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Tidy up Simon's FontSpec abstraction.
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 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 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
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 */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 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 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
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
113
32874aea 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 */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
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",
147};
9005f3ba 148
32874aea 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 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
8e975795 165#define BUG_SSH2_DH_GEX 64
bd358db1 166
00db133f 167#define translate(x) if (type == x) return #x
51470298 168#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 169static char *ssh1_pkt_type(int type)
00db133f 170{
171 translate(SSH1_MSG_DISCONNECT);
172 translate(SSH1_SMSG_PUBLIC_KEY);
173 translate(SSH1_CMSG_SESSION_KEY);
174 translate(SSH1_CMSG_USER);
175 translate(SSH1_CMSG_AUTH_RSA);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
178 translate(SSH1_CMSG_AUTH_PASSWORD);
179 translate(SSH1_CMSG_REQUEST_PTY);
180 translate(SSH1_CMSG_WINDOW_SIZE);
181 translate(SSH1_CMSG_EXEC_SHELL);
182 translate(SSH1_CMSG_EXEC_CMD);
183 translate(SSH1_SMSG_SUCCESS);
184 translate(SSH1_SMSG_FAILURE);
185 translate(SSH1_CMSG_STDIN_DATA);
186 translate(SSH1_SMSG_STDOUT_DATA);
187 translate(SSH1_SMSG_STDERR_DATA);
188 translate(SSH1_CMSG_EOF);
189 translate(SSH1_SMSG_EXIT_STATUS);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
192 translate(SSH1_MSG_CHANNEL_DATA);
193 translate(SSH1_MSG_CHANNEL_CLOSE);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
195 translate(SSH1_SMSG_X11_OPEN);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
197 translate(SSH1_MSG_PORT_OPEN);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
199 translate(SSH1_SMSG_AGENT_OPEN);
200 translate(SSH1_MSG_IGNORE);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
204 translate(SSH1_MSG_DEBUG);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION);
206 translate(SSH1_CMSG_AUTH_TIS);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
209 translate(SSH1_CMSG_AUTH_CCARD);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
212 return "unknown";
213}
ae9ae89f 214static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 215{
216 translate(SSH2_MSG_DISCONNECT);
217 translate(SSH2_MSG_IGNORE);
218 translate(SSH2_MSG_UNIMPLEMENTED);
219 translate(SSH2_MSG_DEBUG);
220 translate(SSH2_MSG_SERVICE_REQUEST);
221 translate(SSH2_MSG_SERVICE_ACCEPT);
222 translate(SSH2_MSG_KEXINIT);
223 translate(SSH2_MSG_NEWKEYS);
224 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
225 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
230 translate(SSH2_MSG_USERAUTH_REQUEST);
231 translate(SSH2_MSG_USERAUTH_FAILURE);
232 translate(SSH2_MSG_USERAUTH_SUCCESS);
233 translate(SSH2_MSG_USERAUTH_BANNER);
234 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
238 translate(SSH2_MSG_GLOBAL_REQUEST);
239 translate(SSH2_MSG_REQUEST_SUCCESS);
240 translate(SSH2_MSG_REQUEST_FAILURE);
241 translate(SSH2_MSG_CHANNEL_OPEN);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
245 translate(SSH2_MSG_CHANNEL_DATA);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
247 translate(SSH2_MSG_CHANNEL_EOF);
248 translate(SSH2_MSG_CHANNEL_CLOSE);
249 translate(SSH2_MSG_CHANNEL_REQUEST);
250 translate(SSH2_MSG_CHANNEL_SUCCESS);
251 translate(SSH2_MSG_CHANNEL_FAILURE);
252 return "unknown";
253}
254#undef translate
255#undef translatec
7d503c31 256
fb09bf1c 257#define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
262
263#define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
268
7cca0d81 269enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 270
374330e2 271/* Coroutine mechanics for the sillier bits of the code */
51470298 272#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
273#define crState(t) \
274 struct t *s; \
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
276 s = ssh->t;
277#define crFinish(z) } *crLine = 0; return (z); }
278#define crFinishV } *crLine = 0; return; }
374330e2 279#define crReturn(z) \
280 do {\
51470298 281 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 282 } while (0)
283#define crReturnV \
284 do {\
51470298 285 *crLine=__LINE__; return; case __LINE__:;\
374330e2 286 } while (0)
51470298 287#define crStop(z) do{ *crLine = 0; return (z); }while(0)
288#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 289#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 290#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 291
51470298 292typedef struct ssh_tag *Ssh;
293
51470298 294static void ssh2_pkt_init(Ssh, int pkt_type);
295static void ssh2_pkt_addbool(Ssh, unsigned char value);
296static void ssh2_pkt_adduint32(Ssh, unsigned long value);
297static void ssh2_pkt_addstring_start(Ssh);
298static void ssh2_pkt_addstring_str(Ssh, char *data);
299static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
300static void ssh2_pkt_addstring(Ssh, char *data);
d8baa528 301static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 302static void ssh2_pkt_addmp(Ssh, Bignum b);
303static int ssh2_pkt_construct(Ssh);
304static void ssh2_pkt_send(Ssh);
3d63ca2e 305
5471d09a 306/*
307 * Buffer management constants. There are several of these for
308 * various different purposes:
309 *
310 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
311 * on a local data stream before we throttle the whole SSH
312 * connection (in SSH1 only). Throttling the whole connection is
313 * pretty drastic so we set this high in the hope it won't
314 * happen very often.
315 *
316 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
317 * on the SSH connection itself before we defensively throttle
318 * _all_ local data streams. This is pretty drastic too (though
319 * thankfully unlikely in SSH2 since the window mechanism should
320 * ensure that the server never has any need to throttle its end
321 * of the connection), so we set this high as well.
322 *
323 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
324 * channels.
325 */
326
327#define SSH1_BUFFER_LIMIT 32768
328#define SSH_MAX_BACKLOG 32768
329#define OUR_V2_WINSIZE 16384
d74d141c 330
a92dd380 331const static struct ssh_kex *kex_algs[] = {
a92dd380 332 &ssh_diffiehellman_gex,
32874aea 333 &ssh_diffiehellman
334};
e5574168 335
85cc02bb 336const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 337
e0e1a00d 338static void *nullmac_make_context(void)
339{
340 return NULL;
341}
342static void nullmac_free_context(void *handle)
343{
344}
345static void nullmac_key(void *handle, unsigned char *key)
32874aea 346{
347}
e0e1a00d 348static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 349 unsigned long seq)
350{
351}
e0e1a00d 352static int nullmac_verify(void *handle, unsigned char *blk, int len,
353 unsigned long seq)
32874aea 354{
355 return 1;
356}
57476f6b 357const static struct ssh_mac ssh_mac_none = {
e0e1a00d 358 nullmac_make_context, nullmac_free_context, nullmac_key,
359 nullmac_generate, nullmac_verify, "none", 0
e5574168 360};
8b2715b2 361const static struct ssh_mac *macs[] = {
32874aea 362 &ssh_sha1, &ssh_md5, &ssh_mac_none
363};
8b2715b2 364const static struct ssh_mac *buggymacs[] = {
32874aea 365 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
366};
e5574168 367
5366aed8 368static void *ssh_comp_none_init(void)
369{
370 return NULL;
371}
372static void ssh_comp_none_cleanup(void *handle)
32874aea 373{
374}
5366aed8 375static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 376 unsigned char **outblock, int *outlen)
377{
378 return 0;
379}
5366aed8 380static int ssh_comp_none_disable(void *handle)
32874aea 381{
4ba9b64b 382 return 0;
383}
57476f6b 384const static struct ssh_compress ssh_comp_none = {
4ba9b64b 385 "none",
5366aed8 386 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
387 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
388 ssh_comp_none_disable, NULL
e5574168 389};
4ba9b64b 390extern const struct ssh_compress ssh_zlib;
391const static struct ssh_compress *compressions[] = {
32874aea 392 &ssh_zlib, &ssh_comp_none
393};
374330e2 394
32874aea 395enum { /* channel types */
783415f8 396 CHAN_MAINSESSION,
397 CHAN_X11,
398 CHAN_AGENT,
bc240b21 399 CHAN_SOCKDATA,
400 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 401};
402
dacbd0e8 403/*
404 * 2-3-4 tree storing channels.
405 */
406struct ssh_channel {
51470298 407 Ssh ssh; /* pointer back to main context */
d211621f 408 unsigned remoteid, localid;
dacbd0e8 409 int type;
0357890f 410 /*
411 * In SSH1, this value contains four bits:
412 *
413 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
414 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
415 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
416 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
417 *
418 * A channel is completely finished with when all four bits are set.
419 */
dacbd0e8 420 int closes;
5471d09a 421 union {
422 struct ssh1_data_channel {
423 int throttling;
424 } v1;
425 struct ssh2_data_channel {
426 bufchain outbuffer;
427 unsigned remwindow, remmaxpkt;
428 unsigned locwindow;
429 } v2;
430 } v;
dacbd0e8 431 union {
32874aea 432 struct ssh_agent_channel {
433 unsigned char *message;
434 unsigned char msglen[4];
435 int lensofar, totallen;
436 } a;
437 struct ssh_x11_channel {
438 Socket s;
439 } x11;
d74d141c 440 struct ssh_pfd_channel {
441 Socket s;
442 } pfd;
dacbd0e8 443 } u;
444};
57476f6b 445
d74d141c 446/*
bc240b21 447 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
448 * 2 use this structure in different ways, reflecting SSH 2's
449 * altogether saner approach to port forwarding.
450 *
451 * In SSH 1, you arrange a remote forwarding by sending the server
452 * the remote port number, and the local destination host:port.
453 * When a connection comes in, the server sends you back that
454 * host:port pair, and you connect to it. This is a ready-made
455 * security hole if you're not on the ball: a malicious server
456 * could send you back _any_ host:port pair, so if you trustingly
457 * connect to the address it gives you then you've just opened the
458 * entire inside of your corporate network just by connecting
459 * through it to a dodgy SSH server. Hence, we must store a list of
460 * host:port pairs we _are_ trying to forward to, and reject a
461 * connection request from the server if it's not in the list.
462 *
463 * In SSH 2, each side of the connection minds its own business and
464 * doesn't send unnecessary information to the other. You arrange a
465 * remote forwarding by sending the server just the remote port
466 * number. When a connection comes in, the server tells you which
467 * of its ports was connected to; and _you_ have to remember what
468 * local host:port pair went with that port number.
469 *
470 * Hence: in SSH 1 this structure stores host:port pairs we intend
471 * to allow connections to, and is indexed by those host:port
472 * pairs. In SSH 2 it stores a mapping from source port to
473 * destination host:port pair, and is indexed by source port.
d74d141c 474 */
475struct ssh_rportfwd {
bc240b21 476 unsigned sport, dport;
477 char dhost[256];
d74d141c 478};
479
57476f6b 480struct Packet {
481 long length;
482 int type;
483 unsigned char *data;
484 unsigned char *body;
485 long savedpos;
486 long maxlen;
487};
488
51470298 489static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
490static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
491static void ssh_size(void *handle, int width, int height);
492static void ssh_special(void *handle, Telnet_Special);
5471d09a 493static int ssh2_try_send(struct ssh_channel *c);
51470298 494static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
495static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 496static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 497static int ssh_sendbuffer(void *handle);
57476f6b 498
51470298 499struct rdpkt1_state_tag {
57476f6b 500 long len, pad, biglen, to_read;
501 unsigned long realcrc, gotcrc;
502 unsigned char *p;
503 int i;
504 int chunk;
51470298 505};
57476f6b 506
51470298 507struct rdpkt2_state_tag {
960e736a 508 long len, pad, payload, packetlen, maclen;
509 int i;
510 int cipherblk;
511 unsigned long incoming_sequence;
51470298 512};
513
514struct ssh_tag {
515 const struct plug_function_table *fn;
516 /* the above field _must_ be first in the structure */
517
518 SHA_State exhash, exhashbase;
519
520 Socket s;
521
b9d7bcad 522 void *ldisc;
a8327734 523 void *logctx;
b9d7bcad 524
51470298 525 unsigned char session_key[32];
526 int v1_compressing;
527 int v1_remote_protoflags;
528 int v1_local_protoflags;
529 int agentfwd_enabled;
530 int X11_fwd_enabled;
531 int remote_bugs;
532 const struct ssh_cipher *cipher;
371e569c 533 void *v1_cipher_ctx;
0183b242 534 void *crcda_ctx;
51470298 535 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 536 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 537 const struct ssh_mac *csmac, *scmac;
e0e1a00d 538 void *cs_mac_ctx, *sc_mac_ctx;
51470298 539 const struct ssh_compress *cscomp, *sccomp;
5366aed8 540 void *cs_comp_ctx, *sc_comp_ctx;
51470298 541 const struct ssh_kex *kex;
542 const struct ssh_signkey *hostkey;
543 unsigned char v2_session_id[20];
27cd7fc2 544 void *kex_ctx;
51470298 545
546 char *savedhost;
547 int savedport;
548 int send_ok;
549 int echoing, editing;
550
551 void *frontend;
552
553 int term_width, term_height;
554
555 tree234 *channels; /* indexed by local id */
556 struct ssh_channel *mainchan; /* primary session channel */
557 int exitcode;
558
559 tree234 *rportfwds;
560
561 enum {
562 SSH_STATE_PREPACKET,
563 SSH_STATE_BEFORE_SIZE,
564 SSH_STATE_INTERMED,
565 SSH_STATE_SESSION,
566 SSH_STATE_CLOSED
567 } state;
568
569 int size_needed, eof_needed;
570
571 struct Packet pktin;
572 struct Packet pktout;
573 unsigned char *deferred_send_data;
574 int deferred_len, deferred_size;
575
576 /*
577 * Gross hack: pscp will try to start SFTP but fall back to
578 * scp1 if that fails. This variable is the means by which
579 * scp.c can reach into the SSH code and find out which one it
580 * got.
581 */
582 int fallback_cmd;
583
584 /*
585 * Used for username and password input.
586 */
587 char *userpass_input_buffer;
588 int userpass_input_buflen;
589 int userpass_input_bufpos;
590 int userpass_input_echo;
591
592 char *portfwd_strptr;
593 int pkt_ctx;
594
302121de 595 void *x11auth;
596
51470298 597 int version;
598 int v1_throttle_count;
599 int overall_bufsize;
600 int throttled_all;
601 int v1_stdout_throttling;
602 int v2_outgoing_sequence;
603
604 int ssh1_rdpkt_crstate;
605 int ssh2_rdpkt_crstate;
606 int do_ssh_init_crstate;
607 int ssh_gotdata_crstate;
608 int ssh1_protocol_crstate;
609 int do_ssh1_login_crstate;
610 int do_ssh2_transport_crstate;
611 int do_ssh2_authconn_crstate;
612
613 void *do_ssh_init_state;
614 void *do_ssh1_login_state;
615 void *do_ssh2_transport_state;
616 void *do_ssh2_authconn_state;
617
618 struct rdpkt1_state_tag rdpkt1_state;
619 struct rdpkt2_state_tag rdpkt2_state;
620
621 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
622 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 623
624 /*
625 * We maintain a full _copy_ of a Config structure here, not
626 * merely a pointer to it. That way, when we're passed a new
627 * one for reconfiguration, we can check the differences and
628 * potentially reconfigure port forwardings etc in mid-session.
629 */
630 Config cfg;
51470298 631};
960e736a 632
382908ad 633#define logevent(s) logevent(ssh->frontend, s)
a8327734 634
635/* logevent, only printf-formatted. */
ae9ae89f 636static void logeventf(Ssh ssh, char *fmt, ...)
a8327734 637{
638 va_list ap;
57356d63 639 char *buf;
a8327734 640
641 va_start(ap, fmt);
57356d63 642 buf = dupvprintf(fmt, ap);
a8327734 643 va_end(ap);
57356d63 644 logevent(buf);
57356d63 645 sfree(buf);
a8327734 646}
647
648#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
649 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
650 logeventf msg, connection_fatal msg )
651
32874aea 652static int ssh_channelcmp(void *av, void *bv)
653{
654 struct ssh_channel *a = (struct ssh_channel *) av;
655 struct ssh_channel *b = (struct ssh_channel *) bv;
656 if (a->localid < b->localid)
657 return -1;
658 if (a->localid > b->localid)
659 return +1;
dacbd0e8 660 return 0;
661}
32874aea 662static int ssh_channelfind(void *av, void *bv)
663{
664 unsigned *a = (unsigned *) av;
665 struct ssh_channel *b = (struct ssh_channel *) bv;
666 if (*a < b->localid)
667 return -1;
668 if (*a > b->localid)
669 return +1;
dacbd0e8 670 return 0;
671}
672
bc240b21 673static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 674{
675 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
676 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
677 int i;
bc240b21 678 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 679 return i < 0 ? -1 : +1;
bc240b21 680 if (a->dport > b->dport)
681 return +1;
682 if (a->dport < b->dport)
683 return -1;
684 return 0;
685}
686
687static int ssh_rportcmp_ssh2(void *av, void *bv)
688{
689 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
690 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 691
bc240b21 692 if (a->sport > b->sport)
d74d141c 693 return +1;
bc240b21 694 if (a->sport < b->sport)
695 return -1;
d74d141c 696 return 0;
697}
698
51470298 699static int alloc_channel_id(Ssh ssh)
32874aea 700{
260f3dec 701 const unsigned CHANNEL_NUMBER_OFFSET = 256;
702 unsigned low, high, mid;
d2371c81 703 int tsize;
704 struct ssh_channel *c;
705
706 /*
707 * First-fit allocation of channel numbers: always pick the
708 * lowest unused one. To do this, binary-search using the
709 * counted B-tree to find the largest channel ID which is in a
710 * contiguous sequence from the beginning. (Precisely
711 * everything in that sequence must have ID equal to its tree
712 * index plus CHANNEL_NUMBER_OFFSET.)
713 */
51470298 714 tsize = count234(ssh->channels);
d2371c81 715
32874aea 716 low = -1;
717 high = tsize;
d2371c81 718 while (high - low > 1) {
719 mid = (high + low) / 2;
51470298 720 c = index234(ssh->channels, mid);
d2371c81 721 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
722 low = mid; /* this one is fine */
723 else
724 high = mid; /* this one is past it */
725 }
726 /*
727 * Now low points to either -1, or the tree index of the
728 * largest ID in the initial sequence.
729 */
730 {
731 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 732 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 733 }
734 return low + 1 + CHANNEL_NUMBER_OFFSET;
735}
736
51470298 737static void c_write(Ssh ssh, char *buf, int len)
32874aea 738{
67779be7 739 if ((flags & FLAG_STDERR)) {
32874aea 740 int i;
741 for (i = 0; i < len; i++)
742 if (buf[i] != '\r')
743 fputc(buf[i], stderr);
fb09bf1c 744 return;
745 }
51470298 746 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 747}
748
51470298 749static void c_write_untrusted(Ssh ssh, char *buf, int len)
32874aea 750{
a209e957 751 int i;
752 for (i = 0; i < len; i++) {
32874aea 753 if (buf[i] == '\n')
51470298 754 c_write(ssh, "\r\n", 2);
32874aea 755 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 756 c_write(ssh, buf + i, 1);
a209e957 757 }
758}
759
51470298 760static void c_write_str(Ssh ssh, char *buf)
32874aea 761{
51470298 762 c_write(ssh, buf, strlen(buf));
1408a877 763}
764
fb09bf1c 765/*
766 * Collect incoming data in the incoming packet buffer.
e5574168 767 * Decipher and verify the packet when it is completely read.
768 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 769 * Update the *data and *datalen variables.
770 * Return the additional nr of bytes needed, or 0 when
771 * a complete packet is available.
772 */
51470298 773static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 774{
51470298 775 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 776
51470298 777 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 778
32874aea 779 next_packet:
37508af4 780
51470298 781 ssh->pktin.type = 0;
782 ssh->pktin.length = 0;
374330e2 783
57476f6b 784 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 785 while ((*datalen) == 0)
32874aea 786 crReturn(4 - st->i);
57476f6b 787 st->len = (st->len << 8) + **data;
fb09bf1c 788 (*data)++, (*datalen)--;
789 }
374330e2 790
57476f6b 791 st->pad = 8 - (st->len % 8);
792 st->biglen = st->len + st->pad;
51470298 793 ssh->pktin.length = st->len - 5;
fb09bf1c 794
51470298 795 if (ssh->pktin.maxlen < st->biglen) {
796 ssh->pktin.maxlen = st->biglen;
797 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
fb09bf1c 798 }
374330e2 799
57476f6b 800 st->to_read = st->biglen;
51470298 801 st->p = ssh->pktin.data;
57476f6b 802 while (st->to_read > 0) {
32874aea 803 st->chunk = st->to_read;
fb09bf1c 804 while ((*datalen) == 0)
57476f6b 805 crReturn(st->to_read);
806 if (st->chunk > (*datalen))
807 st->chunk = (*datalen);
808 memcpy(st->p, *data, st->chunk);
809 *data += st->chunk;
810 *datalen -= st->chunk;
811 st->p += st->chunk;
812 st->to_read -= st->chunk;
fb09bf1c 813 }
374330e2 814
0183b242 815 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
816 st->biglen, NULL)) {
a8327734 817 bombout((ssh,"Network attack (CRC compensation) detected!"));
9a3a93a5 818 crReturn(0);
819 }
820
51470298 821 if (ssh->cipher)
371e569c 822 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 823
51470298 824 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
825 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 826 if (st->gotcrc != st->realcrc) {
2dadaea5 827 bombout((ssh,"Incorrect CRC received on packet"));
32874aea 828 crReturn(0);
fb09bf1c 829 }
572f871e 830
51470298 831 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 832
51470298 833 if (ssh->v1_compressing) {
4ba9b64b 834 unsigned char *decompblk;
835 int decomplen;
5366aed8 836 zlib_decompress_block(ssh->sc_comp_ctx,
837 ssh->pktin.body - 1, ssh->pktin.length + 1,
4ba9b64b 838 &decompblk, &decomplen);
839
51470298 840 if (ssh->pktin.maxlen < st->pad + decomplen) {
841 ssh->pktin.maxlen = st->pad + decomplen;
842 ssh->pktin.data = srealloc(ssh->pktin.data,
843 ssh->pktin.maxlen + APIEXTRA);
844 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 845 }
846
51470298 847 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 848 sfree(decompblk);
51470298 849 ssh->pktin.length = decomplen - 1;
4ba9b64b 850 }
851
51470298 852 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 853
a8327734 854 if (ssh->logctx)
855 log_packet(ssh->logctx,
856 PKT_INCOMING, ssh->pktin.type,
857 ssh1_pkt_type(ssh->pktin.type),
858 ssh->pktin.body, ssh->pktin.length);
00db133f 859
51470298 860 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
861 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
862 ssh->pktin.type == SSH1_MSG_DEBUG ||
863 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
864 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
865 long stringlen = GET_32BIT(ssh->pktin.body);
866 if (stringlen + 4 != ssh->pktin.length) {
a8327734 867 bombout((ssh,"Received data packet with bogus string length"));
32874aea 868 crReturn(0);
869 }
fb09bf1c 870 }
871
51470298 872 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 873 /* log debug message */
eb4504cc 874 char buf[512];
51470298 875 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 876 strcpy(buf, "Remote debug message: ");
877 if (stringlen > 480)
878 stringlen = 480;
51470298 879 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 880 buf[8 + stringlen] = '\0';
fb09bf1c 881 logevent(buf);
882 goto next_packet;
51470298 883 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 884 /* do nothing */
885 goto next_packet;
886 }
887
51470298 888 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 889 /* log reason code in disconnect message */
890 char buf[256];
51470298 891 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 892 unsigned nowlen;
38c4a8da 893 strcpy(buf, "Remote sent disconnect: ");
894 nowlen = strlen(buf);
32874aea 895 if (msglen > sizeof(buf) - nowlen - 1)
896 msglen = sizeof(buf) - nowlen - 1;
51470298 897 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 898 buf[nowlen + msglen] = '\0';
247308b5 899 /* logevent(buf); (this is now done within the bombout macro) */
a8327734 900 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 901 crReturn(0);
38c4a8da 902 }
903
fb09bf1c 904 crFinish(0);
905}
906
51470298 907static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 908{
51470298 909 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 910
51470298 911 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 912
32874aea 913 next_packet:
51470298 914 ssh->pktin.type = 0;
915 ssh->pktin.length = 0;
916 if (ssh->sccipher)
917 st->cipherblk = ssh->sccipher->blksize;
e5574168 918 else
32874aea 919 st->cipherblk = 8;
960e736a 920 if (st->cipherblk < 8)
32874aea 921 st->cipherblk = 8;
960e736a 922
51470298 923 if (ssh->pktin.maxlen < st->cipherblk) {
924 ssh->pktin.maxlen = st->cipherblk;
925 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
e5574168 926 }
927
928 /*
929 * Acquire and decrypt the first block of the packet. This will
930 * contain the length and padding details.
931 */
32874aea 932 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 933 while ((*datalen) == 0)
32874aea 934 crReturn(st->cipherblk - st->i);
51470298 935 ssh->pktin.data[st->i] = *(*data)++;
32874aea 936 (*datalen)--;
e5574168 937 }
4252c9cc 938
51470298 939 if (ssh->sccipher)
371e569c 940 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
941 ssh->pktin.data, st->cipherblk);
e5574168 942
943 /*
944 * Now get the length and padding figures.
945 */
51470298 946 st->len = GET_32BIT(ssh->pktin.data);
947 st->pad = ssh->pktin.data[4];
e5574168 948
949 /*
717dc483 950 * _Completely_ silly lengths should be stomped on before they
951 * do us any more damage.
952 */
953 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
a8327734 954 bombout((ssh,"Incoming packet was garbled on decryption"));
717dc483 955 crReturn(0);
956 }
957
958 /*
e5574168 959 * This enables us to deduce the payload length.
960 */
960e736a 961 st->payload = st->len - st->pad - 1;
e5574168 962
51470298 963 ssh->pktin.length = st->payload + 5;
e5574168 964
965 /*
966 * So now we can work out the total packet length.
967 */
960e736a 968 st->packetlen = st->len + 4;
51470298 969 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 970
971 /*
972 * Adjust memory allocation if packet is too big.
973 */
51470298 974 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
975 ssh->pktin.maxlen = st->packetlen + st->maclen;
976 ssh->pktin.data = srealloc(ssh->pktin.data,
977 ssh->pktin.maxlen + APIEXTRA);
e5574168 978 }
979
980 /*
981 * Read and decrypt the remainder of the packet.
982 */
32874aea 983 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
984 st->i++) {
e5574168 985 while ((*datalen) == 0)
960e736a 986 crReturn(st->packetlen + st->maclen - st->i);
51470298 987 ssh->pktin.data[st->i] = *(*data)++;
32874aea 988 (*datalen)--;
e5574168 989 }
990 /* Decrypt everything _except_ the MAC. */
51470298 991 if (ssh->sccipher)
371e569c 992 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
993 ssh->pktin.data + st->cipherblk,
51470298 994 st->packetlen - st->cipherblk);
e5574168 995
996 /*
997 * Check the MAC.
998 */
51470298 999 if (ssh->scmac
e0e1a00d 1000 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1001 st->incoming_sequence)) {
a8327734 1002 bombout((ssh,"Incorrect MAC received on packet"));
32874aea 1003 crReturn(0);
8d5de777 1004 }
32874aea 1005 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1006
4ba9b64b 1007 /*
1008 * Decompress packet payload.
1009 */
1010 {
1011 unsigned char *newpayload;
1012 int newlen;
51470298 1013 if (ssh->sccomp &&
5366aed8 1014 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1015 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1016 &newpayload, &newlen)) {
1017 if (ssh->pktin.maxlen < newlen + 5) {
1018 ssh->pktin.maxlen = newlen + 5;
1019 ssh->pktin.data = srealloc(ssh->pktin.data,
1020 ssh->pktin.maxlen + APIEXTRA);
4ba9b64b 1021 }
51470298 1022 ssh->pktin.length = 5 + newlen;
1023 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1024 sfree(newpayload);
4ba9b64b 1025 }
1026 }
1027
51470298 1028 ssh->pktin.savedpos = 6;
1029 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1030
a8327734 1031 if (ssh->logctx)
1032 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1033 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1034 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1035
51470298 1036 switch (ssh->pktin.type) {
3d63ca2e 1037 /*
1038 * These packets we must handle instantly.
1039 */
1040 case SSH2_MSG_DISCONNECT:
1041 {
1042 /* log reason code in disconnect message */
57356d63 1043 char *buf;
1044 int nowlen;
51470298 1045 int reason = GET_32BIT(ssh->pktin.data + 6);
1046 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
57356d63 1047
3d63ca2e 1048 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
57356d63 1049 buf = dupprintf("Received disconnect message (%s)",
1050 ssh2_disconnect_reasons[reason]);
3d63ca2e 1051 } else {
57356d63 1052 buf = dupprintf("Received disconnect message (unknown"
1053 " type %d)", reason);
3d63ca2e 1054 }
1055 logevent(buf);
57356d63 1056 sfree(buf);
1057 buf = dupprintf("Disconnection message text: %n%.*s",
33b82b22 1058 &nowlen, msglen, ssh->pktin.data + 14);
3d63ca2e 1059 logevent(buf);
a8327734 1060 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1061 reason,
1062 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1063 ssh2_disconnect_reasons[reason] : "unknown",
1064 buf+nowlen));
57356d63 1065 sfree(buf);
3d63ca2e 1066 crReturn(0);
1067 }
1068 break;
1069 case SSH2_MSG_IGNORE:
1070 goto next_packet;
1071 case SSH2_MSG_DEBUG:
1072 {
1073 /* log the debug message */
1074 char buf[512];
51470298 1075 /* int display = ssh->pktin.body[6]; */
1076 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1077 int prefix;
1078 strcpy(buf, "Remote debug message: ");
1079 prefix = strlen(buf);
51470298 1080 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1081 stringlen = sizeof(buf)-prefix-1;
51470298 1082 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1083 buf[prefix + stringlen] = '\0';
1084 logevent(buf);
38c4a8da 1085 }
3d63ca2e 1086 goto next_packet; /* FIXME: print the debug message */
1087
1088 /*
1089 * These packets we need do nothing about here.
1090 */
1091 case SSH2_MSG_UNIMPLEMENTED:
1092 case SSH2_MSG_SERVICE_REQUEST:
1093 case SSH2_MSG_SERVICE_ACCEPT:
1094 case SSH2_MSG_KEXINIT:
1095 case SSH2_MSG_NEWKEYS:
1096 case SSH2_MSG_KEXDH_INIT:
1097 case SSH2_MSG_KEXDH_REPLY:
1098 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1099 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1100 case SSH2_MSG_KEX_DH_GEX_INIT:
1101 case SSH2_MSG_KEX_DH_GEX_REPLY:
1102 case SSH2_MSG_USERAUTH_REQUEST:
1103 case SSH2_MSG_USERAUTH_FAILURE:
1104 case SSH2_MSG_USERAUTH_SUCCESS:
1105 case SSH2_MSG_USERAUTH_BANNER:
1106 case SSH2_MSG_USERAUTH_PK_OK:
1107 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1108 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1109 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1110 case SSH2_MSG_GLOBAL_REQUEST:
1111 case SSH2_MSG_REQUEST_SUCCESS:
1112 case SSH2_MSG_REQUEST_FAILURE:
1113 case SSH2_MSG_CHANNEL_OPEN:
1114 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1115 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1116 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1117 case SSH2_MSG_CHANNEL_DATA:
1118 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1119 case SSH2_MSG_CHANNEL_EOF:
1120 case SSH2_MSG_CHANNEL_CLOSE:
1121 case SSH2_MSG_CHANNEL_REQUEST:
1122 case SSH2_MSG_CHANNEL_SUCCESS:
1123 case SSH2_MSG_CHANNEL_FAILURE:
1124 break;
1125
1126 /*
1127 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1128 */
1129 default:
51470298 1130 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1131 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1132 ssh2_pkt_send(ssh);
3d63ca2e 1133 break;
38c4a8da 1134 }
1135
e5574168 1136 crFinish(0);
1137}
1138
51470298 1139static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1140{
374330e2 1141 int pad, biglen;
1142
1143 len += 5; /* type and CRC */
32874aea 1144 pad = 8 - (len % 8);
374330e2 1145 biglen = len + pad;
1146
51470298 1147 ssh->pktout.length = len - 5;
1148 if (ssh->pktout.maxlen < biglen) {
1149 ssh->pktout.maxlen = biglen;
8f203108 1150#ifdef MSCRYPTOAPI
fb09bf1c 1151 /* Allocate enough buffer space for extra block
8f203108 1152 * for MS CryptEncrypt() */
51470298 1153 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
8f203108 1154#else
51470298 1155 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
8f203108 1156#endif
374330e2 1157 }
51470298 1158 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1159}
374330e2 1160
51470298 1161static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1162{
51470298 1163 ssh1_pktout_size(ssh, len);
1164 ssh->pktout.type = type;
374330e2 1165}
1166
51470298 1167static int s_wrpkt_prepare(Ssh ssh)
32874aea 1168{
374330e2 1169 int pad, len, biglen, i;
1170 unsigned long crc;
1171
51470298 1172 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1173
a8327734 1174 if (ssh->logctx)
1175 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1176 ssh1_pkt_type(ssh->pktout.type),
1177 ssh->pktout.body, ssh->pktout.length);
00db133f 1178
51470298 1179 if (ssh->v1_compressing) {
4ba9b64b 1180 unsigned char *compblk;
1181 int complen;
5366aed8 1182 zlib_compress_block(ssh->cs_comp_ctx,
1183 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1184 &compblk, &complen);
51470298 1185 ssh1_pktout_size(ssh, complen - 1);
1186 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1187 sfree(compblk);
4ba9b64b 1188 }
1189
51470298 1190 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1191 pad = 8 - (len % 8);
374330e2 1192 biglen = len + pad;
1193
32874aea 1194 for (i = 0; i < pad; i++)
51470298 1195 ssh->pktout.data[i + 4] = random_byte();
1196 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1197 PUT_32BIT(ssh->pktout.data + biglen, crc);
1198 PUT_32BIT(ssh->pktout.data, len);
374330e2 1199
51470298 1200 if (ssh->cipher)
371e569c 1201 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1202
32874aea 1203 return biglen + 4;
39065bed 1204}
1205
51470298 1206static void s_wrpkt(Ssh ssh)
32874aea 1207{
5471d09a 1208 int len, backlog;
51470298 1209 len = s_wrpkt_prepare(ssh);
d8baa528 1210 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1211 if (backlog > SSH_MAX_BACKLOG)
51470298 1212 ssh_throttle_all(ssh, 1, backlog);
39065bed 1213}
1214
51470298 1215static void s_wrpkt_defer(Ssh ssh)
32874aea 1216{
39065bed 1217 int len;
51470298 1218 len = s_wrpkt_prepare(ssh);
1219 if (ssh->deferred_len + len > ssh->deferred_size) {
1220 ssh->deferred_size = ssh->deferred_len + len + 128;
1221 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1222 ssh->deferred_size);
39065bed 1223 }
51470298 1224 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1225 ssh->deferred_len += len;
374330e2 1226}
1227
fb09bf1c 1228/*
39065bed 1229 * Construct a packet with the specified contents.
fb09bf1c 1230 */
51470298 1231static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1232{
fb09bf1c 1233 unsigned char *p, *argp, argchar;
1234 unsigned long argint;
1235 int pktlen, argtype, arglen;
7cca0d81 1236 Bignum bn;
fb09bf1c 1237
1238 pktlen = 0;
39065bed 1239 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1240 switch (argtype) {
1241 case PKT_INT:
39065bed 1242 (void) va_arg(ap1, int);
fb09bf1c 1243 pktlen += 4;
1244 break;
1245 case PKT_CHAR:
1ec39246 1246 (void) va_arg(ap1, int);
fb09bf1c 1247 pktlen++;
1248 break;
1249 case PKT_DATA:
39065bed 1250 (void) va_arg(ap1, unsigned char *);
1251 arglen = va_arg(ap1, int);
fb09bf1c 1252 pktlen += arglen;
1253 break;
1254 case PKT_STR:
39065bed 1255 argp = va_arg(ap1, unsigned char *);
d8baa528 1256 arglen = strlen((char *)argp);
fb09bf1c 1257 pktlen += 4 + arglen;
1258 break;
7cca0d81 1259 case PKT_BIGNUM:
39065bed 1260 bn = va_arg(ap1, Bignum);
32874aea 1261 pktlen += ssh1_bignum_length(bn);
7cca0d81 1262 break;
fb09bf1c 1263 default:
1264 assert(0);
1265 }
1266 }
fb09bf1c 1267
51470298 1268 s_wrpkt_start(ssh, pkttype, pktlen);
1269 p = ssh->pktout.body;
fb09bf1c 1270
39065bed 1271 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1272 switch (argtype) {
1273 case PKT_INT:
39065bed 1274 argint = va_arg(ap2, int);
fb09bf1c 1275 PUT_32BIT(p, argint);
1276 p += 4;
1277 break;
1278 case PKT_CHAR:
1ec39246 1279 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1280 *p = argchar;
1281 p++;
1282 break;
1283 case PKT_DATA:
39065bed 1284 argp = va_arg(ap2, unsigned char *);
1285 arglen = va_arg(ap2, int);
fb09bf1c 1286 memcpy(p, argp, arglen);
1287 p += arglen;
1288 break;
1289 case PKT_STR:
39065bed 1290 argp = va_arg(ap2, unsigned char *);
d8baa528 1291 arglen = strlen((char *)argp);
fb09bf1c 1292 PUT_32BIT(p, arglen);
1293 memcpy(p + 4, argp, arglen);
1294 p += 4 + arglen;
1295 break;
7cca0d81 1296 case PKT_BIGNUM:
39065bed 1297 bn = va_arg(ap2, Bignum);
32874aea 1298 p += ssh1_write_bignum(p, bn);
7cca0d81 1299 break;
fb09bf1c 1300 }
1301 }
39065bed 1302}
fb09bf1c 1303
51470298 1304static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1305{
39065bed 1306 va_list ap1, ap2;
1307 va_start(ap1, pkttype);
1308 va_start(ap2, pkttype);
51470298 1309 construct_packet(ssh, pkttype, ap1, ap2);
1310 s_wrpkt(ssh);
fb09bf1c 1311}
1312
51470298 1313static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1314{
39065bed 1315 va_list ap1, ap2;
1316 va_start(ap1, pkttype);
1317 va_start(ap2, pkttype);
51470298 1318 construct_packet(ssh, pkttype, ap1, ap2);
1319 s_wrpkt_defer(ssh);
39065bed 1320}
1321
32874aea 1322static int ssh_versioncmp(char *a, char *b)
1323{
9697bfd2 1324 char *ae, *be;
1325 unsigned long av, bv;
1326
43aa02a7 1327 av = strtoul(a, &ae, 10);
1328 bv = strtoul(b, &be, 10);
32874aea 1329 if (av != bv)
1330 return (av < bv ? -1 : +1);
1331 if (*ae == '.')
1332 ae++;
1333 if (*be == '.')
1334 be++;
43aa02a7 1335 av = strtoul(ae, &ae, 10);
1336 bv = strtoul(be, &be, 10);
32874aea 1337 if (av != bv)
1338 return (av < bv ? -1 : +1);
9697bfd2 1339 return 0;
1340}
1341
e5574168 1342/*
a92dd380 1343 * Utility routines for putting an SSH-protocol `string' and
1344 * `uint32' into a SHA state.
e5574168 1345 */
1346#include <stdio.h>
32874aea 1347static void sha_string(SHA_State * s, void *str, int len)
1348{
e5574168 1349 unsigned char lenblk[4];
e5574168 1350 PUT_32BIT(lenblk, len);
e5574168 1351 SHA_Bytes(s, lenblk, 4);
e5574168 1352 SHA_Bytes(s, str, len);
1353}
1354
32874aea 1355static void sha_uint32(SHA_State * s, unsigned i)
1356{
a92dd380 1357 unsigned char intblk[4];
1358 PUT_32BIT(intblk, i);
1359 SHA_Bytes(s, intblk, 4);
1360}
1361
7cca0d81 1362/*
1363 * SSH2 packet construction functions.
1364 */
51470298 1365static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1366{
51470298 1367 if (ssh->pktout.maxlen < length) {
1368 ssh->pktout.maxlen = length + 256;
1369 ssh->pktout.data = srealloc(ssh->pktout.data,
1370 ssh->pktout.maxlen + APIEXTRA);
1371 if (!ssh->pktout.data)
32874aea 1372 fatalbox("Out of memory");
7cca0d81 1373 }
783415f8 1374}
51470298 1375static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1376{
51470298 1377 ssh->pktout.length += len;
1378 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1379 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1380}
51470298 1381static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1382{
51470298 1383 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1384}
51470298 1385static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1386{
51470298 1387 ssh->pktout.length = 5;
1388 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1389}
51470298 1390static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1391{
51470298 1392 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1393}
51470298 1394static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1395{
7cca0d81 1396 unsigned char x[4];
1397 PUT_32BIT(x, value);
51470298 1398 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1399}
51470298 1400static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1401{
51470298 1402 ssh2_pkt_adduint32(ssh, 0);
1403 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1404}
51470298 1405static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1406{
51470298 1407 ssh2_pkt_adddata(ssh, data, strlen(data));
1408 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1409 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1410}
51470298 1411static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1412{
51470298 1413 ssh2_pkt_adddata(ssh, data, len);
1414 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1415 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1416}
51470298 1417static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1418{
51470298 1419 ssh2_pkt_addstring_start(ssh);
1420 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1421}
d8baa528 1422static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1423{
7cca0d81 1424 unsigned char *p;
32874aea 1425 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1426 p = smalloc(n + 1);
7cca0d81 1427 if (!p)
32874aea 1428 fatalbox("out of memory");
7cca0d81 1429 p[0] = 0;
3709bfe9 1430 for (i = 1; i <= n; i++)
32874aea 1431 p[i] = bignum_byte(b, n - i);
7cca0d81 1432 i = 0;
32874aea 1433 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1434 i++;
1435 memmove(p, p + i, n + 1 - i);
1436 *len = n + 1 - i;
7cca0d81 1437 return p;
1438}
51470298 1439static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1440{
7cca0d81 1441 unsigned char *p;
1442 int len;
1443 p = ssh2_mpint_fmt(b, &len);
51470298 1444 ssh2_pkt_addstring_start(ssh);
d8baa528 1445 ssh2_pkt_addstring_data(ssh, (char *)p, len);
dcbde236 1446 sfree(p);
7cca0d81 1447}
b185170a 1448
1449/*
1450 * Construct an SSH2 final-form packet: compress it, encrypt it,
1451 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1452 * ssh->pktout.data. Total length is returned.
b185170a 1453 */
51470298 1454static int ssh2_pkt_construct(Ssh ssh)
32874aea 1455{
7cca0d81 1456 int cipherblk, maclen, padding, i;
7cca0d81 1457
a8327734 1458 if (ssh->logctx)
1459 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1460 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1461 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1462
7cca0d81 1463 /*
4ba9b64b 1464 * Compress packet payload.
1465 */
4ba9b64b 1466 {
1467 unsigned char *newpayload;
1468 int newlen;
51470298 1469 if (ssh->cscomp &&
5366aed8 1470 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1471 ssh->pktout.length - 5,
51470298 1472 &newpayload, &newlen)) {
1473 ssh->pktout.length = 5;
1474 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1475 sfree(newpayload);
4ba9b64b 1476 }
1477 }
1478
1479 /*
7cca0d81 1480 * Add padding. At least four bytes, and must also bring total
1481 * length (minus MAC) up to a multiple of the block size.
1482 */
51470298 1483 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1484 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1485 padding = 4;
32874aea 1486 padding +=
51470298 1487 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1488 maclen = ssh->csmac ? ssh->csmac->len : 0;
1489 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1490 ssh->pktout.data[4] = padding;
7cca0d81 1491 for (i = 0; i < padding; i++)
51470298 1492 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1493 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1494 if (ssh->csmac)
e0e1a00d 1495 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1496 ssh->pktout.length + padding,
51470298 1497 ssh->v2_outgoing_sequence);
1498 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1499
1500 if (ssh->cscipher)
371e569c 1501 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1502 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1503
1504 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1505 return ssh->pktout.length + padding + maclen;
b185170a 1506}
1507
1508/*
1509 * Construct and send an SSH2 packet immediately.
1510 */
51470298 1511static void ssh2_pkt_send(Ssh ssh)
32874aea 1512{
5471d09a 1513 int len;
1514 int backlog;
51470298 1515 len = ssh2_pkt_construct(ssh);
d8baa528 1516 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1517 if (backlog > SSH_MAX_BACKLOG)
51470298 1518 ssh_throttle_all(ssh, 1, backlog);
b185170a 1519}
1520
1521/*
1522 * Construct an SSH2 packet and add it to a deferred data block.
1523 * Useful for sending multiple packets in a single sk_write() call,
1524 * to prevent a traffic-analysing listener from being able to work
1525 * out the length of any particular packet (such as the password
1526 * packet).
1527 *
1528 * Note that because SSH2 sequence-numbers its packets, this can
1529 * NOT be used as an m4-style `defer' allowing packets to be
1530 * constructed in one order and sent in another.
1531 */
51470298 1532static void ssh2_pkt_defer(Ssh ssh)
32874aea 1533{
51470298 1534 int len = ssh2_pkt_construct(ssh);
1535 if (ssh->deferred_len + len > ssh->deferred_size) {
1536 ssh->deferred_size = ssh->deferred_len + len + 128;
1537 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1538 ssh->deferred_size);
b185170a 1539 }
51470298 1540 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1541 ssh->deferred_len += len;
b185170a 1542}
1543
1544/*
1545 * Send the whole deferred data block constructed by
39065bed 1546 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1547 */
51470298 1548static void ssh_pkt_defersend(Ssh ssh)
32874aea 1549{
5471d09a 1550 int backlog;
d8baa528 1551 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1552 ssh->deferred_len);
51470298 1553 ssh->deferred_len = ssh->deferred_size = 0;
1554 sfree(ssh->deferred_send_data);
1555 ssh->deferred_send_data = NULL;
5471d09a 1556 if (backlog > SSH_MAX_BACKLOG)
51470298 1557 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1558}
1559
1560#if 0
32874aea 1561void bndebug(char *string, Bignum b)
1562{
7cca0d81 1563 unsigned char *p;
1564 int i, len;
1565 p = ssh2_mpint_fmt(b, &len);
1566 debug(("%s", string));
1567 for (i = 0; i < len; i++)
32874aea 1568 debug((" %02x", p[i]));
765c4200 1569 debug(("\n"));
dcbde236 1570 sfree(p);
7cca0d81 1571}
1572#endif
1573
32874aea 1574static void sha_mpint(SHA_State * s, Bignum b)
1575{
7cca0d81 1576 unsigned char *p;
1577 int len;
1578 p = ssh2_mpint_fmt(b, &len);
1579 sha_string(s, p, len);
dcbde236 1580 sfree(p);
7cca0d81 1581}
1582
1583/*
1584 * SSH2 packet decode functions.
1585 */
51470298 1586static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1587{
7cca0d81 1588 unsigned long value;
51470298 1589 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1590 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1591 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1592 ssh->pktin.savedpos += 4;
7cca0d81 1593 return value;
1594}
51470298 1595static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1596{
65a22376 1597 unsigned long value;
51470298 1598 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1599 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1600 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1601 ssh->pktin.savedpos++;
65a22376 1602 return value;
1603}
51470298 1604static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1605{
57356d63 1606 int len;
7cca0d81 1607 *p = NULL;
45068b27 1608 *length = 0;
51470298 1609 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1610 return;
57356d63 1611 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1612 if (len < 0)
1613 return;
1614 *length = len;
51470298 1615 ssh->pktin.savedpos += 4;
1616 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1617 return;
d8baa528 1618 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
51470298 1619 ssh->pktin.savedpos += *length;
7cca0d81 1620}
51470298 1621static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1622{
7cca0d81 1623 char *p;
3709bfe9 1624 int length;
7cca0d81 1625 Bignum b;
1626
51470298 1627 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1628 if (!p)
32874aea 1629 return NULL;
8d5de777 1630 if (p[0] & 0x80) {
a8327734 1631 bombout((ssh,"internal error: Can't handle negative mpints"));
32874aea 1632 return NULL;
8d5de777 1633 }
d8baa528 1634 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1635 return b;
1636}
1637
7d503c31 1638/*
1dd353b5 1639 * Helper function to add an SSH2 signature blob to a packet.
1640 * Expects to be shown the public key blob as well as the signature
1641 * blob. Normally works just like ssh2_pkt_addstring, but will
1642 * fiddle with the signature packet if necessary for
1643 * BUG_SSH2_RSA_PADDING.
1644 */
51470298 1645static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1646 void *sigblob_v, int sigblob_len)
1647{
1648 unsigned char *pkblob = (unsigned char *)pkblob_v;
1649 unsigned char *sigblob = (unsigned char *)sigblob_v;
1650
1651 /* dmemdump(pkblob, pkblob_len); */
1652 /* dmemdump(sigblob, sigblob_len); */
1653
1654 /*
1655 * See if this is in fact an ssh-rsa signature and a buggy
1656 * server; otherwise we can just do this the easy way.
1657 */
51470298 1658 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1659 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1660 int pos, len, siglen;
1661
1662 /*
1663 * Find the byte length of the modulus.
1664 */
1665
1666 pos = 4+7; /* skip over "ssh-rsa" */
1667 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1668 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1669 pos += 4; /* find modulus itself */
1670 while (len > 0 && pkblob[pos] == 0)
1671 len--, pos++;
1672 /* debug(("modulus length is %d\n", len)); */
1673
1674 /*
1675 * Now find the signature integer.
1676 */
1677 pos = 4+7; /* skip over "ssh-rsa" */
1678 siglen = GET_32BIT(sigblob+pos);
1679 /* debug(("signature length is %d\n", siglen)); */
1680
1681 if (len != siglen) {
1682 unsigned char newlen[4];
51470298 1683 ssh2_pkt_addstring_start(ssh);
d8baa528 1684 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1dd353b5 1685 /* dmemdump(sigblob, pos); */
1686 pos += 4; /* point to start of actual sig */
1687 PUT_32BIT(newlen, len);
d8baa528 1688 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1dd353b5 1689 /* dmemdump(newlen, 4); */
1690 newlen[0] = 0;
1691 while (len-- > siglen) {
d8baa528 1692 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1dd353b5 1693 /* dmemdump(newlen, 1); */
1694 }
d8baa528 1695 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1dd353b5 1696 /* dmemdump(sigblob+pos, siglen); */
1697 return;
1698 }
1699
1700 /* Otherwise fall through and do it the easy way. */
1701 }
1702
51470298 1703 ssh2_pkt_addstring_start(ssh);
d8baa528 1704 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1dd353b5 1705}
1706
1707/*
7d503c31 1708 * Examine the remote side's version string and compare it against
1709 * a list of known buggy implementations.
1710 */
51470298 1711static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1712{
1713 char *imp; /* pointer to implementation part */
7d503c31 1714 imp = vstring;
1715 imp += strcspn(imp, "-");
bd358db1 1716 if (*imp) imp++;
7d503c31 1717 imp += strcspn(imp, "-");
bd358db1 1718 if (*imp) imp++;
7d503c31 1719
51470298 1720 ssh->remote_bugs = 0;
7d503c31 1721
5ecd7ad0 1722 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1723 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1724 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1725 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1726 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1727 /*
1728 * These versions don't support SSH1_MSG_IGNORE, so we have
1729 * to use a different defence against password length
1730 * sniffing.
1731 */
51470298 1732 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1733 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1734 }
1735
5ecd7ad0 1736 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1737 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2c9c6388 1738 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1739 /*
1740 * These versions need a plain password sent; they can't
1741 * handle having a null and a random length of data after
1742 * the password.
1743 */
51470298 1744 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1745 logevent("We believe remote version needs a plain SSH1 password");
1746 }
1747
5ecd7ad0 1748 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1749 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 1750 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1751 /*
1752 * These versions apparently have no clue whatever about
1753 * RSA authentication and will panic and die if they see
1754 * an AUTH_RSA message.
1755 */
51470298 1756 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1757 logevent("We believe remote version can't handle RSA authentication");
1758 }
1759
5ecd7ad0 1760 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1761 (ssh->cfg.sshbug_hmac2 == AUTO &&
831301f6 1762 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1763 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1764 wc_match("2.1 *", imp)))) {
32874aea 1765 /*
1766 * These versions have the HMAC bug.
1767 */
51470298 1768 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1769 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1770 }
1dd353b5 1771
5ecd7ad0 1772 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1773 (ssh->cfg.sshbug_derivekey2 == AUTO &&
d6430b97 1774 (wc_match("2.0.0*", imp) || wc_match("2.0.1[01]*", imp) ))) {
088bde77 1775 /*
1776 * These versions have the key-derivation bug (failing to
1777 * include the literal shared secret in the hashes that
1778 * generate the keys).
1779 */
51470298 1780 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1781 logevent("We believe remote version has SSH2 key-derivation bug");
1782 }
1783
5ecd7ad0 1784 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1785 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 1786 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1787 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 1788 /*
1789 * These versions have the SSH2 RSA padding bug.
1790 */
51470298 1791 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1792 logevent("We believe remote version has SSH2 RSA padding bug");
1793 }
8e975795 1794
5ecd7ad0 1795 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 1796 /*
831301f6 1797 * User specified the SSH2 DH GEX bug.
8e975795 1798 */
51470298 1799 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1800 logevent("We believe remote version has SSH2 DH group exchange bug");
1801 }
7d503c31 1802}
1803
51470298 1804static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1805{
51470298 1806 struct do_ssh_init_state {
1807 int vslen;
1808 char version[10];
1809 char *vstring;
1810 int vstrsize;
1811 int i;
1812 int proto1, proto2;
1813 };
1814 crState(do_ssh_init_state);
374330e2 1815
51470298 1816 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1817
1818 /* Search for the string "SSH-" in the input. */
51470298 1819 s->i = 0;
8df7a775 1820 while (1) {
1821 static const int transS[] = { 1, 2, 2, 1 };
1822 static const int transH[] = { 0, 0, 3, 0 };
1823 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1824 if (c == 'S')
51470298 1825 s->i = transS[s->i];
32874aea 1826 else if (c == 'H')
51470298 1827 s->i = transH[s->i];
32874aea 1828 else if (c == '-')
51470298 1829 s->i = transminus[s->i];
32874aea 1830 else
51470298 1831 s->i = 0;
1832 if (s->i < 0)
8df7a775 1833 break;
1834 crReturn(1); /* get another character */
374330e2 1835 }
8df7a775 1836
51470298 1837 s->vstrsize = 16;
1838 s->vstring = smalloc(s->vstrsize);
1839 strcpy(s->vstring, "SSH-");
1840 s->vslen = 4;
1841 s->i = 0;
374330e2 1842 while (1) {
8df7a775 1843 crReturn(1); /* get another char */
51470298 1844 if (s->vslen >= s->vstrsize - 1) {
1845 s->vstrsize += 16;
1846 s->vstring = srealloc(s->vstring, s->vstrsize);
32874aea 1847 }
51470298 1848 s->vstring[s->vslen++] = c;
1849 if (s->i >= 0) {
374330e2 1850 if (c == '-') {
51470298 1851 s->version[s->i] = '\0';
1852 s->i = -1;
1853 } else if (s->i < sizeof(s->version) - 1)
1854 s->version[s->i++] = c;
c4ffc4d0 1855 } else if (c == '\012')
374330e2 1856 break;
1857 }
1858
51470298 1859 ssh->agentfwd_enabled = FALSE;
1860 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1861
51470298 1862 s->vstring[s->vslen] = 0;
1863 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1864 {
1865 char *vlog;
1866 vlog = smalloc(20 + s->vslen);
1867 sprintf(vlog, "Server version: %s", s->vstring);
1868 logevent(vlog);
1869 sfree(vlog);
1870 }
1871 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1872
adf799dd 1873 /*
38d228a2 1874 * Decide which SSH protocol version to support.
adf799dd 1875 */
38d228a2 1876
1877 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1878 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1879 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1880 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1881
86916870 1882 if (ssh->cfg.sshprot == 0 && !s->proto1) {
a8327734 1883 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
38d228a2 1884 crReturn(0);
1885 }
86916870 1886 if (ssh->cfg.sshprot == 3 && !s->proto2) {
a8327734 1887 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
38d228a2 1888 crReturn(0);
1889 }
1890
86916870 1891 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1892 /*
38d228a2 1893 * Use v2 protocol.
32874aea 1894 */
1895 char verstring[80], vlog[100];
1896 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1897 SHA_Init(&ssh->exhashbase);
32874aea 1898 /*
1899 * Hash our version string and their version string.
1900 */
51470298 1901 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1902 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1903 sprintf(vlog, "We claim version: %s", verstring);
1904 logevent(vlog);
c4ffc4d0 1905 strcat(verstring, "\012");
32874aea 1906 logevent("Using SSH protocol version 2");
51470298 1907 sk_write(ssh->s, verstring, strlen(verstring));
1908 ssh->protocol = ssh2_protocol;
1909 ssh->version = 2;
1910 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1911 } else {
32874aea 1912 /*
38d228a2 1913 * Use v1 protocol.
32874aea 1914 */
1915 char verstring[80], vlog[100];
1916 sprintf(verstring, "SSH-%s-%s",
51470298 1917 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1918 sshver);
1919 sprintf(vlog, "We claim version: %s", verstring);
1920 logevent(vlog);
c4ffc4d0 1921 strcat(verstring, "\012");
759712a6 1922
32874aea 1923 logevent("Using SSH protocol version 1");
51470298 1924 sk_write(ssh->s, verstring, strlen(verstring));
1925 ssh->protocol = ssh1_protocol;
1926 ssh->version = 1;
1927 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1928 }
51470298 1929 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1930
51470298 1931 sfree(s->vstring);
50526e47 1932
8df7a775 1933 crFinish(0);
1934}
1935
51470298 1936static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 1937{
51470298 1938 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 1939
1940 /*
1941 * To begin with, feed the characters one by one to the
1942 * protocol initialisation / selection function do_ssh_init().
1943 * When that returns 0, we're done with the initial greeting
1944 * exchange and can move on to packet discipline.
1945 */
1946 while (1) {
51470298 1947 int ret; /* need not be kept across crReturn */
8df7a775 1948 if (datalen == 0)
1949 crReturnV; /* more data please */
51470298 1950 ret = do_ssh_init(ssh, *data);
32874aea 1951 data++;
1952 datalen--;
8df7a775 1953 if (ret == 0)
1954 break;
1955 }
1956
1957 /*
1958 * We emerge from that loop when the initial negotiation is
1959 * over and we have selected an s_rdpkt function. Now pass
1960 * everything to s_rdpkt, and then pass the resulting packets
1961 * to the proper protocol handler.
1962 */
1963 if (datalen == 0)
1964 crReturnV;
1965 while (1) {
1966 while (datalen > 0) {
51470298 1967 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1968 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 1969 return;
1970 }
51470298 1971 ssh->protocol(ssh, NULL, 0, 1);
1972 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 1973 return;
1974 }
1975 }
1976 }
1977 crReturnV;
1978 }
1979 crFinishV;
1980}
1981
32874aea 1982static int ssh_closing(Plug plug, char *error_msg, int error_code,
1983 int calling_back)
1984{
51470298 1985 Ssh ssh = (Ssh) plug;
1986 ssh->state = SSH_STATE_CLOSED;
1987 if (ssh->s) {
1988 sk_close(ssh->s);
1989 ssh->s = NULL;
f3ab576e 1990 }
7e78000d 1991 if (error_msg) {
32874aea 1992 /* A socket error has occurred. */
247308b5 1993 logevent(error_msg);
a8327734 1994 connection_fatal(ssh->frontend, error_msg);
7e78000d 1995 } else {
1996 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1997 }
7e78000d 1998 return 0;
1999}
2000
32874aea 2001static int ssh_receive(Plug plug, int urgent, char *data, int len)
2002{
51470298 2003 Ssh ssh = (Ssh) plug;
d8baa528 2004 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2005 if (ssh->state == SSH_STATE_CLOSED) {
2006 if (ssh->s) {
2007 sk_close(ssh->s);
2008 ssh->s = NULL;
32874aea 2009 }
2010 return 0;
3257deae 2011 }
fef97f43 2012 return 1;
374330e2 2013}
2014
5471d09a 2015static void ssh_sent(Plug plug, int bufsize)
2016{
51470298 2017 Ssh ssh = (Ssh) plug;
5471d09a 2018 /*
2019 * If the send backlog on the SSH socket itself clears, we
2020 * should unthrottle the whole world if it was throttled.
2021 */
2022 if (bufsize < SSH_MAX_BACKLOG)
51470298 2023 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2024}
2025
fb09bf1c 2026/*
8df7a775 2027 * Connect to specified host and port.
2028 * Returns an error message, or NULL on success.
6e1ebb76 2029 * Also places the canonical host name into `realhost'. It must be
2030 * freed by the caller.
8df7a775 2031 */
51470298 2032static char *connect_to_host(Ssh ssh, char *host, int port,
2033 char **realhost, int nodelay)
8df7a775 2034{
51470298 2035 static const struct plug_function_table fn_table = {
7e78000d 2036 ssh_closing,
5471d09a 2037 ssh_receive,
2038 ssh_sent,
2039 NULL
51470298 2040 };
7e78000d 2041
8df7a775 2042 SockAddr addr;
2043 char *err;
8df7a775 2044
51470298 2045 ssh->savedhost = smalloc(1 + strlen(host));
2046 if (!ssh->savedhost)
8df7a775 2047 fatalbox("Out of memory");
51470298 2048 strcpy(ssh->savedhost, host);
8df7a775 2049
2050 if (port < 0)
2051 port = 22; /* default ssh port */
51470298 2052 ssh->savedport = port;
8df7a775 2053
2054 /*
2055 * Try to find host.
2056 */
57356d63 2057 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2058 addr = name_lookup(host, port, realhost, &ssh->cfg);
70e5d0fd 2059 if ((err = sk_addr_error(addr)) != NULL)
8df7a775 2060 return err;
2061
8df7a775 2062 /*
2063 * Open socket.
2064 */
3ad9d396 2065 {
57356d63 2066 char addrbuf[100];
3ad9d396 2067 sk_getaddr(addr, addrbuf, 100);
57356d63 2068 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2069 }
51470298 2070 ssh->fn = &fn_table;
e8fa8f62 2071 ssh->s = new_connection(addr, *realhost, port,
2072 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
70e5d0fd 2073 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2074 ssh->s = NULL;
8df7a775 2075 return err;
67c4ba2e 2076 }
8df7a775 2077
8df7a775 2078 return NULL;
2079}
2080
2081/*
5471d09a 2082 * Throttle or unthrottle the SSH connection.
2083 */
51470298 2084static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2085{
51470298 2086 int old_count = ssh->v1_throttle_count;
2087 ssh->v1_throttle_count += adjust;
2088 assert(ssh->v1_throttle_count >= 0);
2089 if (ssh->v1_throttle_count && !old_count) {
2090 sk_set_frozen(ssh->s, 1);
2091 } else if (!ssh->v1_throttle_count && old_count) {
2092 sk_set_frozen(ssh->s, 0);
5471d09a 2093 }
2094}
2095
2096/*
2097 * Throttle or unthrottle _all_ local data streams (for when sends
2098 * on the SSH connection itself back up).
2099 */
51470298 2100static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2101{
2102 int i;
2103 struct ssh_channel *c;
2104
51470298 2105 if (enable == ssh->throttled_all)
5471d09a 2106 return;
51470298 2107 ssh->throttled_all = enable;
2108 ssh->overall_bufsize = bufsize;
2109 if (!ssh->channels)
5471d09a 2110 return;
51470298 2111 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2112 switch (c->type) {
2113 case CHAN_MAINSESSION:
2114 /*
2115 * This is treated separately, outside the switch.
2116 */
2117 break;
2118 case CHAN_X11:
2119 x11_override_throttle(c->u.x11.s, enable);
2120 break;
2121 case CHAN_AGENT:
2122 /* Agent channels require no buffer management. */
2123 break;
2124 case CHAN_SOCKDATA:
2125 pfd_override_throttle(c->u.x11.s, enable);
2126 break;
2127 }
2128 }
2129}
2130
2131/*
51470298 2132 * Username and password input, abstracted off into routines
2133 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2134 */
0405e71f 2135
2136/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2137static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2138{
51470298 2139 ssh->userpass_input_buffer = buffer;
2140 ssh->userpass_input_buflen = buflen;
2141 ssh->userpass_input_bufpos = 0;
2142 ssh->userpass_input_echo = echo;
0405e71f 2143}
2144
2145/*
2146 * Process some terminal data in the course of username/password
2147 * input. Returns >0 for success (line of input returned in
2148 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2149 * for inconclusive (keep waiting for more input please).
2150 */
ae9ae89f 2151static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2152{
2153 char c;
2154
2155 while (inlen--) {
2156 switch (c = *in++) {
2157 case 10:
2158 case 13:
51470298 2159 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2160 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2161 return +1;
2162 break;
2163 case 8:
2164 case 127:
51470298 2165 if (ssh->userpass_input_bufpos > 0) {
2166 if (ssh->userpass_input_echo)
2167 c_write_str(ssh, "\b \b");
2168 ssh->userpass_input_bufpos--;
0405e71f 2169 }
2170 break;
2171 case 21:
2172 case 27:
51470298 2173 while (ssh->userpass_input_bufpos > 0) {
2174 if (ssh->userpass_input_echo)
2175 c_write_str(ssh, "\b \b");
2176 ssh->userpass_input_bufpos--;
0405e71f 2177 }
2178 break;
2179 case 3:
2180 case 4:
2181 return -1;
2182 break;
2183 default:
2184 if (((c >= ' ' && c <= '~') ||
2185 ((unsigned char) c >= 160))
51470298 2186 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2187 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2188 if (ssh->userpass_input_echo)
2189 c_write(ssh, &c, 1);
0405e71f 2190 }
2191 break;
2192 }
2193 }
2194 return 0;
2195}
2196
2197/*
fb09bf1c 2198 * Handle the key exchange and user authentication phases.
2199 */
51470298 2200static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2201{
2d466ffd 2202 int i, j;
374330e2 2203 unsigned char cookie[8];
2204 struct RSAKey servkey, hostkey;
2205 struct MD5Context md5c;
51470298 2206 struct do_ssh1_login_state {
2207 int len;
2208 unsigned char *rsabuf, *keystr1, *keystr2;
2209 unsigned long supported_ciphers_mask, supported_auths_mask;
2210 int tried_publickey, tried_agent;
2211 int tis_auth_refused, ccard_auth_refused;
2212 unsigned char session_id[16];
2213 int cipher_type;
2214 char username[100];
2215 void *publickey_blob;
2216 int publickey_bloblen;
2217 char password[100];
2218 char prompt[200];
2219 int pos;
2220 char c;
2221 int pwpkt_type;
2222 unsigned char request[5], *response, *p;
2223 int responselen;
2224 int keyi, nkeys;
2225 int authed;
2226 struct RSAKey key;
2227 Bignum challenge;
2228 char *commentp;
2229 int commentlen;
2230 };
2231 crState(do_ssh1_login_state);
2232
2233 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2234
32874aea 2235 if (!ispkt)
2236 crWaitUntil(ispkt);
374330e2 2237
51470298 2238 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
a8327734 2239 bombout((ssh,"Public key packet not received"));
32874aea 2240 crReturn(0);
8d5de777 2241 }
374330e2 2242
c5e9c988 2243 logevent("Received public keys");
374330e2 2244
51470298 2245 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2246
51470298 2247 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2248 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2249
c5e9c988 2250 /*
1c2a93c4 2251 * Log the host key fingerprint.
c5e9c988 2252 */
c5e9c988 2253 {
2254 char logmsg[80];
1c2a93c4 2255 logevent("Host key fingerprint is:");
c5e9c988 2256 strcpy(logmsg, " ");
32874aea 2257 hostkey.comment = NULL;
2258 rsa_fingerprint(logmsg + strlen(logmsg),
2259 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2260 logevent(logmsg);
2261 }
2262
51470298 2263 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2264 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2265 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2266
51470298 2267 ssh->v1_local_protoflags =
2268 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2269 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2270
c5e9c988 2271 MD5Init(&md5c);
51470298 2272 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2273 MD5Update(&md5c, s->keystr1, servkey.bytes);
2274 MD5Update(&md5c, ssh->pktin.body, 8);
2275 MD5Final(s->session_id, &md5c);
374330e2 2276
32874aea 2277 for (i = 0; i < 32; i++)
51470298 2278 ssh->session_key[i] = random_byte();
374330e2 2279
51470298 2280 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2281
51470298 2282 s->rsabuf = smalloc(s->len);
2283 if (!s->rsabuf)
374330e2 2284 fatalbox("Out of memory");
2285
89ee5268 2286 /*
2287 * Verify the host key.
2288 */
2289 {
32874aea 2290 /*
2291 * First format the key into a string.
2292 */
2293 int len = rsastr_len(&hostkey);
2294 char fingerprint[100];
2295 char *keystr = smalloc(len);
2296 if (!keystr)
2297 fatalbox("Out of memory");
2298 rsastr_fmt(keystr, &hostkey);
2299 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2300 verify_ssh_host_key(ssh->frontend,
2301 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2302 fingerprint);
2303 sfree(keystr);
2304 }
2305
2306 for (i = 0; i < 32; i++) {
51470298 2307 s->rsabuf[i] = ssh->session_key[i];
374330e2 2308 if (i < 16)
51470298 2309 s->rsabuf[i] ^= s->session_id[i];
374330e2 2310 }
2311
2312 if (hostkey.bytes > servkey.bytes) {
51470298 2313 rsaencrypt(s->rsabuf, 32, &servkey);
2314 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2315 } else {
51470298 2316 rsaencrypt(s->rsabuf, 32, &hostkey);
2317 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2318 }
2319
c5e9c988 2320 logevent("Encrypted session key");
2321
ca20bfcf 2322 {
2323 int cipher_chosen = 0, warn = 0;
2324 char *cipher_string = NULL;
51470298 2325 int i;
ca20bfcf 2326 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2327 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2328 if (next_cipher == CIPHER_WARN) {
2329 /* If/when we choose a cipher, warn about it */
2330 warn = 1;
2331 } else if (next_cipher == CIPHER_AES) {
2332 /* XXX Probably don't need to mention this. */
2333 logevent("AES not supported in SSH1, skipping");
2334 } else {
2335 switch (next_cipher) {
51470298 2336 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2337 cipher_string = "3DES"; break;
51470298 2338 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2339 cipher_string = "Blowfish"; break;
51470298 2340 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2341 cipher_string = "single-DES"; break;
2342 }
51470298 2343 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2344 cipher_chosen = 1;
2345 }
2346 }
2347 if (!cipher_chosen) {
51470298 2348 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
a8327734 2349 bombout((ssh,"Server violates SSH 1 protocol by not "
ca20bfcf 2350 "supporting 3DES encryption"));
2351 else
2352 /* shouldn't happen */
a8327734 2353 bombout((ssh,"No supported ciphers found"));
a99a05c0 2354 crReturn(0);
2355 }
ca20bfcf 2356
2357 /* Warn about chosen cipher if necessary. */
2358 if (warn)
a8327734 2359 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2360 }
ca20bfcf 2361
51470298 2362 switch (s->cipher_type) {
32874aea 2363 case SSH_CIPHER_3DES:
2364 logevent("Using 3DES encryption");
2365 break;
2366 case SSH_CIPHER_DES:
2367 logevent("Using single-DES encryption");
2368 break;
2369 case SSH_CIPHER_BLOWFISH:
2370 logevent("Using Blowfish encryption");
2371 break;
c5e9c988 2372 }
bea1ef5f 2373
51470298 2374 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2375 PKT_CHAR, s->cipher_type,
32874aea 2376 PKT_DATA, cookie, 8,
51470298 2377 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2378 PKT_DATA, s->rsabuf, s->len,
2379 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2380
c5e9c988 2381 logevent("Trying to enable encryption...");
374330e2 2382
51470298 2383 sfree(s->rsabuf);
374330e2 2384
51470298 2385 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2386 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2387 &ssh_3des);
371e569c 2388 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2389 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2390 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2391
0183b242 2392 ssh->crcda_ctx = crcda_make_context();
2393 logevent("Installing CRC compensation attack detector");
2394
fb09bf1c 2395 crWaitUntil(ispkt);
374330e2 2396
51470298 2397 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2398 bombout((ssh,"Encryption not successfully enabled"));
32874aea 2399 crReturn(0);
8d5de777 2400 }
374330e2 2401
c5e9c988 2402 logevent("Successfully started encryption");
2403
374330e2 2404 fflush(stdout);
2405 {
86916870 2406 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 2407 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2408 if (!ssh_get_line("login as: ",
51470298 2409 s->username, sizeof(s->username), FALSE)) {
32874aea 2410 /*
2411 * get_line failed to get a username.
2412 * Terminate.
2413 */
2414 logevent("No username provided. Abandoning session.");
51470298 2415 ssh->state = SSH_STATE_CLOSED;
32874aea 2416 crReturn(1);
2417 }
2418 } else {
51470298 2419 int ret; /* need not be kept over crReturn */
2420 c_write_str(ssh, "login as: ");
2421 ssh->send_ok = 1;
0405e71f 2422
51470298 2423 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2424 do {
32874aea 2425 crWaitUntil(!ispkt);
51470298 2426 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2427 } while (ret == 0);
2428 if (ret < 0)
2429 cleanup_exit(0);
51470298 2430 c_write_str(ssh, "\r\n");
32874aea 2431 }
2432 } else {
86916870 2433 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2434 s->username[sizeof(s->username)-1] = '\0';
374330e2 2435 }
fb09bf1c 2436
51470298 2437 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2438 {
51470298 2439 char userlog[22 + sizeof(s->username)];
2440 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2441 logevent(userlog);
32874aea 2442 if (flags & FLAG_INTERACTIVE &&
2443 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2444 strcat(userlog, "\r\n");
51470298 2445 c_write_str(ssh, userlog);
3c8e959b 2446 }
c5e9c988 2447 }
374330e2 2448 }
2449
fb09bf1c 2450 crWaitUntil(ispkt);
374330e2 2451
51470298 2452 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2453 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2454 s->tried_publickey = s->tried_agent = 1;
0df73905 2455 } else {
51470298 2456 s->tried_publickey = s->tried_agent = 0;
0df73905 2457 }
51470298 2458 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2459 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2460 if (!filename_is_null(ssh->cfg.keyfile)) {
2461 if (!rsakey_pubblob(&ssh->cfg.keyfile,
51470298 2462 &s->publickey_blob, &s->publickey_bloblen))
2463 s->publickey_blob = NULL;
396778f1 2464 } else
51470298 2465 s->publickey_blob = NULL;
7cca0d81 2466
51470298 2467 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2468 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2469
51470298 2470 if (agent_exists() && !s->tried_agent) {
32874aea 2471 /*
2472 * Attempt RSA authentication using Pageant.
2473 */
32874aea 2474 void *r;
2475
51470298 2476 s->authed = FALSE;
2477 s->tried_agent = 1;
32874aea 2478 logevent("Pageant is running. Requesting keys.");
2479
2480 /* Request the keys held by the agent. */
51470298 2481 PUT_32BIT(s->request, 1);
2482 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2483 agent_query(s->request, 5, &r, &s->responselen);
2484 s->response = (unsigned char *) r;
2485 if (s->response && s->responselen >= 5 &&
2486 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2487 s->p = s->response + 5;
2488 s->nkeys = GET_32BIT(s->p);
2489 s->p += 4;
32874aea 2490 {
2491 char buf[64];
51470298 2492 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2493 logevent(buf);
2494 }
51470298 2495 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2496 {
2497 char buf[64];
51470298 2498 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2499 logevent(buf);
2500 }
51470298 2501 if (s->publickey_blob &&
2502 !memcmp(s->p, s->publickey_blob,
2503 s->publickey_bloblen)) {
396778f1 2504 logevent("This key matches configured key file");
51470298 2505 s->tried_publickey = 1;
396778f1 2506 }
51470298 2507 s->p += 4;
2508 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2509 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2510 s->commentlen = GET_32BIT(s->p);
2511 s->p += 4;
d8baa528 2512 s->commentp = (char *)s->p;
51470298 2513 s->p += s->commentlen;
2514 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2515 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2516 crWaitUntil(ispkt);
51470298 2517 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2518 logevent("Key refused");
2519 continue;
2520 }
2521 logevent("Received RSA challenge");
51470298 2522 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2523 {
2524 char *agentreq, *q, *ret;
2d466ffd 2525 void *vret;
32874aea 2526 int len, retlen;
2527 len = 1 + 4; /* message type, bit count */
51470298 2528 len += ssh1_bignum_length(s->key.exponent);
2529 len += ssh1_bignum_length(s->key.modulus);
2530 len += ssh1_bignum_length(s->challenge);
32874aea 2531 len += 16; /* session id */
2532 len += 4; /* response format */
2533 agentreq = smalloc(4 + len);
2534 PUT_32BIT(agentreq, len);
2535 q = agentreq + 4;
2536 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2537 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2538 q += 4;
51470298 2539 q += ssh1_write_bignum(q, s->key.exponent);
2540 q += ssh1_write_bignum(q, s->key.modulus);
2541 q += ssh1_write_bignum(q, s->challenge);
2542 memcpy(q, s->session_id, 16);
32874aea 2543 q += 16;
2544 PUT_32BIT(q, 1); /* response format */
2d466ffd 2545 agent_query(agentreq, len + 4, &vret, &retlen);
2546 ret = vret;
32874aea 2547 sfree(agentreq);
2548 if (ret) {
2549 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2550 logevent("Sending Pageant's response");
51470298 2551 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2552 PKT_DATA, ret + 5, 16,
2553 PKT_END);
2554 sfree(ret);
2555 crWaitUntil(ispkt);
51470298 2556 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2557 logevent
2558 ("Pageant's response accepted");
2559 if (flags & FLAG_VERBOSE) {
51470298 2560 c_write_str(ssh, "Authenticated using"
2561 " RSA key \"");
2562 c_write(ssh, s->commentp,
2563 s->commentlen);
2564 c_write_str(ssh, "\" from agent\r\n");
32874aea 2565 }
51470298 2566 s->authed = TRUE;
32874aea 2567 } else
2568 logevent
2569 ("Pageant's response not accepted");
2570 } else {
2571 logevent
2572 ("Pageant failed to answer challenge");
2573 sfree(ret);
2574 }
2575 } else {
2576 logevent("No reply received from Pageant");
2577 }
2578 }
51470298 2579 freebn(s->key.exponent);
2580 freebn(s->key.modulus);
2581 freebn(s->challenge);
2582 if (s->authed)
32874aea 2583 break;
2584 }
2585 }
51470298 2586 if (s->authed)
32874aea 2587 break;
2588 }
9a30e26b 2589 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 2590 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2591
86916870 2592 if (ssh->cfg.try_tis_auth &&
51470298 2593 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2594 !s->tis_auth_refused) {
2595 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2596 logevent("Requested TIS authentication");
51470298 2597 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2598 crWaitUntil(ispkt);
51470298 2599 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2600 logevent("TIS authentication declined");
2601 if (flags & FLAG_INTERACTIVE)
51470298 2602 c_write_str(ssh, "TIS authentication refused.\r\n");
2603 s->tis_auth_refused = 1;
614a20a0 2604 continue;
32874aea 2605 } else {
51470298 2606 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2607 logevent("Received TIS challenge");
51470298 2608 if (challengelen > sizeof(s->prompt) - 1)
2609 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2610 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2611 /* Prompt heuristic comes from OpenSSH */
51470298 2612 strncpy(s->prompt + challengelen,
2613 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2614 "": "\r\nResponse: ",
51470298 2615 (sizeof s->prompt) - challengelen);
2616 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2617 }
2618 }
86916870 2619 if (ssh->cfg.try_tis_auth &&
51470298 2620 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2621 !s->ccard_auth_refused) {
2622 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2623 logevent("Requested CryptoCard authentication");
51470298 2624 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2625 crWaitUntil(ispkt);
51470298 2626 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2627 logevent("CryptoCard authentication declined");
51470298 2628 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2629 s->ccard_auth_refused = 1;
614a20a0 2630 continue;
32874aea 2631 } else {
51470298 2632 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2633 logevent("Received CryptoCard challenge");
51470298 2634 if (challengelen > sizeof(s->prompt) - 1)
2635 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2636 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2637 strncpy(s->prompt + challengelen,
2638 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2639 "" : "\r\nResponse: ",
51470298 2640 sizeof(s->prompt) - challengelen);
2641 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2642 }
2643 }
51470298 2644 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2645 sprintf(s->prompt, "%.90s@%.90s's password: ",
2646 s->username, ssh->savedhost);
32874aea 2647 }
51470298 2648 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2649 char *comment = NULL;
231ee168 2650 int type;
2651 char msgbuf[256];
32874aea 2652 if (flags & FLAG_VERBOSE)
51470298 2653 c_write_str(ssh, "Trying public key authentication.\r\n");
86916870 2654 logeventf(ssh, "Trying public key \"%s\"", ssh->cfg.keyfile);
9a30e26b 2655 type = key_type(&ssh->cfg.keyfile);
231ee168 2656 if (type != SSH_KEYTYPE_SSH1) {
2657 sprintf(msgbuf, "Key is of wrong type (%s)",
2658 key_type_to_str(type));
2659 logevent(msgbuf);
51470298 2660 c_write_str(ssh, msgbuf);
2661 c_write_str(ssh, "\r\n");
2662 s->tried_publickey = 1;
231ee168 2663 continue;
2664 }
9a30e26b 2665 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 2666 if (flags & FLAG_VERBOSE)
51470298 2667 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2668 goto tryauth;
2669 }
51470298 2670 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2671 sfree(comment);
2672 }
a52f067e 2673
614a20a0 2674 /*
2675 * Show password prompt, having first obtained it via a TIS
2676 * or CryptoCard exchange if we're doing TIS or CryptoCard
2677 * authentication.
2678 */
fa17a66e 2679 if (ssh_get_line) {
51470298 2680 if (!ssh_get_line(s->prompt, s->password,
2681 sizeof(s->password), TRUE)) {
32874aea 2682 /*
2683 * get_line failed to get a password (for example
2684 * because one was supplied on the command line
2685 * which has already failed to work). Terminate.
2686 */
51470298 2687 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2688 PKT_STR, "No more passwords available to try",
2689 PKT_END);
247308b5 2690 logevent("Unable to authenticate");
a8327734 2691 connection_fatal(ssh->frontend, "Unable to authenticate");
51470298 2692 ssh->state = SSH_STATE_CLOSED;
32874aea 2693 crReturn(1);
2694 }
fb09bf1c 2695 } else {
614a20a0 2696 /* Prompt may have come from server. We've munged it a bit, so
2697 * we know it to be zero-terminated at least once. */
51470298 2698 int ret; /* need not be saved over crReturn */
2699 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2700 s->pos = 0;
0405e71f 2701
51470298 2702 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2703 do {
32874aea 2704 crWaitUntil(!ispkt);
51470298 2705 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2706 } while (ret == 0);
2707 if (ret < 0)
2708 cleanup_exit(0);
51470298 2709 c_write_str(ssh, "\r\n");
32874aea 2710 }
2711
2712 tryauth:
51470298 2713 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2714 /*
2715 * Try public key authentication with the specified
2716 * key file.
2717 */
51470298 2718 s->tried_publickey = 1;
2719
2720 {
9a30e26b 2721 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
51470298 2722 if (ret == 0) {
2723 c_write_str(ssh, "Couldn't load private key from ");
9a30e26b 2724 c_write_str(ssh, filename_to_str(ssh->cfg.keyfile));
51470298 2725 c_write_str(ssh, ".\r\n");
2726 continue; /* go and try password */
2727 }
2728 if (ret == -1) {
2729 c_write_str(ssh, "Wrong passphrase.\r\n");
2730 s->tried_publickey = 0;
2731 continue; /* try again */
2732 }
32874aea 2733 }
2734
2735 /*
2736 * Send a public key attempt.
2737 */
51470298 2738 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2739 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2740
2741 crWaitUntil(ispkt);
51470298 2742 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2743 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2744 continue; /* go and try password */
2745 }
51470298 2746 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
a8327734 2747 bombout((ssh,"Bizarre response to offer of public key"));
32874aea 2748 crReturn(0);
2749 }
32874aea 2750
51470298 2751 {
2752 int i;
2753 unsigned char buffer[32];
2754 Bignum challenge, response;
2755
2756 ssh1_read_bignum(ssh->pktin.body, &challenge);
2757 response = rsadecrypt(challenge, &s->key);
2758 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2759
51470298 2760 for (i = 0; i < 32; i++) {
2761 buffer[i] = bignum_byte(response, 31 - i);
2762 }
2763
2764 MD5Init(&md5c);
2765 MD5Update(&md5c, buffer, 32);
2766 MD5Update(&md5c, s->session_id, 16);
2767 MD5Final(buffer, &md5c);
32874aea 2768
51470298 2769 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2770 PKT_DATA, buffer, 16, PKT_END);
2771
2772 freebn(challenge);
2773 freebn(response);
2774 }
32874aea 2775
2776 crWaitUntil(ispkt);
51470298 2777 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2778 if (flags & FLAG_VERBOSE)
51470298 2779 c_write_str(ssh, "Failed to authenticate with"
2780 " our public key.\r\n");
32874aea 2781 continue; /* go and try password */
51470298 2782 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2783 bombout((ssh,"Bizarre response to RSA authentication response"));
32874aea 2784 crReturn(0);
2785 }
2786
2787 break; /* we're through! */
2788 } else {
51470298 2789 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2790 /*
2791 * Defence against traffic analysis: we send a
2792 * whole bunch of packets containing strings of
2793 * different lengths. One of these strings is the
2794 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2795 * The others are all random data in
2796 * SSH1_MSG_IGNORE packets. This way a passive
2797 * listener can't tell which is the password, and
2798 * hence can't deduce the password length.
2799 *
2800 * Anybody with a password length greater than 16
2801 * bytes is going to have enough entropy in their
2802 * password that a listener won't find it _that_
2803 * much help to know how long it is. So what we'll
2804 * do is:
2805 *
2806 * - if password length < 16, we send 15 packets
2807 * containing string lengths 1 through 15
2808 *
2809 * - otherwise, we let N be the nearest multiple
2810 * of 8 below the password length, and send 8
2811 * packets containing string lengths N through
2812 * N+7. This won't obscure the order of
2813 * magnitude of the password length, but it will
2814 * introduce a bit of extra uncertainty.
2815 *
2816 * A few servers (the old 1.2.18 through 1.2.22)
2817 * can't deal with SSH1_MSG_IGNORE. For these
2818 * servers, we need an alternative defence. We make
2819 * use of the fact that the password is interpreted
2820 * as a C string: so we can append a NUL, then some
2821 * random data.
bd358db1 2822 *
2823 * One server (a Cisco one) can deal with neither
2824 * SSH1_MSG_IGNORE _nor_ a padded password string.
2825 * For this server we are left with no defences
2826 * against password length sniffing.
32874aea 2827 */
51470298 2828 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2829 /*
2830 * The server can deal with SSH1_MSG_IGNORE, so
2831 * we can use the primary defence.
2832 */
32874aea 2833 int bottom, top, pwlen, i;
2834 char *randomstr;
2835
51470298 2836 pwlen = strlen(s->password);
32874aea 2837 if (pwlen < 16) {
2838 bottom = 0; /* zero length passwords are OK! :-) */
2839 top = 15;
2840 } else {
2841 bottom = pwlen & ~7;
2842 top = bottom + 7;
2843 }
2844
2845 assert(pwlen >= bottom && pwlen <= top);
2846
2847 randomstr = smalloc(top + 1);
2848
2849 for (i = bottom; i <= top; i++) {
2850 if (i == pwlen)
51470298 2851 defer_packet(ssh, s->pwpkt_type,
2852 PKT_STR, s->password, PKT_END);
32874aea 2853 else {
2854 for (j = 0; j < i; j++) {
2855 do {
2856 randomstr[j] = random_byte();
2857 } while (randomstr[j] == '\0');
2858 }
2859 randomstr[i] = '\0';
51470298 2860 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 2861 PKT_STR, randomstr, PKT_END);
2862 }
2863 }
bd358db1 2864 logevent("Sending password with camouflage packets");
51470298 2865 ssh_pkt_defersend(ssh);
bd358db1 2866 }
51470298 2867 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2868 /*
2869 * The server can't deal with SSH1_MSG_IGNORE
2870 * but can deal with padded passwords, so we
2871 * can use the secondary defence.
2872 */
bd358db1 2873 char string[64];
51470298 2874 char *ss;
bd358db1 2875 int len;
2876
51470298 2877 len = strlen(s->password);
bd358db1 2878 if (len < sizeof(string)) {
51470298 2879 ss = string;
2880 strcpy(string, s->password);
bd358db1 2881 len++; /* cover the zero byte */
2882 while (len < sizeof(string)) {
2883 string[len++] = (char) random_byte();
2884 }
2885 } else {
51470298 2886 ss = s->password;
bd358db1 2887 }
2888 logevent("Sending length-padded password");
51470298 2889 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2890 PKT_DATA, ss, len, PKT_END);
bd358db1 2891 } else {
2892 /*
2893 * The server has _both_
2894 * BUG_CHOKES_ON_SSH1_IGNORE and
2895 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2896 * therefore nothing we can do.
2897 */
2898 int len;
51470298 2899 len = strlen(s->password);
bd358db1 2900 logevent("Sending unpadded password");
51470298 2901 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2902 PKT_DATA, s->password, len, PKT_END);
32874aea 2903 }
2904 } else {
51470298 2905 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 2906 }
2907 }
c5e9c988 2908 logevent("Sent password");
51470298 2909 memset(s->password, 0, strlen(s->password));
fb09bf1c 2910 crWaitUntil(ispkt);
51470298 2911 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2912 if (flags & FLAG_VERBOSE)
51470298 2913 c_write_str(ssh, "Access denied\r\n");
c5e9c988 2914 logevent("Authentication refused");
51470298 2915 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2916 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
32874aea 2917 crReturn(0);
374330e2 2918 }
2919 }
2920
c5e9c988 2921 logevent("Authentication successful");
2922
fb09bf1c 2923 crFinish(1);
2924}
2925
32874aea 2926void sshfwd_close(struct ssh_channel *c)
2927{
51470298 2928 Ssh ssh = c->ssh;
2929
80e48603 2930 if (c && !c->closes) {
4ed34d25 2931 /*
2932 * If the channel's remoteid is -1, we have sent
2933 * CHANNEL_OPEN for this channel, but it hasn't even been
2934 * acknowledged by the server. So we must set a close flag
2935 * on it now, and then when the server acks the channel
2936 * open, we can close it then.
2937 */
36cac739 2938 if (((int)c->remoteid) != -1) {
51470298 2939 if (ssh->version == 1) {
2940 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 2941 PKT_END);
2942 } else {
51470298 2943 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2944 ssh2_pkt_adduint32(ssh, c->remoteid);
2945 ssh2_pkt_send(ssh);
4ed34d25 2946 }
32874aea 2947 }
0357890f 2948 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2949 if (c->type == CHAN_X11) {
2950 c->u.x11.s = NULL;
d74d141c 2951 logevent("Forwarded X11 connection terminated");
4ed34d25 2952 } else if (c->type == CHAN_SOCKDATA ||
2953 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2954 c->u.pfd.s = NULL;
2955 logevent("Forwarded port closed");
32874aea 2956 }
2957 }
2958}
2959
5471d09a 2960int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2961{
51470298 2962 Ssh ssh = c->ssh;
2963
2964 if (ssh->version == 1) {
2965 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 2966 PKT_INT, c->remoteid,
2967 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2968 /*
2969 * In SSH1 we can return 0 here - implying that forwarded
2970 * connections are never individually throttled - because
2971 * the only circumstance that can cause throttling will be
2972 * the whole SSH connection backing up, in which case
2973 * _everything_ will be throttled as a whole.
2974 */
2975 return 0;
783415f8 2976 } else {
32874aea 2977 ssh2_add_channel_data(c, buf, len);
5471d09a 2978 return ssh2_try_send(c);
2979 }
2980}
2981
2982void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2983{
51470298 2984 Ssh ssh = c->ssh;
2985
2986 if (ssh->version == 1) {
5471d09a 2987 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2988 c->v.v1.throttling = 0;
51470298 2989 ssh1_throttle(ssh, -1);
5471d09a 2990 }
2991 } else {
2992 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2993 }
9c964e85 2994}
2995
51470298 2996static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 2997{
51470298 2998 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 2999
3000 random_init();
3001
51470298 3002 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3003 crReturnV;
85ee8208 3004 }
51470298 3005 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3006 crReturnV;
fb09bf1c 3007
86916870 3008 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3009 logevent("Requesting agent forwarding");
51470298 3010 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3011 do {
3012 crReturnV;
3013 } while (!ispkt);
51470298 3014 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3015 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3016 bombout((ssh,"Protocol confusion"));
32874aea 3017 crReturnV;
51470298 3018 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3019 logevent("Agent forwarding refused");
3020 } else {
3021 logevent("Agent forwarding enabled");
51470298 3022 ssh->agentfwd_enabled = TRUE;
db7d555c 3023 }
dacbd0e8 3024 }
3025
86916870 3026 if (ssh->cfg.x11_forward) {
32874aea 3027 char proto[20], data[64];
3028 logevent("Requesting X11 forwarding");
302121de 3029 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3030 data, sizeof(data), ssh->cfg.x11_auth);
3031 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3032 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3033 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3034 PKT_STR, proto, PKT_STR, data,
86916870 3035 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3036 PKT_END);
32874aea 3037 } else {
51470298 3038 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3039 PKT_STR, proto, PKT_STR, data, PKT_END);
3040 }
3041 do {
3042 crReturnV;
3043 } while (!ispkt);
51470298 3044 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3045 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3046 bombout((ssh,"Protocol confusion"));
32874aea 3047 crReturnV;
51470298 3048 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3049 logevent("X11 forwarding refused");
3050 } else {
3051 logevent("X11 forwarding enabled");
51470298 3052 ssh->X11_fwd_enabled = TRUE;
9c964e85 3053 }
3054 }
3055
d74d141c 3056 {
9bf696b1 3057 char type;
d74d141c 3058 int n;
a4fc0d74 3059 int sport,dport,sserv,dserv;
6ee9b735 3060 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3061
51470298 3062 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3063 /* Add port forwardings. */
86916870 3064 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3065 while (*ssh->portfwd_strptr) {
3066 type = *ssh->portfwd_strptr++;
6ee9b735 3067 saddr[0] = '\0';
d74d141c 3068 n = 0;
6ee9b735 3069 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3070 if (*ssh->portfwd_strptr == ':') {
3071 /*
3072 * We've seen a colon in the middle of the
3073 * source port number. This means that
3074 * everything we've seen until now is the
3075 * source _address_, so we'll move it into
3076 * saddr and start sports from the beginning
3077 * again.
3078 */
3079 ssh->portfwd_strptr++;
3080 sports[n] = '\0';
3081 strcpy(saddr, sports);
3082 n = 0;
3083 }
3084 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3085 }
d74d141c 3086 sports[n] = 0;
51470298 3087 if (*ssh->portfwd_strptr == '\t')
3088 ssh->portfwd_strptr++;
d74d141c 3089 n = 0;
6ee9b735 3090 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3091 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3092 }
d74d141c 3093 host[n] = 0;
51470298 3094 if (*ssh->portfwd_strptr == ':')
3095 ssh->portfwd_strptr++;
d74d141c 3096 n = 0;
6ee9b735 3097 while (*ssh->portfwd_strptr) {
3098 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3099 }
d74d141c 3100 dports[n] = 0;
51470298 3101 ssh->portfwd_strptr++;
d74d141c 3102 dport = atoi(dports);
a4fc0d74 3103 dserv = 0;
3104 if (dport == 0) {
3105 dserv = 1;
68a49acb 3106 dport = net_service_lookup(dports);
3107 if (!dport) {
57356d63 3108 logeventf(ssh, "Service lookup failed for"
3109 " destination port \"%s\"", dports);
a4fc0d74 3110 }
3111 }
d74d141c 3112 sport = atoi(sports);
a4fc0d74 3113 sserv = 0;
3114 if (sport == 0) {
3115 sserv = 1;
68a49acb 3116 sport = net_service_lookup(sports);
3117 if (!sport) {
57356d63 3118 logeventf(ssh, "Service lookup failed for source"
3119 " port \"%s\"", sports);
a4fc0d74 3120 }
3121 }
d74d141c 3122 if (sport && dport) {
3123 if (type == 'L') {
6ee9b735 3124 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 3125 sport, ssh, &ssh->cfg);
6ee9b735 3126 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3127 " forwarding to %s:%.*s%.*s%d%.*s",
3128 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3129 (int)(*saddr?1:0), ":",
57356d63 3130 (int)(sserv ? strlen(sports) : 0), sports,
3131 sserv, "(", sport, sserv, ")",
3132 host,
3133 (int)(dserv ? strlen(dports) : 0), dports,
3134 dserv, "(", dport, dserv, ")");
d74d141c 3135 } else {
3136 struct ssh_rportfwd *pf;
3137 pf = smalloc(sizeof(*pf));
bc240b21 3138 strcpy(pf->dhost, host);
3139 pf->dport = dport;
6ee9b735 3140 if (saddr) {
3141 logeventf(ssh,
3142 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3143 saddr, sport);
3144 }
51470298 3145 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3146 logeventf(ssh,
3147 "Duplicate remote port forwarding to %s:%d",
3148 host, dport);
bc240b21 3149 sfree(pf);
d74d141c 3150 } else {
57356d63 3151 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3152 " forward to %s:%.*s%.*s%d%.*s",
3153 (int)(sserv ? strlen(sports) : 0), sports,
3154 sserv, "(", sport, sserv, ")",
3155 host,
3156 (int)(dserv ? strlen(dports) : 0), dports,
3157 dserv, "(", dport, dserv, ")");
51470298 3158 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3159 PKT_INT, sport,
3160 PKT_STR, host,
3161 PKT_INT, dport,
3162 PKT_END);
9bf696b1 3163 do {
3164 crReturnV;
3165 } while (!ispkt);
51470298 3166 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3167 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3168 bombout((ssh,"Protocol confusion"));
9bf696b1 3169 crReturnV;
51470298 3170 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3171 c_write_str(ssh, "Server refused port"
3172 " forwarding\r\n");
9bf696b1 3173 }
3174 logevent("Remote port forwarding enabled");
d74d141c 3175 }
3176 }
3177 }
3178 }
3179 }
3180
86916870 3181 if (!ssh->cfg.nopty) {
51470298 3182 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3183 PKT_STR, ssh->cfg.termtype,
51470298 3184 PKT_INT, ssh->term_height,
3185 PKT_INT, ssh->term_width,
32874aea 3186 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3187 ssh->state = SSH_STATE_INTERMED;
32874aea 3188 do {
3189 crReturnV;
3190 } while (!ispkt);
51470298 3191 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3192 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3193 bombout((ssh,"Protocol confusion"));
32874aea 3194 crReturnV;
51470298 3195 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3196 c_write_str(ssh, "Server refused to allocate pty\r\n");
3197 ssh->editing = ssh->echoing = 1;
32874aea 3198 }
c5e9c988 3199 logevent("Allocated pty");
0965bee0 3200 } else {
51470298 3201 ssh->editing = ssh->echoing = 1;
374330e2 3202 }
3203
86916870 3204 if (ssh->cfg.compression) {
51470298 3205 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3206 do {
3207 crReturnV;
3208 } while (!ispkt);
51470298 3209 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3210 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3211 bombout((ssh,"Protocol confusion"));
32874aea 3212 crReturnV;
51470298 3213 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3214 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3215 }
4ba9b64b 3216 logevent("Started compression");
51470298 3217 ssh->v1_compressing = TRUE;
5366aed8 3218 ssh->cs_comp_ctx = zlib_compress_init();
3219 logevent("Initialised zlib (RFC1950) compression");
3220 ssh->sc_comp_ctx = zlib_decompress_init();
3221 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3222 }
3223
fd5e5847 3224 /*
3225 * Start the shell or command.
3226 *
3227 * Special case: if the first-choice command is an SSH2
3228 * subsystem (hence not usable here) and the second choice
3229 * exists, we fall straight back to that.
3230 */
3231 {
86916870 3232 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3233
86916870 3234 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3235 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3236 ssh->fallback_cmd = TRUE;
fd5e5847 3237 }
3238 if (*cmd)
51470298 3239 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3240 else
51470298 3241 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3242 logevent("Started session");
3243 }
374330e2 3244
51470298 3245 ssh->state = SSH_STATE_SESSION;
3246 if (ssh->size_needed)
3247 ssh_size(ssh, ssh->term_width, ssh->term_height);
3248 if (ssh->eof_needed)
3249 ssh_special(ssh, TS_EOF);
374330e2 3250
b9d7bcad 3251 if (ssh->ldisc)
3252 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3253 ssh->send_ok = 1;
3254 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3255 while (1) {
3256 crReturnV;
3257 if (ispkt) {
51470298 3258 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3259 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3260 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3261 int bufsize =
51470298 3262 from_backend(ssh->frontend,
3263 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
d8baa528 3264 (char *)(ssh->pktin.body) + 4, len);
51470298 3265 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3266 ssh->v1_stdout_throttling = 1;
3267 ssh1_throttle(ssh, +1);
5471d09a 3268 }
51470298 3269 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3270 ssh->state = SSH_STATE_CLOSED;
c5e9c988 3271 logevent("Received disconnect request");
32874aea 3272 crReturnV;
51470298 3273 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3274 /* Remote side is trying to open a channel to talk to our
3275 * X-Server. Give them back a local channel number. */
3276 struct ssh_channel *c;
9c964e85 3277
3278 logevent("Received X11 connect request");
3279 /* Refuse if X11 forwarding is disabled. */
51470298 3280 if (!ssh->X11_fwd_enabled) {
3281 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3282 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3283 logevent("Rejected X11 connect request");
3284 } else {
9c964e85 3285 c = smalloc(sizeof(struct ssh_channel));
51470298 3286 c->ssh = ssh;
9c964e85 3287
86916870 3288 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3289 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
32874aea 3290 logevent("opening X11 forward connection failed");
3291 sfree(c);
51470298 3292 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3293 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3294 PKT_END);
9c964e85 3295 } else {
32874aea 3296 logevent
3297 ("opening X11 forward connection succeeded");
51470298 3298 c->remoteid = GET_32BIT(ssh->pktin.body);
3299 c->localid = alloc_channel_id(ssh);
32874aea 3300 c->closes = 0;
5471d09a 3301 c->v.v1.throttling = 0;
32874aea 3302 c->type = CHAN_X11; /* identify channel type */
51470298 3303 add234(ssh->channels, c);
3304 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3305 PKT_INT, c->remoteid, PKT_INT,
3306 c->localid, PKT_END);
3307 logevent("Opened X11 forward channel");
9c964e85 3308 }
3309 }
51470298 3310 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3311 /* Remote side is trying to open a channel to talk to our
3312 * agent. Give them back a local channel number. */
3313 struct ssh_channel *c;
db7d555c 3314
3315 /* Refuse if agent forwarding is disabled. */
51470298 3316 if (!ssh->agentfwd_enabled) {
3317 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3318 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3319 } else {
dcbde236 3320 c = smalloc(sizeof(struct ssh_channel));
51470298 3321 c->ssh = ssh;
3322 c->remoteid = GET_32BIT(ssh->pktin.body);
3323 c->localid = alloc_channel_id(ssh);
db7d555c 3324 c->closes = 0;
5471d09a 3325 c->v.v1.throttling = 0;
32874aea 3326 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3327 c->u.a.lensofar = 0;
51470298 3328 add234(ssh->channels, c);
3329 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3330 PKT_INT, c->remoteid, PKT_INT, c->localid,
3331 PKT_END);
3332 }
51470298 3333 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3334 /* Remote side is trying to open a channel to talk to a
3335 * forwarded port. Give them back a local channel number. */
3336 struct ssh_channel *c;
3337 struct ssh_rportfwd pf;
3338 int hostsize, port;
3339 char host[256], buf[1024];
3340 char *p, *h, *e;
3341 c = smalloc(sizeof(struct ssh_channel));
51470298 3342 c->ssh = ssh;
d74d141c 3343
51470298 3344 hostsize = GET_32BIT(ssh->pktin.body+4);
d8baa528 3345 for (h = host, p = (char *)(ssh->pktin.body+8);
3346 hostsize != 0; hostsize--) {
d74d141c 3347 if (h+1 < host+sizeof(host))
3348 *h++ = *p;
95bc8819 3349 p++;
d74d141c 3350 }
3351 *h = 0;
3352 port = GET_32BIT(p);
3353
bc240b21 3354 strcpy(pf.dhost, host);
3355 pf.dport = port;
d74d141c 3356
51470298 3357 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3358 sprintf(buf, "Rejected remote port open request for %s:%d",
3359 host, port);
3360 logevent(buf);
51470298 3361 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3362 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3363 } else {
3364 sprintf(buf, "Received remote port open request for %s:%d",
3365 host, port);
3366 logevent(buf);
e8fa8f62 3367 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
d74d141c 3368 if (e != NULL) {
3369 char buf[256];
3370 sprintf(buf, "Port open failed: %s", e);
3371 logevent(buf);
3372 sfree(c);
51470298 3373 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3374 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3375 PKT_END);
3376 } else {
51470298 3377 c->remoteid = GET_32BIT(ssh->pktin.body);
3378 c->localid = alloc_channel_id(ssh);
d74d141c 3379 c->closes = 0;
5471d09a 3380 c->v.v1.throttling = 0;
d74d141c 3381 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3382 add234(ssh->channels, c);
3383 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3384 PKT_INT, c->remoteid, PKT_INT,
3385 c->localid, PKT_END);
3386 logevent("Forwarded port opened successfully");
3387 }
3388 }
3389
51470298 3390 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3391 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3392 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3393 struct ssh_channel *c;
3394
51470298 3395 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3396 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3397 c->remoteid = localid;
3398 c->type = CHAN_SOCKDATA;
7781f316 3399 c->v.v1.throttling = 0;
bc240b21 3400 pfd_confirm(c->u.pfd.s);
3401 }
d74d141c 3402
4ed34d25 3403 if (c && c->closes) {
3404 /*
3405 * We have a pending close on this channel,
3406 * which we decided on before the server acked
3407 * the channel open. So now we know the
3408 * remoteid, we can close it again.
3409 */
51470298 3410 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3411 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3412 }
3413
51470298 3414 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3415 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
724cface 3416 struct ssh_channel *c;
3417
51470298 3418 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3419 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3420 logevent("Forwarded connection refused by server");
3421 pfd_close(c->u.pfd.s);
51470298 3422 del234(ssh->channels, c);
724cface 3423 sfree(c);
3424 }
3425
51470298 3426 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3427 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3428 /* Remote side closes a channel. */
51470298 3429 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3430 struct ssh_channel *c;
51470298 3431 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3432 if (c && ((int)c->remoteid) != -1) {
32874aea 3433 int closetype;
3434 closetype =
51470298 3435 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3436
783415f8 3437 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3438 logevent("Forwarded X11 connection terminated");
9c964e85 3439 assert(c->u.x11.s != NULL);
3440 x11_close(c->u.x11.s);
3441 c->u.x11.s = NULL;
3442 }
d74d141c 3443 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3444 logevent("Forwarded port closed");
3445 assert(c->u.pfd.s != NULL);
3446 pfd_close(c->u.pfd.s);
3447 c->u.pfd.s = NULL;
3448 }
0357890f 3449
3450 c->closes |= (closetype << 2); /* seen this message */
3451 if (!(c->closes & closetype)) {
51470298 3452 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3453 PKT_END);
3454 c->closes |= closetype; /* sent it too */
3455 }
3456
3457 if (c->closes == 15) {
51470298 3458 del234(ssh->channels, c);
32874aea 3459 sfree(c);
3460 }
d0d844c1 3461 } else {
a8327734 3462 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3463 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3464 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3465 i));
32874aea 3466 }
51470298 3467 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3468 /* Data sent down one of our channels. */
51470298 3469 int i = GET_32BIT(ssh->pktin.body);
3470 int len = GET_32BIT(ssh->pktin.body + 4);
3471 unsigned char *p = ssh->pktin.body + 8;
32874aea 3472 struct ssh_channel *c;
51470298 3473 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3474 if (c) {
5471d09a 3475 int bufsize;
32874aea 3476 switch (c->type) {
3477 case CHAN_X11:
d8baa528 3478 bufsize = x11_send(c->u.x11.s, (char *)p, len);
9c964e85 3479 break;
d74d141c 3480 case CHAN_SOCKDATA:
d8baa528 3481 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
bc240b21 3482 break;
32874aea 3483 case CHAN_AGENT:
3484 /* Data for an agent message. Buffer it. */
3485 while (len > 0) {
3486 if (c->u.a.lensofar < 4) {
3487 int l = min(4 - c->u.a.lensofar, len);
3488 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3489 l);
3490 p += l;
3491 len -= l;
3492 c->u.a.lensofar += l;
3493 }
3494 if (c->u.a.lensofar == 4) {
3495 c->u.a.totallen =
3496 4 + GET_32BIT(c->u.a.msglen);
3497 c->u.a.message = smalloc(c->u.a.totallen);
3498 memcpy(c->u.a.message, c->u.a.msglen, 4);
3499 }
3500 if (c->u.a.lensofar >= 4 && len > 0) {
3501 int l =
3502 min(c->u.a.totallen - c->u.a.lensofar,
3503 len);
3504 memcpy(c->u.a.message + c->u.a.lensofar, p,
3505 l);
3506 p += l;
3507 len -= l;
3508 c->u.a.lensofar += l;
3509 }
3510 if (c->u.a.lensofar == c->u.a.totallen) {
3511 void *reply, *sentreply;
3512 int replylen;
3513 agent_query(c->u.a.message,
3514 c->u.a.totallen, &reply,
3515 &replylen);
3516 if (reply)
3517 sentreply = reply;
3518 else {
3519 /* Fake SSH_AGENT_FAILURE. */
3520 sentreply = "\0\0\0\1\5";
3521 replylen = 5;
3522 }
51470298 3523 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3524 PKT_INT, c->remoteid,
3525 PKT_INT, replylen,
3526 PKT_DATA, sentreply, replylen,
3527 PKT_END);
3528 if (reply)
3529 sfree(reply);
3530 sfree(c->u.a.message);
3531 c->u.a.lensofar = 0;
3532 }
3533 }
5471d09a 3534 bufsize = 0; /* agent channels never back up */
32874aea 3535 break;
3536 }
90347b95 3537 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3538 c->v.v1.throttling = 1;
51470298 3539 ssh1_throttle(ssh, +1);
5471d09a 3540 }
32874aea 3541 }
51470298 3542 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3543 /* may be from EXEC_SHELL on some servers */
51470298 3544 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3545 /* may be from EXEC_SHELL on some servers
374330e2 3546 * if no pty is available or in other odd cases. Ignore */
51470298 3547 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3548 char buf[100];
51470298 3549 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3550 sprintf(buf, "Server sent command exit status %d",
51470298 3551 ssh->exitcode);
d8d6c7e5 3552 logevent(buf);
51470298 3553 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3554 /*
3555 * In case `helpful' firewalls or proxies tack
3556 * extra human-readable text on the end of the
3557 * session which we might mistake for another
3558 * encrypted packet, we close the session once
3559 * we've sent EXIT_CONFIRMATION.
3560 */
51470298 3561 ssh->state = SSH_STATE_CLOSED;
4252c9cc 3562 crReturnV;
374330e2 3563 } else {
a8327734 3564 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
32874aea 3565 crReturnV;
374330e2 3566 }
3567 } else {
8df7a775 3568 while (inlen > 0) {
3569 int len = min(inlen, 512);
51470298 3570 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3571 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3572 in += len;
3573 inlen -= len;
3574 }
374330e2 3575 }
3576 }
3577
3578 crFinishV;
3579}
3580
3581/*
e5574168 3582 * Utility routine for decoding comma-separated strings in KEXINIT.
3583 */
32874aea 3584static int in_commasep_string(char *needle, char *haystack, int haylen)
3585{
57356d63 3586 int needlen;
3587 if (!needle || !haystack) /* protect against null pointers */
3588 return 0;
3589 needlen = strlen(needle);
e5574168 3590 while (1) {
32874aea 3591 /*
3592 * Is it at the start of the string?
3593 */
3594 if (haylen >= needlen && /* haystack is long enough */
3595 !memcmp(needle, haystack, needlen) && /* initial match */
3596 (haylen == needlen || haystack[needlen] == ',')
3597 /* either , or EOS follows */
3598 )
3599 return 1;
3600 /*
3601 * If not, search for the next comma and resume after that.
3602 * If no comma found, terminate.
3603 */
3604 while (haylen > 0 && *haystack != ',')
3605 haylen--, haystack++;
3606 if (haylen == 0)
3607 return 0;
3608 haylen--, haystack++; /* skip over comma itself */
e5574168 3609 }
3610}
3611
3612/*
d39f364a 3613 * SSH2 key creation method.
3614 */
d8baa528 3615static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3616 unsigned char *sessid, char chr,
3617 unsigned char *keyspace)
32874aea 3618{
d39f364a 3619 SHA_State s;
3620 /* First 20 bytes. */
3621 SHA_Init(&s);
51470298 3622 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3623 sha_mpint(&s, K);
d39f364a 3624 SHA_Bytes(&s, H, 20);
3625 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3626 SHA_Bytes(&s, sessid, 20);
d39f364a 3627 SHA_Final(&s, keyspace);
3628 /* Next 20 bytes. */
3629 SHA_Init(&s);
51470298 3630 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3631 sha_mpint(&s, K);
d39f364a 3632 SHA_Bytes(&s, H, 20);
3633 SHA_Bytes(&s, keyspace, 20);
32874aea 3634 SHA_Final(&s, keyspace + 20);
d39f364a 3635}
3636
3637/*
7cca0d81 3638 * Handle the SSH2 transport layer.
e5574168 3639 */
51470298 3640static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3641{
51470298 3642 struct do_ssh2_transport_state {
3643 int nbits, pbits, warn;
3644 Bignum p, g, e, f, K;
3645 int kex_init_value, kex_reply_value;
3646 const struct ssh_mac **maclist;
3647 int nmacs;
3648 const struct ssh2_cipher *cscipher_tobe;
3649 const struct ssh2_cipher *sccipher_tobe;
3650 const struct ssh_mac *csmac_tobe;
3651 const struct ssh_mac *scmac_tobe;
3652 const struct ssh_compress *cscomp_tobe;
3653 const struct ssh_compress *sccomp_tobe;
3654 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3655 int hostkeylen, siglen;
3656 void *hkey; /* actual host key */
3657 unsigned char exchange_hash[20];
3658 int n_preferred_ciphers;
3659 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3660 const struct ssh_compress *preferred_comp;
3661 int first_kex;
3662 };
3663 crState(do_ssh2_transport_state);
3664
3665 crBegin(ssh->do_ssh2_transport_crstate);
3666
3667 s->cscipher_tobe = s->sccipher_tobe = NULL;
3668 s->csmac_tobe = s->scmac_tobe = NULL;
3669 s->cscomp_tobe = s->sccomp_tobe = NULL;
3670
7cca0d81 3671 random_init();
51470298 3672 s->first_kex = 1;
e5574168 3673
51470298 3674 {
3675 int i;
3676 /*
3677 * Set up the preferred ciphers. (NULL => warn below here)
3678 */
3679 s->n_preferred_ciphers = 0;
3680 for (i = 0; i < CIPHER_MAX; i++) {
86916870 3681 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 3682 case CIPHER_BLOWFISH:
3683 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3684 break;
3685 case CIPHER_DES:
86916870 3686 if (ssh->cfg.ssh2_des_cbc) {
51470298 3687 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3688 }
3689 break;
3690 case CIPHER_3DES:
3691 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3692 break;
3693 case CIPHER_AES:
3694 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3695 break;
3696 case CIPHER_WARN:
3697 /* Flag for later. Don't bother if it's the last in
3698 * the list. */
3699 if (i < CIPHER_MAX - 1) {
3700 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3701 }
3702 break;
ca20bfcf 3703 }
ca20bfcf 3704 }
5e8358ad 3705 }
ca20bfcf 3706
3707 /*
3708 * Set up preferred compression.
3709 */
86916870 3710 if (ssh->cfg.compression)
51470298 3711 s->preferred_comp = &ssh_zlib;
4ba9b64b 3712 else
51470298 3713 s->preferred_comp = &ssh_comp_none;
5e8358ad 3714
7591b9ff 3715 /*
3716 * Be prepared to work around the buggy MAC problem.
3717 */
51470298 3718 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3719 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3720 else
51470298 3721 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3722
32874aea 3723 begin_key_exchange:
51470298 3724 {
3725 int i, j, cipherstr_started;
3726
3727 /*
3728 * Construct and send our key exchange packet.
3729 */
3730 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3731 for (i = 0; i < 16; i++)
3732 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3733 /* List key exchange algorithms. */
3734 ssh2_pkt_addstring_start(ssh);
3735 for (i = 0; i < lenof(kex_algs); i++) {
3736 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3737 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3738 continue;
3739 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3740 if (i < lenof(kex_algs) - 1)
3741 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3742 }
51470298 3743 /* List server host key algorithms. */
3744 ssh2_pkt_addstring_start(ssh);
3745 for (i = 0; i < lenof(hostkey_algs); i++) {
3746 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3747 if (i < lenof(hostkey_algs) - 1)
3748 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3749 }
51470298 3750 /* List client->server encryption algorithms. */
3751 ssh2_pkt_addstring_start(ssh);
3752 cipherstr_started = 0;
3753 for (i = 0; i < s->n_preferred_ciphers; i++) {
3754 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3755 if (!c) continue; /* warning flag */
3756 for (j = 0; j < c->nciphers; j++) {
3757 if (cipherstr_started)
3758 ssh2_pkt_addstring_str(ssh, ",");
3759 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3760 cipherstr_started = 1;
3761 }
3762 }
3763 /* List server->client encryption algorithms. */
3764 ssh2_pkt_addstring_start(ssh);
3765 cipherstr_started = 0;
3766 for (i = 0; i < s->n_preferred_ciphers; i++) {
3767 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3768 if (!c) continue; /* warning flag */
3769 for (j = 0; j < c->nciphers; j++) {
3770 if (cipherstr_started)
3771 ssh2_pkt_addstring_str(ssh, ",");
3772 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3773 cipherstr_started = 1;
3774 }
3775 }
3776 /* List client->server MAC algorithms. */
3777 ssh2_pkt_addstring_start(ssh);
3778 for (i = 0; i < s->nmacs; i++) {
3779 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3780 if (i < s->nmacs - 1)
3781 ssh2_pkt_addstring_str(ssh, ",");
3782 }
3783 /* List server->client MAC algorithms. */
3784 ssh2_pkt_addstring_start(ssh);
3785 for (i = 0; i < s->nmacs; i++) {
3786 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3787 if (i < s->nmacs - 1)
3788 ssh2_pkt_addstring_str(ssh, ",");
3789 }
3790 /* List client->server compression algorithms. */
3791 ssh2_pkt_addstring_start(ssh);
3792 for (i = 0; i < lenof(compressions) + 1; i++) {
3793 const struct ssh_compress *c =
3794 i == 0 ? s->preferred_comp : compressions[i - 1];
3795 ssh2_pkt_addstring_str(ssh, c->name);
3796 if (i < lenof(compressions))
3797 ssh2_pkt_addstring_str(ssh, ",");
3798 }
3799 /* List server->client compression algorithms. */
3800 ssh2_pkt_addstring_start(ssh);
3801 for (i = 0; i < lenof(compressions) + 1; i++) {
3802 const struct ssh_compress *c =
3803 i == 0 ? s->preferred_comp : compressions[i - 1];
3804 ssh2_pkt_addstring_str(ssh, c->name);
3805 if (i < lenof(compressions))
3806 ssh2_pkt_addstring_str(ssh, ",");
3807 }
3808 /* List client->server languages. Empty list. */
3809 ssh2_pkt_addstring_start(ssh);
3810 /* List server->client languages. Empty list. */
3811 ssh2_pkt_addstring_start(ssh);
3812 /* First KEX packet does _not_ follow, because we're not that brave. */
3813 ssh2_pkt_addbool(ssh, FALSE);
3814 /* Reserved. */
3815 ssh2_pkt_adduint32(ssh, 0);
e5574168 3816 }
0db56f73 3817
51470298 3818 ssh->exhash = ssh->exhashbase;
3819 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 3820
51470298 3821 ssh2_pkt_send(ssh);
e5574168 3822
32874aea 3823 if (!ispkt)
3824 crWaitUntil(ispkt);
57356d63 3825 if (ssh->pktin.length > 5)
3826 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 3827
3828 /*
3829 * Now examine the other side's KEXINIT to see what we're up
3830 * to.
3831 */
51470298 3832 {
3833 char *str;
3834 int i, j, len;
3835
3836 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
a8327734 3837 bombout((ssh,"expected key exchange packet from server"));
51470298 3838 crReturn(0);
32874aea 3839 }
51470298 3840 ssh->kex = NULL;
3841 ssh->hostkey = NULL;
3842 s->cscipher_tobe = NULL;
3843 s->sccipher_tobe = NULL;
3844 s->csmac_tobe = NULL;
3845 s->scmac_tobe = NULL;
3846 s->cscomp_tobe = NULL;
3847 s->sccomp_tobe = NULL;
3848 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3849 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3850 for (i = 0; i < lenof(kex_algs); i++) {
3851 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3852 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3853 continue;
3854 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3855 ssh->kex = kex_algs[i];
3856 break;
3857 }
32874aea 3858 }
51470298 3859 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3860 for (i = 0; i < lenof(hostkey_algs); i++) {
3861 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3862 ssh->hostkey = hostkey_algs[i];
3863 break;
3864 }
3865 }
3866 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3867 s->warn = 0;
3868 for (i = 0; i < s->n_preferred_ciphers; i++) {
3869 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3870 if (!c) {
3871 s->warn = 1;
3872 } else {
3873 for (j = 0; j < c->nciphers; j++) {
3874 if (in_commasep_string(c->list[j]->name, str, len)) {
3875 s->cscipher_tobe = c->list[j];
3876 break;
3877 }
ca20bfcf 3878 }
32874aea 3879 }
51470298 3880 if (s->cscipher_tobe) {
3881 if (s->warn)
a8327734 3882 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 3883 break;
3884 }
32874aea 3885 }
51470298 3886 if (!s->cscipher_tobe) {
57356d63 3887 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3888 str ? str : "(null)"));
51470298 3889 crReturn(0);
ca20bfcf 3890 }
0ef8f407 3891
51470298 3892 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3893 s->warn = 0;
3894 for (i = 0; i < s->n_preferred_ciphers; i++) {
3895 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3896 if (!c) {
3897 s->warn = 1;
3898 } else {
3899 for (j = 0; j < c->nciphers; j++) {
3900 if (in_commasep_string(c->list[j]->name, str, len)) {
3901 s->sccipher_tobe = c->list[j];
3902 break;
3903 }
ca20bfcf 3904 }
32874aea 3905 }
51470298 3906 if (s->sccipher_tobe) {
3907 if (s->warn)
a8327734 3908 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 3909 break;
3910 }
32874aea 3911 }
51470298 3912 if (!s->sccipher_tobe) {
57356d63 3913 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3914 str ? str : "(null)"));
51470298 3915 crReturn(0);
ca20bfcf 3916 }
0ef8f407 3917
51470298 3918 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3919 for (i = 0; i < s->nmacs; i++) {
3920 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3921 s->csmac_tobe = s->maclist[i];
3922 break;
3923 }
32874aea 3924 }
51470298 3925 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3926 for (i = 0; i < s->nmacs; i++) {
3927 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3928 s->scmac_tobe = s->maclist[i];
3929 break;
3930 }
32874aea 3931 }
51470298 3932 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3933 for (i = 0; i < lenof(compressions) + 1; i++) {
3934 const struct ssh_compress *c =
3935 i == 0 ? s->preferred_comp : compressions[i - 1];
3936 if (in_commasep_string(c->name, str, len)) {
3937 s->cscomp_tobe = c;
3938 break;
3939 }
32874aea 3940 }
51470298 3941 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3942 for (i = 0; i < lenof(compressions) + 1; i++) {
3943 const struct ssh_compress *c =
3944 i == 0 ? s->preferred_comp : compressions[i - 1];
3945 if (in_commasep_string(c->name, str, len)) {
3946 s->sccomp_tobe = c;
3947 break;
3948 }
32874aea 3949 }
e5574168 3950 }
e5574168 3951
3952 /*
7bd5a860 3953 * Work out the number of bits of key we will need from the key
3954 * exchange. We start with the maximum key length of either
3955 * cipher...
3956 */
3957 {
32874aea 3958 int csbits, scbits;
7bd5a860 3959
51470298 3960 csbits = s->cscipher_tobe->keylen;
3961 scbits = s->sccipher_tobe->keylen;
3962 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 3963 }
3964 /* The keys only have 160-bit entropy, since they're based on
3965 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 3966 if (s->nbits > 160)
3967 s->nbits = 160;
7bd5a860 3968
3969 /*
a92dd380 3970 * If we're doing Diffie-Hellman group exchange, start by
3971 * requesting a group.
e5574168 3972 */
51470298 3973 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 3974 logevent("Doing Diffie-Hellman group exchange");
51470298 3975 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3976 /*
3977 * Work out how big a DH group we will need to allow that
3978 * much data.
7bd5a860 3979 */
51470298 3980 s->pbits = 512 << ((s->nbits - 1) / 64);
3981 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3982 ssh2_pkt_adduint32(ssh, s->pbits);
3983 ssh2_pkt_send(ssh);
32874aea 3984
3985 crWaitUntil(ispkt);
51470298 3986 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
a8327734 3987 bombout((ssh,"expected key exchange group packet from server"));
32874aea 3988 crReturn(0);
3989 }
51470298 3990 s->p = ssh2_pkt_getmp(ssh);
3991 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 3992 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 3993 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3994 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3995 } else {
51470298 3996 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 3997 ssh->kex_ctx = dh_setup_group1();
51470298 3998 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3999 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4000 }
e5574168 4001
a92dd380 4002 logevent("Doing Diffie-Hellman key exchange");
e5574168 4003 /*
a92dd380 4004 * Now generate and send e for Diffie-Hellman.
e5574168 4005 */
27cd7fc2 4006 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 4007 ssh2_pkt_init(ssh, s->kex_init_value);
4008 ssh2_pkt_addmp(ssh, s->e);
4009 ssh2_pkt_send(ssh);
e5574168 4010
4011 crWaitUntil(ispkt);
51470298 4012 if (ssh->pktin.type != s->kex_reply_value) {
a8327734 4013 bombout((ssh,"expected key exchange reply packet from server"));
32874aea 4014 crReturn(0);
7cca0d81 4015 }
51470298 4016 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4017 s->f = ssh2_pkt_getmp(ssh);
4018 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4019
27cd7fc2 4020 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4021
51470298 4022 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4023 if (ssh->kex == &ssh_diffiehellman_gex) {
4024 sha_uint32(&ssh->exhash, s->pbits);
4025 sha_mpint(&ssh->exhash, s->p);
4026 sha_mpint(&ssh->exhash, s->g);
a92dd380 4027 }
51470298 4028 sha_mpint(&ssh->exhash, s->e);
4029 sha_mpint(&ssh->exhash, s->f);
4030 sha_mpint(&ssh->exhash, s->K);
4031 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4032
27cd7fc2 4033 dh_cleanup(ssh->kex_ctx);
fabd1805 4034 ssh->kex_ctx = NULL;
3709bfe9 4035
7cca0d81 4036#if 0
765c4200 4037 debug(("Exchange hash is:\n"));
51470298 4038 dmemdump(s->exchange_hash, 20);
7cca0d81 4039#endif
4040
51470298 4041 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4042 if (!s->hkey ||
4043 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4044 (char *)s->exchange_hash, 20)) {
a8327734 4045 bombout((ssh,"Server's host key did not match the signature supplied"));
32874aea 4046 crReturn(0);
8d5de777 4047 }
e5574168 4048
4049 /*
7cca0d81 4050 * Authenticate remote host: verify host key. (We've already
4051 * checked the signature of the exchange hash.)
e5574168 4052 */
51470298 4053 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4054 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4055 verify_ssh_host_key(ssh->frontend,
4056 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4057 s->keystr, s->fingerprint);
4058 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4059 logevent("Host key fingerprint is:");
51470298 4060 logevent(s->fingerprint);
5e0d7cb8 4061 }
51470298 4062 sfree(s->fingerprint);
4063 sfree(s->keystr);
4064 ssh->hostkey->freekey(s->hkey);
d39f364a 4065
4066 /*
7cca0d81 4067 * Send SSH2_MSG_NEWKEYS.
d39f364a 4068 */
51470298 4069 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4070 ssh2_pkt_send(ssh);
d39f364a 4071
4072 /*
8406eaf9 4073 * Expect SSH2_MSG_NEWKEYS from server.
4074 */
4075 crWaitUntil(ispkt);
51470298 4076 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
a8327734 4077 bombout((ssh,"expected new-keys packet from server"));
8406eaf9 4078 crReturn(0);
4079 }
4080
4081 /*
d39f364a 4082 * Create and initialise session keys.
4083 */
371e569c 4084 if (ssh->cs_cipher_ctx)
4085 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4086 ssh->cscipher = s->cscipher_tobe;
371e569c 4087 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4088
371e569c 4089 if (ssh->sc_cipher_ctx)
4090 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4091 ssh->sccipher = s->sccipher_tobe;
371e569c 4092 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4093
4094 if (ssh->cs_mac_ctx)
4095 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4096 ssh->csmac = s->csmac_tobe;
e0e1a00d 4097 ssh->cs_mac_ctx = ssh->csmac->make_context();
4098
4099 if (ssh->sc_mac_ctx)
4100 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4101 ssh->scmac = s->scmac_tobe;
e0e1a00d 4102 ssh->sc_mac_ctx = ssh->scmac->make_context();
4103
5366aed8 4104 if (ssh->cs_comp_ctx)
4105 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4106 ssh->cscomp = s->cscomp_tobe;
5366aed8 4107 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4108
4109 if (ssh->sc_comp_ctx)
4110 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4111 ssh->sccomp = s->sccomp_tobe;
5366aed8 4112 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4113
d39f364a 4114 /*
5e0d7cb8 4115 * Set IVs after keys. Here we use the exchange hash from the
4116 * _first_ key exchange.
d39f364a 4117 */
51470298 4118 {
4119 unsigned char keyspace[40];
4120 if (s->first_kex)
4121 memcpy(ssh->v2_session_id, s->exchange_hash,
4122 sizeof(s->exchange_hash));
4123 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4124 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4125 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4126 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4127 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4128 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4129 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4130 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4131 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4132 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4133 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4134 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4135 }
57356d63 4136 logeventf(ssh, "Initialised %.200s client->server encryption",
4137 ssh->cscipher->text_name);
4138 logeventf(ssh, "Initialised %.200s server->client encryption",
4139 ssh->sccipher->text_name);
4140 if (ssh->cscomp->text_name)
4141 logeventf(ssh, "Initialised %s compression",
4142 ssh->cscomp->text_name);
4143 if (ssh->sccomp->text_name)
4144 logeventf(ssh, "Initialised %s decompression",
4145 ssh->sccomp->text_name);
d39f364a 4146
033b4cef 4147 /*
0db56f73 4148 * If this is the first key exchange phase, we must pass the
4149 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4150 * wants to see it but because it will need time to initialise
4151 * itself before it sees an actual packet. In subsequent key
4152 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4153 * it would only confuse the layer above.
4154 */
51470298 4155 if (!s->first_kex) {
32874aea 4156 crReturn(0);
0db56f73 4157 }
51470298 4158 s->first_kex = 0;
0db56f73 4159
4160 /*
7cca0d81 4161 * Now we're encrypting. Begin returning 1 to the protocol main
4162 * function so that other things can run on top of the
4163 * transport. If we ever see a KEXINIT, we must go back to the
4164 * start.
033b4cef 4165 */
51470298 4166 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4167 crReturn(1);
e96adf72 4168 }
5e0d7cb8 4169 logevent("Server initiated key re-exchange");
7cca0d81 4170 goto begin_key_exchange;
e5574168 4171
4172 crFinish(1);
4173}
4174
7cca0d81 4175/*
783415f8 4176 * Add data to an SSH2 channel output buffer.
4177 */
32874aea 4178static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4179 int len)
4180{
5471d09a 4181 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4182}
4183
4184/*
4185 * Attempt to send data on an SSH2 channel.
4186 */
5471d09a 4187static int ssh2_try_send(struct ssh_channel *c)
32874aea 4188{
51470298 4189 Ssh ssh = c->ssh;
4190
5471d09a 4191 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4192 int len;
4193 void *data;
4194 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4195 if ((unsigned)len > c->v.v2.remwindow)
4196 len = c->v.v2.remwindow;
4197 if ((unsigned)len > c->v.v2.remmaxpkt)
4198 len = c->v.v2.remmaxpkt;
51470298 4199 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4200 ssh2_pkt_adduint32(ssh, c->remoteid);
4201 ssh2_pkt_addstring_start(ssh);
4202 ssh2_pkt_addstring_data(ssh, data, len);
4203 ssh2_pkt_send(ssh);
5471d09a 4204 bufchain_consume(&c->v.v2.outbuffer, len);
4205 c->v.v2.remwindow -= len;
4206 }
4207
4208 /*
4209 * After having sent as much data as we can, return the amount
4210 * still buffered.
4211 */
4212 return bufchain_size(&c->v.v2.outbuffer);
4213}
4214
4215/*
4216 * Potentially enlarge the window on an SSH2 channel.
4217 */
4218static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4219{
51470298 4220 Ssh ssh = c->ssh;
4221
6b69f42e 4222 /*
4223 * Never send WINDOW_ADJUST for a channel that the remote side
4224 * already thinks it's closed; there's no point, since it won't
4225 * be sending any more data anyway.
4226 */
4227 if (c->closes != 0)
4228 return;
4229
5471d09a 4230 if (newwin > c->v.v2.locwindow) {
51470298 4231 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4232 ssh2_pkt_adduint32(ssh, c->remoteid);
4233 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4234 ssh2_pkt_send(ssh);
5471d09a 4235 c->v.v2.locwindow = newwin;
783415f8 4236 }
4237}
4238
4239/*
7cca0d81 4240 * Handle the SSH2 userauth and connection layers.
4241 */
51470298 4242static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4243{
51470298 4244 struct do_ssh2_authconn_state {
4245 enum {
4246 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4247 AUTH_PASSWORD,
4248 AUTH_KEYBOARD_INTERACTIVE
4249 } method;
4250 enum {
4251 AUTH_TYPE_NONE,
4252 AUTH_TYPE_PUBLICKEY,
4253 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4254 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4255 AUTH_TYPE_PASSWORD,
4256 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4257 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4258 } type;
4259 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4260 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4261 int kbd_inter_running;
4262 int we_are_in;
4263 int num_prompts, curr_prompt, echo;
4264 char username[100];
4265 int got_username;
4266 char pwprompt[200];
4267 char password[100];
4268 void *publickey_blob;
4269 int publickey_bloblen;
4270 unsigned char request[5], *response, *p;
4271 int responselen;
4272 int keyi, nkeys;
4273 int authed;
4274 char *pkblob, *alg, *commentp;
4275 int pklen, alglen, commentlen;
4276 int siglen, retlen, len;
4277 char *q, *agentreq, *ret;
4278 int try_send;
4279 };
4280 crState(do_ssh2_authconn_state);
4281
4282 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4283
7cca0d81 4284 /*
4285 * Request userauth protocol, and await a response to it.
4286 */
51470298 4287 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4288 ssh2_pkt_addstring(ssh, "ssh-userauth");
4289 ssh2_pkt_send(ssh);
7cca0d81 4290 crWaitUntilV(ispkt);
51470298 4291 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
a8327734 4292 bombout((ssh,"Server refused user authentication protocol"));
32874aea 4293 crReturnV;
8d5de777 4294 }
7cca0d81 4295
4296 /*
1408a877 4297 * We repeat this whole loop, including the username prompt,
4298 * until we manage a successful authentication. If the user
51470298 4299 * types the wrong _password_, they can be sent back to the
4300 * beginning to try another username, if this is configured on.
4301 * (If they specify a username in the config, they are never
4302 * asked, even if they do give a wrong password.)
1408a877 4303 *
4304 * I think this best serves the needs of
4305 *
4306 * - the people who have no configuration, no keys, and just
4307 * want to try repeated (username,password) pairs until they
4308 * type both correctly
4309 *
4310 * - people who have keys and configuration but occasionally
4311 * need to fall back to passwords
4312 *
4313 * - people with a key held in Pageant, who might not have
4314 * logged in to a particular machine before; so they want to
4315 * type a username, and then _either_ their key will be
4316 * accepted, _or_ they will type a password. If they mistype
4317 * the username they will want to be able to get back and
4318 * retype it!
7cca0d81 4319 */
51470298 4320 s->username[0] = '\0';
4321 s->got_username = FALSE;
1408a877 4322 do {
1408a877 4323 /*
4324 * Get a username.
4325 */
86916870 4326 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 4327 /*
4328 * We got a username last time round this loop, and
4329 * with change_username turned off we don't try to get
4330 * it again.
4331 */
86916870 4332 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 4333 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4334 if (!ssh_get_line("login as: ",
51470298 4335 s->username, sizeof(s->username), FALSE)) {
32874aea 4336 /*
4337 * get_line failed to get a username.
4338 * Terminate.
4339 */
4340 logevent("No username provided. Abandoning session.");
51470298 4341 ssh->state = SSH_STATE_CLOSED;
32874aea 4342 crReturnV;
4343 }
4344 } else {
51470298 4345 int ret; /* need not be saved across crReturn */
4346 c_write_str(ssh, "login as: ");
4347 ssh->send_ok = 1;
4348 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4349 do {
32874aea 4350 crWaitUntilV(!ispkt);
51470298 4351 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4352 } while (ret == 0);
4353 if (ret < 0)
4354 cleanup_exit(0);
4ca0c9d1 4355 c_write_str(ssh, "\r\n");
32874aea 4356 }
51470298 4357 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4358 } else {
57356d63 4359 char *stuff;
86916870 4360 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 4361 s->username[sizeof(s->username)-1] = '\0';
65a22376 4362 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 4363 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 4364 c_write_str(ssh, stuff);
57356d63 4365 sfree(stuff);
7cca0d81 4366 }
4367 }
51470298 4368 s->got_username = TRUE;
7cca0d81 4369
65a22376 4370 /*
1408a877 4371 * Send an authentication request using method "none": (a)
4372 * just in case it succeeds, and (b) so that we know what
4373 * authentication methods we can usefully try next.
65a22376 4374 */
51470298 4375 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4376
4377 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4378 ssh2_pkt_addstring(ssh, s->username);
4379 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4380 ssh2_pkt_addstring(ssh, "none"); /* method */
4381 ssh2_pkt_send(ssh);
4382 s->type = AUTH_TYPE_NONE;
4383 s->gotit = FALSE;
4384 s->we_are_in = FALSE;
4385
4386 s->tried_pubkey_config = FALSE;
4387 s->tried_agent = FALSE;
4388 s->tried_keyb_inter = FALSE;
4389 s->kbd_inter_running = FALSE;
86916870 4390 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 4391 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 4392 int keytype;
86916870 4393 logeventf(ssh, "Reading private key file \"%.150s\"", ssh->cfg.keyfile);
9a30e26b 4394 keytype = key_type(&ssh->cfg.keyfile);
51470298 4395 if (keytype == SSH_KEYTYPE_SSH2) {
4396 s->publickey_blob =
9a30e26b 4397 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
51470298 4398 &s->publickey_bloblen);
4399 } else {
57356d63 4400 char *msgbuf;
c2ad7d0d 4401 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 4402 key_type_to_str(keytype));
57356d63 4403 msgbuf = dupprintf("Unable to use key file \"%.150s\""
86916870 4404 " (%s)\r\n", ssh->cfg.keyfile,
57356d63 4405 key_type_to_str(keytype));
51470298 4406 c_write_str(ssh, msgbuf);
57356d63 4407 sfree(msgbuf);
51470298 4408 s->publickey_blob = NULL;
231ee168 4409 }
396778f1 4410 } else
51470298 4411 s->publickey_blob = NULL;
65a22376 4412
1408a877 4413 while (1) {
4414 /*
4415 * Wait for the result of the last authentication request.
4416 */
51470298 4417 if (!s->gotit)
1408a877 4418 crWaitUntilV(ispkt);
51470298 4419 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4420 char *banner;
4421 int size;
4422 /*
4423 * Don't show the banner if we're operating in
4424 * non-verbose non-interactive mode. (It's probably
4425 * a script, which means nobody will read the
4426 * banner _anyway_, and moreover the printing of
4427 * the banner will screw up processing on the
4428 * output of (say) plink.)
4429 */
4430 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4431 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4432 if (banner)
51470298 4433 c_write_untrusted(ssh, banner, size);
32874aea 4434 }
1408a877 4435 crWaitUntilV(ispkt);
4436 }
51470298 4437 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4438 logevent("Access granted");
51470298 4439 s->we_are_in = TRUE;
1408a877 4440 break;
4441 }
65a22376 4442
51470298 4443 if (s->kbd_inter_running &&
4444 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4445 /*
45068b27 4446 * This is either a further set-of-prompts packet
4447 * in keyboard-interactive authentication, or it's
4448 * the same one and we came back here with `gotit'
4449 * set. In the former case, we must reset the
4450 * curr_prompt variable.
b3186d64 4451 */
51470298 4452 if (!s->gotit)
4453 s->curr_prompt = 0;
4454 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
a8327734 4455 bombout((ssh,"Strange packet received during authentication: type %d",
51470298 4456 ssh->pktin.type));
38c4a8da 4457 crReturnV;
65a22376 4458 }
4459
51470298 4460 s->gotit = FALSE;
65a22376 4461
1408a877 4462 /*
4463 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4464 * we can look at the string in it and know what we can
4465 * helpfully try next.
4466 */
51470298 4467 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4468 char *methods;
4469 int methlen;
51470298 4470 ssh2_pkt_getstring(ssh, &methods, &methlen);
4471 s->kbd_inter_running = FALSE;
4472 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4473 /*
4474 * We have received an unequivocal Access
4475 * Denied. This can translate to a variety of
4476 * messages:
4477 *
4478 * - if we'd just tried "none" authentication,
4479 * it's not worth printing anything at all
4480 *
4481 * - if we'd just tried a public key _offer_,
4482 * the message should be "Server refused our
4483 * key" (or no message at all if the key
4484 * came from Pageant)
4485 *
4486 * - if we'd just tried anything else, the
4487 * message really should be "Access denied".
4488 *
4489 * Additionally, if we'd just tried password
4490 * authentication, we should break out of this
4491 * whole loop so as to go back to the username
4492 * prompt.
4493 */
51470298 4494 if (s->type == AUTH_TYPE_NONE) {
1408a877 4495 /* do nothing */
51470298 4496 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4497 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4498 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4499 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4500 logevent("Server refused public key");
51470298 4501 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4502 /* server declined keyboard-interactive; ignore */
1408a877 4503 } else {
51470298 4504 c_write_str(ssh, "Access denied\r\n");
1408a877 4505 logevent("Access denied");
51470298 4506 if (s->type == AUTH_TYPE_PASSWORD) {
4507 s->we_are_in = FALSE;
1408a877 4508 break;
4509 }
4510 }
4511 } else {
51470298 4512 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4513 logevent("Further authentication required");
4514 }
65a22376 4515
51470298 4516 s->can_pubkey =
32874aea 4517 in_commasep_string("publickey", methods, methlen);
51470298 4518 s->can_passwd =
32874aea 4519 in_commasep_string("password", methods, methlen);
86916870 4520 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 4521 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4522 }
65a22376 4523
51470298 4524 s->method = 0;
4525 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4526
0405e71f 4527 /*
4528 * Most password/passphrase prompts will be
4529 * non-echoing, so we set this to 0 by default.
4530 * Exception is that some keyboard-interactive prompts
4531 * can be echoing, in which case we'll set this to 1.
4532 */
51470298 4533 s->echo = 0;
0405e71f 4534
51470298 4535 if (!s->method && s->can_pubkey &&
4536 agent_exists() && !s->tried_agent) {
1983e559 4537 /*
4538 * Attempt public-key authentication using Pageant.
4539 */
1983e559 4540 void *r;
51470298 4541 s->authed = FALSE;
1983e559 4542
51470298 4543 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4544 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4545
51470298 4546 s->tried_agent = TRUE;
1983e559 4547
4548 logevent("Pageant is running. Requesting keys.");
4549
4550 /* Request the keys held by the agent. */
51470298 4551 PUT_32BIT(s->request, 1);
4552 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4553 agent_query(s->request, 5, &r, &s->responselen);
4554 s->response = (unsigned char *) r;
4555 if (s->response && s->responselen >= 5 &&
4556 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4557 s->p = s->response + 5;
4558 s->nkeys = GET_32BIT(s->p);
4559 s->p += 4;
32874aea 4560 {
4561 char buf[64];
51470298 4562 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4563 logevent(buf);
4564 }
51470298 4565 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4566 void *vret;
1983e559 4567
32874aea 4568 {
4569 char buf[64];
51470298 4570 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4571 logevent(buf);
4572 }
51470298 4573 s->pklen = GET_32BIT(s->p);
4574 s->p += 4;
4575 if (s->publickey_blob &&
4576 s->pklen == s->publickey_bloblen &&
4577 !memcmp(s->p, s->publickey_blob,
4578 s->publickey_bloblen)) {
396778f1 4579 logevent("This key matches configured key file");
51470298 4580 s->tried_pubkey_config = 1;
396778f1 4581 }
d8baa528 4582 s->pkblob = (char *)s->p;
51470298 4583 s->p += s->pklen;
4584 s->alglen = GET_32BIT(s->pkblob);
4585 s->alg = s->pkblob + 4;
4586 s->commentlen = GET_32BIT(s->p);
4587 s->p += 4;
d8baa528 4588 s->commentp = (char *)s->p;
51470298 4589 s->p += s->commentlen;
4590 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4591 ssh2_pkt_addstring(ssh, s->username);
4592 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4593 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4594 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4595 ssh2_pkt_addstring_start(ssh);
4596 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4597 ssh2_pkt_addstring_start(ssh);
4598 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4599 ssh2_pkt_send(ssh);
1983e559 4600
4601 crWaitUntilV(ispkt);
51470298 4602 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4603 logevent("Key refused");
4604 continue;
4605 }
4606
32874aea 4607 if (flags & FLAG_VERBOSE) {
51470298 4608 c_write_str(ssh, "Authenticating with "
4609 "public key \"");
4610 c_write(ssh, s->commentp, s->commentlen);
4611 c_write_str(ssh, "\" from agent\r\n");
32874aea 4612 }
1983e559 4613
4614 /*
4615 * Server is willing to accept the key.
4616 * Construct a SIGN_REQUEST.
4617 */
51470298 4618 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4619 ssh2_pkt_addstring(ssh, s->username);
4620 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4621 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4622 ssh2_pkt_addbool(ssh, TRUE);
4623 ssh2_pkt_addstring_start(ssh);
4624 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4625 ssh2_pkt_addstring_start(ssh);
4626 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4627
4628 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4629 s->len = 1; /* message type */
4630 s->len += 4 + s->pklen; /* key blob */
4631 s->len += 4 + s->siglen; /* data to sign */
4632 s->len += 4; /* flags */
4633 s->agentreq = smalloc(4 + s->len);
4634 PUT_32BIT(s->agentreq, s->len);
4635 s->q = s->agentreq + 4;
4636 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4637 PUT_32BIT(s->q, s->pklen);
4638 s->q += 4;
4639 memcpy(s->q, s->pkblob, s->pklen);
4640 s->q += s->pklen;
4641 PUT_32BIT(s->q, s->siglen);
4642 s->q += 4;
1983e559 4643 /* Now the data to be signed... */
51470298 4644 PUT_32BIT(s->q, 20);
4645 s->q += 4;
4646 memcpy(s->q, ssh->v2_session_id, 20);
4647 s->q += 20;
4648 memcpy(s->q, ssh->pktout.data + 5,
4649 ssh->pktout.length - 5);
4650 s->q += ssh->pktout.length - 5;
1983e559 4651 /* And finally the (zero) flags word. */
51470298 4652 PUT_32BIT(s->q, 0);
4653 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4654 s->ret = vret;
4655 sfree(s->agentreq);
4656 if (s->ret) {
4657 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4658 logevent("Sending Pageant's response");
51470298 4659 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4660 s->ret + 9,
4661 GET_32BIT(s->ret + 5));
4662 ssh2_pkt_send(ssh);
4663 s->authed = TRUE;
1983e559 4664 break;
4665 } else {
32874aea 4666 logevent
4667 ("Pageant failed to answer challenge");
51470298 4668 sfree(s->ret);
1983e559 4669 }
4670 }
4671 }
51470298 4672 if (s->authed)
1983e559 4673 continue;
4674 }
4675 }
4676
51470298 4677 if (!s->method && s->can_pubkey && s->publickey_blob
4678 && !s->tried_pubkey_config) {
1408a877 4679 unsigned char *pub_blob;
4680 char *algorithm, *comment;
4681 int pub_blob_len;
65a22376 4682
51470298 4683 s->tried_pubkey_config = TRUE;
65a22376 4684
51470298 4685 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4686 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4687
65a22376 4688 /*
1408a877 4689 * Try the public key supplied in the configuration.
4690 *
4691 * First, offer the public blob to see if the server is
4692 * willing to accept it.
65a22376 4693 */
d8baa528 4694 pub_blob =
9a30e26b 4695 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 4696 &algorithm,
4697 &pub_blob_len);
1408a877 4698 if (pub_blob) {
51470298 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, FALSE); /* no signature included */
4704 ssh2_pkt_addstring(ssh, algorithm);
4705 ssh2_pkt_addstring_start(ssh);
d8baa528 4706 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4707 pub_blob_len);
51470298 4708 ssh2_pkt_send(ssh);
32874aea 4709 logevent("Offered public key"); /* FIXME */
1408a877 4710
4711 crWaitUntilV(ispkt);
51470298 4712 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4713 s->gotit = TRUE;
4714 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4715 continue; /* key refused; give up on it */
1408a877 4716 }
65a22376 4717
1408a877 4718 logevent("Offer of public key accepted");
65a22376 4719 /*
1408a877 4720 * Actually attempt a serious authentication using
4721 * the key.
65a22376 4722 */
9a30e26b 4723 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 4724 sprintf(s->pwprompt,
32874aea 4725 "Passphrase for key \"%.100s\": ",
4726 comment);
51470298 4727 s->need_pw = TRUE;
1408a877 4728 } else {
51470298 4729 s->need_pw = FALSE;
1408a877 4730 }
51470298 4731 c_write_str(ssh, "Authenticating with public key \"");
4732 c_write_str(ssh, comment);
4733 c_write_str(ssh, "\"\r\n");
4734 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4735 }
1408a877 4736 }
4737
51470298 4738 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4739 s->method = AUTH_KEYBOARD_INTERACTIVE;
4740 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4741 s->tried_keyb_inter = TRUE;
af659722 4742
51470298 4743 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4744 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4745
51470298 4746 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4747 ssh2_pkt_addstring(ssh, s->username);
4748 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4749 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4750 ssh2_pkt_addstring(ssh, ""); /* lang */
4751 ssh2_pkt_addstring(ssh, "");
4752 ssh2_pkt_send(ssh);
af659722 4753
4754 crWaitUntilV(ispkt);
51470298 4755 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4756 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4757 s->gotit = TRUE;
af659722 4758 logevent("Keyboard-interactive authentication refused");
51470298 4759 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4760 continue;
4761 }
4762
51470298 4763 s->kbd_inter_running = TRUE;
4764 s->curr_prompt = 0;
af659722 4765 }
4766
51470298 4767 if (s->kbd_inter_running) {
4768 s->method = AUTH_KEYBOARD_INTERACTIVE;
4769 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4770 s->tried_keyb_inter = TRUE;
af659722 4771
51470298 4772 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4773 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4774
51470298 4775 if (s->curr_prompt == 0) {
45068b27 4776 /*
4777 * We've got a fresh USERAUTH_INFO_REQUEST.
4778 * Display header data, and start going through
4779 * the prompts.
4780 */
4781 char *name, *inst, *lang;
4782 int name_len, inst_len, lang_len;
4783
51470298 4784 ssh2_pkt_getstring(ssh, &name, &name_len);
4785 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4786 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 4787 if (name_len > 0) {
51470298 4788 c_write_untrusted(ssh, name, name_len);
4789 c_write_str(ssh, "\r\n");
45068b27 4790 }
4791 if (inst_len > 0) {
51470298 4792 c_write_untrusted(ssh, inst, inst_len);
4793 c_write_str(ssh, "\r\n");
45068b27 4794 }
51470298 4795 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 4796 }
af659722 4797
45068b27 4798 /*
4799 * If there are prompts remaining in the packet,
4800 * display one and get a response.
4801 */
51470298 4802 if (s->curr_prompt < s->num_prompts) {
45068b27 4803 char *prompt;
4804 int prompt_len;
af659722 4805
51470298 4806 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 4807 if (prompt_len > 0) {
51470298 4808 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4809 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4810 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 4811 } else {
51470298 4812 strcpy(s->pwprompt,
45068b27 4813 "<server failed to send prompt>: ");
4814 }
51470298 4815 s->echo = ssh2_pkt_getbool(ssh);
4816 s->need_pw = TRUE;
45068b27 4817 } else
51470298 4818 s->need_pw = FALSE;
af659722 4819 }
4820
51470298 4821 if (!s->method && s->can_passwd) {
4822 s->method = AUTH_PASSWORD;
4823 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4824 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4825 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4826 ssh->savedhost);
4827 s->need_pw = TRUE;
1408a877 4828 }
4829
51470298 4830 if (s->need_pw) {
fa17a66e 4831 if (ssh_get_line) {
51470298 4832 if (!ssh_get_line(s->pwprompt, s->password,
4833 sizeof(s->password), TRUE)) {
1408a877 4834 /*
fa17a66e 4835 * get_line failed to get a password (for
4836 * example because one was supplied on the
4837 * command line which has already failed to
4838 * work). Terminate.
1408a877 4839 */
51470298 4840 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4841 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4842 ssh2_pkt_addstring(ssh, "No more passwords available"
4843 " to try");
4844 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4845 ssh2_pkt_send(ssh);
247308b5 4846 logevent("Unable to authenticate");
a8327734 4847 connection_fatal(ssh->frontend,
4848 "Unable to authenticate");
51470298 4849 ssh->state = SSH_STATE_CLOSED;
1408a877 4850 crReturnV;
4851 }
4852 } else {
51470298 4853 int ret; /* need not be saved across crReturn */
4854 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4855 ssh->send_ok = 1;
1408a877 4856
51470298 4857 setup_userpass_input(ssh, s->password,
4858 sizeof(s->password), s->echo);
0405e71f 4859 do {
1408a877 4860 crWaitUntilV(!ispkt);
51470298 4861 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4862 } while (ret == 0);
4863 if (ret < 0)
4864 cleanup_exit(0);
51470298 4865 c_write_str(ssh, "\r\n");
65a22376 4866 }
65a22376 4867 }
65a22376 4868
51470298 4869 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 4870 /*
4871 * We have our passphrase. Now try the actual authentication.
4872 */
4873 struct ssh2_userkey *key;
65a22376 4874
9a30e26b 4875 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
1408a877 4876 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4877 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 4878 c_write_str(ssh, "Wrong passphrase\r\n");
4879 s->tried_pubkey_config = FALSE;
1408a877 4880 } else {
51470298 4881 c_write_str(ssh, "Unable to load private key\r\n");
4882 s->tried_pubkey_config = TRUE;
1408a877 4883 }
4884 /* Send a spurious AUTH_NONE to return to the top. */
51470298 4885 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4886 ssh2_pkt_addstring(ssh, s->username);
4887 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4888 ssh2_pkt_addstring(ssh, "none"); /* method */
4889 ssh2_pkt_send(ssh);
4890 s->type = AUTH_TYPE_NONE;
1408a877 4891 } else {
1dd353b5 4892 unsigned char *pkblob, *sigblob, *sigdata;
4893 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4894
1408a877 4895 /*
4896 * We have loaded the private key and the server
4897 * has announced that it's willing to accept it.
4898 * Hallelujah. Generate a signature and send it.
4899 */
51470298 4900 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4901 ssh2_pkt_addstring(ssh, s->username);
4902 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4903 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4904 ssh2_pkt_addbool(ssh, TRUE);
4905 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 4906 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 4907 ssh2_pkt_addstring_start(ssh);
d8baa528 4908 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
1408a877 4909
4910 /*
4911 * The data to be signed is:
4912 *
4913 * string session-id
4914 *
4915 * followed by everything so far placed in the
4916 * outgoing packet.
4917 */
51470298 4918 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
1408a877 4919 sigdata = smalloc(sigdata_len);
4920 PUT_32BIT(sigdata, 20);
51470298 4921 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4922 memcpy(sigdata + 24, ssh->pktout.data + 5,
4923 ssh->pktout.length - 5);
d8baa528 4924 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 4925 sigdata_len, &sigblob_len);
51470298 4926 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 4927 sigblob, sigblob_len);
4928 sfree(pkblob);
4929 sfree(sigblob);
1408a877 4930 sfree(sigdata);
4931
51470298 4932 ssh2_pkt_send(ssh);
4933 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 4934 }
51470298 4935 } else if (s->method == AUTH_PASSWORD) {
65a22376 4936 /*
1408a877 4937 * We send the password packet lumped tightly together with
4938 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4939 * string long enough to make the total length of the two
4940 * packets constant. This should ensure that a passive
4941 * listener doing traffic analyis can't work out the length
4942 * of the password.
4943 *
4944 * For this to work, we need an assumption about the
4945 * maximum length of the password packet. I think 256 is
4946 * pretty conservative. Anyone using a password longer than
4947 * that probably doesn't have much to worry about from
4948 * people who find out how long their password is!
65a22376 4949 */
51470298 4950 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4951 ssh2_pkt_addstring(ssh, s->username);
4952 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4953 ssh2_pkt_addstring(ssh, "password");
4954 ssh2_pkt_addbool(ssh, FALSE);
4955 ssh2_pkt_addstring(ssh, s->password);
1409c1b3 4956 memset(s->password, 0, sizeof(s->password));
51470298 4957 ssh2_pkt_defer(ssh);
65a22376 4958 /*
1408a877 4959 * We'll include a string that's an exact multiple of the
4960 * cipher block size. If the cipher is NULL for some
4961 * reason, we don't do this trick at all because we gain
4962 * nothing by it.
65a22376 4963 */
51470298 4964 if (ssh->cscipher) {
32874aea 4965 int stringlen, i;
4966
51470298 4967 stringlen = (256 - ssh->deferred_len);
4968 stringlen += ssh->cscipher->blksize - 1;
4969 stringlen -= (stringlen % ssh->cscipher->blksize);
4970 if (ssh->cscomp) {
32874aea 4971 /*
4972 * Temporarily disable actual compression,
4973 * so we can guarantee to get this string
4974 * exactly the length we want it. The
4975 * compression-disabling routine should
4976 * return an integer indicating how many
4977 * bytes we should adjust our string length
4978 * by.
4979 */
5366aed8 4980 stringlen -=
4981 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 4982 }
51470298 4983 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4984 ssh2_pkt_addstring_start(ssh);
6e9e9520 4985 for (i = 0; i < stringlen; i++) {
32874aea 4986 char c = (char) random_byte();
51470298 4987 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 4988 }
51470298 4989 ssh2_pkt_defer(ssh);
65a22376 4990 }
51470298 4991 ssh_pkt_defersend(ssh);
0d43337a 4992 logevent("Sent password");
51470298 4993 s->type = AUTH_TYPE_PASSWORD;
4994 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4995 if (s->curr_prompt == 0) {
4996 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4997 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 4998 }
51470298 4999 if (s->need_pw) { /* only add pw if we just got one! */
5000 ssh2_pkt_addstring(ssh, s->password);
5001 memset(s->password, 0, sizeof(s->password));
5002 s->curr_prompt++;
45068b27 5003 }
51470298 5004 if (s->curr_prompt >= s->num_prompts) {
5005 ssh2_pkt_send(ssh);
45068b27 5006 } else {
5007 /*
5008 * If there are prompts remaining, we set
5009 * `gotit' so that we won't attempt to get
5010 * another packet. Then we go back round the
5011 * loop and will end up retrieving another
5012 * prompt out of the existing packet. Funky or
5013 * what?
5014 */
51470298 5015 s->gotit = TRUE;
45068b27 5016 }
51470298 5017 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5018 } else {
51470298 5019 c_write_str(ssh, "No supported authentication methods"
5020 " left to try!\r\n");
5021 logevent("No supported authentications offered."
5022 " Disconnecting");
5023 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5024 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5025 ssh2_pkt_addstring(ssh, "No supported authentication"
5026 " methods available");
5027 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5028 ssh2_pkt_send(ssh);
5029 ssh->state = SSH_STATE_CLOSED;
1408a877 5030 crReturnV;
65a22376 5031 }
65a22376 5032 }
51470298 5033 } while (!s->we_are_in);
7cca0d81 5034
5035 /*
5036 * Now we're authenticated for the connection protocol. The
5037 * connection protocol will automatically have started at this
5038 * point; there's no need to send SERVICE_REQUEST.
5039 */
5040
5041 /*
5042 * So now create a channel with a session in it.
5043 */
51470298 5044 ssh->channels = newtree234(ssh_channelcmp);
5045 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5046 ssh->mainchan->ssh = ssh;
5047 ssh->mainchan->localid = alloc_channel_id(ssh);
5048 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5049 ssh2_pkt_addstring(ssh, "session");
5050 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5051 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5052 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5053 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5054 ssh2_pkt_send(ssh);
7cca0d81 5055 crWaitUntilV(ispkt);
51470298 5056 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
a8327734 5057 bombout((ssh,"Server refused to open a session"));
32874aea 5058 crReturnV;
5059 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5060 }
51470298 5061 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
a8327734 5062 bombout((ssh,"Server's channel confirmation cited wrong channel"));
32874aea 5063 crReturnV;
7cca0d81 5064 }
51470298 5065 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5066 ssh->mainchan->type = CHAN_MAINSESSION;
5067 ssh->mainchan->closes = 0;
5068 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5069 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5070 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5071 add234(ssh->channels, ssh->mainchan);
7cca0d81 5072 logevent("Opened channel for session");
5073
5074 /*
783415f8 5075 * Potentially enable X11 forwarding.
5076 */
86916870 5077 if (ssh->cfg.x11_forward) {
32874aea 5078 char proto[20], data[64];
5079 logevent("Requesting X11 forwarding");
302121de 5080 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5081 data, sizeof(data), ssh->cfg.x11_auth);
5082 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 5083 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5084 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5085 ssh2_pkt_addstring(ssh, "x11-req");
5086 ssh2_pkt_addbool(ssh, 1); /* want reply */
5087 ssh2_pkt_addbool(ssh, 0); /* many connections */
5088 ssh2_pkt_addstring(ssh, proto);
5089 ssh2_pkt_addstring(ssh, data);
86916870 5090 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
51470298 5091 ssh2_pkt_send(ssh);
32874aea 5092
5093 do {
5094 crWaitUntilV(ispkt);
51470298 5095 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5096 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5097 struct ssh_channel *c;
51470298 5098 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5099 if (!c)
5100 continue; /* nonexistent channel */
51470298 5101 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5102 }
51470298 5103 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5104
51470298 5105 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5106 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5107 bombout((ssh,"Unexpected response to X11 forwarding request:"
51470298 5108 " packet type %d", ssh->pktin.type));
32874aea 5109 crReturnV;
5110 }
5111 logevent("X11 forwarding refused");
5112 } else {
5113 logevent("X11 forwarding enabled");
51470298 5114 ssh->X11_fwd_enabled = TRUE;
32874aea 5115 }
783415f8 5116 }
5117
5118 /*
bc240b21 5119 * Enable port forwardings.
5120 */
5121 {
bc240b21 5122 char type;
5123 int n;
a4fc0d74 5124 int sport,dport,sserv,dserv;
6ee9b735 5125 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5126
51470298 5127 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5128 /* Add port forwardings. */
86916870 5129 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5130 while (*ssh->portfwd_strptr) {
5131 type = *ssh->portfwd_strptr++;
6ee9b735 5132 saddr[0] = '\0';
bc240b21 5133 n = 0;
6ee9b735 5134 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5135 if (*ssh->portfwd_strptr == ':') {
5136 /*
5137 * We've seen a colon in the middle of the
5138 * source port number. This means that
5139 * everything we've seen until now is the
5140 * source _address_, so we'll move it into
5141 * saddr and start sports from the beginning
5142 * again.
5143 */
5144 ssh->portfwd_strptr++;
5145 sports[n] = '\0';
5146 strcpy(saddr, sports);
5147 n = 0;
5148 }
5149 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5150 }
bc240b21 5151 sports[n] = 0;
51470298 5152 if (*ssh->portfwd_strptr == '\t')
5153 ssh->portfwd_strptr++;
bc240b21 5154 n = 0;
6ee9b735 5155 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5156 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5157 }
bc240b21 5158 host[n] = 0;
51470298 5159 if (*ssh->portfwd_strptr == ':')
5160 ssh->portfwd_strptr++;
bc240b21 5161 n = 0;
6ee9b735 5162 while (*ssh->portfwd_strptr) {
5163 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5164 }
bc240b21 5165 dports[n] = 0;
51470298 5166 ssh->portfwd_strptr++;
bc240b21 5167 dport = atoi(dports);
a4fc0d74 5168 dserv = 0;
5169 if (dport == 0) {
5170 dserv = 1;
68a49acb 5171 dport = net_service_lookup(dports);
5172 if (!dport) {
57356d63 5173 logeventf(ssh, "Service lookup failed for destination"
5174 " port \"%s\"", dports);
a4fc0d74 5175 }
5176 }
bc240b21 5177 sport = atoi(sports);
a4fc0d74 5178 sserv = 0;
5179 if (sport == 0) {
5180 sserv = 1;
68a49acb 5181 sport = net_service_lookup(sports);
5182 if (!sport) {
57356d63 5183 logeventf(ssh, "Service lookup failed for source"
5184 " port \"%s\"", sports);
a4fc0d74 5185 }
5186 }
bc240b21 5187 if (sport && dport) {
5188 if (type == 'L') {
6ee9b735 5189 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 5190 sport, ssh, &ssh->cfg);
6ee9b735 5191 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5192 " forwarding to %s:%.*s%.*s%d%.*s",
5193 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5194 (int)(*saddr?1:0), ":",
57356d63 5195 (int)(sserv ? strlen(sports) : 0), sports,
5196 sserv, "(", sport, sserv, ")",
5197 host,
5198 (int)(dserv ? strlen(dports) : 0), dports,
5199 dserv, "(", dport, dserv, ")");
bc240b21 5200 } else {
5201 struct ssh_rportfwd *pf;
5202 pf = smalloc(sizeof(*pf));
5203 strcpy(pf->dhost, host);
5204 pf->dport = dport;
5205 pf->sport = sport;
51470298 5206 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5207 logeventf(ssh, "Duplicate remote port forwarding"
5208 " to %s:%d", host, dport);
bc240b21 5209 sfree(pf);
5210 } else {
6ee9b735 5211 logeventf(ssh, "Requesting remote port "
5212 "%.*s%.*s%.*s%.*s%d%.*s"
57356d63 5213 " forward to %s:%.*s%.*s%d%.*s",
6ee9b735 5214 (int)(*saddr?strlen(saddr):0),
5215 *saddr?saddr:NULL,
5216 (int)(*saddr?1:0), ":",
57356d63 5217 (int)(sserv ? strlen(sports) : 0), sports,
5218 sserv, "(", sport, sserv, ")",
5219 host,
5220 (int)(dserv ? strlen(dports) : 0), dports,
5221 dserv, "(", dport, dserv, ")");
51470298 5222 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5223 ssh2_pkt_addstring(ssh, "tcpip-forward");
5224 ssh2_pkt_addbool(ssh, 1);/* want reply */
6ee9b735 5225 if (*saddr)
5226 ssh2_pkt_addstring(ssh, saddr);
86916870 5227 if (ssh->cfg.rport_acceptall)
51470298 5228 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5229 else
51470298 5230 ssh2_pkt_addstring(ssh, "127.0.0.1");
5231 ssh2_pkt_adduint32(ssh, sport);
5232 ssh2_pkt_send(ssh);
bc240b21 5233
5234 do {
5235 crWaitUntilV(ispkt);
51470298 5236 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5237 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5238 struct ssh_channel *c;
51470298 5239 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5240 if (!c)
5241 continue;/* nonexistent channel */
51470298 5242 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5243 }
51470298 5244 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5245
51470298 5246 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5247 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
a8327734 5248 bombout((ssh,"Unexpected response to port "
c9886e66 5249 "forwarding request: packet type %d",
51470298 5250 ssh->pktin.type));
bc240b21 5251 crReturnV;
5252 }
5253 logevent("Server refused this port forwarding");
5254 } else {
5255 logevent("Remote port forwarding enabled");
5256 }
5257 }
5258 }
5259 }
5260 }
5261 }
5262
5263 /*
36c2a3e9 5264 * Potentially enable agent forwarding.
5265 */
86916870 5266 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 5267 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5268 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5269 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5270 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5271 ssh2_pkt_addbool(ssh, 1); /* want reply */
5272 ssh2_pkt_send(ssh);
32874aea 5273
5274 do {
5275 crWaitUntilV(ispkt);
51470298 5276 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5277 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5278 struct ssh_channel *c;
51470298 5279 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5280 if (!c)
5281 continue; /* nonexistent channel */
51470298 5282 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5283 }
51470298 5284 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5285
51470298 5286 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5287 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5288 bombout((ssh,"Unexpected response to agent forwarding request:"
51470298 5289 " packet type %d", ssh->pktin.type));
32874aea 5290 crReturnV;
5291 }
5292 logevent("Agent forwarding refused");
5293 } else {
5294 logevent("Agent forwarding enabled");
51470298 5295 ssh->agentfwd_enabled = TRUE;
32874aea 5296 }
36c2a3e9 5297 }
5298
5299 /*
7cca0d81 5300 * Now allocate a pty for the session.
5301 */
86916870 5302 if (!ssh->cfg.nopty) {
51470298 5303 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5304 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5305 ssh2_pkt_addstring(ssh, "pty-req");
5306 ssh2_pkt_addbool(ssh, 1); /* want reply */
86916870 5307 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
51470298 5308 ssh2_pkt_adduint32(ssh, ssh->term_width);
5309 ssh2_pkt_adduint32(ssh, ssh->term_height);
5310 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5311 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5312 ssh2_pkt_addstring_start(ssh);
5313 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5314 ssh2_pkt_send(ssh);
5315 ssh->state = SSH_STATE_INTERMED;
32874aea 5316
5317 do {
5318 crWaitUntilV(ispkt);
51470298 5319 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5320 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5321 struct ssh_channel *c;
51470298 5322 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5323 if (!c)
5324 continue; /* nonexistent channel */
51470298 5325 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5326 }
51470298 5327 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5328
51470298 5329 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5330 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5331 bombout((ssh,"Unexpected response to pty request:"
51470298 5332 " packet type %d", ssh->pktin.type));
32874aea 5333 crReturnV;
5334 }
51470298 5335 c_write_str(ssh, "Server refused to allocate pty\r\n");
5336 ssh->editing = ssh->echoing = 1;
32874aea 5337 } else {
5338 logevent("Allocated pty");
5339 }
0965bee0 5340 } else {
51470298 5341 ssh->editing = ssh->echoing = 1;
7cca0d81 5342 }
5343
5344 /*
fd5e5847 5345 * Start a shell or a remote command. We may have to attempt
5346 * this twice if the config data has provided a second choice
5347 * of command.
7cca0d81 5348 */
fd5e5847 5349 while (1) {
5350 int subsys;
5351 char *cmd;
5352
51470298 5353 if (ssh->fallback_cmd) {
86916870 5354 subsys = ssh->cfg.ssh_subsys2;
5355 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 5356 } else {
86916870 5357 subsys = ssh->cfg.ssh_subsys;
5358 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 5359 }
5360
51470298 5361 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5362 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5363 if (subsys) {
51470298 5364 ssh2_pkt_addstring(ssh, "subsystem");
5365 ssh2_pkt_addbool(ssh, 1); /* want reply */
5366 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5367 } else if (*cmd) {
51470298 5368 ssh2_pkt_addstring(ssh, "exec");
5369 ssh2_pkt_addbool(ssh, 1); /* want reply */
5370 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5371 } else {
51470298 5372 ssh2_pkt_addstring(ssh, "shell");
5373 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5374 }
51470298 5375 ssh2_pkt_send(ssh);
fd5e5847 5376 do {
5377 crWaitUntilV(ispkt);
51470298 5378 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5379 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5380 struct ssh_channel *c;
51470298 5381 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5382 if (!c)
5383 continue; /* nonexistent channel */
51470298 5384 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5385 }
51470298 5386 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5387 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5388 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5389 bombout((ssh,"Unexpected response to shell/command request:"
51470298 5390 " packet type %d", ssh->pktin.type));
fd5e5847 5391 crReturnV;
5392 }
5393 /*
5394 * We failed to start the command. If this is the
5395 * fallback command, we really are finished; if it's
5396 * not, and if the fallback command exists, try falling
5397 * back to it before complaining.
5398 */
86916870 5399 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5400 logevent("Primary command failed; attempting fallback");
51470298 5401 ssh->fallback_cmd = TRUE;
fd5e5847 5402 continue;
5403 }
a8327734 5404 bombout((ssh,"Server refused to start a shell/command"));
32874aea 5405 crReturnV;
fd5e5847 5406 } else {
5407 logevent("Started a shell/command");
32874aea 5408 }
fd5e5847 5409 break;
7cca0d81 5410 }
5411
51470298 5412 ssh->state = SSH_STATE_SESSION;
5413 if (ssh->size_needed)
5414 ssh_size(ssh, ssh->term_width, ssh->term_height);
5415 if (ssh->eof_needed)
5416 ssh_special(ssh, TS_EOF);
6e48c3fe 5417
7cca0d81 5418 /*
5419 * Transfer data!
5420 */
b9d7bcad 5421 if (ssh->ldisc)
5422 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5423 ssh->send_ok = 1;
7cca0d81 5424 while (1) {
e5574168 5425 crReturnV;
51470298 5426 s->try_send = FALSE;
7cca0d81 5427 if (ispkt) {
51470298 5428 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5429 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5430 char *data;
5431 int length;
51470298 5432 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5433 struct ssh_channel *c;
51470298 5434 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5435 if (!c)
5436 continue; /* nonexistent channel */
51470298 5437 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5438 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5439 continue; /* extended but not stderr */
51470298 5440 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5441 if (data) {
5471d09a 5442 int bufsize;
5443 c->v.v2.locwindow -= length;
32874aea 5444 switch (c->type) {
5445 case CHAN_MAINSESSION:
5471d09a 5446 bufsize =
51470298 5447 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5448 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5449 data, length);
32874aea 5450 break;
5451 case CHAN_X11:
5471d09a 5452 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5453 break;
d74d141c 5454 case CHAN_SOCKDATA:
5471d09a 5455 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5456 break;
36c2a3e9 5457 case CHAN_AGENT:
32874aea 5458 while (length > 0) {
5459 if (c->u.a.lensofar < 4) {
5460 int l = min(4 - c->u.a.lensofar, length);
5461 memcpy(c->u.a.msglen + c->u.a.lensofar,
5462 data, l);
5463 data += l;
5464 length -= l;
5465 c->u.a.lensofar += l;
5466 }
5467 if (c->u.a.lensofar == 4) {
5468 c->u.a.totallen =
5469 4 + GET_32BIT(c->u.a.msglen);
5470 c->u.a.message = smalloc(c->u.a.totallen);
5471 memcpy(c->u.a.message, c->u.a.msglen, 4);
5472 }
5473 if (c->u.a.lensofar >= 4 && length > 0) {
5474 int l =
5475 min(c->u.a.totallen - c->u.a.lensofar,
5476 length);
5477 memcpy(c->u.a.message + c->u.a.lensofar,
5478 data, l);
5479 data += l;
5480 length -= l;
5481 c->u.a.lensofar += l;
5482 }
5483 if (c->u.a.lensofar == c->u.a.totallen) {
5484 void *reply, *sentreply;
5485 int replylen;
5486 agent_query(c->u.a.message,
5487 c->u.a.totallen, &reply,
5488 &replylen);
5489 if (reply)
5490 sentreply = reply;
5491 else {
5492 /* Fake SSH_AGENT_FAILURE. */
5493 sentreply = "\0\0\0\1\5";
5494 replylen = 5;
5495 }
51470298 5496 ssh2_add_channel_data(c, sentreply, replylen);
5497 s->try_send = TRUE;
32874aea 5498 if (reply)
5499 sfree(reply);
5500 sfree(c->u.a.message);
5501 c->u.a.lensofar = 0;
5502 }
5503 }
5471d09a 5504 bufsize = 0;
32874aea 5505 break;
5506 }
5507 /*
5471d09a 5508 * If we are not buffering too much data,
5509 * enlarge the window again at the remote side.
32874aea 5510 */
5471d09a 5511 if (bufsize < OUR_V2_WINSIZE)
5512 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5513 }
51470298 5514 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5515 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5516 struct ssh_channel *c;
5517
51470298 5518 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5519 if (!c)
5520 continue; /* nonexistent channel */
5521
5522 if (c->type == CHAN_X11) {
5523 /*
5524 * Remote EOF on an X11 channel means we should
5525 * wrap up and close the channel ourselves.
5526 */
5527 x11_close(c->u.x11.s);
5528 sshfwd_close(c);
5529 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5530 sshfwd_close(c);
d74d141c 5531 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5532 pfd_close(c->u.pfd.s);
5533 sshfwd_close(c);
36c2a3e9 5534 }
51470298 5535 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5536 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5537 struct ssh_channel *c;
5538
51470298 5539 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5540 if (!c || ((int)c->remoteid) == -1) {
a8327734 5541 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 5542 c ? "half-open" : "nonexistent", i));
5543 }
32874aea 5544 /* Do pre-close processing on the channel. */
5545 switch (c->type) {
5546 case CHAN_MAINSESSION:
5547 break; /* nothing to see here, move along */
5548 case CHAN_X11:
92f157bd 5549 if (c->u.x11.s != NULL)
5550 x11_close(c->u.x11.s);
5551 sshfwd_close(c);
32874aea 5552 break;
5553 case CHAN_AGENT:
92f157bd 5554 sshfwd_close(c);
32874aea 5555 break;
d74d141c 5556 case CHAN_SOCKDATA:
92f157bd 5557 if (c->u.pfd.s != NULL)
5558 pfd_close(c->u.pfd.s);
5559 sshfwd_close(c);
bc240b21 5560 break;
32874aea 5561 }
92f157bd 5562 if (c->closes == 0) {
51470298 5563 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5564 ssh2_pkt_adduint32(ssh, c->remoteid);
5565 ssh2_pkt_send(ssh);
92f157bd 5566 }
51470298 5567 del234(ssh->channels, c);
5471d09a 5568 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5569 sfree(c);
5570
5571 /*
5572 * See if that was the last channel left open.
5573 */
51470298 5574 if (count234(ssh->channels) == 0) {
ca2914d1 5575#if 0
5576 /*
5577 * We used to send SSH_MSG_DISCONNECT here,
5578 * because I'd believed that _every_ conforming
5579 * SSH2 connection had to end with a disconnect
5580 * being sent by at least one side; apparently
5581 * I was wrong and it's perfectly OK to
5582 * unceremoniously slam the connection shut
5583 * when you're done, and indeed OpenSSH feels
5584 * this is more polite than sending a
5585 * DISCONNECT. So now we don't.
5586 */
32874aea 5587 logevent("All channels closed. Disconnecting");
51470298 5588 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5589 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5590 ssh2_pkt_addstring(ssh, "All open channels closed");
5591 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5592 ssh2_pkt_send(ssh);
ca2914d1 5593#endif
51470298 5594 ssh->state = SSH_STATE_CLOSED;
32874aea 5595 crReturnV;
5596 }
5597 continue; /* remote sends close; ignore (FIXME) */
51470298 5598 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5599 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5600 struct ssh_channel *c;
51470298 5601 c = find234(ssh->channels, &i, ssh_channelfind);
a6253970 5602 if (!c || c->closes)
5603 continue; /* nonexistent or closing channel */
51470298 5604 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5605 s->try_send = TRUE;
5606 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5607 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5608 struct ssh_channel *c;
51470298 5609 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5610 if (!c)
5611 continue; /* nonexistent channel */
5612 if (c->type != CHAN_SOCKDATA_DORMANT)
5613 continue; /* dunno why they're confirming this */
51470298 5614 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5615 c->type = CHAN_SOCKDATA;
51470298 5616 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5617 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5618 if (c->u.pfd.s)
5619 pfd_confirm(c->u.pfd.s);
5620 if (c->closes) {
5621 /*
5622 * We have a pending close on this channel,
5623 * which we decided on before the server acked
5624 * the channel open. So now we know the
5625 * remoteid, we can close it again.
5626 */
51470298 5627 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5628 ssh2_pkt_adduint32(ssh, c->remoteid);
5629 ssh2_pkt_send(ssh);
4ed34d25 5630 }
51470298 5631 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5632 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5633 struct ssh_channel *c;
51470298 5634 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5635 if (!c)
5636 continue; /* nonexistent channel */
5637 if (c->type != CHAN_SOCKDATA_DORMANT)
5638 continue; /* dunno why they're failing this */
5639
5640 logevent("Forwarded connection refused by server");
5641
5642 pfd_close(c->u.pfd.s);
5643
51470298 5644 del234(ssh->channels, c);
724cface 5645 sfree(c);
51470298 5646 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5647 unsigned localid;
5648 char *type;
5649 int typelen, want_reply;
5650 struct ssh_channel *c;
5651
51470298 5652 localid = ssh2_pkt_getuint32(ssh);
5653 ssh2_pkt_getstring(ssh, &type, &typelen);
5654 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5655
5656 /*
5657 * First, check that the channel exists. Otherwise,
5658 * we can instantly disconnect with a rude message.
5659 */
51470298 5660 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5661 if (!c) {
5662 char buf[80];
5663 sprintf(buf, "Received channel request for nonexistent"
5664 " channel %d", localid);
5665 logevent(buf);
51470298 5666 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5667 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5668 ssh2_pkt_addstring(ssh, buf);
5669 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5670 ssh2_pkt_send(ssh);
247308b5 5671 connection_fatal("%s", buf);
51470298 5672 ssh->state = SSH_STATE_CLOSED;
ebb0a590 5673 crReturnV;
5674 }
5675
5676 /*
d8d6c7e5 5677 * Having got the channel number, we now look at
5678 * the request type string to see if it's something
5679 * we recognise.
ebb0a590 5680 */
d8d6c7e5 5681 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5682 c == ssh->mainchan) {
d8d6c7e5 5683 /* We recognise "exit-status" on the primary channel. */
5684 char buf[100];
51470298 5685 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5686 sprintf(buf, "Server sent command exit status %d",
51470298 5687 ssh->exitcode);
d8d6c7e5 5688 logevent(buf);
5689 if (want_reply) {
51470298 5690 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5691 ssh2_pkt_adduint32(ssh, c->remoteid);
5692 ssh2_pkt_send(ssh);
d8d6c7e5 5693 }
5694 } else {
5695 /*
5696 * This is a channel request we don't know
5697 * about, so we now either ignore the request
5698 * or respond with CHANNEL_FAILURE, depending
5699 * on want_reply.
5700 */
5701 if (want_reply) {
51470298 5702 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5703 ssh2_pkt_adduint32(ssh, c->remoteid);
5704 ssh2_pkt_send(ssh);
d8d6c7e5 5705 }
ebb0a590 5706 }
51470298 5707 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5708 char *type;
5709 int typelen, want_reply;
5710
51470298 5711 ssh2_pkt_getstring(ssh, &type, &typelen);
5712 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5713
5714 /*
5715 * We currently don't support any global requests
5716 * at all, so we either ignore the request or
5717 * respond with REQUEST_FAILURE, depending on
5718 * want_reply.
5719 */
5720 if (want_reply) {
51470298 5721 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5722 ssh2_pkt_send(ssh);
697d4856 5723 }
51470298 5724 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5725 char *type;
5726 int typelen;
b3ebaa28 5727 char *peeraddr;
5728 int peeraddrlen;
5729 int port;
32874aea 5730 char *error = NULL;
5731 struct ssh_channel *c;
bc240b21 5732 unsigned remid, winsize, pktsize;
51470298 5733 ssh2_pkt_getstring(ssh, &type, &typelen);
32874aea 5734 c = smalloc(sizeof(struct ssh_channel));
51470298 5735 c->ssh = ssh;
32874aea 5736
51470298 5737 remid = ssh2_pkt_getuint32(ssh);
5738 winsize = ssh2_pkt_getuint32(ssh);
5739 pktsize = ssh2_pkt_getuint32(ssh);
b3ebaa28 5740 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5741 port = ssh2_pkt_getuint32(ssh);
bc240b21 5742
32874aea 5743 if (typelen == 3 && !memcmp(type, "x11", 3)) {
b3ebaa28 5744 char *addrstr = smalloc(peeraddrlen+1);
5745 memcpy(addrstr, peeraddr, peeraddrlen);
5746 peeraddr[peeraddrlen] = '\0';
5747
51470298 5748 if (!ssh->X11_fwd_enabled)
32874aea 5749 error = "X11 forwarding is not enabled";
86916870 5750 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 5751 ssh->x11auth, addrstr, port,
5752 &ssh->cfg) != NULL) {
32874aea 5753 error = "Unable to open an X11 connection";
5754 } else {
5755 c->type = CHAN_X11;
5756 }
b3ebaa28 5757
5758 sfree(addrstr);
bc240b21 5759 } else if (typelen == 15 &&
5760 !memcmp(type, "forwarded-tcpip", 15)) {
5761 struct ssh_rportfwd pf, *realpf;
5762 char *dummy;
5763 int dummylen;
51470298 5764 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5765 pf.sport = ssh2_pkt_getuint32(ssh);
5766 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 5767 if (realpf == NULL) {
5768 error = "Remote port is not recognised";
5769 } else {
5770 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
e8fa8f62 5771 realpf->dport, c, &ssh->cfg);
57356d63 5772 logeventf(ssh, "Received remote port open request"
5773 " for %s:%d", realpf->dhost, realpf->dport);
bc240b21 5774 if (e != NULL) {
57356d63 5775 logeventf(ssh, "Port open failed: %s", e);
bc240b21 5776 error = "Port open failed";
5777 } else {
5778 logevent("Forwarded port opened successfully");
5779 c->type = CHAN_SOCKDATA;
5780 }
5781 }
32874aea 5782 } else if (typelen == 22 &&
36c2a3e9 5783 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 5784 if (!ssh->agentfwd_enabled)
32874aea 5785 error = "Agent forwarding is not enabled";
36c2a3e9 5786 else {
32874aea 5787 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5788 c->u.a.lensofar = 0;
32874aea 5789 }
5790 } else {
5791 error = "Unsupported channel type requested";
5792 }
5793
bc240b21 5794 c->remoteid = remid;
32874aea 5795 if (error) {
51470298 5796 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5797 ssh2_pkt_adduint32(ssh, c->remoteid);
5798 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5799 ssh2_pkt_addstring(ssh, error);
5800 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5801 ssh2_pkt_send(ssh);
32874aea 5802 sfree(c);
5803 } else {
51470298 5804 c->localid = alloc_channel_id(ssh);
32874aea 5805 c->closes = 0;
5471d09a 5806 c->v.v2.locwindow = OUR_V2_WINSIZE;
5807 c->v.v2.remwindow = winsize;
5808 c->v.v2.remmaxpkt = pktsize;
5809 bufchain_init(&c->v.v2.outbuffer);
51470298 5810 add234(ssh->channels, c);
5811 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5812 ssh2_pkt_adduint32(ssh, c->remoteid);
5813 ssh2_pkt_adduint32(ssh, c->localid);
5814 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5815 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5816 ssh2_pkt_send(ssh);
32874aea 5817 }
7cca0d81 5818 } else {
a8327734 5819 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
32874aea 5820 crReturnV;
7cca0d81 5821 }
5822 } else {
32874aea 5823 /*
5824 * We have spare data. Add it to the channel buffer.
5825 */
d8baa528 5826 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 5827 s->try_send = TRUE;
32874aea 5828 }
51470298 5829 if (s->try_send) {
32874aea 5830 int i;
5831 struct ssh_channel *c;
5832 /*
5833 * Try to send data on all channels if we can.
5834 */
51470298 5835 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 5836 int bufsize;
5837 if (c->closes)
5838 continue; /* don't send on closing channels */
5839 bufsize = ssh2_try_send(c);
5471d09a 5840 if (bufsize == 0) {
5841 switch (c->type) {
5842 case CHAN_MAINSESSION:
5843 /* stdin need not receive an unthrottle
5844 * notification since it will be polled */
5845 break;
5846 case CHAN_X11:
5847 x11_unthrottle(c->u.x11.s);
5848 break;
5849 case CHAN_AGENT:
5850 /* agent sockets are request/response and need no
5851 * buffer management */
5852 break;
5853 case CHAN_SOCKDATA:
5854 pfd_unthrottle(c->u.pfd.s);
5855 break;
5856 }
5857 }
5858 }
7cca0d81 5859 }
e5574168 5860 }
5861
5862 crFinishV;
5863}
5864
5865/*
7cca0d81 5866 * Handle the top-level SSH2 protocol.
5867 */
51470298 5868static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 5869{
51470298 5870 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 5871 return;
51470298 5872 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 5873}
5874
5875/*
8df7a775 5876 * Called to set up the connection.
374330e2 5877 *
5878 * Returns an error message, or NULL on success.
374330e2 5879 */
51470298 5880static char *ssh_init(void *frontend_handle, void **backend_handle,
86916870 5881 Config *cfg,
887035a5 5882 char *host, int port, char **realhost, int nodelay)
32874aea 5883{
fb09bf1c 5884 char *p;
51470298 5885 Ssh ssh;
5886
5887 ssh = smalloc(sizeof(*ssh));
86916870 5888 ssh->cfg = *cfg; /* STRUCTURE COPY */
51470298 5889 ssh->s = NULL;
5890 ssh->cipher = NULL;
371e569c 5891 ssh->v1_cipher_ctx = NULL;
0183b242 5892 ssh->crcda_ctx = NULL;
51470298 5893 ssh->cscipher = NULL;
371e569c 5894 ssh->cs_cipher_ctx = NULL;
51470298 5895 ssh->sccipher = NULL;
371e569c 5896 ssh->sc_cipher_ctx = NULL;
51470298 5897 ssh->csmac = NULL;
a8327734 5898 ssh->cs_mac_ctx = NULL;
51470298 5899 ssh->scmac = NULL;
e0e1a00d 5900 ssh->sc_mac_ctx = NULL;
51470298 5901 ssh->cscomp = NULL;
5366aed8 5902 ssh->cs_comp_ctx = NULL;
51470298 5903 ssh->sccomp = NULL;
5366aed8 5904 ssh->sc_comp_ctx = NULL;
51470298 5905 ssh->kex = NULL;
389aa499 5906 ssh->kex_ctx = NULL;
51470298 5907 ssh->hostkey = NULL;
5908 ssh->exitcode = -1;
5909 ssh->state = SSH_STATE_PREPACKET;
5910 ssh->size_needed = FALSE;
5911 ssh->eof_needed = FALSE;
b9d7bcad 5912 ssh->ldisc = NULL;
a8327734 5913 ssh->logctx = NULL;
51470298 5914 {
5915 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5916 ssh->pktin = ssh->pktout = empty;
5917 }
5918 ssh->deferred_send_data = NULL;
5919 ssh->deferred_len = 0;
5920 ssh->deferred_size = 0;
5921 ssh->fallback_cmd = 0;
5922 ssh->pkt_ctx = 0;
302121de 5923 ssh->x11auth = NULL;
be738459 5924 ssh->v1_compressing = FALSE;
51470298 5925 ssh->v2_outgoing_sequence = 0;
5926 ssh->ssh1_rdpkt_crstate = 0;
5927 ssh->ssh2_rdpkt_crstate = 0;
5928 ssh->do_ssh_init_crstate = 0;
5929 ssh->ssh_gotdata_crstate = 0;
5930 ssh->ssh1_protocol_crstate = 0;
5931 ssh->do_ssh1_login_crstate = 0;
5932 ssh->do_ssh2_transport_crstate = 0;
5933 ssh->do_ssh2_authconn_crstate = 0;
5934 ssh->do_ssh_init_state = NULL;
5935 ssh->do_ssh1_login_state = NULL;
5936 ssh->do_ssh2_transport_state = NULL;
5937 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 5938 ssh->mainchan = NULL;
968d2d92 5939 ssh->throttled_all = 0;
5940 ssh->v1_stdout_throttling = 0;
51470298 5941
5942 *backend_handle = ssh;
32874aea 5943
8f203108 5944#ifdef MSCRYPTOAPI
32874aea 5945 if (crypto_startup() == 0)
8f203108 5946 return "Microsoft high encryption pack not installed!";
5947#endif
374330e2 5948
51470298 5949 ssh->frontend = frontend_handle;
86916870 5950 ssh->term_width = ssh->cfg.width;
5951 ssh->term_height = ssh->cfg.height;
887035a5 5952
fabd1805 5953 ssh->channels = NULL;
5954 ssh->rportfwds = NULL;
5955
51470298 5956 ssh->send_ok = 0;
5957 ssh->editing = 0;
5958 ssh->echoing = 0;
5959 ssh->v1_throttle_count = 0;
5960 ssh->overall_bufsize = 0;
5961 ssh->fallback_cmd = 0;
8df7a775 5962
3648d4c5 5963 ssh->protocol = NULL;
5964
51470298 5965 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 5966 if (p != NULL)
5967 return p;
374330e2 5968
374330e2 5969 return NULL;
5970}
5971
fabd1805 5972static void ssh_free(void *handle)
5973{
5974 Ssh ssh = (Ssh) handle;
5975 struct ssh_channel *c;
5976 struct ssh_rportfwd *pf;
5977
5978 if (ssh->v1_cipher_ctx)
5979 ssh->cipher->free_context(ssh->v1_cipher_ctx);
5980 if (ssh->cs_cipher_ctx)
5981 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5982 if (ssh->sc_cipher_ctx)
5983 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5984 if (ssh->cs_mac_ctx)
5985 ssh->csmac->free_context(ssh->cs_mac_ctx);
5986 if (ssh->sc_mac_ctx)
5987 ssh->scmac->free_context(ssh->sc_mac_ctx);
5988 if (ssh->cs_comp_ctx)
5989 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5990 if (ssh->sc_comp_ctx)
5991 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
5992 if (ssh->kex_ctx)
5993 dh_cleanup(ssh->kex_ctx);
5994 sfree(ssh->savedhost);
5995
5996 if (ssh->channels) {
5997 while ((c = delpos234(ssh->channels, 0)) != NULL) {
5998 switch (c->type) {
5999 case CHAN_X11:
6000 if (c->u.x11.s != NULL)
6001 x11_close(c->u.x11.s);
6002 break;
6003 case CHAN_SOCKDATA:
6004 if (c->u.pfd.s != NULL)
6005 pfd_close(c->u.pfd.s);
6006 break;
6007 }
6008 sfree(c);
6009 }
6010 freetree234(ssh->channels);
6011 }
6012
6013 if (ssh->rportfwds) {
6014 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6015 sfree(pf);
6016 freetree234(ssh->rportfwds);
6017 }
6018 sfree(ssh->deferred_send_data);
6019 if (ssh->x11auth)
6020 x11_free_auth(ssh->x11auth);
6021 sfree(ssh->do_ssh_init_state);
6022 sfree(ssh->do_ssh1_login_state);
6023 sfree(ssh->do_ssh2_transport_state);
6024 sfree(ssh->do_ssh2_authconn_state);
6025
6026 if (ssh->s)
6027 sk_close(ssh->s);
6028 sfree(ssh);
6029}
6030
374330e2 6031/*
86916870 6032 * Reconfigure the SSH backend.
6033 *
6034 * Currently, this function does nothing very useful. In future,
6035 * however, we could do some handy things with it. For example, we
6036 * could make the port forwarding configurer active in the Change
6037 * Settings box, and this routine could close down existing
6038 * forwardings and open up new ones in response to changes.
6039 */
6040static void ssh_reconfig(void *handle, Config *cfg)
6041{
6042 Ssh ssh = (Ssh) handle;
6043 ssh->cfg = *cfg; /* STRUCTURE COPY */
6044}
6045
6046/*
374330e2 6047 * Called to send data down the Telnet connection.
6048 */
51470298 6049static int ssh_send(void *handle, char *buf, int len)
32874aea 6050{
51470298 6051 Ssh ssh = (Ssh) handle;
6052
6053 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6054 return 0;
374330e2 6055
d8baa528 6056 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 6057
51470298 6058 return ssh_sendbuffer(ssh);
5471d09a 6059}
6060
6061/*
6062 * Called to query the current amount of buffered stdin data.
6063 */
51470298 6064static int ssh_sendbuffer(void *handle)
5471d09a 6065{
51470298 6066 Ssh ssh = (Ssh) handle;
5471d09a 6067 int override_value;
6068
51470298 6069 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6070 return 0;
6071
6072 /*
6073 * If the SSH socket itself has backed up, add the total backup
6074 * size on that to any individual buffer on the stdin channel.
6075 */
6076 override_value = 0;
51470298 6077 if (ssh->throttled_all)
6078 override_value = ssh->overall_bufsize;
5471d09a 6079
51470298 6080 if (ssh->version == 1) {
5471d09a 6081 return override_value;
51470298 6082 } else if (ssh->version == 2) {
6083 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 6084 return override_value;
6085 else
51470298 6086 return (override_value +
6087 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 6088 }
6089
6090 return 0;
374330e2 6091}
6092
6093/*
6e48c3fe 6094 * Called to set the size of the window from SSH's POV.
374330e2 6095 */
51470298 6096static void ssh_size(void *handle, int width, int height)
32874aea 6097{
51470298 6098 Ssh ssh = (Ssh) handle;
6099
6100 ssh->term_width = width;
6101 ssh->term_height = height;
f278d6f8 6102
51470298 6103 switch (ssh->state) {
374330e2 6104 case SSH_STATE_BEFORE_SIZE:
3687d221 6105 case SSH_STATE_PREPACKET:
21248260 6106 case SSH_STATE_CLOSED:
374330e2 6107 break; /* do nothing */
6108 case SSH_STATE_INTERMED:
51470298 6109 ssh->size_needed = TRUE; /* buffer for later */
374330e2 6110 break;
6111 case SSH_STATE_SESSION:
86916870 6112 if (!ssh->cfg.nopty) {
51470298 6113 if (ssh->version == 1) {
6114 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6115 PKT_INT, ssh->term_height,
6116 PKT_INT, ssh->term_width,
32874aea 6117 PKT_INT, 0, PKT_INT, 0, PKT_END);
6118 } else {
51470298 6119 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6120 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6121 ssh2_pkt_addstring(ssh, "window-change");
6122 ssh2_pkt_addbool(ssh, 0);
6123 ssh2_pkt_adduint32(ssh, ssh->term_width);
6124 ssh2_pkt_adduint32(ssh, ssh->term_height);
6125 ssh2_pkt_adduint32(ssh, 0);
6126 ssh2_pkt_adduint32(ssh, 0);
6127 ssh2_pkt_send(ssh);
32874aea 6128 }
6129 }
6130 break;
374330e2 6131 }
6132}
6133
6134/*
6abbf9e3 6135 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6136 * can send an EOF and collect resulting output (e.g. `plink
6137 * hostname sort').
374330e2 6138 */
51470298 6139static void ssh_special(void *handle, Telnet_Special code)
32874aea 6140{
51470298 6141 Ssh ssh = (Ssh) handle;
6142
6abbf9e3 6143 if (code == TS_EOF) {
51470298 6144 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6145 /*
6146 * Buffer the EOF in case we are pre-SESSION, so we can
6147 * send it as soon as we reach SESSION.
6148 */
6149 if (code == TS_EOF)
51470298 6150 ssh->eof_needed = TRUE;
32874aea 6151 return;
6152 }
51470298 6153 if (ssh->version == 1) {
6154 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6155 } else {
51470298 6156 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6157 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6158 ssh2_pkt_send(ssh);
32874aea 6159 }
6160 logevent("Sent EOF message");
ec55b220 6161 } else if (code == TS_PING) {
51470298 6162 if (ssh->state == SSH_STATE_CLOSED
6163 || ssh->state == SSH_STATE_PREPACKET) return;
6164 if (ssh->version == 1) {
6165 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6166 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6167 } else {
51470298 6168 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6169 ssh2_pkt_addstring_start(ssh);
6170 ssh2_pkt_send(ssh);
32874aea 6171 }
6abbf9e3 6172 } else {
32874aea 6173 /* do nothing */
6abbf9e3 6174 }
374330e2 6175}
6176
51470298 6177void *new_sock_channel(void *handle, Socket s)
d74d141c 6178{
51470298 6179 Ssh ssh = (Ssh) handle;
d74d141c 6180 struct ssh_channel *c;
6181 c = smalloc(sizeof(struct ssh_channel));
51470298 6182 c->ssh = ssh;
d74d141c 6183
6184 if (c) {
bc240b21 6185 c->remoteid = -1; /* to be set when open confirmed */
51470298 6186 c->localid = alloc_channel_id(ssh);
d74d141c 6187 c->closes = 0;
bc240b21 6188 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6189 c->u.pfd.s = s;
013dd8c0 6190 bufchain_init(&c->v.v2.outbuffer);
51470298 6191 add234(ssh->channels, c);
d74d141c 6192 }
6193 return c;
6194}
6195
5471d09a 6196/*
6197 * This is called when stdout/stderr (the entity to which
6198 * from_backend sends data) manages to clear some backlog.
6199 */
ae9ae89f 6200static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6201{
51470298 6202 Ssh ssh = (Ssh) handle;
6203 if (ssh->version == 1) {
6204 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6205 ssh->v1_stdout_throttling = 0;
6206 ssh1_throttle(ssh, -1);
5471d09a 6207 }
6208 } else {
51470298 6209 if (ssh->mainchan && ssh->mainchan->closes == 0)
6210 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6211 }
6212}
6213
6b78788a 6214void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6215{
6216 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6217 Ssh ssh = c->ssh;
d74d141c 6218
57356d63 6219 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 6220
51470298 6221 if (ssh->version == 1) {
6222 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6223 PKT_INT, c->localid,
6224 PKT_STR, hostname,
6225 PKT_INT, port,
6226 //PKT_STR, <org:orgport>,
6227 PKT_END);
6228 } else {
51470298 6229 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6230 ssh2_pkt_addstring(ssh, "direct-tcpip");
6231 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6232 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6233 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6234 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6235 ssh2_pkt_addstring(ssh, hostname);
6236 ssh2_pkt_adduint32(ssh, port);
bc240b21 6237 /*
6238 * We make up values for the originator data; partly it's
6239 * too much hassle to keep track, and partly I'm not
6240 * convinced the server should be told details like that
6241 * about my local network configuration.
6242 */
51470298 6243 ssh2_pkt_addstring(ssh, "client-side-connection");
6244 ssh2_pkt_adduint32(ssh, 0);
6245 ssh2_pkt_send(ssh);
bc240b21 6246 }
d74d141c 6247}
6248
6249
51470298 6250static Socket ssh_socket(void *handle)
32874aea 6251{
51470298 6252 Ssh ssh = (Ssh) handle;
6253 return ssh->s;
32874aea 6254}
8ccc75b0 6255
51470298 6256static int ssh_sendok(void *handle)
32874aea 6257{
51470298 6258 Ssh ssh = (Ssh) handle;
6259 return ssh->send_ok;
32874aea 6260}
fb09bf1c 6261
51470298 6262static int ssh_ldisc(void *handle, int option)
32874aea 6263{
51470298 6264 Ssh ssh = (Ssh) handle;
32874aea 6265 if (option == LD_ECHO)
51470298 6266 return ssh->echoing;
32874aea 6267 if (option == LD_EDIT)
51470298 6268 return ssh->editing;
0965bee0 6269 return FALSE;
6270}
6271
b9d7bcad 6272static void ssh_provide_ldisc(void *handle, void *ldisc)
6273{
6274 Ssh ssh = (Ssh) handle;
6275 ssh->ldisc = ldisc;
6276}
6277
a8327734 6278static void ssh_provide_logctx(void *handle, void *logctx)
6279{
6280 Ssh ssh = (Ssh) handle;
6281 ssh->logctx = logctx;
6282}
6283
51470298 6284static int ssh_return_exitcode(void *handle)
6285{
6286 Ssh ssh = (Ssh) handle;
6287 return ssh->exitcode;
6288}
6289
6290/*
6291 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6292 * that fails. This variable is the means by which scp.c can reach
6293 * into the SSH code and find out which one it got.
6294 */
6295extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6296{
51470298 6297 Ssh ssh = (Ssh) handle;
6298 return ssh->fallback_cmd;
d8d6c7e5 6299}
6300
374330e2 6301Backend ssh_backend = {
6302 ssh_init,
fabd1805 6303 ssh_free,
86916870 6304 ssh_reconfig,
374330e2 6305 ssh_send,
5471d09a 6306 ssh_sendbuffer,
374330e2 6307 ssh_size,
4017be6d 6308 ssh_special,
8ccc75b0 6309 ssh_socket,
d8d6c7e5 6310 ssh_return_exitcode,
97db3be4 6311 ssh_sendok,
0965bee0 6312 ssh_ldisc,
b9d7bcad 6313 ssh_provide_ldisc,
a8327734 6314 ssh_provide_logctx,
5471d09a 6315 ssh_unthrottle,
97db3be4 6316 22
bc240b21 6317};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator