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 term_width, term_height;
578 tree234 *channels; /* indexed by local id */
579 struct ssh_channel *mainchan; /* primary session channel */
586 SSH_STATE_BEFORE_SIZE,
592 int size_needed, eof_needed;
595 struct Packet pktout;
596 unsigned char *deferred_send_data;
597 int deferred_len, deferred_size;
600 * Gross hack: pscp will try to start SFTP but fall back to
601 * scp1 if that fails. This variable is the means by which
602 * scp.c can reach into the SSH code and find out which one it
608 * Used for username and password input.
610 char *userpass_input_buffer;
611 int userpass_input_buflen;
612 int userpass_input_bufpos;
613 int userpass_input_echo;
615 char *portfwd_strptr;
621 int v1_throttle_count;
624 int v1_stdout_throttling;
625 int v2_outgoing_sequence;
627 int ssh1_rdpkt_crstate;
628 int ssh2_rdpkt_crstate;
629 int do_ssh_init_crstate;
630 int ssh_gotdata_crstate;
631 int ssh1_protocol_crstate;
632 int do_ssh1_login_crstate;
633 int do_ssh2_transport_crstate;
634 int do_ssh2_authconn_crstate;
636 void *do_ssh_init_state;
637 void *do_ssh1_login_state;
638 void *do_ssh2_transport_state;
639 void *do_ssh2_authconn_state;
641 struct rdpkt1_state_tag rdpkt1_state;
642 struct rdpkt2_state_tag rdpkt2_state;
644 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
645 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
648 * We maintain a full _copy_ of a Config structure here, not
649 * merely a pointer to it. That way, when we're passed a new
650 * one for reconfiguration, we can check the differences and
651 * potentially reconfigure port forwardings etc in mid-session.
656 * Used to transfer data back from async agent callbacks.
658 void *agent_response;
659 int agent_response_len;
662 #define logevent(s) logevent(ssh->frontend, s)
664 /* logevent, only printf-formatted. */
665 static void logeventf(Ssh ssh, const char *fmt, ...)
671 buf = dupvprintf(fmt, ap);
677 #define bombout(msg) \
679 char *text = dupprintf msg; \
682 connection_fatal(ssh->frontend, "%s", text); \
686 static int ssh_channelcmp(void *av, void *bv)
688 struct ssh_channel *a = (struct ssh_channel *) av;
689 struct ssh_channel *b = (struct ssh_channel *) bv;
690 if (a->localid < b->localid)
692 if (a->localid > b->localid)
696 static int ssh_channelfind(void *av, void *bv)
698 unsigned *a = (unsigned *) av;
699 struct ssh_channel *b = (struct ssh_channel *) bv;
707 static int ssh_rportcmp_ssh1(void *av, void *bv)
709 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
710 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
712 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
713 return i < 0 ? -1 : +1;
714 if (a->dport > b->dport)
716 if (a->dport < b->dport)
721 static int ssh_rportcmp_ssh2(void *av, void *bv)
723 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
724 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
726 if (a->sport > b->sport)
728 if (a->sport < b->sport)
733 static int alloc_channel_id(Ssh ssh)
735 const unsigned CHANNEL_NUMBER_OFFSET = 256;
736 unsigned low, high, mid;
738 struct ssh_channel *c;
741 * First-fit allocation of channel numbers: always pick the
742 * lowest unused one. To do this, binary-search using the
743 * counted B-tree to find the largest channel ID which is in a
744 * contiguous sequence from the beginning. (Precisely
745 * everything in that sequence must have ID equal to its tree
746 * index plus CHANNEL_NUMBER_OFFSET.)
748 tsize = count234(ssh->channels);
752 while (high - low > 1) {
753 mid = (high + low) / 2;
754 c = index234(ssh->channels, mid);
755 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
756 low = mid; /* this one is fine */
758 high = mid; /* this one is past it */
761 * Now low points to either -1, or the tree index of the
762 * largest ID in the initial sequence.
765 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
766 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
768 return low + 1 + CHANNEL_NUMBER_OFFSET;
771 static void c_write(Ssh ssh, const char *buf, int len)
773 if ((flags & FLAG_STDERR)) {
775 for (i = 0; i < len; i++)
777 fputc(buf[i], stderr);
780 from_backend(ssh->frontend, 1, buf, len);
783 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
786 for (i = 0; i < len; i++) {
788 c_write(ssh, "\r\n", 2);
789 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
790 c_write(ssh, buf + i, 1);
794 static void c_write_str(Ssh ssh, const char *buf)
796 c_write(ssh, buf, strlen(buf));
800 * Collect incoming data in the incoming packet buffer.
801 * Decipher and verify the packet when it is completely read.
802 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
803 * Update the *data and *datalen variables.
804 * Return the additional nr of bytes needed, or 0 when
805 * a complete packet is available.
807 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
809 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
811 crBegin(ssh->ssh1_rdpkt_crstate);
816 ssh->pktin.length = 0;
818 for (st->i = st->len = 0; st->i < 4; st->i++) {
819 while ((*datalen) == 0)
821 st->len = (st->len << 8) + **data;
822 (*data)++, (*datalen)--;
825 st->pad = 8 - (st->len % 8);
826 st->biglen = st->len + st->pad;
827 ssh->pktin.length = st->len - 5;
829 if (ssh->pktin.maxlen < st->biglen) {
830 ssh->pktin.maxlen = st->biglen;
831 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
835 st->to_read = st->biglen;
836 st->p = ssh->pktin.data;
837 while (st->to_read > 0) {
838 st->chunk = st->to_read;
839 while ((*datalen) == 0)
840 crReturn(st->to_read);
841 if (st->chunk > (*datalen))
842 st->chunk = (*datalen);
843 memcpy(st->p, *data, st->chunk);
845 *datalen -= st->chunk;
847 st->to_read -= st->chunk;
850 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
852 bombout(("Network attack (CRC compensation) detected!"));
857 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
859 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
860 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
861 if (st->gotcrc != st->realcrc) {
862 bombout(("Incorrect CRC received on packet"));
866 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
868 if (ssh->v1_compressing) {
869 unsigned char *decompblk;
871 if (!zlib_decompress_block(ssh->sc_comp_ctx,
872 ssh->pktin.body - 1, ssh->pktin.length + 1,
873 &decompblk, &decomplen)) {
874 bombout(("Zlib decompression encountered invalid data"));
878 if (ssh->pktin.maxlen < st->pad + decomplen) {
879 ssh->pktin.maxlen = st->pad + decomplen;
880 ssh->pktin.data = sresize(ssh->pktin.data,
881 ssh->pktin.maxlen + APIEXTRA,
883 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
886 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
888 ssh->pktin.length = decomplen - 1;
891 ssh->pktin.type = ssh->pktin.body[-1];
894 log_packet(ssh->logctx,
895 PKT_INCOMING, ssh->pktin.type,
896 ssh1_pkt_type(ssh->pktin.type),
897 ssh->pktin.body, ssh->pktin.length);
899 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
900 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
901 ssh->pktin.type == SSH1_MSG_DEBUG ||
902 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
903 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
904 long stringlen = GET_32BIT(ssh->pktin.body);
905 if (stringlen + 4 != ssh->pktin.length) {
906 bombout(("Received data packet with bogus string length"));
911 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
912 /* log debug message */
914 int stringlen = GET_32BIT(ssh->pktin.body);
915 strcpy(buf, "Remote debug message: ");
918 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
919 buf[8 + stringlen] = '\0';
922 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
927 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
928 /* log reason code in disconnect message */
930 unsigned msglen = GET_32BIT(ssh->pktin.body);
932 strcpy(buf, "Remote sent disconnect: ");
933 nowlen = strlen(buf);
934 if (msglen > sizeof(buf) - nowlen - 1)
935 msglen = sizeof(buf) - nowlen - 1;
936 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
937 buf[nowlen + msglen] = '\0';
938 /* logevent(buf); (this is now done within the bombout macro) */
939 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
946 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
948 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
950 crBegin(ssh->ssh2_rdpkt_crstate);
954 ssh->pktin.length = 0;
956 st->cipherblk = ssh->sccipher->blksize;
959 if (st->cipherblk < 8)
962 if (ssh->pktin.maxlen < st->cipherblk) {
963 ssh->pktin.maxlen = st->cipherblk;
964 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
969 * Acquire and decrypt the first block of the packet. This will
970 * contain the length and padding details.
972 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
973 while ((*datalen) == 0)
974 crReturn(st->cipherblk - st->i);
975 ssh->pktin.data[st->i] = *(*data)++;
980 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
981 ssh->pktin.data, st->cipherblk);
984 * Now get the length and padding figures.
986 st->len = GET_32BIT(ssh->pktin.data);
987 st->pad = ssh->pktin.data[4];
990 * _Completely_ silly lengths should be stomped on before they
991 * do us any more damage.
993 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
994 bombout(("Incoming packet was garbled on decryption"));
999 * This enables us to deduce the payload length.
1001 st->payload = st->len - st->pad - 1;
1003 ssh->pktin.length = st->payload + 5;
1006 * So now we can work out the total packet length.
1008 st->packetlen = st->len + 4;
1009 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1012 * Adjust memory allocation if packet is too big.
1014 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1015 ssh->pktin.maxlen = st->packetlen + st->maclen;
1016 ssh->pktin.data = sresize(ssh->pktin.data,
1017 ssh->pktin.maxlen + APIEXTRA,
1022 * Read and decrypt the remainder of the packet.
1024 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1026 while ((*datalen) == 0)
1027 crReturn(st->packetlen + st->maclen - st->i);
1028 ssh->pktin.data[st->i] = *(*data)++;
1031 /* Decrypt everything _except_ the MAC. */
1033 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1034 ssh->pktin.data + st->cipherblk,
1035 st->packetlen - st->cipherblk);
1041 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1042 st->incoming_sequence)) {
1043 bombout(("Incorrect MAC received on packet"));
1046 st->incoming_sequence++; /* whether or not we MACed */
1049 * Decompress packet payload.
1052 unsigned char *newpayload;
1055 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1056 ssh->pktin.data + 5, ssh->pktin.length - 5,
1057 &newpayload, &newlen)) {
1058 if (ssh->pktin.maxlen < newlen + 5) {
1059 ssh->pktin.maxlen = newlen + 5;
1060 ssh->pktin.data = sresize(ssh->pktin.data,
1061 ssh->pktin.maxlen + APIEXTRA,
1064 ssh->pktin.length = 5 + newlen;
1065 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1070 ssh->pktin.savedpos = 6;
1071 ssh->pktin.type = ssh->pktin.data[5];
1074 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1075 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1076 ssh->pktin.data+6, ssh->pktin.length-6);
1078 switch (ssh->pktin.type) {
1080 * These packets we must handle instantly.
1082 case SSH2_MSG_DISCONNECT:
1084 /* log reason code in disconnect message */
1087 int reason = GET_32BIT(ssh->pktin.data + 6);
1088 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1090 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1091 buf = dupprintf("Received disconnect message (%s)",
1092 ssh2_disconnect_reasons[reason]);
1094 buf = dupprintf("Received disconnect message (unknown"
1095 " type %d)", reason);
1099 buf = dupprintf("Disconnection message text: %n%.*s",
1100 &nowlen, msglen, ssh->pktin.data + 14);
1102 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1104 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1105 ssh2_disconnect_reasons[reason] : "unknown",
1111 case SSH2_MSG_IGNORE:
1113 case SSH2_MSG_DEBUG:
1115 /* log the debug message */
1117 /* int display = ssh->pktin.body[6]; */
1118 int stringlen = GET_32BIT(ssh->pktin.data+7);
1120 strcpy(buf, "Remote debug message: ");
1121 prefix = strlen(buf);
1122 if (stringlen > (int)(sizeof(buf)-prefix-1))
1123 stringlen = sizeof(buf)-prefix-1;
1124 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1125 buf[prefix + stringlen] = '\0';
1128 goto next_packet; /* FIXME: print the debug message */
1131 * These packets we need do nothing about here.
1133 case SSH2_MSG_UNIMPLEMENTED:
1134 case SSH2_MSG_SERVICE_REQUEST:
1135 case SSH2_MSG_SERVICE_ACCEPT:
1136 case SSH2_MSG_KEXINIT:
1137 case SSH2_MSG_NEWKEYS:
1138 case SSH2_MSG_KEXDH_INIT:
1139 case SSH2_MSG_KEXDH_REPLY:
1140 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1141 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1142 case SSH2_MSG_KEX_DH_GEX_INIT:
1143 case SSH2_MSG_KEX_DH_GEX_REPLY:
1144 case SSH2_MSG_USERAUTH_REQUEST:
1145 case SSH2_MSG_USERAUTH_FAILURE:
1146 case SSH2_MSG_USERAUTH_SUCCESS:
1147 case SSH2_MSG_USERAUTH_BANNER:
1148 case SSH2_MSG_USERAUTH_PK_OK:
1149 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1150 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1151 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1152 case SSH2_MSG_GLOBAL_REQUEST:
1153 case SSH2_MSG_REQUEST_SUCCESS:
1154 case SSH2_MSG_REQUEST_FAILURE:
1155 case SSH2_MSG_CHANNEL_OPEN:
1156 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1157 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1158 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1159 case SSH2_MSG_CHANNEL_DATA:
1160 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1161 case SSH2_MSG_CHANNEL_EOF:
1162 case SSH2_MSG_CHANNEL_CLOSE:
1163 case SSH2_MSG_CHANNEL_REQUEST:
1164 case SSH2_MSG_CHANNEL_SUCCESS:
1165 case SSH2_MSG_CHANNEL_FAILURE:
1169 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1172 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1173 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1181 static void ssh1_pktout_size(Ssh ssh, int len)
1185 len += 5; /* type and CRC */
1186 pad = 8 - (len % 8);
1189 ssh->pktout.length = len - 5;
1190 if (ssh->pktout.maxlen < biglen) {
1191 ssh->pktout.maxlen = biglen;
1193 /* Allocate enough buffer space for extra block
1194 * for MS CryptEncrypt() */
1195 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1198 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1202 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1205 static void s_wrpkt_start(Ssh ssh, int type, int len)
1207 ssh1_pktout_size(ssh, len);
1208 ssh->pktout.type = type;
1211 static int s_wrpkt_prepare(Ssh ssh)
1217 * XXX various versions of SC (including 8.8.4) screw up the
1218 * register allocation in this function and use the same register
1219 * (D6) for len and as a temporary, with predictable results. The
1220 * following sledgehammer prevents this.
1226 ssh->pktout.body[-1] = ssh->pktout.type;
1229 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1230 ssh1_pkt_type(ssh->pktout.type),
1231 ssh->pktout.body, ssh->pktout.length);
1233 if (ssh->v1_compressing) {
1234 unsigned char *compblk;
1236 zlib_compress_block(ssh->cs_comp_ctx,
1237 ssh->pktout.body - 1, ssh->pktout.length + 1,
1238 &compblk, &complen);
1239 ssh1_pktout_size(ssh, complen - 1);
1240 memcpy(ssh->pktout.body - 1, compblk, complen);
1244 len = ssh->pktout.length + 5; /* type and CRC */
1245 pad = 8 - (len % 8);
1248 for (i = 0; i < pad; i++)
1249 ssh->pktout.data[i + 4] = random_byte();
1250 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1251 PUT_32BIT(ssh->pktout.data + biglen, crc);
1252 PUT_32BIT(ssh->pktout.data, len);
1255 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1260 static void s_wrpkt(Ssh ssh)
1263 len = s_wrpkt_prepare(ssh);
1264 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1265 if (backlog > SSH_MAX_BACKLOG)
1266 ssh_throttle_all(ssh, 1, backlog);
1269 static void s_wrpkt_defer(Ssh ssh)
1272 len = s_wrpkt_prepare(ssh);
1273 if (ssh->deferred_len + len > ssh->deferred_size) {
1274 ssh->deferred_size = ssh->deferred_len + len + 128;
1275 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1279 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1280 ssh->deferred_len += len;
1284 * Construct a packet with the specified contents.
1286 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1288 unsigned char *p, *argp, argchar;
1289 unsigned long argint;
1290 int pktlen, argtype, arglen;
1294 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1297 (void) va_arg(ap1, int);
1301 (void) va_arg(ap1, int);
1305 (void) va_arg(ap1, unsigned char *);
1306 arglen = va_arg(ap1, int);
1310 argp = va_arg(ap1, unsigned char *);
1311 arglen = strlen((char *)argp);
1312 pktlen += 4 + arglen;
1315 bn = va_arg(ap1, Bignum);
1316 pktlen += ssh1_bignum_length(bn);
1323 s_wrpkt_start(ssh, pkttype, pktlen);
1324 p = ssh->pktout.body;
1326 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1329 argint = va_arg(ap2, int);
1330 PUT_32BIT(p, argint);
1334 argchar = (unsigned char) va_arg(ap2, int);
1339 argp = va_arg(ap2, unsigned char *);
1340 arglen = va_arg(ap2, int);
1341 memcpy(p, argp, arglen);
1345 argp = va_arg(ap2, unsigned char *);
1346 arglen = strlen((char *)argp);
1347 PUT_32BIT(p, arglen);
1348 memcpy(p + 4, argp, arglen);
1352 bn = va_arg(ap2, Bignum);
1353 p += ssh1_write_bignum(p, bn);
1359 static void send_packet(Ssh ssh, int pkttype, ...)
1362 va_start(ap1, pkttype);
1363 va_start(ap2, pkttype);
1364 construct_packet(ssh, pkttype, ap1, ap2);
1368 static void defer_packet(Ssh ssh, int pkttype, ...)
1371 va_start(ap1, pkttype);
1372 va_start(ap2, pkttype);
1373 construct_packet(ssh, pkttype, ap1, ap2);
1377 static int ssh_versioncmp(char *a, char *b)
1380 unsigned long av, bv;
1382 av = strtoul(a, &ae, 10);
1383 bv = strtoul(b, &be, 10);
1385 return (av < bv ? -1 : +1);
1390 av = strtoul(ae, &ae, 10);
1391 bv = strtoul(be, &be, 10);
1393 return (av < bv ? -1 : +1);
1398 * Utility routines for putting an SSH-protocol `string' and
1399 * `uint32' into a SHA state.
1402 static void sha_string(SHA_State * s, void *str, int len)
1404 unsigned char lenblk[4];
1405 PUT_32BIT(lenblk, len);
1406 SHA_Bytes(s, lenblk, 4);
1407 SHA_Bytes(s, str, len);
1410 static void sha_uint32(SHA_State * s, unsigned i)
1412 unsigned char intblk[4];
1413 PUT_32BIT(intblk, i);
1414 SHA_Bytes(s, intblk, 4);
1418 * SSH2 packet construction functions.
1420 static void ssh2_pkt_ensure(Ssh ssh, int length)
1422 if (ssh->pktout.maxlen < length) {
1423 ssh->pktout.maxlen = length + 256;
1424 ssh->pktout.data = sresize(ssh->pktout.data,
1425 ssh->pktout.maxlen + APIEXTRA,
1427 if (!ssh->pktout.data)
1428 fatalbox("Out of memory");
1431 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1433 ssh->pktout.length += len;
1434 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1435 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1437 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1439 ssh2_pkt_adddata(ssh, &byte, 1);
1441 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1443 ssh->pktout.length = 5;
1444 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1446 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1448 ssh2_pkt_adddata(ssh, &value, 1);
1450 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1453 PUT_32BIT(x, value);
1454 ssh2_pkt_adddata(ssh, x, 4);
1456 static void ssh2_pkt_addstring_start(Ssh ssh)
1458 ssh2_pkt_adduint32(ssh, 0);
1459 ssh->pktout.savedpos = ssh->pktout.length;
1461 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1463 ssh2_pkt_adddata(ssh, data, strlen(data));
1464 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1465 ssh->pktout.length - ssh->pktout.savedpos);
1467 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1469 ssh2_pkt_adddata(ssh, data, len);
1470 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1471 ssh->pktout.length - ssh->pktout.savedpos);
1473 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1475 ssh2_pkt_addstring_start(ssh);
1476 ssh2_pkt_addstring_str(ssh, data);
1478 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1481 int i, n = (bignum_bitcount(b) + 7) / 8;
1482 p = snewn(n + 1, unsigned char);
1484 fatalbox("out of memory");
1486 for (i = 1; i <= n; i++)
1487 p[i] = bignum_byte(b, n - i);
1489 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1491 memmove(p, p + i, n + 1 - i);
1495 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1499 p = ssh2_mpint_fmt(b, &len);
1500 ssh2_pkt_addstring_start(ssh);
1501 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1506 * Construct an SSH2 final-form packet: compress it, encrypt it,
1507 * put the MAC on it. Final packet, ready to be sent, is stored in
1508 * ssh->pktout.data. Total length is returned.
1510 static int ssh2_pkt_construct(Ssh ssh)
1512 int cipherblk, maclen, padding, i;
1515 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1516 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1517 ssh->pktout.data + 6, ssh->pktout.length - 6);
1520 * Compress packet payload.
1523 unsigned char *newpayload;
1526 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1527 ssh->pktout.length - 5,
1528 &newpayload, &newlen)) {
1529 ssh->pktout.length = 5;
1530 ssh2_pkt_adddata(ssh, newpayload, newlen);
1536 * Add padding. At least four bytes, and must also bring total
1537 * length (minus MAC) up to a multiple of the block size.
1539 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1540 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1543 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1544 maclen = ssh->csmac ? ssh->csmac->len : 0;
1545 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1546 ssh->pktout.data[4] = padding;
1547 for (i = 0; i < padding; i++)
1548 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1549 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1551 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1552 ssh->pktout.length + padding,
1553 ssh->v2_outgoing_sequence);
1554 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1557 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1558 ssh->pktout.data, ssh->pktout.length + padding);
1560 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1561 return ssh->pktout.length + padding + maclen;
1565 * Construct and send an SSH2 packet immediately.
1567 static void ssh2_pkt_send(Ssh ssh)
1571 len = ssh2_pkt_construct(ssh);
1572 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1573 if (backlog > SSH_MAX_BACKLOG)
1574 ssh_throttle_all(ssh, 1, backlog);
1578 * Construct an SSH2 packet and add it to a deferred data block.
1579 * Useful for sending multiple packets in a single sk_write() call,
1580 * to prevent a traffic-analysing listener from being able to work
1581 * out the length of any particular packet (such as the password
1584 * Note that because SSH2 sequence-numbers its packets, this can
1585 * NOT be used as an m4-style `defer' allowing packets to be
1586 * constructed in one order and sent in another.
1588 static void ssh2_pkt_defer(Ssh ssh)
1590 int len = ssh2_pkt_construct(ssh);
1591 if (ssh->deferred_len + len > ssh->deferred_size) {
1592 ssh->deferred_size = ssh->deferred_len + len + 128;
1593 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1597 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1598 ssh->deferred_len += len;
1602 * Send the whole deferred data block constructed by
1603 * ssh2_pkt_defer() or SSH1's defer_packet().
1605 static void ssh_pkt_defersend(Ssh ssh)
1608 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1610 ssh->deferred_len = ssh->deferred_size = 0;
1611 sfree(ssh->deferred_send_data);
1612 ssh->deferred_send_data = NULL;
1613 if (backlog > SSH_MAX_BACKLOG)
1614 ssh_throttle_all(ssh, 1, backlog);
1618 void bndebug(char *string, Bignum b)
1622 p = ssh2_mpint_fmt(b, &len);
1623 debug(("%s", string));
1624 for (i = 0; i < len; i++)
1625 debug((" %02x", p[i]));
1631 static void sha_mpint(SHA_State * s, Bignum b)
1635 p = ssh2_mpint_fmt(b, &len);
1636 sha_string(s, p, len);
1641 * SSH2 packet decode functions.
1643 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1645 unsigned long value;
1646 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1647 return 0; /* arrgh, no way to decline (FIXME?) */
1648 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1649 ssh->pktin.savedpos += 4;
1652 static int ssh2_pkt_getbool(Ssh ssh)
1654 unsigned long value;
1655 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1656 return 0; /* arrgh, no way to decline (FIXME?) */
1657 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1658 ssh->pktin.savedpos++;
1661 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1666 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1668 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1672 ssh->pktin.savedpos += 4;
1673 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1675 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1676 ssh->pktin.savedpos += *length;
1678 static Bignum ssh2_pkt_getmp(Ssh ssh)
1684 ssh2_pkt_getstring(ssh, &p, &length);
1688 bombout(("internal error: Can't handle negative mpints"));
1691 b = bignum_from_bytes((unsigned char *)p, length);
1696 * Helper function to add an SSH2 signature blob to a packet.
1697 * Expects to be shown the public key blob as well as the signature
1698 * blob. Normally works just like ssh2_pkt_addstring, but will
1699 * fiddle with the signature packet if necessary for
1700 * BUG_SSH2_RSA_PADDING.
1702 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1703 void *sigblob_v, int sigblob_len)
1705 unsigned char *pkblob = (unsigned char *)pkblob_v;
1706 unsigned char *sigblob = (unsigned char *)sigblob_v;
1708 /* dmemdump(pkblob, pkblob_len); */
1709 /* dmemdump(sigblob, sigblob_len); */
1712 * See if this is in fact an ssh-rsa signature and a buggy
1713 * server; otherwise we can just do this the easy way.
1715 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1716 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1717 int pos, len, siglen;
1720 * Find the byte length of the modulus.
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1725 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1726 pos += 4; /* find modulus itself */
1727 while (len > 0 && pkblob[pos] == 0)
1729 /* debug(("modulus length is %d\n", len)); */
1732 * Now find the signature integer.
1734 pos = 4+7; /* skip over "ssh-rsa" */
1735 siglen = GET_32BIT(sigblob+pos);
1736 /* debug(("signature length is %d\n", siglen)); */
1738 if (len != siglen) {
1739 unsigned char newlen[4];
1740 ssh2_pkt_addstring_start(ssh);
1741 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1742 /* dmemdump(sigblob, pos); */
1743 pos += 4; /* point to start of actual sig */
1744 PUT_32BIT(newlen, len);
1745 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1746 /* dmemdump(newlen, 4); */
1748 while (len-- > siglen) {
1749 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1750 /* dmemdump(newlen, 1); */
1752 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1753 /* dmemdump(sigblob+pos, siglen); */
1757 /* Otherwise fall through and do it the easy way. */
1760 ssh2_pkt_addstring_start(ssh);
1761 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1765 * Examine the remote side's version string and compare it against
1766 * a list of known buggy implementations.
1768 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1770 char *imp; /* pointer to implementation part */
1772 imp += strcspn(imp, "-");
1774 imp += strcspn(imp, "-");
1777 ssh->remote_bugs = 0;
1779 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1780 (ssh->cfg.sshbug_ignore1 == AUTO &&
1781 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1782 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1783 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1784 !strcmp(imp, "OSU_1.4alpha3")))) {
1786 * These versions don't support SSH1_MSG_IGNORE, so we have
1787 * to use a different defence against password length
1790 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1791 logevent("We believe remote version has SSH1 ignore bug");
1794 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1796 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1798 * These versions need a plain password sent; they can't
1799 * handle having a null and a random length of data after
1802 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1803 logevent("We believe remote version needs a plain SSH1 password");
1806 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1807 (ssh->cfg.sshbug_rsa1 == AUTO &&
1808 (!strcmp(imp, "Cisco-1.25")))) {
1810 * These versions apparently have no clue whatever about
1811 * RSA authentication and will panic and die if they see
1812 * an AUTH_RSA message.
1814 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1815 logevent("We believe remote version can't handle RSA authentication");
1818 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_hmac2 == AUTO &&
1820 !wc_match("* VShell", imp) &&
1821 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1822 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1823 wc_match("2.1 *", imp)))) {
1825 * These versions have the HMAC bug.
1827 ssh->remote_bugs |= BUG_SSH2_HMAC;
1828 logevent("We believe remote version has SSH2 HMAC bug");
1831 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1832 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1833 !wc_match("* VShell", imp) &&
1834 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1836 * These versions have the key-derivation bug (failing to
1837 * include the literal shared secret in the hashes that
1838 * generate the keys).
1840 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1841 logevent("We believe remote version has SSH2 key-derivation bug");
1844 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1845 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1846 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1847 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1849 * These versions have the SSH2 RSA padding bug.
1851 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1852 logevent("We believe remote version has SSH2 RSA padding bug");
1855 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1856 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1857 wc_match("OpenSSH_2.[0-2]*", imp))) {
1859 * These versions have the SSH2 session-ID bug in
1860 * public-key authentication.
1862 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1863 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1866 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1868 * User specified the SSH2 DH GEX bug.
1870 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1871 logevent("We believe remote version has SSH2 DH group exchange bug");
1875 static int do_ssh_init(Ssh ssh, unsigned char c)
1877 struct do_ssh_init_state {
1885 crState(do_ssh_init_state);
1887 crBegin(ssh->do_ssh_init_crstate);
1889 /* Search for the string "SSH-" in the input. */
1892 static const int transS[] = { 1, 2, 2, 1 };
1893 static const int transH[] = { 0, 0, 3, 0 };
1894 static const int transminus[] = { 0, 0, 0, -1 };
1896 s->i = transS[s->i];
1898 s->i = transH[s->i];
1900 s->i = transminus[s->i];
1905 crReturn(1); /* get another character */
1909 s->vstring = snewn(s->vstrsize, char);
1910 strcpy(s->vstring, "SSH-");
1914 crReturn(1); /* get another char */
1915 if (s->vslen >= s->vstrsize - 1) {
1917 s->vstring = sresize(s->vstring, s->vstrsize, char);
1919 s->vstring[s->vslen++] = c;
1922 s->version[s->i] = '\0';
1924 } else if (s->i < sizeof(s->version) - 1)
1925 s->version[s->i++] = c;
1926 } else if (c == '\012')
1930 ssh->agentfwd_enabled = FALSE;
1931 ssh->rdpkt2_state.incoming_sequence = 0;
1933 s->vstring[s->vslen] = 0;
1934 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1937 vlog = snewn(20 + s->vslen, char);
1938 sprintf(vlog, "Server version: %s", s->vstring);
1942 ssh_detect_bugs(ssh, s->vstring);
1945 * Decide which SSH protocol version to support.
1948 /* Anything strictly below "2.0" means protocol 1 is supported. */
1949 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1950 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1951 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1953 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1954 bombout(("SSH protocol version 1 required by user but not provided by server"));
1957 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1958 bombout(("SSH protocol version 2 required by user but not provided by server"));
1962 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1966 char verstring[80], vlog[100];
1967 sprintf(verstring, "SSH-2.0-%s", sshver);
1968 SHA_Init(&ssh->exhashbase);
1970 * Hash our version string and their version string.
1972 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1973 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1974 sprintf(vlog, "We claim version: %s", verstring);
1976 strcat(verstring, "\012");
1977 logevent("Using SSH protocol version 2");
1978 sk_write(ssh->s, verstring, strlen(verstring));
1979 ssh->protocol = ssh2_protocol;
1981 ssh->s_rdpkt = ssh2_rdpkt;
1986 char verstring[80], vlog[100];
1987 sprintf(verstring, "SSH-%s-%s",
1988 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1990 sprintf(vlog, "We claim version: %s", verstring);
1992 strcat(verstring, "\012");
1994 logevent("Using SSH protocol version 1");
1995 sk_write(ssh->s, verstring, strlen(verstring));
1996 ssh->protocol = ssh1_protocol;
1998 ssh->s_rdpkt = ssh1_rdpkt;
2000 update_specials_menu(ssh->frontend);
2001 ssh->state = SSH_STATE_BEFORE_SIZE;
2008 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2010 crBegin(ssh->ssh_gotdata_crstate);
2013 * To begin with, feed the characters one by one to the
2014 * protocol initialisation / selection function do_ssh_init().
2015 * When that returns 0, we're done with the initial greeting
2016 * exchange and can move on to packet discipline.
2019 int ret; /* need not be kept across crReturn */
2021 crReturnV; /* more data please */
2022 ret = do_ssh_init(ssh, *data);
2030 * We emerge from that loop when the initial negotiation is
2031 * over and we have selected an s_rdpkt function. Now pass
2032 * everything to s_rdpkt, and then pass the resulting packets
2033 * to the proper protocol handler.
2038 while (datalen > 0) {
2039 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2040 if (ssh->state == SSH_STATE_CLOSED) {
2043 ssh->protocol(ssh, NULL, 0, 1);
2044 if (ssh->state == SSH_STATE_CLOSED) {
2054 static void ssh_do_close(Ssh ssh)
2057 struct ssh_channel *c;
2059 ssh->state = SSH_STATE_CLOSED;
2065 * Now we must shut down any port and X forwardings going
2066 * through this connection.
2068 if (ssh->channels) {
2069 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2072 x11_close(c->u.x11.s);
2075 pfd_close(c->u.pfd.s);
2078 del234(ssh->channels, c);
2079 if (ssh->version == 2)
2080 bufchain_clear(&c->v.v2.outbuffer);
2086 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2089 Ssh ssh = (Ssh) plug;
2092 /* A socket error has occurred. */
2093 logevent(error_msg);
2094 connection_fatal(ssh->frontend, "%s", error_msg);
2096 /* Otherwise, the remote side closed the connection normally. */
2101 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2103 Ssh ssh = (Ssh) plug;
2104 ssh_gotdata(ssh, (unsigned char *)data, len);
2105 if (ssh->state == SSH_STATE_CLOSED) {
2112 static void ssh_sent(Plug plug, int bufsize)
2114 Ssh ssh = (Ssh) plug;
2116 * If the send backlog on the SSH socket itself clears, we
2117 * should unthrottle the whole world if it was throttled.
2119 if (bufsize < SSH_MAX_BACKLOG)
2120 ssh_throttle_all(ssh, 0, bufsize);
2124 * Connect to specified host and port.
2125 * Returns an error message, or NULL on success.
2126 * Also places the canonical host name into `realhost'. It must be
2127 * freed by the caller.
2129 static const char *connect_to_host(Ssh ssh, char *host, int port,
2130 char **realhost, int nodelay)
2132 static const struct plug_function_table fn_table = {
2142 ssh->savedhost = snewn(1 + strlen(host), char);
2143 if (!ssh->savedhost)
2144 fatalbox("Out of memory");
2145 strcpy(ssh->savedhost, host);
2148 port = 22; /* default ssh port */
2149 ssh->savedport = port;
2154 logeventf(ssh, "Looking up host \"%s\"", host);
2155 addr = name_lookup(host, port, realhost, &ssh->cfg);
2156 if ((err = sk_addr_error(addr)) != NULL) {
2166 sk_getaddr(addr, addrbuf, 100);
2167 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2169 ssh->fn = &fn_table;
2170 ssh->s = new_connection(addr, *realhost, port,
2171 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2172 if ((err = sk_socket_error(ssh->s)) != NULL) {
2181 * Throttle or unthrottle the SSH connection.
2183 static void ssh1_throttle(Ssh ssh, int adjust)
2185 int old_count = ssh->v1_throttle_count;
2186 ssh->v1_throttle_count += adjust;
2187 assert(ssh->v1_throttle_count >= 0);
2188 if (ssh->v1_throttle_count && !old_count) {
2189 sk_set_frozen(ssh->s, 1);
2190 } else if (!ssh->v1_throttle_count && old_count) {
2191 sk_set_frozen(ssh->s, 0);
2196 * Throttle or unthrottle _all_ local data streams (for when sends
2197 * on the SSH connection itself back up).
2199 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2202 struct ssh_channel *c;
2204 if (enable == ssh->throttled_all)
2206 ssh->throttled_all = enable;
2207 ssh->overall_bufsize = bufsize;
2210 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2212 case CHAN_MAINSESSION:
2214 * This is treated separately, outside the switch.
2218 x11_override_throttle(c->u.x11.s, enable);
2221 /* Agent channels require no buffer management. */
2224 pfd_override_throttle(c->u.pfd.s, enable);
2231 * Username and password input, abstracted off into routines
2232 * reusable in several places - even between SSH1 and SSH2.
2235 /* Set up a username or password input loop on a given buffer. */
2236 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2238 ssh->userpass_input_buffer = buffer;
2239 ssh->userpass_input_buflen = buflen;
2240 ssh->userpass_input_bufpos = 0;
2241 ssh->userpass_input_echo = echo;
2245 * Process some terminal data in the course of username/password
2246 * input. Returns >0 for success (line of input returned in
2247 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2248 * for inconclusive (keep waiting for more input please).
2250 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2255 switch (c = *in++) {
2258 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2259 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2264 if (ssh->userpass_input_bufpos > 0) {
2265 if (ssh->userpass_input_echo)
2266 c_write_str(ssh, "\b \b");
2267 ssh->userpass_input_bufpos--;
2272 while (ssh->userpass_input_bufpos > 0) {
2273 if (ssh->userpass_input_echo)
2274 c_write_str(ssh, "\b \b");
2275 ssh->userpass_input_bufpos--;
2284 * This simplistic check for printability is disabled
2285 * when we're doing password input, because some people
2286 * have control characters in their passwords.o
2288 if ((!ssh->userpass_input_echo ||
2289 (c >= ' ' && c <= '~') ||
2290 ((unsigned char) c >= 160))
2291 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2292 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2293 if (ssh->userpass_input_echo)
2294 c_write(ssh, &c, 1);
2302 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2304 Ssh ssh = (Ssh) sshv;
2306 ssh->agent_response = reply;
2307 ssh->agent_response_len = replylen;
2309 if (ssh->version == 1)
2310 do_ssh1_login(ssh, NULL, -1, 0);
2312 do_ssh2_authconn(ssh, NULL, -1, 0);
2315 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2317 struct ssh_channel *c = (struct ssh_channel *)cv;
2319 void *sentreply = reply;
2322 /* Fake SSH_AGENT_FAILURE. */
2323 sentreply = "\0\0\0\1\5";
2326 if (ssh->version == 2) {
2327 ssh2_add_channel_data(c, sentreply, replylen);
2330 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2331 PKT_INT, c->remoteid,
2333 PKT_DATA, sentreply, replylen,
2341 * Handle the key exchange and user authentication phases.
2343 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2346 unsigned char cookie[8];
2347 struct RSAKey servkey, hostkey;
2348 struct MD5Context md5c;
2349 struct do_ssh1_login_state {
2351 unsigned char *rsabuf, *keystr1, *keystr2;
2352 unsigned long supported_ciphers_mask, supported_auths_mask;
2353 int tried_publickey, tried_agent;
2354 int tis_auth_refused, ccard_auth_refused;
2355 unsigned char session_id[16];
2358 void *publickey_blob;
2359 int publickey_bloblen;
2365 unsigned char request[5], *response, *p;
2374 crState(do_ssh1_login_state);
2376 crBegin(ssh->do_ssh1_login_crstate);
2381 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2382 bombout(("Public key packet not received"));
2386 logevent("Received public keys");
2388 memcpy(cookie, ssh->pktin.body, 8);
2390 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2391 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2394 * Log the host key fingerprint.
2398 logevent("Host key fingerprint is:");
2399 strcpy(logmsg, " ");
2400 hostkey.comment = NULL;
2401 rsa_fingerprint(logmsg + strlen(logmsg),
2402 sizeof(logmsg) - strlen(logmsg), &hostkey);
2406 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2407 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2408 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2410 ssh->v1_local_protoflags =
2411 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2412 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2415 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2416 MD5Update(&md5c, s->keystr1, servkey.bytes);
2417 MD5Update(&md5c, ssh->pktin.body, 8);
2418 MD5Final(s->session_id, &md5c);
2420 for (i = 0; i < 32; i++)
2421 ssh->session_key[i] = random_byte();
2423 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2425 s->rsabuf = snewn(s->len, unsigned char);
2427 fatalbox("Out of memory");
2430 * Verify the host key.
2434 * First format the key into a string.
2436 int len = rsastr_len(&hostkey);
2437 char fingerprint[100];
2438 char *keystr = snewn(len, char);
2440 fatalbox("Out of memory");
2441 rsastr_fmt(keystr, &hostkey);
2442 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2443 verify_ssh_host_key(ssh->frontend,
2444 ssh->savedhost, ssh->savedport, "rsa", keystr,
2449 for (i = 0; i < 32; i++) {
2450 s->rsabuf[i] = ssh->session_key[i];
2452 s->rsabuf[i] ^= s->session_id[i];
2455 if (hostkey.bytes > servkey.bytes) {
2456 rsaencrypt(s->rsabuf, 32, &servkey);
2457 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2459 rsaencrypt(s->rsabuf, 32, &hostkey);
2460 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2463 logevent("Encrypted session key");
2466 int cipher_chosen = 0, warn = 0;
2467 char *cipher_string = NULL;
2469 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2470 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2471 if (next_cipher == CIPHER_WARN) {
2472 /* If/when we choose a cipher, warn about it */
2474 } else if (next_cipher == CIPHER_AES) {
2475 /* XXX Probably don't need to mention this. */
2476 logevent("AES not supported in SSH1, skipping");
2478 switch (next_cipher) {
2479 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2480 cipher_string = "3DES"; break;
2481 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2482 cipher_string = "Blowfish"; break;
2483 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2484 cipher_string = "single-DES"; break;
2486 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2490 if (!cipher_chosen) {
2491 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2492 bombout(("Server violates SSH 1 protocol by not "
2493 "supporting 3DES encryption"));
2495 /* shouldn't happen */
2496 bombout(("No supported ciphers found"));
2500 /* Warn about chosen cipher if necessary. */
2502 askcipher(ssh->frontend, cipher_string, 0);
2505 switch (s->cipher_type) {
2506 case SSH_CIPHER_3DES:
2507 logevent("Using 3DES encryption");
2509 case SSH_CIPHER_DES:
2510 logevent("Using single-DES encryption");
2512 case SSH_CIPHER_BLOWFISH:
2513 logevent("Using Blowfish encryption");
2517 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2518 PKT_CHAR, s->cipher_type,
2519 PKT_DATA, cookie, 8,
2520 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2521 PKT_DATA, s->rsabuf, s->len,
2522 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2524 logevent("Trying to enable encryption...");
2528 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2529 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2531 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2532 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2533 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2535 ssh->crcda_ctx = crcda_make_context();
2536 logevent("Installing CRC compensation attack detector");
2540 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2541 bombout(("Encryption not successfully enabled"));
2545 logevent("Successfully started encryption");
2549 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2550 if (ssh_get_line && !ssh_getline_pw_only) {
2551 if (!ssh_get_line("login as: ",
2552 s->username, sizeof(s->username), FALSE)) {
2554 * get_line failed to get a username.
2557 logevent("No username provided. Abandoning session.");
2558 ssh_closing((Plug)ssh, NULL, 0, 0);
2562 int ret; /* need not be kept over crReturn */
2563 c_write_str(ssh, "login as: ");
2566 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2568 crWaitUntil(!ispkt);
2569 ret = process_userpass_input(ssh, in, inlen);
2573 c_write_str(ssh, "\r\n");
2576 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2577 s->username[sizeof(s->username)-1] = '\0';
2580 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2582 char userlog[22 + sizeof(s->username)];
2583 sprintf(userlog, "Sent username \"%s\"", s->username);
2585 if (flags & FLAG_INTERACTIVE &&
2586 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2587 strcat(userlog, "\r\n");
2588 c_write_str(ssh, userlog);
2595 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2596 /* We must not attempt PK auth. Pretend we've already tried it. */
2597 s->tried_publickey = s->tried_agent = 1;
2599 s->tried_publickey = s->tried_agent = 0;
2601 s->tis_auth_refused = s->ccard_auth_refused = 0;
2602 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2603 if (!filename_is_null(ssh->cfg.keyfile)) {
2604 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2605 &s->publickey_blob, &s->publickey_bloblen, NULL))
2606 s->publickey_blob = NULL;
2608 s->publickey_blob = NULL;
2610 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2611 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2613 if (agent_exists() && !s->tried_agent) {
2615 * Attempt RSA authentication using Pageant.
2621 logevent("Pageant is running. Requesting keys.");
2623 /* Request the keys held by the agent. */
2624 PUT_32BIT(s->request, 1);
2625 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2626 if (!agent_query(s->request, 5, &r, &s->responselen,
2627 ssh_agent_callback, ssh)) {
2631 bombout(("Unexpected data from server while waiting"
2632 " for agent response"));
2635 } while (ispkt || inlen > 0);
2636 r = ssh->agent_response;
2637 s->responselen = ssh->agent_response_len;
2639 s->response = (unsigned char *) r;
2640 if (s->response && s->responselen >= 5 &&
2641 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2642 s->p = s->response + 5;
2643 s->nkeys = GET_32BIT(s->p);
2647 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2650 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2653 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2656 if (s->publickey_blob &&
2657 !memcmp(s->p, s->publickey_blob,
2658 s->publickey_bloblen)) {
2659 logevent("This key matches configured key file");
2660 s->tried_publickey = 1;
2663 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2664 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2665 s->commentlen = GET_32BIT(s->p);
2667 s->commentp = (char *)s->p;
2668 s->p += s->commentlen;
2669 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2670 PKT_BIGNUM, s->key.modulus, PKT_END);
2672 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2673 logevent("Key refused");
2676 logevent("Received RSA challenge");
2677 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2679 char *agentreq, *q, *ret;
2682 len = 1 + 4; /* message type, bit count */
2683 len += ssh1_bignum_length(s->key.exponent);
2684 len += ssh1_bignum_length(s->key.modulus);
2685 len += ssh1_bignum_length(s->challenge);
2686 len += 16; /* session id */
2687 len += 4; /* response format */
2688 agentreq = snewn(4 + len, char);
2689 PUT_32BIT(agentreq, len);
2691 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2692 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2694 q += ssh1_write_bignum(q, s->key.exponent);
2695 q += ssh1_write_bignum(q, s->key.modulus);
2696 q += ssh1_write_bignum(q, s->challenge);
2697 memcpy(q, s->session_id, 16);
2699 PUT_32BIT(q, 1); /* response format */
2700 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2701 ssh_agent_callback, ssh)) {
2706 bombout(("Unexpected data from server"
2707 " while waiting for agent"
2711 } while (ispkt || inlen > 0);
2712 vret = ssh->agent_response;
2713 retlen = ssh->agent_response_len;
2718 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2719 logevent("Sending Pageant's response");
2720 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2721 PKT_DATA, ret + 5, 16,
2725 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2727 ("Pageant's response accepted");
2728 if (flags & FLAG_VERBOSE) {
2729 c_write_str(ssh, "Authenticated using"
2731 c_write(ssh, s->commentp,
2733 c_write_str(ssh, "\" from agent\r\n");
2738 ("Pageant's response not accepted");
2741 ("Pageant failed to answer challenge");
2745 logevent("No reply received from Pageant");
2748 freebn(s->key.exponent);
2749 freebn(s->key.modulus);
2750 freebn(s->challenge);
2758 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2759 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2761 if (ssh->cfg.try_tis_auth &&
2762 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2763 !s->tis_auth_refused) {
2764 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2765 logevent("Requested TIS authentication");
2766 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2768 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2769 logevent("TIS authentication declined");
2770 if (flags & FLAG_INTERACTIVE)
2771 c_write_str(ssh, "TIS authentication refused.\r\n");
2772 s->tis_auth_refused = 1;
2775 int challengelen = GET_32BIT(ssh->pktin.body);
2776 logevent("Received TIS challenge");
2777 if (challengelen > sizeof(s->prompt) - 1)
2778 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2779 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2780 /* Prompt heuristic comes from OpenSSH */
2781 strncpy(s->prompt + challengelen,
2782 memchr(s->prompt, '\n', challengelen) ?
2783 "": "\r\nResponse: ",
2784 (sizeof s->prompt) - challengelen);
2785 s->prompt[(sizeof s->prompt) - 1] = '\0';
2788 if (ssh->cfg.try_tis_auth &&
2789 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2790 !s->ccard_auth_refused) {
2791 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2792 logevent("Requested CryptoCard authentication");
2793 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2795 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2796 logevent("CryptoCard authentication declined");
2797 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2798 s->ccard_auth_refused = 1;
2801 int challengelen = GET_32BIT(ssh->pktin.body);
2802 logevent("Received CryptoCard challenge");
2803 if (challengelen > sizeof(s->prompt) - 1)
2804 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2805 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2806 strncpy(s->prompt + challengelen,
2807 memchr(s->prompt, '\n', challengelen) ?
2808 "" : "\r\nResponse: ",
2809 sizeof(s->prompt) - challengelen);
2810 s->prompt[sizeof(s->prompt) - 1] = '\0';
2813 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2814 sprintf(s->prompt, "%.90s@%.90s's password: ",
2815 s->username, ssh->savedhost);
2817 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2818 char *comment = NULL;
2821 if (flags & FLAG_VERBOSE)
2822 c_write_str(ssh, "Trying public key authentication.\r\n");
2823 logeventf(ssh, "Trying public key \"%s\"",
2824 filename_to_str(&ssh->cfg.keyfile));
2825 type = key_type(&ssh->cfg.keyfile);
2826 if (type != SSH_KEYTYPE_SSH1) {
2827 sprintf(msgbuf, "Key is of wrong type (%s)",
2828 key_type_to_str(type));
2830 c_write_str(ssh, msgbuf);
2831 c_write_str(ssh, "\r\n");
2832 s->tried_publickey = 1;
2835 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2836 if (flags & FLAG_VERBOSE)
2837 c_write_str(ssh, "No passphrase required.\r\n");
2840 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2845 * Show password prompt, having first obtained it via a TIS
2846 * or CryptoCard exchange if we're doing TIS or CryptoCard
2850 if (!ssh_get_line(s->prompt, s->password,
2851 sizeof(s->password), TRUE)) {
2853 * get_line failed to get a password (for example
2854 * because one was supplied on the command line
2855 * which has already failed to work). Terminate.
2857 send_packet(ssh, SSH1_MSG_DISCONNECT,
2858 PKT_STR, "No more passwords available to try",
2860 logevent("Unable to authenticate");
2861 connection_fatal(ssh->frontend, "Unable to authenticate");
2862 ssh_closing((Plug)ssh, NULL, 0, 0);
2866 /* Prompt may have come from server. We've munged it a bit, so
2867 * we know it to be zero-terminated at least once. */
2868 int ret; /* need not be saved over crReturn */
2869 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2872 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2874 crWaitUntil(!ispkt);
2875 ret = process_userpass_input(ssh, in, inlen);
2879 c_write_str(ssh, "\r\n");
2883 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2885 * Try public key authentication with the specified
2888 s->tried_publickey = 1;
2891 const char *error = NULL;
2892 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
2895 c_write_str(ssh, "Couldn't load private key from ");
2896 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2897 c_write_str(ssh, " (");
2898 c_write_str(ssh, error);
2899 c_write_str(ssh, ").\r\n");
2900 continue; /* go and try password */
2903 c_write_str(ssh, "Wrong passphrase.\r\n");
2904 s->tried_publickey = 0;
2905 continue; /* try again */
2910 * Send a public key attempt.
2912 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2913 PKT_BIGNUM, s->key.modulus, PKT_END);
2916 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2917 c_write_str(ssh, "Server refused our public key.\r\n");
2918 continue; /* go and try password */
2920 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2921 bombout(("Bizarre response to offer of public key"));
2927 unsigned char buffer[32];
2928 Bignum challenge, response;
2930 ssh1_read_bignum(ssh->pktin.body, &challenge);
2931 response = rsadecrypt(challenge, &s->key);
2932 freebn(s->key.private_exponent);/* burn the evidence */
2934 for (i = 0; i < 32; i++) {
2935 buffer[i] = bignum_byte(response, 31 - i);
2939 MD5Update(&md5c, buffer, 32);
2940 MD5Update(&md5c, s->session_id, 16);
2941 MD5Final(buffer, &md5c);
2943 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2944 PKT_DATA, buffer, 16, PKT_END);
2951 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2952 if (flags & FLAG_VERBOSE)
2953 c_write_str(ssh, "Failed to authenticate with"
2954 " our public key.\r\n");
2955 continue; /* go and try password */
2956 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2957 bombout(("Bizarre response to RSA authentication response"));
2961 break; /* we're through! */
2963 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2965 * Defence against traffic analysis: we send a
2966 * whole bunch of packets containing strings of
2967 * different lengths. One of these strings is the
2968 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2969 * The others are all random data in
2970 * SSH1_MSG_IGNORE packets. This way a passive
2971 * listener can't tell which is the password, and
2972 * hence can't deduce the password length.
2974 * Anybody with a password length greater than 16
2975 * bytes is going to have enough entropy in their
2976 * password that a listener won't find it _that_
2977 * much help to know how long it is. So what we'll
2980 * - if password length < 16, we send 15 packets
2981 * containing string lengths 1 through 15
2983 * - otherwise, we let N be the nearest multiple
2984 * of 8 below the password length, and send 8
2985 * packets containing string lengths N through
2986 * N+7. This won't obscure the order of
2987 * magnitude of the password length, but it will
2988 * introduce a bit of extra uncertainty.
2990 * A few servers (the old 1.2.18 through 1.2.22)
2991 * can't deal with SSH1_MSG_IGNORE. For these
2992 * servers, we need an alternative defence. We make
2993 * use of the fact that the password is interpreted
2994 * as a C string: so we can append a NUL, then some
2997 * One server (a Cisco one) can deal with neither
2998 * SSH1_MSG_IGNORE _nor_ a padded password string.
2999 * For this server we are left with no defences
3000 * against password length sniffing.
3002 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3004 * The server can deal with SSH1_MSG_IGNORE, so
3005 * we can use the primary defence.
3007 int bottom, top, pwlen, i;
3010 pwlen = strlen(s->password);
3012 bottom = 0; /* zero length passwords are OK! :-) */
3015 bottom = pwlen & ~7;
3019 assert(pwlen >= bottom && pwlen <= top);
3021 randomstr = snewn(top + 1, char);
3023 for (i = bottom; i <= top; i++) {
3025 defer_packet(ssh, s->pwpkt_type,
3026 PKT_STR, s->password, PKT_END);
3028 for (j = 0; j < i; j++) {
3030 randomstr[j] = random_byte();
3031 } while (randomstr[j] == '\0');
3033 randomstr[i] = '\0';
3034 defer_packet(ssh, SSH1_MSG_IGNORE,
3035 PKT_STR, randomstr, PKT_END);
3038 logevent("Sending password with camouflage packets");
3039 ssh_pkt_defersend(ssh);
3041 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3043 * The server can't deal with SSH1_MSG_IGNORE
3044 * but can deal with padded passwords, so we
3045 * can use the secondary defence.
3051 len = strlen(s->password);
3052 if (len < sizeof(string)) {
3054 strcpy(string, s->password);
3055 len++; /* cover the zero byte */
3056 while (len < sizeof(string)) {
3057 string[len++] = (char) random_byte();
3062 logevent("Sending length-padded password");
3063 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3064 PKT_DATA, ss, len, PKT_END);
3067 * The server has _both_
3068 * BUG_CHOKES_ON_SSH1_IGNORE and
3069 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3070 * therefore nothing we can do.
3073 len = strlen(s->password);
3074 logevent("Sending unpadded password");
3075 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3076 PKT_DATA, s->password, len, PKT_END);
3079 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
3082 logevent("Sent password");
3083 memset(s->password, 0, strlen(s->password));
3085 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3086 if (flags & FLAG_VERBOSE)
3087 c_write_str(ssh, "Access denied\r\n");
3088 logevent("Authentication refused");
3089 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3090 bombout(("Strange packet received, type %d", ssh->pktin.type));
3095 logevent("Authentication successful");
3100 void sshfwd_close(struct ssh_channel *c)
3104 if (ssh->state != SSH_STATE_SESSION) {
3105 assert(ssh->state == SSH_STATE_CLOSED);
3109 if (c && !c->closes) {
3111 * If the channel's remoteid is -1, we have sent
3112 * CHANNEL_OPEN for this channel, but it hasn't even been
3113 * acknowledged by the server. So we must set a close flag
3114 * on it now, and then when the server acks the channel
3115 * open, we can close it then.
3117 if (((int)c->remoteid) != -1) {
3118 if (ssh->version == 1) {
3119 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3122 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3123 ssh2_pkt_adduint32(ssh, c->remoteid);
3127 c->closes = 1; /* sent MSG_CLOSE */
3128 if (c->type == CHAN_X11) {
3130 logevent("Forwarded X11 connection terminated");
3131 } else if (c->type == CHAN_SOCKDATA ||
3132 c->type == CHAN_SOCKDATA_DORMANT) {
3134 logevent("Forwarded port closed");
3139 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3143 if (ssh->state != SSH_STATE_SESSION) {
3144 assert(ssh->state == SSH_STATE_CLOSED);
3148 if (ssh->version == 1) {
3149 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3150 PKT_INT, c->remoteid,
3151 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3153 * In SSH1 we can return 0 here - implying that forwarded
3154 * connections are never individually throttled - because
3155 * the only circumstance that can cause throttling will be
3156 * the whole SSH connection backing up, in which case
3157 * _everything_ will be throttled as a whole.
3161 ssh2_add_channel_data(c, buf, len);
3162 return ssh2_try_send(c);
3166 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3170 if (ssh->state != SSH_STATE_SESSION) {
3171 assert(ssh->state == SSH_STATE_CLOSED);
3175 if (ssh->version == 1) {
3176 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3177 c->v.v1.throttling = 0;
3178 ssh1_throttle(ssh, -1);
3181 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3185 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3187 crBegin(ssh->ssh1_protocol_crstate);
3191 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3194 if (ssh->state == SSH_STATE_CLOSED)
3197 if (ssh->cfg.agentfwd && agent_exists()) {
3198 logevent("Requesting agent forwarding");
3199 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3203 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3204 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3205 bombout(("Protocol confusion"));
3207 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3208 logevent("Agent forwarding refused");
3210 logevent("Agent forwarding enabled");
3211 ssh->agentfwd_enabled = TRUE;
3215 if (ssh->cfg.x11_forward) {
3216 char proto[20], data[64];
3217 logevent("Requesting X11 forwarding");
3218 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3219 data, sizeof(data), ssh->cfg.x11_auth);
3220 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3221 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3222 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3223 PKT_STR, proto, PKT_STR, data,
3224 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3227 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3228 PKT_STR, proto, PKT_STR, data, PKT_END);
3233 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3234 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3235 bombout(("Protocol confusion"));
3237 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3238 logevent("X11 forwarding refused");
3240 logevent("X11 forwarding enabled");
3241 ssh->X11_fwd_enabled = TRUE;
3248 int sport,dport,sserv,dserv;
3249 char sports[256], dports[256], saddr[256], host[256];
3251 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3252 /* Add port forwardings. */
3253 ssh->portfwd_strptr = ssh->cfg.portfwd;
3254 while (*ssh->portfwd_strptr) {
3255 type = *ssh->portfwd_strptr++;
3258 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3259 if (*ssh->portfwd_strptr == ':') {
3261 * We've seen a colon in the middle of the
3262 * source port number. This means that
3263 * everything we've seen until now is the
3264 * source _address_, so we'll move it into
3265 * saddr and start sports from the beginning
3268 ssh->portfwd_strptr++;
3270 strcpy(saddr, sports);
3273 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3277 if (*ssh->portfwd_strptr == '\t')
3278 ssh->portfwd_strptr++;
3280 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3281 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3284 if (*ssh->portfwd_strptr == ':')
3285 ssh->portfwd_strptr++;
3287 while (*ssh->portfwd_strptr) {
3288 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3291 ssh->portfwd_strptr++;
3292 dport = atoi(dports);
3296 dport = net_service_lookup(dports);
3298 logeventf(ssh, "Service lookup failed for"
3299 " destination port \"%s\"", dports);
3303 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3306 sport = atoi(sports);
3310 sport = net_service_lookup(sports);
3312 logeventf(ssh, "Service lookup failed for source"
3313 " port \"%s\"", sports);
3316 if (sport && dport) {
3318 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3319 sport, ssh, &ssh->cfg);
3320 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3321 " forwarding to %s:%.*s%.*s%d%.*s",
3322 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3323 (int)(*saddr?1:0), ":",
3324 (int)(sserv ? strlen(sports) : 0), sports,
3325 sserv, "(", sport, sserv, ")",
3327 (int)(dserv ? strlen(dports) : 0), dports,
3328 dserv, "(", dport, dserv, ")");
3329 } else if (type == 'D') {
3330 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3331 sport, ssh, &ssh->cfg);
3332 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3333 " doing SOCKS dynamic forwarding",
3334 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3335 (int)(*saddr?1:0), ":",
3336 (int)(sserv ? strlen(sports) : 0), sports,
3337 sserv, "(", sport, sserv, ")");
3339 struct ssh_rportfwd *pf;
3340 pf = snew(struct ssh_rportfwd);
3341 strcpy(pf->dhost, host);
3345 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3348 if (add234(ssh->rportfwds, pf) != pf) {
3350 "Duplicate remote port forwarding to %s:%d",
3354 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3355 " forward to %s:%.*s%.*s%d%.*s",
3356 (int)(sserv ? strlen(sports) : 0), sports,
3357 sserv, "(", sport, sserv, ")",
3359 (int)(dserv ? strlen(dports) : 0), dports,
3360 dserv, "(", dport, dserv, ")");
3361 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3369 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3370 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3371 bombout(("Protocol confusion"));
3373 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3374 c_write_str(ssh, "Server refused port"
3377 logevent("Remote port forwarding enabled");
3384 if (!ssh->cfg.nopty) {
3385 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3386 PKT_STR, ssh->cfg.termtype,
3387 PKT_INT, ssh->term_height,
3388 PKT_INT, ssh->term_width,
3389 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3390 ssh->state = SSH_STATE_INTERMED;
3394 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3395 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3396 bombout(("Protocol confusion"));
3398 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3399 c_write_str(ssh, "Server refused to allocate pty\r\n");
3400 ssh->editing = ssh->echoing = 1;
3402 logevent("Allocated pty");
3404 ssh->editing = ssh->echoing = 1;
3407 if (ssh->cfg.compression) {
3408 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3412 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3413 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3414 bombout(("Protocol confusion"));
3416 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3417 c_write_str(ssh, "Server refused to compress\r\n");
3419 logevent("Started compression");
3420 ssh->v1_compressing = TRUE;
3421 ssh->cs_comp_ctx = zlib_compress_init();
3422 logevent("Initialised zlib (RFC1950) compression");
3423 ssh->sc_comp_ctx = zlib_decompress_init();
3424 logevent("Initialised zlib (RFC1950) decompression");
3428 * Start the shell or command.
3430 * Special case: if the first-choice command is an SSH2
3431 * subsystem (hence not usable here) and the second choice
3432 * exists, we fall straight back to that.
3435 char *cmd = ssh->cfg.remote_cmd_ptr;
3437 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3438 cmd = ssh->cfg.remote_cmd_ptr2;
3439 ssh->fallback_cmd = TRUE;
3442 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3444 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3445 logevent("Started session");
3448 ssh->state = SSH_STATE_SESSION;
3449 if (ssh->size_needed)
3450 ssh_size(ssh, ssh->term_width, ssh->term_height);
3451 if (ssh->eof_needed)
3452 ssh_special(ssh, TS_EOF);
3455 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3457 ssh->channels = newtree234(ssh_channelcmp);
3461 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3462 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3463 long len = GET_32BIT(ssh->pktin.body);
3465 from_backend(ssh->frontend,
3466 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3467 (char *)(ssh->pktin.body) + 4, len);
3468 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3469 ssh->v1_stdout_throttling = 1;
3470 ssh1_throttle(ssh, +1);
3472 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3473 ssh_closing((Plug)ssh, NULL, 0, 0);
3474 logevent("Received disconnect request");
3476 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3477 /* Remote side is trying to open a channel to talk to our
3478 * X-Server. Give them back a local channel number. */
3479 struct ssh_channel *c;
3481 logevent("Received X11 connect request");
3482 /* Refuse if X11 forwarding is disabled. */
3483 if (!ssh->X11_fwd_enabled) {
3484 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3485 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3486 logevent("Rejected X11 connect request");
3488 c = snew(struct ssh_channel);
3491 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3492 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3493 logevent("opening X11 forward connection failed");
3495 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3496 PKT_INT, GET_32BIT(ssh->pktin.body),
3500 ("opening X11 forward connection succeeded");
3501 c->remoteid = GET_32BIT(ssh->pktin.body);
3502 c->localid = alloc_channel_id(ssh);
3504 c->v.v1.throttling = 0;
3505 c->type = CHAN_X11; /* identify channel type */
3506 add234(ssh->channels, c);
3507 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3508 PKT_INT, c->remoteid, PKT_INT,
3509 c->localid, PKT_END);
3510 logevent("Opened X11 forward channel");
3513 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3514 /* Remote side is trying to open a channel to talk to our
3515 * agent. Give them back a local channel number. */
3516 struct ssh_channel *c;
3518 /* Refuse if agent forwarding is disabled. */
3519 if (!ssh->agentfwd_enabled) {
3520 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3521 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3523 c = snew(struct ssh_channel);
3525 c->remoteid = GET_32BIT(ssh->pktin.body);
3526 c->localid = alloc_channel_id(ssh);
3528 c->v.v1.throttling = 0;
3529 c->type = CHAN_AGENT; /* identify channel type */
3530 c->u.a.lensofar = 0;
3531 add234(ssh->channels, c);
3532 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3533 PKT_INT, c->remoteid, PKT_INT, c->localid,
3536 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3537 /* Remote side is trying to open a channel to talk to a
3538 * forwarded port. Give them back a local channel number. */
3539 struct ssh_channel *c;
3540 struct ssh_rportfwd pf;
3542 char host[256], buf[1024];
3545 c = snew(struct ssh_channel);
3548 hostsize = GET_32BIT(ssh->pktin.body+4);
3549 for (h = host, p = (char *)(ssh->pktin.body+8);
3550 hostsize != 0; hostsize--) {
3551 if (h+1 < host+sizeof(host))
3556 port = GET_32BIT(p);
3558 strcpy(pf.dhost, host);
3561 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3562 sprintf(buf, "Rejected remote port open request for %s:%d",
3565 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3566 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3568 sprintf(buf, "Received remote port open request for %s:%d",
3571 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3574 sprintf(buf, "Port open failed: %s", e);
3577 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3578 PKT_INT, GET_32BIT(ssh->pktin.body),
3581 c->remoteid = GET_32BIT(ssh->pktin.body);
3582 c->localid = alloc_channel_id(ssh);
3584 c->v.v1.throttling = 0;
3585 c->type = CHAN_SOCKDATA; /* identify channel type */
3586 add234(ssh->channels, c);
3587 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3588 PKT_INT, c->remoteid, PKT_INT,
3589 c->localid, PKT_END);
3590 logevent("Forwarded port opened successfully");
3594 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3595 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3596 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3597 struct ssh_channel *c;
3599 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3600 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3601 c->remoteid = localid;
3602 c->type = CHAN_SOCKDATA;
3603 c->v.v1.throttling = 0;
3604 pfd_confirm(c->u.pfd.s);
3607 if (c && c->closes) {
3609 * We have a pending close on this channel,
3610 * which we decided on before the server acked
3611 * the channel open. So now we know the
3612 * remoteid, we can close it again.
3614 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3615 PKT_INT, c->remoteid, PKT_END);
3618 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3619 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3620 struct ssh_channel *c;
3622 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3623 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3624 logevent("Forwarded connection refused by server");
3625 pfd_close(c->u.pfd.s);
3626 del234(ssh->channels, c);
3630 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3631 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3632 /* Remote side closes a channel. */
3633 unsigned i = GET_32BIT(ssh->pktin.body);
3634 struct ssh_channel *c;
3635 c = find234(ssh->channels, &i, ssh_channelfind);
3636 if (c && ((int)c->remoteid) != -1) {
3639 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3641 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3642 logevent("Forwarded X11 connection terminated");
3643 assert(c->u.x11.s != NULL);
3644 x11_close(c->u.x11.s);
3647 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3648 logevent("Forwarded port closed");
3649 assert(c->u.pfd.s != NULL);
3650 pfd_close(c->u.pfd.s);
3654 c->closes |= (closetype << 2); /* seen this message */
3655 if (!(c->closes & closetype)) {
3656 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3658 c->closes |= closetype; /* sent it too */
3661 if (c->closes == 15) {
3662 del234(ssh->channels, c);
3666 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3667 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3668 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3672 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3673 /* Data sent down one of our channels. */
3674 int i = GET_32BIT(ssh->pktin.body);
3675 int len = GET_32BIT(ssh->pktin.body + 4);
3676 unsigned char *p = ssh->pktin.body + 8;
3677 struct ssh_channel *c;
3678 c = find234(ssh->channels, &i, ssh_channelfind);
3683 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3686 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3689 /* Data for an agent message. Buffer it. */
3691 if (c->u.a.lensofar < 4) {
3692 int l = min(4 - c->u.a.lensofar, len);
3693 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3697 c->u.a.lensofar += l;
3699 if (c->u.a.lensofar == 4) {
3701 4 + GET_32BIT(c->u.a.msglen);
3702 c->u.a.message = snewn(c->u.a.totallen,
3704 memcpy(c->u.a.message, c->u.a.msglen, 4);
3706 if (c->u.a.lensofar >= 4 && len > 0) {
3708 min(c->u.a.totallen - c->u.a.lensofar,
3710 memcpy(c->u.a.message + c->u.a.lensofar, p,
3714 c->u.a.lensofar += l;
3716 if (c->u.a.lensofar == c->u.a.totallen) {
3719 if (agent_query(c->u.a.message,
3722 ssh_agentf_callback, c))
3723 ssh_agentf_callback(c, reply, replylen);
3724 sfree(c->u.a.message);
3725 c->u.a.lensofar = 0;
3728 bufsize = 0; /* agent channels never back up */
3731 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3732 c->v.v1.throttling = 1;
3733 ssh1_throttle(ssh, +1);
3736 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3737 /* may be from EXEC_SHELL on some servers */
3738 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3739 /* may be from EXEC_SHELL on some servers
3740 * if no pty is available or in other odd cases. Ignore */
3741 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3743 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3744 sprintf(buf, "Server sent command exit status %d",
3747 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3749 * In case `helpful' firewalls or proxies tack
3750 * extra human-readable text on the end of the
3751 * session which we might mistake for another
3752 * encrypted packet, we close the session once
3753 * we've sent EXIT_CONFIRMATION.
3755 ssh_closing((Plug)ssh, NULL, 0, 0);
3758 bombout(("Strange packet received: type %d", ssh->pktin.type));
3763 int len = min(inlen, 512);
3764 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3765 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3776 * Utility routine for decoding comma-separated strings in KEXINIT.
3778 static int in_commasep_string(char *needle, char *haystack, int haylen)
3781 if (!needle || !haystack) /* protect against null pointers */
3783 needlen = strlen(needle);
3786 * Is it at the start of the string?
3788 if (haylen >= needlen && /* haystack is long enough */
3789 !memcmp(needle, haystack, needlen) && /* initial match */
3790 (haylen == needlen || haystack[needlen] == ',')
3791 /* either , or EOS follows */
3795 * If not, search for the next comma and resume after that.
3796 * If no comma found, terminate.
3798 while (haylen > 0 && *haystack != ',')
3799 haylen--, haystack++;
3802 haylen--, haystack++; /* skip over comma itself */
3807 * SSH2 key creation method.
3809 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3810 unsigned char *sessid, char chr,
3811 unsigned char *keyspace)
3814 /* First 20 bytes. */
3816 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3818 SHA_Bytes(&s, H, 20);
3819 SHA_Bytes(&s, &chr, 1);
3820 SHA_Bytes(&s, sessid, 20);
3821 SHA_Final(&s, keyspace);
3822 /* Next 20 bytes. */
3824 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3826 SHA_Bytes(&s, H, 20);
3827 SHA_Bytes(&s, keyspace, 20);
3828 SHA_Final(&s, keyspace + 20);
3832 * Handle the SSH2 transport layer.
3834 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3836 struct do_ssh2_transport_state {
3837 int nbits, pbits, warn;
3838 Bignum p, g, e, f, K;
3839 int kex_init_value, kex_reply_value;
3840 const struct ssh_mac **maclist;
3842 const struct ssh2_cipher *cscipher_tobe;
3843 const struct ssh2_cipher *sccipher_tobe;
3844 const struct ssh_mac *csmac_tobe;
3845 const struct ssh_mac *scmac_tobe;
3846 const struct ssh_compress *cscomp_tobe;
3847 const struct ssh_compress *sccomp_tobe;
3848 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3849 int hostkeylen, siglen;
3850 void *hkey; /* actual host key */
3851 unsigned char exchange_hash[20];
3852 int n_preferred_ciphers;
3853 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3854 const struct ssh_compress *preferred_comp;
3857 crState(do_ssh2_transport_state);
3859 crBegin(ssh->do_ssh2_transport_crstate);
3861 s->cscipher_tobe = s->sccipher_tobe = NULL;
3862 s->csmac_tobe = s->scmac_tobe = NULL;
3863 s->cscomp_tobe = s->sccomp_tobe = NULL;
3871 * Set up the preferred ciphers. (NULL => warn below here)
3873 s->n_preferred_ciphers = 0;
3874 for (i = 0; i < CIPHER_MAX; i++) {
3875 switch (ssh->cfg.ssh_cipherlist[i]) {
3876 case CIPHER_BLOWFISH:
3877 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3880 if (ssh->cfg.ssh2_des_cbc) {
3881 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3885 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3888 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3891 /* Flag for later. Don't bother if it's the last in
3893 if (i < CIPHER_MAX - 1) {
3894 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3902 * Set up preferred compression.
3904 if (ssh->cfg.compression)
3905 s->preferred_comp = &ssh_zlib;
3907 s->preferred_comp = &ssh_comp_none;
3910 * Be prepared to work around the buggy MAC problem.
3912 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3913 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3915 s->maclist = macs, s->nmacs = lenof(macs);
3919 int i, j, cipherstr_started;
3922 * Construct and send our key exchange packet.
3924 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3925 for (i = 0; i < 16; i++)
3926 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3927 /* List key exchange algorithms. */
3928 ssh2_pkt_addstring_start(ssh);
3929 for (i = 0; i < lenof(kex_algs); i++) {
3930 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3931 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3933 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3934 if (i < lenof(kex_algs) - 1)
3935 ssh2_pkt_addstring_str(ssh, ",");
3937 /* List server host key algorithms. */
3938 ssh2_pkt_addstring_start(ssh);
3939 for (i = 0; i < lenof(hostkey_algs); i++) {
3940 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3941 if (i < lenof(hostkey_algs) - 1)
3942 ssh2_pkt_addstring_str(ssh, ",");
3944 /* List client->server encryption algorithms. */
3945 ssh2_pkt_addstring_start(ssh);
3946 cipherstr_started = 0;
3947 for (i = 0; i < s->n_preferred_ciphers; i++) {
3948 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3949 if (!c) continue; /* warning flag */
3950 for (j = 0; j < c->nciphers; j++) {
3951 if (cipherstr_started)
3952 ssh2_pkt_addstring_str(ssh, ",");
3953 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3954 cipherstr_started = 1;
3957 /* List server->client encryption algorithms. */
3958 ssh2_pkt_addstring_start(ssh);
3959 cipherstr_started = 0;
3960 for (i = 0; i < s->n_preferred_ciphers; i++) {
3961 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3962 if (!c) continue; /* warning flag */
3963 for (j = 0; j < c->nciphers; j++) {
3964 if (cipherstr_started)
3965 ssh2_pkt_addstring_str(ssh, ",");
3966 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3967 cipherstr_started = 1;
3970 /* List client->server MAC algorithms. */
3971 ssh2_pkt_addstring_start(ssh);
3972 for (i = 0; i < s->nmacs; i++) {
3973 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3974 if (i < s->nmacs - 1)
3975 ssh2_pkt_addstring_str(ssh, ",");
3977 /* List server->client MAC algorithms. */
3978 ssh2_pkt_addstring_start(ssh);
3979 for (i = 0; i < s->nmacs; i++) {
3980 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3981 if (i < s->nmacs - 1)
3982 ssh2_pkt_addstring_str(ssh, ",");
3984 /* List client->server compression algorithms. */
3985 ssh2_pkt_addstring_start(ssh);
3986 for (i = 0; i < lenof(compressions) + 1; i++) {
3987 const struct ssh_compress *c =
3988 i == 0 ? s->preferred_comp : compressions[i - 1];
3989 ssh2_pkt_addstring_str(ssh, c->name);
3990 if (i < lenof(compressions))
3991 ssh2_pkt_addstring_str(ssh, ",");
3993 /* List server->client compression algorithms. */
3994 ssh2_pkt_addstring_start(ssh);
3995 for (i = 0; i < lenof(compressions) + 1; i++) {
3996 const struct ssh_compress *c =
3997 i == 0 ? s->preferred_comp : compressions[i - 1];
3998 ssh2_pkt_addstring_str(ssh, c->name);
3999 if (i < lenof(compressions))
4000 ssh2_pkt_addstring_str(ssh, ",");
4002 /* List client->server languages. Empty list. */
4003 ssh2_pkt_addstring_start(ssh);
4004 /* List server->client languages. Empty list. */
4005 ssh2_pkt_addstring_start(ssh);
4006 /* First KEX packet does _not_ follow, because we're not that brave. */
4007 ssh2_pkt_addbool(ssh, FALSE);
4009 ssh2_pkt_adduint32(ssh, 0);
4012 ssh->exhash = ssh->exhashbase;
4013 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4019 if (ssh->pktin.length > 5)
4020 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4023 * Now examine the other side's KEXINIT to see what we're up
4030 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4031 bombout(("expected key exchange packet from server"));
4035 ssh->hostkey = NULL;
4036 s->cscipher_tobe = NULL;
4037 s->sccipher_tobe = NULL;
4038 s->csmac_tobe = NULL;
4039 s->scmac_tobe = NULL;
4040 s->cscomp_tobe = NULL;
4041 s->sccomp_tobe = NULL;
4042 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4043 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4044 for (i = 0; i < lenof(kex_algs); i++) {
4045 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4046 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4048 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4049 ssh->kex = kex_algs[i];
4053 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4054 for (i = 0; i < lenof(hostkey_algs); i++) {
4055 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4056 ssh->hostkey = hostkey_algs[i];
4060 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4062 for (i = 0; i < s->n_preferred_ciphers; i++) {
4063 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4067 for (j = 0; j < c->nciphers; j++) {
4068 if (in_commasep_string(c->list[j]->name, str, len)) {
4069 s->cscipher_tobe = c->list[j];
4074 if (s->cscipher_tobe) {
4076 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4080 if (!s->cscipher_tobe) {
4081 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4082 str ? str : "(null)"));
4086 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4088 for (i = 0; i < s->n_preferred_ciphers; i++) {
4089 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4093 for (j = 0; j < c->nciphers; j++) {
4094 if (in_commasep_string(c->list[j]->name, str, len)) {
4095 s->sccipher_tobe = c->list[j];
4100 if (s->sccipher_tobe) {
4102 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4106 if (!s->sccipher_tobe) {
4107 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4108 str ? str : "(null)"));
4112 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4113 for (i = 0; i < s->nmacs; i++) {
4114 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4115 s->csmac_tobe = s->maclist[i];
4119 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4120 for (i = 0; i < s->nmacs; i++) {
4121 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4122 s->scmac_tobe = s->maclist[i];
4126 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4127 for (i = 0; i < lenof(compressions) + 1; i++) {
4128 const struct ssh_compress *c =
4129 i == 0 ? s->preferred_comp : compressions[i - 1];
4130 if (in_commasep_string(c->name, str, len)) {
4135 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4136 for (i = 0; i < lenof(compressions) + 1; i++) {
4137 const struct ssh_compress *c =
4138 i == 0 ? s->preferred_comp : compressions[i - 1];
4139 if (in_commasep_string(c->name, str, len)) {
4147 * Work out the number of bits of key we will need from the key
4148 * exchange. We start with the maximum key length of either
4154 csbits = s->cscipher_tobe->keylen;
4155 scbits = s->sccipher_tobe->keylen;
4156 s->nbits = (csbits > scbits ? csbits : scbits);
4158 /* The keys only have 160-bit entropy, since they're based on
4159 * a SHA-1 hash. So cap the key size at 160 bits. */
4164 * If we're doing Diffie-Hellman group exchange, start by
4165 * requesting a group.
4167 if (ssh->kex == &ssh_diffiehellman_gex) {
4168 logevent("Doing Diffie-Hellman group exchange");
4169 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4171 * Work out how big a DH group we will need to allow that
4174 s->pbits = 512 << ((s->nbits - 1) / 64);
4175 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4176 ssh2_pkt_adduint32(ssh, s->pbits);
4180 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4181 bombout(("expected key exchange group packet from server"));
4184 s->p = ssh2_pkt_getmp(ssh);
4185 s->g = ssh2_pkt_getmp(ssh);
4186 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4187 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4188 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4190 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4191 ssh->kex_ctx = dh_setup_group1();
4192 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4193 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4196 logevent("Doing Diffie-Hellman key exchange");
4198 * Now generate and send e for Diffie-Hellman.
4200 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4201 ssh2_pkt_init(ssh, s->kex_init_value);
4202 ssh2_pkt_addmp(ssh, s->e);
4206 if (ssh->pktin.type != s->kex_reply_value) {
4207 bombout(("expected key exchange reply packet from server"));
4210 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4211 s->f = ssh2_pkt_getmp(ssh);
4212 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4214 s->K = dh_find_K(ssh->kex_ctx, s->f);
4216 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4217 if (ssh->kex == &ssh_diffiehellman_gex) {
4218 sha_uint32(&ssh->exhash, s->pbits);
4219 sha_mpint(&ssh->exhash, s->p);
4220 sha_mpint(&ssh->exhash, s->g);
4222 sha_mpint(&ssh->exhash, s->e);
4223 sha_mpint(&ssh->exhash, s->f);
4224 sha_mpint(&ssh->exhash, s->K);
4225 SHA_Final(&ssh->exhash, s->exchange_hash);
4227 dh_cleanup(ssh->kex_ctx);
4228 ssh->kex_ctx = NULL;
4231 debug(("Exchange hash is:\n"));
4232 dmemdump(s->exchange_hash, 20);
4235 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4237 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4238 (char *)s->exchange_hash, 20)) {
4239 bombout(("Server's host key did not match the signature supplied"));
4244 * Authenticate remote host: verify host key. (We've already
4245 * checked the signature of the exchange hash.)
4247 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4248 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4249 verify_ssh_host_key(ssh->frontend,
4250 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4251 s->keystr, s->fingerprint);
4252 if (s->first_kex) { /* don't bother logging this in rekeys */
4253 logevent("Host key fingerprint is:");
4254 logevent(s->fingerprint);
4256 sfree(s->fingerprint);
4258 ssh->hostkey->freekey(s->hkey);
4261 * Send SSH2_MSG_NEWKEYS.
4263 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4267 * Expect SSH2_MSG_NEWKEYS from server.
4270 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4271 bombout(("expected new-keys packet from server"));
4276 * Create and initialise session keys.
4278 if (ssh->cs_cipher_ctx)
4279 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4280 ssh->cscipher = s->cscipher_tobe;
4281 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4283 if (ssh->sc_cipher_ctx)
4284 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4285 ssh->sccipher = s->sccipher_tobe;
4286 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4288 if (ssh->cs_mac_ctx)
4289 ssh->csmac->free_context(ssh->cs_mac_ctx);
4290 ssh->csmac = s->csmac_tobe;
4291 ssh->cs_mac_ctx = ssh->csmac->make_context();
4293 if (ssh->sc_mac_ctx)
4294 ssh->scmac->free_context(ssh->sc_mac_ctx);
4295 ssh->scmac = s->scmac_tobe;
4296 ssh->sc_mac_ctx = ssh->scmac->make_context();
4298 if (ssh->cs_comp_ctx)
4299 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4300 ssh->cscomp = s->cscomp_tobe;
4301 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4303 if (ssh->sc_comp_ctx)
4304 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4305 ssh->sccomp = s->sccomp_tobe;
4306 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4309 * Set IVs after keys. Here we use the exchange hash from the
4310 * _first_ key exchange.
4313 unsigned char keyspace[40];
4315 memcpy(ssh->v2_session_id, s->exchange_hash,
4316 sizeof(s->exchange_hash));
4317 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4318 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4319 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4320 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4321 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4322 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4323 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4324 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4325 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4326 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4327 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4328 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4330 logeventf(ssh, "Initialised %.200s client->server encryption",
4331 ssh->cscipher->text_name);
4332 logeventf(ssh, "Initialised %.200s server->client encryption",
4333 ssh->sccipher->text_name);
4334 if (ssh->cscomp->text_name)
4335 logeventf(ssh, "Initialised %s compression",
4336 ssh->cscomp->text_name);
4337 if (ssh->sccomp->text_name)
4338 logeventf(ssh, "Initialised %s decompression",
4339 ssh->sccomp->text_name);
4342 * If this is the first key exchange phase, we must pass the
4343 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4344 * wants to see it but because it will need time to initialise
4345 * itself before it sees an actual packet. In subsequent key
4346 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4347 * it would only confuse the layer above.
4349 if (!s->first_kex) {
4355 * Now we're encrypting. Begin returning 1 to the protocol main
4356 * function so that other things can run on top of the
4357 * transport. If we ever see a KEXINIT, we must go back to the
4360 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4363 logevent("Server initiated key re-exchange");
4364 goto begin_key_exchange;
4370 * Add data to an SSH2 channel output buffer.
4372 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4375 bufchain_add(&c->v.v2.outbuffer, buf, len);
4379 * Attempt to send data on an SSH2 channel.
4381 static int ssh2_try_send(struct ssh_channel *c)
4385 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4388 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4389 if ((unsigned)len > c->v.v2.remwindow)
4390 len = c->v.v2.remwindow;
4391 if ((unsigned)len > c->v.v2.remmaxpkt)
4392 len = c->v.v2.remmaxpkt;
4393 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4394 ssh2_pkt_adduint32(ssh, c->remoteid);
4395 ssh2_pkt_addstring_start(ssh);
4396 ssh2_pkt_addstring_data(ssh, data, len);
4398 bufchain_consume(&c->v.v2.outbuffer, len);
4399 c->v.v2.remwindow -= len;
4403 * After having sent as much data as we can, return the amount
4406 return bufchain_size(&c->v.v2.outbuffer);
4410 * Potentially enlarge the window on an SSH2 channel.
4412 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4417 * Never send WINDOW_ADJUST for a channel that the remote side
4418 * already thinks it's closed; there's no point, since it won't
4419 * be sending any more data anyway.
4424 if (newwin > c->v.v2.locwindow) {
4425 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4426 ssh2_pkt_adduint32(ssh, c->remoteid);
4427 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4429 c->v.v2.locwindow = newwin;
4434 * Handle the SSH2 userauth and connection layers.
4436 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4438 struct do_ssh2_authconn_state {
4440 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4442 AUTH_KEYBOARD_INTERACTIVE
4446 AUTH_TYPE_PUBLICKEY,
4447 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4448 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4450 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4451 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4453 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4454 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4455 int kbd_inter_running;
4457 int num_prompts, curr_prompt, echo;
4462 void *publickey_blob;
4463 int publickey_bloblen;
4464 unsigned char request[5], *response, *p;
4468 char *pkblob, *alg, *commentp;
4469 int pklen, alglen, commentlen;
4470 int siglen, retlen, len;
4471 char *q, *agentreq, *ret;
4474 crState(do_ssh2_authconn_state);
4476 crBegin(ssh->do_ssh2_authconn_crstate);
4479 * Request userauth protocol, and await a response to it.
4481 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4482 ssh2_pkt_addstring(ssh, "ssh-userauth");
4484 crWaitUntilV(ispkt);
4485 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4486 bombout(("Server refused user authentication protocol"));
4491 * We repeat this whole loop, including the username prompt,
4492 * until we manage a successful authentication. If the user
4493 * types the wrong _password_, they can be sent back to the
4494 * beginning to try another username, if this is configured on.
4495 * (If they specify a username in the config, they are never
4496 * asked, even if they do give a wrong password.)
4498 * I think this best serves the needs of
4500 * - the people who have no configuration, no keys, and just
4501 * want to try repeated (username,password) pairs until they
4502 * type both correctly
4504 * - people who have keys and configuration but occasionally
4505 * need to fall back to passwords
4507 * - people with a key held in Pageant, who might not have
4508 * logged in to a particular machine before; so they want to
4509 * type a username, and then _either_ their key will be
4510 * accepted, _or_ they will type a password. If they mistype
4511 * the username they will want to be able to get back and
4514 s->username[0] = '\0';
4515 s->got_username = FALSE;
4520 if (s->got_username && !ssh->cfg.change_username) {
4522 * We got a username last time round this loop, and
4523 * with change_username turned off we don't try to get
4526 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4527 if (ssh_get_line && !ssh_getline_pw_only) {
4528 if (!ssh_get_line("login as: ",
4529 s->username, sizeof(s->username), FALSE)) {
4531 * get_line failed to get a username.
4534 logevent("No username provided. Abandoning session.");
4535 ssh_closing((Plug)ssh, NULL, 0, 0);
4539 int ret; /* need not be saved across crReturn */
4540 c_write_str(ssh, "login as: ");
4542 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4544 crWaitUntilV(!ispkt);
4545 ret = process_userpass_input(ssh, in, inlen);
4549 c_write_str(ssh, "\r\n");
4551 s->username[strcspn(s->username, "\n\r")] = '\0';
4554 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4555 s->username[sizeof(s->username)-1] = '\0';
4556 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4557 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4558 c_write_str(ssh, stuff);
4562 s->got_username = TRUE;
4565 * Send an authentication request using method "none": (a)
4566 * just in case it succeeds, and (b) so that we know what
4567 * authentication methods we can usefully try next.
4569 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4571 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4572 ssh2_pkt_addstring(ssh, s->username);
4573 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4574 ssh2_pkt_addstring(ssh, "none"); /* method */
4576 s->type = AUTH_TYPE_NONE;
4578 s->we_are_in = FALSE;
4580 s->tried_pubkey_config = FALSE;
4581 s->tried_agent = FALSE;
4582 s->tried_keyb_inter = FALSE;
4583 s->kbd_inter_running = FALSE;
4584 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4585 if (!filename_is_null(ssh->cfg.keyfile)) {
4587 logeventf(ssh, "Reading private key file \"%.150s\"",
4588 filename_to_str(&ssh->cfg.keyfile));
4589 keytype = key_type(&ssh->cfg.keyfile);
4590 if (keytype == SSH_KEYTYPE_SSH2) {
4592 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4593 &s->publickey_bloblen, NULL);
4596 logeventf(ssh, "Unable to use this key file (%s)",
4597 key_type_to_str(keytype));
4598 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4600 filename_to_str(&ssh->cfg.keyfile),
4601 key_type_to_str(keytype));
4602 c_write_str(ssh, msgbuf);
4604 s->publickey_blob = NULL;
4607 s->publickey_blob = NULL;
4611 * Wait for the result of the last authentication request.
4614 crWaitUntilV(ispkt);
4615 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4619 * Don't show the banner if we're operating in
4620 * non-verbose non-interactive mode. (It's probably
4621 * a script, which means nobody will read the
4622 * banner _anyway_, and moreover the printing of
4623 * the banner will screw up processing on the
4624 * output of (say) plink.)
4626 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4627 ssh2_pkt_getstring(ssh, &banner, &size);
4629 c_write_untrusted(ssh, banner, size);
4631 crWaitUntilV(ispkt);
4633 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4634 logevent("Access granted");
4635 s->we_are_in = TRUE;
4639 if (s->kbd_inter_running &&
4640 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4642 * This is either a further set-of-prompts packet
4643 * in keyboard-interactive authentication, or it's
4644 * the same one and we came back here with `gotit'
4645 * set. In the former case, we must reset the
4646 * curr_prompt variable.
4650 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4651 bombout(("Strange packet received during authentication: type %d",
4659 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4660 * we can look at the string in it and know what we can
4661 * helpfully try next.
4663 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4666 ssh2_pkt_getstring(ssh, &methods, &methlen);
4667 s->kbd_inter_running = FALSE;
4668 if (!ssh2_pkt_getbool(ssh)) {
4670 * We have received an unequivocal Access
4671 * Denied. This can translate to a variety of
4674 * - if we'd just tried "none" authentication,
4675 * it's not worth printing anything at all
4677 * - if we'd just tried a public key _offer_,
4678 * the message should be "Server refused our
4679 * key" (or no message at all if the key
4680 * came from Pageant)
4682 * - if we'd just tried anything else, the
4683 * message really should be "Access denied".
4685 * Additionally, if we'd just tried password
4686 * authentication, we should break out of this
4687 * whole loop so as to go back to the username
4690 if (s->type == AUTH_TYPE_NONE) {
4692 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4693 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4694 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4695 c_write_str(ssh, "Server refused our key\r\n");
4696 logevent("Server refused public key");
4697 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4698 /* server declined keyboard-interactive; ignore */
4700 c_write_str(ssh, "Access denied\r\n");
4701 logevent("Access denied");
4702 if (s->type == AUTH_TYPE_PASSWORD) {
4703 s->we_are_in = FALSE;
4708 c_write_str(ssh, "Further authentication required\r\n");
4709 logevent("Further authentication required");
4713 in_commasep_string("publickey", methods, methlen);
4715 in_commasep_string("password", methods, methlen);
4716 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4717 in_commasep_string("keyboard-interactive", methods, methlen);
4721 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4724 * Most password/passphrase prompts will be
4725 * non-echoing, so we set this to 0 by default.
4726 * Exception is that some keyboard-interactive prompts
4727 * can be echoing, in which case we'll set this to 1.
4731 if (!s->method && s->can_pubkey &&
4732 agent_exists() && !s->tried_agent) {
4734 * Attempt public-key authentication using Pageant.
4739 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4740 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4742 s->tried_agent = TRUE;
4744 logevent("Pageant is running. Requesting keys.");
4746 /* Request the keys held by the agent. */
4747 PUT_32BIT(s->request, 1);
4748 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4749 if (!agent_query(s->request, 5, &r, &s->responselen,
4750 ssh_agent_callback, ssh)) {
4754 bombout(("Unexpected data from server while"
4755 " waiting for agent response"));
4758 } while (ispkt || inlen > 0);
4759 r = ssh->agent_response;
4760 s->responselen = ssh->agent_response_len;
4762 s->response = (unsigned char *) r;
4763 if (s->response && s->responselen >= 5 &&
4764 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4765 s->p = s->response + 5;
4766 s->nkeys = GET_32BIT(s->p);
4770 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4773 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4778 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4781 s->pklen = GET_32BIT(s->p);
4783 if (s->publickey_blob &&
4784 s->pklen == s->publickey_bloblen &&
4785 !memcmp(s->p, s->publickey_blob,
4786 s->publickey_bloblen)) {
4787 logevent("This key matches configured key file");
4788 s->tried_pubkey_config = 1;
4790 s->pkblob = (char *)s->p;
4792 s->alglen = GET_32BIT(s->pkblob);
4793 s->alg = s->pkblob + 4;
4794 s->commentlen = GET_32BIT(s->p);
4796 s->commentp = (char *)s->p;
4797 s->p += s->commentlen;
4798 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4799 ssh2_pkt_addstring(ssh, s->username);
4800 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4801 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4802 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4803 ssh2_pkt_addstring_start(ssh);
4804 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4805 ssh2_pkt_addstring_start(ssh);
4806 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4809 crWaitUntilV(ispkt);
4810 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4811 logevent("Key refused");
4815 if (flags & FLAG_VERBOSE) {
4816 c_write_str(ssh, "Authenticating with "
4818 c_write(ssh, s->commentp, s->commentlen);
4819 c_write_str(ssh, "\" from agent\r\n");
4823 * Server is willing to accept the key.
4824 * Construct a SIGN_REQUEST.
4826 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4827 ssh2_pkt_addstring(ssh, s->username);
4828 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4829 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4830 ssh2_pkt_addbool(ssh, TRUE);
4831 ssh2_pkt_addstring_start(ssh);
4832 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4833 ssh2_pkt_addstring_start(ssh);
4834 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4836 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4837 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4839 s->len = 1; /* message type */
4840 s->len += 4 + s->pklen; /* key blob */
4841 s->len += 4 + s->siglen; /* data to sign */
4842 s->len += 4; /* flags */
4843 s->agentreq = snewn(4 + s->len, char);
4844 PUT_32BIT(s->agentreq, s->len);
4845 s->q = s->agentreq + 4;
4846 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4847 PUT_32BIT(s->q, s->pklen);
4849 memcpy(s->q, s->pkblob, s->pklen);
4851 PUT_32BIT(s->q, s->siglen);
4853 /* Now the data to be signed... */
4854 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4855 PUT_32BIT(s->q, 20);
4858 memcpy(s->q, ssh->v2_session_id, 20);
4860 memcpy(s->q, ssh->pktout.data + 5,
4861 ssh->pktout.length - 5);
4862 s->q += ssh->pktout.length - 5;
4863 /* And finally the (zero) flags word. */
4865 if (!agent_query(s->agentreq, s->len + 4,
4867 ssh_agent_callback, ssh)) {
4871 bombout(("Unexpected data from server"
4872 " while waiting for agent"
4876 } while (ispkt || inlen > 0);
4877 vret = ssh->agent_response;
4878 s->retlen = ssh->agent_response_len;
4883 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4884 logevent("Sending Pageant's response");
4885 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4887 GET_32BIT(s->ret + 5));
4893 ("Pageant failed to answer challenge");
4903 if (!s->method && s->can_pubkey && s->publickey_blob
4904 && !s->tried_pubkey_config) {
4905 unsigned char *pub_blob;
4906 char *algorithm, *comment;
4909 s->tried_pubkey_config = TRUE;
4911 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4912 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4915 * Try the public key supplied in the configuration.
4917 * First, offer the public blob to see if the server is
4918 * willing to accept it.
4921 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4926 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4927 ssh2_pkt_addstring(ssh, s->username);
4928 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4929 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4930 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4931 ssh2_pkt_addstring(ssh, algorithm);
4932 ssh2_pkt_addstring_start(ssh);
4933 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4936 logevent("Offered public key"); /* FIXME */
4938 crWaitUntilV(ispkt);
4939 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4941 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4942 continue; /* key refused; give up on it */
4945 logevent("Offer of public key accepted");
4947 * Actually attempt a serious authentication using
4950 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4951 sprintf(s->pwprompt,
4952 "Passphrase for key \"%.100s\": ",
4958 c_write_str(ssh, "Authenticating with public key \"");
4959 c_write_str(ssh, comment);
4960 c_write_str(ssh, "\"\r\n");
4961 s->method = AUTH_PUBLICKEY_FILE;
4965 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4966 s->method = AUTH_KEYBOARD_INTERACTIVE;
4967 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4968 s->tried_keyb_inter = TRUE;
4970 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4971 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4973 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4974 ssh2_pkt_addstring(ssh, s->username);
4975 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4976 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4977 ssh2_pkt_addstring(ssh, ""); /* lang */
4978 ssh2_pkt_addstring(ssh, "");
4981 crWaitUntilV(ispkt);
4982 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4983 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4985 logevent("Keyboard-interactive authentication refused");
4986 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4990 s->kbd_inter_running = TRUE;
4994 if (s->kbd_inter_running) {
4995 s->method = AUTH_KEYBOARD_INTERACTIVE;
4996 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4997 s->tried_keyb_inter = TRUE;
4999 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5000 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5002 if (s->curr_prompt == 0) {
5004 * We've got a fresh USERAUTH_INFO_REQUEST.
5005 * Display header data, and start going through
5008 char *name, *inst, *lang;
5009 int name_len, inst_len, lang_len;
5011 ssh2_pkt_getstring(ssh, &name, &name_len);
5012 ssh2_pkt_getstring(ssh, &inst, &inst_len);
5013 ssh2_pkt_getstring(ssh, &lang, &lang_len);
5015 c_write_untrusted(ssh, name, name_len);
5016 c_write_str(ssh, "\r\n");
5019 c_write_untrusted(ssh, inst, inst_len);
5020 c_write_str(ssh, "\r\n");
5022 s->num_prompts = ssh2_pkt_getuint32(ssh);
5026 * If there are prompts remaining in the packet,
5027 * display one and get a response.
5029 if (s->curr_prompt < s->num_prompts) {
5033 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
5034 if (prompt_len > 0) {
5035 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
5036 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
5037 prompt_len : sizeof(s->pwprompt)-1] = '\0';
5040 "<server failed to send prompt>: ");
5042 s->echo = ssh2_pkt_getbool(ssh);
5048 if (!s->method && s->can_passwd) {
5049 s->method = AUTH_PASSWORD;
5050 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5051 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5052 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5059 if (!ssh_get_line(s->pwprompt, s->password,
5060 sizeof(s->password), TRUE)) {
5062 * get_line failed to get a password (for
5063 * example because one was supplied on the
5064 * command line which has already failed to
5067 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5068 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5069 ssh2_pkt_addstring(ssh, "No more passwords available"
5071 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5073 logevent("Unable to authenticate");
5074 connection_fatal(ssh->frontend,
5075 "Unable to authenticate");
5076 ssh_closing((Plug)ssh, NULL, 0, 0);
5080 int ret; /* need not be saved across crReturn */
5081 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5084 setup_userpass_input(ssh, s->password,
5085 sizeof(s->password), s->echo);
5087 crWaitUntilV(!ispkt);
5088 ret = process_userpass_input(ssh, in, inlen);
5092 c_write_str(ssh, "\r\n");
5096 if (s->method == AUTH_PUBLICKEY_FILE) {
5098 * We have our passphrase. Now try the actual authentication.
5100 struct ssh2_userkey *key;
5101 const char *error = NULL;
5103 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5105 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5106 if (key == SSH2_WRONG_PASSPHRASE) {
5107 c_write_str(ssh, "Wrong passphrase\r\n");
5108 s->tried_pubkey_config = FALSE;
5110 c_write_str(ssh, "Unable to load private key (");
5111 c_write_str(ssh, error);
5112 c_write_str(ssh, ")\r\n");
5113 s->tried_pubkey_config = TRUE;
5115 /* Send a spurious AUTH_NONE to return to the top. */
5116 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5117 ssh2_pkt_addstring(ssh, s->username);
5118 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5119 ssh2_pkt_addstring(ssh, "none"); /* method */
5121 s->type = AUTH_TYPE_NONE;
5123 unsigned char *pkblob, *sigblob, *sigdata;
5124 int pkblob_len, sigblob_len, sigdata_len;
5128 * We have loaded the private key and the server
5129 * has announced that it's willing to accept it.
5130 * Hallelujah. Generate a signature and send it.
5132 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5133 ssh2_pkt_addstring(ssh, s->username);
5134 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5135 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5136 ssh2_pkt_addbool(ssh, TRUE);
5137 ssh2_pkt_addstring(ssh, key->alg->name);
5138 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5139 ssh2_pkt_addstring_start(ssh);
5140 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5143 * The data to be signed is:
5147 * followed by everything so far placed in the
5150 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5151 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5153 sigdata = snewn(sigdata_len, unsigned char);
5155 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5156 PUT_32BIT(sigdata+p, 20);
5159 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5160 memcpy(sigdata+p, ssh->pktout.data + 5,
5161 ssh->pktout.length - 5);
5162 p += ssh->pktout.length - 5;
5163 assert(p == sigdata_len);
5164 sigblob = key->alg->sign(key->data, (char *)sigdata,
5165 sigdata_len, &sigblob_len);
5166 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5167 sigblob, sigblob_len);
5173 s->type = AUTH_TYPE_PUBLICKEY;
5175 } else if (s->method == AUTH_PASSWORD) {
5177 * We send the password packet lumped tightly together with
5178 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5179 * string long enough to make the total length of the two
5180 * packets constant. This should ensure that a passive
5181 * listener doing traffic analyis can't work out the length
5184 * For this to work, we need an assumption about the
5185 * maximum length of the password packet. I think 256 is
5186 * pretty conservative. Anyone using a password longer than
5187 * that probably doesn't have much to worry about from
5188 * people who find out how long their password is!
5190 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5191 ssh2_pkt_addstring(ssh, s->username);
5192 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5193 ssh2_pkt_addstring(ssh, "password");
5194 ssh2_pkt_addbool(ssh, FALSE);
5195 ssh2_pkt_addstring(ssh, s->password);
5196 memset(s->password, 0, sizeof(s->password));
5197 ssh2_pkt_defer(ssh);
5199 * We'll include a string that's an exact multiple of the
5200 * cipher block size. If the cipher is NULL for some
5201 * reason, we don't do this trick at all because we gain
5204 if (ssh->cscipher) {
5207 stringlen = (256 - ssh->deferred_len);
5208 stringlen += ssh->cscipher->blksize - 1;
5209 stringlen -= (stringlen % ssh->cscipher->blksize);
5212 * Temporarily disable actual compression,
5213 * so we can guarantee to get this string
5214 * exactly the length we want it. The
5215 * compression-disabling routine should
5216 * return an integer indicating how many
5217 * bytes we should adjust our string length
5221 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5223 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5224 ssh2_pkt_addstring_start(ssh);
5225 for (i = 0; i < stringlen; i++) {
5226 char c = (char) random_byte();
5227 ssh2_pkt_addstring_data(ssh, &c, 1);
5229 ssh2_pkt_defer(ssh);
5231 ssh_pkt_defersend(ssh);
5232 logevent("Sent password");
5233 s->type = AUTH_TYPE_PASSWORD;
5234 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5235 if (s->curr_prompt == 0) {
5236 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5237 ssh2_pkt_adduint32(ssh, s->num_prompts);
5239 if (s->need_pw) { /* only add pw if we just got one! */
5240 ssh2_pkt_addstring(ssh, s->password);
5241 memset(s->password, 0, sizeof(s->password));
5244 if (s->curr_prompt >= s->num_prompts) {
5248 * If there are prompts remaining, we set
5249 * `gotit' so that we won't attempt to get
5250 * another packet. Then we go back round the
5251 * loop and will end up retrieving another
5252 * prompt out of the existing packet. Funky or
5257 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5259 c_write_str(ssh, "No supported authentication methods"
5260 " left to try!\r\n");
5261 logevent("No supported authentications offered."
5263 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5264 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5265 ssh2_pkt_addstring(ssh, "No supported authentication"
5266 " methods available");
5267 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5269 ssh_closing((Plug)ssh, NULL, 0, 0);
5273 } while (!s->we_are_in);
5276 * Now we're authenticated for the connection protocol. The
5277 * connection protocol will automatically have started at this
5278 * point; there's no need to send SERVICE_REQUEST.
5282 * So now create a channel with a session in it.
5284 ssh->channels = newtree234(ssh_channelcmp);
5285 ssh->mainchan = snew(struct ssh_channel);
5286 ssh->mainchan->ssh = ssh;
5287 ssh->mainchan->localid = alloc_channel_id(ssh);
5288 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5289 ssh2_pkt_addstring(ssh, "session");
5290 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5291 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5292 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5293 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5295 crWaitUntilV(ispkt);
5296 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5297 bombout(("Server refused to open a session"));
5299 /* FIXME: error data comes back in FAILURE packet */
5301 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5302 bombout(("Server's channel confirmation cited wrong channel"));
5305 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5306 ssh->mainchan->type = CHAN_MAINSESSION;
5307 ssh->mainchan->closes = 0;
5308 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5309 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5310 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5311 add234(ssh->channels, ssh->mainchan);
5312 logevent("Opened channel for session");
5315 * Potentially enable X11 forwarding.
5317 if (ssh->cfg.x11_forward) {
5318 char proto[20], data[64];
5319 logevent("Requesting X11 forwarding");
5320 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5321 data, sizeof(data), ssh->cfg.x11_auth);
5322 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5323 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5324 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5325 ssh2_pkt_addstring(ssh, "x11-req");
5326 ssh2_pkt_addbool(ssh, 1); /* want reply */
5327 ssh2_pkt_addbool(ssh, 0); /* many connections */
5328 ssh2_pkt_addstring(ssh, proto);
5329 ssh2_pkt_addstring(ssh, data);
5330 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5334 crWaitUntilV(ispkt);
5335 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5336 unsigned i = ssh2_pkt_getuint32(ssh);
5337 struct ssh_channel *c;
5338 c = find234(ssh->channels, &i, ssh_channelfind);
5340 continue; /* nonexistent channel */
5341 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5343 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5345 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5346 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5347 bombout(("Unexpected response to X11 forwarding request:"
5348 " packet type %d", ssh->pktin.type));
5351 logevent("X11 forwarding refused");
5353 logevent("X11 forwarding enabled");
5354 ssh->X11_fwd_enabled = TRUE;
5359 * Enable port forwardings.
5364 int sport,dport,sserv,dserv;
5365 char sports[256], dports[256], saddr[256], host[256];
5367 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5368 /* Add port forwardings. */
5369 ssh->portfwd_strptr = ssh->cfg.portfwd;
5370 while (*ssh->portfwd_strptr) {
5371 type = *ssh->portfwd_strptr++;
5374 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5375 if (*ssh->portfwd_strptr == ':') {
5377 * We've seen a colon in the middle of the
5378 * source port number. This means that
5379 * everything we've seen until now is the
5380 * source _address_, so we'll move it into
5381 * saddr and start sports from the beginning
5384 ssh->portfwd_strptr++;
5386 strcpy(saddr, sports);
5389 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5393 if (*ssh->portfwd_strptr == '\t')
5394 ssh->portfwd_strptr++;
5396 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5397 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5400 if (*ssh->portfwd_strptr == ':')
5401 ssh->portfwd_strptr++;
5403 while (*ssh->portfwd_strptr) {
5404 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5407 ssh->portfwd_strptr++;
5408 dport = atoi(dports);
5412 dport = net_service_lookup(dports);
5414 logeventf(ssh, "Service lookup failed for destination"
5415 " port \"%s\"", dports);
5419 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5422 sport = atoi(sports);
5426 sport = net_service_lookup(sports);
5428 logeventf(ssh, "Service lookup failed for source"
5429 " port \"%s\"", sports);
5432 if (sport && dport) {
5434 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5435 sport, ssh, &ssh->cfg);
5436 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5437 " forwarding to %s:%.*s%.*s%d%.*s",
5438 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5439 (int)(*saddr?1:0), ":",
5440 (int)(sserv ? strlen(sports) : 0), sports,
5441 sserv, "(", sport, sserv, ")",
5443 (int)(dserv ? strlen(dports) : 0), dports,
5444 dserv, "(", dport, dserv, ")");
5445 } else if (type == 'D') {
5446 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5447 sport, ssh, &ssh->cfg);
5448 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5449 " doing SOCKS dynamic forwarding",
5450 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5451 (int)(*saddr?1:0), ":",
5452 (int)(sserv ? strlen(sports) : 0), sports,
5453 sserv, "(", sport, sserv, ")");
5455 struct ssh_rportfwd *pf;
5456 pf = snew(struct ssh_rportfwd);
5457 strcpy(pf->dhost, host);
5460 if (add234(ssh->rportfwds, pf) != pf) {
5461 logeventf(ssh, "Duplicate remote port forwarding"
5462 " to %s:%d", host, dport);
5465 logeventf(ssh, "Requesting remote port "
5466 "%.*s%.*s%.*s%.*s%d%.*s"
5467 " forward to %s:%.*s%.*s%d%.*s",
5468 (int)(*saddr?strlen(saddr):0),
5470 (int)(*saddr?1:0), ":",
5471 (int)(sserv ? strlen(sports) : 0), sports,
5472 sserv, "(", sport, sserv, ")",
5474 (int)(dserv ? strlen(dports) : 0), dports,
5475 dserv, "(", dport, dserv, ")");
5476 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5477 ssh2_pkt_addstring(ssh, "tcpip-forward");
5478 ssh2_pkt_addbool(ssh, 1);/* want reply */
5480 ssh2_pkt_addstring(ssh, saddr);
5481 if (ssh->cfg.rport_acceptall)
5482 ssh2_pkt_addstring(ssh, "0.0.0.0");
5484 ssh2_pkt_addstring(ssh, "127.0.0.1");
5485 ssh2_pkt_adduint32(ssh, sport);
5489 crWaitUntilV(ispkt);
5490 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5491 unsigned i = ssh2_pkt_getuint32(ssh);
5492 struct ssh_channel *c;
5493 c = find234(ssh->channels, &i, ssh_channelfind);
5495 continue;/* nonexistent channel */
5496 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5498 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5500 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5501 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5502 bombout(("Unexpected response to port "
5503 "forwarding request: packet type %d",
5507 logevent("Server refused this port forwarding");
5509 logevent("Remote port forwarding enabled");
5518 * Potentially enable agent forwarding.
5520 if (ssh->cfg.agentfwd && agent_exists()) {
5521 logevent("Requesting OpenSSH-style agent forwarding");
5522 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5523 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5524 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5525 ssh2_pkt_addbool(ssh, 1); /* want reply */
5529 crWaitUntilV(ispkt);
5530 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5531 unsigned i = ssh2_pkt_getuint32(ssh);
5532 struct ssh_channel *c;
5533 c = find234(ssh->channels, &i, ssh_channelfind);
5535 continue; /* nonexistent channel */
5536 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5538 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5540 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5541 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5542 bombout(("Unexpected response to agent forwarding request:"
5543 " packet type %d", ssh->pktin.type));
5546 logevent("Agent forwarding refused");
5548 logevent("Agent forwarding enabled");
5549 ssh->agentfwd_enabled = TRUE;
5554 * Now allocate a pty for the session.
5556 if (!ssh->cfg.nopty) {
5557 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5558 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5559 ssh2_pkt_addstring(ssh, "pty-req");
5560 ssh2_pkt_addbool(ssh, 1); /* want reply */
5561 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5562 ssh2_pkt_adduint32(ssh, ssh->term_width);
5563 ssh2_pkt_adduint32(ssh, ssh->term_height);
5564 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5565 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5566 ssh2_pkt_addstring_start(ssh);
5567 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5569 ssh->state = SSH_STATE_INTERMED;
5572 crWaitUntilV(ispkt);
5573 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5574 unsigned i = ssh2_pkt_getuint32(ssh);
5575 struct ssh_channel *c;
5576 c = find234(ssh->channels, &i, ssh_channelfind);
5578 continue; /* nonexistent channel */
5579 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5581 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5583 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5584 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5585 bombout(("Unexpected response to pty request:"
5586 " packet type %d", ssh->pktin.type));
5589 c_write_str(ssh, "Server refused to allocate pty\r\n");
5590 ssh->editing = ssh->echoing = 1;
5592 logevent("Allocated pty");
5595 ssh->editing = ssh->echoing = 1;
5599 * Start a shell or a remote command. We may have to attempt
5600 * this twice if the config data has provided a second choice
5607 if (ssh->fallback_cmd) {
5608 subsys = ssh->cfg.ssh_subsys2;
5609 cmd = ssh->cfg.remote_cmd_ptr2;
5611 subsys = ssh->cfg.ssh_subsys;
5612 cmd = ssh->cfg.remote_cmd_ptr;
5615 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5616 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5618 ssh2_pkt_addstring(ssh, "subsystem");
5619 ssh2_pkt_addbool(ssh, 1); /* want reply */
5620 ssh2_pkt_addstring(ssh, cmd);
5622 ssh2_pkt_addstring(ssh, "exec");
5623 ssh2_pkt_addbool(ssh, 1); /* want reply */
5624 ssh2_pkt_addstring(ssh, cmd);
5626 ssh2_pkt_addstring(ssh, "shell");
5627 ssh2_pkt_addbool(ssh, 1); /* want reply */
5631 crWaitUntilV(ispkt);
5632 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5633 unsigned i = ssh2_pkt_getuint32(ssh);
5634 struct ssh_channel *c;
5635 c = find234(ssh->channels, &i, ssh_channelfind);
5637 continue; /* nonexistent channel */
5638 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5640 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5641 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5642 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5643 bombout(("Unexpected response to shell/command request:"
5644 " packet type %d", ssh->pktin.type));
5648 * We failed to start the command. If this is the
5649 * fallback command, we really are finished; if it's
5650 * not, and if the fallback command exists, try falling
5651 * back to it before complaining.
5653 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5654 logevent("Primary command failed; attempting fallback");
5655 ssh->fallback_cmd = TRUE;
5658 bombout(("Server refused to start a shell/command"));
5661 logevent("Started a shell/command");
5666 ssh->state = SSH_STATE_SESSION;
5667 if (ssh->size_needed)
5668 ssh_size(ssh, ssh->term_width, ssh->term_height);
5669 if (ssh->eof_needed)
5670 ssh_special(ssh, TS_EOF);
5676 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5680 s->try_send = FALSE;
5682 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5683 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5686 unsigned i = ssh2_pkt_getuint32(ssh);
5687 struct ssh_channel *c;
5688 c = find234(ssh->channels, &i, ssh_channelfind);
5690 continue; /* nonexistent channel */
5691 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5692 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5693 continue; /* extended but not stderr */
5694 ssh2_pkt_getstring(ssh, &data, &length);
5697 c->v.v2.locwindow -= length;
5699 case CHAN_MAINSESSION:
5701 from_backend(ssh->frontend, ssh->pktin.type ==
5702 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5706 bufsize = x11_send(c->u.x11.s, data, length);
5709 bufsize = pfd_send(c->u.pfd.s, data, length);
5712 while (length > 0) {
5713 if (c->u.a.lensofar < 4) {
5714 int l = min(4 - c->u.a.lensofar, length);
5715 memcpy(c->u.a.msglen + c->u.a.lensofar,
5719 c->u.a.lensofar += l;
5721 if (c->u.a.lensofar == 4) {
5723 4 + GET_32BIT(c->u.a.msglen);
5724 c->u.a.message = snewn(c->u.a.totallen,
5726 memcpy(c->u.a.message, c->u.a.msglen, 4);
5728 if (c->u.a.lensofar >= 4 && length > 0) {
5730 min(c->u.a.totallen - c->u.a.lensofar,
5732 memcpy(c->u.a.message + c->u.a.lensofar,
5736 c->u.a.lensofar += l;
5738 if (c->u.a.lensofar == c->u.a.totallen) {
5741 if (agent_query(c->u.a.message,
5744 ssh_agentf_callback, c))
5745 ssh_agentf_callback(c, reply, replylen);
5746 sfree(c->u.a.message);
5747 c->u.a.lensofar = 0;
5754 * If we are not buffering too much data,
5755 * enlarge the window again at the remote side.
5757 if (bufsize < OUR_V2_WINSIZE)
5758 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5760 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5761 unsigned i = ssh2_pkt_getuint32(ssh);
5762 struct ssh_channel *c;
5764 c = find234(ssh->channels, &i, ssh_channelfind);
5766 continue; /* nonexistent channel */
5768 if (c->type == CHAN_X11) {
5770 * Remote EOF on an X11 channel means we should
5771 * wrap up and close the channel ourselves.
5773 x11_close(c->u.x11.s);
5775 } else if (c->type == CHAN_AGENT) {
5777 } else if (c->type == CHAN_SOCKDATA) {
5778 pfd_close(c->u.pfd.s);
5781 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5782 unsigned i = ssh2_pkt_getuint32(ssh);
5783 struct ssh_channel *c;
5785 c = find234(ssh->channels, &i, ssh_channelfind);
5786 if (!c || ((int)c->remoteid) == -1) {
5787 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5788 c ? "half-open" : "nonexistent", i));
5791 /* Do pre-close processing on the channel. */
5793 case CHAN_MAINSESSION:
5794 break; /* nothing to see here, move along */
5796 if (c->u.x11.s != NULL)
5797 x11_close(c->u.x11.s);
5804 if (c->u.pfd.s != NULL)
5805 pfd_close(c->u.pfd.s);
5809 if (c->closes == 0) {
5810 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5811 ssh2_pkt_adduint32(ssh, c->remoteid);
5814 del234(ssh->channels, c);
5815 bufchain_clear(&c->v.v2.outbuffer);
5819 * See if that was the last channel left open.
5821 if (count234(ssh->channels) == 0) {
5822 logevent("All channels closed. Disconnecting");
5825 * We used to send SSH_MSG_DISCONNECT here,
5826 * because I'd believed that _every_ conforming
5827 * SSH2 connection had to end with a disconnect
5828 * being sent by at least one side; apparently
5829 * I was wrong and it's perfectly OK to
5830 * unceremoniously slam the connection shut
5831 * when you're done, and indeed OpenSSH feels
5832 * this is more polite than sending a
5833 * DISCONNECT. So now we don't.
5835 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5836 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5837 ssh2_pkt_addstring(ssh, "All open channels closed");
5838 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5841 ssh_closing((Plug)ssh, NULL, 0, 0);
5844 continue; /* remote sends close; ignore (FIXME) */
5845 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5846 unsigned i = ssh2_pkt_getuint32(ssh);
5847 struct ssh_channel *c;
5848 c = find234(ssh->channels, &i, ssh_channelfind);
5849 if (!c || c->closes)
5850 continue; /* nonexistent or closing channel */
5851 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5853 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5854 unsigned i = ssh2_pkt_getuint32(ssh);
5855 struct ssh_channel *c;
5856 c = find234(ssh->channels, &i, ssh_channelfind);
5858 continue; /* nonexistent channel */
5859 if (c->type != CHAN_SOCKDATA_DORMANT)
5860 continue; /* dunno why they're confirming this */
5861 c->remoteid = ssh2_pkt_getuint32(ssh);
5862 c->type = CHAN_SOCKDATA;
5863 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5864 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5866 pfd_confirm(c->u.pfd.s);
5869 * We have a pending close on this channel,
5870 * which we decided on before the server acked
5871 * the channel open. So now we know the
5872 * remoteid, we can close it again.
5874 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5875 ssh2_pkt_adduint32(ssh, c->remoteid);
5878 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5879 unsigned i = ssh2_pkt_getuint32(ssh);
5880 struct ssh_channel *c;
5881 c = find234(ssh->channels, &i, ssh_channelfind);
5883 continue; /* nonexistent channel */
5884 if (c->type != CHAN_SOCKDATA_DORMANT)
5885 continue; /* dunno why they're failing this */
5887 logevent("Forwarded connection refused by server");
5889 pfd_close(c->u.pfd.s);
5891 del234(ssh->channels, c);
5893 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5896 int typelen, want_reply;
5897 struct ssh_channel *c;
5899 localid = ssh2_pkt_getuint32(ssh);
5900 ssh2_pkt_getstring(ssh, &type, &typelen);
5901 want_reply = ssh2_pkt_getbool(ssh);
5904 * First, check that the channel exists. Otherwise,
5905 * we can instantly disconnect with a rude message.
5907 c = find234(ssh->channels, &localid, ssh_channelfind);
5910 sprintf(buf, "Received channel request for nonexistent"
5911 " channel %d", localid);
5913 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5914 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5915 ssh2_pkt_addstring(ssh, buf);
5916 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5918 connection_fatal(ssh->frontend, "%s", buf);
5919 ssh_closing((Plug)ssh, NULL, 0, 0);
5924 * Having got the channel number, we now look at
5925 * the request type string to see if it's something
5928 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5929 c == ssh->mainchan) {
5930 /* We recognise "exit-status" on the primary channel. */
5932 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5933 sprintf(buf, "Server sent command exit status %d",
5937 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5938 ssh2_pkt_adduint32(ssh, c->remoteid);
5943 * This is a channel request we don't know
5944 * about, so we now either ignore the request
5945 * or respond with CHANNEL_FAILURE, depending
5949 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5950 ssh2_pkt_adduint32(ssh, c->remoteid);
5954 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5956 int typelen, want_reply;
5958 ssh2_pkt_getstring(ssh, &type, &typelen);
5959 want_reply = ssh2_pkt_getbool(ssh);
5962 * We currently don't support any global requests
5963 * at all, so we either ignore the request or
5964 * respond with REQUEST_FAILURE, depending on
5968 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5971 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5978 struct ssh_channel *c;
5979 unsigned remid, winsize, pktsize;
5980 ssh2_pkt_getstring(ssh, &type, &typelen);
5981 c = snew(struct ssh_channel);
5984 remid = ssh2_pkt_getuint32(ssh);
5985 winsize = ssh2_pkt_getuint32(ssh);
5986 pktsize = ssh2_pkt_getuint32(ssh);
5988 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5991 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5992 addrstr = snewn(peeraddrlen+1, char);
5993 memcpy(addrstr, peeraddr, peeraddrlen);
5994 peeraddr[peeraddrlen] = '\0';
5995 peerport = ssh2_pkt_getuint32(ssh);
5997 if (!ssh->X11_fwd_enabled)
5998 error = "X11 forwarding is not enabled";
5999 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6000 ssh->x11auth, addrstr, peerport,
6001 &ssh->cfg) != NULL) {
6002 error = "Unable to open an X11 connection";
6008 } else if (typelen == 15 &&
6009 !memcmp(type, "forwarded-tcpip", 15)) {
6010 struct ssh_rportfwd pf, *realpf;
6013 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6014 pf.sport = ssh2_pkt_getuint32(ssh);
6015 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6016 peerport = ssh2_pkt_getuint32(ssh);
6017 realpf = find234(ssh->rportfwds, &pf, NULL);
6018 if (realpf == NULL) {
6019 error = "Remote port is not recognised";
6021 const char *e = pfd_newconnect(&c->u.pfd.s,
6025 logeventf(ssh, "Received remote port open request"
6026 " for %s:%d", realpf->dhost, realpf->dport);
6028 logeventf(ssh, "Port open failed: %s", e);
6029 error = "Port open failed";
6031 logevent("Forwarded port opened successfully");
6032 c->type = CHAN_SOCKDATA;
6035 } else if (typelen == 22 &&
6036 !memcmp(type, "auth-agent@openssh.com", 3)) {
6037 if (!ssh->agentfwd_enabled)
6038 error = "Agent forwarding is not enabled";
6040 c->type = CHAN_AGENT; /* identify channel type */
6041 c->u.a.lensofar = 0;
6044 error = "Unsupported channel type requested";
6047 c->remoteid = remid;
6049 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6050 ssh2_pkt_adduint32(ssh, c->remoteid);
6051 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6052 ssh2_pkt_addstring(ssh, error);
6053 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6057 c->localid = alloc_channel_id(ssh);
6059 c->v.v2.locwindow = OUR_V2_WINSIZE;
6060 c->v.v2.remwindow = winsize;
6061 c->v.v2.remmaxpkt = pktsize;
6062 bufchain_init(&c->v.v2.outbuffer);
6063 add234(ssh->channels, c);
6064 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6065 ssh2_pkt_adduint32(ssh, c->remoteid);
6066 ssh2_pkt_adduint32(ssh, c->localid);
6067 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6068 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6072 bombout(("Strange packet received: type %d", ssh->pktin.type));
6077 * We have spare data. Add it to the channel buffer.
6079 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6084 struct ssh_channel *c;
6086 * Try to send data on all channels if we can.
6088 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6091 continue; /* don't send on closing channels */
6092 bufsize = ssh2_try_send(c);
6095 case CHAN_MAINSESSION:
6096 /* stdin need not receive an unthrottle
6097 * notification since it will be polled */
6100 x11_unthrottle(c->u.x11.s);
6103 /* agent sockets are request/response and need no
6104 * buffer management */
6107 pfd_unthrottle(c->u.pfd.s);
6119 * Handle the top-level SSH2 protocol.
6121 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6123 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6125 do_ssh2_authconn(ssh, in, inlen, ispkt);
6129 * Called to set up the connection.
6131 * Returns an error message, or NULL on success.
6133 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6135 char *host, int port, char **realhost, int nodelay)
6140 ssh = snew(struct ssh_tag);
6141 ssh->cfg = *cfg; /* STRUCTURE COPY */
6142 ssh->version = 0; /* when not ready yet */
6145 ssh->v1_cipher_ctx = NULL;
6146 ssh->crcda_ctx = NULL;
6147 ssh->cscipher = NULL;
6148 ssh->cs_cipher_ctx = NULL;
6149 ssh->sccipher = NULL;
6150 ssh->sc_cipher_ctx = NULL;
6152 ssh->cs_mac_ctx = NULL;
6154 ssh->sc_mac_ctx = NULL;
6156 ssh->cs_comp_ctx = NULL;
6158 ssh->sc_comp_ctx = NULL;
6160 ssh->kex_ctx = NULL;
6161 ssh->hostkey = NULL;
6163 ssh->state = SSH_STATE_PREPACKET;
6164 ssh->size_needed = FALSE;
6165 ssh->eof_needed = FALSE;
6169 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6170 ssh->pktin = ssh->pktout = empty;
6172 ssh->deferred_send_data = NULL;
6173 ssh->deferred_len = 0;
6174 ssh->deferred_size = 0;
6175 ssh->fallback_cmd = 0;
6177 ssh->x11auth = NULL;
6178 ssh->v1_compressing = FALSE;
6179 ssh->v2_outgoing_sequence = 0;
6180 ssh->ssh1_rdpkt_crstate = 0;
6181 ssh->ssh2_rdpkt_crstate = 0;
6182 ssh->do_ssh_init_crstate = 0;
6183 ssh->ssh_gotdata_crstate = 0;
6184 ssh->ssh1_protocol_crstate = 0;
6185 ssh->do_ssh1_login_crstate = 0;
6186 ssh->do_ssh2_transport_crstate = 0;
6187 ssh->do_ssh2_authconn_crstate = 0;
6188 ssh->do_ssh_init_state = NULL;
6189 ssh->do_ssh1_login_state = NULL;
6190 ssh->do_ssh2_transport_state = NULL;
6191 ssh->do_ssh2_authconn_state = NULL;
6192 ssh->mainchan = NULL;
6193 ssh->throttled_all = 0;
6194 ssh->v1_stdout_throttling = 0;
6196 *backend_handle = ssh;
6199 if (crypto_startup() == 0)
6200 return "Microsoft high encryption pack not installed!";
6203 ssh->frontend = frontend_handle;
6204 ssh->term_width = ssh->cfg.width;
6205 ssh->term_height = ssh->cfg.height;
6207 ssh->channels = NULL;
6208 ssh->rportfwds = NULL;
6213 ssh->v1_throttle_count = 0;
6214 ssh->overall_bufsize = 0;
6215 ssh->fallback_cmd = 0;
6217 ssh->protocol = NULL;
6219 p = connect_to_host(ssh, host, port, realhost, nodelay);
6226 static void ssh_free(void *handle)
6228 Ssh ssh = (Ssh) handle;
6229 struct ssh_channel *c;
6230 struct ssh_rportfwd *pf;
6232 if (ssh->v1_cipher_ctx)
6233 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6234 if (ssh->cs_cipher_ctx)
6235 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6236 if (ssh->sc_cipher_ctx)
6237 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6238 if (ssh->cs_mac_ctx)
6239 ssh->csmac->free_context(ssh->cs_mac_ctx);
6240 if (ssh->sc_mac_ctx)
6241 ssh->scmac->free_context(ssh->sc_mac_ctx);
6242 if (ssh->cs_comp_ctx)
6243 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6244 if (ssh->sc_comp_ctx)
6245 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6247 dh_cleanup(ssh->kex_ctx);
6248 sfree(ssh->savedhost);
6250 if (ssh->channels) {
6251 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6254 if (c->u.x11.s != NULL)
6255 x11_close(c->u.x11.s);
6258 if (c->u.pfd.s != NULL)
6259 pfd_close(c->u.pfd.s);
6264 freetree234(ssh->channels);
6267 if (ssh->rportfwds) {
6268 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6270 freetree234(ssh->rportfwds);
6272 sfree(ssh->deferred_send_data);
6274 x11_free_auth(ssh->x11auth);
6275 sfree(ssh->do_ssh_init_state);
6276 sfree(ssh->do_ssh1_login_state);
6277 sfree(ssh->do_ssh2_transport_state);
6278 sfree(ssh->do_ssh2_authconn_state);
6286 * Reconfigure the SSH backend.
6288 * Currently, this function does nothing very useful. In future,
6289 * however, we could do some handy things with it. For example, we
6290 * could make the port forwarding configurer active in the Change
6291 * Settings box, and this routine could close down existing
6292 * forwardings and open up new ones in response to changes.
6294 static void ssh_reconfig(void *handle, Config *cfg)
6296 Ssh ssh = (Ssh) handle;
6297 ssh->cfg = *cfg; /* STRUCTURE COPY */
6301 * Called to send data down the Telnet connection.
6303 static int ssh_send(void *handle, char *buf, int len)
6305 Ssh ssh = (Ssh) handle;
6307 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6310 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6312 return ssh_sendbuffer(ssh);
6316 * Called to query the current amount of buffered stdin data.
6318 static int ssh_sendbuffer(void *handle)
6320 Ssh ssh = (Ssh) handle;
6323 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6327 * If the SSH socket itself has backed up, add the total backup
6328 * size on that to any individual buffer on the stdin channel.
6331 if (ssh->throttled_all)
6332 override_value = ssh->overall_bufsize;
6334 if (ssh->version == 1) {
6335 return override_value;
6336 } else if (ssh->version == 2) {
6337 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6338 return override_value;
6340 return (override_value +
6341 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6348 * Called to set the size of the window from SSH's POV.
6350 static void ssh_size(void *handle, int width, int height)
6352 Ssh ssh = (Ssh) handle;
6354 ssh->term_width = width;
6355 ssh->term_height = height;
6357 switch (ssh->state) {
6358 case SSH_STATE_BEFORE_SIZE:
6359 case SSH_STATE_PREPACKET:
6360 case SSH_STATE_CLOSED:
6361 break; /* do nothing */
6362 case SSH_STATE_INTERMED:
6363 ssh->size_needed = TRUE; /* buffer for later */
6365 case SSH_STATE_SESSION:
6366 if (!ssh->cfg.nopty) {
6367 if (ssh->version == 1) {
6368 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6369 PKT_INT, ssh->term_height,
6370 PKT_INT, ssh->term_width,
6371 PKT_INT, 0, PKT_INT, 0, PKT_END);
6373 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6374 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6375 ssh2_pkt_addstring(ssh, "window-change");
6376 ssh2_pkt_addbool(ssh, 0);
6377 ssh2_pkt_adduint32(ssh, ssh->term_width);
6378 ssh2_pkt_adduint32(ssh, ssh->term_height);
6379 ssh2_pkt_adduint32(ssh, 0);
6380 ssh2_pkt_adduint32(ssh, 0);
6389 * Return a list of the special codes that make sense in this
6392 static const struct telnet_special *ssh_get_specials(void *handle)
6394 Ssh ssh = (Ssh) handle;
6396 if (ssh->version == 1) {
6397 static const struct telnet_special ssh1_specials[] = {
6398 {"IGNORE message", TS_NOP},
6401 return ssh1_specials;
6402 } else if (ssh->version == 2) {
6403 static const struct telnet_special ssh2_specials[] = {
6405 {"IGNORE message", TS_NOP},
6408 return ssh2_specials;
6414 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6415 * can send an EOF and collect resulting output (e.g. `plink
6418 static void ssh_special(void *handle, Telnet_Special code)
6420 Ssh ssh = (Ssh) handle;
6422 if (code == TS_EOF) {
6423 if (ssh->state != SSH_STATE_SESSION) {
6425 * Buffer the EOF in case we are pre-SESSION, so we can
6426 * send it as soon as we reach SESSION.
6429 ssh->eof_needed = TRUE;
6432 if (ssh->version == 1) {
6433 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6435 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6436 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6439 logevent("Sent EOF message");
6440 } else if (code == TS_PING || code == TS_NOP) {
6441 if (ssh->state == SSH_STATE_CLOSED
6442 || ssh->state == SSH_STATE_PREPACKET) return;
6443 if (ssh->version == 1) {
6444 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6445 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6447 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6448 ssh2_pkt_addstring_start(ssh);
6451 } else if (code == TS_BRK) {
6452 if (ssh->state == SSH_STATE_CLOSED
6453 || ssh->state == SSH_STATE_PREPACKET) return;
6454 if (ssh->version == 1) {
6455 logevent("Unable to send BREAK signal in SSH1");
6457 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6458 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6459 ssh2_pkt_addstring(ssh, "break");
6460 ssh2_pkt_addbool(ssh, 0);
6461 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6469 void *new_sock_channel(void *handle, Socket s)
6471 Ssh ssh = (Ssh) handle;
6472 struct ssh_channel *c;
6473 c = snew(struct ssh_channel);
6477 c->remoteid = -1; /* to be set when open confirmed */
6478 c->localid = alloc_channel_id(ssh);
6480 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6482 bufchain_init(&c->v.v2.outbuffer);
6483 add234(ssh->channels, c);
6489 * This is called when stdout/stderr (the entity to which
6490 * from_backend sends data) manages to clear some backlog.
6492 static void ssh_unthrottle(void *handle, int bufsize)
6494 Ssh ssh = (Ssh) handle;
6495 if (ssh->version == 1) {
6496 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6497 ssh->v1_stdout_throttling = 0;
6498 ssh1_throttle(ssh, -1);
6501 if (ssh->mainchan && ssh->mainchan->closes == 0)
6502 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6506 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6508 struct ssh_channel *c = (struct ssh_channel *)channel;
6511 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6513 if (ssh->version == 1) {
6514 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6515 PKT_INT, c->localid,
6518 //PKT_STR, <org:orgport>,
6521 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6522 ssh2_pkt_addstring(ssh, "direct-tcpip");
6523 ssh2_pkt_adduint32(ssh, c->localid);
6524 c->v.v2.locwindow = OUR_V2_WINSIZE;
6525 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6526 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6527 ssh2_pkt_addstring(ssh, hostname);
6528 ssh2_pkt_adduint32(ssh, port);
6530 * We make up values for the originator data; partly it's
6531 * too much hassle to keep track, and partly I'm not
6532 * convinced the server should be told details like that
6533 * about my local network configuration.
6535 ssh2_pkt_addstring(ssh, "client-side-connection");
6536 ssh2_pkt_adduint32(ssh, 0);
6542 static Socket ssh_socket(void *handle)
6544 Ssh ssh = (Ssh) handle;
6548 static int ssh_sendok(void *handle)
6550 Ssh ssh = (Ssh) handle;
6551 return ssh->send_ok;
6554 static int ssh_ldisc(void *handle, int option)
6556 Ssh ssh = (Ssh) handle;
6557 if (option == LD_ECHO)
6558 return ssh->echoing;
6559 if (option == LD_EDIT)
6560 return ssh->editing;
6564 static void ssh_provide_ldisc(void *handle, void *ldisc)
6566 Ssh ssh = (Ssh) handle;
6570 static void ssh_provide_logctx(void *handle, void *logctx)
6572 Ssh ssh = (Ssh) handle;
6573 ssh->logctx = logctx;
6576 static int ssh_return_exitcode(void *handle)
6578 Ssh ssh = (Ssh) handle;
6582 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6586 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6587 * that fails. This variable is the means by which scp.c can reach
6588 * into the SSH code and find out which one it got.
6590 extern int ssh_fallback_cmd(void *handle)
6592 Ssh ssh = (Ssh) handle;
6593 return ssh->fallback_cmd;
6596 Backend ssh_backend = {
6606 ssh_return_exitcode,