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 zlib_decompress_block(ssh->sc_comp_ctx,
872 ssh->pktin.body - 1, ssh->pktin.length + 1,
873 &decompblk, &decomplen);
875 if (ssh->pktin.maxlen < st->pad + decomplen) {
876 ssh->pktin.maxlen = st->pad + decomplen;
877 ssh->pktin.data = sresize(ssh->pktin.data,
878 ssh->pktin.maxlen + APIEXTRA,
880 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
883 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
885 ssh->pktin.length = decomplen - 1;
888 ssh->pktin.type = ssh->pktin.body[-1];
891 log_packet(ssh->logctx,
892 PKT_INCOMING, ssh->pktin.type,
893 ssh1_pkt_type(ssh->pktin.type),
894 ssh->pktin.body, ssh->pktin.length);
896 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
897 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
898 ssh->pktin.type == SSH1_MSG_DEBUG ||
899 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
900 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
901 long stringlen = GET_32BIT(ssh->pktin.body);
902 if (stringlen + 4 != ssh->pktin.length) {
903 bombout(("Received data packet with bogus string length"));
908 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
909 /* log debug message */
911 int stringlen = GET_32BIT(ssh->pktin.body);
912 strcpy(buf, "Remote debug message: ");
915 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
916 buf[8 + stringlen] = '\0';
919 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
924 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
925 /* log reason code in disconnect message */
927 unsigned msglen = GET_32BIT(ssh->pktin.body);
929 strcpy(buf, "Remote sent disconnect: ");
930 nowlen = strlen(buf);
931 if (msglen > sizeof(buf) - nowlen - 1)
932 msglen = sizeof(buf) - nowlen - 1;
933 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
934 buf[nowlen + msglen] = '\0';
935 /* logevent(buf); (this is now done within the bombout macro) */
936 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
943 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
945 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
947 crBegin(ssh->ssh2_rdpkt_crstate);
951 ssh->pktin.length = 0;
953 st->cipherblk = ssh->sccipher->blksize;
956 if (st->cipherblk < 8)
959 if (ssh->pktin.maxlen < st->cipherblk) {
960 ssh->pktin.maxlen = st->cipherblk;
961 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
966 * Acquire and decrypt the first block of the packet. This will
967 * contain the length and padding details.
969 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
970 while ((*datalen) == 0)
971 crReturn(st->cipherblk - st->i);
972 ssh->pktin.data[st->i] = *(*data)++;
977 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
978 ssh->pktin.data, st->cipherblk);
981 * Now get the length and padding figures.
983 st->len = GET_32BIT(ssh->pktin.data);
984 st->pad = ssh->pktin.data[4];
987 * _Completely_ silly lengths should be stomped on before they
988 * do us any more damage.
990 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
991 bombout(("Incoming packet was garbled on decryption"));
996 * This enables us to deduce the payload length.
998 st->payload = st->len - st->pad - 1;
1000 ssh->pktin.length = st->payload + 5;
1003 * So now we can work out the total packet length.
1005 st->packetlen = st->len + 4;
1006 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1009 * Adjust memory allocation if packet is too big.
1011 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1012 ssh->pktin.maxlen = st->packetlen + st->maclen;
1013 ssh->pktin.data = sresize(ssh->pktin.data,
1014 ssh->pktin.maxlen + APIEXTRA,
1019 * Read and decrypt the remainder of the packet.
1021 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1023 while ((*datalen) == 0)
1024 crReturn(st->packetlen + st->maclen - st->i);
1025 ssh->pktin.data[st->i] = *(*data)++;
1028 /* Decrypt everything _except_ the MAC. */
1030 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1031 ssh->pktin.data + st->cipherblk,
1032 st->packetlen - st->cipherblk);
1038 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1039 st->incoming_sequence)) {
1040 bombout(("Incorrect MAC received on packet"));
1043 st->incoming_sequence++; /* whether or not we MACed */
1046 * Decompress packet payload.
1049 unsigned char *newpayload;
1052 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1053 ssh->pktin.data + 5, ssh->pktin.length - 5,
1054 &newpayload, &newlen)) {
1055 if (ssh->pktin.maxlen < newlen + 5) {
1056 ssh->pktin.maxlen = newlen + 5;
1057 ssh->pktin.data = sresize(ssh->pktin.data,
1058 ssh->pktin.maxlen + APIEXTRA,
1061 ssh->pktin.length = 5 + newlen;
1062 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1067 ssh->pktin.savedpos = 6;
1068 ssh->pktin.type = ssh->pktin.data[5];
1071 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1072 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1073 ssh->pktin.data+6, ssh->pktin.length-6);
1075 switch (ssh->pktin.type) {
1077 * These packets we must handle instantly.
1079 case SSH2_MSG_DISCONNECT:
1081 /* log reason code in disconnect message */
1084 int reason = GET_32BIT(ssh->pktin.data + 6);
1085 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1087 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1088 buf = dupprintf("Received disconnect message (%s)",
1089 ssh2_disconnect_reasons[reason]);
1091 buf = dupprintf("Received disconnect message (unknown"
1092 " type %d)", reason);
1096 buf = dupprintf("Disconnection message text: %n%.*s",
1097 &nowlen, msglen, ssh->pktin.data + 14);
1099 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1101 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1102 ssh2_disconnect_reasons[reason] : "unknown",
1108 case SSH2_MSG_IGNORE:
1110 case SSH2_MSG_DEBUG:
1112 /* log the debug message */
1114 /* int display = ssh->pktin.body[6]; */
1115 int stringlen = GET_32BIT(ssh->pktin.data+7);
1117 strcpy(buf, "Remote debug message: ");
1118 prefix = strlen(buf);
1119 if (stringlen > (int)(sizeof(buf)-prefix-1))
1120 stringlen = sizeof(buf)-prefix-1;
1121 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1122 buf[prefix + stringlen] = '\0';
1125 goto next_packet; /* FIXME: print the debug message */
1128 * These packets we need do nothing about here.
1130 case SSH2_MSG_UNIMPLEMENTED:
1131 case SSH2_MSG_SERVICE_REQUEST:
1132 case SSH2_MSG_SERVICE_ACCEPT:
1133 case SSH2_MSG_KEXINIT:
1134 case SSH2_MSG_NEWKEYS:
1135 case SSH2_MSG_KEXDH_INIT:
1136 case SSH2_MSG_KEXDH_REPLY:
1137 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1138 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1139 case SSH2_MSG_KEX_DH_GEX_INIT:
1140 case SSH2_MSG_KEX_DH_GEX_REPLY:
1141 case SSH2_MSG_USERAUTH_REQUEST:
1142 case SSH2_MSG_USERAUTH_FAILURE:
1143 case SSH2_MSG_USERAUTH_SUCCESS:
1144 case SSH2_MSG_USERAUTH_BANNER:
1145 case SSH2_MSG_USERAUTH_PK_OK:
1146 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1147 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1148 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1149 case SSH2_MSG_GLOBAL_REQUEST:
1150 case SSH2_MSG_REQUEST_SUCCESS:
1151 case SSH2_MSG_REQUEST_FAILURE:
1152 case SSH2_MSG_CHANNEL_OPEN:
1153 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1154 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1155 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1156 case SSH2_MSG_CHANNEL_DATA:
1157 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1158 case SSH2_MSG_CHANNEL_EOF:
1159 case SSH2_MSG_CHANNEL_CLOSE:
1160 case SSH2_MSG_CHANNEL_REQUEST:
1161 case SSH2_MSG_CHANNEL_SUCCESS:
1162 case SSH2_MSG_CHANNEL_FAILURE:
1166 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1169 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1170 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1178 static void ssh1_pktout_size(Ssh ssh, int len)
1182 len += 5; /* type and CRC */
1183 pad = 8 - (len % 8);
1186 ssh->pktout.length = len - 5;
1187 if (ssh->pktout.maxlen < biglen) {
1188 ssh->pktout.maxlen = biglen;
1190 /* Allocate enough buffer space for extra block
1191 * for MS CryptEncrypt() */
1192 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1195 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1199 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1202 static void s_wrpkt_start(Ssh ssh, int type, int len)
1204 ssh1_pktout_size(ssh, len);
1205 ssh->pktout.type = type;
1208 static int s_wrpkt_prepare(Ssh ssh)
1214 * XXX various versions of SC (including 8.8.4) screw up the
1215 * register allocation in this function and use the same register
1216 * (D6) for len and as a temporary, with predictable results. The
1217 * following sledgehammer prevents this.
1223 ssh->pktout.body[-1] = ssh->pktout.type;
1226 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1227 ssh1_pkt_type(ssh->pktout.type),
1228 ssh->pktout.body, ssh->pktout.length);
1230 if (ssh->v1_compressing) {
1231 unsigned char *compblk;
1233 zlib_compress_block(ssh->cs_comp_ctx,
1234 ssh->pktout.body - 1, ssh->pktout.length + 1,
1235 &compblk, &complen);
1236 ssh1_pktout_size(ssh, complen - 1);
1237 memcpy(ssh->pktout.body - 1, compblk, complen);
1241 len = ssh->pktout.length + 5; /* type and CRC */
1242 pad = 8 - (len % 8);
1245 for (i = 0; i < pad; i++)
1246 ssh->pktout.data[i + 4] = random_byte();
1247 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1248 PUT_32BIT(ssh->pktout.data + biglen, crc);
1249 PUT_32BIT(ssh->pktout.data, len);
1252 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1257 static void s_wrpkt(Ssh ssh)
1260 len = s_wrpkt_prepare(ssh);
1261 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1262 if (backlog > SSH_MAX_BACKLOG)
1263 ssh_throttle_all(ssh, 1, backlog);
1266 static void s_wrpkt_defer(Ssh ssh)
1269 len = s_wrpkt_prepare(ssh);
1270 if (ssh->deferred_len + len > ssh->deferred_size) {
1271 ssh->deferred_size = ssh->deferred_len + len + 128;
1272 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1276 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1277 ssh->deferred_len += len;
1281 * Construct a packet with the specified contents.
1283 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1285 unsigned char *p, *argp, argchar;
1286 unsigned long argint;
1287 int pktlen, argtype, arglen;
1291 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1294 (void) va_arg(ap1, int);
1298 (void) va_arg(ap1, int);
1302 (void) va_arg(ap1, unsigned char *);
1303 arglen = va_arg(ap1, int);
1307 argp = va_arg(ap1, unsigned char *);
1308 arglen = strlen((char *)argp);
1309 pktlen += 4 + arglen;
1312 bn = va_arg(ap1, Bignum);
1313 pktlen += ssh1_bignum_length(bn);
1320 s_wrpkt_start(ssh, pkttype, pktlen);
1321 p = ssh->pktout.body;
1323 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1326 argint = va_arg(ap2, int);
1327 PUT_32BIT(p, argint);
1331 argchar = (unsigned char) va_arg(ap2, int);
1336 argp = va_arg(ap2, unsigned char *);
1337 arglen = va_arg(ap2, int);
1338 memcpy(p, argp, arglen);
1342 argp = va_arg(ap2, unsigned char *);
1343 arglen = strlen((char *)argp);
1344 PUT_32BIT(p, arglen);
1345 memcpy(p + 4, argp, arglen);
1349 bn = va_arg(ap2, Bignum);
1350 p += ssh1_write_bignum(p, bn);
1356 static void send_packet(Ssh ssh, int pkttype, ...)
1359 va_start(ap1, pkttype);
1360 va_start(ap2, pkttype);
1361 construct_packet(ssh, pkttype, ap1, ap2);
1365 static void defer_packet(Ssh ssh, int pkttype, ...)
1368 va_start(ap1, pkttype);
1369 va_start(ap2, pkttype);
1370 construct_packet(ssh, pkttype, ap1, ap2);
1374 static int ssh_versioncmp(char *a, char *b)
1377 unsigned long av, bv;
1379 av = strtoul(a, &ae, 10);
1380 bv = strtoul(b, &be, 10);
1382 return (av < bv ? -1 : +1);
1387 av = strtoul(ae, &ae, 10);
1388 bv = strtoul(be, &be, 10);
1390 return (av < bv ? -1 : +1);
1395 * Utility routines for putting an SSH-protocol `string' and
1396 * `uint32' into a SHA state.
1399 static void sha_string(SHA_State * s, void *str, int len)
1401 unsigned char lenblk[4];
1402 PUT_32BIT(lenblk, len);
1403 SHA_Bytes(s, lenblk, 4);
1404 SHA_Bytes(s, str, len);
1407 static void sha_uint32(SHA_State * s, unsigned i)
1409 unsigned char intblk[4];
1410 PUT_32BIT(intblk, i);
1411 SHA_Bytes(s, intblk, 4);
1415 * SSH2 packet construction functions.
1417 static void ssh2_pkt_ensure(Ssh ssh, int length)
1419 if (ssh->pktout.maxlen < length) {
1420 ssh->pktout.maxlen = length + 256;
1421 ssh->pktout.data = sresize(ssh->pktout.data,
1422 ssh->pktout.maxlen + APIEXTRA,
1424 if (!ssh->pktout.data)
1425 fatalbox("Out of memory");
1428 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1430 ssh->pktout.length += len;
1431 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1432 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1434 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1436 ssh2_pkt_adddata(ssh, &byte, 1);
1438 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1440 ssh->pktout.length = 5;
1441 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1443 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1445 ssh2_pkt_adddata(ssh, &value, 1);
1447 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1450 PUT_32BIT(x, value);
1451 ssh2_pkt_adddata(ssh, x, 4);
1453 static void ssh2_pkt_addstring_start(Ssh ssh)
1455 ssh2_pkt_adduint32(ssh, 0);
1456 ssh->pktout.savedpos = ssh->pktout.length;
1458 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1460 ssh2_pkt_adddata(ssh, data, strlen(data));
1461 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1462 ssh->pktout.length - ssh->pktout.savedpos);
1464 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1466 ssh2_pkt_adddata(ssh, data, len);
1467 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1468 ssh->pktout.length - ssh->pktout.savedpos);
1470 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1472 ssh2_pkt_addstring_start(ssh);
1473 ssh2_pkt_addstring_str(ssh, data);
1475 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1478 int i, n = (bignum_bitcount(b) + 7) / 8;
1479 p = snewn(n + 1, unsigned char);
1481 fatalbox("out of memory");
1483 for (i = 1; i <= n; i++)
1484 p[i] = bignum_byte(b, n - i);
1486 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1488 memmove(p, p + i, n + 1 - i);
1492 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1496 p = ssh2_mpint_fmt(b, &len);
1497 ssh2_pkt_addstring_start(ssh);
1498 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1503 * Construct an SSH2 final-form packet: compress it, encrypt it,
1504 * put the MAC on it. Final packet, ready to be sent, is stored in
1505 * ssh->pktout.data. Total length is returned.
1507 static int ssh2_pkt_construct(Ssh ssh)
1509 int cipherblk, maclen, padding, i;
1512 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1513 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1514 ssh->pktout.data + 6, ssh->pktout.length - 6);
1517 * Compress packet payload.
1520 unsigned char *newpayload;
1523 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1524 ssh->pktout.length - 5,
1525 &newpayload, &newlen)) {
1526 ssh->pktout.length = 5;
1527 ssh2_pkt_adddata(ssh, newpayload, newlen);
1533 * Add padding. At least four bytes, and must also bring total
1534 * length (minus MAC) up to a multiple of the block size.
1536 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1537 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1540 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1541 maclen = ssh->csmac ? ssh->csmac->len : 0;
1542 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1543 ssh->pktout.data[4] = padding;
1544 for (i = 0; i < padding; i++)
1545 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1546 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1548 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1549 ssh->pktout.length + padding,
1550 ssh->v2_outgoing_sequence);
1551 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1554 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1555 ssh->pktout.data, ssh->pktout.length + padding);
1557 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1558 return ssh->pktout.length + padding + maclen;
1562 * Construct and send an SSH2 packet immediately.
1564 static void ssh2_pkt_send(Ssh ssh)
1568 len = ssh2_pkt_construct(ssh);
1569 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1570 if (backlog > SSH_MAX_BACKLOG)
1571 ssh_throttle_all(ssh, 1, backlog);
1575 * Construct an SSH2 packet and add it to a deferred data block.
1576 * Useful for sending multiple packets in a single sk_write() call,
1577 * to prevent a traffic-analysing listener from being able to work
1578 * out the length of any particular packet (such as the password
1581 * Note that because SSH2 sequence-numbers its packets, this can
1582 * NOT be used as an m4-style `defer' allowing packets to be
1583 * constructed in one order and sent in another.
1585 static void ssh2_pkt_defer(Ssh ssh)
1587 int len = ssh2_pkt_construct(ssh);
1588 if (ssh->deferred_len + len > ssh->deferred_size) {
1589 ssh->deferred_size = ssh->deferred_len + len + 128;
1590 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1594 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1595 ssh->deferred_len += len;
1599 * Send the whole deferred data block constructed by
1600 * ssh2_pkt_defer() or SSH1's defer_packet().
1602 static void ssh_pkt_defersend(Ssh ssh)
1605 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1607 ssh->deferred_len = ssh->deferred_size = 0;
1608 sfree(ssh->deferred_send_data);
1609 ssh->deferred_send_data = NULL;
1610 if (backlog > SSH_MAX_BACKLOG)
1611 ssh_throttle_all(ssh, 1, backlog);
1615 void bndebug(char *string, Bignum b)
1619 p = ssh2_mpint_fmt(b, &len);
1620 debug(("%s", string));
1621 for (i = 0; i < len; i++)
1622 debug((" %02x", p[i]));
1628 static void sha_mpint(SHA_State * s, Bignum b)
1632 p = ssh2_mpint_fmt(b, &len);
1633 sha_string(s, p, len);
1638 * SSH2 packet decode functions.
1640 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1642 unsigned long value;
1643 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1644 return 0; /* arrgh, no way to decline (FIXME?) */
1645 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1646 ssh->pktin.savedpos += 4;
1649 static int ssh2_pkt_getbool(Ssh ssh)
1651 unsigned long value;
1652 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1653 return 0; /* arrgh, no way to decline (FIXME?) */
1654 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1655 ssh->pktin.savedpos++;
1658 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1663 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1665 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1669 ssh->pktin.savedpos += 4;
1670 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1672 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1673 ssh->pktin.savedpos += *length;
1675 static Bignum ssh2_pkt_getmp(Ssh ssh)
1681 ssh2_pkt_getstring(ssh, &p, &length);
1685 bombout(("internal error: Can't handle negative mpints"));
1688 b = bignum_from_bytes((unsigned char *)p, length);
1693 * Helper function to add an SSH2 signature blob to a packet.
1694 * Expects to be shown the public key blob as well as the signature
1695 * blob. Normally works just like ssh2_pkt_addstring, but will
1696 * fiddle with the signature packet if necessary for
1697 * BUG_SSH2_RSA_PADDING.
1699 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1700 void *sigblob_v, int sigblob_len)
1702 unsigned char *pkblob = (unsigned char *)pkblob_v;
1703 unsigned char *sigblob = (unsigned char *)sigblob_v;
1705 /* dmemdump(pkblob, pkblob_len); */
1706 /* dmemdump(sigblob, sigblob_len); */
1709 * See if this is in fact an ssh-rsa signature and a buggy
1710 * server; otherwise we can just do this the easy way.
1712 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1713 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1714 int pos, len, siglen;
1717 * Find the byte length of the modulus.
1720 pos = 4+7; /* skip over "ssh-rsa" */
1721 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1722 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1723 pos += 4; /* find modulus itself */
1724 while (len > 0 && pkblob[pos] == 0)
1726 /* debug(("modulus length is %d\n", len)); */
1729 * Now find the signature integer.
1731 pos = 4+7; /* skip over "ssh-rsa" */
1732 siglen = GET_32BIT(sigblob+pos);
1733 /* debug(("signature length is %d\n", siglen)); */
1735 if (len != siglen) {
1736 unsigned char newlen[4];
1737 ssh2_pkt_addstring_start(ssh);
1738 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1739 /* dmemdump(sigblob, pos); */
1740 pos += 4; /* point to start of actual sig */
1741 PUT_32BIT(newlen, len);
1742 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1743 /* dmemdump(newlen, 4); */
1745 while (len-- > siglen) {
1746 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1747 /* dmemdump(newlen, 1); */
1749 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1750 /* dmemdump(sigblob+pos, siglen); */
1754 /* Otherwise fall through and do it the easy way. */
1757 ssh2_pkt_addstring_start(ssh);
1758 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1762 * Examine the remote side's version string and compare it against
1763 * a list of known buggy implementations.
1765 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1767 char *imp; /* pointer to implementation part */
1769 imp += strcspn(imp, "-");
1771 imp += strcspn(imp, "-");
1774 ssh->remote_bugs = 0;
1776 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1777 (ssh->cfg.sshbug_ignore1 == AUTO &&
1778 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1779 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1780 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1782 * These versions don't support SSH1_MSG_IGNORE, so we have
1783 * to use a different defence against password length
1786 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1787 logevent("We believe remote version has SSH1 ignore bug");
1790 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1791 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1792 (!strcmp(imp, "Cisco-1.25")))) {
1794 * These versions need a plain password sent; they can't
1795 * handle having a null and a random length of data after
1798 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1799 logevent("We believe remote version needs a plain SSH1 password");
1802 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1803 (ssh->cfg.sshbug_rsa1 == AUTO &&
1804 (!strcmp(imp, "Cisco-1.25")))) {
1806 * These versions apparently have no clue whatever about
1807 * RSA authentication and will panic and die if they see
1808 * an AUTH_RSA message.
1810 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1811 logevent("We believe remote version can't handle RSA authentication");
1814 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1815 (ssh->cfg.sshbug_hmac2 == AUTO &&
1816 !wc_match("* VShell", imp) &&
1817 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1818 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1819 wc_match("2.1 *", imp)))) {
1821 * These versions have the HMAC bug.
1823 ssh->remote_bugs |= BUG_SSH2_HMAC;
1824 logevent("We believe remote version has SSH2 HMAC bug");
1827 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1828 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1829 !wc_match("* VShell", imp) &&
1830 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1832 * These versions have the key-derivation bug (failing to
1833 * include the literal shared secret in the hashes that
1834 * generate the keys).
1836 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1837 logevent("We believe remote version has SSH2 key-derivation bug");
1840 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1841 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1842 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1843 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1845 * These versions have the SSH2 RSA padding bug.
1847 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1848 logevent("We believe remote version has SSH2 RSA padding bug");
1851 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1852 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1853 wc_match("OpenSSH_2.[0-2]*", imp))) {
1855 * These versions have the SSH2 session-ID bug in
1856 * public-key authentication.
1858 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1859 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1862 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1864 * User specified the SSH2 DH GEX bug.
1866 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1867 logevent("We believe remote version has SSH2 DH group exchange bug");
1871 static int do_ssh_init(Ssh ssh, unsigned char c)
1873 struct do_ssh_init_state {
1881 crState(do_ssh_init_state);
1883 crBegin(ssh->do_ssh_init_crstate);
1885 /* Search for the string "SSH-" in the input. */
1888 static const int transS[] = { 1, 2, 2, 1 };
1889 static const int transH[] = { 0, 0, 3, 0 };
1890 static const int transminus[] = { 0, 0, 0, -1 };
1892 s->i = transS[s->i];
1894 s->i = transH[s->i];
1896 s->i = transminus[s->i];
1901 crReturn(1); /* get another character */
1905 s->vstring = snewn(s->vstrsize, char);
1906 strcpy(s->vstring, "SSH-");
1910 crReturn(1); /* get another char */
1911 if (s->vslen >= s->vstrsize - 1) {
1913 s->vstring = sresize(s->vstring, s->vstrsize, char);
1915 s->vstring[s->vslen++] = c;
1918 s->version[s->i] = '\0';
1920 } else if (s->i < sizeof(s->version) - 1)
1921 s->version[s->i++] = c;
1922 } else if (c == '\012')
1926 ssh->agentfwd_enabled = FALSE;
1927 ssh->rdpkt2_state.incoming_sequence = 0;
1929 s->vstring[s->vslen] = 0;
1930 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1933 vlog = snewn(20 + s->vslen, char);
1934 sprintf(vlog, "Server version: %s", s->vstring);
1938 ssh_detect_bugs(ssh, s->vstring);
1941 * Decide which SSH protocol version to support.
1944 /* Anything strictly below "2.0" means protocol 1 is supported. */
1945 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1946 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1947 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1949 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1950 bombout(("SSH protocol version 1 required by user but not provided by server"));
1953 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1954 bombout(("SSH protocol version 2 required by user but not provided by server"));
1958 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1962 char verstring[80], vlog[100];
1963 sprintf(verstring, "SSH-2.0-%s", sshver);
1964 SHA_Init(&ssh->exhashbase);
1966 * Hash our version string and their version string.
1968 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1969 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1970 sprintf(vlog, "We claim version: %s", verstring);
1972 strcat(verstring, "\012");
1973 logevent("Using SSH protocol version 2");
1974 sk_write(ssh->s, verstring, strlen(verstring));
1975 ssh->protocol = ssh2_protocol;
1977 ssh->s_rdpkt = ssh2_rdpkt;
1982 char verstring[80], vlog[100];
1983 sprintf(verstring, "SSH-%s-%s",
1984 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1986 sprintf(vlog, "We claim version: %s", verstring);
1988 strcat(verstring, "\012");
1990 logevent("Using SSH protocol version 1");
1991 sk_write(ssh->s, verstring, strlen(verstring));
1992 ssh->protocol = ssh1_protocol;
1994 ssh->s_rdpkt = ssh1_rdpkt;
1996 update_specials_menu(ssh->frontend);
1997 ssh->state = SSH_STATE_BEFORE_SIZE;
2004 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2006 crBegin(ssh->ssh_gotdata_crstate);
2009 * To begin with, feed the characters one by one to the
2010 * protocol initialisation / selection function do_ssh_init().
2011 * When that returns 0, we're done with the initial greeting
2012 * exchange and can move on to packet discipline.
2015 int ret; /* need not be kept across crReturn */
2017 crReturnV; /* more data please */
2018 ret = do_ssh_init(ssh, *data);
2026 * We emerge from that loop when the initial negotiation is
2027 * over and we have selected an s_rdpkt function. Now pass
2028 * everything to s_rdpkt, and then pass the resulting packets
2029 * to the proper protocol handler.
2034 while (datalen > 0) {
2035 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2036 if (ssh->state == SSH_STATE_CLOSED) {
2039 ssh->protocol(ssh, NULL, 0, 1);
2040 if (ssh->state == SSH_STATE_CLOSED) {
2050 static void ssh_do_close(Ssh ssh)
2053 struct ssh_channel *c;
2055 ssh->state = SSH_STATE_CLOSED;
2061 * Now we must shut down any port and X forwardings going
2062 * through this connection.
2064 if (ssh->channels) {
2065 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2068 x11_close(c->u.x11.s);
2071 pfd_close(c->u.pfd.s);
2074 del234(ssh->channels, c);
2075 if (ssh->version == 2)
2076 bufchain_clear(&c->v.v2.outbuffer);
2082 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2085 Ssh ssh = (Ssh) plug;
2088 /* A socket error has occurred. */
2089 logevent(error_msg);
2090 connection_fatal(ssh->frontend, "%s", error_msg);
2092 /* Otherwise, the remote side closed the connection normally. */
2097 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2099 Ssh ssh = (Ssh) plug;
2100 ssh_gotdata(ssh, (unsigned char *)data, len);
2101 if (ssh->state == SSH_STATE_CLOSED) {
2108 static void ssh_sent(Plug plug, int bufsize)
2110 Ssh ssh = (Ssh) plug;
2112 * If the send backlog on the SSH socket itself clears, we
2113 * should unthrottle the whole world if it was throttled.
2115 if (bufsize < SSH_MAX_BACKLOG)
2116 ssh_throttle_all(ssh, 0, bufsize);
2120 * Connect to specified host and port.
2121 * Returns an error message, or NULL on success.
2122 * Also places the canonical host name into `realhost'. It must be
2123 * freed by the caller.
2125 static const char *connect_to_host(Ssh ssh, char *host, int port,
2126 char **realhost, int nodelay)
2128 static const struct plug_function_table fn_table = {
2138 ssh->savedhost = snewn(1 + strlen(host), char);
2139 if (!ssh->savedhost)
2140 fatalbox("Out of memory");
2141 strcpy(ssh->savedhost, host);
2144 port = 22; /* default ssh port */
2145 ssh->savedport = port;
2150 logeventf(ssh, "Looking up host \"%s\"", host);
2151 addr = name_lookup(host, port, realhost, &ssh->cfg);
2152 if ((err = sk_addr_error(addr)) != NULL)
2160 sk_getaddr(addr, addrbuf, 100);
2161 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2163 ssh->fn = &fn_table;
2164 ssh->s = new_connection(addr, *realhost, port,
2165 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2166 if ((err = sk_socket_error(ssh->s)) != NULL) {
2175 * Throttle or unthrottle the SSH connection.
2177 static void ssh1_throttle(Ssh ssh, int adjust)
2179 int old_count = ssh->v1_throttle_count;
2180 ssh->v1_throttle_count += adjust;
2181 assert(ssh->v1_throttle_count >= 0);
2182 if (ssh->v1_throttle_count && !old_count) {
2183 sk_set_frozen(ssh->s, 1);
2184 } else if (!ssh->v1_throttle_count && old_count) {
2185 sk_set_frozen(ssh->s, 0);
2190 * Throttle or unthrottle _all_ local data streams (for when sends
2191 * on the SSH connection itself back up).
2193 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2196 struct ssh_channel *c;
2198 if (enable == ssh->throttled_all)
2200 ssh->throttled_all = enable;
2201 ssh->overall_bufsize = bufsize;
2204 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2206 case CHAN_MAINSESSION:
2208 * This is treated separately, outside the switch.
2212 x11_override_throttle(c->u.x11.s, enable);
2215 /* Agent channels require no buffer management. */
2218 pfd_override_throttle(c->u.pfd.s, enable);
2225 * Username and password input, abstracted off into routines
2226 * reusable in several places - even between SSH1 and SSH2.
2229 /* Set up a username or password input loop on a given buffer. */
2230 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2232 ssh->userpass_input_buffer = buffer;
2233 ssh->userpass_input_buflen = buflen;
2234 ssh->userpass_input_bufpos = 0;
2235 ssh->userpass_input_echo = echo;
2239 * Process some terminal data in the course of username/password
2240 * input. Returns >0 for success (line of input returned in
2241 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2242 * for inconclusive (keep waiting for more input please).
2244 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2249 switch (c = *in++) {
2252 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2253 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2258 if (ssh->userpass_input_bufpos > 0) {
2259 if (ssh->userpass_input_echo)
2260 c_write_str(ssh, "\b \b");
2261 ssh->userpass_input_bufpos--;
2266 while (ssh->userpass_input_bufpos > 0) {
2267 if (ssh->userpass_input_echo)
2268 c_write_str(ssh, "\b \b");
2269 ssh->userpass_input_bufpos--;
2278 * This simplistic check for printability is disabled
2279 * when we're doing password input, because some people
2280 * have control characters in their passwords.o
2282 if ((!ssh->userpass_input_echo ||
2283 (c >= ' ' && c <= '~') ||
2284 ((unsigned char) c >= 160))
2285 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2286 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2287 if (ssh->userpass_input_echo)
2288 c_write(ssh, &c, 1);
2296 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2298 Ssh ssh = (Ssh) sshv;
2300 ssh->agent_response = reply;
2301 ssh->agent_response_len = replylen;
2303 if (ssh->version == 1)
2304 do_ssh1_login(ssh, NULL, -1, 0);
2306 do_ssh2_authconn(ssh, NULL, -1, 0);
2309 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2311 struct ssh_channel *c = (struct ssh_channel *)cv;
2313 void *sentreply = reply;
2316 /* Fake SSH_AGENT_FAILURE. */
2317 sentreply = "\0\0\0\1\5";
2320 if (ssh->version == 2) {
2321 ssh2_add_channel_data(c, sentreply, replylen);
2324 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2325 PKT_INT, c->remoteid,
2327 PKT_DATA, sentreply, replylen,
2335 * Handle the key exchange and user authentication phases.
2337 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2340 unsigned char cookie[8];
2341 struct RSAKey servkey, hostkey;
2342 struct MD5Context md5c;
2343 struct do_ssh1_login_state {
2345 unsigned char *rsabuf, *keystr1, *keystr2;
2346 unsigned long supported_ciphers_mask, supported_auths_mask;
2347 int tried_publickey, tried_agent;
2348 int tis_auth_refused, ccard_auth_refused;
2349 unsigned char session_id[16];
2352 void *publickey_blob;
2353 int publickey_bloblen;
2359 unsigned char request[5], *response, *p;
2368 crState(do_ssh1_login_state);
2370 crBegin(ssh->do_ssh1_login_crstate);
2375 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2376 bombout(("Public key packet not received"));
2380 logevent("Received public keys");
2382 memcpy(cookie, ssh->pktin.body, 8);
2384 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2385 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2388 * Log the host key fingerprint.
2392 logevent("Host key fingerprint is:");
2393 strcpy(logmsg, " ");
2394 hostkey.comment = NULL;
2395 rsa_fingerprint(logmsg + strlen(logmsg),
2396 sizeof(logmsg) - strlen(logmsg), &hostkey);
2400 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2401 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2402 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2404 ssh->v1_local_protoflags =
2405 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2406 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2409 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2410 MD5Update(&md5c, s->keystr1, servkey.bytes);
2411 MD5Update(&md5c, ssh->pktin.body, 8);
2412 MD5Final(s->session_id, &md5c);
2414 for (i = 0; i < 32; i++)
2415 ssh->session_key[i] = random_byte();
2417 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2419 s->rsabuf = snewn(s->len, unsigned char);
2421 fatalbox("Out of memory");
2424 * Verify the host key.
2428 * First format the key into a string.
2430 int len = rsastr_len(&hostkey);
2431 char fingerprint[100];
2432 char *keystr = snewn(len, char);
2434 fatalbox("Out of memory");
2435 rsastr_fmt(keystr, &hostkey);
2436 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2437 verify_ssh_host_key(ssh->frontend,
2438 ssh->savedhost, ssh->savedport, "rsa", keystr,
2443 for (i = 0; i < 32; i++) {
2444 s->rsabuf[i] = ssh->session_key[i];
2446 s->rsabuf[i] ^= s->session_id[i];
2449 if (hostkey.bytes > servkey.bytes) {
2450 rsaencrypt(s->rsabuf, 32, &servkey);
2451 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2453 rsaencrypt(s->rsabuf, 32, &hostkey);
2454 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2457 logevent("Encrypted session key");
2460 int cipher_chosen = 0, warn = 0;
2461 char *cipher_string = NULL;
2463 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2464 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2465 if (next_cipher == CIPHER_WARN) {
2466 /* If/when we choose a cipher, warn about it */
2468 } else if (next_cipher == CIPHER_AES) {
2469 /* XXX Probably don't need to mention this. */
2470 logevent("AES not supported in SSH1, skipping");
2472 switch (next_cipher) {
2473 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2474 cipher_string = "3DES"; break;
2475 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2476 cipher_string = "Blowfish"; break;
2477 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2478 cipher_string = "single-DES"; break;
2480 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2484 if (!cipher_chosen) {
2485 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2486 bombout(("Server violates SSH 1 protocol by not "
2487 "supporting 3DES encryption"));
2489 /* shouldn't happen */
2490 bombout(("No supported ciphers found"));
2494 /* Warn about chosen cipher if necessary. */
2496 askcipher(ssh->frontend, cipher_string, 0);
2499 switch (s->cipher_type) {
2500 case SSH_CIPHER_3DES:
2501 logevent("Using 3DES encryption");
2503 case SSH_CIPHER_DES:
2504 logevent("Using single-DES encryption");
2506 case SSH_CIPHER_BLOWFISH:
2507 logevent("Using Blowfish encryption");
2511 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2512 PKT_CHAR, s->cipher_type,
2513 PKT_DATA, cookie, 8,
2514 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2515 PKT_DATA, s->rsabuf, s->len,
2516 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2518 logevent("Trying to enable encryption...");
2522 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2523 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2525 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2526 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2527 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2529 ssh->crcda_ctx = crcda_make_context();
2530 logevent("Installing CRC compensation attack detector");
2534 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2535 bombout(("Encryption not successfully enabled"));
2539 logevent("Successfully started encryption");
2543 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2544 if (ssh_get_line && !ssh_getline_pw_only) {
2545 if (!ssh_get_line("login as: ",
2546 s->username, sizeof(s->username), FALSE)) {
2548 * get_line failed to get a username.
2551 logevent("No username provided. Abandoning session.");
2552 ssh_closing((Plug)ssh, NULL, 0, 0);
2556 int ret; /* need not be kept over crReturn */
2557 c_write_str(ssh, "login as: ");
2560 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2562 crWaitUntil(!ispkt);
2563 ret = process_userpass_input(ssh, in, inlen);
2567 c_write_str(ssh, "\r\n");
2570 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2571 s->username[sizeof(s->username)-1] = '\0';
2574 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2576 char userlog[22 + sizeof(s->username)];
2577 sprintf(userlog, "Sent username \"%s\"", s->username);
2579 if (flags & FLAG_INTERACTIVE &&
2580 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2581 strcat(userlog, "\r\n");
2582 c_write_str(ssh, userlog);
2589 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2590 /* We must not attempt PK auth. Pretend we've already tried it. */
2591 s->tried_publickey = s->tried_agent = 1;
2593 s->tried_publickey = s->tried_agent = 0;
2595 s->tis_auth_refused = s->ccard_auth_refused = 0;
2596 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2597 if (!filename_is_null(ssh->cfg.keyfile)) {
2598 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2599 &s->publickey_blob, &s->publickey_bloblen))
2600 s->publickey_blob = NULL;
2602 s->publickey_blob = NULL;
2604 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2605 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2607 if (agent_exists() && !s->tried_agent) {
2609 * Attempt RSA authentication using Pageant.
2615 logevent("Pageant is running. Requesting keys.");
2617 /* Request the keys held by the agent. */
2618 PUT_32BIT(s->request, 1);
2619 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2620 if (!agent_query(s->request, 5, &r, &s->responselen,
2621 ssh_agent_callback, ssh)) {
2625 bombout(("Unexpected data from server while waiting"
2626 " for agent response"));
2629 } while (ispkt || inlen > 0);
2630 r = ssh->agent_response;
2631 s->responselen = ssh->agent_response_len;
2633 s->response = (unsigned char *) r;
2634 if (s->response && s->responselen >= 5 &&
2635 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2636 s->p = s->response + 5;
2637 s->nkeys = GET_32BIT(s->p);
2641 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2644 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2647 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2650 if (s->publickey_blob &&
2651 !memcmp(s->p, s->publickey_blob,
2652 s->publickey_bloblen)) {
2653 logevent("This key matches configured key file");
2654 s->tried_publickey = 1;
2657 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2658 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2659 s->commentlen = GET_32BIT(s->p);
2661 s->commentp = (char *)s->p;
2662 s->p += s->commentlen;
2663 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2664 PKT_BIGNUM, s->key.modulus, PKT_END);
2666 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2667 logevent("Key refused");
2670 logevent("Received RSA challenge");
2671 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2673 char *agentreq, *q, *ret;
2676 len = 1 + 4; /* message type, bit count */
2677 len += ssh1_bignum_length(s->key.exponent);
2678 len += ssh1_bignum_length(s->key.modulus);
2679 len += ssh1_bignum_length(s->challenge);
2680 len += 16; /* session id */
2681 len += 4; /* response format */
2682 agentreq = snewn(4 + len, char);
2683 PUT_32BIT(agentreq, len);
2685 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2686 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2688 q += ssh1_write_bignum(q, s->key.exponent);
2689 q += ssh1_write_bignum(q, s->key.modulus);
2690 q += ssh1_write_bignum(q, s->challenge);
2691 memcpy(q, s->session_id, 16);
2693 PUT_32BIT(q, 1); /* response format */
2694 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2695 ssh_agent_callback, ssh)) {
2700 bombout(("Unexpected data from server"
2701 " while waiting for agent"
2705 } while (ispkt || inlen > 0);
2706 vret = ssh->agent_response;
2707 retlen = ssh->agent_response_len;
2712 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2713 logevent("Sending Pageant's response");
2714 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2715 PKT_DATA, ret + 5, 16,
2719 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2721 ("Pageant's response accepted");
2722 if (flags & FLAG_VERBOSE) {
2723 c_write_str(ssh, "Authenticated using"
2725 c_write(ssh, s->commentp,
2727 c_write_str(ssh, "\" from agent\r\n");
2732 ("Pageant's response not accepted");
2735 ("Pageant failed to answer challenge");
2739 logevent("No reply received from Pageant");
2742 freebn(s->key.exponent);
2743 freebn(s->key.modulus);
2744 freebn(s->challenge);
2752 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2753 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2755 if (ssh->cfg.try_tis_auth &&
2756 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2757 !s->tis_auth_refused) {
2758 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2759 logevent("Requested TIS authentication");
2760 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2762 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2763 logevent("TIS authentication declined");
2764 if (flags & FLAG_INTERACTIVE)
2765 c_write_str(ssh, "TIS authentication refused.\r\n");
2766 s->tis_auth_refused = 1;
2769 int challengelen = GET_32BIT(ssh->pktin.body);
2770 logevent("Received TIS challenge");
2771 if (challengelen > sizeof(s->prompt) - 1)
2772 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2773 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2774 /* Prompt heuristic comes from OpenSSH */
2775 strncpy(s->prompt + challengelen,
2776 memchr(s->prompt, '\n', challengelen) ?
2777 "": "\r\nResponse: ",
2778 (sizeof s->prompt) - challengelen);
2779 s->prompt[(sizeof s->prompt) - 1] = '\0';
2782 if (ssh->cfg.try_tis_auth &&
2783 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2784 !s->ccard_auth_refused) {
2785 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2786 logevent("Requested CryptoCard authentication");
2787 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2789 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2790 logevent("CryptoCard authentication declined");
2791 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2792 s->ccard_auth_refused = 1;
2795 int challengelen = GET_32BIT(ssh->pktin.body);
2796 logevent("Received CryptoCard challenge");
2797 if (challengelen > sizeof(s->prompt) - 1)
2798 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2799 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2800 strncpy(s->prompt + challengelen,
2801 memchr(s->prompt, '\n', challengelen) ?
2802 "" : "\r\nResponse: ",
2803 sizeof(s->prompt) - challengelen);
2804 s->prompt[sizeof(s->prompt) - 1] = '\0';
2807 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2808 sprintf(s->prompt, "%.90s@%.90s's password: ",
2809 s->username, ssh->savedhost);
2811 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2812 char *comment = NULL;
2815 if (flags & FLAG_VERBOSE)
2816 c_write_str(ssh, "Trying public key authentication.\r\n");
2817 logeventf(ssh, "Trying public key \"%s\"",
2818 filename_to_str(&ssh->cfg.keyfile));
2819 type = key_type(&ssh->cfg.keyfile);
2820 if (type != SSH_KEYTYPE_SSH1) {
2821 sprintf(msgbuf, "Key is of wrong type (%s)",
2822 key_type_to_str(type));
2824 c_write_str(ssh, msgbuf);
2825 c_write_str(ssh, "\r\n");
2826 s->tried_publickey = 1;
2829 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2830 if (flags & FLAG_VERBOSE)
2831 c_write_str(ssh, "No passphrase required.\r\n");
2834 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2839 * Show password prompt, having first obtained it via a TIS
2840 * or CryptoCard exchange if we're doing TIS or CryptoCard
2844 if (!ssh_get_line(s->prompt, s->password,
2845 sizeof(s->password), TRUE)) {
2847 * get_line failed to get a password (for example
2848 * because one was supplied on the command line
2849 * which has already failed to work). Terminate.
2851 send_packet(ssh, SSH1_MSG_DISCONNECT,
2852 PKT_STR, "No more passwords available to try",
2854 logevent("Unable to authenticate");
2855 connection_fatal(ssh->frontend, "Unable to authenticate");
2856 ssh_closing((Plug)ssh, NULL, 0, 0);
2860 /* Prompt may have come from server. We've munged it a bit, so
2861 * we know it to be zero-terminated at least once. */
2862 int ret; /* need not be saved over crReturn */
2863 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2866 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2868 crWaitUntil(!ispkt);
2869 ret = process_userpass_input(ssh, in, inlen);
2873 c_write_str(ssh, "\r\n");
2877 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2879 * Try public key authentication with the specified
2882 s->tried_publickey = 1;
2885 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2887 c_write_str(ssh, "Couldn't load private key from ");
2888 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2889 c_write_str(ssh, ".\r\n");
2890 continue; /* go and try password */
2893 c_write_str(ssh, "Wrong passphrase.\r\n");
2894 s->tried_publickey = 0;
2895 continue; /* try again */
2900 * Send a public key attempt.
2902 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2903 PKT_BIGNUM, s->key.modulus, PKT_END);
2906 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2907 c_write_str(ssh, "Server refused our public key.\r\n");
2908 continue; /* go and try password */
2910 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2911 bombout(("Bizarre response to offer of public key"));
2917 unsigned char buffer[32];
2918 Bignum challenge, response;
2920 ssh1_read_bignum(ssh->pktin.body, &challenge);
2921 response = rsadecrypt(challenge, &s->key);
2922 freebn(s->key.private_exponent);/* burn the evidence */
2924 for (i = 0; i < 32; i++) {
2925 buffer[i] = bignum_byte(response, 31 - i);
2929 MD5Update(&md5c, buffer, 32);
2930 MD5Update(&md5c, s->session_id, 16);
2931 MD5Final(buffer, &md5c);
2933 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2934 PKT_DATA, buffer, 16, PKT_END);
2941 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2942 if (flags & FLAG_VERBOSE)
2943 c_write_str(ssh, "Failed to authenticate with"
2944 " our public key.\r\n");
2945 continue; /* go and try password */
2946 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2947 bombout(("Bizarre response to RSA authentication response"));
2951 break; /* we're through! */
2953 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2955 * Defence against traffic analysis: we send a
2956 * whole bunch of packets containing strings of
2957 * different lengths. One of these strings is the
2958 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2959 * The others are all random data in
2960 * SSH1_MSG_IGNORE packets. This way a passive
2961 * listener can't tell which is the password, and
2962 * hence can't deduce the password length.
2964 * Anybody with a password length greater than 16
2965 * bytes is going to have enough entropy in their
2966 * password that a listener won't find it _that_
2967 * much help to know how long it is. So what we'll
2970 * - if password length < 16, we send 15 packets
2971 * containing string lengths 1 through 15
2973 * - otherwise, we let N be the nearest multiple
2974 * of 8 below the password length, and send 8
2975 * packets containing string lengths N through
2976 * N+7. This won't obscure the order of
2977 * magnitude of the password length, but it will
2978 * introduce a bit of extra uncertainty.
2980 * A few servers (the old 1.2.18 through 1.2.22)
2981 * can't deal with SSH1_MSG_IGNORE. For these
2982 * servers, we need an alternative defence. We make
2983 * use of the fact that the password is interpreted
2984 * as a C string: so we can append a NUL, then some
2987 * One server (a Cisco one) can deal with neither
2988 * SSH1_MSG_IGNORE _nor_ a padded password string.
2989 * For this server we are left with no defences
2990 * against password length sniffing.
2992 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2994 * The server can deal with SSH1_MSG_IGNORE, so
2995 * we can use the primary defence.
2997 int bottom, top, pwlen, i;
3000 pwlen = strlen(s->password);
3002 bottom = 0; /* zero length passwords are OK! :-) */
3005 bottom = pwlen & ~7;
3009 assert(pwlen >= bottom && pwlen <= top);
3011 randomstr = snewn(top + 1, char);
3013 for (i = bottom; i <= top; i++) {
3015 defer_packet(ssh, s->pwpkt_type,
3016 PKT_STR, s->password, PKT_END);
3018 for (j = 0; j < i; j++) {
3020 randomstr[j] = random_byte();
3021 } while (randomstr[j] == '\0');
3023 randomstr[i] = '\0';
3024 defer_packet(ssh, SSH1_MSG_IGNORE,
3025 PKT_STR, randomstr, PKT_END);
3028 logevent("Sending password with camouflage packets");
3029 ssh_pkt_defersend(ssh);
3031 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3033 * The server can't deal with SSH1_MSG_IGNORE
3034 * but can deal with padded passwords, so we
3035 * can use the secondary defence.
3041 len = strlen(s->password);
3042 if (len < sizeof(string)) {
3044 strcpy(string, s->password);
3045 len++; /* cover the zero byte */
3046 while (len < sizeof(string)) {
3047 string[len++] = (char) random_byte();
3052 logevent("Sending length-padded password");
3053 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3054 PKT_DATA, ss, len, PKT_END);
3057 * The server has _both_
3058 * BUG_CHOKES_ON_SSH1_IGNORE and
3059 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3060 * therefore nothing we can do.
3063 len = strlen(s->password);
3064 logevent("Sending unpadded password");
3065 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3066 PKT_DATA, s->password, len, PKT_END);
3069 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
3072 logevent("Sent password");
3073 memset(s->password, 0, strlen(s->password));
3075 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3076 if (flags & FLAG_VERBOSE)
3077 c_write_str(ssh, "Access denied\r\n");
3078 logevent("Authentication refused");
3079 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3080 bombout(("Strange packet received, type %d", ssh->pktin.type));
3085 logevent("Authentication successful");
3090 void sshfwd_close(struct ssh_channel *c)
3094 if (ssh->state != SSH_STATE_SESSION) {
3095 assert(ssh->state == SSH_STATE_CLOSED);
3099 if (c && !c->closes) {
3101 * If the channel's remoteid is -1, we have sent
3102 * CHANNEL_OPEN for this channel, but it hasn't even been
3103 * acknowledged by the server. So we must set a close flag
3104 * on it now, and then when the server acks the channel
3105 * open, we can close it then.
3107 if (((int)c->remoteid) != -1) {
3108 if (ssh->version == 1) {
3109 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3112 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3113 ssh2_pkt_adduint32(ssh, c->remoteid);
3117 c->closes = 1; /* sent MSG_CLOSE */
3118 if (c->type == CHAN_X11) {
3120 logevent("Forwarded X11 connection terminated");
3121 } else if (c->type == CHAN_SOCKDATA ||
3122 c->type == CHAN_SOCKDATA_DORMANT) {
3124 logevent("Forwarded port closed");
3129 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3133 if (ssh->state != SSH_STATE_SESSION) {
3134 assert(ssh->state == SSH_STATE_CLOSED);
3138 if (ssh->version == 1) {
3139 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3140 PKT_INT, c->remoteid,
3141 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3143 * In SSH1 we can return 0 here - implying that forwarded
3144 * connections are never individually throttled - because
3145 * the only circumstance that can cause throttling will be
3146 * the whole SSH connection backing up, in which case
3147 * _everything_ will be throttled as a whole.
3151 ssh2_add_channel_data(c, buf, len);
3152 return ssh2_try_send(c);
3156 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3160 if (ssh->state != SSH_STATE_SESSION) {
3161 assert(ssh->state == SSH_STATE_CLOSED);
3165 if (ssh->version == 1) {
3166 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3167 c->v.v1.throttling = 0;
3168 ssh1_throttle(ssh, -1);
3171 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3175 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3177 crBegin(ssh->ssh1_protocol_crstate);
3181 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3184 if (ssh->state == SSH_STATE_CLOSED)
3187 if (ssh->cfg.agentfwd && agent_exists()) {
3188 logevent("Requesting agent forwarding");
3189 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3193 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3194 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3195 bombout(("Protocol confusion"));
3197 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3198 logevent("Agent forwarding refused");
3200 logevent("Agent forwarding enabled");
3201 ssh->agentfwd_enabled = TRUE;
3205 if (ssh->cfg.x11_forward) {
3206 char proto[20], data[64];
3207 logevent("Requesting X11 forwarding");
3208 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3209 data, sizeof(data), ssh->cfg.x11_auth);
3210 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3211 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3212 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3213 PKT_STR, proto, PKT_STR, data,
3214 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3217 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3218 PKT_STR, proto, PKT_STR, data, PKT_END);
3223 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3224 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3225 bombout(("Protocol confusion"));
3227 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3228 logevent("X11 forwarding refused");
3230 logevent("X11 forwarding enabled");
3231 ssh->X11_fwd_enabled = TRUE;
3238 int sport,dport,sserv,dserv;
3239 char sports[256], dports[256], saddr[256], host[256];
3241 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3242 /* Add port forwardings. */
3243 ssh->portfwd_strptr = ssh->cfg.portfwd;
3244 while (*ssh->portfwd_strptr) {
3245 type = *ssh->portfwd_strptr++;
3248 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3249 if (*ssh->portfwd_strptr == ':') {
3251 * We've seen a colon in the middle of the
3252 * source port number. This means that
3253 * everything we've seen until now is the
3254 * source _address_, so we'll move it into
3255 * saddr and start sports from the beginning
3258 ssh->portfwd_strptr++;
3260 strcpy(saddr, sports);
3263 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3267 if (*ssh->portfwd_strptr == '\t')
3268 ssh->portfwd_strptr++;
3270 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3271 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3274 if (*ssh->portfwd_strptr == ':')
3275 ssh->portfwd_strptr++;
3277 while (*ssh->portfwd_strptr) {
3278 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3281 ssh->portfwd_strptr++;
3282 dport = atoi(dports);
3286 dport = net_service_lookup(dports);
3288 logeventf(ssh, "Service lookup failed for"
3289 " destination port \"%s\"", dports);
3293 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3296 sport = atoi(sports);
3300 sport = net_service_lookup(sports);
3302 logeventf(ssh, "Service lookup failed for source"
3303 " port \"%s\"", sports);
3306 if (sport && dport) {
3308 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3309 sport, ssh, &ssh->cfg);
3310 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3311 " forwarding to %s:%.*s%.*s%d%.*s",
3312 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3313 (int)(*saddr?1:0), ":",
3314 (int)(sserv ? strlen(sports) : 0), sports,
3315 sserv, "(", sport, sserv, ")",
3317 (int)(dserv ? strlen(dports) : 0), dports,
3318 dserv, "(", dport, dserv, ")");
3319 } else if (type == 'D') {
3320 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3321 sport, ssh, &ssh->cfg);
3322 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3323 " doing SOCKS dynamic forwarding",
3324 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3325 (int)(*saddr?1:0), ":",
3326 (int)(sserv ? strlen(sports) : 0), sports,
3327 sserv, "(", sport, sserv, ")");
3329 struct ssh_rportfwd *pf;
3330 pf = snew(struct ssh_rportfwd);
3331 strcpy(pf->dhost, host);
3335 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3338 if (add234(ssh->rportfwds, pf) != pf) {
3340 "Duplicate remote port forwarding to %s:%d",
3344 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3345 " forward to %s:%.*s%.*s%d%.*s",
3346 (int)(sserv ? strlen(sports) : 0), sports,
3347 sserv, "(", sport, sserv, ")",
3349 (int)(dserv ? strlen(dports) : 0), dports,
3350 dserv, "(", dport, dserv, ")");
3351 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3359 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3360 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3361 bombout(("Protocol confusion"));
3363 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3364 c_write_str(ssh, "Server refused port"
3367 logevent("Remote port forwarding enabled");
3374 if (!ssh->cfg.nopty) {
3375 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3376 PKT_STR, ssh->cfg.termtype,
3377 PKT_INT, ssh->term_height,
3378 PKT_INT, ssh->term_width,
3379 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3380 ssh->state = SSH_STATE_INTERMED;
3384 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3385 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3386 bombout(("Protocol confusion"));
3388 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3389 c_write_str(ssh, "Server refused to allocate pty\r\n");
3390 ssh->editing = ssh->echoing = 1;
3392 logevent("Allocated pty");
3394 ssh->editing = ssh->echoing = 1;
3397 if (ssh->cfg.compression) {
3398 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3402 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3403 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3404 bombout(("Protocol confusion"));
3406 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3407 c_write_str(ssh, "Server refused to compress\r\n");
3409 logevent("Started compression");
3410 ssh->v1_compressing = TRUE;
3411 ssh->cs_comp_ctx = zlib_compress_init();
3412 logevent("Initialised zlib (RFC1950) compression");
3413 ssh->sc_comp_ctx = zlib_decompress_init();
3414 logevent("Initialised zlib (RFC1950) decompression");
3418 * Start the shell or command.
3420 * Special case: if the first-choice command is an SSH2
3421 * subsystem (hence not usable here) and the second choice
3422 * exists, we fall straight back to that.
3425 char *cmd = ssh->cfg.remote_cmd_ptr;
3427 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3428 cmd = ssh->cfg.remote_cmd_ptr2;
3429 ssh->fallback_cmd = TRUE;
3432 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3434 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3435 logevent("Started session");
3438 ssh->state = SSH_STATE_SESSION;
3439 if (ssh->size_needed)
3440 ssh_size(ssh, ssh->term_width, ssh->term_height);
3441 if (ssh->eof_needed)
3442 ssh_special(ssh, TS_EOF);
3445 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3447 ssh->channels = newtree234(ssh_channelcmp);
3451 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3452 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3453 long len = GET_32BIT(ssh->pktin.body);
3455 from_backend(ssh->frontend,
3456 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3457 (char *)(ssh->pktin.body) + 4, len);
3458 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3459 ssh->v1_stdout_throttling = 1;
3460 ssh1_throttle(ssh, +1);
3462 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3463 ssh_closing((Plug)ssh, NULL, 0, 0);
3464 logevent("Received disconnect request");
3466 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3467 /* Remote side is trying to open a channel to talk to our
3468 * X-Server. Give them back a local channel number. */
3469 struct ssh_channel *c;
3471 logevent("Received X11 connect request");
3472 /* Refuse if X11 forwarding is disabled. */
3473 if (!ssh->X11_fwd_enabled) {
3474 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3475 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3476 logevent("Rejected X11 connect request");
3478 c = snew(struct ssh_channel);
3481 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3482 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3483 logevent("opening X11 forward connection failed");
3485 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3486 PKT_INT, GET_32BIT(ssh->pktin.body),
3490 ("opening X11 forward connection succeeded");
3491 c->remoteid = GET_32BIT(ssh->pktin.body);
3492 c->localid = alloc_channel_id(ssh);
3494 c->v.v1.throttling = 0;
3495 c->type = CHAN_X11; /* identify channel type */
3496 add234(ssh->channels, c);
3497 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3498 PKT_INT, c->remoteid, PKT_INT,
3499 c->localid, PKT_END);
3500 logevent("Opened X11 forward channel");
3503 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3504 /* Remote side is trying to open a channel to talk to our
3505 * agent. Give them back a local channel number. */
3506 struct ssh_channel *c;
3508 /* Refuse if agent forwarding is disabled. */
3509 if (!ssh->agentfwd_enabled) {
3510 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3511 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3513 c = snew(struct ssh_channel);
3515 c->remoteid = GET_32BIT(ssh->pktin.body);
3516 c->localid = alloc_channel_id(ssh);
3518 c->v.v1.throttling = 0;
3519 c->type = CHAN_AGENT; /* identify channel type */
3520 c->u.a.lensofar = 0;
3521 add234(ssh->channels, c);
3522 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3523 PKT_INT, c->remoteid, PKT_INT, c->localid,
3526 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3527 /* Remote side is trying to open a channel to talk to a
3528 * forwarded port. Give them back a local channel number. */
3529 struct ssh_channel *c;
3530 struct ssh_rportfwd pf;
3532 char host[256], buf[1024];
3535 c = snew(struct ssh_channel);
3538 hostsize = GET_32BIT(ssh->pktin.body+4);
3539 for (h = host, p = (char *)(ssh->pktin.body+8);
3540 hostsize != 0; hostsize--) {
3541 if (h+1 < host+sizeof(host))
3546 port = GET_32BIT(p);
3548 strcpy(pf.dhost, host);
3551 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3552 sprintf(buf, "Rejected remote port open request for %s:%d",
3555 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3556 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3558 sprintf(buf, "Received remote port open request for %s:%d",
3561 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3564 sprintf(buf, "Port open failed: %s", e);
3567 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3568 PKT_INT, GET_32BIT(ssh->pktin.body),
3571 c->remoteid = GET_32BIT(ssh->pktin.body);
3572 c->localid = alloc_channel_id(ssh);
3574 c->v.v1.throttling = 0;
3575 c->type = CHAN_SOCKDATA; /* identify channel type */
3576 add234(ssh->channels, c);
3577 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3578 PKT_INT, c->remoteid, PKT_INT,
3579 c->localid, PKT_END);
3580 logevent("Forwarded port opened successfully");
3584 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3585 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3586 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3587 struct ssh_channel *c;
3589 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3590 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3591 c->remoteid = localid;
3592 c->type = CHAN_SOCKDATA;
3593 c->v.v1.throttling = 0;
3594 pfd_confirm(c->u.pfd.s);
3597 if (c && c->closes) {
3599 * We have a pending close on this channel,
3600 * which we decided on before the server acked
3601 * the channel open. So now we know the
3602 * remoteid, we can close it again.
3604 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3605 PKT_INT, c->remoteid, PKT_END);
3608 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3609 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3610 struct ssh_channel *c;
3612 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3613 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3614 logevent("Forwarded connection refused by server");
3615 pfd_close(c->u.pfd.s);
3616 del234(ssh->channels, c);
3620 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3621 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3622 /* Remote side closes a channel. */
3623 unsigned i = GET_32BIT(ssh->pktin.body);
3624 struct ssh_channel *c;
3625 c = find234(ssh->channels, &i, ssh_channelfind);
3626 if (c && ((int)c->remoteid) != -1) {
3629 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3631 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3632 logevent("Forwarded X11 connection terminated");
3633 assert(c->u.x11.s != NULL);
3634 x11_close(c->u.x11.s);
3637 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3638 logevent("Forwarded port closed");
3639 assert(c->u.pfd.s != NULL);
3640 pfd_close(c->u.pfd.s);
3644 c->closes |= (closetype << 2); /* seen this message */
3645 if (!(c->closes & closetype)) {
3646 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3648 c->closes |= closetype; /* sent it too */
3651 if (c->closes == 15) {
3652 del234(ssh->channels, c);
3656 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3657 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3658 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3662 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3663 /* Data sent down one of our channels. */
3664 int i = GET_32BIT(ssh->pktin.body);
3665 int len = GET_32BIT(ssh->pktin.body + 4);
3666 unsigned char *p = ssh->pktin.body + 8;
3667 struct ssh_channel *c;
3668 c = find234(ssh->channels, &i, ssh_channelfind);
3673 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3676 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3679 /* Data for an agent message. Buffer it. */
3681 if (c->u.a.lensofar < 4) {
3682 int l = min(4 - c->u.a.lensofar, len);
3683 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3687 c->u.a.lensofar += l;
3689 if (c->u.a.lensofar == 4) {
3691 4 + GET_32BIT(c->u.a.msglen);
3692 c->u.a.message = snewn(c->u.a.totallen,
3694 memcpy(c->u.a.message, c->u.a.msglen, 4);
3696 if (c->u.a.lensofar >= 4 && len > 0) {
3698 min(c->u.a.totallen - c->u.a.lensofar,
3700 memcpy(c->u.a.message + c->u.a.lensofar, p,
3704 c->u.a.lensofar += l;
3706 if (c->u.a.lensofar == c->u.a.totallen) {
3709 if (agent_query(c->u.a.message,
3712 ssh_agentf_callback, c))
3713 ssh_agentf_callback(c, reply, replylen);
3714 sfree(c->u.a.message);
3715 c->u.a.lensofar = 0;
3718 bufsize = 0; /* agent channels never back up */
3721 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3722 c->v.v1.throttling = 1;
3723 ssh1_throttle(ssh, +1);
3726 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3727 /* may be from EXEC_SHELL on some servers */
3728 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3729 /* may be from EXEC_SHELL on some servers
3730 * if no pty is available or in other odd cases. Ignore */
3731 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3733 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3734 sprintf(buf, "Server sent command exit status %d",
3737 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3739 * In case `helpful' firewalls or proxies tack
3740 * extra human-readable text on the end of the
3741 * session which we might mistake for another
3742 * encrypted packet, we close the session once
3743 * we've sent EXIT_CONFIRMATION.
3745 ssh_closing((Plug)ssh, NULL, 0, 0);
3748 bombout(("Strange packet received: type %d", ssh->pktin.type));
3753 int len = min(inlen, 512);
3754 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3755 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3766 * Utility routine for decoding comma-separated strings in KEXINIT.
3768 static int in_commasep_string(char *needle, char *haystack, int haylen)
3771 if (!needle || !haystack) /* protect against null pointers */
3773 needlen = strlen(needle);
3776 * Is it at the start of the string?
3778 if (haylen >= needlen && /* haystack is long enough */
3779 !memcmp(needle, haystack, needlen) && /* initial match */
3780 (haylen == needlen || haystack[needlen] == ',')
3781 /* either , or EOS follows */
3785 * If not, search for the next comma and resume after that.
3786 * If no comma found, terminate.
3788 while (haylen > 0 && *haystack != ',')
3789 haylen--, haystack++;
3792 haylen--, haystack++; /* skip over comma itself */
3797 * SSH2 key creation method.
3799 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3800 unsigned char *sessid, char chr,
3801 unsigned char *keyspace)
3804 /* First 20 bytes. */
3806 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3808 SHA_Bytes(&s, H, 20);
3809 SHA_Bytes(&s, &chr, 1);
3810 SHA_Bytes(&s, sessid, 20);
3811 SHA_Final(&s, keyspace);
3812 /* Next 20 bytes. */
3814 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3816 SHA_Bytes(&s, H, 20);
3817 SHA_Bytes(&s, keyspace, 20);
3818 SHA_Final(&s, keyspace + 20);
3822 * Handle the SSH2 transport layer.
3824 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3826 struct do_ssh2_transport_state {
3827 int nbits, pbits, warn;
3828 Bignum p, g, e, f, K;
3829 int kex_init_value, kex_reply_value;
3830 const struct ssh_mac **maclist;
3832 const struct ssh2_cipher *cscipher_tobe;
3833 const struct ssh2_cipher *sccipher_tobe;
3834 const struct ssh_mac *csmac_tobe;
3835 const struct ssh_mac *scmac_tobe;
3836 const struct ssh_compress *cscomp_tobe;
3837 const struct ssh_compress *sccomp_tobe;
3838 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3839 int hostkeylen, siglen;
3840 void *hkey; /* actual host key */
3841 unsigned char exchange_hash[20];
3842 int n_preferred_ciphers;
3843 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3844 const struct ssh_compress *preferred_comp;
3847 crState(do_ssh2_transport_state);
3849 crBegin(ssh->do_ssh2_transport_crstate);
3851 s->cscipher_tobe = s->sccipher_tobe = NULL;
3852 s->csmac_tobe = s->scmac_tobe = NULL;
3853 s->cscomp_tobe = s->sccomp_tobe = NULL;
3861 * Set up the preferred ciphers. (NULL => warn below here)
3863 s->n_preferred_ciphers = 0;
3864 for (i = 0; i < CIPHER_MAX; i++) {
3865 switch (ssh->cfg.ssh_cipherlist[i]) {
3866 case CIPHER_BLOWFISH:
3867 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3870 if (ssh->cfg.ssh2_des_cbc) {
3871 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3875 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3878 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3881 /* Flag for later. Don't bother if it's the last in
3883 if (i < CIPHER_MAX - 1) {
3884 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3892 * Set up preferred compression.
3894 if (ssh->cfg.compression)
3895 s->preferred_comp = &ssh_zlib;
3897 s->preferred_comp = &ssh_comp_none;
3900 * Be prepared to work around the buggy MAC problem.
3902 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3903 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3905 s->maclist = macs, s->nmacs = lenof(macs);
3909 int i, j, cipherstr_started;
3912 * Construct and send our key exchange packet.
3914 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3915 for (i = 0; i < 16; i++)
3916 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3917 /* List key exchange algorithms. */
3918 ssh2_pkt_addstring_start(ssh);
3919 for (i = 0; i < lenof(kex_algs); i++) {
3920 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3921 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3923 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3924 if (i < lenof(kex_algs) - 1)
3925 ssh2_pkt_addstring_str(ssh, ",");
3927 /* List server host key algorithms. */
3928 ssh2_pkt_addstring_start(ssh);
3929 for (i = 0; i < lenof(hostkey_algs); i++) {
3930 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3931 if (i < lenof(hostkey_algs) - 1)
3932 ssh2_pkt_addstring_str(ssh, ",");
3934 /* List client->server encryption algorithms. */
3935 ssh2_pkt_addstring_start(ssh);
3936 cipherstr_started = 0;
3937 for (i = 0; i < s->n_preferred_ciphers; i++) {
3938 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3939 if (!c) continue; /* warning flag */
3940 for (j = 0; j < c->nciphers; j++) {
3941 if (cipherstr_started)
3942 ssh2_pkt_addstring_str(ssh, ",");
3943 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3944 cipherstr_started = 1;
3947 /* List server->client encryption algorithms. */
3948 ssh2_pkt_addstring_start(ssh);
3949 cipherstr_started = 0;
3950 for (i = 0; i < s->n_preferred_ciphers; i++) {
3951 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3952 if (!c) continue; /* warning flag */
3953 for (j = 0; j < c->nciphers; j++) {
3954 if (cipherstr_started)
3955 ssh2_pkt_addstring_str(ssh, ",");
3956 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3957 cipherstr_started = 1;
3960 /* List client->server MAC algorithms. */
3961 ssh2_pkt_addstring_start(ssh);
3962 for (i = 0; i < s->nmacs; i++) {
3963 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3964 if (i < s->nmacs - 1)
3965 ssh2_pkt_addstring_str(ssh, ",");
3967 /* List server->client MAC algorithms. */
3968 ssh2_pkt_addstring_start(ssh);
3969 for (i = 0; i < s->nmacs; i++) {
3970 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3971 if (i < s->nmacs - 1)
3972 ssh2_pkt_addstring_str(ssh, ",");
3974 /* List client->server compression algorithms. */
3975 ssh2_pkt_addstring_start(ssh);
3976 for (i = 0; i < lenof(compressions) + 1; i++) {
3977 const struct ssh_compress *c =
3978 i == 0 ? s->preferred_comp : compressions[i - 1];
3979 ssh2_pkt_addstring_str(ssh, c->name);
3980 if (i < lenof(compressions))
3981 ssh2_pkt_addstring_str(ssh, ",");
3983 /* List server->client compression algorithms. */
3984 ssh2_pkt_addstring_start(ssh);
3985 for (i = 0; i < lenof(compressions) + 1; i++) {
3986 const struct ssh_compress *c =
3987 i == 0 ? s->preferred_comp : compressions[i - 1];
3988 ssh2_pkt_addstring_str(ssh, c->name);
3989 if (i < lenof(compressions))
3990 ssh2_pkt_addstring_str(ssh, ",");
3992 /* List client->server languages. Empty list. */
3993 ssh2_pkt_addstring_start(ssh);
3994 /* List server->client languages. Empty list. */
3995 ssh2_pkt_addstring_start(ssh);
3996 /* First KEX packet does _not_ follow, because we're not that brave. */
3997 ssh2_pkt_addbool(ssh, FALSE);
3999 ssh2_pkt_adduint32(ssh, 0);
4002 ssh->exhash = ssh->exhashbase;
4003 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4009 if (ssh->pktin.length > 5)
4010 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4013 * Now examine the other side's KEXINIT to see what we're up
4020 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4021 bombout(("expected key exchange packet from server"));
4025 ssh->hostkey = NULL;
4026 s->cscipher_tobe = NULL;
4027 s->sccipher_tobe = NULL;
4028 s->csmac_tobe = NULL;
4029 s->scmac_tobe = NULL;
4030 s->cscomp_tobe = NULL;
4031 s->sccomp_tobe = NULL;
4032 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4033 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4034 for (i = 0; i < lenof(kex_algs); i++) {
4035 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4036 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4038 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4039 ssh->kex = kex_algs[i];
4043 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4044 for (i = 0; i < lenof(hostkey_algs); i++) {
4045 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4046 ssh->hostkey = hostkey_algs[i];
4050 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4052 for (i = 0; i < s->n_preferred_ciphers; i++) {
4053 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4057 for (j = 0; j < c->nciphers; j++) {
4058 if (in_commasep_string(c->list[j]->name, str, len)) {
4059 s->cscipher_tobe = c->list[j];
4064 if (s->cscipher_tobe) {
4066 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4070 if (!s->cscipher_tobe) {
4071 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4072 str ? str : "(null)"));
4076 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4078 for (i = 0; i < s->n_preferred_ciphers; i++) {
4079 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4083 for (j = 0; j < c->nciphers; j++) {
4084 if (in_commasep_string(c->list[j]->name, str, len)) {
4085 s->sccipher_tobe = c->list[j];
4090 if (s->sccipher_tobe) {
4092 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4096 if (!s->sccipher_tobe) {
4097 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4098 str ? str : "(null)"));
4102 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4103 for (i = 0; i < s->nmacs; i++) {
4104 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4105 s->csmac_tobe = s->maclist[i];
4109 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4110 for (i = 0; i < s->nmacs; i++) {
4111 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4112 s->scmac_tobe = s->maclist[i];
4116 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4117 for (i = 0; i < lenof(compressions) + 1; i++) {
4118 const struct ssh_compress *c =
4119 i == 0 ? s->preferred_comp : compressions[i - 1];
4120 if (in_commasep_string(c->name, str, len)) {
4125 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4126 for (i = 0; i < lenof(compressions) + 1; i++) {
4127 const struct ssh_compress *c =
4128 i == 0 ? s->preferred_comp : compressions[i - 1];
4129 if (in_commasep_string(c->name, str, len)) {
4137 * Work out the number of bits of key we will need from the key
4138 * exchange. We start with the maximum key length of either
4144 csbits = s->cscipher_tobe->keylen;
4145 scbits = s->sccipher_tobe->keylen;
4146 s->nbits = (csbits > scbits ? csbits : scbits);
4148 /* The keys only have 160-bit entropy, since they're based on
4149 * a SHA-1 hash. So cap the key size at 160 bits. */
4154 * If we're doing Diffie-Hellman group exchange, start by
4155 * requesting a group.
4157 if (ssh->kex == &ssh_diffiehellman_gex) {
4158 logevent("Doing Diffie-Hellman group exchange");
4159 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4161 * Work out how big a DH group we will need to allow that
4164 s->pbits = 512 << ((s->nbits - 1) / 64);
4165 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4166 ssh2_pkt_adduint32(ssh, s->pbits);
4170 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4171 bombout(("expected key exchange group packet from server"));
4174 s->p = ssh2_pkt_getmp(ssh);
4175 s->g = ssh2_pkt_getmp(ssh);
4176 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4177 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4178 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4180 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4181 ssh->kex_ctx = dh_setup_group1();
4182 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4183 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4186 logevent("Doing Diffie-Hellman key exchange");
4188 * Now generate and send e for Diffie-Hellman.
4190 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4191 ssh2_pkt_init(ssh, s->kex_init_value);
4192 ssh2_pkt_addmp(ssh, s->e);
4196 if (ssh->pktin.type != s->kex_reply_value) {
4197 bombout(("expected key exchange reply packet from server"));
4200 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4201 s->f = ssh2_pkt_getmp(ssh);
4202 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4204 s->K = dh_find_K(ssh->kex_ctx, s->f);
4206 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4207 if (ssh->kex == &ssh_diffiehellman_gex) {
4208 sha_uint32(&ssh->exhash, s->pbits);
4209 sha_mpint(&ssh->exhash, s->p);
4210 sha_mpint(&ssh->exhash, s->g);
4212 sha_mpint(&ssh->exhash, s->e);
4213 sha_mpint(&ssh->exhash, s->f);
4214 sha_mpint(&ssh->exhash, s->K);
4215 SHA_Final(&ssh->exhash, s->exchange_hash);
4217 dh_cleanup(ssh->kex_ctx);
4218 ssh->kex_ctx = NULL;
4221 debug(("Exchange hash is:\n"));
4222 dmemdump(s->exchange_hash, 20);
4225 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4227 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4228 (char *)s->exchange_hash, 20)) {
4229 bombout(("Server's host key did not match the signature supplied"));
4234 * Authenticate remote host: verify host key. (We've already
4235 * checked the signature of the exchange hash.)
4237 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4238 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4239 verify_ssh_host_key(ssh->frontend,
4240 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4241 s->keystr, s->fingerprint);
4242 if (s->first_kex) { /* don't bother logging this in rekeys */
4243 logevent("Host key fingerprint is:");
4244 logevent(s->fingerprint);
4246 sfree(s->fingerprint);
4248 ssh->hostkey->freekey(s->hkey);
4251 * Send SSH2_MSG_NEWKEYS.
4253 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4257 * Expect SSH2_MSG_NEWKEYS from server.
4260 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4261 bombout(("expected new-keys packet from server"));
4266 * Create and initialise session keys.
4268 if (ssh->cs_cipher_ctx)
4269 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4270 ssh->cscipher = s->cscipher_tobe;
4271 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4273 if (ssh->sc_cipher_ctx)
4274 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4275 ssh->sccipher = s->sccipher_tobe;
4276 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4278 if (ssh->cs_mac_ctx)
4279 ssh->csmac->free_context(ssh->cs_mac_ctx);
4280 ssh->csmac = s->csmac_tobe;
4281 ssh->cs_mac_ctx = ssh->csmac->make_context();
4283 if (ssh->sc_mac_ctx)
4284 ssh->scmac->free_context(ssh->sc_mac_ctx);
4285 ssh->scmac = s->scmac_tobe;
4286 ssh->sc_mac_ctx = ssh->scmac->make_context();
4288 if (ssh->cs_comp_ctx)
4289 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4290 ssh->cscomp = s->cscomp_tobe;
4291 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4293 if (ssh->sc_comp_ctx)
4294 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4295 ssh->sccomp = s->sccomp_tobe;
4296 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4299 * Set IVs after keys. Here we use the exchange hash from the
4300 * _first_ key exchange.
4303 unsigned char keyspace[40];
4305 memcpy(ssh->v2_session_id, s->exchange_hash,
4306 sizeof(s->exchange_hash));
4307 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4308 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4309 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4310 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4311 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4312 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4313 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4314 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4315 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4316 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4317 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4318 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4320 logeventf(ssh, "Initialised %.200s client->server encryption",
4321 ssh->cscipher->text_name);
4322 logeventf(ssh, "Initialised %.200s server->client encryption",
4323 ssh->sccipher->text_name);
4324 if (ssh->cscomp->text_name)
4325 logeventf(ssh, "Initialised %s compression",
4326 ssh->cscomp->text_name);
4327 if (ssh->sccomp->text_name)
4328 logeventf(ssh, "Initialised %s decompression",
4329 ssh->sccomp->text_name);
4332 * If this is the first key exchange phase, we must pass the
4333 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4334 * wants to see it but because it will need time to initialise
4335 * itself before it sees an actual packet. In subsequent key
4336 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4337 * it would only confuse the layer above.
4339 if (!s->first_kex) {
4345 * Now we're encrypting. Begin returning 1 to the protocol main
4346 * function so that other things can run on top of the
4347 * transport. If we ever see a KEXINIT, we must go back to the
4350 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4353 logevent("Server initiated key re-exchange");
4354 goto begin_key_exchange;
4360 * Add data to an SSH2 channel output buffer.
4362 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4365 bufchain_add(&c->v.v2.outbuffer, buf, len);
4369 * Attempt to send data on an SSH2 channel.
4371 static int ssh2_try_send(struct ssh_channel *c)
4375 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4378 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4379 if ((unsigned)len > c->v.v2.remwindow)
4380 len = c->v.v2.remwindow;
4381 if ((unsigned)len > c->v.v2.remmaxpkt)
4382 len = c->v.v2.remmaxpkt;
4383 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4384 ssh2_pkt_adduint32(ssh, c->remoteid);
4385 ssh2_pkt_addstring_start(ssh);
4386 ssh2_pkt_addstring_data(ssh, data, len);
4388 bufchain_consume(&c->v.v2.outbuffer, len);
4389 c->v.v2.remwindow -= len;
4393 * After having sent as much data as we can, return the amount
4396 return bufchain_size(&c->v.v2.outbuffer);
4400 * Potentially enlarge the window on an SSH2 channel.
4402 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4407 * Never send WINDOW_ADJUST for a channel that the remote side
4408 * already thinks it's closed; there's no point, since it won't
4409 * be sending any more data anyway.
4414 if (newwin > c->v.v2.locwindow) {
4415 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4416 ssh2_pkt_adduint32(ssh, c->remoteid);
4417 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4419 c->v.v2.locwindow = newwin;
4424 * Handle the SSH2 userauth and connection layers.
4426 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4428 struct do_ssh2_authconn_state {
4430 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4432 AUTH_KEYBOARD_INTERACTIVE
4436 AUTH_TYPE_PUBLICKEY,
4437 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4438 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4440 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4441 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4443 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4444 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4445 int kbd_inter_running;
4447 int num_prompts, curr_prompt, echo;
4452 void *publickey_blob;
4453 int publickey_bloblen;
4454 unsigned char request[5], *response, *p;
4458 char *pkblob, *alg, *commentp;
4459 int pklen, alglen, commentlen;
4460 int siglen, retlen, len;
4461 char *q, *agentreq, *ret;
4464 crState(do_ssh2_authconn_state);
4466 crBegin(ssh->do_ssh2_authconn_crstate);
4469 * Request userauth protocol, and await a response to it.
4471 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4472 ssh2_pkt_addstring(ssh, "ssh-userauth");
4474 crWaitUntilV(ispkt);
4475 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4476 bombout(("Server refused user authentication protocol"));
4481 * We repeat this whole loop, including the username prompt,
4482 * until we manage a successful authentication. If the user
4483 * types the wrong _password_, they can be sent back to the
4484 * beginning to try another username, if this is configured on.
4485 * (If they specify a username in the config, they are never
4486 * asked, even if they do give a wrong password.)
4488 * I think this best serves the needs of
4490 * - the people who have no configuration, no keys, and just
4491 * want to try repeated (username,password) pairs until they
4492 * type both correctly
4494 * - people who have keys and configuration but occasionally
4495 * need to fall back to passwords
4497 * - people with a key held in Pageant, who might not have
4498 * logged in to a particular machine before; so they want to
4499 * type a username, and then _either_ their key will be
4500 * accepted, _or_ they will type a password. If they mistype
4501 * the username they will want to be able to get back and
4504 s->username[0] = '\0';
4505 s->got_username = FALSE;
4510 if (s->got_username && !ssh->cfg.change_username) {
4512 * We got a username last time round this loop, and
4513 * with change_username turned off we don't try to get
4516 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4517 if (ssh_get_line && !ssh_getline_pw_only) {
4518 if (!ssh_get_line("login as: ",
4519 s->username, sizeof(s->username), FALSE)) {
4521 * get_line failed to get a username.
4524 logevent("No username provided. Abandoning session.");
4525 ssh_closing((Plug)ssh, NULL, 0, 0);
4529 int ret; /* need not be saved across crReturn */
4530 c_write_str(ssh, "login as: ");
4532 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4534 crWaitUntilV(!ispkt);
4535 ret = process_userpass_input(ssh, in, inlen);
4539 c_write_str(ssh, "\r\n");
4541 s->username[strcspn(s->username, "\n\r")] = '\0';
4544 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4545 s->username[sizeof(s->username)-1] = '\0';
4546 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4547 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4548 c_write_str(ssh, stuff);
4552 s->got_username = TRUE;
4555 * Send an authentication request using method "none": (a)
4556 * just in case it succeeds, and (b) so that we know what
4557 * authentication methods we can usefully try next.
4559 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4561 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4562 ssh2_pkt_addstring(ssh, s->username);
4563 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4564 ssh2_pkt_addstring(ssh, "none"); /* method */
4566 s->type = AUTH_TYPE_NONE;
4568 s->we_are_in = FALSE;
4570 s->tried_pubkey_config = FALSE;
4571 s->tried_agent = FALSE;
4572 s->tried_keyb_inter = FALSE;
4573 s->kbd_inter_running = FALSE;
4574 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4575 if (!filename_is_null(ssh->cfg.keyfile)) {
4577 logeventf(ssh, "Reading private key file \"%.150s\"",
4578 filename_to_str(&ssh->cfg.keyfile));
4579 keytype = key_type(&ssh->cfg.keyfile);
4580 if (keytype == SSH_KEYTYPE_SSH2) {
4582 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4583 &s->publickey_bloblen);
4586 logeventf(ssh, "Unable to use this key file (%s)",
4587 key_type_to_str(keytype));
4588 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4590 filename_to_str(&ssh->cfg.keyfile),
4591 key_type_to_str(keytype));
4592 c_write_str(ssh, msgbuf);
4594 s->publickey_blob = NULL;
4597 s->publickey_blob = NULL;
4601 * Wait for the result of the last authentication request.
4604 crWaitUntilV(ispkt);
4605 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4609 * Don't show the banner if we're operating in
4610 * non-verbose non-interactive mode. (It's probably
4611 * a script, which means nobody will read the
4612 * banner _anyway_, and moreover the printing of
4613 * the banner will screw up processing on the
4614 * output of (say) plink.)
4616 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4617 ssh2_pkt_getstring(ssh, &banner, &size);
4619 c_write_untrusted(ssh, banner, size);
4621 crWaitUntilV(ispkt);
4623 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4624 logevent("Access granted");
4625 s->we_are_in = TRUE;
4629 if (s->kbd_inter_running &&
4630 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4632 * This is either a further set-of-prompts packet
4633 * in keyboard-interactive authentication, or it's
4634 * the same one and we came back here with `gotit'
4635 * set. In the former case, we must reset the
4636 * curr_prompt variable.
4640 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4641 bombout(("Strange packet received during authentication: type %d",
4649 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4650 * we can look at the string in it and know what we can
4651 * helpfully try next.
4653 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4656 ssh2_pkt_getstring(ssh, &methods, &methlen);
4657 s->kbd_inter_running = FALSE;
4658 if (!ssh2_pkt_getbool(ssh)) {
4660 * We have received an unequivocal Access
4661 * Denied. This can translate to a variety of
4664 * - if we'd just tried "none" authentication,
4665 * it's not worth printing anything at all
4667 * - if we'd just tried a public key _offer_,
4668 * the message should be "Server refused our
4669 * key" (or no message at all if the key
4670 * came from Pageant)
4672 * - if we'd just tried anything else, the
4673 * message really should be "Access denied".
4675 * Additionally, if we'd just tried password
4676 * authentication, we should break out of this
4677 * whole loop so as to go back to the username
4680 if (s->type == AUTH_TYPE_NONE) {
4682 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4683 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4684 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4685 c_write_str(ssh, "Server refused our key\r\n");
4686 logevent("Server refused public key");
4687 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4688 /* server declined keyboard-interactive; ignore */
4690 c_write_str(ssh, "Access denied\r\n");
4691 logevent("Access denied");
4692 if (s->type == AUTH_TYPE_PASSWORD) {
4693 s->we_are_in = FALSE;
4698 c_write_str(ssh, "Further authentication required\r\n");
4699 logevent("Further authentication required");
4703 in_commasep_string("publickey", methods, methlen);
4705 in_commasep_string("password", methods, methlen);
4706 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4707 in_commasep_string("keyboard-interactive", methods, methlen);
4711 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4714 * Most password/passphrase prompts will be
4715 * non-echoing, so we set this to 0 by default.
4716 * Exception is that some keyboard-interactive prompts
4717 * can be echoing, in which case we'll set this to 1.
4721 if (!s->method && s->can_pubkey &&
4722 agent_exists() && !s->tried_agent) {
4724 * Attempt public-key authentication using Pageant.
4729 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4730 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4732 s->tried_agent = TRUE;
4734 logevent("Pageant is running. Requesting keys.");
4736 /* Request the keys held by the agent. */
4737 PUT_32BIT(s->request, 1);
4738 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4739 if (!agent_query(s->request, 5, &r, &s->responselen,
4740 ssh_agent_callback, ssh)) {
4744 bombout(("Unexpected data from server while"
4745 " waiting for agent response"));
4748 } while (ispkt || inlen > 0);
4749 r = ssh->agent_response;
4750 s->responselen = ssh->agent_response_len;
4752 s->response = (unsigned char *) r;
4753 if (s->response && s->responselen >= 5 &&
4754 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4755 s->p = s->response + 5;
4756 s->nkeys = GET_32BIT(s->p);
4760 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4763 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4768 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4771 s->pklen = GET_32BIT(s->p);
4773 if (s->publickey_blob &&
4774 s->pklen == s->publickey_bloblen &&
4775 !memcmp(s->p, s->publickey_blob,
4776 s->publickey_bloblen)) {
4777 logevent("This key matches configured key file");
4778 s->tried_pubkey_config = 1;
4780 s->pkblob = (char *)s->p;
4782 s->alglen = GET_32BIT(s->pkblob);
4783 s->alg = s->pkblob + 4;
4784 s->commentlen = GET_32BIT(s->p);
4786 s->commentp = (char *)s->p;
4787 s->p += s->commentlen;
4788 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4789 ssh2_pkt_addstring(ssh, s->username);
4790 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4791 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4792 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4793 ssh2_pkt_addstring_start(ssh);
4794 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4795 ssh2_pkt_addstring_start(ssh);
4796 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4799 crWaitUntilV(ispkt);
4800 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4801 logevent("Key refused");
4805 if (flags & FLAG_VERBOSE) {
4806 c_write_str(ssh, "Authenticating with "
4808 c_write(ssh, s->commentp, s->commentlen);
4809 c_write_str(ssh, "\" from agent\r\n");
4813 * Server is willing to accept the key.
4814 * Construct a SIGN_REQUEST.
4816 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4817 ssh2_pkt_addstring(ssh, s->username);
4818 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4819 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4820 ssh2_pkt_addbool(ssh, TRUE);
4821 ssh2_pkt_addstring_start(ssh);
4822 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4823 ssh2_pkt_addstring_start(ssh);
4824 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4826 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4827 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4829 s->len = 1; /* message type */
4830 s->len += 4 + s->pklen; /* key blob */
4831 s->len += 4 + s->siglen; /* data to sign */
4832 s->len += 4; /* flags */
4833 s->agentreq = snewn(4 + s->len, char);
4834 PUT_32BIT(s->agentreq, s->len);
4835 s->q = s->agentreq + 4;
4836 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4837 PUT_32BIT(s->q, s->pklen);
4839 memcpy(s->q, s->pkblob, s->pklen);
4841 PUT_32BIT(s->q, s->siglen);
4843 /* Now the data to be signed... */
4844 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4845 PUT_32BIT(s->q, 20);
4848 memcpy(s->q, ssh->v2_session_id, 20);
4850 memcpy(s->q, ssh->pktout.data + 5,
4851 ssh->pktout.length - 5);
4852 s->q += ssh->pktout.length - 5;
4853 /* And finally the (zero) flags word. */
4855 if (!agent_query(s->agentreq, s->len + 4,
4857 ssh_agent_callback, ssh)) {
4861 bombout(("Unexpected data from server"
4862 " while waiting for agent"
4866 } while (ispkt || inlen > 0);
4867 vret = ssh->agent_response;
4868 s->retlen = ssh->agent_response_len;
4873 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4874 logevent("Sending Pageant's response");
4875 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4877 GET_32BIT(s->ret + 5));
4883 ("Pageant failed to answer challenge");
4893 if (!s->method && s->can_pubkey && s->publickey_blob
4894 && !s->tried_pubkey_config) {
4895 unsigned char *pub_blob;
4896 char *algorithm, *comment;
4899 s->tried_pubkey_config = TRUE;
4901 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4902 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4905 * Try the public key supplied in the configuration.
4907 * First, offer the public blob to see if the server is
4908 * willing to accept it.
4911 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4915 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4916 ssh2_pkt_addstring(ssh, s->username);
4917 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4918 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4919 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4920 ssh2_pkt_addstring(ssh, algorithm);
4921 ssh2_pkt_addstring_start(ssh);
4922 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4925 logevent("Offered public key"); /* FIXME */
4927 crWaitUntilV(ispkt);
4928 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4930 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4931 continue; /* key refused; give up on it */
4934 logevent("Offer of public key accepted");
4936 * Actually attempt a serious authentication using
4939 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4940 sprintf(s->pwprompt,
4941 "Passphrase for key \"%.100s\": ",
4947 c_write_str(ssh, "Authenticating with public key \"");
4948 c_write_str(ssh, comment);
4949 c_write_str(ssh, "\"\r\n");
4950 s->method = AUTH_PUBLICKEY_FILE;
4954 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4955 s->method = AUTH_KEYBOARD_INTERACTIVE;
4956 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4957 s->tried_keyb_inter = TRUE;
4959 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4960 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4962 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4963 ssh2_pkt_addstring(ssh, s->username);
4964 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4965 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4966 ssh2_pkt_addstring(ssh, ""); /* lang */
4967 ssh2_pkt_addstring(ssh, "");
4970 crWaitUntilV(ispkt);
4971 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4972 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4974 logevent("Keyboard-interactive authentication refused");
4975 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4979 s->kbd_inter_running = TRUE;
4983 if (s->kbd_inter_running) {
4984 s->method = AUTH_KEYBOARD_INTERACTIVE;
4985 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4986 s->tried_keyb_inter = TRUE;
4988 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4989 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4991 if (s->curr_prompt == 0) {
4993 * We've got a fresh USERAUTH_INFO_REQUEST.
4994 * Display header data, and start going through
4997 char *name, *inst, *lang;
4998 int name_len, inst_len, lang_len;
5000 ssh2_pkt_getstring(ssh, &name, &name_len);
5001 ssh2_pkt_getstring(ssh, &inst, &inst_len);
5002 ssh2_pkt_getstring(ssh, &lang, &lang_len);
5004 c_write_untrusted(ssh, name, name_len);
5005 c_write_str(ssh, "\r\n");
5008 c_write_untrusted(ssh, inst, inst_len);
5009 c_write_str(ssh, "\r\n");
5011 s->num_prompts = ssh2_pkt_getuint32(ssh);
5015 * If there are prompts remaining in the packet,
5016 * display one and get a response.
5018 if (s->curr_prompt < s->num_prompts) {
5022 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
5023 if (prompt_len > 0) {
5024 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
5025 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
5026 prompt_len : sizeof(s->pwprompt)-1] = '\0';
5029 "<server failed to send prompt>: ");
5031 s->echo = ssh2_pkt_getbool(ssh);
5037 if (!s->method && s->can_passwd) {
5038 s->method = AUTH_PASSWORD;
5039 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5040 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5041 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5048 if (!ssh_get_line(s->pwprompt, s->password,
5049 sizeof(s->password), TRUE)) {
5051 * get_line failed to get a password (for
5052 * example because one was supplied on the
5053 * command line which has already failed to
5056 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5057 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5058 ssh2_pkt_addstring(ssh, "No more passwords available"
5060 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5062 logevent("Unable to authenticate");
5063 connection_fatal(ssh->frontend,
5064 "Unable to authenticate");
5065 ssh_closing((Plug)ssh, NULL, 0, 0);
5069 int ret; /* need not be saved across crReturn */
5070 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5073 setup_userpass_input(ssh, s->password,
5074 sizeof(s->password), s->echo);
5076 crWaitUntilV(!ispkt);
5077 ret = process_userpass_input(ssh, in, inlen);
5081 c_write_str(ssh, "\r\n");
5085 if (s->method == AUTH_PUBLICKEY_FILE) {
5087 * We have our passphrase. Now try the actual authentication.
5089 struct ssh2_userkey *key;
5091 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
5092 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5093 if (key == SSH2_WRONG_PASSPHRASE) {
5094 c_write_str(ssh, "Wrong passphrase\r\n");
5095 s->tried_pubkey_config = FALSE;
5097 c_write_str(ssh, "Unable to load private key\r\n");
5098 s->tried_pubkey_config = TRUE;
5100 /* Send a spurious AUTH_NONE to return to the top. */
5101 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5102 ssh2_pkt_addstring(ssh, s->username);
5103 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5104 ssh2_pkt_addstring(ssh, "none"); /* method */
5106 s->type = AUTH_TYPE_NONE;
5108 unsigned char *pkblob, *sigblob, *sigdata;
5109 int pkblob_len, sigblob_len, sigdata_len;
5113 * We have loaded the private key and the server
5114 * has announced that it's willing to accept it.
5115 * Hallelujah. Generate a signature and send it.
5117 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5118 ssh2_pkt_addstring(ssh, s->username);
5119 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5120 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5121 ssh2_pkt_addbool(ssh, TRUE);
5122 ssh2_pkt_addstring(ssh, key->alg->name);
5123 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5124 ssh2_pkt_addstring_start(ssh);
5125 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5128 * The data to be signed is:
5132 * followed by everything so far placed in the
5135 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5136 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5138 sigdata = snewn(sigdata_len, unsigned char);
5140 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5141 PUT_32BIT(sigdata+p, 20);
5144 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5145 memcpy(sigdata+p, ssh->pktout.data + 5,
5146 ssh->pktout.length - 5);
5147 p += ssh->pktout.length - 5;
5148 assert(p == sigdata_len);
5149 sigblob = key->alg->sign(key->data, (char *)sigdata,
5150 sigdata_len, &sigblob_len);
5151 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5152 sigblob, sigblob_len);
5158 s->type = AUTH_TYPE_PUBLICKEY;
5160 } else if (s->method == AUTH_PASSWORD) {
5162 * We send the password packet lumped tightly together with
5163 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5164 * string long enough to make the total length of the two
5165 * packets constant. This should ensure that a passive
5166 * listener doing traffic analyis can't work out the length
5169 * For this to work, we need an assumption about the
5170 * maximum length of the password packet. I think 256 is
5171 * pretty conservative. Anyone using a password longer than
5172 * that probably doesn't have much to worry about from
5173 * people who find out how long their password is!
5175 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5176 ssh2_pkt_addstring(ssh, s->username);
5177 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5178 ssh2_pkt_addstring(ssh, "password");
5179 ssh2_pkt_addbool(ssh, FALSE);
5180 ssh2_pkt_addstring(ssh, s->password);
5181 memset(s->password, 0, sizeof(s->password));
5182 ssh2_pkt_defer(ssh);
5184 * We'll include a string that's an exact multiple of the
5185 * cipher block size. If the cipher is NULL for some
5186 * reason, we don't do this trick at all because we gain
5189 if (ssh->cscipher) {
5192 stringlen = (256 - ssh->deferred_len);
5193 stringlen += ssh->cscipher->blksize - 1;
5194 stringlen -= (stringlen % ssh->cscipher->blksize);
5197 * Temporarily disable actual compression,
5198 * so we can guarantee to get this string
5199 * exactly the length we want it. The
5200 * compression-disabling routine should
5201 * return an integer indicating how many
5202 * bytes we should adjust our string length
5206 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5208 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5209 ssh2_pkt_addstring_start(ssh);
5210 for (i = 0; i < stringlen; i++) {
5211 char c = (char) random_byte();
5212 ssh2_pkt_addstring_data(ssh, &c, 1);
5214 ssh2_pkt_defer(ssh);
5216 ssh_pkt_defersend(ssh);
5217 logevent("Sent password");
5218 s->type = AUTH_TYPE_PASSWORD;
5219 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5220 if (s->curr_prompt == 0) {
5221 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5222 ssh2_pkt_adduint32(ssh, s->num_prompts);
5224 if (s->need_pw) { /* only add pw if we just got one! */
5225 ssh2_pkt_addstring(ssh, s->password);
5226 memset(s->password, 0, sizeof(s->password));
5229 if (s->curr_prompt >= s->num_prompts) {
5233 * If there are prompts remaining, we set
5234 * `gotit' so that we won't attempt to get
5235 * another packet. Then we go back round the
5236 * loop and will end up retrieving another
5237 * prompt out of the existing packet. Funky or
5242 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5244 c_write_str(ssh, "No supported authentication methods"
5245 " left to try!\r\n");
5246 logevent("No supported authentications offered."
5248 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5249 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5250 ssh2_pkt_addstring(ssh, "No supported authentication"
5251 " methods available");
5252 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5254 ssh_closing((Plug)ssh, NULL, 0, 0);
5258 } while (!s->we_are_in);
5261 * Now we're authenticated for the connection protocol. The
5262 * connection protocol will automatically have started at this
5263 * point; there's no need to send SERVICE_REQUEST.
5267 * So now create a channel with a session in it.
5269 ssh->channels = newtree234(ssh_channelcmp);
5270 ssh->mainchan = snew(struct ssh_channel);
5271 ssh->mainchan->ssh = ssh;
5272 ssh->mainchan->localid = alloc_channel_id(ssh);
5273 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5274 ssh2_pkt_addstring(ssh, "session");
5275 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5276 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5277 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5278 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5280 crWaitUntilV(ispkt);
5281 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5282 bombout(("Server refused to open a session"));
5284 /* FIXME: error data comes back in FAILURE packet */
5286 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5287 bombout(("Server's channel confirmation cited wrong channel"));
5290 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5291 ssh->mainchan->type = CHAN_MAINSESSION;
5292 ssh->mainchan->closes = 0;
5293 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5294 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5295 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5296 add234(ssh->channels, ssh->mainchan);
5297 logevent("Opened channel for session");
5300 * Potentially enable X11 forwarding.
5302 if (ssh->cfg.x11_forward) {
5303 char proto[20], data[64];
5304 logevent("Requesting X11 forwarding");
5305 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5306 data, sizeof(data), ssh->cfg.x11_auth);
5307 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5308 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5309 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5310 ssh2_pkt_addstring(ssh, "x11-req");
5311 ssh2_pkt_addbool(ssh, 1); /* want reply */
5312 ssh2_pkt_addbool(ssh, 0); /* many connections */
5313 ssh2_pkt_addstring(ssh, proto);
5314 ssh2_pkt_addstring(ssh, data);
5315 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5319 crWaitUntilV(ispkt);
5320 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5321 unsigned i = ssh2_pkt_getuint32(ssh);
5322 struct ssh_channel *c;
5323 c = find234(ssh->channels, &i, ssh_channelfind);
5325 continue; /* nonexistent channel */
5326 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5328 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5330 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5331 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5332 bombout(("Unexpected response to X11 forwarding request:"
5333 " packet type %d", ssh->pktin.type));
5336 logevent("X11 forwarding refused");
5338 logevent("X11 forwarding enabled");
5339 ssh->X11_fwd_enabled = TRUE;
5344 * Enable port forwardings.
5349 int sport,dport,sserv,dserv;
5350 char sports[256], dports[256], saddr[256], host[256];
5352 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5353 /* Add port forwardings. */
5354 ssh->portfwd_strptr = ssh->cfg.portfwd;
5355 while (*ssh->portfwd_strptr) {
5356 type = *ssh->portfwd_strptr++;
5359 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5360 if (*ssh->portfwd_strptr == ':') {
5362 * We've seen a colon in the middle of the
5363 * source port number. This means that
5364 * everything we've seen until now is the
5365 * source _address_, so we'll move it into
5366 * saddr and start sports from the beginning
5369 ssh->portfwd_strptr++;
5371 strcpy(saddr, sports);
5374 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5378 if (*ssh->portfwd_strptr == '\t')
5379 ssh->portfwd_strptr++;
5381 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5382 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5385 if (*ssh->portfwd_strptr == ':')
5386 ssh->portfwd_strptr++;
5388 while (*ssh->portfwd_strptr) {
5389 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5392 ssh->portfwd_strptr++;
5393 dport = atoi(dports);
5397 dport = net_service_lookup(dports);
5399 logeventf(ssh, "Service lookup failed for destination"
5400 " port \"%s\"", dports);
5404 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5407 sport = atoi(sports);
5411 sport = net_service_lookup(sports);
5413 logeventf(ssh, "Service lookup failed for source"
5414 " port \"%s\"", sports);
5417 if (sport && dport) {
5419 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5420 sport, ssh, &ssh->cfg);
5421 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5422 " forwarding to %s:%.*s%.*s%d%.*s",
5423 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5424 (int)(*saddr?1:0), ":",
5425 (int)(sserv ? strlen(sports) : 0), sports,
5426 sserv, "(", sport, sserv, ")",
5428 (int)(dserv ? strlen(dports) : 0), dports,
5429 dserv, "(", dport, dserv, ")");
5430 } else if (type == 'D') {
5431 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5432 sport, ssh, &ssh->cfg);
5433 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5434 " doing SOCKS dynamic forwarding",
5435 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5436 (int)(*saddr?1:0), ":",
5437 (int)(sserv ? strlen(sports) : 0), sports,
5438 sserv, "(", sport, sserv, ")");
5440 struct ssh_rportfwd *pf;
5441 pf = snew(struct ssh_rportfwd);
5442 strcpy(pf->dhost, host);
5445 if (add234(ssh->rportfwds, pf) != pf) {
5446 logeventf(ssh, "Duplicate remote port forwarding"
5447 " to %s:%d", host, dport);
5450 logeventf(ssh, "Requesting remote port "
5451 "%.*s%.*s%.*s%.*s%d%.*s"
5452 " forward to %s:%.*s%.*s%d%.*s",
5453 (int)(*saddr?strlen(saddr):0),
5455 (int)(*saddr?1:0), ":",
5456 (int)(sserv ? strlen(sports) : 0), sports,
5457 sserv, "(", sport, sserv, ")",
5459 (int)(dserv ? strlen(dports) : 0), dports,
5460 dserv, "(", dport, dserv, ")");
5461 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5462 ssh2_pkt_addstring(ssh, "tcpip-forward");
5463 ssh2_pkt_addbool(ssh, 1);/* want reply */
5465 ssh2_pkt_addstring(ssh, saddr);
5466 if (ssh->cfg.rport_acceptall)
5467 ssh2_pkt_addstring(ssh, "0.0.0.0");
5469 ssh2_pkt_addstring(ssh, "127.0.0.1");
5470 ssh2_pkt_adduint32(ssh, sport);
5474 crWaitUntilV(ispkt);
5475 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5476 unsigned i = ssh2_pkt_getuint32(ssh);
5477 struct ssh_channel *c;
5478 c = find234(ssh->channels, &i, ssh_channelfind);
5480 continue;/* nonexistent channel */
5481 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5483 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5485 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5486 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5487 bombout(("Unexpected response to port "
5488 "forwarding request: packet type %d",
5492 logevent("Server refused this port forwarding");
5494 logevent("Remote port forwarding enabled");
5503 * Potentially enable agent forwarding.
5505 if (ssh->cfg.agentfwd && agent_exists()) {
5506 logevent("Requesting OpenSSH-style agent forwarding");
5507 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5508 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5509 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5510 ssh2_pkt_addbool(ssh, 1); /* want reply */
5514 crWaitUntilV(ispkt);
5515 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5516 unsigned i = ssh2_pkt_getuint32(ssh);
5517 struct ssh_channel *c;
5518 c = find234(ssh->channels, &i, ssh_channelfind);
5520 continue; /* nonexistent channel */
5521 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5523 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5525 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5526 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5527 bombout(("Unexpected response to agent forwarding request:"
5528 " packet type %d", ssh->pktin.type));
5531 logevent("Agent forwarding refused");
5533 logevent("Agent forwarding enabled");
5534 ssh->agentfwd_enabled = TRUE;
5539 * Now allocate a pty for the session.
5541 if (!ssh->cfg.nopty) {
5542 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5543 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5544 ssh2_pkt_addstring(ssh, "pty-req");
5545 ssh2_pkt_addbool(ssh, 1); /* want reply */
5546 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5547 ssh2_pkt_adduint32(ssh, ssh->term_width);
5548 ssh2_pkt_adduint32(ssh, ssh->term_height);
5549 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5550 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5551 ssh2_pkt_addstring_start(ssh);
5552 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5554 ssh->state = SSH_STATE_INTERMED;
5557 crWaitUntilV(ispkt);
5558 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5559 unsigned i = ssh2_pkt_getuint32(ssh);
5560 struct ssh_channel *c;
5561 c = find234(ssh->channels, &i, ssh_channelfind);
5563 continue; /* nonexistent channel */
5564 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5566 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5568 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5569 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5570 bombout(("Unexpected response to pty request:"
5571 " packet type %d", ssh->pktin.type));
5574 c_write_str(ssh, "Server refused to allocate pty\r\n");
5575 ssh->editing = ssh->echoing = 1;
5577 logevent("Allocated pty");
5580 ssh->editing = ssh->echoing = 1;
5584 * Start a shell or a remote command. We may have to attempt
5585 * this twice if the config data has provided a second choice
5592 if (ssh->fallback_cmd) {
5593 subsys = ssh->cfg.ssh_subsys2;
5594 cmd = ssh->cfg.remote_cmd_ptr2;
5596 subsys = ssh->cfg.ssh_subsys;
5597 cmd = ssh->cfg.remote_cmd_ptr;
5600 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5601 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5603 ssh2_pkt_addstring(ssh, "subsystem");
5604 ssh2_pkt_addbool(ssh, 1); /* want reply */
5605 ssh2_pkt_addstring(ssh, cmd);
5607 ssh2_pkt_addstring(ssh, "exec");
5608 ssh2_pkt_addbool(ssh, 1); /* want reply */
5609 ssh2_pkt_addstring(ssh, cmd);
5611 ssh2_pkt_addstring(ssh, "shell");
5612 ssh2_pkt_addbool(ssh, 1); /* want reply */
5616 crWaitUntilV(ispkt);
5617 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5618 unsigned i = ssh2_pkt_getuint32(ssh);
5619 struct ssh_channel *c;
5620 c = find234(ssh->channels, &i, ssh_channelfind);
5622 continue; /* nonexistent channel */
5623 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5625 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5626 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5627 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5628 bombout(("Unexpected response to shell/command request:"
5629 " packet type %d", ssh->pktin.type));
5633 * We failed to start the command. If this is the
5634 * fallback command, we really are finished; if it's
5635 * not, and if the fallback command exists, try falling
5636 * back to it before complaining.
5638 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5639 logevent("Primary command failed; attempting fallback");
5640 ssh->fallback_cmd = TRUE;
5643 bombout(("Server refused to start a shell/command"));
5646 logevent("Started a shell/command");
5651 ssh->state = SSH_STATE_SESSION;
5652 if (ssh->size_needed)
5653 ssh_size(ssh, ssh->term_width, ssh->term_height);
5654 if (ssh->eof_needed)
5655 ssh_special(ssh, TS_EOF);
5661 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5665 s->try_send = FALSE;
5667 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5668 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5671 unsigned i = ssh2_pkt_getuint32(ssh);
5672 struct ssh_channel *c;
5673 c = find234(ssh->channels, &i, ssh_channelfind);
5675 continue; /* nonexistent channel */
5676 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5677 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5678 continue; /* extended but not stderr */
5679 ssh2_pkt_getstring(ssh, &data, &length);
5682 c->v.v2.locwindow -= length;
5684 case CHAN_MAINSESSION:
5686 from_backend(ssh->frontend, ssh->pktin.type ==
5687 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5691 bufsize = x11_send(c->u.x11.s, data, length);
5694 bufsize = pfd_send(c->u.pfd.s, data, length);
5697 while (length > 0) {
5698 if (c->u.a.lensofar < 4) {
5699 int l = min(4 - c->u.a.lensofar, length);
5700 memcpy(c->u.a.msglen + c->u.a.lensofar,
5704 c->u.a.lensofar += l;
5706 if (c->u.a.lensofar == 4) {
5708 4 + GET_32BIT(c->u.a.msglen);
5709 c->u.a.message = snewn(c->u.a.totallen,
5711 memcpy(c->u.a.message, c->u.a.msglen, 4);
5713 if (c->u.a.lensofar >= 4 && length > 0) {
5715 min(c->u.a.totallen - c->u.a.lensofar,
5717 memcpy(c->u.a.message + c->u.a.lensofar,
5721 c->u.a.lensofar += l;
5723 if (c->u.a.lensofar == c->u.a.totallen) {
5726 if (agent_query(c->u.a.message,
5729 ssh_agentf_callback, c))
5730 ssh_agentf_callback(c, reply, replylen);
5731 sfree(c->u.a.message);
5732 c->u.a.lensofar = 0;
5739 * If we are not buffering too much data,
5740 * enlarge the window again at the remote side.
5742 if (bufsize < OUR_V2_WINSIZE)
5743 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5745 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5746 unsigned i = ssh2_pkt_getuint32(ssh);
5747 struct ssh_channel *c;
5749 c = find234(ssh->channels, &i, ssh_channelfind);
5751 continue; /* nonexistent channel */
5753 if (c->type == CHAN_X11) {
5755 * Remote EOF on an X11 channel means we should
5756 * wrap up and close the channel ourselves.
5758 x11_close(c->u.x11.s);
5760 } else if (c->type == CHAN_AGENT) {
5762 } else if (c->type == CHAN_SOCKDATA) {
5763 pfd_close(c->u.pfd.s);
5766 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5767 unsigned i = ssh2_pkt_getuint32(ssh);
5768 struct ssh_channel *c;
5770 c = find234(ssh->channels, &i, ssh_channelfind);
5771 if (!c || ((int)c->remoteid) == -1) {
5772 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5773 c ? "half-open" : "nonexistent", i));
5776 /* Do pre-close processing on the channel. */
5778 case CHAN_MAINSESSION:
5779 break; /* nothing to see here, move along */
5781 if (c->u.x11.s != NULL)
5782 x11_close(c->u.x11.s);
5789 if (c->u.pfd.s != NULL)
5790 pfd_close(c->u.pfd.s);
5794 if (c->closes == 0) {
5795 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5796 ssh2_pkt_adduint32(ssh, c->remoteid);
5799 del234(ssh->channels, c);
5800 bufchain_clear(&c->v.v2.outbuffer);
5804 * See if that was the last channel left open.
5806 if (count234(ssh->channels) == 0) {
5807 logevent("All channels closed. Disconnecting");
5810 * We used to send SSH_MSG_DISCONNECT here,
5811 * because I'd believed that _every_ conforming
5812 * SSH2 connection had to end with a disconnect
5813 * being sent by at least one side; apparently
5814 * I was wrong and it's perfectly OK to
5815 * unceremoniously slam the connection shut
5816 * when you're done, and indeed OpenSSH feels
5817 * this is more polite than sending a
5818 * DISCONNECT. So now we don't.
5820 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5821 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5822 ssh2_pkt_addstring(ssh, "All open channels closed");
5823 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5826 ssh_closing((Plug)ssh, NULL, 0, 0);
5829 continue; /* remote sends close; ignore (FIXME) */
5830 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5831 unsigned i = ssh2_pkt_getuint32(ssh);
5832 struct ssh_channel *c;
5833 c = find234(ssh->channels, &i, ssh_channelfind);
5834 if (!c || c->closes)
5835 continue; /* nonexistent or closing channel */
5836 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5838 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5839 unsigned i = ssh2_pkt_getuint32(ssh);
5840 struct ssh_channel *c;
5841 c = find234(ssh->channels, &i, ssh_channelfind);
5843 continue; /* nonexistent channel */
5844 if (c->type != CHAN_SOCKDATA_DORMANT)
5845 continue; /* dunno why they're confirming this */
5846 c->remoteid = ssh2_pkt_getuint32(ssh);
5847 c->type = CHAN_SOCKDATA;
5848 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5849 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5851 pfd_confirm(c->u.pfd.s);
5854 * We have a pending close on this channel,
5855 * which we decided on before the server acked
5856 * the channel open. So now we know the
5857 * remoteid, we can close it again.
5859 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5860 ssh2_pkt_adduint32(ssh, c->remoteid);
5863 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5864 unsigned i = ssh2_pkt_getuint32(ssh);
5865 struct ssh_channel *c;
5866 c = find234(ssh->channels, &i, ssh_channelfind);
5868 continue; /* nonexistent channel */
5869 if (c->type != CHAN_SOCKDATA_DORMANT)
5870 continue; /* dunno why they're failing this */
5872 logevent("Forwarded connection refused by server");
5874 pfd_close(c->u.pfd.s);
5876 del234(ssh->channels, c);
5878 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5881 int typelen, want_reply;
5882 struct ssh_channel *c;
5884 localid = ssh2_pkt_getuint32(ssh);
5885 ssh2_pkt_getstring(ssh, &type, &typelen);
5886 want_reply = ssh2_pkt_getbool(ssh);
5889 * First, check that the channel exists. Otherwise,
5890 * we can instantly disconnect with a rude message.
5892 c = find234(ssh->channels, &localid, ssh_channelfind);
5895 sprintf(buf, "Received channel request for nonexistent"
5896 " channel %d", localid);
5898 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5899 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5900 ssh2_pkt_addstring(ssh, buf);
5901 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5903 connection_fatal(ssh->frontend, "%s", buf);
5904 ssh_closing((Plug)ssh, NULL, 0, 0);
5909 * Having got the channel number, we now look at
5910 * the request type string to see if it's something
5913 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5914 c == ssh->mainchan) {
5915 /* We recognise "exit-status" on the primary channel. */
5917 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5918 sprintf(buf, "Server sent command exit status %d",
5922 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5923 ssh2_pkt_adduint32(ssh, c->remoteid);
5928 * This is a channel request we don't know
5929 * about, so we now either ignore the request
5930 * or respond with CHANNEL_FAILURE, depending
5934 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5935 ssh2_pkt_adduint32(ssh, c->remoteid);
5939 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5941 int typelen, want_reply;
5943 ssh2_pkt_getstring(ssh, &type, &typelen);
5944 want_reply = ssh2_pkt_getbool(ssh);
5947 * We currently don't support any global requests
5948 * at all, so we either ignore the request or
5949 * respond with REQUEST_FAILURE, depending on
5953 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5956 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5963 struct ssh_channel *c;
5964 unsigned remid, winsize, pktsize;
5965 ssh2_pkt_getstring(ssh, &type, &typelen);
5966 c = snew(struct ssh_channel);
5969 remid = ssh2_pkt_getuint32(ssh);
5970 winsize = ssh2_pkt_getuint32(ssh);
5971 pktsize = ssh2_pkt_getuint32(ssh);
5973 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5976 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5977 addrstr = snewn(peeraddrlen+1, char);
5978 memcpy(addrstr, peeraddr, peeraddrlen);
5979 peeraddr[peeraddrlen] = '\0';
5980 peerport = ssh2_pkt_getuint32(ssh);
5982 if (!ssh->X11_fwd_enabled)
5983 error = "X11 forwarding is not enabled";
5984 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5985 ssh->x11auth, addrstr, peerport,
5986 &ssh->cfg) != NULL) {
5987 error = "Unable to open an X11 connection";
5993 } else if (typelen == 15 &&
5994 !memcmp(type, "forwarded-tcpip", 15)) {
5995 struct ssh_rportfwd pf, *realpf;
5998 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5999 pf.sport = ssh2_pkt_getuint32(ssh);
6000 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6001 peerport = ssh2_pkt_getuint32(ssh);
6002 realpf = find234(ssh->rportfwds, &pf, NULL);
6003 if (realpf == NULL) {
6004 error = "Remote port is not recognised";
6006 const char *e = pfd_newconnect(&c->u.pfd.s,
6010 logeventf(ssh, "Received remote port open request"
6011 " for %s:%d", realpf->dhost, realpf->dport);
6013 logeventf(ssh, "Port open failed: %s", e);
6014 error = "Port open failed";
6016 logevent("Forwarded port opened successfully");
6017 c->type = CHAN_SOCKDATA;
6020 } else if (typelen == 22 &&
6021 !memcmp(type, "auth-agent@openssh.com", 3)) {
6022 if (!ssh->agentfwd_enabled)
6023 error = "Agent forwarding is not enabled";
6025 c->type = CHAN_AGENT; /* identify channel type */
6026 c->u.a.lensofar = 0;
6029 error = "Unsupported channel type requested";
6032 c->remoteid = remid;
6034 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6035 ssh2_pkt_adduint32(ssh, c->remoteid);
6036 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6037 ssh2_pkt_addstring(ssh, error);
6038 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6042 c->localid = alloc_channel_id(ssh);
6044 c->v.v2.locwindow = OUR_V2_WINSIZE;
6045 c->v.v2.remwindow = winsize;
6046 c->v.v2.remmaxpkt = pktsize;
6047 bufchain_init(&c->v.v2.outbuffer);
6048 add234(ssh->channels, c);
6049 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6050 ssh2_pkt_adduint32(ssh, c->remoteid);
6051 ssh2_pkt_adduint32(ssh, c->localid);
6052 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6053 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6057 bombout(("Strange packet received: type %d", ssh->pktin.type));
6062 * We have spare data. Add it to the channel buffer.
6064 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6069 struct ssh_channel *c;
6071 * Try to send data on all channels if we can.
6073 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6076 continue; /* don't send on closing channels */
6077 bufsize = ssh2_try_send(c);
6080 case CHAN_MAINSESSION:
6081 /* stdin need not receive an unthrottle
6082 * notification since it will be polled */
6085 x11_unthrottle(c->u.x11.s);
6088 /* agent sockets are request/response and need no
6089 * buffer management */
6092 pfd_unthrottle(c->u.pfd.s);
6104 * Handle the top-level SSH2 protocol.
6106 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6108 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6110 do_ssh2_authconn(ssh, in, inlen, ispkt);
6114 * Called to set up the connection.
6116 * Returns an error message, or NULL on success.
6118 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6120 char *host, int port, char **realhost, int nodelay)
6125 ssh = snew(struct ssh_tag);
6126 ssh->cfg = *cfg; /* STRUCTURE COPY */
6127 ssh->version = 0; /* when not ready yet */
6130 ssh->v1_cipher_ctx = NULL;
6131 ssh->crcda_ctx = NULL;
6132 ssh->cscipher = NULL;
6133 ssh->cs_cipher_ctx = NULL;
6134 ssh->sccipher = NULL;
6135 ssh->sc_cipher_ctx = NULL;
6137 ssh->cs_mac_ctx = NULL;
6139 ssh->sc_mac_ctx = NULL;
6141 ssh->cs_comp_ctx = NULL;
6143 ssh->sc_comp_ctx = NULL;
6145 ssh->kex_ctx = NULL;
6146 ssh->hostkey = NULL;
6148 ssh->state = SSH_STATE_PREPACKET;
6149 ssh->size_needed = FALSE;
6150 ssh->eof_needed = FALSE;
6154 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6155 ssh->pktin = ssh->pktout = empty;
6157 ssh->deferred_send_data = NULL;
6158 ssh->deferred_len = 0;
6159 ssh->deferred_size = 0;
6160 ssh->fallback_cmd = 0;
6162 ssh->x11auth = NULL;
6163 ssh->v1_compressing = FALSE;
6164 ssh->v2_outgoing_sequence = 0;
6165 ssh->ssh1_rdpkt_crstate = 0;
6166 ssh->ssh2_rdpkt_crstate = 0;
6167 ssh->do_ssh_init_crstate = 0;
6168 ssh->ssh_gotdata_crstate = 0;
6169 ssh->ssh1_protocol_crstate = 0;
6170 ssh->do_ssh1_login_crstate = 0;
6171 ssh->do_ssh2_transport_crstate = 0;
6172 ssh->do_ssh2_authconn_crstate = 0;
6173 ssh->do_ssh_init_state = NULL;
6174 ssh->do_ssh1_login_state = NULL;
6175 ssh->do_ssh2_transport_state = NULL;
6176 ssh->do_ssh2_authconn_state = NULL;
6177 ssh->mainchan = NULL;
6178 ssh->throttled_all = 0;
6179 ssh->v1_stdout_throttling = 0;
6181 *backend_handle = ssh;
6184 if (crypto_startup() == 0)
6185 return "Microsoft high encryption pack not installed!";
6188 ssh->frontend = frontend_handle;
6189 ssh->term_width = ssh->cfg.width;
6190 ssh->term_height = ssh->cfg.height;
6192 ssh->channels = NULL;
6193 ssh->rportfwds = NULL;
6198 ssh->v1_throttle_count = 0;
6199 ssh->overall_bufsize = 0;
6200 ssh->fallback_cmd = 0;
6202 ssh->protocol = NULL;
6204 p = connect_to_host(ssh, host, port, realhost, nodelay);
6211 static void ssh_free(void *handle)
6213 Ssh ssh = (Ssh) handle;
6214 struct ssh_channel *c;
6215 struct ssh_rportfwd *pf;
6217 if (ssh->v1_cipher_ctx)
6218 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6219 if (ssh->cs_cipher_ctx)
6220 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6221 if (ssh->sc_cipher_ctx)
6222 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6223 if (ssh->cs_mac_ctx)
6224 ssh->csmac->free_context(ssh->cs_mac_ctx);
6225 if (ssh->sc_mac_ctx)
6226 ssh->scmac->free_context(ssh->sc_mac_ctx);
6227 if (ssh->cs_comp_ctx)
6228 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6229 if (ssh->sc_comp_ctx)
6230 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6232 dh_cleanup(ssh->kex_ctx);
6233 sfree(ssh->savedhost);
6235 if (ssh->channels) {
6236 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6239 if (c->u.x11.s != NULL)
6240 x11_close(c->u.x11.s);
6243 if (c->u.pfd.s != NULL)
6244 pfd_close(c->u.pfd.s);
6249 freetree234(ssh->channels);
6252 if (ssh->rportfwds) {
6253 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6255 freetree234(ssh->rportfwds);
6257 sfree(ssh->deferred_send_data);
6259 x11_free_auth(ssh->x11auth);
6260 sfree(ssh->do_ssh_init_state);
6261 sfree(ssh->do_ssh1_login_state);
6262 sfree(ssh->do_ssh2_transport_state);
6263 sfree(ssh->do_ssh2_authconn_state);
6271 * Reconfigure the SSH backend.
6273 * Currently, this function does nothing very useful. In future,
6274 * however, we could do some handy things with it. For example, we
6275 * could make the port forwarding configurer active in the Change
6276 * Settings box, and this routine could close down existing
6277 * forwardings and open up new ones in response to changes.
6279 static void ssh_reconfig(void *handle, Config *cfg)
6281 Ssh ssh = (Ssh) handle;
6282 ssh->cfg = *cfg; /* STRUCTURE COPY */
6286 * Called to send data down the Telnet connection.
6288 static int ssh_send(void *handle, char *buf, int len)
6290 Ssh ssh = (Ssh) handle;
6292 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6295 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6297 return ssh_sendbuffer(ssh);
6301 * Called to query the current amount of buffered stdin data.
6303 static int ssh_sendbuffer(void *handle)
6305 Ssh ssh = (Ssh) handle;
6308 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6312 * If the SSH socket itself has backed up, add the total backup
6313 * size on that to any individual buffer on the stdin channel.
6316 if (ssh->throttled_all)
6317 override_value = ssh->overall_bufsize;
6319 if (ssh->version == 1) {
6320 return override_value;
6321 } else if (ssh->version == 2) {
6322 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6323 return override_value;
6325 return (override_value +
6326 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6333 * Called to set the size of the window from SSH's POV.
6335 static void ssh_size(void *handle, int width, int height)
6337 Ssh ssh = (Ssh) handle;
6339 ssh->term_width = width;
6340 ssh->term_height = height;
6342 switch (ssh->state) {
6343 case SSH_STATE_BEFORE_SIZE:
6344 case SSH_STATE_PREPACKET:
6345 case SSH_STATE_CLOSED:
6346 break; /* do nothing */
6347 case SSH_STATE_INTERMED:
6348 ssh->size_needed = TRUE; /* buffer for later */
6350 case SSH_STATE_SESSION:
6351 if (!ssh->cfg.nopty) {
6352 if (ssh->version == 1) {
6353 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6354 PKT_INT, ssh->term_height,
6355 PKT_INT, ssh->term_width,
6356 PKT_INT, 0, PKT_INT, 0, PKT_END);
6358 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6359 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6360 ssh2_pkt_addstring(ssh, "window-change");
6361 ssh2_pkt_addbool(ssh, 0);
6362 ssh2_pkt_adduint32(ssh, ssh->term_width);
6363 ssh2_pkt_adduint32(ssh, ssh->term_height);
6364 ssh2_pkt_adduint32(ssh, 0);
6365 ssh2_pkt_adduint32(ssh, 0);
6374 * Return a list of the special codes that make sense in this
6377 static const struct telnet_special *ssh_get_specials(void *handle)
6379 Ssh ssh = (Ssh) handle;
6381 if (ssh->version == 1) {
6382 static const struct telnet_special ssh1_specials[] = {
6383 {"IGNORE message", TS_NOP},
6386 return ssh1_specials;
6387 } else if (ssh->version == 2) {
6388 static const struct telnet_special ssh2_specials[] = {
6390 {"IGNORE message", TS_NOP},
6393 return ssh2_specials;
6399 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6400 * can send an EOF and collect resulting output (e.g. `plink
6403 static void ssh_special(void *handle, Telnet_Special code)
6405 Ssh ssh = (Ssh) handle;
6407 if (code == TS_EOF) {
6408 if (ssh->state != SSH_STATE_SESSION) {
6410 * Buffer the EOF in case we are pre-SESSION, so we can
6411 * send it as soon as we reach SESSION.
6414 ssh->eof_needed = TRUE;
6417 if (ssh->version == 1) {
6418 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6420 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6421 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6424 logevent("Sent EOF message");
6425 } else if (code == TS_PING || code == TS_NOP) {
6426 if (ssh->state == SSH_STATE_CLOSED
6427 || ssh->state == SSH_STATE_PREPACKET) return;
6428 if (ssh->version == 1) {
6429 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6430 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6432 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6433 ssh2_pkt_addstring_start(ssh);
6436 } else if (code == TS_BRK) {
6437 if (ssh->state == SSH_STATE_CLOSED
6438 || ssh->state == SSH_STATE_PREPACKET) return;
6439 if (ssh->version == 1) {
6440 logevent("Unable to send BREAK signal in SSH1");
6442 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6443 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6444 ssh2_pkt_addstring(ssh, "break");
6445 ssh2_pkt_addbool(ssh, 0);
6446 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6454 void *new_sock_channel(void *handle, Socket s)
6456 Ssh ssh = (Ssh) handle;
6457 struct ssh_channel *c;
6458 c = snew(struct ssh_channel);
6462 c->remoteid = -1; /* to be set when open confirmed */
6463 c->localid = alloc_channel_id(ssh);
6465 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6467 bufchain_init(&c->v.v2.outbuffer);
6468 add234(ssh->channels, c);
6474 * This is called when stdout/stderr (the entity to which
6475 * from_backend sends data) manages to clear some backlog.
6477 static void ssh_unthrottle(void *handle, int bufsize)
6479 Ssh ssh = (Ssh) handle;
6480 if (ssh->version == 1) {
6481 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6482 ssh->v1_stdout_throttling = 0;
6483 ssh1_throttle(ssh, -1);
6486 if (ssh->mainchan && ssh->mainchan->closes == 0)
6487 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6491 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6493 struct ssh_channel *c = (struct ssh_channel *)channel;
6496 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6498 if (ssh->version == 1) {
6499 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6500 PKT_INT, c->localid,
6503 //PKT_STR, <org:orgport>,
6506 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6507 ssh2_pkt_addstring(ssh, "direct-tcpip");
6508 ssh2_pkt_adduint32(ssh, c->localid);
6509 c->v.v2.locwindow = OUR_V2_WINSIZE;
6510 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6511 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6512 ssh2_pkt_addstring(ssh, hostname);
6513 ssh2_pkt_adduint32(ssh, port);
6515 * We make up values for the originator data; partly it's
6516 * too much hassle to keep track, and partly I'm not
6517 * convinced the server should be told details like that
6518 * about my local network configuration.
6520 ssh2_pkt_addstring(ssh, "client-side-connection");
6521 ssh2_pkt_adduint32(ssh, 0);
6527 static Socket ssh_socket(void *handle)
6529 Ssh ssh = (Ssh) handle;
6533 static int ssh_sendok(void *handle)
6535 Ssh ssh = (Ssh) handle;
6536 return ssh->send_ok;
6539 static int ssh_ldisc(void *handle, int option)
6541 Ssh ssh = (Ssh) handle;
6542 if (option == LD_ECHO)
6543 return ssh->echoing;
6544 if (option == LD_EDIT)
6545 return ssh->editing;
6549 static void ssh_provide_ldisc(void *handle, void *ldisc)
6551 Ssh ssh = (Ssh) handle;
6555 static void ssh_provide_logctx(void *handle, void *logctx)
6557 Ssh ssh = (Ssh) handle;
6558 ssh->logctx = logctx;
6561 static int ssh_return_exitcode(void *handle)
6563 Ssh ssh = (Ssh) handle;
6567 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6571 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6572 * that fails. This variable is the means by which scp.c can reach
6573 * into the SSH code and find out which one it got.
6575 extern int ssh_fallback_cmd(void *handle)
6577 Ssh ssh = (Ssh) handle;
6578 return ssh->fallback_cmd;
6581 Backend ssh_backend = {
6591 ssh_return_exitcode,