17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
166 #define BUG_SSH2_PK_SESSIONID 128
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
279 * which explains the theory behind these macros.
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
286 * - right-click ssh.c in the FileView
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
292 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
295 if (!ssh->t) ssh->t = snew(struct t); \
297 #define crFinish(z) } *crLine = 0; return (z); }
298 #define crFinishV } *crLine = 0; return; }
299 #define crReturn(z) \
301 *crLine =__LINE__; return (z); case __LINE__:;\
305 *crLine=__LINE__; return; case __LINE__:;\
307 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
308 #define crStopV do{ *crLine = 0; return; }while(0)
309 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
310 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
312 typedef struct ssh_tag *Ssh;
314 static void ssh2_pkt_init(Ssh, int pkt_type);
315 static void ssh2_pkt_addbool(Ssh, unsigned char value);
316 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317 static void ssh2_pkt_addstring_start(Ssh);
318 static void ssh2_pkt_addstring_str(Ssh, char *data);
319 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320 static void ssh2_pkt_addstring(Ssh, char *data);
321 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
322 static void ssh2_pkt_addmp(Ssh, Bignum b);
323 static int ssh2_pkt_construct(Ssh);
324 static void ssh2_pkt_send(Ssh);
325 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
326 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
329 * Buffer management constants. There are several of these for
330 * various different purposes:
332 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
333 * on a local data stream before we throttle the whole SSH
334 * connection (in SSH1 only). Throttling the whole connection is
335 * pretty drastic so we set this high in the hope it won't
338 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
339 * on the SSH connection itself before we defensively throttle
340 * _all_ local data streams. This is pretty drastic too (though
341 * thankfully unlikely in SSH2 since the window mechanism should
342 * ensure that the server never has any need to throttle its end
343 * of the connection), so we set this high as well.
345 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
349 #define SSH1_BUFFER_LIMIT 32768
350 #define SSH_MAX_BACKLOG 32768
351 #define OUR_V2_WINSIZE 16384
353 const static struct ssh_kex *kex_algs[] = {
354 &ssh_diffiehellman_gex,
358 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
360 static void *nullmac_make_context(void)
364 static void nullmac_free_context(void *handle)
367 static void nullmac_key(void *handle, unsigned char *key)
370 static void nullmac_generate(void *handle, unsigned char *blk, int len,
374 static int nullmac_verify(void *handle, unsigned char *blk, int len,
379 const static struct ssh_mac ssh_mac_none = {
380 nullmac_make_context, nullmac_free_context, nullmac_key,
381 nullmac_generate, nullmac_verify, "none", 0
383 const static struct ssh_mac *macs[] = {
384 &ssh_sha1, &ssh_md5, &ssh_mac_none
386 const static struct ssh_mac *buggymacs[] = {
387 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
390 static void *ssh_comp_none_init(void)
394 static void ssh_comp_none_cleanup(void *handle)
397 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
398 unsigned char **outblock, int *outlen)
402 static int ssh_comp_none_disable(void *handle)
406 const static struct ssh_compress ssh_comp_none = {
408 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
409 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
410 ssh_comp_none_disable, NULL
412 extern const struct ssh_compress ssh_zlib;
413 const static struct ssh_compress *compressions[] = {
414 &ssh_zlib, &ssh_comp_none
417 enum { /* channel types */
422 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
426 * 2-3-4 tree storing channels.
429 Ssh ssh; /* pointer back to main context */
430 unsigned remoteid, localid;
433 * In SSH1, this value contains four bits:
435 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
436 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
438 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
440 * A channel is completely finished with when all four bits are set.
444 struct ssh1_data_channel {
447 struct ssh2_data_channel {
449 unsigned remwindow, remmaxpkt;
454 struct ssh_agent_channel {
455 unsigned char *message;
456 unsigned char msglen[4];
457 int lensofar, totallen;
459 struct ssh_x11_channel {
462 struct ssh_pfd_channel {
469 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
470 * 2 use this structure in different ways, reflecting SSH 2's
471 * altogether saner approach to port forwarding.
473 * In SSH 1, you arrange a remote forwarding by sending the server
474 * the remote port number, and the local destination host:port.
475 * When a connection comes in, the server sends you back that
476 * host:port pair, and you connect to it. This is a ready-made
477 * security hole if you're not on the ball: a malicious server
478 * could send you back _any_ host:port pair, so if you trustingly
479 * connect to the address it gives you then you've just opened the
480 * entire inside of your corporate network just by connecting
481 * through it to a dodgy SSH server. Hence, we must store a list of
482 * host:port pairs we _are_ trying to forward to, and reject a
483 * connection request from the server if it's not in the list.
485 * In SSH 2, each side of the connection minds its own business and
486 * doesn't send unnecessary information to the other. You arrange a
487 * remote forwarding by sending the server just the remote port
488 * number. When a connection comes in, the server tells you which
489 * of its ports was connected to; and _you_ have to remember what
490 * local host:port pair went with that port number.
492 * Hence: in SSH 1 this structure stores host:port pairs we intend
493 * to allow connections to, and is indexed by those host:port
494 * pairs. In SSH 2 it stores a mapping from source port to
495 * destination host:port pair, and is indexed by source port.
497 struct ssh_rportfwd {
498 unsigned sport, dport;
511 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
512 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
513 static void ssh_size(void *handle, int width, int height);
514 static void ssh_special(void *handle, Telnet_Special);
515 static int ssh2_try_send(struct ssh_channel *c);
516 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
517 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
518 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
519 static int ssh_sendbuffer(void *handle);
520 static void ssh_do_close(Ssh ssh);
522 struct rdpkt1_state_tag {
523 long len, pad, biglen, to_read;
524 unsigned long realcrc, gotcrc;
530 struct rdpkt2_state_tag {
531 long len, pad, payload, packetlen, maclen;
534 unsigned long incoming_sequence;
538 const struct plug_function_table *fn;
539 /* the above field _must_ be first in the structure */
541 SHA_State exhash, exhashbase;
548 unsigned char session_key[32];
550 int v1_remote_protoflags;
551 int v1_local_protoflags;
552 int agentfwd_enabled;
555 const struct ssh_cipher *cipher;
558 const struct ssh2_cipher *cscipher, *sccipher;
559 void *cs_cipher_ctx, *sc_cipher_ctx;
560 const struct ssh_mac *csmac, *scmac;
561 void *cs_mac_ctx, *sc_mac_ctx;
562 const struct ssh_compress *cscomp, *sccomp;
563 void *cs_comp_ctx, *sc_comp_ctx;
564 const struct ssh_kex *kex;
565 const struct ssh_signkey *hostkey;
566 unsigned char v2_session_id[20];
572 int echoing, editing;
576 int term_width, term_height;
578 tree234 *channels; /* indexed by local id */
579 struct ssh_channel *mainchan; /* primary session channel */
586 SSH_STATE_BEFORE_SIZE,
592 int size_needed, eof_needed;
595 struct Packet pktout;
596 unsigned char *deferred_send_data;
597 int deferred_len, deferred_size;
600 * Gross hack: pscp will try to start SFTP but fall back to
601 * scp1 if that fails. This variable is the means by which
602 * scp.c can reach into the SSH code and find out which one it
608 * Used for username and password input.
610 char *userpass_input_buffer;
611 int userpass_input_buflen;
612 int userpass_input_bufpos;
613 int userpass_input_echo;
615 char *portfwd_strptr;
621 int v1_throttle_count;
624 int v1_stdout_throttling;
625 int v2_outgoing_sequence;
627 int ssh1_rdpkt_crstate;
628 int ssh2_rdpkt_crstate;
629 int do_ssh_init_crstate;
630 int ssh_gotdata_crstate;
631 int ssh1_protocol_crstate;
632 int do_ssh1_login_crstate;
633 int do_ssh2_transport_crstate;
634 int do_ssh2_authconn_crstate;
636 void *do_ssh_init_state;
637 void *do_ssh1_login_state;
638 void *do_ssh2_transport_state;
639 void *do_ssh2_authconn_state;
641 struct rdpkt1_state_tag rdpkt1_state;
642 struct rdpkt2_state_tag rdpkt2_state;
644 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
645 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
648 * We maintain a full _copy_ of a Config structure here, not
649 * merely a pointer to it. That way, when we're passed a new
650 * one for reconfiguration, we can check the differences and
651 * potentially reconfigure port forwardings etc in mid-session.
656 * Used to transfer data back from async agent callbacks.
658 void *agent_response;
659 int agent_response_len;
662 #define logevent(s) logevent(ssh->frontend, s)
664 /* logevent, only printf-formatted. */
665 static void logeventf(Ssh ssh, const char *fmt, ...)
671 buf = dupvprintf(fmt, ap);
677 #define bombout(msg) \
679 char *text = dupprintf msg; \
682 connection_fatal(ssh->frontend, "%s", text); \
686 static int ssh_channelcmp(void *av, void *bv)
688 struct ssh_channel *a = (struct ssh_channel *) av;
689 struct ssh_channel *b = (struct ssh_channel *) bv;
690 if (a->localid < b->localid)
692 if (a->localid > b->localid)
696 static int ssh_channelfind(void *av, void *bv)
698 unsigned *a = (unsigned *) av;
699 struct ssh_channel *b = (struct ssh_channel *) bv;
707 static int ssh_rportcmp_ssh1(void *av, void *bv)
709 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
710 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
712 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
713 return i < 0 ? -1 : +1;
714 if (a->dport > b->dport)
716 if (a->dport < b->dport)
721 static int ssh_rportcmp_ssh2(void *av, void *bv)
723 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
724 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
726 if (a->sport > b->sport)
728 if (a->sport < b->sport)
733 static int alloc_channel_id(Ssh ssh)
735 const unsigned CHANNEL_NUMBER_OFFSET = 256;
736 unsigned low, high, mid;
738 struct ssh_channel *c;
741 * First-fit allocation of channel numbers: always pick the
742 * lowest unused one. To do this, binary-search using the
743 * counted B-tree to find the largest channel ID which is in a
744 * contiguous sequence from the beginning. (Precisely
745 * everything in that sequence must have ID equal to its tree
746 * index plus CHANNEL_NUMBER_OFFSET.)
748 tsize = count234(ssh->channels);
752 while (high - low > 1) {
753 mid = (high + low) / 2;
754 c = index234(ssh->channels, mid);
755 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
756 low = mid; /* this one is fine */
758 high = mid; /* this one is past it */
761 * Now low points to either -1, or the tree index of the
762 * largest ID in the initial sequence.
765 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
766 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
768 return low + 1 + CHANNEL_NUMBER_OFFSET;
771 static void c_write(Ssh ssh, const char *buf, int len)
773 if ((flags & FLAG_STDERR)) {
775 for (i = 0; i < len; i++)
777 fputc(buf[i], stderr);
780 from_backend(ssh->frontend, 1, buf, len);
783 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
786 for (i = 0; i < len; i++) {
788 c_write(ssh, "\r\n", 2);
789 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
790 c_write(ssh, buf + i, 1);
794 static void c_write_str(Ssh ssh, const char *buf)
796 c_write(ssh, buf, strlen(buf));
800 * Collect incoming data in the incoming packet buffer.
801 * Decipher and verify the packet when it is completely read.
802 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
803 * Update the *data and *datalen variables.
804 * Return the additional nr of bytes needed, or 0 when
805 * a complete packet is available.
807 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
809 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
811 crBegin(ssh->ssh1_rdpkt_crstate);
816 ssh->pktin.length = 0;
818 for (st->i = st->len = 0; st->i < 4; st->i++) {
819 while ((*datalen) == 0)
821 st->len = (st->len << 8) + **data;
822 (*data)++, (*datalen)--;
825 st->pad = 8 - (st->len % 8);
826 st->biglen = st->len + st->pad;
827 ssh->pktin.length = st->len - 5;
829 if (ssh->pktin.maxlen < st->biglen) {
830 ssh->pktin.maxlen = st->biglen;
831 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
835 st->to_read = st->biglen;
836 st->p = ssh->pktin.data;
837 while (st->to_read > 0) {
838 st->chunk = st->to_read;
839 while ((*datalen) == 0)
840 crReturn(st->to_read);
841 if (st->chunk > (*datalen))
842 st->chunk = (*datalen);
843 memcpy(st->p, *data, st->chunk);
845 *datalen -= st->chunk;
847 st->to_read -= st->chunk;
850 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
852 bombout(("Network attack (CRC compensation) detected!"));
857 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
859 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
860 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
861 if (st->gotcrc != st->realcrc) {
862 bombout(("Incorrect CRC received on packet"));
866 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
868 if (ssh->v1_compressing) {
869 unsigned char *decompblk;
871 if (!zlib_decompress_block(ssh->sc_comp_ctx,
872 ssh->pktin.body - 1, ssh->pktin.length + 1,
873 &decompblk, &decomplen)) {
874 bombout(("Zlib decompression encountered invalid data"));
878 if (ssh->pktin.maxlen < st->pad + decomplen) {
879 ssh->pktin.maxlen = st->pad + decomplen;
880 ssh->pktin.data = sresize(ssh->pktin.data,
881 ssh->pktin.maxlen + APIEXTRA,
883 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
886 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
888 ssh->pktin.length = decomplen - 1;
891 ssh->pktin.type = ssh->pktin.body[-1];
894 log_packet(ssh->logctx,
895 PKT_INCOMING, ssh->pktin.type,
896 ssh1_pkt_type(ssh->pktin.type),
897 ssh->pktin.body, ssh->pktin.length);
899 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
900 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
901 ssh->pktin.type == SSH1_MSG_DEBUG ||
902 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
903 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
904 long stringlen = GET_32BIT(ssh->pktin.body);
905 if (stringlen + 4 != ssh->pktin.length) {
906 bombout(("Received data packet with bogus string length"));
911 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
912 /* log debug message */
914 int stringlen = GET_32BIT(ssh->pktin.body);
915 strcpy(buf, "Remote debug message: ");
918 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
919 buf[8 + stringlen] = '\0';
922 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
927 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
928 /* log reason code in disconnect message */
930 unsigned msglen = GET_32BIT(ssh->pktin.body);
932 strcpy(buf, "Remote sent disconnect: ");
933 nowlen = strlen(buf);
934 if (msglen > sizeof(buf) - nowlen - 1)
935 msglen = sizeof(buf) - nowlen - 1;
936 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
937 buf[nowlen + msglen] = '\0';
938 /* logevent(buf); (this is now done within the bombout macro) */
939 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
946 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
948 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
950 crBegin(ssh->ssh2_rdpkt_crstate);
954 ssh->pktin.length = 0;
956 st->cipherblk = ssh->sccipher->blksize;
959 if (st->cipherblk < 8)
962 if (ssh->pktin.maxlen < st->cipherblk) {
963 ssh->pktin.maxlen = st->cipherblk;
964 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
969 * Acquire and decrypt the first block of the packet. This will
970 * contain the length and padding details.
972 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
973 while ((*datalen) == 0)
974 crReturn(st->cipherblk - st->i);
975 ssh->pktin.data[st->i] = *(*data)++;
980 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
981 ssh->pktin.data, st->cipherblk);
984 * Now get the length and padding figures.
986 st->len = GET_32BIT(ssh->pktin.data);
987 st->pad = ssh->pktin.data[4];
990 * _Completely_ silly lengths should be stomped on before they
991 * do us any more damage.
993 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
994 bombout(("Incoming packet was garbled on decryption"));
999 * This enables us to deduce the payload length.
1001 st->payload = st->len - st->pad - 1;
1003 ssh->pktin.length = st->payload + 5;
1006 * So now we can work out the total packet length.
1008 st->packetlen = st->len + 4;
1009 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1012 * Adjust memory allocation if packet is too big.
1014 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1015 ssh->pktin.maxlen = st->packetlen + st->maclen;
1016 ssh->pktin.data = sresize(ssh->pktin.data,
1017 ssh->pktin.maxlen + APIEXTRA,
1022 * Read and decrypt the remainder of the packet.
1024 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1026 while ((*datalen) == 0)
1027 crReturn(st->packetlen + st->maclen - st->i);
1028 ssh->pktin.data[st->i] = *(*data)++;
1031 /* Decrypt everything _except_ the MAC. */
1033 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1034 ssh->pktin.data + st->cipherblk,
1035 st->packetlen - st->cipherblk);
1041 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1042 st->incoming_sequence)) {
1043 bombout(("Incorrect MAC received on packet"));
1046 st->incoming_sequence++; /* whether or not we MACed */
1049 * Decompress packet payload.
1052 unsigned char *newpayload;
1055 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1056 ssh->pktin.data + 5, ssh->pktin.length - 5,
1057 &newpayload, &newlen)) {
1058 if (ssh->pktin.maxlen < newlen + 5) {
1059 ssh->pktin.maxlen = newlen + 5;
1060 ssh->pktin.data = sresize(ssh->pktin.data,
1061 ssh->pktin.maxlen + APIEXTRA,
1064 ssh->pktin.length = 5 + newlen;
1065 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1070 ssh->pktin.savedpos = 6;
1071 ssh->pktin.type = ssh->pktin.data[5];
1074 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1075 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1076 ssh->pktin.data+6, ssh->pktin.length-6);
1078 switch (ssh->pktin.type) {
1080 * These packets we must handle instantly.
1082 case SSH2_MSG_DISCONNECT:
1084 /* log reason code in disconnect message */
1087 int reason = GET_32BIT(ssh->pktin.data + 6);
1088 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1090 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1091 buf = dupprintf("Received disconnect message (%s)",
1092 ssh2_disconnect_reasons[reason]);
1094 buf = dupprintf("Received disconnect message (unknown"
1095 " type %d)", reason);
1099 buf = dupprintf("Disconnection message text: %n%.*s",
1100 &nowlen, msglen, ssh->pktin.data + 14);
1102 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1104 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1105 ssh2_disconnect_reasons[reason] : "unknown",
1111 case SSH2_MSG_IGNORE:
1113 case SSH2_MSG_DEBUG:
1115 /* log the debug message */
1117 /* int display = ssh->pktin.body[6]; */
1118 int stringlen = GET_32BIT(ssh->pktin.data+7);
1120 strcpy(buf, "Remote debug message: ");
1121 prefix = strlen(buf);
1122 if (stringlen > (int)(sizeof(buf)-prefix-1))
1123 stringlen = sizeof(buf)-prefix-1;
1124 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1125 buf[prefix + stringlen] = '\0';
1128 goto next_packet; /* FIXME: print the debug message */
1131 * These packets we need do nothing about here.
1133 case SSH2_MSG_UNIMPLEMENTED:
1134 case SSH2_MSG_SERVICE_REQUEST:
1135 case SSH2_MSG_SERVICE_ACCEPT:
1136 case SSH2_MSG_KEXINIT:
1137 case SSH2_MSG_NEWKEYS:
1138 case SSH2_MSG_KEXDH_INIT:
1139 case SSH2_MSG_KEXDH_REPLY:
1140 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1141 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1142 case SSH2_MSG_KEX_DH_GEX_INIT:
1143 case SSH2_MSG_KEX_DH_GEX_REPLY:
1144 case SSH2_MSG_USERAUTH_REQUEST:
1145 case SSH2_MSG_USERAUTH_FAILURE:
1146 case SSH2_MSG_USERAUTH_SUCCESS:
1147 case SSH2_MSG_USERAUTH_BANNER:
1148 case SSH2_MSG_USERAUTH_PK_OK:
1149 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1150 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1151 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1152 case SSH2_MSG_GLOBAL_REQUEST:
1153 case SSH2_MSG_REQUEST_SUCCESS:
1154 case SSH2_MSG_REQUEST_FAILURE:
1155 case SSH2_MSG_CHANNEL_OPEN:
1156 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1157 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1158 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1159 case SSH2_MSG_CHANNEL_DATA:
1160 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1161 case SSH2_MSG_CHANNEL_EOF:
1162 case SSH2_MSG_CHANNEL_CLOSE:
1163 case SSH2_MSG_CHANNEL_REQUEST:
1164 case SSH2_MSG_CHANNEL_SUCCESS:
1165 case SSH2_MSG_CHANNEL_FAILURE:
1169 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1172 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1173 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1181 static void ssh1_pktout_size(Ssh ssh, int len)
1185 len += 5; /* type and CRC */
1186 pad = 8 - (len % 8);
1189 ssh->pktout.length = len - 5;
1190 if (ssh->pktout.maxlen < biglen) {
1191 ssh->pktout.maxlen = biglen;
1193 /* Allocate enough buffer space for extra block
1194 * for MS CryptEncrypt() */
1195 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1198 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1202 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1205 static void s_wrpkt_start(Ssh ssh, int type, int len)
1207 ssh1_pktout_size(ssh, len);
1208 ssh->pktout.type = type;
1211 static int s_wrpkt_prepare(Ssh ssh)
1217 * XXX various versions of SC (including 8.8.4) screw up the
1218 * register allocation in this function and use the same register
1219 * (D6) for len and as a temporary, with predictable results. The
1220 * following sledgehammer prevents this.
1226 ssh->pktout.body[-1] = ssh->pktout.type;
1229 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1230 ssh1_pkt_type(ssh->pktout.type),
1231 ssh->pktout.body, ssh->pktout.length);
1233 if (ssh->v1_compressing) {
1234 unsigned char *compblk;
1236 zlib_compress_block(ssh->cs_comp_ctx,
1237 ssh->pktout.body - 1, ssh->pktout.length + 1,
1238 &compblk, &complen);
1239 ssh1_pktout_size(ssh, complen - 1);
1240 memcpy(ssh->pktout.body - 1, compblk, complen);
1244 len = ssh->pktout.length + 5; /* type and CRC */
1245 pad = 8 - (len % 8);
1248 for (i = 0; i < pad; i++)
1249 ssh->pktout.data[i + 4] = random_byte();
1250 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1251 PUT_32BIT(ssh->pktout.data + biglen, crc);
1252 PUT_32BIT(ssh->pktout.data, len);
1255 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1260 static void s_wrpkt(Ssh ssh)
1263 len = s_wrpkt_prepare(ssh);
1264 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1265 if (backlog > SSH_MAX_BACKLOG)
1266 ssh_throttle_all(ssh, 1, backlog);
1269 static void s_wrpkt_defer(Ssh ssh)
1272 len = s_wrpkt_prepare(ssh);
1273 if (ssh->deferred_len + len > ssh->deferred_size) {
1274 ssh->deferred_size = ssh->deferred_len + len + 128;
1275 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1279 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1280 ssh->deferred_len += len;
1284 * Construct a packet with the specified contents.
1286 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1288 unsigned char *p, *argp, argchar;
1289 unsigned long argint;
1290 int pktlen, argtype, arglen;
1294 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1297 (void) va_arg(ap1, int);
1301 (void) va_arg(ap1, int);
1305 (void) va_arg(ap1, unsigned char *);
1306 arglen = va_arg(ap1, int);
1310 argp = va_arg(ap1, unsigned char *);
1311 arglen = strlen((char *)argp);
1312 pktlen += 4 + arglen;
1315 bn = va_arg(ap1, Bignum);
1316 pktlen += ssh1_bignum_length(bn);
1323 s_wrpkt_start(ssh, pkttype, pktlen);
1324 p = ssh->pktout.body;
1326 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1329 argint = va_arg(ap2, int);
1330 PUT_32BIT(p, argint);
1334 argchar = (unsigned char) va_arg(ap2, int);
1339 argp = va_arg(ap2, unsigned char *);
1340 arglen = va_arg(ap2, int);
1341 memcpy(p, argp, arglen);
1345 argp = va_arg(ap2, unsigned char *);
1346 arglen = strlen((char *)argp);
1347 PUT_32BIT(p, arglen);
1348 memcpy(p + 4, argp, arglen);
1352 bn = va_arg(ap2, Bignum);
1353 p += ssh1_write_bignum(p, bn);
1359 static void send_packet(Ssh ssh, int pkttype, ...)
1362 va_start(ap1, pkttype);
1363 va_start(ap2, pkttype);
1364 construct_packet(ssh, pkttype, ap1, ap2);
1368 static void defer_packet(Ssh ssh, int pkttype, ...)
1371 va_start(ap1, pkttype);
1372 va_start(ap2, pkttype);
1373 construct_packet(ssh, pkttype, ap1, ap2);
1377 static int ssh_versioncmp(char *a, char *b)
1380 unsigned long av, bv;
1382 av = strtoul(a, &ae, 10);
1383 bv = strtoul(b, &be, 10);
1385 return (av < bv ? -1 : +1);
1390 av = strtoul(ae, &ae, 10);
1391 bv = strtoul(be, &be, 10);
1393 return (av < bv ? -1 : +1);
1398 * Utility routines for putting an SSH-protocol `string' and
1399 * `uint32' into a SHA state.
1402 static void sha_string(SHA_State * s, void *str, int len)
1404 unsigned char lenblk[4];
1405 PUT_32BIT(lenblk, len);
1406 SHA_Bytes(s, lenblk, 4);
1407 SHA_Bytes(s, str, len);
1410 static void sha_uint32(SHA_State * s, unsigned i)
1412 unsigned char intblk[4];
1413 PUT_32BIT(intblk, i);
1414 SHA_Bytes(s, intblk, 4);
1418 * SSH2 packet construction functions.
1420 static void ssh2_pkt_ensure(Ssh ssh, int length)
1422 if (ssh->pktout.maxlen < length) {
1423 ssh->pktout.maxlen = length + 256;
1424 ssh->pktout.data = sresize(ssh->pktout.data,
1425 ssh->pktout.maxlen + APIEXTRA,
1427 if (!ssh->pktout.data)
1428 fatalbox("Out of memory");
1431 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1433 ssh->pktout.length += len;
1434 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1435 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1437 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1439 ssh2_pkt_adddata(ssh, &byte, 1);
1441 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1443 ssh->pktout.length = 5;
1444 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1446 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1448 ssh2_pkt_adddata(ssh, &value, 1);
1450 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1453 PUT_32BIT(x, value);
1454 ssh2_pkt_adddata(ssh, x, 4);
1456 static void ssh2_pkt_addstring_start(Ssh ssh)
1458 ssh2_pkt_adduint32(ssh, 0);
1459 ssh->pktout.savedpos = ssh->pktout.length;
1461 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1463 ssh2_pkt_adddata(ssh, data, strlen(data));
1464 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1465 ssh->pktout.length - ssh->pktout.savedpos);
1467 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1469 ssh2_pkt_adddata(ssh, data, len);
1470 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1471 ssh->pktout.length - ssh->pktout.savedpos);
1473 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1475 ssh2_pkt_addstring_start(ssh);
1476 ssh2_pkt_addstring_str(ssh, data);
1478 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1481 int i, n = (bignum_bitcount(b) + 7) / 8;
1482 p = snewn(n + 1, unsigned char);
1484 fatalbox("out of memory");
1486 for (i = 1; i <= n; i++)
1487 p[i] = bignum_byte(b, n - i);
1489 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1491 memmove(p, p + i, n + 1 - i);
1495 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1499 p = ssh2_mpint_fmt(b, &len);
1500 ssh2_pkt_addstring_start(ssh);
1501 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1506 * Construct an SSH2 final-form packet: compress it, encrypt it,
1507 * put the MAC on it. Final packet, ready to be sent, is stored in
1508 * ssh->pktout.data. Total length is returned.
1510 static int ssh2_pkt_construct(Ssh ssh)
1512 int cipherblk, maclen, padding, i;
1515 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1516 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1517 ssh->pktout.data + 6, ssh->pktout.length - 6);
1520 * Compress packet payload.
1523 unsigned char *newpayload;
1526 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1527 ssh->pktout.length - 5,
1528 &newpayload, &newlen)) {
1529 ssh->pktout.length = 5;
1530 ssh2_pkt_adddata(ssh, newpayload, newlen);
1536 * Add padding. At least four bytes, and must also bring total
1537 * length (minus MAC) up to a multiple of the block size.
1539 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1540 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1543 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1544 maclen = ssh->csmac ? ssh->csmac->len : 0;
1545 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1546 ssh->pktout.data[4] = padding;
1547 for (i = 0; i < padding; i++)
1548 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1549 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1551 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1552 ssh->pktout.length + padding,
1553 ssh->v2_outgoing_sequence);
1554 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1557 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1558 ssh->pktout.data, ssh->pktout.length + padding);
1560 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1561 return ssh->pktout.length + padding + maclen;
1565 * Construct and send an SSH2 packet immediately.
1567 static void ssh2_pkt_send(Ssh ssh)
1571 len = ssh2_pkt_construct(ssh);
1572 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1573 if (backlog > SSH_MAX_BACKLOG)
1574 ssh_throttle_all(ssh, 1, backlog);
1578 * Construct an SSH2 packet and add it to a deferred data block.
1579 * Useful for sending multiple packets in a single sk_write() call,
1580 * to prevent a traffic-analysing listener from being able to work
1581 * out the length of any particular packet (such as the password
1584 * Note that because SSH2 sequence-numbers its packets, this can
1585 * NOT be used as an m4-style `defer' allowing packets to be
1586 * constructed in one order and sent in another.
1588 static void ssh2_pkt_defer(Ssh ssh)
1590 int len = ssh2_pkt_construct(ssh);
1591 if (ssh->deferred_len + len > ssh->deferred_size) {
1592 ssh->deferred_size = ssh->deferred_len + len + 128;
1593 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1597 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1598 ssh->deferred_len += len;
1602 * Send the whole deferred data block constructed by
1603 * ssh2_pkt_defer() or SSH1's defer_packet().
1605 static void ssh_pkt_defersend(Ssh ssh)
1608 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1610 ssh->deferred_len = ssh->deferred_size = 0;
1611 sfree(ssh->deferred_send_data);
1612 ssh->deferred_send_data = NULL;
1613 if (backlog > SSH_MAX_BACKLOG)
1614 ssh_throttle_all(ssh, 1, backlog);
1618 void bndebug(char *string, Bignum b)
1622 p = ssh2_mpint_fmt(b, &len);
1623 debug(("%s", string));
1624 for (i = 0; i < len; i++)
1625 debug((" %02x", p[i]));
1631 static void sha_mpint(SHA_State * s, Bignum b)
1635 p = ssh2_mpint_fmt(b, &len);
1636 sha_string(s, p, len);
1641 * SSH2 packet decode functions.
1643 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1645 unsigned long value;
1646 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1647 return 0; /* arrgh, no way to decline (FIXME?) */
1648 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1649 ssh->pktin.savedpos += 4;
1652 static int ssh2_pkt_getbool(Ssh ssh)
1654 unsigned long value;
1655 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1656 return 0; /* arrgh, no way to decline (FIXME?) */
1657 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1658 ssh->pktin.savedpos++;
1661 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1666 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1668 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1672 ssh->pktin.savedpos += 4;
1673 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1675 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1676 ssh->pktin.savedpos += *length;
1678 static Bignum ssh2_pkt_getmp(Ssh ssh)
1684 ssh2_pkt_getstring(ssh, &p, &length);
1688 bombout(("internal error: Can't handle negative mpints"));
1691 b = bignum_from_bytes((unsigned char *)p, length);
1696 * Helper function to add an SSH2 signature blob to a packet.
1697 * Expects to be shown the public key blob as well as the signature
1698 * blob. Normally works just like ssh2_pkt_addstring, but will
1699 * fiddle with the signature packet if necessary for
1700 * BUG_SSH2_RSA_PADDING.
1702 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1703 void *sigblob_v, int sigblob_len)
1705 unsigned char *pkblob = (unsigned char *)pkblob_v;
1706 unsigned char *sigblob = (unsigned char *)sigblob_v;
1708 /* dmemdump(pkblob, pkblob_len); */
1709 /* dmemdump(sigblob, sigblob_len); */
1712 * See if this is in fact an ssh-rsa signature and a buggy
1713 * server; otherwise we can just do this the easy way.
1715 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1716 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1717 int pos, len, siglen;
1720 * Find the byte length of the modulus.
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1725 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1726 pos += 4; /* find modulus itself */
1727 while (len > 0 && pkblob[pos] == 0)
1729 /* debug(("modulus length is %d\n", len)); */
1732 * Now find the signature integer.
1734 pos = 4+7; /* skip over "ssh-rsa" */
1735 siglen = GET_32BIT(sigblob+pos);
1736 /* debug(("signature length is %d\n", siglen)); */
1738 if (len != siglen) {
1739 unsigned char newlen[4];
1740 ssh2_pkt_addstring_start(ssh);
1741 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1742 /* dmemdump(sigblob, pos); */
1743 pos += 4; /* point to start of actual sig */
1744 PUT_32BIT(newlen, len);
1745 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1746 /* dmemdump(newlen, 4); */
1748 while (len-- > siglen) {
1749 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1750 /* dmemdump(newlen, 1); */
1752 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1753 /* dmemdump(sigblob+pos, siglen); */
1757 /* Otherwise fall through and do it the easy way. */
1760 ssh2_pkt_addstring_start(ssh);
1761 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1765 * Examine the remote side's version string and compare it against
1766 * a list of known buggy implementations.
1768 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1770 char *imp; /* pointer to implementation part */
1772 imp += strcspn(imp, "-");
1774 imp += strcspn(imp, "-");
1777 ssh->remote_bugs = 0;
1779 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1780 (ssh->cfg.sshbug_ignore1 == AUTO &&
1781 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1782 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1783 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1784 !strcmp(imp, "OSU_1.4alpha3")))) {
1786 * These versions don't support SSH1_MSG_IGNORE, so we have
1787 * to use a different defence against password length
1790 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1791 logevent("We believe remote version has SSH1 ignore bug");
1794 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1796 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1798 * These versions need a plain password sent; they can't
1799 * handle having a null and a random length of data after
1802 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1803 logevent("We believe remote version needs a plain SSH1 password");
1806 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1807 (ssh->cfg.sshbug_rsa1 == AUTO &&
1808 (!strcmp(imp, "Cisco-1.25")))) {
1810 * These versions apparently have no clue whatever about
1811 * RSA authentication and will panic and die if they see
1812 * an AUTH_RSA message.
1814 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1815 logevent("We believe remote version can't handle RSA authentication");
1818 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_hmac2 == AUTO &&
1820 !wc_match("* VShell", imp) &&
1821 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1822 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1823 wc_match("2.1 *", imp)))) {
1825 * These versions have the HMAC bug.
1827 ssh->remote_bugs |= BUG_SSH2_HMAC;
1828 logevent("We believe remote version has SSH2 HMAC bug");
1831 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1832 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1833 !wc_match("* VShell", imp) &&
1834 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1836 * These versions have the key-derivation bug (failing to
1837 * include the literal shared secret in the hashes that
1838 * generate the keys).
1840 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1841 logevent("We believe remote version has SSH2 key-derivation bug");
1844 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1845 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1846 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1847 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1849 * These versions have the SSH2 RSA padding bug.
1851 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1852 logevent("We believe remote version has SSH2 RSA padding bug");
1855 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1856 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1857 wc_match("OpenSSH_2.[0-2]*", imp))) {
1859 * These versions have the SSH2 session-ID bug in
1860 * public-key authentication.
1862 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1863 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1866 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1868 * User specified the SSH2 DH GEX bug.
1870 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1871 logevent("We believe remote version has SSH2 DH group exchange bug");
1875 static int do_ssh_init(Ssh ssh, unsigned char c)
1877 struct do_ssh_init_state {
1885 crState(do_ssh_init_state);
1887 crBegin(ssh->do_ssh_init_crstate);
1889 /* Search for the string "SSH-" in the input. */
1892 static const int transS[] = { 1, 2, 2, 1 };
1893 static const int transH[] = { 0, 0, 3, 0 };
1894 static const int transminus[] = { 0, 0, 0, -1 };
1896 s->i = transS[s->i];
1898 s->i = transH[s->i];
1900 s->i = transminus[s->i];
1905 crReturn(1); /* get another character */
1909 s->vstring = snewn(s->vstrsize, char);
1910 strcpy(s->vstring, "SSH-");
1914 crReturn(1); /* get another char */
1915 if (s->vslen >= s->vstrsize - 1) {
1917 s->vstring = sresize(s->vstring, s->vstrsize, char);
1919 s->vstring[s->vslen++] = c;
1922 s->version[s->i] = '\0';
1924 } else if (s->i < sizeof(s->version) - 1)
1925 s->version[s->i++] = c;
1926 } else if (c == '\012')
1930 ssh->agentfwd_enabled = FALSE;
1931 ssh->rdpkt2_state.incoming_sequence = 0;
1933 s->vstring[s->vslen] = 0;
1934 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1937 vlog = snewn(20 + s->vslen, char);
1938 sprintf(vlog, "Server version: %s", s->vstring);
1942 ssh_detect_bugs(ssh, s->vstring);
1945 * Decide which SSH protocol version to support.
1948 /* Anything strictly below "2.0" means protocol 1 is supported. */
1949 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1950 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1951 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1953 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1954 bombout(("SSH protocol version 1 required by user but not provided by server"));
1957 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1958 bombout(("SSH protocol version 2 required by user but not provided by server"));
1962 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1966 char verstring[80], vlog[100];
1967 sprintf(verstring, "SSH-2.0-%s", sshver);
1968 SHA_Init(&ssh->exhashbase);
1970 * Hash our version string and their version string.
1972 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1973 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1974 sprintf(vlog, "We claim version: %s", verstring);
1976 strcat(verstring, "\012");
1977 logevent("Using SSH protocol version 2");
1978 sk_write(ssh->s, verstring, strlen(verstring));
1979 ssh->protocol = ssh2_protocol;
1981 ssh->s_rdpkt = ssh2_rdpkt;
1986 char verstring[80], vlog[100];
1987 sprintf(verstring, "SSH-%s-%s",
1988 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1990 sprintf(vlog, "We claim version: %s", verstring);
1992 strcat(verstring, "\012");
1994 logevent("Using SSH protocol version 1");
1995 sk_write(ssh->s, verstring, strlen(verstring));
1996 ssh->protocol = ssh1_protocol;
1998 ssh->s_rdpkt = ssh1_rdpkt;
2000 update_specials_menu(ssh->frontend);
2001 ssh->state = SSH_STATE_BEFORE_SIZE;
2008 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2010 crBegin(ssh->ssh_gotdata_crstate);
2013 * To begin with, feed the characters one by one to the
2014 * protocol initialisation / selection function do_ssh_init().
2015 * When that returns 0, we're done with the initial greeting
2016 * exchange and can move on to packet discipline.
2019 int ret; /* need not be kept across crReturn */
2021 crReturnV; /* more data please */
2022 ret = do_ssh_init(ssh, *data);
2030 * We emerge from that loop when the initial negotiation is
2031 * over and we have selected an s_rdpkt function. Now pass
2032 * everything to s_rdpkt, and then pass the resulting packets
2033 * to the proper protocol handler.
2038 while (datalen > 0) {
2039 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2040 if (ssh->state == SSH_STATE_CLOSED) {
2043 ssh->protocol(ssh, NULL, 0, 1);
2044 if (ssh->state == SSH_STATE_CLOSED) {
2054 static void ssh_do_close(Ssh ssh)
2057 struct ssh_channel *c;
2059 ssh->state = SSH_STATE_CLOSED;
2065 * Now we must shut down any port and X forwardings going
2066 * through this connection.
2068 if (ssh->channels) {
2069 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2072 x11_close(c->u.x11.s);
2075 pfd_close(c->u.pfd.s);
2078 del234(ssh->channels, c);
2079 if (ssh->version == 2)
2080 bufchain_clear(&c->v.v2.outbuffer);
2086 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2089 Ssh ssh = (Ssh) plug;
2092 /* A socket error has occurred. */
2093 logevent(error_msg);
2094 connection_fatal(ssh->frontend, "%s", error_msg);
2096 /* Otherwise, the remote side closed the connection normally. */
2101 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2103 Ssh ssh = (Ssh) plug;
2104 ssh_gotdata(ssh, (unsigned char *)data, len);
2105 if (ssh->state == SSH_STATE_CLOSED) {
2112 static void ssh_sent(Plug plug, int bufsize)
2114 Ssh ssh = (Ssh) plug;
2116 * If the send backlog on the SSH socket itself clears, we
2117 * should unthrottle the whole world if it was throttled.
2119 if (bufsize < SSH_MAX_BACKLOG)
2120 ssh_throttle_all(ssh, 0, bufsize);
2124 * Connect to specified host and port.
2125 * Returns an error message, or NULL on success.
2126 * Also places the canonical host name into `realhost'. It must be
2127 * freed by the caller.
2129 static const char *connect_to_host(Ssh ssh, char *host, int port,
2130 char **realhost, int nodelay)
2132 static const struct plug_function_table fn_table = {
2142 ssh->savedhost = snewn(1 + strlen(host), char);
2143 if (!ssh->savedhost)
2144 fatalbox("Out of memory");
2145 strcpy(ssh->savedhost, host);
2148 port = 22; /* default ssh port */
2149 ssh->savedport = port;
2154 logeventf(ssh, "Looking up host \"%s\"", host);
2155 addr = name_lookup(host, port, realhost, &ssh->cfg);
2156 if ((err = sk_addr_error(addr)) != NULL) {
2166 sk_getaddr(addr, addrbuf, 100);
2167 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2169 ssh->fn = &fn_table;
2170 ssh->s = new_connection(addr, *realhost, port,
2171 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2172 if ((err = sk_socket_error(ssh->s)) != NULL) {
2181 * Throttle or unthrottle the SSH connection.
2183 static void ssh1_throttle(Ssh ssh, int adjust)
2185 int old_count = ssh->v1_throttle_count;
2186 ssh->v1_throttle_count += adjust;
2187 assert(ssh->v1_throttle_count >= 0);
2188 if (ssh->v1_throttle_count && !old_count) {
2189 sk_set_frozen(ssh->s, 1);
2190 } else if (!ssh->v1_throttle_count && old_count) {
2191 sk_set_frozen(ssh->s, 0);
2196 * Throttle or unthrottle _all_ local data streams (for when sends
2197 * on the SSH connection itself back up).
2199 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2202 struct ssh_channel *c;
2204 if (enable == ssh->throttled_all)
2206 ssh->throttled_all = enable;
2207 ssh->overall_bufsize = bufsize;
2210 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2212 case CHAN_MAINSESSION:
2214 * This is treated separately, outside the switch.
2218 x11_override_throttle(c->u.x11.s, enable);
2221 /* Agent channels require no buffer management. */
2224 pfd_override_throttle(c->u.pfd.s, enable);
2231 * Username and password input, abstracted off into routines
2232 * reusable in several places - even between SSH1 and SSH2.
2235 /* Set up a username or password input loop on a given buffer. */
2236 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2238 ssh->userpass_input_buffer = buffer;
2239 ssh->userpass_input_buflen = buflen;
2240 ssh->userpass_input_bufpos = 0;
2241 ssh->userpass_input_echo = echo;
2245 * Process some terminal data in the course of username/password
2246 * input. Returns >0 for success (line of input returned in
2247 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2248 * for inconclusive (keep waiting for more input please).
2250 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2255 switch (c = *in++) {
2258 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2259 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2264 if (ssh->userpass_input_bufpos > 0) {
2265 if (ssh->userpass_input_echo)
2266 c_write_str(ssh, "\b \b");
2267 ssh->userpass_input_bufpos--;
2272 while (ssh->userpass_input_bufpos > 0) {
2273 if (ssh->userpass_input_echo)
2274 c_write_str(ssh, "\b \b");
2275 ssh->userpass_input_bufpos--;
2284 * This simplistic check for printability is disabled
2285 * when we're doing password input, because some people
2286 * have control characters in their passwords.o
2288 if ((!ssh->userpass_input_echo ||
2289 (c >= ' ' && c <= '~') ||
2290 ((unsigned char) c >= 160))
2291 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2292 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2293 if (ssh->userpass_input_echo)
2294 c_write(ssh, &c, 1);
2302 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2304 Ssh ssh = (Ssh) sshv;
2306 ssh->agent_response = reply;
2307 ssh->agent_response_len = replylen;
2309 if (ssh->version == 1)
2310 do_ssh1_login(ssh, NULL, -1, 0);
2312 do_ssh2_authconn(ssh, NULL, -1, 0);
2315 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2317 struct ssh_channel *c = (struct ssh_channel *)cv;
2319 void *sentreply = reply;
2322 /* Fake SSH_AGENT_FAILURE. */
2323 sentreply = "\0\0\0\1\5";
2326 if (ssh->version == 2) {
2327 ssh2_add_channel_data(c, sentreply, replylen);
2330 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2331 PKT_INT, c->remoteid,
2333 PKT_DATA, sentreply, replylen,
2341 * Handle the key exchange and user authentication phases.
2343 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2346 unsigned char cookie[8];
2347 struct RSAKey servkey, hostkey;
2348 struct MD5Context md5c;
2349 struct do_ssh1_login_state {
2351 unsigned char *rsabuf, *keystr1, *keystr2;
2352 unsigned long supported_ciphers_mask, supported_auths_mask;
2353 int tried_publickey, tried_agent;
2354 int tis_auth_refused, ccard_auth_refused;
2355 unsigned char session_id[16];
2358 void *publickey_blob;
2359 int publickey_bloblen;
2365 unsigned char request[5], *response, *p;
2374 crState(do_ssh1_login_state);
2376 crBegin(ssh->do_ssh1_login_crstate);
2381 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2382 bombout(("Public key packet not received"));
2386 logevent("Received public keys");
2388 memcpy(cookie, ssh->pktin.body, 8);
2390 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2391 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2394 * Log the host key fingerprint.
2398 logevent("Host key fingerprint is:");
2399 strcpy(logmsg, " ");
2400 hostkey.comment = NULL;
2401 rsa_fingerprint(logmsg + strlen(logmsg),
2402 sizeof(logmsg) - strlen(logmsg), &hostkey);
2406 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2407 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2408 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2410 ssh->v1_local_protoflags =
2411 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2412 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2415 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2416 MD5Update(&md5c, s->keystr1, servkey.bytes);
2417 MD5Update(&md5c, ssh->pktin.body, 8);
2418 MD5Final(s->session_id, &md5c);
2420 for (i = 0; i < 32; i++)
2421 ssh->session_key[i] = random_byte();
2423 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2425 s->rsabuf = snewn(s->len, unsigned char);
2427 fatalbox("Out of memory");
2430 * Verify the host key.
2434 * First format the key into a string.
2436 int len = rsastr_len(&hostkey);
2437 char fingerprint[100];
2438 char *keystr = snewn(len, char);
2440 fatalbox("Out of memory");
2441 rsastr_fmt(keystr, &hostkey);
2442 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2443 verify_ssh_host_key(ssh->frontend,
2444 ssh->savedhost, ssh->savedport, "rsa", keystr,
2449 for (i = 0; i < 32; i++) {
2450 s->rsabuf[i] = ssh->session_key[i];
2452 s->rsabuf[i] ^= s->session_id[i];
2455 if (hostkey.bytes > servkey.bytes) {
2456 rsaencrypt(s->rsabuf, 32, &servkey);
2457 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2459 rsaencrypt(s->rsabuf, 32, &hostkey);
2460 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2463 logevent("Encrypted session key");
2466 int cipher_chosen = 0, warn = 0;
2467 char *cipher_string = NULL;
2469 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2470 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2471 if (next_cipher == CIPHER_WARN) {
2472 /* If/when we choose a cipher, warn about it */
2474 } else if (next_cipher == CIPHER_AES) {
2475 /* XXX Probably don't need to mention this. */
2476 logevent("AES not supported in SSH1, skipping");
2478 switch (next_cipher) {
2479 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2480 cipher_string = "3DES"; break;
2481 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2482 cipher_string = "Blowfish"; break;
2483 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2484 cipher_string = "single-DES"; break;
2486 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2490 if (!cipher_chosen) {
2491 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2492 bombout(("Server violates SSH 1 protocol by not "
2493 "supporting 3DES encryption"));
2495 /* shouldn't happen */
2496 bombout(("No supported ciphers found"));
2500 /* Warn about chosen cipher if necessary. */
2502 askcipher(ssh->frontend, cipher_string, 0);
2505 switch (s->cipher_type) {
2506 case SSH_CIPHER_3DES:
2507 logevent("Using 3DES encryption");
2509 case SSH_CIPHER_DES:
2510 logevent("Using single-DES encryption");
2512 case SSH_CIPHER_BLOWFISH:
2513 logevent("Using Blowfish encryption");
2517 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2518 PKT_CHAR, s->cipher_type,
2519 PKT_DATA, cookie, 8,
2520 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2521 PKT_DATA, s->rsabuf, s->len,
2522 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2524 logevent("Trying to enable encryption...");
2528 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2529 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2531 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2532 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2533 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2535 ssh->crcda_ctx = crcda_make_context();
2536 logevent("Installing CRC compensation attack detector");
2538 if (servkey.modulus) {
2539 sfree(servkey.modulus);
2540 servkey.modulus = NULL;
2542 if (servkey.exponent) {
2543 sfree(servkey.exponent);
2544 servkey.exponent = NULL;
2546 if (hostkey.modulus) {
2547 sfree(hostkey.modulus);
2548 hostkey.modulus = NULL;
2550 if (hostkey.exponent) {
2551 sfree(hostkey.exponent);
2552 hostkey.exponent = NULL;
2556 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2557 bombout(("Encryption not successfully enabled"));
2561 logevent("Successfully started encryption");
2565 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2566 if (ssh_get_line && !ssh_getline_pw_only) {
2567 if (!ssh_get_line("login as: ",
2568 s->username, sizeof(s->username), FALSE)) {
2570 * get_line failed to get a username.
2573 logevent("No username provided. Abandoning session.");
2574 ssh_closing((Plug)ssh, NULL, 0, 0);
2578 int ret; /* need not be kept over crReturn */
2579 c_write_str(ssh, "login as: ");
2582 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2584 crWaitUntil(!ispkt);
2585 ret = process_userpass_input(ssh, in, inlen);
2589 c_write_str(ssh, "\r\n");
2592 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2593 s->username[sizeof(s->username)-1] = '\0';
2596 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2598 char userlog[22 + sizeof(s->username)];
2599 sprintf(userlog, "Sent username \"%s\"", s->username);
2601 if (flags & FLAG_INTERACTIVE &&
2602 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2603 strcat(userlog, "\r\n");
2604 c_write_str(ssh, userlog);
2611 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2612 /* We must not attempt PK auth. Pretend we've already tried it. */
2613 s->tried_publickey = s->tried_agent = 1;
2615 s->tried_publickey = s->tried_agent = 0;
2617 s->tis_auth_refused = s->ccard_auth_refused = 0;
2618 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2619 if (!filename_is_null(ssh->cfg.keyfile)) {
2620 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2621 &s->publickey_blob, &s->publickey_bloblen, NULL))
2622 s->publickey_blob = NULL;
2624 s->publickey_blob = NULL;
2626 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2627 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2629 if (agent_exists() && !s->tried_agent) {
2631 * Attempt RSA authentication using Pageant.
2637 logevent("Pageant is running. Requesting keys.");
2639 /* Request the keys held by the agent. */
2640 PUT_32BIT(s->request, 1);
2641 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2642 if (!agent_query(s->request, 5, &r, &s->responselen,
2643 ssh_agent_callback, ssh)) {
2647 bombout(("Unexpected data from server while waiting"
2648 " for agent response"));
2651 } while (ispkt || inlen > 0);
2652 r = ssh->agent_response;
2653 s->responselen = ssh->agent_response_len;
2655 s->response = (unsigned char *) r;
2656 if (s->response && s->responselen >= 5 &&
2657 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2658 s->p = s->response + 5;
2659 s->nkeys = GET_32BIT(s->p);
2663 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2666 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2669 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2672 if (s->publickey_blob &&
2673 !memcmp(s->p, s->publickey_blob,
2674 s->publickey_bloblen)) {
2675 logevent("This key matches configured key file");
2676 s->tried_publickey = 1;
2679 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2680 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2681 s->commentlen = GET_32BIT(s->p);
2683 s->commentp = (char *)s->p;
2684 s->p += s->commentlen;
2685 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2686 PKT_BIGNUM, s->key.modulus, PKT_END);
2688 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2689 logevent("Key refused");
2692 logevent("Received RSA challenge");
2693 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2695 char *agentreq, *q, *ret;
2698 len = 1 + 4; /* message type, bit count */
2699 len += ssh1_bignum_length(s->key.exponent);
2700 len += ssh1_bignum_length(s->key.modulus);
2701 len += ssh1_bignum_length(s->challenge);
2702 len += 16; /* session id */
2703 len += 4; /* response format */
2704 agentreq = snewn(4 + len, char);
2705 PUT_32BIT(agentreq, len);
2707 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2708 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2710 q += ssh1_write_bignum(q, s->key.exponent);
2711 q += ssh1_write_bignum(q, s->key.modulus);
2712 q += ssh1_write_bignum(q, s->challenge);
2713 memcpy(q, s->session_id, 16);
2715 PUT_32BIT(q, 1); /* response format */
2716 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2717 ssh_agent_callback, ssh)) {
2722 bombout(("Unexpected data from server"
2723 " while waiting for agent"
2727 } while (ispkt || inlen > 0);
2728 vret = ssh->agent_response;
2729 retlen = ssh->agent_response_len;
2734 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2735 logevent("Sending Pageant's response");
2736 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2737 PKT_DATA, ret + 5, 16,
2741 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2743 ("Pageant's response accepted");
2744 if (flags & FLAG_VERBOSE) {
2745 c_write_str(ssh, "Authenticated using"
2747 c_write(ssh, s->commentp,
2749 c_write_str(ssh, "\" from agent\r\n");
2754 ("Pageant's response not accepted");
2757 ("Pageant failed to answer challenge");
2761 logevent("No reply received from Pageant");
2764 freebn(s->key.exponent);
2765 freebn(s->key.modulus);
2766 freebn(s->challenge);
2775 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2776 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2778 if (ssh->cfg.try_tis_auth &&
2779 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2780 !s->tis_auth_refused) {
2781 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2782 logevent("Requested TIS authentication");
2783 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2785 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2786 logevent("TIS authentication declined");
2787 if (flags & FLAG_INTERACTIVE)
2788 c_write_str(ssh, "TIS authentication refused.\r\n");
2789 s->tis_auth_refused = 1;
2792 int challengelen = GET_32BIT(ssh->pktin.body);
2793 logevent("Received TIS challenge");
2794 if (challengelen > sizeof(s->prompt) - 1)
2795 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2796 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2797 /* Prompt heuristic comes from OpenSSH */
2798 strncpy(s->prompt + challengelen,
2799 memchr(s->prompt, '\n', challengelen) ?
2800 "": "\r\nResponse: ",
2801 (sizeof s->prompt) - challengelen);
2802 s->prompt[(sizeof s->prompt) - 1] = '\0';
2805 if (ssh->cfg.try_tis_auth &&
2806 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2807 !s->ccard_auth_refused) {
2808 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2809 logevent("Requested CryptoCard authentication");
2810 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2812 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2813 logevent("CryptoCard authentication declined");
2814 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2815 s->ccard_auth_refused = 1;
2818 int challengelen = GET_32BIT(ssh->pktin.body);
2819 logevent("Received CryptoCard challenge");
2820 if (challengelen > sizeof(s->prompt) - 1)
2821 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2822 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2823 strncpy(s->prompt + challengelen,
2824 memchr(s->prompt, '\n', challengelen) ?
2825 "" : "\r\nResponse: ",
2826 sizeof(s->prompt) - challengelen);
2827 s->prompt[sizeof(s->prompt) - 1] = '\0';
2830 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2831 sprintf(s->prompt, "%.90s@%.90s's password: ",
2832 s->username, ssh->savedhost);
2834 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2835 char *comment = NULL;
2838 if (flags & FLAG_VERBOSE)
2839 c_write_str(ssh, "Trying public key authentication.\r\n");
2840 logeventf(ssh, "Trying public key \"%s\"",
2841 filename_to_str(&ssh->cfg.keyfile));
2842 type = key_type(&ssh->cfg.keyfile);
2843 if (type != SSH_KEYTYPE_SSH1) {
2844 sprintf(msgbuf, "Key is of wrong type (%s)",
2845 key_type_to_str(type));
2847 c_write_str(ssh, msgbuf);
2848 c_write_str(ssh, "\r\n");
2849 s->tried_publickey = 1;
2852 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2853 if (flags & FLAG_VERBOSE)
2854 c_write_str(ssh, "No passphrase required.\r\n");
2857 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2862 * Show password prompt, having first obtained it via a TIS
2863 * or CryptoCard exchange if we're doing TIS or CryptoCard
2867 if (!ssh_get_line(s->prompt, s->password,
2868 sizeof(s->password), TRUE)) {
2870 * get_line failed to get a password (for example
2871 * because one was supplied on the command line
2872 * which has already failed to work). Terminate.
2874 send_packet(ssh, SSH1_MSG_DISCONNECT,
2875 PKT_STR, "No more passwords available to try",
2877 logevent("Unable to authenticate");
2878 connection_fatal(ssh->frontend, "Unable to authenticate");
2879 ssh_closing((Plug)ssh, NULL, 0, 0);
2883 /* Prompt may have come from server. We've munged it a bit, so
2884 * we know it to be zero-terminated at least once. */
2885 int ret; /* need not be saved over crReturn */
2886 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2889 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2891 crWaitUntil(!ispkt);
2892 ret = process_userpass_input(ssh, in, inlen);
2896 c_write_str(ssh, "\r\n");
2900 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2902 * Try public key authentication with the specified
2905 s->tried_publickey = 1;
2908 const char *error = NULL;
2909 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
2912 c_write_str(ssh, "Couldn't load private key from ");
2913 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2914 c_write_str(ssh, " (");
2915 c_write_str(ssh, error);
2916 c_write_str(ssh, ").\r\n");
2917 continue; /* go and try password */
2920 c_write_str(ssh, "Wrong passphrase.\r\n");
2921 s->tried_publickey = 0;
2922 continue; /* try again */
2927 * Send a public key attempt.
2929 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2930 PKT_BIGNUM, s->key.modulus, PKT_END);
2933 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2934 c_write_str(ssh, "Server refused our public key.\r\n");
2935 continue; /* go and try password */
2937 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2938 bombout(("Bizarre response to offer of public key"));
2944 unsigned char buffer[32];
2945 Bignum challenge, response;
2947 ssh1_read_bignum(ssh->pktin.body, &challenge);
2948 response = rsadecrypt(challenge, &s->key);
2949 freebn(s->key.private_exponent);/* burn the evidence */
2951 for (i = 0; i < 32; i++) {
2952 buffer[i] = bignum_byte(response, 31 - i);
2956 MD5Update(&md5c, buffer, 32);
2957 MD5Update(&md5c, s->session_id, 16);
2958 MD5Final(buffer, &md5c);
2960 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2961 PKT_DATA, buffer, 16, PKT_END);
2968 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2969 if (flags & FLAG_VERBOSE)
2970 c_write_str(ssh, "Failed to authenticate with"
2971 " our public key.\r\n");
2972 continue; /* go and try password */
2973 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2974 bombout(("Bizarre response to RSA authentication response"));
2978 break; /* we're through! */
2980 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2982 * Defence against traffic analysis: we send a
2983 * whole bunch of packets containing strings of
2984 * different lengths. One of these strings is the
2985 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2986 * The others are all random data in
2987 * SSH1_MSG_IGNORE packets. This way a passive
2988 * listener can't tell which is the password, and
2989 * hence can't deduce the password length.
2991 * Anybody with a password length greater than 16
2992 * bytes is going to have enough entropy in their
2993 * password that a listener won't find it _that_
2994 * much help to know how long it is. So what we'll
2997 * - if password length < 16, we send 15 packets
2998 * containing string lengths 1 through 15
3000 * - otherwise, we let N be the nearest multiple
3001 * of 8 below the password length, and send 8
3002 * packets containing string lengths N through
3003 * N+7. This won't obscure the order of
3004 * magnitude of the password length, but it will
3005 * introduce a bit of extra uncertainty.
3007 * A few servers (the old 1.2.18 through 1.2.22)
3008 * can't deal with SSH1_MSG_IGNORE. For these
3009 * servers, we need an alternative defence. We make
3010 * use of the fact that the password is interpreted
3011 * as a C string: so we can append a NUL, then some
3014 * One server (a Cisco one) can deal with neither
3015 * SSH1_MSG_IGNORE _nor_ a padded password string.
3016 * For this server we are left with no defences
3017 * against password length sniffing.
3019 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3021 * The server can deal with SSH1_MSG_IGNORE, so
3022 * we can use the primary defence.
3024 int bottom, top, pwlen, i;
3027 pwlen = strlen(s->password);
3029 bottom = 0; /* zero length passwords are OK! :-) */
3032 bottom = pwlen & ~7;
3036 assert(pwlen >= bottom && pwlen <= top);
3038 randomstr = snewn(top + 1, char);
3040 for (i = bottom; i <= top; i++) {
3042 defer_packet(ssh, s->pwpkt_type,
3043 PKT_STR, s->password, PKT_END);
3045 for (j = 0; j < i; j++) {
3047 randomstr[j] = random_byte();
3048 } while (randomstr[j] == '\0');
3050 randomstr[i] = '\0';
3051 defer_packet(ssh, SSH1_MSG_IGNORE,
3052 PKT_STR, randomstr, PKT_END);
3055 logevent("Sending password with camouflage packets");
3056 ssh_pkt_defersend(ssh);
3059 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3061 * The server can't deal with SSH1_MSG_IGNORE
3062 * but can deal with padded passwords, so we
3063 * can use the secondary defence.
3069 len = strlen(s->password);
3070 if (len < sizeof(string)) {
3072 strcpy(string, s->password);
3073 len++; /* cover the zero byte */
3074 while (len < sizeof(string)) {
3075 string[len++] = (char) random_byte();
3080 logevent("Sending length-padded password");
3081 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3082 PKT_DATA, ss, len, PKT_END);
3085 * The server has _both_
3086 * BUG_CHOKES_ON_SSH1_IGNORE and
3087 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3088 * therefore nothing we can do.
3091 len = strlen(s->password);
3092 logevent("Sending unpadded password");
3093 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3094 PKT_DATA, s->password, len, PKT_END);
3097 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
3100 logevent("Sent password");
3101 memset(s->password, 0, strlen(s->password));
3103 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3104 if (flags & FLAG_VERBOSE)
3105 c_write_str(ssh, "Access denied\r\n");
3106 logevent("Authentication refused");
3107 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3108 bombout(("Strange packet received, type %d", ssh->pktin.type));
3113 logevent("Authentication successful");
3118 void sshfwd_close(struct ssh_channel *c)
3122 if (ssh->state != SSH_STATE_SESSION) {
3123 assert(ssh->state == SSH_STATE_CLOSED);
3127 if (c && !c->closes) {
3129 * If the channel's remoteid is -1, we have sent
3130 * CHANNEL_OPEN for this channel, but it hasn't even been
3131 * acknowledged by the server. So we must set a close flag
3132 * on it now, and then when the server acks the channel
3133 * open, we can close it then.
3135 if (((int)c->remoteid) != -1) {
3136 if (ssh->version == 1) {
3137 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3140 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3141 ssh2_pkt_adduint32(ssh, c->remoteid);
3145 c->closes = 1; /* sent MSG_CLOSE */
3146 if (c->type == CHAN_X11) {
3148 logevent("Forwarded X11 connection terminated");
3149 } else if (c->type == CHAN_SOCKDATA ||
3150 c->type == CHAN_SOCKDATA_DORMANT) {
3152 logevent("Forwarded port closed");
3157 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3161 if (ssh->state != SSH_STATE_SESSION) {
3162 assert(ssh->state == SSH_STATE_CLOSED);
3166 if (ssh->version == 1) {
3167 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3168 PKT_INT, c->remoteid,
3169 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3171 * In SSH1 we can return 0 here - implying that forwarded
3172 * connections are never individually throttled - because
3173 * the only circumstance that can cause throttling will be
3174 * the whole SSH connection backing up, in which case
3175 * _everything_ will be throttled as a whole.
3179 ssh2_add_channel_data(c, buf, len);
3180 return ssh2_try_send(c);
3184 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3188 if (ssh->state != SSH_STATE_SESSION) {
3189 assert(ssh->state == SSH_STATE_CLOSED);
3193 if (ssh->version == 1) {
3194 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3195 c->v.v1.throttling = 0;
3196 ssh1_throttle(ssh, -1);
3199 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3203 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3205 crBegin(ssh->ssh1_protocol_crstate);
3209 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3212 if (ssh->state == SSH_STATE_CLOSED)
3215 if (ssh->cfg.agentfwd && agent_exists()) {
3216 logevent("Requesting agent forwarding");
3217 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3221 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3222 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3223 bombout(("Protocol confusion"));
3225 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3226 logevent("Agent forwarding refused");
3228 logevent("Agent forwarding enabled");
3229 ssh->agentfwd_enabled = TRUE;
3233 if (ssh->cfg.x11_forward) {
3234 char proto[20], data[64];
3235 logevent("Requesting X11 forwarding");
3236 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3237 data, sizeof(data), ssh->cfg.x11_auth);
3238 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3239 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3240 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3241 PKT_STR, proto, PKT_STR, data,
3242 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3245 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3246 PKT_STR, proto, PKT_STR, data, PKT_END);
3251 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3252 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3253 bombout(("Protocol confusion"));
3255 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3256 logevent("X11 forwarding refused");
3258 logevent("X11 forwarding enabled");
3259 ssh->X11_fwd_enabled = TRUE;
3266 int sport,dport,sserv,dserv;
3267 char sports[256], dports[256], saddr[256], host[256];
3269 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3270 /* Add port forwardings. */
3271 ssh->portfwd_strptr = ssh->cfg.portfwd;
3272 while (*ssh->portfwd_strptr) {
3273 type = *ssh->portfwd_strptr++;
3276 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3277 if (*ssh->portfwd_strptr == ':') {
3279 * We've seen a colon in the middle of the
3280 * source port number. This means that
3281 * everything we've seen until now is the
3282 * source _address_, so we'll move it into
3283 * saddr and start sports from the beginning
3286 ssh->portfwd_strptr++;
3288 strcpy(saddr, sports);
3291 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3295 if (*ssh->portfwd_strptr == '\t')
3296 ssh->portfwd_strptr++;
3298 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3299 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3302 if (*ssh->portfwd_strptr == ':')
3303 ssh->portfwd_strptr++;
3305 while (*ssh->portfwd_strptr) {
3306 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3309 ssh->portfwd_strptr++;
3310 dport = atoi(dports);
3314 dport = net_service_lookup(dports);
3316 logeventf(ssh, "Service lookup failed for"
3317 " destination port \"%s\"", dports);
3321 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3323 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3325 sport = atoi(sports);
3329 sport = net_service_lookup(sports);
3331 logeventf(ssh, "Service lookup failed for source"
3332 " port \"%s\"", sports);
3335 if (sport && dport) {
3337 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3338 sport, ssh, &ssh->cfg);
3339 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3340 " forwarding to %s:%.*s%.*s%d%.*s",
3341 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3342 (int)(*saddr?1:0), ":",
3343 (int)(sserv ? strlen(sports) : 0), sports,
3344 sserv, "(", sport, sserv, ")",
3346 (int)(dserv ? strlen(dports) : 0), dports,
3347 dserv, "(", dport, dserv, ")");
3348 } else if (type == 'D') {
3349 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3350 sport, ssh, &ssh->cfg);
3351 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3352 " doing SOCKS dynamic forwarding",
3353 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3354 (int)(*saddr?1:0), ":",
3355 (int)(sserv ? strlen(sports) : 0), sports,
3356 sserv, "(", sport, sserv, ")");
3358 struct ssh_rportfwd *pf;
3359 pf = snew(struct ssh_rportfwd);
3360 strcpy(pf->dhost, host);
3364 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3367 if (add234(ssh->rportfwds, pf) != pf) {
3369 "Duplicate remote port forwarding to %s:%d",
3373 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3374 " forward to %s:%.*s%.*s%d%.*s",
3375 (int)(sserv ? strlen(sports) : 0), sports,
3376 sserv, "(", sport, sserv, ")",
3378 (int)(dserv ? strlen(dports) : 0), dports,
3379 dserv, "(", dport, dserv, ")");
3380 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3388 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3389 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3390 bombout(("Protocol confusion"));
3392 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3393 c_write_str(ssh, "Server refused port"
3396 logevent("Remote port forwarding enabled");
3403 if (!ssh->cfg.nopty) {
3404 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3405 PKT_STR, ssh->cfg.termtype,
3406 PKT_INT, ssh->term_height,
3407 PKT_INT, ssh->term_width,
3408 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3409 ssh->state = SSH_STATE_INTERMED;
3413 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3414 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3415 bombout(("Protocol confusion"));
3417 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3418 c_write_str(ssh, "Server refused to allocate pty\r\n");
3419 ssh->editing = ssh->echoing = 1;
3421 logevent("Allocated pty");
3423 ssh->editing = ssh->echoing = 1;
3426 if (ssh->cfg.compression) {
3427 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3431 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3432 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3433 bombout(("Protocol confusion"));
3435 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3436 c_write_str(ssh, "Server refused to compress\r\n");
3438 logevent("Started compression");
3439 ssh->v1_compressing = TRUE;
3440 ssh->cs_comp_ctx = zlib_compress_init();
3441 logevent("Initialised zlib (RFC1950) compression");
3442 ssh->sc_comp_ctx = zlib_decompress_init();
3443 logevent("Initialised zlib (RFC1950) decompression");
3447 * Start the shell or command.
3449 * Special case: if the first-choice command is an SSH2
3450 * subsystem (hence not usable here) and the second choice
3451 * exists, we fall straight back to that.
3454 char *cmd = ssh->cfg.remote_cmd_ptr;
3456 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3457 cmd = ssh->cfg.remote_cmd_ptr2;
3458 ssh->fallback_cmd = TRUE;
3461 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3463 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3464 logevent("Started session");
3467 ssh->state = SSH_STATE_SESSION;
3468 if (ssh->size_needed)
3469 ssh_size(ssh, ssh->term_width, ssh->term_height);
3470 if (ssh->eof_needed)
3471 ssh_special(ssh, TS_EOF);
3474 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3476 ssh->channels = newtree234(ssh_channelcmp);
3480 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3481 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3482 long len = GET_32BIT(ssh->pktin.body);
3484 from_backend(ssh->frontend,
3485 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3486 (char *)(ssh->pktin.body) + 4, len);
3487 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3488 ssh->v1_stdout_throttling = 1;
3489 ssh1_throttle(ssh, +1);
3491 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3492 ssh_closing((Plug)ssh, NULL, 0, 0);
3493 logevent("Received disconnect request");
3495 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3496 /* Remote side is trying to open a channel to talk to our
3497 * X-Server. Give them back a local channel number. */
3498 struct ssh_channel *c;
3500 logevent("Received X11 connect request");
3501 /* Refuse if X11 forwarding is disabled. */
3502 if (!ssh->X11_fwd_enabled) {
3503 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3504 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3505 logevent("Rejected X11 connect request");
3507 c = snew(struct ssh_channel);
3510 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3511 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3512 logevent("opening X11 forward connection failed");
3514 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3515 PKT_INT, GET_32BIT(ssh->pktin.body),
3519 ("opening X11 forward connection succeeded");
3520 c->remoteid = GET_32BIT(ssh->pktin.body);
3521 c->localid = alloc_channel_id(ssh);
3523 c->v.v1.throttling = 0;
3524 c->type = CHAN_X11; /* identify channel type */
3525 add234(ssh->channels, c);
3526 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3527 PKT_INT, c->remoteid, PKT_INT,
3528 c->localid, PKT_END);
3529 logevent("Opened X11 forward channel");
3532 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3533 /* Remote side is trying to open a channel to talk to our
3534 * agent. Give them back a local channel number. */
3535 struct ssh_channel *c;
3537 /* Refuse if agent forwarding is disabled. */
3538 if (!ssh->agentfwd_enabled) {
3539 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3540 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3542 c = snew(struct ssh_channel);
3544 c->remoteid = GET_32BIT(ssh->pktin.body);
3545 c->localid = alloc_channel_id(ssh);
3547 c->v.v1.throttling = 0;
3548 c->type = CHAN_AGENT; /* identify channel type */
3549 c->u.a.lensofar = 0;
3550 add234(ssh->channels, c);
3551 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3552 PKT_INT, c->remoteid, PKT_INT, c->localid,
3555 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3556 /* Remote side is trying to open a channel to talk to a
3557 * forwarded port. Give them back a local channel number. */
3558 struct ssh_channel *c;
3559 struct ssh_rportfwd pf;
3561 char host[256], buf[1024];
3564 c = snew(struct ssh_channel);
3567 hostsize = GET_32BIT(ssh->pktin.body+4);
3568 for (h = host, p = (char *)(ssh->pktin.body+8);
3569 hostsize != 0; hostsize--) {
3570 if (h+1 < host+sizeof(host))
3575 port = GET_32BIT(p);
3577 strcpy(pf.dhost, host);
3580 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3581 sprintf(buf, "Rejected remote port open request for %s:%d",
3584 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3585 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3587 sprintf(buf, "Received remote port open request for %s:%d",
3590 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3593 sprintf(buf, "Port open failed: %s", e);
3596 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3597 PKT_INT, GET_32BIT(ssh->pktin.body),
3600 c->remoteid = GET_32BIT(ssh->pktin.body);
3601 c->localid = alloc_channel_id(ssh);
3603 c->v.v1.throttling = 0;
3604 c->type = CHAN_SOCKDATA; /* identify channel type */
3605 add234(ssh->channels, c);
3606 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3607 PKT_INT, c->remoteid, PKT_INT,
3608 c->localid, PKT_END);
3609 logevent("Forwarded port opened successfully");
3613 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3614 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3615 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3616 struct ssh_channel *c;
3618 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3619 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3620 c->remoteid = localid;
3621 c->type = CHAN_SOCKDATA;
3622 c->v.v1.throttling = 0;
3623 pfd_confirm(c->u.pfd.s);
3626 if (c && c->closes) {
3628 * We have a pending close on this channel,
3629 * which we decided on before the server acked
3630 * the channel open. So now we know the
3631 * remoteid, we can close it again.
3633 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3634 PKT_INT, c->remoteid, PKT_END);
3637 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3638 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3639 struct ssh_channel *c;
3641 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3642 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3643 logevent("Forwarded connection refused by server");
3644 pfd_close(c->u.pfd.s);
3645 del234(ssh->channels, c);
3649 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3650 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3651 /* Remote side closes a channel. */
3652 unsigned i = GET_32BIT(ssh->pktin.body);
3653 struct ssh_channel *c;
3654 c = find234(ssh->channels, &i, ssh_channelfind);
3655 if (c && ((int)c->remoteid) != -1) {
3658 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3660 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3661 logevent("Forwarded X11 connection terminated");
3662 assert(c->u.x11.s != NULL);
3663 x11_close(c->u.x11.s);
3666 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3667 logevent("Forwarded port closed");
3668 assert(c->u.pfd.s != NULL);
3669 pfd_close(c->u.pfd.s);
3673 c->closes |= (closetype << 2); /* seen this message */
3674 if (!(c->closes & closetype)) {
3675 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3677 c->closes |= closetype; /* sent it too */
3680 if (c->closes == 15) {
3681 del234(ssh->channels, c);
3685 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3686 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3687 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3691 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3692 /* Data sent down one of our channels. */
3693 int i = GET_32BIT(ssh->pktin.body);
3694 int len = GET_32BIT(ssh->pktin.body + 4);
3695 unsigned char *p = ssh->pktin.body + 8;
3696 struct ssh_channel *c;
3697 c = find234(ssh->channels, &i, ssh_channelfind);
3702 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3705 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3708 /* Data for an agent message. Buffer it. */
3710 if (c->u.a.lensofar < 4) {
3711 int l = min(4 - c->u.a.lensofar, len);
3712 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3716 c->u.a.lensofar += l;
3718 if (c->u.a.lensofar == 4) {
3720 4 + GET_32BIT(c->u.a.msglen);
3721 c->u.a.message = snewn(c->u.a.totallen,
3723 memcpy(c->u.a.message, c->u.a.msglen, 4);
3725 if (c->u.a.lensofar >= 4 && len > 0) {
3727 min(c->u.a.totallen - c->u.a.lensofar,
3729 memcpy(c->u.a.message + c->u.a.lensofar, p,
3733 c->u.a.lensofar += l;
3735 if (c->u.a.lensofar == c->u.a.totallen) {
3738 if (agent_query(c->u.a.message,
3741 ssh_agentf_callback, c))
3742 ssh_agentf_callback(c, reply, replylen);
3743 sfree(c->u.a.message);
3744 c->u.a.lensofar = 0;
3747 bufsize = 0; /* agent channels never back up */
3750 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3751 c->v.v1.throttling = 1;
3752 ssh1_throttle(ssh, +1);
3755 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3756 /* may be from EXEC_SHELL on some servers */
3757 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3758 /* may be from EXEC_SHELL on some servers
3759 * if no pty is available or in other odd cases. Ignore */
3760 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3762 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3763 sprintf(buf, "Server sent command exit status %d",
3766 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3768 * In case `helpful' firewalls or proxies tack
3769 * extra human-readable text on the end of the
3770 * session which we might mistake for another
3771 * encrypted packet, we close the session once
3772 * we've sent EXIT_CONFIRMATION.
3774 ssh_closing((Plug)ssh, NULL, 0, 0);
3777 bombout(("Strange packet received: type %d", ssh->pktin.type));
3782 int len = min(inlen, 512);
3783 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3784 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3795 * Utility routine for decoding comma-separated strings in KEXINIT.
3797 static int in_commasep_string(char *needle, char *haystack, int haylen)
3800 if (!needle || !haystack) /* protect against null pointers */
3802 needlen = strlen(needle);
3805 * Is it at the start of the string?
3807 if (haylen >= needlen && /* haystack is long enough */
3808 !memcmp(needle, haystack, needlen) && /* initial match */
3809 (haylen == needlen || haystack[needlen] == ',')
3810 /* either , or EOS follows */
3814 * If not, search for the next comma and resume after that.
3815 * If no comma found, terminate.
3817 while (haylen > 0 && *haystack != ',')
3818 haylen--, haystack++;
3821 haylen--, haystack++; /* skip over comma itself */
3826 * SSH2 key creation method.
3828 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3829 unsigned char *sessid, char chr,
3830 unsigned char *keyspace)
3833 /* First 20 bytes. */
3835 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3837 SHA_Bytes(&s, H, 20);
3838 SHA_Bytes(&s, &chr, 1);
3839 SHA_Bytes(&s, sessid, 20);
3840 SHA_Final(&s, keyspace);
3841 /* Next 20 bytes. */
3843 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3845 SHA_Bytes(&s, H, 20);
3846 SHA_Bytes(&s, keyspace, 20);
3847 SHA_Final(&s, keyspace + 20);
3851 * Handle the SSH2 transport layer.
3853 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3855 struct do_ssh2_transport_state {
3856 int nbits, pbits, warn;
3857 Bignum p, g, e, f, K;
3858 int kex_init_value, kex_reply_value;
3859 const struct ssh_mac **maclist;
3861 const struct ssh2_cipher *cscipher_tobe;
3862 const struct ssh2_cipher *sccipher_tobe;
3863 const struct ssh_mac *csmac_tobe;
3864 const struct ssh_mac *scmac_tobe;
3865 const struct ssh_compress *cscomp_tobe;
3866 const struct ssh_compress *sccomp_tobe;
3867 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3868 int hostkeylen, siglen;
3869 void *hkey; /* actual host key */
3870 unsigned char exchange_hash[20];
3871 int n_preferred_ciphers;
3872 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3873 const struct ssh_compress *preferred_comp;
3876 crState(do_ssh2_transport_state);
3878 crBegin(ssh->do_ssh2_transport_crstate);
3880 s->cscipher_tobe = s->sccipher_tobe = NULL;
3881 s->csmac_tobe = s->scmac_tobe = NULL;
3882 s->cscomp_tobe = s->sccomp_tobe = NULL;
3890 * Set up the preferred ciphers. (NULL => warn below here)
3892 s->n_preferred_ciphers = 0;
3893 for (i = 0; i < CIPHER_MAX; i++) {
3894 switch (ssh->cfg.ssh_cipherlist[i]) {
3895 case CIPHER_BLOWFISH:
3896 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3899 if (ssh->cfg.ssh2_des_cbc) {
3900 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3904 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3907 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3910 /* Flag for later. Don't bother if it's the last in
3912 if (i < CIPHER_MAX - 1) {
3913 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3921 * Set up preferred compression.
3923 if (ssh->cfg.compression)
3924 s->preferred_comp = &ssh_zlib;
3926 s->preferred_comp = &ssh_comp_none;
3929 * Be prepared to work around the buggy MAC problem.
3931 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3932 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3934 s->maclist = macs, s->nmacs = lenof(macs);
3938 int i, j, cipherstr_started;
3941 * Construct and send our key exchange packet.
3943 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3944 for (i = 0; i < 16; i++)
3945 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3946 /* List key exchange algorithms. */
3947 ssh2_pkt_addstring_start(ssh);
3948 for (i = 0; i < lenof(kex_algs); i++) {
3949 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3950 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3952 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3953 if (i < lenof(kex_algs) - 1)
3954 ssh2_pkt_addstring_str(ssh, ",");
3956 /* List server host key algorithms. */
3957 ssh2_pkt_addstring_start(ssh);
3958 for (i = 0; i < lenof(hostkey_algs); i++) {
3959 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3960 if (i < lenof(hostkey_algs) - 1)
3961 ssh2_pkt_addstring_str(ssh, ",");
3963 /* List client->server encryption algorithms. */
3964 ssh2_pkt_addstring_start(ssh);
3965 cipherstr_started = 0;
3966 for (i = 0; i < s->n_preferred_ciphers; i++) {
3967 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3968 if (!c) continue; /* warning flag */
3969 for (j = 0; j < c->nciphers; j++) {
3970 if (cipherstr_started)
3971 ssh2_pkt_addstring_str(ssh, ",");
3972 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3973 cipherstr_started = 1;
3976 /* List server->client encryption algorithms. */
3977 ssh2_pkt_addstring_start(ssh);
3978 cipherstr_started = 0;
3979 for (i = 0; i < s->n_preferred_ciphers; i++) {
3980 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3981 if (!c) continue; /* warning flag */
3982 for (j = 0; j < c->nciphers; j++) {
3983 if (cipherstr_started)
3984 ssh2_pkt_addstring_str(ssh, ",");
3985 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3986 cipherstr_started = 1;
3989 /* List client->server MAC algorithms. */
3990 ssh2_pkt_addstring_start(ssh);
3991 for (i = 0; i < s->nmacs; i++) {
3992 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3993 if (i < s->nmacs - 1)
3994 ssh2_pkt_addstring_str(ssh, ",");
3996 /* List server->client MAC algorithms. */
3997 ssh2_pkt_addstring_start(ssh);
3998 for (i = 0; i < s->nmacs; i++) {
3999 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4000 if (i < s->nmacs - 1)
4001 ssh2_pkt_addstring_str(ssh, ",");
4003 /* List client->server compression algorithms. */
4004 ssh2_pkt_addstring_start(ssh);
4005 for (i = 0; i < lenof(compressions) + 1; i++) {
4006 const struct ssh_compress *c =
4007 i == 0 ? s->preferred_comp : compressions[i - 1];
4008 ssh2_pkt_addstring_str(ssh, c->name);
4009 if (i < lenof(compressions))
4010 ssh2_pkt_addstring_str(ssh, ",");
4012 /* List server->client compression algorithms. */
4013 ssh2_pkt_addstring_start(ssh);
4014 for (i = 0; i < lenof(compressions) + 1; i++) {
4015 const struct ssh_compress *c =
4016 i == 0 ? s->preferred_comp : compressions[i - 1];
4017 ssh2_pkt_addstring_str(ssh, c->name);
4018 if (i < lenof(compressions))
4019 ssh2_pkt_addstring_str(ssh, ",");
4021 /* List client->server languages. Empty list. */
4022 ssh2_pkt_addstring_start(ssh);
4023 /* List server->client languages. Empty list. */
4024 ssh2_pkt_addstring_start(ssh);
4025 /* First KEX packet does _not_ follow, because we're not that brave. */
4026 ssh2_pkt_addbool(ssh, FALSE);
4028 ssh2_pkt_adduint32(ssh, 0);
4031 ssh->exhash = ssh->exhashbase;
4032 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4038 if (ssh->pktin.length > 5)
4039 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4042 * Now examine the other side's KEXINIT to see what we're up
4049 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4050 bombout(("expected key exchange packet from server"));
4054 ssh->hostkey = NULL;
4055 s->cscipher_tobe = NULL;
4056 s->sccipher_tobe = NULL;
4057 s->csmac_tobe = NULL;
4058 s->scmac_tobe = NULL;
4059 s->cscomp_tobe = NULL;
4060 s->sccomp_tobe = NULL;
4061 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4062 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4063 for (i = 0; i < lenof(kex_algs); i++) {
4064 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4065 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4067 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4068 ssh->kex = kex_algs[i];
4072 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4073 for (i = 0; i < lenof(hostkey_algs); i++) {
4074 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4075 ssh->hostkey = hostkey_algs[i];
4079 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4081 for (i = 0; i < s->n_preferred_ciphers; i++) {
4082 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4086 for (j = 0; j < c->nciphers; j++) {
4087 if (in_commasep_string(c->list[j]->name, str, len)) {
4088 s->cscipher_tobe = c->list[j];
4093 if (s->cscipher_tobe) {
4095 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4099 if (!s->cscipher_tobe) {
4100 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4101 str ? str : "(null)"));
4105 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4107 for (i = 0; i < s->n_preferred_ciphers; i++) {
4108 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4112 for (j = 0; j < c->nciphers; j++) {
4113 if (in_commasep_string(c->list[j]->name, str, len)) {
4114 s->sccipher_tobe = c->list[j];
4119 if (s->sccipher_tobe) {
4121 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4125 if (!s->sccipher_tobe) {
4126 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4127 str ? str : "(null)"));
4131 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4132 for (i = 0; i < s->nmacs; i++) {
4133 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4134 s->csmac_tobe = s->maclist[i];
4138 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4139 for (i = 0; i < s->nmacs; i++) {
4140 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4141 s->scmac_tobe = s->maclist[i];
4145 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4146 for (i = 0; i < lenof(compressions) + 1; i++) {
4147 const struct ssh_compress *c =
4148 i == 0 ? s->preferred_comp : compressions[i - 1];
4149 if (in_commasep_string(c->name, str, len)) {
4154 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4155 for (i = 0; i < lenof(compressions) + 1; i++) {
4156 const struct ssh_compress *c =
4157 i == 0 ? s->preferred_comp : compressions[i - 1];
4158 if (in_commasep_string(c->name, str, len)) {
4166 * Work out the number of bits of key we will need from the key
4167 * exchange. We start with the maximum key length of either
4173 csbits = s->cscipher_tobe->keylen;
4174 scbits = s->sccipher_tobe->keylen;
4175 s->nbits = (csbits > scbits ? csbits : scbits);
4177 /* The keys only have 160-bit entropy, since they're based on
4178 * a SHA-1 hash. So cap the key size at 160 bits. */
4183 * If we're doing Diffie-Hellman group exchange, start by
4184 * requesting a group.
4186 if (ssh->kex == &ssh_diffiehellman_gex) {
4187 logevent("Doing Diffie-Hellman group exchange");
4188 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4190 * Work out how big a DH group we will need to allow that
4193 s->pbits = 512 << ((s->nbits - 1) / 64);
4194 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4195 ssh2_pkt_adduint32(ssh, s->pbits);
4199 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4200 bombout(("expected key exchange group packet from server"));
4203 s->p = ssh2_pkt_getmp(ssh);
4204 s->g = ssh2_pkt_getmp(ssh);
4205 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4206 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4207 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4209 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4210 ssh->kex_ctx = dh_setup_group1();
4211 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4212 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4215 logevent("Doing Diffie-Hellman key exchange");
4217 * Now generate and send e for Diffie-Hellman.
4219 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4220 ssh2_pkt_init(ssh, s->kex_init_value);
4221 ssh2_pkt_addmp(ssh, s->e);
4225 if (ssh->pktin.type != s->kex_reply_value) {
4226 bombout(("expected key exchange reply packet from server"));
4229 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4230 s->f = ssh2_pkt_getmp(ssh);
4231 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4233 s->K = dh_find_K(ssh->kex_ctx, s->f);
4235 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4236 if (ssh->kex == &ssh_diffiehellman_gex) {
4237 sha_uint32(&ssh->exhash, s->pbits);
4238 sha_mpint(&ssh->exhash, s->p);
4239 sha_mpint(&ssh->exhash, s->g);
4241 sha_mpint(&ssh->exhash, s->e);
4242 sha_mpint(&ssh->exhash, s->f);
4243 sha_mpint(&ssh->exhash, s->K);
4244 SHA_Final(&ssh->exhash, s->exchange_hash);
4246 dh_cleanup(ssh->kex_ctx);
4247 ssh->kex_ctx = NULL;
4250 debug(("Exchange hash is:\n"));
4251 dmemdump(s->exchange_hash, 20);
4254 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4256 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4257 (char *)s->exchange_hash, 20)) {
4258 bombout(("Server's host key did not match the signature supplied"));
4263 * Authenticate remote host: verify host key. (We've already
4264 * checked the signature of the exchange hash.)
4266 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4267 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4268 verify_ssh_host_key(ssh->frontend,
4269 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4270 s->keystr, s->fingerprint);
4271 if (s->first_kex) { /* don't bother logging this in rekeys */
4272 logevent("Host key fingerprint is:");
4273 logevent(s->fingerprint);
4275 sfree(s->fingerprint);
4277 ssh->hostkey->freekey(s->hkey);
4280 * Send SSH2_MSG_NEWKEYS.
4282 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4286 * Expect SSH2_MSG_NEWKEYS from server.
4289 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4290 bombout(("expected new-keys packet from server"));
4295 * Create and initialise session keys.
4297 if (ssh->cs_cipher_ctx)
4298 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4299 ssh->cscipher = s->cscipher_tobe;
4300 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4302 if (ssh->sc_cipher_ctx)
4303 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4304 ssh->sccipher = s->sccipher_tobe;
4305 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4307 if (ssh->cs_mac_ctx)
4308 ssh->csmac->free_context(ssh->cs_mac_ctx);
4309 ssh->csmac = s->csmac_tobe;
4310 ssh->cs_mac_ctx = ssh->csmac->make_context();
4312 if (ssh->sc_mac_ctx)
4313 ssh->scmac->free_context(ssh->sc_mac_ctx);
4314 ssh->scmac = s->scmac_tobe;
4315 ssh->sc_mac_ctx = ssh->scmac->make_context();
4317 if (ssh->cs_comp_ctx)
4318 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4319 ssh->cscomp = s->cscomp_tobe;
4320 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4322 if (ssh->sc_comp_ctx)
4323 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4324 ssh->sccomp = s->sccomp_tobe;
4325 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4328 * Set IVs after keys. Here we use the exchange hash from the
4329 * _first_ key exchange.
4332 unsigned char keyspace[40];
4334 memcpy(ssh->v2_session_id, s->exchange_hash,
4335 sizeof(s->exchange_hash));
4336 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4337 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4338 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4339 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4340 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4341 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4342 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4343 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4344 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4345 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4346 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4347 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4349 logeventf(ssh, "Initialised %.200s client->server encryption",
4350 ssh->cscipher->text_name);
4351 logeventf(ssh, "Initialised %.200s server->client encryption",
4352 ssh->sccipher->text_name);
4353 if (ssh->cscomp->text_name)
4354 logeventf(ssh, "Initialised %s compression",
4355 ssh->cscomp->text_name);
4356 if (ssh->sccomp->text_name)
4357 logeventf(ssh, "Initialised %s decompression",
4358 ssh->sccomp->text_name);
4361 if (ssh->kex == &ssh_diffiehellman_gex) {
4367 * If this is the first key exchange phase, we must pass the
4368 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4369 * wants to see it but because it will need time to initialise
4370 * itself before it sees an actual packet. In subsequent key
4371 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4372 * it would only confuse the layer above.
4374 if (!s->first_kex) {
4380 * Now we're encrypting. Begin returning 1 to the protocol main
4381 * function so that other things can run on top of the
4382 * transport. If we ever see a KEXINIT, we must go back to the
4385 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4388 logevent("Server initiated key re-exchange");
4389 goto begin_key_exchange;
4395 * Add data to an SSH2 channel output buffer.
4397 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4400 bufchain_add(&c->v.v2.outbuffer, buf, len);
4404 * Attempt to send data on an SSH2 channel.
4406 static int ssh2_try_send(struct ssh_channel *c)
4410 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4413 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4414 if ((unsigned)len > c->v.v2.remwindow)
4415 len = c->v.v2.remwindow;
4416 if ((unsigned)len > c->v.v2.remmaxpkt)
4417 len = c->v.v2.remmaxpkt;
4418 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4419 ssh2_pkt_adduint32(ssh, c->remoteid);
4420 ssh2_pkt_addstring_start(ssh);
4421 ssh2_pkt_addstring_data(ssh, data, len);
4423 bufchain_consume(&c->v.v2.outbuffer, len);
4424 c->v.v2.remwindow -= len;
4428 * After having sent as much data as we can, return the amount
4431 return bufchain_size(&c->v.v2.outbuffer);
4435 * Potentially enlarge the window on an SSH2 channel.
4437 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4442 * Never send WINDOW_ADJUST for a channel that the remote side
4443 * already thinks it's closed; there's no point, since it won't
4444 * be sending any more data anyway.
4449 if (newwin > c->v.v2.locwindow) {
4450 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4451 ssh2_pkt_adduint32(ssh, c->remoteid);
4452 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4454 c->v.v2.locwindow = newwin;
4459 * Handle the SSH2 userauth and connection layers.
4461 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4463 struct do_ssh2_authconn_state {
4465 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4467 AUTH_KEYBOARD_INTERACTIVE
4471 AUTH_TYPE_PUBLICKEY,
4472 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4473 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4475 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4476 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4478 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4479 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4480 int kbd_inter_running;
4482 int num_prompts, curr_prompt, echo;
4487 void *publickey_blob;
4488 int publickey_bloblen;
4489 unsigned char request[5], *response, *p;
4493 char *pkblob, *alg, *commentp;
4494 int pklen, alglen, commentlen;
4495 int siglen, retlen, len;
4496 char *q, *agentreq, *ret;
4499 crState(do_ssh2_authconn_state);
4501 crBegin(ssh->do_ssh2_authconn_crstate);
4504 * Request userauth protocol, and await a response to it.
4506 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4507 ssh2_pkt_addstring(ssh, "ssh-userauth");
4509 crWaitUntilV(ispkt);
4510 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4511 bombout(("Server refused user authentication protocol"));
4516 * We repeat this whole loop, including the username prompt,
4517 * until we manage a successful authentication. If the user
4518 * types the wrong _password_, they can be sent back to the
4519 * beginning to try another username, if this is configured on.
4520 * (If they specify a username in the config, they are never
4521 * asked, even if they do give a wrong password.)
4523 * I think this best serves the needs of
4525 * - the people who have no configuration, no keys, and just
4526 * want to try repeated (username,password) pairs until they
4527 * type both correctly
4529 * - people who have keys and configuration but occasionally
4530 * need to fall back to passwords
4532 * - people with a key held in Pageant, who might not have
4533 * logged in to a particular machine before; so they want to
4534 * type a username, and then _either_ their key will be
4535 * accepted, _or_ they will type a password. If they mistype
4536 * the username they will want to be able to get back and
4539 s->username[0] = '\0';
4540 s->got_username = FALSE;
4545 if (s->got_username && !ssh->cfg.change_username) {
4547 * We got a username last time round this loop, and
4548 * with change_username turned off we don't try to get
4551 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4552 if (ssh_get_line && !ssh_getline_pw_only) {
4553 if (!ssh_get_line("login as: ",
4554 s->username, sizeof(s->username), FALSE)) {
4556 * get_line failed to get a username.
4559 logevent("No username provided. Abandoning session.");
4560 ssh_closing((Plug)ssh, NULL, 0, 0);
4564 int ret; /* need not be saved across crReturn */
4565 c_write_str(ssh, "login as: ");
4567 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4569 crWaitUntilV(!ispkt);
4570 ret = process_userpass_input(ssh, in, inlen);
4574 c_write_str(ssh, "\r\n");
4576 s->username[strcspn(s->username, "\n\r")] = '\0';
4579 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4580 s->username[sizeof(s->username)-1] = '\0';
4581 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4582 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4583 c_write_str(ssh, stuff);
4587 s->got_username = TRUE;
4590 * Send an authentication request using method "none": (a)
4591 * just in case it succeeds, and (b) so that we know what
4592 * authentication methods we can usefully try next.
4594 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4596 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4597 ssh2_pkt_addstring(ssh, s->username);
4598 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4599 ssh2_pkt_addstring(ssh, "none"); /* method */
4601 s->type = AUTH_TYPE_NONE;
4603 s->we_are_in = FALSE;
4605 s->tried_pubkey_config = FALSE;
4606 s->tried_agent = FALSE;
4607 s->tried_keyb_inter = FALSE;
4608 s->kbd_inter_running = FALSE;
4609 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4610 if (!filename_is_null(ssh->cfg.keyfile)) {
4612 logeventf(ssh, "Reading private key file \"%.150s\"",
4613 filename_to_str(&ssh->cfg.keyfile));
4614 keytype = key_type(&ssh->cfg.keyfile);
4615 if (keytype == SSH_KEYTYPE_SSH2) {
4617 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4618 &s->publickey_bloblen, NULL);
4621 logeventf(ssh, "Unable to use this key file (%s)",
4622 key_type_to_str(keytype));
4623 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4625 filename_to_str(&ssh->cfg.keyfile),
4626 key_type_to_str(keytype));
4627 c_write_str(ssh, msgbuf);
4629 s->publickey_blob = NULL;
4632 s->publickey_blob = NULL;
4636 * Wait for the result of the last authentication request.
4639 crWaitUntilV(ispkt);
4640 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4644 * Don't show the banner if we're operating in
4645 * non-verbose non-interactive mode. (It's probably
4646 * a script, which means nobody will read the
4647 * banner _anyway_, and moreover the printing of
4648 * the banner will screw up processing on the
4649 * output of (say) plink.)
4651 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4652 ssh2_pkt_getstring(ssh, &banner, &size);
4654 c_write_untrusted(ssh, banner, size);
4656 crWaitUntilV(ispkt);
4658 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4659 logevent("Access granted");
4660 s->we_are_in = TRUE;
4664 if (s->kbd_inter_running &&
4665 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4667 * This is either a further set-of-prompts packet
4668 * in keyboard-interactive authentication, or it's
4669 * the same one and we came back here with `gotit'
4670 * set. In the former case, we must reset the
4671 * curr_prompt variable.
4675 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4676 bombout(("Strange packet received during authentication: type %d",
4684 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4685 * we can look at the string in it and know what we can
4686 * helpfully try next.
4688 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4691 ssh2_pkt_getstring(ssh, &methods, &methlen);
4692 s->kbd_inter_running = FALSE;
4693 if (!ssh2_pkt_getbool(ssh)) {
4695 * We have received an unequivocal Access
4696 * Denied. This can translate to a variety of
4699 * - if we'd just tried "none" authentication,
4700 * it's not worth printing anything at all
4702 * - if we'd just tried a public key _offer_,
4703 * the message should be "Server refused our
4704 * key" (or no message at all if the key
4705 * came from Pageant)
4707 * - if we'd just tried anything else, the
4708 * message really should be "Access denied".
4710 * Additionally, if we'd just tried password
4711 * authentication, we should break out of this
4712 * whole loop so as to go back to the username
4715 if (s->type == AUTH_TYPE_NONE) {
4717 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4718 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4719 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4720 c_write_str(ssh, "Server refused our key\r\n");
4721 logevent("Server refused public key");
4722 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4723 /* server declined keyboard-interactive; ignore */
4725 c_write_str(ssh, "Access denied\r\n");
4726 logevent("Access denied");
4727 if (s->type == AUTH_TYPE_PASSWORD) {
4728 s->we_are_in = FALSE;
4733 c_write_str(ssh, "Further authentication required\r\n");
4734 logevent("Further authentication required");
4738 in_commasep_string("publickey", methods, methlen);
4740 in_commasep_string("password", methods, methlen);
4741 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4742 in_commasep_string("keyboard-interactive", methods, methlen);
4746 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4750 * Most password/passphrase prompts will be
4751 * non-echoing, so we set this to 0 by default.
4752 * Exception is that some keyboard-interactive prompts
4753 * can be echoing, in which case we'll set this to 1.
4757 if (!s->method && s->can_pubkey &&
4758 agent_exists() && !s->tried_agent) {
4760 * Attempt public-key authentication using Pageant.
4765 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4766 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4768 s->tried_agent = TRUE;
4770 logevent("Pageant is running. Requesting keys.");
4772 /* Request the keys held by the agent. */
4773 PUT_32BIT(s->request, 1);
4774 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4775 if (!agent_query(s->request, 5, &r, &s->responselen,
4776 ssh_agent_callback, ssh)) {
4780 bombout(("Unexpected data from server while"
4781 " waiting for agent response"));
4784 } while (ispkt || inlen > 0);
4785 r = ssh->agent_response;
4786 s->responselen = ssh->agent_response_len;
4788 s->response = (unsigned char *) r;
4789 if (s->response && s->responselen >= 5 &&
4790 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4791 s->p = s->response + 5;
4792 s->nkeys = GET_32BIT(s->p);
4796 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4799 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4804 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4807 s->pklen = GET_32BIT(s->p);
4809 if (s->publickey_blob &&
4810 s->pklen == s->publickey_bloblen &&
4811 !memcmp(s->p, s->publickey_blob,
4812 s->publickey_bloblen)) {
4813 logevent("This key matches configured key file");
4814 s->tried_pubkey_config = 1;
4816 s->pkblob = (char *)s->p;
4818 s->alglen = GET_32BIT(s->pkblob);
4819 s->alg = s->pkblob + 4;
4820 s->commentlen = GET_32BIT(s->p);
4822 s->commentp = (char *)s->p;
4823 s->p += s->commentlen;
4824 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4825 ssh2_pkt_addstring(ssh, s->username);
4826 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4827 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4828 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4829 ssh2_pkt_addstring_start(ssh);
4830 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4831 ssh2_pkt_addstring_start(ssh);
4832 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4835 crWaitUntilV(ispkt);
4836 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4837 logevent("Key refused");
4841 if (flags & FLAG_VERBOSE) {
4842 c_write_str(ssh, "Authenticating with "
4844 c_write(ssh, s->commentp, s->commentlen);
4845 c_write_str(ssh, "\" from agent\r\n");
4849 * Server is willing to accept the key.
4850 * Construct a SIGN_REQUEST.
4852 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4853 ssh2_pkt_addstring(ssh, s->username);
4854 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4855 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4856 ssh2_pkt_addbool(ssh, TRUE);
4857 ssh2_pkt_addstring_start(ssh);
4858 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4859 ssh2_pkt_addstring_start(ssh);
4860 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4862 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4863 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4865 s->len = 1; /* message type */
4866 s->len += 4 + s->pklen; /* key blob */
4867 s->len += 4 + s->siglen; /* data to sign */
4868 s->len += 4; /* flags */
4869 s->agentreq = snewn(4 + s->len, char);
4870 PUT_32BIT(s->agentreq, s->len);
4871 s->q = s->agentreq + 4;
4872 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4873 PUT_32BIT(s->q, s->pklen);
4875 memcpy(s->q, s->pkblob, s->pklen);
4877 PUT_32BIT(s->q, s->siglen);
4879 /* Now the data to be signed... */
4880 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4881 PUT_32BIT(s->q, 20);
4884 memcpy(s->q, ssh->v2_session_id, 20);
4886 memcpy(s->q, ssh->pktout.data + 5,
4887 ssh->pktout.length - 5);
4888 s->q += ssh->pktout.length - 5;
4889 /* And finally the (zero) flags word. */
4891 if (!agent_query(s->agentreq, s->len + 4,
4893 ssh_agent_callback, ssh)) {
4897 bombout(("Unexpected data from server"
4898 " while waiting for agent"
4902 } while (ispkt || inlen > 0);
4903 vret = ssh->agent_response;
4904 s->retlen = ssh->agent_response_len;
4909 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4910 logevent("Sending Pageant's response");
4911 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4913 GET_32BIT(s->ret + 5));
4919 ("Pageant failed to answer challenge");
4930 if (!s->method && s->can_pubkey && s->publickey_blob
4931 && !s->tried_pubkey_config) {
4932 unsigned char *pub_blob;
4933 char *algorithm, *comment;
4936 s->tried_pubkey_config = TRUE;
4938 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4939 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4942 * Try the public key supplied in the configuration.
4944 * First, offer the public blob to see if the server is
4945 * willing to accept it.
4948 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4953 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4954 ssh2_pkt_addstring(ssh, s->username);
4955 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4956 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4957 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4958 ssh2_pkt_addstring(ssh, algorithm);
4959 ssh2_pkt_addstring_start(ssh);
4960 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4963 logevent("Offered public key"); /* FIXME */
4965 crWaitUntilV(ispkt);
4966 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4968 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4969 continue; /* key refused; give up on it */
4972 logevent("Offer of public key accepted");
4974 * Actually attempt a serious authentication using
4977 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4978 sprintf(s->pwprompt,
4979 "Passphrase for key \"%.100s\": ",
4985 c_write_str(ssh, "Authenticating with public key \"");
4986 c_write_str(ssh, comment);
4987 c_write_str(ssh, "\"\r\n");
4988 s->method = AUTH_PUBLICKEY_FILE;
4992 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4993 s->method = AUTH_KEYBOARD_INTERACTIVE;
4994 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4995 s->tried_keyb_inter = TRUE;
4997 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4998 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5000 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5001 ssh2_pkt_addstring(ssh, s->username);
5002 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5003 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5004 ssh2_pkt_addstring(ssh, ""); /* lang */
5005 ssh2_pkt_addstring(ssh, "");
5008 crWaitUntilV(ispkt);
5009 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5010 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5012 logevent("Keyboard-interactive authentication refused");
5013 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5017 s->kbd_inter_running = TRUE;
5021 if (s->kbd_inter_running) {
5022 s->method = AUTH_KEYBOARD_INTERACTIVE;
5023 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5024 s->tried_keyb_inter = TRUE;
5026 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5027 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5029 if (s->curr_prompt == 0) {
5031 * We've got a fresh USERAUTH_INFO_REQUEST.
5032 * Display header data, and start going through
5035 char *name, *inst, *lang;
5036 int name_len, inst_len, lang_len;
5038 ssh2_pkt_getstring(ssh, &name, &name_len);
5039 ssh2_pkt_getstring(ssh, &inst, &inst_len);
5040 ssh2_pkt_getstring(ssh, &lang, &lang_len);
5042 c_write_untrusted(ssh, name, name_len);
5043 c_write_str(ssh, "\r\n");
5046 c_write_untrusted(ssh, inst, inst_len);
5047 c_write_str(ssh, "\r\n");
5049 s->num_prompts = ssh2_pkt_getuint32(ssh);
5053 * If there are prompts remaining in the packet,
5054 * display one and get a response.
5056 if (s->curr_prompt < s->num_prompts) {
5060 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
5061 if (prompt_len > 0) {
5062 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
5063 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
5064 prompt_len : sizeof(s->pwprompt)-1] = '\0';
5067 "<server failed to send prompt>: ");
5069 s->echo = ssh2_pkt_getbool(ssh);
5075 if (!s->method && s->can_passwd) {
5076 s->method = AUTH_PASSWORD;
5077 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5078 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5079 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5086 if (!ssh_get_line(s->pwprompt, s->password,
5087 sizeof(s->password), TRUE)) {
5089 * get_line failed to get a password (for
5090 * example because one was supplied on the
5091 * command line which has already failed to
5094 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5095 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5096 ssh2_pkt_addstring(ssh, "No more passwords available"
5098 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5100 logevent("Unable to authenticate");
5101 connection_fatal(ssh->frontend,
5102 "Unable to authenticate");
5103 ssh_closing((Plug)ssh, NULL, 0, 0);
5107 int ret; /* need not be saved across crReturn */
5108 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5111 setup_userpass_input(ssh, s->password,
5112 sizeof(s->password), s->echo);
5114 crWaitUntilV(!ispkt);
5115 ret = process_userpass_input(ssh, in, inlen);
5119 c_write_str(ssh, "\r\n");
5123 if (s->method == AUTH_PUBLICKEY_FILE) {
5125 * We have our passphrase. Now try the actual authentication.
5127 struct ssh2_userkey *key;
5128 const char *error = NULL;
5130 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5132 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5133 if (key == SSH2_WRONG_PASSPHRASE) {
5134 c_write_str(ssh, "Wrong passphrase\r\n");
5135 s->tried_pubkey_config = FALSE;
5137 c_write_str(ssh, "Unable to load private key (");
5138 c_write_str(ssh, error);
5139 c_write_str(ssh, ")\r\n");
5140 s->tried_pubkey_config = TRUE;
5142 /* Send a spurious AUTH_NONE to return to the top. */
5143 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5144 ssh2_pkt_addstring(ssh, s->username);
5145 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5146 ssh2_pkt_addstring(ssh, "none"); /* method */
5148 s->type = AUTH_TYPE_NONE;
5150 unsigned char *pkblob, *sigblob, *sigdata;
5151 int pkblob_len, sigblob_len, sigdata_len;
5155 * We have loaded the private key and the server
5156 * has announced that it's willing to accept it.
5157 * Hallelujah. Generate a signature and send it.
5159 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5160 ssh2_pkt_addstring(ssh, s->username);
5161 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5162 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5163 ssh2_pkt_addbool(ssh, TRUE);
5164 ssh2_pkt_addstring(ssh, key->alg->name);
5165 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5166 ssh2_pkt_addstring_start(ssh);
5167 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5170 * The data to be signed is:
5174 * followed by everything so far placed in the
5177 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5178 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5180 sigdata = snewn(sigdata_len, unsigned char);
5182 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5183 PUT_32BIT(sigdata+p, 20);
5186 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5187 memcpy(sigdata+p, ssh->pktout.data + 5,
5188 ssh->pktout.length - 5);
5189 p += ssh->pktout.length - 5;
5190 assert(p == sigdata_len);
5191 sigblob = key->alg->sign(key->data, (char *)sigdata,
5192 sigdata_len, &sigblob_len);
5193 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5194 sigblob, sigblob_len);
5200 s->type = AUTH_TYPE_PUBLICKEY;
5201 key->alg->freekey(key->data);
5203 } else if (s->method == AUTH_PASSWORD) {
5205 * We send the password packet lumped tightly together with
5206 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5207 * string long enough to make the total length of the two
5208 * packets constant. This should ensure that a passive
5209 * listener doing traffic analyis can't work out the length
5212 * For this to work, we need an assumption about the
5213 * maximum length of the password packet. I think 256 is
5214 * pretty conservative. Anyone using a password longer than
5215 * that probably doesn't have much to worry about from
5216 * people who find out how long their password is!
5218 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5219 ssh2_pkt_addstring(ssh, s->username);
5220 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5221 ssh2_pkt_addstring(ssh, "password");
5222 ssh2_pkt_addbool(ssh, FALSE);
5223 ssh2_pkt_addstring(ssh, s->password);
5224 memset(s->password, 0, sizeof(s->password));
5225 ssh2_pkt_defer(ssh);
5227 * We'll include a string that's an exact multiple of the
5228 * cipher block size. If the cipher is NULL for some
5229 * reason, we don't do this trick at all because we gain
5232 if (ssh->cscipher) {
5235 stringlen = (256 - ssh->deferred_len);
5236 stringlen += ssh->cscipher->blksize - 1;
5237 stringlen -= (stringlen % ssh->cscipher->blksize);
5240 * Temporarily disable actual compression,
5241 * so we can guarantee to get this string
5242 * exactly the length we want it. The
5243 * compression-disabling routine should
5244 * return an integer indicating how many
5245 * bytes we should adjust our string length
5249 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5251 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5252 ssh2_pkt_addstring_start(ssh);
5253 for (i = 0; i < stringlen; i++) {
5254 char c = (char) random_byte();
5255 ssh2_pkt_addstring_data(ssh, &c, 1);
5257 ssh2_pkt_defer(ssh);
5259 ssh_pkt_defersend(ssh);
5260 logevent("Sent password");
5261 s->type = AUTH_TYPE_PASSWORD;
5262 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5263 if (s->curr_prompt == 0) {
5264 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5265 ssh2_pkt_adduint32(ssh, s->num_prompts);
5267 if (s->need_pw) { /* only add pw if we just got one! */
5268 ssh2_pkt_addstring(ssh, s->password);
5269 memset(s->password, 0, sizeof(s->password));
5272 if (s->curr_prompt >= s->num_prompts) {
5276 * If there are prompts remaining, we set
5277 * `gotit' so that we won't attempt to get
5278 * another packet. Then we go back round the
5279 * loop and will end up retrieving another
5280 * prompt out of the existing packet. Funky or
5285 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5287 c_write_str(ssh, "No supported authentication methods"
5288 " left to try!\r\n");
5289 logevent("No supported authentications offered."
5291 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5292 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5293 ssh2_pkt_addstring(ssh, "No supported authentication"
5294 " methods available");
5295 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5297 ssh_closing((Plug)ssh, NULL, 0, 0);
5301 } while (!s->we_are_in);
5304 * Now we're authenticated for the connection protocol. The
5305 * connection protocol will automatically have started at this
5306 * point; there's no need to send SERVICE_REQUEST.
5310 * So now create a channel with a session in it.
5312 ssh->channels = newtree234(ssh_channelcmp);
5313 ssh->mainchan = snew(struct ssh_channel);
5314 ssh->mainchan->ssh = ssh;
5315 ssh->mainchan->localid = alloc_channel_id(ssh);
5316 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5317 ssh2_pkt_addstring(ssh, "session");
5318 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5319 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5320 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5321 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5323 crWaitUntilV(ispkt);
5324 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5325 bombout(("Server refused to open a session"));
5327 /* FIXME: error data comes back in FAILURE packet */
5329 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5330 bombout(("Server's channel confirmation cited wrong channel"));
5333 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5334 ssh->mainchan->type = CHAN_MAINSESSION;
5335 ssh->mainchan->closes = 0;
5336 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5337 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5338 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5339 add234(ssh->channels, ssh->mainchan);
5340 logevent("Opened channel for session");
5343 * Potentially enable X11 forwarding.
5345 if (ssh->cfg.x11_forward) {
5346 char proto[20], data[64];
5347 logevent("Requesting X11 forwarding");
5348 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5349 data, sizeof(data), ssh->cfg.x11_auth);
5350 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5351 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5352 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5353 ssh2_pkt_addstring(ssh, "x11-req");
5354 ssh2_pkt_addbool(ssh, 1); /* want reply */
5355 ssh2_pkt_addbool(ssh, 0); /* many connections */
5356 ssh2_pkt_addstring(ssh, proto);
5357 ssh2_pkt_addstring(ssh, data);
5358 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5362 crWaitUntilV(ispkt);
5363 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5364 unsigned i = ssh2_pkt_getuint32(ssh);
5365 struct ssh_channel *c;
5366 c = find234(ssh->channels, &i, ssh_channelfind);
5368 continue; /* nonexistent channel */
5369 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5371 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5373 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5374 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5375 bombout(("Unexpected response to X11 forwarding request:"
5376 " packet type %d", ssh->pktin.type));
5379 logevent("X11 forwarding refused");
5381 logevent("X11 forwarding enabled");
5382 ssh->X11_fwd_enabled = TRUE;
5387 * Enable port forwardings.
5392 int sport,dport,sserv,dserv;
5393 char sports[256], dports[256], saddr[256], host[256];
5395 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5396 /* Add port forwardings. */
5397 ssh->portfwd_strptr = ssh->cfg.portfwd;
5398 while (*ssh->portfwd_strptr) {
5399 type = *ssh->portfwd_strptr++;
5402 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5403 if (*ssh->portfwd_strptr == ':') {
5405 * We've seen a colon in the middle of the
5406 * source port number. This means that
5407 * everything we've seen until now is the
5408 * source _address_, so we'll move it into
5409 * saddr and start sports from the beginning
5412 ssh->portfwd_strptr++;
5414 strcpy(saddr, sports);
5417 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5421 if (*ssh->portfwd_strptr == '\t')
5422 ssh->portfwd_strptr++;
5424 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5425 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5428 if (*ssh->portfwd_strptr == ':')
5429 ssh->portfwd_strptr++;
5431 while (*ssh->portfwd_strptr) {
5432 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5435 ssh->portfwd_strptr++;
5436 dport = atoi(dports);
5440 dport = net_service_lookup(dports);
5442 logeventf(ssh, "Service lookup failed for destination"
5443 " port \"%s\"", dports);
5447 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5449 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5451 sport = atoi(sports);
5455 sport = net_service_lookup(sports);
5457 logeventf(ssh, "Service lookup failed for source"
5458 " port \"%s\"", sports);
5461 if (sport && dport) {
5463 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5464 sport, ssh, &ssh->cfg);
5465 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5466 " forwarding to %s:%.*s%.*s%d%.*s",
5467 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5468 (int)(*saddr?1:0), ":",
5469 (int)(sserv ? strlen(sports) : 0), sports,
5470 sserv, "(", sport, sserv, ")",
5472 (int)(dserv ? strlen(dports) : 0), dports,
5473 dserv, "(", dport, dserv, ")");
5474 } else if (type == 'D') {
5475 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5476 sport, ssh, &ssh->cfg);
5477 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5478 " doing SOCKS dynamic forwarding",
5479 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5480 (int)(*saddr?1:0), ":",
5481 (int)(sserv ? strlen(sports) : 0), sports,
5482 sserv, "(", sport, sserv, ")");
5484 struct ssh_rportfwd *pf;
5485 pf = snew(struct ssh_rportfwd);
5486 strcpy(pf->dhost, host);
5489 if (add234(ssh->rportfwds, pf) != pf) {
5490 logeventf(ssh, "Duplicate remote port forwarding"
5491 " to %s:%d", host, dport);
5494 logeventf(ssh, "Requesting remote port "
5495 "%.*s%.*s%.*s%.*s%d%.*s"
5496 " forward to %s:%.*s%.*s%d%.*s",
5497 (int)(*saddr?strlen(saddr):0),
5499 (int)(*saddr?1:0), ":",
5500 (int)(sserv ? strlen(sports) : 0), sports,
5501 sserv, "(", sport, sserv, ")",
5503 (int)(dserv ? strlen(dports) : 0), dports,
5504 dserv, "(", dport, dserv, ")");
5505 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5506 ssh2_pkt_addstring(ssh, "tcpip-forward");
5507 ssh2_pkt_addbool(ssh, 1);/* want reply */
5509 ssh2_pkt_addstring(ssh, saddr);
5510 if (ssh->cfg.rport_acceptall)
5511 ssh2_pkt_addstring(ssh, "0.0.0.0");
5513 ssh2_pkt_addstring(ssh, "127.0.0.1");
5514 ssh2_pkt_adduint32(ssh, sport);
5518 crWaitUntilV(ispkt);
5519 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5520 unsigned i = ssh2_pkt_getuint32(ssh);
5521 struct ssh_channel *c;
5522 c = find234(ssh->channels, &i, ssh_channelfind);
5524 continue;/* nonexistent channel */
5525 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5527 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5529 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5530 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5531 bombout(("Unexpected response to port "
5532 "forwarding request: packet type %d",
5536 logevent("Server refused this port forwarding");
5538 logevent("Remote port forwarding enabled");
5547 * Potentially enable agent forwarding.
5549 if (ssh->cfg.agentfwd && agent_exists()) {
5550 logevent("Requesting OpenSSH-style agent forwarding");
5551 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5552 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5553 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5554 ssh2_pkt_addbool(ssh, 1); /* want reply */
5558 crWaitUntilV(ispkt);
5559 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5560 unsigned i = ssh2_pkt_getuint32(ssh);
5561 struct ssh_channel *c;
5562 c = find234(ssh->channels, &i, ssh_channelfind);
5564 continue; /* nonexistent channel */
5565 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5567 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5569 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5570 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5571 bombout(("Unexpected response to agent forwarding request:"
5572 " packet type %d", ssh->pktin.type));
5575 logevent("Agent forwarding refused");
5577 logevent("Agent forwarding enabled");
5578 ssh->agentfwd_enabled = TRUE;
5583 * Now allocate a pty for the session.
5585 if (!ssh->cfg.nopty) {
5586 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5587 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5588 ssh2_pkt_addstring(ssh, "pty-req");
5589 ssh2_pkt_addbool(ssh, 1); /* want reply */
5590 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5591 ssh2_pkt_adduint32(ssh, ssh->term_width);
5592 ssh2_pkt_adduint32(ssh, ssh->term_height);
5593 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5594 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5595 ssh2_pkt_addstring_start(ssh);
5596 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5598 ssh->state = SSH_STATE_INTERMED;
5601 crWaitUntilV(ispkt);
5602 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5603 unsigned i = ssh2_pkt_getuint32(ssh);
5604 struct ssh_channel *c;
5605 c = find234(ssh->channels, &i, ssh_channelfind);
5607 continue; /* nonexistent channel */
5608 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5610 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5612 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5613 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5614 bombout(("Unexpected response to pty request:"
5615 " packet type %d", ssh->pktin.type));
5618 c_write_str(ssh, "Server refused to allocate pty\r\n");
5619 ssh->editing = ssh->echoing = 1;
5621 logevent("Allocated pty");
5624 ssh->editing = ssh->echoing = 1;
5628 * Start a shell or a remote command. We may have to attempt
5629 * this twice if the config data has provided a second choice
5636 if (ssh->fallback_cmd) {
5637 subsys = ssh->cfg.ssh_subsys2;
5638 cmd = ssh->cfg.remote_cmd_ptr2;
5640 subsys = ssh->cfg.ssh_subsys;
5641 cmd = ssh->cfg.remote_cmd_ptr;
5644 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5645 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5647 ssh2_pkt_addstring(ssh, "subsystem");
5648 ssh2_pkt_addbool(ssh, 1); /* want reply */
5649 ssh2_pkt_addstring(ssh, cmd);
5651 ssh2_pkt_addstring(ssh, "exec");
5652 ssh2_pkt_addbool(ssh, 1); /* want reply */
5653 ssh2_pkt_addstring(ssh, cmd);
5655 ssh2_pkt_addstring(ssh, "shell");
5656 ssh2_pkt_addbool(ssh, 1); /* want reply */
5660 crWaitUntilV(ispkt);
5661 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5662 unsigned i = ssh2_pkt_getuint32(ssh);
5663 struct ssh_channel *c;
5664 c = find234(ssh->channels, &i, ssh_channelfind);
5666 continue; /* nonexistent channel */
5667 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5669 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5670 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5671 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5672 bombout(("Unexpected response to shell/command request:"
5673 " packet type %d", ssh->pktin.type));
5677 * We failed to start the command. If this is the
5678 * fallback command, we really are finished; if it's
5679 * not, and if the fallback command exists, try falling
5680 * back to it before complaining.
5682 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5683 logevent("Primary command failed; attempting fallback");
5684 ssh->fallback_cmd = TRUE;
5687 bombout(("Server refused to start a shell/command"));
5690 logevent("Started a shell/command");
5695 ssh->state = SSH_STATE_SESSION;
5696 if (ssh->size_needed)
5697 ssh_size(ssh, ssh->term_width, ssh->term_height);
5698 if (ssh->eof_needed)
5699 ssh_special(ssh, TS_EOF);
5705 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5709 s->try_send = FALSE;
5711 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5712 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5715 unsigned i = ssh2_pkt_getuint32(ssh);
5716 struct ssh_channel *c;
5717 c = find234(ssh->channels, &i, ssh_channelfind);
5719 continue; /* nonexistent channel */
5720 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5721 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5722 continue; /* extended but not stderr */
5723 ssh2_pkt_getstring(ssh, &data, &length);
5726 c->v.v2.locwindow -= length;
5728 case CHAN_MAINSESSION:
5730 from_backend(ssh->frontend, ssh->pktin.type ==
5731 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5735 bufsize = x11_send(c->u.x11.s, data, length);
5738 bufsize = pfd_send(c->u.pfd.s, data, length);
5741 while (length > 0) {
5742 if (c->u.a.lensofar < 4) {
5743 int l = min(4 - c->u.a.lensofar, length);
5744 memcpy(c->u.a.msglen + c->u.a.lensofar,
5748 c->u.a.lensofar += l;
5750 if (c->u.a.lensofar == 4) {
5752 4 + GET_32BIT(c->u.a.msglen);
5753 c->u.a.message = snewn(c->u.a.totallen,
5755 memcpy(c->u.a.message, c->u.a.msglen, 4);
5757 if (c->u.a.lensofar >= 4 && length > 0) {
5759 min(c->u.a.totallen - c->u.a.lensofar,
5761 memcpy(c->u.a.message + c->u.a.lensofar,
5765 c->u.a.lensofar += l;
5767 if (c->u.a.lensofar == c->u.a.totallen) {
5770 if (agent_query(c->u.a.message,
5773 ssh_agentf_callback, c))
5774 ssh_agentf_callback(c, reply, replylen);
5775 sfree(c->u.a.message);
5776 c->u.a.lensofar = 0;
5783 * If we are not buffering too much data,
5784 * enlarge the window again at the remote side.
5786 if (bufsize < OUR_V2_WINSIZE)
5787 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5789 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5790 unsigned i = ssh2_pkt_getuint32(ssh);
5791 struct ssh_channel *c;
5793 c = find234(ssh->channels, &i, ssh_channelfind);
5795 continue; /* nonexistent channel */
5797 if (c->type == CHAN_X11) {
5799 * Remote EOF on an X11 channel means we should
5800 * wrap up and close the channel ourselves.
5802 x11_close(c->u.x11.s);
5804 } else if (c->type == CHAN_AGENT) {
5806 } else if (c->type == CHAN_SOCKDATA) {
5807 pfd_close(c->u.pfd.s);
5810 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5811 unsigned i = ssh2_pkt_getuint32(ssh);
5812 struct ssh_channel *c;
5814 c = find234(ssh->channels, &i, ssh_channelfind);
5815 if (!c || ((int)c->remoteid) == -1) {
5816 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5817 c ? "half-open" : "nonexistent", i));
5820 /* Do pre-close processing on the channel. */
5822 case CHAN_MAINSESSION:
5823 break; /* nothing to see here, move along */
5825 if (c->u.x11.s != NULL)
5826 x11_close(c->u.x11.s);
5833 if (c->u.pfd.s != NULL)
5834 pfd_close(c->u.pfd.s);
5838 if (c->closes == 0) {
5839 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5840 ssh2_pkt_adduint32(ssh, c->remoteid);
5843 del234(ssh->channels, c);
5844 bufchain_clear(&c->v.v2.outbuffer);
5848 * See if that was the last channel left open.
5850 if (count234(ssh->channels) == 0) {
5851 logevent("All channels closed. Disconnecting");
5854 * We used to send SSH_MSG_DISCONNECT here,
5855 * because I'd believed that _every_ conforming
5856 * SSH2 connection had to end with a disconnect
5857 * being sent by at least one side; apparently
5858 * I was wrong and it's perfectly OK to
5859 * unceremoniously slam the connection shut
5860 * when you're done, and indeed OpenSSH feels
5861 * this is more polite than sending a
5862 * DISCONNECT. So now we don't.
5864 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5865 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5866 ssh2_pkt_addstring(ssh, "All open channels closed");
5867 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5870 ssh_closing((Plug)ssh, NULL, 0, 0);
5873 continue; /* remote sends close; ignore (FIXME) */
5874 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5875 unsigned i = ssh2_pkt_getuint32(ssh);
5876 struct ssh_channel *c;
5877 c = find234(ssh->channels, &i, ssh_channelfind);
5878 if (!c || c->closes)
5879 continue; /* nonexistent or closing channel */
5880 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5882 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5883 unsigned i = ssh2_pkt_getuint32(ssh);
5884 struct ssh_channel *c;
5885 c = find234(ssh->channels, &i, ssh_channelfind);
5887 continue; /* nonexistent channel */
5888 if (c->type != CHAN_SOCKDATA_DORMANT)
5889 continue; /* dunno why they're confirming this */
5890 c->remoteid = ssh2_pkt_getuint32(ssh);
5891 c->type = CHAN_SOCKDATA;
5892 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5893 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5895 pfd_confirm(c->u.pfd.s);
5898 * We have a pending close on this channel,
5899 * which we decided on before the server acked
5900 * the channel open. So now we know the
5901 * remoteid, we can close it again.
5903 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5904 ssh2_pkt_adduint32(ssh, c->remoteid);
5907 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5908 unsigned i = ssh2_pkt_getuint32(ssh);
5909 struct ssh_channel *c;
5910 c = find234(ssh->channels, &i, ssh_channelfind);
5912 continue; /* nonexistent channel */
5913 if (c->type != CHAN_SOCKDATA_DORMANT)
5914 continue; /* dunno why they're failing this */
5916 logevent("Forwarded connection refused by server");
5918 pfd_close(c->u.pfd.s);
5920 del234(ssh->channels, c);
5922 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5925 int typelen, want_reply;
5926 struct ssh_channel *c;
5928 localid = ssh2_pkt_getuint32(ssh);
5929 ssh2_pkt_getstring(ssh, &type, &typelen);
5930 want_reply = ssh2_pkt_getbool(ssh);
5933 * First, check that the channel exists. Otherwise,
5934 * we can instantly disconnect with a rude message.
5936 c = find234(ssh->channels, &localid, ssh_channelfind);
5939 sprintf(buf, "Received channel request for nonexistent"
5940 " channel %d", localid);
5942 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5943 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5944 ssh2_pkt_addstring(ssh, buf);
5945 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5947 connection_fatal(ssh->frontend, "%s", buf);
5948 ssh_closing((Plug)ssh, NULL, 0, 0);
5953 * Having got the channel number, we now look at
5954 * the request type string to see if it's something
5957 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5958 c == ssh->mainchan) {
5959 /* We recognise "exit-status" on the primary channel. */
5961 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5962 sprintf(buf, "Server sent command exit status %d",
5966 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5967 ssh2_pkt_adduint32(ssh, c->remoteid);
5972 * This is a channel request we don't know
5973 * about, so we now either ignore the request
5974 * or respond with CHANNEL_FAILURE, depending
5978 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5979 ssh2_pkt_adduint32(ssh, c->remoteid);
5983 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5985 int typelen, want_reply;
5987 ssh2_pkt_getstring(ssh, &type, &typelen);
5988 want_reply = ssh2_pkt_getbool(ssh);
5991 * We currently don't support any global requests
5992 * at all, so we either ignore the request or
5993 * respond with REQUEST_FAILURE, depending on
5997 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6000 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6007 struct ssh_channel *c;
6008 unsigned remid, winsize, pktsize;
6009 ssh2_pkt_getstring(ssh, &type, &typelen);
6010 c = snew(struct ssh_channel);
6013 remid = ssh2_pkt_getuint32(ssh);
6014 winsize = ssh2_pkt_getuint32(ssh);
6015 pktsize = ssh2_pkt_getuint32(ssh);
6017 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6020 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6021 addrstr = snewn(peeraddrlen+1, char);
6022 memcpy(addrstr, peeraddr, peeraddrlen);
6023 peeraddr[peeraddrlen] = '\0';
6024 peerport = ssh2_pkt_getuint32(ssh);
6026 if (!ssh->X11_fwd_enabled)
6027 error = "X11 forwarding is not enabled";
6028 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6029 ssh->x11auth, addrstr, peerport,
6030 &ssh->cfg) != NULL) {
6031 error = "Unable to open an X11 connection";
6037 } else if (typelen == 15 &&
6038 !memcmp(type, "forwarded-tcpip", 15)) {
6039 struct ssh_rportfwd pf, *realpf;
6042 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6043 pf.sport = ssh2_pkt_getuint32(ssh);
6044 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6045 peerport = ssh2_pkt_getuint32(ssh);
6046 realpf = find234(ssh->rportfwds, &pf, NULL);
6047 if (realpf == NULL) {
6048 error = "Remote port is not recognised";
6050 const char *e = pfd_newconnect(&c->u.pfd.s,
6054 logeventf(ssh, "Received remote port open request"
6055 " for %s:%d", realpf->dhost, realpf->dport);
6057 logeventf(ssh, "Port open failed: %s", e);
6058 error = "Port open failed";
6060 logevent("Forwarded port opened successfully");
6061 c->type = CHAN_SOCKDATA;
6064 } else if (typelen == 22 &&
6065 !memcmp(type, "auth-agent@openssh.com", 3)) {
6066 if (!ssh->agentfwd_enabled)
6067 error = "Agent forwarding is not enabled";
6069 c->type = CHAN_AGENT; /* identify channel type */
6070 c->u.a.lensofar = 0;
6073 error = "Unsupported channel type requested";
6076 c->remoteid = remid;
6078 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6079 ssh2_pkt_adduint32(ssh, c->remoteid);
6080 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6081 ssh2_pkt_addstring(ssh, error);
6082 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6086 c->localid = alloc_channel_id(ssh);
6088 c->v.v2.locwindow = OUR_V2_WINSIZE;
6089 c->v.v2.remwindow = winsize;
6090 c->v.v2.remmaxpkt = pktsize;
6091 bufchain_init(&c->v.v2.outbuffer);
6092 add234(ssh->channels, c);
6093 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6094 ssh2_pkt_adduint32(ssh, c->remoteid);
6095 ssh2_pkt_adduint32(ssh, c->localid);
6096 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6097 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6101 bombout(("Strange packet received: type %d", ssh->pktin.type));
6106 * We have spare data. Add it to the channel buffer.
6108 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6113 struct ssh_channel *c;
6115 * Try to send data on all channels if we can.
6117 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6120 continue; /* don't send on closing channels */
6121 bufsize = ssh2_try_send(c);
6124 case CHAN_MAINSESSION:
6125 /* stdin need not receive an unthrottle
6126 * notification since it will be polled */
6129 x11_unthrottle(c->u.x11.s);
6132 /* agent sockets are request/response and need no
6133 * buffer management */
6136 pfd_unthrottle(c->u.pfd.s);
6148 * Handle the top-level SSH2 protocol.
6150 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6152 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6154 do_ssh2_authconn(ssh, in, inlen, ispkt);
6158 * Called to set up the connection.
6160 * Returns an error message, or NULL on success.
6162 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6164 char *host, int port, char **realhost, int nodelay)
6169 ssh = snew(struct ssh_tag);
6170 ssh->cfg = *cfg; /* STRUCTURE COPY */
6171 ssh->version = 0; /* when not ready yet */
6174 ssh->v1_cipher_ctx = NULL;
6175 ssh->crcda_ctx = NULL;
6176 ssh->cscipher = NULL;
6177 ssh->cs_cipher_ctx = NULL;
6178 ssh->sccipher = NULL;
6179 ssh->sc_cipher_ctx = NULL;
6181 ssh->cs_mac_ctx = NULL;
6183 ssh->sc_mac_ctx = NULL;
6185 ssh->cs_comp_ctx = NULL;
6187 ssh->sc_comp_ctx = NULL;
6189 ssh->kex_ctx = NULL;
6190 ssh->hostkey = NULL;
6192 ssh->state = SSH_STATE_PREPACKET;
6193 ssh->size_needed = FALSE;
6194 ssh->eof_needed = FALSE;
6198 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6199 ssh->pktin = ssh->pktout = empty;
6201 ssh->deferred_send_data = NULL;
6202 ssh->deferred_len = 0;
6203 ssh->deferred_size = 0;
6204 ssh->fallback_cmd = 0;
6206 ssh->x11auth = NULL;
6207 ssh->v1_compressing = FALSE;
6208 ssh->v2_outgoing_sequence = 0;
6209 ssh->ssh1_rdpkt_crstate = 0;
6210 ssh->ssh2_rdpkt_crstate = 0;
6211 ssh->do_ssh_init_crstate = 0;
6212 ssh->ssh_gotdata_crstate = 0;
6213 ssh->ssh1_protocol_crstate = 0;
6214 ssh->do_ssh1_login_crstate = 0;
6215 ssh->do_ssh2_transport_crstate = 0;
6216 ssh->do_ssh2_authconn_crstate = 0;
6217 ssh->do_ssh_init_state = NULL;
6218 ssh->do_ssh1_login_state = NULL;
6219 ssh->do_ssh2_transport_state = NULL;
6220 ssh->do_ssh2_authconn_state = NULL;
6221 ssh->mainchan = NULL;
6222 ssh->throttled_all = 0;
6223 ssh->v1_stdout_throttling = 0;
6225 *backend_handle = ssh;
6228 if (crypto_startup() == 0)
6229 return "Microsoft high encryption pack not installed!";
6232 ssh->frontend = frontend_handle;
6233 ssh->term_width = ssh->cfg.width;
6234 ssh->term_height = ssh->cfg.height;
6236 ssh->channels = NULL;
6237 ssh->rportfwds = NULL;
6242 ssh->v1_throttle_count = 0;
6243 ssh->overall_bufsize = 0;
6244 ssh->fallback_cmd = 0;
6246 ssh->protocol = NULL;
6248 p = connect_to_host(ssh, host, port, realhost, nodelay);
6255 static void ssh_free(void *handle)
6257 Ssh ssh = (Ssh) handle;
6258 struct ssh_channel *c;
6259 struct ssh_rportfwd *pf;
6261 if (ssh->v1_cipher_ctx)
6262 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6263 if (ssh->cs_cipher_ctx)
6264 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6265 if (ssh->sc_cipher_ctx)
6266 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6267 if (ssh->cs_mac_ctx)
6268 ssh->csmac->free_context(ssh->cs_mac_ctx);
6269 if (ssh->sc_mac_ctx)
6270 ssh->scmac->free_context(ssh->sc_mac_ctx);
6271 if (ssh->cs_comp_ctx) {
6273 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6275 zlib_compress_cleanup(ssh->cs_comp_ctx);
6277 if (ssh->sc_comp_ctx) {
6279 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6281 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6284 dh_cleanup(ssh->kex_ctx);
6285 sfree(ssh->savedhost);
6287 if (ssh->channels) {
6288 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6291 if (c->u.x11.s != NULL)
6292 x11_close(c->u.x11.s);
6295 if (c->u.pfd.s != NULL)
6296 pfd_close(c->u.pfd.s);
6301 freetree234(ssh->channels);
6304 if (ssh->rportfwds) {
6305 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6307 freetree234(ssh->rportfwds);
6309 sfree(ssh->deferred_send_data);
6311 x11_free_auth(ssh->x11auth);
6312 sfree(ssh->do_ssh_init_state);
6313 sfree(ssh->do_ssh1_login_state);
6314 sfree(ssh->do_ssh2_transport_state);
6315 sfree(ssh->do_ssh2_authconn_state);
6316 if (ssh->pktout.data) {
6317 sfree(ssh->pktout.data);
6318 ssh->pktout.data = NULL;
6320 if (ssh->pktin.data) {
6321 sfree(ssh->pktin.data);
6322 ssh->pktin.data = NULL;
6324 if (ssh->crcda_ctx) {
6325 crcda_free_context(ssh->crcda_ctx);
6326 ssh->crcda_ctx = NULL;
6329 log_free(ssh->logctx);
6338 * Reconfigure the SSH backend.
6340 * Currently, this function does nothing very useful. In future,
6341 * however, we could do some handy things with it. For example, we
6342 * could make the port forwarding configurer active in the Change
6343 * Settings box, and this routine could close down existing
6344 * forwardings and open up new ones in response to changes.
6346 static void ssh_reconfig(void *handle, Config *cfg)
6348 Ssh ssh = (Ssh) handle;
6349 ssh->cfg = *cfg; /* STRUCTURE COPY */
6353 * Called to send data down the Telnet connection.
6355 static int ssh_send(void *handle, char *buf, int len)
6357 Ssh ssh = (Ssh) handle;
6359 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6362 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6364 return ssh_sendbuffer(ssh);
6368 * Called to query the current amount of buffered stdin data.
6370 static int ssh_sendbuffer(void *handle)
6372 Ssh ssh = (Ssh) handle;
6375 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6379 * If the SSH socket itself has backed up, add the total backup
6380 * size on that to any individual buffer on the stdin channel.
6383 if (ssh->throttled_all)
6384 override_value = ssh->overall_bufsize;
6386 if (ssh->version == 1) {
6387 return override_value;
6388 } else if (ssh->version == 2) {
6389 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6390 return override_value;
6392 return (override_value +
6393 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6400 * Called to set the size of the window from SSH's POV.
6402 static void ssh_size(void *handle, int width, int height)
6404 Ssh ssh = (Ssh) handle;
6406 ssh->term_width = width;
6407 ssh->term_height = height;
6409 switch (ssh->state) {
6410 case SSH_STATE_BEFORE_SIZE:
6411 case SSH_STATE_PREPACKET:
6412 case SSH_STATE_CLOSED:
6413 break; /* do nothing */
6414 case SSH_STATE_INTERMED:
6415 ssh->size_needed = TRUE; /* buffer for later */
6417 case SSH_STATE_SESSION:
6418 if (!ssh->cfg.nopty) {
6419 if (ssh->version == 1) {
6420 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6421 PKT_INT, ssh->term_height,
6422 PKT_INT, ssh->term_width,
6423 PKT_INT, 0, PKT_INT, 0, PKT_END);
6425 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6426 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6427 ssh2_pkt_addstring(ssh, "window-change");
6428 ssh2_pkt_addbool(ssh, 0);
6429 ssh2_pkt_adduint32(ssh, ssh->term_width);
6430 ssh2_pkt_adduint32(ssh, ssh->term_height);
6431 ssh2_pkt_adduint32(ssh, 0);
6432 ssh2_pkt_adduint32(ssh, 0);
6441 * Return a list of the special codes that make sense in this
6444 static const struct telnet_special *ssh_get_specials(void *handle)
6446 Ssh ssh = (Ssh) handle;
6448 if (ssh->version == 1) {
6449 static const struct telnet_special ssh1_specials[] = {
6450 {"IGNORE message", TS_NOP},
6453 return ssh1_specials;
6454 } else if (ssh->version == 2) {
6455 static const struct telnet_special ssh2_specials[] = {
6457 {"IGNORE message", TS_NOP},
6460 return ssh2_specials;
6466 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6467 * can send an EOF and collect resulting output (e.g. `plink
6470 static void ssh_special(void *handle, Telnet_Special code)
6472 Ssh ssh = (Ssh) handle;
6474 if (code == TS_EOF) {
6475 if (ssh->state != SSH_STATE_SESSION) {
6477 * Buffer the EOF in case we are pre-SESSION, so we can
6478 * send it as soon as we reach SESSION.
6481 ssh->eof_needed = TRUE;
6484 if (ssh->version == 1) {
6485 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6487 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6488 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6491 logevent("Sent EOF message");
6492 } else if (code == TS_PING || code == TS_NOP) {
6493 if (ssh->state == SSH_STATE_CLOSED
6494 || ssh->state == SSH_STATE_PREPACKET) return;
6495 if (ssh->version == 1) {
6496 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6497 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6499 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6500 ssh2_pkt_addstring_start(ssh);
6503 } else if (code == TS_BRK) {
6504 if (ssh->state == SSH_STATE_CLOSED
6505 || ssh->state == SSH_STATE_PREPACKET) return;
6506 if (ssh->version == 1) {
6507 logevent("Unable to send BREAK signal in SSH1");
6509 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6510 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6511 ssh2_pkt_addstring(ssh, "break");
6512 ssh2_pkt_addbool(ssh, 0);
6513 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6521 void *new_sock_channel(void *handle, Socket s)
6523 Ssh ssh = (Ssh) handle;
6524 struct ssh_channel *c;
6525 c = snew(struct ssh_channel);
6529 c->remoteid = -1; /* to be set when open confirmed */
6530 c->localid = alloc_channel_id(ssh);
6532 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6534 bufchain_init(&c->v.v2.outbuffer);
6535 add234(ssh->channels, c);
6541 * This is called when stdout/stderr (the entity to which
6542 * from_backend sends data) manages to clear some backlog.
6544 static void ssh_unthrottle(void *handle, int bufsize)
6546 Ssh ssh = (Ssh) handle;
6547 if (ssh->version == 1) {
6548 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6549 ssh->v1_stdout_throttling = 0;
6550 ssh1_throttle(ssh, -1);
6553 if (ssh->mainchan && ssh->mainchan->closes == 0)
6554 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6558 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6560 struct ssh_channel *c = (struct ssh_channel *)channel;
6563 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6565 if (ssh->version == 1) {
6566 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6567 PKT_INT, c->localid,
6570 //PKT_STR, <org:orgport>,
6573 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6574 ssh2_pkt_addstring(ssh, "direct-tcpip");
6575 ssh2_pkt_adduint32(ssh, c->localid);
6576 c->v.v2.locwindow = OUR_V2_WINSIZE;
6577 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6578 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6579 ssh2_pkt_addstring(ssh, hostname);
6580 ssh2_pkt_adduint32(ssh, port);
6582 * We make up values for the originator data; partly it's
6583 * too much hassle to keep track, and partly I'm not
6584 * convinced the server should be told details like that
6585 * about my local network configuration.
6587 ssh2_pkt_addstring(ssh, "client-side-connection");
6588 ssh2_pkt_adduint32(ssh, 0);
6594 static Socket ssh_socket(void *handle)
6596 Ssh ssh = (Ssh) handle;
6600 static int ssh_sendok(void *handle)
6602 Ssh ssh = (Ssh) handle;
6603 return ssh->send_ok;
6606 static int ssh_ldisc(void *handle, int option)
6608 Ssh ssh = (Ssh) handle;
6609 if (option == LD_ECHO)
6610 return ssh->echoing;
6611 if (option == LD_EDIT)
6612 return ssh->editing;
6616 static void ssh_provide_ldisc(void *handle, void *ldisc)
6618 Ssh ssh = (Ssh) handle;
6622 static void ssh_provide_logctx(void *handle, void *logctx)
6624 Ssh ssh = (Ssh) handle;
6625 ssh->logctx = logctx;
6628 static int ssh_return_exitcode(void *handle)
6630 Ssh ssh = (Ssh) handle;
6634 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6638 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6639 * that fails. This variable is the means by which scp.c can reach
6640 * into the SSH code and find out which one it got.
6642 extern int ssh_fallback_cmd(void *handle)
6644 Ssh ssh = (Ssh) handle;
6645 return ssh->fallback_cmd;
6648 Backend ssh_backend = {
6658 ssh_return_exitcode,