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Try actually initialising ssh->v1_compressing. With any luck this
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
107#define SSH2_PKTCTX_DHGROUP1 0x0001
108#define SSH2_PKTCTX_DHGEX 0x0002
109#define SSH2_PKTCTX_PUBLICKEY 0x0010
110#define SSH2_PKTCTX_PASSWORD 0x0020
111#define SSH2_PKTCTX_KBDINTER 0x0040
112#define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
32874aea 114#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147};
9005f3ba 148
32874aea 149#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
8e975795 165#define BUG_SSH2_DH_GEX 64
bd358db1 166
00db133f 167#define translate(x) if (type == x) return #x
51470298 168#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
00db133f 169char *ssh1_pkt_type(int type)
170{
171 translate(SSH1_MSG_DISCONNECT);
172 translate(SSH1_SMSG_PUBLIC_KEY);
173 translate(SSH1_CMSG_SESSION_KEY);
174 translate(SSH1_CMSG_USER);
175 translate(SSH1_CMSG_AUTH_RSA);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
178 translate(SSH1_CMSG_AUTH_PASSWORD);
179 translate(SSH1_CMSG_REQUEST_PTY);
180 translate(SSH1_CMSG_WINDOW_SIZE);
181 translate(SSH1_CMSG_EXEC_SHELL);
182 translate(SSH1_CMSG_EXEC_CMD);
183 translate(SSH1_SMSG_SUCCESS);
184 translate(SSH1_SMSG_FAILURE);
185 translate(SSH1_CMSG_STDIN_DATA);
186 translate(SSH1_SMSG_STDOUT_DATA);
187 translate(SSH1_SMSG_STDERR_DATA);
188 translate(SSH1_CMSG_EOF);
189 translate(SSH1_SMSG_EXIT_STATUS);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
192 translate(SSH1_MSG_CHANNEL_DATA);
193 translate(SSH1_MSG_CHANNEL_CLOSE);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
195 translate(SSH1_SMSG_X11_OPEN);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
197 translate(SSH1_MSG_PORT_OPEN);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
199 translate(SSH1_SMSG_AGENT_OPEN);
200 translate(SSH1_MSG_IGNORE);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
204 translate(SSH1_MSG_DEBUG);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION);
206 translate(SSH1_CMSG_AUTH_TIS);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
209 translate(SSH1_CMSG_AUTH_CCARD);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
212 return "unknown";
213}
51470298 214char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 215{
216 translate(SSH2_MSG_DISCONNECT);
217 translate(SSH2_MSG_IGNORE);
218 translate(SSH2_MSG_UNIMPLEMENTED);
219 translate(SSH2_MSG_DEBUG);
220 translate(SSH2_MSG_SERVICE_REQUEST);
221 translate(SSH2_MSG_SERVICE_ACCEPT);
222 translate(SSH2_MSG_KEXINIT);
223 translate(SSH2_MSG_NEWKEYS);
224 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
225 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
230 translate(SSH2_MSG_USERAUTH_REQUEST);
231 translate(SSH2_MSG_USERAUTH_FAILURE);
232 translate(SSH2_MSG_USERAUTH_SUCCESS);
233 translate(SSH2_MSG_USERAUTH_BANNER);
234 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
238 translate(SSH2_MSG_GLOBAL_REQUEST);
239 translate(SSH2_MSG_REQUEST_SUCCESS);
240 translate(SSH2_MSG_REQUEST_FAILURE);
241 translate(SSH2_MSG_CHANNEL_OPEN);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
245 translate(SSH2_MSG_CHANNEL_DATA);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
247 translate(SSH2_MSG_CHANNEL_EOF);
248 translate(SSH2_MSG_CHANNEL_CLOSE);
249 translate(SSH2_MSG_CHANNEL_REQUEST);
250 translate(SSH2_MSG_CHANNEL_SUCCESS);
251 translate(SSH2_MSG_CHANNEL_FAILURE);
252 return "unknown";
253}
254#undef translate
255#undef translatec
7d503c31 256
fb09bf1c 257#define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
262
263#define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
268
7cca0d81 269enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 270
374330e2 271/* Coroutine mechanics for the sillier bits of the code */
51470298 272#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
273#define crState(t) \
274 struct t *s; \
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
276 s = ssh->t;
277#define crFinish(z) } *crLine = 0; return (z); }
278#define crFinishV } *crLine = 0; return; }
374330e2 279#define crReturn(z) \
280 do {\
51470298 281 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 282 } while (0)
283#define crReturnV \
284 do {\
51470298 285 *crLine=__LINE__; return; case __LINE__:;\
374330e2 286 } while (0)
51470298 287#define crStop(z) do{ *crLine = 0; return (z); }while(0)
288#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 289#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 290#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 291
51470298 292typedef struct ssh_tag *Ssh;
293
302121de 294extern char *x11_init(Socket *, char *, void *, void *);
32874aea 295extern void x11_close(Socket);
5471d09a 296extern int x11_send(Socket, char *, int);
302121de 297extern void *x11_invent_auth(char *, int, char *, int);
5471d09a 298extern void x11_unthrottle(Socket s);
299extern void x11_override_throttle(Socket s, int enable);
9c964e85 300
d74d141c 301extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
6b78788a 302extern char *pfd_addforward(char *desthost, int destport, int port,
303 void *backhandle);
d74d141c 304extern void pfd_close(Socket s);
5471d09a 305extern int pfd_send(Socket s, char *data, int len);
d74d141c 306extern void pfd_confirm(Socket s);
5471d09a 307extern void pfd_unthrottle(Socket s);
308extern void pfd_override_throttle(Socket s, int enable);
309
51470298 310static void ssh2_pkt_init(Ssh, int pkt_type);
311static void ssh2_pkt_addbool(Ssh, unsigned char value);
312static void ssh2_pkt_adduint32(Ssh, unsigned long value);
313static void ssh2_pkt_addstring_start(Ssh);
314static void ssh2_pkt_addstring_str(Ssh, char *data);
315static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
316static void ssh2_pkt_addstring(Ssh, char *data);
3d63ca2e 317static char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 318static void ssh2_pkt_addmp(Ssh, Bignum b);
319static int ssh2_pkt_construct(Ssh);
320static void ssh2_pkt_send(Ssh);
3d63ca2e 321
5471d09a 322/*
323 * Buffer management constants. There are several of these for
324 * various different purposes:
325 *
326 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
327 * on a local data stream before we throttle the whole SSH
328 * connection (in SSH1 only). Throttling the whole connection is
329 * pretty drastic so we set this high in the hope it won't
330 * happen very often.
331 *
332 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
333 * on the SSH connection itself before we defensively throttle
334 * _all_ local data streams. This is pretty drastic too (though
335 * thankfully unlikely in SSH2 since the window mechanism should
336 * ensure that the server never has any need to throttle its end
337 * of the connection), so we set this high as well.
338 *
339 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
340 * channels.
341 */
342
343#define SSH1_BUFFER_LIMIT 32768
344#define SSH_MAX_BACKLOG 32768
345#define OUR_V2_WINSIZE 16384
d74d141c 346
a92dd380 347const static struct ssh_kex *kex_algs[] = {
a92dd380 348 &ssh_diffiehellman_gex,
32874aea 349 &ssh_diffiehellman
350};
e5574168 351
85cc02bb 352const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 353
e0e1a00d 354static void *nullmac_make_context(void)
355{
356 return NULL;
357}
358static void nullmac_free_context(void *handle)
359{
360}
361static void nullmac_key(void *handle, unsigned char *key)
32874aea 362{
363}
e0e1a00d 364static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 365 unsigned long seq)
366{
367}
e0e1a00d 368static int nullmac_verify(void *handle, unsigned char *blk, int len,
369 unsigned long seq)
32874aea 370{
371 return 1;
372}
57476f6b 373const static struct ssh_mac ssh_mac_none = {
e0e1a00d 374 nullmac_make_context, nullmac_free_context, nullmac_key,
375 nullmac_generate, nullmac_verify, "none", 0
e5574168 376};
8b2715b2 377const static struct ssh_mac *macs[] = {
32874aea 378 &ssh_sha1, &ssh_md5, &ssh_mac_none
379};
8b2715b2 380const static struct ssh_mac *buggymacs[] = {
32874aea 381 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
382};
e5574168 383
5366aed8 384static void *ssh_comp_none_init(void)
385{
386 return NULL;
387}
388static void ssh_comp_none_cleanup(void *handle)
32874aea 389{
390}
5366aed8 391static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 392 unsigned char **outblock, int *outlen)
393{
394 return 0;
395}
5366aed8 396static int ssh_comp_none_disable(void *handle)
32874aea 397{
4ba9b64b 398 return 0;
399}
57476f6b 400const static struct ssh_compress ssh_comp_none = {
4ba9b64b 401 "none",
5366aed8 402 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
403 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
404 ssh_comp_none_disable, NULL
e5574168 405};
4ba9b64b 406extern const struct ssh_compress ssh_zlib;
407const static struct ssh_compress *compressions[] = {
32874aea 408 &ssh_zlib, &ssh_comp_none
409};
374330e2 410
32874aea 411enum { /* channel types */
783415f8 412 CHAN_MAINSESSION,
413 CHAN_X11,
414 CHAN_AGENT,
bc240b21 415 CHAN_SOCKDATA,
416 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 417};
418
dacbd0e8 419/*
420 * 2-3-4 tree storing channels.
421 */
422struct ssh_channel {
51470298 423 Ssh ssh; /* pointer back to main context */
d211621f 424 unsigned remoteid, localid;
dacbd0e8 425 int type;
0357890f 426 /*
427 * In SSH1, this value contains four bits:
428 *
429 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
430 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
431 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
432 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
433 *
434 * A channel is completely finished with when all four bits are set.
435 */
dacbd0e8 436 int closes;
5471d09a 437 union {
438 struct ssh1_data_channel {
439 int throttling;
440 } v1;
441 struct ssh2_data_channel {
442 bufchain outbuffer;
443 unsigned remwindow, remmaxpkt;
444 unsigned locwindow;
445 } v2;
446 } v;
dacbd0e8 447 union {
32874aea 448 struct ssh_agent_channel {
449 unsigned char *message;
450 unsigned char msglen[4];
451 int lensofar, totallen;
452 } a;
453 struct ssh_x11_channel {
454 Socket s;
455 } x11;
d74d141c 456 struct ssh_pfd_channel {
457 Socket s;
458 } pfd;
dacbd0e8 459 } u;
460};
57476f6b 461
d74d141c 462/*
bc240b21 463 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
464 * 2 use this structure in different ways, reflecting SSH 2's
465 * altogether saner approach to port forwarding.
466 *
467 * In SSH 1, you arrange a remote forwarding by sending the server
468 * the remote port number, and the local destination host:port.
469 * When a connection comes in, the server sends you back that
470 * host:port pair, and you connect to it. This is a ready-made
471 * security hole if you're not on the ball: a malicious server
472 * could send you back _any_ host:port pair, so if you trustingly
473 * connect to the address it gives you then you've just opened the
474 * entire inside of your corporate network just by connecting
475 * through it to a dodgy SSH server. Hence, we must store a list of
476 * host:port pairs we _are_ trying to forward to, and reject a
477 * connection request from the server if it's not in the list.
478 *
479 * In SSH 2, each side of the connection minds its own business and
480 * doesn't send unnecessary information to the other. You arrange a
481 * remote forwarding by sending the server just the remote port
482 * number. When a connection comes in, the server tells you which
483 * of its ports was connected to; and _you_ have to remember what
484 * local host:port pair went with that port number.
485 *
486 * Hence: in SSH 1 this structure stores host:port pairs we intend
487 * to allow connections to, and is indexed by those host:port
488 * pairs. In SSH 2 it stores a mapping from source port to
489 * destination host:port pair, and is indexed by source port.
d74d141c 490 */
491struct ssh_rportfwd {
bc240b21 492 unsigned sport, dport;
493 char dhost[256];
d74d141c 494};
495
57476f6b 496struct Packet {
497 long length;
498 int type;
499 unsigned char *data;
500 unsigned char *body;
501 long savedpos;
502 long maxlen;
503};
504
51470298 505static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
506static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
507static void ssh_size(void *handle, int width, int height);
508static void ssh_special(void *handle, Telnet_Special);
5471d09a 509static int ssh2_try_send(struct ssh_channel *c);
51470298 510static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
511static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 512static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 513static int ssh_sendbuffer(void *handle);
57476f6b 514
51470298 515struct rdpkt1_state_tag {
57476f6b 516 long len, pad, biglen, to_read;
517 unsigned long realcrc, gotcrc;
518 unsigned char *p;
519 int i;
520 int chunk;
51470298 521};
57476f6b 522
51470298 523struct rdpkt2_state_tag {
960e736a 524 long len, pad, payload, packetlen, maclen;
525 int i;
526 int cipherblk;
527 unsigned long incoming_sequence;
51470298 528};
529
530struct ssh_tag {
531 const struct plug_function_table *fn;
532 /* the above field _must_ be first in the structure */
533
534 SHA_State exhash, exhashbase;
535
536 Socket s;
537
b9d7bcad 538 void *ldisc;
a8327734 539 void *logctx;
b9d7bcad 540
51470298 541 unsigned char session_key[32];
542 int v1_compressing;
543 int v1_remote_protoflags;
544 int v1_local_protoflags;
545 int agentfwd_enabled;
546 int X11_fwd_enabled;
547 int remote_bugs;
548 const struct ssh_cipher *cipher;
371e569c 549 void *v1_cipher_ctx;
0183b242 550 void *crcda_ctx;
51470298 551 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 552 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 553 const struct ssh_mac *csmac, *scmac;
e0e1a00d 554 void *cs_mac_ctx, *sc_mac_ctx;
51470298 555 const struct ssh_compress *cscomp, *sccomp;
5366aed8 556 void *cs_comp_ctx, *sc_comp_ctx;
51470298 557 const struct ssh_kex *kex;
558 const struct ssh_signkey *hostkey;
559 unsigned char v2_session_id[20];
27cd7fc2 560 void *kex_ctx;
51470298 561
562 char *savedhost;
563 int savedport;
564 int send_ok;
565 int echoing, editing;
566
567 void *frontend;
568
569 int term_width, term_height;
570
571 tree234 *channels; /* indexed by local id */
572 struct ssh_channel *mainchan; /* primary session channel */
573 int exitcode;
574
575 tree234 *rportfwds;
576
577 enum {
578 SSH_STATE_PREPACKET,
579 SSH_STATE_BEFORE_SIZE,
580 SSH_STATE_INTERMED,
581 SSH_STATE_SESSION,
582 SSH_STATE_CLOSED
583 } state;
584
585 int size_needed, eof_needed;
586
587 struct Packet pktin;
588 struct Packet pktout;
589 unsigned char *deferred_send_data;
590 int deferred_len, deferred_size;
591
592 /*
593 * Gross hack: pscp will try to start SFTP but fall back to
594 * scp1 if that fails. This variable is the means by which
595 * scp.c can reach into the SSH code and find out which one it
596 * got.
597 */
598 int fallback_cmd;
599
600 /*
601 * Used for username and password input.
602 */
603 char *userpass_input_buffer;
604 int userpass_input_buflen;
605 int userpass_input_bufpos;
606 int userpass_input_echo;
607
608 char *portfwd_strptr;
609 int pkt_ctx;
610
302121de 611 void *x11auth;
612
51470298 613 int version;
614 int v1_throttle_count;
615 int overall_bufsize;
616 int throttled_all;
617 int v1_stdout_throttling;
618 int v2_outgoing_sequence;
619
620 int ssh1_rdpkt_crstate;
621 int ssh2_rdpkt_crstate;
622 int do_ssh_init_crstate;
623 int ssh_gotdata_crstate;
624 int ssh1_protocol_crstate;
625 int do_ssh1_login_crstate;
626 int do_ssh2_transport_crstate;
627 int do_ssh2_authconn_crstate;
628
629 void *do_ssh_init_state;
630 void *do_ssh1_login_state;
631 void *do_ssh2_transport_state;
632 void *do_ssh2_authconn_state;
633
634 struct rdpkt1_state_tag rdpkt1_state;
635 struct rdpkt2_state_tag rdpkt2_state;
636
637 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
638 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
639};
960e736a 640
a8327734 641#define logevent(s) { logevent(ssh->frontend, s); \
642 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
643 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
644
645/* logevent, only printf-formatted. */
646void logeventf(Ssh ssh, char *fmt, ...)
647{
648 va_list ap;
649 char stuff[200];
650
651 va_start(ap, fmt);
652 vsprintf(stuff, fmt, ap);
653 va_end(ap);
654 logevent(stuff);
655}
656
657#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
658 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
659 logeventf msg, connection_fatal msg )
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)) {
a8327734 826 bombout((ssh,"Network attack (CRC compensation) detected!"));
9a3a93a5 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) {
a8327734 836 bombout((ssh,"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
a8327734 863 if (ssh->logctx)
864 log_packet(ssh->logctx,
865 PKT_INCOMING, ssh->pktin.type,
866 ssh1_pkt_type(ssh->pktin.type),
867 ssh->pktin.body, ssh->pktin.length);
00db133f 868
51470298 869 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
870 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
871 ssh->pktin.type == SSH1_MSG_DEBUG ||
872 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
873 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
874 long stringlen = GET_32BIT(ssh->pktin.body);
875 if (stringlen + 4 != ssh->pktin.length) {
a8327734 876 bombout((ssh,"Received data packet with bogus string length"));
32874aea 877 crReturn(0);
878 }
fb09bf1c 879 }
880
51470298 881 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 882 /* log debug message */
eb4504cc 883 char buf[512];
51470298 884 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 885 strcpy(buf, "Remote debug message: ");
886 if (stringlen > 480)
887 stringlen = 480;
51470298 888 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 889 buf[8 + stringlen] = '\0';
fb09bf1c 890 logevent(buf);
891 goto next_packet;
51470298 892 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 893 /* do nothing */
894 goto next_packet;
895 }
896
51470298 897 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 898 /* log reason code in disconnect message */
899 char buf[256];
51470298 900 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 901 unsigned nowlen;
38c4a8da 902 strcpy(buf, "Remote sent disconnect: ");
903 nowlen = strlen(buf);
32874aea 904 if (msglen > sizeof(buf) - nowlen - 1)
905 msglen = sizeof(buf) - nowlen - 1;
51470298 906 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 907 buf[nowlen + msglen] = '\0';
247308b5 908 /* logevent(buf); (this is now done within the bombout macro) */
a8327734 909 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 910 crReturn(0);
38c4a8da 911 }
912
fb09bf1c 913 crFinish(0);
914}
915
51470298 916static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 917{
51470298 918 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 919
51470298 920 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 921
32874aea 922 next_packet:
51470298 923 ssh->pktin.type = 0;
924 ssh->pktin.length = 0;
925 if (ssh->sccipher)
926 st->cipherblk = ssh->sccipher->blksize;
e5574168 927 else
32874aea 928 st->cipherblk = 8;
960e736a 929 if (st->cipherblk < 8)
32874aea 930 st->cipherblk = 8;
960e736a 931
51470298 932 if (ssh->pktin.maxlen < st->cipherblk) {
933 ssh->pktin.maxlen = st->cipherblk;
934 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
e5574168 935 }
936
937 /*
938 * Acquire and decrypt the first block of the packet. This will
939 * contain the length and padding details.
940 */
32874aea 941 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 942 while ((*datalen) == 0)
32874aea 943 crReturn(st->cipherblk - st->i);
51470298 944 ssh->pktin.data[st->i] = *(*data)++;
32874aea 945 (*datalen)--;
e5574168 946 }
4252c9cc 947
51470298 948 if (ssh->sccipher)
371e569c 949 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
950 ssh->pktin.data, st->cipherblk);
e5574168 951
952 /*
953 * Now get the length and padding figures.
954 */
51470298 955 st->len = GET_32BIT(ssh->pktin.data);
956 st->pad = ssh->pktin.data[4];
e5574168 957
958 /*
717dc483 959 * _Completely_ silly lengths should be stomped on before they
960 * do us any more damage.
961 */
962 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
a8327734 963 bombout((ssh,"Incoming packet was garbled on decryption"));
717dc483 964 crReturn(0);
965 }
966
967 /*
e5574168 968 * This enables us to deduce the payload length.
969 */
960e736a 970 st->payload = st->len - st->pad - 1;
e5574168 971
51470298 972 ssh->pktin.length = st->payload + 5;
e5574168 973
974 /*
975 * So now we can work out the total packet length.
976 */
960e736a 977 st->packetlen = st->len + 4;
51470298 978 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 979
980 /*
981 * Adjust memory allocation if packet is too big.
982 */
51470298 983 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
984 ssh->pktin.maxlen = st->packetlen + st->maclen;
985 ssh->pktin.data = srealloc(ssh->pktin.data,
986 ssh->pktin.maxlen + APIEXTRA);
e5574168 987 }
988
989 /*
990 * Read and decrypt the remainder of the packet.
991 */
32874aea 992 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
993 st->i++) {
e5574168 994 while ((*datalen) == 0)
960e736a 995 crReturn(st->packetlen + st->maclen - st->i);
51470298 996 ssh->pktin.data[st->i] = *(*data)++;
32874aea 997 (*datalen)--;
e5574168 998 }
999 /* Decrypt everything _except_ the MAC. */
51470298 1000 if (ssh->sccipher)
371e569c 1001 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1002 ssh->pktin.data + st->cipherblk,
51470298 1003 st->packetlen - st->cipherblk);
e5574168 1004
1005 /*
1006 * Check the MAC.
1007 */
51470298 1008 if (ssh->scmac
e0e1a00d 1009 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1010 st->incoming_sequence)) {
a8327734 1011 bombout((ssh,"Incorrect MAC received on packet"));
32874aea 1012 crReturn(0);
8d5de777 1013 }
32874aea 1014 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1015
4ba9b64b 1016 /*
1017 * Decompress packet payload.
1018 */
1019 {
1020 unsigned char *newpayload;
1021 int newlen;
51470298 1022 if (ssh->sccomp &&
5366aed8 1023 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1024 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1025 &newpayload, &newlen)) {
1026 if (ssh->pktin.maxlen < newlen + 5) {
1027 ssh->pktin.maxlen = newlen + 5;
1028 ssh->pktin.data = srealloc(ssh->pktin.data,
1029 ssh->pktin.maxlen + APIEXTRA);
4ba9b64b 1030 }
51470298 1031 ssh->pktin.length = 5 + newlen;
1032 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1033 sfree(newpayload);
4ba9b64b 1034 }
1035 }
1036
51470298 1037 ssh->pktin.savedpos = 6;
1038 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1039
a8327734 1040 if (ssh->logctx)
1041 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1042 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1043 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1044
51470298 1045 switch (ssh->pktin.type) {
3d63ca2e 1046 /*
1047 * These packets we must handle instantly.
1048 */
1049 case SSH2_MSG_DISCONNECT:
1050 {
1051 /* log reason code in disconnect message */
1052 char buf[256];
51470298 1053 int reason = GET_32BIT(ssh->pktin.data + 6);
1054 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
3d63ca2e 1055 unsigned nowlen;
1056 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1057 sprintf(buf, "Received disconnect message (%s)",
1058 ssh2_disconnect_reasons[reason]);
1059 } else {
1060 sprintf(buf, "Received disconnect message (unknown type %d)",
1061 reason);
1062 }
1063 logevent(buf);
1064 strcpy(buf, "Disconnection message text: ");
1065 nowlen = strlen(buf);
1066 if (msglen > sizeof(buf) - nowlen - 1)
1067 msglen = sizeof(buf) - nowlen - 1;
51470298 1068 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
3d63ca2e 1069 buf[nowlen + msglen] = '\0';
1070 logevent(buf);
a8327734 1071 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1072 reason,
1073 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1074 ssh2_disconnect_reasons[reason] : "unknown",
1075 buf+nowlen));
1076 crReturn(0);
1077 }
1078 break;
1079 case SSH2_MSG_IGNORE:
1080 goto next_packet;
1081 case SSH2_MSG_DEBUG:
1082 {
1083 /* log the debug message */
1084 char buf[512];
51470298 1085 /* int display = ssh->pktin.body[6]; */
1086 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1087 int prefix;
1088 strcpy(buf, "Remote debug message: ");
1089 prefix = strlen(buf);
51470298 1090 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1091 stringlen = sizeof(buf)-prefix-1;
51470298 1092 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1093 buf[prefix + stringlen] = '\0';
1094 logevent(buf);
38c4a8da 1095 }
3d63ca2e 1096 goto next_packet; /* FIXME: print the debug message */
1097
1098 /*
1099 * These packets we need do nothing about here.
1100 */
1101 case SSH2_MSG_UNIMPLEMENTED:
1102 case SSH2_MSG_SERVICE_REQUEST:
1103 case SSH2_MSG_SERVICE_ACCEPT:
1104 case SSH2_MSG_KEXINIT:
1105 case SSH2_MSG_NEWKEYS:
1106 case SSH2_MSG_KEXDH_INIT:
1107 case SSH2_MSG_KEXDH_REPLY:
1108 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1109 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1110 case SSH2_MSG_KEX_DH_GEX_INIT:
1111 case SSH2_MSG_KEX_DH_GEX_REPLY:
1112 case SSH2_MSG_USERAUTH_REQUEST:
1113 case SSH2_MSG_USERAUTH_FAILURE:
1114 case SSH2_MSG_USERAUTH_SUCCESS:
1115 case SSH2_MSG_USERAUTH_BANNER:
1116 case SSH2_MSG_USERAUTH_PK_OK:
1117 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1118 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1119 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1120 case SSH2_MSG_GLOBAL_REQUEST:
1121 case SSH2_MSG_REQUEST_SUCCESS:
1122 case SSH2_MSG_REQUEST_FAILURE:
1123 case SSH2_MSG_CHANNEL_OPEN:
1124 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1125 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1126 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1127 case SSH2_MSG_CHANNEL_DATA:
1128 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1129 case SSH2_MSG_CHANNEL_EOF:
1130 case SSH2_MSG_CHANNEL_CLOSE:
1131 case SSH2_MSG_CHANNEL_REQUEST:
1132 case SSH2_MSG_CHANNEL_SUCCESS:
1133 case SSH2_MSG_CHANNEL_FAILURE:
1134 break;
1135
1136 /*
1137 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1138 */
1139 default:
51470298 1140 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1141 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1142 ssh2_pkt_send(ssh);
3d63ca2e 1143 break;
38c4a8da 1144 }
1145
e5574168 1146 crFinish(0);
1147}
1148
51470298 1149static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1150{
374330e2 1151 int pad, biglen;
1152
1153 len += 5; /* type and CRC */
32874aea 1154 pad = 8 - (len % 8);
374330e2 1155 biglen = len + pad;
1156
51470298 1157 ssh->pktout.length = len - 5;
1158 if (ssh->pktout.maxlen < biglen) {
1159 ssh->pktout.maxlen = biglen;
8f203108 1160#ifdef MSCRYPTOAPI
fb09bf1c 1161 /* Allocate enough buffer space for extra block
8f203108 1162 * for MS CryptEncrypt() */
51470298 1163 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
8f203108 1164#else
51470298 1165 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
8f203108 1166#endif
374330e2 1167 }
51470298 1168 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1169}
374330e2 1170
51470298 1171static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1172{
51470298 1173 ssh1_pktout_size(ssh, len);
1174 ssh->pktout.type = type;
374330e2 1175}
1176
51470298 1177static int s_wrpkt_prepare(Ssh ssh)
32874aea 1178{
374330e2 1179 int pad, len, biglen, i;
1180 unsigned long crc;
1181
51470298 1182 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1183
a8327734 1184 if (ssh->logctx)
1185 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1186 ssh1_pkt_type(ssh->pktout.type),
1187 ssh->pktout.body, ssh->pktout.length);
00db133f 1188
51470298 1189 if (ssh->v1_compressing) {
4ba9b64b 1190 unsigned char *compblk;
1191 int complen;
5366aed8 1192 zlib_compress_block(ssh->cs_comp_ctx,
1193 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1194 &compblk, &complen);
51470298 1195 ssh1_pktout_size(ssh, complen - 1);
1196 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1197 sfree(compblk);
4ba9b64b 1198 }
1199
51470298 1200 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1201 pad = 8 - (len % 8);
374330e2 1202 biglen = len + pad;
1203
32874aea 1204 for (i = 0; i < pad; i++)
51470298 1205 ssh->pktout.data[i + 4] = random_byte();
1206 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1207 PUT_32BIT(ssh->pktout.data + biglen, crc);
1208 PUT_32BIT(ssh->pktout.data, len);
374330e2 1209
51470298 1210 if (ssh->cipher)
371e569c 1211 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1212
32874aea 1213 return biglen + 4;
39065bed 1214}
1215
51470298 1216static void s_wrpkt(Ssh ssh)
32874aea 1217{
5471d09a 1218 int len, backlog;
51470298 1219 len = s_wrpkt_prepare(ssh);
1220 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1221 if (backlog > SSH_MAX_BACKLOG)
51470298 1222 ssh_throttle_all(ssh, 1, backlog);
39065bed 1223}
1224
51470298 1225static void s_wrpkt_defer(Ssh ssh)
32874aea 1226{
39065bed 1227 int len;
51470298 1228 len = s_wrpkt_prepare(ssh);
1229 if (ssh->deferred_len + len > ssh->deferred_size) {
1230 ssh->deferred_size = ssh->deferred_len + len + 128;
1231 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1232 ssh->deferred_size);
39065bed 1233 }
51470298 1234 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1235 ssh->deferred_len += len;
374330e2 1236}
1237
fb09bf1c 1238/*
39065bed 1239 * Construct a packet with the specified contents.
fb09bf1c 1240 */
51470298 1241static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1242{
fb09bf1c 1243 unsigned char *p, *argp, argchar;
1244 unsigned long argint;
1245 int pktlen, argtype, arglen;
7cca0d81 1246 Bignum bn;
fb09bf1c 1247
1248 pktlen = 0;
39065bed 1249 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1250 switch (argtype) {
1251 case PKT_INT:
39065bed 1252 (void) va_arg(ap1, int);
fb09bf1c 1253 pktlen += 4;
1254 break;
1255 case PKT_CHAR:
39065bed 1256 (void) va_arg(ap1, char);
fb09bf1c 1257 pktlen++;
1258 break;
1259 case PKT_DATA:
39065bed 1260 (void) va_arg(ap1, unsigned char *);
1261 arglen = va_arg(ap1, int);
fb09bf1c 1262 pktlen += arglen;
1263 break;
1264 case PKT_STR:
39065bed 1265 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1266 arglen = strlen(argp);
1267 pktlen += 4 + arglen;
1268 break;
7cca0d81 1269 case PKT_BIGNUM:
39065bed 1270 bn = va_arg(ap1, Bignum);
32874aea 1271 pktlen += ssh1_bignum_length(bn);
7cca0d81 1272 break;
fb09bf1c 1273 default:
1274 assert(0);
1275 }
1276 }
fb09bf1c 1277
51470298 1278 s_wrpkt_start(ssh, pkttype, pktlen);
1279 p = ssh->pktout.body;
fb09bf1c 1280
39065bed 1281 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1282 switch (argtype) {
1283 case PKT_INT:
39065bed 1284 argint = va_arg(ap2, int);
fb09bf1c 1285 PUT_32BIT(p, argint);
1286 p += 4;
1287 break;
1288 case PKT_CHAR:
39065bed 1289 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1290 *p = argchar;
1291 p++;
1292 break;
1293 case PKT_DATA:
39065bed 1294 argp = va_arg(ap2, unsigned char *);
1295 arglen = va_arg(ap2, int);
fb09bf1c 1296 memcpy(p, argp, arglen);
1297 p += arglen;
1298 break;
1299 case PKT_STR:
39065bed 1300 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1301 arglen = strlen(argp);
1302 PUT_32BIT(p, arglen);
1303 memcpy(p + 4, argp, arglen);
1304 p += 4 + arglen;
1305 break;
7cca0d81 1306 case PKT_BIGNUM:
39065bed 1307 bn = va_arg(ap2, Bignum);
32874aea 1308 p += ssh1_write_bignum(p, bn);
7cca0d81 1309 break;
fb09bf1c 1310 }
1311 }
39065bed 1312}
fb09bf1c 1313
51470298 1314static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1315{
39065bed 1316 va_list ap1, ap2;
1317 va_start(ap1, pkttype);
1318 va_start(ap2, pkttype);
51470298 1319 construct_packet(ssh, pkttype, ap1, ap2);
1320 s_wrpkt(ssh);
fb09bf1c 1321}
1322
51470298 1323static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1324{
39065bed 1325 va_list ap1, ap2;
1326 va_start(ap1, pkttype);
1327 va_start(ap2, pkttype);
51470298 1328 construct_packet(ssh, pkttype, ap1, ap2);
1329 s_wrpkt_defer(ssh);
39065bed 1330}
1331
32874aea 1332static int ssh_versioncmp(char *a, char *b)
1333{
9697bfd2 1334 char *ae, *be;
1335 unsigned long av, bv;
1336
43aa02a7 1337 av = strtoul(a, &ae, 10);
1338 bv = strtoul(b, &be, 10);
32874aea 1339 if (av != bv)
1340 return (av < bv ? -1 : +1);
1341 if (*ae == '.')
1342 ae++;
1343 if (*be == '.')
1344 be++;
43aa02a7 1345 av = strtoul(ae, &ae, 10);
1346 bv = strtoul(be, &be, 10);
32874aea 1347 if (av != bv)
1348 return (av < bv ? -1 : +1);
9697bfd2 1349 return 0;
1350}
1351
e5574168 1352/*
a92dd380 1353 * Utility routines for putting an SSH-protocol `string' and
1354 * `uint32' into a SHA state.
e5574168 1355 */
1356#include <stdio.h>
32874aea 1357static void sha_string(SHA_State * s, void *str, int len)
1358{
e5574168 1359 unsigned char lenblk[4];
e5574168 1360 PUT_32BIT(lenblk, len);
e5574168 1361 SHA_Bytes(s, lenblk, 4);
e5574168 1362 SHA_Bytes(s, str, len);
1363}
1364
32874aea 1365static void sha_uint32(SHA_State * s, unsigned i)
1366{
a92dd380 1367 unsigned char intblk[4];
1368 PUT_32BIT(intblk, i);
1369 SHA_Bytes(s, intblk, 4);
1370}
1371
7cca0d81 1372/*
1373 * SSH2 packet construction functions.
1374 */
51470298 1375static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1376{
51470298 1377 if (ssh->pktout.maxlen < length) {
1378 ssh->pktout.maxlen = length + 256;
1379 ssh->pktout.data = srealloc(ssh->pktout.data,
1380 ssh->pktout.maxlen + APIEXTRA);
1381 if (!ssh->pktout.data)
32874aea 1382 fatalbox("Out of memory");
7cca0d81 1383 }
783415f8 1384}
51470298 1385static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1386{
51470298 1387 ssh->pktout.length += len;
1388 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1389 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1390}
51470298 1391static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1392{
51470298 1393 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1394}
51470298 1395static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1396{
51470298 1397 ssh->pktout.length = 5;
1398 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1399}
51470298 1400static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1401{
51470298 1402 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1403}
51470298 1404static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1405{
7cca0d81 1406 unsigned char x[4];
1407 PUT_32BIT(x, value);
51470298 1408 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1409}
51470298 1410static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1411{
51470298 1412 ssh2_pkt_adduint32(ssh, 0);
1413 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1414}
51470298 1415static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1416{
51470298 1417 ssh2_pkt_adddata(ssh, data, strlen(data));
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_data(Ssh ssh, char *data, int len)
32874aea 1422{
51470298 1423 ssh2_pkt_adddata(ssh, data, len);
1424 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1425 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1426}
51470298 1427static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1428{
51470298 1429 ssh2_pkt_addstring_start(ssh);
1430 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1431}
32874aea 1432static char *ssh2_mpint_fmt(Bignum b, int *len)
1433{
7cca0d81 1434 unsigned char *p;
32874aea 1435 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1436 p = smalloc(n + 1);
7cca0d81 1437 if (!p)
32874aea 1438 fatalbox("out of memory");
7cca0d81 1439 p[0] = 0;
3709bfe9 1440 for (i = 1; i <= n; i++)
32874aea 1441 p[i] = bignum_byte(b, n - i);
7cca0d81 1442 i = 0;
32874aea 1443 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1444 i++;
1445 memmove(p, p + i, n + 1 - i);
1446 *len = n + 1 - i;
7cca0d81 1447 return p;
1448}
51470298 1449static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1450{
7cca0d81 1451 unsigned char *p;
1452 int len;
1453 p = ssh2_mpint_fmt(b, &len);
51470298 1454 ssh2_pkt_addstring_start(ssh);
1455 ssh2_pkt_addstring_data(ssh, p, len);
dcbde236 1456 sfree(p);
7cca0d81 1457}
b185170a 1458
1459/*
1460 * Construct an SSH2 final-form packet: compress it, encrypt it,
1461 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1462 * ssh->pktout.data. Total length is returned.
b185170a 1463 */
51470298 1464static int ssh2_pkt_construct(Ssh ssh)
32874aea 1465{
7cca0d81 1466 int cipherblk, maclen, padding, i;
7cca0d81 1467
a8327734 1468 if (ssh->logctx)
1469 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1470 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1471 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1472
7cca0d81 1473 /*
4ba9b64b 1474 * Compress packet payload.
1475 */
4ba9b64b 1476 {
1477 unsigned char *newpayload;
1478 int newlen;
51470298 1479 if (ssh->cscomp &&
5366aed8 1480 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1481 ssh->pktout.length - 5,
51470298 1482 &newpayload, &newlen)) {
1483 ssh->pktout.length = 5;
1484 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1485 sfree(newpayload);
4ba9b64b 1486 }
1487 }
1488
1489 /*
7cca0d81 1490 * Add padding. At least four bytes, and must also bring total
1491 * length (minus MAC) up to a multiple of the block size.
1492 */
51470298 1493 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1494 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1495 padding = 4;
32874aea 1496 padding +=
51470298 1497 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1498 maclen = ssh->csmac ? ssh->csmac->len : 0;
1499 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1500 ssh->pktout.data[4] = padding;
7cca0d81 1501 for (i = 0; i < padding; i++)
51470298 1502 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1503 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1504 if (ssh->csmac)
e0e1a00d 1505 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1506 ssh->pktout.length + padding,
51470298 1507 ssh->v2_outgoing_sequence);
1508 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1509
1510 if (ssh->cscipher)
371e569c 1511 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1512 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1513
1514 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1515 return ssh->pktout.length + padding + maclen;
b185170a 1516}
1517
1518/*
1519 * Construct and send an SSH2 packet immediately.
1520 */
51470298 1521static void ssh2_pkt_send(Ssh ssh)
32874aea 1522{
5471d09a 1523 int len;
1524 int backlog;
51470298 1525 len = ssh2_pkt_construct(ssh);
1526 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1527 if (backlog > SSH_MAX_BACKLOG)
51470298 1528 ssh_throttle_all(ssh, 1, backlog);
b185170a 1529}
1530
1531/*
1532 * Construct an SSH2 packet and add it to a deferred data block.
1533 * Useful for sending multiple packets in a single sk_write() call,
1534 * to prevent a traffic-analysing listener from being able to work
1535 * out the length of any particular packet (such as the password
1536 * packet).
1537 *
1538 * Note that because SSH2 sequence-numbers its packets, this can
1539 * NOT be used as an m4-style `defer' allowing packets to be
1540 * constructed in one order and sent in another.
1541 */
51470298 1542static void ssh2_pkt_defer(Ssh ssh)
32874aea 1543{
51470298 1544 int len = ssh2_pkt_construct(ssh);
1545 if (ssh->deferred_len + len > ssh->deferred_size) {
1546 ssh->deferred_size = ssh->deferred_len + len + 128;
1547 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1548 ssh->deferred_size);
b185170a 1549 }
51470298 1550 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1551 ssh->deferred_len += len;
b185170a 1552}
1553
1554/*
1555 * Send the whole deferred data block constructed by
39065bed 1556 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1557 */
51470298 1558static void ssh_pkt_defersend(Ssh ssh)
32874aea 1559{
5471d09a 1560 int backlog;
51470298 1561 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1562 ssh->deferred_len = ssh->deferred_size = 0;
1563 sfree(ssh->deferred_send_data);
1564 ssh->deferred_send_data = NULL;
5471d09a 1565 if (backlog > SSH_MAX_BACKLOG)
51470298 1566 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1567}
1568
1569#if 0
32874aea 1570void bndebug(char *string, Bignum b)
1571{
7cca0d81 1572 unsigned char *p;
1573 int i, len;
1574 p = ssh2_mpint_fmt(b, &len);
1575 debug(("%s", string));
1576 for (i = 0; i < len; i++)
32874aea 1577 debug((" %02x", p[i]));
765c4200 1578 debug(("\n"));
dcbde236 1579 sfree(p);
7cca0d81 1580}
1581#endif
1582
32874aea 1583static void sha_mpint(SHA_State * s, Bignum b)
1584{
7cca0d81 1585 unsigned char *p;
1586 int len;
1587 p = ssh2_mpint_fmt(b, &len);
1588 sha_string(s, p, len);
dcbde236 1589 sfree(p);
7cca0d81 1590}
1591
1592/*
1593 * SSH2 packet decode functions.
1594 */
51470298 1595static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1596{
7cca0d81 1597 unsigned long value;
51470298 1598 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1599 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1600 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1601 ssh->pktin.savedpos += 4;
7cca0d81 1602 return value;
1603}
51470298 1604static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1605{
65a22376 1606 unsigned long value;
51470298 1607 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1608 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1609 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1610 ssh->pktin.savedpos++;
65a22376 1611 return value;
1612}
51470298 1613static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1614{
7cca0d81 1615 *p = NULL;
45068b27 1616 *length = 0;
51470298 1617 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1618 return;
51470298 1619 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1620 ssh->pktin.savedpos += 4;
1621 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1622 return;
51470298 1623 *p = ssh->pktin.data + ssh->pktin.savedpos;
1624 ssh->pktin.savedpos += *length;
7cca0d81 1625}
51470298 1626static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1627{
7cca0d81 1628 char *p;
3709bfe9 1629 int length;
7cca0d81 1630 Bignum b;
1631
51470298 1632 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1633 if (!p)
32874aea 1634 return NULL;
8d5de777 1635 if (p[0] & 0x80) {
a8327734 1636 bombout((ssh,"internal error: Can't handle negative mpints"));
32874aea 1637 return NULL;
8d5de777 1638 }
3709bfe9 1639 b = bignum_from_bytes(p, length);
7cca0d81 1640 return b;
1641}
1642
7d503c31 1643/*
1dd353b5 1644 * Helper function to add an SSH2 signature blob to a packet.
1645 * Expects to be shown the public key blob as well as the signature
1646 * blob. Normally works just like ssh2_pkt_addstring, but will
1647 * fiddle with the signature packet if necessary for
1648 * BUG_SSH2_RSA_PADDING.
1649 */
51470298 1650static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1651 void *sigblob_v, int sigblob_len)
1652{
1653 unsigned char *pkblob = (unsigned char *)pkblob_v;
1654 unsigned char *sigblob = (unsigned char *)sigblob_v;
1655
1656 /* dmemdump(pkblob, pkblob_len); */
1657 /* dmemdump(sigblob, sigblob_len); */
1658
1659 /*
1660 * See if this is in fact an ssh-rsa signature and a buggy
1661 * server; otherwise we can just do this the easy way.
1662 */
51470298 1663 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1664 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1665 int pos, len, siglen;
1666
1667 /*
1668 * Find the byte length of the modulus.
1669 */
1670
1671 pos = 4+7; /* skip over "ssh-rsa" */
1672 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1673 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1674 pos += 4; /* find modulus itself */
1675 while (len > 0 && pkblob[pos] == 0)
1676 len--, pos++;
1677 /* debug(("modulus length is %d\n", len)); */
1678
1679 /*
1680 * Now find the signature integer.
1681 */
1682 pos = 4+7; /* skip over "ssh-rsa" */
1683 siglen = GET_32BIT(sigblob+pos);
1684 /* debug(("signature length is %d\n", siglen)); */
1685
1686 if (len != siglen) {
1687 unsigned char newlen[4];
51470298 1688 ssh2_pkt_addstring_start(ssh);
1689 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1dd353b5 1690 /* dmemdump(sigblob, pos); */
1691 pos += 4; /* point to start of actual sig */
1692 PUT_32BIT(newlen, len);
51470298 1693 ssh2_pkt_addstring_data(ssh, newlen, 4);
1dd353b5 1694 /* dmemdump(newlen, 4); */
1695 newlen[0] = 0;
1696 while (len-- > siglen) {
51470298 1697 ssh2_pkt_addstring_data(ssh, newlen, 1);
1dd353b5 1698 /* dmemdump(newlen, 1); */
1699 }
51470298 1700 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1dd353b5 1701 /* dmemdump(sigblob+pos, siglen); */
1702 return;
1703 }
1704
1705 /* Otherwise fall through and do it the easy way. */
1706 }
1707
51470298 1708 ssh2_pkt_addstring_start(ssh);
1709 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1dd353b5 1710}
1711
1712/*
7d503c31 1713 * Examine the remote side's version string and compare it against
1714 * a list of known buggy implementations.
1715 */
51470298 1716static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1717{
1718 char *imp; /* pointer to implementation part */
7d503c31 1719 imp = vstring;
1720 imp += strcspn(imp, "-");
bd358db1 1721 if (*imp) imp++;
7d503c31 1722 imp += strcspn(imp, "-");
bd358db1 1723 if (*imp) imp++;
7d503c31 1724
51470298 1725 ssh->remote_bugs = 0;
7d503c31 1726
2c9c6388 1727 if (cfg.sshbug_ignore1 == BUG_ON ||
1728 (cfg.sshbug_ignore1 == BUG_AUTO &&
1729 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1730 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1731 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1732 /*
1733 * These versions don't support SSH1_MSG_IGNORE, so we have
1734 * to use a different defence against password length
1735 * sniffing.
1736 */
51470298 1737 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1738 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1739 }
1740
2c9c6388 1741 if (cfg.sshbug_plainpw1 == BUG_ON ||
1742 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1743 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1744 /*
1745 * These versions need a plain password sent; they can't
1746 * handle having a null and a random length of data after
1747 * the password.
1748 */
51470298 1749 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1750 logevent("We believe remote version needs a plain SSH1 password");
1751 }
1752
2c9c6388 1753 if (cfg.sshbug_rsa1 == BUG_ON ||
1754 (cfg.sshbug_rsa1 == BUG_AUTO &&
1755 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1756 /*
1757 * These versions apparently have no clue whatever about
1758 * RSA authentication and will panic and die if they see
1759 * an AUTH_RSA message.
1760 */
51470298 1761 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1762 logevent("We believe remote version can't handle RSA authentication");
1763 }
1764
2c9c6388 1765 if (cfg.sshbug_hmac2 == BUG_ON ||
1766 (cfg.sshbug_hmac2 == BUG_AUTO &&
1767 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1768 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1769 !strncmp(imp, "2.1 ", 4)))) {
32874aea 1770 /*
1771 * These versions have the HMAC bug.
1772 */
51470298 1773 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1774 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1775 }
1dd353b5 1776
2c9c6388 1777 if (cfg.sshbug_derivekey2 == BUG_ON ||
1778 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1779 (!strncmp(imp, "2.0.", 4)))) {
088bde77 1780 /*
1781 * These versions have the key-derivation bug (failing to
1782 * include the literal shared secret in the hashes that
1783 * generate the keys).
1784 */
51470298 1785 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1786 logevent("We believe remote version has SSH2 key-derivation bug");
1787 }
1788
2c9c6388 1789 if (cfg.sshbug_rsapad2 == BUG_ON ||
1790 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1791 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1792 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1dd353b5 1793 /*
1794 * These versions have the SSH2 RSA padding bug.
1795 */
51470298 1796 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1797 logevent("We believe remote version has SSH2 RSA padding bug");
1798 }
8e975795 1799
1800 if (cfg.sshbug_dhgex2 == BUG_ON) {
1801 /*
1802 * These versions have the SSH2 DH GEX bug.
1803 */
51470298 1804 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1805 logevent("We believe remote version has SSH2 DH group exchange bug");
1806 }
7d503c31 1807}
1808
51470298 1809static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1810{
51470298 1811 struct do_ssh_init_state {
1812 int vslen;
1813 char version[10];
1814 char *vstring;
1815 int vstrsize;
1816 int i;
1817 int proto1, proto2;
1818 };
1819 crState(do_ssh_init_state);
374330e2 1820
51470298 1821 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1822
1823 /* Search for the string "SSH-" in the input. */
51470298 1824 s->i = 0;
8df7a775 1825 while (1) {
1826 static const int transS[] = { 1, 2, 2, 1 };
1827 static const int transH[] = { 0, 0, 3, 0 };
1828 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1829 if (c == 'S')
51470298 1830 s->i = transS[s->i];
32874aea 1831 else if (c == 'H')
51470298 1832 s->i = transH[s->i];
32874aea 1833 else if (c == '-')
51470298 1834 s->i = transminus[s->i];
32874aea 1835 else
51470298 1836 s->i = 0;
1837 if (s->i < 0)
8df7a775 1838 break;
1839 crReturn(1); /* get another character */
374330e2 1840 }
8df7a775 1841
51470298 1842 s->vstrsize = 16;
1843 s->vstring = smalloc(s->vstrsize);
1844 strcpy(s->vstring, "SSH-");
1845 s->vslen = 4;
1846 s->i = 0;
374330e2 1847 while (1) {
8df7a775 1848 crReturn(1); /* get another char */
51470298 1849 if (s->vslen >= s->vstrsize - 1) {
1850 s->vstrsize += 16;
1851 s->vstring = srealloc(s->vstring, s->vstrsize);
32874aea 1852 }
51470298 1853 s->vstring[s->vslen++] = c;
1854 if (s->i >= 0) {
374330e2 1855 if (c == '-') {
51470298 1856 s->version[s->i] = '\0';
1857 s->i = -1;
1858 } else if (s->i < sizeof(s->version) - 1)
1859 s->version[s->i++] = c;
32874aea 1860 } else if (c == '\n')
374330e2 1861 break;
1862 }
1863
51470298 1864 ssh->agentfwd_enabled = FALSE;
1865 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1866
51470298 1867 s->vstring[s->vslen] = 0;
1868 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1869 {
1870 char *vlog;
1871 vlog = smalloc(20 + s->vslen);
1872 sprintf(vlog, "Server version: %s", s->vstring);
1873 logevent(vlog);
1874 sfree(vlog);
1875 }
1876 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1877
adf799dd 1878 /*
38d228a2 1879 * Decide which SSH protocol version to support.
adf799dd 1880 */
38d228a2 1881
1882 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1883 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1884 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1885 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1886
51470298 1887 if (cfg.sshprot == 0 && !s->proto1) {
a8327734 1888 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
38d228a2 1889 crReturn(0);
1890 }
51470298 1891 if (cfg.sshprot == 3 && !s->proto2) {
a8327734 1892 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
38d228a2 1893 crReturn(0);
1894 }
1895
51470298 1896 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1897 /*
38d228a2 1898 * Use v2 protocol.
32874aea 1899 */
1900 char verstring[80], vlog[100];
1901 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1902 SHA_Init(&ssh->exhashbase);
32874aea 1903 /*
1904 * Hash our version string and their version string.
1905 */
51470298 1906 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1907 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1908 sprintf(vlog, "We claim version: %s", verstring);
1909 logevent(vlog);
1910 strcat(verstring, "\n");
1911 logevent("Using SSH protocol version 2");
51470298 1912 sk_write(ssh->s, verstring, strlen(verstring));
1913 ssh->protocol = ssh2_protocol;
1914 ssh->version = 2;
1915 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1916 } else {
32874aea 1917 /*
38d228a2 1918 * Use v1 protocol.
32874aea 1919 */
1920 char verstring[80], vlog[100];
1921 sprintf(verstring, "SSH-%s-%s",
51470298 1922 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1923 sshver);
1924 sprintf(vlog, "We claim version: %s", verstring);
1925 logevent(vlog);
1926 strcat(verstring, "\n");
759712a6 1927
32874aea 1928 logevent("Using SSH protocol version 1");
51470298 1929 sk_write(ssh->s, verstring, strlen(verstring));
1930 ssh->protocol = ssh1_protocol;
1931 ssh->version = 1;
1932 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1933 }
51470298 1934 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1935
51470298 1936 sfree(s->vstring);
50526e47 1937
8df7a775 1938 crFinish(0);
1939}
1940
51470298 1941static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 1942{
51470298 1943 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 1944
1945 /*
1946 * To begin with, feed the characters one by one to the
1947 * protocol initialisation / selection function do_ssh_init().
1948 * When that returns 0, we're done with the initial greeting
1949 * exchange and can move on to packet discipline.
1950 */
1951 while (1) {
51470298 1952 int ret; /* need not be kept across crReturn */
8df7a775 1953 if (datalen == 0)
1954 crReturnV; /* more data please */
51470298 1955 ret = do_ssh_init(ssh, *data);
32874aea 1956 data++;
1957 datalen--;
8df7a775 1958 if (ret == 0)
1959 break;
1960 }
1961
1962 /*
1963 * We emerge from that loop when the initial negotiation is
1964 * over and we have selected an s_rdpkt function. Now pass
1965 * everything to s_rdpkt, and then pass the resulting packets
1966 * to the proper protocol handler.
1967 */
1968 if (datalen == 0)
1969 crReturnV;
1970 while (1) {
1971 while (datalen > 0) {
51470298 1972 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1973 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 1974 return;
1975 }
51470298 1976 ssh->protocol(ssh, NULL, 0, 1);
1977 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 1978 return;
1979 }
1980 }
1981 }
1982 crReturnV;
1983 }
1984 crFinishV;
1985}
1986
32874aea 1987static int ssh_closing(Plug plug, char *error_msg, int error_code,
1988 int calling_back)
1989{
51470298 1990 Ssh ssh = (Ssh) plug;
1991 ssh->state = SSH_STATE_CLOSED;
1992 if (ssh->s) {
1993 sk_close(ssh->s);
1994 ssh->s = NULL;
f3ab576e 1995 }
7e78000d 1996 if (error_msg) {
32874aea 1997 /* A socket error has occurred. */
247308b5 1998 logevent(error_msg);
a8327734 1999 connection_fatal(ssh->frontend, error_msg);
7e78000d 2000 } else {
2001 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2002 }
7e78000d 2003 return 0;
2004}
2005
32874aea 2006static int ssh_receive(Plug plug, int urgent, char *data, int len)
2007{
51470298 2008 Ssh ssh = (Ssh) plug;
2009 ssh_gotdata(ssh, data, len);
2010 if (ssh->state == SSH_STATE_CLOSED) {
2011 if (ssh->s) {
2012 sk_close(ssh->s);
2013 ssh->s = NULL;
32874aea 2014 }
2015 return 0;
3257deae 2016 }
fef97f43 2017 return 1;
374330e2 2018}
2019
5471d09a 2020static void ssh_sent(Plug plug, int bufsize)
2021{
51470298 2022 Ssh ssh = (Ssh) plug;
5471d09a 2023 /*
2024 * If the send backlog on the SSH socket itself clears, we
2025 * should unthrottle the whole world if it was throttled.
2026 */
2027 if (bufsize < SSH_MAX_BACKLOG)
51470298 2028 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2029}
2030
fb09bf1c 2031/*
8df7a775 2032 * Connect to specified host and port.
2033 * Returns an error message, or NULL on success.
6e1ebb76 2034 * Also places the canonical host name into `realhost'. It must be
2035 * freed by the caller.
8df7a775 2036 */
51470298 2037static char *connect_to_host(Ssh ssh, char *host, int port,
2038 char **realhost, int nodelay)
8df7a775 2039{
51470298 2040 static const struct plug_function_table fn_table = {
7e78000d 2041 ssh_closing,
5471d09a 2042 ssh_receive,
2043 ssh_sent,
2044 NULL
51470298 2045 };
7e78000d 2046
8df7a775 2047 SockAddr addr;
2048 char *err;
8df7a775 2049
51470298 2050 ssh->savedhost = smalloc(1 + strlen(host));
2051 if (!ssh->savedhost)
8df7a775 2052 fatalbox("Out of memory");
51470298 2053 strcpy(ssh->savedhost, host);
8df7a775 2054
2055 if (port < 0)
2056 port = 22; /* default ssh port */
51470298 2057 ssh->savedport = port;
8df7a775 2058
2059 /*
2060 * Try to find host.
2061 */
3ad9d396 2062 {
2063 char buf[200];
2064 sprintf(buf, "Looking up host \"%.170s\"", host);
2065 logevent(buf);
2066 }
8df7a775 2067 addr = sk_namelookup(host, realhost);
32874aea 2068 if ((err = sk_addr_error(addr)))
8df7a775 2069 return err;
2070
8df7a775 2071 /*
2072 * Open socket.
2073 */
3ad9d396 2074 {
2075 char buf[200], addrbuf[100];
2076 sk_getaddr(addr, addrbuf, 100);
2077 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2078 logevent(buf);
2079 }
51470298 2080 ssh->fn = &fn_table;
2081 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2082 if ((err = sk_socket_error(ssh->s))) {
2083 ssh->s = NULL;
8df7a775 2084 return err;
67c4ba2e 2085 }
8df7a775 2086
8df7a775 2087 return NULL;
2088}
2089
2090/*
5471d09a 2091 * Throttle or unthrottle the SSH connection.
2092 */
51470298 2093static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2094{
51470298 2095 int old_count = ssh->v1_throttle_count;
2096 ssh->v1_throttle_count += adjust;
2097 assert(ssh->v1_throttle_count >= 0);
2098 if (ssh->v1_throttle_count && !old_count) {
2099 sk_set_frozen(ssh->s, 1);
2100 } else if (!ssh->v1_throttle_count && old_count) {
2101 sk_set_frozen(ssh->s, 0);
5471d09a 2102 }
2103}
2104
2105/*
2106 * Throttle or unthrottle _all_ local data streams (for when sends
2107 * on the SSH connection itself back up).
2108 */
51470298 2109static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2110{
2111 int i;
2112 struct ssh_channel *c;
2113
51470298 2114 if (enable == ssh->throttled_all)
5471d09a 2115 return;
51470298 2116 ssh->throttled_all = enable;
2117 ssh->overall_bufsize = bufsize;
2118 if (!ssh->channels)
5471d09a 2119 return;
51470298 2120 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2121 switch (c->type) {
2122 case CHAN_MAINSESSION:
2123 /*
2124 * This is treated separately, outside the switch.
2125 */
2126 break;
2127 case CHAN_X11:
2128 x11_override_throttle(c->u.x11.s, enable);
2129 break;
2130 case CHAN_AGENT:
2131 /* Agent channels require no buffer management. */
2132 break;
2133 case CHAN_SOCKDATA:
2134 pfd_override_throttle(c->u.x11.s, enable);
2135 break;
2136 }
2137 }
2138}
2139
2140/*
51470298 2141 * Username and password input, abstracted off into routines
2142 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2143 */
0405e71f 2144
2145/* Set up a username or password input loop on a given buffer. */
51470298 2146void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2147{
51470298 2148 ssh->userpass_input_buffer = buffer;
2149 ssh->userpass_input_buflen = buflen;
2150 ssh->userpass_input_bufpos = 0;
2151 ssh->userpass_input_echo = echo;
0405e71f 2152}
2153
2154/*
2155 * Process some terminal data in the course of username/password
2156 * input. Returns >0 for success (line of input returned in
2157 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2158 * for inconclusive (keep waiting for more input please).
2159 */
51470298 2160int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2161{
2162 char c;
2163
2164 while (inlen--) {
2165 switch (c = *in++) {
2166 case 10:
2167 case 13:
51470298 2168 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2169 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2170 return +1;
2171 break;
2172 case 8:
2173 case 127:
51470298 2174 if (ssh->userpass_input_bufpos > 0) {
2175 if (ssh->userpass_input_echo)
2176 c_write_str(ssh, "\b \b");
2177 ssh->userpass_input_bufpos--;
0405e71f 2178 }
2179 break;
2180 case 21:
2181 case 27:
51470298 2182 while (ssh->userpass_input_bufpos > 0) {
2183 if (ssh->userpass_input_echo)
2184 c_write_str(ssh, "\b \b");
2185 ssh->userpass_input_bufpos--;
0405e71f 2186 }
2187 break;
2188 case 3:
2189 case 4:
2190 return -1;
2191 break;
2192 default:
2193 if (((c >= ' ' && c <= '~') ||
2194 ((unsigned char) c >= 160))
51470298 2195 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2196 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2197 if (ssh->userpass_input_echo)
2198 c_write(ssh, &c, 1);
0405e71f 2199 }
2200 break;
2201 }
2202 }
2203 return 0;
2204}
2205
2206/*
fb09bf1c 2207 * Handle the key exchange and user authentication phases.
2208 */
51470298 2209static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2210{
2d466ffd 2211 int i, j;
374330e2 2212 unsigned char cookie[8];
2213 struct RSAKey servkey, hostkey;
2214 struct MD5Context md5c;
51470298 2215 struct do_ssh1_login_state {
2216 int len;
2217 unsigned char *rsabuf, *keystr1, *keystr2;
2218 unsigned long supported_ciphers_mask, supported_auths_mask;
2219 int tried_publickey, tried_agent;
2220 int tis_auth_refused, ccard_auth_refused;
2221 unsigned char session_id[16];
2222 int cipher_type;
2223 char username[100];
2224 void *publickey_blob;
2225 int publickey_bloblen;
2226 char password[100];
2227 char prompt[200];
2228 int pos;
2229 char c;
2230 int pwpkt_type;
2231 unsigned char request[5], *response, *p;
2232 int responselen;
2233 int keyi, nkeys;
2234 int authed;
2235 struct RSAKey key;
2236 Bignum challenge;
2237 char *commentp;
2238 int commentlen;
2239 };
2240 crState(do_ssh1_login_state);
2241
2242 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2243
32874aea 2244 if (!ispkt)
2245 crWaitUntil(ispkt);
374330e2 2246
51470298 2247 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
a8327734 2248 bombout((ssh,"Public key packet not received"));
32874aea 2249 crReturn(0);
8d5de777 2250 }
374330e2 2251
c5e9c988 2252 logevent("Received public keys");
374330e2 2253
51470298 2254 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2255
51470298 2256 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2257 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2258
c5e9c988 2259 /*
1c2a93c4 2260 * Log the host key fingerprint.
c5e9c988 2261 */
c5e9c988 2262 {
2263 char logmsg[80];
1c2a93c4 2264 logevent("Host key fingerprint is:");
c5e9c988 2265 strcpy(logmsg, " ");
32874aea 2266 hostkey.comment = NULL;
2267 rsa_fingerprint(logmsg + strlen(logmsg),
2268 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2269 logevent(logmsg);
2270 }
2271
51470298 2272 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2273 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2274 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2275
51470298 2276 ssh->v1_local_protoflags =
2277 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2278 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2279
c5e9c988 2280 MD5Init(&md5c);
51470298 2281 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2282 MD5Update(&md5c, s->keystr1, servkey.bytes);
2283 MD5Update(&md5c, ssh->pktin.body, 8);
2284 MD5Final(s->session_id, &md5c);
374330e2 2285
32874aea 2286 for (i = 0; i < 32; i++)
51470298 2287 ssh->session_key[i] = random_byte();
374330e2 2288
51470298 2289 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2290
51470298 2291 s->rsabuf = smalloc(s->len);
2292 if (!s->rsabuf)
374330e2 2293 fatalbox("Out of memory");
2294
89ee5268 2295 /*
2296 * Verify the host key.
2297 */
2298 {
32874aea 2299 /*
2300 * First format the key into a string.
2301 */
2302 int len = rsastr_len(&hostkey);
2303 char fingerprint[100];
2304 char *keystr = smalloc(len);
2305 if (!keystr)
2306 fatalbox("Out of memory");
2307 rsastr_fmt(keystr, &hostkey);
2308 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2309 verify_ssh_host_key(ssh->frontend,
2310 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2311 fingerprint);
2312 sfree(keystr);
2313 }
2314
2315 for (i = 0; i < 32; i++) {
51470298 2316 s->rsabuf[i] = ssh->session_key[i];
374330e2 2317 if (i < 16)
51470298 2318 s->rsabuf[i] ^= s->session_id[i];
374330e2 2319 }
2320
2321 if (hostkey.bytes > servkey.bytes) {
51470298 2322 rsaencrypt(s->rsabuf, 32, &servkey);
2323 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2324 } else {
51470298 2325 rsaencrypt(s->rsabuf, 32, &hostkey);
2326 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2327 }
2328
c5e9c988 2329 logevent("Encrypted session key");
2330
ca20bfcf 2331 {
2332 int cipher_chosen = 0, warn = 0;
2333 char *cipher_string = NULL;
51470298 2334 int i;
ca20bfcf 2335 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2336 int next_cipher = cfg.ssh_cipherlist[i];
2337 if (next_cipher == CIPHER_WARN) {
2338 /* If/when we choose a cipher, warn about it */
2339 warn = 1;
2340 } else if (next_cipher == CIPHER_AES) {
2341 /* XXX Probably don't need to mention this. */
2342 logevent("AES not supported in SSH1, skipping");
2343 } else {
2344 switch (next_cipher) {
51470298 2345 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2346 cipher_string = "3DES"; break;
51470298 2347 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2348 cipher_string = "Blowfish"; break;
51470298 2349 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2350 cipher_string = "single-DES"; break;
2351 }
51470298 2352 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2353 cipher_chosen = 1;
2354 }
2355 }
2356 if (!cipher_chosen) {
51470298 2357 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
a8327734 2358 bombout((ssh,"Server violates SSH 1 protocol by not "
ca20bfcf 2359 "supporting 3DES encryption"));
2360 else
2361 /* shouldn't happen */
a8327734 2362 bombout((ssh,"No supported ciphers found"));
a99a05c0 2363 crReturn(0);
2364 }
ca20bfcf 2365
2366 /* Warn about chosen cipher if necessary. */
2367 if (warn)
a8327734 2368 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2369 }
ca20bfcf 2370
51470298 2371 switch (s->cipher_type) {
32874aea 2372 case SSH_CIPHER_3DES:
2373 logevent("Using 3DES encryption");
2374 break;
2375 case SSH_CIPHER_DES:
2376 logevent("Using single-DES encryption");
2377 break;
2378 case SSH_CIPHER_BLOWFISH:
2379 logevent("Using Blowfish encryption");
2380 break;
c5e9c988 2381 }
bea1ef5f 2382
51470298 2383 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2384 PKT_CHAR, s->cipher_type,
32874aea 2385 PKT_DATA, cookie, 8,
51470298 2386 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2387 PKT_DATA, s->rsabuf, s->len,
2388 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2389
c5e9c988 2390 logevent("Trying to enable encryption...");
374330e2 2391
51470298 2392 sfree(s->rsabuf);
374330e2 2393
51470298 2394 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2395 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2396 &ssh_3des);
371e569c 2397 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2398 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2399 {
2400 char buf[256];
2401 sprintf(buf, "Initialised %.200s encryption", ssh->cipher->text_name);
2402 logevent(buf);
2403 }
374330e2 2404
0183b242 2405 ssh->crcda_ctx = crcda_make_context();
2406 logevent("Installing CRC compensation attack detector");
2407
fb09bf1c 2408 crWaitUntil(ispkt);
374330e2 2409
51470298 2410 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2411 bombout((ssh,"Encryption not successfully enabled"));
32874aea 2412 crReturn(0);
8d5de777 2413 }
374330e2 2414
c5e9c988 2415 logevent("Successfully started encryption");
2416
374330e2 2417 fflush(stdout);
2418 {
67779be7 2419 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2420 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2421 if (!ssh_get_line("login as: ",
51470298 2422 s->username, sizeof(s->username), FALSE)) {
32874aea 2423 /*
2424 * get_line failed to get a username.
2425 * Terminate.
2426 */
2427 logevent("No username provided. Abandoning session.");
51470298 2428 ssh->state = SSH_STATE_CLOSED;
32874aea 2429 crReturn(1);
2430 }
2431 } else {
51470298 2432 int ret; /* need not be kept over crReturn */
2433 c_write_str(ssh, "login as: ");
2434 ssh->send_ok = 1;
0405e71f 2435
51470298 2436 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2437 do {
32874aea 2438 crWaitUntil(!ispkt);
51470298 2439 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2440 } while (ret == 0);
2441 if (ret < 0)
2442 cleanup_exit(0);
51470298 2443 c_write_str(ssh, "\r\n");
32874aea 2444 }
2445 } else {
51470298 2446 strncpy(s->username, cfg.username, sizeof(s->username));
2447 s->username[sizeof(s->username)-1] = '\0';
374330e2 2448 }
fb09bf1c 2449
51470298 2450 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2451 {
51470298 2452 char userlog[22 + sizeof(s->username)];
2453 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2454 logevent(userlog);
32874aea 2455 if (flags & FLAG_INTERACTIVE &&
2456 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2457 strcat(userlog, "\r\n");
51470298 2458 c_write_str(ssh, userlog);
3c8e959b 2459 }
c5e9c988 2460 }
374330e2 2461 }
2462
fb09bf1c 2463 crWaitUntil(ispkt);
374330e2 2464
51470298 2465 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2466 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2467 s->tried_publickey = s->tried_agent = 1;
0df73905 2468 } else {
51470298 2469 s->tried_publickey = s->tried_agent = 0;
0df73905 2470 }
51470298 2471 s->tis_auth_refused = s->ccard_auth_refused = 0;
396778f1 2472 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2473 if (*cfg.keyfile) {
51470298 2474 if (!rsakey_pubblob(cfg.keyfile,
2475 &s->publickey_blob, &s->publickey_bloblen))
2476 s->publickey_blob = NULL;
396778f1 2477 } else
51470298 2478 s->publickey_blob = NULL;
7cca0d81 2479
51470298 2480 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2481 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2482
51470298 2483 if (agent_exists() && !s->tried_agent) {
32874aea 2484 /*
2485 * Attempt RSA authentication using Pageant.
2486 */
32874aea 2487 void *r;
2488
51470298 2489 s->authed = FALSE;
2490 s->tried_agent = 1;
32874aea 2491 logevent("Pageant is running. Requesting keys.");
2492
2493 /* Request the keys held by the agent. */
51470298 2494 PUT_32BIT(s->request, 1);
2495 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2496 agent_query(s->request, 5, &r, &s->responselen);
2497 s->response = (unsigned char *) r;
2498 if (s->response && s->responselen >= 5 &&
2499 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2500 s->p = s->response + 5;
2501 s->nkeys = GET_32BIT(s->p);
2502 s->p += 4;
32874aea 2503 {
2504 char buf[64];
51470298 2505 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2506 logevent(buf);
2507 }
51470298 2508 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2509 {
2510 char buf[64];
51470298 2511 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2512 logevent(buf);
2513 }
51470298 2514 if (s->publickey_blob &&
2515 !memcmp(s->p, s->publickey_blob,
2516 s->publickey_bloblen)) {
396778f1 2517 logevent("This key matches configured key file");
51470298 2518 s->tried_publickey = 1;
396778f1 2519 }
51470298 2520 s->p += 4;
2521 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2522 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2523 s->commentlen = GET_32BIT(s->p);
2524 s->p += 4;
2525 s->commentp = s->p;
2526 s->p += s->commentlen;
2527 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2528 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2529 crWaitUntil(ispkt);
51470298 2530 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2531 logevent("Key refused");
2532 continue;
2533 }
2534 logevent("Received RSA challenge");
51470298 2535 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2536 {
2537 char *agentreq, *q, *ret;
2d466ffd 2538 void *vret;
32874aea 2539 int len, retlen;
2540 len = 1 + 4; /* message type, bit count */
51470298 2541 len += ssh1_bignum_length(s->key.exponent);
2542 len += ssh1_bignum_length(s->key.modulus);
2543 len += ssh1_bignum_length(s->challenge);
32874aea 2544 len += 16; /* session id */
2545 len += 4; /* response format */
2546 agentreq = smalloc(4 + len);
2547 PUT_32BIT(agentreq, len);
2548 q = agentreq + 4;
2549 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2550 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2551 q += 4;
51470298 2552 q += ssh1_write_bignum(q, s->key.exponent);
2553 q += ssh1_write_bignum(q, s->key.modulus);
2554 q += ssh1_write_bignum(q, s->challenge);
2555 memcpy(q, s->session_id, 16);
32874aea 2556 q += 16;
2557 PUT_32BIT(q, 1); /* response format */
2d466ffd 2558 agent_query(agentreq, len + 4, &vret, &retlen);
2559 ret = vret;
32874aea 2560 sfree(agentreq);
2561 if (ret) {
2562 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2563 logevent("Sending Pageant's response");
51470298 2564 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2565 PKT_DATA, ret + 5, 16,
2566 PKT_END);
2567 sfree(ret);
2568 crWaitUntil(ispkt);
51470298 2569 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2570 logevent
2571 ("Pageant's response accepted");
2572 if (flags & FLAG_VERBOSE) {
51470298 2573 c_write_str(ssh, "Authenticated using"
2574 " RSA key \"");
2575 c_write(ssh, s->commentp,
2576 s->commentlen);
2577 c_write_str(ssh, "\" from agent\r\n");
32874aea 2578 }
51470298 2579 s->authed = TRUE;
32874aea 2580 } else
2581 logevent
2582 ("Pageant's response not accepted");
2583 } else {
2584 logevent
2585 ("Pageant failed to answer challenge");
2586 sfree(ret);
2587 }
2588 } else {
2589 logevent("No reply received from Pageant");
2590 }
2591 }
51470298 2592 freebn(s->key.exponent);
2593 freebn(s->key.modulus);
2594 freebn(s->challenge);
2595 if (s->authed)
32874aea 2596 break;
2597 }
2598 }
51470298 2599 if (s->authed)
32874aea 2600 break;
2601 }
51470298 2602 if (*cfg.keyfile && !s->tried_publickey)
2603 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2604
614a20a0 2605 if (cfg.try_tis_auth &&
51470298 2606 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2607 !s->tis_auth_refused) {
2608 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2609 logevent("Requested TIS authentication");
51470298 2610 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2611 crWaitUntil(ispkt);
51470298 2612 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2613 logevent("TIS authentication declined");
2614 if (flags & FLAG_INTERACTIVE)
51470298 2615 c_write_str(ssh, "TIS authentication refused.\r\n");
2616 s->tis_auth_refused = 1;
614a20a0 2617 continue;
32874aea 2618 } else {
51470298 2619 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2620 logevent("Received TIS challenge");
51470298 2621 if (challengelen > sizeof(s->prompt) - 1)
2622 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2623 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2624 /* Prompt heuristic comes from OpenSSH */
51470298 2625 strncpy(s->prompt + challengelen,
2626 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2627 "": "\r\nResponse: ",
51470298 2628 (sizeof s->prompt) - challengelen);
2629 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2630 }
2631 }
614a20a0 2632 if (cfg.try_tis_auth &&
51470298 2633 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2634 !s->ccard_auth_refused) {
2635 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2636 logevent("Requested CryptoCard authentication");
51470298 2637 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2638 crWaitUntil(ispkt);
51470298 2639 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2640 logevent("CryptoCard authentication declined");
51470298 2641 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2642 s->ccard_auth_refused = 1;
614a20a0 2643 continue;
32874aea 2644 } else {
51470298 2645 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2646 logevent("Received CryptoCard challenge");
51470298 2647 if (challengelen > sizeof(s->prompt) - 1)
2648 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2649 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2650 strncpy(s->prompt + challengelen,
2651 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2652 "" : "\r\nResponse: ",
51470298 2653 sizeof(s->prompt) - challengelen);
2654 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2655 }
2656 }
51470298 2657 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2658 sprintf(s->prompt, "%.90s@%.90s's password: ",
2659 s->username, ssh->savedhost);
32874aea 2660 }
51470298 2661 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2662 char *comment = NULL;
231ee168 2663 int type;
2664 char msgbuf[256];
32874aea 2665 if (flags & FLAG_VERBOSE)
51470298 2666 c_write_str(ssh, "Trying public key authentication.\r\n");
231ee168 2667 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2668 logevent(msgbuf);
2669 type = key_type(cfg.keyfile);
2670 if (type != SSH_KEYTYPE_SSH1) {
2671 sprintf(msgbuf, "Key is of wrong type (%s)",
2672 key_type_to_str(type));
2673 logevent(msgbuf);
51470298 2674 c_write_str(ssh, msgbuf);
2675 c_write_str(ssh, "\r\n");
2676 s->tried_publickey = 1;
231ee168 2677 continue;
2678 }
32874aea 2679 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2680 if (flags & FLAG_VERBOSE)
51470298 2681 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2682 goto tryauth;
2683 }
51470298 2684 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2685 sfree(comment);
2686 }
a52f067e 2687
614a20a0 2688 /*
2689 * Show password prompt, having first obtained it via a TIS
2690 * or CryptoCard exchange if we're doing TIS or CryptoCard
2691 * authentication.
2692 */
fa17a66e 2693 if (ssh_get_line) {
51470298 2694 if (!ssh_get_line(s->prompt, s->password,
2695 sizeof(s->password), TRUE)) {
32874aea 2696 /*
2697 * get_line failed to get a password (for example
2698 * because one was supplied on the command line
2699 * which has already failed to work). Terminate.
2700 */
51470298 2701 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2702 PKT_STR, "No more passwords available to try",
2703 PKT_END);
247308b5 2704 logevent("Unable to authenticate");
a8327734 2705 connection_fatal(ssh->frontend, "Unable to authenticate");
51470298 2706 ssh->state = SSH_STATE_CLOSED;
32874aea 2707 crReturn(1);
2708 }
fb09bf1c 2709 } else {
614a20a0 2710 /* Prompt may have come from server. We've munged it a bit, so
2711 * we know it to be zero-terminated at least once. */
51470298 2712 int ret; /* need not be saved over crReturn */
2713 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2714 s->pos = 0;
0405e71f 2715
51470298 2716 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2717 do {
32874aea 2718 crWaitUntil(!ispkt);
51470298 2719 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2720 } while (ret == 0);
2721 if (ret < 0)
2722 cleanup_exit(0);
51470298 2723 c_write_str(ssh, "\r\n");
32874aea 2724 }
2725
2726 tryauth:
51470298 2727 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2728 /*
2729 * Try public key authentication with the specified
2730 * key file.
2731 */
51470298 2732 s->tried_publickey = 1;
2733
2734 {
2735 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2736 if (ret == 0) {
2737 c_write_str(ssh, "Couldn't load private key from ");
2738 c_write_str(ssh, cfg.keyfile);
2739 c_write_str(ssh, ".\r\n");
2740 continue; /* go and try password */
2741 }
2742 if (ret == -1) {
2743 c_write_str(ssh, "Wrong passphrase.\r\n");
2744 s->tried_publickey = 0;
2745 continue; /* try again */
2746 }
32874aea 2747 }
2748
2749 /*
2750 * Send a public key attempt.
2751 */
51470298 2752 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2753 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2754
2755 crWaitUntil(ispkt);
51470298 2756 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2757 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2758 continue; /* go and try password */
2759 }
51470298 2760 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
a8327734 2761 bombout((ssh,"Bizarre response to offer of public key"));
32874aea 2762 crReturn(0);
2763 }
32874aea 2764
51470298 2765 {
2766 int i;
2767 unsigned char buffer[32];
2768 Bignum challenge, response;
2769
2770 ssh1_read_bignum(ssh->pktin.body, &challenge);
2771 response = rsadecrypt(challenge, &s->key);
2772 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2773
51470298 2774 for (i = 0; i < 32; i++) {
2775 buffer[i] = bignum_byte(response, 31 - i);
2776 }
2777
2778 MD5Init(&md5c);
2779 MD5Update(&md5c, buffer, 32);
2780 MD5Update(&md5c, s->session_id, 16);
2781 MD5Final(buffer, &md5c);
32874aea 2782
51470298 2783 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2784 PKT_DATA, buffer, 16, PKT_END);
2785
2786 freebn(challenge);
2787 freebn(response);
2788 }
32874aea 2789
2790 crWaitUntil(ispkt);
51470298 2791 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2792 if (flags & FLAG_VERBOSE)
51470298 2793 c_write_str(ssh, "Failed to authenticate with"
2794 " our public key.\r\n");
32874aea 2795 continue; /* go and try password */
51470298 2796 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2797 bombout((ssh,"Bizarre response to RSA authentication response"));
32874aea 2798 crReturn(0);
2799 }
2800
2801 break; /* we're through! */
2802 } else {
51470298 2803 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2804 /*
2805 * Defence against traffic analysis: we send a
2806 * whole bunch of packets containing strings of
2807 * different lengths. One of these strings is the
2808 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2809 * The others are all random data in
2810 * SSH1_MSG_IGNORE packets. This way a passive
2811 * listener can't tell which is the password, and
2812 * hence can't deduce the password length.
2813 *
2814 * Anybody with a password length greater than 16
2815 * bytes is going to have enough entropy in their
2816 * password that a listener won't find it _that_
2817 * much help to know how long it is. So what we'll
2818 * do is:
2819 *
2820 * - if password length < 16, we send 15 packets
2821 * containing string lengths 1 through 15
2822 *
2823 * - otherwise, we let N be the nearest multiple
2824 * of 8 below the password length, and send 8
2825 * packets containing string lengths N through
2826 * N+7. This won't obscure the order of
2827 * magnitude of the password length, but it will
2828 * introduce a bit of extra uncertainty.
2829 *
2830 * A few servers (the old 1.2.18 through 1.2.22)
2831 * can't deal with SSH1_MSG_IGNORE. For these
2832 * servers, we need an alternative defence. We make
2833 * use of the fact that the password is interpreted
2834 * as a C string: so we can append a NUL, then some
2835 * random data.
bd358db1 2836 *
2837 * One server (a Cisco one) can deal with neither
2838 * SSH1_MSG_IGNORE _nor_ a padded password string.
2839 * For this server we are left with no defences
2840 * against password length sniffing.
32874aea 2841 */
51470298 2842 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2843 /*
2844 * The server can deal with SSH1_MSG_IGNORE, so
2845 * we can use the primary defence.
2846 */
32874aea 2847 int bottom, top, pwlen, i;
2848 char *randomstr;
2849
51470298 2850 pwlen = strlen(s->password);
32874aea 2851 if (pwlen < 16) {
2852 bottom = 0; /* zero length passwords are OK! :-) */
2853 top = 15;
2854 } else {
2855 bottom = pwlen & ~7;
2856 top = bottom + 7;
2857 }
2858
2859 assert(pwlen >= bottom && pwlen <= top);
2860
2861 randomstr = smalloc(top + 1);
2862
2863 for (i = bottom; i <= top; i++) {
2864 if (i == pwlen)
51470298 2865 defer_packet(ssh, s->pwpkt_type,
2866 PKT_STR, s->password, PKT_END);
32874aea 2867 else {
2868 for (j = 0; j < i; j++) {
2869 do {
2870 randomstr[j] = random_byte();
2871 } while (randomstr[j] == '\0');
2872 }
2873 randomstr[i] = '\0';
51470298 2874 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 2875 PKT_STR, randomstr, PKT_END);
2876 }
2877 }
bd358db1 2878 logevent("Sending password with camouflage packets");
51470298 2879 ssh_pkt_defersend(ssh);
bd358db1 2880 }
51470298 2881 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2882 /*
2883 * The server can't deal with SSH1_MSG_IGNORE
2884 * but can deal with padded passwords, so we
2885 * can use the secondary defence.
2886 */
bd358db1 2887 char string[64];
51470298 2888 char *ss;
bd358db1 2889 int len;
2890
51470298 2891 len = strlen(s->password);
bd358db1 2892 if (len < sizeof(string)) {
51470298 2893 ss = string;
2894 strcpy(string, s->password);
bd358db1 2895 len++; /* cover the zero byte */
2896 while (len < sizeof(string)) {
2897 string[len++] = (char) random_byte();
2898 }
2899 } else {
51470298 2900 ss = s->password;
bd358db1 2901 }
2902 logevent("Sending length-padded password");
51470298 2903 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2904 PKT_DATA, ss, len, PKT_END);
bd358db1 2905 } else {
2906 /*
2907 * The server has _both_
2908 * BUG_CHOKES_ON_SSH1_IGNORE and
2909 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2910 * therefore nothing we can do.
2911 */
2912 int len;
51470298 2913 len = strlen(s->password);
bd358db1 2914 logevent("Sending unpadded password");
51470298 2915 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2916 PKT_DATA, s->password, len, PKT_END);
32874aea 2917 }
2918 } else {
51470298 2919 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 2920 }
2921 }
c5e9c988 2922 logevent("Sent password");
51470298 2923 memset(s->password, 0, strlen(s->password));
fb09bf1c 2924 crWaitUntil(ispkt);
51470298 2925 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2926 if (flags & FLAG_VERBOSE)
51470298 2927 c_write_str(ssh, "Access denied\r\n");
c5e9c988 2928 logevent("Authentication refused");
51470298 2929 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
a8327734 2930 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
32874aea 2931 crReturn(0);
374330e2 2932 }
2933 }
2934
c5e9c988 2935 logevent("Authentication successful");
2936
fb09bf1c 2937 crFinish(1);
2938}
2939
32874aea 2940void sshfwd_close(struct ssh_channel *c)
2941{
51470298 2942 Ssh ssh = c->ssh;
2943
80e48603 2944 if (c && !c->closes) {
4ed34d25 2945 /*
2946 * If the channel's remoteid is -1, we have sent
2947 * CHANNEL_OPEN for this channel, but it hasn't even been
2948 * acknowledged by the server. So we must set a close flag
2949 * on it now, and then when the server acks the channel
2950 * open, we can close it then.
2951 */
36cac739 2952 if (((int)c->remoteid) != -1) {
51470298 2953 if (ssh->version == 1) {
2954 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 2955 PKT_END);
2956 } else {
51470298 2957 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2958 ssh2_pkt_adduint32(ssh, c->remoteid);
2959 ssh2_pkt_send(ssh);
4ed34d25 2960 }
32874aea 2961 }
0357890f 2962 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2963 if (c->type == CHAN_X11) {
2964 c->u.x11.s = NULL;
d74d141c 2965 logevent("Forwarded X11 connection terminated");
4ed34d25 2966 } else if (c->type == CHAN_SOCKDATA ||
2967 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2968 c->u.pfd.s = NULL;
2969 logevent("Forwarded port closed");
32874aea 2970 }
2971 }
2972}
2973
5471d09a 2974int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2975{
51470298 2976 Ssh ssh = c->ssh;
2977
2978 if (ssh->version == 1) {
2979 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 2980 PKT_INT, c->remoteid,
2981 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2982 /*
2983 * In SSH1 we can return 0 here - implying that forwarded
2984 * connections are never individually throttled - because
2985 * the only circumstance that can cause throttling will be
2986 * the whole SSH connection backing up, in which case
2987 * _everything_ will be throttled as a whole.
2988 */
2989 return 0;
783415f8 2990 } else {
32874aea 2991 ssh2_add_channel_data(c, buf, len);
5471d09a 2992 return ssh2_try_send(c);
2993 }
2994}
2995
2996void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2997{
51470298 2998 Ssh ssh = c->ssh;
2999
3000 if (ssh->version == 1) {
5471d09a 3001 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3002 c->v.v1.throttling = 0;
51470298 3003 ssh1_throttle(ssh, -1);
5471d09a 3004 }
3005 } else {
3006 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3007 }
9c964e85 3008}
3009
51470298 3010static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3011{
51470298 3012 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3013
3014 random_init();
3015
51470298 3016 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3017 crReturnV;
85ee8208 3018 }
51470298 3019 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3020 crReturnV;
fb09bf1c 3021
979310f1 3022 if (cfg.agentfwd && agent_exists()) {
32874aea 3023 logevent("Requesting agent forwarding");
51470298 3024 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3025 do {
3026 crReturnV;
3027 } while (!ispkt);
51470298 3028 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3029 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3030 bombout((ssh,"Protocol confusion"));
32874aea 3031 crReturnV;
51470298 3032 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3033 logevent("Agent forwarding refused");
3034 } else {
3035 logevent("Agent forwarding enabled");
51470298 3036 ssh->agentfwd_enabled = TRUE;
db7d555c 3037 }
dacbd0e8 3038 }
3039
9c964e85 3040 if (cfg.x11_forward) {
32874aea 3041 char proto[20], data[64];
3042 logevent("Requesting X11 forwarding");
302121de 3043 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3044 data, sizeof(data));
51470298 3045 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3046 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3047 PKT_STR, proto, PKT_STR, data,
3048 PKT_INT, 0, PKT_END);
3049 } else {
51470298 3050 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3051 PKT_STR, proto, PKT_STR, data, PKT_END);
3052 }
3053 do {
3054 crReturnV;
3055 } while (!ispkt);
51470298 3056 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3057 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3058 bombout((ssh,"Protocol confusion"));
32874aea 3059 crReturnV;
51470298 3060 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3061 logevent("X11 forwarding refused");
3062 } else {
3063 logevent("X11 forwarding enabled");
51470298 3064 ssh->X11_fwd_enabled = TRUE;
9c964e85 3065 }
3066 }
3067
d74d141c 3068 {
9bf696b1 3069 char type;
d74d141c 3070 int n;
a4fc0d74 3071 int sport,dport,sserv,dserv;
d74d141c 3072 char sports[256], dports[256], host[256];
3073 char buf[1024];
a4fc0d74 3074 struct servent *se;
d74d141c 3075
51470298 3076 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3077 /* Add port forwardings. */
51470298 3078 ssh->portfwd_strptr = cfg.portfwd;
3079 while (*ssh->portfwd_strptr) {
3080 type = *ssh->portfwd_strptr++;
d74d141c 3081 n = 0;
51470298 3082 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3083 sports[n++] = *ssh->portfwd_strptr++;
d74d141c 3084 sports[n] = 0;
51470298 3085 if (*ssh->portfwd_strptr == '\t')
3086 ssh->portfwd_strptr++;
d74d141c 3087 n = 0;
51470298 3088 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3089 host[n++] = *ssh->portfwd_strptr++;
d74d141c 3090 host[n] = 0;
51470298 3091 if (*ssh->portfwd_strptr == ':')
3092 ssh->portfwd_strptr++;
d74d141c 3093 n = 0;
51470298 3094 while (*ssh->portfwd_strptr)
3095 dports[n++] = *ssh->portfwd_strptr++;
d74d141c 3096 dports[n] = 0;
51470298 3097 ssh->portfwd_strptr++;
d74d141c 3098 dport = atoi(dports);
a4fc0d74 3099 dserv = 0;
3100 if (dport == 0) {
3101 dserv = 1;
3102 se = getservbyname(dports, NULL);
3103 if (se != NULL) {
3104 dport = ntohs(se->s_port);
3105 } else {
3106 sprintf(buf,
3107 "Service lookup failed for destination port \"%s\"",
3108 dports);
3109 logevent(buf);
3110 }
3111 }
d74d141c 3112 sport = atoi(sports);
a4fc0d74 3113 sserv = 0;
3114 if (sport == 0) {
3115 sserv = 1;
3116 se = getservbyname(sports, NULL);
3117 if (se != NULL) {
3118 sport = ntohs(se->s_port);
3119 } else {
3120 sprintf(buf,
3121 "Service lookup failed for source port \"%s\"",
3122 sports);
3123 logevent(buf);
3124 }
3125 }
d74d141c 3126 if (sport && dport) {
3127 if (type == 'L') {
6b78788a 3128 pfd_addforward(host, dport, sport, ssh);
a4fc0d74 3129 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3130 " %s:%.*s%.*s%d%.*s",
3131 sserv ? strlen(sports) : 0, sports,
3132 sserv, "(", sport, sserv, ")",
3133 host,
3134 dserv ? strlen(dports) : 0, dports,
3135 dserv, "(", dport, dserv, ")");
d74d141c 3136 logevent(buf);
3137 } else {
3138 struct ssh_rportfwd *pf;
3139 pf = smalloc(sizeof(*pf));
bc240b21 3140 strcpy(pf->dhost, host);
3141 pf->dport = dport;
51470298 3142 if (add234(ssh->rportfwds, pf) != pf) {
d74d141c 3143 sprintf(buf,
95bc8819 3144 "Duplicate remote port forwarding to %s:%d",
d74d141c 3145 host, dport);
3146 logevent(buf);
bc240b21 3147 sfree(pf);
d74d141c 3148 } else {
a4fc0d74 3149 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3150 " forward to %s:%.*s%.*s%d%.*s",
3151 sserv ? strlen(sports) : 0, sports,
3152 sserv, "(", sport, sserv, ")",
3153 host,
3154 dserv ? strlen(dports) : 0, dports,
3155 dserv, "(", dport, dserv, ")");
d74d141c 3156 logevent(buf);
51470298 3157 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3158 PKT_INT, sport,
3159 PKT_STR, host,
3160 PKT_INT, dport,
3161 PKT_END);
9bf696b1 3162 do {
3163 crReturnV;
3164 } while (!ispkt);
51470298 3165 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3166 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3167 bombout((ssh,"Protocol confusion"));
9bf696b1 3168 crReturnV;
51470298 3169 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3170 c_write_str(ssh, "Server refused port"
3171 " forwarding\r\n");
9bf696b1 3172 }
3173 logevent("Remote port forwarding enabled");
d74d141c 3174 }
3175 }
3176 }
3177 }
3178 }
3179
fef97f43 3180 if (!cfg.nopty) {
51470298 3181 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
32874aea 3182 PKT_STR, cfg.termtype,
51470298 3183 PKT_INT, ssh->term_height,
3184 PKT_INT, ssh->term_width,
32874aea 3185 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3186 ssh->state = SSH_STATE_INTERMED;
32874aea 3187 do {
3188 crReturnV;
3189 } while (!ispkt);
51470298 3190 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3191 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3192 bombout((ssh,"Protocol confusion"));
32874aea 3193 crReturnV;
51470298 3194 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3195 c_write_str(ssh, "Server refused to allocate pty\r\n");
3196 ssh->editing = ssh->echoing = 1;
32874aea 3197 }
c5e9c988 3198 logevent("Allocated pty");
0965bee0 3199 } else {
51470298 3200 ssh->editing = ssh->echoing = 1;
374330e2 3201 }
3202
4ba9b64b 3203 if (cfg.compression) {
51470298 3204 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3205 do {
3206 crReturnV;
3207 } while (!ispkt);
51470298 3208 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3209 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
a8327734 3210 bombout((ssh,"Protocol confusion"));
32874aea 3211 crReturnV;
51470298 3212 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3213 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3214 }
4ba9b64b 3215 logevent("Started compression");
51470298 3216 ssh->v1_compressing = TRUE;
5366aed8 3217 ssh->cs_comp_ctx = zlib_compress_init();
3218 logevent("Initialised zlib (RFC1950) compression");
3219 ssh->sc_comp_ctx = zlib_decompress_init();
3220 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3221 }
3222
fd5e5847 3223 /*
3224 * Start the shell or command.
3225 *
3226 * Special case: if the first-choice command is an SSH2
3227 * subsystem (hence not usable here) and the second choice
3228 * exists, we fall straight back to that.
3229 */
3230 {
3231 char *cmd = cfg.remote_cmd_ptr;
3232
3233 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3234 cmd = cfg.remote_cmd_ptr2;
51470298 3235 ssh->fallback_cmd = TRUE;
fd5e5847 3236 }
3237 if (*cmd)
51470298 3238 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3239 else
51470298 3240 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3241 logevent("Started session");
3242 }
374330e2 3243
51470298 3244 ssh->state = SSH_STATE_SESSION;
3245 if (ssh->size_needed)
3246 ssh_size(ssh, ssh->term_width, ssh->term_height);
3247 if (ssh->eof_needed)
3248 ssh_special(ssh, TS_EOF);
374330e2 3249
b9d7bcad 3250 if (ssh->ldisc)
3251 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3252 ssh->send_ok = 1;
3253 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3254 while (1) {
3255 crReturnV;
3256 if (ispkt) {
51470298 3257 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3258 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3259 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3260 int bufsize =
51470298 3261 from_backend(ssh->frontend,
3262 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3263 ssh->pktin.body + 4, len);
3264 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3265 ssh->v1_stdout_throttling = 1;
3266 ssh1_throttle(ssh, +1);
5471d09a 3267 }
51470298 3268 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3269 ssh->state = SSH_STATE_CLOSED;
c5e9c988 3270 logevent("Received disconnect request");
32874aea 3271 crReturnV;
51470298 3272 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3273 /* Remote side is trying to open a channel to talk to our
3274 * X-Server. Give them back a local channel number. */
3275 struct ssh_channel *c;
9c964e85 3276
3277 logevent("Received X11 connect request");
3278 /* Refuse if X11 forwarding is disabled. */
51470298 3279 if (!ssh->X11_fwd_enabled) {
3280 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3281 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3282 logevent("Rejected X11 connect request");
3283 } else {
9c964e85 3284 c = smalloc(sizeof(struct ssh_channel));
51470298 3285 c->ssh = ssh;
9c964e85 3286
302121de 3287 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3288 ssh->x11auth) != NULL) {
32874aea 3289 logevent("opening X11 forward connection failed");
3290 sfree(c);
51470298 3291 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3292 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3293 PKT_END);
9c964e85 3294 } else {
32874aea 3295 logevent
3296 ("opening X11 forward connection succeeded");
51470298 3297 c->remoteid = GET_32BIT(ssh->pktin.body);
3298 c->localid = alloc_channel_id(ssh);
32874aea 3299 c->closes = 0;
5471d09a 3300 c->v.v1.throttling = 0;
32874aea 3301 c->type = CHAN_X11; /* identify channel type */
51470298 3302 add234(ssh->channels, c);
3303 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3304 PKT_INT, c->remoteid, PKT_INT,
3305 c->localid, PKT_END);
3306 logevent("Opened X11 forward channel");
9c964e85 3307 }
3308 }
51470298 3309 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3310 /* Remote side is trying to open a channel to talk to our
3311 * agent. Give them back a local channel number. */
3312 struct ssh_channel *c;
db7d555c 3313
3314 /* Refuse if agent forwarding is disabled. */
51470298 3315 if (!ssh->agentfwd_enabled) {
3316 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3317 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3318 } else {
dcbde236 3319 c = smalloc(sizeof(struct ssh_channel));
51470298 3320 c->ssh = ssh;
3321 c->remoteid = GET_32BIT(ssh->pktin.body);
3322 c->localid = alloc_channel_id(ssh);
db7d555c 3323 c->closes = 0;
5471d09a 3324 c->v.v1.throttling = 0;
32874aea 3325 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3326 c->u.a.lensofar = 0;
51470298 3327 add234(ssh->channels, c);
3328 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3329 PKT_INT, c->remoteid, PKT_INT, c->localid,
3330 PKT_END);
3331 }
51470298 3332 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3333 /* Remote side is trying to open a channel to talk to a
3334 * forwarded port. Give them back a local channel number. */
3335 struct ssh_channel *c;
3336 struct ssh_rportfwd pf;
3337 int hostsize, port;
3338 char host[256], buf[1024];
3339 char *p, *h, *e;
3340 c = smalloc(sizeof(struct ssh_channel));
51470298 3341 c->ssh = ssh;
d74d141c 3342
51470298 3343 hostsize = GET_32BIT(ssh->pktin.body+4);
3344 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
d74d141c 3345 if (h+1 < host+sizeof(host))
3346 *h++ = *p;
95bc8819 3347 p++;
d74d141c 3348 }
3349 *h = 0;
3350 port = GET_32BIT(p);
3351
bc240b21 3352 strcpy(pf.dhost, host);
3353 pf.dport = port;
d74d141c 3354
51470298 3355 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3356 sprintf(buf, "Rejected remote port open request for %s:%d",
3357 host, port);
3358 logevent(buf);
51470298 3359 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3360 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3361 } else {
3362 sprintf(buf, "Received remote port open request for %s:%d",
3363 host, port);
3364 logevent(buf);
3365 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3366 if (e != NULL) {
3367 char buf[256];
3368 sprintf(buf, "Port open failed: %s", e);
3369 logevent(buf);
3370 sfree(c);
51470298 3371 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3372 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3373 PKT_END);
3374 } else {
51470298 3375 c->remoteid = GET_32BIT(ssh->pktin.body);
3376 c->localid = alloc_channel_id(ssh);
d74d141c 3377 c->closes = 0;
5471d09a 3378 c->v.v1.throttling = 0;
d74d141c 3379 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3380 add234(ssh->channels, c);
3381 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3382 PKT_INT, c->remoteid, PKT_INT,
3383 c->localid, PKT_END);
3384 logevent("Forwarded port opened successfully");
3385 }
3386 }
3387
51470298 3388 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3389 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3390 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3391 struct ssh_channel *c;
3392
51470298 3393 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3394 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3395 c->remoteid = localid;
3396 c->type = CHAN_SOCKDATA;
7781f316 3397 c->v.v1.throttling = 0;
bc240b21 3398 pfd_confirm(c->u.pfd.s);
3399 }
d74d141c 3400
4ed34d25 3401 if (c && c->closes) {
3402 /*
3403 * We have a pending close on this channel,
3404 * which we decided on before the server acked
3405 * the channel open. So now we know the
3406 * remoteid, we can close it again.
3407 */
51470298 3408 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3409 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3410 }
3411
51470298 3412 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3413 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3414 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
724cface 3415 struct ssh_channel *c;
3416
51470298 3417 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3418 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3419 logevent("Forwarded connection refused by server");
3420 pfd_close(c->u.pfd.s);
51470298 3421 del234(ssh->channels, c);
724cface 3422 sfree(c);
3423 }
3424
51470298 3425 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3426 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3427 /* Remote side closes a channel. */
51470298 3428 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3429 struct ssh_channel *c;
51470298 3430 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3431 if (c && ((int)c->remoteid) != -1) {
32874aea 3432 int closetype;
3433 closetype =
51470298 3434 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3435
783415f8 3436 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3437 logevent("Forwarded X11 connection terminated");
9c964e85 3438 assert(c->u.x11.s != NULL);
3439 x11_close(c->u.x11.s);
3440 c->u.x11.s = NULL;
3441 }
d74d141c 3442 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3443 logevent("Forwarded port closed");
3444 assert(c->u.pfd.s != NULL);
3445 pfd_close(c->u.pfd.s);
3446 c->u.pfd.s = NULL;
3447 }
0357890f 3448
3449 c->closes |= (closetype << 2); /* seen this message */
3450 if (!(c->closes & closetype)) {
51470298 3451 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3452 PKT_END);
3453 c->closes |= closetype; /* sent it too */
3454 }
3455
3456 if (c->closes == 15) {
51470298 3457 del234(ssh->channels, c);
32874aea 3458 sfree(c);
3459 }
d0d844c1 3460 } else {
a8327734 3461 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3462 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3463 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3464 i));
32874aea 3465 }
51470298 3466 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3467 /* Data sent down one of our channels. */
51470298 3468 int i = GET_32BIT(ssh->pktin.body);
3469 int len = GET_32BIT(ssh->pktin.body + 4);
3470 unsigned char *p = ssh->pktin.body + 8;
32874aea 3471 struct ssh_channel *c;
51470298 3472 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3473 if (c) {
5471d09a 3474 int bufsize;
32874aea 3475 switch (c->type) {
3476 case CHAN_X11:
5471d09a 3477 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3478 break;
d74d141c 3479 case CHAN_SOCKDATA:
5471d09a 3480 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3481 break;
32874aea 3482 case CHAN_AGENT:
3483 /* Data for an agent message. Buffer it. */
3484 while (len > 0) {
3485 if (c->u.a.lensofar < 4) {
3486 int l = min(4 - c->u.a.lensofar, len);
3487 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3488 l);
3489 p += l;
3490 len -= l;
3491 c->u.a.lensofar += l;
3492 }
3493 if (c->u.a.lensofar == 4) {
3494 c->u.a.totallen =
3495 4 + GET_32BIT(c->u.a.msglen);
3496 c->u.a.message = smalloc(c->u.a.totallen);
3497 memcpy(c->u.a.message, c->u.a.msglen, 4);
3498 }
3499 if (c->u.a.lensofar >= 4 && len > 0) {
3500 int l =
3501 min(c->u.a.totallen - c->u.a.lensofar,
3502 len);
3503 memcpy(c->u.a.message + c->u.a.lensofar, p,
3504 l);
3505 p += l;
3506 len -= l;
3507 c->u.a.lensofar += l;
3508 }
3509 if (c->u.a.lensofar == c->u.a.totallen) {
3510 void *reply, *sentreply;
3511 int replylen;
3512 agent_query(c->u.a.message,
3513 c->u.a.totallen, &reply,
3514 &replylen);
3515 if (reply)
3516 sentreply = reply;
3517 else {
3518 /* Fake SSH_AGENT_FAILURE. */
3519 sentreply = "\0\0\0\1\5";
3520 replylen = 5;
3521 }
51470298 3522 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3523 PKT_INT, c->remoteid,
3524 PKT_INT, replylen,
3525 PKT_DATA, sentreply, replylen,
3526 PKT_END);
3527 if (reply)
3528 sfree(reply);
3529 sfree(c->u.a.message);
3530 c->u.a.lensofar = 0;
3531 }
3532 }
5471d09a 3533 bufsize = 0; /* agent channels never back up */
32874aea 3534 break;
3535 }
90347b95 3536 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3537 c->v.v1.throttling = 1;
51470298 3538 ssh1_throttle(ssh, +1);
5471d09a 3539 }
32874aea 3540 }
51470298 3541 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3542 /* may be from EXEC_SHELL on some servers */
51470298 3543 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3544 /* may be from EXEC_SHELL on some servers
374330e2 3545 * if no pty is available or in other odd cases. Ignore */
51470298 3546 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3547 char buf[100];
51470298 3548 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3549 sprintf(buf, "Server sent command exit status %d",
51470298 3550 ssh->exitcode);
d8d6c7e5 3551 logevent(buf);
51470298 3552 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3553 /*
3554 * In case `helpful' firewalls or proxies tack
3555 * extra human-readable text on the end of the
3556 * session which we might mistake for another
3557 * encrypted packet, we close the session once
3558 * we've sent EXIT_CONFIRMATION.
3559 */
51470298 3560 ssh->state = SSH_STATE_CLOSED;
4252c9cc 3561 crReturnV;
374330e2 3562 } else {
a8327734 3563 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
32874aea 3564 crReturnV;
374330e2 3565 }
3566 } else {
8df7a775 3567 while (inlen > 0) {
3568 int len = min(inlen, 512);
51470298 3569 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3570 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3571 in += len;
3572 inlen -= len;
3573 }
374330e2 3574 }
3575 }
3576
3577 crFinishV;
3578}
3579
3580/*
e5574168 3581 * Utility routine for decoding comma-separated strings in KEXINIT.
3582 */
32874aea 3583static int in_commasep_string(char *needle, char *haystack, int haylen)
3584{
e5574168 3585 int needlen = strlen(needle);
3586 while (1) {
32874aea 3587 /*
3588 * Is it at the start of the string?
3589 */
3590 if (haylen >= needlen && /* haystack is long enough */
3591 !memcmp(needle, haystack, needlen) && /* initial match */
3592 (haylen == needlen || haystack[needlen] == ',')
3593 /* either , or EOS follows */
3594 )
3595 return 1;
3596 /*
3597 * If not, search for the next comma and resume after that.
3598 * If no comma found, terminate.
3599 */
3600 while (haylen > 0 && *haystack != ',')
3601 haylen--, haystack++;
3602 if (haylen == 0)
3603 return 0;
3604 haylen--, haystack++; /* skip over comma itself */
e5574168 3605 }
3606}
3607
3608/*
d39f364a 3609 * SSH2 key creation method.
3610 */
51470298 3611static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
32874aea 3612 char *keyspace)
3613{
d39f364a 3614 SHA_State s;
3615 /* First 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, &chr, 1);
5e0d7cb8 3621 SHA_Bytes(&s, sessid, 20);
d39f364a 3622 SHA_Final(&s, keyspace);
3623 /* Next 20 bytes. */
3624 SHA_Init(&s);
51470298 3625 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3626 sha_mpint(&s, K);
d39f364a 3627 SHA_Bytes(&s, H, 20);
3628 SHA_Bytes(&s, keyspace, 20);
32874aea 3629 SHA_Final(&s, keyspace + 20);
d39f364a 3630}
3631
3632/*
7cca0d81 3633 * Handle the SSH2 transport layer.
e5574168 3634 */
51470298 3635static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3636{
51470298 3637 struct do_ssh2_transport_state {
3638 int nbits, pbits, warn;
3639 Bignum p, g, e, f, K;
3640 int kex_init_value, kex_reply_value;
3641 const struct ssh_mac **maclist;
3642 int nmacs;
3643 const struct ssh2_cipher *cscipher_tobe;
3644 const struct ssh2_cipher *sccipher_tobe;
3645 const struct ssh_mac *csmac_tobe;
3646 const struct ssh_mac *scmac_tobe;
3647 const struct ssh_compress *cscomp_tobe;
3648 const struct ssh_compress *sccomp_tobe;
3649 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3650 int hostkeylen, siglen;
3651 void *hkey; /* actual host key */
3652 unsigned char exchange_hash[20];
3653 int n_preferred_ciphers;
3654 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3655 const struct ssh_compress *preferred_comp;
3656 int first_kex;
3657 };
3658 crState(do_ssh2_transport_state);
3659
3660 crBegin(ssh->do_ssh2_transport_crstate);
3661
3662 s->cscipher_tobe = s->sccipher_tobe = NULL;
3663 s->csmac_tobe = s->scmac_tobe = NULL;
3664 s->cscomp_tobe = s->sccomp_tobe = NULL;
3665
7cca0d81 3666 random_init();
51470298 3667 s->first_kex = 1;
e5574168 3668
51470298 3669 {
3670 int i;
3671 /*
3672 * Set up the preferred ciphers. (NULL => warn below here)
3673 */
3674 s->n_preferred_ciphers = 0;
3675 for (i = 0; i < CIPHER_MAX; i++) {
3676 switch (cfg.ssh_cipherlist[i]) {
3677 case CIPHER_BLOWFISH:
3678 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3679 break;
3680 case CIPHER_DES:
3681 if (cfg.ssh2_des_cbc) {
3682 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3683 }
3684 break;
3685 case CIPHER_3DES:
3686 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3687 break;
3688 case CIPHER_AES:
3689 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3690 break;
3691 case CIPHER_WARN:
3692 /* Flag for later. Don't bother if it's the last in
3693 * the list. */
3694 if (i < CIPHER_MAX - 1) {
3695 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3696 }
3697 break;
ca20bfcf 3698 }
ca20bfcf 3699 }
5e8358ad 3700 }
ca20bfcf 3701
3702 /*
3703 * Set up preferred compression.
3704 */
4ba9b64b 3705 if (cfg.compression)
51470298 3706 s->preferred_comp = &ssh_zlib;
4ba9b64b 3707 else
51470298 3708 s->preferred_comp = &ssh_comp_none;
5e8358ad 3709
7591b9ff 3710 /*
3711 * Be prepared to work around the buggy MAC problem.
3712 */
51470298 3713 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3714 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3715 else
51470298 3716 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3717
32874aea 3718 begin_key_exchange:
51470298 3719 {
3720 int i, j, cipherstr_started;
3721
3722 /*
3723 * Construct and send our key exchange packet.
3724 */
3725 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3726 for (i = 0; i < 16; i++)
3727 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3728 /* List key exchange algorithms. */
3729 ssh2_pkt_addstring_start(ssh);
3730 for (i = 0; i < lenof(kex_algs); i++) {
3731 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3732 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3733 continue;
3734 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3735 if (i < lenof(kex_algs) - 1)
3736 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3737 }
51470298 3738 /* List server host key algorithms. */
3739 ssh2_pkt_addstring_start(ssh);
3740 for (i = 0; i < lenof(hostkey_algs); i++) {
3741 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3742 if (i < lenof(hostkey_algs) - 1)
3743 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3744 }
51470298 3745 /* List client->server encryption algorithms. */
3746 ssh2_pkt_addstring_start(ssh);
3747 cipherstr_started = 0;
3748 for (i = 0; i < s->n_preferred_ciphers; i++) {
3749 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3750 if (!c) continue; /* warning flag */
3751 for (j = 0; j < c->nciphers; j++) {
3752 if (cipherstr_started)
3753 ssh2_pkt_addstring_str(ssh, ",");
3754 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3755 cipherstr_started = 1;
3756 }
3757 }
3758 /* List server->client encryption algorithms. */
3759 ssh2_pkt_addstring_start(ssh);
3760 cipherstr_started = 0;
3761 for (i = 0; i < s->n_preferred_ciphers; i++) {
3762 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3763 if (!c) continue; /* warning flag */
3764 for (j = 0; j < c->nciphers; j++) {
3765 if (cipherstr_started)
3766 ssh2_pkt_addstring_str(ssh, ",");
3767 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3768 cipherstr_started = 1;
3769 }
3770 }
3771 /* List client->server MAC algorithms. */
3772 ssh2_pkt_addstring_start(ssh);
3773 for (i = 0; i < s->nmacs; i++) {
3774 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3775 if (i < s->nmacs - 1)
3776 ssh2_pkt_addstring_str(ssh, ",");
3777 }
3778 /* List server->client MAC algorithms. */
3779 ssh2_pkt_addstring_start(ssh);
3780 for (i = 0; i < s->nmacs; i++) {
3781 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3782 if (i < s->nmacs - 1)
3783 ssh2_pkt_addstring_str(ssh, ",");
3784 }
3785 /* List client->server compression algorithms. */
3786 ssh2_pkt_addstring_start(ssh);
3787 for (i = 0; i < lenof(compressions) + 1; i++) {
3788 const struct ssh_compress *c =
3789 i == 0 ? s->preferred_comp : compressions[i - 1];
3790 ssh2_pkt_addstring_str(ssh, c->name);
3791 if (i < lenof(compressions))
3792 ssh2_pkt_addstring_str(ssh, ",");
3793 }
3794 /* List server->client compression algorithms. */
3795 ssh2_pkt_addstring_start(ssh);
3796 for (i = 0; i < lenof(compressions) + 1; i++) {
3797 const struct ssh_compress *c =
3798 i == 0 ? s->preferred_comp : compressions[i - 1];
3799 ssh2_pkt_addstring_str(ssh, c->name);
3800 if (i < lenof(compressions))
3801 ssh2_pkt_addstring_str(ssh, ",");
3802 }
3803 /* List client->server languages. Empty list. */
3804 ssh2_pkt_addstring_start(ssh);
3805 /* List server->client languages. Empty list. */
3806 ssh2_pkt_addstring_start(ssh);
3807 /* First KEX packet does _not_ follow, because we're not that brave. */
3808 ssh2_pkt_addbool(ssh, FALSE);
3809 /* Reserved. */
3810 ssh2_pkt_adduint32(ssh, 0);
e5574168 3811 }
0db56f73 3812
51470298 3813 ssh->exhash = ssh->exhashbase;
3814 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 3815
51470298 3816 ssh2_pkt_send(ssh);
e5574168 3817
32874aea 3818 if (!ispkt)
3819 crWaitUntil(ispkt);
51470298 3820 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 3821
3822 /*
3823 * Now examine the other side's KEXINIT to see what we're up
3824 * to.
3825 */
51470298 3826 {
3827 char *str;
3828 int i, j, len;
3829
3830 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
a8327734 3831 bombout((ssh,"expected key exchange packet from server"));
51470298 3832 crReturn(0);
32874aea 3833 }
51470298 3834 ssh->kex = NULL;
3835 ssh->hostkey = NULL;
3836 s->cscipher_tobe = NULL;
3837 s->sccipher_tobe = NULL;
3838 s->csmac_tobe = NULL;
3839 s->scmac_tobe = NULL;
3840 s->cscomp_tobe = NULL;
3841 s->sccomp_tobe = NULL;
3842 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3843 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3844 for (i = 0; i < lenof(kex_algs); i++) {
3845 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3846 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3847 continue;
3848 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3849 ssh->kex = kex_algs[i];
3850 break;
3851 }
32874aea 3852 }
51470298 3853 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3854 for (i = 0; i < lenof(hostkey_algs); i++) {
3855 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3856 ssh->hostkey = hostkey_algs[i];
3857 break;
3858 }
3859 }
3860 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3861 s->warn = 0;
3862 for (i = 0; i < s->n_preferred_ciphers; i++) {
3863 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3864 if (!c) {
3865 s->warn = 1;
3866 } else {
3867 for (j = 0; j < c->nciphers; j++) {
3868 if (in_commasep_string(c->list[j]->name, str, len)) {
3869 s->cscipher_tobe = c->list[j];
3870 break;
3871 }
ca20bfcf 3872 }
32874aea 3873 }
51470298 3874 if (s->cscipher_tobe) {
3875 if (s->warn)
a8327734 3876 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 3877 break;
3878 }
32874aea 3879 }
51470298 3880 if (!s->cscipher_tobe) {
a8327734 3881 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)", str));
51470298 3882 crReturn(0);
ca20bfcf 3883 }
0ef8f407 3884
51470298 3885 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3886 s->warn = 0;
3887 for (i = 0; i < s->n_preferred_ciphers; i++) {
3888 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3889 if (!c) {
3890 s->warn = 1;
3891 } else {
3892 for (j = 0; j < c->nciphers; j++) {
3893 if (in_commasep_string(c->list[j]->name, str, len)) {
3894 s->sccipher_tobe = c->list[j];
3895 break;
3896 }
ca20bfcf 3897 }
32874aea 3898 }
51470298 3899 if (s->sccipher_tobe) {
3900 if (s->warn)
a8327734 3901 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 3902 break;
3903 }
32874aea 3904 }
51470298 3905 if (!s->sccipher_tobe) {
a8327734 3906 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)", str));
51470298 3907 crReturn(0);
ca20bfcf 3908 }
0ef8f407 3909
51470298 3910 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3911 for (i = 0; i < s->nmacs; i++) {
3912 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3913 s->csmac_tobe = s->maclist[i];
3914 break;
3915 }
32874aea 3916 }
51470298 3917 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3918 for (i = 0; i < s->nmacs; i++) {
3919 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3920 s->scmac_tobe = s->maclist[i];
3921 break;
3922 }
32874aea 3923 }
51470298 3924 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3925 for (i = 0; i < lenof(compressions) + 1; i++) {
3926 const struct ssh_compress *c =
3927 i == 0 ? s->preferred_comp : compressions[i - 1];
3928 if (in_commasep_string(c->name, str, len)) {
3929 s->cscomp_tobe = c;
3930 break;
3931 }
32874aea 3932 }
51470298 3933 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3934 for (i = 0; i < lenof(compressions) + 1; i++) {
3935 const struct ssh_compress *c =
3936 i == 0 ? s->preferred_comp : compressions[i - 1];
3937 if (in_commasep_string(c->name, str, len)) {
3938 s->sccomp_tobe = c;
3939 break;
3940 }
32874aea 3941 }
e5574168 3942 }
e5574168 3943
3944 /*
7bd5a860 3945 * Work out the number of bits of key we will need from the key
3946 * exchange. We start with the maximum key length of either
3947 * cipher...
3948 */
3949 {
32874aea 3950 int csbits, scbits;
7bd5a860 3951
51470298 3952 csbits = s->cscipher_tobe->keylen;
3953 scbits = s->sccipher_tobe->keylen;
3954 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 3955 }
3956 /* The keys only have 160-bit entropy, since they're based on
3957 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 3958 if (s->nbits > 160)
3959 s->nbits = 160;
7bd5a860 3960
3961 /*
a92dd380 3962 * If we're doing Diffie-Hellman group exchange, start by
3963 * requesting a group.
e5574168 3964 */
51470298 3965 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 3966 logevent("Doing Diffie-Hellman group exchange");
51470298 3967 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3968 /*
3969 * Work out how big a DH group we will need to allow that
3970 * much data.
7bd5a860 3971 */
51470298 3972 s->pbits = 512 << ((s->nbits - 1) / 64);
3973 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3974 ssh2_pkt_adduint32(ssh, s->pbits);
3975 ssh2_pkt_send(ssh);
32874aea 3976
3977 crWaitUntil(ispkt);
51470298 3978 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
a8327734 3979 bombout((ssh,"expected key exchange group packet from server"));
32874aea 3980 crReturn(0);
3981 }
51470298 3982 s->p = ssh2_pkt_getmp(ssh);
3983 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 3984 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 3985 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3986 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3987 } else {
51470298 3988 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 3989 ssh->kex_ctx = dh_setup_group1();
51470298 3990 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3991 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3992 }
e5574168 3993
a92dd380 3994 logevent("Doing Diffie-Hellman key exchange");
e5574168 3995 /*
a92dd380 3996 * Now generate and send e for Diffie-Hellman.
e5574168 3997 */
27cd7fc2 3998 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 3999 ssh2_pkt_init(ssh, s->kex_init_value);
4000 ssh2_pkt_addmp(ssh, s->e);
4001 ssh2_pkt_send(ssh);
e5574168 4002
4003 crWaitUntil(ispkt);
51470298 4004 if (ssh->pktin.type != s->kex_reply_value) {
a8327734 4005 bombout((ssh,"expected key exchange reply packet from server"));
32874aea 4006 crReturn(0);
7cca0d81 4007 }
51470298 4008 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4009 s->f = ssh2_pkt_getmp(ssh);
4010 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4011
27cd7fc2 4012 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4013
51470298 4014 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4015 if (ssh->kex == &ssh_diffiehellman_gex) {
4016 sha_uint32(&ssh->exhash, s->pbits);
4017 sha_mpint(&ssh->exhash, s->p);
4018 sha_mpint(&ssh->exhash, s->g);
a92dd380 4019 }
51470298 4020 sha_mpint(&ssh->exhash, s->e);
4021 sha_mpint(&ssh->exhash, s->f);
4022 sha_mpint(&ssh->exhash, s->K);
4023 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4024
27cd7fc2 4025 dh_cleanup(ssh->kex_ctx);
3709bfe9 4026
7cca0d81 4027#if 0
765c4200 4028 debug(("Exchange hash is:\n"));
51470298 4029 dmemdump(s->exchange_hash, 20);
7cca0d81 4030#endif
4031
51470298 4032 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4033 if (!s->hkey ||
4034 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4035 s->exchange_hash, 20)) {
a8327734 4036 bombout((ssh,"Server's host key did not match the signature supplied"));
32874aea 4037 crReturn(0);
8d5de777 4038 }
e5574168 4039
4040 /*
7cca0d81 4041 * Authenticate remote host: verify host key. (We've already
4042 * checked the signature of the exchange hash.)
e5574168 4043 */
51470298 4044 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4045 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4046 verify_ssh_host_key(ssh->frontend,
4047 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4048 s->keystr, s->fingerprint);
4049 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4050 logevent("Host key fingerprint is:");
51470298 4051 logevent(s->fingerprint);
5e0d7cb8 4052 }
51470298 4053 sfree(s->fingerprint);
4054 sfree(s->keystr);
4055 ssh->hostkey->freekey(s->hkey);
d39f364a 4056
4057 /*
7cca0d81 4058 * Send SSH2_MSG_NEWKEYS.
d39f364a 4059 */
51470298 4060 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4061 ssh2_pkt_send(ssh);
d39f364a 4062
4063 /*
8406eaf9 4064 * Expect SSH2_MSG_NEWKEYS from server.
4065 */
4066 crWaitUntil(ispkt);
51470298 4067 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
a8327734 4068 bombout((ssh,"expected new-keys packet from server"));
8406eaf9 4069 crReturn(0);
4070 }
4071
4072 /*
d39f364a 4073 * Create and initialise session keys.
4074 */
371e569c 4075 if (ssh->cs_cipher_ctx)
4076 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4077 ssh->cscipher = s->cscipher_tobe;
371e569c 4078 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4079
371e569c 4080 if (ssh->sc_cipher_ctx)
4081 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4082 ssh->sccipher = s->sccipher_tobe;
371e569c 4083 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4084
4085 if (ssh->cs_mac_ctx)
4086 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4087 ssh->csmac = s->csmac_tobe;
e0e1a00d 4088 ssh->cs_mac_ctx = ssh->csmac->make_context();
4089
4090 if (ssh->sc_mac_ctx)
4091 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4092 ssh->scmac = s->scmac_tobe;
e0e1a00d 4093 ssh->sc_mac_ctx = ssh->scmac->make_context();
4094
5366aed8 4095 if (ssh->cs_comp_ctx)
4096 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4097 ssh->cscomp = s->cscomp_tobe;
5366aed8 4098 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4099
4100 if (ssh->sc_comp_ctx)
4101 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4102 ssh->sccomp = s->sccomp_tobe;
5366aed8 4103 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4104
d39f364a 4105 /*
5e0d7cb8 4106 * Set IVs after keys. Here we use the exchange hash from the
4107 * _first_ key exchange.
d39f364a 4108 */
51470298 4109 {
4110 unsigned char keyspace[40];
4111 if (s->first_kex)
4112 memcpy(ssh->v2_session_id, s->exchange_hash,
4113 sizeof(s->exchange_hash));
4114 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4115 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4116 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4117 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4118 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4119 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4120 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4121 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4122 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4123 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4124 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4125 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4126 }
371e569c 4127 {
4128 char buf[256];
4129 sprintf(buf, "Initialised %.200s client->server encryption",
4130 ssh->cscipher->text_name);
4131 logevent(buf);
4132 sprintf(buf, "Initialised %.200s server->client encryption",
4133 ssh->sccipher->text_name);
4134 logevent(buf);
5366aed8 4135 if (ssh->cscomp->text_name) {
4136 sprintf(buf, "Initialised %.200s compression",
4137 ssh->cscomp->text_name);
4138 logevent(buf);
4139 }
4140 if (ssh->sccomp->text_name) {
4141 sprintf(buf, "Initialised %.200s decompression",
4142 ssh->sccomp->text_name);
4143 logevent(buf);
4144 }
371e569c 4145 }
4146
d39f364a 4147
033b4cef 4148 /*
0db56f73 4149 * If this is the first key exchange phase, we must pass the
4150 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4151 * wants to see it but because it will need time to initialise
4152 * itself before it sees an actual packet. In subsequent key
4153 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4154 * it would only confuse the layer above.
4155 */
51470298 4156 if (!s->first_kex) {
32874aea 4157 crReturn(0);
0db56f73 4158 }
51470298 4159 s->first_kex = 0;
0db56f73 4160
4161 /*
7cca0d81 4162 * Now we're encrypting. Begin returning 1 to the protocol main
4163 * function so that other things can run on top of the
4164 * transport. If we ever see a KEXINIT, we must go back to the
4165 * start.
033b4cef 4166 */
51470298 4167 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4168 crReturn(1);
e96adf72 4169 }
5e0d7cb8 4170 logevent("Server initiated key re-exchange");
7cca0d81 4171 goto begin_key_exchange;
e5574168 4172
4173 crFinish(1);
4174}
4175
7cca0d81 4176/*
783415f8 4177 * Add data to an SSH2 channel output buffer.
4178 */
32874aea 4179static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4180 int len)
4181{
5471d09a 4182 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4183}
4184
4185/*
4186 * Attempt to send data on an SSH2 channel.
4187 */
5471d09a 4188static int ssh2_try_send(struct ssh_channel *c)
32874aea 4189{
51470298 4190 Ssh ssh = c->ssh;
4191
5471d09a 4192 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4193 int len;
4194 void *data;
4195 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4196 if ((unsigned)len > c->v.v2.remwindow)
4197 len = c->v.v2.remwindow;
4198 if ((unsigned)len > c->v.v2.remmaxpkt)
4199 len = c->v.v2.remmaxpkt;
51470298 4200 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4201 ssh2_pkt_adduint32(ssh, c->remoteid);
4202 ssh2_pkt_addstring_start(ssh);
4203 ssh2_pkt_addstring_data(ssh, data, len);
4204 ssh2_pkt_send(ssh);
5471d09a 4205 bufchain_consume(&c->v.v2.outbuffer, len);
4206 c->v.v2.remwindow -= len;
4207 }
4208
4209 /*
4210 * After having sent as much data as we can, return the amount
4211 * still buffered.
4212 */
4213 return bufchain_size(&c->v.v2.outbuffer);
4214}
4215
4216/*
4217 * Potentially enlarge the window on an SSH2 channel.
4218 */
4219static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4220{
51470298 4221 Ssh ssh = c->ssh;
4222
6b69f42e 4223 /*
4224 * Never send WINDOW_ADJUST for a channel that the remote side
4225 * already thinks it's closed; there's no point, since it won't
4226 * be sending any more data anyway.
4227 */
4228 if (c->closes != 0)
4229 return;
4230
5471d09a 4231 if (newwin > c->v.v2.locwindow) {
51470298 4232 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4233 ssh2_pkt_adduint32(ssh, c->remoteid);
4234 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4235 ssh2_pkt_send(ssh);
5471d09a 4236 c->v.v2.locwindow = newwin;
783415f8 4237 }
4238}
4239
4240/*
7cca0d81 4241 * Handle the SSH2 userauth and connection layers.
4242 */
51470298 4243static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4244{
51470298 4245 struct do_ssh2_authconn_state {
4246 enum {
4247 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4248 AUTH_PASSWORD,
4249 AUTH_KEYBOARD_INTERACTIVE
4250 } method;
4251 enum {
4252 AUTH_TYPE_NONE,
4253 AUTH_TYPE_PUBLICKEY,
4254 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4255 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4256 AUTH_TYPE_PASSWORD,
4257 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4258 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4259 } type;
4260 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4261 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4262 int kbd_inter_running;
4263 int we_are_in;
4264 int num_prompts, curr_prompt, echo;
4265 char username[100];
4266 int got_username;
4267 char pwprompt[200];
4268 char password[100];
4269 void *publickey_blob;
4270 int publickey_bloblen;
4271 unsigned char request[5], *response, *p;
4272 int responselen;
4273 int keyi, nkeys;
4274 int authed;
4275 char *pkblob, *alg, *commentp;
4276 int pklen, alglen, commentlen;
4277 int siglen, retlen, len;
4278 char *q, *agentreq, *ret;
4279 int try_send;
4280 };
4281 crState(do_ssh2_authconn_state);
4282
4283 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4284
7cca0d81 4285 /*
4286 * Request userauth protocol, and await a response to it.
4287 */
51470298 4288 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4289 ssh2_pkt_addstring(ssh, "ssh-userauth");
4290 ssh2_pkt_send(ssh);
7cca0d81 4291 crWaitUntilV(ispkt);
51470298 4292 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
a8327734 4293 bombout((ssh,"Server refused user authentication protocol"));
32874aea 4294 crReturnV;
8d5de777 4295 }
7cca0d81 4296
4297 /*
1408a877 4298 * We repeat this whole loop, including the username prompt,
4299 * until we manage a successful authentication. If the user
51470298 4300 * types the wrong _password_, they can be sent back to the
4301 * beginning to try another username, if this is configured on.
4302 * (If they specify a username in the config, they are never
4303 * asked, even if they do give a wrong password.)
1408a877 4304 *
4305 * I think this best serves the needs of
4306 *
4307 * - the people who have no configuration, no keys, and just
4308 * want to try repeated (username,password) pairs until they
4309 * type both correctly
4310 *
4311 * - people who have keys and configuration but occasionally
4312 * need to fall back to passwords
4313 *
4314 * - people with a key held in Pageant, who might not have
4315 * logged in to a particular machine before; so they want to
4316 * type a username, and then _either_ their key will be
4317 * accepted, _or_ they will type a password. If they mistype
4318 * the username they will want to be able to get back and
4319 * retype it!
7cca0d81 4320 */
51470298 4321 s->username[0] = '\0';
4322 s->got_username = FALSE;
1408a877 4323 do {
1408a877 4324 /*
4325 * Get a username.
4326 */
51470298 4327 if (s->got_username && !cfg.change_username) {
5bb641e1 4328 /*
4329 * We got a username last time round this loop, and
4330 * with change_username turned off we don't try to get
4331 * it again.
4332 */
4333 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4334 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4335 if (!ssh_get_line("login as: ",
51470298 4336 s->username, sizeof(s->username), FALSE)) {
32874aea 4337 /*
4338 * get_line failed to get a username.
4339 * Terminate.
4340 */
4341 logevent("No username provided. Abandoning session.");
51470298 4342 ssh->state = SSH_STATE_CLOSED;
32874aea 4343 crReturnV;
4344 }
4345 } else {
51470298 4346 int ret; /* need not be saved across crReturn */
4347 c_write_str(ssh, "login as: ");
4348 ssh->send_ok = 1;
4349 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4350 do {
32874aea 4351 crWaitUntilV(!ispkt);
51470298 4352 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4353 } while (ret == 0);
4354 if (ret < 0)
4355 cleanup_exit(0);
32874aea 4356 }
51470298 4357 c_write_str(ssh, "\r\n");
4358 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4359 } else {
4360 char stuff[200];
51470298 4361 strncpy(s->username, cfg.username, sizeof(s->username));
4362 s->username[sizeof(s->username)-1] = '\0';
65a22376 4363 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
51470298 4364 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4365 c_write_str(ssh, stuff);
7cca0d81 4366 }
4367 }
51470298 4368 s->got_username = TRUE;
7cca0d81 4369
65a22376 4370 /*
1408a877 4371 * Send an authentication request using method "none": (a)
4372 * just in case it succeeds, and (b) so that we know what
4373 * authentication methods we can usefully try next.
65a22376 4374 */
51470298 4375 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4376
4377 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4378 ssh2_pkt_addstring(ssh, s->username);
4379 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4380 ssh2_pkt_addstring(ssh, "none"); /* method */
4381 ssh2_pkt_send(ssh);
4382 s->type = AUTH_TYPE_NONE;
4383 s->gotit = FALSE;
4384 s->we_are_in = FALSE;
4385
4386 s->tried_pubkey_config = FALSE;
4387 s->tried_agent = FALSE;
4388 s->tried_keyb_inter = FALSE;
4389 s->kbd_inter_running = FALSE;
396778f1 4390 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4391 if (*cfg.keyfile) {
231ee168 4392 int keytype;
a8327734 4393 logeventf(ssh->frontend,
4394 "Reading private key file \"%.150s\"", cfg.keyfile);
231ee168 4395 keytype = key_type(cfg.keyfile);
51470298 4396 if (keytype == SSH_KEYTYPE_SSH2) {
4397 s->publickey_blob =
4398 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4399 &s->publickey_bloblen);
4400 } else {
231ee168 4401 char msgbuf[256];
a8327734 4402 logeventf(ssh->frontend,
4403 "Unable to use this key file (%s)",
4404 key_type_to_str(keytype));
231ee168 4405 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4406 cfg.keyfile, key_type_to_str(keytype));
51470298 4407 c_write_str(ssh, msgbuf);
4408 s->publickey_blob = NULL;
231ee168 4409 }
396778f1 4410 } else
51470298 4411 s->publickey_blob = NULL;
65a22376 4412
1408a877 4413 while (1) {
4414 /*
4415 * Wait for the result of the last authentication request.
4416 */
51470298 4417 if (!s->gotit)
1408a877 4418 crWaitUntilV(ispkt);
51470298 4419 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4420 char *banner;
4421 int size;
4422 /*
4423 * Don't show the banner if we're operating in
4424 * non-verbose non-interactive mode. (It's probably
4425 * a script, which means nobody will read the
4426 * banner _anyway_, and moreover the printing of
4427 * the banner will screw up processing on the
4428 * output of (say) plink.)
4429 */
4430 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4431 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4432 if (banner)
51470298 4433 c_write_untrusted(ssh, banner, size);
32874aea 4434 }
1408a877 4435 crWaitUntilV(ispkt);
4436 }
51470298 4437 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4438 logevent("Access granted");
51470298 4439 s->we_are_in = TRUE;
1408a877 4440 break;
4441 }
65a22376 4442
51470298 4443 if (s->kbd_inter_running &&
4444 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4445 /*
45068b27 4446 * This is either a further set-of-prompts packet
4447 * in keyboard-interactive authentication, or it's
4448 * the same one and we came back here with `gotit'
4449 * set. In the former case, we must reset the
4450 * curr_prompt variable.
b3186d64 4451 */
51470298 4452 if (!s->gotit)
4453 s->curr_prompt = 0;
4454 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
a8327734 4455 bombout((ssh,"Strange packet received during authentication: type %d",
51470298 4456 ssh->pktin.type));
38c4a8da 4457 crReturnV;
65a22376 4458 }
4459
51470298 4460 s->gotit = FALSE;
65a22376 4461
1408a877 4462 /*
4463 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4464 * we can look at the string in it and know what we can
4465 * helpfully try next.
4466 */
51470298 4467 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4468 char *methods;
4469 int methlen;
51470298 4470 ssh2_pkt_getstring(ssh, &methods, &methlen);
4471 s->kbd_inter_running = FALSE;
4472 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4473 /*
4474 * We have received an unequivocal Access
4475 * Denied. This can translate to a variety of
4476 * messages:
4477 *
4478 * - if we'd just tried "none" authentication,
4479 * it's not worth printing anything at all
4480 *
4481 * - if we'd just tried a public key _offer_,
4482 * the message should be "Server refused our
4483 * key" (or no message at all if the key
4484 * came from Pageant)
4485 *
4486 * - if we'd just tried anything else, the
4487 * message really should be "Access denied".
4488 *
4489 * Additionally, if we'd just tried password
4490 * authentication, we should break out of this
4491 * whole loop so as to go back to the username
4492 * prompt.
4493 */
51470298 4494 if (s->type == AUTH_TYPE_NONE) {
1408a877 4495 /* do nothing */
51470298 4496 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4497 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4498 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4499 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4500 logevent("Server refused public key");
51470298 4501 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4502 /* server declined keyboard-interactive; ignore */
1408a877 4503 } else {
51470298 4504 c_write_str(ssh, "Access denied\r\n");
1408a877 4505 logevent("Access denied");
51470298 4506 if (s->type == AUTH_TYPE_PASSWORD) {
4507 s->we_are_in = FALSE;
1408a877 4508 break;
4509 }
4510 }
4511 } else {
51470298 4512 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4513 logevent("Further authentication required");
4514 }
65a22376 4515
51470298 4516 s->can_pubkey =
32874aea 4517 in_commasep_string("publickey", methods, methlen);
51470298 4518 s->can_passwd =
32874aea 4519 in_commasep_string("password", methods, methlen);
51470298 4520 s->can_keyb_inter = cfg.try_ki_auth &&
761187b6 4521 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4522 }
65a22376 4523
51470298 4524 s->method = 0;
4525 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4526
0405e71f 4527 /*
4528 * Most password/passphrase prompts will be
4529 * non-echoing, so we set this to 0 by default.
4530 * Exception is that some keyboard-interactive prompts
4531 * can be echoing, in which case we'll set this to 1.
4532 */
51470298 4533 s->echo = 0;
0405e71f 4534
51470298 4535 if (!s->method && s->can_pubkey &&
4536 agent_exists() && !s->tried_agent) {
1983e559 4537 /*
4538 * Attempt public-key authentication using Pageant.
4539 */
1983e559 4540 void *r;
51470298 4541 s->authed = FALSE;
1983e559 4542
51470298 4543 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4544 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4545
51470298 4546 s->tried_agent = TRUE;
1983e559 4547
4548 logevent("Pageant is running. Requesting keys.");
4549
4550 /* Request the keys held by the agent. */
51470298 4551 PUT_32BIT(s->request, 1);
4552 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4553 agent_query(s->request, 5, &r, &s->responselen);
4554 s->response = (unsigned char *) r;
4555 if (s->response && s->responselen >= 5 &&
4556 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4557 s->p = s->response + 5;
4558 s->nkeys = GET_32BIT(s->p);
4559 s->p += 4;
32874aea 4560 {
4561 char buf[64];
51470298 4562 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4563 logevent(buf);
4564 }
51470298 4565 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4566 void *vret;
1983e559 4567
32874aea 4568 {
4569 char buf[64];
51470298 4570 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4571 logevent(buf);
4572 }
51470298 4573 s->pklen = GET_32BIT(s->p);
4574 s->p += 4;
4575 if (s->publickey_blob &&
4576 s->pklen == s->publickey_bloblen &&
4577 !memcmp(s->p, s->publickey_blob,
4578 s->publickey_bloblen)) {
396778f1 4579 logevent("This key matches configured key file");
51470298 4580 s->tried_pubkey_config = 1;
396778f1 4581 }
51470298 4582 s->pkblob = s->p;
4583 s->p += s->pklen;
4584 s->alglen = GET_32BIT(s->pkblob);
4585 s->alg = s->pkblob + 4;
4586 s->commentlen = GET_32BIT(s->p);
4587 s->p += 4;
4588 s->commentp = s->p;
4589 s->p += s->commentlen;
4590 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4591 ssh2_pkt_addstring(ssh, s->username);
4592 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4593 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4594 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4595 ssh2_pkt_addstring_start(ssh);
4596 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4597 ssh2_pkt_addstring_start(ssh);
4598 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4599 ssh2_pkt_send(ssh);
1983e559 4600
4601 crWaitUntilV(ispkt);
51470298 4602 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4603 logevent("Key refused");
4604 continue;
4605 }
4606
32874aea 4607 if (flags & FLAG_VERBOSE) {
51470298 4608 c_write_str(ssh, "Authenticating with "
4609 "public key \"");
4610 c_write(ssh, s->commentp, s->commentlen);
4611 c_write_str(ssh, "\" from agent\r\n");
32874aea 4612 }
1983e559 4613
4614 /*
4615 * Server is willing to accept the key.
4616 * Construct a SIGN_REQUEST.
4617 */
51470298 4618 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4619 ssh2_pkt_addstring(ssh, s->username);
4620 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4621 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4622 ssh2_pkt_addbool(ssh, TRUE);
4623 ssh2_pkt_addstring_start(ssh);
4624 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4625 ssh2_pkt_addstring_start(ssh);
4626 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4627
4628 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4629 s->len = 1; /* message type */
4630 s->len += 4 + s->pklen; /* key blob */
4631 s->len += 4 + s->siglen; /* data to sign */
4632 s->len += 4; /* flags */
4633 s->agentreq = smalloc(4 + s->len);
4634 PUT_32BIT(s->agentreq, s->len);
4635 s->q = s->agentreq + 4;
4636 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4637 PUT_32BIT(s->q, s->pklen);
4638 s->q += 4;
4639 memcpy(s->q, s->pkblob, s->pklen);
4640 s->q += s->pklen;
4641 PUT_32BIT(s->q, s->siglen);
4642 s->q += 4;
1983e559 4643 /* Now the data to be signed... */
51470298 4644 PUT_32BIT(s->q, 20);
4645 s->q += 4;
4646 memcpy(s->q, ssh->v2_session_id, 20);
4647 s->q += 20;
4648 memcpy(s->q, ssh->pktout.data + 5,
4649 ssh->pktout.length - 5);
4650 s->q += ssh->pktout.length - 5;
1983e559 4651 /* And finally the (zero) flags word. */
51470298 4652 PUT_32BIT(s->q, 0);
4653 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4654 s->ret = vret;
4655 sfree(s->agentreq);
4656 if (s->ret) {
4657 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4658 logevent("Sending Pageant's response");
51470298 4659 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4660 s->ret + 9,
4661 GET_32BIT(s->ret + 5));
4662 ssh2_pkt_send(ssh);
4663 s->authed = TRUE;
1983e559 4664 break;
4665 } else {
32874aea 4666 logevent
4667 ("Pageant failed to answer challenge");
51470298 4668 sfree(s->ret);
1983e559 4669 }
4670 }
4671 }
51470298 4672 if (s->authed)
1983e559 4673 continue;
4674 }
4675 }
4676
51470298 4677 if (!s->method && s->can_pubkey && s->publickey_blob
4678 && !s->tried_pubkey_config) {
1408a877 4679 unsigned char *pub_blob;
4680 char *algorithm, *comment;
4681 int pub_blob_len;
65a22376 4682
51470298 4683 s->tried_pubkey_config = TRUE;
65a22376 4684
51470298 4685 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4686 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4687
65a22376 4688 /*
1408a877 4689 * Try the public key supplied in the configuration.
4690 *
4691 * First, offer the public blob to see if the server is
4692 * willing to accept it.
65a22376 4693 */
1408a877 4694 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4695 &pub_blob_len);
4696 if (pub_blob) {
51470298 4697 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4698 ssh2_pkt_addstring(ssh, s->username);
4699 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4700 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4701 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4702 ssh2_pkt_addstring(ssh, algorithm);
4703 ssh2_pkt_addstring_start(ssh);
4704 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4705 ssh2_pkt_send(ssh);
32874aea 4706 logevent("Offered public key"); /* FIXME */
1408a877 4707
4708 crWaitUntilV(ispkt);
51470298 4709 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4710 s->gotit = TRUE;
4711 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4712 continue; /* key refused; give up on it */
1408a877 4713 }
65a22376 4714
1408a877 4715 logevent("Offer of public key accepted");
65a22376 4716 /*
1408a877 4717 * Actually attempt a serious authentication using
4718 * the key.
65a22376 4719 */
1408a877 4720 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
51470298 4721 sprintf(s->pwprompt,
32874aea 4722 "Passphrase for key \"%.100s\": ",
4723 comment);
51470298 4724 s->need_pw = TRUE;
1408a877 4725 } else {
51470298 4726 s->need_pw = FALSE;
1408a877 4727 }
51470298 4728 c_write_str(ssh, "Authenticating with public key \"");
4729 c_write_str(ssh, comment);
4730 c_write_str(ssh, "\"\r\n");
4731 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4732 }
1408a877 4733 }
4734
51470298 4735 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4736 s->method = AUTH_KEYBOARD_INTERACTIVE;
4737 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4738 s->tried_keyb_inter = TRUE;
af659722 4739
51470298 4740 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4741 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4742
51470298 4743 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4744 ssh2_pkt_addstring(ssh, s->username);
4745 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4746 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4747 ssh2_pkt_addstring(ssh, ""); /* lang */
4748 ssh2_pkt_addstring(ssh, "");
4749 ssh2_pkt_send(ssh);
af659722 4750
4751 crWaitUntilV(ispkt);
51470298 4752 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4753 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4754 s->gotit = TRUE;
af659722 4755 logevent("Keyboard-interactive authentication refused");
51470298 4756 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4757 continue;
4758 }
4759
51470298 4760 s->kbd_inter_running = TRUE;
4761 s->curr_prompt = 0;
af659722 4762 }
4763
51470298 4764 if (s->kbd_inter_running) {
4765 s->method = AUTH_KEYBOARD_INTERACTIVE;
4766 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4767 s->tried_keyb_inter = TRUE;
af659722 4768
51470298 4769 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4770 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4771
51470298 4772 if (s->curr_prompt == 0) {
45068b27 4773 /*
4774 * We've got a fresh USERAUTH_INFO_REQUEST.
4775 * Display header data, and start going through
4776 * the prompts.
4777 */
4778 char *name, *inst, *lang;
4779 int name_len, inst_len, lang_len;
4780
51470298 4781 ssh2_pkt_getstring(ssh, &name, &name_len);
4782 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4783 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 4784 if (name_len > 0) {
51470298 4785 c_write_untrusted(ssh, name, name_len);
4786 c_write_str(ssh, "\r\n");
45068b27 4787 }
4788 if (inst_len > 0) {
51470298 4789 c_write_untrusted(ssh, inst, inst_len);
4790 c_write_str(ssh, "\r\n");
45068b27 4791 }
51470298 4792 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 4793 }
af659722 4794
45068b27 4795 /*
4796 * If there are prompts remaining in the packet,
4797 * display one and get a response.
4798 */
51470298 4799 if (s->curr_prompt < s->num_prompts) {
45068b27 4800 char *prompt;
4801 int prompt_len;
af659722 4802
51470298 4803 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 4804 if (prompt_len > 0) {
51470298 4805 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4806 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4807 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 4808 } else {
51470298 4809 strcpy(s->pwprompt,
45068b27 4810 "<server failed to send prompt>: ");
4811 }
51470298 4812 s->echo = ssh2_pkt_getbool(ssh);
4813 s->need_pw = TRUE;
45068b27 4814 } else
51470298 4815 s->need_pw = FALSE;
af659722 4816 }
4817
51470298 4818 if (!s->method && s->can_passwd) {
4819 s->method = AUTH_PASSWORD;
4820 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4821 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4822 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4823 ssh->savedhost);
4824 s->need_pw = TRUE;
1408a877 4825 }
4826
51470298 4827 if (s->need_pw) {
fa17a66e 4828 if (ssh_get_line) {
51470298 4829 if (!ssh_get_line(s->pwprompt, s->password,
4830 sizeof(s->password), TRUE)) {
1408a877 4831 /*
fa17a66e 4832 * get_line failed to get a password (for
4833 * example because one was supplied on the
4834 * command line which has already failed to
4835 * work). Terminate.
1408a877 4836 */
51470298 4837 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4838 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4839 ssh2_pkt_addstring(ssh, "No more passwords available"
4840 " to try");
4841 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4842 ssh2_pkt_send(ssh);
247308b5 4843 logevent("Unable to authenticate");
a8327734 4844 connection_fatal(ssh->frontend,
4845 "Unable to authenticate");
51470298 4846 ssh->state = SSH_STATE_CLOSED;
1408a877 4847 crReturnV;
4848 }
4849 } else {
51470298 4850 int ret; /* need not be saved across crReturn */
4851 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4852 ssh->send_ok = 1;
1408a877 4853
51470298 4854 setup_userpass_input(ssh, s->password,
4855 sizeof(s->password), s->echo);
0405e71f 4856 do {
1408a877 4857 crWaitUntilV(!ispkt);
51470298 4858 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4859 } while (ret == 0);
4860 if (ret < 0)
4861 cleanup_exit(0);
51470298 4862 c_write_str(ssh, "\r\n");
65a22376 4863 }
65a22376 4864 }
65a22376 4865
51470298 4866 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 4867 /*
4868 * We have our passphrase. Now try the actual authentication.
4869 */
4870 struct ssh2_userkey *key;
65a22376 4871
51470298 4872 key = ssh2_load_userkey(cfg.keyfile, s->password);
1408a877 4873 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4874 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 4875 c_write_str(ssh, "Wrong passphrase\r\n");
4876 s->tried_pubkey_config = FALSE;
1408a877 4877 } else {
51470298 4878 c_write_str(ssh, "Unable to load private key\r\n");
4879 s->tried_pubkey_config = TRUE;
1408a877 4880 }
4881 /* Send a spurious AUTH_NONE to return to the top. */
51470298 4882 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4883 ssh2_pkt_addstring(ssh, s->username);
4884 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4885 ssh2_pkt_addstring(ssh, "none"); /* method */
4886 ssh2_pkt_send(ssh);
4887 s->type = AUTH_TYPE_NONE;
1408a877 4888 } else {
1dd353b5 4889 unsigned char *pkblob, *sigblob, *sigdata;
4890 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4891
1408a877 4892 /*
4893 * We have loaded the private key and the server
4894 * has announced that it's willing to accept it.
4895 * Hallelujah. Generate a signature and send it.
4896 */
51470298 4897 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4898 ssh2_pkt_addstring(ssh, s->username);
4899 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4900 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4901 ssh2_pkt_addbool(ssh, TRUE);
4902 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 4903 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 4904 ssh2_pkt_addstring_start(ssh);
4905 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
1408a877 4906
4907 /*
4908 * The data to be signed is:
4909 *
4910 * string session-id
4911 *
4912 * followed by everything so far placed in the
4913 * outgoing packet.
4914 */
51470298 4915 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
1408a877 4916 sigdata = smalloc(sigdata_len);
4917 PUT_32BIT(sigdata, 20);
51470298 4918 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4919 memcpy(sigdata + 24, ssh->pktout.data + 5,
4920 ssh->pktout.length - 5);
1dd353b5 4921 sigblob = key->alg->sign(key->data, sigdata,
4922 sigdata_len, &sigblob_len);
51470298 4923 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 4924 sigblob, sigblob_len);
4925 sfree(pkblob);
4926 sfree(sigblob);
1408a877 4927 sfree(sigdata);
4928
51470298 4929 ssh2_pkt_send(ssh);
4930 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 4931 }
51470298 4932 } else if (s->method == AUTH_PASSWORD) {
65a22376 4933 /*
1408a877 4934 * We send the password packet lumped tightly together with
4935 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4936 * string long enough to make the total length of the two
4937 * packets constant. This should ensure that a passive
4938 * listener doing traffic analyis can't work out the length
4939 * of the password.
4940 *
4941 * For this to work, we need an assumption about the
4942 * maximum length of the password packet. I think 256 is
4943 * pretty conservative. Anyone using a password longer than
4944 * that probably doesn't have much to worry about from
4945 * people who find out how long their password is!
65a22376 4946 */
51470298 4947 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4948 ssh2_pkt_addstring(ssh, s->username);
4949 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4950 ssh2_pkt_addstring(ssh, "password");
4951 ssh2_pkt_addbool(ssh, FALSE);
4952 ssh2_pkt_addstring(ssh, s->password);
4953 ssh2_pkt_defer(ssh);
65a22376 4954 /*
1408a877 4955 * We'll include a string that's an exact multiple of the
4956 * cipher block size. If the cipher is NULL for some
4957 * reason, we don't do this trick at all because we gain
4958 * nothing by it.
65a22376 4959 */
51470298 4960 if (ssh->cscipher) {
32874aea 4961 int stringlen, i;
4962
51470298 4963 stringlen = (256 - ssh->deferred_len);
4964 stringlen += ssh->cscipher->blksize - 1;
4965 stringlen -= (stringlen % ssh->cscipher->blksize);
4966 if (ssh->cscomp) {
32874aea 4967 /*
4968 * Temporarily disable actual compression,
4969 * so we can guarantee to get this string
4970 * exactly the length we want it. The
4971 * compression-disabling routine should
4972 * return an integer indicating how many
4973 * bytes we should adjust our string length
4974 * by.
4975 */
5366aed8 4976 stringlen -=
4977 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 4978 }
51470298 4979 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4980 ssh2_pkt_addstring_start(ssh);
6e9e9520 4981 for (i = 0; i < stringlen; i++) {
32874aea 4982 char c = (char) random_byte();
51470298 4983 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 4984 }
51470298 4985 ssh2_pkt_defer(ssh);
65a22376 4986 }
51470298 4987 ssh_pkt_defersend(ssh);
0d43337a 4988 logevent("Sent password");
51470298 4989 s->type = AUTH_TYPE_PASSWORD;
4990 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4991 if (s->curr_prompt == 0) {
4992 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4993 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 4994 }
51470298 4995 if (s->need_pw) { /* only add pw if we just got one! */
4996 ssh2_pkt_addstring(ssh, s->password);
4997 memset(s->password, 0, sizeof(s->password));
4998 s->curr_prompt++;
45068b27 4999 }
51470298 5000 if (s->curr_prompt >= s->num_prompts) {
5001 ssh2_pkt_send(ssh);
45068b27 5002 } else {
5003 /*
5004 * If there are prompts remaining, we set
5005 * `gotit' so that we won't attempt to get
5006 * another packet. Then we go back round the
5007 * loop and will end up retrieving another
5008 * prompt out of the existing packet. Funky or
5009 * what?
5010 */
51470298 5011 s->gotit = TRUE;
45068b27 5012 }
51470298 5013 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5014 } else {
51470298 5015 c_write_str(ssh, "No supported authentication methods"
5016 " left to try!\r\n");
5017 logevent("No supported authentications offered."
5018 " Disconnecting");
5019 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5020 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5021 ssh2_pkt_addstring(ssh, "No supported authentication"
5022 " methods available");
5023 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5024 ssh2_pkt_send(ssh);
5025 ssh->state = SSH_STATE_CLOSED;
1408a877 5026 crReturnV;
65a22376 5027 }
65a22376 5028 }
51470298 5029 } while (!s->we_are_in);
7cca0d81 5030
5031 /*
5032 * Now we're authenticated for the connection protocol. The
5033 * connection protocol will automatically have started at this
5034 * point; there's no need to send SERVICE_REQUEST.
5035 */
5036
5037 /*
5038 * So now create a channel with a session in it.
5039 */
51470298 5040 ssh->channels = newtree234(ssh_channelcmp);
5041 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5042 ssh->mainchan->ssh = ssh;
5043 ssh->mainchan->localid = alloc_channel_id(ssh);
5044 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5045 ssh2_pkt_addstring(ssh, "session");
5046 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5047 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5048 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5049 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5050 ssh2_pkt_send(ssh);
7cca0d81 5051 crWaitUntilV(ispkt);
51470298 5052 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
a8327734 5053 bombout((ssh,"Server refused to open a session"));
32874aea 5054 crReturnV;
5055 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5056 }
51470298 5057 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
a8327734 5058 bombout((ssh,"Server's channel confirmation cited wrong channel"));
32874aea 5059 crReturnV;
7cca0d81 5060 }
51470298 5061 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5062 ssh->mainchan->type = CHAN_MAINSESSION;
5063 ssh->mainchan->closes = 0;
5064 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5065 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5066 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5067 add234(ssh->channels, ssh->mainchan);
7cca0d81 5068 logevent("Opened channel for session");
5069
5070 /*
783415f8 5071 * Potentially enable X11 forwarding.
5072 */
5073 if (cfg.x11_forward) {
32874aea 5074 char proto[20], data[64];
5075 logevent("Requesting X11 forwarding");
302121de 5076 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5077 data, sizeof(data));
51470298 5078 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5079 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5080 ssh2_pkt_addstring(ssh, "x11-req");
5081 ssh2_pkt_addbool(ssh, 1); /* want reply */
5082 ssh2_pkt_addbool(ssh, 0); /* many connections */
5083 ssh2_pkt_addstring(ssh, proto);
5084 ssh2_pkt_addstring(ssh, data);
5085 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5086 ssh2_pkt_send(ssh);
32874aea 5087
5088 do {
5089 crWaitUntilV(ispkt);
51470298 5090 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5091 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5092 struct ssh_channel *c;
51470298 5093 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5094 if (!c)
5095 continue; /* nonexistent channel */
51470298 5096 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5097 }
51470298 5098 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5099
51470298 5100 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5101 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5102 bombout((ssh,"Unexpected response to X11 forwarding request:"
51470298 5103 " packet type %d", ssh->pktin.type));
32874aea 5104 crReturnV;
5105 }
5106 logevent("X11 forwarding refused");
5107 } else {
5108 logevent("X11 forwarding enabled");
51470298 5109 ssh->X11_fwd_enabled = TRUE;
32874aea 5110 }
783415f8 5111 }
5112
5113 /*
bc240b21 5114 * Enable port forwardings.
5115 */
5116 {
bc240b21 5117 char type;
5118 int n;
a4fc0d74 5119 int sport,dport,sserv,dserv;
bc240b21 5120 char sports[256], dports[256], host[256];
5121 char buf[1024];
a4fc0d74 5122 struct servent *se;
bc240b21 5123
51470298 5124 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5125 /* Add port forwardings. */
51470298 5126 ssh->portfwd_strptr = cfg.portfwd;
5127 while (*ssh->portfwd_strptr) {
5128 type = *ssh->portfwd_strptr++;
bc240b21 5129 n = 0;
51470298 5130 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5131 sports[n++] = *ssh->portfwd_strptr++;
bc240b21 5132 sports[n] = 0;
51470298 5133 if (*ssh->portfwd_strptr == '\t')
5134 ssh->portfwd_strptr++;
bc240b21 5135 n = 0;
51470298 5136 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5137 host[n++] = *ssh->portfwd_strptr++;
bc240b21 5138 host[n] = 0;
51470298 5139 if (*ssh->portfwd_strptr == ':')
5140 ssh->portfwd_strptr++;
bc240b21 5141 n = 0;
51470298 5142 while (*ssh->portfwd_strptr)
5143 dports[n++] = *ssh->portfwd_strptr++;
bc240b21 5144 dports[n] = 0;
51470298 5145 ssh->portfwd_strptr++;
bc240b21 5146 dport = atoi(dports);
a4fc0d74 5147 dserv = 0;
5148 if (dport == 0) {
5149 dserv = 1;
5150 se = getservbyname(dports, NULL);
5151 if (se != NULL) {
5152 dport = ntohs(se->s_port);
5153 } else {
5154 sprintf(buf,
5155 "Service lookup failed for destination port \"%s\"",
5156 dports);
5157 logevent(buf);
5158 }
5159 }
bc240b21 5160 sport = atoi(sports);
a4fc0d74 5161 sserv = 0;
5162 if (sport == 0) {
5163 sserv = 1;
5164 se = getservbyname(sports, NULL);
5165 if (se != NULL) {
5166 sport = ntohs(se->s_port);
5167 } else {
5168 sprintf(buf,
5169 "Service lookup failed for source port \"%s\"",
5170 sports);
5171 logevent(buf);
5172 }
5173 }
bc240b21 5174 if (sport && dport) {
5175 if (type == 'L') {
6b78788a 5176 pfd_addforward(host, dport, sport, ssh);
a4fc0d74 5177 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5178 " %s:%.*s%.*s%d%.*s",
5179 sserv ? strlen(sports) : 0, sports,
5180 sserv, "(", sport, sserv, ")",
5181 host,
5182 dserv ? strlen(dports) : 0, dports,
5183 dserv, "(", dport, dserv, ")");
bc240b21 5184 logevent(buf);
5185 } else {
5186 struct ssh_rportfwd *pf;
5187 pf = smalloc(sizeof(*pf));
5188 strcpy(pf->dhost, host);
5189 pf->dport = dport;
5190 pf->sport = sport;
51470298 5191 if (add234(ssh->rportfwds, pf) != pf) {
bc240b21 5192 sprintf(buf,
95bc8819 5193 "Duplicate remote port forwarding to %s:%d",
bc240b21 5194 host, dport);
5195 logevent(buf);
5196 sfree(pf);
5197 } else {
a4fc0d74 5198 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5199 " forward to %s:%.*s%.*s%d%.*s",
5200 sserv ? strlen(sports) : 0, sports,
5201 sserv, "(", sport, sserv, ")",
5202 host,
5203 dserv ? strlen(dports) : 0, dports,
5204 dserv, "(", dport, dserv, ")");
bc240b21 5205 logevent(buf);
51470298 5206 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5207 ssh2_pkt_addstring(ssh, "tcpip-forward");
5208 ssh2_pkt_addbool(ssh, 1);/* want reply */
beefa433 5209 if (cfg.rport_acceptall)
51470298 5210 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5211 else
51470298 5212 ssh2_pkt_addstring(ssh, "127.0.0.1");
5213 ssh2_pkt_adduint32(ssh, sport);
5214 ssh2_pkt_send(ssh);
bc240b21 5215
5216 do {
5217 crWaitUntilV(ispkt);
51470298 5218 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5219 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5220 struct ssh_channel *c;
51470298 5221 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5222 if (!c)
5223 continue;/* nonexistent channel */
51470298 5224 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5225 }
51470298 5226 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5227
51470298 5228 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5229 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
a8327734 5230 bombout((ssh,"Unexpected response to port "
c9886e66 5231 "forwarding request: packet type %d",
51470298 5232 ssh->pktin.type));
bc240b21 5233 crReturnV;
5234 }
5235 logevent("Server refused this port forwarding");
5236 } else {
5237 logevent("Remote port forwarding enabled");
5238 }
5239 }
5240 }
5241 }
5242 }
5243 }
5244
5245 /*
36c2a3e9 5246 * Potentially enable agent forwarding.
5247 */
5248 if (cfg.agentfwd && agent_exists()) {
32874aea 5249 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5250 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5251 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5252 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5253 ssh2_pkt_addbool(ssh, 1); /* want reply */
5254 ssh2_pkt_send(ssh);
32874aea 5255
5256 do {
5257 crWaitUntilV(ispkt);
51470298 5258 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5259 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5260 struct ssh_channel *c;
51470298 5261 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5262 if (!c)
5263 continue; /* nonexistent channel */
51470298 5264 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5265 }
51470298 5266 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5267
51470298 5268 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5269 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5270 bombout((ssh,"Unexpected response to agent forwarding request:"
51470298 5271 " packet type %d", ssh->pktin.type));
32874aea 5272 crReturnV;
5273 }
5274 logevent("Agent forwarding refused");
5275 } else {
5276 logevent("Agent forwarding enabled");
51470298 5277 ssh->agentfwd_enabled = TRUE;
32874aea 5278 }
36c2a3e9 5279 }
5280
5281 /*
7cca0d81 5282 * Now allocate a pty for the session.
5283 */
67779be7 5284 if (!cfg.nopty) {
51470298 5285 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5286 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5287 ssh2_pkt_addstring(ssh, "pty-req");
5288 ssh2_pkt_addbool(ssh, 1); /* want reply */
5289 ssh2_pkt_addstring(ssh, cfg.termtype);
5290 ssh2_pkt_adduint32(ssh, ssh->term_width);
5291 ssh2_pkt_adduint32(ssh, ssh->term_height);
5292 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5293 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5294 ssh2_pkt_addstring_start(ssh);
5295 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5296 ssh2_pkt_send(ssh);
5297 ssh->state = SSH_STATE_INTERMED;
32874aea 5298
5299 do {
5300 crWaitUntilV(ispkt);
51470298 5301 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5302 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5303 struct ssh_channel *c;
51470298 5304 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5305 if (!c)
5306 continue; /* nonexistent channel */
51470298 5307 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5308 }
51470298 5309 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5310
51470298 5311 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5312 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5313 bombout((ssh,"Unexpected response to pty request:"
51470298 5314 " packet type %d", ssh->pktin.type));
32874aea 5315 crReturnV;
5316 }
51470298 5317 c_write_str(ssh, "Server refused to allocate pty\r\n");
5318 ssh->editing = ssh->echoing = 1;
32874aea 5319 } else {
5320 logevent("Allocated pty");
5321 }
0965bee0 5322 } else {
51470298 5323 ssh->editing = ssh->echoing = 1;
7cca0d81 5324 }
5325
5326 /*
fd5e5847 5327 * Start a shell or a remote command. We may have to attempt
5328 * this twice if the config data has provided a second choice
5329 * of command.
7cca0d81 5330 */
fd5e5847 5331 while (1) {
5332 int subsys;
5333 char *cmd;
5334
51470298 5335 if (ssh->fallback_cmd) {
fd5e5847 5336 subsys = cfg.ssh_subsys2;
5337 cmd = cfg.remote_cmd_ptr2;
5338 } else {
5339 subsys = cfg.ssh_subsys;
5340 cmd = cfg.remote_cmd_ptr;
5341 }
5342
51470298 5343 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5344 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5345 if (subsys) {
51470298 5346 ssh2_pkt_addstring(ssh, "subsystem");
5347 ssh2_pkt_addbool(ssh, 1); /* want reply */
5348 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5349 } else if (*cmd) {
51470298 5350 ssh2_pkt_addstring(ssh, "exec");
5351 ssh2_pkt_addbool(ssh, 1); /* want reply */
5352 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5353 } else {
51470298 5354 ssh2_pkt_addstring(ssh, "shell");
5355 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5356 }
51470298 5357 ssh2_pkt_send(ssh);
fd5e5847 5358 do {
5359 crWaitUntilV(ispkt);
51470298 5360 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5361 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5362 struct ssh_channel *c;
51470298 5363 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5364 if (!c)
5365 continue; /* nonexistent channel */
51470298 5366 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5367 }
51470298 5368 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5369 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5370 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
a8327734 5371 bombout((ssh,"Unexpected response to shell/command request:"
51470298 5372 " packet type %d", ssh->pktin.type));
fd5e5847 5373 crReturnV;
5374 }
5375 /*
5376 * We failed to start the command. If this is the
5377 * fallback command, we really are finished; if it's
5378 * not, and if the fallback command exists, try falling
5379 * back to it before complaining.
5380 */
51470298 5381 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5382 logevent("Primary command failed; attempting fallback");
51470298 5383 ssh->fallback_cmd = TRUE;
fd5e5847 5384 continue;
5385 }
a8327734 5386 bombout((ssh,"Server refused to start a shell/command"));
32874aea 5387 crReturnV;
fd5e5847 5388 } else {
5389 logevent("Started a shell/command");
32874aea 5390 }
fd5e5847 5391 break;
7cca0d81 5392 }
5393
51470298 5394 ssh->state = SSH_STATE_SESSION;
5395 if (ssh->size_needed)
5396 ssh_size(ssh, ssh->term_width, ssh->term_height);
5397 if (ssh->eof_needed)
5398 ssh_special(ssh, TS_EOF);
6e48c3fe 5399
7cca0d81 5400 /*
5401 * Transfer data!
5402 */
b9d7bcad 5403 if (ssh->ldisc)
5404 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5405 ssh->send_ok = 1;
7cca0d81 5406 while (1) {
e5574168 5407 crReturnV;
51470298 5408 s->try_send = FALSE;
7cca0d81 5409 if (ispkt) {
51470298 5410 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5411 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5412 char *data;
5413 int length;
51470298 5414 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5415 struct ssh_channel *c;
51470298 5416 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5417 if (!c)
5418 continue; /* nonexistent channel */
51470298 5419 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5420 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5421 continue; /* extended but not stderr */
51470298 5422 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5423 if (data) {
5471d09a 5424 int bufsize;
5425 c->v.v2.locwindow -= length;
32874aea 5426 switch (c->type) {
5427 case CHAN_MAINSESSION:
5471d09a 5428 bufsize =
51470298 5429 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5430 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5431 data, length);
32874aea 5432 break;
5433 case CHAN_X11:
5471d09a 5434 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5435 break;
d74d141c 5436 case CHAN_SOCKDATA:
5471d09a 5437 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5438 break;
36c2a3e9 5439 case CHAN_AGENT:
32874aea 5440 while (length > 0) {
5441 if (c->u.a.lensofar < 4) {
5442 int l = min(4 - c->u.a.lensofar, length);
5443 memcpy(c->u.a.msglen + c->u.a.lensofar,
5444 data, l);
5445 data += l;
5446 length -= l;
5447 c->u.a.lensofar += l;
5448 }
5449 if (c->u.a.lensofar == 4) {
5450 c->u.a.totallen =
5451 4 + GET_32BIT(c->u.a.msglen);
5452 c->u.a.message = smalloc(c->u.a.totallen);
5453 memcpy(c->u.a.message, c->u.a.msglen, 4);
5454 }
5455 if (c->u.a.lensofar >= 4 && length > 0) {
5456 int l =
5457 min(c->u.a.totallen - c->u.a.lensofar,
5458 length);
5459 memcpy(c->u.a.message + c->u.a.lensofar,
5460 data, l);
5461 data += l;
5462 length -= l;
5463 c->u.a.lensofar += l;
5464 }
5465 if (c->u.a.lensofar == c->u.a.totallen) {
5466 void *reply, *sentreply;
5467 int replylen;
5468 agent_query(c->u.a.message,
5469 c->u.a.totallen, &reply,
5470 &replylen);
5471 if (reply)
5472 sentreply = reply;
5473 else {
5474 /* Fake SSH_AGENT_FAILURE. */
5475 sentreply = "\0\0\0\1\5";
5476 replylen = 5;
5477 }
51470298 5478 ssh2_add_channel_data(c, sentreply, replylen);
5479 s->try_send = TRUE;
32874aea 5480 if (reply)
5481 sfree(reply);
5482 sfree(c->u.a.message);
5483 c->u.a.lensofar = 0;
5484 }
5485 }
5471d09a 5486 bufsize = 0;
32874aea 5487 break;
5488 }
5489 /*
5471d09a 5490 * If we are not buffering too much data,
5491 * enlarge the window again at the remote side.
32874aea 5492 */
5471d09a 5493 if (bufsize < OUR_V2_WINSIZE)
5494 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5495 }
51470298 5496 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5497 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5498 struct ssh_channel *c;
5499
51470298 5500 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5501 if (!c)
5502 continue; /* nonexistent channel */
5503
5504 if (c->type == CHAN_X11) {
5505 /*
5506 * Remote EOF on an X11 channel means we should
5507 * wrap up and close the channel ourselves.
5508 */
5509 x11_close(c->u.x11.s);
5510 sshfwd_close(c);
5511 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5512 sshfwd_close(c);
d74d141c 5513 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5514 pfd_close(c->u.pfd.s);
5515 sshfwd_close(c);
36c2a3e9 5516 }
51470298 5517 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5518 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5519 struct ssh_channel *c;
5520
51470298 5521 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5522 if (!c || ((int)c->remoteid) == -1) {
a8327734 5523 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 5524 c ? "half-open" : "nonexistent", i));
5525 }
32874aea 5526 /* Do pre-close processing on the channel. */
5527 switch (c->type) {
5528 case CHAN_MAINSESSION:
5529 break; /* nothing to see here, move along */
5530 case CHAN_X11:
92f157bd 5531 if (c->u.x11.s != NULL)
5532 x11_close(c->u.x11.s);
5533 sshfwd_close(c);
32874aea 5534 break;
5535 case CHAN_AGENT:
92f157bd 5536 sshfwd_close(c);
32874aea 5537 break;
d74d141c 5538 case CHAN_SOCKDATA:
92f157bd 5539 if (c->u.pfd.s != NULL)
5540 pfd_close(c->u.pfd.s);
5541 sshfwd_close(c);
bc240b21 5542 break;
32874aea 5543 }
92f157bd 5544 if (c->closes == 0) {
51470298 5545 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5546 ssh2_pkt_adduint32(ssh, c->remoteid);
5547 ssh2_pkt_send(ssh);
92f157bd 5548 }
51470298 5549 del234(ssh->channels, c);
5471d09a 5550 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5551 sfree(c);
5552
5553 /*
5554 * See if that was the last channel left open.
5555 */
51470298 5556 if (count234(ssh->channels) == 0) {
ca2914d1 5557#if 0
5558 /*
5559 * We used to send SSH_MSG_DISCONNECT here,
5560 * because I'd believed that _every_ conforming
5561 * SSH2 connection had to end with a disconnect
5562 * being sent by at least one side; apparently
5563 * I was wrong and it's perfectly OK to
5564 * unceremoniously slam the connection shut
5565 * when you're done, and indeed OpenSSH feels
5566 * this is more polite than sending a
5567 * DISCONNECT. So now we don't.
5568 */
32874aea 5569 logevent("All channels closed. Disconnecting");
51470298 5570 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5571 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5572 ssh2_pkt_addstring(ssh, "All open channels closed");
5573 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5574 ssh2_pkt_send(ssh);
ca2914d1 5575#endif
51470298 5576 ssh->state = SSH_STATE_CLOSED;
32874aea 5577 crReturnV;
5578 }
5579 continue; /* remote sends close; ignore (FIXME) */
51470298 5580 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5581 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5582 struct ssh_channel *c;
51470298 5583 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5584 if (!c)
5585 continue; /* nonexistent channel */
51470298 5586 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5587 s->try_send = TRUE;
5588 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5589 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5590 struct ssh_channel *c;
51470298 5591 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5592 if (!c)
5593 continue; /* nonexistent channel */
5594 if (c->type != CHAN_SOCKDATA_DORMANT)
5595 continue; /* dunno why they're confirming this */
51470298 5596 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5597 c->type = CHAN_SOCKDATA;
51470298 5598 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5599 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5600 if (c->u.pfd.s)
5601 pfd_confirm(c->u.pfd.s);
5602 if (c->closes) {
5603 /*
5604 * We have a pending close on this channel,
5605 * which we decided on before the server acked
5606 * the channel open. So now we know the
5607 * remoteid, we can close it again.
5608 */
51470298 5609 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5610 ssh2_pkt_adduint32(ssh, c->remoteid);
5611 ssh2_pkt_send(ssh);
4ed34d25 5612 }
51470298 5613 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5614 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5615 struct ssh_channel *c;
51470298 5616 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5617 if (!c)
5618 continue; /* nonexistent channel */
5619 if (c->type != CHAN_SOCKDATA_DORMANT)
5620 continue; /* dunno why they're failing this */
5621
5622 logevent("Forwarded connection refused by server");
5623
5624 pfd_close(c->u.pfd.s);
5625
51470298 5626 del234(ssh->channels, c);
724cface 5627 sfree(c);
51470298 5628 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5629 unsigned localid;
5630 char *type;
5631 int typelen, want_reply;
5632 struct ssh_channel *c;
5633
51470298 5634 localid = ssh2_pkt_getuint32(ssh);
5635 ssh2_pkt_getstring(ssh, &type, &typelen);
5636 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5637
5638 /*
5639 * First, check that the channel exists. Otherwise,
5640 * we can instantly disconnect with a rude message.
5641 */
51470298 5642 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5643 if (!c) {
5644 char buf[80];
5645 sprintf(buf, "Received channel request for nonexistent"
5646 " channel %d", localid);
5647 logevent(buf);
51470298 5648 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5649 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5650 ssh2_pkt_addstring(ssh, buf);
5651 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5652 ssh2_pkt_send(ssh);
247308b5 5653 connection_fatal("%s", buf);
51470298 5654 ssh->state = SSH_STATE_CLOSED;
ebb0a590 5655 crReturnV;
5656 }
5657
5658 /*
d8d6c7e5 5659 * Having got the channel number, we now look at
5660 * the request type string to see if it's something
5661 * we recognise.
ebb0a590 5662 */
d8d6c7e5 5663 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5664 c == ssh->mainchan) {
d8d6c7e5 5665 /* We recognise "exit-status" on the primary channel. */
5666 char buf[100];
51470298 5667 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5668 sprintf(buf, "Server sent command exit status %d",
51470298 5669 ssh->exitcode);
d8d6c7e5 5670 logevent(buf);
5671 if (want_reply) {
51470298 5672 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5673 ssh2_pkt_adduint32(ssh, c->remoteid);
5674 ssh2_pkt_send(ssh);
d8d6c7e5 5675 }
5676 } else {
5677 /*
5678 * This is a channel request we don't know
5679 * about, so we now either ignore the request
5680 * or respond with CHANNEL_FAILURE, depending
5681 * on want_reply.
5682 */
5683 if (want_reply) {
51470298 5684 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5685 ssh2_pkt_adduint32(ssh, c->remoteid);
5686 ssh2_pkt_send(ssh);
d8d6c7e5 5687 }
ebb0a590 5688 }
51470298 5689 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5690 char *type;
5691 int typelen, want_reply;
5692
51470298 5693 ssh2_pkt_getstring(ssh, &type, &typelen);
5694 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5695
5696 /*
5697 * We currently don't support any global requests
5698 * at all, so we either ignore the request or
5699 * respond with REQUEST_FAILURE, depending on
5700 * want_reply.
5701 */
5702 if (want_reply) {
51470298 5703 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5704 ssh2_pkt_send(ssh);
697d4856 5705 }
51470298 5706 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5707 char *type;
5708 int typelen;
5709 char *error = NULL;
5710 struct ssh_channel *c;
bc240b21 5711 unsigned remid, winsize, pktsize;
51470298 5712 ssh2_pkt_getstring(ssh, &type, &typelen);
32874aea 5713 c = smalloc(sizeof(struct ssh_channel));
51470298 5714 c->ssh = ssh;
32874aea 5715
51470298 5716 remid = ssh2_pkt_getuint32(ssh);
5717 winsize = ssh2_pkt_getuint32(ssh);
5718 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 5719
32874aea 5720 if (typelen == 3 && !memcmp(type, "x11", 3)) {
51470298 5721 if (!ssh->X11_fwd_enabled)
32874aea 5722 error = "X11 forwarding is not enabled";
302121de 5723 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5724 ssh->x11auth) != NULL) {
32874aea 5725 error = "Unable to open an X11 connection";
5726 } else {
5727 c->type = CHAN_X11;
5728 }
bc240b21 5729 } else if (typelen == 15 &&
5730 !memcmp(type, "forwarded-tcpip", 15)) {
5731 struct ssh_rportfwd pf, *realpf;
5732 char *dummy;
5733 int dummylen;
51470298 5734 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5735 pf.sport = ssh2_pkt_getuint32(ssh);
5736 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 5737 if (realpf == NULL) {
5738 error = "Remote port is not recognised";
5739 } else {
5740 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5741 realpf->dport, c);
5742 char buf[1024];
5743 sprintf(buf, "Received remote port open request for %s:%d",
5744 realpf->dhost, realpf->dport);
5745 logevent(buf);
5746 if (e != NULL) {
5747 sprintf(buf, "Port open failed: %s", e);
5748 logevent(buf);
5749 error = "Port open failed";
5750 } else {
5751 logevent("Forwarded port opened successfully");
5752 c->type = CHAN_SOCKDATA;
5753 }
5754 }
32874aea 5755 } else if (typelen == 22 &&
36c2a3e9 5756 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 5757 if (!ssh->agentfwd_enabled)
32874aea 5758 error = "Agent forwarding is not enabled";
36c2a3e9 5759 else {
32874aea 5760 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5761 c->u.a.lensofar = 0;
32874aea 5762 }
5763 } else {
5764 error = "Unsupported channel type requested";
5765 }
5766
bc240b21 5767 c->remoteid = remid;
32874aea 5768 if (error) {
51470298 5769 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5770 ssh2_pkt_adduint32(ssh, c->remoteid);
5771 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5772 ssh2_pkt_addstring(ssh, error);
5773 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5774 ssh2_pkt_send(ssh);
32874aea 5775 sfree(c);
5776 } else {
51470298 5777 c->localid = alloc_channel_id(ssh);
32874aea 5778 c->closes = 0;
5471d09a 5779 c->v.v2.locwindow = OUR_V2_WINSIZE;
5780 c->v.v2.remwindow = winsize;
5781 c->v.v2.remmaxpkt = pktsize;
5782 bufchain_init(&c->v.v2.outbuffer);
51470298 5783 add234(ssh->channels, c);
5784 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5785 ssh2_pkt_adduint32(ssh, c->remoteid);
5786 ssh2_pkt_adduint32(ssh, c->localid);
5787 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5788 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5789 ssh2_pkt_send(ssh);
32874aea 5790 }
7cca0d81 5791 } else {
a8327734 5792 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
32874aea 5793 crReturnV;
7cca0d81 5794 }
5795 } else {
32874aea 5796 /*
5797 * We have spare data. Add it to the channel buffer.
5798 */
51470298 5799 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5800 s->try_send = TRUE;
32874aea 5801 }
51470298 5802 if (s->try_send) {
32874aea 5803 int i;
5804 struct ssh_channel *c;
5805 /*
5806 * Try to send data on all channels if we can.
5807 */
51470298 5808 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 5809 int bufsize = ssh2_try_send(c);
5810 if (bufsize == 0) {
5811 switch (c->type) {
5812 case CHAN_MAINSESSION:
5813 /* stdin need not receive an unthrottle
5814 * notification since it will be polled */
5815 break;
5816 case CHAN_X11:
5817 x11_unthrottle(c->u.x11.s);
5818 break;
5819 case CHAN_AGENT:
5820 /* agent sockets are request/response and need no
5821 * buffer management */
5822 break;
5823 case CHAN_SOCKDATA:
5824 pfd_unthrottle(c->u.pfd.s);
5825 break;
5826 }
5827 }
5828 }
7cca0d81 5829 }
e5574168 5830 }
5831
5832 crFinishV;
5833}
5834
5835/*
7cca0d81 5836 * Handle the top-level SSH2 protocol.
5837 */
51470298 5838static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 5839{
51470298 5840 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 5841 return;
51470298 5842 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 5843}
5844
5845/*
8df7a775 5846 * Called to set up the connection.
374330e2 5847 *
5848 * Returns an error message, or NULL on success.
374330e2 5849 */
51470298 5850static char *ssh_init(void *frontend_handle, void **backend_handle,
887035a5 5851 char *host, int port, char **realhost, int nodelay)
32874aea 5852{
fb09bf1c 5853 char *p;
51470298 5854 Ssh ssh;
5855
5856 ssh = smalloc(sizeof(*ssh));
5857 ssh->s = NULL;
5858 ssh->cipher = NULL;
371e569c 5859 ssh->v1_cipher_ctx = NULL;
0183b242 5860 ssh->crcda_ctx = NULL;
51470298 5861 ssh->cscipher = NULL;
371e569c 5862 ssh->cs_cipher_ctx = NULL;
51470298 5863 ssh->sccipher = NULL;
371e569c 5864 ssh->sc_cipher_ctx = NULL;
51470298 5865 ssh->csmac = NULL;
a8327734 5866 ssh->cs_mac_ctx = NULL;
51470298 5867 ssh->scmac = NULL;
e0e1a00d 5868 ssh->sc_mac_ctx = NULL;
51470298 5869 ssh->cscomp = NULL;
5366aed8 5870 ssh->cs_comp_ctx = NULL;
51470298 5871 ssh->sccomp = NULL;
5366aed8 5872 ssh->sc_comp_ctx = NULL;
51470298 5873 ssh->kex = NULL;
5874 ssh->hostkey = NULL;
5875 ssh->exitcode = -1;
5876 ssh->state = SSH_STATE_PREPACKET;
5877 ssh->size_needed = FALSE;
5878 ssh->eof_needed = FALSE;
b9d7bcad 5879 ssh->ldisc = NULL;
a8327734 5880 ssh->logctx = NULL;
51470298 5881 {
5882 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5883 ssh->pktin = ssh->pktout = empty;
5884 }
5885 ssh->deferred_send_data = NULL;
5886 ssh->deferred_len = 0;
5887 ssh->deferred_size = 0;
5888 ssh->fallback_cmd = 0;
5889 ssh->pkt_ctx = 0;
302121de 5890 ssh->x11auth = NULL;
be738459 5891 ssh->v1_compressing = FALSE;
51470298 5892 ssh->v2_outgoing_sequence = 0;
5893 ssh->ssh1_rdpkt_crstate = 0;
5894 ssh->ssh2_rdpkt_crstate = 0;
5895 ssh->do_ssh_init_crstate = 0;
5896 ssh->ssh_gotdata_crstate = 0;
5897 ssh->ssh1_protocol_crstate = 0;
5898 ssh->do_ssh1_login_crstate = 0;
5899 ssh->do_ssh2_transport_crstate = 0;
5900 ssh->do_ssh2_authconn_crstate = 0;
5901 ssh->do_ssh_init_state = NULL;
5902 ssh->do_ssh1_login_state = NULL;
5903 ssh->do_ssh2_transport_state = NULL;
5904 ssh->do_ssh2_authconn_state = NULL;
5905
5906 *backend_handle = ssh;
32874aea 5907
8f203108 5908#ifdef MSCRYPTOAPI
32874aea 5909 if (crypto_startup() == 0)
8f203108 5910 return "Microsoft high encryption pack not installed!";
5911#endif
374330e2 5912
51470298 5913 ssh->frontend = frontend_handle;
5914 ssh->term_width = cfg.width;
5915 ssh->term_height = cfg.height;
887035a5 5916
51470298 5917 ssh->send_ok = 0;
5918 ssh->editing = 0;
5919 ssh->echoing = 0;
5920 ssh->v1_throttle_count = 0;
5921 ssh->overall_bufsize = 0;
5922 ssh->fallback_cmd = 0;
8df7a775 5923
51470298 5924 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 5925 if (p != NULL)
5926 return p;
374330e2 5927
374330e2 5928 return NULL;
5929}
5930
5931/*
374330e2 5932 * Called to send data down the Telnet connection.
5933 */
51470298 5934static int ssh_send(void *handle, char *buf, int len)
32874aea 5935{
51470298 5936 Ssh ssh = (Ssh) handle;
5937
5938 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5939 return 0;
374330e2 5940
51470298 5941 ssh->protocol(ssh, buf, len, 0);
5471d09a 5942
51470298 5943 return ssh_sendbuffer(ssh);
5471d09a 5944}
5945
5946/*
5947 * Called to query the current amount of buffered stdin data.
5948 */
51470298 5949static int ssh_sendbuffer(void *handle)
5471d09a 5950{
51470298 5951 Ssh ssh = (Ssh) handle;
5471d09a 5952 int override_value;
5953
51470298 5954 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5955 return 0;
5956
5957 /*
5958 * If the SSH socket itself has backed up, add the total backup
5959 * size on that to any individual buffer on the stdin channel.
5960 */
5961 override_value = 0;
51470298 5962 if (ssh->throttled_all)
5963 override_value = ssh->overall_bufsize;
5471d09a 5964
51470298 5965 if (ssh->version == 1) {
5471d09a 5966 return override_value;
51470298 5967 } else if (ssh->version == 2) {
5968 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 5969 return override_value;
5970 else
51470298 5971 return (override_value +
5972 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 5973 }
5974
5975 return 0;
374330e2 5976}
5977
5978/*
6e48c3fe 5979 * Called to set the size of the window from SSH's POV.
374330e2 5980 */
51470298 5981static void ssh_size(void *handle, int width, int height)
32874aea 5982{
51470298 5983 Ssh ssh = (Ssh) handle;
5984
5985 ssh->term_width = width;
5986 ssh->term_height = height;
f278d6f8 5987
51470298 5988 switch (ssh->state) {
374330e2 5989 case SSH_STATE_BEFORE_SIZE:
3687d221 5990 case SSH_STATE_PREPACKET:
21248260 5991 case SSH_STATE_CLOSED:
374330e2 5992 break; /* do nothing */
5993 case SSH_STATE_INTERMED:
51470298 5994 ssh->size_needed = TRUE; /* buffer for later */
374330e2 5995 break;
5996 case SSH_STATE_SESSION:
32874aea 5997 if (!cfg.nopty) {
51470298 5998 if (ssh->version == 1) {
5999 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6000 PKT_INT, ssh->term_height,
6001 PKT_INT, ssh->term_width,
32874aea 6002 PKT_INT, 0, PKT_INT, 0, PKT_END);
6003 } else {
51470298 6004 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6005 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6006 ssh2_pkt_addstring(ssh, "window-change");
6007 ssh2_pkt_addbool(ssh, 0);
6008 ssh2_pkt_adduint32(ssh, ssh->term_width);
6009 ssh2_pkt_adduint32(ssh, ssh->term_height);
6010 ssh2_pkt_adduint32(ssh, 0);
6011 ssh2_pkt_adduint32(ssh, 0);
6012 ssh2_pkt_send(ssh);
32874aea 6013 }
6014 }
6015 break;
374330e2 6016 }
6017}
6018
6019/*
6abbf9e3 6020 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6021 * can send an EOF and collect resulting output (e.g. `plink
6022 * hostname sort').
374330e2 6023 */
51470298 6024static void ssh_special(void *handle, Telnet_Special code)
32874aea 6025{
51470298 6026 Ssh ssh = (Ssh) handle;
6027
6abbf9e3 6028 if (code == TS_EOF) {
51470298 6029 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6030 /*
6031 * Buffer the EOF in case we are pre-SESSION, so we can
6032 * send it as soon as we reach SESSION.
6033 */
6034 if (code == TS_EOF)
51470298 6035 ssh->eof_needed = TRUE;
32874aea 6036 return;
6037 }
51470298 6038 if (ssh->version == 1) {
6039 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6040 } else {
51470298 6041 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6042 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6043 ssh2_pkt_send(ssh);
32874aea 6044 }
6045 logevent("Sent EOF message");
ec55b220 6046 } else if (code == TS_PING) {
51470298 6047 if (ssh->state == SSH_STATE_CLOSED
6048 || ssh->state == SSH_STATE_PREPACKET) return;
6049 if (ssh->version == 1) {
6050 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6051 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6052 } else {
51470298 6053 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6054 ssh2_pkt_addstring_start(ssh);
6055 ssh2_pkt_send(ssh);
32874aea 6056 }
6abbf9e3 6057 } else {
32874aea 6058 /* do nothing */
6abbf9e3 6059 }
374330e2 6060}
6061
51470298 6062void *new_sock_channel(void *handle, Socket s)
d74d141c 6063{
51470298 6064 Ssh ssh = (Ssh) handle;
d74d141c 6065 struct ssh_channel *c;
6066 c = smalloc(sizeof(struct ssh_channel));
51470298 6067 c->ssh = ssh;
d74d141c 6068
6069 if (c) {
bc240b21 6070 c->remoteid = -1; /* to be set when open confirmed */
51470298 6071 c->localid = alloc_channel_id(ssh);
d74d141c 6072 c->closes = 0;
bc240b21 6073 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6074 c->u.pfd.s = s;
013dd8c0 6075 bufchain_init(&c->v.v2.outbuffer);
51470298 6076 add234(ssh->channels, c);
d74d141c 6077 }
6078 return c;
6079}
6080
5471d09a 6081/*
6082 * This is called when stdout/stderr (the entity to which
6083 * from_backend sends data) manages to clear some backlog.
6084 */
51470298 6085void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6086{
51470298 6087 Ssh ssh = (Ssh) handle;
6088 if (ssh->version == 1) {
6089 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6090 ssh->v1_stdout_throttling = 0;
6091 ssh1_throttle(ssh, -1);
5471d09a 6092 }
6093 } else {
51470298 6094 if (ssh->mainchan && ssh->mainchan->closes == 0)
6095 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6096 }
6097}
6098
6b78788a 6099void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6100{
6101 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6102 Ssh ssh = c->ssh;
d74d141c 6103 char buf[1024];
6104
6105 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
6106 logevent(buf);
6107
51470298 6108 if (ssh->version == 1) {
6109 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6110 PKT_INT, c->localid,
6111 PKT_STR, hostname,
6112 PKT_INT, port,
6113 //PKT_STR, <org:orgport>,
6114 PKT_END);
6115 } else {
51470298 6116 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6117 ssh2_pkt_addstring(ssh, "direct-tcpip");
6118 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6119 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6120 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6121 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6122 ssh2_pkt_addstring(ssh, hostname);
6123 ssh2_pkt_adduint32(ssh, port);
bc240b21 6124 /*
6125 * We make up values for the originator data; partly it's
6126 * too much hassle to keep track, and partly I'm not
6127 * convinced the server should be told details like that
6128 * about my local network configuration.
6129 */
51470298 6130 ssh2_pkt_addstring(ssh, "client-side-connection");
6131 ssh2_pkt_adduint32(ssh, 0);
6132 ssh2_pkt_send(ssh);
bc240b21 6133 }
d74d141c 6134}
6135
6136
51470298 6137static Socket ssh_socket(void *handle)
32874aea 6138{
51470298 6139 Ssh ssh = (Ssh) handle;
6140 return ssh->s;
32874aea 6141}
8ccc75b0 6142
51470298 6143static int ssh_sendok(void *handle)
32874aea 6144{
51470298 6145 Ssh ssh = (Ssh) handle;
6146 return ssh->send_ok;
32874aea 6147}
fb09bf1c 6148
51470298 6149static int ssh_ldisc(void *handle, int option)
32874aea 6150{
51470298 6151 Ssh ssh = (Ssh) handle;
32874aea 6152 if (option == LD_ECHO)
51470298 6153 return ssh->echoing;
32874aea 6154 if (option == LD_EDIT)
51470298 6155 return ssh->editing;
0965bee0 6156 return FALSE;
6157}
6158
b9d7bcad 6159static void ssh_provide_ldisc(void *handle, void *ldisc)
6160{
6161 Ssh ssh = (Ssh) handle;
6162 ssh->ldisc = ldisc;
6163}
6164
a8327734 6165static void ssh_provide_logctx(void *handle, void *logctx)
6166{
6167 Ssh ssh = (Ssh) handle;
6168 ssh->logctx = logctx;
6169}
6170
51470298 6171static int ssh_return_exitcode(void *handle)
6172{
6173 Ssh ssh = (Ssh) handle;
6174 return ssh->exitcode;
6175}
6176
6177/*
6178 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6179 * that fails. This variable is the means by which scp.c can reach
6180 * into the SSH code and find out which one it got.
6181 */
6182extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6183{
51470298 6184 Ssh ssh = (Ssh) handle;
6185 return ssh->fallback_cmd;
d8d6c7e5 6186}
6187
374330e2 6188Backend ssh_backend = {
6189 ssh_init,
374330e2 6190 ssh_send,
5471d09a 6191 ssh_sendbuffer,
374330e2 6192 ssh_size,
4017be6d 6193 ssh_special,
8ccc75b0 6194 ssh_socket,
d8d6c7e5 6195 ssh_return_exitcode,
97db3be4 6196 ssh_sendok,
0965bee0 6197 ssh_ldisc,
b9d7bcad 6198 ssh_provide_ldisc,
a8327734 6199 ssh_provide_logctx,
5471d09a 6200 ssh_unthrottle,
97db3be4 6201 22
bc240b21 6202};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator