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Fix some compiler warnings.
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 21
247308b5 22/* logevent, only printf-formatted. */
23void logeventf(char *fmt, ...)
24{
25 va_list ap;
26 char stuff[200];
27
28 va_start(ap, fmt);
29 vsprintf(stuff, fmt, ap);
30 va_end(ap);
31 logevent(stuff);
32}
33
51470298 34#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
35 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
247308b5 36 logeventf msg, connection_fatal msg )
8d5de777 37
32874aea 38#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41#define SSH1_CMSG_USER 4 /* 0x4 */
42#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50#define SSH1_SMSG_SUCCESS 14 /* 0xe */
51#define SSH1_SMSG_FAILURE 15 /* 0xf */
52#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55#define SSH1_CMSG_EOF 19 /* 0x13 */
56#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67#define SSH1_MSG_IGNORE 32 /* 0x20 */
68#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71#define SSH1_MSG_DEBUG 36 /* 0x24 */
72#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
79
80#define SSH1_AUTH_TIS 5 /* 0x5 */
81#define SSH1_AUTH_CCARD 16 /* 0x10 */
82
83#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 84/* Mask for protoflags we will echo back to server if seen */
32874aea 85#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
86
87#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88#define SSH2_MSG_IGNORE 2 /* 0x2 */
89#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90#define SSH2_MSG_DEBUG 4 /* 0x4 */
91#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93#define SSH2_MSG_KEXINIT 20 /* 0x14 */
94#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 107#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 109#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
123
00db133f 124/*
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
127 */
128#define SSH2_PKTCTX_DHGROUP1 0x0001
129#define SSH2_PKTCTX_DHGEX 0x0002
130#define SSH2_PKTCTX_PUBLICKEY 0x0010
131#define SSH2_PKTCTX_PASSWORD 0x0020
132#define SSH2_PKTCTX_KBDINTER 0x0040
133#define SSH2_PKTCTX_AUTH_MASK 0x00F0
134
32874aea 135#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 150
151static const char *const ssh2_disconnect_reasons[] = {
152 NULL,
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
168};
9005f3ba 169
32874aea 170#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 174
32874aea 175#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 176
7d503c31 177/*
178 * Various remote-bug flags.
179 */
180#define BUG_CHOKES_ON_SSH1_IGNORE 1
181#define BUG_SSH2_HMAC 2
bd358db1 182#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 183#define BUG_CHOKES_ON_RSA 8
1dd353b5 184#define BUG_SSH2_RSA_PADDING 16
088bde77 185#define BUG_SSH2_DERIVEKEY 32
8e975795 186#define BUG_SSH2_DH_GEX 64
bd358db1 187
00db133f 188#define translate(x) if (type == x) return #x
51470298 189#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
00db133f 190char *ssh1_pkt_type(int type)
191{
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
233 return "unknown";
234}
51470298 235char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 236{
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
273 return "unknown";
274}
275#undef translate
276#undef translatec
7d503c31 277
fb09bf1c 278#define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
283
284#define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
289
7cca0d81 290enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 291
374330e2 292/* Coroutine mechanics for the sillier bits of the code */
51470298 293#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
294#define crState(t) \
295 struct t *s; \
296 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
297 s = ssh->t;
298#define crFinish(z) } *crLine = 0; return (z); }
299#define crFinishV } *crLine = 0; return; }
374330e2 300#define crReturn(z) \
301 do {\
51470298 302 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 303 } while (0)
304#define crReturnV \
305 do {\
51470298 306 *crLine=__LINE__; return; case __LINE__:;\
374330e2 307 } while (0)
51470298 308#define crStop(z) do{ *crLine = 0; return (z); }while(0)
309#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 310#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 311#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 312
51470298 313typedef struct ssh_tag *Ssh;
314
32874aea 315extern char *x11_init(Socket *, char *, void *);
316extern void x11_close(Socket);
5471d09a 317extern int x11_send(Socket, char *, int);
9c964e85 318extern void x11_invent_auth(char *, int, char *, int);
5471d09a 319extern void x11_unthrottle(Socket s);
320extern void x11_override_throttle(Socket s, int enable);
9c964e85 321
d74d141c 322extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
323extern char *pfd_addforward(char *desthost, int destport, int port);
324extern void pfd_close(Socket s);
5471d09a 325extern int pfd_send(Socket s, char *data, int len);
d74d141c 326extern void pfd_confirm(Socket s);
5471d09a 327extern void pfd_unthrottle(Socket s);
328extern void pfd_override_throttle(Socket s, int enable);
329
51470298 330static void ssh2_pkt_init(Ssh, int pkt_type);
331static void ssh2_pkt_addbool(Ssh, unsigned char value);
332static void ssh2_pkt_adduint32(Ssh, unsigned long value);
333static void ssh2_pkt_addstring_start(Ssh);
334static void ssh2_pkt_addstring_str(Ssh, char *data);
335static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
336static void ssh2_pkt_addstring(Ssh, char *data);
3d63ca2e 337static char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 338static void ssh2_pkt_addmp(Ssh, Bignum b);
339static int ssh2_pkt_construct(Ssh);
340static void ssh2_pkt_send(Ssh);
3d63ca2e 341
5471d09a 342/*
343 * Buffer management constants. There are several of these for
344 * various different purposes:
345 *
346 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
347 * on a local data stream before we throttle the whole SSH
348 * connection (in SSH1 only). Throttling the whole connection is
349 * pretty drastic so we set this high in the hope it won't
350 * happen very often.
351 *
352 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
353 * on the SSH connection itself before we defensively throttle
354 * _all_ local data streams. This is pretty drastic too (though
355 * thankfully unlikely in SSH2 since the window mechanism should
356 * ensure that the server never has any need to throttle its end
357 * of the connection), so we set this high as well.
358 *
359 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
360 * channels.
361 */
362
363#define SSH1_BUFFER_LIMIT 32768
364#define SSH_MAX_BACKLOG 32768
365#define OUR_V2_WINSIZE 16384
d74d141c 366
a92dd380 367const static struct ssh_kex *kex_algs[] = {
a92dd380 368 &ssh_diffiehellman_gex,
32874aea 369 &ssh_diffiehellman
370};
e5574168 371
85cc02bb 372const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 373
e0e1a00d 374static void *nullmac_make_context(void)
375{
376 return NULL;
377}
378static void nullmac_free_context(void *handle)
379{
380}
381static void nullmac_key(void *handle, unsigned char *key)
32874aea 382{
383}
e0e1a00d 384static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 385 unsigned long seq)
386{
387}
e0e1a00d 388static int nullmac_verify(void *handle, unsigned char *blk, int len,
389 unsigned long seq)
32874aea 390{
391 return 1;
392}
57476f6b 393const static struct ssh_mac ssh_mac_none = {
e0e1a00d 394 nullmac_make_context, nullmac_free_context, nullmac_key,
395 nullmac_generate, nullmac_verify, "none", 0
e5574168 396};
8b2715b2 397const static struct ssh_mac *macs[] = {
32874aea 398 &ssh_sha1, &ssh_md5, &ssh_mac_none
399};
8b2715b2 400const static struct ssh_mac *buggymacs[] = {
32874aea 401 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
402};
e5574168 403
32874aea 404static void ssh_comp_none_init(void)
405{
406}
4ba9b64b 407static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 408 unsigned char **outblock, int *outlen)
409{
410 return 0;
411}
412static int ssh_comp_none_disable(void)
413{
4ba9b64b 414 return 0;
415}
57476f6b 416const static struct ssh_compress ssh_comp_none = {
4ba9b64b 417 "none",
418 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 419 ssh_comp_none_init, ssh_comp_none_block,
420 ssh_comp_none_disable
e5574168 421};
4ba9b64b 422extern const struct ssh_compress ssh_zlib;
423const static struct ssh_compress *compressions[] = {
32874aea 424 &ssh_zlib, &ssh_comp_none
425};
374330e2 426
32874aea 427enum { /* channel types */
783415f8 428 CHAN_MAINSESSION,
429 CHAN_X11,
430 CHAN_AGENT,
bc240b21 431 CHAN_SOCKDATA,
432 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 433};
434
dacbd0e8 435/*
436 * 2-3-4 tree storing channels.
437 */
438struct ssh_channel {
51470298 439 Ssh ssh; /* pointer back to main context */
d211621f 440 unsigned remoteid, localid;
dacbd0e8 441 int type;
0357890f 442 /*
443 * In SSH1, this value contains four bits:
444 *
445 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
446 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
447 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
448 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
449 *
450 * A channel is completely finished with when all four bits are set.
451 */
dacbd0e8 452 int closes;
5471d09a 453 union {
454 struct ssh1_data_channel {
455 int throttling;
456 } v1;
457 struct ssh2_data_channel {
458 bufchain outbuffer;
459 unsigned remwindow, remmaxpkt;
460 unsigned locwindow;
461 } v2;
462 } v;
dacbd0e8 463 union {
32874aea 464 struct ssh_agent_channel {
465 unsigned char *message;
466 unsigned char msglen[4];
467 int lensofar, totallen;
468 } a;
469 struct ssh_x11_channel {
470 Socket s;
471 } x11;
d74d141c 472 struct ssh_pfd_channel {
473 Socket s;
474 } pfd;
dacbd0e8 475 } u;
476};
57476f6b 477
d74d141c 478/*
bc240b21 479 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
480 * 2 use this structure in different ways, reflecting SSH 2's
481 * altogether saner approach to port forwarding.
482 *
483 * In SSH 1, you arrange a remote forwarding by sending the server
484 * the remote port number, and the local destination host:port.
485 * When a connection comes in, the server sends you back that
486 * host:port pair, and you connect to it. This is a ready-made
487 * security hole if you're not on the ball: a malicious server
488 * could send you back _any_ host:port pair, so if you trustingly
489 * connect to the address it gives you then you've just opened the
490 * entire inside of your corporate network just by connecting
491 * through it to a dodgy SSH server. Hence, we must store a list of
492 * host:port pairs we _are_ trying to forward to, and reject a
493 * connection request from the server if it's not in the list.
494 *
495 * In SSH 2, each side of the connection minds its own business and
496 * doesn't send unnecessary information to the other. You arrange a
497 * remote forwarding by sending the server just the remote port
498 * number. When a connection comes in, the server tells you which
499 * of its ports was connected to; and _you_ have to remember what
500 * local host:port pair went with that port number.
501 *
502 * Hence: in SSH 1 this structure stores host:port pairs we intend
503 * to allow connections to, and is indexed by those host:port
504 * pairs. In SSH 2 it stores a mapping from source port to
505 * destination host:port pair, and is indexed by source port.
d74d141c 506 */
507struct ssh_rportfwd {
bc240b21 508 unsigned sport, dport;
509 char dhost[256];
d74d141c 510};
511
57476f6b 512struct Packet {
513 long length;
514 int type;
515 unsigned char *data;
516 unsigned char *body;
517 long savedpos;
518 long maxlen;
519};
520
51470298 521static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
522static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
523static void ssh_size(void *handle, int width, int height);
524static void ssh_special(void *handle, Telnet_Special);
5471d09a 525static int ssh2_try_send(struct ssh_channel *c);
51470298 526static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
527static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 528static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 529static int ssh_sendbuffer(void *handle);
57476f6b 530
51470298 531struct rdpkt1_state_tag {
57476f6b 532 long len, pad, biglen, to_read;
533 unsigned long realcrc, gotcrc;
534 unsigned char *p;
535 int i;
536 int chunk;
51470298 537};
57476f6b 538
51470298 539struct rdpkt2_state_tag {
960e736a 540 long len, pad, payload, packetlen, maclen;
541 int i;
542 int cipherblk;
543 unsigned long incoming_sequence;
51470298 544};
545
546struct ssh_tag {
547 const struct plug_function_table *fn;
548 /* the above field _must_ be first in the structure */
549
550 SHA_State exhash, exhashbase;
551
552 Socket s;
553
554 unsigned char session_key[32];
555 int v1_compressing;
556 int v1_remote_protoflags;
557 int v1_local_protoflags;
558 int agentfwd_enabled;
559 int X11_fwd_enabled;
560 int remote_bugs;
561 const struct ssh_cipher *cipher;
371e569c 562 void *v1_cipher_ctx;
0183b242 563 void *crcda_ctx;
51470298 564 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 565 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 566 const struct ssh_mac *csmac, *scmac;
e0e1a00d 567 void *cs_mac_ctx, *sc_mac_ctx;
51470298 568 const struct ssh_compress *cscomp, *sccomp;
569 const struct ssh_kex *kex;
570 const struct ssh_signkey *hostkey;
571 unsigned char v2_session_id[20];
572
573 char *savedhost;
574 int savedport;
575 int send_ok;
576 int echoing, editing;
577
578 void *frontend;
579
580 int term_width, term_height;
581
582 tree234 *channels; /* indexed by local id */
583 struct ssh_channel *mainchan; /* primary session channel */
584 int exitcode;
585
586 tree234 *rportfwds;
587
588 enum {
589 SSH_STATE_PREPACKET,
590 SSH_STATE_BEFORE_SIZE,
591 SSH_STATE_INTERMED,
592 SSH_STATE_SESSION,
593 SSH_STATE_CLOSED
594 } state;
595
596 int size_needed, eof_needed;
597
598 struct Packet pktin;
599 struct Packet pktout;
600 unsigned char *deferred_send_data;
601 int deferred_len, deferred_size;
602
603 /*
604 * Gross hack: pscp will try to start SFTP but fall back to
605 * scp1 if that fails. This variable is the means by which
606 * scp.c can reach into the SSH code and find out which one it
607 * got.
608 */
609 int fallback_cmd;
610
611 /*
612 * Used for username and password input.
613 */
614 char *userpass_input_buffer;
615 int userpass_input_buflen;
616 int userpass_input_bufpos;
617 int userpass_input_echo;
618
619 char *portfwd_strptr;
620 int pkt_ctx;
621
622 int version;
623 int v1_throttle_count;
624 int overall_bufsize;
625 int throttled_all;
626 int v1_stdout_throttling;
627 int v2_outgoing_sequence;
628
629 int ssh1_rdpkt_crstate;
630 int ssh2_rdpkt_crstate;
631 int do_ssh_init_crstate;
632 int ssh_gotdata_crstate;
633 int ssh1_protocol_crstate;
634 int do_ssh1_login_crstate;
635 int do_ssh2_transport_crstate;
636 int do_ssh2_authconn_crstate;
637
638 void *do_ssh_init_state;
639 void *do_ssh1_login_state;
640 void *do_ssh2_transport_state;
641 void *do_ssh2_authconn_state;
642
643 struct rdpkt1_state_tag rdpkt1_state;
644 struct rdpkt2_state_tag rdpkt2_state;
645
646 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
647 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
648};
960e736a 649
32874aea 650static int ssh_channelcmp(void *av, void *bv)
651{
652 struct ssh_channel *a = (struct ssh_channel *) av;
653 struct ssh_channel *b = (struct ssh_channel *) bv;
654 if (a->localid < b->localid)
655 return -1;
656 if (a->localid > b->localid)
657 return +1;
dacbd0e8 658 return 0;
659}
32874aea 660static int ssh_channelfind(void *av, void *bv)
661{
662 unsigned *a = (unsigned *) av;
663 struct ssh_channel *b = (struct ssh_channel *) bv;
664 if (*a < b->localid)
665 return -1;
666 if (*a > b->localid)
667 return +1;
dacbd0e8 668 return 0;
669}
670
bc240b21 671static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 672{
673 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
674 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
675 int i;
bc240b21 676 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 677 return i < 0 ? -1 : +1;
bc240b21 678 if (a->dport > b->dport)
679 return +1;
680 if (a->dport < b->dport)
681 return -1;
682 return 0;
683}
684
685static int ssh_rportcmp_ssh2(void *av, void *bv)
686{
687 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
688 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 689
bc240b21 690 if (a->sport > b->sport)
d74d141c 691 return +1;
bc240b21 692 if (a->sport < b->sport)
693 return -1;
d74d141c 694 return 0;
695}
696
51470298 697static int alloc_channel_id(Ssh ssh)
32874aea 698{
260f3dec 699 const unsigned CHANNEL_NUMBER_OFFSET = 256;
700 unsigned low, high, mid;
d2371c81 701 int tsize;
702 struct ssh_channel *c;
703
704 /*
705 * First-fit allocation of channel numbers: always pick the
706 * lowest unused one. To do this, binary-search using the
707 * counted B-tree to find the largest channel ID which is in a
708 * contiguous sequence from the beginning. (Precisely
709 * everything in that sequence must have ID equal to its tree
710 * index plus CHANNEL_NUMBER_OFFSET.)
711 */
51470298 712 tsize = count234(ssh->channels);
d2371c81 713
32874aea 714 low = -1;
715 high = tsize;
d2371c81 716 while (high - low > 1) {
717 mid = (high + low) / 2;
51470298 718 c = index234(ssh->channels, mid);
d2371c81 719 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
720 low = mid; /* this one is fine */
721 else
722 high = mid; /* this one is past it */
723 }
724 /*
725 * Now low points to either -1, or the tree index of the
726 * largest ID in the initial sequence.
727 */
728 {
729 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 730 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 731 }
732 return low + 1 + CHANNEL_NUMBER_OFFSET;
733}
734
51470298 735static void c_write(Ssh ssh, char *buf, int len)
32874aea 736{
67779be7 737 if ((flags & FLAG_STDERR)) {
32874aea 738 int i;
739 for (i = 0; i < len; i++)
740 if (buf[i] != '\r')
741 fputc(buf[i], stderr);
fb09bf1c 742 return;
743 }
51470298 744 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 745}
746
51470298 747static void c_write_untrusted(Ssh ssh, char *buf, int len)
32874aea 748{
a209e957 749 int i;
750 for (i = 0; i < len; i++) {
32874aea 751 if (buf[i] == '\n')
51470298 752 c_write(ssh, "\r\n", 2);
32874aea 753 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 754 c_write(ssh, buf + i, 1);
a209e957 755 }
756}
757
51470298 758static void c_write_str(Ssh ssh, char *buf)
32874aea 759{
51470298 760 c_write(ssh, buf, strlen(buf));
1408a877 761}
762
fb09bf1c 763/*
764 * Collect incoming data in the incoming packet buffer.
e5574168 765 * Decipher and verify the packet when it is completely read.
766 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 767 * Update the *data and *datalen variables.
768 * Return the additional nr of bytes needed, or 0 when
769 * a complete packet is available.
770 */
51470298 771static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 772{
51470298 773 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 774
51470298 775 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 776
32874aea 777 next_packet:
37508af4 778
51470298 779 ssh->pktin.type = 0;
780 ssh->pktin.length = 0;
374330e2 781
57476f6b 782 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 783 while ((*datalen) == 0)
32874aea 784 crReturn(4 - st->i);
57476f6b 785 st->len = (st->len << 8) + **data;
fb09bf1c 786 (*data)++, (*datalen)--;
787 }
374330e2 788
57476f6b 789 st->pad = 8 - (st->len % 8);
790 st->biglen = st->len + st->pad;
51470298 791 ssh->pktin.length = st->len - 5;
fb09bf1c 792
51470298 793 if (ssh->pktin.maxlen < st->biglen) {
794 ssh->pktin.maxlen = st->biglen;
795 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
fb09bf1c 796 }
374330e2 797
57476f6b 798 st->to_read = st->biglen;
51470298 799 st->p = ssh->pktin.data;
57476f6b 800 while (st->to_read > 0) {
32874aea 801 st->chunk = st->to_read;
fb09bf1c 802 while ((*datalen) == 0)
57476f6b 803 crReturn(st->to_read);
804 if (st->chunk > (*datalen))
805 st->chunk = (*datalen);
806 memcpy(st->p, *data, st->chunk);
807 *data += st->chunk;
808 *datalen -= st->chunk;
809 st->p += st->chunk;
810 st->to_read -= st->chunk;
fb09bf1c 811 }
374330e2 812
0183b242 813 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
814 st->biglen, NULL)) {
9a3a93a5 815 bombout(("Network attack (CRC compensation) detected!"));
816 crReturn(0);
817 }
818
51470298 819 if (ssh->cipher)
371e569c 820 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 821
51470298 822 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
823 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 824 if (st->gotcrc != st->realcrc) {
8d5de777 825 bombout(("Incorrect CRC received on packet"));
32874aea 826 crReturn(0);
fb09bf1c 827 }
572f871e 828
51470298 829 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 830
51470298 831 if (ssh->v1_compressing) {
4ba9b64b 832 unsigned char *decompblk;
833 int decomplen;
51470298 834 zlib_decompress_block(ssh->pktin.body - 1, ssh->pktin.length + 1,
4ba9b64b 835 &decompblk, &decomplen);
836
51470298 837 if (ssh->pktin.maxlen < st->pad + decomplen) {
838 ssh->pktin.maxlen = st->pad + decomplen;
839 ssh->pktin.data = srealloc(ssh->pktin.data,
840 ssh->pktin.maxlen + APIEXTRA);
841 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 842 }
843
51470298 844 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 845 sfree(decompblk);
51470298 846 ssh->pktin.length = decomplen - 1;
4ba9b64b 847 }
848
51470298 849 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 850
51470298 851 log_packet(PKT_INCOMING, ssh->pktin.type, ssh1_pkt_type(ssh->pktin.type),
852 ssh->pktin.body, ssh->pktin.length);
00db133f 853
51470298 854 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
855 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
856 ssh->pktin.type == SSH1_MSG_DEBUG ||
857 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
858 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
859 long stringlen = GET_32BIT(ssh->pktin.body);
860 if (stringlen + 4 != ssh->pktin.length) {
8d5de777 861 bombout(("Received data packet with bogus string length"));
32874aea 862 crReturn(0);
863 }
fb09bf1c 864 }
865
51470298 866 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 867 /* log debug message */
eb4504cc 868 char buf[512];
51470298 869 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 870 strcpy(buf, "Remote debug message: ");
871 if (stringlen > 480)
872 stringlen = 480;
51470298 873 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 874 buf[8 + stringlen] = '\0';
fb09bf1c 875 logevent(buf);
876 goto next_packet;
51470298 877 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 878 /* do nothing */
879 goto next_packet;
880 }
881
51470298 882 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 883 /* log reason code in disconnect message */
884 char buf[256];
51470298 885 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 886 unsigned nowlen;
38c4a8da 887 strcpy(buf, "Remote sent disconnect: ");
888 nowlen = strlen(buf);
32874aea 889 if (msglen > sizeof(buf) - nowlen - 1)
890 msglen = sizeof(buf) - nowlen - 1;
51470298 891 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 892 buf[nowlen + msglen] = '\0';
247308b5 893 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 894 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 895 crReturn(0);
38c4a8da 896 }
897
fb09bf1c 898 crFinish(0);
899}
900
51470298 901static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 902{
51470298 903 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 904
51470298 905 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 906
32874aea 907 next_packet:
51470298 908 ssh->pktin.type = 0;
909 ssh->pktin.length = 0;
910 if (ssh->sccipher)
911 st->cipherblk = ssh->sccipher->blksize;
e5574168 912 else
32874aea 913 st->cipherblk = 8;
960e736a 914 if (st->cipherblk < 8)
32874aea 915 st->cipherblk = 8;
960e736a 916
51470298 917 if (ssh->pktin.maxlen < st->cipherblk) {
918 ssh->pktin.maxlen = st->cipherblk;
919 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
e5574168 920 }
921
922 /*
923 * Acquire and decrypt the first block of the packet. This will
924 * contain the length and padding details.
925 */
32874aea 926 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 927 while ((*datalen) == 0)
32874aea 928 crReturn(st->cipherblk - st->i);
51470298 929 ssh->pktin.data[st->i] = *(*data)++;
32874aea 930 (*datalen)--;
e5574168 931 }
4252c9cc 932
51470298 933 if (ssh->sccipher)
371e569c 934 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
935 ssh->pktin.data, st->cipherblk);
e5574168 936
937 /*
938 * Now get the length and padding figures.
939 */
51470298 940 st->len = GET_32BIT(ssh->pktin.data);
941 st->pad = ssh->pktin.data[4];
e5574168 942
943 /*
717dc483 944 * _Completely_ silly lengths should be stomped on before they
945 * do us any more damage.
946 */
947 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
948 bombout(("Incoming packet was garbled on decryption"));
949 crReturn(0);
950 }
951
952 /*
e5574168 953 * This enables us to deduce the payload length.
954 */
960e736a 955 st->payload = st->len - st->pad - 1;
e5574168 956
51470298 957 ssh->pktin.length = st->payload + 5;
e5574168 958
959 /*
960 * So now we can work out the total packet length.
961 */
960e736a 962 st->packetlen = st->len + 4;
51470298 963 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 964
965 /*
966 * Adjust memory allocation if packet is too big.
967 */
51470298 968 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
969 ssh->pktin.maxlen = st->packetlen + st->maclen;
970 ssh->pktin.data = srealloc(ssh->pktin.data,
971 ssh->pktin.maxlen + APIEXTRA);
e5574168 972 }
973
974 /*
975 * Read and decrypt the remainder of the packet.
976 */
32874aea 977 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
978 st->i++) {
e5574168 979 while ((*datalen) == 0)
960e736a 980 crReturn(st->packetlen + st->maclen - st->i);
51470298 981 ssh->pktin.data[st->i] = *(*data)++;
32874aea 982 (*datalen)--;
e5574168 983 }
984 /* Decrypt everything _except_ the MAC. */
51470298 985 if (ssh->sccipher)
371e569c 986 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
987 ssh->pktin.data + st->cipherblk,
51470298 988 st->packetlen - st->cipherblk);
e5574168 989
990 /*
991 * Check the MAC.
992 */
51470298 993 if (ssh->scmac
e0e1a00d 994 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 995 st->incoming_sequence)) {
8d5de777 996 bombout(("Incorrect MAC received on packet"));
32874aea 997 crReturn(0);
8d5de777 998 }
32874aea 999 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1000
4ba9b64b 1001 /*
1002 * Decompress packet payload.
1003 */
1004 {
1005 unsigned char *newpayload;
1006 int newlen;
51470298 1007 if (ssh->sccomp &&
1008 ssh->sccomp->decompress(ssh->pktin.data + 5, ssh->pktin.length - 5,
1009 &newpayload, &newlen)) {
1010 if (ssh->pktin.maxlen < newlen + 5) {
1011 ssh->pktin.maxlen = newlen + 5;
1012 ssh->pktin.data = srealloc(ssh->pktin.data,
1013 ssh->pktin.maxlen + APIEXTRA);
4ba9b64b 1014 }
51470298 1015 ssh->pktin.length = 5 + newlen;
1016 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1017 sfree(newpayload);
4ba9b64b 1018 }
1019 }
1020
51470298 1021 ssh->pktin.savedpos = 6;
1022 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1023
51470298 1024 log_packet(PKT_INCOMING, ssh->pktin.type,
1025 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1026 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1027
51470298 1028 switch (ssh->pktin.type) {
3d63ca2e 1029 /*
1030 * These packets we must handle instantly.
1031 */
1032 case SSH2_MSG_DISCONNECT:
1033 {
1034 /* log reason code in disconnect message */
1035 char buf[256];
51470298 1036 int reason = GET_32BIT(ssh->pktin.data + 6);
1037 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
3d63ca2e 1038 unsigned nowlen;
1039 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1040 sprintf(buf, "Received disconnect message (%s)",
1041 ssh2_disconnect_reasons[reason]);
1042 } else {
1043 sprintf(buf, "Received disconnect message (unknown type %d)",
1044 reason);
1045 }
1046 logevent(buf);
1047 strcpy(buf, "Disconnection message text: ");
1048 nowlen = strlen(buf);
1049 if (msglen > sizeof(buf) - nowlen - 1)
1050 msglen = sizeof(buf) - nowlen - 1;
51470298 1051 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
3d63ca2e 1052 buf[nowlen + msglen] = '\0';
1053 logevent(buf);
1054 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1055 reason,
1056 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1057 ssh2_disconnect_reasons[reason] : "unknown",
1058 buf+nowlen));
1059 crReturn(0);
1060 }
1061 break;
1062 case SSH2_MSG_IGNORE:
1063 goto next_packet;
1064 case SSH2_MSG_DEBUG:
1065 {
1066 /* log the debug message */
1067 char buf[512];
51470298 1068 /* int display = ssh->pktin.body[6]; */
1069 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1070 int prefix;
1071 strcpy(buf, "Remote debug message: ");
1072 prefix = strlen(buf);
51470298 1073 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1074 stringlen = sizeof(buf)-prefix-1;
51470298 1075 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1076 buf[prefix + stringlen] = '\0';
1077 logevent(buf);
38c4a8da 1078 }
3d63ca2e 1079 goto next_packet; /* FIXME: print the debug message */
1080
1081 /*
1082 * These packets we need do nothing about here.
1083 */
1084 case SSH2_MSG_UNIMPLEMENTED:
1085 case SSH2_MSG_SERVICE_REQUEST:
1086 case SSH2_MSG_SERVICE_ACCEPT:
1087 case SSH2_MSG_KEXINIT:
1088 case SSH2_MSG_NEWKEYS:
1089 case SSH2_MSG_KEXDH_INIT:
1090 case SSH2_MSG_KEXDH_REPLY:
1091 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1092 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1093 case SSH2_MSG_KEX_DH_GEX_INIT:
1094 case SSH2_MSG_KEX_DH_GEX_REPLY:
1095 case SSH2_MSG_USERAUTH_REQUEST:
1096 case SSH2_MSG_USERAUTH_FAILURE:
1097 case SSH2_MSG_USERAUTH_SUCCESS:
1098 case SSH2_MSG_USERAUTH_BANNER:
1099 case SSH2_MSG_USERAUTH_PK_OK:
1100 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1101 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1102 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1103 case SSH2_MSG_GLOBAL_REQUEST:
1104 case SSH2_MSG_REQUEST_SUCCESS:
1105 case SSH2_MSG_REQUEST_FAILURE:
1106 case SSH2_MSG_CHANNEL_OPEN:
1107 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1108 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1109 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1110 case SSH2_MSG_CHANNEL_DATA:
1111 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1112 case SSH2_MSG_CHANNEL_EOF:
1113 case SSH2_MSG_CHANNEL_CLOSE:
1114 case SSH2_MSG_CHANNEL_REQUEST:
1115 case SSH2_MSG_CHANNEL_SUCCESS:
1116 case SSH2_MSG_CHANNEL_FAILURE:
1117 break;
1118
1119 /*
1120 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1121 */
1122 default:
51470298 1123 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1124 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1125 ssh2_pkt_send(ssh);
3d63ca2e 1126 break;
38c4a8da 1127 }
1128
e5574168 1129 crFinish(0);
1130}
1131
51470298 1132static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1133{
374330e2 1134 int pad, biglen;
1135
1136 len += 5; /* type and CRC */
32874aea 1137 pad = 8 - (len % 8);
374330e2 1138 biglen = len + pad;
1139
51470298 1140 ssh->pktout.length = len - 5;
1141 if (ssh->pktout.maxlen < biglen) {
1142 ssh->pktout.maxlen = biglen;
8f203108 1143#ifdef MSCRYPTOAPI
fb09bf1c 1144 /* Allocate enough buffer space for extra block
8f203108 1145 * for MS CryptEncrypt() */
51470298 1146 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
8f203108 1147#else
51470298 1148 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
8f203108 1149#endif
374330e2 1150 }
51470298 1151 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1152}
374330e2 1153
51470298 1154static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1155{
51470298 1156 ssh1_pktout_size(ssh, len);
1157 ssh->pktout.type = type;
374330e2 1158}
1159
51470298 1160static int s_wrpkt_prepare(Ssh ssh)
32874aea 1161{
374330e2 1162 int pad, len, biglen, i;
1163 unsigned long crc;
1164
51470298 1165 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1166
51470298 1167 log_packet(PKT_OUTGOING, ssh->pktout.type, ssh1_pkt_type(ssh->pktout.type),
1168 ssh->pktout.body, ssh->pktout.length);
00db133f 1169
51470298 1170 if (ssh->v1_compressing) {
4ba9b64b 1171 unsigned char *compblk;
1172 int complen;
51470298 1173 zlib_compress_block(ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1174 &compblk, &complen);
51470298 1175 ssh1_pktout_size(ssh, complen - 1);
1176 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1177 sfree(compblk);
4ba9b64b 1178 }
1179
51470298 1180 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1181 pad = 8 - (len % 8);
374330e2 1182 biglen = len + pad;
1183
32874aea 1184 for (i = 0; i < pad; i++)
51470298 1185 ssh->pktout.data[i + 4] = random_byte();
1186 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1187 PUT_32BIT(ssh->pktout.data + biglen, crc);
1188 PUT_32BIT(ssh->pktout.data, len);
374330e2 1189
51470298 1190 if (ssh->cipher)
371e569c 1191 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1192
32874aea 1193 return biglen + 4;
39065bed 1194}
1195
51470298 1196static void s_wrpkt(Ssh ssh)
32874aea 1197{
5471d09a 1198 int len, backlog;
51470298 1199 len = s_wrpkt_prepare(ssh);
1200 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1201 if (backlog > SSH_MAX_BACKLOG)
51470298 1202 ssh_throttle_all(ssh, 1, backlog);
39065bed 1203}
1204
51470298 1205static void s_wrpkt_defer(Ssh ssh)
32874aea 1206{
39065bed 1207 int len;
51470298 1208 len = s_wrpkt_prepare(ssh);
1209 if (ssh->deferred_len + len > ssh->deferred_size) {
1210 ssh->deferred_size = ssh->deferred_len + len + 128;
1211 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1212 ssh->deferred_size);
39065bed 1213 }
51470298 1214 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1215 ssh->deferred_len += len;
374330e2 1216}
1217
fb09bf1c 1218/*
39065bed 1219 * Construct a packet with the specified contents.
fb09bf1c 1220 */
51470298 1221static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1222{
fb09bf1c 1223 unsigned char *p, *argp, argchar;
1224 unsigned long argint;
1225 int pktlen, argtype, arglen;
7cca0d81 1226 Bignum bn;
fb09bf1c 1227
1228 pktlen = 0;
39065bed 1229 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1230 switch (argtype) {
1231 case PKT_INT:
39065bed 1232 (void) va_arg(ap1, int);
fb09bf1c 1233 pktlen += 4;
1234 break;
1235 case PKT_CHAR:
39065bed 1236 (void) va_arg(ap1, char);
fb09bf1c 1237 pktlen++;
1238 break;
1239 case PKT_DATA:
39065bed 1240 (void) va_arg(ap1, unsigned char *);
1241 arglen = va_arg(ap1, int);
fb09bf1c 1242 pktlen += arglen;
1243 break;
1244 case PKT_STR:
39065bed 1245 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1246 arglen = strlen(argp);
1247 pktlen += 4 + arglen;
1248 break;
7cca0d81 1249 case PKT_BIGNUM:
39065bed 1250 bn = va_arg(ap1, Bignum);
32874aea 1251 pktlen += ssh1_bignum_length(bn);
7cca0d81 1252 break;
fb09bf1c 1253 default:
1254 assert(0);
1255 }
1256 }
fb09bf1c 1257
51470298 1258 s_wrpkt_start(ssh, pkttype, pktlen);
1259 p = ssh->pktout.body;
fb09bf1c 1260
39065bed 1261 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1262 switch (argtype) {
1263 case PKT_INT:
39065bed 1264 argint = va_arg(ap2, int);
fb09bf1c 1265 PUT_32BIT(p, argint);
1266 p += 4;
1267 break;
1268 case PKT_CHAR:
39065bed 1269 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1270 *p = argchar;
1271 p++;
1272 break;
1273 case PKT_DATA:
39065bed 1274 argp = va_arg(ap2, unsigned char *);
1275 arglen = va_arg(ap2, int);
fb09bf1c 1276 memcpy(p, argp, arglen);
1277 p += arglen;
1278 break;
1279 case PKT_STR:
39065bed 1280 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1281 arglen = strlen(argp);
1282 PUT_32BIT(p, arglen);
1283 memcpy(p + 4, argp, arglen);
1284 p += 4 + arglen;
1285 break;
7cca0d81 1286 case PKT_BIGNUM:
39065bed 1287 bn = va_arg(ap2, Bignum);
32874aea 1288 p += ssh1_write_bignum(p, bn);
7cca0d81 1289 break;
fb09bf1c 1290 }
1291 }
39065bed 1292}
fb09bf1c 1293
51470298 1294static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1295{
39065bed 1296 va_list ap1, ap2;
1297 va_start(ap1, pkttype);
1298 va_start(ap2, pkttype);
51470298 1299 construct_packet(ssh, pkttype, ap1, ap2);
1300 s_wrpkt(ssh);
fb09bf1c 1301}
1302
51470298 1303static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1304{
39065bed 1305 va_list ap1, ap2;
1306 va_start(ap1, pkttype);
1307 va_start(ap2, pkttype);
51470298 1308 construct_packet(ssh, pkttype, ap1, ap2);
1309 s_wrpkt_defer(ssh);
39065bed 1310}
1311
32874aea 1312static int ssh_versioncmp(char *a, char *b)
1313{
9697bfd2 1314 char *ae, *be;
1315 unsigned long av, bv;
1316
43aa02a7 1317 av = strtoul(a, &ae, 10);
1318 bv = strtoul(b, &be, 10);
32874aea 1319 if (av != bv)
1320 return (av < bv ? -1 : +1);
1321 if (*ae == '.')
1322 ae++;
1323 if (*be == '.')
1324 be++;
43aa02a7 1325 av = strtoul(ae, &ae, 10);
1326 bv = strtoul(be, &be, 10);
32874aea 1327 if (av != bv)
1328 return (av < bv ? -1 : +1);
9697bfd2 1329 return 0;
1330}
1331
e5574168 1332/*
a92dd380 1333 * Utility routines for putting an SSH-protocol `string' and
1334 * `uint32' into a SHA state.
e5574168 1335 */
1336#include <stdio.h>
32874aea 1337static void sha_string(SHA_State * s, void *str, int len)
1338{
e5574168 1339 unsigned char lenblk[4];
e5574168 1340 PUT_32BIT(lenblk, len);
e5574168 1341 SHA_Bytes(s, lenblk, 4);
e5574168 1342 SHA_Bytes(s, str, len);
1343}
1344
32874aea 1345static void sha_uint32(SHA_State * s, unsigned i)
1346{
a92dd380 1347 unsigned char intblk[4];
1348 PUT_32BIT(intblk, i);
1349 SHA_Bytes(s, intblk, 4);
1350}
1351
7cca0d81 1352/*
1353 * SSH2 packet construction functions.
1354 */
51470298 1355static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1356{
51470298 1357 if (ssh->pktout.maxlen < length) {
1358 ssh->pktout.maxlen = length + 256;
1359 ssh->pktout.data = srealloc(ssh->pktout.data,
1360 ssh->pktout.maxlen + APIEXTRA);
1361 if (!ssh->pktout.data)
32874aea 1362 fatalbox("Out of memory");
7cca0d81 1363 }
783415f8 1364}
51470298 1365static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1366{
51470298 1367 ssh->pktout.length += len;
1368 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1369 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1370}
51470298 1371static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1372{
51470298 1373 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1374}
51470298 1375static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1376{
51470298 1377 ssh->pktout.length = 5;
1378 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1379}
51470298 1380static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1381{
51470298 1382 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1383}
51470298 1384static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1385{
7cca0d81 1386 unsigned char x[4];
1387 PUT_32BIT(x, value);
51470298 1388 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1389}
51470298 1390static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1391{
51470298 1392 ssh2_pkt_adduint32(ssh, 0);
1393 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1394}
51470298 1395static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1396{
51470298 1397 ssh2_pkt_adddata(ssh, data, strlen(data));
1398 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1399 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1400}
51470298 1401static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1402{
51470298 1403 ssh2_pkt_adddata(ssh, data, len);
1404 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1405 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1406}
51470298 1407static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1408{
51470298 1409 ssh2_pkt_addstring_start(ssh);
1410 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1411}
32874aea 1412static char *ssh2_mpint_fmt(Bignum b, int *len)
1413{
7cca0d81 1414 unsigned char *p;
32874aea 1415 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1416 p = smalloc(n + 1);
7cca0d81 1417 if (!p)
32874aea 1418 fatalbox("out of memory");
7cca0d81 1419 p[0] = 0;
3709bfe9 1420 for (i = 1; i <= n; i++)
32874aea 1421 p[i] = bignum_byte(b, n - i);
7cca0d81 1422 i = 0;
32874aea 1423 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1424 i++;
1425 memmove(p, p + i, n + 1 - i);
1426 *len = n + 1 - i;
7cca0d81 1427 return p;
1428}
51470298 1429static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1430{
7cca0d81 1431 unsigned char *p;
1432 int len;
1433 p = ssh2_mpint_fmt(b, &len);
51470298 1434 ssh2_pkt_addstring_start(ssh);
1435 ssh2_pkt_addstring_data(ssh, p, len);
dcbde236 1436 sfree(p);
7cca0d81 1437}
b185170a 1438
1439/*
1440 * Construct an SSH2 final-form packet: compress it, encrypt it,
1441 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1442 * ssh->pktout.data. Total length is returned.
b185170a 1443 */
51470298 1444static int ssh2_pkt_construct(Ssh ssh)
32874aea 1445{
7cca0d81 1446 int cipherblk, maclen, padding, i;
7cca0d81 1447
51470298 1448 log_packet(PKT_OUTGOING, ssh->pktout.data[5],
1449 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1450 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1451
7cca0d81 1452 /*
4ba9b64b 1453 * Compress packet payload.
1454 */
4ba9b64b 1455 {
1456 unsigned char *newpayload;
1457 int newlen;
51470298 1458 if (ssh->cscomp &&
1459 ssh->cscomp->compress(ssh->pktout.data + 5, ssh->pktout.length - 5,
1460 &newpayload, &newlen)) {
1461 ssh->pktout.length = 5;
1462 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1463 sfree(newpayload);
4ba9b64b 1464 }
1465 }
1466
1467 /*
7cca0d81 1468 * Add padding. At least four bytes, and must also bring total
1469 * length (minus MAC) up to a multiple of the block size.
1470 */
51470298 1471 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1472 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1473 padding = 4;
32874aea 1474 padding +=
51470298 1475 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1476 maclen = ssh->csmac ? ssh->csmac->len : 0;
1477 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1478 ssh->pktout.data[4] = padding;
7cca0d81 1479 for (i = 0; i < padding; i++)
51470298 1480 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1481 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1482 if (ssh->csmac)
e0e1a00d 1483 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1484 ssh->pktout.length + padding,
51470298 1485 ssh->v2_outgoing_sequence);
1486 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1487
1488 if (ssh->cscipher)
371e569c 1489 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1490 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1491
1492 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1493 return ssh->pktout.length + padding + maclen;
b185170a 1494}
1495
1496/*
1497 * Construct and send an SSH2 packet immediately.
1498 */
51470298 1499static void ssh2_pkt_send(Ssh ssh)
32874aea 1500{
5471d09a 1501 int len;
1502 int backlog;
51470298 1503 len = ssh2_pkt_construct(ssh);
1504 backlog = sk_write(ssh->s, ssh->pktout.data, len);
5471d09a 1505 if (backlog > SSH_MAX_BACKLOG)
51470298 1506 ssh_throttle_all(ssh, 1, backlog);
b185170a 1507}
1508
1509/*
1510 * Construct an SSH2 packet and add it to a deferred data block.
1511 * Useful for sending multiple packets in a single sk_write() call,
1512 * to prevent a traffic-analysing listener from being able to work
1513 * out the length of any particular packet (such as the password
1514 * packet).
1515 *
1516 * Note that because SSH2 sequence-numbers its packets, this can
1517 * NOT be used as an m4-style `defer' allowing packets to be
1518 * constructed in one order and sent in another.
1519 */
51470298 1520static void ssh2_pkt_defer(Ssh ssh)
32874aea 1521{
51470298 1522 int len = ssh2_pkt_construct(ssh);
1523 if (ssh->deferred_len + len > ssh->deferred_size) {
1524 ssh->deferred_size = ssh->deferred_len + len + 128;
1525 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1526 ssh->deferred_size);
b185170a 1527 }
51470298 1528 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1529 ssh->deferred_len += len;
b185170a 1530}
1531
1532/*
1533 * Send the whole deferred data block constructed by
39065bed 1534 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1535 */
51470298 1536static void ssh_pkt_defersend(Ssh ssh)
32874aea 1537{
5471d09a 1538 int backlog;
51470298 1539 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1540 ssh->deferred_len = ssh->deferred_size = 0;
1541 sfree(ssh->deferred_send_data);
1542 ssh->deferred_send_data = NULL;
5471d09a 1543 if (backlog > SSH_MAX_BACKLOG)
51470298 1544 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1545}
1546
1547#if 0
32874aea 1548void bndebug(char *string, Bignum b)
1549{
7cca0d81 1550 unsigned char *p;
1551 int i, len;
1552 p = ssh2_mpint_fmt(b, &len);
1553 debug(("%s", string));
1554 for (i = 0; i < len; i++)
32874aea 1555 debug((" %02x", p[i]));
765c4200 1556 debug(("\n"));
dcbde236 1557 sfree(p);
7cca0d81 1558}
1559#endif
1560
32874aea 1561static void sha_mpint(SHA_State * s, Bignum b)
1562{
7cca0d81 1563 unsigned char *p;
1564 int len;
1565 p = ssh2_mpint_fmt(b, &len);
1566 sha_string(s, p, len);
dcbde236 1567 sfree(p);
7cca0d81 1568}
1569
1570/*
1571 * SSH2 packet decode functions.
1572 */
51470298 1573static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1574{
7cca0d81 1575 unsigned long value;
51470298 1576 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1577 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1578 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1579 ssh->pktin.savedpos += 4;
7cca0d81 1580 return value;
1581}
51470298 1582static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1583{
65a22376 1584 unsigned long value;
51470298 1585 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1586 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1587 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1588 ssh->pktin.savedpos++;
65a22376 1589 return value;
1590}
51470298 1591static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1592{
7cca0d81 1593 *p = NULL;
45068b27 1594 *length = 0;
51470298 1595 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1596 return;
51470298 1597 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1598 ssh->pktin.savedpos += 4;
1599 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1600 return;
51470298 1601 *p = ssh->pktin.data + ssh->pktin.savedpos;
1602 ssh->pktin.savedpos += *length;
7cca0d81 1603}
51470298 1604static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1605{
7cca0d81 1606 char *p;
3709bfe9 1607 int length;
7cca0d81 1608 Bignum b;
1609
51470298 1610 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1611 if (!p)
32874aea 1612 return NULL;
8d5de777 1613 if (p[0] & 0x80) {
32874aea 1614 bombout(("internal error: Can't handle negative mpints"));
1615 return NULL;
8d5de777 1616 }
3709bfe9 1617 b = bignum_from_bytes(p, length);
7cca0d81 1618 return b;
1619}
1620
7d503c31 1621/*
1dd353b5 1622 * Helper function to add an SSH2 signature blob to a packet.
1623 * Expects to be shown the public key blob as well as the signature
1624 * blob. Normally works just like ssh2_pkt_addstring, but will
1625 * fiddle with the signature packet if necessary for
1626 * BUG_SSH2_RSA_PADDING.
1627 */
51470298 1628static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1629 void *sigblob_v, int sigblob_len)
1630{
1631 unsigned char *pkblob = (unsigned char *)pkblob_v;
1632 unsigned char *sigblob = (unsigned char *)sigblob_v;
1633
1634 /* dmemdump(pkblob, pkblob_len); */
1635 /* dmemdump(sigblob, sigblob_len); */
1636
1637 /*
1638 * See if this is in fact an ssh-rsa signature and a buggy
1639 * server; otherwise we can just do this the easy way.
1640 */
51470298 1641 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1642 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1643 int pos, len, siglen;
1644
1645 /*
1646 * Find the byte length of the modulus.
1647 */
1648
1649 pos = 4+7; /* skip over "ssh-rsa" */
1650 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1651 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1652 pos += 4; /* find modulus itself */
1653 while (len > 0 && pkblob[pos] == 0)
1654 len--, pos++;
1655 /* debug(("modulus length is %d\n", len)); */
1656
1657 /*
1658 * Now find the signature integer.
1659 */
1660 pos = 4+7; /* skip over "ssh-rsa" */
1661 siglen = GET_32BIT(sigblob+pos);
1662 /* debug(("signature length is %d\n", siglen)); */
1663
1664 if (len != siglen) {
1665 unsigned char newlen[4];
51470298 1666 ssh2_pkt_addstring_start(ssh);
1667 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1dd353b5 1668 /* dmemdump(sigblob, pos); */
1669 pos += 4; /* point to start of actual sig */
1670 PUT_32BIT(newlen, len);
51470298 1671 ssh2_pkt_addstring_data(ssh, newlen, 4);
1dd353b5 1672 /* dmemdump(newlen, 4); */
1673 newlen[0] = 0;
1674 while (len-- > siglen) {
51470298 1675 ssh2_pkt_addstring_data(ssh, newlen, 1);
1dd353b5 1676 /* dmemdump(newlen, 1); */
1677 }
51470298 1678 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1dd353b5 1679 /* dmemdump(sigblob+pos, siglen); */
1680 return;
1681 }
1682
1683 /* Otherwise fall through and do it the easy way. */
1684 }
1685
51470298 1686 ssh2_pkt_addstring_start(ssh);
1687 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1dd353b5 1688}
1689
1690/*
7d503c31 1691 * Examine the remote side's version string and compare it against
1692 * a list of known buggy implementations.
1693 */
51470298 1694static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1695{
1696 char *imp; /* pointer to implementation part */
7d503c31 1697 imp = vstring;
1698 imp += strcspn(imp, "-");
bd358db1 1699 if (*imp) imp++;
7d503c31 1700 imp += strcspn(imp, "-");
bd358db1 1701 if (*imp) imp++;
7d503c31 1702
51470298 1703 ssh->remote_bugs = 0;
7d503c31 1704
2c9c6388 1705 if (cfg.sshbug_ignore1 == BUG_ON ||
1706 (cfg.sshbug_ignore1 == BUG_AUTO &&
1707 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1708 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1709 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1710 /*
1711 * These versions don't support SSH1_MSG_IGNORE, so we have
1712 * to use a different defence against password length
1713 * sniffing.
1714 */
51470298 1715 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1716 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1717 }
1718
2c9c6388 1719 if (cfg.sshbug_plainpw1 == BUG_ON ||
1720 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1721 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1722 /*
1723 * These versions need a plain password sent; they can't
1724 * handle having a null and a random length of data after
1725 * the password.
1726 */
51470298 1727 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1728 logevent("We believe remote version needs a plain SSH1 password");
1729 }
1730
2c9c6388 1731 if (cfg.sshbug_rsa1 == BUG_ON ||
1732 (cfg.sshbug_rsa1 == BUG_AUTO &&
1733 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1734 /*
1735 * These versions apparently have no clue whatever about
1736 * RSA authentication and will panic and die if they see
1737 * an AUTH_RSA message.
1738 */
51470298 1739 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1740 logevent("We believe remote version can't handle RSA authentication");
1741 }
1742
2c9c6388 1743 if (cfg.sshbug_hmac2 == BUG_ON ||
1744 (cfg.sshbug_hmac2 == BUG_AUTO &&
1745 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1746 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1747 !strncmp(imp, "2.1 ", 4)))) {
32874aea 1748 /*
1749 * These versions have the HMAC bug.
1750 */
51470298 1751 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1752 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1753 }
1dd353b5 1754
2c9c6388 1755 if (cfg.sshbug_derivekey2 == BUG_ON ||
1756 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1757 (!strncmp(imp, "2.0.", 4)))) {
088bde77 1758 /*
1759 * These versions have the key-derivation bug (failing to
1760 * include the literal shared secret in the hashes that
1761 * generate the keys).
1762 */
51470298 1763 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1764 logevent("We believe remote version has SSH2 key-derivation bug");
1765 }
1766
2c9c6388 1767 if (cfg.sshbug_rsapad2 == BUG_ON ||
1768 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1769 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1770 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1dd353b5 1771 /*
1772 * These versions have the SSH2 RSA padding bug.
1773 */
51470298 1774 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1775 logevent("We believe remote version has SSH2 RSA padding bug");
1776 }
8e975795 1777
1778 if (cfg.sshbug_dhgex2 == BUG_ON) {
1779 /*
1780 * These versions have the SSH2 DH GEX bug.
1781 */
51470298 1782 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1783 logevent("We believe remote version has SSH2 DH group exchange bug");
1784 }
7d503c31 1785}
1786
51470298 1787static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1788{
51470298 1789 struct do_ssh_init_state {
1790 int vslen;
1791 char version[10];
1792 char *vstring;
1793 int vstrsize;
1794 int i;
1795 int proto1, proto2;
1796 };
1797 crState(do_ssh_init_state);
374330e2 1798
51470298 1799 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1800
1801 /* Search for the string "SSH-" in the input. */
51470298 1802 s->i = 0;
8df7a775 1803 while (1) {
1804 static const int transS[] = { 1, 2, 2, 1 };
1805 static const int transH[] = { 0, 0, 3, 0 };
1806 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1807 if (c == 'S')
51470298 1808 s->i = transS[s->i];
32874aea 1809 else if (c == 'H')
51470298 1810 s->i = transH[s->i];
32874aea 1811 else if (c == '-')
51470298 1812 s->i = transminus[s->i];
32874aea 1813 else
51470298 1814 s->i = 0;
1815 if (s->i < 0)
8df7a775 1816 break;
1817 crReturn(1); /* get another character */
374330e2 1818 }
8df7a775 1819
51470298 1820 s->vstrsize = 16;
1821 s->vstring = smalloc(s->vstrsize);
1822 strcpy(s->vstring, "SSH-");
1823 s->vslen = 4;
1824 s->i = 0;
374330e2 1825 while (1) {
8df7a775 1826 crReturn(1); /* get another char */
51470298 1827 if (s->vslen >= s->vstrsize - 1) {
1828 s->vstrsize += 16;
1829 s->vstring = srealloc(s->vstring, s->vstrsize);
32874aea 1830 }
51470298 1831 s->vstring[s->vslen++] = c;
1832 if (s->i >= 0) {
374330e2 1833 if (c == '-') {
51470298 1834 s->version[s->i] = '\0';
1835 s->i = -1;
1836 } else if (s->i < sizeof(s->version) - 1)
1837 s->version[s->i++] = c;
32874aea 1838 } else if (c == '\n')
374330e2 1839 break;
1840 }
1841
51470298 1842 ssh->agentfwd_enabled = FALSE;
1843 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1844
51470298 1845 s->vstring[s->vslen] = 0;
1846 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1847 {
1848 char *vlog;
1849 vlog = smalloc(20 + s->vslen);
1850 sprintf(vlog, "Server version: %s", s->vstring);
1851 logevent(vlog);
1852 sfree(vlog);
1853 }
1854 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1855
adf799dd 1856 /*
38d228a2 1857 * Decide which SSH protocol version to support.
adf799dd 1858 */
38d228a2 1859
1860 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1861 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1862 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1863 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1864
51470298 1865 if (cfg.sshprot == 0 && !s->proto1) {
38d228a2 1866 bombout(("SSH protocol version 1 required by user but not provided by server"));
1867 crReturn(0);
1868 }
51470298 1869 if (cfg.sshprot == 3 && !s->proto2) {
38d228a2 1870 bombout(("SSH protocol version 2 required by user but not provided by server"));
1871 crReturn(0);
1872 }
1873
51470298 1874 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1875 /*
38d228a2 1876 * Use v2 protocol.
32874aea 1877 */
1878 char verstring[80], vlog[100];
1879 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1880 SHA_Init(&ssh->exhashbase);
32874aea 1881 /*
1882 * Hash our version string and their version string.
1883 */
51470298 1884 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1885 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1886 sprintf(vlog, "We claim version: %s", verstring);
1887 logevent(vlog);
1888 strcat(verstring, "\n");
1889 logevent("Using SSH protocol version 2");
51470298 1890 sk_write(ssh->s, verstring, strlen(verstring));
1891 ssh->protocol = ssh2_protocol;
1892 ssh->version = 2;
1893 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1894 } else {
32874aea 1895 /*
38d228a2 1896 * Use v1 protocol.
32874aea 1897 */
1898 char verstring[80], vlog[100];
1899 sprintf(verstring, "SSH-%s-%s",
51470298 1900 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1901 sshver);
1902 sprintf(vlog, "We claim version: %s", verstring);
1903 logevent(vlog);
1904 strcat(verstring, "\n");
759712a6 1905
32874aea 1906 logevent("Using SSH protocol version 1");
51470298 1907 sk_write(ssh->s, verstring, strlen(verstring));
1908 ssh->protocol = ssh1_protocol;
1909 ssh->version = 1;
1910 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1911 }
51470298 1912 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1913
51470298 1914 sfree(s->vstring);
50526e47 1915
8df7a775 1916 crFinish(0);
1917}
1918
51470298 1919static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 1920{
51470298 1921 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 1922
1923 /*
1924 * To begin with, feed the characters one by one to the
1925 * protocol initialisation / selection function do_ssh_init().
1926 * When that returns 0, we're done with the initial greeting
1927 * exchange and can move on to packet discipline.
1928 */
1929 while (1) {
51470298 1930 int ret; /* need not be kept across crReturn */
8df7a775 1931 if (datalen == 0)
1932 crReturnV; /* more data please */
51470298 1933 ret = do_ssh_init(ssh, *data);
32874aea 1934 data++;
1935 datalen--;
8df7a775 1936 if (ret == 0)
1937 break;
1938 }
1939
1940 /*
1941 * We emerge from that loop when the initial negotiation is
1942 * over and we have selected an s_rdpkt function. Now pass
1943 * everything to s_rdpkt, and then pass the resulting packets
1944 * to the proper protocol handler.
1945 */
1946 if (datalen == 0)
1947 crReturnV;
1948 while (1) {
1949 while (datalen > 0) {
51470298 1950 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1951 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 1952 return;
1953 }
51470298 1954 ssh->protocol(ssh, NULL, 0, 1);
1955 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 1956 return;
1957 }
1958 }
1959 }
1960 crReturnV;
1961 }
1962 crFinishV;
1963}
1964
32874aea 1965static int ssh_closing(Plug plug, char *error_msg, int error_code,
1966 int calling_back)
1967{
51470298 1968 Ssh ssh = (Ssh) plug;
1969 ssh->state = SSH_STATE_CLOSED;
1970 if (ssh->s) {
1971 sk_close(ssh->s);
1972 ssh->s = NULL;
f3ab576e 1973 }
7e78000d 1974 if (error_msg) {
32874aea 1975 /* A socket error has occurred. */
247308b5 1976 logevent(error_msg);
32874aea 1977 connection_fatal(error_msg);
7e78000d 1978 } else {
1979 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1980 }
7e78000d 1981 return 0;
1982}
1983
32874aea 1984static int ssh_receive(Plug plug, int urgent, char *data, int len)
1985{
51470298 1986 Ssh ssh = (Ssh) plug;
1987 ssh_gotdata(ssh, data, len);
1988 if (ssh->state == SSH_STATE_CLOSED) {
1989 if (ssh->s) {
1990 sk_close(ssh->s);
1991 ssh->s = NULL;
32874aea 1992 }
1993 return 0;
3257deae 1994 }
fef97f43 1995 return 1;
374330e2 1996}
1997
5471d09a 1998static void ssh_sent(Plug plug, int bufsize)
1999{
51470298 2000 Ssh ssh = (Ssh) plug;
5471d09a 2001 /*
2002 * If the send backlog on the SSH socket itself clears, we
2003 * should unthrottle the whole world if it was throttled.
2004 */
2005 if (bufsize < SSH_MAX_BACKLOG)
51470298 2006 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2007}
2008
fb09bf1c 2009/*
8df7a775 2010 * Connect to specified host and port.
2011 * Returns an error message, or NULL on success.
6e1ebb76 2012 * Also places the canonical host name into `realhost'. It must be
2013 * freed by the caller.
8df7a775 2014 */
51470298 2015static char *connect_to_host(Ssh ssh, char *host, int port,
2016 char **realhost, int nodelay)
8df7a775 2017{
51470298 2018 static const struct plug_function_table fn_table = {
7e78000d 2019 ssh_closing,
5471d09a 2020 ssh_receive,
2021 ssh_sent,
2022 NULL
51470298 2023 };
7e78000d 2024
8df7a775 2025 SockAddr addr;
2026 char *err;
8df7a775 2027
51470298 2028 ssh->savedhost = smalloc(1 + strlen(host));
2029 if (!ssh->savedhost)
8df7a775 2030 fatalbox("Out of memory");
51470298 2031 strcpy(ssh->savedhost, host);
8df7a775 2032
2033 if (port < 0)
2034 port = 22; /* default ssh port */
51470298 2035 ssh->savedport = port;
8df7a775 2036
2037 /*
2038 * Try to find host.
2039 */
3ad9d396 2040 {
2041 char buf[200];
2042 sprintf(buf, "Looking up host \"%.170s\"", host);
2043 logevent(buf);
2044 }
8df7a775 2045 addr = sk_namelookup(host, realhost);
32874aea 2046 if ((err = sk_addr_error(addr)))
8df7a775 2047 return err;
2048
8df7a775 2049 /*
2050 * Open socket.
2051 */
3ad9d396 2052 {
2053 char buf[200], addrbuf[100];
2054 sk_getaddr(addr, addrbuf, 100);
2055 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2056 logevent(buf);
2057 }
51470298 2058 ssh->fn = &fn_table;
2059 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2060 if ((err = sk_socket_error(ssh->s))) {
2061 ssh->s = NULL;
8df7a775 2062 return err;
67c4ba2e 2063 }
8df7a775 2064
8df7a775 2065 return NULL;
2066}
2067
2068/*
5471d09a 2069 * Throttle or unthrottle the SSH connection.
2070 */
51470298 2071static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2072{
51470298 2073 int old_count = ssh->v1_throttle_count;
2074 ssh->v1_throttle_count += adjust;
2075 assert(ssh->v1_throttle_count >= 0);
2076 if (ssh->v1_throttle_count && !old_count) {
2077 sk_set_frozen(ssh->s, 1);
2078 } else if (!ssh->v1_throttle_count && old_count) {
2079 sk_set_frozen(ssh->s, 0);
5471d09a 2080 }
2081}
2082
2083/*
2084 * Throttle or unthrottle _all_ local data streams (for when sends
2085 * on the SSH connection itself back up).
2086 */
51470298 2087static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2088{
2089 int i;
2090 struct ssh_channel *c;
2091
51470298 2092 if (enable == ssh->throttled_all)
5471d09a 2093 return;
51470298 2094 ssh->throttled_all = enable;
2095 ssh->overall_bufsize = bufsize;
2096 if (!ssh->channels)
5471d09a 2097 return;
51470298 2098 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2099 switch (c->type) {
2100 case CHAN_MAINSESSION:
2101 /*
2102 * This is treated separately, outside the switch.
2103 */
2104 break;
2105 case CHAN_X11:
2106 x11_override_throttle(c->u.x11.s, enable);
2107 break;
2108 case CHAN_AGENT:
2109 /* Agent channels require no buffer management. */
2110 break;
2111 case CHAN_SOCKDATA:
2112 pfd_override_throttle(c->u.x11.s, enable);
2113 break;
2114 }
2115 }
2116}
2117
2118/*
51470298 2119 * Username and password input, abstracted off into routines
2120 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2121 */
0405e71f 2122
2123/* Set up a username or password input loop on a given buffer. */
51470298 2124void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2125{
51470298 2126 ssh->userpass_input_buffer = buffer;
2127 ssh->userpass_input_buflen = buflen;
2128 ssh->userpass_input_bufpos = 0;
2129 ssh->userpass_input_echo = echo;
0405e71f 2130}
2131
2132/*
2133 * Process some terminal data in the course of username/password
2134 * input. Returns >0 for success (line of input returned in
2135 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2136 * for inconclusive (keep waiting for more input please).
2137 */
51470298 2138int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2139{
2140 char c;
2141
2142 while (inlen--) {
2143 switch (c = *in++) {
2144 case 10:
2145 case 13:
51470298 2146 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2147 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2148 return +1;
2149 break;
2150 case 8:
2151 case 127:
51470298 2152 if (ssh->userpass_input_bufpos > 0) {
2153 if (ssh->userpass_input_echo)
2154 c_write_str(ssh, "\b \b");
2155 ssh->userpass_input_bufpos--;
0405e71f 2156 }
2157 break;
2158 case 21:
2159 case 27:
51470298 2160 while (ssh->userpass_input_bufpos > 0) {
2161 if (ssh->userpass_input_echo)
2162 c_write_str(ssh, "\b \b");
2163 ssh->userpass_input_bufpos--;
0405e71f 2164 }
2165 break;
2166 case 3:
2167 case 4:
2168 return -1;
2169 break;
2170 default:
2171 if (((c >= ' ' && c <= '~') ||
2172 ((unsigned char) c >= 160))
51470298 2173 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2174 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2175 if (ssh->userpass_input_echo)
2176 c_write(ssh, &c, 1);
0405e71f 2177 }
2178 break;
2179 }
2180 }
2181 return 0;
2182}
2183
2184/*
fb09bf1c 2185 * Handle the key exchange and user authentication phases.
2186 */
51470298 2187static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2188{
2d466ffd 2189 int i, j;
374330e2 2190 unsigned char cookie[8];
2191 struct RSAKey servkey, hostkey;
2192 struct MD5Context md5c;
51470298 2193 struct do_ssh1_login_state {
2194 int len;
2195 unsigned char *rsabuf, *keystr1, *keystr2;
2196 unsigned long supported_ciphers_mask, supported_auths_mask;
2197 int tried_publickey, tried_agent;
2198 int tis_auth_refused, ccard_auth_refused;
2199 unsigned char session_id[16];
2200 int cipher_type;
2201 char username[100];
2202 void *publickey_blob;
2203 int publickey_bloblen;
2204 char password[100];
2205 char prompt[200];
2206 int pos;
2207 char c;
2208 int pwpkt_type;
2209 unsigned char request[5], *response, *p;
2210 int responselen;
2211 int keyi, nkeys;
2212 int authed;
2213 struct RSAKey key;
2214 Bignum challenge;
2215 char *commentp;
2216 int commentlen;
2217 };
2218 crState(do_ssh1_login_state);
2219
2220 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2221
32874aea 2222 if (!ispkt)
2223 crWaitUntil(ispkt);
374330e2 2224
51470298 2225 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
8d5de777 2226 bombout(("Public key packet not received"));
32874aea 2227 crReturn(0);
8d5de777 2228 }
374330e2 2229
c5e9c988 2230 logevent("Received public keys");
374330e2 2231
51470298 2232 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2233
51470298 2234 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2235 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2236
c5e9c988 2237 /*
1c2a93c4 2238 * Log the host key fingerprint.
c5e9c988 2239 */
c5e9c988 2240 {
2241 char logmsg[80];
1c2a93c4 2242 logevent("Host key fingerprint is:");
c5e9c988 2243 strcpy(logmsg, " ");
32874aea 2244 hostkey.comment = NULL;
2245 rsa_fingerprint(logmsg + strlen(logmsg),
2246 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2247 logevent(logmsg);
2248 }
2249
51470298 2250 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2251 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2252 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2253
51470298 2254 ssh->v1_local_protoflags =
2255 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2256 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2257
c5e9c988 2258 MD5Init(&md5c);
51470298 2259 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2260 MD5Update(&md5c, s->keystr1, servkey.bytes);
2261 MD5Update(&md5c, ssh->pktin.body, 8);
2262 MD5Final(s->session_id, &md5c);
374330e2 2263
32874aea 2264 for (i = 0; i < 32; i++)
51470298 2265 ssh->session_key[i] = random_byte();
374330e2 2266
51470298 2267 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2268
51470298 2269 s->rsabuf = smalloc(s->len);
2270 if (!s->rsabuf)
374330e2 2271 fatalbox("Out of memory");
2272
89ee5268 2273 /*
2274 * Verify the host key.
2275 */
2276 {
32874aea 2277 /*
2278 * First format the key into a string.
2279 */
2280 int len = rsastr_len(&hostkey);
2281 char fingerprint[100];
2282 char *keystr = smalloc(len);
2283 if (!keystr)
2284 fatalbox("Out of memory");
2285 rsastr_fmt(keystr, &hostkey);
2286 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
51470298 2287 verify_ssh_host_key(ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2288 fingerprint);
2289 sfree(keystr);
2290 }
2291
2292 for (i = 0; i < 32; i++) {
51470298 2293 s->rsabuf[i] = ssh->session_key[i];
374330e2 2294 if (i < 16)
51470298 2295 s->rsabuf[i] ^= s->session_id[i];
374330e2 2296 }
2297
2298 if (hostkey.bytes > servkey.bytes) {
51470298 2299 rsaencrypt(s->rsabuf, 32, &servkey);
2300 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2301 } else {
51470298 2302 rsaencrypt(s->rsabuf, 32, &hostkey);
2303 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2304 }
2305
c5e9c988 2306 logevent("Encrypted session key");
2307
ca20bfcf 2308 {
2309 int cipher_chosen = 0, warn = 0;
2310 char *cipher_string = NULL;
51470298 2311 int i;
ca20bfcf 2312 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2313 int next_cipher = cfg.ssh_cipherlist[i];
2314 if (next_cipher == CIPHER_WARN) {
2315 /* If/when we choose a cipher, warn about it */
2316 warn = 1;
2317 } else if (next_cipher == CIPHER_AES) {
2318 /* XXX Probably don't need to mention this. */
2319 logevent("AES not supported in SSH1, skipping");
2320 } else {
2321 switch (next_cipher) {
51470298 2322 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2323 cipher_string = "3DES"; break;
51470298 2324 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2325 cipher_string = "Blowfish"; break;
51470298 2326 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2327 cipher_string = "single-DES"; break;
2328 }
51470298 2329 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2330 cipher_chosen = 1;
2331 }
2332 }
2333 if (!cipher_chosen) {
51470298 2334 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
ca20bfcf 2335 bombout(("Server violates SSH 1 protocol by not "
2336 "supporting 3DES encryption"));
2337 else
2338 /* shouldn't happen */
2339 bombout(("No supported ciphers found"));
a99a05c0 2340 crReturn(0);
2341 }
ca20bfcf 2342
2343 /* Warn about chosen cipher if necessary. */
2344 if (warn)
2345 askcipher(cipher_string, 0);
bea1ef5f 2346 }
ca20bfcf 2347
51470298 2348 switch (s->cipher_type) {
32874aea 2349 case SSH_CIPHER_3DES:
2350 logevent("Using 3DES encryption");
2351 break;
2352 case SSH_CIPHER_DES:
2353 logevent("Using single-DES encryption");
2354 break;
2355 case SSH_CIPHER_BLOWFISH:
2356 logevent("Using Blowfish encryption");
2357 break;
c5e9c988 2358 }
bea1ef5f 2359
51470298 2360 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2361 PKT_CHAR, s->cipher_type,
32874aea 2362 PKT_DATA, cookie, 8,
51470298 2363 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2364 PKT_DATA, s->rsabuf, s->len,
2365 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2366
c5e9c988 2367 logevent("Trying to enable encryption...");
374330e2 2368
51470298 2369 sfree(s->rsabuf);
374330e2 2370
51470298 2371 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2372 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2373 &ssh_3des);
371e569c 2374 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2375 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2376 {
2377 char buf[256];
2378 sprintf(buf, "Initialised %.200s encryption", ssh->cipher->text_name);
2379 logevent(buf);
2380 }
374330e2 2381
0183b242 2382 ssh->crcda_ctx = crcda_make_context();
2383 logevent("Installing CRC compensation attack detector");
2384
fb09bf1c 2385 crWaitUntil(ispkt);
374330e2 2386
51470298 2387 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2388 bombout(("Encryption not successfully enabled"));
32874aea 2389 crReturn(0);
8d5de777 2390 }
374330e2 2391
c5e9c988 2392 logevent("Successfully started encryption");
2393
374330e2 2394 fflush(stdout);
2395 {
67779be7 2396 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2397 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2398 if (!ssh_get_line("login as: ",
51470298 2399 s->username, sizeof(s->username), FALSE)) {
32874aea 2400 /*
2401 * get_line failed to get a username.
2402 * Terminate.
2403 */
2404 logevent("No username provided. Abandoning session.");
51470298 2405 ssh->state = SSH_STATE_CLOSED;
32874aea 2406 crReturn(1);
2407 }
2408 } else {
51470298 2409 int ret; /* need not be kept over crReturn */
2410 c_write_str(ssh, "login as: ");
2411 ssh->send_ok = 1;
0405e71f 2412
51470298 2413 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2414 do {
32874aea 2415 crWaitUntil(!ispkt);
51470298 2416 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2417 } while (ret == 0);
2418 if (ret < 0)
2419 cleanup_exit(0);
51470298 2420 c_write_str(ssh, "\r\n");
32874aea 2421 }
2422 } else {
51470298 2423 strncpy(s->username, cfg.username, sizeof(s->username));
2424 s->username[sizeof(s->username)-1] = '\0';
374330e2 2425 }
fb09bf1c 2426
51470298 2427 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2428 {
51470298 2429 char userlog[22 + sizeof(s->username)];
2430 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2431 logevent(userlog);
32874aea 2432 if (flags & FLAG_INTERACTIVE &&
2433 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2434 strcat(userlog, "\r\n");
51470298 2435 c_write_str(ssh, userlog);
3c8e959b 2436 }
c5e9c988 2437 }
374330e2 2438 }
2439
fb09bf1c 2440 crWaitUntil(ispkt);
374330e2 2441
51470298 2442 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2443 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2444 s->tried_publickey = s->tried_agent = 1;
0df73905 2445 } else {
51470298 2446 s->tried_publickey = s->tried_agent = 0;
0df73905 2447 }
51470298 2448 s->tis_auth_refused = s->ccard_auth_refused = 0;
396778f1 2449 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2450 if (*cfg.keyfile) {
51470298 2451 if (!rsakey_pubblob(cfg.keyfile,
2452 &s->publickey_blob, &s->publickey_bloblen))
2453 s->publickey_blob = NULL;
396778f1 2454 } else
51470298 2455 s->publickey_blob = NULL;
7cca0d81 2456
51470298 2457 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2458 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2459
51470298 2460 if (agent_exists() && !s->tried_agent) {
32874aea 2461 /*
2462 * Attempt RSA authentication using Pageant.
2463 */
32874aea 2464 void *r;
2465
51470298 2466 s->authed = FALSE;
2467 s->tried_agent = 1;
32874aea 2468 logevent("Pageant is running. Requesting keys.");
2469
2470 /* Request the keys held by the agent. */
51470298 2471 PUT_32BIT(s->request, 1);
2472 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2473 agent_query(s->request, 5, &r, &s->responselen);
2474 s->response = (unsigned char *) r;
2475 if (s->response && s->responselen >= 5 &&
2476 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2477 s->p = s->response + 5;
2478 s->nkeys = GET_32BIT(s->p);
2479 s->p += 4;
32874aea 2480 {
2481 char buf[64];
51470298 2482 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2483 logevent(buf);
2484 }
51470298 2485 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2486 {
2487 char buf[64];
51470298 2488 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2489 logevent(buf);
2490 }
51470298 2491 if (s->publickey_blob &&
2492 !memcmp(s->p, s->publickey_blob,
2493 s->publickey_bloblen)) {
396778f1 2494 logevent("This key matches configured key file");
51470298 2495 s->tried_publickey = 1;
396778f1 2496 }
51470298 2497 s->p += 4;
2498 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2499 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2500 s->commentlen = GET_32BIT(s->p);
2501 s->p += 4;
2502 s->commentp = s->p;
2503 s->p += s->commentlen;
2504 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2505 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2506 crWaitUntil(ispkt);
51470298 2507 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2508 logevent("Key refused");
2509 continue;
2510 }
2511 logevent("Received RSA challenge");
51470298 2512 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2513 {
2514 char *agentreq, *q, *ret;
2d466ffd 2515 void *vret;
32874aea 2516 int len, retlen;
2517 len = 1 + 4; /* message type, bit count */
51470298 2518 len += ssh1_bignum_length(s->key.exponent);
2519 len += ssh1_bignum_length(s->key.modulus);
2520 len += ssh1_bignum_length(s->challenge);
32874aea 2521 len += 16; /* session id */
2522 len += 4; /* response format */
2523 agentreq = smalloc(4 + len);
2524 PUT_32BIT(agentreq, len);
2525 q = agentreq + 4;
2526 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2527 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2528 q += 4;
51470298 2529 q += ssh1_write_bignum(q, s->key.exponent);
2530 q += ssh1_write_bignum(q, s->key.modulus);
2531 q += ssh1_write_bignum(q, s->challenge);
2532 memcpy(q, s->session_id, 16);
32874aea 2533 q += 16;
2534 PUT_32BIT(q, 1); /* response format */
2d466ffd 2535 agent_query(agentreq, len + 4, &vret, &retlen);
2536 ret = vret;
32874aea 2537 sfree(agentreq);
2538 if (ret) {
2539 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2540 logevent("Sending Pageant's response");
51470298 2541 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2542 PKT_DATA, ret + 5, 16,
2543 PKT_END);
2544 sfree(ret);
2545 crWaitUntil(ispkt);
51470298 2546 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2547 logevent
2548 ("Pageant's response accepted");
2549 if (flags & FLAG_VERBOSE) {
51470298 2550 c_write_str(ssh, "Authenticated using"
2551 " RSA key \"");
2552 c_write(ssh, s->commentp,
2553 s->commentlen);
2554 c_write_str(ssh, "\" from agent\r\n");
32874aea 2555 }
51470298 2556 s->authed = TRUE;
32874aea 2557 } else
2558 logevent
2559 ("Pageant's response not accepted");
2560 } else {
2561 logevent
2562 ("Pageant failed to answer challenge");
2563 sfree(ret);
2564 }
2565 } else {
2566 logevent("No reply received from Pageant");
2567 }
2568 }
51470298 2569 freebn(s->key.exponent);
2570 freebn(s->key.modulus);
2571 freebn(s->challenge);
2572 if (s->authed)
32874aea 2573 break;
2574 }
2575 }
51470298 2576 if (s->authed)
32874aea 2577 break;
2578 }
51470298 2579 if (*cfg.keyfile && !s->tried_publickey)
2580 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2581
614a20a0 2582 if (cfg.try_tis_auth &&
51470298 2583 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2584 !s->tis_auth_refused) {
2585 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2586 logevent("Requested TIS authentication");
51470298 2587 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2588 crWaitUntil(ispkt);
51470298 2589 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2590 logevent("TIS authentication declined");
2591 if (flags & FLAG_INTERACTIVE)
51470298 2592 c_write_str(ssh, "TIS authentication refused.\r\n");
2593 s->tis_auth_refused = 1;
614a20a0 2594 continue;
32874aea 2595 } else {
51470298 2596 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2597 logevent("Received TIS challenge");
51470298 2598 if (challengelen > sizeof(s->prompt) - 1)
2599 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2600 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2601 /* Prompt heuristic comes from OpenSSH */
51470298 2602 strncpy(s->prompt + challengelen,
2603 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2604 "": "\r\nResponse: ",
51470298 2605 (sizeof s->prompt) - challengelen);
2606 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2607 }
2608 }
614a20a0 2609 if (cfg.try_tis_auth &&
51470298 2610 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2611 !s->ccard_auth_refused) {
2612 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2613 logevent("Requested CryptoCard authentication");
51470298 2614 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2615 crWaitUntil(ispkt);
51470298 2616 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2617 logevent("CryptoCard authentication declined");
51470298 2618 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2619 s->ccard_auth_refused = 1;
614a20a0 2620 continue;
32874aea 2621 } else {
51470298 2622 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2623 logevent("Received CryptoCard challenge");
51470298 2624 if (challengelen > sizeof(s->prompt) - 1)
2625 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2626 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2627 strncpy(s->prompt + challengelen,
2628 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2629 "" : "\r\nResponse: ",
51470298 2630 sizeof(s->prompt) - challengelen);
2631 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2632 }
2633 }
51470298 2634 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2635 sprintf(s->prompt, "%.90s@%.90s's password: ",
2636 s->username, ssh->savedhost);
32874aea 2637 }
51470298 2638 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2639 char *comment = NULL;
231ee168 2640 int type;
2641 char msgbuf[256];
32874aea 2642 if (flags & FLAG_VERBOSE)
51470298 2643 c_write_str(ssh, "Trying public key authentication.\r\n");
231ee168 2644 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2645 logevent(msgbuf);
2646 type = key_type(cfg.keyfile);
2647 if (type != SSH_KEYTYPE_SSH1) {
2648 sprintf(msgbuf, "Key is of wrong type (%s)",
2649 key_type_to_str(type));
2650 logevent(msgbuf);
51470298 2651 c_write_str(ssh, msgbuf);
2652 c_write_str(ssh, "\r\n");
2653 s->tried_publickey = 1;
231ee168 2654 continue;
2655 }
32874aea 2656 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2657 if (flags & FLAG_VERBOSE)
51470298 2658 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2659 goto tryauth;
2660 }
51470298 2661 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2662 sfree(comment);
2663 }
a52f067e 2664
614a20a0 2665 /*
2666 * Show password prompt, having first obtained it via a TIS
2667 * or CryptoCard exchange if we're doing TIS or CryptoCard
2668 * authentication.
2669 */
fa17a66e 2670 if (ssh_get_line) {
51470298 2671 if (!ssh_get_line(s->prompt, s->password,
2672 sizeof(s->password), TRUE)) {
32874aea 2673 /*
2674 * get_line failed to get a password (for example
2675 * because one was supplied on the command line
2676 * which has already failed to work). Terminate.
2677 */
51470298 2678 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2679 PKT_STR, "No more passwords available to try",
2680 PKT_END);
247308b5 2681 logevent("Unable to authenticate");
2bc6a386 2682 connection_fatal("Unable to authenticate");
51470298 2683 ssh->state = SSH_STATE_CLOSED;
32874aea 2684 crReturn(1);
2685 }
fb09bf1c 2686 } else {
614a20a0 2687 /* Prompt may have come from server. We've munged it a bit, so
2688 * we know it to be zero-terminated at least once. */
51470298 2689 int ret; /* need not be saved over crReturn */
2690 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2691 s->pos = 0;
0405e71f 2692
51470298 2693 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2694 do {
32874aea 2695 crWaitUntil(!ispkt);
51470298 2696 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2697 } while (ret == 0);
2698 if (ret < 0)
2699 cleanup_exit(0);
51470298 2700 c_write_str(ssh, "\r\n");
32874aea 2701 }
2702
2703 tryauth:
51470298 2704 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2705 /*
2706 * Try public key authentication with the specified
2707 * key file.
2708 */
51470298 2709 s->tried_publickey = 1;
2710
2711 {
2712 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2713 if (ret == 0) {
2714 c_write_str(ssh, "Couldn't load private key from ");
2715 c_write_str(ssh, cfg.keyfile);
2716 c_write_str(ssh, ".\r\n");
2717 continue; /* go and try password */
2718 }
2719 if (ret == -1) {
2720 c_write_str(ssh, "Wrong passphrase.\r\n");
2721 s->tried_publickey = 0;
2722 continue; /* try again */
2723 }
32874aea 2724 }
2725
2726 /*
2727 * Send a public key attempt.
2728 */
51470298 2729 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2730 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2731
2732 crWaitUntil(ispkt);
51470298 2733 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2734 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2735 continue; /* go and try password */
2736 }
51470298 2737 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2738 bombout(("Bizarre response to offer of public key"));
2739 crReturn(0);
2740 }
32874aea 2741
51470298 2742 {
2743 int i;
2744 unsigned char buffer[32];
2745 Bignum challenge, response;
2746
2747 ssh1_read_bignum(ssh->pktin.body, &challenge);
2748 response = rsadecrypt(challenge, &s->key);
2749 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2750
51470298 2751 for (i = 0; i < 32; i++) {
2752 buffer[i] = bignum_byte(response, 31 - i);
2753 }
2754
2755 MD5Init(&md5c);
2756 MD5Update(&md5c, buffer, 32);
2757 MD5Update(&md5c, s->session_id, 16);
2758 MD5Final(buffer, &md5c);
32874aea 2759
51470298 2760 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2761 PKT_DATA, buffer, 16, PKT_END);
2762
2763 freebn(challenge);
2764 freebn(response);
2765 }
32874aea 2766
2767 crWaitUntil(ispkt);
51470298 2768 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2769 if (flags & FLAG_VERBOSE)
51470298 2770 c_write_str(ssh, "Failed to authenticate with"
2771 " our public key.\r\n");
32874aea 2772 continue; /* go and try password */
51470298 2773 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2774 bombout(("Bizarre response to RSA authentication response"));
32874aea 2775 crReturn(0);
2776 }
2777
2778 break; /* we're through! */
2779 } else {
51470298 2780 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2781 /*
2782 * Defence against traffic analysis: we send a
2783 * whole bunch of packets containing strings of
2784 * different lengths. One of these strings is the
2785 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2786 * The others are all random data in
2787 * SSH1_MSG_IGNORE packets. This way a passive
2788 * listener can't tell which is the password, and
2789 * hence can't deduce the password length.
2790 *
2791 * Anybody with a password length greater than 16
2792 * bytes is going to have enough entropy in their
2793 * password that a listener won't find it _that_
2794 * much help to know how long it is. So what we'll
2795 * do is:
2796 *
2797 * - if password length < 16, we send 15 packets
2798 * containing string lengths 1 through 15
2799 *
2800 * - otherwise, we let N be the nearest multiple
2801 * of 8 below the password length, and send 8
2802 * packets containing string lengths N through
2803 * N+7. This won't obscure the order of
2804 * magnitude of the password length, but it will
2805 * introduce a bit of extra uncertainty.
2806 *
2807 * A few servers (the old 1.2.18 through 1.2.22)
2808 * can't deal with SSH1_MSG_IGNORE. For these
2809 * servers, we need an alternative defence. We make
2810 * use of the fact that the password is interpreted
2811 * as a C string: so we can append a NUL, then some
2812 * random data.
bd358db1 2813 *
2814 * One server (a Cisco one) can deal with neither
2815 * SSH1_MSG_IGNORE _nor_ a padded password string.
2816 * For this server we are left with no defences
2817 * against password length sniffing.
32874aea 2818 */
51470298 2819 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2820 /*
2821 * The server can deal with SSH1_MSG_IGNORE, so
2822 * we can use the primary defence.
2823 */
32874aea 2824 int bottom, top, pwlen, i;
2825 char *randomstr;
2826
51470298 2827 pwlen = strlen(s->password);
32874aea 2828 if (pwlen < 16) {
2829 bottom = 0; /* zero length passwords are OK! :-) */
2830 top = 15;
2831 } else {
2832 bottom = pwlen & ~7;
2833 top = bottom + 7;
2834 }
2835
2836 assert(pwlen >= bottom && pwlen <= top);
2837
2838 randomstr = smalloc(top + 1);
2839
2840 for (i = bottom; i <= top; i++) {
2841 if (i == pwlen)
51470298 2842 defer_packet(ssh, s->pwpkt_type,
2843 PKT_STR, s->password, PKT_END);
32874aea 2844 else {
2845 for (j = 0; j < i; j++) {
2846 do {
2847 randomstr[j] = random_byte();
2848 } while (randomstr[j] == '\0');
2849 }
2850 randomstr[i] = '\0';
51470298 2851 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 2852 PKT_STR, randomstr, PKT_END);
2853 }
2854 }
bd358db1 2855 logevent("Sending password with camouflage packets");
51470298 2856 ssh_pkt_defersend(ssh);
bd358db1 2857 }
51470298 2858 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2859 /*
2860 * The server can't deal with SSH1_MSG_IGNORE
2861 * but can deal with padded passwords, so we
2862 * can use the secondary defence.
2863 */
bd358db1 2864 char string[64];
51470298 2865 char *ss;
bd358db1 2866 int len;
2867
51470298 2868 len = strlen(s->password);
bd358db1 2869 if (len < sizeof(string)) {
51470298 2870 ss = string;
2871 strcpy(string, s->password);
bd358db1 2872 len++; /* cover the zero byte */
2873 while (len < sizeof(string)) {
2874 string[len++] = (char) random_byte();
2875 }
2876 } else {
51470298 2877 ss = s->password;
bd358db1 2878 }
2879 logevent("Sending length-padded password");
51470298 2880 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2881 PKT_DATA, ss, len, PKT_END);
bd358db1 2882 } else {
2883 /*
2884 * The server has _both_
2885 * BUG_CHOKES_ON_SSH1_IGNORE and
2886 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2887 * therefore nothing we can do.
2888 */
2889 int len;
51470298 2890 len = strlen(s->password);
bd358db1 2891 logevent("Sending unpadded password");
51470298 2892 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2893 PKT_DATA, s->password, len, PKT_END);
32874aea 2894 }
2895 } else {
51470298 2896 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 2897 }
2898 }
c5e9c988 2899 logevent("Sent password");
51470298 2900 memset(s->password, 0, strlen(s->password));
fb09bf1c 2901 crWaitUntil(ispkt);
51470298 2902 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2903 if (flags & FLAG_VERBOSE)
51470298 2904 c_write_str(ssh, "Access denied\r\n");
c5e9c988 2905 logevent("Authentication refused");
51470298 2906 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2907 bombout(("Strange packet received, type %d", ssh->pktin.type));
32874aea 2908 crReturn(0);
374330e2 2909 }
2910 }
2911
c5e9c988 2912 logevent("Authentication successful");
2913
fb09bf1c 2914 crFinish(1);
2915}
2916
32874aea 2917void sshfwd_close(struct ssh_channel *c)
2918{
51470298 2919 Ssh ssh = c->ssh;
2920
80e48603 2921 if (c && !c->closes) {
4ed34d25 2922 /*
2923 * If the channel's remoteid is -1, we have sent
2924 * CHANNEL_OPEN for this channel, but it hasn't even been
2925 * acknowledged by the server. So we must set a close flag
2926 * on it now, and then when the server acks the channel
2927 * open, we can close it then.
2928 */
36cac739 2929 if (((int)c->remoteid) != -1) {
51470298 2930 if (ssh->version == 1) {
2931 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 2932 PKT_END);
2933 } else {
51470298 2934 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2935 ssh2_pkt_adduint32(ssh, c->remoteid);
2936 ssh2_pkt_send(ssh);
4ed34d25 2937 }
32874aea 2938 }
0357890f 2939 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2940 if (c->type == CHAN_X11) {
2941 c->u.x11.s = NULL;
d74d141c 2942 logevent("Forwarded X11 connection terminated");
4ed34d25 2943 } else if (c->type == CHAN_SOCKDATA ||
2944 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2945 c->u.pfd.s = NULL;
2946 logevent("Forwarded port closed");
32874aea 2947 }
2948 }
2949}
2950
5471d09a 2951int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2952{
51470298 2953 Ssh ssh = c->ssh;
2954
2955 if (ssh->version == 1) {
2956 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 2957 PKT_INT, c->remoteid,
2958 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2959 /*
2960 * In SSH1 we can return 0 here - implying that forwarded
2961 * connections are never individually throttled - because
2962 * the only circumstance that can cause throttling will be
2963 * the whole SSH connection backing up, in which case
2964 * _everything_ will be throttled as a whole.
2965 */
2966 return 0;
783415f8 2967 } else {
32874aea 2968 ssh2_add_channel_data(c, buf, len);
5471d09a 2969 return ssh2_try_send(c);
2970 }
2971}
2972
2973void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2974{
51470298 2975 Ssh ssh = c->ssh;
2976
2977 if (ssh->version == 1) {
5471d09a 2978 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2979 c->v.v1.throttling = 0;
51470298 2980 ssh1_throttle(ssh, -1);
5471d09a 2981 }
2982 } else {
2983 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2984 }
9c964e85 2985}
2986
51470298 2987static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 2988{
51470298 2989 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 2990
2991 random_init();
2992
51470298 2993 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 2994 crReturnV;
85ee8208 2995 }
51470298 2996 if (ssh->state == SSH_STATE_CLOSED)
32874aea 2997 crReturnV;
fb09bf1c 2998
979310f1 2999 if (cfg.agentfwd && agent_exists()) {
32874aea 3000 logevent("Requesting agent forwarding");
51470298 3001 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3002 do {
3003 crReturnV;
3004 } while (!ispkt);
51470298 3005 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3006 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3007 bombout(("Protocol confusion"));
3008 crReturnV;
51470298 3009 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3010 logevent("Agent forwarding refused");
3011 } else {
3012 logevent("Agent forwarding enabled");
51470298 3013 ssh->agentfwd_enabled = TRUE;
db7d555c 3014 }
dacbd0e8 3015 }
3016
9c964e85 3017 if (cfg.x11_forward) {
32874aea 3018 char proto[20], data[64];
3019 logevent("Requesting X11 forwarding");
3020 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
51470298 3021 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3022 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3023 PKT_STR, proto, PKT_STR, data,
3024 PKT_INT, 0, PKT_END);
3025 } else {
51470298 3026 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3027 PKT_STR, proto, PKT_STR, data, PKT_END);
3028 }
3029 do {
3030 crReturnV;
3031 } while (!ispkt);
51470298 3032 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3033 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3034 bombout(("Protocol confusion"));
3035 crReturnV;
51470298 3036 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3037 logevent("X11 forwarding refused");
3038 } else {
3039 logevent("X11 forwarding enabled");
51470298 3040 ssh->X11_fwd_enabled = TRUE;
9c964e85 3041 }
3042 }
3043
d74d141c 3044 {
9bf696b1 3045 char type;
d74d141c 3046 int n;
a4fc0d74 3047 int sport,dport,sserv,dserv;
d74d141c 3048 char sports[256], dports[256], host[256];
3049 char buf[1024];
a4fc0d74 3050 struct servent *se;
d74d141c 3051
51470298 3052 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3053 /* Add port forwardings. */
51470298 3054 ssh->portfwd_strptr = cfg.portfwd;
3055 while (*ssh->portfwd_strptr) {
3056 type = *ssh->portfwd_strptr++;
d74d141c 3057 n = 0;
51470298 3058 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3059 sports[n++] = *ssh->portfwd_strptr++;
d74d141c 3060 sports[n] = 0;
51470298 3061 if (*ssh->portfwd_strptr == '\t')
3062 ssh->portfwd_strptr++;
d74d141c 3063 n = 0;
51470298 3064 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3065 host[n++] = *ssh->portfwd_strptr++;
d74d141c 3066 host[n] = 0;
51470298 3067 if (*ssh->portfwd_strptr == ':')
3068 ssh->portfwd_strptr++;
d74d141c 3069 n = 0;
51470298 3070 while (*ssh->portfwd_strptr)
3071 dports[n++] = *ssh->portfwd_strptr++;
d74d141c 3072 dports[n] = 0;
51470298 3073 ssh->portfwd_strptr++;
d74d141c 3074 dport = atoi(dports);
a4fc0d74 3075 dserv = 0;
3076 if (dport == 0) {
3077 dserv = 1;
3078 se = getservbyname(dports, NULL);
3079 if (se != NULL) {
3080 dport = ntohs(se->s_port);
3081 } else {
3082 sprintf(buf,
3083 "Service lookup failed for destination port \"%s\"",
3084 dports);
3085 logevent(buf);
3086 }
3087 }
d74d141c 3088 sport = atoi(sports);
a4fc0d74 3089 sserv = 0;
3090 if (sport == 0) {
3091 sserv = 1;
3092 se = getservbyname(sports, NULL);
3093 if (se != NULL) {
3094 sport = ntohs(se->s_port);
3095 } else {
3096 sprintf(buf,
3097 "Service lookup failed for source port \"%s\"",
3098 sports);
3099 logevent(buf);
3100 }
3101 }
d74d141c 3102 if (sport && dport) {
3103 if (type == 'L') {
3104 pfd_addforward(host, dport, sport);
a4fc0d74 3105 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3106 " %s:%.*s%.*s%d%.*s",
3107 sserv ? strlen(sports) : 0, sports,
3108 sserv, "(", sport, sserv, ")",
3109 host,
3110 dserv ? strlen(dports) : 0, dports,
3111 dserv, "(", dport, dserv, ")");
d74d141c 3112 logevent(buf);
3113 } else {
3114 struct ssh_rportfwd *pf;
3115 pf = smalloc(sizeof(*pf));
bc240b21 3116 strcpy(pf->dhost, host);
3117 pf->dport = dport;
51470298 3118 if (add234(ssh->rportfwds, pf) != pf) {
d74d141c 3119 sprintf(buf,
95bc8819 3120 "Duplicate remote port forwarding to %s:%d",
d74d141c 3121 host, dport);
3122 logevent(buf);
bc240b21 3123 sfree(pf);
d74d141c 3124 } else {
a4fc0d74 3125 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3126 " forward to %s:%.*s%.*s%d%.*s",
3127 sserv ? strlen(sports) : 0, sports,
3128 sserv, "(", sport, sserv, ")",
3129 host,
3130 dserv ? strlen(dports) : 0, dports,
3131 dserv, "(", dport, dserv, ")");
d74d141c 3132 logevent(buf);
51470298 3133 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3134 PKT_INT, sport,
3135 PKT_STR, host,
3136 PKT_INT, dport,
3137 PKT_END);
9bf696b1 3138 do {
3139 crReturnV;
3140 } while (!ispkt);
51470298 3141 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3142 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
9bf696b1 3143 bombout(("Protocol confusion"));
3144 crReturnV;
51470298 3145 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3146 c_write_str(ssh, "Server refused port"
3147 " forwarding\r\n");
9bf696b1 3148 }
3149 logevent("Remote port forwarding enabled");
d74d141c 3150 }
3151 }
3152 }
3153 }
3154 }
3155
fef97f43 3156 if (!cfg.nopty) {
51470298 3157 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
32874aea 3158 PKT_STR, cfg.termtype,
51470298 3159 PKT_INT, ssh->term_height,
3160 PKT_INT, ssh->term_width,
32874aea 3161 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3162 ssh->state = SSH_STATE_INTERMED;
32874aea 3163 do {
3164 crReturnV;
3165 } while (!ispkt);
51470298 3166 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3167 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3168 bombout(("Protocol confusion"));
3169 crReturnV;
51470298 3170 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3171 c_write_str(ssh, "Server refused to allocate pty\r\n");
3172 ssh->editing = ssh->echoing = 1;
32874aea 3173 }
c5e9c988 3174 logevent("Allocated pty");
0965bee0 3175 } else {
51470298 3176 ssh->editing = ssh->echoing = 1;
374330e2 3177 }
3178
4ba9b64b 3179 if (cfg.compression) {
51470298 3180 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3181 do {
3182 crReturnV;
3183 } while (!ispkt);
51470298 3184 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3185 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
32874aea 3186 bombout(("Protocol confusion"));
3187 crReturnV;
51470298 3188 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3189 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3190 }
4ba9b64b 3191 logevent("Started compression");
51470298 3192 ssh->v1_compressing = TRUE;
4ba9b64b 3193 zlib_compress_init();
3194 zlib_decompress_init();
3195 }
3196
fd5e5847 3197 /*
3198 * Start the shell or command.
3199 *
3200 * Special case: if the first-choice command is an SSH2
3201 * subsystem (hence not usable here) and the second choice
3202 * exists, we fall straight back to that.
3203 */
3204 {
3205 char *cmd = cfg.remote_cmd_ptr;
3206
3207 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3208 cmd = cfg.remote_cmd_ptr2;
51470298 3209 ssh->fallback_cmd = TRUE;
fd5e5847 3210 }
3211 if (*cmd)
51470298 3212 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3213 else
51470298 3214 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3215 logevent("Started session");
3216 }
374330e2 3217
51470298 3218 ssh->state = SSH_STATE_SESSION;
3219 if (ssh->size_needed)
3220 ssh_size(ssh, ssh->term_width, ssh->term_height);
3221 if (ssh->eof_needed)
3222 ssh_special(ssh, TS_EOF);
374330e2 3223
760e88b2 3224 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
51470298 3225 ssh->send_ok = 1;
3226 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3227 while (1) {
3228 crReturnV;
3229 if (ispkt) {
51470298 3230 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3231 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3232 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3233 int bufsize =
51470298 3234 from_backend(ssh->frontend,
3235 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3236 ssh->pktin.body + 4, len);
3237 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3238 ssh->v1_stdout_throttling = 1;
3239 ssh1_throttle(ssh, +1);
5471d09a 3240 }
51470298 3241 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3242 ssh->state = SSH_STATE_CLOSED;
c5e9c988 3243 logevent("Received disconnect request");
32874aea 3244 crReturnV;
51470298 3245 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3246 /* Remote side is trying to open a channel to talk to our
3247 * X-Server. Give them back a local channel number. */
3248 struct ssh_channel *c;
9c964e85 3249
3250 logevent("Received X11 connect request");
3251 /* Refuse if X11 forwarding is disabled. */
51470298 3252 if (!ssh->X11_fwd_enabled) {
3253 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3254 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3255 logevent("Rejected X11 connect request");
3256 } else {
9c964e85 3257 c = smalloc(sizeof(struct ssh_channel));
51470298 3258 c->ssh = ssh;
9c964e85 3259
32874aea 3260 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3261 logevent("opening X11 forward connection failed");
3262 sfree(c);
51470298 3263 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3264 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3265 PKT_END);
9c964e85 3266 } else {
32874aea 3267 logevent
3268 ("opening X11 forward connection succeeded");
51470298 3269 c->remoteid = GET_32BIT(ssh->pktin.body);
3270 c->localid = alloc_channel_id(ssh);
32874aea 3271 c->closes = 0;
5471d09a 3272 c->v.v1.throttling = 0;
32874aea 3273 c->type = CHAN_X11; /* identify channel type */
51470298 3274 add234(ssh->channels, c);
3275 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3276 PKT_INT, c->remoteid, PKT_INT,
3277 c->localid, PKT_END);
3278 logevent("Opened X11 forward channel");
9c964e85 3279 }
3280 }
51470298 3281 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3282 /* Remote side is trying to open a channel to talk to our
3283 * agent. Give them back a local channel number. */
3284 struct ssh_channel *c;
db7d555c 3285
3286 /* Refuse if agent forwarding is disabled. */
51470298 3287 if (!ssh->agentfwd_enabled) {
3288 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3289 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3290 } else {
dcbde236 3291 c = smalloc(sizeof(struct ssh_channel));
51470298 3292 c->ssh = ssh;
3293 c->remoteid = GET_32BIT(ssh->pktin.body);
3294 c->localid = alloc_channel_id(ssh);
db7d555c 3295 c->closes = 0;
5471d09a 3296 c->v.v1.throttling = 0;
32874aea 3297 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3298 c->u.a.lensofar = 0;
51470298 3299 add234(ssh->channels, c);
3300 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3301 PKT_INT, c->remoteid, PKT_INT, c->localid,
3302 PKT_END);
3303 }
51470298 3304 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3305 /* Remote side is trying to open a channel to talk to a
3306 * forwarded port. Give them back a local channel number. */
3307 struct ssh_channel *c;
3308 struct ssh_rportfwd pf;
3309 int hostsize, port;
3310 char host[256], buf[1024];
3311 char *p, *h, *e;
3312 c = smalloc(sizeof(struct ssh_channel));
51470298 3313 c->ssh = ssh;
d74d141c 3314
51470298 3315 hostsize = GET_32BIT(ssh->pktin.body+4);
3316 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
d74d141c 3317 if (h+1 < host+sizeof(host))
3318 *h++ = *p;
95bc8819 3319 p++;
d74d141c 3320 }
3321 *h = 0;
3322 port = GET_32BIT(p);
3323
bc240b21 3324 strcpy(pf.dhost, host);
3325 pf.dport = port;
d74d141c 3326
51470298 3327 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3328 sprintf(buf, "Rejected remote port open request for %s:%d",
3329 host, port);
3330 logevent(buf);
51470298 3331 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3332 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3333 } else {
3334 sprintf(buf, "Received remote port open request for %s:%d",
3335 host, port);
3336 logevent(buf);
3337 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3338 if (e != NULL) {
3339 char buf[256];
3340 sprintf(buf, "Port open failed: %s", e);
3341 logevent(buf);
3342 sfree(c);
51470298 3343 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3344 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3345 PKT_END);
3346 } else {
51470298 3347 c->remoteid = GET_32BIT(ssh->pktin.body);
3348 c->localid = alloc_channel_id(ssh);
d74d141c 3349 c->closes = 0;
5471d09a 3350 c->v.v1.throttling = 0;
d74d141c 3351 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3352 add234(ssh->channels, c);
3353 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3354 PKT_INT, c->remoteid, PKT_INT,
3355 c->localid, PKT_END);
3356 logevent("Forwarded port opened successfully");
3357 }
3358 }
3359
51470298 3360 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3361 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3362 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3363 struct ssh_channel *c;
3364
51470298 3365 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3366 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3367 c->remoteid = localid;
3368 c->type = CHAN_SOCKDATA;
7781f316 3369 c->v.v1.throttling = 0;
bc240b21 3370 pfd_confirm(c->u.pfd.s);
3371 }
d74d141c 3372
4ed34d25 3373 if (c && c->closes) {
3374 /*
3375 * We have a pending close on this channel,
3376 * which we decided on before the server acked
3377 * the channel open. So now we know the
3378 * remoteid, we can close it again.
3379 */
51470298 3380 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3381 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3382 }
3383
51470298 3384 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3385 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3386 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
724cface 3387 struct ssh_channel *c;
3388
51470298 3389 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3390 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3391 logevent("Forwarded connection refused by server");
3392 pfd_close(c->u.pfd.s);
51470298 3393 del234(ssh->channels, c);
724cface 3394 sfree(c);
3395 }
3396
51470298 3397 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3398 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3399 /* Remote side closes a channel. */
51470298 3400 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3401 struct ssh_channel *c;
51470298 3402 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3403 if (c && ((int)c->remoteid) != -1) {
32874aea 3404 int closetype;
3405 closetype =
51470298 3406 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3407
783415f8 3408 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3409 logevent("Forwarded X11 connection terminated");
9c964e85 3410 assert(c->u.x11.s != NULL);
3411 x11_close(c->u.x11.s);
3412 c->u.x11.s = NULL;
3413 }
d74d141c 3414 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3415 logevent("Forwarded port closed");
3416 assert(c->u.pfd.s != NULL);
3417 pfd_close(c->u.pfd.s);
3418 c->u.pfd.s = NULL;
3419 }
0357890f 3420
3421 c->closes |= (closetype << 2); /* seen this message */
3422 if (!(c->closes & closetype)) {
51470298 3423 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3424 PKT_END);
3425 c->closes |= closetype; /* sent it too */
3426 }
3427
3428 if (c->closes == 15) {
51470298 3429 del234(ssh->channels, c);
32874aea 3430 sfree(c);
3431 }
d0d844c1 3432 } else {
3433 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3434 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3435 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3436 i));
32874aea 3437 }
51470298 3438 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3439 /* Data sent down one of our channels. */
51470298 3440 int i = GET_32BIT(ssh->pktin.body);
3441 int len = GET_32BIT(ssh->pktin.body + 4);
3442 unsigned char *p = ssh->pktin.body + 8;
32874aea 3443 struct ssh_channel *c;
51470298 3444 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3445 if (c) {
5471d09a 3446 int bufsize;
32874aea 3447 switch (c->type) {
3448 case CHAN_X11:
5471d09a 3449 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3450 break;
d74d141c 3451 case CHAN_SOCKDATA:
5471d09a 3452 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3453 break;
32874aea 3454 case CHAN_AGENT:
3455 /* Data for an agent message. Buffer it. */
3456 while (len > 0) {
3457 if (c->u.a.lensofar < 4) {
3458 int l = min(4 - c->u.a.lensofar, len);
3459 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3460 l);
3461 p += l;
3462 len -= l;
3463 c->u.a.lensofar += l;
3464 }
3465 if (c->u.a.lensofar == 4) {
3466 c->u.a.totallen =
3467 4 + GET_32BIT(c->u.a.msglen);
3468 c->u.a.message = smalloc(c->u.a.totallen);
3469 memcpy(c->u.a.message, c->u.a.msglen, 4);
3470 }
3471 if (c->u.a.lensofar >= 4 && len > 0) {
3472 int l =
3473 min(c->u.a.totallen - c->u.a.lensofar,
3474 len);
3475 memcpy(c->u.a.message + c->u.a.lensofar, p,
3476 l);
3477 p += l;
3478 len -= l;
3479 c->u.a.lensofar += l;
3480 }
3481 if (c->u.a.lensofar == c->u.a.totallen) {
3482 void *reply, *sentreply;
3483 int replylen;
3484 agent_query(c->u.a.message,
3485 c->u.a.totallen, &reply,
3486 &replylen);
3487 if (reply)
3488 sentreply = reply;
3489 else {
3490 /* Fake SSH_AGENT_FAILURE. */
3491 sentreply = "\0\0\0\1\5";
3492 replylen = 5;
3493 }
51470298 3494 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3495 PKT_INT, c->remoteid,
3496 PKT_INT, replylen,
3497 PKT_DATA, sentreply, replylen,
3498 PKT_END);
3499 if (reply)
3500 sfree(reply);
3501 sfree(c->u.a.message);
3502 c->u.a.lensofar = 0;
3503 }
3504 }
5471d09a 3505 bufsize = 0; /* agent channels never back up */
32874aea 3506 break;
3507 }
90347b95 3508 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3509 c->v.v1.throttling = 1;
51470298 3510 ssh1_throttle(ssh, +1);
5471d09a 3511 }
32874aea 3512 }
51470298 3513 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3514 /* may be from EXEC_SHELL on some servers */
51470298 3515 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3516 /* may be from EXEC_SHELL on some servers
374330e2 3517 * if no pty is available or in other odd cases. Ignore */
51470298 3518 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3519 char buf[100];
51470298 3520 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3521 sprintf(buf, "Server sent command exit status %d",
51470298 3522 ssh->exitcode);
d8d6c7e5 3523 logevent(buf);
51470298 3524 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3525 /*
3526 * In case `helpful' firewalls or proxies tack
3527 * extra human-readable text on the end of the
3528 * session which we might mistake for another
3529 * encrypted packet, we close the session once
3530 * we've sent EXIT_CONFIRMATION.
3531 */
51470298 3532 ssh->state = SSH_STATE_CLOSED;
4252c9cc 3533 crReturnV;
374330e2 3534 } else {
51470298 3535 bombout(("Strange packet received: type %d", ssh->pktin.type));
32874aea 3536 crReturnV;
374330e2 3537 }
3538 } else {
8df7a775 3539 while (inlen > 0) {
3540 int len = min(inlen, 512);
51470298 3541 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3542 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3543 in += len;
3544 inlen -= len;
3545 }
374330e2 3546 }
3547 }
3548
3549 crFinishV;
3550}
3551
3552/*
e5574168 3553 * Utility routine for decoding comma-separated strings in KEXINIT.
3554 */
32874aea 3555static int in_commasep_string(char *needle, char *haystack, int haylen)
3556{
e5574168 3557 int needlen = strlen(needle);
3558 while (1) {
32874aea 3559 /*
3560 * Is it at the start of the string?
3561 */
3562 if (haylen >= needlen && /* haystack is long enough */
3563 !memcmp(needle, haystack, needlen) && /* initial match */
3564 (haylen == needlen || haystack[needlen] == ',')
3565 /* either , or EOS follows */
3566 )
3567 return 1;
3568 /*
3569 * If not, search for the next comma and resume after that.
3570 * If no comma found, terminate.
3571 */
3572 while (haylen > 0 && *haystack != ',')
3573 haylen--, haystack++;
3574 if (haylen == 0)
3575 return 0;
3576 haylen--, haystack++; /* skip over comma itself */
e5574168 3577 }
3578}
3579
3580/*
d39f364a 3581 * SSH2 key creation method.
3582 */
51470298 3583static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
32874aea 3584 char *keyspace)
3585{
d39f364a 3586 SHA_State s;
3587 /* First 20 bytes. */
3588 SHA_Init(&s);
51470298 3589 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3590 sha_mpint(&s, K);
d39f364a 3591 SHA_Bytes(&s, H, 20);
3592 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3593 SHA_Bytes(&s, sessid, 20);
d39f364a 3594 SHA_Final(&s, keyspace);
3595 /* Next 20 bytes. */
3596 SHA_Init(&s);
51470298 3597 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3598 sha_mpint(&s, K);
d39f364a 3599 SHA_Bytes(&s, H, 20);
3600 SHA_Bytes(&s, keyspace, 20);
32874aea 3601 SHA_Final(&s, keyspace + 20);
d39f364a 3602}
3603
3604/*
7cca0d81 3605 * Handle the SSH2 transport layer.
e5574168 3606 */
51470298 3607static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3608{
51470298 3609 struct do_ssh2_transport_state {
3610 int nbits, pbits, warn;
3611 Bignum p, g, e, f, K;
3612 int kex_init_value, kex_reply_value;
3613 const struct ssh_mac **maclist;
3614 int nmacs;
3615 const struct ssh2_cipher *cscipher_tobe;
3616 const struct ssh2_cipher *sccipher_tobe;
3617 const struct ssh_mac *csmac_tobe;
3618 const struct ssh_mac *scmac_tobe;
3619 const struct ssh_compress *cscomp_tobe;
3620 const struct ssh_compress *sccomp_tobe;
3621 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3622 int hostkeylen, siglen;
3623 void *hkey; /* actual host key */
3624 unsigned char exchange_hash[20];
3625 int n_preferred_ciphers;
3626 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3627 const struct ssh_compress *preferred_comp;
3628 int first_kex;
3629 };
3630 crState(do_ssh2_transport_state);
3631
3632 crBegin(ssh->do_ssh2_transport_crstate);
3633
3634 s->cscipher_tobe = s->sccipher_tobe = NULL;
3635 s->csmac_tobe = s->scmac_tobe = NULL;
3636 s->cscomp_tobe = s->sccomp_tobe = NULL;
3637
7cca0d81 3638 random_init();
51470298 3639 s->first_kex = 1;
e5574168 3640
51470298 3641 {
3642 int i;
3643 /*
3644 * Set up the preferred ciphers. (NULL => warn below here)
3645 */
3646 s->n_preferred_ciphers = 0;
3647 for (i = 0; i < CIPHER_MAX; i++) {
3648 switch (cfg.ssh_cipherlist[i]) {
3649 case CIPHER_BLOWFISH:
3650 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3651 break;
3652 case CIPHER_DES:
3653 if (cfg.ssh2_des_cbc) {
3654 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3655 }
3656 break;
3657 case CIPHER_3DES:
3658 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3659 break;
3660 case CIPHER_AES:
3661 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3662 break;
3663 case CIPHER_WARN:
3664 /* Flag for later. Don't bother if it's the last in
3665 * the list. */
3666 if (i < CIPHER_MAX - 1) {
3667 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3668 }
3669 break;
ca20bfcf 3670 }
ca20bfcf 3671 }
5e8358ad 3672 }
ca20bfcf 3673
3674 /*
3675 * Set up preferred compression.
3676 */
4ba9b64b 3677 if (cfg.compression)
51470298 3678 s->preferred_comp = &ssh_zlib;
4ba9b64b 3679 else
51470298 3680 s->preferred_comp = &ssh_comp_none;
5e8358ad 3681
7591b9ff 3682 /*
3683 * Be prepared to work around the buggy MAC problem.
3684 */
51470298 3685 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3686 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3687 else
51470298 3688 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3689
32874aea 3690 begin_key_exchange:
51470298 3691 {
3692 int i, j, cipherstr_started;
3693
3694 /*
3695 * Construct and send our key exchange packet.
3696 */
3697 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3698 for (i = 0; i < 16; i++)
3699 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3700 /* List key exchange algorithms. */
3701 ssh2_pkt_addstring_start(ssh);
3702 for (i = 0; i < lenof(kex_algs); i++) {
3703 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3704 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3705 continue;
3706 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3707 if (i < lenof(kex_algs) - 1)
3708 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3709 }
51470298 3710 /* List server host key algorithms. */
3711 ssh2_pkt_addstring_start(ssh);
3712 for (i = 0; i < lenof(hostkey_algs); i++) {
3713 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3714 if (i < lenof(hostkey_algs) - 1)
3715 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3716 }
51470298 3717 /* List client->server encryption algorithms. */
3718 ssh2_pkt_addstring_start(ssh);
3719 cipherstr_started = 0;
3720 for (i = 0; i < s->n_preferred_ciphers; i++) {
3721 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3722 if (!c) continue; /* warning flag */
3723 for (j = 0; j < c->nciphers; j++) {
3724 if (cipherstr_started)
3725 ssh2_pkt_addstring_str(ssh, ",");
3726 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3727 cipherstr_started = 1;
3728 }
3729 }
3730 /* List server->client encryption algorithms. */
3731 ssh2_pkt_addstring_start(ssh);
3732 cipherstr_started = 0;
3733 for (i = 0; i < s->n_preferred_ciphers; i++) {
3734 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3735 if (!c) continue; /* warning flag */
3736 for (j = 0; j < c->nciphers; j++) {
3737 if (cipherstr_started)
3738 ssh2_pkt_addstring_str(ssh, ",");
3739 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3740 cipherstr_started = 1;
3741 }
3742 }
3743 /* List client->server MAC algorithms. */
3744 ssh2_pkt_addstring_start(ssh);
3745 for (i = 0; i < s->nmacs; i++) {
3746 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3747 if (i < s->nmacs - 1)
3748 ssh2_pkt_addstring_str(ssh, ",");
3749 }
3750 /* List server->client MAC algorithms. */
3751 ssh2_pkt_addstring_start(ssh);
3752 for (i = 0; i < s->nmacs; i++) {
3753 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3754 if (i < s->nmacs - 1)
3755 ssh2_pkt_addstring_str(ssh, ",");
3756 }
3757 /* List client->server compression algorithms. */
3758 ssh2_pkt_addstring_start(ssh);
3759 for (i = 0; i < lenof(compressions) + 1; i++) {
3760 const struct ssh_compress *c =
3761 i == 0 ? s->preferred_comp : compressions[i - 1];
3762 ssh2_pkt_addstring_str(ssh, c->name);
3763 if (i < lenof(compressions))
3764 ssh2_pkt_addstring_str(ssh, ",");
3765 }
3766 /* List server->client compression algorithms. */
3767 ssh2_pkt_addstring_start(ssh);
3768 for (i = 0; i < lenof(compressions) + 1; i++) {
3769 const struct ssh_compress *c =
3770 i == 0 ? s->preferred_comp : compressions[i - 1];
3771 ssh2_pkt_addstring_str(ssh, c->name);
3772 if (i < lenof(compressions))
3773 ssh2_pkt_addstring_str(ssh, ",");
3774 }
3775 /* List client->server languages. Empty list. */
3776 ssh2_pkt_addstring_start(ssh);
3777 /* List server->client languages. Empty list. */
3778 ssh2_pkt_addstring_start(ssh);
3779 /* First KEX packet does _not_ follow, because we're not that brave. */
3780 ssh2_pkt_addbool(ssh, FALSE);
3781 /* Reserved. */
3782 ssh2_pkt_adduint32(ssh, 0);
e5574168 3783 }
0db56f73 3784
51470298 3785 ssh->exhash = ssh->exhashbase;
3786 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 3787
51470298 3788 ssh2_pkt_send(ssh);
e5574168 3789
32874aea 3790 if (!ispkt)
3791 crWaitUntil(ispkt);
51470298 3792 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 3793
3794 /*
3795 * Now examine the other side's KEXINIT to see what we're up
3796 * to.
3797 */
51470298 3798 {
3799 char *str;
3800 int i, j, len;
3801
3802 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3803 bombout(("expected key exchange packet from server"));
3804 crReturn(0);
32874aea 3805 }
51470298 3806 ssh->kex = NULL;
3807 ssh->hostkey = NULL;
3808 s->cscipher_tobe = NULL;
3809 s->sccipher_tobe = NULL;
3810 s->csmac_tobe = NULL;
3811 s->scmac_tobe = NULL;
3812 s->cscomp_tobe = NULL;
3813 s->sccomp_tobe = NULL;
3814 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3815 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3816 for (i = 0; i < lenof(kex_algs); i++) {
3817 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3818 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3819 continue;
3820 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3821 ssh->kex = kex_algs[i];
3822 break;
3823 }
32874aea 3824 }
51470298 3825 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3826 for (i = 0; i < lenof(hostkey_algs); i++) {
3827 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3828 ssh->hostkey = hostkey_algs[i];
3829 break;
3830 }
3831 }
3832 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3833 s->warn = 0;
3834 for (i = 0; i < s->n_preferred_ciphers; i++) {
3835 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3836 if (!c) {
3837 s->warn = 1;
3838 } else {
3839 for (j = 0; j < c->nciphers; j++) {
3840 if (in_commasep_string(c->list[j]->name, str, len)) {
3841 s->cscipher_tobe = c->list[j];
3842 break;
3843 }
ca20bfcf 3844 }
32874aea 3845 }
51470298 3846 if (s->cscipher_tobe) {
3847 if (s->warn)
3848 askcipher(s->cscipher_tobe->name, 1);
3849 break;
3850 }
32874aea 3851 }
51470298 3852 if (!s->cscipher_tobe) {
3853 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3854 crReturn(0);
ca20bfcf 3855 }
0ef8f407 3856
51470298 3857 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3858 s->warn = 0;
3859 for (i = 0; i < s->n_preferred_ciphers; i++) {
3860 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3861 if (!c) {
3862 s->warn = 1;
3863 } else {
3864 for (j = 0; j < c->nciphers; j++) {
3865 if (in_commasep_string(c->list[j]->name, str, len)) {
3866 s->sccipher_tobe = c->list[j];
3867 break;
3868 }
ca20bfcf 3869 }
32874aea 3870 }
51470298 3871 if (s->sccipher_tobe) {
3872 if (s->warn)
3873 askcipher(s->sccipher_tobe->name, 2);
3874 break;
3875 }
32874aea 3876 }
51470298 3877 if (!s->sccipher_tobe) {
3878 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3879 crReturn(0);
ca20bfcf 3880 }
0ef8f407 3881
51470298 3882 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3883 for (i = 0; i < s->nmacs; i++) {
3884 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3885 s->csmac_tobe = s->maclist[i];
3886 break;
3887 }
32874aea 3888 }
51470298 3889 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3890 for (i = 0; i < s->nmacs; i++) {
3891 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3892 s->scmac_tobe = s->maclist[i];
3893 break;
3894 }
32874aea 3895 }
51470298 3896 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3897 for (i = 0; i < lenof(compressions) + 1; i++) {
3898 const struct ssh_compress *c =
3899 i == 0 ? s->preferred_comp : compressions[i - 1];
3900 if (in_commasep_string(c->name, str, len)) {
3901 s->cscomp_tobe = c;
3902 break;
3903 }
32874aea 3904 }
51470298 3905 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3906 for (i = 0; i < lenof(compressions) + 1; i++) {
3907 const struct ssh_compress *c =
3908 i == 0 ? s->preferred_comp : compressions[i - 1];
3909 if (in_commasep_string(c->name, str, len)) {
3910 s->sccomp_tobe = c;
3911 break;
3912 }
32874aea 3913 }
e5574168 3914 }
e5574168 3915
3916 /*
7bd5a860 3917 * Work out the number of bits of key we will need from the key
3918 * exchange. We start with the maximum key length of either
3919 * cipher...
3920 */
3921 {
32874aea 3922 int csbits, scbits;
7bd5a860 3923
51470298 3924 csbits = s->cscipher_tobe->keylen;
3925 scbits = s->sccipher_tobe->keylen;
3926 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 3927 }
3928 /* The keys only have 160-bit entropy, since they're based on
3929 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 3930 if (s->nbits > 160)
3931 s->nbits = 160;
7bd5a860 3932
3933 /*
a92dd380 3934 * If we're doing Diffie-Hellman group exchange, start by
3935 * requesting a group.
e5574168 3936 */
51470298 3937 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 3938 logevent("Doing Diffie-Hellman group exchange");
51470298 3939 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3940 /*
3941 * Work out how big a DH group we will need to allow that
3942 * much data.
7bd5a860 3943 */
51470298 3944 s->pbits = 512 << ((s->nbits - 1) / 64);
3945 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3946 ssh2_pkt_adduint32(ssh, s->pbits);
3947 ssh2_pkt_send(ssh);
32874aea 3948
3949 crWaitUntil(ispkt);
51470298 3950 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
32874aea 3951 bombout(("expected key exchange group packet from server"));
3952 crReturn(0);
3953 }
51470298 3954 s->p = ssh2_pkt_getmp(ssh);
3955 s->g = ssh2_pkt_getmp(ssh);
3956 dh_setup_group(s->p, s->g);
3957 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3958 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3959 } else {
51470298 3960 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3961 dh_setup_group1();
51470298 3962 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3963 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3964 }
e5574168 3965
a92dd380 3966 logevent("Doing Diffie-Hellman key exchange");
e5574168 3967 /*
a92dd380 3968 * Now generate and send e for Diffie-Hellman.
e5574168 3969 */
51470298 3970 s->e = dh_create_e(s->nbits * 2);
3971 ssh2_pkt_init(ssh, s->kex_init_value);
3972 ssh2_pkt_addmp(ssh, s->e);
3973 ssh2_pkt_send(ssh);
e5574168 3974
3975 crWaitUntil(ispkt);
51470298 3976 if (ssh->pktin.type != s->kex_reply_value) {
32874aea 3977 bombout(("expected key exchange reply packet from server"));
3978 crReturn(0);
7cca0d81 3979 }
51470298 3980 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
3981 s->f = ssh2_pkt_getmp(ssh);
3982 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 3983
51470298 3984 s->K = dh_find_K(s->f);
e5574168 3985
51470298 3986 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
3987 if (ssh->kex == &ssh_diffiehellman_gex) {
3988 sha_uint32(&ssh->exhash, s->pbits);
3989 sha_mpint(&ssh->exhash, s->p);
3990 sha_mpint(&ssh->exhash, s->g);
a92dd380 3991 }
51470298 3992 sha_mpint(&ssh->exhash, s->e);
3993 sha_mpint(&ssh->exhash, s->f);
3994 sha_mpint(&ssh->exhash, s->K);
3995 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 3996
3709bfe9 3997 dh_cleanup();
3998
7cca0d81 3999#if 0
765c4200 4000 debug(("Exchange hash is:\n"));
51470298 4001 dmemdump(s->exchange_hash, 20);
7cca0d81 4002#endif
4003
51470298 4004 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4005 if (!s->hkey ||
4006 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4007 s->exchange_hash, 20)) {
f7259d10 4008 bombout(("Server's host key did not match the signature supplied"));
32874aea 4009 crReturn(0);
8d5de777 4010 }
e5574168 4011
4012 /*
7cca0d81 4013 * Authenticate remote host: verify host key. (We've already
4014 * checked the signature of the exchange hash.)
e5574168 4015 */
51470298 4016 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4017 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4018 verify_ssh_host_key(ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4019 s->keystr, s->fingerprint);
4020 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4021 logevent("Host key fingerprint is:");
51470298 4022 logevent(s->fingerprint);
5e0d7cb8 4023 }
51470298 4024 sfree(s->fingerprint);
4025 sfree(s->keystr);
4026 ssh->hostkey->freekey(s->hkey);
d39f364a 4027
4028 /*
7cca0d81 4029 * Send SSH2_MSG_NEWKEYS.
d39f364a 4030 */
51470298 4031 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4032 ssh2_pkt_send(ssh);
d39f364a 4033
4034 /*
8406eaf9 4035 * Expect SSH2_MSG_NEWKEYS from server.
4036 */
4037 crWaitUntil(ispkt);
51470298 4038 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
8406eaf9 4039 bombout(("expected new-keys packet from server"));
4040 crReturn(0);
4041 }
4042
4043 /*
d39f364a 4044 * Create and initialise session keys.
4045 */
371e569c 4046 if (ssh->cs_cipher_ctx)
4047 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4048 ssh->cscipher = s->cscipher_tobe;
371e569c 4049 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4050
371e569c 4051 if (ssh->sc_cipher_ctx)
4052 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4053 ssh->sccipher = s->sccipher_tobe;
371e569c 4054 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4055
4056 if (ssh->cs_mac_ctx)
4057 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4058 ssh->csmac = s->csmac_tobe;
e0e1a00d 4059 ssh->cs_mac_ctx = ssh->csmac->make_context();
4060
4061 if (ssh->sc_mac_ctx)
4062 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4063 ssh->scmac = s->scmac_tobe;
e0e1a00d 4064 ssh->sc_mac_ctx = ssh->scmac->make_context();
4065
51470298 4066 ssh->cscomp = s->cscomp_tobe;
4067 ssh->sccomp = s->sccomp_tobe;
4068 ssh->cscomp->compress_init();
4069 ssh->sccomp->decompress_init();
d39f364a 4070 /*
5e0d7cb8 4071 * Set IVs after keys. Here we use the exchange hash from the
4072 * _first_ key exchange.
d39f364a 4073 */
51470298 4074 {
4075 unsigned char keyspace[40];
4076 if (s->first_kex)
4077 memcpy(ssh->v2_session_id, s->exchange_hash,
4078 sizeof(s->exchange_hash));
4079 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4080 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4081 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4082 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4083 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4084 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4085 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4086 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4087 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4088 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4089 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4090 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4091 }
371e569c 4092 {
4093 char buf[256];
4094 sprintf(buf, "Initialised %.200s client->server encryption",
4095 ssh->cscipher->text_name);
4096 logevent(buf);
4097 sprintf(buf, "Initialised %.200s server->client encryption",
4098 ssh->sccipher->text_name);
4099 logevent(buf);
4100 }
4101
d39f364a 4102
033b4cef 4103 /*
0db56f73 4104 * If this is the first key exchange phase, we must pass the
4105 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4106 * wants to see it but because it will need time to initialise
4107 * itself before it sees an actual packet. In subsequent key
4108 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4109 * it would only confuse the layer above.
4110 */
51470298 4111 if (!s->first_kex) {
32874aea 4112 crReturn(0);
0db56f73 4113 }
51470298 4114 s->first_kex = 0;
0db56f73 4115
4116 /*
7cca0d81 4117 * Now we're encrypting. Begin returning 1 to the protocol main
4118 * function so that other things can run on top of the
4119 * transport. If we ever see a KEXINIT, we must go back to the
4120 * start.
033b4cef 4121 */
51470298 4122 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4123 crReturn(1);
e96adf72 4124 }
5e0d7cb8 4125 logevent("Server initiated key re-exchange");
7cca0d81 4126 goto begin_key_exchange;
e5574168 4127
4128 crFinish(1);
4129}
4130
7cca0d81 4131/*
783415f8 4132 * Add data to an SSH2 channel output buffer.
4133 */
32874aea 4134static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4135 int len)
4136{
5471d09a 4137 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4138}
4139
4140/*
4141 * Attempt to send data on an SSH2 channel.
4142 */
5471d09a 4143static int ssh2_try_send(struct ssh_channel *c)
32874aea 4144{
51470298 4145 Ssh ssh = c->ssh;
4146
5471d09a 4147 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4148 int len;
4149 void *data;
4150 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4151 if ((unsigned)len > c->v.v2.remwindow)
4152 len = c->v.v2.remwindow;
4153 if ((unsigned)len > c->v.v2.remmaxpkt)
4154 len = c->v.v2.remmaxpkt;
51470298 4155 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4156 ssh2_pkt_adduint32(ssh, c->remoteid);
4157 ssh2_pkt_addstring_start(ssh);
4158 ssh2_pkt_addstring_data(ssh, data, len);
4159 ssh2_pkt_send(ssh);
5471d09a 4160 bufchain_consume(&c->v.v2.outbuffer, len);
4161 c->v.v2.remwindow -= len;
4162 }
4163
4164 /*
4165 * After having sent as much data as we can, return the amount
4166 * still buffered.
4167 */
4168 return bufchain_size(&c->v.v2.outbuffer);
4169}
4170
4171/*
4172 * Potentially enlarge the window on an SSH2 channel.
4173 */
4174static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4175{
51470298 4176 Ssh ssh = c->ssh;
4177
6b69f42e 4178 /*
4179 * Never send WINDOW_ADJUST for a channel that the remote side
4180 * already thinks it's closed; there's no point, since it won't
4181 * be sending any more data anyway.
4182 */
4183 if (c->closes != 0)
4184 return;
4185
5471d09a 4186 if (newwin > c->v.v2.locwindow) {
51470298 4187 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4188 ssh2_pkt_adduint32(ssh, c->remoteid);
4189 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4190 ssh2_pkt_send(ssh);
5471d09a 4191 c->v.v2.locwindow = newwin;
783415f8 4192 }
4193}
4194
4195/*
7cca0d81 4196 * Handle the SSH2 userauth and connection layers.
4197 */
51470298 4198static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4199{
51470298 4200 struct do_ssh2_authconn_state {
4201 enum {
4202 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4203 AUTH_PASSWORD,
4204 AUTH_KEYBOARD_INTERACTIVE
4205 } method;
4206 enum {
4207 AUTH_TYPE_NONE,
4208 AUTH_TYPE_PUBLICKEY,
4209 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4210 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4211 AUTH_TYPE_PASSWORD,
4212 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4213 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4214 } type;
4215 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4216 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4217 int kbd_inter_running;
4218 int we_are_in;
4219 int num_prompts, curr_prompt, echo;
4220 char username[100];
4221 int got_username;
4222 char pwprompt[200];
4223 char password[100];
4224 void *publickey_blob;
4225 int publickey_bloblen;
4226 unsigned char request[5], *response, *p;
4227 int responselen;
4228 int keyi, nkeys;
4229 int authed;
4230 char *pkblob, *alg, *commentp;
4231 int pklen, alglen, commentlen;
4232 int siglen, retlen, len;
4233 char *q, *agentreq, *ret;
4234 int try_send;
4235 };
4236 crState(do_ssh2_authconn_state);
4237
4238 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4239
7cca0d81 4240 /*
4241 * Request userauth protocol, and await a response to it.
4242 */
51470298 4243 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4244 ssh2_pkt_addstring(ssh, "ssh-userauth");
4245 ssh2_pkt_send(ssh);
7cca0d81 4246 crWaitUntilV(ispkt);
51470298 4247 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4248 bombout(("Server refused user authentication protocol"));
4249 crReturnV;
8d5de777 4250 }
7cca0d81 4251
4252 /*
1408a877 4253 * We repeat this whole loop, including the username prompt,
4254 * until we manage a successful authentication. If the user
51470298 4255 * types the wrong _password_, they can be sent back to the
4256 * beginning to try another username, if this is configured on.
4257 * (If they specify a username in the config, they are never
4258 * asked, even if they do give a wrong password.)
1408a877 4259 *
4260 * I think this best serves the needs of
4261 *
4262 * - the people who have no configuration, no keys, and just
4263 * want to try repeated (username,password) pairs until they
4264 * type both correctly
4265 *
4266 * - people who have keys and configuration but occasionally
4267 * need to fall back to passwords
4268 *
4269 * - people with a key held in Pageant, who might not have
4270 * logged in to a particular machine before; so they want to
4271 * type a username, and then _either_ their key will be
4272 * accepted, _or_ they will type a password. If they mistype
4273 * the username they will want to be able to get back and
4274 * retype it!
7cca0d81 4275 */
51470298 4276 s->username[0] = '\0';
4277 s->got_username = FALSE;
1408a877 4278 do {
1408a877 4279 /*
4280 * Get a username.
4281 */
51470298 4282 if (s->got_username && !cfg.change_username) {
5bb641e1 4283 /*
4284 * We got a username last time round this loop, and
4285 * with change_username turned off we don't try to get
4286 * it again.
4287 */
4288 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4289 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4290 if (!ssh_get_line("login as: ",
51470298 4291 s->username, sizeof(s->username), FALSE)) {
32874aea 4292 /*
4293 * get_line failed to get a username.
4294 * Terminate.
4295 */
4296 logevent("No username provided. Abandoning session.");
51470298 4297 ssh->state = SSH_STATE_CLOSED;
32874aea 4298 crReturnV;
4299 }
4300 } else {
51470298 4301 int ret; /* need not be saved across crReturn */
4302 c_write_str(ssh, "login as: ");
4303 ssh->send_ok = 1;
4304 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4305 do {
32874aea 4306 crWaitUntilV(!ispkt);
51470298 4307 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4308 } while (ret == 0);
4309 if (ret < 0)
4310 cleanup_exit(0);
32874aea 4311 }
51470298 4312 c_write_str(ssh, "\r\n");
4313 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4314 } else {
4315 char stuff[200];
51470298 4316 strncpy(s->username, cfg.username, sizeof(s->username));
4317 s->username[sizeof(s->username)-1] = '\0';
65a22376 4318 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
51470298 4319 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4320 c_write_str(ssh, stuff);
7cca0d81 4321 }
4322 }
51470298 4323 s->got_username = TRUE;
7cca0d81 4324
65a22376 4325 /*
1408a877 4326 * Send an authentication request using method "none": (a)
4327 * just in case it succeeds, and (b) so that we know what
4328 * authentication methods we can usefully try next.
65a22376 4329 */
51470298 4330 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4331
4332 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4333 ssh2_pkt_addstring(ssh, s->username);
4334 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4335 ssh2_pkt_addstring(ssh, "none"); /* method */
4336 ssh2_pkt_send(ssh);
4337 s->type = AUTH_TYPE_NONE;
4338 s->gotit = FALSE;
4339 s->we_are_in = FALSE;
4340
4341 s->tried_pubkey_config = FALSE;
4342 s->tried_agent = FALSE;
4343 s->tried_keyb_inter = FALSE;
4344 s->kbd_inter_running = FALSE;
396778f1 4345 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4346 if (*cfg.keyfile) {
231ee168 4347 int keytype;
4348 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4349 keytype = key_type(cfg.keyfile);
51470298 4350 if (keytype == SSH_KEYTYPE_SSH2) {
4351 s->publickey_blob =
4352 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4353 &s->publickey_bloblen);
4354 } else {
231ee168 4355 char msgbuf[256];
4356 logeventf("Unable to use this key file (%s)",
4357 key_type_to_str(keytype));
4358 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4359 cfg.keyfile, key_type_to_str(keytype));
51470298 4360 c_write_str(ssh, msgbuf);
4361 s->publickey_blob = NULL;
231ee168 4362 }
396778f1 4363 } else
51470298 4364 s->publickey_blob = NULL;
65a22376 4365
1408a877 4366 while (1) {
4367 /*
4368 * Wait for the result of the last authentication request.
4369 */
51470298 4370 if (!s->gotit)
1408a877 4371 crWaitUntilV(ispkt);
51470298 4372 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4373 char *banner;
4374 int size;
4375 /*
4376 * Don't show the banner if we're operating in
4377 * non-verbose non-interactive mode. (It's probably
4378 * a script, which means nobody will read the
4379 * banner _anyway_, and moreover the printing of
4380 * the banner will screw up processing on the
4381 * output of (say) plink.)
4382 */
4383 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4384 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4385 if (banner)
51470298 4386 c_write_untrusted(ssh, banner, size);
32874aea 4387 }
1408a877 4388 crWaitUntilV(ispkt);
4389 }
51470298 4390 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4391 logevent("Access granted");
51470298 4392 s->we_are_in = TRUE;
1408a877 4393 break;
4394 }
65a22376 4395
51470298 4396 if (s->kbd_inter_running &&
4397 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4398 /*
45068b27 4399 * This is either a further set-of-prompts packet
4400 * in keyboard-interactive authentication, or it's
4401 * the same one and we came back here with `gotit'
4402 * set. In the former case, we must reset the
4403 * curr_prompt variable.
b3186d64 4404 */
51470298 4405 if (!s->gotit)
4406 s->curr_prompt = 0;
4407 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4408 bombout(("Strange packet received during authentication: type %d",
51470298 4409 ssh->pktin.type));
38c4a8da 4410 crReturnV;
65a22376 4411 }
4412
51470298 4413 s->gotit = FALSE;
65a22376 4414
1408a877 4415 /*
4416 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4417 * we can look at the string in it and know what we can
4418 * helpfully try next.
4419 */
51470298 4420 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4421 char *methods;
4422 int methlen;
51470298 4423 ssh2_pkt_getstring(ssh, &methods, &methlen);
4424 s->kbd_inter_running = FALSE;
4425 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4426 /*
4427 * We have received an unequivocal Access
4428 * Denied. This can translate to a variety of
4429 * messages:
4430 *
4431 * - if we'd just tried "none" authentication,
4432 * it's not worth printing anything at all
4433 *
4434 * - if we'd just tried a public key _offer_,
4435 * the message should be "Server refused our
4436 * key" (or no message at all if the key
4437 * came from Pageant)
4438 *
4439 * - if we'd just tried anything else, the
4440 * message really should be "Access denied".
4441 *
4442 * Additionally, if we'd just tried password
4443 * authentication, we should break out of this
4444 * whole loop so as to go back to the username
4445 * prompt.
4446 */
51470298 4447 if (s->type == AUTH_TYPE_NONE) {
1408a877 4448 /* do nothing */
51470298 4449 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4450 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4451 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4452 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4453 logevent("Server refused public key");
51470298 4454 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4455 /* server declined keyboard-interactive; ignore */
1408a877 4456 } else {
51470298 4457 c_write_str(ssh, "Access denied\r\n");
1408a877 4458 logevent("Access denied");
51470298 4459 if (s->type == AUTH_TYPE_PASSWORD) {
4460 s->we_are_in = FALSE;
1408a877 4461 break;
4462 }
4463 }
4464 } else {
51470298 4465 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4466 logevent("Further authentication required");
4467 }
65a22376 4468
51470298 4469 s->can_pubkey =
32874aea 4470 in_commasep_string("publickey", methods, methlen);
51470298 4471 s->can_passwd =
32874aea 4472 in_commasep_string("password", methods, methlen);
51470298 4473 s->can_keyb_inter = cfg.try_ki_auth &&
761187b6 4474 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4475 }
65a22376 4476
51470298 4477 s->method = 0;
4478 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4479
0405e71f 4480 /*
4481 * Most password/passphrase prompts will be
4482 * non-echoing, so we set this to 0 by default.
4483 * Exception is that some keyboard-interactive prompts
4484 * can be echoing, in which case we'll set this to 1.
4485 */
51470298 4486 s->echo = 0;
0405e71f 4487
51470298 4488 if (!s->method && s->can_pubkey &&
4489 agent_exists() && !s->tried_agent) {
1983e559 4490 /*
4491 * Attempt public-key authentication using Pageant.
4492 */
1983e559 4493 void *r;
51470298 4494 s->authed = FALSE;
1983e559 4495
51470298 4496 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4497 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4498
51470298 4499 s->tried_agent = TRUE;
1983e559 4500
4501 logevent("Pageant is running. Requesting keys.");
4502
4503 /* Request the keys held by the agent. */
51470298 4504 PUT_32BIT(s->request, 1);
4505 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4506 agent_query(s->request, 5, &r, &s->responselen);
4507 s->response = (unsigned char *) r;
4508 if (s->response && s->responselen >= 5 &&
4509 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4510 s->p = s->response + 5;
4511 s->nkeys = GET_32BIT(s->p);
4512 s->p += 4;
32874aea 4513 {
4514 char buf[64];
51470298 4515 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4516 logevent(buf);
4517 }
51470298 4518 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4519 void *vret;
1983e559 4520
32874aea 4521 {
4522 char buf[64];
51470298 4523 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4524 logevent(buf);
4525 }
51470298 4526 s->pklen = GET_32BIT(s->p);
4527 s->p += 4;
4528 if (s->publickey_blob &&
4529 s->pklen == s->publickey_bloblen &&
4530 !memcmp(s->p, s->publickey_blob,
4531 s->publickey_bloblen)) {
396778f1 4532 logevent("This key matches configured key file");
51470298 4533 s->tried_pubkey_config = 1;
396778f1 4534 }
51470298 4535 s->pkblob = s->p;
4536 s->p += s->pklen;
4537 s->alglen = GET_32BIT(s->pkblob);
4538 s->alg = s->pkblob + 4;
4539 s->commentlen = GET_32BIT(s->p);
4540 s->p += 4;
4541 s->commentp = s->p;
4542 s->p += s->commentlen;
4543 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4544 ssh2_pkt_addstring(ssh, s->username);
4545 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4546 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4547 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4548 ssh2_pkt_addstring_start(ssh);
4549 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4550 ssh2_pkt_addstring_start(ssh);
4551 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4552 ssh2_pkt_send(ssh);
1983e559 4553
4554 crWaitUntilV(ispkt);
51470298 4555 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4556 logevent("Key refused");
4557 continue;
4558 }
4559
32874aea 4560 if (flags & FLAG_VERBOSE) {
51470298 4561 c_write_str(ssh, "Authenticating with "
4562 "public key \"");
4563 c_write(ssh, s->commentp, s->commentlen);
4564 c_write_str(ssh, "\" from agent\r\n");
32874aea 4565 }
1983e559 4566
4567 /*
4568 * Server is willing to accept the key.
4569 * Construct a SIGN_REQUEST.
4570 */
51470298 4571 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4572 ssh2_pkt_addstring(ssh, s->username);
4573 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4574 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4575 ssh2_pkt_addbool(ssh, TRUE);
4576 ssh2_pkt_addstring_start(ssh);
4577 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4578 ssh2_pkt_addstring_start(ssh);
4579 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4580
4581 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4582 s->len = 1; /* message type */
4583 s->len += 4 + s->pklen; /* key blob */
4584 s->len += 4 + s->siglen; /* data to sign */
4585 s->len += 4; /* flags */
4586 s->agentreq = smalloc(4 + s->len);
4587 PUT_32BIT(s->agentreq, s->len);
4588 s->q = s->agentreq + 4;
4589 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4590 PUT_32BIT(s->q, s->pklen);
4591 s->q += 4;
4592 memcpy(s->q, s->pkblob, s->pklen);
4593 s->q += s->pklen;
4594 PUT_32BIT(s->q, s->siglen);
4595 s->q += 4;
1983e559 4596 /* Now the data to be signed... */
51470298 4597 PUT_32BIT(s->q, 20);
4598 s->q += 4;
4599 memcpy(s->q, ssh->v2_session_id, 20);
4600 s->q += 20;
4601 memcpy(s->q, ssh->pktout.data + 5,
4602 ssh->pktout.length - 5);
4603 s->q += ssh->pktout.length - 5;
1983e559 4604 /* And finally the (zero) flags word. */
51470298 4605 PUT_32BIT(s->q, 0);
4606 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4607 s->ret = vret;
4608 sfree(s->agentreq);
4609 if (s->ret) {
4610 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4611 logevent("Sending Pageant's response");
51470298 4612 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4613 s->ret + 9,
4614 GET_32BIT(s->ret + 5));
4615 ssh2_pkt_send(ssh);
4616 s->authed = TRUE;
1983e559 4617 break;
4618 } else {
32874aea 4619 logevent
4620 ("Pageant failed to answer challenge");
51470298 4621 sfree(s->ret);
1983e559 4622 }
4623 }
4624 }
51470298 4625 if (s->authed)
1983e559 4626 continue;
4627 }
4628 }
4629
51470298 4630 if (!s->method && s->can_pubkey && s->publickey_blob
4631 && !s->tried_pubkey_config) {
1408a877 4632 unsigned char *pub_blob;
4633 char *algorithm, *comment;
4634 int pub_blob_len;
65a22376 4635
51470298 4636 s->tried_pubkey_config = TRUE;
65a22376 4637
51470298 4638 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4639 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4640
65a22376 4641 /*
1408a877 4642 * Try the public key supplied in the configuration.
4643 *
4644 * First, offer the public blob to see if the server is
4645 * willing to accept it.
65a22376 4646 */
1408a877 4647 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4648 &pub_blob_len);
4649 if (pub_blob) {
51470298 4650 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4651 ssh2_pkt_addstring(ssh, s->username);
4652 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4653 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4654 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4655 ssh2_pkt_addstring(ssh, algorithm);
4656 ssh2_pkt_addstring_start(ssh);
4657 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4658 ssh2_pkt_send(ssh);
32874aea 4659 logevent("Offered public key"); /* FIXME */
1408a877 4660
4661 crWaitUntilV(ispkt);
51470298 4662 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4663 s->gotit = TRUE;
4664 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4665 continue; /* key refused; give up on it */
1408a877 4666 }
65a22376 4667
1408a877 4668 logevent("Offer of public key accepted");
65a22376 4669 /*
1408a877 4670 * Actually attempt a serious authentication using
4671 * the key.
65a22376 4672 */
1408a877 4673 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
51470298 4674 sprintf(s->pwprompt,
32874aea 4675 "Passphrase for key \"%.100s\": ",
4676 comment);
51470298 4677 s->need_pw = TRUE;
1408a877 4678 } else {
51470298 4679 s->need_pw = FALSE;
1408a877 4680 }
51470298 4681 c_write_str(ssh, "Authenticating with public key \"");
4682 c_write_str(ssh, comment);
4683 c_write_str(ssh, "\"\r\n");
4684 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4685 }
1408a877 4686 }
4687
51470298 4688 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4689 s->method = AUTH_KEYBOARD_INTERACTIVE;
4690 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4691 s->tried_keyb_inter = TRUE;
af659722 4692
51470298 4693 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4694 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4695
51470298 4696 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4697 ssh2_pkt_addstring(ssh, s->username);
4698 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4699 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4700 ssh2_pkt_addstring(ssh, ""); /* lang */
4701 ssh2_pkt_addstring(ssh, "");
4702 ssh2_pkt_send(ssh);
af659722 4703
4704 crWaitUntilV(ispkt);
51470298 4705 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4706 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4707 s->gotit = TRUE;
af659722 4708 logevent("Keyboard-interactive authentication refused");
51470298 4709 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4710 continue;
4711 }
4712
51470298 4713 s->kbd_inter_running = TRUE;
4714 s->curr_prompt = 0;
af659722 4715 }
4716
51470298 4717 if (s->kbd_inter_running) {
4718 s->method = AUTH_KEYBOARD_INTERACTIVE;
4719 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4720 s->tried_keyb_inter = TRUE;
af659722 4721
51470298 4722 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4723 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4724
51470298 4725 if (s->curr_prompt == 0) {
45068b27 4726 /*
4727 * We've got a fresh USERAUTH_INFO_REQUEST.
4728 * Display header data, and start going through
4729 * the prompts.
4730 */
4731 char *name, *inst, *lang;
4732 int name_len, inst_len, lang_len;
4733
51470298 4734 ssh2_pkt_getstring(ssh, &name, &name_len);
4735 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4736 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 4737 if (name_len > 0) {
51470298 4738 c_write_untrusted(ssh, name, name_len);
4739 c_write_str(ssh, "\r\n");
45068b27 4740 }
4741 if (inst_len > 0) {
51470298 4742 c_write_untrusted(ssh, inst, inst_len);
4743 c_write_str(ssh, "\r\n");
45068b27 4744 }
51470298 4745 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 4746 }
af659722 4747
45068b27 4748 /*
4749 * If there are prompts remaining in the packet,
4750 * display one and get a response.
4751 */
51470298 4752 if (s->curr_prompt < s->num_prompts) {
45068b27 4753 char *prompt;
4754 int prompt_len;
af659722 4755
51470298 4756 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 4757 if (prompt_len > 0) {
51470298 4758 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4759 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4760 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 4761 } else {
51470298 4762 strcpy(s->pwprompt,
45068b27 4763 "<server failed to send prompt>: ");
4764 }
51470298 4765 s->echo = ssh2_pkt_getbool(ssh);
4766 s->need_pw = TRUE;
45068b27 4767 } else
51470298 4768 s->need_pw = FALSE;
af659722 4769 }
4770
51470298 4771 if (!s->method && s->can_passwd) {
4772 s->method = AUTH_PASSWORD;
4773 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4774 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4775 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4776 ssh->savedhost);
4777 s->need_pw = TRUE;
1408a877 4778 }
4779
51470298 4780 if (s->need_pw) {
fa17a66e 4781 if (ssh_get_line) {
51470298 4782 if (!ssh_get_line(s->pwprompt, s->password,
4783 sizeof(s->password), TRUE)) {
1408a877 4784 /*
fa17a66e 4785 * get_line failed to get a password (for
4786 * example because one was supplied on the
4787 * command line which has already failed to
4788 * work). Terminate.
1408a877 4789 */
51470298 4790 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4791 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4792 ssh2_pkt_addstring(ssh, "No more passwords available"
4793 " to try");
4794 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4795 ssh2_pkt_send(ssh);
247308b5 4796 logevent("Unable to authenticate");
2bc6a386 4797 connection_fatal("Unable to authenticate");
51470298 4798 ssh->state = SSH_STATE_CLOSED;
1408a877 4799 crReturnV;
4800 }
4801 } else {
51470298 4802 int ret; /* need not be saved across crReturn */
4803 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4804 ssh->send_ok = 1;
1408a877 4805
51470298 4806 setup_userpass_input(ssh, s->password,
4807 sizeof(s->password), s->echo);
0405e71f 4808 do {
1408a877 4809 crWaitUntilV(!ispkt);
51470298 4810 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4811 } while (ret == 0);
4812 if (ret < 0)
4813 cleanup_exit(0);
51470298 4814 c_write_str(ssh, "\r\n");
65a22376 4815 }
65a22376 4816 }
65a22376 4817
51470298 4818 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 4819 /*
4820 * We have our passphrase. Now try the actual authentication.
4821 */
4822 struct ssh2_userkey *key;
65a22376 4823
51470298 4824 key = ssh2_load_userkey(cfg.keyfile, s->password);
1408a877 4825 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4826 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 4827 c_write_str(ssh, "Wrong passphrase\r\n");
4828 s->tried_pubkey_config = FALSE;
1408a877 4829 } else {
51470298 4830 c_write_str(ssh, "Unable to load private key\r\n");
4831 s->tried_pubkey_config = TRUE;
1408a877 4832 }
4833 /* Send a spurious AUTH_NONE to return to the top. */
51470298 4834 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4835 ssh2_pkt_addstring(ssh, s->username);
4836 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4837 ssh2_pkt_addstring(ssh, "none"); /* method */
4838 ssh2_pkt_send(ssh);
4839 s->type = AUTH_TYPE_NONE;
1408a877 4840 } else {
1dd353b5 4841 unsigned char *pkblob, *sigblob, *sigdata;
4842 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4843
1408a877 4844 /*
4845 * We have loaded the private key and the server
4846 * has announced that it's willing to accept it.
4847 * Hallelujah. Generate a signature and send it.
4848 */
51470298 4849 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4850 ssh2_pkt_addstring(ssh, s->username);
4851 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4852 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4853 ssh2_pkt_addbool(ssh, TRUE);
4854 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 4855 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 4856 ssh2_pkt_addstring_start(ssh);
4857 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
1408a877 4858
4859 /*
4860 * The data to be signed is:
4861 *
4862 * string session-id
4863 *
4864 * followed by everything so far placed in the
4865 * outgoing packet.
4866 */
51470298 4867 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
1408a877 4868 sigdata = smalloc(sigdata_len);
4869 PUT_32BIT(sigdata, 20);
51470298 4870 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4871 memcpy(sigdata + 24, ssh->pktout.data + 5,
4872 ssh->pktout.length - 5);
1dd353b5 4873 sigblob = key->alg->sign(key->data, sigdata,
4874 sigdata_len, &sigblob_len);
51470298 4875 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 4876 sigblob, sigblob_len);
4877 sfree(pkblob);
4878 sfree(sigblob);
1408a877 4879 sfree(sigdata);
4880
51470298 4881 ssh2_pkt_send(ssh);
4882 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 4883 }
51470298 4884 } else if (s->method == AUTH_PASSWORD) {
65a22376 4885 /*
1408a877 4886 * We send the password packet lumped tightly together with
4887 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4888 * string long enough to make the total length of the two
4889 * packets constant. This should ensure that a passive
4890 * listener doing traffic analyis can't work out the length
4891 * of the password.
4892 *
4893 * For this to work, we need an assumption about the
4894 * maximum length of the password packet. I think 256 is
4895 * pretty conservative. Anyone using a password longer than
4896 * that probably doesn't have much to worry about from
4897 * people who find out how long their password is!
65a22376 4898 */
51470298 4899 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4900 ssh2_pkt_addstring(ssh, s->username);
4901 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4902 ssh2_pkt_addstring(ssh, "password");
4903 ssh2_pkt_addbool(ssh, FALSE);
4904 ssh2_pkt_addstring(ssh, s->password);
4905 ssh2_pkt_defer(ssh);
65a22376 4906 /*
1408a877 4907 * We'll include a string that's an exact multiple of the
4908 * cipher block size. If the cipher is NULL for some
4909 * reason, we don't do this trick at all because we gain
4910 * nothing by it.
65a22376 4911 */
51470298 4912 if (ssh->cscipher) {
32874aea 4913 int stringlen, i;
4914
51470298 4915 stringlen = (256 - ssh->deferred_len);
4916 stringlen += ssh->cscipher->blksize - 1;
4917 stringlen -= (stringlen % ssh->cscipher->blksize);
4918 if (ssh->cscomp) {
32874aea 4919 /*
4920 * Temporarily disable actual compression,
4921 * so we can guarantee to get this string
4922 * exactly the length we want it. The
4923 * compression-disabling routine should
4924 * return an integer indicating how many
4925 * bytes we should adjust our string length
4926 * by.
4927 */
51470298 4928 stringlen -= ssh->cscomp->disable_compression();
32874aea 4929 }
51470298 4930 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4931 ssh2_pkt_addstring_start(ssh);
6e9e9520 4932 for (i = 0; i < stringlen; i++) {
32874aea 4933 char c = (char) random_byte();
51470298 4934 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 4935 }
51470298 4936 ssh2_pkt_defer(ssh);
65a22376 4937 }
51470298 4938 ssh_pkt_defersend(ssh);
0d43337a 4939 logevent("Sent password");
51470298 4940 s->type = AUTH_TYPE_PASSWORD;
4941 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4942 if (s->curr_prompt == 0) {
4943 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4944 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 4945 }
51470298 4946 if (s->need_pw) { /* only add pw if we just got one! */
4947 ssh2_pkt_addstring(ssh, s->password);
4948 memset(s->password, 0, sizeof(s->password));
4949 s->curr_prompt++;
45068b27 4950 }
51470298 4951 if (s->curr_prompt >= s->num_prompts) {
4952 ssh2_pkt_send(ssh);
45068b27 4953 } else {
4954 /*
4955 * If there are prompts remaining, we set
4956 * `gotit' so that we won't attempt to get
4957 * another packet. Then we go back round the
4958 * loop and will end up retrieving another
4959 * prompt out of the existing packet. Funky or
4960 * what?
4961 */
51470298 4962 s->gotit = TRUE;
45068b27 4963 }
51470298 4964 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4965 } else {
51470298 4966 c_write_str(ssh, "No supported authentication methods"
4967 " left to try!\r\n");
4968 logevent("No supported authentications offered."
4969 " Disconnecting");
4970 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4971 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
4972 ssh2_pkt_addstring(ssh, "No supported authentication"
4973 " methods available");
4974 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4975 ssh2_pkt_send(ssh);
4976 ssh->state = SSH_STATE_CLOSED;
1408a877 4977 crReturnV;
65a22376 4978 }
65a22376 4979 }
51470298 4980 } while (!s->we_are_in);
7cca0d81 4981
4982 /*
4983 * Now we're authenticated for the connection protocol. The
4984 * connection protocol will automatically have started at this
4985 * point; there's no need to send SERVICE_REQUEST.
4986 */
4987
4988 /*
4989 * So now create a channel with a session in it.
4990 */
51470298 4991 ssh->channels = newtree234(ssh_channelcmp);
4992 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
4993 ssh->mainchan->ssh = ssh;
4994 ssh->mainchan->localid = alloc_channel_id(ssh);
4995 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
4996 ssh2_pkt_addstring(ssh, "session");
4997 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
4998 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4999 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5000 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5001 ssh2_pkt_send(ssh);
7cca0d81 5002 crWaitUntilV(ispkt);
51470298 5003 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 5004 bombout(("Server refused to open a session"));
5005 crReturnV;
5006 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5007 }
51470298 5008 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
32874aea 5009 bombout(("Server's channel confirmation cited wrong channel"));
5010 crReturnV;
7cca0d81 5011 }
51470298 5012 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5013 ssh->mainchan->type = CHAN_MAINSESSION;
5014 ssh->mainchan->closes = 0;
5015 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5016 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5017 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5018 add234(ssh->channels, ssh->mainchan);
7cca0d81 5019 logevent("Opened channel for session");
5020
5021 /*
783415f8 5022 * Potentially enable X11 forwarding.
5023 */
5024 if (cfg.x11_forward) {
32874aea 5025 char proto[20], data[64];
5026 logevent("Requesting X11 forwarding");
5027 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
51470298 5028 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5029 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5030 ssh2_pkt_addstring(ssh, "x11-req");
5031 ssh2_pkt_addbool(ssh, 1); /* want reply */
5032 ssh2_pkt_addbool(ssh, 0); /* many connections */
5033 ssh2_pkt_addstring(ssh, proto);
5034 ssh2_pkt_addstring(ssh, data);
5035 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5036 ssh2_pkt_send(ssh);
32874aea 5037
5038 do {
5039 crWaitUntilV(ispkt);
51470298 5040 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5041 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5042 struct ssh_channel *c;
51470298 5043 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5044 if (!c)
5045 continue; /* nonexistent channel */
51470298 5046 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5047 }
51470298 5048 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5049
51470298 5050 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5051 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5052 bombout(("Unexpected response to X11 forwarding request:"
51470298 5053 " packet type %d", ssh->pktin.type));
32874aea 5054 crReturnV;
5055 }
5056 logevent("X11 forwarding refused");
5057 } else {
5058 logevent("X11 forwarding enabled");
51470298 5059 ssh->X11_fwd_enabled = TRUE;
32874aea 5060 }
783415f8 5061 }
5062
5063 /*
bc240b21 5064 * Enable port forwardings.
5065 */
5066 {
bc240b21 5067 char type;
5068 int n;
a4fc0d74 5069 int sport,dport,sserv,dserv;
bc240b21 5070 char sports[256], dports[256], host[256];
5071 char buf[1024];
a4fc0d74 5072 struct servent *se;
bc240b21 5073
51470298 5074 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5075 /* Add port forwardings. */
51470298 5076 ssh->portfwd_strptr = cfg.portfwd;
5077 while (*ssh->portfwd_strptr) {
5078 type = *ssh->portfwd_strptr++;
bc240b21 5079 n = 0;
51470298 5080 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5081 sports[n++] = *ssh->portfwd_strptr++;
bc240b21 5082 sports[n] = 0;
51470298 5083 if (*ssh->portfwd_strptr == '\t')
5084 ssh->portfwd_strptr++;
bc240b21 5085 n = 0;
51470298 5086 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5087 host[n++] = *ssh->portfwd_strptr++;
bc240b21 5088 host[n] = 0;
51470298 5089 if (*ssh->portfwd_strptr == ':')
5090 ssh->portfwd_strptr++;
bc240b21 5091 n = 0;
51470298 5092 while (*ssh->portfwd_strptr)
5093 dports[n++] = *ssh->portfwd_strptr++;
bc240b21 5094 dports[n] = 0;
51470298 5095 ssh->portfwd_strptr++;
bc240b21 5096 dport = atoi(dports);
a4fc0d74 5097 dserv = 0;
5098 if (dport == 0) {
5099 dserv = 1;
5100 se = getservbyname(dports, NULL);
5101 if (se != NULL) {
5102 dport = ntohs(se->s_port);
5103 } else {
5104 sprintf(buf,
5105 "Service lookup failed for destination port \"%s\"",
5106 dports);
5107 logevent(buf);
5108 }
5109 }
bc240b21 5110 sport = atoi(sports);
a4fc0d74 5111 sserv = 0;
5112 if (sport == 0) {
5113 sserv = 1;
5114 se = getservbyname(sports, NULL);
5115 if (se != NULL) {
5116 sport = ntohs(se->s_port);
5117 } else {
5118 sprintf(buf,
5119 "Service lookup failed for source port \"%s\"",
5120 sports);
5121 logevent(buf);
5122 }
5123 }
bc240b21 5124 if (sport && dport) {
5125 if (type == 'L') {
5126 pfd_addforward(host, dport, sport);
a4fc0d74 5127 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5128 " %s:%.*s%.*s%d%.*s",
5129 sserv ? strlen(sports) : 0, sports,
5130 sserv, "(", sport, sserv, ")",
5131 host,
5132 dserv ? strlen(dports) : 0, dports,
5133 dserv, "(", dport, dserv, ")");
bc240b21 5134 logevent(buf);
5135 } else {
5136 struct ssh_rportfwd *pf;
5137 pf = smalloc(sizeof(*pf));
5138 strcpy(pf->dhost, host);
5139 pf->dport = dport;
5140 pf->sport = sport;
51470298 5141 if (add234(ssh->rportfwds, pf) != pf) {
bc240b21 5142 sprintf(buf,
95bc8819 5143 "Duplicate remote port forwarding to %s:%d",
bc240b21 5144 host, dport);
5145 logevent(buf);
5146 sfree(pf);
5147 } else {
a4fc0d74 5148 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5149 " forward to %s:%.*s%.*s%d%.*s",
5150 sserv ? strlen(sports) : 0, sports,
5151 sserv, "(", sport, sserv, ")",
5152 host,
5153 dserv ? strlen(dports) : 0, dports,
5154 dserv, "(", dport, dserv, ")");
bc240b21 5155 logevent(buf);
51470298 5156 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5157 ssh2_pkt_addstring(ssh, "tcpip-forward");
5158 ssh2_pkt_addbool(ssh, 1);/* want reply */
beefa433 5159 if (cfg.rport_acceptall)
51470298 5160 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5161 else
51470298 5162 ssh2_pkt_addstring(ssh, "127.0.0.1");
5163 ssh2_pkt_adduint32(ssh, sport);
5164 ssh2_pkt_send(ssh);
bc240b21 5165
5166 do {
5167 crWaitUntilV(ispkt);
51470298 5168 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5169 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5170 struct ssh_channel *c;
51470298 5171 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5172 if (!c)
5173 continue;/* nonexistent channel */
51470298 5174 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5175 }
51470298 5176 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5177
51470298 5178 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5179 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5180 bombout(("Unexpected response to port "
5181 "forwarding request: packet type %d",
51470298 5182 ssh->pktin.type));
bc240b21 5183 crReturnV;
5184 }
5185 logevent("Server refused this port forwarding");
5186 } else {
5187 logevent("Remote port forwarding enabled");
5188 }
5189 }
5190 }
5191 }
5192 }
5193 }
5194
5195 /*
36c2a3e9 5196 * Potentially enable agent forwarding.
5197 */
5198 if (cfg.agentfwd && agent_exists()) {
32874aea 5199 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5200 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5201 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5202 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5203 ssh2_pkt_addbool(ssh, 1); /* want reply */
5204 ssh2_pkt_send(ssh);
32874aea 5205
5206 do {
5207 crWaitUntilV(ispkt);
51470298 5208 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5209 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5210 struct ssh_channel *c;
51470298 5211 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5212 if (!c)
5213 continue; /* nonexistent channel */
51470298 5214 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5215 }
51470298 5216 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5217
51470298 5218 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5219 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5220 bombout(("Unexpected response to agent forwarding request:"
51470298 5221 " packet type %d", ssh->pktin.type));
32874aea 5222 crReturnV;
5223 }
5224 logevent("Agent forwarding refused");
5225 } else {
5226 logevent("Agent forwarding enabled");
51470298 5227 ssh->agentfwd_enabled = TRUE;
32874aea 5228 }
36c2a3e9 5229 }
5230
5231 /*
7cca0d81 5232 * Now allocate a pty for the session.
5233 */
67779be7 5234 if (!cfg.nopty) {
51470298 5235 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5236 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5237 ssh2_pkt_addstring(ssh, "pty-req");
5238 ssh2_pkt_addbool(ssh, 1); /* want reply */
5239 ssh2_pkt_addstring(ssh, cfg.termtype);
5240 ssh2_pkt_adduint32(ssh, ssh->term_width);
5241 ssh2_pkt_adduint32(ssh, ssh->term_height);
5242 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5243 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5244 ssh2_pkt_addstring_start(ssh);
5245 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5246 ssh2_pkt_send(ssh);
5247 ssh->state = SSH_STATE_INTERMED;
32874aea 5248
5249 do {
5250 crWaitUntilV(ispkt);
51470298 5251 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5252 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5253 struct ssh_channel *c;
51470298 5254 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5255 if (!c)
5256 continue; /* nonexistent channel */
51470298 5257 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5258 }
51470298 5259 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5260
51470298 5261 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5262 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5263 bombout(("Unexpected response to pty request:"
51470298 5264 " packet type %d", ssh->pktin.type));
32874aea 5265 crReturnV;
5266 }
51470298 5267 c_write_str(ssh, "Server refused to allocate pty\r\n");
5268 ssh->editing = ssh->echoing = 1;
32874aea 5269 } else {
5270 logevent("Allocated pty");
5271 }
0965bee0 5272 } else {
51470298 5273 ssh->editing = ssh->echoing = 1;
7cca0d81 5274 }
5275
5276 /*
fd5e5847 5277 * Start a shell or a remote command. We may have to attempt
5278 * this twice if the config data has provided a second choice
5279 * of command.
7cca0d81 5280 */
fd5e5847 5281 while (1) {
5282 int subsys;
5283 char *cmd;
5284
51470298 5285 if (ssh->fallback_cmd) {
fd5e5847 5286 subsys = cfg.ssh_subsys2;
5287 cmd = cfg.remote_cmd_ptr2;
5288 } else {
5289 subsys = cfg.ssh_subsys;
5290 cmd = cfg.remote_cmd_ptr;
5291 }
5292
51470298 5293 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5294 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5295 if (subsys) {
51470298 5296 ssh2_pkt_addstring(ssh, "subsystem");
5297 ssh2_pkt_addbool(ssh, 1); /* want reply */
5298 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5299 } else if (*cmd) {
51470298 5300 ssh2_pkt_addstring(ssh, "exec");
5301 ssh2_pkt_addbool(ssh, 1); /* want reply */
5302 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5303 } else {
51470298 5304 ssh2_pkt_addstring(ssh, "shell");
5305 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5306 }
51470298 5307 ssh2_pkt_send(ssh);
fd5e5847 5308 do {
5309 crWaitUntilV(ispkt);
51470298 5310 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5311 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5312 struct ssh_channel *c;
51470298 5313 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5314 if (!c)
5315 continue; /* nonexistent channel */
51470298 5316 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5317 }
51470298 5318 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5319 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5320 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5321 bombout(("Unexpected response to shell/command request:"
51470298 5322 " packet type %d", ssh->pktin.type));
fd5e5847 5323 crReturnV;
5324 }
5325 /*
5326 * We failed to start the command. If this is the
5327 * fallback command, we really are finished; if it's
5328 * not, and if the fallback command exists, try falling
5329 * back to it before complaining.
5330 */
51470298 5331 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5332 logevent("Primary command failed; attempting fallback");
51470298 5333 ssh->fallback_cmd = TRUE;
fd5e5847 5334 continue;
5335 }
5336 bombout(("Server refused to start a shell/command"));
32874aea 5337 crReturnV;
fd5e5847 5338 } else {
5339 logevent("Started a shell/command");
32874aea 5340 }
fd5e5847 5341 break;
7cca0d81 5342 }
5343
51470298 5344 ssh->state = SSH_STATE_SESSION;
5345 if (ssh->size_needed)
5346 ssh_size(ssh, ssh->term_width, ssh->term_height);
5347 if (ssh->eof_needed)
5348 ssh_special(ssh, TS_EOF);
6e48c3fe 5349
7cca0d81 5350 /*
5351 * Transfer data!
5352 */
760e88b2 5353 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
51470298 5354 ssh->send_ok = 1;
7cca0d81 5355 while (1) {
e5574168 5356 crReturnV;
51470298 5357 s->try_send = FALSE;
7cca0d81 5358 if (ispkt) {
51470298 5359 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5360 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5361 char *data;
5362 int length;
51470298 5363 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5364 struct ssh_channel *c;
51470298 5365 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5366 if (!c)
5367 continue; /* nonexistent channel */
51470298 5368 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5369 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5370 continue; /* extended but not stderr */
51470298 5371 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5372 if (data) {
5471d09a 5373 int bufsize;
5374 c->v.v2.locwindow -= length;
32874aea 5375 switch (c->type) {
5376 case CHAN_MAINSESSION:
5471d09a 5377 bufsize =
51470298 5378 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5379 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5380 data, length);
32874aea 5381 break;
5382 case CHAN_X11:
5471d09a 5383 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5384 break;
d74d141c 5385 case CHAN_SOCKDATA:
5471d09a 5386 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5387 break;
36c2a3e9 5388 case CHAN_AGENT:
32874aea 5389 while (length > 0) {
5390 if (c->u.a.lensofar < 4) {
5391 int l = min(4 - c->u.a.lensofar, length);
5392 memcpy(c->u.a.msglen + c->u.a.lensofar,
5393 data, l);
5394 data += l;
5395 length -= l;
5396 c->u.a.lensofar += l;
5397 }
5398 if (c->u.a.lensofar == 4) {
5399 c->u.a.totallen =
5400 4 + GET_32BIT(c->u.a.msglen);
5401 c->u.a.message = smalloc(c->u.a.totallen);
5402 memcpy(c->u.a.message, c->u.a.msglen, 4);
5403 }
5404 if (c->u.a.lensofar >= 4 && length > 0) {
5405 int l =
5406 min(c->u.a.totallen - c->u.a.lensofar,
5407 length);
5408 memcpy(c->u.a.message + c->u.a.lensofar,
5409 data, l);
5410 data += l;
5411 length -= l;
5412 c->u.a.lensofar += l;
5413 }
5414 if (c->u.a.lensofar == c->u.a.totallen) {
5415 void *reply, *sentreply;
5416 int replylen;
5417 agent_query(c->u.a.message,
5418 c->u.a.totallen, &reply,
5419 &replylen);
5420 if (reply)
5421 sentreply = reply;
5422 else {
5423 /* Fake SSH_AGENT_FAILURE. */
5424 sentreply = "\0\0\0\1\5";
5425 replylen = 5;
5426 }
51470298 5427 ssh2_add_channel_data(c, sentreply, replylen);
5428 s->try_send = TRUE;
32874aea 5429 if (reply)
5430 sfree(reply);
5431 sfree(c->u.a.message);
5432 c->u.a.lensofar = 0;
5433 }
5434 }
5471d09a 5435 bufsize = 0;
32874aea 5436 break;
5437 }
5438 /*
5471d09a 5439 * If we are not buffering too much data,
5440 * enlarge the window again at the remote side.
32874aea 5441 */
5471d09a 5442 if (bufsize < OUR_V2_WINSIZE)
5443 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5444 }
51470298 5445 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5446 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5447 struct ssh_channel *c;
5448
51470298 5449 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5450 if (!c)
5451 continue; /* nonexistent channel */
5452
5453 if (c->type == CHAN_X11) {
5454 /*
5455 * Remote EOF on an X11 channel means we should
5456 * wrap up and close the channel ourselves.
5457 */
5458 x11_close(c->u.x11.s);
5459 sshfwd_close(c);
5460 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5461 sshfwd_close(c);
d74d141c 5462 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5463 pfd_close(c->u.pfd.s);
5464 sshfwd_close(c);
36c2a3e9 5465 }
51470298 5466 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5467 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5468 struct ssh_channel *c;
5469
51470298 5470 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5471 if (!c || ((int)c->remoteid) == -1) {
5472 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5473 c ? "half-open" : "nonexistent", i));
5474 }
32874aea 5475 /* Do pre-close processing on the channel. */
5476 switch (c->type) {
5477 case CHAN_MAINSESSION:
5478 break; /* nothing to see here, move along */
5479 case CHAN_X11:
92f157bd 5480 if (c->u.x11.s != NULL)
5481 x11_close(c->u.x11.s);
5482 sshfwd_close(c);
32874aea 5483 break;
5484 case CHAN_AGENT:
92f157bd 5485 sshfwd_close(c);
32874aea 5486 break;
d74d141c 5487 case CHAN_SOCKDATA:
92f157bd 5488 if (c->u.pfd.s != NULL)
5489 pfd_close(c->u.pfd.s);
5490 sshfwd_close(c);
bc240b21 5491 break;
32874aea 5492 }
92f157bd 5493 if (c->closes == 0) {
51470298 5494 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5495 ssh2_pkt_adduint32(ssh, c->remoteid);
5496 ssh2_pkt_send(ssh);
92f157bd 5497 }
51470298 5498 del234(ssh->channels, c);
5471d09a 5499 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5500 sfree(c);
5501
5502 /*
5503 * See if that was the last channel left open.
5504 */
51470298 5505 if (count234(ssh->channels) == 0) {
ca2914d1 5506#if 0
5507 /*
5508 * We used to send SSH_MSG_DISCONNECT here,
5509 * because I'd believed that _every_ conforming
5510 * SSH2 connection had to end with a disconnect
5511 * being sent by at least one side; apparently
5512 * I was wrong and it's perfectly OK to
5513 * unceremoniously slam the connection shut
5514 * when you're done, and indeed OpenSSH feels
5515 * this is more polite than sending a
5516 * DISCONNECT. So now we don't.
5517 */
32874aea 5518 logevent("All channels closed. Disconnecting");
51470298 5519 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5520 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5521 ssh2_pkt_addstring(ssh, "All open channels closed");
5522 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5523 ssh2_pkt_send(ssh);
ca2914d1 5524#endif
51470298 5525 ssh->state = SSH_STATE_CLOSED;
32874aea 5526 crReturnV;
5527 }
5528 continue; /* remote sends close; ignore (FIXME) */
51470298 5529 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5530 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5531 struct ssh_channel *c;
51470298 5532 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5533 if (!c)
5534 continue; /* nonexistent channel */
51470298 5535 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5536 s->try_send = TRUE;
5537 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5538 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5539 struct ssh_channel *c;
51470298 5540 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5541 if (!c)
5542 continue; /* nonexistent channel */
5543 if (c->type != CHAN_SOCKDATA_DORMANT)
5544 continue; /* dunno why they're confirming this */
51470298 5545 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5546 c->type = CHAN_SOCKDATA;
51470298 5547 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5548 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5549 if (c->u.pfd.s)
5550 pfd_confirm(c->u.pfd.s);
5551 if (c->closes) {
5552 /*
5553 * We have a pending close on this channel,
5554 * which we decided on before the server acked
5555 * the channel open. So now we know the
5556 * remoteid, we can close it again.
5557 */
51470298 5558 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5559 ssh2_pkt_adduint32(ssh, c->remoteid);
5560 ssh2_pkt_send(ssh);
4ed34d25 5561 }
51470298 5562 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5563 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5564 struct ssh_channel *c;
51470298 5565 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5566 if (!c)
5567 continue; /* nonexistent channel */
5568 if (c->type != CHAN_SOCKDATA_DORMANT)
5569 continue; /* dunno why they're failing this */
5570
5571 logevent("Forwarded connection refused by server");
5572
5573 pfd_close(c->u.pfd.s);
5574
51470298 5575 del234(ssh->channels, c);
724cface 5576 sfree(c);
51470298 5577 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5578 unsigned localid;
5579 char *type;
5580 int typelen, want_reply;
5581 struct ssh_channel *c;
5582
51470298 5583 localid = ssh2_pkt_getuint32(ssh);
5584 ssh2_pkt_getstring(ssh, &type, &typelen);
5585 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5586
5587 /*
5588 * First, check that the channel exists. Otherwise,
5589 * we can instantly disconnect with a rude message.
5590 */
51470298 5591 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5592 if (!c) {
5593 char buf[80];
5594 sprintf(buf, "Received channel request for nonexistent"
5595 " channel %d", localid);
5596 logevent(buf);
51470298 5597 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5598 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5599 ssh2_pkt_addstring(ssh, buf);
5600 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5601 ssh2_pkt_send(ssh);
247308b5 5602 connection_fatal("%s", buf);
51470298 5603 ssh->state = SSH_STATE_CLOSED;
ebb0a590 5604 crReturnV;
5605 }
5606
5607 /*
d8d6c7e5 5608 * Having got the channel number, we now look at
5609 * the request type string to see if it's something
5610 * we recognise.
ebb0a590 5611 */
d8d6c7e5 5612 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5613 c == ssh->mainchan) {
d8d6c7e5 5614 /* We recognise "exit-status" on the primary channel. */
5615 char buf[100];
51470298 5616 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5617 sprintf(buf, "Server sent command exit status %d",
51470298 5618 ssh->exitcode);
d8d6c7e5 5619 logevent(buf);
5620 if (want_reply) {
51470298 5621 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5622 ssh2_pkt_adduint32(ssh, c->remoteid);
5623 ssh2_pkt_send(ssh);
d8d6c7e5 5624 }
5625 } else {
5626 /*
5627 * This is a channel request we don't know
5628 * about, so we now either ignore the request
5629 * or respond with CHANNEL_FAILURE, depending
5630 * on want_reply.
5631 */
5632 if (want_reply) {
51470298 5633 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5634 ssh2_pkt_adduint32(ssh, c->remoteid);
5635 ssh2_pkt_send(ssh);
d8d6c7e5 5636 }
ebb0a590 5637 }
51470298 5638 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5639 char *type;
5640 int typelen, want_reply;
5641
51470298 5642 ssh2_pkt_getstring(ssh, &type, &typelen);
5643 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5644
5645 /*
5646 * We currently don't support any global requests
5647 * at all, so we either ignore the request or
5648 * respond with REQUEST_FAILURE, depending on
5649 * want_reply.
5650 */
5651 if (want_reply) {
51470298 5652 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5653 ssh2_pkt_send(ssh);
697d4856 5654 }
51470298 5655 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5656 char *type;
5657 int typelen;
5658 char *error = NULL;
5659 struct ssh_channel *c;
bc240b21 5660 unsigned remid, winsize, pktsize;
51470298 5661 ssh2_pkt_getstring(ssh, &type, &typelen);
32874aea 5662 c = smalloc(sizeof(struct ssh_channel));
51470298 5663 c->ssh = ssh;
32874aea 5664
51470298 5665 remid = ssh2_pkt_getuint32(ssh);
5666 winsize = ssh2_pkt_getuint32(ssh);
5667 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 5668
32874aea 5669 if (typelen == 3 && !memcmp(type, "x11", 3)) {
51470298 5670 if (!ssh->X11_fwd_enabled)
32874aea 5671 error = "X11 forwarding is not enabled";
5672 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5673 NULL) {
5674 error = "Unable to open an X11 connection";
5675 } else {
5676 c->type = CHAN_X11;
5677 }
bc240b21 5678 } else if (typelen == 15 &&
5679 !memcmp(type, "forwarded-tcpip", 15)) {
5680 struct ssh_rportfwd pf, *realpf;
5681 char *dummy;
5682 int dummylen;
51470298 5683 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5684 pf.sport = ssh2_pkt_getuint32(ssh);
5685 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 5686 if (realpf == NULL) {
5687 error = "Remote port is not recognised";
5688 } else {
5689 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5690 realpf->dport, c);
5691 char buf[1024];
5692 sprintf(buf, "Received remote port open request for %s:%d",
5693 realpf->dhost, realpf->dport);
5694 logevent(buf);
5695 if (e != NULL) {
5696 sprintf(buf, "Port open failed: %s", e);
5697 logevent(buf);
5698 error = "Port open failed";
5699 } else {
5700 logevent("Forwarded port opened successfully");
5701 c->type = CHAN_SOCKDATA;
5702 }
5703 }
32874aea 5704 } else if (typelen == 22 &&
36c2a3e9 5705 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 5706 if (!ssh->agentfwd_enabled)
32874aea 5707 error = "Agent forwarding is not enabled";
36c2a3e9 5708 else {
32874aea 5709 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5710 c->u.a.lensofar = 0;
32874aea 5711 }
5712 } else {
5713 error = "Unsupported channel type requested";
5714 }
5715
bc240b21 5716 c->remoteid = remid;
32874aea 5717 if (error) {
51470298 5718 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5719 ssh2_pkt_adduint32(ssh, c->remoteid);
5720 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5721 ssh2_pkt_addstring(ssh, error);
5722 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5723 ssh2_pkt_send(ssh);
32874aea 5724 sfree(c);
5725 } else {
51470298 5726 c->localid = alloc_channel_id(ssh);
32874aea 5727 c->closes = 0;
5471d09a 5728 c->v.v2.locwindow = OUR_V2_WINSIZE;
5729 c->v.v2.remwindow = winsize;
5730 c->v.v2.remmaxpkt = pktsize;
5731 bufchain_init(&c->v.v2.outbuffer);
51470298 5732 add234(ssh->channels, c);
5733 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5734 ssh2_pkt_adduint32(ssh, c->remoteid);
5735 ssh2_pkt_adduint32(ssh, c->localid);
5736 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5737 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5738 ssh2_pkt_send(ssh);
32874aea 5739 }
7cca0d81 5740 } else {
51470298 5741 bombout(("Strange packet received: type %d", ssh->pktin.type));
32874aea 5742 crReturnV;
7cca0d81 5743 }
5744 } else {
32874aea 5745 /*
5746 * We have spare data. Add it to the channel buffer.
5747 */
51470298 5748 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5749 s->try_send = TRUE;
32874aea 5750 }
51470298 5751 if (s->try_send) {
32874aea 5752 int i;
5753 struct ssh_channel *c;
5754 /*
5755 * Try to send data on all channels if we can.
5756 */
51470298 5757 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 5758 int bufsize = ssh2_try_send(c);
5759 if (bufsize == 0) {
5760 switch (c->type) {
5761 case CHAN_MAINSESSION:
5762 /* stdin need not receive an unthrottle
5763 * notification since it will be polled */
5764 break;
5765 case CHAN_X11:
5766 x11_unthrottle(c->u.x11.s);
5767 break;
5768 case CHAN_AGENT:
5769 /* agent sockets are request/response and need no
5770 * buffer management */
5771 break;
5772 case CHAN_SOCKDATA:
5773 pfd_unthrottle(c->u.pfd.s);
5774 break;
5775 }
5776 }
5777 }
7cca0d81 5778 }
e5574168 5779 }
5780
5781 crFinishV;
5782}
5783
5784/*
7cca0d81 5785 * Handle the top-level SSH2 protocol.
5786 */
51470298 5787static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 5788{
51470298 5789 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 5790 return;
51470298 5791 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 5792}
5793
5794/*
8df7a775 5795 * Called to set up the connection.
374330e2 5796 *
5797 * Returns an error message, or NULL on success.
374330e2 5798 */
51470298 5799static char *ssh_init(void *frontend_handle, void **backend_handle,
887035a5 5800 char *host, int port, char **realhost, int nodelay)
32874aea 5801{
fb09bf1c 5802 char *p;
51470298 5803 Ssh ssh;
5804
5805 ssh = smalloc(sizeof(*ssh));
5806 ssh->s = NULL;
5807 ssh->cipher = NULL;
371e569c 5808 ssh->v1_cipher_ctx = NULL;
0183b242 5809 ssh->crcda_ctx = NULL;
51470298 5810 ssh->cscipher = NULL;
371e569c 5811 ssh->cs_cipher_ctx = NULL;
51470298 5812 ssh->sccipher = NULL;
371e569c 5813 ssh->sc_cipher_ctx = NULL;
51470298 5814 ssh->csmac = NULL;
e0e1a00d 5815 ssh->sc_mac_ctx = NULL;
51470298 5816 ssh->scmac = NULL;
e0e1a00d 5817 ssh->sc_mac_ctx = NULL;
51470298 5818 ssh->cscomp = NULL;
5819 ssh->sccomp = NULL;
5820 ssh->kex = NULL;
5821 ssh->hostkey = NULL;
5822 ssh->exitcode = -1;
5823 ssh->state = SSH_STATE_PREPACKET;
5824 ssh->size_needed = FALSE;
5825 ssh->eof_needed = FALSE;
5826 {
5827 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5828 ssh->pktin = ssh->pktout = empty;
5829 }
5830 ssh->deferred_send_data = NULL;
5831 ssh->deferred_len = 0;
5832 ssh->deferred_size = 0;
5833 ssh->fallback_cmd = 0;
5834 ssh->pkt_ctx = 0;
5835 ssh->v2_outgoing_sequence = 0;
5836 ssh->ssh1_rdpkt_crstate = 0;
5837 ssh->ssh2_rdpkt_crstate = 0;
5838 ssh->do_ssh_init_crstate = 0;
5839 ssh->ssh_gotdata_crstate = 0;
5840 ssh->ssh1_protocol_crstate = 0;
5841 ssh->do_ssh1_login_crstate = 0;
5842 ssh->do_ssh2_transport_crstate = 0;
5843 ssh->do_ssh2_authconn_crstate = 0;
5844 ssh->do_ssh_init_state = NULL;
5845 ssh->do_ssh1_login_state = NULL;
5846 ssh->do_ssh2_transport_state = NULL;
5847 ssh->do_ssh2_authconn_state = NULL;
5848
5849 *backend_handle = ssh;
32874aea 5850
8f203108 5851#ifdef MSCRYPTOAPI
32874aea 5852 if (crypto_startup() == 0)
8f203108 5853 return "Microsoft high encryption pack not installed!";
5854#endif
374330e2 5855
51470298 5856 ssh->frontend = frontend_handle;
5857 ssh->term_width = cfg.width;
5858 ssh->term_height = cfg.height;
887035a5 5859
51470298 5860 ssh->send_ok = 0;
5861 ssh->editing = 0;
5862 ssh->echoing = 0;
5863 ssh->v1_throttle_count = 0;
5864 ssh->overall_bufsize = 0;
5865 ssh->fallback_cmd = 0;
8df7a775 5866
51470298 5867 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 5868 if (p != NULL)
5869 return p;
374330e2 5870
374330e2 5871 return NULL;
5872}
5873
5874/*
374330e2 5875 * Called to send data down the Telnet connection.
5876 */
51470298 5877static int ssh_send(void *handle, char *buf, int len)
32874aea 5878{
51470298 5879 Ssh ssh = (Ssh) handle;
5880
5881 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5882 return 0;
374330e2 5883
51470298 5884 ssh->protocol(ssh, buf, len, 0);
5471d09a 5885
51470298 5886 return ssh_sendbuffer(ssh);
5471d09a 5887}
5888
5889/*
5890 * Called to query the current amount of buffered stdin data.
5891 */
51470298 5892static int ssh_sendbuffer(void *handle)
5471d09a 5893{
51470298 5894 Ssh ssh = (Ssh) handle;
5471d09a 5895 int override_value;
5896
51470298 5897 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 5898 return 0;
5899
5900 /*
5901 * If the SSH socket itself has backed up, add the total backup
5902 * size on that to any individual buffer on the stdin channel.
5903 */
5904 override_value = 0;
51470298 5905 if (ssh->throttled_all)
5906 override_value = ssh->overall_bufsize;
5471d09a 5907
51470298 5908 if (ssh->version == 1) {
5471d09a 5909 return override_value;
51470298 5910 } else if (ssh->version == 2) {
5911 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 5912 return override_value;
5913 else
51470298 5914 return (override_value +
5915 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 5916 }
5917
5918 return 0;
374330e2 5919}
5920
5921/*
6e48c3fe 5922 * Called to set the size of the window from SSH's POV.
374330e2 5923 */
51470298 5924static void ssh_size(void *handle, int width, int height)
32874aea 5925{
51470298 5926 Ssh ssh = (Ssh) handle;
5927
5928 ssh->term_width = width;
5929 ssh->term_height = height;
f278d6f8 5930
51470298 5931 switch (ssh->state) {
374330e2 5932 case SSH_STATE_BEFORE_SIZE:
3687d221 5933 case SSH_STATE_PREPACKET:
21248260 5934 case SSH_STATE_CLOSED:
374330e2 5935 break; /* do nothing */
5936 case SSH_STATE_INTERMED:
51470298 5937 ssh->size_needed = TRUE; /* buffer for later */
374330e2 5938 break;
5939 case SSH_STATE_SESSION:
32874aea 5940 if (!cfg.nopty) {
887035a5 5941 if (!term)
5942 return;
51470298 5943 if (ssh->version == 1) {
5944 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
5945 PKT_INT, ssh->term_height,
5946 PKT_INT, ssh->term_width,
32874aea 5947 PKT_INT, 0, PKT_INT, 0, PKT_END);
5948 } else {
51470298 5949 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5950 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5951 ssh2_pkt_addstring(ssh, "window-change");
5952 ssh2_pkt_addbool(ssh, 0);
5953 ssh2_pkt_adduint32(ssh, ssh->term_width);
5954 ssh2_pkt_adduint32(ssh, ssh->term_height);
5955 ssh2_pkt_adduint32(ssh, 0);
5956 ssh2_pkt_adduint32(ssh, 0);
5957 ssh2_pkt_send(ssh);
32874aea 5958 }
5959 }
5960 break;
374330e2 5961 }
5962}
5963
5964/*
6abbf9e3 5965 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5966 * can send an EOF and collect resulting output (e.g. `plink
5967 * hostname sort').
374330e2 5968 */
51470298 5969static void ssh_special(void *handle, Telnet_Special code)
32874aea 5970{
51470298 5971 Ssh ssh = (Ssh) handle;
5972
6abbf9e3 5973 if (code == TS_EOF) {
51470298 5974 if (ssh->state != SSH_STATE_SESSION) {
32874aea 5975 /*
5976 * Buffer the EOF in case we are pre-SESSION, so we can
5977 * send it as soon as we reach SESSION.
5978 */
5979 if (code == TS_EOF)
51470298 5980 ssh->eof_needed = TRUE;
32874aea 5981 return;
5982 }
51470298 5983 if (ssh->version == 1) {
5984 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 5985 } else {
51470298 5986 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
5987 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5988 ssh2_pkt_send(ssh);
32874aea 5989 }
5990 logevent("Sent EOF message");
ec55b220 5991 } else if (code == TS_PING) {
51470298 5992 if (ssh->state == SSH_STATE_CLOSED
5993 || ssh->state == SSH_STATE_PREPACKET) return;
5994 if (ssh->version == 1) {
5995 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
5996 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 5997 } else {
51470298 5998 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5999 ssh2_pkt_addstring_start(ssh);
6000 ssh2_pkt_send(ssh);
32874aea 6001 }
6abbf9e3 6002 } else {
32874aea 6003 /* do nothing */
6abbf9e3 6004 }
374330e2 6005}
6006
51470298 6007void *new_sock_channel(void *handle, Socket s)
d74d141c 6008{
51470298 6009 Ssh ssh = (Ssh) handle;
d74d141c 6010 struct ssh_channel *c;
6011 c = smalloc(sizeof(struct ssh_channel));
51470298 6012 c->ssh = ssh;
d74d141c 6013
6014 if (c) {
bc240b21 6015 c->remoteid = -1; /* to be set when open confirmed */
51470298 6016 c->localid = alloc_channel_id(ssh);
d74d141c 6017 c->closes = 0;
bc240b21 6018 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6019 c->u.pfd.s = s;
013dd8c0 6020 bufchain_init(&c->v.v2.outbuffer);
51470298 6021 add234(ssh->channels, c);
d74d141c 6022 }
6023 return c;
6024}
6025
5471d09a 6026/*
6027 * This is called when stdout/stderr (the entity to which
6028 * from_backend sends data) manages to clear some backlog.
6029 */
51470298 6030void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6031{
51470298 6032 Ssh ssh = (Ssh) handle;
6033 if (ssh->version == 1) {
6034 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6035 ssh->v1_stdout_throttling = 0;
6036 ssh1_throttle(ssh, -1);
5471d09a 6037 }
6038 } else {
51470298 6039 if (ssh->mainchan && ssh->mainchan->closes == 0)
6040 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6041 }
6042}
6043
51470298 6044void ssh_send_port_open(void *handle, void *channel, char *hostname,
6045 int port, char *org)
d74d141c 6046{
51470298 6047 Ssh ssh = (Ssh) handle;
d74d141c 6048 struct ssh_channel *c = (struct ssh_channel *)channel;
6049 char buf[1024];
6050
6051 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
6052 logevent(buf);
6053
51470298 6054 if (ssh->version == 1) {
6055 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6056 PKT_INT, c->localid,
6057 PKT_STR, hostname,
6058 PKT_INT, port,
6059 //PKT_STR, <org:orgport>,
6060 PKT_END);
6061 } else {
51470298 6062 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6063 ssh2_pkt_addstring(ssh, "direct-tcpip");
6064 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6065 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6066 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6067 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6068 ssh2_pkt_addstring(ssh, hostname);
6069 ssh2_pkt_adduint32(ssh, port);
bc240b21 6070 /*
6071 * We make up values for the originator data; partly it's
6072 * too much hassle to keep track, and partly I'm not
6073 * convinced the server should be told details like that
6074 * about my local network configuration.
6075 */
51470298 6076 ssh2_pkt_addstring(ssh, "client-side-connection");
6077 ssh2_pkt_adduint32(ssh, 0);
6078 ssh2_pkt_send(ssh);
bc240b21 6079 }
d74d141c 6080}
6081
6082
51470298 6083static Socket ssh_socket(void *handle)
32874aea 6084{
51470298 6085 Ssh ssh = (Ssh) handle;
6086 return ssh->s;
32874aea 6087}
8ccc75b0 6088
51470298 6089static int ssh_sendok(void *handle)
32874aea 6090{
51470298 6091 Ssh ssh = (Ssh) handle;
6092 return ssh->send_ok;
32874aea 6093}
fb09bf1c 6094
51470298 6095static int ssh_ldisc(void *handle, int option)
32874aea 6096{
51470298 6097 Ssh ssh = (Ssh) handle;
32874aea 6098 if (option == LD_ECHO)
51470298 6099 return ssh->echoing;
32874aea 6100 if (option == LD_EDIT)
51470298 6101 return ssh->editing;
0965bee0 6102 return FALSE;
6103}
6104
51470298 6105static int ssh_return_exitcode(void *handle)
6106{
6107 Ssh ssh = (Ssh) handle;
6108 return ssh->exitcode;
6109}
6110
6111/*
6112 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6113 * that fails. This variable is the means by which scp.c can reach
6114 * into the SSH code and find out which one it got.
6115 */
6116extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6117{
51470298 6118 Ssh ssh = (Ssh) handle;
6119 return ssh->fallback_cmd;
d8d6c7e5 6120}
6121
374330e2 6122Backend ssh_backend = {
6123 ssh_init,
374330e2 6124 ssh_send,
5471d09a 6125 ssh_sendbuffer,
374330e2 6126 ssh_size,
4017be6d 6127 ssh_special,
8ccc75b0 6128 ssh_socket,
d8d6c7e5 6129 ssh_return_exitcode,
97db3be4 6130 ssh_sendok,
0965bee0 6131 ssh_ldisc,
5471d09a 6132 ssh_unthrottle,
97db3be4 6133 22
bc240b21 6134};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator