projects / u / mdw / putty / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Add an explicit message about lack of support for PASSWD_CHANGEREQ in a
[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 */
d1aaf71d 107#define SSH2_PKTCTX_DHGROUP 0x0001
00db133f 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
83e7d008 165/* 64 was BUG_SSH2_DH_GEX, now spare */
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);
d1aaf71d 225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 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
9a10ecf4 270/* Enumeration values for fields in SSH-1 packets */
271enum {
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
276};
972a41c8 277
acddebd9 278/*
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
281 * read
282 *
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
284 *
285 * which explains the theory behind these macros.
b624d1e6 286 *
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
291 *
292 * - right-click ssh.c in the FileView
293 * - click Settings
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
acddebd9 297 */
51470298 298#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
299#define crState(t) \
300 struct t *s; \
3d88e64d 301 if (!ssh->t) ssh->t = snew(struct t); \
51470298 302 s = ssh->t;
303#define crFinish(z) } *crLine = 0; return (z); }
304#define crFinishV } *crLine = 0; return; }
374330e2 305#define crReturn(z) \
306 do {\
51470298 307 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 308 } while (0)
309#define crReturnV \
310 do {\
51470298 311 *crLine=__LINE__; return; case __LINE__:;\
374330e2 312 } while (0)
51470298 313#define crStop(z) do{ *crLine = 0; return (z); }while(0)
314#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 315#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 316#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 317
51470298 318typedef struct ssh_tag *Ssh;
ff3187f6 319struct Packet;
320
321static struct Packet *ssh2_pkt_init(int pkt_type);
322static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324static void ssh2_pkt_addstring_start(struct Packet *);
325static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 328static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 329static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330static int ssh2_pkt_construct(Ssh, struct Packet *);
331static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 332static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 333static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
3d63ca2e 337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
85cc02bb 363const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 364
e0e1a00d 365static void *nullmac_make_context(void)
366{
367 return NULL;
368}
369static void nullmac_free_context(void *handle)
370{
371}
372static void nullmac_key(void *handle, unsigned char *key)
32874aea 373{
374}
e0e1a00d 375static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 376 unsigned long seq)
377{
378}
e0e1a00d 379static int nullmac_verify(void *handle, unsigned char *blk, int len,
380 unsigned long seq)
32874aea 381{
382 return 1;
383}
57476f6b 384const static struct ssh_mac ssh_mac_none = {
e0e1a00d 385 nullmac_make_context, nullmac_free_context, nullmac_key,
386 nullmac_generate, nullmac_verify, "none", 0
e5574168 387};
8b2715b2 388const static struct ssh_mac *macs[] = {
32874aea 389 &ssh_sha1, &ssh_md5, &ssh_mac_none
390};
8b2715b2 391const static struct ssh_mac *buggymacs[] = {
32874aea 392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
393};
e5574168 394
5366aed8 395static void *ssh_comp_none_init(void)
396{
397 return NULL;
398}
399static void ssh_comp_none_cleanup(void *handle)
32874aea 400{
401}
5366aed8 402static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 403 unsigned char **outblock, int *outlen)
404{
405 return 0;
406}
5366aed8 407static int ssh_comp_none_disable(void *handle)
32874aea 408{
4ba9b64b 409 return 0;
410}
57476f6b 411const static struct ssh_compress ssh_comp_none = {
4ba9b64b 412 "none",
5366aed8 413 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_disable, NULL
e5574168 416};
4ba9b64b 417extern const struct ssh_compress ssh_zlib;
418const static struct ssh_compress *compressions[] = {
32874aea 419 &ssh_zlib, &ssh_comp_none
420};
374330e2 421
32874aea 422enum { /* channel types */
783415f8 423 CHAN_MAINSESSION,
424 CHAN_X11,
425 CHAN_AGENT,
bc240b21 426 CHAN_SOCKDATA,
427 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 428};
429
dacbd0e8 430/*
431 * 2-3-4 tree storing channels.
432 */
433struct ssh_channel {
51470298 434 Ssh ssh; /* pointer back to main context */
d211621f 435 unsigned remoteid, localid;
dacbd0e8 436 int type;
0357890f 437 /*
438 * In SSH1, this value contains four bits:
439 *
440 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
441 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
443 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
444 *
445 * A channel is completely finished with when all four bits are set.
446 */
dacbd0e8 447 int closes;
5471d09a 448 union {
449 struct ssh1_data_channel {
450 int throttling;
451 } v1;
452 struct ssh2_data_channel {
453 bufchain outbuffer;
454 unsigned remwindow, remmaxpkt;
455 unsigned locwindow;
456 } v2;
457 } v;
dacbd0e8 458 union {
32874aea 459 struct ssh_agent_channel {
460 unsigned char *message;
461 unsigned char msglen[4];
a03c9f9c 462 unsigned lensofar, totallen;
32874aea 463 } a;
464 struct ssh_x11_channel {
465 Socket s;
466 } x11;
d74d141c 467 struct ssh_pfd_channel {
468 Socket s;
469 } pfd;
dacbd0e8 470 } u;
471};
57476f6b 472
d74d141c 473/*
bc240b21 474 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
475 * 2 use this structure in different ways, reflecting SSH 2's
476 * altogether saner approach to port forwarding.
477 *
478 * In SSH 1, you arrange a remote forwarding by sending the server
479 * the remote port number, and the local destination host:port.
480 * When a connection comes in, the server sends you back that
481 * host:port pair, and you connect to it. This is a ready-made
482 * security hole if you're not on the ball: a malicious server
483 * could send you back _any_ host:port pair, so if you trustingly
484 * connect to the address it gives you then you've just opened the
485 * entire inside of your corporate network just by connecting
486 * through it to a dodgy SSH server. Hence, we must store a list of
487 * host:port pairs we _are_ trying to forward to, and reject a
488 * connection request from the server if it's not in the list.
489 *
490 * In SSH 2, each side of the connection minds its own business and
491 * doesn't send unnecessary information to the other. You arrange a
492 * remote forwarding by sending the server just the remote port
493 * number. When a connection comes in, the server tells you which
494 * of its ports was connected to; and _you_ have to remember what
495 * local host:port pair went with that port number.
496 *
06fadff5 497 * Hence, in SSH 1 this structure is indexed by destination
498 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 499 */
fda2feb1 500struct ssh_portfwd; /* forward declaration */
501
d74d141c 502struct ssh_rportfwd {
bc240b21 503 unsigned sport, dport;
504 char dhost[256];
06fadff5 505 char *sportdesc;
fda2feb1 506 struct ssh_portfwd *pfrec;
d74d141c 507};
fda2feb1 508#define free_rportfwd(pf) ( \
509 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
510
511/*
512 * Separately to the rportfwd tree (which is for looking up port
513 * open requests from the server), a tree of _these_ structures is
514 * used to keep track of all the currently open port forwardings,
515 * so that we can reconfigure in mid-session if the user requests
516 * it.
517 */
518struct ssh_portfwd {
84328ddb 519 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 520 int type;
521 unsigned sport, dport;
522 char *saddr, *daddr;
3fe92132 523 char *sserv, *dserv;
fda2feb1 524 struct ssh_rportfwd *remote;
05581745 525 int addressfamily;
fda2feb1 526 void *local;
527};
528#define free_portfwd(pf) ( \
3fe92132 529 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
530 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 531
57476f6b 532struct Packet {
533 long length;
534 int type;
b09eaa88 535 unsigned long sequence;
57476f6b 536 unsigned char *data;
537 unsigned char *body;
538 long savedpos;
539 long maxlen;
9442dd57 540 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 541
542 /*
543 * State associated with packet logging
544 */
545 int logmode;
546 int nblanks;
547 struct logblank_t *blanks;
57476f6b 548};
549
ff3187f6 550static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
551 struct Packet *pktin);
552static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
553 struct Packet *pktin);
b09eaa88 554static void ssh1_protocol_setup(Ssh ssh);
555static void ssh2_protocol_setup(Ssh ssh);
51470298 556static void ssh_size(void *handle, int width, int height);
557static void ssh_special(void *handle, Telnet_Special);
5471d09a 558static int ssh2_try_send(struct ssh_channel *c);
51470298 559static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
560static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 561static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 562static int ssh_sendbuffer(void *handle);
36f94d1f 563static void ssh_do_close(Ssh ssh);
ff3187f6 564static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
565static int ssh2_pkt_getbool(struct Packet *pkt);
566static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 567static void ssh2_timer(void *ctx, long now);
568static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
569 struct Packet *pktin);
57476f6b 570
51470298 571struct rdpkt1_state_tag {
57476f6b 572 long len, pad, biglen, to_read;
573 unsigned long realcrc, gotcrc;
574 unsigned char *p;
575 int i;
576 int chunk;
ff3187f6 577 struct Packet *pktin;
51470298 578};
57476f6b 579
51470298 580struct rdpkt2_state_tag {
960e736a 581 long len, pad, payload, packetlen, maclen;
582 int i;
583 int cipherblk;
584 unsigned long incoming_sequence;
ff3187f6 585 struct Packet *pktin;
51470298 586};
587
b09eaa88 588typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 589typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
590
591struct queued_handler;
592struct queued_handler {
593 int msg1, msg2;
594 chandler_fn_t handler;
595 void *ctx;
596 struct queued_handler *next;
597};
b09eaa88 598
51470298 599struct ssh_tag {
600 const struct plug_function_table *fn;
601 /* the above field _must_ be first in the structure */
602
603 SHA_State exhash, exhashbase;
604
605 Socket s;
606
b9d7bcad 607 void *ldisc;
a8327734 608 void *logctx;
b9d7bcad 609
51470298 610 unsigned char session_key[32];
611 int v1_compressing;
612 int v1_remote_protoflags;
613 int v1_local_protoflags;
614 int agentfwd_enabled;
615 int X11_fwd_enabled;
616 int remote_bugs;
617 const struct ssh_cipher *cipher;
371e569c 618 void *v1_cipher_ctx;
0183b242 619 void *crcda_ctx;
51470298 620 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 621 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 622 const struct ssh_mac *csmac, *scmac;
e0e1a00d 623 void *cs_mac_ctx, *sc_mac_ctx;
51470298 624 const struct ssh_compress *cscomp, *sccomp;
5366aed8 625 void *cs_comp_ctx, *sc_comp_ctx;
51470298 626 const struct ssh_kex *kex;
627 const struct ssh_signkey *hostkey;
628 unsigned char v2_session_id[20];
27cd7fc2 629 void *kex_ctx;
51470298 630
631 char *savedhost;
632 int savedport;
633 int send_ok;
634 int echoing, editing;
635
636 void *frontend;
637
db219738 638 int ospeed, ispeed; /* temporaries */
51470298 639 int term_width, term_height;
640
641 tree234 *channels; /* indexed by local id */
642 struct ssh_channel *mainchan; /* primary session channel */
643 int exitcode;
644
fda2feb1 645 tree234 *rportfwds, *portfwds;
51470298 646
647 enum {
648 SSH_STATE_PREPACKET,
649 SSH_STATE_BEFORE_SIZE,
650 SSH_STATE_INTERMED,
651 SSH_STATE_SESSION,
652 SSH_STATE_CLOSED
653 } state;
654
655 int size_needed, eof_needed;
656
590f6a5f 657 struct Packet **queue;
658 int queuelen, queuesize;
659 int queueing;
51470298 660 unsigned char *deferred_send_data;
661 int deferred_len, deferred_size;
662
663 /*
664 * Gross hack: pscp will try to start SFTP but fall back to
665 * scp1 if that fails. This variable is the means by which
666 * scp.c can reach into the SSH code and find out which one it
667 * got.
668 */
669 int fallback_cmd;
670
671 /*
672 * Used for username and password input.
673 */
674 char *userpass_input_buffer;
675 int userpass_input_buflen;
676 int userpass_input_bufpos;
677 int userpass_input_echo;
678
51470298 679 int pkt_ctx;
680
302121de 681 void *x11auth;
682
51470298 683 int version;
684 int v1_throttle_count;
685 int overall_bufsize;
686 int throttled_all;
687 int v1_stdout_throttling;
688 int v2_outgoing_sequence;
689
690 int ssh1_rdpkt_crstate;
691 int ssh2_rdpkt_crstate;
692 int do_ssh_init_crstate;
693 int ssh_gotdata_crstate;
51470298 694 int do_ssh1_login_crstate;
b09eaa88 695 int do_ssh1_connection_crstate;
51470298 696 int do_ssh2_transport_crstate;
697 int do_ssh2_authconn_crstate;
698
699 void *do_ssh_init_state;
700 void *do_ssh1_login_state;
701 void *do_ssh2_transport_state;
702 void *do_ssh2_authconn_state;
703
704 struct rdpkt1_state_tag rdpkt1_state;
705 struct rdpkt2_state_tag rdpkt2_state;
706
b09eaa88 707 /* ssh1 and ssh2 use this for different things, but both use it */
708 int protocol_initial_phase_done;
709
ff3187f6 710 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
711 struct Packet *pkt);
712 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 713
714 /*
715 * We maintain a full _copy_ of a Config structure here, not
716 * merely a pointer to it. That way, when we're passed a new
717 * one for reconfiguration, we can check the differences and
718 * potentially reconfigure port forwardings etc in mid-session.
719 */
720 Config cfg;
839f10db 721
722 /*
723 * Used to transfer data back from async agent callbacks.
724 */
725 void *agent_response;
726 int agent_response_len;
b09eaa88 727
728 /*
729 * Dispatch table for packet types that we may have to deal
730 * with at any time.
731 */
732 handler_fn_t packet_dispatch[256];
39934deb 733
734 /*
06fadff5 735 * Queues of one-off handler functions for success/failure
736 * indications from a request.
737 */
738 struct queued_handler *qhead, *qtail;
739
740 /*
39934deb 741 * This module deals with sending keepalives.
742 */
743 Pinger pinger;
9442dd57 744
745 /*
746 * Track incoming and outgoing data sizes and time, for
747 * size-based rekeys.
748 */
749 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 750 unsigned long max_data_size;
9442dd57 751 int kex_in_progress;
e6c1536e 752 long next_rekey, last_rekey;
e13bba36 753 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 754};
960e736a 755
382908ad 756#define logevent(s) logevent(ssh->frontend, s)
a8327734 757
758/* logevent, only printf-formatted. */
cbe2d68f 759static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 760{
761 va_list ap;
57356d63 762 char *buf;
a8327734 763
764 va_start(ap, fmt);
57356d63 765 buf = dupvprintf(fmt, ap);
a8327734 766 va_end(ap);
57356d63 767 logevent(buf);
57356d63 768 sfree(buf);
a8327734 769}
770
6b5cf8b4 771#define bombout(msg) \
772 do { \
773 char *text = dupprintf msg; \
36f94d1f 774 ssh_do_close(ssh); \
6b5cf8b4 775 logevent(text); \
776 connection_fatal(ssh->frontend, "%s", text); \
777 sfree(text); \
778 } while (0)
a8327734 779
9a10ecf4 780/* Functions to leave bits out of the SSH packet log file. */
781
ff3187f6 782static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 783{
784 if (ssh->cfg.logomitpass)
ff3187f6 785 pkt->logmode = blanktype;
9a10ecf4 786}
787
ff3187f6 788static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 789{
790 if (ssh->cfg.logomitdata)
ff3187f6 791 pkt->logmode = blanktype;
9a10ecf4 792}
793
ff3187f6 794static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 795{
ff3187f6 796 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 797}
798
32874aea 799static int ssh_channelcmp(void *av, void *bv)
800{
801 struct ssh_channel *a = (struct ssh_channel *) av;
802 struct ssh_channel *b = (struct ssh_channel *) bv;
803 if (a->localid < b->localid)
804 return -1;
805 if (a->localid > b->localid)
806 return +1;
dacbd0e8 807 return 0;
808}
32874aea 809static int ssh_channelfind(void *av, void *bv)
810{
811 unsigned *a = (unsigned *) av;
812 struct ssh_channel *b = (struct ssh_channel *) bv;
813 if (*a < b->localid)
814 return -1;
815 if (*a > b->localid)
816 return +1;
dacbd0e8 817 return 0;
818}
819
bc240b21 820static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 821{
822 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
823 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
824 int i;
bc240b21 825 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 826 return i < 0 ? -1 : +1;
bc240b21 827 if (a->dport > b->dport)
828 return +1;
829 if (a->dport < b->dport)
830 return -1;
831 return 0;
832}
833
834static int ssh_rportcmp_ssh2(void *av, void *bv)
835{
836 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
837 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 838
bc240b21 839 if (a->sport > b->sport)
d74d141c 840 return +1;
bc240b21 841 if (a->sport < b->sport)
842 return -1;
d74d141c 843 return 0;
844}
845
fda2feb1 846/*
847 * Special form of strcmp which can cope with NULL inputs. NULL is
848 * defined to sort before even the empty string.
849 */
850static int nullstrcmp(const char *a, const char *b)
851{
852 if (a == NULL && b == NULL)
853 return 0;
854 if (a == NULL)
855 return -1;
856 if (b == NULL)
857 return +1;
858 return strcmp(a, b);
859}
860
861static int ssh_portcmp(void *av, void *bv)
862{
863 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
864 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
865 int i;
866 if (a->type > b->type)
867 return +1;
868 if (a->type < b->type)
869 return -1;
84328ddb 870 if (a->addressfamily > b->addressfamily)
871 return +1;
872 if (a->addressfamily < b->addressfamily)
873 return -1;
fda2feb1 874 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
875 return i < 0 ? -1 : +1;
876 if (a->sport > b->sport)
877 return +1;
878 if (a->sport < b->sport)
879 return -1;
880 if (a->type != 'D') {
881 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
882 return i < 0 ? -1 : +1;
883 if (a->dport > b->dport)
884 return +1;
885 if (a->dport < b->dport)
886 return -1;
887 }
888 return 0;
889}
890
51470298 891static int alloc_channel_id(Ssh ssh)
32874aea 892{
260f3dec 893 const unsigned CHANNEL_NUMBER_OFFSET = 256;
894 unsigned low, high, mid;
d2371c81 895 int tsize;
896 struct ssh_channel *c;
897
898 /*
899 * First-fit allocation of channel numbers: always pick the
900 * lowest unused one. To do this, binary-search using the
901 * counted B-tree to find the largest channel ID which is in a
902 * contiguous sequence from the beginning. (Precisely
903 * everything in that sequence must have ID equal to its tree
904 * index plus CHANNEL_NUMBER_OFFSET.)
905 */
51470298 906 tsize = count234(ssh->channels);
d2371c81 907
32874aea 908 low = -1;
909 high = tsize;
d2371c81 910 while (high - low > 1) {
911 mid = (high + low) / 2;
51470298 912 c = index234(ssh->channels, mid);
d2371c81 913 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
914 low = mid; /* this one is fine */
915 else
916 high = mid; /* this one is past it */
917 }
918 /*
919 * Now low points to either -1, or the tree index of the
920 * largest ID in the initial sequence.
921 */
922 {
923 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 924 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 925 }
926 return low + 1 + CHANNEL_NUMBER_OFFSET;
927}
928
9fab77dc 929static void c_write(Ssh ssh, const char *buf, int len)
32874aea 930{
67779be7 931 if ((flags & FLAG_STDERR)) {
32874aea 932 int i;
933 for (i = 0; i < len; i++)
934 if (buf[i] != '\r')
935 fputc(buf[i], stderr);
fb09bf1c 936 return;
937 }
51470298 938 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 939}
940
9fab77dc 941static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 942{
a209e957 943 int i;
944 for (i = 0; i < len; i++) {
32874aea 945 if (buf[i] == '\n')
51470298 946 c_write(ssh, "\r\n", 2);
32874aea 947 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 948 c_write(ssh, buf + i, 1);
a209e957 949 }
950}
951
9fab77dc 952static void c_write_str(Ssh ssh, const char *buf)
32874aea 953{
51470298 954 c_write(ssh, buf, strlen(buf));
1408a877 955}
956
ff3187f6 957static void ssh_free_packet(struct Packet *pkt)
958{
959 sfree(pkt->data);
960 sfree(pkt);
961}
962static struct Packet *ssh_new_packet(void)
963{
964 struct Packet *pkt = snew(struct Packet);
965
966 pkt->data = NULL;
967 pkt->maxlen = 0;
968 pkt->logmode = PKTLOG_EMIT;
969 pkt->nblanks = 0;
970 pkt->blanks = NULL;
971
972 return pkt;
973}
974
fb09bf1c 975/*
976 * Collect incoming data in the incoming packet buffer.
e5574168 977 * Decipher and verify the packet when it is completely read.
978 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 979 * Update the *data and *datalen variables.
ff3187f6 980 * Return a Packet structure when a packet is completed.
fb09bf1c 981 */
ff3187f6 982static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 983{
51470298 984 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 985
51470298 986 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 987
ff3187f6 988 st->pktin = ssh_new_packet();
989
990 st->pktin->type = 0;
991 st->pktin->length = 0;
374330e2 992
57476f6b 993 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 994 while ((*datalen) == 0)
ff3187f6 995 crReturn(NULL);
57476f6b 996 st->len = (st->len << 8) + **data;
fb09bf1c 997 (*data)++, (*datalen)--;
998 }
374330e2 999
57476f6b 1000 st->pad = 8 - (st->len % 8);
1001 st->biglen = st->len + st->pad;
ff3187f6 1002 st->pktin->length = st->len - 5;
fb09bf1c 1003
ae0500e5 1004 if (st->biglen < 0) {
1005 bombout(("Extremely large packet length from server suggests"
1006 " data stream corruption"));
ff3187f6 1007 ssh_free_packet(st->pktin);
1008 crStop(NULL);
ae0500e5 1009 }
1010
ff3187f6 1011 st->pktin->maxlen = st->biglen;
1012 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1013
57476f6b 1014 st->to_read = st->biglen;
ff3187f6 1015 st->p = st->pktin->data;
57476f6b 1016 while (st->to_read > 0) {
32874aea 1017 st->chunk = st->to_read;
fb09bf1c 1018 while ((*datalen) == 0)
ff3187f6 1019 crReturn(NULL);
57476f6b 1020 if (st->chunk > (*datalen))
1021 st->chunk = (*datalen);
1022 memcpy(st->p, *data, st->chunk);
1023 *data += st->chunk;
1024 *datalen -= st->chunk;
1025 st->p += st->chunk;
1026 st->to_read -= st->chunk;
fb09bf1c 1027 }
374330e2 1028
ff3187f6 1029 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1030 st->biglen, NULL)) {
6b5cf8b4 1031 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1032 ssh_free_packet(st->pktin);
1033 crStop(NULL);
9a3a93a5 1034 }
1035
51470298 1036 if (ssh->cipher)
ff3187f6 1037 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1038
ff3187f6 1039 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1040 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1041 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1042 bombout(("Incorrect CRC received on packet"));
ff3187f6 1043 ssh_free_packet(st->pktin);
1044 crStop(NULL);
fb09bf1c 1045 }
572f871e 1046
ff3187f6 1047 st->pktin->body = st->pktin->data + st->pad + 1;
1048 st->pktin->savedpos = 0;
4ba9b64b 1049
51470298 1050 if (ssh->v1_compressing) {
4ba9b64b 1051 unsigned char *decompblk;
1052 int decomplen;
36b8d9bb 1053 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1054 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1055 &decompblk, &decomplen)) {
1056 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1057 ssh_free_packet(st->pktin);
1058 crStop(NULL);
36b8d9bb 1059 }
4ba9b64b 1060
ff3187f6 1061 if (st->pktin->maxlen < st->pad + decomplen) {
1062 st->pktin->maxlen = st->pad + decomplen;
1063 st->pktin->data = sresize(st->pktin->data,
1064 st->pktin->maxlen + APIEXTRA,
3d88e64d 1065 unsigned char);
ff3187f6 1066 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1067 }
1068
ff3187f6 1069 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1070 sfree(decompblk);
ff3187f6 1071 st->pktin->length = decomplen - 1;
4ba9b64b 1072 }
1073
ff3187f6 1074 st->pktin->type = st->pktin->body[-1];
00db133f 1075
9a10ecf4 1076 /*
1077 * Log incoming packet, possibly omitting sensitive fields.
1078 */
1079 if (ssh->logctx) {
1080 int nblanks = 0;
1081 struct logblank_t blank;
1082 if (ssh->cfg.logomitdata) {
1083 int do_blank = FALSE, blank_prefix = 0;
1084 /* "Session data" packets - omit the data field */
ff3187f6 1085 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1086 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1087 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1088 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1089 do_blank = TRUE; blank_prefix = 4;
1090 }
1091 if (do_blank) {
1092 blank.offset = blank_prefix;
ff3187f6 1093 blank.len = st->pktin->length;
9a10ecf4 1094 blank.type = PKTLOG_OMIT;
1095 nblanks = 1;
1096 }
1097 }
a8327734 1098 log_packet(ssh->logctx,
ff3187f6 1099 PKT_INCOMING, st->pktin->type,
1100 ssh1_pkt_type(st->pktin->type),
1101 st->pktin->body, st->pktin->length,
9a10ecf4 1102 nblanks, &blank);
1103 }
00db133f 1104
ff3187f6 1105 crFinish(st->pktin);
fb09bf1c 1106}
1107
ff3187f6 1108static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1109{
51470298 1110 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1111
51470298 1112 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1113
ff3187f6 1114 st->pktin = ssh_new_packet();
1115
1116 st->pktin->type = 0;
1117 st->pktin->length = 0;
51470298 1118 if (ssh->sccipher)
1119 st->cipherblk = ssh->sccipher->blksize;
e5574168 1120 else
32874aea 1121 st->cipherblk = 8;
960e736a 1122 if (st->cipherblk < 8)
32874aea 1123 st->cipherblk = 8;
960e736a 1124
ff3187f6 1125 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1126
1127 /*
1128 * Acquire and decrypt the first block of the packet. This will
1129 * contain the length and padding details.
1130 */
32874aea 1131 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1132 while ((*datalen) == 0)
ff3187f6 1133 crReturn(NULL);
1134 st->pktin->data[st->i] = *(*data)++;
32874aea 1135 (*datalen)--;
e5574168 1136 }
4252c9cc 1137
51470298 1138 if (ssh->sccipher)
371e569c 1139 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1140 st->pktin->data, st->cipherblk);
e5574168 1141
1142 /*
1143 * Now get the length and padding figures.
1144 */
ff3187f6 1145 st->len = GET_32BIT(st->pktin->data);
1146 st->pad = st->pktin->data[4];
e5574168 1147
1148 /*
717dc483 1149 * _Completely_ silly lengths should be stomped on before they
1150 * do us any more damage.
1151 */
1152 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1153 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1154 ssh_free_packet(st->pktin);
1155 crStop(NULL);
717dc483 1156 }
1157
1158 /*
e5574168 1159 * This enables us to deduce the payload length.
1160 */
960e736a 1161 st->payload = st->len - st->pad - 1;
e5574168 1162
ff3187f6 1163 st->pktin->length = st->payload + 5;
e5574168 1164
1165 /*
1166 * So now we can work out the total packet length.
1167 */
960e736a 1168 st->packetlen = st->len + 4;
51470298 1169 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1170
1171 /*
ff3187f6 1172 * Allocate memory for the rest of the packet.
e5574168 1173 */
ff3187f6 1174 st->pktin->maxlen = st->packetlen + st->maclen;
1175 st->pktin->data = sresize(st->pktin->data,
1176 st->pktin->maxlen + APIEXTRA,
1177 unsigned char);
e5574168 1178
1179 /*
1180 * Read and decrypt the remainder of the packet.
1181 */
32874aea 1182 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1183 st->i++) {
e5574168 1184 while ((*datalen) == 0)
ff3187f6 1185 crReturn(NULL);
1186 st->pktin->data[st->i] = *(*data)++;
32874aea 1187 (*datalen)--;
e5574168 1188 }
1189 /* Decrypt everything _except_ the MAC. */
51470298 1190 if (ssh->sccipher)
371e569c 1191 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1192 st->pktin->data + st->cipherblk,
51470298 1193 st->packetlen - st->cipherblk);
e5574168 1194
9442dd57 1195 st->pktin->encrypted_len = st->packetlen;
1196
e5574168 1197 /*
1198 * Check the MAC.
1199 */
51470298 1200 if (ssh->scmac
ff3187f6 1201 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1202 st->incoming_sequence)) {
6b5cf8b4 1203 bombout(("Incorrect MAC received on packet"));
ff3187f6 1204 ssh_free_packet(st->pktin);
1205 crStop(NULL);
8d5de777 1206 }
b09eaa88 1207
1208 st->pktin->sequence = st->incoming_sequence++;
e5574168 1209
4ba9b64b 1210 /*
1211 * Decompress packet payload.
1212 */
1213 {
1214 unsigned char *newpayload;
1215 int newlen;
51470298 1216 if (ssh->sccomp &&
5366aed8 1217 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1218 st->pktin->data + 5, st->pktin->length - 5,
51470298 1219 &newpayload, &newlen)) {
ff3187f6 1220 if (st->pktin->maxlen < newlen + 5) {
1221 st->pktin->maxlen = newlen + 5;
1222 st->pktin->data = sresize(st->pktin->data,
1223 st->pktin->maxlen + APIEXTRA,
3d88e64d 1224 unsigned char);
4ba9b64b 1225 }
ff3187f6 1226 st->pktin->length = 5 + newlen;
1227 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1228 sfree(newpayload);
4ba9b64b 1229 }
1230 }
1231
ff3187f6 1232 st->pktin->savedpos = 6;
1233 st->pktin->body = st->pktin->data;
1234 st->pktin->type = st->pktin->data[5];
e5574168 1235
9a10ecf4 1236 /*
1237 * Log incoming packet, possibly omitting sensitive fields.
1238 */
1239 if (ssh->logctx) {
1240 int nblanks = 0;
1241 struct logblank_t blank;
1242 if (ssh->cfg.logomitdata) {
1243 int do_blank = FALSE, blank_prefix = 0;
1244 /* "Session data" packets - omit the data field */
ff3187f6 1245 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1246 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1247 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1248 do_blank = TRUE; blank_prefix = 8;
1249 }
1250 if (do_blank) {
1251 blank.offset = blank_prefix;
ff3187f6 1252 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1253 blank.type = PKTLOG_OMIT;
1254 nblanks = 1;
1255 }
1256 }
ff3187f6 1257 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1258 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1259 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1260 nblanks, &blank);
1261 }
00db133f 1262
ff3187f6 1263 crFinish(st->pktin);
e5574168 1264}
1265
ff3187f6 1266static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1267{
374330e2 1268 int pad, biglen;
1269
1270 len += 5; /* type and CRC */
32874aea 1271 pad = 8 - (len % 8);
374330e2 1272 biglen = len + pad;
1273
ff3187f6 1274 pkt->length = len - 5;
1275 if (pkt->maxlen < biglen) {
1276 pkt->maxlen = biglen;
1277 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1278 }
ff3187f6 1279 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1280}
374330e2 1281
ff3187f6 1282static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1283{
ff3187f6 1284 struct Packet *pkt = ssh_new_packet();
1285 ssh1_pktout_size(pkt, len);
1286 pkt->type = type;
9a10ecf4 1287 /* Initialise log omission state */
ff3187f6 1288 pkt->nblanks = 0;
1289 pkt->blanks = NULL;
1290 return pkt;
374330e2 1291}
1292
ff3187f6 1293static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1294{
fd7a4aad 1295 int pad, biglen, i;
374330e2 1296 unsigned long crc;
fd7a4aad 1297#ifdef __SC__
1298 /*
1299 * XXX various versions of SC (including 8.8.4) screw up the
1300 * register allocation in this function and use the same register
1301 * (D6) for len and as a temporary, with predictable results. The
1302 * following sledgehammer prevents this.
1303 */
1304 volatile
1305#endif
1306 int len;
374330e2 1307
ff3187f6 1308 pkt->body[-1] = pkt->type;
4ba9b64b 1309
a8327734 1310 if (ssh->logctx)
ff3187f6 1311 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1312 ssh1_pkt_type(pkt->type),
1313 pkt->body, pkt->length,
1314 pkt->nblanks, pkt->blanks);
1315 sfree(pkt->blanks); pkt->blanks = NULL;
1316 pkt->nblanks = 0;
00db133f 1317
51470298 1318 if (ssh->v1_compressing) {
4ba9b64b 1319 unsigned char *compblk;
1320 int complen;
5366aed8 1321 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1322 pkt->body - 1, pkt->length + 1,
4ba9b64b 1323 &compblk, &complen);
ff3187f6 1324 ssh1_pktout_size(pkt, complen - 1);
1325 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1326 sfree(compblk);
4ba9b64b 1327 }
1328
ff3187f6 1329 len = pkt->length + 5; /* type and CRC */
32874aea 1330 pad = 8 - (len % 8);
374330e2 1331 biglen = len + pad;
1332
32874aea 1333 for (i = 0; i < pad; i++)
ff3187f6 1334 pkt->data[i + 4] = random_byte();
1335 crc = crc32_compute(pkt->data + 4, biglen - 4);
1336 PUT_32BIT(pkt->data + biglen, crc);
1337 PUT_32BIT(pkt->data, len);
374330e2 1338
51470298 1339 if (ssh->cipher)
ff3187f6 1340 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1341
32874aea 1342 return biglen + 4;
39065bed 1343}
1344
ff3187f6 1345static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1346{
5471d09a 1347 int len, backlog;
ff3187f6 1348 len = s_wrpkt_prepare(ssh, pkt);
1349 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1350 if (backlog > SSH_MAX_BACKLOG)
51470298 1351 ssh_throttle_all(ssh, 1, backlog);
39065bed 1352}
1353
ff3187f6 1354static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1355{
39065bed 1356 int len;
ff3187f6 1357 len = s_wrpkt_prepare(ssh, pkt);
51470298 1358 if (ssh->deferred_len + len > ssh->deferred_size) {
1359 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1360 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1361 ssh->deferred_size,
1362 unsigned char);
39065bed 1363 }
ff3187f6 1364 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1365 ssh->deferred_len += len;
374330e2 1366}
1367
fb09bf1c 1368/*
39065bed 1369 * Construct a packet with the specified contents.
fb09bf1c 1370 */
ff3187f6 1371static struct Packet *construct_packet(Ssh ssh, int pkttype,
1372 va_list ap1, va_list ap2)
fb09bf1c 1373{
fb09bf1c 1374 unsigned char *p, *argp, argchar;
1375 unsigned long argint;
1376 int pktlen, argtype, arglen;
7cca0d81 1377 Bignum bn;
ff3187f6 1378 struct Packet *pkt;
fb09bf1c 1379
1380 pktlen = 0;
39065bed 1381 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1382 switch (argtype) {
1383 case PKT_INT:
39065bed 1384 (void) va_arg(ap1, int);
fb09bf1c 1385 pktlen += 4;
1386 break;
1387 case PKT_CHAR:
1ec39246 1388 (void) va_arg(ap1, int);
fb09bf1c 1389 pktlen++;
1390 break;
1391 case PKT_DATA:
39065bed 1392 (void) va_arg(ap1, unsigned char *);
1393 arglen = va_arg(ap1, int);
fb09bf1c 1394 pktlen += arglen;
1395 break;
1396 case PKT_STR:
39065bed 1397 argp = va_arg(ap1, unsigned char *);
d8baa528 1398 arglen = strlen((char *)argp);
fb09bf1c 1399 pktlen += 4 + arglen;
1400 break;
7cca0d81 1401 case PKT_BIGNUM:
39065bed 1402 bn = va_arg(ap1, Bignum);
32874aea 1403 pktlen += ssh1_bignum_length(bn);
7cca0d81 1404 break;
9a10ecf4 1405 case PKTT_PASSWORD:
1406 case PKTT_DATA:
1407 case PKTT_OTHER:
1408 /* ignore this pass */
1409 break;
fb09bf1c 1410 default:
1411 assert(0);
1412 }
1413 }
fb09bf1c 1414
ff3187f6 1415 pkt = s_wrpkt_start(pkttype, pktlen);
1416 p = pkt->body;
fb09bf1c 1417
39065bed 1418 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1419 int offset = p - pkt->body, len = 0;
fb09bf1c 1420 switch (argtype) {
9a10ecf4 1421 /* Actual fields in the packet */
fb09bf1c 1422 case PKT_INT:
39065bed 1423 argint = va_arg(ap2, int);
fb09bf1c 1424 PUT_32BIT(p, argint);
9a10ecf4 1425 len = 4;
fb09bf1c 1426 break;
1427 case PKT_CHAR:
1ec39246 1428 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1429 *p = argchar;
9a10ecf4 1430 len = 1;
fb09bf1c 1431 break;
1432 case PKT_DATA:
39065bed 1433 argp = va_arg(ap2, unsigned char *);
1434 arglen = va_arg(ap2, int);
fb09bf1c 1435 memcpy(p, argp, arglen);
9a10ecf4 1436 len = arglen;
fb09bf1c 1437 break;
1438 case PKT_STR:
39065bed 1439 argp = va_arg(ap2, unsigned char *);
d8baa528 1440 arglen = strlen((char *)argp);
fb09bf1c 1441 PUT_32BIT(p, arglen);
1442 memcpy(p + 4, argp, arglen);
9a10ecf4 1443 len = arglen + 4;
fb09bf1c 1444 break;
7cca0d81 1445 case PKT_BIGNUM:
39065bed 1446 bn = va_arg(ap2, Bignum);
9a10ecf4 1447 len = ssh1_write_bignum(p, bn);
1448 break;
1449 /* Tokens for modifications to packet logging */
1450 case PKTT_PASSWORD:
ff3187f6 1451 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1452 break;
1453 case PKTT_DATA:
ff3187f6 1454 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1455 break;
9a10ecf4 1456 case PKTT_OTHER:
ff3187f6 1457 end_log_omission(ssh, pkt);
9a10ecf4 1458 break;
1459 }
1460 p += len;
1461 /* Deal with logfile omission, if required. */
ff3187f6 1462 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1463 pkt->nblanks++;
1464 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1465 struct logblank_t);
1466 pkt->blanks[pkt->nblanks-1].offset = offset;
1467 pkt->blanks[pkt->nblanks-1].len = len;
1468 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1469 }
1470 }
ff3187f6 1471
1472 return pkt;
39065bed 1473}
fb09bf1c 1474
51470298 1475static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1476{
ff3187f6 1477 struct Packet *pkt;
39065bed 1478 va_list ap1, ap2;
1479 va_start(ap1, pkttype);
1480 va_start(ap2, pkttype);
ff3187f6 1481 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1482 va_end(ap2);
1483 va_end(ap1);
1484 s_wrpkt(ssh, pkt);
1485 ssh_free_packet(pkt);
fb09bf1c 1486}
1487
51470298 1488static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1489{
ff3187f6 1490 struct Packet *pkt;
39065bed 1491 va_list ap1, ap2;
1492 va_start(ap1, pkttype);
1493 va_start(ap2, pkttype);
ff3187f6 1494 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1495 va_end(ap2);
1496 va_end(ap1);
1497 s_wrpkt_defer(ssh, pkt);
1498 ssh_free_packet(pkt);
39065bed 1499}
1500
32874aea 1501static int ssh_versioncmp(char *a, char *b)
1502{
9697bfd2 1503 char *ae, *be;
1504 unsigned long av, bv;
1505
43aa02a7 1506 av = strtoul(a, &ae, 10);
1507 bv = strtoul(b, &be, 10);
32874aea 1508 if (av != bv)
1509 return (av < bv ? -1 : +1);
1510 if (*ae == '.')
1511 ae++;
1512 if (*be == '.')
1513 be++;
43aa02a7 1514 av = strtoul(ae, &ae, 10);
1515 bv = strtoul(be, &be, 10);
32874aea 1516 if (av != bv)
1517 return (av < bv ? -1 : +1);
9697bfd2 1518 return 0;
1519}
1520
e5574168 1521/*
a92dd380 1522 * Utility routines for putting an SSH-protocol `string' and
1523 * `uint32' into a SHA state.
e5574168 1524 */
1525#include <stdio.h>
32874aea 1526static void sha_string(SHA_State * s, void *str, int len)
1527{
e5574168 1528 unsigned char lenblk[4];
e5574168 1529 PUT_32BIT(lenblk, len);
e5574168 1530 SHA_Bytes(s, lenblk, 4);
e5574168 1531 SHA_Bytes(s, str, len);
1532}
1533
32874aea 1534static void sha_uint32(SHA_State * s, unsigned i)
1535{
a92dd380 1536 unsigned char intblk[4];
1537 PUT_32BIT(intblk, i);
1538 SHA_Bytes(s, intblk, 4);
1539}
1540
7cca0d81 1541/*
1542 * SSH2 packet construction functions.
1543 */
ff3187f6 1544static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1545{
ff3187f6 1546 if (pkt->maxlen < length) {
1547 pkt->maxlen = length + 256;
1548 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1549 }
783415f8 1550}
ff3187f6 1551static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1552{
ff3187f6 1553 if (pkt->logmode != PKTLOG_EMIT) {
1554 pkt->nblanks++;
1555 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1556 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1557 pkt->blanks[pkt->nblanks-1].len = len;
1558 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1559 }
1560 pkt->length += len;
1561 ssh2_pkt_ensure(pkt, pkt->length);
1562 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1563}
ff3187f6 1564static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1565{
ff3187f6 1566 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1567}
ff3187f6 1568static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1569{
ff3187f6 1570 struct Packet *pkt = ssh_new_packet();
1571 pkt->length = 5;
1572 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1573 return pkt;
7cca0d81 1574}
ff3187f6 1575static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1576{
ff3187f6 1577 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1578}
ff3187f6 1579static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1580{
7cca0d81 1581 unsigned char x[4];
1582 PUT_32BIT(x, value);
ff3187f6 1583 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1584}
ff3187f6 1585static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1586{
ff3187f6 1587 ssh2_pkt_adduint32(pkt, 0);
1588 pkt->savedpos = pkt->length;
7cca0d81 1589}
ff3187f6 1590static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1591{
ff3187f6 1592 ssh2_pkt_adddata(pkt, data, strlen(data));
1593 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1594}
ff3187f6 1595static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1596{
ff3187f6 1597 ssh2_pkt_adddata(pkt, data, len);
1598 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1599}
ff3187f6 1600static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1601{
ff3187f6 1602 ssh2_pkt_addstring_start(pkt);
1603 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1604}
d8baa528 1605static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1606{
7cca0d81 1607 unsigned char *p;
32874aea 1608 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1609 p = snewn(n + 1, unsigned char);
7cca0d81 1610 if (!p)
32874aea 1611 fatalbox("out of memory");
7cca0d81 1612 p[0] = 0;
3709bfe9 1613 for (i = 1; i <= n; i++)
32874aea 1614 p[i] = bignum_byte(b, n - i);
7cca0d81 1615 i = 0;
32874aea 1616 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1617 i++;
1618 memmove(p, p + i, n + 1 - i);
1619 *len = n + 1 - i;
7cca0d81 1620 return p;
1621}
ff3187f6 1622static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1623{
7cca0d81 1624 unsigned char *p;
1625 int len;
1626 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1627 ssh2_pkt_addstring_start(pkt);
1628 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1629 sfree(p);
7cca0d81 1630}
b185170a 1631
1632/*
1633 * Construct an SSH2 final-form packet: compress it, encrypt it,
1634 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1635 * pkt->data. Total length is returned.
b185170a 1636 */
ff3187f6 1637static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1638{
7cca0d81 1639 int cipherblk, maclen, padding, i;
7cca0d81 1640
a8327734 1641 if (ssh->logctx)
ff3187f6 1642 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1643 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1644 pkt->data + 6, pkt->length - 6,
1645 pkt->nblanks, pkt->blanks);
1646 sfree(pkt->blanks); pkt->blanks = NULL;
1647 pkt->nblanks = 0;
00db133f 1648
7cca0d81 1649 /*
4ba9b64b 1650 * Compress packet payload.
1651 */
4ba9b64b 1652 {
1653 unsigned char *newpayload;
1654 int newlen;
51470298 1655 if (ssh->cscomp &&
ff3187f6 1656 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1657 pkt->length - 5,
51470298 1658 &newpayload, &newlen)) {
ff3187f6 1659 pkt->length = 5;
1660 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1661 sfree(newpayload);
4ba9b64b 1662 }
1663 }
1664
1665 /*
7cca0d81 1666 * Add padding. At least four bytes, and must also bring total
1667 * length (minus MAC) up to a multiple of the block size.
1668 */
51470298 1669 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1670 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1671 padding = 4;
32874aea 1672 padding +=
ff3187f6 1673 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1674 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1675 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1676 pkt->data[4] = padding;
7cca0d81 1677 for (i = 0; i < padding; i++)
ff3187f6 1678 pkt->data[pkt->length + i] = random_byte();
1679 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1680 if (ssh->csmac)
ff3187f6 1681 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1682 pkt->length + padding,
51470298 1683 ssh->v2_outgoing_sequence);
1684 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1685
1686 if (ssh->cscipher)
371e569c 1687 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1688 pkt->data, pkt->length + padding);
51470298 1689
9442dd57 1690 pkt->encrypted_len = pkt->length + padding;
1691
ff3187f6 1692 /* Ready-to-send packet starts at pkt->data. We return length. */
1693 return pkt->length + padding + maclen;
b185170a 1694}
1695
1696/*
590f6a5f 1697 * Routines called from the main SSH code to send packets. There
1698 * are quite a few of these, because we have two separate
1699 * mechanisms for delaying the sending of packets:
1700 *
1701 * - In order to send an IGNORE message and a password message in
1702 * a single fixed-length blob, we require the ability to
1703 * concatenate the encrypted forms of those two packets _into_ a
1704 * single blob and then pass it to our <network.h> transport
1705 * layer in one go. Hence, there's a deferment mechanism which
1706 * works after packet encryption.
1707 *
1708 * - In order to avoid sending any connection-layer messages
1709 * during repeat key exchange, we have to queue up any such
1710 * outgoing messages _before_ they are encrypted (and in
1711 * particular before they're allocated sequence numbers), and
1712 * then send them once we've finished.
1713 *
1714 * I call these mechanisms `defer' and `queue' respectively, so as
1715 * to distinguish them reasonably easily.
1716 *
1717 * The functions send_noqueue() and defer_noqueue() free the packet
1718 * structure they are passed. Every outgoing packet goes through
1719 * precisely one of these functions in its life; packets passed to
1720 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1721 * these or get queued, and then when the queue is later emptied
1722 * the packets are all passed to defer_noqueue().
b185170a 1723 */
590f6a5f 1724
1725/*
1726 * Send an SSH2 packet immediately, without queuing or deferring.
1727 */
1728static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1729{
5471d09a 1730 int len;
1731 int backlog;
ff3187f6 1732 len = ssh2_pkt_construct(ssh, pkt);
1733 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1734 if (backlog > SSH_MAX_BACKLOG)
51470298 1735 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1736
1737 ssh->outgoing_data_size += pkt->encrypted_len;
1738 if (!ssh->kex_in_progress &&
d57f70af 1739 ssh->max_data_size != 0 &&
1740 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1741 do_ssh2_transport(ssh, "Initiating key re-exchange "
1742 "(too much data sent)", -1, NULL);
1743
ff3187f6 1744 ssh_free_packet(pkt);
b185170a 1745}
1746
1747/*
590f6a5f 1748 * Defer an SSH2 packet.
b185170a 1749 */
590f6a5f 1750static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1751{
ff3187f6 1752 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1753 if (ssh->deferred_len + len > ssh->deferred_size) {
1754 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1755 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1756 ssh->deferred_size,
1757 unsigned char);
b185170a 1758 }
ff3187f6 1759 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1760 ssh->deferred_len += len;
9442dd57 1761 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1762 ssh_free_packet(pkt);
b185170a 1763}
1764
1765/*
590f6a5f 1766 * Queue an SSH2 packet.
1767 */
1768static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1769{
1770 assert(ssh->queueing);
1771
1772 if (ssh->queuelen >= ssh->queuesize) {
1773 ssh->queuesize = ssh->queuelen + 32;
1774 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1775 }
1776
1777 ssh->queue[ssh->queuelen++] = pkt;
1778}
1779
1780/*
1781 * Either queue or send a packet, depending on whether queueing is
1782 * set.
1783 */
1784static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1785{
1786 if (ssh->queueing)
1787 ssh2_pkt_queue(ssh, pkt);
1788 else
1789 ssh2_pkt_send_noqueue(ssh, pkt);
1790}
1791
1792/*
1793 * Either queue or defer a packet, depending on whether queueing is
1794 * set.
1795 */
1796static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1797{
1798 if (ssh->queueing)
1799 ssh2_pkt_queue(ssh, pkt);
1800 else
1801 ssh2_pkt_defer_noqueue(ssh, pkt);
1802}
1803
1804/*
b185170a 1805 * Send the whole deferred data block constructed by
39065bed 1806 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1807 *
1808 * The expected use of the defer mechanism is that you call
1809 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1810 * not currently queueing, this simply sets up deferred_send_data
1811 * and then sends it. If we _are_ currently queueing, the calls to
1812 * ssh2_pkt_defer() put the deferred packets on to the queue
1813 * instead, and therefore ssh_pkt_defersend() has no deferred data
1814 * to send. Hence, there's no need to make it conditional on
1815 * ssh->queueing.
b185170a 1816 */
51470298 1817static void ssh_pkt_defersend(Ssh ssh)
32874aea 1818{
5471d09a 1819 int backlog;
d8baa528 1820 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1821 ssh->deferred_len);
51470298 1822 ssh->deferred_len = ssh->deferred_size = 0;
1823 sfree(ssh->deferred_send_data);
1824 ssh->deferred_send_data = NULL;
5471d09a 1825 if (backlog > SSH_MAX_BACKLOG)
51470298 1826 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1827
1828 ssh->outgoing_data_size += ssh->deferred_data_size;
1829 if (!ssh->kex_in_progress &&
d57f70af 1830 ssh->max_data_size != 0 &&
1831 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1832 do_ssh2_transport(ssh, "Initiating key re-exchange "
1833 "(too much data sent)", -1, NULL);
1834 ssh->deferred_data_size = 0;
7cca0d81 1835}
1836
590f6a5f 1837/*
1838 * Send all queued SSH2 packets. We send them by means of
1839 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1840 * packets that needed to be lumped together.
1841 */
1842static void ssh2_pkt_queuesend(Ssh ssh)
1843{
1844 int i;
1845
1846 assert(!ssh->queueing);
1847
1848 for (i = 0; i < ssh->queuelen; i++)
1849 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1850 ssh->queuelen = 0;
1851
1852 ssh_pkt_defersend(ssh);
1853}
1854
7cca0d81 1855#if 0
32874aea 1856void bndebug(char *string, Bignum b)
1857{
7cca0d81 1858 unsigned char *p;
1859 int i, len;
1860 p = ssh2_mpint_fmt(b, &len);
1861 debug(("%s", string));
1862 for (i = 0; i < len; i++)
32874aea 1863 debug((" %02x", p[i]));
765c4200 1864 debug(("\n"));
dcbde236 1865 sfree(p);
7cca0d81 1866}
1867#endif
1868
32874aea 1869static void sha_mpint(SHA_State * s, Bignum b)
1870{
7cca0d81 1871 unsigned char *p;
1872 int len;
1873 p = ssh2_mpint_fmt(b, &len);
1874 sha_string(s, p, len);
dcbde236 1875 sfree(p);
7cca0d81 1876}
1877
1878/*
0016d70b 1879 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1880 */
ff3187f6 1881static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1882{
7cca0d81 1883 unsigned long value;
ff3187f6 1884 if (pkt->length - pkt->savedpos < 4)
32874aea 1885 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1886 value = GET_32BIT(pkt->body + pkt->savedpos);
1887 pkt->savedpos += 4;
7cca0d81 1888 return value;
1889}
ff3187f6 1890static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1891{
65a22376 1892 unsigned long value;
ff3187f6 1893 if (pkt->length - pkt->savedpos < 1)
32874aea 1894 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1895 value = pkt->body[pkt->savedpos] != 0;
1896 pkt->savedpos++;
65a22376 1897 return value;
1898}
ff3187f6 1899static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1900{
57356d63 1901 int len;
7cca0d81 1902 *p = NULL;
45068b27 1903 *length = 0;
ff3187f6 1904 if (pkt->length - pkt->savedpos < 4)
32874aea 1905 return;
ff3187f6 1906 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1907 if (len < 0)
1908 return;
1909 *length = len;
ff3187f6 1910 pkt->savedpos += 4;
1911 if (pkt->length - pkt->savedpos < *length)
32874aea 1912 return;
ff3187f6 1913 *p = (char *)(pkt->body + pkt->savedpos);
1914 pkt->savedpos += *length;
7cca0d81 1915}
ff3187f6 1916static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1917{
ff3187f6 1918 if (pkt->length - pkt->savedpos < length)
0016d70b 1919 return NULL;
ff3187f6 1920 pkt->savedpos += length;
1921 return pkt->body + (pkt->savedpos - length);
0016d70b 1922}
ff3187f6 1923static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1924 unsigned char **keystr)
1925{
1926 int j;
1927
ff3187f6 1928 j = makekey(pkt->body + pkt->savedpos,
1929 pkt->length - pkt->savedpos,
0016d70b 1930 key, keystr, 0);
1931
1932 if (j < 0)
1933 return FALSE;
1934
ff3187f6 1935 pkt->savedpos += j;
1936 assert(pkt->savedpos < pkt->length);
0016d70b 1937
1938 return TRUE;
1939}
ff3187f6 1940static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1941{
1942 int j;
1943 Bignum b;
1944
ff3187f6 1945 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1946 pkt->length - pkt->savedpos, &b);
0016d70b 1947
1948 if (j < 0)
1949 return NULL;
1950
ff3187f6 1951 pkt->savedpos += j;
0016d70b 1952 return b;
1953}
ff3187f6 1954static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1955{
7cca0d81 1956 char *p;
3709bfe9 1957 int length;
7cca0d81 1958 Bignum b;
1959
ff3187f6 1960 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1961 if (!p)
32874aea 1962 return NULL;
ff3187f6 1963 if (p[0] & 0x80)
32874aea 1964 return NULL;
d8baa528 1965 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1966 return b;
1967}
1968
7d503c31 1969/*
1dd353b5 1970 * Helper function to add an SSH2 signature blob to a packet.
1971 * Expects to be shown the public key blob as well as the signature
1972 * blob. Normally works just like ssh2_pkt_addstring, but will
1973 * fiddle with the signature packet if necessary for
1974 * BUG_SSH2_RSA_PADDING.
1975 */
ff3187f6 1976static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1977 void *pkblob_v, int pkblob_len,
1dd353b5 1978 void *sigblob_v, int sigblob_len)
1979{
1980 unsigned char *pkblob = (unsigned char *)pkblob_v;
1981 unsigned char *sigblob = (unsigned char *)sigblob_v;
1982
1983 /* dmemdump(pkblob, pkblob_len); */
1984 /* dmemdump(sigblob, sigblob_len); */
1985
1986 /*
1987 * See if this is in fact an ssh-rsa signature and a buggy
1988 * server; otherwise we can just do this the easy way.
1989 */
51470298 1990 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1991 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1992 int pos, len, siglen;
1993
1994 /*
1995 * Find the byte length of the modulus.
1996 */
1997
1998 pos = 4+7; /* skip over "ssh-rsa" */
1999 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2000 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2001 pos += 4; /* find modulus itself */
2002 while (len > 0 && pkblob[pos] == 0)
2003 len--, pos++;
2004 /* debug(("modulus length is %d\n", len)); */
2005
2006 /*
2007 * Now find the signature integer.
2008 */
2009 pos = 4+7; /* skip over "ssh-rsa" */
2010 siglen = GET_32BIT(sigblob+pos);
2011 /* debug(("signature length is %d\n", siglen)); */
2012
2013 if (len != siglen) {
2014 unsigned char newlen[4];
ff3187f6 2015 ssh2_pkt_addstring_start(pkt);
2016 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2017 /* dmemdump(sigblob, pos); */
2018 pos += 4; /* point to start of actual sig */
2019 PUT_32BIT(newlen, len);
ff3187f6 2020 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2021 /* dmemdump(newlen, 4); */
2022 newlen[0] = 0;
2023 while (len-- > siglen) {
ff3187f6 2024 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2025 /* dmemdump(newlen, 1); */
2026 }
ff3187f6 2027 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2028 /* dmemdump(sigblob+pos, siglen); */
2029 return;
2030 }
2031
2032 /* Otherwise fall through and do it the easy way. */
2033 }
2034
ff3187f6 2035 ssh2_pkt_addstring_start(pkt);
2036 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2037}
2038
2039/*
7d503c31 2040 * Examine the remote side's version string and compare it against
2041 * a list of known buggy implementations.
2042 */
51470298 2043static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2044{
2045 char *imp; /* pointer to implementation part */
7d503c31 2046 imp = vstring;
2047 imp += strcspn(imp, "-");
bd358db1 2048 if (*imp) imp++;
7d503c31 2049 imp += strcspn(imp, "-");
bd358db1 2050 if (*imp) imp++;
7d503c31 2051
51470298 2052 ssh->remote_bugs = 0;
7d503c31 2053
5ecd7ad0 2054 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2055 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2056 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2057 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2058 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2059 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2060 /*
2061 * These versions don't support SSH1_MSG_IGNORE, so we have
2062 * to use a different defence against password length
2063 * sniffing.
2064 */
51470298 2065 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2066 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2067 }
2068
5ecd7ad0 2069 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2070 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2071 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2072 /*
2073 * These versions need a plain password sent; they can't
2074 * handle having a null and a random length of data after
2075 * the password.
2076 */
51470298 2077 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2078 logevent("We believe remote version needs a plain SSH1 password");
2079 }
2080
5ecd7ad0 2081 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2082 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2083 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2084 /*
2085 * These versions apparently have no clue whatever about
2086 * RSA authentication and will panic and die if they see
2087 * an AUTH_RSA message.
2088 */
51470298 2089 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2090 logevent("We believe remote version can't handle RSA authentication");
2091 }
2092
5ecd7ad0 2093 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2094 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2095 !wc_match("* VShell", imp) &&
831301f6 2096 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2097 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2098 wc_match("2.1 *", imp)))) {
32874aea 2099 /*
2100 * These versions have the HMAC bug.
2101 */
51470298 2102 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2103 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2104 }
1dd353b5 2105
5ecd7ad0 2106 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2107 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2108 !wc_match("* VShell", imp) &&
2856a1b9 2109 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2110 /*
2111 * These versions have the key-derivation bug (failing to
2112 * include the literal shared secret in the hashes that
2113 * generate the keys).
2114 */
51470298 2115 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2116 logevent("We believe remote version has SSH2 key-derivation bug");
2117 }
2118
5ecd7ad0 2119 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2120 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2121 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2122 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2123 /*
2124 * These versions have the SSH2 RSA padding bug.
2125 */
51470298 2126 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2127 logevent("We believe remote version has SSH2 RSA padding bug");
2128 }
8e975795 2129
dda87a28 2130 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2131 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2132 wc_match("OpenSSH_2.[0-2]*", imp))) {
2133 /*
2134 * These versions have the SSH2 session-ID bug in
2135 * public-key authentication.
2136 */
2137 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2138 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2139 }
7d503c31 2140}
2141
d38d6a1f 2142/*
2143 * The `software version' part of an SSH version string is required
2144 * to contain no spaces or minus signs.
2145 */
2146static void ssh_fix_verstring(char *str)
2147{
2148 /* Eat "SSH-<protoversion>-". */
2149 assert(*str == 'S'); str++;
2150 assert(*str == 'S'); str++;
2151 assert(*str == 'H'); str++;
2152 assert(*str == '-'); str++;
2153 while (*str && *str != '-') str++;
2154 assert(*str == '-'); str++;
2155
2156 /* Convert minus signs and spaces in the remaining string into
2157 * underscores. */
2158 while (*str) {
2159 if (*str == '-' || *str == ' ')
2160 *str = '_';
2161 str++;
2162 }
2163}
2164
51470298 2165static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2166{
51470298 2167 struct do_ssh_init_state {
2168 int vslen;
2169 char version[10];
2170 char *vstring;
2171 int vstrsize;
2172 int i;
2173 int proto1, proto2;
2174 };
2175 crState(do_ssh_init_state);
374330e2 2176
51470298 2177 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2178
2179 /* Search for the string "SSH-" in the input. */
51470298 2180 s->i = 0;
8df7a775 2181 while (1) {
2182 static const int transS[] = { 1, 2, 2, 1 };
2183 static const int transH[] = { 0, 0, 3, 0 };
2184 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2185 if (c == 'S')
51470298 2186 s->i = transS[s->i];
32874aea 2187 else if (c == 'H')
51470298 2188 s->i = transH[s->i];
32874aea 2189 else if (c == '-')
51470298 2190 s->i = transminus[s->i];
32874aea 2191 else
51470298 2192 s->i = 0;
2193 if (s->i < 0)
8df7a775 2194 break;
2195 crReturn(1); /* get another character */
374330e2 2196 }
8df7a775 2197
51470298 2198 s->vstrsize = 16;
3d88e64d 2199 s->vstring = snewn(s->vstrsize, char);
51470298 2200 strcpy(s->vstring, "SSH-");
2201 s->vslen = 4;
2202 s->i = 0;
374330e2 2203 while (1) {
8df7a775 2204 crReturn(1); /* get another char */
51470298 2205 if (s->vslen >= s->vstrsize - 1) {
2206 s->vstrsize += 16;
3d88e64d 2207 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2208 }
51470298 2209 s->vstring[s->vslen++] = c;
2210 if (s->i >= 0) {
374330e2 2211 if (c == '-') {
51470298 2212 s->version[s->i] = '\0';
2213 s->i = -1;
2214 } else if (s->i < sizeof(s->version) - 1)
2215 s->version[s->i++] = c;
c4ffc4d0 2216 } else if (c == '\012')
374330e2 2217 break;
2218 }
2219
51470298 2220 ssh->agentfwd_enabled = FALSE;
2221 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2222
51470298 2223 s->vstring[s->vslen] = 0;
a7d4653a 2224 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2225 {
2226 char *vlog;
3d88e64d 2227 vlog = snewn(20 + s->vslen, char);
51470298 2228 sprintf(vlog, "Server version: %s", s->vstring);
2229 logevent(vlog);
2230 sfree(vlog);
2231 }
2232 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2233
adf799dd 2234 /*
38d228a2 2235 * Decide which SSH protocol version to support.
adf799dd 2236 */
38d228a2 2237
2238 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2239 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2240 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2241 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2242
86916870 2243 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2244 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2245 crStop(0);
38d228a2 2246 }
86916870 2247 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2248 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2249 crStop(0);
38d228a2 2250 }
2251
d38d6a1f 2252 {
2253 char *verstring;
2254
2255 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2256 /*
2257 * Construct a v2 version string.
2258 */
a7d4653a 2259 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2260 ssh->version = 2;
2261 } else {
2262 /*
2263 * Construct a v1 version string.
2264 */
a7d4653a 2265 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2266 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2267 s->version : "1.5"),
2268 sshver);
2269 ssh->version = 1;
2270 }
2271
2272 ssh_fix_verstring(verstring);
2273
2274 if (ssh->version == 2) {
2275 /*
2276 * Hash our version string and their version string.
2277 */
2278 SHA_Init(&ssh->exhashbase);
0b351b6b 2279 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2280 strcspn(verstring, "\015\012"));
0b351b6b 2281 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2282 strcspn(s->vstring, "\015\012"));
d38d6a1f 2283
2284 /*
2285 * Initialise SSHv2 protocol.
2286 */
2287 ssh->protocol = ssh2_protocol;
2288 ssh2_protocol_setup(ssh);
2289 ssh->s_rdpkt = ssh2_rdpkt;
2290 } else {
2291 /*
2292 * Initialise SSHv1 protocol.
2293 */
2294 ssh->protocol = ssh1_protocol;
2295 ssh1_protocol_setup(ssh);
2296 ssh->s_rdpkt = ssh1_rdpkt;
2297 }
2298 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2299 strcspn(verstring, "\015\012"), verstring);
51470298 2300 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2301 sfree(verstring);
e5574168 2302 }
d38d6a1f 2303
2304 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2305
125105d1 2306 update_specials_menu(ssh->frontend);
51470298 2307 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2308 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2309
51470298 2310 sfree(s->vstring);
50526e47 2311
8df7a775 2312 crFinish(0);
2313}
2314
51470298 2315static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2316{
51470298 2317 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2318
2319 /*
2320 * To begin with, feed the characters one by one to the
2321 * protocol initialisation / selection function do_ssh_init().
2322 * When that returns 0, we're done with the initial greeting
2323 * exchange and can move on to packet discipline.
2324 */
2325 while (1) {
51470298 2326 int ret; /* need not be kept across crReturn */
8df7a775 2327 if (datalen == 0)
2328 crReturnV; /* more data please */
51470298 2329 ret = do_ssh_init(ssh, *data);
32874aea 2330 data++;
2331 datalen--;
8df7a775 2332 if (ret == 0)
2333 break;
2334 }
2335
2336 /*
2337 * We emerge from that loop when the initial negotiation is
2338 * over and we have selected an s_rdpkt function. Now pass
2339 * everything to s_rdpkt, and then pass the resulting packets
2340 * to the proper protocol handler.
2341 */
2342 if (datalen == 0)
2343 crReturnV;
2344 while (1) {
2345 while (datalen > 0) {
ff3187f6 2346 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2347 if (pktin) {
2348 ssh->protocol(ssh, NULL, 0, pktin);
2349 ssh_free_packet(pktin);
8df7a775 2350 }
ff3187f6 2351 if (ssh->state == SSH_STATE_CLOSED)
2352 return;
8df7a775 2353 }
2354 crReturnV;
2355 }
2356 crFinishV;
2357}
2358
36f94d1f 2359static void ssh_do_close(Ssh ssh)
32874aea 2360{
36f94d1f 2361 int i;
2362 struct ssh_channel *c;
2363
51470298 2364 ssh->state = SSH_STATE_CLOSED;
2365 if (ssh->s) {
2366 sk_close(ssh->s);
2367 ssh->s = NULL;
39934deb 2368 notify_remote_exit(ssh->frontend);
f3ab576e 2369 }
36f94d1f 2370 /*
2371 * Now we must shut down any port and X forwardings going
2372 * through this connection.
2373 */
74a98066 2374 if (ssh->channels) {
2375 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2376 switch (c->type) {
2377 case CHAN_X11:
2378 x11_close(c->u.x11.s);
2379 break;
2380 case CHAN_SOCKDATA:
2381 pfd_close(c->u.pfd.s);
2382 break;
2383 }
2384 del234(ssh->channels, c);
2385 if (ssh->version == 2)
2386 bufchain_clear(&c->v.v2.outbuffer);
2387 sfree(c);
36f94d1f 2388 }
36f94d1f 2389 }
2390}
2391
cbe2d68f 2392static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2393 int calling_back)
2394{
2395 Ssh ssh = (Ssh) plug;
2396 ssh_do_close(ssh);
7e78000d 2397 if (error_msg) {
32874aea 2398 /* A socket error has occurred. */
247308b5 2399 logevent(error_msg);
971bcc0a 2400 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2401 } else {
2402 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2403 }
7e78000d 2404 return 0;
2405}
2406
32874aea 2407static int ssh_receive(Plug plug, int urgent, char *data, int len)
2408{
51470298 2409 Ssh ssh = (Ssh) plug;
d8baa528 2410 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2411 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2412 ssh_do_close(ssh);
32874aea 2413 return 0;
3257deae 2414 }
fef97f43 2415 return 1;
374330e2 2416}
2417
5471d09a 2418static void ssh_sent(Plug plug, int bufsize)
2419{
51470298 2420 Ssh ssh = (Ssh) plug;
5471d09a 2421 /*
2422 * If the send backlog on the SSH socket itself clears, we
2423 * should unthrottle the whole world if it was throttled.
2424 */
2425 if (bufsize < SSH_MAX_BACKLOG)
51470298 2426 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2427}
2428
fb09bf1c 2429/*
8df7a775 2430 * Connect to specified host and port.
2431 * Returns an error message, or NULL on success.
6e1ebb76 2432 * Also places the canonical host name into `realhost'. It must be
2433 * freed by the caller.
8df7a775 2434 */
cbe2d68f 2435static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2436 char **realhost, int nodelay, int keepalive)
8df7a775 2437{
51470298 2438 static const struct plug_function_table fn_table = {
7e78000d 2439 ssh_closing,
5471d09a 2440 ssh_receive,
2441 ssh_sent,
2442 NULL
51470298 2443 };
7e78000d 2444
8df7a775 2445 SockAddr addr;
cbe2d68f 2446 const char *err;
8df7a775 2447
3d88e64d 2448 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2449 if (!ssh->savedhost)
8df7a775 2450 fatalbox("Out of memory");
51470298 2451 strcpy(ssh->savedhost, host);
8df7a775 2452
2453 if (port < 0)
2454 port = 22; /* default ssh port */
51470298 2455 ssh->savedport = port;
8df7a775 2456
2457 /*
2458 * Try to find host.
2459 */
05581745 2460 logeventf(ssh, "Looking up host \"%s\"%s", host,
2461 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2462 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2463 addr = name_lookup(host, port, realhost, &ssh->cfg,
2464 ssh->cfg.addressfamily);
170c1e6e 2465 if ((err = sk_addr_error(addr)) != NULL) {
2466 sk_addr_free(addr);
8df7a775 2467 return err;
170c1e6e 2468 }
8df7a775 2469
8df7a775 2470 /*
2471 * Open socket.
2472 */
3ad9d396 2473 {
57356d63 2474 char addrbuf[100];
3ad9d396 2475 sk_getaddr(addr, addrbuf, 100);
57356d63 2476 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2477 }
51470298 2478 ssh->fn = &fn_table;
e8fa8f62 2479 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2480 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2481 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2482 ssh->s = NULL;
39934deb 2483 notify_remote_exit(ssh->frontend);
8df7a775 2484 return err;
67c4ba2e 2485 }
8df7a775 2486
8df7a775 2487 return NULL;
2488}
2489
2490/*
5471d09a 2491 * Throttle or unthrottle the SSH connection.
2492 */
51470298 2493static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2494{
51470298 2495 int old_count = ssh->v1_throttle_count;
2496 ssh->v1_throttle_count += adjust;
2497 assert(ssh->v1_throttle_count >= 0);
2498 if (ssh->v1_throttle_count && !old_count) {
2499 sk_set_frozen(ssh->s, 1);
2500 } else if (!ssh->v1_throttle_count && old_count) {
2501 sk_set_frozen(ssh->s, 0);
5471d09a 2502 }
2503}
2504
2505/*
2506 * Throttle or unthrottle _all_ local data streams (for when sends
2507 * on the SSH connection itself back up).
2508 */
51470298 2509static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2510{
2511 int i;
2512 struct ssh_channel *c;
2513
51470298 2514 if (enable == ssh->throttled_all)
5471d09a 2515 return;
51470298 2516 ssh->throttled_all = enable;
2517 ssh->overall_bufsize = bufsize;
2518 if (!ssh->channels)
5471d09a 2519 return;
51470298 2520 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2521 switch (c->type) {
2522 case CHAN_MAINSESSION:
2523 /*
2524 * This is treated separately, outside the switch.
2525 */
2526 break;
2527 case CHAN_X11:
2528 x11_override_throttle(c->u.x11.s, enable);
2529 break;
2530 case CHAN_AGENT:
2531 /* Agent channels require no buffer management. */
2532 break;
2533 case CHAN_SOCKDATA:
36f94d1f 2534 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2535 break;
2536 }
2537 }
2538}
2539
2540/*
51470298 2541 * Username and password input, abstracted off into routines
2542 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2543 */
0405e71f 2544
2545/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2546static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2547{
51470298 2548 ssh->userpass_input_buffer = buffer;
2549 ssh->userpass_input_buflen = buflen;
2550 ssh->userpass_input_bufpos = 0;
2551 ssh->userpass_input_echo = echo;
0405e71f 2552}
2553
2554/*
2555 * Process some terminal data in the course of username/password
2556 * input. Returns >0 for success (line of input returned in
2557 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2558 * for inconclusive (keep waiting for more input please).
2559 */
ae9ae89f 2560static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2561{
2562 char c;
2563
2564 while (inlen--) {
2565 switch (c = *in++) {
2566 case 10:
2567 case 13:
51470298 2568 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2569 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2570 return +1;
2571 break;
2572 case 8:
2573 case 127:
51470298 2574 if (ssh->userpass_input_bufpos > 0) {
2575 if (ssh->userpass_input_echo)
2576 c_write_str(ssh, "\b \b");
2577 ssh->userpass_input_bufpos--;
0405e71f 2578 }
2579 break;
2580 case 21:
2581 case 27:
51470298 2582 while (ssh->userpass_input_bufpos > 0) {
2583 if (ssh->userpass_input_echo)
2584 c_write_str(ssh, "\b \b");
2585 ssh->userpass_input_bufpos--;
0405e71f 2586 }
2587 break;
2588 case 3:
2589 case 4:
2590 return -1;
2591 break;
2592 default:
4692a14a 2593 /*
2594 * This simplistic check for printability is disabled
2595 * when we're doing password input, because some people
2596 * have control characters in their passwords.o
2597 */
2598 if ((!ssh->userpass_input_echo ||
2599 (c >= ' ' && c <= '~') ||
0405e71f 2600 ((unsigned char) c >= 160))
51470298 2601 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2602 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2603 if (ssh->userpass_input_echo)
2604 c_write(ssh, &c, 1);
0405e71f 2605 }
2606 break;
2607 }
2608 }
2609 return 0;
2610}
2611
f11d78f2 2612static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2613{
2614 Ssh ssh = (Ssh) sshv;
2615
2616 ssh->agent_response = reply;
2617 ssh->agent_response_len = replylen;
2618
2619 if (ssh->version == 1)
ff3187f6 2620 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2621 else
ff3187f6 2622 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2623}
2624
f11d78f2 2625static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2626{
2627 struct ssh_channel *c = (struct ssh_channel *)cv;
2628 Ssh ssh = c->ssh;
2629 void *sentreply = reply;
2630
2631 if (!sentreply) {
2632 /* Fake SSH_AGENT_FAILURE. */
2633 sentreply = "\0\0\0\1\5";
2634 replylen = 5;
2635 }
2636 if (ssh->version == 2) {
2637 ssh2_add_channel_data(c, sentreply, replylen);
2638 ssh2_try_send(c);
2639 } else {
2640 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2641 PKT_INT, c->remoteid,
9a10ecf4 2642 PKTT_DATA,
839f10db 2643 PKT_INT, replylen,
2644 PKT_DATA, sentreply, replylen,
9a10ecf4 2645 PKTT_OTHER,
839f10db 2646 PKT_END);
2647 }
2648 if (reply)
2649 sfree(reply);
2650}
2651
0405e71f 2652/*
fb09bf1c 2653 * Handle the key exchange and user authentication phases.
2654 */
ff3187f6 2655static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2656 struct Packet *pktin)
fb09bf1c 2657{
0016d70b 2658 int i, j, ret;
2659 unsigned char cookie[8], *ptr;
374330e2 2660 struct RSAKey servkey, hostkey;
2661 struct MD5Context md5c;
51470298 2662 struct do_ssh1_login_state {
2663 int len;
2664 unsigned char *rsabuf, *keystr1, *keystr2;
2665 unsigned long supported_ciphers_mask, supported_auths_mask;
2666 int tried_publickey, tried_agent;
2667 int tis_auth_refused, ccard_auth_refused;
2668 unsigned char session_id[16];
2669 int cipher_type;
2670 char username[100];
2671 void *publickey_blob;
2672 int publickey_bloblen;
2673 char password[100];
2674 char prompt[200];
2675 int pos;
2676 char c;
2677 int pwpkt_type;
2678 unsigned char request[5], *response, *p;
2679 int responselen;
2680 int keyi, nkeys;
2681 int authed;
2682 struct RSAKey key;
2683 Bignum challenge;
2684 char *commentp;
2685 int commentlen;
2686 };
2687 crState(do_ssh1_login_state);
2688
2689 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2690
ff3187f6 2691 if (!pktin)
2692 crWaitUntil(pktin);
374330e2 2693
ff3187f6 2694 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2695 bombout(("Public key packet not received"));
7ffdbc1a 2696 crStop(0);
8d5de777 2697 }
374330e2 2698
c5e9c988 2699 logevent("Received public keys");
374330e2 2700
ff3187f6 2701 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2702 if (!ptr) {
2703 bombout(("SSH1 public key packet stopped before random cookie"));
2704 crStop(0);
2705 }
2706 memcpy(cookie, ptr, 8);
374330e2 2707
ff3187f6 2708 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2709 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2710 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2711 crStop(0);
2712 }
374330e2 2713
c5e9c988 2714 /*
1c2a93c4 2715 * Log the host key fingerprint.
c5e9c988 2716 */
c5e9c988 2717 {
2718 char logmsg[80];
1c2a93c4 2719 logevent("Host key fingerprint is:");
c5e9c988 2720 strcpy(logmsg, " ");
32874aea 2721 hostkey.comment = NULL;
2722 rsa_fingerprint(logmsg + strlen(logmsg),
2723 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2724 logevent(logmsg);
2725 }
2726
ff3187f6 2727 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2728 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2729 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2730
51470298 2731 ssh->v1_local_protoflags =
2732 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2733 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2734
c5e9c988 2735 MD5Init(&md5c);
51470298 2736 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2737 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2738 MD5Update(&md5c, cookie, 8);
51470298 2739 MD5Final(s->session_id, &md5c);
374330e2 2740
32874aea 2741 for (i = 0; i < 32; i++)
51470298 2742 ssh->session_key[i] = random_byte();
374330e2 2743
0016d70b 2744 /*
2745 * Verify that the `bits' and `bytes' parameters match.
2746 */
2747 if (hostkey.bits > hostkey.bytes * 8 ||
2748 servkey.bits > servkey.bytes * 8) {
2749 bombout(("SSH1 public keys were badly formatted"));
2750 crStop(0);
2751 }
2752
51470298 2753 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2754
3d88e64d 2755 s->rsabuf = snewn(s->len, unsigned char);
51470298 2756 if (!s->rsabuf)
374330e2 2757 fatalbox("Out of memory");
2758
89ee5268 2759 /*
2760 * Verify the host key.
2761 */
2762 {
32874aea 2763 /*
2764 * First format the key into a string.
2765 */
2766 int len = rsastr_len(&hostkey);
2767 char fingerprint[100];
3d88e64d 2768 char *keystr = snewn(len, char);
32874aea 2769 if (!keystr)
2770 fatalbox("Out of memory");
2771 rsastr_fmt(keystr, &hostkey);
2772 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2773 verify_ssh_host_key(ssh->frontend,
2774 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2775 fingerprint);
2776 sfree(keystr);
2777 }
2778
2779 for (i = 0; i < 32; i++) {
51470298 2780 s->rsabuf[i] = ssh->session_key[i];
374330e2 2781 if (i < 16)
51470298 2782 s->rsabuf[i] ^= s->session_id[i];
374330e2 2783 }
2784
2785 if (hostkey.bytes > servkey.bytes) {
0016d70b 2786 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2787 if (ret)
2788 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2789 } else {
0016d70b 2790 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2791 if (ret)
2792 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2793 }
2794 if (!ret) {
2795 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2796 crStop(0);
374330e2 2797 }
2798
c5e9c988 2799 logevent("Encrypted session key");
2800
ca20bfcf 2801 {
2802 int cipher_chosen = 0, warn = 0;
2803 char *cipher_string = NULL;
51470298 2804 int i;
ca20bfcf 2805 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2806 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2807 if (next_cipher == CIPHER_WARN) {
2808 /* If/when we choose a cipher, warn about it */
2809 warn = 1;
2810 } else if (next_cipher == CIPHER_AES) {
2811 /* XXX Probably don't need to mention this. */
2812 logevent("AES not supported in SSH1, skipping");
2813 } else {
2814 switch (next_cipher) {
51470298 2815 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2816 cipher_string = "3DES"; break;
51470298 2817 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2818 cipher_string = "Blowfish"; break;
51470298 2819 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2820 cipher_string = "single-DES"; break;
2821 }
51470298 2822 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2823 cipher_chosen = 1;
2824 }
2825 }
2826 if (!cipher_chosen) {
51470298 2827 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2828 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2829 "supporting 3DES encryption"));
2830 else
2831 /* shouldn't happen */
6b5cf8b4 2832 bombout(("No supported ciphers found"));
7ffdbc1a 2833 crStop(0);
a99a05c0 2834 }
ca20bfcf 2835
2836 /* Warn about chosen cipher if necessary. */
2837 if (warn)
83e7d008 2838 askalg(ssh->frontend, "cipher", cipher_string);
bea1ef5f 2839 }
ca20bfcf 2840
51470298 2841 switch (s->cipher_type) {
32874aea 2842 case SSH_CIPHER_3DES:
2843 logevent("Using 3DES encryption");
2844 break;
2845 case SSH_CIPHER_DES:
2846 logevent("Using single-DES encryption");
2847 break;
2848 case SSH_CIPHER_BLOWFISH:
2849 logevent("Using Blowfish encryption");
2850 break;
c5e9c988 2851 }
bea1ef5f 2852
51470298 2853 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2854 PKT_CHAR, s->cipher_type,
32874aea 2855 PKT_DATA, cookie, 8,
51470298 2856 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2857 PKT_DATA, s->rsabuf, s->len,
2858 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2859
c5e9c988 2860 logevent("Trying to enable encryption...");
374330e2 2861
51470298 2862 sfree(s->rsabuf);
374330e2 2863
51470298 2864 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2865 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2866 &ssh_3des);
371e569c 2867 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2868 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2869 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2870
0183b242 2871 ssh->crcda_ctx = crcda_make_context();
2872 logevent("Installing CRC compensation attack detector");
2873
679539d7 2874 if (servkey.modulus) {
2875 sfree(servkey.modulus);
2876 servkey.modulus = NULL;
2877 }
2878 if (servkey.exponent) {
2879 sfree(servkey.exponent);
2880 servkey.exponent = NULL;
2881 }
2882 if (hostkey.modulus) {
2883 sfree(hostkey.modulus);
2884 hostkey.modulus = NULL;
2885 }
2886 if (hostkey.exponent) {
2887 sfree(hostkey.exponent);
2888 hostkey.exponent = NULL;
2889 }
ff3187f6 2890 crWaitUntil(pktin);
374330e2 2891
ff3187f6 2892 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2893 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2894 crStop(0);
8d5de777 2895 }
374330e2 2896
c5e9c988 2897 logevent("Successfully started encryption");
2898
374330e2 2899 fflush(stdout);
2900 {
aa09f7d0 2901 if (!*ssh->cfg.username) {
c0a81592 2902 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2903 if (!ssh_get_line("login as: ",
51470298 2904 s->username, sizeof(s->username), FALSE)) {
32874aea 2905 /*
2906 * get_line failed to get a username.
2907 * Terminate.
2908 */
2909 logevent("No username provided. Abandoning session.");
3bb2f322 2910 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2911 crStop(1);
32874aea 2912 }
2913 } else {
51470298 2914 int ret; /* need not be kept over crReturn */
2915 c_write_str(ssh, "login as: ");
2916 ssh->send_ok = 1;
0405e71f 2917
51470298 2918 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2919 do {
ff3187f6 2920 crWaitUntil(!pktin);
51470298 2921 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2922 } while (ret == 0);
2923 if (ret < 0)
2924 cleanup_exit(0);
51470298 2925 c_write_str(ssh, "\r\n");
32874aea 2926 }
2927 } else {
86916870 2928 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2929 s->username[sizeof(s->username)-1] = '\0';
374330e2 2930 }
fb09bf1c 2931
51470298 2932 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2933 {
51470298 2934 char userlog[22 + sizeof(s->username)];
2935 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2936 logevent(userlog);
32874aea 2937 if (flags & FLAG_INTERACTIVE &&
2938 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2939 strcat(userlog, "\r\n");
51470298 2940 c_write_str(ssh, userlog);
3c8e959b 2941 }
c5e9c988 2942 }
374330e2 2943 }
2944
ff3187f6 2945 crWaitUntil(pktin);
374330e2 2946
51470298 2947 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2948 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2949 s->tried_publickey = s->tried_agent = 1;
0df73905 2950 } else {
51470298 2951 s->tried_publickey = s->tried_agent = 0;
0df73905 2952 }
51470298 2953 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2954 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2955 if (!filename_is_null(ssh->cfg.keyfile)) {
2956 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2957 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2958 s->publickey_blob = NULL;
396778f1 2959 } else
51470298 2960 s->publickey_blob = NULL;
7cca0d81 2961
ff3187f6 2962 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2963 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2964
51470298 2965 if (agent_exists() && !s->tried_agent) {
32874aea 2966 /*
2967 * Attempt RSA authentication using Pageant.
2968 */
32874aea 2969 void *r;
2970
51470298 2971 s->authed = FALSE;
2972 s->tried_agent = 1;
32874aea 2973 logevent("Pageant is running. Requesting keys.");
2974
2975 /* Request the keys held by the agent. */
51470298 2976 PUT_32BIT(s->request, 1);
2977 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2978 if (!agent_query(s->request, 5, &r, &s->responselen,
2979 ssh_agent_callback, ssh)) {
2980 do {
2981 crReturn(0);
ff3187f6 2982 if (pktin) {
839f10db 2983 bombout(("Unexpected data from server while waiting"
2984 " for agent response"));
2985 crStop(0);
2986 }
ff3187f6 2987 } while (pktin || inlen > 0);
839f10db 2988 r = ssh->agent_response;
2989 s->responselen = ssh->agent_response_len;
2990 }
51470298 2991 s->response = (unsigned char *) r;
2992 if (s->response && s->responselen >= 5 &&
2993 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2994 s->p = s->response + 5;
2995 s->nkeys = GET_32BIT(s->p);
2996 s->p += 4;
32874aea 2997 {
2998 char buf[64];
51470298 2999 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 3000 logevent(buf);
3001 }
51470298 3002 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 3003 {
3004 char buf[64];
51470298 3005 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 3006 logevent(buf);
3007 }
51470298 3008 if (s->publickey_blob &&
3009 !memcmp(s->p, s->publickey_blob,
3010 s->publickey_bloblen)) {
396778f1 3011 logevent("This key matches configured key file");
51470298 3012 s->tried_publickey = 1;
396778f1 3013 }
51470298 3014 s->p += 4;
0016d70b 3015 {
3016 int n, ok = FALSE;
3017 do { /* do while (0) to make breaking easy */
3018 n = ssh1_read_bignum
3019 (s->p, s->responselen-(s->p-s->response),
3020 &s->key.exponent);
3021 if (n < 0)
3022 break;
3023 s->p += n;
3024 n = ssh1_read_bignum
3025 (s->p, s->responselen-(s->p-s->response),
3026 &s->key.modulus);
3027 if (n < 0)
3028 break;
3029 s->p += n;
3030 if (s->responselen - (s->p-s->response) < 4)
3031 break;
3032 s->commentlen = GET_32BIT(s->p);
3033 s->p += 4;
3034 if (s->responselen - (s->p-s->response) <
3035 s->commentlen)
3036 break;
3037 s->commentp = (char *)s->p;
3038 s->p += s->commentlen;
3039 ok = TRUE;
3040 } while (0);
3041 if (!ok) {
3042 logevent("Pageant key list packet was truncated");
3043 break;
3044 }
3045 }
51470298 3046 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3047 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3048 crWaitUntil(pktin);
3049 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3050 logevent("Key refused");
3051 continue;
3052 }
3053 logevent("Received RSA challenge");
ff3187f6 3054 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3055 bombout(("Server's RSA challenge was badly formatted"));
3056 crStop(0);
3057 }
3058
32874aea 3059 {
3060 char *agentreq, *q, *ret;
2d466ffd 3061 void *vret;
32874aea 3062 int len, retlen;
3063 len = 1 + 4; /* message type, bit count */
51470298 3064 len += ssh1_bignum_length(s->key.exponent);
3065 len += ssh1_bignum_length(s->key.modulus);
3066 len += ssh1_bignum_length(s->challenge);
32874aea 3067 len += 16; /* session id */
3068 len += 4; /* response format */
3d88e64d 3069 agentreq = snewn(4 + len, char);
32874aea 3070 PUT_32BIT(agentreq, len);
3071 q = agentreq + 4;
3072 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3073 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3074 q += 4;
51470298 3075 q += ssh1_write_bignum(q, s->key.exponent);
3076 q += ssh1_write_bignum(q, s->key.modulus);
3077 q += ssh1_write_bignum(q, s->challenge);
3078 memcpy(q, s->session_id, 16);
32874aea 3079 q += 16;
3080 PUT_32BIT(q, 1); /* response format */
839f10db 3081 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3082 ssh_agent_callback, ssh)) {
3083 sfree(agentreq);
3084 do {
3085 crReturn(0);
ff3187f6 3086 if (pktin) {
839f10db 3087 bombout(("Unexpected data from server"
3088 " while waiting for agent"
3089 " response"));
3090 crStop(0);
3091 }
ff3187f6 3092 } while (pktin || inlen > 0);
839f10db 3093 vret = ssh->agent_response;
3094 retlen = ssh->agent_response_len;
3095 } else
3096 sfree(agentreq);
2d466ffd 3097 ret = vret;
32874aea 3098 if (ret) {
3099 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3100 logevent("Sending Pageant's response");
51470298 3101 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3102 PKT_DATA, ret + 5, 16,
3103 PKT_END);
3104 sfree(ret);
ff3187f6 3105 crWaitUntil(pktin);
3106 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3107 logevent
3108 ("Pageant's response accepted");
3109 if (flags & FLAG_VERBOSE) {
51470298 3110 c_write_str(ssh, "Authenticated using"
3111 " RSA key \"");
3112 c_write(ssh, s->commentp,
3113 s->commentlen);
3114 c_write_str(ssh, "\" from agent\r\n");
32874aea 3115 }
51470298 3116 s->authed = TRUE;
32874aea 3117 } else
3118 logevent
3119 ("Pageant's response not accepted");
3120 } else {
3121 logevent
3122 ("Pageant failed to answer challenge");
3123 sfree(ret);
3124 }
3125 } else {
3126 logevent("No reply received from Pageant");
3127 }
3128 }
51470298 3129 freebn(s->key.exponent);
3130 freebn(s->key.modulus);
3131 freebn(s->challenge);
3132 if (s->authed)
32874aea 3133 break;
3134 }
29b1d0b3 3135 sfree(s->response);
32874aea 3136 }
51470298 3137 if (s->authed)
32874aea 3138 break;
3139 }
9a30e26b 3140 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3141 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3142
86916870 3143 if (ssh->cfg.try_tis_auth &&
51470298 3144 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3145 !s->tis_auth_refused) {
3146 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3147 logevent("Requested TIS authentication");
51470298 3148 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3149 crWaitUntil(pktin);
3150 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3151 logevent("TIS authentication declined");
3152 if (flags & FLAG_INTERACTIVE)
51470298 3153 c_write_str(ssh, "TIS authentication refused.\r\n");
3154 s->tis_auth_refused = 1;
614a20a0 3155 continue;
32874aea 3156 } else {
0016d70b 3157 char *challenge;
3158 int challengelen;
3159
ff3187f6 3160 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3161 if (!challenge) {
3162 bombout(("TIS challenge packet was badly formed"));
3163 crStop(0);
3164 }
32874aea 3165 logevent("Received TIS challenge");
51470298 3166 if (challengelen > sizeof(s->prompt) - 1)
3167 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3168 memcpy(s->prompt, challenge, challengelen);
614a20a0 3169 /* Prompt heuristic comes from OpenSSH */
51470298 3170 strncpy(s->prompt + challengelen,
3171 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3172 "": "\r\nResponse: ",
51470298 3173 (sizeof s->prompt) - challengelen);
3174 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3175 }
3176 }
86916870 3177 if (ssh->cfg.try_tis_auth &&
51470298 3178 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3179 !s->ccard_auth_refused) {
3180 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3181 logevent("Requested CryptoCard authentication");
51470298 3182 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3183 crWaitUntil(pktin);
3184 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3185 logevent("CryptoCard authentication declined");
51470298 3186 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3187 s->ccard_auth_refused = 1;
614a20a0 3188 continue;
32874aea 3189 } else {
0016d70b 3190 char *challenge;
3191 int challengelen;
3192
ff3187f6 3193 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3194 if (!challenge) {
3195 bombout(("CryptoCard challenge packet was badly formed"));
3196 crStop(0);
3197 }
32874aea 3198 logevent("Received CryptoCard challenge");
51470298 3199 if (challengelen > sizeof(s->prompt) - 1)
3200 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3201 memcpy(s->prompt, challenge, challengelen);
51470298 3202 strncpy(s->prompt + challengelen,
3203 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3204 "" : "\r\nResponse: ",
51470298 3205 sizeof(s->prompt) - challengelen);
3206 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3207 }
3208 }
51470298 3209 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3210 sprintf(s->prompt, "%.90s@%.90s's password: ",
3211 s->username, ssh->savedhost);
32874aea 3212 }
51470298 3213 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3214 char *comment = NULL;
231ee168 3215 int type;
3216 char msgbuf[256];
32874aea 3217 if (flags & FLAG_VERBOSE)
51470298 3218 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3219 logeventf(ssh, "Trying public key \"%s\"",
3220 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3221 type = key_type(&ssh->cfg.keyfile);
231ee168 3222 if (type != SSH_KEYTYPE_SSH1) {
3223 sprintf(msgbuf, "Key is of wrong type (%s)",
3224 key_type_to_str(type));
3225 logevent(msgbuf);
51470298 3226 c_write_str(ssh, msgbuf);
3227 c_write_str(ssh, "\r\n");
3228 s->tried_publickey = 1;
231ee168 3229 continue;
3230 }
9a30e26b 3231 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3232 if (flags & FLAG_VERBOSE)
51470298 3233 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3234 goto tryauth;
3235 }
51470298 3236 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3237 sfree(comment);
3238 }
a52f067e 3239
614a20a0 3240 /*
3241 * Show password prompt, having first obtained it via a TIS
3242 * or CryptoCard exchange if we're doing TIS or CryptoCard
3243 * authentication.
3244 */
fa17a66e 3245 if (ssh_get_line) {
51470298 3246 if (!ssh_get_line(s->prompt, s->password,
3247 sizeof(s->password), TRUE)) {
32874aea 3248 /*
3249 * get_line failed to get a password (for example
3250 * because one was supplied on the command line
3251 * which has already failed to work). Terminate.
3252 */
51470298 3253 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3254 PKT_STR, "No more passwords available to try",
3255 PKT_END);
247308b5 3256 logevent("Unable to authenticate");
a8327734 3257 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3258 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3259 crStop(1);
32874aea 3260 }
fb09bf1c 3261 } else {
614a20a0 3262 /* Prompt may have come from server. We've munged it a bit, so
3263 * we know it to be zero-terminated at least once. */
51470298 3264 int ret; /* need not be saved over crReturn */
3265 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3266 s->pos = 0;
0405e71f 3267
51470298 3268 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3269 do {
ff3187f6 3270 crWaitUntil(!pktin);
51470298 3271 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3272 } while (ret == 0);
3273 if (ret < 0)
3274 cleanup_exit(0);
51470298 3275 c_write_str(ssh, "\r\n");
32874aea 3276 }
3277
3278 tryauth:
51470298 3279 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3280 /*
3281 * Try public key authentication with the specified
3282 * key file.
3283 */
51470298 3284 s->tried_publickey = 1;
3285
3286 {
222d54dc 3287 const char *error = NULL;
3288 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3289 &error);
51470298 3290 if (ret == 0) {
3291 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3292 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3293 c_write_str(ssh, " (");
3294 c_write_str(ssh, error);
3295 c_write_str(ssh, ").\r\n");
51470298 3296 continue; /* go and try password */
3297 }
3298 if (ret == -1) {
3299 c_write_str(ssh, "Wrong passphrase.\r\n");
3300 s->tried_publickey = 0;
3301 continue; /* try again */
3302 }
32874aea 3303 }
3304
3305 /*
3306 * Send a public key attempt.
3307 */
51470298 3308 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3309 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3310
ff3187f6 3311 crWaitUntil(pktin);
3312 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3313 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3314 continue; /* go and try password */
3315 }
ff3187f6 3316 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3317 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3318 crStop(0);
32874aea 3319 }
32874aea 3320
51470298 3321 {
3322 int i;
3323 unsigned char buffer[32];
3324 Bignum challenge, response;
3325
ff3187f6 3326 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3327 bombout(("Server's RSA challenge was badly formatted"));
3328 crStop(0);
3329 }
51470298 3330 response = rsadecrypt(challenge, &s->key);
3331 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3332
51470298 3333 for (i = 0; i < 32; i++) {
3334 buffer[i] = bignum_byte(response, 31 - i);
3335 }
3336
3337 MD5Init(&md5c);
3338 MD5Update(&md5c, buffer, 32);
3339 MD5Update(&md5c, s->session_id, 16);
3340 MD5Final(buffer, &md5c);
32874aea 3341
51470298 3342 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3343 PKT_DATA, buffer, 16, PKT_END);
3344
3345 freebn(challenge);
3346 freebn(response);
3347 }
32874aea 3348
ff3187f6 3349 crWaitUntil(pktin);
3350 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3351 if (flags & FLAG_VERBOSE)
51470298 3352 c_write_str(ssh, "Failed to authenticate with"
3353 " our public key.\r\n");
32874aea 3354 continue; /* go and try password */
ff3187f6 3355 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3356 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3357 crStop(0);
32874aea 3358 }
3359
3360 break; /* we're through! */
3361 } else {
51470298 3362 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3363 /*
3364 * Defence against traffic analysis: we send a
3365 * whole bunch of packets containing strings of
3366 * different lengths. One of these strings is the
3367 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3368 * The others are all random data in
3369 * SSH1_MSG_IGNORE packets. This way a passive
3370 * listener can't tell which is the password, and
3371 * hence can't deduce the password length.
3372 *
3373 * Anybody with a password length greater than 16
3374 * bytes is going to have enough entropy in their
3375 * password that a listener won't find it _that_
3376 * much help to know how long it is. So what we'll
3377 * do is:
3378 *
3379 * - if password length < 16, we send 15 packets
3380 * containing string lengths 1 through 15
3381 *
3382 * - otherwise, we let N be the nearest multiple
3383 * of 8 below the password length, and send 8
3384 * packets containing string lengths N through
3385 * N+7. This won't obscure the order of
3386 * magnitude of the password length, but it will
3387 * introduce a bit of extra uncertainty.
3388 *
3389 * A few servers (the old 1.2.18 through 1.2.22)
3390 * can't deal with SSH1_MSG_IGNORE. For these
3391 * servers, we need an alternative defence. We make
3392 * use of the fact that the password is interpreted
3393 * as a C string: so we can append a NUL, then some
3394 * random data.
bd358db1 3395 *
3396 * One server (a Cisco one) can deal with neither
3397 * SSH1_MSG_IGNORE _nor_ a padded password string.
3398 * For this server we are left with no defences
3399 * against password length sniffing.
32874aea 3400 */
51470298 3401 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3402 /*
3403 * The server can deal with SSH1_MSG_IGNORE, so
3404 * we can use the primary defence.
3405 */
32874aea 3406 int bottom, top, pwlen, i;
3407 char *randomstr;
3408
51470298 3409 pwlen = strlen(s->password);
32874aea 3410 if (pwlen < 16) {
3411 bottom = 0; /* zero length passwords are OK! :-) */
3412 top = 15;
3413 } else {
3414 bottom = pwlen & ~7;
3415 top = bottom + 7;
3416 }
3417
3418 assert(pwlen >= bottom && pwlen <= top);
3419
3d88e64d 3420 randomstr = snewn(top + 1, char);
32874aea 3421
3422 for (i = bottom; i <= top; i++) {
9a10ecf4 3423 if (i == pwlen) {
51470298 3424 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3425 PKTT_PASSWORD, PKT_STR, s->password,
3426 PKTT_OTHER, PKT_END);
3427 } else {
32874aea 3428 for (j = 0; j < i; j++) {
3429 do {
3430 randomstr[j] = random_byte();
3431 } while (randomstr[j] == '\0');
3432 }
3433 randomstr[i] = '\0';
51470298 3434 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3435 PKT_STR, randomstr, PKT_END);
3436 }
3437 }
bd358db1 3438 logevent("Sending password with camouflage packets");
51470298 3439 ssh_pkt_defersend(ssh);
679539d7 3440 sfree(randomstr);
bd358db1 3441 }
51470298 3442 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3443 /*
3444 * The server can't deal with SSH1_MSG_IGNORE
3445 * but can deal with padded passwords, so we
3446 * can use the secondary defence.
3447 */
bd358db1 3448 char string[64];
51470298 3449 char *ss;
bd358db1 3450 int len;
3451
51470298 3452 len = strlen(s->password);
bd358db1 3453 if (len < sizeof(string)) {
51470298 3454 ss = string;
3455 strcpy(string, s->password);
bd358db1 3456 len++; /* cover the zero byte */
3457 while (len < sizeof(string)) {
3458 string[len++] = (char) random_byte();
3459 }
3460 } else {
51470298 3461 ss = s->password;
bd358db1 3462 }
3463 logevent("Sending length-padded password");
9a10ecf4 3464 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3465 PKT_INT, len, PKT_DATA, ss, len,
3466 PKTT_OTHER, PKT_END);
bd358db1 3467 } else {
3468 /*
3469 * The server has _both_
3470 * BUG_CHOKES_ON_SSH1_IGNORE and
3471 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3472 * therefore nothing we can do.
3473 */
3474 int len;
51470298 3475 len = strlen(s->password);
bd358db1 3476 logevent("Sending unpadded password");
9a10ecf4 3477 send_packet(ssh, s->pwpkt_type,
3478 PKTT_PASSWORD, PKT_INT, len,
3479 PKT_DATA, s->password, len,
3480 PKTT_OTHER, PKT_END);
32874aea 3481 }
3482 } else {
9a10ecf4 3483 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3484 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3485 }
3486 }
c5e9c988 3487 logevent("Sent password");
51470298 3488 memset(s->password, 0, strlen(s->password));
ff3187f6 3489 crWaitUntil(pktin);
3490 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3491 if (flags & FLAG_VERBOSE)
51470298 3492 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3493 logevent("Authentication refused");
ff3187f6 3494 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3495 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3496 crStop(0);
374330e2 3497 }
3498 }
3499
c5e9c988 3500 logevent("Authentication successful");
3501
fb09bf1c 3502 crFinish(1);
3503}
3504
32874aea 3505void sshfwd_close(struct ssh_channel *c)
3506{
51470298 3507 Ssh ssh = c->ssh;
3508
36f94d1f 3509 if (ssh->state != SSH_STATE_SESSION) {
3510 assert(ssh->state == SSH_STATE_CLOSED);
3511 return;
3512 }
3513
80e48603 3514 if (c && !c->closes) {
4ed34d25 3515 /*
3516 * If the channel's remoteid is -1, we have sent
3517 * CHANNEL_OPEN for this channel, but it hasn't even been
3518 * acknowledged by the server. So we must set a close flag
3519 * on it now, and then when the server acks the channel
3520 * open, we can close it then.
3521 */
36cac739 3522 if (((int)c->remoteid) != -1) {
51470298 3523 if (ssh->version == 1) {
3524 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3525 PKT_END);
3526 } else {
ff3187f6 3527 struct Packet *pktout;
3528 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3529 ssh2_pkt_adduint32(pktout, c->remoteid);
3530 ssh2_pkt_send(ssh, pktout);
4ed34d25 3531 }
32874aea 3532 }
0357890f 3533 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3534 if (c->type == CHAN_X11) {
3535 c->u.x11.s = NULL;
d74d141c 3536 logevent("Forwarded X11 connection terminated");
4ed34d25 3537 } else if (c->type == CHAN_SOCKDATA ||
3538 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3539 c->u.pfd.s = NULL;
3540 logevent("Forwarded port closed");
32874aea 3541 }
3542 }
3543}
3544
5471d09a 3545int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3546{
51470298 3547 Ssh ssh = c->ssh;
3548
36f94d1f 3549 if (ssh->state != SSH_STATE_SESSION) {
3550 assert(ssh->state == SSH_STATE_CLOSED);
3551 return 0;
3552 }
3553
51470298 3554 if (ssh->version == 1) {
3555 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3556 PKT_INT, c->remoteid,
9a10ecf4 3557 PKTT_DATA,
3558 PKT_INT, len, PKT_DATA, buf, len,
3559 PKTT_OTHER, PKT_END);
5471d09a 3560 /*
3561 * In SSH1 we can return 0 here - implying that forwarded
3562 * connections are never individually throttled - because
3563 * the only circumstance that can cause throttling will be
3564 * the whole SSH connection backing up, in which case
3565 * _everything_ will be throttled as a whole.
3566 */
3567 return 0;
783415f8 3568 } else {
32874aea 3569 ssh2_add_channel_data(c, buf, len);
5471d09a 3570 return ssh2_try_send(c);
3571 }
3572}
3573
3574void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3575{
51470298 3576 Ssh ssh = c->ssh;
3577
36f94d1f 3578 if (ssh->state != SSH_STATE_SESSION) {
3579 assert(ssh->state == SSH_STATE_CLOSED);
3580 return;
3581 }
3582
51470298 3583 if (ssh->version == 1) {
5471d09a 3584 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3585 c->v.v1.throttling = 0;
51470298 3586 ssh1_throttle(ssh, -1);
5471d09a 3587 }
3588 } else {
3589 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3590 }
9c964e85 3591}
3592
06fadff5 3593static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3594{
3595 struct queued_handler *qh = ssh->qhead;
3596
3597 assert(qh != NULL);
3598
3599 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3600
3601 if (qh->msg1 > 0) {
3602 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3603 ssh->packet_dispatch[qh->msg1] = NULL;
3604 }
3605 if (qh->msg2 > 0) {
3606 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3607 ssh->packet_dispatch[qh->msg2] = NULL;
3608 }
3609
3610 if (qh->next) {
3611 ssh->qhead = qh->next;
3612
3613 if (ssh->qhead->msg1 > 0) {
3614 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3615 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3616 }
3617 if (ssh->qhead->msg2 > 0) {
3618 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3619 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3620 }
3621 } else {
3622 ssh->qhead = ssh->qtail = NULL;
3623 ssh->packet_dispatch[pktin->type] = NULL;
3624 }
3625
3626 qh->handler(ssh, pktin, qh->ctx);
3627
3628 sfree(qh);
3629}
3630
3631static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3632 chandler_fn_t handler, void *ctx)
3633{
3634 struct queued_handler *qh;
3635
3636 qh = snew(struct queued_handler);
3637 qh->msg1 = msg1;
3638 qh->msg2 = msg2;
3639 qh->handler = handler;
3640 qh->ctx = ctx;
3641 qh->next = NULL;
3642
3643 if (ssh->qtail == NULL) {
3644 ssh->qhead = qh;
3645
3646 if (qh->msg1 > 0) {
3647 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3648 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3649 }
3650 if (qh->msg2 > 0) {
3651 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3652 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3653 }
3654 } else {
3655 ssh->qtail->next = qh;
3656 }
3657 ssh->qtail = qh;
3658}
3659
3660static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3661{
3662 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3663
3664 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3665 SSH2_MSG_REQUEST_SUCCESS)) {
3666 logeventf(ssh, "Remote port forwarding from %s enabled",
3667 pf->sportdesc);
3668 } else {
3669 logeventf(ssh, "Remote port forwarding from %s refused",
3670 pf->sportdesc);
3671
3672 rpf = del234(ssh->rportfwds, pf);
3673 assert(rpf == pf);
fda2feb1 3674 free_rportfwd(pf);
06fadff5 3675 }
3676}
3677
3678static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3679{
84328ddb 3680 const char *portfwd_strptr = cfg->portfwd;
3681 struct ssh_portfwd *epf;
3682 int i;
06fadff5 3683
fda2feb1 3684 if (!ssh->portfwds) {
3685 ssh->portfwds = newtree234(ssh_portcmp);
3686 } else {
3687 /*
3688 * Go through the existing port forwardings and tag them
84328ddb 3689 * with status==DESTROY. Any that we want to keep will be
3690 * re-enabled (status==KEEP) as we go through the
3691 * configuration and find out which bits are the same as
3692 * they were before.
fda2feb1 3693 */
3694 struct ssh_portfwd *epf;
3695 int i;
3696 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3697 epf->status = DESTROY;
fda2feb1 3698 }
3699
06fadff5 3700 while (*portfwd_strptr) {
84328ddb 3701 char address_family, type;
3702 int sport,dport,sserv,dserv;
3703 char sports[256], dports[256], saddr[256], host[256];
3704 int n;
3705
05581745 3706 address_family = 'A';
3707 type = 'L';
84328ddb 3708 if (*portfwd_strptr == 'A' ||
3709 *portfwd_strptr == '4' ||
3710 *portfwd_strptr == '6')
3711 address_family = *portfwd_strptr++;
3712 if (*portfwd_strptr == 'L' ||
3713 *portfwd_strptr == 'R' ||
3714 *portfwd_strptr == 'D')
3715 type = *portfwd_strptr++;
05581745 3716
06fadff5 3717 saddr[0] = '\0';
05581745 3718
06fadff5 3719 n = 0;
3720 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3721 if (*portfwd_strptr == ':') {
3722 /*
3723 * We've seen a colon in the middle of the
3724 * source port number. This means that
3725 * everything we've seen until now is the
3726 * source _address_, so we'll move it into
3727 * saddr and start sports from the beginning
3728 * again.
3729 */
3730 portfwd_strptr++;
3731 sports[n] = '\0';
3732 if (ssh->version == 1 && type == 'R') {
3733 logeventf(ssh, "SSH1 cannot handle remote source address "
3734 "spec \"%s\"; ignoring", sports);
3735 } else
3736 strcpy(saddr, sports);
3737 n = 0;
3738 }
3739 if (n < 255) sports[n++] = *portfwd_strptr++;
3740 }
3741 sports[n] = 0;
3742 if (type != 'D') {
3743 if (*portfwd_strptr == '\t')
3744 portfwd_strptr++;
3745 n = 0;
3746 while (*portfwd_strptr && *portfwd_strptr != ':') {
3747 if (n < 255) host[n++] = *portfwd_strptr++;
3748 }
3749 host[n] = 0;
3750 if (*portfwd_strptr == ':')
3751 portfwd_strptr++;
3752 n = 0;
3753 while (*portfwd_strptr) {
3754 if (n < 255) dports[n++] = *portfwd_strptr++;
3755 }
3756 dports[n] = 0;
3757 portfwd_strptr++;
3758 dport = atoi(dports);
3759 dserv = 0;
3760 if (dport == 0) {
3761 dserv = 1;
3762 dport = net_service_lookup(dports);
3763 if (!dport) {
3764 logeventf(ssh, "Service lookup failed for destination"
3765 " port \"%s\"", dports);
3766 }
3767 }
3768 } else {
3769 while (*portfwd_strptr) portfwd_strptr++;
3770 dport = dserv = -1;
3771 portfwd_strptr++; /* eat the NUL and move to next one */
3772 }
3773 sport = atoi(sports);
3774 sserv = 0;
3775 if (sport == 0) {
3776 sserv = 1;
3777 sport = net_service_lookup(sports);
3778 if (!sport) {
3779 logeventf(ssh, "Service lookup failed for source"
3780 " port \"%s\"", sports);
3781 }
3782 }
3783 if (sport && dport) {
3784 /* Set up a description of the source port. */
fda2feb1 3785 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3786
3787 pfrec = snew(struct ssh_portfwd);
3788 pfrec->type = type;
3789 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3790 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3791 pfrec->sport = sport;
84328ddb 3792 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3793 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3794 pfrec->dport = dport;
3795 pfrec->local = NULL;
3796 pfrec->remote = NULL;
05581745 3797 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3798 address_family == '6' ? ADDRTYPE_IPV6 :
3799 ADDRTYPE_UNSPEC);
fda2feb1 3800
3801 epfrec = add234(ssh->portfwds, pfrec);
3802 if (epfrec != pfrec) {
3803 /*
3804 * We already have a port forwarding with precisely
3805 * these parameters. Hence, no need to do anything;
84328ddb 3806 * simply tag the existing one as KEEP.
fda2feb1 3807 */
84328ddb 3808 epfrec->status = KEEP;
fda2feb1 3809 free_portfwd(pfrec);
84328ddb 3810 } else {
3811 pfrec->status = CREATE;
3812 }
3813 }
3814 }
3815
3816 /*
3817 * Now go through and destroy any port forwardings which were
3818 * not re-enabled.
3819 */
3820 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3821 if (epf->status == DESTROY) {
3822 char *message;
3823
3824 message = dupprintf("%s port forwarding from %s%s%d",
3825 epf->type == 'L' ? "local" :
3826 epf->type == 'R' ? "remote" : "dynamic",
3827 epf->saddr ? epf->saddr : "",
3828 epf->saddr ? ":" : "",
3829 epf->sport);
3830
3831 if (epf->type != 'D') {
3832 char *msg2 = dupprintf("%s to %s:%d", message,
3833 epf->daddr, epf->dport);
3834 sfree(message);
3835 message = msg2;
3836 }
3837
3838 logeventf(ssh, "Cancelling %s", message);
3839 sfree(message);
3840
3841 if (epf->remote) {
3842 struct ssh_rportfwd *rpf = epf->remote;
3843 struct Packet *pktout;
3844
3845 /*
3846 * Cancel the port forwarding at the server
3847 * end.
3848 */
3849 if (ssh->version == 1) {
3850 /*
3851 * We cannot cancel listening ports on the
3852 * server side in SSH1! There's no message
3853 * to support it. Instead, we simply remove
3854 * the rportfwd record from the local end
3855 * so that any connections the server tries
3856 * to make on it are rejected.
3857 */
3858 } else {
3859 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3860 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3861 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3862 if (epf->saddr) {
3863 ssh2_pkt_addstring(pktout, epf->saddr);
3864 } else if (ssh->cfg.rport_acceptall) {
3865 ssh2_pkt_addstring(pktout, "0.0.0.0");
3866 } else {
3867 ssh2_pkt_addstring(pktout, "127.0.0.1");
3868 }
3869 ssh2_pkt_adduint32(pktout, epf->sport);
3870 ssh2_pkt_send(ssh, pktout);
3871 }
3872
3873 del234(ssh->rportfwds, rpf);
3874 free_rportfwd(rpf);
3875 } else if (epf->local) {
3876 pfd_terminate(epf->local);
3877 }
3878
3879 delpos234(ssh->portfwds, i);
3880 free_portfwd(epf);
3881 i--; /* so we don't skip one in the list */
3882 }
3883
3884 /*
3885 * And finally, set up any new port forwardings (status==CREATE).
3886 */
3887 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3888 if (epf->status == CREATE) {
3889 char *sportdesc, *dportdesc;
3fe92132 3890 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 3891 epf->saddr ? epf->saddr : "",
3892 epf->saddr ? ":" : "",
3fe92132 3893 epf->sserv ? epf->sserv : "",
3894 epf->sserv ? "(" : "",
3895 epf->sport,
3896 epf->sserv ? ")" : "");
84328ddb 3897 if (epf->type == 'D') {
3898 dportdesc = NULL;
3899 } else {
3fe92132 3900 dportdesc = dupprintf("%s:%s%s%d%s",
3901 epf->daddr,
3902 epf->dserv ? epf->dserv : "",
3903 epf->dserv ? "(" : "",
3904 epf->dport,
3905 epf->dserv ? ")" : "");
84328ddb 3906 }
05581745 3907
84328ddb 3908 if (epf->type == 'L') {
3909 const char *err = pfd_addforward(epf->daddr, epf->dport,
3910 epf->saddr, epf->sport,
3911 ssh, &ssh->cfg,
3912 &epf->local,
3913 epf->addressfamily);
3914
3915 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3916 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3917 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3918 sportdesc, dportdesc,
3919 err ? " failed: " : "", err ? err : "");
3920 } else if (epf->type == 'D') {
06fadff5 3921 const char *err = pfd_addforward(NULL, -1,
84328ddb 3922 epf->saddr, epf->sport,
3923 ssh, &ssh->cfg,
3924 &epf->local,
3925 epf->addressfamily);
3926
3927 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3928 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3929 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3930 sportdesc,
3931 err ? " failed: " : "", err ? err : "");
06fadff5 3932 } else {
3933 struct ssh_rportfwd *pf;
3934
3935 /*
3936 * Ensure the remote port forwardings tree exists.
3937 */
3938 if (!ssh->rportfwds) {
3939 if (ssh->version == 1)
3940 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3941 else
3942 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3943 }
3944
3945 pf = snew(struct ssh_rportfwd);
84328ddb 3946 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3947 pf->dhost[lenof(pf->dhost)-1] = '\0';
3948 pf->dport = epf->dport;
3949 pf->sport = epf->sport;
06fadff5 3950 if (add234(ssh->rportfwds, pf) != pf) {
3951 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 3952 epf->daddr, epf->dport);
06fadff5 3953 sfree(pf);
3954 } else {
3955 logeventf(ssh, "Requesting remote port %s"
84328ddb 3956 " forward to %s", sportdesc, dportdesc);
06fadff5 3957
3958 pf->sportdesc = sportdesc;
3959 sportdesc = NULL;
84328ddb 3960 epf->remote = pf;
3961 pf->pfrec = epf;
06fadff5 3962
3963 if (ssh->version == 1) {
3964 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 3965 PKT_INT, epf->sport,
3966 PKT_STR, epf->daddr,
3967 PKT_INT, epf->dport,
06fadff5 3968 PKT_END);
3969 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3970 SSH1_SMSG_FAILURE,
3971 ssh_rportfwd_succfail, pf);
3972 } else {
3973 struct Packet *pktout;
3974 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3975 ssh2_pkt_addstring(pktout, "tcpip-forward");
3976 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 3977 if (epf->saddr) {
3978 ssh2_pkt_addstring(pktout, epf->saddr);
06fadff5 3979 } else if (ssh->cfg.rport_acceptall) {
3980 ssh2_pkt_addstring(pktout, "0.0.0.0");
3981 } else {
3982 ssh2_pkt_addstring(pktout, "127.0.0.1");
3983 }
84328ddb 3984 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 3985 ssh2_pkt_send(ssh, pktout);
3986
3987 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3988 SSH2_MSG_REQUEST_FAILURE,
3989 ssh_rportfwd_succfail, pf);
3990 }
3991 }
3992 }
3993 sfree(sportdesc);
84328ddb 3994 sfree(dportdesc);
06fadff5 3995 }
06fadff5 3996}
3997
51df0ab5 3998static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3999{
4000 char *string;
4001 int stringlen, bufsize;
4002
4003 ssh_pkt_getstring(pktin, &string, &stringlen);
4004 if (string == NULL) {
4005 bombout(("Incoming terminal data packet was badly formed"));
4006 return;
4007 }
4008
4009 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4010 string, stringlen);
4011 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4012 ssh->v1_stdout_throttling = 1;
4013 ssh1_throttle(ssh, +1);
4014 }
4015}
4016
4017static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4018{
4019 /* Remote side is trying to open a channel to talk to our
4020 * X-Server. Give them back a local channel number. */
4021 struct ssh_channel *c;
4022 int remoteid = ssh_pkt_getuint32(pktin);
4023
4024 logevent("Received X11 connect request");
4025 /* Refuse if X11 forwarding is disabled. */
4026 if (!ssh->X11_fwd_enabled) {
4027 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4028 PKT_INT, remoteid, PKT_END);
4029 logevent("Rejected X11 connect request");
4030 } else {
4031 c = snew(struct ssh_channel);
4032 c->ssh = ssh;
4033
4034 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4035 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4036 logevent("Opening X11 forward connection failed");
4037 sfree(c);
4038 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4039 PKT_INT, remoteid, PKT_END);
4040 } else {
4041 logevent
4042 ("Opening X11 forward connection succeeded");
4043 c->remoteid = remoteid;
4044 c->localid = alloc_channel_id(ssh);
4045 c->closes = 0;
4046 c->v.v1.throttling = 0;
4047 c->type = CHAN_X11; /* identify channel type */
4048 add234(ssh->channels, c);
4049 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4050 PKT_INT, c->remoteid, PKT_INT,
4051 c->localid, PKT_END);
4052 logevent("Opened X11 forward channel");
4053 }
4054 }
4055}
4056
4057static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4058{
4059 /* Remote side is trying to open a channel to talk to our
4060 * agent. Give them back a local channel number. */
4061 struct ssh_channel *c;
4062 int remoteid = ssh_pkt_getuint32(pktin);
4063
4064 /* Refuse if agent forwarding is disabled. */
4065 if (!ssh->agentfwd_enabled) {
4066 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4067 PKT_INT, remoteid, PKT_END);
4068 } else {
4069 c = snew(struct ssh_channel);
4070 c->ssh = ssh;
4071 c->remoteid = remoteid;
4072 c->localid = alloc_channel_id(ssh);
4073 c->closes = 0;
4074 c->v.v1.throttling = 0;
4075 c->type = CHAN_AGENT; /* identify channel type */
4076 c->u.a.lensofar = 0;
4077 add234(ssh->channels, c);
4078 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4079 PKT_INT, c->remoteid, PKT_INT, c->localid,
4080 PKT_END);
4081 }
4082}
4083
4084static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4085{
4086 /* Remote side is trying to open a channel to talk to a
4087 * forwarded port. Give them back a local channel number. */
4088 struct ssh_channel *c;
05581745 4089 struct ssh_rportfwd pf, *pfp;
51df0ab5 4090 int remoteid;
4091 int hostsize, port;
4092 char *host, buf[1024];
4093 const char *e;
4094 c = snew(struct ssh_channel);
4095 c->ssh = ssh;
4096
4097 remoteid = ssh_pkt_getuint32(pktin);
4098 ssh_pkt_getstring(pktin, &host, &hostsize);
4099 port = ssh_pkt_getuint32(pktin);
4100
4101 if (hostsize >= lenof(pf.dhost))
4102 hostsize = lenof(pf.dhost)-1;
4103 memcpy(pf.dhost, host, hostsize);
4104 pf.dhost[hostsize] = '\0';
4105 pf.dport = port;
05581745 4106 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4107
05581745 4108 if (pfp == NULL) {
51df0ab5 4109 sprintf(buf, "Rejected remote port open request for %s:%d",
4110 pf.dhost, port);
4111 logevent(buf);
4112 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4113 PKT_INT, remoteid, PKT_END);
4114 } else {
4115 sprintf(buf, "Received remote port open request for %s:%d",
4116 pf.dhost, port);
4117 logevent(buf);
4118 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4119 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4120 if (e != NULL) {
4121 char buf[256];
4122 sprintf(buf, "Port open failed: %s", e);
4123 logevent(buf);
4124 sfree(c);
4125 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4126 PKT_INT, remoteid, PKT_END);
4127 } else {
4128 c->remoteid = remoteid;
4129 c->localid = alloc_channel_id(ssh);
4130 c->closes = 0;
4131 c->v.v1.throttling = 0;
4132 c->type = CHAN_SOCKDATA; /* identify channel type */
4133 add234(ssh->channels, c);
4134 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4135 PKT_INT, c->remoteid, PKT_INT,
4136 c->localid, PKT_END);
4137 logevent("Forwarded port opened successfully");
4138 }
4139 }
4140}
4141
4142static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4143{
4144 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4145 unsigned int localid = ssh_pkt_getuint32(pktin);
4146 struct ssh_channel *c;
4147
4148 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4149 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4150 c->remoteid = localid;
4151 c->type = CHAN_SOCKDATA;
4152 c->v.v1.throttling = 0;
4153 pfd_confirm(c->u.pfd.s);
4154 }
4155
4156 if (c && c->closes) {
4157 /*
4158 * We have a pending close on this channel,
4159 * which we decided on before the server acked
4160 * the channel open. So now we know the
4161 * remoteid, we can close it again.
4162 */
4163 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4164 PKT_INT, c->remoteid, PKT_END);
4165 }
4166}
4167
4168static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4169{
4170 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4171 struct ssh_channel *c;
4172
4173 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4174 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4175 logevent("Forwarded connection refused by server");
4176 pfd_close(c->u.pfd.s);
4177 del234(ssh->channels, c);
4178 sfree(c);
4179 }
4180}
4181
4182static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4183{
4184 /* Remote side closes a channel. */
4185 unsigned i = ssh_pkt_getuint32(pktin);
4186 struct ssh_channel *c;
4187 c = find234(ssh->channels, &i, ssh_channelfind);
4188 if (c && ((int)c->remoteid) != -1) {
4189 int closetype;
4190 closetype =
4191 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4192
4193 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4194 logevent("Forwarded X11 connection terminated");
4195 assert(c->u.x11.s != NULL);
4196 x11_close(c->u.x11.s);
4197 c->u.x11.s = NULL;
4198 }
4199 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4200 logevent("Forwarded port closed");
4201 assert(c->u.pfd.s != NULL);
4202 pfd_close(c->u.pfd.s);
4203 c->u.pfd.s = NULL;
4204 }
4205
4206 c->closes |= (closetype << 2); /* seen this message */
4207 if (!(c->closes & closetype)) {
4208 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4209 PKT_END);
4210 c->closes |= closetype; /* sent it too */
4211 }
4212
4213 if (c->closes == 15) {
4214 del234(ssh->channels, c);
4215 sfree(c);
4216 }
4217 } else {
4218 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4219 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4220 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4221 i));
4222 }
4223}
4224
4225static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4226{
4227 /* Data sent down one of our channels. */
4228 int i = ssh_pkt_getuint32(pktin);
4229 char *p;
aa63ab7e 4230 unsigned int len;
51df0ab5 4231 struct ssh_channel *c;
4232
4233 ssh_pkt_getstring(pktin, &p, &len);
4234
4235 c = find234(ssh->channels, &i, ssh_channelfind);
4236 if (c) {
4237 int bufsize = 0;
4238 switch (c->type) {
4239 case CHAN_X11:
4240 bufsize = x11_send(c->u.x11.s, p, len);
4241 break;
4242 case CHAN_SOCKDATA:
4243 bufsize = pfd_send(c->u.pfd.s, p, len);
4244 break;
4245 case CHAN_AGENT:
4246 /* Data for an agent message. Buffer it. */
4247 while (len > 0) {
4248 if (c->u.a.lensofar < 4) {
aa63ab7e 4249 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4250 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4251 l);
4252 p += l;
4253 len -= l;
4254 c->u.a.lensofar += l;
4255 }
4256 if (c->u.a.lensofar == 4) {
4257 c->u.a.totallen =
4258 4 + GET_32BIT(c->u.a.msglen);
4259 c->u.a.message = snewn(c->u.a.totallen,
4260 unsigned char);
4261 memcpy(c->u.a.message, c->u.a.msglen, 4);
4262 }
4263 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4264 unsigned int l =
51df0ab5 4265 min(c->u.a.totallen - c->u.a.lensofar,
4266 len);
4267 memcpy(c->u.a.message + c->u.a.lensofar, p,
4268 l);
4269 p += l;
4270 len -= l;
4271 c->u.a.lensofar += l;
4272 }
4273 if (c->u.a.lensofar == c->u.a.totallen) {
4274 void *reply;
4275 int replylen;
4276 if (agent_query(c->u.a.message,
4277 c->u.a.totallen,
4278 &reply, &replylen,
4279 ssh_agentf_callback, c))
4280 ssh_agentf_callback(c, reply, replylen);
4281 sfree(c->u.a.message);
4282 c->u.a.lensofar = 0;
4283 }
4284 }
4285 bufsize = 0; /* agent channels never back up */
4286 break;
4287 }
4288 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4289 c->v.v1.throttling = 1;
4290 ssh1_throttle(ssh, +1);
4291 }
4292 }
4293}
4294
4295static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4296{
4297 char buf[100];
4298 ssh->exitcode = ssh_pkt_getuint32(pktin);
4299 sprintf(buf, "Server sent command exit status %d",
4300 ssh->exitcode);
4301 logevent(buf);
4302 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4303 /*
4304 * In case `helpful' firewalls or proxies tack
4305 * extra human-readable text on the end of the
4306 * session which we might mistake for another
4307 * encrypted packet, we close the session once
4308 * we've sent EXIT_CONFIRMATION.
4309 */
4310 ssh_closing((Plug)ssh, NULL, 0, 0);
4311}
4312
b09eaa88 4313static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4314 struct Packet *pktin)
32874aea 4315{
b09eaa88 4316 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4317
51df0ab5 4318 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4319 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4320 ssh1_smsg_stdout_stderr_data;
4321
4322 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4323 ssh1_msg_channel_open_confirmation;
4324 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4325 ssh1_msg_channel_open_failure;
4326 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4327 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4328 ssh1_msg_channel_close;
4329 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4330 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4331
86916870 4332 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4333 logevent("Requesting agent forwarding");
51470298 4334 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4335 do {
4336 crReturnV;
ff3187f6 4337 } while (!pktin);
4338 if (pktin->type != SSH1_SMSG_SUCCESS
4339 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4340 bombout(("Protocol confusion"));
7ffdbc1a 4341 crStopV;
ff3187f6 4342 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4343 logevent("Agent forwarding refused");
4344 } else {
4345 logevent("Agent forwarding enabled");
51470298 4346 ssh->agentfwd_enabled = TRUE;
51df0ab5 4347 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4348 }
dacbd0e8 4349 }
4350
86916870 4351 if (ssh->cfg.x11_forward) {
32874aea 4352 char proto[20], data[64];
4353 logevent("Requesting X11 forwarding");
302121de 4354 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4355 data, sizeof(data), ssh->cfg.x11_auth);
4356 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4357 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4358 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4359 PKT_STR, proto, PKT_STR, data,
86916870 4360 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4361 PKT_END);
32874aea 4362 } else {
51470298 4363 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4364 PKT_STR, proto, PKT_STR, data, PKT_END);
4365 }
4366 do {
4367 crReturnV;
ff3187f6 4368 } while (!pktin);
4369 if (pktin->type != SSH1_SMSG_SUCCESS
4370 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4371 bombout(("Protocol confusion"));
7ffdbc1a 4372 crStopV;
ff3187f6 4373 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4374 logevent("X11 forwarding refused");
4375 } else {
4376 logevent("X11 forwarding enabled");
51470298 4377 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4378 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4379 }
4380 }
4381
06fadff5 4382 ssh_setup_portfwd(ssh, &ssh->cfg);
4383 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4384
86916870 4385 if (!ssh->cfg.nopty) {
a5dd8467 4386 /* Unpick the terminal-speed string. */
4387 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4388 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4389 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4390 /* Send the pty request. */
51470298 4391 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4392 PKT_STR, ssh->cfg.termtype,
51470298 4393 PKT_INT, ssh->term_height,
4394 PKT_INT, ssh->term_width,
a5dd8467 4395 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4396 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4397 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4398 PKT_CHAR, 0, PKT_END);
51470298 4399 ssh->state = SSH_STATE_INTERMED;
32874aea 4400 do {
4401 crReturnV;
ff3187f6 4402 } while (!pktin);
4403 if (pktin->type != SSH1_SMSG_SUCCESS
4404 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4405 bombout(("Protocol confusion"));
7ffdbc1a 4406 crStopV;
ff3187f6 4407 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4408 c_write_str(ssh, "Server refused to allocate pty\r\n");
4409 ssh->editing = ssh->echoing = 1;
32874aea 4410 }
a5dd8467 4411 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4412 ssh->ospeed, ssh->ispeed);
0965bee0 4413 } else {
51470298 4414 ssh->editing = ssh->echoing = 1;
374330e2 4415 }
4416
86916870 4417 if (ssh->cfg.compression) {
51470298 4418 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4419 do {
4420 crReturnV;
ff3187f6 4421 } while (!pktin);
4422 if (pktin->type != SSH1_SMSG_SUCCESS
4423 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4424 bombout(("Protocol confusion"));
7ffdbc1a 4425 crStopV;
ff3187f6 4426 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4427 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4428 }
4ba9b64b 4429 logevent("Started compression");
51470298 4430 ssh->v1_compressing = TRUE;
5366aed8 4431 ssh->cs_comp_ctx = zlib_compress_init();
4432 logevent("Initialised zlib (RFC1950) compression");
4433 ssh->sc_comp_ctx = zlib_decompress_init();
4434 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4435 }
4436
fd5e5847 4437 /*
4438 * Start the shell or command.
4439 *
4440 * Special case: if the first-choice command is an SSH2
4441 * subsystem (hence not usable here) and the second choice
4442 * exists, we fall straight back to that.
4443 */
4444 {
86916870 4445 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4446
86916870 4447 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4448 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4449 ssh->fallback_cmd = TRUE;
fd5e5847 4450 }
4451 if (*cmd)
51470298 4452 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4453 else
51470298 4454 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4455 logevent("Started session");
4456 }
374330e2 4457
51470298 4458 ssh->state = SSH_STATE_SESSION;
4459 if (ssh->size_needed)
4460 ssh_size(ssh, ssh->term_width, ssh->term_height);
4461 if (ssh->eof_needed)
4462 ssh_special(ssh, TS_EOF);
374330e2 4463
b9d7bcad 4464 if (ssh->ldisc)
4465 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4466 ssh->send_ok = 1;
4467 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4468 while (1) {
d74d141c 4469
51df0ab5 4470 /*
4471 * By this point, most incoming packets are already being
4472 * handled by the dispatch table, and we need only pay
4473 * attention to the unusual ones.
4474 */
0357890f 4475
51df0ab5 4476 crReturnV;
4477 if (pktin) {
4478 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4479 /* may be from EXEC_SHELL on some servers */
ff3187f6 4480 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4481 /* may be from EXEC_SHELL on some servers
374330e2 4482 * if no pty is available or in other odd cases. Ignore */
374330e2 4483 } else {
ff3187f6 4484 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4485 crStopV;
374330e2 4486 }
4487 } else {
8df7a775 4488 while (inlen > 0) {
4489 int len = min(inlen, 512);
9a10ecf4 4490 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4491 PKT_INT, len, PKT_DATA, in, len,
4492 PKTT_OTHER, PKT_END);
8df7a775 4493 in += len;
4494 inlen -= len;
4495 }
374330e2 4496 }
4497 }
4498
4499 crFinishV;
4500}
4501
4502/*
b09eaa88 4503 * Handle the top-level SSH2 protocol.
4504 */
4505static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4506{
4507 char *buf, *msg;
4508 int msglen;
4509
4510 ssh_pkt_getstring(pktin, &msg, &msglen);
4511 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4512 logevent(buf);
4513 sfree(buf);
4514}
4515
4516static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4517{
4518 /* log reason code in disconnect message */
4519 char *msg;
4520 int msglen;
4521
4522 ssh_pkt_getstring(pktin, &msg, &msglen);
4523 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4524}
4525
4526void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4527{
4528 /* Do nothing, because we're ignoring it! Duhh. */
4529}
4530
4531static void ssh1_protocol_setup(Ssh ssh)
4532{
4533 int i;
4534
4535 /*
4536 * Most messages are handled by the coroutines.
4537 */
4538 for (i = 0; i < 256; i++)
4539 ssh->packet_dispatch[i] = NULL;
4540
4541 /*
4542 * These special message types we install handlers for.
4543 */
4544 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4545 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4546 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4547}
4548
4549static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4550 struct Packet *pktin)
4551{
4552 if (ssh->state == SSH_STATE_CLOSED)
4553 return;
4554
4555 if (pktin && ssh->packet_dispatch[pktin->type]) {
4556 ssh->packet_dispatch[pktin->type](ssh, pktin);
4557 return;
4558 }
4559
4560 if (!ssh->protocol_initial_phase_done) {
4561 if (do_ssh1_login(ssh, in, inlen, pktin))
4562 ssh->protocol_initial_phase_done = TRUE;
4563 else
4564 return;
4565 }
4566
4567 do_ssh1_connection(ssh, in, inlen, pktin);
4568}
4569
4570/*
e5574168 4571 * Utility routine for decoding comma-separated strings in KEXINIT.
4572 */
32874aea 4573static int in_commasep_string(char *needle, char *haystack, int haylen)
4574{
57356d63 4575 int needlen;
4576 if (!needle || !haystack) /* protect against null pointers */
4577 return 0;
4578 needlen = strlen(needle);
e5574168 4579 while (1) {
32874aea 4580 /*
4581 * Is it at the start of the string?
4582 */
4583 if (haylen >= needlen && /* haystack is long enough */
4584 !memcmp(needle, haystack, needlen) && /* initial match */
4585 (haylen == needlen || haystack[needlen] == ',')
4586 /* either , or EOS follows */
4587 )
4588 return 1;
4589 /*
4590 * If not, search for the next comma and resume after that.
4591 * If no comma found, terminate.
4592 */
4593 while (haylen > 0 && *haystack != ',')
4594 haylen--, haystack++;
4595 if (haylen == 0)
4596 return 0;
4597 haylen--, haystack++; /* skip over comma itself */
e5574168 4598 }
4599}
4600
4601/*
d39f364a 4602 * SSH2 key creation method.
4603 */
d8baa528 4604static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4605 unsigned char *sessid, char chr,
4606 unsigned char *keyspace)
32874aea 4607{
d39f364a 4608 SHA_State s;
4609 /* First 20 bytes. */
4610 SHA_Init(&s);
51470298 4611 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4612 sha_mpint(&s, K);
d39f364a 4613 SHA_Bytes(&s, H, 20);
4614 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4615 SHA_Bytes(&s, sessid, 20);
d39f364a 4616 SHA_Final(&s, keyspace);
4617 /* Next 20 bytes. */
4618 SHA_Init(&s);
51470298 4619 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4620 sha_mpint(&s, K);
d39f364a 4621 SHA_Bytes(&s, H, 20);
4622 SHA_Bytes(&s, keyspace, 20);
32874aea 4623 SHA_Final(&s, keyspace + 20);
d39f364a 4624}
4625
4626/*
7cca0d81 4627 * Handle the SSH2 transport layer.
e5574168 4628 */
ff3187f6 4629static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4630 struct Packet *pktin)
e5574168 4631{
51470298 4632 struct do_ssh2_transport_state {
4633 int nbits, pbits, warn;
4634 Bignum p, g, e, f, K;
4635 int kex_init_value, kex_reply_value;
4636 const struct ssh_mac **maclist;
4637 int nmacs;
4638 const struct ssh2_cipher *cscipher_tobe;
4639 const struct ssh2_cipher *sccipher_tobe;
4640 const struct ssh_mac *csmac_tobe;
4641 const struct ssh_mac *scmac_tobe;
4642 const struct ssh_compress *cscomp_tobe;
4643 const struct ssh_compress *sccomp_tobe;
4644 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4645 int hostkeylen, siglen;
4646 void *hkey; /* actual host key */
4647 unsigned char exchange_hash[20];
83e7d008 4648 int n_preferred_kex;
4649 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4650 int n_preferred_ciphers;
4651 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4652 const struct ssh_compress *preferred_comp;
e13bba36 4653 int got_session_id, activated_authconn;
ff3187f6 4654 struct Packet *pktout;
51470298 4655 };
4656 crState(do_ssh2_transport_state);
4657
4658 crBegin(ssh->do_ssh2_transport_crstate);
4659
4660 s->cscipher_tobe = s->sccipher_tobe = NULL;
4661 s->csmac_tobe = s->scmac_tobe = NULL;
4662 s->cscomp_tobe = s->sccomp_tobe = NULL;
4663
e13bba36 4664 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4665
e13bba36 4666 /*
4667 * Be prepared to work around the buggy MAC problem.
4668 */
4669 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4670 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4671 else
4672 s->maclist = macs, s->nmacs = lenof(macs);
4673
4674 begin_key_exchange:
51470298 4675 {
e13bba36 4676 int i, j, commalist_started;
4677
51470298 4678 /*
83e7d008 4679 * Set up the preferred key exchange. (NULL => warn below here)
4680 */
4681 s->n_preferred_kex = 0;
4682 for (i = 0; i < KEX_MAX; i++) {
4683 switch (ssh->cfg.ssh_kexlist[i]) {
4684 case KEX_DHGEX:
4685 s->preferred_kex[s->n_preferred_kex++] =
4686 &ssh_diffiehellman_gex;
4687 break;
4688 case KEX_DHGROUP14:
4689 s->preferred_kex[s->n_preferred_kex++] =
4690 &ssh_diffiehellman_group14;
4691 break;
4692 case KEX_DHGROUP1:
4693 s->preferred_kex[s->n_preferred_kex++] =
4694 &ssh_diffiehellman_group1;
4695 break;
4696 case CIPHER_WARN:
4697 /* Flag for later. Don't bother if it's the last in
4698 * the list. */
4699 if (i < KEX_MAX - 1) {
4700 s->preferred_kex[s->n_preferred_kex++] = NULL;
4701 }
4702 break;
4703 }
4704 }
83e7d008 4705
83e7d008 4706 /*
51470298 4707 * Set up the preferred ciphers. (NULL => warn below here)
4708 */
4709 s->n_preferred_ciphers = 0;
4710 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4711 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4712 case CIPHER_BLOWFISH:
4713 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4714 break;
4715 case CIPHER_DES:
86916870 4716 if (ssh->cfg.ssh2_des_cbc) {
51470298 4717 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4718 }
4719 break;
4720 case CIPHER_3DES:
4721 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4722 break;
4723 case CIPHER_AES:
4724 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4725 break;
4726 case CIPHER_WARN:
4727 /* Flag for later. Don't bother if it's the last in
4728 * the list. */
4729 if (i < CIPHER_MAX - 1) {
4730 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4731 }
4732 break;
ca20bfcf 4733 }
ca20bfcf 4734 }
7591b9ff 4735
e13bba36 4736 /*
4737 * Set up preferred compression.
4738 */
4739 if (ssh->cfg.compression)
4740 s->preferred_comp = &ssh_zlib;
4741 else
4742 s->preferred_comp = &ssh_comp_none;
51470298 4743
4744 /*
590f6a5f 4745 * Enable queueing of outgoing auth- or connection-layer
4746 * packets while we are in the middle of a key exchange.
4747 */
4748 ssh->queueing = TRUE;
4749
4750 /*
9442dd57 4751 * Flag that KEX is in progress.
4752 */
4753 ssh->kex_in_progress = TRUE;
4754
4755 /*
51470298 4756 * Construct and send our key exchange packet.
4757 */
ff3187f6 4758 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4759 for (i = 0; i < 16; i++)
ff3187f6 4760 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4761 /* List key exchange algorithms. */
ff3187f6 4762 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4763 commalist_started = 0;
4764 for (i = 0; i < s->n_preferred_kex; i++) {
4765 const struct ssh_kex *k = s->preferred_kex[i];
4766 if (!k) continue; /* warning flag */
4767 if (commalist_started)
ff3187f6 4768 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4769 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4770 commalist_started = 1;
32874aea 4771 }
51470298 4772 /* List server host key algorithms. */
ff3187f6 4773 ssh2_pkt_addstring_start(s->pktout);
51470298 4774 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4775 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4776 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4777 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4778 }
51470298 4779 /* List client->server encryption algorithms. */
ff3187f6 4780 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4781 commalist_started = 0;
51470298 4782 for (i = 0; i < s->n_preferred_ciphers; i++) {
4783 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4784 if (!c) continue; /* warning flag */
4785 for (j = 0; j < c->nciphers; j++) {
83e7d008 4786 if (commalist_started)
ff3187f6 4787 ssh2_pkt_addstring_str(s->pktout, ",");
4788 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4789 commalist_started = 1;
51470298 4790 }
4791 }
4792 /* List server->client encryption algorithms. */
ff3187f6 4793 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4794 commalist_started = 0;
51470298 4795 for (i = 0; i < s->n_preferred_ciphers; i++) {
4796 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4797 if (!c) continue; /* warning flag */
4798 for (j = 0; j < c->nciphers; j++) {
83e7d008 4799 if (commalist_started)
ff3187f6 4800 ssh2_pkt_addstring_str(s->pktout, ",");
4801 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4802 commalist_started = 1;
51470298 4803 }
4804 }
4805 /* List client->server MAC algorithms. */
ff3187f6 4806 ssh2_pkt_addstring_start(s->pktout);
51470298 4807 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4808 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4809 if (i < s->nmacs - 1)
ff3187f6 4810 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4811 }
4812 /* List server->client MAC algorithms. */
ff3187f6 4813 ssh2_pkt_addstring_start(s->pktout);
51470298 4814 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4815 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4816 if (i < s->nmacs - 1)
ff3187f6 4817 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4818 }
4819 /* List client->server compression algorithms. */
ff3187f6 4820 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4821 assert(lenof(compressions) > 1);
ff3187f6 4822 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4823 for (i = 0; i < lenof(compressions); i++) {
4824 const struct ssh_compress *c = compressions[i];
4825 if (c != s->preferred_comp) {
ff3187f6 4826 ssh2_pkt_addstring_str(s->pktout, ",");
4827 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4828 }
51470298 4829 }
4830 /* List server->client compression algorithms. */
ff3187f6 4831 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4832 assert(lenof(compressions) > 1);
ff3187f6 4833 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4834 for (i = 0; i < lenof(compressions); i++) {
4835 const struct ssh_compress *c = compressions[i];
4836 if (c != s->preferred_comp) {
ff3187f6 4837 ssh2_pkt_addstring_str(s->pktout, ",");
4838 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4839 }
51470298 4840 }
4841 /* List client->server languages. Empty list. */
ff3187f6 4842 ssh2_pkt_addstring_start(s->pktout);
51470298 4843 /* List server->client languages. Empty list. */
ff3187f6 4844 ssh2_pkt_addstring_start(s->pktout);
51470298 4845 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4846 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4847 /* Reserved. */
ff3187f6 4848 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4849 }
0db56f73 4850
51470298 4851 ssh->exhash = ssh->exhashbase;
ff3187f6 4852 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4853
590f6a5f 4854 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4855
ff3187f6 4856 if (!pktin)
4857 crWaitUntil(pktin);
4858 if (pktin->length > 5)
4859 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4860
4861 /*
4862 * Now examine the other side's KEXINIT to see what we're up
4863 * to.
4864 */
51470298 4865 {
4866 char *str;
4867 int i, j, len;
4868
ff3187f6 4869 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4870 bombout(("expected key exchange packet from server"));
7ffdbc1a 4871 crStop(0);
32874aea 4872 }
51470298 4873 ssh->kex = NULL;
4874 ssh->hostkey = NULL;
4875 s->cscipher_tobe = NULL;
4876 s->sccipher_tobe = NULL;
4877 s->csmac_tobe = NULL;
4878 s->scmac_tobe = NULL;
4879 s->cscomp_tobe = NULL;
4880 s->sccomp_tobe = NULL;
ff3187f6 4881 pktin->savedpos += 16; /* skip garbage cookie */
4882 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4883 s->warn = 0;
4884 for (i = 0; i < s->n_preferred_kex; i++) {
4885 const struct ssh_kex *k = s->preferred_kex[i];
4886 if (!k) {
4887 s->warn = 1;
4888 } else if (in_commasep_string(k->name, str, len)) {
4889 ssh->kex = k;
4890 }
4891 if (ssh->kex) {
4892 if (s->warn)
4893 askalg(ssh->frontend, "key-exchange algorithm",
4894 ssh->kex->name);
51470298 4895 break;
4896 }
32874aea 4897 }
83e7d008 4898 if (!ssh->kex) {
4899 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4900 str ? str : "(null)"));
4901 crStop(0);
4902 }
ff3187f6 4903 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4904 for (i = 0; i < lenof(hostkey_algs); i++) {
4905 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4906 ssh->hostkey = hostkey_algs[i];
4907 break;
4908 }
4909 }
ff3187f6 4910 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4911 s->warn = 0;
4912 for (i = 0; i < s->n_preferred_ciphers; i++) {
4913 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4914 if (!c) {
4915 s->warn = 1;
4916 } else {
4917 for (j = 0; j < c->nciphers; j++) {
4918 if (in_commasep_string(c->list[j]->name, str, len)) {
4919 s->cscipher_tobe = c->list[j];
4920 break;
4921 }
ca20bfcf 4922 }
32874aea 4923 }
51470298 4924 if (s->cscipher_tobe) {
4925 if (s->warn)
83e7d008 4926 askalg(ssh->frontend, "client-to-server cipher",
4927 s->cscipher_tobe->name);
51470298 4928 break;
4929 }
32874aea 4930 }
51470298 4931 if (!s->cscipher_tobe) {
6b5cf8b4 4932 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4933 str ? str : "(null)"));
7ffdbc1a 4934 crStop(0);
ca20bfcf 4935 }
0ef8f407 4936
ff3187f6 4937 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4938 s->warn = 0;
4939 for (i = 0; i < s->n_preferred_ciphers; i++) {
4940 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4941 if (!c) {
4942 s->warn = 1;
4943 } else {
4944 for (j = 0; j < c->nciphers; j++) {
4945 if (in_commasep_string(c->list[j]->name, str, len)) {
4946 s->sccipher_tobe = c->list[j];
4947 break;
4948 }
ca20bfcf 4949 }
32874aea 4950 }
51470298 4951 if (s->sccipher_tobe) {
4952 if (s->warn)
83e7d008 4953 askalg(ssh->frontend, "server-to-client cipher",
4954 s->sccipher_tobe->name);
51470298 4955 break;
4956 }
32874aea 4957 }
51470298 4958 if (!s->sccipher_tobe) {
6b5cf8b4 4959 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4960 str ? str : "(null)"));
7ffdbc1a 4961 crStop(0);
ca20bfcf 4962 }
0ef8f407 4963
ff3187f6 4964 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4965 for (i = 0; i < s->nmacs; i++) {
4966 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4967 s->csmac_tobe = s->maclist[i];
4968 break;
4969 }
32874aea 4970 }
ff3187f6 4971 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4972 for (i = 0; i < s->nmacs; i++) {
4973 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4974 s->scmac_tobe = s->maclist[i];
4975 break;
4976 }
32874aea 4977 }
ff3187f6 4978 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4979 for (i = 0; i < lenof(compressions) + 1; i++) {
4980 const struct ssh_compress *c =
4981 i == 0 ? s->preferred_comp : compressions[i - 1];
4982 if (in_commasep_string(c->name, str, len)) {
4983 s->cscomp_tobe = c;
4984 break;
4985 }
32874aea 4986 }
ff3187f6 4987 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4988 for (i = 0; i < lenof(compressions) + 1; i++) {
4989 const struct ssh_compress *c =
4990 i == 0 ? s->preferred_comp : compressions[i - 1];
4991 if (in_commasep_string(c->name, str, len)) {
4992 s->sccomp_tobe = c;
4993 break;
4994 }
32874aea 4995 }
e5574168 4996 }
e5574168 4997
4998 /*
7bd5a860 4999 * Work out the number of bits of key we will need from the key
5000 * exchange. We start with the maximum key length of either
5001 * cipher...
5002 */
5003 {
32874aea 5004 int csbits, scbits;
7bd5a860 5005
51470298 5006 csbits = s->cscipher_tobe->keylen;
5007 scbits = s->sccipher_tobe->keylen;
5008 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5009 }
5010 /* The keys only have 160-bit entropy, since they're based on
5011 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5012 if (s->nbits > 160)
5013 s->nbits = 160;
7bd5a860 5014
5015 /*
a92dd380 5016 * If we're doing Diffie-Hellman group exchange, start by
5017 * requesting a group.
e5574168 5018 */
d1aaf71d 5019 if (!ssh->kex->pdata) {
32874aea 5020 logevent("Doing Diffie-Hellman group exchange");
51470298 5021 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5022 /*
5023 * Work out how big a DH group we will need to allow that
5024 * much data.
7bd5a860 5025 */
51470298 5026 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5027 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5028 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5029 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5030
ff3187f6 5031 crWaitUntil(pktin);
5032 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5033 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5034 crStop(0);
32874aea 5035 }
ff3187f6 5036 s->p = ssh2_pkt_getmp(pktin);
5037 s->g = ssh2_pkt_getmp(pktin);
5038 if (!s->p || !s->g) {
5039 bombout(("unable to read mp-ints from incoming group packet"));
5040 crStop(0);
5041 }
d1aaf71d 5042 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5043 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5044 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5045 } else {
d1aaf71d 5046 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5047 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5048 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5049 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5050 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5051 ssh->kex->groupname);
8d5de777 5052 }
e5574168 5053
a92dd380 5054 logevent("Doing Diffie-Hellman key exchange");
e5574168 5055 /*
a92dd380 5056 * Now generate and send e for Diffie-Hellman.
e5574168 5057 */
27cd7fc2 5058 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5059 s->pktout = ssh2_pkt_init(s->kex_init_value);
5060 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5061 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5062
ff3187f6 5063 crWaitUntil(pktin);
5064 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5065 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5066 crStop(0);
7cca0d81 5067 }
ff3187f6 5068 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5069 s->f = ssh2_pkt_getmp(pktin);
5070 if (!s->f) {
5071 bombout(("unable to parse key exchange reply packet"));
5072 crStop(0);
5073 }
5074 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5075
27cd7fc2 5076 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5077
51470298 5078 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5079 if (ssh->kex == &ssh_diffiehellman_gex) {
5080 sha_uint32(&ssh->exhash, s->pbits);
5081 sha_mpint(&ssh->exhash, s->p);
5082 sha_mpint(&ssh->exhash, s->g);
a92dd380 5083 }
51470298 5084 sha_mpint(&ssh->exhash, s->e);
5085 sha_mpint(&ssh->exhash, s->f);
5086 sha_mpint(&ssh->exhash, s->K);
5087 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5088
27cd7fc2 5089 dh_cleanup(ssh->kex_ctx);
fabd1805 5090 ssh->kex_ctx = NULL;
3709bfe9 5091
7cca0d81 5092#if 0
765c4200 5093 debug(("Exchange hash is:\n"));
51470298 5094 dmemdump(s->exchange_hash, 20);
7cca0d81 5095#endif
5096
51470298 5097 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5098 if (!s->hkey ||
5099 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5100 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5101 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5102 crStop(0);
8d5de777 5103 }
e5574168 5104
5105 /*
7cca0d81 5106 * Authenticate remote host: verify host key. (We've already
5107 * checked the signature of the exchange hash.)
e5574168 5108 */
51470298 5109 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5110 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 5111 verify_ssh_host_key(ssh->frontend,
5112 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5113 s->keystr, s->fingerprint);
e13bba36 5114 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5115 logevent("Host key fingerprint is:");
51470298 5116 logevent(s->fingerprint);
5e0d7cb8 5117 }
51470298 5118 sfree(s->fingerprint);
5119 sfree(s->keystr);
5120 ssh->hostkey->freekey(s->hkey);
d39f364a 5121
5122 /*
9442dd57 5123 * The exchange hash from the very first key exchange is also
5124 * the session id, used in session key construction and
5125 * authentication.
5126 */
e13bba36 5127 if (!s->got_session_id) {
9442dd57 5128 memcpy(ssh->v2_session_id, s->exchange_hash,
5129 sizeof(s->exchange_hash));
e13bba36 5130 s->got_session_id = TRUE;
5131 }
9442dd57 5132
5133 /*
7cca0d81 5134 * Send SSH2_MSG_NEWKEYS.
d39f364a 5135 */
ff3187f6 5136 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5137 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5138 ssh->outgoing_data_size = 0; /* start counting from here */
5139
5140 /*
5141 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5142 * client-to-server session keys.
9442dd57 5143 */
5144 if (ssh->cs_cipher_ctx)
5145 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5146 ssh->cscipher = s->cscipher_tobe;
5147 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5148
5149 if (ssh->cs_mac_ctx)
5150 ssh->csmac->free_context(ssh->cs_mac_ctx);
5151 ssh->csmac = s->csmac_tobe;
5152 ssh->cs_mac_ctx = ssh->csmac->make_context();
5153
5154 if (ssh->cs_comp_ctx)
5155 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5156 ssh->cscomp = s->cscomp_tobe;
5157 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5158
5159 /*
5160 * Set IVs on client-to-server keys. Here we use the exchange
5161 * hash from the _first_ key exchange.
5162 */
5163 {
5164 unsigned char keyspace[40];
5165 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5166 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5167 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5168 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5169 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5170 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5171 }
5172
5173 logeventf(ssh, "Initialised %.200s client->server encryption",
5174 ssh->cscipher->text_name);
5175 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5176 ssh->csmac->text_name);
5177 if (ssh->cscomp->text_name)
5178 logeventf(ssh, "Initialised %s compression",
5179 ssh->cscomp->text_name);
590f6a5f 5180
5181 /*
5182 * Now our end of the key exchange is complete, we can send all
5183 * our queued higher-layer packets.
5184 */
5185 ssh->queueing = FALSE;
5186 ssh2_pkt_queuesend(ssh);
d39f364a 5187
5188 /*
8406eaf9 5189 * Expect SSH2_MSG_NEWKEYS from server.
5190 */
ff3187f6 5191 crWaitUntil(pktin);
5192 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5193 bombout(("expected new-keys packet from server"));
7ffdbc1a 5194 crStop(0);
8406eaf9 5195 }
9442dd57 5196 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5197
5198 /*
9442dd57 5199 * We've seen server NEWKEYS, so create and initialise
5200 * server-to-client session keys.
d39f364a 5201 */
371e569c 5202 if (ssh->sc_cipher_ctx)
5203 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5204 ssh->sccipher = s->sccipher_tobe;
371e569c 5205 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5206
e0e1a00d 5207 if (ssh->sc_mac_ctx)
5208 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5209 ssh->scmac = s->scmac_tobe;
e0e1a00d 5210 ssh->sc_mac_ctx = ssh->scmac->make_context();
5211
5366aed8 5212 if (ssh->sc_comp_ctx)
5213 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5214 ssh->sccomp = s->sccomp_tobe;
5366aed8 5215 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5216
d39f364a 5217 /*
9442dd57 5218 * Set IVs on server-to-client keys. Here we use the exchange
5219 * hash from the _first_ key exchange.
d39f364a 5220 */
51470298 5221 {
5222 unsigned char keyspace[40];
51470298 5223 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5224 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5225 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5226 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5227 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5228 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5229 }
57356d63 5230 logeventf(ssh, "Initialised %.200s server->client encryption",
5231 ssh->sccipher->text_name);
6c135243 5232 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5233 ssh->scmac->text_name);
57356d63 5234 if (ssh->sccomp->text_name)
5235 logeventf(ssh, "Initialised %s decompression",
5236 ssh->sccomp->text_name);
9442dd57 5237
5238 /*
5239 * Free key exchange data.
5240 */
679539d7 5241 freebn(s->f);
679539d7 5242 freebn(s->K);
b3949e7e 5243 if (ssh->kex == &ssh_diffiehellman_gex) {
5244 freebn(s->g);
5245 freebn(s->p);
5246 }
d39f364a 5247
033b4cef 5248 /*
e13bba36 5249 * Key exchange is over. Loop straight back round if we have a
5250 * deferred rekey reason.
5251 */
5252 if (ssh->deferred_rekey_reason) {
5253 logevent(ssh->deferred_rekey_reason);
5254 pktin = NULL;
5255 ssh->deferred_rekey_reason = NULL;
5256 goto begin_key_exchange;
5257 }
5258
5259 /*
5260 * Otherwise, schedule a timer for our next rekey.
9442dd57 5261 */
5262 ssh->kex_in_progress = FALSE;
e6c1536e 5263 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5264 if (ssh->cfg.ssh_rekey_time != 0)
5265 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5266 ssh2_timer, ssh);
e13bba36 5267
9442dd57 5268 /*
0db56f73 5269 * If this is the first key exchange phase, we must pass the
5270 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5271 * wants to see it but because it will need time to initialise
5272 * itself before it sees an actual packet. In subsequent key
5273 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5274 * it would only confuse the layer above.
5275 */
e13bba36 5276 if (s->activated_authconn) {
b09eaa88 5277 crReturn(1);
0db56f73 5278 }
e13bba36 5279 s->activated_authconn = TRUE;
0db56f73 5280
5281 /*
7cca0d81 5282 * Now we're encrypting. Begin returning 1 to the protocol main
5283 * function so that other things can run on top of the
5284 * transport. If we ever see a KEXINIT, we must go back to the
5285 * start.
9442dd57 5286 *
5287 * We _also_ go back to the start if we see pktin==NULL and
5288 * inlen==-1, because this is a special signal meaning
5289 * `initiate client-driven rekey', and `in' contains a message
5290 * giving the reason for the rekey.
033b4cef 5291 */
9442dd57 5292 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5293 (!pktin && inlen == -1))) {
32874aea 5294 crReturn(1);
e96adf72 5295 }
9442dd57 5296 if (pktin) {
5297 logevent("Server initiated key re-exchange");
5298 } else {
5299 logevent((char *)in);
5300 }
7cca0d81 5301 goto begin_key_exchange;
e5574168 5302
5303 crFinish(1);
5304}
5305
7cca0d81 5306/*
783415f8 5307 * Add data to an SSH2 channel output buffer.
5308 */
32874aea 5309static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5310 int len)
5311{
5471d09a 5312 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5313}
5314
5315/*
5316 * Attempt to send data on an SSH2 channel.
5317 */
5471d09a 5318static int ssh2_try_send(struct ssh_channel *c)
32874aea 5319{
51470298 5320 Ssh ssh = c->ssh;
ff3187f6 5321 struct Packet *pktout;
51470298 5322
5471d09a 5323 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5324 int len;
5325 void *data;
5326 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5327 if ((unsigned)len > c->v.v2.remwindow)
5328 len = c->v.v2.remwindow;
5329 if ((unsigned)len > c->v.v2.remmaxpkt)
5330 len = c->v.v2.remmaxpkt;
ff3187f6 5331 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5332 ssh2_pkt_adduint32(pktout, c->remoteid);
5333 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5334 ssh2_pkt_addstring_start(pktout);
5335 ssh2_pkt_addstring_data(pktout, data, len);
5336 end_log_omission(ssh, pktout);
5337 ssh2_pkt_send(ssh, pktout);
5471d09a 5338 bufchain_consume(&c->v.v2.outbuffer, len);
5339 c->v.v2.remwindow -= len;
5340 }
5341
5342 /*
5343 * After having sent as much data as we can, return the amount
5344 * still buffered.
5345 */
5346 return bufchain_size(&c->v.v2.outbuffer);
5347}
5348
5349/*
5350 * Potentially enlarge the window on an SSH2 channel.
5351 */
5352static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5353{
51470298 5354 Ssh ssh = c->ssh;
5355
6b69f42e 5356 /*
5357 * Never send WINDOW_ADJUST for a channel that the remote side
5358 * already thinks it's closed; there's no point, since it won't
5359 * be sending any more data anyway.
5360 */
5361 if (c->closes != 0)
5362 return;
5363
5471d09a 5364 if (newwin > c->v.v2.locwindow) {
ff3187f6 5365 struct Packet *pktout;
5366
5367 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5368 ssh2_pkt_adduint32(pktout, c->remoteid);
5369 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5370 ssh2_pkt_send(ssh, pktout);
5471d09a 5371 c->v.v2.locwindow = newwin;
783415f8 5372 }
5373}
5374
51df0ab5 5375static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5376{
5377 unsigned i = ssh_pkt_getuint32(pktin);
5378 struct ssh_channel *c;
5379 c = find234(ssh->channels, &i, ssh_channelfind);
5380 if (c && !c->closes)
5381 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5382}
5383
51df0ab5 5384static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5385{
5386 char *data;
aa63ab7e 5387 unsigned int length;
51df0ab5 5388 unsigned i = ssh_pkt_getuint32(pktin);
5389 struct ssh_channel *c;
5390 c = find234(ssh->channels, &i, ssh_channelfind);
5391 if (!c)
5392 return; /* nonexistent channel */
5393 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5394 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5395 return; /* extended but not stderr */
5396 ssh_pkt_getstring(pktin, &data, &length);
5397 if (data) {
5398 int bufsize = 0;
5399 c->v.v2.locwindow -= length;
5400 switch (c->type) {
5401 case CHAN_MAINSESSION:
5402 bufsize =
5403 from_backend(ssh->frontend, pktin->type ==
5404 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5405 data, length);
5406 break;
5407 case CHAN_X11:
5408 bufsize = x11_send(c->u.x11.s, data, length);
5409 break;
5410 case CHAN_SOCKDATA:
5411 bufsize = pfd_send(c->u.pfd.s, data, length);
5412 break;
5413 case CHAN_AGENT:
5414 while (length > 0) {
5415 if (c->u.a.lensofar < 4) {
aa63ab7e 5416 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5417 memcpy(c->u.a.msglen + c->u.a.lensofar,
5418 data, l);
5419 data += l;
5420 length -= l;
5421 c->u.a.lensofar += l;
5422 }
5423 if (c->u.a.lensofar == 4) {
5424 c->u.a.totallen =
5425 4 + GET_32BIT(c->u.a.msglen);
5426 c->u.a.message = snewn(c->u.a.totallen,
5427 unsigned char);
5428 memcpy(c->u.a.message, c->u.a.msglen, 4);
5429 }
5430 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5431 unsigned int l =
51df0ab5 5432 min(c->u.a.totallen - c->u.a.lensofar,
5433 length);
5434 memcpy(c->u.a.message + c->u.a.lensofar,
5435 data, l);
5436 data += l;
5437 length -= l;
5438 c->u.a.lensofar += l;
5439 }
5440 if (c->u.a.lensofar == c->u.a.totallen) {
5441 void *reply;
5442 int replylen;
5443 if (agent_query(c->u.a.message,
5444 c->u.a.totallen,
5445 &reply, &replylen,
5446 ssh_agentf_callback, c))
5447 ssh_agentf_callback(c, reply, replylen);
5448 sfree(c->u.a.message);
5449 c->u.a.lensofar = 0;
5450 }
5451 }
5452 bufsize = 0;
5453 break;
5454 }
5455 /*
5456 * If we are not buffering too much data,
5457 * enlarge the window again at the remote side.
5458 */
5459 if (bufsize < OUR_V2_WINSIZE)
5460 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5461 }
5462}
5463
5464static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5465{
5466 unsigned i = ssh_pkt_getuint32(pktin);
5467 struct ssh_channel *c;
5468
5469 c = find234(ssh->channels, &i, ssh_channelfind);
5470 if (!c)
5471 return; /* nonexistent channel */
5472
5473 if (c->type == CHAN_X11) {
5474 /*
5475 * Remote EOF on an X11 channel means we should
5476 * wrap up and close the channel ourselves.
5477 */
5478 x11_close(c->u.x11.s);
5479 sshfwd_close(c);
5480 } else if (c->type == CHAN_AGENT) {
5481 sshfwd_close(c);
5482 } else if (c->type == CHAN_SOCKDATA) {
5483 pfd_close(c->u.pfd.s);
5484 sshfwd_close(c);
5485 }
5486}
5487
5488static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5489{
5490 unsigned i = ssh_pkt_getuint32(pktin);
5491 struct ssh_channel *c;
5492 struct Packet *pktout;
5493
5494 c = find234(ssh->channels, &i, ssh_channelfind);
5495 if (!c || ((int)c->remoteid) == -1) {
5496 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5497 c ? "half-open" : "nonexistent", i));
5498 return;
5499 }
5500 /* Do pre-close processing on the channel. */
5501 switch (c->type) {
5502 case CHAN_MAINSESSION:
5503 ssh->mainchan = NULL;
5504 update_specials_menu(ssh->frontend);
5505 break;
5506 case CHAN_X11:
5507 if (c->u.x11.s != NULL)
5508 x11_close(c->u.x11.s);
5509 sshfwd_close(c);
5510 break;
5511 case CHAN_AGENT:
5512 sshfwd_close(c);
5513 break;
5514 case CHAN_SOCKDATA:
5515 if (c->u.pfd.s != NULL)
5516 pfd_close(c->u.pfd.s);
5517 sshfwd_close(c);
5518 break;
5519 }
5520 if (c->closes == 0) {
5521 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5522 ssh2_pkt_adduint32(pktout, c->remoteid);
5523 ssh2_pkt_send(ssh, pktout);
5524 }
5525 del234(ssh->channels, c);
5526 bufchain_clear(&c->v.v2.outbuffer);
5527 sfree(c);
5528
5529 /*
5530 * See if that was the last channel left open.
5531 * (This is only our termination condition if we're
5532 * not running in -N mode.)
5533 */
5534 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5535 logevent("All channels closed. Disconnecting");
5536#if 0
5537 /*
5538 * We used to send SSH_MSG_DISCONNECT here,
5539 * because I'd believed that _every_ conforming
5540 * SSH2 connection had to end with a disconnect
5541 * being sent by at least one side; apparently
5542 * I was wrong and it's perfectly OK to
5543 * unceremoniously slam the connection shut
5544 * when you're done, and indeed OpenSSH feels
5545 * this is more polite than sending a
5546 * DISCONNECT. So now we don't.
5547 */
5548 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5549 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5550 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5551 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5552 ssh2_pkt_send_noqueue(ssh, s->pktout);
5553#endif
5554 ssh_closing((Plug)ssh, NULL, 0, 0);
5555 }
5556}
5557
5558static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5559{
5560 unsigned i = ssh_pkt_getuint32(pktin);
5561 struct ssh_channel *c;
5562 struct Packet *pktout;
5563
5564 c = find234(ssh->channels, &i, ssh_channelfind);
5565 if (!c)
5566 return; /* nonexistent channel */
5567 if (c->type != CHAN_SOCKDATA_DORMANT)
5568 return; /* dunno why they're confirming this */
5569 c->remoteid = ssh_pkt_getuint32(pktin);
5570 c->type = CHAN_SOCKDATA;
5571 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5572 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5573 if (c->u.pfd.s)
5574 pfd_confirm(c->u.pfd.s);
5575 if (c->closes) {
5576 /*
5577 * We have a pending close on this channel,
5578 * which we decided on before the server acked
5579 * the channel open. So now we know the
5580 * remoteid, we can close it again.
5581 */
5582 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5583 ssh2_pkt_adduint32(pktout, c->remoteid);
5584 ssh2_pkt_send(ssh, pktout);
5585 }
5586}
5587
5588static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5589{
5590 static const char *const reasons[] = {
5591 "<unknown reason code>",
5592 "Administratively prohibited",
5593 "Connect failed",
5594 "Unknown channel type",
5595 "Resource shortage",
5596 };
5597 unsigned i = ssh_pkt_getuint32(pktin);
5598 unsigned reason_code;
5599 char *reason_string;
5600 int reason_length;
5601 char *message;
5602 struct ssh_channel *c;
5603 c = find234(ssh->channels, &i, ssh_channelfind);
5604 if (!c)
5605 return; /* nonexistent channel */
5606 if (c->type != CHAN_SOCKDATA_DORMANT)
5607 return; /* dunno why they're failing this */
5608
5609 reason_code = ssh_pkt_getuint32(pktin);
5610 if (reason_code >= lenof(reasons))
5611 reason_code = 0; /* ensure reasons[reason_code] in range */
5612 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5613 message = dupprintf("Forwarded connection refused by"
5614 " server: %s [%.*s]", reasons[reason_code],
5615 reason_length, reason_string);
5616 logevent(message);
5617 sfree(message);
5618
5619 pfd_close(c->u.pfd.s);
5620
5621 del234(ssh->channels, c);
5622 sfree(c);
5623}
5624
5625static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5626{
5627 unsigned localid;
5628 char *type;
5629 int typelen, want_reply;
5630 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5631 struct ssh_channel *c;
5632 struct Packet *pktout;
5633
5634 localid = ssh_pkt_getuint32(pktin);
5635 ssh_pkt_getstring(pktin, &type, &typelen);
5636 want_reply = ssh2_pkt_getbool(pktin);
5637
5638 /*
5639 * First, check that the channel exists. Otherwise,
5640 * we can instantly disconnect with a rude message.
5641 */
5642 c = find234(ssh->channels, &localid, ssh_channelfind);
5643 if (!c) {
5644 char buf[80];
5645 sprintf(buf, "Received channel request for nonexistent"
5646 " channel %d", localid);
5647 logevent(buf);
5648 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5649 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5650 ssh2_pkt_addstring(pktout, buf);
5651 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5652 ssh2_pkt_send_noqueue(ssh, pktout);
5653 connection_fatal(ssh->frontend, "%s", buf);
5654 ssh_closing((Plug)ssh, NULL, 0, 0);
5655 return;
5656 }
5657
5658 /*
5659 * Having got the channel number, we now look at
5660 * the request type string to see if it's something
5661 * we recognise.
5662 */
5663 if (c == ssh->mainchan) {
5664 /*
5665 * We recognise "exit-status" and "exit-signal" on
5666 * the primary channel.
5667 */
5668 if (typelen == 11 &&
5669 !memcmp(type, "exit-status", 11)) {
5670
5671 ssh->exitcode = ssh_pkt_getuint32(pktin);
5672 logeventf(ssh, "Server sent command exit status %d",
5673 ssh->exitcode);
5674 reply = SSH2_MSG_CHANNEL_SUCCESS;
5675
5676 } else if (typelen == 11 &&
5677 !memcmp(type, "exit-signal", 11)) {
5678
5679 int is_plausible = TRUE, is_int = FALSE;
5680 char *fmt_sig = "", *fmt_msg = "";
5681 char *msg;
5682 int msglen = 0, core = FALSE;
5683 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5684 * provide an `int' for the signal, despite its
5685 * having been a `string' in the drafts since at
5686 * least 2001. (Fixed in session.c 1.147.) Try to
5687 * infer which we can safely parse it as. */
5688 {
5689 unsigned char *p = pktin->body +
5690 pktin->savedpos;
5691 long len = pktin->length - pktin->savedpos;
5692 unsigned long num = GET_32BIT(p); /* what is it? */
5693 /* If it's 0, it hardly matters; assume string */
5694 if (num == 0) {
5695 is_int = FALSE;
5696 } else {
5697 int maybe_int = FALSE, maybe_str = FALSE;
5698#define CHECK_HYPOTHESIS(offset, result) \
5699 do { \
5700 long q = offset; \
5701 if (q >= 0 && q+4 <= len) { \
5702 q = q + 4 + GET_32BIT(p+q); \
5703 if (q >= 0 && q+4 <= len && \
5704 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5705 result = TRUE; \
5706 } \
5707 } while(0)
5708 CHECK_HYPOTHESIS(4+1, maybe_int);
5709 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5710#undef CHECK_HYPOTHESIS
5711 if (maybe_int && !maybe_str)
5712 is_int = TRUE;
5713 else if (!maybe_int && maybe_str)
5714 is_int = FALSE;
5715 else
5716 /* Crikey. Either or neither. Panic. */
5717 is_plausible = FALSE;
5718 }
5719 }
5720 if (is_plausible) {
5721 if (is_int) {
5722 /* Old non-standard OpenSSH. */
5723 int signum = ssh_pkt_getuint32(pktin);
5724 fmt_sig = dupprintf(" %d", signum);
5725 } else {
5726 /* As per the drafts. */
5727 char *sig;
5728 int siglen;
5729 ssh_pkt_getstring(pktin, &sig, &siglen);
5730 /* Signal name isn't supposed to be blank, but
5731 * let's cope gracefully if it is. */
5732 if (siglen) {
5733 fmt_sig = dupprintf(" \"%.*s\"",
5734 siglen, sig);
5735 }
5736 }
5737 core = ssh2_pkt_getbool(pktin);
5738 ssh_pkt_getstring(pktin, &msg, &msglen);
5739 if (msglen) {
5740 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5741 }
5742 /* ignore lang tag */
5743 } /* else don't attempt to parse */
5744 logeventf(ssh, "Server exited on signal%s%s%s",
5745 fmt_sig, core ? " (core dumped)" : "",
5746 fmt_msg);
5747 if (*fmt_sig) sfree(fmt_sig);
5748 if (*fmt_msg) sfree(fmt_msg);
5749 reply = SSH2_MSG_CHANNEL_SUCCESS;
5750
5751 }
5752 } else {
5753 /*
5754 * This is a channel request we don't know
5755 * about, so we now either ignore the request
5756 * or respond with CHANNEL_FAILURE, depending
5757 * on want_reply.
5758 */
5759 reply = SSH2_MSG_CHANNEL_FAILURE;
5760 }
5761 if (want_reply) {
5762 pktout = ssh2_pkt_init(reply);
5763 ssh2_pkt_adduint32(pktout, c->remoteid);
5764 ssh2_pkt_send(ssh, pktout);
5765 }
5766}
5767
5768static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5769{
5770 char *type;
5771 int typelen, want_reply;
5772 struct Packet *pktout;
5773
5774 ssh_pkt_getstring(pktin, &type, &typelen);
5775 want_reply = ssh2_pkt_getbool(pktin);
5776
5777 /*
5778 * We currently don't support any global requests
5779 * at all, so we either ignore the request or
5780 * respond with REQUEST_FAILURE, depending on
5781 * want_reply.
5782 */
5783 if (want_reply) {
5784 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5785 ssh2_pkt_send(ssh, pktout);
5786 }
5787}
5788
5789static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5790{
5791 char *type;
5792 int typelen;
5793 char *peeraddr;
5794 int peeraddrlen;
5795 int peerport;
5796 char *error = NULL;
5797 struct ssh_channel *c;
5798 unsigned remid, winsize, pktsize;
5799 struct Packet *pktout;
5800
5801 ssh_pkt_getstring(pktin, &type, &typelen);
5802 c = snew(struct ssh_channel);
5803 c->ssh = ssh;
5804
5805 remid = ssh_pkt_getuint32(pktin);
5806 winsize = ssh_pkt_getuint32(pktin);
5807 pktsize = ssh_pkt_getuint32(pktin);
5808
5809 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5810 char *addrstr;
5811
5812 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5813 addrstr = snewn(peeraddrlen+1, char);
5814 memcpy(addrstr, peeraddr, peeraddrlen);
5815 addrstr[peeraddrlen] = '\0';
5816 peerport = ssh_pkt_getuint32(pktin);
5817
5818 logeventf(ssh, "Received X11 connect request from %s:%d",
5819 addrstr, peerport);
5820
5821 if (!ssh->X11_fwd_enabled)
5822 error = "X11 forwarding is not enabled";
5823 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5824 ssh->x11auth, addrstr, peerport,
5825 &ssh->cfg) != NULL) {
5826 error = "Unable to open an X11 connection";
5827 } else {
5828 logevent("Opening X11 forward connection succeeded");
5829 c->type = CHAN_X11;
5830 }
5831
5832 sfree(addrstr);
5833 } else if (typelen == 15 &&
5834 !memcmp(type, "forwarded-tcpip", 15)) {
5835 struct ssh_rportfwd pf, *realpf;
5836 char *dummy;
5837 int dummylen;
5838 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5839 pf.sport = ssh_pkt_getuint32(pktin);
5840 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5841 peerport = ssh_pkt_getuint32(pktin);
5842 realpf = find234(ssh->rportfwds, &pf, NULL);
5843 logeventf(ssh, "Received remote port %d open request "
5844 "from %s:%d", pf.sport, peeraddr, peerport);
5845 if (realpf == NULL) {
5846 error = "Remote port is not recognised";
5847 } else {
5848 const char *e = pfd_newconnect(&c->u.pfd.s,
5849 realpf->dhost,
5850 realpf->dport, c,
05581745 5851 &ssh->cfg,
5852 realpf->pfrec->addressfamily);
51df0ab5 5853 logeventf(ssh, "Attempting to forward remote port to "
5854 "%s:%d", realpf->dhost, realpf->dport);
5855 if (e != NULL) {
5856 logeventf(ssh, "Port open failed: %s", e);
5857 error = "Port open failed";
5858 } else {
5859 logevent("Forwarded port opened successfully");
5860 c->type = CHAN_SOCKDATA;
5861 }
5862 }
5863 } else if (typelen == 22 &&
5864 !memcmp(type, "auth-agent@openssh.com", 3)) {
5865 if (!ssh->agentfwd_enabled)
5866 error = "Agent forwarding is not enabled";
5867 else {
5868 c->type = CHAN_AGENT; /* identify channel type */
5869 c->u.a.lensofar = 0;
5870 }
5871 } else {
5872 error = "Unsupported channel type requested";
5873 }
5874
5875 c->remoteid = remid;
5876 if (error) {
5877 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5878 ssh2_pkt_adduint32(pktout, c->remoteid);
5879 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5880 ssh2_pkt_addstring(pktout, error);
5881 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5882 ssh2_pkt_send(ssh, pktout);
5883 logeventf(ssh, "Rejected channel open: %s", error);
5884 sfree(c);
5885 } else {
5886 c->localid = alloc_channel_id(ssh);
5887 c->closes = 0;
5888 c->v.v2.locwindow = OUR_V2_WINSIZE;
5889 c->v.v2.remwindow = winsize;
5890 c->v.v2.remmaxpkt = pktsize;
5891 bufchain_init(&c->v.v2.outbuffer);
5892 add234(ssh->channels, c);
5893 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5894 ssh2_pkt_adduint32(pktout, c->remoteid);
5895 ssh2_pkt_adduint32(pktout, c->localid);
5896 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5897 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5898 ssh2_pkt_send(ssh, pktout);
5899 }
5900}
5901
783415f8 5902/*
7cca0d81 5903 * Handle the SSH2 userauth and connection layers.
5904 */
ff3187f6 5905static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5906 struct Packet *pktin)
7cca0d81 5907{
51470298 5908 struct do_ssh2_authconn_state {
5909 enum {
5910 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5911 AUTH_PASSWORD,
5912 AUTH_KEYBOARD_INTERACTIVE
5913 } method;
5914 enum {
5915 AUTH_TYPE_NONE,
5916 AUTH_TYPE_PUBLICKEY,
5917 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5918 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5919 AUTH_TYPE_PASSWORD,
5920 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5921 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5922 } type;
5923 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 5924 int tried_pubkey_config, tried_agent;
5925 int kbd_inter_running, kbd_inter_refused;
51470298 5926 int we_are_in;
5927 int num_prompts, curr_prompt, echo;
5928 char username[100];
5929 int got_username;
85fdbe25 5930 char pwprompt[512];
51470298 5931 char password[100];
5932 void *publickey_blob;
5933 int publickey_bloblen;
5934 unsigned char request[5], *response, *p;
5935 int responselen;
5936 int keyi, nkeys;
5937 int authed;
5938 char *pkblob, *alg, *commentp;
5939 int pklen, alglen, commentlen;
5940 int siglen, retlen, len;
5941 char *q, *agentreq, *ret;
5942 int try_send;
73feed4f 5943 int num_env, env_left, env_ok;
ff3187f6 5944 struct Packet *pktout;
51470298 5945 };
5946 crState(do_ssh2_authconn_state);
5947
5948 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5949
7cca0d81 5950 /*
5951 * Request userauth protocol, and await a response to it.
5952 */
ff3187f6 5953 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5954 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5955 ssh2_pkt_send(ssh, s->pktout);
5956 crWaitUntilV(pktin);
5957 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5958 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5959 crStopV;
8d5de777 5960 }
7cca0d81 5961
5962 /*
1408a877 5963 * We repeat this whole loop, including the username prompt,
5964 * until we manage a successful authentication. If the user
51470298 5965 * types the wrong _password_, they can be sent back to the
5966 * beginning to try another username, if this is configured on.
5967 * (If they specify a username in the config, they are never
5968 * asked, even if they do give a wrong password.)
1408a877 5969 *
5970 * I think this best serves the needs of
5971 *
5972 * - the people who have no configuration, no keys, and just
5973 * want to try repeated (username,password) pairs until they
5974 * type both correctly
5975 *
5976 * - people who have keys and configuration but occasionally
5977 * need to fall back to passwords
5978 *
5979 * - people with a key held in Pageant, who might not have
5980 * logged in to a particular machine before; so they want to
5981 * type a username, and then _either_ their key will be
5982 * accepted, _or_ they will type a password. If they mistype
5983 * the username they will want to be able to get back and
5984 * retype it!
7cca0d81 5985 */
51470298 5986 s->username[0] = '\0';
5987 s->got_username = FALSE;
1408a877 5988 do {
1408a877 5989 /*
5990 * Get a username.
5991 */
86916870 5992 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5993 /*
5994 * We got a username last time round this loop, and
5995 * with change_username turned off we don't try to get
5996 * it again.
5997 */
aa09f7d0 5998 } else if (!*ssh->cfg.username) {
c0a81592 5999 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6000 if (!ssh_get_line("login as: ",
51470298 6001 s->username, sizeof(s->username), FALSE)) {
32874aea 6002 /*
6003 * get_line failed to get a username.
6004 * Terminate.
6005 */
6006 logevent("No username provided. Abandoning session.");
3bb2f322 6007 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6008 crStopV;
32874aea 6009 }
6010 } else {
51470298 6011 int ret; /* need not be saved across crReturn */
6012 c_write_str(ssh, "login as: ");
6013 ssh->send_ok = 1;
6014 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6015 do {
ff3187f6 6016 crWaitUntilV(!pktin);
51470298 6017 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6018 } while (ret == 0);
6019 if (ret < 0)
6020 cleanup_exit(0);
4ca0c9d1 6021 c_write_str(ssh, "\r\n");
32874aea 6022 }
51470298 6023 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6024 } else {
57356d63 6025 char *stuff;
86916870 6026 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6027 s->username[sizeof(s->username)-1] = '\0';
65a22376 6028 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6029 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6030 c_write_str(ssh, stuff);
57356d63 6031 sfree(stuff);
7cca0d81 6032 }
6033 }
51470298 6034 s->got_username = TRUE;
7cca0d81 6035
65a22376 6036 /*
1408a877 6037 * Send an authentication request using method "none": (a)
6038 * just in case it succeeds, and (b) so that we know what
6039 * authentication methods we can usefully try next.
65a22376 6040 */
51470298 6041 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6042
ff3187f6 6043 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6044 ssh2_pkt_addstring(s->pktout, s->username);
6045 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6046 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6047 ssh2_pkt_send(ssh, s->pktout);
51470298 6048 s->type = AUTH_TYPE_NONE;
6049 s->gotit = FALSE;
6050 s->we_are_in = FALSE;
6051
6052 s->tried_pubkey_config = FALSE;
6053 s->tried_agent = FALSE;
51470298 6054 s->kbd_inter_running = FALSE;
6ac3a551 6055 s->kbd_inter_refused = FALSE;
86916870 6056 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6057 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6058 int keytype;
6c6d9ed9 6059 logeventf(ssh, "Reading private key file \"%.150s\"",
6060 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6061 keytype = key_type(&ssh->cfg.keyfile);
51470298 6062 if (keytype == SSH_KEYTYPE_SSH2) {
6063 s->publickey_blob =
9a30e26b 6064 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6065 &s->publickey_bloblen, NULL);
51470298 6066 } else {
57356d63 6067 char *msgbuf;
c2ad7d0d 6068 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6069 key_type_to_str(keytype));
57356d63 6070 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6071 " (%s)\r\n",
6072 filename_to_str(&ssh->cfg.keyfile),
57356d63 6073 key_type_to_str(keytype));
51470298 6074 c_write_str(ssh, msgbuf);
57356d63 6075 sfree(msgbuf);
51470298 6076 s->publickey_blob = NULL;
231ee168 6077 }
396778f1 6078 } else
51470298 6079 s->publickey_blob = NULL;
65a22376 6080
1408a877 6081 while (1) {
6082 /*
6083 * Wait for the result of the last authentication request.
6084 */
51470298 6085 if (!s->gotit)
ff3187f6 6086 crWaitUntilV(pktin);
6087 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6088 char *banner;
6089 int size;
6090 /*
6091 * Don't show the banner if we're operating in
6092 * non-verbose non-interactive mode. (It's probably
6093 * a script, which means nobody will read the
6094 * banner _anyway_, and moreover the printing of
6095 * the banner will screw up processing on the
6096 * output of (say) plink.)
6097 */
6098 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6099 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6100 if (banner)
51470298 6101 c_write_untrusted(ssh, banner, size);
32874aea 6102 }
ff3187f6 6103 crWaitUntilV(pktin);
1408a877 6104 }
ff3187f6 6105 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6106 logevent("Access granted");
51470298 6107 s->we_are_in = TRUE;
1408a877 6108 break;
6109 }
65a22376 6110
51470298 6111 if (s->kbd_inter_running &&
ff3187f6 6112 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6113 /*
45068b27 6114 * This is either a further set-of-prompts packet
6115 * in keyboard-interactive authentication, or it's
6116 * the same one and we came back here with `gotit'
6117 * set. In the former case, we must reset the
6118 * curr_prompt variable.
b3186d64 6119 */
51470298 6120 if (!s->gotit)
6121 s->curr_prompt = 0;
4c6e53e3 6122 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6123 /* FIXME: perhaps we should support this? */
6124 bombout(("PASSWD_CHANGEREQ not yet supported"));
6125 crStopV;
ff3187f6 6126 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6127 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6128 pktin->type));
7ffdbc1a 6129 crStopV;
65a22376 6130 }
6131
51470298 6132 s->gotit = FALSE;
65a22376 6133
1408a877 6134 /*
6135 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6136 * we can look at the string in it and know what we can
6137 * helpfully try next.
6138 */
ff3187f6 6139 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6140 char *methods;
6141 int methlen;
ff3187f6 6142 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6143 s->kbd_inter_running = FALSE;
ff3187f6 6144 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6145 /*
6146 * We have received an unequivocal Access
6147 * Denied. This can translate to a variety of
6148 * messages:
6149 *
6150 * - if we'd just tried "none" authentication,
6151 * it's not worth printing anything at all
6152 *
6153 * - if we'd just tried a public key _offer_,
6154 * the message should be "Server refused our
6155 * key" (or no message at all if the key
6156 * came from Pageant)
6157 *
6158 * - if we'd just tried anything else, the
6159 * message really should be "Access denied".
6160 *
6161 * Additionally, if we'd just tried password
6162 * authentication, we should break out of this
6163 * whole loop so as to go back to the username
91f57d1f 6164 * prompt (iff we're configured to allow
6165 * username change attempts).
1408a877 6166 */
51470298 6167 if (s->type == AUTH_TYPE_NONE) {
1408a877 6168 /* do nothing */
51470298 6169 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6170 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6171 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6172 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6173 logevent("Server refused public key");
51470298 6174 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6175 /* server declined keyboard-interactive; ignore */
1408a877 6176 } else {
51470298 6177 c_write_str(ssh, "Access denied\r\n");
1408a877 6178 logevent("Access denied");
91f57d1f 6179 if (s->type == AUTH_TYPE_PASSWORD &&
6180 ssh->cfg.change_username) {
6c9dce7c 6181 /* XXX perhaps we should allow
6182 * keyboard-interactive to do this too? */
51470298 6183 s->we_are_in = FALSE;
1408a877 6184 break;
6185 }
6186 }
6187 } else {
51470298 6188 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6189 logevent("Further authentication required");
6190 }
65a22376 6191
51470298 6192 s->can_pubkey =
32874aea 6193 in_commasep_string("publickey", methods, methlen);
51470298 6194 s->can_passwd =
32874aea 6195 in_commasep_string("password", methods, methlen);
86916870 6196 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6197 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6198 }
65a22376 6199
51470298 6200 s->method = 0;
6201 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6202 s->need_pw = FALSE;
65a22376 6203
0405e71f 6204 /*
6205 * Most password/passphrase prompts will be
6206 * non-echoing, so we set this to 0 by default.
6207 * Exception is that some keyboard-interactive prompts
6208 * can be echoing, in which case we'll set this to 1.
6209 */
51470298 6210 s->echo = 0;
0405e71f 6211
51470298 6212 if (!s->method && s->can_pubkey &&
6213 agent_exists() && !s->tried_agent) {
1983e559 6214 /*
6215 * Attempt public-key authentication using Pageant.
6216 */
1983e559 6217 void *r;
51470298 6218 s->authed = FALSE;
1983e559 6219
51470298 6220 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6221 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6222
51470298 6223 s->tried_agent = TRUE;
1983e559 6224
6225 logevent("Pageant is running. Requesting keys.");
6226
6227 /* Request the keys held by the agent. */
51470298 6228 PUT_32BIT(s->request, 1);
6229 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6230 if (!agent_query(s->request, 5, &r, &s->responselen,
6231 ssh_agent_callback, ssh)) {
6232 do {
6233 crReturnV;
ff3187f6 6234 if (pktin) {
839f10db 6235 bombout(("Unexpected data from server while"
6236 " waiting for agent response"));
6237 crStopV;
6238 }
ff3187f6 6239 } while (pktin || inlen > 0);
839f10db 6240 r = ssh->agent_response;
6241 s->responselen = ssh->agent_response_len;
6242 }
51470298 6243 s->response = (unsigned char *) r;
6244 if (s->response && s->responselen >= 5 &&
6245 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6246 s->p = s->response + 5;
6247 s->nkeys = GET_32BIT(s->p);
6248 s->p += 4;
32874aea 6249 {
6250 char buf[64];
51470298 6251 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6252 logevent(buf);
6253 }
51470298 6254 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6255 void *vret;
1983e559 6256
32874aea 6257 {
6258 char buf[64];
51470298 6259 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6260 logevent(buf);
6261 }
51470298 6262 s->pklen = GET_32BIT(s->p);
6263 s->p += 4;
6264 if (s->publickey_blob &&
6265 s->pklen == s->publickey_bloblen &&
6266 !memcmp(s->p, s->publickey_blob,
6267 s->publickey_bloblen)) {
396778f1 6268 logevent("This key matches configured key file");
51470298 6269 s->tried_pubkey_config = 1;
396778f1 6270 }
d8baa528 6271 s->pkblob = (char *)s->p;
51470298 6272 s->p += s->pklen;
6273 s->alglen = GET_32BIT(s->pkblob);
6274 s->alg = s->pkblob + 4;
6275 s->commentlen = GET_32BIT(s->p);
6276 s->p += 4;
d8baa528 6277 s->commentp = (char *)s->p;
51470298 6278 s->p += s->commentlen;
ff3187f6 6279 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6280 ssh2_pkt_addstring(s->pktout, s->username);
6281 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6282 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6283 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6284 ssh2_pkt_addstring_start(s->pktout);
6285 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6286 ssh2_pkt_addstring_start(s->pktout);
6287 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6288 ssh2_pkt_send(ssh, s->pktout);
6289
6290 crWaitUntilV(pktin);
6291 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6292 logevent("Key refused");
6293 continue;
6294 }
6295
32874aea 6296 if (flags & FLAG_VERBOSE) {
51470298 6297 c_write_str(ssh, "Authenticating with "
6298 "public key \"");
6299 c_write(ssh, s->commentp, s->commentlen);
6300 c_write_str(ssh, "\" from agent\r\n");
32874aea 6301 }
1983e559 6302
6303 /*
6304 * Server is willing to accept the key.
6305 * Construct a SIGN_REQUEST.
6306 */
ff3187f6 6307 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6308 ssh2_pkt_addstring(s->pktout, s->username);
6309 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6310 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6311 ssh2_pkt_addbool(s->pktout, TRUE);
6312 ssh2_pkt_addstring_start(s->pktout);
6313 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6314 ssh2_pkt_addstring_start(s->pktout);
6315 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6316
6317 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6318 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6319 s->siglen -= 4;
51470298 6320 s->len = 1; /* message type */
6321 s->len += 4 + s->pklen; /* key blob */
6322 s->len += 4 + s->siglen; /* data to sign */
6323 s->len += 4; /* flags */
3d88e64d 6324 s->agentreq = snewn(4 + s->len, char);
51470298 6325 PUT_32BIT(s->agentreq, s->len);
6326 s->q = s->agentreq + 4;
6327 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6328 PUT_32BIT(s->q, s->pklen);
6329 s->q += 4;
6330 memcpy(s->q, s->pkblob, s->pklen);
6331 s->q += s->pklen;
6332 PUT_32BIT(s->q, s->siglen);
6333 s->q += 4;
1983e559 6334 /* Now the data to be signed... */
dda87a28 6335 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6336 PUT_32BIT(s->q, 20);
6337 s->q += 4;
6338 }
51470298 6339 memcpy(s->q, ssh->v2_session_id, 20);
6340 s->q += 20;
ff3187f6 6341 memcpy(s->q, s->pktout->data + 5,
6342 s->pktout->length - 5);
6343 s->q += s->pktout->length - 5;
1983e559 6344 /* And finally the (zero) flags word. */
51470298 6345 PUT_32BIT(s->q, 0);
839f10db 6346 if (!agent_query(s->agentreq, s->len + 4,
6347 &vret, &s->retlen,
6348 ssh_agent_callback, ssh)) {
6349 do {
6350 crReturnV;
ff3187f6 6351 if (pktin) {
839f10db 6352 bombout(("Unexpected data from server"
6353 " while waiting for agent"
6354 " response"));
6355 crStopV;
6356 }
ff3187f6 6357 } while (pktin || inlen > 0);
839f10db 6358 vret = ssh->agent_response;
6359 s->retlen = ssh->agent_response_len;
6360 }
51470298 6361 s->ret = vret;
6362 sfree(s->agentreq);
6363 if (s->ret) {
6364 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6365 logevent("Sending Pageant's response");
ff3187f6 6366 ssh2_add_sigblob(ssh, s->pktout,
6367 s->pkblob, s->pklen,
51470298 6368 s->ret + 9,
6369 GET_32BIT(s->ret + 5));
ff3187f6 6370 ssh2_pkt_send(ssh, s->pktout);
51470298 6371 s->authed = TRUE;
1983e559 6372 break;
6373 } else {
32874aea 6374 logevent
6375 ("Pageant failed to answer challenge");
51470298 6376 sfree(s->ret);
1983e559 6377 }
6378 }
6379 }
51470298 6380 if (s->authed)
1983e559 6381 continue;
6382 }
29b1d0b3 6383 sfree(s->response);
1983e559 6384 }
6385
51470298 6386 if (!s->method && s->can_pubkey && s->publickey_blob
6387 && !s->tried_pubkey_config) {
1408a877 6388 unsigned char *pub_blob;
6389 char *algorithm, *comment;
6390 int pub_blob_len;
65a22376 6391
51470298 6392 s->tried_pubkey_config = TRUE;
65a22376 6393
51470298 6394 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6395 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6396
65a22376 6397 /*
1408a877 6398 * Try the public key supplied in the configuration.
6399 *
6400 * First, offer the public blob to see if the server is
6401 * willing to accept it.
65a22376 6402 */
d8baa528 6403 pub_blob =
9a30e26b 6404 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6405 &algorithm,
222d54dc 6406 &pub_blob_len,
6407 NULL);
1408a877 6408 if (pub_blob) {
ff3187f6 6409 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6410 ssh2_pkt_addstring(s->pktout, s->username);
6411 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6412 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6413 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6414 ssh2_pkt_addstring(s->pktout, algorithm);
6415 ssh2_pkt_addstring_start(s->pktout);
6416 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6417 pub_blob_len);
ff3187f6 6418 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6419 logevent("Offered public key");
1408a877 6420
ff3187f6 6421 crWaitUntilV(pktin);
6422 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6423 s->gotit = TRUE;
6424 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6425 continue; /* key refused; give up on it */
1408a877 6426 }
65a22376 6427
1408a877 6428 logevent("Offer of public key accepted");
65a22376 6429 /*
1408a877 6430 * Actually attempt a serious authentication using
6431 * the key.
65a22376 6432 */
9a30e26b 6433 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6434 sprintf(s->pwprompt,
32874aea 6435 "Passphrase for key \"%.100s\": ",
6436 comment);
51470298 6437 s->need_pw = TRUE;
1408a877 6438 } else {
51470298 6439 s->need_pw = FALSE;
1408a877 6440 }
4e520718 6441 if (flags & FLAG_VERBOSE) {
6442 c_write_str(ssh, "Authenticating with public key \"");
6443 c_write_str(ssh, comment);
6444 c_write_str(ssh, "\"\r\n");
6445 }
51470298 6446 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6447 }
1408a877 6448 }
6449
6ac3a551 6450 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused) {
51470298 6451 s->method = AUTH_KEYBOARD_INTERACTIVE;
6452 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6453
51470298 6454 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6455 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6456
ff3187f6 6457 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6458 ssh2_pkt_addstring(s->pktout, s->username);
6459 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6460 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6461 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6462 ssh2_pkt_addstring(s->pktout, "");
6463 ssh2_pkt_send(ssh, s->pktout);
6464
6465 crWaitUntilV(pktin);
6466 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6467 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6468 s->gotit = TRUE;
af659722 6469 logevent("Keyboard-interactive authentication refused");
51470298 6470 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6471 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6472 continue;
6473 }
6474
51470298 6475 s->kbd_inter_running = TRUE;
6476 s->curr_prompt = 0;
af659722 6477 }
6478
51470298 6479 if (s->kbd_inter_running) {
6480 s->method = AUTH_KEYBOARD_INTERACTIVE;
6481 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6482
51470298 6483 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6484 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6485
51470298 6486 if (s->curr_prompt == 0) {
45068b27 6487 /*
6488 * We've got a fresh USERAUTH_INFO_REQUEST.
6489 * Display header data, and start going through
6490 * the prompts.
6491 */
6492 char *name, *inst, *lang;
6493 int name_len, inst_len, lang_len;
6494
ff3187f6 6495 ssh_pkt_getstring(pktin, &name, &name_len);
6496 ssh_pkt_getstring(pktin, &inst, &inst_len);
6497 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6498 if (name_len > 0) {
51470298 6499 c_write_untrusted(ssh, name, name_len);
6500 c_write_str(ssh, "\r\n");
45068b27 6501 }
6502 if (inst_len > 0) {
51470298 6503 c_write_untrusted(ssh, inst, inst_len);
6504 c_write_str(ssh, "\r\n");
45068b27 6505 }
ff3187f6 6506 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6507 }
af659722 6508
45068b27 6509 /*
6510 * If there are prompts remaining in the packet,
6511 * display one and get a response.
6512 */
51470298 6513 if (s->curr_prompt < s->num_prompts) {
45068b27 6514 char *prompt;
6515 int prompt_len;
af659722 6516
ff3187f6 6517 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6518 if (prompt_len > 0) {
85fdbe25 6519 static const char trunc[] = "<prompt truncated>: ";
6520 static const int prlen = sizeof(s->pwprompt) -
6521 lenof(trunc);
6522 if (prompt_len > prlen) {
6523 memcpy(s->pwprompt, prompt, prlen);
6524 strcpy(s->pwprompt + prlen, trunc);
6525 } else {
6526 memcpy(s->pwprompt, prompt, prompt_len);
6527 s->pwprompt[prompt_len] = '\0';
6528 }
45068b27 6529 } else {
51470298 6530 strcpy(s->pwprompt,
45068b27 6531 "<server failed to send prompt>: ");
6532 }
ff3187f6 6533 s->echo = ssh2_pkt_getbool(pktin);
51470298 6534 s->need_pw = TRUE;
45068b27 6535 } else
51470298 6536 s->need_pw = FALSE;
af659722 6537 }
6538
51470298 6539 if (!s->method && s->can_passwd) {
6540 s->method = AUTH_PASSWORD;
6541 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6542 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6543 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6544 ssh->savedhost);
6545 s->need_pw = TRUE;
1408a877 6546 }
6547
51470298 6548 if (s->need_pw) {
fa17a66e 6549 if (ssh_get_line) {
51470298 6550 if (!ssh_get_line(s->pwprompt, s->password,
6551 sizeof(s->password), TRUE)) {
1408a877 6552 /*
fa17a66e 6553 * get_line failed to get a password (for
6554 * example because one was supplied on the
6555 * command line which has already failed to
6556 * work). Terminate.
1408a877 6557 */
ff3187f6 6558 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6559 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6560 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6561 " to try");
ff3187f6 6562 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6563 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6564 logevent("Unable to authenticate");
a8327734 6565 connection_fatal(ssh->frontend,
6566 "Unable to authenticate");
3bb2f322 6567 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6568 crStopV;
1408a877 6569 }
6570 } else {
51470298 6571 int ret; /* need not be saved across crReturn */
6572 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6573 ssh->send_ok = 1;
1408a877 6574
51470298 6575 setup_userpass_input(ssh, s->password,
6576 sizeof(s->password), s->echo);
0405e71f 6577 do {
ff3187f6 6578 crWaitUntilV(!pktin);
51470298 6579 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6580 } while (ret == 0);
6581 if (ret < 0)
6582 cleanup_exit(0);
51470298 6583 c_write_str(ssh, "\r\n");
65a22376 6584 }
65a22376 6585 }
65a22376 6586
51470298 6587 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6588 /*
6589 * We have our passphrase. Now try the actual authentication.
6590 */
6591 struct ssh2_userkey *key;
222d54dc 6592 const char *error = NULL;
65a22376 6593
222d54dc 6594 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6595 &error);
1408a877 6596 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6597 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6598 c_write_str(ssh, "Wrong passphrase\r\n");
6599 s->tried_pubkey_config = FALSE;
1408a877 6600 } else {
222d54dc 6601 c_write_str(ssh, "Unable to load private key (");
6602 c_write_str(ssh, error);
6603 c_write_str(ssh, ")\r\n");
51470298 6604 s->tried_pubkey_config = TRUE;
1408a877 6605 }
6606 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6607 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6608 ssh2_pkt_addstring(s->pktout, s->username);
6609 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6610 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6611 ssh2_pkt_send(ssh, s->pktout);
51470298 6612 s->type = AUTH_TYPE_NONE;
1408a877 6613 } else {
1dd353b5 6614 unsigned char *pkblob, *sigblob, *sigdata;
6615 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6616 int p;
65a22376 6617
1408a877 6618 /*
6619 * We have loaded the private key and the server
6620 * has announced that it's willing to accept it.
6621 * Hallelujah. Generate a signature and send it.
6622 */
ff3187f6 6623 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6624 ssh2_pkt_addstring(s->pktout, s->username);
6625 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6626 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6627 ssh2_pkt_addbool(s->pktout, TRUE);
6628 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6629 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6630 ssh2_pkt_addstring_start(s->pktout);
6631 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6632
6633 /*
6634 * The data to be signed is:
6635 *
6636 * string session-id
6637 *
6638 * followed by everything so far placed in the
6639 * outgoing packet.
6640 */
ff3187f6 6641 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6642 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6643 sigdata_len -= 4;
92d60585 6644 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6645 p = 0;
6646 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6647 PUT_32BIT(sigdata+p, 20);
6648 p += 4;
6649 }
6650 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6651 memcpy(sigdata+p, s->pktout->data + 5,
6652 s->pktout->length - 5);
6653 p += s->pktout->length - 5;
dda87a28 6654 assert(p == sigdata_len);
d8baa528 6655 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6656 sigdata_len, &sigblob_len);
ff3187f6 6657 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6658 sigblob, sigblob_len);
6659 sfree(pkblob);
6660 sfree(sigblob);
1408a877 6661 sfree(sigdata);
6662
ff3187f6 6663 ssh2_pkt_send(ssh, s->pktout);
51470298 6664 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6665 key->alg->freekey(key->data);
1408a877 6666 }
51470298 6667 } else if (s->method == AUTH_PASSWORD) {
65a22376 6668 /*
1408a877 6669 * We send the password packet lumped tightly together with
6670 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6671 * string long enough to make the total length of the two
6672 * packets constant. This should ensure that a passive
6673 * listener doing traffic analyis can't work out the length
6674 * of the password.
6675 *
6676 * For this to work, we need an assumption about the
6677 * maximum length of the password packet. I think 256 is
6678 * pretty conservative. Anyone using a password longer than
6679 * that probably doesn't have much to worry about from
6680 * people who find out how long their password is!
65a22376 6681 */
ff3187f6 6682 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6683 ssh2_pkt_addstring(s->pktout, s->username);
6684 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6685 ssh2_pkt_addstring(s->pktout, "password");
6686 ssh2_pkt_addbool(s->pktout, FALSE);
6687 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6688 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6689 memset(s->password, 0, sizeof(s->password));
ff3187f6 6690 end_log_omission(ssh, s->pktout);
6691 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6692 /*
1408a877 6693 * We'll include a string that's an exact multiple of the
6694 * cipher block size. If the cipher is NULL for some
6695 * reason, we don't do this trick at all because we gain
6696 * nothing by it.
65a22376 6697 */
51470298 6698 if (ssh->cscipher) {
32874aea 6699 int stringlen, i;
6700
51470298 6701 stringlen = (256 - ssh->deferred_len);
6702 stringlen += ssh->cscipher->blksize - 1;
6703 stringlen -= (stringlen % ssh->cscipher->blksize);
6704 if (ssh->cscomp) {
32874aea 6705 /*
6706 * Temporarily disable actual compression,
6707 * so we can guarantee to get this string
6708 * exactly the length we want it. The
6709 * compression-disabling routine should
6710 * return an integer indicating how many
6711 * bytes we should adjust our string length
6712 * by.
6713 */
5366aed8 6714 stringlen -=
6715 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6716 }
ff3187f6 6717 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6718 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6719 for (i = 0; i < stringlen; i++) {
32874aea 6720 char c = (char) random_byte();
ff3187f6 6721 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6722 }
ff3187f6 6723 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6724 }
51470298 6725 ssh_pkt_defersend(ssh);
0d43337a 6726 logevent("Sent password");
51470298 6727 s->type = AUTH_TYPE_PASSWORD;
6728 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6729 if (s->curr_prompt == 0) {
ff3187f6 6730 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6731 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6732 }
51470298 6733 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6734 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6735 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6736 memset(s->password, 0, sizeof(s->password));
ff3187f6 6737 end_log_omission(ssh, s->pktout);
51470298 6738 s->curr_prompt++;
45068b27 6739 }
51470298 6740 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6741 ssh2_pkt_send(ssh, s->pktout);
45068b27 6742 } else {
6743 /*
6744 * If there are prompts remaining, we set
6745 * `gotit' so that we won't attempt to get
6746 * another packet. Then we go back round the
6747 * loop and will end up retrieving another
6748 * prompt out of the existing packet. Funky or
6749 * what?
6750 */
51470298 6751 s->gotit = TRUE;
45068b27 6752 }
51470298 6753 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6754 } else {
51470298 6755 c_write_str(ssh, "No supported authentication methods"
6756 " left to try!\r\n");
6757 logevent("No supported authentications offered."
6758 " Disconnecting");
ff3187f6 6759 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6760 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6761 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6762 " methods available");
ff3187f6 6763 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6764 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6765 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6766 crStopV;
65a22376 6767 }
65a22376 6768 }
51470298 6769 } while (!s->we_are_in);
7cca0d81 6770
6771 /*
6772 * Now we're authenticated for the connection protocol. The
6773 * connection protocol will automatically have started at this
6774 * point; there's no need to send SERVICE_REQUEST.
6775 */
6776
0ed48730 6777 ssh->channels = newtree234(ssh_channelcmp);
6778
7cca0d81 6779 /*
b09eaa88 6780 * Set up handlers for some connection protocol messages, so we
6781 * don't have to handle them repeatedly in this coroutine.
6782 */
6783 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6784 ssh2_msg_channel_window_adjust;
51df0ab5 6785 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6786 ssh2_msg_global_request;
b09eaa88 6787
6788 /*
0ed48730 6789 * Create the main session channel.
7cca0d81 6790 */
0ed48730 6791 if (!ssh->cfg.ssh_no_shell) {
6792 ssh->mainchan = snew(struct ssh_channel);
6793 ssh->mainchan->ssh = ssh;
6794 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6795 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6796 ssh2_pkt_addstring(s->pktout, "session");
6797 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6798 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6799 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6800 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6801 ssh2_pkt_send(ssh, s->pktout);
6802 crWaitUntilV(pktin);
6803 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6804 bombout(("Server refused to open a session"));
6805 crStopV;
6806 /* FIXME: error data comes back in FAILURE packet */
6807 }
ff3187f6 6808 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6809 bombout(("Server's channel confirmation cited wrong channel"));
6810 crStopV;
6811 }
ff3187f6 6812 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6813 ssh->mainchan->type = CHAN_MAINSESSION;
6814 ssh->mainchan->closes = 0;
ff3187f6 6815 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6816 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6817 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6818 add234(ssh->channels, ssh->mainchan);
62638676 6819 update_specials_menu(ssh->frontend);
0ed48730 6820 logevent("Opened channel for session");
6821 } else
6822 ssh->mainchan = NULL;
7cca0d81 6823
6824 /*
51df0ab5 6825 * Now we have a channel, make dispatch table entries for
6826 * general channel-based messages.
6827 */
6828 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6829 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6830 ssh2_msg_channel_data;
6831 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6832 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6833 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6834 ssh2_msg_channel_open_confirmation;
6835 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6836 ssh2_msg_channel_open_failure;
6837 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6838 ssh2_msg_channel_request;
6839 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6840 ssh2_msg_channel_open;
6841
6842 /*
783415f8 6843 * Potentially enable X11 forwarding.
6844 */
0ed48730 6845 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6846 char proto[20], data[64];
6847 logevent("Requesting X11 forwarding");
302121de 6848 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6849 data, sizeof(data), ssh->cfg.x11_auth);
6850 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6851 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6852 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6853 ssh2_pkt_addstring(s->pktout, "x11-req");
6854 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6855 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6856 ssh2_pkt_addstring(s->pktout, proto);
6857 ssh2_pkt_addstring(s->pktout, data);
6858 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6859 ssh2_pkt_send(ssh, s->pktout);
32874aea 6860
b09eaa88 6861 crWaitUntilV(pktin);
32874aea 6862
ff3187f6 6863 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6864 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6865 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6866 " packet type %d", pktin->type));
7ffdbc1a 6867 crStopV;
32874aea 6868 }
6869 logevent("X11 forwarding refused");
6870 } else {
6871 logevent("X11 forwarding enabled");
51470298 6872 ssh->X11_fwd_enabled = TRUE;
32874aea 6873 }
783415f8 6874 }
6875
6876 /*
bc240b21 6877 * Enable port forwardings.
6878 */
06fadff5 6879 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6880
6881 /*
36c2a3e9 6882 * Potentially enable agent forwarding.
6883 */
0ed48730 6884 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6885 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6886 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6887 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6888 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6889 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6890 ssh2_pkt_send(ssh, s->pktout);
32874aea 6891
b09eaa88 6892 crWaitUntilV(pktin);
32874aea 6893
ff3187f6 6894 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6895 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6896 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6897 " packet type %d", pktin->type));
7ffdbc1a 6898 crStopV;
32874aea 6899 }
6900 logevent("Agent forwarding refused");
6901 } else {
6902 logevent("Agent forwarding enabled");
51470298 6903 ssh->agentfwd_enabled = TRUE;
32874aea 6904 }
36c2a3e9 6905 }
6906
6907 /*
7cca0d81 6908 * Now allocate a pty for the session.
6909 */
0ed48730 6910 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6911 /* Unpick the terminal-speed string. */
6912 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6913 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6914 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6915 /* Build the pty request. */
ff3187f6 6916 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6917 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6918 ssh2_pkt_addstring(s->pktout, "pty-req");
6919 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6920 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6921 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6922 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6923 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6924 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6925 ssh2_pkt_addstring_start(s->pktout);
6926 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6927 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6928 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6929 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6930 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6931 ssh2_pkt_send(ssh, s->pktout);
51470298 6932 ssh->state = SSH_STATE_INTERMED;
32874aea 6933
b09eaa88 6934 crWaitUntilV(pktin);
32874aea 6935
ff3187f6 6936 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6937 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6938 bombout(("Unexpected response to pty request:"
ff3187f6 6939 " packet type %d", pktin->type));
7ffdbc1a 6940 crStopV;
32874aea 6941 }
51470298 6942 c_write_str(ssh, "Server refused to allocate pty\r\n");
6943 ssh->editing = ssh->echoing = 1;
32874aea 6944 } else {
a5dd8467 6945 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6946 ssh->ospeed, ssh->ispeed);
32874aea 6947 }
0965bee0 6948 } else {
51470298 6949 ssh->editing = ssh->echoing = 1;
7cca0d81 6950 }
6951
6952 /*
73feed4f 6953 * Send environment variables.
6954 *
6955 * Simplest thing here is to send all the requests at once, and
6956 * then wait for a whole bunch of successes or failures.
6957 */
6958 if (ssh->mainchan && *ssh->cfg.environmt) {
6959 char *e = ssh->cfg.environmt;
6960 char *var, *varend, *val;
6961
6962 s->num_env = 0;
6963
6964 while (*e) {
6965 var = e;
6966 while (*e && *e != '\t') e++;
6967 varend = e;
6968 if (*e == '\t') e++;
6969 val = e;
6970 while (*e) e++;
6971 e++;
6972
ff3187f6 6973 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6974 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6975 ssh2_pkt_addstring(s->pktout, "env");
6976 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6977 ssh2_pkt_addstring_start(s->pktout);
6978 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6979 ssh2_pkt_addstring(s->pktout, val);
6980 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6981
6982 s->num_env++;
6983 }
6984
6985 logeventf(ssh, "Sent %d environment variables", s->num_env);
6986
6987 s->env_ok = 0;
6988 s->env_left = s->num_env;
6989
6990 while (s->env_left > 0) {
b09eaa88 6991 crWaitUntilV(pktin);
73feed4f 6992
ff3187f6 6993 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6994 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6995 bombout(("Unexpected response to environment request:"
ff3187f6 6996 " packet type %d", pktin->type));
73feed4f 6997 crStopV;
6998 }
6999 } else {
7000 s->env_ok++;
7001 }
7002
7003 s->env_left--;
7004 }
7005
7006 if (s->env_ok == s->num_env) {
7007 logevent("All environment variables successfully set");
7008 } else if (s->env_ok == 0) {
7009 logevent("All environment variables refused");
7010 c_write_str(ssh, "Server refused to set environment variables\r\n");
7011 } else {
7012 logeventf(ssh, "%d environment variables refused",
7013 s->num_env - s->env_ok);
7014 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7015 }
7016 }
7017
7018 /*
fd5e5847 7019 * Start a shell or a remote command. We may have to attempt
7020 * this twice if the config data has provided a second choice
7021 * of command.
7cca0d81 7022 */
0ed48730 7023 if (ssh->mainchan) while (1) {
fd5e5847 7024 int subsys;
7025 char *cmd;
7026
51470298 7027 if (ssh->fallback_cmd) {
86916870 7028 subsys = ssh->cfg.ssh_subsys2;
7029 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7030 } else {
86916870 7031 subsys = ssh->cfg.ssh_subsys;
7032 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7033 }
7034
ff3187f6 7035 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7036 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7037 if (subsys) {
ff3187f6 7038 ssh2_pkt_addstring(s->pktout, "subsystem");
7039 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7040 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7041 } else if (*cmd) {
ff3187f6 7042 ssh2_pkt_addstring(s->pktout, "exec");
7043 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7044 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7045 } else {
ff3187f6 7046 ssh2_pkt_addstring(s->pktout, "shell");
7047 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7048 }
ff3187f6 7049 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7050
7051 crWaitUntilV(pktin);
7052
ff3187f6 7053 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7054 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7055 bombout(("Unexpected response to shell/command request:"
ff3187f6 7056 " packet type %d", pktin->type));
7ffdbc1a 7057 crStopV;
fd5e5847 7058 }
7059 /*
7060 * We failed to start the command. If this is the
7061 * fallback command, we really are finished; if it's
7062 * not, and if the fallback command exists, try falling
7063 * back to it before complaining.
7064 */
86916870 7065 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7066 logevent("Primary command failed; attempting fallback");
51470298 7067 ssh->fallback_cmd = TRUE;
fd5e5847 7068 continue;
7069 }
6b5cf8b4 7070 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7071 crStopV;
fd5e5847 7072 } else {
7073 logevent("Started a shell/command");
32874aea 7074 }
fd5e5847 7075 break;
7cca0d81 7076 }
7077
51470298 7078 ssh->state = SSH_STATE_SESSION;
7079 if (ssh->size_needed)
7080 ssh_size(ssh, ssh->term_width, ssh->term_height);
7081 if (ssh->eof_needed)
7082 ssh_special(ssh, TS_EOF);
6e48c3fe 7083
7cca0d81 7084 /*
7085 * Transfer data!
7086 */
b9d7bcad 7087 if (ssh->ldisc)
7088 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7089 if (ssh->mainchan)
7090 ssh->send_ok = 1;
7cca0d81 7091 while (1) {
e5574168 7092 crReturnV;
51470298 7093 s->try_send = FALSE;
ff3187f6 7094 if (pktin) {
2b7540a7 7095
51df0ab5 7096 /*
7097 * _All_ the connection-layer packets we expect to
7098 * receive are now handled by the dispatch table.
7099 * Anything that reaches here must be bogus.
7100 */
32874aea 7101
51df0ab5 7102 bombout(("Strange packet received: type %d", pktin->type));
7103 crStopV;
0ed48730 7104 } else if (ssh->mainchan) {
32874aea 7105 /*
7106 * We have spare data. Add it to the channel buffer.
7107 */
d8baa528 7108 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7109 s->try_send = TRUE;
32874aea 7110 }
51470298 7111 if (s->try_send) {
32874aea 7112 int i;
7113 struct ssh_channel *c;
7114 /*
7115 * Try to send data on all channels if we can.
7116 */
51470298 7117 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7118 int bufsize;
7119 if (c->closes)
7120 continue; /* don't send on closing channels */
7121 bufsize = ssh2_try_send(c);
5471d09a 7122 if (bufsize == 0) {
7123 switch (c->type) {
7124 case CHAN_MAINSESSION:
7125 /* stdin need not receive an unthrottle
7126 * notification since it will be polled */
7127 break;
7128 case CHAN_X11:
7129 x11_unthrottle(c->u.x11.s);
7130 break;
7131 case CHAN_AGENT:
7132 /* agent sockets are request/response and need no
7133 * buffer management */
7134 break;
7135 case CHAN_SOCKDATA:
7136 pfd_unthrottle(c->u.pfd.s);
7137 break;
7138 }
7139 }
7140 }
7cca0d81 7141 }
e5574168 7142 }
7143
7144 crFinishV;
7145}
7146
7147/*
b09eaa88 7148 * Handlers for SSH2 messages that might arrive at any moment.
7149 */
7150void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7151{
7152 /* log reason code in disconnect message */
7153 char *buf, *msg;
7154 int nowlen, reason, msglen;
7155
7156 reason = ssh_pkt_getuint32(pktin);
7157 ssh_pkt_getstring(pktin, &msg, &msglen);
7158
7159 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7160 buf = dupprintf("Received disconnect message (%s)",
7161 ssh2_disconnect_reasons[reason]);
7162 } else {
7163 buf = dupprintf("Received disconnect message (unknown"
7164 " type %d)", reason);
7165 }
7166 logevent(buf);
7167 sfree(buf);
7168 buf = dupprintf("Disconnection message text: %n%.*s",
7169 &nowlen, msglen, msg);
7170 logevent(buf);
7171 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7172 reason,
7173 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7174 ssh2_disconnect_reasons[reason] : "unknown",
7175 buf+nowlen));
7176 sfree(buf);
7177}
7178
7179void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7180{
7181 /* log the debug message */
7182 char *buf, *msg;
7183 int msglen;
7184 int always_display;
7185
7186 /* XXX maybe we should actually take notice of this */
7187 always_display = ssh2_pkt_getbool(pktin);
7188 ssh_pkt_getstring(pktin, &msg, &msglen);
7189
7190 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7191 logevent(buf);
7192 sfree(buf);
7193}
7194
7195void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7196{
7197 struct Packet *pktout;
7198 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7199 ssh2_pkt_adduint32(pktout, pktin->sequence);
7200 /*
7201 * UNIMPLEMENTED messages MUST appear in the same order as the
7202 * messages they respond to. Hence, never queue them.
7203 */
7204 ssh2_pkt_send_noqueue(ssh, pktout);
7205}
7206
7207/*
7cca0d81 7208 * Handle the top-level SSH2 protocol.
7209 */
b09eaa88 7210static void ssh2_protocol_setup(Ssh ssh)
7211{
7212 int i;
7213
7214 /*
7215 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7216 */
7217 for (i = 0; i < 256; i++)
7218 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7219
7220 /*
7221 * Any message we actually understand, we set to NULL so that
7222 * the coroutines will get it.
7223 */
7224 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7225 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7226 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7227 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7228 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7229 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7230 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7231 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7232 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7233 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7234 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7235 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7236 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7237 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7238 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7239 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7240 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7241 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7242 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7243 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7244 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7245 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7246 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7247 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7248 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7249 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7250 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7251 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7252 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7253 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7254 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7255 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7256 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7257
7258 /*
7259 * These special message types we install handlers for.
7260 */
7261 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7262 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7263 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7264}
7265
9442dd57 7266static void ssh2_timer(void *ctx, long now)
7267{
7268 Ssh ssh = (Ssh)ctx;
7269
e6c1536e 7270 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7271 now - ssh->next_rekey >= 0) {
7272 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7273 -1, NULL);
7274 }
7275}
7276
ff3187f6 7277static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7278 struct Packet *pktin)
7cca0d81 7279{
b09eaa88 7280 if (ssh->state == SSH_STATE_CLOSED)
7281 return;
7282
9442dd57 7283 if (pktin) {
7284 ssh->incoming_data_size += pktin->encrypted_len;
7285 if (!ssh->kex_in_progress &&
d57f70af 7286 ssh->max_data_size != 0 &&
7287 ssh->incoming_data_size > ssh->max_data_size)
9442dd57 7288 do_ssh2_transport(ssh, "Initiating key re-exchange "
7289 "(too much data received)", -1, NULL);
7290 }
7291
b09eaa88 7292 if (pktin && ssh->packet_dispatch[pktin->type]) {
7293 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7294 return;
b09eaa88 7295 }
7296
7297 if (!ssh->protocol_initial_phase_done ||
7298 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7299 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7300 !ssh->protocol_initial_phase_done) {
7301 ssh->protocol_initial_phase_done = TRUE;
7302 /*
7303 * Allow authconn to initialise itself.
7304 */
7305 do_ssh2_authconn(ssh, NULL, 0, NULL);
7306 }
7307 } else {
7308 do_ssh2_authconn(ssh, in, inlen, pktin);
7309 }
7cca0d81 7310}
7311
7312/*
8df7a775 7313 * Called to set up the connection.
374330e2 7314 *
7315 * Returns an error message, or NULL on success.
374330e2 7316 */
cbe2d68f 7317static const char *ssh_init(void *frontend_handle, void **backend_handle,
7318 Config *cfg,
79bf227b 7319 char *host, int port, char **realhost, int nodelay,
7320 int keepalive)
32874aea 7321{
cbe2d68f 7322 const char *p;
51470298 7323 Ssh ssh;
7324
3d88e64d 7325 ssh = snew(struct ssh_tag);
86916870 7326 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7327 ssh->version = 0; /* when not ready yet */
51470298 7328 ssh->s = NULL;
7329 ssh->cipher = NULL;
371e569c 7330 ssh->v1_cipher_ctx = NULL;
0183b242 7331 ssh->crcda_ctx = NULL;
51470298 7332 ssh->cscipher = NULL;
371e569c 7333 ssh->cs_cipher_ctx = NULL;
51470298 7334 ssh->sccipher = NULL;
371e569c 7335 ssh->sc_cipher_ctx = NULL;
51470298 7336 ssh->csmac = NULL;
a8327734 7337 ssh->cs_mac_ctx = NULL;
51470298 7338 ssh->scmac = NULL;
e0e1a00d 7339 ssh->sc_mac_ctx = NULL;
51470298 7340 ssh->cscomp = NULL;
5366aed8 7341 ssh->cs_comp_ctx = NULL;
51470298 7342 ssh->sccomp = NULL;
5366aed8 7343 ssh->sc_comp_ctx = NULL;
51470298 7344 ssh->kex = NULL;
389aa499 7345 ssh->kex_ctx = NULL;
51470298 7346 ssh->hostkey = NULL;
7347 ssh->exitcode = -1;
7348 ssh->state = SSH_STATE_PREPACKET;
7349 ssh->size_needed = FALSE;
7350 ssh->eof_needed = FALSE;
b9d7bcad 7351 ssh->ldisc = NULL;
a8327734 7352 ssh->logctx = NULL;
51470298 7353 ssh->deferred_send_data = NULL;
7354 ssh->deferred_len = 0;
7355 ssh->deferred_size = 0;
7356 ssh->fallback_cmd = 0;
7357 ssh->pkt_ctx = 0;
302121de 7358 ssh->x11auth = NULL;
be738459 7359 ssh->v1_compressing = FALSE;
51470298 7360 ssh->v2_outgoing_sequence = 0;
7361 ssh->ssh1_rdpkt_crstate = 0;
7362 ssh->ssh2_rdpkt_crstate = 0;
7363 ssh->do_ssh_init_crstate = 0;
7364 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7365 ssh->do_ssh1_connection_crstate = 0;
51470298 7366 ssh->do_ssh1_login_crstate = 0;
7367 ssh->do_ssh2_transport_crstate = 0;
7368 ssh->do_ssh2_authconn_crstate = 0;
7369 ssh->do_ssh_init_state = NULL;
7370 ssh->do_ssh1_login_state = NULL;
7371 ssh->do_ssh2_transport_state = NULL;
7372 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7373 ssh->mainchan = NULL;
968d2d92 7374 ssh->throttled_all = 0;
7375 ssh->v1_stdout_throttling = 0;
590f6a5f 7376 ssh->queue = NULL;
7377 ssh->queuelen = ssh->queuesize = 0;
7378 ssh->queueing = FALSE;
06fadff5 7379 ssh->qhead = ssh->qtail = NULL;
e13bba36 7380 ssh->deferred_rekey_reason = NULL;
51470298 7381
7382 *backend_handle = ssh;
32874aea 7383
8f203108 7384#ifdef MSCRYPTOAPI
32874aea 7385 if (crypto_startup() == 0)
8f203108 7386 return "Microsoft high encryption pack not installed!";
7387#endif
374330e2 7388
51470298 7389 ssh->frontend = frontend_handle;
86916870 7390 ssh->term_width = ssh->cfg.width;
7391 ssh->term_height = ssh->cfg.height;
887035a5 7392
fabd1805 7393 ssh->channels = NULL;
7394 ssh->rportfwds = NULL;
f47a5ffb 7395 ssh->portfwds = NULL;
fabd1805 7396
51470298 7397 ssh->send_ok = 0;
7398 ssh->editing = 0;
7399 ssh->echoing = 0;
7400 ssh->v1_throttle_count = 0;
7401 ssh->overall_bufsize = 0;
7402 ssh->fallback_cmd = 0;
8df7a775 7403
3648d4c5 7404 ssh->protocol = NULL;
7405
b09eaa88 7406 ssh->protocol_initial_phase_done = FALSE;
7407
39934deb 7408 ssh->pinger = NULL;
7409
9442dd57 7410 ssh->incoming_data_size = ssh->outgoing_data_size =
7411 ssh->deferred_data_size = 0L;
d57f70af 7412 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7413 ssh->kex_in_progress = FALSE;
7414
79bf227b 7415 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7416 if (p != NULL)
7417 return p;
374330e2 7418
5d17ccfc 7419 random_ref();
7420
374330e2 7421 return NULL;
7422}
7423
fabd1805 7424static void ssh_free(void *handle)
7425{
7426 Ssh ssh = (Ssh) handle;
7427 struct ssh_channel *c;
7428 struct ssh_rportfwd *pf;
7429
7430 if (ssh->v1_cipher_ctx)
7431 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7432 if (ssh->cs_cipher_ctx)
7433 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7434 if (ssh->sc_cipher_ctx)
7435 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7436 if (ssh->cs_mac_ctx)
7437 ssh->csmac->free_context(ssh->cs_mac_ctx);
7438 if (ssh->sc_mac_ctx)
7439 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7440 if (ssh->cs_comp_ctx) {
7441 if (ssh->cscomp)
7442 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7443 else
7444 zlib_compress_cleanup(ssh->cs_comp_ctx);
7445 }
7446 if (ssh->sc_comp_ctx) {
7447 if (ssh->sccomp)
7448 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7449 else
7450 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7451 }
fabd1805 7452 if (ssh->kex_ctx)
7453 dh_cleanup(ssh->kex_ctx);
7454 sfree(ssh->savedhost);
7455
590f6a5f 7456 while (ssh->queuelen-- > 0)
7457 ssh_free_packet(ssh->queue[ssh->queuelen]);
7458 sfree(ssh->queue);
7459
06fadff5 7460 while (ssh->qhead) {
7461 struct queued_handler *qh = ssh->qhead;
7462 ssh->qhead = qh->next;
7463 sfree(ssh->qhead);
7464 }
7465 ssh->qhead = ssh->qtail = NULL;
7466
fabd1805 7467 if (ssh->channels) {
7468 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7469 switch (c->type) {
7470 case CHAN_X11:
7471 if (c->u.x11.s != NULL)
7472 x11_close(c->u.x11.s);
7473 break;
7474 case CHAN_SOCKDATA:
7475 if (c->u.pfd.s != NULL)
7476 pfd_close(c->u.pfd.s);
7477 break;
7478 }
7479 sfree(c);
7480 }
7481 freetree234(ssh->channels);
cdb52705 7482 ssh->channels = NULL;
fabd1805 7483 }
7484
7485 if (ssh->rportfwds) {
7486 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7487 sfree(pf);
7488 freetree234(ssh->rportfwds);
cdb52705 7489 ssh->rportfwds = NULL;
fabd1805 7490 }
7491 sfree(ssh->deferred_send_data);
7492 if (ssh->x11auth)
7493 x11_free_auth(ssh->x11auth);
7494 sfree(ssh->do_ssh_init_state);
7495 sfree(ssh->do_ssh1_login_state);
7496 sfree(ssh->do_ssh2_transport_state);
7497 sfree(ssh->do_ssh2_authconn_state);
679539d7 7498 if (ssh->crcda_ctx) {
7499 crcda_free_context(ssh->crcda_ctx);
7500 ssh->crcda_ctx = NULL;
7501 }
fabd1805 7502 if (ssh->s)
36f94d1f 7503 ssh_do_close(ssh);
9442dd57 7504 expire_timer_context(ssh);
39934deb 7505 if (ssh->pinger)
7506 pinger_free(ssh->pinger);
ee50e8b6 7507 sfree(ssh);
5d17ccfc 7508
7509 random_unref();
fabd1805 7510}
7511
374330e2 7512/*
86916870 7513 * Reconfigure the SSH backend.
86916870 7514 */
7515static void ssh_reconfig(void *handle, Config *cfg)
7516{
7517 Ssh ssh = (Ssh) handle;
e13bba36 7518 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7519 unsigned long old_max_data_size;
7520
39934deb 7521 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7522 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7523
7524 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7525 cfg->ssh_rekey_time != 0) {
7526 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7527 long now = GETTICKCOUNT();
7528
7529 if (new_next - now < 0) {
7530 rekeying = "Initiating key re-exchange (timeout shortened)";
7531 } else {
7532 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7533 }
7534 }
7535
7536 old_max_data_size = ssh->max_data_size;
7537 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7538 if (old_max_data_size != ssh->max_data_size &&
7539 ssh->max_data_size != 0) {
7540 if (ssh->outgoing_data_size > ssh->max_data_size ||
7541 ssh->incoming_data_size > ssh->max_data_size)
7542 rekeying = "Initiating key re-exchange (data limit lowered)";
7543 }
7544
e13bba36 7545 if (ssh->cfg.compression != cfg->compression) {
7546 rekeying = "Initiating key re-exchange (compression setting changed)";
7547 rekey_mandatory = TRUE;
7548 }
7549
7550 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7551 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7552 sizeof(ssh->cfg.ssh_cipherlist))) {
7553 rekeying = "Initiating key re-exchange (cipher settings changed)";
7554 rekey_mandatory = TRUE;
e6c1536e 7555 }
7556
86916870 7557 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7558
7559 if (rekeying) {
7560 if (!ssh->kex_in_progress) {
7561 do_ssh2_transport(ssh, rekeying, -1, NULL);
7562 } else if (rekey_mandatory) {
7563 ssh->deferred_rekey_reason = rekeying;
7564 }
7565 }
86916870 7566}
7567
7568/*
374330e2 7569 * Called to send data down the Telnet connection.
7570 */
51470298 7571static int ssh_send(void *handle, char *buf, int len)
32874aea 7572{
51470298 7573 Ssh ssh = (Ssh) handle;
7574
7575 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7576 return 0;
374330e2 7577
d8baa528 7578 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7579
51470298 7580 return ssh_sendbuffer(ssh);
5471d09a 7581}
7582
7583/*
7584 * Called to query the current amount of buffered stdin data.
7585 */
51470298 7586static int ssh_sendbuffer(void *handle)
5471d09a 7587{
51470298 7588 Ssh ssh = (Ssh) handle;
5471d09a 7589 int override_value;
7590
51470298 7591 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7592 return 0;
7593
7594 /*
7595 * If the SSH socket itself has backed up, add the total backup
7596 * size on that to any individual buffer on the stdin channel.
7597 */
7598 override_value = 0;
51470298 7599 if (ssh->throttled_all)
7600 override_value = ssh->overall_bufsize;
5471d09a 7601
51470298 7602 if (ssh->version == 1) {
5471d09a 7603 return override_value;
51470298 7604 } else if (ssh->version == 2) {
7605 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7606 return override_value;
7607 else
51470298 7608 return (override_value +
7609 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7610 }
7611
7612 return 0;
374330e2 7613}
7614
7615/*
6e48c3fe 7616 * Called to set the size of the window from SSH's POV.
374330e2 7617 */
51470298 7618static void ssh_size(void *handle, int width, int height)
32874aea 7619{
51470298 7620 Ssh ssh = (Ssh) handle;
ff3187f6 7621 struct Packet *pktout;
51470298 7622
7623 ssh->term_width = width;
7624 ssh->term_height = height;
f278d6f8 7625
51470298 7626 switch (ssh->state) {
374330e2 7627 case SSH_STATE_BEFORE_SIZE:
3687d221 7628 case SSH_STATE_PREPACKET:
21248260 7629 case SSH_STATE_CLOSED:
374330e2 7630 break; /* do nothing */
7631 case SSH_STATE_INTERMED:
51470298 7632 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7633 break;
7634 case SSH_STATE_SESSION:
86916870 7635 if (!ssh->cfg.nopty) {
51470298 7636 if (ssh->version == 1) {
7637 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7638 PKT_INT, ssh->term_height,
7639 PKT_INT, ssh->term_width,
32874aea 7640 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7641 } else if (ssh->mainchan) {
ff3187f6 7642 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7643 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7644 ssh2_pkt_addstring(pktout, "window-change");
7645 ssh2_pkt_addbool(pktout, 0);
7646 ssh2_pkt_adduint32(pktout, ssh->term_width);
7647 ssh2_pkt_adduint32(pktout, ssh->term_height);
7648 ssh2_pkt_adduint32(pktout, 0);
7649 ssh2_pkt_adduint32(pktout, 0);
7650 ssh2_pkt_send(ssh, pktout);
32874aea 7651 }
7652 }
7653 break;
374330e2 7654 }
7655}
7656
7657/*
125105d1 7658 * Return a list of the special codes that make sense in this
7659 * protocol.
7660 */
7661static const struct telnet_special *ssh_get_specials(void *handle)
7662{
786ba75e 7663 static const struct telnet_special ssh1_ignore_special[] = {
7664 {"IGNORE message", TS_NOP}
7665 };
7666 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7667 {"IGNORE message", TS_NOP},
9442dd57 7668 {"Repeat key exchange", TS_REKEY},
62638676 7669 };
7670 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7671 {NULL, TS_SEP},
7672 {"Break", TS_BRK},
786ba75e 7673 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7674 * They include all the ISO C signals, but are a subset of the POSIX
7675 * required signals. */
7676 {"SIGINT (Interrupt)", TS_SIGINT},
7677 {"SIGTERM (Terminate)", TS_SIGTERM},
7678 {"SIGKILL (Kill)", TS_SIGKILL},
7679 {"SIGQUIT (Quit)", TS_SIGQUIT},
7680 {"SIGHUP (Hangup)", TS_SIGHUP},
7681 {"More signals", TS_SUBMENU},
7682 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7683 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7684 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7685 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7686 {NULL, TS_EXITMENU}
62638676 7687 };
7688 static const struct telnet_special specials_end[] = {
6f2d0cde 7689 {NULL, TS_EXITMENU}
62638676 7690 };
786ba75e 7691 /* XXX review this length for any changes: */
7692 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7693 lenof(ssh2_session_specials) +
7694 lenof(specials_end)];
125105d1 7695 Ssh ssh = (Ssh) handle;
62638676 7696 int i = 0;
7697#define ADD_SPECIALS(name) \
7698 do { \
7699 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7700 memcpy(&ssh_specials[i], name, sizeof name); \
7701 i += lenof(name); \
7702 } while(0)
125105d1 7703
7704 if (ssh->version == 1) {
62638676 7705 /* Don't bother offering IGNORE if we've decided the remote
7706 * won't cope with it, since we wouldn't bother sending it if
7707 * asked anyway. */
7708 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7709 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7710 } else if (ssh->version == 2) {
786ba75e 7711 ADD_SPECIALS(ssh2_transport_specials);
62638676 7712 if (ssh->mainchan)
7713 ADD_SPECIALS(ssh2_session_specials);
7714 } /* else we're not ready yet */
7715
7716 if (i) {
7717 ADD_SPECIALS(specials_end);
7718 return ssh_specials;
7719 } else {
125105d1 7720 return NULL;
62638676 7721 }
7722#undef ADD_SPECIALS
125105d1 7723}
7724
7725/*
6abbf9e3 7726 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7727 * can send an EOF and collect resulting output (e.g. `plink
7728 * hostname sort').
374330e2 7729 */
51470298 7730static void ssh_special(void *handle, Telnet_Special code)
32874aea 7731{
51470298 7732 Ssh ssh = (Ssh) handle;
ff3187f6 7733 struct Packet *pktout;
51470298 7734
6abbf9e3 7735 if (code == TS_EOF) {
51470298 7736 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7737 /*
7738 * Buffer the EOF in case we are pre-SESSION, so we can
7739 * send it as soon as we reach SESSION.
7740 */
7741 if (code == TS_EOF)
51470298 7742 ssh->eof_needed = TRUE;
32874aea 7743 return;
7744 }
51470298 7745 if (ssh->version == 1) {
7746 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7747 } else if (ssh->mainchan) {
ff3187f6 7748 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7749 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7750 ssh2_pkt_send(ssh, pktout);
32874aea 7751 }
7752 logevent("Sent EOF message");
125105d1 7753 } else if (code == TS_PING || code == TS_NOP) {
51470298 7754 if (ssh->state == SSH_STATE_CLOSED
7755 || ssh->state == SSH_STATE_PREPACKET) return;
7756 if (ssh->version == 1) {
7757 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7758 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7759 } else {
ff3187f6 7760 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7761 ssh2_pkt_addstring_start(pktout);
590f6a5f 7762 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7763 }
9442dd57 7764 } else if (code == TS_REKEY) {
7765 if (!ssh->kex_in_progress && ssh->version == 2) {
7766 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7767 " user request", -1, NULL);
7768 }
125105d1 7769 } else if (code == TS_BRK) {
7770 if (ssh->state == SSH_STATE_CLOSED
7771 || ssh->state == SSH_STATE_PREPACKET) return;
7772 if (ssh->version == 1) {
7773 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7774 } else if (ssh->mainchan) {
ff3187f6 7775 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7776 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7777 ssh2_pkt_addstring(pktout, "break");
7778 ssh2_pkt_addbool(pktout, 0);
7779 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7780 ssh2_pkt_send(ssh, pktout);
125105d1 7781 }
6abbf9e3 7782 } else {
6f2d0cde 7783 /* Is is a POSIX signal? */
7784 char *signame = NULL;
7785 if (code == TS_SIGABRT) signame = "ABRT";
7786 if (code == TS_SIGALRM) signame = "ALRM";
7787 if (code == TS_SIGFPE) signame = "FPE";
7788 if (code == TS_SIGHUP) signame = "HUP";
7789 if (code == TS_SIGILL) signame = "ILL";
7790 if (code == TS_SIGINT) signame = "INT";
7791 if (code == TS_SIGKILL) signame = "KILL";
7792 if (code == TS_SIGPIPE) signame = "PIPE";
7793 if (code == TS_SIGQUIT) signame = "QUIT";
7794 if (code == TS_SIGSEGV) signame = "SEGV";
7795 if (code == TS_SIGTERM) signame = "TERM";
7796 if (code == TS_SIGUSR1) signame = "USR1";
7797 if (code == TS_SIGUSR2) signame = "USR2";
7798 /* The SSH-2 protocol does in principle support arbitrary named
7799 * signals, including signame@domain, but we don't support those. */
7800 if (signame) {
7801 /* It's a signal. */
7802 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7803 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7804 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7805 ssh2_pkt_addstring(pktout, "signal");
7806 ssh2_pkt_addbool(pktout, 0);
7807 ssh2_pkt_addstring(pktout, signame);
7808 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7809 logeventf(ssh, "Sent signal SIG%s", signame);
7810 }
7811 } else {
7812 /* Never heard of it. Do nothing */
7813 }
6abbf9e3 7814 }
374330e2 7815}
7816
51470298 7817void *new_sock_channel(void *handle, Socket s)
d74d141c 7818{
51470298 7819 Ssh ssh = (Ssh) handle;
d74d141c 7820 struct ssh_channel *c;
3d88e64d 7821 c = snew(struct ssh_channel);
51470298 7822 c->ssh = ssh;
d74d141c 7823
7824 if (c) {
bc240b21 7825 c->remoteid = -1; /* to be set when open confirmed */
51470298 7826 c->localid = alloc_channel_id(ssh);
d74d141c 7827 c->closes = 0;
bc240b21 7828 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7829 c->u.pfd.s = s;
013dd8c0 7830 bufchain_init(&c->v.v2.outbuffer);
51470298 7831 add234(ssh->channels, c);
d74d141c 7832 }
7833 return c;
7834}
7835
5471d09a 7836/*
7837 * This is called when stdout/stderr (the entity to which
7838 * from_backend sends data) manages to clear some backlog.
7839 */
ae9ae89f 7840static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7841{
51470298 7842 Ssh ssh = (Ssh) handle;
7843 if (ssh->version == 1) {
7844 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7845 ssh->v1_stdout_throttling = 0;
7846 ssh1_throttle(ssh, -1);
5471d09a 7847 }
7848 } else {
51470298 7849 if (ssh->mainchan && ssh->mainchan->closes == 0)
7850 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7851 }
7852}
7853
6b78788a 7854void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7855{
7856 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7857 Ssh ssh = c->ssh;
ff3187f6 7858 struct Packet *pktout;
d74d141c 7859
57356d63 7860 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7861
51470298 7862 if (ssh->version == 1) {
7863 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7864 PKT_INT, c->localid,
7865 PKT_STR, hostname,
7866 PKT_INT, port,
31fb1866 7867 /* PKT_STR, <org:orgport>, */
bc240b21 7868 PKT_END);
7869 } else {
ff3187f6 7870 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7871 ssh2_pkt_addstring(pktout, "direct-tcpip");
7872 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7873 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7874 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7875 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7876 ssh2_pkt_addstring(pktout, hostname);
7877 ssh2_pkt_adduint32(pktout, port);
bc240b21 7878 /*
7879 * We make up values for the originator data; partly it's
7880 * too much hassle to keep track, and partly I'm not
7881 * convinced the server should be told details like that
7882 * about my local network configuration.
7883 */
ff3187f6 7884 ssh2_pkt_addstring(pktout, "client-side-connection");
7885 ssh2_pkt_adduint32(pktout, 0);
7886 ssh2_pkt_send(ssh, pktout);
bc240b21 7887 }
d74d141c 7888}
7889
51470298 7890static Socket ssh_socket(void *handle)
32874aea 7891{
51470298 7892 Ssh ssh = (Ssh) handle;
7893 return ssh->s;
32874aea 7894}
8ccc75b0 7895
51470298 7896static int ssh_sendok(void *handle)
32874aea 7897{
51470298 7898 Ssh ssh = (Ssh) handle;
7899 return ssh->send_ok;
32874aea 7900}
fb09bf1c 7901
51470298 7902static int ssh_ldisc(void *handle, int option)
32874aea 7903{
51470298 7904 Ssh ssh = (Ssh) handle;
32874aea 7905 if (option == LD_ECHO)
51470298 7906 return ssh->echoing;
32874aea 7907 if (option == LD_EDIT)
51470298 7908 return ssh->editing;
0965bee0 7909 return FALSE;
7910}
7911
b9d7bcad 7912static void ssh_provide_ldisc(void *handle, void *ldisc)
7913{
7914 Ssh ssh = (Ssh) handle;
7915 ssh->ldisc = ldisc;
7916}
7917
a8327734 7918static void ssh_provide_logctx(void *handle, void *logctx)
7919{
7920 Ssh ssh = (Ssh) handle;
7921 ssh->logctx = logctx;
7922}
7923
51470298 7924static int ssh_return_exitcode(void *handle)
7925{
7926 Ssh ssh = (Ssh) handle;
3bb2f322 7927 if (ssh->s != NULL)
7928 return -1;
7929 else
7930 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7931}
7932
7933/*
f89c3294 7934 * cfg_info for SSH is the currently running version of the
7935 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7936 */
7937static int ssh_cfg_info(void *handle)
7938{
7939 Ssh ssh = (Ssh) handle;
7940 return ssh->version;
7941}
7942
7943/*
51470298 7944 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7945 * that fails. This variable is the means by which scp.c can reach
7946 * into the SSH code and find out which one it got.
7947 */
7948extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7949{
51470298 7950 Ssh ssh = (Ssh) handle;
7951 return ssh->fallback_cmd;
d8d6c7e5 7952}
7953
374330e2 7954Backend ssh_backend = {
7955 ssh_init,
fabd1805 7956 ssh_free,
86916870 7957 ssh_reconfig,
374330e2 7958 ssh_send,
5471d09a 7959 ssh_sendbuffer,
374330e2 7960 ssh_size,
4017be6d 7961 ssh_special,
125105d1 7962 ssh_get_specials,
8ccc75b0 7963 ssh_socket,
d8d6c7e5 7964 ssh_return_exitcode,
97db3be4 7965 ssh_sendok,
0965bee0 7966 ssh_ldisc,
b9d7bcad 7967 ssh_provide_ldisc,
a8327734 7968 ssh_provide_logctx,
5471d09a 7969 ssh_unthrottle,
f89c3294 7970 ssh_cfg_info,
97db3be4 7971 22
bc240b21 7972};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator