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Use a single sftp_senddata() to send each SFTP packet, rather than
[u/mdw/putty] / ssh.c
CommitLineData
eaf1e20a 1/*
2 * SSH backend.
3 */
4
374330e2 5#include <stdio.h>
6#include <stdlib.h>
fb09bf1c 7#include <stdarg.h>
8#include <assert.h>
3c112d53 9#include <limits.h>
d051d1b4 10#include <signal.h>
374330e2 11
12#include "putty.h"
dacbd0e8 13#include "tree234.h"
fb09bf1c 14#include "ssh.h"
bf84a03a 15#ifndef NO_GSSAPI
b3d375b2 16#include "sshgssc.h"
42af6a67 17#include "sshgss.h"
bf84a03a 18#endif
374330e2 19
20#ifndef FALSE
21#define FALSE 0
22#endif
23#ifndef TRUE
24#define TRUE 1
25#endif
26
32874aea 27#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
28#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
29#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
30#define SSH1_CMSG_USER 4 /* 0x4 */
31#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
32#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
33#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
34#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
35#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
36#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
37#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
38#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
39#define SSH1_SMSG_SUCCESS 14 /* 0xe */
40#define SSH1_SMSG_FAILURE 15 /* 0xf */
41#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
42#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
43#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
44#define SSH1_CMSG_EOF 19 /* 0x13 */
45#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
46#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
47#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
48#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
49#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
50#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
51#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
52#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
53#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
54#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
55#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
56#define SSH1_MSG_IGNORE 32 /* 0x20 */
57#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
59#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
60#define SSH1_MSG_DEBUG 36 /* 0x24 */
61#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
62#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
63#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
64#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
65#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
66#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
67#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68
8f9e3231 69#define SSH1_AUTH_RHOSTS 1 /* 0x1 */
70#define SSH1_AUTH_RSA 2 /* 0x2 */
71#define SSH1_AUTH_PASSWORD 3 /* 0x3 */
72#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
32874aea 73#define SSH1_AUTH_TIS 5 /* 0x5 */
74#define SSH1_AUTH_CCARD 16 /* 0x10 */
75
76#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 77/* Mask for protoflags we will echo back to server if seen */
32874aea 78#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
79
80#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81#define SSH2_MSG_IGNORE 2 /* 0x2 */
82#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83#define SSH2_MSG_DEBUG 4 /* 0x4 */
84#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86#define SSH2_MSG_KEXINIT 20 /* 0x14 */
87#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
fae1a71b 94#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
95#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
96#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
32874aea 97#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
98#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
99#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
100#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
101#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
102#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 103#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
104#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 105#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
106#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
107#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
108#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
109#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
110#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
111#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
112#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
113#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
114#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
115#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
116#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
117#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
118#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
42af6a67 119#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
120#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
121#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
122#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
123#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
124#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
32874aea 125
00db133f 126/*
127 * Packet type contexts, so that ssh2_pkt_type can correctly decode
128 * the ambiguous type numbers back into the correct type strings.
129 */
acab36bc 130typedef enum {
131 SSH2_PKTCTX_NOKEX,
132 SSH2_PKTCTX_DHGROUP,
133 SSH2_PKTCTX_DHGEX,
134 SSH2_PKTCTX_RSAKEX
135} Pkt_KCtx;
136typedef enum {
137 SSH2_PKTCTX_NOAUTH,
138 SSH2_PKTCTX_PUBLICKEY,
139 SSH2_PKTCTX_PASSWORD,
42af6a67 140 SSH2_PKTCTX_GSSAPI,
acab36bc 141 SSH2_PKTCTX_KBDINTER
142} Pkt_ACtx;
00db133f 143
32874aea 144#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
145#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
146#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
147#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
148#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
149#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
150#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
151#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
152#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
153#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
154#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
155#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
156#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
157#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
158#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 159
160static const char *const ssh2_disconnect_reasons[] = {
161 NULL,
afb4d0dc 162 "host not allowed to connect",
163 "protocol error",
164 "key exchange failed",
165 "host authentication failed",
1da38d29 166 "MAC error",
afb4d0dc 167 "compression error",
168 "service not available",
169 "protocol version not supported",
170 "host key not verifiable",
171 "connection lost",
172 "by application",
173 "too many connections",
174 "auth cancelled by user",
175 "no more auth methods available",
176 "illegal user name",
38c4a8da 177};
9005f3ba 178
32874aea 179#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
180#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
181#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
182#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 183
32874aea 184#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 185
7d503c31 186/*
187 * Various remote-bug flags.
188 */
189#define BUG_CHOKES_ON_SSH1_IGNORE 1
190#define BUG_SSH2_HMAC 2
bd358db1 191#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 192#define BUG_CHOKES_ON_RSA 8
1dd353b5 193#define BUG_SSH2_RSA_PADDING 16
088bde77 194#define BUG_SSH2_DERIVEKEY 32
f382c87d 195#define BUG_SSH2_REKEY 64
dda87a28 196#define BUG_SSH2_PK_SESSIONID 128
c9739dba 197#define BUG_SSH2_MAXPKT 256
cf6ddb95 198#define BUG_CHOKES_ON_SSH2_IGNORE 512
2e0aae4f 199#define BUG_CHOKES_ON_WINADJ 1024
bd358db1 200
c6ccd5c2 201/*
202 * Codes for terminal modes.
203 * Most of these are the same in SSH-1 and SSH-2.
7646c432 204 * This list is derived from RFC 4254 and
c6ccd5c2 205 * SSH-1 RFC-1.2.31.
206 */
207static const struct {
208 const char* const mode;
209 int opcode;
210 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
211} ssh_ttymodes[] = {
212 /* "V" prefix discarded for special characters relative to SSH specs */
213 { "INTR", 1, TTY_OP_CHAR },
214 { "QUIT", 2, TTY_OP_CHAR },
215 { "ERASE", 3, TTY_OP_CHAR },
216 { "KILL", 4, TTY_OP_CHAR },
217 { "EOF", 5, TTY_OP_CHAR },
218 { "EOL", 6, TTY_OP_CHAR },
219 { "EOL2", 7, TTY_OP_CHAR },
220 { "START", 8, TTY_OP_CHAR },
221 { "STOP", 9, TTY_OP_CHAR },
222 { "SUSP", 10, TTY_OP_CHAR },
223 { "DSUSP", 11, TTY_OP_CHAR },
224 { "REPRINT", 12, TTY_OP_CHAR },
225 { "WERASE", 13, TTY_OP_CHAR },
226 { "LNEXT", 14, TTY_OP_CHAR },
227 { "FLUSH", 15, TTY_OP_CHAR },
228 { "SWTCH", 16, TTY_OP_CHAR },
229 { "STATUS", 17, TTY_OP_CHAR },
230 { "DISCARD", 18, TTY_OP_CHAR },
231 { "IGNPAR", 30, TTY_OP_BOOL },
232 { "PARMRK", 31, TTY_OP_BOOL },
233 { "INPCK", 32, TTY_OP_BOOL },
234 { "ISTRIP", 33, TTY_OP_BOOL },
235 { "INLCR", 34, TTY_OP_BOOL },
236 { "IGNCR", 35, TTY_OP_BOOL },
237 { "ICRNL", 36, TTY_OP_BOOL },
238 { "IUCLC", 37, TTY_OP_BOOL },
239 { "IXON", 38, TTY_OP_BOOL },
240 { "IXANY", 39, TTY_OP_BOOL },
241 { "IXOFF", 40, TTY_OP_BOOL },
242 { "IMAXBEL", 41, TTY_OP_BOOL },
243 { "ISIG", 50, TTY_OP_BOOL },
244 { "ICANON", 51, TTY_OP_BOOL },
245 { "XCASE", 52, TTY_OP_BOOL },
246 { "ECHO", 53, TTY_OP_BOOL },
247 { "ECHOE", 54, TTY_OP_BOOL },
248 { "ECHOK", 55, TTY_OP_BOOL },
249 { "ECHONL", 56, TTY_OP_BOOL },
250 { "NOFLSH", 57, TTY_OP_BOOL },
251 { "TOSTOP", 58, TTY_OP_BOOL },
252 { "IEXTEN", 59, TTY_OP_BOOL },
253 { "ECHOCTL", 60, TTY_OP_BOOL },
254 { "ECHOKE", 61, TTY_OP_BOOL },
255 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
256 { "OPOST", 70, TTY_OP_BOOL },
257 { "OLCUC", 71, TTY_OP_BOOL },
258 { "ONLCR", 72, TTY_OP_BOOL },
259 { "OCRNL", 73, TTY_OP_BOOL },
260 { "ONOCR", 74, TTY_OP_BOOL },
261 { "ONLRET", 75, TTY_OP_BOOL },
262 { "CS7", 90, TTY_OP_BOOL },
263 { "CS8", 91, TTY_OP_BOOL },
264 { "PARENB", 92, TTY_OP_BOOL },
265 { "PARODD", 93, TTY_OP_BOOL }
266};
267
268/* Miscellaneous other tty-related constants. */
269#define SSH_TTY_OP_END 0
270/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
271#define SSH1_TTY_OP_ISPEED 192
272#define SSH1_TTY_OP_OSPEED 193
273#define SSH2_TTY_OP_ISPEED 128
274#define SSH2_TTY_OP_OSPEED 129
275
276/* Helper functions for parsing tty-related config. */
277static unsigned int ssh_tty_parse_specchar(char *s)
278{
279 unsigned int ret;
280 if (*s) {
281 char *next = NULL;
282 ret = ctrlparse(s, &next);
283 if (!next) ret = s[0];
284 } else {
285 ret = 255; /* special value meaning "don't set" */
286 }
287 return ret;
288}
289static unsigned int ssh_tty_parse_boolean(char *s)
290{
291 if (stricmp(s, "yes") == 0 ||
292 stricmp(s, "on") == 0 ||
293 stricmp(s, "true") == 0 ||
294 stricmp(s, "+") == 0)
295 return 1; /* true */
296 else if (stricmp(s, "no") == 0 ||
297 stricmp(s, "off") == 0 ||
298 stricmp(s, "false") == 0 ||
299 stricmp(s, "-") == 0)
300 return 0; /* false */
301 else
302 return (atoi(s) != 0);
303}
304
00db133f 305#define translate(x) if (type == x) return #x
acab36bc 306#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
307#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
ae9ae89f 308static char *ssh1_pkt_type(int type)
00db133f 309{
310 translate(SSH1_MSG_DISCONNECT);
311 translate(SSH1_SMSG_PUBLIC_KEY);
312 translate(SSH1_CMSG_SESSION_KEY);
313 translate(SSH1_CMSG_USER);
314 translate(SSH1_CMSG_AUTH_RSA);
315 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
316 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
317 translate(SSH1_CMSG_AUTH_PASSWORD);
318 translate(SSH1_CMSG_REQUEST_PTY);
319 translate(SSH1_CMSG_WINDOW_SIZE);
320 translate(SSH1_CMSG_EXEC_SHELL);
321 translate(SSH1_CMSG_EXEC_CMD);
322 translate(SSH1_SMSG_SUCCESS);
323 translate(SSH1_SMSG_FAILURE);
324 translate(SSH1_CMSG_STDIN_DATA);
325 translate(SSH1_SMSG_STDOUT_DATA);
326 translate(SSH1_SMSG_STDERR_DATA);
327 translate(SSH1_CMSG_EOF);
328 translate(SSH1_SMSG_EXIT_STATUS);
329 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
330 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
331 translate(SSH1_MSG_CHANNEL_DATA);
332 translate(SSH1_MSG_CHANNEL_CLOSE);
333 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
334 translate(SSH1_SMSG_X11_OPEN);
335 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
336 translate(SSH1_MSG_PORT_OPEN);
337 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
338 translate(SSH1_SMSG_AGENT_OPEN);
339 translate(SSH1_MSG_IGNORE);
340 translate(SSH1_CMSG_EXIT_CONFIRMATION);
341 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
342 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
343 translate(SSH1_MSG_DEBUG);
344 translate(SSH1_CMSG_REQUEST_COMPRESSION);
345 translate(SSH1_CMSG_AUTH_TIS);
346 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
347 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
348 translate(SSH1_CMSG_AUTH_CCARD);
349 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
350 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
351 return "unknown";
352}
acab36bc 353static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
00db133f 354{
42af6a67 355 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
360 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
00db133f 361 translate(SSH2_MSG_DISCONNECT);
362 translate(SSH2_MSG_IGNORE);
363 translate(SSH2_MSG_UNIMPLEMENTED);
364 translate(SSH2_MSG_DEBUG);
365 translate(SSH2_MSG_SERVICE_REQUEST);
366 translate(SSH2_MSG_SERVICE_ACCEPT);
367 translate(SSH2_MSG_KEXINIT);
368 translate(SSH2_MSG_NEWKEYS);
acab36bc 369 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
371 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
375 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
377 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
00db133f 378 translate(SSH2_MSG_USERAUTH_REQUEST);
379 translate(SSH2_MSG_USERAUTH_FAILURE);
380 translate(SSH2_MSG_USERAUTH_SUCCESS);
381 translate(SSH2_MSG_USERAUTH_BANNER);
acab36bc 382 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
383 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
384 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
385 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
00db133f 386 translate(SSH2_MSG_GLOBAL_REQUEST);
387 translate(SSH2_MSG_REQUEST_SUCCESS);
388 translate(SSH2_MSG_REQUEST_FAILURE);
389 translate(SSH2_MSG_CHANNEL_OPEN);
390 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
391 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
392 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
393 translate(SSH2_MSG_CHANNEL_DATA);
394 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
395 translate(SSH2_MSG_CHANNEL_EOF);
396 translate(SSH2_MSG_CHANNEL_CLOSE);
397 translate(SSH2_MSG_CHANNEL_REQUEST);
398 translate(SSH2_MSG_CHANNEL_SUCCESS);
399 translate(SSH2_MSG_CHANNEL_FAILURE);
400 return "unknown";
401}
402#undef translate
403#undef translatec
7d503c31 404
9a10ecf4 405/* Enumeration values for fields in SSH-1 packets */
406enum {
407 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
408 /* These values are for communicating relevant semantics of
409 * fields to the packet logging code. */
410 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
411};
972a41c8 412
acddebd9 413/*
414 * Coroutine mechanics for the sillier bits of the code. If these
415 * macros look impenetrable to you, you might find it helpful to
416 * read
417 *
418 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
419 *
420 * which explains the theory behind these macros.
b624d1e6 421 *
422 * In particular, if you are getting `case expression not constant'
423 * errors when building with MS Visual Studio, this is because MS's
424 * Edit and Continue debugging feature causes their compiler to
425 * violate ANSI C. To disable Edit and Continue debugging:
426 *
427 * - right-click ssh.c in the FileView
428 * - click Settings
429 * - select the C/C++ tab and the General category
430 * - under `Debug info:', select anything _other_ than `Program
431 * Database for Edit and Continue'.
acddebd9 432 */
51470298 433#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
434#define crState(t) \
435 struct t *s; \
3d88e64d 436 if (!ssh->t) ssh->t = snew(struct t); \
51470298 437 s = ssh->t;
438#define crFinish(z) } *crLine = 0; return (z); }
439#define crFinishV } *crLine = 0; return; }
374330e2 440#define crReturn(z) \
441 do {\
51470298 442 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 443 } while (0)
444#define crReturnV \
445 do {\
51470298 446 *crLine=__LINE__; return; case __LINE__:;\
374330e2 447 } while (0)
51470298 448#define crStop(z) do{ *crLine = 0; return (z); }while(0)
449#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 450#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 451#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 452
51470298 453typedef struct ssh_tag *Ssh;
ff3187f6 454struct Packet;
455
dacd8872 456static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 457static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 458static void ssh_pkt_ensure(struct Packet *, int length);
459static void ssh_pkt_adddata(struct Packet *, void *data, int len);
460static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 461static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 462static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
463static void ssh_pkt_addstring_start(struct Packet *);
464static void ssh_pkt_addstring_str(struct Packet *, char *data);
465static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
466static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 467static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 468static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 469static void ssh2_pkt_addmp(struct Packet *, Bignum b);
470static int ssh2_pkt_construct(Ssh, struct Packet *);
471static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 472static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 473static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
474 struct Packet *pktin);
475static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
476 struct Packet *pktin);
997097db 477static void ssh2_channel_check_close(struct ssh_channel *c);
bc06669b 478static void ssh_channel_destroy(struct ssh_channel *c);
3d63ca2e 479
5471d09a 480/*
481 * Buffer management constants. There are several of these for
482 * various different purposes:
483 *
484 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
485 * on a local data stream before we throttle the whole SSH
2e85c969 486 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 487 * pretty drastic so we set this high in the hope it won't
488 * happen very often.
489 *
490 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
491 * on the SSH connection itself before we defensively throttle
492 * _all_ local data streams. This is pretty drastic too (though
2e85c969 493 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 494 * ensure that the server never has any need to throttle its end
495 * of the connection), so we set this high as well.
496 *
2e85c969 497 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 498 * channels.
9b53e9b8 499 *
500 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 501 * channel in a simple connection. It must be <= INT_MAX.
9916cc1e 502 *
503 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
504 * to the remote side. This actually has nothing to do with the
505 * size of the _packet_, but is instead a limit on the amount
506 * of data we're willing to receive in a single SSH2 channel
507 * data message.
508 *
509 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
510 * _packet_ we're prepared to cope with. It must be a multiple
511 * of the cipher block size, and must be at least 35000.
5471d09a 512 */
513
514#define SSH1_BUFFER_LIMIT 32768
515#define SSH_MAX_BACKLOG 32768
516#define OUR_V2_WINSIZE 16384
3361b80a 517#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 518#define OUR_V2_MAXPKT 0x4000UL
9916cc1e 519#define OUR_V2_PACKETLIMIT 0x9000UL
d74d141c 520
85cc02bb 521const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 522
8b2715b2 523const static struct ssh_mac *macs[] = {
6668a75e 524 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 525};
8b2715b2 526const static struct ssh_mac *buggymacs[] = {
6668a75e 527 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 528};
e5574168 529
5366aed8 530static void *ssh_comp_none_init(void)
531{
532 return NULL;
533}
534static void ssh_comp_none_cleanup(void *handle)
32874aea 535{
536}
5366aed8 537static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 538 unsigned char **outblock, int *outlen)
539{
540 return 0;
541}
5366aed8 542static int ssh_comp_none_disable(void *handle)
32874aea 543{
4ba9b64b 544 return 0;
545}
57476f6b 546const static struct ssh_compress ssh_comp_none = {
ab18ccff 547 "none", NULL,
5366aed8 548 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
549 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
550 ssh_comp_none_disable, NULL
e5574168 551};
4ba9b64b 552extern const struct ssh_compress ssh_zlib;
553const static struct ssh_compress *compressions[] = {
32874aea 554 &ssh_zlib, &ssh_comp_none
555};
374330e2 556
32874aea 557enum { /* channel types */
783415f8 558 CHAN_MAINSESSION,
559 CHAN_X11,
560 CHAN_AGENT,
bc240b21 561 CHAN_SOCKDATA,
c6b41791 562 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
563 /*
564 * CHAN_ZOMBIE is used to indicate a channel for which we've
565 * already destroyed the local data source: for instance, if a
566 * forwarded port experiences a socket error on the local side, we
567 * immediately destroy its local socket and turn the SSH channel
568 * into CHAN_ZOMBIE.
569 */
570 CHAN_ZOMBIE
783415f8 571};
572
dacbd0e8 573/*
0e443c99 574 * little structure to keep track of outstanding WINDOW_ADJUSTs
575 */
576struct winadj {
577 struct winadj *next;
578 unsigned size;
579};
580
581/*
dacbd0e8 582 * 2-3-4 tree storing channels.
583 */
584struct ssh_channel {
51470298 585 Ssh ssh; /* pointer back to main context */
d211621f 586 unsigned remoteid, localid;
dacbd0e8 587 int type;
64d6ff88 588 /* True if we opened this channel but server hasn't confirmed. */
589 int halfopen;
0357890f 590 /*
2e85c969 591 * In SSH-1, this value contains four bits:
0357890f 592 *
593 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
594 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
595 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
596 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
597 *
598 * A channel is completely finished with when all four bits are set.
bc06669b 599 *
600 * In SSH-2, the four bits mean:
601 *
602 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
603 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
604 * 4 We have received SSH2_MSG_CHANNEL_EOF.
605 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
606 *
607 * A channel is completely finished with when we have both sent
608 * and received CLOSE.
609 *
610 * The symbolic constants below use the SSH-2 terminology, which
611 * is a bit confusing in SSH-1, but we have to use _something_.
0357890f 612 */
bc06669b 613#define CLOSES_SENT_EOF 1
614#define CLOSES_SENT_CLOSE 2
615#define CLOSES_RCVD_EOF 4
616#define CLOSES_RCVD_CLOSE 8
dacbd0e8 617 int closes;
78280721 618
619 /*
bc06669b 620 * This flag indicates that an EOF is pending on the outgoing side
621 * of the channel: that is, wherever we're getting the data for
622 * this channel has sent us some data followed by EOF. We can't
623 * actually send the EOF until we've finished sending the data, so
624 * we set this flag instead to remind us to do so once our buffer
625 * is clear.
78280721 626 */
bc06669b 627 int pending_eof;
78280721 628
ff68564b 629 /*
630 * True if this channel is causing the underlying connection to be
631 * throttled.
632 */
633 int throttling_conn;
5471d09a 634 union {
5471d09a 635 struct ssh2_data_channel {
636 bufchain outbuffer;
637 unsigned remwindow, remmaxpkt;
467e064d 638 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 639 int locwindow, locmaxwin;
0e443c99 640 /*
641 * remlocwin is the amount of local window that we think
642 * the remote end had available to it after it sent the
643 * last data packet or window adjust ack.
644 */
645 int remlocwin;
646 /*
647 * These store the list of window adjusts that haven't
648 * been acked.
649 */
650 struct winadj *winadj_head, *winadj_tail;
651 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 652 } v2;
653 } v;
dacbd0e8 654 union {
32874aea 655 struct ssh_agent_channel {
656 unsigned char *message;
657 unsigned char msglen[4];
a03c9f9c 658 unsigned lensofar, totallen;
32874aea 659 } a;
660 struct ssh_x11_channel {
661 Socket s;
662 } x11;
d74d141c 663 struct ssh_pfd_channel {
664 Socket s;
665 } pfd;
dacbd0e8 666 } u;
667};
57476f6b 668
d74d141c 669/*
2e85c969 670 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
671 * use this structure in different ways, reflecting SSH-2's
bc240b21 672 * altogether saner approach to port forwarding.
673 *
2e85c969 674 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 675 * the remote port number, and the local destination host:port.
676 * When a connection comes in, the server sends you back that
677 * host:port pair, and you connect to it. This is a ready-made
678 * security hole if you're not on the ball: a malicious server
679 * could send you back _any_ host:port pair, so if you trustingly
680 * connect to the address it gives you then you've just opened the
681 * entire inside of your corporate network just by connecting
682 * through it to a dodgy SSH server. Hence, we must store a list of
683 * host:port pairs we _are_ trying to forward to, and reject a
684 * connection request from the server if it's not in the list.
685 *
2e85c969 686 * In SSH-2, each side of the connection minds its own business and
bc240b21 687 * doesn't send unnecessary information to the other. You arrange a
688 * remote forwarding by sending the server just the remote port
689 * number. When a connection comes in, the server tells you which
690 * of its ports was connected to; and _you_ have to remember what
691 * local host:port pair went with that port number.
692 *
2e85c969 693 * Hence, in SSH-1 this structure is indexed by destination
694 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 695 */
fda2feb1 696struct ssh_portfwd; /* forward declaration */
697
d74d141c 698struct ssh_rportfwd {
bc240b21 699 unsigned sport, dport;
700 char dhost[256];
06fadff5 701 char *sportdesc;
fda2feb1 702 struct ssh_portfwd *pfrec;
d74d141c 703};
fda2feb1 704#define free_rportfwd(pf) ( \
705 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
706
707/*
708 * Separately to the rportfwd tree (which is for looking up port
709 * open requests from the server), a tree of _these_ structures is
710 * used to keep track of all the currently open port forwardings,
711 * so that we can reconfigure in mid-session if the user requests
712 * it.
713 */
714struct ssh_portfwd {
84328ddb 715 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 716 int type;
717 unsigned sport, dport;
718 char *saddr, *daddr;
3fe92132 719 char *sserv, *dserv;
fda2feb1 720 struct ssh_rportfwd *remote;
05581745 721 int addressfamily;
fda2feb1 722 void *local;
723};
724#define free_portfwd(pf) ( \
3fe92132 725 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
726 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 727
57476f6b 728struct Packet {
dacd8872 729 long length; /* length of `data' actually used */
730 long forcepad; /* SSH-2: force padding to at least this length */
731 int type; /* only used for incoming packets */
732 unsigned long sequence; /* SSH-2 incoming sequence number */
733 unsigned char *data; /* allocated storage */
734 unsigned char *body; /* offset of payload within `data' */
735 long savedpos; /* temporary index into `data' (for strings) */
736 long maxlen; /* amount of storage allocated for `data' */
737 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 738
739 /*
740 * State associated with packet logging
741 */
742 int logmode;
743 int nblanks;
744 struct logblank_t *blanks;
57476f6b 745};
746
1c1a7262 747static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 748 struct Packet *pktin);
1c1a7262 749static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 750 struct Packet *pktin);
b09eaa88 751static void ssh1_protocol_setup(Ssh ssh);
752static void ssh2_protocol_setup(Ssh ssh);
51470298 753static void ssh_size(void *handle, int width, int height);
754static void ssh_special(void *handle, Telnet_Special);
5471d09a 755static int ssh2_try_send(struct ssh_channel *c);
51470298 756static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
757static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 758static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 759static int ssh_sendbuffer(void *handle);
ac934965 760static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 761static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
762static int ssh2_pkt_getbool(struct Packet *pkt);
763static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 764static void ssh2_timer(void *ctx, long now);
1c1a7262 765static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 766 struct Packet *pktin);
57476f6b 767
51470298 768struct rdpkt1_state_tag {
57476f6b 769 long len, pad, biglen, to_read;
770 unsigned long realcrc, gotcrc;
771 unsigned char *p;
772 int i;
773 int chunk;
ff3187f6 774 struct Packet *pktin;
51470298 775};
57476f6b 776
51470298 777struct rdpkt2_state_tag {
960e736a 778 long len, pad, payload, packetlen, maclen;
779 int i;
780 int cipherblk;
781 unsigned long incoming_sequence;
ff3187f6 782 struct Packet *pktin;
51470298 783};
784
b09eaa88 785typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 786typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
787
788struct queued_handler;
789struct queued_handler {
790 int msg1, msg2;
791 chandler_fn_t handler;
792 void *ctx;
793 struct queued_handler *next;
794};
b09eaa88 795
51470298 796struct ssh_tag {
797 const struct plug_function_table *fn;
798 /* the above field _must_ be first in the structure */
799
4320baf7 800 char *v_c, *v_s;
b672f405 801 void *exhash;
51470298 802
803 Socket s;
804
b9d7bcad 805 void *ldisc;
a8327734 806 void *logctx;
b9d7bcad 807
51470298 808 unsigned char session_key[32];
809 int v1_compressing;
810 int v1_remote_protoflags;
811 int v1_local_protoflags;
812 int agentfwd_enabled;
813 int X11_fwd_enabled;
814 int remote_bugs;
815 const struct ssh_cipher *cipher;
371e569c 816 void *v1_cipher_ctx;
0183b242 817 void *crcda_ctx;
51470298 818 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 819 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 820 const struct ssh_mac *csmac, *scmac;
e0e1a00d 821 void *cs_mac_ctx, *sc_mac_ctx;
51470298 822 const struct ssh_compress *cscomp, *sccomp;
5366aed8 823 void *cs_comp_ctx, *sc_comp_ctx;
51470298 824 const struct ssh_kex *kex;
825 const struct ssh_signkey *hostkey;
754c0df9 826 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 827 int v2_session_id_len;
27cd7fc2 828 void *kex_ctx;
51470298 829
830 char *savedhost;
831 int savedport;
832 int send_ok;
833 int echoing, editing;
834
835 void *frontend;
836
db219738 837 int ospeed, ispeed; /* temporaries */
51470298 838 int term_width, term_height;
839
840 tree234 *channels; /* indexed by local id */
841 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 842 int ncmode; /* is primary channel direct-tcpip? */
51470298 843 int exitcode;
ac934965 844 int close_expected;
9e296bfa 845 int clean_exit;
51470298 846
fda2feb1 847 tree234 *rportfwds, *portfwds;
51470298 848
849 enum {
850 SSH_STATE_PREPACKET,
851 SSH_STATE_BEFORE_SIZE,
852 SSH_STATE_INTERMED,
853 SSH_STATE_SESSION,
854 SSH_STATE_CLOSED
855 } state;
856
857 int size_needed, eof_needed;
bc06669b 858 int sent_console_eof;
4a202fc6 859 int got_pty; /* affects EOF behaviour on main channel */
51470298 860
590f6a5f 861 struct Packet **queue;
862 int queuelen, queuesize;
863 int queueing;
51470298 864 unsigned char *deferred_send_data;
865 int deferred_len, deferred_size;
866
867 /*
868 * Gross hack: pscp will try to start SFTP but fall back to
869 * scp1 if that fails. This variable is the means by which
870 * scp.c can reach into the SSH code and find out which one it
871 * got.
872 */
873 int fallback_cmd;
874
6bbce591 875 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 876
acab36bc 877 Pkt_KCtx pkt_kctx;
878 Pkt_ACtx pkt_actx;
51470298 879
8def70c3 880 struct X11Display *x11disp;
302121de 881
51470298 882 int version;
ff68564b 883 int conn_throttle_count;
51470298 884 int overall_bufsize;
885 int throttled_all;
886 int v1_stdout_throttling;
a8756193 887 unsigned long v2_outgoing_sequence;
51470298 888
889 int ssh1_rdpkt_crstate;
890 int ssh2_rdpkt_crstate;
891 int do_ssh_init_crstate;
892 int ssh_gotdata_crstate;
51470298 893 int do_ssh1_login_crstate;
b09eaa88 894 int do_ssh1_connection_crstate;
51470298 895 int do_ssh2_transport_crstate;
896 int do_ssh2_authconn_crstate;
897
898 void *do_ssh_init_state;
899 void *do_ssh1_login_state;
900 void *do_ssh2_transport_state;
901 void *do_ssh2_authconn_state;
902
903 struct rdpkt1_state_tag rdpkt1_state;
904 struct rdpkt2_state_tag rdpkt2_state;
905
2e85c969 906 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 907 int protocol_initial_phase_done;
908
1c1a7262 909 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 910 struct Packet *pkt);
911 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 912
913 /*
4a693cfc 914 * We maintain our own copy of a Conf structure here. That way,
915 * when we're passed a new one for reconfiguration, we can check
916 * the differences and potentially reconfigure port forwardings
917 * etc in mid-session.
86916870 918 */
4a693cfc 919 Conf *conf;
920
921 /*
922 * Values cached out of conf so as to avoid the tree234 lookup
923 * cost every time they're used.
924 */
925 int logomitdata;
926
927 /*
928 * Dynamically allocated username string created during SSH
929 * login. Stored in here rather than in the coroutine state so
930 * that it'll be reliably freed if we shut down the SSH session
931 * at some unexpected moment.
932 */
933 char *username;
839f10db 934
935 /*
3d9449a1 936 * Used to transfer data back from async callbacks.
839f10db 937 */
938 void *agent_response;
939 int agent_response_len;
3d9449a1 940 int user_response;
941
942 /*
943 * The SSH connection can be set as `frozen', meaning we are
944 * not currently accepting incoming data from the network. This
945 * is slightly more serious than setting the _socket_ as
946 * frozen, because we may already have had data passed to us
947 * from the network which we need to delay processing until
948 * after the freeze is lifted, so we also need a bufchain to
949 * store that data.
950 */
951 int frozen;
952 bufchain queued_incoming_data;
b09eaa88 953
954 /*
955 * Dispatch table for packet types that we may have to deal
956 * with at any time.
957 */
958 handler_fn_t packet_dispatch[256];
39934deb 959
960 /*
06fadff5 961 * Queues of one-off handler functions for success/failure
962 * indications from a request.
963 */
964 struct queued_handler *qhead, *qtail;
965
966 /*
39934deb 967 * This module deals with sending keepalives.
968 */
969 Pinger pinger;
9442dd57 970
971 /*
972 * Track incoming and outgoing data sizes and time, for
973 * size-based rekeys.
974 */
975 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 976 unsigned long max_data_size;
9442dd57 977 int kex_in_progress;
e6c1536e 978 long next_rekey, last_rekey;
e13bba36 979 char *deferred_rekey_reason; /* points to STATIC string; don't free */
42af6a67 980
981 /*
982 * Fully qualified host name, which we need if doing GSSAPI.
983 */
984 char *fullhostname;
1e00c92b 985
986#ifndef NO_GSSAPI
987 /*
988 * GSSAPI libraries for this session.
989 */
990 struct ssh_gss_liblist *gsslibs;
991#endif
51470298 992};
960e736a 993
382908ad 994#define logevent(s) logevent(ssh->frontend, s)
a8327734 995
996/* logevent, only printf-formatted. */
cbe2d68f 997static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 998{
999 va_list ap;
57356d63 1000 char *buf;
a8327734 1001
1002 va_start(ap, fmt);
57356d63 1003 buf = dupvprintf(fmt, ap);
a8327734 1004 va_end(ap);
57356d63 1005 logevent(buf);
57356d63 1006 sfree(buf);
a8327734 1007}
1008
6b5cf8b4 1009#define bombout(msg) \
1010 do { \
1011 char *text = dupprintf msg; \
ac934965 1012 ssh_do_close(ssh, FALSE); \
6b5cf8b4 1013 logevent(text); \
1014 connection_fatal(ssh->frontend, "%s", text); \
1015 sfree(text); \
1016 } while (0)
a8327734 1017
9a10ecf4 1018/* Functions to leave bits out of the SSH packet log file. */
1019
ff3187f6 1020static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1021{
4a693cfc 1022 if (conf_get_int(ssh->conf, CONF_logomitpass))
ff3187f6 1023 pkt->logmode = blanktype;
9a10ecf4 1024}
1025
ff3187f6 1026static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1027{
4a693cfc 1028 if (ssh->logomitdata)
ff3187f6 1029 pkt->logmode = blanktype;
9a10ecf4 1030}
1031
ff3187f6 1032static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 1033{
ff3187f6 1034 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 1035}
1036
4a693cfc 1037/* Helper function for common bits of parsing ttymodes. */
1038static void parse_ttymodes(Ssh ssh,
c6ccd5c2 1039 void (*do_mode)(void *data, char *mode, char *val),
1040 void *data)
1041{
4a693cfc 1042 char *key, *val;
1043
1044 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1045 val != NULL;
1046 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1047 /*
1048 * val[0] is either 'V', indicating that an explicit value
1049 * follows it, or 'A' indicating that we should pass the
1050 * value through from the local environment via get_ttymode.
1051 */
1052 if (val[0] == 'A')
1053 val = get_ttymode(ssh->frontend, key);
c6ccd5c2 1054 else
4a693cfc 1055 val++; /* skip the 'V' */
c6ccd5c2 1056 if (val)
4a693cfc 1057 do_mode(data, key, val);
c6ccd5c2 1058 }
1059}
1060
32874aea 1061static int ssh_channelcmp(void *av, void *bv)
1062{
1063 struct ssh_channel *a = (struct ssh_channel *) av;
1064 struct ssh_channel *b = (struct ssh_channel *) bv;
1065 if (a->localid < b->localid)
1066 return -1;
1067 if (a->localid > b->localid)
1068 return +1;
dacbd0e8 1069 return 0;
1070}
32874aea 1071static int ssh_channelfind(void *av, void *bv)
1072{
1073 unsigned *a = (unsigned *) av;
1074 struct ssh_channel *b = (struct ssh_channel *) bv;
1075 if (*a < b->localid)
1076 return -1;
1077 if (*a > b->localid)
1078 return +1;
dacbd0e8 1079 return 0;
1080}
1081
bc240b21 1082static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 1083{
1084 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1085 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1086 int i;
bc240b21 1087 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 1088 return i < 0 ? -1 : +1;
bc240b21 1089 if (a->dport > b->dport)
1090 return +1;
1091 if (a->dport < b->dport)
1092 return -1;
1093 return 0;
1094}
1095
1096static int ssh_rportcmp_ssh2(void *av, void *bv)
1097{
1098 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1099 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1100
bc240b21 1101 if (a->sport > b->sport)
d74d141c 1102 return +1;
bc240b21 1103 if (a->sport < b->sport)
1104 return -1;
d74d141c 1105 return 0;
1106}
1107
fda2feb1 1108/*
1109 * Special form of strcmp which can cope with NULL inputs. NULL is
1110 * defined to sort before even the empty string.
1111 */
1112static int nullstrcmp(const char *a, const char *b)
1113{
1114 if (a == NULL && b == NULL)
1115 return 0;
1116 if (a == NULL)
1117 return -1;
1118 if (b == NULL)
1119 return +1;
1120 return strcmp(a, b);
1121}
1122
1123static int ssh_portcmp(void *av, void *bv)
1124{
1125 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1126 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1127 int i;
1128 if (a->type > b->type)
1129 return +1;
1130 if (a->type < b->type)
1131 return -1;
84328ddb 1132 if (a->addressfamily > b->addressfamily)
1133 return +1;
1134 if (a->addressfamily < b->addressfamily)
1135 return -1;
fda2feb1 1136 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1137 return i < 0 ? -1 : +1;
1138 if (a->sport > b->sport)
1139 return +1;
1140 if (a->sport < b->sport)
1141 return -1;
1142 if (a->type != 'D') {
1143 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1144 return i < 0 ? -1 : +1;
1145 if (a->dport > b->dport)
1146 return +1;
1147 if (a->dport < b->dport)
1148 return -1;
1149 }
1150 return 0;
1151}
1152
51470298 1153static int alloc_channel_id(Ssh ssh)
32874aea 1154{
260f3dec 1155 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1156 unsigned low, high, mid;
d2371c81 1157 int tsize;
1158 struct ssh_channel *c;
1159
1160 /*
1161 * First-fit allocation of channel numbers: always pick the
1162 * lowest unused one. To do this, binary-search using the
1163 * counted B-tree to find the largest channel ID which is in a
1164 * contiguous sequence from the beginning. (Precisely
1165 * everything in that sequence must have ID equal to its tree
1166 * index plus CHANNEL_NUMBER_OFFSET.)
1167 */
51470298 1168 tsize = count234(ssh->channels);
d2371c81 1169
32874aea 1170 low = -1;
1171 high = tsize;
d2371c81 1172 while (high - low > 1) {
1173 mid = (high + low) / 2;
51470298 1174 c = index234(ssh->channels, mid);
d2371c81 1175 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1176 low = mid; /* this one is fine */
1177 else
1178 high = mid; /* this one is past it */
1179 }
1180 /*
1181 * Now low points to either -1, or the tree index of the
1182 * largest ID in the initial sequence.
1183 */
1184 {
1185 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1186 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1187 }
1188 return low + 1 + CHANNEL_NUMBER_OFFSET;
1189}
1190
edd0cb8a 1191static void c_write_stderr(int trusted, const char *buf, int len)
1192{
1193 int i;
1194 for (i = 0; i < len; i++)
667deca9 1195 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1196 fputc(buf[i], stderr);
1197}
1198
9fab77dc 1199static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1200{
edd0cb8a 1201 if (flags & FLAG_STDERR)
1202 c_write_stderr(1, buf, len);
1203 else
1204 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1205}
1206
9fab77dc 1207static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1208{
edd0cb8a 1209 if (flags & FLAG_STDERR)
1210 c_write_stderr(0, buf, len);
1211 else
1212 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1213}
1214
9fab77dc 1215static void c_write_str(Ssh ssh, const char *buf)
32874aea 1216{
51470298 1217 c_write(ssh, buf, strlen(buf));
1408a877 1218}
1219
ff3187f6 1220static void ssh_free_packet(struct Packet *pkt)
1221{
1222 sfree(pkt->data);
1223 sfree(pkt);
1224}
1225static struct Packet *ssh_new_packet(void)
1226{
1227 struct Packet *pkt = snew(struct Packet);
1228
dacd8872 1229 pkt->body = pkt->data = NULL;
ff3187f6 1230 pkt->maxlen = 0;
1231 pkt->logmode = PKTLOG_EMIT;
1232 pkt->nblanks = 0;
1233 pkt->blanks = NULL;
1234
1235 return pkt;
1236}
1237
fb09bf1c 1238/*
1239 * Collect incoming data in the incoming packet buffer.
e5574168 1240 * Decipher and verify the packet when it is completely read.
1241 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1242 * Update the *data and *datalen variables.
ff3187f6 1243 * Return a Packet structure when a packet is completed.
fb09bf1c 1244 */
ff3187f6 1245static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1246{
51470298 1247 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1248
51470298 1249 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1250
ff3187f6 1251 st->pktin = ssh_new_packet();
1252
1253 st->pktin->type = 0;
1254 st->pktin->length = 0;
374330e2 1255
57476f6b 1256 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1257 while ((*datalen) == 0)
ff3187f6 1258 crReturn(NULL);
57476f6b 1259 st->len = (st->len << 8) + **data;
fb09bf1c 1260 (*data)++, (*datalen)--;
1261 }
374330e2 1262
57476f6b 1263 st->pad = 8 - (st->len % 8);
1264 st->biglen = st->len + st->pad;
ff3187f6 1265 st->pktin->length = st->len - 5;
fb09bf1c 1266
ae0500e5 1267 if (st->biglen < 0) {
1268 bombout(("Extremely large packet length from server suggests"
1269 " data stream corruption"));
ff3187f6 1270 ssh_free_packet(st->pktin);
1271 crStop(NULL);
ae0500e5 1272 }
1273
ff3187f6 1274 st->pktin->maxlen = st->biglen;
1275 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1276
57476f6b 1277 st->to_read = st->biglen;
ff3187f6 1278 st->p = st->pktin->data;
57476f6b 1279 while (st->to_read > 0) {
32874aea 1280 st->chunk = st->to_read;
fb09bf1c 1281 while ((*datalen) == 0)
ff3187f6 1282 crReturn(NULL);
57476f6b 1283 if (st->chunk > (*datalen))
1284 st->chunk = (*datalen);
1285 memcpy(st->p, *data, st->chunk);
1286 *data += st->chunk;
1287 *datalen -= st->chunk;
1288 st->p += st->chunk;
1289 st->to_read -= st->chunk;
fb09bf1c 1290 }
374330e2 1291
ff3187f6 1292 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1293 st->biglen, NULL)) {
6b5cf8b4 1294 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1295 ssh_free_packet(st->pktin);
1296 crStop(NULL);
9a3a93a5 1297 }
1298
51470298 1299 if (ssh->cipher)
ff3187f6 1300 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1301
ff3187f6 1302 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1303 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1304 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1305 bombout(("Incorrect CRC received on packet"));
ff3187f6 1306 ssh_free_packet(st->pktin);
1307 crStop(NULL);
fb09bf1c 1308 }
572f871e 1309
ff3187f6 1310 st->pktin->body = st->pktin->data + st->pad + 1;
1311 st->pktin->savedpos = 0;
4ba9b64b 1312
51470298 1313 if (ssh->v1_compressing) {
4ba9b64b 1314 unsigned char *decompblk;
1315 int decomplen;
36b8d9bb 1316 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1317 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1318 &decompblk, &decomplen)) {
1319 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1320 ssh_free_packet(st->pktin);
1321 crStop(NULL);
36b8d9bb 1322 }
4ba9b64b 1323
ff3187f6 1324 if (st->pktin->maxlen < st->pad + decomplen) {
1325 st->pktin->maxlen = st->pad + decomplen;
1326 st->pktin->data = sresize(st->pktin->data,
1327 st->pktin->maxlen + APIEXTRA,
3d88e64d 1328 unsigned char);
ff3187f6 1329 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1330 }
1331
ff3187f6 1332 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1333 sfree(decompblk);
ff3187f6 1334 st->pktin->length = decomplen - 1;
4ba9b64b 1335 }
1336
ff3187f6 1337 st->pktin->type = st->pktin->body[-1];
00db133f 1338
9a10ecf4 1339 /*
1340 * Log incoming packet, possibly omitting sensitive fields.
1341 */
1342 if (ssh->logctx) {
1343 int nblanks = 0;
1344 struct logblank_t blank;
4a693cfc 1345 if (ssh->logomitdata) {
9a10ecf4 1346 int do_blank = FALSE, blank_prefix = 0;
1347 /* "Session data" packets - omit the data field */
ff3187f6 1348 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1349 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1350 do_blank = TRUE; blank_prefix = 4;
a2724fba 1351 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1352 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1353 }
1354 if (do_blank) {
1355 blank.offset = blank_prefix;
ff3187f6 1356 blank.len = st->pktin->length;
9a10ecf4 1357 blank.type = PKTLOG_OMIT;
1358 nblanks = 1;
1359 }
1360 }
a8327734 1361 log_packet(ssh->logctx,
ff3187f6 1362 PKT_INCOMING, st->pktin->type,
1363 ssh1_pkt_type(st->pktin->type),
1364 st->pktin->body, st->pktin->length,
0d13bfcd 1365 nblanks, &blank, NULL);
9a10ecf4 1366 }
00db133f 1367
ff3187f6 1368 crFinish(st->pktin);
fb09bf1c 1369}
1370
ff3187f6 1371static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1372{
51470298 1373 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1374
51470298 1375 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1376
ff3187f6 1377 st->pktin = ssh_new_packet();
1378
1379 st->pktin->type = 0;
1380 st->pktin->length = 0;
51470298 1381 if (ssh->sccipher)
1382 st->cipherblk = ssh->sccipher->blksize;
e5574168 1383 else
32874aea 1384 st->cipherblk = 8;
960e736a 1385 if (st->cipherblk < 8)
32874aea 1386 st->cipherblk = 8;
9916cc1e 1387 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
960e736a 1388
9916cc1e 1389 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1390 ssh->scmac) {
1391 /*
1392 * When dealing with a CBC-mode cipher, we want to avoid the
1393 * possibility of an attacker's tweaking the ciphertext stream
1394 * so as to cause us to feed the same block to the block
1395 * cipher more than once and thus leak information
1396 * (VU#958563). The way we do this is not to take any
1397 * decisions on the basis of anything we've decrypted until
1398 * we've verified it with a MAC. That includes the packet
1399 * length, so we just read data and check the MAC repeatedly,
1400 * and when the MAC passes, see if the length we've got is
1401 * plausible.
1402 */
1403
1404 /* May as well allocate the whole lot now. */
1405 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1406 unsigned char);
1407
1408 /* Read an amount corresponding to the MAC. */
1409 for (st->i = 0; st->i < st->maclen; st->i++) {
1410 while ((*datalen) == 0)
1411 crReturn(NULL);
1412 st->pktin->data[st->i] = *(*data)++;
1413 (*datalen)--;
1414 }
e5574168 1415
9916cc1e 1416 st->packetlen = 0;
1417 {
1418 unsigned char seq[4];
1419 ssh->scmac->start(ssh->sc_mac_ctx);
1420 PUT_32BIT(seq, st->incoming_sequence);
1421 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1422 }
4252c9cc 1423
9916cc1e 1424 for (;;) { /* Once around this loop per cipher block. */
1425 /* Read another cipher-block's worth, and tack it onto the end. */
1426 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1427 while ((*datalen) == 0)
1428 crReturn(NULL);
1429 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1430 (*datalen)--;
1431 }
1432 /* Decrypt one more block (a little further back in the stream). */
1433 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1434 st->pktin->data + st->packetlen,
1435 st->cipherblk);
1436 /* Feed that block to the MAC. */
1437 ssh->scmac->bytes(ssh->sc_mac_ctx,
1438 st->pktin->data + st->packetlen, st->cipherblk);
1439 st->packetlen += st->cipherblk;
1440 /* See if that gives us a valid packet. */
1441 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1442 st->pktin->data + st->packetlen) &&
1443 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1444 break;
1445 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1446 bombout(("No valid incoming packet found"));
1447 ssh_free_packet(st->pktin);
1448 crStop(NULL);
1449 }
1450 }
1451 st->pktin->maxlen = st->packetlen + st->maclen;
1452 st->pktin->data = sresize(st->pktin->data,
1453 st->pktin->maxlen + APIEXTRA,
1454 unsigned char);
1455 } else {
1456 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1457
1458 /*
1459 * Acquire and decrypt the first block of the packet. This will
1460 * contain the length and padding details.
1461 */
1462 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1463 while ((*datalen) == 0)
1464 crReturn(NULL);
1465 st->pktin->data[st->i] = *(*data)++;
1466 (*datalen)--;
1467 }
e5574168 1468
9916cc1e 1469 if (ssh->sccipher)
1470 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1471 st->pktin->data, st->cipherblk);
1472
1473 /*
1474 * Now get the length figure.
1475 */
1476 st->len = GET_32BIT(st->pktin->data);
1477
1478 /*
1479 * _Completely_ silly lengths should be stomped on before they
1480 * do us any more damage.
1481 */
1482 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1483 (st->len + 4) % st->cipherblk != 0) {
1484 bombout(("Incoming packet was garbled on decryption"));
1485 ssh_free_packet(st->pktin);
1486 crStop(NULL);
1487 }
e5574168 1488
9916cc1e 1489 /*
1490 * So now we can work out the total packet length.
1491 */
1492 st->packetlen = st->len + 4;
1493
1494 /*
1495 * Allocate memory for the rest of the packet.
1496 */
1497 st->pktin->maxlen = st->packetlen + st->maclen;
1498 st->pktin->data = sresize(st->pktin->data,
1499 st->pktin->maxlen + APIEXTRA,
1500 unsigned char);
1501
1502 /*
1503 * Read and decrypt the remainder of the packet.
1504 */
1505 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1506 st->i++) {
1507 while ((*datalen) == 0)
1508 crReturn(NULL);
1509 st->pktin->data[st->i] = *(*data)++;
1510 (*datalen)--;
1511 }
1512 /* Decrypt everything _except_ the MAC. */
1513 if (ssh->sccipher)
1514 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1515 st->pktin->data + st->cipherblk,
1516 st->packetlen - st->cipherblk);
1517
1518 /*
1519 * Check the MAC.
1520 */
1521 if (ssh->scmac
1522 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1523 st->len + 4, st->incoming_sequence)) {
1524 bombout(("Incorrect MAC received on packet"));
1525 ssh_free_packet(st->pktin);
1526 crStop(NULL);
1527 }
1528 }
1529 /* Get and sanity-check the amount of random padding. */
1530 st->pad = st->pktin->data[4];
1531 if (st->pad < 4 || st->len - st->pad < 1) {
1532 bombout(("Invalid padding length on received packet"));
ff3187f6 1533 ssh_free_packet(st->pktin);
1534 crStop(NULL);
717dc483 1535 }
717dc483 1536 /*
e5574168 1537 * This enables us to deduce the payload length.
1538 */
960e736a 1539 st->payload = st->len - st->pad - 1;
e5574168 1540
ff3187f6 1541 st->pktin->length = st->payload + 5;
9442dd57 1542 st->pktin->encrypted_len = st->packetlen;
1543
b09eaa88 1544 st->pktin->sequence = st->incoming_sequence++;
e5574168 1545
4ba9b64b 1546 /*
1547 * Decompress packet payload.
1548 */
1549 {
1550 unsigned char *newpayload;
1551 int newlen;
51470298 1552 if (ssh->sccomp &&
5366aed8 1553 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1554 st->pktin->data + 5, st->pktin->length - 5,
51470298 1555 &newpayload, &newlen)) {
ff3187f6 1556 if (st->pktin->maxlen < newlen + 5) {
1557 st->pktin->maxlen = newlen + 5;
1558 st->pktin->data = sresize(st->pktin->data,
1559 st->pktin->maxlen + APIEXTRA,
3d88e64d 1560 unsigned char);
4ba9b64b 1561 }
ff3187f6 1562 st->pktin->length = 5 + newlen;
1563 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1564 sfree(newpayload);
4ba9b64b 1565 }
1566 }
1567
ff3187f6 1568 st->pktin->savedpos = 6;
1569 st->pktin->body = st->pktin->data;
1570 st->pktin->type = st->pktin->data[5];
e5574168 1571
9a10ecf4 1572 /*
1573 * Log incoming packet, possibly omitting sensitive fields.
1574 */
1575 if (ssh->logctx) {
1576 int nblanks = 0;
1577 struct logblank_t blank;
4a693cfc 1578 if (ssh->logomitdata) {
9a10ecf4 1579 int do_blank = FALSE, blank_prefix = 0;
1580 /* "Session data" packets - omit the data field */
ff3187f6 1581 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1582 do_blank = TRUE; blank_prefix = 8;
a2724fba 1583 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1584 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1585 }
1586 if (do_blank) {
1587 blank.offset = blank_prefix;
ff3187f6 1588 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1589 blank.type = PKTLOG_OMIT;
1590 nblanks = 1;
1591 }
1592 }
ff3187f6 1593 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1594 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1595 st->pktin->type),
ff3187f6 1596 st->pktin->data+6, st->pktin->length-6,
0d13bfcd 1597 nblanks, &blank, &st->pktin->sequence);
9a10ecf4 1598 }
00db133f 1599
ff3187f6 1600 crFinish(st->pktin);
e5574168 1601}
1602
dacd8872 1603static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1604{
dacd8872 1605 int pad, biglen, i, pktoffs;
374330e2 1606 unsigned long crc;
fd7a4aad 1607#ifdef __SC__
1608 /*
1609 * XXX various versions of SC (including 8.8.4) screw up the
1610 * register allocation in this function and use the same register
1611 * (D6) for len and as a temporary, with predictable results. The
1612 * following sledgehammer prevents this.
1613 */
1614 volatile
1615#endif
1616 int len;
374330e2 1617
a8327734 1618 if (ssh->logctx)
dacd8872 1619 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1620 ssh1_pkt_type(pkt->data[12]),
1621 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1622 pkt->nblanks, pkt->blanks, NULL);
ff3187f6 1623 sfree(pkt->blanks); pkt->blanks = NULL;
1624 pkt->nblanks = 0;
00db133f 1625
51470298 1626 if (ssh->v1_compressing) {
4ba9b64b 1627 unsigned char *compblk;
1628 int complen;
5366aed8 1629 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1630 pkt->data + 12, pkt->length - 12,
4ba9b64b 1631 &compblk, &complen);
48406e6b 1632 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1633 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1634 sfree(compblk);
dacd8872 1635 pkt->length = complen + 12;
4ba9b64b 1636 }
1637
dacd8872 1638 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1639 pkt->length += 4;
1640 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1641 pad = 8 - (len % 8);
dacd8872 1642 pktoffs = 8 - pad;
1643 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1644
dacd8872 1645 for (i = pktoffs; i < 4+8; i++)
1646 pkt->data[i] = random_byte();
1647 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1648 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1649 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1650
51470298 1651 if (ssh->cipher)
dacd8872 1652 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1653 pkt->data + pktoffs + 4, biglen);
374330e2 1654
dacd8872 1655 if (offset_p) *offset_p = pktoffs;
1656 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1657}
1658
bf8a49a1 1659static int s_write(Ssh ssh, void *data, int len)
1660{
ff05dfef 1661 if (ssh->logctx)
0d13bfcd 1662 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1663 0, NULL, NULL);
bf8a49a1 1664 return sk_write(ssh->s, (char *)data, len);
1665}
1666
ff3187f6 1667static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1668{
dacd8872 1669 int len, backlog, offset;
1670 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1671 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1672 if (backlog > SSH_MAX_BACKLOG)
51470298 1673 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1674 ssh_free_packet(pkt);
39065bed 1675}
1676
ff3187f6 1677static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1678{
dacd8872 1679 int len, offset;
1680 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1681 if (ssh->deferred_len + len > ssh->deferred_size) {
1682 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1683 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1684 ssh->deferred_size,
1685 unsigned char);
39065bed 1686 }
dacd8872 1687 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1688 pkt->data + offset, len);
51470298 1689 ssh->deferred_len += len;
dacd8872 1690 ssh_free_packet(pkt);
374330e2 1691}
1692
fb09bf1c 1693/*
dacd8872 1694 * Construct a SSH-1 packet with the specified contents.
1695 * (This all-at-once interface used to be the only one, but now SSH-1
1696 * packets can also be constructed incrementally.)
fb09bf1c 1697 */
dacd8872 1698static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1699{
dacd8872 1700 int argtype;
7cca0d81 1701 Bignum bn;
ff3187f6 1702 struct Packet *pkt;
fb09bf1c 1703
dacd8872 1704 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1705
dacd8872 1706 while ((argtype = va_arg(ap, int)) != PKT_END) {
1707 unsigned char *argp, argchar;
8a9977e5 1708 char *sargp;
dacd8872 1709 unsigned long argint;
1710 int arglen;
fb09bf1c 1711 switch (argtype) {
9a10ecf4 1712 /* Actual fields in the packet */
fb09bf1c 1713 case PKT_INT:
dacd8872 1714 argint = va_arg(ap, int);
1715 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1716 break;
1717 case PKT_CHAR:
dacd8872 1718 argchar = (unsigned char) va_arg(ap, int);
1719 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1720 break;
1721 case PKT_DATA:
dacd8872 1722 argp = va_arg(ap, unsigned char *);
1723 arglen = va_arg(ap, int);
1724 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1725 break;
1726 case PKT_STR:
8a9977e5 1727 sargp = va_arg(ap, char *);
1728 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1729 break;
7cca0d81 1730 case PKT_BIGNUM:
dacd8872 1731 bn = va_arg(ap, Bignum);
1732 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1733 break;
1734 /* Tokens for modifications to packet logging */
1735 case PKTT_PASSWORD:
ff3187f6 1736 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1737 break;
1738 case PKTT_DATA:
ff3187f6 1739 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1740 break;
9a10ecf4 1741 case PKTT_OTHER:
ff3187f6 1742 end_log_omission(ssh, pkt);
9a10ecf4 1743 break;
1744 }
fb09bf1c 1745 }
ff3187f6 1746
1747 return pkt;
39065bed 1748}
fb09bf1c 1749
51470298 1750static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1751{
ff3187f6 1752 struct Packet *pkt;
dacd8872 1753 va_list ap;
1754 va_start(ap, pkttype);
1755 pkt = construct_packet(ssh, pkttype, ap);
1756 va_end(ap);
ff3187f6 1757 s_wrpkt(ssh, pkt);
fb09bf1c 1758}
1759
51470298 1760static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1761{
ff3187f6 1762 struct Packet *pkt;
dacd8872 1763 va_list ap;
1764 va_start(ap, pkttype);
1765 pkt = construct_packet(ssh, pkttype, ap);
1766 va_end(ap);
ff3187f6 1767 s_wrpkt_defer(ssh, pkt);
39065bed 1768}
1769
32874aea 1770static int ssh_versioncmp(char *a, char *b)
1771{
9697bfd2 1772 char *ae, *be;
1773 unsigned long av, bv;
1774
43aa02a7 1775 av = strtoul(a, &ae, 10);
1776 bv = strtoul(b, &be, 10);
32874aea 1777 if (av != bv)
1778 return (av < bv ? -1 : +1);
1779 if (*ae == '.')
1780 ae++;
1781 if (*be == '.')
1782 be++;
43aa02a7 1783 av = strtoul(ae, &ae, 10);
1784 bv = strtoul(be, &be, 10);
32874aea 1785 if (av != bv)
1786 return (av < bv ? -1 : +1);
9697bfd2 1787 return 0;
1788}
1789
e5574168 1790/*
a92dd380 1791 * Utility routines for putting an SSH-protocol `string' and
b672f405 1792 * `uint32' into a hash state.
e5574168 1793 */
b672f405 1794static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1795{
e5574168 1796 unsigned char lenblk[4];
e5574168 1797 PUT_32BIT(lenblk, len);
b672f405 1798 h->bytes(s, lenblk, 4);
1799 h->bytes(s, str, len);
e5574168 1800}
1801
b672f405 1802static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1803{
a92dd380 1804 unsigned char intblk[4];
1805 PUT_32BIT(intblk, i);
b672f405 1806 h->bytes(s, intblk, 4);
a92dd380 1807}
1808
7cca0d81 1809/*
dacd8872 1810 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1811 */
dacd8872 1812static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1813{
ff3187f6 1814 if (pkt->maxlen < length) {
dacd8872 1815 unsigned char *body = pkt->body;
3d71de0b 1816 int offset = body ? body - pkt->data : 0;
ff3187f6 1817 pkt->maxlen = length + 256;
1818 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1819 if (body) pkt->body = pkt->data + offset;
7cca0d81 1820 }
783415f8 1821}
dacd8872 1822static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1823{
ff3187f6 1824 if (pkt->logmode != PKTLOG_EMIT) {
1825 pkt->nblanks++;
1826 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1827 assert(pkt->body);
1828 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1829 (pkt->body - pkt->data);
ff3187f6 1830 pkt->blanks[pkt->nblanks-1].len = len;
1831 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1832 }
1833 pkt->length += len;
dacd8872 1834 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1835 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1836}
dacd8872 1837static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1838{
dacd8872 1839 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1840}
ff3187f6 1841static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1842{
dacd8872 1843 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1844}
dacd8872 1845static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1846{
7cca0d81 1847 unsigned char x[4];
1848 PUT_32BIT(x, value);
dacd8872 1849 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1850}
dacd8872 1851static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1852{
dacd8872 1853 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1854 pkt->savedpos = pkt->length;
7cca0d81 1855}
dacd8872 1856static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1857{
dacd8872 1858 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1859 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1860}
dacd8872 1861static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1862{
dacd8872 1863 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1864 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1865}
dacd8872 1866static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1867{
1868 ssh_pkt_addstring_start(pkt);
1869 ssh_pkt_addstring_str(pkt, data);
1870}
1871static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1872{
dacd8872 1873 int len = ssh1_bignum_length(b);
8a9977e5 1874 unsigned char *data = snewn(len, unsigned char);
dacd8872 1875 (void) ssh1_write_bignum(data, b);
1876 ssh_pkt_adddata(pkt, data, len);
1877 sfree(data);
7cca0d81 1878}
d8baa528 1879static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1880{
7cca0d81 1881 unsigned char *p;
32874aea 1882 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1883 p = snewn(n + 1, unsigned char);
7cca0d81 1884 p[0] = 0;
3709bfe9 1885 for (i = 1; i <= n; i++)
32874aea 1886 p[i] = bignum_byte(b, n - i);
7cca0d81 1887 i = 0;
32874aea 1888 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1889 i++;
1890 memmove(p, p + i, n + 1 - i);
1891 *len = n + 1 - i;
7cca0d81 1892 return p;
1893}
ff3187f6 1894static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1895{
7cca0d81 1896 unsigned char *p;
1897 int len;
1898 p = ssh2_mpint_fmt(b, &len);
dacd8872 1899 ssh_pkt_addstring_start(pkt);
1900 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1901 sfree(p);
7cca0d81 1902}
b185170a 1903
dacd8872 1904static struct Packet *ssh1_pkt_init(int pkt_type)
1905{
1906 struct Packet *pkt = ssh_new_packet();
1907 pkt->length = 4 + 8; /* space for length + max padding */
1908 ssh_pkt_addbyte(pkt, pkt_type);
1909 pkt->body = pkt->data + pkt->length;
1910 return pkt;
1911}
1912
1913/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1914#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1915#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1916#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1917#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1918#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1919#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1920#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1921#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1922
1923static struct Packet *ssh2_pkt_init(int pkt_type)
1924{
1925 struct Packet *pkt = ssh_new_packet();
3d71de0b 1926 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1927 pkt->forcepad = 0;
1928 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1929 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1930 return pkt;
1931}
1932
b185170a 1933/*
2e85c969 1934 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1935 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1936 * pkt->data. Total length is returned.
b185170a 1937 */
ff3187f6 1938static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1939{
7cca0d81 1940 int cipherblk, maclen, padding, i;
7cca0d81 1941
a8327734 1942 if (ssh->logctx)
ff3187f6 1943 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1944 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1945 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1946 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
ff3187f6 1947 sfree(pkt->blanks); pkt->blanks = NULL;
1948 pkt->nblanks = 0;
00db133f 1949
7cca0d81 1950 /*
4ba9b64b 1951 * Compress packet payload.
1952 */
4ba9b64b 1953 {
1954 unsigned char *newpayload;
1955 int newlen;
51470298 1956 if (ssh->cscomp &&
ff3187f6 1957 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1958 pkt->length - 5,
51470298 1959 &newpayload, &newlen)) {
ff3187f6 1960 pkt->length = 5;
1961 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1962 sfree(newpayload);
4ba9b64b 1963 }
1964 }
1965
1966 /*
7cca0d81 1967 * Add padding. At least four bytes, and must also bring total
1968 * length (minus MAC) up to a multiple of the block size.
95d2d262 1969 * If pkt->forcepad is set, make sure the packet is at least that size
1970 * after padding.
7cca0d81 1971 */
51470298 1972 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1973 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1974 padding = 4;
95d2d262 1975 if (pkt->length + padding < pkt->forcepad)
1976 padding = pkt->forcepad - pkt->length;
32874aea 1977 padding +=
ff3187f6 1978 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1979 assert(padding <= 255);
51470298 1980 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1981 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1982 pkt->data[4] = padding;
7cca0d81 1983 for (i = 0; i < padding; i++)
ff3187f6 1984 pkt->data[pkt->length + i] = random_byte();
1985 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1986 if (ssh->csmac)
ff3187f6 1987 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1988 pkt->length + padding,
51470298 1989 ssh->v2_outgoing_sequence);
1990 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1991
1992 if (ssh->cscipher)
371e569c 1993 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1994 pkt->data, pkt->length + padding);
51470298 1995
9442dd57 1996 pkt->encrypted_len = pkt->length + padding;
1997
ff3187f6 1998 /* Ready-to-send packet starts at pkt->data. We return length. */
1999 return pkt->length + padding + maclen;
b185170a 2000}
2001
2002/*
590f6a5f 2003 * Routines called from the main SSH code to send packets. There
2004 * are quite a few of these, because we have two separate
2005 * mechanisms for delaying the sending of packets:
2006 *
2007 * - In order to send an IGNORE message and a password message in
2008 * a single fixed-length blob, we require the ability to
2009 * concatenate the encrypted forms of those two packets _into_ a
2010 * single blob and then pass it to our <network.h> transport
2011 * layer in one go. Hence, there's a deferment mechanism which
2012 * works after packet encryption.
2013 *
2014 * - In order to avoid sending any connection-layer messages
2015 * during repeat key exchange, we have to queue up any such
2016 * outgoing messages _before_ they are encrypted (and in
2017 * particular before they're allocated sequence numbers), and
2018 * then send them once we've finished.
2019 *
2020 * I call these mechanisms `defer' and `queue' respectively, so as
2021 * to distinguish them reasonably easily.
2022 *
2023 * The functions send_noqueue() and defer_noqueue() free the packet
2024 * structure they are passed. Every outgoing packet goes through
2025 * precisely one of these functions in its life; packets passed to
2026 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2027 * these or get queued, and then when the queue is later emptied
2028 * the packets are all passed to defer_noqueue().
97ab28d7 2029 *
2030 * When using a CBC-mode cipher, it's necessary to ensure that an
2031 * attacker can't provide data to be encrypted using an IV that they
2032 * know. We ensure this by prefixing each packet that might contain
2033 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2034 * mechanism, so in this case send_noqueue() ends up redirecting to
2035 * defer_noqueue(). If you don't like this inefficiency, don't use
2036 * CBC.
b185170a 2037 */
590f6a5f 2038
97ab28d7 2039static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2040static void ssh_pkt_defersend(Ssh);
2041
590f6a5f 2042/*
2e85c969 2043 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 2044 */
2045static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 2046{
5471d09a 2047 int len;
2048 int backlog;
97ab28d7 2049 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2050 /* We need to send two packets, so use the deferral mechanism. */
2051 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2052 ssh_pkt_defersend(ssh);
2053 return;
2054 }
ff3187f6 2055 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 2056 backlog = s_write(ssh, pkt->data, len);
5471d09a 2057 if (backlog > SSH_MAX_BACKLOG)
51470298 2058 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2059
2060 ssh->outgoing_data_size += pkt->encrypted_len;
2061 if (!ssh->kex_in_progress &&
d57f70af 2062 ssh->max_data_size != 0 &&
2063 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2064 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2065
ff3187f6 2066 ssh_free_packet(pkt);
b185170a 2067}
2068
2069/*
2e85c969 2070 * Defer an SSH-2 packet.
b185170a 2071 */
97ab28d7 2072static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 2073{
97ab28d7 2074 int len;
2075 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
cf6ddb95 2076 ssh->deferred_len == 0 && !noignore &&
2077 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
97ab28d7 2078 /*
2079 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2080 * get encrypted with a known IV.
2081 */
2082 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 2083 ssh2_pkt_addstring_start(ipkt);
97ab28d7 2084 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2085 }
2086 len = ssh2_pkt_construct(ssh, pkt);
51470298 2087 if (ssh->deferred_len + len > ssh->deferred_size) {
2088 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 2089 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2090 ssh->deferred_size,
2091 unsigned char);
b185170a 2092 }
ff3187f6 2093 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 2094 ssh->deferred_len += len;
9442dd57 2095 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 2096 ssh_free_packet(pkt);
b185170a 2097}
2098
2099/*
2e85c969 2100 * Queue an SSH-2 packet.
590f6a5f 2101 */
2102static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2103{
2104 assert(ssh->queueing);
2105
2106 if (ssh->queuelen >= ssh->queuesize) {
2107 ssh->queuesize = ssh->queuelen + 32;
2108 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2109 }
2110
2111 ssh->queue[ssh->queuelen++] = pkt;
2112}
2113
2114/*
2115 * Either queue or send a packet, depending on whether queueing is
2116 * set.
2117 */
2118static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2119{
2120 if (ssh->queueing)
2121 ssh2_pkt_queue(ssh, pkt);
2122 else
2123 ssh2_pkt_send_noqueue(ssh, pkt);
2124}
2125
2126/*
2127 * Either queue or defer a packet, depending on whether queueing is
2128 * set.
2129 */
2130static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2131{
2132 if (ssh->queueing)
2133 ssh2_pkt_queue(ssh, pkt);
2134 else
97ab28d7 2135 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 2136}
2137
2138/*
b185170a 2139 * Send the whole deferred data block constructed by
2e85c969 2140 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 2141 *
2142 * The expected use of the defer mechanism is that you call
2143 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2144 * not currently queueing, this simply sets up deferred_send_data
2145 * and then sends it. If we _are_ currently queueing, the calls to
2146 * ssh2_pkt_defer() put the deferred packets on to the queue
2147 * instead, and therefore ssh_pkt_defersend() has no deferred data
2148 * to send. Hence, there's no need to make it conditional on
2149 * ssh->queueing.
b185170a 2150 */
51470298 2151static void ssh_pkt_defersend(Ssh ssh)
32874aea 2152{
5471d09a 2153 int backlog;
bf8a49a1 2154 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 2155 ssh->deferred_len = ssh->deferred_size = 0;
2156 sfree(ssh->deferred_send_data);
2157 ssh->deferred_send_data = NULL;
5471d09a 2158 if (backlog > SSH_MAX_BACKLOG)
51470298 2159 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2160
2161 ssh->outgoing_data_size += ssh->deferred_data_size;
2162 if (!ssh->kex_in_progress &&
d57f70af 2163 ssh->max_data_size != 0 &&
2164 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2165 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2166 ssh->deferred_data_size = 0;
7cca0d81 2167}
2168
590f6a5f 2169/*
18524056 2170 * Send a packet whose length needs to be disguised (typically
2171 * passwords or keyboard-interactive responses).
2172 */
2173static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2174 int padsize)
2175{
2176#if 0
2177 if (0) {
2178 /*
2179 * The simplest way to do this is to adjust the
2180 * variable-length padding field in the outgoing packet.
2181 *
2182 * Currently compiled out, because some Cisco SSH servers
2183 * don't like excessively padded packets (bah, why's it
2184 * always Cisco?)
2185 */
2186 pkt->forcepad = padsize;
2187 ssh2_pkt_send(ssh, pkt);
2188 } else
2189#endif
2190 {
2191 /*
2192 * If we can't do that, however, an alternative approach is
2193 * to use the pkt_defer mechanism to bundle the packet
2194 * tightly together with an SSH_MSG_IGNORE such that their
2195 * combined length is a constant. So first we construct the
2196 * final form of this packet and defer its sending.
2197 */
2198 ssh2_pkt_defer(ssh, pkt);
2199
2200 /*
2201 * Now construct an SSH_MSG_IGNORE which includes a string
2202 * that's an exact multiple of the cipher block size. (If
2203 * the cipher is NULL so that the block size is
2204 * unavailable, we don't do this trick at all, because we
2205 * gain nothing by it.)
2206 */
cf6ddb95 2207 if (ssh->cscipher &&
2208 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
18524056 2209 int stringlen, i;
2210
2211 stringlen = (256 - ssh->deferred_len);
2212 stringlen += ssh->cscipher->blksize - 1;
2213 stringlen -= (stringlen % ssh->cscipher->blksize);
2214 if (ssh->cscomp) {
2215 /*
2216 * Temporarily disable actual compression, so we
2217 * can guarantee to get this string exactly the
2218 * length we want it. The compression-disabling
2219 * routine should return an integer indicating how
2220 * many bytes we should adjust our string length
2221 * by.
2222 */
2223 stringlen -=
2224 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2225 }
2226 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2227 ssh2_pkt_addstring_start(pkt);
2228 for (i = 0; i < stringlen; i++) {
2229 char c = (char) random_byte();
2230 ssh2_pkt_addstring_data(pkt, &c, 1);
2231 }
2232 ssh2_pkt_defer(ssh, pkt);
2233 }
2234 ssh_pkt_defersend(ssh);
2235 }
2236}
2237
2238/*
2e85c969 2239 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2240 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2241 * packets that needed to be lumped together.
2242 */
2243static void ssh2_pkt_queuesend(Ssh ssh)
2244{
2245 int i;
2246
2247 assert(!ssh->queueing);
2248
2249 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2250 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2251 ssh->queuelen = 0;
2252
2253 ssh_pkt_defersend(ssh);
2254}
2255
7cca0d81 2256#if 0
32874aea 2257void bndebug(char *string, Bignum b)
2258{
7cca0d81 2259 unsigned char *p;
2260 int i, len;
2261 p = ssh2_mpint_fmt(b, &len);
2262 debug(("%s", string));
2263 for (i = 0; i < len; i++)
32874aea 2264 debug((" %02x", p[i]));
765c4200 2265 debug(("\n"));
dcbde236 2266 sfree(p);
7cca0d81 2267}
2268#endif
2269
b672f405 2270static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2271{
7cca0d81 2272 unsigned char *p;
2273 int len;
2274 p = ssh2_mpint_fmt(b, &len);
b672f405 2275 hash_string(h, s, p, len);
dcbde236 2276 sfree(p);
7cca0d81 2277}
2278
2279/*
2e85c969 2280 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2281 */
ff3187f6 2282static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2283{
7cca0d81 2284 unsigned long value;
ff3187f6 2285 if (pkt->length - pkt->savedpos < 4)
32874aea 2286 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2287 value = GET_32BIT(pkt->body + pkt->savedpos);
2288 pkt->savedpos += 4;
7cca0d81 2289 return value;
2290}
ff3187f6 2291static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2292{
65a22376 2293 unsigned long value;
ff3187f6 2294 if (pkt->length - pkt->savedpos < 1)
32874aea 2295 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2296 value = pkt->body[pkt->savedpos] != 0;
2297 pkt->savedpos++;
65a22376 2298 return value;
2299}
ff3187f6 2300static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2301{
57356d63 2302 int len;
7cca0d81 2303 *p = NULL;
45068b27 2304 *length = 0;
ff3187f6 2305 if (pkt->length - pkt->savedpos < 4)
32874aea 2306 return;
ff3187f6 2307 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2308 if (len < 0)
2309 return;
2310 *length = len;
ff3187f6 2311 pkt->savedpos += 4;
2312 if (pkt->length - pkt->savedpos < *length)
32874aea 2313 return;
ff3187f6 2314 *p = (char *)(pkt->body + pkt->savedpos);
2315 pkt->savedpos += *length;
7cca0d81 2316}
ff3187f6 2317static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2318{
ff3187f6 2319 if (pkt->length - pkt->savedpos < length)
0016d70b 2320 return NULL;
ff3187f6 2321 pkt->savedpos += length;
2322 return pkt->body + (pkt->savedpos - length);
0016d70b 2323}
ff3187f6 2324static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2325 unsigned char **keystr)
2326{
2327 int j;
2328
ff3187f6 2329 j = makekey(pkt->body + pkt->savedpos,
2330 pkt->length - pkt->savedpos,
0016d70b 2331 key, keystr, 0);
2332
2333 if (j < 0)
2334 return FALSE;
2335
ff3187f6 2336 pkt->savedpos += j;
2337 assert(pkt->savedpos < pkt->length);
0016d70b 2338
2339 return TRUE;
2340}
ff3187f6 2341static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2342{
2343 int j;
2344 Bignum b;
2345
ff3187f6 2346 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2347 pkt->length - pkt->savedpos, &b);
0016d70b 2348
2349 if (j < 0)
2350 return NULL;
2351
ff3187f6 2352 pkt->savedpos += j;
0016d70b 2353 return b;
2354}
ff3187f6 2355static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2356{
7cca0d81 2357 char *p;
3709bfe9 2358 int length;
7cca0d81 2359 Bignum b;
2360
ff3187f6 2361 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2362 if (!p)
32874aea 2363 return NULL;
ff3187f6 2364 if (p[0] & 0x80)
32874aea 2365 return NULL;
d8baa528 2366 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2367 return b;
2368}
2369
7d503c31 2370/*
2e85c969 2371 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2372 * Expects to be shown the public key blob as well as the signature
2373 * blob. Normally works just like ssh2_pkt_addstring, but will
2374 * fiddle with the signature packet if necessary for
2375 * BUG_SSH2_RSA_PADDING.
2376 */
ff3187f6 2377static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2378 void *pkblob_v, int pkblob_len,
1dd353b5 2379 void *sigblob_v, int sigblob_len)
2380{
2381 unsigned char *pkblob = (unsigned char *)pkblob_v;
2382 unsigned char *sigblob = (unsigned char *)sigblob_v;
2383
2384 /* dmemdump(pkblob, pkblob_len); */
2385 /* dmemdump(sigblob, sigblob_len); */
2386
2387 /*
2388 * See if this is in fact an ssh-rsa signature and a buggy
2389 * server; otherwise we can just do this the easy way.
2390 */
51470298 2391 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2392 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2393 int pos, len, siglen;
2394
2395 /*
2396 * Find the byte length of the modulus.
2397 */
2398
2399 pos = 4+7; /* skip over "ssh-rsa" */
2400 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2401 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2402 pos += 4; /* find modulus itself */
2403 while (len > 0 && pkblob[pos] == 0)
2404 len--, pos++;
2405 /* debug(("modulus length is %d\n", len)); */
2406
2407 /*
2408 * Now find the signature integer.
2409 */
2410 pos = 4+7; /* skip over "ssh-rsa" */
2411 siglen = GET_32BIT(sigblob+pos);
2412 /* debug(("signature length is %d\n", siglen)); */
2413
2414 if (len != siglen) {
2415 unsigned char newlen[4];
ff3187f6 2416 ssh2_pkt_addstring_start(pkt);
2417 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2418 /* dmemdump(sigblob, pos); */
2419 pos += 4; /* point to start of actual sig */
2420 PUT_32BIT(newlen, len);
ff3187f6 2421 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2422 /* dmemdump(newlen, 4); */
2423 newlen[0] = 0;
2424 while (len-- > siglen) {
ff3187f6 2425 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2426 /* dmemdump(newlen, 1); */
2427 }
ff3187f6 2428 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2429 /* dmemdump(sigblob+pos, siglen); */
2430 return;
2431 }
2432
2433 /* Otherwise fall through and do it the easy way. */
2434 }
2435
ff3187f6 2436 ssh2_pkt_addstring_start(pkt);
2437 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2438}
2439
2440/*
7d503c31 2441 * Examine the remote side's version string and compare it against
2442 * a list of known buggy implementations.
2443 */
51470298 2444static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2445{
2446 char *imp; /* pointer to implementation part */
7d503c31 2447 imp = vstring;
2448 imp += strcspn(imp, "-");
bd358db1 2449 if (*imp) imp++;
7d503c31 2450 imp += strcspn(imp, "-");
bd358db1 2451 if (*imp) imp++;
7d503c31 2452
51470298 2453 ssh->remote_bugs = 0;
7d503c31 2454
bf982899 2455 /*
2456 * General notes on server version strings:
2457 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2458 * here -- in particular, we've heard of one that's perfectly happy
2459 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2460 * so we can't distinguish them.
2461 */
4a693cfc 2462 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2463 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2c9c6388 2464 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2465 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2466 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2467 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2468 /*
2469 * These versions don't support SSH1_MSG_IGNORE, so we have
2470 * to use a different defence against password length
2471 * sniffing.
2472 */
51470298 2473 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2474 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2475 }
2476
4a693cfc 2477 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2478 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
46ac09aa 2479 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2480 /*
2481 * These versions need a plain password sent; they can't
2482 * handle having a null and a random length of data after
2483 * the password.
2484 */
51470298 2485 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2486 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2487 }
2488
4a693cfc 2489 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2490 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2c9c6388 2491 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2492 /*
2493 * These versions apparently have no clue whatever about
2494 * RSA authentication and will panic and die if they see
2495 * an AUTH_RSA message.
2496 */
51470298 2497 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2498 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2499 }
2500
4a693cfc 2501 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2502 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
b9f387af 2503 !wc_match("* VShell", imp) &&
831301f6 2504 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2505 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2506 wc_match("2.1 *", imp)))) {
32874aea 2507 /*
2508 * These versions have the HMAC bug.
2509 */
51470298 2510 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2511 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2512 }
1dd353b5 2513
4a693cfc 2514 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2515 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
b9f387af 2516 !wc_match("* VShell", imp) &&
2856a1b9 2517 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2518 /*
2519 * These versions have the key-derivation bug (failing to
2520 * include the literal shared secret in the hashes that
2521 * generate the keys).
2522 */
51470298 2523 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2524 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2525 }
2526
4a693cfc 2527 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2528 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
831301f6 2529 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2530 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2531 /*
2e85c969 2532 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2533 */
51470298 2534 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2535 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2536 }
8e975795 2537
4a693cfc 2538 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2539 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
dda87a28 2540 wc_match("OpenSSH_2.[0-2]*", imp))) {
2541 /*
2e85c969 2542 * These versions have the SSH-2 session-ID bug in
dda87a28 2543 * public-key authentication.
2544 */
2545 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2546 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2547 }
f382c87d 2548
4a693cfc 2549 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2550 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
39b8712f 2551 (wc_match("DigiSSH_2.0", imp) ||
2552 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2553 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2554 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2555 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2556 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2557 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2558 /*
2e85c969 2559 * These versions have the SSH-2 rekey bug.
f382c87d 2560 */
2561 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2562 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2563 }
c9739dba 2564
4a693cfc 2565 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2566 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
5ca836f2 2567 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2568 wc_match("1.36 sshlib: GlobalScape", imp)))) {
c9739dba 2569 /*
2570 * This version ignores our makpkt and needs to be throttled.
2571 */
2572 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2573 logevent("We believe remote version ignores SSH-2 maximum packet size");
2574 }
cf6ddb95 2575
4a693cfc 2576 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
cf6ddb95 2577 /*
2578 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2579 * none detected automatically.
2580 */
2581 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2582 logevent("We believe remote version has SSH-2 ignore bug");
2583 }
2e0aae4f 2584
2585 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2586 /*
2587 * Servers that don't support our winadj request for one
2588 * reason or another. Currently, none detected automatically.
2589 */
2590 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2591 logevent("We believe remote version has winadj bug");
2592 }
7d503c31 2593}
2594
d38d6a1f 2595/*
2596 * The `software version' part of an SSH version string is required
2597 * to contain no spaces or minus signs.
2598 */
2599static void ssh_fix_verstring(char *str)
2600{
2601 /* Eat "SSH-<protoversion>-". */
2602 assert(*str == 'S'); str++;
2603 assert(*str == 'S'); str++;
2604 assert(*str == 'H'); str++;
2605 assert(*str == '-'); str++;
2606 while (*str && *str != '-') str++;
2607 assert(*str == '-'); str++;
2608
2609 /* Convert minus signs and spaces in the remaining string into
2610 * underscores. */
2611 while (*str) {
2612 if (*str == '-' || *str == ' ')
2613 *str = '_';
2614 str++;
2615 }
2616}
2617
1fcd0d98 2618/*
2619 * Send an appropriate SSH version string.
2620 */
2621static void ssh_send_verstring(Ssh ssh, char *svers)
2622{
2623 char *verstring;
2624
2625 if (ssh->version == 2) {
2626 /*
2627 * Construct a v2 version string.
2628 */
2629 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2630 } else {
2631 /*
2632 * Construct a v1 version string.
2633 */
2634 verstring = dupprintf("SSH-%s-%s\012",
2635 (ssh_versioncmp(svers, "1.5") <= 0 ?
2636 svers : "1.5"),
2637 sshver);
2638 }
2639
2640 ssh_fix_verstring(verstring);
2641
2642 if (ssh->version == 2) {
2643 size_t len;
2644 /*
2645 * Record our version string.
2646 */
2647 len = strcspn(verstring, "\015\012");
2648 ssh->v_c = snewn(len + 1, char);
2649 memcpy(ssh->v_c, verstring, len);
2650 ssh->v_c[len] = 0;
2651 }
2652
2653 logeventf(ssh, "We claim version: %.*s",
2654 strcspn(verstring, "\015\012"), verstring);
2655 s_write(ssh, verstring, strlen(verstring));
2656 sfree(verstring);
2657}
2658
51470298 2659static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2660{
51470298 2661 struct do_ssh_init_state {
2662 int vslen;
2663 char version[10];
2664 char *vstring;
2665 int vstrsize;
2666 int i;
2667 int proto1, proto2;
2668 };
2669 crState(do_ssh_init_state);
374330e2 2670
51470298 2671 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2672
8c1835c0 2673 /* Search for a line beginning with the string "SSH-" in the input. */
2674 for (;;) {
2675 if (c != 'S') goto no;
2676 crReturn(1);
2677 if (c != 'S') goto no;
2678 crReturn(1);
2679 if (c != 'H') goto no;
2680 crReturn(1);
2681 if (c != '-') goto no;
2682 break;
2683 no:
2684 while (c != '\012')
2685 crReturn(1);
2686 crReturn(1);
374330e2 2687 }
8df7a775 2688
51470298 2689 s->vstrsize = 16;
3d88e64d 2690 s->vstring = snewn(s->vstrsize, char);
51470298 2691 strcpy(s->vstring, "SSH-");
2692 s->vslen = 4;
2693 s->i = 0;
374330e2 2694 while (1) {
8df7a775 2695 crReturn(1); /* get another char */
51470298 2696 if (s->vslen >= s->vstrsize - 1) {
2697 s->vstrsize += 16;
3d88e64d 2698 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2699 }
51470298 2700 s->vstring[s->vslen++] = c;
2701 if (s->i >= 0) {
374330e2 2702 if (c == '-') {
51470298 2703 s->version[s->i] = '\0';
2704 s->i = -1;
2705 } else if (s->i < sizeof(s->version) - 1)
2706 s->version[s->i++] = c;
c4ffc4d0 2707 } else if (c == '\012')
374330e2 2708 break;
2709 }
2710
51470298 2711 ssh->agentfwd_enabled = FALSE;
2712 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2713
51470298 2714 s->vstring[s->vslen] = 0;
a7d4653a 2715 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2716 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2717 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2718
adf799dd 2719 /*
38d228a2 2720 * Decide which SSH protocol version to support.
adf799dd 2721 */
38d228a2 2722
2723 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2724 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2725 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2726 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2727
4a693cfc 2728 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
6b5cf8b4 2729 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2730 crStop(0);
38d228a2 2731 }
4a693cfc 2732 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
6b5cf8b4 2733 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2734 crStop(0);
38d228a2 2735 }
2736
4a693cfc 2737 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
1fcd0d98 2738 ssh->version = 2;
2739 else
2740 ssh->version = 1;
d38d6a1f 2741
2742 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2743
1fcd0d98 2744 /* Send the version string, if we haven't already */
4a693cfc 2745 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
1fcd0d98 2746 ssh_send_verstring(ssh, s->version);
2747
2748 if (ssh->version == 2) {
2749 size_t len;
2750 /*
2751 * Record their version string.
2752 */
2753 len = strcspn(s->vstring, "\015\012");
2754 ssh->v_s = snewn(len + 1, char);
2755 memcpy(ssh->v_s, s->vstring, len);
2756 ssh->v_s[len] = 0;
2757
2758 /*
2759 * Initialise SSH-2 protocol.
2760 */
2761 ssh->protocol = ssh2_protocol;
2762 ssh2_protocol_setup(ssh);
2763 ssh->s_rdpkt = ssh2_rdpkt;
2764 } else {
2765 /*
2766 * Initialise SSH-1 protocol.
2767 */
2768 ssh->protocol = ssh1_protocol;
2769 ssh1_protocol_setup(ssh);
2770 ssh->s_rdpkt = ssh1_rdpkt;
2771 }
2772 if (ssh->version == 2)
2773 do_ssh2_transport(ssh, NULL, -1, NULL);
2774
125105d1 2775 update_specials_menu(ssh->frontend);
51470298 2776 ssh->state = SSH_STATE_BEFORE_SIZE;
4a693cfc 2777 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
8df7a775 2778
51470298 2779 sfree(s->vstring);
50526e47 2780
8df7a775 2781 crFinish(0);
2782}
2783
3d9449a1 2784static void ssh_process_incoming_data(Ssh ssh,
2785 unsigned char **data, int *datalen)
2786{
bf8a49a1 2787 struct Packet *pktin;
2788
2789 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2790 if (pktin) {
2791 ssh->protocol(ssh, NULL, 0, pktin);
2792 ssh_free_packet(pktin);
2793 }
2794}
2795
2796static void ssh_queue_incoming_data(Ssh ssh,
2797 unsigned char **data, int *datalen)
2798{
2799 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2800 *data += *datalen;
2801 *datalen = 0;
2802}
2803
2804static void ssh_process_queued_incoming_data(Ssh ssh)
2805{
2806 void *vdata;
2807 unsigned char *data;
2808 int len, origlen;
2809
2810 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2811 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2812 data = vdata;
2813 origlen = len;
2814
2815 while (!ssh->frozen && len > 0)
2816 ssh_process_incoming_data(ssh, &data, &len);
2817
2818 if (origlen > len)
2819 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2820 }
2821}
2822
2823static void ssh_set_frozen(Ssh ssh, int frozen)
2824{
a5a6f839 2825 if (ssh->s)
2826 sk_set_frozen(ssh->s, frozen);
3d9449a1 2827 ssh->frozen = frozen;
2828}
2829
51470298 2830static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2831{
bf8a49a1 2832 /* Log raw data, if we're in that mode. */
ff05dfef 2833 if (ssh->logctx)
2834 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
0d13bfcd 2835 0, NULL, NULL);
bf8a49a1 2836
51470298 2837 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2838
2839 /*
2840 * To begin with, feed the characters one by one to the
2841 * protocol initialisation / selection function do_ssh_init().
2842 * When that returns 0, we're done with the initial greeting
2843 * exchange and can move on to packet discipline.
2844 */
2845 while (1) {
51470298 2846 int ret; /* need not be kept across crReturn */
8df7a775 2847 if (datalen == 0)
2848 crReturnV; /* more data please */
51470298 2849 ret = do_ssh_init(ssh, *data);
32874aea 2850 data++;
2851 datalen--;
8df7a775 2852 if (ret == 0)
2853 break;
2854 }
2855
2856 /*
2857 * We emerge from that loop when the initial negotiation is
2858 * over and we have selected an s_rdpkt function. Now pass
2859 * everything to s_rdpkt, and then pass the resulting packets
2860 * to the proper protocol handler.
2861 */
3d9449a1 2862
8df7a775 2863 while (1) {
e375106c 2864 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2865 if (ssh->frozen) {
3d9449a1 2866 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2867 /* This uses up all data and cannot cause anything interesting
2868 * to happen; indeed, for anything to happen at all, we must
2869 * return, so break out. */
2870 break;
2871 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2872 /* This uses up some or all data, and may freeze the
2873 * session. */
2874 ssh_process_queued_incoming_data(ssh);
2875 } else {
2876 /* This uses up some or all data, and may freeze the
2877 * session. */
2878 ssh_process_incoming_data(ssh, &data, &datalen);
2879 }
2880 /* FIXME this is probably EBW. */
ff3187f6 2881 if (ssh->state == SSH_STATE_CLOSED)
2882 return;
8df7a775 2883 }
e375106c 2884 /* We're out of data. Go and get some more. */
8df7a775 2885 crReturnV;
2886 }
2887 crFinishV;
2888}
2889
ac934965 2890static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2891{
80ffa58b 2892 int ret = 0;
36f94d1f 2893 struct ssh_channel *c;
2894
51470298 2895 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2896 expire_timer_context(ssh);
51470298 2897 if (ssh->s) {
2898 sk_close(ssh->s);
2899 ssh->s = NULL;
ac934965 2900 if (notify_exit)
2901 notify_remote_exit(ssh->frontend);
2902 else
2903 ret = 1;
f3ab576e 2904 }
36f94d1f 2905 /*
80ffa58b 2906 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2907 * through this connection.
2908 */
74a98066 2909 if (ssh->channels) {
80ffa58b 2910 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2911 switch (c->type) {
2912 case CHAN_X11:
2913 x11_close(c->u.x11.s);
2914 break;
2915 case CHAN_SOCKDATA:
409eca86 2916 case CHAN_SOCKDATA_DORMANT:
74a98066 2917 pfd_close(c->u.pfd.s);
2918 break;
2919 }
80ffa58b 2920 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2921 if (ssh->version == 2)
2922 bufchain_clear(&c->v.v2.outbuffer);
2923 sfree(c);
36f94d1f 2924 }
36f94d1f 2925 }
f8c9f9df 2926 /*
2927 * Go through port-forwardings, and close any associated
2928 * listening sockets.
2929 */
2930 if (ssh->portfwds) {
2931 struct ssh_portfwd *pf;
2932 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2933 /* Dispose of any listening socket. */
2934 if (pf->local)
2935 pfd_terminate(pf->local);
2936 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2937 free_portfwd(pf);
2938 }
b72bdf11 2939 freetree234(ssh->portfwds);
2940 ssh->portfwds = NULL;
f8c9f9df 2941 }
ac934965 2942
2943 return ret;
36f94d1f 2944}
2945
7555d6a5 2946static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2947 const char *error_msg, int error_code)
2948{
2949 Ssh ssh = (Ssh) plug;
2950 char addrbuf[256], *msg;
2951
2952 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2953
2954 if (type == 0)
2955 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2956 else
2957 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2958
2959 logevent(msg);
fb983202 2960 sfree(msg);
7555d6a5 2961}
2962
cbe2d68f 2963static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2964 int calling_back)
2965{
2966 Ssh ssh = (Ssh) plug;
ac934965 2967 int need_notify = ssh_do_close(ssh, FALSE);
2968
9e296bfa 2969 if (!error_msg) {
2970 if (!ssh->close_expected)
2971 error_msg = "Server unexpectedly closed network connection";
2972 else
2973 error_msg = "Server closed network connection";
ac934965 2974 }
2975
d051d1b4 2976 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2977 ssh->exitcode = 0;
2978
2425184b 2979 if (need_notify)
2980 notify_remote_exit(ssh->frontend);
2981
9e296bfa 2982 if (error_msg)
247308b5 2983 logevent(error_msg);
9e296bfa 2984 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2985 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2986 return 0;
2987}
2988
32874aea 2989static int ssh_receive(Plug plug, int urgent, char *data, int len)
2990{
51470298 2991 Ssh ssh = (Ssh) plug;
d8baa528 2992 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2993 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2994 ssh_do_close(ssh, TRUE);
32874aea 2995 return 0;
3257deae 2996 }
fef97f43 2997 return 1;
374330e2 2998}
2999
5471d09a 3000static void ssh_sent(Plug plug, int bufsize)
3001{
51470298 3002 Ssh ssh = (Ssh) plug;
5471d09a 3003 /*
3004 * If the send backlog on the SSH socket itself clears, we
3005 * should unthrottle the whole world if it was throttled.
3006 */
3007 if (bufsize < SSH_MAX_BACKLOG)
51470298 3008 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 3009}
3010
fb09bf1c 3011/*
8df7a775 3012 * Connect to specified host and port.
3013 * Returns an error message, or NULL on success.
6e1ebb76 3014 * Also places the canonical host name into `realhost'. It must be
3015 * freed by the caller.
8df7a775 3016 */
cbe2d68f 3017static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 3018 char **realhost, int nodelay, int keepalive)
8df7a775 3019{
51470298 3020 static const struct plug_function_table fn_table = {
7555d6a5 3021 ssh_log,
7e78000d 3022 ssh_closing,
5471d09a 3023 ssh_receive,
3024 ssh_sent,
3025 NULL
51470298 3026 };
7e78000d 3027
8df7a775 3028 SockAddr addr;
cbe2d68f 3029 const char *err;
4a693cfc 3030 char *loghost;
3031 int addressfamily, sshprot;
3032
3033 loghost = conf_get_str(ssh->conf, CONF_loghost);
3034 if (*loghost) {
881da168 3035 char *colon;
8df7a775 3036
4a693cfc 3037 ssh->savedhost = dupstr(loghost);
881da168 3038 ssh->savedport = 22; /* default ssh port */
3039
3040 /*
3041 * A colon suffix on savedhost also lets us affect
3042 * savedport.
3043 *
3044 * (FIXME: do something about IPv6 address literals here.)
3045 */
3046 colon = strrchr(ssh->savedhost, ':');
3047 if (colon) {
3048 *colon++ = '\0';
3049 if (*colon)
3050 ssh->savedport = atoi(colon);
3051 }
3052 } else {
3053 ssh->savedhost = dupstr(host);
3054 if (port < 0)
3055 port = 22; /* default ssh port */
3056 ssh->savedport = port;
3057 }
8df7a775 3058
3059 /*
3060 * Try to find host.
3061 */
4a693cfc 3062 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
05581745 3063 logeventf(ssh, "Looking up host \"%s\"%s", host,
4a693cfc 3064 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3065 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3066 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
170c1e6e 3067 if ((err = sk_addr_error(addr)) != NULL) {
3068 sk_addr_free(addr);
8df7a775 3069 return err;
170c1e6e 3070 }
42af6a67 3071 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
8df7a775 3072
8df7a775 3073 /*
3074 * Open socket.
3075 */
51470298 3076 ssh->fn = &fn_table;
e8fa8f62 3077 ssh->s = new_connection(addr, *realhost, port,
4a693cfc 3078 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
70e5d0fd 3079 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 3080 ssh->s = NULL;
39934deb 3081 notify_remote_exit(ssh->frontend);
8df7a775 3082 return err;
67c4ba2e 3083 }
8df7a775 3084
ff05dfef 3085 /*
3086 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3087 * send the version string too.
3088 */
4a693cfc 3089 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3090 if (sshprot == 0)
ff05dfef 3091 ssh->version = 1;
4a693cfc 3092 if (sshprot == 3) {
ff05dfef 3093 ssh->version = 2;
3094 ssh_send_verstring(ssh, NULL);
3095 }
3096
881da168 3097 /*
3098 * loghost, if configured, overrides realhost.
3099 */
4a693cfc 3100 if (*loghost) {
881da168 3101 sfree(*realhost);
4a693cfc 3102 *realhost = dupstr(loghost);
881da168 3103 }
3104
8df7a775 3105 return NULL;
3106}
3107
3108/*
5471d09a 3109 * Throttle or unthrottle the SSH connection.
3110 */
ff68564b 3111static void ssh_throttle_conn(Ssh ssh, int adjust)
5471d09a 3112{
ff68564b 3113 int old_count = ssh->conn_throttle_count;
3114 ssh->conn_throttle_count += adjust;
3115 assert(ssh->conn_throttle_count >= 0);
3116 if (ssh->conn_throttle_count && !old_count) {
3d9449a1 3117 ssh_set_frozen(ssh, 1);
ff68564b 3118 } else if (!ssh->conn_throttle_count && old_count) {
3d9449a1 3119 ssh_set_frozen(ssh, 0);
5471d09a 3120 }
3121}
3122
3123/*
3124 * Throttle or unthrottle _all_ local data streams (for when sends
3125 * on the SSH connection itself back up).
3126 */
51470298 3127static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 3128{
3129 int i;
3130 struct ssh_channel *c;
3131
51470298 3132 if (enable == ssh->throttled_all)
5471d09a 3133 return;
51470298 3134 ssh->throttled_all = enable;
3135 ssh->overall_bufsize = bufsize;
3136 if (!ssh->channels)
5471d09a 3137 return;
51470298 3138 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 3139 switch (c->type) {
3140 case CHAN_MAINSESSION:
3141 /*
3142 * This is treated separately, outside the switch.
3143 */
3144 break;
3145 case CHAN_X11:
3146 x11_override_throttle(c->u.x11.s, enable);
3147 break;
3148 case CHAN_AGENT:
3149 /* Agent channels require no buffer management. */
3150 break;
3151 case CHAN_SOCKDATA:
36f94d1f 3152 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 3153 break;
3154 }
3155 }
3156}
3157
f11d78f2 3158static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 3159{
3160 Ssh ssh = (Ssh) sshv;
3161
3162 ssh->agent_response = reply;
3163 ssh->agent_response_len = replylen;
3164
3165 if (ssh->version == 1)
ff3187f6 3166 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 3167 else
ff3187f6 3168 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 3169}
3170
3d9449a1 3171static void ssh_dialog_callback(void *sshv, int ret)
3172{
3173 Ssh ssh = (Ssh) sshv;
3174
3175 ssh->user_response = ret;
3176
3177 if (ssh->version == 1)
3178 do_ssh1_login(ssh, NULL, -1, NULL);
3179 else
3180 do_ssh2_transport(ssh, NULL, -1, NULL);
3181
3182 /*
3183 * This may have unfrozen the SSH connection, so do a
3184 * queued-data run.
3185 */
3186 ssh_process_queued_incoming_data(ssh);
3187}
3188
f11d78f2 3189static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 3190{
3191 struct ssh_channel *c = (struct ssh_channel *)cv;
3192 Ssh ssh = c->ssh;
3193 void *sentreply = reply;
3194
3195 if (!sentreply) {
3196 /* Fake SSH_AGENT_FAILURE. */
3197 sentreply = "\0\0\0\1\5";
3198 replylen = 5;
3199 }
3200 if (ssh->version == 2) {
3201 ssh2_add_channel_data(c, sentreply, replylen);
3202 ssh2_try_send(c);
3203 } else {
3204 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3205 PKT_INT, c->remoteid,
3206 PKT_INT, replylen,
a2724fba 3207 PKTT_DATA,
839f10db 3208 PKT_DATA, sentreply, replylen,
9a10ecf4 3209 PKTT_OTHER,
839f10db 3210 PKT_END);
3211 }
3212 if (reply)
3213 sfree(reply);
3214}
3215
0405e71f 3216/*
9e296bfa 3217 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3218 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3219 * => log `wire_reason'.
3220 */
3221static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3222 int code, int clean_exit)
3223{
3224 char *error;
3225 if (!client_reason)
3226 client_reason = wire_reason;
3227 if (client_reason)
3228 error = dupprintf("Disconnected: %s", client_reason);
3229 else
3230 error = dupstr("Disconnected");
3231 if (wire_reason) {
3232 if (ssh->version == 1) {
3233 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3234 PKT_END);
3235 } else if (ssh->version == 2) {
3236 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3237 ssh2_pkt_adduint32(pktout, code);
3238 ssh2_pkt_addstring(pktout, wire_reason);
3239 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3240 ssh2_pkt_send_noqueue(ssh, pktout);
3241 }
3242 }
3243 ssh->close_expected = TRUE;
3244 ssh->clean_exit = clean_exit;
3245 ssh_closing((Plug)ssh, error, 0, 0);
3246 sfree(error);
3247}
3248
3249/*
fb09bf1c 3250 * Handle the key exchange and user authentication phases.
3251 */
ff3187f6 3252static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3253 struct Packet *pktin)
fb09bf1c 3254{
0016d70b 3255 int i, j, ret;
3256 unsigned char cookie[8], *ptr;
374330e2 3257 struct RSAKey servkey, hostkey;
3258 struct MD5Context md5c;
51470298 3259 struct do_ssh1_login_state {
3260 int len;
3261 unsigned char *rsabuf, *keystr1, *keystr2;
3262 unsigned long supported_ciphers_mask, supported_auths_mask;
3263 int tried_publickey, tried_agent;
3264 int tis_auth_refused, ccard_auth_refused;
3265 unsigned char session_id[16];
3266 int cipher_type;
51470298 3267 void *publickey_blob;
3268 int publickey_bloblen;
edd0cb8a 3269 char *publickey_comment;
3270 int publickey_encrypted;
3271 prompts_t *cur_prompt;
51470298 3272 char c;
3273 int pwpkt_type;
3274 unsigned char request[5], *response, *p;
3275 int responselen;
3276 int keyi, nkeys;
3277 int authed;
3278 struct RSAKey key;
3279 Bignum challenge;
3280 char *commentp;
3281 int commentlen;
3d9449a1 3282 int dlgret;
4a693cfc 3283 Filename *keyfile;
51470298 3284 };
3285 crState(do_ssh1_login_state);
3286
3287 crBegin(ssh->do_ssh1_login_crstate);
374330e2 3288
ff3187f6 3289 if (!pktin)
3290 crWaitUntil(pktin);
374330e2 3291
ff3187f6 3292 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3293 bombout(("Public key packet not received"));
7ffdbc1a 3294 crStop(0);
8d5de777 3295 }
374330e2 3296
c5e9c988 3297 logevent("Received public keys");
374330e2 3298
ff3187f6 3299 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3300 if (!ptr) {
2e85c969 3301 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3302 crStop(0);
3303 }
3304 memcpy(cookie, ptr, 8);
374330e2 3305
ff3187f6 3306 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3307 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 3308 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3309 crStop(0);
3310 }
374330e2 3311
c5e9c988 3312 /*
1c2a93c4 3313 * Log the host key fingerprint.
c5e9c988 3314 */
c5e9c988 3315 {
3316 char logmsg[80];
1c2a93c4 3317 logevent("Host key fingerprint is:");
c5e9c988 3318 strcpy(logmsg, " ");
32874aea 3319 hostkey.comment = NULL;
3320 rsa_fingerprint(logmsg + strlen(logmsg),
3321 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 3322 logevent(logmsg);
3323 }
3324
ff3187f6 3325 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3326 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3327 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3328 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3329 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3330
51470298 3331 ssh->v1_local_protoflags =
3332 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3333 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3334
c5e9c988 3335 MD5Init(&md5c);
51470298 3336 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3337 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 3338 MD5Update(&md5c, cookie, 8);
51470298 3339 MD5Final(s->session_id, &md5c);
374330e2 3340
32874aea 3341 for (i = 0; i < 32; i++)
51470298 3342 ssh->session_key[i] = random_byte();
374330e2 3343
0016d70b 3344 /*
3345 * Verify that the `bits' and `bytes' parameters match.
3346 */
3347 if (hostkey.bits > hostkey.bytes * 8 ||
3348 servkey.bits > servkey.bytes * 8) {
2e85c969 3349 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3350 crStop(0);
3351 }
3352
51470298 3353 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 3354
3d88e64d 3355 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3356
89ee5268 3357 /*
3358 * Verify the host key.
3359 */
3360 {
32874aea 3361 /*
3362 * First format the key into a string.
3363 */
3364 int len = rsastr_len(&hostkey);
3365 char fingerprint[100];
3d88e64d 3366 char *keystr = snewn(len, char);
32874aea 3367 rsastr_fmt(keystr, &hostkey);
3368 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 3369
3370 ssh_set_frozen(ssh, 1);
3371 s->dlgret = verify_ssh_host_key(ssh->frontend,
3372 ssh->savedhost, ssh->savedport,
3373 "rsa", keystr, fingerprint,
3374 ssh_dialog_callback, ssh);
32874aea 3375 sfree(keystr);
3d9449a1 3376 if (s->dlgret < 0) {
3377 do {
3378 crReturn(0);
3379 if (pktin) {
3380 bombout(("Unexpected data from server while waiting"
3381 " for user host key response"));
3382 crStop(0);
3383 }
3384 } while (pktin || inlen > 0);
3385 s->dlgret = ssh->user_response;
3386 }
3387 ssh_set_frozen(ssh, 0);
3388
3389 if (s->dlgret == 0) {
9e296bfa 3390 ssh_disconnect(ssh, "User aborted at host key verification",
3391 NULL, 0, TRUE);
2b3f6c19 3392 crStop(0);
3d9449a1 3393 }
32874aea 3394 }
3395
3396 for (i = 0; i < 32; i++) {
51470298 3397 s->rsabuf[i] = ssh->session_key[i];
374330e2 3398 if (i < 16)
51470298 3399 s->rsabuf[i] ^= s->session_id[i];
374330e2 3400 }
3401
3402 if (hostkey.bytes > servkey.bytes) {
0016d70b 3403 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3404 if (ret)
3405 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 3406 } else {
0016d70b 3407 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3408 if (ret)
3409 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3410 }
3411 if (!ret) {
2e85c969 3412 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3413 crStop(0);
374330e2 3414 }
3415
c5e9c988 3416 logevent("Encrypted session key");
3417
ca20bfcf 3418 {
3419 int cipher_chosen = 0, warn = 0;
3420 char *cipher_string = NULL;
51470298 3421 int i;
ca20bfcf 3422 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4a693cfc 3423 int next_cipher = conf_get_int_int(ssh->conf,
3424 CONF_ssh_cipherlist, i);
ca20bfcf 3425 if (next_cipher == CIPHER_WARN) {
3426 /* If/when we choose a cipher, warn about it */
3427 warn = 1;
3428 } else if (next_cipher == CIPHER_AES) {
3429 /* XXX Probably don't need to mention this. */
2e85c969 3430 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3431 } else {
3432 switch (next_cipher) {
51470298 3433 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3434 cipher_string = "3DES"; break;
51470298 3435 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3436 cipher_string = "Blowfish"; break;
51470298 3437 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3438 cipher_string = "single-DES"; break;
3439 }
51470298 3440 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3441 cipher_chosen = 1;
3442 }
3443 }
3444 if (!cipher_chosen) {
51470298 3445 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3446 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3447 "supporting 3DES encryption"));
3448 else
3449 /* shouldn't happen */
6b5cf8b4 3450 bombout(("No supported ciphers found"));
7ffdbc1a 3451 crStop(0);
a99a05c0 3452 }
ca20bfcf 3453
3454 /* Warn about chosen cipher if necessary. */
bb348ab1 3455 if (warn) {
3d9449a1 3456 ssh_set_frozen(ssh, 1);
3457 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3458 ssh_dialog_callback, ssh);
3459 if (s->dlgret < 0) {
3460 do {
3461 crReturn(0);
3462 if (pktin) {
3463 bombout(("Unexpected data from server while waiting"
3464 " for user response"));
3465 crStop(0);
3466 }
3467 } while (pktin || inlen > 0);
3468 s->dlgret = ssh->user_response;
3469 }
3470 ssh_set_frozen(ssh, 0);
3471 if (s->dlgret == 0) {
9e296bfa 3472 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3473 0, TRUE);
96ccde8b 3474 crStop(0);
3d9449a1 3475 }
bb348ab1 3476 }
bea1ef5f 3477 }
ca20bfcf 3478
51470298 3479 switch (s->cipher_type) {
32874aea 3480 case SSH_CIPHER_3DES:
3481 logevent("Using 3DES encryption");
3482 break;
3483 case SSH_CIPHER_DES:
3484 logevent("Using single-DES encryption");
3485 break;
3486 case SSH_CIPHER_BLOWFISH:
3487 logevent("Using Blowfish encryption");
3488 break;
c5e9c988 3489 }
bea1ef5f 3490
51470298 3491 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3492 PKT_CHAR, s->cipher_type,
32874aea 3493 PKT_DATA, cookie, 8,
51470298 3494 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3495 PKT_DATA, s->rsabuf, s->len,
3496 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3497
c5e9c988 3498 logevent("Trying to enable encryption...");
374330e2 3499
51470298 3500 sfree(s->rsabuf);
374330e2 3501
51470298 3502 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3503 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3504 &ssh_3des);
371e569c 3505 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3506 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3507 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3508
0183b242 3509 ssh->crcda_ctx = crcda_make_context();
3510 logevent("Installing CRC compensation attack detector");
3511
679539d7 3512 if (servkey.modulus) {
3513 sfree(servkey.modulus);
3514 servkey.modulus = NULL;
3515 }
3516 if (servkey.exponent) {
3517 sfree(servkey.exponent);
3518 servkey.exponent = NULL;
3519 }
3520 if (hostkey.modulus) {
3521 sfree(hostkey.modulus);
3522 hostkey.modulus = NULL;
3523 }
3524 if (hostkey.exponent) {
3525 sfree(hostkey.exponent);
3526 hostkey.exponent = NULL;
3527 }
ff3187f6 3528 crWaitUntil(pktin);
374330e2 3529
ff3187f6 3530 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3531 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3532 crStop(0);
8d5de777 3533 }
374330e2 3534
c5e9c988 3535 logevent("Successfully started encryption");
3536
edd0cb8a 3537 fflush(stdout); /* FIXME eh? */
374330e2 3538 {
4a693cfc 3539 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 3540 int ret; /* need not be kept over crReturn */
3541 s->cur_prompt = new_prompts(ssh->frontend);
3542 s->cur_prompt->to_server = TRUE;
3543 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 3544 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 3545 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3546 while (ret < 0) {
51470298 3547 ssh->send_ok = 1;
edd0cb8a 3548 crWaitUntil(!pktin);
3549 ret = get_userpass_input(s->cur_prompt, in, inlen);
3550 ssh->send_ok = 0;
3551 }
3552 if (!ret) {
3553 /*
3554 * Failed to get a username. Terminate.
3555 */
3556 free_prompts(s->cur_prompt);
3557 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3558 crStop(0);
32874aea 3559 }
4a693cfc 3560 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 3561 free_prompts(s->cur_prompt);
374330e2 3562 }
fb09bf1c 3563
4a693cfc 3564 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
c5e9c988 3565 {
4a693cfc 3566 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
c5e9c988 3567 logevent(userlog);
32874aea 3568 if (flags & FLAG_INTERACTIVE &&
3569 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3570 c_write_str(ssh, userlog);
edd0cb8a 3571 c_write_str(ssh, "\r\n");
3c8e959b 3572 }
edd0cb8a 3573 sfree(userlog);
c5e9c988 3574 }
374330e2 3575 }
3576
ff3187f6 3577 crWaitUntil(pktin);
374330e2 3578
d5b2c841 3579 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3580 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3581 s->tried_publickey = s->tried_agent = 1;
0df73905 3582 } else {
51470298 3583 s->tried_publickey = s->tried_agent = 0;
0df73905 3584 }
51470298 3585 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3586 /*
3587 * Load the public half of any configured keyfile for later use.
3588 */
4a693cfc 3589 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 3590 if (!filename_is_null(s->keyfile)) {
edd0cb8a 3591 int keytype;
3592 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 3593 filename_to_str(s->keyfile));
3594 keytype = key_type(s->keyfile);
edd0cb8a 3595 if (keytype == SSH_KEYTYPE_SSH1) {
3596 const char *error;
4a693cfc 3597 if (rsakey_pubblob(s->keyfile,
edd0cb8a 3598 &s->publickey_blob, &s->publickey_bloblen,
3599 &s->publickey_comment, &error)) {
4a693cfc 3600 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
edd0cb8a 3601 NULL);
3602 } else {
3603 char *msgbuf;
3604 logeventf(ssh, "Unable to load private key (%s)", error);
3605 msgbuf = dupprintf("Unable to load private key file "
3606 "\"%.150s\" (%s)\r\n",
4a693cfc 3607 filename_to_str(s->keyfile),
edd0cb8a 3608 error);
3609 c_write_str(ssh, msgbuf);
3610 sfree(msgbuf);
3611 s->publickey_blob = NULL;
3612 }
3613 } else {
3614 char *msgbuf;
3615 logeventf(ssh, "Unable to use this key file (%s)",
3616 key_type_to_str(keytype));
3617 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3618 " (%s)\r\n",
4a693cfc 3619 filename_to_str(s->keyfile),
edd0cb8a 3620 key_type_to_str(keytype));
3621 c_write_str(ssh, msgbuf);
3622 sfree(msgbuf);
51470298 3623 s->publickey_blob = NULL;
edd0cb8a 3624 }
396778f1 3625 } else
51470298 3626 s->publickey_blob = NULL;
7cca0d81 3627
ff3187f6 3628 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3629 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3630
4a693cfc 3631 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
32874aea 3632 /*
3633 * Attempt RSA authentication using Pageant.
3634 */
32874aea 3635 void *r;
3636
51470298 3637 s->authed = FALSE;
3638 s->tried_agent = 1;
32874aea 3639 logevent("Pageant is running. Requesting keys.");
3640
3641 /* Request the keys held by the agent. */
51470298 3642 PUT_32BIT(s->request, 1);
3643 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3644 if (!agent_query(s->request, 5, &r, &s->responselen,
3645 ssh_agent_callback, ssh)) {
3646 do {
3647 crReturn(0);
ff3187f6 3648 if (pktin) {
839f10db 3649 bombout(("Unexpected data from server while waiting"
3650 " for agent response"));
3651 crStop(0);
3652 }
ff3187f6 3653 } while (pktin || inlen > 0);
839f10db 3654 r = ssh->agent_response;
3655 s->responselen = ssh->agent_response_len;
3656 }
51470298 3657 s->response = (unsigned char *) r;
3658 if (s->response && s->responselen >= 5 &&
3659 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3660 s->p = s->response + 5;
3661 s->nkeys = GET_32BIT(s->p);
3662 s->p += 4;
2e85c969 3663 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3664 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3665 unsigned char *pkblob = s->p;
51470298 3666 s->p += 4;
0016d70b 3667 {
3668 int n, ok = FALSE;
3669 do { /* do while (0) to make breaking easy */
3670 n = ssh1_read_bignum
3671 (s->p, s->responselen-(s->p-s->response),
3672 &s->key.exponent);
3673 if (n < 0)
3674 break;
3675 s->p += n;
3676 n = ssh1_read_bignum
3677 (s->p, s->responselen-(s->p-s->response),
3678 &s->key.modulus);
3679 if (n < 0)
3680 break;
3681 s->p += n;
3682 if (s->responselen - (s->p-s->response) < 4)
3683 break;
3684 s->commentlen = GET_32BIT(s->p);
3685 s->p += 4;
3686 if (s->responselen - (s->p-s->response) <
3687 s->commentlen)
3688 break;
3689 s->commentp = (char *)s->p;
3690 s->p += s->commentlen;
3691 ok = TRUE;
3692 } while (0);
3693 if (!ok) {
3694 logevent("Pageant key list packet was truncated");
3695 break;
3696 }
3697 }
94cd7c3a 3698 if (s->publickey_blob) {
3699 if (!memcmp(pkblob, s->publickey_blob,
3700 s->publickey_bloblen)) {
3701 logeventf(ssh, "Pageant key #%d matches "
3702 "configured key file", s->keyi);
3703 s->tried_publickey = 1;
3704 } else
3705 /* Skip non-configured key */
3706 continue;
3707 }
3708 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3709 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3710 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3711 crWaitUntil(pktin);
3712 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3713 logevent("Key refused");
3714 continue;
3715 }
3716 logevent("Received RSA challenge");
ff3187f6 3717 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3718 bombout(("Server's RSA challenge was badly formatted"));
3719 crStop(0);
3720 }
3721
32874aea 3722 {
3723 char *agentreq, *q, *ret;
2d466ffd 3724 void *vret;
32874aea 3725 int len, retlen;
3726 len = 1 + 4; /* message type, bit count */
51470298 3727 len += ssh1_bignum_length(s->key.exponent);
3728 len += ssh1_bignum_length(s->key.modulus);
3729 len += ssh1_bignum_length(s->challenge);
32874aea 3730 len += 16; /* session id */
3731 len += 4; /* response format */
3d88e64d 3732 agentreq = snewn(4 + len, char);
32874aea 3733 PUT_32BIT(agentreq, len);
3734 q = agentreq + 4;
3735 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3736 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3737 q += 4;
51470298 3738 q += ssh1_write_bignum(q, s->key.exponent);
3739 q += ssh1_write_bignum(q, s->key.modulus);
3740 q += ssh1_write_bignum(q, s->challenge);
3741 memcpy(q, s->session_id, 16);
32874aea 3742 q += 16;
3743 PUT_32BIT(q, 1); /* response format */
839f10db 3744 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3745 ssh_agent_callback, ssh)) {
3746 sfree(agentreq);
3747 do {
3748 crReturn(0);
ff3187f6 3749 if (pktin) {
839f10db 3750 bombout(("Unexpected data from server"
3751 " while waiting for agent"
3752 " response"));
3753 crStop(0);
3754 }
ff3187f6 3755 } while (pktin || inlen > 0);
839f10db 3756 vret = ssh->agent_response;
3757 retlen = ssh->agent_response_len;
3758 } else
3759 sfree(agentreq);
2d466ffd 3760 ret = vret;
32874aea 3761 if (ret) {
3762 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3763 logevent("Sending Pageant's response");
51470298 3764 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3765 PKT_DATA, ret + 5, 16,
3766 PKT_END);
3767 sfree(ret);
ff3187f6 3768 crWaitUntil(pktin);
3769 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3770 logevent
3771 ("Pageant's response accepted");
3772 if (flags & FLAG_VERBOSE) {
51470298 3773 c_write_str(ssh, "Authenticated using"
3774 " RSA key \"");
3775 c_write(ssh, s->commentp,
3776 s->commentlen);
3777 c_write_str(ssh, "\" from agent\r\n");
32874aea 3778 }
51470298 3779 s->authed = TRUE;
32874aea 3780 } else
3781 logevent
3782 ("Pageant's response not accepted");
3783 } else {
3784 logevent
3785 ("Pageant failed to answer challenge");
3786 sfree(ret);
3787 }
3788 } else {
3789 logevent("No reply received from Pageant");
3790 }
3791 }
51470298 3792 freebn(s->key.exponent);
3793 freebn(s->key.modulus);
3794 freebn(s->challenge);
3795 if (s->authed)
32874aea 3796 break;
3797 }
29b1d0b3 3798 sfree(s->response);
94cd7c3a 3799 if (s->publickey_blob && !s->tried_publickey)
3800 logevent("Configured key file not in Pageant");
5ff99b8e 3801 } else {
3802 logevent("Failed to get reply from Pageant");
3803 }
51470298 3804 if (s->authed)
32874aea 3805 break;
3806 }
edd0cb8a 3807 if (s->publickey_blob && !s->tried_publickey) {
3808 /*
3809 * Try public key authentication with the specified
3810 * key file.
3811 */
3812 int got_passphrase; /* need not be kept over crReturn */
3813 if (flags & FLAG_VERBOSE)
3814 c_write_str(ssh, "Trying public key authentication.\r\n");
4a693cfc 3815 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
edd0cb8a 3816 logeventf(ssh, "Trying public key \"%s\"",
4a693cfc 3817 filename_to_str(s->keyfile));
edd0cb8a 3818 s->tried_publickey = 1;
3819 got_passphrase = FALSE;
3820 while (!got_passphrase) {
3821 /*
3822 * Get a passphrase, if necessary.
3823 */
3824 char *passphrase = NULL; /* only written after crReturn */
3825 const char *error;
3826 if (!s->publickey_encrypted) {
3827 if (flags & FLAG_VERBOSE)
3828 c_write_str(ssh, "No passphrase required.\r\n");
3829 passphrase = NULL;
3830 } else {
3831 int ret; /* need not be kept over crReturn */
3832 s->cur_prompt = new_prompts(ssh->frontend);
3833 s->cur_prompt->to_server = FALSE;
3834 s->cur_prompt->name = dupstr("SSH key passphrase");
3835 add_prompt(s->cur_prompt,
3836 dupprintf("Passphrase for key \"%.100s\": ",
b61f81bc 3837 s->publickey_comment), FALSE);
edd0cb8a 3838 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3839 while (ret < 0) {
3840 ssh->send_ok = 1;
3841 crWaitUntil(!pktin);
3842 ret = get_userpass_input(s->cur_prompt, in, inlen);
3843 ssh->send_ok = 0;
3844 }
3845 if (!ret) {
3846 /* Failed to get a passphrase. Terminate. */
3847 free_prompts(s->cur_prompt);
3848 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3849 0, TRUE);
3850 crStop(0);
3851 }
3852 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3853 free_prompts(s->cur_prompt);
3854 }
3855 /*
3856 * Try decrypting key with passphrase.
3857 */
4a693cfc 3858 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3859 ret = loadrsakey(s->keyfile, &s->key, passphrase,
edd0cb8a 3860 &error);
3861 if (passphrase) {
dfb88efd 3862 smemclr(passphrase, strlen(passphrase));
edd0cb8a 3863 sfree(passphrase);
3864 }
3865 if (ret == 1) {
3866 /* Correct passphrase. */
3867 got_passphrase = TRUE;
3868 } else if (ret == 0) {
3869 c_write_str(ssh, "Couldn't load private key from ");
4a693cfc 3870 c_write_str(ssh, filename_to_str(s->keyfile));
edd0cb8a 3871 c_write_str(ssh, " (");
3872 c_write_str(ssh, error);
3873 c_write_str(ssh, ").\r\n");
3874 got_passphrase = FALSE;
3875 break; /* go and try something else */
3876 } else if (ret == -1) {
3877 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3878 got_passphrase = FALSE;
3879 /* and try again */
43536490 3880 } else {
3881 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3882 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3883 }
3884 }
3885
3886 if (got_passphrase) {
3887
3888 /*
3889 * Send a public key attempt.
3890 */
3891 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3892 PKT_BIGNUM, s->key.modulus, PKT_END);
3893
3894 crWaitUntil(pktin);
3895 if (pktin->type == SSH1_SMSG_FAILURE) {
3896 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3897 continue; /* go and try something else */
edd0cb8a 3898 }
3899 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3900 bombout(("Bizarre response to offer of public key"));
3901 crStop(0);
3902 }
3903
3904 {
3905 int i;
3906 unsigned char buffer[32];
3907 Bignum challenge, response;
3908
3909 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3910 bombout(("Server's RSA challenge was badly formatted"));
3911 crStop(0);
3912 }
3913 response = rsadecrypt(challenge, &s->key);
3914 freebn(s->key.private_exponent);/* burn the evidence */
3915
3916 for (i = 0; i < 32; i++) {
3917 buffer[i] = bignum_byte(response, 31 - i);
3918 }
3919
3920 MD5Init(&md5c);
3921 MD5Update(&md5c, buffer, 32);
3922 MD5Update(&md5c, s->session_id, 16);
3923 MD5Final(buffer, &md5c);
3924
3925 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3926 PKT_DATA, buffer, 16, PKT_END);
3927
3928 freebn(challenge);
3929 freebn(response);
3930 }
3931
3932 crWaitUntil(pktin);
3933 if (pktin->type == SSH1_SMSG_FAILURE) {
3934 if (flags & FLAG_VERBOSE)
3935 c_write_str(ssh, "Failed to authenticate with"
3936 " our public key.\r\n");
7b575324 3937 continue; /* go and try something else */
edd0cb8a 3938 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3939 bombout(("Bizarre response to RSA authentication response"));
3940 crStop(0);
3941 }
3942
3943 break; /* we're through! */
3944 }
3945
3946 }
3947
3948 /*
3949 * Otherwise, try various forms of password-like authentication.
3950 */
3951 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3952
4a693cfc 3953 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3954 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3955 !s->tis_auth_refused) {
3956 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3957 logevent("Requested TIS authentication");
51470298 3958 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3959 crWaitUntil(pktin);
3960 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3961 logevent("TIS authentication declined");
3962 if (flags & FLAG_INTERACTIVE)
51470298 3963 c_write_str(ssh, "TIS authentication refused.\r\n");
3964 s->tis_auth_refused = 1;
614a20a0 3965 continue;
32874aea 3966 } else {
0016d70b 3967 char *challenge;
3968 int challengelen;
edd0cb8a 3969 char *instr_suf, *prompt;
0016d70b 3970
ff3187f6 3971 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3972 if (!challenge) {
3973 bombout(("TIS challenge packet was badly formed"));
3974 crStop(0);
3975 }
32874aea 3976 logevent("Received TIS challenge");
edd0cb8a 3977 s->cur_prompt->to_server = TRUE;
3978 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3979 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3980 if (memchr(challenge, '\n', challengelen)) {
3981 instr_suf = dupstr("");
3982 prompt = dupprintf("%.*s", challengelen, challenge);
3983 } else {
3984 instr_suf = dupprintf("%.*s", challengelen, challenge);
3985 prompt = dupstr("Response: ");
3986 }
3987 s->cur_prompt->instruction =
3988 dupprintf("Using TIS authentication.%s%s",
3989 (*instr_suf) ? "\n" : "",
3990 instr_suf);
3991 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 3992 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 3993 sfree(instr_suf);
32874aea 3994 }
3995 }
4a693cfc 3996 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3997 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3998 !s->ccard_auth_refused) {
3999 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 4000 logevent("Requested CryptoCard authentication");
51470298 4001 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 4002 crWaitUntil(pktin);
4003 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 4004 logevent("CryptoCard authentication declined");
51470298 4005 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4006 s->ccard_auth_refused = 1;
614a20a0 4007 continue;
32874aea 4008 } else {
0016d70b 4009 char *challenge;
4010 int challengelen;
edd0cb8a 4011 char *instr_suf, *prompt;
0016d70b 4012
ff3187f6 4013 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4014 if (!challenge) {
4015 bombout(("CryptoCard challenge packet was badly formed"));
4016 crStop(0);
4017 }
32874aea 4018 logevent("Received CryptoCard challenge");
edd0cb8a 4019 s->cur_prompt->to_server = TRUE;
4020 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4021 s->cur_prompt->name_reqd = FALSE;
4022 /* Prompt heuristic comes from OpenSSH */
4023 if (memchr(challenge, '\n', challengelen)) {
4024 instr_suf = dupstr("");
4025 prompt = dupprintf("%.*s", challengelen, challenge);
4026 } else {
4027 instr_suf = dupprintf("%.*s", challengelen, challenge);
4028 prompt = dupstr("Response: ");
4029 }
4030 s->cur_prompt->instruction =
4031 dupprintf("Using CryptoCard authentication.%s%s",
4032 (*instr_suf) ? "\n" : "",
4033 instr_suf);
4034 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4035 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4036 sfree(instr_suf);
32874aea 4037 }
4038 }
51470298 4039 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 4040 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4041 bombout(("No supported authentication methods available"));
4042 crStop(0);
4043 }
edd0cb8a 4044 s->cur_prompt->to_server = TRUE;
4045 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 4046 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4047 ssh->username, ssh->savedhost),
b61f81bc 4048 FALSE);
32874aea 4049 }
a52f067e 4050
614a20a0 4051 /*
4052 * Show password prompt, having first obtained it via a TIS
4053 * or CryptoCard exchange if we're doing TIS or CryptoCard
4054 * authentication.
4055 */
edd0cb8a 4056 {
4057 int ret; /* need not be kept over crReturn */
4058 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4059 while (ret < 0) {
4060 ssh->send_ok = 1;
4061 crWaitUntil(!pktin);
4062 ret = get_userpass_input(s->cur_prompt, in, inlen);
4063 ssh->send_ok = 0;
4064 }
4065 if (!ret) {
32874aea 4066 /*
edd0cb8a 4067 * Failed to get a password (for example
32874aea 4068 * because one was supplied on the command line
4069 * which has already failed to work). Terminate.
4070 */
edd0cb8a 4071 free_prompts(s->cur_prompt);
4072 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4073 crStop(0);
32874aea 4074 }
32874aea 4075 }
4076
edd0cb8a 4077 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 4078 /*
edd0cb8a 4079 * Defence against traffic analysis: we send a
4080 * whole bunch of packets containing strings of
4081 * different lengths. One of these strings is the
4082 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4083 * The others are all random data in
4084 * SSH1_MSG_IGNORE packets. This way a passive
4085 * listener can't tell which is the password, and
4086 * hence can't deduce the password length.
4087 *
4088 * Anybody with a password length greater than 16
4089 * bytes is going to have enough entropy in their
4090 * password that a listener won't find it _that_
4091 * much help to know how long it is. So what we'll
4092 * do is:
4093 *
4094 * - if password length < 16, we send 15 packets
4095 * containing string lengths 1 through 15
4096 *
4097 * - otherwise, we let N be the nearest multiple
4098 * of 8 below the password length, and send 8
4099 * packets containing string lengths N through
4100 * N+7. This won't obscure the order of
4101 * magnitude of the password length, but it will
4102 * introduce a bit of extra uncertainty.
4103 *
bf982899 4104 * A few servers can't deal with SSH1_MSG_IGNORE, at
4105 * least in this context. For these servers, we need
4106 * an alternative defence. We make use of the fact
4107 * that the password is interpreted as a C string:
4108 * so we can append a NUL, then some random data.
edd0cb8a 4109 *
bf982899 4110 * A few servers can deal with neither SSH1_MSG_IGNORE
4111 * here _nor_ a padded password string.
4112 * For these servers we are left with no defences
edd0cb8a 4113 * against password length sniffing.
32874aea 4114 */
bf982899 4115 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4116 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 4117 /*
edd0cb8a 4118 * The server can deal with SSH1_MSG_IGNORE, so
4119 * we can use the primary defence.
32874aea 4120 */
edd0cb8a 4121 int bottom, top, pwlen, i;
4122 char *randomstr;
32874aea 4123
edd0cb8a 4124 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4125 if (pwlen < 16) {
4126 bottom = 0; /* zero length passwords are OK! :-) */
4127 top = 15;
4128 } else {
4129 bottom = pwlen & ~7;
4130 top = bottom + 7;
4131 }
32874aea 4132
edd0cb8a 4133 assert(pwlen >= bottom && pwlen <= top);
32874aea 4134
edd0cb8a 4135 randomstr = snewn(top + 1, char);
32874aea 4136
edd0cb8a 4137 for (i = bottom; i <= top; i++) {
4138 if (i == pwlen) {
4139 defer_packet(ssh, s->pwpkt_type,
4140 PKTT_PASSWORD, PKT_STR,
4141 s->cur_prompt->prompts[0]->result,
4142 PKTT_OTHER, PKT_END);
4143 } else {
4144 for (j = 0; j < i; j++) {
4145 do {
4146 randomstr[j] = random_byte();
4147 } while (randomstr[j] == '\0');
32874aea 4148 }
edd0cb8a 4149 randomstr[i] = '\0';
4150 defer_packet(ssh, SSH1_MSG_IGNORE,
4151 PKT_STR, randomstr, PKT_END);
32874aea 4152 }
edd0cb8a 4153 }
4154 logevent("Sending password with camouflage packets");
4155 ssh_pkt_defersend(ssh);
4156 sfree(randomstr);
4157 }
4158 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4159 /*
4160 * The server can't deal with SSH1_MSG_IGNORE
4161 * but can deal with padded passwords, so we
4162 * can use the secondary defence.
4163 */
4164 char string[64];
4165 char *ss;
4166 int len;
4167
4168 len = strlen(s->cur_prompt->prompts[0]->result);
4169 if (len < sizeof(string)) {
4170 ss = string;
4171 strcpy(string, s->cur_prompt->prompts[0]->result);
4172 len++; /* cover the zero byte */
4173 while (len < sizeof(string)) {
4174 string[len++] = (char) random_byte();
bd358db1 4175 }
bd358db1 4176 } else {
edd0cb8a 4177 ss = s->cur_prompt->prompts[0]->result;
32874aea 4178 }
edd0cb8a 4179 logevent("Sending length-padded password");
9a10ecf4 4180 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 4181 PKT_INT, len, PKT_DATA, ss, len,
4182 PKTT_OTHER, PKT_END);
4183 } else {
4184 /*
bf982899 4185 * The server is believed unable to cope with
4186 * any of our password camouflage methods.
edd0cb8a 4187 */
4188 int len;
4189 len = strlen(s->cur_prompt->prompts[0]->result);
4190 logevent("Sending unpadded password");
4191 send_packet(ssh, s->pwpkt_type,
4192 PKTT_PASSWORD, PKT_INT, len,
4193 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4194 PKTT_OTHER, PKT_END);
32874aea 4195 }
edd0cb8a 4196 } else {
4197 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4198 PKT_STR, s->cur_prompt->prompts[0]->result,
4199 PKTT_OTHER, PKT_END);
32874aea 4200 }
c5e9c988 4201 logevent("Sent password");
edd0cb8a 4202 free_prompts(s->cur_prompt);
ff3187f6 4203 crWaitUntil(pktin);
4204 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4205 if (flags & FLAG_VERBOSE)
51470298 4206 c_write_str(ssh, "Access denied\r\n");
c5e9c988 4207 logevent("Authentication refused");
ff3187f6 4208 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4209 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 4210 crStop(0);
374330e2 4211 }
4212 }
4213
edd0cb8a 4214 /* Clear up */
4215 if (s->publickey_blob) {
4216 sfree(s->publickey_blob);
4217 sfree(s->publickey_comment);
4218 }
4219
c5e9c988 4220 logevent("Authentication successful");
4221
fb09bf1c 4222 crFinish(1);
4223}
4224
bc06669b 4225static void ssh_channel_try_eof(struct ssh_channel *c)
4226{
4227 Ssh ssh = c->ssh;
4228 assert(c->pending_eof); /* precondition for calling us */
4229 if (c->halfopen)
4230 return; /* can't close: not even opened yet */
4231 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4232 return; /* can't send EOF: pending outgoing data */
4233
4234 if (ssh->version == 1) {
4235 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4236 PKT_END);
4237 c->closes |= CLOSES_SENT_EOF;
4238 } else {
4239 struct Packet *pktout;
4240 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4241 ssh2_pkt_adduint32(pktout, c->remoteid);
4242 ssh2_pkt_send(ssh, pktout);
4243 c->closes |= CLOSES_SENT_EOF;
4244 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes)) {
4245 /*
4246 * Also send MSG_CLOSE.
4247 */
4248 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4249 ssh2_pkt_adduint32(pktout, c->remoteid);
4250 ssh2_pkt_send(ssh, pktout);
4251 c->closes |= CLOSES_SENT_CLOSE;
4252 }
4253 }
4254 c->pending_eof = FALSE; /* we've sent it now */
4255}
4256
4257void sshfwd_write_eof(struct ssh_channel *c)
32874aea 4258{
51470298 4259 Ssh ssh = c->ssh;
4260
1ef619ae 4261 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4262 return;
36f94d1f 4263
bc06669b 4264 if (c->closes & CLOSES_SENT_EOF)
4265 return;
78280721 4266
bc06669b 4267 c->pending_eof = TRUE;
4268 ssh_channel_try_eof(c);
32874aea 4269}
4270
c6b41791 4271void sshfwd_unclean_close(struct ssh_channel *c)
4272{
4273 Ssh ssh = c->ssh;
4274 struct Packet *pktout;
4275
4276 if (ssh->state == SSH_STATE_CLOSED)
4277 return;
4278
96210393 4279 if (!(c->closes & CLOSES_SENT_CLOSE)) {
4280 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4281 ssh2_pkt_adduint32(pktout, c->remoteid);
4282 ssh2_pkt_send(ssh, pktout);
4283 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
4284 }
c6b41791 4285
c6b41791 4286 switch (c->type) {
4287 case CHAN_X11:
4288 x11_close(c->u.x11.s);
4289 break;
4290 case CHAN_SOCKDATA:
4291 case CHAN_SOCKDATA_DORMANT:
4292 pfd_close(c->u.pfd.s);
4293 break;
4294 }
4295 c->type = CHAN_ZOMBIE;
96210393 4296
c6b41791 4297 ssh2_channel_check_close(c);
4298}
4299
5471d09a 4300int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4301{
51470298 4302 Ssh ssh = c->ssh;
4303
1ef619ae 4304 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4305 return 0;
36f94d1f 4306
51470298 4307 if (ssh->version == 1) {
4308 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4309 PKT_INT, c->remoteid,
a2724fba 4310 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4311 PKTT_OTHER, PKT_END);
5471d09a 4312 /*
2e85c969 4313 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4314 * connections are never individually throttled - because
4315 * the only circumstance that can cause throttling will be
4316 * the whole SSH connection backing up, in which case
4317 * _everything_ will be throttled as a whole.
4318 */
4319 return 0;
783415f8 4320 } else {
32874aea 4321 ssh2_add_channel_data(c, buf, len);
5471d09a 4322 return ssh2_try_send(c);
4323 }
4324}
4325
4326void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4327{
51470298 4328 Ssh ssh = c->ssh;
ff68564b 4329 int buflimit;
51470298 4330
1ef619ae 4331 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4332 return;
36f94d1f 4333
51470298 4334 if (ssh->version == 1) {
ff68564b 4335 buflimit = SSH1_BUFFER_LIMIT;
5471d09a 4336 } else {
ff68564b 4337 buflimit = c->v.v2.locmaxwin;
4338 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4339 }
4340 if (c->throttling_conn && bufsize <= buflimit) {
4341 c->throttling_conn = 0;
4342 ssh_throttle_conn(ssh, -1);
783415f8 4343 }
9c964e85 4344}
4345
06fadff5 4346static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4347{
4348 struct queued_handler *qh = ssh->qhead;
4349
4350 assert(qh != NULL);
4351
4352 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4353
4354 if (qh->msg1 > 0) {
4355 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4356 ssh->packet_dispatch[qh->msg1] = NULL;
4357 }
4358 if (qh->msg2 > 0) {
4359 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4360 ssh->packet_dispatch[qh->msg2] = NULL;
4361 }
4362
4363 if (qh->next) {
4364 ssh->qhead = qh->next;
4365
4366 if (ssh->qhead->msg1 > 0) {
4367 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4368 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4369 }
4370 if (ssh->qhead->msg2 > 0) {
4371 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4372 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4373 }
4374 } else {
4375 ssh->qhead = ssh->qtail = NULL;
4376 ssh->packet_dispatch[pktin->type] = NULL;
4377 }
4378
4379 qh->handler(ssh, pktin, qh->ctx);
4380
4381 sfree(qh);
4382}
4383
4384static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4385 chandler_fn_t handler, void *ctx)
4386{
4387 struct queued_handler *qh;
4388
4389 qh = snew(struct queued_handler);
4390 qh->msg1 = msg1;
4391 qh->msg2 = msg2;
4392 qh->handler = handler;
4393 qh->ctx = ctx;
4394 qh->next = NULL;
4395
4396 if (ssh->qtail == NULL) {
4397 ssh->qhead = qh;
4398
4399 if (qh->msg1 > 0) {
4400 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4401 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4402 }
4403 if (qh->msg2 > 0) {
4404 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4405 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4406 }
4407 } else {
4408 ssh->qtail->next = qh;
4409 }
4410 ssh->qtail = qh;
4411}
4412
4413static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4414{
4415 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4416
4417 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4418 SSH2_MSG_REQUEST_SUCCESS)) {
4419 logeventf(ssh, "Remote port forwarding from %s enabled",
4420 pf->sportdesc);
4421 } else {
4422 logeventf(ssh, "Remote port forwarding from %s refused",
4423 pf->sportdesc);
4424
4425 rpf = del234(ssh->rportfwds, pf);
4426 assert(rpf == pf);
8aea57fd 4427 pf->pfrec->remote = NULL;
fda2feb1 4428 free_rportfwd(pf);
06fadff5 4429 }
4430}
4431
4a693cfc 4432static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
06fadff5 4433{
84328ddb 4434 struct ssh_portfwd *epf;
4435 int i;
4a693cfc 4436 char *key, *val;
06fadff5 4437
fda2feb1 4438 if (!ssh->portfwds) {
4439 ssh->portfwds = newtree234(ssh_portcmp);
4440 } else {
4441 /*
4442 * Go through the existing port forwardings and tag them
84328ddb 4443 * with status==DESTROY. Any that we want to keep will be
4444 * re-enabled (status==KEEP) as we go through the
4445 * configuration and find out which bits are the same as
4446 * they were before.
fda2feb1 4447 */
4448 struct ssh_portfwd *epf;
4449 int i;
4450 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 4451 epf->status = DESTROY;
fda2feb1 4452 }
4453
4a693cfc 4454 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4455 val != NULL;
4456 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4457 char *kp, *kp2, *vp, *vp2;
84328ddb 4458 char address_family, type;
4459 int sport,dport,sserv,dserv;
4a693cfc 4460 char *sports, *dports, *saddr, *host;
4461
4462 kp = key;
84328ddb 4463
05581745 4464 address_family = 'A';
4465 type = 'L';
4a693cfc 4466 if (*kp == 'A' || *kp == '4' || *kp == '6')
4467 address_family = *kp++;
4468 if (*kp == 'L' || *kp == 'R')
4469 type = *kp++;
4470
4471 if ((kp2 = strchr(kp, ':')) != NULL) {
4472 /*
4473 * There's a colon in the middle of the source port
4474 * string, which means that the part before it is
4475 * actually a source address.
4476 */
4477 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4478 sports = kp2+1;
06fadff5 4479 } else {
4a693cfc 4480 saddr = NULL;
4481 sports = kp;
06fadff5 4482 }
4483 sport = atoi(sports);
4484 sserv = 0;
4485 if (sport == 0) {
4486 sserv = 1;
4487 sport = net_service_lookup(sports);
4488 if (!sport) {
4489 logeventf(ssh, "Service lookup failed for source"
4490 " port \"%s\"", sports);
4491 }
4492 }
4a693cfc 4493
4494 if (type == 'L' && !strcmp(val, "D")) {
4495 /* dynamic forwarding */
4496 host = NULL;
4497 dports = NULL;
4498 dport = -1;
4499 dserv = 0;
4500 type = 'D';
4501 } else {
4502 /* ordinary forwarding */
4503 vp = val;
4504 vp2 = vp + strcspn(vp, ":");
4505 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4506 if (vp2)
4507 vp2++;
4508 dports = vp2;
4509 dport = atoi(dports);
4510 dserv = 0;
4511 if (dport == 0) {
4512 dserv = 1;
4513 dport = net_service_lookup(dports);
4514 if (!dport) {
4515 logeventf(ssh, "Service lookup failed for destination"
4516 " port \"%s\"", dports);
4517 }
4518 }
4519 }
4520
06fadff5 4521 if (sport && dport) {
4522 /* Set up a description of the source port. */
fda2feb1 4523 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4524
4525 pfrec = snew(struct ssh_portfwd);
4526 pfrec->type = type;
4a693cfc 4527 pfrec->saddr = saddr;
3fe92132 4528 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4529 pfrec->sport = sport;
4a693cfc 4530 pfrec->daddr = host;
3fe92132 4531 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4532 pfrec->dport = dport;
4533 pfrec->local = NULL;
4534 pfrec->remote = NULL;
05581745 4535 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4536 address_family == '6' ? ADDRTYPE_IPV6 :
4537 ADDRTYPE_UNSPEC);
fda2feb1 4538
4539 epfrec = add234(ssh->portfwds, pfrec);
4540 if (epfrec != pfrec) {
c00c1931 4541 if (epfrec->status == DESTROY) {
4542 /*
4543 * We already have a port forwarding up and running
4544 * with precisely these parameters. Hence, no need
4545 * to do anything; simply re-tag the existing one
4546 * as KEEP.
4547 */
4548 epfrec->status = KEEP;
4549 }
fda2feb1 4550 /*
c00c1931 4551 * Anything else indicates that there was a duplicate
4552 * in our input, which we'll silently ignore.
fda2feb1 4553 */
fda2feb1 4554 free_portfwd(pfrec);
84328ddb 4555 } else {
4556 pfrec->status = CREATE;
4557 }
4a693cfc 4558 } else {
4559 sfree(saddr);
4560 sfree(host);
84328ddb 4561 }
4562 }
4563
4564 /*
4565 * Now go through and destroy any port forwardings which were
4566 * not re-enabled.
4567 */
4568 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4569 if (epf->status == DESTROY) {
4570 char *message;
4571
4572 message = dupprintf("%s port forwarding from %s%s%d",
4573 epf->type == 'L' ? "local" :
4574 epf->type == 'R' ? "remote" : "dynamic",
4575 epf->saddr ? epf->saddr : "",
4576 epf->saddr ? ":" : "",
4577 epf->sport);
4578
4579 if (epf->type != 'D') {
4580 char *msg2 = dupprintf("%s to %s:%d", message,
4581 epf->daddr, epf->dport);
4582 sfree(message);
4583 message = msg2;
4584 }
4585
4586 logeventf(ssh, "Cancelling %s", message);
4587 sfree(message);
4588
8aea57fd 4589 /* epf->remote or epf->local may be NULL if setting up a
4590 * forwarding failed. */
84328ddb 4591 if (epf->remote) {
4592 struct ssh_rportfwd *rpf = epf->remote;
4593 struct Packet *pktout;
4594
4595 /*
4596 * Cancel the port forwarding at the server
4597 * end.
4598 */
4599 if (ssh->version == 1) {
4600 /*
4601 * We cannot cancel listening ports on the
2e85c969 4602 * server side in SSH-1! There's no message
84328ddb 4603 * to support it. Instead, we simply remove
4604 * the rportfwd record from the local end
4605 * so that any connections the server tries
4606 * to make on it are rejected.
4607 */
4608 } else {
4609 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4610 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4611 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4612 if (epf->saddr) {
4613 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4614 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4615 /* XXX: rport_acceptall may not represent
5188540b 4616 * what was used to open the original connection,
4617 * since it's reconfigurable. */
84328ddb 4618 ssh2_pkt_addstring(pktout, "0.0.0.0");
4619 } else {
4620 ssh2_pkt_addstring(pktout, "127.0.0.1");
4621 }
4622 ssh2_pkt_adduint32(pktout, epf->sport);
4623 ssh2_pkt_send(ssh, pktout);
4624 }
4625
4626 del234(ssh->rportfwds, rpf);
4627 free_rportfwd(rpf);
4628 } else if (epf->local) {
4629 pfd_terminate(epf->local);
4630 }
4631
4632 delpos234(ssh->portfwds, i);
4633 free_portfwd(epf);
4634 i--; /* so we don't skip one in the list */
4635 }
4636
4637 /*
4638 * And finally, set up any new port forwardings (status==CREATE).
4639 */
4640 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4641 if (epf->status == CREATE) {
4642 char *sportdesc, *dportdesc;
3fe92132 4643 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4644 epf->saddr ? epf->saddr : "",
4645 epf->saddr ? ":" : "",
3fe92132 4646 epf->sserv ? epf->sserv : "",
4647 epf->sserv ? "(" : "",
4648 epf->sport,
4649 epf->sserv ? ")" : "");
84328ddb 4650 if (epf->type == 'D') {
4651 dportdesc = NULL;
4652 } else {
3fe92132 4653 dportdesc = dupprintf("%s:%s%s%d%s",
4654 epf->daddr,
4655 epf->dserv ? epf->dserv : "",
4656 epf->dserv ? "(" : "",
4657 epf->dport,
4658 epf->dserv ? ")" : "");
84328ddb 4659 }
05581745 4660
84328ddb 4661 if (epf->type == 'L') {
4662 const char *err = pfd_addforward(epf->daddr, epf->dport,
4663 epf->saddr, epf->sport,
4a693cfc 4664 ssh, conf,
84328ddb 4665 &epf->local,
4666 epf->addressfamily);
4667
4668 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4669 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4670 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4671 sportdesc, dportdesc,
4672 err ? " failed: " : "", err ? err : "");
4673 } else if (epf->type == 'D') {
06fadff5 4674 const char *err = pfd_addforward(NULL, -1,
84328ddb 4675 epf->saddr, epf->sport,
4a693cfc 4676 ssh, conf,
84328ddb 4677 &epf->local,
4678 epf->addressfamily);
4679
4680 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4681 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4682 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4683 sportdesc,
4684 err ? " failed: " : "", err ? err : "");
06fadff5 4685 } else {
4686 struct ssh_rportfwd *pf;
4687
4688 /*
4689 * Ensure the remote port forwardings tree exists.
4690 */
4691 if (!ssh->rportfwds) {
4692 if (ssh->version == 1)
4693 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4694 else
4695 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4696 }
4697
4698 pf = snew(struct ssh_rportfwd);
84328ddb 4699 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4700 pf->dhost[lenof(pf->dhost)-1] = '\0';
4701 pf->dport = epf->dport;
4702 pf->sport = epf->sport;
06fadff5 4703 if (add234(ssh->rportfwds, pf) != pf) {
4704 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4705 epf->daddr, epf->dport);
06fadff5 4706 sfree(pf);
4707 } else {
4708 logeventf(ssh, "Requesting remote port %s"
84328ddb 4709 " forward to %s", sportdesc, dportdesc);
06fadff5 4710
4711 pf->sportdesc = sportdesc;
4712 sportdesc = NULL;
84328ddb 4713 epf->remote = pf;
4714 pf->pfrec = epf;
06fadff5 4715
4716 if (ssh->version == 1) {
4717 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4718 PKT_INT, epf->sport,
4719 PKT_STR, epf->daddr,
4720 PKT_INT, epf->dport,
06fadff5 4721 PKT_END);
4722 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4723 SSH1_SMSG_FAILURE,
4724 ssh_rportfwd_succfail, pf);
4725 } else {
4726 struct Packet *pktout;
4727 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4728 ssh2_pkt_addstring(pktout, "tcpip-forward");
4729 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4730 if (epf->saddr) {
4731 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4732 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
06fadff5 4733 ssh2_pkt_addstring(pktout, "0.0.0.0");
4734 } else {
4735 ssh2_pkt_addstring(pktout, "127.0.0.1");
4736 }
84328ddb 4737 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4738 ssh2_pkt_send(ssh, pktout);
4739
4740 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4741 SSH2_MSG_REQUEST_FAILURE,
4742 ssh_rportfwd_succfail, pf);
4743 }
4744 }
4745 }
4746 sfree(sportdesc);
84328ddb 4747 sfree(dportdesc);
06fadff5 4748 }
06fadff5 4749}
4750
51df0ab5 4751static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4752{
4753 char *string;
4754 int stringlen, bufsize;
4755
4756 ssh_pkt_getstring(pktin, &string, &stringlen);
4757 if (string == NULL) {
4758 bombout(("Incoming terminal data packet was badly formed"));
4759 return;
4760 }
4761
4762 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4763 string, stringlen);
4764 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4765 ssh->v1_stdout_throttling = 1;
ff68564b 4766 ssh_throttle_conn(ssh, +1);
51df0ab5 4767 }
4768}
4769
4770static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4771{
4772 /* Remote side is trying to open a channel to talk to our
4773 * X-Server. Give them back a local channel number. */
4774 struct ssh_channel *c;
4775 int remoteid = ssh_pkt_getuint32(pktin);
4776
4777 logevent("Received X11 connect request");
4778 /* Refuse if X11 forwarding is disabled. */
4779 if (!ssh->X11_fwd_enabled) {
4780 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4781 PKT_INT, remoteid, PKT_END);
4782 logevent("Rejected X11 connect request");
4783 } else {
4784 c = snew(struct ssh_channel);
4785 c->ssh = ssh;
4786
8def70c3 4787 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 4788 NULL, -1, ssh->conf) != NULL) {
51df0ab5 4789 logevent("Opening X11 forward connection failed");
4790 sfree(c);
4791 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4792 PKT_INT, remoteid, PKT_END);
4793 } else {
4794 logevent
4795 ("Opening X11 forward connection succeeded");
4796 c->remoteid = remoteid;
64d6ff88 4797 c->halfopen = FALSE;
51df0ab5 4798 c->localid = alloc_channel_id(ssh);
4799 c->closes = 0;
bc06669b 4800 c->pending_eof = FALSE;
ff68564b 4801 c->throttling_conn = 0;
51df0ab5 4802 c->type = CHAN_X11; /* identify channel type */
4803 add234(ssh->channels, c);
4804 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4805 PKT_INT, c->remoteid, PKT_INT,
4806 c->localid, PKT_END);
4807 logevent("Opened X11 forward channel");
4808 }
4809 }
4810}
4811
4812static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4813{
4814 /* Remote side is trying to open a channel to talk to our
4815 * agent. Give them back a local channel number. */
4816 struct ssh_channel *c;
4817 int remoteid = ssh_pkt_getuint32(pktin);
4818
4819 /* Refuse if agent forwarding is disabled. */
4820 if (!ssh->agentfwd_enabled) {
4821 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4822 PKT_INT, remoteid, PKT_END);
4823 } else {
4824 c = snew(struct ssh_channel);
4825 c->ssh = ssh;
4826 c->remoteid = remoteid;
64d6ff88 4827 c->halfopen = FALSE;
51df0ab5 4828 c->localid = alloc_channel_id(ssh);
4829 c->closes = 0;
bc06669b 4830 c->pending_eof = FALSE;
ff68564b 4831 c->throttling_conn = 0;
51df0ab5 4832 c->type = CHAN_AGENT; /* identify channel type */
4833 c->u.a.lensofar = 0;
bc06669b 4834 c->u.a.message = NULL;
51df0ab5 4835 add234(ssh->channels, c);
4836 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4837 PKT_INT, c->remoteid, PKT_INT, c->localid,
4838 PKT_END);
4839 }
4840}
4841
4842static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4843{
4844 /* Remote side is trying to open a channel to talk to a
4845 * forwarded port. Give them back a local channel number. */
4846 struct ssh_channel *c;
05581745 4847 struct ssh_rportfwd pf, *pfp;
51df0ab5 4848 int remoteid;
4849 int hostsize, port;
fb983202 4850 char *host;
51df0ab5 4851 const char *e;
4852 c = snew(struct ssh_channel);
4853 c->ssh = ssh;
4854
4855 remoteid = ssh_pkt_getuint32(pktin);
4856 ssh_pkt_getstring(pktin, &host, &hostsize);
4857 port = ssh_pkt_getuint32(pktin);
4858
4859 if (hostsize >= lenof(pf.dhost))
4860 hostsize = lenof(pf.dhost)-1;
4861 memcpy(pf.dhost, host, hostsize);
4862 pf.dhost[hostsize] = '\0';
4863 pf.dport = port;
05581745 4864 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4865
05581745 4866 if (pfp == NULL) {
fb983202 4867 logeventf(ssh, "Rejected remote port open request for %s:%d",
4868 pf.dhost, port);
51df0ab5 4869 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4870 PKT_INT, remoteid, PKT_END);
4871 } else {
fb983202 4872 logeventf(ssh, "Received remote port open request for %s:%d",
4873 pf.dhost, port);
51df0ab5 4874 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4a693cfc 4875 c, ssh->conf, pfp->pfrec->addressfamily);
51df0ab5 4876 if (e != NULL) {
fb983202 4877 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4878 sfree(c);
4879 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4880 PKT_INT, remoteid, PKT_END);
4881 } else {
4882 c->remoteid = remoteid;
64d6ff88 4883 c->halfopen = FALSE;
51df0ab5 4884 c->localid = alloc_channel_id(ssh);
4885 c->closes = 0;
bc06669b 4886 c->pending_eof = FALSE;
ff68564b 4887 c->throttling_conn = 0;
51df0ab5 4888 c->type = CHAN_SOCKDATA; /* identify channel type */
4889 add234(ssh->channels, c);
4890 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4891 PKT_INT, c->remoteid, PKT_INT,
4892 c->localid, PKT_END);
4893 logevent("Forwarded port opened successfully");
4894 }
4895 }
4896}
4897
4898static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4899{
4900 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4901 unsigned int localid = ssh_pkt_getuint32(pktin);
4902 struct ssh_channel *c;
4903
4904 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4905 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4906 c->remoteid = localid;
64d6ff88 4907 c->halfopen = FALSE;
51df0ab5 4908 c->type = CHAN_SOCKDATA;
ff68564b 4909 c->throttling_conn = 0;
51df0ab5 4910 pfd_confirm(c->u.pfd.s);
4911 }
4912
bc06669b 4913 if (c && c->pending_eof) {
51df0ab5 4914 /*
4915 * We have a pending close on this channel,
4916 * which we decided on before the server acked
4917 * the channel open. So now we know the
4918 * remoteid, we can close it again.
4919 */
bc06669b 4920 ssh_channel_try_eof(c);
51df0ab5 4921 }
4922}
4923
4924static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4925{
4926 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4927 struct ssh_channel *c;
4928
4929 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4930 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4931 logevent("Forwarded connection refused by server");
4932 pfd_close(c->u.pfd.s);
4933 del234(ssh->channels, c);
4934 sfree(c);
4935 }
4936}
4937
4938static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4939{
4940 /* Remote side closes a channel. */
4941 unsigned i = ssh_pkt_getuint32(pktin);
4942 struct ssh_channel *c;
4943 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4944 if (c && !c->halfopen) {
51df0ab5 4945
bc06669b 4946 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4947 !(c->closes & CLOSES_RCVD_EOF)) {
4948 /*
4949 * Received CHANNEL_CLOSE, which we translate into
4950 * outgoing EOF.
4951 */
4952 int send_close = FALSE;
4953
4954 c->closes |= CLOSES_RCVD_EOF;
4955
4956 switch (c->type) {
4957 case CHAN_X11:
4958 if (c->u.x11.s)
4959 x11_send_eof(c->u.x11.s);
4960 else
4961 send_close = TRUE;
4962 case CHAN_SOCKDATA:
4963 if (c->u.pfd.s)
4964 x11_send_eof(c->u.pfd.s);
4965 else
4966 send_close = TRUE;
4967 case CHAN_AGENT:
4968 send_close = TRUE;
4969 }
51df0ab5 4970
bc06669b 4971 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
4972 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4973 PKT_END);
4974 c->closes |= CLOSES_SENT_EOF;
4975 }
4976 }
4977
4978 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
4979 !(c->closes & CLOSES_RCVD_CLOSE)) {
4980
4981 if (!(c->closes & CLOSES_SENT_EOF)) {
4982 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4983 " for which we never sent CHANNEL_CLOSE\n", i));
4984 }
4985
4986 c->closes |= CLOSES_RCVD_CLOSE;
4987 }
4988
4989 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
4990 !(c->closes & CLOSES_SENT_CLOSE)) {
4991 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
4992 PKT_INT, c->remoteid, PKT_END);
4993 c->closes |= CLOSES_SENT_CLOSE;
4994 }
4995
4996 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
4997 ssh_channel_destroy(c);
51df0ab5 4998 } else {
4999 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5000 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5001 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5002 i));
5003 }
5004}
5005
5006static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5007{
5008 /* Data sent down one of our channels. */
5009 int i = ssh_pkt_getuint32(pktin);
5010 char *p;
6d44acc9 5011 int len;
51df0ab5 5012 struct ssh_channel *c;
5013
5014 ssh_pkt_getstring(pktin, &p, &len);
5015
5016 c = find234(ssh->channels, &i, ssh_channelfind);
5017 if (c) {
5018 int bufsize = 0;
5019 switch (c->type) {
5020 case CHAN_X11:
5021 bufsize = x11_send(c->u.x11.s, p, len);
5022 break;
5023 case CHAN_SOCKDATA:
5024 bufsize = pfd_send(c->u.pfd.s, p, len);
5025 break;
5026 case CHAN_AGENT:
5027 /* Data for an agent message. Buffer it. */
5028 while (len > 0) {
5029 if (c->u.a.lensofar < 4) {
62ddb51e 5030 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 5031 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5032 l);
5033 p += l;
5034 len -= l;
5035 c->u.a.lensofar += l;
5036 }
5037 if (c->u.a.lensofar == 4) {
5038 c->u.a.totallen =
5039 4 + GET_32BIT(c->u.a.msglen);
5040 c->u.a.message = snewn(c->u.a.totallen,
5041 unsigned char);
5042 memcpy(c->u.a.message, c->u.a.msglen, 4);
5043 }
5044 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 5045 unsigned int l =
51df0ab5 5046 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 5047 (unsigned)len);
51df0ab5 5048 memcpy(c->u.a.message + c->u.a.lensofar, p,
5049 l);
5050 p += l;
5051 len -= l;
5052 c->u.a.lensofar += l;
5053 }
5054 if (c->u.a.lensofar == c->u.a.totallen) {
5055 void *reply;
5056 int replylen;
5057 if (agent_query(c->u.a.message,
5058 c->u.a.totallen,
5059 &reply, &replylen,
5060 ssh_agentf_callback, c))
5061 ssh_agentf_callback(c, reply, replylen);
5062 sfree(c->u.a.message);
5063 c->u.a.lensofar = 0;
5064 }
5065 }
5066 bufsize = 0; /* agent channels never back up */
5067 break;
5068 }
ff68564b 5069 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5070 c->throttling_conn = 1;
5071 ssh_throttle_conn(ssh, +1);
51df0ab5 5072 }
5073 }
5074}
5075
5076static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5077{
51df0ab5 5078 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 5079 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 5080 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5081 /*
5082 * In case `helpful' firewalls or proxies tack
5083 * extra human-readable text on the end of the
5084 * session which we might mistake for another
5085 * encrypted packet, we close the session once
5086 * we've sent EXIT_CONFIRMATION.
5087 */
9e296bfa 5088 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 5089}
5090
c6ccd5c2 5091/* Helper function to deal with sending tty modes for REQUEST_PTY */
5092static void ssh1_send_ttymode(void *data, char *mode, char *val)
5093{
5094 struct Packet *pktout = (struct Packet *)data;
5095 int i = 0;
5096 unsigned int arg = 0;
5097 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5098 if (i == lenof(ssh_ttymodes)) return;
5099 switch (ssh_ttymodes[i].type) {
5100 case TTY_OP_CHAR:
5101 arg = ssh_tty_parse_specchar(val);
5102 break;
5103 case TTY_OP_BOOL:
5104 arg = ssh_tty_parse_boolean(val);
5105 break;
5106 }
5107 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5108 ssh2_pkt_addbyte(pktout, arg);
5109}
5110
5111
b09eaa88 5112static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5113 struct Packet *pktin)
32874aea 5114{
b09eaa88 5115 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 5116
51df0ab5 5117 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5118 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5119 ssh1_smsg_stdout_stderr_data;
5120
5121 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5122 ssh1_msg_channel_open_confirmation;
5123 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5124 ssh1_msg_channel_open_failure;
5125 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5126 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5127 ssh1_msg_channel_close;
5128 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5129 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5130
4a693cfc 5131 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 5132 logevent("Requesting agent forwarding");
51470298 5133 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 5134 do {
5135 crReturnV;
ff3187f6 5136 } while (!pktin);
5137 if (pktin->type != SSH1_SMSG_SUCCESS
5138 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5139 bombout(("Protocol confusion"));
7ffdbc1a 5140 crStopV;
ff3187f6 5141 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5142 logevent("Agent forwarding refused");
5143 } else {
5144 logevent("Agent forwarding enabled");
51470298 5145 ssh->agentfwd_enabled = TRUE;
51df0ab5 5146 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 5147 }
dacbd0e8 5148 }
5149
4a693cfc 5150 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5151 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5152 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 5153 logevent("Requesting X11 forwarding");
f68353be 5154 /*
5155 * Note that while we blank the X authentication data here, we don't
5156 * take any special action to blank the start of an X11 channel,
5157 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5158 * without having session blanking enabled is likely to leak your
5159 * cookie into the log.
5160 */
51470298 5161 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5162 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5163 PKT_STR, ssh->x11disp->remoteauthprotoname,
5164 PKTT_PASSWORD,
5165 PKT_STR, ssh->x11disp->remoteauthdatastring,
5166 PKTT_OTHER,
5167 PKT_INT, ssh->x11disp->screennum,
421d6835 5168 PKT_END);
32874aea 5169 } else {
51470298 5170 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5171 PKT_STR, ssh->x11disp->remoteauthprotoname,
5172 PKTT_PASSWORD,
5173 PKT_STR, ssh->x11disp->remoteauthdatastring,
5174 PKTT_OTHER,
5175 PKT_END);
32874aea 5176 }
5177 do {
5178 crReturnV;
ff3187f6 5179 } while (!pktin);
5180 if (pktin->type != SSH1_SMSG_SUCCESS
5181 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5182 bombout(("Protocol confusion"));
7ffdbc1a 5183 crStopV;
ff3187f6 5184 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5185 logevent("X11 forwarding refused");
5186 } else {
5187 logevent("X11 forwarding enabled");
51470298 5188 ssh->X11_fwd_enabled = TRUE;
51df0ab5 5189 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 5190 }
5191 }
5192
4a693cfc 5193 ssh_setup_portfwd(ssh, ssh->conf);
06fadff5 5194 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 5195
4a693cfc 5196 if (!conf_get_int(ssh->conf, CONF_nopty)) {
c6ccd5c2 5197 struct Packet *pkt;
a5dd8467 5198 /* Unpick the terminal-speed string. */
5199 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5200 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 5201 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5202 /* Send the pty request. */
c6ccd5c2 5203 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4a693cfc 5204 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
c6ccd5c2 5205 ssh_pkt_adduint32(pkt, ssh->term_height);
5206 ssh_pkt_adduint32(pkt, ssh->term_width);
5207 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5208 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4a693cfc 5209 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
c6ccd5c2 5210 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5211 ssh_pkt_adduint32(pkt, ssh->ispeed);
5212 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5213 ssh_pkt_adduint32(pkt, ssh->ospeed);
5214 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5215 s_wrpkt(ssh, pkt);
51470298 5216 ssh->state = SSH_STATE_INTERMED;
32874aea 5217 do {
5218 crReturnV;
ff3187f6 5219 } while (!pktin);
5220 if (pktin->type != SSH1_SMSG_SUCCESS
5221 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5222 bombout(("Protocol confusion"));
7ffdbc1a 5223 crStopV;
ff3187f6 5224 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5225 c_write_str(ssh, "Server refused to allocate pty\r\n");
5226 ssh->editing = ssh->echoing = 1;
4a202fc6 5227 } else {
5228 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5229 ssh->ospeed, ssh->ispeed);
5230 ssh->got_pty = TRUE;
5231 }
0965bee0 5232 } else {
51470298 5233 ssh->editing = ssh->echoing = 1;
374330e2 5234 }
5235
4a693cfc 5236 if (conf_get_int(ssh->conf, CONF_compression)) {
51470298 5237 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 5238 do {
5239 crReturnV;
ff3187f6 5240 } while (!pktin);
5241 if (pktin->type != SSH1_SMSG_SUCCESS
5242 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5243 bombout(("Protocol confusion"));
7ffdbc1a 5244 crStopV;
ff3187f6 5245 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5246 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 5247 }
4ba9b64b 5248 logevent("Started compression");
51470298 5249 ssh->v1_compressing = TRUE;
5366aed8 5250 ssh->cs_comp_ctx = zlib_compress_init();
5251 logevent("Initialised zlib (RFC1950) compression");
5252 ssh->sc_comp_ctx = zlib_decompress_init();
5253 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 5254 }
5255
fd5e5847 5256 /*
5257 * Start the shell or command.
5258 *
2e85c969 5259 * Special case: if the first-choice command is an SSH-2
fd5e5847 5260 * subsystem (hence not usable here) and the second choice
5261 * exists, we fall straight back to that.
5262 */
5263 {
4a693cfc 5264 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 5265
4a693cfc 5266 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5267 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5268 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
51470298 5269 ssh->fallback_cmd = TRUE;
fd5e5847 5270 }
5271 if (*cmd)
51470298 5272 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 5273 else
51470298 5274 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 5275 logevent("Started session");
5276 }
374330e2 5277
51470298 5278 ssh->state = SSH_STATE_SESSION;
5279 if (ssh->size_needed)
5280 ssh_size(ssh, ssh->term_width, ssh->term_height);
5281 if (ssh->eof_needed)
5282 ssh_special(ssh, TS_EOF);
374330e2 5283
b9d7bcad 5284 if (ssh->ldisc)
5285 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5286 ssh->send_ok = 1;
5287 ssh->channels = newtree234(ssh_channelcmp);
374330e2 5288 while (1) {
d74d141c 5289
51df0ab5 5290 /*
5291 * By this point, most incoming packets are already being
5292 * handled by the dispatch table, and we need only pay
5293 * attention to the unusual ones.
5294 */
0357890f 5295
51df0ab5 5296 crReturnV;
5297 if (pktin) {
5298 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 5299 /* may be from EXEC_SHELL on some servers */
ff3187f6 5300 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5301 /* may be from EXEC_SHELL on some servers
374330e2 5302 * if no pty is available or in other odd cases. Ignore */
374330e2 5303 } else {
ff3187f6 5304 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5305 crStopV;
374330e2 5306 }
5307 } else {
8df7a775 5308 while (inlen > 0) {
5309 int len = min(inlen, 512);
a2724fba 5310 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5311 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5312 PKTT_OTHER, PKT_END);
8df7a775 5313 in += len;
5314 inlen -= len;
5315 }
374330e2 5316 }
5317 }
5318
5319 crFinishV;
5320}
5321
5322/*
2e85c969 5323 * Handle the top-level SSH-2 protocol.
b09eaa88 5324 */
5325static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5326{
fb983202 5327 char *msg;
b09eaa88 5328 int msglen;
5329
5330 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5331 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5332}
5333
5334static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5335{
5336 /* log reason code in disconnect message */
5337 char *msg;
5338 int msglen;
5339
5340 ssh_pkt_getstring(pktin, &msg, &msglen);
5341 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5342}
5343
409bfa77 5344static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5345{
5346 /* Do nothing, because we're ignoring it! Duhh. */
5347}
5348
5349static void ssh1_protocol_setup(Ssh ssh)
5350{
5351 int i;
5352
5353 /*
5354 * Most messages are handled by the coroutines.
5355 */
5356 for (i = 0; i < 256; i++)
5357 ssh->packet_dispatch[i] = NULL;
5358
5359 /*
5360 * These special message types we install handlers for.
5361 */
5362 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5363 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5364 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5365}
5366
1c1a7262 5367static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5368 struct Packet *pktin)
5369{
1c1a7262 5370 unsigned char *in=(unsigned char*)vin;
b09eaa88 5371 if (ssh->state == SSH_STATE_CLOSED)
5372 return;
5373
5374 if (pktin && ssh->packet_dispatch[pktin->type]) {
5375 ssh->packet_dispatch[pktin->type](ssh, pktin);
5376 return;
5377 }
5378
5379 if (!ssh->protocol_initial_phase_done) {
5380 if (do_ssh1_login(ssh, in, inlen, pktin))
5381 ssh->protocol_initial_phase_done = TRUE;
5382 else
5383 return;
5384 }
5385
5386 do_ssh1_connection(ssh, in, inlen, pktin);
5387}
5388
5389/*
e5574168 5390 * Utility routine for decoding comma-separated strings in KEXINIT.
5391 */
32874aea 5392static int in_commasep_string(char *needle, char *haystack, int haylen)
5393{
57356d63 5394 int needlen;
5395 if (!needle || !haystack) /* protect against null pointers */
5396 return 0;
5397 needlen = strlen(needle);
e5574168 5398 while (1) {
32874aea 5399 /*
5400 * Is it at the start of the string?
5401 */
5402 if (haylen >= needlen && /* haystack is long enough */
5403 !memcmp(needle, haystack, needlen) && /* initial match */
5404 (haylen == needlen || haystack[needlen] == ',')
5405 /* either , or EOS follows */
5406 )
5407 return 1;
5408 /*
5409 * If not, search for the next comma and resume after that.
5410 * If no comma found, terminate.
5411 */
5412 while (haylen > 0 && *haystack != ',')
5413 haylen--, haystack++;
5414 if (haylen == 0)
5415 return 0;
5416 haylen--, haystack++; /* skip over comma itself */
e5574168 5417 }
5418}
5419
5420/*
b59743d5 5421 * Similar routine for checking whether we have the first string in a list.
5422 */
5423static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5424{
5425 int needlen;
5426 if (!needle || !haystack) /* protect against null pointers */
5427 return 0;
5428 needlen = strlen(needle);
5429 /*
5430 * Is it at the start of the string?
5431 */
5432 if (haylen >= needlen && /* haystack is long enough */
5433 !memcmp(needle, haystack, needlen) && /* initial match */
5434 (haylen == needlen || haystack[needlen] == ',')
5435 /* either , or EOS follows */
5436 )
5437 return 1;
5438 return 0;
5439}
5440
5441
5442/*
2e85c969 5443 * SSH-2 key creation method.
754c0df9 5444 * (Currently assumes 2 lots of any hash are sufficient to generate
5445 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5446 */
754c0df9 5447#define SSH2_MKKEY_ITERS (2)
b672f405 5448static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5449 unsigned char *keyspace)
32874aea 5450{
b672f405 5451 const struct ssh_hash *h = ssh->kex->hash;
5452 void *s;
5453 /* First hlen bytes. */
5454 s = h->init();
51470298 5455 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5456 hash_mpint(h, s, K);
5457 h->bytes(s, H, h->hlen);
5458 h->bytes(s, &chr, 1);
5459 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5460 h->final(s, keyspace);
5461 /* Next hlen bytes. */
5462 s = h->init();
51470298 5463 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5464 hash_mpint(h, s, K);
5465 h->bytes(s, H, h->hlen);
5466 h->bytes(s, keyspace, h->hlen);
5467 h->final(s, keyspace + h->hlen);
d39f364a 5468}
5469
5470/*
2e85c969 5471 * Handle the SSH-2 transport layer.
e5574168 5472 */
1c1a7262 5473static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5474 struct Packet *pktin)
e5574168 5475{
1c1a7262 5476 unsigned char *in = (unsigned char *)vin;
51470298 5477 struct do_ssh2_transport_state {
4763c1c2 5478 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5479 Bignum p, g, e, f, K;
3dc9a6a7 5480 void *our_kexinit;
5481 int our_kexinitlen;
51470298 5482 int kex_init_value, kex_reply_value;
5483 const struct ssh_mac **maclist;
5484 int nmacs;
5485 const struct ssh2_cipher *cscipher_tobe;
5486 const struct ssh2_cipher *sccipher_tobe;
5487 const struct ssh_mac *csmac_tobe;
5488 const struct ssh_mac *scmac_tobe;
5489 const struct ssh_compress *cscomp_tobe;
5490 const struct ssh_compress *sccomp_tobe;
fae1a71b 5491 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5492 int hostkeylen, siglen, rsakeylen;
51470298 5493 void *hkey; /* actual host key */
fae1a71b 5494 void *rsakey; /* for RSA kex */
754c0df9 5495 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5496 int n_preferred_kex;
34557659 5497 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5498 int n_preferred_ciphers;
5499 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5500 const struct ssh_compress *preferred_comp;
ab18ccff 5501 int userauth_succeeded; /* for delayed compression */
5502 int pending_compression;
e13bba36 5503 int got_session_id, activated_authconn;
ff3187f6 5504 struct Packet *pktout;
3d9449a1 5505 int dlgret;
5506 int guessok;
4763c1c2 5507 int ignorepkt;
51470298 5508 };
5509 crState(do_ssh2_transport_state);
5510
5511 crBegin(ssh->do_ssh2_transport_crstate);
5512
5513 s->cscipher_tobe = s->sccipher_tobe = NULL;
5514 s->csmac_tobe = s->scmac_tobe = NULL;
5515 s->cscomp_tobe = s->sccomp_tobe = NULL;
5516
e13bba36 5517 s->got_session_id = s->activated_authconn = FALSE;
ab18ccff 5518 s->userauth_succeeded = FALSE;
5519 s->pending_compression = FALSE;
e5574168 5520
e13bba36 5521 /*
5522 * Be prepared to work around the buggy MAC problem.
5523 */
5524 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5525 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5526 else
5527 s->maclist = macs, s->nmacs = lenof(macs);
5528
5529 begin_key_exchange:
acab36bc 5530 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5531 {
e13bba36 5532 int i, j, commalist_started;
5533
51470298 5534 /*
83e7d008 5535 * Set up the preferred key exchange. (NULL => warn below here)
5536 */
5537 s->n_preferred_kex = 0;
5538 for (i = 0; i < KEX_MAX; i++) {
4a693cfc 5539 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
83e7d008 5540 case KEX_DHGEX:
5541 s->preferred_kex[s->n_preferred_kex++] =
5542 &ssh_diffiehellman_gex;
5543 break;
5544 case KEX_DHGROUP14:
5545 s->preferred_kex[s->n_preferred_kex++] =
5546 &ssh_diffiehellman_group14;
5547 break;
5548 case KEX_DHGROUP1:
5549 s->preferred_kex[s->n_preferred_kex++] =
5550 &ssh_diffiehellman_group1;
5551 break;
fae1a71b 5552 case KEX_RSA:
5553 s->preferred_kex[s->n_preferred_kex++] =
5554 &ssh_rsa_kex;
5555 break;
754c0df9 5556 case KEX_WARN:
83e7d008 5557 /* Flag for later. Don't bother if it's the last in
5558 * the list. */
5559 if (i < KEX_MAX - 1) {
5560 s->preferred_kex[s->n_preferred_kex++] = NULL;
5561 }
5562 break;
5563 }
5564 }
83e7d008 5565
83e7d008 5566 /*
51470298 5567 * Set up the preferred ciphers. (NULL => warn below here)
5568 */
5569 s->n_preferred_ciphers = 0;
5570 for (i = 0; i < CIPHER_MAX; i++) {
4a693cfc 5571 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
51470298 5572 case CIPHER_BLOWFISH:
5573 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5574 break;
5575 case CIPHER_DES:
4a693cfc 5576 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
51470298 5577 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5578 }
5579 break;
5580 case CIPHER_3DES:
5581 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5582 break;
5583 case CIPHER_AES:
5584 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5585 break;
a2add208 5586 case CIPHER_ARCFOUR:
5587 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5588 break;
51470298 5589 case CIPHER_WARN:
5590 /* Flag for later. Don't bother if it's the last in
5591 * the list. */
5592 if (i < CIPHER_MAX - 1) {
5593 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5594 }
5595 break;
ca20bfcf 5596 }
ca20bfcf 5597 }
7591b9ff 5598
e13bba36 5599 /*
5600 * Set up preferred compression.
5601 */
4a693cfc 5602 if (conf_get_int(ssh->conf, CONF_compression))
e13bba36 5603 s->preferred_comp = &ssh_zlib;
5604 else
5605 s->preferred_comp = &ssh_comp_none;
51470298 5606
5607 /*
590f6a5f 5608 * Enable queueing of outgoing auth- or connection-layer
5609 * packets while we are in the middle of a key exchange.
5610 */
5611 ssh->queueing = TRUE;
5612
5613 /*
9442dd57 5614 * Flag that KEX is in progress.
5615 */
5616 ssh->kex_in_progress = TRUE;
5617
5618 /*
51470298 5619 * Construct and send our key exchange packet.
5620 */
ff3187f6 5621 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5622 for (i = 0; i < 16; i++)
ff3187f6 5623 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5624 /* List key exchange algorithms. */
ff3187f6 5625 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5626 commalist_started = 0;
5627 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5628 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5629 if (!k) continue; /* warning flag */
34557659 5630 for (j = 0; j < k->nkexes; j++) {
5631 if (commalist_started)
5632 ssh2_pkt_addstring_str(s->pktout, ",");
5633 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5634 commalist_started = 1;
5635 }
32874aea 5636 }
51470298 5637 /* List server host key algorithms. */
ff3187f6 5638 ssh2_pkt_addstring_start(s->pktout);
51470298 5639 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5640 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5641 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5642 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5643 }
51470298 5644 /* List client->server encryption algorithms. */
ff3187f6 5645 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5646 commalist_started = 0;
51470298 5647 for (i = 0; i < s->n_preferred_ciphers; i++) {
5648 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5649 if (!c) continue; /* warning flag */
5650 for (j = 0; j < c->nciphers; j++) {
83e7d008 5651 if (commalist_started)
ff3187f6 5652 ssh2_pkt_addstring_str(s->pktout, ",");
5653 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5654 commalist_started = 1;
51470298 5655 }
5656 }
5657 /* List server->client encryption algorithms. */
ff3187f6 5658 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5659 commalist_started = 0;
51470298 5660 for (i = 0; i < s->n_preferred_ciphers; i++) {
5661 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5662 if (!c) continue; /* warning flag */
5663 for (j = 0; j < c->nciphers; j++) {
83e7d008 5664 if (commalist_started)
ff3187f6 5665 ssh2_pkt_addstring_str(s->pktout, ",");
5666 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5667 commalist_started = 1;
51470298 5668 }
5669 }
5670 /* List client->server MAC algorithms. */
ff3187f6 5671 ssh2_pkt_addstring_start(s->pktout);
51470298 5672 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5673 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5674 if (i < s->nmacs - 1)
ff3187f6 5675 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5676 }
5677 /* List server->client MAC algorithms. */
ff3187f6 5678 ssh2_pkt_addstring_start(s->pktout);
51470298 5679 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5680 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5681 if (i < s->nmacs - 1)
ff3187f6 5682 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5683 }
ab18ccff 5684 /* List client->server compression algorithms,
5685 * then server->client compression algorithms. (We use the
5686 * same set twice.) */
5687 for (j = 0; j < 2; j++) {
5688 ssh2_pkt_addstring_start(s->pktout);
5689 assert(lenof(compressions) > 1);
5690 /* Prefer non-delayed versions */
5691 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5692 /* We don't even list delayed versions of algorithms until
5693 * they're allowed to be used, to avoid a race. See the end of
5694 * this function. */
5695 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ff3187f6 5696 ssh2_pkt_addstring_str(s->pktout, ",");
ab18ccff 5697 ssh2_pkt_addstring_str(s->pktout,
5698 s->preferred_comp->delayed_name);
f6e0abe2 5699 }
ab18ccff 5700 for (i = 0; i < lenof(compressions); i++) {
5701 const struct ssh_compress *c = compressions[i];
5702 if (c != s->preferred_comp) {
5703 ssh2_pkt_addstring_str(s->pktout, ",");
5704 ssh2_pkt_addstring_str(s->pktout, c->name);
5705 if (s->userauth_succeeded && c->delayed_name) {
5706 ssh2_pkt_addstring_str(s->pktout, ",");
5707 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5708 }
5709 }
f6e0abe2 5710 }
51470298 5711 }
5712 /* List client->server languages. Empty list. */
ff3187f6 5713 ssh2_pkt_addstring_start(s->pktout);
51470298 5714 /* List server->client languages. Empty list. */
ff3187f6 5715 ssh2_pkt_addstring_start(s->pktout);
51470298 5716 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5717 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5718 /* Reserved. */
ff3187f6 5719 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5720 }
0db56f73 5721
3dc9a6a7 5722 s->our_kexinitlen = s->pktout->length - 5;
5723 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5724 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5725
590f6a5f 5726 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5727
ff3187f6 5728 if (!pktin)
5729 crWaitUntil(pktin);
e5574168 5730
5731 /*
5732 * Now examine the other side's KEXINIT to see what we're up
5733 * to.
5734 */
51470298 5735 {
4763c1c2 5736 char *str, *preferred;
3d9449a1 5737 int i, j, len;
51470298 5738
ff3187f6 5739 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5740 bombout(("expected key exchange packet from server"));
7ffdbc1a 5741 crStop(0);
32874aea 5742 }
51470298 5743 ssh->kex = NULL;
5744 ssh->hostkey = NULL;
5745 s->cscipher_tobe = NULL;
5746 s->sccipher_tobe = NULL;
5747 s->csmac_tobe = NULL;
5748 s->scmac_tobe = NULL;
5749 s->cscomp_tobe = NULL;
5750 s->sccomp_tobe = NULL;
4763c1c2 5751 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5752
ff3187f6 5753 pktin->savedpos += 16; /* skip garbage cookie */
5754 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5755
5756 preferred = NULL;
83e7d008 5757 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5758 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5759 if (!k) {
4763c1c2 5760 s->warn_kex = TRUE;
5761 } else {
34557659 5762 for (j = 0; j < k->nkexes; j++) {
5763 if (!preferred) preferred = k->list[j]->name;
5764 if (in_commasep_string(k->list[j]->name, str, len)) {
5765 ssh->kex = k->list[j];
5766 break;
5767 }
5768 }
83e7d008 5769 }
4763c1c2 5770 if (ssh->kex)
51470298 5771 break;
32874aea 5772 }
83e7d008 5773 if (!ssh->kex) {
5774 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5775 str ? str : "(null)"));
5776 crStop(0);
5777 }
b59743d5 5778 /*
5779 * Note that the server's guess is considered wrong if it doesn't match
5780 * the first algorithm in our list, even if it's still the algorithm
5781 * we end up using.
5782 */
4763c1c2 5783 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5784 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5785 for (i = 0; i < lenof(hostkey_algs); i++) {
5786 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5787 ssh->hostkey = hostkey_algs[i];
5788 break;
5789 }
5790 }
fc40b431 5791 if (!ssh->hostkey) {
5792 bombout(("Couldn't agree a host key algorithm (available: %s)",
5793 str ? str : "(null)"));
5794 crStop(0);
5795 }
5796
3d9449a1 5797 s->guessok = s->guessok &&
b59743d5 5798 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5799 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5800 for (i = 0; i < s->n_preferred_ciphers; i++) {
5801 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5802 if (!c) {
4763c1c2 5803 s->warn_cscipher = TRUE;
51470298 5804 } else {
5805 for (j = 0; j < c->nciphers; j++) {
5806 if (in_commasep_string(c->list[j]->name, str, len)) {
5807 s->cscipher_tobe = c->list[j];
5808 break;
5809 }
ca20bfcf 5810 }
32874aea 5811 }
4763c1c2 5812 if (s->cscipher_tobe)
51470298 5813 break;
32874aea 5814 }
51470298 5815 if (!s->cscipher_tobe) {
6b5cf8b4 5816 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5817 str ? str : "(null)"));
7ffdbc1a 5818 crStop(0);
ca20bfcf 5819 }
0ef8f407 5820
ff3187f6 5821 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5822 for (i = 0; i < s->n_preferred_ciphers; i++) {
5823 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5824 if (!c) {
4763c1c2 5825 s->warn_sccipher = TRUE;
51470298 5826 } else {
5827 for (j = 0; j < c->nciphers; j++) {
5828 if (in_commasep_string(c->list[j]->name, str, len)) {
5829 s->sccipher_tobe = c->list[j];
5830 break;
5831 }
ca20bfcf 5832 }
32874aea 5833 }
4763c1c2 5834 if (s->sccipher_tobe)
51470298 5835 break;
32874aea 5836 }
51470298 5837 if (!s->sccipher_tobe) {
6b5cf8b4 5838 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5839 str ? str : "(null)"));
7ffdbc1a 5840 crStop(0);
ca20bfcf 5841 }
0ef8f407 5842
ff3187f6 5843 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5844 for (i = 0; i < s->nmacs; i++) {
5845 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5846 s->csmac_tobe = s->maclist[i];
5847 break;
5848 }
32874aea 5849 }
ff3187f6 5850 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5851 for (i = 0; i < s->nmacs; i++) {
5852 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5853 s->scmac_tobe = s->maclist[i];
5854 break;
5855 }
32874aea 5856 }
ff3187f6 5857 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5858 for (i = 0; i < lenof(compressions) + 1; i++) {
5859 const struct ssh_compress *c =
5860 i == 0 ? s->preferred_comp : compressions[i - 1];
5861 if (in_commasep_string(c->name, str, len)) {
5862 s->cscomp_tobe = c;
5863 break;
ab18ccff 5864 } else if (in_commasep_string(c->delayed_name, str, len)) {
5865 if (s->userauth_succeeded) {
5866 s->cscomp_tobe = c;
5867 break;
5868 } else {
5869 s->pending_compression = TRUE; /* try this later */
5870 }
51470298 5871 }
32874aea 5872 }
ff3187f6 5873 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5874 for (i = 0; i < lenof(compressions) + 1; i++) {
5875 const struct ssh_compress *c =
5876 i == 0 ? s->preferred_comp : compressions[i - 1];
5877 if (in_commasep_string(c->name, str, len)) {
5878 s->sccomp_tobe = c;
5879 break;
ab18ccff 5880 } else if (in_commasep_string(c->delayed_name, str, len)) {
5881 if (s->userauth_succeeded) {
5882 s->sccomp_tobe = c;
5883 break;
5884 } else {
5885 s->pending_compression = TRUE; /* try this later */
5886 }
51470298 5887 }
32874aea 5888 }
ab18ccff 5889 if (s->pending_compression) {
5890 logevent("Server supports delayed compression; "
5891 "will try this later");
5892 }
b59743d5 5893 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5894 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5895 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5896
5897 if (s->warn_kex) {
5898 ssh_set_frozen(ssh, 1);
5899 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5900 ssh->kex->name,
5901 ssh_dialog_callback, ssh);
5902 if (s->dlgret < 0) {
5903 do {
5904 crReturn(0);
5905 if (pktin) {
5906 bombout(("Unexpected data from server while"
5907 " waiting for user response"));
5908 crStop(0);
5909 }
5910 } while (pktin || inlen > 0);
5911 s->dlgret = ssh->user_response;
5912 }
5913 ssh_set_frozen(ssh, 0);
5914 if (s->dlgret == 0) {
9e296bfa 5915 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5916 0, TRUE);
a5a6f839 5917 crStop(0);
4763c1c2 5918 }
5919 }
5920
5921 if (s->warn_cscipher) {
5922 ssh_set_frozen(ssh, 1);
5923 s->dlgret = askalg(ssh->frontend,
5924 "client-to-server cipher",
5925 s->cscipher_tobe->name,
5926 ssh_dialog_callback, ssh);
5927 if (s->dlgret < 0) {
5928 do {
5929 crReturn(0);
5930 if (pktin) {
5931 bombout(("Unexpected data from server while"
5932 " waiting for user response"));
5933 crStop(0);
5934 }
5935 } while (pktin || inlen > 0);
5936 s->dlgret = ssh->user_response;
5937 }
5938 ssh_set_frozen(ssh, 0);
5939 if (s->dlgret == 0) {
9e296bfa 5940 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5941 0, TRUE);
a5a6f839 5942 crStop(0);
4763c1c2 5943 }
5944 }
5945
5946 if (s->warn_sccipher) {
5947 ssh_set_frozen(ssh, 1);
5948 s->dlgret = askalg(ssh->frontend,
5949 "server-to-client cipher",
5950 s->sccipher_tobe->name,
5951 ssh_dialog_callback, ssh);
5952 if (s->dlgret < 0) {
5953 do {
5954 crReturn(0);
5955 if (pktin) {
5956 bombout(("Unexpected data from server while"
5957 " waiting for user response"));
5958 crStop(0);
5959 }
5960 } while (pktin || inlen > 0);
5961 s->dlgret = ssh->user_response;
5962 }
5963 ssh_set_frozen(ssh, 0);
5964 if (s->dlgret == 0) {
9e296bfa 5965 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5966 0, TRUE);
a5a6f839 5967 crStop(0);
4763c1c2 5968 }
5969 }
5970
b672f405 5971 ssh->exhash = ssh->kex->hash->init();
5972 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5973 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5974 hash_string(ssh->kex->hash, ssh->exhash,
5975 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5976 sfree(s->our_kexinit);
5977 if (pktin->length > 5)
b672f405 5978 hash_string(ssh->kex->hash, ssh->exhash,
5979 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5980
4763c1c2 5981 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5982 crWaitUntil(pktin); /* Ignore packet */
e5574168 5983 }
e5574168 5984
fae1a71b 5985 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 5986 /*
5987 * Work out the number of bits of key we will need from the
5988 * key exchange. We start with the maximum key length of
5989 * either cipher...
5990 */
5991 {
5992 int csbits, scbits;
5993
5994 csbits = s->cscipher_tobe->keylen;
5995 scbits = s->sccipher_tobe->keylen;
5996 s->nbits = (csbits > scbits ? csbits : scbits);
5997 }
5998 /* The keys only have hlen-bit entropy, since they're based on
5999 * a hash. So cap the key size at hlen bits. */
6000 if (s->nbits > ssh->kex->hash->hlen * 8)
6001 s->nbits = ssh->kex->hash->hlen * 8;
6002
6003 /*
6004 * If we're doing Diffie-Hellman group exchange, start by
6005 * requesting a group.
6006 */
6007 if (!ssh->kex->pdata) {
6008 logevent("Doing Diffie-Hellman group exchange");
acab36bc 6009 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 6010 /*
6011 * Work out how big a DH group we will need to allow that
6012 * much data.
6013 */
6014 s->pbits = 512 << ((s->nbits - 1) / 64);
6015 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6016 ssh2_pkt_adduint32(s->pktout, s->pbits);
6017 ssh2_pkt_send_noqueue(ssh, s->pktout);
6018
6019 crWaitUntil(pktin);
6020 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6021 bombout(("expected key exchange group packet from server"));
6022 crStop(0);
6023 }
6024 s->p = ssh2_pkt_getmp(pktin);
6025 s->g = ssh2_pkt_getmp(pktin);
6026 if (!s->p || !s->g) {
6027 bombout(("unable to read mp-ints from incoming group packet"));
6028 crStop(0);
6029 }
6030 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6031 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6032 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6033 } else {
acab36bc 6034 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 6035 ssh->kex_ctx = dh_setup_group(ssh->kex);
6036 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6037 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6038 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6039 ssh->kex->groupname);
6040 }
e5574168 6041
30774ba3 6042 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6043 ssh->kex->hash->text_name);
6044 /*
6045 * Now generate and send e for Diffie-Hellman.
6046 */
6047 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6048 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6049 s->pktout = ssh2_pkt_init(s->kex_init_value);
6050 ssh2_pkt_addmp(s->pktout, s->e);
6051 ssh2_pkt_send_noqueue(ssh, s->pktout);
6052
6053 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6054 crWaitUntil(pktin);
6055 if (pktin->type != s->kex_reply_value) {
6056 bombout(("expected key exchange reply packet from server"));
6057 crStop(0);
6058 }
6059 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6060 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6061 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6062 s->f = ssh2_pkt_getmp(pktin);
6063 if (!s->f) {
6064 bombout(("unable to parse key exchange reply packet"));
6065 crStop(0);
6066 }
6067 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 6068
30774ba3 6069 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 6070
30774ba3 6071 /* We assume everything from now on will be quick, and it might
6072 * involve user interaction. */
6073 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 6074
30774ba3 6075 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6076 if (!ssh->kex->pdata) {
6077 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6078 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6079 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6080 }
6081 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6082 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6083
6084 dh_cleanup(ssh->kex_ctx);
6085 freebn(s->f);
6086 if (!ssh->kex->pdata) {
6087 freebn(s->g);
6088 freebn(s->p);
6089 }
fae1a71b 6090 } else {
6091 logeventf(ssh, "Doing RSA key exchange with hash %s",
6092 ssh->kex->hash->text_name);
acab36bc 6093 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 6094 /*
6095 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6096 * from the server.
6097 */
6098 crWaitUntil(pktin);
6099 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6100 bombout(("expected RSA public key packet from server"));
6101 crStop(0);
6102 }
6103
6104 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6105 hash_string(ssh->kex->hash, ssh->exhash,
6106 s->hostkeydata, s->hostkeylen);
6107 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6108
6109 {
6110 char *keydata;
6111 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6112 s->rsakeydata = snewn(s->rsakeylen, char);
6113 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6114 }
6115
6116 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6117 if (!s->rsakey) {
6118 sfree(s->rsakeydata);
6119 bombout(("unable to parse RSA public key from server"));
6120 crStop(0);
6121 }
6122
6123 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6124
6125 /*
6126 * Next, set up a shared secret K, of precisely KLEN -
6127 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6128 * RSA key modulus and HLEN is the bit length of the hash
6129 * we're using.
6130 */
6131 {
6132 int klen = ssh_rsakex_klen(s->rsakey);
6133 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6134 int i, byte = 0;
6135 unsigned char *kstr1, *kstr2, *outstr;
6136 int kstr1len, kstr2len, outstrlen;
6137
6138 s->K = bn_power_2(nbits - 1);
6139
6140 for (i = 0; i < nbits; i++) {
6141 if ((i & 7) == 0) {
6142 byte = random_byte();
6143 }
6144 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6145 }
6146
6147 /*
6148 * Encode this as an mpint.
6149 */
6150 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6151 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6152 PUT_32BIT(kstr2, kstr1len);
6153 memcpy(kstr2 + 4, kstr1, kstr1len);
6154
6155 /*
6156 * Encrypt it with the given RSA key.
6157 */
6158 outstrlen = (klen + 7) / 8;
6159 outstr = snewn(outstrlen, unsigned char);
6160 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6161 outstr, outstrlen, s->rsakey);
6162
6163 /*
6164 * And send it off in a return packet.
6165 */
6166 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6167 ssh2_pkt_addstring_start(s->pktout);
7108a872 6168 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 6169 ssh2_pkt_send_noqueue(ssh, s->pktout);
6170
6171 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6172
6173 sfree(kstr2);
6174 sfree(kstr1);
6175 sfree(outstr);
6176 }
6177
6178 ssh_rsakex_freekey(s->rsakey);
6179
6180 crWaitUntil(pktin);
6181 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6182 sfree(s->rsakeydata);
6183 bombout(("expected signature packet from server"));
6184 crStop(0);
6185 }
6186
6187 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6188
6189 sfree(s->rsakeydata);
6190 }
6191
b672f405 6192 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6193 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6194 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 6195
fabd1805 6196 ssh->kex_ctx = NULL;
3709bfe9 6197
7cca0d81 6198#if 0
765c4200 6199 debug(("Exchange hash is:\n"));
b672f405 6200 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 6201#endif
6202
51470298 6203 if (!s->hkey ||
6204 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 6205 (char *)s->exchange_hash,
6206 ssh->kex->hash->hlen)) {
6b5cf8b4 6207 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 6208 crStop(0);
8d5de777 6209 }
e5574168 6210
6211 /*
7cca0d81 6212 * Authenticate remote host: verify host key. (We've already
6213 * checked the signature of the exchange hash.)
e5574168 6214 */
51470298 6215 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6216 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 6217 ssh_set_frozen(ssh, 1);
6218 s->dlgret = verify_ssh_host_key(ssh->frontend,
6219 ssh->savedhost, ssh->savedport,
6220 ssh->hostkey->keytype, s->keystr,
6221 s->fingerprint,
6222 ssh_dialog_callback, ssh);
6223 if (s->dlgret < 0) {
6224 do {
6225 crReturn(0);
6226 if (pktin) {
6227 bombout(("Unexpected data from server while waiting"
6228 " for user host key response"));
6229 crStop(0);
6230 }
6231 } while (pktin || inlen > 0);
6232 s->dlgret = ssh->user_response;
6233 }
6234 ssh_set_frozen(ssh, 0);
6235 if (s->dlgret == 0) {
9e296bfa 6236 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6237 0, TRUE);
3d9449a1 6238 crStop(0);
6239 }
e13bba36 6240 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 6241 logevent("Host key fingerprint is:");
51470298 6242 logevent(s->fingerprint);
5e0d7cb8 6243 }
51470298 6244 sfree(s->fingerprint);
6245 sfree(s->keystr);
6246 ssh->hostkey->freekey(s->hkey);
d39f364a 6247
6248 /*
9442dd57 6249 * The exchange hash from the very first key exchange is also
6250 * the session id, used in session key construction and
6251 * authentication.
6252 */
e13bba36 6253 if (!s->got_session_id) {
b672f405 6254 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 6255 memcpy(ssh->v2_session_id, s->exchange_hash,
6256 sizeof(s->exchange_hash));
b672f405 6257 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 6258 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 6259 s->got_session_id = TRUE;
6260 }
9442dd57 6261
6262 /*
7cca0d81 6263 * Send SSH2_MSG_NEWKEYS.
d39f364a 6264 */
ff3187f6 6265 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 6266 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 6267 ssh->outgoing_data_size = 0; /* start counting from here */
6268
6269 /*
6270 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 6271 * client-to-server session keys.
9442dd57 6272 */
6273 if (ssh->cs_cipher_ctx)
6274 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6275 ssh->cscipher = s->cscipher_tobe;
6276 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6277
6278 if (ssh->cs_mac_ctx)
6279 ssh->csmac->free_context(ssh->cs_mac_ctx);
6280 ssh->csmac = s->csmac_tobe;
6281 ssh->cs_mac_ctx = ssh->csmac->make_context();
6282
6283 if (ssh->cs_comp_ctx)
6284 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6285 ssh->cscomp = s->cscomp_tobe;
6286 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6287
6288 /*
6289 * Set IVs on client-to-server keys. Here we use the exchange
6290 * hash from the _first_ key exchange.
6291 */
6292 {
754c0df9 6293 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6294 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6295 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 6296 assert((ssh->cscipher->keylen+7) / 8 <=
6297 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6298 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 6299 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 6300 assert(ssh->cscipher->blksize <=
6301 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6302 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 6303 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 6304 assert(ssh->csmac->len <=
6305 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6306 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
dfb88efd 6307 smemclr(keyspace, sizeof(keyspace));
9442dd57 6308 }
6309
6310 logeventf(ssh, "Initialised %.200s client->server encryption",
6311 ssh->cscipher->text_name);
6312 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6313 ssh->csmac->text_name);
6314 if (ssh->cscomp->text_name)
6315 logeventf(ssh, "Initialised %s compression",
6316 ssh->cscomp->text_name);
590f6a5f 6317
6318 /*
6319 * Now our end of the key exchange is complete, we can send all
6320 * our queued higher-layer packets.
6321 */
6322 ssh->queueing = FALSE;
6323 ssh2_pkt_queuesend(ssh);
d39f364a 6324
6325 /*
8406eaf9 6326 * Expect SSH2_MSG_NEWKEYS from server.
6327 */
ff3187f6 6328 crWaitUntil(pktin);
6329 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 6330 bombout(("expected new-keys packet from server"));
7ffdbc1a 6331 crStop(0);
8406eaf9 6332 }
9442dd57 6333 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 6334
6335 /*
9442dd57 6336 * We've seen server NEWKEYS, so create and initialise
6337 * server-to-client session keys.
d39f364a 6338 */
371e569c 6339 if (ssh->sc_cipher_ctx)
6340 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6341 ssh->sccipher = s->sccipher_tobe;
371e569c 6342 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6343
e0e1a00d 6344 if (ssh->sc_mac_ctx)
6345 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6346 ssh->scmac = s->scmac_tobe;
e0e1a00d 6347 ssh->sc_mac_ctx = ssh->scmac->make_context();
6348
5366aed8 6349 if (ssh->sc_comp_ctx)
6350 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6351 ssh->sccomp = s->sccomp_tobe;
5366aed8 6352 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6353
d39f364a 6354 /*
9442dd57 6355 * Set IVs on server-to-client keys. Here we use the exchange
6356 * hash from the _first_ key exchange.
d39f364a 6357 */
51470298 6358 {
754c0df9 6359 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6360 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6361 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6362 assert((ssh->sccipher->keylen+7) / 8 <=
6363 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6364 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6365 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6366 assert(ssh->sccipher->blksize <=
6367 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6368 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6369 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6370 assert(ssh->scmac->len <=
6371 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6372 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
dfb88efd 6373 smemclr(keyspace, sizeof(keyspace));
51470298 6374 }
57356d63 6375 logeventf(ssh, "Initialised %.200s server->client encryption",
6376 ssh->sccipher->text_name);
6c135243 6377 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6378 ssh->scmac->text_name);
57356d63 6379 if (ssh->sccomp->text_name)
6380 logeventf(ssh, "Initialised %s decompression",
6381 ssh->sccomp->text_name);
9442dd57 6382
6383 /*
fae1a71b 6384 * Free shared secret.
9442dd57 6385 */
679539d7 6386 freebn(s->K);
d39f364a 6387
033b4cef 6388 /*
e13bba36 6389 * Key exchange is over. Loop straight back round if we have a
6390 * deferred rekey reason.
6391 */
6392 if (ssh->deferred_rekey_reason) {
6393 logevent(ssh->deferred_rekey_reason);
6394 pktin = NULL;
6395 ssh->deferred_rekey_reason = NULL;
6396 goto begin_key_exchange;
6397 }
6398
6399 /*
6400 * Otherwise, schedule a timer for our next rekey.
9442dd57 6401 */
6402 ssh->kex_in_progress = FALSE;
e6c1536e 6403 ssh->last_rekey = GETTICKCOUNT();
4a693cfc 6404 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6405 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
d57f70af 6406 ssh2_timer, ssh);
e13bba36 6407
9442dd57 6408 /*
0db56f73 6409 * If this is the first key exchange phase, we must pass the
6410 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6411 * wants to see it but because it will need time to initialise
6412 * itself before it sees an actual packet. In subsequent key
6413 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6414 * it would only confuse the layer above.
6415 */
e13bba36 6416 if (s->activated_authconn) {
0e3607ed 6417 crReturn(0);
0db56f73 6418 }
e13bba36 6419 s->activated_authconn = TRUE;
0db56f73 6420
6421 /*
7cca0d81 6422 * Now we're encrypting. Begin returning 1 to the protocol main
6423 * function so that other things can run on top of the
6424 * transport. If we ever see a KEXINIT, we must go back to the
6425 * start.
9442dd57 6426 *
6427 * We _also_ go back to the start if we see pktin==NULL and
ab18ccff 6428 * inlen negative, because this is a special signal meaning
9442dd57 6429 * `initiate client-driven rekey', and `in' contains a message
6430 * giving the reason for the rekey.
ab18ccff 6431 *
6432 * inlen==-1 means always initiate a rekey;
6433 * inlen==-2 means that userauth has completed successfully and
6434 * we should consider rekeying (for delayed compression).
033b4cef 6435 */
9442dd57 6436 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
ab18ccff 6437 (!pktin && inlen < 0))) {
f382c87d 6438 wait_for_rekey:
32874aea 6439 crReturn(1);
e96adf72 6440 }
9442dd57 6441 if (pktin) {
6442 logevent("Server initiated key re-exchange");
6443 } else {
ab18ccff 6444 if (inlen == -2) {
6445 /*
6446 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6447 * delayed compression, if it's available.
6448 *
6449 * draft-miller-secsh-compression-delayed-00 says that you
6450 * negotiate delayed compression in the first key exchange, and
6451 * both sides start compressing when the server has sent
6452 * USERAUTH_SUCCESS. This has a race condition -- the server
6453 * can't know when the client has seen it, and thus which incoming
6454 * packets it should treat as compressed.
6455 *
6456 * Instead, we do the initial key exchange without offering the
6457 * delayed methods, but note if the server offers them; when we
6458 * get here, if a delayed method was available that was higher
6459 * on our list than what we got, we initiate a rekey in which we
6460 * _do_ list the delayed methods (and hopefully get it as a
6461 * result). Subsequent rekeys will do the same.
6462 */
6463 assert(!s->userauth_succeeded); /* should only happen once */
6464 s->userauth_succeeded = TRUE;
6465 if (!s->pending_compression)
6466 /* Can't see any point rekeying. */
6467 goto wait_for_rekey; /* this is utterly horrid */
6468 /* else fall through to rekey... */
6469 s->pending_compression = FALSE;
6470 }
f382c87d 6471 /*
ab18ccff 6472 * Now we've decided to rekey.
6473 *
f382c87d 6474 * Special case: if the server bug is set that doesn't
6475 * allow rekeying, we give a different log message and
6476 * continue waiting. (If such a server _initiates_ a rekey,
6477 * we process it anyway!)
6478 */
6479 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6480 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6481 (char *)in);
6482 /* Reset the counters, so that at least this message doesn't
6483 * hit the event log _too_ often. */
6484 ssh->outgoing_data_size = 0;
6485 ssh->incoming_data_size = 0;
4a693cfc 6486 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
f382c87d 6487 ssh->next_rekey =
4a693cfc 6488 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
f382c87d 6489 ssh2_timer, ssh);
6490 }
ab18ccff 6491 goto wait_for_rekey; /* this is still utterly horrid */
f382c87d 6492 } else {
6493 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6494 }
9442dd57 6495 }
7cca0d81 6496 goto begin_key_exchange;
e5574168 6497
6498 crFinish(1);
6499}
6500
7cca0d81 6501/*
2e85c969 6502 * Add data to an SSH-2 channel output buffer.
783415f8 6503 */
32874aea 6504static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6505 int len)
6506{
5471d09a 6507 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6508}
6509
6510/*
2e85c969 6511 * Attempt to send data on an SSH-2 channel.
783415f8 6512 */
5471d09a 6513static int ssh2_try_send(struct ssh_channel *c)
32874aea 6514{
51470298 6515 Ssh ssh = c->ssh;
ff3187f6 6516 struct Packet *pktout;
bc06669b 6517 int ret;
51470298 6518
5471d09a 6519 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6520 int len;
6521 void *data;
6522 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6523 if ((unsigned)len > c->v.v2.remwindow)
6524 len = c->v.v2.remwindow;
6525 if ((unsigned)len > c->v.v2.remmaxpkt)
6526 len = c->v.v2.remmaxpkt;
ff3187f6 6527 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6528 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6529 ssh2_pkt_addstring_start(pktout);
a2724fba 6530 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6531 ssh2_pkt_addstring_data(pktout, data, len);
6532 end_log_omission(ssh, pktout);
6533 ssh2_pkt_send(ssh, pktout);
5471d09a 6534 bufchain_consume(&c->v.v2.outbuffer, len);
6535 c->v.v2.remwindow -= len;
6536 }
6537
6538 /*
6539 * After having sent as much data as we can, return the amount
6540 * still buffered.
6541 */
bc06669b 6542 ret = bufchain_size(&c->v.v2.outbuffer);
6543
6544 /*
6545 * And if there's no data pending but we need to send an EOF, send
6546 * it.
6547 */
6548 if (!ret && c->pending_eof)
6549 ssh_channel_try_eof(c);
6550
6551 return ret;
5471d09a 6552}
6553
78280721 6554static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
1bfc7e93 6555{
6556 int bufsize;
bc06669b 6557 if (c->closes & CLOSES_SENT_EOF)
6558 return; /* don't send on channels we've EOFed */
1bfc7e93 6559 bufsize = ssh2_try_send(c);
6560 if (bufsize == 0) {
6561 switch (c->type) {
6562 case CHAN_MAINSESSION:
6563 /* stdin need not receive an unthrottle
6564 * notification since it will be polled */
6565 break;
6566 case CHAN_X11:
6567 x11_unthrottle(c->u.x11.s);
6568 break;
6569 case CHAN_AGENT:
6570 /* agent sockets are request/response and need no
6571 * buffer management */
6572 break;
6573 case CHAN_SOCKDATA:
6574 pfd_unthrottle(c->u.pfd.s);
6575 break;
6576 }
6577 }
6578}
6579
5471d09a 6580/*
94bdfe40 6581 * Set up most of a new ssh_channel for SSH-2.
6582 */
6583static void ssh2_channel_init(struct ssh_channel *c)
6584{
6585 Ssh ssh = c->ssh;
6586 c->localid = alloc_channel_id(ssh);
6587 c->closes = 0;
bc06669b 6588 c->pending_eof = FALSE;
94bdfe40 6589 c->throttling_conn = FALSE;
6590 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
4a693cfc 6591 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
94bdfe40 6592 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6593 c->v.v2.throttle_state = UNTHROTTLED;
6594 bufchain_init(&c->v.v2.outbuffer);
6595}
6596
6597/*
2e85c969 6598 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6599 */
9fca3f8c 6600static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6601{
51470298 6602 Ssh ssh = c->ssh;
6603
6b69f42e 6604 /*
bc06669b 6605 * Never send WINDOW_ADJUST for a channel that the remote side has
6606 * already sent EOF on; there's no point, since it won't be
beff003a 6607 * sending any more data anyway. Ditto if _we've_ already sent
6608 * CLOSE.
6b69f42e 6609 */
beff003a 6610 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6b69f42e 6611 return;
6612
d252310a 6613 /*
c9739dba 6614 * If the remote end has a habit of ignoring maxpkt, limit the
6615 * window so that it has no choice (assuming it doesn't ignore the
6616 * window as well).
6617 */
6618 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6619 newwin = OUR_V2_MAXPKT;
c9739dba 6620
6621 /*
d252310a 6622 * Only send a WINDOW_ADJUST if there's significantly more window
6623 * available than the other end thinks there is. This saves us
6624 * sending a WINDOW_ADJUST for every character in a shell session.
6625 *
6626 * "Significant" is arbitrarily defined as half the window size.
6627 */
3361b80a 6628 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6629 struct Packet *pktout;
0e443c99 6630 struct winadj *wa;
ff3187f6 6631
0e443c99 6632 /*
6633 * In order to keep track of how much window the client
6634 * actually has available, we'd like it to acknowledge each
6635 * WINDOW_ADJUST. We can't do that directly, so we accompany
6636 * it with a CHANNEL_REQUEST that has to be acknowledged.
6637 *
6638 * This is only necessary if we're opening the window wide.
6639 * If we're not, then throughput is being constrained by
6640 * something other than the maximum window size anyway.
6641 *
6642 * We also only send this if the main channel has finished its
6643 * initial CHANNEL_REQUESTs and installed the default
6644 * CHANNEL_FAILURE handler, so as not to risk giving it
6645 * unexpected CHANNEL_FAILUREs.
6646 */
6647 if (newwin == c->v.v2.locmaxwin &&
2e0aae4f 6648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] &&
6649 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
0e443c99 6650 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6651 ssh2_pkt_adduint32(pktout, c->remoteid);
6652 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6653 ssh2_pkt_addbool(pktout, TRUE);
6654 ssh2_pkt_send(ssh, pktout);
6655
6656 /*
6657 * CHANNEL_FAILURE doesn't come with any indication of
6658 * what message caused it, so we have to keep track of the
6659 * outstanding CHANNEL_REQUESTs ourselves.
6660 */
6661 wa = snew(struct winadj);
6662 wa->size = newwin - c->v.v2.locwindow;
6663 wa->next = NULL;
6664 if (!c->v.v2.winadj_head)
6665 c->v.v2.winadj_head = wa;
6666 else
6667 c->v.v2.winadj_tail->next = wa;
6668 c->v.v2.winadj_tail = wa;
6669 if (c->v.v2.throttle_state != UNTHROTTLED)
6670 c->v.v2.throttle_state = UNTHROTTLING;
6671 } else {
6672 /* Pretend the WINDOW_ADJUST was acked immediately. */
6673 c->v.v2.remlocwin = newwin;
6674 c->v.v2.throttle_state = THROTTLED;
6675 }
ff3187f6 6676 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6677 ssh2_pkt_adduint32(pktout, c->remoteid);
6678 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6679 ssh2_pkt_send(ssh, pktout);
5471d09a 6680 c->v.v2.locwindow = newwin;
783415f8 6681 }
6682}
6683
e223b7c7 6684/*
6685 * Find the channel associated with a message. If there's no channel,
6686 * or it's not properly open, make a noise about it and return NULL.
6687 */
6688static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6689{
6690 unsigned localid = ssh_pkt_getuint32(pktin);
6691 struct ssh_channel *c;
6692
6693 c = find234(ssh->channels, &localid, ssh_channelfind);
6694 if (!c ||
6695 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6696 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6697 char *buf = dupprintf("Received %s for %s channel %u",
6698 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6699 pktin->type),
6700 c ? "half-open" : "nonexistent", localid);
6701 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6702 sfree(buf);
6703 return NULL;
6704 }
6705 return c;
6706}
6707
e030765f 6708static int ssh2_handle_winadj_response(struct ssh_channel *c)
6709{
6710 struct winadj *wa = c->v.v2.winadj_head;
6711 if (!wa)
6712 return FALSE;
6713 c->v.v2.winadj_head = wa->next;
6714 c->v.v2.remlocwin += wa->size;
6715 sfree(wa);
6716 /*
6717 * winadj messages are only sent when the window is fully open, so
6718 * if we get an ack of one, we know any pending unthrottle is
6719 * complete.
6720 */
6721 if (c->v.v2.throttle_state == UNTHROTTLING)
6722 c->v.v2.throttle_state = UNTHROTTLED;
997097db 6723 /*
6724 * We may now initiate channel-closing procedures, if that winadj
6725 * was the last thing outstanding before we send CHANNEL_CLOSE.
6726 */
6727 ssh2_channel_check_close(c);
e030765f 6728 return TRUE;
6729}
6730
837d6ba6 6731static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6732{
6733 /*
6734 * This should never get called. All channel requests are either
e030765f 6735 * sent with want_reply false, are sent before this handler gets
6736 * installed, or are "winadj@putty" requests, which servers should
6737 * never respond to with success.
6738 *
6739 * However, at least one server ("boks_sshd") is known to return
6740 * SUCCESS for channel requests it's never heard of, such as
6741 * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
6742 * for the sake of a quiet life, we handle it just the same as the
6743 * expected FAILURE.
837d6ba6 6744 */
6745 struct ssh_channel *c;
837d6ba6 6746
6747 c = ssh2_channel_msg(ssh, pktin);
6748 if (!c)
6749 return;
e030765f 6750 if (!ssh2_handle_winadj_response(c))
837d6ba6 6751 ssh_disconnect(ssh, NULL,
6752 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6753 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6754}
6755
0e443c99 6756static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6757{
6758 /*
6759 * The only time this should get called is for "winadj@putty"
6760 * messages sent above. All other channel requests are either
6761 * sent with want_reply false or are sent before this handler gets
6762 * installed.
6763 */
0e443c99 6764 struct ssh_channel *c;
0e443c99 6765
e223b7c7 6766 c = ssh2_channel_msg(ssh, pktin);
0e443c99 6767 if (!c)
e223b7c7 6768 return;
e030765f 6769 if (!ssh2_handle_winadj_response(c))
837d6ba6 6770 ssh_disconnect(ssh, NULL,
6771 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6772 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
0e443c99 6773}
6774
51df0ab5 6775static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6776{
b09eaa88 6777 struct ssh_channel *c;
e223b7c7 6778 c = ssh2_channel_msg(ssh, pktin);
6779 if (!c)
6780 return;
bc06669b 6781 if (!(c->closes & CLOSES_SENT_EOF)) {
b09eaa88 6782 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
78280721 6783 ssh2_try_send_and_unthrottle(ssh, c);
1bfc7e93 6784 }
b09eaa88 6785}
6786
51df0ab5 6787static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6788{
6789 char *data;
6d44acc9 6790 int length;
51df0ab5 6791 struct ssh_channel *c;
e223b7c7 6792 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 6793 if (!c)
e223b7c7 6794 return;
51df0ab5 6795 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6796 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6797 return; /* extended but not stderr */
6798 ssh_pkt_getstring(pktin, &data, &length);
6799 if (data) {
6800 int bufsize = 0;
6801 c->v.v2.locwindow -= length;
0e443c99 6802 c->v.v2.remlocwin -= length;
51df0ab5 6803 switch (c->type) {
6804 case CHAN_MAINSESSION:
6805 bufsize =
6806 from_backend(ssh->frontend, pktin->type ==
6807 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6808 data, length);
6809 break;
6810 case CHAN_X11:
6811 bufsize = x11_send(c->u.x11.s, data, length);
6812 break;
6813 case CHAN_SOCKDATA:
6814 bufsize = pfd_send(c->u.pfd.s, data, length);
6815 break;
6816 case CHAN_AGENT:
6817 while (length > 0) {
6818 if (c->u.a.lensofar < 4) {
62ddb51e 6819 unsigned int l = min(4 - c->u.a.lensofar,
6820 (unsigned)length);
51df0ab5 6821 memcpy(c->u.a.msglen + c->u.a.lensofar,
6822 data, l);
6823 data += l;
6824 length -= l;
6825 c->u.a.lensofar += l;
6826 }
6827 if (c->u.a.lensofar == 4) {
6828 c->u.a.totallen =
6829 4 + GET_32BIT(c->u.a.msglen);
6830 c->u.a.message = snewn(c->u.a.totallen,
6831 unsigned char);
6832 memcpy(c->u.a.message, c->u.a.msglen, 4);
6833 }
6834 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6835 unsigned int l =
51df0ab5 6836 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6837 (unsigned)length);
51df0ab5 6838 memcpy(c->u.a.message + c->u.a.lensofar,
6839 data, l);
6840 data += l;
6841 length -= l;
6842 c->u.a.lensofar += l;
6843 }
6844 if (c->u.a.lensofar == c->u.a.totallen) {
6845 void *reply;
6846 int replylen;
6847 if (agent_query(c->u.a.message,
6848 c->u.a.totallen,
6849 &reply, &replylen,
6850 ssh_agentf_callback, c))
6851 ssh_agentf_callback(c, reply, replylen);
6852 sfree(c->u.a.message);
bc06669b 6853 c->u.a.message = NULL;
51df0ab5 6854 c->u.a.lensofar = 0;
6855 }
6856 }
6857 bufsize = 0;
6858 break;
6859 }
6860 /*
0e443c99 6861 * If it looks like the remote end hit the end of its window,
6862 * and we didn't want it to do that, think about using a
6863 * larger window.
6864 */
6865 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6866 c->v.v2.locmaxwin < 0x40000000)
6867 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6868 /*
51df0ab5 6869 * If we are not buffering too much data,
6870 * enlarge the window again at the remote side.
467e064d 6871 * If we are buffering too much, we may still
6872 * need to adjust the window if the server's
6873 * sent excess data.
51df0ab5 6874 */
9b53e9b8 6875 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6876 c->v.v2.locmaxwin - bufsize : 0);
ff68564b 6877 /*
6878 * If we're either buffering way too much data, or if we're
6879 * buffering anything at all and we're in "simple" mode,
6880 * throttle the whole channel.
6881 */
6882 if ((bufsize > c->v.v2.locmaxwin ||
4a693cfc 6883 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
ff68564b 6884 !c->throttling_conn) {
6885 c->throttling_conn = 1;
6886 ssh_throttle_conn(ssh, +1);
6887 }
51df0ab5 6888 }
6889}
6890
bc06669b 6891static void ssh_channel_destroy(struct ssh_channel *c)
51df0ab5 6892{
bc06669b 6893 Ssh ssh = c->ssh;
51df0ab5 6894
bc06669b 6895 switch (c->type) {
6896 case CHAN_MAINSESSION:
6897 ssh->mainchan = NULL;
6898 update_specials_menu(ssh->frontend);
6899 break;
6900 case CHAN_X11:
6901 if (c->u.x11.s != NULL)
6902 x11_close(c->u.x11.s);
6903 logevent("Forwarded X11 connection terminated");
6904 break;
6905 case CHAN_AGENT:
6906 sfree(c->u.a.message);
6907 break;
6908 case CHAN_SOCKDATA:
6909 if (c->u.pfd.s != NULL)
6910 pfd_close(c->u.pfd.s);
6911 logevent("Forwarded port closed");
6912 break;
6913 }
6914
6915 del234(ssh->channels, c);
6916 if (ssh->version == 2)
6917 bufchain_clear(&c->v.v2.outbuffer);
6918 sfree(c);
6919
6920 /*
6921 * See if that was the last channel left open.
6922 * (This is only our termination condition if we're
6923 * not running in -N mode.)
6924 */
6925 if (ssh->version == 2 &&
6926 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
6927 count234(ssh->channels) == 0) {
6928 /*
6929 * We used to send SSH_MSG_DISCONNECT here,
6930 * because I'd believed that _every_ conforming
6931 * SSH-2 connection had to end with a disconnect
6932 * being sent by at least one side; apparently
6933 * I was wrong and it's perfectly OK to
6934 * unceremoniously slam the connection shut
6935 * when you're done, and indeed OpenSSH feels
6936 * this is more polite than sending a
6937 * DISCONNECT. So now we don't.
6938 */
6939 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6940 }
6941}
6942
6943static void ssh2_channel_check_close(struct ssh_channel *c)
6944{
6945 Ssh ssh = c->ssh;
6946 struct Packet *pktout;
6947
6948 if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
997097db 6949 == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.winadj_head) {
bc06669b 6950 /*
997097db 6951 * We have both sent and received EOF, and we have no
6952 * outstanding winadj channel requests, which means the
6953 * channel is in final wind-up. But we haven't sent CLOSE, so
6954 * let's do so now.
bc06669b 6955 */
6956 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6957 ssh2_pkt_adduint32(pktout, c->remoteid);
6958 ssh2_pkt_send(ssh, pktout);
6959 c->closes |= CLOSES_SENT_CLOSE;
6960 }
6961
6962 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
6963 /*
6964 * We have both sent and received CLOSE, which means we're
6965 * completely done with the channel.
6966 */
6967 ssh_channel_destroy(c);
6968 }
6969}
6970
6971static void ssh2_channel_got_eof(struct ssh_channel *c)
6972{
6973 if (c->closes & CLOSES_RCVD_EOF)
6974 return; /* already seen EOF */
6975 c->closes |= CLOSES_RCVD_EOF;
51df0ab5 6976
6977 if (c->type == CHAN_X11) {
bc06669b 6978 x11_send_eof(c->u.x11.s);
51df0ab5 6979 } else if (c->type == CHAN_AGENT) {
bc06669b 6980 /* Manufacture an outgoing EOF in response to the incoming one. */
6981 sshfwd_write_eof(c);
51df0ab5 6982 } else if (c->type == CHAN_SOCKDATA) {
bc06669b 6983 pfd_send_eof(c->u.pfd.s);
6984 } else if (c->type == CHAN_MAINSESSION) {
6985 Ssh ssh = c->ssh;
6986
4a202fc6 6987 if (!ssh->sent_console_eof &&
6988 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
bc06669b 6989 /*
4a202fc6 6990 * Either from_backend_eof told us that the front end
6991 * wants us to close the outgoing side of the connection
6992 * as soon as we see EOF from the far end, or else we've
6993 * unilaterally decided to do that because we've allocated
6994 * a remote pty and hence EOF isn't a particularly
6995 * meaningful concept.
bc06669b 6996 */
6997 sshfwd_write_eof(c);
6998 }
6999 ssh->sent_console_eof = TRUE;
51df0ab5 7000 }
bc06669b 7001
7002 ssh2_channel_check_close(c);
7003}
7004
7005static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7006{
7007 struct ssh_channel *c;
7008
7009 c = ssh2_channel_msg(ssh, pktin);
7010 if (!c)
7011 return;
7012 ssh2_channel_got_eof(c);
51df0ab5 7013}
7014
7015static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7016{
51df0ab5 7017 struct ssh_channel *c;
51df0ab5 7018
e223b7c7 7019 c = ssh2_channel_msg(ssh, pktin);
7020 if (!c)
51df0ab5 7021 return;
51df0ab5 7022
7023 /*
bc06669b 7024 * When we receive CLOSE on a channel, we assume it comes with an
7025 * implied EOF if we haven't seen EOF yet.
51df0ab5 7026 */
bc06669b 7027 ssh2_channel_got_eof(c);
7028
7029 /*
3effbcf2 7030 * And we also send an outgoing EOF, if we haven't already, on the
7031 * assumption that CLOSE is a pretty forceful announcement that
7032 * the remote side is doing away with the entire channel. (If it
7033 * had wanted to send us EOF and continue receiving data from us,
7034 * it would have just sent CHANNEL_EOF.)
3effbcf2 7035 */
a699eb41 7036 if (!(c->closes & CLOSES_SENT_EOF)) {
7037 /*
7038 * Make sure we don't read any more from whatever our local
7039 * data source is for this channel.
7040 */
7041 switch (c->type) {
7042 case CHAN_MAINSESSION:
7043 ssh->send_ok = 0; /* stop trying to read from stdin */
7044 break;
7045 case CHAN_X11:
7046 x11_override_throttle(c->u.x11.s, 1);
7047 break;
7048 case CHAN_SOCKDATA:
7049 pfd_override_throttle(c->u.pfd.s, 1);
7050 break;
7051 }
7052
7053 /*
7054 * Send outgoing EOF.
7055 */
7539afa2 7056 sshfwd_write_eof(c);
3effbcf2 7057 }
7058
7059 /*
bc06669b 7060 * Now process the actual close.
7061 */
7062 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7063 c->closes |= CLOSES_RCVD_CLOSE;
7064 ssh2_channel_check_close(c);
51df0ab5 7065 }
7066}
7067
7068static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7069{
51df0ab5 7070 struct ssh_channel *c;
51df0ab5 7071
e223b7c7 7072 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7073 if (!c)
e223b7c7 7074 return;
51df0ab5 7075 if (c->type != CHAN_SOCKDATA_DORMANT)
7076 return; /* dunno why they're confirming this */
7077 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7078 c->halfopen = FALSE;
51df0ab5 7079 c->type = CHAN_SOCKDATA;
7080 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7081 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7082 if (c->u.pfd.s)
7083 pfd_confirm(c->u.pfd.s);
bc06669b 7084 if (c->pending_eof)
7085 ssh_channel_try_eof(c);
51df0ab5 7086}
7087
7088static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7089{
7090 static const char *const reasons[] = {
7091 "<unknown reason code>",
7092 "Administratively prohibited",
7093 "Connect failed",
7094 "Unknown channel type",
7095 "Resource shortage",
7096 };
51df0ab5 7097 unsigned reason_code;
7098 char *reason_string;
7099 int reason_length;
51df0ab5 7100 struct ssh_channel *c;
e223b7c7 7101 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7102 if (!c)
e223b7c7 7103 return;
51df0ab5 7104 if (c->type != CHAN_SOCKDATA_DORMANT)
7105 return; /* dunno why they're failing this */
7106
7107 reason_code = ssh_pkt_getuint32(pktin);
7108 if (reason_code >= lenof(reasons))
7109 reason_code = 0; /* ensure reasons[reason_code] in range */
7110 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 7111 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7112 reasons[reason_code], reason_length, reason_string);
51df0ab5 7113
7114 pfd_close(c->u.pfd.s);
7115
7116 del234(ssh->channels, c);
7117 sfree(c);
7118}
7119
7120static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7121{
51df0ab5 7122 char *type;
7123 int typelen, want_reply;
7124 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7125 struct ssh_channel *c;
7126 struct Packet *pktout;
7127
e223b7c7 7128 c = ssh2_channel_msg(ssh, pktin);
7129 if (!c)
7130 return;
51df0ab5 7131 ssh_pkt_getstring(pktin, &type, &typelen);
7132 want_reply = ssh2_pkt_getbool(pktin);
7133
7134 /*
51df0ab5 7135 * Having got the channel number, we now look at
7136 * the request type string to see if it's something
7137 * we recognise.
7138 */
7139 if (c == ssh->mainchan) {
7140 /*
7141 * We recognise "exit-status" and "exit-signal" on
7142 * the primary channel.
7143 */
7144 if (typelen == 11 &&
7145 !memcmp(type, "exit-status", 11)) {
7146
7147 ssh->exitcode = ssh_pkt_getuint32(pktin);
7148 logeventf(ssh, "Server sent command exit status %d",
7149 ssh->exitcode);
7150 reply = SSH2_MSG_CHANNEL_SUCCESS;
7151
7152 } else if (typelen == 11 &&
7153 !memcmp(type, "exit-signal", 11)) {
7154
7155 int is_plausible = TRUE, is_int = FALSE;
7156 char *fmt_sig = "", *fmt_msg = "";
7157 char *msg;
7158 int msglen = 0, core = FALSE;
7159 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7160 * provide an `int' for the signal, despite its
bccbeb71 7161 * having been a `string' in the drafts of RFC 4254 since at
51df0ab5 7162 * least 2001. (Fixed in session.c 1.147.) Try to
7163 * infer which we can safely parse it as. */
7164 {
7165 unsigned char *p = pktin->body +
7166 pktin->savedpos;
7167 long len = pktin->length - pktin->savedpos;
7168 unsigned long num = GET_32BIT(p); /* what is it? */
7169 /* If it's 0, it hardly matters; assume string */
7170 if (num == 0) {
7171 is_int = FALSE;
7172 } else {
7173 int maybe_int = FALSE, maybe_str = FALSE;
7174#define CHECK_HYPOTHESIS(offset, result) \
7175 do { \
7176 long q = offset; \
7177 if (q >= 0 && q+4 <= len) { \
7178 q = q + 4 + GET_32BIT(p+q); \
7179 if (q >= 0 && q+4 <= len && \
c849ff23 7180 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 7181 result = TRUE; \
7182 } \
7183 } while(0)
7184 CHECK_HYPOTHESIS(4+1, maybe_int);
7185 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7186#undef CHECK_HYPOTHESIS
7187 if (maybe_int && !maybe_str)
7188 is_int = TRUE;
7189 else if (!maybe_int && maybe_str)
7190 is_int = FALSE;
7191 else
7192 /* Crikey. Either or neither. Panic. */
7193 is_plausible = FALSE;
7194 }
7195 }
d051d1b4 7196 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 7197 if (is_plausible) {
7198 if (is_int) {
7199 /* Old non-standard OpenSSH. */
7200 int signum = ssh_pkt_getuint32(pktin);
7201 fmt_sig = dupprintf(" %d", signum);
d051d1b4 7202 ssh->exitcode = 128 + signum;
51df0ab5 7203 } else {
bccbeb71 7204 /* As per RFC 4254. */
51df0ab5 7205 char *sig;
7206 int siglen;
7207 ssh_pkt_getstring(pktin, &sig, &siglen);
7208 /* Signal name isn't supposed to be blank, but
7209 * let's cope gracefully if it is. */
7210 if (siglen) {
7211 fmt_sig = dupprintf(" \"%.*s\"",
7212 siglen, sig);
7213 }
d051d1b4 7214
7215 /*
7216 * Really hideous method of translating the
7217 * signal description back into a locally
7218 * meaningful number.
7219 */
7220
7221 if (0)
7222 ;
b707973a 7223#define TRANSLATE_SIGNAL(s) \
7224 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7225 ssh->exitcode = 128 + SIG ## s
d051d1b4 7226#ifdef SIGABRT
b707973a 7227 TRANSLATE_SIGNAL(ABRT);
d051d1b4 7228#endif
7229#ifdef SIGALRM
b707973a 7230 TRANSLATE_SIGNAL(ALRM);
d051d1b4 7231#endif
7232#ifdef SIGFPE
b707973a 7233 TRANSLATE_SIGNAL(FPE);
d051d1b4 7234#endif
7235#ifdef SIGHUP
b707973a 7236 TRANSLATE_SIGNAL(HUP);
d051d1b4 7237#endif
7238#ifdef SIGILL
b707973a 7239 TRANSLATE_SIGNAL(ILL);
d051d1b4 7240#endif
7241#ifdef SIGINT
b707973a 7242 TRANSLATE_SIGNAL(INT);
d051d1b4 7243#endif
7244#ifdef SIGKILL
b707973a 7245 TRANSLATE_SIGNAL(KILL);
d051d1b4 7246#endif
7247#ifdef SIGPIPE
b707973a 7248 TRANSLATE_SIGNAL(PIPE);
d051d1b4 7249#endif
7250#ifdef SIGQUIT
b707973a 7251 TRANSLATE_SIGNAL(QUIT);
d051d1b4 7252#endif
7253#ifdef SIGSEGV
b707973a 7254 TRANSLATE_SIGNAL(SEGV);
d051d1b4 7255#endif
7256#ifdef SIGTERM
b707973a 7257 TRANSLATE_SIGNAL(TERM);
d051d1b4 7258#endif
7259#ifdef SIGUSR1
b707973a 7260 TRANSLATE_SIGNAL(USR1);
d051d1b4 7261#endif
7262#ifdef SIGUSR2
b707973a 7263 TRANSLATE_SIGNAL(USR2);
d051d1b4 7264#endif
b707973a 7265#undef TRANSLATE_SIGNAL
d051d1b4 7266 else
7267 ssh->exitcode = 128;
51df0ab5 7268 }
7269 core = ssh2_pkt_getbool(pktin);
7270 ssh_pkt_getstring(pktin, &msg, &msglen);
7271 if (msglen) {
7272 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7273 }
7274 /* ignore lang tag */
7275 } /* else don't attempt to parse */
7276 logeventf(ssh, "Server exited on signal%s%s%s",
7277 fmt_sig, core ? " (core dumped)" : "",
7278 fmt_msg);
7279 if (*fmt_sig) sfree(fmt_sig);
7280 if (*fmt_msg) sfree(fmt_msg);
7281 reply = SSH2_MSG_CHANNEL_SUCCESS;
7282
7283 }
7284 } else {
7285 /*
7286 * This is a channel request we don't know
7287 * about, so we now either ignore the request
7288 * or respond with CHANNEL_FAILURE, depending
7289 * on want_reply.
7290 */
7291 reply = SSH2_MSG_CHANNEL_FAILURE;
7292 }
7293 if (want_reply) {
7294 pktout = ssh2_pkt_init(reply);
7295 ssh2_pkt_adduint32(pktout, c->remoteid);
7296 ssh2_pkt_send(ssh, pktout);
7297 }
7298}
7299
7300static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7301{
7302 char *type;
7303 int typelen, want_reply;
7304 struct Packet *pktout;
7305
7306 ssh_pkt_getstring(pktin, &type, &typelen);
7307 want_reply = ssh2_pkt_getbool(pktin);
7308
7309 /*
7310 * We currently don't support any global requests
7311 * at all, so we either ignore the request or
7312 * respond with REQUEST_FAILURE, depending on
7313 * want_reply.
7314 */
7315 if (want_reply) {
7316 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7317 ssh2_pkt_send(ssh, pktout);
7318 }
7319}
7320
7321static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7322{
7323 char *type;
7324 int typelen;
7325 char *peeraddr;
7326 int peeraddrlen;
7327 int peerport;
7328 char *error = NULL;
7329 struct ssh_channel *c;
7330 unsigned remid, winsize, pktsize;
7331 struct Packet *pktout;
7332
7333 ssh_pkt_getstring(pktin, &type, &typelen);
7334 c = snew(struct ssh_channel);
7335 c->ssh = ssh;
7336
7337 remid = ssh_pkt_getuint32(pktin);
7338 winsize = ssh_pkt_getuint32(pktin);
7339 pktsize = ssh_pkt_getuint32(pktin);
7340
7341 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7342 char *addrstr;
5907ebda 7343 const char *x11err;
51df0ab5 7344
7345 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7346 addrstr = snewn(peeraddrlen+1, char);
7347 memcpy(addrstr, peeraddr, peeraddrlen);
7348 addrstr[peeraddrlen] = '\0';
7349 peerport = ssh_pkt_getuint32(pktin);
7350
7351 logeventf(ssh, "Received X11 connect request from %s:%d",
7352 addrstr, peerport);
7353
7354 if (!ssh->X11_fwd_enabled)
7355 error = "X11 forwarding is not enabled";
5907ebda 7356 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 7357 addrstr, peerport, ssh->conf)) != NULL) {
5907ebda 7358 logeventf(ssh, "Local X11 connection failed: %s", x11err);
51df0ab5 7359 error = "Unable to open an X11 connection";
7360 } else {
7361 logevent("Opening X11 forward connection succeeded");
7362 c->type = CHAN_X11;
7363 }
7364
7365 sfree(addrstr);
7366 } else if (typelen == 15 &&
7367 !memcmp(type, "forwarded-tcpip", 15)) {
7368 struct ssh_rportfwd pf, *realpf;
7369 char *dummy;
7370 int dummylen;
7371 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7372 pf.sport = ssh_pkt_getuint32(pktin);
7373 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7374 peerport = ssh_pkt_getuint32(pktin);
7375 realpf = find234(ssh->rportfwds, &pf, NULL);
7376 logeventf(ssh, "Received remote port %d open request "
7377 "from %s:%d", pf.sport, peeraddr, peerport);
7378 if (realpf == NULL) {
7379 error = "Remote port is not recognised";
7380 } else {
7381 const char *e = pfd_newconnect(&c->u.pfd.s,
7382 realpf->dhost,
7383 realpf->dport, c,
4a693cfc 7384 ssh->conf,
05581745 7385 realpf->pfrec->addressfamily);
51df0ab5 7386 logeventf(ssh, "Attempting to forward remote port to "
7387 "%s:%d", realpf->dhost, realpf->dport);
7388 if (e != NULL) {
7389 logeventf(ssh, "Port open failed: %s", e);
7390 error = "Port open failed";
7391 } else {
7392 logevent("Forwarded port opened successfully");
7393 c->type = CHAN_SOCKDATA;
7394 }
7395 }
7396 } else if (typelen == 22 &&
c49cf994 7397 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 7398 if (!ssh->agentfwd_enabled)
7399 error = "Agent forwarding is not enabled";
7400 else {
7401 c->type = CHAN_AGENT; /* identify channel type */
7402 c->u.a.lensofar = 0;
7403 }
7404 } else {
7405 error = "Unsupported channel type requested";
7406 }
7407
7408 c->remoteid = remid;
64d6ff88 7409 c->halfopen = FALSE;
51df0ab5 7410 if (error) {
7411 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7412 ssh2_pkt_adduint32(pktout, c->remoteid);
7413 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7414 ssh2_pkt_addstring(pktout, error);
7415 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7416 ssh2_pkt_send(ssh, pktout);
7417 logeventf(ssh, "Rejected channel open: %s", error);
7418 sfree(c);
7419 } else {
94bdfe40 7420 ssh2_channel_init(c);
51df0ab5 7421 c->v.v2.remwindow = winsize;
7422 c->v.v2.remmaxpkt = pktsize;
51df0ab5 7423 add234(ssh->channels, c);
7424 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7425 ssh2_pkt_adduint32(pktout, c->remoteid);
7426 ssh2_pkt_adduint32(pktout, c->localid);
7427 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 7428 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 7429 ssh2_pkt_send(ssh, pktout);
7430 }
7431}
7432
6bbce591 7433/*
adb6167a 7434 * Buffer banner messages for later display at some convenient point,
7435 * if we're going to display them.
6bbce591 7436 */
7437static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7438{
7439 /* Arbitrary limit to prevent unbounded inflation of buffer */
4a693cfc 7440 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
adb6167a 7441 bufchain_size(&ssh->banner) <= 131072) {
6bbce591 7442 char *banner = NULL;
7443 int size = 0;
7444 ssh_pkt_getstring(pktin, &banner, &size);
7445 if (banner)
7446 bufchain_add(&ssh->banner, banner, size);
7447 }
7448}
7449
c6ccd5c2 7450/* Helper function to deal with sending tty modes for "pty-req" */
7451static void ssh2_send_ttymode(void *data, char *mode, char *val)
7452{
7453 struct Packet *pktout = (struct Packet *)data;
7454 int i = 0;
7455 unsigned int arg = 0;
7456 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7457 if (i == lenof(ssh_ttymodes)) return;
7458 switch (ssh_ttymodes[i].type) {
7459 case TTY_OP_CHAR:
7460 arg = ssh_tty_parse_specchar(val);
7461 break;
7462 case TTY_OP_BOOL:
7463 arg = ssh_tty_parse_boolean(val);
7464 break;
7465 }
7466 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7467 ssh2_pkt_adduint32(pktout, arg);
7468}
7469
783415f8 7470/*
2e85c969 7471 * Handle the SSH-2 userauth and connection layers.
7cca0d81 7472 */
ff3187f6 7473static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7474 struct Packet *pktin)
7cca0d81 7475{
51470298 7476 struct do_ssh2_authconn_state {
7477 enum {
51470298 7478 AUTH_TYPE_NONE,
7479 AUTH_TYPE_PUBLICKEY,
7480 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7481 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7482 AUTH_TYPE_PASSWORD,
8221906d 7483 AUTH_TYPE_GSSAPI, /* always QUIET */
51470298 7484 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7485 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7486 } type;
a1a1fae4 7487 int done_service_req;
51470298 7488 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 7489 int tried_pubkey_config, done_agent;
bf84a03a 7490#ifndef NO_GSSAPI
42af6a67 7491 int can_gssapi;
7492 int tried_gssapi;
bf84a03a 7493#endif
edd0cb8a 7494 int kbd_inter_refused;
ab18ccff 7495 int we_are_in, userauth_success;
edd0cb8a 7496 prompts_t *cur_prompt;
7497 int num_prompts;
4a693cfc 7498 char *username;
e955d348 7499 char *password;
51470298 7500 int got_username;
51470298 7501 void *publickey_blob;
7502 int publickey_bloblen;
edd0cb8a 7503 int publickey_encrypted;
7504 char *publickey_algorithm;
7505 char *publickey_comment;
94cd7c3a 7506 unsigned char agent_request[5], *agent_response, *agentp;
7507 int agent_responselen;
7508 unsigned char *pkblob_in_agent;
51470298 7509 int keyi, nkeys;
51470298 7510 char *pkblob, *alg, *commentp;
7511 int pklen, alglen, commentlen;
7512 int siglen, retlen, len;
7513 char *q, *agentreq, *ret;
7514 int try_send;
c99deca4 7515 int requested_x11;
7516 int requested_agent;
7517 int requested_tty;
73feed4f 7518 int num_env, env_left, env_ok;
ff3187f6 7519 struct Packet *pktout;
4a693cfc 7520 Filename *keyfile;
bf84a03a 7521#ifndef NO_GSSAPI
b3d375b2 7522 struct ssh_gss_library *gsslib;
42af6a67 7523 Ssh_gss_ctx gss_ctx;
7524 Ssh_gss_buf gss_buf;
7525 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7526 Ssh_gss_name gss_srv_name;
7527 Ssh_gss_stat gss_stat;
bf84a03a 7528#endif
51470298 7529 };
7530 crState(do_ssh2_authconn_state);
7531
7532 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 7533
a1a1fae4 7534 s->done_service_req = FALSE;
ab18ccff 7535 s->we_are_in = s->userauth_success = FALSE;
bf84a03a 7536#ifndef NO_GSSAPI
42af6a67 7537 s->tried_gssapi = FALSE;
bf84a03a 7538#endif
42af6a67 7539
4a693cfc 7540 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
a1a1fae4 7541 /*
7542 * Request userauth protocol, and await a response to it.
7543 */
7544 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7545 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7546 ssh2_pkt_send(ssh, s->pktout);
7547 crWaitUntilV(pktin);
7548 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7549 s->done_service_req = TRUE;
7550 }
7551 if (!s->done_service_req) {
7552 /*
7553 * Request connection protocol directly, without authentication.
7554 */
7555 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7556 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7557 ssh2_pkt_send(ssh, s->pktout);
7558 crWaitUntilV(pktin);
7559 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7560 s->we_are_in = TRUE; /* no auth required */
7561 } else {
7562 bombout(("Server refused service request"));
7563 crStopV;
7564 }
8d5de777 7565 }
7cca0d81 7566
94cd7c3a 7567 /* Arrange to be able to deal with any BANNERs that come in.
7568 * (We do this now as packets may come in during the next bit.) */
7569 bufchain_init(&ssh->banner);
7570 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7571 ssh2_msg_userauth_banner;
7572
7cca0d81 7573 /*
edd0cb8a 7574 * Misc one-time setup for authentication.
7575 */
7576 s->publickey_blob = NULL;
7577 if (!s->we_are_in) {
7578
7579 /*
7580 * Load the public half of any configured public key file
7581 * for later use.
7582 */
4a693cfc 7583 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 7584 if (!filename_is_null(s->keyfile)) {
edd0cb8a 7585 int keytype;
7586 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 7587 filename_to_str(s->keyfile));
7588 keytype = key_type(s->keyfile);
edd0cb8a 7589 if (keytype == SSH_KEYTYPE_SSH2) {
7590 const char *error;
7591 s->publickey_blob =
4a693cfc 7592 ssh2_userkey_loadpub(s->keyfile,
edd0cb8a 7593 &s->publickey_algorithm,
7594 &s->publickey_bloblen,
7595 &s->publickey_comment, &error);
7596 if (s->publickey_blob) {
7597 s->publickey_encrypted =
4a693cfc 7598 ssh2_userkey_encrypted(s->keyfile, NULL);
edd0cb8a 7599 } else {
7600 char *msgbuf;
7601 logeventf(ssh, "Unable to load private key (%s)",
7602 error);
7603 msgbuf = dupprintf("Unable to load private key file "
7604 "\"%.150s\" (%s)\r\n",
4a693cfc 7605 filename_to_str(s->keyfile),
edd0cb8a 7606 error);
7607 c_write_str(ssh, msgbuf);
7608 sfree(msgbuf);
7609 }
7610 } else {
7611 char *msgbuf;
7612 logeventf(ssh, "Unable to use this key file (%s)",
7613 key_type_to_str(keytype));
7614 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7615 " (%s)\r\n",
4a693cfc 7616 filename_to_str(s->keyfile),
edd0cb8a 7617 key_type_to_str(keytype));
7618 c_write_str(ssh, msgbuf);
7619 sfree(msgbuf);
7620 s->publickey_blob = NULL;
7621 }
7622 }
7623
94cd7c3a 7624 /*
7625 * Find out about any keys Pageant has (but if there's a
7626 * public key configured, filter out all others).
7627 */
7628 s->nkeys = 0;
7629 s->agent_response = NULL;
7630 s->pkblob_in_agent = NULL;
4a693cfc 7631 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
94cd7c3a 7632
7633 void *r;
7634
7635 logevent("Pageant is running. Requesting keys.");
7636
7637 /* Request the keys held by the agent. */
7638 PUT_32BIT(s->agent_request, 1);
7639 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7640 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7641 ssh_agent_callback, ssh)) {
7642 do {
7643 crReturnV;
7644 if (pktin) {
7645 bombout(("Unexpected data from server while"
7646 " waiting for agent response"));
7647 crStopV;
7648 }
7649 } while (pktin || inlen > 0);
7650 r = ssh->agent_response;
7651 s->agent_responselen = ssh->agent_response_len;
7652 }
7653 s->agent_response = (unsigned char *) r;
7654 if (s->agent_response && s->agent_responselen >= 5 &&
7655 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7656 int keyi;
7657 unsigned char *p;
7658 p = s->agent_response + 5;
7659 s->nkeys = GET_32BIT(p);
7660 p += 4;
7661 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7662 if (s->publickey_blob) {
7663 /* See if configured key is in agent. */
7664 for (keyi = 0; keyi < s->nkeys; keyi++) {
7665 s->pklen = GET_32BIT(p);
7666 if (s->pklen == s->publickey_bloblen &&
7667 !memcmp(p+4, s->publickey_blob,
7668 s->publickey_bloblen)) {
7669 logeventf(ssh, "Pageant key #%d matches "
7670 "configured key file", keyi);
7671 s->keyi = keyi;
7672 s->pkblob_in_agent = p;
7673 break;
7674 }
7675 p += 4 + s->pklen;
7676 p += GET_32BIT(p) + 4; /* comment */
7677 }
7678 if (!s->pkblob_in_agent) {
7679 logevent("Configured key file not in Pageant");
7680 s->nkeys = 0;
7681 }
7682 }
5ff99b8e 7683 } else {
7684 logevent("Failed to get reply from Pageant");
94cd7c3a 7685 }
7686 }
7687
edd0cb8a 7688 }
7689
7690 /*
1408a877 7691 * We repeat this whole loop, including the username prompt,
7692 * until we manage a successful authentication. If the user
51470298 7693 * types the wrong _password_, they can be sent back to the
7694 * beginning to try another username, if this is configured on.
7695 * (If they specify a username in the config, they are never
7696 * asked, even if they do give a wrong password.)
1408a877 7697 *
7698 * I think this best serves the needs of
7699 *
7700 * - the people who have no configuration, no keys, and just
7701 * want to try repeated (username,password) pairs until they
7702 * type both correctly
7703 *
7704 * - people who have keys and configuration but occasionally
7705 * need to fall back to passwords
7706 *
7707 * - people with a key held in Pageant, who might not have
7708 * logged in to a particular machine before; so they want to
7709 * type a username, and then _either_ their key will be
7710 * accepted, _or_ they will type a password. If they mistype
7711 * the username they will want to be able to get back and
7712 * retype it!
7cca0d81 7713 */
51470298 7714 s->got_username = FALSE;
a1a1fae4 7715 while (!s->we_are_in) {
1408a877 7716 /*
7717 * Get a username.
7718 */
4a693cfc 7719 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
5bb641e1 7720 /*
7721 * We got a username last time round this loop, and
7722 * with change_username turned off we don't try to get
7723 * it again.
7724 */
4a693cfc 7725 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 7726 int ret; /* need not be kept over crReturn */
7727 s->cur_prompt = new_prompts(ssh->frontend);
7728 s->cur_prompt->to_server = TRUE;
7729 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 7730 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 7731 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7732 while (ret < 0) {
51470298 7733 ssh->send_ok = 1;
edd0cb8a 7734 crWaitUntilV(!pktin);
7735 ret = get_userpass_input(s->cur_prompt, in, inlen);
7736 ssh->send_ok = 0;
32874aea 7737 }
edd0cb8a 7738 if (!ret) {
7739 /*
7740 * get_userpass_input() failed to get a username.
7741 * Terminate.
7742 */
7743 free_prompts(s->cur_prompt);
7744 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7745 crStopV;
7746 }
4a693cfc 7747 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 7748 free_prompts(s->cur_prompt);
7cca0d81 7749 } else {
57356d63 7750 char *stuff;
65a22376 7751 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4a693cfc 7752 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
51470298 7753 c_write_str(ssh, stuff);
57356d63 7754 sfree(stuff);
7cca0d81 7755 }
7756 }
51470298 7757 s->got_username = TRUE;
7cca0d81 7758
65a22376 7759 /*
1408a877 7760 * Send an authentication request using method "none": (a)
7761 * just in case it succeeds, and (b) so that we know what
7762 * authentication methods we can usefully try next.
65a22376 7763 */
acab36bc 7764 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 7765
ff3187f6 7766 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7767 ssh2_pkt_addstring(s->pktout, ssh->username);
ff3187f6 7768 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7769 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7770 ssh2_pkt_send(ssh, s->pktout);
51470298 7771 s->type = AUTH_TYPE_NONE;
7772 s->gotit = FALSE;
7773 s->we_are_in = FALSE;
7774
7775 s->tried_pubkey_config = FALSE;
6ac3a551 7776 s->kbd_inter_refused = FALSE;
65a22376 7777
94cd7c3a 7778 /* Reset agent request state. */
7779 s->done_agent = FALSE;
7780 if (s->agent_response) {
7781 if (s->pkblob_in_agent) {
7782 s->agentp = s->pkblob_in_agent;
7783 } else {
7784 s->agentp = s->agent_response + 5 + 4;
7785 s->keyi = 0;
7786 }
7787 }
7788
1408a877 7789 while (1) {
854caca5 7790 char *methods = NULL;
7791 int methlen = 0;
7792
1408a877 7793 /*
7794 * Wait for the result of the last authentication request.
7795 */
51470298 7796 if (!s->gotit)
ff3187f6 7797 crWaitUntilV(pktin);
6bbce591 7798 /*
7799 * Now is a convenient point to spew any banner material
7800 * that we've accumulated. (This should ensure that when
7801 * we exit the auth loop, we haven't any left to deal
7802 * with.)
7803 */
7804 {
7805 int size = bufchain_size(&ssh->banner);
32874aea 7806 /*
7807 * Don't show the banner if we're operating in
7808 * non-verbose non-interactive mode. (It's probably
7809 * a script, which means nobody will read the
7810 * banner _anyway_, and moreover the printing of
7811 * the banner will screw up processing on the
7812 * output of (say) plink.)
7813 */
6bbce591 7814 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7815 char *banner = snewn(size, char);
7816 bufchain_fetch(&ssh->banner, banner, size);
7817 c_write_untrusted(ssh, banner, size);
7818 sfree(banner);
32874aea 7819 }
6bbce591 7820 bufchain_clear(&ssh->banner);
1408a877 7821 }
ff3187f6 7822 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 7823 logevent("Access granted");
ab18ccff 7824 s->we_are_in = s->userauth_success = TRUE;
1408a877 7825 break;
7826 }
65a22376 7827
42af6a67 7828 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
e955d348 7829 bombout(("Strange packet received during authentication: "
7830 "type %d", pktin->type));
7ffdbc1a 7831 crStopV;
65a22376 7832 }
7833
51470298 7834 s->gotit = FALSE;
65a22376 7835
1408a877 7836 /*
7837 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7838 * we can look at the string in it and know what we can
7839 * helpfully try next.
7840 */
ff3187f6 7841 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
ff3187f6 7842 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 7843 if (!ssh2_pkt_getbool(pktin)) {
1408a877 7844 /*
7845 * We have received an unequivocal Access
7846 * Denied. This can translate to a variety of
8221906d 7847 * messages, or no message at all.
7848 *
7849 * For forms of authentication which are attempted
7850 * implicitly, by which I mean without printing
7851 * anything in the window indicating that we're
7852 * trying them, we should never print 'Access
7853 * denied'.
7854 *
7855 * If we do print a message saying that we're
7856 * attempting some kind of authentication, it's OK
7857 * to print a followup message saying it failed -
7858 * but the message may sometimes be more specific
7859 * than simply 'Access denied'.
7860 *
1408a877 7861 * Additionally, if we'd just tried password
7862 * authentication, we should break out of this
7863 * whole loop so as to go back to the username
91f57d1f 7864 * prompt (iff we're configured to allow
7865 * username change attempts).
1408a877 7866 */
51470298 7867 if (s->type == AUTH_TYPE_NONE) {
1408a877 7868 /* do nothing */
51470298 7869 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7870 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7871 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7872 c_write_str(ssh, "Server refused our key\r\n");
8221906d 7873 logevent("Server refused our key");
7874 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
7875 /* This _shouldn't_ happen except by a
7876 * protocol bug causing client and server to
7877 * disagree on what is a correct signature. */
7878 c_write_str(ssh, "Server refused public-key signature"
7879 " despite accepting key!\r\n");
7880 logevent("Server refused public-key signature"
7881 " despite accepting key!");
51470298 7882 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8221906d 7883 /* quiet, so no c_write */
7884 logevent("Server refused keyboard-interactive authentication");
7885 } else if (s->type==AUTH_TYPE_GSSAPI) {
7886 /* always quiet, so no c_write */
2af4fe8f 7887 /* also, the code down in the GSSAPI block has
7888 * already logged this in the Event Log */
8221906d 7889 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
7890 logevent("Keyboard-interactive authentication failed");
7891 c_write_str(ssh, "Access denied\r\n");
7892 } else {
7893 assert(s->type == AUTH_TYPE_PASSWORD);
7894 logevent("Password authentication failed");
51470298 7895 c_write_str(ssh, "Access denied\r\n");
8221906d 7896
7897 if (conf_get_int(ssh->conf, CONF_change_username)) {
6c9dce7c 7898 /* XXX perhaps we should allow
7899 * keyboard-interactive to do this too? */
51470298 7900 s->we_are_in = FALSE;
1408a877 7901 break;
7902 }
7903 }
7904 } else {
51470298 7905 c_write_str(ssh, "Further authentication required\r\n");
1408a877 7906 logevent("Further authentication required");
7907 }
65a22376 7908
51470298 7909 s->can_pubkey =
32874aea 7910 in_commasep_string("publickey", methods, methlen);
51470298 7911 s->can_passwd =
32874aea 7912 in_commasep_string("password", methods, methlen);
4a693cfc 7913 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
761187b6 7914 in_commasep_string("keyboard-interactive", methods, methlen);
1e00c92b 7915#ifndef NO_GSSAPI
7916 if (!ssh->gsslibs)
4a693cfc 7917 ssh->gsslibs = ssh_gss_setup(ssh->conf);
7918 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
b3d375b2 7919 in_commasep_string("gssapi-with-mic", methods, methlen) &&
1e00c92b 7920 ssh->gsslibs->nlibraries > 0;
42af6a67 7921#endif
1408a877 7922 }
65a22376 7923
acab36bc 7924 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 7925
94cd7c3a 7926 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 7927
1983e559 7928 /*
94cd7c3a 7929 * Attempt public-key authentication using a key from Pageant.
1983e559 7930 */
1983e559 7931
acab36bc 7932 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 7933
94cd7c3a 7934 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7935
7936 /* Unpack key from agent response */
7937 s->pklen = GET_32BIT(s->agentp);
7938 s->agentp += 4;
7939 s->pkblob = (char *)s->agentp;
7940 s->agentp += s->pklen;
7941 s->alglen = GET_32BIT(s->pkblob);
7942 s->alg = s->pkblob + 4;
7943 s->commentlen = GET_32BIT(s->agentp);
7944 s->agentp += 4;
7945 s->commentp = (char *)s->agentp;
7946 s->agentp += s->commentlen;
7947 /* s->agentp now points at next key, if any */
7948
7949 /* See if server will accept it */
7950 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7951 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7952 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7953 /* service requested */
7954 ssh2_pkt_addstring(s->pktout, "publickey");
7955 /* method */
7956 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7957 ssh2_pkt_addstring_start(s->pktout);
7958 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7959 ssh2_pkt_addstring_start(s->pktout);
7960 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7961 ssh2_pkt_send(ssh, s->pktout);
7962 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 7963
94cd7c3a 7964 crWaitUntilV(pktin);
7965 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 7966
94cd7c3a 7967 /* Offer of key refused. */
7968 s->gotit = TRUE;
1983e559 7969
94cd7c3a 7970 } else {
7971
7972 void *vret;
1983e559 7973
94cd7c3a 7974 if (flags & FLAG_VERBOSE) {
7975 c_write_str(ssh, "Authenticating with "
7976 "public key \"");
7977 c_write(ssh, s->commentp, s->commentlen);
7978 c_write_str(ssh, "\" from agent\r\n");
7979 }
1983e559 7980
94cd7c3a 7981 /*
7982 * Server is willing to accept the key.
7983 * Construct a SIGN_REQUEST.
7984 */
7985 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7986 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7987 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7988 /* service requested */
7989 ssh2_pkt_addstring(s->pktout, "publickey");
7990 /* method */
7991 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7992 ssh2_pkt_addstring_start(s->pktout);
7993 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7994 ssh2_pkt_addstring_start(s->pktout);
7995 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7996
7997 /* Ask agent for signature. */
7998 s->siglen = s->pktout->length - 5 + 4 +
7999 ssh->v2_session_id_len;
8000 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8001 s->siglen -= 4;
8002 s->len = 1; /* message type */
8003 s->len += 4 + s->pklen; /* key blob */
8004 s->len += 4 + s->siglen; /* data to sign */
8005 s->len += 4; /* flags */
8006 s->agentreq = snewn(4 + s->len, char);
8007 PUT_32BIT(s->agentreq, s->len);
8008 s->q = s->agentreq + 4;
8009 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8010 PUT_32BIT(s->q, s->pklen);
8011 s->q += 4;
8012 memcpy(s->q, s->pkblob, s->pklen);
8013 s->q += s->pklen;
8014 PUT_32BIT(s->q, s->siglen);
8015 s->q += 4;
8016 /* Now the data to be signed... */
8017 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8018 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 8019 s->q += 4;
94cd7c3a 8020 }
8021 memcpy(s->q, ssh->v2_session_id,
8022 ssh->v2_session_id_len);
8023 s->q += ssh->v2_session_id_len;
8024 memcpy(s->q, s->pktout->data + 5,
8025 s->pktout->length - 5);
8026 s->q += s->pktout->length - 5;
8027 /* And finally the (zero) flags word. */
8028 PUT_32BIT(s->q, 0);
8029 if (!agent_query(s->agentreq, s->len + 4,
8030 &vret, &s->retlen,
8031 ssh_agent_callback, ssh)) {
8032 do {
8033 crReturnV;
8034 if (pktin) {
8035 bombout(("Unexpected data from server"
8036 " while waiting for agent"
8037 " response"));
8038 crStopV;
1983e559 8039 }
94cd7c3a 8040 } while (pktin || inlen > 0);
8041 vret = ssh->agent_response;
8042 s->retlen = ssh->agent_response_len;
8043 }
8044 s->ret = vret;
8045 sfree(s->agentreq);
8046 if (s->ret) {
8047 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
8048 logevent("Sending Pageant's response");
8049 ssh2_add_sigblob(ssh, s->pktout,
8050 s->pkblob, s->pklen,
8051 s->ret + 9,
8052 GET_32BIT(s->ret + 5));
8053 ssh2_pkt_send(ssh, s->pktout);
8054 s->type = AUTH_TYPE_PUBLICKEY;
8055 } else {
8056 /* FIXME: less drastic response */
8057 bombout(("Pageant failed to answer challenge"));
8058 crStopV;
1983e559 8059 }
8060 }
1983e559 8061 }
94cd7c3a 8062
8063 /* Do we have any keys left to try? */
8064 if (s->pkblob_in_agent) {
8065 s->done_agent = TRUE;
8066 s->tried_pubkey_config = TRUE;
8067 } else {
8068 s->keyi++;
8069 if (s->keyi >= s->nkeys)
8070 s->done_agent = TRUE;
8071 }
1983e559 8072
edd0cb8a 8073 } else if (s->can_pubkey && s->publickey_blob &&
8074 !s->tried_pubkey_config) {
65a22376 8075
edd0cb8a 8076 struct ssh2_userkey *key; /* not live over crReturn */
8077 char *passphrase; /* not live over crReturn */
65a22376 8078
acab36bc 8079 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8080
edd0cb8a 8081 s->tried_pubkey_config = TRUE;
8082
65a22376 8083 /*
1408a877 8084 * Try the public key supplied in the configuration.
8085 *
8086 * First, offer the public blob to see if the server is
8087 * willing to accept it.
65a22376 8088 */
ff3187f6 8089 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8090 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8091 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8092 /* service requested */
8093 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8094 ssh2_pkt_addbool(s->pktout, FALSE);
8095 /* no signature included */
8096 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8097 ssh2_pkt_addstring_start(s->pktout);
8098 ssh2_pkt_addstring_data(s->pktout,
8099 (char *)s->publickey_blob,
8100 s->publickey_bloblen);
ff3187f6 8101 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 8102 logevent("Offered public key");
ff3187f6 8103
8104 crWaitUntilV(pktin);
edd0cb8a 8105 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8106 /* Key refused. Give up. */
8107 s->gotit = TRUE; /* reconsider message next loop */
8108 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8109 continue; /* process this new message */
45068b27 8110 }
edd0cb8a 8111 logevent("Offer of public key accepted");
af659722 8112
45068b27 8113 /*
edd0cb8a 8114 * Actually attempt a serious authentication using
8115 * the key.
45068b27 8116 */
edd0cb8a 8117 if (flags & FLAG_VERBOSE) {
8118 c_write_str(ssh, "Authenticating with public key \"");
8119 c_write_str(ssh, s->publickey_comment);
8120 c_write_str(ssh, "\"\r\n");
8121 }
8122 key = NULL;
8123 while (!key) {
8124 const char *error; /* not live over crReturn */
8125 if (s->publickey_encrypted) {
8126 /*
8127 * Get a passphrase from the user.
8128 */
8129 int ret; /* need not be kept over crReturn */
8130 s->cur_prompt = new_prompts(ssh->frontend);
8131 s->cur_prompt->to_server = FALSE;
8132 s->cur_prompt->name = dupstr("SSH key passphrase");
8133 add_prompt(s->cur_prompt,
8134 dupprintf("Passphrase for key \"%.100s\": ",
8135 s->publickey_comment),
b61f81bc 8136 FALSE);
edd0cb8a 8137 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8138 while (ret < 0) {
8139 ssh->send_ok = 1;
8140 crWaitUntilV(!pktin);
8141 ret = get_userpass_input(s->cur_prompt,
8142 in, inlen);
8143 ssh->send_ok = 0;
8144 }
8145 if (!ret) {
8146 /* Failed to get a passphrase. Terminate. */
8147 free_prompts(s->cur_prompt);
8148 ssh_disconnect(ssh, NULL,
8149 "Unable to authenticate",
8150 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8151 TRUE);
8152 crStopV;
85fdbe25 8153 }
edd0cb8a 8154 passphrase =
8155 dupstr(s->cur_prompt->prompts[0]->result);
8156 free_prompts(s->cur_prompt);
45068b27 8157 } else {
edd0cb8a 8158 passphrase = NULL; /* no passphrase needed */
45068b27 8159 }
1408a877 8160
edd0cb8a 8161 /*
8162 * Try decrypting the key.
8163 */
4a693cfc 8164 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8165 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
edd0cb8a 8166 if (passphrase) {
8167 /* burn the evidence */
dfb88efd 8168 smemclr(passphrase, strlen(passphrase));
edd0cb8a 8169 sfree(passphrase);
8170 }
8171 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8172 if (passphrase &&
8173 (key == SSH2_WRONG_PASSPHRASE)) {
8174 c_write_str(ssh, "Wrong passphrase\r\n");
8175 key = NULL;
8176 /* and loop again */
8177 } else {
8178 c_write_str(ssh, "Unable to load private key (");
8179 c_write_str(ssh, error);
8180 c_write_str(ssh, ")\r\n");
8181 key = NULL;
8182 break; /* try something else */
8183 }
1408a877 8184 }
65a22376 8185 }
65a22376 8186
edd0cb8a 8187 if (key) {
1dd353b5 8188 unsigned char *pkblob, *sigblob, *sigdata;
8189 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 8190 int p;
65a22376 8191
1408a877 8192 /*
8193 * We have loaded the private key and the server
8194 * has announced that it's willing to accept it.
8195 * Hallelujah. Generate a signature and send it.
8196 */
ff3187f6 8197 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8198 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8199 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8200 /* service requested */
8201 ssh2_pkt_addstring(s->pktout, "publickey");
8202 /* method */
ff3187f6 8203 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 8204 /* signature follows */
ff3187f6 8205 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 8206 pkblob = key->alg->public_blob(key->data,
8207 &pkblob_len);
ff3187f6 8208 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 8209 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8210 pkblob_len);
1408a877 8211
8212 /*
8213 * The data to be signed is:
8214 *
8215 * string session-id
8216 *
8217 * followed by everything so far placed in the
8218 * outgoing packet.
8219 */
b672f405 8220 sigdata_len = s->pktout->length - 5 + 4 +
8221 ssh->v2_session_id_len;
edd0cb8a 8222 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8223 sigdata_len -= 4;
92d60585 8224 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 8225 p = 0;
8226 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8227 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8228 p += 4;
8229 }
b672f405 8230 memcpy(sigdata+p, ssh->v2_session_id,
8231 ssh->v2_session_id_len);
8232 p += ssh->v2_session_id_len;
ff3187f6 8233 memcpy(sigdata+p, s->pktout->data + 5,
8234 s->pktout->length - 5);
edd0cb8a 8235 p += s->pktout->length - 5;
8236 assert(p == sigdata_len);
d8baa528 8237 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 8238 sigdata_len, &sigblob_len);
ff3187f6 8239 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 8240 sigblob, sigblob_len);
8241 sfree(pkblob);
8242 sfree(sigblob);
1408a877 8243 sfree(sigdata);
8244
ff3187f6 8245 ssh2_pkt_send(ssh, s->pktout);
8221906d 8246 logevent("Sent public key signature");
51470298 8247 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 8248 key->alg->freekey(key->data);
1408a877 8249 }
edd0cb8a 8250
42af6a67 8251#ifndef NO_GSSAPI
8252 } else if (s->can_gssapi && !s->tried_gssapi) {
8253
8254 /* GSSAPI Authentication */
8255
86557057 8256 int micoffset, len;
8257 char *data;
42af6a67 8258 Ssh_gss_buf mic;
8259 s->type = AUTH_TYPE_GSSAPI;
8260 s->tried_gssapi = TRUE;
8261 s->gotit = TRUE;
8262 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8263
b3d375b2 8264 /*
8265 * Pick the highest GSS library on the preference
8266 * list.
8267 */
8268 {
8269 int i, j;
8270 s->gsslib = NULL;
8271 for (i = 0; i < ngsslibs; i++) {
4a693cfc 8272 int want_id = conf_get_int_int(ssh->conf,
8273 CONF_ssh_gsslist, i);
1e00c92b 8274 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8275 if (ssh->gsslibs->libraries[j].id == want_id) {
8276 s->gsslib = &ssh->gsslibs->libraries[j];
b3d375b2 8277 goto got_gsslib; /* double break */
8278 }
8279 }
8280 got_gsslib:
8281 /*
8282 * We always expect to have found something in
8283 * the above loop: we only came here if there
8284 * was at least one viable GSS library, and the
8285 * preference list should always mention
8286 * everything and only change the order.
8287 */
8288 assert(s->gsslib);
8289 }
8290
8291 if (s->gsslib->gsslogmsg)
8292 logevent(s->gsslib->gsslogmsg);
8293
42af6a67 8294 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8295 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8296 ssh2_pkt_addstring(s->pktout, ssh->username);
42af6a67 8297 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8298 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8221906d 8299 logevent("Attempting GSSAPI authentication");
42af6a67 8300
8301 /* add mechanism info */
b3d375b2 8302 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
42af6a67 8303
8304 /* number of GSSAPI mechanisms */
8305 ssh2_pkt_adduint32(s->pktout,1);
8306
8307 /* length of OID + 2 */
86557057 8308 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
42af6a67 8309 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8310
8311 /* length of OID */
86557057 8312 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
42af6a67 8313
86557057 8314 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8315 s->gss_buf.length);
42af6a67 8316 ssh2_pkt_send(ssh, s->pktout);
8317 crWaitUntilV(pktin);
8318 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8319 logevent("GSSAPI authentication request refused");
8320 continue;
8321 }
8322
8323 /* check returned packet ... */
8324
86557057 8325 ssh_pkt_getstring(pktin, &data, &len);
8326 s->gss_rcvtok.value = data;
8327 s->gss_rcvtok.length = len;
8328 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8329 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8330 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8331 memcmp((char *)s->gss_rcvtok.value + 2,
8332 s->gss_buf.value,s->gss_buf.length) ) {
42af6a67 8333 logevent("GSSAPI authentication - wrong response from server");
8334 continue;
8335 }
8336
8337 /* now start running */
b3d375b2 8338 s->gss_stat = s->gsslib->import_name(s->gsslib,
8339 ssh->fullhostname,
8340 &s->gss_srv_name);
42af6a67 8341 if (s->gss_stat != SSH_GSS_OK) {
8342 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8343 logevent("GSSAPI import name failed - Bad service name");
8344 else
8345 logevent("GSSAPI import name failed");
8346 continue;
8347 }
8348
8349 /* fetch TGT into GSS engine */
b3d375b2 8350 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
42af6a67 8351
8352 if (s->gss_stat != SSH_GSS_OK) {
8353 logevent("GSSAPI authentication failed to get credentials");
b3d375b2 8354 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
42af6a67 8355 continue;
8356 }
8357
8358 /* initial tokens are empty */
86557057 8359 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
99a3b3c9 8360 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
42af6a67 8361
8362 /* now enter the loop */
8363 do {
b3d375b2 8364 s->gss_stat = s->gsslib->init_sec_context
8365 (s->gsslib,
8366 &s->gss_ctx,
8367 s->gss_srv_name,
4a693cfc 8368 conf_get_int(ssh->conf, CONF_gssapifwd),
b3d375b2 8369 &s->gss_rcvtok,
8370 &s->gss_sndtok);
42af6a67 8371
8372 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8373 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8374 logevent("GSSAPI authentication initialisation failed");
8375
b3d375b2 8376 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8377 &s->gss_buf) == SSH_GSS_OK) {
86557057 8378 logevent(s->gss_buf.value);
8379 sfree(s->gss_buf.value);
42af6a67 8380 }
8381
8382 break;
8383 }
8384 logevent("GSSAPI authentication initialised");
8385
8386 /* Client and server now exchange tokens until GSSAPI
8387 * no longer says CONTINUE_NEEDED */
8388
86557057 8389 if (s->gss_sndtok.length != 0) {
42af6a67 8390 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8391 ssh_pkt_addstring_start(s->pktout);
86557057 8392 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
42af6a67 8393 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8394 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
42af6a67 8395 }
8396
8397 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8398 crWaitUntilV(pktin);
8399 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8400 logevent("GSSAPI authentication - bad server response");
8401 s->gss_stat = SSH_GSS_FAILURE;
8402 break;
8403 }
86557057 8404 ssh_pkt_getstring(pktin, &data, &len);
8405 s->gss_rcvtok.value = data;
8406 s->gss_rcvtok.length = len;
42af6a67 8407 }
8408 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8409
8410 if (s->gss_stat != SSH_GSS_OK) {
b3d375b2 8411 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8412 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8413 continue;
8414 }
8415 logevent("GSSAPI authentication loop finished OK");
8416
8417 /* Now send the MIC */
8418
8419 s->pktout = ssh2_pkt_init(0);
8420 micoffset = s->pktout->length;
8421 ssh_pkt_addstring_start(s->pktout);
8422 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8423 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8424 ssh_pkt_addstring(s->pktout, ssh->username);
42af6a67 8425 ssh_pkt_addstring(s->pktout, "ssh-connection");
8426 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8427
86557057 8428 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8429 s->gss_buf.length = s->pktout->length - micoffset;
42af6a67 8430
b3d375b2 8431 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
42af6a67 8432 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8433 ssh_pkt_addstring_start(s->pktout);
86557057 8434 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
42af6a67 8435 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8436 s->gsslib->free_mic(s->gsslib, &mic);
42af6a67 8437
8438 s->gotit = FALSE;
8439
b3d375b2 8440 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8441 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8442 continue;
8443#endif
edd0cb8a 8444 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8445
8446 /*
8447 * Keyboard-interactive authentication.
8448 */
edd0cb8a 8449
edd0cb8a 8450 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8451
acab36bc 8452 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 8453
8454 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8455 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8456 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8457 /* service requested */
8458 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8459 /* method */
8460 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8461 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8462 ssh2_pkt_send(ssh, s->pktout);
8221906d 8463
8464 logevent("Attempting keyboard-interactive authentication");
edd0cb8a 8465
8466 crWaitUntilV(pktin);
8467 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8468 /* Server is not willing to do keyboard-interactive
b8e3173d 8469 * at all (or, bizarrely but legally, accepts the
8470 * user without actually issuing any prompts).
8471 * Give up on it entirely. */
edd0cb8a 8472 s->gotit = TRUE;
edd0cb8a 8473 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8474 s->kbd_inter_refused = TRUE; /* don't try it again */
8475 continue;
8476 }
8477
8478 /*
b8e3173d 8479 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 8480 */
b8e3173d 8481 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 8482
b8e3173d 8483 char *name, *inst, *lang;
8484 int name_len, inst_len, lang_len;
8485 int i;
8486
8487 /*
8488 * We've got a fresh USERAUTH_INFO_REQUEST.
8489 * Get the preamble and start building a prompt.
8490 */
8491 ssh_pkt_getstring(pktin, &name, &name_len);
8492 ssh_pkt_getstring(pktin, &inst, &inst_len);
8493 ssh_pkt_getstring(pktin, &lang, &lang_len);
8494 s->cur_prompt = new_prompts(ssh->frontend);
8495 s->cur_prompt->to_server = TRUE;
edd0cb8a 8496
b8e3173d 8497 /*
9ea10e78 8498 * Get any prompt(s) from the packet.
b8e3173d 8499 */
8500 s->num_prompts = ssh_pkt_getuint32(pktin);
8501 for (i = 0; i < s->num_prompts; i++) {
8502 char *prompt;
8503 int prompt_len;
8504 int echo;
8505 static char noprompt[] =
8506 "<server failed to send prompt>: ";
8507
8508 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8509 echo = ssh2_pkt_getbool(pktin);
8510 if (!prompt_len) {
8511 prompt = noprompt;
8512 prompt_len = lenof(noprompt)-1;
8513 }
8514 add_prompt(s->cur_prompt,
8515 dupprintf("%.*s", prompt_len, prompt),
b61f81bc 8516 echo);
edd0cb8a 8517 }
b8e3173d 8518
9874c9d7 8519 if (name_len) {
8520 /* FIXME: better prefix to distinguish from
8521 * local prompts? */
8522 s->cur_prompt->name =
8523 dupprintf("SSH server: %.*s", name_len, name);
8524 s->cur_prompt->name_reqd = TRUE;
8525 } else {
8526 s->cur_prompt->name =
8527 dupstr("SSH server authentication");
8528 s->cur_prompt->name_reqd = FALSE;
8529 }
8530 /* We add a prefix to try to make it clear that a prompt
8531 * has come from the server.
8532 * FIXME: ugly to print "Using..." in prompt _every_
8533 * time round. Can this be done more subtly? */
8534 /* Special case: for reasons best known to themselves,
8535 * some servers send k-i requests with no prompts and
8536 * nothing to display. Keep quiet in this case. */
8537 if (s->num_prompts || name_len || inst_len) {
8538 s->cur_prompt->instruction =
8539 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8540 inst_len ? "\n" : "", inst_len, inst);
8541 s->cur_prompt->instr_reqd = TRUE;
8542 } else {
8543 s->cur_prompt->instr_reqd = FALSE;
8544 }
8545
b8e3173d 8546 /*
9ea10e78 8547 * Display any instructions, and get the user's
8548 * response(s).
b8e3173d 8549 */
9ea10e78 8550 {
b8e3173d 8551 int ret; /* not live over crReturn */
8552 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8553 while (ret < 0) {
8554 ssh->send_ok = 1;
8555 crWaitUntilV(!pktin);
8556 ret = get_userpass_input(s->cur_prompt, in, inlen);
8557 ssh->send_ok = 0;
8558 }
8559 if (!ret) {
8560 /*
8561 * Failed to get responses. Terminate.
8562 */
8563 free_prompts(s->cur_prompt);
8564 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8565 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8566 TRUE);
8567 crStopV;
8568 }
edd0cb8a 8569 }
b8e3173d 8570
8571 /*
9ea10e78 8572 * Send the response(s) to the server.
b8e3173d 8573 */
8574 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 8575 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8576 for (i=0; i < s->num_prompts; i++) {
8577 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8578 ssh2_pkt_addstring(s->pktout,
8579 s->cur_prompt->prompts[i]->result);
8580 end_log_omission(ssh, s->pktout);
8581 }
18524056 8582 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 8583
c69784c0 8584 /*
8585 * Free the prompts structure from this iteration.
8586 * If there's another, a new one will be allocated
8587 * when we return to the top of this while loop.
8588 */
8589 free_prompts(s->cur_prompt);
8590
b8e3173d 8591 /*
8592 * Get the next packet in case it's another
8593 * INFO_REQUEST.
8594 */
8595 crWaitUntilV(pktin);
8596
edd0cb8a 8597 }
8598
8599 /*
b8e3173d 8600 * We should have SUCCESS or FAILURE now.
edd0cb8a 8601 */
b8e3173d 8602 s->gotit = TRUE;
edd0cb8a 8603
8604 } else if (s->can_passwd) {
8605
8606 /*
8607 * Plain old password authentication.
8608 */
8609 int ret; /* not live over crReturn */
e955d348 8610 int changereq_first_time; /* not live over crReturn */
edd0cb8a 8611
acab36bc 8612 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 8613
8614 s->cur_prompt = new_prompts(ssh->frontend);
8615 s->cur_prompt->to_server = TRUE;
8616 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 8617 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8618 ssh->username,
edd0cb8a 8619 ssh->savedhost),
b61f81bc 8620 FALSE);
edd0cb8a 8621
8622 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8623 while (ret < 0) {
8624 ssh->send_ok = 1;
8625 crWaitUntilV(!pktin);
8626 ret = get_userpass_input(s->cur_prompt, in, inlen);
8627 ssh->send_ok = 0;
8628 }
8629 if (!ret) {
8630 /*
8631 * Failed to get responses. Terminate.
8632 */
8633 free_prompts(s->cur_prompt);
8634 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8635 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8636 TRUE);
8637 crStopV;
8638 }
e955d348 8639 /*
8640 * Squirrel away the password. (We may need it later if
8641 * asked to change it.)
8642 */
8643 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8644 free_prompts(s->cur_prompt);
edd0cb8a 8645
8646 /*
8647 * Send the password packet.
8648 *
95d2d262 8649 * We pad out the password packet to 256 bytes to make
8650 * it harder for an attacker to find the length of the
8651 * user's password.
1408a877 8652 *
95d2d262 8653 * Anyone using a password longer than 256 bytes
8654 * probably doesn't have much to worry about from
1408a877 8655 * people who find out how long their password is!
65a22376 8656 */
ff3187f6 8657 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8658 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8659 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8660 /* service requested */
ff3187f6 8661 ssh2_pkt_addstring(s->pktout, "password");
8662 ssh2_pkt_addbool(s->pktout, FALSE);
8663 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 8664 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 8665 end_log_omission(ssh, s->pktout);
18524056 8666 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 8667 logevent("Sent password");
28f4d4f0 8668 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 8669
e955d348 8670 /*
8671 * Wait for next packet, in case it's a password change
8672 * request.
8673 */
8674 crWaitUntilV(pktin);
8675 changereq_first_time = TRUE;
8676
8677 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8678
8679 /*
8680 * We're being asked for a new password
8681 * (perhaps not for the first time).
8682 * Loop until the server accepts it.
8683 */
8684
8685 int got_new = FALSE; /* not live over crReturn */
8686 char *prompt; /* not live over crReturn */
8687 int prompt_len; /* not live over crReturn */
8688
8689 {
8690 char *msg;
8691 if (changereq_first_time)
8692 msg = "Server requested password change";
8693 else
8694 msg = "Server rejected new password";
8695 logevent(msg);
8696 c_write_str(ssh, msg);
8697 c_write_str(ssh, "\r\n");
8698 }
8699
8700 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8701
8702 s->cur_prompt = new_prompts(ssh->frontend);
8703 s->cur_prompt->to_server = TRUE;
8704 s->cur_prompt->name = dupstr("New SSH password");
8705 s->cur_prompt->instruction =
8706 dupprintf("%.*s", prompt_len, prompt);
8707 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 8708 /*
8709 * There's no explicit requirement in the protocol
8710 * for the "old" passwords in the original and
8711 * password-change messages to be the same, and
8712 * apparently some Cisco kit supports password change
8713 * by the user entering a blank password originally
8714 * and the real password subsequently, so,
8715 * reluctantly, we prompt for the old password again.
8716 *
8717 * (On the other hand, some servers don't even bother
8718 * to check this field.)
8719 */
8720 add_prompt(s->cur_prompt,
8721 dupstr("Current password (blank for previously entered password): "),
b61f81bc 8722 FALSE);
e955d348 8723 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
b61f81bc 8724 FALSE);
e955d348 8725 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
b61f81bc 8726 FALSE);
e955d348 8727
8728 /*
8729 * Loop until the user manages to enter the same
8730 * password twice.
8731 */
8732 while (!got_new) {
8733
8734 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8735 while (ret < 0) {
8736 ssh->send_ok = 1;
8737 crWaitUntilV(!pktin);
8738 ret = get_userpass_input(s->cur_prompt, in, inlen);
8739 ssh->send_ok = 0;
8740 }
8741 if (!ret) {
8742 /*
8743 * Failed to get responses. Terminate.
8744 */
8745 /* burn the evidence */
8746 free_prompts(s->cur_prompt);
dfb88efd 8747 smemclr(s->password, strlen(s->password));
e955d348 8748 sfree(s->password);
8749 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8750 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8751 TRUE);
8752 crStopV;
8753 }
8754
8755 /*
d9add7bc 8756 * If the user specified a new original password
8757 * (IYSWIM), overwrite any previously specified
8758 * one.
8759 * (A side effect is that the user doesn't have to
8760 * re-enter it if they louse up the new password.)
8761 */
8762 if (s->cur_prompt->prompts[0]->result[0]) {
dfb88efd 8763 smemclr(s->password, strlen(s->password));
d9add7bc 8764 /* burn the evidence */
8765 sfree(s->password);
8766 s->password =
8767 dupstr(s->cur_prompt->prompts[0]->result);
8768 }
8769
8770 /*
8771 * Check the two new passwords match.
e955d348 8772 */
d9add7bc 8773 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8774 s->cur_prompt->prompts[2]->result)
e955d348 8775 == 0);
8776 if (!got_new)
8777 /* They don't. Silly user. */
8778 c_write_str(ssh, "Passwords do not match\r\n");
8779
8780 }
8781
8782 /*
8783 * Send the new password (along with the old one).
8784 * (see above for padding rationale)
8785 */
8786 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8787 ssh2_pkt_addstring(s->pktout, ssh->username);
e955d348 8788 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8789 /* service requested */
8790 ssh2_pkt_addstring(s->pktout, "password");
8791 ssh2_pkt_addbool(s->pktout, TRUE);
8792 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8793 ssh2_pkt_addstring(s->pktout, s->password);
8794 ssh2_pkt_addstring(s->pktout,
d9add7bc 8795 s->cur_prompt->prompts[1]->result);
e955d348 8796 free_prompts(s->cur_prompt);
8797 end_log_omission(ssh, s->pktout);
18524056 8798 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 8799 logevent("Sent new password");
8800
8801 /*
8802 * Now see what the server has to say about it.
8803 * (If it's CHANGEREQ again, it's not happy with the
8804 * new password.)
8805 */
8806 crWaitUntilV(pktin);
8807 changereq_first_time = FALSE;
8808
8809 }
8810
8811 /*
8812 * We need to reexamine the current pktin at the top
8813 * of the loop. Either:
8814 * - we weren't asked to change password at all, in
8815 * which case it's a SUCCESS or FAILURE with the
8816 * usual meaning
8817 * - we sent a new password, and the server was
8818 * either OK with it (SUCCESS or FAILURE w/partial
8819 * success) or unhappy with the _old_ password
8820 * (FAILURE w/o partial success)
8821 * In any of these cases, we go back to the top of
8822 * the loop and start again.
8823 */
8824 s->gotit = TRUE;
8825
8826 /*
8827 * We don't need the old password any more, in any
8828 * case. Burn the evidence.
8829 */
dfb88efd 8830 smemclr(s->password, strlen(s->password));
e955d348 8831 sfree(s->password);
8832
1408a877 8833 } else {
854caca5 8834 char *str = dupprintf("No supported authentication methods available"
8835 " (server sent: %.*s)",
8836 methlen, methods);
edd0cb8a 8837
854caca5 8838 ssh_disconnect(ssh, str,
9e296bfa 8839 "No supported authentication methods available",
8840 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8841 FALSE);
854caca5 8842 sfree(str);
8843
7ffdbc1a 8844 crStopV;
edd0cb8a 8845
65a22376 8846 }
edd0cb8a 8847
65a22376 8848 }
a1a1fae4 8849 }
6bbce591 8850 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 8851
edd0cb8a 8852 /* Clear up various bits and pieces from authentication. */
8853 if (s->publickey_blob) {
8854 sfree(s->publickey_blob);
8855 sfree(s->publickey_comment);
8856 }
94cd7c3a 8857 if (s->agent_response)
8858 sfree(s->agent_response);
edd0cb8a 8859
ab18ccff 8860 if (s->userauth_success) {
8861 /*
8862 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8863 * packets since. Signal the transport layer to consider enacting
8864 * delayed compression.
8865 *
8866 * (Relying on we_are_in is not sufficient, as
8867 * draft-miller-secsh-compression-delayed is quite clear that it
8868 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8869 * become set for other reasons.)
8870 */
8871 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
8872 }
8873
7cca0d81 8874 /*
a1a1fae4 8875 * Now the connection protocol has started, one way or another.
7cca0d81 8876 */
8877
0ed48730 8878 ssh->channels = newtree234(ssh_channelcmp);
8879
7cca0d81 8880 /*
b09eaa88 8881 * Set up handlers for some connection protocol messages, so we
8882 * don't have to handle them repeatedly in this coroutine.
8883 */
8884 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8885 ssh2_msg_channel_window_adjust;
51df0ab5 8886 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8887 ssh2_msg_global_request;
b09eaa88 8888
8889 /*
0ed48730 8890 * Create the main session channel.
7cca0d81 8891 */
4a693cfc 8892 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
feb02b4e 8893 ssh->mainchan = NULL;
4a693cfc 8894 } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
feb02b4e 8895 /*
8896 * Just start a direct-tcpip channel and use it as the main
8897 * channel.
8898 */
8899 ssh->mainchan = snew(struct ssh_channel);
8900 ssh->mainchan->ssh = ssh;
94bdfe40 8901 ssh2_channel_init(ssh->mainchan);
23828b7e 8902 logeventf(ssh,
8903 "Opening direct-tcpip channel to %s:%d in place of session",
4a693cfc 8904 conf_get_str(ssh->conf, CONF_ssh_nc_host),
8905 conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8906 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8907 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8908 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
feb02b4e 8909 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8910 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
4a693cfc 8911 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host));
8912 ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8913 /*
23828b7e 8914 * There's nothing meaningful to put in the originator
8915 * fields, but some servers insist on syntactically correct
8916 * information.
feb02b4e 8917 */
8918 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8919 ssh2_pkt_adduint32(s->pktout, 0);
8920 ssh2_pkt_send(ssh, s->pktout);
8921
8922 crWaitUntilV(pktin);
8923 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8924 bombout(("Server refused to open a direct-tcpip channel"));
8925 crStopV;
8926 /* FIXME: error data comes back in FAILURE packet */
8927 }
8928 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8929 bombout(("Server's channel confirmation cited wrong channel"));
8930 crStopV;
8931 }
8932 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8933 ssh->mainchan->halfopen = FALSE;
8934 ssh->mainchan->type = CHAN_MAINSESSION;
feb02b4e 8935 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8936 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
feb02b4e 8937 add234(ssh->channels, ssh->mainchan);
8938 update_specials_menu(ssh->frontend);
23828b7e 8939 logevent("Opened direct-tcpip channel");
feb02b4e 8940 ssh->ncmode = TRUE;
8941 } else {
0ed48730 8942 ssh->mainchan = snew(struct ssh_channel);
8943 ssh->mainchan->ssh = ssh;
94bdfe40 8944 ssh2_channel_init(ssh->mainchan);
ff3187f6 8945 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8946 ssh2_pkt_addstring(s->pktout, "session");
8947 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
ff3187f6 8948 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 8949 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8950 ssh2_pkt_send(ssh, s->pktout);
8951 crWaitUntilV(pktin);
8952 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 8953 bombout(("Server refused to open a session"));
8954 crStopV;
8955 /* FIXME: error data comes back in FAILURE packet */
8956 }
ff3187f6 8957 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 8958 bombout(("Server's channel confirmation cited wrong channel"));
8959 crStopV;
8960 }
ff3187f6 8961 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 8962 ssh->mainchan->halfopen = FALSE;
0ed48730 8963 ssh->mainchan->type = CHAN_MAINSESSION;
ff3187f6 8964 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8965 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 8966 add234(ssh->channels, ssh->mainchan);
62638676 8967 update_specials_menu(ssh->frontend);
0ed48730 8968 logevent("Opened channel for session");
feb02b4e 8969 ssh->ncmode = FALSE;
8970 }
7cca0d81 8971
8972 /*
51df0ab5 8973 * Now we have a channel, make dispatch table entries for
8974 * general channel-based messages.
8975 */
8976 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8977 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8978 ssh2_msg_channel_data;
8979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8980 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8982 ssh2_msg_channel_open_confirmation;
8983 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8984 ssh2_msg_channel_open_failure;
8985 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8986 ssh2_msg_channel_request;
8987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8988 ssh2_msg_channel_open;
8989
4a693cfc 8990 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
3361b80a 8991 /*
8992 * This message indicates to the server that we promise
8993 * not to try to run any other channel in parallel with
8994 * this one, so it's safe for it to advertise a very large
8995 * window and leave the flow control to TCP.
8996 */
8997 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8998 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8999 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
9000 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
9001 ssh2_pkt_send(ssh, s->pktout);
9002 }
9003
51df0ab5 9004 /*
c99deca4 9005 * Enable port forwardings.
9006 */
9007 ssh_setup_portfwd(ssh, ssh->conf);
9008
9009 /*
9010 * Send the CHANNEL_REQUESTS for the main channel. We send them all
9011 * and then start looking for responses, so it's important that the
9012 * sending and receiving code below it is kept in sync.
9013 */
9014
9015 /*
783415f8 9016 * Potentially enable X11 forwarding.
9017 */
4a693cfc 9018 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) &&
9019 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9020 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 9021 logevent("Requesting X11 forwarding");
ff3187f6 9022 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9023 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9024 ssh2_pkt_addstring(s->pktout, "x11-req");
9025 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9026 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8def70c3 9027 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
f68353be 9028 /*
9029 * Note that while we blank the X authentication data here, we don't
9030 * take any special action to blank the start of an X11 channel,
9031 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
9032 * without having session blanking enabled is likely to leak your
9033 * cookie into the log.
9034 */
178c3872 9035 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8def70c3 9036 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
178c3872 9037 end_log_omission(ssh, s->pktout);
8def70c3 9038 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
ff3187f6 9039 ssh2_pkt_send(ssh, s->pktout);
c99deca4 9040 s->requested_x11 = TRUE;
9041 } else
9042 s->requested_x11 = FALSE;
bc240b21 9043
9044 /*
36c2a3e9 9045 * Potentially enable agent forwarding.
9046 */
4a693cfc 9047 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 9048 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 9049 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9050 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9051 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
9052 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9053 ssh2_pkt_send(ssh, s->pktout);
c99deca4 9054 s->requested_agent = TRUE;
9055 } else
9056 s->requested_agent = FALSE;
36c2a3e9 9057
9058 /*
7cca0d81 9059 * Now allocate a pty for the session.
9060 */
4a693cfc 9061 if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) {
a5dd8467 9062 /* Unpick the terminal-speed string. */
9063 /* XXX perhaps we should allow no speeds to be sent. */
db219738 9064 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 9065 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 9066 /* Build the pty request. */
ff3187f6 9067 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9068 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
9069 ssh2_pkt_addstring(s->pktout, "pty-req");
9070 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9071 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_termtype));
ff3187f6 9072 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
9073 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
9074 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
9075 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
9076 ssh2_pkt_addstring_start(s->pktout);
4a693cfc 9077 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)s->pktout);
c6ccd5c2 9078 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
ff3187f6 9079 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
c6ccd5c2 9080 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
ff3187f6 9081 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
9082 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
9083 ssh2_pkt_send(ssh, s->pktout);
51470298 9084 ssh->state = SSH_STATE_INTERMED;
c99deca4 9085 s->requested_tty = TRUE;
9086 } else
9087 s->requested_tty = FALSE;
7cca0d81 9088
9089 /*
73feed4f 9090 * Send environment variables.
9091 *
9092 * Simplest thing here is to send all the requests at once, and
9093 * then wait for a whole bunch of successes or failures.
9094 */
c99deca4 9095 s->num_env = 0;
4a693cfc 9096 if (ssh->mainchan && !ssh->ncmode) {
9097 char *key, *val;
73feed4f 9098
4a693cfc 9099 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9100 val != NULL;
9101 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
ff3187f6 9102 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9103 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9104 ssh2_pkt_addstring(s->pktout, "env");
9105 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9106 ssh2_pkt_addstring(s->pktout, key);
ff3187f6 9107 ssh2_pkt_addstring(s->pktout, val);
9108 ssh2_pkt_send(ssh, s->pktout);
73feed4f 9109
9110 s->num_env++;
9111 }
c99deca4 9112 if (s->num_env)
4a693cfc 9113 logeventf(ssh, "Sent %d environment variables", s->num_env);
c99deca4 9114 }
73feed4f 9115
c99deca4 9116 /*
9117 * All CHANNEL_REQUESTs sent. Now collect up the replies. These
9118 * must be in precisely the same order as the requests.
9119 */
73feed4f 9120
c99deca4 9121 if (s->requested_x11) {
9122 crWaitUntilV(pktin);
73feed4f 9123
c99deca4 9124 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9125 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9126 bombout(("Unexpected response to X11 forwarding request:"
9127 " packet type %d", pktin->type));
9128 crStopV;
9129 }
9130 logevent("X11 forwarding refused");
9131 } else {
9132 logevent("X11 forwarding enabled");
9133 ssh->X11_fwd_enabled = TRUE;
9134 }
9135 }
9136
9137 if (s->requested_agent) {
9138 crWaitUntilV(pktin);
9139
9140 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9141 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9142 bombout(("Unexpected response to agent forwarding request:"
9143 " packet type %d", pktin->type));
9144 crStopV;
9145 }
9146 logevent("Agent forwarding refused");
9147 } else {
9148 logevent("Agent forwarding enabled");
9149 ssh->agentfwd_enabled = TRUE;
9150 }
9151 }
9152
9153 if (s->requested_tty) {
9154 crWaitUntilV(pktin);
73feed4f 9155
c99deca4 9156 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9157 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9158 bombout(("Unexpected response to pty request:"
9159 " packet type %d", pktin->type));
9160 crStopV;
4a693cfc 9161 }
c99deca4 9162 c_write_str(ssh, "Server refused to allocate pty\r\n");
9163 ssh->editing = ssh->echoing = 1;
9164 } else {
9165 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9166 ssh->ospeed, ssh->ispeed);
9167 ssh->got_pty = TRUE;
9168 }
9169 } else {
9170 ssh->editing = ssh->echoing = 1;
9171 }
73feed4f 9172
c99deca4 9173 if (s->num_env) {
9174 s->env_ok = 0;
9175 s->env_left = s->num_env;
9176
9177 while (s->env_left > 0) {
9178 crWaitUntilV(pktin);
9179
9180 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9181 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9182 bombout(("Unexpected response to environment request:"
9183 " packet type %d", pktin->type));
9184 crStopV;
9185 }
4a693cfc 9186 } else {
c99deca4 9187 s->env_ok++;
4a693cfc 9188 }
c99deca4 9189
9190 s->env_left--;
9191 }
9192
9193 if (s->env_ok == s->num_env) {
9194 logevent("All environment variables successfully set");
9195 } else if (s->env_ok == 0) {
9196 logevent("All environment variables refused");
9197 c_write_str(ssh, "Server refused to set environment variables\r\n");
9198 } else {
9199 logeventf(ssh, "%d environment variables refused",
9200 s->num_env - s->env_ok);
9201 c_write_str(ssh, "Server refused to set all environment variables\r\n");
73feed4f 9202 }
9203 }
9204
9205 /*
fd5e5847 9206 * Start a shell or a remote command. We may have to attempt
9207 * this twice if the config data has provided a second choice
9208 * of command.
7cca0d81 9209 */
feb02b4e 9210 if (ssh->mainchan && !ssh->ncmode) while (1) {
fd5e5847 9211 int subsys;
9212 char *cmd;
9213
51470298 9214 if (ssh->fallback_cmd) {
4a693cfc 9215 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9216 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
fd5e5847 9217 } else {
4a693cfc 9218 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9219 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 9220 }
9221
ff3187f6 9222 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9223 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 9224 if (subsys) {
ff3187f6 9225 ssh2_pkt_addstring(s->pktout, "subsystem");
9226 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9227 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9228 } else if (*cmd) {
ff3187f6 9229 ssh2_pkt_addstring(s->pktout, "exec");
9230 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9231 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9232 } else {
ff3187f6 9233 ssh2_pkt_addstring(s->pktout, "shell");
9234 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 9235 }
ff3187f6 9236 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 9237
9238 crWaitUntilV(pktin);
9239
ff3187f6 9240 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9241 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9242 bombout(("Unexpected response to shell/command request:"
ff3187f6 9243 " packet type %d", pktin->type));
7ffdbc1a 9244 crStopV;
fd5e5847 9245 }
9246 /*
9247 * We failed to start the command. If this is the
9248 * fallback command, we really are finished; if it's
9249 * not, and if the fallback command exists, try falling
9250 * back to it before complaining.
9251 */
4a693cfc 9252 if (!ssh->fallback_cmd &&
9253 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
fd5e5847 9254 logevent("Primary command failed; attempting fallback");
51470298 9255 ssh->fallback_cmd = TRUE;
fd5e5847 9256 continue;
9257 }
6b5cf8b4 9258 bombout(("Server refused to start a shell/command"));
7ffdbc1a 9259 crStopV;
fd5e5847 9260 } else {
9261 logevent("Started a shell/command");
32874aea 9262 }
fd5e5847 9263 break;
7cca0d81 9264 }
9265
51470298 9266 ssh->state = SSH_STATE_SESSION;
9267 if (ssh->size_needed)
9268 ssh_size(ssh, ssh->term_width, ssh->term_height);
9269 if (ssh->eof_needed)
9270 ssh_special(ssh, TS_EOF);
6e48c3fe 9271
7cca0d81 9272 /*
0e443c99 9273 * All the initial channel requests are done, so install the default
9274 * failure handler.
9275 */
837d6ba6 9276 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
0e443c99 9277 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
9278
9279 /*
7cca0d81 9280 * Transfer data!
9281 */
b9d7bcad 9282 if (ssh->ldisc)
9283 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 9284 if (ssh->mainchan)
9285 ssh->send_ok = 1;
7cca0d81 9286 while (1) {
e5574168 9287 crReturnV;
51470298 9288 s->try_send = FALSE;
ff3187f6 9289 if (pktin) {
2b7540a7 9290
51df0ab5 9291 /*
9292 * _All_ the connection-layer packets we expect to
9293 * receive are now handled by the dispatch table.
9294 * Anything that reaches here must be bogus.
9295 */
32874aea 9296
51df0ab5 9297 bombout(("Strange packet received: type %d", pktin->type));
9298 crStopV;
0ed48730 9299 } else if (ssh->mainchan) {
32874aea 9300 /*
9301 * We have spare data. Add it to the channel buffer.
9302 */
d8baa528 9303 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 9304 s->try_send = TRUE;
32874aea 9305 }
51470298 9306 if (s->try_send) {
32874aea 9307 int i;
9308 struct ssh_channel *c;
9309 /*
9310 * Try to send data on all channels if we can.
9311 */
1bfc7e93 9312 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
78280721 9313 ssh2_try_send_and_unthrottle(ssh, c);
7cca0d81 9314 }
e5574168 9315 }
9316
9317 crFinishV;
9318}
9319
9320/*
2e85c969 9321 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 9322 */
409bfa77 9323static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 9324{
9325 /* log reason code in disconnect message */
9326 char *buf, *msg;
60860bc3 9327 int reason, msglen;
b09eaa88 9328
9329 reason = ssh_pkt_getuint32(pktin);
9330 ssh_pkt_getstring(pktin, &msg, &msglen);
9331
9332 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9333 buf = dupprintf("Received disconnect message (%s)",
9334 ssh2_disconnect_reasons[reason]);
9335 } else {
9336 buf = dupprintf("Received disconnect message (unknown"
9337 " type %d)", reason);
9338 }
9339 logevent(buf);
9340 sfree(buf);
60860bc3 9341 buf = dupprintf("Disconnection message text: %.*s",
9342 msglen, msg);
b09eaa88 9343 logevent(buf);
60860bc3 9344 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
b09eaa88 9345 reason,
9346 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9347 ssh2_disconnect_reasons[reason] : "unknown",
60860bc3 9348 msglen, msg));
b09eaa88 9349 sfree(buf);
9350}
9351
409bfa77 9352static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 9353{
9354 /* log the debug message */
fb983202 9355 char *msg;
b09eaa88 9356 int msglen;
b09eaa88 9357
3ab79841 9358 /* XXX maybe we should actually take notice of the return value */
9359 ssh2_pkt_getbool(pktin);
b09eaa88 9360 ssh_pkt_getstring(pktin, &msg, &msglen);
9361
fb983202 9362 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 9363}
9364
409bfa77 9365static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 9366{
9367 struct Packet *pktout;
9368 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9369 ssh2_pkt_adduint32(pktout, pktin->sequence);
9370 /*
9371 * UNIMPLEMENTED messages MUST appear in the same order as the
9372 * messages they respond to. Hence, never queue them.
9373 */
9374 ssh2_pkt_send_noqueue(ssh, pktout);
9375}
9376
9377/*
2e85c969 9378 * Handle the top-level SSH-2 protocol.
7cca0d81 9379 */
b09eaa88 9380static void ssh2_protocol_setup(Ssh ssh)
9381{
9382 int i;
9383
9384 /*
9385 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9386 */
9387 for (i = 0; i < 256; i++)
9388 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9389
9390 /*
9391 * Any message we actually understand, we set to NULL so that
9392 * the coroutines will get it.
9393 */
9394 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9395 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9396 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9397 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9398 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9399 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9400 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9401 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9402 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9403 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9404 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9405 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9406 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9407 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9408 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9409 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9410 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9411 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9412 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9413 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9414 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9415 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9416 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9417 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9418 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9419 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9420 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9421 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9422 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9423 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9424 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9425 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9426 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9427
9428 /*
9429 * These special message types we install handlers for.
9430 */
9431 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 9432 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 9433 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9434}
9435
9442dd57 9436static void ssh2_timer(void *ctx, long now)
9437{
9438 Ssh ssh = (Ssh)ctx;
9439
ecbb0000 9440 if (ssh->state == SSH_STATE_CLOSED)
9441 return;
9442
4a693cfc 9443 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9442dd57 9444 now - ssh->next_rekey >= 0) {
f382c87d 9445 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 9446 }
9447}
9448
1c1a7262 9449static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 9450 struct Packet *pktin)
7cca0d81 9451{
1c1a7262 9452 unsigned char *in = (unsigned char *)vin;
b09eaa88 9453 if (ssh->state == SSH_STATE_CLOSED)
9454 return;
9455
9442dd57 9456 if (pktin) {
9457 ssh->incoming_data_size += pktin->encrypted_len;
9458 if (!ssh->kex_in_progress &&
d57f70af 9459 ssh->max_data_size != 0 &&
9460 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9461 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 9462 }
9463
b09eaa88 9464 if (pktin && ssh->packet_dispatch[pktin->type]) {
9465 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 9466 return;
b09eaa88 9467 }
9468
9469 if (!ssh->protocol_initial_phase_done ||
9470 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9471 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9472 !ssh->protocol_initial_phase_done) {
9473 ssh->protocol_initial_phase_done = TRUE;
9474 /*
9475 * Allow authconn to initialise itself.
9476 */
9477 do_ssh2_authconn(ssh, NULL, 0, NULL);
9478 }
9479 } else {
9480 do_ssh2_authconn(ssh, in, inlen, pktin);
9481 }
7cca0d81 9482}
9483
4a693cfc 9484static void ssh_cache_conf_values(Ssh ssh)
9485{
9486 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9487}
9488
7cca0d81 9489/*
8df7a775 9490 * Called to set up the connection.
374330e2 9491 *
9492 * Returns an error message, or NULL on success.
374330e2 9493 */
cbe2d68f 9494static const char *ssh_init(void *frontend_handle, void **backend_handle,
4a693cfc 9495 Conf *conf, char *host, int port, char **realhost,
9496 int nodelay, int keepalive)
32874aea 9497{
cbe2d68f 9498 const char *p;
51470298 9499 Ssh ssh;
9500
3d88e64d 9501 ssh = snew(struct ssh_tag);
4a693cfc 9502 ssh->conf = conf_copy(conf);
9503 ssh_cache_conf_values(ssh);
125105d1 9504 ssh->version = 0; /* when not ready yet */
51470298 9505 ssh->s = NULL;
9506 ssh->cipher = NULL;
371e569c 9507 ssh->v1_cipher_ctx = NULL;
0183b242 9508 ssh->crcda_ctx = NULL;
51470298 9509 ssh->cscipher = NULL;
371e569c 9510 ssh->cs_cipher_ctx = NULL;
51470298 9511 ssh->sccipher = NULL;
371e569c 9512 ssh->sc_cipher_ctx = NULL;
51470298 9513 ssh->csmac = NULL;
a8327734 9514 ssh->cs_mac_ctx = NULL;
51470298 9515 ssh->scmac = NULL;
e0e1a00d 9516 ssh->sc_mac_ctx = NULL;
51470298 9517 ssh->cscomp = NULL;
5366aed8 9518 ssh->cs_comp_ctx = NULL;
51470298 9519 ssh->sccomp = NULL;
5366aed8 9520 ssh->sc_comp_ctx = NULL;
51470298 9521 ssh->kex = NULL;
389aa499 9522 ssh->kex_ctx = NULL;
51470298 9523 ssh->hostkey = NULL;
9524 ssh->exitcode = -1;
ac934965 9525 ssh->close_expected = FALSE;
9e296bfa 9526 ssh->clean_exit = FALSE;
51470298 9527 ssh->state = SSH_STATE_PREPACKET;
9528 ssh->size_needed = FALSE;
9529 ssh->eof_needed = FALSE;
b9d7bcad 9530 ssh->ldisc = NULL;
a8327734 9531 ssh->logctx = NULL;
51470298 9532 ssh->deferred_send_data = NULL;
9533 ssh->deferred_len = 0;
9534 ssh->deferred_size = 0;
9535 ssh->fallback_cmd = 0;
acab36bc 9536 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9537 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8def70c3 9538 ssh->x11disp = NULL;
be738459 9539 ssh->v1_compressing = FALSE;
51470298 9540 ssh->v2_outgoing_sequence = 0;
9541 ssh->ssh1_rdpkt_crstate = 0;
9542 ssh->ssh2_rdpkt_crstate = 0;
9543 ssh->do_ssh_init_crstate = 0;
9544 ssh->ssh_gotdata_crstate = 0;
b09eaa88 9545 ssh->do_ssh1_connection_crstate = 0;
51470298 9546 ssh->do_ssh1_login_crstate = 0;
9547 ssh->do_ssh2_transport_crstate = 0;
9548 ssh->do_ssh2_authconn_crstate = 0;
9549 ssh->do_ssh_init_state = NULL;
9550 ssh->do_ssh1_login_state = NULL;
9551 ssh->do_ssh2_transport_state = NULL;
9552 ssh->do_ssh2_authconn_state = NULL;
4320baf7 9553 ssh->v_c = NULL;
9554 ssh->v_s = NULL;
6571dbfd 9555 ssh->mainchan = NULL;
968d2d92 9556 ssh->throttled_all = 0;
9557 ssh->v1_stdout_throttling = 0;
590f6a5f 9558 ssh->queue = NULL;
9559 ssh->queuelen = ssh->queuesize = 0;
9560 ssh->queueing = FALSE;
06fadff5 9561 ssh->qhead = ssh->qtail = NULL;
e13bba36 9562 ssh->deferred_rekey_reason = NULL;
3d9449a1 9563 bufchain_init(&ssh->queued_incoming_data);
9564 ssh->frozen = FALSE;
4a693cfc 9565 ssh->username = NULL;
bc06669b 9566 ssh->sent_console_eof = FALSE;
4a202fc6 9567 ssh->got_pty = FALSE;
51470298 9568
9569 *backend_handle = ssh;
32874aea 9570
8f203108 9571#ifdef MSCRYPTOAPI
32874aea 9572 if (crypto_startup() == 0)
8f203108 9573 return "Microsoft high encryption pack not installed!";
9574#endif
374330e2 9575
51470298 9576 ssh->frontend = frontend_handle;
4a693cfc 9577 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9578 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
887035a5 9579
fabd1805 9580 ssh->channels = NULL;
9581 ssh->rportfwds = NULL;
f47a5ffb 9582 ssh->portfwds = NULL;
fabd1805 9583
51470298 9584 ssh->send_ok = 0;
9585 ssh->editing = 0;
9586 ssh->echoing = 0;
ff68564b 9587 ssh->conn_throttle_count = 0;
51470298 9588 ssh->overall_bufsize = 0;
9589 ssh->fallback_cmd = 0;
8df7a775 9590
3648d4c5 9591 ssh->protocol = NULL;
9592
b09eaa88 9593 ssh->protocol_initial_phase_done = FALSE;
9594
39934deb 9595 ssh->pinger = NULL;
9596
9442dd57 9597 ssh->incoming_data_size = ssh->outgoing_data_size =
9598 ssh->deferred_data_size = 0L;
4a693cfc 9599 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9600 CONF_ssh_rekey_data));
9442dd57 9601 ssh->kex_in_progress = FALSE;
9602
1e00c92b 9603#ifndef NO_GSSAPI
9604 ssh->gsslibs = NULL;
9605#endif
9606
79bf227b 9607 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 9608 if (p != NULL)
9609 return p;
374330e2 9610
5d17ccfc 9611 random_ref();
9612
374330e2 9613 return NULL;
9614}
9615
fabd1805 9616static void ssh_free(void *handle)
9617{
9618 Ssh ssh = (Ssh) handle;
9619 struct ssh_channel *c;
9620 struct ssh_rportfwd *pf;
9621
9622 if (ssh->v1_cipher_ctx)
9623 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9624 if (ssh->cs_cipher_ctx)
9625 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9626 if (ssh->sc_cipher_ctx)
9627 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9628 if (ssh->cs_mac_ctx)
9629 ssh->csmac->free_context(ssh->cs_mac_ctx);
9630 if (ssh->sc_mac_ctx)
9631 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 9632 if (ssh->cs_comp_ctx) {
9633 if (ssh->cscomp)
9634 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9635 else
9636 zlib_compress_cleanup(ssh->cs_comp_ctx);
9637 }
9638 if (ssh->sc_comp_ctx) {
9639 if (ssh->sccomp)
9640 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9641 else
9642 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9643 }
fabd1805 9644 if (ssh->kex_ctx)
9645 dh_cleanup(ssh->kex_ctx);
9646 sfree(ssh->savedhost);
9647
590f6a5f 9648 while (ssh->queuelen-- > 0)
9649 ssh_free_packet(ssh->queue[ssh->queuelen]);
9650 sfree(ssh->queue);
9651
06fadff5 9652 while (ssh->qhead) {
9653 struct queued_handler *qh = ssh->qhead;
9654 ssh->qhead = qh->next;
9655 sfree(ssh->qhead);
9656 }
9657 ssh->qhead = ssh->qtail = NULL;
9658
fabd1805 9659 if (ssh->channels) {
9660 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9661 switch (c->type) {
9662 case CHAN_X11:
9663 if (c->u.x11.s != NULL)
9664 x11_close(c->u.x11.s);
9665 break;
9666 case CHAN_SOCKDATA:
409eca86 9667 case CHAN_SOCKDATA_DORMANT:
fabd1805 9668 if (c->u.pfd.s != NULL)
9669 pfd_close(c->u.pfd.s);
9670 break;
9671 }
9672 sfree(c);
9673 }
9674 freetree234(ssh->channels);
cdb52705 9675 ssh->channels = NULL;
fabd1805 9676 }
9677
9678 if (ssh->rportfwds) {
9679 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8aea57fd 9680 free_rportfwd(pf);
fabd1805 9681 freetree234(ssh->rportfwds);
cdb52705 9682 ssh->rportfwds = NULL;
fabd1805 9683 }
9684 sfree(ssh->deferred_send_data);
8def70c3 9685 if (ssh->x11disp)
9686 x11_free_display(ssh->x11disp);
fabd1805 9687 sfree(ssh->do_ssh_init_state);
9688 sfree(ssh->do_ssh1_login_state);
9689 sfree(ssh->do_ssh2_transport_state);
9690 sfree(ssh->do_ssh2_authconn_state);
4320baf7 9691 sfree(ssh->v_c);
9692 sfree(ssh->v_s);
42af6a67 9693 sfree(ssh->fullhostname);
679539d7 9694 if (ssh->crcda_ctx) {
9695 crcda_free_context(ssh->crcda_ctx);
9696 ssh->crcda_ctx = NULL;
9697 }
fabd1805 9698 if (ssh->s)
ac934965 9699 ssh_do_close(ssh, TRUE);
9442dd57 9700 expire_timer_context(ssh);
39934deb 9701 if (ssh->pinger)
9702 pinger_free(ssh->pinger);
3d9449a1 9703 bufchain_clear(&ssh->queued_incoming_data);
4a693cfc 9704 sfree(ssh->username);
9705 conf_free(ssh->conf);
1e00c92b 9706#ifndef NO_GSSAPI
9707 if (ssh->gsslibs)
9708 ssh_gss_cleanup(ssh->gsslibs);
9709#endif
ee50e8b6 9710 sfree(ssh);
5d17ccfc 9711
9712 random_unref();
fabd1805 9713}
9714
374330e2 9715/*
86916870 9716 * Reconfigure the SSH backend.
86916870 9717 */
4a693cfc 9718static void ssh_reconfig(void *handle, Conf *conf)
86916870 9719{
9720 Ssh ssh = (Ssh) handle;
e13bba36 9721 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 9722 unsigned long old_max_data_size;
4a693cfc 9723 int i, rekey_time;
e6c1536e 9724
4a693cfc 9725 pinger_reconfig(ssh->pinger, ssh->conf, conf);
3b6606c7 9726 if (ssh->portfwds)
4a693cfc 9727 ssh_setup_portfwd(ssh, conf);
e6c1536e 9728
4a693cfc 9729 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9730 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9731 rekey_time != 0) {
9732 long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
e6c1536e 9733 long now = GETTICKCOUNT();
9734
9735 if (new_next - now < 0) {
f382c87d 9736 rekeying = "timeout shortened";
e6c1536e 9737 } else {
9738 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9739 }
9740 }
9741
9742 old_max_data_size = ssh->max_data_size;
4a693cfc 9743 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9744 CONF_ssh_rekey_data));
e6c1536e 9745 if (old_max_data_size != ssh->max_data_size &&
9746 ssh->max_data_size != 0) {
9747 if (ssh->outgoing_data_size > ssh->max_data_size ||
9748 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9749 rekeying = "data limit lowered";
e6c1536e 9750 }
9751
4a693cfc 9752 if (conf_get_int(ssh->conf, CONF_compression) !=
9753 conf_get_int(conf, CONF_compression)) {
f382c87d 9754 rekeying = "compression setting changed";
e13bba36 9755 rekey_mandatory = TRUE;
9756 }
9757
4a693cfc 9758 for (i = 0; i < CIPHER_MAX; i++)
9759 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9760 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9761 rekeying = "cipher settings changed";
9762 rekey_mandatory = TRUE;
9763 }
9764 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9765 conf_get_int(conf, CONF_ssh2_des_cbc)) {
f382c87d 9766 rekeying = "cipher settings changed";
e13bba36 9767 rekey_mandatory = TRUE;
e6c1536e 9768 }
9769
4a693cfc 9770 conf_free(ssh->conf);
9771 ssh->conf = conf_copy(conf);
9772 ssh_cache_conf_values(ssh);
e13bba36 9773
9774 if (rekeying) {
9775 if (!ssh->kex_in_progress) {
9776 do_ssh2_transport(ssh, rekeying, -1, NULL);
9777 } else if (rekey_mandatory) {
9778 ssh->deferred_rekey_reason = rekeying;
9779 }
9780 }
86916870 9781}
9782
9783/*
86dc445a 9784 * Called to send data down the SSH connection.
374330e2 9785 */
51470298 9786static int ssh_send(void *handle, char *buf, int len)
32874aea 9787{
51470298 9788 Ssh ssh = (Ssh) handle;
9789
9790 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9791 return 0;
374330e2 9792
d8baa528 9793 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 9794
51470298 9795 return ssh_sendbuffer(ssh);
5471d09a 9796}
9797
9798/*
9799 * Called to query the current amount of buffered stdin data.
9800 */
51470298 9801static int ssh_sendbuffer(void *handle)
5471d09a 9802{
51470298 9803 Ssh ssh = (Ssh) handle;
5471d09a 9804 int override_value;
9805
51470298 9806 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9807 return 0;
9808
9809 /*
9810 * If the SSH socket itself has backed up, add the total backup
9811 * size on that to any individual buffer on the stdin channel.
9812 */
9813 override_value = 0;
51470298 9814 if (ssh->throttled_all)
9815 override_value = ssh->overall_bufsize;
5471d09a 9816
51470298 9817 if (ssh->version == 1) {
5471d09a 9818 return override_value;
51470298 9819 } else if (ssh->version == 2) {
bc06669b 9820 if (!ssh->mainchan)
5471d09a 9821 return override_value;
9822 else
51470298 9823 return (override_value +
9824 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 9825 }
9826
9827 return 0;
374330e2 9828}
9829
9830/*
6e48c3fe 9831 * Called to set the size of the window from SSH's POV.
374330e2 9832 */
51470298 9833static void ssh_size(void *handle, int width, int height)
32874aea 9834{
51470298 9835 Ssh ssh = (Ssh) handle;
ff3187f6 9836 struct Packet *pktout;
51470298 9837
9838 ssh->term_width = width;
9839 ssh->term_height = height;
f278d6f8 9840
51470298 9841 switch (ssh->state) {
374330e2 9842 case SSH_STATE_BEFORE_SIZE:
3687d221 9843 case SSH_STATE_PREPACKET:
21248260 9844 case SSH_STATE_CLOSED:
374330e2 9845 break; /* do nothing */
9846 case SSH_STATE_INTERMED:
51470298 9847 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9848 break;
9849 case SSH_STATE_SESSION:
4a693cfc 9850 if (!conf_get_int(ssh->conf, CONF_nopty)) {
51470298 9851 if (ssh->version == 1) {
9852 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9853 PKT_INT, ssh->term_height,
9854 PKT_INT, ssh->term_width,
32874aea 9855 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9856 } else if (ssh->mainchan) {
ff3187f6 9857 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9858 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9859 ssh2_pkt_addstring(pktout, "window-change");
9860 ssh2_pkt_addbool(pktout, 0);
9861 ssh2_pkt_adduint32(pktout, ssh->term_width);
9862 ssh2_pkt_adduint32(pktout, ssh->term_height);
9863 ssh2_pkt_adduint32(pktout, 0);
9864 ssh2_pkt_adduint32(pktout, 0);
9865 ssh2_pkt_send(ssh, pktout);
32874aea 9866 }
9867 }
9868 break;
374330e2 9869 }
9870}
9871
9872/*
125105d1 9873 * Return a list of the special codes that make sense in this
9874 * protocol.
9875 */
9876static const struct telnet_special *ssh_get_specials(void *handle)
9877{
786ba75e 9878 static const struct telnet_special ssh1_ignore_special[] = {
9879 {"IGNORE message", TS_NOP}
9880 };
cf6ddb95 9881 static const struct telnet_special ssh2_ignore_special[] = {
62638676 9882 {"IGNORE message", TS_NOP},
cf6ddb95 9883 };
9884 static const struct telnet_special ssh2_rekey_special[] = {
9442dd57 9885 {"Repeat key exchange", TS_REKEY},
62638676 9886 };
9887 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 9888 {NULL, TS_SEP},
9889 {"Break", TS_BRK},
bccbeb71 9890 /* These are the signal names defined by RFC 4254.
6f2d0cde 9891 * They include all the ISO C signals, but are a subset of the POSIX
9892 * required signals. */
9893 {"SIGINT (Interrupt)", TS_SIGINT},
9894 {"SIGTERM (Terminate)", TS_SIGTERM},
9895 {"SIGKILL (Kill)", TS_SIGKILL},
9896 {"SIGQUIT (Quit)", TS_SIGQUIT},
9897 {"SIGHUP (Hangup)", TS_SIGHUP},
9898 {"More signals", TS_SUBMENU},
9899 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9900 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9901 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9902 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9903 {NULL, TS_EXITMENU}
62638676 9904 };
9905 static const struct telnet_special specials_end[] = {
6f2d0cde 9906 {NULL, TS_EXITMENU}
62638676 9907 };
786ba75e 9908 /* XXX review this length for any changes: */
cf6ddb95 9909 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9910 lenof(ssh2_rekey_special) +
62638676 9911 lenof(ssh2_session_specials) +
9912 lenof(specials_end)];
125105d1 9913 Ssh ssh = (Ssh) handle;
62638676 9914 int i = 0;
9915#define ADD_SPECIALS(name) \
9916 do { \
9917 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9918 memcpy(&ssh_specials[i], name, sizeof name); \
9919 i += lenof(name); \
9920 } while(0)
125105d1 9921
9922 if (ssh->version == 1) {
62638676 9923 /* Don't bother offering IGNORE if we've decided the remote
9924 * won't cope with it, since we wouldn't bother sending it if
9925 * asked anyway. */
9926 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 9927 ADD_SPECIALS(ssh1_ignore_special);
125105d1 9928 } else if (ssh->version == 2) {
cf6ddb95 9929 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9930 ADD_SPECIALS(ssh2_ignore_special);
9931 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9932 ADD_SPECIALS(ssh2_rekey_special);
62638676 9933 if (ssh->mainchan)
9934 ADD_SPECIALS(ssh2_session_specials);
9935 } /* else we're not ready yet */
9936
9937 if (i) {
9938 ADD_SPECIALS(specials_end);
9939 return ssh_specials;
9940 } else {
125105d1 9941 return NULL;
62638676 9942 }
9943#undef ADD_SPECIALS
125105d1 9944}
9945
9946/*
86dc445a 9947 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 9948 * can send an EOF and collect resulting output (e.g. `plink
9949 * hostname sort').
374330e2 9950 */
51470298 9951static void ssh_special(void *handle, Telnet_Special code)
32874aea 9952{
51470298 9953 Ssh ssh = (Ssh) handle;
ff3187f6 9954 struct Packet *pktout;
51470298 9955
6abbf9e3 9956 if (code == TS_EOF) {
51470298 9957 if (ssh->state != SSH_STATE_SESSION) {
32874aea 9958 /*
9959 * Buffer the EOF in case we are pre-SESSION, so we can
9960 * send it as soon as we reach SESSION.
9961 */
9962 if (code == TS_EOF)
51470298 9963 ssh->eof_needed = TRUE;
32874aea 9964 return;
9965 }
51470298 9966 if (ssh->version == 1) {
9967 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 9968 } else if (ssh->mainchan) {
bc06669b 9969 sshfwd_write_eof(ssh->mainchan);
00a0b113 9970 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 9971 }
9972 logevent("Sent EOF message");
125105d1 9973 } else if (code == TS_PING || code == TS_NOP) {
51470298 9974 if (ssh->state == SSH_STATE_CLOSED
9975 || ssh->state == SSH_STATE_PREPACKET) return;
9976 if (ssh->version == 1) {
9977 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9978 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 9979 } else {
cf6ddb95 9980 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9981 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9982 ssh2_pkt_addstring_start(pktout);
9983 ssh2_pkt_send_noqueue(ssh, pktout);
9984 }
32874aea 9985 }
9442dd57 9986 } else if (code == TS_REKEY) {
9987 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 9988 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 9989 }
125105d1 9990 } else if (code == TS_BRK) {
9991 if (ssh->state == SSH_STATE_CLOSED
9992 || ssh->state == SSH_STATE_PREPACKET) return;
9993 if (ssh->version == 1) {
2e85c969 9994 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 9995 } else if (ssh->mainchan) {
ff3187f6 9996 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9997 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9998 ssh2_pkt_addstring(pktout, "break");
9999 ssh2_pkt_addbool(pktout, 0);
10000 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10001 ssh2_pkt_send(ssh, pktout);
125105d1 10002 }
6abbf9e3 10003 } else {
6f2d0cde 10004 /* Is is a POSIX signal? */
10005 char *signame = NULL;
10006 if (code == TS_SIGABRT) signame = "ABRT";
10007 if (code == TS_SIGALRM) signame = "ALRM";
10008 if (code == TS_SIGFPE) signame = "FPE";
10009 if (code == TS_SIGHUP) signame = "HUP";
10010 if (code == TS_SIGILL) signame = "ILL";
10011 if (code == TS_SIGINT) signame = "INT";
10012 if (code == TS_SIGKILL) signame = "KILL";
10013 if (code == TS_SIGPIPE) signame = "PIPE";
10014 if (code == TS_SIGQUIT) signame = "QUIT";
10015 if (code == TS_SIGSEGV) signame = "SEGV";
10016 if (code == TS_SIGTERM) signame = "TERM";
10017 if (code == TS_SIGUSR1) signame = "USR1";
10018 if (code == TS_SIGUSR2) signame = "USR2";
10019 /* The SSH-2 protocol does in principle support arbitrary named
10020 * signals, including signame@domain, but we don't support those. */
10021 if (signame) {
10022 /* It's a signal. */
10023 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 10024 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
10025 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
10026 ssh2_pkt_addstring(pktout, "signal");
10027 ssh2_pkt_addbool(pktout, 0);
10028 ssh2_pkt_addstring(pktout, signame);
10029 ssh2_pkt_send(ssh, pktout);
6f2d0cde 10030 logeventf(ssh, "Sent signal SIG%s", signame);
10031 }
10032 } else {
10033 /* Never heard of it. Do nothing */
10034 }
6abbf9e3 10035 }
374330e2 10036}
10037
51470298 10038void *new_sock_channel(void *handle, Socket s)
d74d141c 10039{
51470298 10040 Ssh ssh = (Ssh) handle;
d74d141c 10041 struct ssh_channel *c;
3d88e64d 10042 c = snew(struct ssh_channel);
d74d141c 10043
70c0cbe1 10044 c->ssh = ssh;
10045 ssh2_channel_init(c);
10046 c->halfopen = TRUE;
10047 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10048 c->u.pfd.s = s;
10049 add234(ssh->channels, c);
d74d141c 10050 return c;
10051}
10052
5471d09a 10053/*
10054 * This is called when stdout/stderr (the entity to which
10055 * from_backend sends data) manages to clear some backlog.
10056 */
ae9ae89f 10057static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 10058{
51470298 10059 Ssh ssh = (Ssh) handle;
ff68564b 10060 int buflimit;
10061
51470298 10062 if (ssh->version == 1) {
10063 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10064 ssh->v1_stdout_throttling = 0;
ff68564b 10065 ssh_throttle_conn(ssh, -1);
5471d09a 10066 }
10067 } else {
ff68564b 10068 if (ssh->mainchan) {
ab87bf1d 10069 ssh2_set_window(ssh->mainchan,
ff68564b 10070 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10071 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
4a693cfc 10072 if (conf_get_int(ssh->conf, CONF_ssh_simple))
ff68564b 10073 buflimit = 0;
10074 else
10075 buflimit = ssh->mainchan->v.v2.locmaxwin;
10076 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10077 ssh->mainchan->throttling_conn = 0;
10078 ssh_throttle_conn(ssh, -1);
10079 }
10080 }
5471d09a 10081 }
78e71de1 10082
10083 /*
10084 * Now process any SSH connection data that was stashed in our
10085 * queue while we were frozen.
10086 */
10087 ssh_process_queued_incoming_data(ssh);
5471d09a 10088}
10089
6b78788a 10090void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 10091{
10092 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 10093 Ssh ssh = c->ssh;
ff3187f6 10094 struct Packet *pktout;
d74d141c 10095
57356d63 10096 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 10097
51470298 10098 if (ssh->version == 1) {
10099 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 10100 PKT_INT, c->localid,
10101 PKT_STR, hostname,
10102 PKT_INT, port,
31fb1866 10103 /* PKT_STR, <org:orgport>, */
bc240b21 10104 PKT_END);
10105 } else {
ff3187f6 10106 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
10107 ssh2_pkt_addstring(pktout, "direct-tcpip");
10108 ssh2_pkt_adduint32(pktout, c->localid);
ff3187f6 10109 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 10110 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 10111 ssh2_pkt_addstring(pktout, hostname);
10112 ssh2_pkt_adduint32(pktout, port);
bc240b21 10113 /*
10114 * We make up values for the originator data; partly it's
10115 * too much hassle to keep track, and partly I'm not
10116 * convinced the server should be told details like that
10117 * about my local network configuration.
1f182589 10118 * The "originator IP address" is syntactically a numeric
10119 * IP address, and some servers (e.g., Tectia) get upset
10120 * if it doesn't match this syntax.
bc240b21 10121 */
1f182589 10122 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 10123 ssh2_pkt_adduint32(pktout, 0);
10124 ssh2_pkt_send(ssh, pktout);
bc240b21 10125 }
d74d141c 10126}
10127
6226c939 10128static int ssh_connected(void *handle)
32874aea 10129{
51470298 10130 Ssh ssh = (Ssh) handle;
6226c939 10131 return ssh->s != NULL;
32874aea 10132}
8ccc75b0 10133
51470298 10134static int ssh_sendok(void *handle)
32874aea 10135{
51470298 10136 Ssh ssh = (Ssh) handle;
10137 return ssh->send_ok;
32874aea 10138}
fb09bf1c 10139
51470298 10140static int ssh_ldisc(void *handle, int option)
32874aea 10141{
51470298 10142 Ssh ssh = (Ssh) handle;
32874aea 10143 if (option == LD_ECHO)
51470298 10144 return ssh->echoing;
32874aea 10145 if (option == LD_EDIT)
51470298 10146 return ssh->editing;
0965bee0 10147 return FALSE;
10148}
10149
b9d7bcad 10150static void ssh_provide_ldisc(void *handle, void *ldisc)
10151{
10152 Ssh ssh = (Ssh) handle;
10153 ssh->ldisc = ldisc;
10154}
10155
a8327734 10156static void ssh_provide_logctx(void *handle, void *logctx)
10157{
10158 Ssh ssh = (Ssh) handle;
10159 ssh->logctx = logctx;
10160}
10161
51470298 10162static int ssh_return_exitcode(void *handle)
10163{
10164 Ssh ssh = (Ssh) handle;
3bb2f322 10165 if (ssh->s != NULL)
10166 return -1;
10167 else
3c112d53 10168 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 10169}
10170
10171/*
f89c3294 10172 * cfg_info for SSH is the currently running version of the
10173 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10174 */
10175static int ssh_cfg_info(void *handle)
10176{
10177 Ssh ssh = (Ssh) handle;
10178 return ssh->version;
10179}
10180
10181/*
51470298 10182 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10183 * that fails. This variable is the means by which scp.c can reach
10184 * into the SSH code and find out which one it got.
10185 */
10186extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 10187{
51470298 10188 Ssh ssh = (Ssh) handle;
10189 return ssh->fallback_cmd;
d8d6c7e5 10190}
10191
374330e2 10192Backend ssh_backend = {
10193 ssh_init,
fabd1805 10194 ssh_free,
86916870 10195 ssh_reconfig,
374330e2 10196 ssh_send,
5471d09a 10197 ssh_sendbuffer,
374330e2 10198 ssh_size,
4017be6d 10199 ssh_special,
125105d1 10200 ssh_get_specials,
6226c939 10201 ssh_connected,
d8d6c7e5 10202 ssh_return_exitcode,
97db3be4 10203 ssh_sendok,
0965bee0 10204 ssh_ldisc,
b9d7bcad 10205 ssh_provide_ldisc,
a8327734 10206 ssh_provide_logctx,
5471d09a 10207 ssh_unthrottle,
f89c3294 10208 ssh_cfg_info,
9e164d82 10209 "ssh",
10210 PROT_SSH,
97db3be4 10211 22
bc240b21 10212};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator