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);
327 * Buffer management constants. There are several of these for
328 * various different purposes:
330 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
331 * on a local data stream before we throttle the whole SSH
332 * connection (in SSH1 only). Throttling the whole connection is
333 * pretty drastic so we set this high in the hope it won't
336 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
337 * on the SSH connection itself before we defensively throttle
338 * _all_ local data streams. This is pretty drastic too (though
339 * thankfully unlikely in SSH2 since the window mechanism should
340 * ensure that the server never has any need to throttle its end
341 * of the connection), so we set this high as well.
343 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
347 #define SSH1_BUFFER_LIMIT 32768
348 #define SSH_MAX_BACKLOG 32768
349 #define OUR_V2_WINSIZE 16384
351 const static struct ssh_kex *kex_algs[] = {
352 &ssh_diffiehellman_gex,
356 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
358 static void *nullmac_make_context(void)
362 static void nullmac_free_context(void *handle)
365 static void nullmac_key(void *handle, unsigned char *key)
368 static void nullmac_generate(void *handle, unsigned char *blk, int len,
372 static int nullmac_verify(void *handle, unsigned char *blk, int len,
377 const static struct ssh_mac ssh_mac_none = {
378 nullmac_make_context, nullmac_free_context, nullmac_key,
379 nullmac_generate, nullmac_verify, "none", 0
381 const static struct ssh_mac *macs[] = {
382 &ssh_sha1, &ssh_md5, &ssh_mac_none
384 const static struct ssh_mac *buggymacs[] = {
385 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
388 static void *ssh_comp_none_init(void)
392 static void ssh_comp_none_cleanup(void *handle)
395 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
396 unsigned char **outblock, int *outlen)
400 static int ssh_comp_none_disable(void *handle)
404 const static struct ssh_compress ssh_comp_none = {
406 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
407 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
408 ssh_comp_none_disable, NULL
410 extern const struct ssh_compress ssh_zlib;
411 const static struct ssh_compress *compressions[] = {
412 &ssh_zlib, &ssh_comp_none
415 enum { /* channel types */
420 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
424 * 2-3-4 tree storing channels.
427 Ssh ssh; /* pointer back to main context */
428 unsigned remoteid, localid;
431 * In SSH1, this value contains four bits:
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
438 * A channel is completely finished with when all four bits are set.
442 struct ssh1_data_channel {
445 struct ssh2_data_channel {
447 unsigned remwindow, remmaxpkt;
452 struct ssh_agent_channel {
453 unsigned char *message;
454 unsigned char msglen[4];
455 int lensofar, totallen;
457 struct ssh_x11_channel {
460 struct ssh_pfd_channel {
467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
495 struct ssh_rportfwd {
496 unsigned sport, dport;
509 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
510 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
511 static void ssh_size(void *handle, int width, int height);
512 static void ssh_special(void *handle, Telnet_Special);
513 static int ssh2_try_send(struct ssh_channel *c);
514 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
515 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
516 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
517 static int ssh_sendbuffer(void *handle);
519 struct rdpkt1_state_tag {
520 long len, pad, biglen, to_read;
521 unsigned long realcrc, gotcrc;
527 struct rdpkt2_state_tag {
528 long len, pad, payload, packetlen, maclen;
531 unsigned long incoming_sequence;
535 const struct plug_function_table *fn;
536 /* the above field _must_ be first in the structure */
538 SHA_State exhash, exhashbase;
545 unsigned char session_key[32];
547 int v1_remote_protoflags;
548 int v1_local_protoflags;
549 int agentfwd_enabled;
552 const struct ssh_cipher *cipher;
555 const struct ssh2_cipher *cscipher, *sccipher;
556 void *cs_cipher_ctx, *sc_cipher_ctx;
557 const struct ssh_mac *csmac, *scmac;
558 void *cs_mac_ctx, *sc_mac_ctx;
559 const struct ssh_compress *cscomp, *sccomp;
560 void *cs_comp_ctx, *sc_comp_ctx;
561 const struct ssh_kex *kex;
562 const struct ssh_signkey *hostkey;
563 unsigned char v2_session_id[20];
569 int echoing, editing;
573 int term_width, term_height;
575 tree234 *channels; /* indexed by local id */
576 struct ssh_channel *mainchan; /* primary session channel */
583 SSH_STATE_BEFORE_SIZE,
589 int size_needed, eof_needed;
592 struct Packet pktout;
593 unsigned char *deferred_send_data;
594 int deferred_len, deferred_size;
597 * Gross hack: pscp will try to start SFTP but fall back to
598 * scp1 if that fails. This variable is the means by which
599 * scp.c can reach into the SSH code and find out which one it
605 * Used for username and password input.
607 char *userpass_input_buffer;
608 int userpass_input_buflen;
609 int userpass_input_bufpos;
610 int userpass_input_echo;
612 char *portfwd_strptr;
618 int v1_throttle_count;
621 int v1_stdout_throttling;
622 int v2_outgoing_sequence;
624 int ssh1_rdpkt_crstate;
625 int ssh2_rdpkt_crstate;
626 int do_ssh_init_crstate;
627 int ssh_gotdata_crstate;
628 int ssh1_protocol_crstate;
629 int do_ssh1_login_crstate;
630 int do_ssh2_transport_crstate;
631 int do_ssh2_authconn_crstate;
633 void *do_ssh_init_state;
634 void *do_ssh1_login_state;
635 void *do_ssh2_transport_state;
636 void *do_ssh2_authconn_state;
638 struct rdpkt1_state_tag rdpkt1_state;
639 struct rdpkt2_state_tag rdpkt2_state;
641 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
642 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
645 * We maintain a full _copy_ of a Config structure here, not
646 * merely a pointer to it. That way, when we're passed a new
647 * one for reconfiguration, we can check the differences and
648 * potentially reconfigure port forwardings etc in mid-session.
653 #define logevent(s) logevent(ssh->frontend, s)
655 /* logevent, only printf-formatted. */
656 static void logeventf(Ssh ssh, char *fmt, ...)
662 buf = dupvprintf(fmt, ap);
668 #define bombout(msg) \
670 char *text = dupprintf msg; \
671 ssh->state = SSH_STATE_CLOSED; \
672 if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; } \
674 connection_fatal(ssh->frontend, "%s", text); \
678 static int ssh_channelcmp(void *av, void *bv)
680 struct ssh_channel *a = (struct ssh_channel *) av;
681 struct ssh_channel *b = (struct ssh_channel *) bv;
682 if (a->localid < b->localid)
684 if (a->localid > b->localid)
688 static int ssh_channelfind(void *av, void *bv)
690 unsigned *a = (unsigned *) av;
691 struct ssh_channel *b = (struct ssh_channel *) bv;
699 static int ssh_rportcmp_ssh1(void *av, void *bv)
701 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
702 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
704 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
705 return i < 0 ? -1 : +1;
706 if (a->dport > b->dport)
708 if (a->dport < b->dport)
713 static int ssh_rportcmp_ssh2(void *av, void *bv)
715 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
716 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
718 if (a->sport > b->sport)
720 if (a->sport < b->sport)
725 static int alloc_channel_id(Ssh ssh)
727 const unsigned CHANNEL_NUMBER_OFFSET = 256;
728 unsigned low, high, mid;
730 struct ssh_channel *c;
733 * First-fit allocation of channel numbers: always pick the
734 * lowest unused one. To do this, binary-search using the
735 * counted B-tree to find the largest channel ID which is in a
736 * contiguous sequence from the beginning. (Precisely
737 * everything in that sequence must have ID equal to its tree
738 * index plus CHANNEL_NUMBER_OFFSET.)
740 tsize = count234(ssh->channels);
744 while (high - low > 1) {
745 mid = (high + low) / 2;
746 c = index234(ssh->channels, mid);
747 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
748 low = mid; /* this one is fine */
750 high = mid; /* this one is past it */
753 * Now low points to either -1, or the tree index of the
754 * largest ID in the initial sequence.
757 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
758 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
760 return low + 1 + CHANNEL_NUMBER_OFFSET;
763 static void c_write(Ssh ssh, const char *buf, int len)
765 if ((flags & FLAG_STDERR)) {
767 for (i = 0; i < len; i++)
769 fputc(buf[i], stderr);
772 from_backend(ssh->frontend, 1, buf, len);
775 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
778 for (i = 0; i < len; i++) {
780 c_write(ssh, "\r\n", 2);
781 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
782 c_write(ssh, buf + i, 1);
786 static void c_write_str(Ssh ssh, const char *buf)
788 c_write(ssh, buf, strlen(buf));
792 * Collect incoming data in the incoming packet buffer.
793 * Decipher and verify the packet when it is completely read.
794 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
795 * Update the *data and *datalen variables.
796 * Return the additional nr of bytes needed, or 0 when
797 * a complete packet is available.
799 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
801 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
803 crBegin(ssh->ssh1_rdpkt_crstate);
808 ssh->pktin.length = 0;
810 for (st->i = st->len = 0; st->i < 4; st->i++) {
811 while ((*datalen) == 0)
813 st->len = (st->len << 8) + **data;
814 (*data)++, (*datalen)--;
817 st->pad = 8 - (st->len % 8);
818 st->biglen = st->len + st->pad;
819 ssh->pktin.length = st->len - 5;
821 if (ssh->pktin.maxlen < st->biglen) {
822 ssh->pktin.maxlen = st->biglen;
823 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
827 st->to_read = st->biglen;
828 st->p = ssh->pktin.data;
829 while (st->to_read > 0) {
830 st->chunk = st->to_read;
831 while ((*datalen) == 0)
832 crReturn(st->to_read);
833 if (st->chunk > (*datalen))
834 st->chunk = (*datalen);
835 memcpy(st->p, *data, st->chunk);
837 *datalen -= st->chunk;
839 st->to_read -= st->chunk;
842 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
844 bombout(("Network attack (CRC compensation) detected!"));
849 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
851 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
852 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
853 if (st->gotcrc != st->realcrc) {
854 bombout(("Incorrect CRC received on packet"));
858 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
860 if (ssh->v1_compressing) {
861 unsigned char *decompblk;
863 zlib_decompress_block(ssh->sc_comp_ctx,
864 ssh->pktin.body - 1, ssh->pktin.length + 1,
865 &decompblk, &decomplen);
867 if (ssh->pktin.maxlen < st->pad + decomplen) {
868 ssh->pktin.maxlen = st->pad + decomplen;
869 ssh->pktin.data = sresize(ssh->pktin.data,
870 ssh->pktin.maxlen + APIEXTRA,
872 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
875 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
877 ssh->pktin.length = decomplen - 1;
880 ssh->pktin.type = ssh->pktin.body[-1];
883 log_packet(ssh->logctx,
884 PKT_INCOMING, ssh->pktin.type,
885 ssh1_pkt_type(ssh->pktin.type),
886 ssh->pktin.body, ssh->pktin.length);
888 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
889 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
890 ssh->pktin.type == SSH1_MSG_DEBUG ||
891 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
892 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
893 long stringlen = GET_32BIT(ssh->pktin.body);
894 if (stringlen + 4 != ssh->pktin.length) {
895 bombout(("Received data packet with bogus string length"));
900 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
901 /* log debug message */
903 int stringlen = GET_32BIT(ssh->pktin.body);
904 strcpy(buf, "Remote debug message: ");
907 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
908 buf[8 + stringlen] = '\0';
911 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
916 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
917 /* log reason code in disconnect message */
919 unsigned msglen = GET_32BIT(ssh->pktin.body);
921 strcpy(buf, "Remote sent disconnect: ");
922 nowlen = strlen(buf);
923 if (msglen > sizeof(buf) - nowlen - 1)
924 msglen = sizeof(buf) - nowlen - 1;
925 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
926 buf[nowlen + msglen] = '\0';
927 /* logevent(buf); (this is now done within the bombout macro) */
928 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
935 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
937 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
939 crBegin(ssh->ssh2_rdpkt_crstate);
943 ssh->pktin.length = 0;
945 st->cipherblk = ssh->sccipher->blksize;
948 if (st->cipherblk < 8)
951 if (ssh->pktin.maxlen < st->cipherblk) {
952 ssh->pktin.maxlen = st->cipherblk;
953 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
958 * Acquire and decrypt the first block of the packet. This will
959 * contain the length and padding details.
961 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
962 while ((*datalen) == 0)
963 crReturn(st->cipherblk - st->i);
964 ssh->pktin.data[st->i] = *(*data)++;
969 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
970 ssh->pktin.data, st->cipherblk);
973 * Now get the length and padding figures.
975 st->len = GET_32BIT(ssh->pktin.data);
976 st->pad = ssh->pktin.data[4];
979 * _Completely_ silly lengths should be stomped on before they
980 * do us any more damage.
982 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
983 bombout(("Incoming packet was garbled on decryption"));
988 * This enables us to deduce the payload length.
990 st->payload = st->len - st->pad - 1;
992 ssh->pktin.length = st->payload + 5;
995 * So now we can work out the total packet length.
997 st->packetlen = st->len + 4;
998 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1001 * Adjust memory allocation if packet is too big.
1003 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1004 ssh->pktin.maxlen = st->packetlen + st->maclen;
1005 ssh->pktin.data = sresize(ssh->pktin.data,
1006 ssh->pktin.maxlen + APIEXTRA,
1011 * Read and decrypt the remainder of the packet.
1013 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1015 while ((*datalen) == 0)
1016 crReturn(st->packetlen + st->maclen - st->i);
1017 ssh->pktin.data[st->i] = *(*data)++;
1020 /* Decrypt everything _except_ the MAC. */
1022 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1023 ssh->pktin.data + st->cipherblk,
1024 st->packetlen - st->cipherblk);
1030 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1031 st->incoming_sequence)) {
1032 bombout(("Incorrect MAC received on packet"));
1035 st->incoming_sequence++; /* whether or not we MACed */
1038 * Decompress packet payload.
1041 unsigned char *newpayload;
1044 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1045 ssh->pktin.data + 5, ssh->pktin.length - 5,
1046 &newpayload, &newlen)) {
1047 if (ssh->pktin.maxlen < newlen + 5) {
1048 ssh->pktin.maxlen = newlen + 5;
1049 ssh->pktin.data = sresize(ssh->pktin.data,
1050 ssh->pktin.maxlen + APIEXTRA,
1053 ssh->pktin.length = 5 + newlen;
1054 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1059 ssh->pktin.savedpos = 6;
1060 ssh->pktin.type = ssh->pktin.data[5];
1063 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1064 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1065 ssh->pktin.data+6, ssh->pktin.length-6);
1067 switch (ssh->pktin.type) {
1069 * These packets we must handle instantly.
1071 case SSH2_MSG_DISCONNECT:
1073 /* log reason code in disconnect message */
1076 int reason = GET_32BIT(ssh->pktin.data + 6);
1077 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1079 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1080 buf = dupprintf("Received disconnect message (%s)",
1081 ssh2_disconnect_reasons[reason]);
1083 buf = dupprintf("Received disconnect message (unknown"
1084 " type %d)", reason);
1088 buf = dupprintf("Disconnection message text: %n%.*s",
1089 &nowlen, msglen, ssh->pktin.data + 14);
1091 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1093 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1094 ssh2_disconnect_reasons[reason] : "unknown",
1100 case SSH2_MSG_IGNORE:
1102 case SSH2_MSG_DEBUG:
1104 /* log the debug message */
1106 /* int display = ssh->pktin.body[6]; */
1107 int stringlen = GET_32BIT(ssh->pktin.data+7);
1109 strcpy(buf, "Remote debug message: ");
1110 prefix = strlen(buf);
1111 if (stringlen > (int)(sizeof(buf)-prefix-1))
1112 stringlen = sizeof(buf)-prefix-1;
1113 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1114 buf[prefix + stringlen] = '\0';
1117 goto next_packet; /* FIXME: print the debug message */
1120 * These packets we need do nothing about here.
1122 case SSH2_MSG_UNIMPLEMENTED:
1123 case SSH2_MSG_SERVICE_REQUEST:
1124 case SSH2_MSG_SERVICE_ACCEPT:
1125 case SSH2_MSG_KEXINIT:
1126 case SSH2_MSG_NEWKEYS:
1127 case SSH2_MSG_KEXDH_INIT:
1128 case SSH2_MSG_KEXDH_REPLY:
1129 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1130 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1131 case SSH2_MSG_KEX_DH_GEX_INIT:
1132 case SSH2_MSG_KEX_DH_GEX_REPLY:
1133 case SSH2_MSG_USERAUTH_REQUEST:
1134 case SSH2_MSG_USERAUTH_FAILURE:
1135 case SSH2_MSG_USERAUTH_SUCCESS:
1136 case SSH2_MSG_USERAUTH_BANNER:
1137 case SSH2_MSG_USERAUTH_PK_OK:
1138 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1139 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1140 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1141 case SSH2_MSG_GLOBAL_REQUEST:
1142 case SSH2_MSG_REQUEST_SUCCESS:
1143 case SSH2_MSG_REQUEST_FAILURE:
1144 case SSH2_MSG_CHANNEL_OPEN:
1145 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1146 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1147 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1148 case SSH2_MSG_CHANNEL_DATA:
1149 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1150 case SSH2_MSG_CHANNEL_EOF:
1151 case SSH2_MSG_CHANNEL_CLOSE:
1152 case SSH2_MSG_CHANNEL_REQUEST:
1153 case SSH2_MSG_CHANNEL_SUCCESS:
1154 case SSH2_MSG_CHANNEL_FAILURE:
1158 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1161 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1162 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1170 static void ssh1_pktout_size(Ssh ssh, int len)
1174 len += 5; /* type and CRC */
1175 pad = 8 - (len % 8);
1178 ssh->pktout.length = len - 5;
1179 if (ssh->pktout.maxlen < biglen) {
1180 ssh->pktout.maxlen = biglen;
1182 /* Allocate enough buffer space for extra block
1183 * for MS CryptEncrypt() */
1184 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1187 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1191 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1194 static void s_wrpkt_start(Ssh ssh, int type, int len)
1196 ssh1_pktout_size(ssh, len);
1197 ssh->pktout.type = type;
1200 static int s_wrpkt_prepare(Ssh ssh)
1206 * XXX various versions of SC (including 8.8.4) screw up the
1207 * register allocation in this function and use the same register
1208 * (D6) for len and as a temporary, with predictable results. The
1209 * following sledgehammer prevents this.
1215 ssh->pktout.body[-1] = ssh->pktout.type;
1218 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1219 ssh1_pkt_type(ssh->pktout.type),
1220 ssh->pktout.body, ssh->pktout.length);
1222 if (ssh->v1_compressing) {
1223 unsigned char *compblk;
1225 zlib_compress_block(ssh->cs_comp_ctx,
1226 ssh->pktout.body - 1, ssh->pktout.length + 1,
1227 &compblk, &complen);
1228 ssh1_pktout_size(ssh, complen - 1);
1229 memcpy(ssh->pktout.body - 1, compblk, complen);
1233 len = ssh->pktout.length + 5; /* type and CRC */
1234 pad = 8 - (len % 8);
1237 for (i = 0; i < pad; i++)
1238 ssh->pktout.data[i + 4] = random_byte();
1239 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1240 PUT_32BIT(ssh->pktout.data + biglen, crc);
1241 PUT_32BIT(ssh->pktout.data, len);
1244 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1249 static void s_wrpkt(Ssh ssh)
1252 len = s_wrpkt_prepare(ssh);
1253 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1254 if (backlog > SSH_MAX_BACKLOG)
1255 ssh_throttle_all(ssh, 1, backlog);
1258 static void s_wrpkt_defer(Ssh ssh)
1261 len = s_wrpkt_prepare(ssh);
1262 if (ssh->deferred_len + len > ssh->deferred_size) {
1263 ssh->deferred_size = ssh->deferred_len + len + 128;
1264 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1268 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1269 ssh->deferred_len += len;
1273 * Construct a packet with the specified contents.
1275 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1277 unsigned char *p, *argp, argchar;
1278 unsigned long argint;
1279 int pktlen, argtype, arglen;
1283 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1286 (void) va_arg(ap1, int);
1290 (void) va_arg(ap1, int);
1294 (void) va_arg(ap1, unsigned char *);
1295 arglen = va_arg(ap1, int);
1299 argp = va_arg(ap1, unsigned char *);
1300 arglen = strlen((char *)argp);
1301 pktlen += 4 + arglen;
1304 bn = va_arg(ap1, Bignum);
1305 pktlen += ssh1_bignum_length(bn);
1312 s_wrpkt_start(ssh, pkttype, pktlen);
1313 p = ssh->pktout.body;
1315 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1318 argint = va_arg(ap2, int);
1319 PUT_32BIT(p, argint);
1323 argchar = (unsigned char) va_arg(ap2, int);
1328 argp = va_arg(ap2, unsigned char *);
1329 arglen = va_arg(ap2, int);
1330 memcpy(p, argp, arglen);
1334 argp = va_arg(ap2, unsigned char *);
1335 arglen = strlen((char *)argp);
1336 PUT_32BIT(p, arglen);
1337 memcpy(p + 4, argp, arglen);
1341 bn = va_arg(ap2, Bignum);
1342 p += ssh1_write_bignum(p, bn);
1348 static void send_packet(Ssh ssh, int pkttype, ...)
1351 va_start(ap1, pkttype);
1352 va_start(ap2, pkttype);
1353 construct_packet(ssh, pkttype, ap1, ap2);
1357 static void defer_packet(Ssh ssh, int pkttype, ...)
1360 va_start(ap1, pkttype);
1361 va_start(ap2, pkttype);
1362 construct_packet(ssh, pkttype, ap1, ap2);
1366 static int ssh_versioncmp(char *a, char *b)
1369 unsigned long av, bv;
1371 av = strtoul(a, &ae, 10);
1372 bv = strtoul(b, &be, 10);
1374 return (av < bv ? -1 : +1);
1379 av = strtoul(ae, &ae, 10);
1380 bv = strtoul(be, &be, 10);
1382 return (av < bv ? -1 : +1);
1387 * Utility routines for putting an SSH-protocol `string' and
1388 * `uint32' into a SHA state.
1391 static void sha_string(SHA_State * s, void *str, int len)
1393 unsigned char lenblk[4];
1394 PUT_32BIT(lenblk, len);
1395 SHA_Bytes(s, lenblk, 4);
1396 SHA_Bytes(s, str, len);
1399 static void sha_uint32(SHA_State * s, unsigned i)
1401 unsigned char intblk[4];
1402 PUT_32BIT(intblk, i);
1403 SHA_Bytes(s, intblk, 4);
1407 * SSH2 packet construction functions.
1409 static void ssh2_pkt_ensure(Ssh ssh, int length)
1411 if (ssh->pktout.maxlen < length) {
1412 ssh->pktout.maxlen = length + 256;
1413 ssh->pktout.data = sresize(ssh->pktout.data,
1414 ssh->pktout.maxlen + APIEXTRA,
1416 if (!ssh->pktout.data)
1417 fatalbox("Out of memory");
1420 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1422 ssh->pktout.length += len;
1423 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1424 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1426 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1428 ssh2_pkt_adddata(ssh, &byte, 1);
1430 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1432 ssh->pktout.length = 5;
1433 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1435 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1437 ssh2_pkt_adddata(ssh, &value, 1);
1439 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1442 PUT_32BIT(x, value);
1443 ssh2_pkt_adddata(ssh, x, 4);
1445 static void ssh2_pkt_addstring_start(Ssh ssh)
1447 ssh2_pkt_adduint32(ssh, 0);
1448 ssh->pktout.savedpos = ssh->pktout.length;
1450 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1452 ssh2_pkt_adddata(ssh, data, strlen(data));
1453 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1454 ssh->pktout.length - ssh->pktout.savedpos);
1456 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1458 ssh2_pkt_adddata(ssh, data, len);
1459 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1460 ssh->pktout.length - ssh->pktout.savedpos);
1462 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1464 ssh2_pkt_addstring_start(ssh);
1465 ssh2_pkt_addstring_str(ssh, data);
1467 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1470 int i, n = (bignum_bitcount(b) + 7) / 8;
1471 p = snewn(n + 1, unsigned char);
1473 fatalbox("out of memory");
1475 for (i = 1; i <= n; i++)
1476 p[i] = bignum_byte(b, n - i);
1478 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1480 memmove(p, p + i, n + 1 - i);
1484 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1488 p = ssh2_mpint_fmt(b, &len);
1489 ssh2_pkt_addstring_start(ssh);
1490 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1495 * Construct an SSH2 final-form packet: compress it, encrypt it,
1496 * put the MAC on it. Final packet, ready to be sent, is stored in
1497 * ssh->pktout.data. Total length is returned.
1499 static int ssh2_pkt_construct(Ssh ssh)
1501 int cipherblk, maclen, padding, i;
1504 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1505 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1506 ssh->pktout.data + 6, ssh->pktout.length - 6);
1509 * Compress packet payload.
1512 unsigned char *newpayload;
1515 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1516 ssh->pktout.length - 5,
1517 &newpayload, &newlen)) {
1518 ssh->pktout.length = 5;
1519 ssh2_pkt_adddata(ssh, newpayload, newlen);
1525 * Add padding. At least four bytes, and must also bring total
1526 * length (minus MAC) up to a multiple of the block size.
1528 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1529 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1532 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1533 maclen = ssh->csmac ? ssh->csmac->len : 0;
1534 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1535 ssh->pktout.data[4] = padding;
1536 for (i = 0; i < padding; i++)
1537 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1538 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1540 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1541 ssh->pktout.length + padding,
1542 ssh->v2_outgoing_sequence);
1543 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1546 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1547 ssh->pktout.data, ssh->pktout.length + padding);
1549 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1550 return ssh->pktout.length + padding + maclen;
1554 * Construct and send an SSH2 packet immediately.
1556 static void ssh2_pkt_send(Ssh ssh)
1560 len = ssh2_pkt_construct(ssh);
1561 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1562 if (backlog > SSH_MAX_BACKLOG)
1563 ssh_throttle_all(ssh, 1, backlog);
1567 * Construct an SSH2 packet and add it to a deferred data block.
1568 * Useful for sending multiple packets in a single sk_write() call,
1569 * to prevent a traffic-analysing listener from being able to work
1570 * out the length of any particular packet (such as the password
1573 * Note that because SSH2 sequence-numbers its packets, this can
1574 * NOT be used as an m4-style `defer' allowing packets to be
1575 * constructed in one order and sent in another.
1577 static void ssh2_pkt_defer(Ssh ssh)
1579 int len = ssh2_pkt_construct(ssh);
1580 if (ssh->deferred_len + len > ssh->deferred_size) {
1581 ssh->deferred_size = ssh->deferred_len + len + 128;
1582 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1586 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1587 ssh->deferred_len += len;
1591 * Send the whole deferred data block constructed by
1592 * ssh2_pkt_defer() or SSH1's defer_packet().
1594 static void ssh_pkt_defersend(Ssh ssh)
1597 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1599 ssh->deferred_len = ssh->deferred_size = 0;
1600 sfree(ssh->deferred_send_data);
1601 ssh->deferred_send_data = NULL;
1602 if (backlog > SSH_MAX_BACKLOG)
1603 ssh_throttle_all(ssh, 1, backlog);
1607 void bndebug(char *string, Bignum b)
1611 p = ssh2_mpint_fmt(b, &len);
1612 debug(("%s", string));
1613 for (i = 0; i < len; i++)
1614 debug((" %02x", p[i]));
1620 static void sha_mpint(SHA_State * s, Bignum b)
1624 p = ssh2_mpint_fmt(b, &len);
1625 sha_string(s, p, len);
1630 * SSH2 packet decode functions.
1632 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1634 unsigned long value;
1635 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1636 return 0; /* arrgh, no way to decline (FIXME?) */
1637 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1638 ssh->pktin.savedpos += 4;
1641 static int ssh2_pkt_getbool(Ssh ssh)
1643 unsigned long value;
1644 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1645 return 0; /* arrgh, no way to decline (FIXME?) */
1646 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1647 ssh->pktin.savedpos++;
1650 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1655 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1657 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1661 ssh->pktin.savedpos += 4;
1662 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1664 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1665 ssh->pktin.savedpos += *length;
1667 static Bignum ssh2_pkt_getmp(Ssh ssh)
1673 ssh2_pkt_getstring(ssh, &p, &length);
1677 bombout(("internal error: Can't handle negative mpints"));
1680 b = bignum_from_bytes((unsigned char *)p, length);
1685 * Helper function to add an SSH2 signature blob to a packet.
1686 * Expects to be shown the public key blob as well as the signature
1687 * blob. Normally works just like ssh2_pkt_addstring, but will
1688 * fiddle with the signature packet if necessary for
1689 * BUG_SSH2_RSA_PADDING.
1691 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1692 void *sigblob_v, int sigblob_len)
1694 unsigned char *pkblob = (unsigned char *)pkblob_v;
1695 unsigned char *sigblob = (unsigned char *)sigblob_v;
1697 /* dmemdump(pkblob, pkblob_len); */
1698 /* dmemdump(sigblob, sigblob_len); */
1701 * See if this is in fact an ssh-rsa signature and a buggy
1702 * server; otherwise we can just do this the easy way.
1704 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1705 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1706 int pos, len, siglen;
1709 * Find the byte length of the modulus.
1712 pos = 4+7; /* skip over "ssh-rsa" */
1713 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1714 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1715 pos += 4; /* find modulus itself */
1716 while (len > 0 && pkblob[pos] == 0)
1718 /* debug(("modulus length is %d\n", len)); */
1721 * Now find the signature integer.
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 siglen = GET_32BIT(sigblob+pos);
1725 /* debug(("signature length is %d\n", siglen)); */
1727 if (len != siglen) {
1728 unsigned char newlen[4];
1729 ssh2_pkt_addstring_start(ssh);
1730 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1731 /* dmemdump(sigblob, pos); */
1732 pos += 4; /* point to start of actual sig */
1733 PUT_32BIT(newlen, len);
1734 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1735 /* dmemdump(newlen, 4); */
1737 while (len-- > siglen) {
1738 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1739 /* dmemdump(newlen, 1); */
1741 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1742 /* dmemdump(sigblob+pos, siglen); */
1746 /* Otherwise fall through and do it the easy way. */
1749 ssh2_pkt_addstring_start(ssh);
1750 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1754 * Examine the remote side's version string and compare it against
1755 * a list of known buggy implementations.
1757 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1759 char *imp; /* pointer to implementation part */
1761 imp += strcspn(imp, "-");
1763 imp += strcspn(imp, "-");
1766 ssh->remote_bugs = 0;
1768 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1769 (ssh->cfg.sshbug_ignore1 == AUTO &&
1770 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1771 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1772 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1774 * These versions don't support SSH1_MSG_IGNORE, so we have
1775 * to use a different defence against password length
1778 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1779 logevent("We believe remote version has SSH1 ignore bug");
1782 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1783 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1784 (!strcmp(imp, "Cisco-1.25")))) {
1786 * These versions need a plain password sent; they can't
1787 * handle having a null and a random length of data after
1790 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1791 logevent("We believe remote version needs a plain SSH1 password");
1794 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_rsa1 == AUTO &&
1796 (!strcmp(imp, "Cisco-1.25")))) {
1798 * These versions apparently have no clue whatever about
1799 * RSA authentication and will panic and die if they see
1800 * an AUTH_RSA message.
1802 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1803 logevent("We believe remote version can't handle RSA authentication");
1806 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1807 (ssh->cfg.sshbug_hmac2 == AUTO &&
1808 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1809 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1810 wc_match("2.1 *", imp)))) {
1812 * These versions have the HMAC bug.
1814 ssh->remote_bugs |= BUG_SSH2_HMAC;
1815 logevent("We believe remote version has SSH2 HMAC bug");
1818 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1820 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1822 * These versions have the key-derivation bug (failing to
1823 * include the literal shared secret in the hashes that
1824 * generate the keys).
1826 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1827 logevent("We believe remote version has SSH2 key-derivation bug");
1830 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1831 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1832 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1833 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1835 * These versions have the SSH2 RSA padding bug.
1837 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1838 logevent("We believe remote version has SSH2 RSA padding bug");
1841 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1842 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1843 wc_match("OpenSSH_2.[0-2]*", imp))) {
1845 * These versions have the SSH2 session-ID bug in
1846 * public-key authentication.
1848 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1849 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1852 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1854 * User specified the SSH2 DH GEX bug.
1856 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1857 logevent("We believe remote version has SSH2 DH group exchange bug");
1861 static int do_ssh_init(Ssh ssh, unsigned char c)
1863 struct do_ssh_init_state {
1871 crState(do_ssh_init_state);
1873 crBegin(ssh->do_ssh_init_crstate);
1875 /* Search for the string "SSH-" in the input. */
1878 static const int transS[] = { 1, 2, 2, 1 };
1879 static const int transH[] = { 0, 0, 3, 0 };
1880 static const int transminus[] = { 0, 0, 0, -1 };
1882 s->i = transS[s->i];
1884 s->i = transH[s->i];
1886 s->i = transminus[s->i];
1891 crReturn(1); /* get another character */
1895 s->vstring = snewn(s->vstrsize, char);
1896 strcpy(s->vstring, "SSH-");
1900 crReturn(1); /* get another char */
1901 if (s->vslen >= s->vstrsize - 1) {
1903 s->vstring = sresize(s->vstring, s->vstrsize, char);
1905 s->vstring[s->vslen++] = c;
1908 s->version[s->i] = '\0';
1910 } else if (s->i < sizeof(s->version) - 1)
1911 s->version[s->i++] = c;
1912 } else if (c == '\012')
1916 ssh->agentfwd_enabled = FALSE;
1917 ssh->rdpkt2_state.incoming_sequence = 0;
1919 s->vstring[s->vslen] = 0;
1920 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1923 vlog = snewn(20 + s->vslen, char);
1924 sprintf(vlog, "Server version: %s", s->vstring);
1928 ssh_detect_bugs(ssh, s->vstring);
1931 * Decide which SSH protocol version to support.
1934 /* Anything strictly below "2.0" means protocol 1 is supported. */
1935 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1936 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1937 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1939 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1940 bombout(("SSH protocol version 1 required by user but not provided by server"));
1943 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1944 bombout(("SSH protocol version 2 required by user but not provided by server"));
1948 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1952 char verstring[80], vlog[100];
1953 sprintf(verstring, "SSH-2.0-%s", sshver);
1954 SHA_Init(&ssh->exhashbase);
1956 * Hash our version string and their version string.
1958 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1959 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1960 sprintf(vlog, "We claim version: %s", verstring);
1962 strcat(verstring, "\012");
1963 logevent("Using SSH protocol version 2");
1964 sk_write(ssh->s, verstring, strlen(verstring));
1965 ssh->protocol = ssh2_protocol;
1967 ssh->s_rdpkt = ssh2_rdpkt;
1972 char verstring[80], vlog[100];
1973 sprintf(verstring, "SSH-%s-%s",
1974 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1976 sprintf(vlog, "We claim version: %s", verstring);
1978 strcat(verstring, "\012");
1980 logevent("Using SSH protocol version 1");
1981 sk_write(ssh->s, verstring, strlen(verstring));
1982 ssh->protocol = ssh1_protocol;
1984 ssh->s_rdpkt = ssh1_rdpkt;
1986 update_specials_menu(ssh->frontend);
1987 ssh->state = SSH_STATE_BEFORE_SIZE;
1994 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1996 crBegin(ssh->ssh_gotdata_crstate);
1999 * To begin with, feed the characters one by one to the
2000 * protocol initialisation / selection function do_ssh_init().
2001 * When that returns 0, we're done with the initial greeting
2002 * exchange and can move on to packet discipline.
2005 int ret; /* need not be kept across crReturn */
2007 crReturnV; /* more data please */
2008 ret = do_ssh_init(ssh, *data);
2016 * We emerge from that loop when the initial negotiation is
2017 * over and we have selected an s_rdpkt function. Now pass
2018 * everything to s_rdpkt, and then pass the resulting packets
2019 * to the proper protocol handler.
2024 while (datalen > 0) {
2025 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2026 if (ssh->state == SSH_STATE_CLOSED) {
2029 ssh->protocol(ssh, NULL, 0, 1);
2030 if (ssh->state == SSH_STATE_CLOSED) {
2040 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2043 Ssh ssh = (Ssh) plug;
2044 ssh->state = SSH_STATE_CLOSED;
2050 /* A socket error has occurred. */
2051 logevent(error_msg);
2052 connection_fatal(ssh->frontend, error_msg);
2054 /* Otherwise, the remote side closed the connection normally. */
2059 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2061 Ssh ssh = (Ssh) plug;
2062 ssh_gotdata(ssh, (unsigned char *)data, len);
2063 if (ssh->state == SSH_STATE_CLOSED) {
2073 static void ssh_sent(Plug plug, int bufsize)
2075 Ssh ssh = (Ssh) plug;
2077 * If the send backlog on the SSH socket itself clears, we
2078 * should unthrottle the whole world if it was throttled.
2080 if (bufsize < SSH_MAX_BACKLOG)
2081 ssh_throttle_all(ssh, 0, bufsize);
2085 * Connect to specified host and port.
2086 * Returns an error message, or NULL on success.
2087 * Also places the canonical host name into `realhost'. It must be
2088 * freed by the caller.
2090 static char *connect_to_host(Ssh ssh, char *host, int port,
2091 char **realhost, int nodelay)
2093 static const struct plug_function_table fn_table = {
2103 ssh->savedhost = snewn(1 + strlen(host), char);
2104 if (!ssh->savedhost)
2105 fatalbox("Out of memory");
2106 strcpy(ssh->savedhost, host);
2109 port = 22; /* default ssh port */
2110 ssh->savedport = port;
2115 logeventf(ssh, "Looking up host \"%s\"", host);
2116 addr = name_lookup(host, port, realhost, &ssh->cfg);
2117 if ((err = sk_addr_error(addr)) != NULL)
2125 sk_getaddr(addr, addrbuf, 100);
2126 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2128 ssh->fn = &fn_table;
2129 ssh->s = new_connection(addr, *realhost, port,
2130 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2131 if ((err = sk_socket_error(ssh->s)) != NULL) {
2140 * Throttle or unthrottle the SSH connection.
2142 static void ssh1_throttle(Ssh ssh, int adjust)
2144 int old_count = ssh->v1_throttle_count;
2145 ssh->v1_throttle_count += adjust;
2146 assert(ssh->v1_throttle_count >= 0);
2147 if (ssh->v1_throttle_count && !old_count) {
2148 sk_set_frozen(ssh->s, 1);
2149 } else if (!ssh->v1_throttle_count && old_count) {
2150 sk_set_frozen(ssh->s, 0);
2155 * Throttle or unthrottle _all_ local data streams (for when sends
2156 * on the SSH connection itself back up).
2158 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2161 struct ssh_channel *c;
2163 if (enable == ssh->throttled_all)
2165 ssh->throttled_all = enable;
2166 ssh->overall_bufsize = bufsize;
2169 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2171 case CHAN_MAINSESSION:
2173 * This is treated separately, outside the switch.
2177 x11_override_throttle(c->u.x11.s, enable);
2180 /* Agent channels require no buffer management. */
2183 pfd_override_throttle(c->u.x11.s, enable);
2190 * Username and password input, abstracted off into routines
2191 * reusable in several places - even between SSH1 and SSH2.
2194 /* Set up a username or password input loop on a given buffer. */
2195 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2197 ssh->userpass_input_buffer = buffer;
2198 ssh->userpass_input_buflen = buflen;
2199 ssh->userpass_input_bufpos = 0;
2200 ssh->userpass_input_echo = echo;
2204 * Process some terminal data in the course of username/password
2205 * input. Returns >0 for success (line of input returned in
2206 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2207 * for inconclusive (keep waiting for more input please).
2209 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2214 switch (c = *in++) {
2217 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2218 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2223 if (ssh->userpass_input_bufpos > 0) {
2224 if (ssh->userpass_input_echo)
2225 c_write_str(ssh, "\b \b");
2226 ssh->userpass_input_bufpos--;
2231 while (ssh->userpass_input_bufpos > 0) {
2232 if (ssh->userpass_input_echo)
2233 c_write_str(ssh, "\b \b");
2234 ssh->userpass_input_bufpos--;
2243 * This simplistic check for printability is disabled
2244 * when we're doing password input, because some people
2245 * have control characters in their passwords.o
2247 if ((!ssh->userpass_input_echo ||
2248 (c >= ' ' && c <= '~') ||
2249 ((unsigned char) c >= 160))
2250 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2251 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2252 if (ssh->userpass_input_echo)
2253 c_write(ssh, &c, 1);
2262 * Handle the key exchange and user authentication phases.
2264 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2267 unsigned char cookie[8];
2268 struct RSAKey servkey, hostkey;
2269 struct MD5Context md5c;
2270 struct do_ssh1_login_state {
2272 unsigned char *rsabuf, *keystr1, *keystr2;
2273 unsigned long supported_ciphers_mask, supported_auths_mask;
2274 int tried_publickey, tried_agent;
2275 int tis_auth_refused, ccard_auth_refused;
2276 unsigned char session_id[16];
2279 void *publickey_blob;
2280 int publickey_bloblen;
2286 unsigned char request[5], *response, *p;
2295 crState(do_ssh1_login_state);
2297 crBegin(ssh->do_ssh1_login_crstate);
2302 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2303 bombout(("Public key packet not received"));
2307 logevent("Received public keys");
2309 memcpy(cookie, ssh->pktin.body, 8);
2311 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2312 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2315 * Log the host key fingerprint.
2319 logevent("Host key fingerprint is:");
2320 strcpy(logmsg, " ");
2321 hostkey.comment = NULL;
2322 rsa_fingerprint(logmsg + strlen(logmsg),
2323 sizeof(logmsg) - strlen(logmsg), &hostkey);
2327 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2328 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2329 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2331 ssh->v1_local_protoflags =
2332 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2333 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2336 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2337 MD5Update(&md5c, s->keystr1, servkey.bytes);
2338 MD5Update(&md5c, ssh->pktin.body, 8);
2339 MD5Final(s->session_id, &md5c);
2341 for (i = 0; i < 32; i++)
2342 ssh->session_key[i] = random_byte();
2344 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2346 s->rsabuf = snewn(s->len, unsigned char);
2348 fatalbox("Out of memory");
2351 * Verify the host key.
2355 * First format the key into a string.
2357 int len = rsastr_len(&hostkey);
2358 char fingerprint[100];
2359 char *keystr = snewn(len, char);
2361 fatalbox("Out of memory");
2362 rsastr_fmt(keystr, &hostkey);
2363 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2364 verify_ssh_host_key(ssh->frontend,
2365 ssh->savedhost, ssh->savedport, "rsa", keystr,
2370 for (i = 0; i < 32; i++) {
2371 s->rsabuf[i] = ssh->session_key[i];
2373 s->rsabuf[i] ^= s->session_id[i];
2376 if (hostkey.bytes > servkey.bytes) {
2377 rsaencrypt(s->rsabuf, 32, &servkey);
2378 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2380 rsaencrypt(s->rsabuf, 32, &hostkey);
2381 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2384 logevent("Encrypted session key");
2387 int cipher_chosen = 0, warn = 0;
2388 char *cipher_string = NULL;
2390 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2391 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2392 if (next_cipher == CIPHER_WARN) {
2393 /* If/when we choose a cipher, warn about it */
2395 } else if (next_cipher == CIPHER_AES) {
2396 /* XXX Probably don't need to mention this. */
2397 logevent("AES not supported in SSH1, skipping");
2399 switch (next_cipher) {
2400 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2401 cipher_string = "3DES"; break;
2402 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2403 cipher_string = "Blowfish"; break;
2404 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2405 cipher_string = "single-DES"; break;
2407 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2411 if (!cipher_chosen) {
2412 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2413 bombout(("Server violates SSH 1 protocol by not "
2414 "supporting 3DES encryption"));
2416 /* shouldn't happen */
2417 bombout(("No supported ciphers found"));
2421 /* Warn about chosen cipher if necessary. */
2423 askcipher(ssh->frontend, cipher_string, 0);
2426 switch (s->cipher_type) {
2427 case SSH_CIPHER_3DES:
2428 logevent("Using 3DES encryption");
2430 case SSH_CIPHER_DES:
2431 logevent("Using single-DES encryption");
2433 case SSH_CIPHER_BLOWFISH:
2434 logevent("Using Blowfish encryption");
2438 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2439 PKT_CHAR, s->cipher_type,
2440 PKT_DATA, cookie, 8,
2441 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2442 PKT_DATA, s->rsabuf, s->len,
2443 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2445 logevent("Trying to enable encryption...");
2449 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2450 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2452 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2453 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2454 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2456 ssh->crcda_ctx = crcda_make_context();
2457 logevent("Installing CRC compensation attack detector");
2461 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2462 bombout(("Encryption not successfully enabled"));
2466 logevent("Successfully started encryption");
2470 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2471 if (ssh_get_line && !ssh_getline_pw_only) {
2472 if (!ssh_get_line("login as: ",
2473 s->username, sizeof(s->username), FALSE)) {
2475 * get_line failed to get a username.
2478 logevent("No username provided. Abandoning session.");
2479 ssh_closing((Plug)ssh, NULL, 0, 0);
2483 int ret; /* need not be kept over crReturn */
2484 c_write_str(ssh, "login as: ");
2487 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2489 crWaitUntil(!ispkt);
2490 ret = process_userpass_input(ssh, in, inlen);
2494 c_write_str(ssh, "\r\n");
2497 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2498 s->username[sizeof(s->username)-1] = '\0';
2501 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2503 char userlog[22 + sizeof(s->username)];
2504 sprintf(userlog, "Sent username \"%s\"", s->username);
2506 if (flags & FLAG_INTERACTIVE &&
2507 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2508 strcat(userlog, "\r\n");
2509 c_write_str(ssh, userlog);
2516 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2517 /* We must not attempt PK auth. Pretend we've already tried it. */
2518 s->tried_publickey = s->tried_agent = 1;
2520 s->tried_publickey = s->tried_agent = 0;
2522 s->tis_auth_refused = s->ccard_auth_refused = 0;
2523 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2524 if (!filename_is_null(ssh->cfg.keyfile)) {
2525 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2526 &s->publickey_blob, &s->publickey_bloblen))
2527 s->publickey_blob = NULL;
2529 s->publickey_blob = NULL;
2531 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2532 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2534 if (agent_exists() && !s->tried_agent) {
2536 * Attempt RSA authentication using Pageant.
2542 logevent("Pageant is running. Requesting keys.");
2544 /* Request the keys held by the agent. */
2545 PUT_32BIT(s->request, 1);
2546 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2547 agent_query(s->request, 5, &r, &s->responselen);
2548 s->response = (unsigned char *) r;
2549 if (s->response && s->responselen >= 5 &&
2550 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2551 s->p = s->response + 5;
2552 s->nkeys = GET_32BIT(s->p);
2556 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2559 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2562 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2565 if (s->publickey_blob &&
2566 !memcmp(s->p, s->publickey_blob,
2567 s->publickey_bloblen)) {
2568 logevent("This key matches configured key file");
2569 s->tried_publickey = 1;
2572 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2573 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2574 s->commentlen = GET_32BIT(s->p);
2576 s->commentp = (char *)s->p;
2577 s->p += s->commentlen;
2578 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2579 PKT_BIGNUM, s->key.modulus, PKT_END);
2581 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2582 logevent("Key refused");
2585 logevent("Received RSA challenge");
2586 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2588 char *agentreq, *q, *ret;
2591 len = 1 + 4; /* message type, bit count */
2592 len += ssh1_bignum_length(s->key.exponent);
2593 len += ssh1_bignum_length(s->key.modulus);
2594 len += ssh1_bignum_length(s->challenge);
2595 len += 16; /* session id */
2596 len += 4; /* response format */
2597 agentreq = snewn(4 + len, char);
2598 PUT_32BIT(agentreq, len);
2600 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2601 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2603 q += ssh1_write_bignum(q, s->key.exponent);
2604 q += ssh1_write_bignum(q, s->key.modulus);
2605 q += ssh1_write_bignum(q, s->challenge);
2606 memcpy(q, s->session_id, 16);
2608 PUT_32BIT(q, 1); /* response format */
2609 agent_query(agentreq, len + 4, &vret, &retlen);
2613 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2614 logevent("Sending Pageant's response");
2615 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2616 PKT_DATA, ret + 5, 16,
2620 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2622 ("Pageant's response accepted");
2623 if (flags & FLAG_VERBOSE) {
2624 c_write_str(ssh, "Authenticated using"
2626 c_write(ssh, s->commentp,
2628 c_write_str(ssh, "\" from agent\r\n");
2633 ("Pageant's response not accepted");
2636 ("Pageant failed to answer challenge");
2640 logevent("No reply received from Pageant");
2643 freebn(s->key.exponent);
2644 freebn(s->key.modulus);
2645 freebn(s->challenge);
2653 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2654 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2656 if (ssh->cfg.try_tis_auth &&
2657 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2658 !s->tis_auth_refused) {
2659 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2660 logevent("Requested TIS authentication");
2661 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2663 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2664 logevent("TIS authentication declined");
2665 if (flags & FLAG_INTERACTIVE)
2666 c_write_str(ssh, "TIS authentication refused.\r\n");
2667 s->tis_auth_refused = 1;
2670 int challengelen = GET_32BIT(ssh->pktin.body);
2671 logevent("Received TIS challenge");
2672 if (challengelen > sizeof(s->prompt) - 1)
2673 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2674 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2675 /* Prompt heuristic comes from OpenSSH */
2676 strncpy(s->prompt + challengelen,
2677 memchr(s->prompt, '\n', challengelen) ?
2678 "": "\r\nResponse: ",
2679 (sizeof s->prompt) - challengelen);
2680 s->prompt[(sizeof s->prompt) - 1] = '\0';
2683 if (ssh->cfg.try_tis_auth &&
2684 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2685 !s->ccard_auth_refused) {
2686 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2687 logevent("Requested CryptoCard authentication");
2688 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2690 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2691 logevent("CryptoCard authentication declined");
2692 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2693 s->ccard_auth_refused = 1;
2696 int challengelen = GET_32BIT(ssh->pktin.body);
2697 logevent("Received CryptoCard challenge");
2698 if (challengelen > sizeof(s->prompt) - 1)
2699 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2700 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2701 strncpy(s->prompt + challengelen,
2702 memchr(s->prompt, '\n', challengelen) ?
2703 "" : "\r\nResponse: ",
2704 sizeof(s->prompt) - challengelen);
2705 s->prompt[sizeof(s->prompt) - 1] = '\0';
2708 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2709 sprintf(s->prompt, "%.90s@%.90s's password: ",
2710 s->username, ssh->savedhost);
2712 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2713 char *comment = NULL;
2716 if (flags & FLAG_VERBOSE)
2717 c_write_str(ssh, "Trying public key authentication.\r\n");
2718 logeventf(ssh, "Trying public key \"%s\"",
2719 filename_to_str(&ssh->cfg.keyfile));
2720 type = key_type(&ssh->cfg.keyfile);
2721 if (type != SSH_KEYTYPE_SSH1) {
2722 sprintf(msgbuf, "Key is of wrong type (%s)",
2723 key_type_to_str(type));
2725 c_write_str(ssh, msgbuf);
2726 c_write_str(ssh, "\r\n");
2727 s->tried_publickey = 1;
2730 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2731 if (flags & FLAG_VERBOSE)
2732 c_write_str(ssh, "No passphrase required.\r\n");
2735 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2740 * Show password prompt, having first obtained it via a TIS
2741 * or CryptoCard exchange if we're doing TIS or CryptoCard
2745 if (!ssh_get_line(s->prompt, s->password,
2746 sizeof(s->password), TRUE)) {
2748 * get_line failed to get a password (for example
2749 * because one was supplied on the command line
2750 * which has already failed to work). Terminate.
2752 send_packet(ssh, SSH1_MSG_DISCONNECT,
2753 PKT_STR, "No more passwords available to try",
2755 logevent("Unable to authenticate");
2756 connection_fatal(ssh->frontend, "Unable to authenticate");
2757 ssh_closing((Plug)ssh, NULL, 0, 0);
2761 /* Prompt may have come from server. We've munged it a bit, so
2762 * we know it to be zero-terminated at least once. */
2763 int ret; /* need not be saved over crReturn */
2764 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2767 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2769 crWaitUntil(!ispkt);
2770 ret = process_userpass_input(ssh, in, inlen);
2774 c_write_str(ssh, "\r\n");
2778 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2780 * Try public key authentication with the specified
2783 s->tried_publickey = 1;
2786 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2788 c_write_str(ssh, "Couldn't load private key from ");
2789 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2790 c_write_str(ssh, ".\r\n");
2791 continue; /* go and try password */
2794 c_write_str(ssh, "Wrong passphrase.\r\n");
2795 s->tried_publickey = 0;
2796 continue; /* try again */
2801 * Send a public key attempt.
2803 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2804 PKT_BIGNUM, s->key.modulus, PKT_END);
2807 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2808 c_write_str(ssh, "Server refused our public key.\r\n");
2809 continue; /* go and try password */
2811 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2812 bombout(("Bizarre response to offer of public key"));
2818 unsigned char buffer[32];
2819 Bignum challenge, response;
2821 ssh1_read_bignum(ssh->pktin.body, &challenge);
2822 response = rsadecrypt(challenge, &s->key);
2823 freebn(s->key.private_exponent);/* burn the evidence */
2825 for (i = 0; i < 32; i++) {
2826 buffer[i] = bignum_byte(response, 31 - i);
2830 MD5Update(&md5c, buffer, 32);
2831 MD5Update(&md5c, s->session_id, 16);
2832 MD5Final(buffer, &md5c);
2834 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2835 PKT_DATA, buffer, 16, PKT_END);
2842 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2843 if (flags & FLAG_VERBOSE)
2844 c_write_str(ssh, "Failed to authenticate with"
2845 " our public key.\r\n");
2846 continue; /* go and try password */
2847 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2848 bombout(("Bizarre response to RSA authentication response"));
2852 break; /* we're through! */
2854 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2856 * Defence against traffic analysis: we send a
2857 * whole bunch of packets containing strings of
2858 * different lengths. One of these strings is the
2859 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2860 * The others are all random data in
2861 * SSH1_MSG_IGNORE packets. This way a passive
2862 * listener can't tell which is the password, and
2863 * hence can't deduce the password length.
2865 * Anybody with a password length greater than 16
2866 * bytes is going to have enough entropy in their
2867 * password that a listener won't find it _that_
2868 * much help to know how long it is. So what we'll
2871 * - if password length < 16, we send 15 packets
2872 * containing string lengths 1 through 15
2874 * - otherwise, we let N be the nearest multiple
2875 * of 8 below the password length, and send 8
2876 * packets containing string lengths N through
2877 * N+7. This won't obscure the order of
2878 * magnitude of the password length, but it will
2879 * introduce a bit of extra uncertainty.
2881 * A few servers (the old 1.2.18 through 1.2.22)
2882 * can't deal with SSH1_MSG_IGNORE. For these
2883 * servers, we need an alternative defence. We make
2884 * use of the fact that the password is interpreted
2885 * as a C string: so we can append a NUL, then some
2888 * One server (a Cisco one) can deal with neither
2889 * SSH1_MSG_IGNORE _nor_ a padded password string.
2890 * For this server we are left with no defences
2891 * against password length sniffing.
2893 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2895 * The server can deal with SSH1_MSG_IGNORE, so
2896 * we can use the primary defence.
2898 int bottom, top, pwlen, i;
2901 pwlen = strlen(s->password);
2903 bottom = 0; /* zero length passwords are OK! :-) */
2906 bottom = pwlen & ~7;
2910 assert(pwlen >= bottom && pwlen <= top);
2912 randomstr = snewn(top + 1, char);
2914 for (i = bottom; i <= top; i++) {
2916 defer_packet(ssh, s->pwpkt_type,
2917 PKT_STR, s->password, PKT_END);
2919 for (j = 0; j < i; j++) {
2921 randomstr[j] = random_byte();
2922 } while (randomstr[j] == '\0');
2924 randomstr[i] = '\0';
2925 defer_packet(ssh, SSH1_MSG_IGNORE,
2926 PKT_STR, randomstr, PKT_END);
2929 logevent("Sending password with camouflage packets");
2930 ssh_pkt_defersend(ssh);
2932 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2934 * The server can't deal with SSH1_MSG_IGNORE
2935 * but can deal with padded passwords, so we
2936 * can use the secondary defence.
2942 len = strlen(s->password);
2943 if (len < sizeof(string)) {
2945 strcpy(string, s->password);
2946 len++; /* cover the zero byte */
2947 while (len < sizeof(string)) {
2948 string[len++] = (char) random_byte();
2953 logevent("Sending length-padded password");
2954 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2955 PKT_DATA, ss, len, PKT_END);
2958 * The server has _both_
2959 * BUG_CHOKES_ON_SSH1_IGNORE and
2960 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2961 * therefore nothing we can do.
2964 len = strlen(s->password);
2965 logevent("Sending unpadded password");
2966 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2967 PKT_DATA, s->password, len, PKT_END);
2970 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2973 logevent("Sent password");
2974 memset(s->password, 0, strlen(s->password));
2976 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2977 if (flags & FLAG_VERBOSE)
2978 c_write_str(ssh, "Access denied\r\n");
2979 logevent("Authentication refused");
2980 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2981 bombout(("Strange packet received, type %d", ssh->pktin.type));
2986 logevent("Authentication successful");
2991 void sshfwd_close(struct ssh_channel *c)
2995 if (c && !c->closes) {
2997 * If the channel's remoteid is -1, we have sent
2998 * CHANNEL_OPEN for this channel, but it hasn't even been
2999 * acknowledged by the server. So we must set a close flag
3000 * on it now, and then when the server acks the channel
3001 * open, we can close it then.
3003 if (((int)c->remoteid) != -1) {
3004 if (ssh->version == 1) {
3005 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3008 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3009 ssh2_pkt_adduint32(ssh, c->remoteid);
3013 c->closes = 1; /* sent MSG_CLOSE */
3014 if (c->type == CHAN_X11) {
3016 logevent("Forwarded X11 connection terminated");
3017 } else if (c->type == CHAN_SOCKDATA ||
3018 c->type == CHAN_SOCKDATA_DORMANT) {
3020 logevent("Forwarded port closed");
3025 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3029 if (ssh->version == 1) {
3030 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3031 PKT_INT, c->remoteid,
3032 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3034 * In SSH1 we can return 0 here - implying that forwarded
3035 * connections are never individually throttled - because
3036 * the only circumstance that can cause throttling will be
3037 * the whole SSH connection backing up, in which case
3038 * _everything_ will be throttled as a whole.
3042 ssh2_add_channel_data(c, buf, len);
3043 return ssh2_try_send(c);
3047 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3051 if (ssh->version == 1) {
3052 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3053 c->v.v1.throttling = 0;
3054 ssh1_throttle(ssh, -1);
3057 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3061 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3063 crBegin(ssh->ssh1_protocol_crstate);
3067 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3070 if (ssh->state == SSH_STATE_CLOSED)
3073 if (ssh->cfg.agentfwd && agent_exists()) {
3074 logevent("Requesting agent forwarding");
3075 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3079 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3080 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3081 bombout(("Protocol confusion"));
3083 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3084 logevent("Agent forwarding refused");
3086 logevent("Agent forwarding enabled");
3087 ssh->agentfwd_enabled = TRUE;
3091 if (ssh->cfg.x11_forward) {
3092 char proto[20], data[64];
3093 logevent("Requesting X11 forwarding");
3094 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3095 data, sizeof(data), ssh->cfg.x11_auth);
3096 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3097 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3098 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3099 PKT_STR, proto, PKT_STR, data,
3100 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3103 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3104 PKT_STR, proto, PKT_STR, data, PKT_END);
3109 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3110 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3111 bombout(("Protocol confusion"));
3113 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3114 logevent("X11 forwarding refused");
3116 logevent("X11 forwarding enabled");
3117 ssh->X11_fwd_enabled = TRUE;
3124 int sport,dport,sserv,dserv;
3125 char sports[256], dports[256], saddr[256], host[256];
3127 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3128 /* Add port forwardings. */
3129 ssh->portfwd_strptr = ssh->cfg.portfwd;
3130 while (*ssh->portfwd_strptr) {
3131 type = *ssh->portfwd_strptr++;
3134 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3135 if (*ssh->portfwd_strptr == ':') {
3137 * We've seen a colon in the middle of the
3138 * source port number. This means that
3139 * everything we've seen until now is the
3140 * source _address_, so we'll move it into
3141 * saddr and start sports from the beginning
3144 ssh->portfwd_strptr++;
3146 strcpy(saddr, sports);
3149 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3153 if (*ssh->portfwd_strptr == '\t')
3154 ssh->portfwd_strptr++;
3156 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3157 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3160 if (*ssh->portfwd_strptr == ':')
3161 ssh->portfwd_strptr++;
3163 while (*ssh->portfwd_strptr) {
3164 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3167 ssh->portfwd_strptr++;
3168 dport = atoi(dports);
3172 dport = net_service_lookup(dports);
3174 logeventf(ssh, "Service lookup failed for"
3175 " destination port \"%s\"", dports);
3179 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3181 sport = atoi(sports);
3185 sport = net_service_lookup(sports);
3187 logeventf(ssh, "Service lookup failed for source"
3188 " port \"%s\"", sports);
3191 if (sport && dport) {
3193 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3194 sport, ssh, &ssh->cfg);
3195 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3196 " forwarding to %s:%.*s%.*s%d%.*s",
3197 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3198 (int)(*saddr?1:0), ":",
3199 (int)(sserv ? strlen(sports) : 0), sports,
3200 sserv, "(", sport, sserv, ")",
3202 (int)(dserv ? strlen(dports) : 0), dports,
3203 dserv, "(", dport, dserv, ")");
3204 } else if (type == 'D') {
3205 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3206 sport, ssh, &ssh->cfg);
3207 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3208 " doing SOCKS dynamic forwarding",
3209 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3210 (int)(*saddr?1:0), ":",
3211 (int)(sserv ? strlen(sports) : 0), sports,
3212 sserv, "(", sport, sserv, ")");
3214 struct ssh_rportfwd *pf;
3215 pf = snew(struct ssh_rportfwd);
3216 strcpy(pf->dhost, host);
3220 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3223 if (add234(ssh->rportfwds, pf) != pf) {
3225 "Duplicate remote port forwarding to %s:%d",
3229 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3230 " forward to %s:%.*s%.*s%d%.*s",
3231 (int)(sserv ? strlen(sports) : 0), sports,
3232 sserv, "(", sport, sserv, ")",
3234 (int)(dserv ? strlen(dports) : 0), dports,
3235 dserv, "(", dport, dserv, ")");
3236 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3244 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3245 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3246 bombout(("Protocol confusion"));
3248 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3249 c_write_str(ssh, "Server refused port"
3252 logevent("Remote port forwarding enabled");
3259 if (!ssh->cfg.nopty) {
3260 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3261 PKT_STR, ssh->cfg.termtype,
3262 PKT_INT, ssh->term_height,
3263 PKT_INT, ssh->term_width,
3264 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3265 ssh->state = SSH_STATE_INTERMED;
3269 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3270 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3271 bombout(("Protocol confusion"));
3273 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3274 c_write_str(ssh, "Server refused to allocate pty\r\n");
3275 ssh->editing = ssh->echoing = 1;
3277 logevent("Allocated pty");
3279 ssh->editing = ssh->echoing = 1;
3282 if (ssh->cfg.compression) {
3283 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3287 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3288 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3289 bombout(("Protocol confusion"));
3291 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3292 c_write_str(ssh, "Server refused to compress\r\n");
3294 logevent("Started compression");
3295 ssh->v1_compressing = TRUE;
3296 ssh->cs_comp_ctx = zlib_compress_init();
3297 logevent("Initialised zlib (RFC1950) compression");
3298 ssh->sc_comp_ctx = zlib_decompress_init();
3299 logevent("Initialised zlib (RFC1950) decompression");
3303 * Start the shell or command.
3305 * Special case: if the first-choice command is an SSH2
3306 * subsystem (hence not usable here) and the second choice
3307 * exists, we fall straight back to that.
3310 char *cmd = ssh->cfg.remote_cmd_ptr;
3312 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3313 cmd = ssh->cfg.remote_cmd_ptr2;
3314 ssh->fallback_cmd = TRUE;
3317 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3319 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3320 logevent("Started session");
3323 ssh->state = SSH_STATE_SESSION;
3324 if (ssh->size_needed)
3325 ssh_size(ssh, ssh->term_width, ssh->term_height);
3326 if (ssh->eof_needed)
3327 ssh_special(ssh, TS_EOF);
3330 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3332 ssh->channels = newtree234(ssh_channelcmp);
3336 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3337 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3338 long len = GET_32BIT(ssh->pktin.body);
3340 from_backend(ssh->frontend,
3341 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3342 (char *)(ssh->pktin.body) + 4, len);
3343 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3344 ssh->v1_stdout_throttling = 1;
3345 ssh1_throttle(ssh, +1);
3347 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3348 ssh_closing((Plug)ssh, NULL, 0, 0);
3349 logevent("Received disconnect request");
3351 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3352 /* Remote side is trying to open a channel to talk to our
3353 * X-Server. Give them back a local channel number. */
3354 struct ssh_channel *c;
3356 logevent("Received X11 connect request");
3357 /* Refuse if X11 forwarding is disabled. */
3358 if (!ssh->X11_fwd_enabled) {
3359 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3360 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3361 logevent("Rejected X11 connect request");
3363 c = snew(struct ssh_channel);
3366 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3367 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3368 logevent("opening X11 forward connection failed");
3370 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3371 PKT_INT, GET_32BIT(ssh->pktin.body),
3375 ("opening X11 forward connection succeeded");
3376 c->remoteid = GET_32BIT(ssh->pktin.body);
3377 c->localid = alloc_channel_id(ssh);
3379 c->v.v1.throttling = 0;
3380 c->type = CHAN_X11; /* identify channel type */
3381 add234(ssh->channels, c);
3382 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3383 PKT_INT, c->remoteid, PKT_INT,
3384 c->localid, PKT_END);
3385 logevent("Opened X11 forward channel");
3388 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3389 /* Remote side is trying to open a channel to talk to our
3390 * agent. Give them back a local channel number. */
3391 struct ssh_channel *c;
3393 /* Refuse if agent forwarding is disabled. */
3394 if (!ssh->agentfwd_enabled) {
3395 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3396 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3398 c = snew(struct ssh_channel);
3400 c->remoteid = GET_32BIT(ssh->pktin.body);
3401 c->localid = alloc_channel_id(ssh);
3403 c->v.v1.throttling = 0;
3404 c->type = CHAN_AGENT; /* identify channel type */
3405 c->u.a.lensofar = 0;
3406 add234(ssh->channels, c);
3407 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3408 PKT_INT, c->remoteid, PKT_INT, c->localid,
3411 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3412 /* Remote side is trying to open a channel to talk to a
3413 * forwarded port. Give them back a local channel number. */
3414 struct ssh_channel *c;
3415 struct ssh_rportfwd pf;
3417 char host[256], buf[1024];
3419 c = snew(struct ssh_channel);
3422 hostsize = GET_32BIT(ssh->pktin.body+4);
3423 for (h = host, p = (char *)(ssh->pktin.body+8);
3424 hostsize != 0; hostsize--) {
3425 if (h+1 < host+sizeof(host))
3430 port = GET_32BIT(p);
3432 strcpy(pf.dhost, host);
3435 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3436 sprintf(buf, "Rejected remote port open request for %s:%d",
3439 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3440 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3442 sprintf(buf, "Received remote port open request for %s:%d",
3445 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3448 sprintf(buf, "Port open failed: %s", e);
3451 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3452 PKT_INT, GET_32BIT(ssh->pktin.body),
3455 c->remoteid = GET_32BIT(ssh->pktin.body);
3456 c->localid = alloc_channel_id(ssh);
3458 c->v.v1.throttling = 0;
3459 c->type = CHAN_SOCKDATA; /* identify channel type */
3460 add234(ssh->channels, c);
3461 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3462 PKT_INT, c->remoteid, PKT_INT,
3463 c->localid, PKT_END);
3464 logevent("Forwarded port opened successfully");
3468 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3469 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3470 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3471 struct ssh_channel *c;
3473 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3474 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3475 c->remoteid = localid;
3476 c->type = CHAN_SOCKDATA;
3477 c->v.v1.throttling = 0;
3478 pfd_confirm(c->u.pfd.s);
3481 if (c && c->closes) {
3483 * We have a pending close on this channel,
3484 * which we decided on before the server acked
3485 * the channel open. So now we know the
3486 * remoteid, we can close it again.
3488 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3489 PKT_INT, c->remoteid, PKT_END);
3492 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3493 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3494 struct ssh_channel *c;
3496 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3497 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3498 logevent("Forwarded connection refused by server");
3499 pfd_close(c->u.pfd.s);
3500 del234(ssh->channels, c);
3504 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3505 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3506 /* Remote side closes a channel. */
3507 unsigned i = GET_32BIT(ssh->pktin.body);
3508 struct ssh_channel *c;
3509 c = find234(ssh->channels, &i, ssh_channelfind);
3510 if (c && ((int)c->remoteid) != -1) {
3513 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3515 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3516 logevent("Forwarded X11 connection terminated");
3517 assert(c->u.x11.s != NULL);
3518 x11_close(c->u.x11.s);
3521 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3522 logevent("Forwarded port closed");
3523 assert(c->u.pfd.s != NULL);
3524 pfd_close(c->u.pfd.s);
3528 c->closes |= (closetype << 2); /* seen this message */
3529 if (!(c->closes & closetype)) {
3530 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3532 c->closes |= closetype; /* sent it too */
3535 if (c->closes == 15) {
3536 del234(ssh->channels, c);
3540 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3541 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3542 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3545 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3546 /* Data sent down one of our channels. */
3547 int i = GET_32BIT(ssh->pktin.body);
3548 int len = GET_32BIT(ssh->pktin.body + 4);
3549 unsigned char *p = ssh->pktin.body + 8;
3550 struct ssh_channel *c;
3551 c = find234(ssh->channels, &i, ssh_channelfind);
3556 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3559 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3562 /* Data for an agent message. Buffer it. */
3564 if (c->u.a.lensofar < 4) {
3565 int l = min(4 - c->u.a.lensofar, len);
3566 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3570 c->u.a.lensofar += l;
3572 if (c->u.a.lensofar == 4) {
3574 4 + GET_32BIT(c->u.a.msglen);
3575 c->u.a.message = snewn(c->u.a.totallen,
3577 memcpy(c->u.a.message, c->u.a.msglen, 4);
3579 if (c->u.a.lensofar >= 4 && len > 0) {
3581 min(c->u.a.totallen - c->u.a.lensofar,
3583 memcpy(c->u.a.message + c->u.a.lensofar, p,
3587 c->u.a.lensofar += l;
3589 if (c->u.a.lensofar == c->u.a.totallen) {
3590 void *reply, *sentreply;
3592 agent_query(c->u.a.message,
3593 c->u.a.totallen, &reply,
3598 /* Fake SSH_AGENT_FAILURE. */
3599 sentreply = "\0\0\0\1\5";
3602 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3603 PKT_INT, c->remoteid,
3605 PKT_DATA, sentreply, replylen,
3609 sfree(c->u.a.message);
3610 c->u.a.lensofar = 0;
3613 bufsize = 0; /* agent channels never back up */
3616 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3617 c->v.v1.throttling = 1;
3618 ssh1_throttle(ssh, +1);
3621 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3622 /* may be from EXEC_SHELL on some servers */
3623 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3624 /* may be from EXEC_SHELL on some servers
3625 * if no pty is available or in other odd cases. Ignore */
3626 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3628 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3629 sprintf(buf, "Server sent command exit status %d",
3632 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3634 * In case `helpful' firewalls or proxies tack
3635 * extra human-readable text on the end of the
3636 * session which we might mistake for another
3637 * encrypted packet, we close the session once
3638 * we've sent EXIT_CONFIRMATION.
3640 ssh_closing((Plug)ssh, NULL, 0, 0);
3643 bombout(("Strange packet received: type %d", ssh->pktin.type));
3648 int len = min(inlen, 512);
3649 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3650 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3661 * Utility routine for decoding comma-separated strings in KEXINIT.
3663 static int in_commasep_string(char *needle, char *haystack, int haylen)
3666 if (!needle || !haystack) /* protect against null pointers */
3668 needlen = strlen(needle);
3671 * Is it at the start of the string?
3673 if (haylen >= needlen && /* haystack is long enough */
3674 !memcmp(needle, haystack, needlen) && /* initial match */
3675 (haylen == needlen || haystack[needlen] == ',')
3676 /* either , or EOS follows */
3680 * If not, search for the next comma and resume after that.
3681 * If no comma found, terminate.
3683 while (haylen > 0 && *haystack != ',')
3684 haylen--, haystack++;
3687 haylen--, haystack++; /* skip over comma itself */
3692 * SSH2 key creation method.
3694 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3695 unsigned char *sessid, char chr,
3696 unsigned char *keyspace)
3699 /* First 20 bytes. */
3701 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3703 SHA_Bytes(&s, H, 20);
3704 SHA_Bytes(&s, &chr, 1);
3705 SHA_Bytes(&s, sessid, 20);
3706 SHA_Final(&s, keyspace);
3707 /* Next 20 bytes. */
3709 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3711 SHA_Bytes(&s, H, 20);
3712 SHA_Bytes(&s, keyspace, 20);
3713 SHA_Final(&s, keyspace + 20);
3717 * Handle the SSH2 transport layer.
3719 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3721 struct do_ssh2_transport_state {
3722 int nbits, pbits, warn;
3723 Bignum p, g, e, f, K;
3724 int kex_init_value, kex_reply_value;
3725 const struct ssh_mac **maclist;
3727 const struct ssh2_cipher *cscipher_tobe;
3728 const struct ssh2_cipher *sccipher_tobe;
3729 const struct ssh_mac *csmac_tobe;
3730 const struct ssh_mac *scmac_tobe;
3731 const struct ssh_compress *cscomp_tobe;
3732 const struct ssh_compress *sccomp_tobe;
3733 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3734 int hostkeylen, siglen;
3735 void *hkey; /* actual host key */
3736 unsigned char exchange_hash[20];
3737 int n_preferred_ciphers;
3738 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3739 const struct ssh_compress *preferred_comp;
3742 crState(do_ssh2_transport_state);
3744 crBegin(ssh->do_ssh2_transport_crstate);
3746 s->cscipher_tobe = s->sccipher_tobe = NULL;
3747 s->csmac_tobe = s->scmac_tobe = NULL;
3748 s->cscomp_tobe = s->sccomp_tobe = NULL;
3756 * Set up the preferred ciphers. (NULL => warn below here)
3758 s->n_preferred_ciphers = 0;
3759 for (i = 0; i < CIPHER_MAX; i++) {
3760 switch (ssh->cfg.ssh_cipherlist[i]) {
3761 case CIPHER_BLOWFISH:
3762 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3765 if (ssh->cfg.ssh2_des_cbc) {
3766 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3770 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3773 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3776 /* Flag for later. Don't bother if it's the last in
3778 if (i < CIPHER_MAX - 1) {
3779 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3787 * Set up preferred compression.
3789 if (ssh->cfg.compression)
3790 s->preferred_comp = &ssh_zlib;
3792 s->preferred_comp = &ssh_comp_none;
3795 * Be prepared to work around the buggy MAC problem.
3797 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3798 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3800 s->maclist = macs, s->nmacs = lenof(macs);
3804 int i, j, cipherstr_started;
3807 * Construct and send our key exchange packet.
3809 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3810 for (i = 0; i < 16; i++)
3811 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3812 /* List key exchange algorithms. */
3813 ssh2_pkt_addstring_start(ssh);
3814 for (i = 0; i < lenof(kex_algs); i++) {
3815 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3816 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3818 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3819 if (i < lenof(kex_algs) - 1)
3820 ssh2_pkt_addstring_str(ssh, ",");
3822 /* List server host key algorithms. */
3823 ssh2_pkt_addstring_start(ssh);
3824 for (i = 0; i < lenof(hostkey_algs); i++) {
3825 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3826 if (i < lenof(hostkey_algs) - 1)
3827 ssh2_pkt_addstring_str(ssh, ",");
3829 /* List client->server encryption algorithms. */
3830 ssh2_pkt_addstring_start(ssh);
3831 cipherstr_started = 0;
3832 for (i = 0; i < s->n_preferred_ciphers; i++) {
3833 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3834 if (!c) continue; /* warning flag */
3835 for (j = 0; j < c->nciphers; j++) {
3836 if (cipherstr_started)
3837 ssh2_pkt_addstring_str(ssh, ",");
3838 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3839 cipherstr_started = 1;
3842 /* List server->client encryption algorithms. */
3843 ssh2_pkt_addstring_start(ssh);
3844 cipherstr_started = 0;
3845 for (i = 0; i < s->n_preferred_ciphers; i++) {
3846 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3847 if (!c) continue; /* warning flag */
3848 for (j = 0; j < c->nciphers; j++) {
3849 if (cipherstr_started)
3850 ssh2_pkt_addstring_str(ssh, ",");
3851 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3852 cipherstr_started = 1;
3855 /* List client->server MAC algorithms. */
3856 ssh2_pkt_addstring_start(ssh);
3857 for (i = 0; i < s->nmacs; i++) {
3858 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3859 if (i < s->nmacs - 1)
3860 ssh2_pkt_addstring_str(ssh, ",");
3862 /* List server->client MAC algorithms. */
3863 ssh2_pkt_addstring_start(ssh);
3864 for (i = 0; i < s->nmacs; i++) {
3865 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3866 if (i < s->nmacs - 1)
3867 ssh2_pkt_addstring_str(ssh, ",");
3869 /* List client->server compression algorithms. */
3870 ssh2_pkt_addstring_start(ssh);
3871 for (i = 0; i < lenof(compressions) + 1; i++) {
3872 const struct ssh_compress *c =
3873 i == 0 ? s->preferred_comp : compressions[i - 1];
3874 ssh2_pkt_addstring_str(ssh, c->name);
3875 if (i < lenof(compressions))
3876 ssh2_pkt_addstring_str(ssh, ",");
3878 /* List server->client compression algorithms. */
3879 ssh2_pkt_addstring_start(ssh);
3880 for (i = 0; i < lenof(compressions) + 1; i++) {
3881 const struct ssh_compress *c =
3882 i == 0 ? s->preferred_comp : compressions[i - 1];
3883 ssh2_pkt_addstring_str(ssh, c->name);
3884 if (i < lenof(compressions))
3885 ssh2_pkt_addstring_str(ssh, ",");
3887 /* List client->server languages. Empty list. */
3888 ssh2_pkt_addstring_start(ssh);
3889 /* List server->client languages. Empty list. */
3890 ssh2_pkt_addstring_start(ssh);
3891 /* First KEX packet does _not_ follow, because we're not that brave. */
3892 ssh2_pkt_addbool(ssh, FALSE);
3894 ssh2_pkt_adduint32(ssh, 0);
3897 ssh->exhash = ssh->exhashbase;
3898 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3904 if (ssh->pktin.length > 5)
3905 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3908 * Now examine the other side's KEXINIT to see what we're up
3915 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3916 bombout(("expected key exchange packet from server"));
3920 ssh->hostkey = NULL;
3921 s->cscipher_tobe = NULL;
3922 s->sccipher_tobe = NULL;
3923 s->csmac_tobe = NULL;
3924 s->scmac_tobe = NULL;
3925 s->cscomp_tobe = NULL;
3926 s->sccomp_tobe = NULL;
3927 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3928 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3929 for (i = 0; i < lenof(kex_algs); i++) {
3930 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3931 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3933 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3934 ssh->kex = kex_algs[i];
3938 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3939 for (i = 0; i < lenof(hostkey_algs); i++) {
3940 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3941 ssh->hostkey = hostkey_algs[i];
3945 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3947 for (i = 0; i < s->n_preferred_ciphers; i++) {
3948 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3952 for (j = 0; j < c->nciphers; j++) {
3953 if (in_commasep_string(c->list[j]->name, str, len)) {
3954 s->cscipher_tobe = c->list[j];
3959 if (s->cscipher_tobe) {
3961 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3965 if (!s->cscipher_tobe) {
3966 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
3967 str ? str : "(null)"));
3971 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3973 for (i = 0; i < s->n_preferred_ciphers; i++) {
3974 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3978 for (j = 0; j < c->nciphers; j++) {
3979 if (in_commasep_string(c->list[j]->name, str, len)) {
3980 s->sccipher_tobe = c->list[j];
3985 if (s->sccipher_tobe) {
3987 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3991 if (!s->sccipher_tobe) {
3992 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
3993 str ? str : "(null)"));
3997 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3998 for (i = 0; i < s->nmacs; i++) {
3999 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4000 s->csmac_tobe = s->maclist[i];
4004 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4005 for (i = 0; i < s->nmacs; i++) {
4006 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4007 s->scmac_tobe = s->maclist[i];
4011 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4012 for (i = 0; i < lenof(compressions) + 1; i++) {
4013 const struct ssh_compress *c =
4014 i == 0 ? s->preferred_comp : compressions[i - 1];
4015 if (in_commasep_string(c->name, str, len)) {
4020 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4021 for (i = 0; i < lenof(compressions) + 1; i++) {
4022 const struct ssh_compress *c =
4023 i == 0 ? s->preferred_comp : compressions[i - 1];
4024 if (in_commasep_string(c->name, str, len)) {
4032 * Work out the number of bits of key we will need from the key
4033 * exchange. We start with the maximum key length of either
4039 csbits = s->cscipher_tobe->keylen;
4040 scbits = s->sccipher_tobe->keylen;
4041 s->nbits = (csbits > scbits ? csbits : scbits);
4043 /* The keys only have 160-bit entropy, since they're based on
4044 * a SHA-1 hash. So cap the key size at 160 bits. */
4049 * If we're doing Diffie-Hellman group exchange, start by
4050 * requesting a group.
4052 if (ssh->kex == &ssh_diffiehellman_gex) {
4053 logevent("Doing Diffie-Hellman group exchange");
4054 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4056 * Work out how big a DH group we will need to allow that
4059 s->pbits = 512 << ((s->nbits - 1) / 64);
4060 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4061 ssh2_pkt_adduint32(ssh, s->pbits);
4065 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4066 bombout(("expected key exchange group packet from server"));
4069 s->p = ssh2_pkt_getmp(ssh);
4070 s->g = ssh2_pkt_getmp(ssh);
4071 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4072 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4073 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4075 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4076 ssh->kex_ctx = dh_setup_group1();
4077 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4078 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4081 logevent("Doing Diffie-Hellman key exchange");
4083 * Now generate and send e for Diffie-Hellman.
4085 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4086 ssh2_pkt_init(ssh, s->kex_init_value);
4087 ssh2_pkt_addmp(ssh, s->e);
4091 if (ssh->pktin.type != s->kex_reply_value) {
4092 bombout(("expected key exchange reply packet from server"));
4095 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4096 s->f = ssh2_pkt_getmp(ssh);
4097 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4099 s->K = dh_find_K(ssh->kex_ctx, s->f);
4101 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4102 if (ssh->kex == &ssh_diffiehellman_gex) {
4103 sha_uint32(&ssh->exhash, s->pbits);
4104 sha_mpint(&ssh->exhash, s->p);
4105 sha_mpint(&ssh->exhash, s->g);
4107 sha_mpint(&ssh->exhash, s->e);
4108 sha_mpint(&ssh->exhash, s->f);
4109 sha_mpint(&ssh->exhash, s->K);
4110 SHA_Final(&ssh->exhash, s->exchange_hash);
4112 dh_cleanup(ssh->kex_ctx);
4113 ssh->kex_ctx = NULL;
4116 debug(("Exchange hash is:\n"));
4117 dmemdump(s->exchange_hash, 20);
4120 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4122 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4123 (char *)s->exchange_hash, 20)) {
4124 bombout(("Server's host key did not match the signature supplied"));
4129 * Authenticate remote host: verify host key. (We've already
4130 * checked the signature of the exchange hash.)
4132 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4133 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4134 verify_ssh_host_key(ssh->frontend,
4135 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4136 s->keystr, s->fingerprint);
4137 if (s->first_kex) { /* don't bother logging this in rekeys */
4138 logevent("Host key fingerprint is:");
4139 logevent(s->fingerprint);
4141 sfree(s->fingerprint);
4143 ssh->hostkey->freekey(s->hkey);
4146 * Send SSH2_MSG_NEWKEYS.
4148 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4152 * Expect SSH2_MSG_NEWKEYS from server.
4155 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4156 bombout(("expected new-keys packet from server"));
4161 * Create and initialise session keys.
4163 if (ssh->cs_cipher_ctx)
4164 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4165 ssh->cscipher = s->cscipher_tobe;
4166 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4168 if (ssh->sc_cipher_ctx)
4169 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4170 ssh->sccipher = s->sccipher_tobe;
4171 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4173 if (ssh->cs_mac_ctx)
4174 ssh->csmac->free_context(ssh->cs_mac_ctx);
4175 ssh->csmac = s->csmac_tobe;
4176 ssh->cs_mac_ctx = ssh->csmac->make_context();
4178 if (ssh->sc_mac_ctx)
4179 ssh->scmac->free_context(ssh->sc_mac_ctx);
4180 ssh->scmac = s->scmac_tobe;
4181 ssh->sc_mac_ctx = ssh->scmac->make_context();
4183 if (ssh->cs_comp_ctx)
4184 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4185 ssh->cscomp = s->cscomp_tobe;
4186 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4188 if (ssh->sc_comp_ctx)
4189 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4190 ssh->sccomp = s->sccomp_tobe;
4191 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4194 * Set IVs after keys. Here we use the exchange hash from the
4195 * _first_ key exchange.
4198 unsigned char keyspace[40];
4200 memcpy(ssh->v2_session_id, s->exchange_hash,
4201 sizeof(s->exchange_hash));
4202 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4203 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4204 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4205 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4206 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4207 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4208 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4209 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4210 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4211 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4212 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4213 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4215 logeventf(ssh, "Initialised %.200s client->server encryption",
4216 ssh->cscipher->text_name);
4217 logeventf(ssh, "Initialised %.200s server->client encryption",
4218 ssh->sccipher->text_name);
4219 if (ssh->cscomp->text_name)
4220 logeventf(ssh, "Initialised %s compression",
4221 ssh->cscomp->text_name);
4222 if (ssh->sccomp->text_name)
4223 logeventf(ssh, "Initialised %s decompression",
4224 ssh->sccomp->text_name);
4227 * If this is the first key exchange phase, we must pass the
4228 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4229 * wants to see it but because it will need time to initialise
4230 * itself before it sees an actual packet. In subsequent key
4231 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4232 * it would only confuse the layer above.
4234 if (!s->first_kex) {
4240 * Now we're encrypting. Begin returning 1 to the protocol main
4241 * function so that other things can run on top of the
4242 * transport. If we ever see a KEXINIT, we must go back to the
4245 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4248 logevent("Server initiated key re-exchange");
4249 goto begin_key_exchange;
4255 * Add data to an SSH2 channel output buffer.
4257 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4260 bufchain_add(&c->v.v2.outbuffer, buf, len);
4264 * Attempt to send data on an SSH2 channel.
4266 static int ssh2_try_send(struct ssh_channel *c)
4270 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4273 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4274 if ((unsigned)len > c->v.v2.remwindow)
4275 len = c->v.v2.remwindow;
4276 if ((unsigned)len > c->v.v2.remmaxpkt)
4277 len = c->v.v2.remmaxpkt;
4278 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4279 ssh2_pkt_adduint32(ssh, c->remoteid);
4280 ssh2_pkt_addstring_start(ssh);
4281 ssh2_pkt_addstring_data(ssh, data, len);
4283 bufchain_consume(&c->v.v2.outbuffer, len);
4284 c->v.v2.remwindow -= len;
4288 * After having sent as much data as we can, return the amount
4291 return bufchain_size(&c->v.v2.outbuffer);
4295 * Potentially enlarge the window on an SSH2 channel.
4297 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4302 * Never send WINDOW_ADJUST for a channel that the remote side
4303 * already thinks it's closed; there's no point, since it won't
4304 * be sending any more data anyway.
4309 if (newwin > c->v.v2.locwindow) {
4310 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4311 ssh2_pkt_adduint32(ssh, c->remoteid);
4312 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4314 c->v.v2.locwindow = newwin;
4319 * Handle the SSH2 userauth and connection layers.
4321 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4323 struct do_ssh2_authconn_state {
4325 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4327 AUTH_KEYBOARD_INTERACTIVE
4331 AUTH_TYPE_PUBLICKEY,
4332 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4333 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4335 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4336 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4338 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4339 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4340 int kbd_inter_running;
4342 int num_prompts, curr_prompt, echo;
4347 void *publickey_blob;
4348 int publickey_bloblen;
4349 unsigned char request[5], *response, *p;
4353 char *pkblob, *alg, *commentp;
4354 int pklen, alglen, commentlen;
4355 int siglen, retlen, len;
4356 char *q, *agentreq, *ret;
4359 crState(do_ssh2_authconn_state);
4361 crBegin(ssh->do_ssh2_authconn_crstate);
4364 * Request userauth protocol, and await a response to it.
4366 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4367 ssh2_pkt_addstring(ssh, "ssh-userauth");
4369 crWaitUntilV(ispkt);
4370 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4371 bombout(("Server refused user authentication protocol"));
4376 * We repeat this whole loop, including the username prompt,
4377 * until we manage a successful authentication. If the user
4378 * types the wrong _password_, they can be sent back to the
4379 * beginning to try another username, if this is configured on.
4380 * (If they specify a username in the config, they are never
4381 * asked, even if they do give a wrong password.)
4383 * I think this best serves the needs of
4385 * - the people who have no configuration, no keys, and just
4386 * want to try repeated (username,password) pairs until they
4387 * type both correctly
4389 * - people who have keys and configuration but occasionally
4390 * need to fall back to passwords
4392 * - people with a key held in Pageant, who might not have
4393 * logged in to a particular machine before; so they want to
4394 * type a username, and then _either_ their key will be
4395 * accepted, _or_ they will type a password. If they mistype
4396 * the username they will want to be able to get back and
4399 s->username[0] = '\0';
4400 s->got_username = FALSE;
4405 if (s->got_username && !ssh->cfg.change_username) {
4407 * We got a username last time round this loop, and
4408 * with change_username turned off we don't try to get
4411 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4412 if (ssh_get_line && !ssh_getline_pw_only) {
4413 if (!ssh_get_line("login as: ",
4414 s->username, sizeof(s->username), FALSE)) {
4416 * get_line failed to get a username.
4419 logevent("No username provided. Abandoning session.");
4420 ssh_closing((Plug)ssh, NULL, 0, 0);
4424 int ret; /* need not be saved across crReturn */
4425 c_write_str(ssh, "login as: ");
4427 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4429 crWaitUntilV(!ispkt);
4430 ret = process_userpass_input(ssh, in, inlen);
4434 c_write_str(ssh, "\r\n");
4436 s->username[strcspn(s->username, "\n\r")] = '\0';
4439 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4440 s->username[sizeof(s->username)-1] = '\0';
4441 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4442 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4443 c_write_str(ssh, stuff);
4447 s->got_username = TRUE;
4450 * Send an authentication request using method "none": (a)
4451 * just in case it succeeds, and (b) so that we know what
4452 * authentication methods we can usefully try next.
4454 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4456 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4457 ssh2_pkt_addstring(ssh, s->username);
4458 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4459 ssh2_pkt_addstring(ssh, "none"); /* method */
4461 s->type = AUTH_TYPE_NONE;
4463 s->we_are_in = FALSE;
4465 s->tried_pubkey_config = FALSE;
4466 s->tried_agent = FALSE;
4467 s->tried_keyb_inter = FALSE;
4468 s->kbd_inter_running = FALSE;
4469 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4470 if (!filename_is_null(ssh->cfg.keyfile)) {
4472 logeventf(ssh, "Reading private key file \"%.150s\"",
4473 filename_to_str(&ssh->cfg.keyfile));
4474 keytype = key_type(&ssh->cfg.keyfile);
4475 if (keytype == SSH_KEYTYPE_SSH2) {
4477 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4478 &s->publickey_bloblen);
4481 logeventf(ssh, "Unable to use this key file (%s)",
4482 key_type_to_str(keytype));
4483 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4485 filename_to_str(&ssh->cfg.keyfile),
4486 key_type_to_str(keytype));
4487 c_write_str(ssh, msgbuf);
4489 s->publickey_blob = NULL;
4492 s->publickey_blob = NULL;
4496 * Wait for the result of the last authentication request.
4499 crWaitUntilV(ispkt);
4500 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4504 * Don't show the banner if we're operating in
4505 * non-verbose non-interactive mode. (It's probably
4506 * a script, which means nobody will read the
4507 * banner _anyway_, and moreover the printing of
4508 * the banner will screw up processing on the
4509 * output of (say) plink.)
4511 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4512 ssh2_pkt_getstring(ssh, &banner, &size);
4514 c_write_untrusted(ssh, banner, size);
4516 crWaitUntilV(ispkt);
4518 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4519 logevent("Access granted");
4520 s->we_are_in = TRUE;
4524 if (s->kbd_inter_running &&
4525 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4527 * This is either a further set-of-prompts packet
4528 * in keyboard-interactive authentication, or it's
4529 * the same one and we came back here with `gotit'
4530 * set. In the former case, we must reset the
4531 * curr_prompt variable.
4535 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4536 bombout(("Strange packet received during authentication: type %d",
4544 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4545 * we can look at the string in it and know what we can
4546 * helpfully try next.
4548 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4551 ssh2_pkt_getstring(ssh, &methods, &methlen);
4552 s->kbd_inter_running = FALSE;
4553 if (!ssh2_pkt_getbool(ssh)) {
4555 * We have received an unequivocal Access
4556 * Denied. This can translate to a variety of
4559 * - if we'd just tried "none" authentication,
4560 * it's not worth printing anything at all
4562 * - if we'd just tried a public key _offer_,
4563 * the message should be "Server refused our
4564 * key" (or no message at all if the key
4565 * came from Pageant)
4567 * - if we'd just tried anything else, the
4568 * message really should be "Access denied".
4570 * Additionally, if we'd just tried password
4571 * authentication, we should break out of this
4572 * whole loop so as to go back to the username
4575 if (s->type == AUTH_TYPE_NONE) {
4577 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4578 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4579 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4580 c_write_str(ssh, "Server refused our key\r\n");
4581 logevent("Server refused public key");
4582 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4583 /* server declined keyboard-interactive; ignore */
4585 c_write_str(ssh, "Access denied\r\n");
4586 logevent("Access denied");
4587 if (s->type == AUTH_TYPE_PASSWORD) {
4588 s->we_are_in = FALSE;
4593 c_write_str(ssh, "Further authentication required\r\n");
4594 logevent("Further authentication required");
4598 in_commasep_string("publickey", methods, methlen);
4600 in_commasep_string("password", methods, methlen);
4601 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4602 in_commasep_string("keyboard-interactive", methods, methlen);
4606 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4609 * Most password/passphrase prompts will be
4610 * non-echoing, so we set this to 0 by default.
4611 * Exception is that some keyboard-interactive prompts
4612 * can be echoing, in which case we'll set this to 1.
4616 if (!s->method && s->can_pubkey &&
4617 agent_exists() && !s->tried_agent) {
4619 * Attempt public-key authentication using Pageant.
4624 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4625 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4627 s->tried_agent = TRUE;
4629 logevent("Pageant is running. Requesting keys.");
4631 /* Request the keys held by the agent. */
4632 PUT_32BIT(s->request, 1);
4633 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4634 agent_query(s->request, 5, &r, &s->responselen);
4635 s->response = (unsigned char *) r;
4636 if (s->response && s->responselen >= 5 &&
4637 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4638 s->p = s->response + 5;
4639 s->nkeys = GET_32BIT(s->p);
4643 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4646 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4651 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4654 s->pklen = GET_32BIT(s->p);
4656 if (s->publickey_blob &&
4657 s->pklen == s->publickey_bloblen &&
4658 !memcmp(s->p, s->publickey_blob,
4659 s->publickey_bloblen)) {
4660 logevent("This key matches configured key file");
4661 s->tried_pubkey_config = 1;
4663 s->pkblob = (char *)s->p;
4665 s->alglen = GET_32BIT(s->pkblob);
4666 s->alg = s->pkblob + 4;
4667 s->commentlen = GET_32BIT(s->p);
4669 s->commentp = (char *)s->p;
4670 s->p += s->commentlen;
4671 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4672 ssh2_pkt_addstring(ssh, s->username);
4673 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4674 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4675 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4676 ssh2_pkt_addstring_start(ssh);
4677 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4678 ssh2_pkt_addstring_start(ssh);
4679 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4682 crWaitUntilV(ispkt);
4683 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4684 logevent("Key refused");
4688 if (flags & FLAG_VERBOSE) {
4689 c_write_str(ssh, "Authenticating with "
4691 c_write(ssh, s->commentp, s->commentlen);
4692 c_write_str(ssh, "\" from agent\r\n");
4696 * Server is willing to accept the key.
4697 * Construct a SIGN_REQUEST.
4699 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4700 ssh2_pkt_addstring(ssh, s->username);
4701 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4702 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4703 ssh2_pkt_addbool(ssh, TRUE);
4704 ssh2_pkt_addstring_start(ssh);
4705 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4706 ssh2_pkt_addstring_start(ssh);
4707 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4709 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4710 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4712 s->len = 1; /* message type */
4713 s->len += 4 + s->pklen; /* key blob */
4714 s->len += 4 + s->siglen; /* data to sign */
4715 s->len += 4; /* flags */
4716 s->agentreq = snewn(4 + s->len, char);
4717 PUT_32BIT(s->agentreq, s->len);
4718 s->q = s->agentreq + 4;
4719 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4720 PUT_32BIT(s->q, s->pklen);
4722 memcpy(s->q, s->pkblob, s->pklen);
4724 PUT_32BIT(s->q, s->siglen);
4726 /* Now the data to be signed... */
4727 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4728 PUT_32BIT(s->q, 20);
4731 memcpy(s->q, ssh->v2_session_id, 20);
4733 memcpy(s->q, ssh->pktout.data + 5,
4734 ssh->pktout.length - 5);
4735 s->q += ssh->pktout.length - 5;
4736 /* And finally the (zero) flags word. */
4738 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4742 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4743 logevent("Sending Pageant's response");
4744 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4746 GET_32BIT(s->ret + 5));
4752 ("Pageant failed to answer challenge");
4762 if (!s->method && s->can_pubkey && s->publickey_blob
4763 && !s->tried_pubkey_config) {
4764 unsigned char *pub_blob;
4765 char *algorithm, *comment;
4768 s->tried_pubkey_config = TRUE;
4770 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4771 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4774 * Try the public key supplied in the configuration.
4776 * First, offer the public blob to see if the server is
4777 * willing to accept it.
4780 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4784 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4785 ssh2_pkt_addstring(ssh, s->username);
4786 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4787 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4788 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4789 ssh2_pkt_addstring(ssh, algorithm);
4790 ssh2_pkt_addstring_start(ssh);
4791 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4794 logevent("Offered public key"); /* FIXME */
4796 crWaitUntilV(ispkt);
4797 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4799 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4800 continue; /* key refused; give up on it */
4803 logevent("Offer of public key accepted");
4805 * Actually attempt a serious authentication using
4808 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4809 sprintf(s->pwprompt,
4810 "Passphrase for key \"%.100s\": ",
4816 c_write_str(ssh, "Authenticating with public key \"");
4817 c_write_str(ssh, comment);
4818 c_write_str(ssh, "\"\r\n");
4819 s->method = AUTH_PUBLICKEY_FILE;
4823 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4824 s->method = AUTH_KEYBOARD_INTERACTIVE;
4825 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4826 s->tried_keyb_inter = TRUE;
4828 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4829 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4831 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4832 ssh2_pkt_addstring(ssh, s->username);
4833 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4834 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4835 ssh2_pkt_addstring(ssh, ""); /* lang */
4836 ssh2_pkt_addstring(ssh, "");
4839 crWaitUntilV(ispkt);
4840 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4841 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4843 logevent("Keyboard-interactive authentication refused");
4844 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4848 s->kbd_inter_running = TRUE;
4852 if (s->kbd_inter_running) {
4853 s->method = AUTH_KEYBOARD_INTERACTIVE;
4854 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4855 s->tried_keyb_inter = TRUE;
4857 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4858 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4860 if (s->curr_prompt == 0) {
4862 * We've got a fresh USERAUTH_INFO_REQUEST.
4863 * Display header data, and start going through
4866 char *name, *inst, *lang;
4867 int name_len, inst_len, lang_len;
4869 ssh2_pkt_getstring(ssh, &name, &name_len);
4870 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4871 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4873 c_write_untrusted(ssh, name, name_len);
4874 c_write_str(ssh, "\r\n");
4877 c_write_untrusted(ssh, inst, inst_len);
4878 c_write_str(ssh, "\r\n");
4880 s->num_prompts = ssh2_pkt_getuint32(ssh);
4884 * If there are prompts remaining in the packet,
4885 * display one and get a response.
4887 if (s->curr_prompt < s->num_prompts) {
4891 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4892 if (prompt_len > 0) {
4893 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4894 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4895 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4898 "<server failed to send prompt>: ");
4900 s->echo = ssh2_pkt_getbool(ssh);
4906 if (!s->method && s->can_passwd) {
4907 s->method = AUTH_PASSWORD;
4908 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4909 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4910 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4917 if (!ssh_get_line(s->pwprompt, s->password,
4918 sizeof(s->password), TRUE)) {
4920 * get_line failed to get a password (for
4921 * example because one was supplied on the
4922 * command line which has already failed to
4925 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4926 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4927 ssh2_pkt_addstring(ssh, "No more passwords available"
4929 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4931 logevent("Unable to authenticate");
4932 connection_fatal(ssh->frontend,
4933 "Unable to authenticate");
4934 ssh_closing((Plug)ssh, NULL, 0, 0);
4938 int ret; /* need not be saved across crReturn */
4939 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4942 setup_userpass_input(ssh, s->password,
4943 sizeof(s->password), s->echo);
4945 crWaitUntilV(!ispkt);
4946 ret = process_userpass_input(ssh, in, inlen);
4950 c_write_str(ssh, "\r\n");
4954 if (s->method == AUTH_PUBLICKEY_FILE) {
4956 * We have our passphrase. Now try the actual authentication.
4958 struct ssh2_userkey *key;
4960 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
4961 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4962 if (key == SSH2_WRONG_PASSPHRASE) {
4963 c_write_str(ssh, "Wrong passphrase\r\n");
4964 s->tried_pubkey_config = FALSE;
4966 c_write_str(ssh, "Unable to load private key\r\n");
4967 s->tried_pubkey_config = TRUE;
4969 /* Send a spurious AUTH_NONE to return to the top. */
4970 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4971 ssh2_pkt_addstring(ssh, s->username);
4972 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4973 ssh2_pkt_addstring(ssh, "none"); /* method */
4975 s->type = AUTH_TYPE_NONE;
4977 unsigned char *pkblob, *sigblob, *sigdata;
4978 int pkblob_len, sigblob_len, sigdata_len;
4982 * We have loaded the private key and the server
4983 * has announced that it's willing to accept it.
4984 * Hallelujah. Generate a signature and send it.
4986 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4987 ssh2_pkt_addstring(ssh, s->username);
4988 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4989 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4990 ssh2_pkt_addbool(ssh, TRUE);
4991 ssh2_pkt_addstring(ssh, key->alg->name);
4992 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4993 ssh2_pkt_addstring_start(ssh);
4994 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
4997 * The data to be signed is:
5001 * followed by everything so far placed in the
5004 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5005 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5007 sigdata = snewn(sigdata_len, unsigned char);
5009 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5010 PUT_32BIT(sigdata+p, 20);
5013 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5014 memcpy(sigdata+p, ssh->pktout.data + 5,
5015 ssh->pktout.length - 5);
5016 p += ssh->pktout.length - 5;
5017 assert(p == sigdata_len);
5018 sigblob = key->alg->sign(key->data, (char *)sigdata,
5019 sigdata_len, &sigblob_len);
5020 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5021 sigblob, sigblob_len);
5027 s->type = AUTH_TYPE_PUBLICKEY;
5029 } else if (s->method == AUTH_PASSWORD) {
5031 * We send the password packet lumped tightly together with
5032 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5033 * string long enough to make the total length of the two
5034 * packets constant. This should ensure that a passive
5035 * listener doing traffic analyis can't work out the length
5038 * For this to work, we need an assumption about the
5039 * maximum length of the password packet. I think 256 is
5040 * pretty conservative. Anyone using a password longer than
5041 * that probably doesn't have much to worry about from
5042 * people who find out how long their password is!
5044 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5045 ssh2_pkt_addstring(ssh, s->username);
5046 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5047 ssh2_pkt_addstring(ssh, "password");
5048 ssh2_pkt_addbool(ssh, FALSE);
5049 ssh2_pkt_addstring(ssh, s->password);
5050 memset(s->password, 0, sizeof(s->password));
5051 ssh2_pkt_defer(ssh);
5053 * We'll include a string that's an exact multiple of the
5054 * cipher block size. If the cipher is NULL for some
5055 * reason, we don't do this trick at all because we gain
5058 if (ssh->cscipher) {
5061 stringlen = (256 - ssh->deferred_len);
5062 stringlen += ssh->cscipher->blksize - 1;
5063 stringlen -= (stringlen % ssh->cscipher->blksize);
5066 * Temporarily disable actual compression,
5067 * so we can guarantee to get this string
5068 * exactly the length we want it. The
5069 * compression-disabling routine should
5070 * return an integer indicating how many
5071 * bytes we should adjust our string length
5075 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5077 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5078 ssh2_pkt_addstring_start(ssh);
5079 for (i = 0; i < stringlen; i++) {
5080 char c = (char) random_byte();
5081 ssh2_pkt_addstring_data(ssh, &c, 1);
5083 ssh2_pkt_defer(ssh);
5085 ssh_pkt_defersend(ssh);
5086 logevent("Sent password");
5087 s->type = AUTH_TYPE_PASSWORD;
5088 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5089 if (s->curr_prompt == 0) {
5090 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5091 ssh2_pkt_adduint32(ssh, s->num_prompts);
5093 if (s->need_pw) { /* only add pw if we just got one! */
5094 ssh2_pkt_addstring(ssh, s->password);
5095 memset(s->password, 0, sizeof(s->password));
5098 if (s->curr_prompt >= s->num_prompts) {
5102 * If there are prompts remaining, we set
5103 * `gotit' so that we won't attempt to get
5104 * another packet. Then we go back round the
5105 * loop and will end up retrieving another
5106 * prompt out of the existing packet. Funky or
5111 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5113 c_write_str(ssh, "No supported authentication methods"
5114 " left to try!\r\n");
5115 logevent("No supported authentications offered."
5117 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5118 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5119 ssh2_pkt_addstring(ssh, "No supported authentication"
5120 " methods available");
5121 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5123 ssh_closing((Plug)ssh, NULL, 0, 0);
5127 } while (!s->we_are_in);
5130 * Now we're authenticated for the connection protocol. The
5131 * connection protocol will automatically have started at this
5132 * point; there's no need to send SERVICE_REQUEST.
5136 * So now create a channel with a session in it.
5138 ssh->channels = newtree234(ssh_channelcmp);
5139 ssh->mainchan = snew(struct ssh_channel);
5140 ssh->mainchan->ssh = ssh;
5141 ssh->mainchan->localid = alloc_channel_id(ssh);
5142 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5143 ssh2_pkt_addstring(ssh, "session");
5144 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5145 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5146 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5147 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5149 crWaitUntilV(ispkt);
5150 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5151 bombout(("Server refused to open a session"));
5153 /* FIXME: error data comes back in FAILURE packet */
5155 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5156 bombout(("Server's channel confirmation cited wrong channel"));
5159 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5160 ssh->mainchan->type = CHAN_MAINSESSION;
5161 ssh->mainchan->closes = 0;
5162 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5163 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5164 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5165 add234(ssh->channels, ssh->mainchan);
5166 logevent("Opened channel for session");
5169 * Potentially enable X11 forwarding.
5171 if (ssh->cfg.x11_forward) {
5172 char proto[20], data[64];
5173 logevent("Requesting X11 forwarding");
5174 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5175 data, sizeof(data), ssh->cfg.x11_auth);
5176 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5177 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5178 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5179 ssh2_pkt_addstring(ssh, "x11-req");
5180 ssh2_pkt_addbool(ssh, 1); /* want reply */
5181 ssh2_pkt_addbool(ssh, 0); /* many connections */
5182 ssh2_pkt_addstring(ssh, proto);
5183 ssh2_pkt_addstring(ssh, data);
5184 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5188 crWaitUntilV(ispkt);
5189 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5190 unsigned i = ssh2_pkt_getuint32(ssh);
5191 struct ssh_channel *c;
5192 c = find234(ssh->channels, &i, ssh_channelfind);
5194 continue; /* nonexistent channel */
5195 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5197 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5199 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5200 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5201 bombout(("Unexpected response to X11 forwarding request:"
5202 " packet type %d", ssh->pktin.type));
5205 logevent("X11 forwarding refused");
5207 logevent("X11 forwarding enabled");
5208 ssh->X11_fwd_enabled = TRUE;
5213 * Enable port forwardings.
5218 int sport,dport,sserv,dserv;
5219 char sports[256], dports[256], saddr[256], host[256];
5221 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5222 /* Add port forwardings. */
5223 ssh->portfwd_strptr = ssh->cfg.portfwd;
5224 while (*ssh->portfwd_strptr) {
5225 type = *ssh->portfwd_strptr++;
5228 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5229 if (*ssh->portfwd_strptr == ':') {
5231 * We've seen a colon in the middle of the
5232 * source port number. This means that
5233 * everything we've seen until now is the
5234 * source _address_, so we'll move it into
5235 * saddr and start sports from the beginning
5238 ssh->portfwd_strptr++;
5240 strcpy(saddr, sports);
5243 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5247 if (*ssh->portfwd_strptr == '\t')
5248 ssh->portfwd_strptr++;
5250 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5251 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5254 if (*ssh->portfwd_strptr == ':')
5255 ssh->portfwd_strptr++;
5257 while (*ssh->portfwd_strptr) {
5258 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5261 ssh->portfwd_strptr++;
5262 dport = atoi(dports);
5266 dport = net_service_lookup(dports);
5268 logeventf(ssh, "Service lookup failed for destination"
5269 " port \"%s\"", dports);
5273 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5275 sport = atoi(sports);
5279 sport = net_service_lookup(sports);
5281 logeventf(ssh, "Service lookup failed for source"
5282 " port \"%s\"", sports);
5285 if (sport && dport) {
5287 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5288 sport, ssh, &ssh->cfg);
5289 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5290 " forwarding to %s:%.*s%.*s%d%.*s",
5291 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5292 (int)(*saddr?1:0), ":",
5293 (int)(sserv ? strlen(sports) : 0), sports,
5294 sserv, "(", sport, sserv, ")",
5296 (int)(dserv ? strlen(dports) : 0), dports,
5297 dserv, "(", dport, dserv, ")");
5298 } else if (type == 'D') {
5299 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5300 sport, ssh, &ssh->cfg);
5301 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5302 " doing SOCKS dynamic forwarding",
5303 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5304 (int)(*saddr?1:0), ":",
5305 (int)(sserv ? strlen(sports) : 0), sports,
5306 sserv, "(", sport, sserv, ")");
5308 struct ssh_rportfwd *pf;
5309 pf = snew(struct ssh_rportfwd);
5310 strcpy(pf->dhost, host);
5313 if (add234(ssh->rportfwds, pf) != pf) {
5314 logeventf(ssh, "Duplicate remote port forwarding"
5315 " to %s:%d", host, dport);
5318 logeventf(ssh, "Requesting remote port "
5319 "%.*s%.*s%.*s%.*s%d%.*s"
5320 " forward to %s:%.*s%.*s%d%.*s",
5321 (int)(*saddr?strlen(saddr):0),
5323 (int)(*saddr?1:0), ":",
5324 (int)(sserv ? strlen(sports) : 0), sports,
5325 sserv, "(", sport, sserv, ")",
5327 (int)(dserv ? strlen(dports) : 0), dports,
5328 dserv, "(", dport, dserv, ")");
5329 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5330 ssh2_pkt_addstring(ssh, "tcpip-forward");
5331 ssh2_pkt_addbool(ssh, 1);/* want reply */
5333 ssh2_pkt_addstring(ssh, saddr);
5334 if (ssh->cfg.rport_acceptall)
5335 ssh2_pkt_addstring(ssh, "0.0.0.0");
5337 ssh2_pkt_addstring(ssh, "127.0.0.1");
5338 ssh2_pkt_adduint32(ssh, sport);
5342 crWaitUntilV(ispkt);
5343 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5344 unsigned i = ssh2_pkt_getuint32(ssh);
5345 struct ssh_channel *c;
5346 c = find234(ssh->channels, &i, ssh_channelfind);
5348 continue;/* nonexistent channel */
5349 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5351 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5353 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5354 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5355 bombout(("Unexpected response to port "
5356 "forwarding request: packet type %d",
5360 logevent("Server refused this port forwarding");
5362 logevent("Remote port forwarding enabled");
5371 * Potentially enable agent forwarding.
5373 if (ssh->cfg.agentfwd && agent_exists()) {
5374 logevent("Requesting OpenSSH-style agent forwarding");
5375 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5376 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5377 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5378 ssh2_pkt_addbool(ssh, 1); /* want reply */
5382 crWaitUntilV(ispkt);
5383 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5384 unsigned i = ssh2_pkt_getuint32(ssh);
5385 struct ssh_channel *c;
5386 c = find234(ssh->channels, &i, ssh_channelfind);
5388 continue; /* nonexistent channel */
5389 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5391 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5393 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5394 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5395 bombout(("Unexpected response to agent forwarding request:"
5396 " packet type %d", ssh->pktin.type));
5399 logevent("Agent forwarding refused");
5401 logevent("Agent forwarding enabled");
5402 ssh->agentfwd_enabled = TRUE;
5407 * Now allocate a pty for the session.
5409 if (!ssh->cfg.nopty) {
5410 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5411 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5412 ssh2_pkt_addstring(ssh, "pty-req");
5413 ssh2_pkt_addbool(ssh, 1); /* want reply */
5414 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5415 ssh2_pkt_adduint32(ssh, ssh->term_width);
5416 ssh2_pkt_adduint32(ssh, ssh->term_height);
5417 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5418 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5419 ssh2_pkt_addstring_start(ssh);
5420 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5422 ssh->state = SSH_STATE_INTERMED;
5425 crWaitUntilV(ispkt);
5426 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5427 unsigned i = ssh2_pkt_getuint32(ssh);
5428 struct ssh_channel *c;
5429 c = find234(ssh->channels, &i, ssh_channelfind);
5431 continue; /* nonexistent channel */
5432 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5434 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5436 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5437 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5438 bombout(("Unexpected response to pty request:"
5439 " packet type %d", ssh->pktin.type));
5442 c_write_str(ssh, "Server refused to allocate pty\r\n");
5443 ssh->editing = ssh->echoing = 1;
5445 logevent("Allocated pty");
5448 ssh->editing = ssh->echoing = 1;
5452 * Start a shell or a remote command. We may have to attempt
5453 * this twice if the config data has provided a second choice
5460 if (ssh->fallback_cmd) {
5461 subsys = ssh->cfg.ssh_subsys2;
5462 cmd = ssh->cfg.remote_cmd_ptr2;
5464 subsys = ssh->cfg.ssh_subsys;
5465 cmd = ssh->cfg.remote_cmd_ptr;
5468 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5469 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5471 ssh2_pkt_addstring(ssh, "subsystem");
5472 ssh2_pkt_addbool(ssh, 1); /* want reply */
5473 ssh2_pkt_addstring(ssh, cmd);
5475 ssh2_pkt_addstring(ssh, "exec");
5476 ssh2_pkt_addbool(ssh, 1); /* want reply */
5477 ssh2_pkt_addstring(ssh, cmd);
5479 ssh2_pkt_addstring(ssh, "shell");
5480 ssh2_pkt_addbool(ssh, 1); /* want reply */
5484 crWaitUntilV(ispkt);
5485 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5486 unsigned i = ssh2_pkt_getuint32(ssh);
5487 struct ssh_channel *c;
5488 c = find234(ssh->channels, &i, ssh_channelfind);
5490 continue; /* nonexistent channel */
5491 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5493 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5494 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5495 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5496 bombout(("Unexpected response to shell/command request:"
5497 " packet type %d", ssh->pktin.type));
5501 * We failed to start the command. If this is the
5502 * fallback command, we really are finished; if it's
5503 * not, and if the fallback command exists, try falling
5504 * back to it before complaining.
5506 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5507 logevent("Primary command failed; attempting fallback");
5508 ssh->fallback_cmd = TRUE;
5511 bombout(("Server refused to start a shell/command"));
5514 logevent("Started a shell/command");
5519 ssh->state = SSH_STATE_SESSION;
5520 if (ssh->size_needed)
5521 ssh_size(ssh, ssh->term_width, ssh->term_height);
5522 if (ssh->eof_needed)
5523 ssh_special(ssh, TS_EOF);
5529 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5533 s->try_send = FALSE;
5535 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5536 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5539 unsigned i = ssh2_pkt_getuint32(ssh);
5540 struct ssh_channel *c;
5541 c = find234(ssh->channels, &i, ssh_channelfind);
5543 continue; /* nonexistent channel */
5544 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5545 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5546 continue; /* extended but not stderr */
5547 ssh2_pkt_getstring(ssh, &data, &length);
5550 c->v.v2.locwindow -= length;
5552 case CHAN_MAINSESSION:
5554 from_backend(ssh->frontend, ssh->pktin.type ==
5555 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5559 bufsize = x11_send(c->u.x11.s, data, length);
5562 bufsize = pfd_send(c->u.pfd.s, data, length);
5565 while (length > 0) {
5566 if (c->u.a.lensofar < 4) {
5567 int l = min(4 - c->u.a.lensofar, length);
5568 memcpy(c->u.a.msglen + c->u.a.lensofar,
5572 c->u.a.lensofar += l;
5574 if (c->u.a.lensofar == 4) {
5576 4 + GET_32BIT(c->u.a.msglen);
5577 c->u.a.message = snewn(c->u.a.totallen,
5579 memcpy(c->u.a.message, c->u.a.msglen, 4);
5581 if (c->u.a.lensofar >= 4 && length > 0) {
5583 min(c->u.a.totallen - c->u.a.lensofar,
5585 memcpy(c->u.a.message + c->u.a.lensofar,
5589 c->u.a.lensofar += l;
5591 if (c->u.a.lensofar == c->u.a.totallen) {
5592 void *reply, *sentreply;
5594 agent_query(c->u.a.message,
5595 c->u.a.totallen, &reply,
5600 /* Fake SSH_AGENT_FAILURE. */
5601 sentreply = "\0\0\0\1\5";
5604 ssh2_add_channel_data(c, sentreply, replylen);
5608 sfree(c->u.a.message);
5609 c->u.a.lensofar = 0;
5616 * If we are not buffering too much data,
5617 * enlarge the window again at the remote side.
5619 if (bufsize < OUR_V2_WINSIZE)
5620 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5622 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5623 unsigned i = ssh2_pkt_getuint32(ssh);
5624 struct ssh_channel *c;
5626 c = find234(ssh->channels, &i, ssh_channelfind);
5628 continue; /* nonexistent channel */
5630 if (c->type == CHAN_X11) {
5632 * Remote EOF on an X11 channel means we should
5633 * wrap up and close the channel ourselves.
5635 x11_close(c->u.x11.s);
5637 } else if (c->type == CHAN_AGENT) {
5639 } else if (c->type == CHAN_SOCKDATA) {
5640 pfd_close(c->u.pfd.s);
5643 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5644 unsigned i = ssh2_pkt_getuint32(ssh);
5645 struct ssh_channel *c;
5647 c = find234(ssh->channels, &i, ssh_channelfind);
5648 if (!c || ((int)c->remoteid) == -1) {
5649 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5650 c ? "half-open" : "nonexistent", i));
5652 /* Do pre-close processing on the channel. */
5654 case CHAN_MAINSESSION:
5655 break; /* nothing to see here, move along */
5657 if (c->u.x11.s != NULL)
5658 x11_close(c->u.x11.s);
5665 if (c->u.pfd.s != NULL)
5666 pfd_close(c->u.pfd.s);
5670 if (c->closes == 0) {
5671 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5672 ssh2_pkt_adduint32(ssh, c->remoteid);
5675 del234(ssh->channels, c);
5676 bufchain_clear(&c->v.v2.outbuffer);
5680 * See if that was the last channel left open.
5682 if (count234(ssh->channels) == 0) {
5683 logevent("All channels closed. Disconnecting");
5686 * We used to send SSH_MSG_DISCONNECT here,
5687 * because I'd believed that _every_ conforming
5688 * SSH2 connection had to end with a disconnect
5689 * being sent by at least one side; apparently
5690 * I was wrong and it's perfectly OK to
5691 * unceremoniously slam the connection shut
5692 * when you're done, and indeed OpenSSH feels
5693 * this is more polite than sending a
5694 * DISCONNECT. So now we don't.
5696 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5697 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5698 ssh2_pkt_addstring(ssh, "All open channels closed");
5699 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5702 ssh_closing((Plug)ssh, NULL, 0, 0);
5705 continue; /* remote sends close; ignore (FIXME) */
5706 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5707 unsigned i = ssh2_pkt_getuint32(ssh);
5708 struct ssh_channel *c;
5709 c = find234(ssh->channels, &i, ssh_channelfind);
5710 if (!c || c->closes)
5711 continue; /* nonexistent or closing channel */
5712 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5714 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
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 (c->type != CHAN_SOCKDATA_DORMANT)
5721 continue; /* dunno why they're confirming this */
5722 c->remoteid = ssh2_pkt_getuint32(ssh);
5723 c->type = CHAN_SOCKDATA;
5724 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5725 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5727 pfd_confirm(c->u.pfd.s);
5730 * We have a pending close on this channel,
5731 * which we decided on before the server acked
5732 * the channel open. So now we know the
5733 * remoteid, we can close it again.
5735 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5736 ssh2_pkt_adduint32(ssh, c->remoteid);
5739 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5740 unsigned i = ssh2_pkt_getuint32(ssh);
5741 struct ssh_channel *c;
5742 c = find234(ssh->channels, &i, ssh_channelfind);
5744 continue; /* nonexistent channel */
5745 if (c->type != CHAN_SOCKDATA_DORMANT)
5746 continue; /* dunno why they're failing this */
5748 logevent("Forwarded connection refused by server");
5750 pfd_close(c->u.pfd.s);
5752 del234(ssh->channels, c);
5754 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5757 int typelen, want_reply;
5758 struct ssh_channel *c;
5760 localid = ssh2_pkt_getuint32(ssh);
5761 ssh2_pkt_getstring(ssh, &type, &typelen);
5762 want_reply = ssh2_pkt_getbool(ssh);
5765 * First, check that the channel exists. Otherwise,
5766 * we can instantly disconnect with a rude message.
5768 c = find234(ssh->channels, &localid, ssh_channelfind);
5771 sprintf(buf, "Received channel request for nonexistent"
5772 " channel %d", localid);
5774 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5775 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5776 ssh2_pkt_addstring(ssh, buf);
5777 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5779 connection_fatal(ssh->frontend, "%s", buf);
5780 ssh_closing((Plug)ssh, NULL, 0, 0);
5785 * Having got the channel number, we now look at
5786 * the request type string to see if it's something
5789 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5790 c == ssh->mainchan) {
5791 /* We recognise "exit-status" on the primary channel. */
5793 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5794 sprintf(buf, "Server sent command exit status %d",
5798 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5799 ssh2_pkt_adduint32(ssh, c->remoteid);
5804 * This is a channel request we don't know
5805 * about, so we now either ignore the request
5806 * or respond with CHANNEL_FAILURE, depending
5810 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5811 ssh2_pkt_adduint32(ssh, c->remoteid);
5815 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5817 int typelen, want_reply;
5819 ssh2_pkt_getstring(ssh, &type, &typelen);
5820 want_reply = ssh2_pkt_getbool(ssh);
5823 * We currently don't support any global requests
5824 * at all, so we either ignore the request or
5825 * respond with REQUEST_FAILURE, depending on
5829 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5832 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5839 struct ssh_channel *c;
5840 unsigned remid, winsize, pktsize;
5841 ssh2_pkt_getstring(ssh, &type, &typelen);
5842 c = snew(struct ssh_channel);
5845 remid = ssh2_pkt_getuint32(ssh);
5846 winsize = ssh2_pkt_getuint32(ssh);
5847 pktsize = ssh2_pkt_getuint32(ssh);
5849 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5850 char *addrstr = snewn(peeraddrlen+1, char);
5851 memcpy(addrstr, peeraddr, peeraddrlen);
5852 peeraddr[peeraddrlen] = '\0';
5853 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5854 peerport = ssh2_pkt_getuint32(ssh);
5856 if (!ssh->X11_fwd_enabled)
5857 error = "X11 forwarding is not enabled";
5858 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5859 ssh->x11auth, addrstr, peerport,
5860 &ssh->cfg) != NULL) {
5861 error = "Unable to open an X11 connection";
5867 } else if (typelen == 15 &&
5868 !memcmp(type, "forwarded-tcpip", 15)) {
5869 struct ssh_rportfwd pf, *realpf;
5872 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5873 pf.sport = ssh2_pkt_getuint32(ssh);
5874 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5875 peerport = ssh2_pkt_getuint32(ssh);
5876 realpf = find234(ssh->rportfwds, &pf, NULL);
5877 if (realpf == NULL) {
5878 error = "Remote port is not recognised";
5880 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5881 realpf->dport, c, &ssh->cfg);
5882 logeventf(ssh, "Received remote port open request"
5883 " for %s:%d", realpf->dhost, realpf->dport);
5885 logeventf(ssh, "Port open failed: %s", e);
5886 error = "Port open failed";
5888 logevent("Forwarded port opened successfully");
5889 c->type = CHAN_SOCKDATA;
5892 } else if (typelen == 22 &&
5893 !memcmp(type, "auth-agent@openssh.com", 3)) {
5894 if (!ssh->agentfwd_enabled)
5895 error = "Agent forwarding is not enabled";
5897 c->type = CHAN_AGENT; /* identify channel type */
5898 c->u.a.lensofar = 0;
5901 error = "Unsupported channel type requested";
5904 c->remoteid = remid;
5906 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5907 ssh2_pkt_adduint32(ssh, c->remoteid);
5908 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5909 ssh2_pkt_addstring(ssh, error);
5910 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5914 c->localid = alloc_channel_id(ssh);
5916 c->v.v2.locwindow = OUR_V2_WINSIZE;
5917 c->v.v2.remwindow = winsize;
5918 c->v.v2.remmaxpkt = pktsize;
5919 bufchain_init(&c->v.v2.outbuffer);
5920 add234(ssh->channels, c);
5921 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5922 ssh2_pkt_adduint32(ssh, c->remoteid);
5923 ssh2_pkt_adduint32(ssh, c->localid);
5924 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5925 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5929 bombout(("Strange packet received: type %d", ssh->pktin.type));
5934 * We have spare data. Add it to the channel buffer.
5936 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5941 struct ssh_channel *c;
5943 * Try to send data on all channels if we can.
5945 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5948 continue; /* don't send on closing channels */
5949 bufsize = ssh2_try_send(c);
5952 case CHAN_MAINSESSION:
5953 /* stdin need not receive an unthrottle
5954 * notification since it will be polled */
5957 x11_unthrottle(c->u.x11.s);
5960 /* agent sockets are request/response and need no
5961 * buffer management */
5964 pfd_unthrottle(c->u.pfd.s);
5976 * Handle the top-level SSH2 protocol.
5978 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5980 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5982 do_ssh2_authconn(ssh, in, inlen, ispkt);
5986 * Called to set up the connection.
5988 * Returns an error message, or NULL on success.
5990 static char *ssh_init(void *frontend_handle, void **backend_handle,
5992 char *host, int port, char **realhost, int nodelay)
5997 ssh = snew(struct ssh_tag);
5998 ssh->cfg = *cfg; /* STRUCTURE COPY */
5999 ssh->version = 0; /* when not ready yet */
6002 ssh->v1_cipher_ctx = NULL;
6003 ssh->crcda_ctx = NULL;
6004 ssh->cscipher = NULL;
6005 ssh->cs_cipher_ctx = NULL;
6006 ssh->sccipher = NULL;
6007 ssh->sc_cipher_ctx = NULL;
6009 ssh->cs_mac_ctx = NULL;
6011 ssh->sc_mac_ctx = NULL;
6013 ssh->cs_comp_ctx = NULL;
6015 ssh->sc_comp_ctx = NULL;
6017 ssh->kex_ctx = NULL;
6018 ssh->hostkey = NULL;
6020 ssh->state = SSH_STATE_PREPACKET;
6021 ssh->size_needed = FALSE;
6022 ssh->eof_needed = FALSE;
6026 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6027 ssh->pktin = ssh->pktout = empty;
6029 ssh->deferred_send_data = NULL;
6030 ssh->deferred_len = 0;
6031 ssh->deferred_size = 0;
6032 ssh->fallback_cmd = 0;
6034 ssh->x11auth = NULL;
6035 ssh->v1_compressing = FALSE;
6036 ssh->v2_outgoing_sequence = 0;
6037 ssh->ssh1_rdpkt_crstate = 0;
6038 ssh->ssh2_rdpkt_crstate = 0;
6039 ssh->do_ssh_init_crstate = 0;
6040 ssh->ssh_gotdata_crstate = 0;
6041 ssh->ssh1_protocol_crstate = 0;
6042 ssh->do_ssh1_login_crstate = 0;
6043 ssh->do_ssh2_transport_crstate = 0;
6044 ssh->do_ssh2_authconn_crstate = 0;
6045 ssh->do_ssh_init_state = NULL;
6046 ssh->do_ssh1_login_state = NULL;
6047 ssh->do_ssh2_transport_state = NULL;
6048 ssh->do_ssh2_authconn_state = NULL;
6049 ssh->mainchan = NULL;
6050 ssh->throttled_all = 0;
6051 ssh->v1_stdout_throttling = 0;
6053 *backend_handle = ssh;
6056 if (crypto_startup() == 0)
6057 return "Microsoft high encryption pack not installed!";
6060 ssh->frontend = frontend_handle;
6061 ssh->term_width = ssh->cfg.width;
6062 ssh->term_height = ssh->cfg.height;
6064 ssh->channels = NULL;
6065 ssh->rportfwds = NULL;
6070 ssh->v1_throttle_count = 0;
6071 ssh->overall_bufsize = 0;
6072 ssh->fallback_cmd = 0;
6074 ssh->protocol = NULL;
6076 p = connect_to_host(ssh, host, port, realhost, nodelay);
6083 static void ssh_free(void *handle)
6085 Ssh ssh = (Ssh) handle;
6086 struct ssh_channel *c;
6087 struct ssh_rportfwd *pf;
6089 if (ssh->v1_cipher_ctx)
6090 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6091 if (ssh->cs_cipher_ctx)
6092 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6093 if (ssh->sc_cipher_ctx)
6094 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6095 if (ssh->cs_mac_ctx)
6096 ssh->csmac->free_context(ssh->cs_mac_ctx);
6097 if (ssh->sc_mac_ctx)
6098 ssh->scmac->free_context(ssh->sc_mac_ctx);
6099 if (ssh->cs_comp_ctx)
6100 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6101 if (ssh->sc_comp_ctx)
6102 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6104 dh_cleanup(ssh->kex_ctx);
6105 sfree(ssh->savedhost);
6107 if (ssh->channels) {
6108 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6111 if (c->u.x11.s != NULL)
6112 x11_close(c->u.x11.s);
6115 if (c->u.pfd.s != NULL)
6116 pfd_close(c->u.pfd.s);
6121 freetree234(ssh->channels);
6124 if (ssh->rportfwds) {
6125 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6127 freetree234(ssh->rportfwds);
6129 sfree(ssh->deferred_send_data);
6131 x11_free_auth(ssh->x11auth);
6132 sfree(ssh->do_ssh_init_state);
6133 sfree(ssh->do_ssh1_login_state);
6134 sfree(ssh->do_ssh2_transport_state);
6135 sfree(ssh->do_ssh2_authconn_state);
6143 * Reconfigure the SSH backend.
6145 * Currently, this function does nothing very useful. In future,
6146 * however, we could do some handy things with it. For example, we
6147 * could make the port forwarding configurer active in the Change
6148 * Settings box, and this routine could close down existing
6149 * forwardings and open up new ones in response to changes.
6151 static void ssh_reconfig(void *handle, Config *cfg)
6153 Ssh ssh = (Ssh) handle;
6154 ssh->cfg = *cfg; /* STRUCTURE COPY */
6158 * Called to send data down the Telnet connection.
6160 static int ssh_send(void *handle, char *buf, int len)
6162 Ssh ssh = (Ssh) handle;
6164 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6167 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6169 return ssh_sendbuffer(ssh);
6173 * Called to query the current amount of buffered stdin data.
6175 static int ssh_sendbuffer(void *handle)
6177 Ssh ssh = (Ssh) handle;
6180 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6184 * If the SSH socket itself has backed up, add the total backup
6185 * size on that to any individual buffer on the stdin channel.
6188 if (ssh->throttled_all)
6189 override_value = ssh->overall_bufsize;
6191 if (ssh->version == 1) {
6192 return override_value;
6193 } else if (ssh->version == 2) {
6194 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6195 return override_value;
6197 return (override_value +
6198 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6205 * Called to set the size of the window from SSH's POV.
6207 static void ssh_size(void *handle, int width, int height)
6209 Ssh ssh = (Ssh) handle;
6211 ssh->term_width = width;
6212 ssh->term_height = height;
6214 switch (ssh->state) {
6215 case SSH_STATE_BEFORE_SIZE:
6216 case SSH_STATE_PREPACKET:
6217 case SSH_STATE_CLOSED:
6218 break; /* do nothing */
6219 case SSH_STATE_INTERMED:
6220 ssh->size_needed = TRUE; /* buffer for later */
6222 case SSH_STATE_SESSION:
6223 if (!ssh->cfg.nopty) {
6224 if (ssh->version == 1) {
6225 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6226 PKT_INT, ssh->term_height,
6227 PKT_INT, ssh->term_width,
6228 PKT_INT, 0, PKT_INT, 0, PKT_END);
6230 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6231 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6232 ssh2_pkt_addstring(ssh, "window-change");
6233 ssh2_pkt_addbool(ssh, 0);
6234 ssh2_pkt_adduint32(ssh, ssh->term_width);
6235 ssh2_pkt_adduint32(ssh, ssh->term_height);
6236 ssh2_pkt_adduint32(ssh, 0);
6237 ssh2_pkt_adduint32(ssh, 0);
6246 * Return a list of the special codes that make sense in this
6249 static const struct telnet_special *ssh_get_specials(void *handle)
6251 Ssh ssh = (Ssh) handle;
6253 if (ssh->version == 1) {
6254 static const struct telnet_special ssh1_specials[] = {
6255 {"IGNORE message", TS_NOP},
6258 return ssh1_specials;
6259 } else if (ssh->version == 2) {
6260 static const struct telnet_special ssh2_specials[] = {
6262 {"IGNORE message", TS_NOP},
6265 return ssh2_specials;
6271 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6272 * can send an EOF and collect resulting output (e.g. `plink
6275 static void ssh_special(void *handle, Telnet_Special code)
6277 Ssh ssh = (Ssh) handle;
6279 if (code == TS_EOF) {
6280 if (ssh->state != SSH_STATE_SESSION) {
6282 * Buffer the EOF in case we are pre-SESSION, so we can
6283 * send it as soon as we reach SESSION.
6286 ssh->eof_needed = TRUE;
6289 if (ssh->version == 1) {
6290 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6292 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6293 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6296 logevent("Sent EOF message");
6297 } else if (code == TS_PING || code == TS_NOP) {
6298 if (ssh->state == SSH_STATE_CLOSED
6299 || ssh->state == SSH_STATE_PREPACKET) return;
6300 if (ssh->version == 1) {
6301 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6302 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6304 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6305 ssh2_pkt_addstring_start(ssh);
6308 } else if (code == TS_BRK) {
6309 if (ssh->state == SSH_STATE_CLOSED
6310 || ssh->state == SSH_STATE_PREPACKET) return;
6311 if (ssh->version == 1) {
6312 logevent("Unable to send BREAK signal in SSH1");
6314 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6315 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6316 ssh2_pkt_addstring(ssh, "break");
6317 ssh2_pkt_addbool(ssh, 0);
6318 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6326 void *new_sock_channel(void *handle, Socket s)
6328 Ssh ssh = (Ssh) handle;
6329 struct ssh_channel *c;
6330 c = snew(struct ssh_channel);
6334 c->remoteid = -1; /* to be set when open confirmed */
6335 c->localid = alloc_channel_id(ssh);
6337 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6339 bufchain_init(&c->v.v2.outbuffer);
6340 add234(ssh->channels, c);
6346 * This is called when stdout/stderr (the entity to which
6347 * from_backend sends data) manages to clear some backlog.
6349 static void ssh_unthrottle(void *handle, int bufsize)
6351 Ssh ssh = (Ssh) handle;
6352 if (ssh->version == 1) {
6353 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6354 ssh->v1_stdout_throttling = 0;
6355 ssh1_throttle(ssh, -1);
6358 if (ssh->mainchan && ssh->mainchan->closes == 0)
6359 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6363 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6365 struct ssh_channel *c = (struct ssh_channel *)channel;
6368 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6370 if (ssh->version == 1) {
6371 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6372 PKT_INT, c->localid,
6375 //PKT_STR, <org:orgport>,
6378 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6379 ssh2_pkt_addstring(ssh, "direct-tcpip");
6380 ssh2_pkt_adduint32(ssh, c->localid);
6381 c->v.v2.locwindow = OUR_V2_WINSIZE;
6382 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6383 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6384 ssh2_pkt_addstring(ssh, hostname);
6385 ssh2_pkt_adduint32(ssh, port);
6387 * We make up values for the originator data; partly it's
6388 * too much hassle to keep track, and partly I'm not
6389 * convinced the server should be told details like that
6390 * about my local network configuration.
6392 ssh2_pkt_addstring(ssh, "client-side-connection");
6393 ssh2_pkt_adduint32(ssh, 0);
6399 static Socket ssh_socket(void *handle)
6401 Ssh ssh = (Ssh) handle;
6405 static int ssh_sendok(void *handle)
6407 Ssh ssh = (Ssh) handle;
6408 return ssh->send_ok;
6411 static int ssh_ldisc(void *handle, int option)
6413 Ssh ssh = (Ssh) handle;
6414 if (option == LD_ECHO)
6415 return ssh->echoing;
6416 if (option == LD_EDIT)
6417 return ssh->editing;
6421 static void ssh_provide_ldisc(void *handle, void *ldisc)
6423 Ssh ssh = (Ssh) handle;
6427 static void ssh_provide_logctx(void *handle, void *logctx)
6429 Ssh ssh = (Ssh) handle;
6430 ssh->logctx = logctx;
6433 static int ssh_return_exitcode(void *handle)
6435 Ssh ssh = (Ssh) handle;
6439 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6443 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6444 * that fails. This variable is the means by which scp.c can reach
6445 * into the SSH code and find out which one it got.
6447 extern int ssh_fallback_cmd(void *handle)
6449 Ssh ssh = (Ssh) handle;
6450 return ssh->fallback_cmd;
6453 Backend ssh_backend = {
6463 ssh_return_exitcode,