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