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[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
dda87a28 166#define BUG_SSH2_PK_SESSIONID 128
bd358db1 167
00db133f 168#define translate(x) if (type == x) return #x
51470298 169#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 170static char *ssh1_pkt_type(int type)
00db133f 171{
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214}
ae9ae89f 215static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 216{
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254}
255#undef translate
256#undef translatec
7d503c31 257
fb09bf1c 258#define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264#define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
7cca0d81 270enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 271
acddebd9 272/*
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
275 * read
276 *
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
278 *
279 * which explains the theory behind these macros.
b624d1e6 280 *
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
285 *
286 * - right-click ssh.c in the FileView
287 * - click Settings
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
acddebd9 291 */
51470298 292#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
293#define crState(t) \
294 struct t *s; \
3d88e64d 295 if (!ssh->t) ssh->t = snew(struct t); \
51470298 296 s = ssh->t;
297#define crFinish(z) } *crLine = 0; return (z); }
298#define crFinishV } *crLine = 0; return; }
374330e2 299#define crReturn(z) \
300 do {\
51470298 301 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 302 } while (0)
303#define crReturnV \
304 do {\
51470298 305 *crLine=__LINE__; return; case __LINE__:;\
374330e2 306 } while (0)
51470298 307#define crStop(z) do{ *crLine = 0; return (z); }while(0)
308#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 309#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 310#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 311
51470298 312typedef struct ssh_tag *Ssh;
313
51470298 314static void ssh2_pkt_init(Ssh, int pkt_type);
315static void ssh2_pkt_addbool(Ssh, unsigned char value);
316static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317static void ssh2_pkt_addstring_start(Ssh);
318static void ssh2_pkt_addstring_str(Ssh, char *data);
319static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320static void ssh2_pkt_addstring(Ssh, char *data);
d8baa528 321static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 322static void ssh2_pkt_addmp(Ssh, Bignum b);
323static int ssh2_pkt_construct(Ssh);
324static void ssh2_pkt_send(Ssh);
839f10db 325static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
326static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
3d63ca2e 327
5471d09a 328/*
329 * Buffer management constants. There are several of these for
330 * various different purposes:
331 *
332 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
333 * on a local data stream before we throttle the whole SSH
334 * connection (in SSH1 only). Throttling the whole connection is
335 * pretty drastic so we set this high in the hope it won't
336 * happen very often.
337 *
338 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
339 * on the SSH connection itself before we defensively throttle
340 * _all_ local data streams. This is pretty drastic too (though
341 * thankfully unlikely in SSH2 since the window mechanism should
342 * ensure that the server never has any need to throttle its end
343 * of the connection), so we set this high as well.
344 *
345 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
346 * channels.
347 */
348
349#define SSH1_BUFFER_LIMIT 32768
350#define SSH_MAX_BACKLOG 32768
351#define OUR_V2_WINSIZE 16384
d74d141c 352
a92dd380 353const static struct ssh_kex *kex_algs[] = {
a92dd380 354 &ssh_diffiehellman_gex,
32874aea 355 &ssh_diffiehellman
356};
e5574168 357
85cc02bb 358const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 359
e0e1a00d 360static void *nullmac_make_context(void)
361{
362 return NULL;
363}
364static void nullmac_free_context(void *handle)
365{
366}
367static void nullmac_key(void *handle, unsigned char *key)
32874aea 368{
369}
e0e1a00d 370static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 371 unsigned long seq)
372{
373}
e0e1a00d 374static int nullmac_verify(void *handle, unsigned char *blk, int len,
375 unsigned long seq)
32874aea 376{
377 return 1;
378}
57476f6b 379const static struct ssh_mac ssh_mac_none = {
e0e1a00d 380 nullmac_make_context, nullmac_free_context, nullmac_key,
381 nullmac_generate, nullmac_verify, "none", 0
e5574168 382};
8b2715b2 383const static struct ssh_mac *macs[] = {
32874aea 384 &ssh_sha1, &ssh_md5, &ssh_mac_none
385};
8b2715b2 386const static struct ssh_mac *buggymacs[] = {
32874aea 387 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
388};
e5574168 389
5366aed8 390static void *ssh_comp_none_init(void)
391{
392 return NULL;
393}
394static void ssh_comp_none_cleanup(void *handle)
32874aea 395{
396}
5366aed8 397static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 398 unsigned char **outblock, int *outlen)
399{
400 return 0;
401}
5366aed8 402static int ssh_comp_none_disable(void *handle)
32874aea 403{
4ba9b64b 404 return 0;
405}
57476f6b 406const static struct ssh_compress ssh_comp_none = {
4ba9b64b 407 "none",
5366aed8 408 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
409 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
410 ssh_comp_none_disable, NULL
e5574168 411};
4ba9b64b 412extern const struct ssh_compress ssh_zlib;
413const static struct ssh_compress *compressions[] = {
32874aea 414 &ssh_zlib, &ssh_comp_none
415};
374330e2 416
32874aea 417enum { /* channel types */
783415f8 418 CHAN_MAINSESSION,
419 CHAN_X11,
420 CHAN_AGENT,
bc240b21 421 CHAN_SOCKDATA,
422 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 423};
424
dacbd0e8 425/*
426 * 2-3-4 tree storing channels.
427 */
428struct ssh_channel {
51470298 429 Ssh ssh; /* pointer back to main context */
d211621f 430 unsigned remoteid, localid;
dacbd0e8 431 int type;
0357890f 432 /*
433 * In SSH1, this value contains four bits:
434 *
435 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
436 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
438 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
439 *
440 * A channel is completely finished with when all four bits are set.
441 */
dacbd0e8 442 int closes;
5471d09a 443 union {
444 struct ssh1_data_channel {
445 int throttling;
446 } v1;
447 struct ssh2_data_channel {
448 bufchain outbuffer;
449 unsigned remwindow, remmaxpkt;
450 unsigned locwindow;
451 } v2;
452 } v;
dacbd0e8 453 union {
32874aea 454 struct ssh_agent_channel {
455 unsigned char *message;
456 unsigned char msglen[4];
457 int lensofar, totallen;
458 } a;
459 struct ssh_x11_channel {
460 Socket s;
461 } x11;
d74d141c 462 struct ssh_pfd_channel {
463 Socket s;
464 } pfd;
dacbd0e8 465 } u;
466};
57476f6b 467
d74d141c 468/*
bc240b21 469 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
470 * 2 use this structure in different ways, reflecting SSH 2's
471 * altogether saner approach to port forwarding.
472 *
473 * In SSH 1, you arrange a remote forwarding by sending the server
474 * the remote port number, and the local destination host:port.
475 * When a connection comes in, the server sends you back that
476 * host:port pair, and you connect to it. This is a ready-made
477 * security hole if you're not on the ball: a malicious server
478 * could send you back _any_ host:port pair, so if you trustingly
479 * connect to the address it gives you then you've just opened the
480 * entire inside of your corporate network just by connecting
481 * through it to a dodgy SSH server. Hence, we must store a list of
482 * host:port pairs we _are_ trying to forward to, and reject a
483 * connection request from the server if it's not in the list.
484 *
485 * In SSH 2, each side of the connection minds its own business and
486 * doesn't send unnecessary information to the other. You arrange a
487 * remote forwarding by sending the server just the remote port
488 * number. When a connection comes in, the server tells you which
489 * of its ports was connected to; and _you_ have to remember what
490 * local host:port pair went with that port number.
491 *
492 * Hence: in SSH 1 this structure stores host:port pairs we intend
493 * to allow connections to, and is indexed by those host:port
494 * pairs. In SSH 2 it stores a mapping from source port to
495 * destination host:port pair, and is indexed by source port.
d74d141c 496 */
497struct ssh_rportfwd {
bc240b21 498 unsigned sport, dport;
499 char dhost[256];
d74d141c 500};
501
57476f6b 502struct Packet {
503 long length;
504 int type;
505 unsigned char *data;
506 unsigned char *body;
507 long savedpos;
508 long maxlen;
509};
510
51470298 511static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
512static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
513static void ssh_size(void *handle, int width, int height);
514static void ssh_special(void *handle, Telnet_Special);
5471d09a 515static int ssh2_try_send(struct ssh_channel *c);
51470298 516static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
517static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 518static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 519static int ssh_sendbuffer(void *handle);
36f94d1f 520static void ssh_do_close(Ssh ssh);
57476f6b 521
51470298 522struct rdpkt1_state_tag {
57476f6b 523 long len, pad, biglen, to_read;
524 unsigned long realcrc, gotcrc;
525 unsigned char *p;
526 int i;
527 int chunk;
51470298 528};
57476f6b 529
51470298 530struct rdpkt2_state_tag {
960e736a 531 long len, pad, payload, packetlen, maclen;
532 int i;
533 int cipherblk;
534 unsigned long incoming_sequence;
51470298 535};
536
537struct ssh_tag {
538 const struct plug_function_table *fn;
539 /* the above field _must_ be first in the structure */
540
541 SHA_State exhash, exhashbase;
542
543 Socket s;
544
b9d7bcad 545 void *ldisc;
a8327734 546 void *logctx;
b9d7bcad 547
51470298 548 unsigned char session_key[32];
549 int v1_compressing;
550 int v1_remote_protoflags;
551 int v1_local_protoflags;
552 int agentfwd_enabled;
553 int X11_fwd_enabled;
554 int remote_bugs;
555 const struct ssh_cipher *cipher;
371e569c 556 void *v1_cipher_ctx;
0183b242 557 void *crcda_ctx;
51470298 558 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 559 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 560 const struct ssh_mac *csmac, *scmac;
e0e1a00d 561 void *cs_mac_ctx, *sc_mac_ctx;
51470298 562 const struct ssh_compress *cscomp, *sccomp;
5366aed8 563 void *cs_comp_ctx, *sc_comp_ctx;
51470298 564 const struct ssh_kex *kex;
565 const struct ssh_signkey *hostkey;
566 unsigned char v2_session_id[20];
27cd7fc2 567 void *kex_ctx;
51470298 568
569 char *savedhost;
570 int savedport;
571 int send_ok;
572 int echoing, editing;
573
574 void *frontend;
575
576 int term_width, term_height;
577
578 tree234 *channels; /* indexed by local id */
579 struct ssh_channel *mainchan; /* primary session channel */
580 int exitcode;
581
582 tree234 *rportfwds;
583
584 enum {
585 SSH_STATE_PREPACKET,
586 SSH_STATE_BEFORE_SIZE,
587 SSH_STATE_INTERMED,
588 SSH_STATE_SESSION,
589 SSH_STATE_CLOSED
590 } state;
591
592 int size_needed, eof_needed;
593
594 struct Packet pktin;
595 struct Packet pktout;
596 unsigned char *deferred_send_data;
597 int deferred_len, deferred_size;
598
599 /*
600 * Gross hack: pscp will try to start SFTP but fall back to
601 * scp1 if that fails. This variable is the means by which
602 * scp.c can reach into the SSH code and find out which one it
603 * got.
604 */
605 int fallback_cmd;
606
607 /*
608 * Used for username and password input.
609 */
610 char *userpass_input_buffer;
611 int userpass_input_buflen;
612 int userpass_input_bufpos;
613 int userpass_input_echo;
614
615 char *portfwd_strptr;
616 int pkt_ctx;
617
302121de 618 void *x11auth;
619
51470298 620 int version;
621 int v1_throttle_count;
622 int overall_bufsize;
623 int throttled_all;
624 int v1_stdout_throttling;
625 int v2_outgoing_sequence;
626
627 int ssh1_rdpkt_crstate;
628 int ssh2_rdpkt_crstate;
629 int do_ssh_init_crstate;
630 int ssh_gotdata_crstate;
631 int ssh1_protocol_crstate;
632 int do_ssh1_login_crstate;
633 int do_ssh2_transport_crstate;
634 int do_ssh2_authconn_crstate;
635
636 void *do_ssh_init_state;
637 void *do_ssh1_login_state;
638 void *do_ssh2_transport_state;
639 void *do_ssh2_authconn_state;
640
641 struct rdpkt1_state_tag rdpkt1_state;
642 struct rdpkt2_state_tag rdpkt2_state;
643
644 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
645 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 646
647 /*
648 * We maintain a full _copy_ of a Config structure here, not
649 * merely a pointer to it. That way, when we're passed a new
650 * one for reconfiguration, we can check the differences and
651 * potentially reconfigure port forwardings etc in mid-session.
652 */
653 Config cfg;
839f10db 654
655 /*
656 * Used to transfer data back from async agent callbacks.
657 */
658 void *agent_response;
659 int agent_response_len;
51470298 660};
960e736a 661
382908ad 662#define logevent(s) logevent(ssh->frontend, s)
a8327734 663
664/* logevent, only printf-formatted. */
cbe2d68f 665static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 666{
667 va_list ap;
57356d63 668 char *buf;
a8327734 669
670 va_start(ap, fmt);
57356d63 671 buf = dupvprintf(fmt, ap);
a8327734 672 va_end(ap);
57356d63 673 logevent(buf);
57356d63 674 sfree(buf);
a8327734 675}
676
6b5cf8b4 677#define bombout(msg) \
678 do { \
679 char *text = dupprintf msg; \
36f94d1f 680 ssh_do_close(ssh); \
6b5cf8b4 681 logevent(text); \
682 connection_fatal(ssh->frontend, "%s", text); \
683 sfree(text); \
684 } while (0)
a8327734 685
32874aea 686static int ssh_channelcmp(void *av, void *bv)
687{
688 struct ssh_channel *a = (struct ssh_channel *) av;
689 struct ssh_channel *b = (struct ssh_channel *) bv;
690 if (a->localid < b->localid)
691 return -1;
692 if (a->localid > b->localid)
693 return +1;
dacbd0e8 694 return 0;
695}
32874aea 696static int ssh_channelfind(void *av, void *bv)
697{
698 unsigned *a = (unsigned *) av;
699 struct ssh_channel *b = (struct ssh_channel *) bv;
700 if (*a < b->localid)
701 return -1;
702 if (*a > b->localid)
703 return +1;
dacbd0e8 704 return 0;
705}
706
bc240b21 707static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 708{
709 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
710 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
711 int i;
bc240b21 712 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 713 return i < 0 ? -1 : +1;
bc240b21 714 if (a->dport > b->dport)
715 return +1;
716 if (a->dport < b->dport)
717 return -1;
718 return 0;
719}
720
721static int ssh_rportcmp_ssh2(void *av, void *bv)
722{
723 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
724 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 725
bc240b21 726 if (a->sport > b->sport)
d74d141c 727 return +1;
bc240b21 728 if (a->sport < b->sport)
729 return -1;
d74d141c 730 return 0;
731}
732
51470298 733static int alloc_channel_id(Ssh ssh)
32874aea 734{
260f3dec 735 const unsigned CHANNEL_NUMBER_OFFSET = 256;
736 unsigned low, high, mid;
d2371c81 737 int tsize;
738 struct ssh_channel *c;
739
740 /*
741 * First-fit allocation of channel numbers: always pick the
742 * lowest unused one. To do this, binary-search using the
743 * counted B-tree to find the largest channel ID which is in a
744 * contiguous sequence from the beginning. (Precisely
745 * everything in that sequence must have ID equal to its tree
746 * index plus CHANNEL_NUMBER_OFFSET.)
747 */
51470298 748 tsize = count234(ssh->channels);
d2371c81 749
32874aea 750 low = -1;
751 high = tsize;
d2371c81 752 while (high - low > 1) {
753 mid = (high + low) / 2;
51470298 754 c = index234(ssh->channels, mid);
d2371c81 755 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
756 low = mid; /* this one is fine */
757 else
758 high = mid; /* this one is past it */
759 }
760 /*
761 * Now low points to either -1, or the tree index of the
762 * largest ID in the initial sequence.
763 */
764 {
765 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 766 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 767 }
768 return low + 1 + CHANNEL_NUMBER_OFFSET;
769}
770
9fab77dc 771static void c_write(Ssh ssh, const char *buf, int len)
32874aea 772{
67779be7 773 if ((flags & FLAG_STDERR)) {
32874aea 774 int i;
775 for (i = 0; i < len; i++)
776 if (buf[i] != '\r')
777 fputc(buf[i], stderr);
fb09bf1c 778 return;
779 }
51470298 780 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 781}
782
9fab77dc 783static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 784{
a209e957 785 int i;
786 for (i = 0; i < len; i++) {
32874aea 787 if (buf[i] == '\n')
51470298 788 c_write(ssh, "\r\n", 2);
32874aea 789 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 790 c_write(ssh, buf + i, 1);
a209e957 791 }
792}
793
9fab77dc 794static void c_write_str(Ssh ssh, const char *buf)
32874aea 795{
51470298 796 c_write(ssh, buf, strlen(buf));
1408a877 797}
798
fb09bf1c 799/*
800 * Collect incoming data in the incoming packet buffer.
e5574168 801 * Decipher and verify the packet when it is completely read.
802 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 803 * Update the *data and *datalen variables.
804 * Return the additional nr of bytes needed, or 0 when
805 * a complete packet is available.
806 */
51470298 807static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 808{
51470298 809 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 810
51470298 811 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 812
32874aea 813 next_packet:
37508af4 814
51470298 815 ssh->pktin.type = 0;
816 ssh->pktin.length = 0;
374330e2 817
57476f6b 818 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 819 while ((*datalen) == 0)
32874aea 820 crReturn(4 - st->i);
57476f6b 821 st->len = (st->len << 8) + **data;
fb09bf1c 822 (*data)++, (*datalen)--;
823 }
374330e2 824
57476f6b 825 st->pad = 8 - (st->len % 8);
826 st->biglen = st->len + st->pad;
51470298 827 ssh->pktin.length = st->len - 5;
fb09bf1c 828
51470298 829 if (ssh->pktin.maxlen < st->biglen) {
830 ssh->pktin.maxlen = st->biglen;
3d88e64d 831 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
832 unsigned char);
fb09bf1c 833 }
374330e2 834
57476f6b 835 st->to_read = st->biglen;
51470298 836 st->p = ssh->pktin.data;
57476f6b 837 while (st->to_read > 0) {
32874aea 838 st->chunk = st->to_read;
fb09bf1c 839 while ((*datalen) == 0)
57476f6b 840 crReturn(st->to_read);
841 if (st->chunk > (*datalen))
842 st->chunk = (*datalen);
843 memcpy(st->p, *data, st->chunk);
844 *data += st->chunk;
845 *datalen -= st->chunk;
846 st->p += st->chunk;
847 st->to_read -= st->chunk;
fb09bf1c 848 }
374330e2 849
0183b242 850 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
851 st->biglen, NULL)) {
6b5cf8b4 852 bombout(("Network attack (CRC compensation) detected!"));
7ffdbc1a 853 crStop(0);
9a3a93a5 854 }
855
51470298 856 if (ssh->cipher)
371e569c 857 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 858
71bedafe 859 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
51470298 860 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 861 if (st->gotcrc != st->realcrc) {
6b5cf8b4 862 bombout(("Incorrect CRC received on packet"));
7ffdbc1a 863 crStop(0);
fb09bf1c 864 }
572f871e 865
51470298 866 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 867
51470298 868 if (ssh->v1_compressing) {
4ba9b64b 869 unsigned char *decompblk;
870 int decomplen;
36b8d9bb 871 if (!zlib_decompress_block(ssh->sc_comp_ctx,
872 ssh->pktin.body - 1, ssh->pktin.length + 1,
873 &decompblk, &decomplen)) {
874 bombout(("Zlib decompression encountered invalid data"));
875 crStop(0);
876 }
4ba9b64b 877
51470298 878 if (ssh->pktin.maxlen < st->pad + decomplen) {
879 ssh->pktin.maxlen = st->pad + decomplen;
3d88e64d 880 ssh->pktin.data = sresize(ssh->pktin.data,
881 ssh->pktin.maxlen + APIEXTRA,
882 unsigned char);
51470298 883 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 884 }
885
51470298 886 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 887 sfree(decompblk);
51470298 888 ssh->pktin.length = decomplen - 1;
4ba9b64b 889 }
890
51470298 891 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 892
a8327734 893 if (ssh->logctx)
894 log_packet(ssh->logctx,
895 PKT_INCOMING, ssh->pktin.type,
896 ssh1_pkt_type(ssh->pktin.type),
897 ssh->pktin.body, ssh->pktin.length);
00db133f 898
51470298 899 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
900 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
901 ssh->pktin.type == SSH1_MSG_DEBUG ||
902 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
903 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
904 long stringlen = GET_32BIT(ssh->pktin.body);
905 if (stringlen + 4 != ssh->pktin.length) {
6b5cf8b4 906 bombout(("Received data packet with bogus string length"));
7ffdbc1a 907 crStop(0);
32874aea 908 }
fb09bf1c 909 }
910
51470298 911 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 912 /* log debug message */
eb4504cc 913 char buf[512];
51470298 914 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 915 strcpy(buf, "Remote debug message: ");
916 if (stringlen > 480)
917 stringlen = 480;
51470298 918 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 919 buf[8 + stringlen] = '\0';
fb09bf1c 920 logevent(buf);
921 goto next_packet;
51470298 922 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 923 /* do nothing */
924 goto next_packet;
925 }
926
51470298 927 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 928 /* log reason code in disconnect message */
929 char buf[256];
51470298 930 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 931 unsigned nowlen;
38c4a8da 932 strcpy(buf, "Remote sent disconnect: ");
933 nowlen = strlen(buf);
32874aea 934 if (msglen > sizeof(buf) - nowlen - 1)
935 msglen = sizeof(buf) - nowlen - 1;
51470298 936 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 937 buf[nowlen + msglen] = '\0';
247308b5 938 /* logevent(buf); (this is now done within the bombout macro) */
6b5cf8b4 939 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
7ffdbc1a 940 crStop(0);
38c4a8da 941 }
942
fb09bf1c 943 crFinish(0);
944}
945
51470298 946static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 947{
51470298 948 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 949
51470298 950 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 951
32874aea 952 next_packet:
51470298 953 ssh->pktin.type = 0;
954 ssh->pktin.length = 0;
955 if (ssh->sccipher)
956 st->cipherblk = ssh->sccipher->blksize;
e5574168 957 else
32874aea 958 st->cipherblk = 8;
960e736a 959 if (st->cipherblk < 8)
32874aea 960 st->cipherblk = 8;
960e736a 961
51470298 962 if (ssh->pktin.maxlen < st->cipherblk) {
963 ssh->pktin.maxlen = st->cipherblk;
3d88e64d 964 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
965 unsigned char);
e5574168 966 }
967
968 /*
969 * Acquire and decrypt the first block of the packet. This will
970 * contain the length and padding details.
971 */
32874aea 972 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 973 while ((*datalen) == 0)
32874aea 974 crReturn(st->cipherblk - st->i);
51470298 975 ssh->pktin.data[st->i] = *(*data)++;
32874aea 976 (*datalen)--;
e5574168 977 }
4252c9cc 978
51470298 979 if (ssh->sccipher)
371e569c 980 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
981 ssh->pktin.data, st->cipherblk);
e5574168 982
983 /*
984 * Now get the length and padding figures.
985 */
51470298 986 st->len = GET_32BIT(ssh->pktin.data);
987 st->pad = ssh->pktin.data[4];
e5574168 988
989 /*
717dc483 990 * _Completely_ silly lengths should be stomped on before they
991 * do us any more damage.
992 */
993 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 994 bombout(("Incoming packet was garbled on decryption"));
7ffdbc1a 995 crStop(0);
717dc483 996 }
997
998 /*
e5574168 999 * This enables us to deduce the payload length.
1000 */
960e736a 1001 st->payload = st->len - st->pad - 1;
e5574168 1002
51470298 1003 ssh->pktin.length = st->payload + 5;
e5574168 1004
1005 /*
1006 * So now we can work out the total packet length.
1007 */
960e736a 1008 st->packetlen = st->len + 4;
51470298 1009 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1010
1011 /*
1012 * Adjust memory allocation if packet is too big.
1013 */
51470298 1014 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1015 ssh->pktin.maxlen = st->packetlen + st->maclen;
3d88e64d 1016 ssh->pktin.data = sresize(ssh->pktin.data,
1017 ssh->pktin.maxlen + APIEXTRA,
1018 unsigned char);
e5574168 1019 }
1020
1021 /*
1022 * Read and decrypt the remainder of the packet.
1023 */
32874aea 1024 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1025 st->i++) {
e5574168 1026 while ((*datalen) == 0)
960e736a 1027 crReturn(st->packetlen + st->maclen - st->i);
51470298 1028 ssh->pktin.data[st->i] = *(*data)++;
32874aea 1029 (*datalen)--;
e5574168 1030 }
1031 /* Decrypt everything _except_ the MAC. */
51470298 1032 if (ssh->sccipher)
371e569c 1033 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1034 ssh->pktin.data + st->cipherblk,
51470298 1035 st->packetlen - st->cipherblk);
e5574168 1036
1037 /*
1038 * Check the MAC.
1039 */
51470298 1040 if (ssh->scmac
e0e1a00d 1041 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1042 st->incoming_sequence)) {
6b5cf8b4 1043 bombout(("Incorrect MAC received on packet"));
7ffdbc1a 1044 crStop(0);
8d5de777 1045 }
32874aea 1046 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1047
4ba9b64b 1048 /*
1049 * Decompress packet payload.
1050 */
1051 {
1052 unsigned char *newpayload;
1053 int newlen;
51470298 1054 if (ssh->sccomp &&
5366aed8 1055 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1056 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1057 &newpayload, &newlen)) {
1058 if (ssh->pktin.maxlen < newlen + 5) {
1059 ssh->pktin.maxlen = newlen + 5;
3d88e64d 1060 ssh->pktin.data = sresize(ssh->pktin.data,
1061 ssh->pktin.maxlen + APIEXTRA,
1062 unsigned char);
4ba9b64b 1063 }
51470298 1064 ssh->pktin.length = 5 + newlen;
1065 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1066 sfree(newpayload);
4ba9b64b 1067 }
1068 }
1069
51470298 1070 ssh->pktin.savedpos = 6;
1071 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1072
a8327734 1073 if (ssh->logctx)
1074 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1075 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1076 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1077
51470298 1078 switch (ssh->pktin.type) {
3d63ca2e 1079 /*
1080 * These packets we must handle instantly.
1081 */
1082 case SSH2_MSG_DISCONNECT:
1083 {
1084 /* log reason code in disconnect message */
57356d63 1085 char *buf;
1086 int nowlen;
51470298 1087 int reason = GET_32BIT(ssh->pktin.data + 6);
1088 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
57356d63 1089
3d63ca2e 1090 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
57356d63 1091 buf = dupprintf("Received disconnect message (%s)",
1092 ssh2_disconnect_reasons[reason]);
3d63ca2e 1093 } else {
57356d63 1094 buf = dupprintf("Received disconnect message (unknown"
1095 " type %d)", reason);
3d63ca2e 1096 }
1097 logevent(buf);
57356d63 1098 sfree(buf);
1099 buf = dupprintf("Disconnection message text: %n%.*s",
33b82b22 1100 &nowlen, msglen, ssh->pktin.data + 14);
3d63ca2e 1101 logevent(buf);
6b5cf8b4 1102 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1103 reason,
1104 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1105 ssh2_disconnect_reasons[reason] : "unknown",
1106 buf+nowlen));
57356d63 1107 sfree(buf);
7ffdbc1a 1108 crStop(0);
3d63ca2e 1109 }
1110 break;
1111 case SSH2_MSG_IGNORE:
1112 goto next_packet;
1113 case SSH2_MSG_DEBUG:
1114 {
1115 /* log the debug message */
1116 char buf[512];
51470298 1117 /* int display = ssh->pktin.body[6]; */
1118 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1119 int prefix;
1120 strcpy(buf, "Remote debug message: ");
1121 prefix = strlen(buf);
51470298 1122 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1123 stringlen = sizeof(buf)-prefix-1;
51470298 1124 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1125 buf[prefix + stringlen] = '\0';
1126 logevent(buf);
38c4a8da 1127 }
3d63ca2e 1128 goto next_packet; /* FIXME: print the debug message */
1129
1130 /*
1131 * These packets we need do nothing about here.
1132 */
1133 case SSH2_MSG_UNIMPLEMENTED:
1134 case SSH2_MSG_SERVICE_REQUEST:
1135 case SSH2_MSG_SERVICE_ACCEPT:
1136 case SSH2_MSG_KEXINIT:
1137 case SSH2_MSG_NEWKEYS:
1138 case SSH2_MSG_KEXDH_INIT:
1139 case SSH2_MSG_KEXDH_REPLY:
1140 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1141 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1142 case SSH2_MSG_KEX_DH_GEX_INIT:
1143 case SSH2_MSG_KEX_DH_GEX_REPLY:
1144 case SSH2_MSG_USERAUTH_REQUEST:
1145 case SSH2_MSG_USERAUTH_FAILURE:
1146 case SSH2_MSG_USERAUTH_SUCCESS:
1147 case SSH2_MSG_USERAUTH_BANNER:
1148 case SSH2_MSG_USERAUTH_PK_OK:
1149 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1150 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1151 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1152 case SSH2_MSG_GLOBAL_REQUEST:
1153 case SSH2_MSG_REQUEST_SUCCESS:
1154 case SSH2_MSG_REQUEST_FAILURE:
1155 case SSH2_MSG_CHANNEL_OPEN:
1156 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1157 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1158 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1159 case SSH2_MSG_CHANNEL_DATA:
1160 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1161 case SSH2_MSG_CHANNEL_EOF:
1162 case SSH2_MSG_CHANNEL_CLOSE:
1163 case SSH2_MSG_CHANNEL_REQUEST:
1164 case SSH2_MSG_CHANNEL_SUCCESS:
1165 case SSH2_MSG_CHANNEL_FAILURE:
1166 break;
1167
1168 /*
1169 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1170 */
1171 default:
51470298 1172 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1173 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1174 ssh2_pkt_send(ssh);
3d63ca2e 1175 break;
38c4a8da 1176 }
1177
e5574168 1178 crFinish(0);
1179}
1180
51470298 1181static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1182{
374330e2 1183 int pad, biglen;
1184
1185 len += 5; /* type and CRC */
32874aea 1186 pad = 8 - (len % 8);
374330e2 1187 biglen = len + pad;
1188
51470298 1189 ssh->pktout.length = len - 5;
1190 if (ssh->pktout.maxlen < biglen) {
1191 ssh->pktout.maxlen = biglen;
8f203108 1192#ifdef MSCRYPTOAPI
fb09bf1c 1193 /* Allocate enough buffer space for extra block
8f203108 1194 * for MS CryptEncrypt() */
3d88e64d 1195 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1196 unsigned char);
8f203108 1197#else
3d88e64d 1198 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1199 unsigned char);
8f203108 1200#endif
374330e2 1201 }
51470298 1202 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1203}
374330e2 1204
51470298 1205static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1206{
51470298 1207 ssh1_pktout_size(ssh, len);
1208 ssh->pktout.type = type;
374330e2 1209}
1210
51470298 1211static int s_wrpkt_prepare(Ssh ssh)
32874aea 1212{
fd7a4aad 1213 int pad, biglen, i;
374330e2 1214 unsigned long crc;
fd7a4aad 1215#ifdef __SC__
1216 /*
1217 * XXX various versions of SC (including 8.8.4) screw up the
1218 * register allocation in this function and use the same register
1219 * (D6) for len and as a temporary, with predictable results. The
1220 * following sledgehammer prevents this.
1221 */
1222 volatile
1223#endif
1224 int len;
374330e2 1225
51470298 1226 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1227
a8327734 1228 if (ssh->logctx)
1229 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1230 ssh1_pkt_type(ssh->pktout.type),
1231 ssh->pktout.body, ssh->pktout.length);
00db133f 1232
51470298 1233 if (ssh->v1_compressing) {
4ba9b64b 1234 unsigned char *compblk;
1235 int complen;
5366aed8 1236 zlib_compress_block(ssh->cs_comp_ctx,
1237 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1238 &compblk, &complen);
51470298 1239 ssh1_pktout_size(ssh, complen - 1);
1240 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1241 sfree(compblk);
4ba9b64b 1242 }
1243
51470298 1244 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1245 pad = 8 - (len % 8);
374330e2 1246 biglen = len + pad;
1247
32874aea 1248 for (i = 0; i < pad; i++)
51470298 1249 ssh->pktout.data[i + 4] = random_byte();
71bedafe 1250 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
51470298 1251 PUT_32BIT(ssh->pktout.data + biglen, crc);
1252 PUT_32BIT(ssh->pktout.data, len);
374330e2 1253
51470298 1254 if (ssh->cipher)
371e569c 1255 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1256
32874aea 1257 return biglen + 4;
39065bed 1258}
1259
51470298 1260static void s_wrpkt(Ssh ssh)
32874aea 1261{
5471d09a 1262 int len, backlog;
51470298 1263 len = s_wrpkt_prepare(ssh);
d8baa528 1264 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1265 if (backlog > SSH_MAX_BACKLOG)
51470298 1266 ssh_throttle_all(ssh, 1, backlog);
39065bed 1267}
1268
51470298 1269static void s_wrpkt_defer(Ssh ssh)
32874aea 1270{
39065bed 1271 int len;
51470298 1272 len = s_wrpkt_prepare(ssh);
1273 if (ssh->deferred_len + len > ssh->deferred_size) {
1274 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1275 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1276 ssh->deferred_size,
1277 unsigned char);
39065bed 1278 }
51470298 1279 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1280 ssh->deferred_len += len;
374330e2 1281}
1282
fb09bf1c 1283/*
39065bed 1284 * Construct a packet with the specified contents.
fb09bf1c 1285 */
51470298 1286static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1287{
fb09bf1c 1288 unsigned char *p, *argp, argchar;
1289 unsigned long argint;
1290 int pktlen, argtype, arglen;
7cca0d81 1291 Bignum bn;
fb09bf1c 1292
1293 pktlen = 0;
39065bed 1294 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1295 switch (argtype) {
1296 case PKT_INT:
39065bed 1297 (void) va_arg(ap1, int);
fb09bf1c 1298 pktlen += 4;
1299 break;
1300 case PKT_CHAR:
1ec39246 1301 (void) va_arg(ap1, int);
fb09bf1c 1302 pktlen++;
1303 break;
1304 case PKT_DATA:
39065bed 1305 (void) va_arg(ap1, unsigned char *);
1306 arglen = va_arg(ap1, int);
fb09bf1c 1307 pktlen += arglen;
1308 break;
1309 case PKT_STR:
39065bed 1310 argp = va_arg(ap1, unsigned char *);
d8baa528 1311 arglen = strlen((char *)argp);
fb09bf1c 1312 pktlen += 4 + arglen;
1313 break;
7cca0d81 1314 case PKT_BIGNUM:
39065bed 1315 bn = va_arg(ap1, Bignum);
32874aea 1316 pktlen += ssh1_bignum_length(bn);
7cca0d81 1317 break;
fb09bf1c 1318 default:
1319 assert(0);
1320 }
1321 }
fb09bf1c 1322
51470298 1323 s_wrpkt_start(ssh, pkttype, pktlen);
1324 p = ssh->pktout.body;
fb09bf1c 1325
39065bed 1326 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1327 switch (argtype) {
1328 case PKT_INT:
39065bed 1329 argint = va_arg(ap2, int);
fb09bf1c 1330 PUT_32BIT(p, argint);
1331 p += 4;
1332 break;
1333 case PKT_CHAR:
1ec39246 1334 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1335 *p = argchar;
1336 p++;
1337 break;
1338 case PKT_DATA:
39065bed 1339 argp = va_arg(ap2, unsigned char *);
1340 arglen = va_arg(ap2, int);
fb09bf1c 1341 memcpy(p, argp, arglen);
1342 p += arglen;
1343 break;
1344 case PKT_STR:
39065bed 1345 argp = va_arg(ap2, unsigned char *);
d8baa528 1346 arglen = strlen((char *)argp);
fb09bf1c 1347 PUT_32BIT(p, arglen);
1348 memcpy(p + 4, argp, arglen);
1349 p += 4 + arglen;
1350 break;
7cca0d81 1351 case PKT_BIGNUM:
39065bed 1352 bn = va_arg(ap2, Bignum);
32874aea 1353 p += ssh1_write_bignum(p, bn);
7cca0d81 1354 break;
fb09bf1c 1355 }
1356 }
39065bed 1357}
fb09bf1c 1358
51470298 1359static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1360{
39065bed 1361 va_list ap1, ap2;
1362 va_start(ap1, pkttype);
1363 va_start(ap2, pkttype);
51470298 1364 construct_packet(ssh, pkttype, ap1, ap2);
1365 s_wrpkt(ssh);
fb09bf1c 1366}
1367
51470298 1368static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1369{
39065bed 1370 va_list ap1, ap2;
1371 va_start(ap1, pkttype);
1372 va_start(ap2, pkttype);
51470298 1373 construct_packet(ssh, pkttype, ap1, ap2);
1374 s_wrpkt_defer(ssh);
39065bed 1375}
1376
32874aea 1377static int ssh_versioncmp(char *a, char *b)
1378{
9697bfd2 1379 char *ae, *be;
1380 unsigned long av, bv;
1381
43aa02a7 1382 av = strtoul(a, &ae, 10);
1383 bv = strtoul(b, &be, 10);
32874aea 1384 if (av != bv)
1385 return (av < bv ? -1 : +1);
1386 if (*ae == '.')
1387 ae++;
1388 if (*be == '.')
1389 be++;
43aa02a7 1390 av = strtoul(ae, &ae, 10);
1391 bv = strtoul(be, &be, 10);
32874aea 1392 if (av != bv)
1393 return (av < bv ? -1 : +1);
9697bfd2 1394 return 0;
1395}
1396
e5574168 1397/*
a92dd380 1398 * Utility routines for putting an SSH-protocol `string' and
1399 * `uint32' into a SHA state.
e5574168 1400 */
1401#include <stdio.h>
32874aea 1402static void sha_string(SHA_State * s, void *str, int len)
1403{
e5574168 1404 unsigned char lenblk[4];
e5574168 1405 PUT_32BIT(lenblk, len);
e5574168 1406 SHA_Bytes(s, lenblk, 4);
e5574168 1407 SHA_Bytes(s, str, len);
1408}
1409
32874aea 1410static void sha_uint32(SHA_State * s, unsigned i)
1411{
a92dd380 1412 unsigned char intblk[4];
1413 PUT_32BIT(intblk, i);
1414 SHA_Bytes(s, intblk, 4);
1415}
1416
7cca0d81 1417/*
1418 * SSH2 packet construction functions.
1419 */
51470298 1420static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1421{
51470298 1422 if (ssh->pktout.maxlen < length) {
1423 ssh->pktout.maxlen = length + 256;
3d88e64d 1424 ssh->pktout.data = sresize(ssh->pktout.data,
1425 ssh->pktout.maxlen + APIEXTRA,
1426 unsigned char);
51470298 1427 if (!ssh->pktout.data)
32874aea 1428 fatalbox("Out of memory");
7cca0d81 1429 }
783415f8 1430}
51470298 1431static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1432{
51470298 1433 ssh->pktout.length += len;
1434 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1435 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1436}
51470298 1437static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1438{
51470298 1439 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1440}
51470298 1441static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1442{
51470298 1443 ssh->pktout.length = 5;
1444 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1445}
51470298 1446static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1447{
51470298 1448 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1449}
51470298 1450static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1451{
7cca0d81 1452 unsigned char x[4];
1453 PUT_32BIT(x, value);
51470298 1454 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1455}
51470298 1456static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1457{
51470298 1458 ssh2_pkt_adduint32(ssh, 0);
1459 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1460}
51470298 1461static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1462{
51470298 1463 ssh2_pkt_adddata(ssh, data, strlen(data));
1464 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1465 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1466}
51470298 1467static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1468{
51470298 1469 ssh2_pkt_adddata(ssh, data, len);
1470 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1471 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1472}
51470298 1473static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1474{
51470298 1475 ssh2_pkt_addstring_start(ssh);
1476 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1477}
d8baa528 1478static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1479{
7cca0d81 1480 unsigned char *p;
32874aea 1481 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1482 p = snewn(n + 1, unsigned char);
7cca0d81 1483 if (!p)
32874aea 1484 fatalbox("out of memory");
7cca0d81 1485 p[0] = 0;
3709bfe9 1486 for (i = 1; i <= n; i++)
32874aea 1487 p[i] = bignum_byte(b, n - i);
7cca0d81 1488 i = 0;
32874aea 1489 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1490 i++;
1491 memmove(p, p + i, n + 1 - i);
1492 *len = n + 1 - i;
7cca0d81 1493 return p;
1494}
51470298 1495static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1496{
7cca0d81 1497 unsigned char *p;
1498 int len;
1499 p = ssh2_mpint_fmt(b, &len);
51470298 1500 ssh2_pkt_addstring_start(ssh);
d8baa528 1501 ssh2_pkt_addstring_data(ssh, (char *)p, len);
dcbde236 1502 sfree(p);
7cca0d81 1503}
b185170a 1504
1505/*
1506 * Construct an SSH2 final-form packet: compress it, encrypt it,
1507 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1508 * ssh->pktout.data. Total length is returned.
b185170a 1509 */
51470298 1510static int ssh2_pkt_construct(Ssh ssh)
32874aea 1511{
7cca0d81 1512 int cipherblk, maclen, padding, i;
7cca0d81 1513
a8327734 1514 if (ssh->logctx)
1515 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1516 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1517 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1518
7cca0d81 1519 /*
4ba9b64b 1520 * Compress packet payload.
1521 */
4ba9b64b 1522 {
1523 unsigned char *newpayload;
1524 int newlen;
51470298 1525 if (ssh->cscomp &&
5366aed8 1526 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1527 ssh->pktout.length - 5,
51470298 1528 &newpayload, &newlen)) {
1529 ssh->pktout.length = 5;
1530 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1531 sfree(newpayload);
4ba9b64b 1532 }
1533 }
1534
1535 /*
7cca0d81 1536 * Add padding. At least four bytes, and must also bring total
1537 * length (minus MAC) up to a multiple of the block size.
1538 */
51470298 1539 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1540 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1541 padding = 4;
32874aea 1542 padding +=
51470298 1543 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1544 maclen = ssh->csmac ? ssh->csmac->len : 0;
1545 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1546 ssh->pktout.data[4] = padding;
7cca0d81 1547 for (i = 0; i < padding; i++)
51470298 1548 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1549 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1550 if (ssh->csmac)
e0e1a00d 1551 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1552 ssh->pktout.length + padding,
51470298 1553 ssh->v2_outgoing_sequence);
1554 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1555
1556 if (ssh->cscipher)
371e569c 1557 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1558 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1559
1560 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1561 return ssh->pktout.length + padding + maclen;
b185170a 1562}
1563
1564/*
1565 * Construct and send an SSH2 packet immediately.
1566 */
51470298 1567static void ssh2_pkt_send(Ssh ssh)
32874aea 1568{
5471d09a 1569 int len;
1570 int backlog;
51470298 1571 len = ssh2_pkt_construct(ssh);
d8baa528 1572 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1573 if (backlog > SSH_MAX_BACKLOG)
51470298 1574 ssh_throttle_all(ssh, 1, backlog);
b185170a 1575}
1576
1577/*
1578 * Construct an SSH2 packet and add it to a deferred data block.
1579 * Useful for sending multiple packets in a single sk_write() call,
1580 * to prevent a traffic-analysing listener from being able to work
1581 * out the length of any particular packet (such as the password
1582 * packet).
1583 *
1584 * Note that because SSH2 sequence-numbers its packets, this can
1585 * NOT be used as an m4-style `defer' allowing packets to be
1586 * constructed in one order and sent in another.
1587 */
51470298 1588static void ssh2_pkt_defer(Ssh ssh)
32874aea 1589{
51470298 1590 int len = ssh2_pkt_construct(ssh);
1591 if (ssh->deferred_len + len > ssh->deferred_size) {
1592 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1593 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1594 ssh->deferred_size,
1595 unsigned char);
b185170a 1596 }
51470298 1597 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1598 ssh->deferred_len += len;
b185170a 1599}
1600
1601/*
1602 * Send the whole deferred data block constructed by
39065bed 1603 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1604 */
51470298 1605static void ssh_pkt_defersend(Ssh ssh)
32874aea 1606{
5471d09a 1607 int backlog;
d8baa528 1608 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1609 ssh->deferred_len);
51470298 1610 ssh->deferred_len = ssh->deferred_size = 0;
1611 sfree(ssh->deferred_send_data);
1612 ssh->deferred_send_data = NULL;
5471d09a 1613 if (backlog > SSH_MAX_BACKLOG)
51470298 1614 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1615}
1616
1617#if 0
32874aea 1618void bndebug(char *string, Bignum b)
1619{
7cca0d81 1620 unsigned char *p;
1621 int i, len;
1622 p = ssh2_mpint_fmt(b, &len);
1623 debug(("%s", string));
1624 for (i = 0; i < len; i++)
32874aea 1625 debug((" %02x", p[i]));
765c4200 1626 debug(("\n"));
dcbde236 1627 sfree(p);
7cca0d81 1628}
1629#endif
1630
32874aea 1631static void sha_mpint(SHA_State * s, Bignum b)
1632{
7cca0d81 1633 unsigned char *p;
1634 int len;
1635 p = ssh2_mpint_fmt(b, &len);
1636 sha_string(s, p, len);
dcbde236 1637 sfree(p);
7cca0d81 1638}
1639
1640/*
1641 * SSH2 packet decode functions.
1642 */
51470298 1643static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1644{
7cca0d81 1645 unsigned long value;
51470298 1646 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1647 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1648 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1649 ssh->pktin.savedpos += 4;
7cca0d81 1650 return value;
1651}
51470298 1652static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1653{
65a22376 1654 unsigned long value;
51470298 1655 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1656 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1657 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1658 ssh->pktin.savedpos++;
65a22376 1659 return value;
1660}
51470298 1661static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1662{
57356d63 1663 int len;
7cca0d81 1664 *p = NULL;
45068b27 1665 *length = 0;
51470298 1666 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1667 return;
57356d63 1668 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1669 if (len < 0)
1670 return;
1671 *length = len;
51470298 1672 ssh->pktin.savedpos += 4;
1673 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1674 return;
d8baa528 1675 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
51470298 1676 ssh->pktin.savedpos += *length;
7cca0d81 1677}
51470298 1678static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1679{
7cca0d81 1680 char *p;
3709bfe9 1681 int length;
7cca0d81 1682 Bignum b;
1683
51470298 1684 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1685 if (!p)
32874aea 1686 return NULL;
8d5de777 1687 if (p[0] & 0x80) {
6b5cf8b4 1688 bombout(("internal error: Can't handle negative mpints"));
32874aea 1689 return NULL;
8d5de777 1690 }
d8baa528 1691 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1692 return b;
1693}
1694
7d503c31 1695/*
1dd353b5 1696 * Helper function to add an SSH2 signature blob to a packet.
1697 * Expects to be shown the public key blob as well as the signature
1698 * blob. Normally works just like ssh2_pkt_addstring, but will
1699 * fiddle with the signature packet if necessary for
1700 * BUG_SSH2_RSA_PADDING.
1701 */
51470298 1702static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1703 void *sigblob_v, int sigblob_len)
1704{
1705 unsigned char *pkblob = (unsigned char *)pkblob_v;
1706 unsigned char *sigblob = (unsigned char *)sigblob_v;
1707
1708 /* dmemdump(pkblob, pkblob_len); */
1709 /* dmemdump(sigblob, sigblob_len); */
1710
1711 /*
1712 * See if this is in fact an ssh-rsa signature and a buggy
1713 * server; otherwise we can just do this the easy way.
1714 */
51470298 1715 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1716 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1717 int pos, len, siglen;
1718
1719 /*
1720 * Find the byte length of the modulus.
1721 */
1722
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1725 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1726 pos += 4; /* find modulus itself */
1727 while (len > 0 && pkblob[pos] == 0)
1728 len--, pos++;
1729 /* debug(("modulus length is %d\n", len)); */
1730
1731 /*
1732 * Now find the signature integer.
1733 */
1734 pos = 4+7; /* skip over "ssh-rsa" */
1735 siglen = GET_32BIT(sigblob+pos);
1736 /* debug(("signature length is %d\n", siglen)); */
1737
1738 if (len != siglen) {
1739 unsigned char newlen[4];
51470298 1740 ssh2_pkt_addstring_start(ssh);
d8baa528 1741 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1dd353b5 1742 /* dmemdump(sigblob, pos); */
1743 pos += 4; /* point to start of actual sig */
1744 PUT_32BIT(newlen, len);
d8baa528 1745 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1dd353b5 1746 /* dmemdump(newlen, 4); */
1747 newlen[0] = 0;
1748 while (len-- > siglen) {
d8baa528 1749 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1dd353b5 1750 /* dmemdump(newlen, 1); */
1751 }
d8baa528 1752 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1dd353b5 1753 /* dmemdump(sigblob+pos, siglen); */
1754 return;
1755 }
1756
1757 /* Otherwise fall through and do it the easy way. */
1758 }
1759
51470298 1760 ssh2_pkt_addstring_start(ssh);
d8baa528 1761 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1dd353b5 1762}
1763
1764/*
7d503c31 1765 * Examine the remote side's version string and compare it against
1766 * a list of known buggy implementations.
1767 */
51470298 1768static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1769{
1770 char *imp; /* pointer to implementation part */
7d503c31 1771 imp = vstring;
1772 imp += strcspn(imp, "-");
bd358db1 1773 if (*imp) imp++;
7d503c31 1774 imp += strcspn(imp, "-");
bd358db1 1775 if (*imp) imp++;
7d503c31 1776
51470298 1777 ssh->remote_bugs = 0;
7d503c31 1778
5ecd7ad0 1779 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1780 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1781 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1782 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 1783 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1784 !strcmp(imp, "OSU_1.4alpha3")))) {
32874aea 1785 /*
1786 * These versions don't support SSH1_MSG_IGNORE, so we have
1787 * to use a different defence against password length
1788 * sniffing.
1789 */
51470298 1790 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1791 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1792 }
1793
5ecd7ad0 1794 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 1796 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 1797 /*
1798 * These versions need a plain password sent; they can't
1799 * handle having a null and a random length of data after
1800 * the password.
1801 */
51470298 1802 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1803 logevent("We believe remote version needs a plain SSH1 password");
1804 }
1805
5ecd7ad0 1806 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1807 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 1808 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1809 /*
1810 * These versions apparently have no clue whatever about
1811 * RSA authentication and will panic and die if they see
1812 * an AUTH_RSA message.
1813 */
51470298 1814 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1815 logevent("We believe remote version can't handle RSA authentication");
1816 }
1817
5ecd7ad0 1818 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 1820 !wc_match("* VShell", imp) &&
831301f6 1821 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1822 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1823 wc_match("2.1 *", imp)))) {
32874aea 1824 /*
1825 * These versions have the HMAC bug.
1826 */
51470298 1827 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1828 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1829 }
1dd353b5 1830
5ecd7ad0 1831 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1832 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 1833 !wc_match("* VShell", imp) &&
2856a1b9 1834 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 1835 /*
1836 * These versions have the key-derivation bug (failing to
1837 * include the literal shared secret in the hashes that
1838 * generate the keys).
1839 */
51470298 1840 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1841 logevent("We believe remote version has SSH2 key-derivation bug");
1842 }
1843
5ecd7ad0 1844 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1845 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 1846 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1847 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 1848 /*
1849 * These versions have the SSH2 RSA padding bug.
1850 */
51470298 1851 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1852 logevent("We believe remote version has SSH2 RSA padding bug");
1853 }
8e975795 1854
dda87a28 1855 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1856 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1857 wc_match("OpenSSH_2.[0-2]*", imp))) {
1858 /*
1859 * These versions have the SSH2 session-ID bug in
1860 * public-key authentication.
1861 */
1862 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1863 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1864 }
1865
5ecd7ad0 1866 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 1867 /*
831301f6 1868 * User specified the SSH2 DH GEX bug.
8e975795 1869 */
51470298 1870 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1871 logevent("We believe remote version has SSH2 DH group exchange bug");
1872 }
7d503c31 1873}
1874
51470298 1875static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1876{
51470298 1877 struct do_ssh_init_state {
1878 int vslen;
1879 char version[10];
1880 char *vstring;
1881 int vstrsize;
1882 int i;
1883 int proto1, proto2;
1884 };
1885 crState(do_ssh_init_state);
374330e2 1886
51470298 1887 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1888
1889 /* Search for the string "SSH-" in the input. */
51470298 1890 s->i = 0;
8df7a775 1891 while (1) {
1892 static const int transS[] = { 1, 2, 2, 1 };
1893 static const int transH[] = { 0, 0, 3, 0 };
1894 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1895 if (c == 'S')
51470298 1896 s->i = transS[s->i];
32874aea 1897 else if (c == 'H')
51470298 1898 s->i = transH[s->i];
32874aea 1899 else if (c == '-')
51470298 1900 s->i = transminus[s->i];
32874aea 1901 else
51470298 1902 s->i = 0;
1903 if (s->i < 0)
8df7a775 1904 break;
1905 crReturn(1); /* get another character */
374330e2 1906 }
8df7a775 1907
51470298 1908 s->vstrsize = 16;
3d88e64d 1909 s->vstring = snewn(s->vstrsize, char);
51470298 1910 strcpy(s->vstring, "SSH-");
1911 s->vslen = 4;
1912 s->i = 0;
374330e2 1913 while (1) {
8df7a775 1914 crReturn(1); /* get another char */
51470298 1915 if (s->vslen >= s->vstrsize - 1) {
1916 s->vstrsize += 16;
3d88e64d 1917 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 1918 }
51470298 1919 s->vstring[s->vslen++] = c;
1920 if (s->i >= 0) {
374330e2 1921 if (c == '-') {
51470298 1922 s->version[s->i] = '\0';
1923 s->i = -1;
1924 } else if (s->i < sizeof(s->version) - 1)
1925 s->version[s->i++] = c;
c4ffc4d0 1926 } else if (c == '\012')
374330e2 1927 break;
1928 }
1929
51470298 1930 ssh->agentfwd_enabled = FALSE;
1931 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1932
51470298 1933 s->vstring[s->vslen] = 0;
1934 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1935 {
1936 char *vlog;
3d88e64d 1937 vlog = snewn(20 + s->vslen, char);
51470298 1938 sprintf(vlog, "Server version: %s", s->vstring);
1939 logevent(vlog);
1940 sfree(vlog);
1941 }
1942 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1943
adf799dd 1944 /*
38d228a2 1945 * Decide which SSH protocol version to support.
adf799dd 1946 */
38d228a2 1947
1948 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1949 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1950 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1951 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1952
86916870 1953 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 1954 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 1955 crStop(0);
38d228a2 1956 }
86916870 1957 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 1958 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 1959 crStop(0);
38d228a2 1960 }
1961
86916870 1962 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1963 /*
38d228a2 1964 * Use v2 protocol.
32874aea 1965 */
1966 char verstring[80], vlog[100];
1967 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1968 SHA_Init(&ssh->exhashbase);
32874aea 1969 /*
1970 * Hash our version string and their version string.
1971 */
51470298 1972 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1973 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1974 sprintf(vlog, "We claim version: %s", verstring);
1975 logevent(vlog);
c4ffc4d0 1976 strcat(verstring, "\012");
32874aea 1977 logevent("Using SSH protocol version 2");
51470298 1978 sk_write(ssh->s, verstring, strlen(verstring));
1979 ssh->protocol = ssh2_protocol;
1980 ssh->version = 2;
1981 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1982 } else {
32874aea 1983 /*
38d228a2 1984 * Use v1 protocol.
32874aea 1985 */
1986 char verstring[80], vlog[100];
1987 sprintf(verstring, "SSH-%s-%s",
51470298 1988 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1989 sshver);
1990 sprintf(vlog, "We claim version: %s", verstring);
1991 logevent(vlog);
c4ffc4d0 1992 strcat(verstring, "\012");
759712a6 1993
32874aea 1994 logevent("Using SSH protocol version 1");
51470298 1995 sk_write(ssh->s, verstring, strlen(verstring));
1996 ssh->protocol = ssh1_protocol;
1997 ssh->version = 1;
1998 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1999 }
125105d1 2000 update_specials_menu(ssh->frontend);
51470298 2001 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 2002
51470298 2003 sfree(s->vstring);
50526e47 2004
8df7a775 2005 crFinish(0);
2006}
2007
51470298 2008static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2009{
51470298 2010 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2011
2012 /*
2013 * To begin with, feed the characters one by one to the
2014 * protocol initialisation / selection function do_ssh_init().
2015 * When that returns 0, we're done with the initial greeting
2016 * exchange and can move on to packet discipline.
2017 */
2018 while (1) {
51470298 2019 int ret; /* need not be kept across crReturn */
8df7a775 2020 if (datalen == 0)
2021 crReturnV; /* more data please */
51470298 2022 ret = do_ssh_init(ssh, *data);
32874aea 2023 data++;
2024 datalen--;
8df7a775 2025 if (ret == 0)
2026 break;
2027 }
2028
2029 /*
2030 * We emerge from that loop when the initial negotiation is
2031 * over and we have selected an s_rdpkt function. Now pass
2032 * everything to s_rdpkt, and then pass the resulting packets
2033 * to the proper protocol handler.
2034 */
2035 if (datalen == 0)
2036 crReturnV;
2037 while (1) {
2038 while (datalen > 0) {
51470298 2039 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2040 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 2041 return;
2042 }
51470298 2043 ssh->protocol(ssh, NULL, 0, 1);
2044 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 2045 return;
2046 }
2047 }
2048 }
2049 crReturnV;
2050 }
2051 crFinishV;
2052}
2053
36f94d1f 2054static void ssh_do_close(Ssh ssh)
32874aea 2055{
36f94d1f 2056 int i;
2057 struct ssh_channel *c;
2058
51470298 2059 ssh->state = SSH_STATE_CLOSED;
2060 if (ssh->s) {
2061 sk_close(ssh->s);
2062 ssh->s = NULL;
f3ab576e 2063 }
36f94d1f 2064 /*
2065 * Now we must shut down any port and X forwardings going
2066 * through this connection.
2067 */
74a98066 2068 if (ssh->channels) {
2069 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2070 switch (c->type) {
2071 case CHAN_X11:
2072 x11_close(c->u.x11.s);
2073 break;
2074 case CHAN_SOCKDATA:
2075 pfd_close(c->u.pfd.s);
2076 break;
2077 }
2078 del234(ssh->channels, c);
2079 if (ssh->version == 2)
2080 bufchain_clear(&c->v.v2.outbuffer);
2081 sfree(c);
36f94d1f 2082 }
36f94d1f 2083 }
2084}
2085
cbe2d68f 2086static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2087 int calling_back)
2088{
2089 Ssh ssh = (Ssh) plug;
2090 ssh_do_close(ssh);
7e78000d 2091 if (error_msg) {
32874aea 2092 /* A socket error has occurred. */
247308b5 2093 logevent(error_msg);
971bcc0a 2094 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2095 } else {
2096 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2097 }
7e78000d 2098 return 0;
2099}
2100
32874aea 2101static int ssh_receive(Plug plug, int urgent, char *data, int len)
2102{
51470298 2103 Ssh ssh = (Ssh) plug;
d8baa528 2104 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2105 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2106 ssh_do_close(ssh);
32874aea 2107 return 0;
3257deae 2108 }
fef97f43 2109 return 1;
374330e2 2110}
2111
5471d09a 2112static void ssh_sent(Plug plug, int bufsize)
2113{
51470298 2114 Ssh ssh = (Ssh) plug;
5471d09a 2115 /*
2116 * If the send backlog on the SSH socket itself clears, we
2117 * should unthrottle the whole world if it was throttled.
2118 */
2119 if (bufsize < SSH_MAX_BACKLOG)
51470298 2120 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2121}
2122
fb09bf1c 2123/*
8df7a775 2124 * Connect to specified host and port.
2125 * Returns an error message, or NULL on success.
6e1ebb76 2126 * Also places the canonical host name into `realhost'. It must be
2127 * freed by the caller.
8df7a775 2128 */
cbe2d68f 2129static const char *connect_to_host(Ssh ssh, char *host, int port,
2130 char **realhost, int nodelay)
8df7a775 2131{
51470298 2132 static const struct plug_function_table fn_table = {
7e78000d 2133 ssh_closing,
5471d09a 2134 ssh_receive,
2135 ssh_sent,
2136 NULL
51470298 2137 };
7e78000d 2138
8df7a775 2139 SockAddr addr;
cbe2d68f 2140 const char *err;
8df7a775 2141
3d88e64d 2142 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2143 if (!ssh->savedhost)
8df7a775 2144 fatalbox("Out of memory");
51470298 2145 strcpy(ssh->savedhost, host);
8df7a775 2146
2147 if (port < 0)
2148 port = 22; /* default ssh port */
51470298 2149 ssh->savedport = port;
8df7a775 2150
2151 /*
2152 * Try to find host.
2153 */
57356d63 2154 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2155 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2156 if ((err = sk_addr_error(addr)) != NULL) {
2157 sk_addr_free(addr);
8df7a775 2158 return err;
170c1e6e 2159 }
8df7a775 2160
8df7a775 2161 /*
2162 * Open socket.
2163 */
3ad9d396 2164 {
57356d63 2165 char addrbuf[100];
3ad9d396 2166 sk_getaddr(addr, addrbuf, 100);
57356d63 2167 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2168 }
51470298 2169 ssh->fn = &fn_table;
e8fa8f62 2170 ssh->s = new_connection(addr, *realhost, port,
2171 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
70e5d0fd 2172 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2173 ssh->s = NULL;
8df7a775 2174 return err;
67c4ba2e 2175 }
8df7a775 2176
8df7a775 2177 return NULL;
2178}
2179
2180/*
5471d09a 2181 * Throttle or unthrottle the SSH connection.
2182 */
51470298 2183static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2184{
51470298 2185 int old_count = ssh->v1_throttle_count;
2186 ssh->v1_throttle_count += adjust;
2187 assert(ssh->v1_throttle_count >= 0);
2188 if (ssh->v1_throttle_count && !old_count) {
2189 sk_set_frozen(ssh->s, 1);
2190 } else if (!ssh->v1_throttle_count && old_count) {
2191 sk_set_frozen(ssh->s, 0);
5471d09a 2192 }
2193}
2194
2195/*
2196 * Throttle or unthrottle _all_ local data streams (for when sends
2197 * on the SSH connection itself back up).
2198 */
51470298 2199static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2200{
2201 int i;
2202 struct ssh_channel *c;
2203
51470298 2204 if (enable == ssh->throttled_all)
5471d09a 2205 return;
51470298 2206 ssh->throttled_all = enable;
2207 ssh->overall_bufsize = bufsize;
2208 if (!ssh->channels)
5471d09a 2209 return;
51470298 2210 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2211 switch (c->type) {
2212 case CHAN_MAINSESSION:
2213 /*
2214 * This is treated separately, outside the switch.
2215 */
2216 break;
2217 case CHAN_X11:
2218 x11_override_throttle(c->u.x11.s, enable);
2219 break;
2220 case CHAN_AGENT:
2221 /* Agent channels require no buffer management. */
2222 break;
2223 case CHAN_SOCKDATA:
36f94d1f 2224 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2225 break;
2226 }
2227 }
2228}
2229
2230/*
51470298 2231 * Username and password input, abstracted off into routines
2232 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2233 */
0405e71f 2234
2235/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2236static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2237{
51470298 2238 ssh->userpass_input_buffer = buffer;
2239 ssh->userpass_input_buflen = buflen;
2240 ssh->userpass_input_bufpos = 0;
2241 ssh->userpass_input_echo = echo;
0405e71f 2242}
2243
2244/*
2245 * Process some terminal data in the course of username/password
2246 * input. Returns >0 for success (line of input returned in
2247 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2248 * for inconclusive (keep waiting for more input please).
2249 */
ae9ae89f 2250static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2251{
2252 char c;
2253
2254 while (inlen--) {
2255 switch (c = *in++) {
2256 case 10:
2257 case 13:
51470298 2258 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2259 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2260 return +1;
2261 break;
2262 case 8:
2263 case 127:
51470298 2264 if (ssh->userpass_input_bufpos > 0) {
2265 if (ssh->userpass_input_echo)
2266 c_write_str(ssh, "\b \b");
2267 ssh->userpass_input_bufpos--;
0405e71f 2268 }
2269 break;
2270 case 21:
2271 case 27:
51470298 2272 while (ssh->userpass_input_bufpos > 0) {
2273 if (ssh->userpass_input_echo)
2274 c_write_str(ssh, "\b \b");
2275 ssh->userpass_input_bufpos--;
0405e71f 2276 }
2277 break;
2278 case 3:
2279 case 4:
2280 return -1;
2281 break;
2282 default:
4692a14a 2283 /*
2284 * This simplistic check for printability is disabled
2285 * when we're doing password input, because some people
2286 * have control characters in their passwords.o
2287 */
2288 if ((!ssh->userpass_input_echo ||
2289 (c >= ' ' && c <= '~') ||
0405e71f 2290 ((unsigned char) c >= 160))
51470298 2291 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2292 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2293 if (ssh->userpass_input_echo)
2294 c_write(ssh, &c, 1);
0405e71f 2295 }
2296 break;
2297 }
2298 }
2299 return 0;
2300}
2301
f11d78f2 2302static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2303{
2304 Ssh ssh = (Ssh) sshv;
2305
2306 ssh->agent_response = reply;
2307 ssh->agent_response_len = replylen;
2308
2309 if (ssh->version == 1)
2310 do_ssh1_login(ssh, NULL, -1, 0);
2311 else
2312 do_ssh2_authconn(ssh, NULL, -1, 0);
2313}
2314
f11d78f2 2315static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2316{
2317 struct ssh_channel *c = (struct ssh_channel *)cv;
2318 Ssh ssh = c->ssh;
2319 void *sentreply = reply;
2320
2321 if (!sentreply) {
2322 /* Fake SSH_AGENT_FAILURE. */
2323 sentreply = "\0\0\0\1\5";
2324 replylen = 5;
2325 }
2326 if (ssh->version == 2) {
2327 ssh2_add_channel_data(c, sentreply, replylen);
2328 ssh2_try_send(c);
2329 } else {
2330 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2331 PKT_INT, c->remoteid,
2332 PKT_INT, replylen,
2333 PKT_DATA, sentreply, replylen,
2334 PKT_END);
2335 }
2336 if (reply)
2337 sfree(reply);
2338}
2339
0405e71f 2340/*
fb09bf1c 2341 * Handle the key exchange and user authentication phases.
2342 */
51470298 2343static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2344{
2d466ffd 2345 int i, j;
374330e2 2346 unsigned char cookie[8];
2347 struct RSAKey servkey, hostkey;
2348 struct MD5Context md5c;
51470298 2349 struct do_ssh1_login_state {
2350 int len;
2351 unsigned char *rsabuf, *keystr1, *keystr2;
2352 unsigned long supported_ciphers_mask, supported_auths_mask;
2353 int tried_publickey, tried_agent;
2354 int tis_auth_refused, ccard_auth_refused;
2355 unsigned char session_id[16];
2356 int cipher_type;
2357 char username[100];
2358 void *publickey_blob;
2359 int publickey_bloblen;
2360 char password[100];
2361 char prompt[200];
2362 int pos;
2363 char c;
2364 int pwpkt_type;
2365 unsigned char request[5], *response, *p;
2366 int responselen;
2367 int keyi, nkeys;
2368 int authed;
2369 struct RSAKey key;
2370 Bignum challenge;
2371 char *commentp;
2372 int commentlen;
2373 };
2374 crState(do_ssh1_login_state);
2375
2376 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2377
32874aea 2378 if (!ispkt)
2379 crWaitUntil(ispkt);
374330e2 2380
51470298 2381 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2382 bombout(("Public key packet not received"));
7ffdbc1a 2383 crStop(0);
8d5de777 2384 }
374330e2 2385
c5e9c988 2386 logevent("Received public keys");
374330e2 2387
51470298 2388 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2389
51470298 2390 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2391 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2392
c5e9c988 2393 /*
1c2a93c4 2394 * Log the host key fingerprint.
c5e9c988 2395 */
c5e9c988 2396 {
2397 char logmsg[80];
1c2a93c4 2398 logevent("Host key fingerprint is:");
c5e9c988 2399 strcpy(logmsg, " ");
32874aea 2400 hostkey.comment = NULL;
2401 rsa_fingerprint(logmsg + strlen(logmsg),
2402 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2403 logevent(logmsg);
2404 }
2405
51470298 2406 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2407 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2408 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2409
51470298 2410 ssh->v1_local_protoflags =
2411 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2412 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2413
c5e9c988 2414 MD5Init(&md5c);
51470298 2415 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2416 MD5Update(&md5c, s->keystr1, servkey.bytes);
2417 MD5Update(&md5c, ssh->pktin.body, 8);
2418 MD5Final(s->session_id, &md5c);
374330e2 2419
32874aea 2420 for (i = 0; i < 32; i++)
51470298 2421 ssh->session_key[i] = random_byte();
374330e2 2422
51470298 2423 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2424
3d88e64d 2425 s->rsabuf = snewn(s->len, unsigned char);
51470298 2426 if (!s->rsabuf)
374330e2 2427 fatalbox("Out of memory");
2428
89ee5268 2429 /*
2430 * Verify the host key.
2431 */
2432 {
32874aea 2433 /*
2434 * First format the key into a string.
2435 */
2436 int len = rsastr_len(&hostkey);
2437 char fingerprint[100];
3d88e64d 2438 char *keystr = snewn(len, char);
32874aea 2439 if (!keystr)
2440 fatalbox("Out of memory");
2441 rsastr_fmt(keystr, &hostkey);
2442 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2443 verify_ssh_host_key(ssh->frontend,
2444 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2445 fingerprint);
2446 sfree(keystr);
2447 }
2448
2449 for (i = 0; i < 32; i++) {
51470298 2450 s->rsabuf[i] = ssh->session_key[i];
374330e2 2451 if (i < 16)
51470298 2452 s->rsabuf[i] ^= s->session_id[i];
374330e2 2453 }
2454
2455 if (hostkey.bytes > servkey.bytes) {
51470298 2456 rsaencrypt(s->rsabuf, 32, &servkey);
2457 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2458 } else {
51470298 2459 rsaencrypt(s->rsabuf, 32, &hostkey);
2460 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2461 }
2462
c5e9c988 2463 logevent("Encrypted session key");
2464
ca20bfcf 2465 {
2466 int cipher_chosen = 0, warn = 0;
2467 char *cipher_string = NULL;
51470298 2468 int i;
ca20bfcf 2469 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2470 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2471 if (next_cipher == CIPHER_WARN) {
2472 /* If/when we choose a cipher, warn about it */
2473 warn = 1;
2474 } else if (next_cipher == CIPHER_AES) {
2475 /* XXX Probably don't need to mention this. */
2476 logevent("AES not supported in SSH1, skipping");
2477 } else {
2478 switch (next_cipher) {
51470298 2479 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2480 cipher_string = "3DES"; break;
51470298 2481 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2482 cipher_string = "Blowfish"; break;
51470298 2483 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2484 cipher_string = "single-DES"; break;
2485 }
51470298 2486 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2487 cipher_chosen = 1;
2488 }
2489 }
2490 if (!cipher_chosen) {
51470298 2491 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2492 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2493 "supporting 3DES encryption"));
2494 else
2495 /* shouldn't happen */
6b5cf8b4 2496 bombout(("No supported ciphers found"));
7ffdbc1a 2497 crStop(0);
a99a05c0 2498 }
ca20bfcf 2499
2500 /* Warn about chosen cipher if necessary. */
2501 if (warn)
a8327734 2502 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2503 }
ca20bfcf 2504
51470298 2505 switch (s->cipher_type) {
32874aea 2506 case SSH_CIPHER_3DES:
2507 logevent("Using 3DES encryption");
2508 break;
2509 case SSH_CIPHER_DES:
2510 logevent("Using single-DES encryption");
2511 break;
2512 case SSH_CIPHER_BLOWFISH:
2513 logevent("Using Blowfish encryption");
2514 break;
c5e9c988 2515 }
bea1ef5f 2516
51470298 2517 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2518 PKT_CHAR, s->cipher_type,
32874aea 2519 PKT_DATA, cookie, 8,
51470298 2520 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2521 PKT_DATA, s->rsabuf, s->len,
2522 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2523
c5e9c988 2524 logevent("Trying to enable encryption...");
374330e2 2525
51470298 2526 sfree(s->rsabuf);
374330e2 2527
51470298 2528 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2529 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2530 &ssh_3des);
371e569c 2531 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2532 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2533 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2534
0183b242 2535 ssh->crcda_ctx = crcda_make_context();
2536 logevent("Installing CRC compensation attack detector");
2537
679539d7 2538 if (servkey.modulus) {
2539 sfree(servkey.modulus);
2540 servkey.modulus = NULL;
2541 }
2542 if (servkey.exponent) {
2543 sfree(servkey.exponent);
2544 servkey.exponent = NULL;
2545 }
2546 if (hostkey.modulus) {
2547 sfree(hostkey.modulus);
2548 hostkey.modulus = NULL;
2549 }
2550 if (hostkey.exponent) {
2551 sfree(hostkey.exponent);
2552 hostkey.exponent = NULL;
2553 }
fb09bf1c 2554 crWaitUntil(ispkt);
374330e2 2555
51470298 2556 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2557 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2558 crStop(0);
8d5de777 2559 }
374330e2 2560
c5e9c988 2561 logevent("Successfully started encryption");
2562
374330e2 2563 fflush(stdout);
2564 {
86916870 2565 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 2566 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2567 if (!ssh_get_line("login as: ",
51470298 2568 s->username, sizeof(s->username), FALSE)) {
32874aea 2569 /*
2570 * get_line failed to get a username.
2571 * Terminate.
2572 */
2573 logevent("No username provided. Abandoning session.");
3bb2f322 2574 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2575 crStop(1);
32874aea 2576 }
2577 } else {
51470298 2578 int ret; /* need not be kept over crReturn */
2579 c_write_str(ssh, "login as: ");
2580 ssh->send_ok = 1;
0405e71f 2581
51470298 2582 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2583 do {
32874aea 2584 crWaitUntil(!ispkt);
51470298 2585 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2586 } while (ret == 0);
2587 if (ret < 0)
2588 cleanup_exit(0);
51470298 2589 c_write_str(ssh, "\r\n");
32874aea 2590 }
2591 } else {
86916870 2592 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2593 s->username[sizeof(s->username)-1] = '\0';
374330e2 2594 }
fb09bf1c 2595
51470298 2596 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2597 {
51470298 2598 char userlog[22 + sizeof(s->username)];
2599 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2600 logevent(userlog);
32874aea 2601 if (flags & FLAG_INTERACTIVE &&
2602 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2603 strcat(userlog, "\r\n");
51470298 2604 c_write_str(ssh, userlog);
3c8e959b 2605 }
c5e9c988 2606 }
374330e2 2607 }
2608
fb09bf1c 2609 crWaitUntil(ispkt);
374330e2 2610
51470298 2611 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2612 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2613 s->tried_publickey = s->tried_agent = 1;
0df73905 2614 } else {
51470298 2615 s->tried_publickey = s->tried_agent = 0;
0df73905 2616 }
51470298 2617 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2618 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2619 if (!filename_is_null(ssh->cfg.keyfile)) {
2620 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2621 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2622 s->publickey_blob = NULL;
396778f1 2623 } else
51470298 2624 s->publickey_blob = NULL;
7cca0d81 2625
51470298 2626 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2627 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2628
51470298 2629 if (agent_exists() && !s->tried_agent) {
32874aea 2630 /*
2631 * Attempt RSA authentication using Pageant.
2632 */
32874aea 2633 void *r;
2634
51470298 2635 s->authed = FALSE;
2636 s->tried_agent = 1;
32874aea 2637 logevent("Pageant is running. Requesting keys.");
2638
2639 /* Request the keys held by the agent. */
51470298 2640 PUT_32BIT(s->request, 1);
2641 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2642 if (!agent_query(s->request, 5, &r, &s->responselen,
2643 ssh_agent_callback, ssh)) {
2644 do {
2645 crReturn(0);
2646 if (ispkt) {
2647 bombout(("Unexpected data from server while waiting"
2648 " for agent response"));
2649 crStop(0);
2650 }
2651 } while (ispkt || inlen > 0);
2652 r = ssh->agent_response;
2653 s->responselen = ssh->agent_response_len;
2654 }
51470298 2655 s->response = (unsigned char *) r;
2656 if (s->response && s->responselen >= 5 &&
2657 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2658 s->p = s->response + 5;
2659 s->nkeys = GET_32BIT(s->p);
2660 s->p += 4;
32874aea 2661 {
2662 char buf[64];
51470298 2663 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2664 logevent(buf);
2665 }
51470298 2666 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2667 {
2668 char buf[64];
51470298 2669 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2670 logevent(buf);
2671 }
51470298 2672 if (s->publickey_blob &&
2673 !memcmp(s->p, s->publickey_blob,
2674 s->publickey_bloblen)) {
396778f1 2675 logevent("This key matches configured key file");
51470298 2676 s->tried_publickey = 1;
396778f1 2677 }
51470298 2678 s->p += 4;
2679 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2680 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2681 s->commentlen = GET_32BIT(s->p);
2682 s->p += 4;
d8baa528 2683 s->commentp = (char *)s->p;
51470298 2684 s->p += s->commentlen;
2685 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2686 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2687 crWaitUntil(ispkt);
51470298 2688 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2689 logevent("Key refused");
2690 continue;
2691 }
2692 logevent("Received RSA challenge");
51470298 2693 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2694 {
2695 char *agentreq, *q, *ret;
2d466ffd 2696 void *vret;
32874aea 2697 int len, retlen;
2698 len = 1 + 4; /* message type, bit count */
51470298 2699 len += ssh1_bignum_length(s->key.exponent);
2700 len += ssh1_bignum_length(s->key.modulus);
2701 len += ssh1_bignum_length(s->challenge);
32874aea 2702 len += 16; /* session id */
2703 len += 4; /* response format */
3d88e64d 2704 agentreq = snewn(4 + len, char);
32874aea 2705 PUT_32BIT(agentreq, len);
2706 q = agentreq + 4;
2707 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2708 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2709 q += 4;
51470298 2710 q += ssh1_write_bignum(q, s->key.exponent);
2711 q += ssh1_write_bignum(q, s->key.modulus);
2712 q += ssh1_write_bignum(q, s->challenge);
2713 memcpy(q, s->session_id, 16);
32874aea 2714 q += 16;
2715 PUT_32BIT(q, 1); /* response format */
839f10db 2716 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2717 ssh_agent_callback, ssh)) {
2718 sfree(agentreq);
2719 do {
2720 crReturn(0);
2721 if (ispkt) {
2722 bombout(("Unexpected data from server"
2723 " while waiting for agent"
2724 " response"));
2725 crStop(0);
2726 }
2727 } while (ispkt || inlen > 0);
2728 vret = ssh->agent_response;
2729 retlen = ssh->agent_response_len;
2730 } else
2731 sfree(agentreq);
2d466ffd 2732 ret = vret;
32874aea 2733 if (ret) {
2734 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2735 logevent("Sending Pageant's response");
51470298 2736 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2737 PKT_DATA, ret + 5, 16,
2738 PKT_END);
2739 sfree(ret);
2740 crWaitUntil(ispkt);
51470298 2741 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2742 logevent
2743 ("Pageant's response accepted");
2744 if (flags & FLAG_VERBOSE) {
51470298 2745 c_write_str(ssh, "Authenticated using"
2746 " RSA key \"");
2747 c_write(ssh, s->commentp,
2748 s->commentlen);
2749 c_write_str(ssh, "\" from agent\r\n");
32874aea 2750 }
51470298 2751 s->authed = TRUE;
32874aea 2752 } else
2753 logevent
2754 ("Pageant's response not accepted");
2755 } else {
2756 logevent
2757 ("Pageant failed to answer challenge");
2758 sfree(ret);
2759 }
2760 } else {
2761 logevent("No reply received from Pageant");
2762 }
2763 }
51470298 2764 freebn(s->key.exponent);
2765 freebn(s->key.modulus);
2766 freebn(s->challenge);
2767 if (s->authed)
32874aea 2768 break;
2769 }
2770 }
51470298 2771 if (s->authed)
32874aea 2772 break;
2773 }
9a30e26b 2774 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 2775 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2776
86916870 2777 if (ssh->cfg.try_tis_auth &&
51470298 2778 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2779 !s->tis_auth_refused) {
2780 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2781 logevent("Requested TIS authentication");
51470298 2782 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2783 crWaitUntil(ispkt);
51470298 2784 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2785 logevent("TIS authentication declined");
2786 if (flags & FLAG_INTERACTIVE)
51470298 2787 c_write_str(ssh, "TIS authentication refused.\r\n");
2788 s->tis_auth_refused = 1;
614a20a0 2789 continue;
32874aea 2790 } else {
51470298 2791 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2792 logevent("Received TIS challenge");
51470298 2793 if (challengelen > sizeof(s->prompt) - 1)
2794 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2795 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2796 /* Prompt heuristic comes from OpenSSH */
51470298 2797 strncpy(s->prompt + challengelen,
2798 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2799 "": "\r\nResponse: ",
51470298 2800 (sizeof s->prompt) - challengelen);
2801 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2802 }
2803 }
86916870 2804 if (ssh->cfg.try_tis_auth &&
51470298 2805 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2806 !s->ccard_auth_refused) {
2807 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2808 logevent("Requested CryptoCard authentication");
51470298 2809 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2810 crWaitUntil(ispkt);
51470298 2811 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2812 logevent("CryptoCard authentication declined");
51470298 2813 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2814 s->ccard_auth_refused = 1;
614a20a0 2815 continue;
32874aea 2816 } else {
51470298 2817 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2818 logevent("Received CryptoCard challenge");
51470298 2819 if (challengelen > sizeof(s->prompt) - 1)
2820 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2821 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2822 strncpy(s->prompt + challengelen,
2823 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2824 "" : "\r\nResponse: ",
51470298 2825 sizeof(s->prompt) - challengelen);
2826 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2827 }
2828 }
51470298 2829 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2830 sprintf(s->prompt, "%.90s@%.90s's password: ",
2831 s->username, ssh->savedhost);
32874aea 2832 }
51470298 2833 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2834 char *comment = NULL;
231ee168 2835 int type;
2836 char msgbuf[256];
32874aea 2837 if (flags & FLAG_VERBOSE)
51470298 2838 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 2839 logeventf(ssh, "Trying public key \"%s\"",
2840 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 2841 type = key_type(&ssh->cfg.keyfile);
231ee168 2842 if (type != SSH_KEYTYPE_SSH1) {
2843 sprintf(msgbuf, "Key is of wrong type (%s)",
2844 key_type_to_str(type));
2845 logevent(msgbuf);
51470298 2846 c_write_str(ssh, msgbuf);
2847 c_write_str(ssh, "\r\n");
2848 s->tried_publickey = 1;
231ee168 2849 continue;
2850 }
9a30e26b 2851 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 2852 if (flags & FLAG_VERBOSE)
51470298 2853 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2854 goto tryauth;
2855 }
51470298 2856 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2857 sfree(comment);
2858 }
a52f067e 2859
614a20a0 2860 /*
2861 * Show password prompt, having first obtained it via a TIS
2862 * or CryptoCard exchange if we're doing TIS or CryptoCard
2863 * authentication.
2864 */
fa17a66e 2865 if (ssh_get_line) {
51470298 2866 if (!ssh_get_line(s->prompt, s->password,
2867 sizeof(s->password), TRUE)) {
32874aea 2868 /*
2869 * get_line failed to get a password (for example
2870 * because one was supplied on the command line
2871 * which has already failed to work). Terminate.
2872 */
51470298 2873 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2874 PKT_STR, "No more passwords available to try",
2875 PKT_END);
247308b5 2876 logevent("Unable to authenticate");
a8327734 2877 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 2878 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2879 crStop(1);
32874aea 2880 }
fb09bf1c 2881 } else {
614a20a0 2882 /* Prompt may have come from server. We've munged it a bit, so
2883 * we know it to be zero-terminated at least once. */
51470298 2884 int ret; /* need not be saved over crReturn */
2885 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2886 s->pos = 0;
0405e71f 2887
51470298 2888 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2889 do {
32874aea 2890 crWaitUntil(!ispkt);
51470298 2891 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2892 } while (ret == 0);
2893 if (ret < 0)
2894 cleanup_exit(0);
51470298 2895 c_write_str(ssh, "\r\n");
32874aea 2896 }
2897
2898 tryauth:
51470298 2899 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2900 /*
2901 * Try public key authentication with the specified
2902 * key file.
2903 */
51470298 2904 s->tried_publickey = 1;
2905
2906 {
222d54dc 2907 const char *error = NULL;
2908 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
2909 &error);
51470298 2910 if (ret == 0) {
2911 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 2912 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 2913 c_write_str(ssh, " (");
2914 c_write_str(ssh, error);
2915 c_write_str(ssh, ").\r\n");
51470298 2916 continue; /* go and try password */
2917 }
2918 if (ret == -1) {
2919 c_write_str(ssh, "Wrong passphrase.\r\n");
2920 s->tried_publickey = 0;
2921 continue; /* try again */
2922 }
32874aea 2923 }
2924
2925 /*
2926 * Send a public key attempt.
2927 */
51470298 2928 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2929 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2930
2931 crWaitUntil(ispkt);
51470298 2932 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2933 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2934 continue; /* go and try password */
2935 }
51470298 2936 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 2937 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 2938 crStop(0);
32874aea 2939 }
32874aea 2940
51470298 2941 {
2942 int i;
2943 unsigned char buffer[32];
2944 Bignum challenge, response;
2945
2946 ssh1_read_bignum(ssh->pktin.body, &challenge);
2947 response = rsadecrypt(challenge, &s->key);
2948 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2949
51470298 2950 for (i = 0; i < 32; i++) {
2951 buffer[i] = bignum_byte(response, 31 - i);
2952 }
2953
2954 MD5Init(&md5c);
2955 MD5Update(&md5c, buffer, 32);
2956 MD5Update(&md5c, s->session_id, 16);
2957 MD5Final(buffer, &md5c);
32874aea 2958
51470298 2959 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2960 PKT_DATA, buffer, 16, PKT_END);
2961
2962 freebn(challenge);
2963 freebn(response);
2964 }
32874aea 2965
2966 crWaitUntil(ispkt);
51470298 2967 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2968 if (flags & FLAG_VERBOSE)
51470298 2969 c_write_str(ssh, "Failed to authenticate with"
2970 " our public key.\r\n");
32874aea 2971 continue; /* go and try password */
51470298 2972 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2973 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 2974 crStop(0);
32874aea 2975 }
2976
2977 break; /* we're through! */
2978 } else {
51470298 2979 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2980 /*
2981 * Defence against traffic analysis: we send a
2982 * whole bunch of packets containing strings of
2983 * different lengths. One of these strings is the
2984 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2985 * The others are all random data in
2986 * SSH1_MSG_IGNORE packets. This way a passive
2987 * listener can't tell which is the password, and
2988 * hence can't deduce the password length.
2989 *
2990 * Anybody with a password length greater than 16
2991 * bytes is going to have enough entropy in their
2992 * password that a listener won't find it _that_
2993 * much help to know how long it is. So what we'll
2994 * do is:
2995 *
2996 * - if password length < 16, we send 15 packets
2997 * containing string lengths 1 through 15
2998 *
2999 * - otherwise, we let N be the nearest multiple
3000 * of 8 below the password length, and send 8
3001 * packets containing string lengths N through
3002 * N+7. This won't obscure the order of
3003 * magnitude of the password length, but it will
3004 * introduce a bit of extra uncertainty.
3005 *
3006 * A few servers (the old 1.2.18 through 1.2.22)
3007 * can't deal with SSH1_MSG_IGNORE. For these
3008 * servers, we need an alternative defence. We make
3009 * use of the fact that the password is interpreted
3010 * as a C string: so we can append a NUL, then some
3011 * random data.
bd358db1 3012 *
3013 * One server (a Cisco one) can deal with neither
3014 * SSH1_MSG_IGNORE _nor_ a padded password string.
3015 * For this server we are left with no defences
3016 * against password length sniffing.
32874aea 3017 */
51470298 3018 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3019 /*
3020 * The server can deal with SSH1_MSG_IGNORE, so
3021 * we can use the primary defence.
3022 */
32874aea 3023 int bottom, top, pwlen, i;
3024 char *randomstr;
3025
51470298 3026 pwlen = strlen(s->password);
32874aea 3027 if (pwlen < 16) {
3028 bottom = 0; /* zero length passwords are OK! :-) */
3029 top = 15;
3030 } else {
3031 bottom = pwlen & ~7;
3032 top = bottom + 7;
3033 }
3034
3035 assert(pwlen >= bottom && pwlen <= top);
3036
3d88e64d 3037 randomstr = snewn(top + 1, char);
32874aea 3038
3039 for (i = bottom; i <= top; i++) {
3040 if (i == pwlen)
51470298 3041 defer_packet(ssh, s->pwpkt_type,
3042 PKT_STR, s->password, PKT_END);
32874aea 3043 else {
3044 for (j = 0; j < i; j++) {
3045 do {
3046 randomstr[j] = random_byte();
3047 } while (randomstr[j] == '\0');
3048 }
3049 randomstr[i] = '\0';
51470298 3050 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3051 PKT_STR, randomstr, PKT_END);
3052 }
3053 }
bd358db1 3054 logevent("Sending password with camouflage packets");
51470298 3055 ssh_pkt_defersend(ssh);
679539d7 3056 sfree(randomstr);
bd358db1 3057 }
51470298 3058 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3059 /*
3060 * The server can't deal with SSH1_MSG_IGNORE
3061 * but can deal with padded passwords, so we
3062 * can use the secondary defence.
3063 */
bd358db1 3064 char string[64];
51470298 3065 char *ss;
bd358db1 3066 int len;
3067
51470298 3068 len = strlen(s->password);
bd358db1 3069 if (len < sizeof(string)) {
51470298 3070 ss = string;
3071 strcpy(string, s->password);
bd358db1 3072 len++; /* cover the zero byte */
3073 while (len < sizeof(string)) {
3074 string[len++] = (char) random_byte();
3075 }
3076 } else {
51470298 3077 ss = s->password;
bd358db1 3078 }
3079 logevent("Sending length-padded password");
51470298 3080 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3081 PKT_DATA, ss, len, PKT_END);
bd358db1 3082 } else {
3083 /*
3084 * The server has _both_
3085 * BUG_CHOKES_ON_SSH1_IGNORE and
3086 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3087 * therefore nothing we can do.
3088 */
3089 int len;
51470298 3090 len = strlen(s->password);
bd358db1 3091 logevent("Sending unpadded password");
51470298 3092 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3093 PKT_DATA, s->password, len, PKT_END);
32874aea 3094 }
3095 } else {
51470298 3096 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 3097 }
3098 }
c5e9c988 3099 logevent("Sent password");
51470298 3100 memset(s->password, 0, strlen(s->password));
fb09bf1c 3101 crWaitUntil(ispkt);
51470298 3102 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3103 if (flags & FLAG_VERBOSE)
51470298 3104 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3105 logevent("Authentication refused");
51470298 3106 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3107 bombout(("Strange packet received, type %d", ssh->pktin.type));
7ffdbc1a 3108 crStop(0);
374330e2 3109 }
3110 }
3111
c5e9c988 3112 logevent("Authentication successful");
3113
fb09bf1c 3114 crFinish(1);
3115}
3116
32874aea 3117void sshfwd_close(struct ssh_channel *c)
3118{
51470298 3119 Ssh ssh = c->ssh;
3120
36f94d1f 3121 if (ssh->state != SSH_STATE_SESSION) {
3122 assert(ssh->state == SSH_STATE_CLOSED);
3123 return;
3124 }
3125
80e48603 3126 if (c && !c->closes) {
4ed34d25 3127 /*
3128 * If the channel's remoteid is -1, we have sent
3129 * CHANNEL_OPEN for this channel, but it hasn't even been
3130 * acknowledged by the server. So we must set a close flag
3131 * on it now, and then when the server acks the channel
3132 * open, we can close it then.
3133 */
36cac739 3134 if (((int)c->remoteid) != -1) {
51470298 3135 if (ssh->version == 1) {
3136 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3137 PKT_END);
3138 } else {
51470298 3139 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3140 ssh2_pkt_adduint32(ssh, c->remoteid);
3141 ssh2_pkt_send(ssh);
4ed34d25 3142 }
32874aea 3143 }
0357890f 3144 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3145 if (c->type == CHAN_X11) {
3146 c->u.x11.s = NULL;
d74d141c 3147 logevent("Forwarded X11 connection terminated");
4ed34d25 3148 } else if (c->type == CHAN_SOCKDATA ||
3149 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3150 c->u.pfd.s = NULL;
3151 logevent("Forwarded port closed");
32874aea 3152 }
3153 }
3154}
3155
5471d09a 3156int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3157{
51470298 3158 Ssh ssh = c->ssh;
3159
36f94d1f 3160 if (ssh->state != SSH_STATE_SESSION) {
3161 assert(ssh->state == SSH_STATE_CLOSED);
3162 return 0;
3163 }
3164
51470298 3165 if (ssh->version == 1) {
3166 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3167 PKT_INT, c->remoteid,
3168 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 3169 /*
3170 * In SSH1 we can return 0 here - implying that forwarded
3171 * connections are never individually throttled - because
3172 * the only circumstance that can cause throttling will be
3173 * the whole SSH connection backing up, in which case
3174 * _everything_ will be throttled as a whole.
3175 */
3176 return 0;
783415f8 3177 } else {
32874aea 3178 ssh2_add_channel_data(c, buf, len);
5471d09a 3179 return ssh2_try_send(c);
3180 }
3181}
3182
3183void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3184{
51470298 3185 Ssh ssh = c->ssh;
3186
36f94d1f 3187 if (ssh->state != SSH_STATE_SESSION) {
3188 assert(ssh->state == SSH_STATE_CLOSED);
3189 return;
3190 }
3191
51470298 3192 if (ssh->version == 1) {
5471d09a 3193 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3194 c->v.v1.throttling = 0;
51470298 3195 ssh1_throttle(ssh, -1);
5471d09a 3196 }
3197 } else {
3198 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3199 }
9c964e85 3200}
3201
51470298 3202static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3203{
51470298 3204 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3205
3206 random_init();
3207
51470298 3208 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3209 crReturnV;
85ee8208 3210 }
51470298 3211 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3212 crReturnV;
fb09bf1c 3213
86916870 3214 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3215 logevent("Requesting agent forwarding");
51470298 3216 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3217 do {
3218 crReturnV;
3219 } while (!ispkt);
51470298 3220 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3221 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3222 bombout(("Protocol confusion"));
7ffdbc1a 3223 crStopV;
51470298 3224 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3225 logevent("Agent forwarding refused");
3226 } else {
3227 logevent("Agent forwarding enabled");
51470298 3228 ssh->agentfwd_enabled = TRUE;
db7d555c 3229 }
dacbd0e8 3230 }
3231
86916870 3232 if (ssh->cfg.x11_forward) {
32874aea 3233 char proto[20], data[64];
3234 logevent("Requesting X11 forwarding");
302121de 3235 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3236 data, sizeof(data), ssh->cfg.x11_auth);
3237 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3238 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3239 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3240 PKT_STR, proto, PKT_STR, data,
86916870 3241 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3242 PKT_END);
32874aea 3243 } else {
51470298 3244 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3245 PKT_STR, proto, PKT_STR, data, PKT_END);
3246 }
3247 do {
3248 crReturnV;
3249 } while (!ispkt);
51470298 3250 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3251 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3252 bombout(("Protocol confusion"));
7ffdbc1a 3253 crStopV;
51470298 3254 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3255 logevent("X11 forwarding refused");
3256 } else {
3257 logevent("X11 forwarding enabled");
51470298 3258 ssh->X11_fwd_enabled = TRUE;
9c964e85 3259 }
3260 }
3261
d74d141c 3262 {
9bf696b1 3263 char type;
d74d141c 3264 int n;
a4fc0d74 3265 int sport,dport,sserv,dserv;
6ee9b735 3266 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3267
51470298 3268 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3269 /* Add port forwardings. */
86916870 3270 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3271 while (*ssh->portfwd_strptr) {
3272 type = *ssh->portfwd_strptr++;
6ee9b735 3273 saddr[0] = '\0';
d74d141c 3274 n = 0;
6ee9b735 3275 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3276 if (*ssh->portfwd_strptr == ':') {
3277 /*
3278 * We've seen a colon in the middle of the
3279 * source port number. This means that
3280 * everything we've seen until now is the
3281 * source _address_, so we'll move it into
3282 * saddr and start sports from the beginning
3283 * again.
3284 */
3285 ssh->portfwd_strptr++;
3286 sports[n] = '\0';
3287 strcpy(saddr, sports);
3288 n = 0;
3289 }
3290 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3291 }
d74d141c 3292 sports[n] = 0;
820ebe3b 3293 if (type != 'D') {
3294 if (*ssh->portfwd_strptr == '\t')
3295 ssh->portfwd_strptr++;
3296 n = 0;
3297 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3298 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3299 }
3300 host[n] = 0;
3301 if (*ssh->portfwd_strptr == ':')
3302 ssh->portfwd_strptr++;
3303 n = 0;
3304 while (*ssh->portfwd_strptr) {
3305 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3306 }
3307 dports[n] = 0;
51470298 3308 ssh->portfwd_strptr++;
820ebe3b 3309 dport = atoi(dports);
3310 dserv = 0;
3311 if (dport == 0) {
3312 dserv = 1;
3313 dport = net_service_lookup(dports);
3314 if (!dport) {
3315 logeventf(ssh, "Service lookup failed for"
3316 " destination port \"%s\"", dports);
3317 }
a4fc0d74 3318 }
820ebe3b 3319 } else {
3320 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3321 dport = dserv = -1;
7d5b0f4d 3322 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3323 }
d74d141c 3324 sport = atoi(sports);
a4fc0d74 3325 sserv = 0;
3326 if (sport == 0) {
3327 sserv = 1;
68a49acb 3328 sport = net_service_lookup(sports);
3329 if (!sport) {
57356d63 3330 logeventf(ssh, "Service lookup failed for source"
3331 " port \"%s\"", sports);
a4fc0d74 3332 }
3333 }
d74d141c 3334 if (sport && dport) {
3335 if (type == 'L') {
6ee9b735 3336 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 3337 sport, ssh, &ssh->cfg);
6ee9b735 3338 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3339 " forwarding to %s:%.*s%.*s%d%.*s",
3340 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3341 (int)(*saddr?1:0), ":",
57356d63 3342 (int)(sserv ? strlen(sports) : 0), sports,
3343 sserv, "(", sport, sserv, ")",
3344 host,
3345 (int)(dserv ? strlen(dports) : 0), dports,
3346 dserv, "(", dport, dserv, ")");
820ebe3b 3347 } else if (type == 'D') {
3348 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3349 sport, ssh, &ssh->cfg);
3350 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3351 " doing SOCKS dynamic forwarding",
3352 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3353 (int)(*saddr?1:0), ":",
3354 (int)(sserv ? strlen(sports) : 0), sports,
3355 sserv, "(", sport, sserv, ")");
d74d141c 3356 } else {
3357 struct ssh_rportfwd *pf;
3d88e64d 3358 pf = snew(struct ssh_rportfwd);
bc240b21 3359 strcpy(pf->dhost, host);
3360 pf->dport = dport;
6ee9b735 3361 if (saddr) {
3362 logeventf(ssh,
3363 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3364 saddr, sport);
3365 }
51470298 3366 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3367 logeventf(ssh,
3368 "Duplicate remote port forwarding to %s:%d",
3369 host, dport);
bc240b21 3370 sfree(pf);
d74d141c 3371 } else {
57356d63 3372 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3373 " forward to %s:%.*s%.*s%d%.*s",
3374 (int)(sserv ? strlen(sports) : 0), sports,
3375 sserv, "(", sport, sserv, ")",
3376 host,
3377 (int)(dserv ? strlen(dports) : 0), dports,
3378 dserv, "(", dport, dserv, ")");
51470298 3379 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3380 PKT_INT, sport,
3381 PKT_STR, host,
3382 PKT_INT, dport,
3383 PKT_END);
9bf696b1 3384 do {
3385 crReturnV;
3386 } while (!ispkt);
51470298 3387 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3388 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3389 bombout(("Protocol confusion"));
7ffdbc1a 3390 crStopV;
51470298 3391 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3392 c_write_str(ssh, "Server refused port"
3393 " forwarding\r\n");
9bf696b1 3394 }
3395 logevent("Remote port forwarding enabled");
d74d141c 3396 }
3397 }
3398 }
3399 }
3400 }
3401
86916870 3402 if (!ssh->cfg.nopty) {
51470298 3403 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3404 PKT_STR, ssh->cfg.termtype,
51470298 3405 PKT_INT, ssh->term_height,
3406 PKT_INT, ssh->term_width,
32874aea 3407 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3408 ssh->state = SSH_STATE_INTERMED;
32874aea 3409 do {
3410 crReturnV;
3411 } while (!ispkt);
51470298 3412 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3413 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3414 bombout(("Protocol confusion"));
7ffdbc1a 3415 crStopV;
51470298 3416 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3417 c_write_str(ssh, "Server refused to allocate pty\r\n");
3418 ssh->editing = ssh->echoing = 1;
32874aea 3419 }
c5e9c988 3420 logevent("Allocated pty");
0965bee0 3421 } else {
51470298 3422 ssh->editing = ssh->echoing = 1;
374330e2 3423 }
3424
86916870 3425 if (ssh->cfg.compression) {
51470298 3426 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3427 do {
3428 crReturnV;
3429 } while (!ispkt);
51470298 3430 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3431 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3432 bombout(("Protocol confusion"));
7ffdbc1a 3433 crStopV;
51470298 3434 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3435 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3436 }
4ba9b64b 3437 logevent("Started compression");
51470298 3438 ssh->v1_compressing = TRUE;
5366aed8 3439 ssh->cs_comp_ctx = zlib_compress_init();
3440 logevent("Initialised zlib (RFC1950) compression");
3441 ssh->sc_comp_ctx = zlib_decompress_init();
3442 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3443 }
3444
fd5e5847 3445 /*
3446 * Start the shell or command.
3447 *
3448 * Special case: if the first-choice command is an SSH2
3449 * subsystem (hence not usable here) and the second choice
3450 * exists, we fall straight back to that.
3451 */
3452 {
86916870 3453 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3454
86916870 3455 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3456 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3457 ssh->fallback_cmd = TRUE;
fd5e5847 3458 }
3459 if (*cmd)
51470298 3460 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3461 else
51470298 3462 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3463 logevent("Started session");
3464 }
374330e2 3465
51470298 3466 ssh->state = SSH_STATE_SESSION;
3467 if (ssh->size_needed)
3468 ssh_size(ssh, ssh->term_width, ssh->term_height);
3469 if (ssh->eof_needed)
3470 ssh_special(ssh, TS_EOF);
374330e2 3471
b9d7bcad 3472 if (ssh->ldisc)
3473 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3474 ssh->send_ok = 1;
3475 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3476 while (1) {
3477 crReturnV;
3478 if (ispkt) {
51470298 3479 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3480 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3481 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3482 int bufsize =
51470298 3483 from_backend(ssh->frontend,
3484 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
d8baa528 3485 (char *)(ssh->pktin.body) + 4, len);
51470298 3486 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3487 ssh->v1_stdout_throttling = 1;
3488 ssh1_throttle(ssh, +1);
5471d09a 3489 }
51470298 3490 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3bb2f322 3491 ssh_closing((Plug)ssh, NULL, 0, 0);
c5e9c988 3492 logevent("Received disconnect request");
7ffdbc1a 3493 crStopV;
51470298 3494 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3495 /* Remote side is trying to open a channel to talk to our
3496 * X-Server. Give them back a local channel number. */
3497 struct ssh_channel *c;
9c964e85 3498
3499 logevent("Received X11 connect request");
3500 /* Refuse if X11 forwarding is disabled. */
51470298 3501 if (!ssh->X11_fwd_enabled) {
3502 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3503 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3504 logevent("Rejected X11 connect request");
3505 } else {
3d88e64d 3506 c = snew(struct ssh_channel);
51470298 3507 c->ssh = ssh;
9c964e85 3508
86916870 3509 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3510 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
32874aea 3511 logevent("opening X11 forward connection failed");
3512 sfree(c);
51470298 3513 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3514 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3515 PKT_END);
9c964e85 3516 } else {
32874aea 3517 logevent
3518 ("opening X11 forward connection succeeded");
51470298 3519 c->remoteid = GET_32BIT(ssh->pktin.body);
3520 c->localid = alloc_channel_id(ssh);
32874aea 3521 c->closes = 0;
5471d09a 3522 c->v.v1.throttling = 0;
32874aea 3523 c->type = CHAN_X11; /* identify channel type */
51470298 3524 add234(ssh->channels, c);
3525 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3526 PKT_INT, c->remoteid, PKT_INT,
3527 c->localid, PKT_END);
3528 logevent("Opened X11 forward channel");
9c964e85 3529 }
3530 }
51470298 3531 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3532 /* Remote side is trying to open a channel to talk to our
3533 * agent. Give them back a local channel number. */
3534 struct ssh_channel *c;
db7d555c 3535
3536 /* Refuse if agent forwarding is disabled. */
51470298 3537 if (!ssh->agentfwd_enabled) {
3538 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3539 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3540 } else {
3d88e64d 3541 c = snew(struct ssh_channel);
51470298 3542 c->ssh = ssh;
3543 c->remoteid = GET_32BIT(ssh->pktin.body);
3544 c->localid = alloc_channel_id(ssh);
db7d555c 3545 c->closes = 0;
5471d09a 3546 c->v.v1.throttling = 0;
32874aea 3547 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3548 c->u.a.lensofar = 0;
51470298 3549 add234(ssh->channels, c);
3550 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3551 PKT_INT, c->remoteid, PKT_INT, c->localid,
3552 PKT_END);
3553 }
51470298 3554 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3555 /* Remote side is trying to open a channel to talk to a
3556 * forwarded port. Give them back a local channel number. */
3557 struct ssh_channel *c;
3558 struct ssh_rportfwd pf;
3559 int hostsize, port;
3560 char host[256], buf[1024];
cbe2d68f 3561 char *p, *h;
3562 const char *e;
3d88e64d 3563 c = snew(struct ssh_channel);
51470298 3564 c->ssh = ssh;
d74d141c 3565
51470298 3566 hostsize = GET_32BIT(ssh->pktin.body+4);
d8baa528 3567 for (h = host, p = (char *)(ssh->pktin.body+8);
3568 hostsize != 0; hostsize--) {
d74d141c 3569 if (h+1 < host+sizeof(host))
3570 *h++ = *p;
95bc8819 3571 p++;
d74d141c 3572 }
3573 *h = 0;
3574 port = GET_32BIT(p);
3575
bc240b21 3576 strcpy(pf.dhost, host);
3577 pf.dport = port;
d74d141c 3578
51470298 3579 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3580 sprintf(buf, "Rejected remote port open request for %s:%d",
3581 host, port);
3582 logevent(buf);
51470298 3583 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3584 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3585 } else {
3586 sprintf(buf, "Received remote port open request for %s:%d",
3587 host, port);
3588 logevent(buf);
e8fa8f62 3589 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
d74d141c 3590 if (e != NULL) {
3591 char buf[256];
3592 sprintf(buf, "Port open failed: %s", e);
3593 logevent(buf);
3594 sfree(c);
51470298 3595 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3596 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3597 PKT_END);
3598 } else {
51470298 3599 c->remoteid = GET_32BIT(ssh->pktin.body);
3600 c->localid = alloc_channel_id(ssh);
d74d141c 3601 c->closes = 0;
5471d09a 3602 c->v.v1.throttling = 0;
d74d141c 3603 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3604 add234(ssh->channels, c);
3605 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3606 PKT_INT, c->remoteid, PKT_INT,
3607 c->localid, PKT_END);
3608 logevent("Forwarded port opened successfully");
3609 }
3610 }
3611
51470298 3612 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3613 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3614 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3615 struct ssh_channel *c;
3616
51470298 3617 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3618 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3619 c->remoteid = localid;
3620 c->type = CHAN_SOCKDATA;
7781f316 3621 c->v.v1.throttling = 0;
bc240b21 3622 pfd_confirm(c->u.pfd.s);
3623 }
d74d141c 3624
4ed34d25 3625 if (c && c->closes) {
3626 /*
3627 * We have a pending close on this channel,
3628 * which we decided on before the server acked
3629 * the channel open. So now we know the
3630 * remoteid, we can close it again.
3631 */
51470298 3632 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3633 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3634 }
3635
51470298 3636 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3637 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
724cface 3638 struct ssh_channel *c;
3639
51470298 3640 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3641 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3642 logevent("Forwarded connection refused by server");
3643 pfd_close(c->u.pfd.s);
51470298 3644 del234(ssh->channels, c);
724cface 3645 sfree(c);
3646 }
3647
51470298 3648 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3649 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3650 /* Remote side closes a channel. */
51470298 3651 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3652 struct ssh_channel *c;
51470298 3653 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3654 if (c && ((int)c->remoteid) != -1) {
32874aea 3655 int closetype;
3656 closetype =
51470298 3657 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3658
783415f8 3659 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3660 logevent("Forwarded X11 connection terminated");
9c964e85 3661 assert(c->u.x11.s != NULL);
3662 x11_close(c->u.x11.s);
3663 c->u.x11.s = NULL;
3664 }
d74d141c 3665 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3666 logevent("Forwarded port closed");
3667 assert(c->u.pfd.s != NULL);
3668 pfd_close(c->u.pfd.s);
3669 c->u.pfd.s = NULL;
3670 }
0357890f 3671
3672 c->closes |= (closetype << 2); /* seen this message */
3673 if (!(c->closes & closetype)) {
51470298 3674 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3675 PKT_END);
3676 c->closes |= closetype; /* sent it too */
3677 }
3678
3679 if (c->closes == 15) {
51470298 3680 del234(ssh->channels, c);
32874aea 3681 sfree(c);
3682 }
d0d844c1 3683 } else {
6b5cf8b4 3684 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3685 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3686 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3687 i));
7ffdbc1a 3688 crStopV;
32874aea 3689 }
51470298 3690 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3691 /* Data sent down one of our channels. */
51470298 3692 int i = GET_32BIT(ssh->pktin.body);
3693 int len = GET_32BIT(ssh->pktin.body + 4);
3694 unsigned char *p = ssh->pktin.body + 8;
32874aea 3695 struct ssh_channel *c;
51470298 3696 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3697 if (c) {
7ffdbc1a 3698 int bufsize = 0;
32874aea 3699 switch (c->type) {
3700 case CHAN_X11:
d8baa528 3701 bufsize = x11_send(c->u.x11.s, (char *)p, len);
9c964e85 3702 break;
d74d141c 3703 case CHAN_SOCKDATA:
d8baa528 3704 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
bc240b21 3705 break;
32874aea 3706 case CHAN_AGENT:
3707 /* Data for an agent message. Buffer it. */
3708 while (len > 0) {
3709 if (c->u.a.lensofar < 4) {
3710 int l = min(4 - c->u.a.lensofar, len);
3711 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3712 l);
3713 p += l;
3714 len -= l;
3715 c->u.a.lensofar += l;
3716 }
3717 if (c->u.a.lensofar == 4) {
3718 c->u.a.totallen =
3719 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 3720 c->u.a.message = snewn(c->u.a.totallen,
3721 unsigned char);
32874aea 3722 memcpy(c->u.a.message, c->u.a.msglen, 4);
3723 }
3724 if (c->u.a.lensofar >= 4 && len > 0) {
3725 int l =
3726 min(c->u.a.totallen - c->u.a.lensofar,
3727 len);
3728 memcpy(c->u.a.message + c->u.a.lensofar, p,
3729 l);
3730 p += l;
3731 len -= l;
3732 c->u.a.lensofar += l;
3733 }
3734 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 3735 void *reply;
32874aea 3736 int replylen;
839f10db 3737 if (agent_query(c->u.a.message,
3738 c->u.a.totallen,
3739 &reply, &replylen,
3740 ssh_agentf_callback, c))
3741 ssh_agentf_callback(c, reply, replylen);
32874aea 3742 sfree(c->u.a.message);
3743 c->u.a.lensofar = 0;
3744 }
3745 }
5471d09a 3746 bufsize = 0; /* agent channels never back up */
32874aea 3747 break;
3748 }
90347b95 3749 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3750 c->v.v1.throttling = 1;
51470298 3751 ssh1_throttle(ssh, +1);
5471d09a 3752 }
32874aea 3753 }
51470298 3754 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3755 /* may be from EXEC_SHELL on some servers */
51470298 3756 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3757 /* may be from EXEC_SHELL on some servers
374330e2 3758 * if no pty is available or in other odd cases. Ignore */
51470298 3759 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3760 char buf[100];
51470298 3761 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3762 sprintf(buf, "Server sent command exit status %d",
51470298 3763 ssh->exitcode);
d8d6c7e5 3764 logevent(buf);
51470298 3765 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3766 /*
3767 * In case `helpful' firewalls or proxies tack
3768 * extra human-readable text on the end of the
3769 * session which we might mistake for another
3770 * encrypted packet, we close the session once
3771 * we've sent EXIT_CONFIRMATION.
3772 */
3bb2f322 3773 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3774 crStopV;
374330e2 3775 } else {
6b5cf8b4 3776 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 3777 crStopV;
374330e2 3778 }
3779 } else {
8df7a775 3780 while (inlen > 0) {
3781 int len = min(inlen, 512);
51470298 3782 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3783 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3784 in += len;
3785 inlen -= len;
3786 }
374330e2 3787 }
3788 }
3789
3790 crFinishV;
3791}
3792
3793/*
e5574168 3794 * Utility routine for decoding comma-separated strings in KEXINIT.
3795 */
32874aea 3796static int in_commasep_string(char *needle, char *haystack, int haylen)
3797{
57356d63 3798 int needlen;
3799 if (!needle || !haystack) /* protect against null pointers */
3800 return 0;
3801 needlen = strlen(needle);
e5574168 3802 while (1) {
32874aea 3803 /*
3804 * Is it at the start of the string?
3805 */
3806 if (haylen >= needlen && /* haystack is long enough */
3807 !memcmp(needle, haystack, needlen) && /* initial match */
3808 (haylen == needlen || haystack[needlen] == ',')
3809 /* either , or EOS follows */
3810 )
3811 return 1;
3812 /*
3813 * If not, search for the next comma and resume after that.
3814 * If no comma found, terminate.
3815 */
3816 while (haylen > 0 && *haystack != ',')
3817 haylen--, haystack++;
3818 if (haylen == 0)
3819 return 0;
3820 haylen--, haystack++; /* skip over comma itself */
e5574168 3821 }
3822}
3823
3824/*
d39f364a 3825 * SSH2 key creation method.
3826 */
d8baa528 3827static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3828 unsigned char *sessid, char chr,
3829 unsigned char *keyspace)
32874aea 3830{
d39f364a 3831 SHA_State s;
3832 /* First 20 bytes. */
3833 SHA_Init(&s);
51470298 3834 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3835 sha_mpint(&s, K);
d39f364a 3836 SHA_Bytes(&s, H, 20);
3837 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3838 SHA_Bytes(&s, sessid, 20);
d39f364a 3839 SHA_Final(&s, keyspace);
3840 /* Next 20 bytes. */
3841 SHA_Init(&s);
51470298 3842 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3843 sha_mpint(&s, K);
d39f364a 3844 SHA_Bytes(&s, H, 20);
3845 SHA_Bytes(&s, keyspace, 20);
32874aea 3846 SHA_Final(&s, keyspace + 20);
d39f364a 3847}
3848
3849/*
7cca0d81 3850 * Handle the SSH2 transport layer.
e5574168 3851 */
51470298 3852static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3853{
51470298 3854 struct do_ssh2_transport_state {
3855 int nbits, pbits, warn;
3856 Bignum p, g, e, f, K;
3857 int kex_init_value, kex_reply_value;
3858 const struct ssh_mac **maclist;
3859 int nmacs;
3860 const struct ssh2_cipher *cscipher_tobe;
3861 const struct ssh2_cipher *sccipher_tobe;
3862 const struct ssh_mac *csmac_tobe;
3863 const struct ssh_mac *scmac_tobe;
3864 const struct ssh_compress *cscomp_tobe;
3865 const struct ssh_compress *sccomp_tobe;
3866 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3867 int hostkeylen, siglen;
3868 void *hkey; /* actual host key */
3869 unsigned char exchange_hash[20];
3870 int n_preferred_ciphers;
3871 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3872 const struct ssh_compress *preferred_comp;
3873 int first_kex;
3874 };
3875 crState(do_ssh2_transport_state);
3876
3877 crBegin(ssh->do_ssh2_transport_crstate);
3878
3879 s->cscipher_tobe = s->sccipher_tobe = NULL;
3880 s->csmac_tobe = s->scmac_tobe = NULL;
3881 s->cscomp_tobe = s->sccomp_tobe = NULL;
3882
7cca0d81 3883 random_init();
51470298 3884 s->first_kex = 1;
e5574168 3885
51470298 3886 {
3887 int i;
3888 /*
3889 * Set up the preferred ciphers. (NULL => warn below here)
3890 */
3891 s->n_preferred_ciphers = 0;
3892 for (i = 0; i < CIPHER_MAX; i++) {
86916870 3893 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 3894 case CIPHER_BLOWFISH:
3895 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3896 break;
3897 case CIPHER_DES:
86916870 3898 if (ssh->cfg.ssh2_des_cbc) {
51470298 3899 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3900 }
3901 break;
3902 case CIPHER_3DES:
3903 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3904 break;
3905 case CIPHER_AES:
3906 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3907 break;
3908 case CIPHER_WARN:
3909 /* Flag for later. Don't bother if it's the last in
3910 * the list. */
3911 if (i < CIPHER_MAX - 1) {
3912 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3913 }
3914 break;
ca20bfcf 3915 }
ca20bfcf 3916 }
5e8358ad 3917 }
ca20bfcf 3918
3919 /*
3920 * Set up preferred compression.
3921 */
86916870 3922 if (ssh->cfg.compression)
51470298 3923 s->preferred_comp = &ssh_zlib;
4ba9b64b 3924 else
51470298 3925 s->preferred_comp = &ssh_comp_none;
5e8358ad 3926
7591b9ff 3927 /*
3928 * Be prepared to work around the buggy MAC problem.
3929 */
51470298 3930 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3931 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3932 else
51470298 3933 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3934
32874aea 3935 begin_key_exchange:
51470298 3936 {
3937 int i, j, cipherstr_started;
3938
3939 /*
3940 * Construct and send our key exchange packet.
3941 */
3942 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3943 for (i = 0; i < 16; i++)
3944 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3945 /* List key exchange algorithms. */
3946 ssh2_pkt_addstring_start(ssh);
3947 for (i = 0; i < lenof(kex_algs); i++) {
3948 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3949 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3950 continue;
3951 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3952 if (i < lenof(kex_algs) - 1)
3953 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3954 }
51470298 3955 /* List server host key algorithms. */
3956 ssh2_pkt_addstring_start(ssh);
3957 for (i = 0; i < lenof(hostkey_algs); i++) {
3958 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3959 if (i < lenof(hostkey_algs) - 1)
3960 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3961 }
51470298 3962 /* List client->server encryption algorithms. */
3963 ssh2_pkt_addstring_start(ssh);
3964 cipherstr_started = 0;
3965 for (i = 0; i < s->n_preferred_ciphers; i++) {
3966 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3967 if (!c) continue; /* warning flag */
3968 for (j = 0; j < c->nciphers; j++) {
3969 if (cipherstr_started)
3970 ssh2_pkt_addstring_str(ssh, ",");
3971 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3972 cipherstr_started = 1;
3973 }
3974 }
3975 /* List server->client encryption algorithms. */
3976 ssh2_pkt_addstring_start(ssh);
3977 cipherstr_started = 0;
3978 for (i = 0; i < s->n_preferred_ciphers; i++) {
3979 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3980 if (!c) continue; /* warning flag */
3981 for (j = 0; j < c->nciphers; j++) {
3982 if (cipherstr_started)
3983 ssh2_pkt_addstring_str(ssh, ",");
3984 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3985 cipherstr_started = 1;
3986 }
3987 }
3988 /* List client->server MAC algorithms. */
3989 ssh2_pkt_addstring_start(ssh);
3990 for (i = 0; i < s->nmacs; i++) {
3991 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3992 if (i < s->nmacs - 1)
3993 ssh2_pkt_addstring_str(ssh, ",");
3994 }
3995 /* List server->client MAC algorithms. */
3996 ssh2_pkt_addstring_start(ssh);
3997 for (i = 0; i < s->nmacs; i++) {
3998 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3999 if (i < s->nmacs - 1)
4000 ssh2_pkt_addstring_str(ssh, ",");
4001 }
4002 /* List client->server compression algorithms. */
4003 ssh2_pkt_addstring_start(ssh);
4004 for (i = 0; i < lenof(compressions) + 1; i++) {
4005 const struct ssh_compress *c =
4006 i == 0 ? s->preferred_comp : compressions[i - 1];
4007 ssh2_pkt_addstring_str(ssh, c->name);
4008 if (i < lenof(compressions))
4009 ssh2_pkt_addstring_str(ssh, ",");
4010 }
4011 /* List server->client compression algorithms. */
4012 ssh2_pkt_addstring_start(ssh);
4013 for (i = 0; i < lenof(compressions) + 1; i++) {
4014 const struct ssh_compress *c =
4015 i == 0 ? s->preferred_comp : compressions[i - 1];
4016 ssh2_pkt_addstring_str(ssh, c->name);
4017 if (i < lenof(compressions))
4018 ssh2_pkt_addstring_str(ssh, ",");
4019 }
4020 /* List client->server languages. Empty list. */
4021 ssh2_pkt_addstring_start(ssh);
4022 /* List server->client languages. Empty list. */
4023 ssh2_pkt_addstring_start(ssh);
4024 /* First KEX packet does _not_ follow, because we're not that brave. */
4025 ssh2_pkt_addbool(ssh, FALSE);
4026 /* Reserved. */
4027 ssh2_pkt_adduint32(ssh, 0);
e5574168 4028 }
0db56f73 4029
51470298 4030 ssh->exhash = ssh->exhashbase;
4031 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 4032
51470298 4033 ssh2_pkt_send(ssh);
e5574168 4034
32874aea 4035 if (!ispkt)
4036 crWaitUntil(ispkt);
57356d63 4037 if (ssh->pktin.length > 5)
4038 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 4039
4040 /*
4041 * Now examine the other side's KEXINIT to see what we're up
4042 * to.
4043 */
51470298 4044 {
4045 char *str;
4046 int i, j, len;
4047
4048 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4049 bombout(("expected key exchange packet from server"));
7ffdbc1a 4050 crStop(0);
32874aea 4051 }
51470298 4052 ssh->kex = NULL;
4053 ssh->hostkey = NULL;
4054 s->cscipher_tobe = NULL;
4055 s->sccipher_tobe = NULL;
4056 s->csmac_tobe = NULL;
4057 s->scmac_tobe = NULL;
4058 s->cscomp_tobe = NULL;
4059 s->sccomp_tobe = NULL;
4060 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4061 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4062 for (i = 0; i < lenof(kex_algs); i++) {
4063 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4064 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4065 continue;
4066 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4067 ssh->kex = kex_algs[i];
4068 break;
4069 }
32874aea 4070 }
51470298 4071 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4072 for (i = 0; i < lenof(hostkey_algs); i++) {
4073 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4074 ssh->hostkey = hostkey_algs[i];
4075 break;
4076 }
4077 }
4078 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4079 s->warn = 0;
4080 for (i = 0; i < s->n_preferred_ciphers; i++) {
4081 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4082 if (!c) {
4083 s->warn = 1;
4084 } else {
4085 for (j = 0; j < c->nciphers; j++) {
4086 if (in_commasep_string(c->list[j]->name, str, len)) {
4087 s->cscipher_tobe = c->list[j];
4088 break;
4089 }
ca20bfcf 4090 }
32874aea 4091 }
51470298 4092 if (s->cscipher_tobe) {
4093 if (s->warn)
a8327734 4094 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4095 break;
4096 }
32874aea 4097 }
51470298 4098 if (!s->cscipher_tobe) {
6b5cf8b4 4099 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4100 str ? str : "(null)"));
7ffdbc1a 4101 crStop(0);
ca20bfcf 4102 }
0ef8f407 4103
51470298 4104 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4105 s->warn = 0;
4106 for (i = 0; i < s->n_preferred_ciphers; i++) {
4107 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4108 if (!c) {
4109 s->warn = 1;
4110 } else {
4111 for (j = 0; j < c->nciphers; j++) {
4112 if (in_commasep_string(c->list[j]->name, str, len)) {
4113 s->sccipher_tobe = c->list[j];
4114 break;
4115 }
ca20bfcf 4116 }
32874aea 4117 }
51470298 4118 if (s->sccipher_tobe) {
4119 if (s->warn)
a8327734 4120 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4121 break;
4122 }
32874aea 4123 }
51470298 4124 if (!s->sccipher_tobe) {
6b5cf8b4 4125 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4126 str ? str : "(null)"));
7ffdbc1a 4127 crStop(0);
ca20bfcf 4128 }
0ef8f407 4129
51470298 4130 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4131 for (i = 0; i < s->nmacs; i++) {
4132 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4133 s->csmac_tobe = s->maclist[i];
4134 break;
4135 }
32874aea 4136 }
51470298 4137 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4138 for (i = 0; i < s->nmacs; i++) {
4139 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4140 s->scmac_tobe = s->maclist[i];
4141 break;
4142 }
32874aea 4143 }
51470298 4144 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4145 for (i = 0; i < lenof(compressions) + 1; i++) {
4146 const struct ssh_compress *c =
4147 i == 0 ? s->preferred_comp : compressions[i - 1];
4148 if (in_commasep_string(c->name, str, len)) {
4149 s->cscomp_tobe = c;
4150 break;
4151 }
32874aea 4152 }
51470298 4153 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4154 for (i = 0; i < lenof(compressions) + 1; i++) {
4155 const struct ssh_compress *c =
4156 i == 0 ? s->preferred_comp : compressions[i - 1];
4157 if (in_commasep_string(c->name, str, len)) {
4158 s->sccomp_tobe = c;
4159 break;
4160 }
32874aea 4161 }
e5574168 4162 }
e5574168 4163
4164 /*
7bd5a860 4165 * Work out the number of bits of key we will need from the key
4166 * exchange. We start with the maximum key length of either
4167 * cipher...
4168 */
4169 {
32874aea 4170 int csbits, scbits;
7bd5a860 4171
51470298 4172 csbits = s->cscipher_tobe->keylen;
4173 scbits = s->sccipher_tobe->keylen;
4174 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4175 }
4176 /* The keys only have 160-bit entropy, since they're based on
4177 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4178 if (s->nbits > 160)
4179 s->nbits = 160;
7bd5a860 4180
4181 /*
a92dd380 4182 * If we're doing Diffie-Hellman group exchange, start by
4183 * requesting a group.
e5574168 4184 */
51470298 4185 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4186 logevent("Doing Diffie-Hellman group exchange");
51470298 4187 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4188 /*
4189 * Work out how big a DH group we will need to allow that
4190 * much data.
7bd5a860 4191 */
51470298 4192 s->pbits = 512 << ((s->nbits - 1) / 64);
4193 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4194 ssh2_pkt_adduint32(ssh, s->pbits);
4195 ssh2_pkt_send(ssh);
32874aea 4196
4197 crWaitUntil(ispkt);
51470298 4198 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4199 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4200 crStop(0);
32874aea 4201 }
51470298 4202 s->p = ssh2_pkt_getmp(ssh);
4203 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 4204 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4205 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4206 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4207 } else {
51470298 4208 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4209 ssh->kex_ctx = dh_setup_group1();
51470298 4210 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4211 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4212 }
e5574168 4213
a92dd380 4214 logevent("Doing Diffie-Hellman key exchange");
e5574168 4215 /*
a92dd380 4216 * Now generate and send e for Diffie-Hellman.
e5574168 4217 */
27cd7fc2 4218 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 4219 ssh2_pkt_init(ssh, s->kex_init_value);
4220 ssh2_pkt_addmp(ssh, s->e);
4221 ssh2_pkt_send(ssh);
e5574168 4222
4223 crWaitUntil(ispkt);
51470298 4224 if (ssh->pktin.type != s->kex_reply_value) {
6b5cf8b4 4225 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4226 crStop(0);
7cca0d81 4227 }
51470298 4228 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4229 s->f = ssh2_pkt_getmp(ssh);
4230 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4231
27cd7fc2 4232 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4233
51470298 4234 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4235 if (ssh->kex == &ssh_diffiehellman_gex) {
4236 sha_uint32(&ssh->exhash, s->pbits);
4237 sha_mpint(&ssh->exhash, s->p);
4238 sha_mpint(&ssh->exhash, s->g);
a92dd380 4239 }
51470298 4240 sha_mpint(&ssh->exhash, s->e);
4241 sha_mpint(&ssh->exhash, s->f);
4242 sha_mpint(&ssh->exhash, s->K);
4243 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4244
27cd7fc2 4245 dh_cleanup(ssh->kex_ctx);
fabd1805 4246 ssh->kex_ctx = NULL;
3709bfe9 4247
7cca0d81 4248#if 0
765c4200 4249 debug(("Exchange hash is:\n"));
51470298 4250 dmemdump(s->exchange_hash, 20);
7cca0d81 4251#endif
4252
51470298 4253 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4254 if (!s->hkey ||
4255 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4256 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4257 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4258 crStop(0);
8d5de777 4259 }
e5574168 4260
4261 /*
7cca0d81 4262 * Authenticate remote host: verify host key. (We've already
4263 * checked the signature of the exchange hash.)
e5574168 4264 */
51470298 4265 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4266 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4267 verify_ssh_host_key(ssh->frontend,
4268 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4269 s->keystr, s->fingerprint);
4270 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4271 logevent("Host key fingerprint is:");
51470298 4272 logevent(s->fingerprint);
5e0d7cb8 4273 }
51470298 4274 sfree(s->fingerprint);
4275 sfree(s->keystr);
4276 ssh->hostkey->freekey(s->hkey);
d39f364a 4277
4278 /*
7cca0d81 4279 * Send SSH2_MSG_NEWKEYS.
d39f364a 4280 */
51470298 4281 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4282 ssh2_pkt_send(ssh);
d39f364a 4283
4284 /*
8406eaf9 4285 * Expect SSH2_MSG_NEWKEYS from server.
4286 */
4287 crWaitUntil(ispkt);
51470298 4288 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4289 bombout(("expected new-keys packet from server"));
7ffdbc1a 4290 crStop(0);
8406eaf9 4291 }
4292
4293 /*
d39f364a 4294 * Create and initialise session keys.
4295 */
371e569c 4296 if (ssh->cs_cipher_ctx)
4297 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4298 ssh->cscipher = s->cscipher_tobe;
371e569c 4299 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4300
371e569c 4301 if (ssh->sc_cipher_ctx)
4302 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4303 ssh->sccipher = s->sccipher_tobe;
371e569c 4304 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4305
4306 if (ssh->cs_mac_ctx)
4307 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4308 ssh->csmac = s->csmac_tobe;
e0e1a00d 4309 ssh->cs_mac_ctx = ssh->csmac->make_context();
4310
4311 if (ssh->sc_mac_ctx)
4312 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4313 ssh->scmac = s->scmac_tobe;
e0e1a00d 4314 ssh->sc_mac_ctx = ssh->scmac->make_context();
4315
5366aed8 4316 if (ssh->cs_comp_ctx)
4317 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4318 ssh->cscomp = s->cscomp_tobe;
5366aed8 4319 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4320
4321 if (ssh->sc_comp_ctx)
4322 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4323 ssh->sccomp = s->sccomp_tobe;
5366aed8 4324 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4325
d39f364a 4326 /*
5e0d7cb8 4327 * Set IVs after keys. Here we use the exchange hash from the
4328 * _first_ key exchange.
d39f364a 4329 */
51470298 4330 {
4331 unsigned char keyspace[40];
4332 if (s->first_kex)
4333 memcpy(ssh->v2_session_id, s->exchange_hash,
4334 sizeof(s->exchange_hash));
4335 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4336 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4337 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4338 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4339 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4340 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4341 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4342 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4343 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4344 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4345 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4346 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4347 }
57356d63 4348 logeventf(ssh, "Initialised %.200s client->server encryption",
4349 ssh->cscipher->text_name);
4350 logeventf(ssh, "Initialised %.200s server->client encryption",
4351 ssh->sccipher->text_name);
4352 if (ssh->cscomp->text_name)
4353 logeventf(ssh, "Initialised %s compression",
4354 ssh->cscomp->text_name);
4355 if (ssh->sccomp->text_name)
4356 logeventf(ssh, "Initialised %s decompression",
4357 ssh->sccomp->text_name);
679539d7 4358 freebn(s->f);
679539d7 4359 freebn(s->K);
b3949e7e 4360 if (ssh->kex == &ssh_diffiehellman_gex) {
4361 freebn(s->g);
4362 freebn(s->p);
4363 }
d39f364a 4364
033b4cef 4365 /*
0db56f73 4366 * If this is the first key exchange phase, we must pass the
4367 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4368 * wants to see it but because it will need time to initialise
4369 * itself before it sees an actual packet. In subsequent key
4370 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4371 * it would only confuse the layer above.
4372 */
51470298 4373 if (!s->first_kex) {
32874aea 4374 crReturn(0);
0db56f73 4375 }
51470298 4376 s->first_kex = 0;
0db56f73 4377
4378 /*
7cca0d81 4379 * Now we're encrypting. Begin returning 1 to the protocol main
4380 * function so that other things can run on top of the
4381 * transport. If we ever see a KEXINIT, we must go back to the
4382 * start.
033b4cef 4383 */
51470298 4384 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4385 crReturn(1);
e96adf72 4386 }
5e0d7cb8 4387 logevent("Server initiated key re-exchange");
7cca0d81 4388 goto begin_key_exchange;
e5574168 4389
4390 crFinish(1);
4391}
4392
7cca0d81 4393/*
783415f8 4394 * Add data to an SSH2 channel output buffer.
4395 */
32874aea 4396static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4397 int len)
4398{
5471d09a 4399 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4400}
4401
4402/*
4403 * Attempt to send data on an SSH2 channel.
4404 */
5471d09a 4405static int ssh2_try_send(struct ssh_channel *c)
32874aea 4406{
51470298 4407 Ssh ssh = c->ssh;
4408
5471d09a 4409 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4410 int len;
4411 void *data;
4412 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4413 if ((unsigned)len > c->v.v2.remwindow)
4414 len = c->v.v2.remwindow;
4415 if ((unsigned)len > c->v.v2.remmaxpkt)
4416 len = c->v.v2.remmaxpkt;
51470298 4417 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4418 ssh2_pkt_adduint32(ssh, c->remoteid);
4419 ssh2_pkt_addstring_start(ssh);
4420 ssh2_pkt_addstring_data(ssh, data, len);
4421 ssh2_pkt_send(ssh);
5471d09a 4422 bufchain_consume(&c->v.v2.outbuffer, len);
4423 c->v.v2.remwindow -= len;
4424 }
4425
4426 /*
4427 * After having sent as much data as we can, return the amount
4428 * still buffered.
4429 */
4430 return bufchain_size(&c->v.v2.outbuffer);
4431}
4432
4433/*
4434 * Potentially enlarge the window on an SSH2 channel.
4435 */
4436static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4437{
51470298 4438 Ssh ssh = c->ssh;
4439
6b69f42e 4440 /*
4441 * Never send WINDOW_ADJUST for a channel that the remote side
4442 * already thinks it's closed; there's no point, since it won't
4443 * be sending any more data anyway.
4444 */
4445 if (c->closes != 0)
4446 return;
4447
5471d09a 4448 if (newwin > c->v.v2.locwindow) {
51470298 4449 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4450 ssh2_pkt_adduint32(ssh, c->remoteid);
4451 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4452 ssh2_pkt_send(ssh);
5471d09a 4453 c->v.v2.locwindow = newwin;
783415f8 4454 }
4455}
4456
4457/*
7cca0d81 4458 * Handle the SSH2 userauth and connection layers.
4459 */
51470298 4460static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4461{
51470298 4462 struct do_ssh2_authconn_state {
4463 enum {
4464 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4465 AUTH_PASSWORD,
4466 AUTH_KEYBOARD_INTERACTIVE
4467 } method;
4468 enum {
4469 AUTH_TYPE_NONE,
4470 AUTH_TYPE_PUBLICKEY,
4471 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4472 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4473 AUTH_TYPE_PASSWORD,
4474 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4475 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4476 } type;
4477 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4478 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4479 int kbd_inter_running;
4480 int we_are_in;
4481 int num_prompts, curr_prompt, echo;
4482 char username[100];
4483 int got_username;
4484 char pwprompt[200];
4485 char password[100];
4486 void *publickey_blob;
4487 int publickey_bloblen;
4488 unsigned char request[5], *response, *p;
4489 int responselen;
4490 int keyi, nkeys;
4491 int authed;
4492 char *pkblob, *alg, *commentp;
4493 int pklen, alglen, commentlen;
4494 int siglen, retlen, len;
4495 char *q, *agentreq, *ret;
4496 int try_send;
4497 };
4498 crState(do_ssh2_authconn_state);
4499
4500 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4501
7cca0d81 4502 /*
4503 * Request userauth protocol, and await a response to it.
4504 */
51470298 4505 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4506 ssh2_pkt_addstring(ssh, "ssh-userauth");
4507 ssh2_pkt_send(ssh);
7cca0d81 4508 crWaitUntilV(ispkt);
51470298 4509 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 4510 bombout(("Server refused user authentication protocol"));
7ffdbc1a 4511 crStopV;
8d5de777 4512 }
7cca0d81 4513
4514 /*
1408a877 4515 * We repeat this whole loop, including the username prompt,
4516 * until we manage a successful authentication. If the user
51470298 4517 * types the wrong _password_, they can be sent back to the
4518 * beginning to try another username, if this is configured on.
4519 * (If they specify a username in the config, they are never
4520 * asked, even if they do give a wrong password.)
1408a877 4521 *
4522 * I think this best serves the needs of
4523 *
4524 * - the people who have no configuration, no keys, and just
4525 * want to try repeated (username,password) pairs until they
4526 * type both correctly
4527 *
4528 * - people who have keys and configuration but occasionally
4529 * need to fall back to passwords
4530 *
4531 * - people with a key held in Pageant, who might not have
4532 * logged in to a particular machine before; so they want to
4533 * type a username, and then _either_ their key will be
4534 * accepted, _or_ they will type a password. If they mistype
4535 * the username they will want to be able to get back and
4536 * retype it!
7cca0d81 4537 */
51470298 4538 s->username[0] = '\0';
4539 s->got_username = FALSE;
1408a877 4540 do {
1408a877 4541 /*
4542 * Get a username.
4543 */
86916870 4544 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 4545 /*
4546 * We got a username last time round this loop, and
4547 * with change_username turned off we don't try to get
4548 * it again.
4549 */
86916870 4550 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 4551 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4552 if (!ssh_get_line("login as: ",
51470298 4553 s->username, sizeof(s->username), FALSE)) {
32874aea 4554 /*
4555 * get_line failed to get a username.
4556 * Terminate.
4557 */
4558 logevent("No username provided. Abandoning session.");
3bb2f322 4559 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4560 crStopV;
32874aea 4561 }
4562 } else {
51470298 4563 int ret; /* need not be saved across crReturn */
4564 c_write_str(ssh, "login as: ");
4565 ssh->send_ok = 1;
4566 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4567 do {
32874aea 4568 crWaitUntilV(!ispkt);
51470298 4569 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4570 } while (ret == 0);
4571 if (ret < 0)
4572 cleanup_exit(0);
4ca0c9d1 4573 c_write_str(ssh, "\r\n");
32874aea 4574 }
51470298 4575 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4576 } else {
57356d63 4577 char *stuff;
86916870 4578 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 4579 s->username[sizeof(s->username)-1] = '\0';
65a22376 4580 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 4581 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 4582 c_write_str(ssh, stuff);
57356d63 4583 sfree(stuff);
7cca0d81 4584 }
4585 }
51470298 4586 s->got_username = TRUE;
7cca0d81 4587
65a22376 4588 /*
1408a877 4589 * Send an authentication request using method "none": (a)
4590 * just in case it succeeds, and (b) so that we know what
4591 * authentication methods we can usefully try next.
65a22376 4592 */
51470298 4593 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4594
4595 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4596 ssh2_pkt_addstring(ssh, s->username);
4597 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4598 ssh2_pkt_addstring(ssh, "none"); /* method */
4599 ssh2_pkt_send(ssh);
4600 s->type = AUTH_TYPE_NONE;
4601 s->gotit = FALSE;
4602 s->we_are_in = FALSE;
4603
4604 s->tried_pubkey_config = FALSE;
4605 s->tried_agent = FALSE;
4606 s->tried_keyb_inter = FALSE;
4607 s->kbd_inter_running = FALSE;
86916870 4608 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 4609 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 4610 int keytype;
6c6d9ed9 4611 logeventf(ssh, "Reading private key file \"%.150s\"",
4612 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 4613 keytype = key_type(&ssh->cfg.keyfile);
51470298 4614 if (keytype == SSH_KEYTYPE_SSH2) {
4615 s->publickey_blob =
9a30e26b 4616 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 4617 &s->publickey_bloblen, NULL);
51470298 4618 } else {
57356d63 4619 char *msgbuf;
c2ad7d0d 4620 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 4621 key_type_to_str(keytype));
57356d63 4622 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 4623 " (%s)\r\n",
4624 filename_to_str(&ssh->cfg.keyfile),
57356d63 4625 key_type_to_str(keytype));
51470298 4626 c_write_str(ssh, msgbuf);
57356d63 4627 sfree(msgbuf);
51470298 4628 s->publickey_blob = NULL;
231ee168 4629 }
396778f1 4630 } else
51470298 4631 s->publickey_blob = NULL;
65a22376 4632
1408a877 4633 while (1) {
4634 /*
4635 * Wait for the result of the last authentication request.
4636 */
51470298 4637 if (!s->gotit)
1408a877 4638 crWaitUntilV(ispkt);
51470298 4639 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4640 char *banner;
4641 int size;
4642 /*
4643 * Don't show the banner if we're operating in
4644 * non-verbose non-interactive mode. (It's probably
4645 * a script, which means nobody will read the
4646 * banner _anyway_, and moreover the printing of
4647 * the banner will screw up processing on the
4648 * output of (say) plink.)
4649 */
4650 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4651 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4652 if (banner)
51470298 4653 c_write_untrusted(ssh, banner, size);
32874aea 4654 }
1408a877 4655 crWaitUntilV(ispkt);
4656 }
51470298 4657 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4658 logevent("Access granted");
51470298 4659 s->we_are_in = TRUE;
1408a877 4660 break;
4661 }
65a22376 4662
51470298 4663 if (s->kbd_inter_running &&
4664 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4665 /*
45068b27 4666 * This is either a further set-of-prompts packet
4667 * in keyboard-interactive authentication, or it's
4668 * the same one and we came back here with `gotit'
4669 * set. In the former case, we must reset the
4670 * curr_prompt variable.
b3186d64 4671 */
51470298 4672 if (!s->gotit)
4673 s->curr_prompt = 0;
4674 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 4675 bombout(("Strange packet received during authentication: type %d",
51470298 4676 ssh->pktin.type));
7ffdbc1a 4677 crStopV;
65a22376 4678 }
4679
51470298 4680 s->gotit = FALSE;
65a22376 4681
1408a877 4682 /*
4683 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4684 * we can look at the string in it and know what we can
4685 * helpfully try next.
4686 */
51470298 4687 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4688 char *methods;
4689 int methlen;
51470298 4690 ssh2_pkt_getstring(ssh, &methods, &methlen);
4691 s->kbd_inter_running = FALSE;
4692 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4693 /*
4694 * We have received an unequivocal Access
4695 * Denied. This can translate to a variety of
4696 * messages:
4697 *
4698 * - if we'd just tried "none" authentication,
4699 * it's not worth printing anything at all
4700 *
4701 * - if we'd just tried a public key _offer_,
4702 * the message should be "Server refused our
4703 * key" (or no message at all if the key
4704 * came from Pageant)
4705 *
4706 * - if we'd just tried anything else, the
4707 * message really should be "Access denied".
4708 *
4709 * Additionally, if we'd just tried password
4710 * authentication, we should break out of this
4711 * whole loop so as to go back to the username
4712 * prompt.
4713 */
51470298 4714 if (s->type == AUTH_TYPE_NONE) {
1408a877 4715 /* do nothing */
51470298 4716 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4717 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4718 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4719 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4720 logevent("Server refused public key");
51470298 4721 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4722 /* server declined keyboard-interactive; ignore */
1408a877 4723 } else {
51470298 4724 c_write_str(ssh, "Access denied\r\n");
1408a877 4725 logevent("Access denied");
51470298 4726 if (s->type == AUTH_TYPE_PASSWORD) {
4727 s->we_are_in = FALSE;
1408a877 4728 break;
4729 }
4730 }
4731 } else {
51470298 4732 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4733 logevent("Further authentication required");
4734 }
65a22376 4735
51470298 4736 s->can_pubkey =
32874aea 4737 in_commasep_string("publickey", methods, methlen);
51470298 4738 s->can_passwd =
32874aea 4739 in_commasep_string("password", methods, methlen);
86916870 4740 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 4741 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4742 }
65a22376 4743
51470298 4744 s->method = 0;
4745 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4746
0405e71f 4747 /*
4748 * Most password/passphrase prompts will be
4749 * non-echoing, so we set this to 0 by default.
4750 * Exception is that some keyboard-interactive prompts
4751 * can be echoing, in which case we'll set this to 1.
4752 */
51470298 4753 s->echo = 0;
0405e71f 4754
51470298 4755 if (!s->method && s->can_pubkey &&
4756 agent_exists() && !s->tried_agent) {
1983e559 4757 /*
4758 * Attempt public-key authentication using Pageant.
4759 */
1983e559 4760 void *r;
51470298 4761 s->authed = FALSE;
1983e559 4762
51470298 4763 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4764 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4765
51470298 4766 s->tried_agent = TRUE;
1983e559 4767
4768 logevent("Pageant is running. Requesting keys.");
4769
4770 /* Request the keys held by the agent. */
51470298 4771 PUT_32BIT(s->request, 1);
4772 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 4773 if (!agent_query(s->request, 5, &r, &s->responselen,
4774 ssh_agent_callback, ssh)) {
4775 do {
4776 crReturnV;
4777 if (ispkt) {
4778 bombout(("Unexpected data from server while"
4779 " waiting for agent response"));
4780 crStopV;
4781 }
4782 } while (ispkt || inlen > 0);
4783 r = ssh->agent_response;
4784 s->responselen = ssh->agent_response_len;
4785 }
51470298 4786 s->response = (unsigned char *) r;
4787 if (s->response && s->responselen >= 5 &&
4788 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4789 s->p = s->response + 5;
4790 s->nkeys = GET_32BIT(s->p);
4791 s->p += 4;
32874aea 4792 {
4793 char buf[64];
51470298 4794 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4795 logevent(buf);
4796 }
51470298 4797 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4798 void *vret;
1983e559 4799
32874aea 4800 {
4801 char buf[64];
51470298 4802 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4803 logevent(buf);
4804 }
51470298 4805 s->pklen = GET_32BIT(s->p);
4806 s->p += 4;
4807 if (s->publickey_blob &&
4808 s->pklen == s->publickey_bloblen &&
4809 !memcmp(s->p, s->publickey_blob,
4810 s->publickey_bloblen)) {
396778f1 4811 logevent("This key matches configured key file");
51470298 4812 s->tried_pubkey_config = 1;
396778f1 4813 }
d8baa528 4814 s->pkblob = (char *)s->p;
51470298 4815 s->p += s->pklen;
4816 s->alglen = GET_32BIT(s->pkblob);
4817 s->alg = s->pkblob + 4;
4818 s->commentlen = GET_32BIT(s->p);
4819 s->p += 4;
d8baa528 4820 s->commentp = (char *)s->p;
51470298 4821 s->p += s->commentlen;
4822 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4823 ssh2_pkt_addstring(ssh, s->username);
4824 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4825 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4826 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4827 ssh2_pkt_addstring_start(ssh);
4828 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4829 ssh2_pkt_addstring_start(ssh);
4830 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4831 ssh2_pkt_send(ssh);
1983e559 4832
4833 crWaitUntilV(ispkt);
51470298 4834 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4835 logevent("Key refused");
4836 continue;
4837 }
4838
32874aea 4839 if (flags & FLAG_VERBOSE) {
51470298 4840 c_write_str(ssh, "Authenticating with "
4841 "public key \"");
4842 c_write(ssh, s->commentp, s->commentlen);
4843 c_write_str(ssh, "\" from agent\r\n");
32874aea 4844 }
1983e559 4845
4846 /*
4847 * Server is willing to accept the key.
4848 * Construct a SIGN_REQUEST.
4849 */
51470298 4850 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4851 ssh2_pkt_addstring(ssh, s->username);
4852 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4853 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4854 ssh2_pkt_addbool(ssh, TRUE);
4855 ssh2_pkt_addstring_start(ssh);
4856 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4857 ssh2_pkt_addstring_start(ssh);
4858 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4859
4860 s->siglen = ssh->pktout.length - 5 + 4 + 20;
dda87a28 4861 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4862 s->siglen -= 4;
51470298 4863 s->len = 1; /* message type */
4864 s->len += 4 + s->pklen; /* key blob */
4865 s->len += 4 + s->siglen; /* data to sign */
4866 s->len += 4; /* flags */
3d88e64d 4867 s->agentreq = snewn(4 + s->len, char);
51470298 4868 PUT_32BIT(s->agentreq, s->len);
4869 s->q = s->agentreq + 4;
4870 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4871 PUT_32BIT(s->q, s->pklen);
4872 s->q += 4;
4873 memcpy(s->q, s->pkblob, s->pklen);
4874 s->q += s->pklen;
4875 PUT_32BIT(s->q, s->siglen);
4876 s->q += 4;
1983e559 4877 /* Now the data to be signed... */
dda87a28 4878 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4879 PUT_32BIT(s->q, 20);
4880 s->q += 4;
4881 }
51470298 4882 memcpy(s->q, ssh->v2_session_id, 20);
4883 s->q += 20;
4884 memcpy(s->q, ssh->pktout.data + 5,
4885 ssh->pktout.length - 5);
4886 s->q += ssh->pktout.length - 5;
1983e559 4887 /* And finally the (zero) flags word. */
51470298 4888 PUT_32BIT(s->q, 0);
839f10db 4889 if (!agent_query(s->agentreq, s->len + 4,
4890 &vret, &s->retlen,
4891 ssh_agent_callback, ssh)) {
4892 do {
4893 crReturnV;
4894 if (ispkt) {
4895 bombout(("Unexpected data from server"
4896 " while waiting for agent"
4897 " response"));
4898 crStopV;
4899 }
4900 } while (ispkt || inlen > 0);
4901 vret = ssh->agent_response;
4902 s->retlen = ssh->agent_response_len;
4903 }
51470298 4904 s->ret = vret;
4905 sfree(s->agentreq);
4906 if (s->ret) {
4907 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4908 logevent("Sending Pageant's response");
51470298 4909 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4910 s->ret + 9,
4911 GET_32BIT(s->ret + 5));
4912 ssh2_pkt_send(ssh);
4913 s->authed = TRUE;
1983e559 4914 break;
4915 } else {
32874aea 4916 logevent
4917 ("Pageant failed to answer challenge");
51470298 4918 sfree(s->ret);
1983e559 4919 }
4920 }
4921 }
51470298 4922 if (s->authed)
1983e559 4923 continue;
4924 }
4925 }
4926
51470298 4927 if (!s->method && s->can_pubkey && s->publickey_blob
4928 && !s->tried_pubkey_config) {
1408a877 4929 unsigned char *pub_blob;
4930 char *algorithm, *comment;
4931 int pub_blob_len;
65a22376 4932
51470298 4933 s->tried_pubkey_config = TRUE;
65a22376 4934
51470298 4935 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4936 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4937
65a22376 4938 /*
1408a877 4939 * Try the public key supplied in the configuration.
4940 *
4941 * First, offer the public blob to see if the server is
4942 * willing to accept it.
65a22376 4943 */
d8baa528 4944 pub_blob =
9a30e26b 4945 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 4946 &algorithm,
222d54dc 4947 &pub_blob_len,
4948 NULL);
1408a877 4949 if (pub_blob) {
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, "publickey"); /* method */
4954 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4955 ssh2_pkt_addstring(ssh, algorithm);
4956 ssh2_pkt_addstring_start(ssh);
d8baa528 4957 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4958 pub_blob_len);
51470298 4959 ssh2_pkt_send(ssh);
32874aea 4960 logevent("Offered public key"); /* FIXME */
1408a877 4961
4962 crWaitUntilV(ispkt);
51470298 4963 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4964 s->gotit = TRUE;
4965 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4966 continue; /* key refused; give up on it */
1408a877 4967 }
65a22376 4968
1408a877 4969 logevent("Offer of public key accepted");
65a22376 4970 /*
1408a877 4971 * Actually attempt a serious authentication using
4972 * the key.
65a22376 4973 */
9a30e26b 4974 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 4975 sprintf(s->pwprompt,
32874aea 4976 "Passphrase for key \"%.100s\": ",
4977 comment);
51470298 4978 s->need_pw = TRUE;
1408a877 4979 } else {
51470298 4980 s->need_pw = FALSE;
1408a877 4981 }
51470298 4982 c_write_str(ssh, "Authenticating with public key \"");
4983 c_write_str(ssh, comment);
4984 c_write_str(ssh, "\"\r\n");
4985 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4986 }
1408a877 4987 }
4988
51470298 4989 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4990 s->method = AUTH_KEYBOARD_INTERACTIVE;
4991 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4992 s->tried_keyb_inter = TRUE;
af659722 4993
51470298 4994 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4995 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4996
51470298 4997 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4998 ssh2_pkt_addstring(ssh, s->username);
4999 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5000 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5001 ssh2_pkt_addstring(ssh, ""); /* lang */
5002 ssh2_pkt_addstring(ssh, "");
5003 ssh2_pkt_send(ssh);
af659722 5004
5005 crWaitUntilV(ispkt);
51470298 5006 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5007 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5008 s->gotit = TRUE;
af659722 5009 logevent("Keyboard-interactive authentication refused");
51470298 5010 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 5011 continue;
5012 }
5013
51470298 5014 s->kbd_inter_running = TRUE;
5015 s->curr_prompt = 0;
af659722 5016 }
5017
51470298 5018 if (s->kbd_inter_running) {
5019 s->method = AUTH_KEYBOARD_INTERACTIVE;
5020 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5021 s->tried_keyb_inter = TRUE;
af659722 5022
51470298 5023 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5024 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 5025
51470298 5026 if (s->curr_prompt == 0) {
45068b27 5027 /*
5028 * We've got a fresh USERAUTH_INFO_REQUEST.
5029 * Display header data, and start going through
5030 * the prompts.
5031 */
5032 char *name, *inst, *lang;
5033 int name_len, inst_len, lang_len;
5034
51470298 5035 ssh2_pkt_getstring(ssh, &name, &name_len);
5036 ssh2_pkt_getstring(ssh, &inst, &inst_len);
5037 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 5038 if (name_len > 0) {
51470298 5039 c_write_untrusted(ssh, name, name_len);
5040 c_write_str(ssh, "\r\n");
45068b27 5041 }
5042 if (inst_len > 0) {
51470298 5043 c_write_untrusted(ssh, inst, inst_len);
5044 c_write_str(ssh, "\r\n");
45068b27 5045 }
51470298 5046 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 5047 }
af659722 5048
45068b27 5049 /*
5050 * If there are prompts remaining in the packet,
5051 * display one and get a response.
5052 */
51470298 5053 if (s->curr_prompt < s->num_prompts) {
45068b27 5054 char *prompt;
5055 int prompt_len;
af659722 5056
51470298 5057 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 5058 if (prompt_len > 0) {
51470298 5059 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
5060 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
5061 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 5062 } else {
51470298 5063 strcpy(s->pwprompt,
45068b27 5064 "<server failed to send prompt>: ");
5065 }
51470298 5066 s->echo = ssh2_pkt_getbool(ssh);
5067 s->need_pw = TRUE;
45068b27 5068 } else
51470298 5069 s->need_pw = FALSE;
af659722 5070 }
5071
51470298 5072 if (!s->method && s->can_passwd) {
5073 s->method = AUTH_PASSWORD;
5074 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5075 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5076 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5077 ssh->savedhost);
5078 s->need_pw = TRUE;
1408a877 5079 }
5080
51470298 5081 if (s->need_pw) {
fa17a66e 5082 if (ssh_get_line) {
51470298 5083 if (!ssh_get_line(s->pwprompt, s->password,
5084 sizeof(s->password), TRUE)) {
1408a877 5085 /*
fa17a66e 5086 * get_line failed to get a password (for
5087 * example because one was supplied on the
5088 * command line which has already failed to
5089 * work). Terminate.
1408a877 5090 */
51470298 5091 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5092 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5093 ssh2_pkt_addstring(ssh, "No more passwords available"
5094 " to try");
5095 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5096 ssh2_pkt_send(ssh);
247308b5 5097 logevent("Unable to authenticate");
a8327734 5098 connection_fatal(ssh->frontend,
5099 "Unable to authenticate");
3bb2f322 5100 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5101 crStopV;
1408a877 5102 }
5103 } else {
51470298 5104 int ret; /* need not be saved across crReturn */
5105 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5106 ssh->send_ok = 1;
1408a877 5107
51470298 5108 setup_userpass_input(ssh, s->password,
5109 sizeof(s->password), s->echo);
0405e71f 5110 do {
1408a877 5111 crWaitUntilV(!ispkt);
51470298 5112 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5113 } while (ret == 0);
5114 if (ret < 0)
5115 cleanup_exit(0);
51470298 5116 c_write_str(ssh, "\r\n");
65a22376 5117 }
65a22376 5118 }
65a22376 5119
51470298 5120 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 5121 /*
5122 * We have our passphrase. Now try the actual authentication.
5123 */
5124 struct ssh2_userkey *key;
222d54dc 5125 const char *error = NULL;
65a22376 5126
222d54dc 5127 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5128 &error);
1408a877 5129 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5130 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 5131 c_write_str(ssh, "Wrong passphrase\r\n");
5132 s->tried_pubkey_config = FALSE;
1408a877 5133 } else {
222d54dc 5134 c_write_str(ssh, "Unable to load private key (");
5135 c_write_str(ssh, error);
5136 c_write_str(ssh, ")\r\n");
51470298 5137 s->tried_pubkey_config = TRUE;
1408a877 5138 }
5139 /* Send a spurious AUTH_NONE to return to the top. */
51470298 5140 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5141 ssh2_pkt_addstring(ssh, s->username);
5142 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5143 ssh2_pkt_addstring(ssh, "none"); /* method */
5144 ssh2_pkt_send(ssh);
5145 s->type = AUTH_TYPE_NONE;
1408a877 5146 } else {
1dd353b5 5147 unsigned char *pkblob, *sigblob, *sigdata;
5148 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 5149 int p;
65a22376 5150
1408a877 5151 /*
5152 * We have loaded the private key and the server
5153 * has announced that it's willing to accept it.
5154 * Hallelujah. Generate a signature and send it.
5155 */
51470298 5156 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5157 ssh2_pkt_addstring(ssh, s->username);
5158 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5159 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5160 ssh2_pkt_addbool(ssh, TRUE);
5161 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 5162 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 5163 ssh2_pkt_addstring_start(ssh);
d8baa528 5164 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
1408a877 5165
5166 /*
5167 * The data to be signed is:
5168 *
5169 * string session-id
5170 *
5171 * followed by everything so far placed in the
5172 * outgoing packet.
5173 */
51470298 5174 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
dda87a28 5175 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5176 sigdata_len -= 4;
92d60585 5177 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 5178 p = 0;
5179 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5180 PUT_32BIT(sigdata+p, 20);
5181 p += 4;
5182 }
5183 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5184 memcpy(sigdata+p, ssh->pktout.data + 5,
51470298 5185 ssh->pktout.length - 5);
dda87a28 5186 p += ssh->pktout.length - 5;
5187 assert(p == sigdata_len);
d8baa528 5188 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 5189 sigdata_len, &sigblob_len);
51470298 5190 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 5191 sigblob, sigblob_len);
5192 sfree(pkblob);
5193 sfree(sigblob);
1408a877 5194 sfree(sigdata);
5195
51470298 5196 ssh2_pkt_send(ssh);
5197 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 5198 }
51470298 5199 } else if (s->method == AUTH_PASSWORD) {
65a22376 5200 /*
1408a877 5201 * We send the password packet lumped tightly together with
5202 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5203 * string long enough to make the total length of the two
5204 * packets constant. This should ensure that a passive
5205 * listener doing traffic analyis can't work out the length
5206 * of the password.
5207 *
5208 * For this to work, we need an assumption about the
5209 * maximum length of the password packet. I think 256 is
5210 * pretty conservative. Anyone using a password longer than
5211 * that probably doesn't have much to worry about from
5212 * people who find out how long their password is!
65a22376 5213 */
51470298 5214 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5215 ssh2_pkt_addstring(ssh, s->username);
5216 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5217 ssh2_pkt_addstring(ssh, "password");
5218 ssh2_pkt_addbool(ssh, FALSE);
5219 ssh2_pkt_addstring(ssh, s->password);
1409c1b3 5220 memset(s->password, 0, sizeof(s->password));
51470298 5221 ssh2_pkt_defer(ssh);
65a22376 5222 /*
1408a877 5223 * We'll include a string that's an exact multiple of the
5224 * cipher block size. If the cipher is NULL for some
5225 * reason, we don't do this trick at all because we gain
5226 * nothing by it.
65a22376 5227 */
51470298 5228 if (ssh->cscipher) {
32874aea 5229 int stringlen, i;
5230
51470298 5231 stringlen = (256 - ssh->deferred_len);
5232 stringlen += ssh->cscipher->blksize - 1;
5233 stringlen -= (stringlen % ssh->cscipher->blksize);
5234 if (ssh->cscomp) {
32874aea 5235 /*
5236 * Temporarily disable actual compression,
5237 * so we can guarantee to get this string
5238 * exactly the length we want it. The
5239 * compression-disabling routine should
5240 * return an integer indicating how many
5241 * bytes we should adjust our string length
5242 * by.
5243 */
5366aed8 5244 stringlen -=
5245 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 5246 }
51470298 5247 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5248 ssh2_pkt_addstring_start(ssh);
6e9e9520 5249 for (i = 0; i < stringlen; i++) {
32874aea 5250 char c = (char) random_byte();
51470298 5251 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 5252 }
51470298 5253 ssh2_pkt_defer(ssh);
65a22376 5254 }
51470298 5255 ssh_pkt_defersend(ssh);
0d43337a 5256 logevent("Sent password");
51470298 5257 s->type = AUTH_TYPE_PASSWORD;
5258 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5259 if (s->curr_prompt == 0) {
5260 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5261 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 5262 }
51470298 5263 if (s->need_pw) { /* only add pw if we just got one! */
5264 ssh2_pkt_addstring(ssh, s->password);
5265 memset(s->password, 0, sizeof(s->password));
5266 s->curr_prompt++;
45068b27 5267 }
51470298 5268 if (s->curr_prompt >= s->num_prompts) {
5269 ssh2_pkt_send(ssh);
45068b27 5270 } else {
5271 /*
5272 * If there are prompts remaining, we set
5273 * `gotit' so that we won't attempt to get
5274 * another packet. Then we go back round the
5275 * loop and will end up retrieving another
5276 * prompt out of the existing packet. Funky or
5277 * what?
5278 */
51470298 5279 s->gotit = TRUE;
45068b27 5280 }
51470298 5281 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5282 } else {
51470298 5283 c_write_str(ssh, "No supported authentication methods"
5284 " left to try!\r\n");
5285 logevent("No supported authentications offered."
5286 " Disconnecting");
5287 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5288 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5289 ssh2_pkt_addstring(ssh, "No supported authentication"
5290 " methods available");
5291 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5292 ssh2_pkt_send(ssh);
3bb2f322 5293 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5294 crStopV;
65a22376 5295 }
65a22376 5296 }
51470298 5297 } while (!s->we_are_in);
7cca0d81 5298
5299 /*
5300 * Now we're authenticated for the connection protocol. The
5301 * connection protocol will automatically have started at this
5302 * point; there's no need to send SERVICE_REQUEST.
5303 */
5304
5305 /*
5306 * So now create a channel with a session in it.
5307 */
51470298 5308 ssh->channels = newtree234(ssh_channelcmp);
3d88e64d 5309 ssh->mainchan = snew(struct ssh_channel);
51470298 5310 ssh->mainchan->ssh = ssh;
5311 ssh->mainchan->localid = alloc_channel_id(ssh);
5312 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5313 ssh2_pkt_addstring(ssh, "session");
5314 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5315 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5316 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5317 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5318 ssh2_pkt_send(ssh);
7cca0d81 5319 crWaitUntilV(ispkt);
51470298 5320 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6b5cf8b4 5321 bombout(("Server refused to open a session"));
7ffdbc1a 5322 crStopV;
32874aea 5323 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5324 }
51470298 5325 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
6b5cf8b4 5326 bombout(("Server's channel confirmation cited wrong channel"));
7ffdbc1a 5327 crStopV;
7cca0d81 5328 }
51470298 5329 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5330 ssh->mainchan->type = CHAN_MAINSESSION;
5331 ssh->mainchan->closes = 0;
5332 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5333 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5334 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5335 add234(ssh->channels, ssh->mainchan);
7cca0d81 5336 logevent("Opened channel for session");
5337
5338 /*
783415f8 5339 * Potentially enable X11 forwarding.
5340 */
86916870 5341 if (ssh->cfg.x11_forward) {
32874aea 5342 char proto[20], data[64];
5343 logevent("Requesting X11 forwarding");
302121de 5344 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5345 data, sizeof(data), ssh->cfg.x11_auth);
5346 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 5347 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5348 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5349 ssh2_pkt_addstring(ssh, "x11-req");
5350 ssh2_pkt_addbool(ssh, 1); /* want reply */
5351 ssh2_pkt_addbool(ssh, 0); /* many connections */
5352 ssh2_pkt_addstring(ssh, proto);
5353 ssh2_pkt_addstring(ssh, data);
86916870 5354 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
51470298 5355 ssh2_pkt_send(ssh);
32874aea 5356
5357 do {
5358 crWaitUntilV(ispkt);
51470298 5359 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5360 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5361 struct ssh_channel *c;
51470298 5362 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5363 if (!c)
5364 continue; /* nonexistent channel */
51470298 5365 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5366 }
51470298 5367 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5368
51470298 5369 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5370 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5371 bombout(("Unexpected response to X11 forwarding request:"
51470298 5372 " packet type %d", ssh->pktin.type));
7ffdbc1a 5373 crStopV;
32874aea 5374 }
5375 logevent("X11 forwarding refused");
5376 } else {
5377 logevent("X11 forwarding enabled");
51470298 5378 ssh->X11_fwd_enabled = TRUE;
32874aea 5379 }
783415f8 5380 }
5381
5382 /*
bc240b21 5383 * Enable port forwardings.
5384 */
5385 {
bc240b21 5386 char type;
5387 int n;
a4fc0d74 5388 int sport,dport,sserv,dserv;
6ee9b735 5389 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5390
51470298 5391 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5392 /* Add port forwardings. */
86916870 5393 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5394 while (*ssh->portfwd_strptr) {
5395 type = *ssh->portfwd_strptr++;
6ee9b735 5396 saddr[0] = '\0';
bc240b21 5397 n = 0;
6ee9b735 5398 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5399 if (*ssh->portfwd_strptr == ':') {
5400 /*
5401 * We've seen a colon in the middle of the
5402 * source port number. This means that
5403 * everything we've seen until now is the
5404 * source _address_, so we'll move it into
5405 * saddr and start sports from the beginning
5406 * again.
5407 */
5408 ssh->portfwd_strptr++;
5409 sports[n] = '\0';
5410 strcpy(saddr, sports);
5411 n = 0;
5412 }
5413 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5414 }
bc240b21 5415 sports[n] = 0;
820ebe3b 5416 if (type != 'D') {
5417 if (*ssh->portfwd_strptr == '\t')
5418 ssh->portfwd_strptr++;
5419 n = 0;
5420 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5421 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5422 }
5423 host[n] = 0;
5424 if (*ssh->portfwd_strptr == ':')
5425 ssh->portfwd_strptr++;
5426 n = 0;
5427 while (*ssh->portfwd_strptr) {
5428 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5429 }
5430 dports[n] = 0;
51470298 5431 ssh->portfwd_strptr++;
820ebe3b 5432 dport = atoi(dports);
5433 dserv = 0;
5434 if (dport == 0) {
5435 dserv = 1;
5436 dport = net_service_lookup(dports);
5437 if (!dport) {
5438 logeventf(ssh, "Service lookup failed for destination"
5439 " port \"%s\"", dports);
5440 }
a4fc0d74 5441 }
820ebe3b 5442 } else {
5443 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 5444 dport = dserv = -1;
7d5b0f4d 5445 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 5446 }
bc240b21 5447 sport = atoi(sports);
a4fc0d74 5448 sserv = 0;
5449 if (sport == 0) {
5450 sserv = 1;
68a49acb 5451 sport = net_service_lookup(sports);
5452 if (!sport) {
57356d63 5453 logeventf(ssh, "Service lookup failed for source"
5454 " port \"%s\"", sports);
a4fc0d74 5455 }
5456 }
bc240b21 5457 if (sport && dport) {
5458 if (type == 'L') {
6ee9b735 5459 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 5460 sport, ssh, &ssh->cfg);
6ee9b735 5461 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5462 " forwarding to %s:%.*s%.*s%d%.*s",
5463 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5464 (int)(*saddr?1:0), ":",
57356d63 5465 (int)(sserv ? strlen(sports) : 0), sports,
5466 sserv, "(", sport, sserv, ")",
5467 host,
5468 (int)(dserv ? strlen(dports) : 0), dports,
5469 dserv, "(", dport, dserv, ")");
820ebe3b 5470 } else if (type == 'D') {
5471 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5472 sport, ssh, &ssh->cfg);
5473 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5474 " doing SOCKS dynamic forwarding",
5475 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5476 (int)(*saddr?1:0), ":",
5477 (int)(sserv ? strlen(sports) : 0), sports,
5478 sserv, "(", sport, sserv, ")");
bc240b21 5479 } else {
5480 struct ssh_rportfwd *pf;
3d88e64d 5481 pf = snew(struct ssh_rportfwd);
bc240b21 5482 strcpy(pf->dhost, host);
5483 pf->dport = dport;
5484 pf->sport = sport;
51470298 5485 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5486 logeventf(ssh, "Duplicate remote port forwarding"
5487 " to %s:%d", host, dport);
bc240b21 5488 sfree(pf);
5489 } else {
6ee9b735 5490 logeventf(ssh, "Requesting remote port "
5491 "%.*s%.*s%.*s%.*s%d%.*s"
57356d63 5492 " forward to %s:%.*s%.*s%d%.*s",
6ee9b735 5493 (int)(*saddr?strlen(saddr):0),
5494 *saddr?saddr:NULL,
5495 (int)(*saddr?1:0), ":",
57356d63 5496 (int)(sserv ? strlen(sports) : 0), sports,
5497 sserv, "(", sport, sserv, ")",
5498 host,
5499 (int)(dserv ? strlen(dports) : 0), dports,
5500 dserv, "(", dport, dserv, ")");
51470298 5501 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5502 ssh2_pkt_addstring(ssh, "tcpip-forward");
5503 ssh2_pkt_addbool(ssh, 1);/* want reply */
6ee9b735 5504 if (*saddr)
5505 ssh2_pkt_addstring(ssh, saddr);
86916870 5506 if (ssh->cfg.rport_acceptall)
51470298 5507 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5508 else
51470298 5509 ssh2_pkt_addstring(ssh, "127.0.0.1");
5510 ssh2_pkt_adduint32(ssh, sport);
5511 ssh2_pkt_send(ssh);
bc240b21 5512
5513 do {
5514 crWaitUntilV(ispkt);
51470298 5515 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5516 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5517 struct ssh_channel *c;
51470298 5518 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5519 if (!c)
5520 continue;/* nonexistent channel */
51470298 5521 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5522 }
51470298 5523 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5524
51470298 5525 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5526 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 5527 bombout(("Unexpected response to port "
c9886e66 5528 "forwarding request: packet type %d",
51470298 5529 ssh->pktin.type));
7ffdbc1a 5530 crStopV;
bc240b21 5531 }
5532 logevent("Server refused this port forwarding");
5533 } else {
5534 logevent("Remote port forwarding enabled");
5535 }
5536 }
5537 }
5538 }
5539 }
5540 }
5541
5542 /*
36c2a3e9 5543 * Potentially enable agent forwarding.
5544 */
86916870 5545 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 5546 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5547 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5548 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5549 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5550 ssh2_pkt_addbool(ssh, 1); /* want reply */
5551 ssh2_pkt_send(ssh);
32874aea 5552
5553 do {
5554 crWaitUntilV(ispkt);
51470298 5555 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5556 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5557 struct ssh_channel *c;
51470298 5558 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5559 if (!c)
5560 continue; /* nonexistent channel */
51470298 5561 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5562 }
51470298 5563 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5564
51470298 5565 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5566 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5567 bombout(("Unexpected response to agent forwarding request:"
51470298 5568 " packet type %d", ssh->pktin.type));
7ffdbc1a 5569 crStopV;
32874aea 5570 }
5571 logevent("Agent forwarding refused");
5572 } else {
5573 logevent("Agent forwarding enabled");
51470298 5574 ssh->agentfwd_enabled = TRUE;
32874aea 5575 }
36c2a3e9 5576 }
5577
5578 /*
7cca0d81 5579 * Now allocate a pty for the session.
5580 */
86916870 5581 if (!ssh->cfg.nopty) {
51470298 5582 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5583 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5584 ssh2_pkt_addstring(ssh, "pty-req");
5585 ssh2_pkt_addbool(ssh, 1); /* want reply */
86916870 5586 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
51470298 5587 ssh2_pkt_adduint32(ssh, ssh->term_width);
5588 ssh2_pkt_adduint32(ssh, ssh->term_height);
5589 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5590 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5591 ssh2_pkt_addstring_start(ssh);
5592 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5593 ssh2_pkt_send(ssh);
5594 ssh->state = SSH_STATE_INTERMED;
32874aea 5595
5596 do {
5597 crWaitUntilV(ispkt);
51470298 5598 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);
32874aea 5602 if (!c)
5603 continue; /* nonexistent channel */
51470298 5604 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5605 }
51470298 5606 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5607
51470298 5608 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5609 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5610 bombout(("Unexpected response to pty request:"
51470298 5611 " packet type %d", ssh->pktin.type));
7ffdbc1a 5612 crStopV;
32874aea 5613 }
51470298 5614 c_write_str(ssh, "Server refused to allocate pty\r\n");
5615 ssh->editing = ssh->echoing = 1;
32874aea 5616 } else {
5617 logevent("Allocated pty");
5618 }
0965bee0 5619 } else {
51470298 5620 ssh->editing = ssh->echoing = 1;
7cca0d81 5621 }
5622
5623 /*
fd5e5847 5624 * Start a shell or a remote command. We may have to attempt
5625 * this twice if the config data has provided a second choice
5626 * of command.
7cca0d81 5627 */
fd5e5847 5628 while (1) {
5629 int subsys;
5630 char *cmd;
5631
51470298 5632 if (ssh->fallback_cmd) {
86916870 5633 subsys = ssh->cfg.ssh_subsys2;
5634 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 5635 } else {
86916870 5636 subsys = ssh->cfg.ssh_subsys;
5637 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 5638 }
5639
51470298 5640 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5641 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5642 if (subsys) {
51470298 5643 ssh2_pkt_addstring(ssh, "subsystem");
5644 ssh2_pkt_addbool(ssh, 1); /* want reply */
5645 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5646 } else if (*cmd) {
51470298 5647 ssh2_pkt_addstring(ssh, "exec");
5648 ssh2_pkt_addbool(ssh, 1); /* want reply */
5649 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5650 } else {
51470298 5651 ssh2_pkt_addstring(ssh, "shell");
5652 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5653 }
51470298 5654 ssh2_pkt_send(ssh);
fd5e5847 5655 do {
5656 crWaitUntilV(ispkt);
51470298 5657 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5658 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5659 struct ssh_channel *c;
51470298 5660 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5661 if (!c)
5662 continue; /* nonexistent channel */
51470298 5663 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5664 }
51470298 5665 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5666 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5667 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5668 bombout(("Unexpected response to shell/command request:"
51470298 5669 " packet type %d", ssh->pktin.type));
7ffdbc1a 5670 crStopV;
fd5e5847 5671 }
5672 /*
5673 * We failed to start the command. If this is the
5674 * fallback command, we really are finished; if it's
5675 * not, and if the fallback command exists, try falling
5676 * back to it before complaining.
5677 */
86916870 5678 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5679 logevent("Primary command failed; attempting fallback");
51470298 5680 ssh->fallback_cmd = TRUE;
fd5e5847 5681 continue;
5682 }
6b5cf8b4 5683 bombout(("Server refused to start a shell/command"));
7ffdbc1a 5684 crStopV;
fd5e5847 5685 } else {
5686 logevent("Started a shell/command");
32874aea 5687 }
fd5e5847 5688 break;
7cca0d81 5689 }
5690
51470298 5691 ssh->state = SSH_STATE_SESSION;
5692 if (ssh->size_needed)
5693 ssh_size(ssh, ssh->term_width, ssh->term_height);
5694 if (ssh->eof_needed)
5695 ssh_special(ssh, TS_EOF);
6e48c3fe 5696
7cca0d81 5697 /*
5698 * Transfer data!
5699 */
b9d7bcad 5700 if (ssh->ldisc)
5701 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5702 ssh->send_ok = 1;
7cca0d81 5703 while (1) {
e5574168 5704 crReturnV;
51470298 5705 s->try_send = FALSE;
7cca0d81 5706 if (ispkt) {
51470298 5707 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5708 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5709 char *data;
5710 int length;
51470298 5711 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5712 struct ssh_channel *c;
51470298 5713 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5714 if (!c)
5715 continue; /* nonexistent channel */
51470298 5716 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5717 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5718 continue; /* extended but not stderr */
51470298 5719 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5720 if (data) {
7ffdbc1a 5721 int bufsize = 0;
5471d09a 5722 c->v.v2.locwindow -= length;
32874aea 5723 switch (c->type) {
5724 case CHAN_MAINSESSION:
5471d09a 5725 bufsize =
51470298 5726 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5727 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5728 data, length);
32874aea 5729 break;
5730 case CHAN_X11:
5471d09a 5731 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5732 break;
d74d141c 5733 case CHAN_SOCKDATA:
5471d09a 5734 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5735 break;
36c2a3e9 5736 case CHAN_AGENT:
32874aea 5737 while (length > 0) {
5738 if (c->u.a.lensofar < 4) {
5739 int l = min(4 - c->u.a.lensofar, length);
5740 memcpy(c->u.a.msglen + c->u.a.lensofar,
5741 data, l);
5742 data += l;
5743 length -= l;
5744 c->u.a.lensofar += l;
5745 }
5746 if (c->u.a.lensofar == 4) {
5747 c->u.a.totallen =
5748 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 5749 c->u.a.message = snewn(c->u.a.totallen,
5750 unsigned char);
32874aea 5751 memcpy(c->u.a.message, c->u.a.msglen, 4);
5752 }
5753 if (c->u.a.lensofar >= 4 && length > 0) {
5754 int l =
5755 min(c->u.a.totallen - c->u.a.lensofar,
5756 length);
5757 memcpy(c->u.a.message + c->u.a.lensofar,
5758 data, l);
5759 data += l;
5760 length -= l;
5761 c->u.a.lensofar += l;
5762 }
5763 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 5764 void *reply;
32874aea 5765 int replylen;
839f10db 5766 if (agent_query(c->u.a.message,
5767 c->u.a.totallen,
5768 &reply, &replylen,
5769 ssh_agentf_callback, c))
5770 ssh_agentf_callback(c, reply, replylen);
32874aea 5771 sfree(c->u.a.message);
5772 c->u.a.lensofar = 0;
5773 }
5774 }
5471d09a 5775 bufsize = 0;
32874aea 5776 break;
5777 }
5778 /*
5471d09a 5779 * If we are not buffering too much data,
5780 * enlarge the window again at the remote side.
32874aea 5781 */
5471d09a 5782 if (bufsize < OUR_V2_WINSIZE)
5783 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5784 }
51470298 5785 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5786 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5787 struct ssh_channel *c;
5788
51470298 5789 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5790 if (!c)
5791 continue; /* nonexistent channel */
5792
5793 if (c->type == CHAN_X11) {
5794 /*
5795 * Remote EOF on an X11 channel means we should
5796 * wrap up and close the channel ourselves.
5797 */
5798 x11_close(c->u.x11.s);
5799 sshfwd_close(c);
5800 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5801 sshfwd_close(c);
d74d141c 5802 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5803 pfd_close(c->u.pfd.s);
5804 sshfwd_close(c);
36c2a3e9 5805 }
51470298 5806 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5807 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5808 struct ssh_channel *c;
5809
51470298 5810 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5811 if (!c || ((int)c->remoteid) == -1) {
6b5cf8b4 5812 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 5813 c ? "half-open" : "nonexistent", i));
7ffdbc1a 5814 crStopV;
d0d844c1 5815 }
32874aea 5816 /* Do pre-close processing on the channel. */
5817 switch (c->type) {
5818 case CHAN_MAINSESSION:
5819 break; /* nothing to see here, move along */
5820 case CHAN_X11:
92f157bd 5821 if (c->u.x11.s != NULL)
5822 x11_close(c->u.x11.s);
5823 sshfwd_close(c);
32874aea 5824 break;
5825 case CHAN_AGENT:
92f157bd 5826 sshfwd_close(c);
32874aea 5827 break;
d74d141c 5828 case CHAN_SOCKDATA:
92f157bd 5829 if (c->u.pfd.s != NULL)
5830 pfd_close(c->u.pfd.s);
5831 sshfwd_close(c);
bc240b21 5832 break;
32874aea 5833 }
92f157bd 5834 if (c->closes == 0) {
51470298 5835 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5836 ssh2_pkt_adduint32(ssh, c->remoteid);
5837 ssh2_pkt_send(ssh);
92f157bd 5838 }
51470298 5839 del234(ssh->channels, c);
5471d09a 5840 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5841 sfree(c);
5842
5843 /*
5844 * See if that was the last channel left open.
5845 */
51470298 5846 if (count234(ssh->channels) == 0) {
3bb2f322 5847 logevent("All channels closed. Disconnecting");
ca2914d1 5848#if 0
5849 /*
5850 * We used to send SSH_MSG_DISCONNECT here,
5851 * because I'd believed that _every_ conforming
5852 * SSH2 connection had to end with a disconnect
5853 * being sent by at least one side; apparently
5854 * I was wrong and it's perfectly OK to
5855 * unceremoniously slam the connection shut
5856 * when you're done, and indeed OpenSSH feels
5857 * this is more polite than sending a
5858 * DISCONNECT. So now we don't.
5859 */
51470298 5860 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5861 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5862 ssh2_pkt_addstring(ssh, "All open channels closed");
5863 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5864 ssh2_pkt_send(ssh);
ca2914d1 5865#endif
3bb2f322 5866 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5867 crStopV;
32874aea 5868 }
5869 continue; /* remote sends close; ignore (FIXME) */
51470298 5870 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5871 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5872 struct ssh_channel *c;
51470298 5873 c = find234(ssh->channels, &i, ssh_channelfind);
a6253970 5874 if (!c || c->closes)
5875 continue; /* nonexistent or closing channel */
51470298 5876 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5877 s->try_send = TRUE;
5878 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5879 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5880 struct ssh_channel *c;
51470298 5881 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5882 if (!c)
5883 continue; /* nonexistent channel */
5884 if (c->type != CHAN_SOCKDATA_DORMANT)
5885 continue; /* dunno why they're confirming this */
51470298 5886 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5887 c->type = CHAN_SOCKDATA;
51470298 5888 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5889 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5890 if (c->u.pfd.s)
5891 pfd_confirm(c->u.pfd.s);
5892 if (c->closes) {
5893 /*
5894 * We have a pending close on this channel,
5895 * which we decided on before the server acked
5896 * the channel open. So now we know the
5897 * remoteid, we can close it again.
5898 */
51470298 5899 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5900 ssh2_pkt_adduint32(ssh, c->remoteid);
5901 ssh2_pkt_send(ssh);
4ed34d25 5902 }
51470298 5903 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5904 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5905 struct ssh_channel *c;
51470298 5906 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5907 if (!c)
5908 continue; /* nonexistent channel */
5909 if (c->type != CHAN_SOCKDATA_DORMANT)
5910 continue; /* dunno why they're failing this */
5911
5912 logevent("Forwarded connection refused by server");
5913
5914 pfd_close(c->u.pfd.s);
5915
51470298 5916 del234(ssh->channels, c);
724cface 5917 sfree(c);
51470298 5918 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5919 unsigned localid;
5920 char *type;
5921 int typelen, want_reply;
5922 struct ssh_channel *c;
5923
51470298 5924 localid = ssh2_pkt_getuint32(ssh);
5925 ssh2_pkt_getstring(ssh, &type, &typelen);
5926 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5927
5928 /*
5929 * First, check that the channel exists. Otherwise,
5930 * we can instantly disconnect with a rude message.
5931 */
51470298 5932 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5933 if (!c) {
5934 char buf[80];
5935 sprintf(buf, "Received channel request for nonexistent"
5936 " channel %d", localid);
5937 logevent(buf);
51470298 5938 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5939 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5940 ssh2_pkt_addstring(ssh, buf);
5941 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5942 ssh2_pkt_send(ssh);
6b5cf8b4 5943 connection_fatal(ssh->frontend, "%s", buf);
3bb2f322 5944 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5945 crStopV;
ebb0a590 5946 }
5947
5948 /*
d8d6c7e5 5949 * Having got the channel number, we now look at
5950 * the request type string to see if it's something
5951 * we recognise.
ebb0a590 5952 */
d8d6c7e5 5953 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5954 c == ssh->mainchan) {
d8d6c7e5 5955 /* We recognise "exit-status" on the primary channel. */
5956 char buf[100];
51470298 5957 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5958 sprintf(buf, "Server sent command exit status %d",
51470298 5959 ssh->exitcode);
d8d6c7e5 5960 logevent(buf);
5961 if (want_reply) {
51470298 5962 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5963 ssh2_pkt_adduint32(ssh, c->remoteid);
5964 ssh2_pkt_send(ssh);
d8d6c7e5 5965 }
5966 } else {
5967 /*
5968 * This is a channel request we don't know
5969 * about, so we now either ignore the request
5970 * or respond with CHANNEL_FAILURE, depending
5971 * on want_reply.
5972 */
5973 if (want_reply) {
51470298 5974 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5975 ssh2_pkt_adduint32(ssh, c->remoteid);
5976 ssh2_pkt_send(ssh);
d8d6c7e5 5977 }
ebb0a590 5978 }
51470298 5979 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5980 char *type;
5981 int typelen, want_reply;
5982
51470298 5983 ssh2_pkt_getstring(ssh, &type, &typelen);
5984 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5985
5986 /*
5987 * We currently don't support any global requests
5988 * at all, so we either ignore the request or
5989 * respond with REQUEST_FAILURE, depending on
5990 * want_reply.
5991 */
5992 if (want_reply) {
51470298 5993 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5994 ssh2_pkt_send(ssh);
697d4856 5995 }
51470298 5996 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5997 char *type;
5998 int typelen;
b3ebaa28 5999 char *peeraddr;
6000 int peeraddrlen;
2e5b14c0 6001 int peerport;
32874aea 6002 char *error = NULL;
6003 struct ssh_channel *c;
bc240b21 6004 unsigned remid, winsize, pktsize;
51470298 6005 ssh2_pkt_getstring(ssh, &type, &typelen);
3d88e64d 6006 c = snew(struct ssh_channel);
51470298 6007 c->ssh = ssh;
32874aea 6008
51470298 6009 remid = ssh2_pkt_getuint32(ssh);
6010 winsize = ssh2_pkt_getuint32(ssh);
6011 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 6012
32874aea 6013 if (typelen == 3 && !memcmp(type, "x11", 3)) {
df85f78b 6014 char *addrstr;
6015
6016 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6017 addrstr = snewn(peeraddrlen+1, char);
b3ebaa28 6018 memcpy(addrstr, peeraddr, peeraddrlen);
6019 peeraddr[peeraddrlen] = '\0';
2e5b14c0 6020 peerport = ssh2_pkt_getuint32(ssh);
b3ebaa28 6021
51470298 6022 if (!ssh->X11_fwd_enabled)
32874aea 6023 error = "X11 forwarding is not enabled";
86916870 6024 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
2e5b14c0 6025 ssh->x11auth, addrstr, peerport,
e8fa8f62 6026 &ssh->cfg) != NULL) {
32874aea 6027 error = "Unable to open an X11 connection";
6028 } else {
6029 c->type = CHAN_X11;
6030 }
b3ebaa28 6031
6032 sfree(addrstr);
bc240b21 6033 } else if (typelen == 15 &&
6034 !memcmp(type, "forwarded-tcpip", 15)) {
6035 struct ssh_rportfwd pf, *realpf;
6036 char *dummy;
6037 int dummylen;
51470298 6038 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6039 pf.sport = ssh2_pkt_getuint32(ssh);
2e5b14c0 6040 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6041 peerport = ssh2_pkt_getuint32(ssh);
51470298 6042 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 6043 if (realpf == NULL) {
6044 error = "Remote port is not recognised";
6045 } else {
cbe2d68f 6046 const char *e = pfd_newconnect(&c->u.pfd.s,
6047 realpf->dhost,
6048 realpf->dport, c,
6049 &ssh->cfg);
57356d63 6050 logeventf(ssh, "Received remote port open request"
6051 " for %s:%d", realpf->dhost, realpf->dport);
bc240b21 6052 if (e != NULL) {
57356d63 6053 logeventf(ssh, "Port open failed: %s", e);
bc240b21 6054 error = "Port open failed";
6055 } else {
6056 logevent("Forwarded port opened successfully");
6057 c->type = CHAN_SOCKDATA;
6058 }
6059 }
32874aea 6060 } else if (typelen == 22 &&
36c2a3e9 6061 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 6062 if (!ssh->agentfwd_enabled)
32874aea 6063 error = "Agent forwarding is not enabled";
36c2a3e9 6064 else {
32874aea 6065 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 6066 c->u.a.lensofar = 0;
32874aea 6067 }
6068 } else {
6069 error = "Unsupported channel type requested";
6070 }
6071
bc240b21 6072 c->remoteid = remid;
32874aea 6073 if (error) {
51470298 6074 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6075 ssh2_pkt_adduint32(ssh, c->remoteid);
6076 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6077 ssh2_pkt_addstring(ssh, error);
6078 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6079 ssh2_pkt_send(ssh);
32874aea 6080 sfree(c);
6081 } else {
51470298 6082 c->localid = alloc_channel_id(ssh);
32874aea 6083 c->closes = 0;
5471d09a 6084 c->v.v2.locwindow = OUR_V2_WINSIZE;
6085 c->v.v2.remwindow = winsize;
6086 c->v.v2.remmaxpkt = pktsize;
6087 bufchain_init(&c->v.v2.outbuffer);
51470298 6088 add234(ssh->channels, c);
6089 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6090 ssh2_pkt_adduint32(ssh, c->remoteid);
6091 ssh2_pkt_adduint32(ssh, c->localid);
6092 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6093 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6094 ssh2_pkt_send(ssh);
32874aea 6095 }
7cca0d81 6096 } else {
6b5cf8b4 6097 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 6098 crStopV;
7cca0d81 6099 }
6100 } else {
32874aea 6101 /*
6102 * We have spare data. Add it to the channel buffer.
6103 */
d8baa528 6104 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6105 s->try_send = TRUE;
32874aea 6106 }
51470298 6107 if (s->try_send) {
32874aea 6108 int i;
6109 struct ssh_channel *c;
6110 /*
6111 * Try to send data on all channels if we can.
6112 */
51470298 6113 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6114 int bufsize;
6115 if (c->closes)
6116 continue; /* don't send on closing channels */
6117 bufsize = ssh2_try_send(c);
5471d09a 6118 if (bufsize == 0) {
6119 switch (c->type) {
6120 case CHAN_MAINSESSION:
6121 /* stdin need not receive an unthrottle
6122 * notification since it will be polled */
6123 break;
6124 case CHAN_X11:
6125 x11_unthrottle(c->u.x11.s);
6126 break;
6127 case CHAN_AGENT:
6128 /* agent sockets are request/response and need no
6129 * buffer management */
6130 break;
6131 case CHAN_SOCKDATA:
6132 pfd_unthrottle(c->u.pfd.s);
6133 break;
6134 }
6135 }
6136 }
7cca0d81 6137 }
e5574168 6138 }
6139
6140 crFinishV;
6141}
6142
6143/*
7cca0d81 6144 * Handle the top-level SSH2 protocol.
6145 */
51470298 6146static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 6147{
51470298 6148 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 6149 return;
51470298 6150 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 6151}
6152
6153/*
8df7a775 6154 * Called to set up the connection.
374330e2 6155 *
6156 * Returns an error message, or NULL on success.
374330e2 6157 */
cbe2d68f 6158static const char *ssh_init(void *frontend_handle, void **backend_handle,
6159 Config *cfg,
6160 char *host, int port, char **realhost, int nodelay)
32874aea 6161{
cbe2d68f 6162 const char *p;
51470298 6163 Ssh ssh;
6164
3d88e64d 6165 ssh = snew(struct ssh_tag);
86916870 6166 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 6167 ssh->version = 0; /* when not ready yet */
51470298 6168 ssh->s = NULL;
6169 ssh->cipher = NULL;
371e569c 6170 ssh->v1_cipher_ctx = NULL;
0183b242 6171 ssh->crcda_ctx = NULL;
51470298 6172 ssh->cscipher = NULL;
371e569c 6173 ssh->cs_cipher_ctx = NULL;
51470298 6174 ssh->sccipher = NULL;
371e569c 6175 ssh->sc_cipher_ctx = NULL;
51470298 6176 ssh->csmac = NULL;
a8327734 6177 ssh->cs_mac_ctx = NULL;
51470298 6178 ssh->scmac = NULL;
e0e1a00d 6179 ssh->sc_mac_ctx = NULL;
51470298 6180 ssh->cscomp = NULL;
5366aed8 6181 ssh->cs_comp_ctx = NULL;
51470298 6182 ssh->sccomp = NULL;
5366aed8 6183 ssh->sc_comp_ctx = NULL;
51470298 6184 ssh->kex = NULL;
389aa499 6185 ssh->kex_ctx = NULL;
51470298 6186 ssh->hostkey = NULL;
6187 ssh->exitcode = -1;
6188 ssh->state = SSH_STATE_PREPACKET;
6189 ssh->size_needed = FALSE;
6190 ssh->eof_needed = FALSE;
b9d7bcad 6191 ssh->ldisc = NULL;
a8327734 6192 ssh->logctx = NULL;
51470298 6193 {
6194 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6195 ssh->pktin = ssh->pktout = empty;
6196 }
6197 ssh->deferred_send_data = NULL;
6198 ssh->deferred_len = 0;
6199 ssh->deferred_size = 0;
6200 ssh->fallback_cmd = 0;
6201 ssh->pkt_ctx = 0;
302121de 6202 ssh->x11auth = NULL;
be738459 6203 ssh->v1_compressing = FALSE;
51470298 6204 ssh->v2_outgoing_sequence = 0;
6205 ssh->ssh1_rdpkt_crstate = 0;
6206 ssh->ssh2_rdpkt_crstate = 0;
6207 ssh->do_ssh_init_crstate = 0;
6208 ssh->ssh_gotdata_crstate = 0;
6209 ssh->ssh1_protocol_crstate = 0;
6210 ssh->do_ssh1_login_crstate = 0;
6211 ssh->do_ssh2_transport_crstate = 0;
6212 ssh->do_ssh2_authconn_crstate = 0;
6213 ssh->do_ssh_init_state = NULL;
6214 ssh->do_ssh1_login_state = NULL;
6215 ssh->do_ssh2_transport_state = NULL;
6216 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 6217 ssh->mainchan = NULL;
968d2d92 6218 ssh->throttled_all = 0;
6219 ssh->v1_stdout_throttling = 0;
51470298 6220
6221 *backend_handle = ssh;
32874aea 6222
8f203108 6223#ifdef MSCRYPTOAPI
32874aea 6224 if (crypto_startup() == 0)
8f203108 6225 return "Microsoft high encryption pack not installed!";
6226#endif
374330e2 6227
51470298 6228 ssh->frontend = frontend_handle;
86916870 6229 ssh->term_width = ssh->cfg.width;
6230 ssh->term_height = ssh->cfg.height;
887035a5 6231
fabd1805 6232 ssh->channels = NULL;
6233 ssh->rportfwds = NULL;
6234
51470298 6235 ssh->send_ok = 0;
6236 ssh->editing = 0;
6237 ssh->echoing = 0;
6238 ssh->v1_throttle_count = 0;
6239 ssh->overall_bufsize = 0;
6240 ssh->fallback_cmd = 0;
8df7a775 6241
3648d4c5 6242 ssh->protocol = NULL;
6243
51470298 6244 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 6245 if (p != NULL)
6246 return p;
374330e2 6247
374330e2 6248 return NULL;
6249}
6250
fabd1805 6251static void ssh_free(void *handle)
6252{
6253 Ssh ssh = (Ssh) handle;
6254 struct ssh_channel *c;
6255 struct ssh_rportfwd *pf;
6256
6257 if (ssh->v1_cipher_ctx)
6258 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6259 if (ssh->cs_cipher_ctx)
6260 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6261 if (ssh->sc_cipher_ctx)
6262 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6263 if (ssh->cs_mac_ctx)
6264 ssh->csmac->free_context(ssh->cs_mac_ctx);
6265 if (ssh->sc_mac_ctx)
6266 ssh->scmac->free_context(ssh->sc_mac_ctx);
6267 if (ssh->cs_comp_ctx)
6268 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6269 if (ssh->sc_comp_ctx)
6270 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6271 if (ssh->kex_ctx)
6272 dh_cleanup(ssh->kex_ctx);
6273 sfree(ssh->savedhost);
6274
6275 if (ssh->channels) {
6276 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6277 switch (c->type) {
6278 case CHAN_X11:
6279 if (c->u.x11.s != NULL)
6280 x11_close(c->u.x11.s);
6281 break;
6282 case CHAN_SOCKDATA:
6283 if (c->u.pfd.s != NULL)
6284 pfd_close(c->u.pfd.s);
6285 break;
6286 }
6287 sfree(c);
6288 }
6289 freetree234(ssh->channels);
6290 }
6291
6292 if (ssh->rportfwds) {
6293 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6294 sfree(pf);
6295 freetree234(ssh->rportfwds);
6296 }
6297 sfree(ssh->deferred_send_data);
6298 if (ssh->x11auth)
6299 x11_free_auth(ssh->x11auth);
6300 sfree(ssh->do_ssh_init_state);
6301 sfree(ssh->do_ssh1_login_state);
6302 sfree(ssh->do_ssh2_transport_state);
6303 sfree(ssh->do_ssh2_authconn_state);
679539d7 6304 if (ssh->pktout.data) {
6305 sfree(ssh->pktout.data);
6306 ssh->pktout.data = NULL;
6307 }
6308 if (ssh->pktin.data) {
6309 sfree(ssh->pktin.data);
6310 ssh->pktin.data = NULL;
6311 }
6312 if (ssh->crcda_ctx) {
6313 crcda_free_context(ssh->crcda_ctx);
6314 ssh->crcda_ctx = NULL;
6315 }
6316 if (ssh->logctx) {
6317 log_free(ssh->logctx);
6318 ssh->logctx = NULL;
6319 }
fabd1805 6320 if (ssh->s)
36f94d1f 6321 ssh_do_close(ssh);
fabd1805 6322 sfree(ssh);
6323}
6324
374330e2 6325/*
86916870 6326 * Reconfigure the SSH backend.
6327 *
6328 * Currently, this function does nothing very useful. In future,
6329 * however, we could do some handy things with it. For example, we
6330 * could make the port forwarding configurer active in the Change
6331 * Settings box, and this routine could close down existing
6332 * forwardings and open up new ones in response to changes.
6333 */
6334static void ssh_reconfig(void *handle, Config *cfg)
6335{
6336 Ssh ssh = (Ssh) handle;
6337 ssh->cfg = *cfg; /* STRUCTURE COPY */
6338}
6339
6340/*
374330e2 6341 * Called to send data down the Telnet connection.
6342 */
51470298 6343static int ssh_send(void *handle, char *buf, int len)
32874aea 6344{
51470298 6345 Ssh ssh = (Ssh) handle;
6346
6347 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6348 return 0;
374330e2 6349
d8baa528 6350 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 6351
51470298 6352 return ssh_sendbuffer(ssh);
5471d09a 6353}
6354
6355/*
6356 * Called to query the current amount of buffered stdin data.
6357 */
51470298 6358static int ssh_sendbuffer(void *handle)
5471d09a 6359{
51470298 6360 Ssh ssh = (Ssh) handle;
5471d09a 6361 int override_value;
6362
51470298 6363 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6364 return 0;
6365
6366 /*
6367 * If the SSH socket itself has backed up, add the total backup
6368 * size on that to any individual buffer on the stdin channel.
6369 */
6370 override_value = 0;
51470298 6371 if (ssh->throttled_all)
6372 override_value = ssh->overall_bufsize;
5471d09a 6373
51470298 6374 if (ssh->version == 1) {
5471d09a 6375 return override_value;
51470298 6376 } else if (ssh->version == 2) {
6377 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 6378 return override_value;
6379 else
51470298 6380 return (override_value +
6381 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 6382 }
6383
6384 return 0;
374330e2 6385}
6386
6387/*
6e48c3fe 6388 * Called to set the size of the window from SSH's POV.
374330e2 6389 */
51470298 6390static void ssh_size(void *handle, int width, int height)
32874aea 6391{
51470298 6392 Ssh ssh = (Ssh) handle;
6393
6394 ssh->term_width = width;
6395 ssh->term_height = height;
f278d6f8 6396
51470298 6397 switch (ssh->state) {
374330e2 6398 case SSH_STATE_BEFORE_SIZE:
3687d221 6399 case SSH_STATE_PREPACKET:
21248260 6400 case SSH_STATE_CLOSED:
374330e2 6401 break; /* do nothing */
6402 case SSH_STATE_INTERMED:
51470298 6403 ssh->size_needed = TRUE; /* buffer for later */
374330e2 6404 break;
6405 case SSH_STATE_SESSION:
86916870 6406 if (!ssh->cfg.nopty) {
51470298 6407 if (ssh->version == 1) {
6408 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6409 PKT_INT, ssh->term_height,
6410 PKT_INT, ssh->term_width,
32874aea 6411 PKT_INT, 0, PKT_INT, 0, PKT_END);
6412 } else {
51470298 6413 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6414 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6415 ssh2_pkt_addstring(ssh, "window-change");
6416 ssh2_pkt_addbool(ssh, 0);
6417 ssh2_pkt_adduint32(ssh, ssh->term_width);
6418 ssh2_pkt_adduint32(ssh, ssh->term_height);
6419 ssh2_pkt_adduint32(ssh, 0);
6420 ssh2_pkt_adduint32(ssh, 0);
6421 ssh2_pkt_send(ssh);
32874aea 6422 }
6423 }
6424 break;
374330e2 6425 }
6426}
6427
6428/*
125105d1 6429 * Return a list of the special codes that make sense in this
6430 * protocol.
6431 */
6432static const struct telnet_special *ssh_get_specials(void *handle)
6433{
6434 Ssh ssh = (Ssh) handle;
6435
6436 if (ssh->version == 1) {
6437 static const struct telnet_special ssh1_specials[] = {
6438 {"IGNORE message", TS_NOP},
6439 {NULL, 0}
6440 };
6441 return ssh1_specials;
6442 } else if (ssh->version == 2) {
6443 static const struct telnet_special ssh2_specials[] = {
6444 {"Break", TS_BRK},
6445 {"IGNORE message", TS_NOP},
6446 {NULL, 0}
6447 };
6448 return ssh2_specials;
6449 } else
6450 return NULL;
6451}
6452
6453/*
6abbf9e3 6454 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6455 * can send an EOF and collect resulting output (e.g. `plink
6456 * hostname sort').
374330e2 6457 */
51470298 6458static void ssh_special(void *handle, Telnet_Special code)
32874aea 6459{
51470298 6460 Ssh ssh = (Ssh) handle;
6461
6abbf9e3 6462 if (code == TS_EOF) {
51470298 6463 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6464 /*
6465 * Buffer the EOF in case we are pre-SESSION, so we can
6466 * send it as soon as we reach SESSION.
6467 */
6468 if (code == TS_EOF)
51470298 6469 ssh->eof_needed = TRUE;
32874aea 6470 return;
6471 }
51470298 6472 if (ssh->version == 1) {
6473 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6474 } else {
51470298 6475 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6476 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6477 ssh2_pkt_send(ssh);
32874aea 6478 }
6479 logevent("Sent EOF message");
125105d1 6480 } else if (code == TS_PING || code == TS_NOP) {
51470298 6481 if (ssh->state == SSH_STATE_CLOSED
6482 || ssh->state == SSH_STATE_PREPACKET) return;
6483 if (ssh->version == 1) {
6484 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6485 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6486 } else {
51470298 6487 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6488 ssh2_pkt_addstring_start(ssh);
6489 ssh2_pkt_send(ssh);
32874aea 6490 }
125105d1 6491 } else if (code == TS_BRK) {
6492 if (ssh->state == SSH_STATE_CLOSED
6493 || ssh->state == SSH_STATE_PREPACKET) return;
6494 if (ssh->version == 1) {
6495 logevent("Unable to send BREAK signal in SSH1");
6496 } else {
6497 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6498 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6499 ssh2_pkt_addstring(ssh, "break");
6500 ssh2_pkt_addbool(ssh, 0);
6501 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6502 ssh2_pkt_send(ssh);
6503 }
6abbf9e3 6504 } else {
32874aea 6505 /* do nothing */
6abbf9e3 6506 }
374330e2 6507}
6508
51470298 6509void *new_sock_channel(void *handle, Socket s)
d74d141c 6510{
51470298 6511 Ssh ssh = (Ssh) handle;
d74d141c 6512 struct ssh_channel *c;
3d88e64d 6513 c = snew(struct ssh_channel);
51470298 6514 c->ssh = ssh;
d74d141c 6515
6516 if (c) {
bc240b21 6517 c->remoteid = -1; /* to be set when open confirmed */
51470298 6518 c->localid = alloc_channel_id(ssh);
d74d141c 6519 c->closes = 0;
bc240b21 6520 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6521 c->u.pfd.s = s;
013dd8c0 6522 bufchain_init(&c->v.v2.outbuffer);
51470298 6523 add234(ssh->channels, c);
d74d141c 6524 }
6525 return c;
6526}
6527
5471d09a 6528/*
6529 * This is called when stdout/stderr (the entity to which
6530 * from_backend sends data) manages to clear some backlog.
6531 */
ae9ae89f 6532static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6533{
51470298 6534 Ssh ssh = (Ssh) handle;
6535 if (ssh->version == 1) {
6536 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6537 ssh->v1_stdout_throttling = 0;
6538 ssh1_throttle(ssh, -1);
5471d09a 6539 }
6540 } else {
51470298 6541 if (ssh->mainchan && ssh->mainchan->closes == 0)
6542 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6543 }
6544}
6545
6b78788a 6546void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6547{
6548 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6549 Ssh ssh = c->ssh;
d74d141c 6550
57356d63 6551 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 6552
51470298 6553 if (ssh->version == 1) {
6554 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6555 PKT_INT, c->localid,
6556 PKT_STR, hostname,
6557 PKT_INT, port,
6558 //PKT_STR, <org:orgport>,
6559 PKT_END);
6560 } else {
51470298 6561 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6562 ssh2_pkt_addstring(ssh, "direct-tcpip");
6563 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6564 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6565 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6566 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6567 ssh2_pkt_addstring(ssh, hostname);
6568 ssh2_pkt_adduint32(ssh, port);
bc240b21 6569 /*
6570 * We make up values for the originator data; partly it's
6571 * too much hassle to keep track, and partly I'm not
6572 * convinced the server should be told details like that
6573 * about my local network configuration.
6574 */
51470298 6575 ssh2_pkt_addstring(ssh, "client-side-connection");
6576 ssh2_pkt_adduint32(ssh, 0);
6577 ssh2_pkt_send(ssh);
bc240b21 6578 }
d74d141c 6579}
6580
6581
51470298 6582static Socket ssh_socket(void *handle)
32874aea 6583{
51470298 6584 Ssh ssh = (Ssh) handle;
6585 return ssh->s;
32874aea 6586}
8ccc75b0 6587
51470298 6588static int ssh_sendok(void *handle)
32874aea 6589{
51470298 6590 Ssh ssh = (Ssh) handle;
6591 return ssh->send_ok;
32874aea 6592}
fb09bf1c 6593
51470298 6594static int ssh_ldisc(void *handle, int option)
32874aea 6595{
51470298 6596 Ssh ssh = (Ssh) handle;
32874aea 6597 if (option == LD_ECHO)
51470298 6598 return ssh->echoing;
32874aea 6599 if (option == LD_EDIT)
51470298 6600 return ssh->editing;
0965bee0 6601 return FALSE;
6602}
6603
b9d7bcad 6604static void ssh_provide_ldisc(void *handle, void *ldisc)
6605{
6606 Ssh ssh = (Ssh) handle;
6607 ssh->ldisc = ldisc;
6608}
6609
a8327734 6610static void ssh_provide_logctx(void *handle, void *logctx)
6611{
6612 Ssh ssh = (Ssh) handle;
6613 ssh->logctx = logctx;
6614}
6615
51470298 6616static int ssh_return_exitcode(void *handle)
6617{
6618 Ssh ssh = (Ssh) handle;
3bb2f322 6619 if (ssh->s != NULL)
6620 return -1;
6621 else
6622 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 6623}
6624
6625/*
6626 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6627 * that fails. This variable is the means by which scp.c can reach
6628 * into the SSH code and find out which one it got.
6629 */
6630extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6631{
51470298 6632 Ssh ssh = (Ssh) handle;
6633 return ssh->fallback_cmd;
d8d6c7e5 6634}
6635
374330e2 6636Backend ssh_backend = {
6637 ssh_init,
fabd1805 6638 ssh_free,
86916870 6639 ssh_reconfig,
374330e2 6640 ssh_send,
5471d09a 6641 ssh_sendbuffer,
374330e2 6642 ssh_size,
4017be6d 6643 ssh_special,
125105d1 6644 ssh_get_specials,
8ccc75b0 6645 ssh_socket,
d8d6c7e5 6646 ssh_return_exitcode,
97db3be4 6647 ssh_sendok,
0965bee0 6648 ssh_ldisc,
b9d7bcad 6649 ssh_provide_ldisc,
a8327734 6650 ssh_provide_logctx,
5471d09a 6651 ssh_unthrottle,
97db3be4 6652 22
bc240b21 6653};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator