_login(ssh, NULL, -1, 0);
2359 do_ssh2_authconn(ssh, NULL, -1, 0);
2362 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2364 struct ssh_channel *c = (struct ssh_channel *)cv;
2366 void *sentreply = reply;
2369 /* Fake SSH_AGENT_FAILURE. */
2370 sentreply = "\0\0\0\1\5";
2373 if (ssh->version == 2) {
2374 ssh2_add_channel_data(c, sentreply, replylen);
2377 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2378 PKT_INT, c->remoteid,
2380 PKT_DATA, sentreply, replylen,
2388 * Handle the key exchange and user authentication phases.
2390 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2393 unsigned char cookie[8], *ptr;
2394 struct RSAKey servkey, hostkey;
2395 struct MD5Context md5c;
2396 struct do_ssh1_login_state {
2398 unsigned char *rsabuf, *keystr1, *keystr2;
2399 unsigned long supported_ciphers_mask, supported_auths_mask;
2400 int tried_publickey, tried_agent;
2401 int tis_auth_refused, ccard_auth_refused;
2402 unsigned char session_id[16];
2405 void *publickey_blob;
2406 int publickey_bloblen;
2412 unsigned char request[5], *response, *p;
2421 crState(do_ssh1_login_state);
2423 crBegin(ssh->do_ssh1_login_crstate);
2428 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2429 bombout(("Public key packet not received"));
2433 logevent("Received public keys");
2435 ptr = ssh_pkt_getdata(ssh, 8);
2437 bombout(("SSH1 public key packet stopped before random cookie"));
2440 memcpy(cookie, ptr, 8);
2442 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2443 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
2444 bombout(("Failed to read SSH1 public keys from public key packet"));
2449 * Log the host key fingerprint.
2453 logevent("Host key fingerprint is:");
2454 strcpy(logmsg, " ");
2455 hostkey.comment = NULL;
2456 rsa_fingerprint(logmsg + strlen(logmsg),
2457 sizeof(logmsg) - strlen(logmsg), &hostkey);
2461 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2462 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2463 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
2465 ssh->v1_local_protoflags =
2466 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2467 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2470 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2471 MD5Update(&md5c, s->keystr1, servkey.bytes);
2472 MD5Update(&md5c, cookie, 8);
2473 MD5Final(s->session_id, &md5c);
2475 for (i = 0; i < 32; i++)
2476 ssh->session_key[i] = random_byte();
2479 * Verify that the `bits' and `bytes' parameters match.
2481 if (hostkey.bits > hostkey.bytes * 8 ||
2482 servkey.bits > servkey.bytes * 8) {
2483 bombout(("SSH1 public keys were badly formatted"));
2487 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2489 s->rsabuf = snewn(s->len, unsigned char);
2491 fatalbox("Out of memory");
2494 * Verify the host key.
2498 * First format the key into a string.
2500 int len = rsastr_len(&hostkey);
2501 char fingerprint[100];
2502 char *keystr = snewn(len, char);
2504 fatalbox("Out of memory");
2505 rsastr_fmt(keystr, &hostkey);
2506 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2507 verify_ssh_host_key(ssh->frontend,
2508 ssh->savedhost, ssh->savedport, "rsa", keystr,
2513 for (i = 0; i < 32; i++) {
2514 s->rsabuf[i] = ssh->session_key[i];
2516 s->rsabuf[i] ^= s->session_id[i];
2519 if (hostkey.bytes > servkey.bytes) {
2520 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2522 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2524 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2526 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2529 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2533 logevent("Encrypted session key");
2536 int cipher_chosen = 0, warn = 0;
2537 char *cipher_string = NULL;
2539 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2540 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2541 if (next_cipher == CIPHER_WARN) {
2542 /* If/when we choose a cipher, warn about it */
2544 } else if (next_cipher == CIPHER_AES) {
2545 /* XXX Probably don't need to mention this. */
2546 logevent("AES not supported in SSH1, skipping");
2548 switch (next_cipher) {
2549 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2550 cipher_string = "3DES"; break;
2551 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2552 cipher_string = "Blowfish"; break;
2553 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2554 cipher_string = "single-DES"; break;
2556 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2560 if (!cipher_chosen) {
2561 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2562 bombout(("Server violates SSH 1 protocol by not "
2563 "supporting 3DES encryption"));
2565 /* shouldn't happen */
2566 bombout(("No supported ciphers found"));
2570 /* Warn about chosen cipher if necessary. */
2572 askcipher(ssh->frontend, cipher_string, 0);
2575 switch (s->cipher_type) {
2576 case SSH_CIPHER_3DES:
2577 logevent("Using 3DES encryption");
2579 case SSH_CIPHER_DES:
2580 logevent("Using single-DES encryption");
2582 case SSH_CIPHER_BLOWFISH:
2583 logevent("Using Blowfish encryption");
2587 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2588 PKT_CHAR, s->cipher_type,
2589 PKT_DATA, cookie, 8,
2590 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2591 PKT_DATA, s->rsabuf, s->len,
2592 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2594 logevent("Trying to enable encryption...");
2598 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2599 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2601 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2602 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2603 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2605 ssh->crcda_ctx = crcda_make_context();
2606 logevent("Installing CRC compensation attack detector");
2608 if (servkey.modulus) {
2609 sfree(servkey.modulus);
2610 servkey.modulus = NULL;
2612 if (servkey.exponent) {
2613 sfree(servkey.exponent);
2614 servkey.exponent = NULL;
2616 if (hostkey.modulus) {
2617 sfree(hostkey.modulus);
2618 hostkey.modulus = NULL;
2620 if (hostkey.exponent) {
2621 sfree(hostkey.exponent);
2622 hostkey.exponent = NULL;
2626 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2627 bombout(("Encryption not successfully enabled"));
2631 logevent("Successfully started encryption");
2635 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2636 if (ssh_get_line && !ssh_getline_pw_only) {
2637 if (!ssh_get_line("login as: ",
2638 s->username, sizeof(s->username), FALSE)) {
2640 * get_line failed to get a username.
2643 logevent("No username provided. Abandoning session.");
2644 ssh_closing((Plug)ssh, NULL, 0, 0);
2648 int ret; /* need not be kept over crReturn */
2649 c_write_str(ssh, "login as: ");
2652 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2654 crWaitUntil(!ispkt);
2655 ret = process_userpass_input(ssh, in, inlen);
2659 c_write_str(ssh, "\r\n");
2662 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2663 s->username[sizeof(s->username)-1] = '\0';
2666 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2668 char userlog[22 + sizeof(s->username)];
2669 sprintf(userlog, "Sent username \"%s\"", s->username);
2671 if (flags & FLAG_INTERACTIVE &&
2672 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2673 strcat(userlog, "\r\n");
2674 c_write_str(ssh, userlog);
2681 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2682 /* We must not attempt PK auth. Pretend we've already tried it. */
2683 s->tried_publickey = s->tried_agent = 1;
2685 s->tried_publickey = s->tried_agent = 0;
2687 s->tis_auth_refused = s->ccard_auth_refused = 0;
2688 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2689 if (!filename_is_null(ssh->cfg.keyfile)) {
2690 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2691 &s->publickey_blob, &s->publickey_bloblen, NULL))
2692 s->publickey_blob = NULL;
2694 s->publickey_blob = NULL;
2696 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2697 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2699 if (agent_exists() && !s->tried_agent) {
2701 * Attempt RSA authentication using Pageant.
2707 logevent("Pageant is running. Requesting keys.");
2709 /* Request the keys held by the agent. */
2710 PUT_32BIT(s->request, 1);
2711 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2712 if (!agent_query(s->request, 5, &r, &s->responselen,
2713 ssh_agent_callback, ssh)) {
2717 bombout(("Unexpected data from server while waiting"
2718 " for agent response"));
2721 } while (ispkt || inlen > 0);
2722 r = ssh->agent_response;
2723 s->responselen = ssh->agent_response_len;
2725 s->response = (unsigned char *) r;
2726 if (s->response && s->responselen >= 5 &&
2727 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2728 s->p = s->response + 5;
2729 s->nkeys = GET_32BIT(s->p);
2733 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2736 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2739 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2742 if (s->publickey_blob &&
2743 !memcmp(s->p, s->publickey_blob,
2744 s->publickey_bloblen)) {
2745 logevent("This key matches configured key file");
2746 s->tried_publickey = 1;
2751 do { /* do while (0) to make breaking easy */
2752 n = ssh1_read_bignum
2753 (s->p, s->responselen-(s->p-s->response),
2758 n = ssh1_read_bignum
2759 (s->p, s->responselen-(s->p-s->response),
2764 if (s->responselen - (s->p-s->response) < 4)
2766 s->commentlen = GET_32BIT(s->p);
2768 if (s->responselen - (s->p-s->response) <
2771 s->commentp = (char *)s->p;
2772 s->p += s->commentlen;
2776 logevent("Pageant key list packet was truncated");
2780 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2781 PKT_BIGNUM, s->key.modulus, PKT_END);
2783 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2784 logevent("Key refused");
2787 logevent("Received RSA challenge");
2788 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2789 bombout(("Server's RSA challenge was badly formatted"));
2794 char *agentreq, *q, *ret;
2797 len = 1 + 4; /* message type, bit count */
2798 len += ssh1_bignum_length(s->key.exponent);
2799 len += ssh1_bignum_length(s->key.modulus);
2800 len += ssh1_bignum_length(s->challenge);
2801 len += 16; /* session id */
2802 len += 4; /* response format */
2803 agentreq = snewn(4 + len, char);
2804 PUT_32BIT(agentreq, len);
2806 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2807 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2809 q += ssh1_write_bignum(q, s->key.exponent);
2810 q += ssh1_write_bignum(q, s->key.modulus);
2811 q += ssh1_write_bignum(q, s->challenge);
2812 memcpy(q, s->session_id, 16);
2814 PUT_32BIT(q, 1); /* response format */
2815 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2816 ssh_agent_callback, ssh)) {
2821 bombout(("Unexpected data from server"
2822 " while waiting for agent"
2826 } while (ispkt || inlen > 0);
2827 vret = ssh->agent_response;
2828 retlen = ssh->agent_response_len;
2833 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2834 logevent("Sending Pageant's response");
2835 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2836 PKT_DATA, ret + 5, 16,
2840 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2842 ("Pageant's response accepted");
2843 if (flags & FLAG_VERBOSE) {
2844 c_write_str(ssh, "Authenticated using"
2846 c_write(ssh, s->commentp,
2848 c_write_str(ssh, "\" from agent\r\n");
2853 ("Pageant's response not accepted");
2856 ("Pageant failed to answer challenge");
2860 logevent("No reply received from Pageant");
2863 freebn(s->key.exponent);
2864 freebn(s->key.modulus);
2865 freebn(s->challenge);
2874 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2875 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2877 if (ssh->cfg.try_tis_auth &&
2878 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2879 !s->tis_auth_refused) {
2880 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2881 logevent("Requested TIS authentication");
2882 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2884 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2885 logevent("TIS authentication declined");
2886 if (flags & FLAG_INTERACTIVE)
2887 c_write_str(ssh, "TIS authentication refused.\r\n");
2888 s->tis_auth_refused = 1;
2894 ssh_pkt_getstring(ssh, &challenge, &challengelen);
2896 bombout(("TIS challenge packet was badly formed"));
2899 logevent("Received TIS challenge");
2900 if (challengelen > sizeof(s->prompt) - 1)
2901 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2902 memcpy(s->prompt, challenge, challengelen);
2903 /* Prompt heuristic comes from OpenSSH */
2904 strncpy(s->prompt + challengelen,
2905 memchr(s->prompt, '\n', challengelen) ?
2906 "": "\r\nResponse: ",
2907 (sizeof s->prompt) - challengelen);
2908 s->prompt[(sizeof s->prompt) - 1] = '\0';
2911 if (ssh->cfg.try_tis_auth &&
2912 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2913 !s->ccard_auth_refused) {
2914 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2915 logevent("Requested CryptoCard authentication");
2916 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2918 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2919 logevent("CryptoCard authentication declined");
2920 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2921 s->ccard_auth_refused = 1;
2927 ssh_pkt_getstring(ssh, &challenge, &challengelen);
2929 bombout(("CryptoCard challenge packet was badly formed"));
2932 logevent("Received CryptoCard challenge");
2933 if (challengelen > sizeof(s->prompt) - 1)
2934 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2935 memcpy(s->prompt, challenge, challengelen);
2936 strncpy(s->prompt + challengelen,
2937 memchr(s->prompt, '\n', challengelen) ?
2938 "" : "\r\nResponse: ",
2939 sizeof(s->prompt) - challengelen);
2940 s->prompt[sizeof(s->prompt) - 1] = '\0';
2943 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2944 sprintf(s->prompt, "%.90s@%.90s's password: ",
2945 s->username, ssh->savedhost);
2947 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2948 char *comment = NULL;
2951 if (flags & FLAG_VERBOSE)
2952 c_write_str(ssh, "Trying public key authentication.\r\n");
2953 logeventf(ssh, "Trying public key \"%s\"",
2954 filename_to_str(&ssh->cfg.keyfile));
2955 type = key_type(&ssh->cfg.keyfile);
2956 if (type != SSH_KEYTYPE_SSH1) {
2957 sprintf(msgbuf, "Key is of wrong type (%s)",
2958 key_type_to_str(type));
2960 c_write_str(ssh, msgbuf);
2961 c_write_str(ssh, "\r\n");
2962 s->tried_publickey = 1;
2965 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2966 if (flags & FLAG_VERBOSE)
2967 c_write_str(ssh, "No passphrase required.\r\n");
2970 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2975 * Show password prompt, having first obtained it via a TIS
2976 * or CryptoCard exchange if we're doing TIS or CryptoCard
2980 if (!ssh_get_line(s->prompt, s->password,
2981 sizeof(s->password), TRUE)) {
2983 * get_line failed to get a password (for example
2984 * because one was supplied on the command line
2985 * which has already failed to work). Terminate.
2987 send_packet(ssh, SSH1_MSG_DISCONNECT,
2988 PKT_STR, "No more passwords available to try",
2990 logevent("Unable to authenticate");
2991 connection_fatal(ssh->frontend, "Unable to authenticate");
2992 ssh_closing((Plug)ssh, NULL, 0, 0);
2996 /* Prompt may have come from server. We've munged it a bit, so
2997 * we know it to be zero-terminated at least once. */
2998 int ret; /* need not be saved over crReturn */
2999 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3002 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3004 crWaitUntil(!ispkt);
3005 ret = process_userpass_input(ssh, in, inlen);
3009 c_write_str(ssh, "\r\n");
3013 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3015 * Try public key authentication with the specified
3018 s->tried_publickey = 1;
3021 const char *error = NULL;
3022 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3025 c_write_str(ssh, "Couldn't load private key from ");
3026 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3027 c_write_str(ssh, " (");
3028 c_write_str(ssh, error);
3029 c_write_str(ssh, ").\r\n");
3030 continue; /* go and try password */
3033 c_write_str(ssh, "Wrong passphrase.\r\n");
3034 s->tried_publickey = 0;
3035 continue; /* try again */
3040 * Send a public key attempt.
3042 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3043 PKT_BIGNUM, s->key.modulus, PKT_END);
3046 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3047 c_write_str(ssh, "Server refused our public key.\r\n");
3048 continue; /* go and try password */
3050 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3051 bombout(("Bizarre response to offer of public key"));
3057 unsigned char buffer[32];
3058 Bignum challenge, response;
3060 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3061 bombout(("Server's RSA challenge was badly formatted"));
3064 response = rsadecrypt(challenge, &s->key);
3065 freebn(s->key.private_exponent);/* burn the evidence */
3067 for (i = 0; i < 32; i++) {
3068 buffer[i] = bignum_byte(response, 31 - i);
3072 MD5Update(&md5c, buffer, 32);
3073 MD5Update(&md5c, s->session_id, 16);
3074 MD5Final(buffer, &md5c);
3076 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3077 PKT_DATA, buffer, 16, PKT_END);
3084 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3085 if (flags & FLAG_VERBOSE)
3086 c_write_str(ssh, "Failed to authenticate with"
3087 " our public key.\r\n");
3088 continue; /* go and try password */
3089 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3090 bombout(("Bizarre response to RSA authentication response"));
3094 break; /* we're through! */
3096 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3098 * Defence against traffic analysis: we send a
3099 * whole bunch of packets containing strings of
3100 * different lengths. One of these strings is the
3101 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3102 * The others are all random data in
3103 * SSH1_MSG_IGNORE packets. This way a passive
3104 * listener can't tell which is the password, and
3105 * hence can't deduce the password length.
3107 * Anybody with a password length greater than 16
3108 * bytes is going to have enough entropy in their
3109 * password that a listener won't find it _that_
3110 * much help to know how long it is. So what we'll
3113 * - if password length < 16, we send 15 packets
3114 * containing string lengths 1 through 15
3116 * - otherwise, we let N be the nearest multiple
3117 * of 8 below the password length, and send 8
3118 * packets containing string lengths N through
3119 * N+7. This won't obscure the order of
3120 * magnitude of the password length, but it will
3121 * introduce a bit of extra uncertainty.
3123 * A few servers (the old 1.2.18 through 1.2.22)
3124 * can't deal with SSH1_MSG_IGNORE. For these
3125 * servers, we need an alternative defence. We make
3126 * use of the fact that the password is interpreted
3127 * as a C string: so we can append a NUL, then some
3130 * One server (a Cisco one) can deal with neither
3131 * SSH1_MSG_IGNORE _nor_ a padded password string.
3132 * For this server we are left with no defences
3133 * against password length sniffing.
3135 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3137 * The server can deal with SSH1_MSG_IGNORE, so
3138 * we can use the primary defence.
3140 int bottom, top, pwlen, i;
3143 pwlen = strlen(s->password);
3145 bottom = 0; /* zero length passwords are OK! :-) */
3148 bottom = pwlen & ~7;
3152 assert(pwlen >= bottom && pwlen <= top);
3154 randomstr = snewn(top + 1, char);
3156 for (i = bottom; i <= top; i++) {
3158 defer_packet(ssh, s->pwpkt_type,
3159 PKT_STR, s->password, PKT_END);
3161 for (j = 0; j < i; j++) {
3163 randomstr[j] = random_byte();
3164 } while (randomstr[j] == '\0');
3166 randomstr[i] = '\0';
3167 defer_packet(ssh, SSH1_MSG_IGNORE,
3168 PKT_STR, randomstr, PKT_END);
3171 logevent("Sending password with camouflage packets");
3172 ssh_pkt_defersend(ssh);
3175 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3177 * The server can't deal with SSH1_MSG_IGNORE
3178 * but can deal with padded passwords, so we
3179 * can use the secondary defence.
3185 len = strlen(s->password);
3186 if (len < sizeof(string)) {
3188 strcpy(string, s->password);
3189 len++; /* cover the zero byte */
3190 while (len < sizeof(string)) {
3191 string[len++] = (char) random_byte();
3196 logevent("Sending length-padded password");
3197 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3198 PKT_DATA, ss, len, PKT_END);
3201 * The server has _both_
3202 * BUG_CHOKES_ON_SSH1_IGNORE and
3203 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3204 * therefore nothing we can do.
3207 len = strlen(s->password);
3208 logevent("Sending unpadded password");
3209 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3210 PKT_DATA, s->password, len, PKT_END);
3213 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
3216 logevent("Sent password");
3217 memset(s->password, 0, strlen(s->password));
3219 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3220 if (flags & FLAG_VERBOSE)
3221 c_write_str(ssh, "Access denied\r\n");
3222 logevent("Authentication refused");
3223 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3224 bombout(("Strange packet received, type %d", ssh->pktin.type));
3229 logevent("Authentication successful");
3234 void sshfwd_close(struct ssh_channel *c)
3238 if (ssh->state != SSH_STATE_SESSION) {
3239 assert(ssh->state == SSH_STATE_CLOSED);
3243 if (c && !c->closes) {
3245 * If the channel's remoteid is -1, we have sent
3246 * CHANNEL_OPEN for this channel, but it hasn't even been
3247 * acknowledged by the server. So we must set a close flag
3248 * on it now, and then when the server acks the channel
3249 * open, we can close it then.
3251 if (((int)c->remoteid) != -1) {
3252 if (ssh->version == 1) {
3253 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3256 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3257 ssh2_pkt_adduint32(ssh, c->remoteid);
3261 c->closes = 1; /* sent MSG_CLOSE */
3262 if (c->type == CHAN_X11) {
3264 logevent("Forwarded X11 connection terminated");
3265 } else if (c->type == CHAN_SOCKDATA ||
3266 c->type == CHAN_SOCKDATA_DORMANT) {
3268 logevent("Forwarded port closed");
3273 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3277 if (ssh->state != SSH_STATE_SESSION) {
3278 assert(ssh->state == SSH_STATE_CLOSED);
3282 if (ssh->version == 1) {
3283 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3284 PKT_INT, c->remoteid,
3285 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3287 * In SSH1 we can return 0 here - implying that forwarded
3288 * connections are never individually throttled - because
3289 * the only circumstance that can cause throttling will be
3290 * the whole SSH connection backing up, in which case
3291 * _everything_ will be throttled as a whole.
3295 ssh2_add_channel_data(c, buf, len);
3296 return ssh2_try_send(c);
3300 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3304 if (ssh->state != SSH_STATE_SESSION) {
3305 assert(ssh->state == SSH_STATE_CLOSED);
3309 if (ssh->version == 1) {
3310 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3311 c->v.v1.throttling = 0;
3312 ssh1_throttle(ssh, -1);
3315 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3319 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3321 crBegin(ssh->ssh1_protocol_crstate);
3325 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3328 if (ssh->state == SSH_STATE_CLOSED)
3331 if (ssh->cfg.agentfwd && agent_exists()) {
3332 logevent("Requesting agent forwarding");
3333 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3337 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3338 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3339 bombout(("Protocol confusion"));
3341 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3342 logevent("Agent forwarding refused");
3344 logevent("Agent forwarding enabled");
3345 ssh->agentfwd_enabled = TRUE;
3349 if (ssh->cfg.x11_forward) {
3350 char proto[20], data[64];
3351 logevent("Requesting X11 forwarding");
3352 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3353 data, sizeof(data), ssh->cfg.x11_auth);
3354 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3355 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3356 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3357 PKT_STR, proto, PKT_STR, data,
3358 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3361 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3362 PKT_STR, proto, PKT_STR, data, PKT_END);
3367 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3368 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3369 bombout(("Protocol confusion"));
3371 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3372 logevent("X11 forwarding refused");
3374 logevent("X11 forwarding enabled");
3375 ssh->X11_fwd_enabled = TRUE;
3382 int sport,dport,sserv,dserv;
3383 char sports[256], dports[256], saddr[256], host[256];
3385 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3386 /* Add port forwardings. */
3387 ssh->portfwd_strptr = ssh->cfg.portfwd;
3388 while (*ssh->portfwd_strptr) {
3389 type = *ssh->portfwd_strptr++;
3392 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3393 if (*ssh->portfwd_strptr == ':') {
3395 * We've seen a colon in the middle of the
3396 * source port number. This means that
3397 * everything we've seen until now is the
3398 * source _address_, so we'll move it into
3399 * saddr and start sports from the beginning
3402 ssh->portfwd_strptr++;
3404 strcpy(saddr, sports);
3407 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3411 if (*ssh->portfwd_strptr == '\t')
3412 ssh->portfwd_strptr++;
3414 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3415 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3418 if (*ssh->portfwd_strptr == ':')
3419 ssh->portfwd_strptr++;
3421 while (*ssh->portfwd_strptr) {
3422 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3425 ssh->portfwd_strptr++;
3426 dport = atoi(dports);
3430 dport = net_service_lookup(dports);
3432 logeventf(ssh, "Service lookup failed for"
3433 " destination port \"%s\"", dports);
3437 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3439 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3441 sport = atoi(sports);
3445 sport = net_service_lookup(sports);
3447 logeventf(ssh, "Service lookup failed for source"
3448 " port \"%s\"", sports);
3451 if (sport && dport) {
3453 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3454 sport, ssh, &ssh->cfg);
3455 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3456 " forwarding to %s:%.*s%.*s%d%.*s",
3457 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3458 (int)(*saddr?1:0), ":",
3459 (int)(sserv ? strlen(sports) : 0), sports,
3460 sserv, "(", sport, sserv, ")",
3462 (int)(dserv ? strlen(dports) : 0), dports,
3463 dserv, "(", dport, dserv, ")");
3464 } else if (type == 'D') {
3465 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3466 sport, ssh, &ssh->cfg);
3467 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3468 " doing SOCKS dynamic forwarding",
3469 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3470 (int)(*saddr?1:0), ":",
3471 (int)(sserv ? strlen(sports) : 0), sports,
3472 sserv, "(", sport, sserv, ")");
3474 struct ssh_rportfwd *pf;
3475 pf = snew(struct ssh_rportfwd);
3476 strcpy(pf->dhost, host);
3480 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3483 if (add234(ssh->rportfwds, pf) != pf) {
3485 "Duplicate remote port forwarding to %s:%d",
3489 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3490 " forward to %s:%.*s%.*s%d%.*s",
3491 (int)(sserv ? strlen(sports) : 0), sports,
3492 sserv, "(", sport, sserv, ")",
3494 (int)(dserv ? strlen(dports) : 0), dports,
3495 dserv, "(", dport, dserv, ")");
3496 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3504 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3505 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3506 bombout(("Protocol confusion"));
3508 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3509 c_write_str(ssh, "Server refused port"
3512 logevent("Remote port forwarding enabled");
3519 if (!ssh->cfg.nopty) {
3520 /* Unpick the terminal-speed string. */
3521 /* XXX perhaps we should allow no speeds to be sent. */
3522 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3523 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
3524 /* Send the pty request. */
3525 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3526 PKT_STR, ssh->cfg.termtype,
3527 PKT_INT, ssh->term_height,
3528 PKT_INT, ssh->term_width,
3529 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
3530 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3531 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
3532 PKT_CHAR, 0, PKT_END);
3533 ssh->state = SSH_STATE_INTERMED;
3537 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3538 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3539 bombout(("Protocol confusion"));
3541 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3542 c_write_str(ssh, "Server refused to allocate pty\r\n");
3543 ssh->editing = ssh->echoing = 1;
3545 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
3546 ssh->ospeed, ssh->ispeed);
3548 ssh->editing = ssh->echoing = 1;
3551 if (ssh->cfg.compression) {
3552 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3556 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3557 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3558 bombout(("Protocol confusion"));
3560 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3561 c_write_str(ssh, "Server refused to compress\r\n");
3563 logevent("Started compression");
3564 ssh->v1_compressing = TRUE;
3565 ssh->cs_comp_ctx = zlib_compress_init();
3566 logevent("Initialised zlib (RFC1950) compression");
3567 ssh->sc_comp_ctx = zlib_decompress_init();
3568 logevent("Initialised zlib (RFC1950) decompression");
3572 * Start the shell or command.
3574 * Special case: if the first-choice command is an SSH2
3575 * subsystem (hence not usable here) and the second choice
3576 * exists, we fall straight back to that.
3579 char *cmd = ssh->cfg.remote_cmd_ptr;
3581 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3582 cmd = ssh->cfg.remote_cmd_ptr2;
3583 ssh->fallback_cmd = TRUE;
3586 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3588 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3589 logevent("Started session");
3592 ssh->state = SSH_STATE_SESSION;
3593 if (ssh->size_needed)
3594 ssh_size(ssh, ssh->term_width, ssh->term_height);
3595 if (ssh->eof_needed)
3596 ssh_special(ssh, TS_EOF);
3599 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3601 ssh->channels = newtree234(ssh_channelcmp);
3605 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3606 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3608 int stringlen, bufsize;
3610 ssh_pkt_getstring(ssh, &string, &stringlen);
3611 if (string == NULL) {
3612 bombout(("Incoming terminal data packet was badly formed"));
3617 from_backend(ssh->frontend,
3618 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3620 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3621 ssh->v1_stdout_throttling = 1;
3622 ssh1_throttle(ssh, +1);
3624 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3625 ssh_closing((Plug)ssh, NULL, 0, 0);
3626 logevent("Received disconnect request");
3628 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3629 /* Remote side is trying to open a channel to talk to our
3630 * X-Server. Give them back a local channel number. */
3631 struct ssh_channel *c;
3632 int remoteid = ssh_pkt_getuint32(ssh);
3634 logevent("Received X11 connect request");
3635 /* Refuse if X11 forwarding is disabled. */
3636 if (!ssh->X11_fwd_enabled) {
3637 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3638 PKT_INT, remoteid, PKT_END);
3639 logevent("Rejected X11 connect request");
3641 c = snew(struct ssh_channel);
3644 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3645 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3646 logevent("Opening X11 forward connection failed");
3648 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3649 PKT_INT, remoteid, PKT_END);
3652 ("Opening X11 forward connection succeeded");
3653 c->remoteid = remoteid;
3654 c->localid = alloc_channel_id(ssh);
3656 c->v.v1.throttling = 0;
3657 c->type = CHAN_X11; /* identify channel type */
3658 add234(ssh->channels, c);
3659 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3660 PKT_INT, c->remoteid, PKT_INT,
3661 c->localid, PKT_END);
3662 logevent("Opened X11 forward channel");
3665 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3666 /* Remote side is trying to open a channel to talk to our
3667 * agent. Give them back a local channel number. */
3668 struct ssh_channel *c;
3669 int remoteid = ssh_pkt_getuint32(ssh);
3671 /* Refuse if agent forwarding is disabled. */
3672 if (!ssh->agentfwd_enabled) {
3673 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3674 PKT_INT, remoteid, PKT_END);
3676 c = snew(struct ssh_channel);
3678 c->remoteid = remoteid;
3679 c->localid = alloc_channel_id(ssh);
3681 c->v.v1.throttling = 0;
3682 c->type = CHAN_AGENT; /* identify channel type */
3683 c->u.a.lensofar = 0;
3684 add234(ssh->channels, c);
3685 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3686 PKT_INT, c->remoteid, PKT_INT, c->localid,
3689 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3690 /* Remote side is trying to open a channel to talk to a
3691 * forwarded port. Give them back a local channel number. */
3692 struct ssh_channel *c;
3693 struct ssh_rportfwd pf;
3696 char *host, buf[1024];
3698 c = snew(struct ssh_channel);
3701 remoteid = ssh_pkt_getuint32(ssh);
3702 ssh_pkt_getstring(ssh, &host, &hostsize);
3703 port = ssh_pkt_getuint32(ssh);
3705 if (hostsize >= lenof(pf.dhost))
3706 hostsize = lenof(pf.dhost)-1;
3707 memcpy(pf.dhost, host, hostsize);
3708 pf.dhost[hostsize] = '\0';
3711 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3712 sprintf(buf, "Rejected remote port open request for %s:%d",
3715 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3716 PKT_INT, remoteid, PKT_END);
3718 sprintf(buf, "Received remote port open request for %s:%d",
3721 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3725 sprintf(buf, "Port open failed: %s", e);
3728 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3729 PKT_INT, remoteid, PKT_END);
3731 c->remoteid = remoteid;
3732 c->localid = alloc_channel_id(ssh);
3734 c->v.v1.throttling = 0;
3735 c->type = CHAN_SOCKDATA; /* identify channel type */
3736 add234(ssh->channels, c);
3737 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3738 PKT_INT, c->remoteid, PKT_INT,
3739 c->localid, PKT_END);
3740 logevent("Forwarded port opened successfully");
3744 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3745 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3746 unsigned int localid = ssh_pkt_getuint32(ssh);
3747 struct ssh_channel *c;
3749 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3750 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3751 c->remoteid = localid;
3752 c->type = CHAN_SOCKDATA;
3753 c->v.v1.throttling = 0;
3754 pfd_confirm(c->u.pfd.s);
3757 if (c && c->closes) {
3759 * We have a pending close on this channel,
3760 * which we decided on before the server acked
3761 * the channel open. So now we know the
3762 * remoteid, we can close it again.
3764 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3765 PKT_INT, c->remoteid, PKT_END);
3768 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3769 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3770 struct ssh_channel *c;
3772 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3773 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3774 logevent("Forwarded connection refused by server");
3775 pfd_close(c->u.pfd.s);
3776 del234(ssh->channels, c);
3780 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3781 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3782 /* Remote side closes a channel. */
3783 unsigned i = ssh_pkt_getuint32(ssh);
3784 struct ssh_channel *c;
3785 c = find234(ssh->channels, &i, ssh_channelfind);
3786 if (c && ((int)c->remoteid) != -1) {
3789 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3791 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3792 logevent("Forwarded X11 connection terminated");
3793 assert(c->u.x11.s != NULL);
3794 x11_close(c->u.x11.s);
3797 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3798 logevent("Forwarded port closed");
3799 assert(c->u.pfd.s != NULL);
3800 pfd_close(c->u.pfd.s);
3804 c->closes |= (closetype << 2); /* seen this message */
3805 if (!(c->closes & closetype)) {
3806 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3808 c->closes |= closetype; /* sent it too */
3811 if (c->closes == 15) {
3812 del234(ssh->channels, c);
3816 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3817 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3818 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3822 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3823 /* Data sent down one of our channels. */
3824 int i = ssh_pkt_getuint32(ssh);
3827 struct ssh_channel *c;
3829 ssh_pkt_getstring(ssh, &p, &len);
3831 c = find234(ssh->channels, &i, ssh_channelfind);
3836 bufsize = x11_send(c->u.x11.s, p, len);
3839 bufsize = pfd_send(c->u.pfd.s, p, len);
3842 /* Data for an agent message. Buffer it. */
3844 if (c->u.a.lensofar < 4) {
3845 int l = min(4 - c->u.a.lensofar, len);
3846 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3850 c->u.a.lensofar += l;
3852 if (c->u.a.lensofar == 4) {
3854 4 + GET_32BIT(c->u.a.msglen);
3855 c->u.a.message = snewn(c->u.a.totallen,
3857 memcpy(c->u.a.message, c->u.a.msglen, 4);
3859 if (c->u.a.lensofar >= 4 && len > 0) {
3861 min(c->u.a.totallen - c->u.a.lensofar,
3863 memcpy(c->u.a.message + c->u.a.lensofar, p,
3867 c->u.a.lensofar += l;
3869 if (c->u.a.lensofar == c->u.a.totallen) {
3872 if (agent_query(c->u.a.message,
3875 ssh_agentf_callback, c))
3876 ssh_agentf_callback(c, reply, replylen);
3877 sfree(c->u.a.message);
3878 c->u.a.lensofar = 0;
3881 bufsize = 0; /* agent channels never back up */
3884 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3885 c->v.v1.throttling = 1;
3886 ssh1_throttle(ssh, +1);
3889 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3890 /* may be from EXEC_SHELL on some servers */
3891 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3892 /* may be from EXEC_SHELL on some servers
3893 * if no pty is available or in other odd cases. Ignore */
3894 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3896 ssh->exitcode = ssh_pkt_getuint32(ssh);
3897 sprintf(buf, "Server sent command exit status %d",
3900 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3902 * In case `helpful' firewalls or proxies tack
3903 * extra human-readable text on the end of the
3904 * session which we might mistake for another
3905 * encrypted packet, we close the session once
3906 * we've sent EXIT_CONFIRMATION.
3908 ssh_closing((Plug)ssh, NULL, 0, 0);
3911 bombout(("Strange packet received: type %d", ssh->pktin.type));
3916 int len = min(inlen, 512);
3917 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3918 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3929 * Utility routine for decoding comma-separated strings in KEXINIT.
3931 static int in_commasep_string(char *needle, char *haystack, int haylen)
3934 if (!needle || !haystack) /* protect against null pointers */
3936 needlen = strlen(needle);
3939 * Is it at the start of the string?
3941 if (haylen >= needlen && /* haystack is long enough */
3942 !memcmp(needle, haystack, needlen) && /* initial match */
3943 (haylen == needlen || haystack[needlen] == ',')
3944 /* either , or EOS follows */
3948 * If not, search for the next comma and resume after that.
3949 * If no comma found, terminate.
3951 while (haylen > 0 && *haystack != ',')
3952 haylen--, haystack++;
3955 haylen--, haystack++; /* skip over comma itself */
3960 * SSH2 key creation method.
3962 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3963 unsigned char *sessid, char chr,
3964 unsigned char *keyspace)
3967 /* First 20 bytes. */
3969 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3971 SHA_Bytes(&s, H, 20);
3972 SHA_Bytes(&s, &chr, 1);
3973 SHA_Bytes(&s, sessid, 20);
3974 SHA_Final(&s, keyspace);
3975 /* Next 20 bytes. */
3977 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3979 SHA_Bytes(&s, H, 20);
3980 SHA_Bytes(&s, keyspace, 20);
3981 SHA_Final(&s, keyspace + 20);
3985 * Handle the SSH2 transport layer.
3987 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3989 struct do_ssh2_transport_state {
3990 int nbits, pbits, warn;
3991 Bignum p, g, e, f, K;
3992 int kex_init_value, kex_reply_value;
3993 const struct ssh_mac **maclist;
3995 const struct ssh2_cipher *cscipher_tobe;
3996 const struct ssh2_cipher *sccipher_tobe;
3997 const struct ssh_mac *csmac_tobe;
3998 const struct ssh_mac *scmac_tobe;
3999 const struct ssh_compress *cscomp_tobe;
4000 const struct ssh_compress *sccomp_tobe;
4001 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4002 int hostkeylen, siglen;
4003 void *hkey; /* actual host key */
4004 unsigned char exchange_hash[20];
4005 int n_preferred_ciphers;
4006 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4007 const struct ssh_compress *preferred_comp;
4010 crState(do_ssh2_transport_state);
4012 crBegin(ssh->do_ssh2_transport_crstate);
4014 s->cscipher_tobe = s->sccipher_tobe = NULL;
4015 s->csmac_tobe = s->scmac_tobe = NULL;
4016 s->cscomp_tobe = s->sccomp_tobe = NULL;
4024 * Set up the preferred ciphers. (NULL => warn below here)
4026 s->n_preferred_ciphers = 0;
4027 for (i = 0; i < CIPHER_MAX; i++) {
4028 switch (ssh->cfg.ssh_cipherlist[i]) {
4029 case CIPHER_BLOWFISH:
4030 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4033 if (ssh->cfg.ssh2_des_cbc) {
4034 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4038 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4041 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4044 /* Flag for later. Don't bother if it's the last in
4046 if (i < CIPHER_MAX - 1) {
4047 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4055 * Set up preferred compression.
4057 if (ssh->cfg.compression)
4058 s->preferred_comp = &ssh_zlib;
4060 s->preferred_comp = &ssh_comp_none;
4063 * Be prepared to work around the buggy MAC problem.
4065 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4066 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4068 s->maclist = macs, s->nmacs = lenof(macs);
4072 int i, j, cipherstr_started;
4075 * Construct and send our key exchange packet.
4077 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4078 for (i = 0; i < 16; i++)
4079 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4080 /* List key exchange algorithms. */
4081 ssh2_pkt_addstring_start(ssh);
4082 for (i = 0; i < lenof(kex_algs); i++) {
4083 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4084 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4086 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4087 if (i < lenof(kex_algs) - 1)
4088 ssh2_pkt_addstring_str(ssh, ",");
4090 /* List server host key algorithms. */
4091 ssh2_pkt_addstring_start(ssh);
4092 for (i = 0; i < lenof(hostkey_algs); i++) {
4093 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4094 if (i < lenof(hostkey_algs) - 1)
4095 ssh2_pkt_addstring_str(ssh, ",");
4097 /* List client->server encryption algorithms. */
4098 ssh2_pkt_addstring_start(ssh);
4099 cipherstr_started = 0;
4100 for (i = 0; i < s->n_preferred_ciphers; i++) {
4101 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4102 if (!c) continue; /* warning flag */
4103 for (j = 0; j < c->nciphers; j++) {
4104 if (cipherstr_started)
4105 ssh2_pkt_addstring_str(ssh, ",");
4106 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4107 cipherstr_started = 1;
4110 /* List server->client encryption algorithms. */
4111 ssh2_pkt_addstring_start(ssh);
4112 cipherstr_started = 0;
4113 for (i = 0; i < s->n_preferred_ciphers; i++) {
4114 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4115 if (!c) continue; /* warning flag */
4116 for (j = 0; j < c->nciphers; j++) {
4117 if (cipherstr_started)
4118 ssh2_pkt_addstring_str(ssh, ",");
4119 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4120 cipherstr_started = 1;
4123 /* List client->server MAC algorithms. */
4124 ssh2_pkt_addstring_start(ssh);
4125 for (i = 0; i < s->nmacs; i++) {
4126 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4127 if (i < s->nmacs - 1)
4128 ssh2_pkt_addstring_str(ssh, ",");
4130 /* List server->client MAC algorithms. */
4131 ssh2_pkt_addstring_start(ssh);
4132 for (i = 0; i < s->nmacs; i++) {
4133 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4134 if (i < s->nmacs - 1)
4135 ssh2_pkt_addstring_str(ssh, ",");
4137 /* List client->server compression algorithms. */
4138 ssh2_pkt_addstring_start(ssh);
4139 for (i = 0; i < lenof(compressions) + 1; i++) {
4140 const struct ssh_compress *c =
4141 i == 0 ? s->preferred_comp : compressions[i - 1];
4142 ssh2_pkt_addstring_str(ssh, c->name);
4143 if (i < lenof(compressions))
4144 ssh2_pkt_addstring_str(ssh, ",");
4146 /* List server->client compression algorithms. */
4147 ssh2_pkt_addstring_start(ssh);
4148 for (i = 0; i < lenof(compressions) + 1; i++) {
4149 const struct ssh_compress *c =
4150 i == 0 ? s->preferred_comp : compressions[i - 1];
4151 ssh2_pkt_addstring_str(ssh, c->name);
4152 if (i < lenof(compressions))
4153 ssh2_pkt_addstring_str(ssh, ",");
4155 /* List client->server languages. Empty list. */
4156 ssh2_pkt_addstring_start(ssh);
4157 /* List server->client languages. Empty list. */
4158 ssh2_pkt_addstring_start(ssh);
4159 /* First KEX packet does _not_ follow, because we're not that brave. */
4160 ssh2_pkt_addbool(ssh, FALSE);
4162 ssh2_pkt_adduint32(ssh, 0);
4165 ssh->exhash = ssh->exhashbase;
4166 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4172 if (ssh->pktin.length > 5)
4173 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4176 * Now examine the other side's KEXINIT to see what we're up
4183 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4184 bombout(("expected key exchange packet from server"));
4188 ssh->hostkey = NULL;
4189 s->cscipher_tobe = NULL;
4190 s->sccipher_tobe = NULL;
4191 s->csmac_tobe = NULL;
4192 s->scmac_tobe = NULL;
4193 s->cscomp_tobe = NULL;
4194 s->sccomp_tobe = NULL;
4195 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4196 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4197 for (i = 0; i < lenof(kex_algs); i++) {
4198 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4199 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4201 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4202 ssh->kex = kex_algs[i];
4206 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4207 for (i = 0; i < lenof(hostkey_algs); i++) {
4208 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4209 ssh->hostkey = hostkey_algs[i];
4213 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4215 for (i = 0; i < s->n_preferred_ciphers; i++) {
4216 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4220 for (j = 0; j < c->nciphers; j++) {
4221 if (in_commasep_string(c->list[j]->name, str, len)) {
4222 s->cscipher_tobe = c->list[j];
4227 if (s->cscipher_tobe) {
4229 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4233 if (!s->cscipher_tobe) {
4234 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4235 str ? str : "(null)"));
4239 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4241 for (i = 0; i < s->n_preferred_ciphers; i++) {
4242 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4246 for (j = 0; j < c->nciphers; j++) {
4247 if (in_commasep_string(c->list[j]->name, str, len)) {
4248 s->sccipher_tobe = c->list[j];
4253 if (s->sccipher_tobe) {
4255 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4259 if (!s->sccipher_tobe) {
4260 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4261 str ? str : "(null)"));
4265 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
4266 for (i = 0; i < s->nmacs; i++) {
4267 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4268 s->csmac_tobe = s->maclist[i];
4272 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
4273 for (i = 0; i < s->nmacs; i++) {
4274 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4275 s->scmac_tobe = s->maclist[i];
4279 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
4280 for (i = 0; i < lenof(compressions) + 1; i++) {
4281 const struct ssh_compress *c =
4282 i == 0 ? s->preferred_comp : compressions[i - 1];
4283 if (in_commasep_string(c->name, str, len)) {
4288 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
4289 for (i = 0; i < lenof(compressions) + 1; i++) {
4290 const struct ssh_compress *c =
4291 i == 0 ? s->preferred_comp : compressions[i - 1];
4292 if (in_commasep_string(c->name, str, len)) {
4300 * Work out the number of bits of key we will need from the key
4301 * exchange. We start with the maximum key length of either
4307 csbits = s->cscipher_tobe->keylen;
4308 scbits = s->sccipher_tobe->keylen;
4309 s->nbits = (csbits > scbits ? csbits : scbits);
4311 /* The keys only have 160-bit entropy, since they're based on
4312 * a SHA-1 hash. So cap the key size at 160 bits. */
4317 * If we're doing Diffie-Hellman group exchange, start by
4318 * requesting a group.
4320 if (ssh->kex == &ssh_diffiehellman_gex) {
4321 logevent("Doing Diffie-Hellman group exchange");
4322 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4324 * Work out how big a DH group we will need to allow that
4327 s->pbits = 512 << ((s->nbits - 1) / 64);
4328 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4329 ssh2_pkt_adduint32(ssh, s->pbits);
4333 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4334 bombout(("expected key exchange group packet from server"));
4337 s->p = ssh2_pkt_getmp(ssh);
4338 s->g = ssh2_pkt_getmp(ssh);
4339 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4340 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4341 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4343 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4344 ssh->kex_ctx = dh_setup_group1();
4345 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4346 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4349 logevent("Doing Diffie-Hellman key exchange");
4351 * Now generate and send e for Diffie-Hellman.
4353 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4354 ssh2_pkt_init(ssh, s->kex_init_value);
4355 ssh2_pkt_addmp(ssh, s->e);
4359 if (ssh->pktin.type != s->kex_reply_value) {
4360 bombout(("expected key exchange reply packet from server"));
4363 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4364 s->f = ssh2_pkt_getmp(ssh);
4365 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4367 s->K = dh_find_K(ssh->kex_ctx, s->f);
4369 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4370 if (ssh->kex == &ssh_diffiehellman_gex) {
4371 sha_uint32(&ssh->exhash, s->pbits);
4372 sha_mpint(&ssh->exhash, s->p);
4373 sha_mpint(&ssh->exhash, s->g);
4375 sha_mpint(&ssh->exhash, s->e);
4376 sha_mpint(&ssh->exhash, s->f);
4377 sha_mpint(&ssh->exhash, s->K);
4378 SHA_Final(&ssh->exhash, s->exchange_hash);
4380 dh_cleanup(ssh->kex_ctx);
4381 ssh->kex_ctx = NULL;
4384 debug(("Exchange hash is:\n"));
4385 dmemdump(s->exchange_hash, 20);
4388 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4390 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4391 (char *)s->exchange_hash, 20)) {
4392 bombout(("Server's host key did not match the signature supplied"));
4397 * Authenticate remote host: verify host key. (We've already
4398 * checked the signature of the exchange hash.)
4400 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4401 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4402 verify_ssh_host_key(ssh->frontend,
4403 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4404 s->keystr, s->fingerprint);
4405 if (s->first_kex) { /* don't bother logging this in rekeys */
4406 logevent("Host key fingerprint is:");
4407 logevent(s->fingerprint);
4409 sfree(s->fingerprint);
4411 ssh->hostkey->freekey(s->hkey);
4414 * Send SSH2_MSG_NEWKEYS.
4416 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4420 * Expect SSH2_MSG_NEWKEYS from server.
4423 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4424 bombout(("expected new-keys packet from server"));
4429 * Create and initialise session keys.
4431 if (ssh->cs_cipher_ctx)
4432 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4433 ssh->cscipher = s->cscipher_tobe;
4434 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4436 if (ssh->sc_cipher_ctx)
4437 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4438 ssh->sccipher = s->sccipher_tobe;
4439 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4441 if (ssh->cs_mac_ctx)
4442 ssh->csmac->free_context(ssh->cs_mac_ctx);
4443 ssh->csmac = s->csmac_tobe;
4444 ssh->cs_mac_ctx = ssh->csmac->make_context();
4446 if (ssh->sc_mac_ctx)
4447 ssh->scmac->free_context(ssh->sc_mac_ctx);
4448 ssh->scmac = s->scmac_tobe;
4449 ssh->sc_mac_ctx = ssh->scmac->make_context();
4451 if (ssh->cs_comp_ctx)
4452 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4453 ssh->cscomp = s->cscomp_tobe;
4454 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4456 if (ssh->sc_comp_ctx)
4457 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4458 ssh->sccomp = s->sccomp_tobe;
4459 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4462 * Set IVs after keys. Here we use the exchange hash from the
4463 * _first_ key exchange.
4466 unsigned char keyspace[40];
4468 memcpy(ssh->v2_session_id, s->exchange_hash,
4469 sizeof(s->exchange_hash));
4470 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4471 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4472 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4473 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4474 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4475 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4476 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4477 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4478 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4479 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4480 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4481 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4483 logeventf(ssh, "Initialised %.200s client->server encryption",
4484 ssh->cscipher->text_name);
4485 logeventf(ssh, "Initialised %.200s server->client encryption",
4486 ssh->sccipher->text_name);
4487 if (ssh->cscomp->text_name)
4488 logeventf(ssh, "Initialised %s compression",
4489 ssh->cscomp->text_name);
4490 if (ssh->sccomp->text_name)
4491 logeventf(ssh, "Initialised %s decompression",
4492 ssh->sccomp->text_name);
4495 if (ssh->kex == &ssh_diffiehellman_gex) {
4501 * If this is the first key exchange phase, we must pass the
4502 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4503 * wants to see it but because it will need time to initialise
4504 * itself before it sees an actual packet. In subsequent key
4505 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4506 * it would only confuse the layer above.
4508 if (!s->first_kex) {
4514 * Now we're encrypting. Begin returning 1 to the protocol main
4515 * function so that other things can run on top of the
4516 * transport. If we ever see a KEXINIT, we must go back to the
4519 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4522 logevent("Server initiated key re-exchange");
4523 goto begin_key_exchange;
4529 * Add data to an SSH2 channel output buffer.
4531 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4534 bufchain_add(&c->v.v2.outbuffer, buf, len);
4538 * Attempt to send data on an SSH2 channel.
4540 static int ssh2_try_send(struct ssh_channel *c)
4544 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4547 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4548 if ((unsigned)len > c->v.v2.remwindow)
4549 len = c->v.v2.remwindow;
4550 if ((unsigned)len > c->v.v2.remmaxpkt)
4551 len = c->v.v2.remmaxpkt;
4552 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4553 ssh2_pkt_adduint32(ssh, c->remoteid);
4554 ssh2_pkt_addstring_start(ssh);
4555 ssh2_pkt_addstring_data(ssh, data, len);
4557 bufchain_consume(&c->v.v2.outbuffer, len);
4558 c->v.v2.remwindow -= len;
4562 * After having sent as much data as we can, return the amount
4565 return bufchain_size(&c->v.v2.outbuffer);
4569 * Potentially enlarge the window on an SSH2 channel.
4571 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4576 * Never send WINDOW_ADJUST for a channel that the remote side
4577 * already thinks it's closed; there's no point, since it won't
4578 * be sending any more data anyway.
4583 if (newwin > c->v.v2.locwindow) {
4584 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4585 ssh2_pkt_adduint32(ssh, c->remoteid);
4586 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4588 c->v.v2.locwindow = newwin;
4593 * Handle the SSH2 userauth and connection layers.
4595 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4597 struct do_ssh2_authconn_state {
4599 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4601 AUTH_KEYBOARD_INTERACTIVE
4605 AUTH_TYPE_PUBLICKEY,
4606 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4607 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4609 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4610 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4612 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4613 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4614 int kbd_inter_running;
4616 int num_prompts, curr_prompt, echo;
4621 void *publickey_blob;
4622 int publickey_bloblen;
4623 unsigned char request[5], *response, *p;
4627 char *pkblob, *alg, *commentp;
4628 int pklen, alglen, commentlen;
4629 int siglen, retlen, len;
4630 char *q, *agentreq, *ret;
4633 crState(do_ssh2_authconn_state);
4635 crBegin(ssh->do_ssh2_authconn_crstate);
4638 * Request userauth protocol, and await a response to it.
4640 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4641 ssh2_pkt_addstring(ssh, "ssh-userauth");
4643 crWaitUntilV(ispkt);
4644 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4645 bombout(("Server refused user authentication protocol"));
4650 * We repeat this whole loop, including the username prompt,
4651 * until we manage a successful authentication. If the user
4652 * types the wrong _password_, they can be sent back to the
4653 * beginning to try another username, if this is configured on.
4654 * (If they specify a username in the config, they are never
4655 * asked, even if they do give a wrong password.)
4657 * I think this best serves the needs of
4659 * - the people who have no configuration, no keys, and just
4660 * want to try repeated (username,password) pairs until they
4661 * type both correctly
4663 * - people who have keys and configuration but occasionally
4664 * need to fall back to passwords
4666 * - people with a key held in Pageant, who might not have
4667 * logged in to a particular machine before; so they want to
4668 * type a username, and then _either_ their key will be
4669 * accepted, _or_ they will type a password. If they mistype
4670 * the username they will want to be able to get back and
4673 s->username[0] = '\0';
4674 s->got_username = FALSE;
4679 if (s->got_username && !ssh->cfg.change_username) {
4681 * We got a username last time round this loop, and
4682 * with change_username turned off we don't try to get
4685 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4686 if (ssh_get_line && !ssh_getline_pw_only) {
4687 if (!ssh_get_line("login as: ",
4688 s->username, sizeof(s->username), FALSE)) {
4690 * get_line failed to get a username.
4693 logevent("No username provided. Abandoning session.");
4694 ssh_closing((Plug)ssh, NULL, 0, 0);
4698 int ret; /* need not be saved across crReturn */
4699 c_write_str(ssh, "login as: ");
4701 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4703 crWaitUntilV(!ispkt);
4704 ret = process_userpass_input(ssh, in, inlen);
4708 c_write_str(ssh, "\r\n");
4710 s->username[strcspn(s->username, "\n\r")] = '\0';
4713 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4714 s->username[sizeof(s->username)-1] = '\0';
4715 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4716 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4717 c_write_str(ssh, stuff);
4721 s->got_username = TRUE;
4724 * Send an authentication request using method "none": (a)
4725 * just in case it succeeds, and (b) so that we know what
4726 * authentication methods we can usefully try next.
4728 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4730 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4731 ssh2_pkt_addstring(ssh, s->username);
4732 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4733 ssh2_pkt_addstring(ssh, "none"); /* method */
4735 s->type = AUTH_TYPE_NONE;
4737 s->we_are_in = FALSE;
4739 s->tried_pubkey_config = FALSE;
4740 s->tried_agent = FALSE;
4741 s->tried_keyb_inter = FALSE;
4742 s->kbd_inter_running = FALSE;
4743 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4744 if (!filename_is_null(ssh->cfg.keyfile)) {
4746 logeventf(ssh, "Reading private key file \"%.150s\"",
4747 filename_to_str(&ssh->cfg.keyfile));
4748 keytype = key_type(&ssh->cfg.keyfile);
4749 if (keytype == SSH_KEYTYPE_SSH2) {
4751 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4752 &s->publickey_bloblen, NULL);
4755 logeventf(ssh, "Unable to use this key file (%s)",
4756 key_type_to_str(keytype));
4757 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4759 filename_to_str(&ssh->cfg.keyfile),
4760 key_type_to_str(keytype));
4761 c_write_str(ssh, msgbuf);
4763 s->publickey_blob = NULL;
4766 s->publickey_blob = NULL;
4770 * Wait for the result of the last authentication request.
4773 crWaitUntilV(ispkt);
4774 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4778 * Don't show the banner if we're operating in
4779 * non-verbose non-interactive mode. (It's probably
4780 * a script, which means nobody will read the
4781 * banner _anyway_, and moreover the printing of
4782 * the banner will screw up processing on the
4783 * output of (say) plink.)
4785 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4786 ssh_pkt_getstring(ssh, &banner, &size);
4788 c_write_untrusted(ssh, banner, size);
4790 crWaitUntilV(ispkt);
4792 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4793 logevent("Access granted");
4794 s->we_are_in = TRUE;
4798 if (s->kbd_inter_running &&
4799 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4801 * This is either a further set-of-prompts packet
4802 * in keyboard-interactive authentication, or it's
4803 * the same one and we came back here with `gotit'
4804 * set. In the former case, we must reset the
4805 * curr_prompt variable.
4809 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4810 bombout(("Strange packet received during authentication: type %d",
4818 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4819 * we can look at the string in it and know what we can
4820 * helpfully try next.
4822 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4825 ssh_pkt_getstring(ssh, &methods, &methlen);
4826 s->kbd_inter_running = FALSE;
4827 if (!ssh2_pkt_getbool(ssh)) {
4829 * We have received an unequivocal Access
4830 * Denied. This can translate to a variety of
4833 * - if we'd just tried "none" authentication,
4834 * it's not worth printing anything at all
4836 * - if we'd just tried a public key _offer_,
4837 * the message should be "Server refused our
4838 * key" (or no message at all if the key
4839 * came from Pageant)
4841 * - if we'd just tried anything else, the
4842 * message really should be "Access denied".
4844 * Additionally, if we'd just tried password
4845 * authentication, we should break out of this
4846 * whole loop so as to go back to the username
4849 if (s->type == AUTH_TYPE_NONE) {
4851 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4852 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4853 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4854 c_write_str(ssh, "Server refused our key\r\n");
4855 logevent("Server refused public key");
4856 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4857 /* server declined keyboard-interactive; ignore */
4859 c_write_str(ssh, "Access denied\r\n");
4860 logevent("Access denied");
4861 if (s->type == AUTH_TYPE_PASSWORD) {
4862 s->we_are_in = FALSE;
4867 c_write_str(ssh, "Further authentication required\r\n");
4868 logevent("Further authentication required");
4872 in_commasep_string("publickey", methods, methlen);
4874 in_commasep_string("password", methods, methlen);
4875 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4876 in_commasep_string("keyboard-interactive", methods, methlen);
4880 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4884 * Most password/passphrase prompts will be
4885 * non-echoing, so we set this to 0 by default.
4886 * Exception is that some keyboard-interactive prompts
4887 * can be echoing, in which case we'll set this to 1.
4891 if (!s->method && s->can_pubkey &&
4892 agent_exists() && !s->tried_agent) {
4894 * Attempt public-key authentication using Pageant.
4899 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4900 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4902 s->tried_agent = TRUE;
4904 logevent("Pageant is running. Requesting keys.");
4906 /* Request the keys held by the agent. */
4907 PUT_32BIT(s->request, 1);
4908 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4909 if (!agent_query(s->request, 5, &r, &s->responselen,
4910 ssh_agent_callback, ssh)) {
4914 bombout(("Unexpected data from server while"
4915 " waiting for agent response"));
4918 } while (ispkt || inlen > 0);
4919 r = ssh->agent_response;
4920 s->responselen = ssh->agent_response_len;
4922 s->response = (unsigned char *) r;
4923 if (s->response && s->responselen >= 5 &&
4924 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4925 s->p = s->response + 5;
4926 s->nkeys = GET_32BIT(s->p);
4930 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4933 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4938 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4941 s->pklen = GET_32BIT(s->p);
4943 if (s->publickey_blob &&
4944 s->pklen == s->publickey_bloblen &&
4945 !memcmp(s->p, s->publickey_blob,
4946 s->publickey_bloblen)) {
4947 logevent("This key matches configured key file");
4948 s->tried_pubkey_config = 1;
4950 s->pkblob = (char *)s->p;
4952 s->alglen = GET_32BIT(s->pkblob);
4953 s->alg = s->pkblob + 4;
4954 s->commentlen = GET_32BIT(s->p);
4956 s->commentp = (char *)s->p;
4957 s->p += s->commentlen;
4958 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4959 ssh2_pkt_addstring(ssh, s->username);
4960 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4961 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4962 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4963 ssh2_pkt_addstring_start(ssh);
4964 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4965 ssh2_pkt_addstring_start(ssh);
4966 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4969 crWaitUntilV(ispkt);
4970 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4971 logevent("Key refused");
4975 if (flags & FLAG_VERBOSE) {
4976 c_write_str(ssh, "Authenticating with "
4978 c_write(ssh, s->commentp, s->commentlen);
4979 c_write_str(ssh, "\" from agent\r\n");
4983 * Server is willing to accept the key.
4984 * Construct a SIGN_REQUEST.
4986 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4987 ssh2_pkt_addstring(ssh, s->username);
4988 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4989 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4990 ssh2_pkt_addbool(ssh, TRUE);
4991 ssh2_pkt_addstring_start(ssh);
4992 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4993 ssh2_pkt_addstring_start(ssh);
4994 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4996 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4997 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4999 s->len = 1; /* message type */
5000 s->len += 4 + s->pklen; /* key blob */
5001 s->len += 4 + s->siglen; /* data to sign */
5002 s->len += 4; /* flags */
5003 s->agentreq = snewn(4 + s->len, char);
5004 PUT_32BIT(s->agentreq, s->len);
5005 s->q = s->agentreq + 4;
5006 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5007 PUT_32BIT(s->q, s->pklen);
5009 memcpy(s->q, s->pkblob, s->pklen);
5011 PUT_32BIT(s->q, s->siglen);
5013 /* Now the data to be signed... */
5014 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5015 PUT_32BIT(s->q, 20);
5018 memcpy(s->q, ssh->v2_session_id, 20);
5020 memcpy(s->q, ssh->pktout.data + 5,
5021 ssh->pktout.length - 5);
5022 s->q += ssh->pktout.length - 5;
5023 /* And finally the (zero) flags word. */
5025 if (!agent_query(s->agentreq, s->len + 4,
5027 ssh_agent_callback, ssh)) {
5031 bombout(("Unexpected data from server"
5032 " while waiting for agent"
5036 } while (ispkt || inlen > 0);
5037 vret = ssh->agent_response;
5038 s->retlen = ssh->agent_response_len;
5043 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5044 logevent("Sending Pageant's response");
5045 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5047 GET_32BIT(s->ret + 5));
5053 ("Pageant failed to answer challenge");
5064 if (!s->method && s->can_pubkey && s->publickey_blob
5065 && !s->tried_pubkey_config) {
5066 unsigned char *pub_blob;
5067 char *algorithm, *comment;
5070 s->tried_pubkey_config = TRUE;
5072 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5073 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5076 * Try the public key supplied in the configuration.
5078 * First, offer the public blob to see if the server is
5079 * willing to accept it.
5082 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
5087 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5088 ssh2_pkt_addstring(ssh, s->username);
5089 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5090 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5091 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5092 ssh2_pkt_addstring(ssh, algorithm);
5093 ssh2_pkt_addstring_start(ssh);
5094 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5097 logevent("Offered public key"); /* FIXME */
5099 crWaitUntilV(ispkt);
5100 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5102 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
5103 continue; /* key refused; give up on it */
5106 logevent("Offer of public key accepted");
5108 * Actually attempt a serious authentication using
5111 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
5112 sprintf(s->pwprompt,
5113 "Passphrase for key \"%.100s\": ",
5119 if (flags & FLAG_VERBOSE) {
5120 c_write_str(ssh, "Authenticating with public key \"");
5121 c_write_str(ssh, comment);
5122 c_write_str(ssh, "\"\r\n");
5124 s->method = AUTH_PUBLICKEY_FILE;
5128 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5129 s->method = AUTH_KEYBOARD_INTERACTIVE;
5130 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5131 s->tried_keyb_inter = TRUE;
5133 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5134 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5136 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5137 ssh2_pkt_addstring(ssh, s->username);
5138 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5139 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5140 ssh2_pkt_addstring(ssh, ""); /* lang */
5141 ssh2_pkt_addstring(ssh, "");
5144 crWaitUntilV(ispkt);
5145 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5146 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5148 logevent("Keyboard-interactive authentication refused");
5149 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5153 s->kbd_inter_running = TRUE;
5157 if (s->kbd_inter_running) {
5158 s->method = AUTH_KEYBOARD_INTERACTIVE;
5159 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5160 s->tried_keyb_inter = TRUE;
5162 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5163 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5165 if (s->curr_prompt == 0) {
5167 * We've got a fresh USERAUTH_INFO_REQUEST.
5168 * Display header data, and start going through
5171 char *name, *inst, *lang;
5172 int name_len, inst_len, lang_len;
5174 ssh_pkt_getstring(ssh, &name, &name_len);
5175 ssh_pkt_getstring(ssh, &inst, &inst_len);
5176 ssh_pkt_getstring(ssh, &lang, &lang_len);
5178 c_write_untrusted(ssh, name, name_len);
5179 c_write_str(ssh, "\r\n");
5182 c_write_untrusted(ssh, inst, inst_len);
5183 c_write_str(ssh, "\r\n");
5185 s->num_prompts = ssh_pkt_getuint32(ssh);
5189 * If there are prompts remaining in the packet,
5190 * display one and get a response.
5192 if (s->curr_prompt < s->num_prompts) {
5196 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
5197 if (prompt_len > 0) {
5198 static const char trunc[] = "<prompt truncated>: ";
5199 static const int prlen = sizeof(s->pwprompt) -
5201 if (prompt_len > prlen) {
5202 memcpy(s->pwprompt, prompt, prlen);
5203 strcpy(s->pwprompt + prlen, trunc);
5205 memcpy(s->pwprompt, prompt, prompt_len);
5206 s->pwprompt[prompt_len] = '\0';
5210 "<server failed to send prompt>: ");
5212 s->echo = ssh2_pkt_getbool(ssh);
5218 if (!s->method && s->can_passwd) {
5219 s->method = AUTH_PASSWORD;
5220 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5221 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5222 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5229 if (!ssh_get_line(s->pwprompt, s->password,
5230 sizeof(s->password), TRUE)) {
5232 * get_line failed to get a password (for
5233 * example because one was supplied on the
5234 * command line which has already failed to
5237 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5238 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5239 ssh2_pkt_addstring(ssh, "No more passwords available"
5241 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5243 logevent("Unable to authenticate");
5244 connection_fatal(ssh->frontend,
5245 "Unable to authenticate");
5246 ssh_closing((Plug)ssh, NULL, 0, 0);
5250 int ret; /* need not be saved across crReturn */
5251 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5254 setup_userpass_input(ssh, s->password,
5255 sizeof(s->password), s->echo);
5257 crWaitUntilV(!ispkt);
5258 ret = process_userpass_input(ssh, in, inlen);
5262 c_write_str(ssh, "\r\n");
5266 if (s->method == AUTH_PUBLICKEY_FILE) {
5268 * We have our passphrase. Now try the actual authentication.
5270 struct ssh2_userkey *key;
5271 const char *error = NULL;
5273 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5275 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5276 if (key == SSH2_WRONG_PASSPHRASE) {
5277 c_write_str(ssh, "Wrong passphrase\r\n");
5278 s->tried_pubkey_config = FALSE;
5280 c_write_str(ssh, "Unable to load private key (");
5281 c_write_str(ssh, error);
5282 c_write_str(ssh, ")\r\n");
5283 s->tried_pubkey_config = TRUE;
5285 /* Send a spurious AUTH_NONE to return to the top. */
5286 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5287 ssh2_pkt_addstring(ssh, s->username);
5288 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5289 ssh2_pkt_addstring(ssh, "none"); /* method */
5291 s->type = AUTH_TYPE_NONE;
5293 unsigned char *pkblob, *sigblob, *sigdata;
5294 int pkblob_len, sigblob_len, sigdata_len;
5298 * We have loaded the private key and the server
5299 * has announced that it's willing to accept it.
5300 * Hallelujah. Generate a signature and send it.
5302 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5303 ssh2_pkt_addstring(ssh, s->username);
5304 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5305 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5306 ssh2_pkt_addbool(ssh, TRUE);
5307 ssh2_pkt_addstring(ssh, key->alg->name);
5308 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5309 ssh2_pkt_addstring_start(ssh);
5310 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5313 * The data to be signed is:
5317 * followed by everything so far placed in the
5320 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5321 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5323 sigdata = snewn(sigdata_len, unsigned char);
5325 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5326 PUT_32BIT(sigdata+p, 20);
5329 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5330 memcpy(sigdata+p, ssh->pktout.data + 5,
5331 ssh->pktout.length - 5);
5332 p += ssh->pktout.length - 5;
5333 assert(p == sigdata_len);
5334 sigblob = key->alg->sign(key->data, (char *)sigdata,
5335 sigdata_len, &sigblob_len);
5336 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5337 sigblob, sigblob_len);
5343 s->type = AUTH_TYPE_PUBLICKEY;
5344 key->alg->freekey(key->data);
5346 } else if (s->method == AUTH_PASSWORD) {
5348 * We send the password packet lumped tightly together with
5349 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5350 * string long enough to make the total length of the two
5351 * packets constant. This should ensure that a passive
5352 * listener doing traffic analyis can't work out the length
5355 * For this to work, we need an assumption about the
5356 * maximum length of the password packet. I think 256 is
5357 * pretty conservative. Anyone using a password longer than
5358 * that probably doesn't have much to worry about from
5359 * people who find out how long their password is!
5361 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5362 ssh2_pkt_addstring(ssh, s->username);
5363 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5364 ssh2_pkt_addstring(ssh, "password");
5365 ssh2_pkt_addbool(ssh, FALSE);
5366 ssh2_pkt_addstring(ssh, s->password);
5367 memset(s->password, 0, sizeof(s->password));
5368 ssh2_pkt_defer(ssh);
5370 * We'll include a string that's an exact multiple of the
5371 * cipher block size. If the cipher is NULL for some
5372 * reason, we don't do this trick at all because we gain
5375 if (ssh->cscipher) {
5378 stringlen = (256 - ssh->deferred_len);
5379 stringlen += ssh->cscipher->blksize - 1;
5380 stringlen -= (stringlen % ssh->cscipher->blksize);
5383 * Temporarily disable actual compression,
5384 * so we can guarantee to get this string
5385 * exactly the length we want it. The
5386 * compression-disabling routine should
5387 * return an integer indicating how many
5388 * bytes we should adjust our string length
5392 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5394 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5395 ssh2_pkt_addstring_start(ssh);
5396 for (i = 0; i < stringlen; i++) {
5397 char c = (char) random_byte();
5398 ssh2_pkt_addstring_data(ssh, &c, 1);
5400 ssh2_pkt_defer(ssh);
5402 ssh_pkt_defersend(ssh);
5403 logevent("Sent password");
5404 s->type = AUTH_TYPE_PASSWORD;
5405 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5406 if (s->curr_prompt == 0) {
5407 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5408 ssh2_pkt_adduint32(ssh, s->num_prompts);
5410 if (s->need_pw) { /* only add pw if we just got one! */
5411 ssh2_pkt_addstring(ssh, s->password);
5412 memset(s->password, 0, sizeof(s->password));
5415 if (s->curr_prompt >= s->num_prompts) {
5419 * If there are prompts remaining, we set
5420 * `gotit' so that we won't attempt to get
5421 * another packet. Then we go back round the
5422 * loop and will end up retrieving another
5423 * prompt out of the existing packet. Funky or
5428 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5430 c_write_str(ssh, "No supported authentication methods"
5431 " left to try!\r\n");
5432 logevent("No supported authentications offered."
5434 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5435 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5436 ssh2_pkt_addstring(ssh, "No supported authentication"
5437 " methods available");
5438 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5440 ssh_closing((Plug)ssh, NULL, 0, 0);
5444 } while (!s->we_are_in);
5447 * Now we're authenticated for the connection protocol. The
5448 * connection protocol will automatically have started at this
5449 * point; there's no need to send SERVICE_REQUEST.
5453 * So now create a channel with a session in it.
5455 ssh->channels = newtree234(ssh_channelcmp);
5456 ssh->mainchan = snew(struct ssh_channel);
5457 ssh->mainchan->ssh = ssh;
5458 ssh->mainchan->localid = alloc_channel_id(ssh);
5459 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5460 ssh2_pkt_addstring(ssh, "session");
5461 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5462 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5463 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5464 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5466 crWaitUntilV(ispkt);
5467 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5468 bombout(("Server refused to open a session"));
5470 /* FIXME: error data comes back in FAILURE packet */
5472 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5473 bombout(("Server's channel confirmation cited wrong channel"));
5476 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5477 ssh->mainchan->type = CHAN_MAINSESSION;
5478 ssh->mainchan->closes = 0;
5479 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5480 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5481 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5482 add234(ssh->channels, ssh->mainchan);
5483 logevent("Opened channel for session");
5486 * Potentially enable X11 forwarding.
5488 if (ssh->cfg.x11_forward) {
5489 char proto[20], data[64];
5490 logevent("Requesting X11 forwarding");
5491 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5492 data, sizeof(data), ssh->cfg.x11_auth);
5493 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5494 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5495 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5496 ssh2_pkt_addstring(ssh, "x11-req");
5497 ssh2_pkt_addbool(ssh, 1); /* want reply */
5498 ssh2_pkt_addbool(ssh, 0); /* many connections */
5499 ssh2_pkt_addstring(ssh, proto);
5500 ssh2_pkt_addstring(ssh, data);
5501 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5505 crWaitUntilV(ispkt);
5506 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5507 unsigned i = ssh_pkt_getuint32(ssh);
5508 struct ssh_channel *c;
5509 c = find234(ssh->channels, &i, ssh_channelfind);
5511 continue; /* nonexistent channel */
5512 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5514 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5516 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5517 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5518 bombout(("Unexpected response to X11 forwarding request:"
5519 " packet type %d", ssh->pktin.type));
5522 logevent("X11 forwarding refused");
5524 logevent("X11 forwarding enabled");
5525 ssh->X11_fwd_enabled = TRUE;
5530 * Enable port forwardings.
5535 int sport,dport,sserv,dserv;
5536 char sports[256], dports[256], saddr[256], host[256];
5538 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5539 /* Add port forwardings. */
5540 ssh->portfwd_strptr = ssh->cfg.portfwd;
5541 while (*ssh->portfwd_strptr) {
5542 type = *ssh->portfwd_strptr++;
5545 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5546 if (*ssh->portfwd_strptr == ':') {
5548 * We've seen a colon in the middle of the
5549 * source port number. This means that
5550 * everything we've seen until now is the
5551 * source _address_, so we'll move it into
5552 * saddr and start sports from the beginning
5555 ssh->portfwd_strptr++;
5557 strcpy(saddr, sports);
5560 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5564 if (*ssh->portfwd_strptr == '\t')
5565 ssh->portfwd_strptr++;
5567 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5568 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5571 if (*ssh->portfwd_strptr == ':')
5572 ssh->portfwd_strptr++;
5574 while (*ssh->portfwd_strptr) {
5575 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5578 ssh->portfwd_strptr++;
5579 dport = atoi(dports);
5583 dport = net_service_lookup(dports);
5585 logeventf(ssh, "Service lookup failed for destination"
5586 " port \"%s\"", dports);
5590 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5592 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5594 sport = atoi(sports);
5598 sport = net_service_lookup(sports);
5600 logeventf(ssh, "Service lookup failed for source"
5601 " port \"%s\"", sports);
5604 if (sport && dport) {
5606 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5607 sport, ssh, &ssh->cfg);
5608 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5609 " forwarding to %s:%.*s%.*s%d%.*s",
5610 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5611 (int)(*saddr?1:0), ":",
5612 (int)(sserv ? strlen(sports) : 0), sports,
5613 sserv, "(", sport, sserv, ")",
5615 (int)(dserv ? strlen(dports) : 0), dports,
5616 dserv, "(", dport, dserv, ")");
5617 } else if (type == 'D') {
5618 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5619 sport, ssh, &ssh->cfg);
5620 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5621 " doing SOCKS dynamic forwarding",
5622 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5623 (int)(*saddr?1:0), ":",
5624 (int)(sserv ? strlen(sports) : 0), sports,
5625 sserv, "(", sport, sserv, ")");
5627 struct ssh_rportfwd *pf;
5628 pf = snew(struct ssh_rportfwd);
5629 strcpy(pf->dhost, host);
5632 if (add234(ssh->rportfwds, pf) != pf) {
5633 logeventf(ssh, "Duplicate remote port forwarding"
5634 " to %s:%d", host, dport);
5637 logeventf(ssh, "Requesting remote port "
5638 "%.*s%.*s%.*s%.*s%d%.*s"
5639 " forward to %s:%.*s%.*s%d%.*s",
5640 (int)(*saddr?strlen(saddr):0),
5642 (int)(*saddr?1:0), ":",
5643 (int)(sserv ? strlen(sports) : 0), sports,
5644 sserv, "(", sport, sserv, ")",
5646 (int)(dserv ? strlen(dports) : 0), dports,
5647 dserv, "(", dport, dserv, ")");
5648 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5649 ssh2_pkt_addstring(ssh, "tcpip-forward");
5650 ssh2_pkt_addbool(ssh, 1);/* want reply */
5652 ssh2_pkt_addstring(ssh, saddr);
5653 if (ssh->cfg.rport_acceptall)
5654 ssh2_pkt_addstring(ssh, "0.0.0.0");
5656 ssh2_pkt_addstring(ssh, "127.0.0.1");
5657 ssh2_pkt_adduint32(ssh, sport);
5661 crWaitUntilV(ispkt);
5662 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5663 unsigned i = ssh_pkt_getuint32(ssh);
5664 struct ssh_channel *c;
5665 c = find234(ssh->channels, &i, ssh_channelfind);
5667 continue;/* nonexistent channel */
5668 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5670 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5672 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5673 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5674 bombout(("Unexpected response to port "
5675 "forwarding request: packet type %d",
5679 logevent("Server refused this port forwarding");
5681 logevent("Remote port forwarding enabled");
5690 * Potentially enable agent forwarding.
5692 if (ssh->cfg.agentfwd && agent_exists()) {
5693 logevent("Requesting OpenSSH-style agent forwarding");
5694 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5695 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5696 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5697 ssh2_pkt_addbool(ssh, 1); /* want reply */
5701 crWaitUntilV(ispkt);
5702 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5703 unsigned i = ssh_pkt_getuint32(ssh);
5704 struct ssh_channel *c;
5705 c = find234(ssh->channels, &i, ssh_channelfind);
5707 continue; /* nonexistent channel */
5708 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5710 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5712 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5713 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5714 bombout(("Unexpected response to agent forwarding request:"
5715 " packet type %d", ssh->pktin.type));
5718 logevent("Agent forwarding refused");
5720 logevent("Agent forwarding enabled");
5721 ssh->agentfwd_enabled = TRUE;
5726 * Now allocate a pty for the session.
5728 if (!ssh->cfg.nopty) {
5729 /* Unpick the terminal-speed string. */
5730 /* XXX perhaps we should allow no speeds to be sent. */
5731 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5732 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5733 /* Build the pty request. */
5734 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5735 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5736 ssh2_pkt_addstring(ssh, "pty-req");
5737 ssh2_pkt_addbool(ssh, 1); /* want reply */
5738 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5739 ssh2_pkt_adduint32(ssh, ssh->term_width);
5740 ssh2_pkt_adduint32(ssh, ssh->term_height);
5741 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5742 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5743 ssh2_pkt_addstring_start(ssh);
5744 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
5745 ssh2_pkt_adduint32(ssh, ssh->ispeed);
5746 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
5747 ssh2_pkt_adduint32(ssh, ssh->ospeed);
5748 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
5750 ssh->state = SSH_STATE_INTERMED;
5753 crWaitUntilV(ispkt);
5754 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5755 unsigned i = ssh_pkt_getuint32(ssh);
5756 struct ssh_channel *c;
5757 c = find234(ssh->channels, &i, ssh_channelfind);
5759 continue; /* nonexistent channel */
5760 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5762 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5764 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5765 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5766 bombout(("Unexpected response to pty request:"
5767 " packet type %d", ssh->pktin.type));
5770 c_write_str(ssh, "Server refused to allocate pty\r\n");
5771 ssh->editing = ssh->echoing = 1;
5773 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5774 ssh->ospeed, ssh->ispeed);
5777 ssh->editing = ssh->echoing = 1;
5781 * Start a shell or a remote command. We may have to attempt
5782 * this twice if the config data has provided a second choice
5789 if (ssh->fallback_cmd) {
5790 subsys = ssh->cfg.ssh_subsys2;
5791 cmd = ssh->cfg.remote_cmd_ptr2;
5793 subsys = ssh->cfg.ssh_subsys;
5794 cmd = ssh->cfg.remote_cmd_ptr;
5797 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5798 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5800 ssh2_pkt_addstring(ssh, "subsystem");
5801 ssh2_pkt_addbool(ssh, 1); /* want reply */
5802 ssh2_pkt_addstring(ssh, cmd);
5804 ssh2_pkt_addstring(ssh, "exec");
5805 ssh2_pkt_addbool(ssh, 1); /* want reply */
5806 ssh2_pkt_addstring(ssh, cmd);
5808 ssh2_pkt_addstring(ssh, "shell");
5809 ssh2_pkt_addbool(ssh, 1); /* want reply */
5813 crWaitUntilV(ispkt);
5814 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5815 unsigned i = ssh_pkt_getuint32(ssh);
5816 struct ssh_channel *c;
5817 c = find234(ssh->channels, &i, ssh_channelfind);
5819 continue; /* nonexistent channel */
5820 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5822 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5823 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5824 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5825 bombout(("Unexpected response to shell/command request:"
5826 " packet type %d", ssh->pktin.type));
5830 * We failed to start the command. If this is the
5831 * fallback command, we really are finished; if it's
5832 * not, and if the fallback command exists, try falling
5833 * back to it before complaining.
5835 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5836 logevent("Primary command failed; attempting fallback");
5837 ssh->fallback_cmd = TRUE;
5840 bombout(("Server refused to start a shell/command"));
5843 logevent("Started a shell/command");
5848 ssh->state = SSH_STATE_SESSION;
5849 if (ssh->size_needed)
5850 ssh_size(ssh, ssh->term_width, ssh->term_height);
5851 if (ssh->eof_needed)
5852 ssh_special(ssh, TS_EOF);
5858 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5862 s->try_send = FALSE;
5864 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5865 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5868 unsigned i = ssh_pkt_getuint32(ssh);
5869 struct ssh_channel *c;
5870 c = find234(ssh->channels, &i, ssh_channelfind);
5872 continue; /* nonexistent channel */
5873 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5874 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5875 continue; /* extended but not stderr */
5876 ssh_pkt_getstring(ssh, &data, &length);
5879 c->v.v2.locwindow -= length;
5881 case CHAN_MAINSESSION:
5883 from_backend(ssh->frontend, ssh->pktin.type ==
5884 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5888 bufsize = x11_send(c->u.x11.s, data, length);
5891 bufsize = pfd_send(c->u.pfd.s, data, length);
5894 while (length > 0) {
5895 if (c->u.a.lensofar < 4) {
5896 int l = min(4 - c->u.a.lensofar, length);
5897 memcpy(c->u.a.msglen + c->u.a.lensofar,
5901 c->u.a.lensofar += l;
5903 if (c->u.a.lensofar == 4) {
5905 4 + GET_32BIT(c->u.a.msglen);
5906 c->u.a.message = snewn(c->u.a.totallen,
5908 memcpy(c->u.a.message, c->u.a.msglen, 4);
5910 if (c->u.a.lensofar >= 4 && length > 0) {
5912 min(c->u.a.totallen - c->u.a.lensofar,
5914 memcpy(c->u.a.message + c->u.a.lensofar,
5918 c->u.a.lensofar += l;
5920 if (c->u.a.lensofar == c->u.a.totallen) {
5923 if (agent_query(c->u.a.message,
5926 ssh_agentf_callback, c))
5927 ssh_agentf_callback(c, reply, replylen);
5928 sfree(c->u.a.message);
5929 c->u.a.lensofar = 0;
5936 * If we are not buffering too much data,
5937 * enlarge the window again at the remote side.
5939 if (bufsize < OUR_V2_WINSIZE)
5940 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5942 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5943 unsigned i = ssh_pkt_getuint32(ssh);
5944 struct ssh_channel *c;
5946 c = find234(ssh->channels, &i, ssh_channelfind);
5948 continue; /* nonexistent channel */
5950 if (c->type == CHAN_X11) {
5952 * Remote EOF on an X11 channel means we should
5953 * wrap up and close the channel ourselves.
5955 x11_close(c->u.x11.s);
5957 } else if (c->type == CHAN_AGENT) {
5959 } else if (c->type == CHAN_SOCKDATA) {
5960 pfd_close(c->u.pfd.s);
5963 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5964 unsigned i = ssh_pkt_getuint32(ssh);
5965 struct ssh_channel *c;
5967 c = find234(ssh->channels, &i, ssh_channelfind);
5968 if (!c || ((int)c->remoteid) == -1) {
5969 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5970 c ? "half-open" : "nonexistent", i));
5973 /* Do pre-close processing on the channel. */
5975 case CHAN_MAINSESSION:
5976 break; /* nothing to see here, move along */
5978 if (c->u.x11.s != NULL)
5979 x11_close(c->u.x11.s);
5986 if (c->u.pfd.s != NULL)
5987 pfd_close(c->u.pfd.s);
5991 if (c->closes == 0) {
5992 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5993 ssh2_pkt_adduint32(ssh, c->remoteid);
5996 del234(ssh->channels, c);
5997 bufchain_clear(&c->v.v2.outbuffer);
6001 * See if that was the last channel left open.
6003 if (count234(ssh->channels) == 0) {
6004 logevent("All channels closed. Disconnecting");
6007 * We used to send SSH_MSG_DISCONNECT here,
6008 * because I'd believed that _every_ conforming
6009 * SSH2 connection had to end with a disconnect
6010 * being sent by at least one side; apparently
6011 * I was wrong and it's perfectly OK to
6012 * unceremoniously slam the connection shut
6013 * when you're done, and indeed OpenSSH feels
6014 * this is more polite than sending a
6015 * DISCONNECT. So now we don't.
6017 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6018 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6019 ssh2_pkt_addstring(ssh, "All open channels closed");
6020 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6023 ssh_closing((Plug)ssh, NULL, 0, 0);
6026 continue; /* remote sends close; ignore (FIXME) */
6027 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6028 unsigned i = ssh_pkt_getuint32(ssh);
6029 struct ssh_channel *c;
6030 c = find234(ssh->channels, &i, ssh_channelfind);
6031 if (!c || c->closes)
6032 continue; /* nonexistent or closing channel */
6033 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6035 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6036 unsigned i = ssh_pkt_getuint32(ssh);
6037 struct ssh_channel *c;
6038 c = find234(ssh->channels, &i, ssh_channelfind);
6040 continue; /* nonexistent channel */
6041 if (c->type != CHAN_SOCKDATA_DORMANT)
6042 continue; /* dunno why they're confirming this */
6043 c->remoteid = ssh_pkt_getuint32(ssh);
6044 c->type = CHAN_SOCKDATA;
6045 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6046 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
6048 pfd_confirm(c->u.pfd.s);
6051 * We have a pending close on this channel,
6052 * which we decided on before the server acked
6053 * the channel open. So now we know the
6054 * remoteid, we can close it again.
6056 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6057 ssh2_pkt_adduint32(ssh, c->remoteid);
6060 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
6061 unsigned i = ssh_pkt_getuint32(ssh);
6062 struct ssh_channel *c;
6063 c = find234(ssh->channels, &i, ssh_channelfind);
6065 continue; /* nonexistent channel */
6066 if (c->type != CHAN_SOCKDATA_DORMANT)
6067 continue; /* dunno why they're failing this */
6069 logevent("Forwarded connection refused by server");
6071 pfd_close(c->u.pfd.s);
6073 del234(ssh->channels, c);
6075 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
6078 int typelen, want_reply;
6079 struct ssh_channel *c;
6081 localid = ssh_pkt_getuint32(ssh);
6082 ssh_pkt_getstring(ssh, &type, &typelen);
6083 want_reply = ssh2_pkt_getbool(ssh);
6086 * First, check that the channel exists. Otherwise,
6087 * we can instantly disconnect with a rude message.
6089 c = find234(ssh->channels, &localid, ssh_channelfind);
6092 sprintf(buf, "Received channel request for nonexistent"
6093 " channel %d", localid);
6095 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6096 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6097 ssh2_pkt_addstring(ssh, buf);
6098 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6100 connection_fatal(ssh->frontend, "%s", buf);
6101 ssh_closing((Plug)ssh, NULL, 0, 0);
6106 * Having got the channel number, we now look at
6107 * the request type string to see if it's something
6110 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
6111 c == ssh->mainchan) {
6112 /* We recognise "exit-status" on the primary channel. */
6114 ssh->exitcode = ssh_pkt_getuint32(ssh);
6115 sprintf(buf, "Server sent command exit status %d",
6119 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
6120 ssh2_pkt_adduint32(ssh, c->remoteid);
6125 * This is a channel request we don't know
6126 * about, so we now either ignore the request
6127 * or respond with CHANNEL_FAILURE, depending
6131 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
6132 ssh2_pkt_adduint32(ssh, c->remoteid);
6136 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
6138 int typelen, want_reply;
6140 ssh_pkt_getstring(ssh, &type, &typelen);
6141 want_reply = ssh2_pkt_getbool(ssh);
6144 * We currently don't support any global requests
6145 * at all, so we either ignore the request or
6146 * respond with REQUEST_FAILURE, depending on
6150 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6153 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6160 struct ssh_channel *c;
6161 unsigned remid, winsize, pktsize;
6162 ssh_pkt_getstring(ssh, &type, &typelen);
6163 c = snew(struct ssh_channel);
6166 remid = ssh_pkt_getuint32(ssh);
6167 winsize = ssh_pkt_getuint32(ssh);
6168 pktsize = ssh_pkt_getuint32(ssh);
6170 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6173 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6174 addrstr = snewn(peeraddrlen+1, char);
6175 memcpy(addrstr, peeraddr, peeraddrlen);
6176 addrstr[peeraddrlen] = '\0';
6177 peerport = ssh_pkt_getuint32(ssh);
6179 logeventf(ssh, "Received X11 connect request from %s:%d",
6182 if (!ssh->X11_fwd_enabled)
6183 error = "X11 forwarding is not enabled";
6184 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6185 ssh->x11auth, addrstr, peerport,
6186 &ssh->cfg) != NULL) {
6187 error = "Unable to open an X11 connection";
6189 logevent("Opening X11 forward connection succeeded");
6194 } else if (typelen == 15 &&
6195 !memcmp(type, "forwarded-tcpip", 15)) {
6196 struct ssh_rportfwd pf, *realpf;
6199 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6200 pf.sport = ssh_pkt_getuint32(ssh);
6201 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6202 peerport = ssh_pkt_getuint32(ssh);
6203 realpf = find234(ssh->rportfwds, &pf, NULL);
6204 logeventf(ssh, "Received remote port %d open request "
6205 "from %s:%d", pf.sport, peeraddr, peerport);
6206 if (realpf == NULL) {
6207 error = "Remote port is not recognised";
6209 const char *e = pfd_newconnect(&c->u.pfd.s,
6213 logeventf(ssh, "Attempting to forward remote port to "
6214 "%s:%d", realpf->dhost, realpf->dport);
6216 logeventf(ssh, "Port open failed: %s", e);
6217 error = "Port open failed";
6219 logevent("Forwarded port opened successfully");
6220 c->type = CHAN_SOCKDATA;
6223 } else if (typelen == 22 &&
6224 !memcmp(type, "auth-agent@openssh.com", 3)) {
6225 if (!ssh->agentfwd_enabled)
6226 error = "Agent forwarding is not enabled";
6228 c->type = CHAN_AGENT; /* identify channel type */
6229 c->u.a.lensofar = 0;
6232 error = "Unsupported channel type requested";
6235 c->remoteid = remid;
6237 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6238 ssh2_pkt_adduint32(ssh, c->remoteid);
6239 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6240 ssh2_pkt_addstring(ssh, error);
6241 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6243 logeventf(ssh, "Rejected channel open: %s", error);
6246 c->localid = alloc_channel_id(ssh);
6248 c->v.v2.locwindow = OUR_V2_WINSIZE;
6249 c->v.v2.remwindow = winsize;
6250 c->v.v2.remmaxpkt = pktsize;
6251 bufchain_init(&c->v.v2.outbuffer);
6252 add234(ssh->channels, c);
6253 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6254 ssh2_pkt_adduint32(ssh, c->remoteid);
6255 ssh2_pkt_adduint32(ssh, c->localid);
6256 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6257 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6261 bombout(("Strange packet received: type %d", ssh->pktin.type));
6266 * We have spare data. Add it to the channel buffer.
6268 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6273 struct ssh_channel *c;
6275 * Try to send data on all channels if we can.
6277 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6280 continue; /* don't send on closing channels */
6281 bufsize = ssh2_try_send(c);
6284 case CHAN_MAINSESSION:
6285 /* stdin need not receive an unthrottle
6286 * notification since it will be polled */
6289 x11_unthrottle(c->u.x11.s);
6292 /* agent sockets are request/response and need no
6293 * buffer management */
6296 pfd_unthrottle(c->u.pfd.s);
6308 * Handle the top-level SSH2 protocol.
6310 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6312 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6314 do_ssh2_authconn(ssh, in, inlen, ispkt);
6318 * Called to set up the connection.
6320 * Returns an error message, or NULL on success.
6322 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6324 char *host, int port, char **realhost, int nodelay,
6330 ssh = snew(struct ssh_tag);
6331 ssh->cfg = *cfg; /* STRUCTURE COPY */
6332 ssh->version = 0; /* when not ready yet */
6335 ssh->v1_cipher_ctx = NULL;
6336 ssh->crcda_ctx = NULL;
6337 ssh->cscipher = NULL;
6338 ssh->cs_cipher_ctx = NULL;
6339 ssh->sccipher = NULL;
6340 ssh->sc_cipher_ctx = NULL;
6342 ssh->cs_mac_ctx = NULL;
6344 ssh->sc_mac_ctx = NULL;
6346 ssh->cs_comp_ctx = NULL;
6348 ssh->sc_comp_ctx = NULL;
6350 ssh->kex_ctx = NULL;
6351 ssh->hostkey = NULL;
6353 ssh->state = SSH_STATE_PREPACKET;
6354 ssh->size_needed = FALSE;
6355 ssh->eof_needed = FALSE;
6359 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6360 ssh->pktin = ssh->pktout = empty;
6362 ssh->deferred_send_data = NULL;
6363 ssh->deferred_len = 0;
6364 ssh->deferred_size = 0;
6365 ssh->fallback_cmd = 0;
6367 ssh->x11auth = NULL;
6368 ssh->v1_compressing = FALSE;
6369 ssh->v2_outgoing_sequence = 0;
6370 ssh->ssh1_rdpkt_crstate = 0;
6371 ssh->ssh2_rdpkt_crstate = 0;
6372 ssh->do_ssh_init_crstate = 0;
6373 ssh->ssh_gotdata_crstate = 0;
6374 ssh->ssh1_protocol_crstate = 0;
6375 ssh->do_ssh1_login_crstate = 0;
6376 ssh->do_ssh2_transport_crstate = 0;
6377 ssh->do_ssh2_authconn_crstate = 0;
6378 ssh->do_ssh_init_state = NULL;
6379 ssh->do_ssh1_login_state = NULL;
6380 ssh->do_ssh2_transport_state = NULL;
6381 ssh->do_ssh2_authconn_state = NULL;
6382 ssh->mainchan = NULL;
6383 ssh->throttled_all = 0;
6384 ssh->v1_stdout_throttling = 0;
6386 *backend_handle = ssh;
6389 if (crypto_startup() == 0)
6390 return "Microsoft high encryption pack not installed!";
6393 ssh->frontend = frontend_handle;
6394 ssh->term_width = ssh->cfg.width;
6395 ssh->term_height = ssh->cfg.height;
6397 ssh->channels = NULL;
6398 ssh->rportfwds = NULL;
6403 ssh->v1_throttle_count = 0;
6404 ssh->overall_bufsize = 0;
6405 ssh->fallback_cmd = 0;
6407 ssh->protocol = NULL;
6409 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
6416 static void ssh_free(void *handle)
6418 Ssh ssh = (Ssh) handle;
6419 struct ssh_channel *c;
6420 struct ssh_rportfwd *pf;
6422 if (ssh->v1_cipher_ctx)
6423 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6424 if (ssh->cs_cipher_ctx)
6425 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6426 if (ssh->sc_cipher_ctx)
6427 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6428 if (ssh->cs_mac_ctx)
6429 ssh->csmac->free_context(ssh->cs_mac_ctx);
6430 if (ssh->sc_mac_ctx)
6431 ssh->scmac->free_context(ssh->sc_mac_ctx);
6432 if (ssh->cs_comp_ctx) {
6434 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6436 zlib_compress_cleanup(ssh->cs_comp_ctx);
6438 if (ssh->sc_comp_ctx) {
6440 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6442 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6445 dh_cleanup(ssh->kex_ctx);
6446 sfree(ssh->savedhost);
6448 if (ssh->channels) {
6449 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6452 if (c->u.x11.s != NULL)
6453 x11_close(c->u.x11.s);
6456 if (c->u.pfd.s != NULL)
6457 pfd_close(c->u.pfd.s);
6462 freetree234(ssh->channels);
6465 if (ssh->rportfwds) {
6466 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6468 freetree234(ssh->rportfwds);
6470 sfree(ssh->deferred_send_data);
6472 x11_free_auth(ssh->x11auth);
6473 sfree(ssh->do_ssh_init_state);
6474 sfree(ssh->do_ssh1_login_state);
6475 sfree(ssh->do_ssh2_transport_state);
6476 sfree(ssh->do_ssh2_authconn_state);
6477 if (ssh->pktout.data) {
6478 sfree(ssh->pktout.data);
6479 ssh->pktout.data = NULL;
6481 if (ssh->pktin.data) {
6482 sfree(ssh->pktin.data);
6483 ssh->pktin.data = NULL;
6485 if (ssh->crcda_ctx) {
6486 crcda_free_context(ssh->crcda_ctx);
6487 ssh->crcda_ctx = NULL;
6495 * Reconfigure the SSH backend.
6497 * Currently, this function does nothing very useful. In future,
6498 * however, we could do some handy things with it. For example, we
6499 * could make the port forwarding configurer active in the Change
6500 * Settings box, and this routine could close down existing
6501 * forwardings and open up new ones in response to changes.
6503 static void ssh_reconfig(void *handle, Config *cfg)
6505 Ssh ssh = (Ssh) handle;
6506 ssh->cfg = *cfg; /* STRUCTURE COPY */
6510 * Called to send data down the Telnet connection.
6512 static int ssh_send(void *handle, char *buf, int len)
6514 Ssh ssh = (Ssh) handle;
6516 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6519 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6521 return ssh_sendbuffer(ssh);
6525 * Called to query the current amount of buffered stdin data.
6527 static int ssh_sendbuffer(void *handle)
6529 Ssh ssh = (Ssh) handle;
6532 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6536 * If the SSH socket itself has backed up, add the total backup
6537 * size on that to any individual buffer on the stdin channel.
6540 if (ssh->throttled_all)
6541 override_value = ssh->overall_bufsize;
6543 if (ssh->version == 1) {
6544 return override_value;
6545 } else if (ssh->version == 2) {
6546 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6547 return override_value;
6549 return (override_value +
6550 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6557 * Called to set the size of the window from SSH's POV.
6559 static void ssh_size(void *handle, int width, int height)
6561 Ssh ssh = (Ssh) handle;
6563 ssh->term_width = width;
6564 ssh->term_height = height;
6566 switch (ssh->state) {
6567 case SSH_STATE_BEFORE_SIZE:
6568 case SSH_STATE_PREPACKET:
6569 case SSH_STATE_CLOSED:
6570 break; /* do nothing */
6571 case SSH_STATE_INTERMED:
6572 ssh->size_needed = TRUE; /* buffer for later */
6574 case SSH_STATE_SESSION:
6575 if (!ssh->cfg.nopty) {
6576 if (ssh->version == 1) {
6577 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6578 PKT_INT, ssh->term_height,
6579 PKT_INT, ssh->term_width,
6580 PKT_INT, 0, PKT_INT, 0, PKT_END);
6582 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6583 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6584 ssh2_pkt_addstring(ssh, "window-change");
6585 ssh2_pkt_addbool(ssh, 0);
6586 ssh2_pkt_adduint32(ssh, ssh->term_width);
6587 ssh2_pkt_adduint32(ssh, ssh->term_height);
6588 ssh2_pkt_adduint32(ssh, 0);
6589 ssh2_pkt_adduint32(ssh, 0);
6598 * Return a list of the special codes that make sense in this
6601 static const struct telnet_special *ssh_get_specials(void *handle)
6603 Ssh ssh = (Ssh) handle;
6605 if (ssh->version == 1) {
6606 static const struct telnet_special ssh1_specials[] = {
6607 {"IGNORE message", TS_NOP},
6610 return ssh1_specials;
6611 } else if (ssh->version == 2) {
6612 static const struct telnet_special ssh2_specials[] = {
6614 {"IGNORE message", TS_NOP},
6617 return ssh2_specials;
6623 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6624 * can send an EOF and collect resulting output (e.g. `plink
6627 static void ssh_special(void *handle, Telnet_Special code)
6629 Ssh ssh = (Ssh) handle;
6631 if (code == TS_EOF) {
6632 if (ssh->state != SSH_STATE_SESSION) {
6634 * Buffer the EOF in case we are pre-SESSION, so we can
6635 * send it as soon as we reach SESSION.
6638 ssh->eof_needed = TRUE;
6641 if (ssh->version == 1) {
6642 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6644 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6645 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6648 logevent("Sent EOF message");
6649 } else if (code == TS_PING || code == TS_NOP) {
6650 if (ssh->state == SSH_STATE_CLOSED
6651 || ssh->state == SSH_STATE_PREPACKET) return;
6652 if (ssh->version == 1) {
6653 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6654 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6656 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6657 ssh2_pkt_addstring_start(ssh);
6660 } else if (code == TS_BRK) {
6661 if (ssh->state == SSH_STATE_CLOSED
6662 || ssh->state == SSH_STATE_PREPACKET) return;
6663 if (ssh->version == 1) {
6664 logevent("Unable to send BREAK signal in SSH1");
6666 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6667 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6668 ssh2_pkt_addstring(ssh, "break");
6669 ssh2_pkt_addbool(ssh, 0);
6670 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6678 void *new_sock_channel(void *handle, Socket s)
6680 Ssh ssh = (Ssh) handle;
6681 struct ssh_channel *c;
6682 c = snew(struct ssh_channel);
6686 c->remoteid = -1; /* to be set when open confirmed */
6687 c->localid = alloc_channel_id(ssh);
6689 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6691 bufchain_init(&c->v.v2.outbuffer);
6692 add234(ssh->channels, c);
6698 * This is called when stdout/stderr (the entity to which
6699 * from_backend sends data) manages to clear some backlog.
6701 static void ssh_unthrottle(void *handle, int bufsize)
6703 Ssh ssh = (Ssh) handle;
6704 if (ssh->version == 1) {
6705 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6706 ssh->v1_stdout_throttling = 0;
6707 ssh1_throttle(ssh, -1);
6710 if (ssh->mainchan && ssh->mainchan->closes == 0)
6711 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6715 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6717 struct ssh_channel *c = (struct ssh_channel *)channel;
6720 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6722 if (ssh->version == 1) {
6723 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6724 PKT_INT, c->localid,
6727 //PKT_STR, <org:orgport>,
6730 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6731 ssh2_pkt_addstring(ssh, "direct-tcpip");
6732 ssh2_pkt_adduint32(ssh, c->localid);
6733 c->v.v2.locwindow = OUR_V2_WINSIZE;
6734 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6735 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6736 ssh2_pkt_addstring(ssh, hostname);
6737 ssh2_pkt_adduint32(ssh, port);
6739 * We make up values for the originator data; partly it's
6740 * too much hassle to keep track, and partly I'm not
6741 * convinced the server should be told details like that
6742 * about my local network configuration.
6744 ssh2_pkt_addstring(ssh, "client-side-connection");
6745 ssh2_pkt_adduint32(ssh, 0);
6751 static Socket ssh_socket(void *handle)
6753 Ssh ssh = (Ssh) handle;
6757 static int ssh_sendok(void *handle)
6759 Ssh ssh = (Ssh) handle;
6760 return ssh->send_ok;
6763 static int ssh_ldisc(void *handle, int option)
6765 Ssh ssh = (Ssh) handle;
6766 if (option == LD_ECHO)
6767 return ssh->echoing;
6768 if (option == LD_EDIT)
6769 return ssh->editing;
6773 static void ssh_provide_ldisc(void *handle, void *ldisc)
6775 Ssh ssh = (Ssh) handle;
6779 static void ssh_provide_logctx(void *handle, void *logctx)
6781 Ssh ssh = (Ssh) handle;
6782 ssh->logctx = logctx;
6785 static int ssh_return_exitcode(void *handle)
6787 Ssh ssh = (Ssh) handle;
6791 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6795 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6796 * that fails. This variable is the means by which scp.c can reach
6797 * into the SSH code and find out which one it got.
6799 extern int ssh_fallback_cmd(void *handle)
6801 Ssh ssh = (Ssh) handle;
6802 return ssh->fallback_cmd;
6805 Backend ssh_backend = {
6815 ssh_return_exitcode,