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Incorporate Brad Clarke's suggestion to use "REGEDIT /EA" rather than
[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;
5366aed8 871 zlib_decompress_block(ssh->sc_comp_ctx,
872 ssh->pktin.body - 1, ssh->pktin.length + 1,
4ba9b64b 873 &decompblk, &decomplen);
874
51470298 875 if (ssh->pktin.maxlen < st->pad + decomplen) {
876 ssh->pktin.maxlen = st->pad + decomplen;
3d88e64d 877 ssh->pktin.data = sresize(ssh->pktin.data,
878 ssh->pktin.maxlen + APIEXTRA,
879 unsigned char);
51470298 880 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 881 }
882
51470298 883 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 884 sfree(decompblk);
51470298 885 ssh->pktin.length = decomplen - 1;
4ba9b64b 886 }
887
51470298 888 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 889
a8327734 890 if (ssh->logctx)
891 log_packet(ssh->logctx,
892 PKT_INCOMING, ssh->pktin.type,
893 ssh1_pkt_type(ssh->pktin.type),
894 ssh->pktin.body, ssh->pktin.length);
00db133f 895
51470298 896 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
897 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
898 ssh->pktin.type == SSH1_MSG_DEBUG ||
899 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
900 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
901 long stringlen = GET_32BIT(ssh->pktin.body);
902 if (stringlen + 4 != ssh->pktin.length) {
6b5cf8b4 903 bombout(("Received data packet with bogus string length"));
7ffdbc1a 904 crStop(0);
32874aea 905 }
fb09bf1c 906 }
907
51470298 908 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 909 /* log debug message */
eb4504cc 910 char buf[512];
51470298 911 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 912 strcpy(buf, "Remote debug message: ");
913 if (stringlen > 480)
914 stringlen = 480;
51470298 915 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 916 buf[8 + stringlen] = '\0';
fb09bf1c 917 logevent(buf);
918 goto next_packet;
51470298 919 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 920 /* do nothing */
921 goto next_packet;
922 }
923
51470298 924 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 925 /* log reason code in disconnect message */
926 char buf[256];
51470298 927 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 928 unsigned nowlen;
38c4a8da 929 strcpy(buf, "Remote sent disconnect: ");
930 nowlen = strlen(buf);
32874aea 931 if (msglen > sizeof(buf) - nowlen - 1)
932 msglen = sizeof(buf) - nowlen - 1;
51470298 933 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 934 buf[nowlen + msglen] = '\0';
247308b5 935 /* logevent(buf); (this is now done within the bombout macro) */
6b5cf8b4 936 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
7ffdbc1a 937 crStop(0);
38c4a8da 938 }
939
fb09bf1c 940 crFinish(0);
941}
942
51470298 943static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 944{
51470298 945 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 946
51470298 947 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 948
32874aea 949 next_packet:
51470298 950 ssh->pktin.type = 0;
951 ssh->pktin.length = 0;
952 if (ssh->sccipher)
953 st->cipherblk = ssh->sccipher->blksize;
e5574168 954 else
32874aea 955 st->cipherblk = 8;
960e736a 956 if (st->cipherblk < 8)
32874aea 957 st->cipherblk = 8;
960e736a 958
51470298 959 if (ssh->pktin.maxlen < st->cipherblk) {
960 ssh->pktin.maxlen = st->cipherblk;
3d88e64d 961 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
962 unsigned char);
e5574168 963 }
964
965 /*
966 * Acquire and decrypt the first block of the packet. This will
967 * contain the length and padding details.
968 */
32874aea 969 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 970 while ((*datalen) == 0)
32874aea 971 crReturn(st->cipherblk - st->i);
51470298 972 ssh->pktin.data[st->i] = *(*data)++;
32874aea 973 (*datalen)--;
e5574168 974 }
4252c9cc 975
51470298 976 if (ssh->sccipher)
371e569c 977 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
978 ssh->pktin.data, st->cipherblk);
e5574168 979
980 /*
981 * Now get the length and padding figures.
982 */
51470298 983 st->len = GET_32BIT(ssh->pktin.data);
984 st->pad = ssh->pktin.data[4];
e5574168 985
986 /*
717dc483 987 * _Completely_ silly lengths should be stomped on before they
988 * do us any more damage.
989 */
990 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 991 bombout(("Incoming packet was garbled on decryption"));
7ffdbc1a 992 crStop(0);
717dc483 993 }
994
995 /*
e5574168 996 * This enables us to deduce the payload length.
997 */
960e736a 998 st->payload = st->len - st->pad - 1;
e5574168 999
51470298 1000 ssh->pktin.length = st->payload + 5;
e5574168 1001
1002 /*
1003 * So now we can work out the total packet length.
1004 */
960e736a 1005 st->packetlen = st->len + 4;
51470298 1006 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1007
1008 /*
1009 * Adjust memory allocation if packet is too big.
1010 */
51470298 1011 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1012 ssh->pktin.maxlen = st->packetlen + st->maclen;
3d88e64d 1013 ssh->pktin.data = sresize(ssh->pktin.data,
1014 ssh->pktin.maxlen + APIEXTRA,
1015 unsigned char);
e5574168 1016 }
1017
1018 /*
1019 * Read and decrypt the remainder of the packet.
1020 */
32874aea 1021 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1022 st->i++) {
e5574168 1023 while ((*datalen) == 0)
960e736a 1024 crReturn(st->packetlen + st->maclen - st->i);
51470298 1025 ssh->pktin.data[st->i] = *(*data)++;
32874aea 1026 (*datalen)--;
e5574168 1027 }
1028 /* Decrypt everything _except_ the MAC. */
51470298 1029 if (ssh->sccipher)
371e569c 1030 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1031 ssh->pktin.data + st->cipherblk,
51470298 1032 st->packetlen - st->cipherblk);
e5574168 1033
1034 /*
1035 * Check the MAC.
1036 */
51470298 1037 if (ssh->scmac
e0e1a00d 1038 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1039 st->incoming_sequence)) {
6b5cf8b4 1040 bombout(("Incorrect MAC received on packet"));
7ffdbc1a 1041 crStop(0);
8d5de777 1042 }
32874aea 1043 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1044
4ba9b64b 1045 /*
1046 * Decompress packet payload.
1047 */
1048 {
1049 unsigned char *newpayload;
1050 int newlen;
51470298 1051 if (ssh->sccomp &&
5366aed8 1052 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1053 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1054 &newpayload, &newlen)) {
1055 if (ssh->pktin.maxlen < newlen + 5) {
1056 ssh->pktin.maxlen = newlen + 5;
3d88e64d 1057 ssh->pktin.data = sresize(ssh->pktin.data,
1058 ssh->pktin.maxlen + APIEXTRA,
1059 unsigned char);
4ba9b64b 1060 }
51470298 1061 ssh->pktin.length = 5 + newlen;
1062 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1063 sfree(newpayload);
4ba9b64b 1064 }
1065 }
1066
51470298 1067 ssh->pktin.savedpos = 6;
1068 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1069
a8327734 1070 if (ssh->logctx)
1071 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1072 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1073 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1074
51470298 1075 switch (ssh->pktin.type) {
3d63ca2e 1076 /*
1077 * These packets we must handle instantly.
1078 */
1079 case SSH2_MSG_DISCONNECT:
1080 {
1081 /* log reason code in disconnect message */
57356d63 1082 char *buf;
1083 int nowlen;
51470298 1084 int reason = GET_32BIT(ssh->pktin.data + 6);
1085 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
57356d63 1086
3d63ca2e 1087 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
57356d63 1088 buf = dupprintf("Received disconnect message (%s)",
1089 ssh2_disconnect_reasons[reason]);
3d63ca2e 1090 } else {
57356d63 1091 buf = dupprintf("Received disconnect message (unknown"
1092 " type %d)", reason);
3d63ca2e 1093 }
1094 logevent(buf);
57356d63 1095 sfree(buf);
1096 buf = dupprintf("Disconnection message text: %n%.*s",
33b82b22 1097 &nowlen, msglen, ssh->pktin.data + 14);
3d63ca2e 1098 logevent(buf);
6b5cf8b4 1099 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1100 reason,
1101 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1102 ssh2_disconnect_reasons[reason] : "unknown",
1103 buf+nowlen));
57356d63 1104 sfree(buf);
7ffdbc1a 1105 crStop(0);
3d63ca2e 1106 }
1107 break;
1108 case SSH2_MSG_IGNORE:
1109 goto next_packet;
1110 case SSH2_MSG_DEBUG:
1111 {
1112 /* log the debug message */
1113 char buf[512];
51470298 1114 /* int display = ssh->pktin.body[6]; */
1115 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1116 int prefix;
1117 strcpy(buf, "Remote debug message: ");
1118 prefix = strlen(buf);
51470298 1119 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1120 stringlen = sizeof(buf)-prefix-1;
51470298 1121 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1122 buf[prefix + stringlen] = '\0';
1123 logevent(buf);
38c4a8da 1124 }
3d63ca2e 1125 goto next_packet; /* FIXME: print the debug message */
1126
1127 /*
1128 * These packets we need do nothing about here.
1129 */
1130 case SSH2_MSG_UNIMPLEMENTED:
1131 case SSH2_MSG_SERVICE_REQUEST:
1132 case SSH2_MSG_SERVICE_ACCEPT:
1133 case SSH2_MSG_KEXINIT:
1134 case SSH2_MSG_NEWKEYS:
1135 case SSH2_MSG_KEXDH_INIT:
1136 case SSH2_MSG_KEXDH_REPLY:
1137 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1138 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1139 case SSH2_MSG_KEX_DH_GEX_INIT:
1140 case SSH2_MSG_KEX_DH_GEX_REPLY:
1141 case SSH2_MSG_USERAUTH_REQUEST:
1142 case SSH2_MSG_USERAUTH_FAILURE:
1143 case SSH2_MSG_USERAUTH_SUCCESS:
1144 case SSH2_MSG_USERAUTH_BANNER:
1145 case SSH2_MSG_USERAUTH_PK_OK:
1146 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1147 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1148 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1149 case SSH2_MSG_GLOBAL_REQUEST:
1150 case SSH2_MSG_REQUEST_SUCCESS:
1151 case SSH2_MSG_REQUEST_FAILURE:
1152 case SSH2_MSG_CHANNEL_OPEN:
1153 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1154 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1155 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1156 case SSH2_MSG_CHANNEL_DATA:
1157 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1158 case SSH2_MSG_CHANNEL_EOF:
1159 case SSH2_MSG_CHANNEL_CLOSE:
1160 case SSH2_MSG_CHANNEL_REQUEST:
1161 case SSH2_MSG_CHANNEL_SUCCESS:
1162 case SSH2_MSG_CHANNEL_FAILURE:
1163 break;
1164
1165 /*
1166 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1167 */
1168 default:
51470298 1169 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1170 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1171 ssh2_pkt_send(ssh);
3d63ca2e 1172 break;
38c4a8da 1173 }
1174
e5574168 1175 crFinish(0);
1176}
1177
51470298 1178static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1179{
374330e2 1180 int pad, biglen;
1181
1182 len += 5; /* type and CRC */
32874aea 1183 pad = 8 - (len % 8);
374330e2 1184 biglen = len + pad;
1185
51470298 1186 ssh->pktout.length = len - 5;
1187 if (ssh->pktout.maxlen < biglen) {
1188 ssh->pktout.maxlen = biglen;
8f203108 1189#ifdef MSCRYPTOAPI
fb09bf1c 1190 /* Allocate enough buffer space for extra block
8f203108 1191 * for MS CryptEncrypt() */
3d88e64d 1192 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1193 unsigned char);
8f203108 1194#else
3d88e64d 1195 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1196 unsigned char);
8f203108 1197#endif
374330e2 1198 }
51470298 1199 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1200}
374330e2 1201
51470298 1202static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1203{
51470298 1204 ssh1_pktout_size(ssh, len);
1205 ssh->pktout.type = type;
374330e2 1206}
1207
51470298 1208static int s_wrpkt_prepare(Ssh ssh)
32874aea 1209{
fd7a4aad 1210 int pad, biglen, i;
374330e2 1211 unsigned long crc;
fd7a4aad 1212#ifdef __SC__
1213 /*
1214 * XXX various versions of SC (including 8.8.4) screw up the
1215 * register allocation in this function and use the same register
1216 * (D6) for len and as a temporary, with predictable results. The
1217 * following sledgehammer prevents this.
1218 */
1219 volatile
1220#endif
1221 int len;
374330e2 1222
51470298 1223 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1224
a8327734 1225 if (ssh->logctx)
1226 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1227 ssh1_pkt_type(ssh->pktout.type),
1228 ssh->pktout.body, ssh->pktout.length);
00db133f 1229
51470298 1230 if (ssh->v1_compressing) {
4ba9b64b 1231 unsigned char *compblk;
1232 int complen;
5366aed8 1233 zlib_compress_block(ssh->cs_comp_ctx,
1234 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1235 &compblk, &complen);
51470298 1236 ssh1_pktout_size(ssh, complen - 1);
1237 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1238 sfree(compblk);
4ba9b64b 1239 }
1240
51470298 1241 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1242 pad = 8 - (len % 8);
374330e2 1243 biglen = len + pad;
1244
32874aea 1245 for (i = 0; i < pad; i++)
51470298 1246 ssh->pktout.data[i + 4] = random_byte();
71bedafe 1247 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
51470298 1248 PUT_32BIT(ssh->pktout.data + biglen, crc);
1249 PUT_32BIT(ssh->pktout.data, len);
374330e2 1250
51470298 1251 if (ssh->cipher)
371e569c 1252 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1253
32874aea 1254 return biglen + 4;
39065bed 1255}
1256
51470298 1257static void s_wrpkt(Ssh ssh)
32874aea 1258{
5471d09a 1259 int len, backlog;
51470298 1260 len = s_wrpkt_prepare(ssh);
d8baa528 1261 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1262 if (backlog > SSH_MAX_BACKLOG)
51470298 1263 ssh_throttle_all(ssh, 1, backlog);
39065bed 1264}
1265
51470298 1266static void s_wrpkt_defer(Ssh ssh)
32874aea 1267{
39065bed 1268 int len;
51470298 1269 len = s_wrpkt_prepare(ssh);
1270 if (ssh->deferred_len + len > ssh->deferred_size) {
1271 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1272 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1273 ssh->deferred_size,
1274 unsigned char);
39065bed 1275 }
51470298 1276 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1277 ssh->deferred_len += len;
374330e2 1278}
1279
fb09bf1c 1280/*
39065bed 1281 * Construct a packet with the specified contents.
fb09bf1c 1282 */
51470298 1283static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1284{
fb09bf1c 1285 unsigned char *p, *argp, argchar;
1286 unsigned long argint;
1287 int pktlen, argtype, arglen;
7cca0d81 1288 Bignum bn;
fb09bf1c 1289
1290 pktlen = 0;
39065bed 1291 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1292 switch (argtype) {
1293 case PKT_INT:
39065bed 1294 (void) va_arg(ap1, int);
fb09bf1c 1295 pktlen += 4;
1296 break;
1297 case PKT_CHAR:
1ec39246 1298 (void) va_arg(ap1, int);
fb09bf1c 1299 pktlen++;
1300 break;
1301 case PKT_DATA:
39065bed 1302 (void) va_arg(ap1, unsigned char *);
1303 arglen = va_arg(ap1, int);
fb09bf1c 1304 pktlen += arglen;
1305 break;
1306 case PKT_STR:
39065bed 1307 argp = va_arg(ap1, unsigned char *);
d8baa528 1308 arglen = strlen((char *)argp);
fb09bf1c 1309 pktlen += 4 + arglen;
1310 break;
7cca0d81 1311 case PKT_BIGNUM:
39065bed 1312 bn = va_arg(ap1, Bignum);
32874aea 1313 pktlen += ssh1_bignum_length(bn);
7cca0d81 1314 break;
fb09bf1c 1315 default:
1316 assert(0);
1317 }
1318 }
fb09bf1c 1319
51470298 1320 s_wrpkt_start(ssh, pkttype, pktlen);
1321 p = ssh->pktout.body;
fb09bf1c 1322
39065bed 1323 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1324 switch (argtype) {
1325 case PKT_INT:
39065bed 1326 argint = va_arg(ap2, int);
fb09bf1c 1327 PUT_32BIT(p, argint);
1328 p += 4;
1329 break;
1330 case PKT_CHAR:
1ec39246 1331 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1332 *p = argchar;
1333 p++;
1334 break;
1335 case PKT_DATA:
39065bed 1336 argp = va_arg(ap2, unsigned char *);
1337 arglen = va_arg(ap2, int);
fb09bf1c 1338 memcpy(p, argp, arglen);
1339 p += arglen;
1340 break;
1341 case PKT_STR:
39065bed 1342 argp = va_arg(ap2, unsigned char *);
d8baa528 1343 arglen = strlen((char *)argp);
fb09bf1c 1344 PUT_32BIT(p, arglen);
1345 memcpy(p + 4, argp, arglen);
1346 p += 4 + arglen;
1347 break;
7cca0d81 1348 case PKT_BIGNUM:
39065bed 1349 bn = va_arg(ap2, Bignum);
32874aea 1350 p += ssh1_write_bignum(p, bn);
7cca0d81 1351 break;
fb09bf1c 1352 }
1353 }
39065bed 1354}
fb09bf1c 1355
51470298 1356static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1357{
39065bed 1358 va_list ap1, ap2;
1359 va_start(ap1, pkttype);
1360 va_start(ap2, pkttype);
51470298 1361 construct_packet(ssh, pkttype, ap1, ap2);
1362 s_wrpkt(ssh);
fb09bf1c 1363}
1364
51470298 1365static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1366{
39065bed 1367 va_list ap1, ap2;
1368 va_start(ap1, pkttype);
1369 va_start(ap2, pkttype);
51470298 1370 construct_packet(ssh, pkttype, ap1, ap2);
1371 s_wrpkt_defer(ssh);
39065bed 1372}
1373
32874aea 1374static int ssh_versioncmp(char *a, char *b)
1375{
9697bfd2 1376 char *ae, *be;
1377 unsigned long av, bv;
1378
43aa02a7 1379 av = strtoul(a, &ae, 10);
1380 bv = strtoul(b, &be, 10);
32874aea 1381 if (av != bv)
1382 return (av < bv ? -1 : +1);
1383 if (*ae == '.')
1384 ae++;
1385 if (*be == '.')
1386 be++;
43aa02a7 1387 av = strtoul(ae, &ae, 10);
1388 bv = strtoul(be, &be, 10);
32874aea 1389 if (av != bv)
1390 return (av < bv ? -1 : +1);
9697bfd2 1391 return 0;
1392}
1393
e5574168 1394/*
a92dd380 1395 * Utility routines for putting an SSH-protocol `string' and
1396 * `uint32' into a SHA state.
e5574168 1397 */
1398#include <stdio.h>
32874aea 1399static void sha_string(SHA_State * s, void *str, int len)
1400{
e5574168 1401 unsigned char lenblk[4];
e5574168 1402 PUT_32BIT(lenblk, len);
e5574168 1403 SHA_Bytes(s, lenblk, 4);
e5574168 1404 SHA_Bytes(s, str, len);
1405}
1406
32874aea 1407static void sha_uint32(SHA_State * s, unsigned i)
1408{
a92dd380 1409 unsigned char intblk[4];
1410 PUT_32BIT(intblk, i);
1411 SHA_Bytes(s, intblk, 4);
1412}
1413
7cca0d81 1414/*
1415 * SSH2 packet construction functions.
1416 */
51470298 1417static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1418{
51470298 1419 if (ssh->pktout.maxlen < length) {
1420 ssh->pktout.maxlen = length + 256;
3d88e64d 1421 ssh->pktout.data = sresize(ssh->pktout.data,
1422 ssh->pktout.maxlen + APIEXTRA,
1423 unsigned char);
51470298 1424 if (!ssh->pktout.data)
32874aea 1425 fatalbox("Out of memory");
7cca0d81 1426 }
783415f8 1427}
51470298 1428static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1429{
51470298 1430 ssh->pktout.length += len;
1431 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1432 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1433}
51470298 1434static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1435{
51470298 1436 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1437}
51470298 1438static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1439{
51470298 1440 ssh->pktout.length = 5;
1441 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1442}
51470298 1443static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1444{
51470298 1445 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1446}
51470298 1447static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1448{
7cca0d81 1449 unsigned char x[4];
1450 PUT_32BIT(x, value);
51470298 1451 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1452}
51470298 1453static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1454{
51470298 1455 ssh2_pkt_adduint32(ssh, 0);
1456 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1457}
51470298 1458static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1459{
51470298 1460 ssh2_pkt_adddata(ssh, data, strlen(data));
1461 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1462 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1463}
51470298 1464static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1465{
51470298 1466 ssh2_pkt_adddata(ssh, data, len);
1467 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1468 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1469}
51470298 1470static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1471{
51470298 1472 ssh2_pkt_addstring_start(ssh);
1473 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1474}
d8baa528 1475static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1476{
7cca0d81 1477 unsigned char *p;
32874aea 1478 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1479 p = snewn(n + 1, unsigned char);
7cca0d81 1480 if (!p)
32874aea 1481 fatalbox("out of memory");
7cca0d81 1482 p[0] = 0;
3709bfe9 1483 for (i = 1; i <= n; i++)
32874aea 1484 p[i] = bignum_byte(b, n - i);
7cca0d81 1485 i = 0;
32874aea 1486 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1487 i++;
1488 memmove(p, p + i, n + 1 - i);
1489 *len = n + 1 - i;
7cca0d81 1490 return p;
1491}
51470298 1492static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1493{
7cca0d81 1494 unsigned char *p;
1495 int len;
1496 p = ssh2_mpint_fmt(b, &len);
51470298 1497 ssh2_pkt_addstring_start(ssh);
d8baa528 1498 ssh2_pkt_addstring_data(ssh, (char *)p, len);
dcbde236 1499 sfree(p);
7cca0d81 1500}
b185170a 1501
1502/*
1503 * Construct an SSH2 final-form packet: compress it, encrypt it,
1504 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1505 * ssh->pktout.data. Total length is returned.
b185170a 1506 */
51470298 1507static int ssh2_pkt_construct(Ssh ssh)
32874aea 1508{
7cca0d81 1509 int cipherblk, maclen, padding, i;
7cca0d81 1510
a8327734 1511 if (ssh->logctx)
1512 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1513 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1514 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1515
7cca0d81 1516 /*
4ba9b64b 1517 * Compress packet payload.
1518 */
4ba9b64b 1519 {
1520 unsigned char *newpayload;
1521 int newlen;
51470298 1522 if (ssh->cscomp &&
5366aed8 1523 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1524 ssh->pktout.length - 5,
51470298 1525 &newpayload, &newlen)) {
1526 ssh->pktout.length = 5;
1527 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1528 sfree(newpayload);
4ba9b64b 1529 }
1530 }
1531
1532 /*
7cca0d81 1533 * Add padding. At least four bytes, and must also bring total
1534 * length (minus MAC) up to a multiple of the block size.
1535 */
51470298 1536 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1537 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1538 padding = 4;
32874aea 1539 padding +=
51470298 1540 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1541 maclen = ssh->csmac ? ssh->csmac->len : 0;
1542 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1543 ssh->pktout.data[4] = padding;
7cca0d81 1544 for (i = 0; i < padding; i++)
51470298 1545 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1546 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1547 if (ssh->csmac)
e0e1a00d 1548 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1549 ssh->pktout.length + padding,
51470298 1550 ssh->v2_outgoing_sequence);
1551 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1552
1553 if (ssh->cscipher)
371e569c 1554 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1555 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1556
1557 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1558 return ssh->pktout.length + padding + maclen;
b185170a 1559}
1560
1561/*
1562 * Construct and send an SSH2 packet immediately.
1563 */
51470298 1564static void ssh2_pkt_send(Ssh ssh)
32874aea 1565{
5471d09a 1566 int len;
1567 int backlog;
51470298 1568 len = ssh2_pkt_construct(ssh);
d8baa528 1569 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1570 if (backlog > SSH_MAX_BACKLOG)
51470298 1571 ssh_throttle_all(ssh, 1, backlog);
b185170a 1572}
1573
1574/*
1575 * Construct an SSH2 packet and add it to a deferred data block.
1576 * Useful for sending multiple packets in a single sk_write() call,
1577 * to prevent a traffic-analysing listener from being able to work
1578 * out the length of any particular packet (such as the password
1579 * packet).
1580 *
1581 * Note that because SSH2 sequence-numbers its packets, this can
1582 * NOT be used as an m4-style `defer' allowing packets to be
1583 * constructed in one order and sent in another.
1584 */
51470298 1585static void ssh2_pkt_defer(Ssh ssh)
32874aea 1586{
51470298 1587 int len = ssh2_pkt_construct(ssh);
1588 if (ssh->deferred_len + len > ssh->deferred_size) {
1589 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1590 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1591 ssh->deferred_size,
1592 unsigned char);
b185170a 1593 }
51470298 1594 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1595 ssh->deferred_len += len;
b185170a 1596}
1597
1598/*
1599 * Send the whole deferred data block constructed by
39065bed 1600 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1601 */
51470298 1602static void ssh_pkt_defersend(Ssh ssh)
32874aea 1603{
5471d09a 1604 int backlog;
d8baa528 1605 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1606 ssh->deferred_len);
51470298 1607 ssh->deferred_len = ssh->deferred_size = 0;
1608 sfree(ssh->deferred_send_data);
1609 ssh->deferred_send_data = NULL;
5471d09a 1610 if (backlog > SSH_MAX_BACKLOG)
51470298 1611 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1612}
1613
1614#if 0
32874aea 1615void bndebug(char *string, Bignum b)
1616{
7cca0d81 1617 unsigned char *p;
1618 int i, len;
1619 p = ssh2_mpint_fmt(b, &len);
1620 debug(("%s", string));
1621 for (i = 0; i < len; i++)
32874aea 1622 debug((" %02x", p[i]));
765c4200 1623 debug(("\n"));
dcbde236 1624 sfree(p);
7cca0d81 1625}
1626#endif
1627
32874aea 1628static void sha_mpint(SHA_State * s, Bignum b)
1629{
7cca0d81 1630 unsigned char *p;
1631 int len;
1632 p = ssh2_mpint_fmt(b, &len);
1633 sha_string(s, p, len);
dcbde236 1634 sfree(p);
7cca0d81 1635}
1636
1637/*
1638 * SSH2 packet decode functions.
1639 */
51470298 1640static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1641{
7cca0d81 1642 unsigned long value;
51470298 1643 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1644 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1645 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1646 ssh->pktin.savedpos += 4;
7cca0d81 1647 return value;
1648}
51470298 1649static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1650{
65a22376 1651 unsigned long value;
51470298 1652 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1653 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1654 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1655 ssh->pktin.savedpos++;
65a22376 1656 return value;
1657}
51470298 1658static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1659{
57356d63 1660 int len;
7cca0d81 1661 *p = NULL;
45068b27 1662 *length = 0;
51470298 1663 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1664 return;
57356d63 1665 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1666 if (len < 0)
1667 return;
1668 *length = len;
51470298 1669 ssh->pktin.savedpos += 4;
1670 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1671 return;
d8baa528 1672 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
51470298 1673 ssh->pktin.savedpos += *length;
7cca0d81 1674}
51470298 1675static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1676{
7cca0d81 1677 char *p;
3709bfe9 1678 int length;
7cca0d81 1679 Bignum b;
1680
51470298 1681 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1682 if (!p)
32874aea 1683 return NULL;
8d5de777 1684 if (p[0] & 0x80) {
6b5cf8b4 1685 bombout(("internal error: Can't handle negative mpints"));
32874aea 1686 return NULL;
8d5de777 1687 }
d8baa528 1688 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1689 return b;
1690}
1691
7d503c31 1692/*
1dd353b5 1693 * Helper function to add an SSH2 signature blob to a packet.
1694 * Expects to be shown the public key blob as well as the signature
1695 * blob. Normally works just like ssh2_pkt_addstring, but will
1696 * fiddle with the signature packet if necessary for
1697 * BUG_SSH2_RSA_PADDING.
1698 */
51470298 1699static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1700 void *sigblob_v, int sigblob_len)
1701{
1702 unsigned char *pkblob = (unsigned char *)pkblob_v;
1703 unsigned char *sigblob = (unsigned char *)sigblob_v;
1704
1705 /* dmemdump(pkblob, pkblob_len); */
1706 /* dmemdump(sigblob, sigblob_len); */
1707
1708 /*
1709 * See if this is in fact an ssh-rsa signature and a buggy
1710 * server; otherwise we can just do this the easy way.
1711 */
51470298 1712 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1713 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1714 int pos, len, siglen;
1715
1716 /*
1717 * Find the byte length of the modulus.
1718 */
1719
1720 pos = 4+7; /* skip over "ssh-rsa" */
1721 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1722 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1723 pos += 4; /* find modulus itself */
1724 while (len > 0 && pkblob[pos] == 0)
1725 len--, pos++;
1726 /* debug(("modulus length is %d\n", len)); */
1727
1728 /*
1729 * Now find the signature integer.
1730 */
1731 pos = 4+7; /* skip over "ssh-rsa" */
1732 siglen = GET_32BIT(sigblob+pos);
1733 /* debug(("signature length is %d\n", siglen)); */
1734
1735 if (len != siglen) {
1736 unsigned char newlen[4];
51470298 1737 ssh2_pkt_addstring_start(ssh);
d8baa528 1738 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1dd353b5 1739 /* dmemdump(sigblob, pos); */
1740 pos += 4; /* point to start of actual sig */
1741 PUT_32BIT(newlen, len);
d8baa528 1742 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1dd353b5 1743 /* dmemdump(newlen, 4); */
1744 newlen[0] = 0;
1745 while (len-- > siglen) {
d8baa528 1746 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1dd353b5 1747 /* dmemdump(newlen, 1); */
1748 }
d8baa528 1749 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1dd353b5 1750 /* dmemdump(sigblob+pos, siglen); */
1751 return;
1752 }
1753
1754 /* Otherwise fall through and do it the easy way. */
1755 }
1756
51470298 1757 ssh2_pkt_addstring_start(ssh);
d8baa528 1758 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1dd353b5 1759}
1760
1761/*
7d503c31 1762 * Examine the remote side's version string and compare it against
1763 * a list of known buggy implementations.
1764 */
51470298 1765static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1766{
1767 char *imp; /* pointer to implementation part */
7d503c31 1768 imp = vstring;
1769 imp += strcspn(imp, "-");
bd358db1 1770 if (*imp) imp++;
7d503c31 1771 imp += strcspn(imp, "-");
bd358db1 1772 if (*imp) imp++;
7d503c31 1773
51470298 1774 ssh->remote_bugs = 0;
7d503c31 1775
5ecd7ad0 1776 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1777 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1778 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1779 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1780 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1781 /*
1782 * These versions don't support SSH1_MSG_IGNORE, so we have
1783 * to use a different defence against password length
1784 * sniffing.
1785 */
51470298 1786 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1787 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1788 }
1789
5ecd7ad0 1790 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1791 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2c9c6388 1792 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1793 /*
1794 * These versions need a plain password sent; they can't
1795 * handle having a null and a random length of data after
1796 * the password.
1797 */
51470298 1798 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1799 logevent("We believe remote version needs a plain SSH1 password");
1800 }
1801
5ecd7ad0 1802 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1803 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 1804 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1805 /*
1806 * These versions apparently have no clue whatever about
1807 * RSA authentication and will panic and die if they see
1808 * an AUTH_RSA message.
1809 */
51470298 1810 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1811 logevent("We believe remote version can't handle RSA authentication");
1812 }
1813
5ecd7ad0 1814 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1815 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 1816 !wc_match("* VShell", imp) &&
831301f6 1817 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1818 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1819 wc_match("2.1 *", imp)))) {
32874aea 1820 /*
1821 * These versions have the HMAC bug.
1822 */
51470298 1823 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1824 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1825 }
1dd353b5 1826
5ecd7ad0 1827 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1828 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 1829 !wc_match("* VShell", imp) &&
2856a1b9 1830 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 1831 /*
1832 * These versions have the key-derivation bug (failing to
1833 * include the literal shared secret in the hashes that
1834 * generate the keys).
1835 */
51470298 1836 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1837 logevent("We believe remote version has SSH2 key-derivation bug");
1838 }
1839
5ecd7ad0 1840 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1841 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 1842 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1843 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 1844 /*
1845 * These versions have the SSH2 RSA padding bug.
1846 */
51470298 1847 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1848 logevent("We believe remote version has SSH2 RSA padding bug");
1849 }
8e975795 1850
dda87a28 1851 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1852 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1853 wc_match("OpenSSH_2.[0-2]*", imp))) {
1854 /*
1855 * These versions have the SSH2 session-ID bug in
1856 * public-key authentication.
1857 */
1858 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1859 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1860 }
1861
5ecd7ad0 1862 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 1863 /*
831301f6 1864 * User specified the SSH2 DH GEX bug.
8e975795 1865 */
51470298 1866 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1867 logevent("We believe remote version has SSH2 DH group exchange bug");
1868 }
7d503c31 1869}
1870
51470298 1871static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1872{
51470298 1873 struct do_ssh_init_state {
1874 int vslen;
1875 char version[10];
1876 char *vstring;
1877 int vstrsize;
1878 int i;
1879 int proto1, proto2;
1880 };
1881 crState(do_ssh_init_state);
374330e2 1882
51470298 1883 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1884
1885 /* Search for the string "SSH-" in the input. */
51470298 1886 s->i = 0;
8df7a775 1887 while (1) {
1888 static const int transS[] = { 1, 2, 2, 1 };
1889 static const int transH[] = { 0, 0, 3, 0 };
1890 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1891 if (c == 'S')
51470298 1892 s->i = transS[s->i];
32874aea 1893 else if (c == 'H')
51470298 1894 s->i = transH[s->i];
32874aea 1895 else if (c == '-')
51470298 1896 s->i = transminus[s->i];
32874aea 1897 else
51470298 1898 s->i = 0;
1899 if (s->i < 0)
8df7a775 1900 break;
1901 crReturn(1); /* get another character */
374330e2 1902 }
8df7a775 1903
51470298 1904 s->vstrsize = 16;
3d88e64d 1905 s->vstring = snewn(s->vstrsize, char);
51470298 1906 strcpy(s->vstring, "SSH-");
1907 s->vslen = 4;
1908 s->i = 0;
374330e2 1909 while (1) {
8df7a775 1910 crReturn(1); /* get another char */
51470298 1911 if (s->vslen >= s->vstrsize - 1) {
1912 s->vstrsize += 16;
3d88e64d 1913 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 1914 }
51470298 1915 s->vstring[s->vslen++] = c;
1916 if (s->i >= 0) {
374330e2 1917 if (c == '-') {
51470298 1918 s->version[s->i] = '\0';
1919 s->i = -1;
1920 } else if (s->i < sizeof(s->version) - 1)
1921 s->version[s->i++] = c;
c4ffc4d0 1922 } else if (c == '\012')
374330e2 1923 break;
1924 }
1925
51470298 1926 ssh->agentfwd_enabled = FALSE;
1927 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1928
51470298 1929 s->vstring[s->vslen] = 0;
1930 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1931 {
1932 char *vlog;
3d88e64d 1933 vlog = snewn(20 + s->vslen, char);
51470298 1934 sprintf(vlog, "Server version: %s", s->vstring);
1935 logevent(vlog);
1936 sfree(vlog);
1937 }
1938 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1939
adf799dd 1940 /*
38d228a2 1941 * Decide which SSH protocol version to support.
adf799dd 1942 */
38d228a2 1943
1944 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1945 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1946 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1947 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1948
86916870 1949 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 1950 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 1951 crStop(0);
38d228a2 1952 }
86916870 1953 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 1954 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 1955 crStop(0);
38d228a2 1956 }
1957
86916870 1958 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1959 /*
38d228a2 1960 * Use v2 protocol.
32874aea 1961 */
1962 char verstring[80], vlog[100];
1963 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1964 SHA_Init(&ssh->exhashbase);
32874aea 1965 /*
1966 * Hash our version string and their version string.
1967 */
51470298 1968 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1969 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1970 sprintf(vlog, "We claim version: %s", verstring);
1971 logevent(vlog);
c4ffc4d0 1972 strcat(verstring, "\012");
32874aea 1973 logevent("Using SSH protocol version 2");
51470298 1974 sk_write(ssh->s, verstring, strlen(verstring));
1975 ssh->protocol = ssh2_protocol;
1976 ssh->version = 2;
1977 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1978 } else {
32874aea 1979 /*
38d228a2 1980 * Use v1 protocol.
32874aea 1981 */
1982 char verstring[80], vlog[100];
1983 sprintf(verstring, "SSH-%s-%s",
51470298 1984 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1985 sshver);
1986 sprintf(vlog, "We claim version: %s", verstring);
1987 logevent(vlog);
c4ffc4d0 1988 strcat(verstring, "\012");
759712a6 1989
32874aea 1990 logevent("Using SSH protocol version 1");
51470298 1991 sk_write(ssh->s, verstring, strlen(verstring));
1992 ssh->protocol = ssh1_protocol;
1993 ssh->version = 1;
1994 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1995 }
125105d1 1996 update_specials_menu(ssh->frontend);
51470298 1997 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1998
51470298 1999 sfree(s->vstring);
50526e47 2000
8df7a775 2001 crFinish(0);
2002}
2003
51470298 2004static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2005{
51470298 2006 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2007
2008 /*
2009 * To begin with, feed the characters one by one to the
2010 * protocol initialisation / selection function do_ssh_init().
2011 * When that returns 0, we're done with the initial greeting
2012 * exchange and can move on to packet discipline.
2013 */
2014 while (1) {
51470298 2015 int ret; /* need not be kept across crReturn */
8df7a775 2016 if (datalen == 0)
2017 crReturnV; /* more data please */
51470298 2018 ret = do_ssh_init(ssh, *data);
32874aea 2019 data++;
2020 datalen--;
8df7a775 2021 if (ret == 0)
2022 break;
2023 }
2024
2025 /*
2026 * We emerge from that loop when the initial negotiation is
2027 * over and we have selected an s_rdpkt function. Now pass
2028 * everything to s_rdpkt, and then pass the resulting packets
2029 * to the proper protocol handler.
2030 */
2031 if (datalen == 0)
2032 crReturnV;
2033 while (1) {
2034 while (datalen > 0) {
51470298 2035 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2036 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 2037 return;
2038 }
51470298 2039 ssh->protocol(ssh, NULL, 0, 1);
2040 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 2041 return;
2042 }
2043 }
2044 }
2045 crReturnV;
2046 }
2047 crFinishV;
2048}
2049
36f94d1f 2050static void ssh_do_close(Ssh ssh)
32874aea 2051{
36f94d1f 2052 int i;
2053 struct ssh_channel *c;
2054
51470298 2055 ssh->state = SSH_STATE_CLOSED;
2056 if (ssh->s) {
2057 sk_close(ssh->s);
2058 ssh->s = NULL;
f3ab576e 2059 }
36f94d1f 2060 /*
2061 * Now we must shut down any port and X forwardings going
2062 * through this connection.
2063 */
74a98066 2064 if (ssh->channels) {
2065 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2066 switch (c->type) {
2067 case CHAN_X11:
2068 x11_close(c->u.x11.s);
2069 break;
2070 case CHAN_SOCKDATA:
2071 pfd_close(c->u.pfd.s);
2072 break;
2073 }
2074 del234(ssh->channels, c);
2075 if (ssh->version == 2)
2076 bufchain_clear(&c->v.v2.outbuffer);
2077 sfree(c);
36f94d1f 2078 }
36f94d1f 2079 }
2080}
2081
cbe2d68f 2082static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2083 int calling_back)
2084{
2085 Ssh ssh = (Ssh) plug;
2086 ssh_do_close(ssh);
7e78000d 2087 if (error_msg) {
32874aea 2088 /* A socket error has occurred. */
247308b5 2089 logevent(error_msg);
971bcc0a 2090 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2091 } else {
2092 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2093 }
7e78000d 2094 return 0;
2095}
2096
32874aea 2097static int ssh_receive(Plug plug, int urgent, char *data, int len)
2098{
51470298 2099 Ssh ssh = (Ssh) plug;
d8baa528 2100 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2101 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2102 ssh_do_close(ssh);
32874aea 2103 return 0;
3257deae 2104 }
fef97f43 2105 return 1;
374330e2 2106}
2107
5471d09a 2108static void ssh_sent(Plug plug, int bufsize)
2109{
51470298 2110 Ssh ssh = (Ssh) plug;
5471d09a 2111 /*
2112 * If the send backlog on the SSH socket itself clears, we
2113 * should unthrottle the whole world if it was throttled.
2114 */
2115 if (bufsize < SSH_MAX_BACKLOG)
51470298 2116 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2117}
2118
fb09bf1c 2119/*
8df7a775 2120 * Connect to specified host and port.
2121 * Returns an error message, or NULL on success.
6e1ebb76 2122 * Also places the canonical host name into `realhost'. It must be
2123 * freed by the caller.
8df7a775 2124 */
cbe2d68f 2125static const char *connect_to_host(Ssh ssh, char *host, int port,
2126 char **realhost, int nodelay)
8df7a775 2127{
51470298 2128 static const struct plug_function_table fn_table = {
7e78000d 2129 ssh_closing,
5471d09a 2130 ssh_receive,
2131 ssh_sent,
2132 NULL
51470298 2133 };
7e78000d 2134
8df7a775 2135 SockAddr addr;
cbe2d68f 2136 const char *err;
8df7a775 2137
3d88e64d 2138 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2139 if (!ssh->savedhost)
8df7a775 2140 fatalbox("Out of memory");
51470298 2141 strcpy(ssh->savedhost, host);
8df7a775 2142
2143 if (port < 0)
2144 port = 22; /* default ssh port */
51470298 2145 ssh->savedport = port;
8df7a775 2146
2147 /*
2148 * Try to find host.
2149 */
57356d63 2150 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2151 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2152 if ((err = sk_addr_error(addr)) != NULL) {
2153 sk_addr_free(addr);
8df7a775 2154 return err;
170c1e6e 2155 }
8df7a775 2156
8df7a775 2157 /*
2158 * Open socket.
2159 */
3ad9d396 2160 {
57356d63 2161 char addrbuf[100];
3ad9d396 2162 sk_getaddr(addr, addrbuf, 100);
57356d63 2163 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2164 }
51470298 2165 ssh->fn = &fn_table;
e8fa8f62 2166 ssh->s = new_connection(addr, *realhost, port,
2167 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
170c1e6e 2168 sk_addr_free(addr);
70e5d0fd 2169 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2170 ssh->s = NULL;
8df7a775 2171 return err;
67c4ba2e 2172 }
8df7a775 2173
8df7a775 2174 return NULL;
2175}
2176
2177/*
5471d09a 2178 * Throttle or unthrottle the SSH connection.
2179 */
51470298 2180static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2181{
51470298 2182 int old_count = ssh->v1_throttle_count;
2183 ssh->v1_throttle_count += adjust;
2184 assert(ssh->v1_throttle_count >= 0);
2185 if (ssh->v1_throttle_count && !old_count) {
2186 sk_set_frozen(ssh->s, 1);
2187 } else if (!ssh->v1_throttle_count && old_count) {
2188 sk_set_frozen(ssh->s, 0);
5471d09a 2189 }
2190}
2191
2192/*
2193 * Throttle or unthrottle _all_ local data streams (for when sends
2194 * on the SSH connection itself back up).
2195 */
51470298 2196static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2197{
2198 int i;
2199 struct ssh_channel *c;
2200
51470298 2201 if (enable == ssh->throttled_all)
5471d09a 2202 return;
51470298 2203 ssh->throttled_all = enable;
2204 ssh->overall_bufsize = bufsize;
2205 if (!ssh->channels)
5471d09a 2206 return;
51470298 2207 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2208 switch (c->type) {
2209 case CHAN_MAINSESSION:
2210 /*
2211 * This is treated separately, outside the switch.
2212 */
2213 break;
2214 case CHAN_X11:
2215 x11_override_throttle(c->u.x11.s, enable);
2216 break;
2217 case CHAN_AGENT:
2218 /* Agent channels require no buffer management. */
2219 break;
2220 case CHAN_SOCKDATA:
36f94d1f 2221 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2222 break;
2223 }
2224 }
2225}
2226
2227/*
51470298 2228 * Username and password input, abstracted off into routines
2229 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2230 */
0405e71f 2231
2232/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2233static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2234{
51470298 2235 ssh->userpass_input_buffer = buffer;
2236 ssh->userpass_input_buflen = buflen;
2237 ssh->userpass_input_bufpos = 0;
2238 ssh->userpass_input_echo = echo;
0405e71f 2239}
2240
2241/*
2242 * Process some terminal data in the course of username/password
2243 * input. Returns >0 for success (line of input returned in
2244 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2245 * for inconclusive (keep waiting for more input please).
2246 */
ae9ae89f 2247static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2248{
2249 char c;
2250
2251 while (inlen--) {
2252 switch (c = *in++) {
2253 case 10:
2254 case 13:
51470298 2255 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2256 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2257 return +1;
2258 break;
2259 case 8:
2260 case 127:
51470298 2261 if (ssh->userpass_input_bufpos > 0) {
2262 if (ssh->userpass_input_echo)
2263 c_write_str(ssh, "\b \b");
2264 ssh->userpass_input_bufpos--;
0405e71f 2265 }
2266 break;
2267 case 21:
2268 case 27:
51470298 2269 while (ssh->userpass_input_bufpos > 0) {
2270 if (ssh->userpass_input_echo)
2271 c_write_str(ssh, "\b \b");
2272 ssh->userpass_input_bufpos--;
0405e71f 2273 }
2274 break;
2275 case 3:
2276 case 4:
2277 return -1;
2278 break;
2279 default:
4692a14a 2280 /*
2281 * This simplistic check for printability is disabled
2282 * when we're doing password input, because some people
2283 * have control characters in their passwords.o
2284 */
2285 if ((!ssh->userpass_input_echo ||
2286 (c >= ' ' && c <= '~') ||
0405e71f 2287 ((unsigned char) c >= 160))
51470298 2288 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2289 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2290 if (ssh->userpass_input_echo)
2291 c_write(ssh, &c, 1);
0405e71f 2292 }
2293 break;
2294 }
2295 }
2296 return 0;
2297}
2298
f11d78f2 2299static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2300{
2301 Ssh ssh = (Ssh) sshv;
2302
2303 ssh->agent_response = reply;
2304 ssh->agent_response_len = replylen;
2305
2306 if (ssh->version == 1)
2307 do_ssh1_login(ssh, NULL, -1, 0);
2308 else
2309 do_ssh2_authconn(ssh, NULL, -1, 0);
2310}
2311
f11d78f2 2312static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2313{
2314 struct ssh_channel *c = (struct ssh_channel *)cv;
2315 Ssh ssh = c->ssh;
2316 void *sentreply = reply;
2317
2318 if (!sentreply) {
2319 /* Fake SSH_AGENT_FAILURE. */
2320 sentreply = "\0\0\0\1\5";
2321 replylen = 5;
2322 }
2323 if (ssh->version == 2) {
2324 ssh2_add_channel_data(c, sentreply, replylen);
2325 ssh2_try_send(c);
2326 } else {
2327 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2328 PKT_INT, c->remoteid,
2329 PKT_INT, replylen,
2330 PKT_DATA, sentreply, replylen,
2331 PKT_END);
2332 }
2333 if (reply)
2334 sfree(reply);
2335}
2336
0405e71f 2337/*
fb09bf1c 2338 * Handle the key exchange and user authentication phases.
2339 */
51470298 2340static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2341{
2d466ffd 2342 int i, j;
374330e2 2343 unsigned char cookie[8];
2344 struct RSAKey servkey, hostkey;
2345 struct MD5Context md5c;
51470298 2346 struct do_ssh1_login_state {
2347 int len;
2348 unsigned char *rsabuf, *keystr1, *keystr2;
2349 unsigned long supported_ciphers_mask, supported_auths_mask;
2350 int tried_publickey, tried_agent;
2351 int tis_auth_refused, ccard_auth_refused;
2352 unsigned char session_id[16];
2353 int cipher_type;
2354 char username[100];
2355 void *publickey_blob;
2356 int publickey_bloblen;
2357 char password[100];
2358 char prompt[200];
2359 int pos;
2360 char c;
2361 int pwpkt_type;
2362 unsigned char request[5], *response, *p;
2363 int responselen;
2364 int keyi, nkeys;
2365 int authed;
2366 struct RSAKey key;
2367 Bignum challenge;
2368 char *commentp;
2369 int commentlen;
2370 };
2371 crState(do_ssh1_login_state);
2372
2373 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2374
32874aea 2375 if (!ispkt)
2376 crWaitUntil(ispkt);
374330e2 2377
51470298 2378 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2379 bombout(("Public key packet not received"));
7ffdbc1a 2380 crStop(0);
8d5de777 2381 }
374330e2 2382
c5e9c988 2383 logevent("Received public keys");
374330e2 2384
51470298 2385 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2386
51470298 2387 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2388 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2389
c5e9c988 2390 /*
1c2a93c4 2391 * Log the host key fingerprint.
c5e9c988 2392 */
c5e9c988 2393 {
2394 char logmsg[80];
1c2a93c4 2395 logevent("Host key fingerprint is:");
c5e9c988 2396 strcpy(logmsg, " ");
32874aea 2397 hostkey.comment = NULL;
2398 rsa_fingerprint(logmsg + strlen(logmsg),
2399 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2400 logevent(logmsg);
2401 }
2402
51470298 2403 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2404 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2405 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2406
51470298 2407 ssh->v1_local_protoflags =
2408 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2409 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2410
c5e9c988 2411 MD5Init(&md5c);
51470298 2412 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2413 MD5Update(&md5c, s->keystr1, servkey.bytes);
2414 MD5Update(&md5c, ssh->pktin.body, 8);
2415 MD5Final(s->session_id, &md5c);
374330e2 2416
32874aea 2417 for (i = 0; i < 32; i++)
51470298 2418 ssh->session_key[i] = random_byte();
374330e2 2419
51470298 2420 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2421
3d88e64d 2422 s->rsabuf = snewn(s->len, unsigned char);
51470298 2423 if (!s->rsabuf)
374330e2 2424 fatalbox("Out of memory");
2425
89ee5268 2426 /*
2427 * Verify the host key.
2428 */
2429 {
32874aea 2430 /*
2431 * First format the key into a string.
2432 */
2433 int len = rsastr_len(&hostkey);
2434 char fingerprint[100];
3d88e64d 2435 char *keystr = snewn(len, char);
32874aea 2436 if (!keystr)
2437 fatalbox("Out of memory");
2438 rsastr_fmt(keystr, &hostkey);
2439 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2440 verify_ssh_host_key(ssh->frontend,
2441 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2442 fingerprint);
2443 sfree(keystr);
2444 }
2445
2446 for (i = 0; i < 32; i++) {
51470298 2447 s->rsabuf[i] = ssh->session_key[i];
374330e2 2448 if (i < 16)
51470298 2449 s->rsabuf[i] ^= s->session_id[i];
374330e2 2450 }
2451
2452 if (hostkey.bytes > servkey.bytes) {
51470298 2453 rsaencrypt(s->rsabuf, 32, &servkey);
2454 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2455 } else {
51470298 2456 rsaencrypt(s->rsabuf, 32, &hostkey);
2457 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2458 }
2459
c5e9c988 2460 logevent("Encrypted session key");
2461
ca20bfcf 2462 {
2463 int cipher_chosen = 0, warn = 0;
2464 char *cipher_string = NULL;
51470298 2465 int i;
ca20bfcf 2466 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2467 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2468 if (next_cipher == CIPHER_WARN) {
2469 /* If/when we choose a cipher, warn about it */
2470 warn = 1;
2471 } else if (next_cipher == CIPHER_AES) {
2472 /* XXX Probably don't need to mention this. */
2473 logevent("AES not supported in SSH1, skipping");
2474 } else {
2475 switch (next_cipher) {
51470298 2476 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2477 cipher_string = "3DES"; break;
51470298 2478 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2479 cipher_string = "Blowfish"; break;
51470298 2480 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2481 cipher_string = "single-DES"; break;
2482 }
51470298 2483 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2484 cipher_chosen = 1;
2485 }
2486 }
2487 if (!cipher_chosen) {
51470298 2488 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2489 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2490 "supporting 3DES encryption"));
2491 else
2492 /* shouldn't happen */
6b5cf8b4 2493 bombout(("No supported ciphers found"));
7ffdbc1a 2494 crStop(0);
a99a05c0 2495 }
ca20bfcf 2496
2497 /* Warn about chosen cipher if necessary. */
2498 if (warn)
a8327734 2499 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2500 }
ca20bfcf 2501
51470298 2502 switch (s->cipher_type) {
32874aea 2503 case SSH_CIPHER_3DES:
2504 logevent("Using 3DES encryption");
2505 break;
2506 case SSH_CIPHER_DES:
2507 logevent("Using single-DES encryption");
2508 break;
2509 case SSH_CIPHER_BLOWFISH:
2510 logevent("Using Blowfish encryption");
2511 break;
c5e9c988 2512 }
bea1ef5f 2513
51470298 2514 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2515 PKT_CHAR, s->cipher_type,
32874aea 2516 PKT_DATA, cookie, 8,
51470298 2517 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2518 PKT_DATA, s->rsabuf, s->len,
2519 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2520
c5e9c988 2521 logevent("Trying to enable encryption...");
374330e2 2522
51470298 2523 sfree(s->rsabuf);
374330e2 2524
51470298 2525 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2526 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2527 &ssh_3des);
371e569c 2528 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2529 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2530 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2531
0183b242 2532 ssh->crcda_ctx = crcda_make_context();
2533 logevent("Installing CRC compensation attack detector");
2534
fb09bf1c 2535 crWaitUntil(ispkt);
374330e2 2536
51470298 2537 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2538 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2539 crStop(0);
8d5de777 2540 }
374330e2 2541
c5e9c988 2542 logevent("Successfully started encryption");
2543
374330e2 2544 fflush(stdout);
2545 {
86916870 2546 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 2547 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2548 if (!ssh_get_line("login as: ",
51470298 2549 s->username, sizeof(s->username), FALSE)) {
32874aea 2550 /*
2551 * get_line failed to get a username.
2552 * Terminate.
2553 */
2554 logevent("No username provided. Abandoning session.");
3bb2f322 2555 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2556 crStop(1);
32874aea 2557 }
2558 } else {
51470298 2559 int ret; /* need not be kept over crReturn */
2560 c_write_str(ssh, "login as: ");
2561 ssh->send_ok = 1;
0405e71f 2562
51470298 2563 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2564 do {
32874aea 2565 crWaitUntil(!ispkt);
51470298 2566 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2567 } while (ret == 0);
2568 if (ret < 0)
2569 cleanup_exit(0);
51470298 2570 c_write_str(ssh, "\r\n");
32874aea 2571 }
2572 } else {
86916870 2573 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2574 s->username[sizeof(s->username)-1] = '\0';
374330e2 2575 }
fb09bf1c 2576
51470298 2577 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2578 {
51470298 2579 char userlog[22 + sizeof(s->username)];
2580 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2581 logevent(userlog);
32874aea 2582 if (flags & FLAG_INTERACTIVE &&
2583 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2584 strcat(userlog, "\r\n");
51470298 2585 c_write_str(ssh, userlog);
3c8e959b 2586 }
c5e9c988 2587 }
374330e2 2588 }
2589
fb09bf1c 2590 crWaitUntil(ispkt);
374330e2 2591
51470298 2592 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2593 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2594 s->tried_publickey = s->tried_agent = 1;
0df73905 2595 } else {
51470298 2596 s->tried_publickey = s->tried_agent = 0;
0df73905 2597 }
51470298 2598 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2599 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2600 if (!filename_is_null(ssh->cfg.keyfile)) {
2601 if (!rsakey_pubblob(&ssh->cfg.keyfile,
51470298 2602 &s->publickey_blob, &s->publickey_bloblen))
2603 s->publickey_blob = NULL;
396778f1 2604 } else
51470298 2605 s->publickey_blob = NULL;
7cca0d81 2606
51470298 2607 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2608 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2609
51470298 2610 if (agent_exists() && !s->tried_agent) {
32874aea 2611 /*
2612 * Attempt RSA authentication using Pageant.
2613 */
32874aea 2614 void *r;
2615
51470298 2616 s->authed = FALSE;
2617 s->tried_agent = 1;
32874aea 2618 logevent("Pageant is running. Requesting keys.");
2619
2620 /* Request the keys held by the agent. */
51470298 2621 PUT_32BIT(s->request, 1);
2622 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2623 if (!agent_query(s->request, 5, &r, &s->responselen,
2624 ssh_agent_callback, ssh)) {
2625 do {
2626 crReturn(0);
2627 if (ispkt) {
2628 bombout(("Unexpected data from server while waiting"
2629 " for agent response"));
2630 crStop(0);
2631 }
2632 } while (ispkt || inlen > 0);
2633 r = ssh->agent_response;
2634 s->responselen = ssh->agent_response_len;
2635 }
51470298 2636 s->response = (unsigned char *) r;
2637 if (s->response && s->responselen >= 5 &&
2638 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2639 s->p = s->response + 5;
2640 s->nkeys = GET_32BIT(s->p);
2641 s->p += 4;
32874aea 2642 {
2643 char buf[64];
51470298 2644 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2645 logevent(buf);
2646 }
51470298 2647 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2648 {
2649 char buf[64];
51470298 2650 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2651 logevent(buf);
2652 }
51470298 2653 if (s->publickey_blob &&
2654 !memcmp(s->p, s->publickey_blob,
2655 s->publickey_bloblen)) {
396778f1 2656 logevent("This key matches configured key file");
51470298 2657 s->tried_publickey = 1;
396778f1 2658 }
51470298 2659 s->p += 4;
2660 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2661 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2662 s->commentlen = GET_32BIT(s->p);
2663 s->p += 4;
d8baa528 2664 s->commentp = (char *)s->p;
51470298 2665 s->p += s->commentlen;
2666 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2667 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2668 crWaitUntil(ispkt);
51470298 2669 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2670 logevent("Key refused");
2671 continue;
2672 }
2673 logevent("Received RSA challenge");
51470298 2674 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2675 {
2676 char *agentreq, *q, *ret;
2d466ffd 2677 void *vret;
32874aea 2678 int len, retlen;
2679 len = 1 + 4; /* message type, bit count */
51470298 2680 len += ssh1_bignum_length(s->key.exponent);
2681 len += ssh1_bignum_length(s->key.modulus);
2682 len += ssh1_bignum_length(s->challenge);
32874aea 2683 len += 16; /* session id */
2684 len += 4; /* response format */
3d88e64d 2685 agentreq = snewn(4 + len, char);
32874aea 2686 PUT_32BIT(agentreq, len);
2687 q = agentreq + 4;
2688 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2689 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2690 q += 4;
51470298 2691 q += ssh1_write_bignum(q, s->key.exponent);
2692 q += ssh1_write_bignum(q, s->key.modulus);
2693 q += ssh1_write_bignum(q, s->challenge);
2694 memcpy(q, s->session_id, 16);
32874aea 2695 q += 16;
2696 PUT_32BIT(q, 1); /* response format */
839f10db 2697 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2698 ssh_agent_callback, ssh)) {
2699 sfree(agentreq);
2700 do {
2701 crReturn(0);
2702 if (ispkt) {
2703 bombout(("Unexpected data from server"
2704 " while waiting for agent"
2705 " response"));
2706 crStop(0);
2707 }
2708 } while (ispkt || inlen > 0);
2709 vret = ssh->agent_response;
2710 retlen = ssh->agent_response_len;
2711 } else
2712 sfree(agentreq);
2d466ffd 2713 ret = vret;
32874aea 2714 if (ret) {
2715 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2716 logevent("Sending Pageant's response");
51470298 2717 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2718 PKT_DATA, ret + 5, 16,
2719 PKT_END);
2720 sfree(ret);
2721 crWaitUntil(ispkt);
51470298 2722 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2723 logevent
2724 ("Pageant's response accepted");
2725 if (flags & FLAG_VERBOSE) {
51470298 2726 c_write_str(ssh, "Authenticated using"
2727 " RSA key \"");
2728 c_write(ssh, s->commentp,
2729 s->commentlen);
2730 c_write_str(ssh, "\" from agent\r\n");
32874aea 2731 }
51470298 2732 s->authed = TRUE;
32874aea 2733 } else
2734 logevent
2735 ("Pageant's response not accepted");
2736 } else {
2737 logevent
2738 ("Pageant failed to answer challenge");
2739 sfree(ret);
2740 }
2741 } else {
2742 logevent("No reply received from Pageant");
2743 }
2744 }
51470298 2745 freebn(s->key.exponent);
2746 freebn(s->key.modulus);
2747 freebn(s->challenge);
2748 if (s->authed)
32874aea 2749 break;
2750 }
2751 }
51470298 2752 if (s->authed)
32874aea 2753 break;
2754 }
9a30e26b 2755 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 2756 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2757
86916870 2758 if (ssh->cfg.try_tis_auth &&
51470298 2759 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2760 !s->tis_auth_refused) {
2761 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2762 logevent("Requested TIS authentication");
51470298 2763 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2764 crWaitUntil(ispkt);
51470298 2765 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2766 logevent("TIS authentication declined");
2767 if (flags & FLAG_INTERACTIVE)
51470298 2768 c_write_str(ssh, "TIS authentication refused.\r\n");
2769 s->tis_auth_refused = 1;
614a20a0 2770 continue;
32874aea 2771 } else {
51470298 2772 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2773 logevent("Received TIS challenge");
51470298 2774 if (challengelen > sizeof(s->prompt) - 1)
2775 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2776 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2777 /* Prompt heuristic comes from OpenSSH */
51470298 2778 strncpy(s->prompt + challengelen,
2779 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2780 "": "\r\nResponse: ",
51470298 2781 (sizeof s->prompt) - challengelen);
2782 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2783 }
2784 }
86916870 2785 if (ssh->cfg.try_tis_auth &&
51470298 2786 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2787 !s->ccard_auth_refused) {
2788 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2789 logevent("Requested CryptoCard authentication");
51470298 2790 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2791 crWaitUntil(ispkt);
51470298 2792 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2793 logevent("CryptoCard authentication declined");
51470298 2794 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2795 s->ccard_auth_refused = 1;
614a20a0 2796 continue;
32874aea 2797 } else {
51470298 2798 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2799 logevent("Received CryptoCard challenge");
51470298 2800 if (challengelen > sizeof(s->prompt) - 1)
2801 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2802 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2803 strncpy(s->prompt + challengelen,
2804 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2805 "" : "\r\nResponse: ",
51470298 2806 sizeof(s->prompt) - challengelen);
2807 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2808 }
2809 }
51470298 2810 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2811 sprintf(s->prompt, "%.90s@%.90s's password: ",
2812 s->username, ssh->savedhost);
32874aea 2813 }
51470298 2814 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2815 char *comment = NULL;
231ee168 2816 int type;
2817 char msgbuf[256];
32874aea 2818 if (flags & FLAG_VERBOSE)
51470298 2819 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 2820 logeventf(ssh, "Trying public key \"%s\"",
2821 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 2822 type = key_type(&ssh->cfg.keyfile);
231ee168 2823 if (type != SSH_KEYTYPE_SSH1) {
2824 sprintf(msgbuf, "Key is of wrong type (%s)",
2825 key_type_to_str(type));
2826 logevent(msgbuf);
51470298 2827 c_write_str(ssh, msgbuf);
2828 c_write_str(ssh, "\r\n");
2829 s->tried_publickey = 1;
231ee168 2830 continue;
2831 }
9a30e26b 2832 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 2833 if (flags & FLAG_VERBOSE)
51470298 2834 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2835 goto tryauth;
2836 }
51470298 2837 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2838 sfree(comment);
2839 }
a52f067e 2840
614a20a0 2841 /*
2842 * Show password prompt, having first obtained it via a TIS
2843 * or CryptoCard exchange if we're doing TIS or CryptoCard
2844 * authentication.
2845 */
fa17a66e 2846 if (ssh_get_line) {
51470298 2847 if (!ssh_get_line(s->prompt, s->password,
2848 sizeof(s->password), TRUE)) {
32874aea 2849 /*
2850 * get_line failed to get a password (for example
2851 * because one was supplied on the command line
2852 * which has already failed to work). Terminate.
2853 */
51470298 2854 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2855 PKT_STR, "No more passwords available to try",
2856 PKT_END);
247308b5 2857 logevent("Unable to authenticate");
a8327734 2858 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 2859 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2860 crStop(1);
32874aea 2861 }
fb09bf1c 2862 } else {
614a20a0 2863 /* Prompt may have come from server. We've munged it a bit, so
2864 * we know it to be zero-terminated at least once. */
51470298 2865 int ret; /* need not be saved over crReturn */
2866 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2867 s->pos = 0;
0405e71f 2868
51470298 2869 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2870 do {
32874aea 2871 crWaitUntil(!ispkt);
51470298 2872 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2873 } while (ret == 0);
2874 if (ret < 0)
2875 cleanup_exit(0);
51470298 2876 c_write_str(ssh, "\r\n");
32874aea 2877 }
2878
2879 tryauth:
51470298 2880 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2881 /*
2882 * Try public key authentication with the specified
2883 * key file.
2884 */
51470298 2885 s->tried_publickey = 1;
2886
2887 {
9a30e26b 2888 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
51470298 2889 if (ret == 0) {
2890 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 2891 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
51470298 2892 c_write_str(ssh, ".\r\n");
2893 continue; /* go and try password */
2894 }
2895 if (ret == -1) {
2896 c_write_str(ssh, "Wrong passphrase.\r\n");
2897 s->tried_publickey = 0;
2898 continue; /* try again */
2899 }
32874aea 2900 }
2901
2902 /*
2903 * Send a public key attempt.
2904 */
51470298 2905 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2906 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2907
2908 crWaitUntil(ispkt);
51470298 2909 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2910 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2911 continue; /* go and try password */
2912 }
51470298 2913 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 2914 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 2915 crStop(0);
32874aea 2916 }
32874aea 2917
51470298 2918 {
2919 int i;
2920 unsigned char buffer[32];
2921 Bignum challenge, response;
2922
2923 ssh1_read_bignum(ssh->pktin.body, &challenge);
2924 response = rsadecrypt(challenge, &s->key);
2925 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2926
51470298 2927 for (i = 0; i < 32; i++) {
2928 buffer[i] = bignum_byte(response, 31 - i);
2929 }
2930
2931 MD5Init(&md5c);
2932 MD5Update(&md5c, buffer, 32);
2933 MD5Update(&md5c, s->session_id, 16);
2934 MD5Final(buffer, &md5c);
32874aea 2935
51470298 2936 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2937 PKT_DATA, buffer, 16, PKT_END);
2938
2939 freebn(challenge);
2940 freebn(response);
2941 }
32874aea 2942
2943 crWaitUntil(ispkt);
51470298 2944 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2945 if (flags & FLAG_VERBOSE)
51470298 2946 c_write_str(ssh, "Failed to authenticate with"
2947 " our public key.\r\n");
32874aea 2948 continue; /* go and try password */
51470298 2949 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2950 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 2951 crStop(0);
32874aea 2952 }
2953
2954 break; /* we're through! */
2955 } else {
51470298 2956 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2957 /*
2958 * Defence against traffic analysis: we send a
2959 * whole bunch of packets containing strings of
2960 * different lengths. One of these strings is the
2961 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2962 * The others are all random data in
2963 * SSH1_MSG_IGNORE packets. This way a passive
2964 * listener can't tell which is the password, and
2965 * hence can't deduce the password length.
2966 *
2967 * Anybody with a password length greater than 16
2968 * bytes is going to have enough entropy in their
2969 * password that a listener won't find it _that_
2970 * much help to know how long it is. So what we'll
2971 * do is:
2972 *
2973 * - if password length < 16, we send 15 packets
2974 * containing string lengths 1 through 15
2975 *
2976 * - otherwise, we let N be the nearest multiple
2977 * of 8 below the password length, and send 8
2978 * packets containing string lengths N through
2979 * N+7. This won't obscure the order of
2980 * magnitude of the password length, but it will
2981 * introduce a bit of extra uncertainty.
2982 *
2983 * A few servers (the old 1.2.18 through 1.2.22)
2984 * can't deal with SSH1_MSG_IGNORE. For these
2985 * servers, we need an alternative defence. We make
2986 * use of the fact that the password is interpreted
2987 * as a C string: so we can append a NUL, then some
2988 * random data.
bd358db1 2989 *
2990 * One server (a Cisco one) can deal with neither
2991 * SSH1_MSG_IGNORE _nor_ a padded password string.
2992 * For this server we are left with no defences
2993 * against password length sniffing.
32874aea 2994 */
51470298 2995 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2996 /*
2997 * The server can deal with SSH1_MSG_IGNORE, so
2998 * we can use the primary defence.
2999 */
32874aea 3000 int bottom, top, pwlen, i;
3001 char *randomstr;
3002
51470298 3003 pwlen = strlen(s->password);
32874aea 3004 if (pwlen < 16) {
3005 bottom = 0; /* zero length passwords are OK! :-) */
3006 top = 15;
3007 } else {
3008 bottom = pwlen & ~7;
3009 top = bottom + 7;
3010 }
3011
3012 assert(pwlen >= bottom && pwlen <= top);
3013
3d88e64d 3014 randomstr = snewn(top + 1, char);
32874aea 3015
3016 for (i = bottom; i <= top; i++) {
3017 if (i == pwlen)
51470298 3018 defer_packet(ssh, s->pwpkt_type,
3019 PKT_STR, s->password, PKT_END);
32874aea 3020 else {
3021 for (j = 0; j < i; j++) {
3022 do {
3023 randomstr[j] = random_byte();
3024 } while (randomstr[j] == '\0');
3025 }
3026 randomstr[i] = '\0';
51470298 3027 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3028 PKT_STR, randomstr, PKT_END);
3029 }
3030 }
bd358db1 3031 logevent("Sending password with camouflage packets");
51470298 3032 ssh_pkt_defersend(ssh);
bd358db1 3033 }
51470298 3034 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3035 /*
3036 * The server can't deal with SSH1_MSG_IGNORE
3037 * but can deal with padded passwords, so we
3038 * can use the secondary defence.
3039 */
bd358db1 3040 char string[64];
51470298 3041 char *ss;
bd358db1 3042 int len;
3043
51470298 3044 len = strlen(s->password);
bd358db1 3045 if (len < sizeof(string)) {
51470298 3046 ss = string;
3047 strcpy(string, s->password);
bd358db1 3048 len++; /* cover the zero byte */
3049 while (len < sizeof(string)) {
3050 string[len++] = (char) random_byte();
3051 }
3052 } else {
51470298 3053 ss = s->password;
bd358db1 3054 }
3055 logevent("Sending length-padded password");
51470298 3056 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3057 PKT_DATA, ss, len, PKT_END);
bd358db1 3058 } else {
3059 /*
3060 * The server has _both_
3061 * BUG_CHOKES_ON_SSH1_IGNORE and
3062 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3063 * therefore nothing we can do.
3064 */
3065 int len;
51470298 3066 len = strlen(s->password);
bd358db1 3067 logevent("Sending unpadded password");
51470298 3068 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
3069 PKT_DATA, s->password, len, PKT_END);
32874aea 3070 }
3071 } else {
51470298 3072 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 3073 }
3074 }
c5e9c988 3075 logevent("Sent password");
51470298 3076 memset(s->password, 0, strlen(s->password));
fb09bf1c 3077 crWaitUntil(ispkt);
51470298 3078 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3079 if (flags & FLAG_VERBOSE)
51470298 3080 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3081 logevent("Authentication refused");
51470298 3082 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3083 bombout(("Strange packet received, type %d", ssh->pktin.type));
7ffdbc1a 3084 crStop(0);
374330e2 3085 }
3086 }
3087
c5e9c988 3088 logevent("Authentication successful");
3089
fb09bf1c 3090 crFinish(1);
3091}
3092
32874aea 3093void sshfwd_close(struct ssh_channel *c)
3094{
51470298 3095 Ssh ssh = c->ssh;
3096
36f94d1f 3097 if (ssh->state != SSH_STATE_SESSION) {
3098 assert(ssh->state == SSH_STATE_CLOSED);
3099 return;
3100 }
3101
80e48603 3102 if (c && !c->closes) {
4ed34d25 3103 /*
3104 * If the channel's remoteid is -1, we have sent
3105 * CHANNEL_OPEN for this channel, but it hasn't even been
3106 * acknowledged by the server. So we must set a close flag
3107 * on it now, and then when the server acks the channel
3108 * open, we can close it then.
3109 */
36cac739 3110 if (((int)c->remoteid) != -1) {
51470298 3111 if (ssh->version == 1) {
3112 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3113 PKT_END);
3114 } else {
51470298 3115 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3116 ssh2_pkt_adduint32(ssh, c->remoteid);
3117 ssh2_pkt_send(ssh);
4ed34d25 3118 }
32874aea 3119 }
0357890f 3120 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3121 if (c->type == CHAN_X11) {
3122 c->u.x11.s = NULL;
d74d141c 3123 logevent("Forwarded X11 connection terminated");
4ed34d25 3124 } else if (c->type == CHAN_SOCKDATA ||
3125 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3126 c->u.pfd.s = NULL;
3127 logevent("Forwarded port closed");
32874aea 3128 }
3129 }
3130}
3131
5471d09a 3132int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3133{
51470298 3134 Ssh ssh = c->ssh;
3135
36f94d1f 3136 if (ssh->state != SSH_STATE_SESSION) {
3137 assert(ssh->state == SSH_STATE_CLOSED);
3138 return 0;
3139 }
3140
51470298 3141 if (ssh->version == 1) {
3142 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3143 PKT_INT, c->remoteid,
3144 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 3145 /*
3146 * In SSH1 we can return 0 here - implying that forwarded
3147 * connections are never individually throttled - because
3148 * the only circumstance that can cause throttling will be
3149 * the whole SSH connection backing up, in which case
3150 * _everything_ will be throttled as a whole.
3151 */
3152 return 0;
783415f8 3153 } else {
32874aea 3154 ssh2_add_channel_data(c, buf, len);
5471d09a 3155 return ssh2_try_send(c);
3156 }
3157}
3158
3159void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3160{
51470298 3161 Ssh ssh = c->ssh;
3162
36f94d1f 3163 if (ssh->state != SSH_STATE_SESSION) {
3164 assert(ssh->state == SSH_STATE_CLOSED);
3165 return;
3166 }
3167
51470298 3168 if (ssh->version == 1) {
5471d09a 3169 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3170 c->v.v1.throttling = 0;
51470298 3171 ssh1_throttle(ssh, -1);
5471d09a 3172 }
3173 } else {
3174 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3175 }
9c964e85 3176}
3177
51470298 3178static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3179{
51470298 3180 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3181
3182 random_init();
3183
51470298 3184 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3185 crReturnV;
85ee8208 3186 }
51470298 3187 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3188 crReturnV;
fb09bf1c 3189
86916870 3190 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3191 logevent("Requesting agent forwarding");
51470298 3192 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3193 do {
3194 crReturnV;
3195 } while (!ispkt);
51470298 3196 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3197 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3198 bombout(("Protocol confusion"));
7ffdbc1a 3199 crStopV;
51470298 3200 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3201 logevent("Agent forwarding refused");
3202 } else {
3203 logevent("Agent forwarding enabled");
51470298 3204 ssh->agentfwd_enabled = TRUE;
db7d555c 3205 }
dacbd0e8 3206 }
3207
86916870 3208 if (ssh->cfg.x11_forward) {
32874aea 3209 char proto[20], data[64];
3210 logevent("Requesting X11 forwarding");
302121de 3211 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3212 data, sizeof(data), ssh->cfg.x11_auth);
3213 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3214 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3215 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3216 PKT_STR, proto, PKT_STR, data,
86916870 3217 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3218 PKT_END);
32874aea 3219 } else {
51470298 3220 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3221 PKT_STR, proto, PKT_STR, data, PKT_END);
3222 }
3223 do {
3224 crReturnV;
3225 } while (!ispkt);
51470298 3226 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3227 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3228 bombout(("Protocol confusion"));
7ffdbc1a 3229 crStopV;
51470298 3230 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3231 logevent("X11 forwarding refused");
3232 } else {
3233 logevent("X11 forwarding enabled");
51470298 3234 ssh->X11_fwd_enabled = TRUE;
9c964e85 3235 }
3236 }
3237
d74d141c 3238 {
9bf696b1 3239 char type;
d74d141c 3240 int n;
a4fc0d74 3241 int sport,dport,sserv,dserv;
6ee9b735 3242 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3243
51470298 3244 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3245 /* Add port forwardings. */
86916870 3246 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3247 while (*ssh->portfwd_strptr) {
3248 type = *ssh->portfwd_strptr++;
6ee9b735 3249 saddr[0] = '\0';
d74d141c 3250 n = 0;
6ee9b735 3251 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3252 if (*ssh->portfwd_strptr == ':') {
3253 /*
3254 * We've seen a colon in the middle of the
3255 * source port number. This means that
3256 * everything we've seen until now is the
3257 * source _address_, so we'll move it into
3258 * saddr and start sports from the beginning
3259 * again.
3260 */
3261 ssh->portfwd_strptr++;
3262 sports[n] = '\0';
3263 strcpy(saddr, sports);
3264 n = 0;
3265 }
3266 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3267 }
d74d141c 3268 sports[n] = 0;
820ebe3b 3269 if (type != 'D') {
3270 if (*ssh->portfwd_strptr == '\t')
3271 ssh->portfwd_strptr++;
3272 n = 0;
3273 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3274 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3275 }
3276 host[n] = 0;
3277 if (*ssh->portfwd_strptr == ':')
3278 ssh->portfwd_strptr++;
3279 n = 0;
3280 while (*ssh->portfwd_strptr) {
3281 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3282 }
3283 dports[n] = 0;
51470298 3284 ssh->portfwd_strptr++;
820ebe3b 3285 dport = atoi(dports);
3286 dserv = 0;
3287 if (dport == 0) {
3288 dserv = 1;
3289 dport = net_service_lookup(dports);
3290 if (!dport) {
3291 logeventf(ssh, "Service lookup failed for"
3292 " destination port \"%s\"", dports);
3293 }
a4fc0d74 3294 }
820ebe3b 3295 } else {
3296 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3297 dport = dserv = -1;
a4fc0d74 3298 }
d74d141c 3299 sport = atoi(sports);
a4fc0d74 3300 sserv = 0;
3301 if (sport == 0) {
3302 sserv = 1;
68a49acb 3303 sport = net_service_lookup(sports);
3304 if (!sport) {
57356d63 3305 logeventf(ssh, "Service lookup failed for source"
3306 " port \"%s\"", sports);
a4fc0d74 3307 }
3308 }
d74d141c 3309 if (sport && dport) {
3310 if (type == 'L') {
6ee9b735 3311 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 3312 sport, ssh, &ssh->cfg);
6ee9b735 3313 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3314 " forwarding to %s:%.*s%.*s%d%.*s",
3315 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3316 (int)(*saddr?1:0), ":",
57356d63 3317 (int)(sserv ? strlen(sports) : 0), sports,
3318 sserv, "(", sport, sserv, ")",
3319 host,
3320 (int)(dserv ? strlen(dports) : 0), dports,
3321 dserv, "(", dport, dserv, ")");
820ebe3b 3322 } else if (type == 'D') {
3323 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3324 sport, ssh, &ssh->cfg);
3325 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3326 " doing SOCKS dynamic forwarding",
3327 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3328 (int)(*saddr?1:0), ":",
3329 (int)(sserv ? strlen(sports) : 0), sports,
3330 sserv, "(", sport, sserv, ")");
d74d141c 3331 } else {
3332 struct ssh_rportfwd *pf;
3d88e64d 3333 pf = snew(struct ssh_rportfwd);
bc240b21 3334 strcpy(pf->dhost, host);
3335 pf->dport = dport;
6ee9b735 3336 if (saddr) {
3337 logeventf(ssh,
3338 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3339 saddr, sport);
3340 }
51470298 3341 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3342 logeventf(ssh,
3343 "Duplicate remote port forwarding to %s:%d",
3344 host, dport);
bc240b21 3345 sfree(pf);
d74d141c 3346 } else {
57356d63 3347 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3348 " forward to %s:%.*s%.*s%d%.*s",
3349 (int)(sserv ? strlen(sports) : 0), sports,
3350 sserv, "(", sport, sserv, ")",
3351 host,
3352 (int)(dserv ? strlen(dports) : 0), dports,
3353 dserv, "(", dport, dserv, ")");
51470298 3354 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3355 PKT_INT, sport,
3356 PKT_STR, host,
3357 PKT_INT, dport,
3358 PKT_END);
9bf696b1 3359 do {
3360 crReturnV;
3361 } while (!ispkt);
51470298 3362 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3363 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3364 bombout(("Protocol confusion"));
7ffdbc1a 3365 crStopV;
51470298 3366 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3367 c_write_str(ssh, "Server refused port"
3368 " forwarding\r\n");
9bf696b1 3369 }
3370 logevent("Remote port forwarding enabled");
d74d141c 3371 }
3372 }
3373 }
3374 }
3375 }
3376
86916870 3377 if (!ssh->cfg.nopty) {
51470298 3378 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3379 PKT_STR, ssh->cfg.termtype,
51470298 3380 PKT_INT, ssh->term_height,
3381 PKT_INT, ssh->term_width,
32874aea 3382 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3383 ssh->state = SSH_STATE_INTERMED;
32874aea 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 to allocate pty\r\n");
3393 ssh->editing = ssh->echoing = 1;
32874aea 3394 }
c5e9c988 3395 logevent("Allocated pty");
0965bee0 3396 } else {
51470298 3397 ssh->editing = ssh->echoing = 1;
374330e2 3398 }
3399
86916870 3400 if (ssh->cfg.compression) {
51470298 3401 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3402 do {
3403 crReturnV;
3404 } while (!ispkt);
51470298 3405 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3406 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3407 bombout(("Protocol confusion"));
7ffdbc1a 3408 crStopV;
51470298 3409 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3410 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3411 }
4ba9b64b 3412 logevent("Started compression");
51470298 3413 ssh->v1_compressing = TRUE;
5366aed8 3414 ssh->cs_comp_ctx = zlib_compress_init();
3415 logevent("Initialised zlib (RFC1950) compression");
3416 ssh->sc_comp_ctx = zlib_decompress_init();
3417 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3418 }
3419
fd5e5847 3420 /*
3421 * Start the shell or command.
3422 *
3423 * Special case: if the first-choice command is an SSH2
3424 * subsystem (hence not usable here) and the second choice
3425 * exists, we fall straight back to that.
3426 */
3427 {
86916870 3428 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3429
86916870 3430 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3431 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3432 ssh->fallback_cmd = TRUE;
fd5e5847 3433 }
3434 if (*cmd)
51470298 3435 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3436 else
51470298 3437 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3438 logevent("Started session");
3439 }
374330e2 3440
51470298 3441 ssh->state = SSH_STATE_SESSION;
3442 if (ssh->size_needed)
3443 ssh_size(ssh, ssh->term_width, ssh->term_height);
3444 if (ssh->eof_needed)
3445 ssh_special(ssh, TS_EOF);
374330e2 3446
b9d7bcad 3447 if (ssh->ldisc)
3448 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3449 ssh->send_ok = 1;
3450 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3451 while (1) {
3452 crReturnV;
3453 if (ispkt) {
51470298 3454 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3455 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3456 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3457 int bufsize =
51470298 3458 from_backend(ssh->frontend,
3459 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
d8baa528 3460 (char *)(ssh->pktin.body) + 4, len);
51470298 3461 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3462 ssh->v1_stdout_throttling = 1;
3463 ssh1_throttle(ssh, +1);
5471d09a 3464 }
51470298 3465 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3bb2f322 3466 ssh_closing((Plug)ssh, NULL, 0, 0);
c5e9c988 3467 logevent("Received disconnect request");
7ffdbc1a 3468 crStopV;
51470298 3469 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3470 /* Remote side is trying to open a channel to talk to our
3471 * X-Server. Give them back a local channel number. */
3472 struct ssh_channel *c;
9c964e85 3473
3474 logevent("Received X11 connect request");
3475 /* Refuse if X11 forwarding is disabled. */
51470298 3476 if (!ssh->X11_fwd_enabled) {
3477 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3478 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3479 logevent("Rejected X11 connect request");
3480 } else {
3d88e64d 3481 c = snew(struct ssh_channel);
51470298 3482 c->ssh = ssh;
9c964e85 3483
86916870 3484 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3485 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
32874aea 3486 logevent("opening X11 forward connection failed");
3487 sfree(c);
51470298 3488 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3489 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3490 PKT_END);
9c964e85 3491 } else {
32874aea 3492 logevent
3493 ("opening X11 forward connection succeeded");
51470298 3494 c->remoteid = GET_32BIT(ssh->pktin.body);
3495 c->localid = alloc_channel_id(ssh);
32874aea 3496 c->closes = 0;
5471d09a 3497 c->v.v1.throttling = 0;
32874aea 3498 c->type = CHAN_X11; /* identify channel type */
51470298 3499 add234(ssh->channels, c);
3500 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3501 PKT_INT, c->remoteid, PKT_INT,
3502 c->localid, PKT_END);
3503 logevent("Opened X11 forward channel");
9c964e85 3504 }
3505 }
51470298 3506 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3507 /* Remote side is trying to open a channel to talk to our
3508 * agent. Give them back a local channel number. */
3509 struct ssh_channel *c;
db7d555c 3510
3511 /* Refuse if agent forwarding is disabled. */
51470298 3512 if (!ssh->agentfwd_enabled) {
3513 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3514 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3515 } else {
3d88e64d 3516 c = snew(struct ssh_channel);
51470298 3517 c->ssh = ssh;
3518 c->remoteid = GET_32BIT(ssh->pktin.body);
3519 c->localid = alloc_channel_id(ssh);
db7d555c 3520 c->closes = 0;
5471d09a 3521 c->v.v1.throttling = 0;
32874aea 3522 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3523 c->u.a.lensofar = 0;
51470298 3524 add234(ssh->channels, c);
3525 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3526 PKT_INT, c->remoteid, PKT_INT, c->localid,
3527 PKT_END);
3528 }
51470298 3529 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3530 /* Remote side is trying to open a channel to talk to a
3531 * forwarded port. Give them back a local channel number. */
3532 struct ssh_channel *c;
3533 struct ssh_rportfwd pf;
3534 int hostsize, port;
3535 char host[256], buf[1024];
cbe2d68f 3536 char *p, *h;
3537 const char *e;
3d88e64d 3538 c = snew(struct ssh_channel);
51470298 3539 c->ssh = ssh;
d74d141c 3540
51470298 3541 hostsize = GET_32BIT(ssh->pktin.body+4);
d8baa528 3542 for (h = host, p = (char *)(ssh->pktin.body+8);
3543 hostsize != 0; hostsize--) {
d74d141c 3544 if (h+1 < host+sizeof(host))
3545 *h++ = *p;
95bc8819 3546 p++;
d74d141c 3547 }
3548 *h = 0;
3549 port = GET_32BIT(p);
3550
bc240b21 3551 strcpy(pf.dhost, host);
3552 pf.dport = port;
d74d141c 3553
51470298 3554 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3555 sprintf(buf, "Rejected remote port open request for %s:%d",
3556 host, port);
3557 logevent(buf);
51470298 3558 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3559 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3560 } else {
3561 sprintf(buf, "Received remote port open request for %s:%d",
3562 host, port);
3563 logevent(buf);
e8fa8f62 3564 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
d74d141c 3565 if (e != NULL) {
3566 char buf[256];
3567 sprintf(buf, "Port open failed: %s", e);
3568 logevent(buf);
3569 sfree(c);
51470298 3570 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3571 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3572 PKT_END);
3573 } else {
51470298 3574 c->remoteid = GET_32BIT(ssh->pktin.body);
3575 c->localid = alloc_channel_id(ssh);
d74d141c 3576 c->closes = 0;
5471d09a 3577 c->v.v1.throttling = 0;
d74d141c 3578 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3579 add234(ssh->channels, c);
3580 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3581 PKT_INT, c->remoteid, PKT_INT,
3582 c->localid, PKT_END);
3583 logevent("Forwarded port opened successfully");
3584 }
3585 }
3586
51470298 3587 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3588 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3589 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3590 struct ssh_channel *c;
3591
51470298 3592 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3593 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3594 c->remoteid = localid;
3595 c->type = CHAN_SOCKDATA;
7781f316 3596 c->v.v1.throttling = 0;
bc240b21 3597 pfd_confirm(c->u.pfd.s);
3598 }
d74d141c 3599
4ed34d25 3600 if (c && c->closes) {
3601 /*
3602 * We have a pending close on this channel,
3603 * which we decided on before the server acked
3604 * the channel open. So now we know the
3605 * remoteid, we can close it again.
3606 */
51470298 3607 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3608 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3609 }
3610
51470298 3611 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3612 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
724cface 3613 struct ssh_channel *c;
3614
51470298 3615 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3616 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3617 logevent("Forwarded connection refused by server");
3618 pfd_close(c->u.pfd.s);
51470298 3619 del234(ssh->channels, c);
724cface 3620 sfree(c);
3621 }
3622
51470298 3623 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3624 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3625 /* Remote side closes a channel. */
51470298 3626 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3627 struct ssh_channel *c;
51470298 3628 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3629 if (c && ((int)c->remoteid) != -1) {
32874aea 3630 int closetype;
3631 closetype =
51470298 3632 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3633
783415f8 3634 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3635 logevent("Forwarded X11 connection terminated");
9c964e85 3636 assert(c->u.x11.s != NULL);
3637 x11_close(c->u.x11.s);
3638 c->u.x11.s = NULL;
3639 }
d74d141c 3640 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3641 logevent("Forwarded port closed");
3642 assert(c->u.pfd.s != NULL);
3643 pfd_close(c->u.pfd.s);
3644 c->u.pfd.s = NULL;
3645 }
0357890f 3646
3647 c->closes |= (closetype << 2); /* seen this message */
3648 if (!(c->closes & closetype)) {
51470298 3649 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3650 PKT_END);
3651 c->closes |= closetype; /* sent it too */
3652 }
3653
3654 if (c->closes == 15) {
51470298 3655 del234(ssh->channels, c);
32874aea 3656 sfree(c);
3657 }
d0d844c1 3658 } else {
6b5cf8b4 3659 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3660 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3661 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3662 i));
7ffdbc1a 3663 crStopV;
32874aea 3664 }
51470298 3665 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3666 /* Data sent down one of our channels. */
51470298 3667 int i = GET_32BIT(ssh->pktin.body);
3668 int len = GET_32BIT(ssh->pktin.body + 4);
3669 unsigned char *p = ssh->pktin.body + 8;
32874aea 3670 struct ssh_channel *c;
51470298 3671 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3672 if (c) {
7ffdbc1a 3673 int bufsize = 0;
32874aea 3674 switch (c->type) {
3675 case CHAN_X11:
d8baa528 3676 bufsize = x11_send(c->u.x11.s, (char *)p, len);
9c964e85 3677 break;
d74d141c 3678 case CHAN_SOCKDATA:
d8baa528 3679 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
bc240b21 3680 break;
32874aea 3681 case CHAN_AGENT:
3682 /* Data for an agent message. Buffer it. */
3683 while (len > 0) {
3684 if (c->u.a.lensofar < 4) {
3685 int l = min(4 - c->u.a.lensofar, len);
3686 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3687 l);
3688 p += l;
3689 len -= l;
3690 c->u.a.lensofar += l;
3691 }
3692 if (c->u.a.lensofar == 4) {
3693 c->u.a.totallen =
3694 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 3695 c->u.a.message = snewn(c->u.a.totallen,
3696 unsigned char);
32874aea 3697 memcpy(c->u.a.message, c->u.a.msglen, 4);
3698 }
3699 if (c->u.a.lensofar >= 4 && len > 0) {
3700 int l =
3701 min(c->u.a.totallen - c->u.a.lensofar,
3702 len);
3703 memcpy(c->u.a.message + c->u.a.lensofar, p,
3704 l);
3705 p += l;
3706 len -= l;
3707 c->u.a.lensofar += l;
3708 }
3709 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 3710 void *reply;
32874aea 3711 int replylen;
839f10db 3712 if (agent_query(c->u.a.message,
3713 c->u.a.totallen,
3714 &reply, &replylen,
3715 ssh_agentf_callback, c))
3716 ssh_agentf_callback(c, reply, replylen);
32874aea 3717 sfree(c->u.a.message);
3718 c->u.a.lensofar = 0;
3719 }
3720 }
5471d09a 3721 bufsize = 0; /* agent channels never back up */
32874aea 3722 break;
3723 }
90347b95 3724 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3725 c->v.v1.throttling = 1;
51470298 3726 ssh1_throttle(ssh, +1);
5471d09a 3727 }
32874aea 3728 }
51470298 3729 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3730 /* may be from EXEC_SHELL on some servers */
51470298 3731 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3732 /* may be from EXEC_SHELL on some servers
374330e2 3733 * if no pty is available or in other odd cases. Ignore */
51470298 3734 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3735 char buf[100];
51470298 3736 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3737 sprintf(buf, "Server sent command exit status %d",
51470298 3738 ssh->exitcode);
d8d6c7e5 3739 logevent(buf);
51470298 3740 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3741 /*
3742 * In case `helpful' firewalls or proxies tack
3743 * extra human-readable text on the end of the
3744 * session which we might mistake for another
3745 * encrypted packet, we close the session once
3746 * we've sent EXIT_CONFIRMATION.
3747 */
3bb2f322 3748 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3749 crStopV;
374330e2 3750 } else {
6b5cf8b4 3751 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 3752 crStopV;
374330e2 3753 }
3754 } else {
8df7a775 3755 while (inlen > 0) {
3756 int len = min(inlen, 512);
51470298 3757 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3758 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3759 in += len;
3760 inlen -= len;
3761 }
374330e2 3762 }
3763 }
3764
3765 crFinishV;
3766}
3767
3768/*
e5574168 3769 * Utility routine for decoding comma-separated strings in KEXINIT.
3770 */
32874aea 3771static int in_commasep_string(char *needle, char *haystack, int haylen)
3772{
57356d63 3773 int needlen;
3774 if (!needle || !haystack) /* protect against null pointers */
3775 return 0;
3776 needlen = strlen(needle);
e5574168 3777 while (1) {
32874aea 3778 /*
3779 * Is it at the start of the string?
3780 */
3781 if (haylen >= needlen && /* haystack is long enough */
3782 !memcmp(needle, haystack, needlen) && /* initial match */
3783 (haylen == needlen || haystack[needlen] == ',')
3784 /* either , or EOS follows */
3785 )
3786 return 1;
3787 /*
3788 * If not, search for the next comma and resume after that.
3789 * If no comma found, terminate.
3790 */
3791 while (haylen > 0 && *haystack != ',')
3792 haylen--, haystack++;
3793 if (haylen == 0)
3794 return 0;
3795 haylen--, haystack++; /* skip over comma itself */
e5574168 3796 }
3797}
3798
3799/*
d39f364a 3800 * SSH2 key creation method.
3801 */
d8baa528 3802static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3803 unsigned char *sessid, char chr,
3804 unsigned char *keyspace)
32874aea 3805{
d39f364a 3806 SHA_State s;
3807 /* First 20 bytes. */
3808 SHA_Init(&s);
51470298 3809 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3810 sha_mpint(&s, K);
d39f364a 3811 SHA_Bytes(&s, H, 20);
3812 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3813 SHA_Bytes(&s, sessid, 20);
d39f364a 3814 SHA_Final(&s, keyspace);
3815 /* Next 20 bytes. */
3816 SHA_Init(&s);
51470298 3817 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3818 sha_mpint(&s, K);
d39f364a 3819 SHA_Bytes(&s, H, 20);
3820 SHA_Bytes(&s, keyspace, 20);
32874aea 3821 SHA_Final(&s, keyspace + 20);
d39f364a 3822}
3823
3824/*
7cca0d81 3825 * Handle the SSH2 transport layer.
e5574168 3826 */
51470298 3827static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3828{
51470298 3829 struct do_ssh2_transport_state {
3830 int nbits, pbits, warn;
3831 Bignum p, g, e, f, K;
3832 int kex_init_value, kex_reply_value;
3833 const struct ssh_mac **maclist;
3834 int nmacs;
3835 const struct ssh2_cipher *cscipher_tobe;
3836 const struct ssh2_cipher *sccipher_tobe;
3837 const struct ssh_mac *csmac_tobe;
3838 const struct ssh_mac *scmac_tobe;
3839 const struct ssh_compress *cscomp_tobe;
3840 const struct ssh_compress *sccomp_tobe;
3841 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3842 int hostkeylen, siglen;
3843 void *hkey; /* actual host key */
3844 unsigned char exchange_hash[20];
3845 int n_preferred_ciphers;
3846 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3847 const struct ssh_compress *preferred_comp;
3848 int first_kex;
3849 };
3850 crState(do_ssh2_transport_state);
3851
3852 crBegin(ssh->do_ssh2_transport_crstate);
3853
3854 s->cscipher_tobe = s->sccipher_tobe = NULL;
3855 s->csmac_tobe = s->scmac_tobe = NULL;
3856 s->cscomp_tobe = s->sccomp_tobe = NULL;
3857
7cca0d81 3858 random_init();
51470298 3859 s->first_kex = 1;
e5574168 3860
51470298 3861 {
3862 int i;
3863 /*
3864 * Set up the preferred ciphers. (NULL => warn below here)
3865 */
3866 s->n_preferred_ciphers = 0;
3867 for (i = 0; i < CIPHER_MAX; i++) {
86916870 3868 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 3869 case CIPHER_BLOWFISH:
3870 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3871 break;
3872 case CIPHER_DES:
86916870 3873 if (ssh->cfg.ssh2_des_cbc) {
51470298 3874 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3875 }
3876 break;
3877 case CIPHER_3DES:
3878 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3879 break;
3880 case CIPHER_AES:
3881 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3882 break;
3883 case CIPHER_WARN:
3884 /* Flag for later. Don't bother if it's the last in
3885 * the list. */
3886 if (i < CIPHER_MAX - 1) {
3887 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3888 }
3889 break;
ca20bfcf 3890 }
ca20bfcf 3891 }
5e8358ad 3892 }
ca20bfcf 3893
3894 /*
3895 * Set up preferred compression.
3896 */
86916870 3897 if (ssh->cfg.compression)
51470298 3898 s->preferred_comp = &ssh_zlib;
4ba9b64b 3899 else
51470298 3900 s->preferred_comp = &ssh_comp_none;
5e8358ad 3901
7591b9ff 3902 /*
3903 * Be prepared to work around the buggy MAC problem.
3904 */
51470298 3905 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3906 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3907 else
51470298 3908 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3909
32874aea 3910 begin_key_exchange:
51470298 3911 {
3912 int i, j, cipherstr_started;
3913
3914 /*
3915 * Construct and send our key exchange packet.
3916 */
3917 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3918 for (i = 0; i < 16; i++)
3919 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3920 /* List key exchange algorithms. */
3921 ssh2_pkt_addstring_start(ssh);
3922 for (i = 0; i < lenof(kex_algs); i++) {
3923 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3924 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3925 continue;
3926 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3927 if (i < lenof(kex_algs) - 1)
3928 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3929 }
51470298 3930 /* List server host key algorithms. */
3931 ssh2_pkt_addstring_start(ssh);
3932 for (i = 0; i < lenof(hostkey_algs); i++) {
3933 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3934 if (i < lenof(hostkey_algs) - 1)
3935 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3936 }
51470298 3937 /* List client->server encryption algorithms. */
3938 ssh2_pkt_addstring_start(ssh);
3939 cipherstr_started = 0;
3940 for (i = 0; i < s->n_preferred_ciphers; i++) {
3941 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3942 if (!c) continue; /* warning flag */
3943 for (j = 0; j < c->nciphers; j++) {
3944 if (cipherstr_started)
3945 ssh2_pkt_addstring_str(ssh, ",");
3946 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3947 cipherstr_started = 1;
3948 }
3949 }
3950 /* List server->client encryption algorithms. */
3951 ssh2_pkt_addstring_start(ssh);
3952 cipherstr_started = 0;
3953 for (i = 0; i < s->n_preferred_ciphers; i++) {
3954 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3955 if (!c) continue; /* warning flag */
3956 for (j = 0; j < c->nciphers; j++) {
3957 if (cipherstr_started)
3958 ssh2_pkt_addstring_str(ssh, ",");
3959 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3960 cipherstr_started = 1;
3961 }
3962 }
3963 /* List client->server MAC algorithms. */
3964 ssh2_pkt_addstring_start(ssh);
3965 for (i = 0; i < s->nmacs; i++) {
3966 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3967 if (i < s->nmacs - 1)
3968 ssh2_pkt_addstring_str(ssh, ",");
3969 }
3970 /* List server->client MAC algorithms. */
3971 ssh2_pkt_addstring_start(ssh);
3972 for (i = 0; i < s->nmacs; i++) {
3973 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3974 if (i < s->nmacs - 1)
3975 ssh2_pkt_addstring_str(ssh, ",");
3976 }
3977 /* List client->server compression algorithms. */
3978 ssh2_pkt_addstring_start(ssh);
3979 for (i = 0; i < lenof(compressions) + 1; i++) {
3980 const struct ssh_compress *c =
3981 i == 0 ? s->preferred_comp : compressions[i - 1];
3982 ssh2_pkt_addstring_str(ssh, c->name);
3983 if (i < lenof(compressions))
3984 ssh2_pkt_addstring_str(ssh, ",");
3985 }
3986 /* List server->client compression algorithms. */
3987 ssh2_pkt_addstring_start(ssh);
3988 for (i = 0; i < lenof(compressions) + 1; i++) {
3989 const struct ssh_compress *c =
3990 i == 0 ? s->preferred_comp : compressions[i - 1];
3991 ssh2_pkt_addstring_str(ssh, c->name);
3992 if (i < lenof(compressions))
3993 ssh2_pkt_addstring_str(ssh, ",");
3994 }
3995 /* List client->server languages. Empty list. */
3996 ssh2_pkt_addstring_start(ssh);
3997 /* List server->client languages. Empty list. */
3998 ssh2_pkt_addstring_start(ssh);
3999 /* First KEX packet does _not_ follow, because we're not that brave. */
4000 ssh2_pkt_addbool(ssh, FALSE);
4001 /* Reserved. */
4002 ssh2_pkt_adduint32(ssh, 0);
e5574168 4003 }
0db56f73 4004
51470298 4005 ssh->exhash = ssh->exhashbase;
4006 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 4007
51470298 4008 ssh2_pkt_send(ssh);
e5574168 4009
32874aea 4010 if (!ispkt)
4011 crWaitUntil(ispkt);
57356d63 4012 if (ssh->pktin.length > 5)
4013 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 4014
4015 /*
4016 * Now examine the other side's KEXINIT to see what we're up
4017 * to.
4018 */
51470298 4019 {
4020 char *str;
4021 int i, j, len;
4022
4023 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4024 bombout(("expected key exchange packet from server"));
7ffdbc1a 4025 crStop(0);
32874aea 4026 }
51470298 4027 ssh->kex = NULL;
4028 ssh->hostkey = NULL;
4029 s->cscipher_tobe = NULL;
4030 s->sccipher_tobe = NULL;
4031 s->csmac_tobe = NULL;
4032 s->scmac_tobe = NULL;
4033 s->cscomp_tobe = NULL;
4034 s->sccomp_tobe = NULL;
4035 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4036 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4037 for (i = 0; i < lenof(kex_algs); i++) {
4038 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4039 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4040 continue;
4041 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4042 ssh->kex = kex_algs[i];
4043 break;
4044 }
32874aea 4045 }
51470298 4046 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4047 for (i = 0; i < lenof(hostkey_algs); i++) {
4048 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4049 ssh->hostkey = hostkey_algs[i];
4050 break;
4051 }
4052 }
4053 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4054 s->warn = 0;
4055 for (i = 0; i < s->n_preferred_ciphers; i++) {
4056 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4057 if (!c) {
4058 s->warn = 1;
4059 } else {
4060 for (j = 0; j < c->nciphers; j++) {
4061 if (in_commasep_string(c->list[j]->name, str, len)) {
4062 s->cscipher_tobe = c->list[j];
4063 break;
4064 }
ca20bfcf 4065 }
32874aea 4066 }
51470298 4067 if (s->cscipher_tobe) {
4068 if (s->warn)
a8327734 4069 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4070 break;
4071 }
32874aea 4072 }
51470298 4073 if (!s->cscipher_tobe) {
6b5cf8b4 4074 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4075 str ? str : "(null)"));
7ffdbc1a 4076 crStop(0);
ca20bfcf 4077 }
0ef8f407 4078
51470298 4079 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4080 s->warn = 0;
4081 for (i = 0; i < s->n_preferred_ciphers; i++) {
4082 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4083 if (!c) {
4084 s->warn = 1;
4085 } else {
4086 for (j = 0; j < c->nciphers; j++) {
4087 if (in_commasep_string(c->list[j]->name, str, len)) {
4088 s->sccipher_tobe = c->list[j];
4089 break;
4090 }
ca20bfcf 4091 }
32874aea 4092 }
51470298 4093 if (s->sccipher_tobe) {
4094 if (s->warn)
a8327734 4095 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4096 break;
4097 }
32874aea 4098 }
51470298 4099 if (!s->sccipher_tobe) {
6b5cf8b4 4100 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4101 str ? str : "(null)"));
7ffdbc1a 4102 crStop(0);
ca20bfcf 4103 }
0ef8f407 4104
51470298 4105 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4106 for (i = 0; i < s->nmacs; i++) {
4107 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4108 s->csmac_tobe = s->maclist[i];
4109 break;
4110 }
32874aea 4111 }
51470298 4112 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4113 for (i = 0; i < s->nmacs; i++) {
4114 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4115 s->scmac_tobe = s->maclist[i];
4116 break;
4117 }
32874aea 4118 }
51470298 4119 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4120 for (i = 0; i < lenof(compressions) + 1; i++) {
4121 const struct ssh_compress *c =
4122 i == 0 ? s->preferred_comp : compressions[i - 1];
4123 if (in_commasep_string(c->name, str, len)) {
4124 s->cscomp_tobe = c;
4125 break;
4126 }
32874aea 4127 }
51470298 4128 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4129 for (i = 0; i < lenof(compressions) + 1; i++) {
4130 const struct ssh_compress *c =
4131 i == 0 ? s->preferred_comp : compressions[i - 1];
4132 if (in_commasep_string(c->name, str, len)) {
4133 s->sccomp_tobe = c;
4134 break;
4135 }
32874aea 4136 }
e5574168 4137 }
e5574168 4138
4139 /*
7bd5a860 4140 * Work out the number of bits of key we will need from the key
4141 * exchange. We start with the maximum key length of either
4142 * cipher...
4143 */
4144 {
32874aea 4145 int csbits, scbits;
7bd5a860 4146
51470298 4147 csbits = s->cscipher_tobe->keylen;
4148 scbits = s->sccipher_tobe->keylen;
4149 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4150 }
4151 /* The keys only have 160-bit entropy, since they're based on
4152 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4153 if (s->nbits > 160)
4154 s->nbits = 160;
7bd5a860 4155
4156 /*
a92dd380 4157 * If we're doing Diffie-Hellman group exchange, start by
4158 * requesting a group.
e5574168 4159 */
51470298 4160 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4161 logevent("Doing Diffie-Hellman group exchange");
51470298 4162 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4163 /*
4164 * Work out how big a DH group we will need to allow that
4165 * much data.
7bd5a860 4166 */
51470298 4167 s->pbits = 512 << ((s->nbits - 1) / 64);
4168 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4169 ssh2_pkt_adduint32(ssh, s->pbits);
4170 ssh2_pkt_send(ssh);
32874aea 4171
4172 crWaitUntil(ispkt);
51470298 4173 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4174 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4175 crStop(0);
32874aea 4176 }
51470298 4177 s->p = ssh2_pkt_getmp(ssh);
4178 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 4179 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4180 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4181 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4182 } else {
51470298 4183 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4184 ssh->kex_ctx = dh_setup_group1();
51470298 4185 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4186 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4187 }
e5574168 4188
a92dd380 4189 logevent("Doing Diffie-Hellman key exchange");
e5574168 4190 /*
a92dd380 4191 * Now generate and send e for Diffie-Hellman.
e5574168 4192 */
27cd7fc2 4193 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 4194 ssh2_pkt_init(ssh, s->kex_init_value);
4195 ssh2_pkt_addmp(ssh, s->e);
4196 ssh2_pkt_send(ssh);
e5574168 4197
4198 crWaitUntil(ispkt);
51470298 4199 if (ssh->pktin.type != s->kex_reply_value) {
6b5cf8b4 4200 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4201 crStop(0);
7cca0d81 4202 }
51470298 4203 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4204 s->f = ssh2_pkt_getmp(ssh);
4205 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4206
27cd7fc2 4207 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4208
51470298 4209 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4210 if (ssh->kex == &ssh_diffiehellman_gex) {
4211 sha_uint32(&ssh->exhash, s->pbits);
4212 sha_mpint(&ssh->exhash, s->p);
4213 sha_mpint(&ssh->exhash, s->g);
a92dd380 4214 }
51470298 4215 sha_mpint(&ssh->exhash, s->e);
4216 sha_mpint(&ssh->exhash, s->f);
4217 sha_mpint(&ssh->exhash, s->K);
4218 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4219
27cd7fc2 4220 dh_cleanup(ssh->kex_ctx);
fabd1805 4221 ssh->kex_ctx = NULL;
3709bfe9 4222
7cca0d81 4223#if 0
765c4200 4224 debug(("Exchange hash is:\n"));
51470298 4225 dmemdump(s->exchange_hash, 20);
7cca0d81 4226#endif
4227
51470298 4228 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4229 if (!s->hkey ||
4230 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4231 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4232 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4233 crStop(0);
8d5de777 4234 }
e5574168 4235
4236 /*
7cca0d81 4237 * Authenticate remote host: verify host key. (We've already
4238 * checked the signature of the exchange hash.)
e5574168 4239 */
51470298 4240 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4241 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4242 verify_ssh_host_key(ssh->frontend,
4243 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4244 s->keystr, s->fingerprint);
4245 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4246 logevent("Host key fingerprint is:");
51470298 4247 logevent(s->fingerprint);
5e0d7cb8 4248 }
51470298 4249 sfree(s->fingerprint);
4250 sfree(s->keystr);
4251 ssh->hostkey->freekey(s->hkey);
d39f364a 4252
4253 /*
7cca0d81 4254 * Send SSH2_MSG_NEWKEYS.
d39f364a 4255 */
51470298 4256 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4257 ssh2_pkt_send(ssh);
d39f364a 4258
4259 /*
8406eaf9 4260 * Expect SSH2_MSG_NEWKEYS from server.
4261 */
4262 crWaitUntil(ispkt);
51470298 4263 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4264 bombout(("expected new-keys packet from server"));
7ffdbc1a 4265 crStop(0);
8406eaf9 4266 }
4267
4268 /*
d39f364a 4269 * Create and initialise session keys.
4270 */
371e569c 4271 if (ssh->cs_cipher_ctx)
4272 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4273 ssh->cscipher = s->cscipher_tobe;
371e569c 4274 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4275
371e569c 4276 if (ssh->sc_cipher_ctx)
4277 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4278 ssh->sccipher = s->sccipher_tobe;
371e569c 4279 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4280
4281 if (ssh->cs_mac_ctx)
4282 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4283 ssh->csmac = s->csmac_tobe;
e0e1a00d 4284 ssh->cs_mac_ctx = ssh->csmac->make_context();
4285
4286 if (ssh->sc_mac_ctx)
4287 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4288 ssh->scmac = s->scmac_tobe;
e0e1a00d 4289 ssh->sc_mac_ctx = ssh->scmac->make_context();
4290
5366aed8 4291 if (ssh->cs_comp_ctx)
4292 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4293 ssh->cscomp = s->cscomp_tobe;
5366aed8 4294 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4295
4296 if (ssh->sc_comp_ctx)
4297 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4298 ssh->sccomp = s->sccomp_tobe;
5366aed8 4299 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4300
d39f364a 4301 /*
5e0d7cb8 4302 * Set IVs after keys. Here we use the exchange hash from the
4303 * _first_ key exchange.
d39f364a 4304 */
51470298 4305 {
4306 unsigned char keyspace[40];
4307 if (s->first_kex)
4308 memcpy(ssh->v2_session_id, s->exchange_hash,
4309 sizeof(s->exchange_hash));
4310 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4311 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4312 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4313 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4314 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4315 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4316 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4317 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4318 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4319 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4320 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4321 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4322 }
57356d63 4323 logeventf(ssh, "Initialised %.200s client->server encryption",
4324 ssh->cscipher->text_name);
4325 logeventf(ssh, "Initialised %.200s server->client encryption",
4326 ssh->sccipher->text_name);
4327 if (ssh->cscomp->text_name)
4328 logeventf(ssh, "Initialised %s compression",
4329 ssh->cscomp->text_name);
4330 if (ssh->sccomp->text_name)
4331 logeventf(ssh, "Initialised %s decompression",
4332 ssh->sccomp->text_name);
d39f364a 4333
033b4cef 4334 /*
0db56f73 4335 * If this is the first key exchange phase, we must pass the
4336 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4337 * wants to see it but because it will need time to initialise
4338 * itself before it sees an actual packet. In subsequent key
4339 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4340 * it would only confuse the layer above.
4341 */
51470298 4342 if (!s->first_kex) {
32874aea 4343 crReturn(0);
0db56f73 4344 }
51470298 4345 s->first_kex = 0;
0db56f73 4346
4347 /*
7cca0d81 4348 * Now we're encrypting. Begin returning 1 to the protocol main
4349 * function so that other things can run on top of the
4350 * transport. If we ever see a KEXINIT, we must go back to the
4351 * start.
033b4cef 4352 */
51470298 4353 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4354 crReturn(1);
e96adf72 4355 }
5e0d7cb8 4356 logevent("Server initiated key re-exchange");
7cca0d81 4357 goto begin_key_exchange;
e5574168 4358
4359 crFinish(1);
4360}
4361
7cca0d81 4362/*
783415f8 4363 * Add data to an SSH2 channel output buffer.
4364 */
32874aea 4365static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4366 int len)
4367{
5471d09a 4368 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4369}
4370
4371/*
4372 * Attempt to send data on an SSH2 channel.
4373 */
5471d09a 4374static int ssh2_try_send(struct ssh_channel *c)
32874aea 4375{
51470298 4376 Ssh ssh = c->ssh;
4377
5471d09a 4378 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4379 int len;
4380 void *data;
4381 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4382 if ((unsigned)len > c->v.v2.remwindow)
4383 len = c->v.v2.remwindow;
4384 if ((unsigned)len > c->v.v2.remmaxpkt)
4385 len = c->v.v2.remmaxpkt;
51470298 4386 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4387 ssh2_pkt_adduint32(ssh, c->remoteid);
4388 ssh2_pkt_addstring_start(ssh);
4389 ssh2_pkt_addstring_data(ssh, data, len);
4390 ssh2_pkt_send(ssh);
5471d09a 4391 bufchain_consume(&c->v.v2.outbuffer, len);
4392 c->v.v2.remwindow -= len;
4393 }
4394
4395 /*
4396 * After having sent as much data as we can, return the amount
4397 * still buffered.
4398 */
4399 return bufchain_size(&c->v.v2.outbuffer);
4400}
4401
4402/*
4403 * Potentially enlarge the window on an SSH2 channel.
4404 */
4405static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4406{
51470298 4407 Ssh ssh = c->ssh;
4408
6b69f42e 4409 /*
4410 * Never send WINDOW_ADJUST for a channel that the remote side
4411 * already thinks it's closed; there's no point, since it won't
4412 * be sending any more data anyway.
4413 */
4414 if (c->closes != 0)
4415 return;
4416
5471d09a 4417 if (newwin > c->v.v2.locwindow) {
51470298 4418 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4419 ssh2_pkt_adduint32(ssh, c->remoteid);
4420 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4421 ssh2_pkt_send(ssh);
5471d09a 4422 c->v.v2.locwindow = newwin;
783415f8 4423 }
4424}
4425
4426/*
7cca0d81 4427 * Handle the SSH2 userauth and connection layers.
4428 */
51470298 4429static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4430{
51470298 4431 struct do_ssh2_authconn_state {
4432 enum {
4433 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4434 AUTH_PASSWORD,
4435 AUTH_KEYBOARD_INTERACTIVE
4436 } method;
4437 enum {
4438 AUTH_TYPE_NONE,
4439 AUTH_TYPE_PUBLICKEY,
4440 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4441 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4442 AUTH_TYPE_PASSWORD,
4443 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4444 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4445 } type;
4446 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4447 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4448 int kbd_inter_running;
4449 int we_are_in;
4450 int num_prompts, curr_prompt, echo;
4451 char username[100];
4452 int got_username;
4453 char pwprompt[200];
4454 char password[100];
4455 void *publickey_blob;
4456 int publickey_bloblen;
4457 unsigned char request[5], *response, *p;
4458 int responselen;
4459 int keyi, nkeys;
4460 int authed;
4461 char *pkblob, *alg, *commentp;
4462 int pklen, alglen, commentlen;
4463 int siglen, retlen, len;
4464 char *q, *agentreq, *ret;
4465 int try_send;
4466 };
4467 crState(do_ssh2_authconn_state);
4468
4469 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4470
7cca0d81 4471 /*
4472 * Request userauth protocol, and await a response to it.
4473 */
51470298 4474 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4475 ssh2_pkt_addstring(ssh, "ssh-userauth");
4476 ssh2_pkt_send(ssh);
7cca0d81 4477 crWaitUntilV(ispkt);
51470298 4478 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 4479 bombout(("Server refused user authentication protocol"));
7ffdbc1a 4480 crStopV;
8d5de777 4481 }
7cca0d81 4482
4483 /*
1408a877 4484 * We repeat this whole loop, including the username prompt,
4485 * until we manage a successful authentication. If the user
51470298 4486 * types the wrong _password_, they can be sent back to the
4487 * beginning to try another username, if this is configured on.
4488 * (If they specify a username in the config, they are never
4489 * asked, even if they do give a wrong password.)
1408a877 4490 *
4491 * I think this best serves the needs of
4492 *
4493 * - the people who have no configuration, no keys, and just
4494 * want to try repeated (username,password) pairs until they
4495 * type both correctly
4496 *
4497 * - people who have keys and configuration but occasionally
4498 * need to fall back to passwords
4499 *
4500 * - people with a key held in Pageant, who might not have
4501 * logged in to a particular machine before; so they want to
4502 * type a username, and then _either_ their key will be
4503 * accepted, _or_ they will type a password. If they mistype
4504 * the username they will want to be able to get back and
4505 * retype it!
7cca0d81 4506 */
51470298 4507 s->username[0] = '\0';
4508 s->got_username = FALSE;
1408a877 4509 do {
1408a877 4510 /*
4511 * Get a username.
4512 */
86916870 4513 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 4514 /*
4515 * We got a username last time round this loop, and
4516 * with change_username turned off we don't try to get
4517 * it again.
4518 */
86916870 4519 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 4520 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4521 if (!ssh_get_line("login as: ",
51470298 4522 s->username, sizeof(s->username), FALSE)) {
32874aea 4523 /*
4524 * get_line failed to get a username.
4525 * Terminate.
4526 */
4527 logevent("No username provided. Abandoning session.");
3bb2f322 4528 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4529 crStopV;
32874aea 4530 }
4531 } else {
51470298 4532 int ret; /* need not be saved across crReturn */
4533 c_write_str(ssh, "login as: ");
4534 ssh->send_ok = 1;
4535 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4536 do {
32874aea 4537 crWaitUntilV(!ispkt);
51470298 4538 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4539 } while (ret == 0);
4540 if (ret < 0)
4541 cleanup_exit(0);
4ca0c9d1 4542 c_write_str(ssh, "\r\n");
32874aea 4543 }
51470298 4544 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4545 } else {
57356d63 4546 char *stuff;
86916870 4547 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 4548 s->username[sizeof(s->username)-1] = '\0';
65a22376 4549 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 4550 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 4551 c_write_str(ssh, stuff);
57356d63 4552 sfree(stuff);
7cca0d81 4553 }
4554 }
51470298 4555 s->got_username = TRUE;
7cca0d81 4556
65a22376 4557 /*
1408a877 4558 * Send an authentication request using method "none": (a)
4559 * just in case it succeeds, and (b) so that we know what
4560 * authentication methods we can usefully try next.
65a22376 4561 */
51470298 4562 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4563
4564 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4565 ssh2_pkt_addstring(ssh, s->username);
4566 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4567 ssh2_pkt_addstring(ssh, "none"); /* method */
4568 ssh2_pkt_send(ssh);
4569 s->type = AUTH_TYPE_NONE;
4570 s->gotit = FALSE;
4571 s->we_are_in = FALSE;
4572
4573 s->tried_pubkey_config = FALSE;
4574 s->tried_agent = FALSE;
4575 s->tried_keyb_inter = FALSE;
4576 s->kbd_inter_running = FALSE;
86916870 4577 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 4578 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 4579 int keytype;
6c6d9ed9 4580 logeventf(ssh, "Reading private key file \"%.150s\"",
4581 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 4582 keytype = key_type(&ssh->cfg.keyfile);
51470298 4583 if (keytype == SSH_KEYTYPE_SSH2) {
4584 s->publickey_blob =
9a30e26b 4585 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
51470298 4586 &s->publickey_bloblen);
4587 } else {
57356d63 4588 char *msgbuf;
c2ad7d0d 4589 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 4590 key_type_to_str(keytype));
57356d63 4591 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 4592 " (%s)\r\n",
4593 filename_to_str(&ssh->cfg.keyfile),
57356d63 4594 key_type_to_str(keytype));
51470298 4595 c_write_str(ssh, msgbuf);
57356d63 4596 sfree(msgbuf);
51470298 4597 s->publickey_blob = NULL;
231ee168 4598 }
396778f1 4599 } else
51470298 4600 s->publickey_blob = NULL;
65a22376 4601
1408a877 4602 while (1) {
4603 /*
4604 * Wait for the result of the last authentication request.
4605 */
51470298 4606 if (!s->gotit)
1408a877 4607 crWaitUntilV(ispkt);
51470298 4608 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4609 char *banner;
4610 int size;
4611 /*
4612 * Don't show the banner if we're operating in
4613 * non-verbose non-interactive mode. (It's probably
4614 * a script, which means nobody will read the
4615 * banner _anyway_, and moreover the printing of
4616 * the banner will screw up processing on the
4617 * output of (say) plink.)
4618 */
4619 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4620 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4621 if (banner)
51470298 4622 c_write_untrusted(ssh, banner, size);
32874aea 4623 }
1408a877 4624 crWaitUntilV(ispkt);
4625 }
51470298 4626 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4627 logevent("Access granted");
51470298 4628 s->we_are_in = TRUE;
1408a877 4629 break;
4630 }
65a22376 4631
51470298 4632 if (s->kbd_inter_running &&
4633 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4634 /*
45068b27 4635 * This is either a further set-of-prompts packet
4636 * in keyboard-interactive authentication, or it's
4637 * the same one and we came back here with `gotit'
4638 * set. In the former case, we must reset the
4639 * curr_prompt variable.
b3186d64 4640 */
51470298 4641 if (!s->gotit)
4642 s->curr_prompt = 0;
4643 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 4644 bombout(("Strange packet received during authentication: type %d",
51470298 4645 ssh->pktin.type));
7ffdbc1a 4646 crStopV;
65a22376 4647 }
4648
51470298 4649 s->gotit = FALSE;
65a22376 4650
1408a877 4651 /*
4652 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4653 * we can look at the string in it and know what we can
4654 * helpfully try next.
4655 */
51470298 4656 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4657 char *methods;
4658 int methlen;
51470298 4659 ssh2_pkt_getstring(ssh, &methods, &methlen);
4660 s->kbd_inter_running = FALSE;
4661 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4662 /*
4663 * We have received an unequivocal Access
4664 * Denied. This can translate to a variety of
4665 * messages:
4666 *
4667 * - if we'd just tried "none" authentication,
4668 * it's not worth printing anything at all
4669 *
4670 * - if we'd just tried a public key _offer_,
4671 * the message should be "Server refused our
4672 * key" (or no message at all if the key
4673 * came from Pageant)
4674 *
4675 * - if we'd just tried anything else, the
4676 * message really should be "Access denied".
4677 *
4678 * Additionally, if we'd just tried password
4679 * authentication, we should break out of this
4680 * whole loop so as to go back to the username
4681 * prompt.
4682 */
51470298 4683 if (s->type == AUTH_TYPE_NONE) {
1408a877 4684 /* do nothing */
51470298 4685 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4686 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4687 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4688 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4689 logevent("Server refused public key");
51470298 4690 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4691 /* server declined keyboard-interactive; ignore */
1408a877 4692 } else {
51470298 4693 c_write_str(ssh, "Access denied\r\n");
1408a877 4694 logevent("Access denied");
51470298 4695 if (s->type == AUTH_TYPE_PASSWORD) {
4696 s->we_are_in = FALSE;
1408a877 4697 break;
4698 }
4699 }
4700 } else {
51470298 4701 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4702 logevent("Further authentication required");
4703 }
65a22376 4704
51470298 4705 s->can_pubkey =
32874aea 4706 in_commasep_string("publickey", methods, methlen);
51470298 4707 s->can_passwd =
32874aea 4708 in_commasep_string("password", methods, methlen);
86916870 4709 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 4710 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4711 }
65a22376 4712
51470298 4713 s->method = 0;
4714 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4715
0405e71f 4716 /*
4717 * Most password/passphrase prompts will be
4718 * non-echoing, so we set this to 0 by default.
4719 * Exception is that some keyboard-interactive prompts
4720 * can be echoing, in which case we'll set this to 1.
4721 */
51470298 4722 s->echo = 0;
0405e71f 4723
51470298 4724 if (!s->method && s->can_pubkey &&
4725 agent_exists() && !s->tried_agent) {
1983e559 4726 /*
4727 * Attempt public-key authentication using Pageant.
4728 */
1983e559 4729 void *r;
51470298 4730 s->authed = FALSE;
1983e559 4731
51470298 4732 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4733 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4734
51470298 4735 s->tried_agent = TRUE;
1983e559 4736
4737 logevent("Pageant is running. Requesting keys.");
4738
4739 /* Request the keys held by the agent. */
51470298 4740 PUT_32BIT(s->request, 1);
4741 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 4742 if (!agent_query(s->request, 5, &r, &s->responselen,
4743 ssh_agent_callback, ssh)) {
4744 do {
4745 crReturnV;
4746 if (ispkt) {
4747 bombout(("Unexpected data from server while"
4748 " waiting for agent response"));
4749 crStopV;
4750 }
4751 } while (ispkt || inlen > 0);
4752 r = ssh->agent_response;
4753 s->responselen = ssh->agent_response_len;
4754 }
51470298 4755 s->response = (unsigned char *) r;
4756 if (s->response && s->responselen >= 5 &&
4757 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4758 s->p = s->response + 5;
4759 s->nkeys = GET_32BIT(s->p);
4760 s->p += 4;
32874aea 4761 {
4762 char buf[64];
51470298 4763 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4764 logevent(buf);
4765 }
51470298 4766 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4767 void *vret;
1983e559 4768
32874aea 4769 {
4770 char buf[64];
51470298 4771 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4772 logevent(buf);
4773 }
51470298 4774 s->pklen = GET_32BIT(s->p);
4775 s->p += 4;
4776 if (s->publickey_blob &&
4777 s->pklen == s->publickey_bloblen &&
4778 !memcmp(s->p, s->publickey_blob,
4779 s->publickey_bloblen)) {
396778f1 4780 logevent("This key matches configured key file");
51470298 4781 s->tried_pubkey_config = 1;
396778f1 4782 }
d8baa528 4783 s->pkblob = (char *)s->p;
51470298 4784 s->p += s->pklen;
4785 s->alglen = GET_32BIT(s->pkblob);
4786 s->alg = s->pkblob + 4;
4787 s->commentlen = GET_32BIT(s->p);
4788 s->p += 4;
d8baa528 4789 s->commentp = (char *)s->p;
51470298 4790 s->p += s->commentlen;
4791 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4792 ssh2_pkt_addstring(ssh, s->username);
4793 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4794 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4795 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4796 ssh2_pkt_addstring_start(ssh);
4797 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4798 ssh2_pkt_addstring_start(ssh);
4799 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4800 ssh2_pkt_send(ssh);
1983e559 4801
4802 crWaitUntilV(ispkt);
51470298 4803 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4804 logevent("Key refused");
4805 continue;
4806 }
4807
32874aea 4808 if (flags & FLAG_VERBOSE) {
51470298 4809 c_write_str(ssh, "Authenticating with "
4810 "public key \"");
4811 c_write(ssh, s->commentp, s->commentlen);
4812 c_write_str(ssh, "\" from agent\r\n");
32874aea 4813 }
1983e559 4814
4815 /*
4816 * Server is willing to accept the key.
4817 * Construct a SIGN_REQUEST.
4818 */
51470298 4819 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4820 ssh2_pkt_addstring(ssh, s->username);
4821 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4822 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4823 ssh2_pkt_addbool(ssh, TRUE);
4824 ssh2_pkt_addstring_start(ssh);
4825 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4826 ssh2_pkt_addstring_start(ssh);
4827 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4828
4829 s->siglen = ssh->pktout.length - 5 + 4 + 20;
dda87a28 4830 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4831 s->siglen -= 4;
51470298 4832 s->len = 1; /* message type */
4833 s->len += 4 + s->pklen; /* key blob */
4834 s->len += 4 + s->siglen; /* data to sign */
4835 s->len += 4; /* flags */
3d88e64d 4836 s->agentreq = snewn(4 + s->len, char);
51470298 4837 PUT_32BIT(s->agentreq, s->len);
4838 s->q = s->agentreq + 4;
4839 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4840 PUT_32BIT(s->q, s->pklen);
4841 s->q += 4;
4842 memcpy(s->q, s->pkblob, s->pklen);
4843 s->q += s->pklen;
4844 PUT_32BIT(s->q, s->siglen);
4845 s->q += 4;
1983e559 4846 /* Now the data to be signed... */
dda87a28 4847 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4848 PUT_32BIT(s->q, 20);
4849 s->q += 4;
4850 }
51470298 4851 memcpy(s->q, ssh->v2_session_id, 20);
4852 s->q += 20;
4853 memcpy(s->q, ssh->pktout.data + 5,
4854 ssh->pktout.length - 5);
4855 s->q += ssh->pktout.length - 5;
1983e559 4856 /* And finally the (zero) flags word. */
51470298 4857 PUT_32BIT(s->q, 0);
839f10db 4858 if (!agent_query(s->agentreq, s->len + 4,
4859 &vret, &s->retlen,
4860 ssh_agent_callback, ssh)) {
4861 do {
4862 crReturnV;
4863 if (ispkt) {
4864 bombout(("Unexpected data from server"
4865 " while waiting for agent"
4866 " response"));
4867 crStopV;
4868 }
4869 } while (ispkt || inlen > 0);
4870 vret = ssh->agent_response;
4871 s->retlen = ssh->agent_response_len;
4872 }
51470298 4873 s->ret = vret;
4874 sfree(s->agentreq);
4875 if (s->ret) {
4876 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4877 logevent("Sending Pageant's response");
51470298 4878 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4879 s->ret + 9,
4880 GET_32BIT(s->ret + 5));
4881 ssh2_pkt_send(ssh);
4882 s->authed = TRUE;
1983e559 4883 break;
4884 } else {
32874aea 4885 logevent
4886 ("Pageant failed to answer challenge");
51470298 4887 sfree(s->ret);
1983e559 4888 }
4889 }
4890 }
51470298 4891 if (s->authed)
1983e559 4892 continue;
4893 }
4894 }
4895
51470298 4896 if (!s->method && s->can_pubkey && s->publickey_blob
4897 && !s->tried_pubkey_config) {
1408a877 4898 unsigned char *pub_blob;
4899 char *algorithm, *comment;
4900 int pub_blob_len;
65a22376 4901
51470298 4902 s->tried_pubkey_config = TRUE;
65a22376 4903
51470298 4904 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4905 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4906
65a22376 4907 /*
1408a877 4908 * Try the public key supplied in the configuration.
4909 *
4910 * First, offer the public blob to see if the server is
4911 * willing to accept it.
65a22376 4912 */
d8baa528 4913 pub_blob =
9a30e26b 4914 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 4915 &algorithm,
4916 &pub_blob_len);
1408a877 4917 if (pub_blob) {
51470298 4918 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4919 ssh2_pkt_addstring(ssh, s->username);
4920 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4921 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4922 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4923 ssh2_pkt_addstring(ssh, algorithm);
4924 ssh2_pkt_addstring_start(ssh);
d8baa528 4925 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4926 pub_blob_len);
51470298 4927 ssh2_pkt_send(ssh);
32874aea 4928 logevent("Offered public key"); /* FIXME */
1408a877 4929
4930 crWaitUntilV(ispkt);
51470298 4931 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4932 s->gotit = TRUE;
4933 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4934 continue; /* key refused; give up on it */
1408a877 4935 }
65a22376 4936
1408a877 4937 logevent("Offer of public key accepted");
65a22376 4938 /*
1408a877 4939 * Actually attempt a serious authentication using
4940 * the key.
65a22376 4941 */
9a30e26b 4942 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 4943 sprintf(s->pwprompt,
32874aea 4944 "Passphrase for key \"%.100s\": ",
4945 comment);
51470298 4946 s->need_pw = TRUE;
1408a877 4947 } else {
51470298 4948 s->need_pw = FALSE;
1408a877 4949 }
51470298 4950 c_write_str(ssh, "Authenticating with public key \"");
4951 c_write_str(ssh, comment);
4952 c_write_str(ssh, "\"\r\n");
4953 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4954 }
1408a877 4955 }
4956
51470298 4957 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4958 s->method = AUTH_KEYBOARD_INTERACTIVE;
4959 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4960 s->tried_keyb_inter = TRUE;
af659722 4961
51470298 4962 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4963 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4964
51470298 4965 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4966 ssh2_pkt_addstring(ssh, s->username);
4967 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4968 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4969 ssh2_pkt_addstring(ssh, ""); /* lang */
4970 ssh2_pkt_addstring(ssh, "");
4971 ssh2_pkt_send(ssh);
af659722 4972
4973 crWaitUntilV(ispkt);
51470298 4974 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4975 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4976 s->gotit = TRUE;
af659722 4977 logevent("Keyboard-interactive authentication refused");
51470298 4978 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4979 continue;
4980 }
4981
51470298 4982 s->kbd_inter_running = TRUE;
4983 s->curr_prompt = 0;
af659722 4984 }
4985
51470298 4986 if (s->kbd_inter_running) {
4987 s->method = AUTH_KEYBOARD_INTERACTIVE;
4988 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4989 s->tried_keyb_inter = TRUE;
af659722 4990
51470298 4991 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4992 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4993
51470298 4994 if (s->curr_prompt == 0) {
45068b27 4995 /*
4996 * We've got a fresh USERAUTH_INFO_REQUEST.
4997 * Display header data, and start going through
4998 * the prompts.
4999 */
5000 char *name, *inst, *lang;
5001 int name_len, inst_len, lang_len;
5002
51470298 5003 ssh2_pkt_getstring(ssh, &name, &name_len);
5004 ssh2_pkt_getstring(ssh, &inst, &inst_len);
5005 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 5006 if (name_len > 0) {
51470298 5007 c_write_untrusted(ssh, name, name_len);
5008 c_write_str(ssh, "\r\n");
45068b27 5009 }
5010 if (inst_len > 0) {
51470298 5011 c_write_untrusted(ssh, inst, inst_len);
5012 c_write_str(ssh, "\r\n");
45068b27 5013 }
51470298 5014 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 5015 }
af659722 5016
45068b27 5017 /*
5018 * If there are prompts remaining in the packet,
5019 * display one and get a response.
5020 */
51470298 5021 if (s->curr_prompt < s->num_prompts) {
45068b27 5022 char *prompt;
5023 int prompt_len;
af659722 5024
51470298 5025 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 5026 if (prompt_len > 0) {
51470298 5027 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
5028 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
5029 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 5030 } else {
51470298 5031 strcpy(s->pwprompt,
45068b27 5032 "<server failed to send prompt>: ");
5033 }
51470298 5034 s->echo = ssh2_pkt_getbool(ssh);
5035 s->need_pw = TRUE;
45068b27 5036 } else
51470298 5037 s->need_pw = FALSE;
af659722 5038 }
5039
51470298 5040 if (!s->method && s->can_passwd) {
5041 s->method = AUTH_PASSWORD;
5042 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5043 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5044 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5045 ssh->savedhost);
5046 s->need_pw = TRUE;
1408a877 5047 }
5048
51470298 5049 if (s->need_pw) {
fa17a66e 5050 if (ssh_get_line) {
51470298 5051 if (!ssh_get_line(s->pwprompt, s->password,
5052 sizeof(s->password), TRUE)) {
1408a877 5053 /*
fa17a66e 5054 * get_line failed to get a password (for
5055 * example because one was supplied on the
5056 * command line which has already failed to
5057 * work). Terminate.
1408a877 5058 */
51470298 5059 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5060 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5061 ssh2_pkt_addstring(ssh, "No more passwords available"
5062 " to try");
5063 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5064 ssh2_pkt_send(ssh);
247308b5 5065 logevent("Unable to authenticate");
a8327734 5066 connection_fatal(ssh->frontend,
5067 "Unable to authenticate");
3bb2f322 5068 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5069 crStopV;
1408a877 5070 }
5071 } else {
51470298 5072 int ret; /* need not be saved across crReturn */
5073 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5074 ssh->send_ok = 1;
1408a877 5075
51470298 5076 setup_userpass_input(ssh, s->password,
5077 sizeof(s->password), s->echo);
0405e71f 5078 do {
1408a877 5079 crWaitUntilV(!ispkt);
51470298 5080 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5081 } while (ret == 0);
5082 if (ret < 0)
5083 cleanup_exit(0);
51470298 5084 c_write_str(ssh, "\r\n");
65a22376 5085 }
65a22376 5086 }
65a22376 5087
51470298 5088 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 5089 /*
5090 * We have our passphrase. Now try the actual authentication.
5091 */
5092 struct ssh2_userkey *key;
65a22376 5093
9a30e26b 5094 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
1408a877 5095 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5096 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 5097 c_write_str(ssh, "Wrong passphrase\r\n");
5098 s->tried_pubkey_config = FALSE;
1408a877 5099 } else {
51470298 5100 c_write_str(ssh, "Unable to load private key\r\n");
5101 s->tried_pubkey_config = TRUE;
1408a877 5102 }
5103 /* Send a spurious AUTH_NONE to return to the top. */
51470298 5104 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5105 ssh2_pkt_addstring(ssh, s->username);
5106 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5107 ssh2_pkt_addstring(ssh, "none"); /* method */
5108 ssh2_pkt_send(ssh);
5109 s->type = AUTH_TYPE_NONE;
1408a877 5110 } else {
1dd353b5 5111 unsigned char *pkblob, *sigblob, *sigdata;
5112 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 5113 int p;
65a22376 5114
1408a877 5115 /*
5116 * We have loaded the private key and the server
5117 * has announced that it's willing to accept it.
5118 * Hallelujah. Generate a signature and send it.
5119 */
51470298 5120 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5121 ssh2_pkt_addstring(ssh, s->username);
5122 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5123 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5124 ssh2_pkt_addbool(ssh, TRUE);
5125 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 5126 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 5127 ssh2_pkt_addstring_start(ssh);
d8baa528 5128 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
1408a877 5129
5130 /*
5131 * The data to be signed is:
5132 *
5133 * string session-id
5134 *
5135 * followed by everything so far placed in the
5136 * outgoing packet.
5137 */
51470298 5138 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
dda87a28 5139 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5140 sigdata_len -= 4;
92d60585 5141 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 5142 p = 0;
5143 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5144 PUT_32BIT(sigdata+p, 20);
5145 p += 4;
5146 }
5147 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5148 memcpy(sigdata+p, ssh->pktout.data + 5,
51470298 5149 ssh->pktout.length - 5);
dda87a28 5150 p += ssh->pktout.length - 5;
5151 assert(p == sigdata_len);
d8baa528 5152 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 5153 sigdata_len, &sigblob_len);
51470298 5154 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 5155 sigblob, sigblob_len);
5156 sfree(pkblob);
5157 sfree(sigblob);
1408a877 5158 sfree(sigdata);
5159
51470298 5160 ssh2_pkt_send(ssh);
5161 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 5162 }
51470298 5163 } else if (s->method == AUTH_PASSWORD) {
65a22376 5164 /*
1408a877 5165 * We send the password packet lumped tightly together with
5166 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5167 * string long enough to make the total length of the two
5168 * packets constant. This should ensure that a passive
5169 * listener doing traffic analyis can't work out the length
5170 * of the password.
5171 *
5172 * For this to work, we need an assumption about the
5173 * maximum length of the password packet. I think 256 is
5174 * pretty conservative. Anyone using a password longer than
5175 * that probably doesn't have much to worry about from
5176 * people who find out how long their password is!
65a22376 5177 */
51470298 5178 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5179 ssh2_pkt_addstring(ssh, s->username);
5180 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5181 ssh2_pkt_addstring(ssh, "password");
5182 ssh2_pkt_addbool(ssh, FALSE);
5183 ssh2_pkt_addstring(ssh, s->password);
1409c1b3 5184 memset(s->password, 0, sizeof(s->password));
51470298 5185 ssh2_pkt_defer(ssh);
65a22376 5186 /*
1408a877 5187 * We'll include a string that's an exact multiple of the
5188 * cipher block size. If the cipher is NULL for some
5189 * reason, we don't do this trick at all because we gain
5190 * nothing by it.
65a22376 5191 */
51470298 5192 if (ssh->cscipher) {
32874aea 5193 int stringlen, i;
5194
51470298 5195 stringlen = (256 - ssh->deferred_len);
5196 stringlen += ssh->cscipher->blksize - 1;
5197 stringlen -= (stringlen % ssh->cscipher->blksize);
5198 if (ssh->cscomp) {
32874aea 5199 /*
5200 * Temporarily disable actual compression,
5201 * so we can guarantee to get this string
5202 * exactly the length we want it. The
5203 * compression-disabling routine should
5204 * return an integer indicating how many
5205 * bytes we should adjust our string length
5206 * by.
5207 */
5366aed8 5208 stringlen -=
5209 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 5210 }
51470298 5211 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5212 ssh2_pkt_addstring_start(ssh);
6e9e9520 5213 for (i = 0; i < stringlen; i++) {
32874aea 5214 char c = (char) random_byte();
51470298 5215 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 5216 }
51470298 5217 ssh2_pkt_defer(ssh);
65a22376 5218 }
51470298 5219 ssh_pkt_defersend(ssh);
0d43337a 5220 logevent("Sent password");
51470298 5221 s->type = AUTH_TYPE_PASSWORD;
5222 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5223 if (s->curr_prompt == 0) {
5224 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5225 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 5226 }
51470298 5227 if (s->need_pw) { /* only add pw if we just got one! */
5228 ssh2_pkt_addstring(ssh, s->password);
5229 memset(s->password, 0, sizeof(s->password));
5230 s->curr_prompt++;
45068b27 5231 }
51470298 5232 if (s->curr_prompt >= s->num_prompts) {
5233 ssh2_pkt_send(ssh);
45068b27 5234 } else {
5235 /*
5236 * If there are prompts remaining, we set
5237 * `gotit' so that we won't attempt to get
5238 * another packet. Then we go back round the
5239 * loop and will end up retrieving another
5240 * prompt out of the existing packet. Funky or
5241 * what?
5242 */
51470298 5243 s->gotit = TRUE;
45068b27 5244 }
51470298 5245 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5246 } else {
51470298 5247 c_write_str(ssh, "No supported authentication methods"
5248 " left to try!\r\n");
5249 logevent("No supported authentications offered."
5250 " Disconnecting");
5251 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5252 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5253 ssh2_pkt_addstring(ssh, "No supported authentication"
5254 " methods available");
5255 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5256 ssh2_pkt_send(ssh);
3bb2f322 5257 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5258 crStopV;
65a22376 5259 }
65a22376 5260 }
51470298 5261 } while (!s->we_are_in);
7cca0d81 5262
5263 /*
5264 * Now we're authenticated for the connection protocol. The
5265 * connection protocol will automatically have started at this
5266 * point; there's no need to send SERVICE_REQUEST.
5267 */
5268
5269 /*
5270 * So now create a channel with a session in it.
5271 */
51470298 5272 ssh->channels = newtree234(ssh_channelcmp);
3d88e64d 5273 ssh->mainchan = snew(struct ssh_channel);
51470298 5274 ssh->mainchan->ssh = ssh;
5275 ssh->mainchan->localid = alloc_channel_id(ssh);
5276 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5277 ssh2_pkt_addstring(ssh, "session");
5278 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5279 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5280 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5281 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5282 ssh2_pkt_send(ssh);
7cca0d81 5283 crWaitUntilV(ispkt);
51470298 5284 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6b5cf8b4 5285 bombout(("Server refused to open a session"));
7ffdbc1a 5286 crStopV;
32874aea 5287 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5288 }
51470298 5289 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
6b5cf8b4 5290 bombout(("Server's channel confirmation cited wrong channel"));
7ffdbc1a 5291 crStopV;
7cca0d81 5292 }
51470298 5293 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5294 ssh->mainchan->type = CHAN_MAINSESSION;
5295 ssh->mainchan->closes = 0;
5296 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5297 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5298 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5299 add234(ssh->channels, ssh->mainchan);
7cca0d81 5300 logevent("Opened channel for session");
5301
5302 /*
783415f8 5303 * Potentially enable X11 forwarding.
5304 */
86916870 5305 if (ssh->cfg.x11_forward) {
32874aea 5306 char proto[20], data[64];
5307 logevent("Requesting X11 forwarding");
302121de 5308 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5309 data, sizeof(data), ssh->cfg.x11_auth);
5310 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 5311 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5312 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5313 ssh2_pkt_addstring(ssh, "x11-req");
5314 ssh2_pkt_addbool(ssh, 1); /* want reply */
5315 ssh2_pkt_addbool(ssh, 0); /* many connections */
5316 ssh2_pkt_addstring(ssh, proto);
5317 ssh2_pkt_addstring(ssh, data);
86916870 5318 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
51470298 5319 ssh2_pkt_send(ssh);
32874aea 5320
5321 do {
5322 crWaitUntilV(ispkt);
51470298 5323 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5324 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5325 struct ssh_channel *c;
51470298 5326 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5327 if (!c)
5328 continue; /* nonexistent channel */
51470298 5329 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5330 }
51470298 5331 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5332
51470298 5333 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5334 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5335 bombout(("Unexpected response to X11 forwarding request:"
51470298 5336 " packet type %d", ssh->pktin.type));
7ffdbc1a 5337 crStopV;
32874aea 5338 }
5339 logevent("X11 forwarding refused");
5340 } else {
5341 logevent("X11 forwarding enabled");
51470298 5342 ssh->X11_fwd_enabled = TRUE;
32874aea 5343 }
783415f8 5344 }
5345
5346 /*
bc240b21 5347 * Enable port forwardings.
5348 */
5349 {
bc240b21 5350 char type;
5351 int n;
a4fc0d74 5352 int sport,dport,sserv,dserv;
6ee9b735 5353 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5354
51470298 5355 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5356 /* Add port forwardings. */
86916870 5357 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5358 while (*ssh->portfwd_strptr) {
5359 type = *ssh->portfwd_strptr++;
6ee9b735 5360 saddr[0] = '\0';
bc240b21 5361 n = 0;
6ee9b735 5362 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5363 if (*ssh->portfwd_strptr == ':') {
5364 /*
5365 * We've seen a colon in the middle of the
5366 * source port number. This means that
5367 * everything we've seen until now is the
5368 * source _address_, so we'll move it into
5369 * saddr and start sports from the beginning
5370 * again.
5371 */
5372 ssh->portfwd_strptr++;
5373 sports[n] = '\0';
5374 strcpy(saddr, sports);
5375 n = 0;
5376 }
5377 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5378 }
bc240b21 5379 sports[n] = 0;
820ebe3b 5380 if (type != 'D') {
5381 if (*ssh->portfwd_strptr == '\t')
5382 ssh->portfwd_strptr++;
5383 n = 0;
5384 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5385 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5386 }
5387 host[n] = 0;
5388 if (*ssh->portfwd_strptr == ':')
5389 ssh->portfwd_strptr++;
5390 n = 0;
5391 while (*ssh->portfwd_strptr) {
5392 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5393 }
5394 dports[n] = 0;
51470298 5395 ssh->portfwd_strptr++;
820ebe3b 5396 dport = atoi(dports);
5397 dserv = 0;
5398 if (dport == 0) {
5399 dserv = 1;
5400 dport = net_service_lookup(dports);
5401 if (!dport) {
5402 logeventf(ssh, "Service lookup failed for destination"
5403 " port \"%s\"", dports);
5404 }
a4fc0d74 5405 }
820ebe3b 5406 } else {
5407 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 5408 dport = dserv = -1;
a4fc0d74 5409 }
bc240b21 5410 sport = atoi(sports);
a4fc0d74 5411 sserv = 0;
5412 if (sport == 0) {
5413 sserv = 1;
68a49acb 5414 sport = net_service_lookup(sports);
5415 if (!sport) {
57356d63 5416 logeventf(ssh, "Service lookup failed for source"
5417 " port \"%s\"", sports);
a4fc0d74 5418 }
5419 }
bc240b21 5420 if (sport && dport) {
5421 if (type == 'L') {
6ee9b735 5422 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 5423 sport, ssh, &ssh->cfg);
6ee9b735 5424 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5425 " forwarding to %s:%.*s%.*s%d%.*s",
5426 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5427 (int)(*saddr?1:0), ":",
57356d63 5428 (int)(sserv ? strlen(sports) : 0), sports,
5429 sserv, "(", sport, sserv, ")",
5430 host,
5431 (int)(dserv ? strlen(dports) : 0), dports,
5432 dserv, "(", dport, dserv, ")");
820ebe3b 5433 } else if (type == 'D') {
5434 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5435 sport, ssh, &ssh->cfg);
5436 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5437 " doing SOCKS dynamic forwarding",
5438 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5439 (int)(*saddr?1:0), ":",
5440 (int)(sserv ? strlen(sports) : 0), sports,
5441 sserv, "(", sport, sserv, ")");
bc240b21 5442 } else {
5443 struct ssh_rportfwd *pf;
3d88e64d 5444 pf = snew(struct ssh_rportfwd);
bc240b21 5445 strcpy(pf->dhost, host);
5446 pf->dport = dport;
5447 pf->sport = sport;
51470298 5448 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5449 logeventf(ssh, "Duplicate remote port forwarding"
5450 " to %s:%d", host, dport);
bc240b21 5451 sfree(pf);
5452 } else {
6ee9b735 5453 logeventf(ssh, "Requesting remote port "
5454 "%.*s%.*s%.*s%.*s%d%.*s"
57356d63 5455 " forward to %s:%.*s%.*s%d%.*s",
6ee9b735 5456 (int)(*saddr?strlen(saddr):0),
5457 *saddr?saddr:NULL,
5458 (int)(*saddr?1:0), ":",
57356d63 5459 (int)(sserv ? strlen(sports) : 0), sports,
5460 sserv, "(", sport, sserv, ")",
5461 host,
5462 (int)(dserv ? strlen(dports) : 0), dports,
5463 dserv, "(", dport, dserv, ")");
51470298 5464 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5465 ssh2_pkt_addstring(ssh, "tcpip-forward");
5466 ssh2_pkt_addbool(ssh, 1);/* want reply */
6ee9b735 5467 if (*saddr)
5468 ssh2_pkt_addstring(ssh, saddr);
86916870 5469 if (ssh->cfg.rport_acceptall)
51470298 5470 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5471 else
51470298 5472 ssh2_pkt_addstring(ssh, "127.0.0.1");
5473 ssh2_pkt_adduint32(ssh, sport);
5474 ssh2_pkt_send(ssh);
bc240b21 5475
5476 do {
5477 crWaitUntilV(ispkt);
51470298 5478 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5479 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5480 struct ssh_channel *c;
51470298 5481 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5482 if (!c)
5483 continue;/* nonexistent channel */
51470298 5484 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5485 }
51470298 5486 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5487
51470298 5488 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5489 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 5490 bombout(("Unexpected response to port "
c9886e66 5491 "forwarding request: packet type %d",
51470298 5492 ssh->pktin.type));
7ffdbc1a 5493 crStopV;
bc240b21 5494 }
5495 logevent("Server refused this port forwarding");
5496 } else {
5497 logevent("Remote port forwarding enabled");
5498 }
5499 }
5500 }
5501 }
5502 }
5503 }
5504
5505 /*
36c2a3e9 5506 * Potentially enable agent forwarding.
5507 */
86916870 5508 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 5509 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5510 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5511 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5512 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5513 ssh2_pkt_addbool(ssh, 1); /* want reply */
5514 ssh2_pkt_send(ssh);
32874aea 5515
5516 do {
5517 crWaitUntilV(ispkt);
51470298 5518 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5519 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5520 struct ssh_channel *c;
51470298 5521 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5522 if (!c)
5523 continue; /* nonexistent channel */
51470298 5524 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5525 }
51470298 5526 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5527
51470298 5528 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5529 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5530 bombout(("Unexpected response to agent forwarding request:"
51470298 5531 " packet type %d", ssh->pktin.type));
7ffdbc1a 5532 crStopV;
32874aea 5533 }
5534 logevent("Agent forwarding refused");
5535 } else {
5536 logevent("Agent forwarding enabled");
51470298 5537 ssh->agentfwd_enabled = TRUE;
32874aea 5538 }
36c2a3e9 5539 }
5540
5541 /*
7cca0d81 5542 * Now allocate a pty for the session.
5543 */
86916870 5544 if (!ssh->cfg.nopty) {
51470298 5545 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5546 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5547 ssh2_pkt_addstring(ssh, "pty-req");
5548 ssh2_pkt_addbool(ssh, 1); /* want reply */
86916870 5549 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
51470298 5550 ssh2_pkt_adduint32(ssh, ssh->term_width);
5551 ssh2_pkt_adduint32(ssh, ssh->term_height);
5552 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5553 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5554 ssh2_pkt_addstring_start(ssh);
5555 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5556 ssh2_pkt_send(ssh);
5557 ssh->state = SSH_STATE_INTERMED;
32874aea 5558
5559 do {
5560 crWaitUntilV(ispkt);
51470298 5561 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5562 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5563 struct ssh_channel *c;
51470298 5564 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5565 if (!c)
5566 continue; /* nonexistent channel */
51470298 5567 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5568 }
51470298 5569 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5570
51470298 5571 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5572 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5573 bombout(("Unexpected response to pty request:"
51470298 5574 " packet type %d", ssh->pktin.type));
7ffdbc1a 5575 crStopV;
32874aea 5576 }
51470298 5577 c_write_str(ssh, "Server refused to allocate pty\r\n");
5578 ssh->editing = ssh->echoing = 1;
32874aea 5579 } else {
5580 logevent("Allocated pty");
5581 }
0965bee0 5582 } else {
51470298 5583 ssh->editing = ssh->echoing = 1;
7cca0d81 5584 }
5585
5586 /*
fd5e5847 5587 * Start a shell or a remote command. We may have to attempt
5588 * this twice if the config data has provided a second choice
5589 * of command.
7cca0d81 5590 */
fd5e5847 5591 while (1) {
5592 int subsys;
5593 char *cmd;
5594
51470298 5595 if (ssh->fallback_cmd) {
86916870 5596 subsys = ssh->cfg.ssh_subsys2;
5597 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 5598 } else {
86916870 5599 subsys = ssh->cfg.ssh_subsys;
5600 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 5601 }
5602
51470298 5603 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5604 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5605 if (subsys) {
51470298 5606 ssh2_pkt_addstring(ssh, "subsystem");
5607 ssh2_pkt_addbool(ssh, 1); /* want reply */
5608 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5609 } else if (*cmd) {
51470298 5610 ssh2_pkt_addstring(ssh, "exec");
5611 ssh2_pkt_addbool(ssh, 1); /* want reply */
5612 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5613 } else {
51470298 5614 ssh2_pkt_addstring(ssh, "shell");
5615 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5616 }
51470298 5617 ssh2_pkt_send(ssh);
fd5e5847 5618 do {
5619 crWaitUntilV(ispkt);
51470298 5620 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5621 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5622 struct ssh_channel *c;
51470298 5623 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5624 if (!c)
5625 continue; /* nonexistent channel */
51470298 5626 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5627 }
51470298 5628 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5629 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5630 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5631 bombout(("Unexpected response to shell/command request:"
51470298 5632 " packet type %d", ssh->pktin.type));
7ffdbc1a 5633 crStopV;
fd5e5847 5634 }
5635 /*
5636 * We failed to start the command. If this is the
5637 * fallback command, we really are finished; if it's
5638 * not, and if the fallback command exists, try falling
5639 * back to it before complaining.
5640 */
86916870 5641 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5642 logevent("Primary command failed; attempting fallback");
51470298 5643 ssh->fallback_cmd = TRUE;
fd5e5847 5644 continue;
5645 }
6b5cf8b4 5646 bombout(("Server refused to start a shell/command"));
7ffdbc1a 5647 crStopV;
fd5e5847 5648 } else {
5649 logevent("Started a shell/command");
32874aea 5650 }
fd5e5847 5651 break;
7cca0d81 5652 }
5653
51470298 5654 ssh->state = SSH_STATE_SESSION;
5655 if (ssh->size_needed)
5656 ssh_size(ssh, ssh->term_width, ssh->term_height);
5657 if (ssh->eof_needed)
5658 ssh_special(ssh, TS_EOF);
6e48c3fe 5659
7cca0d81 5660 /*
5661 * Transfer data!
5662 */
b9d7bcad 5663 if (ssh->ldisc)
5664 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5665 ssh->send_ok = 1;
7cca0d81 5666 while (1) {
e5574168 5667 crReturnV;
51470298 5668 s->try_send = FALSE;
7cca0d81 5669 if (ispkt) {
51470298 5670 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5671 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5672 char *data;
5673 int length;
51470298 5674 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5675 struct ssh_channel *c;
51470298 5676 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5677 if (!c)
5678 continue; /* nonexistent channel */
51470298 5679 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5680 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5681 continue; /* extended but not stderr */
51470298 5682 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5683 if (data) {
7ffdbc1a 5684 int bufsize = 0;
5471d09a 5685 c->v.v2.locwindow -= length;
32874aea 5686 switch (c->type) {
5687 case CHAN_MAINSESSION:
5471d09a 5688 bufsize =
51470298 5689 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5690 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5691 data, length);
32874aea 5692 break;
5693 case CHAN_X11:
5471d09a 5694 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5695 break;
d74d141c 5696 case CHAN_SOCKDATA:
5471d09a 5697 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5698 break;
36c2a3e9 5699 case CHAN_AGENT:
32874aea 5700 while (length > 0) {
5701 if (c->u.a.lensofar < 4) {
5702 int l = min(4 - c->u.a.lensofar, length);
5703 memcpy(c->u.a.msglen + c->u.a.lensofar,
5704 data, l);
5705 data += l;
5706 length -= l;
5707 c->u.a.lensofar += l;
5708 }
5709 if (c->u.a.lensofar == 4) {
5710 c->u.a.totallen =
5711 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 5712 c->u.a.message = snewn(c->u.a.totallen,
5713 unsigned char);
32874aea 5714 memcpy(c->u.a.message, c->u.a.msglen, 4);
5715 }
5716 if (c->u.a.lensofar >= 4 && length > 0) {
5717 int l =
5718 min(c->u.a.totallen - c->u.a.lensofar,
5719 length);
5720 memcpy(c->u.a.message + c->u.a.lensofar,
5721 data, l);
5722 data += l;
5723 length -= l;
5724 c->u.a.lensofar += l;
5725 }
5726 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 5727 void *reply;
32874aea 5728 int replylen;
839f10db 5729 if (agent_query(c->u.a.message,
5730 c->u.a.totallen,
5731 &reply, &replylen,
5732 ssh_agentf_callback, c))
5733 ssh_agentf_callback(c, reply, replylen);
32874aea 5734 sfree(c->u.a.message);
5735 c->u.a.lensofar = 0;
5736 }
5737 }
5471d09a 5738 bufsize = 0;
32874aea 5739 break;
5740 }
5741 /*
5471d09a 5742 * If we are not buffering too much data,
5743 * enlarge the window again at the remote side.
32874aea 5744 */
5471d09a 5745 if (bufsize < OUR_V2_WINSIZE)
5746 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5747 }
51470298 5748 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5749 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5750 struct ssh_channel *c;
5751
51470298 5752 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5753 if (!c)
5754 continue; /* nonexistent channel */
5755
5756 if (c->type == CHAN_X11) {
5757 /*
5758 * Remote EOF on an X11 channel means we should
5759 * wrap up and close the channel ourselves.
5760 */
5761 x11_close(c->u.x11.s);
5762 sshfwd_close(c);
5763 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5764 sshfwd_close(c);
d74d141c 5765 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5766 pfd_close(c->u.pfd.s);
5767 sshfwd_close(c);
36c2a3e9 5768 }
51470298 5769 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5770 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5771 struct ssh_channel *c;
5772
51470298 5773 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5774 if (!c || ((int)c->remoteid) == -1) {
6b5cf8b4 5775 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 5776 c ? "half-open" : "nonexistent", i));
7ffdbc1a 5777 crStopV;
d0d844c1 5778 }
32874aea 5779 /* Do pre-close processing on the channel. */
5780 switch (c->type) {
5781 case CHAN_MAINSESSION:
5782 break; /* nothing to see here, move along */
5783 case CHAN_X11:
92f157bd 5784 if (c->u.x11.s != NULL)
5785 x11_close(c->u.x11.s);
5786 sshfwd_close(c);
32874aea 5787 break;
5788 case CHAN_AGENT:
92f157bd 5789 sshfwd_close(c);
32874aea 5790 break;
d74d141c 5791 case CHAN_SOCKDATA:
92f157bd 5792 if (c->u.pfd.s != NULL)
5793 pfd_close(c->u.pfd.s);
5794 sshfwd_close(c);
bc240b21 5795 break;
32874aea 5796 }
92f157bd 5797 if (c->closes == 0) {
51470298 5798 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5799 ssh2_pkt_adduint32(ssh, c->remoteid);
5800 ssh2_pkt_send(ssh);
92f157bd 5801 }
51470298 5802 del234(ssh->channels, c);
5471d09a 5803 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5804 sfree(c);
5805
5806 /*
5807 * See if that was the last channel left open.
5808 */
51470298 5809 if (count234(ssh->channels) == 0) {
3bb2f322 5810 logevent("All channels closed. Disconnecting");
ca2914d1 5811#if 0
5812 /*
5813 * We used to send SSH_MSG_DISCONNECT here,
5814 * because I'd believed that _every_ conforming
5815 * SSH2 connection had to end with a disconnect
5816 * being sent by at least one side; apparently
5817 * I was wrong and it's perfectly OK to
5818 * unceremoniously slam the connection shut
5819 * when you're done, and indeed OpenSSH feels
5820 * this is more polite than sending a
5821 * DISCONNECT. So now we don't.
5822 */
51470298 5823 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5824 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5825 ssh2_pkt_addstring(ssh, "All open channels closed");
5826 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5827 ssh2_pkt_send(ssh);
ca2914d1 5828#endif
3bb2f322 5829 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5830 crStopV;
32874aea 5831 }
5832 continue; /* remote sends close; ignore (FIXME) */
51470298 5833 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5834 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5835 struct ssh_channel *c;
51470298 5836 c = find234(ssh->channels, &i, ssh_channelfind);
a6253970 5837 if (!c || c->closes)
5838 continue; /* nonexistent or closing channel */
51470298 5839 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5840 s->try_send = TRUE;
5841 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5842 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5843 struct ssh_channel *c;
51470298 5844 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5845 if (!c)
5846 continue; /* nonexistent channel */
5847 if (c->type != CHAN_SOCKDATA_DORMANT)
5848 continue; /* dunno why they're confirming this */
51470298 5849 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5850 c->type = CHAN_SOCKDATA;
51470298 5851 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5852 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5853 if (c->u.pfd.s)
5854 pfd_confirm(c->u.pfd.s);
5855 if (c->closes) {
5856 /*
5857 * We have a pending close on this channel,
5858 * which we decided on before the server acked
5859 * the channel open. So now we know the
5860 * remoteid, we can close it again.
5861 */
51470298 5862 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5863 ssh2_pkt_adduint32(ssh, c->remoteid);
5864 ssh2_pkt_send(ssh);
4ed34d25 5865 }
51470298 5866 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5867 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5868 struct ssh_channel *c;
51470298 5869 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5870 if (!c)
5871 continue; /* nonexistent channel */
5872 if (c->type != CHAN_SOCKDATA_DORMANT)
5873 continue; /* dunno why they're failing this */
5874
5875 logevent("Forwarded connection refused by server");
5876
5877 pfd_close(c->u.pfd.s);
5878
51470298 5879 del234(ssh->channels, c);
724cface 5880 sfree(c);
51470298 5881 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5882 unsigned localid;
5883 char *type;
5884 int typelen, want_reply;
5885 struct ssh_channel *c;
5886
51470298 5887 localid = ssh2_pkt_getuint32(ssh);
5888 ssh2_pkt_getstring(ssh, &type, &typelen);
5889 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5890
5891 /*
5892 * First, check that the channel exists. Otherwise,
5893 * we can instantly disconnect with a rude message.
5894 */
51470298 5895 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5896 if (!c) {
5897 char buf[80];
5898 sprintf(buf, "Received channel request for nonexistent"
5899 " channel %d", localid);
5900 logevent(buf);
51470298 5901 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5902 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5903 ssh2_pkt_addstring(ssh, buf);
5904 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5905 ssh2_pkt_send(ssh);
6b5cf8b4 5906 connection_fatal(ssh->frontend, "%s", buf);
3bb2f322 5907 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5908 crStopV;
ebb0a590 5909 }
5910
5911 /*
d8d6c7e5 5912 * Having got the channel number, we now look at
5913 * the request type string to see if it's something
5914 * we recognise.
ebb0a590 5915 */
d8d6c7e5 5916 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5917 c == ssh->mainchan) {
d8d6c7e5 5918 /* We recognise "exit-status" on the primary channel. */
5919 char buf[100];
51470298 5920 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5921 sprintf(buf, "Server sent command exit status %d",
51470298 5922 ssh->exitcode);
d8d6c7e5 5923 logevent(buf);
5924 if (want_reply) {
51470298 5925 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5926 ssh2_pkt_adduint32(ssh, c->remoteid);
5927 ssh2_pkt_send(ssh);
d8d6c7e5 5928 }
5929 } else {
5930 /*
5931 * This is a channel request we don't know
5932 * about, so we now either ignore the request
5933 * or respond with CHANNEL_FAILURE, depending
5934 * on want_reply.
5935 */
5936 if (want_reply) {
51470298 5937 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5938 ssh2_pkt_adduint32(ssh, c->remoteid);
5939 ssh2_pkt_send(ssh);
d8d6c7e5 5940 }
ebb0a590 5941 }
51470298 5942 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5943 char *type;
5944 int typelen, want_reply;
5945
51470298 5946 ssh2_pkt_getstring(ssh, &type, &typelen);
5947 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5948
5949 /*
5950 * We currently don't support any global requests
5951 * at all, so we either ignore the request or
5952 * respond with REQUEST_FAILURE, depending on
5953 * want_reply.
5954 */
5955 if (want_reply) {
51470298 5956 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5957 ssh2_pkt_send(ssh);
697d4856 5958 }
51470298 5959 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5960 char *type;
5961 int typelen;
b3ebaa28 5962 char *peeraddr;
5963 int peeraddrlen;
2e5b14c0 5964 int peerport;
32874aea 5965 char *error = NULL;
5966 struct ssh_channel *c;
bc240b21 5967 unsigned remid, winsize, pktsize;
51470298 5968 ssh2_pkt_getstring(ssh, &type, &typelen);
3d88e64d 5969 c = snew(struct ssh_channel);
51470298 5970 c->ssh = ssh;
32874aea 5971
51470298 5972 remid = ssh2_pkt_getuint32(ssh);
5973 winsize = ssh2_pkt_getuint32(ssh);
5974 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 5975
32874aea 5976 if (typelen == 3 && !memcmp(type, "x11", 3)) {
df85f78b 5977 char *addrstr;
5978
5979 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5980 addrstr = snewn(peeraddrlen+1, char);
b3ebaa28 5981 memcpy(addrstr, peeraddr, peeraddrlen);
5982 peeraddr[peeraddrlen] = '\0';
2e5b14c0 5983 peerport = ssh2_pkt_getuint32(ssh);
b3ebaa28 5984
51470298 5985 if (!ssh->X11_fwd_enabled)
32874aea 5986 error = "X11 forwarding is not enabled";
86916870 5987 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
2e5b14c0 5988 ssh->x11auth, addrstr, peerport,
e8fa8f62 5989 &ssh->cfg) != NULL) {
32874aea 5990 error = "Unable to open an X11 connection";
5991 } else {
5992 c->type = CHAN_X11;
5993 }
b3ebaa28 5994
5995 sfree(addrstr);
bc240b21 5996 } else if (typelen == 15 &&
5997 !memcmp(type, "forwarded-tcpip", 15)) {
5998 struct ssh_rportfwd pf, *realpf;
5999 char *dummy;
6000 int dummylen;
51470298 6001 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6002 pf.sport = ssh2_pkt_getuint32(ssh);
2e5b14c0 6003 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6004 peerport = ssh2_pkt_getuint32(ssh);
51470298 6005 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 6006 if (realpf == NULL) {
6007 error = "Remote port is not recognised";
6008 } else {
cbe2d68f 6009 const char *e = pfd_newconnect(&c->u.pfd.s,
6010 realpf->dhost,
6011 realpf->dport, c,
6012 &ssh->cfg);
57356d63 6013 logeventf(ssh, "Received remote port open request"
6014 " for %s:%d", realpf->dhost, realpf->dport);
bc240b21 6015 if (e != NULL) {
57356d63 6016 logeventf(ssh, "Port open failed: %s", e);
bc240b21 6017 error = "Port open failed";
6018 } else {
6019 logevent("Forwarded port opened successfully");
6020 c->type = CHAN_SOCKDATA;
6021 }
6022 }
32874aea 6023 } else if (typelen == 22 &&
36c2a3e9 6024 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 6025 if (!ssh->agentfwd_enabled)
32874aea 6026 error = "Agent forwarding is not enabled";
36c2a3e9 6027 else {
32874aea 6028 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 6029 c->u.a.lensofar = 0;
32874aea 6030 }
6031 } else {
6032 error = "Unsupported channel type requested";
6033 }
6034
bc240b21 6035 c->remoteid = remid;
32874aea 6036 if (error) {
51470298 6037 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6038 ssh2_pkt_adduint32(ssh, c->remoteid);
6039 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6040 ssh2_pkt_addstring(ssh, error);
6041 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6042 ssh2_pkt_send(ssh);
32874aea 6043 sfree(c);
6044 } else {
51470298 6045 c->localid = alloc_channel_id(ssh);
32874aea 6046 c->closes = 0;
5471d09a 6047 c->v.v2.locwindow = OUR_V2_WINSIZE;
6048 c->v.v2.remwindow = winsize;
6049 c->v.v2.remmaxpkt = pktsize;
6050 bufchain_init(&c->v.v2.outbuffer);
51470298 6051 add234(ssh->channels, c);
6052 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6053 ssh2_pkt_adduint32(ssh, c->remoteid);
6054 ssh2_pkt_adduint32(ssh, c->localid);
6055 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6056 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6057 ssh2_pkt_send(ssh);
32874aea 6058 }
7cca0d81 6059 } else {
6b5cf8b4 6060 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 6061 crStopV;
7cca0d81 6062 }
6063 } else {
32874aea 6064 /*
6065 * We have spare data. Add it to the channel buffer.
6066 */
d8baa528 6067 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6068 s->try_send = TRUE;
32874aea 6069 }
51470298 6070 if (s->try_send) {
32874aea 6071 int i;
6072 struct ssh_channel *c;
6073 /*
6074 * Try to send data on all channels if we can.
6075 */
51470298 6076 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6077 int bufsize;
6078 if (c->closes)
6079 continue; /* don't send on closing channels */
6080 bufsize = ssh2_try_send(c);
5471d09a 6081 if (bufsize == 0) {
6082 switch (c->type) {
6083 case CHAN_MAINSESSION:
6084 /* stdin need not receive an unthrottle
6085 * notification since it will be polled */
6086 break;
6087 case CHAN_X11:
6088 x11_unthrottle(c->u.x11.s);
6089 break;
6090 case CHAN_AGENT:
6091 /* agent sockets are request/response and need no
6092 * buffer management */
6093 break;
6094 case CHAN_SOCKDATA:
6095 pfd_unthrottle(c->u.pfd.s);
6096 break;
6097 }
6098 }
6099 }
7cca0d81 6100 }
e5574168 6101 }
6102
6103 crFinishV;
6104}
6105
6106/*
7cca0d81 6107 * Handle the top-level SSH2 protocol.
6108 */
51470298 6109static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 6110{
51470298 6111 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 6112 return;
51470298 6113 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 6114}
6115
6116/*
8df7a775 6117 * Called to set up the connection.
374330e2 6118 *
6119 * Returns an error message, or NULL on success.
374330e2 6120 */
cbe2d68f 6121static const char *ssh_init(void *frontend_handle, void **backend_handle,
6122 Config *cfg,
6123 char *host, int port, char **realhost, int nodelay)
32874aea 6124{
cbe2d68f 6125 const char *p;
51470298 6126 Ssh ssh;
6127
3d88e64d 6128 ssh = snew(struct ssh_tag);
86916870 6129 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 6130 ssh->version = 0; /* when not ready yet */
51470298 6131 ssh->s = NULL;
6132 ssh->cipher = NULL;
371e569c 6133 ssh->v1_cipher_ctx = NULL;
0183b242 6134 ssh->crcda_ctx = NULL;
51470298 6135 ssh->cscipher = NULL;
371e569c 6136 ssh->cs_cipher_ctx = NULL;
51470298 6137 ssh->sccipher = NULL;
371e569c 6138 ssh->sc_cipher_ctx = NULL;
51470298 6139 ssh->csmac = NULL;
a8327734 6140 ssh->cs_mac_ctx = NULL;
51470298 6141 ssh->scmac = NULL;
e0e1a00d 6142 ssh->sc_mac_ctx = NULL;
51470298 6143 ssh->cscomp = NULL;
5366aed8 6144 ssh->cs_comp_ctx = NULL;
51470298 6145 ssh->sccomp = NULL;
5366aed8 6146 ssh->sc_comp_ctx = NULL;
51470298 6147 ssh->kex = NULL;
389aa499 6148 ssh->kex_ctx = NULL;
51470298 6149 ssh->hostkey = NULL;
6150 ssh->exitcode = -1;
6151 ssh->state = SSH_STATE_PREPACKET;
6152 ssh->size_needed = FALSE;
6153 ssh->eof_needed = FALSE;
b9d7bcad 6154 ssh->ldisc = NULL;
a8327734 6155 ssh->logctx = NULL;
51470298 6156 {
6157 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6158 ssh->pktin = ssh->pktout = empty;
6159 }
6160 ssh->deferred_send_data = NULL;
6161 ssh->deferred_len = 0;
6162 ssh->deferred_size = 0;
6163 ssh->fallback_cmd = 0;
6164 ssh->pkt_ctx = 0;
302121de 6165 ssh->x11auth = NULL;
be738459 6166 ssh->v1_compressing = FALSE;
51470298 6167 ssh->v2_outgoing_sequence = 0;
6168 ssh->ssh1_rdpkt_crstate = 0;
6169 ssh->ssh2_rdpkt_crstate = 0;
6170 ssh->do_ssh_init_crstate = 0;
6171 ssh->ssh_gotdata_crstate = 0;
6172 ssh->ssh1_protocol_crstate = 0;
6173 ssh->do_ssh1_login_crstate = 0;
6174 ssh->do_ssh2_transport_crstate = 0;
6175 ssh->do_ssh2_authconn_crstate = 0;
6176 ssh->do_ssh_init_state = NULL;
6177 ssh->do_ssh1_login_state = NULL;
6178 ssh->do_ssh2_transport_state = NULL;
6179 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 6180 ssh->mainchan = NULL;
968d2d92 6181 ssh->throttled_all = 0;
6182 ssh->v1_stdout_throttling = 0;
51470298 6183
6184 *backend_handle = ssh;
32874aea 6185
8f203108 6186#ifdef MSCRYPTOAPI
32874aea 6187 if (crypto_startup() == 0)
8f203108 6188 return "Microsoft high encryption pack not installed!";
6189#endif
374330e2 6190
51470298 6191 ssh->frontend = frontend_handle;
86916870 6192 ssh->term_width = ssh->cfg.width;
6193 ssh->term_height = ssh->cfg.height;
887035a5 6194
fabd1805 6195 ssh->channels = NULL;
6196 ssh->rportfwds = NULL;
6197
51470298 6198 ssh->send_ok = 0;
6199 ssh->editing = 0;
6200 ssh->echoing = 0;
6201 ssh->v1_throttle_count = 0;
6202 ssh->overall_bufsize = 0;
6203 ssh->fallback_cmd = 0;
8df7a775 6204
3648d4c5 6205 ssh->protocol = NULL;
6206
51470298 6207 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 6208 if (p != NULL)
6209 return p;
374330e2 6210
374330e2 6211 return NULL;
6212}
6213
fabd1805 6214static void ssh_free(void *handle)
6215{
6216 Ssh ssh = (Ssh) handle;
6217 struct ssh_channel *c;
6218 struct ssh_rportfwd *pf;
6219
6220 if (ssh->v1_cipher_ctx)
6221 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6222 if (ssh->cs_cipher_ctx)
6223 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6224 if (ssh->sc_cipher_ctx)
6225 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6226 if (ssh->cs_mac_ctx)
6227 ssh->csmac->free_context(ssh->cs_mac_ctx);
6228 if (ssh->sc_mac_ctx)
6229 ssh->scmac->free_context(ssh->sc_mac_ctx);
6230 if (ssh->cs_comp_ctx)
6231 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6232 if (ssh->sc_comp_ctx)
6233 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6234 if (ssh->kex_ctx)
6235 dh_cleanup(ssh->kex_ctx);
6236 sfree(ssh->savedhost);
6237
6238 if (ssh->channels) {
6239 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6240 switch (c->type) {
6241 case CHAN_X11:
6242 if (c->u.x11.s != NULL)
6243 x11_close(c->u.x11.s);
6244 break;
6245 case CHAN_SOCKDATA:
6246 if (c->u.pfd.s != NULL)
6247 pfd_close(c->u.pfd.s);
6248 break;
6249 }
6250 sfree(c);
6251 }
6252 freetree234(ssh->channels);
6253 }
6254
6255 if (ssh->rportfwds) {
6256 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6257 sfree(pf);
6258 freetree234(ssh->rportfwds);
6259 }
6260 sfree(ssh->deferred_send_data);
6261 if (ssh->x11auth)
6262 x11_free_auth(ssh->x11auth);
6263 sfree(ssh->do_ssh_init_state);
6264 sfree(ssh->do_ssh1_login_state);
6265 sfree(ssh->do_ssh2_transport_state);
6266 sfree(ssh->do_ssh2_authconn_state);
6267
6268 if (ssh->s)
36f94d1f 6269 ssh_do_close(ssh);
fabd1805 6270 sfree(ssh);
6271}
6272
374330e2 6273/*
86916870 6274 * Reconfigure the SSH backend.
6275 *
6276 * Currently, this function does nothing very useful. In future,
6277 * however, we could do some handy things with it. For example, we
6278 * could make the port forwarding configurer active in the Change
6279 * Settings box, and this routine could close down existing
6280 * forwardings and open up new ones in response to changes.
6281 */
6282static void ssh_reconfig(void *handle, Config *cfg)
6283{
6284 Ssh ssh = (Ssh) handle;
6285 ssh->cfg = *cfg; /* STRUCTURE COPY */
6286}
6287
6288/*
374330e2 6289 * Called to send data down the Telnet connection.
6290 */
51470298 6291static int ssh_send(void *handle, char *buf, int len)
32874aea 6292{
51470298 6293 Ssh ssh = (Ssh) handle;
6294
6295 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6296 return 0;
374330e2 6297
d8baa528 6298 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 6299
51470298 6300 return ssh_sendbuffer(ssh);
5471d09a 6301}
6302
6303/*
6304 * Called to query the current amount of buffered stdin data.
6305 */
51470298 6306static int ssh_sendbuffer(void *handle)
5471d09a 6307{
51470298 6308 Ssh ssh = (Ssh) handle;
5471d09a 6309 int override_value;
6310
51470298 6311 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6312 return 0;
6313
6314 /*
6315 * If the SSH socket itself has backed up, add the total backup
6316 * size on that to any individual buffer on the stdin channel.
6317 */
6318 override_value = 0;
51470298 6319 if (ssh->throttled_all)
6320 override_value = ssh->overall_bufsize;
5471d09a 6321
51470298 6322 if (ssh->version == 1) {
5471d09a 6323 return override_value;
51470298 6324 } else if (ssh->version == 2) {
6325 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 6326 return override_value;
6327 else
51470298 6328 return (override_value +
6329 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 6330 }
6331
6332 return 0;
374330e2 6333}
6334
6335/*
6e48c3fe 6336 * Called to set the size of the window from SSH's POV.
374330e2 6337 */
51470298 6338static void ssh_size(void *handle, int width, int height)
32874aea 6339{
51470298 6340 Ssh ssh = (Ssh) handle;
6341
6342 ssh->term_width = width;
6343 ssh->term_height = height;
f278d6f8 6344
51470298 6345 switch (ssh->state) {
374330e2 6346 case SSH_STATE_BEFORE_SIZE:
3687d221 6347 case SSH_STATE_PREPACKET:
21248260 6348 case SSH_STATE_CLOSED:
374330e2 6349 break; /* do nothing */
6350 case SSH_STATE_INTERMED:
51470298 6351 ssh->size_needed = TRUE; /* buffer for later */
374330e2 6352 break;
6353 case SSH_STATE_SESSION:
86916870 6354 if (!ssh->cfg.nopty) {
51470298 6355 if (ssh->version == 1) {
6356 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6357 PKT_INT, ssh->term_height,
6358 PKT_INT, ssh->term_width,
32874aea 6359 PKT_INT, 0, PKT_INT, 0, PKT_END);
6360 } else {
51470298 6361 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6362 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6363 ssh2_pkt_addstring(ssh, "window-change");
6364 ssh2_pkt_addbool(ssh, 0);
6365 ssh2_pkt_adduint32(ssh, ssh->term_width);
6366 ssh2_pkt_adduint32(ssh, ssh->term_height);
6367 ssh2_pkt_adduint32(ssh, 0);
6368 ssh2_pkt_adduint32(ssh, 0);
6369 ssh2_pkt_send(ssh);
32874aea 6370 }
6371 }
6372 break;
374330e2 6373 }
6374}
6375
6376/*
125105d1 6377 * Return a list of the special codes that make sense in this
6378 * protocol.
6379 */
6380static const struct telnet_special *ssh_get_specials(void *handle)
6381{
6382 Ssh ssh = (Ssh) handle;
6383
6384 if (ssh->version == 1) {
6385 static const struct telnet_special ssh1_specials[] = {
6386 {"IGNORE message", TS_NOP},
6387 {NULL, 0}
6388 };
6389 return ssh1_specials;
6390 } else if (ssh->version == 2) {
6391 static const struct telnet_special ssh2_specials[] = {
6392 {"Break", TS_BRK},
6393 {"IGNORE message", TS_NOP},
6394 {NULL, 0}
6395 };
6396 return ssh2_specials;
6397 } else
6398 return NULL;
6399}
6400
6401/*
6abbf9e3 6402 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6403 * can send an EOF and collect resulting output (e.g. `plink
6404 * hostname sort').
374330e2 6405 */
51470298 6406static void ssh_special(void *handle, Telnet_Special code)
32874aea 6407{
51470298 6408 Ssh ssh = (Ssh) handle;
6409
6abbf9e3 6410 if (code == TS_EOF) {
51470298 6411 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6412 /*
6413 * Buffer the EOF in case we are pre-SESSION, so we can
6414 * send it as soon as we reach SESSION.
6415 */
6416 if (code == TS_EOF)
51470298 6417 ssh->eof_needed = TRUE;
32874aea 6418 return;
6419 }
51470298 6420 if (ssh->version == 1) {
6421 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6422 } else {
51470298 6423 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6424 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6425 ssh2_pkt_send(ssh);
32874aea 6426 }
6427 logevent("Sent EOF message");
125105d1 6428 } else if (code == TS_PING || code == TS_NOP) {
51470298 6429 if (ssh->state == SSH_STATE_CLOSED
6430 || ssh->state == SSH_STATE_PREPACKET) return;
6431 if (ssh->version == 1) {
6432 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6433 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6434 } else {
51470298 6435 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6436 ssh2_pkt_addstring_start(ssh);
6437 ssh2_pkt_send(ssh);
32874aea 6438 }
125105d1 6439 } else if (code == TS_BRK) {
6440 if (ssh->state == SSH_STATE_CLOSED
6441 || ssh->state == SSH_STATE_PREPACKET) return;
6442 if (ssh->version == 1) {
6443 logevent("Unable to send BREAK signal in SSH1");
6444 } else {
6445 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6446 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6447 ssh2_pkt_addstring(ssh, "break");
6448 ssh2_pkt_addbool(ssh, 0);
6449 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6450 ssh2_pkt_send(ssh);
6451 }
6abbf9e3 6452 } else {
32874aea 6453 /* do nothing */
6abbf9e3 6454 }
374330e2 6455}
6456
51470298 6457void *new_sock_channel(void *handle, Socket s)
d74d141c 6458{
51470298 6459 Ssh ssh = (Ssh) handle;
d74d141c 6460 struct ssh_channel *c;
3d88e64d 6461 c = snew(struct ssh_channel);
51470298 6462 c->ssh = ssh;
d74d141c 6463
6464 if (c) {
bc240b21 6465 c->remoteid = -1; /* to be set when open confirmed */
51470298 6466 c->localid = alloc_channel_id(ssh);
d74d141c 6467 c->closes = 0;
bc240b21 6468 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6469 c->u.pfd.s = s;
013dd8c0 6470 bufchain_init(&c->v.v2.outbuffer);
51470298 6471 add234(ssh->channels, c);
d74d141c 6472 }
6473 return c;
6474}
6475
5471d09a 6476/*
6477 * This is called when stdout/stderr (the entity to which
6478 * from_backend sends data) manages to clear some backlog.
6479 */
ae9ae89f 6480static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6481{
51470298 6482 Ssh ssh = (Ssh) handle;
6483 if (ssh->version == 1) {
6484 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6485 ssh->v1_stdout_throttling = 0;
6486 ssh1_throttle(ssh, -1);
5471d09a 6487 }
6488 } else {
51470298 6489 if (ssh->mainchan && ssh->mainchan->closes == 0)
6490 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6491 }
6492}
6493
6b78788a 6494void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6495{
6496 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6497 Ssh ssh = c->ssh;
d74d141c 6498
57356d63 6499 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 6500
51470298 6501 if (ssh->version == 1) {
6502 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6503 PKT_INT, c->localid,
6504 PKT_STR, hostname,
6505 PKT_INT, port,
6506 //PKT_STR, <org:orgport>,
6507 PKT_END);
6508 } else {
51470298 6509 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6510 ssh2_pkt_addstring(ssh, "direct-tcpip");
6511 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6512 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6513 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6514 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6515 ssh2_pkt_addstring(ssh, hostname);
6516 ssh2_pkt_adduint32(ssh, port);
bc240b21 6517 /*
6518 * We make up values for the originator data; partly it's
6519 * too much hassle to keep track, and partly I'm not
6520 * convinced the server should be told details like that
6521 * about my local network configuration.
6522 */
51470298 6523 ssh2_pkt_addstring(ssh, "client-side-connection");
6524 ssh2_pkt_adduint32(ssh, 0);
6525 ssh2_pkt_send(ssh);
bc240b21 6526 }
d74d141c 6527}
6528
6529
51470298 6530static Socket ssh_socket(void *handle)
32874aea 6531{
51470298 6532 Ssh ssh = (Ssh) handle;
6533 return ssh->s;
32874aea 6534}
8ccc75b0 6535
51470298 6536static int ssh_sendok(void *handle)
32874aea 6537{
51470298 6538 Ssh ssh = (Ssh) handle;
6539 return ssh->send_ok;
32874aea 6540}
fb09bf1c 6541
51470298 6542static int ssh_ldisc(void *handle, int option)
32874aea 6543{
51470298 6544 Ssh ssh = (Ssh) handle;
32874aea 6545 if (option == LD_ECHO)
51470298 6546 return ssh->echoing;
32874aea 6547 if (option == LD_EDIT)
51470298 6548 return ssh->editing;
0965bee0 6549 return FALSE;
6550}
6551
b9d7bcad 6552static void ssh_provide_ldisc(void *handle, void *ldisc)
6553{
6554 Ssh ssh = (Ssh) handle;
6555 ssh->ldisc = ldisc;
6556}
6557
a8327734 6558static void ssh_provide_logctx(void *handle, void *logctx)
6559{
6560 Ssh ssh = (Ssh) handle;
6561 ssh->logctx = logctx;
6562}
6563
51470298 6564static int ssh_return_exitcode(void *handle)
6565{
6566 Ssh ssh = (Ssh) handle;
3bb2f322 6567 if (ssh->s != NULL)
6568 return -1;
6569 else
6570 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 6571}
6572
6573/*
6574 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6575 * that fails. This variable is the means by which scp.c can reach
6576 * into the SSH code and find out which one it got.
6577 */
6578extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6579{
51470298 6580 Ssh ssh = (Ssh) handle;
6581 return ssh->fallback_cmd;
d8d6c7e5 6582}
6583
374330e2 6584Backend ssh_backend = {
6585 ssh_init,
fabd1805 6586 ssh_free,
86916870 6587 ssh_reconfig,
374330e2 6588 ssh_send,
5471d09a 6589 ssh_sendbuffer,
374330e2 6590 ssh_size,
4017be6d 6591 ssh_special,
125105d1 6592 ssh_get_specials,
8ccc75b0 6593 ssh_socket,
d8d6c7e5 6594 ssh_return_exitcode,
97db3be4 6595 ssh_sendok,
0965bee0 6596 ssh_ldisc,
b9d7bcad 6597 ssh_provide_ldisc,
a8327734 6598 ssh_provide_logctx,
5471d09a 6599 ssh_unthrottle,
97db3be4 6600 22
bc240b21 6601};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator