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Richard points out that it would probably help if I committed
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 21
247308b5 22/* logevent, only printf-formatted. */
23void logeventf(char *fmt, ...)
24{
25 va_list ap;
26 char stuff[200];
27
28 va_start(ap, fmt);
29 vsprintf(stuff, fmt, ap);
30 va_end(ap);
31 logevent(stuff);
32}
33
51470298 34#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
35 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
247308b5 36 logeventf msg, connection_fatal msg )
8d5de777 37
32874aea 38#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41#define SSH1_CMSG_USER 4 /* 0x4 */
42#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50#define SSH1_SMSG_SUCCESS 14 /* 0xe */
51#define SSH1_SMSG_FAILURE 15 /* 0xf */
52#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55#define SSH1_CMSG_EOF 19 /* 0x13 */
56#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67#define SSH1_MSG_IGNORE 32 /* 0x20 */
68#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71#define SSH1_MSG_DEBUG 36 /* 0x24 */
72#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
79
80#define SSH1_AUTH_TIS 5 /* 0x5 */
81#define SSH1_AUTH_CCARD 16 /* 0x10 */
82
83#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 84/* Mask for protoflags we will echo back to server if seen */
32874aea 85#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
86
87#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88#define SSH2_MSG_IGNORE 2 /* 0x2 */
89#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90#define SSH2_MSG_DEBUG 4 /* 0x4 */
91#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93#define SSH2_MSG_KEXINIT 20 /* 0x14 */
94#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 107#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 109#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
123
00db133f 124/*
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
127 */
128#define SSH2_PKTCTX_DHGROUP1 0x0001
129#define SSH2_PKTCTX_DHGEX 0x0002
130#define SSH2_PKTCTX_PUBLICKEY 0x0010
131#define SSH2_PKTCTX_PASSWORD 0x0020
132#define SSH2_PKTCTX_KBDINTER 0x0040
133#define SSH2_PKTCTX_AUTH_MASK 0x00F0
134
32874aea 135#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 150
151static const char *const ssh2_disconnect_reasons[] = {
152 NULL,
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
168};
9005f3ba 169
32874aea 170#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 174
32874aea 175#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 176
7d503c31 177/*
178 * Various remote-bug flags.
179 */
180#define BUG_CHOKES_ON_SSH1_IGNORE 1
181#define BUG_SSH2_HMAC 2
bd358db1 182#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 183#define BUG_CHOKES_ON_RSA 8
1dd353b5 184#define BUG_SSH2_RSA_PADDING 16
088bde77 185#define BUG_SSH2_DERIVEKEY 32
8e975795 186#define BUG_SSH2_DH_GEX 64
bd358db1 187
00db133f 188#define translate(x) if (type == x) return #x
51470298 189#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
00db133f 190char *ssh1_pkt_type(int type)
191{
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
233 return "unknown";
234}
51470298 235char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 236{
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
273 return "unknown";
274}
275#undef translate
276#undef translatec
7d503c31 277
fb09bf1c 278#define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
283
284#define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
289
7cca0d81 290enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 291
374330e2 292/* Coroutine mechanics for the sillier bits of the code */
51470298 293#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
294#define crState(t) \
295 struct t *s; \
296 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
297 s = ssh->t;
298#define crFinish(z) } *crLine = 0; return (z); }
299#define crFinishV } *crLine = 0; return; }
374330e2 300#define crReturn(z) \
301 do {\
51470298 302 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 303 } while (0)
304#define crReturnV \
305 do {\
51470298 306 *crLine=__LINE__; return; case __LINE__:;\
374330e2 307 } while (0)
51470298 308#define crStop(z) do{ *crLine = 0; return (z); }while(0)
309#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 310#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 311#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 312
51470298 313typedef struct ssh_tag *Ssh;
314
302121de 315extern char *x11_init(Socket *, char *, void *, void *);
32874aea 316extern void x11_close(Socket);
5471d09a 317extern int x11_send(Socket, char *, int);
302121de 318extern void *x11_invent_auth(char *, int, char *, int);
5471d09a 319extern void x11_unthrottle(Socket s);
320extern void x11_override_throttle(Socket s, int enable);
9c964e85 321
d74d141c 322extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
6b78788a 323extern char *pfd_addforward(char *desthost, int destport, int port,
324 void *backhandle);
d74d141c 325extern void pfd_close(Socket s);
5471d09a 326extern int pfd_send(Socket s, char *data, int len);
d74d141c 327extern void pfd_confirm(Socket s);
5471d09a 328extern void pfd_unthrottle(Socket s);
329extern void pfd_override_throttle(Socket s, int enable);
330
51470298 331static void ssh2_pkt_init(Ssh, int pkt_type);
332static void ssh2_pkt_addbool(Ssh, unsigned char value);
333static void ssh2_pkt_adduint32(Ssh, unsigned long value);
334static void ssh2_pkt_addstring_start(Ssh);
335static void ssh2_pkt_addstring_str(Ssh, char *data);
336static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
337static void ssh2_pkt_addstring(Ssh, char *data);
3d63ca2e 338static char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 339static void ssh2_pkt_addmp(Ssh, Bignum b);
340static int ssh2_pkt_construct(Ssh);
341static void ssh2_pkt_send(Ssh);
3d63ca2e 342
5471d09a 343/*
344 * Buffer management constants. There are several of these for
345 * various different purposes:
346 *
347 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
348 * on a local data stream before we throttle the whole SSH
349 * connection (in SSH1 only). Throttling the whole connection is
350 * pretty drastic so we set this high in the hope it won't
351 * happen very often.
352 *
353 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
354 * on the SSH connection itself before we defensively throttle
355 * _all_ local data streams. This is pretty drastic too (though
356 * thankfully unlikely in SSH2 since the window mechanism should
357 * ensure that the server never has any need to throttle its end
358 * of the connection), so we set this high as well.
359 *
360 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
361 * channels.
362 */
363
364#define SSH1_BUFFER_LIMIT 32768
365#define SSH_MAX_BACKLOG 32768
366#define OUR_V2_WINSIZE 16384
d74d141c 367
a92dd380 368const static struct ssh_kex *kex_algs[] = {
a92dd380 369 &ssh_diffiehellman_gex,
32874aea 370 &ssh_diffiehellman
371};
e5574168 372
85cc02bb 373const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 374
e0e1a00d 375static void *nullmac_make_context(void)
376{
377 return NULL;
378}
379static void nullmac_free_context(void *handle)
380{
381}
382static void nullmac_key(void *handle, unsigned char *key)
32874aea 383{
384}
e0e1a00d 385static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 386 unsigned long seq)
387{
388}
e0e1a00d 389static int nullmac_verify(void *handle, unsigned char *blk, int len,
390 unsigned long seq)
32874aea 391{
392 return 1;
393}
57476f6b 394const static struct ssh_mac ssh_mac_none = {
e0e1a00d 395 nullmac_make_context, nullmac_free_context, nullmac_key,
396 nullmac_generate, nullmac_verify, "none", 0
e5574168 397};
8b2715b2 398const static struct ssh_mac *macs[] = {
32874aea 399 &ssh_sha1, &ssh_md5, &ssh_mac_none
400};
8b2715b2 401const static struct ssh_mac *buggymacs[] = {
32874aea 402 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
403};
e5574168 404
5366aed8 405static void *ssh_comp_none_init(void)
406{
407 return NULL;
408}
409static void ssh_comp_none_cleanup(void *handle)
32874aea 410{
411}
5366aed8 412static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 413 unsigned char **outblock, int *outlen)
414{
415 return 0;
416}
5366aed8 417static int ssh_comp_none_disable(void *handle)
32874aea 418{
4ba9b64b 419 return 0;
420}
57476f6b 421const static struct ssh_compress ssh_comp_none = {
4ba9b64b 422 "none",
5366aed8 423 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
424 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
425 ssh_comp_none_disable, NULL
e5574168 426};
4ba9b64b 427extern const struct ssh_compress ssh_zlib;
428const static struct ssh_compress *compressions[] = {
32874aea 429 &ssh_zlib, &ssh_comp_none
430};
374330e2 431
32874aea 432enum { /* channel types */
783415f8 433 CHAN_MAINSESSION,
434 CHAN_X11,
435 CHAN_AGENT,
bc240b21 436 CHAN_SOCKDATA,
437 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 438};
439
dacbd0e8 440/*
441 * 2-3-4 tree storing channels.
442 */
443struct ssh_channel {
51470298 444 Ssh ssh; /* pointer back to main context */
d211621f 445 unsigned remoteid, localid;
dacbd0e8 446 int type;
0357890f 447 /*
448 * In SSH1, this value contains four bits:
449 *
450 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
451 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
452 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
453 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
454 *
455 * A channel is completely finished with when all four bits are set.
456 */
dacbd0e8 457 int closes;
5471d09a 458 union {
459 struct ssh1_data_channel {
460 int throttling;
461 } v1;
462 struct ssh2_data_channel {
463 bufchain outbuffer;
464 unsigned remwindow, remmaxpkt;
465 unsigned locwindow;
466 } v2;
467 } v;
dacbd0e8 468 union {
32874aea 469 struct ssh_agent_channel {
470 unsigned char *message;
471 unsigned char msglen[4];
472 int lensofar, totallen;
473 } a;
474 struct ssh_x11_channel {
475 Socket s;
476 } x11;
d74d141c 477 struct ssh_pfd_channel {
478 Socket s;
479 } pfd;
dacbd0e8 480 } u;
481};
57476f6b 482
d74d141c 483/*
bc240b21 484 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
485 * 2 use this structure in different ways, reflecting SSH 2's
486 * altogether saner approach to port forwarding.
487 *
488 * In SSH 1, you arrange a remote forwarding by sending the server
489 * the remote port number, and the local destination host:port.
490 * When a connection comes in, the server sends you back that
491 * host:port pair, and you connect to it. This is a ready-made
492 * security hole if you're not on the ball: a malicious server
493 * could send you back _any_ host:port pair, so if you trustingly
494 * connect to the address it gives you then you've just opened the
495 * entire inside of your corporate network just by connecting
496 * through it to a dodgy SSH server. Hence, we must store a list of
497 * host:port pairs we _are_ trying to forward to, and reject a
498 * connection request from the server if it's not in the list.
499 *
500 * In SSH 2, each side of the connection minds its own business and
501 * doesn't send unnecessary information to the other. You arrange a
502 * remote forwarding by sending the server just the remote port
503 * number. When a connection comes in, the server tells you which
504 * of its ports was connected to; and _you_ have to remember what
505 * local host:port pair went with that port number.
506 *
507 * Hence: in SSH 1 this structure stores host:port pairs we intend
508 * to allow connections to, and is indexed by those host:port
509 * pairs. In SSH 2 it stores a mapping from source port to
510 * destination host:port pair, and is indexed by source port.
d74d141c 511 */
512struct ssh_rportfwd {
bc240b21 513 unsigned sport, dport;
514 char dhost[256];
d74d141c 515};
516
57476f6b 517struct Packet {
518 long length;
519 int type;
520 unsigned char *data;
521 unsigned char *body;
522 long savedpos;
523 long maxlen;
524};
525
51470298 526static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
527static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
528static void ssh_size(void *handle, int width, int height);
529static void ssh_special(void *handle, Telnet_Special);
5471d09a 530static int ssh2_try_send(struct ssh_channel *c);
51470298 531static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
532static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 533static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 534static int ssh_sendbuffer(void *handle);
57476f6b 535
51470298 536struct rdpkt1_state_tag {
57476f6b 537 long len, pad, biglen, to_read;
538 unsigned long realcrc, gotcrc;
539 unsigned char *p;
540 int i;
541 int chunk;
51470298 542};
57476f6b 543
51470298 544struct rdpkt2_state_tag {
960e736a 545 long len, pad, payload, packetlen, maclen;
546 int i;
547 int cipherblk;
548 unsigned long incoming_sequence;
51470298 549};
550
551struct ssh_tag {
552 const struct plug_function_table *fn;
553 /* the above field _must_ be first in the structure */
554
555 SHA_State exhash, exhashbase;
556
557 Socket s;
558
b9d7bcad 559 void *ldisc;
560
51470298 561 unsigned char session_key[32];
562 int v1_compressing;
563 int v1_remote_protoflags;
564 int v1_local_protoflags;
565 int agentfwd_enabled;
566 int X11_fwd_enabled;
567 int remote_bugs;
568 const struct ssh_cipher *cipher;
371e569c 569 void *v1_cipher_ctx;
0183b242 570 void *crcda_ctx;
51470298 571 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 572 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 573 const struct ssh_mac *csmac, *scmac;
e0e1a00d 574 void *cs_mac_ctx, *sc_mac_ctx;
51470298 575 const struct ssh_compress *cscomp, *sccomp;
5366aed8 576 void *cs_comp_ctx, *sc_comp_ctx;
51470298 577 const struct ssh_kex *kex;
578 const struct ssh_signkey *hostkey;
579 unsigned char v2_session_id[20];
27cd7fc2 580 void *kex_ctx;
51470298 581
582 char *savedhost;
583 int savedport;
584 int send_ok;
585 int echoing, editing;
586
587 void *frontend;
588
589 int term_width, term_height;
590
591 tree234 *channels; /* indexed by local id */
592 struct ssh_channel *mainchan; /* primary session channel */
593 int exitcode;
594
595 tree234 *rportfwds;
596
597 enum {
598 SSH_STATE_PREPACKET,
599 SSH_STATE_BEFORE_SIZE,
600 SSH_STATE_INTERMED,
601 SSH_STATE_SESSION,
602 SSH_STATE_CLOSED
603 } state;
604
605 int size_needed, eof_needed;
606
607 struct Packet pktin;
608 struct Packet pktout;
609 unsigned char *deferred_send_data;
610 int deferred_len, deferred_size;
611
612 /*
613 * Gross hack: pscp will try to start SFTP but fall back to
614 * scp1 if that fails. This variable is the means by which
615 * scp.c can reach into the SSH code and find out which one it
616 * got.
617 */
618 int fallback_cmd;
619
620 /*
621 * Used for username and password input.
622 */
623 char *userpass_input_buffer;
624 int userpass_input_buflen;
625 int userpass_input_bufpos;
626 int userpass_input_echo;
627
628 char *portfwd_strptr;
629 int pkt_ctx;
630
302121de 631 void *x11auth;
632
51470298 633 int version;
634 int v1_throttle_count;
635 int overall_bufsize;
636 int throttled_all;
637 int v1_stdout_throttling;
638 int v2_outgoing_sequence;
639
640 int ssh1_rdpkt_crstate;
641 int ssh2_rdpkt_crstate;
642 int do_ssh_init_crstate;
643 int ssh_gotdata_crstate;
644 int ssh1_protocol_crstate;
645 int do_ssh1_login_crstate;
646 int do_ssh2_transport_crstate;
647 int do_ssh2_authconn_crstate;
648
649 void *do_ssh_init_state;
650 void *do_ssh1_login_state;
651 void *do_ssh2_transport_state;
652 void *do_ssh2_authconn_state;
653
654 struct rdpkt1_state_tag rdpkt1_state;
655 struct rdpkt2_state_tag rdpkt2_state;
656
657 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
658 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
659};
960e736a 660
32874aea 661static int ssh_channelcmp(void *av, void *bv)
662{
663 struct ssh_channel *a = (struct ssh_channel *) av;
664 struct ssh_channel *b = (struct ssh_channel *) bv;
665 if (a->localid < b->localid)
666 return -1;
667 if (a->localid > b->localid)
668 return +1;
dacbd0e8 669 return 0;
670}
32874aea 671static int ssh_channelfind(void *av, void *bv)
672{
673 unsigned *a = (unsigned *) av;
674 struct ssh_channel *b = (struct ssh_channel *) bv;
675 if (*a < b->localid)
676 return -1;
677 if (*a > b->localid)
678 return +1;
dacbd0e8 679 return 0;
680}
681
bc240b21 682static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 683{
684 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
685 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
686 int i;
bc240b21 687 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 688 return i < 0 ? -1 : +1;
bc240b21 689 if (a->dport > b->dport)
690 return +1;
691 if (a->dport < b->dport)
692 return -1;
693 return 0;
694}
695
696static int ssh_rportcmp_ssh2(void *av, void *bv)
697{
698 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
699 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 700
bc240b21 701 if (a->sport > b->sport)
d74d141c 702 return +1;
bc240b21 703 if (a->sport < b->sport)
704 return -1;
d74d141c 705 return 0;
706}
707
51470298 708static int alloc_channel_id(Ssh ssh)
32874aea 709{
260f3dec 710 const unsigned CHANNEL_NUMBER_OFFSET = 256;
711 unsigned low, high, mid;
d2371c81 712 int tsize;
713 struct ssh_channel *c;
714
715 /*
716 * First-fit allocation of channel numbers: always pick the
717 * lowest unused one. To do this, binary-search using the
718 * counted B-tree to find the largest channel ID which is in a
719 * contiguous sequence from the beginning. (Precisely
720 * everything in that sequence must have ID equal to its tree
721 * index plus CHANNEL_NUMBER_OFFSET.)
722 */
51470298 723 tsize = count234(ssh->channels);
d2371c81 724
32874aea 725 low = -1;
726 high = tsize;
d2371c81 727 while (high - low > 1) {
728 mid = (high + low) / 2;
51470298 729 c = index234(ssh->channels, mid);
d2371c81 730 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
731 low = mid; /* this one is fine */
732 else
733 high = mid; /* this one is past it */
734 }
735 /*
736 * Now low points to either -1, or the tree index of the
737 * largest ID in the initial sequence.
738 */
739 {
740 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 741 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 742 }
743 return low + 1 + CHANNEL_NUMBER_OFFSET;
744}
745
51470298 746static void c_write(Ssh ssh, char *buf, int len)
32874aea 747{
67779be7 748 if ((flags & FLAG_STDERR)) {
32874aea 749 int i;
750 for (i = 0; i < len; i++)
751 if (buf[i] != '\r')
752 fputc(buf[i], stderr);
fb09bf1c 753 return;
754 }
51470298 755 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 756}
757
51470298 758static void c_write_untrusted(Ssh ssh, char *buf, int len)
32874aea 759{
a209e957 760 int i;
761 for (i = 0; i < len; i++) {
32874aea 762 if (buf[i] == '\n')
51470298 763 c_write(ssh, "\r\n", 2);
32874aea 764 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 765 c_write(ssh, buf + i, 1);
a209e957 766 }
767}
768
51470298 769static void c_write_str(Ssh ssh, char *buf)
32874aea 770{
51470298 771 c_write(ssh, buf, strlen(buf));
1408a877 772}
773
fb09bf1c 774/*
775 * Collect incoming data in the incoming packet buffer.
e5574168 776 * Decipher and verify the packet when it is completely read.
777 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 778 * Update the *data and *datalen variables.
779 * Return the additional nr of bytes needed, or 0 when
780 * a complete packet is available.
781 */
51470298 782static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 783{
51470298 784 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 785
51470298 786 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 787
32874aea 788 next_packet:
37508af4 789
51470298 790 ssh->pktin.type = 0;
791 ssh->pktin.length = 0;
374330e2 792
57476f6b 793 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 794 while ((*datalen) == 0)
32874aea 795 crReturn(4 - st->i);
57476f6b 796 st->len = (st->len << 8) + **data;
fb09bf1c 797 (*data)++, (*datalen)--;
798 }
374330e2 799
57476f6b 800 st->pad = 8 - (st->len % 8);
801 st->biglen = st->len + st->pad;
51470298 802 ssh->pktin.length = st->len - 5;
fb09bf1c 803
51470298 804 if (ssh->pktin.maxlen < st->biglen) {
805 ssh->pktin.maxlen = st->biglen;
806 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
fb09bf1c 807 }
374330e2 808
57476f6b 809 st->to_read = st->biglen;
51470298 810 st->p = ssh->pktin.data;
57476f6b 811 while (st->to_read > 0) {
32874aea 812 st->chunk = st->to_read;
fb09bf1c 813 while ((*datalen) == 0)
57476f6b 814 crReturn(st->to_read);
815 if (st->chunk > (*datalen))
816 st->chunk = (*datalen);
817 memcpy(st->p, *data, st->chunk);
818 *data += st->chunk;
819 *datalen -= st->chunk;
820 st->p += st->chunk;
821 st->to_read -= st->chunk;
fb09bf1c 822 }
374330e2 823
0183b242 824 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
825 st->biglen, NULL)) {
9a3a93a5 826 bombout(("Network attack (CRC compensation) detected!"));
827 crReturn(0);
828 }
829
51470298 830 if (ssh->cipher)
371e569c 831 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 832
51470298 833 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
834 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 835 if (st->gotcrc != st->realcrc) {
8d5de777 836 bombout(("Incorrect CRC received on packet"));
32874aea 837 crReturn(0);
fb09bf1c 838 }
572f871e 839
51470298 840 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 841
51470298 842 if (ssh->v1_compressing) {
4ba9b64b 843 unsigned char *decompblk;
844 int decomplen;
5366aed8 845 zlib_decompress_block(ssh->sc_comp_ctx,
846 ssh->pktin.body - 1, ssh->pktin.length + 1,
4ba9b64b 847 &decompblk, &decomplen);
848
51470298 849 if (ssh->pktin.maxlen < st->pad + decomplen) {
850 ssh->pktin.maxlen = st->pad + decomplen;
851 ssh->pktin.data = srealloc(ssh->pktin.data,
852 ssh->pktin.maxlen + APIEXTRA);
853 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 854 }
855
51470298 856 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 857 sfree(decompblk);
51470298 858 ssh->pktin.length = decomplen - 1;
4ba9b64b 859 }
860
51470298 861 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 862
51470298 863 log_packet(PKT_INCOMING, ssh->pktin.type, ssh1_pkt_type(ssh->pktin.type),
864 ssh->pktin.body, ssh->pktin.length);
00db133f 865
51470298 866 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
867 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
868 ssh->pktin.type == SSH1_MSG_DEBUG ||
869 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
870 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
871 long stringlen = GET_32BIT(ssh->pktin.body);
872 if (stringlen + 4 != ssh->pktin.length) {
8d5de777 873 bombout(("Received data packet with bogus string length"));
32874aea 874 crReturn(0);
875 }
fb09bf1c 876 }
877
51470298 878 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 879 /* log debug message */
eb4504cc 880 char buf[512];
51470298 881 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 882 strcpy(buf, "Remote debug message: ");
883 if (stringlen > 480)
884 stringlen = 480;
51470298 885 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 886 buf[8 + stringlen] = '\0';
fb09bf1c 887 logevent(buf);
888 goto next_packet;
51470298 889 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 890 /* do nothing */
891 goto next_packet;
892 }
893
51470298 894 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 895 /* log reason code in disconnect message */
896 char buf[256];
51470298 897 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 898 unsigned nowlen;
38c4a8da 899 strcpy(buf, "Remote sent disconnect: ");
900 nowlen = strlen(buf);
32874aea 901 if (msglen > sizeof(buf) - nowlen - 1)
902 msglen = sizeof(buf) - nowlen - 1;
51470298 903 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 904 buf[nowlen + msglen] = '\0';
247308b5 905 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 906 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 907 crReturn(0);
38c4a8da 908 }
909
fb09bf1c 910 crFinish(0);
911}
912
51470298 913static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 914{
51470298 915 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 916
51470298 917 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 918
32874aea 919 next_packet:
51470298 920 ssh->pktin.type = 0;
921 ssh->pktin.length = 0;
922 if (ssh->sccipher)
923 st->cipherblk = ssh->sccipher->blksize;
e5574168 924 else
32874aea 925 st->cipherblk = 8;
960e736a 926 if (st->cipherblk < 8)
32874aea 927 st->cipherblk = 8;
960e736a 928
51470298 929 if (ssh->pktin.maxlen < st->cipherblk) {
930 ssh->pktin.maxlen = st->cipherblk;
931 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
e5574168 932 }
933
934 /*
935 * Acquire and decrypt the first block of the packet. This will
936 * contain the length and padding details.
937 */
32874aea 938 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 939 while ((*datalen) == 0)
32874aea 940 crReturn(st->cipherblk - st->i);
51470298 941 ssh->pktin.data[st->i] = *(*data)++;
32874aea 942 (*datalen)--;
e5574168 943 }
4252c9cc 944
51470298 945 if (ssh->sccipher)
371e569c 946 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
947 ssh->pktin.data, st->cipherblk);
e5574168 948
949 /*
950 * Now get the length and padding figures.
951 */
51470298 952 st->len = GET_32BIT(ssh->pktin.data);
953 st->pad = ssh->pktin.data[4];
e5574168 954
955 /*
717dc483 956 * _Completely_ silly lengths should be stomped on before they
957 * do us any more damage.
958 */
959 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
960 bombout(("Incoming packet was garbled on decryption"));
961 crReturn(0);
962 }
963
964 /*
e5574168 965 * This enables us to deduce the payload length.
966 */
960e736a 967 st->payload = st->len - st->pad - 1;
e5574168 968
51470298 969 ssh->pktin.length = st->payload + 5;
e5574168 970
971 /*
972 * So now we can work out the total packet length.
973 */
960e736a 974 st->packetlen = st->len + 4;
51470298 975 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 976
977 /*
978 * Adjust memory allocation if packet is too big.
979 */
51470298 980 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
981 ssh->pktin.maxlen = st->packetlen + st->maclen;
982 ssh->pktin.data = srealloc(ssh->pktin.data,
983 ssh->pktin.maxlen + APIEXTRA);
e5574168 984 }
985
986 /*
987 * Read and decrypt the remainder of the packet.
988 */
32874aea 989 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
990 st->i++) {
e5574168 991 while ((*datalen) == 0)
960e736a 992 crReturn(st->packetlen + st->maclen - st->i);
51470298 993 ssh->pktin.data[st->i] = *(*data)++;
32874aea 994 (*datalen)--;
e5574168 995 }
996 /* Decrypt everything _except_ the MAC. */
51470298 997 if (ssh->sccipher)
371e569c 998 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
999 ssh->pktin.data + st->cipherblk,
51470298 1000 st->packetlen - st->cipherblk);
e5574168 1001
1002 /*
1003 * Check the MAC.
1004 */
51470298 1005 if (ssh->scmac
e0e1a00d 1006 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1007 st->incoming_sequence)) {
8d5de777 1008 bombout(("Incorrect MAC received on packet"));
32874aea 1009 crReturn(0);
8d5de777 1010 }
32874aea 1011 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1012
4ba9b64b 1013 /*
1014 * Decompress packet payload.
1015 */
1016 {
1017 unsigned char *newpayload;
1018 int newlen;
51470298 1019 if (ssh->sccomp &&
5366aed8 1020 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1021 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1022 &newpayload, &newlen)) {
1023 if (ssh->pktin.maxlen < newlen + 5) {
1024 ssh->pktin.maxlen = newlen + 5;
1025 ssh->pktin.data = srealloc(ssh->pktin.data,
1026 ssh->pktin.maxlen + APIEXTRA);
4ba9b64b 1027 }
51470298 1028 ssh->pktin.length = 5 + newlen;
1029 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1030 sfree(newpayload);
4ba9b64b 1031 }
1032 }
1033
51470298 1034 ssh->pktin.savedpos = 6;
1035 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1036
51470298 1037 log_packet(PKT_INCOMING, ssh->pktin.type,
1038 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1039 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1040
51470298 1041 switch (ssh->pktin.type) {
3d63ca2e 1042 /*
1043 * These packets we must handle instantly.
1044 */
1045 case SSH2_MSG_DISCONNECT:
1046 {
1047 /* log reason code in disconnect message */
1048 char buf[256];
51470298 1049 int reason = GET_32BIT(ssh->pktin.data + 6);
1050 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
3d63ca2e 1051 unsigned nowlen;
1052 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1053 sprintf(buf, "Received disconnect message (%s)",
1054 ssh2_disconnect_reasons[reason]);
1055 } else {
1056 sprintf(buf, "Received disconnect message (unknown type %d)",
1057 reason);
1058 }
1059 logevent(buf);
1060 strcpy(buf, "Disconnection message text: ");
1061 nowlen = strlen(buf);
1062 if (msglen > sizeof(buf) - nowlen - 1)
1063 msglen = sizeof(buf) - nowlen - 1;
51470298 1064 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
3d63ca2e 1065 buf[nowlen + msglen] = '\0';
1066 logevent(buf);
1067 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1068 reason,
1069 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1070 ssh2_disconnect_reasons[reason] : "unknown",
1071 buf+nowlen));
1072 crReturn(0);
1073 }
1074 break;
1075 case SSH2_MSG_IGNORE:
1076 goto next_packet;
1077 case SSH2_MSG_DEBUG:
1078 {
1079 /* log the debug message */
1080 char buf[512];
51470298 1081 /* int display = ssh->pktin.body[6]; */
1082 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1083 int prefix;
1084 strcpy(buf, "Remote debug message: ");
1085 prefix = strlen(buf);
51470298 1086 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1087 stringlen = sizeof(buf)-prefix-1;
51470298 1088 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1089 buf[prefix + stringlen] = '\0';
1090 logevent(buf);
38c4a8da 1091 }
3d63ca2e 1092 goto next_packet; /* FIXME: print the debug message */
1093
1094 /*
1095 * These packets we need do nothing about here.
1096 */
1097 case SSH2_MSG_UNIMPLEMENTED:
1098 case SSH2_MSG_SERVICE_REQUEST:
1099 case SSH2_MSG_SERVICE_ACCEPT:
1100 case SSH2_MSG_KEXINIT:
1101 case SSH2_MSG_NEWKEYS:
1102 case SSH2_MSG_KEXDH_INIT:
1103 case SSH2_MSG_KEXDH_REPLY:
1104 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1105 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1106 case SSH2_MSG_KEX_DH_GEX_INIT:
1107 case SSH2_MSG_KEX_DH_GEX_REPLY:
1108 case SSH2_MSG_USERAUTH_REQUEST:
1109 case SSH2_MSG_USERAUTH_FAILURE:
1110 case SSH2_MSG_USERAUTH_SUCCESS:
1111 case SSH2_MSG_USERAUTH_BANNER:
1112 case SSH2_MSG_USERAUTH_PK_OK:
1113 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1114 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1115 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1116 case SSH2_MSG_GLOBAL_REQUEST:
1117 case SSH2_MSG_REQUEST_SUCCESS:
1118 case SSH2_MSG_REQUEST_FAILURE:
1119 case SSH2_MSG_CHANNEL_OPEN:
1120 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1121 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1122 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1123 case SSH2_MSG_CHANNEL_DATA:
1124 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1125 case SSH2_MSG_CHANNEL_EOF:
1126 case SSH2_MSG_CHANNEL_CLOSE:
1127 case SSH2_MSG_CHANNEL_REQUEST:
1128 case SSH2_MSG_CHANNEL_SUCCESS:
1129 case SSH2_MSG_CHANNEL_FAILURE:
1130 break;
1131
1132 /*
1133 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1134 */
1135 default:
51470298 1136 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1137 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1138 ssh2_pkt_send(ssh);
3d63ca2e 1139 break;
38c4a8da 1140 }
1141
e5574168 1142 crFinish(0);
1143}
1144
51470298 1145static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1146{
374330e2 1147 int pad, biglen;
1148
1149 len += 5; /* type and CRC */
32874aea 1150 pad = 8 - (len % 8);
374330e2 1151 biglen = len + pad;
1152
51470298 1153 ssh->pktout.length = len - 5;
1154 if (ssh->pktout.maxlen < biglen) {
1155 ssh->pktout.maxlen = biglen;
8f203108 1156#ifdef MSCRYPTOAPI
fb09bf1c 1157 /* Allocate enough buffer space for extra block
8f203108 1158 * for MS CryptEncrypt() */
51470298 1159 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
8f203108 1160#else
51470298 1161 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
8f203108 1162#endif
374330e2 1163 }
51470298 1164 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1165}
374330e2 1166
51470298 1167static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1168{
51470298 1169 ssh1_pktout_size(ssh, len);
1170 ssh->pktout.type = type;
374330e2 1171}
1172
51470298 1173static int s_wrpkt_prepare(Ssh ssh)
32874aea 1174{
374330e2 1175 int pad, len, biglen, i;
1176 unsigned long crc;
1177
51470298 1178 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1179
51470298 1180 log_packet(PKT_OUTGOING, ssh->pktout.type, ssh1_pkt_type(ssh->pktout.type),
1181 ssh->pktout.body, ssh->pktout.length);
00db133f 1182
51470298 1183 if (ssh->v1_compressing) {
4ba9b64b 1184 unsigned char *compblk;
1185 int complen;
5366aed8 1186 zlib_compress_block(ssh->cs_comp_ctx,
1187 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1188 &compblk, &complen);
51470298 1189 ssh1_pktout_size(ssh, complen - 1);
1190 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1191 sfree(compblk);
4ba9b64b 1192 }
1193
51470298 1194 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1195 pad = 8 - (len % 8);
374330e2 1196 biglen = len + pad;
1197
32874aea 1198 for (i = 0; i < pad; i++)
51470298 1199 ssh->pktout.data[i + 4] = random_byte();
1200 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1201 PUT_32BIT(ssh->pktout.data + biglen, crc);
1202 PUT_32BIT(ssh->pktout.data, len);
374330e2 1203
51470298 1204 if (ssh->cipher)
371e569c 1205 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1206
32874aea 1207 return biglen + 4;
39065bed 1208}
1209
51470298 1210static void s_wrpkt(Ssh ssh)
32874aea 1211{
5471d09a 1212 int len, backlog;
51470298 1213 len = s_wrpkt_prepare(ssh);
1214 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1215 if (backlog > SSH_MAX_BACKLOG)
51470298 1216 ssh_throttle_all(ssh, 1, backlog);
39065bed 1217}
1218
51470298 1219static void s_wrpkt_defer(Ssh ssh)
32874aea 1220{
39065bed 1221 int len;
51470298 1222 len = s_wrpkt_prepare(ssh);
1223 if (ssh->deferred_len + len > ssh->deferred_size) {
1224 ssh->deferred_size = ssh->deferred_len + len + 128;
1225 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1226 ssh->deferred_size);
39065bed 1227 }
51470298 1228 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1229 ssh->deferred_len += len;
374330e2 1230}
1231
fb09bf1c 1232/*
39065bed 1233 * Construct a packet with the specified contents.
fb09bf1c 1234 */
51470298 1235static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1236{
fb09bf1c 1237 unsigned char *p, *argp, argchar;
1238 unsigned long argint;
1239 int pktlen, argtype, arglen;
7cca0d81 1240 Bignum bn;
fb09bf1c 1241
1242 pktlen = 0;
39065bed 1243 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1244 switch (argtype) {
1245 case PKT_INT:
39065bed 1246 (void) va_arg(ap1, int);
fb09bf1c 1247 pktlen += 4;
1248 break;
1249 case PKT_CHAR:
39065bed 1250 (void) va_arg(ap1, char);
fb09bf1c 1251 pktlen++;
1252 break;
1253 case PKT_DATA:
39065bed 1254 (void) va_arg(ap1, unsigned char *);
1255 arglen = va_arg(ap1, int);
fb09bf1c 1256 pktlen += arglen;
1257 break;
1258 case PKT_STR:
39065bed 1259 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1260 arglen = strlen(argp);
1261 pktlen += 4 + arglen;
1262 break;
7cca0d81 1263 case PKT_BIGNUM:
39065bed 1264 bn = va_arg(ap1, Bignum);
32874aea 1265 pktlen += ssh1_bignum_length(bn);
7cca0d81 1266 break;
fb09bf1c 1267 default:
1268 assert(0);
1269 }
1270 }
fb09bf1c 1271
51470298 1272 s_wrpkt_start(ssh, pkttype, pktlen);
1273 p = ssh->pktout.body;
fb09bf1c 1274
39065bed 1275 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1276 switch (argtype) {
1277 case PKT_INT:
39065bed 1278 argint = va_arg(ap2, int);
fb09bf1c 1279 PUT_32BIT(p, argint);
1280 p += 4;
1281 break;
1282 case PKT_CHAR:
39065bed 1283 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1284 *p = argchar;
1285 p++;
1286 break;
1287 case PKT_DATA:
39065bed 1288 argp = va_arg(ap2, unsigned char *);
1289 arglen = va_arg(ap2, int);
fb09bf1c 1290 memcpy(p, argp, arglen);
1291 p += arglen;
1292 break;
1293 case PKT_STR:
39065bed 1294 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1295 arglen = strlen(argp);
1296 PUT_32BIT(p, arglen);
1297 memcpy(p + 4, argp, arglen);
1298 p += 4 + arglen;
1299 break;
7cca0d81 1300 case PKT_BIGNUM:
39065bed 1301 bn = va_arg(ap2, Bignum);
32874aea 1302 p += ssh1_write_bignum(p, bn);
7cca0d81 1303 break;
fb09bf1c 1304 }
1305 }
39065bed 1306}
fb09bf1c 1307
51470298 1308static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1309{
39065bed 1310 va_list ap1, ap2;
1311 va_start(ap1, pkttype);
1312 va_start(ap2, pkttype);
51470298 1313 construct_packet(ssh, pkttype, ap1, ap2);
1314 s_wrpkt(ssh);
fb09bf1c 1315}
1316
51470298 1317static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1318{
39065bed 1319 va_list ap1, ap2;
1320 va_start(ap1, pkttype);
1321 va_start(ap2, pkttype);
51470298 1322 construct_packet(ssh, pkttype, ap1, ap2);
1323 s_wrpkt_defer(ssh);
39065bed 1324}
1325
32874aea 1326static int ssh_versioncmp(char *a, char *b)
1327{
9697bfd2 1328 char *ae, *be;
1329 unsigned long av, bv;
1330
43aa02a7 1331 av = strtoul(a, &ae, 10);
1332 bv = strtoul(b, &be, 10);
32874aea 1333 if (av != bv)
1334 return (av < bv ? -1 : +1);
1335 if (*ae == '.')
1336 ae++;
1337 if (*be == '.')
1338 be++;
43aa02a7 1339 av = strtoul(ae, &ae, 10);
1340 bv = strtoul(be, &be, 10);
32874aea 1341 if (av != bv)
1342 return (av < bv ? -1 : +1);
9697bfd2 1343 return 0;
1344}
1345
e5574168 1346/*
a92dd380 1347 * Utility routines for putting an SSH-protocol `string' and
1348 * `uint32' into a SHA state.
e5574168 1349 */
1350#include <stdio.h>
32874aea 1351static void sha_string(SHA_State * s, void *str, int len)
1352{
e5574168 1353 unsigned char lenblk[4];
e5574168 1354 PUT_32BIT(lenblk, len);
e5574168 1355 SHA_Bytes(s, lenblk, 4);
e5574168 1356 SHA_Bytes(s, str, len);
1357}
1358
32874aea 1359static void sha_uint32(SHA_State * s, unsigned i)
1360{
a92dd380 1361 unsigned char intblk[4];
1362 PUT_32BIT(intblk, i);
1363 SHA_Bytes(s, intblk, 4);
1364}
1365
7cca0d81 1366/*
1367 * SSH2 packet construction functions.
1368 */
51470298 1369static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1370{
51470298 1371 if (ssh->pktout.maxlen < length) {
1372 ssh->pktout.maxlen = length + 256;
1373 ssh->pktout.data = srealloc(ssh->pktout.data,
1374 ssh->pktout.maxlen + APIEXTRA);
1375 if (!ssh->pktout.data)
32874aea 1376 fatalbox("Out of memory");
7cca0d81 1377 }
783415f8 1378}
51470298 1379static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1380{
51470298 1381 ssh->pktout.length += len;
1382 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1383 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1384}
51470298 1385static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1386{
51470298 1387 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1388}
51470298 1389static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1390{
51470298 1391 ssh->pktout.length = 5;
1392 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1393}
51470298 1394static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1395{
51470298 1396 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1397}
51470298 1398static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1399{
7cca0d81 1400 unsigned char x[4];
1401 PUT_32BIT(x, value);
51470298 1402 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1403}
51470298 1404static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1405{
51470298 1406 ssh2_pkt_adduint32(ssh, 0);
1407 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1408}
51470298 1409static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1410{
51470298 1411 ssh2_pkt_adddata(ssh, data, strlen(data));
1412 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1413 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1414}
51470298 1415static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1416{
51470298 1417 ssh2_pkt_adddata(ssh, data, len);
1418 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1419 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1420}
51470298 1421static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1422{
51470298 1423 ssh2_pkt_addstring_start(ssh);
1424 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1425}
32874aea 1426static char *ssh2_mpint_fmt(Bignum b, int *len)
1427{
7cca0d81 1428 unsigned char *p;
32874aea 1429 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1430 p = smalloc(n + 1);
7cca0d81 1431 if (!p)
32874aea 1432 fatalbox("out of memory");
7cca0d81 1433 p[0] = 0;
3709bfe9 1434 for (i = 1; i <= n; i++)
32874aea 1435 p[i] = bignum_byte(b, n - i);
7cca0d81 1436 i = 0;
32874aea 1437 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1438 i++;
1439 memmove(p, p + i, n + 1 - i);
1440 *len = n + 1 - i;
7cca0d81 1441 return p;
1442}
51470298 1443static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1444{
7cca0d81 1445 unsigned char *p;
1446 int len;
1447 p = ssh2_mpint_fmt(b, &len);
51470298 1448 ssh2_pkt_addstring_start(ssh);
1449 ssh2_pkt_addstring_data(ssh, p, len);
dcbde236 1450 sfree(p);
7cca0d81 1451}
b185170a 1452
1453/*
1454 * Construct an SSH2 final-form packet: compress it, encrypt it,
1455 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1456 * ssh->pktout.data. Total length is returned.
b185170a 1457 */
51470298 1458static int ssh2_pkt_construct(Ssh ssh)
32874aea 1459{
7cca0d81 1460 int cipherblk, maclen, padding, i;
7cca0d81 1461
51470298 1462 log_packet(PKT_OUTGOING, ssh->pktout.data[5],
1463 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1464 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1465
7cca0d81 1466 /*
4ba9b64b 1467 * Compress packet payload.
1468 */
4ba9b64b 1469 {
1470 unsigned char *newpayload;
1471 int newlen;
51470298 1472 if (ssh->cscomp &&
5366aed8 1473 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1474 ssh->pktout.length - 5,
51470298 1475 &newpayload, &newlen)) {
1476 ssh->pktout.length = 5;
1477 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1478 sfree(newpayload);
4ba9b64b 1479 }
1480 }
1481
1482 /*
7cca0d81 1483 * Add padding. At least four bytes, and must also bring total
1484 * length (minus MAC) up to a multiple of the block size.
1485 */
51470298 1486 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1487 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1488 padding = 4;
32874aea 1489 padding +=
51470298 1490 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1491 maclen = ssh->csmac ? ssh->csmac->len : 0;
1492 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1493 ssh->pktout.data[4] = padding;
7cca0d81 1494 for (i = 0; i < padding; i++)
51470298 1495 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1496 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1497 if (ssh->csmac)
e0e1a00d 1498 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1499 ssh->pktout.length + padding,
51470298 1500 ssh->v2_outgoing_sequence);
1501 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1502
1503 if (ssh->cscipher)
371e569c 1504 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1505 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1506
1507 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1508 return ssh->pktout.length + padding + maclen;
b185170a 1509}
1510
1511/*
1512 * Construct and send an SSH2 packet immediately.
1513 */
51470298 1514static void ssh2_pkt_send(Ssh ssh)
32874aea 1515{
5471d09a 1516 int len;
1517 int backlog;
51470298 1518 len = ssh2_pkt_construct(ssh);
1519 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1520 if (backlog > SSH_MAX_BACKLOG)
51470298 1521 ssh_throttle_all(ssh, 1, backlog);
b185170a 1522}
1523
1524/*
1525 * Construct an SSH2 packet and add it to a deferred data block.
1526 * Useful for sending multiple packets in a single sk_write() call,
1527 * to prevent a traffic-analysing listener from being able to work
1528 * out the length of any particular packet (such as the password
1529 * packet).
1530 *
1531 * Note that because SSH2 sequence-numbers its packets, this can
1532 * NOT be used as an m4-style `defer' allowing packets to be
1533 * constructed in one order and sent in another.
1534 */
51470298 1535static void ssh2_pkt_defer(Ssh ssh)
32874aea 1536{
51470298 1537 int len = ssh2_pkt_construct(ssh);
1538 if (ssh->deferred_len + len > ssh->deferred_size) {
1539 ssh->deferred_size = ssh->deferred_len + len + 128;
1540 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1541 ssh->deferred_size);
b185170a 1542 }
51470298 1543 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1544 ssh->deferred_len += len;
b185170a 1545}
1546
1547/*
1548 * Send the whole deferred data block constructed by
39065bed 1549 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1550 */
51470298 1551static void ssh_pkt_defersend(Ssh ssh)
32874aea 1552{
5471d09a 1553 int backlog;
51470298 1554 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1555 ssh->deferred_len = ssh->deferred_size = 0;
1556 sfree(ssh->deferred_send_data);
1557 ssh->deferred_send_data = NULL;
5471d09a 1558 if (backlog > SSH_MAX_BACKLOG)
51470298 1559 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1560}
1561
1562#if 0
32874aea 1563void bndebug(char *string, Bignum b)
1564{
7cca0d81 1565 unsigned char *p;
1566 int i, len;
1567 p = ssh2_mpint_fmt(b, &len);
1568 debug(("%s", string));
1569 for (i = 0; i < len; i++)
32874aea 1570 debug((" %02x", p[i]));
765c4200 1571 debug(("\n"));
dcbde236 1572 sfree(p);
7cca0d81 1573}
1574#endif
1575
32874aea 1576static void sha_mpint(SHA_State * s, Bignum b)
1577{
7cca0d81 1578 unsigned char *p;
1579 int len;
1580 p = ssh2_mpint_fmt(b, &len);
1581 sha_string(s, p, len);
dcbde236 1582 sfree(p);
7cca0d81 1583}
1584
1585/*
1586 * SSH2 packet decode functions.
1587 */
51470298 1588static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1589{
7cca0d81 1590 unsigned long value;
51470298 1591 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1592 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1593 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1594 ssh->pktin.savedpos += 4;
7cca0d81 1595 return value;
1596}
51470298 1597static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1598{
65a22376 1599 unsigned long value;
51470298 1600 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1601 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1602 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1603 ssh->pktin.savedpos++;
65a22376 1604 return value;
1605}
51470298 1606static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1607{
7cca0d81 1608 *p = NULL;
45068b27 1609 *length = 0;
51470298 1610 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1611 return;
51470298 1612 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1613 ssh->pktin.savedpos += 4;
1614 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1615 return;
51470298 1616 *p = ssh->pktin.data + ssh->pktin.savedpos;
1617 ssh->pktin.savedpos += *length;
7cca0d81 1618}
51470298 1619static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1620{
7cca0d81 1621 char *p;
3709bfe9 1622 int length;
7cca0d81 1623 Bignum b;
1624
51470298 1625 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1626 if (!p)
32874aea 1627 return NULL;
8d5de777 1628 if (p[0] & 0x80) {
32874aea 1629 bombout(("internal error: Can't handle negative mpints"));
1630 return NULL;
8d5de777 1631 }
3709bfe9 1632 b = bignum_from_bytes(p, length);
7cca0d81 1633 return b;
1634}
1635
7d503c31 1636/*
1dd353b5 1637 * Helper function to add an SSH2 signature blob to a packet.
1638 * Expects to be shown the public key blob as well as the signature
1639 * blob. Normally works just like ssh2_pkt_addstring, but will
1640 * fiddle with the signature packet if necessary for
1641 * BUG_SSH2_RSA_PADDING.
1642 */
51470298 1643static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1644 void *sigblob_v, int sigblob_len)
1645{
1646 unsigned char *pkblob = (unsigned char *)pkblob_v;
1647 unsigned char *sigblob = (unsigned char *)sigblob_v;
1648
1649 /* dmemdump(pkblob, pkblob_len); */
1650 /* dmemdump(sigblob, sigblob_len); */
1651
1652 /*
1653 * See if this is in fact an ssh-rsa signature and a buggy
1654 * server; otherwise we can just do this the easy way.
1655 */
51470298 1656 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1657 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1658 int pos, len, siglen;
1659
1660 /*
1661 * Find the byte length of the modulus.
1662 */
1663
1664 pos = 4+7; /* skip over "ssh-rsa" */
1665 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1666 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1667 pos += 4; /* find modulus itself */
1668 while (len > 0 && pkblob[pos] == 0)
1669 len--, pos++;
1670 /* debug(("modulus length is %d\n", len)); */
1671
1672 /*
1673 * Now find the signature integer.
1674 */
1675 pos = 4+7; /* skip over "ssh-rsa" */
1676 siglen = GET_32BIT(sigblob+pos);
1677 /* debug(("signature length is %d\n", siglen)); */
1678
1679 if (len != siglen) {
1680 unsigned char newlen[4];
51470298 1681 ssh2_pkt_addstring_start(ssh);
1682 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1dd353b5 1683 /* dmemdump(sigblob, pos); */
1684 pos += 4; /* point to start of actual sig */
1685 PUT_32BIT(newlen, len);
51470298 1686 ssh2_pkt_addstring_data(ssh, newlen, 4);
1dd353b5 1687 /* dmemdump(newlen, 4); */
1688 newlen[0] = 0;
1689 while (len-- > siglen) {
51470298 1690 ssh2_pkt_addstring_data(ssh, newlen, 1);
1dd353b5 1691 /* dmemdump(newlen, 1); */
1692 }
51470298 1693 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1dd353b5 1694 /* dmemdump(sigblob+pos, siglen); */
1695 return;
1696 }
1697
1698 /* Otherwise fall through and do it the easy way. */
1699 }
1700
51470298 1701 ssh2_pkt_addstring_start(ssh);
1702 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1dd353b5 1703}
1704
1705/*
7d503c31 1706 * Examine the remote side's version string and compare it against
1707 * a list of known buggy implementations.
1708 */
51470298 1709static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1710{
1711 char *imp; /* pointer to implementation part */
7d503c31 1712 imp = vstring;
1713 imp += strcspn(imp, "-");
bd358db1 1714 if (*imp) imp++;
7d503c31 1715 imp += strcspn(imp, "-");
bd358db1 1716 if (*imp) imp++;
7d503c31 1717
51470298 1718 ssh->remote_bugs = 0;
7d503c31 1719
2c9c6388 1720 if (cfg.sshbug_ignore1 == BUG_ON ||
1721 (cfg.sshbug_ignore1 == BUG_AUTO &&
1722 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1723 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1724 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1725 /*
1726 * These versions don't support SSH1_MSG_IGNORE, so we have
1727 * to use a different defence against password length
1728 * sniffing.
1729 */
51470298 1730 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1731 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1732 }
1733
2c9c6388 1734 if (cfg.sshbug_plainpw1 == BUG_ON ||
1735 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1736 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1737 /*
1738 * These versions need a plain password sent; they can't
1739 * handle having a null and a random length of data after
1740 * the password.
1741 */
51470298 1742 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1743 logevent("We believe remote version needs a plain SSH1 password");
1744 }
1745
2c9c6388 1746 if (cfg.sshbug_rsa1 == BUG_ON ||
1747 (cfg.sshbug_rsa1 == BUG_AUTO &&
1748 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1749 /*
1750 * These versions apparently have no clue whatever about
1751 * RSA authentication and will panic and die if they see
1752 * an AUTH_RSA message.
1753 */
51470298 1754 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1755 logevent("We believe remote version can't handle RSA authentication");
1756 }
1757
2c9c6388 1758 if (cfg.sshbug_hmac2 == BUG_ON ||
1759 (cfg.sshbug_hmac2 == BUG_AUTO &&
1760 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1761 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1762 !strncmp(imp, "2.1 ", 4)))) {
32874aea 1763 /*
1764 * These versions have the HMAC bug.
1765 */
51470298 1766 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1767 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1768 }
1dd353b5 1769
2c9c6388 1770 if (cfg.sshbug_derivekey2 == BUG_ON ||
1771 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1772 (!strncmp(imp, "2.0.", 4)))) {
088bde77 1773 /*
1774 * These versions have the key-derivation bug (failing to
1775 * include the literal shared secret in the hashes that
1776 * generate the keys).
1777 */
51470298 1778 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1779 logevent("We believe remote version has SSH2 key-derivation bug");
1780 }
1781
2c9c6388 1782 if (cfg.sshbug_rsapad2 == BUG_ON ||
1783 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1784 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1785 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1dd353b5 1786 /*
1787 * These versions have the SSH2 RSA padding bug.
1788 */
51470298 1789 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1790 logevent("We believe remote version has SSH2 RSA padding bug");
1791 }
8e975795 1792
1793 if (cfg.sshbug_dhgex2 == BUG_ON) {
1794 /*
1795 * These versions have the SSH2 DH GEX bug.
1796 */
51470298 1797 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1798 logevent("We believe remote version has SSH2 DH group exchange bug");
1799 }
7d503c31 1800}
1801
51470298 1802static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1803{
51470298 1804 struct do_ssh_init_state {
1805 int vslen;
1806 char version[10];
1807 char *vstring;
1808 int vstrsize;
1809 int i;
1810 int proto1, proto2;
1811 };
1812 crState(do_ssh_init_state);
374330e2 1813
51470298 1814 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1815
1816 /* Search for the string "SSH-" in the input. */
51470298 1817 s->i = 0;
8df7a775 1818 while (1) {
1819 static const int transS[] = { 1, 2, 2, 1 };
1820 static const int transH[] = { 0, 0, 3, 0 };
1821 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1822 if (c == 'S')
51470298 1823 s->i = transS[s->i];
32874aea 1824 else if (c == 'H')
51470298 1825 s->i = transH[s->i];
32874aea 1826 else if (c == '-')
51470298 1827 s->i = transminus[s->i];
32874aea 1828 else
51470298 1829 s->i = 0;
1830 if (s->i < 0)
8df7a775 1831 break;
1832 crReturn(1); /* get another character */
374330e2 1833 }
8df7a775 1834
51470298 1835 s->vstrsize = 16;
1836 s->vstring = smalloc(s->vstrsize);
1837 strcpy(s->vstring, "SSH-");
1838 s->vslen = 4;
1839 s->i = 0;
374330e2 1840 while (1) {
8df7a775 1841 crReturn(1); /* get another char */
51470298 1842 if (s->vslen >= s->vstrsize - 1) {
1843 s->vstrsize += 16;
1844 s->vstring = srealloc(s->vstring, s->vstrsize);
32874aea 1845 }
51470298 1846 s->vstring[s->vslen++] = c;
1847 if (s->i >= 0) {
374330e2 1848 if (c == '-') {
51470298 1849 s->version[s->i] = '\0';
1850 s->i = -1;
1851 } else if (s->i < sizeof(s->version) - 1)
1852 s->version[s->i++] = c;
32874aea 1853 } else if (c == '\n')
374330e2 1854 break;
1855 }
1856
51470298 1857 ssh->agentfwd_enabled = FALSE;
1858 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1859
51470298 1860 s->vstring[s->vslen] = 0;
1861 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1862 {
1863 char *vlog;
1864 vlog = smalloc(20 + s->vslen);
1865 sprintf(vlog, "Server version: %s", s->vstring);
1866 logevent(vlog);
1867 sfree(vlog);
1868 }
1869 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1870
adf799dd 1871 /*
38d228a2 1872 * Decide which SSH protocol version to support.
adf799dd 1873 */
38d228a2 1874
1875 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1876 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1877 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1878 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1879
51470298 1880 if (cfg.sshprot == 0 && !s->proto1) {
38d228a2 1881 bombout(("SSH protocol version 1 required by user but not provided by server"));
1882 crReturn(0);
1883 }
51470298 1884 if (cfg.sshprot == 3 && !s->proto2) {
38d228a2 1885 bombout(("SSH protocol version 2 required by user but not provided by server"));
1886 crReturn(0);
1887 }
1888
51470298 1889 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1890 /*
38d228a2 1891 * Use v2 protocol.
32874aea 1892 */
1893 char verstring[80], vlog[100];
1894 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1895 SHA_Init(&ssh->exhashbase);
32874aea 1896 /*
1897 * Hash our version string and their version string.
1898 */
51470298 1899 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1900 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1901 sprintf(vlog, "We claim version: %s", verstring);
1902 logevent(vlog);
1903 strcat(verstring, "\n");
1904 logevent("Using SSH protocol version 2");
51470298 1905 sk_write(ssh->s, verstring, strlen(verstring));
1906 ssh->protocol = ssh2_protocol;
1907 ssh->version = 2;
1908 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1909 } else {
32874aea 1910 /*
38d228a2 1911 * Use v1 protocol.
32874aea 1912 */
1913 char verstring[80], vlog[100];
1914 sprintf(verstring, "SSH-%s-%s",
51470298 1915 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1916 sshver);
1917 sprintf(vlog, "We claim version: %s", verstring);
1918 logevent(vlog);
1919 strcat(verstring, "\n");
759712a6 1920
32874aea 1921 logevent("Using SSH protocol version 1");
51470298 1922 sk_write(ssh->s, verstring, strlen(verstring));
1923 ssh->protocol = ssh1_protocol;
1924 ssh->version = 1;
1925 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1926 }
51470298 1927 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1928
51470298 1929 sfree(s->vstring);
50526e47 1930
8df7a775 1931 crFinish(0);
1932}
1933
51470298 1934static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 1935{
51470298 1936 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 1937
1938 /*
1939 * To begin with, feed the characters one by one to the
1940 * protocol initialisation / selection function do_ssh_init().
1941 * When that returns 0, we're done with the initial greeting
1942 * exchange and can move on to packet discipline.
1943 */
1944 while (1) {
51470298 1945 int ret; /* need not be kept across crReturn */
8df7a775 1946 if (datalen == 0)
1947 crReturnV; /* more data please */
51470298 1948 ret = do_ssh_init(ssh, *data);
32874aea 1949 data++;
1950 datalen--;
8df7a775 1951 if (ret == 0)
1952 break;
1953 }
1954
1955 /*
1956 * We emerge from that loop when the initial negotiation is
1957 * over and we have selected an s_rdpkt function. Now pass
1958 * everything to s_rdpkt, and then pass the resulting packets
1959 * to the proper protocol handler.
1960 */
1961 if (datalen == 0)
1962 crReturnV;
1963 while (1) {
1964 while (datalen > 0) {
51470298 1965 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1966 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 1967 return;
1968 }
51470298 1969 ssh->protocol(ssh, NULL, 0, 1);
1970 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 1971 return;
1972 }
1973 }
1974 }
1975 crReturnV;
1976 }
1977 crFinishV;
1978}
1979
32874aea 1980static int ssh_closing(Plug plug, char *error_msg, int error_code,
1981 int calling_back)
1982{
51470298 1983 Ssh ssh = (Ssh) plug;
1984 ssh->state = SSH_STATE_CLOSED;
1985 if (ssh->s) {
1986 sk_close(ssh->s);
1987 ssh->s = NULL;
f3ab576e 1988 }
7e78000d 1989 if (error_msg) {
32874aea 1990 /* A socket error has occurred. */
247308b5 1991 logevent(error_msg);
32874aea 1992 connection_fatal(error_msg);
7e78000d 1993 } else {
1994 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1995 }
7e78000d 1996 return 0;
1997}
1998
32874aea 1999static int ssh_receive(Plug plug, int urgent, char *data, int len)
2000{
51470298 2001 Ssh ssh = (Ssh) plug;
2002 ssh_gotdata(ssh, data, len);
2003 if (ssh->state == SSH_STATE_CLOSED) {
2004 if (ssh->s) {
2005 sk_close(ssh->s);
2006 ssh->s = NULL;
32874aea 2007 }
2008 return 0;
3257deae 2009 }
fef97f43 2010 return 1;
374330e2 2011}
2012
5471d09a 2013static void ssh_sent(Plug plug, int bufsize)
2014{
51470298 2015 Ssh ssh = (Ssh) plug;
5471d09a 2016 /*
2017 * If the send backlog on the SSH socket itself clears, we
2018 * should unthrottle the whole world if it was throttled.
2019 */
2020 if (bufsize < SSH_MAX_BACKLOG)
51470298 2021 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2022}
2023
fb09bf1c 2024/*
8df7a775 2025 * Connect to specified host and port.
2026 * Returns an error message, or NULL on success.
6e1ebb76 2027 * Also places the canonical host name into `realhost'. It must be
2028 * freed by the caller.
8df7a775 2029 */
51470298 2030static char *connect_to_host(Ssh ssh, char *host, int port,
2031 char **realhost, int nodelay)
8df7a775 2032{
51470298 2033 static const struct plug_function_table fn_table = {
7e78000d 2034 ssh_closing,
5471d09a 2035 ssh_receive,
2036 ssh_sent,
2037 NULL
51470298 2038 };
7e78000d 2039
8df7a775 2040 SockAddr addr;
2041 char *err;
8df7a775 2042
51470298 2043 ssh->savedhost = smalloc(1 + strlen(host));
2044 if (!ssh->savedhost)
8df7a775 2045 fatalbox("Out of memory");
51470298 2046 strcpy(ssh->savedhost, host);
8df7a775 2047
2048 if (port < 0)
2049 port = 22; /* default ssh port */
51470298 2050 ssh->savedport = port;
8df7a775 2051
2052 /*
2053 * Try to find host.
2054 */
3ad9d396 2055 {
2056 char buf[200];
2057 sprintf(buf, "Looking up host \"%.170s\"", host);
2058 logevent(buf);
2059 }
8df7a775 2060 addr = sk_namelookup(host, realhost);
32874aea 2061 if ((err = sk_addr_error(addr)))
8df7a775 2062 return err;
2063
8df7a775 2064 /*
2065 * Open socket.
2066 */
3ad9d396 2067 {
2068 char buf[200], addrbuf[100];
2069 sk_getaddr(addr, addrbuf, 100);
2070 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2071 logevent(buf);
2072 }
51470298 2073 ssh->fn = &fn_table;
2074 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2075 if ((err = sk_socket_error(ssh->s))) {
2076 ssh->s = NULL;
8df7a775 2077 return err;
67c4ba2e 2078 }
8df7a775 2079
8df7a775 2080 return NULL;
2081}
2082
2083/*
5471d09a 2084 * Throttle or unthrottle the SSH connection.
2085 */
51470298 2086static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2087{
51470298 2088 int old_count = ssh->v1_throttle_count;
2089 ssh->v1_throttle_count += adjust;
2090 assert(ssh->v1_throttle_count >= 0);
2091 if (ssh->v1_throttle_count && !old_count) {
2092 sk_set_frozen(ssh->s, 1);
2093 } else if (!ssh->v1_throttle_count && old_count) {
2094 sk_set_frozen(ssh->s, 0);
5471d09a 2095 }
2096}
2097
2098/*
2099 * Throttle or unthrottle _all_ local data streams (for when sends
2100 * on the SSH connection itself back up).
2101 */
51470298 2102static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2103{
2104 int i;
2105 struct ssh_channel *c;
2106
51470298 2107 if (enable == ssh->throttled_all)
5471d09a 2108 return;
51470298 2109 ssh->throttled_all = enable;
2110 ssh->overall_bufsize = bufsize;
2111 if (!ssh->channels)
5471d09a 2112 return;
51470298 2113 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2114 switch (c->type) {
2115 case CHAN_MAINSESSION:
2116 /*
2117 * This is treated separately, outside the switch.
2118 */
2119 break;
2120 case CHAN_X11:
2121 x11_override_throttle(c->u.x11.s, enable);
2122 break;
2123 case CHAN_AGENT:
2124 /* Agent channels require no buffer management. */
2125 break;
2126 case CHAN_SOCKDATA:
2127 pfd_override_throttle(c->u.x11.s, enable);
2128 break;
2129 }
2130 }
2131}
2132
2133/*
51470298 2134 * Username and password input, abstracted off into routines
2135 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2136 */
0405e71f 2137
2138/* Set up a username or password input loop on a given buffer. */
51470298 2139void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2140{
51470298 2141 ssh->userpass_input_buffer = buffer;
2142 ssh->userpass_input_buflen = buflen;
2143 ssh->userpass_input_bufpos = 0;
2144 ssh->userpass_input_echo = echo;
0405e71f 2145}
2146
2147/*
2148 * Process some terminal data in the course of username/password
2149 * input. Returns >0 for success (line of input returned in
2150 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2151 * for inconclusive (keep waiting for more input please).
2152 */
51470298 2153int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2154{
2155 char c;
2156
2157 while (inlen--) {
2158 switch (c = *in++) {
2159 case 10:
2160 case 13:
51470298 2161 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2162 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2163 return +1;
2164 break;
2165 case 8:
2166 case 127:
51470298 2167 if (ssh->userpass_input_bufpos > 0) {
2168 if (ssh->userpass_input_echo)
2169 c_write_str(ssh, "\b \b");
2170 ssh->userpass_input_bufpos--;
0405e71f 2171 }
2172 break;
2173 case 21:
2174 case 27:
51470298 2175 while (ssh->userpass_input_bufpos > 0) {
2176 if (ssh->userpass_input_echo)
2177 c_write_str(ssh, "\b \b");
2178 ssh->userpass_input_bufpos--;
0405e71f 2179 }
2180 break;
2181 case 3:
2182 case 4:
2183 return -1;
2184 break;
2185 default:
2186 if (((c >= ' ' && c <= '~') ||
2187 ((unsigned char) c >= 160))
51470298 2188 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2189 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2190 if (ssh->userpass_input_echo)
2191 c_write(ssh, &c, 1);
0405e71f 2192 }
2193 break;
2194 }
2195 }
2196 return 0;
2197}
2198
2199/*
fb09bf1c 2200 * Handle the key exchange and user authentication phases.
2201 */
51470298 2202static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2203{
2d466ffd 2204 int i, j;
374330e2 2205 unsigned char cookie[8];
2206 struct RSAKey servkey, hostkey;
2207 struct MD5Context md5c;
51470298 2208 struct do_ssh1_login_state {
2209 int len;
2210 unsigned char *rsabuf, *keystr1, *keystr2;
2211 unsigned long supported_ciphers_mask, supported_auths_mask;
2212 int tried_publickey, tried_agent;
2213 int tis_auth_refused, ccard_auth_refused;
2214 unsigned char session_id[16];
2215 int cipher_type;
2216 char username[100];
2217 void *publickey_blob;
2218 int publickey_bloblen;
2219 char password[100];
2220 char prompt[200];
2221 int pos;
2222 char c;
2223 int pwpkt_type;
2224 unsigned char request[5], *response, *p;
2225 int responselen;
2226 int keyi, nkeys;
2227 int authed;
2228 struct RSAKey key;
2229 Bignum challenge;
2230 char *commentp;
2231 int commentlen;
2232 };
2233 crState(do_ssh1_login_state);
2234
2235 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2236
32874aea 2237 if (!ispkt)
2238 crWaitUntil(ispkt);
374330e2 2239
51470298 2240 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
8d5de777 2241 bombout(("Public key packet not received"));
32874aea 2242 crReturn(0);
8d5de777 2243 }
374330e2 2244
c5e9c988 2245 logevent("Received public keys");
374330e2 2246
51470298 2247 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2248
51470298 2249 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2250 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2251
c5e9c988 2252 /*
1c2a93c4 2253 * Log the host key fingerprint.
c5e9c988 2254 */
c5e9c988 2255 {
2256 char logmsg[80];
1c2a93c4 2257 logevent("Host key fingerprint is:");
c5e9c988 2258 strcpy(logmsg, " ");
32874aea 2259 hostkey.comment = NULL;
2260 rsa_fingerprint(logmsg + strlen(logmsg),
2261 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2262 logevent(logmsg);
2263 }
2264
51470298 2265 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2266 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2267 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2268
51470298 2269 ssh->v1_local_protoflags =
2270 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2271 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2272
c5e9c988 2273 MD5Init(&md5c);
51470298 2274 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2275 MD5Update(&md5c, s->keystr1, servkey.bytes);
2276 MD5Update(&md5c, ssh->pktin.body, 8);
2277 MD5Final(s->session_id, &md5c);
374330e2 2278
32874aea 2279 for (i = 0; i < 32; i++)
51470298 2280 ssh->session_key[i] = random_byte();
374330e2 2281
51470298 2282 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2283
51470298 2284 s->rsabuf = smalloc(s->len);
2285 if (!s->rsabuf)
374330e2 2286 fatalbox("Out of memory");
2287
89ee5268 2288 /*
2289 * Verify the host key.
2290 */
2291 {
32874aea 2292 /*
2293 * First format the key into a string.
2294 */
2295 int len = rsastr_len(&hostkey);
2296 char fingerprint[100];
2297 char *keystr = smalloc(len);
2298 if (!keystr)
2299 fatalbox("Out of memory");
2300 rsastr_fmt(keystr, &hostkey);
2301 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
51470298 2302 verify_ssh_host_key(ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2303 fingerprint);
2304 sfree(keystr);
2305 }
2306
2307 for (i = 0; i < 32; i++) {
51470298 2308 s->rsabuf[i] = ssh->session_key[i];
374330e2 2309 if (i < 16)
51470298 2310 s->rsabuf[i] ^= s->session_id[i];
374330e2 2311 }
2312
2313 if (hostkey.bytes > servkey.bytes) {
51470298 2314 rsaencrypt(s->rsabuf, 32, &servkey);
2315 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2316 } else {
51470298 2317 rsaencrypt(s->rsabuf, 32, &hostkey);
2318 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2319 }
2320
c5e9c988 2321 logevent("Encrypted session key");
2322
ca20bfcf 2323 {
2324 int cipher_chosen = 0, warn = 0;
2325 char *cipher_string = NULL;
51470298 2326 int i;
ca20bfcf 2327 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2328 int next_cipher = cfg.ssh_cipherlist[i];
2329 if (next_cipher == CIPHER_WARN) {
2330 /* If/when we choose a cipher, warn about it */
2331 warn = 1;
2332 } else if (next_cipher == CIPHER_AES) {
2333 /* XXX Probably don't need to mention this. */
2334 logevent("AES not supported in SSH1, skipping");
2335 } else {
2336 switch (next_cipher) {
51470298 2337 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2338 cipher_string = "3DES"; break;
51470298 2339 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2340 cipher_string = "Blowfish"; break;
51470298 2341 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2342 cipher_string = "single-DES"; break;
2343 }
51470298 2344 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2345 cipher_chosen = 1;
2346 }
2347 }
2348 if (!cipher_chosen) {
51470298 2349 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
ca20bfcf 2350 bombout(("Server violates SSH 1 protocol by not "
2351 "supporting 3DES encryption"));
2352 else
2353 /* shouldn't happen */
2354 bombout(("No supported ciphers found"));
a99a05c0 2355 crReturn(0);
2356 }
ca20bfcf 2357
2358 /* Warn about chosen cipher if necessary. */
2359 if (warn)
2360 askcipher(cipher_string, 0);
bea1ef5f 2361 }
ca20bfcf 2362
51470298 2363 switch (s->cipher_type) {
32874aea 2364 case SSH_CIPHER_3DES:
2365 logevent("Using 3DES encryption");
2366 break;
2367 case SSH_CIPHER_DES:
2368 logevent("Using single-DES encryption");
2369 break;
2370 case SSH_CIPHER_BLOWFISH:
2371 logevent("Using Blowfish encryption");
2372 break;
c5e9c988 2373 }
bea1ef5f 2374
51470298 2375 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2376 PKT_CHAR, s->cipher_type,
32874aea 2377 PKT_DATA, cookie, 8,
51470298 2378 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2379 PKT_DATA, s->rsabuf, s->len,
2380 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2381
c5e9c988 2382 logevent("Trying to enable encryption...");
374330e2 2383
51470298 2384 sfree(s->rsabuf);
374330e2 2385
51470298 2386 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2387 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2388 &ssh_3des);
371e569c 2389 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2390 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2391 {
2392 char buf[256];
2393 sprintf(buf, "Initialised %.200s encryption", ssh->cipher->text_name);
2394 logevent(buf);
2395 }
374330e2 2396
0183b242 2397 ssh->crcda_ctx = crcda_make_context();
2398 logevent("Installing CRC compensation attack detector");
2399
fb09bf1c 2400 crWaitUntil(ispkt);
374330e2 2401
51470298 2402 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2403 bombout(("Encryption not successfully enabled"));
32874aea 2404 crReturn(0);
8d5de777 2405 }
374330e2 2406
c5e9c988 2407 logevent("Successfully started encryption");
2408
374330e2 2409 fflush(stdout);
2410 {
67779be7 2411 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2412 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2413 if (!ssh_get_line("login as: ",
51470298 2414 s->username, sizeof(s->username), FALSE)) {
32874aea 2415 /*
2416 * get_line failed to get a username.
2417 * Terminate.
2418 */
2419 logevent("No username provided. Abandoning session.");
51470298 2420 ssh->state = SSH_STATE_CLOSED;
32874aea 2421 crReturn(1);
2422 }
2423 } else {
51470298 2424 int ret; /* need not be kept over crReturn */
2425 c_write_str(ssh, "login as: ");
2426 ssh->send_ok = 1;
0405e71f 2427
51470298 2428 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2429 do {
32874aea 2430 crWaitUntil(!ispkt);
51470298 2431 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2432 } while (ret == 0);
2433 if (ret < 0)
2434 cleanup_exit(0);
51470298 2435 c_write_str(ssh, "\r\n");
32874aea 2436 }
2437 } else {
51470298 2438 strncpy(s->username, cfg.username, sizeof(s->username));
2439 s->username[sizeof(s->username)-1] = '\0';
374330e2 2440 }
fb09bf1c 2441
51470298 2442 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2443 {
51470298 2444 char userlog[22 + sizeof(s->username)];
2445 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2446 logevent(userlog);
32874aea 2447 if (flags & FLAG_INTERACTIVE &&
2448 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2449 strcat(userlog, "\r\n");
51470298 2450 c_write_str(ssh, userlog);
3c8e959b 2451 }
c5e9c988 2452 }
374330e2 2453 }
2454
fb09bf1c 2455 crWaitUntil(ispkt);
374330e2 2456
51470298 2457 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2458 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2459 s->tried_publickey = s->tried_agent = 1;
0df73905 2460 } else {
51470298 2461 s->tried_publickey = s->tried_agent = 0;
0df73905 2462 }
51470298 2463 s->tis_auth_refused = s->ccard_auth_refused = 0;
396778f1 2464 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2465 if (*cfg.keyfile) {
51470298 2466 if (!rsakey_pubblob(cfg.keyfile,
2467 &s->publickey_blob, &s->publickey_bloblen))
2468 s->publickey_blob = NULL;
396778f1 2469 } else
51470298 2470 s->publickey_blob = NULL;
7cca0d81 2471
51470298 2472 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2473 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2474
51470298 2475 if (agent_exists() && !s->tried_agent) {
32874aea 2476 /*
2477 * Attempt RSA authentication using Pageant.
2478 */
32874aea 2479 void *r;
2480
51470298 2481 s->authed = FALSE;
2482 s->tried_agent = 1;
32874aea 2483 logevent("Pageant is running. Requesting keys.");
2484
2485 /* Request the keys held by the agent. */
51470298 2486 PUT_32BIT(s->request, 1);
2487 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2488 agent_query(s->request, 5, &r, &s->responselen);
2489 s->response = (unsigned char *) r;
2490 if (s->response && s->responselen >= 5 &&
2491 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2492 s->p = s->response + 5;
2493 s->nkeys = GET_32BIT(s->p);
2494 s->p += 4;
32874aea 2495 {
2496 char buf[64];
51470298 2497 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2498 logevent(buf);
2499 }
51470298 2500 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2501 {
2502 char buf[64];
51470298 2503 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2504 logevent(buf);
2505 }
51470298 2506 if (s->publickey_blob &&
2507 !memcmp(s->p, s->publickey_blob,
2508 s->publickey_bloblen)) {
396778f1 2509 logevent("This key matches configured key file");
51470298 2510 s->tried_publickey = 1;
396778f1 2511 }
51470298 2512 s->p += 4;
2513 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2514 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2515 s->commentlen = GET_32BIT(s->p);
2516 s->p += 4;
2517 s->commentp = s->p;
2518 s->p += s->commentlen;
2519 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2520 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2521 crWaitUntil(ispkt);
51470298 2522 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2523 logevent("Key refused");
2524 continue;
2525 }
2526 logevent("Received RSA challenge");
51470298 2527 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2528 {
2529 char *agentreq, *q, *ret;
2d466ffd 2530 void *vret;
32874aea 2531 int len, retlen;
2532 len = 1 + 4; /* message type, bit count */
51470298 2533 len += ssh1_bignum_length(s->key.exponent);
2534 len += ssh1_bignum_length(s->key.modulus);
2535 len += ssh1_bignum_length(s->challenge);
32874aea 2536 len += 16; /* session id */
2537 len += 4; /* response format */
2538 agentreq = smalloc(4 + len);
2539 PUT_32BIT(agentreq, len);
2540 q = agentreq + 4;
2541 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2542 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2543 q += 4;
51470298 2544 q += ssh1_write_bignum(q, s->key.exponent);
2545 q += ssh1_write_bignum(q, s->key.modulus);
2546 q += ssh1_write_bignum(q, s->challenge);
2547 memcpy(q, s->session_id, 16);
32874aea 2548 q += 16;
2549 PUT_32BIT(q, 1); /* response format */
2d466ffd 2550 agent_query(agentreq, len + 4, &vret, &retlen);
2551 ret = vret;
32874aea 2552 sfree(agentreq);
2553 if (ret) {
2554 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2555 logevent("Sending Pageant's response");
51470298 2556 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2557 PKT_DATA, ret + 5, 16,
2558 PKT_END);
2559 sfree(ret);
2560 crWaitUntil(ispkt);
51470298 2561 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2562 logevent
2563 ("Pageant's response accepted");
2564 if (flags & FLAG_VERBOSE) {
51470298 2565 c_write_str(ssh, "Authenticated using"
2566 " RSA key \"");
2567 c_write(ssh, s->commentp,
2568 s->commentlen);
2569 c_write_str(ssh, "\" from agent\r\n");
32874aea 2570 }
51470298 2571 s->authed = TRUE;
32874aea 2572 } else
2573 logevent
2574 ("Pageant's response not accepted");
2575 } else {
2576 logevent
2577 ("Pageant failed to answer challenge");
2578 sfree(ret);
2579 }
2580 } else {
2581 logevent("No reply received from Pageant");
2582 }
2583 }
51470298 2584 freebn(s->key.exponent);
2585 freebn(s->key.modulus);
2586 freebn(s->challenge);
2587 if (s->authed)
32874aea 2588 break;
2589 }
2590 }
51470298 2591 if (s->authed)
32874aea 2592 break;
2593 }
51470298 2594 if (*cfg.keyfile && !s->tried_publickey)
2595 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2596
614a20a0 2597 if (cfg.try_tis_auth &&
51470298 2598 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2599 !s->tis_auth_refused) {
2600 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2601 logevent("Requested TIS authentication");
51470298 2602 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2603 crWaitUntil(ispkt);
51470298 2604 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2605 logevent("TIS authentication declined");
2606 if (flags & FLAG_INTERACTIVE)
51470298 2607 c_write_str(ssh, "TIS authentication refused.\r\n");
2608 s->tis_auth_refused = 1;
614a20a0 2609 continue;
32874aea 2610 } else {
51470298 2611 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2612 logevent("Received TIS challenge");
51470298 2613 if (challengelen > sizeof(s->prompt) - 1)
2614 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2615 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2616 /* Prompt heuristic comes from OpenSSH */
51470298 2617 strncpy(s->prompt + challengelen,
2618 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2619 "": "\r\nResponse: ",
51470298 2620 (sizeof s->prompt) - challengelen);
2621 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2622 }
2623 }
614a20a0 2624 if (cfg.try_tis_auth &&
51470298 2625 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2626 !s->ccard_auth_refused) {
2627 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2628 logevent("Requested CryptoCard authentication");
51470298 2629 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2630 crWaitUntil(ispkt);
51470298 2631 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2632 logevent("CryptoCard authentication declined");
51470298 2633 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2634 s->ccard_auth_refused = 1;
614a20a0 2635 continue;
32874aea 2636 } else {
51470298 2637 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2638 logevent("Received CryptoCard challenge");
51470298 2639 if (challengelen > sizeof(s->prompt) - 1)
2640 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2641 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2642 strncpy(s->prompt + challengelen,
2643 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2644 "" : "\r\nResponse: ",
51470298 2645 sizeof(s->prompt) - challengelen);
2646 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2647 }
2648 }
51470298 2649 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2650 sprintf(s->prompt, "%.90s@%.90s's password: ",
2651 s->username, ssh->savedhost);
32874aea 2652 }
51470298 2653 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2654 char *comment = NULL;
231ee168 2655 int type;
2656 char msgbuf[256];
32874aea 2657 if (flags & FLAG_VERBOSE)
51470298 2658 c_write_str(ssh, "Trying public key authentication.\r\n");
231ee168 2659 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2660 logevent(msgbuf);
2661 type = key_type(cfg.keyfile);
2662 if (type != SSH_KEYTYPE_SSH1) {
2663 sprintf(msgbuf, "Key is of wrong type (%s)",
2664 key_type_to_str(type));
2665 logevent(msgbuf);
51470298 2666 c_write_str(ssh, msgbuf);
2667 c_write_str(ssh, "\r\n");
2668 s->tried_publickey = 1;
231ee168 2669 continue;
2670 }
32874aea 2671 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2672 if (flags & FLAG_VERBOSE)
51470298 2673 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2674 goto tryauth;
2675 }
51470298 2676 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2677 sfree(comment);
2678 }
a52f067e 2679
614a20a0 2680 /*
2681 * Show password prompt, having first obtained it via a TIS
2682 * or CryptoCard exchange if we're doing TIS or CryptoCard
2683 * authentication.
2684 */
fa17a66e 2685 if (ssh_get_line) {
51470298 2686 if (!ssh_get_line(s->prompt, s->password,
2687 sizeof(s->password), TRUE)) {
32874aea 2688 /*
2689 * get_line failed to get a password (for example
2690 * because one was supplied on the command line
2691 * which has already failed to work). Terminate.
2692 */
51470298 2693 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2694 PKT_STR, "No more passwords available to try",
2695 PKT_END);
247308b5 2696 logevent("Unable to authenticate");
2bc6a386 2697 connection_fatal("Unable to authenticate");
51470298 2698 ssh->state = SSH_STATE_CLOSED;
32874aea 2699 crReturn(1);
2700 }
fb09bf1c 2701 } else {
614a20a0 2702 /* Prompt may have come from server. We've munged it a bit, so
2703 * we know it to be zero-terminated at least once. */
51470298 2704 int ret; /* need not be saved over crReturn */
2705 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2706 s->pos = 0;
0405e71f 2707
51470298 2708 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2709 do {
32874aea 2710 crWaitUntil(!ispkt);
51470298 2711 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2712 } while (ret == 0);
2713 if (ret < 0)
2714 cleanup_exit(0);
51470298 2715 c_write_str(ssh, "\r\n");
32874aea 2716 }
2717
2718 tryauth:
51470298 2719 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2720 /*
2721 * Try public key authentication with the specified
2722 * key file.
2723 */
51470298 2724 s->tried_publickey = 1;
2725
2726 {
2727 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2728 if (ret == 0) {
2729 c_write_str(ssh, "Couldn't load private key from ");
2730 c_write_str(ssh, cfg.keyfile);
2731 c_write_str(ssh, ".\r\n");
2732 continue; /* go and try password */
2733 }
2734 if (ret == -1) {
2735 c_write_str(ssh, "Wrong passphrase.\r\n");
2736 s->tried_publickey = 0;
2737 continue; /* try again */
2738 }
32874aea 2739 }
2740
2741 /*
2742 * Send a public key attempt.
2743 */
51470298 2744 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2745 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2746
2747 crWaitUntil(ispkt);
51470298 2748 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2749 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2750 continue; /* go and try password */
2751 }
51470298 2752 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2753 bombout(("Bizarre response to offer of public key"));
2754 crReturn(0);
2755 }
32874aea 2756
51470298 2757 {
2758 int i;
2759 unsigned char buffer[32];
2760 Bignum challenge, response;
2761
2762 ssh1_read_bignum(ssh->pktin.body, &challenge);
2763 response = rsadecrypt(challenge, &s->key);
2764 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2765
51470298 2766 for (i = 0; i < 32; i++) {
2767 buffer[i] = bignum_byte(response, 31 - i);
2768 }
2769
2770 MD5Init(&md5c);
2771 MD5Update(&md5c, buffer, 32);
2772 MD5Update(&md5c, s->session_id, 16);
2773 MD5Final(buffer, &md5c);
32874aea 2774
51470298 2775 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2776 PKT_DATA, buffer, 16, PKT_END);
2777
2778 freebn(challenge);
2779 freebn(response);
2780 }
32874aea 2781
2782 crWaitUntil(ispkt);
51470298 2783 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2784 if (flags & FLAG_VERBOSE)
51470298 2785 c_write_str(ssh, "Failed to authenticate with"
2786 " our public key.\r\n");
32874aea 2787 continue; /* go and try password */
51470298 2788 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2789 bombout(("Bizarre response to RSA authentication response"));
32874aea 2790 crReturn(0);
2791 }
2792
2793 break; /* we're through! */
2794 } else {
51470298 2795 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2796 /*
2797 * Defence against traffic analysis: we send a
2798 * whole bunch of packets containing strings of
2799 * different lengths. One of these strings is the
2800 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2801 * The others are all random data in
2802 * SSH1_MSG_IGNORE packets. This way a passive
2803 * listener can't tell which is the password, and
2804 * hence can't deduce the password length.
2805 *
2806 * Anybody with a password length greater than 16
2807 * bytes is going to have enough entropy in their
2808 * password that a listener won't find it _that_
2809 * much help to know how long it is. So what we'll
2810 * do is:
2811 *
2812 * - if password length < 16, we send 15 packets
2813 * containing string lengths 1 through 15
2814 *
2815 * - otherwise, we let N be the nearest multiple
2816 * of 8 below the password length, and send 8
2817 * packets containing string lengths N through
2818 * N+7. This won't obscure the order of
2819 * magnitude of the password length, but it will
2820 * introduce a bit of extra uncertainty.
2821 *
2822 * A few servers (the old 1.2.18 through 1.2.22)
2823 * can't deal with SSH1_MSG_IGNORE. For these
2824 * servers, we need an alternative defence. We make
2825 * use of the fact that the password is interpreted
2826 * as a C string: so we can append a NUL, then some
2827 * random data.
bd358db1 2828 *
2829 * One server (a Cisco one) can deal with neither
2830 * SSH1_MSG_IGNORE _nor_ a padded password string.
2831 * For this server we are left with no defences
2832 * against password length sniffing.
32874aea 2833 */
51470298 2834 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2835 /*
2836 * The server can deal with SSH1_MSG_IGNORE, so
2837 * we can use the primary defence.
2838 */
32874aea 2839 int bottom, top, pwlen, i;
2840 char *randomstr;
2841
51470298 2842 pwlen = strlen(s->password);
32874aea 2843 if (pwlen < 16) {
2844 bottom = 0; /* zero length passwords are OK! :-) */
2845 top = 15;
2846 } else {
2847 bottom = pwlen & ~7;
2848 top = bottom + 7;
2849 }
2850
2851 assert(pwlen >= bottom && pwlen <= top);
2852
2853 randomstr = smalloc(top + 1);
2854
2855 for (i = bottom; i <= top; i++) {
2856 if (i == pwlen)
51470298 2857 defer_packet(ssh, s->pwpkt_type,
2858 PKT_STR, s->password, PKT_END);
32874aea 2859 else {
2860 for (j = 0; j < i; j++) {
2861 do {
2862 randomstr[j] = random_byte();
2863 } while (randomstr[j] == '\0');
2864 }
2865 randomstr[i] = '\0';
51470298 2866 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 2867 PKT_STR, randomstr, PKT_END);
2868 }
2869 }
bd358db1 2870 logevent("Sending password with camouflage packets");
51470298 2871 ssh_pkt_defersend(ssh);
bd358db1 2872 }
51470298 2873 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2874 /*
2875 * The server can't deal with SSH1_MSG_IGNORE
2876 * but can deal with padded passwords, so we
2877 * can use the secondary defence.
2878 */
bd358db1 2879 char string[64];
51470298 2880 char *ss;
bd358db1 2881 int len;
2882
51470298 2883 len = strlen(s->password);
bd358db1 2884 if (len < sizeof(string)) {
51470298 2885 ss = string;
2886 strcpy(string, s->password);
bd358db1 2887 len++; /* cover the zero byte */
2888 while (len < sizeof(string)) {
2889 string[len++] = (char) random_byte();
2890 }
2891 } else {
51470298 2892 ss = s->password;
bd358db1 2893 }
2894 logevent("Sending length-padded password");
51470298 2895 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2896 PKT_DATA, ss, len, PKT_END);
bd358db1 2897 } else {
2898 /*
2899 * The server has _both_
2900 * BUG_CHOKES_ON_SSH1_IGNORE and
2901 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2902 * therefore nothing we can do.
2903 */
2904 int len;
51470298 2905 len = strlen(s->password);
bd358db1 2906 logevent("Sending unpadded password");
51470298 2907 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2908 PKT_DATA, s->password, len, PKT_END);
32874aea 2909 }
2910 } else {
51470298 2911 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 2912 }
2913 }
c5e9c988 2914 logevent("Sent password");
51470298 2915 memset(s->password, 0, strlen(s->password));
fb09bf1c 2916 crWaitUntil(ispkt);
51470298 2917 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2918 if (flags & FLAG_VERBOSE)
51470298 2919 c_write_str(ssh, "Access denied\r\n");
c5e9c988 2920 logevent("Authentication refused");
51470298 2921 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2922 bombout(("Strange packet received, type %d", ssh->pktin.type));
32874aea 2923 crReturn(0);
374330e2 2924 }
2925 }
2926
c5e9c988 2927 logevent("Authentication successful");
2928
fb09bf1c 2929 crFinish(1);
2930}
2931
32874aea 2932void sshfwd_close(struct ssh_channel *c)
2933{
51470298 2934 Ssh ssh = c->ssh;
2935
80e48603 2936 if (c && !c->closes) {
4ed34d25 2937 /*
2938 * If the channel's remoteid is -1, we have sent
2939 * CHANNEL_OPEN for this channel, but it hasn't even been
2940 * acknowledged by the server. So we must set a close flag
2941 * on it now, and then when the server acks the channel
2942 * open, we can close it then.
2943 */
36cac739 2944 if (((int)c->remoteid) != -1) {
51470298 2945 if (ssh->version == 1) {
2946 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 2947 PKT_END);
2948 } else {
51470298 2949 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2950 ssh2_pkt_adduint32(ssh, c->remoteid);
2951 ssh2_pkt_send(ssh);
4ed34d25 2952 }
32874aea 2953 }
0357890f 2954 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2955 if (c->type == CHAN_X11) {
2956 c->u.x11.s = NULL;
d74d141c 2957 logevent("Forwarded X11 connection terminated");
4ed34d25 2958 } else if (c->type == CHAN_SOCKDATA ||
2959 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2960 c->u.pfd.s = NULL;
2961 logevent("Forwarded port closed");
32874aea 2962 }
2963 }
2964}
2965
5471d09a 2966int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2967{
51470298 2968 Ssh ssh = c->ssh;
2969
2970 if (ssh->version == 1) {
2971 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 2972 PKT_INT, c->remoteid,
2973 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2974 /*
2975 * In SSH1 we can return 0 here - implying that forwarded
2976 * connections are never individually throttled - because
2977 * the only circumstance that can cause throttling will be
2978 * the whole SSH connection backing up, in which case
2979 * _everything_ will be throttled as a whole.
2980 */
2981 return 0;
783415f8 2982 } else {
32874aea 2983 ssh2_add_channel_data(c, buf, len);
5471d09a 2984 return ssh2_try_send(c);
2985 }
2986}
2987
2988void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2989{
51470298 2990 Ssh ssh = c->ssh;
2991
2992 if (ssh->version == 1) {
5471d09a 2993 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2994 c->v.v1.throttling = 0;
51470298 2995 ssh1_throttle(ssh, -1);
5471d09a 2996 }
2997 } else {
2998 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2999 }
9c964e85 3000}
3001
51470298 3002static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3003{
51470298 3004 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3005
3006 random_init();
3007
51470298 3008 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3009 crReturnV;
85ee8208 3010 }
51470298 3011 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3012 crReturnV;
fb09bf1c 3013
979310f1 3014 if (cfg.agentfwd && agent_exists()) {
32874aea 3015 logevent("Requesting agent forwarding");
51470298 3016 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3017 do {
3018 crReturnV;
3019 } while (!ispkt);
51470298 3020 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3021 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3022 bombout(("Protocol confusion"));
3023 crReturnV;
51470298 3024 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3025 logevent("Agent forwarding refused");
3026 } else {
3027 logevent("Agent forwarding enabled");
51470298 3028 ssh->agentfwd_enabled = TRUE;
db7d555c 3029 }
dacbd0e8 3030 }
3031
9c964e85 3032 if (cfg.x11_forward) {
32874aea 3033 char proto[20], data[64];
3034 logevent("Requesting X11 forwarding");
302121de 3035 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3036 data, sizeof(data));
51470298 3037 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3038 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3039 PKT_STR, proto, PKT_STR, data,
3040 PKT_INT, 0, PKT_END);
3041 } else {
51470298 3042 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3043 PKT_STR, proto, PKT_STR, data, PKT_END);
3044 }
3045 do {
3046 crReturnV;
3047 } while (!ispkt);
51470298 3048 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3049 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3050 bombout(("Protocol confusion"));
3051 crReturnV;
51470298 3052 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3053 logevent("X11 forwarding refused");
3054 } else {
3055 logevent("X11 forwarding enabled");
51470298 3056 ssh->X11_fwd_enabled = TRUE;
9c964e85 3057 }
3058 }
3059
d74d141c 3060 {
9bf696b1 3061 char type;
d74d141c 3062 int n;
a4fc0d74 3063 int sport,dport,sserv,dserv;
d74d141c 3064 char sports[256], dports[256], host[256];
3065 char buf[1024];
a4fc0d74 3066 struct servent *se;
d74d141c 3067
51470298 3068 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3069 /* Add port forwardings. */
51470298 3070 ssh->portfwd_strptr = cfg.portfwd;
3071 while (*ssh->portfwd_strptr) {
3072 type = *ssh->portfwd_strptr++;
d74d141c 3073 n = 0;
51470298 3074 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3075 sports[n++] = *ssh->portfwd_strptr++;
d74d141c 3076 sports[n] = 0;
51470298 3077 if (*ssh->portfwd_strptr == '\t')
3078 ssh->portfwd_strptr++;
d74d141c 3079 n = 0;
51470298 3080 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3081 host[n++] = *ssh->portfwd_strptr++;
d74d141c 3082 host[n] = 0;
51470298 3083 if (*ssh->portfwd_strptr == ':')
3084 ssh->portfwd_strptr++;
d74d141c 3085 n = 0;
51470298 3086 while (*ssh->portfwd_strptr)
3087 dports[n++] = *ssh->portfwd_strptr++;
d74d141c 3088 dports[n] = 0;
51470298 3089 ssh->portfwd_strptr++;
d74d141c 3090 dport = atoi(dports);
a4fc0d74 3091 dserv = 0;
3092 if (dport == 0) {
3093 dserv = 1;
3094 se = getservbyname(dports, NULL);
3095 if (se != NULL) {
3096 dport = ntohs(se->s_port);
3097 } else {
3098 sprintf(buf,
3099 "Service lookup failed for destination port \"%s\"",
3100 dports);
3101 logevent(buf);
3102 }
3103 }
d74d141c 3104 sport = atoi(sports);
a4fc0d74 3105 sserv = 0;
3106 if (sport == 0) {
3107 sserv = 1;
3108 se = getservbyname(sports, NULL);
3109 if (se != NULL) {
3110 sport = ntohs(se->s_port);
3111 } else {
3112 sprintf(buf,
3113 "Service lookup failed for source port \"%s\"",
3114 sports);
3115 logevent(buf);
3116 }
3117 }
d74d141c 3118 if (sport && dport) {
3119 if (type == 'L') {
6b78788a 3120 pfd_addforward(host, dport, sport, ssh);
a4fc0d74 3121 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3122 " %s:%.*s%.*s%d%.*s",
3123 sserv ? strlen(sports) : 0, sports,
3124 sserv, "(", sport, sserv, ")",
3125 host,
3126 dserv ? strlen(dports) : 0, dports,
3127 dserv, "(", dport, dserv, ")");
d74d141c 3128 logevent(buf);
3129 } else {
3130 struct ssh_rportfwd *pf;
3131 pf = smalloc(sizeof(*pf));
bc240b21 3132 strcpy(pf->dhost, host);
3133 pf->dport = dport;
51470298 3134 if (add234(ssh->rportfwds, pf) != pf) {
d74d141c 3135 sprintf(buf,
95bc8819 3136 "Duplicate remote port forwarding to %s:%d",
d74d141c 3137 host, dport);
3138 logevent(buf);
bc240b21 3139 sfree(pf);
d74d141c 3140 } else {
a4fc0d74 3141 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3142 " forward to %s:%.*s%.*s%d%.*s",
3143 sserv ? strlen(sports) : 0, sports,
3144 sserv, "(", sport, sserv, ")",
3145 host,
3146 dserv ? strlen(dports) : 0, dports,
3147 dserv, "(", dport, dserv, ")");
d74d141c 3148 logevent(buf);
51470298 3149 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3150 PKT_INT, sport,
3151 PKT_STR, host,
3152 PKT_INT, dport,
3153 PKT_END);
9bf696b1 3154 do {
3155 crReturnV;
3156 } while (!ispkt);
51470298 3157 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3158 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
9bf696b1 3159 bombout(("Protocol confusion"));
3160 crReturnV;
51470298 3161 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3162 c_write_str(ssh, "Server refused port"
3163 " forwarding\r\n");
9bf696b1 3164 }
3165 logevent("Remote port forwarding enabled");
d74d141c 3166 }
3167 }
3168 }
3169 }
3170 }
3171
fef97f43 3172 if (!cfg.nopty) {
51470298 3173 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
32874aea 3174 PKT_STR, cfg.termtype,
51470298 3175 PKT_INT, ssh->term_height,
3176 PKT_INT, ssh->term_width,
32874aea 3177 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3178 ssh->state = SSH_STATE_INTERMED;
32874aea 3179 do {
3180 crReturnV;
3181 } while (!ispkt);
51470298 3182 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3183 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3184 bombout(("Protocol confusion"));
3185 crReturnV;
51470298 3186 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3187 c_write_str(ssh, "Server refused to allocate pty\r\n");
3188 ssh->editing = ssh->echoing = 1;
32874aea 3189 }
c5e9c988 3190 logevent("Allocated pty");
0965bee0 3191 } else {
51470298 3192 ssh->editing = ssh->echoing = 1;
374330e2 3193 }
3194
4ba9b64b 3195 if (cfg.compression) {
51470298 3196 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3197 do {
3198 crReturnV;
3199 } while (!ispkt);
51470298 3200 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3201 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3202 bombout(("Protocol confusion"));
3203 crReturnV;
51470298 3204 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3205 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3206 }
4ba9b64b 3207 logevent("Started compression");
51470298 3208 ssh->v1_compressing = TRUE;
5366aed8 3209 ssh->cs_comp_ctx = zlib_compress_init();
3210 logevent("Initialised zlib (RFC1950) compression");
3211 ssh->sc_comp_ctx = zlib_decompress_init();
3212 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3213 }
3214
fd5e5847 3215 /*
3216 * Start the shell or command.
3217 *
3218 * Special case: if the first-choice command is an SSH2
3219 * subsystem (hence not usable here) and the second choice
3220 * exists, we fall straight back to that.
3221 */
3222 {
3223 char *cmd = cfg.remote_cmd_ptr;
3224
3225 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3226 cmd = cfg.remote_cmd_ptr2;
51470298 3227 ssh->fallback_cmd = TRUE;
fd5e5847 3228 }
3229 if (*cmd)
51470298 3230 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3231 else
51470298 3232 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3233 logevent("Started session");
3234 }
374330e2 3235
51470298 3236 ssh->state = SSH_STATE_SESSION;
3237 if (ssh->size_needed)
3238 ssh_size(ssh, ssh->term_width, ssh->term_height);
3239 if (ssh->eof_needed)
3240 ssh_special(ssh, TS_EOF);
374330e2 3241
b9d7bcad 3242 if (ssh->ldisc)
3243 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3244 ssh->send_ok = 1;
3245 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3246 while (1) {
3247 crReturnV;
3248 if (ispkt) {
51470298 3249 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3250 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3251 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3252 int bufsize =
51470298 3253 from_backend(ssh->frontend,
3254 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3255 ssh->pktin.body + 4, len);
3256 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3257 ssh->v1_stdout_throttling = 1;
3258 ssh1_throttle(ssh, +1);
5471d09a 3259 }
51470298 3260 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3261 ssh->state = SSH_STATE_CLOSED;
c5e9c988 3262 logevent("Received disconnect request");
32874aea 3263 crReturnV;
51470298 3264 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3265 /* Remote side is trying to open a channel to talk to our
3266 * X-Server. Give them back a local channel number. */
3267 struct ssh_channel *c;
9c964e85 3268
3269 logevent("Received X11 connect request");
3270 /* Refuse if X11 forwarding is disabled. */
51470298 3271 if (!ssh->X11_fwd_enabled) {
3272 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3273 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3274 logevent("Rejected X11 connect request");
3275 } else {
9c964e85 3276 c = smalloc(sizeof(struct ssh_channel));
51470298 3277 c->ssh = ssh;
9c964e85 3278
302121de 3279 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3280 ssh->x11auth) != NULL) {
32874aea 3281 logevent("opening X11 forward connection failed");
3282 sfree(c);
51470298 3283 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3284 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3285 PKT_END);
9c964e85 3286 } else {
32874aea 3287 logevent
3288 ("opening X11 forward connection succeeded");
51470298 3289 c->remoteid = GET_32BIT(ssh->pktin.body);
3290 c->localid = alloc_channel_id(ssh);
32874aea 3291 c->closes = 0;
5471d09a 3292 c->v.v1.throttling = 0;
32874aea 3293 c->type = CHAN_X11; /* identify channel type */
51470298 3294 add234(ssh->channels, c);
3295 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3296 PKT_INT, c->remoteid, PKT_INT,
3297 c->localid, PKT_END);
3298 logevent("Opened X11 forward channel");
9c964e85 3299 }
3300 }
51470298 3301 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3302 /* Remote side is trying to open a channel to talk to our
3303 * agent. Give them back a local channel number. */
3304 struct ssh_channel *c;
db7d555c 3305
3306 /* Refuse if agent forwarding is disabled. */
51470298 3307 if (!ssh->agentfwd_enabled) {
3308 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3309 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3310 } else {
dcbde236 3311 c = smalloc(sizeof(struct ssh_channel));
51470298 3312 c->ssh = ssh;
3313 c->remoteid = GET_32BIT(ssh->pktin.body);
3314 c->localid = alloc_channel_id(ssh);
db7d555c 3315 c->closes = 0;
5471d09a 3316 c->v.v1.throttling = 0;
32874aea 3317 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3318 c->u.a.lensofar = 0;
51470298 3319 add234(ssh->channels, c);
3320 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3321 PKT_INT, c->remoteid, PKT_INT, c->localid,
3322 PKT_END);
3323 }
51470298 3324 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3325 /* Remote side is trying to open a channel to talk to a
3326 * forwarded port. Give them back a local channel number. */
3327 struct ssh_channel *c;
3328 struct ssh_rportfwd pf;
3329 int hostsize, port;
3330 char host[256], buf[1024];
3331 char *p, *h, *e;
3332 c = smalloc(sizeof(struct ssh_channel));
51470298 3333 c->ssh = ssh;
d74d141c 3334
51470298 3335 hostsize = GET_32BIT(ssh->pktin.body+4);
3336 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
d74d141c 3337 if (h+1 < host+sizeof(host))
3338 *h++ = *p;
95bc8819 3339 p++;
d74d141c 3340 }
3341 *h = 0;
3342 port = GET_32BIT(p);
3343
bc240b21 3344 strcpy(pf.dhost, host);
3345 pf.dport = port;
d74d141c 3346
51470298 3347 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3348 sprintf(buf, "Rejected remote port open request for %s:%d",
3349 host, port);
3350 logevent(buf);
51470298 3351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3352 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3353 } else {
3354 sprintf(buf, "Received remote port open request for %s:%d",
3355 host, port);
3356 logevent(buf);
3357 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3358 if (e != NULL) {
3359 char buf[256];
3360 sprintf(buf, "Port open failed: %s", e);
3361 logevent(buf);
3362 sfree(c);
51470298 3363 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3364 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3365 PKT_END);
3366 } else {
51470298 3367 c->remoteid = GET_32BIT(ssh->pktin.body);
3368 c->localid = alloc_channel_id(ssh);
d74d141c 3369 c->closes = 0;
5471d09a 3370 c->v.v1.throttling = 0;
d74d141c 3371 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3372 add234(ssh->channels, c);
3373 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3374 PKT_INT, c->remoteid, PKT_INT,
3375 c->localid, PKT_END);
3376 logevent("Forwarded port opened successfully");
3377 }
3378 }
3379
51470298 3380 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3381 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3382 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3383 struct ssh_channel *c;
3384
51470298 3385 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3386 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3387 c->remoteid = localid;
3388 c->type = CHAN_SOCKDATA;
7781f316 3389 c->v.v1.throttling = 0;
bc240b21 3390 pfd_confirm(c->u.pfd.s);
3391 }
d74d141c 3392
4ed34d25 3393 if (c && c->closes) {
3394 /*
3395 * We have a pending close on this channel,
3396 * which we decided on before the server acked
3397 * the channel open. So now we know the
3398 * remoteid, we can close it again.
3399 */
51470298 3400 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3401 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3402 }
3403
51470298 3404 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3405 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3406 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
724cface 3407 struct ssh_channel *c;
3408
51470298 3409 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3410 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3411 logevent("Forwarded connection refused by server");
3412 pfd_close(c->u.pfd.s);
51470298 3413 del234(ssh->channels, c);
724cface 3414 sfree(c);
3415 }
3416
51470298 3417 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3418 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3419 /* Remote side closes a channel. */
51470298 3420 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3421 struct ssh_channel *c;
51470298 3422 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3423 if (c && ((int)c->remoteid) != -1) {
32874aea 3424 int closetype;
3425 closetype =
51470298 3426 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3427
783415f8 3428 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3429 logevent("Forwarded X11 connection terminated");
9c964e85 3430 assert(c->u.x11.s != NULL);
3431 x11_close(c->u.x11.s);
3432 c->u.x11.s = NULL;
3433 }
d74d141c 3434 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3435 logevent("Forwarded port closed");
3436 assert(c->u.pfd.s != NULL);
3437 pfd_close(c->u.pfd.s);
3438 c->u.pfd.s = NULL;
3439 }
0357890f 3440
3441 c->closes |= (closetype << 2); /* seen this message */
3442 if (!(c->closes & closetype)) {
51470298 3443 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3444 PKT_END);
3445 c->closes |= closetype; /* sent it too */
3446 }
3447
3448 if (c->closes == 15) {
51470298 3449 del234(ssh->channels, c);
32874aea 3450 sfree(c);
3451 }
d0d844c1 3452 } else {
3453 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3454 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3455 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3456 i));
32874aea 3457 }
51470298 3458 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3459 /* Data sent down one of our channels. */
51470298 3460 int i = GET_32BIT(ssh->pktin.body);
3461 int len = GET_32BIT(ssh->pktin.body + 4);
3462 unsigned char *p = ssh->pktin.body + 8;
32874aea 3463 struct ssh_channel *c;
51470298 3464 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3465 if (c) {
5471d09a 3466 int bufsize;
32874aea 3467 switch (c->type) {
3468 case CHAN_X11:
5471d09a 3469 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3470 break;
d74d141c 3471 case CHAN_SOCKDATA:
5471d09a 3472 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3473 break;
32874aea 3474 case CHAN_AGENT:
3475 /* Data for an agent message. Buffer it. */
3476 while (len > 0) {
3477 if (c->u.a.lensofar < 4) {
3478 int l = min(4 - c->u.a.lensofar, len);
3479 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3480 l);
3481 p += l;
3482 len -= l;
3483 c->u.a.lensofar += l;
3484 }
3485 if (c->u.a.lensofar == 4) {
3486 c->u.a.totallen =
3487 4 + GET_32BIT(c->u.a.msglen);
3488 c->u.a.message = smalloc(c->u.a.totallen);
3489 memcpy(c->u.a.message, c->u.a.msglen, 4);
3490 }
3491 if (c->u.a.lensofar >= 4 && len > 0) {
3492 int l =
3493 min(c->u.a.totallen - c->u.a.lensofar,
3494 len);
3495 memcpy(c->u.a.message + c->u.a.lensofar, p,
3496 l);
3497 p += l;
3498 len -= l;
3499 c->u.a.lensofar += l;
3500 }
3501 if (c->u.a.lensofar == c->u.a.totallen) {
3502 void *reply, *sentreply;
3503 int replylen;
3504 agent_query(c->u.a.message,
3505 c->u.a.totallen, &reply,
3506 &replylen);
3507 if (reply)
3508 sentreply = reply;
3509 else {
3510 /* Fake SSH_AGENT_FAILURE. */
3511 sentreply = "\0\0\0\1\5";
3512 replylen = 5;
3513 }
51470298 3514 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3515 PKT_INT, c->remoteid,
3516 PKT_INT, replylen,
3517 PKT_DATA, sentreply, replylen,
3518 PKT_END);
3519 if (reply)
3520 sfree(reply);
3521 sfree(c->u.a.message);
3522 c->u.a.lensofar = 0;
3523 }
3524 }
5471d09a 3525 bufsize = 0; /* agent channels never back up */
32874aea 3526 break;
3527 }
90347b95 3528 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3529 c->v.v1.throttling = 1;
51470298 3530 ssh1_throttle(ssh, +1);
5471d09a 3531 }
32874aea 3532 }
51470298 3533 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3534 /* may be from EXEC_SHELL on some servers */
51470298 3535 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3536 /* may be from EXEC_SHELL on some servers
374330e2 3537 * if no pty is available or in other odd cases. Ignore */
51470298 3538 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3539 char buf[100];
51470298 3540 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3541 sprintf(buf, "Server sent command exit status %d",
51470298 3542 ssh->exitcode);
d8d6c7e5 3543 logevent(buf);
51470298 3544 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3545 /*
3546 * In case `helpful' firewalls or proxies tack
3547 * extra human-readable text on the end of the
3548 * session which we might mistake for another
3549 * encrypted packet, we close the session once
3550 * we've sent EXIT_CONFIRMATION.
3551 */
51470298 3552 ssh->state = SSH_STATE_CLOSED;
4252c9cc 3553 crReturnV;
374330e2 3554 } else {
51470298 3555 bombout(("Strange packet received: type %d", ssh->pktin.type));
32874aea 3556 crReturnV;
374330e2 3557 }
3558 } else {
8df7a775 3559 while (inlen > 0) {
3560 int len = min(inlen, 512);
51470298 3561 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3562 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3563 in += len;
3564 inlen -= len;
3565 }
374330e2 3566 }
3567 }
3568
3569 crFinishV;
3570}
3571
3572/*
e5574168 3573 * Utility routine for decoding comma-separated strings in KEXINIT.
3574 */
32874aea 3575static int in_commasep_string(char *needle, char *haystack, int haylen)
3576{
e5574168 3577 int needlen = strlen(needle);
3578 while (1) {
32874aea 3579 /*
3580 * Is it at the start of the string?
3581 */
3582 if (haylen >= needlen && /* haystack is long enough */
3583 !memcmp(needle, haystack, needlen) && /* initial match */
3584 (haylen == needlen || haystack[needlen] == ',')
3585 /* either , or EOS follows */
3586 )
3587 return 1;
3588 /*
3589 * If not, search for the next comma and resume after that.
3590 * If no comma found, terminate.
3591 */
3592 while (haylen > 0 && *haystack != ',')
3593 haylen--, haystack++;
3594 if (haylen == 0)
3595 return 0;
3596 haylen--, haystack++; /* skip over comma itself */
e5574168 3597 }
3598}
3599
3600/*
d39f364a 3601 * SSH2 key creation method.
3602 */
51470298 3603static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
32874aea 3604 char *keyspace)
3605{
d39f364a 3606 SHA_State s;
3607 /* First 20 bytes. */
3608 SHA_Init(&s);
51470298 3609 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3610 sha_mpint(&s, K);
d39f364a 3611 SHA_Bytes(&s, H, 20);
3612 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3613 SHA_Bytes(&s, sessid, 20);
d39f364a 3614 SHA_Final(&s, keyspace);
3615 /* Next 20 bytes. */
3616 SHA_Init(&s);
51470298 3617 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3618 sha_mpint(&s, K);
d39f364a 3619 SHA_Bytes(&s, H, 20);
3620 SHA_Bytes(&s, keyspace, 20);
32874aea 3621 SHA_Final(&s, keyspace + 20);
d39f364a 3622}
3623
3624/*
7cca0d81 3625 * Handle the SSH2 transport layer.
e5574168 3626 */
51470298 3627static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3628{
51470298 3629 struct do_ssh2_transport_state {
3630 int nbits, pbits, warn;
3631 Bignum p, g, e, f, K;
3632 int kex_init_value, kex_reply_value;
3633 const struct ssh_mac **maclist;
3634 int nmacs;
3635 const struct ssh2_cipher *cscipher_tobe;
3636 const struct ssh2_cipher *sccipher_tobe;
3637 const struct ssh_mac *csmac_tobe;
3638 const struct ssh_mac *scmac_tobe;
3639 const struct ssh_compress *cscomp_tobe;
3640 const struct ssh_compress *sccomp_tobe;
3641 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3642 int hostkeylen, siglen;
3643 void *hkey; /* actual host key */
3644 unsigned char exchange_hash[20];
3645 int n_preferred_ciphers;
3646 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3647 const struct ssh_compress *preferred_comp;
3648 int first_kex;
3649 };
3650 crState(do_ssh2_transport_state);
3651
3652 crBegin(ssh->do_ssh2_transport_crstate);
3653
3654 s->cscipher_tobe = s->sccipher_tobe = NULL;
3655 s->csmac_tobe = s->scmac_tobe = NULL;
3656 s->cscomp_tobe = s->sccomp_tobe = NULL;
3657
7cca0d81 3658 random_init();
51470298 3659 s->first_kex = 1;
e5574168 3660
51470298 3661 {
3662 int i;
3663 /*
3664 * Set up the preferred ciphers. (NULL => warn below here)
3665 */
3666 s->n_preferred_ciphers = 0;
3667 for (i = 0; i < CIPHER_MAX; i++) {
3668 switch (cfg.ssh_cipherlist[i]) {
3669 case CIPHER_BLOWFISH:
3670 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3671 break;
3672 case CIPHER_DES:
3673 if (cfg.ssh2_des_cbc) {
3674 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3675 }
3676 break;
3677 case CIPHER_3DES:
3678 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3679 break;
3680 case CIPHER_AES:
3681 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3682 break;
3683 case CIPHER_WARN:
3684 /* Flag for later. Don't bother if it's the last in
3685 * the list. */
3686 if (i < CIPHER_MAX - 1) {
3687 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3688 }
3689 break;
ca20bfcf 3690 }
ca20bfcf 3691 }
5e8358ad 3692 }
ca20bfcf 3693
3694 /*
3695 * Set up preferred compression.
3696 */
4ba9b64b 3697 if (cfg.compression)
51470298 3698 s->preferred_comp = &ssh_zlib;
4ba9b64b 3699 else
51470298 3700 s->preferred_comp = &ssh_comp_none;
5e8358ad 3701
7591b9ff 3702 /*
3703 * Be prepared to work around the buggy MAC problem.
3704 */
51470298 3705 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3706 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3707 else
51470298 3708 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3709
32874aea 3710 begin_key_exchange:
51470298 3711 {
3712 int i, j, cipherstr_started;
3713
3714 /*
3715 * Construct and send our key exchange packet.
3716 */
3717 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3718 for (i = 0; i < 16; i++)
3719 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3720 /* List key exchange algorithms. */
3721 ssh2_pkt_addstring_start(ssh);
3722 for (i = 0; i < lenof(kex_algs); i++) {
3723 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3724 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3725 continue;
3726 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3727 if (i < lenof(kex_algs) - 1)
3728 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3729 }
51470298 3730 /* List server host key algorithms. */
3731 ssh2_pkt_addstring_start(ssh);
3732 for (i = 0; i < lenof(hostkey_algs); i++) {
3733 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3734 if (i < lenof(hostkey_algs) - 1)
3735 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3736 }
51470298 3737 /* List client->server encryption algorithms. */
3738 ssh2_pkt_addstring_start(ssh);
3739 cipherstr_started = 0;
3740 for (i = 0; i < s->n_preferred_ciphers; i++) {
3741 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3742 if (!c) continue; /* warning flag */
3743 for (j = 0; j < c->nciphers; j++) {
3744 if (cipherstr_started)
3745 ssh2_pkt_addstring_str(ssh, ",");
3746 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3747 cipherstr_started = 1;
3748 }
3749 }
3750 /* List server->client encryption algorithms. */
3751 ssh2_pkt_addstring_start(ssh);
3752 cipherstr_started = 0;
3753 for (i = 0; i < s->n_preferred_ciphers; i++) {
3754 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3755 if (!c) continue; /* warning flag */
3756 for (j = 0; j < c->nciphers; j++) {
3757 if (cipherstr_started)
3758 ssh2_pkt_addstring_str(ssh, ",");
3759 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3760 cipherstr_started = 1;
3761 }
3762 }
3763 /* List client->server MAC algorithms. */
3764 ssh2_pkt_addstring_start(ssh);
3765 for (i = 0; i < s->nmacs; i++) {
3766 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3767 if (i < s->nmacs - 1)
3768 ssh2_pkt_addstring_str(ssh, ",");
3769 }
3770 /* List server->client MAC algorithms. */
3771 ssh2_pkt_addstring_start(ssh);
3772 for (i = 0; i < s->nmacs; i++) {
3773 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3774 if (i < s->nmacs - 1)
3775 ssh2_pkt_addstring_str(ssh, ",");
3776 }
3777 /* List client->server compression algorithms. */
3778 ssh2_pkt_addstring_start(ssh);
3779 for (i = 0; i < lenof(compressions) + 1; i++) {
3780 const struct ssh_compress *c =
3781 i == 0 ? s->preferred_comp : compressions[i - 1];
3782 ssh2_pkt_addstring_str(ssh, c->name);
3783 if (i < lenof(compressions))
3784 ssh2_pkt_addstring_str(ssh, ",");
3785 }
3786 /* List server->client compression algorithms. */
3787 ssh2_pkt_addstring_start(ssh);
3788 for (i = 0; i < lenof(compressions) + 1; i++) {
3789 const struct ssh_compress *c =
3790 i == 0 ? s->preferred_comp : compressions[i - 1];
3791 ssh2_pkt_addstring_str(ssh, c->name);
3792 if (i < lenof(compressions))
3793 ssh2_pkt_addstring_str(ssh, ",");
3794 }
3795 /* List client->server languages. Empty list. */
3796 ssh2_pkt_addstring_start(ssh);
3797 /* List server->client languages. Empty list. */
3798 ssh2_pkt_addstring_start(ssh);
3799 /* First KEX packet does _not_ follow, because we're not that brave. */
3800 ssh2_pkt_addbool(ssh, FALSE);
3801 /* Reserved. */
3802 ssh2_pkt_adduint32(ssh, 0);
e5574168 3803 }
0db56f73 3804
51470298 3805 ssh->exhash = ssh->exhashbase;
3806 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 3807
51470298 3808 ssh2_pkt_send(ssh);
e5574168 3809
32874aea 3810 if (!ispkt)
3811 crWaitUntil(ispkt);
51470298 3812 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 3813
3814 /*
3815 * Now examine the other side's KEXINIT to see what we're up
3816 * to.
3817 */
51470298 3818 {
3819 char *str;
3820 int i, j, len;
3821
3822 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3823 bombout(("expected key exchange packet from server"));
3824 crReturn(0);
32874aea 3825 }
51470298 3826 ssh->kex = NULL;
3827 ssh->hostkey = NULL;
3828 s->cscipher_tobe = NULL;
3829 s->sccipher_tobe = NULL;
3830 s->csmac_tobe = NULL;
3831 s->scmac_tobe = NULL;
3832 s->cscomp_tobe = NULL;
3833 s->sccomp_tobe = NULL;
3834 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3835 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3836 for (i = 0; i < lenof(kex_algs); i++) {
3837 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3838 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3839 continue;
3840 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3841 ssh->kex = kex_algs[i];
3842 break;
3843 }
32874aea 3844 }
51470298 3845 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3846 for (i = 0; i < lenof(hostkey_algs); i++) {
3847 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3848 ssh->hostkey = hostkey_algs[i];
3849 break;
3850 }
3851 }
3852 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3853 s->warn = 0;
3854 for (i = 0; i < s->n_preferred_ciphers; i++) {
3855 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3856 if (!c) {
3857 s->warn = 1;
3858 } else {
3859 for (j = 0; j < c->nciphers; j++) {
3860 if (in_commasep_string(c->list[j]->name, str, len)) {
3861 s->cscipher_tobe = c->list[j];
3862 break;
3863 }
ca20bfcf 3864 }
32874aea 3865 }
51470298 3866 if (s->cscipher_tobe) {
3867 if (s->warn)
3868 askcipher(s->cscipher_tobe->name, 1);
3869 break;
3870 }
32874aea 3871 }
51470298 3872 if (!s->cscipher_tobe) {
3873 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3874 crReturn(0);
ca20bfcf 3875 }
0ef8f407 3876
51470298 3877 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3878 s->warn = 0;
3879 for (i = 0; i < s->n_preferred_ciphers; i++) {
3880 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3881 if (!c) {
3882 s->warn = 1;
3883 } else {
3884 for (j = 0; j < c->nciphers; j++) {
3885 if (in_commasep_string(c->list[j]->name, str, len)) {
3886 s->sccipher_tobe = c->list[j];
3887 break;
3888 }
ca20bfcf 3889 }
32874aea 3890 }
51470298 3891 if (s->sccipher_tobe) {
3892 if (s->warn)
3893 askcipher(s->sccipher_tobe->name, 2);
3894 break;
3895 }
32874aea 3896 }
51470298 3897 if (!s->sccipher_tobe) {
3898 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3899 crReturn(0);
ca20bfcf 3900 }
0ef8f407 3901
51470298 3902 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3903 for (i = 0; i < s->nmacs; i++) {
3904 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3905 s->csmac_tobe = s->maclist[i];
3906 break;
3907 }
32874aea 3908 }
51470298 3909 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3910 for (i = 0; i < s->nmacs; i++) {
3911 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3912 s->scmac_tobe = s->maclist[i];
3913 break;
3914 }
32874aea 3915 }
51470298 3916 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3917 for (i = 0; i < lenof(compressions) + 1; i++) {
3918 const struct ssh_compress *c =
3919 i == 0 ? s->preferred_comp : compressions[i - 1];
3920 if (in_commasep_string(c->name, str, len)) {
3921 s->cscomp_tobe = c;
3922 break;
3923 }
32874aea 3924 }
51470298 3925 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3926 for (i = 0; i < lenof(compressions) + 1; i++) {
3927 const struct ssh_compress *c =
3928 i == 0 ? s->preferred_comp : compressions[i - 1];
3929 if (in_commasep_string(c->name, str, len)) {
3930 s->sccomp_tobe = c;
3931 break;
3932 }
32874aea 3933 }
e5574168 3934 }
e5574168 3935
3936 /*
7bd5a860 3937 * Work out the number of bits of key we will need from the key
3938 * exchange. We start with the maximum key length of either
3939 * cipher...
3940 */
3941 {
32874aea 3942 int csbits, scbits;
7bd5a860 3943
51470298 3944 csbits = s->cscipher_tobe->keylen;
3945 scbits = s->sccipher_tobe->keylen;
3946 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 3947 }
3948 /* The keys only have 160-bit entropy, since they're based on
3949 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 3950 if (s->nbits > 160)
3951 s->nbits = 160;
7bd5a860 3952
3953 /*
a92dd380 3954 * If we're doing Diffie-Hellman group exchange, start by
3955 * requesting a group.
e5574168 3956 */
51470298 3957 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 3958 logevent("Doing Diffie-Hellman group exchange");
51470298 3959 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3960 /*
3961 * Work out how big a DH group we will need to allow that
3962 * much data.
7bd5a860 3963 */
51470298 3964 s->pbits = 512 << ((s->nbits - 1) / 64);
3965 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3966 ssh2_pkt_adduint32(ssh, s->pbits);
3967 ssh2_pkt_send(ssh);
32874aea 3968
3969 crWaitUntil(ispkt);
51470298 3970 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
32874aea 3971 bombout(("expected key exchange group packet from server"));
3972 crReturn(0);
3973 }
51470298 3974 s->p = ssh2_pkt_getmp(ssh);
3975 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 3976 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 3977 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3978 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3979 } else {
51470298 3980 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 3981 ssh->kex_ctx = dh_setup_group1();
51470298 3982 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3983 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3984 }
e5574168 3985
a92dd380 3986 logevent("Doing Diffie-Hellman key exchange");
e5574168 3987 /*
a92dd380 3988 * Now generate and send e for Diffie-Hellman.
e5574168 3989 */
27cd7fc2 3990 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 3991 ssh2_pkt_init(ssh, s->kex_init_value);
3992 ssh2_pkt_addmp(ssh, s->e);
3993 ssh2_pkt_send(ssh);
e5574168 3994
3995 crWaitUntil(ispkt);
51470298 3996 if (ssh->pktin.type != s->kex_reply_value) {
32874aea 3997 bombout(("expected key exchange reply packet from server"));
3998 crReturn(0);
7cca0d81 3999 }
51470298 4000 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4001 s->f = ssh2_pkt_getmp(ssh);
4002 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4003
27cd7fc2 4004 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4005
51470298 4006 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4007 if (ssh->kex == &ssh_diffiehellman_gex) {
4008 sha_uint32(&ssh->exhash, s->pbits);
4009 sha_mpint(&ssh->exhash, s->p);
4010 sha_mpint(&ssh->exhash, s->g);
a92dd380 4011 }
51470298 4012 sha_mpint(&ssh->exhash, s->e);
4013 sha_mpint(&ssh->exhash, s->f);
4014 sha_mpint(&ssh->exhash, s->K);
4015 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4016
27cd7fc2 4017 dh_cleanup(ssh->kex_ctx);
3709bfe9 4018
7cca0d81 4019#if 0
765c4200 4020 debug(("Exchange hash is:\n"));
51470298 4021 dmemdump(s->exchange_hash, 20);
7cca0d81 4022#endif
4023
51470298 4024 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4025 if (!s->hkey ||
4026 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4027 s->exchange_hash, 20)) {
f7259d10 4028 bombout(("Server's host key did not match the signature supplied"));
32874aea 4029 crReturn(0);
8d5de777 4030 }
e5574168 4031
4032 /*
7cca0d81 4033 * Authenticate remote host: verify host key. (We've already
4034 * checked the signature of the exchange hash.)
e5574168 4035 */
51470298 4036 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4037 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4038 verify_ssh_host_key(ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4039 s->keystr, s->fingerprint);
4040 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4041 logevent("Host key fingerprint is:");
51470298 4042 logevent(s->fingerprint);
5e0d7cb8 4043 }
51470298 4044 sfree(s->fingerprint);
4045 sfree(s->keystr);
4046 ssh->hostkey->freekey(s->hkey);
d39f364a 4047
4048 /*
7cca0d81 4049 * Send SSH2_MSG_NEWKEYS.
d39f364a 4050 */
51470298 4051 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4052 ssh2_pkt_send(ssh);
d39f364a 4053
4054 /*
8406eaf9 4055 * Expect SSH2_MSG_NEWKEYS from server.
4056 */
4057 crWaitUntil(ispkt);
51470298 4058 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
8406eaf9 4059 bombout(("expected new-keys packet from server"));
4060 crReturn(0);
4061 }
4062
4063 /*
d39f364a 4064 * Create and initialise session keys.
4065 */
371e569c 4066 if (ssh->cs_cipher_ctx)
4067 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4068 ssh->cscipher = s->cscipher_tobe;
371e569c 4069 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4070
371e569c 4071 if (ssh->sc_cipher_ctx)
4072 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4073 ssh->sccipher = s->sccipher_tobe;
371e569c 4074 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4075
4076 if (ssh->cs_mac_ctx)
4077 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4078 ssh->csmac = s->csmac_tobe;
e0e1a00d 4079 ssh->cs_mac_ctx = ssh->csmac->make_context();
4080
4081 if (ssh->sc_mac_ctx)
4082 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4083 ssh->scmac = s->scmac_tobe;
e0e1a00d 4084 ssh->sc_mac_ctx = ssh->scmac->make_context();
4085
5366aed8 4086 if (ssh->cs_comp_ctx)
4087 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4088 ssh->cscomp = s->cscomp_tobe;
5366aed8 4089 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4090
4091 if (ssh->sc_comp_ctx)
4092 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4093 ssh->sccomp = s->sccomp_tobe;
5366aed8 4094 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4095
d39f364a 4096 /*
5e0d7cb8 4097 * Set IVs after keys. Here we use the exchange hash from the
4098 * _first_ key exchange.
d39f364a 4099 */
51470298 4100 {
4101 unsigned char keyspace[40];
4102 if (s->first_kex)
4103 memcpy(ssh->v2_session_id, s->exchange_hash,
4104 sizeof(s->exchange_hash));
4105 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4106 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4107 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4108 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4109 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4110 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4111 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4112 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4113 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4114 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4115 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4116 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4117 }
371e569c 4118 {
4119 char buf[256];
4120 sprintf(buf, "Initialised %.200s client->server encryption",
4121 ssh->cscipher->text_name);
4122 logevent(buf);
4123 sprintf(buf, "Initialised %.200s server->client encryption",
4124 ssh->sccipher->text_name);
4125 logevent(buf);
5366aed8 4126 if (ssh->cscomp->text_name) {
4127 sprintf(buf, "Initialised %.200s compression",
4128 ssh->cscomp->text_name);
4129 logevent(buf);
4130 }
4131 if (ssh->sccomp->text_name) {
4132 sprintf(buf, "Initialised %.200s decompression",
4133 ssh->sccomp->text_name);
4134 logevent(buf);
4135 }
371e569c 4136 }
4137
d39f364a 4138
033b4cef 4139 /*
0db56f73 4140 * If this is the first key exchange phase, we must pass the
4141 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4142 * wants to see it but because it will need time to initialise
4143 * itself before it sees an actual packet. In subsequent key
4144 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4145 * it would only confuse the layer above.
4146 */
51470298 4147 if (!s->first_kex) {
32874aea 4148 crReturn(0);
0db56f73 4149 }
51470298 4150 s->first_kex = 0;
0db56f73 4151
4152 /*
7cca0d81 4153 * Now we're encrypting. Begin returning 1 to the protocol main
4154 * function so that other things can run on top of the
4155 * transport. If we ever see a KEXINIT, we must go back to the
4156 * start.
033b4cef 4157 */
51470298 4158 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4159 crReturn(1);
e96adf72 4160 }
5e0d7cb8 4161 logevent("Server initiated key re-exchange");
7cca0d81 4162 goto begin_key_exchange;
e5574168 4163
4164 crFinish(1);
4165}
4166
7cca0d81 4167/*
783415f8 4168 * Add data to an SSH2 channel output buffer.
4169 */
32874aea 4170static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4171 int len)
4172{
5471d09a 4173 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4174}
4175
4176/*
4177 * Attempt to send data on an SSH2 channel.
4178 */
5471d09a 4179static int ssh2_try_send(struct ssh_channel *c)
32874aea 4180{
51470298 4181 Ssh ssh = c->ssh;
4182
5471d09a 4183 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4184 int len;
4185 void *data;
4186 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4187 if ((unsigned)len > c->v.v2.remwindow)
4188 len = c->v.v2.remwindow;
4189 if ((unsigned)len > c->v.v2.remmaxpkt)
4190 len = c->v.v2.remmaxpkt;
51470298 4191 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4192 ssh2_pkt_adduint32(ssh, c->remoteid);
4193 ssh2_pkt_addstring_start(ssh);
4194 ssh2_pkt_addstring_data(ssh, data, len);
4195 ssh2_pkt_send(ssh);
5471d09a 4196 bufchain_consume(&c->v.v2.outbuffer, len);
4197 c->v.v2.remwindow -= len;
4198 }
4199
4200 /*
4201 * After having sent as much data as we can, return the amount
4202 * still buffered.
4203 */
4204 return bufchain_size(&c->v.v2.outbuffer);
4205}
4206
4207/*
4208 * Potentially enlarge the window on an SSH2 channel.
4209 */
4210static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4211{
51470298 4212 Ssh ssh = c->ssh;
4213
6b69f42e 4214 /*
4215 * Never send WINDOW_ADJUST for a channel that the remote side
4216 * already thinks it's closed; there's no point, since it won't
4217 * be sending any more data anyway.
4218 */
4219 if (c->closes != 0)
4220 return;
4221
5471d09a 4222 if (newwin > c->v.v2.locwindow) {
51470298 4223 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4224 ssh2_pkt_adduint32(ssh, c->remoteid);
4225 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4226 ssh2_pkt_send(ssh);
5471d09a 4227 c->v.v2.locwindow = newwin;
783415f8 4228 }
4229}
4230
4231/*
7cca0d81 4232 * Handle the SSH2 userauth and connection layers.
4233 */
51470298 4234static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4235{
51470298 4236 struct do_ssh2_authconn_state {
4237 enum {
4238 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4239 AUTH_PASSWORD,
4240 AUTH_KEYBOARD_INTERACTIVE
4241 } method;
4242 enum {
4243 AUTH_TYPE_NONE,
4244 AUTH_TYPE_PUBLICKEY,
4245 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4246 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4247 AUTH_TYPE_PASSWORD,
4248 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4249 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4250 } type;
4251 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4252 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4253 int kbd_inter_running;
4254 int we_are_in;
4255 int num_prompts, curr_prompt, echo;
4256 char username[100];
4257 int got_username;
4258 char pwprompt[200];
4259 char password[100];
4260 void *publickey_blob;
4261 int publickey_bloblen;
4262 unsigned char request[5], *response, *p;
4263 int responselen;
4264 int keyi, nkeys;
4265 int authed;
4266 char *pkblob, *alg, *commentp;
4267 int pklen, alglen, commentlen;
4268 int siglen, retlen, len;
4269 char *q, *agentreq, *ret;
4270 int try_send;
4271 };
4272 crState(do_ssh2_authconn_state);
4273
4274 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4275
7cca0d81 4276 /*
4277 * Request userauth protocol, and await a response to it.
4278 */
51470298 4279 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4280 ssh2_pkt_addstring(ssh, "ssh-userauth");
4281 ssh2_pkt_send(ssh);
7cca0d81 4282 crWaitUntilV(ispkt);
51470298 4283 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4284 bombout(("Server refused user authentication protocol"));
4285 crReturnV;
8d5de777 4286 }
7cca0d81 4287
4288 /*
1408a877 4289 * We repeat this whole loop, including the username prompt,
4290 * until we manage a successful authentication. If the user
51470298 4291 * types the wrong _password_, they can be sent back to the
4292 * beginning to try another username, if this is configured on.
4293 * (If they specify a username in the config, they are never
4294 * asked, even if they do give a wrong password.)
1408a877 4295 *
4296 * I think this best serves the needs of
4297 *
4298 * - the people who have no configuration, no keys, and just
4299 * want to try repeated (username,password) pairs until they
4300 * type both correctly
4301 *
4302 * - people who have keys and configuration but occasionally
4303 * need to fall back to passwords
4304 *
4305 * - people with a key held in Pageant, who might not have
4306 * logged in to a particular machine before; so they want to
4307 * type a username, and then _either_ their key will be
4308 * accepted, _or_ they will type a password. If they mistype
4309 * the username they will want to be able to get back and
4310 * retype it!
7cca0d81 4311 */
51470298 4312 s->username[0] = '\0';
4313 s->got_username = FALSE;
1408a877 4314 do {
1408a877 4315 /*
4316 * Get a username.
4317 */
51470298 4318 if (s->got_username && !cfg.change_username) {
5bb641e1 4319 /*
4320 * We got a username last time round this loop, and
4321 * with change_username turned off we don't try to get
4322 * it again.
4323 */
4324 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4325 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4326 if (!ssh_get_line("login as: ",
51470298 4327 s->username, sizeof(s->username), FALSE)) {
32874aea 4328 /*
4329 * get_line failed to get a username.
4330 * Terminate.
4331 */
4332 logevent("No username provided. Abandoning session.");
51470298 4333 ssh->state = SSH_STATE_CLOSED;
32874aea 4334 crReturnV;
4335 }
4336 } else {
51470298 4337 int ret; /* need not be saved across crReturn */
4338 c_write_str(ssh, "login as: ");
4339 ssh->send_ok = 1;
4340 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4341 do {
32874aea 4342 crWaitUntilV(!ispkt);
51470298 4343 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4344 } while (ret == 0);
4345 if (ret < 0)
4346 cleanup_exit(0);
32874aea 4347 }
51470298 4348 c_write_str(ssh, "\r\n");
4349 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4350 } else {
4351 char stuff[200];
51470298 4352 strncpy(s->username, cfg.username, sizeof(s->username));
4353 s->username[sizeof(s->username)-1] = '\0';
65a22376 4354 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
51470298 4355 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4356 c_write_str(ssh, stuff);
7cca0d81 4357 }
4358 }
51470298 4359 s->got_username = TRUE;
7cca0d81 4360
65a22376 4361 /*
1408a877 4362 * Send an authentication request using method "none": (a)
4363 * just in case it succeeds, and (b) so that we know what
4364 * authentication methods we can usefully try next.
65a22376 4365 */
51470298 4366 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4367
4368 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4369 ssh2_pkt_addstring(ssh, s->username);
4370 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4371 ssh2_pkt_addstring(ssh, "none"); /* method */
4372 ssh2_pkt_send(ssh);
4373 s->type = AUTH_TYPE_NONE;
4374 s->gotit = FALSE;
4375 s->we_are_in = FALSE;
4376
4377 s->tried_pubkey_config = FALSE;
4378 s->tried_agent = FALSE;
4379 s->tried_keyb_inter = FALSE;
4380 s->kbd_inter_running = FALSE;
396778f1 4381 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4382 if (*cfg.keyfile) {
231ee168 4383 int keytype;
4384 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4385 keytype = key_type(cfg.keyfile);
51470298 4386 if (keytype == SSH_KEYTYPE_SSH2) {
4387 s->publickey_blob =
4388 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4389 &s->publickey_bloblen);
4390 } else {
231ee168 4391 char msgbuf[256];
4392 logeventf("Unable to use this key file (%s)",
4393 key_type_to_str(keytype));
4394 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4395 cfg.keyfile, key_type_to_str(keytype));
51470298 4396 c_write_str(ssh, msgbuf);
4397 s->publickey_blob = NULL;
231ee168 4398 }
396778f1 4399 } else
51470298 4400 s->publickey_blob = NULL;
65a22376 4401
1408a877 4402 while (1) {
4403 /*
4404 * Wait for the result of the last authentication request.
4405 */
51470298 4406 if (!s->gotit)
1408a877 4407 crWaitUntilV(ispkt);
51470298 4408 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4409 char *banner;
4410 int size;
4411 /*
4412 * Don't show the banner if we're operating in
4413 * non-verbose non-interactive mode. (It's probably
4414 * a script, which means nobody will read the
4415 * banner _anyway_, and moreover the printing of
4416 * the banner will screw up processing on the
4417 * output of (say) plink.)
4418 */
4419 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4420 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4421 if (banner)
51470298 4422 c_write_untrusted(ssh, banner, size);
32874aea 4423 }
1408a877 4424 crWaitUntilV(ispkt);
4425 }
51470298 4426 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4427 logevent("Access granted");
51470298 4428 s->we_are_in = TRUE;
1408a877 4429 break;
4430 }
65a22376 4431
51470298 4432 if (s->kbd_inter_running &&
4433 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4434 /*
45068b27 4435 * This is either a further set-of-prompts packet
4436 * in keyboard-interactive authentication, or it's
4437 * the same one and we came back here with `gotit'
4438 * set. In the former case, we must reset the
4439 * curr_prompt variable.
b3186d64 4440 */
51470298 4441 if (!s->gotit)
4442 s->curr_prompt = 0;
4443 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4444 bombout(("Strange packet received during authentication: type %d",
51470298 4445 ssh->pktin.type));
38c4a8da 4446 crReturnV;
65a22376 4447 }
4448
51470298 4449 s->gotit = FALSE;
65a22376 4450
1408a877 4451 /*
4452 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4453 * we can look at the string in it and know what we can
4454 * helpfully try next.
4455 */
51470298 4456 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4457 char *methods;
4458 int methlen;
51470298 4459 ssh2_pkt_getstring(ssh, &methods, &methlen);
4460 s->kbd_inter_running = FALSE;
4461 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4462 /*
4463 * We have received an unequivocal Access
4464 * Denied. This can translate to a variety of
4465 * messages:
4466 *
4467 * - if we'd just tried "none" authentication,
4468 * it's not worth printing anything at all
4469 *
4470 * - if we'd just tried a public key _offer_,
4471 * the message should be "Server refused our
4472 * key" (or no message at all if the key
4473 * came from Pageant)
4474 *
4475 * - if we'd just tried anything else, the
4476 * message really should be "Access denied".
4477 *
4478 * Additionally, if we'd just tried password
4479 * authentication, we should break out of this
4480 * whole loop so as to go back to the username
4481 * prompt.
4482 */
51470298 4483 if (s->type == AUTH_TYPE_NONE) {
1408a877 4484 /* do nothing */
51470298 4485 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4486 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4487 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4488 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4489 logevent("Server refused public key");
51470298 4490 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4491 /* server declined keyboard-interactive; ignore */
1408a877 4492 } else {
51470298 4493 c_write_str(ssh, "Access denied\r\n");
1408a877 4494 logevent("Access denied");
51470298 4495 if (s->type == AUTH_TYPE_PASSWORD) {
4496 s->we_are_in = FALSE;
1408a877 4497 break;
4498 }
4499 }
4500 } else {
51470298 4501 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4502 logevent("Further authentication required");
4503 }
65a22376 4504
51470298 4505 s->can_pubkey =
32874aea 4506 in_commasep_string("publickey", methods, methlen);
51470298 4507 s->can_passwd =
32874aea 4508 in_commasep_string("password", methods, methlen);
51470298 4509 s->can_keyb_inter = cfg.try_ki_auth &&
761187b6 4510 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4511 }
65a22376 4512
51470298 4513 s->method = 0;
4514 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4515
0405e71f 4516 /*
4517 * Most password/passphrase prompts will be
4518 * non-echoing, so we set this to 0 by default.
4519 * Exception is that some keyboard-interactive prompts
4520 * can be echoing, in which case we'll set this to 1.
4521 */
51470298 4522 s->echo = 0;
0405e71f 4523
51470298 4524 if (!s->method && s->can_pubkey &&
4525 agent_exists() && !s->tried_agent) {
1983e559 4526 /*
4527 * Attempt public-key authentication using Pageant.
4528 */
1983e559 4529 void *r;
51470298 4530 s->authed = FALSE;
1983e559 4531
51470298 4532 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4533 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4534
51470298 4535 s->tried_agent = TRUE;
1983e559 4536
4537 logevent("Pageant is running. Requesting keys.");
4538
4539 /* Request the keys held by the agent. */
51470298 4540 PUT_32BIT(s->request, 1);
4541 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4542 agent_query(s->request, 5, &r, &s->responselen);
4543 s->response = (unsigned char *) r;
4544 if (s->response && s->responselen >= 5 &&
4545 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4546 s->p = s->response + 5;
4547 s->nkeys = GET_32BIT(s->p);
4548 s->p += 4;
32874aea 4549 {
4550 char buf[64];
51470298 4551 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4552 logevent(buf);
4553 }
51470298 4554 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4555 void *vret;
1983e559 4556
32874aea 4557 {
4558 char buf[64];
51470298 4559 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4560 logevent(buf);
4561 }
51470298 4562 s->pklen = GET_32BIT(s->p);
4563 s->p += 4;
4564 if (s->publickey_blob &&
4565 s->pklen == s->publickey_bloblen &&
4566 !memcmp(s->p, s->publickey_blob,
4567 s->publickey_bloblen)) {
396778f1 4568 logevent("This key matches configured key file");
51470298 4569 s->tried_pubkey_config = 1;
396778f1 4570 }
51470298 4571 s->pkblob = s->p;
4572 s->p += s->pklen;
4573 s->alglen = GET_32BIT(s->pkblob);
4574 s->alg = s->pkblob + 4;
4575 s->commentlen = GET_32BIT(s->p);
4576 s->p += 4;
4577 s->commentp = s->p;
4578 s->p += s->commentlen;
4579 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4580 ssh2_pkt_addstring(ssh, s->username);
4581 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4582 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4583 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4584 ssh2_pkt_addstring_start(ssh);
4585 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4586 ssh2_pkt_addstring_start(ssh);
4587 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4588 ssh2_pkt_send(ssh);
1983e559 4589
4590 crWaitUntilV(ispkt);
51470298 4591 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4592 logevent("Key refused");
4593 continue;
4594 }
4595
32874aea 4596 if (flags & FLAG_VERBOSE) {
51470298 4597 c_write_str(ssh, "Authenticating with "
4598 "public key \"");
4599 c_write(ssh, s->commentp, s->commentlen);
4600 c_write_str(ssh, "\" from agent\r\n");
32874aea 4601 }
1983e559 4602
4603 /*
4604 * Server is willing to accept the key.
4605 * Construct a SIGN_REQUEST.
4606 */
51470298 4607 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4608 ssh2_pkt_addstring(ssh, s->username);
4609 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4610 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4611 ssh2_pkt_addbool(ssh, TRUE);
4612 ssh2_pkt_addstring_start(ssh);
4613 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4614 ssh2_pkt_addstring_start(ssh);
4615 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4616
4617 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4618 s->len = 1; /* message type */
4619 s->len += 4 + s->pklen; /* key blob */
4620 s->len += 4 + s->siglen; /* data to sign */
4621 s->len += 4; /* flags */
4622 s->agentreq = smalloc(4 + s->len);
4623 PUT_32BIT(s->agentreq, s->len);
4624 s->q = s->agentreq + 4;
4625 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4626 PUT_32BIT(s->q, s->pklen);
4627 s->q += 4;
4628 memcpy(s->q, s->pkblob, s->pklen);
4629 s->q += s->pklen;
4630 PUT_32BIT(s->q, s->siglen);
4631 s->q += 4;
1983e559 4632 /* Now the data to be signed... */
51470298 4633 PUT_32BIT(s->q, 20);
4634 s->q += 4;
4635 memcpy(s->q, ssh->v2_session_id, 20);
4636 s->q += 20;
4637 memcpy(s->q, ssh->pktout.data + 5,
4638 ssh->pktout.length - 5);
4639 s->q += ssh->pktout.length - 5;
1983e559 4640 /* And finally the (zero) flags word. */
51470298 4641 PUT_32BIT(s->q, 0);
4642 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4643 s->ret = vret;
4644 sfree(s->agentreq);
4645 if (s->ret) {
4646 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4647 logevent("Sending Pageant's response");
51470298 4648 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4649 s->ret + 9,
4650 GET_32BIT(s->ret + 5));
4651 ssh2_pkt_send(ssh);
4652 s->authed = TRUE;
1983e559 4653 break;
4654 } else {
32874aea 4655 logevent
4656 ("Pageant failed to answer challenge");
51470298 4657 sfree(s->ret);
1983e559 4658 }
4659 }
4660 }
51470298 4661 if (s->authed)
1983e559 4662 continue;
4663 }
4664 }
4665
51470298 4666 if (!s->method && s->can_pubkey && s->publickey_blob
4667 && !s->tried_pubkey_config) {
1408a877 4668 unsigned char *pub_blob;
4669 char *algorithm, *comment;
4670 int pub_blob_len;
65a22376 4671
51470298 4672 s->tried_pubkey_config = TRUE;
65a22376 4673
51470298 4674 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4675 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4676
65a22376 4677 /*
1408a877 4678 * Try the public key supplied in the configuration.
4679 *
4680 * First, offer the public blob to see if the server is
4681 * willing to accept it.
65a22376 4682 */
1408a877 4683 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4684 &pub_blob_len);
4685 if (pub_blob) {
51470298 4686 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4687 ssh2_pkt_addstring(ssh, s->username);
4688 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4689 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4690 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4691 ssh2_pkt_addstring(ssh, algorithm);
4692 ssh2_pkt_addstring_start(ssh);
4693 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4694 ssh2_pkt_send(ssh);
32874aea 4695 logevent("Offered public key"); /* FIXME */
1408a877 4696
4697 crWaitUntilV(ispkt);
51470298 4698 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4699 s->gotit = TRUE;
4700 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4701 continue; /* key refused; give up on it */
1408a877 4702 }
65a22376 4703
1408a877 4704 logevent("Offer of public key accepted");
65a22376 4705 /*
1408a877 4706 * Actually attempt a serious authentication using
4707 * the key.
65a22376 4708 */
1408a877 4709 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
51470298 4710 sprintf(s->pwprompt,
32874aea 4711 "Passphrase for key \"%.100s\": ",
4712 comment);
51470298 4713 s->need_pw = TRUE;
1408a877 4714 } else {
51470298 4715 s->need_pw = FALSE;
1408a877 4716 }
51470298 4717 c_write_str(ssh, "Authenticating with public key \"");
4718 c_write_str(ssh, comment);
4719 c_write_str(ssh, "\"\r\n");
4720 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4721 }
1408a877 4722 }
4723
51470298 4724 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4725 s->method = AUTH_KEYBOARD_INTERACTIVE;
4726 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4727 s->tried_keyb_inter = TRUE;
af659722 4728
51470298 4729 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4730 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4731
51470298 4732 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4733 ssh2_pkt_addstring(ssh, s->username);
4734 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4735 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4736 ssh2_pkt_addstring(ssh, ""); /* lang */
4737 ssh2_pkt_addstring(ssh, "");
4738 ssh2_pkt_send(ssh);
af659722 4739
4740 crWaitUntilV(ispkt);
51470298 4741 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4742 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4743 s->gotit = TRUE;
af659722 4744 logevent("Keyboard-interactive authentication refused");
51470298 4745 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4746 continue;
4747 }
4748
51470298 4749 s->kbd_inter_running = TRUE;
4750 s->curr_prompt = 0;
af659722 4751 }
4752
51470298 4753 if (s->kbd_inter_running) {
4754 s->method = AUTH_KEYBOARD_INTERACTIVE;
4755 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4756 s->tried_keyb_inter = TRUE;
af659722 4757
51470298 4758 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4759 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4760
51470298 4761 if (s->curr_prompt == 0) {
45068b27 4762 /*
4763 * We've got a fresh USERAUTH_INFO_REQUEST.
4764 * Display header data, and start going through
4765 * the prompts.
4766 */
4767 char *name, *inst, *lang;
4768 int name_len, inst_len, lang_len;
4769
51470298 4770 ssh2_pkt_getstring(ssh, &name, &name_len);
4771 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4772 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 4773 if (name_len > 0) {
51470298 4774 c_write_untrusted(ssh, name, name_len);
4775 c_write_str(ssh, "\r\n");
45068b27 4776 }
4777 if (inst_len > 0) {
51470298 4778 c_write_untrusted(ssh, inst, inst_len);
4779 c_write_str(ssh, "\r\n");
45068b27 4780 }
51470298 4781 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 4782 }
af659722 4783
45068b27 4784 /*
4785 * If there are prompts remaining in the packet,
4786 * display one and get a response.
4787 */
51470298 4788 if (s->curr_prompt < s->num_prompts) {
45068b27 4789 char *prompt;
4790 int prompt_len;
af659722 4791
51470298 4792 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 4793 if (prompt_len > 0) {
51470298 4794 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4795 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4796 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 4797 } else {
51470298 4798 strcpy(s->pwprompt,
45068b27 4799 "<server failed to send prompt>: ");
4800 }
51470298 4801 s->echo = ssh2_pkt_getbool(ssh);
4802 s->need_pw = TRUE;
45068b27 4803 } else
51470298 4804 s->need_pw = FALSE;
af659722 4805 }
4806
51470298 4807 if (!s->method && s->can_passwd) {
4808 s->method = AUTH_PASSWORD;
4809 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4810 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4811 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4812 ssh->savedhost);
4813 s->need_pw = TRUE;
1408a877 4814 }
4815
51470298 4816 if (s->need_pw) {
fa17a66e 4817 if (ssh_get_line) {
51470298 4818 if (!ssh_get_line(s->pwprompt, s->password,
4819 sizeof(s->password), TRUE)) {
1408a877 4820 /*
fa17a66e 4821 * get_line failed to get a password (for
4822 * example because one was supplied on the
4823 * command line which has already failed to
4824 * work). Terminate.
1408a877 4825 */
51470298 4826 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4827 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4828 ssh2_pkt_addstring(ssh, "No more passwords available"
4829 " to try");
4830 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4831 ssh2_pkt_send(ssh);
247308b5 4832 logevent("Unable to authenticate");
2bc6a386 4833 connection_fatal("Unable to authenticate");
51470298 4834 ssh->state = SSH_STATE_CLOSED;
1408a877 4835 crReturnV;
4836 }
4837 } else {
51470298 4838 int ret; /* need not be saved across crReturn */
4839 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4840 ssh->send_ok = 1;
1408a877 4841
51470298 4842 setup_userpass_input(ssh, s->password,
4843 sizeof(s->password), s->echo);
0405e71f 4844 do {
1408a877 4845 crWaitUntilV(!ispkt);
51470298 4846 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4847 } while (ret == 0);
4848 if (ret < 0)
4849 cleanup_exit(0);
51470298 4850 c_write_str(ssh, "\r\n");
65a22376 4851 }
65a22376 4852 }
65a22376 4853
51470298 4854 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 4855 /*
4856 * We have our passphrase. Now try the actual authentication.
4857 */
4858 struct ssh2_userkey *key;
65a22376 4859
51470298 4860 key = ssh2_load_userkey(cfg.keyfile, s->password);
1408a877 4861 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4862 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 4863 c_write_str(ssh, "Wrong passphrase\r\n");
4864 s->tried_pubkey_config = FALSE;
1408a877 4865 } else {
51470298 4866 c_write_str(ssh, "Unable to load private key\r\n");
4867 s->tried_pubkey_config = TRUE;
1408a877 4868 }
4869 /* Send a spurious AUTH_NONE to return to the top. */
51470298 4870 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4871 ssh2_pkt_addstring(ssh, s->username);
4872 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4873 ssh2_pkt_addstring(ssh, "none"); /* method */
4874 ssh2_pkt_send(ssh);
4875 s->type = AUTH_TYPE_NONE;
1408a877 4876 } else {
1dd353b5 4877 unsigned char *pkblob, *sigblob, *sigdata;
4878 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4879
1408a877 4880 /*
4881 * We have loaded the private key and the server
4882 * has announced that it's willing to accept it.
4883 * Hallelujah. Generate a signature and send it.
4884 */
51470298 4885 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4886 ssh2_pkt_addstring(ssh, s->username);
4887 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4888 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4889 ssh2_pkt_addbool(ssh, TRUE);
4890 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 4891 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 4892 ssh2_pkt_addstring_start(ssh);
4893 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
1408a877 4894
4895 /*
4896 * The data to be signed is:
4897 *
4898 * string session-id
4899 *
4900 * followed by everything so far placed in the
4901 * outgoing packet.
4902 */
51470298 4903 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
1408a877 4904 sigdata = smalloc(sigdata_len);
4905 PUT_32BIT(sigdata, 20);
51470298 4906 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4907 memcpy(sigdata + 24, ssh->pktout.data + 5,
4908 ssh->pktout.length - 5);
1dd353b5 4909 sigblob = key->alg->sign(key->data, sigdata,
4910 sigdata_len, &sigblob_len);
51470298 4911 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 4912 sigblob, sigblob_len);
4913 sfree(pkblob);
4914 sfree(sigblob);
1408a877 4915 sfree(sigdata);
4916
51470298 4917 ssh2_pkt_send(ssh);
4918 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 4919 }
51470298 4920 } else if (s->method == AUTH_PASSWORD) {
65a22376 4921 /*
1408a877 4922 * We send the password packet lumped tightly together with
4923 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4924 * string long enough to make the total length of the two
4925 * packets constant. This should ensure that a passive
4926 * listener doing traffic analyis can't work out the length
4927 * of the password.
4928 *
4929 * For this to work, we need an assumption about the
4930 * maximum length of the password packet. I think 256 is
4931 * pretty conservative. Anyone using a password longer than
4932 * that probably doesn't have much to worry about from
4933 * people who find out how long their password is!
65a22376 4934 */
51470298 4935 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4936 ssh2_pkt_addstring(ssh, s->username);
4937 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4938 ssh2_pkt_addstring(ssh, "password");
4939 ssh2_pkt_addbool(ssh, FALSE);
4940 ssh2_pkt_addstring(ssh, s->password);
4941 ssh2_pkt_defer(ssh);
65a22376 4942 /*
1408a877 4943 * We'll include a string that's an exact multiple of the
4944 * cipher block size. If the cipher is NULL for some
4945 * reason, we don't do this trick at all because we gain
4946 * nothing by it.
65a22376 4947 */
51470298 4948 if (ssh->cscipher) {
32874aea 4949 int stringlen, i;
4950
51470298 4951 stringlen = (256 - ssh->deferred_len);
4952 stringlen += ssh->cscipher->blksize - 1;
4953 stringlen -= (stringlen % ssh->cscipher->blksize);
4954 if (ssh->cscomp) {
32874aea 4955 /*
4956 * Temporarily disable actual compression,
4957 * so we can guarantee to get this string
4958 * exactly the length we want it. The
4959 * compression-disabling routine should
4960 * return an integer indicating how many
4961 * bytes we should adjust our string length
4962 * by.
4963 */
5366aed8 4964 stringlen -=
4965 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 4966 }
51470298 4967 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4968 ssh2_pkt_addstring_start(ssh);
6e9e9520 4969 for (i = 0; i < stringlen; i++) {
32874aea 4970 char c = (char) random_byte();
51470298 4971 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 4972 }
51470298 4973 ssh2_pkt_defer(ssh);
65a22376 4974 }
51470298 4975 ssh_pkt_defersend(ssh);
0d43337a 4976 logevent("Sent password");
51470298 4977 s->type = AUTH_TYPE_PASSWORD;
4978 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4979 if (s->curr_prompt == 0) {
4980 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4981 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 4982 }
51470298 4983 if (s->need_pw) { /* only add pw if we just got one! */
4984 ssh2_pkt_addstring(ssh, s->password);
4985 memset(s->password, 0, sizeof(s->password));
4986 s->curr_prompt++;
45068b27 4987 }
51470298 4988 if (s->curr_prompt >= s->num_prompts) {
4989 ssh2_pkt_send(ssh);
45068b27 4990 } else {
4991 /*
4992 * If there are prompts remaining, we set
4993 * `gotit' so that we won't attempt to get
4994 * another packet. Then we go back round the
4995 * loop and will end up retrieving another
4996 * prompt out of the existing packet. Funky or
4997 * what?
4998 */
51470298 4999 s->gotit = TRUE;
45068b27 5000 }
51470298 5001 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5002 } else {
51470298 5003 c_write_str(ssh, "No supported authentication methods"
5004 " left to try!\r\n");
5005 logevent("No supported authentications offered."
5006 " Disconnecting");
5007 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5008 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5009 ssh2_pkt_addstring(ssh, "No supported authentication"
5010 " methods available");
5011 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5012 ssh2_pkt_send(ssh);
5013 ssh->state = SSH_STATE_CLOSED;
1408a877 5014 crReturnV;
65a22376 5015 }
65a22376 5016 }
51470298 5017 } while (!s->we_are_in);
7cca0d81 5018
5019 /*
5020 * Now we're authenticated for the connection protocol. The
5021 * connection protocol will automatically have started at this
5022 * point; there's no need to send SERVICE_REQUEST.
5023 */
5024
5025 /*
5026 * So now create a channel with a session in it.
5027 */
51470298 5028 ssh->channels = newtree234(ssh_channelcmp);
5029 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5030 ssh->mainchan->ssh = ssh;
5031 ssh->mainchan->localid = alloc_channel_id(ssh);
5032 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5033 ssh2_pkt_addstring(ssh, "session");
5034 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5035 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5036 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5037 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5038 ssh2_pkt_send(ssh);
7cca0d81 5039 crWaitUntilV(ispkt);
51470298 5040 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 5041 bombout(("Server refused to open a session"));
5042 crReturnV;
5043 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5044 }
51470298 5045 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
32874aea 5046 bombout(("Server's channel confirmation cited wrong channel"));
5047 crReturnV;
7cca0d81 5048 }
51470298 5049 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5050 ssh->mainchan->type = CHAN_MAINSESSION;
5051 ssh->mainchan->closes = 0;
5052 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5053 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5054 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5055 add234(ssh->channels, ssh->mainchan);
7cca0d81 5056 logevent("Opened channel for session");
5057
5058 /*
783415f8 5059 * Potentially enable X11 forwarding.
5060 */
5061 if (cfg.x11_forward) {
32874aea 5062 char proto[20], data[64];
5063 logevent("Requesting X11 forwarding");
302121de 5064 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5065 data, sizeof(data));
51470298 5066 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5067 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5068 ssh2_pkt_addstring(ssh, "x11-req");
5069 ssh2_pkt_addbool(ssh, 1); /* want reply */
5070 ssh2_pkt_addbool(ssh, 0); /* many connections */
5071 ssh2_pkt_addstring(ssh, proto);
5072 ssh2_pkt_addstring(ssh, data);
5073 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5074 ssh2_pkt_send(ssh);
32874aea 5075
5076 do {
5077 crWaitUntilV(ispkt);
51470298 5078 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5079 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5080 struct ssh_channel *c;
51470298 5081 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5082 if (!c)
5083 continue; /* nonexistent channel */
51470298 5084 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5085 }
51470298 5086 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5087
51470298 5088 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5089 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5090 bombout(("Unexpected response to X11 forwarding request:"
51470298 5091 " packet type %d", ssh->pktin.type));
32874aea 5092 crReturnV;
5093 }
5094 logevent("X11 forwarding refused");
5095 } else {
5096 logevent("X11 forwarding enabled");
51470298 5097 ssh->X11_fwd_enabled = TRUE;
32874aea 5098 }
783415f8 5099 }
5100
5101 /*
bc240b21 5102 * Enable port forwardings.
5103 */
5104 {
bc240b21 5105 char type;
5106 int n;
a4fc0d74 5107 int sport,dport,sserv,dserv;
bc240b21 5108 char sports[256], dports[256], host[256];
5109 char buf[1024];
a4fc0d74 5110 struct servent *se;
bc240b21 5111
51470298 5112 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5113 /* Add port forwardings. */
51470298 5114 ssh->portfwd_strptr = cfg.portfwd;
5115 while (*ssh->portfwd_strptr) {
5116 type = *ssh->portfwd_strptr++;
bc240b21 5117 n = 0;
51470298 5118 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5119 sports[n++] = *ssh->portfwd_strptr++;
bc240b21 5120 sports[n] = 0;
51470298 5121 if (*ssh->portfwd_strptr == '\t')
5122 ssh->portfwd_strptr++;
bc240b21 5123 n = 0;
51470298 5124 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5125 host[n++] = *ssh->portfwd_strptr++;
bc240b21 5126 host[n] = 0;
51470298 5127 if (*ssh->portfwd_strptr == ':')
5128 ssh->portfwd_strptr++;
bc240b21 5129 n = 0;
51470298 5130 while (*ssh->portfwd_strptr)
5131 dports[n++] = *ssh->portfwd_strptr++;
bc240b21 5132 dports[n] = 0;
51470298 5133 ssh->portfwd_strptr++;
bc240b21 5134 dport = atoi(dports);
a4fc0d74 5135 dserv = 0;
5136 if (dport == 0) {
5137 dserv = 1;
5138 se = getservbyname(dports, NULL);
5139 if (se != NULL) {
5140 dport = ntohs(se->s_port);
5141 } else {
5142 sprintf(buf,
5143 "Service lookup failed for destination port \"%s\"",
5144 dports);
5145 logevent(buf);
5146 }
5147 }
bc240b21 5148 sport = atoi(sports);
a4fc0d74 5149 sserv = 0;
5150 if (sport == 0) {
5151 sserv = 1;
5152 se = getservbyname(sports, NULL);
5153 if (se != NULL) {
5154 sport = ntohs(se->s_port);
5155 } else {
5156 sprintf(buf,
5157 "Service lookup failed for source port \"%s\"",
5158 sports);
5159 logevent(buf);
5160 }
5161 }
bc240b21 5162 if (sport && dport) {
5163 if (type == 'L') {
6b78788a 5164 pfd_addforward(host, dport, sport, ssh);
a4fc0d74 5165 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5166 " %s:%.*s%.*s%d%.*s",
5167 sserv ? strlen(sports) : 0, sports,
5168 sserv, "(", sport, sserv, ")",
5169 host,
5170 dserv ? strlen(dports) : 0, dports,
5171 dserv, "(", dport, dserv, ")");
bc240b21 5172 logevent(buf);
5173 } else {
5174 struct ssh_rportfwd *pf;
5175 pf = smalloc(sizeof(*pf));
5176 strcpy(pf->dhost, host);
5177 pf->dport = dport;
5178 pf->sport = sport;
51470298 5179 if (add234(ssh->rportfwds, pf) != pf) {
bc240b21 5180 sprintf(buf,
95bc8819 5181 "Duplicate remote port forwarding to %s:%d",
bc240b21 5182 host, dport);
5183 logevent(buf);
5184 sfree(pf);
5185 } else {
a4fc0d74 5186 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5187 " forward to %s:%.*s%.*s%d%.*s",
5188 sserv ? strlen(sports) : 0, sports,
5189 sserv, "(", sport, sserv, ")",
5190 host,
5191 dserv ? strlen(dports) : 0, dports,
5192 dserv, "(", dport, dserv, ")");
bc240b21 5193 logevent(buf);
51470298 5194 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5195 ssh2_pkt_addstring(ssh, "tcpip-forward");
5196 ssh2_pkt_addbool(ssh, 1);/* want reply */
beefa433 5197 if (cfg.rport_acceptall)
51470298 5198 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5199 else
51470298 5200 ssh2_pkt_addstring(ssh, "127.0.0.1");
5201 ssh2_pkt_adduint32(ssh, sport);
5202 ssh2_pkt_send(ssh);
bc240b21 5203
5204 do {
5205 crWaitUntilV(ispkt);
51470298 5206 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5207 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5208 struct ssh_channel *c;
51470298 5209 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5210 if (!c)
5211 continue;/* nonexistent channel */
51470298 5212 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5213 }
51470298 5214 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5215
51470298 5216 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5217 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5218 bombout(("Unexpected response to port "
5219 "forwarding request: packet type %d",
51470298 5220 ssh->pktin.type));
bc240b21 5221 crReturnV;
5222 }
5223 logevent("Server refused this port forwarding");
5224 } else {
5225 logevent("Remote port forwarding enabled");
5226 }
5227 }
5228 }
5229 }
5230 }
5231 }
5232
5233 /*
36c2a3e9 5234 * Potentially enable agent forwarding.
5235 */
5236 if (cfg.agentfwd && agent_exists()) {
32874aea 5237 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5238 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5239 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5240 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5241 ssh2_pkt_addbool(ssh, 1); /* want reply */
5242 ssh2_pkt_send(ssh);
32874aea 5243
5244 do {
5245 crWaitUntilV(ispkt);
51470298 5246 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5247 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5248 struct ssh_channel *c;
51470298 5249 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5250 if (!c)
5251 continue; /* nonexistent channel */
51470298 5252 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5253 }
51470298 5254 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5255
51470298 5256 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5257 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5258 bombout(("Unexpected response to agent forwarding request:"
51470298 5259 " packet type %d", ssh->pktin.type));
32874aea 5260 crReturnV;
5261 }
5262 logevent("Agent forwarding refused");
5263 } else {
5264 logevent("Agent forwarding enabled");
51470298 5265 ssh->agentfwd_enabled = TRUE;
32874aea 5266 }
36c2a3e9 5267 }
5268
5269 /*
7cca0d81 5270 * Now allocate a pty for the session.
5271 */
67779be7 5272 if (!cfg.nopty) {
51470298 5273 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5274 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5275 ssh2_pkt_addstring(ssh, "pty-req");
5276 ssh2_pkt_addbool(ssh, 1); /* want reply */
5277 ssh2_pkt_addstring(ssh, cfg.termtype);
5278 ssh2_pkt_adduint32(ssh, ssh->term_width);
5279 ssh2_pkt_adduint32(ssh, ssh->term_height);
5280 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5281 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5282 ssh2_pkt_addstring_start(ssh);
5283 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5284 ssh2_pkt_send(ssh);
5285 ssh->state = SSH_STATE_INTERMED;
32874aea 5286
5287 do {
5288 crWaitUntilV(ispkt);
51470298 5289 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5290 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5291 struct ssh_channel *c;
51470298 5292 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5293 if (!c)
5294 continue; /* nonexistent channel */
51470298 5295 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5296 }
51470298 5297 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5298
51470298 5299 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5300 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5301 bombout(("Unexpected response to pty request:"
51470298 5302 " packet type %d", ssh->pktin.type));
32874aea 5303 crReturnV;
5304 }
51470298 5305 c_write_str(ssh, "Server refused to allocate pty\r\n");
5306 ssh->editing = ssh->echoing = 1;
32874aea 5307 } else {
5308 logevent("Allocated pty");
5309 }
0965bee0 5310 } else {
51470298 5311 ssh->editing = ssh->echoing = 1;
7cca0d81 5312 }
5313
5314 /*
fd5e5847 5315 * Start a shell or a remote command. We may have to attempt
5316 * this twice if the config data has provided a second choice
5317 * of command.
7cca0d81 5318 */
fd5e5847 5319 while (1) {
5320 int subsys;
5321 char *cmd;
5322
51470298 5323 if (ssh->fallback_cmd) {
fd5e5847 5324 subsys = cfg.ssh_subsys2;
5325 cmd = cfg.remote_cmd_ptr2;
5326 } else {
5327 subsys = cfg.ssh_subsys;
5328 cmd = cfg.remote_cmd_ptr;
5329 }
5330
51470298 5331 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5332 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5333 if (subsys) {
51470298 5334 ssh2_pkt_addstring(ssh, "subsystem");
5335 ssh2_pkt_addbool(ssh, 1); /* want reply */
5336 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5337 } else if (*cmd) {
51470298 5338 ssh2_pkt_addstring(ssh, "exec");
5339 ssh2_pkt_addbool(ssh, 1); /* want reply */
5340 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5341 } else {
51470298 5342 ssh2_pkt_addstring(ssh, "shell");
5343 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5344 }
51470298 5345 ssh2_pkt_send(ssh);
fd5e5847 5346 do {
5347 crWaitUntilV(ispkt);
51470298 5348 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5349 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5350 struct ssh_channel *c;
51470298 5351 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5352 if (!c)
5353 continue; /* nonexistent channel */
51470298 5354 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5355 }
51470298 5356 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5357 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5358 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5359 bombout(("Unexpected response to shell/command request:"
51470298 5360 " packet type %d", ssh->pktin.type));
fd5e5847 5361 crReturnV;
5362 }
5363 /*
5364 * We failed to start the command. If this is the
5365 * fallback command, we really are finished; if it's
5366 * not, and if the fallback command exists, try falling
5367 * back to it before complaining.
5368 */
51470298 5369 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5370 logevent("Primary command failed; attempting fallback");
51470298 5371 ssh->fallback_cmd = TRUE;
fd5e5847 5372 continue;
5373 }
5374 bombout(("Server refused to start a shell/command"));
32874aea 5375 crReturnV;
fd5e5847 5376 } else {
5377 logevent("Started a shell/command");
32874aea 5378 }
fd5e5847 5379 break;
7cca0d81 5380 }
5381
51470298 5382 ssh->state = SSH_STATE_SESSION;
5383 if (ssh->size_needed)
5384 ssh_size(ssh, ssh->term_width, ssh->term_height);
5385 if (ssh->eof_needed)
5386 ssh_special(ssh, TS_EOF);
6e48c3fe 5387
7cca0d81 5388 /*
5389 * Transfer data!
5390 */
b9d7bcad 5391 if (ssh->ldisc)
5392 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5393 ssh->send_ok = 1;
7cca0d81 5394 while (1) {
e5574168 5395 crReturnV;
51470298 5396 s->try_send = FALSE;
7cca0d81 5397 if (ispkt) {
51470298 5398 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5399 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5400 char *data;
5401 int length;
51470298 5402 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5403 struct ssh_channel *c;
51470298 5404 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5405 if (!c)
5406 continue; /* nonexistent channel */
51470298 5407 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5408 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5409 continue; /* extended but not stderr */
51470298 5410 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5411 if (data) {
5471d09a 5412 int bufsize;
5413 c->v.v2.locwindow -= length;
32874aea 5414 switch (c->type) {
5415 case CHAN_MAINSESSION:
5471d09a 5416 bufsize =
51470298 5417 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5418 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5419 data, length);
32874aea 5420 break;
5421 case CHAN_X11:
5471d09a 5422 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5423 break;
d74d141c 5424 case CHAN_SOCKDATA:
5471d09a 5425 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5426 break;
36c2a3e9 5427 case CHAN_AGENT:
32874aea 5428 while (length > 0) {
5429 if (c->u.a.lensofar < 4) {
5430 int l = min(4 - c->u.a.lensofar, length);
5431 memcpy(c->u.a.msglen + c->u.a.lensofar,
5432 data, l);
5433 data += l;
5434 length -= l;
5435 c->u.a.lensofar += l;
5436 }
5437 if (c->u.a.lensofar == 4) {
5438 c->u.a.totallen =
5439 4 + GET_32BIT(c->u.a.msglen);
5440 c->u.a.message = smalloc(c->u.a.totallen);
5441 memcpy(c->u.a.message, c->u.a.msglen, 4);
5442 }
5443 if (c->u.a.lensofar >= 4 && length > 0) {
5444 int l =
5445 min(c->u.a.totallen - c->u.a.lensofar,
5446 length);
5447 memcpy(c->u.a.message + c->u.a.lensofar,
5448 data, l);
5449 data += l;
5450 length -= l;
5451 c->u.a.lensofar += l;
5452 }
5453 if (c->u.a.lensofar == c->u.a.totallen) {
5454 void *reply, *sentreply;
5455 int replylen;
5456 agent_query(c->u.a.message,
5457 c->u.a.totallen, &reply,
5458 &replylen);
5459 if (reply)
5460 sentreply = reply;
5461 else {
5462 /* Fake SSH_AGENT_FAILURE. */
5463 sentreply = "\0\0\0\1\5";
5464 replylen = 5;
5465 }
51470298 5466 ssh2_add_channel_data(c, sentreply, replylen);
5467 s->try_send = TRUE;
32874aea 5468 if (reply)
5469 sfree(reply);
5470 sfree(c->u.a.message);
5471 c->u.a.lensofar = 0;
5472 }
5473 }
5471d09a 5474 bufsize = 0;
32874aea 5475 break;
5476 }
5477 /*
5471d09a 5478 * If we are not buffering too much data,
5479 * enlarge the window again at the remote side.
32874aea 5480 */
5471d09a 5481 if (bufsize < OUR_V2_WINSIZE)
5482 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5483 }
51470298 5484 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5485 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5486 struct ssh_channel *c;
5487
51470298 5488 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5489 if (!c)
5490 continue; /* nonexistent channel */
5491
5492 if (c->type == CHAN_X11) {
5493 /*
5494 * Remote EOF on an X11 channel means we should
5495 * wrap up and close the channel ourselves.
5496 */
5497 x11_close(c->u.x11.s);
5498 sshfwd_close(c);
5499 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5500 sshfwd_close(c);
d74d141c 5501 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5502 pfd_close(c->u.pfd.s);
5503 sshfwd_close(c);
36c2a3e9 5504 }
51470298 5505 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5506 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5507 struct ssh_channel *c;
5508
51470298 5509 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5510 if (!c || ((int)c->remoteid) == -1) {
5511 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5512 c ? "half-open" : "nonexistent", i));
5513 }
32874aea 5514 /* Do pre-close processing on the channel. */
5515 switch (c->type) {
5516 case CHAN_MAINSESSION:
5517 break; /* nothing to see here, move along */
5518 case CHAN_X11:
92f157bd 5519 if (c->u.x11.s != NULL)
5520 x11_close(c->u.x11.s);
5521 sshfwd_close(c);
32874aea 5522 break;
5523 case CHAN_AGENT:
92f157bd 5524 sshfwd_close(c);
32874aea 5525 break;
d74d141c 5526 case CHAN_SOCKDATA:
92f157bd 5527 if (c->u.pfd.s != NULL)
5528 pfd_close(c->u.pfd.s);
5529 sshfwd_close(c);
bc240b21 5530 break;
32874aea 5531 }
92f157bd 5532 if (c->closes == 0) {
51470298 5533 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5534 ssh2_pkt_adduint32(ssh, c->remoteid);
5535 ssh2_pkt_send(ssh);
92f157bd 5536 }
51470298 5537 del234(ssh->channels, c);
5471d09a 5538 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5539 sfree(c);
5540
5541 /*
5542 * See if that was the last channel left open.
5543 */
51470298 5544 if (count234(ssh->channels) == 0) {
ca2914d1 5545#if 0
5546 /*
5547 * We used to send SSH_MSG_DISCONNECT here,
5548 * because I'd believed that _every_ conforming
5549 * SSH2 connection had to end with a disconnect
5550 * being sent by at least one side; apparently
5551 * I was wrong and it's perfectly OK to
5552 * unceremoniously slam the connection shut
5553 * when you're done, and indeed OpenSSH feels
5554 * this is more polite than sending a
5555 * DISCONNECT. So now we don't.
5556 */
32874aea 5557 logevent("All channels closed. Disconnecting");
51470298 5558 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5559 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5560 ssh2_pkt_addstring(ssh, "All open channels closed");
5561 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5562 ssh2_pkt_send(ssh);
ca2914d1 5563#endif
51470298 5564 ssh->state = SSH_STATE_CLOSED;
32874aea 5565 crReturnV;
5566 }
5567 continue; /* remote sends close; ignore (FIXME) */
51470298 5568 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5569 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5570 struct ssh_channel *c;
51470298 5571 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5572 if (!c)
5573 continue; /* nonexistent channel */
51470298 5574 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5575 s->try_send = TRUE;
5576 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5577 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5578 struct ssh_channel *c;
51470298 5579 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5580 if (!c)
5581 continue; /* nonexistent channel */
5582 if (c->type != CHAN_SOCKDATA_DORMANT)
5583 continue; /* dunno why they're confirming this */
51470298 5584 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5585 c->type = CHAN_SOCKDATA;
51470298 5586 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5587 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5588 if (c->u.pfd.s)
5589 pfd_confirm(c->u.pfd.s);
5590 if (c->closes) {
5591 /*
5592 * We have a pending close on this channel,
5593 * which we decided on before the server acked
5594 * the channel open. So now we know the
5595 * remoteid, we can close it again.
5596 */
51470298 5597 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5598 ssh2_pkt_adduint32(ssh, c->remoteid);
5599 ssh2_pkt_send(ssh);
4ed34d25 5600 }
51470298 5601 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5602 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5603 struct ssh_channel *c;
51470298 5604 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5605 if (!c)
5606 continue; /* nonexistent channel */
5607 if (c->type != CHAN_SOCKDATA_DORMANT)
5608 continue; /* dunno why they're failing this */
5609
5610 logevent("Forwarded connection refused by server");
5611
5612 pfd_close(c->u.pfd.s);
5613
51470298 5614 del234(ssh->channels, c);
724cface 5615 sfree(c);
51470298 5616 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5617 unsigned localid;
5618 char *type;
5619 int typelen, want_reply;
5620 struct ssh_channel *c;
5621
51470298 5622 localid = ssh2_pkt_getuint32(ssh);
5623 ssh2_pkt_getstring(ssh, &type, &typelen);
5624 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5625
5626 /*
5627 * First, check that the channel exists. Otherwise,
5628 * we can instantly disconnect with a rude message.
5629 */
51470298 5630 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5631 if (!c) {
5632 char buf[80];
5633 sprintf(buf, "Received channel request for nonexistent"
5634 " channel %d", localid);
5635 logevent(buf);
51470298 5636 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5637 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5638 ssh2_pkt_addstring(ssh, buf);
5639 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5640 ssh2_pkt_send(ssh);
247308b5 5641 connection_fatal("%s", buf);
51470298 5642 ssh->state = SSH_STATE_CLOSED;
ebb0a590 5643 crReturnV;
5644 }
5645
5646 /*
d8d6c7e5 5647 * Having got the channel number, we now look at
5648 * the request type string to see if it's something
5649 * we recognise.
ebb0a590 5650 */
d8d6c7e5 5651 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5652 c == ssh->mainchan) {
d8d6c7e5 5653 /* We recognise "exit-status" on the primary channel. */
5654 char buf[100];
51470298 5655 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5656 sprintf(buf, "Server sent command exit status %d",
51470298 5657 ssh->exitcode);
d8d6c7e5 5658 logevent(buf);
5659 if (want_reply) {
51470298 5660 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5661 ssh2_pkt_adduint32(ssh, c->remoteid);
5662 ssh2_pkt_send(ssh);
d8d6c7e5 5663 }
5664 } else {
5665 /*
5666 * This is a channel request we don't know
5667 * about, so we now either ignore the request
5668 * or respond with CHANNEL_FAILURE, depending
5669 * on want_reply.
5670 */
5671 if (want_reply) {
51470298 5672 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5673 ssh2_pkt_adduint32(ssh, c->remoteid);
5674 ssh2_pkt_send(ssh);
d8d6c7e5 5675 }
ebb0a590 5676 }
51470298 5677 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5678 char *type;
5679 int typelen, want_reply;
5680
51470298 5681 ssh2_pkt_getstring(ssh, &type, &typelen);
5682 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5683
5684 /*
5685 * We currently don't support any global requests
5686 * at all, so we either ignore the request or
5687 * respond with REQUEST_FAILURE, depending on
5688 * want_reply.
5689 */
5690 if (want_reply) {
51470298 5691 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5692 ssh2_pkt_send(ssh);
697d4856 5693 }
51470298 5694 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5695 char *type;
5696 int typelen;
5697 char *error = NULL;
5698 struct ssh_channel *c;
bc240b21 5699 unsigned remid, winsize, pktsize;
51470298 5700 ssh2_pkt_getstring(ssh, &type, &typelen);
32874aea 5701 c = smalloc(sizeof(struct ssh_channel));
51470298 5702 c->ssh = ssh;
32874aea 5703
51470298 5704 remid = ssh2_pkt_getuint32(ssh);
5705 winsize = ssh2_pkt_getuint32(ssh);
5706 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 5707
32874aea 5708 if (typelen == 3 && !memcmp(type, "x11", 3)) {
51470298 5709 if (!ssh->X11_fwd_enabled)
32874aea 5710 error = "X11 forwarding is not enabled";
302121de 5711 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5712 ssh->x11auth) != NULL) {
32874aea 5713 error = "Unable to open an X11 connection";
5714 } else {
5715 c->type = CHAN_X11;
5716 }
bc240b21 5717 } else if (typelen == 15 &&
5718 !memcmp(type, "forwarded-tcpip", 15)) {
5719 struct ssh_rportfwd pf, *realpf;
5720 char *dummy;
5721 int dummylen;
51470298 5722 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5723 pf.sport = ssh2_pkt_getuint32(ssh);
5724 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 5725 if (realpf == NULL) {
5726 error = "Remote port is not recognised";
5727 } else {
5728 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5729 realpf->dport, c);
5730 char buf[1024];
5731 sprintf(buf, "Received remote port open request for %s:%d",
5732 realpf->dhost, realpf->dport);
5733 logevent(buf);
5734 if (e != NULL) {
5735 sprintf(buf, "Port open failed: %s", e);
5736 logevent(buf);
5737 error = "Port open failed";
5738 } else {
5739 logevent("Forwarded port opened successfully");
5740 c->type = CHAN_SOCKDATA;
5741 }
5742 }
32874aea 5743 } else if (typelen == 22 &&
36c2a3e9 5744 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 5745 if (!ssh->agentfwd_enabled)
32874aea 5746 error = "Agent forwarding is not enabled";
36c2a3e9 5747 else {
32874aea 5748 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5749 c->u.a.lensofar = 0;
32874aea 5750 }
5751 } else {
5752 error = "Unsupported channel type requested";
5753 }
5754
bc240b21 5755 c->remoteid = remid;
32874aea 5756 if (error) {
51470298 5757 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5758 ssh2_pkt_adduint32(ssh, c->remoteid);
5759 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5760 ssh2_pkt_addstring(ssh, error);
5761 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5762 ssh2_pkt_send(ssh);
32874aea 5763 sfree(c);
5764 } else {
51470298 5765 c->localid = alloc_channel_id(ssh);
32874aea 5766 c->closes = 0;
5471d09a 5767 c->v.v2.locwindow = OUR_V2_WINSIZE;
5768 c->v.v2.remwindow = winsize;
5769 c->v.v2.remmaxpkt = pktsize;
5770 bufchain_init(&c->v.v2.outbuffer);
51470298 5771 add234(ssh->channels, c);
5772 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5773 ssh2_pkt_adduint32(ssh, c->remoteid);
5774 ssh2_pkt_adduint32(ssh, c->localid);
5775 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5776 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5777 ssh2_pkt_send(ssh);
32874aea 5778 }
7cca0d81 5779 } else {
51470298 5780 bombout(("Strange packet received: type %d", ssh->pktin.type));
32874aea 5781 crReturnV;
7cca0d81 5782 }
5783 } else {
32874aea 5784 /*
5785 * We have spare data. Add it to the channel buffer.
5786 */
51470298 5787 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5788 s->try_send = TRUE;
32874aea 5789 }
51470298 5790 if (s->try_send) {
32874aea 5791 int i;
5792 struct ssh_channel *c;
5793 /*
5794 * Try to send data on all channels if we can.
5795 */
51470298 5796 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 5797 int bufsize = ssh2_try_send(c);
5798 if (bufsize == 0) {
5799 switch (c->type) {
5800 case CHAN_MAINSESSION:
5801 /* stdin need not receive an unthrottle
5802 * notification since it will be polled */
5803 break;
5804 case CHAN_X11:
5805 x11_unthrottle(c->u.x11.s);
5806 break;
5807 case CHAN_AGENT:
5808 /* agent sockets are request/response and need no
5809 * buffer management */
5810 break;
5811 case CHAN_SOCKDATA:
5812 pfd_unthrottle(c->u.pfd.s);
5813 break;
5814 }
5815 }
5816 }
7cca0d81 5817 }
e5574168 5818 }
5819
5820 crFinishV;
5821}
5822
5823/*
7cca0d81 5824 * Handle the top-level SSH2 protocol.
5825 */
51470298 5826static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 5827{
51470298 5828 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 5829 return;
51470298 5830 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 5831}
5832
5833/*
8df7a775 5834 * Called to set up the connection.
374330e2 5835 *
5836 * Returns an error message, or NULL on success.
374330e2 5837 */
51470298 5838static char *ssh_init(void *frontend_handle, void **backend_handle,
887035a5 5839 char *host, int port, char **realhost, int nodelay)
32874aea 5840{
fb09bf1c 5841 char *p;
51470298 5842 Ssh ssh;
5843
5844 ssh = smalloc(sizeof(*ssh));
5845 ssh->s = NULL;
5846 ssh->cipher = NULL;
371e569c 5847 ssh->v1_cipher_ctx = NULL;
0183b242 5848 ssh->crcda_ctx = NULL;
51470298 5849 ssh->cscipher = NULL;
371e569c 5850 ssh->cs_cipher_ctx = NULL;
51470298 5851 ssh->sccipher = NULL;
371e569c 5852 ssh->sc_cipher_ctx = NULL;
51470298 5853 ssh->csmac = NULL;
e0e1a00d 5854 ssh->sc_mac_ctx = NULL;
51470298 5855 ssh->scmac = NULL;
e0e1a00d 5856 ssh->sc_mac_ctx = NULL;
51470298 5857 ssh->cscomp = NULL;
5366aed8 5858 ssh->cs_comp_ctx = NULL;
51470298 5859 ssh->sccomp = NULL;
5366aed8 5860 ssh->sc_comp_ctx = NULL;
51470298 5861 ssh->kex = NULL;
5862 ssh->hostkey = NULL;
5863 ssh->exitcode = -1;
5864 ssh->state = SSH_STATE_PREPACKET;
5865 ssh->size_needed = FALSE;
5866 ssh->eof_needed = FALSE;
b9d7bcad 5867 ssh->ldisc = NULL;
51470298 5868 {
5869 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5870 ssh->pktin = ssh->pktout = empty;
5871 }
5872 ssh->deferred_send_data = NULL;
5873 ssh->deferred_len = 0;
5874 ssh->deferred_size = 0;
5875 ssh->fallback_cmd = 0;
5876 ssh->pkt_ctx = 0;
302121de 5877 ssh->x11auth = NULL;
51470298 5878 ssh->v2_outgoing_sequence = 0;
5879 ssh->ssh1_rdpkt_crstate = 0;
5880 ssh->ssh2_rdpkt_crstate = 0;
5881 ssh->do_ssh_init_crstate = 0;
5882 ssh->ssh_gotdata_crstate = 0;
5883 ssh->ssh1_protocol_crstate = 0;
5884 ssh->do_ssh1_login_crstate = 0;
5885 ssh->do_ssh2_transport_crstate = 0;
5886 ssh->do_ssh2_authconn_crstate = 0;
5887 ssh->do_ssh_init_state = NULL;
5888 ssh->do_ssh1_login_state = NULL;
5889 ssh->do_ssh2_transport_state = NULL;
5890 ssh->do_ssh2_authconn_state = NULL;
5891
5892 *backend_handle = ssh;
32874aea 5893
8f203108 5894#ifdef MSCRYPTOAPI
32874aea 5895 if (crypto_startup() == 0)
8f203108 5896 return "Microsoft high encryption pack not installed!";
5897#endif
374330e2 5898
51470298 5899 ssh->frontend = frontend_handle;
5900 ssh->term_width = cfg.width;
5901 ssh->term_height = cfg.height;
887035a5 5902
51470298 5903 ssh->send_ok = 0;
5904 ssh->editing = 0;
5905 ssh->echoing = 0;
5906 ssh->v1_throttle_count = 0;
5907 ssh->overall_bufsize = 0;
5908 ssh->fallback_cmd = 0;
8df7a775 5909
51470298 5910 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 5911 if (p != NULL)
5912 return p;
374330e2 5913
374330e2 5914 return NULL;
5915}
5916
5917/*
374330e2 5918 * Called to send data down the Telnet connection.
5919 */
51470298 5920static int ssh_send(void *handle, char *buf, int len)
32874aea 5921{
51470298 5922 Ssh ssh = (Ssh) handle;
5923
5924 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5925 return 0;
374330e2 5926
51470298 5927 ssh->protocol(ssh, buf, len, 0);
5471d09a 5928
51470298 5929 return ssh_sendbuffer(ssh);
5471d09a 5930}
5931
5932/*
5933 * Called to query the current amount of buffered stdin data.
5934 */
51470298 5935static int ssh_sendbuffer(void *handle)
5471d09a 5936{
51470298 5937 Ssh ssh = (Ssh) handle;
5471d09a 5938 int override_value;
5939
51470298 5940 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5941 return 0;
5942
5943 /*
5944 * If the SSH socket itself has backed up, add the total backup
5945 * size on that to any individual buffer on the stdin channel.
5946 */
5947 override_value = 0;
51470298 5948 if (ssh->throttled_all)
5949 override_value = ssh->overall_bufsize;
5471d09a 5950
51470298 5951 if (ssh->version == 1) {
5471d09a 5952 return override_value;
51470298 5953 } else if (ssh->version == 2) {
5954 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 5955 return override_value;
5956 else
51470298 5957 return (override_value +
5958 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 5959 }
5960
5961 return 0;
374330e2 5962}
5963
5964/*
6e48c3fe 5965 * Called to set the size of the window from SSH's POV.
374330e2 5966 */
51470298 5967static void ssh_size(void *handle, int width, int height)
32874aea 5968{
51470298 5969 Ssh ssh = (Ssh) handle;
5970
5971 ssh->term_width = width;
5972 ssh->term_height = height;
f278d6f8 5973
51470298 5974 switch (ssh->state) {
374330e2 5975 case SSH_STATE_BEFORE_SIZE:
3687d221 5976 case SSH_STATE_PREPACKET:
21248260 5977 case SSH_STATE_CLOSED:
374330e2 5978 break; /* do nothing */
5979 case SSH_STATE_INTERMED:
51470298 5980 ssh->size_needed = TRUE; /* buffer for later */
374330e2 5981 break;
5982 case SSH_STATE_SESSION:
32874aea 5983 if (!cfg.nopty) {
51470298 5984 if (ssh->version == 1) {
5985 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
5986 PKT_INT, ssh->term_height,
5987 PKT_INT, ssh->term_width,
32874aea 5988 PKT_INT, 0, PKT_INT, 0, PKT_END);
5989 } else {
51470298 5990 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5991 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5992 ssh2_pkt_addstring(ssh, "window-change");
5993 ssh2_pkt_addbool(ssh, 0);
5994 ssh2_pkt_adduint32(ssh, ssh->term_width);
5995 ssh2_pkt_adduint32(ssh, ssh->term_height);
5996 ssh2_pkt_adduint32(ssh, 0);
5997 ssh2_pkt_adduint32(ssh, 0);
5998 ssh2_pkt_send(ssh);
32874aea 5999 }
6000 }
6001 break;
374330e2 6002 }
6003}
6004
6005/*
6abbf9e3 6006 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6007 * can send an EOF and collect resulting output (e.g. `plink
6008 * hostname sort').
374330e2 6009 */
51470298 6010static void ssh_special(void *handle, Telnet_Special code)
32874aea 6011{
51470298 6012 Ssh ssh = (Ssh) handle;
6013
6abbf9e3 6014 if (code == TS_EOF) {
51470298 6015 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6016 /*
6017 * Buffer the EOF in case we are pre-SESSION, so we can
6018 * send it as soon as we reach SESSION.
6019 */
6020 if (code == TS_EOF)
51470298 6021 ssh->eof_needed = TRUE;
32874aea 6022 return;
6023 }
51470298 6024 if (ssh->version == 1) {
6025 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6026 } else {
51470298 6027 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6028 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6029 ssh2_pkt_send(ssh);
32874aea 6030 }
6031 logevent("Sent EOF message");
ec55b220 6032 } else if (code == TS_PING) {
51470298 6033 if (ssh->state == SSH_STATE_CLOSED
6034 || ssh->state == SSH_STATE_PREPACKET) return;
6035 if (ssh->version == 1) {
6036 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6037 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6038 } else {
51470298 6039 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6040 ssh2_pkt_addstring_start(ssh);
6041 ssh2_pkt_send(ssh);
32874aea 6042 }
6abbf9e3 6043 } else {
32874aea 6044 /* do nothing */
6abbf9e3 6045 }
374330e2 6046}
6047
51470298 6048void *new_sock_channel(void *handle, Socket s)
d74d141c 6049{
51470298 6050 Ssh ssh = (Ssh) handle;
d74d141c 6051 struct ssh_channel *c;
6052 c = smalloc(sizeof(struct ssh_channel));
51470298 6053 c->ssh = ssh;
d74d141c 6054
6055 if (c) {
bc240b21 6056 c->remoteid = -1; /* to be set when open confirmed */
51470298 6057 c->localid = alloc_channel_id(ssh);
d74d141c 6058 c->closes = 0;
bc240b21 6059 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6060 c->u.pfd.s = s;
013dd8c0 6061 bufchain_init(&c->v.v2.outbuffer);
51470298 6062 add234(ssh->channels, c);
d74d141c 6063 }
6064 return c;
6065}
6066
5471d09a 6067/*
6068 * This is called when stdout/stderr (the entity to which
6069 * from_backend sends data) manages to clear some backlog.
6070 */
51470298 6071void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6072{
51470298 6073 Ssh ssh = (Ssh) handle;
6074 if (ssh->version == 1) {
6075 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6076 ssh->v1_stdout_throttling = 0;
6077 ssh1_throttle(ssh, -1);
5471d09a 6078 }
6079 } else {
51470298 6080 if (ssh->mainchan && ssh->mainchan->closes == 0)
6081 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6082 }
6083}
6084
6b78788a 6085void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6086{
6087 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6088 Ssh ssh = c->ssh;
d74d141c 6089 char buf[1024];
6090
6091 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
6092 logevent(buf);
6093
51470298 6094 if (ssh->version == 1) {
6095 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6096 PKT_INT, c->localid,
6097 PKT_STR, hostname,
6098 PKT_INT, port,
6099 //PKT_STR, <org:orgport>,
6100 PKT_END);
6101 } else {
51470298 6102 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6103 ssh2_pkt_addstring(ssh, "direct-tcpip");
6104 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6105 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6106 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6107 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6108 ssh2_pkt_addstring(ssh, hostname);
6109 ssh2_pkt_adduint32(ssh, port);
bc240b21 6110 /*
6111 * We make up values for the originator data; partly it's
6112 * too much hassle to keep track, and partly I'm not
6113 * convinced the server should be told details like that
6114 * about my local network configuration.
6115 */
51470298 6116 ssh2_pkt_addstring(ssh, "client-side-connection");
6117 ssh2_pkt_adduint32(ssh, 0);
6118 ssh2_pkt_send(ssh);
bc240b21 6119 }
d74d141c 6120}
6121
6122
51470298 6123static Socket ssh_socket(void *handle)
32874aea 6124{
51470298 6125 Ssh ssh = (Ssh) handle;
6126 return ssh->s;
32874aea 6127}
8ccc75b0 6128
51470298 6129static int ssh_sendok(void *handle)
32874aea 6130{
51470298 6131 Ssh ssh = (Ssh) handle;
6132 return ssh->send_ok;
32874aea 6133}
fb09bf1c 6134
51470298 6135static int ssh_ldisc(void *handle, int option)
32874aea 6136{
51470298 6137 Ssh ssh = (Ssh) handle;
32874aea 6138 if (option == LD_ECHO)
51470298 6139 return ssh->echoing;
32874aea 6140 if (option == LD_EDIT)
51470298 6141 return ssh->editing;
0965bee0 6142 return FALSE;
6143}
6144
b9d7bcad 6145static void ssh_provide_ldisc(void *handle, void *ldisc)
6146{
6147 Ssh ssh = (Ssh) handle;
6148 ssh->ldisc = ldisc;
6149}
6150
51470298 6151static int ssh_return_exitcode(void *handle)
6152{
6153 Ssh ssh = (Ssh) handle;
6154 return ssh->exitcode;
6155}
6156
6157/*
6158 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6159 * that fails. This variable is the means by which scp.c can reach
6160 * into the SSH code and find out which one it got.
6161 */
6162extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6163{
51470298 6164 Ssh ssh = (Ssh) handle;
6165 return ssh->fallback_cmd;
d8d6c7e5 6166}
6167
374330e2 6168Backend ssh_backend = {
6169 ssh_init,
374330e2 6170 ssh_send,
5471d09a 6171 ssh_sendbuffer,
374330e2 6172 ssh_size,
4017be6d 6173 ssh_special,
8ccc75b0 6174 ssh_socket,
d8d6c7e5 6175 ssh_return_exitcode,
97db3be4 6176 ssh_sendok,
0965bee0 6177 ssh_ldisc,
b9d7bcad 6178 ssh_provide_ldisc,
5471d09a 6179 ssh_unthrottle,
97db3be4 6180 22
bc240b21 6181};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator