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Increase FONT_MAXNO from 0x2f to 0x40, to ensure the fonts[] array
[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:;
30919997 434#define crBeginState crBegin(s->crLine)
435#define crStateP(t, v) \
436 struct t *s; \
437 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
438 s = (v);
439#define crState(t) crStateP(t, ssh->t)
51470298 440#define crFinish(z) } *crLine = 0; return (z); }
441#define crFinishV } *crLine = 0; return; }
0d201bfb 442#define crFinishFree(z) } sfree(s); return (z); }
443#define crFinishFreeV } sfree(s); return; }
374330e2 444#define crReturn(z) \
445 do {\
51470298 446 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 447 } while (0)
448#define crReturnV \
449 do {\
51470298 450 *crLine=__LINE__; return; case __LINE__:;\
374330e2 451 } while (0)
51470298 452#define crStop(z) do{ *crLine = 0; return (z); }while(0)
453#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 454#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 455#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 456
51470298 457typedef struct ssh_tag *Ssh;
ff3187f6 458struct Packet;
459
dacd8872 460static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 461static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 462static void ssh_pkt_ensure(struct Packet *, int length);
463static void ssh_pkt_adddata(struct Packet *, void *data, int len);
464static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 465static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 466static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
467static void ssh_pkt_addstring_start(struct Packet *);
468static void ssh_pkt_addstring_str(struct Packet *, char *data);
469static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
470static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 471static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 472static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 473static void ssh2_pkt_addmp(struct Packet *, Bignum b);
474static int ssh2_pkt_construct(Ssh, struct Packet *);
475static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 476static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 477static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
478 struct Packet *pktin);
479static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
480 struct Packet *pktin);
997097db 481static void ssh2_channel_check_close(struct ssh_channel *c);
bc06669b 482static void ssh_channel_destroy(struct ssh_channel *c);
3d63ca2e 483
5471d09a 484/*
485 * Buffer management constants. There are several of these for
486 * various different purposes:
487 *
488 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
489 * on a local data stream before we throttle the whole SSH
2e85c969 490 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 491 * pretty drastic so we set this high in the hope it won't
492 * happen very often.
493 *
494 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
495 * on the SSH connection itself before we defensively throttle
496 * _all_ local data streams. This is pretty drastic too (though
2e85c969 497 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 498 * ensure that the server never has any need to throttle its end
499 * of the connection), so we set this high as well.
500 *
2e85c969 501 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 502 * channels.
9b53e9b8 503 *
504 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 505 * channel in a simple connection. It must be <= INT_MAX.
9916cc1e 506 *
507 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
508 * to the remote side. This actually has nothing to do with the
509 * size of the _packet_, but is instead a limit on the amount
510 * of data we're willing to receive in a single SSH2 channel
511 * data message.
512 *
513 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
514 * _packet_ we're prepared to cope with. It must be a multiple
515 * of the cipher block size, and must be at least 35000.
5471d09a 516 */
517
518#define SSH1_BUFFER_LIMIT 32768
519#define SSH_MAX_BACKLOG 32768
520#define OUR_V2_WINSIZE 16384
3361b80a 521#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 522#define OUR_V2_MAXPKT 0x4000UL
9916cc1e 523#define OUR_V2_PACKETLIMIT 0x9000UL
d74d141c 524
85cc02bb 525const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 526
8b2715b2 527const static struct ssh_mac *macs[] = {
23159902 528 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 529};
8b2715b2 530const static struct ssh_mac *buggymacs[] = {
6668a75e 531 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 532};
e5574168 533
5366aed8 534static void *ssh_comp_none_init(void)
535{
536 return NULL;
537}
538static void ssh_comp_none_cleanup(void *handle)
32874aea 539{
540}
5366aed8 541static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 542 unsigned char **outblock, int *outlen)
543{
544 return 0;
545}
5366aed8 546static int ssh_comp_none_disable(void *handle)
32874aea 547{
4ba9b64b 548 return 0;
549}
57476f6b 550const static struct ssh_compress ssh_comp_none = {
ab18ccff 551 "none", NULL,
5366aed8 552 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
553 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
554 ssh_comp_none_disable, NULL
e5574168 555};
4ba9b64b 556extern const struct ssh_compress ssh_zlib;
557const static struct ssh_compress *compressions[] = {
32874aea 558 &ssh_zlib, &ssh_comp_none
559};
374330e2 560
32874aea 561enum { /* channel types */
783415f8 562 CHAN_MAINSESSION,
563 CHAN_X11,
564 CHAN_AGENT,
bc240b21 565 CHAN_SOCKDATA,
c6b41791 566 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
567 /*
568 * CHAN_ZOMBIE is used to indicate a channel for which we've
569 * already destroyed the local data source: for instance, if a
570 * forwarded port experiences a socket error on the local side, we
571 * immediately destroy its local socket and turn the SSH channel
572 * into CHAN_ZOMBIE.
573 */
574 CHAN_ZOMBIE
783415f8 575};
576
39d830e4 577typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
578typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
579typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
580
581/*
582 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
583 * handlers.
584 */
585struct outstanding_channel_request {
586 cchandler_fn_t handler;
587 void *ctx;
588 struct outstanding_channel_request *next;
589};
590
dacbd0e8 591/*
592 * 2-3-4 tree storing channels.
593 */
594struct ssh_channel {
51470298 595 Ssh ssh; /* pointer back to main context */
d211621f 596 unsigned remoteid, localid;
dacbd0e8 597 int type;
64d6ff88 598 /* True if we opened this channel but server hasn't confirmed. */
599 int halfopen;
0357890f 600 /*
2e85c969 601 * In SSH-1, this value contains four bits:
0357890f 602 *
603 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
604 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
605 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
606 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
607 *
608 * A channel is completely finished with when all four bits are set.
bc06669b 609 *
610 * In SSH-2, the four bits mean:
611 *
612 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
613 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
614 * 4 We have received SSH2_MSG_CHANNEL_EOF.
615 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
616 *
617 * A channel is completely finished with when we have both sent
618 * and received CLOSE.
619 *
620 * The symbolic constants below use the SSH-2 terminology, which
621 * is a bit confusing in SSH-1, but we have to use _something_.
0357890f 622 */
bc06669b 623#define CLOSES_SENT_EOF 1
624#define CLOSES_SENT_CLOSE 2
625#define CLOSES_RCVD_EOF 4
626#define CLOSES_RCVD_CLOSE 8
dacbd0e8 627 int closes;
78280721 628
629 /*
bc06669b 630 * This flag indicates that an EOF is pending on the outgoing side
631 * of the channel: that is, wherever we're getting the data for
632 * this channel has sent us some data followed by EOF. We can't
633 * actually send the EOF until we've finished sending the data, so
634 * we set this flag instead to remind us to do so once our buffer
635 * is clear.
78280721 636 */
bc06669b 637 int pending_eof;
78280721 638
ff68564b 639 /*
640 * True if this channel is causing the underlying connection to be
641 * throttled.
642 */
643 int throttling_conn;
5471d09a 644 union {
5471d09a 645 struct ssh2_data_channel {
646 bufchain outbuffer;
647 unsigned remwindow, remmaxpkt;
467e064d 648 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 649 int locwindow, locmaxwin;
0e443c99 650 /*
651 * remlocwin is the amount of local window that we think
652 * the remote end had available to it after it sent the
653 * last data packet or window adjust ack.
654 */
655 int remlocwin;
656 /*
39d830e4 657 * These store the list of channel requests that haven't
0e443c99 658 * been acked.
659 */
39d830e4 660 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
0e443c99 661 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 662 } v2;
663 } v;
dacbd0e8 664 union {
32874aea 665 struct ssh_agent_channel {
666 unsigned char *message;
667 unsigned char msglen[4];
a03c9f9c 668 unsigned lensofar, totallen;
be3f980d 669 int outstanding_requests;
32874aea 670 } a;
671 struct ssh_x11_channel {
672 Socket s;
673 } x11;
d74d141c 674 struct ssh_pfd_channel {
675 Socket s;
676 } pfd;
dacbd0e8 677 } u;
678};
57476f6b 679
d74d141c 680/*
2e85c969 681 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
682 * use this structure in different ways, reflecting SSH-2's
bc240b21 683 * altogether saner approach to port forwarding.
684 *
2e85c969 685 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 686 * the remote port number, and the local destination host:port.
687 * When a connection comes in, the server sends you back that
688 * host:port pair, and you connect to it. This is a ready-made
689 * security hole if you're not on the ball: a malicious server
690 * could send you back _any_ host:port pair, so if you trustingly
691 * connect to the address it gives you then you've just opened the
692 * entire inside of your corporate network just by connecting
693 * through it to a dodgy SSH server. Hence, we must store a list of
694 * host:port pairs we _are_ trying to forward to, and reject a
695 * connection request from the server if it's not in the list.
696 *
2e85c969 697 * In SSH-2, each side of the connection minds its own business and
bc240b21 698 * doesn't send unnecessary information to the other. You arrange a
699 * remote forwarding by sending the server just the remote port
700 * number. When a connection comes in, the server tells you which
701 * of its ports was connected to; and _you_ have to remember what
702 * local host:port pair went with that port number.
703 *
2e85c969 704 * Hence, in SSH-1 this structure is indexed by destination
705 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 706 */
fda2feb1 707struct ssh_portfwd; /* forward declaration */
708
d74d141c 709struct ssh_rportfwd {
bc240b21 710 unsigned sport, dport;
711 char dhost[256];
06fadff5 712 char *sportdesc;
fda2feb1 713 struct ssh_portfwd *pfrec;
d74d141c 714};
fda2feb1 715#define free_rportfwd(pf) ( \
716 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
717
718/*
719 * Separately to the rportfwd tree (which is for looking up port
720 * open requests from the server), a tree of _these_ structures is
721 * used to keep track of all the currently open port forwardings,
722 * so that we can reconfigure in mid-session if the user requests
723 * it.
724 */
725struct ssh_portfwd {
84328ddb 726 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 727 int type;
728 unsigned sport, dport;
729 char *saddr, *daddr;
3fe92132 730 char *sserv, *dserv;
fda2feb1 731 struct ssh_rportfwd *remote;
05581745 732 int addressfamily;
fda2feb1 733 void *local;
734};
735#define free_portfwd(pf) ( \
3fe92132 736 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
737 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 738
57476f6b 739struct Packet {
dacd8872 740 long length; /* length of `data' actually used */
741 long forcepad; /* SSH-2: force padding to at least this length */
742 int type; /* only used for incoming packets */
743 unsigned long sequence; /* SSH-2 incoming sequence number */
744 unsigned char *data; /* allocated storage */
745 unsigned char *body; /* offset of payload within `data' */
746 long savedpos; /* temporary index into `data' (for strings) */
747 long maxlen; /* amount of storage allocated for `data' */
748 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 749
750 /*
751 * State associated with packet logging
752 */
753 int logmode;
754 int nblanks;
755 struct logblank_t *blanks;
57476f6b 756};
757
1c1a7262 758static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 759 struct Packet *pktin);
1c1a7262 760static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 761 struct Packet *pktin);
b09eaa88 762static void ssh1_protocol_setup(Ssh ssh);
763static void ssh2_protocol_setup(Ssh ssh);
51470298 764static void ssh_size(void *handle, int width, int height);
765static void ssh_special(void *handle, Telnet_Special);
5471d09a 766static int ssh2_try_send(struct ssh_channel *c);
51470298 767static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
768static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 769static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 770static int ssh_sendbuffer(void *handle);
ac934965 771static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 772static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
773static int ssh2_pkt_getbool(struct Packet *pkt);
774static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
d719927e 775static void ssh2_timer(void *ctx, unsigned long now);
0b106f61 776static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
777 struct Packet *pktin);
39d830e4 778static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
57476f6b 779
51470298 780struct rdpkt1_state_tag {
57476f6b 781 long len, pad, biglen, to_read;
782 unsigned long realcrc, gotcrc;
783 unsigned char *p;
784 int i;
785 int chunk;
ff3187f6 786 struct Packet *pktin;
51470298 787};
57476f6b 788
51470298 789struct rdpkt2_state_tag {
960e736a 790 long len, pad, payload, packetlen, maclen;
791 int i;
792 int cipherblk;
793 unsigned long incoming_sequence;
ff3187f6 794 struct Packet *pktin;
51470298 795};
796
06fadff5 797struct queued_handler;
798struct queued_handler {
799 int msg1, msg2;
800 chandler_fn_t handler;
801 void *ctx;
802 struct queued_handler *next;
803};
b09eaa88 804
51470298 805struct ssh_tag {
806 const struct plug_function_table *fn;
807 /* the above field _must_ be first in the structure */
808
4320baf7 809 char *v_c, *v_s;
b672f405 810 void *exhash;
51470298 811
812 Socket s;
813
b9d7bcad 814 void *ldisc;
a8327734 815 void *logctx;
b9d7bcad 816
51470298 817 unsigned char session_key[32];
818 int v1_compressing;
819 int v1_remote_protoflags;
820 int v1_local_protoflags;
821 int agentfwd_enabled;
822 int X11_fwd_enabled;
823 int remote_bugs;
824 const struct ssh_cipher *cipher;
371e569c 825 void *v1_cipher_ctx;
0183b242 826 void *crcda_ctx;
51470298 827 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 828 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 829 const struct ssh_mac *csmac, *scmac;
e0e1a00d 830 void *cs_mac_ctx, *sc_mac_ctx;
51470298 831 const struct ssh_compress *cscomp, *sccomp;
5366aed8 832 void *cs_comp_ctx, *sc_comp_ctx;
51470298 833 const struct ssh_kex *kex;
834 const struct ssh_signkey *hostkey;
754c0df9 835 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 836 int v2_session_id_len;
27cd7fc2 837 void *kex_ctx;
51470298 838
839 char *savedhost;
840 int savedport;
841 int send_ok;
842 int echoing, editing;
843
844 void *frontend;
845
db219738 846 int ospeed, ispeed; /* temporaries */
51470298 847 int term_width, term_height;
848
849 tree234 *channels; /* indexed by local id */
850 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 851 int ncmode; /* is primary channel direct-tcpip? */
51470298 852 int exitcode;
ac934965 853 int close_expected;
9e296bfa 854 int clean_exit;
51470298 855
fda2feb1 856 tree234 *rportfwds, *portfwds;
51470298 857
858 enum {
859 SSH_STATE_PREPACKET,
860 SSH_STATE_BEFORE_SIZE,
861 SSH_STATE_INTERMED,
862 SSH_STATE_SESSION,
863 SSH_STATE_CLOSED
864 } state;
865
866 int size_needed, eof_needed;
bc06669b 867 int sent_console_eof;
4a202fc6 868 int got_pty; /* affects EOF behaviour on main channel */
51470298 869
590f6a5f 870 struct Packet **queue;
871 int queuelen, queuesize;
872 int queueing;
51470298 873 unsigned char *deferred_send_data;
874 int deferred_len, deferred_size;
875
876 /*
877 * Gross hack: pscp will try to start SFTP but fall back to
878 * scp1 if that fails. This variable is the means by which
879 * scp.c can reach into the SSH code and find out which one it
880 * got.
881 */
882 int fallback_cmd;
883
6bbce591 884 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 885
acab36bc 886 Pkt_KCtx pkt_kctx;
887 Pkt_ACtx pkt_actx;
51470298 888
8def70c3 889 struct X11Display *x11disp;
302121de 890
51470298 891 int version;
ff68564b 892 int conn_throttle_count;
51470298 893 int overall_bufsize;
894 int throttled_all;
895 int v1_stdout_throttling;
a8756193 896 unsigned long v2_outgoing_sequence;
51470298 897
898 int ssh1_rdpkt_crstate;
899 int ssh2_rdpkt_crstate;
51470298 900 int ssh_gotdata_crstate;
b09eaa88 901 int do_ssh1_connection_crstate;
51470298 902
903 void *do_ssh_init_state;
904 void *do_ssh1_login_state;
905 void *do_ssh2_transport_state;
906 void *do_ssh2_authconn_state;
907
908 struct rdpkt1_state_tag rdpkt1_state;
909 struct rdpkt2_state_tag rdpkt2_state;
910
2e85c969 911 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 912 int protocol_initial_phase_done;
913
1c1a7262 914 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 915 struct Packet *pkt);
916 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 917
918 /*
4a693cfc 919 * We maintain our own copy of a Conf structure here. That way,
920 * when we're passed a new one for reconfiguration, we can check
921 * the differences and potentially reconfigure port forwardings
922 * etc in mid-session.
86916870 923 */
4a693cfc 924 Conf *conf;
925
926 /*
927 * Values cached out of conf so as to avoid the tree234 lookup
928 * cost every time they're used.
929 */
930 int logomitdata;
931
932 /*
933 * Dynamically allocated username string created during SSH
934 * login. Stored in here rather than in the coroutine state so
935 * that it'll be reliably freed if we shut down the SSH session
936 * at some unexpected moment.
937 */
938 char *username;
839f10db 939
940 /*
3d9449a1 941 * Used to transfer data back from async callbacks.
839f10db 942 */
943 void *agent_response;
944 int agent_response_len;
3d9449a1 945 int user_response;
946
947 /*
948 * The SSH connection can be set as `frozen', meaning we are
949 * not currently accepting incoming data from the network. This
950 * is slightly more serious than setting the _socket_ as
951 * frozen, because we may already have had data passed to us
952 * from the network which we need to delay processing until
953 * after the freeze is lifted, so we also need a bufchain to
954 * store that data.
955 */
956 int frozen;
957 bufchain queued_incoming_data;
b09eaa88 958
959 /*
960 * Dispatch table for packet types that we may have to deal
961 * with at any time.
962 */
963 handler_fn_t packet_dispatch[256];
39934deb 964
965 /*
06fadff5 966 * Queues of one-off handler functions for success/failure
967 * indications from a request.
968 */
969 struct queued_handler *qhead, *qtail;
bc074147 970 handler_fn_t q_saved_handler1, q_saved_handler2;
06fadff5 971
972 /*
39934deb 973 * This module deals with sending keepalives.
974 */
975 Pinger pinger;
9442dd57 976
977 /*
978 * Track incoming and outgoing data sizes and time, for
979 * size-based rekeys.
980 */
981 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 982 unsigned long max_data_size;
9442dd57 983 int kex_in_progress;
d719927e 984 unsigned long next_rekey, last_rekey;
e13bba36 985 char *deferred_rekey_reason; /* points to STATIC string; don't free */
42af6a67 986
987 /*
988 * Fully qualified host name, which we need if doing GSSAPI.
989 */
990 char *fullhostname;
1e00c92b 991
992#ifndef NO_GSSAPI
993 /*
994 * GSSAPI libraries for this session.
995 */
996 struct ssh_gss_liblist *gsslibs;
997#endif
51470298 998};
960e736a 999
382908ad 1000#define logevent(s) logevent(ssh->frontend, s)
a8327734 1001
1002/* logevent, only printf-formatted. */
cbe2d68f 1003static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 1004{
1005 va_list ap;
57356d63 1006 char *buf;
a8327734 1007
1008 va_start(ap, fmt);
57356d63 1009 buf = dupvprintf(fmt, ap);
a8327734 1010 va_end(ap);
57356d63 1011 logevent(buf);
57356d63 1012 sfree(buf);
a8327734 1013}
1014
3976feca 1015static void bomb_out(Ssh ssh, char *text)
1016{
1017 ssh_do_close(ssh, FALSE);
1018 logevent(text);
1019 connection_fatal(ssh->frontend, "%s", text);
1020 sfree(text);
1021}
1022
1023#define bombout(msg) bomb_out(ssh, dupprintf msg)
a8327734 1024
9a10ecf4 1025/* Functions to leave bits out of the SSH packet log file. */
1026
ff3187f6 1027static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1028{
4a693cfc 1029 if (conf_get_int(ssh->conf, CONF_logomitpass))
ff3187f6 1030 pkt->logmode = blanktype;
9a10ecf4 1031}
1032
ff3187f6 1033static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1034{
4a693cfc 1035 if (ssh->logomitdata)
ff3187f6 1036 pkt->logmode = blanktype;
9a10ecf4 1037}
1038
ff3187f6 1039static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 1040{
ff3187f6 1041 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 1042}
1043
4a693cfc 1044/* Helper function for common bits of parsing ttymodes. */
1045static void parse_ttymodes(Ssh ssh,
c6ccd5c2 1046 void (*do_mode)(void *data, char *mode, char *val),
1047 void *data)
1048{
4a693cfc 1049 char *key, *val;
1050
1051 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1052 val != NULL;
1053 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1054 /*
1055 * val[0] is either 'V', indicating that an explicit value
1056 * follows it, or 'A' indicating that we should pass the
1057 * value through from the local environment via get_ttymode.
1058 */
ab7a09e5 1059 if (val[0] == 'A') {
4a693cfc 1060 val = get_ttymode(ssh->frontend, key);
ab7a09e5 1061 if (val) {
1062 do_mode(data, key, val);
1063 sfree(val);
1064 }
1065 } else
1066 do_mode(data, key, val + 1); /* skip the 'V' */
c6ccd5c2 1067 }
1068}
1069
32874aea 1070static int ssh_channelcmp(void *av, void *bv)
1071{
1072 struct ssh_channel *a = (struct ssh_channel *) av;
1073 struct ssh_channel *b = (struct ssh_channel *) bv;
1074 if (a->localid < b->localid)
1075 return -1;
1076 if (a->localid > b->localid)
1077 return +1;
dacbd0e8 1078 return 0;
1079}
32874aea 1080static int ssh_channelfind(void *av, void *bv)
1081{
1082 unsigned *a = (unsigned *) av;
1083 struct ssh_channel *b = (struct ssh_channel *) bv;
1084 if (*a < b->localid)
1085 return -1;
1086 if (*a > b->localid)
1087 return +1;
dacbd0e8 1088 return 0;
1089}
1090
bc240b21 1091static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 1092{
1093 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1094 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1095 int i;
bc240b21 1096 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 1097 return i < 0 ? -1 : +1;
bc240b21 1098 if (a->dport > b->dport)
1099 return +1;
1100 if (a->dport < b->dport)
1101 return -1;
1102 return 0;
1103}
1104
1105static int ssh_rportcmp_ssh2(void *av, void *bv)
1106{
1107 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1108 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1109
bc240b21 1110 if (a->sport > b->sport)
d74d141c 1111 return +1;
bc240b21 1112 if (a->sport < b->sport)
1113 return -1;
d74d141c 1114 return 0;
1115}
1116
fda2feb1 1117/*
1118 * Special form of strcmp which can cope with NULL inputs. NULL is
1119 * defined to sort before even the empty string.
1120 */
1121static int nullstrcmp(const char *a, const char *b)
1122{
1123 if (a == NULL && b == NULL)
1124 return 0;
1125 if (a == NULL)
1126 return -1;
1127 if (b == NULL)
1128 return +1;
1129 return strcmp(a, b);
1130}
1131
1132static int ssh_portcmp(void *av, void *bv)
1133{
1134 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1135 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1136 int i;
1137 if (a->type > b->type)
1138 return +1;
1139 if (a->type < b->type)
1140 return -1;
84328ddb 1141 if (a->addressfamily > b->addressfamily)
1142 return +1;
1143 if (a->addressfamily < b->addressfamily)
1144 return -1;
fda2feb1 1145 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1146 return i < 0 ? -1 : +1;
1147 if (a->sport > b->sport)
1148 return +1;
1149 if (a->sport < b->sport)
1150 return -1;
1151 if (a->type != 'D') {
1152 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1153 return i < 0 ? -1 : +1;
1154 if (a->dport > b->dport)
1155 return +1;
1156 if (a->dport < b->dport)
1157 return -1;
1158 }
1159 return 0;
1160}
1161
51470298 1162static int alloc_channel_id(Ssh ssh)
32874aea 1163{
260f3dec 1164 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1165 unsigned low, high, mid;
d2371c81 1166 int tsize;
1167 struct ssh_channel *c;
1168
1169 /*
1170 * First-fit allocation of channel numbers: always pick the
1171 * lowest unused one. To do this, binary-search using the
1172 * counted B-tree to find the largest channel ID which is in a
1173 * contiguous sequence from the beginning. (Precisely
1174 * everything in that sequence must have ID equal to its tree
1175 * index plus CHANNEL_NUMBER_OFFSET.)
1176 */
51470298 1177 tsize = count234(ssh->channels);
d2371c81 1178
32874aea 1179 low = -1;
1180 high = tsize;
d2371c81 1181 while (high - low > 1) {
1182 mid = (high + low) / 2;
51470298 1183 c = index234(ssh->channels, mid);
d2371c81 1184 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1185 low = mid; /* this one is fine */
1186 else
1187 high = mid; /* this one is past it */
1188 }
1189 /*
1190 * Now low points to either -1, or the tree index of the
1191 * largest ID in the initial sequence.
1192 */
1193 {
1194 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1195 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1196 }
1197 return low + 1 + CHANNEL_NUMBER_OFFSET;
1198}
1199
edd0cb8a 1200static void c_write_stderr(int trusted, const char *buf, int len)
1201{
1202 int i;
1203 for (i = 0; i < len; i++)
667deca9 1204 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1205 fputc(buf[i], stderr);
1206}
1207
9fab77dc 1208static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1209{
edd0cb8a 1210 if (flags & FLAG_STDERR)
1211 c_write_stderr(1, buf, len);
1212 else
1213 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1214}
1215
9fab77dc 1216static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1217{
edd0cb8a 1218 if (flags & FLAG_STDERR)
1219 c_write_stderr(0, buf, len);
1220 else
1221 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1222}
1223
9fab77dc 1224static void c_write_str(Ssh ssh, const char *buf)
32874aea 1225{
51470298 1226 c_write(ssh, buf, strlen(buf));
1408a877 1227}
1228
ff3187f6 1229static void ssh_free_packet(struct Packet *pkt)
1230{
1231 sfree(pkt->data);
1232 sfree(pkt);
1233}
1234static struct Packet *ssh_new_packet(void)
1235{
1236 struct Packet *pkt = snew(struct Packet);
1237
dacd8872 1238 pkt->body = pkt->data = NULL;
ff3187f6 1239 pkt->maxlen = 0;
1240 pkt->logmode = PKTLOG_EMIT;
1241 pkt->nblanks = 0;
1242 pkt->blanks = NULL;
1243
1244 return pkt;
1245}
1246
fb09bf1c 1247/*
1248 * Collect incoming data in the incoming packet buffer.
e5574168 1249 * Decipher and verify the packet when it is completely read.
1250 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1251 * Update the *data and *datalen variables.
ff3187f6 1252 * Return a Packet structure when a packet is completed.
fb09bf1c 1253 */
ff3187f6 1254static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1255{
51470298 1256 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1257
51470298 1258 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1259
ff3187f6 1260 st->pktin = ssh_new_packet();
1261
1262 st->pktin->type = 0;
1263 st->pktin->length = 0;
374330e2 1264
57476f6b 1265 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1266 while ((*datalen) == 0)
ff3187f6 1267 crReturn(NULL);
57476f6b 1268 st->len = (st->len << 8) + **data;
fb09bf1c 1269 (*data)++, (*datalen)--;
1270 }
374330e2 1271
57476f6b 1272 st->pad = 8 - (st->len % 8);
1273 st->biglen = st->len + st->pad;
ff3187f6 1274 st->pktin->length = st->len - 5;
fb09bf1c 1275
ae0500e5 1276 if (st->biglen < 0) {
1277 bombout(("Extremely large packet length from server suggests"
1278 " data stream corruption"));
ff3187f6 1279 ssh_free_packet(st->pktin);
1280 crStop(NULL);
ae0500e5 1281 }
1282
ff3187f6 1283 st->pktin->maxlen = st->biglen;
1284 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1285
57476f6b 1286 st->to_read = st->biglen;
ff3187f6 1287 st->p = st->pktin->data;
57476f6b 1288 while (st->to_read > 0) {
32874aea 1289 st->chunk = st->to_read;
fb09bf1c 1290 while ((*datalen) == 0)
ff3187f6 1291 crReturn(NULL);
57476f6b 1292 if (st->chunk > (*datalen))
1293 st->chunk = (*datalen);
1294 memcpy(st->p, *data, st->chunk);
1295 *data += st->chunk;
1296 *datalen -= st->chunk;
1297 st->p += st->chunk;
1298 st->to_read -= st->chunk;
fb09bf1c 1299 }
374330e2 1300
ff3187f6 1301 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1302 st->biglen, NULL)) {
6b5cf8b4 1303 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1304 ssh_free_packet(st->pktin);
1305 crStop(NULL);
9a3a93a5 1306 }
1307
51470298 1308 if (ssh->cipher)
ff3187f6 1309 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1310
ff3187f6 1311 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1312 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1313 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1314 bombout(("Incorrect CRC received on packet"));
ff3187f6 1315 ssh_free_packet(st->pktin);
1316 crStop(NULL);
fb09bf1c 1317 }
572f871e 1318
ff3187f6 1319 st->pktin->body = st->pktin->data + st->pad + 1;
1320 st->pktin->savedpos = 0;
4ba9b64b 1321
51470298 1322 if (ssh->v1_compressing) {
4ba9b64b 1323 unsigned char *decompblk;
1324 int decomplen;
36b8d9bb 1325 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1326 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1327 &decompblk, &decomplen)) {
1328 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1329 ssh_free_packet(st->pktin);
1330 crStop(NULL);
36b8d9bb 1331 }
4ba9b64b 1332
ff3187f6 1333 if (st->pktin->maxlen < st->pad + decomplen) {
1334 st->pktin->maxlen = st->pad + decomplen;
1335 st->pktin->data = sresize(st->pktin->data,
1336 st->pktin->maxlen + APIEXTRA,
3d88e64d 1337 unsigned char);
ff3187f6 1338 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1339 }
1340
ff3187f6 1341 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1342 sfree(decompblk);
ff3187f6 1343 st->pktin->length = decomplen - 1;
4ba9b64b 1344 }
1345
ff3187f6 1346 st->pktin->type = st->pktin->body[-1];
00db133f 1347
9a10ecf4 1348 /*
1349 * Log incoming packet, possibly omitting sensitive fields.
1350 */
1351 if (ssh->logctx) {
1352 int nblanks = 0;
1353 struct logblank_t blank;
4a693cfc 1354 if (ssh->logomitdata) {
9a10ecf4 1355 int do_blank = FALSE, blank_prefix = 0;
1356 /* "Session data" packets - omit the data field */
ff3187f6 1357 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1358 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1359 do_blank = TRUE; blank_prefix = 4;
a2724fba 1360 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1361 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1362 }
1363 if (do_blank) {
1364 blank.offset = blank_prefix;
ff3187f6 1365 blank.len = st->pktin->length;
9a10ecf4 1366 blank.type = PKTLOG_OMIT;
1367 nblanks = 1;
1368 }
1369 }
a8327734 1370 log_packet(ssh->logctx,
ff3187f6 1371 PKT_INCOMING, st->pktin->type,
1372 ssh1_pkt_type(st->pktin->type),
1373 st->pktin->body, st->pktin->length,
0d13bfcd 1374 nblanks, &blank, NULL);
9a10ecf4 1375 }
00db133f 1376
ff3187f6 1377 crFinish(st->pktin);
fb09bf1c 1378}
1379
ff3187f6 1380static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1381{
51470298 1382 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1383
51470298 1384 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1385
ff3187f6 1386 st->pktin = ssh_new_packet();
1387
1388 st->pktin->type = 0;
1389 st->pktin->length = 0;
51470298 1390 if (ssh->sccipher)
1391 st->cipherblk = ssh->sccipher->blksize;
e5574168 1392 else
32874aea 1393 st->cipherblk = 8;
960e736a 1394 if (st->cipherblk < 8)
32874aea 1395 st->cipherblk = 8;
9916cc1e 1396 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
960e736a 1397
9916cc1e 1398 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1399 ssh->scmac) {
1400 /*
1401 * When dealing with a CBC-mode cipher, we want to avoid the
1402 * possibility of an attacker's tweaking the ciphertext stream
1403 * so as to cause us to feed the same block to the block
1404 * cipher more than once and thus leak information
1405 * (VU#958563). The way we do this is not to take any
1406 * decisions on the basis of anything we've decrypted until
1407 * we've verified it with a MAC. That includes the packet
1408 * length, so we just read data and check the MAC repeatedly,
1409 * and when the MAC passes, see if the length we've got is
1410 * plausible.
1411 */
1412
1413 /* May as well allocate the whole lot now. */
1414 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1415 unsigned char);
1416
1417 /* Read an amount corresponding to the MAC. */
1418 for (st->i = 0; st->i < st->maclen; st->i++) {
1419 while ((*datalen) == 0)
1420 crReturn(NULL);
1421 st->pktin->data[st->i] = *(*data)++;
1422 (*datalen)--;
1423 }
e5574168 1424
9916cc1e 1425 st->packetlen = 0;
1426 {
1427 unsigned char seq[4];
1428 ssh->scmac->start(ssh->sc_mac_ctx);
1429 PUT_32BIT(seq, st->incoming_sequence);
1430 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1431 }
4252c9cc 1432
9916cc1e 1433 for (;;) { /* Once around this loop per cipher block. */
1434 /* Read another cipher-block's worth, and tack it onto the end. */
1435 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1436 while ((*datalen) == 0)
1437 crReturn(NULL);
1438 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1439 (*datalen)--;
1440 }
1441 /* Decrypt one more block (a little further back in the stream). */
1442 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1443 st->pktin->data + st->packetlen,
1444 st->cipherblk);
1445 /* Feed that block to the MAC. */
1446 ssh->scmac->bytes(ssh->sc_mac_ctx,
1447 st->pktin->data + st->packetlen, st->cipherblk);
1448 st->packetlen += st->cipherblk;
1449 /* See if that gives us a valid packet. */
1450 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1451 st->pktin->data + st->packetlen) &&
b1650067 1452 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1453 st->packetlen-4))
9916cc1e 1454 break;
1455 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1456 bombout(("No valid incoming packet found"));
1457 ssh_free_packet(st->pktin);
1458 crStop(NULL);
1459 }
1460 }
1461 st->pktin->maxlen = st->packetlen + st->maclen;
1462 st->pktin->data = sresize(st->pktin->data,
1463 st->pktin->maxlen + APIEXTRA,
1464 unsigned char);
1465 } else {
1466 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1467
1468 /*
1469 * Acquire and decrypt the first block of the packet. This will
1470 * contain the length and padding details.
1471 */
1472 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1473 while ((*datalen) == 0)
1474 crReturn(NULL);
1475 st->pktin->data[st->i] = *(*data)++;
1476 (*datalen)--;
1477 }
e5574168 1478
9916cc1e 1479 if (ssh->sccipher)
1480 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1481 st->pktin->data, st->cipherblk);
1482
1483 /*
1484 * Now get the length figure.
1485 */
b1650067 1486 st->len = toint(GET_32BIT(st->pktin->data));
9916cc1e 1487
1488 /*
1489 * _Completely_ silly lengths should be stomped on before they
1490 * do us any more damage.
1491 */
1492 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1493 (st->len + 4) % st->cipherblk != 0) {
1494 bombout(("Incoming packet was garbled on decryption"));
1495 ssh_free_packet(st->pktin);
1496 crStop(NULL);
1497 }
e5574168 1498
9916cc1e 1499 /*
1500 * So now we can work out the total packet length.
1501 */
1502 st->packetlen = st->len + 4;
1503
1504 /*
1505 * Allocate memory for the rest of the packet.
1506 */
1507 st->pktin->maxlen = st->packetlen + st->maclen;
1508 st->pktin->data = sresize(st->pktin->data,
1509 st->pktin->maxlen + APIEXTRA,
1510 unsigned char);
1511
1512 /*
1513 * Read and decrypt the remainder of the packet.
1514 */
1515 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1516 st->i++) {
1517 while ((*datalen) == 0)
1518 crReturn(NULL);
1519 st->pktin->data[st->i] = *(*data)++;
1520 (*datalen)--;
1521 }
1522 /* Decrypt everything _except_ the MAC. */
1523 if (ssh->sccipher)
1524 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1525 st->pktin->data + st->cipherblk,
1526 st->packetlen - st->cipherblk);
1527
1528 /*
1529 * Check the MAC.
1530 */
1531 if (ssh->scmac
1532 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1533 st->len + 4, st->incoming_sequence)) {
1534 bombout(("Incorrect MAC received on packet"));
1535 ssh_free_packet(st->pktin);
1536 crStop(NULL);
1537 }
1538 }
1539 /* Get and sanity-check the amount of random padding. */
1540 st->pad = st->pktin->data[4];
1541 if (st->pad < 4 || st->len - st->pad < 1) {
1542 bombout(("Invalid padding length on received packet"));
ff3187f6 1543 ssh_free_packet(st->pktin);
1544 crStop(NULL);
717dc483 1545 }
717dc483 1546 /*
e5574168 1547 * This enables us to deduce the payload length.
1548 */
960e736a 1549 st->payload = st->len - st->pad - 1;
e5574168 1550
ff3187f6 1551 st->pktin->length = st->payload + 5;
9442dd57 1552 st->pktin->encrypted_len = st->packetlen;
1553
b09eaa88 1554 st->pktin->sequence = st->incoming_sequence++;
e5574168 1555
4ba9b64b 1556 /*
1557 * Decompress packet payload.
1558 */
1559 {
1560 unsigned char *newpayload;
1561 int newlen;
51470298 1562 if (ssh->sccomp &&
5366aed8 1563 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1564 st->pktin->data + 5, st->pktin->length - 5,
51470298 1565 &newpayload, &newlen)) {
ff3187f6 1566 if (st->pktin->maxlen < newlen + 5) {
1567 st->pktin->maxlen = newlen + 5;
1568 st->pktin->data = sresize(st->pktin->data,
1569 st->pktin->maxlen + APIEXTRA,
3d88e64d 1570 unsigned char);
4ba9b64b 1571 }
ff3187f6 1572 st->pktin->length = 5 + newlen;
1573 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1574 sfree(newpayload);
4ba9b64b 1575 }
1576 }
1577
ff3187f6 1578 st->pktin->savedpos = 6;
1579 st->pktin->body = st->pktin->data;
1580 st->pktin->type = st->pktin->data[5];
e5574168 1581
9a10ecf4 1582 /*
1583 * Log incoming packet, possibly omitting sensitive fields.
1584 */
1585 if (ssh->logctx) {
1586 int nblanks = 0;
1587 struct logblank_t blank;
4a693cfc 1588 if (ssh->logomitdata) {
9a10ecf4 1589 int do_blank = FALSE, blank_prefix = 0;
1590 /* "Session data" packets - omit the data field */
ff3187f6 1591 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1592 do_blank = TRUE; blank_prefix = 8;
a2724fba 1593 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1594 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1595 }
1596 if (do_blank) {
1597 blank.offset = blank_prefix;
ff3187f6 1598 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1599 blank.type = PKTLOG_OMIT;
1600 nblanks = 1;
1601 }
1602 }
ff3187f6 1603 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1604 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1605 st->pktin->type),
ff3187f6 1606 st->pktin->data+6, st->pktin->length-6,
0d13bfcd 1607 nblanks, &blank, &st->pktin->sequence);
9a10ecf4 1608 }
00db133f 1609
ff3187f6 1610 crFinish(st->pktin);
e5574168 1611}
1612
dacd8872 1613static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1614{
dacd8872 1615 int pad, biglen, i, pktoffs;
374330e2 1616 unsigned long crc;
fd7a4aad 1617#ifdef __SC__
1618 /*
1619 * XXX various versions of SC (including 8.8.4) screw up the
1620 * register allocation in this function and use the same register
1621 * (D6) for len and as a temporary, with predictable results. The
1622 * following sledgehammer prevents this.
1623 */
1624 volatile
1625#endif
1626 int len;
374330e2 1627
a8327734 1628 if (ssh->logctx)
dacd8872 1629 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1630 ssh1_pkt_type(pkt->data[12]),
1631 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1632 pkt->nblanks, pkt->blanks, NULL);
ff3187f6 1633 sfree(pkt->blanks); pkt->blanks = NULL;
1634 pkt->nblanks = 0;
00db133f 1635
51470298 1636 if (ssh->v1_compressing) {
4ba9b64b 1637 unsigned char *compblk;
1638 int complen;
5366aed8 1639 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1640 pkt->data + 12, pkt->length - 12,
4ba9b64b 1641 &compblk, &complen);
48406e6b 1642 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1643 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1644 sfree(compblk);
dacd8872 1645 pkt->length = complen + 12;
4ba9b64b 1646 }
1647
dacd8872 1648 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1649 pkt->length += 4;
1650 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1651 pad = 8 - (len % 8);
dacd8872 1652 pktoffs = 8 - pad;
1653 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1654
dacd8872 1655 for (i = pktoffs; i < 4+8; i++)
1656 pkt->data[i] = random_byte();
1657 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1658 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1659 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1660
51470298 1661 if (ssh->cipher)
dacd8872 1662 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1663 pkt->data + pktoffs + 4, biglen);
374330e2 1664
dacd8872 1665 if (offset_p) *offset_p = pktoffs;
1666 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1667}
1668
bf8a49a1 1669static int s_write(Ssh ssh, void *data, int len)
1670{
ff05dfef 1671 if (ssh->logctx)
0d13bfcd 1672 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1673 0, NULL, NULL);
bf8a49a1 1674 return sk_write(ssh->s, (char *)data, len);
1675}
1676
ff3187f6 1677static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1678{
dacd8872 1679 int len, backlog, offset;
1680 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1681 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1682 if (backlog > SSH_MAX_BACKLOG)
51470298 1683 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1684 ssh_free_packet(pkt);
39065bed 1685}
1686
ff3187f6 1687static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1688{
dacd8872 1689 int len, offset;
1690 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1691 if (ssh->deferred_len + len > ssh->deferred_size) {
1692 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1693 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1694 ssh->deferred_size,
1695 unsigned char);
39065bed 1696 }
dacd8872 1697 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1698 pkt->data + offset, len);
51470298 1699 ssh->deferred_len += len;
dacd8872 1700 ssh_free_packet(pkt);
374330e2 1701}
1702
fb09bf1c 1703/*
dacd8872 1704 * Construct a SSH-1 packet with the specified contents.
1705 * (This all-at-once interface used to be the only one, but now SSH-1
1706 * packets can also be constructed incrementally.)
fb09bf1c 1707 */
dacd8872 1708static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1709{
dacd8872 1710 int argtype;
7cca0d81 1711 Bignum bn;
ff3187f6 1712 struct Packet *pkt;
fb09bf1c 1713
dacd8872 1714 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1715
dacd8872 1716 while ((argtype = va_arg(ap, int)) != PKT_END) {
1717 unsigned char *argp, argchar;
8a9977e5 1718 char *sargp;
dacd8872 1719 unsigned long argint;
1720 int arglen;
fb09bf1c 1721 switch (argtype) {
9a10ecf4 1722 /* Actual fields in the packet */
fb09bf1c 1723 case PKT_INT:
dacd8872 1724 argint = va_arg(ap, int);
1725 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1726 break;
1727 case PKT_CHAR:
dacd8872 1728 argchar = (unsigned char) va_arg(ap, int);
1729 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1730 break;
1731 case PKT_DATA:
dacd8872 1732 argp = va_arg(ap, unsigned char *);
1733 arglen = va_arg(ap, int);
1734 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1735 break;
1736 case PKT_STR:
8a9977e5 1737 sargp = va_arg(ap, char *);
1738 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1739 break;
7cca0d81 1740 case PKT_BIGNUM:
dacd8872 1741 bn = va_arg(ap, Bignum);
1742 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1743 break;
1744 /* Tokens for modifications to packet logging */
1745 case PKTT_PASSWORD:
ff3187f6 1746 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1747 break;
1748 case PKTT_DATA:
ff3187f6 1749 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1750 break;
9a10ecf4 1751 case PKTT_OTHER:
ff3187f6 1752 end_log_omission(ssh, pkt);
9a10ecf4 1753 break;
1754 }
fb09bf1c 1755 }
ff3187f6 1756
1757 return pkt;
39065bed 1758}
fb09bf1c 1759
51470298 1760static void send_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(ssh, pkt);
fb09bf1c 1768}
1769
51470298 1770static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1771{
ff3187f6 1772 struct Packet *pkt;
dacd8872 1773 va_list ap;
1774 va_start(ap, pkttype);
1775 pkt = construct_packet(ssh, pkttype, ap);
1776 va_end(ap);
ff3187f6 1777 s_wrpkt_defer(ssh, pkt);
39065bed 1778}
1779
32874aea 1780static int ssh_versioncmp(char *a, char *b)
1781{
9697bfd2 1782 char *ae, *be;
1783 unsigned long av, bv;
1784
43aa02a7 1785 av = strtoul(a, &ae, 10);
1786 bv = strtoul(b, &be, 10);
32874aea 1787 if (av != bv)
1788 return (av < bv ? -1 : +1);
1789 if (*ae == '.')
1790 ae++;
1791 if (*be == '.')
1792 be++;
43aa02a7 1793 av = strtoul(ae, &ae, 10);
1794 bv = strtoul(be, &be, 10);
32874aea 1795 if (av != bv)
1796 return (av < bv ? -1 : +1);
9697bfd2 1797 return 0;
1798}
1799
e5574168 1800/*
a92dd380 1801 * Utility routines for putting an SSH-protocol `string' and
b672f405 1802 * `uint32' into a hash state.
e5574168 1803 */
b672f405 1804static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1805{
e5574168 1806 unsigned char lenblk[4];
e5574168 1807 PUT_32BIT(lenblk, len);
b672f405 1808 h->bytes(s, lenblk, 4);
1809 h->bytes(s, str, len);
e5574168 1810}
1811
b672f405 1812static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1813{
a92dd380 1814 unsigned char intblk[4];
1815 PUT_32BIT(intblk, i);
b672f405 1816 h->bytes(s, intblk, 4);
a92dd380 1817}
1818
7cca0d81 1819/*
dacd8872 1820 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1821 */
dacd8872 1822static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1823{
ff3187f6 1824 if (pkt->maxlen < length) {
dacd8872 1825 unsigned char *body = pkt->body;
3d71de0b 1826 int offset = body ? body - pkt->data : 0;
ff3187f6 1827 pkt->maxlen = length + 256;
1828 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1829 if (body) pkt->body = pkt->data + offset;
7cca0d81 1830 }
783415f8 1831}
dacd8872 1832static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1833{
ff3187f6 1834 if (pkt->logmode != PKTLOG_EMIT) {
1835 pkt->nblanks++;
1836 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1837 assert(pkt->body);
1838 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1839 (pkt->body - pkt->data);
ff3187f6 1840 pkt->blanks[pkt->nblanks-1].len = len;
1841 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1842 }
1843 pkt->length += len;
dacd8872 1844 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1845 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1846}
dacd8872 1847static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1848{
dacd8872 1849 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1850}
ff3187f6 1851static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1852{
dacd8872 1853 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1854}
dacd8872 1855static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1856{
7cca0d81 1857 unsigned char x[4];
1858 PUT_32BIT(x, value);
dacd8872 1859 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1860}
dacd8872 1861static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1862{
dacd8872 1863 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1864 pkt->savedpos = pkt->length;
7cca0d81 1865}
dacd8872 1866static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1867{
dacd8872 1868 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1869 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1870}
dacd8872 1871static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1872{
dacd8872 1873 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1874 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1875}
dacd8872 1876static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1877{
1878 ssh_pkt_addstring_start(pkt);
1879 ssh_pkt_addstring_str(pkt, data);
1880}
1881static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1882{
dacd8872 1883 int len = ssh1_bignum_length(b);
8a9977e5 1884 unsigned char *data = snewn(len, unsigned char);
dacd8872 1885 (void) ssh1_write_bignum(data, b);
1886 ssh_pkt_adddata(pkt, data, len);
1887 sfree(data);
7cca0d81 1888}
d8baa528 1889static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1890{
7cca0d81 1891 unsigned char *p;
32874aea 1892 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1893 p = snewn(n + 1, unsigned char);
7cca0d81 1894 p[0] = 0;
3709bfe9 1895 for (i = 1; i <= n; i++)
32874aea 1896 p[i] = bignum_byte(b, n - i);
7cca0d81 1897 i = 0;
32874aea 1898 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1899 i++;
1900 memmove(p, p + i, n + 1 - i);
1901 *len = n + 1 - i;
7cca0d81 1902 return p;
1903}
ff3187f6 1904static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1905{
7cca0d81 1906 unsigned char *p;
1907 int len;
1908 p = ssh2_mpint_fmt(b, &len);
dacd8872 1909 ssh_pkt_addstring_start(pkt);
1910 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1911 sfree(p);
7cca0d81 1912}
b185170a 1913
dacd8872 1914static struct Packet *ssh1_pkt_init(int pkt_type)
1915{
1916 struct Packet *pkt = ssh_new_packet();
1917 pkt->length = 4 + 8; /* space for length + max padding */
1918 ssh_pkt_addbyte(pkt, pkt_type);
1919 pkt->body = pkt->data + pkt->length;
1920 return pkt;
1921}
1922
1923/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1924#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1925#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1926#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1927#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1928#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1929#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1930#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1931#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1932
1933static struct Packet *ssh2_pkt_init(int pkt_type)
1934{
1935 struct Packet *pkt = ssh_new_packet();
3d71de0b 1936 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1937 pkt->forcepad = 0;
1938 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1939 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1940 return pkt;
1941}
1942
b185170a 1943/*
2e85c969 1944 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1945 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1946 * pkt->data. Total length is returned.
b185170a 1947 */
ff3187f6 1948static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1949{
7cca0d81 1950 int cipherblk, maclen, padding, i;
7cca0d81 1951
a8327734 1952 if (ssh->logctx)
ff3187f6 1953 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1954 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1955 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1956 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
ff3187f6 1957 sfree(pkt->blanks); pkt->blanks = NULL;
1958 pkt->nblanks = 0;
00db133f 1959
7cca0d81 1960 /*
4ba9b64b 1961 * Compress packet payload.
1962 */
4ba9b64b 1963 {
1964 unsigned char *newpayload;
1965 int newlen;
51470298 1966 if (ssh->cscomp &&
ff3187f6 1967 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1968 pkt->length - 5,
51470298 1969 &newpayload, &newlen)) {
ff3187f6 1970 pkt->length = 5;
1971 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1972 sfree(newpayload);
4ba9b64b 1973 }
1974 }
1975
1976 /*
7cca0d81 1977 * Add padding. At least four bytes, and must also bring total
1978 * length (minus MAC) up to a multiple of the block size.
95d2d262 1979 * If pkt->forcepad is set, make sure the packet is at least that size
1980 * after padding.
7cca0d81 1981 */
51470298 1982 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1983 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1984 padding = 4;
95d2d262 1985 if (pkt->length + padding < pkt->forcepad)
1986 padding = pkt->forcepad - pkt->length;
32874aea 1987 padding +=
ff3187f6 1988 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1989 assert(padding <= 255);
51470298 1990 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1991 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1992 pkt->data[4] = padding;
7cca0d81 1993 for (i = 0; i < padding; i++)
ff3187f6 1994 pkt->data[pkt->length + i] = random_byte();
1995 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1996 if (ssh->csmac)
ff3187f6 1997 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1998 pkt->length + padding,
51470298 1999 ssh->v2_outgoing_sequence);
2000 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2001
2002 if (ssh->cscipher)
371e569c 2003 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 2004 pkt->data, pkt->length + padding);
51470298 2005
9442dd57 2006 pkt->encrypted_len = pkt->length + padding;
2007
ff3187f6 2008 /* Ready-to-send packet starts at pkt->data. We return length. */
2009 return pkt->length + padding + maclen;
b185170a 2010}
2011
2012/*
590f6a5f 2013 * Routines called from the main SSH code to send packets. There
2014 * are quite a few of these, because we have two separate
2015 * mechanisms for delaying the sending of packets:
2016 *
2017 * - In order to send an IGNORE message and a password message in
2018 * a single fixed-length blob, we require the ability to
2019 * concatenate the encrypted forms of those two packets _into_ a
2020 * single blob and then pass it to our <network.h> transport
2021 * layer in one go. Hence, there's a deferment mechanism which
2022 * works after packet encryption.
2023 *
2024 * - In order to avoid sending any connection-layer messages
2025 * during repeat key exchange, we have to queue up any such
2026 * outgoing messages _before_ they are encrypted (and in
2027 * particular before they're allocated sequence numbers), and
2028 * then send them once we've finished.
2029 *
2030 * I call these mechanisms `defer' and `queue' respectively, so as
2031 * to distinguish them reasonably easily.
2032 *
2033 * The functions send_noqueue() and defer_noqueue() free the packet
2034 * structure they are passed. Every outgoing packet goes through
2035 * precisely one of these functions in its life; packets passed to
2036 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2037 * these or get queued, and then when the queue is later emptied
2038 * the packets are all passed to defer_noqueue().
97ab28d7 2039 *
2040 * When using a CBC-mode cipher, it's necessary to ensure that an
2041 * attacker can't provide data to be encrypted using an IV that they
2042 * know. We ensure this by prefixing each packet that might contain
2043 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2044 * mechanism, so in this case send_noqueue() ends up redirecting to
2045 * defer_noqueue(). If you don't like this inefficiency, don't use
2046 * CBC.
b185170a 2047 */
590f6a5f 2048
97ab28d7 2049static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2050static void ssh_pkt_defersend(Ssh);
2051
590f6a5f 2052/*
2e85c969 2053 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 2054 */
2055static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 2056{
5471d09a 2057 int len;
2058 int backlog;
97ab28d7 2059 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2060 /* We need to send two packets, so use the deferral mechanism. */
2061 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2062 ssh_pkt_defersend(ssh);
2063 return;
2064 }
ff3187f6 2065 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 2066 backlog = s_write(ssh, pkt->data, len);
5471d09a 2067 if (backlog > SSH_MAX_BACKLOG)
51470298 2068 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2069
2070 ssh->outgoing_data_size += pkt->encrypted_len;
2071 if (!ssh->kex_in_progress &&
d57f70af 2072 ssh->max_data_size != 0 &&
2073 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2074 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2075
ff3187f6 2076 ssh_free_packet(pkt);
b185170a 2077}
2078
2079/*
2e85c969 2080 * Defer an SSH-2 packet.
b185170a 2081 */
97ab28d7 2082static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 2083{
97ab28d7 2084 int len;
2085 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
cf6ddb95 2086 ssh->deferred_len == 0 && !noignore &&
2087 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
97ab28d7 2088 /*
2089 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2090 * get encrypted with a known IV.
2091 */
2092 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 2093 ssh2_pkt_addstring_start(ipkt);
97ab28d7 2094 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2095 }
2096 len = ssh2_pkt_construct(ssh, pkt);
51470298 2097 if (ssh->deferred_len + len > ssh->deferred_size) {
2098 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 2099 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2100 ssh->deferred_size,
2101 unsigned char);
b185170a 2102 }
ff3187f6 2103 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 2104 ssh->deferred_len += len;
9442dd57 2105 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 2106 ssh_free_packet(pkt);
b185170a 2107}
2108
2109/*
2e85c969 2110 * Queue an SSH-2 packet.
590f6a5f 2111 */
2112static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2113{
2114 assert(ssh->queueing);
2115
2116 if (ssh->queuelen >= ssh->queuesize) {
2117 ssh->queuesize = ssh->queuelen + 32;
2118 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2119 }
2120
2121 ssh->queue[ssh->queuelen++] = pkt;
2122}
2123
2124/*
2125 * Either queue or send a packet, depending on whether queueing is
2126 * set.
2127 */
2128static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2129{
2130 if (ssh->queueing)
2131 ssh2_pkt_queue(ssh, pkt);
2132 else
2133 ssh2_pkt_send_noqueue(ssh, pkt);
2134}
2135
2136/*
2137 * Either queue or defer a packet, depending on whether queueing is
2138 * set.
2139 */
2140static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2141{
2142 if (ssh->queueing)
2143 ssh2_pkt_queue(ssh, pkt);
2144 else
97ab28d7 2145 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 2146}
2147
2148/*
b185170a 2149 * Send the whole deferred data block constructed by
2e85c969 2150 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 2151 *
2152 * The expected use of the defer mechanism is that you call
2153 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2154 * not currently queueing, this simply sets up deferred_send_data
2155 * and then sends it. If we _are_ currently queueing, the calls to
2156 * ssh2_pkt_defer() put the deferred packets on to the queue
2157 * instead, and therefore ssh_pkt_defersend() has no deferred data
2158 * to send. Hence, there's no need to make it conditional on
2159 * ssh->queueing.
b185170a 2160 */
51470298 2161static void ssh_pkt_defersend(Ssh ssh)
32874aea 2162{
5471d09a 2163 int backlog;
bf8a49a1 2164 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 2165 ssh->deferred_len = ssh->deferred_size = 0;
2166 sfree(ssh->deferred_send_data);
2167 ssh->deferred_send_data = NULL;
5471d09a 2168 if (backlog > SSH_MAX_BACKLOG)
51470298 2169 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2170
2171 ssh->outgoing_data_size += ssh->deferred_data_size;
2172 if (!ssh->kex_in_progress &&
d57f70af 2173 ssh->max_data_size != 0 &&
2174 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2175 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2176 ssh->deferred_data_size = 0;
7cca0d81 2177}
2178
590f6a5f 2179/*
18524056 2180 * Send a packet whose length needs to be disguised (typically
2181 * passwords or keyboard-interactive responses).
2182 */
2183static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2184 int padsize)
2185{
2186#if 0
2187 if (0) {
2188 /*
2189 * The simplest way to do this is to adjust the
2190 * variable-length padding field in the outgoing packet.
2191 *
2192 * Currently compiled out, because some Cisco SSH servers
2193 * don't like excessively padded packets (bah, why's it
2194 * always Cisco?)
2195 */
2196 pkt->forcepad = padsize;
2197 ssh2_pkt_send(ssh, pkt);
2198 } else
2199#endif
2200 {
2201 /*
2202 * If we can't do that, however, an alternative approach is
2203 * to use the pkt_defer mechanism to bundle the packet
2204 * tightly together with an SSH_MSG_IGNORE such that their
2205 * combined length is a constant. So first we construct the
2206 * final form of this packet and defer its sending.
2207 */
2208 ssh2_pkt_defer(ssh, pkt);
2209
2210 /*
2211 * Now construct an SSH_MSG_IGNORE which includes a string
2212 * that's an exact multiple of the cipher block size. (If
2213 * the cipher is NULL so that the block size is
2214 * unavailable, we don't do this trick at all, because we
2215 * gain nothing by it.)
2216 */
cf6ddb95 2217 if (ssh->cscipher &&
2218 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
18524056 2219 int stringlen, i;
2220
2221 stringlen = (256 - ssh->deferred_len);
2222 stringlen += ssh->cscipher->blksize - 1;
2223 stringlen -= (stringlen % ssh->cscipher->blksize);
2224 if (ssh->cscomp) {
2225 /*
2226 * Temporarily disable actual compression, so we
2227 * can guarantee to get this string exactly the
2228 * length we want it. The compression-disabling
2229 * routine should return an integer indicating how
2230 * many bytes we should adjust our string length
2231 * by.
2232 */
2233 stringlen -=
2234 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2235 }
2236 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2237 ssh2_pkt_addstring_start(pkt);
2238 for (i = 0; i < stringlen; i++) {
2239 char c = (char) random_byte();
2240 ssh2_pkt_addstring_data(pkt, &c, 1);
2241 }
2242 ssh2_pkt_defer(ssh, pkt);
2243 }
2244 ssh_pkt_defersend(ssh);
2245 }
2246}
2247
2248/*
2e85c969 2249 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2250 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2251 * packets that needed to be lumped together.
2252 */
2253static void ssh2_pkt_queuesend(Ssh ssh)
2254{
2255 int i;
2256
2257 assert(!ssh->queueing);
2258
2259 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2260 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2261 ssh->queuelen = 0;
2262
2263 ssh_pkt_defersend(ssh);
2264}
2265
7cca0d81 2266#if 0
32874aea 2267void bndebug(char *string, Bignum b)
2268{
7cca0d81 2269 unsigned char *p;
2270 int i, len;
2271 p = ssh2_mpint_fmt(b, &len);
2272 debug(("%s", string));
2273 for (i = 0; i < len; i++)
32874aea 2274 debug((" %02x", p[i]));
765c4200 2275 debug(("\n"));
dcbde236 2276 sfree(p);
7cca0d81 2277}
2278#endif
2279
b672f405 2280static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2281{
7cca0d81 2282 unsigned char *p;
2283 int len;
2284 p = ssh2_mpint_fmt(b, &len);
b672f405 2285 hash_string(h, s, p, len);
dcbde236 2286 sfree(p);
7cca0d81 2287}
2288
2289/*
2e85c969 2290 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2291 */
ff3187f6 2292static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2293{
7cca0d81 2294 unsigned long value;
ff3187f6 2295 if (pkt->length - pkt->savedpos < 4)
32874aea 2296 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2297 value = GET_32BIT(pkt->body + pkt->savedpos);
2298 pkt->savedpos += 4;
7cca0d81 2299 return value;
2300}
ff3187f6 2301static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2302{
65a22376 2303 unsigned long value;
ff3187f6 2304 if (pkt->length - pkt->savedpos < 1)
32874aea 2305 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2306 value = pkt->body[pkt->savedpos] != 0;
2307 pkt->savedpos++;
65a22376 2308 return value;
2309}
ff3187f6 2310static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2311{
57356d63 2312 int len;
7cca0d81 2313 *p = NULL;
45068b27 2314 *length = 0;
ff3187f6 2315 if (pkt->length - pkt->savedpos < 4)
32874aea 2316 return;
b1650067 2317 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
57356d63 2318 if (len < 0)
2319 return;
2320 *length = len;
ff3187f6 2321 pkt->savedpos += 4;
2322 if (pkt->length - pkt->savedpos < *length)
32874aea 2323 return;
ff3187f6 2324 *p = (char *)(pkt->body + pkt->savedpos);
2325 pkt->savedpos += *length;
7cca0d81 2326}
ff3187f6 2327static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2328{
ff3187f6 2329 if (pkt->length - pkt->savedpos < length)
0016d70b 2330 return NULL;
ff3187f6 2331 pkt->savedpos += length;
2332 return pkt->body + (pkt->savedpos - length);
0016d70b 2333}
ff3187f6 2334static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2335 unsigned char **keystr)
2336{
2337 int j;
2338
ff3187f6 2339 j = makekey(pkt->body + pkt->savedpos,
2340 pkt->length - pkt->savedpos,
0016d70b 2341 key, keystr, 0);
2342
2343 if (j < 0)
2344 return FALSE;
2345
ff3187f6 2346 pkt->savedpos += j;
2347 assert(pkt->savedpos < pkt->length);
0016d70b 2348
2349 return TRUE;
2350}
ff3187f6 2351static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2352{
2353 int j;
2354 Bignum b;
2355
ff3187f6 2356 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2357 pkt->length - pkt->savedpos, &b);
0016d70b 2358
2359 if (j < 0)
2360 return NULL;
2361
ff3187f6 2362 pkt->savedpos += j;
0016d70b 2363 return b;
2364}
ff3187f6 2365static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2366{
7cca0d81 2367 char *p;
3709bfe9 2368 int length;
7cca0d81 2369 Bignum b;
2370
ff3187f6 2371 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2372 if (!p)
32874aea 2373 return NULL;
ff3187f6 2374 if (p[0] & 0x80)
32874aea 2375 return NULL;
d8baa528 2376 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2377 return b;
2378}
2379
7d503c31 2380/*
2e85c969 2381 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2382 * Expects to be shown the public key blob as well as the signature
2383 * blob. Normally works just like ssh2_pkt_addstring, but will
2384 * fiddle with the signature packet if necessary for
2385 * BUG_SSH2_RSA_PADDING.
2386 */
ff3187f6 2387static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2388 void *pkblob_v, int pkblob_len,
1dd353b5 2389 void *sigblob_v, int sigblob_len)
2390{
2391 unsigned char *pkblob = (unsigned char *)pkblob_v;
2392 unsigned char *sigblob = (unsigned char *)sigblob_v;
2393
2394 /* dmemdump(pkblob, pkblob_len); */
2395 /* dmemdump(sigblob, sigblob_len); */
2396
2397 /*
2398 * See if this is in fact an ssh-rsa signature and a buggy
2399 * server; otherwise we can just do this the easy way.
2400 */
b1650067 2401 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
1dd353b5 2402 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2403 int pos, len, siglen;
2404
2405 /*
2406 * Find the byte length of the modulus.
2407 */
2408
2409 pos = 4+7; /* skip over "ssh-rsa" */
b1650067 2410 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2411 if (len < 0 || len > pkblob_len - pos - 4)
2412 goto give_up;
2413 pos += 4 + len; /* skip over exponent */
2414 if (pkblob_len - pos < 4)
2415 goto give_up;
2416 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2417 if (len < 0 || len > pkblob_len - pos - 4)
2418 goto give_up;
1dd353b5 2419 pos += 4; /* find modulus itself */
2420 while (len > 0 && pkblob[pos] == 0)
2421 len--, pos++;
2422 /* debug(("modulus length is %d\n", len)); */
2423
2424 /*
2425 * Now find the signature integer.
2426 */
2427 pos = 4+7; /* skip over "ssh-rsa" */
b1650067 2428 if (sigblob_len < pos+4)
2429 goto give_up;
2430 siglen = toint(GET_32BIT(sigblob+pos));
2431 if (siglen != sigblob_len - pos - 4)
2432 goto give_up;
1dd353b5 2433 /* debug(("signature length is %d\n", siglen)); */
2434
2435 if (len != siglen) {
2436 unsigned char newlen[4];
ff3187f6 2437 ssh2_pkt_addstring_start(pkt);
2438 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2439 /* dmemdump(sigblob, pos); */
2440 pos += 4; /* point to start of actual sig */
2441 PUT_32BIT(newlen, len);
ff3187f6 2442 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2443 /* dmemdump(newlen, 4); */
2444 newlen[0] = 0;
2445 while (len-- > siglen) {
ff3187f6 2446 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2447 /* dmemdump(newlen, 1); */
2448 }
ff3187f6 2449 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2450 /* dmemdump(sigblob+pos, siglen); */
2451 return;
2452 }
2453
b1650067 2454 /* Otherwise fall through and do it the easy way. We also come
2455 * here as a fallback if we discover above that the key blob
2456 * is misformatted in some way. */
2457 give_up:;
1dd353b5 2458 }
2459
ff3187f6 2460 ssh2_pkt_addstring_start(pkt);
2461 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2462}
2463
2464/*
7d503c31 2465 * Examine the remote side's version string and compare it against
2466 * a list of known buggy implementations.
2467 */
51470298 2468static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2469{
2470 char *imp; /* pointer to implementation part */
7d503c31 2471 imp = vstring;
2472 imp += strcspn(imp, "-");
bd358db1 2473 if (*imp) imp++;
7d503c31 2474 imp += strcspn(imp, "-");
bd358db1 2475 if (*imp) imp++;
7d503c31 2476
51470298 2477 ssh->remote_bugs = 0;
7d503c31 2478
bf982899 2479 /*
2480 * General notes on server version strings:
2481 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2482 * here -- in particular, we've heard of one that's perfectly happy
2483 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2484 * so we can't distinguish them.
2485 */
4a693cfc 2486 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2487 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2c9c6388 2488 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2489 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2490 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2491 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2492 /*
2493 * These versions don't support SSH1_MSG_IGNORE, so we have
2494 * to use a different defence against password length
2495 * sniffing.
2496 */
51470298 2497 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2498 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2499 }
2500
4a693cfc 2501 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2502 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
46ac09aa 2503 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2504 /*
2505 * These versions need a plain password sent; they can't
2506 * handle having a null and a random length of data after
2507 * the password.
2508 */
51470298 2509 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2510 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2511 }
2512
4a693cfc 2513 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2514 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2c9c6388 2515 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2516 /*
2517 * These versions apparently have no clue whatever about
2518 * RSA authentication and will panic and die if they see
2519 * an AUTH_RSA message.
2520 */
51470298 2521 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2522 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2523 }
2524
4a693cfc 2525 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2526 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
b9f387af 2527 !wc_match("* VShell", imp) &&
831301f6 2528 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2529 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2530 wc_match("2.1 *", imp)))) {
32874aea 2531 /*
2532 * These versions have the HMAC bug.
2533 */
51470298 2534 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2535 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2536 }
1dd353b5 2537
4a693cfc 2538 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2539 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
b9f387af 2540 !wc_match("* VShell", imp) &&
2856a1b9 2541 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2542 /*
2543 * These versions have the key-derivation bug (failing to
2544 * include the literal shared secret in the hashes that
2545 * generate the keys).
2546 */
51470298 2547 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2548 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2549 }
2550
4a693cfc 2551 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2552 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
831301f6 2553 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2554 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2555 /*
2e85c969 2556 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2557 */
51470298 2558 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2559 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2560 }
8e975795 2561
4a693cfc 2562 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2563 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
dda87a28 2564 wc_match("OpenSSH_2.[0-2]*", imp))) {
2565 /*
2e85c969 2566 * These versions have the SSH-2 session-ID bug in
dda87a28 2567 * public-key authentication.
2568 */
2569 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2570 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2571 }
f382c87d 2572
4a693cfc 2573 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2574 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
39b8712f 2575 (wc_match("DigiSSH_2.0", imp) ||
2576 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2577 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2578 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2579 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2580 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2581 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2582 /*
2e85c969 2583 * These versions have the SSH-2 rekey bug.
f382c87d 2584 */
2585 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2586 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2587 }
c9739dba 2588
4a693cfc 2589 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2590 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
5ca836f2 2591 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2592 wc_match("1.36 sshlib: GlobalScape", imp)))) {
c9739dba 2593 /*
2594 * This version ignores our makpkt and needs to be throttled.
2595 */
2596 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2597 logevent("We believe remote version ignores SSH-2 maximum packet size");
2598 }
cf6ddb95 2599
4a693cfc 2600 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
cf6ddb95 2601 /*
2602 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2603 * none detected automatically.
2604 */
2605 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2606 logevent("We believe remote version has SSH-2 ignore bug");
2607 }
2e0aae4f 2608
2609 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2610 /*
2611 * Servers that don't support our winadj request for one
2612 * reason or another. Currently, none detected automatically.
2613 */
2614 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2615 logevent("We believe remote version has winadj bug");
2616 }
7d503c31 2617}
2618
d38d6a1f 2619/*
2620 * The `software version' part of an SSH version string is required
2621 * to contain no spaces or minus signs.
2622 */
2623static void ssh_fix_verstring(char *str)
2624{
2625 /* Eat "SSH-<protoversion>-". */
2626 assert(*str == 'S'); str++;
2627 assert(*str == 'S'); str++;
2628 assert(*str == 'H'); str++;
2629 assert(*str == '-'); str++;
2630 while (*str && *str != '-') str++;
2631 assert(*str == '-'); str++;
2632
2633 /* Convert minus signs and spaces in the remaining string into
2634 * underscores. */
2635 while (*str) {
2636 if (*str == '-' || *str == ' ')
2637 *str = '_';
2638 str++;
2639 }
2640}
2641
1fcd0d98 2642/*
2643 * Send an appropriate SSH version string.
2644 */
2645static void ssh_send_verstring(Ssh ssh, char *svers)
2646{
2647 char *verstring;
2648
2649 if (ssh->version == 2) {
2650 /*
2651 * Construct a v2 version string.
2652 */
2653 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2654 } else {
2655 /*
2656 * Construct a v1 version string.
2657 */
2658 verstring = dupprintf("SSH-%s-%s\012",
2659 (ssh_versioncmp(svers, "1.5") <= 0 ?
2660 svers : "1.5"),
2661 sshver);
2662 }
2663
2664 ssh_fix_verstring(verstring);
2665
2666 if (ssh->version == 2) {
2667 size_t len;
2668 /*
2669 * Record our version string.
2670 */
2671 len = strcspn(verstring, "\015\012");
2672 ssh->v_c = snewn(len + 1, char);
2673 memcpy(ssh->v_c, verstring, len);
2674 ssh->v_c[len] = 0;
2675 }
2676
2677 logeventf(ssh, "We claim version: %.*s",
2678 strcspn(verstring, "\015\012"), verstring);
2679 s_write(ssh, verstring, strlen(verstring));
2680 sfree(verstring);
2681}
2682
51470298 2683static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2684{
51470298 2685 struct do_ssh_init_state {
30919997 2686 int crLine;
51470298 2687 int vslen;
2688 char version[10];
2689 char *vstring;
2690 int vstrsize;
2691 int i;
2692 int proto1, proto2;
2693 };
2694 crState(do_ssh_init_state);
30919997 2695
2696 crBeginState;
8df7a775 2697
8c1835c0 2698 /* Search for a line beginning with the string "SSH-" in the input. */
2699 for (;;) {
2700 if (c != 'S') goto no;
2701 crReturn(1);
2702 if (c != 'S') goto no;
2703 crReturn(1);
2704 if (c != 'H') goto no;
2705 crReturn(1);
2706 if (c != '-') goto no;
2707 break;
2708 no:
2709 while (c != '\012')
2710 crReturn(1);
2711 crReturn(1);
374330e2 2712 }
8df7a775 2713
51470298 2714 s->vstrsize = 16;
3d88e64d 2715 s->vstring = snewn(s->vstrsize, char);
51470298 2716 strcpy(s->vstring, "SSH-");
2717 s->vslen = 4;
2718 s->i = 0;
374330e2 2719 while (1) {
8df7a775 2720 crReturn(1); /* get another char */
51470298 2721 if (s->vslen >= s->vstrsize - 1) {
2722 s->vstrsize += 16;
3d88e64d 2723 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2724 }
51470298 2725 s->vstring[s->vslen++] = c;
2726 if (s->i >= 0) {
374330e2 2727 if (c == '-') {
51470298 2728 s->version[s->i] = '\0';
2729 s->i = -1;
2730 } else if (s->i < sizeof(s->version) - 1)
2731 s->version[s->i++] = c;
c4ffc4d0 2732 } else if (c == '\012')
374330e2 2733 break;
2734 }
2735
51470298 2736 ssh->agentfwd_enabled = FALSE;
2737 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2738
51470298 2739 s->vstring[s->vslen] = 0;
a7d4653a 2740 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2741 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2742 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2743
adf799dd 2744 /*
38d228a2 2745 * Decide which SSH protocol version to support.
adf799dd 2746 */
38d228a2 2747
2748 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2749 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2750 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2751 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2752
4a693cfc 2753 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
6b5cf8b4 2754 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2755 crStop(0);
38d228a2 2756 }
4a693cfc 2757 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
6b5cf8b4 2758 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2759 crStop(0);
38d228a2 2760 }
2761
4a693cfc 2762 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
1fcd0d98 2763 ssh->version = 2;
2764 else
2765 ssh->version = 1;
d38d6a1f 2766
2767 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2768
1fcd0d98 2769 /* Send the version string, if we haven't already */
4a693cfc 2770 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
1fcd0d98 2771 ssh_send_verstring(ssh, s->version);
2772
2773 if (ssh->version == 2) {
2774 size_t len;
2775 /*
2776 * Record their version string.
2777 */
2778 len = strcspn(s->vstring, "\015\012");
2779 ssh->v_s = snewn(len + 1, char);
2780 memcpy(ssh->v_s, s->vstring, len);
2781 ssh->v_s[len] = 0;
2782
2783 /*
2784 * Initialise SSH-2 protocol.
2785 */
2786 ssh->protocol = ssh2_protocol;
2787 ssh2_protocol_setup(ssh);
2788 ssh->s_rdpkt = ssh2_rdpkt;
2789 } else {
2790 /*
2791 * Initialise SSH-1 protocol.
2792 */
2793 ssh->protocol = ssh1_protocol;
2794 ssh1_protocol_setup(ssh);
2795 ssh->s_rdpkt = ssh1_rdpkt;
2796 }
2797 if (ssh->version == 2)
2798 do_ssh2_transport(ssh, NULL, -1, NULL);
2799
125105d1 2800 update_specials_menu(ssh->frontend);
51470298 2801 ssh->state = SSH_STATE_BEFORE_SIZE;
4a693cfc 2802 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
8df7a775 2803
51470298 2804 sfree(s->vstring);
50526e47 2805
8df7a775 2806 crFinish(0);
2807}
2808
3d9449a1 2809static void ssh_process_incoming_data(Ssh ssh,
2810 unsigned char **data, int *datalen)
2811{
bf8a49a1 2812 struct Packet *pktin;
2813
2814 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2815 if (pktin) {
2816 ssh->protocol(ssh, NULL, 0, pktin);
2817 ssh_free_packet(pktin);
2818 }
2819}
2820
2821static void ssh_queue_incoming_data(Ssh ssh,
2822 unsigned char **data, int *datalen)
2823{
2824 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2825 *data += *datalen;
2826 *datalen = 0;
2827}
2828
2829static void ssh_process_queued_incoming_data(Ssh ssh)
2830{
2831 void *vdata;
2832 unsigned char *data;
2833 int len, origlen;
2834
2835 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2836 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2837 data = vdata;
2838 origlen = len;
2839
2840 while (!ssh->frozen && len > 0)
2841 ssh_process_incoming_data(ssh, &data, &len);
2842
2843 if (origlen > len)
2844 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2845 }
2846}
2847
2848static void ssh_set_frozen(Ssh ssh, int frozen)
2849{
a5a6f839 2850 if (ssh->s)
2851 sk_set_frozen(ssh->s, frozen);
3d9449a1 2852 ssh->frozen = frozen;
2853}
2854
51470298 2855static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2856{
bf8a49a1 2857 /* Log raw data, if we're in that mode. */
ff05dfef 2858 if (ssh->logctx)
2859 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
0d13bfcd 2860 0, NULL, NULL);
bf8a49a1 2861
51470298 2862 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2863
2864 /*
2865 * To begin with, feed the characters one by one to the
2866 * protocol initialisation / selection function do_ssh_init().
2867 * When that returns 0, we're done with the initial greeting
2868 * exchange and can move on to packet discipline.
2869 */
2870 while (1) {
51470298 2871 int ret; /* need not be kept across crReturn */
8df7a775 2872 if (datalen == 0)
2873 crReturnV; /* more data please */
51470298 2874 ret = do_ssh_init(ssh, *data);
32874aea 2875 data++;
2876 datalen--;
8df7a775 2877 if (ret == 0)
2878 break;
2879 }
2880
2881 /*
2882 * We emerge from that loop when the initial negotiation is
2883 * over and we have selected an s_rdpkt function. Now pass
2884 * everything to s_rdpkt, and then pass the resulting packets
2885 * to the proper protocol handler.
2886 */
3d9449a1 2887
8df7a775 2888 while (1) {
e375106c 2889 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2890 if (ssh->frozen) {
3d9449a1 2891 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2892 /* This uses up all data and cannot cause anything interesting
2893 * to happen; indeed, for anything to happen at all, we must
2894 * return, so break out. */
2895 break;
2896 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2897 /* This uses up some or all data, and may freeze the
2898 * session. */
2899 ssh_process_queued_incoming_data(ssh);
2900 } else {
2901 /* This uses up some or all data, and may freeze the
2902 * session. */
2903 ssh_process_incoming_data(ssh, &data, &datalen);
2904 }
2905 /* FIXME this is probably EBW. */
ff3187f6 2906 if (ssh->state == SSH_STATE_CLOSED)
2907 return;
8df7a775 2908 }
e375106c 2909 /* We're out of data. Go and get some more. */
8df7a775 2910 crReturnV;
2911 }
2912 crFinishV;
2913}
2914
ac934965 2915static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2916{
80ffa58b 2917 int ret = 0;
36f94d1f 2918 struct ssh_channel *c;
2919
51470298 2920 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2921 expire_timer_context(ssh);
51470298 2922 if (ssh->s) {
2923 sk_close(ssh->s);
2924 ssh->s = NULL;
ac934965 2925 if (notify_exit)
2926 notify_remote_exit(ssh->frontend);
2927 else
2928 ret = 1;
f3ab576e 2929 }
36f94d1f 2930 /*
80ffa58b 2931 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2932 * through this connection.
2933 */
74a98066 2934 if (ssh->channels) {
80ffa58b 2935 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2936 switch (c->type) {
2937 case CHAN_X11:
2938 x11_close(c->u.x11.s);
2939 break;
2940 case CHAN_SOCKDATA:
409eca86 2941 case CHAN_SOCKDATA_DORMANT:
74a98066 2942 pfd_close(c->u.pfd.s);
2943 break;
2944 }
80ffa58b 2945 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2946 if (ssh->version == 2)
2947 bufchain_clear(&c->v.v2.outbuffer);
2948 sfree(c);
36f94d1f 2949 }
36f94d1f 2950 }
f8c9f9df 2951 /*
2952 * Go through port-forwardings, and close any associated
2953 * listening sockets.
2954 */
2955 if (ssh->portfwds) {
2956 struct ssh_portfwd *pf;
2957 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2958 /* Dispose of any listening socket. */
2959 if (pf->local)
2960 pfd_terminate(pf->local);
2961 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2962 free_portfwd(pf);
2963 }
b72bdf11 2964 freetree234(ssh->portfwds);
2965 ssh->portfwds = NULL;
f8c9f9df 2966 }
ac934965 2967
2968 return ret;
36f94d1f 2969}
2970
7555d6a5 2971static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2972 const char *error_msg, int error_code)
2973{
2974 Ssh ssh = (Ssh) plug;
2975 char addrbuf[256], *msg;
2976
2977 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2978
2979 if (type == 0)
2980 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2981 else
2982 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2983
2984 logevent(msg);
fb983202 2985 sfree(msg);
7555d6a5 2986}
2987
cbe2d68f 2988static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2989 int calling_back)
2990{
2991 Ssh ssh = (Ssh) plug;
ac934965 2992 int need_notify = ssh_do_close(ssh, FALSE);
2993
9e296bfa 2994 if (!error_msg) {
2995 if (!ssh->close_expected)
2996 error_msg = "Server unexpectedly closed network connection";
2997 else
2998 error_msg = "Server closed network connection";
ac934965 2999 }
3000
d051d1b4 3001 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3002 ssh->exitcode = 0;
3003
2425184b 3004 if (need_notify)
3005 notify_remote_exit(ssh->frontend);
3006
9e296bfa 3007 if (error_msg)
247308b5 3008 logevent(error_msg);
9e296bfa 3009 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 3010 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 3011 return 0;
3012}
3013
32874aea 3014static int ssh_receive(Plug plug, int urgent, char *data, int len)
3015{
51470298 3016 Ssh ssh = (Ssh) plug;
d8baa528 3017 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 3018 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 3019 ssh_do_close(ssh, TRUE);
32874aea 3020 return 0;
3257deae 3021 }
fef97f43 3022 return 1;
374330e2 3023}
3024
5471d09a 3025static void ssh_sent(Plug plug, int bufsize)
3026{
51470298 3027 Ssh ssh = (Ssh) plug;
5471d09a 3028 /*
3029 * If the send backlog on the SSH socket itself clears, we
3030 * should unthrottle the whole world if it was throttled.
3031 */
3032 if (bufsize < SSH_MAX_BACKLOG)
51470298 3033 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 3034}
3035
fb09bf1c 3036/*
8df7a775 3037 * Connect to specified host and port.
3038 * Returns an error message, or NULL on success.
6e1ebb76 3039 * Also places the canonical host name into `realhost'. It must be
3040 * freed by the caller.
8df7a775 3041 */
cbe2d68f 3042static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 3043 char **realhost, int nodelay, int keepalive)
8df7a775 3044{
51470298 3045 static const struct plug_function_table fn_table = {
7555d6a5 3046 ssh_log,
7e78000d 3047 ssh_closing,
5471d09a 3048 ssh_receive,
3049 ssh_sent,
3050 NULL
51470298 3051 };
7e78000d 3052
8df7a775 3053 SockAddr addr;
cbe2d68f 3054 const char *err;
4a693cfc 3055 char *loghost;
3056 int addressfamily, sshprot;
3057
3058 loghost = conf_get_str(ssh->conf, CONF_loghost);
3059 if (*loghost) {
881da168 3060 char *colon;
8df7a775 3061
4a693cfc 3062 ssh->savedhost = dupstr(loghost);
881da168 3063 ssh->savedport = 22; /* default ssh port */
3064
3065 /*
3066 * A colon suffix on savedhost also lets us affect
3067 * savedport.
3068 *
3069 * (FIXME: do something about IPv6 address literals here.)
3070 */
3071 colon = strrchr(ssh->savedhost, ':');
3072 if (colon) {
3073 *colon++ = '\0';
3074 if (*colon)
3075 ssh->savedport = atoi(colon);
3076 }
3077 } else {
3078 ssh->savedhost = dupstr(host);
3079 if (port < 0)
3080 port = 22; /* default ssh port */
3081 ssh->savedport = port;
3082 }
8df7a775 3083
3084 /*
3085 * Try to find host.
3086 */
4a693cfc 3087 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
05581745 3088 logeventf(ssh, "Looking up host \"%s\"%s", host,
4a693cfc 3089 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3090 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3091 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
170c1e6e 3092 if ((err = sk_addr_error(addr)) != NULL) {
3093 sk_addr_free(addr);
8df7a775 3094 return err;
170c1e6e 3095 }
42af6a67 3096 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
8df7a775 3097
8df7a775 3098 /*
3099 * Open socket.
3100 */
51470298 3101 ssh->fn = &fn_table;
e8fa8f62 3102 ssh->s = new_connection(addr, *realhost, port,
4a693cfc 3103 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
70e5d0fd 3104 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 3105 ssh->s = NULL;
39934deb 3106 notify_remote_exit(ssh->frontend);
8df7a775 3107 return err;
67c4ba2e 3108 }
8df7a775 3109
ff05dfef 3110 /*
3111 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3112 * send the version string too.
3113 */
4a693cfc 3114 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3115 if (sshprot == 0)
ff05dfef 3116 ssh->version = 1;
4a693cfc 3117 if (sshprot == 3) {
ff05dfef 3118 ssh->version = 2;
3119 ssh_send_verstring(ssh, NULL);
3120 }
3121
881da168 3122 /*
3123 * loghost, if configured, overrides realhost.
3124 */
4a693cfc 3125 if (*loghost) {
881da168 3126 sfree(*realhost);
4a693cfc 3127 *realhost = dupstr(loghost);
881da168 3128 }
3129
8df7a775 3130 return NULL;
3131}
3132
3133/*
5471d09a 3134 * Throttle or unthrottle the SSH connection.
3135 */
ff68564b 3136static void ssh_throttle_conn(Ssh ssh, int adjust)
5471d09a 3137{
ff68564b 3138 int old_count = ssh->conn_throttle_count;
3139 ssh->conn_throttle_count += adjust;
3140 assert(ssh->conn_throttle_count >= 0);
3141 if (ssh->conn_throttle_count && !old_count) {
3d9449a1 3142 ssh_set_frozen(ssh, 1);
ff68564b 3143 } else if (!ssh->conn_throttle_count && old_count) {
3d9449a1 3144 ssh_set_frozen(ssh, 0);
5471d09a 3145 }
3146}
3147
3148/*
3149 * Throttle or unthrottle _all_ local data streams (for when sends
3150 * on the SSH connection itself back up).
3151 */
51470298 3152static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 3153{
3154 int i;
3155 struct ssh_channel *c;
3156
51470298 3157 if (enable == ssh->throttled_all)
5471d09a 3158 return;
51470298 3159 ssh->throttled_all = enable;
3160 ssh->overall_bufsize = bufsize;
3161 if (!ssh->channels)
5471d09a 3162 return;
51470298 3163 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 3164 switch (c->type) {
3165 case CHAN_MAINSESSION:
3166 /*
3167 * This is treated separately, outside the switch.
3168 */
3169 break;
3170 case CHAN_X11:
3171 x11_override_throttle(c->u.x11.s, enable);
3172 break;
3173 case CHAN_AGENT:
3174 /* Agent channels require no buffer management. */
3175 break;
3176 case CHAN_SOCKDATA:
36f94d1f 3177 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 3178 break;
3179 }
3180 }
3181}
3182
f11d78f2 3183static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 3184{
3185 Ssh ssh = (Ssh) sshv;
3186
3187 ssh->agent_response = reply;
3188 ssh->agent_response_len = replylen;
3189
3190 if (ssh->version == 1)
ff3187f6 3191 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 3192 else
ff3187f6 3193 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 3194}
3195
3d9449a1 3196static void ssh_dialog_callback(void *sshv, int ret)
3197{
3198 Ssh ssh = (Ssh) sshv;
3199
3200 ssh->user_response = ret;
3201
3202 if (ssh->version == 1)
3203 do_ssh1_login(ssh, NULL, -1, NULL);
3204 else
3205 do_ssh2_transport(ssh, NULL, -1, NULL);
3206
3207 /*
3208 * This may have unfrozen the SSH connection, so do a
3209 * queued-data run.
3210 */
3211 ssh_process_queued_incoming_data(ssh);
3212}
3213
f11d78f2 3214static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 3215{
3216 struct ssh_channel *c = (struct ssh_channel *)cv;
3217 Ssh ssh = c->ssh;
3218 void *sentreply = reply;
3219
be3f980d 3220 c->u.a.outstanding_requests--;
839f10db 3221 if (!sentreply) {
3222 /* Fake SSH_AGENT_FAILURE. */
3223 sentreply = "\0\0\0\1\5";
3224 replylen = 5;
3225 }
3226 if (ssh->version == 2) {
3227 ssh2_add_channel_data(c, sentreply, replylen);
3228 ssh2_try_send(c);
3229 } else {
3230 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3231 PKT_INT, c->remoteid,
3232 PKT_INT, replylen,
a2724fba 3233 PKTT_DATA,
839f10db 3234 PKT_DATA, sentreply, replylen,
9a10ecf4 3235 PKTT_OTHER,
839f10db 3236 PKT_END);
3237 }
3238 if (reply)
3239 sfree(reply);
be3f980d 3240 /*
3241 * If we've already seen an incoming EOF but haven't sent an
3242 * outgoing one, this may be the moment to send it.
3243 */
3244 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3245 sshfwd_write_eof(c);
839f10db 3246}
3247
0405e71f 3248/*
9e296bfa 3249 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3250 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3251 * => log `wire_reason'.
3252 */
3253static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3254 int code, int clean_exit)
3255{
3256 char *error;
3257 if (!client_reason)
3258 client_reason = wire_reason;
3259 if (client_reason)
3260 error = dupprintf("Disconnected: %s", client_reason);
3261 else
3262 error = dupstr("Disconnected");
3263 if (wire_reason) {
3264 if (ssh->version == 1) {
3265 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3266 PKT_END);
3267 } else if (ssh->version == 2) {
3268 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3269 ssh2_pkt_adduint32(pktout, code);
3270 ssh2_pkt_addstring(pktout, wire_reason);
3271 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3272 ssh2_pkt_send_noqueue(ssh, pktout);
3273 }
3274 }
3275 ssh->close_expected = TRUE;
3276 ssh->clean_exit = clean_exit;
3277 ssh_closing((Plug)ssh, error, 0, 0);
3278 sfree(error);
3279}
3280
3281/*
fb09bf1c 3282 * Handle the key exchange and user authentication phases.
3283 */
ff3187f6 3284static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3285 struct Packet *pktin)
fb09bf1c 3286{
0016d70b 3287 int i, j, ret;
3288 unsigned char cookie[8], *ptr;
374330e2 3289 struct MD5Context md5c;
51470298 3290 struct do_ssh1_login_state {
30919997 3291 int crLine;
51470298 3292 int len;
3293 unsigned char *rsabuf, *keystr1, *keystr2;
3294 unsigned long supported_ciphers_mask, supported_auths_mask;
3295 int tried_publickey, tried_agent;
3296 int tis_auth_refused, ccard_auth_refused;
3297 unsigned char session_id[16];
3298 int cipher_type;
51470298 3299 void *publickey_blob;
3300 int publickey_bloblen;
edd0cb8a 3301 char *publickey_comment;
3302 int publickey_encrypted;
3303 prompts_t *cur_prompt;
51470298 3304 char c;
3305 int pwpkt_type;
3306 unsigned char request[5], *response, *p;
3307 int responselen;
3308 int keyi, nkeys;
3309 int authed;
3310 struct RSAKey key;
3311 Bignum challenge;
3312 char *commentp;
3313 int commentlen;
3d9449a1 3314 int dlgret;
4a693cfc 3315 Filename *keyfile;
aacc46fa 3316 struct RSAKey servkey, hostkey;
51470298 3317 };
3318 crState(do_ssh1_login_state);
3319
30919997 3320 crBeginState;
374330e2 3321
ff3187f6 3322 if (!pktin)
3323 crWaitUntil(pktin);
374330e2 3324
ff3187f6 3325 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3326 bombout(("Public key packet not received"));
7ffdbc1a 3327 crStop(0);
8d5de777 3328 }
374330e2 3329
c5e9c988 3330 logevent("Received public keys");
374330e2 3331
ff3187f6 3332 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3333 if (!ptr) {
2e85c969 3334 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3335 crStop(0);
3336 }
3337 memcpy(cookie, ptr, 8);
374330e2 3338
aacc46fa 3339 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3340 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
2e85c969 3341 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3342 crStop(0);
3343 }
374330e2 3344
c5e9c988 3345 /*
1c2a93c4 3346 * Log the host key fingerprint.
c5e9c988 3347 */
c5e9c988 3348 {
3349 char logmsg[80];
1c2a93c4 3350 logevent("Host key fingerprint is:");
c5e9c988 3351 strcpy(logmsg, " ");
aacc46fa 3352 s->hostkey.comment = NULL;
32874aea 3353 rsa_fingerprint(logmsg + strlen(logmsg),
aacc46fa 3354 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
c5e9c988 3355 logevent(logmsg);
3356 }
3357
ff3187f6 3358 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3359 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3360 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3361 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3362 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3363
51470298 3364 ssh->v1_local_protoflags =
3365 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3366 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3367
c5e9c988 3368 MD5Init(&md5c);
aacc46fa 3369 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3370 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
0016d70b 3371 MD5Update(&md5c, cookie, 8);
51470298 3372 MD5Final(s->session_id, &md5c);
374330e2 3373
32874aea 3374 for (i = 0; i < 32; i++)
51470298 3375 ssh->session_key[i] = random_byte();
374330e2 3376
0016d70b 3377 /*
3378 * Verify that the `bits' and `bytes' parameters match.
3379 */
aacc46fa 3380 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3381 s->servkey.bits > s->servkey.bytes * 8) {
2e85c969 3382 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3383 crStop(0);
3384 }
3385
aacc46fa 3386 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3387 s->hostkey.bytes : s->servkey.bytes);
374330e2 3388
3d88e64d 3389 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3390
89ee5268 3391 /*
3392 * Verify the host key.
3393 */
3394 {
32874aea 3395 /*
3396 * First format the key into a string.
3397 */
aacc46fa 3398 int len = rsastr_len(&s->hostkey);
32874aea 3399 char fingerprint[100];
3d88e64d 3400 char *keystr = snewn(len, char);
aacc46fa 3401 rsastr_fmt(keystr, &s->hostkey);
3402 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3d9449a1 3403
3404 ssh_set_frozen(ssh, 1);
3405 s->dlgret = verify_ssh_host_key(ssh->frontend,
3406 ssh->savedhost, ssh->savedport,
3407 "rsa", keystr, fingerprint,
3408 ssh_dialog_callback, ssh);
32874aea 3409 sfree(keystr);
3d9449a1 3410 if (s->dlgret < 0) {
3411 do {
3412 crReturn(0);
3413 if (pktin) {
3414 bombout(("Unexpected data from server while waiting"
3415 " for user host key response"));
3416 crStop(0);
3417 }
3418 } while (pktin || inlen > 0);
3419 s->dlgret = ssh->user_response;
3420 }
3421 ssh_set_frozen(ssh, 0);
3422
3423 if (s->dlgret == 0) {
9e296bfa 3424 ssh_disconnect(ssh, "User aborted at host key verification",
3425 NULL, 0, TRUE);
2b3f6c19 3426 crStop(0);
3d9449a1 3427 }
32874aea 3428 }
3429
3430 for (i = 0; i < 32; i++) {
51470298 3431 s->rsabuf[i] = ssh->session_key[i];
374330e2 3432 if (i < 16)
51470298 3433 s->rsabuf[i] ^= s->session_id[i];
374330e2 3434 }
3435
aacc46fa 3436 if (s->hostkey.bytes > s->servkey.bytes) {
3437 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
0016d70b 3438 if (ret)
aacc46fa 3439 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
374330e2 3440 } else {
aacc46fa 3441 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
0016d70b 3442 if (ret)
aacc46fa 3443 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
0016d70b 3444 }
3445 if (!ret) {
2e85c969 3446 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3447 crStop(0);
374330e2 3448 }
3449
c5e9c988 3450 logevent("Encrypted session key");
3451
ca20bfcf 3452 {
3453 int cipher_chosen = 0, warn = 0;
3454 char *cipher_string = NULL;
51470298 3455 int i;
ca20bfcf 3456 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4a693cfc 3457 int next_cipher = conf_get_int_int(ssh->conf,
3458 CONF_ssh_cipherlist, i);
ca20bfcf 3459 if (next_cipher == CIPHER_WARN) {
3460 /* If/when we choose a cipher, warn about it */
3461 warn = 1;
3462 } else if (next_cipher == CIPHER_AES) {
3463 /* XXX Probably don't need to mention this. */
2e85c969 3464 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3465 } else {
3466 switch (next_cipher) {
51470298 3467 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3468 cipher_string = "3DES"; break;
51470298 3469 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3470 cipher_string = "Blowfish"; break;
51470298 3471 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3472 cipher_string = "single-DES"; break;
3473 }
51470298 3474 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3475 cipher_chosen = 1;
3476 }
3477 }
3478 if (!cipher_chosen) {
51470298 3479 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3480 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3481 "supporting 3DES encryption"));
3482 else
3483 /* shouldn't happen */
6b5cf8b4 3484 bombout(("No supported ciphers found"));
7ffdbc1a 3485 crStop(0);
a99a05c0 3486 }
ca20bfcf 3487
3488 /* Warn about chosen cipher if necessary. */
bb348ab1 3489 if (warn) {
3d9449a1 3490 ssh_set_frozen(ssh, 1);
3491 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3492 ssh_dialog_callback, ssh);
3493 if (s->dlgret < 0) {
3494 do {
3495 crReturn(0);
3496 if (pktin) {
3497 bombout(("Unexpected data from server while waiting"
3498 " for user response"));
3499 crStop(0);
3500 }
3501 } while (pktin || inlen > 0);
3502 s->dlgret = ssh->user_response;
3503 }
3504 ssh_set_frozen(ssh, 0);
3505 if (s->dlgret == 0) {
9e296bfa 3506 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3507 0, TRUE);
96ccde8b 3508 crStop(0);
3d9449a1 3509 }
bb348ab1 3510 }
bea1ef5f 3511 }
ca20bfcf 3512
51470298 3513 switch (s->cipher_type) {
32874aea 3514 case SSH_CIPHER_3DES:
3515 logevent("Using 3DES encryption");
3516 break;
3517 case SSH_CIPHER_DES:
3518 logevent("Using single-DES encryption");
3519 break;
3520 case SSH_CIPHER_BLOWFISH:
3521 logevent("Using Blowfish encryption");
3522 break;
c5e9c988 3523 }
bea1ef5f 3524
51470298 3525 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3526 PKT_CHAR, s->cipher_type,
32874aea 3527 PKT_DATA, cookie, 8,
51470298 3528 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3529 PKT_DATA, s->rsabuf, s->len,
3530 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3531
c5e9c988 3532 logevent("Trying to enable encryption...");
374330e2 3533
51470298 3534 sfree(s->rsabuf);
374330e2 3535
51470298 3536 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3537 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3538 &ssh_3des);
371e569c 3539 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3540 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3541 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3542
0183b242 3543 ssh->crcda_ctx = crcda_make_context();
3544 logevent("Installing CRC compensation attack detector");
3545
aacc46fa 3546 if (s->servkey.modulus) {
3547 sfree(s->servkey.modulus);
3548 s->servkey.modulus = NULL;
679539d7 3549 }
aacc46fa 3550 if (s->servkey.exponent) {
3551 sfree(s->servkey.exponent);
3552 s->servkey.exponent = NULL;
679539d7 3553 }
aacc46fa 3554 if (s->hostkey.modulus) {
3555 sfree(s->hostkey.modulus);
3556 s->hostkey.modulus = NULL;
679539d7 3557 }
aacc46fa 3558 if (s->hostkey.exponent) {
3559 sfree(s->hostkey.exponent);
3560 s->hostkey.exponent = NULL;
679539d7 3561 }
ff3187f6 3562 crWaitUntil(pktin);
374330e2 3563
ff3187f6 3564 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3565 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3566 crStop(0);
8d5de777 3567 }
374330e2 3568
c5e9c988 3569 logevent("Successfully started encryption");
3570
edd0cb8a 3571 fflush(stdout); /* FIXME eh? */
374330e2 3572 {
4a693cfc 3573 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 3574 int ret; /* need not be kept over crReturn */
3575 s->cur_prompt = new_prompts(ssh->frontend);
3576 s->cur_prompt->to_server = TRUE;
3577 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 3578 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 3579 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3580 while (ret < 0) {
51470298 3581 ssh->send_ok = 1;
edd0cb8a 3582 crWaitUntil(!pktin);
3583 ret = get_userpass_input(s->cur_prompt, in, inlen);
3584 ssh->send_ok = 0;
3585 }
3586 if (!ret) {
3587 /*
3588 * Failed to get a username. Terminate.
3589 */
3590 free_prompts(s->cur_prompt);
3591 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3592 crStop(0);
32874aea 3593 }
4a693cfc 3594 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 3595 free_prompts(s->cur_prompt);
374330e2 3596 }
fb09bf1c 3597
4a693cfc 3598 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
c5e9c988 3599 {
4a693cfc 3600 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
c5e9c988 3601 logevent(userlog);
32874aea 3602 if (flags & FLAG_INTERACTIVE &&
3603 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3604 c_write_str(ssh, userlog);
edd0cb8a 3605 c_write_str(ssh, "\r\n");
3c8e959b 3606 }
edd0cb8a 3607 sfree(userlog);
c5e9c988 3608 }
374330e2 3609 }
3610
ff3187f6 3611 crWaitUntil(pktin);
374330e2 3612
d5b2c841 3613 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3614 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3615 s->tried_publickey = s->tried_agent = 1;
0df73905 3616 } else {
51470298 3617 s->tried_publickey = s->tried_agent = 0;
0df73905 3618 }
51470298 3619 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3620 /*
3621 * Load the public half of any configured keyfile for later use.
3622 */
4a693cfc 3623 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 3624 if (!filename_is_null(s->keyfile)) {
edd0cb8a 3625 int keytype;
3626 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 3627 filename_to_str(s->keyfile));
3628 keytype = key_type(s->keyfile);
edd0cb8a 3629 if (keytype == SSH_KEYTYPE_SSH1) {
3630 const char *error;
4a693cfc 3631 if (rsakey_pubblob(s->keyfile,
edd0cb8a 3632 &s->publickey_blob, &s->publickey_bloblen,
3633 &s->publickey_comment, &error)) {
4a693cfc 3634 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
edd0cb8a 3635 NULL);
3636 } else {
3637 char *msgbuf;
3638 logeventf(ssh, "Unable to load private key (%s)", error);
3639 msgbuf = dupprintf("Unable to load private key file "
3640 "\"%.150s\" (%s)\r\n",
4a693cfc 3641 filename_to_str(s->keyfile),
edd0cb8a 3642 error);
3643 c_write_str(ssh, msgbuf);
3644 sfree(msgbuf);
3645 s->publickey_blob = NULL;
3646 }
3647 } else {
3648 char *msgbuf;
3649 logeventf(ssh, "Unable to use this key file (%s)",
3650 key_type_to_str(keytype));
3651 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3652 " (%s)\r\n",
4a693cfc 3653 filename_to_str(s->keyfile),
edd0cb8a 3654 key_type_to_str(keytype));
3655 c_write_str(ssh, msgbuf);
3656 sfree(msgbuf);
51470298 3657 s->publickey_blob = NULL;
edd0cb8a 3658 }
396778f1 3659 } else
51470298 3660 s->publickey_blob = NULL;
7cca0d81 3661
ff3187f6 3662 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3663 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3664
4a693cfc 3665 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
32874aea 3666 /*
3667 * Attempt RSA authentication using Pageant.
3668 */
32874aea 3669 void *r;
3670
51470298 3671 s->authed = FALSE;
3672 s->tried_agent = 1;
32874aea 3673 logevent("Pageant is running. Requesting keys.");
3674
3675 /* Request the keys held by the agent. */
51470298 3676 PUT_32BIT(s->request, 1);
3677 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3678 if (!agent_query(s->request, 5, &r, &s->responselen,
3679 ssh_agent_callback, ssh)) {
3680 do {
3681 crReturn(0);
ff3187f6 3682 if (pktin) {
839f10db 3683 bombout(("Unexpected data from server while waiting"
3684 " for agent response"));
3685 crStop(0);
3686 }
ff3187f6 3687 } while (pktin || inlen > 0);
839f10db 3688 r = ssh->agent_response;
3689 s->responselen = ssh->agent_response_len;
3690 }
51470298 3691 s->response = (unsigned char *) r;
3692 if (s->response && s->responselen >= 5 &&
3693 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3694 s->p = s->response + 5;
b1650067 3695 s->nkeys = toint(GET_32BIT(s->p));
3696 if (s->nkeys < 0) {
3697 logeventf(ssh, "Pageant reported negative key count %d",
3698 s->nkeys);
3699 s->nkeys = 0;
3700 }
51470298 3701 s->p += 4;
2e85c969 3702 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3703 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3704 unsigned char *pkblob = s->p;
51470298 3705 s->p += 4;
0016d70b 3706 {
3707 int n, ok = FALSE;
3708 do { /* do while (0) to make breaking easy */
3709 n = ssh1_read_bignum
b1650067 3710 (s->p, toint(s->responselen-(s->p-s->response)),
0016d70b 3711 &s->key.exponent);
3712 if (n < 0)
3713 break;
3714 s->p += n;
3715 n = ssh1_read_bignum
b1650067 3716 (s->p, toint(s->responselen-(s->p-s->response)),
0016d70b 3717 &s->key.modulus);
3718 if (n < 0)
b1650067 3719 break;
0016d70b 3720 s->p += n;
3721 if (s->responselen - (s->p-s->response) < 4)
3722 break;
b1650067 3723 s->commentlen = toint(GET_32BIT(s->p));
0016d70b 3724 s->p += 4;
b1650067 3725 if (s->commentlen < 0 ||
3726 toint(s->responselen - (s->p-s->response)) <
0016d70b 3727 s->commentlen)
3728 break;
3729 s->commentp = (char *)s->p;
3730 s->p += s->commentlen;
3731 ok = TRUE;
3732 } while (0);
3733 if (!ok) {
3734 logevent("Pageant key list packet was truncated");
3735 break;
3736 }
3737 }
94cd7c3a 3738 if (s->publickey_blob) {
3739 if (!memcmp(pkblob, s->publickey_blob,
3740 s->publickey_bloblen)) {
3741 logeventf(ssh, "Pageant key #%d matches "
3742 "configured key file", s->keyi);
3743 s->tried_publickey = 1;
3744 } else
3745 /* Skip non-configured key */
3746 continue;
3747 }
3748 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3749 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3750 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3751 crWaitUntil(pktin);
3752 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3753 logevent("Key refused");
3754 continue;
3755 }
3756 logevent("Received RSA challenge");
ff3187f6 3757 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3758 bombout(("Server's RSA challenge was badly formatted"));
3759 crStop(0);
3760 }
3761
32874aea 3762 {
3763 char *agentreq, *q, *ret;
2d466ffd 3764 void *vret;
32874aea 3765 int len, retlen;
3766 len = 1 + 4; /* message type, bit count */
51470298 3767 len += ssh1_bignum_length(s->key.exponent);
3768 len += ssh1_bignum_length(s->key.modulus);
3769 len += ssh1_bignum_length(s->challenge);
32874aea 3770 len += 16; /* session id */
3771 len += 4; /* response format */
3d88e64d 3772 agentreq = snewn(4 + len, char);
32874aea 3773 PUT_32BIT(agentreq, len);
3774 q = agentreq + 4;
3775 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3776 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3777 q += 4;
51470298 3778 q += ssh1_write_bignum(q, s->key.exponent);
3779 q += ssh1_write_bignum(q, s->key.modulus);
3780 q += ssh1_write_bignum(q, s->challenge);
3781 memcpy(q, s->session_id, 16);
32874aea 3782 q += 16;
3783 PUT_32BIT(q, 1); /* response format */
839f10db 3784 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3785 ssh_agent_callback, ssh)) {
3786 sfree(agentreq);
3787 do {
3788 crReturn(0);
ff3187f6 3789 if (pktin) {
839f10db 3790 bombout(("Unexpected data from server"
3791 " while waiting for agent"
3792 " response"));
3793 crStop(0);
3794 }
ff3187f6 3795 } while (pktin || inlen > 0);
839f10db 3796 vret = ssh->agent_response;
3797 retlen = ssh->agent_response_len;
3798 } else
3799 sfree(agentreq);
2d466ffd 3800 ret = vret;
32874aea 3801 if (ret) {
3802 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3803 logevent("Sending Pageant's response");
51470298 3804 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3805 PKT_DATA, ret + 5, 16,
3806 PKT_END);
3807 sfree(ret);
ff3187f6 3808 crWaitUntil(pktin);
3809 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3810 logevent
3811 ("Pageant's response accepted");
3812 if (flags & FLAG_VERBOSE) {
51470298 3813 c_write_str(ssh, "Authenticated using"
3814 " RSA key \"");
3815 c_write(ssh, s->commentp,
3816 s->commentlen);
3817 c_write_str(ssh, "\" from agent\r\n");
32874aea 3818 }
51470298 3819 s->authed = TRUE;
32874aea 3820 } else
3821 logevent
3822 ("Pageant's response not accepted");
3823 } else {
3824 logevent
3825 ("Pageant failed to answer challenge");
3826 sfree(ret);
3827 }
3828 } else {
3829 logevent("No reply received from Pageant");
3830 }
3831 }
51470298 3832 freebn(s->key.exponent);
3833 freebn(s->key.modulus);
3834 freebn(s->challenge);
3835 if (s->authed)
32874aea 3836 break;
3837 }
29b1d0b3 3838 sfree(s->response);
94cd7c3a 3839 if (s->publickey_blob && !s->tried_publickey)
3840 logevent("Configured key file not in Pageant");
5ff99b8e 3841 } else {
3842 logevent("Failed to get reply from Pageant");
3843 }
51470298 3844 if (s->authed)
32874aea 3845 break;
3846 }
edd0cb8a 3847 if (s->publickey_blob && !s->tried_publickey) {
3848 /*
3849 * Try public key authentication with the specified
3850 * key file.
3851 */
3852 int got_passphrase; /* need not be kept over crReturn */
3853 if (flags & FLAG_VERBOSE)
3854 c_write_str(ssh, "Trying public key authentication.\r\n");
4a693cfc 3855 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
edd0cb8a 3856 logeventf(ssh, "Trying public key \"%s\"",
4a693cfc 3857 filename_to_str(s->keyfile));
edd0cb8a 3858 s->tried_publickey = 1;
3859 got_passphrase = FALSE;
3860 while (!got_passphrase) {
3861 /*
3862 * Get a passphrase, if necessary.
3863 */
3864 char *passphrase = NULL; /* only written after crReturn */
3865 const char *error;
3866 if (!s->publickey_encrypted) {
3867 if (flags & FLAG_VERBOSE)
3868 c_write_str(ssh, "No passphrase required.\r\n");
3869 passphrase = NULL;
3870 } else {
3871 int ret; /* need not be kept over crReturn */
3872 s->cur_prompt = new_prompts(ssh->frontend);
3873 s->cur_prompt->to_server = FALSE;
3874 s->cur_prompt->name = dupstr("SSH key passphrase");
3875 add_prompt(s->cur_prompt,
3876 dupprintf("Passphrase for key \"%.100s\": ",
b61f81bc 3877 s->publickey_comment), FALSE);
edd0cb8a 3878 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3879 while (ret < 0) {
3880 ssh->send_ok = 1;
3881 crWaitUntil(!pktin);
3882 ret = get_userpass_input(s->cur_prompt, in, inlen);
3883 ssh->send_ok = 0;
3884 }
3885 if (!ret) {
3886 /* Failed to get a passphrase. Terminate. */
3887 free_prompts(s->cur_prompt);
3888 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3889 0, TRUE);
3890 crStop(0);
3891 }
3892 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3893 free_prompts(s->cur_prompt);
3894 }
3895 /*
3896 * Try decrypting key with passphrase.
3897 */
4a693cfc 3898 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3899 ret = loadrsakey(s->keyfile, &s->key, passphrase,
edd0cb8a 3900 &error);
3901 if (passphrase) {
dfb88efd 3902 smemclr(passphrase, strlen(passphrase));
edd0cb8a 3903 sfree(passphrase);
3904 }
3905 if (ret == 1) {
3906 /* Correct passphrase. */
3907 got_passphrase = TRUE;
3908 } else if (ret == 0) {
3909 c_write_str(ssh, "Couldn't load private key from ");
4a693cfc 3910 c_write_str(ssh, filename_to_str(s->keyfile));
edd0cb8a 3911 c_write_str(ssh, " (");
3912 c_write_str(ssh, error);
3913 c_write_str(ssh, ").\r\n");
3914 got_passphrase = FALSE;
3915 break; /* go and try something else */
3916 } else if (ret == -1) {
3917 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3918 got_passphrase = FALSE;
3919 /* and try again */
43536490 3920 } else {
3921 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3922 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3923 }
3924 }
3925
3926 if (got_passphrase) {
3927
3928 /*
3929 * Send a public key attempt.
3930 */
3931 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3932 PKT_BIGNUM, s->key.modulus, PKT_END);
3933
3934 crWaitUntil(pktin);
3935 if (pktin->type == SSH1_SMSG_FAILURE) {
3936 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3937 continue; /* go and try something else */
edd0cb8a 3938 }
3939 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3940 bombout(("Bizarre response to offer of public key"));
3941 crStop(0);
3942 }
3943
3944 {
3945 int i;
3946 unsigned char buffer[32];
3947 Bignum challenge, response;
3948
3949 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3950 bombout(("Server's RSA challenge was badly formatted"));
3951 crStop(0);
3952 }
3953 response = rsadecrypt(challenge, &s->key);
3954 freebn(s->key.private_exponent);/* burn the evidence */
3955
3956 for (i = 0; i < 32; i++) {
3957 buffer[i] = bignum_byte(response, 31 - i);
3958 }
3959
3960 MD5Init(&md5c);
3961 MD5Update(&md5c, buffer, 32);
3962 MD5Update(&md5c, s->session_id, 16);
3963 MD5Final(buffer, &md5c);
3964
3965 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3966 PKT_DATA, buffer, 16, PKT_END);
3967
3968 freebn(challenge);
3969 freebn(response);
3970 }
3971
3972 crWaitUntil(pktin);
3973 if (pktin->type == SSH1_SMSG_FAILURE) {
3974 if (flags & FLAG_VERBOSE)
3975 c_write_str(ssh, "Failed to authenticate with"
3976 " our public key.\r\n");
7b575324 3977 continue; /* go and try something else */
edd0cb8a 3978 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3979 bombout(("Bizarre response to RSA authentication response"));
3980 crStop(0);
3981 }
3982
3983 break; /* we're through! */
3984 }
3985
3986 }
3987
3988 /*
3989 * Otherwise, try various forms of password-like authentication.
3990 */
3991 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3992
4a693cfc 3993 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3994 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3995 !s->tis_auth_refused) {
3996 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3997 logevent("Requested TIS authentication");
51470298 3998 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3999 crWaitUntil(pktin);
4000 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 4001 logevent("TIS authentication declined");
4002 if (flags & FLAG_INTERACTIVE)
51470298 4003 c_write_str(ssh, "TIS authentication refused.\r\n");
4004 s->tis_auth_refused = 1;
614a20a0 4005 continue;
32874aea 4006 } else {
0016d70b 4007 char *challenge;
4008 int challengelen;
edd0cb8a 4009 char *instr_suf, *prompt;
0016d70b 4010
ff3187f6 4011 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4012 if (!challenge) {
4013 bombout(("TIS challenge packet was badly formed"));
4014 crStop(0);
4015 }
32874aea 4016 logevent("Received TIS challenge");
edd0cb8a 4017 s->cur_prompt->to_server = TRUE;
4018 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 4019 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 4020 if (memchr(challenge, '\n', challengelen)) {
4021 instr_suf = dupstr("");
4022 prompt = dupprintf("%.*s", challengelen, challenge);
4023 } else {
4024 instr_suf = dupprintf("%.*s", challengelen, challenge);
4025 prompt = dupstr("Response: ");
4026 }
4027 s->cur_prompt->instruction =
4028 dupprintf("Using TIS authentication.%s%s",
4029 (*instr_suf) ? "\n" : "",
4030 instr_suf);
4031 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4032 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4033 sfree(instr_suf);
32874aea 4034 }
4035 }
4a693cfc 4036 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 4037 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4038 !s->ccard_auth_refused) {
4039 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 4040 logevent("Requested CryptoCard authentication");
51470298 4041 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 4042 crWaitUntil(pktin);
4043 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 4044 logevent("CryptoCard authentication declined");
51470298 4045 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4046 s->ccard_auth_refused = 1;
614a20a0 4047 continue;
32874aea 4048 } else {
0016d70b 4049 char *challenge;
4050 int challengelen;
edd0cb8a 4051 char *instr_suf, *prompt;
0016d70b 4052
ff3187f6 4053 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4054 if (!challenge) {
4055 bombout(("CryptoCard challenge packet was badly formed"));
4056 crStop(0);
4057 }
32874aea 4058 logevent("Received CryptoCard challenge");
edd0cb8a 4059 s->cur_prompt->to_server = TRUE;
4060 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4061 s->cur_prompt->name_reqd = FALSE;
4062 /* Prompt heuristic comes from OpenSSH */
4063 if (memchr(challenge, '\n', challengelen)) {
4064 instr_suf = dupstr("");
4065 prompt = dupprintf("%.*s", challengelen, challenge);
4066 } else {
4067 instr_suf = dupprintf("%.*s", challengelen, challenge);
4068 prompt = dupstr("Response: ");
4069 }
4070 s->cur_prompt->instruction =
4071 dupprintf("Using CryptoCard authentication.%s%s",
4072 (*instr_suf) ? "\n" : "",
4073 instr_suf);
4074 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4075 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4076 sfree(instr_suf);
32874aea 4077 }
4078 }
51470298 4079 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 4080 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4081 bombout(("No supported authentication methods available"));
4082 crStop(0);
4083 }
edd0cb8a 4084 s->cur_prompt->to_server = TRUE;
4085 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 4086 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4087 ssh->username, ssh->savedhost),
b61f81bc 4088 FALSE);
32874aea 4089 }
a52f067e 4090
614a20a0 4091 /*
4092 * Show password prompt, having first obtained it via a TIS
4093 * or CryptoCard exchange if we're doing TIS or CryptoCard
4094 * authentication.
4095 */
edd0cb8a 4096 {
4097 int ret; /* need not be kept over crReturn */
4098 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4099 while (ret < 0) {
4100 ssh->send_ok = 1;
4101 crWaitUntil(!pktin);
4102 ret = get_userpass_input(s->cur_prompt, in, inlen);
4103 ssh->send_ok = 0;
4104 }
4105 if (!ret) {
32874aea 4106 /*
edd0cb8a 4107 * Failed to get a password (for example
32874aea 4108 * because one was supplied on the command line
4109 * which has already failed to work). Terminate.
4110 */
edd0cb8a 4111 free_prompts(s->cur_prompt);
4112 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4113 crStop(0);
32874aea 4114 }
32874aea 4115 }
4116
edd0cb8a 4117 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 4118 /*
edd0cb8a 4119 * Defence against traffic analysis: we send a
4120 * whole bunch of packets containing strings of
4121 * different lengths. One of these strings is the
4122 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4123 * The others are all random data in
4124 * SSH1_MSG_IGNORE packets. This way a passive
4125 * listener can't tell which is the password, and
4126 * hence can't deduce the password length.
4127 *
4128 * Anybody with a password length greater than 16
4129 * bytes is going to have enough entropy in their
4130 * password that a listener won't find it _that_
4131 * much help to know how long it is. So what we'll
4132 * do is:
4133 *
4134 * - if password length < 16, we send 15 packets
4135 * containing string lengths 1 through 15
4136 *
4137 * - otherwise, we let N be the nearest multiple
4138 * of 8 below the password length, and send 8
4139 * packets containing string lengths N through
4140 * N+7. This won't obscure the order of
4141 * magnitude of the password length, but it will
4142 * introduce a bit of extra uncertainty.
4143 *
bf982899 4144 * A few servers can't deal with SSH1_MSG_IGNORE, at
4145 * least in this context. For these servers, we need
4146 * an alternative defence. We make use of the fact
4147 * that the password is interpreted as a C string:
4148 * so we can append a NUL, then some random data.
edd0cb8a 4149 *
bf982899 4150 * A few servers can deal with neither SSH1_MSG_IGNORE
4151 * here _nor_ a padded password string.
4152 * For these servers we are left with no defences
edd0cb8a 4153 * against password length sniffing.
32874aea 4154 */
bf982899 4155 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4156 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 4157 /*
edd0cb8a 4158 * The server can deal with SSH1_MSG_IGNORE, so
4159 * we can use the primary defence.
32874aea 4160 */
edd0cb8a 4161 int bottom, top, pwlen, i;
4162 char *randomstr;
32874aea 4163
edd0cb8a 4164 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4165 if (pwlen < 16) {
4166 bottom = 0; /* zero length passwords are OK! :-) */
4167 top = 15;
4168 } else {
4169 bottom = pwlen & ~7;
4170 top = bottom + 7;
4171 }
32874aea 4172
edd0cb8a 4173 assert(pwlen >= bottom && pwlen <= top);
32874aea 4174
edd0cb8a 4175 randomstr = snewn(top + 1, char);
32874aea 4176
edd0cb8a 4177 for (i = bottom; i <= top; i++) {
4178 if (i == pwlen) {
4179 defer_packet(ssh, s->pwpkt_type,
4180 PKTT_PASSWORD, PKT_STR,
4181 s->cur_prompt->prompts[0]->result,
4182 PKTT_OTHER, PKT_END);
4183 } else {
4184 for (j = 0; j < i; j++) {
4185 do {
4186 randomstr[j] = random_byte();
4187 } while (randomstr[j] == '\0');
32874aea 4188 }
edd0cb8a 4189 randomstr[i] = '\0';
4190 defer_packet(ssh, SSH1_MSG_IGNORE,
4191 PKT_STR, randomstr, PKT_END);
32874aea 4192 }
edd0cb8a 4193 }
4194 logevent("Sending password with camouflage packets");
4195 ssh_pkt_defersend(ssh);
4196 sfree(randomstr);
4197 }
4198 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4199 /*
4200 * The server can't deal with SSH1_MSG_IGNORE
4201 * but can deal with padded passwords, so we
4202 * can use the secondary defence.
4203 */
4204 char string[64];
4205 char *ss;
4206 int len;
4207
4208 len = strlen(s->cur_prompt->prompts[0]->result);
4209 if (len < sizeof(string)) {
4210 ss = string;
4211 strcpy(string, s->cur_prompt->prompts[0]->result);
4212 len++; /* cover the zero byte */
4213 while (len < sizeof(string)) {
4214 string[len++] = (char) random_byte();
bd358db1 4215 }
bd358db1 4216 } else {
edd0cb8a 4217 ss = s->cur_prompt->prompts[0]->result;
32874aea 4218 }
edd0cb8a 4219 logevent("Sending length-padded password");
9a10ecf4 4220 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 4221 PKT_INT, len, PKT_DATA, ss, len,
4222 PKTT_OTHER, PKT_END);
4223 } else {
4224 /*
bf982899 4225 * The server is believed unable to cope with
4226 * any of our password camouflage methods.
edd0cb8a 4227 */
4228 int len;
4229 len = strlen(s->cur_prompt->prompts[0]->result);
4230 logevent("Sending unpadded password");
4231 send_packet(ssh, s->pwpkt_type,
4232 PKTT_PASSWORD, PKT_INT, len,
4233 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4234 PKTT_OTHER, PKT_END);
32874aea 4235 }
edd0cb8a 4236 } else {
4237 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4238 PKT_STR, s->cur_prompt->prompts[0]->result,
4239 PKTT_OTHER, PKT_END);
32874aea 4240 }
c5e9c988 4241 logevent("Sent password");
edd0cb8a 4242 free_prompts(s->cur_prompt);
ff3187f6 4243 crWaitUntil(pktin);
4244 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4245 if (flags & FLAG_VERBOSE)
51470298 4246 c_write_str(ssh, "Access denied\r\n");
c5e9c988 4247 logevent("Authentication refused");
ff3187f6 4248 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4249 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 4250 crStop(0);
374330e2 4251 }
4252 }
4253
edd0cb8a 4254 /* Clear up */
4255 if (s->publickey_blob) {
4256 sfree(s->publickey_blob);
4257 sfree(s->publickey_comment);
4258 }
4259
c5e9c988 4260 logevent("Authentication successful");
4261
fb09bf1c 4262 crFinish(1);
4263}
4264
bc06669b 4265static void ssh_channel_try_eof(struct ssh_channel *c)
4266{
4267 Ssh ssh = c->ssh;
4268 assert(c->pending_eof); /* precondition for calling us */
4269 if (c->halfopen)
4270 return; /* can't close: not even opened yet */
4271 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4272 return; /* can't send EOF: pending outgoing data */
4273
3620f307 4274 c->pending_eof = FALSE; /* we're about to send it */
bc06669b 4275 if (ssh->version == 1) {
4276 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4277 PKT_END);
4278 c->closes |= CLOSES_SENT_EOF;
4279 } else {
4280 struct Packet *pktout;
4281 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4282 ssh2_pkt_adduint32(pktout, c->remoteid);
4283 ssh2_pkt_send(ssh, pktout);
4284 c->closes |= CLOSES_SENT_EOF;
3620f307 4285 ssh2_channel_check_close(c);
bc06669b 4286 }
bc06669b 4287}
4288
4289void sshfwd_write_eof(struct ssh_channel *c)
32874aea 4290{
51470298 4291 Ssh ssh = c->ssh;
4292
1ef619ae 4293 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4294 return;
36f94d1f 4295
bc06669b 4296 if (c->closes & CLOSES_SENT_EOF)
4297 return;
78280721 4298
bc06669b 4299 c->pending_eof = TRUE;
4300 ssh_channel_try_eof(c);
32874aea 4301}
4302
c6b41791 4303void sshfwd_unclean_close(struct ssh_channel *c)
4304{
4305 Ssh ssh = c->ssh;
c6b41791 4306
4307 if (ssh->state == SSH_STATE_CLOSED)
4308 return;
4309
c6b41791 4310 switch (c->type) {
4311 case CHAN_X11:
4312 x11_close(c->u.x11.s);
04120005 4313 logevent("Forwarded X11 connection terminated due to local error");
c6b41791 4314 break;
4315 case CHAN_SOCKDATA:
4316 case CHAN_SOCKDATA_DORMANT:
4317 pfd_close(c->u.pfd.s);
04120005 4318 logevent("Forwarded port closed due to local error");
c6b41791 4319 break;
4320 }
4321 c->type = CHAN_ZOMBIE;
96210393 4322
c6b41791 4323 ssh2_channel_check_close(c);
4324}
4325
5471d09a 4326int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4327{
51470298 4328 Ssh ssh = c->ssh;
4329
1ef619ae 4330 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4331 return 0;
36f94d1f 4332
51470298 4333 if (ssh->version == 1) {
4334 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4335 PKT_INT, c->remoteid,
a2724fba 4336 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4337 PKTT_OTHER, PKT_END);
5471d09a 4338 /*
2e85c969 4339 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4340 * connections are never individually throttled - because
4341 * the only circumstance that can cause throttling will be
4342 * the whole SSH connection backing up, in which case
4343 * _everything_ will be throttled as a whole.
4344 */
4345 return 0;
783415f8 4346 } else {
32874aea 4347 ssh2_add_channel_data(c, buf, len);
5471d09a 4348 return ssh2_try_send(c);
4349 }
4350}
4351
4352void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4353{
51470298 4354 Ssh ssh = c->ssh;
ff68564b 4355 int buflimit;
51470298 4356
1ef619ae 4357 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4358 return;
36f94d1f 4359
51470298 4360 if (ssh->version == 1) {
ff68564b 4361 buflimit = SSH1_BUFFER_LIMIT;
5471d09a 4362 } else {
ff68564b 4363 buflimit = c->v.v2.locmaxwin;
4364 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4365 }
4366 if (c->throttling_conn && bufsize <= buflimit) {
4367 c->throttling_conn = 0;
4368 ssh_throttle_conn(ssh, -1);
783415f8 4369 }
9c964e85 4370}
4371
06fadff5 4372static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4373{
4374 struct queued_handler *qh = ssh->qhead;
4375
4376 assert(qh != NULL);
4377
4378 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4379
4380 if (qh->msg1 > 0) {
4381 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
bc074147 4382 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
06fadff5 4383 }
4384 if (qh->msg2 > 0) {
4385 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
bc074147 4386 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
06fadff5 4387 }
4388
4389 if (qh->next) {
4390 ssh->qhead = qh->next;
4391
4392 if (ssh->qhead->msg1 > 0) {
bc074147 4393 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
06fadff5 4394 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4395 }
4396 if (ssh->qhead->msg2 > 0) {
bc074147 4397 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
06fadff5 4398 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4399 }
4400 } else {
4401 ssh->qhead = ssh->qtail = NULL;
06fadff5 4402 }
4403
4404 qh->handler(ssh, pktin, qh->ctx);
4405
4406 sfree(qh);
4407}
4408
4409static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4410 chandler_fn_t handler, void *ctx)
4411{
4412 struct queued_handler *qh;
4413
4414 qh = snew(struct queued_handler);
4415 qh->msg1 = msg1;
4416 qh->msg2 = msg2;
4417 qh->handler = handler;
4418 qh->ctx = ctx;
4419 qh->next = NULL;
4420
4421 if (ssh->qtail == NULL) {
4422 ssh->qhead = qh;
4423
4424 if (qh->msg1 > 0) {
bc074147 4425 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
06fadff5 4426 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4427 }
4428 if (qh->msg2 > 0) {
bc074147 4429 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
06fadff5 4430 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4431 }
4432 } else {
4433 ssh->qtail->next = qh;
4434 }
4435 ssh->qtail = qh;
4436}
4437
4438static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4439{
4440 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4441
4442 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4443 SSH2_MSG_REQUEST_SUCCESS)) {
4444 logeventf(ssh, "Remote port forwarding from %s enabled",
4445 pf->sportdesc);
4446 } else {
4447 logeventf(ssh, "Remote port forwarding from %s refused",
4448 pf->sportdesc);
4449
4450 rpf = del234(ssh->rportfwds, pf);
4451 assert(rpf == pf);
8aea57fd 4452 pf->pfrec->remote = NULL;
fda2feb1 4453 free_rportfwd(pf);
06fadff5 4454 }
4455}
4456
4a693cfc 4457static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
06fadff5 4458{
84328ddb 4459 struct ssh_portfwd *epf;
4460 int i;
4a693cfc 4461 char *key, *val;
06fadff5 4462
fda2feb1 4463 if (!ssh->portfwds) {
4464 ssh->portfwds = newtree234(ssh_portcmp);
4465 } else {
4466 /*
4467 * Go through the existing port forwardings and tag them
84328ddb 4468 * with status==DESTROY. Any that we want to keep will be
4469 * re-enabled (status==KEEP) as we go through the
4470 * configuration and find out which bits are the same as
4471 * they were before.
fda2feb1 4472 */
4473 struct ssh_portfwd *epf;
4474 int i;
4475 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 4476 epf->status = DESTROY;
fda2feb1 4477 }
4478
4a693cfc 4479 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4480 val != NULL;
4481 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4482 char *kp, *kp2, *vp, *vp2;
84328ddb 4483 char address_family, type;
4484 int sport,dport,sserv,dserv;
4a693cfc 4485 char *sports, *dports, *saddr, *host;
4486
4487 kp = key;
84328ddb 4488
05581745 4489 address_family = 'A';
4490 type = 'L';
4a693cfc 4491 if (*kp == 'A' || *kp == '4' || *kp == '6')
4492 address_family = *kp++;
4493 if (*kp == 'L' || *kp == 'R')
4494 type = *kp++;
4495
4496 if ((kp2 = strchr(kp, ':')) != NULL) {
4497 /*
4498 * There's a colon in the middle of the source port
4499 * string, which means that the part before it is
4500 * actually a source address.
4501 */
4502 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4503 sports = kp2+1;
06fadff5 4504 } else {
4a693cfc 4505 saddr = NULL;
4506 sports = kp;
06fadff5 4507 }
4508 sport = atoi(sports);
4509 sserv = 0;
4510 if (sport == 0) {
4511 sserv = 1;
4512 sport = net_service_lookup(sports);
4513 if (!sport) {
4514 logeventf(ssh, "Service lookup failed for source"
4515 " port \"%s\"", sports);
4516 }
4517 }
4a693cfc 4518
4519 if (type == 'L' && !strcmp(val, "D")) {
4520 /* dynamic forwarding */
4521 host = NULL;
4522 dports = NULL;
4523 dport = -1;
4524 dserv = 0;
4525 type = 'D';
4526 } else {
4527 /* ordinary forwarding */
4528 vp = val;
4529 vp2 = vp + strcspn(vp, ":");
4530 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4531 if (vp2)
4532 vp2++;
4533 dports = vp2;
4534 dport = atoi(dports);
4535 dserv = 0;
4536 if (dport == 0) {
4537 dserv = 1;
4538 dport = net_service_lookup(dports);
4539 if (!dport) {
4540 logeventf(ssh, "Service lookup failed for destination"
4541 " port \"%s\"", dports);
4542 }
4543 }
4544 }
4545
06fadff5 4546 if (sport && dport) {
4547 /* Set up a description of the source port. */
fda2feb1 4548 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4549
4550 pfrec = snew(struct ssh_portfwd);
4551 pfrec->type = type;
4a693cfc 4552 pfrec->saddr = saddr;
3fe92132 4553 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4554 pfrec->sport = sport;
4a693cfc 4555 pfrec->daddr = host;
3fe92132 4556 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4557 pfrec->dport = dport;
4558 pfrec->local = NULL;
4559 pfrec->remote = NULL;
05581745 4560 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4561 address_family == '6' ? ADDRTYPE_IPV6 :
4562 ADDRTYPE_UNSPEC);
fda2feb1 4563
4564 epfrec = add234(ssh->portfwds, pfrec);
4565 if (epfrec != pfrec) {
c00c1931 4566 if (epfrec->status == DESTROY) {
4567 /*
4568 * We already have a port forwarding up and running
4569 * with precisely these parameters. Hence, no need
4570 * to do anything; simply re-tag the existing one
4571 * as KEEP.
4572 */
4573 epfrec->status = KEEP;
4574 }
fda2feb1 4575 /*
c00c1931 4576 * Anything else indicates that there was a duplicate
4577 * in our input, which we'll silently ignore.
fda2feb1 4578 */
fda2feb1 4579 free_portfwd(pfrec);
84328ddb 4580 } else {
4581 pfrec->status = CREATE;
4582 }
4a693cfc 4583 } else {
4584 sfree(saddr);
4585 sfree(host);
84328ddb 4586 }
4587 }
4588
4589 /*
4590 * Now go through and destroy any port forwardings which were
4591 * not re-enabled.
4592 */
4593 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4594 if (epf->status == DESTROY) {
4595 char *message;
4596
4597 message = dupprintf("%s port forwarding from %s%s%d",
4598 epf->type == 'L' ? "local" :
4599 epf->type == 'R' ? "remote" : "dynamic",
4600 epf->saddr ? epf->saddr : "",
4601 epf->saddr ? ":" : "",
4602 epf->sport);
4603
4604 if (epf->type != 'D') {
4605 char *msg2 = dupprintf("%s to %s:%d", message,
4606 epf->daddr, epf->dport);
4607 sfree(message);
4608 message = msg2;
4609 }
4610
4611 logeventf(ssh, "Cancelling %s", message);
4612 sfree(message);
4613
8aea57fd 4614 /* epf->remote or epf->local may be NULL if setting up a
4615 * forwarding failed. */
84328ddb 4616 if (epf->remote) {
4617 struct ssh_rportfwd *rpf = epf->remote;
4618 struct Packet *pktout;
4619
4620 /*
4621 * Cancel the port forwarding at the server
4622 * end.
4623 */
4624 if (ssh->version == 1) {
4625 /*
4626 * We cannot cancel listening ports on the
2e85c969 4627 * server side in SSH-1! There's no message
84328ddb 4628 * to support it. Instead, we simply remove
4629 * the rportfwd record from the local end
4630 * so that any connections the server tries
4631 * to make on it are rejected.
4632 */
4633 } else {
4634 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4635 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4636 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4637 if (epf->saddr) {
4638 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4639 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4640 /* XXX: rport_acceptall may not represent
5188540b 4641 * what was used to open the original connection,
4642 * since it's reconfigurable. */
b1b5c358 4643 ssh2_pkt_addstring(pktout, "");
84328ddb 4644 } else {
b1b5c358 4645 ssh2_pkt_addstring(pktout, "localhost");
84328ddb 4646 }
4647 ssh2_pkt_adduint32(pktout, epf->sport);
4648 ssh2_pkt_send(ssh, pktout);
4649 }
4650
4651 del234(ssh->rportfwds, rpf);
4652 free_rportfwd(rpf);
4653 } else if (epf->local) {
4654 pfd_terminate(epf->local);
4655 }
4656
4657 delpos234(ssh->portfwds, i);
4658 free_portfwd(epf);
4659 i--; /* so we don't skip one in the list */
4660 }
4661
4662 /*
4663 * And finally, set up any new port forwardings (status==CREATE).
4664 */
4665 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4666 if (epf->status == CREATE) {
4667 char *sportdesc, *dportdesc;
3fe92132 4668 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4669 epf->saddr ? epf->saddr : "",
4670 epf->saddr ? ":" : "",
3fe92132 4671 epf->sserv ? epf->sserv : "",
4672 epf->sserv ? "(" : "",
4673 epf->sport,
4674 epf->sserv ? ")" : "");
84328ddb 4675 if (epf->type == 'D') {
4676 dportdesc = NULL;
4677 } else {
3fe92132 4678 dportdesc = dupprintf("%s:%s%s%d%s",
4679 epf->daddr,
4680 epf->dserv ? epf->dserv : "",
4681 epf->dserv ? "(" : "",
4682 epf->dport,
4683 epf->dserv ? ")" : "");
84328ddb 4684 }
05581745 4685
84328ddb 4686 if (epf->type == 'L') {
4687 const char *err = pfd_addforward(epf->daddr, epf->dport,
4688 epf->saddr, epf->sport,
4a693cfc 4689 ssh, conf,
84328ddb 4690 &epf->local,
4691 epf->addressfamily);
4692
4693 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4694 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4695 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4696 sportdesc, dportdesc,
4697 err ? " failed: " : "", err ? err : "");
4698 } else if (epf->type == 'D') {
06fadff5 4699 const char *err = pfd_addforward(NULL, -1,
84328ddb 4700 epf->saddr, epf->sport,
4a693cfc 4701 ssh, conf,
84328ddb 4702 &epf->local,
4703 epf->addressfamily);
4704
4705 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4706 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4707 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4708 sportdesc,
4709 err ? " failed: " : "", err ? err : "");
06fadff5 4710 } else {
4711 struct ssh_rportfwd *pf;
4712
4713 /*
4714 * Ensure the remote port forwardings tree exists.
4715 */
4716 if (!ssh->rportfwds) {
4717 if (ssh->version == 1)
4718 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4719 else
4720 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4721 }
4722
4723 pf = snew(struct ssh_rportfwd);
84328ddb 4724 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4725 pf->dhost[lenof(pf->dhost)-1] = '\0';
4726 pf->dport = epf->dport;
4727 pf->sport = epf->sport;
06fadff5 4728 if (add234(ssh->rportfwds, pf) != pf) {
4729 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4730 epf->daddr, epf->dport);
06fadff5 4731 sfree(pf);
4732 } else {
4733 logeventf(ssh, "Requesting remote port %s"
84328ddb 4734 " forward to %s", sportdesc, dportdesc);
06fadff5 4735
4736 pf->sportdesc = sportdesc;
4737 sportdesc = NULL;
84328ddb 4738 epf->remote = pf;
4739 pf->pfrec = epf;
06fadff5 4740
4741 if (ssh->version == 1) {
4742 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4743 PKT_INT, epf->sport,
4744 PKT_STR, epf->daddr,
4745 PKT_INT, epf->dport,
06fadff5 4746 PKT_END);
4747 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4748 SSH1_SMSG_FAILURE,
4749 ssh_rportfwd_succfail, pf);
4750 } else {
4751 struct Packet *pktout;
4752 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4753 ssh2_pkt_addstring(pktout, "tcpip-forward");
4754 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4755 if (epf->saddr) {
4756 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4757 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
b1b5c358 4758 ssh2_pkt_addstring(pktout, "");
06fadff5 4759 } else {
b1b5c358 4760 ssh2_pkt_addstring(pktout, "localhost");
06fadff5 4761 }
84328ddb 4762 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4763 ssh2_pkt_send(ssh, pktout);
4764
4765 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4766 SSH2_MSG_REQUEST_FAILURE,
4767 ssh_rportfwd_succfail, pf);
4768 }
4769 }
4770 }
4771 sfree(sportdesc);
84328ddb 4772 sfree(dportdesc);
06fadff5 4773 }
06fadff5 4774}
4775
51df0ab5 4776static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4777{
4778 char *string;
4779 int stringlen, bufsize;
4780
4781 ssh_pkt_getstring(pktin, &string, &stringlen);
4782 if (string == NULL) {
4783 bombout(("Incoming terminal data packet was badly formed"));
4784 return;
4785 }
4786
4787 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4788 string, stringlen);
4789 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4790 ssh->v1_stdout_throttling = 1;
ff68564b 4791 ssh_throttle_conn(ssh, +1);
51df0ab5 4792 }
4793}
4794
4795static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4796{
4797 /* Remote side is trying to open a channel to talk to our
4798 * X-Server. Give them back a local channel number. */
4799 struct ssh_channel *c;
4800 int remoteid = ssh_pkt_getuint32(pktin);
4801
4802 logevent("Received X11 connect request");
4803 /* Refuse if X11 forwarding is disabled. */
4804 if (!ssh->X11_fwd_enabled) {
4805 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4806 PKT_INT, remoteid, PKT_END);
4807 logevent("Rejected X11 connect request");
4808 } else {
4809 c = snew(struct ssh_channel);
4810 c->ssh = ssh;
4811
8def70c3 4812 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 4813 NULL, -1, ssh->conf) != NULL) {
51df0ab5 4814 logevent("Opening X11 forward connection failed");
4815 sfree(c);
4816 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4817 PKT_INT, remoteid, PKT_END);
4818 } else {
4819 logevent
4820 ("Opening X11 forward connection succeeded");
4821 c->remoteid = remoteid;
64d6ff88 4822 c->halfopen = FALSE;
51df0ab5 4823 c->localid = alloc_channel_id(ssh);
4824 c->closes = 0;
bc06669b 4825 c->pending_eof = FALSE;
ff68564b 4826 c->throttling_conn = 0;
51df0ab5 4827 c->type = CHAN_X11; /* identify channel type */
4828 add234(ssh->channels, c);
4829 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4830 PKT_INT, c->remoteid, PKT_INT,
4831 c->localid, PKT_END);
4832 logevent("Opened X11 forward channel");
4833 }
4834 }
4835}
4836
4837static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4838{
4839 /* Remote side is trying to open a channel to talk to our
4840 * agent. Give them back a local channel number. */
4841 struct ssh_channel *c;
4842 int remoteid = ssh_pkt_getuint32(pktin);
4843
4844 /* Refuse if agent forwarding is disabled. */
4845 if (!ssh->agentfwd_enabled) {
4846 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4847 PKT_INT, remoteid, PKT_END);
4848 } else {
4849 c = snew(struct ssh_channel);
4850 c->ssh = ssh;
4851 c->remoteid = remoteid;
64d6ff88 4852 c->halfopen = FALSE;
51df0ab5 4853 c->localid = alloc_channel_id(ssh);
4854 c->closes = 0;
bc06669b 4855 c->pending_eof = FALSE;
ff68564b 4856 c->throttling_conn = 0;
51df0ab5 4857 c->type = CHAN_AGENT; /* identify channel type */
4858 c->u.a.lensofar = 0;
bc06669b 4859 c->u.a.message = NULL;
be3f980d 4860 c->u.a.outstanding_requests = 0;
51df0ab5 4861 add234(ssh->channels, c);
4862 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4863 PKT_INT, c->remoteid, PKT_INT, c->localid,
4864 PKT_END);
4865 }
4866}
4867
4868static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4869{
4870 /* Remote side is trying to open a channel to talk to a
4871 * forwarded port. Give them back a local channel number. */
05581745 4872 struct ssh_rportfwd pf, *pfp;
51df0ab5 4873 int remoteid;
4874 int hostsize, port;
fb983202 4875 char *host;
51df0ab5 4876 const char *e;
51df0ab5 4877
4878 remoteid = ssh_pkt_getuint32(pktin);
4879 ssh_pkt_getstring(pktin, &host, &hostsize);
4880 port = ssh_pkt_getuint32(pktin);
4881
4882 if (hostsize >= lenof(pf.dhost))
4883 hostsize = lenof(pf.dhost)-1;
4884 memcpy(pf.dhost, host, hostsize);
4885 pf.dhost[hostsize] = '\0';
4886 pf.dport = port;
05581745 4887 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4888
05581745 4889 if (pfp == NULL) {
fb983202 4890 logeventf(ssh, "Rejected remote port open request for %s:%d",
4891 pf.dhost, port);
51df0ab5 4892 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4893 PKT_INT, remoteid, PKT_END);
4894 } else {
038ec85e 4895 struct ssh_channel *c = snew(struct ssh_channel);
4896 c->ssh = ssh;
4897
fb983202 4898 logeventf(ssh, "Received remote port open request for %s:%d",
4899 pf.dhost, port);
51df0ab5 4900 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4a693cfc 4901 c, ssh->conf, pfp->pfrec->addressfamily);
51df0ab5 4902 if (e != NULL) {
fb983202 4903 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4904 sfree(c);
4905 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4906 PKT_INT, remoteid, PKT_END);
4907 } else {
4908 c->remoteid = remoteid;
64d6ff88 4909 c->halfopen = FALSE;
51df0ab5 4910 c->localid = alloc_channel_id(ssh);
4911 c->closes = 0;
bc06669b 4912 c->pending_eof = FALSE;
ff68564b 4913 c->throttling_conn = 0;
51df0ab5 4914 c->type = CHAN_SOCKDATA; /* identify channel type */
4915 add234(ssh->channels, c);
4916 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4917 PKT_INT, c->remoteid, PKT_INT,
4918 c->localid, PKT_END);
4919 logevent("Forwarded port opened successfully");
4920 }
4921 }
4922}
4923
4924static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4925{
4926 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4927 unsigned int localid = ssh_pkt_getuint32(pktin);
4928 struct ssh_channel *c;
4929
4930 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4931 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4932 c->remoteid = localid;
64d6ff88 4933 c->halfopen = FALSE;
51df0ab5 4934 c->type = CHAN_SOCKDATA;
ff68564b 4935 c->throttling_conn = 0;
51df0ab5 4936 pfd_confirm(c->u.pfd.s);
4937 }
4938
bc06669b 4939 if (c && c->pending_eof) {
51df0ab5 4940 /*
4941 * We have a pending close on this channel,
4942 * which we decided on before the server acked
4943 * the channel open. So now we know the
4944 * remoteid, we can close it again.
4945 */
bc06669b 4946 ssh_channel_try_eof(c);
51df0ab5 4947 }
4948}
4949
4950static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4951{
4952 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4953 struct ssh_channel *c;
4954
4955 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4956 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4957 logevent("Forwarded connection refused by server");
4958 pfd_close(c->u.pfd.s);
4959 del234(ssh->channels, c);
4960 sfree(c);
4961 }
4962}
4963
4964static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4965{
4966 /* Remote side closes a channel. */
4967 unsigned i = ssh_pkt_getuint32(pktin);
4968 struct ssh_channel *c;
4969 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4970 if (c && !c->halfopen) {
51df0ab5 4971
bc06669b 4972 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4973 !(c->closes & CLOSES_RCVD_EOF)) {
4974 /*
4975 * Received CHANNEL_CLOSE, which we translate into
4976 * outgoing EOF.
4977 */
4978 int send_close = FALSE;
4979
4980 c->closes |= CLOSES_RCVD_EOF;
4981
4982 switch (c->type) {
4983 case CHAN_X11:
4984 if (c->u.x11.s)
4985 x11_send_eof(c->u.x11.s);
4986 else
4987 send_close = TRUE;
9fb91415 4988 break;
bc06669b 4989 case CHAN_SOCKDATA:
4990 if (c->u.pfd.s)
9fb91415 4991 pfd_send_eof(c->u.pfd.s);
bc06669b 4992 else
4993 send_close = TRUE;
9fb91415 4994 break;
bc06669b 4995 case CHAN_AGENT:
4996 send_close = TRUE;
9fb91415 4997 break;
bc06669b 4998 }
51df0ab5 4999
bc06669b 5000 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5001 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5002 PKT_END);
5003 c->closes |= CLOSES_SENT_EOF;
5004 }
5005 }
5006
5007 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5008 !(c->closes & CLOSES_RCVD_CLOSE)) {
5009
5010 if (!(c->closes & CLOSES_SENT_EOF)) {
5011 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5012 " for which we never sent CHANNEL_CLOSE\n", i));
5013 }
5014
5015 c->closes |= CLOSES_RCVD_CLOSE;
5016 }
5017
5018 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5019 !(c->closes & CLOSES_SENT_CLOSE)) {
5020 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5021 PKT_INT, c->remoteid, PKT_END);
5022 c->closes |= CLOSES_SENT_CLOSE;
5023 }
5024
5025 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5026 ssh_channel_destroy(c);
51df0ab5 5027 } else {
5028 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5029 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5030 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5031 i));
5032 }
5033}
5034
5035static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5036{
5037 /* Data sent down one of our channels. */
5038 int i = ssh_pkt_getuint32(pktin);
5039 char *p;
6d44acc9 5040 int len;
51df0ab5 5041 struct ssh_channel *c;
5042
5043 ssh_pkt_getstring(pktin, &p, &len);
5044
5045 c = find234(ssh->channels, &i, ssh_channelfind);
5046 if (c) {
5047 int bufsize = 0;
5048 switch (c->type) {
5049 case CHAN_X11:
5050 bufsize = x11_send(c->u.x11.s, p, len);
5051 break;
5052 case CHAN_SOCKDATA:
5053 bufsize = pfd_send(c->u.pfd.s, p, len);
5054 break;
5055 case CHAN_AGENT:
5056 /* Data for an agent message. Buffer it. */
5057 while (len > 0) {
5058 if (c->u.a.lensofar < 4) {
62ddb51e 5059 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 5060 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5061 l);
5062 p += l;
5063 len -= l;
5064 c->u.a.lensofar += l;
5065 }
5066 if (c->u.a.lensofar == 4) {
5067 c->u.a.totallen =
5068 4 + GET_32BIT(c->u.a.msglen);
5069 c->u.a.message = snewn(c->u.a.totallen,
5070 unsigned char);
5071 memcpy(c->u.a.message, c->u.a.msglen, 4);
5072 }
5073 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 5074 unsigned int l =
51df0ab5 5075 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 5076 (unsigned)len);
51df0ab5 5077 memcpy(c->u.a.message + c->u.a.lensofar, p,
5078 l);
5079 p += l;
5080 len -= l;
5081 c->u.a.lensofar += l;
5082 }
5083 if (c->u.a.lensofar == c->u.a.totallen) {
5084 void *reply;
5085 int replylen;
be3f980d 5086 c->u.a.outstanding_requests++;
51df0ab5 5087 if (agent_query(c->u.a.message,
5088 c->u.a.totallen,
5089 &reply, &replylen,
5090 ssh_agentf_callback, c))
5091 ssh_agentf_callback(c, reply, replylen);
5092 sfree(c->u.a.message);
5093 c->u.a.lensofar = 0;
5094 }
5095 }
5096 bufsize = 0; /* agent channels never back up */
5097 break;
5098 }
ff68564b 5099 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5100 c->throttling_conn = 1;
5101 ssh_throttle_conn(ssh, +1);
51df0ab5 5102 }
5103 }
5104}
5105
5106static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5107{
51df0ab5 5108 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 5109 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 5110 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5111 /*
5112 * In case `helpful' firewalls or proxies tack
5113 * extra human-readable text on the end of the
5114 * session which we might mistake for another
5115 * encrypted packet, we close the session once
5116 * we've sent EXIT_CONFIRMATION.
5117 */
9e296bfa 5118 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 5119}
5120
c6ccd5c2 5121/* Helper function to deal with sending tty modes for REQUEST_PTY */
5122static void ssh1_send_ttymode(void *data, char *mode, char *val)
5123{
5124 struct Packet *pktout = (struct Packet *)data;
5125 int i = 0;
5126 unsigned int arg = 0;
5127 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5128 if (i == lenof(ssh_ttymodes)) return;
5129 switch (ssh_ttymodes[i].type) {
5130 case TTY_OP_CHAR:
5131 arg = ssh_tty_parse_specchar(val);
5132 break;
5133 case TTY_OP_BOOL:
5134 arg = ssh_tty_parse_boolean(val);
5135 break;
5136 }
5137 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5138 ssh2_pkt_addbyte(pktout, arg);
5139}
5140
5141
b09eaa88 5142static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5143 struct Packet *pktin)
32874aea 5144{
b09eaa88 5145 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 5146
51df0ab5 5147 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5148 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5149 ssh1_smsg_stdout_stderr_data;
5150
5151 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5152 ssh1_msg_channel_open_confirmation;
5153 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5154 ssh1_msg_channel_open_failure;
5155 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5156 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5157 ssh1_msg_channel_close;
5158 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5159 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5160
4a693cfc 5161 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 5162 logevent("Requesting agent forwarding");
51470298 5163 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 5164 do {
5165 crReturnV;
ff3187f6 5166 } while (!pktin);
5167 if (pktin->type != SSH1_SMSG_SUCCESS
5168 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5169 bombout(("Protocol confusion"));
7ffdbc1a 5170 crStopV;
ff3187f6 5171 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5172 logevent("Agent forwarding refused");
5173 } else {
5174 logevent("Agent forwarding enabled");
51470298 5175 ssh->agentfwd_enabled = TRUE;
51df0ab5 5176 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 5177 }
dacbd0e8 5178 }
5179
4a693cfc 5180 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5181 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5182 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 5183 logevent("Requesting X11 forwarding");
f68353be 5184 /*
5185 * Note that while we blank the X authentication data here, we don't
5186 * take any special action to blank the start of an X11 channel,
5187 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5188 * without having session blanking enabled is likely to leak your
5189 * cookie into the log.
5190 */
51470298 5191 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5192 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5193 PKT_STR, ssh->x11disp->remoteauthprotoname,
5194 PKTT_PASSWORD,
5195 PKT_STR, ssh->x11disp->remoteauthdatastring,
5196 PKTT_OTHER,
5197 PKT_INT, ssh->x11disp->screennum,
421d6835 5198 PKT_END);
32874aea 5199 } else {
51470298 5200 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5201 PKT_STR, ssh->x11disp->remoteauthprotoname,
5202 PKTT_PASSWORD,
5203 PKT_STR, ssh->x11disp->remoteauthdatastring,
5204 PKTT_OTHER,
5205 PKT_END);
32874aea 5206 }
5207 do {
5208 crReturnV;
ff3187f6 5209 } while (!pktin);
5210 if (pktin->type != SSH1_SMSG_SUCCESS
5211 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5212 bombout(("Protocol confusion"));
7ffdbc1a 5213 crStopV;
ff3187f6 5214 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5215 logevent("X11 forwarding refused");
5216 } else {
5217 logevent("X11 forwarding enabled");
51470298 5218 ssh->X11_fwd_enabled = TRUE;
51df0ab5 5219 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 5220 }
5221 }
5222
4a693cfc 5223 ssh_setup_portfwd(ssh, ssh->conf);
06fadff5 5224 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 5225
4a693cfc 5226 if (!conf_get_int(ssh->conf, CONF_nopty)) {
c6ccd5c2 5227 struct Packet *pkt;
a5dd8467 5228 /* Unpick the terminal-speed string. */
5229 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5230 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 5231 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5232 /* Send the pty request. */
c6ccd5c2 5233 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4a693cfc 5234 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
c6ccd5c2 5235 ssh_pkt_adduint32(pkt, ssh->term_height);
5236 ssh_pkt_adduint32(pkt, ssh->term_width);
5237 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5238 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4a693cfc 5239 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
c6ccd5c2 5240 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5241 ssh_pkt_adduint32(pkt, ssh->ispeed);
5242 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5243 ssh_pkt_adduint32(pkt, ssh->ospeed);
5244 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5245 s_wrpkt(ssh, pkt);
51470298 5246 ssh->state = SSH_STATE_INTERMED;
32874aea 5247 do {
5248 crReturnV;
ff3187f6 5249 } while (!pktin);
5250 if (pktin->type != SSH1_SMSG_SUCCESS
5251 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5252 bombout(("Protocol confusion"));
7ffdbc1a 5253 crStopV;
ff3187f6 5254 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5255 c_write_str(ssh, "Server refused to allocate pty\r\n");
5256 ssh->editing = ssh->echoing = 1;
4a202fc6 5257 } else {
5258 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5259 ssh->ospeed, ssh->ispeed);
5260 ssh->got_pty = TRUE;
5261 }
0965bee0 5262 } else {
51470298 5263 ssh->editing = ssh->echoing = 1;
374330e2 5264 }
5265
4a693cfc 5266 if (conf_get_int(ssh->conf, CONF_compression)) {
51470298 5267 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 5268 do {
5269 crReturnV;
ff3187f6 5270 } while (!pktin);
5271 if (pktin->type != SSH1_SMSG_SUCCESS
5272 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5273 bombout(("Protocol confusion"));
7ffdbc1a 5274 crStopV;
ff3187f6 5275 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5276 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 5277 }
4ba9b64b 5278 logevent("Started compression");
51470298 5279 ssh->v1_compressing = TRUE;
5366aed8 5280 ssh->cs_comp_ctx = zlib_compress_init();
5281 logevent("Initialised zlib (RFC1950) compression");
5282 ssh->sc_comp_ctx = zlib_decompress_init();
5283 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 5284 }
5285
fd5e5847 5286 /*
5287 * Start the shell or command.
5288 *
2e85c969 5289 * Special case: if the first-choice command is an SSH-2
fd5e5847 5290 * subsystem (hence not usable here) and the second choice
5291 * exists, we fall straight back to that.
5292 */
5293 {
4a693cfc 5294 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 5295
4a693cfc 5296 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5297 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5298 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
51470298 5299 ssh->fallback_cmd = TRUE;
fd5e5847 5300 }
5301 if (*cmd)
51470298 5302 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 5303 else
51470298 5304 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 5305 logevent("Started session");
5306 }
374330e2 5307
51470298 5308 ssh->state = SSH_STATE_SESSION;
5309 if (ssh->size_needed)
5310 ssh_size(ssh, ssh->term_width, ssh->term_height);
5311 if (ssh->eof_needed)
5312 ssh_special(ssh, TS_EOF);
374330e2 5313
b9d7bcad 5314 if (ssh->ldisc)
5315 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5316 ssh->send_ok = 1;
5317 ssh->channels = newtree234(ssh_channelcmp);
374330e2 5318 while (1) {
d74d141c 5319
51df0ab5 5320 /*
5321 * By this point, most incoming packets are already being
5322 * handled by the dispatch table, and we need only pay
5323 * attention to the unusual ones.
5324 */
0357890f 5325
51df0ab5 5326 crReturnV;
5327 if (pktin) {
5328 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 5329 /* may be from EXEC_SHELL on some servers */
ff3187f6 5330 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5331 /* may be from EXEC_SHELL on some servers
374330e2 5332 * if no pty is available or in other odd cases. Ignore */
374330e2 5333 } else {
ff3187f6 5334 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5335 crStopV;
374330e2 5336 }
5337 } else {
8df7a775 5338 while (inlen > 0) {
5339 int len = min(inlen, 512);
a2724fba 5340 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5341 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5342 PKTT_OTHER, PKT_END);
8df7a775 5343 in += len;
5344 inlen -= len;
5345 }
374330e2 5346 }
5347 }
5348
5349 crFinishV;
5350}
5351
5352/*
2e85c969 5353 * Handle the top-level SSH-2 protocol.
b09eaa88 5354 */
5355static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5356{
fb983202 5357 char *msg;
b09eaa88 5358 int msglen;
5359
5360 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5361 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5362}
5363
5364static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5365{
5366 /* log reason code in disconnect message */
5367 char *msg;
5368 int msglen;
5369
5370 ssh_pkt_getstring(pktin, &msg, &msglen);
5371 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5372}
5373
409bfa77 5374static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5375{
5376 /* Do nothing, because we're ignoring it! Duhh. */
5377}
5378
5379static void ssh1_protocol_setup(Ssh ssh)
5380{
5381 int i;
5382
5383 /*
5384 * Most messages are handled by the coroutines.
5385 */
5386 for (i = 0; i < 256; i++)
5387 ssh->packet_dispatch[i] = NULL;
5388
5389 /*
5390 * These special message types we install handlers for.
5391 */
5392 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5393 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5394 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5395}
5396
1c1a7262 5397static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5398 struct Packet *pktin)
5399{
1c1a7262 5400 unsigned char *in=(unsigned char*)vin;
b09eaa88 5401 if (ssh->state == SSH_STATE_CLOSED)
5402 return;
5403
5404 if (pktin && ssh->packet_dispatch[pktin->type]) {
5405 ssh->packet_dispatch[pktin->type](ssh, pktin);
5406 return;
5407 }
5408
5409 if (!ssh->protocol_initial_phase_done) {
5410 if (do_ssh1_login(ssh, in, inlen, pktin))
5411 ssh->protocol_initial_phase_done = TRUE;
5412 else
5413 return;
5414 }
5415
5416 do_ssh1_connection(ssh, in, inlen, pktin);
5417}
5418
5419/*
e5574168 5420 * Utility routine for decoding comma-separated strings in KEXINIT.
5421 */
32874aea 5422static int in_commasep_string(char *needle, char *haystack, int haylen)
5423{
57356d63 5424 int needlen;
5425 if (!needle || !haystack) /* protect against null pointers */
5426 return 0;
5427 needlen = strlen(needle);
e5574168 5428 while (1) {
32874aea 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 /*
5439 * If not, search for the next comma and resume after that.
5440 * If no comma found, terminate.
5441 */
5442 while (haylen > 0 && *haystack != ',')
5443 haylen--, haystack++;
5444 if (haylen == 0)
5445 return 0;
5446 haylen--, haystack++; /* skip over comma itself */
e5574168 5447 }
5448}
5449
5450/*
b59743d5 5451 * Similar routine for checking whether we have the first string in a list.
5452 */
5453static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5454{
5455 int needlen;
5456 if (!needle || !haystack) /* protect against null pointers */
5457 return 0;
5458 needlen = strlen(needle);
5459 /*
5460 * Is it at the start of the string?
5461 */
5462 if (haylen >= needlen && /* haystack is long enough */
5463 !memcmp(needle, haystack, needlen) && /* initial match */
5464 (haylen == needlen || haystack[needlen] == ',')
5465 /* either , or EOS follows */
5466 )
5467 return 1;
5468 return 0;
5469}
5470
5471
5472/*
2e85c969 5473 * SSH-2 key creation method.
754c0df9 5474 * (Currently assumes 2 lots of any hash are sufficient to generate
5475 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5476 */
754c0df9 5477#define SSH2_MKKEY_ITERS (2)
b672f405 5478static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5479 unsigned char *keyspace)
32874aea 5480{
b672f405 5481 const struct ssh_hash *h = ssh->kex->hash;
5482 void *s;
5483 /* First hlen bytes. */
5484 s = h->init();
51470298 5485 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5486 hash_mpint(h, s, K);
5487 h->bytes(s, H, h->hlen);
5488 h->bytes(s, &chr, 1);
5489 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5490 h->final(s, keyspace);
5491 /* Next hlen bytes. */
5492 s = h->init();
51470298 5493 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5494 hash_mpint(h, s, K);
5495 h->bytes(s, H, h->hlen);
5496 h->bytes(s, keyspace, h->hlen);
5497 h->final(s, keyspace + h->hlen);
d39f364a 5498}
5499
5500/*
2e85c969 5501 * Handle the SSH-2 transport layer.
e5574168 5502 */
0b106f61 5503static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5504 struct Packet *pktin)
e5574168 5505{
1c1a7262 5506 unsigned char *in = (unsigned char *)vin;
51470298 5507 struct do_ssh2_transport_state {
30919997 5508 int crLine;
4763c1c2 5509 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5510 Bignum p, g, e, f, K;
3dc9a6a7 5511 void *our_kexinit;
5512 int our_kexinitlen;
51470298 5513 int kex_init_value, kex_reply_value;
5514 const struct ssh_mac **maclist;
5515 int nmacs;
5516 const struct ssh2_cipher *cscipher_tobe;
5517 const struct ssh2_cipher *sccipher_tobe;
5518 const struct ssh_mac *csmac_tobe;
5519 const struct ssh_mac *scmac_tobe;
5520 const struct ssh_compress *cscomp_tobe;
5521 const struct ssh_compress *sccomp_tobe;
fae1a71b 5522 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5523 int hostkeylen, siglen, rsakeylen;
51470298 5524 void *hkey; /* actual host key */
fae1a71b 5525 void *rsakey; /* for RSA kex */
754c0df9 5526 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5527 int n_preferred_kex;
34557659 5528 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5529 int n_preferred_ciphers;
5530 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5531 const struct ssh_compress *preferred_comp;
ab18ccff 5532 int userauth_succeeded; /* for delayed compression */
5533 int pending_compression;
e13bba36 5534 int got_session_id, activated_authconn;
ff3187f6 5535 struct Packet *pktout;
3d9449a1 5536 int dlgret;
5537 int guessok;
4763c1c2 5538 int ignorepkt;
51470298 5539 };
5540 crState(do_ssh2_transport_state);
5541
30919997 5542 crBeginState;
51470298 5543
5544 s->cscipher_tobe = s->sccipher_tobe = NULL;
5545 s->csmac_tobe = s->scmac_tobe = NULL;
5546 s->cscomp_tobe = s->sccomp_tobe = NULL;
5547
e13bba36 5548 s->got_session_id = s->activated_authconn = FALSE;
ab18ccff 5549 s->userauth_succeeded = FALSE;
5550 s->pending_compression = FALSE;
e5574168 5551
e13bba36 5552 /*
5553 * Be prepared to work around the buggy MAC problem.
5554 */
5555 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5556 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5557 else
5558 s->maclist = macs, s->nmacs = lenof(macs);
5559
5560 begin_key_exchange:
acab36bc 5561 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5562 {
cc18f256 5563 int i, j, k, commalist_started;
e13bba36 5564
51470298 5565 /*
83e7d008 5566 * Set up the preferred key exchange. (NULL => warn below here)
5567 */
5568 s->n_preferred_kex = 0;
5569 for (i = 0; i < KEX_MAX; i++) {
4a693cfc 5570 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
83e7d008 5571 case KEX_DHGEX:
5572 s->preferred_kex[s->n_preferred_kex++] =
5573 &ssh_diffiehellman_gex;
5574 break;
5575 case KEX_DHGROUP14:
5576 s->preferred_kex[s->n_preferred_kex++] =
5577 &ssh_diffiehellman_group14;
5578 break;
5579 case KEX_DHGROUP1:
5580 s->preferred_kex[s->n_preferred_kex++] =
5581 &ssh_diffiehellman_group1;
5582 break;
fae1a71b 5583 case KEX_RSA:
5584 s->preferred_kex[s->n_preferred_kex++] =
5585 &ssh_rsa_kex;
5586 break;
754c0df9 5587 case KEX_WARN:
83e7d008 5588 /* Flag for later. Don't bother if it's the last in
5589 * the list. */
5590 if (i < KEX_MAX - 1) {
5591 s->preferred_kex[s->n_preferred_kex++] = NULL;
5592 }
5593 break;
5594 }
5595 }
83e7d008 5596
83e7d008 5597 /*
51470298 5598 * Set up the preferred ciphers. (NULL => warn below here)
5599 */
5600 s->n_preferred_ciphers = 0;
5601 for (i = 0; i < CIPHER_MAX; i++) {
4a693cfc 5602 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
51470298 5603 case CIPHER_BLOWFISH:
5604 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5605 break;
5606 case CIPHER_DES:
4a693cfc 5607 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
51470298 5608 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5609 }
5610 break;
5611 case CIPHER_3DES:
5612 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5613 break;
5614 case CIPHER_AES:
5615 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5616 break;
a2add208 5617 case CIPHER_ARCFOUR:
5618 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5619 break;
51470298 5620 case CIPHER_WARN:
5621 /* Flag for later. Don't bother if it's the last in
5622 * the list. */
5623 if (i < CIPHER_MAX - 1) {
5624 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5625 }
5626 break;
ca20bfcf 5627 }
ca20bfcf 5628 }
7591b9ff 5629
e13bba36 5630 /*
5631 * Set up preferred compression.
5632 */
4a693cfc 5633 if (conf_get_int(ssh->conf, CONF_compression))
e13bba36 5634 s->preferred_comp = &ssh_zlib;
5635 else
5636 s->preferred_comp = &ssh_comp_none;
51470298 5637
5638 /*
590f6a5f 5639 * Enable queueing of outgoing auth- or connection-layer
5640 * packets while we are in the middle of a key exchange.
5641 */
5642 ssh->queueing = TRUE;
5643
5644 /*
9442dd57 5645 * Flag that KEX is in progress.
5646 */
5647 ssh->kex_in_progress = TRUE;
5648
5649 /*
51470298 5650 * Construct and send our key exchange packet.
5651 */
ff3187f6 5652 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5653 for (i = 0; i < 16; i++)
ff3187f6 5654 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5655 /* List key exchange algorithms. */
ff3187f6 5656 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5657 commalist_started = 0;
5658 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5659 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5660 if (!k) continue; /* warning flag */
34557659 5661 for (j = 0; j < k->nkexes; j++) {
5662 if (commalist_started)
5663 ssh2_pkt_addstring_str(s->pktout, ",");
5664 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5665 commalist_started = 1;
5666 }
32874aea 5667 }
51470298 5668 /* List server host key algorithms. */
ff3187f6 5669 ssh2_pkt_addstring_start(s->pktout);
51470298 5670 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5671 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5672 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5673 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5674 }
cc18f256 5675 /* List encryption algorithms (client->server then server->client). */
5676 for (k = 0; k < 2; k++) {
5677 ssh2_pkt_addstring_start(s->pktout);
5678 commalist_started = 0;
5679 for (i = 0; i < s->n_preferred_ciphers; i++) {
5680 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5681 if (!c) continue; /* warning flag */
5682 for (j = 0; j < c->nciphers; j++) {
5683 if (commalist_started)
5684 ssh2_pkt_addstring_str(s->pktout, ",");
5685 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5686 commalist_started = 1;
5687 }
51470298 5688 }
5689 }
cc18f256 5690 /* List MAC algorithms (client->server then server->client). */
5691 for (j = 0; j < 2; j++) {
5692 ssh2_pkt_addstring_start(s->pktout);
5693 for (i = 0; i < s->nmacs; i++) {
5694 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5695 if (i < s->nmacs - 1)
ff3187f6 5696 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5697 }
5698 }
ab18ccff 5699 /* List client->server compression algorithms,
5700 * then server->client compression algorithms. (We use the
5701 * same set twice.) */
5702 for (j = 0; j < 2; j++) {
5703 ssh2_pkt_addstring_start(s->pktout);
5704 assert(lenof(compressions) > 1);
5705 /* Prefer non-delayed versions */
5706 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5707 /* We don't even list delayed versions of algorithms until
5708 * they're allowed to be used, to avoid a race. See the end of
5709 * this function. */
5710 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ff3187f6 5711 ssh2_pkt_addstring_str(s->pktout, ",");
ab18ccff 5712 ssh2_pkt_addstring_str(s->pktout,
5713 s->preferred_comp->delayed_name);
f6e0abe2 5714 }
ab18ccff 5715 for (i = 0; i < lenof(compressions); i++) {
5716 const struct ssh_compress *c = compressions[i];
5717 if (c != s->preferred_comp) {
5718 ssh2_pkt_addstring_str(s->pktout, ",");
5719 ssh2_pkt_addstring_str(s->pktout, c->name);
5720 if (s->userauth_succeeded && c->delayed_name) {
5721 ssh2_pkt_addstring_str(s->pktout, ",");
5722 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5723 }
5724 }
f6e0abe2 5725 }
51470298 5726 }
5727 /* List client->server languages. Empty list. */
ff3187f6 5728 ssh2_pkt_addstring_start(s->pktout);
51470298 5729 /* List server->client languages. Empty list. */
ff3187f6 5730 ssh2_pkt_addstring_start(s->pktout);
51470298 5731 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5732 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5733 /* Reserved. */
ff3187f6 5734 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5735 }
0db56f73 5736
3dc9a6a7 5737 s->our_kexinitlen = s->pktout->length - 5;
5738 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5739 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5740
590f6a5f 5741 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5742
ff3187f6 5743 if (!pktin)
0b106f61 5744 crWaitUntilV(pktin);
e5574168 5745
5746 /*
5747 * Now examine the other side's KEXINIT to see what we're up
5748 * to.
5749 */
51470298 5750 {
4763c1c2 5751 char *str, *preferred;
3d9449a1 5752 int i, j, len;
51470298 5753
ff3187f6 5754 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5755 bombout(("expected key exchange packet from server"));
0b106f61 5756 crStopV;
32874aea 5757 }
51470298 5758 ssh->kex = NULL;
5759 ssh->hostkey = NULL;
5760 s->cscipher_tobe = NULL;
5761 s->sccipher_tobe = NULL;
5762 s->csmac_tobe = NULL;
5763 s->scmac_tobe = NULL;
5764 s->cscomp_tobe = NULL;
5765 s->sccomp_tobe = NULL;
4763c1c2 5766 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5767
ff3187f6 5768 pktin->savedpos += 16; /* skip garbage cookie */
5769 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5770
5771 preferred = NULL;
83e7d008 5772 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5773 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5774 if (!k) {
4763c1c2 5775 s->warn_kex = TRUE;
5776 } else {
34557659 5777 for (j = 0; j < k->nkexes; j++) {
5778 if (!preferred) preferred = k->list[j]->name;
5779 if (in_commasep_string(k->list[j]->name, str, len)) {
5780 ssh->kex = k->list[j];
5781 break;
5782 }
5783 }
83e7d008 5784 }
4763c1c2 5785 if (ssh->kex)
51470298 5786 break;
32874aea 5787 }
83e7d008 5788 if (!ssh->kex) {
5789 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5790 str ? str : "(null)"));
0b106f61 5791 crStopV;
83e7d008 5792 }
b59743d5 5793 /*
5794 * Note that the server's guess is considered wrong if it doesn't match
5795 * the first algorithm in our list, even if it's still the algorithm
5796 * we end up using.
5797 */
4763c1c2 5798 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5799 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5800 for (i = 0; i < lenof(hostkey_algs); i++) {
5801 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5802 ssh->hostkey = hostkey_algs[i];
5803 break;
5804 }
5805 }
fc40b431 5806 if (!ssh->hostkey) {
5807 bombout(("Couldn't agree a host key algorithm (available: %s)",
5808 str ? str : "(null)"));
0b106f61 5809 crStopV;
fc40b431 5810 }
5811
3d9449a1 5812 s->guessok = s->guessok &&
b59743d5 5813 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5814 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5815 for (i = 0; i < s->n_preferred_ciphers; i++) {
5816 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5817 if (!c) {
4763c1c2 5818 s->warn_cscipher = TRUE;
51470298 5819 } else {
5820 for (j = 0; j < c->nciphers; j++) {
5821 if (in_commasep_string(c->list[j]->name, str, len)) {
5822 s->cscipher_tobe = c->list[j];
5823 break;
5824 }
ca20bfcf 5825 }
32874aea 5826 }
4763c1c2 5827 if (s->cscipher_tobe)
51470298 5828 break;
32874aea 5829 }
51470298 5830 if (!s->cscipher_tobe) {
6b5cf8b4 5831 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5832 str ? str : "(null)"));
0b106f61 5833 crStopV;
ca20bfcf 5834 }
0ef8f407 5835
ff3187f6 5836 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5837 for (i = 0; i < s->n_preferred_ciphers; i++) {
5838 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5839 if (!c) {
4763c1c2 5840 s->warn_sccipher = TRUE;
51470298 5841 } else {
5842 for (j = 0; j < c->nciphers; j++) {
5843 if (in_commasep_string(c->list[j]->name, str, len)) {
5844 s->sccipher_tobe = c->list[j];
5845 break;
5846 }
ca20bfcf 5847 }
32874aea 5848 }
4763c1c2 5849 if (s->sccipher_tobe)
51470298 5850 break;
32874aea 5851 }
51470298 5852 if (!s->sccipher_tobe) {
6b5cf8b4 5853 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5854 str ? str : "(null)"));
0b106f61 5855 crStopV;
ca20bfcf 5856 }
0ef8f407 5857
ff3187f6 5858 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5859 for (i = 0; i < s->nmacs; i++) {
5860 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5861 s->csmac_tobe = s->maclist[i];
5862 break;
5863 }
32874aea 5864 }
ff3187f6 5865 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5866 for (i = 0; i < s->nmacs; i++) {
5867 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5868 s->scmac_tobe = s->maclist[i];
5869 break;
5870 }
32874aea 5871 }
ff3187f6 5872 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5873 for (i = 0; i < lenof(compressions) + 1; i++) {
5874 const struct ssh_compress *c =
5875 i == 0 ? s->preferred_comp : compressions[i - 1];
5876 if (in_commasep_string(c->name, str, len)) {
5877 s->cscomp_tobe = c;
5878 break;
ab18ccff 5879 } else if (in_commasep_string(c->delayed_name, str, len)) {
5880 if (s->userauth_succeeded) {
5881 s->cscomp_tobe = c;
5882 break;
5883 } else {
5884 s->pending_compression = TRUE; /* try this later */
5885 }
51470298 5886 }
32874aea 5887 }
ff3187f6 5888 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5889 for (i = 0; i < lenof(compressions) + 1; i++) {
5890 const struct ssh_compress *c =
5891 i == 0 ? s->preferred_comp : compressions[i - 1];
5892 if (in_commasep_string(c->name, str, len)) {
5893 s->sccomp_tobe = c;
5894 break;
ab18ccff 5895 } else if (in_commasep_string(c->delayed_name, str, len)) {
5896 if (s->userauth_succeeded) {
5897 s->sccomp_tobe = c;
5898 break;
5899 } else {
5900 s->pending_compression = TRUE; /* try this later */
5901 }
51470298 5902 }
32874aea 5903 }
ab18ccff 5904 if (s->pending_compression) {
5905 logevent("Server supports delayed compression; "
5906 "will try this later");
5907 }
b59743d5 5908 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5909 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5910 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5911
42fee8d6 5912 ssh->exhash = ssh->kex->hash->init();
5913 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5914 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5915 hash_string(ssh->kex->hash, ssh->exhash,
5916 s->our_kexinit, s->our_kexinitlen);
5917 sfree(s->our_kexinit);
5918 if (pktin->length > 5)
5919 hash_string(ssh->kex->hash, ssh->exhash,
5920 pktin->data + 5, pktin->length - 5);
5921
4763c1c2 5922 if (s->warn_kex) {
5923 ssh_set_frozen(ssh, 1);
5924 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5925 ssh->kex->name,
5926 ssh_dialog_callback, ssh);
5927 if (s->dlgret < 0) {
5928 do {
0b106f61 5929 crReturnV;
4763c1c2 5930 if (pktin) {
5931 bombout(("Unexpected data from server while"
5932 " waiting for user response"));
0b106f61 5933 crStopV;
4763c1c2 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 kex warning", NULL,
5941 0, TRUE);
0b106f61 5942 crStopV;
4763c1c2 5943 }
5944 }
5945
5946 if (s->warn_cscipher) {
5947 ssh_set_frozen(ssh, 1);
5948 s->dlgret = askalg(ssh->frontend,
5949 "client-to-server cipher",
5950 s->cscipher_tobe->name,
5951 ssh_dialog_callback, ssh);
5952 if (s->dlgret < 0) {
5953 do {
0b106f61 5954 crReturnV;
4763c1c2 5955 if (pktin) {
5956 bombout(("Unexpected data from server while"
5957 " waiting for user response"));
0b106f61 5958 crStopV;
4763c1c2 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);
0b106f61 5967 crStopV;
4763c1c2 5968 }
5969 }
5970
5971 if (s->warn_sccipher) {
5972 ssh_set_frozen(ssh, 1);
5973 s->dlgret = askalg(ssh->frontend,
5974 "server-to-client cipher",
5975 s->sccipher_tobe->name,
5976 ssh_dialog_callback, ssh);
5977 if (s->dlgret < 0) {
5978 do {
0b106f61 5979 crReturnV;
4763c1c2 5980 if (pktin) {
5981 bombout(("Unexpected data from server while"
5982 " waiting for user response"));
0b106f61 5983 crStopV;
4763c1c2 5984 }
5985 } while (pktin || inlen > 0);
5986 s->dlgret = ssh->user_response;
5987 }
5988 ssh_set_frozen(ssh, 0);
5989 if (s->dlgret == 0) {
9e296bfa 5990 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5991 0, TRUE);
0b106f61 5992 crStopV;
4763c1c2 5993 }
5994 }
5995
5996 if (s->ignorepkt) /* first_kex_packet_follows */
0b106f61 5997 crWaitUntilV(pktin); /* Ignore packet */
e5574168 5998 }
e5574168 5999
fae1a71b 6000 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 6001 /*
6002 * Work out the number of bits of key we will need from the
6003 * key exchange. We start with the maximum key length of
6004 * either cipher...
6005 */
6006 {
6007 int csbits, scbits;
6008
6009 csbits = s->cscipher_tobe->keylen;
6010 scbits = s->sccipher_tobe->keylen;
6011 s->nbits = (csbits > scbits ? csbits : scbits);
6012 }
6013 /* The keys only have hlen-bit entropy, since they're based on
6014 * a hash. So cap the key size at hlen bits. */
6015 if (s->nbits > ssh->kex->hash->hlen * 8)
6016 s->nbits = ssh->kex->hash->hlen * 8;
6017
6018 /*
6019 * If we're doing Diffie-Hellman group exchange, start by
6020 * requesting a group.
6021 */
6022 if (!ssh->kex->pdata) {
6023 logevent("Doing Diffie-Hellman group exchange");
acab36bc 6024 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 6025 /*
6026 * Work out how big a DH group we will need to allow that
6027 * much data.
6028 */
6029 s->pbits = 512 << ((s->nbits - 1) / 64);
6030 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6031 ssh2_pkt_adduint32(s->pktout, s->pbits);
6032 ssh2_pkt_send_noqueue(ssh, s->pktout);
6033
0b106f61 6034 crWaitUntilV(pktin);
30774ba3 6035 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6036 bombout(("expected key exchange group packet from server"));
0b106f61 6037 crStopV;
30774ba3 6038 }
6039 s->p = ssh2_pkt_getmp(pktin);
6040 s->g = ssh2_pkt_getmp(pktin);
6041 if (!s->p || !s->g) {
6042 bombout(("unable to read mp-ints from incoming group packet"));
0b106f61 6043 crStopV;
30774ba3 6044 }
6045 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6046 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6047 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6048 } else {
acab36bc 6049 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 6050 ssh->kex_ctx = dh_setup_group(ssh->kex);
6051 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6052 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6053 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6054 ssh->kex->groupname);
6055 }
e5574168 6056
30774ba3 6057 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6058 ssh->kex->hash->text_name);
6059 /*
6060 * Now generate and send e for Diffie-Hellman.
6061 */
6062 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6063 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6064 s->pktout = ssh2_pkt_init(s->kex_init_value);
6065 ssh2_pkt_addmp(s->pktout, s->e);
6066 ssh2_pkt_send_noqueue(ssh, s->pktout);
6067
6068 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
0b106f61 6069 crWaitUntilV(pktin);
30774ba3 6070 if (pktin->type != s->kex_reply_value) {
6071 bombout(("expected key exchange reply packet from server"));
0b106f61 6072 crStopV;
30774ba3 6073 }
6074 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6075 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6076 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6077 s->f = ssh2_pkt_getmp(pktin);
6078 if (!s->f) {
6079 bombout(("unable to parse key exchange reply packet"));
0b106f61 6080 crStopV;
30774ba3 6081 }
6082 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 6083
30774ba3 6084 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 6085
30774ba3 6086 /* We assume everything from now on will be quick, and it might
6087 * involve user interaction. */
6088 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 6089
30774ba3 6090 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6091 if (!ssh->kex->pdata) {
6092 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6093 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6094 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6095 }
6096 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6097 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6098
6099 dh_cleanup(ssh->kex_ctx);
6100 freebn(s->f);
6101 if (!ssh->kex->pdata) {
6102 freebn(s->g);
6103 freebn(s->p);
6104 }
fae1a71b 6105 } else {
6106 logeventf(ssh, "Doing RSA key exchange with hash %s",
6107 ssh->kex->hash->text_name);
acab36bc 6108 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 6109 /*
6110 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6111 * from the server.
6112 */
0b106f61 6113 crWaitUntilV(pktin);
fae1a71b 6114 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6115 bombout(("expected RSA public key packet from server"));
0b106f61 6116 crStopV;
fae1a71b 6117 }
6118
6119 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6120 hash_string(ssh->kex->hash, ssh->exhash,
6121 s->hostkeydata, s->hostkeylen);
6122 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6123
6124 {
6125 char *keydata;
6126 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6127 s->rsakeydata = snewn(s->rsakeylen, char);
6128 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6129 }
6130
6131 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6132 if (!s->rsakey) {
6133 sfree(s->rsakeydata);
6134 bombout(("unable to parse RSA public key from server"));
0b106f61 6135 crStopV;
fae1a71b 6136 }
6137
6138 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6139
6140 /*
6141 * Next, set up a shared secret K, of precisely KLEN -
6142 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6143 * RSA key modulus and HLEN is the bit length of the hash
6144 * we're using.
6145 */
6146 {
6147 int klen = ssh_rsakex_klen(s->rsakey);
6148 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6149 int i, byte = 0;
6150 unsigned char *kstr1, *kstr2, *outstr;
6151 int kstr1len, kstr2len, outstrlen;
6152
6153 s->K = bn_power_2(nbits - 1);
6154
6155 for (i = 0; i < nbits; i++) {
6156 if ((i & 7) == 0) {
6157 byte = random_byte();
6158 }
6159 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6160 }
6161
6162 /*
6163 * Encode this as an mpint.
6164 */
6165 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6166 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6167 PUT_32BIT(kstr2, kstr1len);
6168 memcpy(kstr2 + 4, kstr1, kstr1len);
6169
6170 /*
6171 * Encrypt it with the given RSA key.
6172 */
6173 outstrlen = (klen + 7) / 8;
6174 outstr = snewn(outstrlen, unsigned char);
6175 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6176 outstr, outstrlen, s->rsakey);
6177
6178 /*
6179 * And send it off in a return packet.
6180 */
6181 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6182 ssh2_pkt_addstring_start(s->pktout);
7108a872 6183 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 6184 ssh2_pkt_send_noqueue(ssh, s->pktout);
6185
6186 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6187
6188 sfree(kstr2);
6189 sfree(kstr1);
6190 sfree(outstr);
6191 }
6192
6193 ssh_rsakex_freekey(s->rsakey);
6194
0b106f61 6195 crWaitUntilV(pktin);
fae1a71b 6196 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6197 sfree(s->rsakeydata);
6198 bombout(("expected signature packet from server"));
0b106f61 6199 crStopV;
fae1a71b 6200 }
6201
6202 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6203
6204 sfree(s->rsakeydata);
6205 }
6206
b672f405 6207 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6208 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6209 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 6210
fabd1805 6211 ssh->kex_ctx = NULL;
3709bfe9 6212
7cca0d81 6213#if 0
765c4200 6214 debug(("Exchange hash is:\n"));
b672f405 6215 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 6216#endif
6217
51470298 6218 if (!s->hkey ||
6219 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 6220 (char *)s->exchange_hash,
6221 ssh->kex->hash->hlen)) {
6b5cf8b4 6222 bombout(("Server's host key did not match the signature supplied"));
0b106f61 6223 crStopV;
8d5de777 6224 }
e5574168 6225
6226 /*
7cca0d81 6227 * Authenticate remote host: verify host key. (We've already
6228 * checked the signature of the exchange hash.)
e5574168 6229 */
51470298 6230 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6231 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 6232 ssh_set_frozen(ssh, 1);
6233 s->dlgret = verify_ssh_host_key(ssh->frontend,
6234 ssh->savedhost, ssh->savedport,
6235 ssh->hostkey->keytype, s->keystr,
6236 s->fingerprint,
6237 ssh_dialog_callback, ssh);
6238 if (s->dlgret < 0) {
6239 do {
0b106f61 6240 crReturnV;
3d9449a1 6241 if (pktin) {
6242 bombout(("Unexpected data from server while waiting"
6243 " for user host key response"));
0b106f61 6244 crStopV;
3d9449a1 6245 }
6246 } while (pktin || inlen > 0);
6247 s->dlgret = ssh->user_response;
6248 }
6249 ssh_set_frozen(ssh, 0);
6250 if (s->dlgret == 0) {
9e296bfa 6251 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6252 0, TRUE);
0b106f61 6253 crStopV;
3d9449a1 6254 }
e13bba36 6255 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 6256 logevent("Host key fingerprint is:");
51470298 6257 logevent(s->fingerprint);
5e0d7cb8 6258 }
51470298 6259 sfree(s->fingerprint);
6260 sfree(s->keystr);
6261 ssh->hostkey->freekey(s->hkey);
d39f364a 6262
6263 /*
9442dd57 6264 * The exchange hash from the very first key exchange is also
6265 * the session id, used in session key construction and
6266 * authentication.
6267 */
e13bba36 6268 if (!s->got_session_id) {
b672f405 6269 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 6270 memcpy(ssh->v2_session_id, s->exchange_hash,
6271 sizeof(s->exchange_hash));
b672f405 6272 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 6273 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 6274 s->got_session_id = TRUE;
6275 }
9442dd57 6276
6277 /*
7cca0d81 6278 * Send SSH2_MSG_NEWKEYS.
d39f364a 6279 */
ff3187f6 6280 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 6281 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 6282 ssh->outgoing_data_size = 0; /* start counting from here */
6283
6284 /*
6285 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 6286 * client-to-server session keys.
9442dd57 6287 */
6288 if (ssh->cs_cipher_ctx)
6289 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6290 ssh->cscipher = s->cscipher_tobe;
6291 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6292
6293 if (ssh->cs_mac_ctx)
6294 ssh->csmac->free_context(ssh->cs_mac_ctx);
6295 ssh->csmac = s->csmac_tobe;
6296 ssh->cs_mac_ctx = ssh->csmac->make_context();
6297
6298 if (ssh->cs_comp_ctx)
6299 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6300 ssh->cscomp = s->cscomp_tobe;
6301 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6302
6303 /*
6304 * Set IVs on client-to-server keys. Here we use the exchange
6305 * hash from the _first_ key exchange.
6306 */
6307 {
754c0df9 6308 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6309 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6310 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 6311 assert((ssh->cscipher->keylen+7) / 8 <=
6312 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6313 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 6314 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 6315 assert(ssh->cscipher->blksize <=
6316 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6317 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 6318 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 6319 assert(ssh->csmac->len <=
6320 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6321 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
dfb88efd 6322 smemclr(keyspace, sizeof(keyspace));
9442dd57 6323 }
6324
6325 logeventf(ssh, "Initialised %.200s client->server encryption",
6326 ssh->cscipher->text_name);
6327 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6328 ssh->csmac->text_name);
6329 if (ssh->cscomp->text_name)
6330 logeventf(ssh, "Initialised %s compression",
6331 ssh->cscomp->text_name);
590f6a5f 6332
6333 /*
6334 * Now our end of the key exchange is complete, we can send all
6335 * our queued higher-layer packets.
6336 */
6337 ssh->queueing = FALSE;
6338 ssh2_pkt_queuesend(ssh);
d39f364a 6339
6340 /*
8406eaf9 6341 * Expect SSH2_MSG_NEWKEYS from server.
6342 */
0b106f61 6343 crWaitUntilV(pktin);
ff3187f6 6344 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 6345 bombout(("expected new-keys packet from server"));
0b106f61 6346 crStopV;
8406eaf9 6347 }
9442dd57 6348 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 6349
6350 /*
9442dd57 6351 * We've seen server NEWKEYS, so create and initialise
6352 * server-to-client session keys.
d39f364a 6353 */
371e569c 6354 if (ssh->sc_cipher_ctx)
6355 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6356 ssh->sccipher = s->sccipher_tobe;
371e569c 6357 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6358
e0e1a00d 6359 if (ssh->sc_mac_ctx)
6360 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6361 ssh->scmac = s->scmac_tobe;
e0e1a00d 6362 ssh->sc_mac_ctx = ssh->scmac->make_context();
6363
5366aed8 6364 if (ssh->sc_comp_ctx)
6365 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6366 ssh->sccomp = s->sccomp_tobe;
5366aed8 6367 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6368
d39f364a 6369 /*
9442dd57 6370 * Set IVs on server-to-client keys. Here we use the exchange
6371 * hash from the _first_ key exchange.
d39f364a 6372 */
51470298 6373 {
754c0df9 6374 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6375 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6376 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6377 assert((ssh->sccipher->keylen+7) / 8 <=
6378 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6379 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6380 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6381 assert(ssh->sccipher->blksize <=
6382 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6383 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6384 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6385 assert(ssh->scmac->len <=
6386 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6387 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
dfb88efd 6388 smemclr(keyspace, sizeof(keyspace));
51470298 6389 }
57356d63 6390 logeventf(ssh, "Initialised %.200s server->client encryption",
6391 ssh->sccipher->text_name);
6c135243 6392 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6393 ssh->scmac->text_name);
57356d63 6394 if (ssh->sccomp->text_name)
6395 logeventf(ssh, "Initialised %s decompression",
6396 ssh->sccomp->text_name);
9442dd57 6397
6398 /*
fae1a71b 6399 * Free shared secret.
9442dd57 6400 */
679539d7 6401 freebn(s->K);
d39f364a 6402
033b4cef 6403 /*
e13bba36 6404 * Key exchange is over. Loop straight back round if we have a
6405 * deferred rekey reason.
6406 */
6407 if (ssh->deferred_rekey_reason) {
6408 logevent(ssh->deferred_rekey_reason);
6409 pktin = NULL;
6410 ssh->deferred_rekey_reason = NULL;
6411 goto begin_key_exchange;
6412 }
6413
6414 /*
6415 * Otherwise, schedule a timer for our next rekey.
9442dd57 6416 */
6417 ssh->kex_in_progress = FALSE;
e6c1536e 6418 ssh->last_rekey = GETTICKCOUNT();
4a693cfc 6419 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6420 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
d57f70af 6421 ssh2_timer, ssh);
e13bba36 6422
9442dd57 6423 /*
7cca0d81 6424 * Now we're encrypting. Begin returning 1 to the protocol main
6425 * function so that other things can run on top of the
6426 * transport. If we ever see a KEXINIT, we must go back to the
6427 * start.
9442dd57 6428 *
6429 * We _also_ go back to the start if we see pktin==NULL and
ab18ccff 6430 * inlen negative, because this is a special signal meaning
9442dd57 6431 * `initiate client-driven rekey', and `in' contains a message
6432 * giving the reason for the rekey.
ab18ccff 6433 *
6434 * inlen==-1 means always initiate a rekey;
6435 * inlen==-2 means that userauth has completed successfully and
6436 * we should consider rekeying (for delayed compression).
033b4cef 6437 */
9442dd57 6438 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
ab18ccff 6439 (!pktin && inlen < 0))) {
f382c87d 6440 wait_for_rekey:
bc074147 6441 if (!ssh->protocol_initial_phase_done) {
6442 ssh->protocol_initial_phase_done = TRUE;
6443 /*
6444 * Allow authconn to initialise itself.
6445 */
6446 do_ssh2_authconn(ssh, NULL, 0, NULL);
6447 }
0b106f61 6448 crReturnV;
e96adf72 6449 }
9442dd57 6450 if (pktin) {
6451 logevent("Server initiated key re-exchange");
6452 } else {
ab18ccff 6453 if (inlen == -2) {
6454 /*
6455 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6456 * delayed compression, if it's available.
6457 *
6458 * draft-miller-secsh-compression-delayed-00 says that you
6459 * negotiate delayed compression in the first key exchange, and
6460 * both sides start compressing when the server has sent
6461 * USERAUTH_SUCCESS. This has a race condition -- the server
6462 * can't know when the client has seen it, and thus which incoming
6463 * packets it should treat as compressed.
6464 *
6465 * Instead, we do the initial key exchange without offering the
6466 * delayed methods, but note if the server offers them; when we
6467 * get here, if a delayed method was available that was higher
6468 * on our list than what we got, we initiate a rekey in which we
6469 * _do_ list the delayed methods (and hopefully get it as a
6470 * result). Subsequent rekeys will do the same.
6471 */
6472 assert(!s->userauth_succeeded); /* should only happen once */
6473 s->userauth_succeeded = TRUE;
6474 if (!s->pending_compression)
6475 /* Can't see any point rekeying. */
6476 goto wait_for_rekey; /* this is utterly horrid */
6477 /* else fall through to rekey... */
6478 s->pending_compression = FALSE;
6479 }
f382c87d 6480 /*
ab18ccff 6481 * Now we've decided to rekey.
6482 *
f382c87d 6483 * Special case: if the server bug is set that doesn't
6484 * allow rekeying, we give a different log message and
6485 * continue waiting. (If such a server _initiates_ a rekey,
6486 * we process it anyway!)
6487 */
6488 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6489 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6490 (char *)in);
6491 /* Reset the counters, so that at least this message doesn't
6492 * hit the event log _too_ often. */
6493 ssh->outgoing_data_size = 0;
6494 ssh->incoming_data_size = 0;
4a693cfc 6495 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
f382c87d 6496 ssh->next_rekey =
4a693cfc 6497 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
f382c87d 6498 ssh2_timer, ssh);
6499 }
ab18ccff 6500 goto wait_for_rekey; /* this is still utterly horrid */
f382c87d 6501 } else {
6502 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6503 }
9442dd57 6504 }
7cca0d81 6505 goto begin_key_exchange;
e5574168 6506
0b106f61 6507 crFinishV;
e5574168 6508}
6509
7cca0d81 6510/*
2e85c969 6511 * Add data to an SSH-2 channel output buffer.
783415f8 6512 */
32874aea 6513static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6514 int len)
6515{
5471d09a 6516 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6517}
6518
6519/*
2e85c969 6520 * Attempt to send data on an SSH-2 channel.
783415f8 6521 */
5471d09a 6522static int ssh2_try_send(struct ssh_channel *c)
32874aea 6523{
51470298 6524 Ssh ssh = c->ssh;
ff3187f6 6525 struct Packet *pktout;
bc06669b 6526 int ret;
51470298 6527
5471d09a 6528 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6529 int len;
6530 void *data;
6531 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6532 if ((unsigned)len > c->v.v2.remwindow)
6533 len = c->v.v2.remwindow;
6534 if ((unsigned)len > c->v.v2.remmaxpkt)
6535 len = c->v.v2.remmaxpkt;
ff3187f6 6536 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6537 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6538 ssh2_pkt_addstring_start(pktout);
a2724fba 6539 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6540 ssh2_pkt_addstring_data(pktout, data, len);
6541 end_log_omission(ssh, pktout);
6542 ssh2_pkt_send(ssh, pktout);
5471d09a 6543 bufchain_consume(&c->v.v2.outbuffer, len);
6544 c->v.v2.remwindow -= len;
6545 }
6546
6547 /*
6548 * After having sent as much data as we can, return the amount
6549 * still buffered.
6550 */
bc06669b 6551 ret = bufchain_size(&c->v.v2.outbuffer);
6552
6553 /*
6554 * And if there's no data pending but we need to send an EOF, send
6555 * it.
6556 */
6557 if (!ret && c->pending_eof)
6558 ssh_channel_try_eof(c);
6559
6560 return ret;
5471d09a 6561}
6562
78280721 6563static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
1bfc7e93 6564{
6565 int bufsize;
bc06669b 6566 if (c->closes & CLOSES_SENT_EOF)
6567 return; /* don't send on channels we've EOFed */
1bfc7e93 6568 bufsize = ssh2_try_send(c);
6569 if (bufsize == 0) {
6570 switch (c->type) {
6571 case CHAN_MAINSESSION:
6572 /* stdin need not receive an unthrottle
6573 * notification since it will be polled */
6574 break;
6575 case CHAN_X11:
6576 x11_unthrottle(c->u.x11.s);
6577 break;
6578 case CHAN_AGENT:
6579 /* agent sockets are request/response and need no
6580 * buffer management */
6581 break;
6582 case CHAN_SOCKDATA:
6583 pfd_unthrottle(c->u.pfd.s);
6584 break;
6585 }
6586 }
6587}
6588
5471d09a 6589/*
94bdfe40 6590 * Set up most of a new ssh_channel for SSH-2.
6591 */
6592static void ssh2_channel_init(struct ssh_channel *c)
6593{
6594 Ssh ssh = c->ssh;
6595 c->localid = alloc_channel_id(ssh);
6596 c->closes = 0;
bc06669b 6597 c->pending_eof = FALSE;
94bdfe40 6598 c->throttling_conn = FALSE;
6599 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
4a693cfc 6600 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
39d830e4 6601 c->v.v2.chanreq_head = NULL;
94bdfe40 6602 c->v.v2.throttle_state = UNTHROTTLED;
6603 bufchain_init(&c->v.v2.outbuffer);
6604}
6605
6606/*
4a62c66d 6607 * Construct the common parts of a CHANNEL_OPEN.
6608 */
6609static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6610{
6611 struct Packet *pktout;
6612
6613 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6614 ssh2_pkt_addstring(pktout, type);
6615 ssh2_pkt_adduint32(pktout, c->localid);
6616 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6617 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6618 return pktout;
6619}
6620
6621/*
39d830e4 6622 * CHANNEL_FAILURE doesn't come with any indication of what message
6623 * caused it, so we have to keep track of the outstanding
6624 * CHANNEL_REQUESTs ourselves.
6625 */
6626static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6627 cchandler_fn_t handler, void *ctx)
6628{
6629 struct outstanding_channel_request *ocr =
6630 snew(struct outstanding_channel_request);
6631
3620f307 6632 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
39d830e4 6633 ocr->handler = handler;
6634 ocr->ctx = ctx;
6635 ocr->next = NULL;
6636 if (!c->v.v2.chanreq_head)
6637 c->v.v2.chanreq_head = ocr;
6638 else
6639 c->v.v2.chanreq_tail->next = ocr;
6640 c->v.v2.chanreq_tail = ocr;
6641}
6642
6643/*
134f5ece 6644 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6645 * NULL then a reply will be requested and the handler will be called
6646 * when it arrives. The returned packet is ready to have any
6647 * request-specific data added and be sent. Note that if a handler is
6648 * provided, it's essential that the request actually be sent.
3620f307 6649 *
6650 * The handler will usually be passed the response packet in pktin.
6651 * If pktin is NULL, this means that no reply will ever be forthcoming
6652 * (e.g. because the entire connection is being destroyed) and the
6653 * handler should free any storage it's holding.
134f5ece 6654 */
6655static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6656 cchandler_fn_t handler, void *ctx)
6657{
6658 struct Packet *pktout;
6659
3620f307 6660 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
134f5ece 6661 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6662 ssh2_pkt_adduint32(pktout, c->remoteid);
6663 ssh2_pkt_addstring(pktout, type);
6664 ssh2_pkt_addbool(pktout, handler != NULL);
6665 if (handler != NULL)
6666 ssh2_queue_chanreq_handler(c, handler, ctx);
6667 return pktout;
6668}
6669
6670/*
2e85c969 6671 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6672 */
39d830e4 6673static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6674 void *);
9fca3f8c 6675static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6676{
51470298 6677 Ssh ssh = c->ssh;
6678
6b69f42e 6679 /*
bc06669b 6680 * Never send WINDOW_ADJUST for a channel that the remote side has
6681 * already sent EOF on; there's no point, since it won't be
beff003a 6682 * sending any more data anyway. Ditto if _we've_ already sent
6683 * CLOSE.
6b69f42e 6684 */
beff003a 6685 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6b69f42e 6686 return;
6687
d252310a 6688 /*
c9739dba 6689 * If the remote end has a habit of ignoring maxpkt, limit the
6690 * window so that it has no choice (assuming it doesn't ignore the
6691 * window as well).
6692 */
6693 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6694 newwin = OUR_V2_MAXPKT;
c9739dba 6695
6696 /*
d252310a 6697 * Only send a WINDOW_ADJUST if there's significantly more window
6698 * available than the other end thinks there is. This saves us
6699 * sending a WINDOW_ADJUST for every character in a shell session.
6700 *
6701 * "Significant" is arbitrarily defined as half the window size.
6702 */
3361b80a 6703 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6704 struct Packet *pktout;
39d830e4 6705 unsigned *up;
ff3187f6 6706
0e443c99 6707 /*
6708 * In order to keep track of how much window the client
6709 * actually has available, we'd like it to acknowledge each
6710 * WINDOW_ADJUST. We can't do that directly, so we accompany
6711 * it with a CHANNEL_REQUEST that has to be acknowledged.
6712 *
6713 * This is only necessary if we're opening the window wide.
6714 * If we're not, then throughput is being constrained by
6715 * something other than the maximum window size anyway.
0e443c99 6716 */
6717 if (newwin == c->v.v2.locmaxwin &&
2e0aae4f 6718 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
39d830e4 6719 up = snew(unsigned);
6720 *up = newwin - c->v.v2.locwindow;
134f5ece 6721 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6722 ssh2_handle_winadj_response, up);
6723 ssh2_pkt_send(ssh, pktout);
6724
0e443c99 6725 if (c->v.v2.throttle_state != UNTHROTTLED)
6726 c->v.v2.throttle_state = UNTHROTTLING;
6727 } else {
6728 /* Pretend the WINDOW_ADJUST was acked immediately. */
6729 c->v.v2.remlocwin = newwin;
6730 c->v.v2.throttle_state = THROTTLED;
6731 }
ff3187f6 6732 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6733 ssh2_pkt_adduint32(pktout, c->remoteid);
6734 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6735 ssh2_pkt_send(ssh, pktout);
5471d09a 6736 c->v.v2.locwindow = newwin;
783415f8 6737 }
6738}
6739
e223b7c7 6740/*
6741 * Find the channel associated with a message. If there's no channel,
6742 * or it's not properly open, make a noise about it and return NULL.
6743 */
6744static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6745{
6746 unsigned localid = ssh_pkt_getuint32(pktin);
6747 struct ssh_channel *c;
6748
6749 c = find234(ssh->channels, &localid, ssh_channelfind);
6750 if (!c ||
6751 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6752 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6753 char *buf = dupprintf("Received %s for %s channel %u",
6754 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6755 pktin->type),
6756 c ? "half-open" : "nonexistent", localid);
6757 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6758 sfree(buf);
6759 return NULL;
6760 }
6761 return c;
6762}
6763
39d830e4 6764static void ssh2_handle_winadj_response(struct ssh_channel *c,
6765 struct Packet *pktin, void *ctx)
e030765f 6766{
39d830e4 6767 unsigned *sizep = ctx;
6768
6769 /*
6770 * Winadj responses should always be failures. However, at least
6771 * one server ("boks_sshd") is known to return SUCCESS for channel
6772 * requests it's never heard of, such as "winadj@putty". Raised
6773 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6774 * life, we don't worry about what kind of response we got.
6775 */
6776
6777 c->v.v2.remlocwin += *sizep;
6778 sfree(sizep);
e030765f 6779 /*
6780 * winadj messages are only sent when the window is fully open, so
6781 * if we get an ack of one, we know any pending unthrottle is
6782 * complete.
6783 */
6784 if (c->v.v2.throttle_state == UNTHROTTLING)
6785 c->v.v2.throttle_state = UNTHROTTLED;
e030765f 6786}
6787
39d830e4 6788static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
837d6ba6 6789{
39d830e4 6790 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6791 struct outstanding_channel_request *ocr;
837d6ba6 6792
39d830e4 6793 if (!c) return;
6794 ocr = c->v.v2.chanreq_head;
6795 if (!ocr) {
6796 ssh2_msg_unexpected(ssh, pktin);
837d6ba6 6797 return;
39d830e4 6798 }
6799 ocr->handler(c, pktin, ocr->ctx);
6800 c->v.v2.chanreq_head = ocr->next;
6801 sfree(ocr);
0e443c99 6802 /*
39d830e4 6803 * We may now initiate channel-closing procedures, if that
6804 * CHANNEL_REQUEST was the last thing outstanding before we send
6805 * CHANNEL_CLOSE.
0e443c99 6806 */
39d830e4 6807 ssh2_channel_check_close(c);
0e443c99 6808}
6809
51df0ab5 6810static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6811{
b09eaa88 6812 struct ssh_channel *c;
e223b7c7 6813 c = ssh2_channel_msg(ssh, pktin);
6814 if (!c)
6815 return;
bc06669b 6816 if (!(c->closes & CLOSES_SENT_EOF)) {
b09eaa88 6817 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
78280721 6818 ssh2_try_send_and_unthrottle(ssh, c);
1bfc7e93 6819 }
b09eaa88 6820}
6821
51df0ab5 6822static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6823{
6824 char *data;
6d44acc9 6825 int length;
51df0ab5 6826 struct ssh_channel *c;
e223b7c7 6827 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 6828 if (!c)
e223b7c7 6829 return;
51df0ab5 6830 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6831 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6832 return; /* extended but not stderr */
6833 ssh_pkt_getstring(pktin, &data, &length);
6834 if (data) {
6835 int bufsize = 0;
6836 c->v.v2.locwindow -= length;
0e443c99 6837 c->v.v2.remlocwin -= length;
51df0ab5 6838 switch (c->type) {
6839 case CHAN_MAINSESSION:
6840 bufsize =
6841 from_backend(ssh->frontend, pktin->type ==
6842 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6843 data, length);
6844 break;
6845 case CHAN_X11:
6846 bufsize = x11_send(c->u.x11.s, data, length);
6847 break;
6848 case CHAN_SOCKDATA:
6849 bufsize = pfd_send(c->u.pfd.s, data, length);
6850 break;
6851 case CHAN_AGENT:
6852 while (length > 0) {
6853 if (c->u.a.lensofar < 4) {
62ddb51e 6854 unsigned int l = min(4 - c->u.a.lensofar,
6855 (unsigned)length);
51df0ab5 6856 memcpy(c->u.a.msglen + c->u.a.lensofar,
6857 data, l);
6858 data += l;
6859 length -= l;
6860 c->u.a.lensofar += l;
6861 }
6862 if (c->u.a.lensofar == 4) {
6863 c->u.a.totallen =
6864 4 + GET_32BIT(c->u.a.msglen);
6865 c->u.a.message = snewn(c->u.a.totallen,
6866 unsigned char);
6867 memcpy(c->u.a.message, c->u.a.msglen, 4);
6868 }
6869 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6870 unsigned int l =
51df0ab5 6871 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6872 (unsigned)length);
51df0ab5 6873 memcpy(c->u.a.message + c->u.a.lensofar,
6874 data, l);
6875 data += l;
6876 length -= l;
6877 c->u.a.lensofar += l;
6878 }
6879 if (c->u.a.lensofar == c->u.a.totallen) {
6880 void *reply;
6881 int replylen;
be3f980d 6882 c->u.a.outstanding_requests++;
51df0ab5 6883 if (agent_query(c->u.a.message,
6884 c->u.a.totallen,
6885 &reply, &replylen,
6886 ssh_agentf_callback, c))
6887 ssh_agentf_callback(c, reply, replylen);
6888 sfree(c->u.a.message);
bc06669b 6889 c->u.a.message = NULL;
51df0ab5 6890 c->u.a.lensofar = 0;
6891 }
6892 }
6893 bufsize = 0;
6894 break;
6895 }
6896 /*
0e443c99 6897 * If it looks like the remote end hit the end of its window,
6898 * and we didn't want it to do that, think about using a
6899 * larger window.
6900 */
6901 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6902 c->v.v2.locmaxwin < 0x40000000)
6903 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6904 /*
51df0ab5 6905 * If we are not buffering too much data,
6906 * enlarge the window again at the remote side.
467e064d 6907 * If we are buffering too much, we may still
6908 * need to adjust the window if the server's
6909 * sent excess data.
51df0ab5 6910 */
9b53e9b8 6911 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6912 c->v.v2.locmaxwin - bufsize : 0);
ff68564b 6913 /*
6914 * If we're either buffering way too much data, or if we're
6915 * buffering anything at all and we're in "simple" mode,
6916 * throttle the whole channel.
6917 */
6918 if ((bufsize > c->v.v2.locmaxwin ||
4a693cfc 6919 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
ff68564b 6920 !c->throttling_conn) {
6921 c->throttling_conn = 1;
6922 ssh_throttle_conn(ssh, +1);
6923 }
51df0ab5 6924 }
6925}
6926
bc06669b 6927static void ssh_channel_destroy(struct ssh_channel *c)
51df0ab5 6928{
bc06669b 6929 Ssh ssh = c->ssh;
51df0ab5 6930
bc06669b 6931 switch (c->type) {
6932 case CHAN_MAINSESSION:
6933 ssh->mainchan = NULL;
6934 update_specials_menu(ssh->frontend);
6935 break;
6936 case CHAN_X11:
6937 if (c->u.x11.s != NULL)
6938 x11_close(c->u.x11.s);
6939 logevent("Forwarded X11 connection terminated");
6940 break;
6941 case CHAN_AGENT:
6942 sfree(c->u.a.message);
6943 break;
6944 case CHAN_SOCKDATA:
6945 if (c->u.pfd.s != NULL)
6946 pfd_close(c->u.pfd.s);
6947 logevent("Forwarded port closed");
6948 break;
6949 }
6950
6951 del234(ssh->channels, c);
3620f307 6952 if (ssh->version == 2) {
bc06669b 6953 bufchain_clear(&c->v.v2.outbuffer);
3620f307 6954 assert(c->v.v2.chanreq_head == NULL);
6955 }
bc06669b 6956 sfree(c);
6957
6958 /*
6959 * See if that was the last channel left open.
6960 * (This is only our termination condition if we're
6961 * not running in -N mode.)
6962 */
6963 if (ssh->version == 2 &&
6964 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
6965 count234(ssh->channels) == 0) {
6966 /*
6967 * We used to send SSH_MSG_DISCONNECT here,
6968 * because I'd believed that _every_ conforming
6969 * SSH-2 connection had to end with a disconnect
6970 * being sent by at least one side; apparently
6971 * I was wrong and it's perfectly OK to
6972 * unceremoniously slam the connection shut
6973 * when you're done, and indeed OpenSSH feels
6974 * this is more polite than sending a
6975 * DISCONNECT. So now we don't.
6976 */
6977 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6978 }
6979}
6980
6981static void ssh2_channel_check_close(struct ssh_channel *c)
6982{
6983 Ssh ssh = c->ssh;
6984 struct Packet *pktout;
6985
04120005 6986 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
6987 c->type == CHAN_ZOMBIE) &&
6988 !c->v.v2.chanreq_head &&
6989 !(c->closes & CLOSES_SENT_CLOSE)) {
bc06669b 6990 /*
04120005 6991 * We have both sent and received EOF (or the channel is a
6992 * zombie), and we have no outstanding channel requests, which
6993 * means the channel is in final wind-up. But we haven't sent
6994 * CLOSE, so let's do so now.
bc06669b 6995 */
6996 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6997 ssh2_pkt_adduint32(pktout, c->remoteid);
6998 ssh2_pkt_send(ssh, pktout);
04120005 6999 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
bc06669b 7000 }
7001
7002 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
3620f307 7003 assert(c->v.v2.chanreq_head == NULL);
bc06669b 7004 /*
7005 * We have both sent and received CLOSE, which means we're
7006 * completely done with the channel.
7007 */
7008 ssh_channel_destroy(c);
7009 }
7010}
7011
7012static void ssh2_channel_got_eof(struct ssh_channel *c)
7013{
7014 if (c->closes & CLOSES_RCVD_EOF)
7015 return; /* already seen EOF */
7016 c->closes |= CLOSES_RCVD_EOF;
51df0ab5 7017
7018 if (c->type == CHAN_X11) {
bc06669b 7019 x11_send_eof(c->u.x11.s);
51df0ab5 7020 } else if (c->type == CHAN_AGENT) {
be3f980d 7021 if (c->u.a.outstanding_requests == 0) {
7022 /* Manufacture an outgoing EOF in response to the incoming one. */
7023 sshfwd_write_eof(c);
7024 }
51df0ab5 7025 } else if (c->type == CHAN_SOCKDATA) {
bc06669b 7026 pfd_send_eof(c->u.pfd.s);
7027 } else if (c->type == CHAN_MAINSESSION) {
7028 Ssh ssh = c->ssh;
7029
4a202fc6 7030 if (!ssh->sent_console_eof &&
7031 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
bc06669b 7032 /*
4a202fc6 7033 * Either from_backend_eof told us that the front end
7034 * wants us to close the outgoing side of the connection
7035 * as soon as we see EOF from the far end, or else we've
7036 * unilaterally decided to do that because we've allocated
7037 * a remote pty and hence EOF isn't a particularly
7038 * meaningful concept.
bc06669b 7039 */
7040 sshfwd_write_eof(c);
7041 }
7042 ssh->sent_console_eof = TRUE;
51df0ab5 7043 }
bc06669b 7044
7045 ssh2_channel_check_close(c);
7046}
7047
7048static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7049{
7050 struct ssh_channel *c;
7051
7052 c = ssh2_channel_msg(ssh, pktin);
7053 if (!c)
7054 return;
7055 ssh2_channel_got_eof(c);
51df0ab5 7056}
7057
7058static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7059{
51df0ab5 7060 struct ssh_channel *c;
51df0ab5 7061
e223b7c7 7062 c = ssh2_channel_msg(ssh, pktin);
7063 if (!c)
51df0ab5 7064 return;
51df0ab5 7065
7066 /*
bc06669b 7067 * When we receive CLOSE on a channel, we assume it comes with an
7068 * implied EOF if we haven't seen EOF yet.
51df0ab5 7069 */
bc06669b 7070 ssh2_channel_got_eof(c);
7071
7072 /*
3effbcf2 7073 * And we also send an outgoing EOF, if we haven't already, on the
7074 * assumption that CLOSE is a pretty forceful announcement that
7075 * the remote side is doing away with the entire channel. (If it
7076 * had wanted to send us EOF and continue receiving data from us,
7077 * it would have just sent CHANNEL_EOF.)
3effbcf2 7078 */
a699eb41 7079 if (!(c->closes & CLOSES_SENT_EOF)) {
7080 /*
7081 * Make sure we don't read any more from whatever our local
7082 * data source is for this channel.
7083 */
7084 switch (c->type) {
7085 case CHAN_MAINSESSION:
7086 ssh->send_ok = 0; /* stop trying to read from stdin */
7087 break;
7088 case CHAN_X11:
7089 x11_override_throttle(c->u.x11.s, 1);
7090 break;
7091 case CHAN_SOCKDATA:
7092 pfd_override_throttle(c->u.pfd.s, 1);
7093 break;
7094 }
7095
7096 /*
df988802 7097 * Abandon any buffered data we still wanted to send to this
7098 * channel. Receiving a CHANNEL_CLOSE is an indication that
7099 * the server really wants to get on and _destroy_ this
7100 * channel, and it isn't going to send us any further
7101 * WINDOW_ADJUSTs to permit us to send pending stuff.
7102 */
7103 bufchain_clear(&c->v.v2.outbuffer);
7104
7105 /*
a699eb41 7106 * Send outgoing EOF.
7107 */
7539afa2 7108 sshfwd_write_eof(c);
3effbcf2 7109 }
7110
7111 /*
bc06669b 7112 * Now process the actual close.
7113 */
7114 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7115 c->closes |= CLOSES_RCVD_CLOSE;
7116 ssh2_channel_check_close(c);
51df0ab5 7117 }
7118}
7119
7120static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7121{
51df0ab5 7122 struct ssh_channel *c;
51df0ab5 7123
e223b7c7 7124 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7125 if (!c)
e223b7c7 7126 return;
51df0ab5 7127 if (c->type != CHAN_SOCKDATA_DORMANT)
7128 return; /* dunno why they're confirming this */
7129 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7130 c->halfopen = FALSE;
51df0ab5 7131 c->type = CHAN_SOCKDATA;
7132 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7133 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7134 if (c->u.pfd.s)
7135 pfd_confirm(c->u.pfd.s);
bc06669b 7136 if (c->pending_eof)
7137 ssh_channel_try_eof(c);
51df0ab5 7138}
7139
7140static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7141{
7142 static const char *const reasons[] = {
7143 "<unknown reason code>",
7144 "Administratively prohibited",
7145 "Connect failed",
7146 "Unknown channel type",
7147 "Resource shortage",
7148 };
51df0ab5 7149 unsigned reason_code;
7150 char *reason_string;
7151 int reason_length;
51df0ab5 7152 struct ssh_channel *c;
e223b7c7 7153 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7154 if (!c)
e223b7c7 7155 return;
51df0ab5 7156 if (c->type != CHAN_SOCKDATA_DORMANT)
7157 return; /* dunno why they're failing this */
7158
7159 reason_code = ssh_pkt_getuint32(pktin);
7160 if (reason_code >= lenof(reasons))
7161 reason_code = 0; /* ensure reasons[reason_code] in range */
7162 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 7163 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7164 reasons[reason_code], reason_length, reason_string);
51df0ab5 7165
7166 pfd_close(c->u.pfd.s);
7167
7168 del234(ssh->channels, c);
7169 sfree(c);
7170}
7171
7172static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7173{
51df0ab5 7174 char *type;
7175 int typelen, want_reply;
7176 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7177 struct ssh_channel *c;
7178 struct Packet *pktout;
7179
e223b7c7 7180 c = ssh2_channel_msg(ssh, pktin);
7181 if (!c)
7182 return;
51df0ab5 7183 ssh_pkt_getstring(pktin, &type, &typelen);
7184 want_reply = ssh2_pkt_getbool(pktin);
7185
7186 /*
51df0ab5 7187 * Having got the channel number, we now look at
7188 * the request type string to see if it's something
7189 * we recognise.
7190 */
7191 if (c == ssh->mainchan) {
7192 /*
7193 * We recognise "exit-status" and "exit-signal" on
7194 * the primary channel.
7195 */
7196 if (typelen == 11 &&
7197 !memcmp(type, "exit-status", 11)) {
7198
7199 ssh->exitcode = ssh_pkt_getuint32(pktin);
7200 logeventf(ssh, "Server sent command exit status %d",
7201 ssh->exitcode);
7202 reply = SSH2_MSG_CHANNEL_SUCCESS;
7203
7204 } else if (typelen == 11 &&
7205 !memcmp(type, "exit-signal", 11)) {
7206
7207 int is_plausible = TRUE, is_int = FALSE;
7208 char *fmt_sig = "", *fmt_msg = "";
7209 char *msg;
7210 int msglen = 0, core = FALSE;
7211 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7212 * provide an `int' for the signal, despite its
bccbeb71 7213 * having been a `string' in the drafts of RFC 4254 since at
51df0ab5 7214 * least 2001. (Fixed in session.c 1.147.) Try to
7215 * infer which we can safely parse it as. */
7216 {
7217 unsigned char *p = pktin->body +
7218 pktin->savedpos;
7219 long len = pktin->length - pktin->savedpos;
7220 unsigned long num = GET_32BIT(p); /* what is it? */
7221 /* If it's 0, it hardly matters; assume string */
7222 if (num == 0) {
7223 is_int = FALSE;
7224 } else {
7225 int maybe_int = FALSE, maybe_str = FALSE;
b1650067 7226#define CHECK_HYPOTHESIS(offset, result) \
7227 do \
7228 { \
7229 int q = toint(offset); \
7230 if (q >= 0 && q+4 <= len) { \
7231 q = toint(q + 4 + GET_32BIT(p+q)); \
7232 if (q >= 0 && q+4 <= len && \
7233 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7234 q == len) \
7235 result = TRUE; \
7236 } \
7237 } while(0)
51df0ab5 7238 CHECK_HYPOTHESIS(4+1, maybe_int);
7239 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7240#undef CHECK_HYPOTHESIS
7241 if (maybe_int && !maybe_str)
7242 is_int = TRUE;
7243 else if (!maybe_int && maybe_str)
7244 is_int = FALSE;
7245 else
7246 /* Crikey. Either or neither. Panic. */
7247 is_plausible = FALSE;
7248 }
7249 }
d051d1b4 7250 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 7251 if (is_plausible) {
7252 if (is_int) {
7253 /* Old non-standard OpenSSH. */
7254 int signum = ssh_pkt_getuint32(pktin);
7255 fmt_sig = dupprintf(" %d", signum);
d051d1b4 7256 ssh->exitcode = 128 + signum;
51df0ab5 7257 } else {
bccbeb71 7258 /* As per RFC 4254. */
51df0ab5 7259 char *sig;
7260 int siglen;
7261 ssh_pkt_getstring(pktin, &sig, &siglen);
7262 /* Signal name isn't supposed to be blank, but
7263 * let's cope gracefully if it is. */
7264 if (siglen) {
7265 fmt_sig = dupprintf(" \"%.*s\"",
7266 siglen, sig);
7267 }
d051d1b4 7268
7269 /*
7270 * Really hideous method of translating the
7271 * signal description back into a locally
7272 * meaningful number.
7273 */
7274
7275 if (0)
7276 ;
b707973a 7277#define TRANSLATE_SIGNAL(s) \
7278 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7279 ssh->exitcode = 128 + SIG ## s
d051d1b4 7280#ifdef SIGABRT
b707973a 7281 TRANSLATE_SIGNAL(ABRT);
d051d1b4 7282#endif
7283#ifdef SIGALRM
b707973a 7284 TRANSLATE_SIGNAL(ALRM);
d051d1b4 7285#endif
7286#ifdef SIGFPE
b707973a 7287 TRANSLATE_SIGNAL(FPE);
d051d1b4 7288#endif
7289#ifdef SIGHUP
b707973a 7290 TRANSLATE_SIGNAL(HUP);
d051d1b4 7291#endif
7292#ifdef SIGILL
b707973a 7293 TRANSLATE_SIGNAL(ILL);
d051d1b4 7294#endif
7295#ifdef SIGINT
b707973a 7296 TRANSLATE_SIGNAL(INT);
d051d1b4 7297#endif
7298#ifdef SIGKILL
b707973a 7299 TRANSLATE_SIGNAL(KILL);
d051d1b4 7300#endif
7301#ifdef SIGPIPE
b707973a 7302 TRANSLATE_SIGNAL(PIPE);
d051d1b4 7303#endif
7304#ifdef SIGQUIT
b707973a 7305 TRANSLATE_SIGNAL(QUIT);
d051d1b4 7306#endif
7307#ifdef SIGSEGV
b707973a 7308 TRANSLATE_SIGNAL(SEGV);
d051d1b4 7309#endif
7310#ifdef SIGTERM
b707973a 7311 TRANSLATE_SIGNAL(TERM);
d051d1b4 7312#endif
7313#ifdef SIGUSR1
b707973a 7314 TRANSLATE_SIGNAL(USR1);
d051d1b4 7315#endif
7316#ifdef SIGUSR2
b707973a 7317 TRANSLATE_SIGNAL(USR2);
d051d1b4 7318#endif
b707973a 7319#undef TRANSLATE_SIGNAL
d051d1b4 7320 else
7321 ssh->exitcode = 128;
51df0ab5 7322 }
7323 core = ssh2_pkt_getbool(pktin);
7324 ssh_pkt_getstring(pktin, &msg, &msglen);
7325 if (msglen) {
7326 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7327 }
7328 /* ignore lang tag */
7329 } /* else don't attempt to parse */
7330 logeventf(ssh, "Server exited on signal%s%s%s",
7331 fmt_sig, core ? " (core dumped)" : "",
7332 fmt_msg);
7333 if (*fmt_sig) sfree(fmt_sig);
7334 if (*fmt_msg) sfree(fmt_msg);
7335 reply = SSH2_MSG_CHANNEL_SUCCESS;
7336
7337 }
7338 } else {
7339 /*
7340 * This is a channel request we don't know
7341 * about, so we now either ignore the request
7342 * or respond with CHANNEL_FAILURE, depending
7343 * on want_reply.
7344 */
7345 reply = SSH2_MSG_CHANNEL_FAILURE;
7346 }
7347 if (want_reply) {
7348 pktout = ssh2_pkt_init(reply);
7349 ssh2_pkt_adduint32(pktout, c->remoteid);
7350 ssh2_pkt_send(ssh, pktout);
7351 }
7352}
7353
7354static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7355{
7356 char *type;
7357 int typelen, want_reply;
7358 struct Packet *pktout;
7359
7360 ssh_pkt_getstring(pktin, &type, &typelen);
7361 want_reply = ssh2_pkt_getbool(pktin);
7362
7363 /*
7364 * We currently don't support any global requests
7365 * at all, so we either ignore the request or
7366 * respond with REQUEST_FAILURE, depending on
7367 * want_reply.
7368 */
7369 if (want_reply) {
7370 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7371 ssh2_pkt_send(ssh, pktout);
7372 }
7373}
7374
7375static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7376{
7377 char *type;
7378 int typelen;
7379 char *peeraddr;
7380 int peeraddrlen;
7381 int peerport;
7382 char *error = NULL;
7383 struct ssh_channel *c;
7384 unsigned remid, winsize, pktsize;
7385 struct Packet *pktout;
7386
7387 ssh_pkt_getstring(pktin, &type, &typelen);
7388 c = snew(struct ssh_channel);
7389 c->ssh = ssh;
7390
7391 remid = ssh_pkt_getuint32(pktin);
7392 winsize = ssh_pkt_getuint32(pktin);
7393 pktsize = ssh_pkt_getuint32(pktin);
7394
7395 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7396 char *addrstr;
5907ebda 7397 const char *x11err;
51df0ab5 7398
7399 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7400 addrstr = snewn(peeraddrlen+1, char);
7401 memcpy(addrstr, peeraddr, peeraddrlen);
7402 addrstr[peeraddrlen] = '\0';
7403 peerport = ssh_pkt_getuint32(pktin);
7404
7405 logeventf(ssh, "Received X11 connect request from %s:%d",
7406 addrstr, peerport);
7407
7408 if (!ssh->X11_fwd_enabled)
7409 error = "X11 forwarding is not enabled";
5907ebda 7410 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 7411 addrstr, peerport, ssh->conf)) != NULL) {
5907ebda 7412 logeventf(ssh, "Local X11 connection failed: %s", x11err);
51df0ab5 7413 error = "Unable to open an X11 connection";
7414 } else {
7415 logevent("Opening X11 forward connection succeeded");
7416 c->type = CHAN_X11;
7417 }
7418
7419 sfree(addrstr);
7420 } else if (typelen == 15 &&
7421 !memcmp(type, "forwarded-tcpip", 15)) {
7422 struct ssh_rportfwd pf, *realpf;
7423 char *dummy;
7424 int dummylen;
7425 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7426 pf.sport = ssh_pkt_getuint32(pktin);
7427 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7428 peerport = ssh_pkt_getuint32(pktin);
7429 realpf = find234(ssh->rportfwds, &pf, NULL);
7430 logeventf(ssh, "Received remote port %d open request "
7431 "from %s:%d", pf.sport, peeraddr, peerport);
7432 if (realpf == NULL) {
7433 error = "Remote port is not recognised";
7434 } else {
7435 const char *e = pfd_newconnect(&c->u.pfd.s,
7436 realpf->dhost,
7437 realpf->dport, c,
4a693cfc 7438 ssh->conf,
05581745 7439 realpf->pfrec->addressfamily);
51df0ab5 7440 logeventf(ssh, "Attempting to forward remote port to "
7441 "%s:%d", realpf->dhost, realpf->dport);
7442 if (e != NULL) {
7443 logeventf(ssh, "Port open failed: %s", e);
7444 error = "Port open failed";
7445 } else {
7446 logevent("Forwarded port opened successfully");
7447 c->type = CHAN_SOCKDATA;
7448 }
7449 }
7450 } else if (typelen == 22 &&
c49cf994 7451 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 7452 if (!ssh->agentfwd_enabled)
7453 error = "Agent forwarding is not enabled";
7454 else {
7455 c->type = CHAN_AGENT; /* identify channel type */
7456 c->u.a.lensofar = 0;
be3f980d 7457 c->u.a.outstanding_requests = 0;
51df0ab5 7458 }
7459 } else {
7460 error = "Unsupported channel type requested";
7461 }
7462
7463 c->remoteid = remid;
64d6ff88 7464 c->halfopen = FALSE;
51df0ab5 7465 if (error) {
7466 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7467 ssh2_pkt_adduint32(pktout, c->remoteid);
7468 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7469 ssh2_pkt_addstring(pktout, error);
7470 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7471 ssh2_pkt_send(ssh, pktout);
7472 logeventf(ssh, "Rejected channel open: %s", error);
7473 sfree(c);
7474 } else {
94bdfe40 7475 ssh2_channel_init(c);
51df0ab5 7476 c->v.v2.remwindow = winsize;
7477 c->v.v2.remmaxpkt = pktsize;
51df0ab5 7478 add234(ssh->channels, c);
7479 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7480 ssh2_pkt_adduint32(pktout, c->remoteid);
7481 ssh2_pkt_adduint32(pktout, c->localid);
7482 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 7483 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 7484 ssh2_pkt_send(ssh, pktout);
7485 }
7486}
7487
6bbce591 7488/*
adb6167a 7489 * Buffer banner messages for later display at some convenient point,
7490 * if we're going to display them.
6bbce591 7491 */
7492static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7493{
7494 /* Arbitrary limit to prevent unbounded inflation of buffer */
4a693cfc 7495 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
adb6167a 7496 bufchain_size(&ssh->banner) <= 131072) {
6bbce591 7497 char *banner = NULL;
7498 int size = 0;
7499 ssh_pkt_getstring(pktin, &banner, &size);
7500 if (banner)
7501 bufchain_add(&ssh->banner, banner, size);
7502 }
7503}
7504
c6ccd5c2 7505/* Helper function to deal with sending tty modes for "pty-req" */
7506static void ssh2_send_ttymode(void *data, char *mode, char *val)
7507{
7508 struct Packet *pktout = (struct Packet *)data;
7509 int i = 0;
7510 unsigned int arg = 0;
7511 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7512 if (i == lenof(ssh_ttymodes)) return;
7513 switch (ssh_ttymodes[i].type) {
7514 case TTY_OP_CHAR:
7515 arg = ssh_tty_parse_specchar(val);
7516 break;
7517 case TTY_OP_BOOL:
7518 arg = ssh_tty_parse_boolean(val);
7519 break;
7520 }
7521 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7522 ssh2_pkt_adduint32(pktout, arg);
7523}
7524
67a9ec92 7525static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7526 void *ctx)
ebbc254d 7527{
67a9ec92 7528 struct ssh2_setup_x11_state {
ebbc254d 7529 int crLine;
7530 };
7531 Ssh ssh = c->ssh;
7532 struct Packet *pktout;
67a9ec92 7533 crStateP(ssh2_setup_x11_state, ctx);
ebbc254d 7534
7535 crBeginState;
7536
67a9ec92 7537 logevent("Requesting X11 forwarding");
7538 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7539 ssh2_setup_x11, s);
7540 ssh2_pkt_addbool(pktout, 0); /* many connections */
7541 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
ebbc254d 7542 /*
67a9ec92 7543 * Note that while we blank the X authentication data here, we don't
7544 * take any special action to blank the start of an X11 channel,
7545 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7546 * without having session blanking enabled is likely to leak your
7547 * cookie into the log.
ebbc254d 7548 */
67a9ec92 7549 dont_log_password(ssh, pktout, PKTLOG_BLANK);
7550 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7551 end_log_omission(ssh, pktout);
7552 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7553 ssh2_pkt_send(ssh, pktout);
ebbc254d 7554
1bc8ef67 7555 /* Wait to be called back with either a response packet, or NULL
7556 * meaning clean up and free our data */
7557 crReturnV;
ebbc254d 7558
67a9ec92 7559 if (pktin) {
7560 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7561 logevent("X11 forwarding enabled");
7562 ssh->X11_fwd_enabled = TRUE;
7563 } else
7564 logevent("X11 forwarding refused");
ebbc254d 7565 }
67a9ec92 7566
0d201bfb 7567 crFinishFreeV;
ebbc254d 7568}
7569
67a9ec92 7570static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
ebbc254d 7571 void *ctx)
7572{
67a9ec92 7573 struct ssh2_setup_agent_state {
ebbc254d 7574 int crLine;
7575 };
7576 Ssh ssh = c->ssh;
7577 struct Packet *pktout;
67a9ec92 7578 crStateP(ssh2_setup_agent_state, ctx);
ebbc254d 7579
7580 crBeginState;
7581
67a9ec92 7582 logevent("Requesting OpenSSH-style agent forwarding");
7583 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7584 ssh2_setup_agent, s);
7585 ssh2_pkt_send(ssh, pktout);
ebbc254d 7586
1bc8ef67 7587 /* Wait to be called back with either a response packet, or NULL
7588 * meaning clean up and free our data */
7589 crReturnV;
ebbc254d 7590
67a9ec92 7591 if (pktin) {
7592 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7593 logevent("Agent forwarding enabled");
7594 ssh->agentfwd_enabled = TRUE;
7595 } else
7596 logevent("Agent forwarding refused");
ebbc254d 7597 }
67a9ec92 7598
0d201bfb 7599 crFinishFreeV;
ebbc254d 7600}
7601
67a9ec92 7602static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
ebbc254d 7603 void *ctx)
7604{
67a9ec92 7605 struct ssh2_setup_pty_state {
ebbc254d 7606 int crLine;
7607 };
7608 Ssh ssh = c->ssh;
7609 struct Packet *pktout;
67a9ec92 7610 crStateP(ssh2_setup_pty_state, ctx);
ebbc254d 7611
7612 crBeginState;
7613
67a9ec92 7614 /* Unpick the terminal-speed string. */
7615 /* XXX perhaps we should allow no speeds to be sent. */
7616 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7617 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7618 /* Build the pty request. */
7619 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7620 ssh2_setup_pty, s);
7621 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7622 ssh2_pkt_adduint32(pktout, ssh->term_width);
7623 ssh2_pkt_adduint32(pktout, ssh->term_height);
7624 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7625 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7626 ssh2_pkt_addstring_start(pktout);
7627 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7628 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7629 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7630 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7631 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7632 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7633 ssh2_pkt_send(ssh, pktout);
7634 ssh->state = SSH_STATE_INTERMED;
ebbc254d 7635
1bc8ef67 7636 /* Wait to be called back with either a response packet, or NULL
7637 * meaning clean up and free our data */
7638 crReturnV;
ebbc254d 7639
67a9ec92 7640 if (pktin) {
7641 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7642 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7643 ssh->ospeed, ssh->ispeed);
7644 ssh->got_pty = TRUE;
7645 } else {
7646 c_write_str(ssh, "Server refused to allocate pty\r\n");
7647 ssh->editing = ssh->echoing = 1;
7648 }
ebbc254d 7649 }
67a9ec92 7650
0d201bfb 7651 crFinishFreeV;
ebbc254d 7652}
7653
7654static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7655 void *ctx)
7656{
7657 struct ssh2_setup_env_state {
7658 int crLine;
7659 int num_env, env_left, env_ok;
7660 };
7661 Ssh ssh = c->ssh;
7662 struct Packet *pktout;
7663 crStateP(ssh2_setup_env_state, ctx);
7664
7665 crBeginState;
7666
7667 /*
7668 * Send environment variables.
7669 *
7670 * Simplest thing here is to send all the requests at once, and
7671 * then wait for a whole bunch of successes or failures.
7672 */
7673 s->num_env = 0;
67a9ec92 7674 {
ebbc254d 7675 char *key, *val;
7676
7677 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7678 val != NULL;
7679 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
134f5ece 7680 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
ebbc254d 7681 ssh2_pkt_addstring(pktout, key);
7682 ssh2_pkt_addstring(pktout, val);
7683 ssh2_pkt_send(ssh, pktout);
ebbc254d 7684
7685 s->num_env++;
7686 }
7687 if (s->num_env)
7688 logeventf(ssh, "Sent %d environment variables", s->num_env);
7689 }
7690
7691 if (s->num_env) {
7692 s->env_ok = 0;
7693 s->env_left = s->num_env;
7694
7695 while (s->env_left > 0) {
1bc8ef67 7696 /* Wait to be called back with either a response packet,
7697 * or NULL meaning clean up and free our data */
7698 crReturnV;
3620f307 7699 if (!pktin) goto out;
c330b1cc 7700 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
ebbc254d 7701 s->env_ok++;
ebbc254d 7702 s->env_left--;
7703 }
7704
7705 if (s->env_ok == s->num_env) {
7706 logevent("All environment variables successfully set");
7707 } else if (s->env_ok == 0) {
7708 logevent("All environment variables refused");
7709 c_write_str(ssh, "Server refused to set environment variables\r\n");
7710 } else {
7711 logeventf(ssh, "%d environment variables refused",
7712 s->num_env - s->env_ok);
7713 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7714 }
7715 }
5ca12719 7716 out:;
0d201bfb 7717 crFinishFreeV;
ebbc254d 7718}
7719
783415f8 7720/*
2e85c969 7721 * Handle the SSH-2 userauth and connection layers.
7cca0d81 7722 */
bc074147 7723static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7724{
7725 do_ssh2_authconn(ssh, NULL, 0, pktin);
7726}
7727
ebbc254d 7728static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7729 void *ctx)
7730{
7731 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7732}
7733
ff3187f6 7734static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7735 struct Packet *pktin)
7cca0d81 7736{
51470298 7737 struct do_ssh2_authconn_state {
30919997 7738 int crLine;
51470298 7739 enum {
51470298 7740 AUTH_TYPE_NONE,
7741 AUTH_TYPE_PUBLICKEY,
7742 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7743 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7744 AUTH_TYPE_PASSWORD,
8221906d 7745 AUTH_TYPE_GSSAPI, /* always QUIET */
51470298 7746 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7747 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7748 } type;
a1a1fae4 7749 int done_service_req;
51470298 7750 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 7751 int tried_pubkey_config, done_agent;
bf84a03a 7752#ifndef NO_GSSAPI
42af6a67 7753 int can_gssapi;
7754 int tried_gssapi;
bf84a03a 7755#endif
edd0cb8a 7756 int kbd_inter_refused;
ab18ccff 7757 int we_are_in, userauth_success;
edd0cb8a 7758 prompts_t *cur_prompt;
7759 int num_prompts;
4a693cfc 7760 char *username;
e955d348 7761 char *password;
51470298 7762 int got_username;
51470298 7763 void *publickey_blob;
7764 int publickey_bloblen;
edd0cb8a 7765 int publickey_encrypted;
7766 char *publickey_algorithm;
7767 char *publickey_comment;
94cd7c3a 7768 unsigned char agent_request[5], *agent_response, *agentp;
7769 int agent_responselen;
7770 unsigned char *pkblob_in_agent;
51470298 7771 int keyi, nkeys;
51470298 7772 char *pkblob, *alg, *commentp;
7773 int pklen, alglen, commentlen;
7774 int siglen, retlen, len;
7775 char *q, *agentreq, *ret;
7776 int try_send;
ff3187f6 7777 struct Packet *pktout;
4a693cfc 7778 Filename *keyfile;
bf84a03a 7779#ifndef NO_GSSAPI
b3d375b2 7780 struct ssh_gss_library *gsslib;
42af6a67 7781 Ssh_gss_ctx gss_ctx;
7782 Ssh_gss_buf gss_buf;
7783 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7784 Ssh_gss_name gss_srv_name;
7785 Ssh_gss_stat gss_stat;
bf84a03a 7786#endif
51470298 7787 };
7788 crState(do_ssh2_authconn_state);
7789
30919997 7790 crBeginState;
e5574168 7791
bc074147 7792 /* Register as a handler for all the messages this coroutine handles. */
7793 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7794 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7795 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7796 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7797 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7798 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7799 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7800 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7801 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7802 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7803 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7804 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7805 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7806 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7807 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7808 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7809 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7810 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7811 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7812 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
bc074147 7813
a1a1fae4 7814 s->done_service_req = FALSE;
ab18ccff 7815 s->we_are_in = s->userauth_success = FALSE;
bf84a03a 7816#ifndef NO_GSSAPI
42af6a67 7817 s->tried_gssapi = FALSE;
bf84a03a 7818#endif
42af6a67 7819
4a693cfc 7820 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
a1a1fae4 7821 /*
7822 * Request userauth protocol, and await a response to it.
7823 */
7824 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7825 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7826 ssh2_pkt_send(ssh, s->pktout);
7827 crWaitUntilV(pktin);
7828 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7829 s->done_service_req = TRUE;
7830 }
7831 if (!s->done_service_req) {
7832 /*
7833 * Request connection protocol directly, without authentication.
7834 */
7835 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7836 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7837 ssh2_pkt_send(ssh, s->pktout);
7838 crWaitUntilV(pktin);
7839 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7840 s->we_are_in = TRUE; /* no auth required */
7841 } else {
7842 bombout(("Server refused service request"));
7843 crStopV;
7844 }
8d5de777 7845 }
7cca0d81 7846
94cd7c3a 7847 /* Arrange to be able to deal with any BANNERs that come in.
7848 * (We do this now as packets may come in during the next bit.) */
7849 bufchain_init(&ssh->banner);
7850 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7851 ssh2_msg_userauth_banner;
7852
7cca0d81 7853 /*
edd0cb8a 7854 * Misc one-time setup for authentication.
7855 */
7856 s->publickey_blob = NULL;
7857 if (!s->we_are_in) {
7858
7859 /*
7860 * Load the public half of any configured public key file
7861 * for later use.
7862 */
4a693cfc 7863 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 7864 if (!filename_is_null(s->keyfile)) {
edd0cb8a 7865 int keytype;
7866 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 7867 filename_to_str(s->keyfile));
7868 keytype = key_type(s->keyfile);
edd0cb8a 7869 if (keytype == SSH_KEYTYPE_SSH2) {
7870 const char *error;
7871 s->publickey_blob =
4a693cfc 7872 ssh2_userkey_loadpub(s->keyfile,
edd0cb8a 7873 &s->publickey_algorithm,
7874 &s->publickey_bloblen,
7875 &s->publickey_comment, &error);
7876 if (s->publickey_blob) {
7877 s->publickey_encrypted =
4a693cfc 7878 ssh2_userkey_encrypted(s->keyfile, NULL);
edd0cb8a 7879 } else {
7880 char *msgbuf;
7881 logeventf(ssh, "Unable to load private key (%s)",
7882 error);
7883 msgbuf = dupprintf("Unable to load private key file "
7884 "\"%.150s\" (%s)\r\n",
4a693cfc 7885 filename_to_str(s->keyfile),
edd0cb8a 7886 error);
7887 c_write_str(ssh, msgbuf);
7888 sfree(msgbuf);
7889 }
7890 } else {
7891 char *msgbuf;
7892 logeventf(ssh, "Unable to use this key file (%s)",
7893 key_type_to_str(keytype));
7894 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7895 " (%s)\r\n",
4a693cfc 7896 filename_to_str(s->keyfile),
edd0cb8a 7897 key_type_to_str(keytype));
7898 c_write_str(ssh, msgbuf);
7899 sfree(msgbuf);
7900 s->publickey_blob = NULL;
7901 }
7902 }
7903
94cd7c3a 7904 /*
7905 * Find out about any keys Pageant has (but if there's a
7906 * public key configured, filter out all others).
7907 */
7908 s->nkeys = 0;
7909 s->agent_response = NULL;
7910 s->pkblob_in_agent = NULL;
4a693cfc 7911 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
94cd7c3a 7912
7913 void *r;
7914
7915 logevent("Pageant is running. Requesting keys.");
7916
7917 /* Request the keys held by the agent. */
7918 PUT_32BIT(s->agent_request, 1);
7919 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7920 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7921 ssh_agent_callback, ssh)) {
7922 do {
7923 crReturnV;
7924 if (pktin) {
7925 bombout(("Unexpected data from server while"
7926 " waiting for agent response"));
7927 crStopV;
7928 }
7929 } while (pktin || inlen > 0);
7930 r = ssh->agent_response;
7931 s->agent_responselen = ssh->agent_response_len;
7932 }
7933 s->agent_response = (unsigned char *) r;
7934 if (s->agent_response && s->agent_responselen >= 5 &&
7935 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7936 int keyi;
7937 unsigned char *p;
7938 p = s->agent_response + 5;
b1650067 7939 s->nkeys = toint(GET_32BIT(p));
7940
7941 /*
7942 * Vet the Pageant response to ensure that the key
7943 * count and blob lengths make sense.
7944 */
7945 if (s->nkeys < 0) {
7946 logeventf(ssh, "Pageant response contained a negative"
7947 " key count %d", s->nkeys);
7948 s->nkeys = 0;
7949 goto done_agent_query;
7950 } else {
7951 unsigned char *q = p + 4;
7952 int lenleft = s->agent_responselen - 5 - 4;
7953
7954 for (keyi = 0; keyi < s->nkeys; keyi++) {
7955 int bloblen, commentlen;
7956 if (lenleft < 4) {
7957 logeventf(ssh, "Pageant response was truncated");
7958 s->nkeys = 0;
7959 goto done_agent_query;
7960 }
7961 bloblen = toint(GET_32BIT(q));
7962 if (bloblen < 0 || bloblen > lenleft) {
7963 logeventf(ssh, "Pageant response was truncated");
7964 s->nkeys = 0;
7965 goto done_agent_query;
7966 }
7967 lenleft -= 4 + bloblen;
7968 q += 4 + bloblen;
7969 commentlen = toint(GET_32BIT(q));
7970 if (commentlen < 0 || commentlen > lenleft) {
7971 logeventf(ssh, "Pageant response was truncated");
7972 s->nkeys = 0;
7973 goto done_agent_query;
7974 }
7975 lenleft -= 4 + commentlen;
7976 q += 4 + commentlen;
7977 }
7978 }
7979
94cd7c3a 7980 p += 4;
7981 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7982 if (s->publickey_blob) {
7983 /* See if configured key is in agent. */
7984 for (keyi = 0; keyi < s->nkeys; keyi++) {
b1650067 7985 s->pklen = toint(GET_32BIT(p));
94cd7c3a 7986 if (s->pklen == s->publickey_bloblen &&
7987 !memcmp(p+4, s->publickey_blob,
7988 s->publickey_bloblen)) {
7989 logeventf(ssh, "Pageant key #%d matches "
7990 "configured key file", keyi);
7991 s->keyi = keyi;
7992 s->pkblob_in_agent = p;
7993 break;
7994 }
7995 p += 4 + s->pklen;
b1650067 7996 p += toint(GET_32BIT(p)) + 4; /* comment */
94cd7c3a 7997 }
7998 if (!s->pkblob_in_agent) {
7999 logevent("Configured key file not in Pageant");
8000 s->nkeys = 0;
8001 }
8002 }
5ff99b8e 8003 } else {
8004 logevent("Failed to get reply from Pageant");
94cd7c3a 8005 }
b1650067 8006 done_agent_query:;
94cd7c3a 8007 }
8008
edd0cb8a 8009 }
8010
8011 /*
1408a877 8012 * We repeat this whole loop, including the username prompt,
8013 * until we manage a successful authentication. If the user
51470298 8014 * types the wrong _password_, they can be sent back to the
8015 * beginning to try another username, if this is configured on.
8016 * (If they specify a username in the config, they are never
8017 * asked, even if they do give a wrong password.)
1408a877 8018 *
8019 * I think this best serves the needs of
8020 *
8021 * - the people who have no configuration, no keys, and just
8022 * want to try repeated (username,password) pairs until they
8023 * type both correctly
8024 *
8025 * - people who have keys and configuration but occasionally
8026 * need to fall back to passwords
8027 *
8028 * - people with a key held in Pageant, who might not have
8029 * logged in to a particular machine before; so they want to
8030 * type a username, and then _either_ their key will be
8031 * accepted, _or_ they will type a password. If they mistype
8032 * the username they will want to be able to get back and
8033 * retype it!
7cca0d81 8034 */
51470298 8035 s->got_username = FALSE;
a1a1fae4 8036 while (!s->we_are_in) {
1408a877 8037 /*
8038 * Get a username.
8039 */
4a693cfc 8040 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
5bb641e1 8041 /*
8042 * We got a username last time round this loop, and
8043 * with change_username turned off we don't try to get
8044 * it again.
8045 */
4a693cfc 8046 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 8047 int ret; /* need not be kept over crReturn */
8048 s->cur_prompt = new_prompts(ssh->frontend);
8049 s->cur_prompt->to_server = TRUE;
8050 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 8051 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 8052 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8053 while (ret < 0) {
51470298 8054 ssh->send_ok = 1;
edd0cb8a 8055 crWaitUntilV(!pktin);
8056 ret = get_userpass_input(s->cur_prompt, in, inlen);
8057 ssh->send_ok = 0;
32874aea 8058 }
edd0cb8a 8059 if (!ret) {
8060 /*
8061 * get_userpass_input() failed to get a username.
8062 * Terminate.
8063 */
8064 free_prompts(s->cur_prompt);
8065 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8066 crStopV;
8067 }
4a693cfc 8068 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 8069 free_prompts(s->cur_prompt);
7cca0d81 8070 } else {
57356d63 8071 char *stuff;
65a22376 8072 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4a693cfc 8073 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
51470298 8074 c_write_str(ssh, stuff);
57356d63 8075 sfree(stuff);
7cca0d81 8076 }
8077 }
51470298 8078 s->got_username = TRUE;
7cca0d81 8079
65a22376 8080 /*
1408a877 8081 * Send an authentication request using method "none": (a)
8082 * just in case it succeeds, and (b) so that we know what
8083 * authentication methods we can usefully try next.
65a22376 8084 */
acab36bc 8085 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 8086
ff3187f6 8087 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8088 ssh2_pkt_addstring(s->pktout, ssh->username);
ff3187f6 8089 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8090 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8091 ssh2_pkt_send(ssh, s->pktout);
51470298 8092 s->type = AUTH_TYPE_NONE;
8093 s->gotit = FALSE;
8094 s->we_are_in = FALSE;
8095
8096 s->tried_pubkey_config = FALSE;
6ac3a551 8097 s->kbd_inter_refused = FALSE;
65a22376 8098
94cd7c3a 8099 /* Reset agent request state. */
8100 s->done_agent = FALSE;
8101 if (s->agent_response) {
8102 if (s->pkblob_in_agent) {
8103 s->agentp = s->pkblob_in_agent;
8104 } else {
8105 s->agentp = s->agent_response + 5 + 4;
8106 s->keyi = 0;
8107 }
8108 }
8109
1408a877 8110 while (1) {
854caca5 8111 char *methods = NULL;
8112 int methlen = 0;
8113
1408a877 8114 /*
8115 * Wait for the result of the last authentication request.
8116 */
51470298 8117 if (!s->gotit)
ff3187f6 8118 crWaitUntilV(pktin);
6bbce591 8119 /*
8120 * Now is a convenient point to spew any banner material
8121 * that we've accumulated. (This should ensure that when
8122 * we exit the auth loop, we haven't any left to deal
8123 * with.)
8124 */
8125 {
8126 int size = bufchain_size(&ssh->banner);
32874aea 8127 /*
8128 * Don't show the banner if we're operating in
8129 * non-verbose non-interactive mode. (It's probably
8130 * a script, which means nobody will read the
8131 * banner _anyway_, and moreover the printing of
8132 * the banner will screw up processing on the
8133 * output of (say) plink.)
8134 */
6bbce591 8135 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8136 char *banner = snewn(size, char);
8137 bufchain_fetch(&ssh->banner, banner, size);
8138 c_write_untrusted(ssh, banner, size);
8139 sfree(banner);
32874aea 8140 }
6bbce591 8141 bufchain_clear(&ssh->banner);
1408a877 8142 }
ff3187f6 8143 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 8144 logevent("Access granted");
ab18ccff 8145 s->we_are_in = s->userauth_success = TRUE;
1408a877 8146 break;
8147 }
65a22376 8148
42af6a67 8149 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
e955d348 8150 bombout(("Strange packet received during authentication: "
8151 "type %d", pktin->type));
7ffdbc1a 8152 crStopV;
65a22376 8153 }
8154
51470298 8155 s->gotit = FALSE;
65a22376 8156
1408a877 8157 /*
8158 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8159 * we can look at the string in it and know what we can
8160 * helpfully try next.
8161 */
ff3187f6 8162 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
ff3187f6 8163 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 8164 if (!ssh2_pkt_getbool(pktin)) {
1408a877 8165 /*
8166 * We have received an unequivocal Access
8167 * Denied. This can translate to a variety of
8221906d 8168 * messages, or no message at all.
8169 *
8170 * For forms of authentication which are attempted
8171 * implicitly, by which I mean without printing
8172 * anything in the window indicating that we're
8173 * trying them, we should never print 'Access
8174 * denied'.
8175 *
8176 * If we do print a message saying that we're
8177 * attempting some kind of authentication, it's OK
8178 * to print a followup message saying it failed -
8179 * but the message may sometimes be more specific
8180 * than simply 'Access denied'.
8181 *
1408a877 8182 * Additionally, if we'd just tried password
8183 * authentication, we should break out of this
8184 * whole loop so as to go back to the username
91f57d1f 8185 * prompt (iff we're configured to allow
8186 * username change attempts).
1408a877 8187 */
51470298 8188 if (s->type == AUTH_TYPE_NONE) {
1408a877 8189 /* do nothing */
51470298 8190 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8191 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8192 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8193 c_write_str(ssh, "Server refused our key\r\n");
8221906d 8194 logevent("Server refused our key");
8195 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8196 /* This _shouldn't_ happen except by a
8197 * protocol bug causing client and server to
8198 * disagree on what is a correct signature. */
8199 c_write_str(ssh, "Server refused public-key signature"
8200 " despite accepting key!\r\n");
8201 logevent("Server refused public-key signature"
8202 " despite accepting key!");
51470298 8203 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8221906d 8204 /* quiet, so no c_write */
8205 logevent("Server refused keyboard-interactive authentication");
8206 } else if (s->type==AUTH_TYPE_GSSAPI) {
8207 /* always quiet, so no c_write */
2af4fe8f 8208 /* also, the code down in the GSSAPI block has
8209 * already logged this in the Event Log */
8221906d 8210 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8211 logevent("Keyboard-interactive authentication failed");
8212 c_write_str(ssh, "Access denied\r\n");
8213 } else {
8214 assert(s->type == AUTH_TYPE_PASSWORD);
8215 logevent("Password authentication failed");
51470298 8216 c_write_str(ssh, "Access denied\r\n");
8221906d 8217
8218 if (conf_get_int(ssh->conf, CONF_change_username)) {
6c9dce7c 8219 /* XXX perhaps we should allow
8220 * keyboard-interactive to do this too? */
51470298 8221 s->we_are_in = FALSE;
1408a877 8222 break;
8223 }
8224 }
8225 } else {
51470298 8226 c_write_str(ssh, "Further authentication required\r\n");
1408a877 8227 logevent("Further authentication required");
8228 }
65a22376 8229
51470298 8230 s->can_pubkey =
32874aea 8231 in_commasep_string("publickey", methods, methlen);
51470298 8232 s->can_passwd =
32874aea 8233 in_commasep_string("password", methods, methlen);
4a693cfc 8234 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
761187b6 8235 in_commasep_string("keyboard-interactive", methods, methlen);
1e00c92b 8236#ifndef NO_GSSAPI
8237 if (!ssh->gsslibs)
4a693cfc 8238 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8239 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
b3d375b2 8240 in_commasep_string("gssapi-with-mic", methods, methlen) &&
1e00c92b 8241 ssh->gsslibs->nlibraries > 0;
42af6a67 8242#endif
1408a877 8243 }
65a22376 8244
acab36bc 8245 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 8246
94cd7c3a 8247 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 8248
1983e559 8249 /*
94cd7c3a 8250 * Attempt public-key authentication using a key from Pageant.
1983e559 8251 */
1983e559 8252
acab36bc 8253 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8254
94cd7c3a 8255 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8256
8257 /* Unpack key from agent response */
b1650067 8258 s->pklen = toint(GET_32BIT(s->agentp));
94cd7c3a 8259 s->agentp += 4;
8260 s->pkblob = (char *)s->agentp;
8261 s->agentp += s->pklen;
b1650067 8262 s->alglen = toint(GET_32BIT(s->pkblob));
94cd7c3a 8263 s->alg = s->pkblob + 4;
b1650067 8264 s->commentlen = toint(GET_32BIT(s->agentp));
94cd7c3a 8265 s->agentp += 4;
8266 s->commentp = (char *)s->agentp;
8267 s->agentp += s->commentlen;
8268 /* s->agentp now points at next key, if any */
8269
8270 /* See if server will accept it */
8271 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8272 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 8273 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8274 /* service requested */
8275 ssh2_pkt_addstring(s->pktout, "publickey");
8276 /* method */
8277 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8278 ssh2_pkt_addstring_start(s->pktout);
8279 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8280 ssh2_pkt_addstring_start(s->pktout);
8281 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8282 ssh2_pkt_send(ssh, s->pktout);
8283 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 8284
94cd7c3a 8285 crWaitUntilV(pktin);
8286 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 8287
94cd7c3a 8288 /* Offer of key refused. */
8289 s->gotit = TRUE;
1983e559 8290
94cd7c3a 8291 } else {
8292
8293 void *vret;
1983e559 8294
94cd7c3a 8295 if (flags & FLAG_VERBOSE) {
8296 c_write_str(ssh, "Authenticating with "
8297 "public key \"");
8298 c_write(ssh, s->commentp, s->commentlen);
8299 c_write_str(ssh, "\" from agent\r\n");
8300 }
1983e559 8301
94cd7c3a 8302 /*
8303 * Server is willing to accept the key.
8304 * Construct a SIGN_REQUEST.
8305 */
8306 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8307 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 8308 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8309 /* service requested */
8310 ssh2_pkt_addstring(s->pktout, "publickey");
8311 /* method */
8312 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8313 ssh2_pkt_addstring_start(s->pktout);
8314 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8315 ssh2_pkt_addstring_start(s->pktout);
8316 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8317
8318 /* Ask agent for signature. */
8319 s->siglen = s->pktout->length - 5 + 4 +
8320 ssh->v2_session_id_len;
8321 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8322 s->siglen -= 4;
8323 s->len = 1; /* message type */
8324 s->len += 4 + s->pklen; /* key blob */
8325 s->len += 4 + s->siglen; /* data to sign */
8326 s->len += 4; /* flags */
8327 s->agentreq = snewn(4 + s->len, char);
8328 PUT_32BIT(s->agentreq, s->len);
8329 s->q = s->agentreq + 4;
8330 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8331 PUT_32BIT(s->q, s->pklen);
8332 s->q += 4;
8333 memcpy(s->q, s->pkblob, s->pklen);
8334 s->q += s->pklen;
8335 PUT_32BIT(s->q, s->siglen);
8336 s->q += 4;
8337 /* Now the data to be signed... */
8338 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8339 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 8340 s->q += 4;
94cd7c3a 8341 }
8342 memcpy(s->q, ssh->v2_session_id,
8343 ssh->v2_session_id_len);
8344 s->q += ssh->v2_session_id_len;
8345 memcpy(s->q, s->pktout->data + 5,
8346 s->pktout->length - 5);
8347 s->q += s->pktout->length - 5;
8348 /* And finally the (zero) flags word. */
8349 PUT_32BIT(s->q, 0);
8350 if (!agent_query(s->agentreq, s->len + 4,
8351 &vret, &s->retlen,
8352 ssh_agent_callback, ssh)) {
8353 do {
8354 crReturnV;
8355 if (pktin) {
8356 bombout(("Unexpected data from server"
8357 " while waiting for agent"
8358 " response"));
8359 crStopV;
1983e559 8360 }
94cd7c3a 8361 } while (pktin || inlen > 0);
8362 vret = ssh->agent_response;
8363 s->retlen = ssh->agent_response_len;
8364 }
8365 s->ret = vret;
8366 sfree(s->agentreq);
8367 if (s->ret) {
b1650067 8368 if (s->retlen >= 9 &&
8369 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8370 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
94cd7c3a 8371 logevent("Sending Pageant's response");
8372 ssh2_add_sigblob(ssh, s->pktout,
8373 s->pkblob, s->pklen,
8374 s->ret + 9,
8375 GET_32BIT(s->ret + 5));
8376 ssh2_pkt_send(ssh, s->pktout);
8377 s->type = AUTH_TYPE_PUBLICKEY;
8378 } else {
8379 /* FIXME: less drastic response */
8380 bombout(("Pageant failed to answer challenge"));
8381 crStopV;
1983e559 8382 }
8383 }
1983e559 8384 }
94cd7c3a 8385
8386 /* Do we have any keys left to try? */
8387 if (s->pkblob_in_agent) {
8388 s->done_agent = TRUE;
8389 s->tried_pubkey_config = TRUE;
8390 } else {
8391 s->keyi++;
8392 if (s->keyi >= s->nkeys)
8393 s->done_agent = TRUE;
8394 }
1983e559 8395
edd0cb8a 8396 } else if (s->can_pubkey && s->publickey_blob &&
8397 !s->tried_pubkey_config) {
65a22376 8398
edd0cb8a 8399 struct ssh2_userkey *key; /* not live over crReturn */
8400 char *passphrase; /* not live over crReturn */
65a22376 8401
acab36bc 8402 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8403
edd0cb8a 8404 s->tried_pubkey_config = TRUE;
8405
65a22376 8406 /*
1408a877 8407 * Try the public key supplied in the configuration.
8408 *
8409 * First, offer the public blob to see if the server is
8410 * willing to accept it.
65a22376 8411 */
ff3187f6 8412 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8413 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8414 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8415 /* service requested */
8416 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8417 ssh2_pkt_addbool(s->pktout, FALSE);
8418 /* no signature included */
8419 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8420 ssh2_pkt_addstring_start(s->pktout);
8421 ssh2_pkt_addstring_data(s->pktout,
8422 (char *)s->publickey_blob,
8423 s->publickey_bloblen);
ff3187f6 8424 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 8425 logevent("Offered public key");
ff3187f6 8426
8427 crWaitUntilV(pktin);
edd0cb8a 8428 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8429 /* Key refused. Give up. */
8430 s->gotit = TRUE; /* reconsider message next loop */
8431 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8432 continue; /* process this new message */
45068b27 8433 }
edd0cb8a 8434 logevent("Offer of public key accepted");
af659722 8435
45068b27 8436 /*
edd0cb8a 8437 * Actually attempt a serious authentication using
8438 * the key.
45068b27 8439 */
edd0cb8a 8440 if (flags & FLAG_VERBOSE) {
8441 c_write_str(ssh, "Authenticating with public key \"");
8442 c_write_str(ssh, s->publickey_comment);
8443 c_write_str(ssh, "\"\r\n");
8444 }
8445 key = NULL;
8446 while (!key) {
8447 const char *error; /* not live over crReturn */
8448 if (s->publickey_encrypted) {
8449 /*
8450 * Get a passphrase from the user.
8451 */
8452 int ret; /* need not be kept over crReturn */
8453 s->cur_prompt = new_prompts(ssh->frontend);
8454 s->cur_prompt->to_server = FALSE;
8455 s->cur_prompt->name = dupstr("SSH key passphrase");
8456 add_prompt(s->cur_prompt,
8457 dupprintf("Passphrase for key \"%.100s\": ",
8458 s->publickey_comment),
b61f81bc 8459 FALSE);
edd0cb8a 8460 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8461 while (ret < 0) {
8462 ssh->send_ok = 1;
8463 crWaitUntilV(!pktin);
8464 ret = get_userpass_input(s->cur_prompt,
8465 in, inlen);
8466 ssh->send_ok = 0;
8467 }
8468 if (!ret) {
8469 /* Failed to get a passphrase. Terminate. */
8470 free_prompts(s->cur_prompt);
8471 ssh_disconnect(ssh, NULL,
8472 "Unable to authenticate",
8473 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8474 TRUE);
8475 crStopV;
85fdbe25 8476 }
edd0cb8a 8477 passphrase =
8478 dupstr(s->cur_prompt->prompts[0]->result);
8479 free_prompts(s->cur_prompt);
45068b27 8480 } else {
edd0cb8a 8481 passphrase = NULL; /* no passphrase needed */
45068b27 8482 }
1408a877 8483
edd0cb8a 8484 /*
8485 * Try decrypting the key.
8486 */
4a693cfc 8487 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8488 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
edd0cb8a 8489 if (passphrase) {
8490 /* burn the evidence */
dfb88efd 8491 smemclr(passphrase, strlen(passphrase));
edd0cb8a 8492 sfree(passphrase);
8493 }
8494 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8495 if (passphrase &&
8496 (key == SSH2_WRONG_PASSPHRASE)) {
8497 c_write_str(ssh, "Wrong passphrase\r\n");
8498 key = NULL;
8499 /* and loop again */
8500 } else {
8501 c_write_str(ssh, "Unable to load private key (");
8502 c_write_str(ssh, error);
8503 c_write_str(ssh, ")\r\n");
8504 key = NULL;
8505 break; /* try something else */
8506 }
1408a877 8507 }
65a22376 8508 }
65a22376 8509
edd0cb8a 8510 if (key) {
1dd353b5 8511 unsigned char *pkblob, *sigblob, *sigdata;
8512 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 8513 int p;
65a22376 8514
1408a877 8515 /*
8516 * We have loaded the private key and the server
8517 * has announced that it's willing to accept it.
8518 * Hallelujah. Generate a signature and send it.
8519 */
ff3187f6 8520 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8521 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8522 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8523 /* service requested */
8524 ssh2_pkt_addstring(s->pktout, "publickey");
8525 /* method */
ff3187f6 8526 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 8527 /* signature follows */
ff3187f6 8528 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 8529 pkblob = key->alg->public_blob(key->data,
8530 &pkblob_len);
ff3187f6 8531 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 8532 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8533 pkblob_len);
1408a877 8534
8535 /*
8536 * The data to be signed is:
8537 *
8538 * string session-id
8539 *
8540 * followed by everything so far placed in the
8541 * outgoing packet.
8542 */
b672f405 8543 sigdata_len = s->pktout->length - 5 + 4 +
8544 ssh->v2_session_id_len;
edd0cb8a 8545 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8546 sigdata_len -= 4;
92d60585 8547 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 8548 p = 0;
8549 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8550 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8551 p += 4;
8552 }
b672f405 8553 memcpy(sigdata+p, ssh->v2_session_id,
8554 ssh->v2_session_id_len);
8555 p += ssh->v2_session_id_len;
ff3187f6 8556 memcpy(sigdata+p, s->pktout->data + 5,
8557 s->pktout->length - 5);
edd0cb8a 8558 p += s->pktout->length - 5;
8559 assert(p == sigdata_len);
d8baa528 8560 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 8561 sigdata_len, &sigblob_len);
ff3187f6 8562 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 8563 sigblob, sigblob_len);
8564 sfree(pkblob);
8565 sfree(sigblob);
1408a877 8566 sfree(sigdata);
8567
ff3187f6 8568 ssh2_pkt_send(ssh, s->pktout);
8221906d 8569 logevent("Sent public key signature");
51470298 8570 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 8571 key->alg->freekey(key->data);
1408a877 8572 }
edd0cb8a 8573
42af6a67 8574#ifndef NO_GSSAPI
8575 } else if (s->can_gssapi && !s->tried_gssapi) {
8576
8577 /* GSSAPI Authentication */
8578
86557057 8579 int micoffset, len;
8580 char *data;
42af6a67 8581 Ssh_gss_buf mic;
8582 s->type = AUTH_TYPE_GSSAPI;
8583 s->tried_gssapi = TRUE;
8584 s->gotit = TRUE;
8585 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8586
b3d375b2 8587 /*
8588 * Pick the highest GSS library on the preference
8589 * list.
8590 */
8591 {
8592 int i, j;
8593 s->gsslib = NULL;
8594 for (i = 0; i < ngsslibs; i++) {
4a693cfc 8595 int want_id = conf_get_int_int(ssh->conf,
8596 CONF_ssh_gsslist, i);
1e00c92b 8597 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8598 if (ssh->gsslibs->libraries[j].id == want_id) {
8599 s->gsslib = &ssh->gsslibs->libraries[j];
b3d375b2 8600 goto got_gsslib; /* double break */
8601 }
8602 }
8603 got_gsslib:
8604 /*
8605 * We always expect to have found something in
8606 * the above loop: we only came here if there
8607 * was at least one viable GSS library, and the
8608 * preference list should always mention
8609 * everything and only change the order.
8610 */
8611 assert(s->gsslib);
8612 }
8613
8614 if (s->gsslib->gsslogmsg)
8615 logevent(s->gsslib->gsslogmsg);
8616
42af6a67 8617 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8618 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8619 ssh2_pkt_addstring(s->pktout, ssh->username);
42af6a67 8620 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8621 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8221906d 8622 logevent("Attempting GSSAPI authentication");
42af6a67 8623
8624 /* add mechanism info */
b3d375b2 8625 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
42af6a67 8626
8627 /* number of GSSAPI mechanisms */
8628 ssh2_pkt_adduint32(s->pktout,1);
8629
8630 /* length of OID + 2 */
86557057 8631 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
42af6a67 8632 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8633
8634 /* length of OID */
86557057 8635 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
42af6a67 8636
86557057 8637 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8638 s->gss_buf.length);
42af6a67 8639 ssh2_pkt_send(ssh, s->pktout);
8640 crWaitUntilV(pktin);
8641 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8642 logevent("GSSAPI authentication request refused");
8643 continue;
8644 }
8645
8646 /* check returned packet ... */
8647
86557057 8648 ssh_pkt_getstring(pktin, &data, &len);
8649 s->gss_rcvtok.value = data;
8650 s->gss_rcvtok.length = len;
8651 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8652 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8653 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8654 memcmp((char *)s->gss_rcvtok.value + 2,
8655 s->gss_buf.value,s->gss_buf.length) ) {
42af6a67 8656 logevent("GSSAPI authentication - wrong response from server");
8657 continue;
8658 }
8659
8660 /* now start running */
b3d375b2 8661 s->gss_stat = s->gsslib->import_name(s->gsslib,
8662 ssh->fullhostname,
8663 &s->gss_srv_name);
42af6a67 8664 if (s->gss_stat != SSH_GSS_OK) {
8665 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8666 logevent("GSSAPI import name failed - Bad service name");
8667 else
8668 logevent("GSSAPI import name failed");
8669 continue;
8670 }
8671
8672 /* fetch TGT into GSS engine */
b3d375b2 8673 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
42af6a67 8674
8675 if (s->gss_stat != SSH_GSS_OK) {
8676 logevent("GSSAPI authentication failed to get credentials");
b3d375b2 8677 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
42af6a67 8678 continue;
8679 }
8680
8681 /* initial tokens are empty */
86557057 8682 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
99a3b3c9 8683 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
42af6a67 8684
8685 /* now enter the loop */
8686 do {
b3d375b2 8687 s->gss_stat = s->gsslib->init_sec_context
8688 (s->gsslib,
8689 &s->gss_ctx,
8690 s->gss_srv_name,
4a693cfc 8691 conf_get_int(ssh->conf, CONF_gssapifwd),
b3d375b2 8692 &s->gss_rcvtok,
8693 &s->gss_sndtok);
42af6a67 8694
8695 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8696 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8697 logevent("GSSAPI authentication initialisation failed");
8698
b3d375b2 8699 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8700 &s->gss_buf) == SSH_GSS_OK) {
86557057 8701 logevent(s->gss_buf.value);
8702 sfree(s->gss_buf.value);
42af6a67 8703 }
8704
8705 break;
8706 }
8707 logevent("GSSAPI authentication initialised");
8708
8709 /* Client and server now exchange tokens until GSSAPI
8710 * no longer says CONTINUE_NEEDED */
8711
86557057 8712 if (s->gss_sndtok.length != 0) {
42af6a67 8713 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8714 ssh_pkt_addstring_start(s->pktout);
86557057 8715 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
42af6a67 8716 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8717 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
42af6a67 8718 }
8719
8720 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8721 crWaitUntilV(pktin);
8722 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8723 logevent("GSSAPI authentication - bad server response");
8724 s->gss_stat = SSH_GSS_FAILURE;
8725 break;
8726 }
86557057 8727 ssh_pkt_getstring(pktin, &data, &len);
8728 s->gss_rcvtok.value = data;
8729 s->gss_rcvtok.length = len;
42af6a67 8730 }
8731 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8732
8733 if (s->gss_stat != SSH_GSS_OK) {
b3d375b2 8734 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8735 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8736 continue;
8737 }
8738 logevent("GSSAPI authentication loop finished OK");
8739
8740 /* Now send the MIC */
8741
8742 s->pktout = ssh2_pkt_init(0);
8743 micoffset = s->pktout->length;
8744 ssh_pkt_addstring_start(s->pktout);
8745 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8746 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8747 ssh_pkt_addstring(s->pktout, ssh->username);
42af6a67 8748 ssh_pkt_addstring(s->pktout, "ssh-connection");
8749 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8750
86557057 8751 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8752 s->gss_buf.length = s->pktout->length - micoffset;
42af6a67 8753
b3d375b2 8754 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
42af6a67 8755 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8756 ssh_pkt_addstring_start(s->pktout);
86557057 8757 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
42af6a67 8758 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8759 s->gsslib->free_mic(s->gsslib, &mic);
42af6a67 8760
8761 s->gotit = FALSE;
8762
b3d375b2 8763 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8764 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8765 continue;
8766#endif
edd0cb8a 8767 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8768
8769 /*
8770 * Keyboard-interactive authentication.
8771 */
edd0cb8a 8772
edd0cb8a 8773 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8774
acab36bc 8775 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 8776
8777 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8778 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8779 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8780 /* service requested */
8781 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8782 /* method */
8783 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8784 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8785 ssh2_pkt_send(ssh, s->pktout);
8221906d 8786
8787 logevent("Attempting keyboard-interactive authentication");
edd0cb8a 8788
8789 crWaitUntilV(pktin);
8790 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8791 /* Server is not willing to do keyboard-interactive
b8e3173d 8792 * at all (or, bizarrely but legally, accepts the
8793 * user without actually issuing any prompts).
8794 * Give up on it entirely. */
edd0cb8a 8795 s->gotit = TRUE;
edd0cb8a 8796 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8797 s->kbd_inter_refused = TRUE; /* don't try it again */
8798 continue;
8799 }
8800
8801 /*
b8e3173d 8802 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 8803 */
b8e3173d 8804 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 8805
b8e3173d 8806 char *name, *inst, *lang;
8807 int name_len, inst_len, lang_len;
8808 int i;
8809
8810 /*
8811 * We've got a fresh USERAUTH_INFO_REQUEST.
8812 * Get the preamble and start building a prompt.
8813 */
8814 ssh_pkt_getstring(pktin, &name, &name_len);
8815 ssh_pkt_getstring(pktin, &inst, &inst_len);
8816 ssh_pkt_getstring(pktin, &lang, &lang_len);
8817 s->cur_prompt = new_prompts(ssh->frontend);
8818 s->cur_prompt->to_server = TRUE;
edd0cb8a 8819
b8e3173d 8820 /*
9ea10e78 8821 * Get any prompt(s) from the packet.
b8e3173d 8822 */
8823 s->num_prompts = ssh_pkt_getuint32(pktin);
8824 for (i = 0; i < s->num_prompts; i++) {
8825 char *prompt;
8826 int prompt_len;
8827 int echo;
8828 static char noprompt[] =
8829 "<server failed to send prompt>: ";
8830
8831 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8832 echo = ssh2_pkt_getbool(pktin);
8833 if (!prompt_len) {
8834 prompt = noprompt;
8835 prompt_len = lenof(noprompt)-1;
8836 }
8837 add_prompt(s->cur_prompt,
8838 dupprintf("%.*s", prompt_len, prompt),
b61f81bc 8839 echo);
edd0cb8a 8840 }
b8e3173d 8841
9874c9d7 8842 if (name_len) {
8843 /* FIXME: better prefix to distinguish from
8844 * local prompts? */
8845 s->cur_prompt->name =
8846 dupprintf("SSH server: %.*s", name_len, name);
8847 s->cur_prompt->name_reqd = TRUE;
8848 } else {
8849 s->cur_prompt->name =
8850 dupstr("SSH server authentication");
8851 s->cur_prompt->name_reqd = FALSE;
8852 }
8853 /* We add a prefix to try to make it clear that a prompt
8854 * has come from the server.
8855 * FIXME: ugly to print "Using..." in prompt _every_
8856 * time round. Can this be done more subtly? */
8857 /* Special case: for reasons best known to themselves,
8858 * some servers send k-i requests with no prompts and
8859 * nothing to display. Keep quiet in this case. */
8860 if (s->num_prompts || name_len || inst_len) {
8861 s->cur_prompt->instruction =
8862 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8863 inst_len ? "\n" : "", inst_len, inst);
8864 s->cur_prompt->instr_reqd = TRUE;
8865 } else {
8866 s->cur_prompt->instr_reqd = FALSE;
8867 }
8868
b8e3173d 8869 /*
9ea10e78 8870 * Display any instructions, and get the user's
8871 * response(s).
b8e3173d 8872 */
9ea10e78 8873 {
b8e3173d 8874 int ret; /* not live over crReturn */
8875 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8876 while (ret < 0) {
8877 ssh->send_ok = 1;
8878 crWaitUntilV(!pktin);
8879 ret = get_userpass_input(s->cur_prompt, in, inlen);
8880 ssh->send_ok = 0;
8881 }
8882 if (!ret) {
8883 /*
8884 * Failed to get responses. Terminate.
8885 */
8886 free_prompts(s->cur_prompt);
8887 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8888 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8889 TRUE);
8890 crStopV;
8891 }
edd0cb8a 8892 }
b8e3173d 8893
8894 /*
9ea10e78 8895 * Send the response(s) to the server.
b8e3173d 8896 */
8897 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 8898 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8899 for (i=0; i < s->num_prompts; i++) {
8900 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8901 ssh2_pkt_addstring(s->pktout,
8902 s->cur_prompt->prompts[i]->result);
8903 end_log_omission(ssh, s->pktout);
8904 }
18524056 8905 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 8906
c69784c0 8907 /*
8908 * Free the prompts structure from this iteration.
8909 * If there's another, a new one will be allocated
8910 * when we return to the top of this while loop.
8911 */
8912 free_prompts(s->cur_prompt);
8913
b8e3173d 8914 /*
8915 * Get the next packet in case it's another
8916 * INFO_REQUEST.
8917 */
8918 crWaitUntilV(pktin);
8919
edd0cb8a 8920 }
8921
8922 /*
b8e3173d 8923 * We should have SUCCESS or FAILURE now.
edd0cb8a 8924 */
b8e3173d 8925 s->gotit = TRUE;
edd0cb8a 8926
8927 } else if (s->can_passwd) {
8928
8929 /*
8930 * Plain old password authentication.
8931 */
8932 int ret; /* not live over crReturn */
e955d348 8933 int changereq_first_time; /* not live over crReturn */
edd0cb8a 8934
acab36bc 8935 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 8936
8937 s->cur_prompt = new_prompts(ssh->frontend);
8938 s->cur_prompt->to_server = TRUE;
8939 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 8940 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8941 ssh->username,
edd0cb8a 8942 ssh->savedhost),
b61f81bc 8943 FALSE);
edd0cb8a 8944
8945 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8946 while (ret < 0) {
8947 ssh->send_ok = 1;
8948 crWaitUntilV(!pktin);
8949 ret = get_userpass_input(s->cur_prompt, in, inlen);
8950 ssh->send_ok = 0;
8951 }
8952 if (!ret) {
8953 /*
8954 * Failed to get responses. Terminate.
8955 */
8956 free_prompts(s->cur_prompt);
8957 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8958 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8959 TRUE);
8960 crStopV;
8961 }
e955d348 8962 /*
8963 * Squirrel away the password. (We may need it later if
8964 * asked to change it.)
8965 */
8966 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8967 free_prompts(s->cur_prompt);
edd0cb8a 8968
8969 /*
8970 * Send the password packet.
8971 *
95d2d262 8972 * We pad out the password packet to 256 bytes to make
8973 * it harder for an attacker to find the length of the
8974 * user's password.
1408a877 8975 *
95d2d262 8976 * Anyone using a password longer than 256 bytes
8977 * probably doesn't have much to worry about from
1408a877 8978 * people who find out how long their password is!
65a22376 8979 */
ff3187f6 8980 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8981 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8982 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8983 /* service requested */
ff3187f6 8984 ssh2_pkt_addstring(s->pktout, "password");
8985 ssh2_pkt_addbool(s->pktout, FALSE);
8986 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 8987 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 8988 end_log_omission(ssh, s->pktout);
18524056 8989 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 8990 logevent("Sent password");
28f4d4f0 8991 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 8992
e955d348 8993 /*
8994 * Wait for next packet, in case it's a password change
8995 * request.
8996 */
8997 crWaitUntilV(pktin);
8998 changereq_first_time = TRUE;
8999
9000 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9001
9002 /*
9003 * We're being asked for a new password
9004 * (perhaps not for the first time).
9005 * Loop until the server accepts it.
9006 */
9007
9008 int got_new = FALSE; /* not live over crReturn */
9009 char *prompt; /* not live over crReturn */
9010 int prompt_len; /* not live over crReturn */
9011
9012 {
9013 char *msg;
9014 if (changereq_first_time)
9015 msg = "Server requested password change";
9016 else
9017 msg = "Server rejected new password";
9018 logevent(msg);
9019 c_write_str(ssh, msg);
9020 c_write_str(ssh, "\r\n");
9021 }
9022
9023 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9024
9025 s->cur_prompt = new_prompts(ssh->frontend);
9026 s->cur_prompt->to_server = TRUE;
9027 s->cur_prompt->name = dupstr("New SSH password");
9028 s->cur_prompt->instruction =
9029 dupprintf("%.*s", prompt_len, prompt);
9030 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 9031 /*
9032 * There's no explicit requirement in the protocol
9033 * for the "old" passwords in the original and
9034 * password-change messages to be the same, and
9035 * apparently some Cisco kit supports password change
9036 * by the user entering a blank password originally
9037 * and the real password subsequently, so,
9038 * reluctantly, we prompt for the old password again.
9039 *
9040 * (On the other hand, some servers don't even bother
9041 * to check this field.)
9042 */
9043 add_prompt(s->cur_prompt,
9044 dupstr("Current password (blank for previously entered password): "),
b61f81bc 9045 FALSE);
e955d348 9046 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
b61f81bc 9047 FALSE);
e955d348 9048 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
b61f81bc 9049 FALSE);
e955d348 9050
9051 /*
9052 * Loop until the user manages to enter the same
9053 * password twice.
9054 */
9055 while (!got_new) {
9056
9057 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9058 while (ret < 0) {
9059 ssh->send_ok = 1;
9060 crWaitUntilV(!pktin);
9061 ret = get_userpass_input(s->cur_prompt, in, inlen);
9062 ssh->send_ok = 0;
9063 }
9064 if (!ret) {
9065 /*
9066 * Failed to get responses. Terminate.
9067 */
9068 /* burn the evidence */
9069 free_prompts(s->cur_prompt);
dfb88efd 9070 smemclr(s->password, strlen(s->password));
e955d348 9071 sfree(s->password);
9072 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9073 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9074 TRUE);
9075 crStopV;
9076 }
9077
9078 /*
d9add7bc 9079 * If the user specified a new original password
9080 * (IYSWIM), overwrite any previously specified
9081 * one.
9082 * (A side effect is that the user doesn't have to
9083 * re-enter it if they louse up the new password.)
9084 */
9085 if (s->cur_prompt->prompts[0]->result[0]) {
dfb88efd 9086 smemclr(s->password, strlen(s->password));
d9add7bc 9087 /* burn the evidence */
9088 sfree(s->password);
9089 s->password =
9090 dupstr(s->cur_prompt->prompts[0]->result);
9091 }
9092
9093 /*
9094 * Check the two new passwords match.
e955d348 9095 */
d9add7bc 9096 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9097 s->cur_prompt->prompts[2]->result)
e955d348 9098 == 0);
9099 if (!got_new)
9100 /* They don't. Silly user. */
9101 c_write_str(ssh, "Passwords do not match\r\n");
9102
9103 }
9104
9105 /*
9106 * Send the new password (along with the old one).
9107 * (see above for padding rationale)
9108 */
9109 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 9110 ssh2_pkt_addstring(s->pktout, ssh->username);
e955d348 9111 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9112 /* service requested */
9113 ssh2_pkt_addstring(s->pktout, "password");
9114 ssh2_pkt_addbool(s->pktout, TRUE);
9115 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9116 ssh2_pkt_addstring(s->pktout, s->password);
9117 ssh2_pkt_addstring(s->pktout,
d9add7bc 9118 s->cur_prompt->prompts[1]->result);
e955d348 9119 free_prompts(s->cur_prompt);
9120 end_log_omission(ssh, s->pktout);
18524056 9121 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 9122 logevent("Sent new password");
9123
9124 /*
9125 * Now see what the server has to say about it.
9126 * (If it's CHANGEREQ again, it's not happy with the
9127 * new password.)
9128 */
9129 crWaitUntilV(pktin);
9130 changereq_first_time = FALSE;
9131
9132 }
9133
9134 /*
9135 * We need to reexamine the current pktin at the top
9136 * of the loop. Either:
9137 * - we weren't asked to change password at all, in
9138 * which case it's a SUCCESS or FAILURE with the
9139 * usual meaning
9140 * - we sent a new password, and the server was
9141 * either OK with it (SUCCESS or FAILURE w/partial
9142 * success) or unhappy with the _old_ password
9143 * (FAILURE w/o partial success)
9144 * In any of these cases, we go back to the top of
9145 * the loop and start again.
9146 */
9147 s->gotit = TRUE;
9148
9149 /*
9150 * We don't need the old password any more, in any
9151 * case. Burn the evidence.
9152 */
dfb88efd 9153 smemclr(s->password, strlen(s->password));
e955d348 9154 sfree(s->password);
9155
1408a877 9156 } else {
854caca5 9157 char *str = dupprintf("No supported authentication methods available"
9158 " (server sent: %.*s)",
9159 methlen, methods);
edd0cb8a 9160
854caca5 9161 ssh_disconnect(ssh, str,
9e296bfa 9162 "No supported authentication methods available",
9163 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9164 FALSE);
854caca5 9165 sfree(str);
9166
7ffdbc1a 9167 crStopV;
edd0cb8a 9168
65a22376 9169 }
edd0cb8a 9170
65a22376 9171 }
a1a1fae4 9172 }
6bbce591 9173 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 9174
edd0cb8a 9175 /* Clear up various bits and pieces from authentication. */
9176 if (s->publickey_blob) {
9177 sfree(s->publickey_blob);
9178 sfree(s->publickey_comment);
9179 }
94cd7c3a 9180 if (s->agent_response)
9181 sfree(s->agent_response);
edd0cb8a 9182
ab18ccff 9183 if (s->userauth_success) {
9184 /*
9185 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9186 * packets since. Signal the transport layer to consider enacting
9187 * delayed compression.
9188 *
9189 * (Relying on we_are_in is not sufficient, as
9190 * draft-miller-secsh-compression-delayed is quite clear that it
9191 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9192 * become set for other reasons.)
9193 */
9194 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9195 }
9196
7cca0d81 9197 /*
a1a1fae4 9198 * Now the connection protocol has started, one way or another.
7cca0d81 9199 */
9200
0ed48730 9201 ssh->channels = newtree234(ssh_channelcmp);
9202
7cca0d81 9203 /*
b09eaa88 9204 * Set up handlers for some connection protocol messages, so we
9205 * don't have to handle them repeatedly in this coroutine.
9206 */
9207 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9208 ssh2_msg_channel_window_adjust;
51df0ab5 9209 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9210 ssh2_msg_global_request;
b09eaa88 9211
9212 /*
0ed48730 9213 * Create the main session channel.
7cca0d81 9214 */
4a693cfc 9215 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
feb02b4e 9216 ssh->mainchan = NULL;
4e63d9b2 9217 } else {
feb02b4e 9218 ssh->mainchan = snew(struct ssh_channel);
9219 ssh->mainchan->ssh = ssh;
94bdfe40 9220 ssh2_channel_init(ssh->mainchan);
feb02b4e 9221
4e63d9b2 9222 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9223 /*
9224 * Just start a direct-tcpip channel and use it as the main
9225 * channel.
9226 */
9227 ssh_send_port_open(ssh->mainchan,
9228 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9229 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9230 "main channel");
9231 ssh->ncmode = TRUE;
9232 } else {
9233 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9234 logevent("Opening session as main channel");
9235 ssh2_pkt_send(ssh, s->pktout);
9236 ssh->ncmode = FALSE;
feb02b4e 9237 }
ff3187f6 9238 crWaitUntilV(pktin);
9239 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4e63d9b2 9240 bombout(("Server refused to open channel"));
0ed48730 9241 crStopV;
9242 /* FIXME: error data comes back in FAILURE packet */
9243 }
ff3187f6 9244 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 9245 bombout(("Server's channel confirmation cited wrong channel"));
9246 crStopV;
9247 }
ff3187f6 9248 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 9249 ssh->mainchan->halfopen = FALSE;
0ed48730 9250 ssh->mainchan->type = CHAN_MAINSESSION;
ff3187f6 9251 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9252 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 9253 add234(ssh->channels, ssh->mainchan);
62638676 9254 update_specials_menu(ssh->frontend);
4e63d9b2 9255 logevent("Opened main channel");
feb02b4e 9256 }
7cca0d81 9257
9258 /*
51df0ab5 9259 * Now we have a channel, make dispatch table entries for
9260 * general channel-based messages.
9261 */
9262 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9263 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9264 ssh2_msg_channel_data;
9265 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9266 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9267 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9268 ssh2_msg_channel_open_confirmation;
9269 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9270 ssh2_msg_channel_open_failure;
9271 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9272 ssh2_msg_channel_request;
9273 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9274 ssh2_msg_channel_open;
ebbc254d 9275 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9276 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9277
51df0ab5 9278
4a693cfc 9279 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
3361b80a 9280 /*
9281 * This message indicates to the server that we promise
9282 * not to try to run any other channel in parallel with
9283 * this one, so it's safe for it to advertise a very large
9284 * window and leave the flow control to TCP.
9285 */
134f5ece 9286 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9287 "simple@putty.projects.tartarus.org",
9288 NULL, NULL);
3361b80a 9289 ssh2_pkt_send(ssh, s->pktout);
9290 }
9291
51df0ab5 9292 /*
c99deca4 9293 * Enable port forwardings.
9294 */
9295 ssh_setup_portfwd(ssh, ssh->conf);
9296
e03299cb 9297 if (ssh->mainchan && !ssh->ncmode) {
9298 /*
9299 * Send the CHANNEL_REQUESTS for the main session channel.
9300 * Each one is handled by its own little asynchronous
9301 * co-routine.
9302 */
c99deca4 9303
e03299cb 9304 /* Potentially enable X11 forwarding. */
9305 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9306 (ssh->x11disp =
9307 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9308 conf_get_int(ssh->conf, CONF_x11_auth),
9309 ssh->conf)))
9310 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
bc240b21 9311
e03299cb 9312 /* Potentially enable agent forwarding. */
9313 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9314 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
36c2a3e9 9315
e03299cb 9316 /* Now allocate a pty for the session. */
9317 if (!conf_get_int(ssh->conf, CONF_nopty))
9318 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
7cca0d81 9319
e03299cb 9320 /* Send environment variables. */
9321 ssh2_setup_env(ssh->mainchan, NULL, NULL);
73feed4f 9322
e03299cb 9323 /*
9324 * Start a shell or a remote command. We may have to attempt
9325 * this twice if the config data has provided a second choice
9326 * of command.
9327 */
9328 while (1) {
9329 int subsys;
9330 char *cmd;
fd5e5847 9331
e03299cb 9332 if (ssh->fallback_cmd) {
9333 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9334 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9335 } else {
9336 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9337 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9338 }
fd5e5847 9339
e03299cb 9340 if (subsys) {
9341 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9342 ssh2_response_authconn, NULL);
9343 ssh2_pkt_addstring(s->pktout, cmd);
9344 } else if (*cmd) {
9345 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9346 ssh2_response_authconn, NULL);
9347 ssh2_pkt_addstring(s->pktout, cmd);
9348 } else {
9349 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9350 ssh2_response_authconn, NULL);
9351 }
9352 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 9353
e03299cb 9354 crWaitUntilV(pktin);
b09eaa88 9355
e03299cb 9356 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9357 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9358 bombout(("Unexpected response to shell/command request:"
9359 " packet type %d", pktin->type));
9360 crStopV;
9361 }
9362 /*
9363 * We failed to start the command. If this is the
9364 * fallback command, we really are finished; if it's
9365 * not, and if the fallback command exists, try falling
9366 * back to it before complaining.
9367 */
9368 if (!ssh->fallback_cmd &&
9369 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9370 logevent("Primary command failed; attempting fallback");
9371 ssh->fallback_cmd = TRUE;
9372 continue;
9373 }
9374 bombout(("Server refused to start a shell/command"));
7ffdbc1a 9375 crStopV;
e03299cb 9376 } else {
9377 logevent("Started a shell/command");
fd5e5847 9378 }
e03299cb 9379 break;
32874aea 9380 }
e03299cb 9381 } else {
9382 ssh->editing = ssh->echoing = TRUE;
7cca0d81 9383 }
9384
51470298 9385 ssh->state = SSH_STATE_SESSION;
9386 if (ssh->size_needed)
9387 ssh_size(ssh, ssh->term_width, ssh->term_height);
9388 if (ssh->eof_needed)
9389 ssh_special(ssh, TS_EOF);
6e48c3fe 9390
7cca0d81 9391 /*
9392 * Transfer data!
9393 */
b9d7bcad 9394 if (ssh->ldisc)
9395 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 9396 if (ssh->mainchan)
9397 ssh->send_ok = 1;
7cca0d81 9398 while (1) {
e5574168 9399 crReturnV;
51470298 9400 s->try_send = FALSE;
ff3187f6 9401 if (pktin) {
2b7540a7 9402
51df0ab5 9403 /*
9404 * _All_ the connection-layer packets we expect to
9405 * receive are now handled by the dispatch table.
9406 * Anything that reaches here must be bogus.
9407 */
32874aea 9408
51df0ab5 9409 bombout(("Strange packet received: type %d", pktin->type));
9410 crStopV;
0ed48730 9411 } else if (ssh->mainchan) {
32874aea 9412 /*
9413 * We have spare data. Add it to the channel buffer.
9414 */
d8baa528 9415 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 9416 s->try_send = TRUE;
32874aea 9417 }
51470298 9418 if (s->try_send) {
32874aea 9419 int i;
9420 struct ssh_channel *c;
9421 /*
9422 * Try to send data on all channels if we can.
9423 */
1bfc7e93 9424 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
78280721 9425 ssh2_try_send_and_unthrottle(ssh, c);
7cca0d81 9426 }
e5574168 9427 }
9428
9429 crFinishV;
9430}
9431
9432/*
2e85c969 9433 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 9434 */
409bfa77 9435static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 9436{
9437 /* log reason code in disconnect message */
9438 char *buf, *msg;
60860bc3 9439 int reason, msglen;
b09eaa88 9440
9441 reason = ssh_pkt_getuint32(pktin);
9442 ssh_pkt_getstring(pktin, &msg, &msglen);
9443
9444 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9445 buf = dupprintf("Received disconnect message (%s)",
9446 ssh2_disconnect_reasons[reason]);
9447 } else {
9448 buf = dupprintf("Received disconnect message (unknown"
9449 " type %d)", reason);
9450 }
9451 logevent(buf);
9452 sfree(buf);
60860bc3 9453 buf = dupprintf("Disconnection message text: %.*s",
9454 msglen, msg);
b09eaa88 9455 logevent(buf);
60860bc3 9456 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
b09eaa88 9457 reason,
9458 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9459 ssh2_disconnect_reasons[reason] : "unknown",
60860bc3 9460 msglen, msg));
b09eaa88 9461 sfree(buf);
9462}
9463
409bfa77 9464static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 9465{
9466 /* log the debug message */
fb983202 9467 char *msg;
b09eaa88 9468 int msglen;
b09eaa88 9469
3ab79841 9470 /* XXX maybe we should actually take notice of the return value */
9471 ssh2_pkt_getbool(pktin);
b09eaa88 9472 ssh_pkt_getstring(pktin, &msg, &msglen);
9473
fb983202 9474 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 9475}
9476
bc074147 9477static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9478{
9479 do_ssh2_transport(ssh, NULL, 0, pktin);
9480}
9481
9482/*
9483 * Called if we receive a packet that isn't allowed by the protocol.
9484 * This only applies to packets whose meaning PuTTY understands.
9485 * Entirely unknown packets are handled below.
9486 */
9487static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9488{
9489 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9490 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9491 pktin->type));
9492 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
1418b055 9493 sfree(buf);
bc074147 9494}
9495
409bfa77 9496static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 9497{
9498 struct Packet *pktout;
9499 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9500 ssh2_pkt_adduint32(pktout, pktin->sequence);
9501 /*
9502 * UNIMPLEMENTED messages MUST appear in the same order as the
9503 * messages they respond to. Hence, never queue them.
9504 */
9505 ssh2_pkt_send_noqueue(ssh, pktout);
9506}
9507
9508/*
2e85c969 9509 * Handle the top-level SSH-2 protocol.
7cca0d81 9510 */
b09eaa88 9511static void ssh2_protocol_setup(Ssh ssh)
9512{
9513 int i;
9514
9515 /*
9516 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9517 */
9518 for (i = 0; i < 256; i++)
9519 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9520
9521 /*
bc074147 9522 * Initially, we only accept transport messages (and a few generic
9523 * ones). do_ssh2_authconn will add more when it starts.
9524 * Messages that are understood but not currently acceptable go to
9525 * ssh2_msg_unexpected.
b09eaa88 9526 */
bc074147 9527 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9528 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9529 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9530 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9531 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9532 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9533 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9534 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9535 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9536 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9537 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9538 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9539 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9540 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9541 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9542 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9543 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9544 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9545 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9546 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9547 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9548 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9549 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9550 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9551 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9552 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9553 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9554 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9555 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9556 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9557 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9558 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9559 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
b09eaa88 9560
9561 /*
bc074147 9562 * These messages have a special handler from the start.
b09eaa88 9563 */
9564 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 9565 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 9566 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9567}
9568
d719927e 9569static void ssh2_timer(void *ctx, unsigned long now)
9442dd57 9570{
9571 Ssh ssh = (Ssh)ctx;
9572
ecbb0000 9573 if (ssh->state == SSH_STATE_CLOSED)
9574 return;
9575
4a693cfc 9576 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
d719927e 9577 now == ssh->next_rekey) {
f382c87d 9578 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 9579 }
9580}
9581
1c1a7262 9582static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 9583 struct Packet *pktin)
7cca0d81 9584{
1c1a7262 9585 unsigned char *in = (unsigned char *)vin;
b09eaa88 9586 if (ssh->state == SSH_STATE_CLOSED)
9587 return;
9588
9442dd57 9589 if (pktin) {
9590 ssh->incoming_data_size += pktin->encrypted_len;
9591 if (!ssh->kex_in_progress &&
d57f70af 9592 ssh->max_data_size != 0 &&
9593 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9594 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 9595 }
9596
bc074147 9597 if (pktin)
b09eaa88 9598 ssh->packet_dispatch[pktin->type](ssh, pktin);
bc074147 9599 else if (!ssh->protocol_initial_phase_done)
9600 do_ssh2_transport(ssh, in, inlen, pktin);
9601 else
b09eaa88 9602 do_ssh2_authconn(ssh, in, inlen, pktin);
7cca0d81 9603}
9604
4a693cfc 9605static void ssh_cache_conf_values(Ssh ssh)
9606{
9607 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9608}
9609
7cca0d81 9610/*
8df7a775 9611 * Called to set up the connection.
374330e2 9612 *
9613 * Returns an error message, or NULL on success.
374330e2 9614 */
cbe2d68f 9615static const char *ssh_init(void *frontend_handle, void **backend_handle,
4a693cfc 9616 Conf *conf, char *host, int port, char **realhost,
9617 int nodelay, int keepalive)
32874aea 9618{
cbe2d68f 9619 const char *p;
51470298 9620 Ssh ssh;
9621
3d88e64d 9622 ssh = snew(struct ssh_tag);
4a693cfc 9623 ssh->conf = conf_copy(conf);
9624 ssh_cache_conf_values(ssh);
125105d1 9625 ssh->version = 0; /* when not ready yet */
51470298 9626 ssh->s = NULL;
9627 ssh->cipher = NULL;
371e569c 9628 ssh->v1_cipher_ctx = NULL;
0183b242 9629 ssh->crcda_ctx = NULL;
51470298 9630 ssh->cscipher = NULL;
371e569c 9631 ssh->cs_cipher_ctx = NULL;
51470298 9632 ssh->sccipher = NULL;
371e569c 9633 ssh->sc_cipher_ctx = NULL;
51470298 9634 ssh->csmac = NULL;
a8327734 9635 ssh->cs_mac_ctx = NULL;
51470298 9636 ssh->scmac = NULL;
e0e1a00d 9637 ssh->sc_mac_ctx = NULL;
51470298 9638 ssh->cscomp = NULL;
5366aed8 9639 ssh->cs_comp_ctx = NULL;
51470298 9640 ssh->sccomp = NULL;
5366aed8 9641 ssh->sc_comp_ctx = NULL;
51470298 9642 ssh->kex = NULL;
389aa499 9643 ssh->kex_ctx = NULL;
51470298 9644 ssh->hostkey = NULL;
9645 ssh->exitcode = -1;
ac934965 9646 ssh->close_expected = FALSE;
9e296bfa 9647 ssh->clean_exit = FALSE;
51470298 9648 ssh->state = SSH_STATE_PREPACKET;
9649 ssh->size_needed = FALSE;
9650 ssh->eof_needed = FALSE;
b9d7bcad 9651 ssh->ldisc = NULL;
a8327734 9652 ssh->logctx = NULL;
51470298 9653 ssh->deferred_send_data = NULL;
9654 ssh->deferred_len = 0;
9655 ssh->deferred_size = 0;
9656 ssh->fallback_cmd = 0;
acab36bc 9657 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9658 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8def70c3 9659 ssh->x11disp = NULL;
be738459 9660 ssh->v1_compressing = FALSE;
51470298 9661 ssh->v2_outgoing_sequence = 0;
9662 ssh->ssh1_rdpkt_crstate = 0;
9663 ssh->ssh2_rdpkt_crstate = 0;
51470298 9664 ssh->ssh_gotdata_crstate = 0;
b09eaa88 9665 ssh->do_ssh1_connection_crstate = 0;
51470298 9666 ssh->do_ssh_init_state = NULL;
9667 ssh->do_ssh1_login_state = NULL;
9668 ssh->do_ssh2_transport_state = NULL;
9669 ssh->do_ssh2_authconn_state = NULL;
4320baf7 9670 ssh->v_c = NULL;
9671 ssh->v_s = NULL;
6571dbfd 9672 ssh->mainchan = NULL;
968d2d92 9673 ssh->throttled_all = 0;
9674 ssh->v1_stdout_throttling = 0;
590f6a5f 9675 ssh->queue = NULL;
9676 ssh->queuelen = ssh->queuesize = 0;
9677 ssh->queueing = FALSE;
06fadff5 9678 ssh->qhead = ssh->qtail = NULL;
e13bba36 9679 ssh->deferred_rekey_reason = NULL;
3d9449a1 9680 bufchain_init(&ssh->queued_incoming_data);
9681 ssh->frozen = FALSE;
4a693cfc 9682 ssh->username = NULL;
bc06669b 9683 ssh->sent_console_eof = FALSE;
4a202fc6 9684 ssh->got_pty = FALSE;
51470298 9685
9686 *backend_handle = ssh;
32874aea 9687
8f203108 9688#ifdef MSCRYPTOAPI
32874aea 9689 if (crypto_startup() == 0)
8f203108 9690 return "Microsoft high encryption pack not installed!";
9691#endif
374330e2 9692
51470298 9693 ssh->frontend = frontend_handle;
4a693cfc 9694 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9695 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
887035a5 9696
fabd1805 9697 ssh->channels = NULL;
9698 ssh->rportfwds = NULL;
f47a5ffb 9699 ssh->portfwds = NULL;
fabd1805 9700
51470298 9701 ssh->send_ok = 0;
9702 ssh->editing = 0;
9703 ssh->echoing = 0;
ff68564b 9704 ssh->conn_throttle_count = 0;
51470298 9705 ssh->overall_bufsize = 0;
9706 ssh->fallback_cmd = 0;
8df7a775 9707
3648d4c5 9708 ssh->protocol = NULL;
9709
b09eaa88 9710 ssh->protocol_initial_phase_done = FALSE;
9711
39934deb 9712 ssh->pinger = NULL;
9713
9442dd57 9714 ssh->incoming_data_size = ssh->outgoing_data_size =
9715 ssh->deferred_data_size = 0L;
4a693cfc 9716 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9717 CONF_ssh_rekey_data));
9442dd57 9718 ssh->kex_in_progress = FALSE;
9719
1e00c92b 9720#ifndef NO_GSSAPI
9721 ssh->gsslibs = NULL;
9722#endif
9723
79bf227b 9724 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 9725 if (p != NULL)
9726 return p;
374330e2 9727
5d17ccfc 9728 random_ref();
9729
374330e2 9730 return NULL;
9731}
9732
fabd1805 9733static void ssh_free(void *handle)
9734{
9735 Ssh ssh = (Ssh) handle;
9736 struct ssh_channel *c;
9737 struct ssh_rportfwd *pf;
9738
9739 if (ssh->v1_cipher_ctx)
9740 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9741 if (ssh->cs_cipher_ctx)
9742 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9743 if (ssh->sc_cipher_ctx)
9744 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9745 if (ssh->cs_mac_ctx)
9746 ssh->csmac->free_context(ssh->cs_mac_ctx);
9747 if (ssh->sc_mac_ctx)
9748 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 9749 if (ssh->cs_comp_ctx) {
9750 if (ssh->cscomp)
9751 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9752 else
9753 zlib_compress_cleanup(ssh->cs_comp_ctx);
9754 }
9755 if (ssh->sc_comp_ctx) {
9756 if (ssh->sccomp)
9757 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9758 else
9759 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9760 }
fabd1805 9761 if (ssh->kex_ctx)
9762 dh_cleanup(ssh->kex_ctx);
9763 sfree(ssh->savedhost);
9764
590f6a5f 9765 while (ssh->queuelen-- > 0)
9766 ssh_free_packet(ssh->queue[ssh->queuelen]);
9767 sfree(ssh->queue);
9768
06fadff5 9769 while (ssh->qhead) {
9770 struct queued_handler *qh = ssh->qhead;
9771 ssh->qhead = qh->next;
8a9ec857 9772 sfree(qh);
06fadff5 9773 }
9774 ssh->qhead = ssh->qtail = NULL;
9775
fabd1805 9776 if (ssh->channels) {
9777 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9778 switch (c->type) {
9779 case CHAN_X11:
9780 if (c->u.x11.s != NULL)
9781 x11_close(c->u.x11.s);
9782 break;
9783 case CHAN_SOCKDATA:
409eca86 9784 case CHAN_SOCKDATA_DORMANT:
fabd1805 9785 if (c->u.pfd.s != NULL)
9786 pfd_close(c->u.pfd.s);
9787 break;
9788 }
3620f307 9789 if (ssh->version == 2) {
9790 struct outstanding_channel_request *ocr, *nocr;
9791 ocr = c->v.v2.chanreq_head;
9792 while (ocr) {
9793 ocr->handler(c, NULL, ocr->ctx);
9794 nocr = ocr->next;
9795 sfree(ocr);
9796 ocr = nocr;
9797 }
9798 bufchain_clear(&c->v.v2.outbuffer);
9799 }
fabd1805 9800 sfree(c);
9801 }
9802 freetree234(ssh->channels);
cdb52705 9803 ssh->channels = NULL;
fabd1805 9804 }
9805
9806 if (ssh->rportfwds) {
9807 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8aea57fd 9808 free_rportfwd(pf);
fabd1805 9809 freetree234(ssh->rportfwds);
cdb52705 9810 ssh->rportfwds = NULL;
fabd1805 9811 }
9812 sfree(ssh->deferred_send_data);
8def70c3 9813 if (ssh->x11disp)
9814 x11_free_display(ssh->x11disp);
fabd1805 9815 sfree(ssh->do_ssh_init_state);
9816 sfree(ssh->do_ssh1_login_state);
9817 sfree(ssh->do_ssh2_transport_state);
9818 sfree(ssh->do_ssh2_authconn_state);
4320baf7 9819 sfree(ssh->v_c);
9820 sfree(ssh->v_s);
42af6a67 9821 sfree(ssh->fullhostname);
679539d7 9822 if (ssh->crcda_ctx) {
9823 crcda_free_context(ssh->crcda_ctx);
9824 ssh->crcda_ctx = NULL;
9825 }
fabd1805 9826 if (ssh->s)
ac934965 9827 ssh_do_close(ssh, TRUE);
9442dd57 9828 expire_timer_context(ssh);
39934deb 9829 if (ssh->pinger)
9830 pinger_free(ssh->pinger);
3d9449a1 9831 bufchain_clear(&ssh->queued_incoming_data);
4a693cfc 9832 sfree(ssh->username);
9833 conf_free(ssh->conf);
1e00c92b 9834#ifndef NO_GSSAPI
9835 if (ssh->gsslibs)
9836 ssh_gss_cleanup(ssh->gsslibs);
9837#endif
ee50e8b6 9838 sfree(ssh);
5d17ccfc 9839
9840 random_unref();
fabd1805 9841}
9842
374330e2 9843/*
86916870 9844 * Reconfigure the SSH backend.
86916870 9845 */
4a693cfc 9846static void ssh_reconfig(void *handle, Conf *conf)
86916870 9847{
9848 Ssh ssh = (Ssh) handle;
e13bba36 9849 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 9850 unsigned long old_max_data_size;
4a693cfc 9851 int i, rekey_time;
e6c1536e 9852
4a693cfc 9853 pinger_reconfig(ssh->pinger, ssh->conf, conf);
3b6606c7 9854 if (ssh->portfwds)
4a693cfc 9855 ssh_setup_portfwd(ssh, conf);
e6c1536e 9856
4a693cfc 9857 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9858 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9859 rekey_time != 0) {
d719927e 9860 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
9861 unsigned long now = GETTICKCOUNT();
e6c1536e 9862
d719927e 9863 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
f382c87d 9864 rekeying = "timeout shortened";
e6c1536e 9865 } else {
9866 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9867 }
9868 }
9869
9870 old_max_data_size = ssh->max_data_size;
4a693cfc 9871 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9872 CONF_ssh_rekey_data));
e6c1536e 9873 if (old_max_data_size != ssh->max_data_size &&
9874 ssh->max_data_size != 0) {
9875 if (ssh->outgoing_data_size > ssh->max_data_size ||
9876 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9877 rekeying = "data limit lowered";
e6c1536e 9878 }
9879
4a693cfc 9880 if (conf_get_int(ssh->conf, CONF_compression) !=
9881 conf_get_int(conf, CONF_compression)) {
f382c87d 9882 rekeying = "compression setting changed";
e13bba36 9883 rekey_mandatory = TRUE;
9884 }
9885
4a693cfc 9886 for (i = 0; i < CIPHER_MAX; i++)
9887 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9888 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9889 rekeying = "cipher settings changed";
9890 rekey_mandatory = TRUE;
9891 }
9892 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9893 conf_get_int(conf, CONF_ssh2_des_cbc)) {
f382c87d 9894 rekeying = "cipher settings changed";
e13bba36 9895 rekey_mandatory = TRUE;
e6c1536e 9896 }
9897
4a693cfc 9898 conf_free(ssh->conf);
9899 ssh->conf = conf_copy(conf);
9900 ssh_cache_conf_values(ssh);
e13bba36 9901
9902 if (rekeying) {
9903 if (!ssh->kex_in_progress) {
9904 do_ssh2_transport(ssh, rekeying, -1, NULL);
9905 } else if (rekey_mandatory) {
9906 ssh->deferred_rekey_reason = rekeying;
9907 }
9908 }
86916870 9909}
9910
9911/*
86dc445a 9912 * Called to send data down the SSH connection.
374330e2 9913 */
51470298 9914static int ssh_send(void *handle, char *buf, int len)
32874aea 9915{
51470298 9916 Ssh ssh = (Ssh) handle;
9917
9918 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9919 return 0;
374330e2 9920
d8baa528 9921 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 9922
51470298 9923 return ssh_sendbuffer(ssh);
5471d09a 9924}
9925
9926/*
9927 * Called to query the current amount of buffered stdin data.
9928 */
51470298 9929static int ssh_sendbuffer(void *handle)
5471d09a 9930{
51470298 9931 Ssh ssh = (Ssh) handle;
5471d09a 9932 int override_value;
9933
51470298 9934 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9935 return 0;
9936
9937 /*
9938 * If the SSH socket itself has backed up, add the total backup
9939 * size on that to any individual buffer on the stdin channel.
9940 */
9941 override_value = 0;
51470298 9942 if (ssh->throttled_all)
9943 override_value = ssh->overall_bufsize;
5471d09a 9944
51470298 9945 if (ssh->version == 1) {
5471d09a 9946 return override_value;
51470298 9947 } else if (ssh->version == 2) {
bc06669b 9948 if (!ssh->mainchan)
5471d09a 9949 return override_value;
9950 else
51470298 9951 return (override_value +
9952 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 9953 }
9954
9955 return 0;
374330e2 9956}
9957
9958/*
6e48c3fe 9959 * Called to set the size of the window from SSH's POV.
374330e2 9960 */
51470298 9961static void ssh_size(void *handle, int width, int height)
32874aea 9962{
51470298 9963 Ssh ssh = (Ssh) handle;
ff3187f6 9964 struct Packet *pktout;
51470298 9965
9966 ssh->term_width = width;
9967 ssh->term_height = height;
f278d6f8 9968
51470298 9969 switch (ssh->state) {
374330e2 9970 case SSH_STATE_BEFORE_SIZE:
3687d221 9971 case SSH_STATE_PREPACKET:
21248260 9972 case SSH_STATE_CLOSED:
374330e2 9973 break; /* do nothing */
9974 case SSH_STATE_INTERMED:
51470298 9975 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9976 break;
9977 case SSH_STATE_SESSION:
4a693cfc 9978 if (!conf_get_int(ssh->conf, CONF_nopty)) {
51470298 9979 if (ssh->version == 1) {
9980 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9981 PKT_INT, ssh->term_height,
9982 PKT_INT, ssh->term_width,
32874aea 9983 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9984 } else if (ssh->mainchan) {
134f5ece 9985 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
9986 NULL, NULL);
ff3187f6 9987 ssh2_pkt_adduint32(pktout, ssh->term_width);
9988 ssh2_pkt_adduint32(pktout, ssh->term_height);
9989 ssh2_pkt_adduint32(pktout, 0);
9990 ssh2_pkt_adduint32(pktout, 0);
9991 ssh2_pkt_send(ssh, pktout);
32874aea 9992 }
9993 }
9994 break;
374330e2 9995 }
9996}
9997
9998/*
125105d1 9999 * Return a list of the special codes that make sense in this
10000 * protocol.
10001 */
10002static const struct telnet_special *ssh_get_specials(void *handle)
10003{
786ba75e 10004 static const struct telnet_special ssh1_ignore_special[] = {
10005 {"IGNORE message", TS_NOP}
10006 };
cf6ddb95 10007 static const struct telnet_special ssh2_ignore_special[] = {
62638676 10008 {"IGNORE message", TS_NOP},
cf6ddb95 10009 };
10010 static const struct telnet_special ssh2_rekey_special[] = {
9442dd57 10011 {"Repeat key exchange", TS_REKEY},
62638676 10012 };
10013 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 10014 {NULL, TS_SEP},
10015 {"Break", TS_BRK},
bccbeb71 10016 /* These are the signal names defined by RFC 4254.
6f2d0cde 10017 * They include all the ISO C signals, but are a subset of the POSIX
10018 * required signals. */
10019 {"SIGINT (Interrupt)", TS_SIGINT},
10020 {"SIGTERM (Terminate)", TS_SIGTERM},
10021 {"SIGKILL (Kill)", TS_SIGKILL},
10022 {"SIGQUIT (Quit)", TS_SIGQUIT},
10023 {"SIGHUP (Hangup)", TS_SIGHUP},
10024 {"More signals", TS_SUBMENU},
10025 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10026 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10027 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10028 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10029 {NULL, TS_EXITMENU}
62638676 10030 };
10031 static const struct telnet_special specials_end[] = {
6f2d0cde 10032 {NULL, TS_EXITMENU}
62638676 10033 };
786ba75e 10034 /* XXX review this length for any changes: */
cf6ddb95 10035 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10036 lenof(ssh2_rekey_special) +
62638676 10037 lenof(ssh2_session_specials) +
10038 lenof(specials_end)];
125105d1 10039 Ssh ssh = (Ssh) handle;
62638676 10040 int i = 0;
10041#define ADD_SPECIALS(name) \
10042 do { \
10043 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10044 memcpy(&ssh_specials[i], name, sizeof name); \
10045 i += lenof(name); \
10046 } while(0)
125105d1 10047
10048 if (ssh->version == 1) {
62638676 10049 /* Don't bother offering IGNORE if we've decided the remote
10050 * won't cope with it, since we wouldn't bother sending it if
10051 * asked anyway. */
10052 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 10053 ADD_SPECIALS(ssh1_ignore_special);
125105d1 10054 } else if (ssh->version == 2) {
cf6ddb95 10055 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10056 ADD_SPECIALS(ssh2_ignore_special);
10057 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10058 ADD_SPECIALS(ssh2_rekey_special);
62638676 10059 if (ssh->mainchan)
10060 ADD_SPECIALS(ssh2_session_specials);
10061 } /* else we're not ready yet */
10062
10063 if (i) {
10064 ADD_SPECIALS(specials_end);
10065 return ssh_specials;
10066 } else {
125105d1 10067 return NULL;
62638676 10068 }
10069#undef ADD_SPECIALS
125105d1 10070}
10071
10072/*
86dc445a 10073 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 10074 * can send an EOF and collect resulting output (e.g. `plink
10075 * hostname sort').
374330e2 10076 */
51470298 10077static void ssh_special(void *handle, Telnet_Special code)
32874aea 10078{
51470298 10079 Ssh ssh = (Ssh) handle;
ff3187f6 10080 struct Packet *pktout;
51470298 10081
6abbf9e3 10082 if (code == TS_EOF) {
51470298 10083 if (ssh->state != SSH_STATE_SESSION) {
32874aea 10084 /*
10085 * Buffer the EOF in case we are pre-SESSION, so we can
10086 * send it as soon as we reach SESSION.
10087 */
10088 if (code == TS_EOF)
51470298 10089 ssh->eof_needed = TRUE;
32874aea 10090 return;
10091 }
51470298 10092 if (ssh->version == 1) {
10093 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 10094 } else if (ssh->mainchan) {
bc06669b 10095 sshfwd_write_eof(ssh->mainchan);
00a0b113 10096 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 10097 }
10098 logevent("Sent EOF message");
125105d1 10099 } else if (code == TS_PING || code == TS_NOP) {
51470298 10100 if (ssh->state == SSH_STATE_CLOSED
10101 || ssh->state == SSH_STATE_PREPACKET) return;
10102 if (ssh->version == 1) {
10103 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10104 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 10105 } else {
cf6ddb95 10106 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10107 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10108 ssh2_pkt_addstring_start(pktout);
10109 ssh2_pkt_send_noqueue(ssh, pktout);
10110 }
32874aea 10111 }
9442dd57 10112 } else if (code == TS_REKEY) {
10113 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 10114 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 10115 }
125105d1 10116 } else if (code == TS_BRK) {
10117 if (ssh->state == SSH_STATE_CLOSED
10118 || ssh->state == SSH_STATE_PREPACKET) return;
10119 if (ssh->version == 1) {
2e85c969 10120 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 10121 } else if (ssh->mainchan) {
134f5ece 10122 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
ff3187f6 10123 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10124 ssh2_pkt_send(ssh, pktout);
125105d1 10125 }
6abbf9e3 10126 } else {
6f2d0cde 10127 /* Is is a POSIX signal? */
10128 char *signame = NULL;
10129 if (code == TS_SIGABRT) signame = "ABRT";
10130 if (code == TS_SIGALRM) signame = "ALRM";
10131 if (code == TS_SIGFPE) signame = "FPE";
10132 if (code == TS_SIGHUP) signame = "HUP";
10133 if (code == TS_SIGILL) signame = "ILL";
10134 if (code == TS_SIGINT) signame = "INT";
10135 if (code == TS_SIGKILL) signame = "KILL";
10136 if (code == TS_SIGPIPE) signame = "PIPE";
10137 if (code == TS_SIGQUIT) signame = "QUIT";
10138 if (code == TS_SIGSEGV) signame = "SEGV";
10139 if (code == TS_SIGTERM) signame = "TERM";
10140 if (code == TS_SIGUSR1) signame = "USR1";
10141 if (code == TS_SIGUSR2) signame = "USR2";
10142 /* The SSH-2 protocol does in principle support arbitrary named
10143 * signals, including signame@domain, but we don't support those. */
10144 if (signame) {
10145 /* It's a signal. */
10146 if (ssh->version == 2 && ssh->mainchan) {
134f5ece 10147 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
ff3187f6 10148 ssh2_pkt_addstring(pktout, signame);
10149 ssh2_pkt_send(ssh, pktout);
6f2d0cde 10150 logeventf(ssh, "Sent signal SIG%s", signame);
10151 }
10152 } else {
10153 /* Never heard of it. Do nothing */
10154 }
6abbf9e3 10155 }
374330e2 10156}
10157
51470298 10158void *new_sock_channel(void *handle, Socket s)
d74d141c 10159{
51470298 10160 Ssh ssh = (Ssh) handle;
d74d141c 10161 struct ssh_channel *c;
3d88e64d 10162 c = snew(struct ssh_channel);
d74d141c 10163
70c0cbe1 10164 c->ssh = ssh;
10165 ssh2_channel_init(c);
10166 c->halfopen = TRUE;
10167 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10168 c->u.pfd.s = s;
10169 add234(ssh->channels, c);
d74d141c 10170 return c;
10171}
10172
5471d09a 10173/*
10174 * This is called when stdout/stderr (the entity to which
10175 * from_backend sends data) manages to clear some backlog.
10176 */
ae9ae89f 10177static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 10178{
51470298 10179 Ssh ssh = (Ssh) handle;
ff68564b 10180 int buflimit;
10181
51470298 10182 if (ssh->version == 1) {
10183 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10184 ssh->v1_stdout_throttling = 0;
ff68564b 10185 ssh_throttle_conn(ssh, -1);
5471d09a 10186 }
10187 } else {
ff68564b 10188 if (ssh->mainchan) {
ab87bf1d 10189 ssh2_set_window(ssh->mainchan,
ff68564b 10190 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10191 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
4a693cfc 10192 if (conf_get_int(ssh->conf, CONF_ssh_simple))
ff68564b 10193 buflimit = 0;
10194 else
10195 buflimit = ssh->mainchan->v.v2.locmaxwin;
10196 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10197 ssh->mainchan->throttling_conn = 0;
10198 ssh_throttle_conn(ssh, -1);
10199 }
10200 }
5471d09a 10201 }
78e71de1 10202
10203 /*
10204 * Now process any SSH connection data that was stashed in our
10205 * queue while we were frozen.
10206 */
10207 ssh_process_queued_incoming_data(ssh);
5471d09a 10208}
10209
6b78788a 10210void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 10211{
10212 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 10213 Ssh ssh = c->ssh;
ff3187f6 10214 struct Packet *pktout;
d74d141c 10215
4e63d9b2 10216 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
d74d141c 10217
51470298 10218 if (ssh->version == 1) {
10219 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 10220 PKT_INT, c->localid,
10221 PKT_STR, hostname,
10222 PKT_INT, port,
31fb1866 10223 /* PKT_STR, <org:orgport>, */
bc240b21 10224 PKT_END);
10225 } else {
4a62c66d 10226 pktout = ssh2_chanopen_init(c, "direct-tcpip");
ff3187f6 10227 ssh2_pkt_addstring(pktout, hostname);
10228 ssh2_pkt_adduint32(pktout, port);
bc240b21 10229 /*
10230 * We make up values for the originator data; partly it's
10231 * too much hassle to keep track, and partly I'm not
10232 * convinced the server should be told details like that
10233 * about my local network configuration.
1f182589 10234 * The "originator IP address" is syntactically a numeric
10235 * IP address, and some servers (e.g., Tectia) get upset
10236 * if it doesn't match this syntax.
bc240b21 10237 */
1f182589 10238 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 10239 ssh2_pkt_adduint32(pktout, 0);
10240 ssh2_pkt_send(ssh, pktout);
bc240b21 10241 }
d74d141c 10242}
10243
6226c939 10244static int ssh_connected(void *handle)
32874aea 10245{
51470298 10246 Ssh ssh = (Ssh) handle;
6226c939 10247 return ssh->s != NULL;
32874aea 10248}
8ccc75b0 10249
51470298 10250static int ssh_sendok(void *handle)
32874aea 10251{
51470298 10252 Ssh ssh = (Ssh) handle;
10253 return ssh->send_ok;
32874aea 10254}
fb09bf1c 10255
51470298 10256static int ssh_ldisc(void *handle, int option)
32874aea 10257{
51470298 10258 Ssh ssh = (Ssh) handle;
32874aea 10259 if (option == LD_ECHO)
51470298 10260 return ssh->echoing;
32874aea 10261 if (option == LD_EDIT)
51470298 10262 return ssh->editing;
0965bee0 10263 return FALSE;
10264}
10265
b9d7bcad 10266static void ssh_provide_ldisc(void *handle, void *ldisc)
10267{
10268 Ssh ssh = (Ssh) handle;
10269 ssh->ldisc = ldisc;
10270}
10271
a8327734 10272static void ssh_provide_logctx(void *handle, void *logctx)
10273{
10274 Ssh ssh = (Ssh) handle;
10275 ssh->logctx = logctx;
10276}
10277
51470298 10278static int ssh_return_exitcode(void *handle)
10279{
10280 Ssh ssh = (Ssh) handle;
3bb2f322 10281 if (ssh->s != NULL)
10282 return -1;
10283 else
3c112d53 10284 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 10285}
10286
10287/*
f89c3294 10288 * cfg_info for SSH is the currently running version of the
10289 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10290 */
10291static int ssh_cfg_info(void *handle)
10292{
10293 Ssh ssh = (Ssh) handle;
10294 return ssh->version;
10295}
10296
10297/*
51470298 10298 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10299 * that fails. This variable is the means by which scp.c can reach
10300 * into the SSH code and find out which one it got.
10301 */
10302extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 10303{
51470298 10304 Ssh ssh = (Ssh) handle;
10305 return ssh->fallback_cmd;
d8d6c7e5 10306}
10307
374330e2 10308Backend ssh_backend = {
10309 ssh_init,
fabd1805 10310 ssh_free,
86916870 10311 ssh_reconfig,
374330e2 10312 ssh_send,
5471d09a 10313 ssh_sendbuffer,
374330e2 10314 ssh_size,
4017be6d 10315 ssh_special,
125105d1 10316 ssh_get_specials,
6226c939 10317 ssh_connected,
d8d6c7e5 10318 ssh_return_exitcode,
97db3be4 10319 ssh_sendok,
0965bee0 10320 ssh_ldisc,
b9d7bcad 10321 ssh_provide_ldisc,
a8327734 10322 ssh_provide_logctx,
5471d09a 10323 ssh_unthrottle,
f89c3294 10324 ssh_cfg_info,
9e164d82 10325 "ssh",
10326 PROT_SSH,
97db3be4 10327 22
bc240b21 10328};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator