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Update to reflect the last batch of proxy stuff we got from Justin Bradford.
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 21
247308b5 22/* logevent, only printf-formatted. */
23void logeventf(char *fmt, ...)
24{
25 va_list ap;
26 char stuff[200];
27
28 va_start(ap, fmt);
29 vsprintf(stuff, fmt, ap);
30 va_end(ap);
31 logevent(stuff);
32}
33
3cd52910 34#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 35 (s ? sk_close(s), s = NULL : 0), \
247308b5 36 logeventf msg, connection_fatal msg )
8d5de777 37
32874aea 38#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41#define SSH1_CMSG_USER 4 /* 0x4 */
42#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50#define SSH1_SMSG_SUCCESS 14 /* 0xe */
51#define SSH1_SMSG_FAILURE 15 /* 0xf */
52#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55#define SSH1_CMSG_EOF 19 /* 0x13 */
56#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67#define SSH1_MSG_IGNORE 32 /* 0x20 */
68#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71#define SSH1_MSG_DEBUG 36 /* 0x24 */
72#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
79
80#define SSH1_AUTH_TIS 5 /* 0x5 */
81#define SSH1_AUTH_CCARD 16 /* 0x10 */
82
83#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 84/* Mask for protoflags we will echo back to server if seen */
32874aea 85#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
86
87#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88#define SSH2_MSG_IGNORE 2 /* 0x2 */
89#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90#define SSH2_MSG_DEBUG 4 /* 0x4 */
91#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93#define SSH2_MSG_KEXINIT 20 /* 0x14 */
94#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 107#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 109#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
123
00db133f 124/*
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
127 */
128#define SSH2_PKTCTX_DHGROUP1 0x0001
129#define SSH2_PKTCTX_DHGEX 0x0002
130#define SSH2_PKTCTX_PUBLICKEY 0x0010
131#define SSH2_PKTCTX_PASSWORD 0x0020
132#define SSH2_PKTCTX_KBDINTER 0x0040
133#define SSH2_PKTCTX_AUTH_MASK 0x00F0
134
32874aea 135#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 150
151static const char *const ssh2_disconnect_reasons[] = {
152 NULL,
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
168};
9005f3ba 169
32874aea 170#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 174
32874aea 175#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 176
7d503c31 177/*
178 * Various remote-bug flags.
179 */
180#define BUG_CHOKES_ON_SSH1_IGNORE 1
181#define BUG_SSH2_HMAC 2
bd358db1 182#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 183#define BUG_CHOKES_ON_RSA 8
1dd353b5 184#define BUG_SSH2_RSA_PADDING 16
088bde77 185#define BUG_SSH2_DERIVEKEY 32
bd358db1 186
00db133f 187static int ssh_pkt_ctx = 0;
188
189#define translate(x) if (type == x) return #x
190#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
191char *ssh1_pkt_type(int type)
192{
193 translate(SSH1_MSG_DISCONNECT);
194 translate(SSH1_SMSG_PUBLIC_KEY);
195 translate(SSH1_CMSG_SESSION_KEY);
196 translate(SSH1_CMSG_USER);
197 translate(SSH1_CMSG_AUTH_RSA);
198 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
199 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
200 translate(SSH1_CMSG_AUTH_PASSWORD);
201 translate(SSH1_CMSG_REQUEST_PTY);
202 translate(SSH1_CMSG_WINDOW_SIZE);
203 translate(SSH1_CMSG_EXEC_SHELL);
204 translate(SSH1_CMSG_EXEC_CMD);
205 translate(SSH1_SMSG_SUCCESS);
206 translate(SSH1_SMSG_FAILURE);
207 translate(SSH1_CMSG_STDIN_DATA);
208 translate(SSH1_SMSG_STDOUT_DATA);
209 translate(SSH1_SMSG_STDERR_DATA);
210 translate(SSH1_CMSG_EOF);
211 translate(SSH1_SMSG_EXIT_STATUS);
212 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
213 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
214 translate(SSH1_MSG_CHANNEL_DATA);
215 translate(SSH1_MSG_CHANNEL_CLOSE);
216 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
217 translate(SSH1_SMSG_X11_OPEN);
218 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
219 translate(SSH1_MSG_PORT_OPEN);
220 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
221 translate(SSH1_SMSG_AGENT_OPEN);
222 translate(SSH1_MSG_IGNORE);
223 translate(SSH1_CMSG_EXIT_CONFIRMATION);
224 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
225 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
226 translate(SSH1_MSG_DEBUG);
227 translate(SSH1_CMSG_REQUEST_COMPRESSION);
228 translate(SSH1_CMSG_AUTH_TIS);
229 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
230 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
231 translate(SSH1_CMSG_AUTH_CCARD);
232 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
233 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
234 return "unknown";
235}
236char *ssh2_pkt_type(int type)
237{
238 translate(SSH2_MSG_DISCONNECT);
239 translate(SSH2_MSG_IGNORE);
240 translate(SSH2_MSG_UNIMPLEMENTED);
241 translate(SSH2_MSG_DEBUG);
242 translate(SSH2_MSG_SERVICE_REQUEST);
243 translate(SSH2_MSG_SERVICE_ACCEPT);
244 translate(SSH2_MSG_KEXINIT);
245 translate(SSH2_MSG_NEWKEYS);
246 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
248 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
251 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
252 translate(SSH2_MSG_USERAUTH_REQUEST);
253 translate(SSH2_MSG_USERAUTH_FAILURE);
254 translate(SSH2_MSG_USERAUTH_SUCCESS);
255 translate(SSH2_MSG_USERAUTH_BANNER);
256 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
257 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
258 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
259 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
260 translate(SSH2_MSG_GLOBAL_REQUEST);
261 translate(SSH2_MSG_REQUEST_SUCCESS);
262 translate(SSH2_MSG_REQUEST_FAILURE);
263 translate(SSH2_MSG_CHANNEL_OPEN);
264 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
265 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
266 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
267 translate(SSH2_MSG_CHANNEL_DATA);
268 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
269 translate(SSH2_MSG_CHANNEL_EOF);
270 translate(SSH2_MSG_CHANNEL_CLOSE);
271 translate(SSH2_MSG_CHANNEL_REQUEST);
272 translate(SSH2_MSG_CHANNEL_SUCCESS);
273 translate(SSH2_MSG_CHANNEL_FAILURE);
274 return "unknown";
275}
276#undef translate
277#undef translatec
7d503c31 278
fb09bf1c 279#define GET_32BIT(cp) \
280 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
281 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
282 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
283 ((unsigned long)(unsigned char)(cp)[3]))
284
285#define PUT_32BIT(cp, value) { \
286 (cp)[0] = (unsigned char)((value) >> 24); \
287 (cp)[1] = (unsigned char)((value) >> 16); \
288 (cp)[2] = (unsigned char)((value) >> 8); \
289 (cp)[3] = (unsigned char)(value); }
290
7cca0d81 291enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 292
374330e2 293/* Coroutine mechanics for the sillier bits of the code */
294#define crBegin1 static int crLine = 0;
295#define crBegin2 switch(crLine) { case 0:;
296#define crBegin crBegin1; crBegin2;
297#define crFinish(z) } crLine = 0; return (z)
298#define crFinishV } crLine = 0; return
299#define crReturn(z) \
300 do {\
301 crLine=__LINE__; return (z); case __LINE__:;\
302 } while (0)
303#define crReturnV \
304 do {\
305 crLine=__LINE__; return; case __LINE__:;\
306 } while (0)
307#define crStop(z) do{ crLine = 0; return (z); }while(0)
308#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 309#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 310#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 311
32874aea 312extern char *x11_init(Socket *, char *, void *);
313extern void x11_close(Socket);
5471d09a 314extern int x11_send(Socket, char *, int);
9c964e85 315extern void x11_invent_auth(char *, int, char *, int);
5471d09a 316extern void x11_unthrottle(Socket s);
317extern void x11_override_throttle(Socket s, int enable);
9c964e85 318
d74d141c 319extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
320extern char *pfd_addforward(char *desthost, int destport, int port);
321extern void pfd_close(Socket s);
5471d09a 322extern int pfd_send(Socket s, char *data, int len);
d74d141c 323extern void pfd_confirm(Socket s);
5471d09a 324extern void pfd_unthrottle(Socket s);
325extern void pfd_override_throttle(Socket s, int enable);
326
3d63ca2e 327static void ssh2_pkt_init(int pkt_type);
328static void ssh2_pkt_addbool(unsigned char value);
329static void ssh2_pkt_adduint32(unsigned long value);
330static void ssh2_pkt_addstring_start(void);
331static void ssh2_pkt_addstring_str(char *data);
332static void ssh2_pkt_addstring_data(char *data, int len);
333static void ssh2_pkt_addstring(char *data);
334static char *ssh2_mpint_fmt(Bignum b, int *len);
335static void ssh2_pkt_addmp(Bignum b);
336static int ssh2_pkt_construct(void);
337static void ssh2_pkt_send(void);
338
5471d09a 339/*
340 * Buffer management constants. There are several of these for
341 * various different purposes:
342 *
343 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
344 * on a local data stream before we throttle the whole SSH
345 * connection (in SSH1 only). Throttling the whole connection is
346 * pretty drastic so we set this high in the hope it won't
347 * happen very often.
348 *
349 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
350 * on the SSH connection itself before we defensively throttle
351 * _all_ local data streams. This is pretty drastic too (though
352 * thankfully unlikely in SSH2 since the window mechanism should
353 * ensure that the server never has any need to throttle its end
354 * of the connection), so we set this high as well.
355 *
356 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
357 * channels.
358 */
359
360#define SSH1_BUFFER_LIMIT 32768
361#define SSH_MAX_BACKLOG 32768
362#define OUR_V2_WINSIZE 16384
d74d141c 363
a92dd380 364const static struct ssh_kex *kex_algs[] = {
a92dd380 365 &ssh_diffiehellman_gex,
32874aea 366 &ssh_diffiehellman
367};
e5574168 368
85cc02bb 369const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 370
32874aea 371static void nullmac_key(unsigned char *key)
372{
373}
374static void nullmac_generate(unsigned char *blk, int len,
375 unsigned long seq)
376{
377}
378static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
379{
380 return 1;
381}
57476f6b 382const static struct ssh_mac ssh_mac_none = {
d39f364a 383 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 384};
8b2715b2 385const static struct ssh_mac *macs[] = {
32874aea 386 &ssh_sha1, &ssh_md5, &ssh_mac_none
387};
8b2715b2 388const static struct ssh_mac *buggymacs[] = {
32874aea 389 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
390};
e5574168 391
32874aea 392static void ssh_comp_none_init(void)
393{
394}
4ba9b64b 395static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 396 unsigned char **outblock, int *outlen)
397{
398 return 0;
399}
400static int ssh_comp_none_disable(void)
401{
4ba9b64b 402 return 0;
403}
57476f6b 404const static struct ssh_compress ssh_comp_none = {
4ba9b64b 405 "none",
406 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 407 ssh_comp_none_init, ssh_comp_none_block,
408 ssh_comp_none_disable
e5574168 409};
4ba9b64b 410extern const struct ssh_compress ssh_zlib;
411const static struct ssh_compress *compressions[] = {
32874aea 412 &ssh_zlib, &ssh_comp_none
413};
374330e2 414
32874aea 415enum { /* channel types */
783415f8 416 CHAN_MAINSESSION,
417 CHAN_X11,
418 CHAN_AGENT,
bc240b21 419 CHAN_SOCKDATA,
420 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 421};
422
dacbd0e8 423/*
424 * 2-3-4 tree storing channels.
425 */
426struct ssh_channel {
d211621f 427 unsigned remoteid, localid;
dacbd0e8 428 int type;
429 int closes;
5471d09a 430 union {
431 struct ssh1_data_channel {
432 int throttling;
433 } v1;
434 struct ssh2_data_channel {
435 bufchain outbuffer;
436 unsigned remwindow, remmaxpkt;
437 unsigned locwindow;
438 } v2;
439 } v;
dacbd0e8 440 union {
32874aea 441 struct ssh_agent_channel {
442 unsigned char *message;
443 unsigned char msglen[4];
444 int lensofar, totallen;
445 } a;
446 struct ssh_x11_channel {
447 Socket s;
448 } x11;
d74d141c 449 struct ssh_pfd_channel {
450 Socket s;
451 } pfd;
dacbd0e8 452 } u;
453};
57476f6b 454
d74d141c 455/*
bc240b21 456 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
457 * 2 use this structure in different ways, reflecting SSH 2's
458 * altogether saner approach to port forwarding.
459 *
460 * In SSH 1, you arrange a remote forwarding by sending the server
461 * the remote port number, and the local destination host:port.
462 * When a connection comes in, the server sends you back that
463 * host:port pair, and you connect to it. This is a ready-made
464 * security hole if you're not on the ball: a malicious server
465 * could send you back _any_ host:port pair, so if you trustingly
466 * connect to the address it gives you then you've just opened the
467 * entire inside of your corporate network just by connecting
468 * through it to a dodgy SSH server. Hence, we must store a list of
469 * host:port pairs we _are_ trying to forward to, and reject a
470 * connection request from the server if it's not in the list.
471 *
472 * In SSH 2, each side of the connection minds its own business and
473 * doesn't send unnecessary information to the other. You arrange a
474 * remote forwarding by sending the server just the remote port
475 * number. When a connection comes in, the server tells you which
476 * of its ports was connected to; and _you_ have to remember what
477 * local host:port pair went with that port number.
478 *
479 * Hence: in SSH 1 this structure stores host:port pairs we intend
480 * to allow connections to, and is indexed by those host:port
481 * pairs. In SSH 2 it stores a mapping from source port to
482 * destination host:port pair, and is indexed by source port.
d74d141c 483 */
484struct ssh_rportfwd {
bc240b21 485 unsigned sport, dport;
486 char dhost[256];
d74d141c 487};
488
57476f6b 489struct Packet {
490 long length;
491 int type;
492 unsigned char *data;
493 unsigned char *body;
494 long savedpos;
495 long maxlen;
496};
497
0db56f73 498static SHA_State exhash, exhashbase;
57476f6b 499
8df7a775 500static Socket s = NULL;
57476f6b 501
502static unsigned char session_key[32];
4ba9b64b 503static int ssh1_compressing;
b96dc54c 504static int ssh1_remote_protoflags;
505static int ssh1_local_protoflags;
db7d555c 506static int ssh_agentfwd_enabled;
9c964e85 507static int ssh_X11_fwd_enabled;
7d503c31 508static int ssh_remote_bugs;
57476f6b 509static const struct ssh_cipher *cipher = NULL;
0a3f1d48 510static const struct ssh2_cipher *cscipher = NULL;
511static const struct ssh2_cipher *sccipher = NULL;
57476f6b 512static const struct ssh_mac *csmac = NULL;
513static const struct ssh_mac *scmac = NULL;
514static const struct ssh_compress *cscomp = NULL;
515static const struct ssh_compress *sccomp = NULL;
516static const struct ssh_kex *kex = NULL;
e055a386 517static const struct ssh_signkey *hostkey = NULL;
65a22376 518static unsigned char ssh2_session_id[20];
57476f6b 519
520static char *savedhost;
521static int savedport;
522static int ssh_send_ok;
0965bee0 523static int ssh_echoing, ssh_editing;
57476f6b 524
32874aea 525static tree234 *ssh_channels; /* indexed by local id */
57476f6b 526static struct ssh_channel *mainchan; /* primary session channel */
d8d6c7e5 527static int ssh_exitcode = -1;
57476f6b 528
d74d141c 529static tree234 *ssh_rportfwds;
530
57476f6b 531static enum {
3687d221 532 SSH_STATE_PREPACKET,
57476f6b 533 SSH_STATE_BEFORE_SIZE,
534 SSH_STATE_INTERMED,
535 SSH_STATE_SESSION,
536 SSH_STATE_CLOSED
3687d221 537} ssh_state = SSH_STATE_PREPACKET;
57476f6b 538
3687d221 539static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 540
541static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
542static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 543static unsigned char *deferred_send_data = NULL;
544static int deferred_len = 0, deferred_size = 0;
57476f6b 545
fd5e5847 546/*
547 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
548 * that fails. This variable is the means by which scp.c can reach
549 * into the SSH code and find out which one it got.
550 */
551int ssh_fallback_cmd = 0;
552
57476f6b 553static int ssh_version;
5471d09a 554static int ssh1_throttle_count;
555static int ssh_overall_bufsize;
556static int ssh_throttled_all;
557static int ssh1_stdout_throttling;
32874aea 558static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 559static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
560static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
561static void ssh_size(void);
32874aea 562static void ssh_special(Telnet_Special);
5471d09a 563static int ssh2_try_send(struct ssh_channel *c);
32874aea 564static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
565 int len);
5471d09a 566static void ssh_throttle_all(int enable, int bufsize);
567static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 568static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 569static int ssh_sendbuffer(void);
57476f6b 570
571static struct rdpkt1_state_tag {
572 long len, pad, biglen, to_read;
573 unsigned long realcrc, gotcrc;
574 unsigned char *p;
575 int i;
576 int chunk;
577} rdpkt1_state;
578
960e736a 579static struct rdpkt2_state_tag {
580 long len, pad, payload, packetlen, maclen;
581 int i;
582 int cipherblk;
583 unsigned long incoming_sequence;
584} rdpkt2_state;
585
32874aea 586static int ssh_channelcmp(void *av, void *bv)
587{
588 struct ssh_channel *a = (struct ssh_channel *) av;
589 struct ssh_channel *b = (struct ssh_channel *) bv;
590 if (a->localid < b->localid)
591 return -1;
592 if (a->localid > b->localid)
593 return +1;
dacbd0e8 594 return 0;
595}
32874aea 596static int ssh_channelfind(void *av, void *bv)
597{
598 unsigned *a = (unsigned *) av;
599 struct ssh_channel *b = (struct ssh_channel *) bv;
600 if (*a < b->localid)
601 return -1;
602 if (*a > b->localid)
603 return +1;
dacbd0e8 604 return 0;
605}
606
bc240b21 607static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 608{
609 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
610 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
611 int i;
bc240b21 612 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 613 return i < 0 ? -1 : +1;
bc240b21 614 if (a->dport > b->dport)
615 return +1;
616 if (a->dport < b->dport)
617 return -1;
618 return 0;
619}
620
621static int ssh_rportcmp_ssh2(void *av, void *bv)
622{
623 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
624 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 625
bc240b21 626 if (a->sport > b->sport)
d74d141c 627 return +1;
bc240b21 628 if (a->sport < b->sport)
629 return -1;
d74d141c 630 return 0;
631}
632
32874aea 633static int alloc_channel_id(void)
634{
260f3dec 635 const unsigned CHANNEL_NUMBER_OFFSET = 256;
636 unsigned low, high, mid;
d2371c81 637 int tsize;
638 struct ssh_channel *c;
639
640 /*
641 * First-fit allocation of channel numbers: always pick the
642 * lowest unused one. To do this, binary-search using the
643 * counted B-tree to find the largest channel ID which is in a
644 * contiguous sequence from the beginning. (Precisely
645 * everything in that sequence must have ID equal to its tree
646 * index plus CHANNEL_NUMBER_OFFSET.)
647 */
648 tsize = count234(ssh_channels);
649
32874aea 650 low = -1;
651 high = tsize;
d2371c81 652 while (high - low > 1) {
653 mid = (high + low) / 2;
654 c = index234(ssh_channels, mid);
655 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
656 low = mid; /* this one is fine */
657 else
658 high = mid; /* this one is past it */
659 }
660 /*
661 * Now low points to either -1, or the tree index of the
662 * largest ID in the initial sequence.
663 */
664 {
665 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
666 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
667 }
668 return low + 1 + CHANNEL_NUMBER_OFFSET;
669}
670
32874aea 671static void c_write(char *buf, int len)
672{
67779be7 673 if ((flags & FLAG_STDERR)) {
32874aea 674 int i;
675 for (i = 0; i < len; i++)
676 if (buf[i] != '\r')
677 fputc(buf[i], stderr);
fb09bf1c 678 return;
679 }
fe50e814 680 from_backend(1, buf, len);
3bdaf79d 681}
682
32874aea 683static void c_write_untrusted(char *buf, int len)
684{
a209e957 685 int i;
686 for (i = 0; i < len; i++) {
32874aea 687 if (buf[i] == '\n')
688 c_write("\r\n", 2);
689 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
690 c_write(buf + i, 1);
a209e957 691 }
692}
693
32874aea 694static void c_write_str(char *buf)
695{
1408a877 696 c_write(buf, strlen(buf));
697}
698
fb09bf1c 699/*
700 * Collect incoming data in the incoming packet buffer.
e5574168 701 * Decipher and verify the packet when it is completely read.
702 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 703 * Update the *data and *datalen variables.
704 * Return the additional nr of bytes needed, or 0 when
705 * a complete packet is available.
706 */
e5574168 707static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 708{
57476f6b 709 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 710
711 crBegin;
374330e2 712
32874aea 713 next_packet:
37508af4 714
fb09bf1c 715 pktin.type = 0;
716 pktin.length = 0;
374330e2 717
57476f6b 718 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 719 while ((*datalen) == 0)
32874aea 720 crReturn(4 - st->i);
57476f6b 721 st->len = (st->len << 8) + **data;
fb09bf1c 722 (*data)++, (*datalen)--;
723 }
374330e2 724
57476f6b 725 st->pad = 8 - (st->len % 8);
726 st->biglen = st->len + st->pad;
727 pktin.length = st->len - 5;
fb09bf1c 728
57476f6b 729 if (pktin.maxlen < st->biglen) {
730 pktin.maxlen = st->biglen;
32874aea 731 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
732 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 733 if (!pktin.data)
734 fatalbox("Out of memory");
735 }
374330e2 736
57476f6b 737 st->to_read = st->biglen;
738 st->p = pktin.data;
739 while (st->to_read > 0) {
32874aea 740 st->chunk = st->to_read;
fb09bf1c 741 while ((*datalen) == 0)
57476f6b 742 crReturn(st->to_read);
743 if (st->chunk > (*datalen))
744 st->chunk = (*datalen);
745 memcpy(st->p, *data, st->chunk);
746 *data += st->chunk;
747 *datalen -= st->chunk;
748 st->p += st->chunk;
749 st->to_read -= st->chunk;
fb09bf1c 750 }
374330e2 751
9a3a93a5 752 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
753 bombout(("Network attack (CRC compensation) detected!"));
754 crReturn(0);
755 }
756
fb09bf1c 757 if (cipher)
57476f6b 758 cipher->decrypt(pktin.data, st->biglen);
374330e2 759
32874aea 760 st->realcrc = crc32(pktin.data, st->biglen - 4);
761 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 762 if (st->gotcrc != st->realcrc) {
8d5de777 763 bombout(("Incorrect CRC received on packet"));
32874aea 764 crReturn(0);
fb09bf1c 765 }
572f871e 766
4ba9b64b 767 pktin.body = pktin.data + st->pad + 1;
768
769 if (ssh1_compressing) {
770 unsigned char *decompblk;
771 int decomplen;
32874aea 772 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 773 &decompblk, &decomplen);
774
775 if (pktin.maxlen < st->pad + decomplen) {
776 pktin.maxlen = st->pad + decomplen;
32874aea 777 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
778 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 779 if (!pktin.data)
780 fatalbox("Out of memory");
781 }
782
32874aea 783 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 784 sfree(decompblk);
32874aea 785 pktin.length = decomplen - 1;
4ba9b64b 786 }
787
00db133f 788 pktin.type = pktin.body[-1];
789
790 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
791 pktin.body, pktin.length);
792
e5574168 793 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 794 pktin.type == SSH1_SMSG_STDERR_DATA ||
795 pktin.type == SSH1_MSG_DEBUG ||
796 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
797 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3d63ca2e 798 long stringlen = GET_32BIT(pktin.body);
799 if (stringlen + 4 != pktin.length) {
8d5de777 800 bombout(("Received data packet with bogus string length"));
32874aea 801 crReturn(0);
802 }
fb09bf1c 803 }
804
e5574168 805 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 806 /* log debug message */
eb4504cc 807 char buf[512];
3d63ca2e 808 int stringlen = GET_32BIT(pktin.body);
eb4504cc 809 strcpy(buf, "Remote debug message: ");
810 if (stringlen > 480)
811 stringlen = 480;
3d63ca2e 812 memcpy(buf + 8, pktin.body + 4, stringlen);
813 buf[8 + stringlen] = '\0';
fb09bf1c 814 logevent(buf);
815 goto next_packet;
e5574168 816 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 817 /* do nothing */
818 goto next_packet;
819 }
820
38c4a8da 821 if (pktin.type == SSH1_MSG_DISCONNECT) {
822 /* log reason code in disconnect message */
823 char buf[256];
260f3dec 824 unsigned msglen = GET_32BIT(pktin.body);
825 unsigned nowlen;
38c4a8da 826 strcpy(buf, "Remote sent disconnect: ");
827 nowlen = strlen(buf);
32874aea 828 if (msglen > sizeof(buf) - nowlen - 1)
829 msglen = sizeof(buf) - nowlen - 1;
830 memcpy(buf + nowlen, pktin.body + 4, msglen);
831 buf[nowlen + msglen] = '\0';
247308b5 832 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 833 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 834 crReturn(0);
38c4a8da 835 }
836
fb09bf1c 837 crFinish(0);
838}
839
e5574168 840static int ssh2_rdpkt(unsigned char **data, int *datalen)
841{
960e736a 842 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 843
844 crBegin;
845
32874aea 846 next_packet:
e5574168 847 pktin.type = 0;
848 pktin.length = 0;
960e736a 849 if (sccipher)
32874aea 850 st->cipherblk = sccipher->blksize;
e5574168 851 else
32874aea 852 st->cipherblk = 8;
960e736a 853 if (st->cipherblk < 8)
32874aea 854 st->cipherblk = 8;
960e736a 855
856 if (pktin.maxlen < st->cipherblk) {
857 pktin.maxlen = st->cipherblk;
32874aea 858 pktin.data =
859 (pktin.data ==
860 NULL ? smalloc(st->cipherblk +
861 APIEXTRA) : srealloc(pktin.data,
862 st->cipherblk +
863 APIEXTRA));
e5574168 864 if (!pktin.data)
865 fatalbox("Out of memory");
866 }
867
868 /*
869 * Acquire and decrypt the first block of the packet. This will
870 * contain the length and padding details.
871 */
32874aea 872 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 873 while ((*datalen) == 0)
32874aea 874 crReturn(st->cipherblk - st->i);
960e736a 875 pktin.data[st->i] = *(*data)++;
32874aea 876 (*datalen)--;
e5574168 877 }
4252c9cc 878
e5574168 879 if (sccipher)
32874aea 880 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 881
882 /*
883 * Now get the length and padding figures.
884 */
960e736a 885 st->len = GET_32BIT(pktin.data);
886 st->pad = pktin.data[4];
e5574168 887
888 /*
717dc483 889 * _Completely_ silly lengths should be stomped on before they
890 * do us any more damage.
891 */
892 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
893 bombout(("Incoming packet was garbled on decryption"));
894 crReturn(0);
895 }
896
897 /*
e5574168 898 * This enables us to deduce the payload length.
899 */
960e736a 900 st->payload = st->len - st->pad - 1;
e5574168 901
960e736a 902 pktin.length = st->payload + 5;
e5574168 903
904 /*
905 * So now we can work out the total packet length.
906 */
960e736a 907 st->packetlen = st->len + 4;
908 st->maclen = scmac ? scmac->len : 0;
e5574168 909
910 /*
911 * Adjust memory allocation if packet is too big.
912 */
32874aea 913 if (pktin.maxlen < st->packetlen + st->maclen) {
914 pktin.maxlen = st->packetlen + st->maclen;
915 pktin.data =
916 (pktin.data ==
917 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
918 pktin.maxlen
919 +
920 APIEXTRA));
e5574168 921 if (!pktin.data)
922 fatalbox("Out of memory");
923 }
924
925 /*
926 * Read and decrypt the remainder of the packet.
927 */
32874aea 928 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
929 st->i++) {
e5574168 930 while ((*datalen) == 0)
960e736a 931 crReturn(st->packetlen + st->maclen - st->i);
932 pktin.data[st->i] = *(*data)++;
32874aea 933 (*datalen)--;
e5574168 934 }
935 /* Decrypt everything _except_ the MAC. */
936 if (sccipher)
32874aea 937 sccipher->decrypt(pktin.data + st->cipherblk,
938 st->packetlen - st->cipherblk);
e5574168 939
940 /*
941 * Check the MAC.
942 */
32874aea 943 if (scmac
944 && !scmac->verify(pktin.data, st->len + 4,
945 st->incoming_sequence)) {
8d5de777 946 bombout(("Incorrect MAC received on packet"));
32874aea 947 crReturn(0);
8d5de777 948 }
32874aea 949 st->incoming_sequence++; /* whether or not we MACed */
e5574168 950
4ba9b64b 951 /*
952 * Decompress packet payload.
953 */
954 {
955 unsigned char *newpayload;
956 int newlen;
32874aea 957 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 958 &newpayload, &newlen)) {
32874aea 959 if (pktin.maxlen < newlen + 5) {
960 pktin.maxlen = newlen + 5;
961 pktin.data =
962 (pktin.data ==
963 NULL ? smalloc(pktin.maxlen +
964 APIEXTRA) : srealloc(pktin.data,
965 pktin.maxlen +
966 APIEXTRA));
4ba9b64b 967 if (!pktin.data)
968 fatalbox("Out of memory");
969 }
970 pktin.length = 5 + newlen;
32874aea 971 memcpy(pktin.data + 5, newpayload, newlen);
dcbde236 972 sfree(newpayload);
4ba9b64b 973 }
974 }
975
e5574168 976 pktin.savedpos = 6;
977 pktin.type = pktin.data[5];
e5574168 978
00db133f 979 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
980 pktin.data+6, pktin.length-6);
981
3d63ca2e 982 switch (pktin.type) {
983 /*
984 * These packets we must handle instantly.
985 */
986 case SSH2_MSG_DISCONNECT:
987 {
988 /* log reason code in disconnect message */
989 char buf[256];
990 int reason = GET_32BIT(pktin.data + 6);
991 unsigned msglen = GET_32BIT(pktin.data + 10);
992 unsigned nowlen;
993 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
994 sprintf(buf, "Received disconnect message (%s)",
995 ssh2_disconnect_reasons[reason]);
996 } else {
997 sprintf(buf, "Received disconnect message (unknown type %d)",
998 reason);
999 }
1000 logevent(buf);
1001 strcpy(buf, "Disconnection message text: ");
1002 nowlen = strlen(buf);
1003 if (msglen > sizeof(buf) - nowlen - 1)
1004 msglen = sizeof(buf) - nowlen - 1;
1005 memcpy(buf + nowlen, pktin.data + 14, msglen);
1006 buf[nowlen + msglen] = '\0';
1007 logevent(buf);
1008 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1009 reason,
1010 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1011 ssh2_disconnect_reasons[reason] : "unknown",
1012 buf+nowlen));
1013 crReturn(0);
1014 }
1015 break;
1016 case SSH2_MSG_IGNORE:
1017 goto next_packet;
1018 case SSH2_MSG_DEBUG:
1019 {
1020 /* log the debug message */
1021 char buf[512];
1022 /* int display = pktin.body[6]; */
1023 int stringlen = GET_32BIT(pktin.data+7);
1024 int prefix;
1025 strcpy(buf, "Remote debug message: ");
1026 prefix = strlen(buf);
1027 if (stringlen > sizeof(buf)-prefix-1)
1028 stringlen = sizeof(buf)-prefix-1;
1029 memcpy(buf + prefix, pktin.data + 11, stringlen);
1030 buf[prefix + stringlen] = '\0';
1031 logevent(buf);
38c4a8da 1032 }
3d63ca2e 1033 goto next_packet; /* FIXME: print the debug message */
1034
1035 /*
1036 * These packets we need do nothing about here.
1037 */
1038 case SSH2_MSG_UNIMPLEMENTED:
1039 case SSH2_MSG_SERVICE_REQUEST:
1040 case SSH2_MSG_SERVICE_ACCEPT:
1041 case SSH2_MSG_KEXINIT:
1042 case SSH2_MSG_NEWKEYS:
1043 case SSH2_MSG_KEXDH_INIT:
1044 case SSH2_MSG_KEXDH_REPLY:
1045 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1046 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1047 case SSH2_MSG_KEX_DH_GEX_INIT:
1048 case SSH2_MSG_KEX_DH_GEX_REPLY:
1049 case SSH2_MSG_USERAUTH_REQUEST:
1050 case SSH2_MSG_USERAUTH_FAILURE:
1051 case SSH2_MSG_USERAUTH_SUCCESS:
1052 case SSH2_MSG_USERAUTH_BANNER:
1053 case SSH2_MSG_USERAUTH_PK_OK:
1054 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1055 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1056 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1057 case SSH2_MSG_GLOBAL_REQUEST:
1058 case SSH2_MSG_REQUEST_SUCCESS:
1059 case SSH2_MSG_REQUEST_FAILURE:
1060 case SSH2_MSG_CHANNEL_OPEN:
1061 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1062 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1063 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1064 case SSH2_MSG_CHANNEL_DATA:
1065 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1066 case SSH2_MSG_CHANNEL_EOF:
1067 case SSH2_MSG_CHANNEL_CLOSE:
1068 case SSH2_MSG_CHANNEL_REQUEST:
1069 case SSH2_MSG_CHANNEL_SUCCESS:
1070 case SSH2_MSG_CHANNEL_FAILURE:
1071 break;
1072
1073 /*
1074 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1075 */
1076 default:
1077 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1078 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1079 ssh2_pkt_send();
1080 break;
38c4a8da 1081 }
1082
e5574168 1083 crFinish(0);
1084}
1085
32874aea 1086static void ssh1_pktout_size(int len)
1087{
374330e2 1088 int pad, biglen;
1089
1090 len += 5; /* type and CRC */
32874aea 1091 pad = 8 - (len % 8);
374330e2 1092 biglen = len + pad;
1093
32874aea 1094 pktout.length = len - 5;
374330e2 1095 if (pktout.maxlen < biglen) {
1096 pktout.maxlen = biglen;
8f203108 1097#ifdef MSCRYPTOAPI
fb09bf1c 1098 /* Allocate enough buffer space for extra block
8f203108 1099 * for MS CryptEncrypt() */
32874aea 1100 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1101 srealloc(pktout.data, biglen + 12));
8f203108 1102#else
32874aea 1103 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1104 srealloc(pktout.data, biglen + 4));
8f203108 1105#endif
374330e2 1106 if (!pktout.data)
1107 fatalbox("Out of memory");
1108 }
32874aea 1109 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 1110}
374330e2 1111
32874aea 1112static void s_wrpkt_start(int type, int len)
1113{
4ba9b64b 1114 ssh1_pktout_size(len);
374330e2 1115 pktout.type = type;
374330e2 1116}
1117
32874aea 1118static int s_wrpkt_prepare(void)
1119{
374330e2 1120 int pad, len, biglen, i;
1121 unsigned long crc;
1122
4ba9b64b 1123 pktout.body[-1] = pktout.type;
1124
00db133f 1125 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1126 pktout.body, pktout.length);
1127
4ba9b64b 1128 if (ssh1_compressing) {
1129 unsigned char *compblk;
1130 int complen;
32874aea 1131 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 1132 &compblk, &complen);
32874aea 1133 ssh1_pktout_size(complen - 1);
1134 memcpy(pktout.body - 1, compblk, complen);
dcbde236 1135 sfree(compblk);
4ba9b64b 1136 }
1137
374330e2 1138 len = pktout.length + 5; /* type and CRC */
32874aea 1139 pad = 8 - (len % 8);
374330e2 1140 biglen = len + pad;
1141
32874aea 1142 for (i = 0; i < pad; i++)
1143 pktout.data[i + 4] = random_byte();
1144 crc = crc32(pktout.data + 4, biglen - 4);
1145 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 1146 PUT_32BIT(pktout.data, len);
374330e2 1147
1148 if (cipher)
32874aea 1149 cipher->encrypt(pktout.data + 4, biglen);
374330e2 1150
32874aea 1151 return biglen + 4;
39065bed 1152}
1153
32874aea 1154static void s_wrpkt(void)
1155{
5471d09a 1156 int len, backlog;
39065bed 1157 len = s_wrpkt_prepare();
5471d09a 1158 backlog = sk_write(s, pktout.data, len);
1159 if (backlog > SSH_MAX_BACKLOG)
1160 ssh_throttle_all(1, backlog);
39065bed 1161}
1162
32874aea 1163static void s_wrpkt_defer(void)
1164{
39065bed 1165 int len;
1166 len = s_wrpkt_prepare();
1167 if (deferred_len + len > deferred_size) {
32874aea 1168 deferred_size = deferred_len + len + 128;
1169 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1170 }
32874aea 1171 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1172 deferred_len += len;
374330e2 1173}
1174
fb09bf1c 1175/*
39065bed 1176 * Construct a packet with the specified contents.
fb09bf1c 1177 */
39065bed 1178static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1179{
fb09bf1c 1180 unsigned char *p, *argp, argchar;
1181 unsigned long argint;
1182 int pktlen, argtype, arglen;
7cca0d81 1183 Bignum bn;
fb09bf1c 1184
1185 pktlen = 0;
39065bed 1186 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1187 switch (argtype) {
1188 case PKT_INT:
39065bed 1189 (void) va_arg(ap1, int);
fb09bf1c 1190 pktlen += 4;
1191 break;
1192 case PKT_CHAR:
39065bed 1193 (void) va_arg(ap1, char);
fb09bf1c 1194 pktlen++;
1195 break;
1196 case PKT_DATA:
39065bed 1197 (void) va_arg(ap1, unsigned char *);
1198 arglen = va_arg(ap1, int);
fb09bf1c 1199 pktlen += arglen;
1200 break;
1201 case PKT_STR:
39065bed 1202 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1203 arglen = strlen(argp);
1204 pktlen += 4 + arglen;
1205 break;
7cca0d81 1206 case PKT_BIGNUM:
39065bed 1207 bn = va_arg(ap1, Bignum);
32874aea 1208 pktlen += ssh1_bignum_length(bn);
7cca0d81 1209 break;
fb09bf1c 1210 default:
1211 assert(0);
1212 }
1213 }
fb09bf1c 1214
1215 s_wrpkt_start(pkttype, pktlen);
1216 p = pktout.body;
1217
39065bed 1218 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1219 switch (argtype) {
1220 case PKT_INT:
39065bed 1221 argint = va_arg(ap2, int);
fb09bf1c 1222 PUT_32BIT(p, argint);
1223 p += 4;
1224 break;
1225 case PKT_CHAR:
39065bed 1226 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1227 *p = argchar;
1228 p++;
1229 break;
1230 case PKT_DATA:
39065bed 1231 argp = va_arg(ap2, unsigned char *);
1232 arglen = va_arg(ap2, int);
fb09bf1c 1233 memcpy(p, argp, arglen);
1234 p += arglen;
1235 break;
1236 case PKT_STR:
39065bed 1237 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1238 arglen = strlen(argp);
1239 PUT_32BIT(p, arglen);
1240 memcpy(p + 4, argp, arglen);
1241 p += 4 + arglen;
1242 break;
7cca0d81 1243 case PKT_BIGNUM:
39065bed 1244 bn = va_arg(ap2, Bignum);
32874aea 1245 p += ssh1_write_bignum(p, bn);
7cca0d81 1246 break;
fb09bf1c 1247 }
1248 }
39065bed 1249}
fb09bf1c 1250
32874aea 1251static void send_packet(int pkttype, ...)
1252{
39065bed 1253 va_list ap1, ap2;
1254 va_start(ap1, pkttype);
1255 va_start(ap2, pkttype);
1256 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1257 s_wrpkt();
1258}
1259
32874aea 1260static void defer_packet(int pkttype, ...)
1261{
39065bed 1262 va_list ap1, ap2;
1263 va_start(ap1, pkttype);
1264 va_start(ap2, pkttype);
1265 construct_packet(pkttype, ap1, ap2);
1266 s_wrpkt_defer();
1267}
1268
32874aea 1269static int ssh_versioncmp(char *a, char *b)
1270{
9697bfd2 1271 char *ae, *be;
1272 unsigned long av, bv;
1273
43aa02a7 1274 av = strtoul(a, &ae, 10);
1275 bv = strtoul(b, &be, 10);
32874aea 1276 if (av != bv)
1277 return (av < bv ? -1 : +1);
1278 if (*ae == '.')
1279 ae++;
1280 if (*be == '.')
1281 be++;
43aa02a7 1282 av = strtoul(ae, &ae, 10);
1283 bv = strtoul(be, &be, 10);
32874aea 1284 if (av != bv)
1285 return (av < bv ? -1 : +1);
9697bfd2 1286 return 0;
1287}
1288
e5574168 1289
1290/*
a92dd380 1291 * Utility routines for putting an SSH-protocol `string' and
1292 * `uint32' into a SHA state.
e5574168 1293 */
1294#include <stdio.h>
32874aea 1295static void sha_string(SHA_State * s, void *str, int len)
1296{
e5574168 1297 unsigned char lenblk[4];
e5574168 1298 PUT_32BIT(lenblk, len);
e5574168 1299 SHA_Bytes(s, lenblk, 4);
e5574168 1300 SHA_Bytes(s, str, len);
1301}
1302
32874aea 1303static void sha_uint32(SHA_State * s, unsigned i)
1304{
a92dd380 1305 unsigned char intblk[4];
1306 PUT_32BIT(intblk, i);
1307 SHA_Bytes(s, intblk, 4);
1308}
1309
7cca0d81 1310/*
1311 * SSH2 packet construction functions.
1312 */
32874aea 1313static void ssh2_pkt_ensure(int length)
1314{
783415f8 1315 if (pktout.maxlen < length) {
32874aea 1316 pktout.maxlen = length + 256;
1317 pktout.data =
1318 (pktout.data ==
1319 NULL ? smalloc(pktout.maxlen +
1320 APIEXTRA) : srealloc(pktout.data,
1321 pktout.maxlen +
1322 APIEXTRA));
1323 if (!pktout.data)
1324 fatalbox("Out of memory");
7cca0d81 1325 }
783415f8 1326}
32874aea 1327static void ssh2_pkt_adddata(void *data, int len)
1328{
783415f8 1329 pktout.length += len;
1330 ssh2_pkt_ensure(pktout.length);
32874aea 1331 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1332}
32874aea 1333static void ssh2_pkt_addbyte(unsigned char byte)
1334{
7cca0d81 1335 ssh2_pkt_adddata(&byte, 1);
1336}
32874aea 1337static void ssh2_pkt_init(int pkt_type)
1338{
7cca0d81 1339 pktout.length = 5;
32874aea 1340 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1341}
32874aea 1342static void ssh2_pkt_addbool(unsigned char value)
1343{
7cca0d81 1344 ssh2_pkt_adddata(&value, 1);
1345}
32874aea 1346static void ssh2_pkt_adduint32(unsigned long value)
1347{
7cca0d81 1348 unsigned char x[4];
1349 PUT_32BIT(x, value);
1350 ssh2_pkt_adddata(x, 4);
1351}
32874aea 1352static void ssh2_pkt_addstring_start(void)
1353{
7cca0d81 1354 ssh2_pkt_adduint32(0);
1355 pktout.savedpos = pktout.length;
1356}
32874aea 1357static void ssh2_pkt_addstring_str(char *data)
1358{
7cca0d81 1359 ssh2_pkt_adddata(data, strlen(data));
1360 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1361 pktout.length - pktout.savedpos);
7cca0d81 1362}
32874aea 1363static void ssh2_pkt_addstring_data(char *data, int len)
1364{
7cca0d81 1365 ssh2_pkt_adddata(data, len);
1366 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1367 pktout.length - pktout.savedpos);
7cca0d81 1368}
32874aea 1369static void ssh2_pkt_addstring(char *data)
1370{
7cca0d81 1371 ssh2_pkt_addstring_start();
1372 ssh2_pkt_addstring_str(data);
1373}
32874aea 1374static char *ssh2_mpint_fmt(Bignum b, int *len)
1375{
7cca0d81 1376 unsigned char *p;
32874aea 1377 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1378 p = smalloc(n + 1);
7cca0d81 1379 if (!p)
32874aea 1380 fatalbox("out of memory");
7cca0d81 1381 p[0] = 0;
3709bfe9 1382 for (i = 1; i <= n; i++)
32874aea 1383 p[i] = bignum_byte(b, n - i);
7cca0d81 1384 i = 0;
32874aea 1385 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1386 i++;
1387 memmove(p, p + i, n + 1 - i);
1388 *len = n + 1 - i;
7cca0d81 1389 return p;
1390}
32874aea 1391static void ssh2_pkt_addmp(Bignum b)
1392{
7cca0d81 1393 unsigned char *p;
1394 int len;
1395 p = ssh2_mpint_fmt(b, &len);
1396 ssh2_pkt_addstring_start();
1397 ssh2_pkt_addstring_data(p, len);
dcbde236 1398 sfree(p);
7cca0d81 1399}
b185170a 1400
1401/*
1402 * Construct an SSH2 final-form packet: compress it, encrypt it,
1403 * put the MAC on it. Final packet, ready to be sent, is stored in
1404 * pktout.data. Total length is returned.
1405 */
32874aea 1406static int ssh2_pkt_construct(void)
1407{
7cca0d81 1408 int cipherblk, maclen, padding, i;
1409 static unsigned long outgoing_sequence = 0;
1410
00db133f 1411 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1412 pktout.data + 6, pktout.length - 6);
1413
7cca0d81 1414 /*
4ba9b64b 1415 * Compress packet payload.
1416 */
4ba9b64b 1417 {
1418 unsigned char *newpayload;
1419 int newlen;
32874aea 1420 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1421 &newpayload, &newlen)) {
1422 pktout.length = 5;
1423 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1424 sfree(newpayload);
4ba9b64b 1425 }
1426 }
1427
1428 /*
7cca0d81 1429 * Add padding. At least four bytes, and must also bring total
1430 * length (minus MAC) up to a multiple of the block size.
1431 */
32874aea 1432 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1433 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1434 padding = 4;
32874aea 1435 padding +=
1436 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1437 maclen = csmac ? csmac->len : 0;
1438 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1439 pktout.data[4] = padding;
1440 for (i = 0; i < padding; i++)
32874aea 1441 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1442 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1443 if (csmac)
32874aea 1444 csmac->generate(pktout.data, pktout.length + padding,
1445 outgoing_sequence);
1446 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1447
7cca0d81 1448 if (cscipher)
32874aea 1449 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1450
b185170a 1451 /* Ready-to-send packet starts at pktout.data. We return length. */
1452 return pktout.length + padding + maclen;
1453}
1454
1455/*
1456 * Construct and send an SSH2 packet immediately.
1457 */
32874aea 1458static void ssh2_pkt_send(void)
1459{
5471d09a 1460 int len;
1461 int backlog;
1462 len = ssh2_pkt_construct();
1463 backlog = sk_write(s, pktout.data, len);
1464 if (backlog > SSH_MAX_BACKLOG)
1465 ssh_throttle_all(1, backlog);
b185170a 1466}
1467
1468/*
1469 * Construct an SSH2 packet and add it to a deferred data block.
1470 * Useful for sending multiple packets in a single sk_write() call,
1471 * to prevent a traffic-analysing listener from being able to work
1472 * out the length of any particular packet (such as the password
1473 * packet).
1474 *
1475 * Note that because SSH2 sequence-numbers its packets, this can
1476 * NOT be used as an m4-style `defer' allowing packets to be
1477 * constructed in one order and sent in another.
1478 */
32874aea 1479static void ssh2_pkt_defer(void)
1480{
b185170a 1481 int len = ssh2_pkt_construct();
1482 if (deferred_len + len > deferred_size) {
32874aea 1483 deferred_size = deferred_len + len + 128;
1484 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1485 }
32874aea 1486 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1487 deferred_len += len;
1488}
1489
1490/*
1491 * Send the whole deferred data block constructed by
39065bed 1492 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1493 */
32874aea 1494static void ssh_pkt_defersend(void)
1495{
5471d09a 1496 int backlog;
1497 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1498 deferred_len = deferred_size = 0;
1499 sfree(deferred_send_data);
1500 deferred_send_data = NULL;
5471d09a 1501 if (backlog > SSH_MAX_BACKLOG)
1502 ssh_throttle_all(1, backlog);
7cca0d81 1503}
1504
1505#if 0
32874aea 1506void bndebug(char *string, Bignum b)
1507{
7cca0d81 1508 unsigned char *p;
1509 int i, len;
1510 p = ssh2_mpint_fmt(b, &len);
1511 debug(("%s", string));
1512 for (i = 0; i < len; i++)
32874aea 1513 debug((" %02x", p[i]));
765c4200 1514 debug(("\n"));
dcbde236 1515 sfree(p);
7cca0d81 1516}
1517#endif
1518
32874aea 1519static void sha_mpint(SHA_State * s, Bignum b)
1520{
7cca0d81 1521 unsigned char *p;
1522 int len;
1523 p = ssh2_mpint_fmt(b, &len);
1524 sha_string(s, p, len);
dcbde236 1525 sfree(p);
7cca0d81 1526}
1527
1528/*
1529 * SSH2 packet decode functions.
1530 */
32874aea 1531static unsigned long ssh2_pkt_getuint32(void)
1532{
7cca0d81 1533 unsigned long value;
1534 if (pktin.length - pktin.savedpos < 4)
32874aea 1535 return 0; /* arrgh, no way to decline (FIXME?) */
1536 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1537 pktin.savedpos += 4;
1538 return value;
1539}
32874aea 1540static int ssh2_pkt_getbool(void)
1541{
65a22376 1542 unsigned long value;
1543 if (pktin.length - pktin.savedpos < 1)
32874aea 1544 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1545 value = pktin.data[pktin.savedpos] != 0;
1546 pktin.savedpos++;
1547 return value;
1548}
32874aea 1549static void ssh2_pkt_getstring(char **p, int *length)
1550{
7cca0d81 1551 *p = NULL;
45068b27 1552 *length = 0;
7cca0d81 1553 if (pktin.length - pktin.savedpos < 4)
32874aea 1554 return;
1555 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1556 pktin.savedpos += 4;
1557 if (pktin.length - pktin.savedpos < *length)
32874aea 1558 return;
1559 *p = pktin.data + pktin.savedpos;
7cca0d81 1560 pktin.savedpos += *length;
1561}
32874aea 1562static Bignum ssh2_pkt_getmp(void)
1563{
7cca0d81 1564 char *p;
3709bfe9 1565 int length;
7cca0d81 1566 Bignum b;
1567
1568 ssh2_pkt_getstring(&p, &length);
1569 if (!p)
32874aea 1570 return NULL;
8d5de777 1571 if (p[0] & 0x80) {
32874aea 1572 bombout(("internal error: Can't handle negative mpints"));
1573 return NULL;
8d5de777 1574 }
3709bfe9 1575 b = bignum_from_bytes(p, length);
7cca0d81 1576 return b;
1577}
1578
7d503c31 1579/*
1dd353b5 1580 * Helper function to add an SSH2 signature blob to a packet.
1581 * Expects to be shown the public key blob as well as the signature
1582 * blob. Normally works just like ssh2_pkt_addstring, but will
1583 * fiddle with the signature packet if necessary for
1584 * BUG_SSH2_RSA_PADDING.
1585 */
1586static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1587 void *sigblob_v, int sigblob_len)
1588{
1589 unsigned char *pkblob = (unsigned char *)pkblob_v;
1590 unsigned char *sigblob = (unsigned char *)sigblob_v;
1591
1592 /* dmemdump(pkblob, pkblob_len); */
1593 /* dmemdump(sigblob, sigblob_len); */
1594
1595 /*
1596 * See if this is in fact an ssh-rsa signature and a buggy
1597 * server; otherwise we can just do this the easy way.
1598 */
1599 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1600 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1601 int pos, len, siglen;
1602
1603 /*
1604 * Find the byte length of the modulus.
1605 */
1606
1607 pos = 4+7; /* skip over "ssh-rsa" */
1608 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1609 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1610 pos += 4; /* find modulus itself */
1611 while (len > 0 && pkblob[pos] == 0)
1612 len--, pos++;
1613 /* debug(("modulus length is %d\n", len)); */
1614
1615 /*
1616 * Now find the signature integer.
1617 */
1618 pos = 4+7; /* skip over "ssh-rsa" */
1619 siglen = GET_32BIT(sigblob+pos);
1620 /* debug(("signature length is %d\n", siglen)); */
1621
1622 if (len != siglen) {
1623 unsigned char newlen[4];
1624 ssh2_pkt_addstring_start();
1625 ssh2_pkt_addstring_data(sigblob, pos);
1626 /* dmemdump(sigblob, pos); */
1627 pos += 4; /* point to start of actual sig */
1628 PUT_32BIT(newlen, len);
1629 ssh2_pkt_addstring_data(newlen, 4);
1630 /* dmemdump(newlen, 4); */
1631 newlen[0] = 0;
1632 while (len-- > siglen) {
1633 ssh2_pkt_addstring_data(newlen, 1);
1634 /* dmemdump(newlen, 1); */
1635 }
1636 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1637 /* dmemdump(sigblob+pos, siglen); */
1638 return;
1639 }
1640
1641 /* Otherwise fall through and do it the easy way. */
1642 }
1643
1644 ssh2_pkt_addstring_start();
1645 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1646}
1647
1648/*
7d503c31 1649 * Examine the remote side's version string and compare it against
1650 * a list of known buggy implementations.
1651 */
32874aea 1652static void ssh_detect_bugs(char *vstring)
1653{
1654 char *imp; /* pointer to implementation part */
7d503c31 1655 imp = vstring;
1656 imp += strcspn(imp, "-");
bd358db1 1657 if (*imp) imp++;
7d503c31 1658 imp += strcspn(imp, "-");
bd358db1 1659 if (*imp) imp++;
7d503c31 1660
1661 ssh_remote_bugs = 0;
1662
1663 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1664 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
bd358db1 1665 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
32874aea 1666 /*
1667 * These versions don't support SSH1_MSG_IGNORE, so we have
1668 * to use a different defence against password length
1669 * sniffing.
1670 */
1671 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1672 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1673 }
1674
bd358db1 1675 if (!strcmp(imp, "Cisco-1.25")) {
1676 /*
1677 * These versions need a plain password sent; they can't
1678 * handle having a null and a random length of data after
1679 * the password.
1680 */
1681 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1682 logevent("We believe remote version needs a plain SSH1 password");
1683 }
1684
0df73905 1685 if (!strcmp(imp, "Cisco-1.25")) {
1686 /*
1687 * These versions apparently have no clue whatever about
1688 * RSA authentication and will panic and die if they see
1689 * an AUTH_RSA message.
1690 */
1691 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1692 logevent("We believe remote version can't handle RSA authentication");
1693 }
1694
7d503c31 1695 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1696 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1697 !strncmp(imp, "2.1 ", 4)) {
1698 /*
1699 * These versions have the HMAC bug.
1700 */
1701 ssh_remote_bugs |= BUG_SSH2_HMAC;
1702 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1703 }
1dd353b5 1704
088bde77 1705 if (!strncmp(imp, "2.0.", 4)) {
1706 /*
1707 * These versions have the key-derivation bug (failing to
1708 * include the literal shared secret in the hashes that
1709 * generate the keys).
1710 */
1711 ssh_remote_bugs |= BUG_SSH2_DERIVEKEY;
1712 logevent("We believe remote version has SSH2 key-derivation bug");
1713 }
1714
1dd353b5 1715 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1716 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1717 /*
1718 * These versions have the SSH2 RSA padding bug.
1719 */
1720 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1721 logevent("We believe remote version has SSH2 RSA padding bug");
1722 }
7d503c31 1723}
1724
32874aea 1725static int do_ssh_init(unsigned char c)
1726{
2d466ffd 1727 static int vslen;
8df7a775 1728 static char version[10];
50526e47 1729 static char *vstring;
1730 static int vstrsize;
1731 static char *vlog;
8df7a775 1732 static int i;
38d228a2 1733 static int proto1, proto2;
374330e2 1734
8df7a775 1735 crBegin;
1736
1737 /* Search for the string "SSH-" in the input. */
374330e2 1738 i = 0;
8df7a775 1739 while (1) {
1740 static const int transS[] = { 1, 2, 2, 1 };
1741 static const int transH[] = { 0, 0, 3, 0 };
1742 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1743 if (c == 'S')
1744 i = transS[i];
1745 else if (c == 'H')
1746 i = transH[i];
1747 else if (c == '-')
1748 i = transminus[i];
1749 else
1750 i = 0;
8df7a775 1751 if (i < 0)
1752 break;
1753 crReturn(1); /* get another character */
374330e2 1754 }
8df7a775 1755
50526e47 1756 vstrsize = 16;
bd358db1 1757 vstring = smalloc(vstrsize);
c5e9c988 1758 strcpy(vstring, "SSH-");
50526e47 1759 vslen = 4;
374330e2 1760 i = 0;
1761 while (1) {
8df7a775 1762 crReturn(1); /* get another char */
32874aea 1763 if (vslen >= vstrsize - 1) {
1764 vstrsize += 16;
1765 vstring = srealloc(vstring, vstrsize);
1766 }
1767 vstring[vslen++] = c;
374330e2 1768 if (i >= 0) {
1769 if (c == '-') {
1770 version[i] = '\0';
1771 i = -1;
32874aea 1772 } else if (i < sizeof(version) - 1)
374330e2 1773 version[i++] = c;
32874aea 1774 } else if (c == '\n')
374330e2 1775 break;
1776 }
1777
db7d555c 1778 ssh_agentfwd_enabled = FALSE;
960e736a 1779 rdpkt2_state.incoming_sequence = 0;
1780
50526e47 1781 vstring[vslen] = 0;
9275ca8a 1782 vlog = smalloc(20 + vslen);
bd358db1 1783 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1784 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1785 logevent(vlog);
bd358db1 1786 ssh_detect_bugs(vstring);
9275ca8a 1787 sfree(vlog);
c5e9c988 1788
adf799dd 1789 /*
38d228a2 1790 * Decide which SSH protocol version to support.
adf799dd 1791 */
38d228a2 1792
1793 /* Anything strictly below "2.0" means protocol 1 is supported. */
1794 proto1 = ssh_versioncmp(version, "2.0") < 0;
1795 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
daa72738 1796 proto2 = ssh_versioncmp(version, "1.99") >= 0;
38d228a2 1797
1798 if (cfg.sshprot == 0 && !proto1) {
1799 bombout(("SSH protocol version 1 required by user but not provided by server"));
1800 crReturn(0);
1801 }
1802 if (cfg.sshprot == 3 && !proto2) {
1803 bombout(("SSH protocol version 2 required by user but not provided by server"));
1804 crReturn(0);
1805 }
1806
daa72738 1807 if (proto2 && (cfg.sshprot >= 2 || !proto1)) {
32874aea 1808 /*
38d228a2 1809 * Use v2 protocol.
32874aea 1810 */
1811 char verstring[80], vlog[100];
1812 sprintf(verstring, "SSH-2.0-%s", sshver);
1813 SHA_Init(&exhashbase);
1814 /*
1815 * Hash our version string and their version string.
1816 */
1817 sha_string(&exhashbase, verstring, strlen(verstring));
1818 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1819 sprintf(vlog, "We claim version: %s", verstring);
1820 logevent(vlog);
1821 strcat(verstring, "\n");
1822 logevent("Using SSH protocol version 2");
1823 sk_write(s, verstring, strlen(verstring));
1824 ssh_protocol = ssh2_protocol;
1825 ssh_version = 2;
1826 s_rdpkt = ssh2_rdpkt;
e5574168 1827 } else {
32874aea 1828 /*
38d228a2 1829 * Use v1 protocol.
32874aea 1830 */
1831 char verstring[80], vlog[100];
1832 sprintf(verstring, "SSH-%s-%s",
1833 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1834 sshver);
1835 sprintf(vlog, "We claim version: %s", verstring);
1836 logevent(vlog);
1837 strcat(verstring, "\n");
759712a6 1838
32874aea 1839 logevent("Using SSH protocol version 1");
1840 sk_write(s, verstring, strlen(verstring));
1841 ssh_protocol = ssh1_protocol;
1842 ssh_version = 1;
1843 s_rdpkt = ssh1_rdpkt;
e5574168 1844 }
3687d221 1845 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1846
50526e47 1847 sfree(vstring);
50526e47 1848
8df7a775 1849 crFinish(0);
1850}
1851
1852static void ssh_gotdata(unsigned char *data, int datalen)
1853{
1854 crBegin;
1855
1856 /*
1857 * To begin with, feed the characters one by one to the
1858 * protocol initialisation / selection function do_ssh_init().
1859 * When that returns 0, we're done with the initial greeting
1860 * exchange and can move on to packet discipline.
1861 */
1862 while (1) {
1863 int ret;
1864 if (datalen == 0)
1865 crReturnV; /* more data please */
1866 ret = do_ssh_init(*data);
32874aea 1867 data++;
1868 datalen--;
8df7a775 1869 if (ret == 0)
1870 break;
1871 }
1872
1873 /*
1874 * We emerge from that loop when the initial negotiation is
1875 * over and we have selected an s_rdpkt function. Now pass
1876 * everything to s_rdpkt, and then pass the resulting packets
1877 * to the proper protocol handler.
1878 */
1879 if (datalen == 0)
1880 crReturnV;
1881 while (1) {
1882 while (datalen > 0) {
32874aea 1883 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1884 if (ssh_state == SSH_STATE_CLOSED) {
1885 return;
1886 }
8df7a775 1887 ssh_protocol(NULL, 0, 1);
1888 if (ssh_state == SSH_STATE_CLOSED) {
1889 return;
1890 }
1891 }
1892 }
1893 crReturnV;
1894 }
1895 crFinishV;
1896}
1897
32874aea 1898static int ssh_closing(Plug plug, char *error_msg, int error_code,
1899 int calling_back)
1900{
7e78000d 1901 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1902 if (s) {
1903 sk_close(s);
1904 s = NULL;
1905 }
7e78000d 1906 if (error_msg) {
32874aea 1907 /* A socket error has occurred. */
247308b5 1908 logevent(error_msg);
32874aea 1909 connection_fatal(error_msg);
7e78000d 1910 } else {
1911 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1912 }
7e78000d 1913 return 0;
1914}
1915
32874aea 1916static int ssh_receive(Plug plug, int urgent, char *data, int len)
1917{
1918 ssh_gotdata(data, len);
3257deae 1919 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1920 if (s) {
1921 sk_close(s);
1922 s = NULL;
1923 }
1924 return 0;
3257deae 1925 }
fef97f43 1926 return 1;
374330e2 1927}
1928
5471d09a 1929static void ssh_sent(Plug plug, int bufsize)
1930{
1931 /*
1932 * If the send backlog on the SSH socket itself clears, we
1933 * should unthrottle the whole world if it was throttled.
1934 */
1935 if (bufsize < SSH_MAX_BACKLOG)
1936 ssh_throttle_all(0, bufsize);
1937}
1938
fb09bf1c 1939/*
8df7a775 1940 * Connect to specified host and port.
1941 * Returns an error message, or NULL on success.
6e1ebb76 1942 * Also places the canonical host name into `realhost'. It must be
1943 * freed by the caller.
8df7a775 1944 */
2184a5d9 1945static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
8df7a775 1946{
7e78000d 1947 static struct plug_function_table fn_table = {
1948 ssh_closing,
5471d09a 1949 ssh_receive,
1950 ssh_sent,
1951 NULL
7e78000d 1952 }, *fn_table_ptr = &fn_table;
1953
8df7a775 1954 SockAddr addr;
1955 char *err;
1956#ifdef FWHACK
1957 char *FWhost;
1958 int FWport;
1959#endif
1960
32874aea 1961 savedhost = smalloc(1 + strlen(host));
8df7a775 1962 if (!savedhost)
1963 fatalbox("Out of memory");
1964 strcpy(savedhost, host);
1965
1966 if (port < 0)
1967 port = 22; /* default ssh port */
1968 savedport = port;
1969
1970#ifdef FWHACK
1971 FWhost = host;
1972 FWport = port;
1973 host = FWSTR;
1974 port = 23;
1975#endif
1976
1977 /*
1978 * Try to find host.
1979 */
3ad9d396 1980 {
1981 char buf[200];
1982 sprintf(buf, "Looking up host \"%.170s\"", host);
1983 logevent(buf);
1984 }
8df7a775 1985 addr = sk_namelookup(host, realhost);
32874aea 1986 if ((err = sk_addr_error(addr)))
8df7a775 1987 return err;
1988
1989#ifdef FWHACK
6e1ebb76 1990 *realhost = strdup(FWhost);
8df7a775 1991#endif
1992
1993 /*
1994 * Open socket.
1995 */
3ad9d396 1996 {
1997 char buf[200], addrbuf[100];
1998 sk_getaddr(addr, addrbuf, 100);
1999 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2000 logevent(buf);
2001 }
8eebd221 2002 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
67c4ba2e 2003 if ((err = sk_socket_error(s))) {
2004 s = NULL;
8df7a775 2005 return err;
67c4ba2e 2006 }
8df7a775 2007
2008#ifdef FWHACK
2009 sk_write(s, "connect ", 8);
2010 sk_write(s, FWhost, strlen(FWhost));
2011 {
2012 char buf[20];
2013 sprintf(buf, " %d\n", FWport);
2014 sk_write(s, buf, strlen(buf));
2015 }
2016#endif
2017
2018 return NULL;
2019}
2020
2021/*
5471d09a 2022 * Throttle or unthrottle the SSH connection.
2023 */
2024static void ssh1_throttle(int adjust)
2025{
2026 int old_count = ssh1_throttle_count;
2027 ssh1_throttle_count += adjust;
2028 assert(ssh1_throttle_count >= 0);
2029 if (ssh1_throttle_count && !old_count) {
2030 sk_set_frozen(s, 1);
2031 } else if (!ssh1_throttle_count && old_count) {
2032 sk_set_frozen(s, 0);
2033 }
2034}
2035
2036/*
2037 * Throttle or unthrottle _all_ local data streams (for when sends
2038 * on the SSH connection itself back up).
2039 */
2040static void ssh_throttle_all(int enable, int bufsize)
2041{
2042 int i;
2043 struct ssh_channel *c;
2044
2045 if (enable == ssh_throttled_all)
2046 return;
2047 ssh_throttled_all = enable;
2048 ssh_overall_bufsize = bufsize;
2049 if (!ssh_channels)
2050 return;
2051 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2052 switch (c->type) {
2053 case CHAN_MAINSESSION:
2054 /*
2055 * This is treated separately, outside the switch.
2056 */
2057 break;
2058 case CHAN_X11:
2059 x11_override_throttle(c->u.x11.s, enable);
2060 break;
2061 case CHAN_AGENT:
2062 /* Agent channels require no buffer management. */
2063 break;
2064 case CHAN_SOCKDATA:
2065 pfd_override_throttle(c->u.x11.s, enable);
2066 break;
2067 }
2068 }
2069}
2070
2071/*
0405e71f 2072 * Username and password input, abstracted off into reusable
2073 * routines (hopefully even reusable between SSH1 and SSH2!).
2074 */
2075static char *ssh_userpass_input_buffer;
2076static int ssh_userpass_input_buflen;
2077static int ssh_userpass_input_bufpos;
2078static int ssh_userpass_input_echo;
2079
2080/* Set up a username or password input loop on a given buffer. */
2081void setup_userpass_input(char *buffer, int buflen, int echo)
2082{
2083 ssh_userpass_input_buffer = buffer;
2084 ssh_userpass_input_buflen = buflen;
2085 ssh_userpass_input_bufpos = 0;
2086 ssh_userpass_input_echo = echo;
2087}
2088
2089/*
2090 * Process some terminal data in the course of username/password
2091 * input. Returns >0 for success (line of input returned in
2092 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2093 * for inconclusive (keep waiting for more input please).
2094 */
2095int process_userpass_input(unsigned char *in, int inlen)
2096{
2097 char c;
2098
2099 while (inlen--) {
2100 switch (c = *in++) {
2101 case 10:
2102 case 13:
2103 ssh_userpass_input_buffer[ssh_userpass_input_bufpos] = 0;
2104 ssh_userpass_input_buffer[ssh_userpass_input_buflen-1] = 0;
2105 return +1;
2106 break;
2107 case 8:
2108 case 127:
2109 if (ssh_userpass_input_bufpos > 0) {
2110 if (ssh_userpass_input_echo)
2111 c_write_str("\b \b");
2112 ssh_userpass_input_bufpos--;
2113 }
2114 break;
2115 case 21:
2116 case 27:
2117 while (ssh_userpass_input_bufpos > 0) {
2118 if (ssh_userpass_input_echo)
2119 c_write_str("\b \b");
2120 ssh_userpass_input_bufpos--;
2121 }
2122 break;
2123 case 3:
2124 case 4:
2125 return -1;
2126 break;
2127 default:
2128 if (((c >= ' ' && c <= '~') ||
2129 ((unsigned char) c >= 160))
2130 && ssh_userpass_input_bufpos < ssh_userpass_input_buflen-1) {
2131 ssh_userpass_input_buffer[ssh_userpass_input_bufpos++] = c;
2132 if (ssh_userpass_input_echo)
2133 c_write(&c, 1);
2134 }
2135 break;
2136 }
2137 }
2138 return 0;
2139}
2140
2141/*
fb09bf1c 2142 * Handle the key exchange and user authentication phases.
2143 */
e5574168 2144static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 2145{
2d466ffd 2146 int i, j;
2147 static int len;
2148 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 2149 unsigned char cookie[8];
2150 struct RSAKey servkey, hostkey;
2151 struct MD5Context md5c;
ccbfb941 2152 static unsigned long supported_ciphers_mask, supported_auths_mask;
67b59fbb 2153 static int tried_publickey, tried_agent;
614a20a0 2154 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 2155 static unsigned char session_id[16];
2d466ffd 2156 static int cipher_type;
b585ec46 2157 static char username[100];
396778f1 2158 static void *publickey_blob;
2159 int publickey_bloblen;
374330e2 2160
374330e2 2161 crBegin;
2162
32874aea 2163 if (!ispkt)
2164 crWaitUntil(ispkt);
374330e2 2165
8d5de777 2166 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2167 bombout(("Public key packet not received"));
32874aea 2168 crReturn(0);
8d5de777 2169 }
374330e2 2170
c5e9c988 2171 logevent("Received public keys");
374330e2 2172
c5e9c988 2173 memcpy(cookie, pktin.body, 8);
374330e2 2174
32874aea 2175 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2176 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 2177
c5e9c988 2178 /*
1c2a93c4 2179 * Log the host key fingerprint.
c5e9c988 2180 */
c5e9c988 2181 {
2182 char logmsg[80];
1c2a93c4 2183 logevent("Host key fingerprint is:");
c5e9c988 2184 strcpy(logmsg, " ");
32874aea 2185 hostkey.comment = NULL;
2186 rsa_fingerprint(logmsg + strlen(logmsg),
2187 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2188 logevent(logmsg);
2189 }
2190
32874aea 2191 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2192 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2193 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 2194
32874aea 2195 ssh1_local_protoflags =
2196 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 2197 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2198
c5e9c988 2199 MD5Init(&md5c);
374330e2 2200 MD5Update(&md5c, keystr2, hostkey.bytes);
2201 MD5Update(&md5c, keystr1, servkey.bytes);
2202 MD5Update(&md5c, pktin.body, 8);
374330e2 2203 MD5Final(session_id, &md5c);
2204
32874aea 2205 for (i = 0; i < 32; i++)
374330e2 2206 session_key[i] = random_byte();
2207
2208 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2209
dcbde236 2210 rsabuf = smalloc(len);
374330e2 2211 if (!rsabuf)
2212 fatalbox("Out of memory");
2213
89ee5268 2214 /*
2215 * Verify the host key.
2216 */
2217 {
32874aea 2218 /*
2219 * First format the key into a string.
2220 */
2221 int len = rsastr_len(&hostkey);
2222 char fingerprint[100];
2223 char *keystr = smalloc(len);
2224 if (!keystr)
2225 fatalbox("Out of memory");
2226 rsastr_fmt(keystr, &hostkey);
2227 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2228 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2229 fingerprint);
2230 sfree(keystr);
2231 }
2232
2233 for (i = 0; i < 32; i++) {
374330e2 2234 rsabuf[i] = session_key[i];
2235 if (i < 16)
2236 rsabuf[i] ^= session_id[i];
2237 }
2238
2239 if (hostkey.bytes > servkey.bytes) {
2240 rsaencrypt(rsabuf, 32, &servkey);
2241 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2242 } else {
2243 rsaencrypt(rsabuf, 32, &hostkey);
2244 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2245 }
2246
c5e9c988 2247 logevent("Encrypted session key");
2248
ca20bfcf 2249 {
2250 int cipher_chosen = 0, warn = 0;
2251 char *cipher_string = NULL;
2252 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2253 int next_cipher = cfg.ssh_cipherlist[i];
2254 if (next_cipher == CIPHER_WARN) {
2255 /* If/when we choose a cipher, warn about it */
2256 warn = 1;
2257 } else if (next_cipher == CIPHER_AES) {
2258 /* XXX Probably don't need to mention this. */
2259 logevent("AES not supported in SSH1, skipping");
2260 } else {
2261 switch (next_cipher) {
2262 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2263 cipher_string = "3DES"; break;
2264 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2265 cipher_string = "Blowfish"; break;
2266 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2267 cipher_string = "single-DES"; break;
2268 }
2269 if (supported_ciphers_mask & (1 << cipher_type))
2270 cipher_chosen = 1;
2271 }
2272 }
2273 if (!cipher_chosen) {
2274 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2275 bombout(("Server violates SSH 1 protocol by not "
2276 "supporting 3DES encryption"));
2277 else
2278 /* shouldn't happen */
2279 bombout(("No supported ciphers found"));
a99a05c0 2280 crReturn(0);
2281 }
ca20bfcf 2282
2283 /* Warn about chosen cipher if necessary. */
2284 if (warn)
2285 askcipher(cipher_string, 0);
bea1ef5f 2286 }
ca20bfcf 2287
c5e9c988 2288 switch (cipher_type) {
32874aea 2289 case SSH_CIPHER_3DES:
2290 logevent("Using 3DES encryption");
2291 break;
2292 case SSH_CIPHER_DES:
2293 logevent("Using single-DES encryption");
2294 break;
2295 case SSH_CIPHER_BLOWFISH:
2296 logevent("Using Blowfish encryption");
2297 break;
c5e9c988 2298 }
bea1ef5f 2299
e5574168 2300 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 2301 PKT_CHAR, cipher_type,
2302 PKT_DATA, cookie, 8,
2303 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2304 PKT_DATA, rsabuf, len,
2305 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 2306
c5e9c988 2307 logevent("Trying to enable encryption...");
374330e2 2308
dcbde236 2309 sfree(rsabuf);
374330e2 2310
5e8358ad 2311 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 2312 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 2313 cipher->sesskey(session_key);
2314
fb09bf1c 2315 crWaitUntil(ispkt);
374330e2 2316
8d5de777 2317 if (pktin.type != SSH1_SMSG_SUCCESS) {
2318 bombout(("Encryption not successfully enabled"));
32874aea 2319 crReturn(0);
8d5de777 2320 }
374330e2 2321
c5e9c988 2322 logevent("Successfully started encryption");
2323
374330e2 2324 fflush(stdout);
2325 {
67779be7 2326 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2327 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2328 if (!ssh_get_line("login as: ",
2329 username, sizeof(username), FALSE)) {
2330 /*
2331 * get_line failed to get a username.
2332 * Terminate.
2333 */
2334 logevent("No username provided. Abandoning session.");
2335 ssh_state = SSH_STATE_CLOSED;
2336 crReturn(1);
2337 }
2338 } else {
0405e71f 2339 static int ret;
32874aea 2340 c_write_str("login as: ");
2341 ssh_send_ok = 1;
0405e71f 2342
2343 setup_userpass_input(username, sizeof(username), 1);
2344 do {
32874aea 2345 crWaitUntil(!ispkt);
0405e71f 2346 ret = process_userpass_input(in, inlen);
2347 } while (ret == 0);
2348 if (ret < 0)
2349 cleanup_exit(0);
32874aea 2350 c_write_str("\r\n");
32874aea 2351 }
2352 } else {
374330e2 2353 strncpy(username, cfg.username, 99);
2354 username[99] = '\0';
374330e2 2355 }
fb09bf1c 2356
e5574168 2357 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2358 {
32874aea 2359 char userlog[22 + sizeof(username)];
c5e9c988 2360 sprintf(userlog, "Sent username \"%s\"", username);
2361 logevent(userlog);
32874aea 2362 if (flags & FLAG_INTERACTIVE &&
2363 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2364 strcat(userlog, "\r\n");
32874aea 2365 c_write_str(userlog);
3c8e959b 2366 }
c5e9c988 2367 }
374330e2 2368 }
2369
fb09bf1c 2370 crWaitUntil(ispkt);
374330e2 2371
0df73905 2372 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2373 /* We must not attempt PK auth. Pretend we've already tried it. */
2374 tried_publickey = tried_agent = 1;
2375 } else {
2376 tried_publickey = tried_agent = 0;
2377 }
614a20a0 2378 tis_auth_refused = ccard_auth_refused = 0;
396778f1 2379 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2380 if (*cfg.keyfile) {
2381 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2382 publickey_blob = NULL;
2383 } else
2384 publickey_blob = NULL;
7cca0d81 2385
e5574168 2386 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2387 static char password[100];
a52f067e 2388 static char prompt[200];
374330e2 2389 static int pos;
2390 static char c;
32874aea 2391 static int pwpkt_type;
32874aea 2392 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2393
67b59fbb 2394 if (agent_exists() && !tried_agent) {
32874aea 2395 /*
2396 * Attempt RSA authentication using Pageant.
2397 */
2398 static unsigned char request[5], *response, *p;
2399 static int responselen;
2400 static int i, nkeys;
2401 static int authed = FALSE;
2402 void *r;
2403
67b59fbb 2404 tried_agent = 1;
32874aea 2405 logevent("Pageant is running. Requesting keys.");
2406
2407 /* Request the keys held by the agent. */
2408 PUT_32BIT(request, 1);
2409 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2410 agent_query(request, 5, &r, &responselen);
2411 response = (unsigned char *) r;
2412 if (response && responselen >= 5 &&
2413 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2414 p = response + 5;
2415 nkeys = GET_32BIT(p);
2416 p += 4;
2417 {
2418 char buf[64];
2419 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2420 logevent(buf);
2421 }
2422 for (i = 0; i < nkeys; i++) {
2423 static struct RSAKey key;
2424 static Bignum challenge;
2425 static char *commentp;
2426 static int commentlen;
2427
2428 {
2429 char buf[64];
2430 sprintf(buf, "Trying Pageant key #%d", i);
2431 logevent(buf);
2432 }
396778f1 2433 if (publickey_blob &&
2434 !memcmp(p, publickey_blob, publickey_bloblen)) {
2435 logevent("This key matches configured key file");
2436 tried_publickey = 1;
2437 }
32874aea 2438 p += 4;
2439 p += ssh1_read_bignum(p, &key.exponent);
2440 p += ssh1_read_bignum(p, &key.modulus);
2441 commentlen = GET_32BIT(p);
2442 p += 4;
2443 commentp = p;
2444 p += commentlen;
2445 send_packet(SSH1_CMSG_AUTH_RSA,
2446 PKT_BIGNUM, key.modulus, PKT_END);
2447 crWaitUntil(ispkt);
2448 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2449 logevent("Key refused");
2450 continue;
2451 }
2452 logevent("Received RSA challenge");
2453 ssh1_read_bignum(pktin.body, &challenge);
2454 {
2455 char *agentreq, *q, *ret;
2d466ffd 2456 void *vret;
32874aea 2457 int len, retlen;
2458 len = 1 + 4; /* message type, bit count */
2459 len += ssh1_bignum_length(key.exponent);
2460 len += ssh1_bignum_length(key.modulus);
2461 len += ssh1_bignum_length(challenge);
2462 len += 16; /* session id */
2463 len += 4; /* response format */
2464 agentreq = smalloc(4 + len);
2465 PUT_32BIT(agentreq, len);
2466 q = agentreq + 4;
2467 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2468 PUT_32BIT(q, bignum_bitcount(key.modulus));
2469 q += 4;
2470 q += ssh1_write_bignum(q, key.exponent);
2471 q += ssh1_write_bignum(q, key.modulus);
2472 q += ssh1_write_bignum(q, challenge);
2473 memcpy(q, session_id, 16);
2474 q += 16;
2475 PUT_32BIT(q, 1); /* response format */
2d466ffd 2476 agent_query(agentreq, len + 4, &vret, &retlen);
2477 ret = vret;
32874aea 2478 sfree(agentreq);
2479 if (ret) {
2480 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2481 logevent("Sending Pageant's response");
2482 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2483 PKT_DATA, ret + 5, 16,
2484 PKT_END);
2485 sfree(ret);
2486 crWaitUntil(ispkt);
2487 if (pktin.type == SSH1_SMSG_SUCCESS) {
2488 logevent
2489 ("Pageant's response accepted");
2490 if (flags & FLAG_VERBOSE) {
2491 c_write_str
2492 ("Authenticated using RSA key \"");
2493 c_write(commentp, commentlen);
2494 c_write_str("\" from agent\r\n");
2495 }
2496 authed = TRUE;
2497 } else
2498 logevent
2499 ("Pageant's response not accepted");
2500 } else {
2501 logevent
2502 ("Pageant failed to answer challenge");
2503 sfree(ret);
2504 }
2505 } else {
2506 logevent("No reply received from Pageant");
2507 }
2508 }
2509 freebn(key.exponent);
2510 freebn(key.modulus);
2511 freebn(challenge);
2512 if (authed)
2513 break;
2514 }
2515 }
2516 if (authed)
2517 break;
2518 }
2519 if (*cfg.keyfile && !tried_publickey)
2520 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2521
614a20a0 2522 if (cfg.try_tis_auth &&
2523 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2524 !tis_auth_refused) {
32874aea 2525 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2526 logevent("Requested TIS authentication");
2527 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2528 crWaitUntil(ispkt);
2529 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2530 logevent("TIS authentication declined");
2531 if (flags & FLAG_INTERACTIVE)
2532 c_write_str("TIS authentication refused.\r\n");
614a20a0 2533 tis_auth_refused = 1;
2534 continue;
32874aea 2535 } else {
2536 int challengelen = ((pktin.body[0] << 24) |
2537 (pktin.body[1] << 16) |
2538 (pktin.body[2] << 8) |
2539 (pktin.body[3]));
2540 logevent("Received TIS challenge");
2541 if (challengelen > sizeof(prompt) - 1)
2542 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2543 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2544 /* Prompt heuristic comes from OpenSSH */
2545 strncpy(prompt + challengelen,
2546 memchr(prompt, '\n', challengelen) ?
2547 "": "\r\nResponse: ",
2548 (sizeof prompt) - challengelen);
2549 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2550 }
2551 }
614a20a0 2552 if (cfg.try_tis_auth &&
2553 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2554 !ccard_auth_refused) {
32874aea 2555 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2556 logevent("Requested CryptoCard authentication");
2557 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2558 crWaitUntil(ispkt);
2559 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2560 logevent("CryptoCard authentication declined");
2561 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2562 ccard_auth_refused = 1;
2563 continue;
32874aea 2564 } else {
2565 int challengelen = ((pktin.body[0] << 24) |
2566 (pktin.body[1] << 16) |
2567 (pktin.body[2] << 8) |
2568 (pktin.body[3]));
2569 logevent("Received CryptoCard challenge");
2570 if (challengelen > sizeof(prompt) - 1)
2571 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2572 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2573 strncpy(prompt + challengelen,
2574 memchr(prompt, '\n', challengelen) ?
2575 "" : "\r\nResponse: ",
32874aea 2576 sizeof(prompt) - challengelen);
2577 prompt[sizeof(prompt) - 1] = '\0';
2578 }
2579 }
2580 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2581 sprintf(prompt, "%.90s@%.90s's password: ",
2582 username, savedhost);
2583 }
2584 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2585 char *comment = NULL;
231ee168 2586 int type;
2587 char msgbuf[256];
32874aea 2588 if (flags & FLAG_VERBOSE)
2589 c_write_str("Trying public key authentication.\r\n");
231ee168 2590 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2591 logevent(msgbuf);
2592 type = key_type(cfg.keyfile);
2593 if (type != SSH_KEYTYPE_SSH1) {
2594 sprintf(msgbuf, "Key is of wrong type (%s)",
2595 key_type_to_str(type));
2596 logevent(msgbuf);
2597 c_write_str(msgbuf);
2598 c_write_str("\r\n");
2599 tried_publickey = 1;
2600 continue;
2601 }
32874aea 2602 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2603 if (flags & FLAG_VERBOSE)
2604 c_write_str("No passphrase required.\r\n");
2605 goto tryauth;
2606 }
2607 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2608 sfree(comment);
2609 }
a52f067e 2610
614a20a0 2611 /*
2612 * Show password prompt, having first obtained it via a TIS
2613 * or CryptoCard exchange if we're doing TIS or CryptoCard
2614 * authentication.
2615 */
fa17a66e 2616 if (ssh_get_line) {
2617 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2618 /*
2619 * get_line failed to get a password (for example
2620 * because one was supplied on the command line
2621 * which has already failed to work). Terminate.
2622 */
2bc6a386 2623 send_packet(SSH1_MSG_DISCONNECT,
2624 PKT_STR, "No more passwords available to try",
2625 PKT_END);
247308b5 2626 logevent("Unable to authenticate");
2bc6a386 2627 connection_fatal("Unable to authenticate");
32874aea 2628 ssh_state = SSH_STATE_CLOSED;
2629 crReturn(1);
2630 }
fb09bf1c 2631 } else {
614a20a0 2632 /* Prompt may have come from server. We've munged it a bit, so
2633 * we know it to be zero-terminated at least once. */
0405e71f 2634 static int ret;
614a20a0 2635 c_write_untrusted(prompt, strlen(prompt));
32874aea 2636 pos = 0;
0405e71f 2637
2638 setup_userpass_input(password, sizeof(password), 0);
2639 do {
32874aea 2640 crWaitUntil(!ispkt);
0405e71f 2641 ret = process_userpass_input(in, inlen);
2642 } while (ret == 0);
2643 if (ret < 0)
2644 cleanup_exit(0);
32874aea 2645 c_write_str("\r\n");
2646 }
2647
2648 tryauth:
7cca0d81 2649 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2650 /*
2651 * Try public key authentication with the specified
2652 * key file.
2653 */
2654 static struct RSAKey pubkey;
2655 static Bignum challenge, response;
2656 static int i;
2657 static unsigned char buffer[32];
2658
2659 tried_publickey = 1;
2660 i = loadrsakey(cfg.keyfile, &pubkey, password);
2661 if (i == 0) {
7963af2f 2662 c_write_str("Couldn't load private key from ");
32874aea 2663 c_write_str(cfg.keyfile);
2664 c_write_str(".\r\n");
2665 continue; /* go and try password */
2666 }
2667 if (i == -1) {
2668 c_write_str("Wrong passphrase.\r\n");
2669 tried_publickey = 0;
2670 continue; /* try again */
2671 }
2672
2673 /*
2674 * Send a public key attempt.
2675 */
2676 send_packet(SSH1_CMSG_AUTH_RSA,
2677 PKT_BIGNUM, pubkey.modulus, PKT_END);
2678
2679 crWaitUntil(ispkt);
2680 if (pktin.type == SSH1_SMSG_FAILURE) {
2681 c_write_str("Server refused our public key.\r\n");
2682 continue; /* go and try password */
2683 }
2684 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2685 bombout(("Bizarre response to offer of public key"));
2686 crReturn(0);
2687 }
2688 ssh1_read_bignum(pktin.body, &challenge);
2689 response = rsadecrypt(challenge, &pubkey);
2690 freebn(pubkey.private_exponent); /* burn the evidence */
2691
2692 for (i = 0; i < 32; i++) {
2693 buffer[i] = bignum_byte(response, 31 - i);
2694 }
2695
2696 MD5Init(&md5c);
2697 MD5Update(&md5c, buffer, 32);
2698 MD5Update(&md5c, session_id, 16);
2699 MD5Final(buffer, &md5c);
2700
2701 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2702 PKT_DATA, buffer, 16, PKT_END);
2703
2704 crWaitUntil(ispkt);
2705 if (pktin.type == SSH1_SMSG_FAILURE) {
2706 if (flags & FLAG_VERBOSE)
2707 c_write_str
2708 ("Failed to authenticate with our public key.\r\n");
2709 continue; /* go and try password */
2710 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2711 bombout(
2712 ("Bizarre response to RSA authentication response"));
2713 crReturn(0);
2714 }
2715
2716 break; /* we're through! */
2717 } else {
2718 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2719 /*
2720 * Defence against traffic analysis: we send a
2721 * whole bunch of packets containing strings of
2722 * different lengths. One of these strings is the
2723 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2724 * The others are all random data in
2725 * SSH1_MSG_IGNORE packets. This way a passive
2726 * listener can't tell which is the password, and
2727 * hence can't deduce the password length.
2728 *
2729 * Anybody with a password length greater than 16
2730 * bytes is going to have enough entropy in their
2731 * password that a listener won't find it _that_
2732 * much help to know how long it is. So what we'll
2733 * do is:
2734 *
2735 * - if password length < 16, we send 15 packets
2736 * containing string lengths 1 through 15
2737 *
2738 * - otherwise, we let N be the nearest multiple
2739 * of 8 below the password length, and send 8
2740 * packets containing string lengths N through
2741 * N+7. This won't obscure the order of
2742 * magnitude of the password length, but it will
2743 * introduce a bit of extra uncertainty.
2744 *
2745 * A few servers (the old 1.2.18 through 1.2.22)
2746 * can't deal with SSH1_MSG_IGNORE. For these
2747 * servers, we need an alternative defence. We make
2748 * use of the fact that the password is interpreted
2749 * as a C string: so we can append a NUL, then some
2750 * random data.
bd358db1 2751 *
2752 * One server (a Cisco one) can deal with neither
2753 * SSH1_MSG_IGNORE _nor_ a padded password string.
2754 * For this server we are left with no defences
2755 * against password length sniffing.
32874aea 2756 */
bd358db1 2757 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2758 /*
2759 * The server can deal with SSH1_MSG_IGNORE, so
2760 * we can use the primary defence.
2761 */
32874aea 2762 int bottom, top, pwlen, i;
2763 char *randomstr;
2764
2765 pwlen = strlen(password);
2766 if (pwlen < 16) {
2767 bottom = 0; /* zero length passwords are OK! :-) */
2768 top = 15;
2769 } else {
2770 bottom = pwlen & ~7;
2771 top = bottom + 7;
2772 }
2773
2774 assert(pwlen >= bottom && pwlen <= top);
2775
2776 randomstr = smalloc(top + 1);
2777
2778 for (i = bottom; i <= top; i++) {
2779 if (i == pwlen)
2780 defer_packet(pwpkt_type, PKT_STR, password,
2781 PKT_END);
2782 else {
2783 for (j = 0; j < i; j++) {
2784 do {
2785 randomstr[j] = random_byte();
2786 } while (randomstr[j] == '\0');
2787 }
2788 randomstr[i] = '\0';
2789 defer_packet(SSH1_MSG_IGNORE,
2790 PKT_STR, randomstr, PKT_END);
2791 }
2792 }
bd358db1 2793 logevent("Sending password with camouflage packets");
32874aea 2794 ssh_pkt_defersend();
bd358db1 2795 }
2796 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2797 /*
2798 * The server can't deal with SSH1_MSG_IGNORE
2799 * but can deal with padded passwords, so we
2800 * can use the secondary defence.
2801 */
bd358db1 2802 char string[64];
2803 char *s;
2804 int len;
2805
2806 len = strlen(password);
2807 if (len < sizeof(string)) {
2808 s = string;
2809 strcpy(string, password);
2810 len++; /* cover the zero byte */
2811 while (len < sizeof(string)) {
2812 string[len++] = (char) random_byte();
2813 }
2814 } else {
2815 s = password;
2816 }
2817 logevent("Sending length-padded password");
2818 send_packet(pwpkt_type, PKT_INT, len,
2819 PKT_DATA, s, len, PKT_END);
2820 } else {
2821 /*
2822 * The server has _both_
2823 * BUG_CHOKES_ON_SSH1_IGNORE and
2824 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2825 * therefore nothing we can do.
2826 */
2827 int len;
2828 len = strlen(password);
2829 logevent("Sending unpadded password");
2830 send_packet(pwpkt_type, PKT_INT, len,
2831 PKT_DATA, password, len, PKT_END);
32874aea 2832 }
2833 } else {
2834 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2835 }
2836 }
c5e9c988 2837 logevent("Sent password");
374330e2 2838 memset(password, 0, strlen(password));
fb09bf1c 2839 crWaitUntil(ispkt);
e5574168 2840 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2841 if (flags & FLAG_VERBOSE)
2842 c_write_str("Access denied\r\n");
c5e9c988 2843 logevent("Authentication refused");
e5574168 2844 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2845 logevent("Received disconnect request");
32874aea 2846 ssh_state = SSH_STATE_CLOSED;
85ee8208 2847 crReturn(1);
e5574168 2848 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2849 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2850 crReturn(0);
374330e2 2851 }
2852 }
2853
c5e9c988 2854 logevent("Authentication successful");
2855
fb09bf1c 2856 crFinish(1);
2857}
2858
32874aea 2859void sshfwd_close(struct ssh_channel *c)
2860{
80e48603 2861 if (c && !c->closes) {
4ed34d25 2862 /*
2863 * If the channel's remoteid is -1, we have sent
2864 * CHANNEL_OPEN for this channel, but it hasn't even been
2865 * acknowledged by the server. So we must set a close flag
2866 * on it now, and then when the server acks the channel
2867 * open, we can close it then.
2868 */
36cac739 2869 if (((int)c->remoteid) != -1) {
4ed34d25 2870 if (ssh_version == 1) {
2871 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2872 PKT_END);
2873 } else {
2874 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2875 ssh2_pkt_adduint32(c->remoteid);
2876 ssh2_pkt_send();
2877 }
32874aea 2878 }
2879 c->closes = 1;
2880 if (c->type == CHAN_X11) {
2881 c->u.x11.s = NULL;
d74d141c 2882 logevent("Forwarded X11 connection terminated");
4ed34d25 2883 } else if (c->type == CHAN_SOCKDATA ||
2884 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2885 c->u.pfd.s = NULL;
2886 logevent("Forwarded port closed");
32874aea 2887 }
2888 }
2889}
2890
5471d09a 2891int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2892{
783415f8 2893 if (ssh_version == 1) {
32874aea 2894 send_packet(SSH1_MSG_CHANNEL_DATA,
2895 PKT_INT, c->remoteid,
2896 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2897 /*
2898 * In SSH1 we can return 0 here - implying that forwarded
2899 * connections are never individually throttled - because
2900 * the only circumstance that can cause throttling will be
2901 * the whole SSH connection backing up, in which case
2902 * _everything_ will be throttled as a whole.
2903 */
2904 return 0;
783415f8 2905 } else {
32874aea 2906 ssh2_add_channel_data(c, buf, len);
5471d09a 2907 return ssh2_try_send(c);
2908 }
2909}
2910
2911void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2912{
2913 if (ssh_version == 1) {
2914 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2915 c->v.v1.throttling = 0;
2916 ssh1_throttle(-1);
2917 }
2918 } else {
2919 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2920 }
9c964e85 2921}
2922
32874aea 2923static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2924{
fb09bf1c 2925 crBegin;
2926
2927 random_init();
2928
e5574168 2929 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2930 crReturnV;
85ee8208 2931 }
2932 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2933 crReturnV;
fb09bf1c 2934
979310f1 2935 if (cfg.agentfwd && agent_exists()) {
32874aea 2936 logevent("Requesting agent forwarding");
2937 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2938 do {
2939 crReturnV;
2940 } while (!ispkt);
2941 if (pktin.type != SSH1_SMSG_SUCCESS
2942 && pktin.type != SSH1_SMSG_FAILURE) {
2943 bombout(("Protocol confusion"));
2944 crReturnV;
2945 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2946 logevent("Agent forwarding refused");
2947 } else {
2948 logevent("Agent forwarding enabled");
db7d555c 2949 ssh_agentfwd_enabled = TRUE;
2950 }
dacbd0e8 2951 }
2952
9c964e85 2953 if (cfg.x11_forward) {
32874aea 2954 char proto[20], data[64];
2955 logevent("Requesting X11 forwarding");
2956 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2957 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2958 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2959 PKT_STR, proto, PKT_STR, data,
2960 PKT_INT, 0, PKT_END);
2961 } else {
2962 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2963 PKT_STR, proto, PKT_STR, data, PKT_END);
2964 }
2965 do {
2966 crReturnV;
2967 } while (!ispkt);
2968 if (pktin.type != SSH1_SMSG_SUCCESS
2969 && pktin.type != SSH1_SMSG_FAILURE) {
2970 bombout(("Protocol confusion"));
2971 crReturnV;
2972 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2973 logevent("X11 forwarding refused");
2974 } else {
2975 logevent("X11 forwarding enabled");
9c964e85 2976 ssh_X11_fwd_enabled = TRUE;
2977 }
2978 }
2979
d74d141c 2980 {
9bf696b1 2981 char type;
2982 static char *e;
d74d141c 2983 int n;
a4fc0d74 2984 int sport,dport,sserv,dserv;
d74d141c 2985 char sports[256], dports[256], host[256];
2986 char buf[1024];
a4fc0d74 2987 struct servent *se;
d74d141c 2988
bc240b21 2989 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 2990 /* Add port forwardings. */
2991 e = cfg.portfwd;
2992 while (*e) {
2993 type = *e++;
2994 n = 0;
2995 while (*e && *e != '\t')
2996 sports[n++] = *e++;
2997 sports[n] = 0;
2998 if (*e == '\t')
2999 e++;
3000 n = 0;
3001 while (*e && *e != ':')
3002 host[n++] = *e++;
3003 host[n] = 0;
3004 if (*e == ':')
3005 e++;
3006 n = 0;
3007 while (*e)
3008 dports[n++] = *e++;
3009 dports[n] = 0;
3010 e++;
3011 dport = atoi(dports);
a4fc0d74 3012 dserv = 0;
3013 if (dport == 0) {
3014 dserv = 1;
3015 se = getservbyname(dports, NULL);
3016 if (se != NULL) {
3017 dport = ntohs(se->s_port);
3018 } else {
3019 sprintf(buf,
3020 "Service lookup failed for destination port \"%s\"",
3021 dports);
3022 logevent(buf);
3023 }
3024 }
d74d141c 3025 sport = atoi(sports);
a4fc0d74 3026 sserv = 0;
3027 if (sport == 0) {
3028 sserv = 1;
3029 se = getservbyname(sports, NULL);
3030 if (se != NULL) {
3031 sport = ntohs(se->s_port);
3032 } else {
3033 sprintf(buf,
3034 "Service lookup failed for source port \"%s\"",
3035 sports);
3036 logevent(buf);
3037 }
3038 }
d74d141c 3039 if (sport && dport) {
3040 if (type == 'L') {
3041 pfd_addforward(host, dport, sport);
a4fc0d74 3042 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3043 " %s:%.*s%.*s%d%.*s",
3044 sserv ? strlen(sports) : 0, sports,
3045 sserv, "(", sport, sserv, ")",
3046 host,
3047 dserv ? strlen(dports) : 0, dports,
3048 dserv, "(", dport, dserv, ")");
d74d141c 3049 logevent(buf);
3050 } else {
3051 struct ssh_rportfwd *pf;
3052 pf = smalloc(sizeof(*pf));
bc240b21 3053 strcpy(pf->dhost, host);
3054 pf->dport = dport;
d74d141c 3055 if (add234(ssh_rportfwds, pf) != pf) {
3056 sprintf(buf,
95bc8819 3057 "Duplicate remote port forwarding to %s:%d",
d74d141c 3058 host, dport);
3059 logevent(buf);
bc240b21 3060 sfree(pf);
d74d141c 3061 } else {
a4fc0d74 3062 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3063 " forward to %s:%.*s%.*s%d%.*s",
3064 sserv ? strlen(sports) : 0, sports,
3065 sserv, "(", sport, sserv, ")",
3066 host,
3067 dserv ? strlen(dports) : 0, dports,
3068 dserv, "(", dport, dserv, ")");
d74d141c 3069 logevent(buf);
3070 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3071 PKT_INT, sport,
3072 PKT_STR, host,
3073 PKT_INT, dport,
3074 PKT_END);
9bf696b1 3075 do {
3076 crReturnV;
3077 } while (!ispkt);
3078 if (pktin.type != SSH1_SMSG_SUCCESS
3079 && pktin.type != SSH1_SMSG_FAILURE) {
3080 bombout(("Protocol confusion"));
3081 crReturnV;
3082 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3083 c_write_str("Server refused port forwarding\r\n");
3084 ssh_editing = ssh_echoing = 1;
3085 }
3086 logevent("Remote port forwarding enabled");
d74d141c 3087 }
3088 }
3089 }
3090 }
3091 }
3092
fef97f43 3093 if (!cfg.nopty) {
e5574168 3094 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 3095 PKT_STR, cfg.termtype,
3096 PKT_INT, rows, PKT_INT, cols,
3097 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3098 ssh_state = SSH_STATE_INTERMED;
3099 do {
3100 crReturnV;
3101 } while (!ispkt);
3102 if (pktin.type != SSH1_SMSG_SUCCESS
3103 && pktin.type != SSH1_SMSG_FAILURE) {
3104 bombout(("Protocol confusion"));
3105 crReturnV;
3106 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3107 c_write_str("Server refused to allocate pty\r\n");
3108 ssh_editing = ssh_echoing = 1;
3109 }
c5e9c988 3110 logevent("Allocated pty");
0965bee0 3111 } else {
32874aea 3112 ssh_editing = ssh_echoing = 1;
374330e2 3113 }
3114
4ba9b64b 3115 if (cfg.compression) {
32874aea 3116 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3117 do {
3118 crReturnV;
3119 } while (!ispkt);
3120 if (pktin.type != SSH1_SMSG_SUCCESS
3121 && pktin.type != SSH1_SMSG_FAILURE) {
3122 bombout(("Protocol confusion"));
3123 crReturnV;
3124 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3125 c_write_str("Server refused to compress\r\n");
3126 }
4ba9b64b 3127 logevent("Started compression");
3128 ssh1_compressing = TRUE;
3129 zlib_compress_init();
3130 zlib_decompress_init();
3131 }
3132
fd5e5847 3133 /*
3134 * Start the shell or command.
3135 *
3136 * Special case: if the first-choice command is an SSH2
3137 * subsystem (hence not usable here) and the second choice
3138 * exists, we fall straight back to that.
3139 */
3140 {
3141 char *cmd = cfg.remote_cmd_ptr;
3142
3143 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3144 cmd = cfg.remote_cmd_ptr2;
3145 ssh_fallback_cmd = TRUE;
3146 }
3147 if (*cmd)
3148 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3149 else
3150 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3151 logevent("Started session");
3152 }
374330e2 3153
3154 ssh_state = SSH_STATE_SESSION;
3155 if (size_needed)
3156 ssh_size();
3687d221 3157 if (eof_needed)
32874aea 3158 ssh_special(TS_EOF);
374330e2 3159
760e88b2 3160 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 3161 ssh_send_ok = 1;
dacbd0e8 3162 ssh_channels = newtree234(ssh_channelcmp);
374330e2 3163 while (1) {
3164 crReturnV;
3165 if (ispkt) {
e5574168 3166 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 3167 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 3168 long len = GET_32BIT(pktin.body);
5471d09a 3169 int bufsize =
3170 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3171 pktin.body + 4, len);
90347b95 3172 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3173 ssh1_stdout_throttling = 1;
3174 ssh1_throttle(+1);
3175 }
e5574168 3176 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 3177 ssh_state = SSH_STATE_CLOSED;
c5e9c988 3178 logevent("Received disconnect request");
32874aea 3179 crReturnV;
3180 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3181 /* Remote side is trying to open a channel to talk to our
3182 * X-Server. Give them back a local channel number. */
3183 struct ssh_channel *c;
9c964e85 3184
3185 logevent("Received X11 connect request");
3186 /* Refuse if X11 forwarding is disabled. */
3187 if (!ssh_X11_fwd_enabled) {
3188 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3189 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 3190 logevent("Rejected X11 connect request");
3191 } else {
9c964e85 3192 c = smalloc(sizeof(struct ssh_channel));
3193
32874aea 3194 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3195 logevent("opening X11 forward connection failed");
3196 sfree(c);
3197 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3198 PKT_INT, GET_32BIT(pktin.body),
3199 PKT_END);
9c964e85 3200 } else {
32874aea 3201 logevent
3202 ("opening X11 forward connection succeeded");
3203 c->remoteid = GET_32BIT(pktin.body);
3204 c->localid = alloc_channel_id();
3205 c->closes = 0;
5471d09a 3206 c->v.v1.throttling = 0;
32874aea 3207 c->type = CHAN_X11; /* identify channel type */
3208 add234(ssh_channels, c);
3209 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3210 PKT_INT, c->remoteid, PKT_INT,
3211 c->localid, PKT_END);
3212 logevent("Opened X11 forward channel");
9c964e85 3213 }
3214 }
32874aea 3215 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3216 /* Remote side is trying to open a channel to talk to our
3217 * agent. Give them back a local channel number. */
3218 struct ssh_channel *c;
db7d555c 3219
3220 /* Refuse if agent forwarding is disabled. */
3221 if (!ssh_agentfwd_enabled) {
3222 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3223 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 3224 } else {
dcbde236 3225 c = smalloc(sizeof(struct ssh_channel));
db7d555c 3226 c->remoteid = GET_32BIT(pktin.body);
d2371c81 3227 c->localid = alloc_channel_id();
db7d555c 3228 c->closes = 0;
5471d09a 3229 c->v.v1.throttling = 0;
32874aea 3230 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3231 c->u.a.lensofar = 0;
3232 add234(ssh_channels, c);
3233 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3234 PKT_INT, c->remoteid, PKT_INT, c->localid,
3235 PKT_END);
3236 }
d74d141c 3237 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3238 /* Remote side is trying to open a channel to talk to a
3239 * forwarded port. Give them back a local channel number. */
3240 struct ssh_channel *c;
3241 struct ssh_rportfwd pf;
3242 int hostsize, port;
3243 char host[256], buf[1024];
3244 char *p, *h, *e;
3245 c = smalloc(sizeof(struct ssh_channel));
3246
3247 hostsize = GET_32BIT(pktin.body+4);
3248 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3249 if (h+1 < host+sizeof(host))
3250 *h++ = *p;
95bc8819 3251 p++;
d74d141c 3252 }
3253 *h = 0;
3254 port = GET_32BIT(p);
3255
bc240b21 3256 strcpy(pf.dhost, host);
3257 pf.dport = port;
d74d141c 3258
3259 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3260 sprintf(buf, "Rejected remote port open request for %s:%d",
3261 host, port);
3262 logevent(buf);
3263 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3264 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3265 } else {
3266 sprintf(buf, "Received remote port open request for %s:%d",
3267 host, port);
3268 logevent(buf);
3269 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3270 if (e != NULL) {
3271 char buf[256];
3272 sprintf(buf, "Port open failed: %s", e);
3273 logevent(buf);
3274 sfree(c);
3275 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3276 PKT_INT, GET_32BIT(pktin.body),
3277 PKT_END);
3278 } else {
3279 c->remoteid = GET_32BIT(pktin.body);
3280 c->localid = alloc_channel_id();
3281 c->closes = 0;
5471d09a 3282 c->v.v1.throttling = 0;
d74d141c 3283 c->type = CHAN_SOCKDATA; /* identify channel type */
3284 add234(ssh_channels, c);
3285 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3286 PKT_INT, c->remoteid, PKT_INT,
3287 c->localid, PKT_END);
3288 logevent("Forwarded port opened successfully");
3289 }
3290 }
3291
3292 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 3293 unsigned int remoteid = GET_32BIT(pktin.body);
3294 unsigned int localid = GET_32BIT(pktin.body+4);
3295 struct ssh_channel *c;
3296
3297 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3298 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3299 c->remoteid = localid;
3300 c->type = CHAN_SOCKDATA;
7781f316 3301 c->v.v1.throttling = 0;
bc240b21 3302 pfd_confirm(c->u.pfd.s);
3303 }
d74d141c 3304
4ed34d25 3305 if (c && c->closes) {
3306 /*
3307 * We have a pending close on this channel,
3308 * which we decided on before the server acked
3309 * the channel open. So now we know the
3310 * remoteid, we can close it again.
3311 */
3312 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3313 PKT_END);
3314 }
3315
724cface 3316 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3317 unsigned int remoteid = GET_32BIT(pktin.body);
3318 unsigned int localid = GET_32BIT(pktin.body+4);
3319 struct ssh_channel *c;
3320
3321 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3322 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3323 logevent("Forwarded connection refused by server");
3324 pfd_close(c->u.pfd.s);
3325 del234(ssh_channels, c);
3326 sfree(c);
3327 }
3328
db7d555c 3329 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3330 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3331 /* Remote side closes a channel. */
3332 unsigned i = GET_32BIT(pktin.body);
3333 struct ssh_channel *c;
3334 c = find234(ssh_channels, &i, ssh_channelfind);
3335 if (c) {
3336 int closetype;
3337 closetype =
3338 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3339 if (!(c->closes & closetype))
3340 send_packet(pktin.type, PKT_INT, c->remoteid,
3341 PKT_END);
783415f8 3342 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3343 logevent("Forwarded X11 connection terminated");
9c964e85 3344 assert(c->u.x11.s != NULL);
3345 x11_close(c->u.x11.s);
3346 c->u.x11.s = NULL;
3347 }
d74d141c 3348 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3349 logevent("Forwarded port closed");
3350 assert(c->u.pfd.s != NULL);
3351 pfd_close(c->u.pfd.s);
3352 c->u.pfd.s = NULL;
3353 }
32874aea 3354 c->closes |= closetype;
3355 if (c->closes == 3) {
3356 del234(ssh_channels, c);
3357 sfree(c);
3358 }
3359 }
3360 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3361 /* Data sent down one of our channels. */
3362 int i = GET_32BIT(pktin.body);
3363 int len = GET_32BIT(pktin.body + 4);
3364 unsigned char *p = pktin.body + 8;
3365 struct ssh_channel *c;
3366 c = find234(ssh_channels, &i, ssh_channelfind);
3367 if (c) {
5471d09a 3368 int bufsize;
32874aea 3369 switch (c->type) {
3370 case CHAN_X11:
5471d09a 3371 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3372 break;
d74d141c 3373 case CHAN_SOCKDATA:
5471d09a 3374 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3375 break;
32874aea 3376 case CHAN_AGENT:
3377 /* Data for an agent message. Buffer it. */
3378 while (len > 0) {
3379 if (c->u.a.lensofar < 4) {
3380 int l = min(4 - c->u.a.lensofar, len);
3381 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3382 l);
3383 p += l;
3384 len -= l;
3385 c->u.a.lensofar += l;
3386 }
3387 if (c->u.a.lensofar == 4) {
3388 c->u.a.totallen =
3389 4 + GET_32BIT(c->u.a.msglen);
3390 c->u.a.message = smalloc(c->u.a.totallen);
3391 memcpy(c->u.a.message, c->u.a.msglen, 4);
3392 }
3393 if (c->u.a.lensofar >= 4 && len > 0) {
3394 int l =
3395 min(c->u.a.totallen - c->u.a.lensofar,
3396 len);
3397 memcpy(c->u.a.message + c->u.a.lensofar, p,
3398 l);
3399 p += l;
3400 len -= l;
3401 c->u.a.lensofar += l;
3402 }
3403 if (c->u.a.lensofar == c->u.a.totallen) {
3404 void *reply, *sentreply;
3405 int replylen;
3406 agent_query(c->u.a.message,
3407 c->u.a.totallen, &reply,
3408 &replylen);
3409 if (reply)
3410 sentreply = reply;
3411 else {
3412 /* Fake SSH_AGENT_FAILURE. */
3413 sentreply = "\0\0\0\1\5";
3414 replylen = 5;
3415 }
3416 send_packet(SSH1_MSG_CHANNEL_DATA,
3417 PKT_INT, c->remoteid,
3418 PKT_INT, replylen,
3419 PKT_DATA, sentreply, replylen,
3420 PKT_END);
3421 if (reply)
3422 sfree(reply);
3423 sfree(c->u.a.message);
3424 c->u.a.lensofar = 0;
3425 }
3426 }
5471d09a 3427 bufsize = 0; /* agent channels never back up */
32874aea 3428 break;
3429 }
90347b95 3430 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3431 c->v.v1.throttling = 1;
3432 ssh1_throttle(+1);
3433 }
32874aea 3434 }
e5574168 3435 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3436 /* may be from EXEC_SHELL on some servers */
e5574168 3437 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3438 /* may be from EXEC_SHELL on some servers
374330e2 3439 * if no pty is available or in other odd cases. Ignore */
e5574168 3440 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3441 char buf[100];
3442 ssh_exitcode = GET_32BIT(pktin.body);
3443 sprintf(buf, "Server sent command exit status %d",
3444 ssh_exitcode);
3445 logevent(buf);
e5574168 3446 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3447 /*
3448 * In case `helpful' firewalls or proxies tack
3449 * extra human-readable text on the end of the
3450 * session which we might mistake for another
3451 * encrypted packet, we close the session once
3452 * we've sent EXIT_CONFIRMATION.
3453 */
3454 ssh_state = SSH_STATE_CLOSED;
3455 crReturnV;
374330e2 3456 } else {
8d5de777 3457 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3458 crReturnV;
374330e2 3459 }
3460 } else {
8df7a775 3461 while (inlen > 0) {
3462 int len = min(inlen, 512);
3463 send_packet(SSH1_CMSG_STDIN_DATA,
3464 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3465 in += len;
3466 inlen -= len;
3467 }
374330e2 3468 }
3469 }
3470
3471 crFinishV;
3472}
3473
3474/*
e5574168 3475 * Utility routine for decoding comma-separated strings in KEXINIT.
3476 */
32874aea 3477static int in_commasep_string(char *needle, char *haystack, int haylen)
3478{
e5574168 3479 int needlen = strlen(needle);
3480 while (1) {
32874aea 3481 /*
3482 * Is it at the start of the string?
3483 */
3484 if (haylen >= needlen && /* haystack is long enough */
3485 !memcmp(needle, haystack, needlen) && /* initial match */
3486 (haylen == needlen || haystack[needlen] == ',')
3487 /* either , or EOS follows */
3488 )
3489 return 1;
3490 /*
3491 * If not, search for the next comma and resume after that.
3492 * If no comma found, terminate.
3493 */
3494 while (haylen > 0 && *haystack != ',')
3495 haylen--, haystack++;
3496 if (haylen == 0)
3497 return 0;
3498 haylen--, haystack++; /* skip over comma itself */
e5574168 3499 }
3500}
3501
3502/*
d39f364a 3503 * SSH2 key creation method.
3504 */
32874aea 3505static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3506 char *keyspace)
3507{
d39f364a 3508 SHA_State s;
3509 /* First 20 bytes. */
3510 SHA_Init(&s);
088bde77 3511 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3512 sha_mpint(&s, K);
d39f364a 3513 SHA_Bytes(&s, H, 20);
3514 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3515 SHA_Bytes(&s, sessid, 20);
d39f364a 3516 SHA_Final(&s, keyspace);
3517 /* Next 20 bytes. */
3518 SHA_Init(&s);
088bde77 3519 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3520 sha_mpint(&s, K);
d39f364a 3521 SHA_Bytes(&s, H, 20);
3522 SHA_Bytes(&s, keyspace, 20);
32874aea 3523 SHA_Final(&s, keyspace + 20);
d39f364a 3524}
3525
3526/*
7cca0d81 3527 * Handle the SSH2 transport layer.
e5574168 3528 */
7cca0d81 3529static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3530{
ca20bfcf 3531 static int i, j, len, nbits, pbits, warn;
e5574168 3532 static char *str;
a92dd380 3533 static Bignum p, g, e, f, K;
3534 static int kex_init_value, kex_reply_value;
7591b9ff 3535 static const struct ssh_mac **maclist;
8b2715b2 3536 static int nmacs;
0a3f1d48 3537 static const struct ssh2_cipher *cscipher_tobe = NULL;
3538 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3539 static const struct ssh_mac *csmac_tobe = NULL;
3540 static const struct ssh_mac *scmac_tobe = NULL;
3541 static const struct ssh_compress *cscomp_tobe = NULL;
3542 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3543 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3544 static int hostkeylen, siglen;
e055a386 3545 static void *hkey; /* actual host key */
e5574168 3546 static unsigned char exchange_hash[20];
d39f364a 3547 static unsigned char keyspace[40];
ca20bfcf 3548 static int n_preferred_ciphers;
3549 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3550 static const struct ssh_compress *preferred_comp;
087abe1a 3551 static int cipherstr_started;
0db56f73 3552 static int first_kex;
e5574168 3553
3554 crBegin;
7cca0d81 3555 random_init();
0db56f73 3556 first_kex = 1;
e5574168 3557
5e8358ad 3558 /*
ca20bfcf 3559 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3560 */
ca20bfcf 3561 n_preferred_ciphers = 0;
3562 for (i = 0; i < CIPHER_MAX; i++) {
3563 switch (cfg.ssh_cipherlist[i]) {
3564 case CIPHER_BLOWFISH:
3565 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3566 n_preferred_ciphers++;
3567 break;
3568 case CIPHER_DES:
087abe1a 3569 if (cfg.ssh2_des_cbc) {
3570 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3571 n_preferred_ciphers++;
3572 }
ca20bfcf 3573 break;
3574 case CIPHER_3DES:
3575 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3576 n_preferred_ciphers++;
3577 break;
3578 case CIPHER_AES:
3579 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3580 n_preferred_ciphers++;
3581 break;
3582 case CIPHER_WARN:
3583 /* Flag for later. Don't bother if it's the last in
3584 * the list. */
3585 if (i < CIPHER_MAX - 1) {
3586 preferred_ciphers[n_preferred_ciphers] = NULL;
3587 n_preferred_ciphers++;
3588 }
3589 break;
3590 }
5e8358ad 3591 }
ca20bfcf 3592
3593 /*
3594 * Set up preferred compression.
3595 */
4ba9b64b 3596 if (cfg.compression)
3597 preferred_comp = &ssh_zlib;
3598 else
3599 preferred_comp = &ssh_comp_none;
5e8358ad 3600
7591b9ff 3601 /*
3602 * Be prepared to work around the buggy MAC problem.
3603 */
7d503c31 3604 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 3605 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3606 else
32874aea 3607 maclist = macs, nmacs = lenof(macs);
7591b9ff 3608
32874aea 3609 begin_key_exchange:
e5574168 3610 /*
3611 * Construct and send our key exchange packet.
3612 */
3613 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3614 for (i = 0; i < 16; i++)
32874aea 3615 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3616 /* List key exchange algorithms. */
3617 ssh2_pkt_addstring_start();
3618 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3619 ssh2_pkt_addstring_str(kex_algs[i]->name);
3620 if (i < lenof(kex_algs) - 1)
3621 ssh2_pkt_addstring_str(",");
e5574168 3622 }
3623 /* List server host key algorithms. */
3624 ssh2_pkt_addstring_start();
3625 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3626 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3627 if (i < lenof(hostkey_algs) - 1)
3628 ssh2_pkt_addstring_str(",");
e5574168 3629 }
3630 /* List client->server encryption algorithms. */
3631 ssh2_pkt_addstring_start();
087abe1a 3632 cipherstr_started = 0;
ca20bfcf 3633 for (i = 0; i < n_preferred_ciphers; i++) {
3634 const struct ssh2_ciphers *c = preferred_ciphers[i];
3635 if (!c) continue; /* warning flag */
32874aea 3636 for (j = 0; j < c->nciphers; j++) {
087abe1a 3637 if (cipherstr_started)
32874aea 3638 ssh2_pkt_addstring_str(",");
087abe1a 3639 ssh2_pkt_addstring_str(c->list[j]->name);
3640 cipherstr_started = 1;
32874aea 3641 }
e5574168 3642 }
3643 /* List server->client encryption algorithms. */
3644 ssh2_pkt_addstring_start();
087abe1a 3645 cipherstr_started = 0;
ca20bfcf 3646 for (i = 0; i < n_preferred_ciphers; i++) {
3647 const struct ssh2_ciphers *c = preferred_ciphers[i];
3648 if (!c) continue; /* warning flag */
32874aea 3649 for (j = 0; j < c->nciphers; j++) {
087abe1a 3650 if (cipherstr_started)
32874aea 3651 ssh2_pkt_addstring_str(",");
087abe1a 3652 ssh2_pkt_addstring_str(c->list[j]->name);
3653 cipherstr_started = 1;
32874aea 3654 }
e5574168 3655 }
3656 /* List client->server MAC algorithms. */
3657 ssh2_pkt_addstring_start();
8b2715b2 3658 for (i = 0; i < nmacs; i++) {
32874aea 3659 ssh2_pkt_addstring_str(maclist[i]->name);
3660 if (i < nmacs - 1)
3661 ssh2_pkt_addstring_str(",");
e5574168 3662 }
3663 /* List server->client MAC algorithms. */
3664 ssh2_pkt_addstring_start();
8b2715b2 3665 for (i = 0; i < nmacs; i++) {
32874aea 3666 ssh2_pkt_addstring_str(maclist[i]->name);
3667 if (i < nmacs - 1)
3668 ssh2_pkt_addstring_str(",");
e5574168 3669 }
3670 /* List client->server compression algorithms. */
3671 ssh2_pkt_addstring_start();
32874aea 3672 for (i = 0; i < lenof(compressions) + 1; i++) {
3673 const struct ssh_compress *c =
3674 i == 0 ? preferred_comp : compressions[i - 1];
3675 ssh2_pkt_addstring_str(c->name);
3676 if (i < lenof(compressions))
3677 ssh2_pkt_addstring_str(",");
e5574168 3678 }
3679 /* List server->client compression algorithms. */
3680 ssh2_pkt_addstring_start();
32874aea 3681 for (i = 0; i < lenof(compressions) + 1; i++) {
3682 const struct ssh_compress *c =
3683 i == 0 ? preferred_comp : compressions[i - 1];
3684 ssh2_pkt_addstring_str(c->name);
3685 if (i < lenof(compressions))
3686 ssh2_pkt_addstring_str(",");
e5574168 3687 }
3688 /* List client->server languages. Empty list. */
3689 ssh2_pkt_addstring_start();
3690 /* List server->client languages. Empty list. */
3691 ssh2_pkt_addstring_start();
3692 /* First KEX packet does _not_ follow, because we're not that brave. */
3693 ssh2_pkt_addbool(FALSE);
3694 /* Reserved. */
3695 ssh2_pkt_adduint32(0);
0db56f73 3696
3697 exhash = exhashbase;
32874aea 3698 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3699
e5574168 3700 ssh2_pkt_send();
3701
32874aea 3702 if (!ispkt)
3703 crWaitUntil(ispkt);
3704 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3705
3706 /*
3707 * Now examine the other side's KEXINIT to see what we're up
3708 * to.
3709 */
7cca0d81 3710 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3711 bombout(("expected key exchange packet from server"));
3712 crReturn(0);
7cca0d81 3713 }
32874aea 3714 kex = NULL;
3715 hostkey = NULL;
3716 cscipher_tobe = NULL;
3717 sccipher_tobe = NULL;
3718 csmac_tobe = NULL;
3719 scmac_tobe = NULL;
3720 cscomp_tobe = NULL;
3721 sccomp_tobe = NULL;
3722 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3723 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3724 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3725 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3726 kex = kex_algs[i];
3727 break;
3728 }
e5574168 3729 }
3730 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3731 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3732 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3733 hostkey = hostkey_algs[i];
3734 break;
3735 }
e5574168 3736 }
3737 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3738 warn = 0;
3739 for (i = 0; i < n_preferred_ciphers; i++) {
3740 const struct ssh2_ciphers *c = preferred_ciphers[i];
3741 if (!c) {
3742 warn = 1;
3743 } else {
3744 for (j = 0; j < c->nciphers; j++) {
3745 if (in_commasep_string(c->list[j]->name, str, len)) {
3746 cscipher_tobe = c->list[j];
3747 break;
3748 }
32874aea 3749 }
3750 }
ca20bfcf 3751 if (cscipher_tobe) {
3752 if (warn)
3753 askcipher(cscipher_tobe->name, 1);
32874aea 3754 break;
ca20bfcf 3755 }
e5574168 3756 }
0ef8f407 3757 if (!cscipher_tobe) {
3758 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3759 crReturn(0);
3760 }
3761
e5574168 3762 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3763 warn = 0;
3764 for (i = 0; i < n_preferred_ciphers; i++) {
3765 const struct ssh2_ciphers *c = preferred_ciphers[i];
3766 if (!c) {
3767 warn = 1;
3768 } else {
3769 for (j = 0; j < c->nciphers; j++) {
3770 if (in_commasep_string(c->list[j]->name, str, len)) {
3771 sccipher_tobe = c->list[j];
3772 break;
3773 }
32874aea 3774 }
3775 }
ca20bfcf 3776 if (sccipher_tobe) {
3777 if (warn)
3778 askcipher(sccipher_tobe->name, 2);
32874aea 3779 break;
ca20bfcf 3780 }
e5574168 3781 }
0ef8f407 3782 if (!sccipher_tobe) {
3783 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3784 crReturn(0);
3785 }
3786
e5574168 3787 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3788 for (i = 0; i < nmacs; i++) {
32874aea 3789 if (in_commasep_string(maclist[i]->name, str, len)) {
3790 csmac_tobe = maclist[i];
3791 break;
3792 }
e5574168 3793 }
3794 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3795 for (i = 0; i < nmacs; i++) {
32874aea 3796 if (in_commasep_string(maclist[i]->name, str, len)) {
3797 scmac_tobe = maclist[i];
3798 break;
3799 }
e5574168 3800 }
3801 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3802 for (i = 0; i < lenof(compressions) + 1; i++) {
3803 const struct ssh_compress *c =
3804 i == 0 ? preferred_comp : compressions[i - 1];
3805 if (in_commasep_string(c->name, str, len)) {
3806 cscomp_tobe = c;
3807 break;
3808 }
e5574168 3809 }
3810 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3811 for (i = 0; i < lenof(compressions) + 1; i++) {
3812 const struct ssh_compress *c =
3813 i == 0 ? preferred_comp : compressions[i - 1];
3814 if (in_commasep_string(c->name, str, len)) {
3815 sccomp_tobe = c;
3816 break;
3817 }
e5574168 3818 }
e5574168 3819
3820 /*
7bd5a860 3821 * Work out the number of bits of key we will need from the key
3822 * exchange. We start with the maximum key length of either
3823 * cipher...
3824 */
3825 {
32874aea 3826 int csbits, scbits;
7bd5a860 3827
3828 csbits = cscipher_tobe->keylen;
3829 scbits = sccipher_tobe->keylen;
3830 nbits = (csbits > scbits ? csbits : scbits);
3831 }
3832 /* The keys only have 160-bit entropy, since they're based on
3833 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3834 if (nbits > 160)
3835 nbits = 160;
7bd5a860 3836
3837 /*
a92dd380 3838 * If we're doing Diffie-Hellman group exchange, start by
3839 * requesting a group.
e5574168 3840 */
a92dd380 3841 if (kex == &ssh_diffiehellman_gex) {
32874aea 3842 logevent("Doing Diffie-Hellman group exchange");
00db133f 3843 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3844 /*
3845 * Work out how big a DH group we will need to allow that
3846 * much data.
7bd5a860 3847 */
32874aea 3848 pbits = 512 << ((nbits - 1) / 64);
3849 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3850 ssh2_pkt_adduint32(pbits);
3851 ssh2_pkt_send();
3852
3853 crWaitUntil(ispkt);
3854 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3855 bombout(("expected key exchange group packet from server"));
3856 crReturn(0);
3857 }
3858 p = ssh2_pkt_getmp();
3859 g = ssh2_pkt_getmp();
3860 dh_setup_group(p, g);
3861 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3862 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3863 } else {
00db133f 3864 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3865 dh_setup_group1();
3866 kex_init_value = SSH2_MSG_KEXDH_INIT;
3867 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3868 }
e5574168 3869
a92dd380 3870 logevent("Doing Diffie-Hellman key exchange");
e5574168 3871 /*
a92dd380 3872 * Now generate and send e for Diffie-Hellman.
e5574168 3873 */
32874aea 3874 e = dh_create_e(nbits * 2);
a92dd380 3875 ssh2_pkt_init(kex_init_value);
e5574168 3876 ssh2_pkt_addmp(e);
3877 ssh2_pkt_send();
3878
3879 crWaitUntil(ispkt);
a92dd380 3880 if (pktin.type != kex_reply_value) {
32874aea 3881 bombout(("expected key exchange reply packet from server"));
3882 crReturn(0);
7cca0d81 3883 }
e5574168 3884 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3885 f = ssh2_pkt_getmp();
e5574168 3886 ssh2_pkt_getstring(&sigdata, &siglen);
3887
3888 K = dh_find_K(f);
e5574168 3889
3890 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3891 if (kex == &ssh_diffiehellman_gex) {
32874aea 3892 sha_uint32(&exhash, pbits);
3893 sha_mpint(&exhash, p);
3894 sha_mpint(&exhash, g);
a92dd380 3895 }
e5574168 3896 sha_mpint(&exhash, e);
3897 sha_mpint(&exhash, f);
3898 sha_mpint(&exhash, K);
3899 SHA_Final(&exhash, exchange_hash);
3900
3709bfe9 3901 dh_cleanup();
3902
7cca0d81 3903#if 0
765c4200 3904 debug(("Exchange hash is:\n"));
3905 dmemdump(exchange_hash, 20);
7cca0d81 3906#endif
3907
e055a386 3908 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3909 if (!hkey ||
3910 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3911 bombout(("Server's host key did not match the signature supplied"));
32874aea 3912 crReturn(0);
8d5de777 3913 }
e5574168 3914
3915 /*
7cca0d81 3916 * Authenticate remote host: verify host key. (We've already
3917 * checked the signature of the exchange hash.)
e5574168 3918 */
e055a386 3919 keystr = hostkey->fmtkey(hkey);
3920 fingerprint = hostkey->fingerprint(hkey);
d4857987 3921 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3922 keystr, fingerprint);
3923 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3924 logevent("Host key fingerprint is:");
3925 logevent(fingerprint);
3926 }
dcbde236 3927 sfree(fingerprint);
3928 sfree(keystr);
e055a386 3929 hostkey->freekey(hkey);
d39f364a 3930
3931 /*
7cca0d81 3932 * Send SSH2_MSG_NEWKEYS.
d39f364a 3933 */
3934 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3935 ssh2_pkt_send();
d39f364a 3936
3937 /*
8406eaf9 3938 * Expect SSH2_MSG_NEWKEYS from server.
3939 */
3940 crWaitUntil(ispkt);
3941 if (pktin.type != SSH2_MSG_NEWKEYS) {
3942 bombout(("expected new-keys packet from server"));
3943 crReturn(0);
3944 }
3945
3946 /*
d39f364a 3947 * Create and initialise session keys.
3948 */
3949 cscipher = cscipher_tobe;
3950 sccipher = sccipher_tobe;
3951 csmac = csmac_tobe;
3952 scmac = scmac_tobe;
3953 cscomp = cscomp_tobe;
3954 sccomp = sccomp_tobe;
4ba9b64b 3955 cscomp->compress_init();
3956 sccomp->decompress_init();
d39f364a 3957 /*
5e0d7cb8 3958 * Set IVs after keys. Here we use the exchange hash from the
3959 * _first_ key exchange.
d39f364a 3960 */
5e0d7cb8 3961 if (first_kex)
65a22376 3962 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3963 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3964 cscipher->setcskey(keyspace);
65a22376 3965 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3966 sccipher->setsckey(keyspace);
65a22376 3967 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3968 cscipher->setcsiv(keyspace);
65a22376 3969 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3970 sccipher->setsciv(keyspace);
65a22376 3971 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3972 csmac->setcskey(keyspace);
65a22376 3973 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3974 scmac->setsckey(keyspace);
d39f364a 3975
033b4cef 3976 /*
0db56f73 3977 * If this is the first key exchange phase, we must pass the
3978 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3979 * wants to see it but because it will need time to initialise
3980 * itself before it sees an actual packet. In subsequent key
3981 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3982 * it would only confuse the layer above.
3983 */
3984 if (!first_kex) {
32874aea 3985 crReturn(0);
0db56f73 3986 }
3987 first_kex = 0;
3988
3989 /*
7cca0d81 3990 * Now we're encrypting. Begin returning 1 to the protocol main
3991 * function so that other things can run on top of the
3992 * transport. If we ever see a KEXINIT, we must go back to the
3993 * start.
033b4cef 3994 */
e96adf72 3995 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3996 crReturn(1);
e96adf72 3997 }
5e0d7cb8 3998 logevent("Server initiated key re-exchange");
7cca0d81 3999 goto begin_key_exchange;
e5574168 4000
4001 crFinish(1);
4002}
4003
7cca0d81 4004/*
783415f8 4005 * Add data to an SSH2 channel output buffer.
4006 */
32874aea 4007static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4008 int len)
4009{
5471d09a 4010 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4011}
4012
4013/*
4014 * Attempt to send data on an SSH2 channel.
4015 */
5471d09a 4016static int ssh2_try_send(struct ssh_channel *c)
32874aea 4017{
5471d09a 4018 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4019 int len;
4020 void *data;
4021 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4022 if ((unsigned)len > c->v.v2.remwindow)
4023 len = c->v.v2.remwindow;
4024 if ((unsigned)len > c->v.v2.remmaxpkt)
4025 len = c->v.v2.remmaxpkt;
32874aea 4026 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4027 ssh2_pkt_adduint32(c->remoteid);
4028 ssh2_pkt_addstring_start();
5471d09a 4029 ssh2_pkt_addstring_data(data, len);
32874aea 4030 ssh2_pkt_send();
5471d09a 4031 bufchain_consume(&c->v.v2.outbuffer, len);
4032 c->v.v2.remwindow -= len;
4033 }
4034
4035 /*
4036 * After having sent as much data as we can, return the amount
4037 * still buffered.
4038 */
4039 return bufchain_size(&c->v.v2.outbuffer);
4040}
4041
4042/*
4043 * Potentially enlarge the window on an SSH2 channel.
4044 */
4045static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4046{
6b69f42e 4047 /*
4048 * Never send WINDOW_ADJUST for a channel that the remote side
4049 * already thinks it's closed; there's no point, since it won't
4050 * be sending any more data anyway.
4051 */
4052 if (c->closes != 0)
4053 return;
4054
5471d09a 4055 if (newwin > c->v.v2.locwindow) {
4056 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4057 ssh2_pkt_adduint32(c->remoteid);
4058 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4059 ssh2_pkt_send();
4060 c->v.v2.locwindow = newwin;
783415f8 4061 }
4062}
4063
4064/*
7cca0d81 4065 * Handle the SSH2 userauth and connection layers.
4066 */
4067static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4068{
65a22376 4069 static enum {
32874aea 4070 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 4071 AUTH_PASSWORD,
4072 AUTH_KEYBOARD_INTERACTIVE
65a22376 4073 } method;
1408a877 4074 static enum {
32874aea 4075 AUTH_TYPE_NONE,
4076 AUTH_TYPE_PUBLICKEY,
4077 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4078 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 4079 AUTH_TYPE_PASSWORD,
4bdf7c46 4080 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4081 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 4082 } type;
761187b6 4083 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4084 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 4085 static int kbd_inter_running;
1408a877 4086 static int we_are_in;
45068b27 4087 static int num_prompts, curr_prompt, echo;
65a22376 4088 static char username[100];
7e9b7f4b 4089 static int got_username;
65a22376 4090 static char pwprompt[200];
4091 static char password[100];
396778f1 4092 static void *publickey_blob;
4093 static int publickey_bloblen;
7cca0d81 4094
e5574168 4095 crBegin;
4096
7cca0d81 4097 /*
4098 * Request userauth protocol, and await a response to it.
4099 */
4100 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4101 ssh2_pkt_addstring("ssh-userauth");
4102 ssh2_pkt_send();
4103 crWaitUntilV(ispkt);
8d5de777 4104 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4105 bombout(("Server refused user authentication protocol"));
4106 crReturnV;
8d5de777 4107 }
7cca0d81 4108
4109 /*
1408a877 4110 * We repeat this whole loop, including the username prompt,
4111 * until we manage a successful authentication. If the user
4112 * types the wrong _password_, they are sent back to the
4113 * beginning to try another username. (If they specify a
4114 * username in the config, they are never asked, even if they
4115 * do give a wrong password.)
4116 *
4117 * I think this best serves the needs of
4118 *
4119 * - the people who have no configuration, no keys, and just
4120 * want to try repeated (username,password) pairs until they
4121 * type both correctly
4122 *
4123 * - people who have keys and configuration but occasionally
4124 * need to fall back to passwords
4125 *
4126 * - people with a key held in Pageant, who might not have
4127 * logged in to a particular machine before; so they want to
4128 * type a username, and then _either_ their key will be
4129 * accepted, _or_ they will type a password. If they mistype
4130 * the username they will want to be able to get back and
4131 * retype it!
7cca0d81 4132 */
5bb641e1 4133 username[0] = '\0';
7e9b7f4b 4134 got_username = FALSE;
1408a877 4135 do {
1408a877 4136 /*
4137 * Get a username.
4138 */
7e9b7f4b 4139 if (got_username && !cfg.change_username) {
5bb641e1 4140 /*
4141 * We got a username last time round this loop, and
4142 * with change_username turned off we don't try to get
4143 * it again.
4144 */
4145 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4146 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4147 if (!ssh_get_line("login as: ",
4148 username, sizeof(username), FALSE)) {
4149 /*
4150 * get_line failed to get a username.
4151 * Terminate.
4152 */
4153 logevent("No username provided. Abandoning session.");
4154 ssh_state = SSH_STATE_CLOSED;
4155 crReturnV;
4156 }
4157 } else {
0405e71f 4158 static int ret;
32874aea 4159 c_write_str("login as: ");
4160 ssh_send_ok = 1;
0405e71f 4161 setup_userpass_input(username, sizeof(username), 1);
4162 do {
32874aea 4163 crWaitUntilV(!ispkt);
0405e71f 4164 ret = process_userpass_input(in, inlen);
4165 } while (ret == 0);
4166 if (ret < 0)
4167 cleanup_exit(0);
32874aea 4168 }
1408a877 4169 c_write_str("\r\n");
7cca0d81 4170 username[strcspn(username, "\n\r")] = '\0';
4171 } else {
4172 char stuff[200];
4173 strncpy(username, cfg.username, 99);
4174 username[99] = '\0';
65a22376 4175 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 4176 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 4177 c_write_str(stuff);
7cca0d81 4178 }
4179 }
7e9b7f4b 4180 got_username = TRUE;
7cca0d81 4181
65a22376 4182 /*
1408a877 4183 * Send an authentication request using method "none": (a)
4184 * just in case it succeeds, and (b) so that we know what
4185 * authentication methods we can usefully try next.
65a22376 4186 */
00db133f 4187 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4188
1408a877 4189 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4190 ssh2_pkt_addstring(username);
32874aea 4191 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4192 ssh2_pkt_addstring("none"); /* method */
4193 ssh2_pkt_send();
4194 type = AUTH_TYPE_NONE;
4195 gotit = FALSE;
4196 we_are_in = FALSE;
7cca0d81 4197
1408a877 4198 tried_pubkey_config = FALSE;
1983e559 4199 tried_agent = FALSE;
b3186d64 4200 tried_keyb_inter = FALSE;
4201 kbd_inter_running = FALSE;
396778f1 4202 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4203 if (*cfg.keyfile) {
231ee168 4204 int keytype;
4205 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4206 keytype = key_type(cfg.keyfile);
4207 if (keytype == SSH_KEYTYPE_SSH2)
4208 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4209 &publickey_bloblen);
4210 else {
4211 char msgbuf[256];
4212 logeventf("Unable to use this key file (%s)",
4213 key_type_to_str(keytype));
4214 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4215 cfg.keyfile, key_type_to_str(keytype));
4216 c_write_str(msgbuf);
4217 publickey_blob = NULL;
4218 }
396778f1 4219 } else
4220 publickey_blob = NULL;
65a22376 4221
1408a877 4222 while (1) {
4223 /*
4224 * Wait for the result of the last authentication request.
4225 */
4226 if (!gotit)
4227 crWaitUntilV(ispkt);
4228 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4229 char *banner;
4230 int size;
4231 /*
4232 * Don't show the banner if we're operating in
4233 * non-verbose non-interactive mode. (It's probably
4234 * a script, which means nobody will read the
4235 * banner _anyway_, and moreover the printing of
4236 * the banner will screw up processing on the
4237 * output of (say) plink.)
4238 */
4239 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4240 ssh2_pkt_getstring(&banner, &size);
4241 if (banner)
4242 c_write_untrusted(banner, size);
4243 }
1408a877 4244 crWaitUntilV(ispkt);
4245 }
4246 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4247 logevent("Access granted");
4248 we_are_in = TRUE;
4249 break;
4250 }
65a22376 4251
b3186d64 4252 if (kbd_inter_running &&
4253 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4254 /*
45068b27 4255 * This is either a further set-of-prompts packet
4256 * in keyboard-interactive authentication, or it's
4257 * the same one and we came back here with `gotit'
4258 * set. In the former case, we must reset the
4259 * curr_prompt variable.
b3186d64 4260 */
45068b27 4261 if (!gotit)
4262 curr_prompt = 0;
6bb26b30 4263 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4264 bombout(("Strange packet received during authentication: type %d",
1408a877 4265 pktin.type));
38c4a8da 4266 crReturnV;
65a22376 4267 }
4268
1408a877 4269 gotit = FALSE;
65a22376 4270
1408a877 4271 /*
4272 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4273 * we can look at the string in it and know what we can
4274 * helpfully try next.
4275 */
b3186d64 4276 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4277 char *methods;
4278 int methlen;
4279 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 4280 kbd_inter_running = FALSE;
1408a877 4281 if (!ssh2_pkt_getbool()) {
4282 /*
4283 * We have received an unequivocal Access
4284 * Denied. This can translate to a variety of
4285 * messages:
4286 *
4287 * - if we'd just tried "none" authentication,
4288 * it's not worth printing anything at all
4289 *
4290 * - if we'd just tried a public key _offer_,
4291 * the message should be "Server refused our
4292 * key" (or no message at all if the key
4293 * came from Pageant)
4294 *
4295 * - if we'd just tried anything else, the
4296 * message really should be "Access denied".
4297 *
4298 * Additionally, if we'd just tried password
4299 * authentication, we should break out of this
4300 * whole loop so as to go back to the username
4301 * prompt.
4302 */
4303 if (type == AUTH_TYPE_NONE) {
4304 /* do nothing */
4305 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4306 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4307 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4308 c_write_str("Server refused our key\r\n");
4309 logevent("Server refused public key");
4bdf7c46 4310 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4311 /* server declined keyboard-interactive; ignore */
1408a877 4312 } else {
4313 c_write_str("Access denied\r\n");
4314 logevent("Access denied");
4315 if (type == AUTH_TYPE_PASSWORD) {
4316 we_are_in = FALSE;
4317 break;
4318 }
4319 }
4320 } else {
4321 c_write_str("Further authentication required\r\n");
4322 logevent("Further authentication required");
4323 }
65a22376 4324
32874aea 4325 can_pubkey =
4326 in_commasep_string("publickey", methods, methlen);
4327 can_passwd =
4328 in_commasep_string("password", methods, methlen);
f091e308 4329 can_keyb_inter = cfg.try_ki_auth &&
761187b6 4330 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4331 }
65a22376 4332
1408a877 4333 method = 0;
00db133f 4334 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4335
0405e71f 4336 /*
4337 * Most password/passphrase prompts will be
4338 * non-echoing, so we set this to 0 by default.
4339 * Exception is that some keyboard-interactive prompts
4340 * can be echoing, in which case we'll set this to 1.
4341 */
4342 echo = 0;
4343
78afa559 4344 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 4345 /*
4346 * Attempt public-key authentication using Pageant.
4347 */
4348 static unsigned char request[5], *response, *p;
4349 static int responselen;
4350 static int i, nkeys;
4351 static int authed = FALSE;
4352 void *r;
4353
c0a81592 4354 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4355 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4356
1983e559 4357 tried_agent = TRUE;
4358
4359 logevent("Pageant is running. Requesting keys.");
4360
4361 /* Request the keys held by the agent. */
4362 PUT_32BIT(request, 1);
4363 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4364 agent_query(request, 5, &r, &responselen);
32874aea 4365 response = (unsigned char *) r;
95797139 4366 if (response && responselen >= 5 &&
32874aea 4367 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 4368 p = response + 5;
32874aea 4369 nkeys = GET_32BIT(p);
4370 p += 4;
4371 {
4372 char buf[64];
4373 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4374 logevent(buf);
4375 }
1983e559 4376 for (i = 0; i < nkeys; i++) {
4377 static char *pkblob, *alg, *commentp;
4378 static int pklen, alglen, commentlen;
4379 static int siglen, retlen, len;
4380 static char *q, *agentreq, *ret;
2d466ffd 4381 void *vret;
1983e559 4382
32874aea 4383 {
4384 char buf[64];
4385 sprintf(buf, "Trying Pageant key #%d", i);
4386 logevent(buf);
4387 }
4388 pklen = GET_32BIT(p);
4389 p += 4;
396778f1 4390 if (publickey_blob &&
4391 pklen == publickey_bloblen &&
4392 !memcmp(p, publickey_blob, publickey_bloblen)) {
4393 logevent("This key matches configured key file");
4394 tried_pubkey_config = 1;
4395 }
32874aea 4396 pkblob = p;
4397 p += pklen;
1983e559 4398 alglen = GET_32BIT(pkblob);
4399 alg = pkblob + 4;
32874aea 4400 commentlen = GET_32BIT(p);
4401 p += 4;
4402 commentp = p;
4403 p += commentlen;
1983e559 4404 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4405 ssh2_pkt_addstring(username);
32874aea 4406 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4407 ssh2_pkt_addstring("publickey"); /* method */
4408 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 4409 ssh2_pkt_addstring_start();
4410 ssh2_pkt_addstring_data(alg, alglen);
4411 ssh2_pkt_addstring_start();
4412 ssh2_pkt_addstring_data(pkblob, pklen);
4413 ssh2_pkt_send();
4414
4415 crWaitUntilV(ispkt);
4416 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4417 logevent("Key refused");
4418 continue;
4419 }
4420
32874aea 4421 if (flags & FLAG_VERBOSE) {
4422 c_write_str
4423 ("Authenticating with public key \"");
4424 c_write(commentp, commentlen);
4425 c_write_str("\" from agent\r\n");
4426 }
1983e559 4427
4428 /*
4429 * Server is willing to accept the key.
4430 * Construct a SIGN_REQUEST.
4431 */
4432 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4433 ssh2_pkt_addstring(username);
32874aea 4434 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4435 ssh2_pkt_addstring("publickey"); /* method */
1983e559 4436 ssh2_pkt_addbool(TRUE);
4437 ssh2_pkt_addstring_start();
4438 ssh2_pkt_addstring_data(alg, alglen);
4439 ssh2_pkt_addstring_start();
4440 ssh2_pkt_addstring_data(pkblob, pklen);
4441
4442 siglen = pktout.length - 5 + 4 + 20;
32874aea 4443 len = 1; /* message type */
4444 len += 4 + pklen; /* key blob */
4445 len += 4 + siglen; /* data to sign */
4446 len += 4; /* flags */
1983e559 4447 agentreq = smalloc(4 + len);
4448 PUT_32BIT(agentreq, len);
4449 q = agentreq + 4;
4450 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4451 PUT_32BIT(q, pklen);
4452 q += 4;
4453 memcpy(q, pkblob, pklen);
4454 q += pklen;
4455 PUT_32BIT(q, siglen);
4456 q += 4;
1983e559 4457 /* Now the data to be signed... */
32874aea 4458 PUT_32BIT(q, 20);
4459 q += 4;
4460 memcpy(q, ssh2_session_id, 20);
4461 q += 20;
4462 memcpy(q, pktout.data + 5, pktout.length - 5);
4463 q += pktout.length - 5;
1983e559 4464 /* And finally the (zero) flags word. */
4465 PUT_32BIT(q, 0);
2d466ffd 4466 agent_query(agentreq, len + 4, &vret, &retlen);
4467 ret = vret;
1983e559 4468 sfree(agentreq);
4469 if (ret) {
4470 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4471 logevent("Sending Pageant's response");
1dd353b5 4472 ssh2_add_sigblob(pkblob, pklen,
4473 ret + 9, GET_32BIT(ret + 5));
1983e559 4474 ssh2_pkt_send();
4475 authed = TRUE;
4476 break;
4477 } else {
32874aea 4478 logevent
4479 ("Pageant failed to answer challenge");
1983e559 4480 sfree(ret);
4481 }
4482 }
4483 }
4484 if (authed)
4485 continue;
4486 }
4487 }
4488
231ee168 4489 if (!method && can_pubkey && publickey_blob
32874aea 4490 && !tried_pubkey_config) {
1408a877 4491 unsigned char *pub_blob;
4492 char *algorithm, *comment;
4493 int pub_blob_len;
65a22376 4494
1408a877 4495 tried_pubkey_config = TRUE;
65a22376 4496
c0a81592 4497 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4498 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4499
65a22376 4500 /*
1408a877 4501 * Try the public key supplied in the configuration.
4502 *
4503 * First, offer the public blob to see if the server is
4504 * willing to accept it.
65a22376 4505 */
1408a877 4506 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4507 &pub_blob_len);
4508 if (pub_blob) {
4509 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4510 ssh2_pkt_addstring(username);
32874aea 4511 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4512 ssh2_pkt_addstring("publickey"); /* method */
4513 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4514 ssh2_pkt_addstring(algorithm);
4515 ssh2_pkt_addstring_start();
4516 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4517 ssh2_pkt_send();
32874aea 4518 logevent("Offered public key"); /* FIXME */
1408a877 4519
4520 crWaitUntilV(ispkt);
4521 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4522 gotit = TRUE;
4523 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4524 continue; /* key refused; give up on it */
1408a877 4525 }
65a22376 4526
1408a877 4527 logevent("Offer of public key accepted");
65a22376 4528 /*
1408a877 4529 * Actually attempt a serious authentication using
4530 * the key.
65a22376 4531 */
1408a877 4532 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4533 sprintf(pwprompt,
4534 "Passphrase for key \"%.100s\": ",
4535 comment);
1408a877 4536 need_pw = TRUE;
4537 } else {
4538 need_pw = FALSE;
4539 }
4540 c_write_str("Authenticating with public key \"");
4541 c_write_str(comment);
4542 c_write_str("\"\r\n");
4543 method = AUTH_PUBLICKEY_FILE;
65a22376 4544 }
1408a877 4545 }
4546
af659722 4547 if (!method && can_keyb_inter && !tried_keyb_inter) {
4548 method = AUTH_KEYBOARD_INTERACTIVE;
4549 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4550 tried_keyb_inter = TRUE;
4551
c0a81592 4552 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4553 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4554
af659722 4555 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4556 ssh2_pkt_addstring(username);
4557 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4558 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4559 ssh2_pkt_addstring(""); /* lang */
4560 ssh2_pkt_addstring("");
4561 ssh2_pkt_send();
4562
4563 crWaitUntilV(ispkt);
4564 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4565 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4566 gotit = TRUE;
4567 logevent("Keyboard-interactive authentication refused");
4568 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4569 continue;
4570 }
4571
4572 kbd_inter_running = TRUE;
45068b27 4573 curr_prompt = 0;
af659722 4574 }
4575
4576 if (kbd_inter_running) {
4577 method = AUTH_KEYBOARD_INTERACTIVE;
4578 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4579 tried_keyb_inter = TRUE;
4580
c0a81592 4581 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4582 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4583
45068b27 4584 if (curr_prompt == 0) {
4585 /*
4586 * We've got a fresh USERAUTH_INFO_REQUEST.
4587 * Display header data, and start going through
4588 * the prompts.
4589 */
4590 char *name, *inst, *lang;
4591 int name_len, inst_len, lang_len;
4592
af659722 4593 ssh2_pkt_getstring(&name, &name_len);
4594 ssh2_pkt_getstring(&inst, &inst_len);
4595 ssh2_pkt_getstring(&lang, &lang_len);
45068b27 4596 if (name_len > 0) {
af659722 4597 c_write_untrusted(name, name_len);
0405e71f 4598 c_write_str("\r\n");
45068b27 4599 }
4600 if (inst_len > 0) {
af659722 4601 c_write_untrusted(inst, inst_len);
0405e71f 4602 c_write_str("\r\n");
45068b27 4603 }
af659722 4604 num_prompts = ssh2_pkt_getuint32();
45068b27 4605 }
af659722 4606
45068b27 4607 /*
4608 * If there are prompts remaining in the packet,
4609 * display one and get a response.
4610 */
4611 if (curr_prompt < num_prompts) {
4612 char *prompt;
4613 int prompt_len;
af659722 4614
45068b27 4615 ssh2_pkt_getstring(&prompt, &prompt_len);
4616 if (prompt_len > 0) {
4617 strncpy(pwprompt, prompt, sizeof(pwprompt));
4618 pwprompt[prompt_len < sizeof(pwprompt) ?
4619 prompt_len : sizeof(pwprompt)-1] = '\0';
4620 } else {
4621 strcpy(pwprompt,
4622 "<server failed to send prompt>: ");
4623 }
af659722 4624 echo = ssh2_pkt_getbool();
45068b27 4625 need_pw = TRUE;
4626 } else
4627 need_pw = FALSE;
af659722 4628 }
4629
1408a877 4630 if (!method && can_passwd) {
4631 method = AUTH_PASSWORD;
c0a81592 4632 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4633 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
32874aea 4634 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4635 savedhost);
1408a877 4636 need_pw = TRUE;
4637 }
4638
4639 if (need_pw) {
fa17a66e 4640 if (ssh_get_line) {
4641 if (!ssh_get_line(pwprompt, password,
32874aea 4642 sizeof(password), TRUE)) {
1408a877 4643 /*
fa17a66e 4644 * get_line failed to get a password (for
4645 * example because one was supplied on the
4646 * command line which has already failed to
4647 * work). Terminate.
1408a877 4648 */
2bc6a386 4649 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4650 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4651 ssh2_pkt_addstring
4652 ("No more passwords available to try");
4653 ssh2_pkt_addstring("en"); /* language tag */
4654 ssh2_pkt_send();
247308b5 4655 logevent("Unable to authenticate");
2bc6a386 4656 connection_fatal("Unable to authenticate");
1408a877 4657 ssh_state = SSH_STATE_CLOSED;
4658 crReturnV;
4659 }
4660 } else {
0405e71f 4661 static int ret;
761187b6 4662 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4663 ssh_send_ok = 1;
4664
0405e71f 4665 setup_userpass_input(password, sizeof(password), echo);
4666 do {
1408a877 4667 crWaitUntilV(!ispkt);
0405e71f 4668 ret = process_userpass_input(in, inlen);
4669 } while (ret == 0);
4670 if (ret < 0)
4671 cleanup_exit(0);
1408a877 4672 c_write_str("\r\n");
65a22376 4673 }
65a22376 4674 }
65a22376 4675
1408a877 4676 if (method == AUTH_PUBLICKEY_FILE) {
4677 /*
4678 * We have our passphrase. Now try the actual authentication.
4679 */
4680 struct ssh2_userkey *key;
65a22376 4681
1408a877 4682 key = ssh2_load_userkey(cfg.keyfile, password);
4683 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4684 if (key == SSH2_WRONG_PASSPHRASE) {
4685 c_write_str("Wrong passphrase\r\n");
4686 tried_pubkey_config = FALSE;
4687 } else {
4688 c_write_str("Unable to load private key\r\n");
4689 tried_pubkey_config = TRUE;
4690 }
4691 /* Send a spurious AUTH_NONE to return to the top. */
4692 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4693 ssh2_pkt_addstring(username);
32874aea 4694 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4695 ssh2_pkt_addstring("none"); /* method */
1408a877 4696 ssh2_pkt_send();
4697 type = AUTH_TYPE_NONE;
4698 } else {
1dd353b5 4699 unsigned char *pkblob, *sigblob, *sigdata;
4700 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4701
1408a877 4702 /*
4703 * We have loaded the private key and the server
4704 * has announced that it's willing to accept it.
4705 * Hallelujah. Generate a signature and send it.
4706 */
4707 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4708 ssh2_pkt_addstring(username);
32874aea 4709 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4710 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4711 ssh2_pkt_addbool(TRUE);
4712 ssh2_pkt_addstring(key->alg->name);
1dd353b5 4713 pkblob = key->alg->public_blob(key->data, &pkblob_len);
1408a877 4714 ssh2_pkt_addstring_start();
1dd353b5 4715 ssh2_pkt_addstring_data(pkblob, pkblob_len);
1408a877 4716
4717 /*
4718 * The data to be signed is:
4719 *
4720 * string session-id
4721 *
4722 * followed by everything so far placed in the
4723 * outgoing packet.
4724 */
4725 sigdata_len = pktout.length - 5 + 4 + 20;
4726 sigdata = smalloc(sigdata_len);
4727 PUT_32BIT(sigdata, 20);
32874aea 4728 memcpy(sigdata + 4, ssh2_session_id, 20);
4729 memcpy(sigdata + 24, pktout.data + 5,
4730 pktout.length - 5);
1dd353b5 4731 sigblob = key->alg->sign(key->data, sigdata,
4732 sigdata_len, &sigblob_len);
4733 ssh2_add_sigblob(pkblob, pkblob_len,
4734 sigblob, sigblob_len);
4735 sfree(pkblob);
4736 sfree(sigblob);
1408a877 4737 sfree(sigdata);
4738
4739 ssh2_pkt_send();
4740 type = AUTH_TYPE_PUBLICKEY;
4741 }
4742 } else if (method == AUTH_PASSWORD) {
65a22376 4743 /*
1408a877 4744 * We send the password packet lumped tightly together with
4745 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4746 * string long enough to make the total length of the two
4747 * packets constant. This should ensure that a passive
4748 * listener doing traffic analyis can't work out the length
4749 * of the password.
4750 *
4751 * For this to work, we need an assumption about the
4752 * maximum length of the password packet. I think 256 is
4753 * pretty conservative. Anyone using a password longer than
4754 * that probably doesn't have much to worry about from
4755 * people who find out how long their password is!
65a22376 4756 */
4757 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4758 ssh2_pkt_addstring(username);
32874aea 4759 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4760 ssh2_pkt_addstring("password");
4761 ssh2_pkt_addbool(FALSE);
4762 ssh2_pkt_addstring(password);
4763 ssh2_pkt_defer();
65a22376 4764 /*
1408a877 4765 * We'll include a string that's an exact multiple of the
4766 * cipher block size. If the cipher is NULL for some
4767 * reason, we don't do this trick at all because we gain
4768 * nothing by it.
65a22376 4769 */
32874aea 4770 if (cscipher) {
4771 int stringlen, i;
4772
4773 stringlen = (256 - deferred_len);
4774 stringlen += cscipher->blksize - 1;
4775 stringlen -= (stringlen % cscipher->blksize);
4776 if (cscomp) {
4777 /*
4778 * Temporarily disable actual compression,
4779 * so we can guarantee to get this string
4780 * exactly the length we want it. The
4781 * compression-disabling routine should
4782 * return an integer indicating how many
4783 * bytes we should adjust our string length
4784 * by.
4785 */
4786 stringlen -= cscomp->disable_compression();
4787 }
1408a877 4788 ssh2_pkt_init(SSH2_MSG_IGNORE);
4789 ssh2_pkt_addstring_start();
6e9e9520 4790 for (i = 0; i < stringlen; i++) {
32874aea 4791 char c = (char) random_byte();
4792 ssh2_pkt_addstring_data(&c, 1);
65a22376 4793 }
1408a877 4794 ssh2_pkt_defer();
65a22376 4795 }
39065bed 4796 ssh_pkt_defersend();
0d43337a 4797 logevent("Sent password");
1408a877 4798 type = AUTH_TYPE_PASSWORD;
761187b6 4799 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
45068b27 4800 if (curr_prompt == 0) {
4801 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4802 ssh2_pkt_adduint32(num_prompts);
4803 }
4804 if (need_pw) { /* only add pw if we just got one! */
4805 ssh2_pkt_addstring(password);
4806 memset(password, 0, sizeof(password));
4807 curr_prompt++;
4808 }
4809 if (curr_prompt >= num_prompts) {
4810 ssh2_pkt_send();
4811 } else {
4812 /*
4813 * If there are prompts remaining, we set
4814 * `gotit' so that we won't attempt to get
4815 * another packet. Then we go back round the
4816 * loop and will end up retrieving another
4817 * prompt out of the existing packet. Funky or
4818 * what?
4819 */
4820 gotit = TRUE;
4821 }
761187b6 4822 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4823 } else {
32874aea 4824 c_write_str
4825 ("No supported authentication methods left to try!\r\n");
4826 logevent
4827 ("No supported authentications offered. Disconnecting");
1408a877 4828 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4829 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4830 ssh2_pkt_addstring
4831 ("No supported authentication methods available");
4832 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4833 ssh2_pkt_send();
4834 ssh_state = SSH_STATE_CLOSED;
4835 crReturnV;
65a22376 4836 }
65a22376 4837 }
1408a877 4838 } while (!we_are_in);
7cca0d81 4839
4840 /*
4841 * Now we're authenticated for the connection protocol. The
4842 * connection protocol will automatically have started at this
4843 * point; there's no need to send SERVICE_REQUEST.
4844 */
4845
4846 /*
4847 * So now create a channel with a session in it.
4848 */
d2371c81 4849 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4850 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4851 mainchan->localid = alloc_channel_id();
7cca0d81 4852 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4853 ssh2_pkt_addstring("session");
d211621f 4854 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4855 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4856 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4857 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4858 ssh2_pkt_send();
4859 crWaitUntilV(ispkt);
4860 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4861 bombout(("Server refused to open a session"));
4862 crReturnV;
4863 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4864 }
d211621f 4865 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4866 bombout(("Server's channel confirmation cited wrong channel"));
4867 crReturnV;
7cca0d81 4868 }
d211621f 4869 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4870 mainchan->type = CHAN_MAINSESSION;
4871 mainchan->closes = 0;
5471d09a 4872 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4873 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4874 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4875 add234(ssh_channels, mainchan);
7cca0d81 4876 logevent("Opened channel for session");
4877
4878 /*
783415f8 4879 * Potentially enable X11 forwarding.
4880 */
4881 if (cfg.x11_forward) {
32874aea 4882 char proto[20], data[64];
4883 logevent("Requesting X11 forwarding");
4884 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4885 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4886 ssh2_pkt_adduint32(mainchan->remoteid);
4887 ssh2_pkt_addstring("x11-req");
4888 ssh2_pkt_addbool(1); /* want reply */
4889 ssh2_pkt_addbool(0); /* many connections */
4890 ssh2_pkt_addstring(proto);
4891 ssh2_pkt_addstring(data);
4892 ssh2_pkt_adduint32(0); /* screen number */
4893 ssh2_pkt_send();
4894
4895 do {
4896 crWaitUntilV(ispkt);
4897 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4898 unsigned i = ssh2_pkt_getuint32();
4899 struct ssh_channel *c;
4900 c = find234(ssh_channels, &i, ssh_channelfind);
4901 if (!c)
4902 continue; /* nonexistent channel */
5471d09a 4903 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4904 }
4905 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4906
4907 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4908 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4909 bombout(("Unexpected response to X11 forwarding request:"
4910 " packet type %d", pktin.type));
32874aea 4911 crReturnV;
4912 }
4913 logevent("X11 forwarding refused");
4914 } else {
4915 logevent("X11 forwarding enabled");
783415f8 4916 ssh_X11_fwd_enabled = TRUE;
32874aea 4917 }
783415f8 4918 }
4919
4920 /*
bc240b21 4921 * Enable port forwardings.
4922 */
4923 {
4924 static char *e; /* preserve across crReturn */
4925 char type;
4926 int n;
a4fc0d74 4927 int sport,dport,sserv,dserv;
bc240b21 4928 char sports[256], dports[256], host[256];
4929 char buf[1024];
a4fc0d74 4930 struct servent *se;
bc240b21 4931
4932 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4933 /* Add port forwardings. */
4934 e = cfg.portfwd;
4935 while (*e) {
4936 type = *e++;
4937 n = 0;
4938 while (*e && *e != '\t')
4939 sports[n++] = *e++;
4940 sports[n] = 0;
4941 if (*e == '\t')
4942 e++;
4943 n = 0;
4944 while (*e && *e != ':')
4945 host[n++] = *e++;
4946 host[n] = 0;
4947 if (*e == ':')
4948 e++;
4949 n = 0;
4950 while (*e)
4951 dports[n++] = *e++;
4952 dports[n] = 0;
4953 e++;
4954 dport = atoi(dports);
a4fc0d74 4955 dserv = 0;
4956 if (dport == 0) {
4957 dserv = 1;
4958 se = getservbyname(dports, NULL);
4959 if (se != NULL) {
4960 dport = ntohs(se->s_port);
4961 } else {
4962 sprintf(buf,
4963 "Service lookup failed for destination port \"%s\"",
4964 dports);
4965 logevent(buf);
4966 }
4967 }
bc240b21 4968 sport = atoi(sports);
a4fc0d74 4969 sserv = 0;
4970 if (sport == 0) {
4971 sserv = 1;
4972 se = getservbyname(sports, NULL);
4973 if (se != NULL) {
4974 sport = ntohs(se->s_port);
4975 } else {
4976 sprintf(buf,
4977 "Service lookup failed for source port \"%s\"",
4978 sports);
4979 logevent(buf);
4980 }
4981 }
bc240b21 4982 if (sport && dport) {
4983 if (type == 'L') {
4984 pfd_addforward(host, dport, sport);
a4fc0d74 4985 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4986 " %s:%.*s%.*s%d%.*s",
4987 sserv ? strlen(sports) : 0, sports,
4988 sserv, "(", sport, sserv, ")",
4989 host,
4990 dserv ? strlen(dports) : 0, dports,
4991 dserv, "(", dport, dserv, ")");
bc240b21 4992 logevent(buf);
4993 } else {
4994 struct ssh_rportfwd *pf;
4995 pf = smalloc(sizeof(*pf));
4996 strcpy(pf->dhost, host);
4997 pf->dport = dport;
4998 pf->sport = sport;
4999 if (add234(ssh_rportfwds, pf) != pf) {
5000 sprintf(buf,
95bc8819 5001 "Duplicate remote port forwarding to %s:%d",
bc240b21 5002 host, dport);
5003 logevent(buf);
5004 sfree(pf);
5005 } else {
a4fc0d74 5006 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5007 " forward to %s:%.*s%.*s%d%.*s",
5008 sserv ? strlen(sports) : 0, sports,
5009 sserv, "(", sport, sserv, ")",
5010 host,
5011 dserv ? strlen(dports) : 0, dports,
5012 dserv, "(", dport, dserv, ")");
bc240b21 5013 logevent(buf);
5014 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5015 ssh2_pkt_addstring("tcpip-forward");
5016 ssh2_pkt_addbool(1);/* want reply */
beefa433 5017 if (cfg.rport_acceptall)
5018 ssh2_pkt_addstring("0.0.0.0");
5019 else
5020 ssh2_pkt_addstring("127.0.0.1");
bc240b21 5021 ssh2_pkt_adduint32(sport);
5022 ssh2_pkt_send();
5023
5024 do {
5025 crWaitUntilV(ispkt);
5026 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5027 unsigned i = ssh2_pkt_getuint32();
5028 struct ssh_channel *c;
5029 c = find234(ssh_channels, &i, ssh_channelfind);
5030 if (!c)
5031 continue;/* nonexistent channel */
5471d09a 5032 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 5033 }
5034 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5035
5036 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5037 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5038 bombout(("Unexpected response to port "
5039 "forwarding request: packet type %d",
5040 pktin.type));
bc240b21 5041 crReturnV;
5042 }
5043 logevent("Server refused this port forwarding");
5044 } else {
5045 logevent("Remote port forwarding enabled");
5046 }
5047 }
5048 }
5049 }
5050 }
5051 }
5052
5053 /*
36c2a3e9 5054 * Potentially enable agent forwarding.
5055 */
5056 if (cfg.agentfwd && agent_exists()) {
32874aea 5057 logevent("Requesting OpenSSH-style agent forwarding");
5058 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5059 ssh2_pkt_adduint32(mainchan->remoteid);
5060 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5061 ssh2_pkt_addbool(1); /* want reply */
5062 ssh2_pkt_send();
5063
5064 do {
5065 crWaitUntilV(ispkt);
5066 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5067 unsigned i = ssh2_pkt_getuint32();
5068 struct ssh_channel *c;
5069 c = find234(ssh_channels, &i, ssh_channelfind);
5070 if (!c)
5071 continue; /* nonexistent channel */
5471d09a 5072 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5073 }
5074 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5075
5076 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5077 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5078 bombout(("Unexpected response to agent forwarding request:"
5079 " packet type %d", pktin.type));
32874aea 5080 crReturnV;
5081 }
5082 logevent("Agent forwarding refused");
5083 } else {
5084 logevent("Agent forwarding enabled");
36c2a3e9 5085 ssh_agentfwd_enabled = TRUE;
32874aea 5086 }
36c2a3e9 5087 }
5088
5089 /*
7cca0d81 5090 * Now allocate a pty for the session.
5091 */
67779be7 5092 if (!cfg.nopty) {
32874aea 5093 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5094 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5095 ssh2_pkt_addstring("pty-req");
5096 ssh2_pkt_addbool(1); /* want reply */
5097 ssh2_pkt_addstring(cfg.termtype);
5098 ssh2_pkt_adduint32(cols);
5099 ssh2_pkt_adduint32(rows);
5100 ssh2_pkt_adduint32(0); /* pixel width */
5101 ssh2_pkt_adduint32(0); /* pixel height */
5102 ssh2_pkt_addstring_start();
5103 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5104 ssh2_pkt_send();
5105 ssh_state = SSH_STATE_INTERMED;
5106
5107 do {
5108 crWaitUntilV(ispkt);
5109 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5110 unsigned i = ssh2_pkt_getuint32();
5111 struct ssh_channel *c;
5112 c = find234(ssh_channels, &i, ssh_channelfind);
5113 if (!c)
5114 continue; /* nonexistent channel */
5471d09a 5115 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5116 }
5117 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5118
5119 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5120 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5121 bombout(("Unexpected response to pty request:"
5122 " packet type %d", pktin.type));
32874aea 5123 crReturnV;
5124 }
5125 c_write_str("Server refused to allocate pty\r\n");
5126 ssh_editing = ssh_echoing = 1;
5127 } else {
5128 logevent("Allocated pty");
5129 }
0965bee0 5130 } else {
32874aea 5131 ssh_editing = ssh_echoing = 1;
7cca0d81 5132 }
5133
5134 /*
fd5e5847 5135 * Start a shell or a remote command. We may have to attempt
5136 * this twice if the config data has provided a second choice
5137 * of command.
7cca0d81 5138 */
fd5e5847 5139 while (1) {
5140 int subsys;
5141 char *cmd;
5142
5143 if (ssh_fallback_cmd) {
5144 subsys = cfg.ssh_subsys2;
5145 cmd = cfg.remote_cmd_ptr2;
5146 } else {
5147 subsys = cfg.ssh_subsys;
5148 cmd = cfg.remote_cmd_ptr;
5149 }
5150
5151 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5152 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5153 if (subsys) {
5154 ssh2_pkt_addstring("subsystem");
5155 ssh2_pkt_addbool(1); /* want reply */
5156 ssh2_pkt_addstring(cmd);
5157 } else if (*cmd) {
5158 ssh2_pkt_addstring("exec");
5159 ssh2_pkt_addbool(1); /* want reply */
5160 ssh2_pkt_addstring(cmd);
5161 } else {
5162 ssh2_pkt_addstring("shell");
5163 ssh2_pkt_addbool(1); /* want reply */
32874aea 5164 }
fd5e5847 5165 ssh2_pkt_send();
5166 do {
5167 crWaitUntilV(ispkt);
5168 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5169 unsigned i = ssh2_pkt_getuint32();
5170 struct ssh_channel *c;
5171 c = find234(ssh_channels, &i, ssh_channelfind);
5172 if (!c)
5173 continue; /* nonexistent channel */
5174 c->v.v2.remwindow += ssh2_pkt_getuint32();
5175 }
5176 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5177 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5178 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5179 bombout(("Unexpected response to shell/command request:"
5180 " packet type %d", pktin.type));
fd5e5847 5181 crReturnV;
5182 }
5183 /*
5184 * We failed to start the command. If this is the
5185 * fallback command, we really are finished; if it's
5186 * not, and if the fallback command exists, try falling
5187 * back to it before complaining.
5188 */
5189 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5190 logevent("Primary command failed; attempting fallback");
5191 ssh_fallback_cmd = TRUE;
5192 continue;
5193 }
5194 bombout(("Server refused to start a shell/command"));
32874aea 5195 crReturnV;
fd5e5847 5196 } else {
5197 logevent("Started a shell/command");
32874aea 5198 }
fd5e5847 5199 break;
7cca0d81 5200 }
5201
6e48c3fe 5202 ssh_state = SSH_STATE_SESSION;
5203 if (size_needed)
5204 ssh_size();
3687d221 5205 if (eof_needed)
32874aea 5206 ssh_special(TS_EOF);
6e48c3fe 5207
7cca0d81 5208 /*
5209 * Transfer data!
5210 */
760e88b2 5211 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 5212 ssh_send_ok = 1;
7cca0d81 5213 while (1) {
32874aea 5214 static int try_send;
e5574168 5215 crReturnV;
32874aea 5216 try_send = FALSE;
7cca0d81 5217 if (ispkt) {
5218 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 5219 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5220 char *data;
5221 int length;
5222 unsigned i = ssh2_pkt_getuint32();
5223 struct ssh_channel *c;
5224 c = find234(ssh_channels, &i, ssh_channelfind);
5225 if (!c)
5226 continue; /* nonexistent channel */
5227 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5228 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5229 continue; /* extended but not stderr */
5230 ssh2_pkt_getstring(&data, &length);
5231 if (data) {
5471d09a 5232 int bufsize;
5233 c->v.v2.locwindow -= length;
32874aea 5234 switch (c->type) {
5235 case CHAN_MAINSESSION:
5471d09a 5236 bufsize =
5237 from_backend(pktin.type ==
5238 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5239 data, length);
32874aea 5240 break;
5241 case CHAN_X11:
5471d09a 5242 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5243 break;
d74d141c 5244 case CHAN_SOCKDATA:
5471d09a 5245 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5246 break;
36c2a3e9 5247 case CHAN_AGENT:
32874aea 5248 while (length > 0) {
5249 if (c->u.a.lensofar < 4) {
5250 int l = min(4 - c->u.a.lensofar, length);
5251 memcpy(c->u.a.msglen + c->u.a.lensofar,
5252 data, l);
5253 data += l;
5254 length -= l;
5255 c->u.a.lensofar += l;
5256 }
5257 if (c->u.a.lensofar == 4) {
5258 c->u.a.totallen =
5259 4 + GET_32BIT(c->u.a.msglen);
5260 c->u.a.message = smalloc(c->u.a.totallen);
5261 memcpy(c->u.a.message, c->u.a.msglen, 4);
5262 }
5263 if (c->u.a.lensofar >= 4 && length > 0) {
5264 int l =
5265 min(c->u.a.totallen - c->u.a.lensofar,
5266 length);
5267 memcpy(c->u.a.message + c->u.a.lensofar,
5268 data, l);
5269 data += l;
5270 length -= l;
5271 c->u.a.lensofar += l;
5272 }
5273 if (c->u.a.lensofar == c->u.a.totallen) {
5274 void *reply, *sentreply;
5275 int replylen;
5276 agent_query(c->u.a.message,
5277 c->u.a.totallen, &reply,
5278 &replylen);
5279 if (reply)
5280 sentreply = reply;
5281 else {
5282 /* Fake SSH_AGENT_FAILURE. */
5283 sentreply = "\0\0\0\1\5";
5284 replylen = 5;
5285 }
5286 ssh2_add_channel_data(c, sentreply,
5287 replylen);
36c2a3e9 5288 try_send = TRUE;
32874aea 5289 if (reply)
5290 sfree(reply);
5291 sfree(c->u.a.message);
5292 c->u.a.lensofar = 0;
5293 }
5294 }
5471d09a 5295 bufsize = 0;
32874aea 5296 break;
5297 }
5298 /*
5471d09a 5299 * If we are not buffering too much data,
5300 * enlarge the window again at the remote side.
32874aea 5301 */
5471d09a 5302 if (bufsize < OUR_V2_WINSIZE)
5303 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5304 }
7cca0d81 5305 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 5306 ssh_state = SSH_STATE_CLOSED;
d211621f 5307 logevent("Received disconnect message");
32874aea 5308 crReturnV;
d211621f 5309 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 5310 unsigned i = ssh2_pkt_getuint32();
5311 struct ssh_channel *c;
5312
5313 c = find234(ssh_channels, &i, ssh_channelfind);
5314 if (!c)
5315 continue; /* nonexistent channel */
5316
5317 if (c->type == CHAN_X11) {
5318 /*
5319 * Remote EOF on an X11 channel means we should
5320 * wrap up and close the channel ourselves.
5321 */
5322 x11_close(c->u.x11.s);
5323 sshfwd_close(c);
5324 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5325 sshfwd_close(c);
d74d141c 5326 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5327 pfd_close(c->u.pfd.s);
5328 sshfwd_close(c);
36c2a3e9 5329 }
d211621f 5330 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 5331 unsigned i = ssh2_pkt_getuint32();
5332 struct ssh_channel *c;
5333
5334 c = find234(ssh_channels, &i, ssh_channelfind);
5335 if (!c)
5336 continue; /* nonexistent channel */
32874aea 5337 /* Do pre-close processing on the channel. */
5338 switch (c->type) {
5339 case CHAN_MAINSESSION:
5340 break; /* nothing to see here, move along */
5341 case CHAN_X11:
92f157bd 5342 if (c->u.x11.s != NULL)
5343 x11_close(c->u.x11.s);
5344 sshfwd_close(c);
32874aea 5345 break;
5346 case CHAN_AGENT:
92f157bd 5347 sshfwd_close(c);
32874aea 5348 break;
d74d141c 5349 case CHAN_SOCKDATA:
92f157bd 5350 if (c->u.pfd.s != NULL)
5351 pfd_close(c->u.pfd.s);
5352 sshfwd_close(c);
bc240b21 5353 break;
32874aea 5354 }
92f157bd 5355 if (c->closes == 0) {
5356 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5357 ssh2_pkt_adduint32(c->remoteid);
5358 ssh2_pkt_send();
5359 }
32874aea 5360 del234(ssh_channels, c);
5471d09a 5361 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5362 sfree(c);
5363
5364 /*
5365 * See if that was the last channel left open.
5366 */
5367 if (count234(ssh_channels) == 0) {
ca2914d1 5368#if 0
5369 /*
5370 * We used to send SSH_MSG_DISCONNECT here,
5371 * because I'd believed that _every_ conforming
5372 * SSH2 connection had to end with a disconnect
5373 * being sent by at least one side; apparently
5374 * I was wrong and it's perfectly OK to
5375 * unceremoniously slam the connection shut
5376 * when you're done, and indeed OpenSSH feels
5377 * this is more polite than sending a
5378 * DISCONNECT. So now we don't.
5379 */
32874aea 5380 logevent("All channels closed. Disconnecting");
5381 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5382 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5383 ssh2_pkt_addstring("All open channels closed");
5384 ssh2_pkt_addstring("en"); /* language tag */
5385 ssh2_pkt_send();
ca2914d1 5386#endif
32874aea 5387 ssh_state = SSH_STATE_CLOSED;
5388 crReturnV;
5389 }
5390 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 5391 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 5392 unsigned i = ssh2_pkt_getuint32();
5393 struct ssh_channel *c;
5394 c = find234(ssh_channels, &i, ssh_channelfind);
5395 if (!c)
5396 continue; /* nonexistent channel */
5471d09a 5397 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5398 try_send = TRUE;
bc240b21 5399 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5400 unsigned i = ssh2_pkt_getuint32();
5401 struct ssh_channel *c;
5402 c = find234(ssh_channels, &i, ssh_channelfind);
5403 if (!c)
5404 continue; /* nonexistent channel */
5405 if (c->type != CHAN_SOCKDATA_DORMANT)
5406 continue; /* dunno why they're confirming this */
5407 c->remoteid = ssh2_pkt_getuint32();
5408 c->type = CHAN_SOCKDATA;
5471d09a 5409 c->v.v2.remwindow = ssh2_pkt_getuint32();
5410 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4ed34d25 5411 if (c->u.pfd.s)
5412 pfd_confirm(c->u.pfd.s);
5413 if (c->closes) {
5414 /*
5415 * We have a pending close on this channel,
5416 * which we decided on before the server acked
5417 * the channel open. So now we know the
5418 * remoteid, we can close it again.
5419 */
5420 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5421 ssh2_pkt_adduint32(c->remoteid);
5422 ssh2_pkt_send();
5423 }
724cface 5424 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5425 unsigned i = ssh2_pkt_getuint32();
5426 struct ssh_channel *c;
5427 c = find234(ssh_channels, &i, ssh_channelfind);
5428 if (!c)
5429 continue; /* nonexistent channel */
5430 if (c->type != CHAN_SOCKDATA_DORMANT)
5431 continue; /* dunno why they're failing this */
5432
5433 logevent("Forwarded connection refused by server");
5434
5435 pfd_close(c->u.pfd.s);
5436
5437 del234(ssh_channels, c);
5438 sfree(c);
ebb0a590 5439 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5440 unsigned localid;
5441 char *type;
5442 int typelen, want_reply;
5443 struct ssh_channel *c;
5444
5445 localid = ssh2_pkt_getuint32();
5446 ssh2_pkt_getstring(&type, &typelen);
5447 want_reply = ssh2_pkt_getbool();
5448
5449 /*
5450 * First, check that the channel exists. Otherwise,
5451 * we can instantly disconnect with a rude message.
5452 */
5453 c = find234(ssh_channels, &localid, ssh_channelfind);
5454 if (!c) {
5455 char buf[80];
5456 sprintf(buf, "Received channel request for nonexistent"
5457 " channel %d", localid);
5458 logevent(buf);
5459 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5460 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5461 ssh2_pkt_addstring(buf);
5462 ssh2_pkt_addstring("en"); /* language tag */
5463 ssh2_pkt_send();
247308b5 5464 connection_fatal("%s", buf);
ebb0a590 5465 ssh_state = SSH_STATE_CLOSED;
5466 crReturnV;
5467 }
5468
5469 /*
d8d6c7e5 5470 * Having got the channel number, we now look at
5471 * the request type string to see if it's something
5472 * we recognise.
ebb0a590 5473 */
d8d6c7e5 5474 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5475 c == mainchan) {
5476 /* We recognise "exit-status" on the primary channel. */
5477 char buf[100];
5478 ssh_exitcode = ssh2_pkt_getuint32();
5479 sprintf(buf, "Server sent command exit status %d",
5480 ssh_exitcode);
5481 logevent(buf);
5482 if (want_reply) {
5483 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5484 ssh2_pkt_adduint32(c->remoteid);
5485 ssh2_pkt_send();
5486 }
5487 } else {
5488 /*
5489 * This is a channel request we don't know
5490 * about, so we now either ignore the request
5491 * or respond with CHANNEL_FAILURE, depending
5492 * on want_reply.
5493 */
5494 if (want_reply) {
5495 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5496 ssh2_pkt_adduint32(c->remoteid);
5497 ssh2_pkt_send();
5498 }
ebb0a590 5499 }
697d4856 5500 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5501 char *type;
5502 int typelen, want_reply;
5503
5504 ssh2_pkt_getstring(&type, &typelen);
5505 want_reply = ssh2_pkt_getbool();
5506
5507 /*
5508 * We currently don't support any global requests
5509 * at all, so we either ignore the request or
5510 * respond with REQUEST_FAILURE, depending on
5511 * want_reply.
5512 */
5513 if (want_reply) {
5514 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5515 ssh2_pkt_send();
5516 }
783415f8 5517 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5518 char *type;
5519 int typelen;
5520 char *error = NULL;
5521 struct ssh_channel *c;
bc240b21 5522 unsigned remid, winsize, pktsize;
32874aea 5523 ssh2_pkt_getstring(&type, &typelen);
5524 c = smalloc(sizeof(struct ssh_channel));
5525
bc240b21 5526 remid = ssh2_pkt_getuint32();
5527 winsize = ssh2_pkt_getuint32();
5528 pktsize = ssh2_pkt_getuint32();
5529
32874aea 5530 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5531 if (!ssh_X11_fwd_enabled)
5532 error = "X11 forwarding is not enabled";
5533 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5534 NULL) {
5535 error = "Unable to open an X11 connection";
5536 } else {
5537 c->type = CHAN_X11;
5538 }
bc240b21 5539 } else if (typelen == 15 &&
5540 !memcmp(type, "forwarded-tcpip", 15)) {
5541 struct ssh_rportfwd pf, *realpf;
5542 char *dummy;
5543 int dummylen;
5544 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5545 pf.sport = ssh2_pkt_getuint32();
5546 realpf = find234(ssh_rportfwds, &pf, NULL);
5547 if (realpf == NULL) {
5548 error = "Remote port is not recognised";
5549 } else {
5550 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5551 realpf->dport, c);
5552 char buf[1024];
5553 sprintf(buf, "Received remote port open request for %s:%d",
5554 realpf->dhost, realpf->dport);
5555 logevent(buf);
5556 if (e != NULL) {
5557 sprintf(buf, "Port open failed: %s", e);
5558 logevent(buf);
5559 error = "Port open failed";
5560 } else {
5561 logevent("Forwarded port opened successfully");
5562 c->type = CHAN_SOCKDATA;
5563 }
5564 }
32874aea 5565 } else if (typelen == 22 &&
36c2a3e9 5566 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5567 if (!ssh_agentfwd_enabled)
5568 error = "Agent forwarding is not enabled";
36c2a3e9 5569 else {
32874aea 5570 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5571 c->u.a.lensofar = 0;
32874aea 5572 }
5573 } else {
5574 error = "Unsupported channel type requested";
5575 }
5576
bc240b21 5577 c->remoteid = remid;
32874aea 5578 if (error) {
5579 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5580 ssh2_pkt_adduint32(c->remoteid);
5581 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5582 ssh2_pkt_addstring(error);
5583 ssh2_pkt_addstring("en"); /* language tag */
5584 ssh2_pkt_send();
5585 sfree(c);
5586 } else {
5587 c->localid = alloc_channel_id();
5588 c->closes = 0;
5471d09a 5589 c->v.v2.locwindow = OUR_V2_WINSIZE;
5590 c->v.v2.remwindow = winsize;
5591 c->v.v2.remmaxpkt = pktsize;
5592 bufchain_init(&c->v.v2.outbuffer);
32874aea 5593 add234(ssh_channels, c);
5594 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5595 ssh2_pkt_adduint32(c->remoteid);
5596 ssh2_pkt_adduint32(c->localid);
5471d09a 5597 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5598 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5599 ssh2_pkt_send();
5600 }
7cca0d81 5601 } else {
8d5de777 5602 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5603 crReturnV;
7cca0d81 5604 }
5605 } else {
32874aea 5606 /*
5607 * We have spare data. Add it to the channel buffer.
5608 */
5609 ssh2_add_channel_data(mainchan, in, inlen);
5610 try_send = TRUE;
5611 }
5612 if (try_send) {
5613 int i;
5614 struct ssh_channel *c;
5615 /*
5616 * Try to send data on all channels if we can.
5617 */
5471d09a 5618 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5619 int bufsize = ssh2_try_send(c);
5620 if (bufsize == 0) {
5621 switch (c->type) {
5622 case CHAN_MAINSESSION:
5623 /* stdin need not receive an unthrottle
5624 * notification since it will be polled */
5625 break;
5626 case CHAN_X11:
5627 x11_unthrottle(c->u.x11.s);
5628 break;
5629 case CHAN_AGENT:
5630 /* agent sockets are request/response and need no
5631 * buffer management */
5632 break;
5633 case CHAN_SOCKDATA:
5634 pfd_unthrottle(c->u.pfd.s);
5635 break;
5636 }
5637 }
5638 }
7cca0d81 5639 }
e5574168 5640 }
5641
5642 crFinishV;
5643}
5644
5645/*
7cca0d81 5646 * Handle the top-level SSH2 protocol.
5647 */
5648static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5649{
5650 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5651 return;
7cca0d81 5652 do_ssh2_authconn(in, inlen, ispkt);
5653}
5654
5655/*
8df7a775 5656 * Called to set up the connection.
374330e2 5657 *
5658 * Returns an error message, or NULL on success.
374330e2 5659 */
2184a5d9 5660static char *ssh_init(char *host, int port, char **realhost, int nodelay)
32874aea 5661{
fb09bf1c 5662 char *p;
32874aea 5663
8f203108 5664#ifdef MSCRYPTOAPI
32874aea 5665 if (crypto_startup() == 0)
8f203108 5666 return "Microsoft high encryption pack not installed!";
5667#endif
374330e2 5668
8df7a775 5669 ssh_send_ok = 0;
0965bee0 5670 ssh_editing = 0;
5671 ssh_echoing = 0;
5471d09a 5672 ssh1_throttle_count = 0;
5673 ssh_overall_bufsize = 0;
fd5e5847 5674 ssh_fallback_cmd = 0;
8df7a775 5675
2184a5d9 5676 p = connect_to_host(host, port, realhost, nodelay);
fb09bf1c 5677 if (p != NULL)
5678 return p;
374330e2 5679
374330e2 5680 return NULL;
5681}
5682
5683/*
374330e2 5684 * Called to send data down the Telnet connection.
5685 */
5471d09a 5686static int ssh_send(char *buf, int len)
32874aea 5687{
f78051a1 5688 if (s == NULL || ssh_protocol == NULL)
5471d09a 5689 return 0;
374330e2 5690
5691 ssh_protocol(buf, len, 0);
5471d09a 5692
5693 return ssh_sendbuffer();
5694}
5695
5696/*
5697 * Called to query the current amount of buffered stdin data.
5698 */
5699static int ssh_sendbuffer(void)
5700{
5701 int override_value;
5702
5703 if (s == NULL || ssh_protocol == NULL)
5704 return 0;
5705
5706 /*
5707 * If the SSH socket itself has backed up, add the total backup
5708 * size on that to any individual buffer on the stdin channel.
5709 */
5710 override_value = 0;
5711 if (ssh_throttled_all)
5712 override_value = ssh_overall_bufsize;
5713
5714 if (ssh_version == 1) {
5715 return override_value;
5716 } else if (ssh_version == 2) {
5717 if (!mainchan || mainchan->closes > 0)
5718 return override_value;
5719 else
5720 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5721 }
5722
5723 return 0;
374330e2 5724}
5725
5726/*
6e48c3fe 5727 * Called to set the size of the window from SSH's POV.
374330e2 5728 */
32874aea 5729static void ssh_size(void)
5730{
374330e2 5731 switch (ssh_state) {
5732 case SSH_STATE_BEFORE_SIZE:
3687d221 5733 case SSH_STATE_PREPACKET:
21248260 5734 case SSH_STATE_CLOSED:
374330e2 5735 break; /* do nothing */
5736 case SSH_STATE_INTERMED:
5737 size_needed = TRUE; /* buffer for later */
5738 break;
5739 case SSH_STATE_SESSION:
32874aea 5740 if (!cfg.nopty) {
5741 if (ssh_version == 1) {
5742 send_packet(SSH1_CMSG_WINDOW_SIZE,
5743 PKT_INT, rows, PKT_INT, cols,
5744 PKT_INT, 0, PKT_INT, 0, PKT_END);
5745 } else {
5746 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5747 ssh2_pkt_adduint32(mainchan->remoteid);
5748 ssh2_pkt_addstring("window-change");
5749 ssh2_pkt_addbool(0);
5750 ssh2_pkt_adduint32(cols);
5751 ssh2_pkt_adduint32(rows);
5752 ssh2_pkt_adduint32(0);
5753 ssh2_pkt_adduint32(0);
5754 ssh2_pkt_send();
5755 }
5756 }
5757 break;
374330e2 5758 }
5759}
5760
5761/*
6abbf9e3 5762 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5763 * can send an EOF and collect resulting output (e.g. `plink
5764 * hostname sort').
374330e2 5765 */
32874aea 5766static void ssh_special(Telnet_Special code)
5767{
6abbf9e3 5768 if (code == TS_EOF) {
32874aea 5769 if (ssh_state != SSH_STATE_SESSION) {
5770 /*
5771 * Buffer the EOF in case we are pre-SESSION, so we can
5772 * send it as soon as we reach SESSION.
5773 */
5774 if (code == TS_EOF)
5775 eof_needed = TRUE;
5776 return;
5777 }
5778 if (ssh_version == 1) {
5779 send_packet(SSH1_CMSG_EOF, PKT_END);
5780 } else {
5781 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5782 ssh2_pkt_adduint32(mainchan->remoteid);
5783 ssh2_pkt_send();
5784 }
5785 logevent("Sent EOF message");
ec55b220 5786 } else if (code == TS_PING) {
32874aea 5787 if (ssh_state == SSH_STATE_CLOSED
5788 || ssh_state == SSH_STATE_PREPACKET) return;
5789 if (ssh_version == 1) {
5790 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5791 } else {
5792 ssh2_pkt_init(SSH2_MSG_IGNORE);
5793 ssh2_pkt_addstring_start();
5794 ssh2_pkt_send();
5795 }
6abbf9e3 5796 } else {
32874aea 5797 /* do nothing */
6abbf9e3 5798 }
374330e2 5799}
5800
d74d141c 5801void *new_sock_channel(Socket s)
5802{
5803 struct ssh_channel *c;
5804 c = smalloc(sizeof(struct ssh_channel));
5805
5806 if (c) {
bc240b21 5807 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5808 c->localid = alloc_channel_id();
5809 c->closes = 0;
bc240b21 5810 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5811 c->u.pfd.s = s;
013dd8c0 5812 bufchain_init(&c->v.v2.outbuffer);
d74d141c 5813 add234(ssh_channels, c);
5814 }
5815 return c;
5816}
5817
5471d09a 5818/*
5819 * This is called when stdout/stderr (the entity to which
5820 * from_backend sends data) manages to clear some backlog.
5821 */
5822void ssh_unthrottle(int bufsize)
5823{
5824 if (ssh_version == 1) {
90347b95 5825 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5826 ssh1_stdout_throttling = 0;
5827 ssh1_throttle(-1);
5828 }
5829 } else {
5830 if (mainchan && mainchan->closes == 0)
5831 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5832 }
5833}
5834
d74d141c 5835void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5836{
5837 struct ssh_channel *c = (struct ssh_channel *)channel;
5838 char buf[1024];
5839
5840 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5841 logevent(buf);
5842
bc240b21 5843 if (ssh_version == 1) {
5844 send_packet(SSH1_MSG_PORT_OPEN,
5845 PKT_INT, c->localid,
5846 PKT_STR, hostname,
5847 PKT_INT, port,
5848 //PKT_STR, <org:orgport>,
5849 PKT_END);
5850 } else {
5851 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5852 ssh2_pkt_addstring("direct-tcpip");
5853 ssh2_pkt_adduint32(c->localid);
5471d09a 5854 c->v.v2.locwindow = OUR_V2_WINSIZE;
5855 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5856 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5857 ssh2_pkt_addstring(hostname);
5858 ssh2_pkt_adduint32(port);
5859 /*
5860 * We make up values for the originator data; partly it's
5861 * too much hassle to keep track, and partly I'm not
5862 * convinced the server should be told details like that
5863 * about my local network configuration.
5864 */
5865 ssh2_pkt_addstring("client-side-connection");
5866 ssh2_pkt_adduint32(0);
5867 ssh2_pkt_send();
5868 }
d74d141c 5869}
5870
5871
32874aea 5872static Socket ssh_socket(void)
5873{
5874 return s;
5875}
8ccc75b0 5876
32874aea 5877static int ssh_sendok(void)
5878{
5879 return ssh_send_ok;
5880}
fb09bf1c 5881
32874aea 5882static int ssh_ldisc(int option)
5883{
5884 if (option == LD_ECHO)
5885 return ssh_echoing;
5886 if (option == LD_EDIT)
5887 return ssh_editing;
0965bee0 5888 return FALSE;
5889}
5890
d8d6c7e5 5891static int ssh_return_exitcode(void)
5892{
5893 return ssh_exitcode;
5894}
5895
374330e2 5896Backend ssh_backend = {
5897 ssh_init,
374330e2 5898 ssh_send,
5471d09a 5899 ssh_sendbuffer,
374330e2 5900 ssh_size,
4017be6d 5901 ssh_special,
8ccc75b0 5902 ssh_socket,
d8d6c7e5 5903 ssh_return_exitcode,
97db3be4 5904 ssh_sendok,
0965bee0 5905 ssh_ldisc,
5471d09a 5906 ssh_unthrottle,
97db3be4 5907 22
bc240b21 5908};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator